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Biomedical subjects

J Guerrero

Publications and source records attributed to J Guerrero.

At least 73 records · Page 4Linked to original sources
PubMed1983

Evaluation of the safety of flubendazole premix in swine.

Forty-eight pigs were used to evaluate the safety of flubendazole, given as a 6% rice-hull premix. In 1 experiment, flubendazole was administered orally to 16 pigs daily for 5 days at dosages of 10 or 20 times the recommended rate. In a 2nd experiment, flubendazole was administered in the feed to 18 pigs daily for 15, 16 or 17 consecutive days at dosages of 1, 3 and 5 times the recommended rate. The remaining 14 pigs received a placebo premix and served as controls. Clinical observations were made each day, and body weights and clinical laboratory values were monitored before, during and after the treatment period. In the 2nd experiment, all pigs were necropsied 1 day after the last day of treatment. Clinical signs during the experiments consisted of soft/fluid feces, observed in pigs from all groups, and occasional vomiting from 3 pigs in the group given the 3X-exaggerated dose. Statistical differences in the frequency of loose feces and vomiting were not detected between the placebo group and flubendazole-treated groups. There were no other abnormal signs noted throughout either experiment. Results of serum chemistry analysis, hematologic examination, and histopathologic evaluation revealed no evidence of drug-related toxicity.

Animals↗
PubMed1983

Activity of flubendazole against developing stages of Dirofilaria immitis in dogs.

A formulation of flubendazole was studied to determine the activity against developing stages of Dirofilaria immitis in artificially infected pups. Flubendazole suspension was administered subcutaneously at a dose rate of 50 mg/kg of body weight once a day for 1, 3, or 5 consecutive days at various times during the experimental period. The pups were necropsied 6 months after the experimental infection, and the heart and pulmonary arteries were examined for adult worms. Optimal activity was obtained when flubendazole suspension was administered subcutaneously for 5 consecutive days, either 1 or 2 months after infection. The formation of encapsulated deposits, containing white viscous fluid, was observed at the injection sites of all treated pups.

Animals↗
PubMed1983

Flubendazole: dose range and efficacy studies against common internal parasites of swine.

The anthelmintic spectrum of activity and efficacy of flubendazole, using pigs naturally infected with helminth parasites, were determined in 4 experiments, using 157 pigs. Flubendazole (1.5 mg/kg of body weight) mixed in feed or top-dressed on feed for 5 consecutive days was highly effective as an anthelmintic. This dosage level indicated 100% efficacy against mature Ascaris suum, Oesophagostomum dentatum, Trichuris suis, and Metastrongylus apri. There was 88% efficacy against Strongyloides ransomi and 85% efficacy against Stephanurus dentatus and immature Ascaris suum. There was some activity against Globocephalus sp and Macracanthorhynchus hirudinaceus, but insufficient numbers of these parasites were present to make an accurate assessment.

Administration, Oral↗
PubMed1982

Genetic and biochemical study of threonine-overproducing mutants of Saccharomyces cerevisiae.

Three threonine-overproducing mutants were obtained as prototrophic revertants of a hom3 mutant strain of Saccharomyces cerevisiae. The gene HOM3 codes for aspartokinase (aspartate kinase; EC 2.7.2.4), the first enzyme of the threonine-methionine biosynthetic route, which is subjected to feedback inhibition by threonine. Enzymatic studies indicated that aspartokinase from the revertants has lost the feedback inhibition, resulting in overproduction of threonine. These revertants also bore one or two additional mutations, named tex1-1 and tex2-1, which alone or jointly made possible the excretion of the threonine accumulated. The effect of these two genes on excretion is potentiated by excess inositol in the medium.

Aspartate Kinase↗
PubMed1982

The influence of verapamil on serum digoxin concentration.

The effect of verapamil on the pharmacokinetics of digoxin was studied in 49 patients with chronic atrial fibrillation. A dose of 240 mg/day of verapamil was given to the patients who were receiving a stable dose of digoxin. Serum digoxin levels rose from 0.76 +/- 0.54 ng/ml (mean +/- SD) to 1.31 +/- 0.54 ng/ml during verapamil treatment (p less than 0.0005). This effect was dose-dependent, as shown in seven subjects who received 160 mg and then, 240 mg of verapamil: There was a stepwise rise in serum digoxin concentration from a control value of 0.60 +/- 0.11 ng/ml to 0.84 +/- 0.18 ng/ml and 1.24 +/- 0.40 ng/ml, respectively (p less than 0.01 for both steps). The effect of verapamil developed gradually within the first few days in seven subjects in whom serum digoxin concentration reached, within 7 days, 90% of the increase observed 14 days after onset of verapamil. Renal digoxin clearance decreased significantly (26.1 +/- 0.7 vs 55.1 +/- 12.3 ml/min, p less than 0.005) in six patients in whom serum digoxin concentration increased. It did not change in one patient in whom serum digoxin concentration was not influenced by verapamil. Creatine clearance did not change in any of these seven. The same effects on digoxin clearance were observed in three normal subjects. Among the 49 patients, verapamil resulted in the development of signs and symptoms that suggested digitalis toxicity in seven. Verapamil significantly increased serum digoxin concentration. The process is dose-dependent and gradual, and it is at least partially explained by reduced renal excretion without reduction in glomerular filtration. The dose of digoxin may need readjustment in patients who are concomitantly receiving verapamil.

