Showing papers by "University of São Paulo published in 1979"
TL;DR: Examination of tissue sections from 15 species of vertebrates suggests that staining with Sirius Red, when combined with enhancement of birefringency, may be considered specific for collagen.
Abstract: Sirius Red, a strong anionic dye, stains collagen by reacting, via its sulphonic acid groups, with basic groups present in the collagen molecule. The elongated dye molecules are attached to the collagen fibre in such a way that their long axes are parallel. This parallel relationship between dye and collagen results in an enhanced birefringency. Examination of tissue sections from 15 species of vertebrates suggests that staining with Sirius Red, when combined with enhancement of birefringency, may be considered specific for collagen. An improved and modified method of staining with Sirius Red is presented.
2,367 citations
TL;DR: The results support the conclusion that digestion takes place in three spatially organized steps, and the existence of two extracellular sites for digestion in R. americana is considered to be an adaptation to conserve secreted enzymes.
210 citations
TL;DR: A method to quantitate collagen in solution based on binding of the dye Sirius Supra red F3BA by collagen followed by elution and estimation of the bound dye in a spectrophotometer is described.
198 citations
TL;DR: The FDA-EB test can be successfuly employed to assay yeast and yeast like cells viability since a good correlation was observed between this assay and the colony count technique.
Abstract: The fluorescein diacetate-ethidium bromide (FDA-EB) fluorescence method, primarily used to determine viability of mammalian cells, was applied to several fungi species. Living fungi cells produced fluorochromasia, i.e., an intracellular accumulation of fluorescein which could be easily visualized as a green color under the U.V. microscope. Dead cells showed a red bright color due to ethidium bromide penetration. The FDA-EB test can be successfuly employed to assay yeast and yeast like cells viability since a good correlation was observed between this assay and the colony count technique. The main advantages of FDA-EB test are its speed, high sensitivity and simplicity.
181 citations
TL;DR: A review of studies dealing with the identification of clusters and complexes, or of groups of industries linked by flows of goods and services, or showing significant mutual locational attraction is presented in this paper.
Abstract: The paper reviews systematically studies dealing with the identification of clusters and complexes, or of groups of industries linked by flows of goods and services, or showing significant mutual locational attraction. The studies are classified according to the method used for identification, and to their spatial focus. Some 60 types of industrial groupings have been found to exist by the various students of spatial aggregation of industries but many showed only small differences in their sectoral composition. The similarity of results despite the diversity of methods used, degree of sectoral disaggregation, and areas examined was striking. A set of tables comparing the findings is presented along with a detailed analysis of methods and results.
159 citations
TL;DR: The factorizable S -matrix with Z (N ) symmetry was constructed in this paper, and it is speculated that the field theory belonging to this S-matrix matrix is related to the scaling limit of Z ( N ) generalizations of the Ising model.
123 citations
TL;DR: Alkaline hydrolysis of peptides is carried out prior to detection to increase the sensitivity of the method and is convenient for the manual determination of 5 to 100 nmol of amino acids in the 50–100 samples required to define a chromatographic elution profile.
93 citations
TL;DR: The results favor the hypothesis that H2O2 reacts in the cell producing a radical species which brings about the formation of DNA single‐strand breaks, and these breaks are effectively repaired by both XP12RO and VA13 fibroblasts.
Abstract: — Human fibroblasts in culture lose the capacity of proliferating when exposed to hydrogen peroxide in the concentration range of 1 to 10 μM. The toxicity of H2O2 to xeroderma pigmentosum cells (XP12RO). defective in excision repair of lesions produced by UV-irradiation, was about twice as high as to cells proficient in excision repair (VA13). This compound produces single-strand breaks in intracellular DNA but not in purified DNA. These breaks are in situ physical discontinuities rather than alkali-labile bonds, and their generation occurs at the same extent at 4°C and 37° indicating that they are not produced by an endonuclease. The results favor the hypothesis that H2O2 reacts in the cell producing a radical species which brings about the formation of DNA single-strand breaks. These breaks are effectively repaired by both XP12RO and VA13 fibroblasts. The possible reason for the lethality of H2O2 is discussed.
92 citations
TL;DR: Neither complement activation nor a fungus-secreted factor seems to explain the initial events of the lesion formation induced by P. brasiliensis, so it is indicated that the alternative pathway of complement activation is involved in the expression of this phenomenon.
80 citations
01 Mar 1979
TL;DR: In this article, the Chapada Diamantina Group is proposed as follows: 1- At 1,7 b.y. formed the first sedimentary basins associated with continental acid voleanism.
