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Biomedical subjects

M Wilson

Publications and source records attributed to M Wilson.

At least 145 records · Page 8Linked to original sources
PubMed2001

Primary care physician job satisfaction and turnover.

OBJECTIVE: To examine the relationship of personal characteristics, organizational characteristics, and overall job satisfaction to primary care physician (PCP) turnover. SUBJECTS AND METHODS: A cohort of 507 postresident, nonfederally employed PCPs younger than 45 years of age, who completed their medical training between 1982 and 1985, participated in national surveys in 1987 and 1991. Psychological, economic, and sociological theories and constructs provided a conceptual framework. Primary care physician personal, organizational, and overall job satisfaction variables from 1987 were considered independent variables. Turnover-related responses from 1991 were dependent variables. Bivariate and multivariate analyses were conducted. RESULTS: More than half (55%) of all PCPs in the cohort left at least 1 practice between 1987 and 1991. Twenty percent of the cohort left 2 employers. PCPs dissatisfied in 1987 were 2.38 times more likely to leave (P < .001). Primary care physicians who believed that third-party payer influence would decrease in 5 years were 1.29 times more likely to leave (P < .03). Non-board certified PCPs were 1.3 times more likely to leave (P < .003). Primary care physicians who believed that standardized protocols were overused were 1.18 times more likely to leave (P < .05). Specialty, gender, age, race, and practice setting were not associated with PCP turnover. CONCLUSIONS: Turnover was an important phenomenon among PCPs in this cohort. The results of this study could enable policy makers, managed care organizations, researchers, and others to better understand the relationship between job satisfaction and turnover.

Adult↗
PubMed2001

Pituitary-adrenal function in uncomplicated falciparum malaria.

To investigate pituitary-adrenal function in acute uncomplicated falciparum malaria, we performed an overnight dexamethasone suppression test in 13 Vietnamese adults with acute malaria and 6 healthy controls. After blood samples were taken for serum cortisol and plasma ACTH at 23.00 hours on the admission day, 1 mg dexamethasone was given and further samples were taken at 08.00, 16.00 and 23.00 hours the next day. The patients received conventional antimalarial and supportive treatment. Baseline plasma ACTH concentrations in the patients [3.9 (0.2-41.2) pmol/l] and controls [3.4 (1.1-4.3) pmol/l] were similar (p=0.51), and exhibited a similar fall after dexamethasone to 0.6 (0.2-2.5) and 0.9 (0.7-1.6) pmol/l at 08.00 hours respectively (p<0.03 vs 23.00 hour values). Serum cortisol levels before dexamethasone were higher in the patients than in the controls [456 (102-821) vs 145 (64-183) nmol/l respectively; p=0.007] and the overnight fall was less in the patients [208 (26-340) and 23 (15-46) nmol/l at 08.00 hours respectively; p<0.001 vs 23.00 hour values and between groups]. Between 08.00 and 23.00 hours, plasma ACTH and serum cortisol remained suppressed in the controls. In the patients, the serum cortisol continued to fall progressively towards control values. These data suggest that there is a raised set point for cortisol inhibition of ACTH secretion but normal corticotrophin responsiveness to dexamethasone in uncomplicated malaria. A raised serum cortisol after dexamethasone in the patients might reflect the combination of a prolonged cortisol half-life and the stimulatory effects of cytokines on the adrenal cortex, with a consequent protective effect against complications such as hypoglycemia.

Adrenal Glands↗
PubMed2000

Enhanced surveillance of HIV infections in New Zealand, 1996-1998.

AIM: To improve understanding of the HIV epidemic in New Zealand through use of an enhanced voluntary reporting system for new diagnoses of HIV. METHODS: Routine reporting of new HIV diagnoses by the two laboratories that perform confirmatory HIV antibody testing, to the Department of Health and later to the AIDS Epidemiology Group, has been in place since 1985. From January 1996, this was supplemented by a questionnaire about demographic characteristics and circumstances of HIV exposure sent to clinicians requesting the HIV test. RESULTS: From January 1996 to December 1998, 260 new diagnoses of HIV were reported (205 males, 55 females) and extra information was obtained from clinicians for 253 (97.3%) people. HIV diagnosis rate was highest for 'other' ethnicity and similar for European, Maori and Pacific Island ethnic groups. Sexual intercourse between men was the commonest mode of infection (43.5%), followed by heterosexual intercourse (40.0%) and injecting drug use (2.7%). Places of infection were New Zealand (38.5%), Australia (7.7%), 'other' overseas (45.4%) and unknown (8.5%). Heterosexual infections were acquired through contact with a person in or from a high prevalence area (mainly in Africa or Asia) for 86.7% of males and 68.2% of females. Second generation heterosexual transmission was rare. CONCLUSIONS: Introduction of an enhanced surveillance system has been successful. Results confirm continuing spread of HIV in New Zealand amongst men who have sex with men, and suggest low levels of heterosexual and injecting drug use transmission in New Zealand. Of major importance in the occurrence of heterosexual infection is the role of imported HIV.

