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Biomedical subjects

M Wilcox

Publications and source records attributed to M Wilcox.

At least 37 records · Page 2Linked to original sources
PubMed1997

Back to the future: sweatshop conditions on the Mexico-U.S. border. II. Occupational health impact of maquiladora industrial activity.

Present working conditions in one of the most active areas of the maquiladora system along the Mexico-U.S. border are reminiscent of nineteenth-century U.S. sweatshops. The organization of production is Tayloristic and authoritarian, with detailed division of labor, repetitive simple tasks, and piecework wages. Modern participative management styles are not apparent in the maquiladora setting. This study consists of two separate but interrelated surveys conducted in 1992, one of community leaders and this one of workers in maquiladora enterprises in the towns of Matamoros and Reynosa, Mexico. The community survey evaluated the economic and psychosocial impact of the maquiladora enterprise and was conducted simultaneously to the workers' survey and in the same Mexican towns where the workers lived and worked. The community leaders acknowledged the employment opportunities that maquiladora factories had brought to the region but believed them to have high environmental and psychosocial costs. For the occupational component, a community-based survey of 267 maquiladora workers was conducted. participants were chosen with more than a year seniority in the industry and living in the two Mexican cities surveyed. They responded to an extensive questionnaire given by trained canvassers. The workers' survey found evidence that maquiladora workers (81% female) report symptoms from musculoskeletal disorders related to working conditions. Acute health effects compatible with chemical exposures were also identified. Prevalence of symptoms was correlated with increasing duration of exposure to ergonomic risk factors and qualitative chemical exposure indexes. Other chronic disease was not apparent. The survey demonstrated inequalities in salary, working hours, and safety training between the two communities. Matamoros workers are substantially better paid and work fewer hours per week than Reynosa workers. Most hazards reported in the worker's survey have been well studied in the general occupational health literature with respect to adverse health effects. Therefore, it is recommended that hazard surveillance studies would be more useful towards the goal of prevention than further etiologic studies. Specific recommendations on policy and remediation interventions are also made.

Adult↗
PubMed1996

Is macrosomia associated with poor glycaemic control in diabetic pregnancy?

The study aimed to determine the influence of glucose control during pregnancy on the incidence of macrosomia in the infants of mothers with insulin-dependent diabetes. The prevalence of macrosomia was determined in pregnancies of all such women attending the City Hospital Nottingham, between July 1987 and July 1993, where it is policy for diabetic patients to aim during pregnancy for preprandial capillary glucose levels of less than 6.0 mmol I-1, and postprandial glucose levels of less than 8.0 mmol I-1. Macrosomia was defined as a birthweight greater than 90th centile using a computer model which takes into account all the major determinants of birthweight. Twelve of 29 infants were macrosomic, which is greater than expected (p < 0.01). During pregnancy there was no difference in mean seven point glucose profiles between those mothers with normal weight babies and those with macrosomia, but fructosamine levels at booking were significantly higher in the latter 2.5 (1.9-2.9) vs 2.2 (1.2-3.0); p < 0.05. These data confirm other studies and suggest that the incidence of macrosomia may be reduced by tighter control of diabetes at conception and in the first trimester, but to a lesser extent during later pregnancy.

Blood Glucose↗
PubMed1996

Estimating the date of confinement: ultrasonographic biometry versus certain menstrual dates.

OBJECTIVE: Our purpose was to evaluate the clinical implications of current pregnancy dating policies in a population where routine ultrasonography is performed in the first half of pregnancy. STUDY DESIGN: A total of 34,249 computer files of singleton pregnancies that had both "certain" menstrual dates and ultrasonographic biometry were retrieved from the East Midlands Obstetric Database. The estimated dates of delivery were calculated by five different methods: menstrual dates alone, ultrasonography alone, or a combination of both with menstrual dates used if the discrepancy with the ultrasonography dates was within 7, 10, or 14 days, respectively. The accuracy of each method in predicting the actual date of delivery was calculated. Differences among methods were evaluated with nonparametric tests. RESULTS: Compared with use of certain menstrual dates, ultrasonographic dating led to a 70% reduction in the number of pregnancies considered postterm. Delivery occurred within +/- 7 days of the estimated date of confinement in 49.5% cases when menstrual dates alone were used and in 55.2% if ultrasonography alone was used; for +/- 10 days, the corresponding figures were 64.1% and 70.3%. Scan dating alone was significantly better in predicting the actual date of delivery than any of the dating policies taking menstrual dates alone or in combination with ultrasonography. CONCLUSIONS: Even if menstrual dates are considered "certain," there is no advantage in taking them into consideration for calculating the expected date of delivery if a dating ultrasonography result is available. Dating by ultrasonographic biometry in the first half of pregnancy results in a more accurate prediction of the delivery date than using menstrual data alone or in combination with ultrasonography.

Biometry↗
PubMed1996

Improved intrapartum surveillance with PR interval analysis of the fetal electrocardiogram: a randomized trial showing a reduction in fetal blood sampling.

