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Biomedical subjects

P Samuel

Publications and source records attributed to P Samuel.

98 records · Page 6Linked to original sources

Effect of neomycin on exchangeable pools of cholesterol in the steady state.

Five patients received cholesterol-7alpha-(3)H intravenously during control periods. Specific activity of total serum cholesterol was determined serially during the 1st wk and weekly thereafter. 28-59 wk after the injection of the tracer, when no further radioactivity could be detected in serum cholesterol, 2 g of oral neomycin was given daily to four patients for the remainder of the experiment. Average total serum cholesterol concentrations were reduced by 20, 21, 26, and 29%, respectively, in these subjects. The fifth patient, given placebo, had no change in serum cholesterol. After a period of 12-26 wk of medication the intravenous injection of cholesterol-7alpha-(3)H was repeated, and while neomycin or placebo administration was continued, serum cholesterol specific activity was again determined serially during the 1st wk and weekly thereafter for 23-42 wk. The data were subjected to a two-compartment analysis. During the administration of neomycin, half-times of the cholesterol radio-activity decay curves were decreased in two patients and remained unchanged in two subjects. The size of the "intermediate" pool of cholesterol decreased in each patient during the administration of neomycin by 33, 36, 40, and 44%, respectively. The absolute decrease was much larger in each case than the concomitant reduction of serum cholesterol. There was no significant change in the data during the administration of placebo in one patient. The size of the "intermediate" pool can be calculated by compartmental analysis from the cholesterol decay curves. For the "slow" pool size and the other kinetic parameters only ranges of values can be deduced from the present experiment.

Aged↗

Absorption of bile acids from the large bowel in man.

The absorption of bile acids from the human large bowel was studied in eight patients. All patients had cholecystitis and cholelithiasis and had to undergo cholecystectomy. Cholic acid-(14)C was injected during surgery into the lumen of the cecum, hepatic flexure of the colon, or transverse colon in six patients, under the visual control of the surgeon. Common duct bile was collected by T tube daily for 5 days, and bile acids were extracted. Significant amounts of radioactivity appeared in T tube bile in each patient. T tube bile acids contained a total of 43.6-84.6% of the administered radioactivity; the average for the six patients was 58.9%. The majority of the tracer was excreted during the first 24 hr. In an additional patient cholic acid-(14)C was given in the form of an enema 5 days postoperatively. In this subject 30.8% of the retained radioactivity was excreted through the T-tube in 48 hr. The labeled cholic acid was recovered as both cholic and deoxycholic acid from T tube bile. Thin-layer chromatographic analysis of the bile acid samples indicated that the fraction of radioactivity recovered as deoxycholate increased with time during the postoperative period. Gas-liquid chromatographic analysis showed that the daily total quantity of excreted bile acids increased significantly from the 1st-5th days of the experiment. The amount of cholate excreted in T tube bile increased markedly with time, that of chenodeoxycholate increased moderately, and that of deoxycholate decreased sharply during the 5 days of the experiment. In three patients, injection of radiopaque material mixed with the tracer showed no evidence of regurgitation into the small bowel by serial X-rays. In an additional patient, tube aspirate from the terminal ileum contained no radioactivity. The results indicate that cholic acid is converted to deoxycholic acid in the human colon, and both of these bile acids are absorbed from the human large bowel in significant amounts. These data establish the previously unproved concept that significant absorption of bile acids takes place from the large bowel of man.

Adult↗

Effects of fenofibrate on plasma lipids. Double-blind, multicenter study in patients with type IIA or IIB hyperlipidemia.

Of 240 patients with Type IIa and IIb hypercholesterolemia recruited in 11 centers, 227 were randomized to double-blind treatment with either fenofibrate (100 mg three times daily) or matching placebo for 24 weeks. A group of 192 of these patients were studied for a further 24 weeks during which all received fenofibrate in open label fashion. For the 92 Type IIa patients receiving fenofibrate in the double-blind phase, there were significant reductions (p less than 0.01 compared to baseline) in total plasma cholesterol (-18%), LDL-cholesterol (-20%), VLDL-cholesterol (-38%) and total triglycerides (-38%). Mean plasma HDL-cholesterol in these patients increased by 11% (p less than 0.01). With the exception of LDL, which was not high before treatment, similar changes were seen in the 24 fenofibrate-treated Type IIb subjects. Lipid parameters of placebo-treated patients did not change significantly. This pattern of change was repeated in the open period for the 94 patients previously on placebo, while the 98 who had been on fenofibrate remained stable with small further reductions in total and LDL cholesterol (-38% and -5.5% respectively). Adverse effects were some allergic-type skin reactions early in treatment and an occasional increase in transaminases, BUN, or creatinine. The results were similar to those obtained in European open trials of fenofibrate and were better than the lipid changes seen at comparable times in the Lipid Research Clinics Coronary Primary Prevention Trial (LRC-CPPT) cholestyramine study.

Cholesterol↗

[Subtalar dislocations with medial or lateral displacement (author's transl)].

The authors have observed 20 cases of subtalar dislocation, 16 with medial displacement and 4 with lateral displacement. The treatment given and the results are described. An experimental study has also been made which confirms that in medial dislocations the talo-navicular joint dislocates first whilst in lateral dislocations the talo-navicular joint dislocates last. The severity of assoicated lesions is emphasised. It is concluded that in severe displacement with complete extrusion of the talus, tibio-calcaneal arthrodesis gave better results than excision of the talus.

Adolescent↗

Trends in leprosy over fifty years in Gudiyatham Taluk, Vellore, Tamil Nadu.

This paper presents epidemiological trends over a fifty-year period observed in a defined population served by the Schieffelin Leprosy Research and Training Centre (SLR & TC), Karigiri, Vellore District in Tamil Nadu. It covers three distinct periods, namely, the pre-MDT era with dapsone monotherapy, the MDT era under a vertical leprosy control programme and the MDT era after leprosy control services were integrated into the general health services. Prevalence rates have declined steadily from 125 per 10,000 population at the time of introduction of MDT in 1982 to 5 per 10,000 at the time of integration in 1997 to less than 1 per 10,000 in 2005. The new case-detection rate was 5.4 per 10,000 when the field programme started in 1962, and held steady at 15-20 per 10,000 between 1970 and 1980. It then showed a gradual fall from 10.8 per 10,000 in 1985 to 3.9 at the time of integration, and continued to fall in the post-integration period and was 0.8 per 10,000 in 2005. The mean age at detection showed a gradual increase from 23.4 years in the dapsone era to 31.2 years in the post-integration period. The male: female ratio showed a preponderance of males almost throughout the reference period. While polar types of leprosy (TT & LL) were common in the dapsone era, more of borderline leprosy (BT & BL) cases was seen more recently. MB rates that were high initially, declined steadily during monotherapy and stabilized between 10% and 12% during the vertical MDT programme and is showing an increase in the post-integration-period. The proportion of cases with Grade 2 disability at registration showed a gradual decline during the monotherapy period, remained relatively unchanged at 8%-10% during the the MDT period, and showed a sharp rise in the immediate post-integration period before falling. Analysis of trends of leprosy in a well-defined geographical population over a fifty-year period gives useful information on how the disease has evolved over the years. It provides opportunities to explore the reasons for the changes observed, though one has to be cautious while interpreting such data due to changes in definition, the play of operational factors, and changes in policies and strategies.

Adult↗