101
|
Mitchell K, Nakamanya S, Kamali A, Whitworth JA. Community-based HIV/AIDS education in rural Uganda: which channel is most effective? HEALTH EDUCATION RESEARCH 2001; 16:411-423. [PMID: 11525389 DOI: 10.1093/her/16.4.411] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
A process evaluation was conducted to evaluate four channels (drama, video, community educators and leaflets) used in a community-based IEC (Information, Education and Communication) HIV/AIDS intervention in rural Uganda. Semi-structured interviews (n = 37) and focus groups (n = 3) were held with community members working as field staff. In addition, two questionnaire surveys (n = 105 and n = 69) and eight focus groups were conducted with the target community. Over 85% of the community had seen at least one drama or video show. They rated them as relevant and realistic. However, the messages 'taken home' were not always those intended by the plays. Access to community educators (CEs) was not equal. The CEs had a tendency to avoid the educated, rich and their older relatives. Those who had met with a CE rated them as knowledgeable and trustworthy, but felt they would rather be taught by a trained health worker. Around 80% of the community said they had seen the leaflets, but had not necessarily read them. Although appreciated by some as reference material, low literacy levels and a lack of reading culture meant that some leaflets may have gone astray. These findings suggest that a multi-channel approach may be required to overcome weaknesses inherent in individual channels.
Collapse
|
102
|
Varticovski L, Lu ZR, Mitchell K, de Aos I, Kopecek J. Water-soluble HPMA copolymer-wortmannin conjugate retains phosphoinositide 3-kinase inhibitory activity in vitro and in vivo. J Control Release 2001; 74:275-81. [PMID: 11489507 DOI: 10.1016/s0168-3659(01)00349-2] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Phosphoinositide kinases and ATM-related genes play a central role in many physiological processes. Activation of phosphoinositide 3-kinase (PI 3-kinase) is essential for signal transduction by many growth factors and oncogenes and may contribute to tumor progression. In the nanomolar range, Wortmannin (WM), a fungal metabolite, is a potent inhibitor of type I PI 3-kinase; it covalently modifies its catalytic subunit. Because WM is soluble only in organic solvents and unstable in water, there are difficulties in its use in vivo. To generate a water-soluble WM derivative, we used a conjugate of N-(2-hydroxypropyl)methacrylamide (HPMA) copolymer and 11-O-desacetylwortmannin (DAWM), which has a slightly lower inhibitory activity than WM. We covalently attached DAWM to HPMA copolymer containing oligopeptide (GFLG) side-chains. The final product had an estimated molecular mass of 20 kDa and contained 2 wt.% of DAWM. The HPMA copolymer (PHPMA)-DAWM conjugate inhibited type I PI 3-kinase activity in vitro and growth factor-stimulated activation of Akt in vivo; it possessed approximately 50% of the inhibitory activity of DMSO solubilized WM. The specificity and stability of the PHPMA-DAWM conjugate is currently under investigation. The new water-soluble form of WM may be useful in investigations of the role of PI 3-kinase in tumor progression and other cellular biological functions in vivo.
Collapse
|
103
|
Xue W, Schneider J, Mitchell K, Jaeger M, Nanayakkara V, Talaska G, Warshawsky D. trans-3,4-dihydroxy-anti-1,2-epoxy-1,2,3,4-tetrahydrodi- benz[a,j]acridine involvement in dibenz[a,j]acridine DNA adduct formation in mouse skin consistent with Ha-ras mutation patterns in tumors. Chem Res Toxicol 2001; 14:871-8. [PMID: 11453734 DOI: 10.1021/tx010014y] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Dibenz[a,j]acridine (DBA), is a N-heteropolycyclic aromatic environmental carcinogen found in complex combustion mixtures. The major route of DBA metabolic activation is reportedly through the trans-3,4-dihydroxy-3,4-dihydroDBA (DBA-3,4-DHD). The present studies were undertaken to determine the role of trans-3,4-dihydroxy-anti-1,2-epoxy-1,2,3,4-tetrahydroDBA (DBADE) in DBA activation pathway(s), the DNA bases involved in the binding of DBA to DNA, and whether the adducts produced are consistent with the mutation pattern in the Ha-ras gene. DBA (300 microg) or 50 microg synthesized (+/-)-DBADE was applied to the back of female Hsd:ICR(Br) mice. The mice were sacrificed 48 h later, and skin DNA was isolated, hydrolyzed, and analyzed with (32)P-postlabeling. Of the four adducts produced in vivo, adduct 1 was the major adduct for DBA (>50%) and adduct 2 was the major adduct for DBADE (89%). After the reaction of (+/-)-DBADE with purine nucleotides or calf thymus (CT) DNA in vitro, 100% of the DBADE-2'-dAMP adducts and 94% of DBADE-CT DNA adducts were chromatographically identical on TLC with adduct 2 and 86% of the DBADE-2'-dGMP adducts were chromatographically consistent with adduct 1 by (32)P-postlabeling. Papillomas were induced on the backs of mice by a single application of 0.2 micromol of DBA followed by twice-weekly application of 12-o-tetra-decanoylphorbol-13-acetate (TPA, 2 microg) for 24-26 weeks. Skin carcinomas were induced by twice weekly applications of DBA (0.1 micromol) on the backs of mice. A to T and G to T transversions were found in codons 12, 13, and 61 of the Ha-ras gene in the treated mouse skin carcinoma and papilloma DNA. The mutational spectra in the Ha-ras gene are consistent with the DNA binding of DBA to dG or dA in vivo. Thus, this research has indicated that DBADE plays an important role in DBA metabolic activation and DNA binding in mouse skin, and an alternative pathway through a bis-dihydrodiol-epoxide of DBA may also be involved.
