Search PubMed⌕ Search

Biomedical subjects

M Ortega

Publications and source records attributed to M Ortega.

At least 91 records · Page 5Linked to original sources
PubMed1994

The Magnuson-Stack operation for recurrent anterior dislocation of the shoulder. A long-term follow up of 44 operations.

A retrospective review was carried out on 44 patients with recurrent anterior dislocation of the shoulder who were treated by the Magnuson-Stack operation. The average follow up was 12 years. There were 2 recurrences. Twenty-five patients had no symptoms, 3 had pain, 6 complained of subjective instability, and 8 had more than 10 degrees restriction of external rotation. No patients had signs of osteoarthritis in the joint. The satisfactory results and the ease of the operation are reasons for advocating this procedure.

Adolescent↗
PubMed1994

Fast purification of Phaseolus vulgaris isolectins.

Phytohemagglutinin from red kidney bean has been purified by affinity chromatography on a human alpha 1-acid glycoprotein Sepharose 4B column. Further purification of the hemagglutinin's five isolectins was achieved on a Mono S column with an 86% protein recovery. Each sequentially eluted isolectin from the ion exchange column displayed either hemagglutinating or mitogenic activity. The main activity of each fraction was the result of the combination of varying proportions of the L and E subunits.

Animals↗
PubMed1994

[Effect of somatostatin on the hemodynamic changes induced by acute experimental pancreatitis in the conscious rat].

The aim of this study was to determine the hemodynamic effect of somatostatin, either prophylactically or therapeutically, in shock caused by acute necrohemorragic pancreatitis in conscious rats. For this purpose, radioactive microspheres were used in 3 groups (control pancreatitis, therapeutic somatostatin and prophylactic somatostatin), performing a basal and final hemodynamic study. In the control group, acute necrohemorragic pancreatitis resulted in overwhelming shock with decrease of 55% in cardiac output, 58% in renal blood flow, increase in total peripheral resistances of 342%, and death after 70 min. Therapeutic somatostatin decreased cardiac output by 42%, renal blood flow by 47%, and increased total peripheral resistances by 153%. Prophylactic somatostatin decreased cardiac output by 24%, and renal blooded flow by 28%; it increased peripheral resistances by 146%, and improved survival up to 97 min. In conclusion, therapeutic somatostatin, and particularly prophylactic somatostatin, improved hemodynamic shock after acute necrohemorragic pancreatitis in conscious rats.

Acute Disease↗
PubMed1993

[Hypersplenism secondary to splenic tuberculosis].

We report a case of abdominal tuberculosis with predominant splenic involvement and hypersplenism in a patient without any risk factor for tuberculosis. We review the literature and emphasize the unusual splenic involvement, the difficulties in the specific diagnosis and the therapeutic strategy. We conclude that this disease should be included in the differential diagnosis of hypersplenism.

Aged↗
PubMed1993

Calmodulin activated adenylyl cyclase in ciliary processes: additivity of calcium and cyclic adenosine monophosphate signals on intraocular pressure response of the rabbit eye.

PURPOSE: The regulation of adenylyl cyclase by multiple signal systems was investigated by biochemical studies of the enzyme in ciliary processes and by in vivo intraocular pressure responses in the rabbit eye. METHODS: Adenylyl cyclase enzyme activity was determined by radiometric assay using alpha-32 P-ATP as substrate. Drugs were administered to the rabbit eye by intravitreal injection or topical application, and intraocular pressure was measured by pneumatonography. RESULTS: Adenylyl cyclase activity in the membrane/particulate fraction of the rabbit ciliary process was activated by calmodulin in the presence of Ca2+, Co2+, or Mn2+, and inhibited by the calmodulin antagonist calmidazolium. The activity was additive to stimulations of adenylyl cyclase by the activating G-protein (Gs) via isoproterenol or vasoactive intestinal peptide receptors, and by forskolin. The biochemical findings were supported by in vivo correlation experiments with intravitreal injection of MnCl2, and by topical treatment with the Ca(2+)-mobilizing alpha 1-adrenergic agonist phenylephrine and with agents affecting cyclic adenosine monophosphate levels (forskolin, isobutylmethylxanthine). The intraocular pressure response was augmented by combining threshold doses of phenylephrine with threshold doses of either forskolin or isobutylmethylxanthine. The maximal and most prolonged response (a decrease in intraocular pressure of 4 mm Hg for up to 8 hr) was obtained by combination treatment with all three agents at doses that produced no significant effect by themselves. CONCLUSIONS: These findings provide a biochemical mechanism for ocular hypotensive drugs having both a Ca(2+)-mobilizing activity as well as increasing cyclic adenosine monophosphate levels by receptor-coupled stimulation of adenylyl cyclase.

