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Biomedical subjects

G Mora

Publications and source records attributed to G Mora.

At least 19 recordsLinked to original sources
PubMed1992

Cardiorespiratory parameters in draught horses before and after short term draught work pulling loads.

In order to establish the relationship between draught force and cardiorespiratory responses to exercise heart rate (HR), respiratory rate (RR), arterial and venous blood gases, pH, hemoglobin concentration and temperature were measured in five draught horses during rest, immediately after exercise and 30 min post-exercise under field conditions. A wagon equipped with an odometer and a hydraulic dynamometer was used for measuring distance and draught force. The wagon was loaded with 946 kg for the low load, 1,979 kg for the medium load and 2,994 kg for the high load, and drawn for a distance of 1,500 m. Draught force and load weight were linearly related. The response of the draught horse to low and medium load exercise was characterized by a moderate increase in HR, RR and temperature with no significant changes in arterial blood gases and pH. An increase in HR, RR and temperature was observed, whereas no changes in arterial PO2 and increases in venous PO2 were noticed after high load exercise. Slight increase in venous lactic acid concentration as a result of high load exercise was observed, suggesting that some anaerobic work was performed. However this was insufficient to produce changes in blood pH. The increase in metabolic requirements during the three levels of draught exercise was associated with increases in arterial hemoglobin concentration and oxygen content of blood.

Acid-Base Equilibrium↗
PubMed1991

Effects of steroidal and non-steroidal antiandrogens on the androgen binding properties of the rat ventral prostate androgen receptor.

Steroidal (cyproterone acetate) and non-steroidal (RU23908 and hydroxyflutamide) antiandrogens are able to block testosterone-induced increases in nuclear androgen receptor (AR) in the prostate of 1-day orchidectomized rats, but when given alone, RU23908 and hydroxyflutamide increase nuclear AR (RU23908 greater than hydroxyflutamide) in the same animal model. The increases in nuclear AR induced by antiandrogen alone or with testosterone alone are blocked by cycloheximide 1 h after administration, suggesting that androgen or antiandrogens induce de novo AR synthesis. Concomitant to nuclear AR accumulation, testosterone is able to induce depletion of cytosol and microsomal AR. Blockade of testosterone-induced depletion of microsomal AR, but not of cytosol AR, occurs in the presence of antiandrogens. Cyproterone acetate has a higher relative binding affinity (RBA) for microsomal AR and cytosol AR than RU23908 or hydroxyflutamide. This phenomenon is in good agreement with the degree of inhibition by these compounds of the association rate of androgen for the microsomal AR. This correlation between RBA and inhibition of the initial rate of hormone binding to the receptor is not found for cytosol AR. The results show that antiandrogens are not 'pure' antagonists of androgen action and they are potent agonists in the absence of testosterone. Furthermore, testosterone alone or antiandrogens per se regulate AR levels acutely by protein-synthesis dependent mechanisms of action, in rat ventral prostate.

Androgen Antagonists↗
PubMed1989

Evaluation of Western immunoblotting technique in the serological diagnosis of human syphilitic infections.

Purified human syphilitic antibodies against both 15.5 Kd and 45 Kd treponemal antigens appear T. pallidum specific and do not cross react with antigens possessed by other treponemes (T. phagedenis, T. hyodysenteriae and a human intestinal treponeme). By using Western immunoblotting technique, 107 out of 110 syphilitic patients and 291 out of 294 subjects with serologically positive diagnostic tests for syphilis were found to have in their sera antibodies against a 15.5 Kd specific antigen of T. pallidum. These antibodies were present in 100% of the patient with secondary or early latent syphilis, both untreated and treated, in 98.24% of those with late latent treated syphilis and in 100% of patients with neurosyphilis. On the contrary, they were absent in 47 patients with false positive reactions for syphilis and in 121 healthy blood donors. For these reasons, the demonstration of these kind of antibodies in a patient's serum can be considered of high value in differentiating syphilitic patients from non infected individuals.

Antibodies, Bacterial↗
PubMed1989

Effect of naloxone and luteinizing hormone releasing hormone pulses on plasma luteinizing hormone concentration in ewe lambs.