Collapse
|
104
|
Fenton KA, Copas A, Mitchell K, Elam G, Carder C, Ridgway G, Wellings K, Erens B, Field J, Johnson AM. The acceptability of urinary LCR testing for Chlamydia trachomatis among participants in a probability sample survey of sexual attitudes and lifestyles. Sex Transm Infect 2001; 77:194-8. [PMID: 11402228 PMCID: PMC1744322 DOI: 10.1136/sti.77.3.194] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
OBJECTIVES To examine the factors that influence respondents' willingness to participate in urinary testing for Chlamydia trachomatis in a general population feasibility survey of sexual attitudes and lifestyles. METHODS 199 sexually experienced, 18-44 year old participants, recruited as part of a larger (n=901) methodological study of sexual attitudes and lifestyles, were invited to provide a urine sample for chlamydial infection testing using ligase chain reaction (LCR) techniques. Analysis of the survey data and in-depth qualitative interviews were undertaken to explore the factors that influenced participants' decisions to participate. RESULTS 143/199 (72%) participants agreed to provide a urine sample. The likelihood of providing a urine sample was reduced if other individuals were present in the home at the time of interview (OR 0.42, 95% confidence interval 0.20-0.90, p=0.03). Trust and rapport with the interviewer, understanding the aims of the test, sense of obligation, and perceived importance of the test were identified as additional influencing factors in the in-depth interviews. CONCLUSIONS Survey respondents' uncertainty or embarrassment at participating in urine testing can be overcome if they are well informed, motivated by the potential health gain, and briefed by trained and confident interviewers.
Collapse
|
105
|
Hanchard B, Blake G, Wolff C, Samuels E, Waugh N, Simpson D, Ramjit C, Mitchell K. Age-specific incidence of cancer in Kingston and St Andrew, Jamaica, 1993-1997. W INDIAN MED J 2001; 50:123-9. [PMID: 11677908] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/22/2023]
Abstract
A total of 4285 malignant neoplasms were recorded in Kingston and St. Andrew during the period 1993-1997, 2344 in females and 1941 in males. The crude incidence rate per 100,000 (CIR) for males was 121.6 and for females 129.2. Age standardized rates per 100,000 (ASR) were 156.7 and 176.7 for males and females respectively. In males, the leading sites for cancer were prostate (619 cases), bronchus (265 cases) and large bowel (144 cases) while in females the leading sites were breast (627 cases) cervix uteri (376 cases) and large bowel (204 cases). The crude and age standardized incidence rates have remained stable as compared to those for the previous five year period (1998-1992). The leading sites for both males and females have also been maintained in the same order but there was a marked increase in prostate cancer (ASR 56.4 versus 36). Invasive cervical cancer has shown no significant change in incidence (ASR 25.2 versus 26.3) but the rate for in-situ cancers has decreased (ASR 27.4 versus 43.8). The incidence of cancer of the female breast has remained relatively stable (ASR 43.2 versus 47.1). The trends exhibited by both prostate cancer and in-situ cervical cancer probably represent the influence of screening methods for prostate cancer and ablative management for low grade dysplastic lesions of the cervix uteri respectively.
