PubMed Health⌕ Search

Biomedical subjects

S Thompson

Publications and source records attributed to S Thompson.

At least 73 records · Page 4Linked to original sources
PubMed2000

Periconceptional vitamin use, dietary folate and occurrent neural tube defected pregnancies in a high risk population.

PURPOSE: This 5 year (1992-1997) population-based case control study was conducted to determine if supplemental or dietary folate taken during the periconceptional period reduces the risk of occurrent neural tube defect (NTD) affected pregnancies in a high risk population.METHODS: Cases were all NTD pregnancies including elective terminations, fetal deaths and live births in South Carolina. Only isolated, occurrent NTD affected pregnancies were included (N = 179). Controls (N = 288) were randomly selected from each hospital in proportion to the hospital's contribution to the total live births in the state for the previous year. All mothers were interviewed in person using a modified Centers for Disease Control and Prevention Birth Defect Risk Factor Surveillance Mother's Questionnaire and the Harvard Food Frequency Questionnaire.RESULTS: Women who used a vitamin with 0.4 mg or more of folate at least 3 times per week during the 3 months before and 3 months after conception had a lower risk of having an NTD affected pregnancy than women who took no folate supplementation at any time during pregnancy [adjusted odds ratio (AOR) = 0.42; 95% confidence interval (CI) = 0.19-0.94]; women who used a vitamin with 0.4 mg or more of folic acid for less than 3 times per week or in partial months during the 6 month periconceptional period also had a slightly lower risk of having an NTD affected pregnancy relative to women who used no folate supplementation at any time during pregnancy [AOR =.72; 95% CI = 0.41-1.30]. The risk of NTD affected pregnancy was also lower for women who daily consumed foods containing higher levels of folate: AORs were 0.36 (95% CI = 0.18-0.73), 0.72 (95% CI = 0.42-1.22), and 0.61 (95% CI 0.36-1.04) from the highest to lowest quartile of dietary folate which were 0.457-3.12 mg, 0.322-0.457 mg, and 0.236-0.322 mg respectively.CONCLUSIONS: A reduction in occurrent NTD risk associated with folate supplementation and dietary intake was observed.

Journal Article↗
PubMed2000

Intergenerational and environmental factors influencing pregnancy outcomes.

PURPOSE: Factors that relate to the mother's own course of growth and development might influence later reproductive performances. This study examines the effect of maternal birth weight and maternal height and maternal weight gain, on term-small for gestational age (SGA) and preterm delivery.METHODS: Data used for this study were from the South Carolina Pregnancy Risk Assessment Monitoring System (PRAMS) and birth certificate files for 1993-1995. Since PRAMS data were weighted to adjust for sampling probabilities, non-response and survey design, Survey Data Analysis (SUDAAN) software was used in all analyses.RESULTS: Maternal birth weight was strongly associated with term SGA (OR = 3.65; 95% CI = 1.83-7.29), but not preterm delivery among black mothers; it was associated with preterm delivery (OR = 1.86; 95% CI = 1.09-3.17), but not term-SGA for white mothers. Maternal birth weight was associated with term SGA among nonsmokers only (OR = 2.34; 95% CI = 1.33-4.11). Maternal weight gain modified the effect of height on birth outcomes. Among women with inadequate weight gain, there was a 3-fold increase in risk for term-SGA (OR = 3.06; 95% CI = 2.41-3.89) for short maternal height, but not for preterm delivery. Among women with adequate plus weight gain, the association between short maternal height and term-SGA was 2.7 (95% CI = 0.55-9.43) compared to 3.67 (95% CI = 0.1.41-9.56) between short maternal height and preterm delivery. Maternal weight gain also modified the effect of maternal height on both outcomes for black mothers and for nonsmokers only.CONCLUSIONS: Findings indicate the need for interventions directed to those women who can benefit most from appropriate targeted weight gain recommendations. Therefore, prevention methods should be implemented to encourage short stature women to gain adequate weight during pregnancy.

Journal Article↗
PubMed2000

Methionine in the multifactorial etiology of neural tube defect affected pregnancies.

