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Biomedical subjects

C Hurtado

Publications and source records attributed to C Hurtado.

71 records · Page 4Linked to original sources
PubMed1988

Triglyceride and cholesterol content in bile, blood, and gallbladder wall.

Cholesterol gallstone disease is frequent in Chile compared with other countries, as is cholesterolosis of the gallbladder. The purpose of this study was to determine any differences in bile composition and cholesterol content in the gallbladder wall and serum of patients compared with findings in patients with gallstones and control subjects. In control subjects, cholesterol content of the gallbladder wall was determined in autopsy material. Patients with cholesterolosis had bile composition similar to that of patients with gallstones, with supersaturation of cholesterol in the bile. Also, these patients had increased levels of cholesterol in the gallbladder wall but normal serum cholesterol levels. These findings suggest that altered bile composition occurs in patients with cholesterolosis and gallstones.

Adult↗
PubMed1987

The in-vitro activity of metronidazole against Enterobacteriaceae alone and in mixed cultures with Bacteroides fragilis.

The in-vitro antimicrobial action of therapeutic concentrations of metronidazole against Bacteroides fragilis and six different strains of Enterobacteriaceae in pure and mixed cultures have been studied. Under anaerobic conditions, metronidazole suppressed the growth of pure cultures of the Enterobacteriaceae. A reduction in the viable counts from 10(9) cfu/ml, in the 24 h controls, to 10(8), 10(7) and 10(5) cfu/ml in the presence of 10, 50 and 100 mg/l of metronidazole respectively, was observed. These concentrations of drug produced a marked bactericidal effect against B. fragilis, as expected. The antimicrobial activity of metronidazole on mixed cultures of B. fragilis and each one of the Enterobacteriaceae studied was greater against both micro-organisms than the corresponding effect on their respective pure cultures, under the same experimental conditions.

Bacteroides fragilis↗
PubMed1987

Specific magnesium-dependent diadenosine 5',5'''-P1,P3-triphosphate pyrophosphohydrolase in Escherichia coli.

A specific Mg2+-dependent bis(5'-adenosyl)-triphosphatase (EC 3.6.1.29) was purified 270-fold from Escherichia coli. The enzyme had a strict requirement for Mg2+. Other divalent cations, such as Mn2+, Ca2+, or Co2+, were not effective. The products of the reaction with bis(5'-adenosyl) triphosphate (Ap3A) as the substrate were ADP and AMP in stoichiometric amounts. The Km for Ap3A was 12 +/- 5 microM. Bis(5'-adenosyl) di-, tetra-, and pentaphosphates, NAD+, ATP, ADP, AMP, glucose 6-phosphate, p-nitrophenylphosphate, bis-p-nitrophenylphospate, and deoxyribosylthymine-5'-(4-nitrophenylphosphate) were not substrates of the reaction. The enzyme had a molecular mass of 36 kilodaltons (as determined both by gel filtration and sodium dodecyl sulfate-polyacrylamide gel electrophoresis), an isoelectric point of 4.84 +/- 0.05, and a pH optimum of 8.2 to 8.5. Zn2+, a known potent inhibitor of rat liver bis(5'-adenosyl)-triphosphatase and bis(5'-guanosyl)-tetraphosphatase (EC 3.6 1.17), was without effect. The enzyme differs from the E. coli diadenosine 5',5'''-P1, P4-tetraphosphate pyrophosphohydrolase which, in the presence of Mn2+, also hydrolyzes Ap3A.

Acid Anhydride Hydrolases↗
PubMed1986

Effect of growth rate and aeration on the production of microcin by Escherichia coli growing in continuous culture.

The production of microcin 15, a low molecular weight antibiotic, resistant to proteases and antagonized by methionine, was measured in batch and continuous cultures of E. coli LP 136. The highest yield per cell was obtained in conditions (anaerobiosis, low glucose concentration, low growth rate) similar to those found in the intestinal tract. It is postulated that microcin production may be an important factor in growth competition between enterobacteria in the intestinal tract.

Aerobiosis↗
PubMed1982

[Chemical composition of human milk. Influence of the nutritional status of the nursing mother].

