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Lent AB, Garrido CO, Baird EH, Viela R, Harris RB. Racial/Ethnic Disparities in Health and Life Insurance Denial Due to Cancer among Cancer Survivors. Cancer Epidemiol Biomarkers Prev 2022. [PMID: 35775218 DOI: 10.1158/1055-9965.epi-22-0477] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
PURPOSE OF THE STUDY This study examined racial/ethnic differences in health and life insurance denial due to cancer among cancer survivors after the passage of the Affordable Care Act (ACA). METHODS A cross sectional study was conducted using Behavioral Risk Factor Surveillance System data from 2012 through 2020. The dependent variable asked: "Were you ever denied health insurance or life insurance coverage because of your cancer?" Cancer survivors were included if they were diagnosed with cancer after the Affordable Care Act (N=14,815). Descriptive statistics using weighted percentages summarized the results. Logistic regressions provided odds of insurance denial due to cancer across racial/ethnic groups: Non-Hispanic White, Black, and Other/mixed race; and Hispanic. Models adjusted for age, sex, income, and employment status. Interaction terms for age, sex, income, and employment were included in regression models to assess for effect modification. RESULTS Weighted chi-squares identified statistically significant differences (p<0.05) between those who were denied or not denied insurance across sex, age, race/ethnicity, income, and employment. Adjusted weighted logistic regressions found significantly higher odds of insurance denial for Blacks (OR:3.01, 95%CI:1.78, 5.08), Other/mixed race (OR:2.10, 95%CI: 1.13, 3.90), and Hispanics (OR:2.16, 95%CI:1.05, 4.46) compared to Non-Hispanic Whites. Sex, income, and employment status were significant effect modifiers. Compared to White women, Black women were significantly more likely to be denied health and life insurance. Compared to Whites with incomes >$25K to <$50K and >$50K to <$75K, Blacks were more likely to be denied insurance (OR:3.50, 95%CI:1.42, 8.66 and OR:7.72, 95%CI: 2.40, 24.81). CONCLUSIONS Despite health insurance denial for pre-existing conditions being illegal under the ACA, cancer survivors report racial/ethnic disparities in health and life insurance denial due to their cancer diagnosis. This denial may be particularly harmful for people of color who are already financially vulnerable due to their cancer diagnosis and exacerbate racial/ethnic cancer disparities.
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Harris RB, Mack MR, Bryant J, Theobald EJ, Freeman S. Reducing achievement gaps in undergraduate general chemistry could lift underrepresented students into a "hyperpersistent zone". Sci Adv 2020; 6:eaaz5687. [PMID: 32577510 PMCID: PMC7286681 DOI: 10.1126/sciadv.aaz5687] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/19/2019] [Accepted: 04/13/2020] [Indexed: 05/15/2023]
Abstract
Students from underrepresented groups start college with the same level of interest in STEM majors as their peers, but leave STEM at higher rates. We tested the hypothesis that low grades in general chemistry contribute to this "weeding," using records from 25,768 students. In the first course of a general chemistry series, grade gaps based on binary gender, race/ethnicity, socioeconomic status, and family education background ranged from 0.12 to 0.54 on a four-point scale. Gaps persisted when the analysis controlled for academic preparation, indicating that students from underrepresented groups underperformed relative to their capability. Underrepresented students were less likely than well-represented peers to persist in chemistry if they performed below a C-, but more likely to persist if they got a C or better. This "hyperpersistent zone" suggests that reducing achievement gaps could have a disproportionately large impact on efforts to achieve equity in STEM majors and professions.
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Affiliation(s)
- R. B. Harris
- Department of Biology, University of Washington, Box 355320, Seattle, WA 98195-5320, USA
| | - M. R. Mack
- Department of Chemistry, University of Washington, Box 351700, Seattle, WA 98195-1700, USA
| | - J. Bryant
- Department of Chemistry, University of Washington, Box 351700, Seattle, WA 98195-1700, USA
| | - E. J. Theobald
- Department of Biology, University of Washington, Box 355320, Seattle, WA 98195-5320, USA
| | - S. Freeman
- Department of Biology, University of Washington, Box 355320, Seattle, WA 98195-5320, USA
- Corresponding author.
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Florea A, Brown HE, Harris RB, Oren E. Ethnic Disparities in Gastric Cancer Presentation and Screening Practice in the United States: An Analysis of 1997–2010 SEER-Medicare Data. Cancer Epidemiol Biomarkers Prev 2018. [DOI: 10.1158/1055-9965.epi-18-0059] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Abstract
Describe differences in Helicobacter pylori (H. pylori) screening among a Surveillance, Epidemiology and End Results (SEER)-Medicare elderly population by ethnicity, place of birth, and gastric cancer (GC)-related conditions, as chronic infection with H. pylori is the strongest risk factor for distal GC. Methods: We used the National Cancer Institute's population-based SEER-Medicare cancer database for GC (1997–2010). We extracted demographic, location and disease staging information from the SEER data file, Patient Entitlement and Diagnosis Summary File. We obtained information on frequencies of various GC-related conditions (e.g., peptic ulcer, gastric ulcer, gastritis) and screening (H. pylori testing and endoscopy) from inpatient hospital and physician/outpatient services claims. Results: Data from 34,730 subjects were analyzed. The majority of Asian American/Pacific Islanders (AAPIs), 65.1%, were foreign-born, while majority of Non-Hispanic Whites (NHW), Hispanics and Blacks were US-born (88.7%, 51.3%, and 96.9%, respectively). NHWs were oldest at diagnosis (74.7 y.); Hispanic and Black cases were the youngest (72.4 and 72.9 y., respectively). For NHWs, the most frequently diagnosed GC site was the cardia (36.1%), while for AAPIs, Hispanics and Blacks, the most diagnosed sites were non-cardia (>80%, P < 0.001). Over 55% of NHW, Hispanic and Black cases were diagnosed at regional or distant stage, while 55% of AAPIs were diagnosed at local or regional stage. Over 57% of all cases had a history of GC-related conditions (AAPIs were highest at 64.1%). However, only 11.2% of total cases showed evidence of H. pylori testing. H. pylori testing was more frequent for foreign-born than US-born (2-fold increase in proportions) and AAPIs exhibited the highest proportion of H. pylori testing (22.6% among those with a GC-related condition). Conclusions: Screening for H. pylori was low for all GC cases, despite race/ethnic groups exhibiting conditions for which H. pylori testing is recommended. AAPI GC cases had the highest frequency of H. pylori testing with tumors staged locally or regionally; increased testing could lead to earlier stage of tumor at diagnosis. Future studies should investigate why screening rates are low in patients with GC-related conditions.
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Ar'Rajab A, Harris RB, Khair-el-Din TA, Sentementes JT, Lu C, Dawidson IJ. Immunosuppressive Effect of 2′-Deoxycoformycin (Pentostatin®) for Rat Islet Allotransplantation. Cell Transplant 2017; 4:315-21. [PMID: 7640871 DOI: 10.1177/096368979500400310] [Citation(s) in RCA: 2] [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: 11/16/2022] Open
Abstract
Adenosine deaminase (ADA) is an important enzyme for proper function of lymphocytes and congenital absence of ADA results in a form of severe combined immunodeficiency syndrome. 2′-Deoxycoformycin (Pentostatin®, DCF) irreversibly inhibits ADA and therefore has been suggested as an immunosuppressive drug. The present study evaluated the immunosuppressive effect of DCF for islet allotransplantation in rats. Isolated islets (1,500 islets) from Lewis rats were transplanted into the kidney subcapsular space of streptozotocin-induced diabetic Wistar-Furth rats. DCF was administered IP either as a single injection at 1 mg/kg/wk, 1 mg/kg twice weekly, 5 mg/kg/twice weekly or 1 mg/kg/day, or as a continuous infusion at 0.8 or 1 mg/kg/day. Daily administration of DCF at 0.8 mg/kg in both methods, single daily injection or continuous infusion, resulted in a lymphopenia and a decrease in concanavalin A stimulation of splenic lymphocytes. However, DCF (in all doses) was not effective in preventing islet allograft rejection as evaluated by measuring the duration of normoglycemia following islet transplantation and by microscopic examination of the islet grafts. In fact, the duration of normoglycemia following islet transplantation was 7.5 ± 0.9 and 9.0 ± 1.0 days in rats receiving DCF in single daily injection or continuous infusion, respectively. This was not significantly different from control nontreated transplanted rats (8.5 ± 0.7 days). Increasing the dose of DCF to 1 mg/kg, administered by continuous infusion, resulted in 100% mortality. For comparison, cyclosporine A (20 mg/kg, IP daily injection for 14 days) prolonged islet allograft survival to 27.3 ± 1.5 days (p < 0.001). It is concluded that inhibition of ADA by DCF, despite its marked lymphotoxic effect, does not prevent rejection of islet allograft.
