Influence of light conditions on adult mortality and egg-laying of Triatoma brasiliensis neiva, 1911 (Hemiptera: Reduviidae: Triatominae)

We compared, for Triatoma brasiliensis, the egg-laying process and the mortality of adults under conditions of almost permanent darkness and with normal laboratory luminosity. Mortality did not differ between groups. The egg-laying per vial and per female was significantly greater in the group of normal luminosity. We consider that it is not recommendable to keep the adults of this species under complete darkness. Other biological aspects should be analysed in relation to luminosity.

Hepatitis B virus surface antigen (HBsAg) and antibody (anti-HBs) forming immune complexes in fulminant hepatitis

This paper reports an unusual pattern of serological HBV markers and the presence of HBsAg/anti-HBs immune complexes in serum samples from two patients with fulminant hepatitis from the Brazilian Western Amazon Basin. The diagnosis was made by both serologic tests and demonstration of antigen/antibody complexes by transmission electron microscopy. Concurrent Delta virus superinfection is also discussed.

Business model analysis of Mobitto: How to solve the chicken and egg problem of a multi-sided platform?

A Work Project, presented as part of the requirements for the Award of a Masters Degree in Management from the NOVA – School of Business and Economics

Avaliação hematológica e histopatológica de camundongos BALB/c e C57BL/6 expostos aos antígenos recombinantes Cytoplasmic Repetitive Antigen e Flagellar Repetitive Antigen de Trypanosoma cruzi

Os antígenos recombinantes Cytoplasmic Repetitive Antigen e Flagellar Repetitive Antigen de Trypanosoma cruzi foram inoculados em camundongos BALB/c e C57BL/6 e o seu efeito avaliado a nível hematológico e histopatológico. Os resultados mostraram que o padrão histológico normal dos órgãos e o perfil hematológico dos camundongos não foram modificados sugerindo que esses antígenos não parecem causar dano ao animal.

Comparative clinical and ultrasound study of egg-negative and egg-positive individuals from Schistosoma mansoni low morbidity endemic areas, and hospitalized patients with hepatosplenic disease

Two hundred and twenty three subjects from a Schistosoma mansoni low morbidity endemic area and nine hospitalized hepatosplenic patients were submitted to stool test and clinical examination and abdomen ultrasound assessments. According to stool examination and ultrasound results, they were grouped as follows: G1 - 63 Schistosoma mansoni egg-negative individuals; G2 - 141 egg-positive patients and without evidence of periportal fibrosis; G3 - 19 egg-positive patients with periportal echogenicity (3-6mm); and G4 - 9 hepatosplenic patients with periportal echogenicity (> 6mm). Hepatomegaly detected by physical examination of the abdomen evaluated in the midclavicular line was verified in G1, G2 and G3, respectively, in 11.1, 12.1 and 26.3%. In G1, G2 and G3, periportal thickening occurred only in schistosomal patients (8.5%). Mild pathological alterations in patients that cannot yet be detected by clinical examination were detectable in the liver by ultrasound and can be due to fibrosis. The degree of mild periportal fibrosis was diminished in 57.9% of patients 12 months after treatment of schistosomiasis with oxamniquine. At ultrasonography, the mean liver left lobe measurement of G3 was larger than that of G1, and that of G4 larger than that of G1 and G2. The mean size of the spleen of G4 was significantly larger than that of the other three groups, and that of G3 larger than that of G1 and G2.

In vitro maintenance of Angiostrongylus costaricensis does not provide physiological conditions for egg laying

Fifteen pairs (male/female) of Angiostrongylus costaricensis were kept in vitro in Waymouth medium for three days to evaluate the amount and duration of egg laying. At 24, 48 and 72 hours, the mean egg counts were 321, 24 and 4 eggs/10 microliters, respectively. Most of the eggs were eliminated within the first 24 hours, suggesting they are expelled under non-physiological conditions. These results indicate that in vitro conditions are not appropriate for drug trials of egg-laying inhibitors for treatment of abdominal angiostrongylosis.