Collapse
|
106
|
Mitchell K. Appointment of TVIs. Vet Rec 2001; 148:417-8. [PMID: 11327654] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/19/2023]
|
107
|
Horne RS, Andrew S, Mitchell K, Sly DJ, Cranage SM, Chau B, Adamson TM. Apnoea of prematurity and arousal from sleep. Early Hum Dev 2001; 61:119-33. [PMID: 11223274 DOI: 10.1016/s0378-3782(00)00129-8] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
The incidence of sudden infant death syndrome (SIDS) has been found to be consistently higher in preterm and low birth weight infants than in infants born at term and this increase is inversely related to gestational age. The incidence and severity of apnoea of prematurity, are also inversely related to gestational age. The aim of this study was to investigate whether a neonatal history of apnoea/bradycardia affected the maturation of arousal responses. Twenty-five premature infants were studied. A perinatal risk score was determined for each infant and infants were divided into those with a neonatal history of apnoea/bradycardia (n=16) and those without (n=9). All infants were studied using daytime polysomnography on three occasions: (a) a preterm study around 36 weeks gestation, (b) within 3 weeks of term, and (c) 2-3 months post-term. Multiple measurements of arousal threshold (cm H2O) in response to air-jet stimulation applied alternately to the nares were made in both active sleep (AS) and quiet sleep (QS). Arousal thresholds were elevated in apnoeic infants compared to control infants in both AS (P<0.05) and QS (P<0.001) at the term study and in QS at 2-3 months post-term (P<0.01). In addition, arousal thresholds were positively correlated with perinatal risk score in both sleep states, in all studies, with the exception of AS at 2-3 months when all infants were readily arouseable. We conclude that a history of prematurity with neonatal apnoea has a persisting effect on decreasing arousabilty from sleep and these infants may be at increased risk for SIDS.
Collapse
|
108
|
Tobias JH, Clarke S, Mitchell K, Robins S, Amer H, Fraser WD. Analysis of the contribution of dydrogesterone to bone turnover changes in postmenopausal women commencing hormone replacement therapy. J Clin Endocrinol Metab 2001; 86:1194-8. [PMID: 11238508 DOI: 10.1210/jcem.86.3.7321] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Although gestagens have been reported to influence bone metabolism, whether these contribute to the beneficial effects of hormone replacement therapy (HRT) on the skeleton of postmenopausal women is currently unclear. To address this question, we compared changes in bone turnover markers after commencing HRT in 26 postmenopausal women randomized to receive 8 weeks of treatment with 2 mg estradiol daily or 2 mg estradiol plus 10 mg dydrogesterone daily. Serum and second morning void urine samples were obtained at baseline (twice) and after 1, 2, 4, and 8 weeks. Serum estradiol was measured by RIA, urinary total deoxypyridinoline (DPD) excretion by high pressure liquid chromatography, and serum osteocalcin and C-terminal procollagen peptide by enzyme-linked immunosorbent assay. The increase in serum estradiol after treatment with estradiol alone was slightly, but significantly, greater than that in the combination group (P = 0.04). Although estradiol suppressed urinary DPD excretion to a greater extent when given alone (P = 0.02), osteocalcin levels were significantly higher in this group than in women receiving combination therapy (P = 0.04). To assess the effect of dydrogesterone on the balance between formation and resorption in more detail, we subsequently compared the ratio between formation and resorption markers in the two treatment groups. We found that osteocalcin/DPD and C-terminal procollagen peptide/DPD ratios were significantly higher in women treated with estradiol alone (P < 0.0001 and P = 0.002, respectively), suggesting that dydrogesterone may reduce formation relative to resorption. These results suggest that gestagens may reduce estrogen's beneficial effects on the skeleton of postmenopausal women, as assessed over the first 8 weeks of replacement therapy.
Collapse
|
109
|
Savarese TM, Mitchell K, McQuain C, Campbell CL, Guardiani R, Wuu J, Ollari C, Reale F, Nelson BE, Chen A, Quesenberry PJ. Coexpression of granulocyte colony stimulating factor and its receptor in primary ovarian carcinomas. Cancer Lett 2001; 162:105-15. [PMID: 11121868 DOI: 10.1016/s0304-3835(00)00623-6] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Immunohistochemistry was used to determine the expression of granulocyte colony-stimulating factor (G-CSF) and its receptor (G-CSFR) in primary ovarian carcinomas. The expression of G-CSFR was observed in the malignant cells of each of the 46 primary carcinomas examined; G-CSF was coexpressed in both the malignant epithelial cells and the stroma of 56.5% of the specimens. Thus the majority of ovarian carcinomas harbor both potential autocrine and paracrine G-CSF axes. In 37% of the samples, G-CSF was expressed only within stromal cells, suggesting that only a potential paracrine system is in place. In a preliminary, retrospective, evaluation, the survival of patients whose tumors expressed only the apparent paracrine loop was significantly worse than patients whose tumors expressed both potential autocrine and paracrine G-CSF-based regulatory loops (14.5 vs. 42.5 months, respectively). Studies on the potential function of G-CSF were performed using the G-CSFR-expressing OVCAR-3 ovarian carcinoma line. As a single agent, rhG-CSF failed to stimulate [3H]-thymidine incorporation in these cells, but enhanced the mitogenic action of epidermal growth factor (EGF) in a dose-dependent manner. Thus, potential autocrine and/or paracrine loops involving G-CSF and its receptor occur in over 90% of primary ovarian carcinomas, and may act to modulate the action of growth factors.