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Affiliation(s)
- A Ar'Rajab
- Department of Surgery, University of Texas Southwestern Medical Center, Dallas 75235-9031, USA
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Zhou J, Shi MX, Mitchell TD, Smagin GN, Thomas SR, Ryan DH, Harris RB. Changes in Rat Adipocyte and Liver Glucose Metabolism Following Repeated Restraint Stress. Exp Biol Med (Maywood) 2016; 226:312-9. [PMID: 11368423 DOI: 10.1177/153537020122600408] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [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: 11/15/2022] Open
Abstract
Rats exposed to repeated restraint weigh less than controls even 8 weeks after stress. Stress-induced weight loss is lean tissue, but the post-stress difference in weight between control and restrained rats is lean and fat mass. Whole-body glucose clearance is enhanced 1 day after stress, but adipocyte glucose utilization is inhibited and muscle glucose transport is unchanged. The studies described here demonstrated that glucose transport was increased in both restrained and pair-fed rats, but that glycogen synthesis was increased only in restrained rats, which may account for the improved whole-body glucose clearance. Adipocyte glucose transport was inhibited and adipose plasma membrane β-adrenergic receptor number was increased 1 day post-stress in restrained rats when weight loss was lean tissue, but were not different from control rats 5 days post-stress, when both fat and lean tissue were reduced. Thus, repeated restraint induces reversible changes in adipocyte metabolism that may represent a transition from the catabolic state of stress to a new energetic equilibrium in rats that maintain a reduced body weight for an extended period of time.
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Affiliation(s)
- J Zhou
- Pennington Biomedical Research Center, Louisiana State University, Baton Rouge 70808, USA.
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Arthofer W, Banbury BL, Carneiro M, Cicconardi F, Duda TF, Harris RB, Kang DS, Leaché AD, Nolte V, Nourisson C, Palmieri N, Schlick-Steiner BC, Schlötterer C, Sequeira F, Sim C, Steiner FM, Vallinoto M, Weese DA. Genomic Resources Notes Accepted 1 August 2014-30 September 2014. Mol Ecol Resour 2014; 15:228-9. [DOI: 10.1111/1755-0998.12340] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
| | - Wolfgang Arthofer
- Molecular Ecology Group; Institute of Ecology; University of Innsbruck; Technikerstraße 25 6020 Innsbruck Austria
| | - B. L. Banbury
- Department of Biology & Burke Museum of Natural History and Culture; University of Washington; Seattle WA 98195-1800 USA
| | - Miguel Carneiro
- CIBIO-InBIO; Centro de Investigação em Biodiversidade e Recursos Genéticos; Campus Agrário de Vairão; Universidade do Porto; 4485-661 Vairão Portugal
| | - Francesco Cicconardi
- Molecular Ecology Group; Institute of Ecology; University of Innsbruck; Technikerstraße 25 6020 Innsbruck Austria
| | - Thomas F. Duda
- Department of Ecological and Evolutionary Biology and Museum of Zoology; University of Michigan; Ann Arbor MI 48108 USA
- Smithsonian Tropical Research Institute; Balboa Ancón Republic of Panama 0843-03092
| | - R. B. Harris
- Department of Biology & Burke Museum of Natural History and Culture; University of Washington; Seattle WA 98195-1800 USA
| | - David S. Kang
- Department of Biology; Baylor University; Waco TX 76798 USA
| | - A. D. Leaché
- Department of Biology & Burke Museum of Natural History and Culture; University of Washington; Seattle WA 98195-1800 USA
| | - Viola Nolte
- Institut fur Populationsgenetik; Vetmeduni Vienna; Veterinärplatz 1 1210 Vienna Austria
| | - Coralie Nourisson
- CIBIO-InBIO; Centro de Investigação em Biodiversidade e Recursos Genéticos; Campus Agrário de Vairão; Universidade do Porto; 4485-661 Vairão Portugal
| | - Nicola Palmieri
- Institut fur Populationsgenetik; Vetmeduni Vienna; Veterinärplatz 1 1210 Vienna Austria
| | - Birgit C. Schlick-Steiner
- Molecular Ecology Group; Institute of Ecology; University of Innsbruck; Technikerstraße 25 6020 Innsbruck Austria
| | - Christian Schlötterer
- Institut fur Populationsgenetik; Vetmeduni Vienna; Veterinärplatz 1 1210 Vienna Austria
| | - Fernando Sequeira
- CIBIO-InBIO; Centro de Investigação em Biodiversidade e Recursos Genéticos; Campus Agrário de Vairão; Universidade do Porto; 4485-661 Vairão Portugal
| | - Cheolho Sim
- Department of Biology; Baylor University; Waco TX 76798 USA
| | - Florian M. Steiner
- Molecular Ecology Group; Institute of Ecology; University of Innsbruck; Technikerstraße 25 6020 Innsbruck Austria
| | - Marcelo Vallinoto
- CIBIO-InBIO; Centro de Investigação em Biodiversidade e Recursos Genéticos; Campus Agrário de Vairão; Universidade do Porto; 4485-661 Vairão Portugal
- Institute of Coastal Studies (IECOS); Universidade Federal do Pará; Bragança Campus Bragança PA Brasil 68600-000
| | - David A. Weese
- Department of Ecological and Evolutionary Biology and Museum of Zoology; University of Michigan; Ann Arbor MI 48108 USA
- Department of Biological and Environmental Sciences; Georgia College and State University; Milledgeville GA 31061 USA
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Abalos AT, Eggers R, Hogan M, Nielson CM, Giuliano AR, Harris RB, Thompson PA. Design and validation of a multiplex specific primer-directed polymerase chain reaction assay for killer-cell immunoglobulin-like receptor genetic profiling. ACTA ACUST UNITED AC 2011; 77:143-8. [PMID: 21214526 DOI: 10.1111/j.1399-0039.2010.01588.x] [Citation(s) in RCA: 7] [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: 11/27/2022]
Abstract
Current methodologies for the analysis of the killer-cell immunoglobulin-like receptor (KIR) locus utilize specific primer-directed polymerase chain reaction (SSP-PCR), which require a wide range of DNA input, multiple reaction conditions, and up to 16 individual reactions. We have developed and validated a multiplex SSP-PCR method for the genetic analysis of the KIR locus. Design and optimization of four multiplex groups targeting 14 genes and their alleles on the KIR locus has been completed. Each multiplex group contains PCR products that differ in size by a minimum of 15 bp to allow sufficient fragment length resolution for size discrimination by gel electrophoresis. This assay allows for efficient genotyping of the KIR locus while requiring a minimum amount of DNA input, utilizing the simplicity of SSP-PCR.
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Affiliation(s)
- A T Abalos
- Mel and Enid Zuckerman College of Public Health, University of Arizona, Tucson, AZ, USA.
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Brown SR, Nuno T, Joshweseoma L, Begay RC, Goodluck C, Harris RB. Impact of a community-based breast cancer screening program on Hopi women. Prev Med 2011; 52:390-3. [PMID: 21371495 PMCID: PMC3113717 DOI: 10.1016/j.ypmed.2011.02.012] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/28/2010] [Revised: 02/16/2011] [Accepted: 02/21/2011] [Indexed: 10/18/2022]
Abstract
OBJECTIVE To examine changes in breast cancer knowledge, attitudes, beliefs and behaviors following implementation of a tribal run CDC Breast and Cervical Cancer Program (BCCP), we report 2006 survey results from Hopi women and contrast findings with 1993 survey data and BCCP reports. METHODS Community meetings, focus groups, and researchers jointly developed a culturally appropriate survey instrument. Hopi women randomly selected from Tribal enrollment lists were interviewed in-person by Hopi interviewers; 250 women ≥ age 18 participated (87% response) between June and December, 2006. RESULTS Among women 40+, 77.5% reported ever having had a mammogram and 68.9% reported having done so within the past 2years, an increase from 45.2% and 46% self-reported in 1993. Compared to 1993, more women in 2006 (88.1% vs. 59%) believed that a mammogram can detect cancer and more than 90% now believe that early detection of cancer can save lives. Women reported a preference (60%) for receiving health care at the Hopi BCCP. Survey results were validated using programmatic data which estimated 76.6% of Hopi women had received mammography screening. CONCLUSION Implementation of a tribal run BCCP has resulted in a substantial increase in mammography screening on the Hopi reservation.
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Affiliation(s)
- S R Brown
- Mel and Enid Zuckerman College of Public Health, University of Arizona, 1215 N. Martin, Room A 242, Tucson, AZ 85750, USA.
