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Biomedical subjects

E Montoya

Publications and source records attributed to E Montoya.

At least 19 recordsLinked to original sources
PubMed1999

Expression analysis of the thyrotropin-releasing hormone receptor (TRHR) in the immune system using agonist anti-TRHR monoclonal antibodies.

Monoclonal anti-rat thyrotropin-releasing hormone (TRH) receptor (TRHR)-specific antibodies (mAb) were generated by immunization with synthetic peptides of rat TRHR partial amino acid sequences; one (TRHR01) was directed against a sequence (84-98) in the extracellular portion of the rat TRHR reported to be constant among different species, including man, and the second (TRHR02) recognizes the C-terminal region sequence 399-412. In lysates from GH4C1 cells, a clonal rat pituitary cell line, both mAb recognize the TRHR in Western blot analysis, and TRHR02 immunoprecipitates the TRHR. Incubation of GH4C1 cells with the mAb causes a fluorescence shift in fluorescence-activated cell sorting analysis. The cells were stained specifically by both mAb using immunocytochemical techniques. Furthermore, TRHR01 is agonistic in its ability to trigger Ca2+ flux, and desensitizes the TRH receptor. We tested for TRHR in several rat organs and found expression in lymphoid tissues. TRHR01 recognizes the human TRHR, and analysis of human peripheral blood lymphocyte and tonsil-derived leukocyte populations showed receptor expression in non-activated and phytohemagglutinin-activated T and B cells.

Animals↗
PubMed1996

[Acute pancreatitis and acquired immunodeficiency syndrome].

Viral acute pancreatitis in Human Immunodeficiency Virus (HIV) infected patients has been occasionally described. We studied nine patients with HIV antibodies and acute pancreatitis attributed to Cytomegalovirus and/or Cryptosporidium infection. In four patients the clinical picture was consistent with acute pancreatitis while in five clinical manifestations were unspecific, and diagnosis was based on ultrasonography and/or computed tomography findings. In the HIV infected patient pancreatic evaluation by imaging techniques may disclose acute pancreatitis even in the absence of abdominal pain.

Acquired Immunodeficiency Syndrome↗
PubMed1995

[Leptospirosis and pregnancy. Eleven cases in French Guyana].

The incidence of leptospirosis, a widespread antropozoonosis, is underestimated due to variable clinical presentations. The abortive effect of this disease, well known in animals, is only reported rarely in humans although transplacental transmission has been demonstrated. We report 11 cases of leptospirosis in pregnant women in French Guiana. The diagnosis was made on identification of the germ in maternal urine samples and/or on specific serology tests. Fetal death occurred in more than 50% of the cases due to premature abortion or in utero death. The rate of maternal-fetal transmissions is not known, but leptospirosis could be a not uncommon cause of perinatal deaths in endemic zones.

Female↗
PubMed1994

Autolytic effect of the antibiotic produced by Myxococcus coralloides D.

Myxococcus coralloides D secretes an antibiotic, named corallolysin, when grown on a rich medium. When a critical concentration is reached, this antibiotic lyses the producer bacterium either during vegetative growth or during morphogenesis. Corallolysin has not effect on resting cells nor on myxospores. The autolytic effect is caused by the early inhibition of RNA synthesis.

Anti-Bacterial Agents↗
PubMed1993

Divergence between biochemical and cytogenetic differences in three species of the Callicebus moloch group.

Specimens from three species of the Callicebus moloch group--C. moloch (N = 80), C. brunneus (N = 166), and C. cupreus (N = 23)--were studied. Twenty genetic loci were investigated through electrophoresis, genetic distances were estimated, and the results compared with the available cytogenetic data. Low values of genetic distance were encountered, contrasting with relatively large chromosome differences. We propose that recent karyotypic rearrangements, rather than other Pleistocene events, were the major evolutionary mechanisms determining speciation in these three taxa.

Animals↗
PubMed1992

Spontaneous cardiomyopathy and nephropathy in the owl monkey (Aotus sp.) in captivity.

Clinical and pathologic data were reviewed for 72 owl monkeys that died between January 1987 and May 1990 at the Center for Reproduction and Conservation of Nonhuman Primates in Iquitos, Peru. Tissue samples from 39 animals were examined. Hypertrophic cardiac disease (51% of animals examined), dilative cardiomyopathy (26%), and nephropathy (87%) were the most common diagnoses. The incidence of all three diseases appeared to increase with time in captivity. Nephropathy was less severe in colony-born animals.

Animals↗
PubMed1992

Mortality causes of the moustached tamarin (Saguinus mystax) in captivity.

From January 1987 to November 1990, 125 adult Saguinus mystax died at the CRCP. Enteritis/colitis (26%), hypoglycemia/cachexia (19%), and parasitic enteritis (13%) were the most common causes of death. Less common were purulent peritonitis (9%), lobular pneumonia (8%), and hemorrhagic gastroenterocolitis (6%). These results confirm the high frequency of gastroenteric lesions reported in Callitrichidae in captivity.

Animals↗
PubMed1992

Spontaneous seminoma in an owl monkey in captivity.

