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Showing papers by "Federal University of Rio de Janeiro published in 1968"


Journal ArticleDOI
TL;DR: Trypanosoma cruzi in tissue cultures was studied with the electron microscope after double fixation in glutaraldehyde and osmium tetroxide, and embedding in Epon, and some new structures were found in the flagellum and kinetoplast-chondriome.
Abstract: SYNOPSIS. Trypanosoma cruzi in tissue cultures was studied with the electron microscope after double fixation in glutaraldehyde and osmium tetroxide, and embedding in Epon. Previous findings on its fine structure were confirmed, and some new structures were found in the flagellum and kinetoplast-chondriome. In the flagellum, an intraflagellar body was found, similar to that observed in other trypanosomes, beginning at the base of the flagellum and running along the axial fibre bundle thruout its length. The axial fibre bundle is formed by interconnecting tubules, the outer ones apparently smooth, the inner ones with a helical substructure. Lateral extensions from the outer tubules in the flagellar bundle seem to enter the intraflagellar body. The kinetopiast in the leishmania bodies has the same electrondense structure described before. In the trypanosome form it has assumed a large spherical shape, in which the formerly short, compressed fibres have grown in length, are more dispersed and have an irregular shape. They are oriented in the direction of the body's length in parallel array. The whole formation is continuous with a long mitochondrion which begins in the region of the nucleus and extends up almost to the tip of the trypanosome. The matrix of the kinetoplast in these forms is electron-transparent; the matrix of the mitochondria is rather dense. In a few extracellular trypanosomes, a special structure was found in which the kinetoplast is composed of electron-transparent formations, arranged in orderly horizontal lines quite similar to the mitochondrial cristae of the parasite. The significance of this structure is uncertain.

33 citations


Journal ArticleDOI
27 Apr 1968-Nature
TL;DR: Curare, a drug which blocks nerve impulses at the myoneural junction, has been used in investigations aimed at the identification of the receptor substance of acetylcholine.
Abstract: Curare, a drug which blocks nerve impulses at the myoneural junction, has been used in investigations aimed at the identification of the receptor substance of acetylcholine. This article reviews the progress so far.

14 citations


Journal ArticleDOI
TL;DR: The activation of Ca++ uptake induced by spermine is dependent on ATP, oxalate, and KCl concentration in the reaction medium, and at low ATP concentrations, the Ca++ retained by microsomes is released to the reactionmedium.

12 citations


Journal ArticleDOI
TL;DR: It is suggested that the mechanism responsible for the complete tonic seizure is fully functional from birth, while that responsible for clonic seizure only reaches full maturity at 3 weeks of age.
Abstract: 1. The maturation of the convulsogenic activity of the caudal brainstem and spinal cord in the developing albino rat was studied by intraperitoneal injections of strychnine sulphate. 2. The observed responses were classed as hyperexcitability and hypertonic responses, graded 1 to 4. The complete tonic seizure (grade 4 hypertonic reaction, strychnine tetanus, maximal response) was obtained in all age groups, from birth to adulthood. The responses were grouped in sequences, and two patterns were distinguished: an infant one (from birth to 3 weeks) and an adult one (from 3 weeks on). 3. All doses varied according to age. The curve obtained for the median convulsive dose falls into two parts: descending, from birth to 3 weeks, and ascending, from 3 weeks on. Each part corresponded to a sequence pattern, the descending one to the infant pattern, and the ascending one to the adult pattern. 4. From these patterns and the corresponding median effective doses, three stages of the convulsogenic maturation of the spinal cord were distinguished: immaturity, pharmacological maturity and convulsogenic maturity. 5. It is suggested that the mechanism responsible for the complete tonic seizure is fully functional from birth, while that responsible for clonic seizure only reaches full maturity at 3 weeks of age.