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Luikart G, Amish SJ, Winnie J, Beja-Pereira A, Godinho R, Allendorf FW, Harris RB. High connectivity among argali sheep from Afghanistan and adjacent countries: Inferences from neutral and candidate gene microsatellites. CONSERV GENET 2011. [DOI: 10.1007/s10592-011-0195-z] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Garland LL, Chow HS, Einspahr J, Harris RB, Buckmeier J, Tobar M, Rodney S, Hakim IA. Phase III trial of chemoprevention of lung carcinogenesis using green tea beverage and tea polyphenols (Polyphenon E). J Clin Oncol 2006. [DOI: 10.1200/jco.2006.24.18_suppl.1026] [Citation(s) in RCA: 0] [Impact Index Per Article: 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
1026 Background: Oxidative reactions have been implicated as important modulators of human health and the development of disease, including cancer. Studies have shown an increased oxidant burden in chronic obstructive pulmonary disease, a disease state in which there is increased risk of lung cancer. Our overall goal is to develop a safe, feasible clinical research approach using non-invasive methods of biomarker retrieval that will serve as a model for lung cancer chemoprevention studies. The primary study objective is to determine the effects of high green tea consumption (beverage and Polyphenon E [Mitsui-Norin Co., Ltd., Shizuoka, Japan]) on biomarkers of oxidative stress that are putative modulators of lung cancer risk, including 8-hydroxydeoxyguanosine (protein oxidation), F2-isoprostanes (lipid oxidation), nitric oxide and antioxidant enzymes. Secondary objectives are to measure modulation of lung carcinogenesis-related genes in exfoliated bronchoepithelial cells. Methods: We are conducting a 6-month randomized, controlled, double-blind trial of beverage green tea or Polyphenon E capsules or a control intervention (matching double placebo) in former smokers (FS) with a ≥30 pack year smoking history and an FEV1 ≤70%. Subjects are stratified by gender and inhaler use. Changes in oxidative damage are measured in exhaled breath condensate, blood and urine. Changes in gene expression of proliferative biomarkers (EGFR, PCNA, JUN, FOS, Ki-67) and apoptosis (bcl-2, caspase 3) are being assessed in induced sputum. Results: Recruitment and screening of subjects began 6/04. As of 12/05, 559 subjects have been phone screened for eligibility; of 99 eligible subjects, 54 were excluded by spirometry. 45 subjects have been enrolled and 25 have completed the study. No significant adverse events have been reported, including no liver toxicity. We have been able to extract RNA and measure gene expression in induced sputum. Conclusion: Six-month high tea consumption in FS with at least a moderate smoking history and FEV1 ≤70% is feasible and safe. Recruitment is continuing. Supported by U01-CA-101204. No significant financial relationships to disclose.
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Affiliation(s)
| | | | | | | | | | - M. Tobar
- Arizona Cancer Center, Tucson, AZ
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Clouser MC, Harris RB, Roe DJ. Reliability of Self Reported Sun Exposure Factors. Am J Epidemiol 2006. [DOI: 10.1093/aje/163.suppl_11.s91-b] [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: 11/13/2022] Open
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Harris RB, Tommasino M, Nielson CM, Hakim IA, Franceschi S, Giuliano AR. 084: Human Papillomavirus and Cutaneous Squamous Cell Carcinoma: A Case-Control Study. Am J Epidemiol 2005. [DOI: 10.1093/aje/161.supplement_1.s21c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
| | | | | | - I A Hakim
- University of Arizona, Tucson, AZ 85724
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Affiliation(s)
- J M Harris
- Department of Medicine, College of Medicine, Arizona Health Sciences Center, Tucson, AZ 85712, USA
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Abstract
Limonene has demonstrated efficacy in preclinical models of breast and colon cancers. The principal sources of d-limonene are the oils of orange, grapefruit, and lemon. The present case-control study was designed to determine the usual citrus consumption patterns of an older Southwestern population and to then evaluate how this citrus consumption varied with history of squamous cell carcinoma (SCC) of the skin. In this Arizona population, 64.3% and 74.5% of the respondents reported weekly consumption of citrus fruits and citrus juices, respectively. Orange juice (78.5%), orange (74.3%), and grapefruit (65.3%) were the predominant varieties of citrus consumed. Peel consumption was not uncommon, with 34.7% of all subjects reporting citrus peel use. We found no association between the overall consumption of citrus fruits [odds ratio (OR) = 0.99, 95% confidence interval (CI) = 0.73-1.32] or citrus juices (OR = 0.97, 95% CI = 0.71-1.31) and skin SCC. However, the most striking feature was the protection purported by citrus peel consumption (OR = 0.66, 95% CI = 0.45-0.95). Moreover, there was a dose-response relationship between higher citrus peel in the diet and degree of risk lowering. This is the first study to explore the relationship between citrus peel consumption and human cancers. Our results show that peel consumption, the major source of dietary d-limonene, is not uncommon and may have a potential protective effect in relation to skin SCC. Further studies with large sample sizes are needed to more completely evaluate the interrelationships between peel intake, bioavailability of d-limonene, and other lifestyle factors.
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Affiliation(s)
- I A Hakim
- Cancer Prevention and Control, Arizona Cancer Center, College of Medicine, University of Arizona, Tucson, AZ 85724, USA.
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Abstract
This report describes trends in the incidence of various nonmelanoma skin cancers in a region of high ultraviolet exposure. The Southeastern Arizona Skin Cancer Registry routinely identified cases of skin cancer between 1985 and 1996 through pathology logs and reports from dermatology offices and laboratories in 3 Arizona counties. The incidence rates for squamous cell carcinoma (SCC) and basal cell carcinoma (BCC) for non-Hispanic whites were 3 to 6 times higher than the incidence rates from more northern regions. The rates for non-Hispanic whites were approximately 11 times greater than rates for Hispanics. Furthermore, there was no constant increase in the incidence of nonmelanoma skin cancers. The incidence of SCC, in particular, demonstrated a plateau or even a modest decline between 1985 and 1996. Thus the incidence rates of both SCC and BCC in Arizona, although among the highest in the world, do not appear to be increasing as rapidly as predicted elsewhere.
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Affiliation(s)
- R B Harris
- Division of Cancer Prevention and Control, Arizona Cancer Center, University of Arizona, Tucson 85724, USA.
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Abstract
Obese, diabetic C57BL/Ks db/db mice that lack the long-form leptin receptor exhibit no decrease in body weight or food intake when treated with leptin. Here we compared responses to leptin in two strains of db/db mice: C57BL/6J mice that are hyperglycemic and hyperinsulinemic and C57BL/Ks that are hyperglycemic and normo- or hypoinsulinemic. Chronic intraperitoneal infusion of 10 microgram leptin/day partially reversed hyperglycemia in C57BL/6J male mice but exaggerated the diabetic state of female mice. Bolus intraperitoneal injections of 40 microgram leptin/day did not effect glucose in either strain of male db/db mice, whereas chronic intraperitoneal infusion of 20 microgram leptin/day significantly reduced fasting blood glucose in male mice from both strains, especially C57BL/6J mice. Food intake, body weight, rectal temperature, and body fat did not change. Chronic intraperitoneal infusion of 10 microgram leptin/day significantly reduced body fat in lean db/+ C57BL/6J but not in C57BL/Ks mice. Thus peripherally administered leptin is active in mice that have only short-form leptin receptors, and the response is dependent on the method of leptin administration and the background strain.
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Affiliation(s)
- R B Harris
- Departments of Neuroscience and Biostatistics, Pennington Biomedical Research Center, Baton Rouge, Louisiana 70808, USA.
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Abstract
Ectopic overexpression of agouti protein, an endogenous antagonist of melanocortin receptors' linked to the beta-actin promoter (BAPa) in mice, produces a phenotype of yellow coat color, Type II diabetes, obesity and increased somatic growth. Spontaneous overexpression of agouti increases stress-induced weight loss. In these experiments, other aspects of stress responsiveness were tested in 12-week-old male wild-type mice and BAPa mice. Two hours of restraint on three consecutive days produced greater increases in corticosterone and post-stress weight loss in BAPa than wild-type mice. In Experiment 2, anxiety-type behavior was measured immediately after 12 min of restraint. This mild stress did not produce many changes indicative of anxiety, but BAPa mice spent more time in the dark side of a light-dark box and less time in the open arms of an elevated plus maze than restrained wild-type mice. In a defensive withdrawal test, grooming was increased by restraint in all mice, but the duration of each event was substantially shorter in BAPa mice, possibly due to direct antagonism of the MC4-R by agouti protein. Thus, BAPa mice showed exaggerated endocrine and energetic responses to restraint stress with small differences in anxiety-type behavior compared with wild-type mice. These results are consistent with observations in other transgenic mice in which the melanocortin system is disrupted, but contrast with reports that acute blockade of central melanocortin receptors inhibits stress-induced hypophagia. Thus, the increased stress responsiveness in BAPa mice may be a developmental compensation for chronic inhibition of melanocortin receptors.
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Affiliation(s)
- R B Harris
- Pennington Biomedical Research Center, 6400 Perkins Road, 70808, Baton Rouge, LA, USA.
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Hakim IA, Hartz V, Harris RB, Balentine D, Weisgerber UM, Graver E, Whitacre R, Alberts D. Reproducibility and relative validity of a questionnaire to assess intake of black tea polyphenols in epidemiological studies. Cancer Epidemiol Biomarkers Prev 2001; 10:667-78. [PMID: 11401918] [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: 02/20/2023] Open
Abstract
Epidemiological studies suggest that tea drinking may reduce the risk of cardiovascular diseases and cancers. Although tea is an important source of antioxidant phytochemicals, variation in preparation techniques may translate to variation in antioxidant capacity. However, most large-scale epidemiological studies use regular food frequency questionnaires to estimate tea intake, and nationally available nutrient analysis databases do not include levels of black tea polyphenols. The Arizona Tea Questionnaire (ATQ) was designed as a tool for collecting more complete dietary tea consumption information, and a database was developed after analyzing 40 black tea samples (brewed, instant, and sun tea) for polyphenols. This study assesses the reliability and relative validity of the ATQ and polyphenol database. Relative validity of estimates of black tea consumption was tested by comparing the ATQ with the traditional Arizona Food Frequency Questionnaire and four days of food records. The ATQ was tested for reproducibility of estimates of black (hot and iced) tea consumption and levels of black tea polyphenol intake. Correlations between two measures of intake taken 2 months apart ranged from 0.72 for black hot tea to 0.86 for black sun tea. Mean intakes (range) of total flavonoids for black tea consumers were 80.8 (3.0-588.0) mg/day at the first ATQ and 102.4 (4.5-802.3) mg/day at the second ATQ (r = 0.83, P < 0.001). The ATQ provided highly reproducible estimates of both total tea consumption and individual tea polyphenol intake. This instrument may be a useful tool in studies of the associations between tea consumption, tea polyphenols intake, and risk for chronic disease.
