A família, uma estratégia para o sucesso escolar. Um estudo de caso com alunos do 2.º ano do 1.º CEB

O estudo que aqui apresentamos tem como objetivos estudar: o impacto do acompanhamento dos pais ou Encarregados de Educação no Estudo Autónomo e na realização dos Trabalhos de Casa, nos resultados escolares e na motivação para a escola e aprendizagens; ainda as necessidades sentidas pelos pais ou Encarregados de Educação ao fazerem este acompanhamento Neste estudo elaboramos seis propostas que planificamos, analisamos e, do seu desenvolvimento, tiramos as respetivas conclusões. As propostas foram dinamizadas pelo professor de turma e investigador em pequenas sessões/reuniões de esclarecimento com os pais ou Encarregados de Educação sendo quatro delas aplicadas num 2.º ano de escolaridade e as outras duas a um 3.º ano. Nas propostas do 2.º ano foram trabalhadas as frações e as estratégias de cálculo mental bem como foi dinamizado o projeto “Clube de Pais Leitores” e o “Concurso de Espantalhos” também aberto à comunidade educativa. Nas propostas do 3.º ano de escolaridade abordamos as propriedades da multiplicação, sua utilização no cálculo mental, a consolidação da operação divisão através do jogo do 24 e orientações para o Estudo Acompanhado e Trabalhos de Casa para auxiliar os pais ou Encarregados de Educação. Com a implementação destas tarefas, apresentamos os tipos de envolvimento parental solicitado por cada atividade, os benefícios para a família, aluno e professor, os sistemas envolvidos no processo de desenvolvimento da criança e os fatores que influenciaram negativamente na realização destas atividades. A implementação destas atividades foi feita seguindo uma metodologia qualitativa, inserida num contexto de um estudo de caso. Os participantes no estudo foram entrevistados com o objetivo de completar o estudo realizado através do seu feedback. Neste estudo fizemos uma revisão bibliográfica e abordámos o envolvimento dos pais ou Encarregados de Educação e famílias na escola numa perspetiva cronológica, a tipologia de envolvimento parental na escola, os sistemas que influenciam o desenvolvimento da criança e ainda uma referência aos benefícios para a comunidade educativa do envolvimento parental e familiar na escola. Através dos dados obtidos, pudemos verificar que o acompanhamento dos pais ou Encarregados de Educação no Estudo Autónomo e Trabalhos de Casa e nos projetos de turma traz bastantes benefícios para todos os elementos da comunidade educativa, sendo o aluno o mais beneficiado, e influenciado primariamente pela família em articulação com a escola e comunidade. Também verificamos que os pais ou Encarregados de Educação têm necessidades de estarem informados sobre conteúdos escolares e serem conhecedores das estratégias utilizadas na sala de aulas pelo que, sem isto, apresentam dificuldades em acompanharem os seus educados em casa. A realização deste estudo visa contribuir para a compreensão das necessidades sentidas pelos pais ou Encarregados de Educação no acompanhamento do Estudo Autónomo e Trabalho de Casa e as formas de dinamizar a cooperação entre o professor da turma e a família, promovendo o sucesso e a motivação escolar. Palavras-chave: Cooperação; Envolvimento; Família; Alunos; Escola.

Dynamics of Capillaria-hepatica-induced hepatic septal fibrosis in rats

INTRODUCTION: The pathogenesis of septal hepatic fibrosis, induced in rats by Capillaria hepatica infection, was studied with the aid of a large collection of stored paraffin blocks, representative of the different evolutive phases of fibrosis which appeared in 100% of infected rats. METHODS: Studies were conducted involving histology, immunohistochemistry, immunofluorescence and morphometric methods, in order to observe the dynamic behavior of the cellular and matrix components of fibrosis, over a one year period of evolution. RESULTS: Observation verified that septal fibrosis originates from several portal spaces simultaneously. Its origin and progression involve blood vessel proliferation (angiogenesis), multiplication of actin-positive cells (pericytes and myofibroblasts) and progressive collagen deposition. By the end of 4-5 months, a progressive decrease in all these components was observed, when signs of regression of septal fibrosis became more evident over time. CONCLUSIONS: Besides indicating the fundamental role played by angiogenesis in the pathogenesis of fibrosis, these morphological data concerning the dynamics of this C. hepatica experimental model proved to be adequate for future investigations regarding the functional aspects of fibrosis induction, progression and regression.