PURPOSE: Research in the last 40 years has provided evidence of the role of dietary nutrients in the development of NTDs. Failure of the neural tube to close is one of the most frequent and severe fetal developmental defects. The etiology of NTDs is complex encompassing genetic, dietary, and environmental factors. With regard to diet, it appears that in humans, a combination of low levels of methionine, folate, and Vitamin B(12) may lead to the occurrence of NTDs. The purpose of this study was to explore the relationship between maternal dietary intake of methionine and the risk of having a NTD affected pregnancy.METHODS: It was hypothesized that women with high maternal dietary methionine intake were at a decreased risk for NTDs. Combinations of methionine and folate without supplements, methionine and folate with supplements, and methionine and Vitamin B(12) and NTD risk were also examined. Data from a case-control study of 170 NTD-affected pregnancies and 269 controls were provided by a CDC sponsored NTD Surveillance, Prevention, and Research Project.RESULTS: There was an approximately 30-55% reduction in NTD risk among women whose average daily dietary intake of methionine was greater than the lowest quartile of intake (>1580 mg/day). The odds ratios (95% CI) associated with the 3 quartiles of methionine intake greater than 1580 mg/day after adjusting for Kcal, race, and BMI were 0.72 (0.4030-1.288), 0.68 (0.3390-1.347), and 0.45 (0.1830-1.088).CONCLUSIONS: These findings indicate a reduction in the risk of having a NTD affected pregnancy is associated with maternal periconceptional dietary intake of methionine.

Journal Article↗
PubMed2000

Vibrio parahaemolyticus infections in the United States, 1973-1998.

Vibrio parahaemolyticus infections are associated with consumption of raw or undercooked shellfish, contaminated food, and exposure of wounds to warm seawater. Foodborne outbreaks and sporadic infections from Vibrio species in 4 Gulf Coast states are reported routinely to the Centers for Disease Control and Prevention (CDC). Between 1988 and 1997, 345 sporadic V. parahaemolyticus infections were reported: 59% were gastroenteritis, 34% were wound infections, 5% were septicemia, and 2% were from other exposures. Forty-five percent of patients suffering from these conditions were hospitalized for their infections, and 88% of persons with acute gastroenteritis reported having eaten raw oysters during the week before their illness occurred. Between 1973 and 1998, 40 outbreaks of V. parahaemolyticus infections were reported to the CDC, and these outbreaks included >1000 illnesses. Most of these outbreaks occurred during the warmer months and were attributed to seafood, particularly shellfish. The median attack rate among persons who consumed the implicated seafood was 56%. To prevent V. parahaemolyticus infections, persons should avoid consumption of raw or undercooked shellfish and exposure of wounds to seawater.

Centers for Disease Control and Prevention, U.S.↗
PubMed2000

Possible community immunity to small round structured virus gastroenteritis in a rural aboriginal community.

In April 1998 an outbreak of gastroenteritis affected visitors, but none of the Aboriginal residents, at a Territory Health Services luncheon in a rural Aboriginal community in Central Australia. The epidemiological features and identification of Small Round Structured Virus (SRSV) from two participants suggest that this was an outbreak caused by a SRSV. The attack rate in the visitors who ate or drank food at the luncheon was 73% (11 of 15). Seventeen Aboriginal residents were interviewed, none had gastroenteritis. The community potable water supply was contaminated with faecal bacteria around the time of the outbreak. No particular food could be implicated and laboratory examination of foods was not possible. It is proposed that past exposure to SRSVs may have resulted in the Aboriginal residents developing clinical immunity to infection. The process and consequences of the investigation in this community are also discussed.

Adult↗
PubMed2000

High sequence homology between human and pig CD40 with conserved binding to human CD154.

BACKGROUND: Understanding the molecular interactions between pig tissues and human immune cells is fundamental to achieving long-term pig to human xenograft survival. CD40 has been shown to be central in the interaction of T cells with many antigen-presenting cells including B cells, and dendritic cells. It has been clearly shown in vitro that human T cells can effectively recognize pig major histocompatibility complex proteins, and that various accessory molecule interactions are compatible between these species, including human CD28 with pig B7 family members (CD80/CD86). The importance of CD40 in transplantation has been established using blocking antibodies to its ligand, CD154, which prolong allograft survival in mouse and primate models. METHODS: Pig CD40 was cloned from a porcine spleen cDNA library and subsequently sequenced. Expression of pig CD40 was detected by flow cytometry using soluble human CD154 (hCD154-Ig). Results. Comparison of the derived amino acid sequence of pig with human shows 74% identity. Significantly, there is conservation between pig and human at 5 residues shown by mutagenesis studies to be essential for binding of human CD40 to CD154. hCD154Ckappa was shown to bind pig B cell lines and a proportion of human and pig lymphocytes and further confirmed by staining of COS cells transfected with pig CD40. Conclusions. Recipient human cells bearing CD154 will, therefore, be able to bind donor pig CD40, and these interactions might modulate effector functions and hence influence xenograft survival. Further investigation is necessary to ascertain the exact nature of these interactions and their implications for xenograft survival.