Abstract: This paper presents and discursses some of the last geochronological determinations carried out on rocks of the Espinhaco Mountain Belt; by different radiometric methods. For the most part, the basement is composed of Archaean rocks, with formation of magmatites and granites during the Transamazonian cycle (2,0 b.y.). The geologic evolution of the Chapada Diamantina Group is proposed as follows: 1- At 1,7 b.y. formed the first sedimentary basins, associated with continental acid voleanism. 2 - The main stage of folding and epizonal metamorphism occured at approximately 1,2 b.y, with post-tectonic events until 1,0 b.y. These last ones include basicfissure volcanism and tectonic uplift. 3 - During the Brazilian cycle (650-400 m.a.) the tectonothermal phenomena have affected in several ways and with different intensity the age determinations of all geological units.
78 citations
TL;DR: The induced DNA lesions were shown to be equally repairable in both excision proficient and defective (xeroderma pigmentosum) human cell lines, and the active photoproduct formed was shows to be hydrogen peroxide.
Abstract: — When mammalian cells were exposed to visible-fluorescent light or near-UV light in the medium containing riboflavin and L-tryptophan, single-strand breaks appeared in their DNA. This did not occur if either riboflavin or tryptophan was omitted from the medium. The same effect was observed when cells were added to the pre-irradiated medium, indicating that a stable photoproduct was responsible. The induced DNA lesions were shown to be equally repairable in both excision proficient and defective (xeroderma pigmentosum) human cell lines. The active photoproduct formed was shown to be hydrogen peroxide. The possible relationship between these results and the near-UV induced killing of mammalian cells is discussed.
TL;DR: Observations using the Picrosirius-polarization method strongly suggest that two different types of collagen fibers are present in the connective tissues of nerves and ganglia, distinguishable on the basis of diameter.
Abstract: Nerves and ganglia from a variety of fish, amphibian, reptilian and mammalian species were studied by optical and electron microscopy. Observations using the Picrosirius-polarization method strongly suggest that two different types of collagen fibers are present in the connective tissues of nerves and ganglia. Electron microscopy of nerves and ganglia showed the presence of two different collagen fibril populations, distinguishable on the basis of diameter, located in different compartments of these structures. Thicker fibrils are present in nerve and ganglionic epineurium. Thinner fibrils are present in the endoneurium, surrounding nerve fibers and ganglionic cells, and between the concentric layers of perineurial cells. These results were consistently observed in all species studied and very probably represent a general phenomenon in vertebrates.
TL;DR: Em colonias de Triatoma sordida, Panstrongylus megistus e Rhodnius neglectus, espontaneamente desenvolvidas em galinheiros experimentais, observou-se as condicoes de desenVolvimento, bem como a variacao e a permanencia de seus componentes.
Abstract: Em colonias de Triatoma sordida, Panstrongylus megistus e Rhodnius neglectus, espontaneamente desenvolvidas em galinheiros experimentais, observou-se as condicoes de desenvolvimento, bem como a variacao e a permanencia de seus componentes. A colonizacao e dispersao de T. sordida e favorecida em ambiente aberto resultante da instalacao de pastagens com consequente proliferacao de arvores isoladas e secas. O desenvolvimento de colonias de P. megistus ocorre em ambiente coberto na intima proximidade de matas residuais, admitindo-se que os anexos domiciliares lhes sirvam de pontos de atracao. O R. neglectus revelou certo grau de domiciliacao aliado a capacidade de dispersao que lhe permite atravessar distâncias apreciaveis. O primeiro semestre do ano parece incluir a epoca infestante das colonias de T. sordida revelada pela maior producao de adultos e ninfas de primeiro estadio. O papel de visitantes observado para algumas ninfas dessa especie, permite supor do poder de dispersao dessas formas.
TL;DR: Various properties of freeze-dried fractions of bovine blood have been compared and chemical scores indicated that methionine was the most limiting amino acid for globulin and albumin and Isoleucine was limiting for globin.
Abstract: Various properties of freeze-dried fractions of bovine blood have been compared. Dried whole plasma, albumin, globulin and globin showed high solubility from pH 3 to 8, but this fell sharply with plasma on storage at 40°C and Aw 0.32 or higher. Albumin showed the best foaming properties followed by plasma, globulin and globin. These proteins in 1 % solution were able to emulsify 60, 115, 70 and 45% of their volume of oil, respectively. Net protein ratios were 3.57 for globulin, 1.96 for albumin and negative for globin. Chemical scores indicated that methionine was the most limiting amino acid for globulin and albumin. Isoleucine was limiting for globin.
TL;DR: In this article, the gas phase affinities of HF (95.5±1.4 kcal/mol), HCl (135±1 kcal/m), and HBr (141±1 kg/m) were measured along with the HX+HX binding energies for the HCl and H Br systems.
