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Biomedical subjects

E Romero

Publications and source records attributed to E Romero.

At least 109 records · Page 6Linked to original sources
PubMed1984

An in vivo cholinergic influence on the retention of [3H]noradrenaline in regional brain synaptosomes.

Rats were intraventricularly (icv) injected with [3H]noradrenaline and the retention of the amine was determined in synaptosomes obtained from cerebral cortex, hypothalamus and brain stem. Previous icv administration of hemicholinium-3, effective enough to markedly decrease brain acetylcholine levels, increased the retention of synaptosomal [3H]noradrenaline in hypothalamus and cerebral cortex; this increased retention did not occur in the brain stem. The increased retention of [3H]noradrenaline, produced by hemicholinium-3, was reversed by a concomitant icv dose of choline, which in turn reversed the decrease of acetylcholine caused by hemicholinium-3. These results are interpreted as brain cholinergic activity having an influence on the turnover of noradrenaline in some brain regions.

Acetylcholine↗
PubMed1984

Bovine leukemia virus inhibiting activity in fetal calf serum.

We have obtained a new cell line persistently infected with bovine leukemia virus (BLV). BLV-infected cells can be easily detected by indirect immunofluorescence or immunoperoxidase staining technique. The morphology and number of infected cells seem to be related to serum concentration in culture medium: fetal calf serum (FCS) showed a marked effect on virus growth and virus distribution in cell cultures. All of the commercial lots of FCS tested showed BLV inhibiting activity very similar to that previously described for other viruses.

Animals↗
PubMed1984

Antibody to bovine leukemia virus in sera from leukemic patients.

A new cell line, persistently infected with Bovine Leukemia Virus (BLV), was obtained by co-cultivation of lymphocytes from adult leukemic bovine with normal calf kidney cells. The presence of BLV was demonstrated directly in the lymphocytes and in the new cell line by electron microscopy, and by ELISA of cell extracts. An immunoperoxidase staining technique was used for detection of BLV-infected cells at each new passage of the line, in order to confirm the persistence of viral infection. Fixed preparations of infected cells were used to study human sera for the presence of specific antibody to BLV. Human sera were collected from different groups of patients, and a specific antibody response to BLV was detected in only 3 out of 33 sera from leukemic patients. No positivity was detected in control sera.

Animals↗
PubMed1984

Relationship between beta-lactamases production and resistance to beta-lactam antibiotics in clinical isolates of Enterobacteriaceae.

288 clinical isolates of Enterobacteriaceae were assayed for beta-lactamase production in order to assess the role played by beta-lactamases in resistance to beta-lactam antibiotics. The data obtained showed that beta-lactamase production is undoubtedly a fundamental determinant for resistance. In fact, there was a significant correlation between the specific activity of the enzyme and the MIC of the strains considered. However, the role played by permeability barriers and/or other factors should be stressed, especially in determining resistance to cephalosporins. The validity of the nitrocefin test for detection of beta-lactamase production in Enterobacteriaeae from clinical isolates was also investigated.

Anti-Bacterial Agents↗
PubMed1983

A plasmid-linked caseinolytic activity in Enterobacteriaceae.

We have tested for production of caseinolytic activity the strain of E. coli K12 J62 carrying different R factors from various Enterobacteriaceae of clinical isolates. The results obtained showed the presence of a caseinolytic activity in 7 out of 139 R factors tested. All of these positive (cas+) R factors derived from strains of Klebsiella pneumoniae and all were able to transfer a strong lac+ phenotype as well as multiple antibiotic resistances (R-lac factors). Another strain of E. coli K12, J53, which is plasmid-free, produced levels of caseinolytic activity comparable to those of the Klebsiella R factors; J62, on the contrary, appeared to possess an inhibitor specific for the caseinolytic activities of J53 and of the R factors but not of other cas+ Gram+ and Gram- organisms. The hypothesis that the expression of the cas+ phenotype in E. coli K12 may be due to the presence of plasmid-linked regulatory genes is discussed.

Caseins↗
PubMed1978

R factors from Enterobacter group.

Twenty-six R factors transmissible to E. coli K12 were derived from 79 strains of Enterobacter species isolated in various clinical specimens (urine, sputum, blood, pus); 71 of 79 strains were Enterobacter cloacae. Fifteen R factors were fi+: 14 belonged to group FII, 1 to group FI. Eleven R factors were fi-: 5 belonged to group M, of the others 6 (all controlling the cloramphenicol-resistance) 1 was recognized of group K, 1 was incompatible with standard plasmids of both groups S and W, and 4 belonged to group S.

Anti-Bacterial Agents↗
PubMed1978

Effect of propranolol on sympathetic nervous activity in hydrallazine-treated hypertensive patients.

1 The effect of propranolol was examined on a) blood pressure and heart rate responses due to i.v. hydrallazine b) modification of these cardiovascular parameters during cold pressor test c) urinary catecholamine excretion rate. 2 Intravenous hydrallazine reduced significantly mean blood pressure by 15.2 mm Hg and increased heart rate by 24.9 beats/min. Propranolol reduced significantly mean blood pressure by 19.0 mm Hg and heart rate by 14.1 beats/min. Hydrallazine plus propranolol caused a significant reduction of mean blood pressure (by 37.7 mm Hg) but this was not accompanied by a significant fall in heart rate (by 3.3 beats/min). 3 During the control period, cold pressor test increased mean blood pressure by 16.0 mm Hg. Heart rate was increased by 12.5 beats/min in four patients. However, there was a reduction in heart rate (5.5 beats/min) in two other patients. During the propranolol period, cold pressor test-induced increase of mean blood pressure was not reduced but propranolol blocked the increase of heart rate. 4 Urinary catecholamine excretion rate was increased during hydrallazine administration. This excretion was not modified by propranolol.

Adult↗
PubMed1977

Effects of hemicholinium-3 or physostigmine on rat brain noradrenaline depletion induced by foot shocks.

Foot shocks applied to the rat on a grid floor caused brain noradrenaline depletion. Hemicholinium-3 injected intracerebroventricularly (i.c.v.) blocked the noradrenaline depletion and this blockade was reversed by choline (i.c.v.). Physostigmine (i.c.v.) had different effects according to the age of the rats: "young" and "intermediate" groups were depleted but not "adult" groups. Physostigmine plus shocks caused depletion only in "young" groups; the depletion not shown in "intermediat" groups, reappeared after pretreatment with alpha-methyl-p-tyrosine. It is concluded that there probably is a relationship between cholinergic and adrenergic neural systems when brain noradrenaline id depleted by shocks.

Age Factors↗
PubMed1977

Effect of some R factors on the sensitivity of rough Enterobacteriaceae to human serum.

Eight plasmids out of 26 tested confer partial serum resistance to Escherichia coli K-12 strains (Bhs character). Four Bhs+ plasmids were tested in a rough Salmonella typhimurium host, and three conferred partial serum resistance to this host as well. Plasmids representative of 19 different incompatibility groups were examined; the Bhs+ property was found in some (but not all) representatives of groups N, O, S, T, W, and F'lac (FI), and there was no apparent association between other plasmid markers and Bhs. It is likely that more than one mechanism can promote the Bhs+ phenotype and that Bhs genes are responsible for modifications of the surface structures involved in serum sensitivity.

Blood Bactericidal Activity↗