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Affiliation(s)
- I A Hakim
- Arizona Cancer Center, Division of Cancer Prevention and Control, Tucson, Arizona 85724, USA.
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19
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Abstract
The varied effects of different classes of dietary fatty acids on carcinogenesis suggest that fatty acid composition is an important determining factor in tumor development. In the present study, we investigated the association between dietary n-3 and n-6 fatty acid intake and risk of squamous cell carcinoma of the skin (SCC). Data were taken from a population-based case-control study of skin SCC in Southeastern Arizona. Our data show a consistent tendency for a lower risk of SCC with higher intakes of n-3 fatty acids [p (for trend) = 0.055]. The adjusted odds ratios for increasing levels of n-3 fatty acids were 0.85 [95% confidence interval (CI) = 0.56-1.27] and 0.71 (95% CI = 0.49-1.00) compared with the lower level as the referent. For the ratio of n-3 to n-6 fatty acids, the odds ratios in successively higher levels were 0.88 (95% CI = 0.59-1.32) and 0.74 (95% CI = 0.51-1.05), suggesting a tendency toward decreased risk of SCC with increased intake of diets with high ratio of n-3 to n-6 fatty acid. More studies are clearly needed to elucidate the function of dietary fatty acids so that recommendations can be made to alter the human diet for cancer prevention, particularly in light of the increasing incidence of SCC of the skin.
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Affiliation(s)
- I A Hakim
- Arizona Cancer Center, College of Medicine, University of Arizona, Tucson 85724, USA.
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20
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Abstract
Much attention has focused on the effects of leptin as a central satiety agent. There is now a significant amount of evidence that leptin is active in the periphery. This review focuses on the ability of leptin to modify insulin sensitivity, tissue metabolism, stress responses, and reproductive function. Leptin's effect on several of these systems is mediated via the hypothalamic-pituitary axis. Therefore, although in vitro studies provide evidence for direct effects on specific tissues and metabolic pathways, it is essential to consider the interactions between leptin and other regulatory factors in vivo. Little is known about the regulation of peripheral receptor expression or the production of binding proteins. Both of these factors determine the bioactivity of circulating leptin and have the potential to induce a peripheral resistance to leptin, similar to the central "leptin resistance" observed in obese subjects. Future research will clarify which of the endocrine and metabolic actions of peripheral leptin are of physiological relevance and which should be considered a pharmacological manipulation.
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Affiliation(s)
- R B Harris
- Pennington Biomedical Research Center, Baton Rouge, Louisiana 70808, USA.
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21
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Abstract
Risk factors for non-melanoma skin cancer among populations with evidence of precursor damage are not well described. We examined and compared risk factors associated with the development of cutaneous basal-cell (BCC) or squamous-cell (SCC) carcinoma among a group of 918 adults with significant sun damage (> or = 10 clinically assessable actinic keratoses) but no prior history of skin cancer. These adults were participants in a 5-year skin chemoprevention trial between 1985 and 1992, who had been randomized to the placebo group and followed for occurrence of skin cancer. During the study, a total of 129 first SCC and 164 first BCC lesions were diagnosed. The overall BCC and SCC incidence rates for this group of men and women, mean age 61 years, were 4,106 and 3,198 per 100,000 person-years, respectively. Different constitutional and exposure factors were independently associated with BCC compared to SCC. Only increased age independently predicted BCC occurrence among this population. In contrast, older age along with male gender, natural red hair color and adult residence in Arizona for 10 or more years independently predicted SCC occurrence. The substantial incidence of skin cancer found among this population confirms the need for active dermatological monitoring among individuals with multiple visible actinic lesions.
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Affiliation(s)
- J A Foote
- Arizona Cancer Center, University of Arizona, Tucson, AZ, USA.
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22
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Abstract
We sought to determine whether an Internet-based continuing medical education (CME) program could improve physician confidence, knowledge, and clinical skills in managing pigmented skin lesions. The CME program provided an interactive, customized learning experience and incorporated well-established guidelines for recognizing malignant melanoma. During a 6-week evaluation period, 354 physicians completed the on-line program as well as a pretest and an identical posttest. Use of the CME program was associated with significant improvements in physician confidence, correct answers to a 10-question knowledge test (52% vs 85% correct), and correct answers to a 15-question clinical skills test (81% vs 90% correct). We found that the overall improvement in clinical skills was due to a marked increase in specificity and a small decrease in sensitivity for evaluating pigmented lesions. User satisfaction was extremely high. This popular and easily distributed online CME program increased physicians' confidence and knowledge of skin cancer. Remaining challenges include improving the program to increase physician sensitivity for evaluating pigmented lesions while preserving the enhanced specificity.
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Affiliation(s)
- J M Harris
- Department of Medicine, College of Medicine, Arizona Health Sciences Center, Tucson, AZ, USA.
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23
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Abstract
Surgical removal of body fat (partial lipectomy) is a means of directly reducing fat such that metabolic and behavioral responses can be readily attributed to the lipid deficit. If total body fat is regulated, then lipectomy should trigger compensatory increases in nonexcised white adipose tissue (WAT) mass and/or regrowth at excision sites. Many species, including laboratory rats and mice, show lipectomy-induced compensatory recovery of body fat. Those animals exhibiting naturally occurring annual adiposity cycles, such as ground squirrels and hamsters, do so most impressively reaching seasonally appropriate body fat levels indistinguishable from controls. Reparation of the lipid deficit occurs without an increase in food intake, and generally through enlargement of non-excised WAT mass, rather than regrowth of excised WAT. A body fat regulatory system involving humoral and sensory neural inputs to the brain as well as sympathetic neural outputs from brain to adipose tissue is presented. Collectively, the lipectomy model appears useful for testing mechanisms controlling adiposity, or individual depot growth, and offers insight into how lipid stores fluctuate naturally.
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Affiliation(s)
- M M Mauer
- Department of Biology and the Neurobiology and Behavior Program, Georgia State University, University Plaza, Atlanta, GA 30303-3083, USA
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24
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Abstract
Fatty (fa/fa) rats accumulate more adipose mass than their littermates soon after birth, but they first appear obese during the fourth week of life. We analyzed the effects of fa genotype on growth of pups housed with their dams through 4 wk of age. The fa genotype effects on daily gain were undetectable from 7 to 22 days of age but became highly significant (P = 10(-18)) at 23 days of age. When litters were reduced to 4 pups, fa genotype effects on daily gain also became detectable at 23 days of age. The fa genotype effects on daily gain, stomach contents weight, liver weight, and plasma insulin of rats killed from 20 to 24 days of age displayed a marked genotype by age interaction, becoming highly significant at 23 days of age. These changes occur without the environmental changes induced by separating pups from their dams. These observations suggest that a developmental switch triggers hyperphagia and rapidly increases growth rate of fatty rats after 22 days of age.
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Affiliation(s)
- G E Truett
- Pennington Biomedical Research Center, Baton Rouge, Louisiana 70808, USA.
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25
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Guo Y, Harris RB, Rosson D, Boorman D, O'Brien TG. Functional analysis of human ornithine decarboxylase alleles. Cancer Res 2000; 60:6314-7. [PMID: 11103791] [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: 02/18/2023]
Abstract
It has been known for > 10 years that there are two alleles of the human ornithine decarboxylase (ODC) gene, defined by a polymorphic PstI RFLP in intron 1. We have sequenced a large portion of each of the two alleles, including some of the 5' promoter region, exon 1, intron 1, and exon 2, and determined that a single nucleotide polymorphism at base +317 (relative to transcription start site) is responsible for the presence or absence of the PstI restriction site. We have developed two genotyping assays, a PCR-RFLP assay and a high-throughput TaqMan-based method, and determined the ODC genotype distribution in >900 North American DNA samples. On the basis of its location between two closely spaced Myc/Max binding sites (E-boxes), we speculated that the single nucleotide polymorphism at base +317 could have functional significance. Results of transfection assays with allele-specific reporter constructs support this hypothesis. The promoter/regulatory region derived from the minor ODC allele (A allele) was more effective in driving luciferase expression in these assays than the identical region from the major allele (G allele). Our results suggest that individuals homozygous for the A allele may be capable of greater ODC expression after environmental exposures, especially those that up-regulate c-MYC expression.