Collapse
|
110
|
Mashburn K, Mitchell K. The role of the case manager in an impairment-based return-to-work process. THE CASE MANAGER 2001; 12:58-61. [PMID: 11174226 DOI: 10.1067/mcm.2001.112771] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
|
111
|
Braybrooke JP, O'Byrne KJ, Propper DJ, Blann A, Saunders M, Dobbs N, Han C, Woodhull J, Mitchell K, Crew J, Smith K, Stephens R, Ganesan TS, Talbot DC, Harris AL. A phase II study of razoxane, an antiangiogenic topoisomerase II inhibitor, in renal cell cancer with assessment of potential surrogate markers of angiogenesis. Clin Cancer Res 2000; 6:4697-704. [PMID: 11156222] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/18/2023]
Abstract
Renal cell carcinoma (RCC) is an angiogenic tumor resistant to standard cytotoxic chemotherapeutic agents. Although often responsive to immunomodulatory agents including interleukin 2 and IFN-alpha, the overall results in randomized Phase III studies are disappointing with only modest improvements in overall survival. This Phase II study evaluated the efficacy and tolerability of razoxane, an antiangiogenic topoisomerase II inhibitor, in 40 patients (32 men, 8 women; age: range, 31-76 years; median, 58 years) with inoperable RCC. Twenty patients received razoxane 125 mg p.o., twice a day for 5 days each week for 8 weeks (one cycle). This was repeated in patients with stable disease (StD), but was discontinued after 16 weeks if there was no evidence of an objective response. Because minimal toxicity was seen, subsequent patients (n = 20) were treated until progressive disease (PD) was documented. Of 38 evaluable patients, 11 (29%) had StD for a minimum of 4 months, and the remainder had PD. Median overall survival was 7.3 months. Duration of survival was significantly better in patients with StD compared with those with PD (P = 0.003). The effect of treatment on six potential surrogate serum/plasma (vascular endothelial growth factor (VEGF), basic fibroblast growth factor (bFGF), urokinase plasminogen activator soluble receptor (uPAsr), E-selectin, vascular cell adhesion molecule-1 (VCAM-1) and von Willebrand's factor (vWF) and two urinary (VEGF and bFGF) markers of angiogenesis was evaluated before and after 1 cycle of treatment. Pretreatment serum VEGF and E-selectin levels above the median value were associated with a poor prognosis. Serum VCAM-1 levels and urinary VEGF levels rose significantly after one cycle in patients with PD but not in those with StD. Serum VEGF, bFGF, VCAM-1 and vWF, plasma uPAsr and urinary bFGF levels were significantly higher in PD patients compared with StD patients before and/or after 1 cycle of treatment. In conclusion, razoxane is an antiangiogenic agent that has minimal toxicity and that requires further evaluation in combination with other active agents in the treatment of RCC. Surrogate serum and urinary markers of angiogenesis may have a role to play in predicting disease response and overall survival in RCC.
Collapse
|
112
|
Lumley J, Calpin-Davies P, Mitchell K. Student experiences in nursing homes: a placement policy gap? Nurs Older People 2000; 12:14-6. [PMID: 12008384] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/18/2023]
|
113
|
Lin E, Connolly LP, Zurakowski D, DiCanzio J, Drubach L, Mitchell K, Tetrault T, Laffin SP, Treves ST. Reproducibility of renal length measurements with 99mTc-DMSA SPECT. J Nucl Med 2000; 41:1632-5. [PMID: 11037991] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/18/2023] Open
Abstract
UNLABELLED Renal length measurements are used in evaluating several abnormalities of the pediatric genitourinary tract. This study assesses reproducibility of renal length measurements obtained with 99mTc-dimercaptosuccinic acid (DMSA) SPECT. METHODS The lengths of 98 kidneys of 51 children (age range, 1-16 y; mean age, 5.4 y) who underwent 99mTc-DMSA SPECT were measured independently by 2 observers. Renal length was calculated by converting pixels between points at the superior and inferior renal margins on a summated coronal image to centimeters. Lengths were measured for kidneys as they appeared in situ and after realignment along their long axes. SPECT reconstruction, choice of display parameters, positioning of points used for measuring, and alignment were performed independently by each observer. Interobserver variability, interobserver correlation, and mean differences between observers' measurements (expressed as measurement of observer 2 - measurement of observer 1) were calculated. RESULTS Correlation between the observers' measurements was highly significant for both nonaligned and aligned studies (r = 0.95 and 0.97, respectively; both, P < 0.0001). Interobserver variability expressed as 1 SD was 3.6 mm for nonaligned studies and 2.8 mm for aligned studies. The mean difference between the 2 observers' measurements for nonaligned studies was 2.0 +/- 4.8 mm (P < 0.0001) with a range of -11 to 14 mm. For aligned studies the mean difference between the 2 observers' measurements was -0.1 +/- 4.0 mm (P = 0.88) with a range of -20 to 10 mm. Differences between observers were not dependent on absolute renal length (P = 0.68 for nonaligned studies; P = 0.40 for aligned studies). CONCLUSION The variability in renal length measurements determined by 99mTc-DMSA SPECT is similar to that reported previously using sonography. Because the interobserver differences in renal length are similar to annual renal growth rates during childhood, caution should be applied when incorporating renal length measurements determined by 99mTc-DMSA SPECT into management algorithms. Additional studies are required to further establish interobserver variability, to assess intraobserver variability, and to evaluate means of improving standardization.