Desenvolvimento da fluência no cálculo mental através do uso de estratégias de cálculo: um estudo no 4.º e no 6.º ano de escolaridade

Relatório de estágio de mestrado em Ensino do 1º e 2º Ciclo do Ensino Básico

Pointlike reducibility of pseudovarieties of the form V*D

In this paper, we investigate the reducibility property of semidirect products of the form V *D relatively to (pointlike) systems of equations of the form x1 =...= xn, where D denotes the pseudovariety of definite semigroups. We establish a connection between pointlike reducibility of V*D and the pointlike reducibility of the pseudovariety V. In particular, for the canonical signature consisting of the multiplication and the (omega-1)-power, we show that V*D is pointlike-reducible when V is pointlike-reducible.

Microenxertia em castanheiro

Dissertação de mestrado em Biologia Molecular, Biotecnologia e Bioempreendedorismo em Plantas

A linear algebra approach to OLAP

Inspired by the relational algebra of data processing, this paper addresses the foundations of data analytical processing from a linear algebra perspective. The paper investigates, in particular, how aggregation operations such as cross tabulations and data cubes essential to quantitative analysis of data can be expressed solely in terms of matrix multiplication, transposition and the Khatri–Rao variant of the Kronecker product. The approach offers a basis for deriving an algebraic theory of data consolidation, handling the quantitative as well as qualitative sides of data science in a natural, elegant and typed way. It also shows potential for parallel analytical processing, as the parallelization theory of such matrix operations is well acknowledged.

Producción de factores de virulencia por fitopatógenos bacterianos de soja. Utilización de productos naturales como biocontrol. Production of virulence factors by soybean bacterial phytopathogens. The use of natural products as biocontrolers.

