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Biomedical subjects

A Flores

Publications and source records attributed to A Flores.

At least 145 records · Page 8Linked to original sources
PubMed1988

Studies on the microheterogeneity of anterior pituitary follicle-stimulating hormone in the female rat. Isoelectric focusing pattern throughout the estrous cycle.

Anterior pituitary (AP) glands were removed from adult female rats at different times throughout the estrous cycle, and the isohormones of follicle-stimulating hormone (FSH) present within them were separated by isoelectric focusing in polyacrylamide gels (PAGE-IEF; pH range 3.0-8.0). Gel eluents were analyzed for FSH content by radioimmunoassay (RIA) and radioreceptor assay (RRA). All AP samples exhibited several peaks of FSH immunoactivity within a pH range of 6.2-4.0; the major peak constantly exhibited an isoelectric point (pI) of 4.9-4.5. To quantify differences in the IEF pattern of AP-FSH between the pituitaries collected during the different days of the cycle, each PAGE-IEF profile was divided into 7 regions (pI 7.0-6.3 = Area 1, 6.2-5.5 = Area 2, 5.4-5.0 = Area 3, 4.9-4.5 = Area 4, 4.4-4.0 = Area 5, 3.9-3.5 = Area 6, and less than 3.5 = Area 7), and the amount of FSH present within each was determined. In all APs collected at 0900 h of diestrus 1 (D1) and 2 (D2), proestrus (P), and estrus (E); at 1300 h of D1, D2 and E; at 2200 h of P; and at 0200 h of E, the majority of FSH immunoactivity (37-55% of total FSH on gel) focused within Area 4, whereas Areas 2 and 3 contained minor amounts of FSH activity (11-26% and 14-24%, respectively).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1988

The lipids of chalazia.

The tissue contents of chalazia taken from five individuals were extracted for lipids and analyzed by TLC and GLC. Lipids found were sterol esters 9%, wax esters 0%, triacyl glycerols 4%, free cholesterol 11%, free fatty acids 2%, unidentified nonpolar material 3%, ceramides 7%, cerebrosides 3%, phosphatidyl ethanolamine 12%, phosphatidyl choline 20%, sphingomyelin 4%, lysolecithin 4%, unidentified polar material 18.0%. GLC of the sterol esters gave peaks corresponding to the C14, C16, C18 and C20 normal fatty acid esters of cholesterol. The free fatty acids were also of the normal kind. Thus, the lipids of chalazia contents show little similarity to the lipids of the meibomian gland. The latter has a large component of sterol esters and wax esters. Also the fatty acids of all the meibomian gland ester lipids have significant amounts of iso- and anteisobranching in contrast to the chalazia lipids. Chalazia lipids more closely resemble the lipids of membranes of phagocytic cells with a large cholesterol content.

Adolescent↗
PubMed1985

Postmortem bacteriology of cadaver tissue donors: an evaluation of blood cultures as an index of tissue sterility.

Microbiological cultures were performed on the blood and bone marrow of 239 cadaver bone donors and 58 "beating heart cadaver" organ donors who had been asymptomatic of sepsis. The incidence of positive blood cultures was significantly lower among the "beating heart cadaver" donors (8.6%) as compared to other donors from whom tissues were excised up to 30 hr postmortem (38%). Microorganisms were isolated from the bones of 82 of 148 (55.4%) bone donors as well as from 36 of 53 (67.9%) "beating heart cadaver" donors who had negative blood cultures. The majority of microbial species recovered from the blood and bone marrow belonged to species normal to the skin microflora (coagulase-negative staphylococci, Bacillus and Propionibacterium species). Species of Clostridium were the second most common organisms isolated from the blood. Blood cultures alone were not useful as indicators of sepsis in cadaver tissue donors or as an index of the sterility of the tissues excised for transplantation.

Bacteriological Techniques↗
PubMed1984

Subcellular fractionation of actively growing protoplasts of Saccharomyces cerevisiae.