Abstract: Gas‐phase proton affinities of HF (95.5±1.4 kcal/mol), HCl (135±1 kcal/mol), and HBr (141±1 kcal/mol) have been measured along with the HX+–HX binding energies for the HCl and HBr systems (20±2 and 23±2 kcal/mol, respectively) by photoionization of van der Waals molecules produced in a supersonic expansion. A detailed discussion of the potentialities and limitations of the method is presented.
TL;DR: An electron microscopic study of the exocrine and myoepithelial cells of the parotid gland of the rat between days 2 and 40 of the postpartum was undertaken, confirming morphological data of the literature on the evolution of the acinar cells.
Abstract: An electron microscopic study of the exocrine and myoepithelial cells of the parotid gland of the rat between days 2 and 40 of the postpartum was undertaken. Besides confirming morphological data of the literature on the evolution of the acinar cells, the following observations are reported.1. At early postnatal development in some acini “mucous-like” cells containing secretory granules with light and dense parts may be observed. Cells with these types of granules were not found after day 20.2. Morphological differentiation and maturation of the myoepithelial cells were followed. A parallelism was observed between the maturation of these myoepithelial cells and of the acinar cells. Myofilaments first appear around the nucleus at day 5 and between days 20 and 30 a considerable amount of these filaments is found in the already typical myoepithelial cells.3. Active morphogenesis seems to be occurring in all cellular compartments namely at very early postnatal periods, e.g., between days 2 to 15.4. The distribution and amount of thin and intermediate sized microfilaments in cells of these compartments varied visibly by various orders of magnitude.
TL;DR: Results were considered to be a consequence of supersensitivity of central dopaminergic receptors, and differences were almost unobservable in animals gradually withdrawn, suggesting that the phenomenon is reversible.
Abstract: The effects of abrupt and gradual withdrawal from long-term haloperidol treatment on rat open field behavior was studied Abrupt withdrawal induced a significant increase in all parameters of activity observed except defecation, this increase being higher 72 h after the last haloperidol injection Results were considered to be a consequence of supersensitivity of central dopaminergic receptors These differences were almost unobservable in animals gradually withdrawn, thus suggesting that the phenomenon is reversible
TL;DR: In this article, the scattering theory of the chiral Gross-Neveu model is established in terms of a massive field with generalized statistics, and the property of antiparticles being bound states of particles is consistently formulated.
Abstract: We show how to establish the scattering theory of the chiral Gross-Neveu model in terms of a massive field with generalized statistics. It is in terms of this field that the property of antiparticles being bound states of particles is consistently formulated. We also employ an auxiliary local Fermi field in order to develop an infrared-regular $\frac{1}{N}$ expansion. The connection between these two fields is discussed.
TL;DR: Acetate, phtalate or citrate, at pH 4.0, but not at higher pH values, were able to induce plasma membrane vesiculation, and antibodies prepared against purified vesicles are able to agglutinate epimastigote forms of T. cruzi.
TL;DR: Changes in composition could lead to alterations in the proportion and size of the aggregates they form in the cartilages, furnishing the conditions for the processes of growth and calcification to occur.
Abstract: The structure of chondroitin sulfates and proteoglycans extracted from human normal young and adult cartilages and also from human arthrosic cartilages are reported. The adult articular cartilage contains almost exclusively chondroitin 6-sulfate, whereas the normal young and the arthrosic cartilage chondroitin sulfates are hybrid polymers, containing 4-sulfated and 6-sulfated disaccharide units, distributed in a quite random way along the molecules. The young cartilage proteoglycans also differ from the adult cartilage proteoglycans by their contents of keratan sulfate, the relative proportion of nonaggregating proteoglycans and electrophoretic migration in agarose gel slabs. The proteoglycans from arthrosic cartilages are very similar to those from young normal cartilages. Such changes in composition could lead to alterations in the proportion and size of the aggregates they form in the cartilages, furnishing the conditions for the processes of growth and calcification to occur.
TL;DR: Fractionation experiments indicate that both S7 and S14 oocytes are capable of repairing, in different periods of time, a similar amount of dominant lethal damage.
Abstract: Dominant lethal mutations induced by γ-radiation were measured in stage-7 and stage-14 oocytes of Musca domestica. At both stages the data are consistent with the multi-hit theory on radiation induction of dominant lethals. This conclusion is supported by fractionation experiments which indicate that both] S7 and S14 oocytes are capable of repairing, in defferent periods of time, a similar amount of dominant lethal damage.
TL;DR: Incubation of 25 and 30 day old nodulated plants ofPhaseolus vulgaris for periods of 24 h and 72 h under 15-dinitrogen atmosphere indicated nitrogen enrichment of soil compared with soil free of plants and with other plants under the same experimental conditions.
Abstract: Incubation of 25 and 30 day old nodulated plants ofPhaseolus vulgaris for periods of 24 h and 72 h under 15-dinitrogen atmosphere indicated nitrogen enrichment of soil compared with soil free of plants and with other plants under the same experimental conditions. This indication of release from the root-nodule system is discussed.