En Argentina el cultivo de soja ocupa el primer lugar en superficie sembrada. El 90% de la producción se obtiene en la zona central del pais. La siembra directa favorece la multiplicación y supervivencia de fitopatógenos causantes de tizón y pústula bacterianos. El tizón es producido por Pseudomonas syringae pv. glycinea observándose manchas marrones en las hojas. Produce gran variedad de toxinas: coronatina, faseolotoxina, siringomicina, tabtoxina, proteínas “nucleation ice”, entre otras, las cuales contribuyen a la clorosis y necrosis. En la infección, además, están involucrados exopolisacáridos (levano y alginato). La celulosa ha sido relacionada en la adhesión bacteriana y en la formación de biofilm. La pústula es causada por Xanthomonas axonopodis pv. glycines. Produce manchas pequeñas con una pequeña pústula de color claro. Libera enzimas como α-amilasa, proteasa, endo β-mannanasa, actividad peptolítica, que degradan componentes vegetales. Xantan, producido por X. axonopodis es uno de los componentes necesarios para la formación de biofilm. Este último es considerado un importante factor de virulencia porque proporciona una estrategia de colonización que otorga mayor resistencia a ambientes desfavorables, tolerancia a antimicrobianos, producción de metabolitos y exoenzimas, etc. Actualmente el control de bacterias fitopatógenas se realiza mediante pesticidas con alta toxicidad para los consumidores y el ambiente. Para evitar las bacteriosis en la práctica se sugiere la rotación de cultivos y utilizar semillas certificadas. Se están probando compuestos naturales derivados de plantas medicinales como pesticidas; estos se pueden dividir en varias categorías fitoquímicas. Varios estudios confirman la actividad antibacteriana, antifúngica y antiviral de estos productos. Extractos vegetales con alto contenido de flavonoides y aceite esenciales poseen una importante actividad antibacteriana. Además, algunos aceites esenciales podrían estar incidiendo en la liberación y/o producción de biofilm, exopolisacáridos y exoproteínas. La gran incidencia de las infecciones por fitopatógenos y las pérdidas económicas que estas acarrean hacen que su control presente grandes dificultades para la agricultura sustentable en soja de nuestro país. En este trabajo se propone estudiar los diferentes factores de virulencia de cepas bacterianas fitopatógenas y evaluar el rol que cumplen en el proceso de la enfermedad en cultivos de soja y desarrollar estrategias para el control de bacteriosis vegetales aplicando productos naturales aislados de plantas aromáticas. La correcta utilización de productos antimicrobianos de origen natural aplicados sobre el cultivo y/o sobre las semillas evitaría la dispersión de la enfermedad y la eliminación al medio ambiente de productos contaminantes no deseados. In Argentina, soybean cultivation occupies the first place; 90% of this cereal is produced in the central region of the country. Intensive tillage practices favour multiplication and survival of bacterial phytopathogens causing blight and pustule diseases. Pseudomonas syringae pv. glycinea produce several toxins like coronatine, faseolotoxine, siringomicine, tabtoxine and proteins of nucleation ice that contribute to the develop of chlorosis and necrosis, characteristic of bacterial blight. It also produces levan and alginate, cellulose and biofilm. Pustule disease is caused by Xanthomonas axonopodis pv glycines, which produce enzymes like α-amilase, protease, endo β-mannanase, peptolitic activity, xanthan and biofilm. Nowadays the control of phytopathogenic bacteria consists in the application of pesticides that are toxic for the environment and man. Natural products from medicinal plants are a new alternative for the treatment of phytopathogens. Researches made with phytochemical compounds (flavonoids, phenols, quinones, cummarines, essential oils, terpenes) support the antimicrobial activity of these natural products. What is more, these substances could suppress the biofilm, exoproteins and exopolisaccharides formation and release of them. The infections caused by phytopathogens provoke economical loses and its control presents big difficulties in our country. The proposal of this work is the characterization of phytopatoghenic strains, its virulence factors and the role they play in the disease process. The development of a new alternative for the control of vegetable bacteriosis using natural products obtained from aromatic plants and the correct application of them on sown fields or on seeds is also an objective in this work.

