Increased or decreased locomotor response in rats following repeated administration of apomorphine depends on dosage interval

Administration of drugs that reduce the influence of dopamine at its receptor site can lead to postsynaptic supersensitivity, whereas treatment with dopamine (DA) agonists can cause postsynaptic subsensitivity. Both unaltered and enhanced postsynaptic responses to DA have been shown after pretreatment with DA agonists. In the present manuscript pretreatment with apomorphine, a dopaminergic agonist, is shown to induce either increased or reduced locomotor activity. When a drug-free period between successive injections was allowed, apomorphine induced an enhanced locomotor response, whereas a reduced response occurred when each dose was injected before the previous apomorphine dose had been completely metabolized. Pretreatment with both high (1 and 3 mg/kg) and low (0.05 mg/kg) apomorphine doses enhanced the response. Apomorphine treatment that caused enhanced locomotor responses did not modify the stereotypy response to the drug. Similar enhanced or reduced response were found in rats with partial lesions of the nigrostriatal system. These altered responses to DA agonists may have important clinical consequences. The present data also suggest the existence of a different DA systems for locomotor and stereotypy actions of dopaminergic agonists.

[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.

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.

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.

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.

[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).

[Duodenal varices. Review of the literature apropos of a case]

The authors report a case of digestive hemorrhage secondary to isolated duodenal varicosities, in a patient with ethylic cirrhosis. The diagnosis done through optical fibroscope was confirmed by arteriography. The evolution was unfavorable. Lesions were corroborated by autopsy. A review of the literature is done, about the 22 cases already published. With the help of these cases to authors stress the points that can lead to the good diagnosis and what therapeutical management should be done.

[Colorectal anastomotic stricture : transanal resection using the E.E.A. autostapler (author's transl)]

Anastomotic stricture is an unusual complication of the colo-rectal surgery ; this can be very difficult to manage, particularly in low anastomosis. About one case successfully treated, the authors suggest an original non operative treatment : a resection with simultaneous anastomosis only performed through a transanal approach, with upper coloscopic control.

[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.

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.

[Malaria and acute renal failure]

Neste artigo tenta-se evidenciar a malária, através do relato de um caso, como uma doença que pode afetar gravemente a função renal. Destacam-se também alguns pontos prioritários no tratamento de enfermagem.

Inhibition of antibody formation during continual stimulation with a strong immunogen

Long persisting antigenic stimulation at immunogenic levels leads to a profound inhibition of antibody formation. With Brucellus abortus, there is first a brief and high IgM response. IgG antibody titres remain at a low level for some days, and then begin a slow and progressive increase, leading to a rather persistent maximum, and finally after about 300 days, to the state of inhibition. When the same total dose is given with monthly intervals, the effect is quite different, with similar IgM and IgG peaks being observed after each dose. The inhibited animals respond moderately to a ten-fold higher antigen dose, and only with IgG. Six months after interruption of the persistent antigenic stimulus, a strong response can be obtained after a new antigenic stimulation, with a substantial proportion of IgM. It is concluded that persistent antigenic stimulation plays a major role in the change from IgM to IgG synthesis.