Collapse
|
114
|
Hewlett S, Mitchell K, Haynes J, Paine T, Korendowych E, Kirwan JR. Patient-initiated hospital follow-up for rheumatoid arthritis. Rheumatology (Oxford) 2000; 39:990-7. [PMID: 10986304 DOI: 10.1093/rheumatology/39.9.990] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
OBJECTIVES To evaluate the clinical efficacy, cost and acceptability of a shared care system of patient- or general practitioner (GP)-initiated hospital review in rheumatoid arthritis (RA). METHODS A 2-yr randomized controlled trial of routine rheumatologist-initiated review was compared with a shared care system. Shared care patients had no routine follow-up but patients or GPs initiated access to rapid review by the multidisciplinary team via a nurse-run helpline. Control patients had a rheumatologist-initiated medical review at intervals of 3-6 months. Clinical and psychological status, resource use, and patient and GP satisfaction and confidence were assessed. Three-monthly clinical data were assessed (blind) for safety monitoring, with failure set at a 20% increase in pain, disability or disease activity. RESULTS Two hundred and nine established RA patients participated, of whom 182 were evaluable. Safety-net failures were not different between groups. Shared care patients had less pain (24 months, 3.9 cm on a 10-cm visual analogue scale vs 4.8 cm for controls; P: < 0.05), a smaller increase in pain over 2 yr (+ 0.4 cm vs +1.6 cm for controls; P: < 0.01), greater self-efficacy (6, 15, 18, 21 months, P: < 0.05), used 33.5% less resources (208 ponds sterling per patient per year vs 313 pound sterling for controls; P: < 0.001) and were more confident in the system (6, 9, 12, 18, 21, 24 months, P: < 0.01 to P: < 0.001). CONCLUSIONS A patient-initiated system for hospital review over 2 yr offers some clinical benefit compared with the traditional system, using fewer resources and attracting greater patient confidence. Longer-term assessment of the system would be appropriate.
Collapse
|
115
|
Mitchell K. Shared care--the way forward for patient-orientated follow-up care in rheumatoid arthritis. Rheumatology (Oxford) 2000; 39:457-8. [PMID: 10852973 DOI: 10.1093/rheumatology/39.5.457] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
|
116
|
O'Brien T, Babcock G, Cornelius J, Dingeldein M, Talaska G, Warshawsky D, Mitchell K. A comparison of apoptosis and necrosis induced by hepatotoxins in HepG2 cells. Toxicol Appl Pharmacol 2000; 164:280-90. [PMID: 10799338 DOI: 10.1006/taap.2000.8917] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
7H-Dibenzo[c,g]carbazole (DBC), an N-heterocyclic aromatic hydrocarbon, is cytotoxic and carcinogenic in rodent liver. While DBC leads to necrotic lesions in the liver, the induction of apoptosis by DBC has not been investigated. The focus of this study was to determine the degree to which apoptosis and necrosis contributed to DBC cytotoxicity in a human hepatoma cell line (HepG2). To determine if these effects were unique to DBC, the results were compared to another hepatotoxin, aflatoxin B(1) (AFB(1)). DBC produced a distinct biphasic LDH release curve within 24 h of exposure. During the same time period lower concentrations of DBC (<10 microM) induced the formation of DBC-DNA adducts and increased p53 protein levels followed by apoptotic cell death. However, increasing the concentration of DBC to 80 microM led to lower DNA adduct and p53 protein levels. At this concentration, intracellular ATP levels were rapidly depleted followed by cell swelling and loss of membrane integrity consistent with necrotic cell death. In contrast to DBC, a biphasic LDH release curve was not observed for AFB(1). Instead, AFB(1) induced a concentration-dependent increase in apoptosis that reached two- to threefold higher levels than DBC. These results suggest that differences exist in the extent and type of cell death induced by DBC and AFB(1) at equimolar concentrations. Apoptosis and necrosis result from low and high concentrations of DBC, respectively, and may be dependent upon intracellular ATP levels.