Hereditariedade da homeose

A preliminary account on the normal development of the imaginai discs in holometabolic Insects is made to serve as an introduction to the study of the hereditary homoeosis. Several facts and experimental data furnished specially by the students of Drosophila are brought here in searching for a more adequate explanation of this highly interesting phenomenon. The results obtained from the investigations of different homoeotic mutants are analysed in order to test Goldschmidt's theory of homoeosis. Critical examination of the basis on which this theory was elaborated are equally made. As a result from an extensive theoretical consideration of the matter and a long discussion of the most recent papers on this subject the present writer concludes that the Goldschmidt explanation of the homoeotic phenomena based on the action of diffusing substances produced by the genes, the "evocators", and on the alteration of the normal speed of maturation of the imaginai discs equally due to the activity of the genes, could not be proved and therefore should be abandoned. In the same situation is any other explanation like that of Waddington or Villee considered as fundamentally identical to that of Goldschmidt. In order to clear the problem of homoeosis in terms which seem to put the phenomenon in complete agreement with the known facts the present writer elaborated a theory first published a few years ago (1941) based entirely on the assumption that the imaginai discs are specifically determined by some kind of substances, probably of chemical nature, contained in the cytoplam of the cells entering in the consti- tution of each individual disc. These substances already present in the blastem of the egg in which they are distributed in a definite order, pass to different cells at the time the blastem is transformed into blastoderm. These substances according to their organogenic potentiality may be called antenal-substance, legsubstance, wing-substance, eye-substance, etc. The hipoderm of the embryo resulting from the multiplication of the blastoderm cells would be constituted by a series of cellular areas differing from each other in their particular organoformative capacity. Thus the hypoderm giving rise to the imaginai discs, it follows that each disc must have the same organogenic power of the hypodermal area it came from. Therefore the discs i*re determinated since their origin by substances enclosed in the cytoplasm of their cells and consequently can no longer alter their potentiality. When an antennal disc develops into a leg one can conclude that this disc in spite of its position in the body of the larva is not, properly speaking, an antennal disc but a true leg disc whose cells instead of having in their cytoplasm the antennal substance derived from the egg blastem have in its place the leg-substance. Now, if a disc produces a tarsus or an antenna or even a compound appendage partly tarsus-like, partly antenna-like, it follows tha,t both tarsal and antennal substances are present in it. The ultimate aspect of the compound structure depends upon the reaction of each kind of substance to the different causes influencing development. For instance, temperature may orient the direction of development either lowards arista or tarsus, stimulating, or opposing to the one or the other of these substances. Confering to the genes the faculty of altering the constitution of the substances containing in the cytoplasm forming the egg blastem or causing transposition of these substances from one area to another or promoting the substitution of a given substance by a different one, the hereditary homoeocis may be easily explained. However, in the opinion of the present writer cytoplasm takes the initiative in all developmental process, provoking the chromosomes to react specifically and proportionally. Accordingly, the mutations causing homoeotic phenomena may arise independently at different rime in the cytoplasm and in the chromosomes. To the part taken by the chromosomes in the manifestation of the homoeotic characters is due the mendalian ratio observed in homoeotic X normal crosses. Expression, in itself, is mainly due to the proportion of the different substances in the cells of the affected discs. Homoeotic phenomena not presenting mendelian ratio may appear as consequence of cytoplasmic mutation not accompanied by chromosomal mutation. The great variability in the morphology of the homoeotic characteres, some individual being changed towards an extreme expression of the mutant phenotype while others in spite of their homozigous constitution cannot be distinguished from the normal ones, strongly supports the interpretation based on the relative proportion of the determining substances in the discs. To the same interpretation point also asymetry and other particularities observed in the exteriorization of the phenomenon. In conformity with this new conception homoeosis should not prove homology of Insect appendages (Villee 1942) since a more replacement of substances may cause legs to develop in substitution of the wings, as it was already observed (requiring confirmation in the opinion of Bateson 1894, p. 184) and no one would conclude for the homology of these organs in the usual meaning of the term.

A determinação dos números de indivíduos mínimos necessários na experimentação genética

