Showing papers by "University of São Paulo published in 1968"

Chagas' disease and Chagas' syndromes: the pathology of American trypanosomiasis.

Abstract: Publisher Summary Chagas' disease-like all really great and important discoveries-has its own and very peculiar history, called by Magalhaes , a “tragicomedy, which embittered and destroyed the life of one of our greatest compatriots”. In this history it is useful to distinguish the following six periods. Chagas in 1908 discovered in the intestine of the blood-sucking triatomas that were common in the primitive huts of the Brazilian hinterland, an unknown trypanosome, which was named by “Schizotrypanum cruzi.” The presence of this parasite in bugs suggested to him the possible existence of an infectious disease in animals and man. Soon afterwards Chagas also found the parasites in the blood of domestic animals (dogs and cats) and in the blood of a sick child with a high temperature. The discovery of American trypanosomiasis by Carlos Chagas represents one of the most fascinating events in the history of medicine. It is almost incredible that such severe pathological manifestations, which represent the “causa mortis” of one third of our autopsy material, would have been overlooked or unknown before Chagas' unique discovery. American trypanosomiasis shows a very peculiar pathology of homeostasis of the human organism, and represents even today a new realm in pathology, which becomes understandable through Cannon's law of denervation.

Physiological, Morphological and Behavioural Adaptation to a Sodium Deficient Environment by Wild Native Australian and Introduced Species of Animals

Abstract: Native Australian and introduced species of animals are adapted to severe sodium deficiency. Effects of such a deficiency are aggravated by pregnancy and lactation, and it has been shown that mechanisms controlling sodium homeostasis in wild rabbits are subject to profound stress.

Effects of acute elevation in blood pressure and of atropine on heart rate in Chagas' disease. A preliminary report.

Abstract: Degeneration of the parasympathetic ganglia in the heart and in the smooth muscle (esophagus, colon, and bronchi) is known to occur in Chagas' disease. The reflex bradycardia associated with acute elevation in systemic arterial pressure and the blocking of this reflex effect with atropine are used in this investigation to study vagotonic influences on the heart in patients with Chagas' disease. Failure to increase heart rate following administration of atropine observed in cases of chronic Chagas' heart disease is believed to be a functional disorder related to degeneration of the neuronal supply to the sino-atrial region of the heart. To the authors' knowledge this report provides the first existing physiological investigation concerning the cardiovascular system in Chagas' disease.

The relaxing effect of bradykinin on intestinal smooth muscle

Abstract: Bradykinin has been found to be a potent stimulant of the adrenal medulla (Lecomte, Troquet & Dresse, 1961; Feldberg & Lewis, 1964) and sympathetic ganglia (Lewis & Reit, 1965). This effect seems to be caused by an interaction of the polypeptide with non-nicotinic receptors in ganglionic synapses (Trendelenburg, 1966) and could explain the potentiation of the hypotensive (Rocha e Silva, Corrado & Ramos, 1960; Lloyd, 1962; Nakano, 1965) and bronchoconstrictor (Collier, James & Piper, 1965) actions of bradykinin by adrenergic blockade or by adrenalectomy. It was of interest to know whether some \" sympathomimetic\" effects of bradykinin observed in isolated preparations could also be explained by a release of catecholamines; the weak cardiostimulant action of bradykinin on the isolated guinea-pig heart has been shown to be direct and not the result of a local release of catecholamines or an interaction of the polypeptide with adrenergic receptors (Antonio, 1966). In this investigation the relaxation of the isolated rat duodenum was studied, as another effect of bradykinin which resembles sympathetic stimulation. The duodenum was subjected to different ionic environments in an attempt to investigate how such relaxation is produced; epinephrine and papaverine were used for comparison.

