Ultrastructural study of the vascular response in small early gastric cancer

The microvasculature of the stroma of four cases of small early gastric cancer (EGC) was investigated by conventional electron microscopy. Severe damage to small and large fenestrated capillaries was observed around endothelium-adherent, partially degranulated neutrophils. The findings suggest the existence of neutrophil-mediated injury of endothelial cells during the development of inflammatory responses in small EGC. The severely injured microvessels exhibited increase in vasopermeability, microhaemorrhage, and platelet aggregates. Other microvascular changes included endothelial cell and pericyte activation as well as basal lamina replications, indicative of repeated episodes of endothelial injury, necrosis and regeneration. This new capillary growth within the old basal laminas shared morphological features with a peculiar angiogenic process described in man and animals

Prevalence of intranuclear particles in liver pathologies.

An ultrastructural study of the prevalence of electron dense 23-27 nm intranuclear particles was carried out on liver biopsies from patients with NANB chronic active hepatitis (CAH), Delta + CAH, HBsAg + CAH, nonviral liver pathologies and in one healthy volunteer. The particles were classified according to aggregation pattern and were found to be correlated with NANB CAH and Delta + CAH. No particles were observed in nonviral liver pathologies. A close antigenic relationship has been shown between the cytoplasmic alterations observed in NANB and delta hepatitis in chimpanzees. Our data indicate that there is a structural similarity between the intranuclear particles seen in both Delta and NANB hepatitis, thus reinforcing the hypothesis that the NANB and Delta agents are closely related

[Ultrastructural study of the mycelium-yeast transition in Histoplasma capsulatum. I. Changes at 37 degrees C].

Ultrastructural changes observed during the first 24 hours of mycelium to yeast transition in the dimorphic fungus Histoplasma capsulatum are reported. During this period the plasma membrane becomes undulated and the cell wall loses its characteristic fibrous outer layer. At 8 h the ordered lamellar structure of the mitochondria is no longer apparent. 24 h after the temperature shift 70% of the cells are lysed. The remaining cells contain many cytoplasmic membrane structures; mitochondria are rarely observed. These morphological changes are probably correlated with the physiological events characteristic of mycelial to yeast transition

Prevalence of hepatitis C virus genotypes in southern Italy

HCV is ubiquitous. In 50% of all cases it causes chronic hepatitis that often evolves into liver cirrhosis and hepatocellular carcinoma. Recently HCV has been classified in 5 genotypes by Okamoto. The purpose of this study is to evaluate the prevalence of 5 genotypes in Campania, a region of southern Italy, where the prevalence of anti-HCV antibodies ranges from 0.87 to 4%, and to evaluate the correlation between the HCV genotypes and the severity of histological damage. One-hundred-and-thirty-five anti-HCV positive patients were enrolled and tested by PCR to identify HCV-RNA. One-hundred-and-twenty-four patients resulted HCV-RNA positive. Genotyping was performed as described by Okamoto et al. with minor modifications of the specific primer to type III proposed by Silini et al. Eight patients were negative for all genotypes. Eight patients were positive for type I(1a), 61 for type II(1b), 39 for type III(2a), 11 for type IV(2b) and 1 for type V(3a). In 4 cases two different genotypes were present in the same sample [II(1b)-IV(2b), III(2a)-II(1b) twice, III(2a)-IV(2b)]. Histological evaluation of liver damage showed: CPH (22 cases), minimal CAH (56), severe CAH (31) and liver cirrhosis (15). There was no statistically significant correlation between the 5 genotypes and the severity of histological damage. Data on the prevalence of genotype II(1b) in Italy are similar to those reported for other European countries. The prevalence of genotypes in southern Italy is similar to that reported in the population of northern Italy