Showing papers by "Universidade Federal de Minas Gerais published in 1973"

Serrated flow in aluminum 6061 alloy

Abstract: An investigation of serrated flow in 6061 aluminum alloy at room temperature has been made using photoelastic coatings with emphasis on two basic types of serrations. This has shown that Type A serrations are associated with Luders bands that travel (in an ideal case) the length of the gage section under an increasing load. Secondary serrations in this type of deformation are due to disturbances in the propagation of the Luders front. The rising load during propagation of the Type A Luders bands is associated with a change in the gage section strain gradient that occurs at the end of “homogeneous” deformation. Type B serrations involve bands that move only during the load drop. The effect of machine stiffness on the deformation accomplished by Type B bands is also considered.

Isolamento e identificação dos agentes da cromomicose em Belo Horizonte

Abstract: Foram feitos o isolamento e a identificacao dos agentes etiologicos da cromomicose, atraves do estudo macroscopico e microscopico das colonias. O fungo Fonsecaea pedrosoi foi isolado do material dos quatro casos estudados.

Spinal cord complications of acute schistosomiasis mansoni.

Abstract: 5 cases of clinically unsuspected involvement of the spinal cord by S. mansoni are reported. In contrast to the cases usually described in the literature, the nervous system involvement was observed during the acute phase of the infection. One of the patients exhibited a clinical picture closely resembling that of the Guillain-Barre syndrome, and cure was not dependent upon the use of corticoid hormone or antischistosomal therapy. 2 other patients improved after neurological involvement (paraparesis and paraplegia) following the completion of specific treatment (hycanthone). The sudden appearance of a polyradiculoneuritis syndrome was observed in 1 patient during treatment with niridazole. In another patient who developed a sudden transverse myelitis at T.11 with flaccid paraplegia, antischistosomal therapy apparently did not influence the course of the neurological process. It is suggested that the nervous system involvement in the reported cases cannot be explained entirely by the mechanical action of eggs and worms and the resultant granuloma formation. In the authors' opinion an anomalous response of the nervous system to the immuno-allergic products derived from dead worms and; or their eggs probably was responsible for the clinical manifestations of spinal cord involvement.

Increase of kinin in urine after partial occlusion of the renal vein and the effect of bradykinin on renal sodium excretion.

Abstract: A partial renal vein occlusion of one kidney, in hydropenic dogs, increases around twenty times the oxytocic activity of the urine from this kidney while in the urine from the control kidney the activity remains unchanged. This activity does not appear in urine by filtration because the glomerular filtration rate is significantly reduced by the vein occlusion. A partial occlusion of the renal artery does not increase the activity of urine. Through filtration on Sephadex LH-20 two fractions of activity in urine are obtained. The first peak appears in the same position as a standard of bradykinin appears. The second peak appears in the same position as a standard of antidiuretic hormone does. The samples of the first peak relax the rat duodenum and contract the rat uterus, the rat ileum and the guinea-pig ileum. They produce hypotension in rats and they maintain the activity after incubation with sodium thioglycolate. The activity is destroyed by chymotrypsin. As bradykinin may play a physiologic role in the regulation of renal sodium excretion, the effect of synthetic bradykinin on sodium excretions was studied in dogs using the stop-flow method (Malvin, R.L., et al. [4]). It was observed that bradykinin decrease the proximal tubular reabsorption of sodium and water but does not alter the capacity of the distal part of the nephron to lower the intratubular concentration of sodium. It was also observed that bradykinin decreases the proximal tubular secretion ofp-aminohippuric acid.

Tratamento microcirúrgico de aneurismas da artéria comunicante anterior

Abstract: The surgical treatment of eight patients who had spontaneous subarachnoid hemorrhage from ruptured anterior communicating aneurysms is reported. The pre-operatory treatment is described, with emphasis to the patients condition before surgery. The surgical technique is described with special reference to the use of binocular microscope. Two patients (25%) had multiple aneurysms which were treated at the same operation. Meningitis was a complication on one patient but subsided with antibiotic treatment. After the operation 88% of the patients returned to their primitive jobs and there was no death related to the surgical treatment. Comments on other procedures for the surgical treatment of anterior communicating aneurysms are made.

