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Yoo S, Garg E, Elliott LT, Hung RJ, Halevy AR, Brooks JD, Bull SB, Gagnon F, Greenwood C, Lawless JF, Paterson AD, Sun L, Zawati MH, Lerner-Ellis J, Abraham R, Birol I, Bourque G, Garant JM, Gosselin C, Li J, Whitney J, Thiruvahindrapuram B, Herbrick JA, Lorenti M, Reuter MS, Adeoye OO, Liu S, Allen U, Bernier FP, Biggs CM, Cheung AM, Cowan J, Herridge M, Maslove DM, Modi BP, Mooser V, Morris SK, Ostrowski M, Parekh RS, Pfeffer G, Suchowersky O, Taher J, Upton J, Warren RL, Yeung R, Aziz N, Turvey SE, Knoppers BM, Lathrop M, Jones S, Scherer SW, Strug LJ. HostSeq: a Canadian whole genome sequencing and clinical data resource. BMC Genom Data 2023; 24:26. [PMID: 37131148 PMCID: PMC10152008 DOI: 10.1186/s12863-023-01128-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2022] [Accepted: 02/22/2023] [Indexed: 05/04/2023] Open
Abstract
HostSeq was launched in April 2020 as a national initiative to integrate whole genome sequencing data from 10,000 Canadians infected with SARS-CoV-2 with clinical information related to their disease experience. The mandate of HostSeq is to support the Canadian and international research communities in their efforts to understand the risk factors for disease and associated health outcomes and support the development of interventions such as vaccines and therapeutics. HostSeq is a collaboration among 13 independent epidemiological studies of SARS-CoV-2 across five provinces in Canada. Aggregated data collected by HostSeq are made available to the public through two data portals: a phenotype portal showing summaries of major variables and their distributions, and a variant search portal enabling queries in a genomic region. Individual-level data is available to the global research community for health research through a Data Access Agreement and Data Access Compliance Office approval. Here we provide an overview of the collective project design along with summary level information for HostSeq. We highlight several statistical considerations for researchers using the HostSeq platform regarding data aggregation, sampling mechanism, covariate adjustment, and X chromosome analysis. In addition to serving as a rich data source, the diversity of study designs, sample sizes, and research objectives among the participating studies provides unique opportunities for the research community.
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Affiliation(s)
- S Yoo
- The Hospital for Sick Children, Toronto, ON, Canada
- University of Ottawa, Ottawa, ON, Canada
| | - E Garg
- Simon Fraser University, Burnaby, BC, Canada
| | - L T Elliott
- Simon Fraser University, Burnaby, BC, Canada
| | - R J Hung
- University of Toronto, Toronto, ON, Canada
- Lunenfeld-Tanenbaum Research Institute, Sinai Health, Toronto, ON, Canada
| | - A R Halevy
- The Hospital for Sick Children, Toronto, ON, Canada
| | - J D Brooks
- University of Toronto, Toronto, ON, Canada
| | - S B Bull
- University of Toronto, Toronto, ON, Canada
- Lunenfeld-Tanenbaum Research Institute, Sinai Health, Toronto, ON, Canada
| | - F Gagnon
- University of Toronto, Toronto, ON, Canada
| | - Cmt Greenwood
- McGill University, Montreal, QC, Canada
- Lady Davis Institute for Medical Research, Jewish General Hospital, Montreal, QC, Canada
| | - J F Lawless
- University of Waterloo, Waterloo, ON, Canada
| | - A D Paterson
- The Hospital for Sick Children, Toronto, ON, Canada
- University of Toronto, Toronto, ON, Canada
| | - L Sun
- University of Toronto, Toronto, ON, Canada
| | | | - J Lerner-Ellis
- University of Toronto, Toronto, ON, Canada
- Sinai Health System, Toronto, ON, Canada
| | - Rjs Abraham
- Canada's Michael Smith Genome Sciences Centre, Vancouver, BC, Canada
| | - I Birol
- Canada's Michael Smith Genome Sciences Centre, Vancouver, BC, Canada
| | - G Bourque
- McGill University, Montreal, QC, Canada
| | - J-M Garant
- Canada's Michael Smith Genome Sciences Centre, Vancouver, BC, Canada
| | - C Gosselin
- Canada's Michael Smith Genome Sciences Centre, Vancouver, BC, Canada
| | - J Li
- Canada's Michael Smith Genome Sciences Centre, Vancouver, BC, Canada
| | - J Whitney
- The Hospital for Sick Children, Toronto, ON, Canada
| | | | - J-A Herbrick
- The Hospital for Sick Children, Toronto, ON, Canada
| | - M Lorenti
- The Hospital for Sick Children, Toronto, ON, Canada
| | - M S Reuter
- The Hospital for Sick Children, Toronto, ON, Canada
| | - O O Adeoye
- The Hospital for Sick Children, Toronto, ON, Canada
| | - S Liu
- The Hospital for Sick Children, Toronto, ON, Canada
| | - U Allen
- The Hospital for Sick Children, Toronto, ON, Canada
- University of Toronto, Toronto, ON, Canada
| | - F P Bernier
- University of Calgary, Calgary, AB, Canada
- Alberta Children's Hospital, Calgary, AB, Canada
| | - C M Biggs
- University of British Columbia, Vancouver, BC, Canada
- BC Children's Hospital, Vancouver, BC, Canada
- St. Paul's Hospital, Vancouver, BC, Canada
| | - A M Cheung
- University Health Network, Toronto, ON, Canada
| | - J Cowan
- University of Ottawa, Ottawa, ON, Canada
- The Ottawa Hospital Research Institute, Ottawa, ON, Canada
| | - M Herridge
- University Health Network, Toronto, ON, Canada
| | | | - B P Modi
- BC Children's Hospital, Vancouver, BC, Canada
| | - V Mooser
- McGill University, Montreal, QC, Canada
| | - S K Morris
- The Hospital for Sick Children, Toronto, ON, Canada
- University of Toronto, Toronto, ON, Canada
| | - M Ostrowski
- University of Toronto, Toronto, ON, Canada
- St. Michael's Hospital, Unity Health, Toronto, ON, Canada
| | - R S Parekh
- The Hospital for Sick Children, Toronto, ON, Canada
- University of Toronto, Toronto, ON, Canada
- Women's College Hospital, Toronto, ON, Canada
| | - G Pfeffer
- University of Calgary, Calgary, AB, Canada
| | | | - J Taher
- University of Toronto, Toronto, ON, Canada
- Sinai Health System, Toronto, ON, Canada
| | - J Upton
- The Hospital for Sick Children, Toronto, ON, Canada
- University of Toronto, Toronto, ON, Canada
| | - R L Warren
- Canada's Michael Smith Genome Sciences Centre, Vancouver, BC, Canada
| | - Rsm Yeung
- The Hospital for Sick Children, Toronto, ON, Canada
- University of Toronto, Toronto, ON, Canada
| | - N Aziz
- The Hospital for Sick Children, Toronto, ON, Canada
| | - S E Turvey
- University of British Columbia, Vancouver, BC, Canada
- BC Children's Hospital, Vancouver, BC, Canada
| | | | - M Lathrop
- McGill University, Montreal, QC, Canada
| | - Sjm Jones
- Canada's Michael Smith Genome Sciences Centre, Vancouver, BC, Canada
| | - S W Scherer
- The Hospital for Sick Children, Toronto, ON, Canada
- University of Toronto, Toronto, ON, Canada
| | - L J Strug
- The Hospital for Sick Children, Toronto, ON, Canada.
- University of Toronto, Toronto, ON, Canada.
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Bredno J, Lipson J, Venn O, Gross S, Fields AP, Beausang JF, Liu Q, Brooks JD, Chen X, Lopatin R, Liu H, Zhang N, Zhang L, Wu T, Allen B, Hartman AR, Hubbell E, Jamshidi A, Aravanis A. Tumor area and microscopic extent of invasion to determine circulating tumor DNA fraction in plasma and detectability of colorectal cancer (CRC). J Clin Oncol 2020. [DOI: 10.1200/jco.2020.38.4_suppl.243] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
243 Background: Circulating Cell-free Genome Atlas (CCGA; NCT02889978) is a multi-center, case-control, observational study with longitudinal follow-up to develop a cfDNA assay in which classifiers were trained on whole-genome bisulfite sequencing (WGBS) and targeted methylation (TM) sequencing data for detection of multiple cancer types. Previously, we showed that the fraction of ctDNA fragments (TF) was a stronger predictor of cancer detection than clinical stage and an equivalent predictor for survival. Given that CRC tumors can be described via surface area (TSA) and microscopic tumor extent (microinvasion), CRC was used as a model to examine the biophysical determinants of TF. Methods: Detection of multiple cancers with WGBS at 98% and TM at > 99% specificity, and methods for determining TF, were previously reported. A model to predict the presence of detectable cfDNA fragments for CRC adenocarcinomas of stages I, II, and III included TSA and microinvasion beyond the subserosa. Predictors were combined assuming a linear increase of cfDNA shedding with tumor size, with scaling factors depending on microinvasion. Model parameters were determined for 27 participants (7, 11, 9 for stages I, II, III, resp.) with WGBS and applied to 40 participants (12, 15, 13 for I, II, III, resp.) with TM assay and information on tumor size and microinvasion. Results: CRC detection at stages I/II/III was 33/46, 61/73, 57/74% for WGBS/TM. TF predicted detection with AUC = 97.6. The model predicted TF as TSA multiplied by 3.81*10−6 / mm2 for tumors that invaded beyond the subserosa (p < 0.001). This was 4.4x higher than estimates for tumors below the subserosa. The model trained on the WGBS assay predicted CRC detection in the TM assay with an AUC of 0.844. Conclusions: This model used TSA (number of tumor cells) and microinvasion (bloodstream access) to predict the fraction of CRC ctDNA fragments in blood without needing to account for stage. Tumors not penetrating the subserosa had low ctDNA shedding that likely limited detection. These findings may generalize to other cancer types, providing principles to predict ctDNA shedding and thus cancer detectability based on microinvasion and surface area. Clinical trial information: NCT02889978.
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Oxnard GR, Chen X, Fung ET, Ma T, Lipson J, Hubbell E, Kurtzman KN, Patel S, Shaknovich R, Dong Z, Liu H, Brooks JD, Spigel DR, Seiden M, Aravanis A, Klein EA, Hartman AR, Liu MC. Prognostic significance of blood-based cancer detection in plasma cell-free DNA (cfDNA): Evaluating risk of overdiagnosis. J Clin Oncol 2019. [DOI: 10.1200/jco.2019.37.15_suppl.1545] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
1545 Background: Screening tests for early cancer detection are often criticized due to risk of overdiagnosis—detection of good prognosis cancers which may not require immediate treatment. We recently reported development of cfDNA sequencing approaches for cancer detection; longitudinal follow-up (F/U) data were utilized here to evaluate prognostic significance of cancer detection using cfDNA. Methods: Plasma cfDNA samples were subjected to whole-genome bisulfite sequencing (WGBS, 30X) as part of a previously-reported Circulating Cell-free Genome Atlas (CCGA; NCT02889978) substudy. This exploratory analysis evaluated the overall survival (OS) of training and test set participants (pts) with cancer (20 cancer types, any stage I-IV). Combining train and test set pts, univariate and multivariate analyses (Cox proportional hazards) assessed OS association with WGBS result (cancer detected vs not detected, set at 98% specificity), clinical stage (IV vs I-III), diagnostic method (symptom- vs screen-detected), sex, age, and histologic grade. Results: Of 827 pts from the training set with F/U (median 12.2 mo), 334 (40.4%) had WGBS-detected cancer. Among 127 (15.4%) pts with cancer that died during F/U, cancer was detected in 104 (81.9%). Results were similar in the test set. In univariate analyses all variables were associated with prognosis, including WGBS result (HR 7.7 p<0.001). In multivariate analyses accounting for other covariates, the three variables that most significantly remained prognostic were WGBS (HR 3.0, p<0.001), clinical stage (HR 3.3, p<0.001), and diagnostic method (HR 3.0, p<0.001). Validation of these findings is ongoing in an independent cohort of ~5,000 cancer pts from CCGA using an optimized assay; updated performance results will be reported. Conclusions: Cancers detected using WGBS of cfDNA had a worse prognosis than cancers not detected. WGBS cancer detection carried comparable prognostic significance as clinical stage. By preferentially detecting higher risk cancers, cancer detection using plasma cfDNA may avoid some of the overdiagnosis that has been seen with some existing cancer screening methods. Clinical trial information: NCT02889978.
