In vitro detection of hepatitis C virus in platelets from uninfected individuals exposed to the virus

Introduction ,,,,,Despite hepatocytes being the target cells of hepatitis C virus (HCV), viral ribonucleic acid RNA has been detected in other cells, including platelets, which have been described as carriers of the virus in the circulation of infected patients. Platelets do not express cluster differentiation 81 CD81, the main receptor for the virus in hepatocytes, although this receptor protein has been found in megakaryocytes. Still, it is not clear if HCV interacts with platelets directly or if this interaction is a consequence of its association with megakaryocytes. The aim of this study was to evaluate the interaction of HCV with platelets from non-infected individuals, after in vitro exposure to the virus. ,,,, ,,,, ,,,,,Methods ,,,,,Platelets obtained from 50 blood donors not infected by HCV were incubated in vitro at 37°C for 48h with serum containing 100,000IU∕mL of genotype 1 HCV. After incubation, RNA extracted from the platelets was assayed for the presence of HCV by reverse transcription – polymerase chain reaction RT-PCR. ,,,, ,,,, ,,,,,Results ,,,,,After incubation in the presence of virus, all samples of platelets showed HCV RNA. ,,,, ,,,, ,,,,,Conclusions ,,,,,The results demonstrate that, in vitro, the virus interacts with platelets despite the absence of the receptor CD81, suggesting that other molecules could be involved in this association.

Desempenho reprodutivo e zootécnico e deposição de lipídios nos hepatócitos de fêmeas de tilápia-do-nilo alimentadas com rações de diversos níveis energéticos

Um experimento foi conduzido com o objetivo de avaliar os desempenhos reprodutivo e zootécnico e a deposição de lipídios no tecido hepático de fêmeas de tilápia-do-nilo alimentadas com rações contendo diferentes níveis de energia digestível, obtidos pela inclusão de óleo de soja. Foram utilizados 100 reprodutores e 300 reprodutoras, distribuídos em delineamento inteiramente casualizado com cinco tratamentos e quatro repetições. Os reprodutores, machos e fêmeas, foram alimentados com rações contendo, por quilograma, 35% de proteína bruta e 2.700, 2.950, 3.200, 3.450 ou 3.700 kcal de energia digestível. Os animais foram mantidos em hapas por 93 dias. O desempenho reprodutivo e zootécnico não foi influenciado pelos níveis energéticos das rações, o que pode estar relacionado ao curto período de tempo de alimentação com as dietas experimentais. Contudo, o aumento nos níveis de energia teve efeito linear nas deposições lipídicas nos hepatócitos. Desta forma, os níveis crescentes de energia digestível nas rações fornecidas às fêmeas de tilápia-do-nilo, obtidos pela inclusão de óleo de soja, apenas aumentam o tempo de sobrevivência das larvas ao jejum e a deposição de lipídios nos hepatócitos das fêmeas.

Níveis de energia digestível sobre os desempenhos reprodutivo e zootécnico e a deposição de lipídios nos hepatócitos de machos de tilápia-do-nilo

O experimento foi conduzido com o objetivo de avaliar o desempenho reprodutivo e zootécnico e a deposição de lipídios no tecido hepático de machos de tilápia-do-nilo alimentados com rações contendo diferentes níveis de energia digestível, obtidos com a inclusão de óleo de soja. Foram utilizados 400 reprodutores (300 fêmeas e 100 machos) distribuídos em delineamento inteiramente casualizado, composto de cinco níveis de energia digestível (2.700, 2.950, 3.200, 3.450 e 3.700 kcal.kg de ração-1) e quatro repetições. Os reprodutores foram alimentados com rações contendo 35% de proteína bruta e submetidos ao manejo reprodutivo em hapas por 101 dias. O melhor resultado de concentração espermática e percentual de espermatozoides normais foram obtidos para reprodutores alimentados com rações contendo 3.465,56 e 3.443,43 kcal. kg de ração-1, que produziram 7,98 × 10(9) espermatozoides.mL de sêmen-1 e 38,98% de espermatozoides normais, respectivamente. A produção de sêmen, o pH seminal, o índice de sobrevivência espermática e o tempo de ativação espermática não foram afetados pelos níveis energéticos das rações. Os níveis de energia das rações não influenciaram o desempenho zootécnico dos peixes, mas promoveram aumento linear na deposição de lipídios nos hepatócitos e afetaram a qualidade seminal, estimulando a produção de espermatozoides e a melhora dos índices de normalidade da morfologia espermática em níveis energéticos próximos a 3.450 kcal. kg de ração-1.