Adult↗
PubMed1982

Clinical use of oral verapamil in chronic and paroxysmal atrial fibrillation.

We evaluated the effectiveness of oral verapamil therapy for control of ventricular rate in digitalized patients with atrial fibrillation (AF) with three clinical problems: chronic AF with rapid rate at rest (four patients), chronic AF with accelerated rate during modest exercise (five patients), and rapid rates during paroxysmal AF (four patients). Patients in the first two categories were evaluated both by open-label dosage titration and by a randomized, double-blind, cross-over protocol. In chronic AF with rapid rate of rest, there was a significant reduction in resting heart rate (from 125 +/- 7 to 87 +/- 14, P less than 0.01) and in peak exercise heart rate (from 162 +/- 33 to 126 +/- 25, P less than 0.01). In chronic AF with rapid rate during exercise, there was also a significant decrease in resting heart rate (from 90 +/- 7 to 66 +/- 4, P less than 0.01) and in peak exercise heart rate (from 126 +/- 19 to 101 +/- 15, P less than 0.01). These effects continued during longterm follow-up of one to 12 months (mean seven months). In patients with paroxysmal AF, verapamil slowed the ventricular response from 16- +/- 24 to 72 +/- 4 P less than 0.01) with only some amelioration of symptoms. Therapy was well tolerated despite a high prevalence (seven of 13 patients) of radiographic cardiomegaly (cardiothoracic ratio greater than 0.55). We conclude that verapamil is a safe and useful drug for control of ventricular rate in digitalized patients with chronic and paroxysmal AF.

Administration, Oral↗
PubMed1982

[Fractionated bone marrow transplantation in a case of severe combined immunodeficiency].

Authors present a male infant affected by severe combined immunodeficiency with a high percentage of circulating B lymphocytes. Pathogenetic mechanism underlying our patient's disease seems to be an intrinsic defect in the lymphoid stem cell. As no histocompatible donor could be found, an hemiallogeneic bone marrow transplantation of maternal origin, fractionated with soybean agglutinin, was performed. The patient died 27 days after transplantation. At this time the percentage of T cells in his peripheral blood rose to near normal values, and the percentage of B cells normalized, karyotype analysis demonstrated circulating cells of female origin. Necropsy showed a spleen with lymphoid follicles and germinal centres but no signs of graft-versus-host could be found. Fractionated bone marrow could be of paramount importance in the treatment of these patients, since it could circumvent graft-versus-host disease.

Adult↗
PubMed1982

Anthelmintic activity of closantel against Ancylostoma caninum in dogs.

The efficacy and minimum therapeutic dose of closantel, an injectable salicylanilide anthelmintic, was evaluated on adult Ancylostoma caninum. Doses of 7.5 and 10 mg/kg had a marked anthelmintic effect on adult stages, removing 99 and 98%, respectively. A second experiment tested the efficacy of closantel against hypobiotic larval stages of A. caninum. A dose of 20 mg/kg did not affect the abundance of arrested hookworm larvae or prevent their subsequent development, but it may have inhibited their full maturation as adult worms so that patent, intestinal infections did not occur. Small numbers of adults were recovered from treated dogs at 29, 43, and 57 days post-treatment, but no eggs were passed in their feces. These studies bear on the practical problem of control of hookworms in dogs.

Ancylostoma↗
PubMed1981

[Kidney and osseous responsiveness to PTH in a case of pseudohypoparathyroidism (author's transl)].

A case of pseudohypoparathyroidism is described, finding in addition to the typical clinical data described in the literature an all almost total atrophy of the minor lips and clitoris, a perforated hymen and a "paradoxical" increase of convulsions with anticomicial treatment. Study of response of urinary phosphates and AMPc to PTH, was negative (Drezner type I). Osseous response to PTH was negative (Frame type I pseudohypoparathyroidism). Pathogenic possibilities are discussed.