Collapse
|
117
|
Lin E, Connolly LP, Drubach L, Zurakowski D, DiCanzio J, Mitchell K, Treves ST. Effect of early emptying on quantitation and interpretation of liquid gastric emptying studies of infants and young children. J Nucl Med 2000; 41:596-9. [PMID: 10768558] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/16/2023] Open
Abstract
UNLABELLED This study assesses the effect of emptying that occurs during feeding on quantitation and interpretation of liquid gastric emptying studies of infants and young children. METHODS Forty-nine 99mTc-sulfur colloid liquid gastric emptying studies of 44 children (22 boys, 22 girls; mean age, 20 mo; age range, 2-46 mo) fed orally or by gastrostomy tubes were evaluated. Gastric residuals quantitated by 2 commonly used methods, the first of which does not account for early emptying and the second of which does, were compared. With the first method, residual relative to activity in the stomach at the start of imaging (Rg) was quantified by comparing activity in a region of interest (ROI) drawn about the stomach on the final image to activity in an ROI drawn about only the stomach at the start of imaging. With the second method, residual relative to total dose (Rt) was quantified by comparing activity in the same final ROI to activity in an ROI that included stomach and small bowel at the start of imaging. Studies were interpreted independently for Rg and Rt considering a value >70% as evidence of delayed emptying. RESULTS Rt was lower than Rg by 15%-16% for the entire population, for patients fed orally, and for patients fed by gastrostomy tube. These differences reached statistical significance (P < 0.0001). In 31 of 49 studies, R1 was lower than Rg by > or =10%. In 8 studies, emptying classified as delayed on the basis of Rg was classified as nondelayed on the basis of Rt. Clinical decisions based on Rt did not require later management changes that would have indicated that treatment of gastric dysmotility had been postponed in any patient. CONCLUSION Emptying that occurs during feeding should be factored into quantitation of liquid gastric emptying in infants and young children. Not recognizing and accounting for early emptying results in overestimated gastric residuals and can lead to classification of emptying as delayed in children whose residuals of the total administered dose are within a recognized range of normal.
Collapse
|
118
|
Park JS, Boyer S, Mitchell K, Gilfor D, Birrer M, Darlington G, El Deiry W, Firestone GL, Munger K, Band V, Fisher PB, Dent P. Expression of human papilloma virus E7 protein causes apoptosis and inhibits DNA synthesis in primary hepatocytes via increased expression of p21(Cip-1/WAF1/MDA6). J Biol Chem 2000; 275:18-28. [PMID: 10617580 DOI: 10.1074/jbc.275.1.18] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The impact of human papilloma virus (HPV16) E7 proteins and retinoblastoma (RB) antisense oligonucleotides upon mitogen-activated protein kinase (MAPK)-mediated inhibition of DNA synthesis via p21(Cip-1/WAF1/MDA6) (p21) was determined in primary hepatocytes. Prolonged activation of the MAPK pathway in p21(+/+) or p21(-/-) hepatocytes caused a large decrease and increase, respectively, in DNA synthesis. Either transfection with RB antisense oligonucleotides, expression of wild type E7, or RB binding mutant E7 (C24S) proteins increased p21 levels and reduced DNA synthesis in p21(+/+) hepatocytes. RB antisense oligonucleotides and E7 proteins increased apoptosis in p21(+/+), but not p21(-/-), hepatocytes. Expression of wild type E7 increased DNA synthesis above control levels in p21(-/-) cells, which was additive with prolonged MAPK activation. In contrast, expression of mutant E7 did not alter DNA synthesis above control levels in p21(-/-) cells and was supra-additive with prolonged MAPK activation. Antisense ablation of RB in p21(-/-) hepatocytes had a weak stimulatory effect upon DNA synthesis itself but enhanced the capacity of mutant E7 protein to stimulate DNA synthesis to the same level observed using wild type E7. The ability of prolonged MAPK activation to stimulate DNA synthesis in the presence of mutant E7 and antisense RB was additive. Collectively, the present data demonstrate that loss of RB function together with loss of p21 function plays an important role in the E7- and MAPK-dependent modulation of apoptosis and DNA synthesis in primary hepatocytes.
Collapse
|
119
|
Abstract
This article briefly reviews some of the major early geriatric textbooks of the last two centuries. Among the more important are books by George Day, Charcot, Nascher, Worcester, and Cowdry. Lord Amulree's book Adding Life to Years has become a watchword of modern geriatrics. It is of interest that during this time period the basic plea for high touch care of older patients and the lament that physicians have little knowledge of the needs of older patients has remained remarkably constant.