Liver lesions produced by aflatoxins in Rana catesbeiana (bullfrog)

This study describes alterations induced in Rana catesbeiana (bullfrog) liver after extended dietary exposure to aflatoxins (AFs). Bullfrogs of both sexes were fed for 120 days a commercial chow blended with a rice bran-based mixture of Al's containing 667.0, 11.65, 141.74, and 3.53 mg/kg of AFs B1, B2, G1, and G2, respectively. Animals were sacrificed on study days 45, 90, and 120. Severe and progressive liver lesions with structural collapse, increased hepatocyte and biliary duct cell proliferation, appearance of basophilic hepatocytes, and diffuse scarring, were observed at all time points. There were no quantitative alterations in the liver melanomacrophage centers of the AFs-exposed animals. Increased amounts of lipid hydroperoxides, indicative of ongoing oxidative stress, were more evident in the Addutor magnum muscle than in the AFs-damaged livers. No tumors were found in the R. catesbeiana livers after 120 days of exposure to relatively high doses of AFs. (c) 2006 Elsevier B.V. All rights reserved.

Estudo experimental sobre a intoxicação de Gallus gallus domesticus com semente de crotalaria spectabilis. II efeito em aves na fase final de crescimento

This study was undertaken to investigate the toxic effect of Crotalaria spectabilis seeds added to the ration for commercial broilers during the final phase of growth. Ground seeds were added at different concentrations to the ration: 0.0% (control), 0.01%, 0.1% and 0.4%. Rations containing 0.4% caused symptoms of intoxication, beginning in the second week of the study. During the third week birds showed bristling, apathy, general weakness, distended abdomen and agglomeration. In the fourth week, four animals died. Necropsy revealed prominent ascites and severe lesions of liver, kidney and lung. Microscopic examination revealed necrosis of hepatocytes, inflammatory cell infiltration, hypertrophy and hyperplasia of biliary duct cells leading to atresia and cholestasis. Prominent cartilaginous and osseous nodules in the lungs were also present as well as degenerative, changes in the kidney tubules and necrosis of cells of the bursa. All the broilers receiving a ration with 0.1% of Crotalaria seeds showed ascites and slight lesions of the liver. The remaining groups showed no reduction in weight gains, lesions or clinical symptoms. It is concluded that broilers during the final phase of growth are sensitive to administrations of seeds of C. spectabilis in their ration. The presence of ascites and cartilaginous and osseous nodules in the lungs of the affected birds was also considered important.

Annexin-A1 gene expression during liver development and post-translation modification after experimental endotoxemia

Objective and design: We have previously reported a role for annexin-A1 in liver proliferation and tumorogenicity as well as its action as an acute phase protein in a model of endotoxemia in interleukin-6 null mice.Material and methods: In this study, we have investigated the analysis of the gene and protein expression in annexin-A1 null mice and the wild type livers during foetal and adult life, and in the presence of a proinflammatory stimulus.Results: The data indicate a link between the expression of the annexin-A1 as serine-phosphorylated-protein during early events of the inflammatory response and as tyrosine-phosphorylated-form at later time-points, during the resolution of inflammation.Conclusions: The study of annexin-A1 post-translation modification may promote a new annexin-A1 peptide discovery programme to treat specific pathologies.

