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Habituation to sound stimulation was analyzed in terms of the functional role of the telencephalon in learning. Sixteen pigeons were exposed to 1000-Hz, 83-dB, 1-s sound (stimulus A) at 30-s intervals until there was habituation of the exploratory and pre-exploratory responses. The learning criterion was 10 trials without the occurrence of these responses. Twenty-four hours after habituation to stimulus A the birds were tested with a 500-Hz, 85-dB, 1-s sound (stimulus B). On the day following habituation to stimulus B, the birds of the experimental group (N = 8) suffered ablation of the telencephalon and the birds of the control group (N = 8) had sham surgery. Retesting with the same sequence of procedures was carried out 10 days after surgery. In the POST-lesion situation there was a decrease of the number of habituation trials to stimulus A (P less than 0.01) and to stimulus B (P less than 0.05) by experimental pigeons compared to the PRE-lesions situation. The data suggest an interaction of a facilitatory effect of the lesion and long-term learning effects.

1. The clearance of plasma kallikrein by the isolated and perfused liver of rats chronically intoxicated with ethanol was studied. Alcohol was added to the diet as 36% of total calories, and the animals were kept on this diet for 5-7 weeks. 2. The hepatic clearance of plasma kallikrein by these rats (uptake half-life, 15 +/- 2 min; N = 3) was similar to that observed in the control groups (normal diet, uptake half-life, 14 +/- 2 min; N = 5, or normal diet with sucrose added as 36% of total calories, uptake half-life, 16 +/- 3 min; N = 4). 3. These results provided indirect evidence that the endocytosis mechanism of plasma kallikrein by the liver differs from that described for glycoproteins which use the galactosyl receptor, since liver endocytosis via this latter system is reduced by chronic alcohol intoxication.

To evaluate quali-quantitatively ischemic liver injury due to acute cardiocirculatory failure (ischemic hepatitis), and its real clinical signification, 200 out of 1165 autopsy records with ACF clinical diagnosis were selected; 33/200 (16.5%) shown centrilobular necrosis without inflammatory component, accompanied or not by midzonal compromise. Grade IV centrilobular necrosis (50-100% involved lobules) was present in 96.9%, with 15.5% associated midzonal pattern, and 21.2% of confluent type; 2 additional cases with isolated midzonal necrosis (5.7%) were seen. Only six patients (3.0% of ACF patients, and 18.2% of those with histological injury) shown overt clinical liver disease, one of them with a fulminant hepatitis picture (0.5% of ACF, and 3.0% of patients with ischemic necrosis). Bilirubin levels were 3.4-10.2 mg%, and aminotransferases rose up to 540 times over their seric superior normal limits. Centrilobular necrosis involved 100% of lobules in all cases.

During the year 1976, 18 patients intoxicated with lomotil were admitted to the Emergency Service of the Centro Medico La Raza, I.M.S.S. with ages fluctuating between 4 months and 3 years; the average age was 22 mos. 88.8% of intoxications were accidental. Initial manifestations of atropinism and diphenoxylate showed the same proportion and 22% showed mixed symptoms. There were no deaths. All patients were given stomach washings and it was seen that the earlier the washing was given, the lesser the symptoms showed. The specific treatment given was with naloxone chloride (Narcanti) at a dose of 10 micrograms, per kilo and per dose intravenously and was repeated as often as necessary. Response was spectacular with improvement within 15 seconds. No patient showed side-effects to the application of the antagonist. Lomotil intoxication rated up to 15% of the total sum of intoxications admitted.

Plasma levels of protein C (enzyme immunoassay), albumin (electrophoresis), and transthyretin (radial immunodiffusion) were measured in 15 patients with the compensated hepatosplenic form of schistosomiasis and in 10 healthy volunteers. Plasma levels of protein C were below normal in 47% of the schistosomiasis patients; this deficiency could be explained by diminished hepatic synthesis since it occurred in conjunction with low plasma levels of albumin and/or transthyretin. In 33% of the schistosomiasis patients, plasma levels of protein C were below 0.5 U/ml, a value which has been associated with thrombotic disease. Protein C deficiency may explain the unexpectedly low incidence of hemorrhagic episodes, as well as the occurrence of portal vein thrombosis that is not infrequent in these patients.