Collapse
|
120
|
Duggan C, Lasche J, McCarty M, Mitchell K, Dershewitz R, Lerman SJ, Higham M, Radzevich A, Kleinman RE. Oral rehydration solution for acute diarrhea prevents subsequent unscheduled follow-up visits. Pediatrics 1999; 104:e29. [PMID: 10469812 DOI: 10.1542/peds.104.3.e29] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
BACKGROUND Oral rehydration solutions (ORS) for the treatment of acute diarrhea remain an underutilized therapy in the United States, despite multiple clinical trials confirming their efficacy and safety. Economic barriers to their use have been identified. OBJECTIVE To determine whether providing ORS to patients at the time of their office visit for acute diarrhea can increase ORS utilization and reduce unscheduled follow-up visits. DESIGN Randomized, controlled clinical trial. SETTING Seven health centers of a large health maintenance organization. PARTICIPANTS Children (N = 479) 0 to 60 months of age with acute diarrhea (at least three watery or loose stools in the previous 24 hours for </=7 days). INTERVENTION Prescription for 2 quarts of ORS filled for free at on-site pharmacy plus written instructions versus written instructions alone. PRIMARY OUTCOME MEASURES Self-reported use of ORS; unscheduled follow-up visits in office, urgent care, and/or emergency department setting. RESULTS Subjects in the intervention group were significantly more likely to use ORS after the initial office visit (85% vs 71%; RR: 1.19; 95% CI: 1.08-1.32). Of the standard treatment group subjects, 40 (17.3%) sought unscheduled follow-up care for diarrhea versus 27 (10.9%) of the intervention group subjects (RR: 0.63; 95% CI: 0.40-0.99). Subjects seeking unscheduled follow-up care tended to younger (15.7 vs 19.4 months old), have more stools (7.1 vs 6.2 stools), and more vomiting episodes (4.1 vs 3.0) in the 24 hours before initial evaluation than those not seeking unscheduled follow-up care. Multivariate analysis showed that randomization to the intervention group was associated with a 25% reduction in unscheduled follow-up visits for acute diarrhea. CONCLUSIONS Providing ORS to families at the time of their office visit for acute diarrhea is associated with a significant increase in ORS use and substantially reduces the need for unscheduled follow-up visits. Health maintenance organizations should consider routine provision of ORS to children presenting with acute diarrhea.
Collapse
|
121
|
Koren V, Schaake J, Mitchell K, Duan QY, Chen F, Baker JM. A parameterization of snowpack and frozen ground intended for NCEP weather and climate models. ACTA ACUST UNITED AC 1999. [DOI: 10.1029/1999jd900232] [Citation(s) in RCA: 422] [Impact Index Per Article: 16.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
|
122
|
Philip PA, Rea D, Mitchell K, Carmichael J, Harris AL, Talbot DC. A pilot study of increasing dose intensity of epirubicin and ifosfamide in patients with small cell lung cancer by using recombinant granulocyte colony-stimulating factor. Clin Oncol (R Coll Radiol) 1999; 11:84-9. [PMID: 10378632 DOI: 10.1053/clon.1999.9019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
The aim of this prospective study was to investigate the feasibility of increasing the dose intensity of chemotherapy in patients with small cell lung cancer (SCLC) by using recombinant human granulocyte colony-stimulating factor (r-metHuG-CSF). Seventeen previously untreated patients (11 male, 6 female) were treated with ifosfamide (5.0 g/m2) and epirubicin (80 mg/m2) in two successive cohorts. Eight patients received chemotherapy every 2 weeks and r-metHuG-CSF 5 microg/kg given subcutaneously daily for 10 days (cohort A), and nine patients received chemotherapy at 10-day intervals with r-metHuG-CSF 5 microg/kg subcutaneously given daily for 7 days (cohort B). The relative dose intensity compared with the conventional 3-weekly regimen was 1.5 and 2.1 for cohorts A and B, respectively. Neutropenia-associated fever complicated two and five treatment courses in cohorts A and B, respectively. There were five episodes of grade 3/4 thrombocytopenia. There were no treatment delays in cohort A and one cycle was delayed in cohort B. One patient from each cohort was withdrawn due to toxicity. Grade 3/4 non-haematological toxicity, other than alopecia, was not observed. This study confirms that it is feasible to increase the relative dose intensity of ifosfamide and epirubicin in patients with SCLC to 2.1 by using r-metHuG-CSF and shortening the interval between treatment cycles.