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Affiliation(s)
- Y Guo
- Lankenau Institute for Medical Research, Wynnewood, Pennsylvania 19096, USA
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Abstract
OBJECTIVE The purpose of this study was to compare the diet of healthy, free-living senior volunteers to the dietary reference intakes (DRIs) and Food Guide Pyramid recommendations. METHODS This study was a cross-sectional assessment of dietary habits, as measured using a standardized food frequency questionnaire, among 1,740 healthy Southwestern U.S. adults, aged 51 to 85 years. Assessment of independently-living volunteers to chemoprevention trials provides an efficient mechanism to profile typical dietary habits among the older adult population. RESULTS Daily estimated macronutrient intakes exceeded recommended proportions of protein and fat. In contrast, more than 60% of this senior population reported dietary vitamin D, vitamin E, folate and calcium intakes below estimated average requirements (EAR). Based on the Food Guide Pyramid recommendations, fewer than 10% of the older adults consumed the recommended daily dairy and grain servings. More females than males consumed recommended vegetable (49% versus 40%) and fruit (53% versus 48%) servings (p < 0.05). More males consumed recommended grain (11% versus 7%) and protein (78% versus 73%) servings (p < 0.05) than females. CONCLUSIONS Mean micronutrient intakes compared well with DRIs, although fewer than one-half of these older adults consumed recommended levels for vitamin D, vitamin E, folate, and calcium or daily food servings of dairy, grains, vegetables or fruits. Since the beneficial aspects of foods are not limited to essential nutrients, nutrition recommendations to older adults may be improved by emphasizing daily servings of nutrient-dense choices within the Food Pyramid.
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Affiliation(s)
- J A Foote
- Arizona Cancer Center,The University of Arizona, Tucson, USA.
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27
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Abstract
Urocortin (UCN) has 45% sequence homology with corticotropin releasing factor (CRF) and binds to CRF receptors. We used reverse-transcriptase-polymerase chain reaction to demonstrate the presence of UCN RNA in various brain regions and in peripheral tissues. Ribonuclease protection assay (RPA) using sense and antisense riboprobes demonstrated the presence of a naturally occurring antisense UCN RNA transcript in a number of tissues. Northern blot indicated that the antisense transcript was the same size as sense UCN. RPA, using probes that covered bases 1 to 560 of 579 bp sequence of rat UCN, indicated that the antisense sequence was complementary to sense UCN but did not contain an open reading frame. Sense and antisense UCN RNA were co-expressed in all tissues that contained levels of either transcript detectable by RPA. Sense RNA expression was greater than antisense in the midbrain, the two transcripts were expressed equally in the hypothalamus and antisense was expressed at higher levels than sense in the liver, heart, and skeletal muscle. Antisense RNA expression was stress responsive, suggesting that it may play a role in regulating transcription or translation of UCN mRNA.
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Affiliation(s)
- M Shi
- Pennington Biomedical Research Center, Baton Rouge, LA, USA
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28
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Majluf-Cruz A, Manns JM, Uknis AB, Yang X, Colman RW, Harris RB, Frazier W, Lawler J, DeLa Cadena RA. Residues F16-G33 and A784-N823 within platelet thrombospondin-1 play a major role in binding human neutrophils: evaluation by two novel binding assays. J Lab Clin Med 2000; 136:292-302. [PMID: 11039850 DOI: 10.1067/mlc.2000.109407] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The thrombospondin-1 (TSP1) structural requirements within its heparin-binding domain (HBD)(30 kd) or within the other domains of the molecule (450 kd) that interact with neutrophils (PMNs) have not been delineated. Synthetic peptides based on the HBD, a TSP1 proteolytic fragment lacking the HBD, a large C-terminal domain of TSP1 (210 kd), a TSP1 recombinant fragment (rTSP1(784-932)), and a monoclonal antibody directed against the TSP1 type 3 repeats (mAb D4.6) were utilized to map such structural requirements on TSP1. Synthetic peptides containing a heparin-binding motif and encompassing residues F16-G33 or A74-S95 of TSP1 competed quantitatively with iodine 125-labeled TSP1 for binding to heparinagarose beads. However, only F16-G33 was a competitor of TSP1 binding to PMNs, suggesting that the sequence F16-G33 within the HBD plays a role in PMN binding. The interaction site within the 450-kd fragment was further narrowed. A TSP1 -derived proteolytic fragment (210 kd), a recombinant TSP1 fragment (rTSP1(784-932)), and a type 3 repeat anti-TSP1 monoclonal antibody (mAb D4.6) competed for the binding of 125I-labeled TSP1 to PMNs. The N-terminal of rTSP1(784-932) and C-terminal sequence analysis of TSP1-210 kd delineated the structural requirements for the second binding region for PMNs-namely, residues A784-N823.
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Affiliation(s)
- A Majluf-Cruz
- Sol Sherry Thrombosis Research Center, Department of Physiology, Temple University School of Medicine, Philadelphia, USA
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29
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Hakim IA, Harris RB, Weisgerber UM. Tea intake and squamous cell carcinoma of the skin: influence of type of tea beverages. Cancer Epidemiol Biomarkers Prev 2000; 9:727-31. [PMID: 10919744] [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: 02/17/2023] Open
Abstract
Differences in tea drinking habits are likely to vary by populations and could contribute to the inconsistencies found between studies comparing tea consumption and cancer risk. A population-based case-control study was used to evaluate how usual tea consumption patterns of an older population (n = 450) varied with history of squamous cell carcinoma (SCC) of the skin. A detailed tea questionnaire was developed to assess specific tea preparation methods and patterns of drinking. In this southwestern United States population, black tea was the predominant variety of tea consumed. We found no association between the broad definition of any tea consumption and skin SCC. However, the adjusted odds ratios (ORs) for hot and iced black tea intake were 0.63 [95% confidence interval (CI), 0.36-1.10] and 1.02 (95% CI, 0.64-1.63), respectively. Controls were more likely to report usually drinking strong hot tea (OR, 0.74; 95% CI, 0.53-1.03) with increased brewing time (P for trend = 0.03). Adjusting for brewing time, the association between skin SCC and hot black tea consumption suggests a significantly lower risk in consumers of hot tea compared to nonconsumers (OR, 0.33; 95% CI, 0.12-0.87). This is one of the first studies to explore the relation between different types of tea consumption and occurrence of human cancers. Our results show that tea concentration (strength), brewing time, and beverage temperature have major influences on the potential protective effects of hot black tea in relation to skin SCC. Further studies with increased sample sizes are needed to evaluate the interrelationships between preparation techniques, tea type, and other life-style factors.
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Affiliation(s)
- I A Hakim
- Cancer Prevention and Control, Arizona Cancer Center, College of Medicine, University of Arizona, Tucson 85724, USA.
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30
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Harris RB. Domestic violence. N Engl J Med 2000; 342:1452. [PMID: 10809618] [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: 02/16/2023]
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31
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Shenoy S, Harris RB, Sobel M. Development of heparin antagonists with focused biological activity. Curr Pharm Des 1999; 5:965-86. [PMID: 10607857] [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: 02/14/2023]
Abstract
Heparin, a complex glycosaminoglycan, has long been used to temporarily render the blood incoagulable during extracorporeal circulation, cardiovascular surgery, and other arterial interventions. But bleeding complications are especially common when the arterial tree is violated, occurring in as many as 10-15% of cases. For cardiovascular surgery and many related interventions, protamine has long been the standard antagonist when acute and complete neutralization of heparin s anticoagulant effect is necessary. Protamine s efficacy is related in part to its total net cationic charge, but unfortunately so is its toxicity. For these reasons, there is renewed interest in developing heparin antagonists which will replace the use of protamine. At Commonwealth Biotechnologies, Inc., we have used a rationale design approach for the preparation of a family of low molecular weight helix peptides which bind heparin with high affinity. For each of the new compounds, we have assessed their ability to bind heparin using isothermal titration calorimetry and circular dichroism spectrometry and have examined potential complexes formed with the anticoagulant pentasaccharide unit of heparin using molecular modeling techniques. The biological potencies of these compounds were assessed in ex vivo experiments where their ability to compete with antithrombin for binding heparin was determined. The best of the compounds, designated HepArrestTM, is highly effective in reversing heparin-mediated and HepArrest is a safer drug than protamine because of reduced adverse hemodynamic side effects compared with those associated with protamine. HepArrest binds low molecular weight heparins and causes reversal of anticoagulation by low molecular weight heparins, as determined by activated partial thromboplastin time, thrombin time, or factor Xa neutralization assays. These highly promising preclinical results indicate that HepArrest is a novel heparin neutralizing agent that may well fill a substantial unmet need for vascular surgeons and cardiac anesthesiologists who perform coronary artery bypass grafts and several other major vascular surgeries, as well as for cardiologists and interventional radiologists.
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Affiliation(s)
- S Shenoy
- Commonwealth Biotechnologies, Inc., 601 Biotech Dr., Richmond, VA 23235, USA
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32
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Bramlett SB, Zhou J, Harris RB, Hendry SL, Witt TL, Zachwieja JJ. Does beta(3)-adrenoreceptor blockade attenuate acute exercise-induced reductions in leptin mRNA? J Appl Physiol (1985) 1999; 87:1678-83. [PMID: 10562609 DOI: 10.1152/jappl.1999.87.5.1678] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [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: 11/22/2022] Open
Abstract
We investigated the effect of a single bout of exercise on leptin mRNA levels in rat white adipose tissue. Male Sprague-Dawley rats were randomly assigned to an exercise or control group. Acute exercise was performed on a rodent treadmill and was carried out to exhaustion, lasting an average of 85.5 +/- 1.5 min. At the end of exercise, soleus muscle and liver glycogen were reduced by 88% (P < 0.001). Acutely exercised animals had lower (P < 0.05) leptin mRNA levels in retroperitoneal but not epididymal fat, and this was independent of fat pad weight. To test the hypothesis that beta(3)-adrenergic-receptor stimulation was involved in the downregulation of leptin mRNA in retroperitoneal fat, a second experiment was performed in which rats were randomized into one of four groups: control, control + beta(3)-antagonist, exercise, and exercise + beta(3)-antagonist. A highly selective beta(3)-antagonist (SR-59230A) or vehicle was given by gavage 30 min before exercise or control experiment. Exercise consisted of 55 min of treadmill running, sufficient to reduce liver and muscle glycogen by 70 and 80%, respectively (both P < 0.0001). Again, acute exercise reduced leptin mRNA in retroperitoneal fat (exercise vs. control; P < 0.05), but beta(3)-antagonism blocked this effect (exercise + beta(3)-antagonist vs. control + beta(3)-antagonist; P = 0.42). Unexpectedly, exercise increased serum leptin. This would be consistent with the idea that there are releasable, preformed pools of leptin within adipocytes. We conclude that beta(3)-receptor stimulation is a mechanism by which acute exercise downregulates retroperitoneal adipose tissue leptin mRNA in vivo.
