An ultrasound and histomorphological analysis of experimental liver cirrhosis in rats

We investigated whether liver injury by dual exposure to ethanol and carbon tetrachloride (EtOH + CCl4) for 15 weeks would persist after hepatotoxic agents were removed (EtOH + CCl4/8wR). After 15 weeks of hepatic injury with ethanol (5.5 percent, m/v) and carbon tetrachloride (0.05, mL/kg, ip), 5 of 11 female Wistar rats were sacrificed. The other 6 rats were maintained for an additional 8 weeks without hepatotoxic agents. Ultrasonography showed increased liver echogenicity and dilation of portal vein caliber in both groups (EtOH + CCl4: 0.22 ± 0.01 cm, P < 0.001; EtOH + CCl4/8wR: 0.21 ± 0.02 cm, P < 0.01) vs control (0.16 ± 0.02 cm). Histopathology showed regenerative nodules in both experimental groups. Histomorphometry revealed increased fibrosis content in both groups (EtOH + CCl4: 12.6 ± 2.64 percent, P < 0.001; EtOH + CCl4/8wR: 10.4 ± 1.36 percent, P < 0.05) vs control (2.2 ± 1.21 percent). Collagen types I and III were increased in groups EtOH + CCl4 (collagen I: 2.5 ± 1.3 percent, P < 0.01; collagen III: 1.3 ± 0.2 percent, P < 0.05) and EtOH + CCl4/8wR (collagen I: 1.8 ± 0.06 percent, P < 0.05; collagen III: 1.5 ± 0.8 percent, P < 0.01) vs control (collagen I: 0.38 ± 0.11 percent; collagen III: 0.25 ± 0.06 percent). Tissue transglutaminase increased in both groups (EtOH + CCl4: 66.4 ± 8 percent, P < 0.01; EtOH + CCl4/8wR: 58.8 ± 21 percent, P < 0.01) vs control (7.9 ± 0.8 percent). Cirrhosis caused by the association of CCl4-EtOH remained for at least 8 weeks after removal of these hepatotoxic agents. Ultrasound images can be a useful tool to evaluate advanced hepatic alterations.

Multicellular spheroids of bone marrow stromal cells: a three-dimensional in vitro culture system for the study of hematopoietic cell migration

Cell fate decisions are governed by a complex interplay between cell-autonomous signals and stimuli from the surrounding tissue. In vivo cells are connected to their neighbors and to the extracellular matrix forming a complex three-dimensional (3-D) microenvironment that is not reproduced in conventional in vitro systems. A large body of evidence indicates that mechanical tension applied to the cytoskeleton controls cell proliferation, differentiation and migration, suggesting that 3-D in vitro culture systems that mimic the in vivo situation would reveal biological subtleties. In hematopoietic tissues, the microenvironment plays a crucial role in stem and progenitor cell survival, differentiation, proliferation, and migration. In adults, hematopoiesis takes place inside the bone marrow cavity where hematopoietic cells are intimately associated with a specialized three 3-D scaffold of stromal cell surfaces and extracellular matrix that comprise specific niches. The relationship between hematopoietic cells and their niches is highly dynamic. Under steady-state conditions, hematopoietic cells migrate within the marrow cavity and circulate in the bloodstream. The mechanisms underlying hematopoietic stem/progenitor cell homing and mobilization have been studied in animal models, since conventional two-dimensional (2-D) bone marrow cell cultures do not reproduce the complex 3-D environment. In this review, we will highlight some of the mechanisms controlling hematopoietic cell migration and 3-D culture systems.

Detection of hepatitis C virus RNA by in situ hybridization in paraformaldehyde fixed biopsies

Fourteen hepatitis C virus (HCV) chronically infected patients were submitted to routine liver biopsy for histological evaluation. Liver samples were assayed to HCV-RNA by in situ hybridization, using digoxigenin labeled probe. HCV genotypes were found to be predominantly type 1 (71.4 percent), followed by genotype 3 (21.4 percent), and genotype 2 (7.2 percent). Alanine-aminotransferase levels were raised in 10 patients. The histopathological scores were minimal (21.4 percent), mild (57.2 percent), and moderate (21.4 percent). Viral RNA was detected in liver cells from nine patients (64.3 percent). ISH method provides localization and poor confirmation of HCV RNA in the liver tissue of HCV chronic patients.

Experimental infection of newborn mice with murine EDIM rotavirus

All four-day old Swiss mice whose dams were seronegative to rotavirus developed diarrhea 72 h after oral infection with EDIM rotavirus (HP strain). Electron microscopy of infected small intestine showed rotavirus particles of different sizes and morphology in the intestinal absorptive cells. In these cells rotavirus particles of 30 to 60 nm representing the various steps of virus maturation were visualized in viroplasm near the rough endoplasmic reticulum (RER). Mature rotavirus particles of 70 nm approximately were observed inside the RER of the intestinal absorptive cells. In the lamina propria rotavirus particles of approximately 30 nm and tubules were observed in phagosome-like structures of subepithelial phagocytes and were probably destroyed by lysosomal enzymes. The absence of signs of viral replication in phagocytes of lamina propria suggests that this may be the mechanism for viral antigen presentation to the host immunological system and may be one of the reasons for the fact that rotavirus infection is limited to the intestine

Estudo ultra-estrutural das lesoes celulares induzidas pelo virus vacinal do sarampo "in vitro". / Ultrastructural study of cell damages induced by vaccinal measles virus in vitro

Nesta pesquisa estudaram-se as alteracoes ultra-estruturais de celulas Vero, infectadas pelo virus vacinal do sarampo, durante um ciclo replicativo. As lesoes foram acompanhadas a partir de 8 horas ate o 10o. dia. Destacamos os aspectos degenerativos que foram observados desde o inicio da infeccao, representados por dilatacao de organelas citoplasmaticas. Os sincicios formados mostraram pequena replicacao viral e nao completavam a formacao de brotamentos. Os nucleos continham nucleolos alargados e eletrodensos e a cromatina se apresentava eletrodensa ou formando grumos aderidos a membrana nuclear. Nao foram observadas particulas virais no nucleo