Showing papers by "University of São Paulo published in 1971"

Binding of Sheep Red Blood Cells to a Large Population of Human Lymphocytes

Abstract: WHILE investigating the interaction between antigen–antibody–complement complexes and lymphoid cells1, we have noticed that sheep red blood cells (SRBC) adhered to a surprisingly large proportion of human peripheral blood lymphocytes forming clusters (“rosettes”). We have now examined the conditions in which this interaction occurs, and the frequency of rosette forming lymphocytes in the peripheral blood of normal individuals and a few patients with haematological diseases.

Cucumber Beetle Resistance and Mite Susceptibility Controlled by the Bitter Gene in Cucumis sativus L.

Abstract: Antibiotic and nonpreference mechanisms are related in cucumber through the action of the bi gene and the absence of cucurbitacins. Cucurbitacins attract cucumber beetles and cause feeding whereas they have an antibiotic effect on two-spotted mites.

Arterial supply of the femoral head. A combined angiographic and histological study.

Abstract: The findings in a correlated angiographic and histological study of eighty-one selected femoral heads obtained from cadavera ranging from thirteen to eighty years of age are reported. Three groups of arteries were demonstrated: upper and lower capital and ligamental arteries. Anastomoses of the upper and lower capital arteries formed the superoinferior arch in fifty-five of the eighty-one specimens; ligamental arteries were visualized in twenty-eight specimens; superoligamental arches, in twelve, and superoinferoligamental arches, in fourteen. There was no correlation between the occurrence of the arches and age or race, but there was a significant correlation between the presence of the superoinferior arch and the female sex, the arch being found in twenty-eight of thirty-three female cadavera and in only two of forty-eight male cadavera. The histological studies of the site of attachment of the ligamentum teres revealed arteries in every specimen. However, in approximately two-thirds of them, these arteries were 200 micrometers in diameter or less and did not fill with radiopaque material; in the other third the vessels ranged from 201 to 511 micrometers in diameter and did fill with the injection medium. These larger vessels anastomose with the arterial network within the femoral head and contribute to its blood supply.

Diversificação fisiológica e morfológica de Micropogon furnieri (Desmarest, 1822) ao sul de Cabo Frio, Brasil

Abstract: This paper deals with some aspects of faunistic diversification and refers to part of the distribution area of a sciaenid fish Micropogon furnieri (Desmarest, 1822) Jordan & Evermann 1884, widely distributed. Such species is characteristic of the tropical area and occurs along the Brazilian coast with highest abundance south of Cabo Frio. The analysis of variations of six meristic characters and eight body proportions and of some reproduction and growth features has shown that along the coast between latitudes 23oS and 33oS diversifi cation occurs within the species; such diversification implies in the existence of two populations, one occupying the area between 23oS and 29oS (area I) and the other between 29oS and 33oS (area II). The eco logical differences between the two mentioned areas according to our point of view is the reason for the species diversification in the whole area under observation. The differences recorded as the characteristics studied were suf ficient enough to illustrate the existence of two populations reproductively isolated suggesting that some gene exchange, if any, between both populations occurs in a very low rate. Our results show that abundance estimates of M. furnieri in this area must be made for each population as a whole until further studies on genetic characters are developed which may confirm the existence of gene exchange and if so, the gene flow rate. As the present study does not cover the total area of occurrence of Micropogon furnieri no hypothesis is extended to the general pattern of diversification (eventual presence of sub-species) and no systematic "status" and names are given to the populations identified.

Aspectos ecológicos da tripanossomose americana: III - dispersão local de triatomíneos, com especial referência ao Triatoma sordida

Abstract: Sao apresentados os resultados obtidos nas investigacoes levadas a efeito no Bairro Joao Pedro, municipio de Guira e na Fazenda Vila Maria, municipio de Sertaozinho, Estado de Sao Paulo, Brasil Os resultados das provas de precipitina indicam varias fontes alimentares para Triatoma sordida e, mais restritas, para Rhodnius neglectus, se bem que revelem mais a influencia das oportunidades do que de preferencias propriamente ditas O exame minucioso dos ecotopos artificiais, representados por casas e anexos, mostram nitida invasao por parte do T sordida O transporte passivo deste triatomineo foi sugerido pelo encontro de ninfas e adultos em montes de lenha, obtidos a custa de arvores secas Evidenciou-se tambem o transporte de ninfas de primeiros estadios do mesmo hemiptero, entre as penas de pardais (Passer domesticus) em cujos ninhos, situados no forro das casas, ocorre a colonizacao do inseto A atracao do ambiente domiciliar sobre o hemiptero deve-se principalmente aos anexos que se destinam aos animais domesticos, onde o triatomineo se coloniza facilmente Tais ambientes agem, pois, como locais de concentracao, a partir de focos naturais a certa distância A semelhanca do que se verificou para outras especies, admite-se, pelas evidencias, a movimentacao ativa desses insetos, a procura de ecotopos mais estaveis Em consequencia, e de se esperar incremento da invasao domiciliar pelo T sordida

Concurrent performances: effect of punishment contingent on the switching response.

