Biomedical subjects
Publications and source records attributed to S James.
A trust where a third of the workforce is a member of ethnic minority groups has set up a programme to enhance career advancement for this group. The programme aims to celebrate the achievements of ethnic minority staff and give them greater visibility within the organisation. Mentoring programmes and learning sets have been established with the support of senior.
A collection of 56 bacteria isolated from different surfaces in the marine environment were assayed for their effects on the germination of spores from the common green alga Ulva lactuca. Thirteen bacterial isolates were shown to inhibit spore germination. Of these bacteria, Pseudoalteromonas tunicata displayed the most pronounced effects against algal spores. Further characterisation of the anti-algal activity of P. tunicata was performed and it was found that this bacterium produces an extracellular component with specific activity toward algal spores that is heat-sensitive, polar and between 3 and 10 kDa in size. This biologically active compound was also found to prevent the germination of spores from the red alga Polysiphonia sp. and, given the widespread occurrence of P. tunicata in a range of marine habitats, this may suggest that it is effective against a variety of marine algae.
Different strategies using creatine kinase-MB(mass), myoglobin, and troponin T were compared in 738 patients admitted because of chest pain and an electrocardiogram not diagnostic of acute myocardial infarction. We conclude that a combination of creatine kinase-MB and troponin T during the first 6 hours enables early detection or exclusion of acute myocardial infarction in this population.
PURPOSE: The overall goals of this study were: 1) to determine whether (and if so, the extent to which) African-Americans differed in their willingness to participate in biomedical studies as compared to non-Hispanic Whites, and 2) to determine the influence that a range of demographic, psycho-social and medico-historical variables had on the comparative willingness of these groups to participate in biomedical research. This report will present preliminary findings on the first goal.METHODS: The Tuskegee Legacy Project (TLP) Questionnaire, a 60 item instrument developed within the Northeastern Minority Oral Health Research Center (a P50 Center supported by the National Institute of Dental and Craniofacial Research at NIH), was administered via a random-digit dial telephone interview by the University of Alabama at Birmingham Survey Research Unit to 840 adult African-Americans and Whites in three city/county areas: Birmingham/Jefferson Cty, AL; Hartford/Hartford Cty, CT and Tuskegee/Macon Cty, AL.RESULTS: The response rates were 70%, 65% and 49% for Birmingham, Tuskegee and Hartford, respectively. A lower percentage of African-Americans (21%) reported that they were either somewhat or very likely to participate as biomedical research subjects than did Whites (29%) (p < 0.0001). In response to 7 prompts on 'who' was conducting a study, African-Americans indicated they were less likely to participate than Whites on 4 specific prompts and more likely to participate on only 1 prompt (p < 0.006 for each). In response to 9 prompts on 'what' a study asked participants to do, African-Americans indicated they were less likely to participate than Whites on only 2 specific prompts (p < 0.001 for each), more likely to participate on 2 prompts (p < 0.001), and were equally or near equally likely to participate on 5 prompts.CONCLUSIONS: The findings from this study show that African-Americans self-reported a lower willingness to participate in biomedical studies than did non-Hispanic Whites, and that African-American subjects were more influenced by the factor of 'who' was running the study than by the factor of 'what' they might have to do as study subjects. Study supported by grant P 50 DE10592 from the NIDCR at NIH.
Nutritional status and risk factors for chronic diseases, including plasma fibrinogen and its determinants, of Africans in the Northwest Province of South Africa, have been studied in a cross-sectional survey. A representative sample of 1854 "apparently healthy" African men and women volunteers aged 15 years and older was recruited from 37 randomly selected sites throughout the Province and stratified for level of urbanisation. Information was collected using validated and culture-sensitive questionnaires. Fasting blood samples were drawn, and all measurements were done with standardised methodology using appropriate equipment, procedures, and controls. Fibrinogen concentration was measured in citrated plasma with the method of Clauss, using the ACL200 automated system and the international fibrinogen standard. The results revealed a population with a high mean plasma fibrinogen (3.17+/-1.10 g/L for HIV-negative men and 3. 64+/-1.12 g/L for HIV-negative women). Factors known to influence plasma fibrinogen, such as age, gender, smoking habit, and physical activity, were also observed in this population. Young rural men and women had the lowest fibrinogen level. Nasal snuff taking and HIV infection did not influence fibrinogen concentration. Multivariate analyses revealed that lower plasma fibrinogen was associated with low to normal body mass index in women, and with dietary intakes compatible with prudent dietary guidelines in men and women (low intakes of animal protein; trans fatty acids and higher intakes of plant protein; dietary fibre, vitamin E, and iron, and a high dietary P/S ratio). Subjects in the higher quartiles of plasma fibrinogen had significantly lower iron, vitamin E, and vitamin B6 (women) status. Increases in fibrinogen were associated with significant increases in serum lipids. Both under- and overnutrition seem to be associated with high plasma fibrinogen. It is concluded that overall nutritional status, possibly in addition to specific nutrients (and foods), influences plasma fibrinogen.
