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Biomedical subjects

M Williamson

Publications and source records attributed to M Williamson.

At least 127 records · Page 7Linked to original sources
PubMedDate not supplied

Lingual thyroid: unusual appearance on computed tomography.

A patient with a lingual thyroid was found to have inhomogeneous contrast enhancement on CT, findings not previously reported. Operative and histologic examination revealed marked thyroiditis and goitrous changes, explaining the CT findings.

Adolescent↗
PubMedDate not supplied

Spatial differences in persistent organochlorine pollutant concentrations between the Bering and Chukchi Seas (1993).

During August-September 1993, a joint Russian-United States expedition to the Bering and Chukchi Seas took place. Surface water samples were collected from 21 sites and separated into dissolved (duplicates) and suspended solids; 19 sediment and 6 air samples were also collected. These samples were analysed for 19 organochlorine pesticides, 11 chlorobenzenes and 113 PCB congeners. The report provides data on selected compounds which occured in > or = 75% of the water samples. Highest water concentrations were observed for HCH in open waters north and south of the Bering Strait, both regions being similar (alpha-HCH; 2.2 ng/L and lindane: 0.35 ng/L). Air levels observed were also constant (alpha-HCH; 0.041 ng/m3, lindane: 0.0093 ng/m3). Suspended solids and air particulares contributed little to the concentrations in their respective media, an observation common to all analytes except for the PCBs and the DDT residues. The sum of PCB concentrations in water were higher in the Bering Sea area compared to the Chukchi Sea (1.0 vrs 0.67 ng/L) and lower for air (0.46 vrs 0.23 ng/m3). Sum of DDT in water was higher in the Bering Sea than in the Chukchi Sea (0.23 vrs 0.15 ng/L) while in sediments and air, the Bering Sea concentrations were lower (0.95 vrs 1.6 ng/g and 36 vrs 56 pg/m3, respectively). Other organochlorine compounds for which data are presented include: pp'-DDE, pp'-DDT, dieldrin, HCB, 3 chlorobenzenes and 3 PCB congeners. Fluxes of all these chemicals through the Berin Strait are estimated; they ranged from 57 t/a (alpha-HCH) through 26 t/a (for sum of PCBs) to 0.2 t/a (pp'-DDE, dieldrin and 1,2,3-trichlorobenzene). Fugacity ratios for the HCHs and PCBs indicate the alpha-HCH is degassing in both the Bering and Chukchi Seas and that the gamma-isomer is degassing in the Bering Sea and is close to equilibrium (weakly absorbing) in the Chuchi Sea; the sum of PCBs are strongly absorbing in both areas.

Air Pollutants↗
PubMedDate not supplied

New graduate RN internship program: a collaborative approach for system-wide integration.

Population growth and aging increase the demand for skilled nurses. Hospitals face the challenge of supplying experienced and qualified caregivers. The cost of training new nurses remains significant. Nursing educators are pivotal in developing the nursing workforce, especially under tightening constraints. This article examines the development of a nursing internship program aimed at attracting and retaining newly graduated nurses and its effect on retention to the institution.

Cooperative Behavior↗
PubMedDate not supplied

A system for peri-operative blood glucose control in diabetes mellitus.

A pocket computer has been programmed to control the rate of administration of insulin given to diabetic patients having open heart surgery. Twelve diabetic patients were studied. Five had coronary artery bypass grafting, and seven had heart valve surgery. During operation 122 out of 162 (75%), and post-operatively 291 out of 360 (81%) blood glucose concentrations were between 4.0 and 8.0 mmol l-1. Five hundred and fifteen values out of 552 (99%) were below 12.0 mmol l-1. There was no hypoglycaemia. The lowest measured blood glucose concentration was 3.7 mmol l-1. The computer is readily available, easy to use by inexperienced personnel, and cheap.

Adult↗
PubMedDate not supplied

In vitro fluoride dose-response study of sterilized enamel lesions.

Currently our intra-oral model uses enamel specimens that have been disinfected by soaking in buffered formalin (pH 6.8). However, because of increasing emphasis on infection control, it is important to identify a way to sterilize these specimens. The aim of this study was to determine if autoclaved, or gas sterilized, lesioned enamel responds to fluoride (F) in the same way alcohol-disinfected enamel lesions do. Seventy-two formalin-disinfected, human enamel specimens (3 mm) were lesioned in demineralizing solution for 96 h and were then divided into three groups. One group was autoclaved; one group was gas sterilized (ethylene oxide), and the remaining 24 specimens were further disinfected in 70% ethanol for 10 min. Specimens in each group were then treated 4 times/day for 4 weeks with 0, 250 or 1,100 ppm F dentifrice slurries in an in vitro cycling, remin/demin model. Following treatment, fluoride uptake was analyzed by microdrill biopsy, and lesion depth and mineral content changes (DeltaM) were determined by transverse microradiography. Data were analyzed by one-way ANOVA analysis. In all three groups of specimens there were significant (p<0.05) differences in fluoride uptake in response to different fluoride treatments. Autoclaved lesions failed to provide dose- response data with regard to changes in lesion mineral content. Because formalin and 70% alcohol are only disinfectants, and autoclaving altered the responsiveness of enamel lesions, results from this study suggest that, of the methods tested, gas sterilization is the preferred method for sterilizing enamel specimens that will be used in intra-oral studies.

Analysis of Variance↗