The main object of the present paper consists in giving formulas and methods which enable us to determine the minimum number of repetitions or of individuals necessary to garantee some extent the success of an experiment. The theoretical basis of all processes consists essentially in the following. Knowing the frequency of the desired p and of the non desired ovents q we may calculate the frequency of all possi- ble combinations, to be expected in n repetitions, by expanding the binomium (p-+q)n. Determining which of these combinations we want to avoid we calculate their total frequency, selecting the value of the exponent n of the binomium in such a way that this total frequency is equal or smaller than the accepted limit of precision n/pª{ 1/n1 (q/p)n + 1/(n-1)| (q/p)n-1 + 1/ 2!(n-2)| (q/p)n-2 + 1/3(n-3) (q/p)n-3... < Plim - -(1b) There does not exist an absolute limit of precision since its value depends not only upon psychological factors in our judgement, but is at the same sime a function of the number of repetitions For this reasen y have proposed (1,56) two relative values, one equal to 1-5n as the lowest value of probability and the other equal to 1-10n as the highest value of improbability, leaving between them what may be called the "region of doubt However these formulas cannot be applied in our case since this number n is just the unknown quantity. Thus we have to use, instead of the more exact values of these two formulas, the conventional limits of P.lim equal to 0,05 (Precision 5%), equal to 0,01 (Precision 1%, and to 0,001 (Precision P, 1%). The binominal formula as explained above (cf. formula 1, pg. 85), however is of rather limited applicability owing to the excessive calculus necessary, and we have thus to procure approximations as substitutes. We may use, without loss of precision, the following approximations: a) The normal or Gaussean distribution when the expected frequency p has any value between 0,1 and 0,9, and when n is at least superior to ten. b) The Poisson distribution when the expected frequecy p is smaller than 0,1. Tables V to VII show for some special cases that these approximations are very satisfactory. The praticai solution of the following problems, stated in the introduction can now be given: A) What is the minimum number of repititions necessary in order to avoid that any one of a treatments, varieties etc. may be accidentally always the best, on the best and second best, or the first, second, and third best or finally one of the n beat treatments, varieties etc. Using the first term of the binomium, we have the following equation for n: n = log Riim / log (m:) = log Riim / log.m - log a --------------(5) B) What is the minimun number of individuals necessary in 01der that a ceratin type, expected with the frequency p, may appaer at least in one, two, three or a=m+1 individuals. 1) For p between 0,1 and 0,9 and using the Gaussean approximation we have: on - ó. p (1-p) n - a -1.m b= δ. 1-p /p e c = m/p } -------------------(7) n = b + b² + 4 c/ 2 n´ = 1/p n cor = n + n' ---------- (8) We have to use the correction n' when p has a value between 0,25 and 0,75. The greek letters delta represents in the present esse the unilateral limits of the Gaussean distribution for the three conventional limits of precision : 1,64; 2,33; and 3,09 respectively. h we are only interested in having at least one individual, and m becomes equal to zero, the formula reduces to : c= m/p o para a = 1 a = { b + b²}² = b² = δ2 1- p /p }-----------------(9) n = 1/p n (cor) = n + n´ 2) If p is smaller than 0,1 we may use table 1 in order to find the mean m of a Poisson distribution and determine. n = m: p C) Which is the minimun number of individuals necessary for distinguishing two frequencies p1 and p2? 1) When pl and p2 are values between 0,1 and 0,9 we have: n = { δ p1 ( 1-pi) + p2) / p2 (1 - p2) n= 1/p1-p2 }------------ (13) n (cor) We have again to use the unilateral limits of the Gaussean distribution. The correction n' should be used if at least one of the valors pl or p2 has a value between 0,25 and 0,75. A more complicated formula may be used in cases where whe want to increase the precision : n (p1 - p2) δ { p1 (1- p2 ) / n= m δ = δ p1 ( 1 - p1) + p2 ( 1 - p2) c= m / p1 - p2 n = { b2 + 4 4 c }2 }--------- (14) n = 1/ p1 - p2 2) When both pl and p2 are smaller than 0,1 we determine the quocient (pl-r-p2) and procure the corresponding number m2 of a Poisson distribution in table 2. The value n is found by the equation : n = mg /p2 ------------- (15) D) What is the minimun number necessary for distinguishing three or more frequencies, p2 p1 p3. If the frequecies pl p2 p3 are values between 0,1 e 0,9 we have to solve the individual equations and sue the higest value of n thus determined : n 1.2 = {δ p1 (1 - p1) / p1 - p2 }² = Fiim n 1.2 = { δ p1 ( 1 - p1) + p1 ( 1 - p1) }² } -- (16) Delta represents now the bilateral limits of the : Gaussean distrioution : 1,96-2,58-3,29. 2) No table was prepared for the relatively rare cases of a comparison of threes or more frequencies below 0,1 and in such cases extremely high numbers would be required. E) A process is given which serves to solve two problemr of informatory nature : a) if a special type appears in n individuals with a frequency p(obs), what may be the corresponding ideal value of p(esp), or; b) if we study samples of n in diviuals and expect a certain type with a frequency p(esp) what may be the extreme limits of p(obs) in individual farmlies ? I.) If we are dealing with values between 0,1 and 0,9 we may use table 3. To solve the first question we select the respective horizontal line for p(obs) and determine which column corresponds to our value of n and find the respective value of p(esp) by interpolating between columns. In order to solve the second problem we start with the respective column for p(esp) and find the horizontal line for the given value of n either diretly or by approximation and by interpolation. 2) For frequencies smaller than 0,1 we have to use table 4 and transform the fractions p(esp) and p(obs) in numbers of Poisson series by multiplication with n. Tn order to solve the first broblem, we verify in which line the lower Poisson limit is equal to m(obs) and transform the corresponding value of m into frequecy p(esp) by dividing through n. The observed frequency may thus be a chance deviate of any value between 0,0... and the values given by dividing the value of m in the table by n. In the second case we transform first the expectation p(esp) into a value of m and procure in the horizontal line, corresponding to m(esp) the extreme values om m which than must be transformed, by dividing through n into values of p(obs). F) Partial and progressive tests may be recomended in all cases where there is lack of material or where the loss of time is less importent than the cost of large scale experiments since in many cases the minimun number necessary to garantee the results within the limits of precision is rather large. One should not forget that the minimun number really represents at the same time a maximun number, necessary only if one takes into consideration essentially the disfavorable variations, but smaller numbers may frequently already satisfactory results. For instance, by definition, we know that a frequecy of p means that we expect one individual in every total o(f1-p). If there were no chance variations, this number (1- p) will be suficient. and if there were favorable variations a smaller number still may yield one individual of the desired type. r.nus trusting to luck, one may start the experiment with numbers, smaller than the minimun calculated according to the formulas given above, and increase the total untill the desired result is obtained and this may well b ebefore the "minimum number" is reached. Some concrete examples of this partial or progressive procedure are given from our genetical experiments with maize.

