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Biomedical subjects

G R Williams

Publications and source records attributed to G R Williams.

At least 127 records · Page 7Linked to original sources
PubMed1988

Vaterian cancer in siblings.

The simultaneous occurrence of Vaterian carcinoma in two siblings suggests a genetic influence in their pathogenesis. Their classic clinical presentation of obstructive jaundice and weight loss required pancreaticoduodenectomy for this neoplasm. Pedigree analysis revealed a third sibling who died from an unresectable periampullary malignancy. Neither of the probands exhibited, as late as the seventh decade, evidence compatible with a diagnosis of familial polyposis coli or Gardner's syndrome. Flow cytometry studies revealed an aneuploid distribution in one tumor and tetraploid in the other. The rarity of this neoplasm, in the absence of contributing epidemiologic factors, suggests that this is a pleotrophic manifestation of a cancer-prone genotype.

Adenocarcinoma↗
PubMed1986

Quantitative glomerular morphology of the normal and diabetic baboon kidney.

This is a study of quantitative glomerular morphology in 14 normal and 6 long-term diabetic female baboons between 3 and 25 years of age. In the normal female baboon, peripheral glomerular capillary basement membrane thickness increased until around 10 years of age, reached a plateau between 10 and 20 years of age, and possibly decreased at 25 years of age. Mean value for young (3 to 7 years of age) and older (10 to 25 years of age) controls were 266 nm and 329 nm respectively. Fractional volumes of mesangial matrix (8.9%) and mesangial cells (6.8%) were not affected by age. Glomerular basement membrane thickness and the volume of mesangial matrix increased progressively in female baboons with poorly controlled pancreatectomy-induced diabetes, while the volume of mesangial cells remained unchanged. After 106 to 145 months of diabetes, glomerular basement membrane thickness and the volume of mesangial matrix were 558 nm and 18.7% respectively. These values were significantly greater than those of the age-matched controlled (p = less than 0.05). By light and electron microscopy, the normal baboon glomerular morphology, morphometric measurements and changes with age were similar to those in man. The renal changes in diabetic baboons were also similar in morphology and rate of development to those of mild to moderate diffuse diabetic glomerulosclerosis in humans, indicating that the baboon is an ideal model for the long-term study of diabetic glomerulosclerosis. The presence of considerable interanimal variability in the degree of glomerulosclerosis attained after prolonged diabetes suggested that glomerulosclerosis progressed at different rates in these models. The reason for this was not apparent.

Aging↗
PubMed1986

Is the treatment for thyroglossal duct cysts too extensive?

From 1970 to 1985, 64 patients underwent surgical management for thyroglossal duct cysts at the University of Oklahoma Health Sciences Center. Their ages ranged from 1 to 63 years with a mean of 12.4 years. Ninety-one percent of the patients were available for follow-up. All patients underwent one of three forms of treatment: the classic Sistrunk operation, a modified Sistrunk operation, or excision of the cyst only. Eleven percent had undergone a previous procedure. The majority of patients were found to have a cyst in the midline at the level of the hyoid bone. Eighty-eight percent of the patients underwent excision of the midportion of the hyoid bone. There were no postoperative deaths and the perioperative complication rate was 20 percent, the majority being wound-related. All recurrences took place within 4 months of operation. Factors that appeared to be associated with an increased risk of complications and recurrence included young patient age (less than 10 years), rupture of the cyst at the time of operation, infection, and failure to excise the midportion of the hyoid bone and the suprahyoid tract. One patient was found to have a mixed papillary and follicular carcinoma in the thyroglossal duct. We support the original premise of Sistrunk that "the cure of thyroglossal cyst are unsuccessful unless the epithelium-lined tract, running from the cyst to the foramen cecum is completely removed," including the hyoid bone.

Adolescent↗
PubMed1986

Chemosensory properties of sour tastants.

In Experiment 1, a taste quality fractionation procedure was used to establish the degree to which sour and non-sour taste sensations are elicited by six concentrations of each of seven acids: citric, hydrochloric, sulfuric, lactic, malic, phosphoric and tartaric. In general, the acids differed significantly in their ability to elicit sour, salty and bitter sensations, with sulfuric and hydrochloric acids producing the smallest proportions of perceived sourness. Bitterness was found to be the largest non-sour sensation produced, followed by saltiness. The perceived taste qualities of the acids were stable across a wide range of concentrations. In Experiment 2 the extent to which the vapors of these test acids produce detectable intranasal non-gustatory sensations at concentration levels used in many human taste experiments was examined. All acids induced clear intranasal sensations at concentration levels used in some suprathreshold taste paradigms. The results suggest that a number of measures of sour taste sensation may be confounded by non-sour chemosensory factors, including intranasal stimulation.

Acids↗
PubMed1985

Reoperation in congenital aortic stenosis.