Experiments with input-output analysis at the regional and local level

Abstract: This paper uses input-output analysis to study some aspects of of growth pole theory with special reference to the role of a propulsive firm in the development process of a growth pole in the State of Minas Gerais (Brazil). The empirical results of three simple linear models related to a very detailed input-output table built for that growth pole are analysed. In its first part, the results of a comparison between the production structures of the State and those of the country are also shown to emphasize once more that we should be very careful in using national technical coefficients when studying the economies of areas in a country with large regional growth disparities.

Attempts to isolate a kallikrein inhibitor from rat salivary gland

Abstract: Besides the oxytocic principle (kallikrein) it was possible to separate from the rat submandibular gland extract an inhibitor presenting a specific antagonism against the oxytocic action of the submandibular gland kallikrein.

Bradykinin-potentiating activity in human serum

Abstract: It was found in the euglobulin fraction of the human blood a potentiating principle which increases the bradykinin-induced contraction of isolated rat uterus and guinea-pig ileum. This fraction was prepared according to Lepow et al. [1]. One volume of fresh human serum was added to 8 volumes of acetate buffer pH 5.5, ionic strength 0.02, at 1°C. The mixture was allowed to stand overnight at 1°C and the precipitate was centrifuged at 2000g for 30 minutes at 1°C and washed with acetate buffer, pH 5.5, ionic strength 0.02. The washed precipitate was suspended in 0.5M NaCl to one-tenth the original volume of serum and centrifuged cold at 78,000g for 60 minutes. The particles of lipid were removed by filtration in glass wool and the filtrate was dialyzed at 1°C vs. 50 volumes of pH 7.4 phosphate buffer, ionic strength 0.15. The resulting opalescent solution, concentrated 10-fold with respect to serum, was applied to a DEAE-cellulose column. The bradykinin potentiator was found in the first protein peak, together with the unadsorbed proteins. In order to make the correspondence between the bradykinin-potentiator and the complement system, the human euglobulin was applied to a DEAE-cellulose column eluted with sodium phosphate (starting buffer) pH 7.4, ionic strength 0.15 and containing 10−3M NA3 HEDTA. This chromatography showed the three activities of the first component of human complement (C1q, C1r and C1s) and the bradykinin-potentiator was found in the protein peaks containing C1q and C1s activities. The bradykinin-potentiating principle is destroyed by heating at 97°C, unstable on pH lower than 4.0 and over 9.5, and it is not dialysable. This last property makes it different from human fibrinopeptide A-β (Osbahr et al. [3]) and from human plasma bradykinin-potentiating factor (Louhija and Sipila [2]).

Anomalias em conchas de Biomphalaria straminea (Dunker, 1848), criadas em laboratório. (Pulmonata, Planorbidae)

Abstract: Assinala-se o encontro de anomalias em conchas de 90 especimens de Biomphalaria straminea, traduzidas por acentuada deformacao da ultima espiral. Os exemplares pertencem a populacao criada em laboratorio e procedente de Curvelo, Minas Gerais, Brasil.

Cardiovascular and respiratory changes during acute pulmonary edema produced by nephrotoxic serum in the rat.

Abstract: The intravenous injection of rabbit anti-rat kidney serum in rats produces, with a latency of 30 to 60 seconds, the triad sinus bradycardia (or S-A blockade), systemic hypotension and apnea. Recordings of the intracardiac pressures showed a rise in the right and a simultaneous fall in the left ventricular pressure, 30 to 60 seconds after the serum injection. These initial effects were followed by pulmonary edema and death. Bilateral vagotomy prevented the bradycardia and apnea, but not the intracardiac changes, edema and death. Atropine also prevented the bradycardia, but not the apnea, edema and death. Experiments using alpha and beta adrenergic blocking agents seem to indicate that the edema is not caused by the release of catecholamines. It is suggested that the edema could be explained by a rise in the pulmonary capillary pressure, due to the antigen-antibody reaction. The triad bradycardia, systemic hypotension and apnea seems to be the first sign of the pulmonary edema, is reflex in nature, and is assumed to be due to stimulation of J receptors in the lungs, by a mechanical effect (edema). Phenylbutazone and acetylsalicylic acid give a partial protection against the pulmonary edema. Ultramorphological observations of lungs with edema were described.