Search PubMed⌕ Search

Biomedical subjects

S James

Publications and source records attributed to S James.

At least 19 recordsLinked to original sources
PubMed2000

Willingness to participate in biomedical research. African-americans vs whites.

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.

Journal Article↗
PubMed2000

Nutritional status influences plasma fibrinogen concentration: evidence from the THUSA survey.

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.

Adolescent↗
PubMed2000

Luminescence control in the marine bacterium Vibrio fischeri: An analysis of the dynamics of lux regulation.

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.

4-Butyrolactone↗
PubMed2000

Integration of mental health care into primary care. Demonstration cost-outcome study in India and Pakistan.

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.

Adult↗
PubMed2000

Infusion of N-proopiomelanocortin-(1-77) increases adrenal weight and messenger ribonucleic acid levels of cytochrome P450 17alpha-hydroxylase in the sheep fetus during late gestation.

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.

Adrenal Glands↗
PubMed2000

Does being a chief resident predict leadership in pediatric careers?

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.

Adult↗
PubMed1999

Optimal vaccination against Schistosoma mansoni requires the induction of both B cell- and IFN-gamma-dependent effector mechanisms.

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.

Administration, Cutaneous↗
PubMed1999

Chronic hepatitis C virus patients with breakthroughs during interferon treatment can successfully be retreated with consensus interferon. The Consensus Interferon Study Group.

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.

Alanine Transaminase↗
PubMed1999

A 30-residue fragment of the carp granulin-1 protein folds into a stack of two beta-hairpins similar to that found in the native protein.

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.

Amino Acid Sequence↗
PubMed1999

Processing of rat preprocortistatin in mouse AtT-20 cells.

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.

Animals↗
PubMed1998

Isolation of a member of the neurotoxin/cytotoxin peptide family from Xenopus laevis skin which activates dihydropyridine-sensitive Ca2+ channels in mammalian epithelial cells.

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.

3-Pyridinecarboxylic acid, 1,4-dihydro-2,6-dimethy↗
PubMed1998

COI1: an Arabidopsis gene required for jasmonate-regulated defense and fertility.

The coi1 mutation defines an Arabidopsis gene required for response to jasmonates, which regulate defense against insects and pathogens, wound healing, and pollen fertility. The wild-type allele, COI1, was mapped to a 90-kilobase genomic fragment and located by complementation of coi1-1 mutants. The predicted amino acid sequence of the COI1 protein contains 16 leucine-rich repeats and an F-box motif. It has similarity to the F-box proteins Arabidopsis TIR1, human Skp2, and yeast Grr1, which appear to function by targeting repressor proteins for removal by ubiquitination.

Acetates↗
PubMed1998

Pseudoalteromonas tunicata sp. nov., a bacterium that produces antifouling agents.

A dark-green-pigmented marine bacterium, previously designated D2, which produces components that are inhibitory to common marine fouling organisms has been characterized and assessed for taxonomic assignment. Based on direct double-stranded sequencing of the 16S rRNA gene, D2T was found to show the highest similarity (93%) to members of the genus Pseudoalteromonas. The G + C content of D2T is 42 mol%, and it is a facultatively anaerobic rod and oxidase-positive. D2T is motile by a sheathed polar flagellum, exhibited non-fermentative metabolism and required sodium ions for growth. The strain was not capable of using citrate, fructose, sucrose, sorbitol and glycerol but it utilizes mannose and maltose and hydrolyses gelatin. The molecular evidence, together with phenotypic characteristics, showed that this bacterium which produces an antifouling agent constitutes a new species of the genus Pseudoalteromonas. The name Pseudoalteromonas tunicata is proposed for this bacterium, and the type strain is D2T (= CCUG 26757T).

Animals↗
PubMed1998

Inhibition of murine splenic and mucosal lymphocyte function by enteric bacterial products.