Propagação da samambaia-de-metro

The author studied the possibility of propagating "Samambaia de Metro" Polypodium Subauriculatum, by means of spores, since vegetative multiplication is hard to obtain for large numbers of plants. Five treatments were tried, with 4 replications. I - Coarse "Flores Floor" and fine "Flores Floor". II - Coarse Flores Floor and moss. III - Coarse sand, Flores Floor and brick powder VI - Coarse sand, Flores Floor and brick powder V - Coarse sand and Flores Floor. The best germination was obtained with treatment V (Coarse sand et the boltom), topesed by Flores Floor. The pots were permanently kept on a tray pul of water, in a Greenhouse. This method provided over 4.000 offspring, which at 2 ½ years of age were of a size mitable for ornamental use.

Toxoplasmose congênita

We had the opportunity to study 6 cases of the congenital form of toxoplasmosis, found in a series of 1200 necropsies of fetuses and newborn babies, realized at 3 different hospitals in Rio de Janeiro, Brazil. Among the 6 cases, 4 were premature babies liveborn at the 6th-8th gestational month and 2 were stillborn (1 premature and 1 at term). In all those cases, the diagnosis was based in the detection of the parasite in tissues and in one case it was even isolated the Toxoplasma from the necrotic material found in the cranial cavity. This strain of Toxoplasma, pathogenic to pigeons, to guinea pigs and to mice, is preserved by successive transfers in mice. Some facts observed in those cases present an interest not only strictly anatomic but also have certain value for the better acknowlegment of the disease. First, we want to call the attention to the presence of a sudden high fever, during or just before pregnancy in the 4 cases in which the maternal anamnesis was perfectly studied; this fever that was preceded by a normal beginning of pregnancy, had relatively rapid remission, but in 2 cases was immediately followed by uterine bleeding and premature delivery, although the puerperium had been apparently normal. It is known that are normal the subsequent children of the mothers that delivered a baby with toxoplasmosis and that several women have normal babies before the toxoplasmotic one. We believe that the fever observed in our cases could be indicative of the beginning of maternal infection and those are the reasons why we emphasize the need of careful anamnesis, specially in the cases actually diagnosed as inapparent infection. Another fact to notice is that in 5 of our cases the event premature delivery happened always between the 6th and the 8th months of pregnancy, and the only term fetus was delivered in advanced stage of maceration. The above mentioned facts could agree with the opinion of FRENKEL (1949), when he declared that "primary infection of the pregnant mother appears more likely to be the commoner mode of fetal toxoplasmic infection", but they would disagree with WEINMAN (1952) who believes that the transmission of Toxoplasma to the fetus is more frequent through a pregnant woman with chronic disease and who says "that infection contracted during pregnancy may and probably does happen from time to time"...Still in connection with the transmission of toxoplasmosis, we want to note the verification of inflammatory lesions in the placental villi and in the umbilical cord in 3 of the 4 cases in which such organs were examined at the microscope. In the case n. 1, we found several pseudocysts of Toxoplasma in the placenta, and the fibroblasts of Wharton's jelly were particularly rich in isolated forms and in colonies of Toxoplasma; the easy multiplication of the parasite in that tissue calls the attention and even suggests its utilisation for Toxoplasma's cultivation. The confirmation of Toxoplasma in human placenta was made only recently by CRISTEN et al. (1951) and by NEGHME et al. (1952), in Chile; it is not frequent in the