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Affiliation(s)
| | | | | | | | | | | | | | | | | | | | | | | | - David R. Spigel
- Sarah Cannon Research Institute and Tennessee Oncology, Nashville, TN
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Davenport MT, Zhang CA, Leppert JT, Brooks JD, Eisenberg ML. Vasectomy and the risk of prostate cancer in a prospective US Cohort: Data from the NIH-AARP Diet and Health Study. Andrology 2019; 7:178-183. [PMID: 30714352 DOI: 10.1111/andr.12570] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2018] [Revised: 07/13/2018] [Accepted: 11/03/2018] [Indexed: 11/28/2022]
Abstract
BACKGROUND Several studies have linked vasectomy with the risk of prostate cancer; however, this association has been attributed to selection bias. Since vasectomy is a common and effective form of contraception, these implications are significant. Therefore, we sought to test this association in a large observational cohort. OBJECTIVE To evaluate the potential association between prior vasectomy and the risk of developing prostate cancer. MATERIALS AND METHODS We evaluated the relationship between vasectomy and prostate cancer in the NIH-AARP Diet and Health Study. Of the 111,914 men, prostate cancer was identified in 13,885 men and vasectomies were performed in 48,657. We used multivariate analysis to examine the relationship between prostate cancer and vasectomy. We also performed propensity score-adjusted and propensity score-matched analysis. RESULTS Men utilizing vasectomy were more likely to be ever married, fathers, educated, white, and screened for prostate cancer. During 4,251,863 person-years of follow-up, there was a small association between vasectomy and incident prostate cancer with a hazard ratio of 1.05 (95% CI, 1.01-1.11). However, no significant association was found when looking separately at prostate cancer by grade or stage. Conclusions were similar when using propensity adjustment and matching. Importantly, a significant interaction between vasectomy and PSA screening was identified. DISCUSSION Estimates of the association between vasectomy and prostate cancer are sensitive to analytic method underscoring the tenuous nature of the connection. Given the differences between men who do and do not utilize vasectomy, selection bias appears likely to explain any identified association between vasectomy and prostate cancer. CONCLUSIONS With over 20 years of follow-up, no convincing relationship between vasectomy and prostate cancer of any grade was identified.
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Affiliation(s)
- M T Davenport
- Department of Urology, Obstetrics and Gynecology, Stanford University School of Medicine, Stanford, California, USA
| | - C A Zhang
- Department of Urology, Obstetrics and Gynecology, Stanford University School of Medicine, Stanford, California, USA
| | - J T Leppert
- Department of Urology, Obstetrics and Gynecology, Stanford University School of Medicine, Stanford, California, USA
| | - J D Brooks
- Department of Urology, Obstetrics and Gynecology, Stanford University School of Medicine, Stanford, California, USA
| | - M L Eisenberg
- Department of Urology, Obstetrics and Gynecology, Stanford University School of Medicine, Stanford, California, USA
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Yu L, Zhou L, Li Q, Li S, Luo X, Zhang C, Wu B, Brooks JD, Sun H. Elevated urinary lipocalin-2, interleukin-6 and monocyte chemoattractant protein-1 levels in children with congenital ureteropelvic junction obstruction. J Pediatr Urol 2019; 15:44.e1-44.e7. [PMID: 30420258 PMCID: PMC6401238 DOI: 10.1016/j.jpurol.2018.10.007] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/08/2018] [Accepted: 10/05/2018] [Indexed: 11/15/2022]
Abstract
INTRODUCTION In children with congenital ureteropelvic junction obstruction (UPJO), urinary biomarkers could assist in the diagnosis of renal damage or kidneys at risk for damage. Urinary levels of interleukin-6 (IL6), neutrophil gelatinase-associated lipocalin (LCN2), monocyte chemoattractant protein-1 (MCP1), and transforming growth factor-β1 (TGFB1) proteins have been correlated with renal damage in several contexts. Whether they might be useful non-invasive biomarkers of obstructive nephropathy due to unilateral and bilateral congenital UPJO was tested. PATIENTS AND METHODS A cohort study was performed at People's Hospital of Xinjiang Uygur Autonomous Region in China. Bladder urine samples from 17 patients with UPJO were obtained before surgical intervention and from 17 healthy age-matched controls. Levels of IL6, LCN2, MCP1, and TGFB1 were determined by enzyme-linked immunosorbent assay and normalized to urinary creatinine levels. RESULTS Levels of urinary LCN2, MCP1, and IL6 were significantly elevated in the urine from individuals with UPJO compared with controls (P = 0.0003, P = 0.0003, and P = 0.0073, respectively). Children with bilateral UPJO (n = 5) showed significantly higher levels of IL6, LCN2, and MCP1 protein in their urine compared with controls or those with unilateral UPJO (n = 12; P = 0.007, P < 0.0001, and P = 0.0002, respectively). Combining LCN2 and MCP1 slightly improved biomarker performance. DISCUSSION Urinary biomarkers could be used in obstructed patients to monitor for renal damage and might find particular utility on patients with bilateral UPJO. Monitoring urinary biomarkers and imaging features in untreated patients could provide insights into the natural history of renal damage due to obstruction and will be necessary to test their performance characteristics as biomarkers. CONCLUSIONS Urinary levels of LCN2 and MCP1 protein are promising biomarkers monitoring children with UPJO, particularly in those with bilateral disease.
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Affiliation(s)
- L Yu
- Xinjiang Institute of Pediatrics, People's Hospital of Xinjiang Uygur Autonomous Region, Urumqi, China
| | - L Zhou
- Department of Pediatric Surgery, People's Hospital of Xinjiang Uygur Autonomous Region, Urumqi, China
| | - Q Li
- Xinjiang Institute of Pediatrics, People's Hospital of Xinjiang Uygur Autonomous Region, Urumqi, China
| | - S Li
- Department of Pediatric Surgery, People's Hospital of Xinjiang Uygur Autonomous Region, Urumqi, China
| | - X Luo
- Xinjiang Institute of Pediatrics, People's Hospital of Xinjiang Uygur Autonomous Region, Urumqi, China
| | - C Zhang
- Department of Urology, Stanford University School of Medicine, Stanford, CA, USA
| | - B Wu
- Department of Urology, Stanford University School of Medicine, Stanford, CA, USA
| | - J D Brooks
- Department of Urology, Stanford University School of Medicine, Stanford, CA, USA.
| | - H Sun
- Xinjiang Institute of Pediatrics, People's Hospital of Xinjiang Uygur Autonomous Region, Urumqi, China.
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Eminaga O, Li S, Baker LC, Brooks JD, Eisenberg ML. Male infertility is associated with altered treatment course of men with cancer. Andrology 2018; 6:408-413. [PMID: 29457365 DOI: 10.1111/andr.12472] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2017] [Revised: 12/11/2017] [Accepted: 01/15/2018] [Indexed: 10/18/2022]
Abstract
This study aims to evaluate whether cancer treatments differ in infertile men compared to men who have undergone vasectomy and age-matched controls. We analyzed subjects from the Truven Health MarketScan Claims database from 2001 to 2009. Infertile men were identified through diagnosis and treatment codes. Comparison groups included vasectomized men and an age-matched cohort who were not infertile and had not undergone vasectomy. We considered cancer types previously associated with infertility that were diagnosed after the diagnosis of infertility. The treatment regimens were determined based on the presence of claims with CPT codes for chemotherapy (CTX), radiation (RTX) or surgical treatment (ST) for each entity in all study groups. Cases with multimodal treatments were also identified. As a result, CTX was similarly distributed among the infertile, vasectomized, and control groups. In contrast, RTX treatment length was shorter in infertile men. The frequency of multimodal treatment (i.e., radiation and chemotherapy) was twofold lower in men with infertility compared to other men. By focusing on treatment patterns for each cancer type among these groups, the duration of RTX and CTX was shorter in infertile men diagnosed with NHL compared to controls. We conclude that Infertile men diagnosed with cancer and specific cancer types experience different treatment courses, with shorter RTX and less combined RTX/CTX compared to fertile and vasectomized men. These differences could reflect differences in stage at presentation, biological behavior, or treatment responses in infertile men.
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Affiliation(s)
- O Eminaga
- Department of Urology, Stanford University School of Medicine, Stanford, CA, USA.,Department of Urology, University Hospital of Cologne, Cologne, Germany
| | - S Li
- Departments of Urology and Dermatology, Stanford University School of Medicine, Stanford, CA, USA
| | - L C Baker
- Department of Health Research and Policy, Stanford University School of Medicine, Stanford, CA, USA
| | - J D Brooks
- Department of Urology, Stanford University School of Medicine, Stanford, CA, USA
| | - M L Eisenberg
- Department of Urology, Stanford University School of Medicine, Stanford, CA, USA
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Liss MA, Schenk JM, Faino AV, Newcomb LF, Boyer H, Brooks JD, Carroll PR, Dash A, Fabrizio MD, Gleave ME, Nelson PS, Neuhouser ML, Wei JT, Zheng Y, Wright JL, Lin DW, Thompson IM. A diagnosis of prostate cancer and pursuit of active surveillance is not followed by weight loss: potential for a teachable moment. Prostate Cancer Prostatic Dis 2016; 19:390-394. [PMID: 27431498 DOI: 10.1038/pcan.2016.28] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2016] [Revised: 05/12/2016] [Accepted: 06/07/2016] [Indexed: 01/28/2023]
Abstract
BACKGROUND Obesity is a risk factor for incident prostate cancer (PC) as well as risk of disease progression and mortality. We hypothesized that men diagnosed with lower-risk PC and who elected active surveillance (AS) for their cancer management would likely initiate lifestyle changes that lead to weight loss. METHODS Patients were enrolled in the Prostate Active Surveillance Study (PASS), a multicenter prospective biomarker discovery and validation study of men who have chosen AS for their PC. Data from 442 men diagnosed with PC within 1 year of study entry who completed a standard of care 12-month follow-up visit were analyzed. We examined the change in weight and body mass index (BMI) over the first year of study participation. RESULTS After 1 year on AS, 7.5% (33/442) of patients had lost 5% or more of their on-study weight. The proportion of men who lost 5% or more weight was similar across categories of baseline BMI: normal/underweight (8%), overweight (6%) and obese (10%, χ2 test P=0.44). The results were similar for patients enrolled in the study 1 year or 6 months after diagnosis. By contrast, after 1 year, 7.7% (34/442) of patients had gained >5% of their weight. CONCLUSIONS Only 7.5% of men with low-risk PC enrolled in AS lost a modest (⩾5%) amount of weight after diagnosis. Given that obesity is related to PC progression and mortality, targeted lifestyle interventions may be effective at this 'teachable moment', as men begin AS for low-risk PC.