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Affiliation(s)
- S B Bramlett
- Exercise and Nutrition Program, Pennington Biomedical Research Center, Louisiana State University, Baton Rouge, Louisiana 70808, USA
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33
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Youngblood BD, Smagin GN, Elkins PD, Ryan DH, Harris RB. The effects of paradoxical sleep deprivation and valine on spatial learning and brain 5-HT metabolism. Physiol Behav 1999; 67:643-9. [PMID: 10604833 DOI: 10.1016/s0031-9384(99)00120-1] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.7] [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: 11/21/2022]
Abstract
We have previously reported that rapid eye movement sleep deprivation (REMSD), induced by the flower pot technique, causes a deficit in reference spatial memory and increases rates of serotonin (5-HT) metabolism in the brain. In this study we used increased concentrations of dietary valine to inhibit tryptophan (TRP) transport across the blood-brain barrier in an attempt to modify the REMSD-induced increase of 5-HT metabolism. Rats were fed either a control diet or the same diet supplemented to 2% by weight valine, and were allocated to one of three experimental groups: cage control (CC), stress tank control (TC), or REMSD. Reference and working spatial memory of all rats was tested in a Morris water maze on Days 2, 3, and 4. REMSD produced a significant decrement in reference memory on Days 2 and 4, independent of dietary condition. The valine diet had a detrimental effect on the reference memory of TC rats on Day 2 but not Day 4. Measurements made on Day 4 indicated that the valine diet decreased brain TRP only in the CC rats. In contrast, the valine diet did not prevent increases in brain TRP or 5-HT metabolism in REMSD rats, and increased hypothalamic and brain stem TRP concentrations and the hippocampal 5-HIAA/5-HT ratio in TC rats. These results indicate that dietary valine does not prevent REMSD-induced changes in spatial memory or serotonin metabolism, although it does reduce brain TRP in nonstressed rats.
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Affiliation(s)
- B D Youngblood
- Pennington Biomedical Research Center, Baton Rouge, LA 70808, USA
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34
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Zhou J, Yan X, Ryan DH, Harris RB. Sustained effects of repeated restraint stress on muscle and adipocyte metabolism in high-fat-fed rats. Am J Physiol 1999; 277:R757-66. [PMID: 10484493 DOI: 10.1152/ajpregu.1999.277.3.r757] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Repeated restraint stress 3 h/day for 3 days in rats causes a temporary hypophagia but a sustained weight loss. We investigated whether poststress changes in peripheral tissue metabolism contributed to these responses. One day after the last restraint, insulin sensitivity, measured by oral glucose tolerance test, was improved in restrained rats. Restraint and pair-fed rats weighed less than controls, but body fat content was the same in all groups. Muscle glucose uptake, measured in vitro, was not changed by treatment, whereas in vitro adipocyte glucose uptake was substantially inhibited only in restrained rats. Adipocytes from restrained rats had elevated rates of fatty acid oxidation but not fatty acid esterification, indicating a shift in energy supply from glucose to fatty acids. Five days after the last restraint, the reduced weight of restrained and pair-fed rats resulted from loss of both lean and fat tissue. These results demonstrate that restraint caused sustained, tissue-specific changes in metabolism that may contribute to changes in body composition and body weight of the rats.
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Affiliation(s)
- J Zhou
- Department of Veterinary Physiology, Pharmacology, and Toxicology, Louisiana State University, Baton Rouge, Louisiana 70808, USA.
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35
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Zhou Y, Cheshire A, Howell LA, Ryan DH, Harris RB. Neuroautoantibody immunoreactivity in relation to aging and stress in apolipoprotein E-deficient mice. Brain Res Bull 1999; 49:173-9. [PMID: 10435780 DOI: 10.1016/s0361-9230(99)00052-0] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [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: 11/16/2022]
Abstract
Progressive disruption of both the neuroendocrine and immune systems has been correlated with age-associated pathogenesis in patients with Alzheimer's disease and in mice lacking apolipoprotein E (ApoE). In this study, we examined neuroautoimmune and neuroendocrine activities in relation to aging and stress in ApoE-deficient mice. An elevated level of autoantibodies against brain antigens was found in sera from ApoE-deficient mice compared to that of wild-type mice as early as 7-8 weeks of age. However, there was no significant difference between the two genotypes at this age in the effect of stress on serum corticosterone or autoantibody titers. Higher titers of autoantibodies were observed in approximately 12-week-old ApoE-deficient mice, especially in those exposed to chronic stress. Based on Western analysis, sera from ApoE-deficient mice showed a strong immunoreactivity with approximately 78 kDa and approximately 40 kDa brain abundant polypeptides, approximately 58 kDa non-brain tissue abundant antigen, and others of approximately, 80-82 kDa in both the brain and non-brain tissues. Immunofluorescence confocal microscopy showed that the major cellular components recognized by the autoimmune sera from ApoE-deficient mice were associated with neuronal cell nuclei and fiber-like structures in different regions of the brain, including the frontal cortex, lateral cortex and hippocampus. These results suggest that neuroautoimmunity associated with the aging process and exposure to chronic stress may be involved in early development of neurodegeneration in mice with ApoE-deficiency.
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Affiliation(s)
- Y Zhou
- Pennington Biomedical Research Center, Louisiana State University, Baton Rouge, USA.
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36
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Abstract
The aim of this study was to determine whether a brief Internet-based education programme could improve physicians' abilities to manage pigmented skin lesions. A pre-test-post-test assessment was used of subjects' knowledge of skin cancer, confidence in their management abilities and actual ability to recommend appropriate treatment for 20 hypothetical patients with pigmented skin lesions. The setting was the general medicine service of an academic medical centre. Seventeen volunteer medical students, house officers and faculty members took part in the study. Following the pre-test, subjects completed a 1-hour computer-based educational programme, distributed via the Internet, presenting a guideline for recognizing and managing potentially malignant pigmented skin lesions. The guideline was based on the ABCD rule and the Glasgow seven-point checklist. The educational programme had a positive effect on the subjects' overall skin cancer knowledge and had significantly positive effects on their confidence and ability to apply the management guideline. Based on the guideline criteria, the subjects made the correct management decision on the clinical scenarios 63.2% of the time before the programme and 74.1% of the time after the programme (P = 0.002). We were able to teach melanoma management guidelines to physicians and medical students using a brief, interactive computer programme distributed via the Internet. Such an approach is more cost-effective than classroom teaching and could be used to improve the clinical skills of practising physicians to recognize and manage early melanomas. This approach to distributed learning could also be used to teach other clinical guidelines to physicians.
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Affiliation(s)
- J M Harris
- Department of Medicine, College of Medicine, Arizona Health Sciences Center, Tucson, USA
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37
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Abstract
We previously reported that rats exposed to repeated restraint (3 h/day for 3 days) experience temporary hypophagia and a sustained reduction in body weight compared with nonrestrained controls. Studies described here determined the involvement of central corticotropin-releasing factor (CRF) receptors in the initiation of this chronic response to acute stress. In experiment 1, Sprague-Dawley rats were fitted with cannulas in the lateral ventricle and infused with 50 micrograms of alphahCRF-(9-41) or saline immediately before restraint on each of the 3 days of restraint. The receptor antagonist inhibited hypophagia and weight loss on day 1 of restraint but not on days 2 and 3. In experiment 2, 10 micrograms of alphahCRF-(9-41) or saline were infused into the third ventricle immediately before each restraint. The receptor antagonist totally blocked stress-induced hypophagia and weight loss. These results demonstrate that CRF receptors located in or near the hypothalamus mediate the acute responses to stress that lead to a permanent change in the hormonal or metabolic processes that determine body weight and body composition.
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Affiliation(s)
- G N Smagin
- Departments of Neuroscience and Biostatistics, Pennington Biomedical Research Center, Baton Rouge, Louisiana 70808, USA
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38
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Abstract
Inhibition of fatty acid oxidation stimulates feeding behavior in rats. To determine whether a decrease in hepatic fatty acid oxidation triggers this behavioral response, we compared the effects of different doses of methyl palmoxirate (MP), an inhibitor of fatty acid oxidation, on food intake with those on in vivo and in vitro liver and muscle metabolism. Administration of 1 mg/kg MP selectively decreased hepatic fatty acid oxidation but did not stimulate food intake. In contrast, feeding behavior increased in rats given 5 or 10 mg/kg MP, which inhibited hepatic fatty acid oxidation to the same extent as did the low dose but in addition suppressed fatty acid oxidation in muscle and produced a marked depletion of liver glycogen. Dose-related increases in food intake tracked dose-related reductions in liver ATP content, ATP-to-ADP ratio, and phosphorylation potential. The findings suggest that a decrease in hepatic fatty acid oxidation can stimulate feeding behavior by reducing hepatic energy production.