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A mathematical model has been developed based on the fundamental properties of the control system formed by the lux genes and their products in Vibrio fischeri. The model clearly demonstrates how the components of this system work together to create two, stable metabolic states corresponding to the expression of the luminescent and non-luminescent phenotypes. It is demonstrated how the cell can "switch" between these steady states due to changes in parameters describing metabolic processes and the extracellular concentration of the signal molecule N-3-oxohexanoyl-l-homoserine lactone. In addition, it is shown how these parameters influence how sensitive the switch mechanism is to cellular LuxR and N-3-oxohexanoyl-l-homoserine lactone and complex concentration. While these properties could lead to the collective phenomenon known as quorum sensing, the model also predicts that under certain metabolic circumstances, basal expression of the lux genes could cause a cell to luminesce in the absence of extracellular signal molecule. Finally, the model developed in this study provides a basis for analysing the impact of other levels of control upon lux regulation.
This article examines the cumulative effects of multiple stressors on women's health, by race and area of residence. Specifically, we examine socioeconomic status, experiences of unfair treatment and acute life events by race and residential location, and their cumulative effects on the health status of African American and white women living within the city of Detroit and in the surrounding metropolitan area. African American women, regardless of whether they live inside or outside the city, report more frequent encounters with everyday unfair treatment than white women. African American women who live in the city report a greater number of acute life events than white women who live outside the city. Regression analyses used to examine the cumulative effects of exposure to these stressors by race and area of residence show that: (1) socioeconomic status, everyday experiences with unfair treatment and acute life events each make a significant contribution to differences in health status; and (2) the contribution of each of these variables to explaining variations in health status varies by area of residence. We suggest that differences in socioeconomic status, exposure to unfair treatment or discrimination and experiences of acute life events make significant contributions to racial differences in women's health status.
We report on the pregnancy management of a 22-year-old woman with amyoplasia, the commonest type of arthrogryposis multiplex congenita (AMC). Extrapolating from childhood and adult studies, the majority of cases are likely to be ambulatory and live independent lives as adults. Many females, therefore, would be expected to achieve a pregnancy. There have been several case reports on anaesthetic management for Caesarean section delivery in women with arthrogryposis, but no medical literature exists regarding the likelihood or management of vaginal delivery. This is the first reported case of conservative management of a woman with amyoplasia. A multi-disciplinary team was involved in her care. This involved careful assessment of her suitability for vaginal delivery, possible anaesthetic complications and potential difficulties in caring for an infant at home. Induction of labour at 37 weeks gestation resulted in the successful vaginal delivery of a liveborn healthy male.
BACKGROUND: Targeting resources on cost-effective care strategies is important for the global mental health burden. AIMS: To demonstrate cost-outcome methods in the evaluation of mental health care programmes in low-income countries. METHOD: Four rural populations were screened for psychiatric morbidity. Individuals with a diagnosed common mental disorder were invited to seek treatment, and assessed prospectively on symptoms, disability, quality of life and resource use. RESULTS: Between 12% and 39% of the four screened populations had a diagnosable common mental disorder. In three of the four localities there were improvements over time in symptoms, disability and quality of life, while total economic costs were reduced. CONCLUSION: Economic analysis of mental health care in low-income countries is feasible and practicable. Our assessment of the cost-effectiveness of integrating mental health into primary care was confounded by the naturalistic study design and the low proportion of subjects using government primary health care services.