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Affiliation(s)
- M A Liss
- Department of Urology, University of Texas Health Science Center San Antonio, San Antonio, TX, USA
| | - J M Schenk
- Fred Hutchinson Cancer Research Center, Seattle, WA, USA
| | - A V Faino
- Fred Hutchinson Cancer Research Center, Seattle, WA, USA
| | - L F Newcomb
- Fred Hutchinson Cancer Research Center, University of Washington, Seattle, WA, USA
| | - H Boyer
- Fred Hutchinson Cancer Research Center, University of Washington, Seattle, WA, USA
| | | | - P R Carroll
- University of California at San Francisco, San Francisco, CA, USA
| | - A Dash
- University of Washington, Seattle, WA, USA
| | - M D Fabrizio
- Eastern Virginia Medical School, Norfolk, VA, USA
| | - M E Gleave
- University of British Columbia, Vancouver, BC, Canada
| | - P S Nelson
- Fred Hutchinson Cancer Research Center, University of Washington, Seattle, WA, USA
| | - M L Neuhouser
- Fred Hutchinson Cancer Research Center, Seattle, WA, USA
| | - J T Wei
- University of Michigan, Ann Arbor, MI, USA
| | - Y Zheng
- Fred Hutchinson Cancer Research Center, Seattle, WA, USA
| | - J L Wright
- Fred Hutchinson Cancer Research Center, University of Washington, Seattle, WA, USA
| | - D W Lin
- Fred Hutchinson Cancer Research Center, University of Washington, Seattle, WA, USA
| | - I M Thompson
- Department of Urology, University of Texas Health Science Center San Antonio, San Antonio, TX, USA
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Tretiakova MS, Wei W, Boyer HD, Newcomb LF, Hawley S, Auman H, Vakar-Lopez F, McKenney JK, Fazli L, Simko J, Troyer DA, Hurtado-Coll A, Thompson IM, Carroll PR, Ellis WJ, Gleave ME, Nelson PS, Lin DW, True LD, Feng Z, Brooks JD. Prognostic value of Ki67 in localized prostate carcinoma: a multi-institutional study of >1000 prostatectomies. Prostate Cancer Prostatic Dis 2016; 19:264-70. [PMID: 27136741 DOI: 10.1038/pcan.2016.12] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2015] [Revised: 02/17/2016] [Accepted: 03/08/2016] [Indexed: 01/07/2023]
Abstract
BACKGROUND Expanding interest in and use of active surveillance for early state prostate cancer (PC) has increased need for prognostic biomarkers. Using a multi-institutional tissue microarray resource including over 1000 radical prostatectomy samples, we sought to correlate Ki67 expression captured by an automated image analysis system with clinicopathological features and validate its utility as a clinical grade test in predicting cancer-specific outcomes. METHODS After immunostaining, the Ki67 proliferation index (PI) of tumor areas of each core (three cancer cores/case) was analyzed using a nuclear quantification algorithm (Aperio). We assessed whether Ki67 PI was associated with clinicopathological factors and recurrence-free survival (RFS) including biochemical recurrence, metastasis or PC death (7-year median follow-up). RESULTS In 1004 PCs (∼4000 tissue cores) Ki67 PI showed significantly higher inter-tumor (0.68) than intra-tumor variation (0.39). Ki67 PI was associated with stage (P<0.0001), seminal vesicle invasion (SVI, P=0.02), extracapsular extension (ECE, P<0.0001) and Gleason score (GS, P<0.0001). Ki67 PI as a continuous variable significantly correlated with recurrence-free, overall and disease-specific survival by multivariable Cox proportional hazard model (hazards ratio (HR)=1.04-1.1, P=0.02-0.0008). High Ki67 score (defined as ⩾5%) was significantly associated with worse RFS (HR=1.47, P=0.0007) and worse overall survival (HR=2.03, P=0.03). CONCLUSIONS In localized PC treated by radical prostatectomy, higher Ki67 PI assessed using a clinical grade automated algorithm is strongly associated with a higher GS, stage, SVI and ECE and greater probability of recurrence.
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Affiliation(s)
| | - W Wei
- MD Anderson Cancer Center, Houston, TX, USA
| | - H D Boyer
- Fred Hutchinson Cancer Research Center, Seattle, WA, USA
| | - L F Newcomb
- University of Washington, Seattle, WA, USA.,Fred Hutchinson Cancer Research Center, Seattle, WA, USA
| | - S Hawley
- Canary Foundation, Redwood City, CA, USA
| | - H Auman
- Canary Foundation, Redwood City, CA, USA
| | | | | | - L Fazli
- University of British Columbia, Vancouver, BC, Canada
| | - J Simko
- University of California at San Francisco, CA, USA
| | - D A Troyer
- Eastern Virginia Medical School, Norfolk, VA, USA
| | | | - I M Thompson
- University of Texas Health Sciences Center at San Antonio, TX, USA
| | - P R Carroll
- University of California at San Francisco, CA, USA
| | - W J Ellis
- University of Washington, Seattle, WA, USA.,Fred Hutchinson Cancer Research Center, Seattle, WA, USA
| | - M E Gleave
- University of British Columbia, Vancouver, BC, Canada
| | - P S Nelson
- University of Washington, Seattle, WA, USA.,Fred Hutchinson Cancer Research Center, Seattle, WA, USA
| | - D W Lin
- University of Washington, Seattle, WA, USA.,Fred Hutchinson Cancer Research Center, Seattle, WA, USA
| | - L D True
- University of Washington, Seattle, WA, USA
| | - Z Feng
- MD Anderson Cancer Center, Houston, TX, USA
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Guth K, Riviere JE, Brooks JD, Dammann M, Fabian E, van Ravenzwaay B, Schäfer-Korting M, Landsiedel R. In silico models to predict dermal absorption from complex agrochemical formulations. SAR QSAR Environ Res 2014; 25:565-588. [PMID: 24905588 DOI: 10.1080/1062936x.2014.919358] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Dermal absorption is a critical part in the risk assessment of complex mixtures such as agrochemical formulations. To reduce the number of in vivo or in vitro absorption experiments, the present study aimed to develop an in silico prediction model that considers mixture-related effects. Therefore, an experimental 'real-world' dataset derived from regulatory in vitro studies with human and rat skin was processed. Overall, 56 test substances applied in more than 150 mixtures were used. Descriptors for the substances as well as the mixtures were generated and used for multiple linear regression analysis. Considering the heterogeneity of the underlying data set, the final model provides a good fit (r² = 0.75) and is able to estimate the influence of a newly composed formulation on dermal absorption of a well-known substance (predictivity Q²Ext = 0.73). Application of this model would reduce animal and non-animal testings when used for the optimization of formulations in early developmental stages, or would simplify the registration process, if accepted for read-across.
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Affiliation(s)
- K Guth
- a Experimental Toxicology and Ecology , BASF SE , Ludwigshafen , Germany
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10
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Howard JT, Baynes RE, Brooks JD, Yeatts JL, Bellis B, Ashwell MS, Routh P, O'Nan AT, Maltecca C. The effect of breed and sex on sulfamethazine, enrofloxacin, fenbendazole and flunixin meglumine pharmacokinetic parameters in swine. J Vet Pharmacol Ther 2014; 37:531-41. [PMID: 24731191 DOI: 10.1111/jvp.12128] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2013] [Accepted: 02/28/2014] [Indexed: 12/01/2022]
Abstract
Drug use in livestock has received increased attention due to welfare concerns and food safety. Characterizing heterogeneity in the way swine populations respond to drugs could allow for group-specific dose or drug recommendations. Our objective was to determine whether drug clearance differs across genetic backgrounds and sex for sulfamethazine, enrofloxacin, fenbendazole and flunixin meglumine. Two sires from each of four breeds were mated to a common sow population. The nursery pigs generated (n = 114) were utilized in a random crossover design. Drugs were administered intravenously and blood collected a minimum of 10 times over 48 h. A non-compartmental analysis of drug and metabolite plasma concentration vs. time profiles was performed. Within-drug and metabolite analysis of pharmacokinetic parameters included fixed effects of drug administration date, sex and breed of sire. Breed differences existed for flunixin meglumine (P-value<0.05; Cl, Vdss ) and oxfendazole (P-value<0.05, AUC0→∞ ). Sex differences existed for oxfendazole (P-value < 0.05; Tmax ) and sulfamethazine (P-value < 0.05, Cl). Differences in drug clearance were seen, and future work will determine the degree of additive genetic variation utilizing a larger population.
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Affiliation(s)
- J T Howard
- Department of Animal Science, North Carolina State University, Raleigh, NC, USA
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11
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Riviere JE, Brooks JD, Collard WT, Deng J, de Rose G, Mahabir SP, Merritt DA, Marchiondo AA. Prediction of formulation effects on dermal absorption of topically applied ectoparasiticides dosed in vitro on canine and porcine skin using a mixture-adjusted quantitative structure permeability relationship. J Vet Pharmacol Ther 2014; 37:435-44. [PMID: 24649911 DOI: 10.1111/jvp.12121] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2013] [Accepted: 01/26/2014] [Indexed: 11/29/2022]
Abstract
Topical application of ectoparasiticides for flea and tick control is a major focus for product development in animal health. The objective of this work was to develop a quantitative structure permeability relationship (QSPeR) model sensitive to formulation effects for predicting absorption and skin deposition of five topically applied drugs administered in six vehicle combinations to porcine and canine skin in vitro. Saturated solutions (20 μL) of (14) C-labeled demiditraz, fipronil, permethrin, imidacloprid, or sisapronil were administered in single or binary (50:50 v/v) combinations of water, ethanol, and transcutol (6 formulations, n = 4-5 replicates per treatment) nonoccluded to 0.64 cm(2) disks of dermatomed pig or dog skin mounted in flow-through diffusion cells. Perfusate flux over 24 h and skin deposition at termination were determined. Permeability (logKp), absorption, and penetration endpoints were modeled using a four-term Abrahams and Martin (hydrogen-bond donor acidity and basicity, dipolarity/polarizability, and excess molar refractivity) linear free energy QSPeR equation with a mixture factor added to compensate for formulation ingredient interactions. Goodness of fit was judged by r(2) , cross-validation coefficient, coefficients (q(2) s), and Williams Plot to visualize the applicability domain. Formulation composition was the primary determinant of permeation. Compounds generally penetrated dog skin better than porcine skin. The vast majority of permeated penetrant was deposited within the dosed skin relative to transdermal flux, an attribute for ectoparasiticides. The best QSPeR logKp model for pig skin permeation (r(2) = 0.86, q(2) s = 0.85) included log octanol/water partition coefficient as the mixture factor, while for dogs (r(2) = 0.91, q(2) s = 0.90), it was log water solubility. These studies clearly showed that the permeation of topical ectoparasiticides could be well predicted using QSPeR models that account for both the physical-chemical properties of the penetrant and formulation components.
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Affiliation(s)
- J E Riviere
- Institute of Computational Comparative Medicine, College of Veterinary Medicine, Kansas State University, Manhattan, KS, USA; Center for Chemical Toxicology Research and Pharmacokinetics, College of Veterinary Medicine, North Carolina State University, Raleigh, NC, USA
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12
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Xu G, Hughes-Oliver JM, Brooks JD, Baynes RE. Predicting skin permeability from complex chemical mixtures: incorporation of an expanded QSAR model. SAR QSAR Environ Res 2013; 24:711-731. [PMID: 23767783 DOI: 10.1080/1062936x.2013.792875] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Quantitative structure-activity relationship (QSAR) models have been widely used to study the permeability of chemicals or solutes through skin. Among the various QSAR models, Abraham's linear free-energy relationship (LFER) model is often employed. However, when the experimental conditions are complex, it is not always appropriate to use Abraham's LFER model with a single set of regression coefficients. In this paper, we propose an expanded model in which one set of partial slopes is defined for each experimental condition, where conditions are defined according to solvent: water, synthetic oil, semi-synthetic oil, or soluble oil. This model not only accounts for experimental conditions but also improves the ability to conduct rigorous hypothesis testing. To more adequately evaluate the predictive power of the QSAR model, we modified the usual leave-one-out internal validation strategy to employ a leave-one-solute-out strategy and accordingly adjust the Q(2) LOO statistic. Skin permeability was shown to have the rank order: water > synthetic > semi-synthetic > soluble oil. In addition, fitted relationships between permeability and solute characteristics differ according to solvents. We demonstrated that the expanded model (r(2) = 0.70) improved both the model fit and the predictive power when compared with the simple model (r(2) = 0.21).
