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Biomedical subjects

S C Wilson

Publications and source records attributed to S C Wilson.

At least 37 records · Page 2Linked to original sources

Pathologic fracture.

Explore the source record for details and available documents.

Fractures, Spontaneous↗

Carotid body paraganglioma metastatic to bone: report of two cases.

Two patients with carotid body paraganglioma developed bone metastases 3 and 6 years respectively after surgical excision of the primary tumors. Plain radiographs showed ill-defined metastatic lesions. Scintigram using radiolabeled metaiodobenzylguanidine, an analogue of noradrenaline that is taken up by neurosecretary granules, showed an abnormal accumulation in the corresponding metastatic lesion. Histologically, nests of epithelioid cells with clear cytoplasm and pyknotic nuclei and abundant collagen fibers were observed within destroyed trabeculae. Treatment including external radiation and surgery provided pain relief and early local disease control.

Adult↗

Comparison of fixation methods for preventing pelvic ring expansion.

Several methods of external and internal fixation are used in urgent situations to lessen intrapelvic bleeding associated with unstable pelvic fractures. Pelvic stabilization limits pelvic expansion and thereby restricts the space for potential blood loss. This study compared several fixation methods using cadaveric pelves to determine which method best prevents pelvic expansion. Three methods of internal fixation and three methods of external fixation were compared. Anteroposterior fixation provided the greatest control against pelvic expansion; however, it is clinically impractical for emergency use. Therefore, external fixation provided the most reliable control of pelvic expansion in the emergency setting.

Cadaver↗

A simple method to measure compartment pressures using an intravenous catheter.

A simple method was investigated to measure compartment pressures using 16-ga intravenous catheters with or without side ports attached by arterial line tubing to a pressure transducer. Pressure measurements from the experimental catheters were within 4 mm Hg of the slit catheter for 99% of all readings, and pressure measurements from the Stryker device were within 5 mm Hg of the slit catheter for 95% of all readings. The addition of one or two side ports to the experimental catheters did not alter the pressure readings. This method is comparable in accuracy to the slit catheter and in simplicity to the Stryker device.

Catheterization↗

Screening the environmental fate of organic contaminants in sewage sludges applied to agricultural soils: 1. The potential for downward movement to groundwaters.

The potential for organic contaminants present in sewage sludge to leach and cause groundwater contamination following sludge application to agricultural land has been assessed. Models used to predict compound mobility in soil on the basis of physico-chemical parameters were applied to a range of contaminants prioritised and/or detected in sludge and a provisional list of potential "leachers' compiled. In addition, theoretical soil water concentrations following sludge application were calculated using mean reported sludge contaminant concentrations and soil/water partition coefficients. These estimated aqueous phase concentrations were compared with Dutch groundwater quality standards in the absence of appropriate UK standards to identify those compounds which could be present in groundwater at levels of concern. The two prioritised lists were used to identify compounds in sludge which could pose a possible threat to groundwater. Appropriate experimental data were not available to qualify model results. However, the screening exercise indicated that under routine operation practice with typical sludge application rates, and the usual range of compound concentrations detected in sludge, groundwater quality standards were unlikely to be exceeded. However, data variability, reliability and scarcity limited the usefulness of this screening approach.

Agriculture↗

Surgical management of soft tissue lesions associated with pelvic ring injury.

Mortality rates associated with pelvic ring injury combined with open wounds have decreased considerably during the past 2 decades. Consequently, increased survivability has heightened the demand for definitive stabilization techniques to address pelvic ring instability. Control of hemorrhage and avoidance of sepsis remain paramount concerns in the initial and later stages of management, respectively. Exclusion of occult and readily apparent perforations of the genital urinary and gastrointestinal tracts is essential when using a multidisciplinary approach. Recognition of open and closed degloving injury patterns and appropriate adherence to treatment guidelines will optimize outcome and avoid catastrophic complication.

Fractures, Closed↗

Improved outcomes for very low birth weight infants associated with the use of combined maternal corticosteroids and tocolytics.

OBJECTIVE: To determine the effects of maternal antenatal treatment with tocolytics, corticosteroids and the use of combined tocolytics and corticosteroids on the morbidity and mortality of very low birth weight infants. STUDY DESIGN: This retrospective study was conducted on all infants born in Tennessee in 1989 and 1990 who weighed < 1,500 g at birth and had no serious malformations. Registered nurses traveled to the delivery hospitals of all study subjects and abstracted information using a structured data collection form. Mortality was ascertained through the computerized linkage of birth and death certificates. Multiple logistic regression analysis was used to control for covariates. RESULTS: As compared to infants whose mothers received no treatment, infants whose mothers received both corticosteroids and tocolysis had a reduced risk of infant (odds ratio 0.38, 95% confidence interval 0.25-0.58) and neonatal mortality (OR 0.32, CI 0.19-0.51) as well as a reduced risk of seizures (OR 0.46, CI 0.23-0.93). Restricting the analysis of infants at 24-28 weeks' gestation and < 1,000 g at birth revealed similar findings regarding mortality. CONCLUSION: The use of combined corticosteroids with tocolytics was associated with better neonatal outcomes than the use of corticosteroids alone, tocolytics alone or no treatment.

Adrenal Cortex Hormones↗

Comparison of primate and canine models for bone ingrowth experimentation, with reference to the effect of ovarian function on bone ingrowth potential.