The chemical composition of human milk obtained from 16 underweight women and 25 controls collected at four, eight and 12 weeks of lactation, was determined in order to assess the effect of maternal nutrition upon milk quality. No meaningful differences were observed for protein, lactose, energy, calcium, iron and copper contents. The values obtained are comparable to those reported in the literature from developed countries. As to Zn content, both groups exhibited decreased values with time, with significant higher values for the controls at the 12th week of observation. Magnesium showed exactly the opposite behavior. On the basis of the present study, it is concluded that maternal nutrition does not condition important changes in the chemical composition of human milk. The authors propose the application of comparable methodologic and analytical criteria, in order to achieve a more complete understanding of the relationships between maternal nutrition and lactation.

Calcium↗
PubMedDate not supplied

ERK 1,2 and p38 pathways are involved in the proliferative stimuli mediated by urokinase in osteoblastic SaOS-2 cell line.

Bone metastases from prostate origin generate an osteoblastic reaction that is expressed in vitro by increased osteoblast proliferation. The urokinase-like plasminogen activator (u-PA) present in the media conditioned by tumoral prostatic cells acting as a ligand of the cellular membrane receptor (u-PAR), has been identified as the specific factor that modulates this proliferative reaction. The present study represents an effort to unravel the intracellular pathway by which u-PA activates osteoblastic proliferation and to evaluate the role of cellular receptor u-PAR in this proliferative phenomenon. Our results show that in vitro u-PA stimulates proliferation of SaOS-2 osteoblastic cells by activating the MAP kinase route of ERK 1 and 2 and the p38 pathway. These results are in accordance with the inhibition of intermediate activation and cell proliferation by PD 098059 and SB 203580, specific inhibitors of MEK and p38, respectively. We also show that SaOS-2 cells increase their proliferative response when cells are plated onto vitronectin, the second natural ligand of u-PAR, and that culturing SaOS-2 cells in the presence of u-PA represents a stimuli for u-PAR expression. On the basis of these results we propose that osteoblastic cells respond to the prostate-derived u-PA stimuli in a very efficient manner that includes the utilization of two different signaling routes and the stimulation of the expression of the u-PA receptor.

Cell Division↗
PubMedDate not supplied

[Chronic hepatitis C and celiac sprue: an infrequent association].

Celiac sprue (CS) has been described in association with hepatitis C virus (HCV) as another immunologic manifestation of this infectious disease. We report 2 patients, a 42-year-old woman and a 59-year-old man, with chronic HCV hepatitis. Upper digestive endoscopy and duodenal biopsy were performed to investigate diverse symptoms. The results of histological analysis and serological study were compatible with CS. The association between both diseases, including immunological aspects and the implications of anti-HCV treatment, is discussed.

Adult↗
PubMedDate not supplied

Man-biting activity of Anopheles (Nyssorhynchus) albimanus and An. (Kerteszia) neivai (Diptera: Culicidae) in the Pacific lowlands of Colombia.

The daily man-biting activity of Anopheles (Nyssorhynchus) albimanus and An. (Kerteszia) neivai was determined in four ecologically distinct settlements of the Naya River, Department of Valle, Colombia. Differences were found among the settlements with respect to the mosquito species present, intradomiciliary and extradomiciliary biting activity and population densities.

Animals↗
PubMedDate not supplied

Usefulness of ascites/serum lactic dehydrogenase activity ratio in the initial approach to ascites.

To investigate the usefulness of ascitic fluid protein and lactic dehydrogenase activity separating uncomplicated portal hypertension related ascites (PHRA) from non PHRA and complicated PHRA, 58 patients with full diagnosis of the cause of ascites were prospectively studied. Ascitic fluid protein led to misclassify 30% of non PHRA and complicated PHRA, and 13% uncomplicated PHRA. Ascites/serum protein ratio did not improve the diagnostic efficacy of ascites protein concentration alone. Lactic dehydrogenase activity classified properly all uncomplicated PHRA but only 64% of non PHRA and complicated PHRA. All PHRA without complications and 92% of non PHRA and PHRA with complications were correctly allocated by ascites/serum dehydrogenase activity ratio. This criteria had higher sensitivity and efficiency than total protein concentration (p < 0.05). Our data suggest that ascites/serum lactic dehydrogenase ratio may offer advantages over ascites total protein concentration discriminating uncomplicated PHRA from non PHRA and PHRA with complications in the initial approach to a peritoneal effusion.

Ascites↗