In the sheep there is a rapid increase in fetal adrenal growth and steroidogenesis during the last 10-15 days gestation (term = 147+/-3 days gestation). In the rat, peptides derived from the N-terminal region of POMC play a role in compensatory adrenal growth and in potentiation of ACTH-induced steroidogenesis. We therefore investigated the effects of infusion of bovine N-POMC-(1-77) and its biosynthetic derivative, N-POMC-(1-49) on adrenal growth and on the expression of adrenal steroidogenic enzymes in the late gestation sheep fetus. Twenty-seven pregnant ewes were used in this study. Fetal vascular catheters were inserted between 116-125 days gestation, and purified bovine N-POMC-(1-77) (2 microg/ml x h), N-POMC-(1-49) (2 microg/ml x h) and saline were each infused for 48 h between 136 and 138 days gestation. Intrafetal infusion of N-POMC-(1-77) resulted in an increased adrenal/fetal body weight ratio (94.6+/-5.7 mg/kg) compared with that in saline-infused (75.6+/-1.8 mg/kg), but not N-POMC-(1-49)-infused (82.7+/-6.1 mg/kg), fetal sheep. The ratio of CYP17 messenger RNA (mRNA) to 18S ribosomal RNA was also significantly higher in fetal adrenals ofthe N-POMC-(1-77)-infused group (49.1+/-4.7) compared with that in either the N-POMC-(1-49)-infused (20.4+/-6.4) or saline-infused (15.2+/-4.4) group. There was no difference, however, in the ratios of adrenal CYP11A1 mRNA/3beta-hydroxysteroid dehydrogenase/delta5,delta4-isomerase mRNA and CYP21A1 mRNA/18S ribosomal RNA among the N-POMC-(1-77)-, N-POMC-(1-49)-, and saline-infused groups. There was also no significant change in either plasma cortisol or ACTH concentrations in response to the infusion of either N-POMC-(1-77) or N-POMC-(1-49). In summary, intrafetal infusion of N-POMC-(1-77) stimulated fetal adrenal growth and resulted in a specific increase in adrenal CYP17 gene expression in late gestation. N-POMC-(1-77) may therefore play a modulatory role in the increase in fetal adrenal growth and steroidogenesis that occurs before birth.
In the sheep, there is a rapid increase in fetal adrenal growth and steroidogenesis during the last 10-15 days gestation. Recently, we have shown that infusion of POMC (1-77) increases fetal adrenal growth and expression of CYP17 mRNA but does not significantly alter fetal plasma cortisol concentrations [1]. We therefore investigated the effects of infusion of bovine POMC (1-77) and its biosynthetic derivative POMC (1-49) on adrenal StAR mRNA expression. At 136d gestation, POMC (1-77) (n=5 fetuses; 2microg/ml/h), POMC (1-49) (n=5 fetuses, 2microg/ml/h) or Saline (n=5 fetuses, 1ml/h) was infused for 48h. At 138d, fetal adrenal glands were collected and frozen in liquid N2 until RNA was extracted. Northern blot analyses demonstrated a major transcript for StAR mRNA at 3.0kb in fetal adrenal glands from all treatments. The membrane was stripped and re-probed with a P-labelled rat 18S rRNA oligo-probe to verify equal RNA loading. Infusion of POMC (1-77), but not POMC (1-49), resulted in a suppression of fetal adrenal StAR mRNA:18S rRNA when compared to adrenal StAR mRNA:18S rRNA from saline-infused controls. Our data suggest POMC (1-77) may act via separate mechanisms to increase fetal adrenal growth and to limit adrenal steroidogenesis through suppression of StAR mRNA.