5 citations


Journal ArticleDOI
TL;DR: An eosinophilic index was set up and it was found that 46,81% were infested by Trichuris trichiura; 23,85% by Strongyloides stercoralis; 22,46% by Necator americanus and/or Ancylostoma duodenale; 20,51% by Ascaris lumbricoides; and 0,65% by Schistosoma mansoni.
Abstract: 1 - Foram examinadas as fezes de 2.666 individuos, operarios e funcionarios de duas Empresas industriais, situadas, uma na cidade do Rio de Janeiro e outra no Estado do Rio (Brasil); 2 - Dos 2.666 individuos, 1941 (72.80%) estavam parasitados por um ou mais helmintos e 725 (27,20%) tinham seus exames de fezes negativos; 3 - De cada um dos 2.666 individuos foi feito um hemograma completo, tendo sido aproveitada a taxa de eosinofilos que, em associacao com os exames de fezes, constituiu o objeto principal deste trabalho. 4 - Na Tabela A observa-se o numero de vezes em que cada um dos vermes foi observado e seus respectivos percentuais. Embora nao seja um trabalho de epidemiologia, verifica-se que 46,81% sao infestados pelo Trichuris trichiura; 23,85% pelo Strongyloides stercoralis; 22,46% pelo Necator americanus e/ou Ancylostoma duodenale; 20,51% pelo Ascaris lumbricoides; 1,65% pelo Schistosoma mansoni; 0.67% pelo Enterobius vermicularis; 0,26% por Taenia solium ou T. saginata e 0,11% por Hymenolepis nana; 5 - Os exames de fezes foram feitos pelos metodos de Faust (ou de Ritchie), de Willis, de Baermann e de sedimentacao; 6 - A eosinofilia anotada foi a relativa ou em seu percentual, sendo considerada hipereosinofilia uma taxa de eosinofilos igual ou superior a 5% (Eo > 5%); 7 - Foram abordados de modo conciso os fatores que provocam oscilacoes na eosinofilia normal tais como a idade, a raca, as horas do nictemero, os fatores fisicos, o sexo, os fatores quimicos e outros; 8 - Tratou-se de modo mais extenso das diferencas entre as hipereosinofilias parasitarias e nao parasitarias, tendo sido focalizada a dinâmica da eosinofilia traduzida na curva de Lavier. 9 - A distribuicao dos 2.666 casos foi feita pelos diferentes graus de eosinofilia, tendo sido levantados graficos e tracadas curvas sobre a distribuicao de cada helminto e de suas associacoes. 10 - Por ser necessario a explanacao do assunto, foi criado o "indice eosinofilico", o qual corresponde a relacao entre o numero de casos de um determinado grupo com Eo > 5% e Eo < 5%. Para o total de casos positivos, ao "indice eosinofilico" denominamos "indice eosinofilico medio" em para o total dos negativos "indice eosinofilico residual"; 11 - Estabelecendo-se o "indice eosinofilico", pode-se ajuizar a capacidade eosinofilogenica de cada helminto isoladamente, bem como a de suas associacoes; 12 - Atencao especial foi dada aos problemas da existencia da hipereosinofilia nos casos com exames coprologicos negativos para helmintos, tendo-se passado em revista varios dos aspectos biologicos que o assunto comporta; 13 - Outra questao de grande importância clinica explanada neste trabalho e a do encontro de casos de parasitismo por vermes, sem hipereosinofilia. O autor, baseado em seus dados e em outros colhidos na literatura sobre o assunto, discute a fisiopatologia da eosinopoiese nas helmintoses e ojerece uma interpretacao para este fato ainda nao defintivamente esclarecido.

3 citations



Journal ArticleDOI
TL;DR: The results suggest that 2-4 courses of therapy within a shorter span of time should be the ideal for a mass treatment campaign against hookworm, and the need for more accurate studies to determine the most efficient schedules of treatment and the real value of the drug, as compared to other antihelminthics against the two parasites under study.
Abstract: Compound 16.842 was tried with three different groups of patients in order to evaluate its tolerancy, and efficacy as well, with a view of using the drug in mass campaigns against hookworm. Group I, used for a preliminary trial, consisted of 38 patients attending an out-patient clinic, and living either in the out-skirts or in the various urban areas of the city of Rio de Janeiro, including some inmates of an orphanage. Group II, a field trial, was carried out in two farms, where the drug was administered both to the positive cases (124) and to the rest of the population (nearly 90%). Group III, a field trial was also carried out in a small town where nearly 40% of the total population was treated with the Compound. Tolerability was considered rather satisfactory, mainly among the patients receiving two single doses (50-150mg), according to the age, 4 - 6 weeks apart). These results suggest that 2-4 courses of therapy within a shorter span of time should be the ideal for a mass treatment campaign. Efficacy varied from 26.6% to 76.2% parasitological cure in the various groups, with a wide range of variation also in the percent of mean reduction of eggs for hookworm. The drug showed also some effect against Ascaris lumbricoides giving cure rates between 10,5% and 35.7% in the various groups, with a percentage reduction in mean egg counts of 27% to 83.3% according to the various groups. It was concluded that Compound 16.842 possesses a marked effect on hookworm and a mild effect on A. lumbricoides. The findings indicate the need for more accurate studies to determine the most efficient schedules of treatment and the real value of the drug, as compared to other antihelminthics against the two parasites under study.