Plankton studies in a mangrove environment: V. salinity tolerances of some planktonic crustaceans

Abstract: The salinity tolerances of adult females of some relevant species of planktonic copepods were studies in a mangrove region of the estuarine type, at 25o south latitude. Results showed a wide range in the salinity tolerances for the adultfemales of all the species studied. Based on these experiments the following order of salinity tolerance can be proposed: Pseudodiaptomus acutus > Euterpina acutifrons > Acartia lilljeborgi > Oithona ovalis > Centropages furcatus > Temora stylifera. A mechanism for the maintenance of Pseudodiaptomus acutus at certain regions of the area studied is proposed, based on experimental and field results. It seems probable, thus that salinity is an important factor in the distribution of some members of the zooplankton in this region.

Distribution and annual occurrence of Chaetognatha off Cananeia and Santos coast (São Paulo, Brazil)

Abstract: Plankton samples were fortnightly taken at three fixed stations off Cananeia (1958, 1959, 1960) and off Santos (1960, 1961) by vertical hauling. They contained the following species: Sagitta enflata, S. friderici, S. hispida, S. minima, S. serratodentata, Krohnitta pacifica and Pterosagitta draco. S. frideriei is a typical coastal water species. S. enflata is a typical shelf water species. S. hispida and K. pacifica were present more frequently in shelf water but they were sometimes very abundant in coastal water. S. serratodentata, S. minima and P. draco occurred sparingly in tropical water, however, very few samples were taken in this water mass. Three different maturity stages were established (juvenile, intermediate and adult) in order to study the annual variation of the Chaetognatha. A special breeding period throughout the year was not observed as great swarms of juveniles and intermediates were found in spite of the very small number of adults. Two series of samples taken off Santos at a fixed station (Pt. III) during a period of 24 hours in three different levels were also counted to study the vertical distribution of the Chaetognatha in this area. The three most abundant species were: S. enflata, S. hispida and K. pacifica. S. enflata was more frequent at mid-water. S. hispida and K. pacifica seemed to prefer the surface layer. The thermocline did not affect their vertical migration except for S. hispida. There is indication that S. serratodentata performs vertical movements. S. minima seems to live below 25 m depth. K. subtilis occurred exceptionally in this vertical series of samples.

Recombination in Drosophila willistoni.

Abstract: KNOWLEDGE of Drosophila genetics was acquired mainly through work on Nearctic species. Conclusions reached from studies of these species are frequently extended to those of other regions. Biological generalisations are hazardous especially when they involve adaptive characters of organisms living under different conditions. This is especially true for genetic systems which, owing to their crucial adaptational importance, must be highly sensitive to natural selection. The comparative analysis of the genetic systems of related species living in different environments is necessary before generalisations can be made and this is one of the ways of understanding their adaptive meaning and evolutionary origin. Recombinant chromatids produced by crossing-over within relatively inverted segments are eliminated. Data obtained in Nearctic species of Drosophila show that heterozygous inversions also suppress effective crossing over outside the inverted segments. This is well known for inversions like Payne and Curly of D. melanogaster and for inversions in D. pseudoobscura, .D. persimilis, D. virilis and particularly of D. robusta (review in Carson, 1953). No recombination was found by Carson (1953) within or between two heterozygous inversions in opposite arms of the second chromosomes of D. robusta and separated by a distance corresponding to 376 per cent, of the chromosome length. Similar results were obtained for inversions in the X chromosome. On the basis of results obtained with Nearctic species, it is generally believed that there is no crossing over at spermatogenesis in Drosophila. The absence of crossing over in D. melanogaster males has been well known since Morgan's work (1914), which has been confirmed by many authors. Patterson and Suche (1934), for example, found only one recombinant among 8329 third chromosomes marked from tip to tip with eight recessive

Effects of Catecholamines on Rat Mesentery Mast Cells

Abstract: THERE have been reports of results which suggest in vivo or in vitro release of histamine caused by adrenaline or noradrenaline in the rat1,2 and other species3–5, but these reports are not wholly accepted as conclusive evidence6,7. As well as amine release, degranulation of mast cells is one of the activities of most histamine releasers active on rat tissues. This communication presents the results of a study of the effects of catecholamines on the morphology of the rat mesentery mast cells, undertaken to provide further information about the effect of catecholamines on a histamine storage site in the mesentery.