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Affiliation(s)
- G Xu
- Department of Statistics, North Carolina State University, Raleigh, USA
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13
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Xu G, Hughes-Oliver JM, Brooks JD, Yeatts JL, Baynes RE. Selection of appropriate training and validation set chemicals for modelling dermal permeability by U-optimal design. SAR QSAR Environ Res 2012; 24:135-156. [PMID: 23157374 DOI: 10.1080/1062936x.2012.742458] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Quantitative structure-activity relationship (QSAR) models are being used increasingly in skin permeation studies. The main idea of QSAR modelling is to quantify the relationship between biological activities and chemical properties, and thus to predict the activity of chemical solutes. As a key step, the selection of a representative and structurally diverse training set is critical to the prediction power of a QSAR model. Early QSAR models selected training sets in a subjective way and solutes in the training set were relatively homogenous. More recently, statistical methods such as D-optimal design or space-filling design have been applied but such methods are not always ideal. This paper describes a comprehensive procedure to select training sets from a large candidate set of 4534 solutes. A newly proposed 'Baynes' rule', which is a modification of Lipinski's 'rule of five', was used to screen out solutes that were not qualified for the study. U-optimality was used as the selection criterion. A principal component analysis showed that the selected training set was representative of the chemical space. Gas chromatograph amenability was verified. A model built using the training set was shown to have greater predictive power than a model built using a previous dataset [1].
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Affiliation(s)
- G Xu
- Department of Statistics, North Carolina State University, Raleigh, NC, USA
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14
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Abstract
Increasing evidence suggests that prostate cancer is overdiagnosed and overtreated, and prognostic biomarkers would aid in treatment selection. To define prognostic biomarkers for aggressive prostate cancer, we carried out gene-expression profiling of 98 prostate tumors and 52 benign adjacent prostate tissue samples with detailed clinical annotation. We identified 28 transcripts significantly associated with recurrence after radical prostatectomy including NuSAP, a protein that binds DNA to the mitotic spindle. Elevated NuSAP transcript levels were associated with poor outcome in two independent prostate cancer gene-expression datasets. To characterize the role and regulation of NuSAP in prostate cancer, we studied the expression of NuSAP in the LNCaP and PC3 human prostate cancer cell lines. Posttranscriptional silencing of the NuSAP gene severely hampered the ability of PC3 to invade and proliferate in vitro. The promoter region of the NuSAP gene contains two CCAAT boxes and binding sites for E2F. Transient transfection of an E2F1 cDNA and 431 bp of the NuSAP promoter demonstrated E2F1 as an important regulator of expression. Deletion of the E2F-binding site at nucleotide -246 negated the effects of E2F1 on NuSAP expression. Electrophoretic mobility shift assays demonstrated that nuclear extracts of cells overexpressing E2F1 bound directly to the E2F-binding site in the NuSAP promoter region. Finally, immunohistochemistry showed a strong correlation between E2F1 and NuSAP expression in human prostate cancer samples. NuSAP is a novel biomarker for prostate cancer recurrence after surgery and its overexpression appears to be driven in part by E2F1 activation.
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Affiliation(s)
- Z G Gulzar
- Department of Urology, Stanford University School of Medicine, Stanford, CA 94305-5118, USA
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15
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Huang S, Gulzar ZG, Salari K, Lapointe J, Brooks JD, Pollack JR. Recurrent deletion of CHD1 in prostate cancer with relevance to cell invasiveness. Oncogene 2011; 31:4164-70. [PMID: 22179824 DOI: 10.1038/onc.2011.590] [Citation(s) in RCA: 89] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Though prostate cancer is often indolent, it is nonetheless a leading cause of cancer death. Defining the underlying molecular genetic alterations may lead to new strategies for prevention or treatment. Towards this goal, we performed array-based comparative genomic hybridization (CGH) on 86 primary prostate tumors. Among the most frequent alterations not associated with a known cancer gene, we identified focal deletions within 5q21 in 15 out of 86 (17%) cases. By high-resolution tiling array CGH, the smallest common deletion targeted just one gene, the chromatin remodeler chromodomain helicase DNA-binding protein 1 (CHD1). Expression of CHD1 was significantly reduced in tumors with deletion (P=0.03), and compared with normal prostate (P=0.04). Exon sequencing analysis also uncovered nonsynonymous mutations in 1 out of 7 (14%) cell lines (LAPC4) and in 1 out of 24 (4%) prostate tumors surveyed. RNA interference-mediated knockdown of CHD1 in two nontumorigenic prostate epithelial cell lines, OPCN2 and RWPE-1, did not alter cell growth, but promoted cell invasiveness, and in OPCN2-enhanced cell clonogenicity. Taken together, our findings suggest that CHD1 deletion may underlie cell invasiveness in a subset of prostate cancers, and indicate a possible novel role of altered chromatin remodeling in prostate tumorigenesis.
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Affiliation(s)
- S Huang
- Department of Pathology, Stanford University School of Medicine, Stanford, CA 94305-5176, USA
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16
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Ghafourian T, Samaras EG, Brooks JD, Riviere JE. Modelling the effect of mixture components on permeation through skin. Int J Pharm 2010; 398:28-32. [PMID: 20643197 DOI: 10.1016/j.ijpharm.2010.07.014] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2010] [Revised: 07/08/2010] [Accepted: 07/09/2010] [Indexed: 10/19/2022]
Abstract
A vehicle influences the concentration of penetrant within the membrane, affecting its diffusivity in the skin and rate of transport. Despite the huge amount of effort made for the understanding and modelling of the skin absorption of chemicals, a reliable estimation of the skin penetration potential from formulations remains a challenging objective. In this investigation, quantitative structure-activity relationship (QSAR) was employed to relate the skin permeation of compounds to the chemical properties of the mixture ingredients and the molecular structures of the penetrants. The skin permeability dataset consisted of permeability coefficients of 12 different penetrants each blended in 24 different solvent mixtures measured from finite-dose diffusion cell studies using porcine skin. Stepwise regression analysis resulted in a QSAR employing two penetrant descriptors and one solvent property. The penetrant descriptors were octanol/water partition coefficient, logP and the ninth order path molecular connectivity index, and the solvent property was the difference between boiling and melting points. The negative relationship between skin permeability coefficient and logP was attributed to the fact that most of the drugs in this particular dataset are extremely lipophilic in comparison with the compounds in the common skin permeability datasets used in QSAR. The findings show that compounds formulated in vehicles with small boiling and melting point gaps will be expected to have higher permeation through skin. The QSAR was validated internally, using a leave-many-out procedure, giving a mean absolute error of 0.396. The chemical space of the dataset was compared with that of the known skin permeability datasets and gaps were identified for future skin permeability measurements.
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Affiliation(s)
- T Ghafourian
- Medway School of Pharmacy, Universities of Kent and Greenwich, Chatham, Kent ME4 4TB, UK.
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17
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Abstract
AIMS To examine the rate and the extent of spore formation in Anoxybacillus flavithermus biofilms and to test the effect of one key variable - temperature - on spore formation. METHODS AND RESULTS A continuous flow laboratory reactor was used to grow biofilms of the typical dairy thermophile A. flavithermus (strain CM) in skim milk. The reactor was inoculated with either a washed culture or a spore suspension of A. flavithermus CM, and was run over an 8.5 h period at three different temperatures of 48, 55 and 60 degrees C. Change in impedance was used to determine the cell numbers in the milk and on the surface of the stainless steel reactor tubes. The biofilm developed at all three temperatures within 6-8 h. Spores formed at 55 and 60 degrees C and amounted to approx. 10-50% of the biofilm. No spores formed at 48 degrees C. CONCLUSIONS The results suggest that both biofilm formation and spore formation of A. flavithermus can occur very rapidly and simultaneously. In addition, temperature variation has a considerable effect on the formation of spores. SIGNIFICANCE AND IMPACT OF THE STUDY This information will provide direction for developing improved ways in which to manipulate conditions in milk powder manufacturing plants to control biofilms and spores of A. flavithermus.
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Affiliation(s)
- S A Burgess
- Institute of Molecular Biosciences, Massey University, Palmerston North, New Zealand.
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18
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Riviere JE, Brooks JD. Prediction of dermal absorption from complex chemical mixtures: incorporation of vehicle effects and interactions into a QSPR framework. SAR QSAR Environ Res 2007; 18:31-44. [PMID: 17365957 DOI: 10.1080/10629360601033598] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
Abstract
Significant progress has been made on predicting dermal absorption/penetration of topically applied compounds by developing QSPR models based on linear free energy relations (LFER). However, all of these efforts have employed compounds applied to the skin in aqueous or single solvent systems, a dosing scenario that does not mimic occupational, environmental or pharmaceutical exposure. We have explored using hybrid QSPR equations describing individual compound penetration based on the molecular descriptors for the compound modified by a mixture factor (MF) which accounts for the physicochemical properties of the vehicle/mixture components. The MF is calculated based on percentage composition of the vehicle/mixture components and physical chemical properties selected using principal components analysis. This model has been applied to 12 different compounds in 24 mixtures for a total of 288 treatment combinations obtained from flow-through porcine skin diffusion cells and in an additional dataset of 10 of the same compounds in five mixtures for a total of 50 treatment combinations in the ex vivo isolated perfused porcine skin flap. The use of the MF in combination with a classic LFER based on penetrant properties significantly improved the ability to predict dermal absorption of compounds dosed in complex chemical mixtures.
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Affiliation(s)
- J E Riviere
- Center for Chemical Toxicology Research and Pharmacokinetics, North Carolina State University, 4700 Hillsborough Street, Raleigh, NC 27606, USA.
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19
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Karicheti V, Stone EA, Langdale CL, Katofiasc MA, Brooks JD, Olejar KJ, Young MC, Thor KB. 1371: Chronic Real-Time Ambulatory Urodynamics in Cats Using Radio Telemetry for Drug Screening. J Urol 2006. [DOI: 10.1016/s0022-5347(18)33584-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
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20
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van der Merwe D, Brooks JD, Gehring R, Baynes RE, Monteiro-Riviere NA, Riviere JE. A Physiologically Based Pharmacokinetic Model of Organophosphate Dermal Absorption. Toxicol Sci 2005; 89:188-204. [PMID: 16221965 DOI: 10.1093/toxsci/kfj014] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The rate and extent of dermal absorption are important in the analysis of risk from dermal exposure to toxic chemicals and for the development of topically applied drugs, barriers, insect repellents, and cosmetics. In vitro flow-through cells offer a convenient method for the study of dermal absorption that is relevant to the initial processes of dermal absorption. This study describes a physiologically based pharmacokinetic (PBPK) model developed to simulate the absorption of organophosphate pesticides, such as parathion, fenthion, and methyl parathion through porcine skin with flow-through cells. Parameters related to the structure of the stratum corneum and solvent evaporation rates were independently estimated. Three parameters were optimized based on experimental dermal absorption data, including solvent evaporation rate, diffusivity, and a mass transfer factor. Diffusion cell studies were conducted to validate the model under a variety of conditions, including different dose ranges (6.3-106.9 microg/cm2 for parathion; 0.8-23.6 microg/cm2 for fenthion; 1.6-39.3 microg/cm2 for methyl parathion), different solvents (ethanol, 2-propanol and acetone), different solvent volumes (5-120 microl for ethanol; 20-80 microl for 2-propanol and acetone), occlusion versus open to atmosphere dosing, and corneocyte removal by tape-stripping. The study demonstrated the utility of PBPK models for studying dermal absorption, which can be useful as explanatory and predictive tools that may be used for in silico hypotheses generation and limited hypotheses testing. The similarity between the overall shapes of the experimental and model-predicted flux/time curves and the successful simulation of altered system conditions for this series of small, lipophilic compounds indicated that the absorption processes that were described in the model successfully simulated important aspects of dermal absorption in flow-through cells. These data have direct relevance to topical organophosphate pesticide risk assessments.