literature, what gives some value to our present verification. Another observation was that provided by the case n. 6. This baby, a premature one of the 6th month, was 14 days old and-died with signs of respiratory disease, the causa mortis have been pneumonia. At the necropsy, we found no gross change that suggested toxoplasmosis, except the presence of some small necrotic focuses in the cerebral nervous substance around the ventricles. As a matter of fact, there was no enlargement of spleen or liver and neither leptomeningitis nor hydrocephalus. Such focuses were attributed to possible anoxia and in fact they are extremely similar to anoxial softenings, even when they are examined at the microscope; its structure composed of a central necrotic zone, surrounded by proliferated neuroglia and by a variable deposit of calcium salts, closely simulated the anoxial softenings, when the microscopical examination is based in the common histological preparations (hematoxilin-eosin, etc.). But when we examine preparations by the Giemsa or by the periodic acid-Schiff methods, we will note the presence of Toxoplasma, with its typical aspect or a little changed by degeneration. When we describe this observation, we wish to evidence the need of the search of Toxoplasma and closed parasites, in the cases of supposed pure anoxial softenings of nervous substance, in children. The frequency with which the congenital toxoplasmosis was anatomically verified should be emphasized, although the disease had not been clinically suspected, and it should be borne in mind that the second case of toxoplasmosis reported in the world was observed in Brazil by MAGARINOS TORRES; this case was the first to be described of the generalized congenital form of the infection, i. e. with myocardial lesions and parasites in skeletal muscles and skin.

A reação de fixação do complemento no estudo do vírus da gripe asiática

Dada a importância da reação de fixação do complemento no estudo do vírus da gripe, resolvemos aplicá-la ao exame e inúmeras amostras que isolamos no decurso da epidemia de gripe asiática, ocorrida em 1957, no Brasil. As referidas amostras já haviam sido estudadas pela prova de hemaglutinação, que serviu para diagnosticá-las. Sabemos que, pela reação de fixação do complemento, se define o tipo de qualquer amostra, não a variante, isto é, os antígenos A, A1 e A2 fixam o complemento, indiferentemente, em presença de anticorpos A, A1 e A2. Não o fazem com o tipo B, C ou D. Tal separação só é possível com a prova de hemaglutinação, que havíamos anteriormente praticado. Visamos, no presente trabalho, por meio daquela reação, estabelecer as relações entre os antígenos de amostras padrões com soros por nós preparados, pela inoculação das amostras que isolamos, ao lado dos soros preparados com as amostras padrões. Foram empregadas as variantes do tipo A e o tipo B. O antígeno foi preparado com o líquido cório-alantóide contendo razoável taxa de hemaglutininas para cada amostra do vírus. Os imunesoros foram preparados em galos, pela injeção do líquido alantóide contendo vírus. A técnica empregada na reação foi a do Centro Internacional de Estudo da gripe, ramo das Américas, localizado em Montgomery. Verificamos, pelos resultados obtidos, assinalados nos Quadros 8 e 9, que separamos nìtidamente o tipo A do B, mas não as variantes do tipo A, em sentido absoluto, uma vez que qualquer dos seus antígenos, A, A1 ou A2, apresentou a reação positiva se bem que houvesse diferença, às vêzes bastante acentuada, na intensidade da reação. Sempre que se usou o antígeno da variante A2 a reação foi 8 a 16 vêzes mais forte, em comparação com os antígenos das variantes A e A1. Em raros casos, a reação foi negativa com êstes antígenos. Verificamos, portanto, a perfeita individualidade da variante A2, para isso trabalhando com 17 das 43 amostras que isolamos no decorrer da última pandemia de gripe.

