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Biomedical subjects

S L Williams

Publications and source records attributed to S L Williams.

At least 55 records · Page 3Linked to original sources

Long-term renal function in kidney donors: a comparison of donors and their siblings.

To assess the effects of unilateral nephrectomy, we evaluated renal function and hypertension in kidney donors who had had nephrectomies 10 years ago or more and siblings who had not had nephrectomies. No statistically significant difference was found between the prevalence of hypertension in donors and siblings. Serum creatinine concentrations were 20% higher in donors and creatinine clearances, 20% lower than corresponding values in siblings. Twenty-four-hour urinary protein excretion increased in all donors after nephrectomy and was more marked in men than women. Of the 38 donors, 12 excreted more than 150 mg/24 h of urinary protein, but only 2 excreted more than 300 mg/24 h. The presence of proteinuria did not correlate with the presence of hypertension, level of renal function, or time since nephrectomy. We conclude that, with the exception of mild proteinuria of unknown clinical significance, unilateral nephrectomy is not associated with adverse effects on kidney function.

Adult↗

Internal oblique muscle pedicle flap for coverage of a major soft tissue defect of the groin.

We describe a new muscle flap, using the internal oblique muscle as a transposition flap based on the ascending branch of the deep circumflex iliac artery, for coverage of a groin defect with exposed femoral vessels. This muscle also has potential usefulness as a pedicle flap for coverage of the anterior perineum and midline lower abdominal defects. It is a thin, flat muscle with excellent vascularity and is safe and reliable to use. The donor site scar is well concealed. The disadvantages are a possibly bloody and tedious dissection, and the long-term potential for abdominal wall weakness or herniation. In the case reported, no abdominal wall laxity or herniation were noted at eight and one-half months. We believe that the internal oblique muscle flap is a useful technique that complements the already popular methods of reconstruction for groin defects.

Abdominal Muscles↗

Effects of sulindac and indomethacin on renal prostaglandin synthesis.

We compared the effects of sulindac and indomethacin, the effects of two nonsteroidal anti-inflammatory drugs, on renal prostaglandin synthesis and renal function. Sulindac, 200 mg twice daily, indomethacin, 25 mg four times a day, or placebo were taken by 15 normal female subjects (five in each of three treatment groups). Indomethacin decreased renal excretion of prostaglandins PGE2, PGF2 alpha, and 6-keto-PGF1 alpha, but sulindac and placebo had no effect on renal prostaglandin excretion. Concomitant with the reduction of renal prostaglandin synthesis in the indomethacin group, sodium and chloride excretion decreased; sulindac and placebo had no discernible effects on urine electrolytes. Extrarenal cyclooxygenase activity, as assessed by platelet thromboxane beta 2 release, was inhibited by both sulindac and indomethacin. Plasma renin activity and plasma aldosterone levels fell in all groups as a result of positive sodium balance, but the decrements of aldosterone were greater after indomethacin and sulindac. None of the treatments altered glomerular filtration rate or renal plasma flow in these normal women. We conclude that in normal women renal prostaglandin synthesis and prostaglandin-dependent tubular functions such as Na and Cl reabsorption are relatively unaffected by doses of sulindac (200 mg twice daily) that inhibit nonrenal cyclooxygenase. This may reflect the capacity of oxidative enzymes in the kidney to convert the active sulfide metabolite of sulindac to the inactive prodrug sulindac sulfoxide.

6-Ketoprostaglandin F1 alpha↗

Loiasis in an American naturalist.

In March 1981, a 32-year-old male naturalist involved with collecting mammals for study was found to have an unexpected eosinophilia. Serum parasitic screening done at the Centers for Disease Control showed filarial titer by indirect hemagglutination of 1:1,024 and of 1:40 by bentonite flocculation. His travel history disclosed 3 months spent in Cameroon in 1978. He also gave a history of intermittent arm swelling for at least a year. Peripheral blood, collected repeatedly at mid-day and midnight and tested for microfilariae by the Knott technique, was negative. He was begun empirically on diethylcarbamazine, and on day 11 of treatment he removed a worm, identified as a male Loa loa, from his leg. He completed treatment without difficulty and has done well.

Adult↗

Epidemiologic differences between sexual and physical child abuse.

Sexual and physical child abuse are assumed to differ; however, these differences have not been well characterized epidemiologically. Furthermore, despite assumed differences, these types of abuse are often analyzed as one entity. This can have significant effects on assessment of risk and recommendations for intervention. We compared 735 cases of sexual abuse and 3,486 cases of nonsexual physical abuse confirmed by the Georgia Department of Protective Services. Sexual and physical child abuse cases differed in age, sex, and relationship of perpetrators and victims; demographic and socioeconomic characteristics of families at risk; and morbidity and mortality caused by the event. The most important recommendation based on these findings is that epidemiologically distinct forms of child abuse must be analyzed separately before intervention measures are proposed.

Adolescent↗

Pupillary attributions of college students to happy and angry faces.

As evidence for an hypothesis that pupil size plays an important role in nonverbal communication, Hess (1975) has reported that adults draw in appropriately sized pupils on his happy and angry faces task. However, he did not report a statistical test of his data. In this study, we replicated Hess' research and found congruent with his hypothesis that college students (n = 223) draw in significantly larger pupils on the happy face.

Cues↗

Neuromuscular evaluation using rat gait analysis.

We have developed a rat gait analysis model to evaluate if ankle angle and other associated gait parameters could consistently define normal peroneal nerve and anterior tibialis muscle function. The second part of the study was designed to determine if such a model would be useful to measure recovery of function after a peroneal nerve crush injury (NCI). A clear plexiglas tunnel was designed for high-speed frame videotaping and subsequent computergraphic gait measurement and analysis. Normal gait patterns for ankle angle, back height, step and stride lengths and the stance and swing times were determined in 8 rats. Data analysis demonstrated no significant left/right differences for any of the variables (ANOVA) with the exception of step length. Subsequently, 12 rats with a peroneal NCI were evaluated. All gait parameters evaluated from the injured side were significantly different from the uninjured side after injury except stride length. Ankle angle was the most sensitive outcome variable. Weekly gait analysis provided objective measurements as the ankle angle gradually returned to normal within 3 weeks. The rat gait model is a sensitive and reproducible method for non-invasive evaluation of neuromuscular function during nerve recovery after a peroneal crush injury.

Analysis of Variance↗

Lower third molar treatment planning ability of general dental practitioners and oral maxillofacial surgeons using receiver operating characteristics methodology.

A comparison of lower third molar treatment planning ability of six oral and maxillofacial surgeons (three consultants, two senior registrars and one senior house officer) and 27 general dental practitioners was carried out using Receiver Operating Characteristics (ROC) methodology. Each clinician was presented with the same series of 50 case histories and asked to indicate, using a rating scale, how certain they were that each lower third molar required removal. These data, together with NIH gold standard treatment decisions for each third molar, were then used to construct ROC curves for each clinician and, using combined data, to produce ROC curves for the groups of hospital specialists and general dental practitioners. These curves were then compared statistically. There were significant differences between the best and worst practitioners, both in the hospital service and within general dental practice. When combined data were examined, however, there was no statistical difference in the treatment planning ability of hospital specialists and general dental practitioners. These findings indicate that lower third molar treatment planning ability is more dependent upon individual factors than specialist training. Further, the data presented here suggest that general dental practitioners are as capable of treatment planning for lower third molars as the specialists to whom they refer.

Clinical Competence↗