1 citations



Journal ArticleDOI
TL;DR: As investigacoes histologicas revelaram, na medula espinhal, extensas areas de necrose, hemorragias, zonas de desmielinizacao, infiltrados linfocitarios, alem de infiltrado no bulbo e nas meninges.
Abstract: Descricao de um caso de necrose macica da medula espinhal por vacinacao antirrabica. A doenca caracterizou-se por paralisia de tipo ascendente e hipertermia. As investigacoes histologicas revelaram, na medula espinhal, extensas areas de necrose, hemorragias, zonas de desmielinizacao, infiltrados linfocitarios, alem de infiltrados linfocitarios no bulbo e nas meninges. A neuralergia explicaria o mecanismo patogenico e a distribuicao da rede arterial condicionaria a topografia das lesoes.

1 citations


Journal ArticleDOI
TL;DR: In this article, a conjunto analisado verifica-se that 74% das revistas included relatos originais, se bem that, em muitos cases, apenas um ou dois artigos por numero.
Abstract: italo Suassuna *O levantamento dos problemas da im­prensa medica no Brasil seria o passo ini­cial necessario para estabelecerem-se as perspectivas que pudessem fundamentar o seu progresso. A respeito dos periodicos brasileiros, infelizmente nao se dirpoe de uma analise global, a qual, no entanto, e parte de um levantamento realizado sob os auspicios da Uniao Pan-Americana (1) em 1962, sobre publicacoes cientificas e tec­nicas da America Latina. Essa analise cor­responde a 950 revistas cientificas sendo que um pouco mais da metade (51%) re­laciona-se com as ciencias medicas, en­quanto que apenas 3 paises — o Brasil (26%), a Argentina (20%) e o Mexico .. (13%) — contribuem com quase 60 por cento do total de revistas.No conjunto analisado verifica-se que 74% das revistas incluem relatos originais, se bem que, em muitos casos, apenas um ou dois artigos por numero. Trinta (30) por cento das revistas possuem menos de 50 paginas por numero e apenas 1/3 do numero total apresenta um indice por vo­lume . Sobre esse aspecto, e comentado que “a preparacao de indices e um dos processos que exigem mais tecnica e maio­res custos em uma revista, pelo que, a baixa proporcao das que atendem a esse requis;to, reflete, sem duvida, os orcamen­tos reduzidos e as limitacoes dos corpos de redacao de muitas delas”.Se bem possa ser comprovado qr.e o in­gles tornou-se a lingua predominante nas comunicacoes cientificas em biologia t quejunto ao frances e ao alemao correspon­dem a mais de 75% ent^-e 3 500 period - cos de biologia (2) verifica-se que 99% das publicacoes latino-americanas sao feitas em um so id.oma, obviamente o espanhol ou o portugues, os quais, segun­do informacoes disponive.s para os Esta­dos Unidos, apenas 11% dos homens de ciencia confessam conhecer (2). Noventa (90) por cento das revistas latino-america­nas pertencem a uma instiuicao, p?lo que justifica-se que 44% so aceitam contribui­coes dos membros das organizacoes a que pertencem. Irregularidades e atrasos de publicacao sao surpreend das em mais de 1/4 das revistas mensais, mas tambem pa­decem das mesmas irregularidades as pu­blicacoes arua^. No estudo em que vimos colhendo estes dados (1) comenta-se que, de forma caracteristica, o corpo de reda­cao desses periodicos e extremamente re­duzido: selecao, correcao de artigos e ou­tras funcoes editoriais, cabem a professo­res e homens de ciencia em tempo livre e amiude gratuitamente. Assim sendo, ja nao pode causar espanto que apenas 2/5 das revistas latino-americanas sejam conside­radas por, ao menos, um dos servicos in­ternacionais de indices e resumos sendo menos de 1/10 as que alcancam ser consi- d^rad^s