Amino Acid Sequence↗
PubMed2000

Combined protocol for the analysis of polycyclic aromatic hydrocarbons (PAHs) and polychlorobiphenyls (PCBx) from sediments using focussed microwave assisted (FMW) extraction at atmospheric pressure.

A microwave-assisted protocol has been developed using focussed microwaves at atmospheric pressure for the extraction of PAHs and PCBs from sediments. It combines extraction and purification assisted by microwaves. This protocol has been applied to the quantification of 12 individual PAHs, 8 individual PCBs and 8 PCB coeluted mixtures from two Standard Reference Materials and one natural sediment. The results for both classes of compounds (PAHs and PCBs) are good in terms of recoveries, which are always greater than 70% and in most cases around 100%. The reproducibility is also good with coefficients of variation below 10% in most cases. This protocol has the great advantage of saving time, the time dedicated to the preparation / extraction assisted by microwaves being reduced to less than half an hour.

Atmospheric Pressure↗
PubMed2000

Project GRAD: two-year outcomes of a randomized controlled physical activity intervention among young adults. Graduate Ready for Activity Daily.

INTRODUCTION: Project Graduate Ready for Activity Daily evaluated a program to promote physical activity through the transition of university graduation in a randomized controlled trial. METHODS: Three hundred thirty-eight university seniors participated in either a cognitive-behavioral intervention course or a knowledge-oriented general health course during the semester before graduation. Behaviorally oriented phone and mail follow-up was delivered to the intervention group for 18 months. Physical activity outcomes and mediating variables were assessed at baseline, 1 and 2 years (93% retention rate). RESULTS: There were no significant intervention effects on physical activity outcomes at 2 years for either men or women. Experiential and behavioral processes of change were significantly improved for intervention women over 2 years. CONCLUSIONS: Despite excellent participation in a theoretically based, well-attended intervention, few long-term effects on physical activity or its mediators were found. Additional research is needed to determine optimal interventions for physical activity and to validate or alter current behavior change theory.

Adult↗
PubMed2000

Production of cloned pigs from in vitro systems.

Here we describe a procedure for cloning pigs by the use of in vitro culture systems. Four healthy male piglets from two litters were born following nuclear transfer of cultured somatic cells and subsequent embryo transfer. The initiation of five additional pregnancies demonstrates the reproducibility of this procedure. Its important features include extended in vitro culture of fetal cells preceding nuclear transfer, as well as in vitro maturation and activation of oocytes and in vitro embryo culture. The cell culture and nuclear transfer techniques described here should allow the use of genetic modification procedures to produce tissues and organs from cloned pigs with reduced immunogenicity for use in xenotransplantation.

Animals↗
PubMed2000

Loss of Cmk1 Ca(2+)-calmodulin-dependent protein kinase in yeast results in constitutive weak organic acid resistance, associated with a post-transcriptional activation of the Pdr12 ATP-binding cassette transporter.

Yeast cells display an adaptive stress response when exposed to weak organic acids at low pH. This adaptation is important in the spoilage of preserved foods, as it allows growth in the presence of weak acid food preservatives. In Saccharomyces cerevisiae, this stress response leads to strong induction of the Pdr12 ATP-binding cassette (ABC) transporter, which catalyses the active efflux of weak acid anions from the cytosol of adapted cells. S. cerevisiae cells lacking the Cmk1 isoform of Ca2+-calmodulin-dependent protein kinase are intrinsically resistant to weak acid stress, in that they do not need to spend a long adaptive period in lag phase before resuming growth after exposure to this stress. This resistance of the cmk1 mutant is Pdr12 dependent and, unlike with wild-type S. cerevisiae, cmk1 cells are capable of performing Pdr12-specific functions such as energy-dependent cellular extrusion of fluorescein and benzoate. However, they have neither higher PDR12 gene promoter activity nor higher Pdr12 protein levels. The increased Pdr12 activity in cmk1 cells is therefore caused by Cmk1 exerting a negative post-transcriptional influence over the activity of the Pdr12 ABC transporter, a transporter protein that is constitutively expressed in low-pH yeast cultures. This is the first preliminary evidence that shows a protein kinase, either directly or indirectly, regulating the activity of a yeast ABC transporter.

ATP-Binding Cassette Transporters↗
PubMed2000

Service use over time and achievement of stable housing in a mentally ill homeless population.