Over a 22-year period, 81 patients underwent initial operations for critical aortic stenosis at our institution. Their ages ranged from 3 days to 20 years (mean, 7.3 +/- 5.9 years). Fourteen (17%) were infants less than 1 year old. Three children died perioperatively (3.7%). We have followed the survivors and 3 children who underwent initial operations elsewhere for a mean of 9.0 +/- 6.8 years (range, 2 to 23 years). To the present, 27 patients have undergone one reoperation (24 of our initial survivors) at a mean interval of 7.3 years, with 2 perioperative deaths. Ten of these patients have required a second reoperation at a mean interval of 3.7 years, with 2 deaths perioperatively. There were 3 late cardiac deaths after the initial procedure and 1 after a third operation. Actuarial reoperation-free survival is 56.7% at 10 years. While overall survival is 88.6% at 10 years, we find a significantly poorer survival among those patients with valvular stenosis compared with those with subvalvular lesions (p = 0.03). We believe that for children with all levels of aortic stenosis, good functional results and survival can best be obtained by follow-up, recatheterization, and reoperation.

Actuarial Analysis↗
PubMed1984

Interruption of the aortic arch: experience in 17 infants.

Between April, 1965, and August, 1982, 17 children ranging in age from 2 days to 4 years were identified as having interruption of the aortic arch and operated on at our institution. There were eight type A interruptions, eight type B interruptions, and one type C interruption. Associated intracardiac anomalies were present in all but 3 patients. These 3 children, who all had type A interruption, underwent repair by mobilization of the aorta and end-to-end reconstruction. The other 14 children had initial palliative operations. The 2 patients in Group 1 had type A interruption with associated ventricular septal defect (VSD), and underwent subclavian artery-aorta anastomosis. In Group 2, the palliative procedure consisted of placement of a Dacron tube graft in 1 patient with type A interruption and associated VSD, and placement of a polytetrafluoroethylene (PTFE) graft, division of the patent ductus arteriosus, and banding of the pulmonary arteries in 11 patients--2 with type A, 8 with type B, and 1 with type C interruption. Ten children (71%) survived initial palliation, 1 of the 2 in Group 1 and 9 of the 12 in Group 2. In Group 2, 5 children had interruption of the aortic arch (4, type B; 1, type C) with associated VSD; among the 4 who survived palliation, 3 subsequently have had successful closure of the VSD and 1 is awaiting closure. Among the patients who had palliative procedures, there are 6 long-term survivors (43%). In the total series, there are 9 long-term survivors (53%).(ABSTRACT TRUNCATED AT 250 WORDS)

Aorta, Thoracic↗
PubMed1983

Presidential Address: a history of appendicitis. With anecdotes illustrating its importance.

Two hundred years after its anatomical description, the appendix was observed to be the site of inflammatory disease. This was not widely accepted until the publication by Fitz 120 years later. American surgeons led in demonstrating that early appendectomy was safe and life saving. Perforation of the appendix with peritonitis continues to be a significant problem, but the mortality rate has dramatically declined. Appendiceal disease has clearly affected the course of history.

Appendectomy↗
PubMed1983

Jefferson fractures in children. Case report.

Jefferson fractures in children are exceedingly rare. A case in a 2-year-old is reported, and the other only case in the literature is reprinted. The mechanism of fracture is probably separation of the lateral masses by a force transmitted from the vertex. Because these fractures are not usually associated with neurological deficits, and because of the poor detail obtained with conventional radiography in a child, these fractures may be overlooked. Computerized tomography provides superb definition of this lesion. The preferred mode of treatment is immobilization.

Cervical Atlas↗
PubMed1983

The histology and fine structure of the ureter of the European starling (Sturnus vulgaris).

Light and electron microscopic techniques were employed to study the structure of the ureter of the starling (Sturnus vulgaris). Particular attention was paid to the characterisation of the epithelial cell types. Differences were found in the chemical composition of the mucins found in the ureteric epithelial cells and the medullary collecting ducts, which suggested that they might perform different functions. The epithelial cells were of two main types. The basally situated cells were electron-lucent, apparently relatively undifferentiated, and contained little rough endoplasmic reticulum or mucigen. The cells which were directly adjacent to the lumen were highly specialised for mucus secretion and contained extensive rough endoplasmic reticulum and large numbers of mucigen-containing vacuoles. Cells of intermediate character were also observed and the relationships between the epithelial cell types were discussed. The possibility of a holocrine mode of mucus secretion in the avian ureteric epithelium was discussed.

Animals↗
PubMed1982

A computer-based test item-bank for cognitive assessment of medical students during a clinical medicine clerkship.

The development and utilization of multiple-choice test items and the utilization of computer technology have significantly altered evaluation practices in medical schools. This paper describes the development and implementation of a computer-based multiple-choice test item-bank for use in a junior medicine clerkship. The computer program, ITEM-BANK, is an interactive system that stores and edits test items and constructs and prints an original copy of each test. Tests can be produced almost immediately by the clerical staff and the total developmental costs have been minimal. The program has reduced the amount of teaching time required to develop tests, and has enhanced the learning of essential information by medical students and residents. Teaching staff and student response has been enthusiastic and positive. Statistically significant Pearson correlation coefficients have been obtained between student performance on these tests and clinical evaluation and NBME Part II scores. The program has made a valuable contribution to the improvement of evaluation procedures in the Internal Medicine clerkship.

Alabama↗