Adolescent↗
PubMed2000

Structural studies of microcosm dental plaques grown under different nutritional conditions.

The aim of this study was to investigate the structure of intact oral biofilms using confocal laser scanning microscopy (CLSM). Mixed-species biofilms were grown on enamel discs in a constant depth film fermentor. The biofilms were fed with a mucin-containing artificial saliva with or without sucrose supplementation. Biofilms were examined using a Wild-Leitz CLSM, operating in reflected light mode. The microstructure of non-supplemented biofilms was revealed to be complex, with stacks of bacteria developing over time, separated by clear channels. Sucrose-supplemented biofilms appeared to colonise the substratum more rapidly. The results of this study have shown that using CLSM it is possible to examine the structure of oral biofilms grown under conditions similar to those which would exist in vivo.

Biofilms↗
PubMed2000

Detecting mannosidase activities using ribonuclease B and matrix-assisted laser desorption/ionization-time of flight mass spectrometry.

Ribonuclease (RNase) B incubated with purified enzymes, whole bacterial cultures, or their separated components-cells and supernates-have been directly analyzed by matrix-assisted laser desorption/ionization-time of flight mass spectrometry (MALDI-ToF) to detect exomannosidases and to evaluate their specificities and location. Enzymatic cleavage was monitored by observing changes in RNase B glycoform population. Thus a nonspecific alpha-(1 --> 2)-mannosidase activity converts the glycoprotein to its Man(5) form, identifiable by its mass of 14,899 [M + H](+); this species subsequently is converted, by the actions of alpha-(1 --> 3) and alpha-(1 --> 6)-mannosidases, to the Man(1) form via Man(4), Man(3), and Man(2). The Man(1) glycoform (which is readily isolated) has then similarly been used for identifying beta-(1 --> 4)-mannosidase and the derived Man(0) form has served in turn as a natural substrate for beta-(1 --> 4) N-acetylglucosaminidase producing a species possessing a single asparagine-linked GlcNAc residue (mass 13,886). Mannose liberated from the actions of mannosidases can, if desired, be quantified by, for example, chromatography. The actions and specificities of endoglycosidases such as a peptide-N-glycosidase F (PNGase F) and of endo-N-acetlyglucosaminidases (e.g., endo-F and endo-H), which respectively cleave between the GlcNAc&bond;Asn and GlcNAc&bond;GlcNAc bonds of N-linked glycoproteins, are also demonstrable by MALDI-ToF analysis of RNase B (and derived products). From these digests the completely deglycosylated polypeptide corresponding to RNase A in which Asn has been converted to Asp (mass 13,684) and a species corresponding to RNase A + GlcNAc (mass 13,886) are produced, together with their corresponding free oligosaccharides which are amenable to analysis by both MALDI-ToF and by HPLC.

Amidohydrolases↗
PubMed2000

Oral contraceptives and fatal pulmonary embolism.

In a national case-control study of fatal pulmonary embolism in New Zealand women of childbearing age, we estimated that current users of combined oral contraceptives had a relative risk of 9.6 (95% CI 3.1-29.1). From national distribution data, the absolute risk of death from pulmonary embolism in current users was estimated to be 10.5 per million woman-years.

Adult↗
PubMed2000

Imperforate anus in Feingold syndrome.

A father and daughter had the characteristic findings of Feingold syndrome including microcephaly, short palpebral fissures, brachydactyly with clinodactyly of fifth fingers, and bilateral syndactyly of second to third and fourth to fifth toes. The infant presented with long-gap esophageal atresia without fistula (type A). Her father, who had short stature and learning disabilities, had congenital imperforate anus with a recto-vesical fistula. This is the first report of distal intestinal atresia in Feingold syndrome.

Abnormalities, Multiple↗
PubMed2000

Preventing congenital toxoplasmosis.

