1,721,050 research outputs found
Immunoreactivity for p53 in human head and neck cancer may change after in vitro cisplatin exposure
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Molecular interactions in the metabolism of copper and iron [Interazioni molecolari nel metabolismo del rame e del ferro]
No full textFailure of mitogen-induced cell proliferation to achieve initiation of rat liver carcinogenesis.
No full textExperiments were designed to determine whether mitogen-induced cell proliferation is as effective as regenerative cell proliferation in achieving initiation of liver carcinogenesis. To test this hypothesis male Wistar rats were injected with a single dose of diethylnitrosamine (DENA) or N-methyl-N-nitrosourea (MNU) during the peak of DNA synthesis following the administration of the liver mitogen, lead nitrate, after partial hepatectomy (PH) or a necrogenic dose of CCl4. The initiated hepatocytes were monitored as gamma-glutamyltransferase (GGT)-positive foci using a 2-week selection regimen consisting of 0.03% 2-acetylaminofluorene (2-AAF) coupled with a necrogenic dose of CCl4. The results indicate that unlike compensatory cell proliferation such as that induced by PH or CCl4, mitogen-induced cell proliferation did not result in any initiated hepatocytes despite the fact that in both types of models the extent of liver cell proliferation at the time of the administration of the carcinogen is similar
ROLES OF HEPATOCYTE GROWTH-FACTOR AND TUMOR-NECROSIS-FACTOR-ALPHA ON LIVER-CELL PROLIFERATION IN RATS INDUCED BY LEAD NITRATE
No full textComplete pancreatic heterotopia of gallbladder with hypertrophic duct simulating an adenomyoma
No full textThe gallbladder is an unusual location of pancreatic heterotopia, defined as the presence of pancreatic tissue lacking anatomical and vascular continuity with the main body of the gland. A 28-year-old man presented with anorexia, nausea and pain in the right upper abdomen. On physical examination, the abdomen was tender to palpation and Murphy sign was positive. The patient underwent a cholecystecomy. This case, in our opinion, is very interesting since it permits to consider a controversial issue in the pathology of the gallbladder. The histological appearance of ductal structure in pancreatic heterotopia resembles the histological picture of both Aschoff-Rokitansky (AR) sinuses and adenomyomas. This finding suggests that these lesions are linked by a common histogenetic origin. We suggest that the finding of an adenomyoma in the gallbladder should prompt an extensive sampling of the organ in order to verify the coexistence of pancreatic rests
An electron microscopic study of apoptosis induced by cycloheximide in rat liver
No full textA histological and ultrastructural study, coupled with transmission and scanning electron microscopy of the early changes in the liver following a single administration of cycloheximide (CHX), was carried out in male Wistar rats. At the histological level, apoptosis was already present in the liver 2 h after treatment. By scanning electron microscopy, the following sequential changes were observed: brightness and progressive detachment of hepatocytes from neighbouring cells, formation of surface infolds with multiple blebs and, finally, release of several membrane-bounded apoptotic bodies (ABs) in the extracellular space and into the sinusoidal lumen. Three hours after CHX administration, the apoptotic cycle was completed, as shown by the presence of phagocytosed ABs inside the cytoplasm of intact Liver cells. Light microscopic examination of the liver 6 h after CHX administration showed ABs mainly located in the cytoplasm of intact hepatocytes and inside activated Kupffer cells. By transmission electron microscopy, it was possible to demonstrate that cells undergoing apoptosis were hepatocytes. At 24 h, the livers of treated animals appeared normal, with no evidence of apoptosis
On the variability of MboI repeated sequences and 5S rDNA in Muraena helena and Gymnotorax unicolor (Anguilliformes, Muraenidae)
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