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Affiliation(s)
- D van der Merwe
- Center for Chemical Toxicology Research and Pharmacokinetics, College of Veterinary Medicine, NC State University, Raleigh, North Carolina 27606, USA
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21
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Abstract
AIMS To determine the mechanism for both the removal and inactivation of 18-h biofilms of a thermophilic Bacillus species that optimally grows at 55 degrees C on stainless steel. METHODS AND RESULTS The cleaning strategies tested were based on biofilm biochemistry and physiology, and focused on the chemistry of the cleaners, the duration and temperature of the cleaning process and a combination of various cleaners. The success of the cleaning regimes was determined based on the removal of cells and organic debris and the elimination of viable cells. The results confirmed that a caustic (75 degrees C for 30 min) and acid (75 degrees C for 30 min) wash, relied upon heavily in most food processing industries for cleaning-in-place systems, was successful in removing these biofilms. However, any changes in the concentrations of these cleaners or the temperature of cleaning drastically affected the overall outcome. Alternative cleaning agents based on enzymatic or nonenzymatic breakdown of cellular proteins or polysaccharides, surfactant action, use of oxidative attack and free radicals varied in degrees of their success. Combining proteolytic action with surfactants increased wetability and therefore enhanced the cleaning efficiency. CONCLUSIONS Several procedures, including caustic/acid and enzyme based cleaners, will be satisfactory, provided that the correct process parameters are observed i.e. concentration, time, temperature and kinetic energy (flow). Confirmation of these results should be carried out in a pilot plant through several use/clean cycles. SIGNIFICANCE AND IMPACT OF THE STUDY Confidence in standard and alternative cleaning procedures for food manufacturing plant to prevent contamination with thermophilic bacilli that threaten product quality.
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Affiliation(s)
- S G Parkar
- Institute of Food, Nutrition and Human Health, Massey University, Palmerston North, New Zealand.
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22
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Bebermeier JH, DePrimo SE, Brooks JD, Hiort O, Holterhus PM. Microarray-analysis of global androgen receptor co-regulator expression patterns in cultures derived from human urogenital tissues. Exp Clin Endocrinol Diabetes 2004. [DOI: 10.1055/s-2004-819051] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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23
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Parkar SG, Flint SH, Brooks JD. Physiology of biofilms of thermophilic bacilli-potential consequences for cleaning. J Ind Microbiol Biotechnol 2003; 30:553-60. [PMID: 14513382 DOI: 10.1007/s10295-003-0081-x] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2002] [Accepted: 07/07/2003] [Indexed: 10/26/2022]
Abstract
Thermophilic Bacillus species readily attached and grew on stainless steel surfaces, forming mature biofilms of >10(6.0) cells/cm2 in 6 h on a surface inoculated with the bacteria. Clean stainless steel exposed only to pasteurized skim milk at 55 degrees C developed a mature biofilm of >10(6.0) cells/cm2 within 18 h. When bacilli were inoculated onto the steel coupons, 18-h biofilms were 30 microm thick. Biofilm growth followed a repeatable pattern, with a reduction in the numbers of bacteria on the surface occurring after 30 h, followed by a recovery. This reduction in numbers was associated with the production of a substance that inhibited the growth of the bacteria. Variations in the environment, including pH and molarity, affected the viability of the cells. Chemicals that attack the polysaccharide matrix of the biofilm were particularly effective in killing and removing cells from the biofilm, demonstrating the importance of polysaccharides in the persistence of these biofilms. Treatment of either the biofilm or a clean stainless steel surface with lysozyme killed biofilm cells and prevented the attachment of any bacteria exposed to the surface. This suggests that lysozyme may have potential as an alternative control method for biofilms of these bacteria.
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Affiliation(s)
- S G Parkar
- Institute of Food, Nutrition and Human Health, Massey University, Private Bag 11222, Palmerston North, New Zealand
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24
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Brooks JD, Metter EJ, Chan DW, Sokoll LJ, Landis P, Nelson WG, Muller D, Andres R, Carter HB. Plasma selenium level before diagnosis and the risk of prostate cancer development. J Urol 2001. [PMID: 11696701 DOI: 10.1016/s0022-5347(05)65500-0] [Citation(s) in RCA: 84] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
PURPOSE Epidemiological studies and a randomized intervention trial suggest that the risk of prostate cancer may be reduced by selenium intake. We investigated whether plasma selenium level before diagnosis correlated with the risk of later developing prostate cancer. MATERIALS AND METHODS A case control study was performed on men from the Baltimore Longitudinal Study of Aging registry, including 52 with known prostate cancer and 96 age matched controls with no detectable prostatic disease. Plasma selenium was measured at an average time plus or minus standard deviation of 3.83 +/- 1.85 years before the diagnosis of prostate cancer by graphite furnace atomic absorption spectrophotometry. Adjusted odds ratio and 95% confidence interval were computed with logistic regression. RESULTS After correcting for years before diagnosis, body mass index, and smoking and alcohol use history, higher selenium was associated with a lower risk of prostate cancer. Compared with the lowest quartile of selenium (range 8.2 to 10.7 microg./dl.), the odds ratios of the second (10.8 to 11.8), third (11.9 to 13.2) and fourth (13.3 to 18.2) quartiles were 0.15 (95% confidence interval 0.05 to 0.50), 0.21 (0.07 to 0.68) and 0.24 (0.08 to 0.77, respectively, p =0.01). Furthermore, plasma selenium decreased significantly with patient age (p <0.001). CONCLUSIONS Low plasma selenium is associated with a 4 to 5-fold increased risk of prostate cancer. These results support the hypothesis that supplemental selenium may reduce the risk of prostate cancer. Because plasma selenium decreases with patient age, supplementation may be particularly beneficial to older men.
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Affiliation(s)
- J D Brooks
- Department of Urology, Stanford University Medical Center, Stanford, California, USA
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25
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Brooks JD, Metter EJ, Chan DW, Sokoll LJ, Landis P, Nelson WG, Muller D, Andres R, Carter HB. Plasma selenium level before diagnosis and the risk of prostate cancer development. J Urol 2001; 166:2034-8. [PMID: 11696701] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/22/2023]
Abstract
PURPOSE Epidemiological studies and a randomized intervention trial suggest that the risk of prostate cancer may be reduced by selenium intake. We investigated whether plasma selenium level before diagnosis correlated with the risk of later developing prostate cancer. MATERIALS AND METHODS A case control study was performed on men from the Baltimore Longitudinal Study of Aging registry, including 52 with known prostate cancer and 96 age matched controls with no detectable prostatic disease. Plasma selenium was measured at an average time plus or minus standard deviation of 3.83 +/- 1.85 years before the diagnosis of prostate cancer by graphite furnace atomic absorption spectrophotometry. Adjusted odds ratio and 95% confidence interval were computed with logistic regression. RESULTS After correcting for years before diagnosis, body mass index, and smoking and alcohol use history, higher selenium was associated with a lower risk of prostate cancer. Compared with the lowest quartile of selenium (range 8.2 to 10.7 microg./dl.), the odds ratios of the second (10.8 to 11.8), third (11.9 to 13.2) and fourth (13.3 to 18.2) quartiles were 0.15 (95% confidence interval 0.05 to 0.50), 0.21 (0.07 to 0.68) and 0.24 (0.08 to 0.77, respectively, p =0.01). Furthermore, plasma selenium decreased significantly with patient age (p <0.001). CONCLUSIONS Low plasma selenium is associated with a 4 to 5-fold increased risk of prostate cancer. These results support the hypothesis that supplemental selenium may reduce the risk of prostate cancer. Because plasma selenium decreases with patient age, supplementation may be particularly beneficial to older men.
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Affiliation(s)
- J D Brooks
- Department of Urology, Stanford University Medical Center, Stanford, California, USA
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Nelson WG, De Marzo AM, Deweese TL, Lin X, Brooks JD, Putzi MJ, Nelson CP, Groopman JD, Kensler TW. Preneoplastic prostate lesions: an opportunity for prostate cancer prevention. Ann N Y Acad Sci 2001; 952:135-44. [PMID: 11795433 DOI: 10.1111/j.1749-6632.2001.tb02734.x] [Citation(s) in RCA: 83] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Environmental factors, especially the diet, play a prominent role in the epidemic of prostate cancer (PCA), in the United States. Many candidate dietary components have been proposed to influence human prostatic carcinogenesis, including fat, calories, fruits and vegetables, anti-oxidants, and various micronutrients, but the specific roles dietary agents play in promoting or preventing PCA remain controversial. We have collected evidence to suggest that GSTP1, the gene encoding the pi-class glutathione S-transferase (GST), may serve a "caretaker" function for prostatic cells. Although GSTP1 can be detected in normal prostatic epithelium, in almost all PCA cases, PCA cells fail to express GSTP1 polypeptides, and lack of GSTP1 expression most often appears to be the result of somatic "CpG island" DNA methylation changes. Loss of GSTP1 function also appears to be characteristic of prostatic epithelial neoplasia (PIN) lesions, thought to represent PCA precursors. We have recently learned that a new candidate early PCA precursor lesion, proliferative inflammatory atrophy (PIA), characterized by proliferating prostatic cells juxtaposed to inflammatory cells, contains epithelial cells that express high levels of GSTP1. These findings have formed the basis for a new model of prostatic carcinogenesis, in which prostatic cells in PIA lesions, subjected to a barrage of inflammatory oxidants, induce GSTP1 expression as a defense against oxidative genome damage. When cells with defective GSTP1 genes appear amongst the PIA cells, such cells become vulnerable to oxidants and electrophiles that inflict genome damage that tends to promote neoplastic transformation to PIN and PCA cells. Subsequently, PIN and PCA cells with defective GSTPI genes remain vulnerable to similar stresses tending to promote malignant progression. This new model for prostatic carcinogenesis has implications for the design of new prostate cancer prevention strategies. Rational prevention approaches might include: (i) restoration of GSTPI expression via treatment with inhibitors of CpG methylation, (ii) compensation for inadequate GSTPI activity via treatment with inducers of general GST activity, and (iii) abrogation of genome-damaging stresses via avoidance of exogenous carcinogens and/or reduction of endogenous carcinogenic (particularly oxidant) stresses.
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Affiliation(s)
- W G Nelson
- The Johns Hopkins Comprehensive Cancer Center, Baltimore, Maryland 21231-1000, USA.
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Lin X, Tascilar M, Lee WH, Vles WJ, Lee BH, Veeraswamy R, Asgari K, Freije D, van Rees B, Gage WR, Bova GS, Isaacs WB, Brooks JD, DeWeese TL, De Marzo AM, Nelson WG. GSTP1 CpG island hypermethylation is responsible for the absence of GSTP1 expression in human prostate cancer cells. Am J Pathol 2001; 159:1815-26. [PMID: 11696442 PMCID: PMC1867052 DOI: 10.1016/s0002-9440(10)63028-3] [Citation(s) in RCA: 145] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
GSTP1 CpG island hypermethylation is the most common somatic genome alteration described for human prostate cancer (PCA); lack of GSTP1 expression is characteristic of human PCA cells in vivo. We report here that loss of GSTP1 function may have been selected during the pathogenesis of human PCA. Using a variety of techniques to detect GSTP1 CpG island DNA hypermethylation in PCA DNA, we found only hypermethylated GSTP1 alleles in each PCA cell in all but two PCA cases studied. In these two cases, CpG island hypermethylation was present at only one of two GSTP1 alleles in PCA DNA. In one of the cases, DNA hypermethylation at one GSTP1 allele and deletion of the other GSTP1 allele were evident. In the other case, an unmethylated GSTP1 allele was detected, accompanied by abundant GSTP1 expression. GSTP1 CpG island DNA hypermethylation was responsible for lack of GSTP1 expression by LNCaP PCA cells: treatment of the cells with 5-azacytidine (5-aza-C), an inhibitor of DNA methyltransferases, reversed the GSTP1 promoter DNA hypermethylation, activated GSTP1 transcription, and restored GSTP1 expression. GSTP1 promoter activity, assessed via transfection of GSTP1 promoter-CAT reporter constructs in LNCaP cells, was inhibited by SssI-catalyzed CpG dinucleotide methylation. Remarkably, although selection for loss of GSTP1 function may be inferred for human PCA, GSTP1 did not act like a tumor suppressor gene, as LNCaP cells expressing GSTP1, either after 5-aza-C treatment or as a consequence of transfection with GSTP1 cDNA, grew well in vitro and in vivo. Perhaps, GSTP1 inactivation may render prostatic cells susceptible to additional genome alterations, caused by electrophilic or oxidant carcinogens, that provide a selective growth advantage.