Liver HLA-G expression is associated with multiple clinical and histopathological forms of chronic hepatitis B virus infection

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Fetal and maternal lesions of cyanide dosing to pregnant goats

The present work evaluated the pathological effects in both dams and their fetuses of cyanide ingestion during pregnancy using goat as animal model. From the Day 24 of pregnancy, three pregnant goats were dosed by gavage with 3.0 mg KCN/kg bw/day, and two others received only tap water. All dams were euthanized and necropsied at Day 120 of pregnancy. The fetuses were examined carefully for gross abnormalities. Determinations of cyanide and thiocyanate were performed in maternal and fetal blood and in amniotic fluid. Samples of several organs were collected for histopathologic evaluation. No clinical changes were seen in any animal throughout the pregnancy. No malformations or dead fetuses were observed: however, placenta from one treated goat presented increased cotyledon surface area occupied by vascular lumina. Histological lesions in KCN-treated dams consisted of vacuolation of hepatocytes and thyroid follicular cells, increased number of vacuoles on thyroid follicular colloid. and spongiosis of cerebral, internal capsule, and cerebellar peduncles tracts. Fetuses from these mothers showed vacuolation of hepatocytes and thyroid follicular cells, and spheroids in the cerebellar white matter. Levels of cyanide and thiocyanate were higher in maternal than fetal blood, which suggests that these substances were largely but not freely transferred from mothers to fetuses. (C) 2009 Elsevier B.V. All rights reserved.

Abamectin affects the bioenergetics of liver mitochondria: A potential mechanism of hepatotoxicity

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Morfologia do figado da paca (Cuniculus Paca, Linnaeus 1766)

The elements related to the morphology of the liver of paca (Cuniculus paca), the second largest rodent of the Brazilian fauna, were observed; this species present zootechnical potential. Eight animals from the animals sector of Faculdade de Ciencias Agrarias e Veterinarias - Campus of Jaboticabal - UNESP, which is duly certified by IBAMA as an experimental breeding institute, were used. Through a dissection procedure, it was found that the liver of the paca is located in the cranial portion of the abdomen, immediately after the diaphragm, to which it is connected by the triangular, coronary, and falciform ligaments, having its bigger part located right to the medium plan. The liver of this rodent presents the following lobation: right lateral lobe, right medial lobe, quadrate lobe, left medial lobe, and left lateral lobe, besides the caudate lobe formed by the papillary process of caudate lobe and the caudate process of caudate lobe. Gallbladder is located between the quadrate and right medial lobes. Fragments of this organ were collected, fixed, and histologically prepared, being the samples analyzed through light microscopy. It was microscopically observed that intralobular connective tissue is scarce, basically it consists polyhedral hepatocytes organized into cords interposed between sinusoids and the portal triads are found in the lobe, consisting of the portal vein, hepatic artery, and biliary duct.

Liver response to low-hexachlorobenzene exposure in protein- or energy-restricted rats

The individual effects of protein deficiency and energy restriction on liver response to low-hexachlorobenzene (HCB) exposure were investigated in adult male Wistar rats. In rats fed either the low-protein or control diet, the only effect caused by HCB was a decrease in paralysis time following an ip injection of zoxazolamine. This decrease was similar for both groups. In the animals subjected to energy restriction, HCB induced a greater decrease in paralysis time, an increase in the size of centrilobular hepatocytes, a lower liver DNA content and an increased concentration of HCB in the adipose tissue, compared with the control and protein-deficient groups. Our data suggest that energy restriction increases liver response to HCB, while protein deficiency does not impair the hepatic reaction to small doses of HCB exposure.

Long-term starvation effects on Mus musculus hepatocyte nuclear phenotypes

Starvation is a physiologic stress and can significantly alter the structure of hepatic cells. This work aims to detect morphological changes in mice hepatocyte under starvation physiologic stress, based on silver staining technique. Fourteen 21 day old male mice (Mus musculus) were used, 5 as control, 5 submitted to 72 hours of starvation, and 4 were refed during 72 hours after 72 hours of starvation. After liver imprint, 15 nuclei per mouse and their respective nucleoli were outlined in millimetric paper and their areas were obtained. The results, in mm2, were transformed into μm2. The number of nucleoli per nuclei were also counted. After starvation, a statistically significant rise in nuclear and nucleolar areas occurred and no significant increase in the number of nucleoli was observed. The refeeding caused a partial recovery of the nuclear area, no significant change in the nucleolar area and a statistically significant increase in the number of nucleoli. Therefore, starvation can be considered as a modifier agent of the chromatinic structure, leading to an increase of the nuclear and nucleolar areas probably due to an increment of RNA and protein synthesis. The recovery of the stress (refeeding) did not presented a decrease of nucleolar area and evidenced a nucleoli fragmentation, probably to increase more the protein synthesis and/or due to its cycle during the interphase.

