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Biomedical subjects

G Mora

Publications and source records attributed to G Mora.

At least 55 records · Page 3Linked to original sources
PubMed1995

Deep hypothermia diminishes the ischemic induction of heat-shock protein-72 mRNA in piglet brain.

BACKGROUND AND PURPOSE: Expression of the 72-kD heat-shock protein (HSP72) has served as a useful indicator of ischemic stress after cerebral ischemia. Moderate hypothermia (30 degrees C) has been reported to block the induction of HSP72 after a brief episode of forebrain ischemia. The objective of the present study was to examine the effects of deep hypothermia (15 degrees C) on expression of HSP72 after a prolonged period of cerebral ischemia. METHODS: Piglets 19 to 23 days old, were placed on cardiopulmonary bypass, and brain temperature was lowered to 23 degrees C (n = 9) or 15 degrees C (n = 9) before circulatory arrest for 1 hour. In an additional group of animals (n = 5), the temperature was lowered to 29 degrees C before arrest for 45 minutes. All animals were reperfused at 37 degrees C for 2 hours, and the regional expression of HSP72 mRNA was assessed using in situ hybridization. RESULTS: After ischemia at 15 degrees C, expression of HSP72 mRNA was limited to a few scattered regions of cerebral cortex; the percentage of cortex exhibiting HSP72 mRNA was 23 +/- 7% (mean +/- SEM). Ischemia at 23 degrees C triggered expression of HSP72 mRNA in a significantly larger portion of the cortex (68 +/- 8%, P < .001). Ischemia at 29 degrees C failed to induce substantial expression of HSP72 mRNA in the cerebral cortex. CONCLUSIONS: These results suggest that, relative to ischemia at 23 degrees C, deep hypothermia (15 degrees C) diminishes ischemic alterations leading to induction of HSP72 mRNA. The lack of cortical expression of HSP72 mRNA following ischemia at 29 degrees C may be secondary to inadequate recovery of energy metabolism.

Animals↗
PubMed1994

An open-randomized clinical trial of selegiline in amyotrophic lateral sclerosis.

Based on the hypothesis that free radicals play a general role in the neurodegenerative process in motor neuron disease, we tested selegiline in a group of patients affected by amyotrophic lateral sclerosis (ALS) to examine whether it might modify the progression of the disease. Patients were admitted if they were 25-80 years old and had a confirmed diagnosis of ALS with symptoms lasting no longer than 24 months. Patients with familial ALS, pure progressive bulbar palsy, primary lateral sclerosis or progressive muscle atrophy were excluded; a total of 111 patients were recruited. Fifty-three patients were randomly assigned to receive the drug (selegiline 10 mg/day orally for 6 months) and the remaining 58 were considered ALS controls. Mortality was similar in the two groups (4 and 5 patients respectively), though the difference was not statistically significant. Among the survivors, mean MRC and Norris disability scores and forced vital capacity were fairly similar in the two groups at all times and no statistically significant difference between treated and untreated patients was found. The results did not change when the data were related to age, duration and characteristics of onset of the disease. The rate of progression was significantly more rapid in patients with bulbar symptoms in both groups. Our data do not show any significant effect of selegiline in modifying the progression of ALS.

Adult↗
PubMed1994

[Retroperitoneal ganglioneuroma. A case report and review of the literature].

Ganglioneuromas are typically of slow growth and benign evolution and may remain clinically silent for a considerable time if favourably situated. Many large examples are discovered incidentally on X-ray examination, routine abdominal palpation or at necropsy. Ganglioneuromas are often encountered in childhood and are found more frequently in the posterior mediastinum than in any other single situation; other sites are the lumbar and pelvic retroperitoneal tissues, the gastrointestinal tract and the mesentery. Diffuse alimentary tract ganglioneuromatosis has been described as port of the multiple endocrine neoplasia syndrome (MEN) type II-B. Sometimes ganglioneuromas are found in the von Recklinghausen Syndrome. The authors report in this paper a rare case of a retropancreatic ganglioneuromas.

Female↗
PubMed1993

[Malignant tumors or the small intestine. Review of the literature and report of a clinical case].

The authors present one case of patients with adenocarcinoma of the small bowel. Primary malignant tumors of the small intestine are uncommon neoplasms accounting for 1-2 per cent of all gastrointestinal malignancies. Patients are usually seen late in the course of their illness when curative therapy is unlikely. The rarity of these neoplasms explains in part why the early signs and symptoms frequently go unrecognized and is undoubtedly a major factor contributing to their poor prognosis. Despite a fourfold greater length and a nearly tenfold greater mucosal surface area, the incidence of adenocarcinoma of the small intestine is about a fortieth that of the colon. This relative immunity of the small bowel to the development of the malignant tumors is unexplainable. Several theories have been suggested and include the following: a) the rapid transit time of the small intestine may reduce its exposure to dietary carcinogens; b) the relative sterility of the small intestine compared with the colon may lessen the formation of carcinogenic substances by the action of bacteria on components of bile or other substances within the intestinal lumen; c) certain mucosal enzymes such as benzopyrene hydroxylase that detoxify potential carcinogens are present in higher concentrations in the small intestine than in the colon; d) immunoglobulin A which is found in high concentrations in the small bowel, may protect it against carcinogenic viruses. Interestingly, patients deficient in IgA and those receiving immunosuppressive therapy have been found to have a higher incidence of small intestinal cancer. Adenocarcinoma is the most common primary malignant small bowel neoplasm.(ABSTRACT TRUNCATED AT 250 WORDS)

Adenocarcinoma↗
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↗
PubMed1992

George Mora.

Explore the source record for details and available documents.

Historiography↗
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↗