Abstract: Pigeons' key-pecking responses were maintained under concurrently available variable-interval schedules of reinforcement. Responses in the presence of two different key-colors were reinforced on two independent and concurrent variable-interval schedules of food reinforcement, each associated with one of the key colors (red or green). Pecks at a second key (changeover key), always white, would alternate the colors on the main key. In Exp. 1 and 2, electric shock of 50 msec duration followed immediately after changeovers. The proportion of responses in the presence of the color associated with the higher frequency of reinforcements per hour was a direct function of shock intensity contingent on changeovers. When both schedules provided equal number of reinforcements per hour, there was no systematic effect of shock intensity on response distribution. In Exp. 3, a timeout period was contingent on changeovers, and response distribution was a function of timeout length.

Ecological aspects of South American tripanosomiasis: II - local distribution and dispersion of triatomids in natural and artificial ecotopes

Abstract: Sao apresentados os resultados de investigacao destinada a estabelecer o quadro de distribuicao de Triatoma sordida e Rhodnius neglectus em areas com ecotopos naturais e artificiais. Essa distribuicao revelou-se do tipo agrupado ou contagiante, dirigida uniformemente para casas e anexos por parte do primeiro, e para palmeiras por parte do segundo. Em areas de vegetacao mais densa, do tipo cerrado, a densidade e praticamente nula ou muito baixa, admitindo-se que isso deva correr por conta da competicao. As modificacoes introduzidas pelo homem tendem a anular esse fator, alem de, as suas habitacoes, se transformarem em ecotopos que atraem a populacao de T. sordida. Esse fato, aliado a eliminacao local do T. infestans, parece explicar a tendencia invasiva daquele triatomineo. Evidenciou-se tambem a persistencia da infeccao pelo Trypanosoma cruzi em triatomineos e vertebrados domiciliados, o que representa potencial para o incremento da transmissao.

Mud shrimps of the genus Callianassa leach from the Brazilian coast (Crustacea, Decapoda)

Abstract: Callianassa branneri Rathbun was the only species of the genus recorded from the Atlantic coast of South America. In the present work five other species are recorded. Callianassa guassutinga, C. guara and C. mirim are considered as new to science. Callianassa major Say, 1818 and C. jamaicensis Schmitt, 1935, were previously known from the Atlantic coast of North America. The variety louisianensis of Callianassa jamaicensis is considered without systematic value as the present material fills most gaps between the variety and the typical form. All the species here described (or redescribed) fit perfectly in the subgenus Callichirus, besides having the same branchial formula and number of pleopods, characteristics also considered as significant to their taxonomy.

Cretaceous-Early Tertiary Metamorphic K-Ar Age Values from the South Caribbean

Abstract: Fourteen K-Ar age values from the Santa Marta schists (Colombia), of greenschist and amphibolite metamorphic facies, indicate two metamorphic episodes: mid-Cretaceous (or older) and Paleocene. Argon retentivity of hornblende appears to be little affected by a large Eocene diorite batholith, except near the contact. Whole-rock phyllitesamples from the same terrain give mid-Tertiary age values, suggesting considerable argon loss.

Hydroxyurea-induced inhibition of DNA puff development in the salivary gland chromosomes of Bradysia hygida

Abstract: The injection of hydroxyurea at a critical time during the fourth larval instar inhibits the development of all DNA puffs in the salivary gland chromosomes of Bradysia hygida. RNA puff formation is not disturbed and larval development continues. The effect is explained as a result of a selective and general inhibitory action of the drug on DNA synthesis during the time when gene amplification occurs in the salivary glands. The incorporation of uridine into the chromosome regions where DNA puff development has been inhibited is sharply decreased in comparison with the incorporation into non-amplifying parts of the same chromosomes. The interpretation proposed for the cytologic observations seems to offer a better understanding of the nature of the DNA puffs.

