No abstract available.

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No abstract available.

The aim of this study was to clarify the role of Kupffer cells in the mechanism of endotoxin-induced liver injury. The study on fine structure of Kupffer cells was performed after the injection of endotoxin. The endotoxin(Escherichia soli lipopolysaccharide 026: B6, 1.5mg/100 g of body weight) was intraperitoneally injected in Sprague-Dewley rats. Animals were sacrificed at 1/4, 1/2, 1, 2, 4, 8, 16, 24, 72 and 120 hours after the injection of endotoxin. Livers were extirpated and processed to be examined by light and electron microscopy. The results obtained were summerized as follows: Early changes observed in liver after endotoxin injection included the increased number and hypertrophy of Kupffer cells, infiltration of neutrophils and presence of fibrin thrombi within the sinusoids. The coritinuous increase of the Kupffer cells in number with hypertrophy, congestion and infiltration of inflammatory cells within the sinusoids were observed. Hepatocytes showed* fatty change and occasional necrosis. At 72 hours the congestion decreased. At 120 hours the number of Kupffer cells was increased, but the morphology of Kupffer cells became similar to that of the control group. The numbers and sizes of primary and secondary lysosomes and amount of euchromatin of Kupffer cells increased. Swellings and increase in number of mitochondria, Golgi complex, smooth endoplasmic reticulum, rough endoplasmic reticulum were evident. Microthrombi were present within the sinusoids. The swelling of rough endoplasmic reticulum and mitochondria, decrease of glycogen particles, fatty change, hypoxic vacuoles, pyknotic nuclei and occasional necrosis were observed in hepatocytes. At 72 hours the number of secondary lysosomes in Kupffer cells decreased. At 120 hours the morphology of Kupffer cells became similar to that of the control group. According to these results, it was postulated that the endotoxin was initially taken up by pinocytosis into Kupffer cells and degraded in secondary lysosomes of activated Kupffer cells. Kupffer cells may play an important role in the defense mechanism of liver during endotoxemia. The dysfunction of Kupffer cells and ischemia by sinusoidal microthrombi may cause liver injury.
Animals ; Endoplasmic Reticulum, Rough ; Endoplasmic Reticulum, Smooth ; Endotoxemia ; Estrogens, Conjugated (USP) ; Euchromatin ; Fibrin ; Glycogen ; Golgi Apparatus ; Hepatocytes ; Hypertrophy ; Ischemia ; Kinetics* ; Kupffer Cells* ; Liver ; Lysosomes ; Microscopy, Electron ; Mitochondria ; Necrosis ; Neutrophils ; Pinocytosis ; Rats* ; Vacuoles

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No abstract available.

To investigate the immunohistochemical expression of mutated p53 protein and bcl-2 protein in the cutaneous melanocytic lesion, 15 cases of compound nevus, 10 cases of congenital melanocytic nevus, 15 cases of primary malignant melanoma(4 cases less than 1.5 mm thick and 11 cases more than 1.5 mm thick), and 10 cases of metastatic malignant melanoma(7 cases in lymph node and 3 cases in soft tissue) were examined. All cases of compound nevi and of congenital melanocytic nevi showed no immunoreactivity for p53 protein. p53 protein overexpression was observed in 75%(3/4) wth primary malignant melanoma less than 1.5 mm thick, 81%(9/11) with primary malignant melanoma more than 1.5 mm thick, and 100%(10/10) with metastatic malignant melanoma. The difference in p53 protein overexpression was statistically significant between benign nevi and malignant melanoma(p<0.01). Bcl-2 protein expression was observed in 73%(11/15) with compound nevus, 70%(7/10) with congenital melanocytic nevus, 75% (3/4) in primary malignant melanoma less than 1.5 mm thick, 54%(6/11) with primary malignant melanoma more than 1.5 mm thick, and 40%(4/10) with metastatic malignant melanoma. These findings suggested that mutation of p53 gene may be an important mechanism in the development of malignant melanoma. Although bcl-2 protein was expressed in cutaneous melanocytic lesion, no correlation was found between p53 protein and bcl-2 protein expression in malignant melanoma.
Genes, p53 ; Lymph Nodes ; Melanoma ; Nevus ; Nevus, Pigmented ; Skin*