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Affiliation(s)
- X Lin
- Department of Oncology, The Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
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Baynes RE, Brooks JD, Budsaba K, Smith CE, Riviere JE. Mixture effects of JP-8 additives on the dermal disposition of jet fuel components. Toxicol Appl Pharmacol 2001; 175:269-81. [PMID: 11559026 DOI: 10.1006/taap.2001.9259] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Aliphatic and aromatic components in formulated jet fuels can cause occupational dermatitis. However, the influence of JP-8 performance additives (DIEGME, 8Q21, and Stadis450) on the dermal disposition of fuel components is not well understood. These additives are formulated with commercial Jet-A to form military JP-8 fuel. The purpose of this study is to assess the influence of these additives on the dermal disposition of marker aromatic and aliphatic components, naphthalene and dodecane, respectively. Porcine skin sections in an in vitro system were used to characterize chemical-biological interactions that modulate diffusion of jet fuel components and isolated perfused porcine skin flaps (IPPSFs) were used to evaluate diffusion in a viable skin model with an intact microvasculature. In these 5-h studies, Jet-A, Jet-A + DIEGME, Jet-A + 8Q21, and Jet-A + Stadis450, Jet-A + DIEGME + 8Q21, Jet-A + DIEGME + Stadis450, Jet-A + 8Q21 + Stadis450, and JP-8 mixtures were tested. In general, naphthalene absorption (0.76-2.39% dose) was greater than dodecane absorption (0.10-0.84% dose), while the IPPSFs alone demonstrated that dodecane absorption was significantly greater in JP-8 than in Jet-A. Synergistic interactions with 8Q21 + Stadis450 appear to enhance systemic absorption of either naphthalene or dodecane, while DIEGME + Stadis450 increased naphthalene (1.88% dose) and dodecane (2.02% dose) penetration into the skin and fat tissues of IPPSFs. These findings were supported by the fact that 8Q21 + Stadis450 significantly increased dodecane flux and permeability in porcine skin sections, but 8Q21 alone reduced marker diffusion in both membrane systems. Furthermore, dodecane is more likely than naphthalene to remain in the stratum corneum and skin surface at 5 h, and DIEGME mixtures played a significant role in skin and surface retention of both markers. In summary, the data suggest that various combinations of these three performance additives in JP-8 can potentially alter the dermal disposition of aromatic and aliphatic fuel components in skin. More importantly, products of two-factor interactions were not predictable from single-factor exposures and, by extension, cannot be extrapolated to three-factor interactions.
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Affiliation(s)
- R E Baynes
- Center for Cutaneous Toxicology and Residue Pharmacology, North Carolina State University, 4700 Hillsborough Street, Raleigh, NC 27606, USA.
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29
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Brooks JD, Paton VG, Vidanes G. Potent induction of phase 2 enzymes in human prostate cells by sulforaphane. Cancer Epidemiol Biomarkers Prev 2001; 10:949-54. [PMID: 11535546] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/21/2023] Open
Abstract
Two population-based, case-control studies have documented reduced risk of prostate cancer in men who consume cruciferous vegetables. Cruciferae contain high levels of the isothiocyanate sulforaphane. Sulforaphane is known to bolster the defenses of cells against carcinogens through up-regulation of enzymes of carcinogen defense (phase 2 enzymes). Prostate cancer is characterized by an early and near universal loss of expression of the phase 2 enzyme glutathione S-transferase (GST)-pi. We tested whether sulforaphane may act in prostatic cells by increasing phase 2 enzyme expression. The human prostate cancer cell lines LNCaP, MDA PCa 2a, MDA PCa 2b, PC-3, and TSU-Pr1 were treated with 0.1-15 microM sulforaphane in vitro. LNCaP was also treated with an aqueous extract of broccoli sprouts. Quinone reductase enzymatic activity, a surrogate of global phase 2 enzyme activity, was assayed by the menadione-coupled reduction of tetrazolium dye. Expression of NQO-1, GST-alpha, gamma-glutamylcysteine synthetase-heavy and -light chains, and microsomal GST was assessed by Northern blot analysis. Sulforaphane and broccoli sprout extract potently induce quinone reductase activity in cultured prostate cells, and this induction appears to be mediated by increased transcription of the NQO-1 gene. Sulforaphane also induces expression of gamma-glutamylcysteine synthetase light subunit but not the heavy subunit, and this induction is associated with moderate increases in intracellular glutathione levels. Microsomal and alpha-class glutathione transferases were also induced transcriptionally. Sulforaphane induces phase 2 enzyme expression and activity significantly in human prostatic cells. This induction is accompanied by, but not because of, increased intracellular glutathione synthesis. Our findings may help explain the observed inverse correlation between consumption of cruciferae and prostate cancer risk.
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Affiliation(s)
- J D Brooks
- Department of Urology, Stanford University Medical Center, Stanford, California 94305-5118, USA.
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Abstract
Interactions between chemicals in a mixture and interactions of mixture components with the skin can significantly alter the rate and extent of percutaneous absorption, as well as the cutaneous disposition of a topically applied chemical. The predictive ability of dermal absorption models, and consequently the dermal risk assessment process, would be greatly improved by the elucidation and characterization of these interactions. Pentachlorophenol (PCP), a compound known to penetrate the skin readily, was used as a marker compound to examine mixture component effects using in vitro porcine skin models. PCP was administered in ethanol or in a 40% ethanol/60% water mixture or a 40% ethanol/60% water mixture containing either the rubefacient methyl nicotinate (MNA) or the surfactant sodium lauryl sulfate (SLS), or both MNA and SLS. Experiments were also conducted with 14C-labelled 3,3',4,4'-tetrachlorobiphenyl (TCB) and 3,3',4,4',5-pentachlorobiphenyl (PCB). Maximal PCP absorption was 14.12% of the applied dose from the mixture containing SLS, MNA, ethanol and water. However, when PCP was administered in ethanol only, absorption was only 1.12% of the applied dose. There were also qualitative differences among the absorption profiles for the different PCP mixtures. In contrast with the PCP results, absorption of TCB or PCB was negligible in perfused porcine skin, with only 0.14% of the applied TCB dose and 0.05% of the applied PCB dose being maximally absorbed. The low absorption levels for the PCB congeners precluded the identification of mixture component effects. These results suggest that dermal absorption estimates from a single chemical exposure may not reflect absorption seen after exposure as a chemical mixture and that absorption of both TCB and PCB are minimal in this model system.
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Affiliation(s)
- J E Riviere
- Center for Cutaneous Toxicology and Residue Pharmacology, College of Veterinary Medicine, North Carolina State University, Raleigh 27606, USA.
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Abstract
AIMS This project aimed to investigate the mechanism of attachment of the vegetative cells and spores of thermophilic bacilli to stainless steel with a view to devising strategies to limit biofilm development and survival. METHODS AND RESULTS Spores and vegetative cells of bacterial isolates were exposed to protein denaturing agents (sodium dodecyl sulphate (SDS) and trypsin) and polysaccharide removing agents (sodium metaperiodate, trichloroacetic acid (TCA) and lysozyme). Treatment with sodium metaperiodate, TCA and lysozyme increased the number of vegetative cells attaching in many of the strains studied, while SDS and trypsin decreased attachment. Spores attached to stainless steel in greater numbers than vegetative cells, and the various treatments had less effect on this attachment than for vegetative cells. Viability of the cells or spores was not an important factor in attachment, as cells and spores rendered non-viable also attached to stainless steel in similar numbers. Coating the stainless steel with skim milk proteins decreased the attachment of both vegetative cells and spores. There was no correlation between the degree of attachment and the amount of extracellular polysaccharide (EPS) produced by each strain, surface hydrophobicity or zeta potential of vegetative cells or spores, though spores were found to be more hydrophobic than vegetative cells. CONCLUSIONS The results suggest that biofilm formation by these thermophilic bacilli is probably a multifactorial process, and that cell-surface proteins play a very important role in the initial process of attachment during the formation of biofilms by these bacteria. SIGNIFICANCE AND IMPACT OF THE STUDY This information will provide direction for developing improved cleaning systems to control biofilms of thermophilic bacilli in dairy manufacturing plants.
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Affiliation(s)
- S G Parkar
- Institute of Food, Nutrition and Human Health, Massey University, Palmerston North, New Zealand
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Abstract
Strategies for reducing the occurrence of prostate cancers will be critical in limiting the morbidity and mortality of this disease. The long latency period of prostate tumors and improved understanding of prostate carcinogenesis suggest opportunities for effective preventive measures. Because androgen is integral to prostatic carcinogenesis, several preventive strategies under investigation target the androgen axis. Epidemiologic and basic studies implicate dietary factors in prostate cancer development and suggest that altering diet may influence prostate cancer risk and progression. Many of the micronutrients with preventive potential have antioxidant properties; cellular defenses against oxidative stresses are likely to be crucial in reducing prostate carcinogenesis. This article summarizes the current status and opportunities in prostate cancer prevention.
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Affiliation(s)
- S E DePrimo
- Department of Urology, Stanford University School of Medicine, California 94305-5118, USA
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33
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Abstract
An impedance splitting method was used to detect Bacillus stearothermophilus in suspension and attached to stainless steel surfaces. The effects of bacterial metabolism on the impedance of the culture medium and the ionic layers of the measuring electrodes were recorded using the BacTrac 4000 microorganism growth analyser. Impedance changes were measured at 55 degrees C. Seven of the eight media produced changes in the electrode impedance (E-value) and all media produced negligible changes in the impedance of the culture medium (M-value). Good correlations were obtained between cell numbers and the E-value measured over 18 h (r > 0.9) for the two strains of B. stearothermophilus tested in trypticase soy broth. The E-value correlations were used to estimate the numbers of both vegetative and spore forms of B. stearothermophilus as either planktonic or adhered cells. For the detection of B. stearothermophilus using impedance, only methods where the E-value impedance is recorded, can be used.
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Affiliation(s)
- S H Flint
- New Zealand Dairy Research Institute, Palmerston North.
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Abstract
Gleason grade 1 prostatic adenocarcinoma is defined by its gland architecture, which resembles that of benign prostate more than any other grade. It is characterized by closely spaced glands and expansile tumor border. Cytoplasm is clear to pale, superficially identical to benign nodular hyperplasia (BPH). However, there is recent evidence that prostatic "clear-cell carcinoma," including grade 1, has cytoplasm whose composition is distinctively different from BPH, being filled with lipid rather than with the protein-rich granules that characterize benign secretory cells or the nongranular protein matrix of other prostate cancers. We reasoned that grade 1 cancer might also have additional distinctive cellular features; we tested this hypothesis by observations on 17 grade 1 carcinoma foci found as components of transition zone clear-cell cancers. Unlike BPH secretory cells, cells of grade 1 cancer were uniformly large with even, straight borders laterally and luminally. Nuclei appeared sometimes benign but were fixed in a basal row dissimilar to the uneven distribution in BPH. Nuclear pyknotic foci, blue-tinged cytoplasm, and abundant dense luminal secretion were distinctively common. Immunostain for glutathione-S transferase was negative in grade 1 cancer but lightly positive in BPH secretory cells. These cytologic findings were proposed to be useful as diagnostic clues, especially in small-needle biopsy samples, in which architecture may be difficult to interpret. HUM PATHOL 32:441-446.