TL;DR: Determination of succinate cytochrome c reductase and glucose-6-phosphatase activities, as well as of total amounts of DNA and RNA in the purified fraction, indicates a negligible contamination from other cellular organelles.
TL;DR: Drugs from Myristicaceae species used in the Amazon region as hallucinogens and arrow poisons, as well as for the healing of infected wounds, are reviewed and a proposal that the red colour of the bark resins may be due to oxidative dimers of flavans is proposed.
TL;DR: In this article, a regular, deterministic, rough surface was tested at four velocities from 11 to 40 m/s, with and without blowing, to evaluate the Stanton number and friction factor characteristics.
Abstract: A regular, deterministic, rough surface was tested at four velocities from 11 to 40 m/s, with and without blowing, to evaluate the Stanton number and friction factor characteristics. Hot-wire data were taken to document the turbulence components, the Reynolds stresses, and the turbulent heat flux. Data are presented concerning the streamwise development of the mean and fluctuating components, and the effect of blowing. Correlation coefficients and mixing lengths were deduced from the hot-wire data and are also presented. While the mean velocity data showed only two allowable states for the boundary layer (laminar and “fully rough”), the turbulence structure indicated a third: “transitionally rough”. Distributions of u′ v′ /uτ 2 and v′ t′ /uτ tτ are similar, except for high blowing (F = 0.004). The turbulent Prandtl number lies between 0.85 and 1.0 for the entire layer, and a mixing length constant of κ = 0.41 describes the data with good accuracy for all velocities and all values of blowing tested.
TL;DR: Calmodulin appears to be ubiquitous in the animal kingdom, although it lacks tissue and species specificity, suggesting that it may be a very primitive protein.
TL;DR: In this paper, the authors carried out an isotopic investigation of the Precambrian granulite terrain of eastern Bahia, Brazil, and obtained Rb-Sr and K-Ar isochron ages of 3160±60 Ma, 2730±50 Ma, 2300−2450 Ma and 1800−2000 Ma, respectively.
TL;DR: A general computational procedure for the estimation of the distribution of conduction velocities in peripheral nerves is proposed from the compound electrical nerve response and the single fiber response measured either under excised nerve conditions, in locus with needle electrodes or non-invasively with surface electrodes.
TL;DR: The inability to synthesize cyclic AMP drastically affects the nutritional metabolism of Neurospora crassa and evidence suggested that nutritional deficiencies were a direct result of the cr-1 mutation.
Abstract: The inability to synthesize cyclic AMP drastically affects the nutritional metabolism of Neurospora crassa. The adenylyl cyclase-less mutant cr-1 (crisp) did not utilize several carbon sources, including glycerol, mannitol, arabinose, and casaminoacids. However, in glucose or acetate it grew as well as the wild type. The following evidence suggested that these nutritional deficiencies were a direct result of the cr-1 mutation: (i), in crosses to wild type they segregated together with the crisp morphological marker; (ii), cyclic AMP added to the cr-1 mutant growth medium overcame the nutritional deficiencies; (iii), the cyclic AMP effect was specific for the crisp mutant, for it was not observed with the wild type, nor with a spontaneous glycerolutilizing cr-1 strain.
TL;DR: Os dados sobre os ciclos anuais de colonias de Triatoma sordida desenvolvidas espontaneamente em galinheiros experimentais confirmaram os relatados em trabalho anterior relativos ao relacionamento com o tempo e a sobrevivencia.
Abstract: Sao apresentados novos dados sobre os ciclos anuais de colonias de Triatoma sordida desenvolvidas espontaneamente em galinheiros experimentais Os resultados das observacoes confirmaram os relatados em trabalho anterior relativos ao relacionamento com o tempo e a sobrevivencia Quanto a duracao dos estadios ninfais obteve-se valor superior, provavelmente devido ao maior numero de observacoes realizadas neste trabalho em comparacao com as precedentes Computando-se os resultados destas observacoes com os das anteriormente feitas, tanto para T sordida como para Panstrongylus megistus, foi possivel identificar com maior seguranca as epocas de dispersao ativa, no periodo anual por parte das formas adultas Para o primeiro desses triaiomineos, o fenomeno atinge maior intensidade a partir de marco podendo prolongar-se ate maio Para a outra especie, a dispersao ocorre principalmente a partir de outubro prolongando-se ate novembro Tais aspectos permitem determinar as ocasioes mais propicias para a aplicacao das medidas de vigilância, como sendo aquelas em que a composicao das populacoes triatominicas e predominantemente constituida de primeiras ninfas e adultos Assim sendo, tais epocas correspondem aos meses de julho e agosto para o T sordida e de novembro e dezembro para o P megistus, pelo menos nesta regiao sudeste do Brasil