OBJECTIVE: Service use among clients of a multiservice agency serving homeless persons with severe mental illness was examined to determine whether patterns of service use reflected two stages in an adaptation of the transtheoretical model of change. In the adapted model, change occurs in five stages-pre-engagement, contemplation, engagement, the strategic moment, and consolidation. It was hypothesized that rates of service use would be highest immediately after clients obtained housing (the strategic moment) and would decrease in the months afterward (consolidation stage), with the greatest decreases occurring immediately after housing was obtained. METHODS: Service use data were collected for two groups: a housed group of 58 clients who had obtained and sustained stable housing for at least 24 consecutive months at the time of sampling and an unhoused group of 55 clients who were matched with the housed clients on month of service entry. Total service use and use of three service types-a drop-in center, counseling, and health services-were examined to test the hypotheses. It was hypothesized that use of services by the unhoused group would show a consistent linear decline rather than a two-stage decline. Linear spline regression using bootstrap sampling methods was used to fit service use data for both groups. RESULTS: The two-stage solution significantly modeled the patterns of service use by the housed but not the unhoused clients, supporting the hypotheses. For the housed group, use of the drop-in center and counseling fit the model, and use of health services did not. CONCLUSIONS: The results provide limited support for the hypothesized five-stage model for achieving change.

Adult↗
PubMed2000

Silent lacunar lesions detected by magnetic resonance imaging of children with brain tumors: a late sequela of therapy.

BACKGROUND: Cerebral lacunes, which generally appear on magnetic resonance imaging as foci of white matter loss, usually occur in adults after ischemic infarcts. We report the development of lacunes in children after therapy for brain tumors. PATIENTS AND METHODS: We reviewed the clinical characteristics and radiologic studies of 524 consecutive children with brain tumors treated over a 10-year period. We documented the neuropsychologic findings associated with lacunes and the factors predictive of lacunar development. RESULTS: Lacunes developed in none of the 103 patients observed or treated with surgery alone. Twenty-five of the 421 patients treated with chemotherapy or radiation therapy or both had lacunes. Patients were a median of 4.5 years old at the time of both diagnosis (range, 0.3 to 19.8 years) and radiotherapy (range, 1.5 to 20 years). Fourteen patients were treated with craniospinal irradiation, and 11 were treated with local radiotherapy. The median time from radiotherapy to the appearance of lacunes was 2.01 years (range, 0.26 to 5.7 years). For all patients, lacunes were an incidental finding with no corresponding clinical deficits. The factor most predictive of lacunar development was age less than 5 years at the time of radiotherapy (P =.010). There was no significant difference in estimated decline in intelligence quotient scores between patients with lacunes and age and diagnosis-matched controls. CONCLUSION: Lacunes may be caused by therapy-induced vasculopathy in children with brain tumors, with the most significant predictor being age less than 5 years at the time of radiotherapy.

Adolescent↗
PubMed2000

Decline in prevalence of neural tube defects in a high-risk region of the United States.

OBJECTIVES: To conduct surveillance for neural tube defects (NTDs) in a high-risk region of the United States and to prevent occurrence and recurrence of NTDs through the periconceptional use of folic acid supplements. DESIGN: Active and passive methods were used for surveillance of NTD-affected pregnancies and births during a 6-year period (October 1992-September 1998). Individual genetic counseling was used to prevent NTD recurrences and a public awareness campaign was used to reduce NTD occurrences. SETTING: State of South Carolina. PATIENTS: All cases of spina bifida, anencephaly, and encephalocele identified among 278 122 live births and fetal deaths to South Carolina residents during 1992-1998 were included. MAIN OUTCOME MEASURE: Changes in occurrence and recurrence rates during a 6-year period. RESULTS: Over the 6 years of surveillance, the prevalence rates for NTDs decreased from 1.89 to.95 cases per 1000 live births and fetal deaths. The prevalence decrease is explained primarily by a decrease in cases of spina bifida. Isolated NTDs accounted for 297/360 (82%) NTDs and 63/360 (18%) had at least 1 other structural anomaly. Females predominated among isolated NTDs but the sex distribution was equal among NTD cases with other anomalies. Prevalence rates for whites (1.48 cases per 1000 live births and fetal deaths) were higher than rates for blacks (.87 cases per 1000 live births and fetal deaths). There were no NTD recurrences in 113 subsequent pregnancies to mothers of infants with isolated NTDs who took periconceptional folic acid. The rate of periconceptional folic acid use among women of childbearing years increased from 8% to 35% during the 6-year project period. CONCLUSION: The prevalence of NTDs in a high-risk region has declined coincident with the increased periconceptional use of folic acid supplements among women of childbearing age.neural tube defects, high-risk region, birth defects, folic acid, spina bifida, anencephaly, encephalocele.