OBJECTIVE: Our goal was to test the hypothesis that the addition of fetal electrocardiogram time-interval analysis to conventional electronic fetal monitoring would significantly reduce the number of cases requiring fetal scalp blood sampling without an increase in adverse outcome. STUDY DESIGN: A randomized prospective trial was performed in 214 women with high-risk labor. RESULTS: There was a significant reduction in the number of cases that had fetal blood sampling performed in the fetal electrocardiogram plus electronic fetal monitoring group (risk ratio for electronic fetal monitoring alone 3.53; p < 0.01, 95% confidence interval 1.39 to 8.95). The fetal blood samplings performed in the electronic fetal monitoring alone group were less likely to be abnormal (pH < 7.25, base excess < -8.0) than those performed in the fetal electrocardiogram plus electronic fetal monitoring group (risk ratio for electronic fetal monitoring alone 0.62, p = 0.05, 95% confidence interval 0.35 to 1.10). There was a trend of more infants with an arterial umbilical pH < 7.15 and a base excess less than -8.0 mmol/L at birth being unsuspected and more instrumental deliveries for presumed fetal distress being performed in the electronic fetal monitoring alone than in the fetal electrocardiogram plus electronic fetal monitoring group. CONCLUSION: The addition of fetal electrocardiogram analysis to conventional electronic fetal monitoring during labor can reduce significantly the number of parturients undergoing fetal scalp blood sampling and can simultaneously increase its efficiency without an increase in adverse outcome.

Acidosis↗
PubMed1996

Centration and fixation of silicone intraocular lenses: clinicopathological findings in human autopsy eyes.

PURPOSE: To analyze centration and fixation of three-piece and one-piece silicone intraocular lenses (IOLs) in human autopsy eyes. SETTING: Center for Intraocular Lens Research, Medical University of South Carolina, Charleston. METHODS: Thirty eyes among those submitted to the center between 1986 and 1994 were evaluated. The globes were sectioned at the equatorial plane and photographed from a posterior view. Gross examination was performed to determine IOL type, fixation, centration, and additional pathology. The results were compared with those of a control group of autopsy eyes implanted with one-piece and three-piece poly(methyl methacrylate) (PMMA) IOLs. The control group matched the silicone group in patient age, fixation site, and duration of implantation. RESULTS: Twenty-three eyes (79.3%) had three-piece silicone IOLs and 7 eyes (20.7%), one-piece plate IOLs. Average patient age in the three-piece group was 77.3 years +/- 6.7 (SD) and in the one-piece group, 74.3 +/- 3.8 years. The 30 IOLs were symmetrically fixated in the bag. Average decentration of the three-piece and one-piece IOLs did not differ significantly, 0.37 +/- 0.31 mm and 0.26 +/- 0.13 mm, respectively (P = .37). There was also no significant difference in decentration between the silicone groups and the PMMA groups (P = .93). CONCLUSION: Centration and fixation of silicone IOLs were equivalent to those of standard PMMA IOLs.

Aged↗
PubMed1996

Relationship of study participation to health-related behaviors.

This study explores the ways in which clinical trial participation influences a person's health and health-promoting behaviors. Active study subjects with a minimum of 4 months' clinical trial participation were mailed a nurse-developed questionnaire. Seventy-three percent of the targeted group returned the survey by the deadline. The majority of respondents made changes toward better health. Diet modification, initiation of an exercise program, and smoking cessation were the changes cited most frequently. The study team was found to be influential in promotion of health. The nurse, the pivotal member of the team, provided subjects with the most health-related information. Most respondents believed they had enough information to change behaviors detrimental to health.

Clinical Trials as Topic↗
PubMed1995

Factors determining specificity of signal transduction by G-protein-coupled receptors. Regulation of signal transfer from receptor to G-protein.

Among subfamilies of G-protein-coupled receptors, agonists initiate several cell signaling events depending on the receptor subtype (R) and the type of G-protein (G) or effector molecule (E) expressed in a particular cell. Determinants of signaling specificity/efficiency may operate at the R-G interface, where events are influenced by cell architecture or accessory proteins found in the receptor's microenvironment. This issue was addressed by characterizing signal transfer from R to G following stable expression of the alpha 2A/D adrenergic receptor in two different membrane environments (NIH-3T3 fibroblasts and the pheochromocytoma cell line, PC-12). Receptor coupling to endogenous G-proteins in both cell types was eliminated by pertussis toxin pretreatment and R-G signal transfer restored by reconstitution of cell membranes with purified brain G-protein. Thus, the receptor has access to the same population of G-proteins in the two different environments. In this signal restoration assay, agonist-induced activation of G was 3-9-fold greater in PC-12 as compared with NIH-3T3 alpha 2-adrenergic receptor transfectants. The cell-specific differences in signal transfer were observed over a range of receptor densities or G-protein concentration. The augmented signal transfer in PC-12 versus NIH-3T3 transfectants occurred despite a 2-3-fold lower level of receptors existing in the R-G-coupled state (high affinity, guanyl-5'-yl imidodiphosphate-sensitive agonist binding), suggesting the existence of other membrane factors that influence the nucleotide binding behavior of G-protein in the two cell types. Detergent extraction of PC-12 but not NIH-3T3 membranes yielded a heat-sensitive, macromolecular entity that increased 35S-labeled guanosine 5'-O-(thiotriphosphate) binding to brain G-protein in a concentration-dependent manner. These data indicate that the transfer of signal from R to G is regulated by a cell type-specific, membrane-associated protein that enhances the agonist-induced activation of G.

