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Biomedical subjects

R Castro

Publications and source records attributed to R Castro.

At least 145 records · Page 8Linked to original sources
PubMed1984

[2 cases of tularemia observed at Monte Amiata].

Two cases of tularemia caused by direct contact with an infected hare are described. Recent epidemiological discoveries about the disease are reported with reference to other known foci in Tuscany and the measures taken to control and isolate the infected areas.

Adult↗
PubMed1984

Suprazygomatic SMAS in rhytidectomy.

A personal method for the treatment of the suprazygomatic SMAS and its results are presented. By acting on the suprazygomatic fibromuscular layer in the rhytidectomy, the surgeon can avoid tension on the cutaneous layer, and possible consequences thereof, as well as diminish the probabilities of damaging the facial nerve. At the same time, desired effects as a result of pulling on "crow's feet," wrinkles, lateral eyebrows, and wrinkles on the lateral forehead are enhanced.

Face↗
PubMed1984

Different roles of catecholaminergic and serotoninergic neurons of the medial forebrain bundle on male rat sexual behavior.

The medial forebrain bundle (MFB) plays an important role in the central elaboration of male sexual behavior. However the role of its ascending monoaminergic systems is not well understood. By selective lesions of catecholaminergic and serotoninergic axons of the MFB, produced with 6-OHDA and 5-7-DHT respectively, its possible involvement in male sexual behavior was studied. The evaluation of the behavioral patterns was studied by means of a microcomputer which also permitted the quantification of sequences in the sexual behavior patterns. Lesions with 5-7 DHT increased the intromission-ejaculation sequences and the percentage of ejaculatory males, without modifying other behavioral tests. Lesions with 6-OHDA diminished the number of "active" sexual patterns and motor activity. In order to check the specificity of the chemical lesions, the in vitro uptake of labeled norepinephrine and serotonin was measured, 5-7 DHT lesioned rats show a reduction in the uptake of 5-HT-C14 in the MPOA while 6-OHDA group show a reduction of NA-H3 in the striatum.

Animals↗
PubMed1984

Effects of monoamine neurotoxins injected in different brain areas on gonadotropin and androgen secretion in the male.

In order to investigate the relative contribution of the serotoninergic and catecholaminergic innervation of different brain structures to the control of gonadotropin secretion in the male, adult rats were given bilateral injections of the selective neurotoxins, 5,7-dihydroxytryptamine and 6-hydroxydopamine, into the mediobasal hypothalamus, the medial preoptic area, the amygdala, and the medial forebrain bundle. Serum levels of luteinizing hormone (LH), follicle-stimulating hormone, testosterone, pituitary follicle-stimulating hormone, and LH content were measured 15 days later. The medial preoptic area 5,7-dihydroxytryptamine injections were followed by 2- to 3-fold increases of serum LH and testosterone levels and pituitary LH concentration. The 6-hydroxydopamine injections in the medial forebrain bundle resulted in a 60% decrease of pituitary LH content, associated with serum levels of LH and testosterone which were lowered, although not significantly. None of the treatments seemed to influence either serum or pituitary concentrations of follicle-stimulating hormone. These results suggest a hitherto undocumented major function of the serotoninergic innervation of the medial preoptic area in the control of LH secretion in the male and confirm previous reports indicating that some of the catecholaminergic fibers carried by the medial forebrain bundle can be modulatory for LH secretion.

5,6-Dihydroxytryptamine↗
PubMed1984

[Effect of pineal indoles and testosterone on sex behavior].

The possible action of melatonin and 5-methoxytryptophol, two pineal indoles, upon castrated male rat sexual behaviour with three testosterone dose levels was studied. Both indoles reduced the number of mounts and intromissions. 5-Methoxytryptophol, in addition, decreased the number of ejaculations. The sexual actions of the pineal indoles are prevented by the administration of high testosterone dose levels (500 micrograms/day).

Animals↗
PubMed1981

Effect of sodium butyrate treatment of HeLa cells on the transcriptional activity of their isolated nuclei.

Sodium n-butyrate has been used as a tool to study the presumptive effects of the in vivo hyperacetylation of histones from HeLa cells on the transcriptional activity of their isolated nuclei. No gross differences were found in either initiation or RNA synthetic capacity among the nuclei from control or butyrate treated cells. The electrophoretic pattern of the RNA synthesized in nuclear suspensions was markedly affected by prior exposure of the cells to the fatty acid.

Butyrates↗
PubMed1981

[Subcellular study of ethanol action on myocardium (author's transl)].

The effect of ethanol on calcium binding activity in plasma membrane from dog cardiac muscle is described. The binding activity to sarcolemma was measured by the centrifugation method. The ethanol effect on the activity was studied by measuring the amount of bound calcium when the preparation was incubated in an ethanol containing solution at a desired concentration. Results showed that membrane bound calcium increased with ethanol concentration of up to 180 mM. Higher concentrations only decreased the amount of bound calcium.

Animals↗
PubMed1979

Direct and indirect effects of ethanol on isometric tension in rabbit isolated strip auricle.

Besides the negative inotropic action of ethanol on cardiac muscle, this paper describes also an "indirect effect" which appears when the ethanol treated isolated strip auricle preparation is washed with low Ca Tyrode solution. This effect depends on the previous concentration of ethanol in the isolated organ bath. A kinetic analysis of the washout effect of ethanol shows that just the first tension diminution phase is altered by the action of ethanol. The results suggest that alcohol may act also on inner membranes of myofibrils.

Animals↗