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Affiliation(s)
- M I Friedman
- Monell Chemical Senses Center, Philadelphia, Pennsylvania 19104, USA.
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39
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Abstract
Genetically obese C57B1/6J-m db/db mice were parabiosed with either lean male db/+ or obese female ob/ob mice. Male db/db mice had lower serum leptin than females, and this was reflected in the amount of protein that crossed the parabiotic union into their partners. Eighteen days post operation, ob/ob partners of db/db mice had increased body temperature, lost 50% body weight and 60% body fat, but maintained carcass protein. The db/+ partners of db/db mice had a normal gut content and (by implication) food intake, did not raise their body temperature, but lost significant amounts of both lean and fat tissue during 25 days of parabiosis. The differences between the db/+ and ob/ob partners of db/db mice may be caused by leptin inhibiting growth of male mice, but not of female mice that are on a slower growth curve, or by the excess lipid in ob/ob mice sparing body protein. The db/db partners of ob/ob mice lost a small amount of body fat, but carcass protein was increased by 30%, compared with their controls. These results imply that leptin stimulated release of a circulating growth factor, possibly through activation of the long-form leptin receptor, in ob/ob partners of db/db mice.
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Affiliation(s)
- R B Harris
- Pennington Biomedical Research Center, Baton Rouge, Louisiana 70808, USA.
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40
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Howell LA, Harris RB, Clarke C, Youngblood BD, Ryan DH, Gilbertson TA. The effects of restraint stress on intake of preferred and nonpreferred solutions in rodents. Physiol Behav 1999; 65:697-704. [PMID: 10073470 DOI: 10.1016/s0031-9384(98)00223-6] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [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: 10/17/2022]
Abstract
In these experiments we determined whether stress influenced intake of different flavored test solutions or only those that were preferred. In a series of studies, rats or hamsters were exposed to acute (1 h) or repeated (3 h/day for 3 days) restraint stress immediately followed by access to one of four tastants (saccharin, salt, citric acid, or quinine solutions) paired with water in a 24-h preference test. As rats prefer salt and hamsters do not, both species were used to test the effects of stress on preferred vs. nonpreferred solutions using the same stimulus. Acute restraint inhibited intake of saccharin in rats but had no effect on preference, indicating that suppression of intake was not due to changes in hedonic response. Restraint had no effect on saccharin intake of hamsters but significantly increased salt intake. However, as the preference ratio remained low for the solution (0.26), the stress-induced increase in salt intake was probably associated with a disturbance of sodium and fluid balance rather than a change in sensory perception. This was supported by stress having no effect on intake of nonpreferred solutions in rats or hamsters. Repeated restraint had no effect on salt or saccharin intake of rats when test solutions were presented after stress, but rats showed no preference for saccharin in a subsequent study in which the solution was associated with onset of stress. These results indicate that stress has specific effects on saccharin and salt intake that are not limited to preferred solutions.
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Affiliation(s)
- L A Howell
- Pennington Biomedical Research Center, Baton Rouge, LA 70808, USA
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41
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Harris RB, Zhou J, Youngblood BD, Rybkin II, Smagin GN, Ryan DH. Effect of repeated stress on body weight and body composition of rats fed low- and high-fat diets. Am J Physiol 1998; 275:R1928-38. [PMID: 9843882 DOI: 10.1152/ajpregu.1998.275.6.r1928] [Citation(s) in RCA: 79] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Exposure to the moderate stressor of 3-h restraint for 3 consecutive days causes a temporary drop in food intake but a permanent reduction in body weight in adult rats. Young rats did not show the same response. Food intake of adult rats exposed to repeated restraint was significantly lower than that of controls for 4 days after the end of stress, and there was no rebound hyperphagia. Body weight remained significantly lower for at least 40 days after stress. When the rats were fed a high-fat diet of 80% chow and 20% vegetable shortening (48% kcal fat, 16% protein), lean body mass accounted for all of the weight loss in stressed rats. When the experiment was repeated with a purified high-fat diet containing corn oil and coconut oil as the source of fat (41% kcal fat, 16% protein), weight loss consisted of both lean and fat tissue. There were no sustained changes in single time point measures of corticosterone, insulin, or leptin that could account for the reduced body weight in these rats.
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Affiliation(s)
- R B Harris
- Pennington Biomedical Research Center, Pharmacology, and Toxicology, Louisiana State University, Baton Rouge, Louisiana 70808, USA
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42
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Abstract
The experiments presented in this study were designed to assess corticotropin-releasing factor (CRF) receptor subtype mediation of CRF- and urocortin (UCN)-induced decrease in food intake. Male Sprague-Dawley rats were treated with antisense and sense oligonucleotides (ON) to CRF2 receptor mRNAs for 36 h and then received an intracerebroventricular (i.c.v.) injection of CRF, UCN (3 micrograms) or saline. Antisense treatment significantly attenuated CRF- and UCN-induced suppression in food intake and HPA activation. Administration of CRF1 receptor antagonist did not affect the decrease in food intake or activation of the HPA axis induced by i.c.v. infusion of 3 micrograms CRF. The data suggest that down-regulation of CRF2 receptors selectively attenuates CRF- and UCN-induced anorexia and hypothalamo-pituitary-adrenocortical activation in rats.
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Affiliation(s)
- G N Smagin
- Pennington Biomedical Research Center, Lousiana State University, Baton Rouge 70808, USA
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43
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Abstract
Experiments described here show that in vivo glucose uptake is impaired in mice given 30 micrograms leptin by intraperitoneal injection 2 hours before an oral glucose tolerance test (GTT). When mice were infused for 7 days with 10 micrograms/day leptin, the 4-fold increase in circulating leptin caused a transient hypophagia, a sustained weight loss and significantly inhibited insulin release in response to an oral GTT. Adipocytes from these mice were not insulin responsive whereas insulin-stimulated muscle and liver glycogen synthesis were increased. In contrast, leptin added to 2 hour in vitro incubations had an insulin-like effect on muscle glucose utilization and augmented insulin stimulation of adipocyte lipid synthesis. Thus, normal mice treated chronically with leptin develop tissue specific changes in insulin sensitivity and compensate for inhibition of glucose-stimulated insulin release. The contrasting response to acute leptin exposure suggests these changes are not a direct effect of the protein.
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Affiliation(s)
- R B Harris
- Neuroscience Department, Pennington Biomedical Research Center, Louisiana State University, Baton Rouge 70808, USA
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Zhou Y, Elkins PD, Howell LA, Ryan DH, Harris RB. Apolipoprotein-E deficiency results in an altered stress responsiveness in addition to an impaired spatial memory in young mice. Brain Res 1998; 788:151-9. [PMID: 9554991 DOI: 10.1016/s0006-8993(97)01533-3] [Citation(s) in RCA: 35] [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] [Indexed: 02/07/2023]
Abstract
It has been suggested that Alzheimer's disease (AD) is associated with an altered neurotrophic function of apolipoprotein-E (ApoE) and abnormal neuroendocrine activities. In the present study we investigated stress responsiveness of ApoE-deficient mice. Firstly, two sessions of restraint were introduced, 20 min per day for two (session 1) and three (session 2) consecutive days. In session 1, there was no difference between genotypes in open-field activity in response to restraint stress. In session 2, spatial memory was assessed in a Morris Water Maze 'Place Learning Set' task immediately following stress. Restraint stress caused a significant impairment of spatial memory in wild-type mice. The non-restraint ApoE-deficient mice showed a severe impairment of spatial memory similar to that of the restrained wild-type mice. Restraint stress had no obvious effect on spatial memory in ApoE-deficient mice until the third day of testing, when there was a decrease in reference memory compared with their non-restraint controls. In addition, the first session of restraint stress had an inhibitory effect on food intake in wild-type but not ApoE-deficient mice, and a longer-lasting effect on body weight in the wild-type than ApoE-deficient mice. ApoE-deficient mice showed a weaker corticosterone response to the initial restraint stress and a slower descending rate in serum corticosterone level during a 30-min post-stress period than their wild-type controls. However, higher baseline levels and stronger corticosterone responses were observed in ApoE-deficient mice than in wild-type mice when exposed to repeated restraint stress. The expression of ApoE mRNA was upregulated in the hypothalamus in wild-type mice exposed to repeated restraint stress. Taken together, these results demonstrate that ApoE deficiency causes a memory impairment and an altered stress responsiveness in mice.
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Affiliation(s)
- Y Zhou
- Pennington Biomedical Research Center, Louisiana State University, 6400 Perkins Road, Baton Rouge, LA 70808, USA.
