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C Velasco

Publications and source records attributed to C Velasco.

44 records · Page 3Linked to original sources
PubMedDate not supplied

Effect of 5-HT1A receptor antagonists on citalopram-induced increase in extracellular serotonin in the frontal cortex, striatum and dorsal hippocampus.

The aim of the present study was to compare the effects of citalopram, either alone or combined with 5-HT1A receptor antagonists, on extracellular serotonin levels in brain regions innervated by the dorsal or median raphe nuclei. Using intracerebral microdialysis in awake rats with separate probes in the frontal cortex or dorsal hippocampus, we studied the ability of 8 mg/kg s.c. (-)penbutolol, a beta-adrenoceptor antagonist with antagonist action at 5-HT1A and 5-HT1B receptors, and 0.3 mg/kg s.c. WAY-100635, a selective 5-HT1A receptor blocker, to modify the effect of 1 and 10 mg/kg i.p. citalopram on extracellular serotonin. Both doses of citalopram had more effect on extracellular serotonin levels in the dorsal hippocampus than in the frontal cortex. The effect of 1 mg/kg citalopram was significantly potentiated by (-)penbutolol in the frontal cortex only, but a clear-cut potentiation of the effect of citalopram was seen in both regions at a dose of 10 mg/kg. The effect of 10 mg/kg citalopram was potentiated by WAY-100635 in the frontal cortex but not in the dorsal hippocampus. In a second set of experiments, the combined effect of WAY-100635 and citalopram was studied in the same rat implanted with vertical probes in the striatum and dorsal hippocampus. Citalopram (1 and 10 mg/kg i.p.) raised extracellular serotonin to a similar extent in both regions. However, 0.3 mg/kg s.c. WAY-100635 potentiated the effect of 10 mg/kg citalopram in the striatum but not in the dorsal hippocampus. The results suggest that only a combined blockade of 5-HT1A and 5-HT1B receptors potentiates the effect of citalopram on extracellular concentrations of serotonin in the dorsal hippocampus. The findings may be relevant in designing clinical trials aimed at enhancing the antidepressant action of selective serotonin re-uptake inhibitors by combining them with serotonin receptor antagonists.

Animals↗
PubMedDate not supplied

Influence of pump compliance (peristaltic vs. infusion) on urodynamic measurement during cystometry in conscious rats.

Cystometry, employing natural or pump-induced bladder filling, is the most widely used method for studying bladder reflexes and micturition in conscious rats. However, discrepancies in basal values of urodynamic parameters are often reported, especially for micturition pressure. The aim of this study was to establish whether the type of pump used (peristaltic or infusion) might yield different urodynamic parameters. Differences between natural filling (evaluated in water-loaded animals and considered "physiological micturition") and pump-evoked cystometrograms, as well as the compliance of these systems, and the effects of pharmacologically diverse drugs (prazosin, oxybutynin, and naproxen) acting on the bladder voiding were evaluated. Micturition pressure recorded from pump-evoked cystometrograms showed differences from natural micturition that were related to the total compliance of the system (pump + tube) and not only to the nature of the pump used. Drug-induced changes of micturition pressure during natural micturition resembled those recorded during bladder infusion with a peristaltic pump more than those with an infusion pump. Other basal values and drug-induced changes of bladder capacity were the same during natural and pump-evoked micturition. The present findings indicate that cystometrographic parameters obtained during pump-evoked micturition with a system at high compliance (peristaltic pump) are equivalent to those observed during physiological micturition.

Animals↗
PubMedDate not supplied

[Blood transfusion from cadavers].

Most of the transplant programs in our days are based on cadaveric donation; blood has been not recovered from dead bodies, except by some Soviet groups. We selected 16 subjects, eight with brain death and eight with "biological" death (heart arrest) that were considered as ideal donors. From them we obtained 23 units of whole blood, either by surgical dissection of the internal jugular vein, by puncture of the femoral artery or by puncture of a peripheral arm vein. Twelve were not used due to bacterial growth, HBsAg positivity or hemolysis. Of the remaining, we obtained 10 packed red cells and 10 units of plasma, one unit was transfused as whole blood. Three plasma units were discharged due to "turbidity". Sixteen patients for whom it was difficult to get a voluntary donor were transfused with some of the products and followed for as long as they remained in hospital. None showed adverse reactions due to the procedure. We conclude that the organization of any program related to the transplantation of organs is not a simple matter, but that blood is easily recovered and that this should be done always as part of the "total use" of a donating body; cadaveric blood transfusion is harmless provided donors are carefully selected and that the sterility of the product is confirmed by culture.

Adolescent↗
PubMedDate not supplied

[Ataxia telangectasia. Probability of damaging immune mechanisms].

Twelve patients suffering from ataxia telangiectasia and relatives of three of them were studied. A late diagnosis prevailed and the neurological symptoms in some turned worse after suffering recognizable viral infections. The cellular and humoral immunodeficiencies were evaluated in each case as well as the simultaneous presence of hyperimmunoglobulinemia and/or auto-antibodies. Among the relatives, there were frequent cases of immunological and neoplastic alterations; cellular immunodeficiency was not detected. Five cases showed lung disease; four with absence of IgA, and histologic interstitial lesion detected in three of them. The hypothesis that the defect of cell immunity predisposes mulisysthemic disease and that an early diagnosis with immune reconstructive treatment can modify the evolution of the disease was considered.

Antibody Formation↗
PubMedDate not supplied

[Identification and treatment of coronary atherosclerosis, before resection of abdominal aortic aneurysm].

Atherosclerotic aortic aneurysm, is frequently associated to coronary atherosclerosis. When myocardial ischemia is asymptomatic, aortic surgery commonly is deferred because unexpected ischemic cardiopathy. To diminish the risk of aortic surgery, aortocoronary bypass must be installed before the aortic graft. Percutaneous transluminal coronary angioplasty is an alternative treatment of coronary atherosclerosis, principally in elderly patients. We present the case of a male patient with an abdominal aortic aneurysm and myocardial silent ischemia secondary to right coronary artery stenosis treated by mean the percutaneous transluminal coronary angioplasty (PTCA) before aortic surgery, with the objective of decreasing surgical risk and its possible complications (myocardial infarction, cardiogenic shock, death, etc.). Nine months after the PTCA, the patient is asymptomatic and stress test on treadmill is negative.

Aged↗