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Biomedical subjects

C Leone

Publications and source records attributed to C Leone.

53 records · Page 3Linked to original sources
PubMed1989

[Duration of breast feeding in an urban area of São Paulo, Brazil].

Duration of breast-feeding was studied by the authors among a representative sample of families with children under one year of age that resided in the area of coverage of the Health Center-School Samuel B. Pessoa in the borough of Butantã, São Paulo. The data was obtained by means of home interviews in which respondents were questioned about what type of food the child was eating that day, so that they did not have to depend on memory. The median duration of breast-feeding was found to be 2.8 months (84 days), thus showing that in the area under study early weaning is still practiced. Nevertheless, the study confirms the trend observed in the city of São Paulo in the last few years of a return to breast-feeding. This conclusion is supported by the fact that, contrary to the pattern in the previous decade, longer duration of breast-feeding is associated with higher academic levels of the parents (both), i.e., the practice is on the increase among the higher social and economic segments of the population. The study shows that the father can play a significant role in breast-feeding patterns. No correlation was found between breast-feeding duration and number of siblings, per capita monthly income, academic level of the mother, or the regularity of health check-ups.

Age Factors↗
PubMed1989

Is L-glutamate a neurotransmitter of baroreceptor information in the nucleus of the tractus solitarius?

The nucleus of the tractus solitarius (NTS) is the central termination site of peripheral baroreceptor afferents. It has been suggested that the excitatory amino acid (EAA) L-glutamate may be a neurotransmitter which mediates transmission of baroreceptor information in the rat NTS. The present studies examined this hypothesis by pharmacological blockade of EAA receptors in the NTS. Bilateral microinjections into the NTS of the EAA receptor antagonist kynurenic acid (KYN) virtually abolished baroreflexes elicited by electrical stimulation of the aortic nerve. In addition, hypotension and bradycardia evoked by injections into the NTS of the selective EAA receptor agonists N-methyl-D-aspartate, kainate and the quisqualate-selective agonist, alpha-amino-3-hydroxy-5-methylisoxazole-4-proprionic acid were reduced by 75% or more after KYN. Paradoxically, KYN did not reduce cardiovascular responses produced by injections into the NTS of L-glutamate. These results demonstrate that 1) blockade of EAA receptors in the NTS is sufficient to abolish synaptically mediated aortic baroreflexes; 2) cardiovascular responses evoked by L-glutamate are not reduced after documented blockade of N-methyl-D-aspartate, kainate and quisqualate receptors in the NTS by KYN; and 3) under the conditions of these experiments, the pharmacological actions of exogenously administered L-glutamate are not identical to those of the neurotransmitter which is released at NTS synapses by aortic nerve stimulation. These observations suggest that an EAA or EAA analog other than L-glutamate may be the neurotransmitter of baroreceptor information in the NTS.

Animals↗
PubMed1984

Thought-induced change in phobic beliefs: sometimes it helps, sometimes it hurts.

Derived two predictions from Tesser's (1978) work on thought-induced polarization. First, the longer individuals thought in a constrained manner about a phobic object, the more strongly they would believe that they were able to cope with the object. Second, the longer individuals thought in an unconstrained manner about a phobic object, the more strongly they would believe that they were unable to cope with the object. It was also predicted that, in both cases, the relationship between thought and belief change would be monotonic. These hypotheses were tested by randomly assigning phobic individuals (N = 20) to one of two treatment conditions: Constrained thought or unconstrained thought. Beliefs about extra-laboratory behavior were used to assess the effects of treatment, and results supported all predictions.

Adaptation, Psychological↗
PubMed1984

A comparison of in-vivo and imaginal participant modeling.

Recent research indicates that effective treatments of phobic reactions are often performance-based and involve exposure to the phobic object. The present study was designed to determine whether both of these components were necessary for the effectiveness of participant modeling procedures (N = 26). Phobic individuals were assigned randomly to one of two forms of participant modeling: In-vivo vs. imaginal. Both treatment analogues were identical except that the in-vivo version involved actual exposure to a phobic object, while the imaginal version simply required individuals to imagine that the phobic object was physically present. Results on behavioral and self-report measures indicated that both in-vivo and imaginal participant modeling were effective in generating increased approach behavior, but neither produced generalization beyond the laboratory setting. Explanations were discussed.

Adolescent↗
PubMed1978

[Plasma renin activity in hypertensive patients under basal conditions and in various postures: preliminary data].

We have studied PRA levels in 10 healthy subjects compared with 10 patients affected with essential hypertension (with low PRA) on venous blood samples collected after 8 hours of rest and after 15-20 minutes of slow plain walk. Contemporarely we have taken up arterious pression levels in each class of subjects of these studies. No significant differences of PRA are demonstrable in healthy subjects and in patients affected with essential hypertension. Postural changes in hypertension produces significant rise of PRA, not related to arterial pressure.

Adolescent↗
PubMed1978

[Oxoprenolol and plasmatic renin activity in essential hypertension: preliminary data].

We have studied PRA levels in 10 healthy subjects compared with 10 patients affected with essential hypertension (with low PRA) on venous blood samples collected after 8 hours of rest and after 15-20 minutes of slow plain walk and 15 minutes after intravenous administration of oxoprenolol (mg 2). Contemporarely we have taken up arterious pression levels in each class of subjects of these studies. Postural changes produces significant rise of PRA in subjects affected with essential hypertension, that is significantly inhibited by pharmacologic interference produced by beta-blocking agents. This occurrence is independent of arterial pressure changes.

Adult↗
PubMedDate not supplied

[Nutritional status of young children: a comparison among three anthropometric classifications].

OBJECTIVE: to compare the usefulness of the methods proposed by Gomez, Waterlow and W.H.O., to classify the nutritional status of children under 2 years of age. METHOD: the nutritional diagnosis of 436 infants was defined at 6, 12, 18 and 24 months of age, using the three proposed methods. Predictive values, positive (PV+) and negative (PV-), and agreement coefficient (K) were calculated, comparing the nutritional classification of the children on each method with a gold standard of nutritional diagnosis, based on individual growth performance since their birth. RESULTS: the three methods showed a good PV-, nearby 0.9, at all tested ages whereas the PV+ and K exhibited lower values. Among the three methods of classification of nutritional status, the method proposed by Gomez achieved the best levels of PV+, PV- and K, at all considered ages, mainly at 18 and 24 months of age. CONCLUSIONS: the Gomez' method, as an unique criterion, is better than the others, because it has a lower risk of misdiagnosing a case of malnutrition. Nevertheless, this risk is big enough to not recommend its isolated use, mainly during the first year of life,when the risk of a false positive diagnosis of malnutrition is still higher.

English Abstract↗