3T3 Cells↗
PubMed1995

Analysis of 100 explanted one-piece and three-piece silicone intraocular lenses.

PURPOSE: The authors analyzed incidence and types of complications seen after implantation of silicone posterior chamber intraocular lenses (PC IOLs). These data were compared with those obtained in previous studies with standard polymethylmethacrylate IOLs. METHODS: Data from the laboratory database were collected on 100 explanted silicone IOLs submitted to the Center for Intraocular Lens Research from 1986 to 1994. RESULTS: Of the 100 IOLs, 63 were three-piece designs with polypropylene loops and 37 were one-piece plate lenses. The two most important reasons for explantation were IOL decentration (42.0%) and inflammation (27.7%). There was no significant difference for the reasons of explantations between one- and three piece IOLs (P > 0.1). Intraocular lenses that had been removed due to inflammatory reactions had a significantly longer implant duration (19.2 +/- 18.9 months) than lenses that were explanted because of decentration (9.19 +/- 12.1 months) (P = 0.018). CONCLUSIONS: The results presented here showed that there is no substantial difference between these IOLs and polymethylmethacrylate lenses in terms of reasons for explantation. The authors' data suggest that clinical outcome is not as dependent on the type of lens selected as it is on the quality of surgery. The key to good results is the use of "capsular surgery," namely techniques that ensure secure in-the-bag IOL fixation.

Cataract Extraction↗
PubMed1995

An adjustable fetal weight standard.

The monitoring of fetal weight is an important aspect of antenatal care. To construct an individually adjustable standard, we developed a model to link the predicted birth weight to a fetal weight curve which outlines how this weight is to be reached in an uncomplicated pregnancy. A formula was derived which describes the median fetal weight at each gestation as a proportion of the optimal term weight, and also defines the 90th and 10th centile curves as normal limits. We analyzed a birth weight database of 38,114 singleton, routine ultrasound-dated pregnancies resulting in term deliveries. By stepwise multiple regression analysis, we derived coefficients for the factors that act as variables on term birth weight in our population. Apart from gestational age and sex, the maternal height, weight at first visit, ethnic group, parity and smoking all have significant and independent effects on birth weight. The variation due to ethnic group appears to be physiological in this population. Smoking is associated with a reduction in birth weight, which is independent of maternal physique and related to the number of cigarettes per day as reported at the first visit. We have developed a software program which calculates, on the basis of pregnancy variables entered at the first visit, an adjusted normal range for fetal size. This can be printed out as a chart and used for antenatal surveillance of growth.

Birth Weight↗
PubMed1994

Back to the future: sweatshop conditions on the Mexico-U.S. border. I. Community health impact of maquiladora industrial activity.

Present working conditions in one of the most active areas of the maquiladora system along the Mexico-U.S. border are reminiscent of nineteenth-century U.S. sweatshops. This conclusion was reached after evaluating two separate but interrelated surveys among Mexican nationals living near the Mexico-U.S. border, one of community leaders (Paper I), and one of workers in maquiladora enterprises in the towns of Matamoros and Reynosa, Mexico (Paper II). Paper I evaluates the results of the community leaders' survey. Criteria for selection of the leaders were: level of responsibility in the community; knowledge of the industry in the region, and length of residence in the area (more than 3 years). Representatives from government, maquiladora industry management, labor union leadership, labor union activists, and community improvement activists were interviewed. Structured questionnaires with opportunities for open-ended answers were used by trained Spanish speaking interviewers. The questions covered community demographics, health care structures, governance of the region, knowledge of working conditions, and knowledge of environmental impact on the region and the community. Community leaders were ambivalent on the purported benefits of the development of these types of industries in their communities. A substantial majority (21 of 25) thought that the maquiladoras brought few positive developments, other than creating jobs. Serious concerns about overextending weak social infrastructures and about environmental deterioration were voiced. Immediate (preventive) measures appear necessary to develop community infrastructures and to protect environmental health.

Community Health Services↗
PubMed1994

An unusual extrauterine variant of adenosarcoma with multiple recurrences over 16 years.

An unusual extrauterine (pelvic) variant of adenosarcoma is presented. A benign-appearing epithelium resembling fallopian tube epithelium is integrally mixed with malignant stroma that in all areas sampled is low-grade leiomyosarcoma. The tumor has behaved as a low-grade malignancy with four local recurrences over a 16-year period. Extrauterine adenosarcomas have rarely been reported in the literature; and one in which the stromal component is histologically all of smooth muscle differentiation is more unusual.

Adenosarcoma↗