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Biomedical subjects

R D Williams

Publications and source records attributed to R D Williams.

At least 181 records · Page 10Linked to original sources
PubMed1980

Incidental carcinoma of the prostate: a review of the literature and critical reappraisal of classification.

The problem in treating incidental carcinoma of the prostate is that of distinguishing between tumors that will have a long, benign natural history and those that will progress rapidly. A review of the English literature concerning incidental prostatic carcinoma reveals that patients with focal low grade tumors have a good prognosis, while patients with high grade lesions often suffer rapid tumor progression. By contrast, the clinical significance of high volume, low grade tumor is unknown. A method has been developed to evaluate the distribution of prostatic cancer using 4-quadrant transurethral prostatic resection. A detailed method for staging these cancers based on a comprehensive, segmental histopathological analysis also is presented. A precise definition of the stages of prostatic cancer should eventually improve our understanding of the natural history of this disease.

Adult↗
PubMed1980

Abdominal staging of testicular tumors using ultrasonography and computed tomography.

There were 36 patients with testicular tumors who underwent abdominal staging by ultrasonography, computed tomography or both before removal and pathologic examination of the retroperitoneal lymph nodes. Results showed that ultrasonography and computed tomography are accurate in predicting retroperitoneal metastases in more than 80 per cent of the patients, although computed tomography is more accurate and specific. The 1 falsely negative result with both methods occurred in a patient with microscopic (pathologic stage IIA) retroperitoneal disease. The falsely positive results with either technique were found in patients with borderline enlargement of the nodes (1 to 1.5 cm). Either computed abdominal tomography or abdominal ultrasonography is recommended for pre-treatment staging of testicular tumors.

Abdominal Neoplasms↗
PubMed1980

Effect of penicillin and virginiamycin on drug resistance in lactose-fermenting enteric flora.

Three groups of beagle dogs were fed either a control diet, a diet containing virginiamycin (55 microgram/g of diet), or a diet containing penicillin (110 microgram/g of diet). The proportions of lactose-fermenting organisms in their feces that were resistant to ampicillin, dihydrostreptomycin, tetracycline, or chloramphenicol were measured by a comparative plate-counting procedure. Both antibiotic-supplemented diets resulted in an increase (P < 0.001) in the occurrence of ampicillin, dihydrostreptomycin, and tetracycline resistances during the time of their administration. The occurrence of these resistances was greater (P < 0.001) in the group receiving penicillin than in the group receiving virginiamycin. In addition to the above resistances, a greater (P < 0.001) occurrence of resistance to a sulfonamide (sulfamethoxypyridazine) due to treatment was found by susceptibility testing of isolates. Representative isolates were able to transfer their resistance to a strain of Escherichia coli K-12.

Ampicillin↗
PubMed1979

Carcinoembryonic antigen-like substance derived from human prostate.

Carcinoembryonic antigen-like substance, previously detected in large amounts in the medium from cultures of human prostatic epithelial cells, also is present in extracts of benign and malignant human prostate. By column chromatography, the prostate-derived carcinoembryonic antigen-like substance derived from cultured prostate is the same as that in tissue extracts and is distinctly different from colon-derived carcinoembryonic antigen. The molecular weight of prostate-derived carcinoembryonic antigen-like substance is estimated to be greater than 5 x 10(5). Prostate-derived carcinoembryonic antigen-like substance may be a prostate-specific substance.

Adenocarcinoma↗
PubMed1978

Intermittent hydroephrosis. A cause of abdominal pain.

Intermittent hydronephrosis may appear as acute abdominal pain. Between episodes of pain, the patient may be asymptomatic, and the intravenous urogram usually will be normal. The condition is diagnosed from intravenous urograms taken either during an episode of pain or after hydronephrosis has been precipitated by hydration. There are many causes of intermittent hydronephrosis; however, the closed renal pelvis and nondistensible ureteropelvic junction are important factors in nearly all cases. Pyeloplasty is the best treatment and is usually curative.

Abdomen↗
PubMed1978

In vitro cultivation of human renal cell cancer. II. Characterization of cell lines.

Two cell lines derived from primary human renal-cell cancers (RCC) have been established and characterized. Cell line 786-O has been in culture for longer than 1 year and has been subcultured more than 50 times. It has a doubling time of 45 hr and a hypertriploid karyotype and possesses a Y chromosome. Cell line 769-P also has been in culture for longer than 1 year. It has been subcultured 50 times and has a doubling time of 35 hr and a hypodiploid karyotype. Cells from both lines are epithelial, and they produce tumors in the cheek pouches of immunosuppressed hamsters. Neither cell line is contaminated with Mycoplasma. Cells of the two lines can be distinguished from HeLa cells both by their karyotypes and by the mobility patterns of their isoenzymes of glucose-6-phosphate dehydrogenase.

