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Biomedical subjects

P Ruiz

Publications and source records attributed to P Ruiz.

338 records · Page 19Linked to original sources
PubMedDate not supplied

Preliminary study of the in vitro activity of irloxacin against mycobacteria.

Today Mycobacterium avium and Mycobacterium tuberculosis multidrug resistance are responsible for frequent and severe infections in humans and especially in AIDS patients. Irloxacin is a new quinolone derivative, and shows greater activity with an acid pH. It has a good in vitro antimicrobial spectrum against both gram-positive and gram-negative bacteria. We have compared the in vitro activity of irloxacin against mycobacteria (20 M. tuberculosis, 17 M. avium, 5 Mycobacterium bovis, 5 Mycobacterium chelonae, 5 Mycobacterium fortuitum and 1 Mycobacterium gadium) using the Bactec at pH 6.8 and 5.0, with other quinolones (ofloxacin, ciprofloxacin, pefloxacin and 27753 RP). All quinolones tested showed good activity against mycobacteria at pH 6.8 and 5.0. Irloxacin at pH 5.0 had a greater activity against M. avium.

Anti-Infective Agents↗
PubMedDate not supplied

Renin-like activity in the rat brain during the development of DOC-salt hypertension.

Levels and distribution of an angiotensin-forming enzyme, active at the physiological pH (isorenin), were determined in the central nervous system of 24 rats treated with 25 mg/kg of deoxycorticosterone (DOC) subcutaneously, twice a week, plus saline to drink during 30 days and in 14 control animals. Different areas of the brain were excised and homogenized. Renin activity and concentration were determined by incubation of the supernatant of each homogenate at pH 7.2 alone and in the presence of an excess of renin substrate. The angiotensin generated was measured by radioimmunoassay. Concentration of the renin-like enzyme was significantly higher in the posterior hypophysis and in the brain stem of the experimental group; isorenin activity was higher in the hypothalamus, cerebral cortex, cerebellum, and brain stem of the DOC-salt-treated rats than in the control rats. Changes in the angiotensin-forming enzyme in the central nervous system of experimental animals, active at physiological pH, suggest that this isorenin system may play a role in the physiological response to DOC-salt in the rat. The significance of the brain isorenin system in the regulation of blood pressure requires further analysis.

Animals↗
PubMedDate not supplied

Vascular structural changes in DOC-salt hypertensive rats.

Vascular alterations in DOC-salt hypertensive rats 10 and 30 days after the onset of the treatment were studied and compared with those from rats receiving only DOC, rats drinking salt, and control rats. Wet weight and absolute amounts of deoxyribonucleic acid (DNA) and ribonucleic acid (RnA) of the artery wall were significantly increased in DOC-salt rats 10 and 30 days after the onset of the treatment. RNA/DNA and protein/DNA ratios were similar in all the experimental groups. The arteries of DOC-salt animals incorporated tritiated thymidine at a higher rate 10 days after beginning the treatment, while the uptake was similar in all the animals at the end of the experimental period. These results would indicate that, in this type of hypertension, the increase in artery mass is mainly the result of cellular hyperplasia, which is active during the early phase of the process; afterward the vascular wall reaches a new steady state characterized by a greater number of cells and no further cell proliferation.

Animals↗
PubMedDate not supplied

Angiotensinogen concentration in the cerebrospinal fluid in different experimental conditions in the rat.

Angiotensinogen is the most important component of the renin-angiotensin system present in the cerebrospinal fluid (CSF) of the rat. Its physiological significance as well as its origin have not been clearly elucidated. In this experiment we have examined plasma renin activity (PRA) and plasma and CSF angiotensinogen concentration under the following experimental conditions in male rats of the Wistar strain: 1) adrenalectomy (Adx) 4 days prior to sample collection; controls were sham Adx animals; 2) nephrectomy (Nx) 48 hours before blood and CSF collection; controls were sham Nx rats; 3) DOC-salt treatment (Cortexon depot, 50 mg/kg.s.c. twice a week) plus saline to drink was given during 4 weeks; controls were intact rats; 4) DOC-salt plus captopril: captopril (100 mg/kg/day) in the drinking fluid was added to the treatment of experimental and control animals of Group 3; 5) two-kidney, two clip hypertension: silver clips placed in both renal arteries 8 weeks before samples collection; control: sham-operated rats; 6) water deprivation: rats deprived of water for 5 days; controls: intact rats; 7) peripheral sympathectomy: 6-hydroxydopamine (6-HODA) injected s.c. from birth until 16 weeks of age, adrenodemedullectomy and adrenal denervation performed at 8 weeks; controls were vehicle-injected animals. Determination of angiotensinogen concentration in plasma and CSF was accomplished by incubation of the samples with excess hog renin. The angiotensin I released as well as PRA were evaluated using an specific radioimmunoassay technique. PRA was significantly increased by Adx, captopril treatment, and water deprivation, and was almost suppressed by Nx, DOC-salt, and DOC-salt plus captopril treatment.(ABSTRACT TRUNCATED AT 250 WORDS)

Adrenalectomy↗
PubMedDate not supplied

Pulmonary embolism with bone fragments following vertebral body marrow infusion for tolerance induction.

Protocols of donor bone marrow infusion for tolerance induction are receiving increasing attention in clinical trials of organ allotransplantation. We report pulmonary embolism with bone fragments following vertebral body marrow infusion in a recipient of a liver and intestinal transplant. Even though pulmonary embolism with bony microfragments has been widely described following bone marrow transplantation, the use of single, high-dose donor bone marrow infusion and/or multiple infusions currently under clinical investigation for induction of donor specific unresponsiveness, may warrant the implementation of additional steps in the vertebral body marrow processing technique to decrease or eliminate the component of bony microfragments in the final preparation.

Bezoars↗