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Biomedical subjects

M Gonzalez

Publications and source records attributed to M Gonzalez.

At least 271 records · Page 15Linked to original sources

Hemodynamic response to isometric handgrip in acute myocardial infarction.

Thirteen patients underwent right cardiac catheterization during the first 24 hours after the onset of symptoms of acute myocardial infarction. All had normal (less than 12 mm Hg) pulmonary arterial diastolic pressure or normal mean pulmonary wedge pressure (7.6 +/- 0.6 mm Hg). The patients did isometric forearm contraction to a measured level of 100 mm Hg. All patients had elevation of systemic systolic blood pressure, with a mean rise of 14.2 +/- 2.9 mm Hg; heart rate rose by 12 +/- 2 beats per minute. When compared to a control group, patients with acute myocardial infarction had a significant (P less than 0.005) elevation of 5.4 +/- 1.3 mm Hg in the pulmonary arterial diastolic or pulmonary wedge pressure. This may be a result of either increased left ventricular stiffness or decreased myocardial functional reserve. In the setting of acute myocardial infarction, patients with normal left ventricular filling pressures have abnormal ventricular performance. Isometric effort is poorly tolerated and should be avoided.

Adult↗

Sulfatide content and (Na+ + K+)-ATPase activity of skin and gill during larval development of the Chilean frog, Calyptocephalella caudiverbera.

The sulfatide content, phospholipid concentration, and (Na+ + K+)-ATPase activity from skin and gills of different stages of larval development of Calyptocephalella caudiverbera (a Chilean frog) were analyzed. Additionally, the short-circuit current in skin was studied. When skin and gills, depending on the stage of larval development, present (Na+ + K+)-ATPase activity, they have a high ratio of sulfatide to amount of membrane and the phosphatidylserine concentration remains unchanged. Sulfatide content and (Na+ + K+)-ATPase activity in skin are in direct relationship with the level of sodium flux present during development. The specific enzymatic hydrolysis of sulfatide with partially purified arylsulfatase of pig kidney inhibits 100% of the ouabain-sensitive (Na+ + K+)-ATPase. The ouabain-insensitive ATPase remains virtually unchanged with the treatment, even with a high concentration of arylsulfatase or with ouabain present in the medium. These experiments strongly suggest a role of sulfatides in the (Na+ + K+)-ATPase activity and, as a consequence, in sodium ion transport.

Animals↗

Stereochemistry of holoaspartate transaminase after modification of the active site Lys-258.

Proton incorporation at position C4 of the substrate-coenzyme Schiff base of aspartate transaminase is a stereospecific process. After carbamylation of the active site Lys-258, the stereospecificity of the reaction in 2H2O is retained. By a correlation method, it is shown that addition occurs from the si side of the complex and the pyridoxamine phosphate produced is deuterated at position pro-S of the pyridoxamine methylene group. These results constitute a demonstration for the stereochemstry of a half-transamination process of the phosphorylated coenzyme under single turnover conditions. They also illustrate that free Lys-258 is not required to maintain stereospecificity and cast doubts on the implication of this residue as a participant in C4 proton addition during catalysis by the native form of this mammalian enzyme.

Animals↗

Acute lymphatic leukemia with mediastinal involvement.

Mediastinal involvement was found in 11 (group A) of 43 patients affected with acute lymphatic leukemia when early thoracic roentgenograms of these patients were reviewed. Several clinicobiological characteristics of these patients were compared with those with a normal mediastinum as shown in their roentgenograms (group B). Statistically significant differences were observed between group A and group B not only as far as age was concerned (13 years group A, 7.4 years group B) but also in the ratio males/females (10:1 group A, 10:20 group B) and with regard to the leukocyte counts (266 x 10(9)/liter group A, 20 x 10(9)/liter group B). In addition, patients from group A showed a greater 'tumoral mass' and a more prominent extrahematological involvement (45% group A, 15% group B). In these cases 'convoluted' cells were frequently discovered and the blastic cells exhibited significantly lower scores of PAS-positivity and more marked acid phosphatase activity than those in group B. Although the rate of complete remissions (CR) obtained in both groups was similar (80% group A, 93% group B), marked differences were observed not only in the duration of CR but in the period of survival after CR as well, both factors being more prolonged in group B patients. 50% of patients with mediastinal involvement (group A) relapsed in the first 6 months of the evolution of the disease.

Adolescent↗

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Adolescent↗

Schooling, environment, and cognitive development: a cross-cultural study.

The purpose of this study was to investigate the influence of schooling and general environmental conditions on the development of memory and cognitive skills in young children. The subjects were 824 5- and 6-year-old children living in jungle villages and in slum settlements of Lima, Peru. Half of the children in both the jungle and city were Mestizo, and half were Quechua Indians. Some 6-year-olds of each cultural group and in each location attended school; others did not. Memory tasks were presented in different modes of representation, that is, verbal, pictorial, and enactive; and cognitive tasks in "concrete" and "abstract" versions. A sample of parents in each group was interviewed concerning environmental conditions. In addition, samples of upper-middle-class children in Lima and poor children in Detroit were tested to assess the generality of the findings. Attendance at school was related to improvement in performance on all tasks. Improvement was equivalent for both locations, both cultural groups, and each social class. Attendance at school also was accompanied by reduced within-group variability on some tasks and by greater differentiation of cognitive processes within children. Location and cultural group interacted differentially by task according to a complex pattern of relations. There were no indications that the organization of memory or cognitive processes differed as a function of social class, age, location, or cultural group. The results were interpreted in terms of children's opportunities to acquire specific memory and cognitive skills from schooling and from their general experience in a particular environment.

Age Factors↗

[Psychodynamics of ideological democracy].

In order to understand "ideological democracy" and its consecuences for therapy it is important to study the ideology of group members from the psychodynamic standpoint. Ideology is understood as a system of rules to interpret reality, although from a theoretical point of view, we contend reality itself is free from ideology. Ideology is thus defined as a cognitive system, stemming from emotional matrices of the psychosexual development of personality. The understanding of how the members of the Therapeutic Community attain "ideological democracy" is, to our mind, essential in order to be able to attain therapeutic goals. After a brief introduction the paper deals with ideology and its relationship with different personality structures: hysteric, phobic, psychopatic, depressive, paranoid and schizoid. Several common mechanisms for building ideology are set forth. The final conclusion is that such an analysis helps to ascertain the best strategies for community therapy.

Colombia↗

[Ultrastructural location of aspartate aminotransferase in the cerebellum of mice].

The histochemical location of aspartate aminotransferase by ultrastructural observation in the mouse cerebellum has been investigated. The enzymatic activity was observed specifically in the fibre endings of basket cells and in the probable terminations of golgi cells axons. This observation suggests the intervention of aspartate aminotransferase in the specific function of the cerebellum inhibitor axons.

Animals↗