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Biomedical subjects

S Sayed

Publications and source records attributed to S Sayed.

34 records · Page 2Linked to original sources
PubMed1983

Tolerance of diets deficient or excessive in selenium by Syrian hamsters.

Syrian hamsters were fed torula yeast (TY) diets with 8 selenium (Se) supplement levels (0.0-10.0 ppm Se as sodium selenite) or casein (C) diets with 5 supplement levels (0.0-5.0 ppm Se as sodium selenite) for 25 weeks. Whole blood Se, plasma glutathione peroxidase (GSH-Px) activity and erythrocyte GSH-Px activity were measured after 5, 10, 15 and 25 weeks. At 25 weeks hematology was examined and tissue samples analyzed for Se and evaluated for histopathological lesions. While survival was not influenced by dietary Se, food consumption and body weight gain were altered in animals given TY, as those fed 0.0, 0.05 or 10.0 ppm Se consumed less diet. Weight gains at 25 weeks were highest in animals at the 0.1 ppm Se level and reduced in those given unsupplemented TY or 10.0 ppm Se supplements. Hemoglobin, hematocrit and red blood cell counts were reduced in females fed the lowest and highest Se supplements with TY diets. With both C and TY, whole blood Se rose with increasing dietary Se and in the case of TY, Se was elevated with each feeding increment, except between the 0.05 and 0.1 ppm or the 0.25 and 0.5 ppm levels. Plasma GSH-Px increased with rising Se up to 10 ppm, and erythrocyte GSH-Px activity increased up to 5 ppm Se. Erythrocyte GSH-Px values were higher in animals fed C diets. Histopathological observations were normal at all Se levels. Syrian hamsters tolerated dietary Se from 0.05 to 5.0 ppm Se for 25 weeks of observation without detrimental effects.

Animal Feed↗
PubMed1982

Hyperplastic, preneoplastic and neoplastic lesions found in 83 human pancreases.

A thorough histologic examination of the pancreas was performed on autopsy material from 83 military veterans aged 35-88 years. Hyperplastic, preneoplastic and neoplastic alterations were recorded by severity, multiplicity, location and age. From this material, two patients had clinically known primary, and three had secondary (metastatic), pancreatic cancer. The following occult malignant lesions were found: two early cancers (one adenocarcinoma and one adenosquamous cell carcinoma), one ductal carcinoma in situ and seven ductular carcinomas in situ. Among patients with ductular carcinoma in situ, three had pancreatic caner and the remaining four had cancers of other sites (ethmoid, ear, colon, prostate). One patient who was clinically diagnosed as having lung cancer with selective metastases to the pancreas was found to have pancreatic adenosquamous cell carcinoma with lung metastases. Hence, the incidence of neoplastic exocrine lesions was around 10%. In addition, hyperplasia of the ductal and ductular epithelium (in 57% and 39% of the patients, respectively), squamous cell metaplasia of the ductules (in 48% of the cases), as well as endocrine tumors (islet cell adenoma, 10%; mixed ductular-insular adenoma, 3%) were found. Most lesions occurred in the pancreatic head, a few in the tail. These data and other reports led to the conclusion that, first, the overall incidence of pancreatic cancer appears to be higher than previously reported. Malignant lesions seem to remain clinically occult, either because patients die of other diseases or because of the significantly long latency between premalignant lesions and clinically recognizable invasive cancer. Second, the ductular cells appear to be the progenitor cells of a variety of tumor types, including squamous cell cancer and islet cell tumors, as in the authors' experimental model.

Adult↗
PubMed1982

[The hydatid cyst of kidney in children. Report of 12 cases (author's transl)].

The authors report 12 cases of hydatid cyst of the kidney in children. Age distribution is between 3 and 13 years: 7 girls and 5 boys. The diagnosis is easier when there is an evident hydatid context with other visceral localizations. The complications are rare. Surgical treatment will be conservative on utmost and consists very often in partial pericystectomy with upphostering of the residual cavity. Partial nephrectomy and total pericystectomy are useless and dangerous.

Adolescent↗
PubMed1981

Sex differences in the effects of retinoids on carcinogenesis by N-nitrosobis(2-oxopropyl)amine in Syrian hamsters.

Syrian hamsters were given in a single dose of N-nitrosobis(2-oxopropyl)-amine (BOP) (40 mg/kg, s.c.) and 1 week later were fed 1 of 4 retinoid types (13-cis-retinoic acid (13-cis-RA), N-ethylretinamide (ERA), 2-hydroxyethylretinamide (OH-ERA), or 4-hydroxyphenylretinamide (PRA)) each at 3 levels (0.05, 0.1, 0.2 mM/kg diet). The pancreatic carcinoma incidence was not influenced significantly by feeding retinoids. The pancreatic adenoma incidence, however, was reduced by feeding each of the retinoids to female hamsters, with the reduction varying with the retinoid fed (13-cis-RA greater than ERA and OH-ERA greater than PRA). In male hamsters increased numbers of pancreatic adenomas were observed after feeding OH-ERA and PRA. Tumors induced in other tissues were reduced by retinoids in females, but not in males. Females fed 13-cis-RA and ERA had a lower incidence of gall bladder polyps, and feeding OH-ERA reduced the liver tumor incidence. Food consumption and serum alkaline phosphatase ans aspartate amino transferase activities were not influenced by BOP or retinoid type or level. Body and pancreas weight were influenced by retinoid level, but the effects were not consistently dose-related.

Animals↗