An adult male Aotus nancymae maintained for breeding purposes was submitted for surgery and the left testicle was removed. The surgically removed mass was about two to three times the size of a normal adult owl monkey testicle. Grossly, on cut surface, the mass was soft, white to pale gray, and bulged above the adjacent tissue. Microscopically, the morphology of the tumor cells was consistent with a seminoma.

Animals↗
PubMed1991

Sensitivity of thyrotropin secretion to TSH-releasing hormone in food-restricted rats.

The aim of the present study was to identify the mechanisms involved in the reduction of TSH secretion during prolonged food restriction. The basal TSH secretion rate, the TSH secreted in response to TRH, both in vivo and in vitro, and the TSH, nuclear T3, and plasma membrane TRH binding sites in the pituitary were determined in rats receiving 75% (FR75), 50% (FR50) and 25% (FR25) of the food consumed by the ad libitum fed rats (controls). The basal TSH secretion rate (microgram.h-1.(100 g)-1) in FR75, FR50 and FR25 groups were decreased by 19, 42 and 74% of control values, respectively, whereas the TSH secreted in response to TRH in vivo and in vitro was reduced by 21 and 13% in FR50, and 55 and 44% in FR25, respectively, of the corresponding control values. Food restriction increased the TRH binding sites from 229 in controls to 322, 479 and 521 (fmol/mg protein), in FR75, FR50 and FR25 groups, respectively, whereas the opposite was seen in nuclear T3(controls 862, FR75 841, FR50 342 FR25 233 fmol/mg DNA). Moreover, a decrease in the pituitary TSH concentration was observed in FR50 and FR25 rats. The data suggest that an alteration in the amount of TRH reaching the pituitary gland is probably the main responsible for the low plasma TSH values during food restriction. However, an inhibitory effect at the pituitary level cannot be ruled out.

Animals↗
PubMed1991

Mortality and body weight changes in Aotus nancymai shipped from Iquitos, Peru to Richland, Washington.

Four hundred and fifty wild-caught owl monkeys (Aotus nancymai) were shipped from Iquitos, Peru to Richland, Washington. Mortality and body weight changes from the time of shipment to 30 days after arrival were evaluated using age, sex, and transit time as comparison criteria. No association between mortality and sex, age, or transit time was observed. The mortality percentage from shipment to 30 days after arrival was 2.44%. Both age and transit time had a significant effect on weight changes, but sex did not. Shipping procedures are described.

Age Factors↗
PubMed1990

Effect of phosphate on antibiotic and extracellular protein production by Myxococcus coralloides D.

The effect of inorganic phosphate concentrations on antibiotic and extracellular protein production by Myxococcus coralloides D have been examined. Antibiotic production by growing cells of this myxobacterium was maximal at phosphate concentrations of 10-20 mM, but was inhibited by concentrations higher than 20 mM. The total extracellular protein and the extracellular protein per cell ratio were independent of phosphate levels in the culture broth.

Anti-Bacterial Agents↗
PubMed1990

Trichobezoars in two saddleback tamarins (Saguinus fuscicollis).

Two captive-born Saddleback tamarins (Saguinus fuscicollis) died unexpectedly in the primate colony at the Peruvian Primatological Project. At necropsy, a firm, mobile, oblong, obscure mass was discovered in the stomach of each. They were removed and determined to be trichobezoars.

Animals↗
PubMed1990

Mortality causes of owl monkeys (Aotus nancymae and Aotus vociferans) in captivity.

To determine the main causes of death in "owl monkeys" (Aotus nancymae and A. vociferans) in captivity, 115 necropsies were performed. According to the macroscopic findings and clinical data, results are as follow: acute lobular pneumonia (25.2%), chronic nephropathy (10.4%), acute catarrhal enteritis (8.7%), acute hemorrhagic enteritis (7%), acute toxic hepatitis (5.2%), trauma (5.2%), and others.

Acute Disease↗
PubMed1989

Production of acid and alkaline phosphatases by Myxococcus coralloides.

Acid and alkaline phosphatase of Myxococcus coralloides were examined during vegetative growth in a liquid medium. Two extracellular phosphatases and two cell-bound phosphatases, acid and alkaline in both cases, were produced. The phosphatase production was unaltered by the presence of high concentrations of inorganic phosphate. Both enzymes were produced constitutively. These two hydrolases were released into the growth medium during the exponential growth phase (approximately 10% of total activity). The production of these enzymes was modified by the presence of organic acids and metal ions in the medium.

Acid Phosphatase↗
PubMed1988

Mechanism of action of somatostatin.

The chain of events leading to the manifestation of the biological action of somatostatin are described. Internalization is mediated by cytoskeletal proteins in the presence of calmodulin. Transduction of the somatostatin message at the membrane level takes place through inhibition of cyclic AMP accumulation and blockade of cytosol calcium increases. The influence of central and peripheral factors upon these processes is discussed and the importance of the Ni/Ns components is stressed. Thus, somatostatin also suppresses phosphoinositide turnover and stimulates soluble phosphodiesterase, thus reinforcing its negative effect on cyclase generation.

Animals↗