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Affiliation(s)
- J E McNeal
- Department of Urology, Stanford University Medical Center, Stanford, CA 94305, USA
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35
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Abstract
Recently developed complementary DNA (cDNA) microarray technology allows simultaneous assessment of expression on many hundreds or thousands of genes simultaneously. This technology holds great promise for providing new insights into prostate carcinogenesis that will reveal new targets for preventive intervention strategies. In addition, this technology will deepen understanding of the means by which putative preventive compounds exert their effects, generating molecular genetic biomarkers of treatment efficacy. Several putative preventive agents are currently under investigation, and development of novel preventive strategies poses significant challenges. High throughput approaches, such as cDNA microarrays, will speed discovery and progress in prostate cancer chemoprevention.
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Affiliation(s)
- E D Williams
- St. Vincent's Institute of Medical Research, Fitzroy, Australia
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36
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Riviere JE, Smith CE, Budsaba K, Brooks JD, Olajos EJ, Salem H, Monteiro-Riviere NA. Use of methyl salicylate as a simulant to predict the percutaneous absorption of sulfur mustard. J Appl Toxicol 2001; 21:91-9. [PMID: 11288131 DOI: 10.1002/jat.718] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Exposure to chemical vesicants such as sulfur mustard (HD) continues to be a threat to military forces requiring protectant strategies to exposure to be evaluated. Methyl salicylate (MS) has historically been the simulant of choice to assess HD exposure. The purpose of this study was to compare the percutaneous absorption and skin deposition of MS to HD in the isolated perfused porcine skin flap (IPPSF). The HD data were obtained from a previously published study in this model wherein 400 microg cm(-2) of ](14)C[-MS or ](14)C[-HD in ethanol were topically applied to 16 IPPSFs and experiments were terminated at 2, 4 or 8 h. Perfusate was collected at increasing time intervals throughout perfusion. Radioactivity was determined in perfusate and skin samples. Perfusate flux profiles were fitted to a bi-exponential model Y(t) = A(e(-bt) - e(-dt)) and the area under the curve (AUC), peak flux and time to peak flux were determined. Sulfur mustard had more pronounced and rapid initial flux parameters (P < 0.05). The AUCs determined from observed and model-predicted parameters were not statistically different, although the mean HD AUC was 40--50% greater than MS. The HD skin and fat levels were up to twice those seen with MS, but had lower stratum corneum and residual skin surface concentrations (P < 0.05). Compared with other chemicals studied in this model, HD and MS cutaneous disposition were very similar, supporting the use of MS as a dermal simulant for HD exposure.
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Affiliation(s)
- J E Riviere
- Center for Cutaneous Toxicology and Residue Pharmacology, College of Veterinary Medicine, North Carolina State University, Raleigh, NC 27606, USA.
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37
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Tchou JC, Lin X, Freije D, Isaacs WB, Brooks JD, Rashid A, De Marzo AM, Kanai Y, Hirohashi S, Nelson WG. GSTP1 CpG island DNA hypermethylation in hepatocellular carcinomas. Int J Oncol 2000; 16:663-76. [PMID: 10717233 DOI: 10.3892/ijo.16.4.663] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Glutathione S-transferases, enzymes that defend cells against damage mediated by oxidant and electrophilic carcinogens, may be critical determinants of cancer pathogenesis. We report here that the pathogenesis of hepatocellular carcinoma (HCC), one of the most common cancers in the world, frequently involves an accumulation of somatic <CpG island> DNA methylation changes at GSTP1, the gene encoding the pi-class glutathione S-transferase. For our study, Hep3B HCC cells and a cohort of 20 HCC tissue specimens were subjected to analysis for GSTP1 expression and for somatic GSTP1 alterations. GSTP1 <CpG island> DNA hypermethylation in HCC DNA was assessed by Southern blot analysis, via a polymerase chain reaction (PCR) assay, and by using a genomic sequencing approach. Hep3B HCC cells failed to express GSTP1 mRNA or GSTP1 polypeptides. Similarly, HCC cells in 19 of 20 HCC cases were devoid of GSTP1 polypeptides. By Southern blot analysis, DNA from Hep3B HCC cells displayed abnormal GSTP1 <CpG island> hypermethylation. Treatment of Hep3B HCC cells in vitro with the DNA methyltransferase inhibitor 5-aza-deoxycytidine both reversed GSTP1 <CpG island> DNA hypermethylation and restored GSTP1 expression. Using a PCR assay, somatic GSTP1 <CpG island> DNA hypermethylation was also detected in HCC DNA from 17 of 20 HCC cases. Genomic sequencing analyses, undertaken to map 5-methyldeoxycytidine nucleotides located at the GSTP1 transcriptional regulatory region, frequently detected somatic DNA hypermethylation near the gene promoter in HCC DNA. The data indicate that GSTP1 <CpG island> DNA hypermethylation changes appear frequently in human HCC. In addition, the data raise the possibility that somatic GSTP1 inactivation, via <CpG island> hypermethylation, may contribute to the pathogenesis of HCC.
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Affiliation(s)
- J C Tchou
- The Johns Hopkins Oncology Center and Johns Hopkins University School of Medicine, Baltimore, MD 21287-2411, USA
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Qiao GL, Chang SK, Brooks JD, Riviere JE. Dermatoxicokinetic modeling of p-nitrophenol and its conjugation metabolite in swine following topical and intravenous administration. Toxicol Sci 2000; 54:284-94. [PMID: 10774810 DOI: 10.1093/toxsci/54.2.284] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The development of a dermatotoxicokinetic (dTK) model for p-nitrophenol (PNP), a common metabolite from a variety of compounds and a biomarker of organophosphate (OP) insecticide exposure, may facilitate the kinetic modeling and risk assessment strategy for its parent compounds. In order to quantify and then clarify in vivo-in vitro correlation of PNP disposition, multicompartment kinetic models were formulated. Female weanling pigs were dosed with [14C]PNP intravenously (150 microg in ethanol, n = 4) or topically onto non-occluded abdominal skin (300 microg/7.5cm2 in ethanol, n = 4). PNP and p-nitrophenyl-beta-D-glucuronide (PNP-G) profiles were determined in plasma and urine in addition to total 14C quantitation in many other samples. Disposition parameters (rate constants, Ftop, T12, T1/2Ka, AUC, Vss, Clp, MAT, and MRT) and the simulated chemical mass-time profiles on the dosed skin surface and in the local, systemic, and excretory compartments were also determined. Total recoveries of 97.17 +/- 4.18% and 99.80 +/- 2.41% were obtained from topical and intravenous experiments, respectively. Ninety-six hours after topical and intravenous application, 70.92 +/- 9.72% and 98.65 +/- 2.43% of the dose were excreted via urine, and 0.55 +/- 0.16% and 0.51 +/- 0.10% via the fecal route, respectively. Peak excretion rate and time were also determined. It was suggested by experimental observation and modeling that urinary 14C excretion correlates with the systemic tissue depletion profile well and may be used as a biomarker of PNP exposure. This study also supports the strategy of using urinary PNP as a biomonitoring tool for OP pesticide exposure, although some precautions have to be taken. The strategy used in this study will be useful in comprehensive dTK modeling in dermal risk assessment and transdermal drug delivery.
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Affiliation(s)
- G L Qiao
- National Institute for Occupational Safety and Health, CDC, Morgantown, West Virginia 26505-2888, USA.
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Monteiro-Riviere NA, Van Miller JP, Simon G, Joiner RL, Brooks JD, Riviere JE. Comparative in vitro percutaneous absorption of nonylphenol and nonylphenol ethoxylates (NPE-4 and NPE-9) through human, porcine and rat skin. Toxicol Ind Health 2000; 16:49-57. [PMID: 10798622 DOI: 10.1177/074823370001600201] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The purpose of this study was to assess the percutaneous absorption of nonylphenol (NP) and the nonylphenol ethoxylates, NPE-4 and NPE-9, in human, porcine and rat skin. In vitro studies with the NPEs were conducted for 8 h in flowthrough diffusion cells using topical solutions of 0.1, 1.0 and 10% in PEG-400 or 1% in water (NPE-9 only). NP absorption was assessed as a 1% solution in PEG-400. All compounds were 14C ring-labeled and radioactivity in perfusate was monitored over time. Skin deposition was measured at the termination of the experiment. Absorption into perfusate and total penetration (compound absorbed plus compound sequestered in skin) were calculated. Absorption of NPE-4, NPE-9 and NP was similar across all species at less than 1% of the applied dose over 8 h. Penetration was generally below 5% of applied dose, the majority located in the stratum corneum. In all species and for both NPEs, the fraction of dose absorbed was highest for the lowest applied dose. Absorptions expressed as actual mass absorbed over 8 h were similar (approximately 0.3 microg/cm2) across all concentrations. Penetration, but not absorption, was greater from a water vehicle compared to a PEG-400 vehicle, particularly in rat skin. These studies suggest that NP, NPE-4 and NPE-9 were minimally absorbed across skin from all three species. Fractional absorption was concentration-dependent, making the actual absorbed flux constant across all doses.
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Affiliation(s)
- N A Monteiro-Riviere
- Center for Cutaneous Toxicology and Residue Pharmacology, North Carolina State University, Raleigh 27606, USA.
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40
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Brooks JD, Paton V. Potent induction of carcinogen defence enzymes with sulforaphane, a putative prostate cancer chemopreventive agent. Prostate Cancer Prostatic Dis 1999; 2:S8. [PMID: 12496788 DOI: 10.1038/sj.pcan.4500334] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Riviere JE, Brooks JD, Monteiro-Riviere NA, Budsaba K, Smith CE. Dermal absorption and distribution of topically dosed jet fuels jet-A, JP-8, and JP-8(100). Toxicol Appl Pharmacol 1999; 160:60-75. [PMID: 10502503 DOI: 10.1006/taap.1999.8744] [Citation(s) in RCA: 58] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Dermal exposure to jet fuels has received increased attention with the recent release of newer fuels with novel performance additives. The purpose of these studies was to assess the percutaneous absorption and cutaneous disposition of topically applied (25 microl/5 cm(2)) neat Jet-A, JP-8, and JP-8(100) jet fuels by monitoring the absorptive flux of the marker components 14C naphthalene and (3)H dodecane simultaneously applied nonoccluded to isolated perfused porcine skin flaps (IPPSF) (n = 4). Absorption of 14C hexadecane was estimated from JP-8 fuel. Absorption and disposition of naphthalene and dodecane were also monitored using a nonvolatile JP-8 fraction reflecting exposure to residual fuel that might occur 24 h after a jet fuel spill. In all studies, perfusate, stratum corneum, and skin concentrations were measured over 5 h. Naphthalene absorption had a clear peak absorptive flux at less than 1 h, while dodecane and hexadecane had prolonged, albeit significantly lower, absorption flux profiles. Within JP-8, the rank order of absorption for all marker components was (mean +/- SEM % dose) naphthalene (1.17 +/- 0.07) > dodecane (0.63 +/- 0.04) > hexadecane (0.18 +/- 0.08). In contrast, deposition within dosed skin showed the reverse pattern. Naphthalene absorption into perfusate was similar across all fuel types, however total penetration into and through skin was highest with JP-8(100). Dodecane absorption and total penetration was greatest from JP-8. Absorption of both markers from aged JP-8 was lower than other fuels, yet the ratio of skin deposition to absorption was greatest for this treatment group. In most exposure scenarios, absorption into perfusate did not directly correlate to residual skin concentrations. These studies demonstrated different absorption profiles for the three marker compounds, differential effects of jet fuel types on naphthalene and dodecane absorption, and uncoupling of perfusate absorption from skin disposition.