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45
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Vilven JC, Domalewski M, Prossnitz ER, Ye RD, Muthukumaraswamy N, Harris RB, Freer RJ, Sklar LA. Strategies for positioning fluorescent probes and crosslinkers on formyl peptide ligands. J Recept Signal Transduct Res 1998; 18:187-221. [PMID: 9651885 DOI: 10.3109/10799899809047744] [Citation(s) in RCA: 14] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Chemoattractant receptors represent a major subset of the G-protein coupled receptor (GPCR) family. One of the best characterized, the N-formyl peptide receptor (FPR), participates in host defense responses of neutrophils. The features of the ligand which regulate its interaction with the FPR are well-known. By manipulating these features we have developed new ligands to probe structural and mechanistic aspects of the peptide-receptor interaction. Three ligand groups have been developed: 1) ligands containing a Lys residue located in positions 2 through 7 that can be conjugated to FITC (N-formyl-Met1-Lys2-Phe3-Phe4, N-formyl-Met1-Leu2-Lys3-Phe4, N-formyl-Met1-Leu2-Phe3-Lys4, N-formyl-Met1-Leu2-Phe3-Phe4-Lys5, N-formyl-nLeu1-Leu2-Phe3-nLeu4-Tyr5-Lys6 and N-formyl-Met1-Leu2-Phe3-Phe4-Gly5-Gly6-Lys7; 2) fluorescent pentapeptide ligands (N-formyl-Met-X-Phe-Phe-Lys(FITC) where X = Leu, Ala, Val or Gly); and 3) small crosslinking ligands where the photoaffinity crosslinker 4-azidosalicylic acid (ASA) was conjugated to Lys in positions 3 and 4 and p-benzoyl-phenylalanine (Bpa) was located in position 2 in N-formyl-Met1-Bpa2-Phe3-Tyr4. The peptides were characterized according to activity and affinity in human neutrophils and cell lines transfected with FPR. All of the peptides were agonists, with parallel affinity and activity. In the first group, the peptide activity decreases as Lys is placed closer to the N-formyl group and the activity is improved by 1-3 orders of magnitude by conjugation with FITC. In the second group, the dissociation rate of the peptide from the receptor increases as position 2 is replaced by aliphatic amino acids with smaller alkyl groups. In the third group, crosslinking ligands remain biologically active, display nM affinity and covalently label the FPR.
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Affiliation(s)
- J C Vilven
- Cancer Center and Pathology, University of New Mexico Health Sciences Center, Albuquerque, USA
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46
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Abstract
This experiment determined the amount of leptin required to correct different abnormalities in leptin-deficient ob/ob mice. Baseline food intakes and body weights of lean (+/?) and obese (ob/ob) C57B1/6J <ob> mice were recorded for 7 days. An Alzet miniosmotic pump was placed in the peritoneal cavity of each mouse and delivered 0, 1, 2, 5, 10, or 42 microg/day human leptin for 7 days. In ob/ob mice, 2 microg leptin/day reduced food intake and body weight, and increased hypothalamic and brain stem serotonin concentrations. All fat pads were reduced 35-40% by 10 microg leptin/day, and liver weight, lipid, and glycogen decreased. Serum insulin and glucose were reduced in all leptin-treated ob/ob mice, and levels were normalized by 10 microg/day leptin. Low rectal temperatures of ob/ob mice were corrected by 10 and 42 microg/day leptin. These doses also increased brown adipose tissue uncoupling protein expression. The only responses in lean mice were a transient reduction in food intake and weight loss with 10 or 42 microg/day leptin. This study shows enhanced leptin sensitivity in ob/ob mice and suggests that increased temperature and sympathetic activity are indirect responses to high concentrations of protein.
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Affiliation(s)
- R B Harris
- Pennington Biomedical Research Center, Louisiana State University, Baton Rouge 70808, USA.
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47
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Abstract
Chronic mild stress (CMS) exposes animals to unpredictable stressors. Reduced consumption of sucrose or saccharin solutions by CMS rats has been used as a putative measure of anhedonia, typical of depression. Our objective was to determine whether saccharin consumption and preference and suppression of exploratory and rearing behaviors in the open field were reliable indicators of CMS-induced behavioral depression. In Experiment 1, male Wistar rats subjected to 6 weeks of CMS consumed significantly less food and gained less weight than controls. CMS did not effect saccharin intake, or preference, measured in a two-bottle test with water. CMS rats exposed to a novel open field showed increased exploration and rearing. In a second test, performed immediately after a novel stress of restraint, there were no differences in exploratory or rearing behavior of CMS and control rats. In Experiment 2, CMS was reduced to 3 weeks and rats were single or group housed in their home cages. Open field activity of CMS rats was similar to that in Experiment 1. Saccharin preference of CMS rats was significantly suppressed when tested after 24 hours of water deprivation, but was not different from controls after 5 hours of water deprivation. In the final experiment Sprague Dawley rats behaved the same as Wistar rats in the CMS paradigm. Therefore, the CMS protocol used in these experiments did not induce behaviors indicative of depression but did cause a mild anorexia and weight loss. Saccharin intake of CMS rats was dependent upon their dehydration state and could not be attributed to stress-induced anhedonia.
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Affiliation(s)
- R B Harris
- Pennington Biomedical Research Center, Baton Rouge, LA 70808, USA.
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48
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Hanbury CM, Miller WG, Harris RB. Fiber-optic immunosensor for measurement of myoglobin. Clin Chem 1997; 43:2128-36. [PMID: 9365398] [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: 02/05/2023]
Abstract
A self-contained fiber-optic immunosensor was developed to measure the 16,500-Da protein myoglobin. The sensing element was constructed by entrapment of Cascade Blue-labeled antibody within polyacrylamide gel at the distal face of an optical fiber 300 microns in core diameter. The polyacrylamide gel composition was optimized to allow diffusion of myoglobin but to exclude hemoglobin and higher-molecular-mass proteins from the sensing area. The analytical signal was derived from fluorescence energy transfer between Cascade Blue and the heme group of myoglobin. Fluorescence quenching occurred when myoglobin bound to labeled antibody. The total amount of fluorescence quench was dependent on the antibody labeling conditions and the amount of antibody incorporated in the sensor gel matrix. Myoglobin concentrations > 5 nmol/L (83 micrograms/L) were measurable with response times of 15 to 130 min limited by diffusion into the sensing element. This report demonstrates the technical feasibility for a self-contained immunosensor to measure a protein analyte.
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Affiliation(s)
- C M Hanbury
- Department of Pathology, Medical College of Virginia, Virginia Commonwealth University, Richmond 23298-0597, USA
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49
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Rybkin II, Zhou Y, Volaufova J, Smagin GN, Ryan DH, Harris RB. Effect of restraint stress on food intake and body weight is determined by time of day. Am J Physiol 1997; 273:R1612-22. [PMID: 9374801 DOI: 10.1152/ajpregu.1997.273.5.r1612] [Citation(s) in RCA: 72] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Three experiments were conducted to investigate the effect of restraint stress applied at different times of the light-dark cycle on feeding behavior and body weight of rats. Sprague-Dawley rats were restrained for 3 h in restraining tubes either at the start or the end of the light cycle. There was a significant reduction in food intake on the day of restraint and no change in food intake during a 10-day recovery period in either experiment. Reductions of food intake on the day of restraint were about the same for both restrained groups compared with their controls. When stress was applied in the evening, eating was inhibited during the first 2 h after restraint, whereas in rats restrained in the morning, feeding was suppressed twice: during the 4 h after restraint and during the first 2 h of the dark cycle. Restraint induced a significant weight loss that was greater in the rats stressed in the morning. Neuropeptide Y (NPY) levels determined at the time of food suppression for both experiments (beginning of the dark cycle) revealed an elevation of NPY in the paraventricular nucleus of rats stressed in the morning compared with other groups, but no difference in hypothalamic NPY mRNA expression. Expression of uncoupling protein mRNA in brown adipose tissue and leptin mRNA in epididymal fat, measured at the start of the dark period, was not altered by stress. There was an elevation of dopamine turnover in the hypothalami of rats restrained at the end of light cycle, but not those restrained in the morning. These results show that restraint stress has a greater effect on metabolism and energy balance when it is applied in the morning. Additional studies are needed to elucidate mechanisms involved in the suppression of food intake 9 h after restraint.
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Affiliation(s)
- I I Rybkin
- Neuroscience Department, Pennington Biomedical Research Center, Louisiana State University, Baton Rouge 70808, USA
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50
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Harris RB, Harris JM, Hultman J, Weingarten S. Differences in costs of treatment for foot problems between podiatrists and orthopedic surgeons. Am J Manag Care 1997; 3:1577-83. [PMID: 10178462] [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] [Subscribe] [Scholar Register] [Indexed: 02/11/2023]
Abstract
We examined charge data for health insurance claims paid in 1992 for persons under age 65 covered by a large California managed care plan. Charge and utilization comparisons between podiatrists and orthopedic surgeons were made for all foot care and for two specific foot problems, acquired toe deformities and bunions. Podiatrists provided over 59% of foot care services for this commercial population of 576,000 people. Podiatrists charged 12% less per individual service than orthopedists. However, podiatrists performed substantially more procedures per episode of care and treated patients for longer time periods, resulting in 43% higher total charges per episode. Hospitalization was infrequent for all providers, although podiatrists had the lowest rates. In a managed care setting in which all providers must adhere to a preestablished fee schedule, regardless of specialty, the higher utilization by podiatrists should lead to higher overall costs. In some cases, strong utilization controls could offset this effect. We do not know if the utilization difference is due to actual treatment or billing differences. Further, we were unable to determine from the claims data if one specialty had better outcomes than the other.
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Affiliation(s)
- R B Harris
- Arizona Prevention Center, Tucson 85716, USA.
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