Notas de ixodologia: IX. O complexo ovale do gênero Amblyomma

It was impossible to confirm either WARBUTON's conservative nor TONELLI RONDELLI's opposite belief on the number of valid species after studying many lots of ticks of the ovale group, mainly from Brazil. Two species are recognized: Amblyomma ovale Koch, 1844 and Amblyomma aureolatum (Pallas, 1772), corresponding respectively to A. fossum Neumann, 1898 and A. stratum Koch, 1844. A list of synonyms is presented. Both species are redescribed and intraspecific morphological variation show to be the cause of the multiplication of species by those working with insufficient material. Color plates of both species are presented and hosts and localities of captures are recorded.

Trypanosoma cruzi: antigen-receptor mediated endocytosis of antibody

Trypanomastigote forms of Trypanosoma cruzi were derived from tissue culture and incubated with immune and non-immune human sera. All immune sera showed high titers of specific humoral antibodies of the IgM or the IgG type. Agglutination and swelling of parasites were observed after incubation at 37ºC, but many trypomastigotes remained free-swimming in the sera for two to three days. The quantitiy of immune serum capable of lysing a maximum of 10 x 10 [raised to the power of 6] sensitized red cells was not capable of lysing 4 x 10 [raised to the power of 3] tripomastigotes. Typically, the parasites underwent cyclical changes with the formation of clumps of amastigotes and the appearance of epimastigote forms. Multiplication of the parasites was observed in immune sera. Further, the infectivity of the parasites to susceptible mice was not lost. All sera used produced similar general effects on the growth of the parasite. The antibody bound to T. cruzi appeard to enter cells by antigen-receptor mediated endocytosis. The ferritin-conjugated antibody was internalized and delivered to phagolysosomes where they might be completely degraded to amino-acids. This seemed to be a coupled process by which the immunoglobulin is first bound to specific parasite surface receptor and then rapidly endocytosed by the cell.

Interactions between Leishmania mexicana mexicana promastigotes and amastigotes and murine peritoneal macrophages in vitro

Unstimulated adherent mouse peritoneal cells were cultured in vitro and infected with equal numbers of a single strain of Leishmania m. mexicana amastigotes (AM), virulent promastigotes (VP), avirulent promastigotes (AVP) and fixed promastigotes (FP). Duplicate May-Grünwald-Giemsa stained coverslips were examined at time intervals up to 13 days. By 3 hr post infection, the number of macrophages containing parasites varied between 60.5% (VP) and 84% (AM) for macrophages exposed to living parasites, compared to 6.5% for macrophages exposed for FP. However, variable numbers of parasites showed degenerative changes by 3 hr, and the number of macrophages containing morphologically intact parasites varied significantly between cells infected with AM (84%) and those infected with VP (42%) or AVP(40%). The mean number on intacte parasites/macrophage also differed significantly between AM-infected cells and living or fixed promastigotes-infected cells. Quantitation of intact and degenerated parasites indicated parasite multiplication, as well as destruction, in VP-infected cells and parasite survival and multiplication in AM-infecte monolayers; in contrast no evidence of parasite multiplication was seen in AVP-infected cells. Changes in the mono layer itself (cell loss and macrophage vacuolization) were also evaluated. These results suggest that crucial events determining the outcome of infection occur in the host-parasite relationship during the fist 24 hours of infection. These events are apparently influenced not only by parasite or host strain but by environmentally induced variation within a given strain.