Adolescent↗
PubMed2000

Etiology of travelers' diarrhea on a Caribbean island.

BACKGROUND: Between December 6, 1994 and March 10, 1996, a study of the etiology of diarrhea was carried out among 332 travelers to five all-inclusive hotels in Negril, Jamaica. METHODS: Stool specimens were collected and sent to Montego Bay for laboratory analysis. Escherichia coli strains isolated at the Jamaican laboratory were sent to Houston for toxin testing. RESULTS: A recognized enteropathogen was found in 118 of the 332 (35.5%) cases. Enterotoxigenic E. coli (ETEC) were the most commonly identified pathogen (87/332; 26.2%) followed by Salmonella (4.2%) and Shigella (4.2%). Clustering of etiologically defined cases was studied at each hotel. A cluster was defined as 2 or more cases with the same pathogen identified in the same hotel within 7 days. In the 3 hotels with the highest number of cases of diarrhea, enteropathogens were part of a cluster in 65 of 99 cases (65.7%) of diarrhea of which an etiologic agent was identified. In the other 2 hotels, only 4 of 20 cases (20%) occurred in clusters. CONCLUSIONS: A total of 25 clusters of travelers' diarrhea cases was detected at the five hotels during the study period. Seventeen of 25 (68%) ETEC isolations occurred as part of a clustering of diarrhea cases. The largest outbreak of pathogen-identified diarrhea consisted of 7 cases of ETEC producing both heat-stable and heat-labile enterotoxins. In the Jamaican hotels with all inclusive meal packages most diarrhea cases occurred as small clusters, presumably as the result of foodborne outbreaks.

Campylobacter Infections↗
PubMed2000

Relationship between feeding practices and weanling diarrhoea in northeast Thailand.

Diarrhoea is a major public health problem in Thailand. During November 1998-January 1999, a cross-sectional survey and a nested qualitative study were conducted to understand the relationship between feeding practices and weanling diarrhoea, and to describe the related local beliefs and practices in a subdistrict of northeast Thailand. A cluster-sampling method was used for selecting 156 weanlings aged 3-24 months. A structured interview was conducted with the main caregivers of these weanlings. The questionnaire used for the interview included items about feeding practices and diarrhoea-history of the weanlings in 2 months prior to the interview. Seven focus-group discussions with an opportunistic sample of the caregivers were held in the villages. A series of vignettes and unstructured questions were used for eliciting the local beliefs about weanling diarrhoea and its causes. Thirty-six (23%) of the 156 weanlings had diarrhoea in 2 months prior to the interview. The factors that were significantly related to reported weanling diarrhoea included consumption of unboiled water by weanlings (OR = 10, p = 0.03), not covering perishable foods (OR = 3, p = 0.02), and washing feeding utensils of weanlings without dishwashing detergent (OR = 3.1, p = 0.02), 'Su' and 'tongsia'--two common local terms--were used for describing different types of weanling diarrhoea. Many caregivers considered 'su' a natural occurrence in a child's development. The results suggest that some poor feeding practices may contribute to the higher risk of weanling diarrhoea in northeast Thailand. Some local beliefs about weanling diarrhoea may mask the true causes, and mislead messages about its prevention.

Adolescent↗
PubMed2000

Short-term prognostic value of lipid measurements in patients with angina pectoris. The ECAT Angina Pectoris Study Group: European Concerted Action on Thrombosis and Disabilities.

We studied the role of various markers of lipid metabolism, hemostasis and inflammation in a two year follow-up of 3,000 patients with angina pectoris, during which time 106 patients experienced myocardial infarction or sudden coronary death. Low levels of high density lipoprotein (HDL) cholesterol and of apolipoprotein (apo) A-I were most strongly associated with increased coronary risk. The relative risk per standard deviation increase was 0.68 for HDL cholesterol (95% confidence interval 0.55 to 0.84) and 0.66 for apoA-I (0.54 to 0.81). These associations were independent of other coronary risk factors, other lipid measurements, hemostatic factors, and C-reactive protein (CRP). The associations of total and LDL cholesterol, triglycerides, apoB, and lipoprotein(a) with coronary events were not independent of HDL cholesterol or hemostatic factors. We conclude that HDL cholesterol or apoA-I, hemostatic risk factors, and CRP are important prognostic markers of coronary events in secondary prevention.

Angina Pectoris↗