A study was conducted to determine the effect of pulses of naloxone on plasma LH concentration in prepubertal ewes and to see if this treatment affects the pituitary response to subsequent LHRH pulses. Prepubertal ewes (n = 5) received three intracarotidal pulses of naloxone (NAL, 1 mg/kg BW) and four pulses of Luteinizing Hormone Releasing Hormone (LHRH, 1 micrograms/pulse) at hourly intervals. Control ewes (n = 5) received saline instead of NAL followed by the LHRH pulses at the same frequency. Blood samples were collected from one hour before the first pulse of saline or NAL at 15 min intervals for four hours and at 30 min intervals for another four hours. Plasma LH concentration was measured by radioimmunoassay. The first pulse of NAL increased plasma LH levels compared to the basal levels and compared to control animals (P less than 0.01). The succeeding pulses were ineffective. LHRH provoked an increase in plasma LH concentration in control as well as in treated animals but the amplitude of the net peak height increased progressively up to the third pulse in NAL treated animals, while there was no increase in pituitary responsiveness to LHRH in control prepubertal ewes. Also, the area under the LHRH response curve was greater (P less than 0.05) in animals pretreated with NAL than in lambs pretreated with saline. The results suggest that there is an inhibitory opioid tone over LH secretion in female lambs. NAL increases the responsiveness to exogenous LHRH pulses, probably as a result of endogenous LHRH release.

Animals↗
PubMed1987

Cloning, expression and characterization of the 36 KDal Salmonella typhi porin gene in Escherichia coli.

A recombinant plasmid containing the gene for the 36 KDal porin of Salmonella typhi has been identified in a cosmid library of S. typhi propagated in Escherichia coli. The recombinant clone was identified by its ability to endow E. coli with susceptibility to porin specific phages, and by the appearance in the outer membrane of E. coli containing the clone of a new protein of 36 KDal. While the porin confers upon a porinless mutant of E. coli an increased susceptibility to beta-lactam antibiotics, it does not react with serum from patients with typhoid fever in immunoblotting assays.

Bacterial Outer Membrane Proteins↗
PubMed1986

Native and chemically modified porin channels from Salmonella typhi Ty2 in planar lipid bilayers.

Native porins, from Salmonella typhi Ty2 outer membrane, and porins alkylated with pyridoxal phosphate (Plp) were studied in planar lipid bilayers. The conductance of bilayers exposed to native or chemically modified porins increases in discrete jumps. Conductance histograms for native porins displayed two major peaks at 1.7 and 6.7 nS (in 0.5 M KCl). On the other hand, Plp-treated porins exhibited a single major peak at 1 nS. The relation between bilayer conductance and native porin concentration was linear. However, this relation became logarithmic in the presence of modified porins. The results support the notion that alkaline reduction of S. typhi Ty2 porins with Plp dissociates porin channel trimers in a reversible fashion.

Alkylation↗
PubMed1986

Early decrease in total hemolytic complement activity (CH100) after fasting or intestinal bypass in the rat.

An evaluation of total hemolytic complement activity (CH100) after fasting or intestinal bypass was performed in rats. The experiment lasted 6 days. Three groups, of 5 animals each, were studied. On the 1st day, basal values of total complement (TC), albumin and body weight were determined. Group A received normal, ad libitum feeding, group B started on a 'water only' diet, group C underwent intestinal bypass. On the 4th and 6th day the parameters were assessed. TC mean values were significantly lower in groups B and C, as compared to group A, on the 4th as well as on the 6th day (p less than 0.01 by Mann-Whitney's U test). Body weight showed a similar trend. Differences in albumin were never statistically significant. Limitations of the analytical method are discussed. The data show that fasting or bypass-induced malabsorption may determine an early decrease in total hemolytic complement activity, though a development of an immune deficiency is not proved.

Animals↗
PubMed1979

1978 anniversaries.

The author recalls 1978's anniversaries of events and individuals prominent in the history of medicine, psychiatry, and psychology and examines their practical and theoretical contributions.

Europe↗
PubMed1979

The proteins of the cytoplasmic ribosomes of Euglena gracilis.

Two types of cytoplasmic ribosomes of Euglena gracilis have been found when the stability in vitro of the large subunit at 25 degrees C for 30 min has been considered. Sucrose density gradient analysis have revealed that the large subunit of ribosomes obtained from cells harvested in the stationary phase of growth was degraded when heated at 25 degrees C. The large subunit of ribosomes obtained from exponentially growing cells was stable in the same experimental conditions. Studies of the ribosomal RNAs have not explained this differential stability observed in vitro. In fact, after SDS-extraction, the largest RNA species always appears degraded in both types of ribosomes. Therefore, an explanation to this phenomenon have been searched for through the analysis of the ribosomal proteins. One and two dimensional gel electrophoresis techniques have been employed. At least one difference between the two ribosomal protein groups has been observed and this could be associated to the differential stability of the ribosomes. Approximately 72 proteins molecules have been found in Euglena's cytoplasmic ribosome. About 42 proteins belong to the large subunit and 30 to the small one.

Animals↗
PubMed1977

1977 annivesaries.

The author recalls this year's anniversaries of events and individuals prominent in the history of medicine, psychiatry, and psychology and examines their practical and theoretical contributions.

Famous Persons↗
PubMed1976

1976 Anniversaries.

The author recalls this year's anniversaires of events and individuals prominent in the history of medicine, psychiatry, and psychology and examines their practical or theoretical contributions.

England↗