Anticonvulsants↗
PubMed1981

Comparative anthelmintic efficacy of two schedules of mebendazole treatment in dogs.

Two schedules of anthelmintic oral treatment, using mebendazole powder, were compared in 73 dogs naturally infected with common helminth intestinal parasites. Mebendazole powder was administered to 26 dogs at doses of 22 mg/kg once daily for 3 days and was compared with the same dose given only daily for 5 days into 23 dogs. The 24 other dogs were kept as controls and received a placebo treatment for 5 days. Efficacy results for the 3-day treatment schedule of mebendazole were as follows: Toxocara canis, 100%; Uncinaria stenocephala, 100%; Ancylostoma caninum, 99.4%; Trichuris vulpis, 100%; and Taenia pisiformis, 93.9%. Mebendazole powder given on the 5-day treatment schedule was 100% efficacious against the foregoing parasites. Anthelmintic efficacy against Dipylidium caninum was not detected in either schedule of treatment.

Administration, Oral↗
PubMed1981

Pilot trials on the treatment of Dermatobia hominis infections in cattle with closantel.

The therapeutic and prophylactic activities of closantel given to calves inoculated with larvae of Dermatobia hominis were studied. Calves (n = 9 principals, plus 3 nontreated controls) were given closantel at different dosages (8 to 12.5 mg/kg) and schedules of treatment. The largest dosage of closantel (12.5 mg/kg) had the most efficacious therapeutic activity (97.3%). Prophylactic activity was also seen in calves given the drug before they were experimentally inoculated.

Animals↗
PubMed1981

Anthelmintic activity of mebendazole against induced and naturally occurring helminth infections in cats.

A formulation of mebendazole was used to determine the optimal dosage level against induced and/or naturally occurring infections of Toxocara cati, Ancylostoma tubaeforme, and Taenia taeniaeformis in cats. Amounts of 11 mg/kg of body weight/day or 22 mg/kg/day were given for 2, 3, or 4 days. Feces were collected for 7 days and were examined for expelled parasites. Cats were necropsied to recover retained parasites. A regimen of 22 mg/kg/day for 3 days was determined to be optimal with efficacies of 100%, 99%, and 50% against T cati, A tubaeforme, and Taenia taeniaeformis, respectively.

Ancylostomiasis↗
PubMed1979

[Urea half-live as index of renal failure in hypertonic dehydration (author's transl)].

Evolution of uremic half-time in 27 infants with hypertonic dehydration is studied. Authors establish three groups in accordance with duration of uremic half-time: 1st: less than 24 hours: 5 infants. 2nd: More than 24 hours without renal or uremic pathology: 12 infants. 3rd: More than 24 hours with renal or uremic pathology: 10 infants. Utility of this parameter is discussed, as well as its physiologic bases. The existence of 2nd group makes the value of this control as an organic of functional renal index uncertain.

Acute Kidney Injury↗
PubMed1978

Experimental muscular amebiasis in hamsters as a biological model.

Trophozoites of Entamoeba histolytica maintained in vitro in Pavlova's medium were inoculated by deep intramuscular injection into the proximal left hindleg of hamsters. Thioglycollate medium was utilized as a successful vehicle to induce the infection. The invasion of the muscular tissue by the vegetative forms caused the formation of abscesses with great destruction of muscular fibers. The lesions were limited to the muscular tissue of the femoral area. The number of trophozoites, the medium of thioglycollate as a vehicle, the volume of the inoculum and the trauma caused by the needle were important elements in the evolution of the muscular amebic abscesses. A limited trial of the amebicidal activity of metronidazole utilizing the amebic intramuscular infection was also performed.

Abscess↗
PubMed1978

Normotensive hyperreninemia in systemic lupus erythematosus. An indicator of tubular dysfunction.

High plasma renin activity (PRA) was found in 16 of 42 randomly selected nonuremic systemic lupus erythematosus (SLE) patients. Mild hypertension was present in 3 of the 16.6 high-PRA and 10 normal-PRA patients were admitted to a metabolic ward. Salt restriction produced a disproportionate rise in both PRA and aldosterone, a decrease in glomerular filtration rate (GFR) and a slightly greater negative sodium balance in the group with high PRA. Potassium excretion was less than intake in both groups. Balance studies were performed in 6 additional high-PRA patients before and during indomethacin administration (150 mg/24 h). PRA and aldosterone were markedly suppressed by indomethacin. UnaV was significantly greater than in the control period despite of the 28% reduction in GFR. These results suggest that high PRA is secondary to impaired distal tubular sodium reabsorption. Such a defect could be responsible for the relatively low frequency of hypertension in lupus nephritis.

Adolescent↗