SCOPE OF THE PROBLEM: Toxoplasmosis is caused by infection with the protozoan parasite Toxoplasma gondii. Acute infections in pregnant women can be transmitted to the fetus and cause severe illness (e.g., mental retardation, blindness, and epilepsy). An estimated 400-4,000 cases of congenital toxoplasmosis occur each year in the United States. Of the 750 deaths attributed to toxoplasmosis each year, 375 (50%) are believed to be caused by eating contaminated meat, making toxoplasmosis the third leading cause of foodborne deaths in this country. ETIOLOGIC FACTORS: Toxoplasma can be transmitted to humans by three principal routes: a) ingestion of raw or inadequately cooked infected meat; b) ingestion of oocysts, an environmentally resistant form of the organism that cats pass in their feces, with exposure of humans occurring through exposure to cat litter or soil (e.g., from gardening or unwashed fruits or vegetables); and c) a newly infected pregnant woman passing the infection to her unborn fetus. RECOMMENDATIONSFOR PREVENTION: Toxoplasma infection can be prevented in large part by a) cooking meat to a safe temperature (i.e., one sufficient to kill Toxoplasma); b) peeling or thoroughly washing fruits and vegetables before eating; c) cleaning cooking surfaces and utensils afterthey have contacted raw meat, poultry, seafood, or unwashed fruits or vegetables; d) pregnant women avoiding changing cat litter or, if no one else is available to change the cat litter, using gloves, then washing hands thoroughly; and e) not feeding raw or undercooked meat to cats and keeping cats inside to prevent acquisition of Toxoplasma by eating infected prey. RESEARCH AGENDA: Priorities for research were discussed at a national workshop sponsored by CDC in September 1998 and include a) improving estimates of the burden of toxoplasmosis, b) improving diagnostic tests to determine when a person becomes infected with Toxoplasma, and c) determining the applicability of national screening programs. CONCLUSION: Many cases of congenital toxoplasmosis can be prevented. Specific measures can be taken by women and their health-care providers to decrease the risk for infection during pregnancy and prevent severe illness in newborn infants.

Female↗
PubMed2000

Source identification of underground fuel spills by solid-phase microextraction/high-resolution gas chromatography/genetic algorithms.

Solid-phase microextraction (SPME), capillary column gas chromatography, and pattern recognition methods were used to develop a potential method for typing jet fuels so a spill sample in the environment can be traced to its source. The test data consisted of gas chromatograms from 180 neat jet fuel samples representing common aviation turbine fuels found in the United States (JP-4, Jet-A, JP-7, JPTS, JP-5, JP-8). SPME sampling of the fuel's headspace afforded well-resolved reproducible profiles, which were standardized using special peak-matching software. The peak-matching procedure yielded 84 standardized retention time windows, though not all peaks were present in all gas chromatograms. A genetic algorithm (GA) was employed to identify features (in the standardized chromatograms of the neat jet fuels) suitable for pattern recognition analysis. The GA selected peaks, whose two largest principal components showed clustering of the chromatograms on the basis of fuel type. The principal component analysis routine in the fitness function of the GA acted as an information filter, significantly reducing the size of the search space, since it restricted the search to feature subsets whose variance is primarily about differences between the various fuel types in the training set. In addition, the GA focused on those classes and/or samples that were difficult to classify as it trained using a form of boosting. Samples that consistently classify correctly were not as heavily weighted as samples that were difficult to classify. Over time, the GA learned its optimal parameters in a manner similar to a perceptron. The pattern recognition GA integrated aspects of strong and weak learning to yield a "smart" one-pass procedure for feature selection.

Algorithms↗
PubMed2000

The World Health Organization oral rehydration solution in US pediatric practice: a randomized trial to evaluate parent satisfaction.

BACKGROUND: The World Health Organization's effective, inexpensive oral rehydration solution (WHO-ORS) is used worldwide, but rarely by US practitioners because, in part, of concerns about parent satisfaction. OBJECTIVE: To compare caretaker satisfaction with the WHO-ORS, a packet-based solution requiring preparation, with satisfaction with a commercially prepared oral rehydration solution (C-ORS), (Pedialyte; Ross Nutritionals, Columbus, Ohio). DESIGN AND METHODS: Randomized controlled trial in an urban pediatric clinic and a suburban family medicine clinic. Children aged 3 to 47 months treated as outpatients for diarrhea were randomized to receive either WHO-ORS or C-ORS. After 48 hours of use, caretakers completed a telephone interview measuring satisfaction with aspects of the solution. RESULTS: Of 97 families enrolled, 91 (94%) were available for follow-up interviews. The WHO-ORS and C-ORS groups were comparable at baseline in all respects, except that slightly more caretakers in the latter group had used the C-ORS for the current illness before study enrollment (P= .06). Caretakers in the WHO-ORS group had higher overall satisfaction, satisfaction with cost, willingness to purchase in the future, and to recommend use (P<.001 for all). Differences remained significant after controlling for prior use of the C-ORS. There was no difference in satisfaction with ease of administration (P=.90), appearance (P=.20), and effectiveness (P=.80). No adverse effects attributable to either study solution occurred. CONCLUSIONS: Caretakers who prepared and used the WHO-ORS were more satisfied with their solution than a comparable group who administered C-ORS. Fear of parental dissatisfaction need not be a barrier to use of the WHO-ORS in the United States.

Child, Preschool↗