Ebstein's disease. Electrovectorcardiographic and radiologic correlations.

Abstract: The electrocardiograms and vectorcardiograms of 12 patients with Ebstein's disease are analyzed and correlated with the radiologie findings. In 6 patients, there was anatomic confirmation, in 3 during surgery for implantation of a Starr-Edwards prosthesis in the right atrioventricular ring and in 3 by autopsy. In the 6 remaining patients, the confirmation was made by angiocardiographic studies. A tendency to normal heart rate or bradycardia was observed in most cases. In all, the diagnosis of right atrial overloading could be made by analyzing the amplitude, configuration and durations of the P wave and P-R interval. The duration of the P wave was greater than normal in 53 per cent of the cases. The duration of the P-R interval was greater than normal in 73 per cent of the cases. There was a clear relation between the increased duration of the P wave and that of the P-R interval. The increases of the P wave and of the P-R interval were closely related to the increase of the cardiac silhouette. The P/P-R segment index was less than 1.2 (considered the mean normal value), in spite of the increase of P wave duration, in all but 1 case. We support the hypothesis that the increase in P wave and P-R interval is dependent mainly on right atrial overloading and not only on congenital conduction disturbance. In the patients with very large hearts, lead V1 tended to show polyphasic, low voltage QRS complexes, whereas in those with smaller hearts, V1 tended to show “pure” R waves. An increase in QRS duration was registered in all cases, probably not because of real right bundle branch block but because of intraventricular conduction disturbance. The increase in QRS duration, the configuration in V1 and the degree of cardiomegaly were closely related. The greater the enlargement of the right heart chambers, the more important were the leftward and posteriorly directed portions of the QRS vectorcardiographic loop. The vectorcardiographic studies demonstrated that the cases of lesser cardiomegaly corresponded to those in which there was increased duration of the QRS complexes in the horizontal plane and predominance of the rightward portions.

Estudos sôbre reservatórios e vectores silvestres do Trypanosoma cruzi. XXIV. Variação dos dados biométricos obtidos em amostras do T. cruzi isolados de casos humanos da Doença de Chagas

Abstract: Estudo biometrico de 10 amostras de Trypanosoma cruzi isoladas de casos humanos da doenca de CHAGAS, nove mantidas em camundongos brancos jovens e uma mantida em ratos brancos jovens, mostrou a existencia de grandes variacoes amostrais. Assim os valores do comprimento total medio das diferentes amostras variaram entre 16,3μ e 21,8μ., enquanto os valores do indice nuclear medio oscilaram entre 0,93 e 1,52. Estes resultados ampliam os limites de variacoes amostrais ate agora observadas no T. cruzi, especialmente os que se referem ao indice nuclear medio.

Thyroidal Iodoproteins in Pendred's Syndrome

Abstract: The distribution of 127I, 125I, or 131I, and protein was studied in thyroid tissue from 3 patients with Pendred's syndrome. In each of these patients a significant amount of trapped iodide was dischargeable after administration of perchlorate. Two specimens (nodular and paranodular tissue) were studied from each patient. Iodinated insoluble protein comprised 6.4–33.1% of the total radioactive iodine in the homogenates. More participate labeled iodine was present in the nodular tissue, per g of tissue, as compared to paranodular tissue. Nearly ⅓–½ of the total 127I was incorporated into the particulate protein. The pattern of protein distribution followed closely that of stable iodine. In the nodular tissue it was found that the insoluble protein had more labeled iodine per μg of 127I than in the soluble fraction. After 3 weeks of a tracer dose the particulate protein had more labeled iodine per g than after 24 hr of labeling. The particulate iodoprotein was solubilized with trypsin and could be s...