Collapse
|
123
|
O'Byrne KJ, Dobbs N, Propper DJ, Braybrooke JP, Koukourakis MI, Mitchell K, Woodhull J, Talbot DC, Schally AV, Harris AL. Phase II study of RC-160 (vapreotide), an octapeptide analogue of somatostatin, in the treatment of metastatic breast cancer. Br J Cancer 1999; 79:1413-8. [PMID: 10188884 PMCID: PMC2362707 DOI: 10.1038/sj.bjc.6690226] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
RC-160 (octastatin/vapreotide) is a potent octapeptide analogue of somatostatin with growth inhibitory activity in experimental tumours in vitro and in vivo, including breast cancer. We evaluated the efficacy and tolerability of high-dose RC-160, 3 mg day(-1) on week 1 increased to 4.5 mg day(-1) for weeks 2-4 and subsequently 6 mg day(-1) until the end of treatment, administered by continuous subcutaneous infusion in the management of 14 women with previously treated metastatic breast cancer. The age range was 37-80 years (median 58.5 years) and performance status 0-2. The treatment was well tolerated with no dose reductions being required. No grade 3 or 4 toxicities were seen. Abscess formation developed at the infusion site in eight patients and erythema and discomfort was seen in a further three patients. A significant reduction in IGF-I levels occurred by day 7 and was maintained throughout the treatment. The lowest dose of RC-160 produced the maximal IGF-I response. Although there was no reduction in prolactin levels in patients whose baseline levels were normal, elevated prolactin levels found in three patients fell to within the normal range 7 days after commencing RC-160 treatment. A small but significant rise in fasting blood glucose levels was also recorded, the highest level on treatment being 7.6 mmol l(-1). No objective tumour responses were observed, all patients showing disease progression within 3 months of commencing treatment. These findings demonstrate that high-dose RC-160, administered as a continuous subcutaneous infusion, can reduce serum levels of the breast growth factors IGF-I and prolactin but is ineffective in the management of metastatic breast cancer. Encouraging preclinical anti-tumour activity and the favourable toxicity profile in patients suggest the merit of future studies combining RC-160 with anti-oestrogen, cytotoxic and anti-angiogenic agents.
Collapse
|
124
|
Harlow LL, Rose JS, Morokoff PJ, Quina K, Mayer K, Mitchell K, Schnoll R. Women HIV sexual risk takers: related behaviors, interpersonal issues, and attitudes. WOMEN'S HEALTH (HILLSDALE, N.J.) 1999; 4:407-39. [PMID: 9916547] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 02/10/2023]
Abstract
HIV and AIDS is a growing health risk for heterosexual women, particularly women of color (Centers for Disease Control and Prevention, 1997). Our research identified 5 types of HIV sexual risk taking in 3 independent samples of adult women from a New England Community: Group A women were noted by low to moderate levels of the 4 risk markers (i.e., unprotected vaginal sex, perceived partner-related risk, number of sexual partners, and unprotected anal sex); Group B women reported very high frequency of unprotected vaginal sex; Group C women were characterized by unprotected anal sex; Group D women had high perceived partner risk; and Group E women reported extremely high levels on all 4 HIV risk markers. Sexual risk groups were validated by demonstrating significant differences among groups on relevant behaviors, interpersonal experiences, and attitudes. Compared to other women, higher risk types reported greater behavioral risk practices (substance use, prostitution, diverse sexual experience), interpersonal risk experiences (sexual abuse, violence), initiation sexual assertiveness, and attitudinal risks (psychosocial distress). They reported less interpersonal assurance (surety of own and partner's HIV status), sexual assertiveness (for condom use and partner communication), psychosocial strengths (sexual self-acceptance), and transtheoretical readiness for change (condom use efficacy, readiness to consider condoms). Results provide additional support for the multifaceted model of HIV risk and the transtheoretical model. Suggestions for specifically focused interventions are given, depending on the pattern of sexual risk taking.
Collapse
|
125
|
Mitchell K, Wellings K. First sexual intercourse: anticipation and communication. Interviews with young people in England. J Adolesc 1998; 21:717-26. [PMID: 9971728 DOI: 10.1006/jado.1998.0191] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
This study investigated anticipation and communication around first sexual intercourse through semi-structured interviews with young people (aged 16 to 29) in England. Ranging from surprise to pre-planning, several different levels of anticipation are explored. The main findings are as follows: communication plays a central role, mediating between the degree of anticipation and the degree to which first intercourse is wanted, protected and enjoyed. First intercourse tends to be characterized by silence, especially during early, spontaneous encounters. Silence does not imply lack of communication-non-verbal communication plays an important role. Where young people are ambivalent, verbal and non-verbal communication may send contradictory messages. The implications of the results for future safer sex campaigns are discussed.
Collapse
|