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Affiliation(s)
- J E Riviere
- Center for Cutaneous Toxicology and Residue Pharmacology, College of Veterinary Medicine, Raleigh, North Carolina 27606, USA.
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Abstract
Thermophilic streptococci were isolated from biofilms on stainless steel samples exposed to pasteurized skimmed milk and from dairy products from a dairy manufacturing plant. The phenotypic characters of these isolates were distinct from those of other thermophilic streptococci of dairy origin (Streptococcus thermophilus and Streptococcus bovis). Genotypic data [restriction endonuclease analysis, ribotyping, random amplified polymorphic DNA (RAPD) profiles, DNA-DNA hybridization and G + C contents] support the classification of these isolates as a new species. The sequence of the 16S rRNA was compared with that of 29 species of streptococci and shown to be significantly different. The sequence of the 16S-23S rRNA intergenic spacer region also differed from published sequences of closely related species. A fluorescent in situ hybridization probe prepared to a specific part of the 16S rRNA gene sequence was able to distinguish the unknown isolates from reference isolates of S. thermophilus and S. bovis. It is proposed that these thermophilic streptococcal isolates from a dairy environment be classified in the genus Streptococcus as a new species, Streptococcus waius (from waiu, the New Zealand Maori word for milk). The type strain is 3/1T (= NZRCC 20100T).
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MESH Headings
- Animals
- Base Composition
- Base Sequence
- Biofilms/growth & development
- DNA, Bacterial/chemistry
- DNA, Bacterial/genetics
- DNA, Ribosomal/chemistry
- DNA, Ribosomal/genetics
- Dairying
- Genes, rRNA
- Hot Temperature
- In Situ Hybridization, Fluorescence
- Milk/microbiology
- Molecular Sequence Data
- Nucleic Acid Hybridization
- RNA, Ribosomal, 16S/genetics
- RNA, Ribosomal, 23S/genetics
- Random Amplified Polymorphic DNA Technique
- Restriction Mapping
- Sequence Analysis, DNA
- Stainless Steel
- Streptococcus/classification
- Streptococcus/genetics
- Streptococcus/isolation & purification
- Streptococcus/physiology
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Affiliation(s)
- S H Flint
- Institute of Food Nutrition and Human Health, Massey University, Palmerston North, New Zealand.
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43
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Pruthi RS, Angell SK, Brooks JD, Gill H. Partial nephrectomy and caval thrombectomy for renal cell carcinoma in a solitary kidney with an accessory renal vein. BJU Int 1999; 83:142-3. [PMID: 10233469 DOI: 10.1046/j.1464-410x.1999.00853.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Affiliation(s)
- R S Pruthi
- Department of Urology, Stanford University School of Medicine, Stanford, CA, USA
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44
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Brooks JD, Weinstein M, Lin X, Sun Y, Pin SS, Bova GS, Epstein JI, Isaacs WB, Nelson WG. CG island methylation changes near the GSTP1 gene in prostatic intraepithelial neoplasia. Cancer Epidemiol Biomarkers Prev 1998; 7:531-6. [PMID: 9641498] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Prostate intraepithelial neoplasia (PIN) is a purported prostate cancer precursor lesion and a candidate biomarker for efficacy assessment in prostate cancer chemoprevention trials. Loss of expression of the pi-class glutathione S-transferase enzyme GSTP1, which is associated with the hypermethylation of deoxycytidine residues in the 5'-regulatory CG island region of the GSTP1 gene, is a near-universal finding in human prostate cancer. GSTP1 expression was assessed by immunohistochemistry in 60 high-grade PIN samples adjacent to and distant from prostate adenocarcinoma. Whereas abundant enzyme polypeptide expression was evident in all normal prostatic tissues, all samples of high-grade PIN and adenocarcinoma were completely devoid of GSTP1. DNA from 10 high-grade PIN lesions was analyzed for GSTP1 CG island methylation changes using a PCR technique targeting a polymorphic (ATAAA)n repeat sequence in the promoter region of the GSTP1 gene. Somatic GSTP1 CG island methylation changes were detected in DNA from 7 of the 10 PIN lesions. Allele discrimination was possible for 5 of the 10 DNA samples: 2 of the 5 samples exhibited DNA methylation changes at both alleles; whereas 3 samples displayed no DNA methylation changes at either allele. GSTP1 CG island methylation changes were present in each of the five homozygous samples. Hypermethylation of the 5'-regulatory region of the GSTP1 gene may serve as an important molecular genetic biomarker for both prostate cancer and PIN. The finding of frequent GSTP1 methylation changes in PIN and prostate cancer supports a role for PIN lesions as a prostate cancer precursor and may provide insight to the molecular pathogenesis of prostate cancer.
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Affiliation(s)
- J D Brooks
- Department of Urology, The Johns Hopkins University School of Medicine, Baltimore, Maryland 21287-2101, USA
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45
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Brooks JD, Chao WM, Kerr J. Male pelvic anatomy reconstructed from the visible human data set. J Urol 1998; 159:868-72. [PMID: 9474171] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
PURPOSE To improve understanding of the male pelvic anatomy pertinent to urological surgery we performed computer generated, 3-dimensional reconstruction of the male pelvis from the Visible Human data set. MATERIALS AND METHODS A total of 18 discrete anatomical structures, including the prostate, bladder, urethra, rectum and pelvic musculature, was segmented from the Visible Human cross-sectional data obtained from the National Library of Medicine. Using high speed computing and rendering software, 3-dimensional models of each structure were generated and assembled into composite figures. RESULTS These reconstructions offer a revised view of pelvic anatomy as it has been traditionally depicted. The lateral surfaces of the levator ani muscle are oriented vertically in the pelvis and directly applied to the entire lateral surface of the prostate. The bladder rests primarily anterior to the prostate rather than directly above it, as has been commonly depicted. In the cross-sectional data and reconstructions the trigone and anterior fibromuscular stroma of the prostate appear as a single unit in continuity, which may have functional implications for understanding the mechanisms of continence at the bladder neck. The striated urethral sphincter appears circular with abundant tissue posteriorly. This sphincteric muscle has greater length anteriorly than posteriorly. CONCLUSIONS These 3-dimensional reconstructions provide unique insights into male pelvic anatomy. They are a useful teaching tool for investigation and virtual reality modeling of the male pelvis.
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Affiliation(s)
- J D Brooks
- Department of Urology, James Buchanan Brady Urological Institute, Johns Hopkins Medical Institutions, Baltimore, Maryland, USA
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46
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Qiao GL, Brooks JD, Riviere JE. Pentachlorophenol dermal absorption and disposition from soil in swine: effects of occlusion and skin microorganism inhibition. Toxicol Appl Pharmacol 1997; 147:234-46. [PMID: 9439719 DOI: 10.1006/taap.1997.8288] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Residue of the environmentally relevant biocide pentachlorophenol (PCP) is found mainly in soil, making dermal contact one of the primary routes for PCP exposure. To quantify exposure effects on dermal absorption and systemic disposition, [14C-UL]PCP was dosed nonocclusively or occlusively at 40 micrograms/cm2 in a soil-based mixture in an in vivo swine model. Additionally, antibiotics were also codosed with occlusive PCP in soil to examine the impacts of skin microbial PCP biodegradation on total dermal absorption. Under nonocclusive, occlusive, and occlusive-antibiotic conditions, total radiolabel absorption by 408 hr was 29.08, 100.72, and 86.21% dose, respectively. Tissue accumulation of PCP and its labeled metabolite(s) was very significant in swine since one-half to two-thirds of the absorbed dose was still present in tissues by 17 days after PCP dermal exposure. High 14C concentrations were found in liver, kidney, lung, ovary, and uterus. Urine and fecal routes were equally important for label excretion from the body. Occlusion enhanced total dermal absorption and changed the shape of the absorption profiles in the blood and plasma. Skin microorganism inhibition retarded 14C dermal absorption, altered local and systemic tissue distribution, and increased plasma/blood concentration ratios, suggesting skin microbial PCP degradation might play an important role in the altered absorption and disposition by occlusion. This study demonstrated significant dermal absorption and extensive tissue persistence of PCP after soil exposure. Occlusion and skin microflora growth may greatly impact dermal absorption, cutaneous disposition, and systemic toxic input. Therefore, exposure-specific PCP absorption and disposition profiles must be taken into consideration in risk analysis.
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Affiliation(s)
- G L Qiao
- Cutaneous Pharmacology and Toxicology Center, College of Veterinary Medicine, North Carolina State University, Raleigh 27606, USA.
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47
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Abstract
Colonic metaplasia and primary bladder adenocarcinoma are relatively uncommon entities that can have similar gross clinical appearances. Examples of colonic metaplasia histologically mimicking cancer have only rarely been reported. We retrospectively analyzed 38 cases of cystitis glandularis (18 cases of colonic metaplasia), 12 cases of adenocarcinoma of urinary bladder (two well-differentiated, WDA), and one in situ adenocarcinoma from the surgical pathology files of Johns Hopkins Hospital. Nine patients with colonic metaplasia had widespread lesions. Two showed superficial muscularis propria involvement, mimicking adenocarcinoma; one of these cases had been diagnosed as infiltrating WDA at both an academic center and a community hospital. Dissecting mucin pools were focally seen in four cases of widespread colonic metaplasia, also mimicking cancer. One of the nine cases showed minimal cytological atypia, but no cases showed mitoses or signet ring cells. Distinguishing WDA from colonic metaplasia was the finding in WDA of infiltrative architectural pattern (two of two), extensive muscle invasion (two of two), moderate anaplasia (one of two), mitotic figures (two of two), and extensive mucinous pools (one of two). The diagnosis of adenocarcinoma in situ was based on anaplasia. Clinically, colonic metaplasia may resemble cancer. Histologically, colonic metaplasia may mimic cancer based on extensive involvement of the lamina propria, focal mucinous pools, focal muscularis propria involvement, focal mild cytological atypia, and rare mitoses. Despite overlapping features with colonic metaplasia, the diagnosis of WDA is based on the greater degree and extent of these atypical findings in cancer.
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Affiliation(s)
- L B Jacobs
- Department of Pathology, The University of Kentucky College of Medicine, Lexington, USA
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48
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Abstract
The quality of milk products is threatened by the formation of biofilms of thermophilic streptococci on the internal surfaces of plate heat exchangers used in milk processing. Although attachment to stainless steel surfaces is one of the first stages in the development of a biofilm, the mechanisms involved in attachment have not been reported. The cell surface properties of 12 strains of thermophilic streptococci were examined to determine their importance in attachment to stainless steel surfaces. Hydrophobicity, extracellular polysaccharide production and cell surface charge varied between the different strains but could not be related to numbers attaching. Treating the cells with sodium metaperiodate, lysozyme or trichloroacetic acid to disrupt cell surface polysaccharide had no effect on attachment. Treatment with trypsin or sodium dodecyl sulphate to remove cell surface proteins resulted in a 100-fold reduction in the number of bacteria attaching. This result suggests that the surface proteins of the thermophilic streptococci are important in their attachment to stainless steel.
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Affiliation(s)
- S H Flint
- Department of Food Technology, Massey University, Palmerston North, New Zealand
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49
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Abstract
The use of the Malthus conductance growth analyser for the detection of Streptococcus bovis attached to stainless steel surface was evaluated. A comparison between the results from acridine orange epifluorescence direct counts, swab recovery viable count and conductance estimates of attached cell concentrations, based on calibrations for planktonic cells, showed that the conductance results were up to 2 log10 greater than the epifluorescence results and the swab counts. The growth rates of planktonic and attached cells were similar over 16 h using the Malthus technique. This suggests that the Malthus technique detects more attached cells of Strep. bovis than epifluorescence microscopy or swab recovery.
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Affiliation(s)
- S H Flint
- Massey University, Palmerston North, New Zealand
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50
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Walsh PC, Brooks JD. The Swedish prostate cancer paradox. JAMA 1997; 277:497-8. [PMID: 9020276] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
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