Photoelastic Measurements of the Volume Expansion by the U-->F and U-->α Transformation in KBr

Abstract: Volume expansion by the introduction and transformation of point defects in alkali halide crystals was measured using the photoelastic technique. KBr crystals containing $U$ centers were used as convenient model cases, which allow the transformation of $U$ centers into $F$ or $\ensuremath{\alpha}$ centers and hydride interstitials by uv or x irradiation. All products of these reactions can be quantitatively controlled in their formation and annealing behavior. Their concentrations can be monitored by optical absorption measurements, and their microscopic structure models are well known. Volume-expansion measurements with an improved automatic photoelastimeter were performed parallel to the formation and annealing processes, and could thus be correlated to specific center transformations. From the dilatation, which is found to be strictly proportional to the $U\ensuremath{\rightarrow}F$ transformation at room temperature, the volume expansion per $F$ center can be determined. $U\ensuremath{\rightarrow}\ensuremath{\alpha}$ conversion by uv irradiation at low temperature produces volume expansion proportional to the $\ensuremath{\alpha}$-center concentration. Thermal annealing of the $\ensuremath{\alpha}$ centers occurs in correlation with the annealing of the volume expansion. This allows the accurate determination of the volume change per vacancy ${H}^{\ensuremath{-}}$-interstitial pair. Using Eshelby's theory and previous data on the lattice parameter of KBr: KH crystals, values for the microscopic dilatations around $F$ centers and $\ensuremath{\alpha}$ centers are obtained.

Mortalidade da pescada-foguete, Macrodon ancylodon

Abstract: The instantaneous mortality coefficient (F + M) of the commercial weakfish, Macrodon ancylodon (Bloch, 1801) caught by trawls along southern Brazilian coast (from latitude 28oS to 34oS), was computed by means of the annual catch variation (in number) by age per fishing effort from March 1961 to December 1964. The instantaneous mortality coefficient mean values for female and male was respectivelly 1.31 and 1.53. One year old recruits appear in the landings and the mesh selectivity operates on fish up to three years old. Three-year old class predominates in the landings.

Level scheme of123Sb

Abstract: Two new transitions in123Sb from the beta decay of the 3/2+ ground state of123Sn were found: one with (381.3±0.7) keV corresponding to (2.7±0.3)·10−2% of the disintegrations and one with (542.2±0.9) keV corresponding to (1.6±0.3)·10−2% of the disintegrations. The search for a 170 keV transition depopulating the 712 keV level gives an upper limit of 2·10−2% of the disintegrations. To describe properties of the level scheme of123Sb, calculations were made on the basis of a model which assumes the coupling of the unpaired proton with an eveneven core via a phenomenological core-to-particle interaction. The theoretical results concerning energies, spectroscopic factors and electromagnetic properties are compared with previously published and presently given experimental data with fairly good agreement.

the occurrence of dioctophymiasis in the Maned wolf Chrysocyon brachyurus

Abstract: Summary The authors describe in this paper the occurrence of five cases of dioctophymiasis in Maned wolves Chrysocyon brachyurus belonging to Sao Paulo Zoo. Clinical symptoms are described and the lesions found at post-mortem examination are noted. Agreeing with the veterinary literature on the subject, they also verify that the infestation is in the right kidney. Finally, they show the possibility of diagnosis by radiography and treatment by nephrectomy.

The effect of ribonuclease on rat-liver ribosomes

Abstract: 1. Rat-liver ribosomes lose about 50% of their amino acid-incorporating activity when preincubated with ribonuclease. 2. This preincubation results also in loss of about 50% of the original protein content and 75% of the RNA. 3. Ribosomes sedimented by ultracentrifugation, after preincubation with ribonuclease, show negligible contamination by crystalline enzyme. 4. Washing of ribosomes treated with ribonuclease releases further protein, restoring the original RNA/protein ratio. 5. The washed particle is again capable of promoting amino acid incorporation. 6. Examination of ribosomes treated with ribonuclease in the analytical ultracentrifuge reveals destruction of ribosomes, disappearance of dimers and a decrease in the sedimentation coefficient of monomers. 7. Washed ribosomes consist of even smaller particles with a sedimentation coefficient 60s.