Cell homogenates obtained from partially regenerated Saccharomyces cerevisiae protoplasts were fractionated by a procedure using a combination of continuous and discontinuous sucrose gradients, under experimental conditions that minimize possible artifacts due to centrifugation and resuspension. At least five different membranous organelle fractions (plasma membrane, mitochondria, rough endoplasmic reticulum, smooth endoplasmic reticulum-like structures and small-sized particulated structures) were isolated. Subcellular fractions were characterized by assaying established marker enzymes. Radioactive labelled [(U-3H]uracil) ribosomes were also used as a further characterization criterion of the rough endoplasmic reticulum. Comparative SDS-polyacrylamide gel electrophoresis of the protein constituents of the isolated membrane-bound organelles suggest that the polypeptide pattern could also be used as an additional marker for some of these structures. Finally, subcellular distribution of chitin synthase was determined using this fractionation procedure, and two partially zymogenic enzyme pools (one inside the cell associated to particles which sediments at high speed, and the second one associated to the plasma membrane) were found.

Acetates↗
PubMed1983

Simultaneous isolation of the yeast cytosol and well-preserved mitochondria with negligible contamination by vacuolar proteinases.

Disruption of yeast spheroplasts by DEAE-dextran in isoosmotic conditions allows isolation of relatively undamaged subcellular fractions from yeast. The preservation of mitochondria and vacuoles permits the simultaneous isolation of the cytosol with negligible contamination by vacuolar proteinases and therefore, virtually eliminates proteolytic artefacts.

Cell Fractionation↗
PubMed1983

Chronic diarrhea associated with Clostridium difficile in children.

Clostridium difficile toxin was associated with chronic diarrhea without classic symptoms of colitis in seven children (age range, 7 weeks to 7 years). All patients had received antibiotics. Six of the seven were treated with vancomycin hydrochloride and demonstrated improvement. After treatment, four patients suffered relapses, and three required further therapy. One patient had four relapses. During all clinical relapses, toxin reappeared in the stool; recovery was always associated with its disappearance. Fifty-six percent of family contacts examined had positive cultures. These findings document C difficile as a probable cause of chronic diarrhea in childhood and emphasize its infectious potential.

Bacterial Toxins↗
PubMed1980

Steroid structure and function VII. remarkable estrogenicity of 3-hydroxy-9 beta-estra-1,3,5(10)-triene-11,17-dione.

Remarkably high estrogenic activity was observed for 3-hydroxy-9 beta-estra-1,3,5(10)-triene-11,17-dione despite its unusual bent conformation. The 9 alpha epimer of this compound has markedly less activity despite the fact that its overall shape is nearly identical to that of estrone. The potency of these compounds in enhancing uterine weight in Fischer rats and reducing ovarian weight in parabiosed rats was compared with that of estrone, and the structures were unambiguously identified by X-ray crystallographic study. The results underscore the importance of the phenolic ring A to estrogenic activity, and suggest a tolerance of the putative estrogenic receptor to flexibility in overall molecular shape.

Animals↗
PubMed1979

Neurologic disturbances in Paget disease of bone: response to calcitonin.

The neurologic manifestations of Paget disease and the therapeutic effect of calcitonin were studied in 49 patients. Twenty-four patients (49%) had neurologic disorders involving cranial nerves other than the auditory system, brainstem, spinal cord, or spinal roots and nerves. Eighteen of the 24 patients (75%) showed significant subjective or objective improvement after calcitonin treatment. The effect of calcitonin treatment on spinal cord compression was dramatic in three of six patients. The observations made of these patients support previous data suggesting that the neurologic signs and symptoms of Paget disease have their pathogenesis in both mechanical impingement and vascular distortion. The importance of early detection of neurologic signs and symptoms is emphasized, since prompt treatment with calcitonin may prevent severe complications.

Aged↗
PubMed1978

Cancer of the tonsil--a retrospective study.

Treatment of cancer of the tonsil continues to be a controversial matter. A review of the otolaryngological literature and a study of 155 patients treated at the University of British Columbia reveals that the cure rate remains unsatisfactory, particularly in patients with large tumors. We have concluded that early carcinoma of the tonsil should be treated with a full course of radiotherapy reserving surgical treatment for residual or recurrent disease. Advanced carcinoma of the tonsil requires planned combined therapy. Early results indicate that the addition of chemotherapy may significantly improve results over the usual combination of radiotherapy and surgery.

Adolescent↗