Previously we showed that lysates of enteropathogenic Escherichia coli (EPEC) inhibit lymphokine production by mitogen-activated human peripheral blood and lamina propria mononuclear cells. The aims of the present study were to determine whether EPEC-inhibitory factors have similar effects on murine lymphoid populations in order to further delineate the mechanisms of alteration of cytokine production. Preexposure to EPEC lysates inhibited mitogen-stimulated interleukin-2 (IL-2), IL-4, and gamma interferon (IFN-gamma) production by murine spleen cells, but IL-10 production was increased. The inhibition was not due to increased apoptosis and was not blocked by neutralizating antibodies against IL-10 or transforming growth factor beta (TGF-beta). EPEC lysates also inhibited mitogen-stimulated IL-2 and IFN-gamma production by CD11b-depleted spleen cells, IL-2 and IL-4 production by intraepithelial and Peyer's patch lymphocytes, IL-2 production by the human T-cell line Jurkat, and antigen-stimulated IL-2 production by murine spleen cells. Lysates obtained from Shiga-like toxin-producing E. coli, E. coli RDEC-1, Citrobacter rodentium, and an EPEC espB insertion mutant all inhibited IL-2 and IL-4 production by mitogen-stimulated lymphoid cells. In conclusion, lysates of EPEC and related bacteria directly inhibit cytokine production by lymphoid cells from multiple sites by a mechanism that does not increase apoptosis or result from secondary effects of IL-10 or TGF-beta.

Animals↗
PubMed1998

Predictors of homelessness among families in New York City: from shelter request to housing stability.

OBJECTIVES: This study examined predictors of entry into shelter and subsequent housing stability for a cohort of families receiving public assistance in New York City. METHODS: Interviews were conducted with 266 families as they requested shelter and with a comparison sample of 298 families selected at random from the welfare caseload. Respondents were reinterviewed 5 years later. Families with prior history of shelter use were excluded from the follow-up study. RESULTS: Demographic characteristics and housing conditions were the most important risk factors for shelter entry; enduring poverty and disruptive social experiences also contributed. Five years later, four fifths of sheltered families had their own apartment. Receipt of subsidized housing was the primary predictor of housing stability among formerly homeless families (odds ratio [OR] = 20.6, 95% confidence interval [CI] = 9.9, 42.9). CONCLUSIONS: Housing subsidies are critical to ending homelessness among families.

Adult↗
PubMed1997

Intraoperative intravascular volume optimisation and length of hospital stay after repair of proximal femoral fracture: randomised controlled trial.

OBJECTIVES: To assess whether intraoperative intravascular volume optimisation improves outcome and shortens hospital stay after repair of proximal femoral fracture. DESIGN: Prospective, randomised controlled trial comparing conventional intraoperative fluid management with repeated colloid fluid challenges monitored by oesophageal Doppler ultrasonography to maintain maximal stroke volume throughout the operative period. SETTING: Teaching hospital, London. SUBJECTS: 40 patients undergoing repair of proximal femoral fracture under general anaesthesia. INTERVENTIONS: Patients were randomly assigned to receive either conventional intraoperative fluid management (control patients) or additional repeated colloid fluid challenges with oesophageal Doppler ultrasonography used to maintain maximal stroke volume throughout the operative period (protocol patients). MAIN OUTCOME MEASURES: Time declared medically fit for hospital discharge, duration of hospital stay (in acute bed; in acute plus long stay bed), mortality, perioperative haemodynamic changes. RESULTS: Intraoperative intravascular fluid loading produced significantly greater changes in stroke volume (median 15 ml (95% confidence interval 10 to 21 ml)) and cardiac output (1.2 l/min (0.1 to 2.3 l/min)) than in the conventionally managed group (-5 ml (-10 to 1 ml) and -0.4 l/min (-1.0 to 0.2 l/min)) (P < 0.001 and P < 0.05, respectively). One protocol patient and two control patients died in hospital. In the survivors, postoperative recovery was significantly faster in the protocol patients, with shorter times to being declared medically fit for discharge (median 10 (9 to 15) days v 15 (11 to 40) days, P < 0.05) and a 39% reduction in hospital stay (12 (8 to 13) days v 20 (10 to 61) days, P < 0.05). CONCLUSIONS: Proximal femoral fracture repair constitutes surgery in a high risk population. Intraoperative intravascular volume loading to optimal stroke volume resulted in a more rapid postoperative recovery and a significantly reduced hospital stay.

Aged↗