OBJECTIVE: Many organizations make efforts to identify future pediatric leaders, often focusing on chief residents (CRs). Identifying future leaders is an issue of great importance not only to the ultimate success of the organization but also to the profession. Because little is known regarding whether completing a CR predicts future leadership in medicine, we sought to determine if former pediatric CRs when compared with pediatric residents who were not CRs reported more often that they were leaders in their profession. DESIGN/METHODS: Twenty-four pediatric training programs stratified by resident size (<18, 18-36, and >36) and geography (East, South, Midwest, and West) were selected randomly from the Graduate Medical Education Directory (American Medical Association, Chicago, IL). Program directors were contacted by mail and telephone and asked to provide their housestaff rosters from 1965-1985. The resulting resident sample was surveyed by questionnaire in 1995. RESULTS: Fifteen of 17 program directors (88%) who possessed the requested data provided 1965-1985 rosters yielding a sample of 963 residents. Fifty-five percent of the resident sample (533) responded. Fifty-eight of the respondents had not completed a pediatric residency, leaving a survey sample of 475. Thirty-four percent (163) were CRs. The sample had a mean age of 47, 67% were male and 87% married. Fellowships were completed by 51%. More former CRs compared with non-CRs (75% vs 64%), more former fellows than non-fellows (75% vs 60%) and more males than females (74% vs 55%) reported they were professional leaders. These associations persisted in a logistic regression that controlled for CR status, gender, marital status, and fellowship status as leadership predictors. Former CRs, former fellows, and men were, respectively, 1.8, 2.3, and 2.3 times more likely to report professional leadership. CONCLUSIONS: Pediatric residents who were former CRs and/or fellows, and males were more likely to report professional leadership. Although men were more likely to report professional leadership, with more women entering pediatrics the reported gender differences will likely disappear over time.
Mice immunized with radiation-attenuated cercariae of Schistosoma mansoni display resistance to challenge infection, which increases with multiple boosting. Protection in animals receiving a single vaccination is thought to involve a primarily cell-mediated, IFN-gamma-dependent mechanism, while humoral immunity has been shown to contribute to challenge rejection in multiply (three times) immunized mice. To better understand the respective contribution of the B lymphocyte- and IFN-gamma-dependent effector arms in host resistance, we compared vaccine-induced immunity in B cell-deficient (muMT) and IFN-gamma knockout (GKO) animals. Unexpectedly, after a single vaccination, B cell knockout (KO) mice displayed reduced protection against challenge infection, although they developed a normal IFN-gamma-dominated cytokine response. This defect in resistance was equivalent to that displayed by GKO animals. Moreover, whereas two additional vaccinations significantly increased the level of immunity in wild-type mice, the protection in B cell KO animals remained unchanged. In contrast, multiple vaccination resulted in increased but, nevertheless, defective resistance in GKO mice. Since FcR gamma KO mice, which lack functional FcgammaRI, FcgammaRIII, and FcepsilonRI, show no defects in vaccine-induced resistance after immunization either one or three times, the B cell-dependent mechanism of protection involved does not appear to require FcR signaling. Together, these findings indicate that effective vaccination against schistosomes depends on the simultaneous induction of both humoral and cell-mediated immunity, a conclusion that may explain the limited success of most subunit vaccine protocols designed to preferentially induce either B cell- or IFN-gamma-dependent protective mechanisms.
Patients with chronic hepatitis C who have not had a sustained hepatitis C virus (HCV)-RNA response or serum alanine transaminase (ALT) response to a 6-month course of interferon (IFN) may respond to higher dose retreatment with consensus interferon (CIFN). Some nonresponders to initial IFN treatment have a transient response defined as undetectable HCV RNA or normalization of ALT during treatment, but subsequently have a "breakthrough" while still on treatment. The aim of this study was to determine if nonresponders who had breakthroughs responded differently to CIFN retreatment than nonresponders without breakthroughs using data from a large, multicenter trial. ALT and HCV RNA were monitored frequently during initial IFN therapy (either 9 mcg CIFN or 3 MU IFN-alpha2b 3 times per week). HCV-RNA breakthroughs were observed in 86 of 467 (18%) of all treated patients, and ALT breakthroughs were observed in 90 of 467 (19%) of all treated patients. There was no association between breakthroughs and the presence of either binding or neutralizing anti-IFN antibodies. When the patients who were nonresponders to initial IFN treatment were retreated with CIFN (15 mcg) for 12 months, 27% of those with viral breakthroughs had a sustained viral response compared with 8% in prior nonresponders without breakthroughs (P =.102). Sustained ALT responses were observed in 39% with breakthroughs compared with 10% in those without breakthroughs (P =.014). The data suggest that prior nonresponders with breakthroughs have a greater chance of responding to retreatment than do nonresponders without breakthroughs. However, most breakthrough patients would be missed unless repeated HCV-RNA testing were conducted during therapy.