Adenocarcinoma↗
PubMed1978

Biochemical markers of cultured human prostatic epithelium.

Medium from primary cultures of human prostatic cells was examined for polyamines and carcinoembryonic antigen. Spermine was elevated in medium from 5 of 17 epithelial cell cultures but was not found to be a specific marker for cultured human prostatic epithelial cells. Carcinoembryonic antigen was elevated in all 27 prostate epithelial-cell culture fluids tested, 24 of which had more than 20 ng. carcinoembryonic antigen per milliliter. Medium from other cultured human cells (prostate fibroblasts, genitourinary tumor and non-tumor cells), as well as control medium, contained less than 1 ng. carcinoembryonic antigen per milliliter. Carcinoembryonic antigen, as measured in this study, is a way to demonstrate the presence of human prostatic epithelial cells in culture.

Autoanalysis↗
PubMed1978

Effect of feeding chlortetracycline on the reservoir of Salmonella typhimurium in experimentally infected swine.

Swine were fed either a diet containing 110 mg of chlortetracycline (CTC) per kg (100 g/ton) or a control diet and were inoculated orally with Salmonella typhimurium that was either susceptible or resistant to CTC. The quantity, duration, and prevalence of fecal elimination of S. typhimurium, as well as the effect of CTC on the transmission of S. typhimurium from infected to uninfected swine, were determined. When animals were infected with CTC-resistant S. typhimurium, CTC increased the quantity (P < 0.05), duration (P < 0.05), and prevalence (P < 0.01) of fecal shedding, the transmission from infected to uninfected swine, and the recovery of the infecting organism at necropsy. When animals were infected with CTC-susceptible S. typhimurium, CTC reduced the quantity (between 7 and 10 days postinfection) (P < 0.01), duration (P < 0.05), and prevalence (P < 0.05) of fecal shedding, the transmission from infected to uninfected swine, and the recovery of the infecting organism at necropsy. Resistance to tetracycline was transferred in vivo to 4 and 6% of the susceptible infecting S. typhimurium recovered from the untreated and treated groups, respectively. The increased reservoir of S. typhimurium and the transfer of resistance to susceptible S. typhimurium have implications for both animal and public health.

Animal Feed↗
PubMed1978

Demonstration of nonperfused myocardium in late hemorrhagic shock.

Studies were performed to determine whether or not regions of left ventricle become nonperfused in the normovolemic stages of hemorrhagic shock. Using the endothelial fluorescent stain thioflavin S as a tracer, nonperfused myocardium was assessed in six control dogs, eight dogs in early normovolemic shock, and 15 dogs in late normovolemic shock. Nonperfused myocardium was not demonstrable in any of the control animals and in only one of the early shock animals. However, in nine of the late shock animals, nonperfused myocardium was clearly evident, particularly in the anterior and posterior papillary muscles. The demonstration of nonperfused myocardium in late shock is compatible with the concept of a progressively developing edema with a consequent interruption of blood flow.

Animals↗
PubMed1978

Urolithiasis in patients with a jejunoileal bypass.

Five hundred and seventeen patients who had a jejunoileal bypass performed at the University of Minnesota Hospitals were studied with regard to the formation of urinary calculi postoperatively. A 9 per cent incidence of stones was found in the 365 patients for whom complete data were available. Men were affected more commonly than women. Of particular note was the correlation between long term oral supplementation of calcium postoperatively and a delay in the onset of symptomatic urolithiasis. A group of 91 recent patients who have been maintained on orally administered calcium are stone-free as long as 12 months after operation, again suggesting that supplementation of calcium may help prevent urolithiasis in patients who have had a bypass procedure.

Adult↗
PubMed1977

Aneurysm contents as a source of graft infection.

During the past 5 1/2 years, cultures were taken from 68 to 151 surgically treated aortic aneurysms. These cultures were made from nonblood fluids, laminated clot, necrotic areas of the aneurysm wall, or ulcerated atheromatous plaques. Organisms were harvested from seven of the 68 cultures, including Staphylococcus, Escherichia coli, Pseudomonas, and hemolytic Streptococcus. Prophylactic antibiotics were used in all patients; however, the organisms cultured, excepting Streptococcus, were not sensitive to the chosen antibiotics. Three of the seven patients with a positive aneurysm culture died of causes unrelated to infection. Evidence of graft infection has not developed in four surviving patients with positive cultures. Knowledge of the presence of bacteria permitted massive antibiotic therapy based on organism sensitivity.

Aged↗