Adenylyl Cyclases↗
PubMed1993

[Risk of low birth weight in the Plaza de la Habana region].

The objective of this study was to confirm the risk factors (RF) for low birth-weight (LBW) and suggest new risk factors, which were analyzed separately and together, in order to define a program to be coordinated by family doctors to reduce the frequency of this problem. For this purpose, a retrospective cross-sectional survey was carried out with 57 cases (mothers who had had LBW babies) and 58 controls (mothers who had not had LBW babies). In addition, data were obtained from the prenatal records of mothers who received care at family doctors' offices and at the clinica in the Plaza de la Habana Area. Estimates were made of the relative risk and the percentage attributable risk of 107 hypothetical RF for LBW from a clinical-epidemiological and social standpoint. One-way analysis of variance, the chi-square test, multiple linear regression, and logistic regression were used to analyze the results, which suggested the following RF for LBW: family dysfunction, family crisis, lack of spousal support, extended family, failure to attend prenatal group sessions for pregnant women, and failure to receive education on how to prevent LBW. The multifactorial risk profile was the following: risk of [corrected] intrauterine growth retardation, family dysfunction, threat of preterm delivery, coffee-drinking, attendance at fewer than 11 prenatal checkups, and failure to attend prenatal group sessions for pregnant women. The variables excluded from the model were: low weight-for-height, lack of spousal support, smoking more than 10 cigarettes a day, and family history of LBW. The findings confirmed 10 of the suspected risk factors for LBW in Cuba and nine of those described in the international literature. Maternal age, spontaneous abortion, and alcohol consumption were not confirmed. Six RF for LBW preventable by the family doctor through his/her actions at the family and community level are identified, as is a multifactorial profile of six RF for LBW. On the basis of these results, proposals are made in regard to programming priorities and the implementation of strategies aimed at preventing LBW, and it is recommended that the study be continued with a larger sample.

Adolescent↗
PubMed1992

[Cystic neoplasm of the pancreas as a cause of intestinal obstruction].

Cystic neoplasms of the pancreas are unusual varieties of pancreatic tumors. We herein report a new case presenting with atypical features, such as mental and electrolytic disturbances secondary to upper intestinal obstruction. We reviewed the literature, and discuss the differential diagnosis, the histopathological characteristics of prognostic value, and the therapeutic strategy. We conclude that these tumors should be included in the differential diagnosis of the upper intestinal obstructions, and emphasize the need to remove the lesion in all cases because of the difficulties of predicting the benign or malignant behaviour of these tumors before and during the surgical procedure.

Cystadenocarcinoma↗
PubMed1991

Cloning of coliphage-T4 gene pseT and high-level synthesis of polynucleotide kinase in Escherichia coli.

The gene, pseT, of coliphage T4 which encodes polynucleotide kinase (PNK) was cloned directly into an expression plasmid using the polymerase chain reaction. When placed under the control of the trp promoter, the pse T gene can be maintained stably in Escherichia coli and yields high levels of the enzyme upon induction. The system described facilitates purification and provides very high yields of PNK.

Base Sequence↗
PubMed1991

[Endogenous digitalis].

During the past 10 years, several groups of researchers from different laboratories have carried out research on an endogenous substance or substances which had cross immunoreacted to digoxin antibodies in patients without previous cardiotonic treatment. The increase has been demonstrated in various clinical cases which involve an augmentation of plasmatic volume. A considerable amount is known about its molecular structure and anatomic origin; the competitive inhibition of the sodium pump being quite clear.

Animals↗
PubMed1991

[AM3 (a biological response modifier) in the treatment of recurrent aphthous stomatitis. Clinical evaluation and preliminary studies on NK (CD16) cells and their pathogenic role in the syndrome].

In an open-controlled trial--oral washes (20 patients) versus test (19 patients)--, we have studied the effects of AM3 (a new oral BRM) on clinical evolution of the recurrent stomatitis (RAS) syndrome. The results obtained at 6th month showed significant decreases on ulcer numbers (p less than 0.001) as well as in their mean duration time (p less than 0.001) due to the AM3 treatment. From a pathophysiologic point of view, the study of the NK peripheral blood cells (Leu 11/CD16) suggests the existence of two kinds of RAS-patients: those showing normal NK cell numbers (approximately 33%) and those ones showing a partial lack in the NK numbers (approximately 67%). These results suggest different rational new approaches to treatment, based on new pathophysiological concepts.

Adolescent↗