Eight patients with Klippel-Trenaunay-Weber syndrome were treated for leg length inequality of as much as 10 cm in one ten year old, and one thirteen year old. In most cases adequate correction was achieved with epiphyseal stapling during active growth or definitive epiphysiodesis in older children. Bone shortening procedures in full-grown individuals may be indicated but the basic condition may make healing difficult. Ligation of the femoral artery had no effect on the growth of the affected leg.

We report the clearance of rat plasma kallikrein (RPK) by the perfused livers of normal rats and from others at 2 and 4 days after subcutaneous injection of turpentine oil. RPK removal from the perfusate follows a logarithmic curve (y = a+b lnx) and from this equation its half-life of removal can be calculated. RPK clearance rate followed the potential equation y = axb. Both the half-life of RPK removal and RPK clearance rates were similar in the 3 groups of perfused livers. We conclude that, at the initial concentration of RPK used (approximately 3 nM), its liver clearance is not affected during the acute-phase response to inflammation.

Based on a series of macroscopic and histological observations, during an annual cycle, the main stages of oogenesis in Bufo arenarum (Hensel) have been recognized, pointing out the most significant features. The analysis has established five characteristic stages which permit the individualization of the maturation stage of the oocyte in the ovary. All the information obtained has provided the possibility of drawing up a synthetic table so that the oogenetic stages of this amphibian species, very much used in Argentine experimentation, could be easily recognized.

1. The medaka (Oryzias latipes), a small aquarium fish, was shown to possess the capacity to rapidly activate AFB1 in vivo at 25 degrees C to intermediates that bind to DNA. 2. The dose-response for in vivo AFB1-DNA binding was linear over the range 70-550 micrograms AFB1/kg body weight. 3. Maximum binding occurred within the first 24 hr after i.p. injection of [3H]AFB1, followed by a rapid loss of adducts. 4. Aflatoxicol (AFL) and unreacted AFB1 were found by HPLC analysis to be the major products excreted into water after AFB1 exposure, with excretion of AFL as early as 2 min after AFB1 injection. 5. These studies show that medaka possess enzymatic systems similar to rainbow trout (Salmo gairdneri) for biotransformation of AFB1 to the epoxide and to other phase I and phase II metabolites.

Serial cytogenetic studies have been performed in four patients with myelodysplastic syndromes. In all four a 5q- alteration was present, but with a different pattern of presentation. One patient presented 5q- as the only alteration since diagnosis; two patients acquired this alteration during the course of the disease; and the fourth showed a 5q- plus other alterations since the first cytogenetic study. Likewise, three of the four patients showed a clone with trisomy 8 and without 5q-. According to these observations and others from the literature with similar cytogenetic behavior, we have analyzed the following points: 5q- as a primary event and as the only alteration, 5q- as a secondary event, 5q- plus other alterations, and presence of cytogenetically different clones. Analysis of these points suggests that the 5q- alteration can represent an early mutation conferring a slow capacity of expansion to the affected clones, with the possibility of cytogenetic evolution during the progression of the disease (about 30% of the patients). Likewise, the association of trisomy 8 clones with 5q- clones can be a nonrandom event.

The clinical usefulness of bleomycin is limited by pulmonary toxicity. Recent clinical observations indicate that the pulmonary toxicity is potentiated in patients who are exposed to elevated but nontoxic concentrations of O2. We studied the interactions of O2 and bleomycin using a murine model. Mice were divided into two groups. One group was continuously exposed to 40% O2 at 1 atmosphere while the other group breathed compressed room air. The elevated O2 concentration alone was not toxic to animals. Mice in each group received either 40 mg/kg of bleomycin or normal saline twice a week sc. Median survival of mice receiving bleomycin was shortened from 8.24 to 4.35 weeks when the animals were maintained on 40% O2 (P = 0.0001). We conclude that exposure to a nontoxic but elevated O2 concentration can potentiate the toxic effects of bleomycin.

The authors measure the concentration of urea and arginase activity at pH 6.5 and 9.7 in the rat liver at intervals during the administration thioacetamide (TAM) at a dose of 50 mg per kg of body weight and per day. The values obtained correlate the amount of urea and the arginase activity at pH 6.5 and 9.7 during TAM administration for the intervals comprised between 1-12 days and 12-30 days. These results suggest that the concentration of liver urea depends mainly of the level at arginase activity, which is regulated by the proton concentration of the internal environment.