Estudo morfológico do tecido hepático de Leporinus macrocephalus

The objective of this work was to analyze the liver of Leporinus macrocephalus at the macroscopic and histologic level by evaluating the characteristics of the hepatic tissue. The fishes from a fishery in Bauru, S.P., were collected and sacrificed by destroying the spinal cord; afterwards the collected hepatic tissue was fixed and followed by histological routine. Macroscopic analysis of L. macrocephalus liver showed an organ of homogeneous structure, with red-brown color, located in the medial region of the body, caudal to heart and after the gills. It showed 3 pyramidal lobes, one central and two lateral right and left. The histological analysis showed the hepatic tissue constituted by hepatocytes cords surrounded by sinusoids, named muralium duplex. It yet revealed the diffused, distribution bile system by hepatic parenchyma, showing ducts with simple cubic epithelium, surrounded by muscular fibres and connective tissue. Cells of the exocrine pancreatic tissue were observed surrounding blood vessels in acinar arrangement as zymogen granules. Furthermore, there are melanomacrophages centers distributed along the hepatic parenchyma, preferably next to the blood vessels, constituted by cells accumulating material, such as melanin and lipofucsin, whose presence may be related to the nutritional status of the fish.

Analysis of DNA damage induced by aflatoxin B1 in Dunkin-Hartley guinea pigs

Aflatoxin B1 (AFB1) is among the most potent naturally occurring carcinogens and classified as a group I carcinogen. Since the ingestion of aflatoxin-contaminated food is associated with several liver diseases, the aim of the present study was to evaluate the effect of 2, 20, and 200 ppb of AFB1 on DNA damage in peripheral blood lymphocytes and liver cells in Dunkin-Hartley guinea pigs. The animals were divided into four groups according to the given diet. After the treatment the lymphocytes and liver cells were isolated and DNA damage determined by Comet assay. The levels of DNA damage in lymphocytes were higher animals treated with 200 ppb of AFB1-enriched diet (P = 0.02). In the liver cells there were a relationship between the levels of DNA damage and the consumption of AFB1 in all studied groups. These results suggest that Comet assay performed on lymphocytes is a valuable genotoxic marker for high levels of exposure to AFB1 in guinea pig. Additionally our results indicate that the exposure to this toxin increases significantly and increases the level of DNA damage in liver cells, which is a key step on liver cancer development. We also suggest that the Comet assay is an useful tool for monitoring the genotoxicity of AFB1 in liver. © 2007 Springer Science+Business Media B.V.

Diferenciação hepatocítica de células-tronco mesenquimais da medula óssea humana

Some recent articles have reported that mesenchymal stem cells (MSCs) can be induced to express hepatocyte markers by transplanting them into animal models of liver damage, or by in vitro culture with growth factors and cytokines. In this study, the aim is to evaluate the behavior of MSCs subjected to induction of hepatocyte differentiation. The MSCs were isolated from the bone marrow of 4 normal donors, characterized and subjected to both in vitro and in vivo induction of hepatocyte differentiation. The in vitro induced cells showed morphological changes, acquiring hepatocyte-like features. However, the immunophenotype of these cells was not modified. The induced cells exhibited no increase in albumin, cytokeratin 18 or cytokeratin 19 transcripts, when analyzed by real-time RT-PCR. The expression of albumin, cytokeratin 18 and alpha fetoprotein was also unchanged, according to immunofluorescence tests. In vivo, the MSC demonstrated a potential to migrate to damaged liver tissue in immunodeficient mice. Taken together, the results suggest that bone marrow MSCs are incapable of in vitro differentiation into hepatocytes by the approach used here, but are capable of homing to damaged hepatic tissue in vivo, suggesting a role for them in the repair of the liver. This contribution to tissue repair could be associated with a paracrine effect exerted by these cells.