Standardization of an ELISA test using a recombinant nucleoprotein from the Junin virus as the antigen and serological screening for arenavirus among the population of Nova Xavantina, State of Mato Grosso

INTRODUCTION: Arenavirus hemorrhagic fever is a severe emerging disease. METHODS: Considering that the levels of antibodies against arenavirus in the Brazilian population are completely unknown, we have standardized an ELISA test for detecting IgG antibodies using a recombinant nucleoprotein from the Junin virus as the antigen. This protein was obtained by inserting the gene of the Junin virus nucleoprotein into the genome of Autographa californica nucleopolyhedrovirus, using the Bac-to-Bac baculovirus expression system. This recombinant baculovirus was used to infect S. frugiperda cells (SF9). RESULTS: The infection resulted in synthesis of high concentrations of recombinant protein. This protein was detected on 12.5% polyacrylamide gel and by means of Western blot. Using the standardized ELISA test, 343 samples from the population of Nova Xavantina were analyzed. We observed that 1.4% of the serum samples (five samples) presented antibody titers against arenavirus. CONCLUSIONS: These results show the population studied may present exposure to arenavirus infection.

The absence of the human platelet antigen polymorphism effect on fibrosis progression in human immunodeficiency virus-1/hepatitis C virus coinfected patients

AbstractINTRODUCTION:Hepatic fibrosis progression in patients with chronic hepatitis C virus infections has been associated with viral and host factors, including genetic polymorphisms. Human platelet antigen polymorphisms are associated with the rapid development of fibrosis in HCV-monoinfected patients. This study aimed to determine whether such an association exists in human immunodeficiency virus-1/hepatitis C virus-coinfected patients.METHODS:Genomic deoxyribonucleic acid from 36 human immunodeficiency virus-1/hepatitis C virus-coinfected patients was genotyped to determine the presence of human platelet antigens-1, -3, or -5 polymorphisms. Fibrosis progression was evaluated using the Metavir scoring system, and the patients were assigned to two groups, namely, G1 that comprised patients with F1, portal fibrosis without septa, or F2, few septa (n = 23) and G2 that comprised patients with F3, numerous septa, or F4, cirrhosis (n = 13). Fisher's exact test was utilized to determine possible associations between the human platelet antigen polymorphisms and fibrosis progression.RESULTS:There were no deviations from the Hardy-Weinberg equilibrium in the human platelet antigen systems evaluated. Statistically significant differences were not observed between G1 and G2 with respect to the distributions of the allelic and genotypic frequencies of the human platelet antigen systems.CONCLUSION:The greater stimulation of hepatic stellate cells by the human immunodeficiency virus and, consequently, the increased expression of transforming growth factor beta can offset the effect of human platelet antigen polymorphism on the progression of fibrosis in patients coinfected with the human immunodeficiency virus-1 and the hepatitis C virus.

Communal egg laying by Gonatodes humeralis (Sauria, Gekkonidae) in Manaus primary and secondary forest areas

Communal nesting has been registered for a number of lizard species at different sites. Here it is described communal egg laying of Gonatodes humeralis at different sites near and in human buildings in the period between 1990 and 1998. All these communal nests have been found in the dry season, between April and July, suggesting that the nests of are more common in this season, when the activity of their predators is less intense and the reduction of humidity diminish the decomposition action of the fungi that may kill the eggs.

Five egg-laying queens in a single colony of brazilian stingless bees (Melipona scutellaris Latreille

Polygyny, characterized by the presence of several egg-laying queens, is considered as a temporary colony status. In stingless bees it is rarely observed. This paper reports the first case of natural polygyny in Melipona scutellaris colony, with five egg-laying queens.

Ostrich egg-shell cups of Mesopotamia and the ostrich in ancient and modern times / by Berthold Laufer. 9 plates and 10 text-figures.

no.23(1926)

A fossil egg from South Dakota / by Oliver Cummings Farrington.

v.1:no.5(1899)

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.