Bone growth into porous composite (mesh-bead) titanium plugs was compared in elderly (postmenopausal) female monkeys and female dogs as a means of validating the cross-species interpretations so often made between data from research on dogs and human applications. The effect of oophorectomy on bone ingrowth in the canine model was defined by the comparison of data on fractional ingrowth in animals that had had oophorectomy and in control animals that had had a sham operation. No significant difference in bone growth into the experimental plugs was identified between the two animal models, which lends credence to cross-species interpretation of existing data from dogs. The presence or absence of active ovaries did not affect the ingrowth fraction in the canine model; this suggests that existing data are not confounded by the lack of control of ovarian function. Estrogen depletion does not appear to influence bone ingrowth adversely.

Animals↗

PCBs and other organochlorines in human tissue samples from the Welsh population: I--Adipose.

The general exposure of humans to polychlorinated biphenyls (PCBs) and SigmaDDT (i.e., p,p'-DDT + p,p'DDE = p,p'-DDD) in Wales (UK) was determined through the analysis of adipose tissue samples collected from 75 individuals during post-mortem examinations in 1990-1991. Fifty PCB congeners were screened, of which 29 were identified in most of the samples. Congener IUPAC numbers 138, 153 and 180 were the most abundant compounds, accounting for an average of 55% of the SigmaPCB congeners analysed. SigmaPCB concentrations varied between 0.2 and 1.8 microg g(-1) of adipose tissue and were positively correlated with the donors age and negatively associated with the percentage of lipid in the adipose tissue. A progressive change in the congener pattern was noted with increasing subject age. Tissue from older individuals generally contained a relatively high proportion of the more persistent and higher chlorinated congeners. SigmaDDT concentrations ranged from 0.11 to 5.6 microg g(-1) adipose tissue, with p,p'-DDE contributing 96% towards the SigmaDDT concentration. SigmaDDT levels were also positively correlated with age. No significant differences in the SigmaPCB and SigmaDDT concentrations were noted between males and females, between people living in rural and urban locations or with the subjects' body weight at the time of their death.

Journal Article↗

PCBs and other organochlorines in human tissue samples from the Welsh population: II--Milk.

Polychlorinated biphenyl (PCB) and SigmaDDT (i.e. p,p'-DDT + p,p'-DDE = p,p'-DDD) concentrations were determined from the analysis of 115 Welsh breast milk samples collected in 1990 and 1991. Fifty PCB congeners were screened, of which 24 were identified in most samples. The PCB congener pattern was consistent between individual milk samples, with IUPAC congeners 28, 138, 153 and 180 being the most abundant and accounting for an average of 50% of the SigmaPCB concentrations determined. PCB concentrations varied between 2 and 70 ng g(-1) whole milk, were positively correlated with age, and negatively correlated with the total lactation period and with the percent lipid content of the milk. PCB pattern distributions differed between milk and adipose tissue samples. Human milk had a higher proportion of tri- (18 and 28), tetra- (44, 52 and 66) and pentachlorinated biphenyls (101) compared to human adipose tissue. SigmaDDT concentrations ranged from 0.3 to 71 ng g(-1) of whole milk, with p,p'-DDE contributing towards an average of 92% of the SigmaDDT concentrations. SigmaDDT levels were also positively correlated with age and negatively associated with the lactation period, though these correlations were rather weak. No significant differences in the SigmaPCB and SigmaDDT concentrations were noted between milk samples from donors living in rural and urban locations, or between the subjects' body weight, smoking habits or diet.

Journal Article↗

Development of an experimental model of hypothyroidism in cockatiels (Nymphicus hollandicus).

Hypothyroidism is a possible predisposing factor in a number of disorders of companion psittacine birds. We developed and validated a thyroid-stimulating hormone (TSH) response testing protocol for cockatiels (Nymphicus hollandicus), using 0.1 IU of TSH/bird given IM, with blood sample collection at 0 and 6 hours after TSH, and a commercial radioimmunoassay for thyroxine (T4). This protocol was used to document a seasonal sex difference in stimulated T4 values--females responded with higher T4 values than those in males in summer--and a stress-induced depression of baseline T4 values was detected in a group of cockatiels with normal TSH response. An experimental model for mature-onset hypothyroidism in cockatiels was created by radiothyroidectomizing cockatiels with 3.7 MBq (100 microCi) of 131I/bird given IV. Induction of the hypothyroid state was confirmed by baseline T4 concentration, TSH response test results, thyroid pertechnetate scintigraphy, and gross and microscopic examinations. Classical signs of hypothyroidism (eg, hypercholesterolemia, obesity, poor feathering) were lacking or mild at 48 days after thyroid ablation.

Animals↗

Bioremediation of soil contaminated with polynuclear aromatic hydrocarbons (PAHs): a review.

Polynuclear aromatic hydrocarbons (PAHs) constitute a group of priority pollutants which are present at high concentrations in the soils of many industrially contaminated sites. Criteria established for the removal or treatment or both of soils contaminated with PAHs vary widely within and between nations. The bioremediation of contaminated soils with in-situ, on-site, and bioreactor techniques is reviewed, together with the factors affecting PAH degradation. Current in-situ remediation techniques are considered ineffective for the removal of most PAHs from contaminated soil. On-site 'landforming' methods have been used successfully (and within a reasonable period of time) to degrade only those PAHs with three or fewer aromatic rings. Bioreactors have proved most effective for soil remediation, since conditions for enhanced degradation can be achieved most readily. However, bioreactors are still at the development stage, and further research is required to optimise their efficiency and economy for routine use. Degradation of the more recalcitrant high-molecular-weight PAHs is contaminated soil has not been particularly successful to date. Further research needs are identified to help develop bioremediation into a most cost-effective technology. The importance of full site assessments and treatability studies for successful application in the field is emphasised.

Journal Article↗