Effects of the Coulomb Correlation on the Calculated Results for Atoms with and without Spin Polarization

Abstract: In this paper we present the results of some atomic calculations as affected by the Coulomb correlation. We deal with atoms and ions with and without spin polarization. Thus we are able to compare calculated energy eigenvalues and hyperfine fields of contact with the experimental ionization energies and fields. Our approximation for the mass operator (exchange plus correlation) can thus be compared with the approximations proposed by Slater, Gaspar, Kohn and Sham, and Liberman. A broad evaluation of the results implies that our approximation for exchange and correlation is correct. Furthermore, when neglecting the correlation effects, we noticed that the results become poorer. Thus, this paper favors a single-particle description of many-body systems based on an effective-wave equation with the mass operator instead of the simpler exchange operator of the Hartree-Fock theory.

Notes on the Bull shark Carcharhinus leucas in the lagoon region of Cananéia, Brazil

Abstract: Ninety one young specimens and 3 adult females of BulI shark ("cacao cabeca chata") caught in the lagoon region of Cananeia were examined, their tooth formula being 27/25 and the number of pre-caudal vertebrae ranging from 109 to 115. The proportion between the 1st and 2nd dorsal fins were found to be 2.3 and 2.8 for the young,and 2.9 to 3.1 for the adults. These data confirm that the studied form belongs to C. leuoas. Young occur regularly but in limited numbers.As regards the adults, however, females only appear during the short parturition period, i.e., from November to February. The number of embryos in the litters were from 7 to 9, their sizes ranging between 768-812 mm. The length of the smallest free young found was 697 mm, but young presumably 9 to 12 months old had 98 to 112 cm; between 21 and 24 months they were reaching 124 to 128 cm, that is, the same size they have when they start migrating to the open sea. The feeding inhibition phenomenon during the period of parturition was not observed in the female specimens caught in the lagoon. The more abundant species found in the stomach contents were: Arius spixii; Chloroscombrus chrysurus; A. grandicassus; A. barbus; Felichtys marinus; Genidens genidens; Chanophorus tajacica and Carcharhinus porosus.

Indication of gene amplification in rhynchosciara by rna-dna hybridization

Abstract: nism of cell differentiation was recently demonstrated in the case of ribosomal RNA cistrons of amphibian oocytes (1-3), and it seems that this phenomenon is of widespread occurrence (4) . In somatic cells the evidence for amplification thus far is based on cytological observations . The best known cases are those of Rhynchosciara and Sciara ; in the prepupal phase of these insects, it was possible to show \"extra\" DNA synthesis in certain bands of the polytene chromosomes of the salivary gland cells (5-7) . We now have been able to study gene amplification in Rhynchosciara salivary gland cells with the aid of hybridization experiments . For this purpose we used an RNA fraction which we have recently succeeded in obtaining from these cells . This fraction has a high turnover and is mainly of nuclear origin, and thus it was designated as nRNA ; its preparation and characteristics are described in a separate paper (8) . In Fig . 1 we present data obtained by hybridizing nRNA 3H from glands at the time of giant puff formation with three different DNA preparations . One of these preparations was obtained from glands of larvae at the same age as the larvae from which the nRNA was obtained, larvae about 52 days old (\"puff-DNA\") ; the other from glands of larvae at an earlier age when no puffs are present, larvae about 40 days old (\"before puff-DNA\") ; and the third was obtained from ovaries of adult virgin flies (\"ovary-DNA\") . The results show that ovary-DNA and before puff-DNA hybridize equally well with this nRNA ; in contrast, puffDNA hybridizes about twice as much . These same results were obtained in two other separated experiments, and thus we think that they strongly BRIEF NOTES

Lymphocyte cultures and skin allograft survival in patients with South American blastomycosis

Abstract: Lymphocyte cultures with phytohemagglutinin (PHA), skin allograft survival, intradermal tests with microbial antigens, and sensitization to dinitrochlorobenzene (DNCB) were performed in 10 patients with South American blastomycosis. The lymphocyte stimulation in vitro was depressed in 6 of the patients. Exposure to DNCB resulted in sensitization in 3 of 10 patients. Among the 7 DNCB-negative patients, Mast transformation was depressed in 6, and in 2 of these there was prolonged skin allograft survival. The results suggest a severe impairment of delayed hypersensitivity in some patients with South American blastomycosis.

Inhibition of the permeability response to vasopressin and oxytocin in the toad bladder: Effects of bradykinin, kallidin, eledoisin, and physalaemin.