Upon air oxidation, a peptide corresponding to the 30-residue N-terminal subdomain of carp granulin-1 spontaneously formed the disulfide pairing observed in the native protein. Structural characterization using NMR showed the presence of a defined secondary structure within this peptide. The chemical shifts for most of the alphaCH protons of the peptide and the protein are very similar, and the observed NOE contacts of the peptide strongly resemble those in the protein. A structure calculation of the peptide using NOE distance constraints indicates that the peptide fragment adopts the same conformation as formed within the native protein. The 30-residue N-terminal peptide of carp granulin-1 is the first example of an independently folded stack of two beta-hairpins reinforced by two interhairpin disulfide bonds. Two key areas of the structure show a clustering of hydrophobic residues that may account for its exceptional conformational stability.
Preprocortistatin (PPCST) has been recently identified as a novel somatostatin (SST)-related gene expressed only in brain. PPCST shares 11 of 14 residues with SST-14 at its C-terminal segment, where it features Lys-Lys and Lys-Arg basic sites for cleavage to putative cortistatin (CST)-14 and CST-29 peptides, respectively. Although synthetic replicates of the two putative CST peptides interact with SST receptors, they also display novel effects suggesting independent biological functions. Nothing is currently known about the naturally occurring mature cleavage products of PPCST posttranslational processing. Here we have cloned rat PPCST cDNA, stably expressed it in AtT-20 pituitary cells, and characterized the cellular and releasable products of PPCST processing by HPLC and radioimmunoassay using a SST-14 antibody that recognizes synthetic CST-14 and CST-29. Transfected cells released 120 +/- 21 pg of total CST-LI per plate basally, with an increase to 204 +/- 33 pg per plate with forskolin stimulation (p < 0.05). HPLC chromatograms of cell extracts revealed three peaks corresponding to CST-14, CST-29, and unprocessed PPCST (ratio, 41:55:4.5). CST was released preferentially as CST-14 (63-70%) compared with CST-29 (30-37%) under basal and forskolin-stimulated conditions. These studies demonstrate efficient processing of PPCST to both CST-14 and CST-29 through putative cleavage at both C-terminal dibasic sites of PPCST. Although the two peptides are synthesized approximately equally, CST-14 is released preferentially via the regulated secretory pathway.
We have used a sensitive bioassay of calcium-mediated volume changes in mammalian absorptive intestinal epithelial cells to screen extracts of the skin of the amphibian Xenopus laevis for the presence of factors affecting ion transport. A 66-residue peptide, purified using reversed-phase high performance liquid chromatography techniques, caused isotonic volume reduction of guinea pig jejunal villus cells in suspension. This volume reduction required extracellular Ca2+ and was prevented by the dihydropyridine-sensitive Ca2+ channel blocker niguldipine. Structural analysis demonstrated the presence of eight cysteines and a primary structure homologous to that of the neurotoxin/cytotoxin family found in the venom of certain poisonous snakes. The structure of the peptide was identical to that of xenoxin-1 purified from dorsal gland secretions of X. laevis (Kolbe, M., Huber A., Cordier, P., Rasmussen, U., Bouchon, B., Jaquinod, M., Blasak, R., Detot, E., and Kreil, G. (1993) J. Biol. Chem. 268, 16458-16464). Xenoxin-1 (10 nM) caused volume changes that required extracellular Ca2+ and were comparable in magnitude and direction to changes caused by BayK-8644 (100 nM), a dihydropyridine-sensitive Ca2+ channel agonist. The initial rate of dihydropyridine-sensitive 45Ca2+ influx was substantially increased by xenoxin-1. Staurosporine (10 nM) prevented volume changes caused by ATP (250 microM) but had no effect on volume changes caused by BayK-8644 or xenoxin-1. We conclude that xenoxin-1 directly activated dihydropyridine-sensitive Ca2+ channels in villus cells and that a mammalian homologue to xenoxin-1 may exist.