Abstract: It has been shown by means of Bentley'sin vitro preparation of the isolated urinary bladder of the toad,Bufo marinus paracnemis Lutz, that bradykinin reversibly inhibited the increase brought about by vasopressin on the permeability to water of the toad bladder. The increased hydro-osmotic response of the bladder to oxytocin was also inhibited by the kinin. The effect on water permeability was observed when bradykinin was added either to the serosal Ringer's solution or to the mucosal solution. The addition of bradykinin alone did not alter the basal osmotic water transfer across the bladder. In this context, bradykinin acted as a competitive antagonist of vasopressin (and oxytocin). Although lacking intrinsic activity, bradykinin exhibited affinity for receptor sites that are also common to the neurohypophysial hormones, causing a parallel shift of the log-dose/response curve for vasopressin without changing the maximal responses. The effects of other kinins (namely kallidin, eledoisin and physalaemin) on the toad bladder were also tested. Each of these drugs alone did not change the basal water flux across the bladder wall. Like bradykinin, these peptides inhibited the increase in water permeability evoked by vasopressin and oxytocin in the bladder. In view of the importance of neurohypophysial hormones and their target tissues to the osmotic homeostasis of amphibians, and the observation of antagonism between the kinins and the pituitary hormones coupled to the abundance of kinins in the amphibian organism, particularly in the skin and urinary bladder, teleological reasoning predicts a physiological role for the kinins, possibly functioning to dampen excesses and oscillations in membrane permeability that could occur in face of a constant and variable secretion of neurohypophysial hormone, thus adding to the homeostatic response of the amphibian organism.

Equinodermes do Brasil: I. sôbre algumas espécies novas e outras pouco conhecidas, para o Brasil

Abstract: Some echinoderms from the South Brazilian region are described. Seven are new to the science: Cucumaria manoelina sp.n., Thyone montoucheti sp.n., Psolus marcusi sp.n., Psolus vitoriae sp.n., Ophioderma divae sp.n., Amphioplus lucyae sp.n. and Chaetaster vanzolinicus sp.n. Some observations are presented on the distribution of Antedondubeni Bohlsche, 1886, Cucumaria pulcherrima (Ayres, 1854), Thyone belli Ludwig, 1887 and of Ophiothrix rathbuni Ludwig, 1882 in Brazilian marine shelf region.

Motion of a Space Station. I

Abstract: In this first part of the work we develop the equations of motion of a triaxial space station in orbit around the oblate Earth. A first order solution of the problem is presented and the method of complete integration of the system is outlined up to second order of approximation. The zero order part of the Hamiltonian includes both the kinetic and potential energy (Earth's Newtonian attraction) of the station, while the motion in the vicinity of a specific configuration is assumed.

A study of the life history of Brazilian sardines, Sardinella aurita: I. distribution and abundance of sardine eggs in the region of Ilha Grande, Rio de Janeiro

Abstract: Distribution and abundance of sardine eggs in the Ilha Grande region, Rio de Janeiro, Brazil, were studied during five cruises for the 1969 1970 period. Using the shipboard fertilized eggs and the planktonic eggs, morphological descriptions of Brazilian sardine eggs are given. Spawning occurs during the summer from September to March in the coastal water off Ilha Grande to Ilha de Sao Sebastiao down to a depth of 100 meters. Spawning may take place a few hours prior to midnight. lt was noticed that spawning has a close relationship to an area of cold water up welling. Spawning groups are isolated and spawning is small in scale in this region. Temperature and salinity in the spawning area range between 18-24oC and 35.1-35.9‰ respectively.

Motility of the sigmoid colon and rectum: contribution to the physiopathology of megacolon in Chagas' disease.

Abstract: The motility of the sigmoid colon and rectum was studied by electromanometry in normal subjects and in patients with chagasic megacolon before and 2.5 to 3.5 years after treatment by abdomino-endoanal rectosigmoidectomy. The study was with the subjects at rest and after injection of methacholine chloride. Records of normal subjects showed minimal activity with a preponderance of simple waves of low amplitude and short duration, the sigmoid and rectum exhibiting independent activities during the major period of observation. Patients with chagasic megacolon, both before and after surgical treatment, had hyperactivity, with more numerous waves of higher amplitude and longer duration. They also had greater proportions of complex waves, and activities of the two segments of colon studied were synchronous. In normal subjects, methacholine chloride did not alter the motor activity of the sigmoid and rectum. In patients with chagasic megacolon, both before and after operation, methacholine chloride increased motor activity in both segments. All abnormalities in colonic motor activity of patients with chagasic megacolon were considered to result from the lesions of the ganglion cells of the intestinal myenteric plexus always present in this disease.