Proliferation Of Villi Research Articles

Sepsis reveals compartment-specific responses in intestinal proliferation and apoptosis in transgenic mice whose enterocytes re-enter the cell cycle.

Cell production and death are tightly regulated in the rapidly renewing gut epithelium, with proliferation confined to crypts and apoptosis occurring in villi and crypts. This study sought to determine how stress alters these compartmentalized processes. Wild-type mice made septic via cecal ligation and puncture had decreased crypt proliferation and increased crypt and villus apoptosis. Fabpi-TAg mice expressing large T-antigen solely in villi had ectopic enterocyte proliferation with increased villus apoptosis in unmanipulated animals. Septic fabpi-TAg mice had an unexpected increase in villus proliferation compared with unmanipulated littermates, whereas crypt proliferation was decreased. Cell cycle regulators cyclin D1 and cyclin D2 were decreased in jejunal tissue in septic transgenic mice. In contrast, villus and crypt apoptosis were increased in septic fabpi-TAg mice. To examine the relationship between apoptosis and proliferation in a compartment-specific manner, fabpi-TAg mice were crossed with fabpl-Bcl-2 mice, resulting in expression of both genes in the villus but Bcl-2 alone in the crypt. Septic bi-transgenic animals had decreased crypt apoptosis but had a paradoxical increase in villus apoptosis compared with septic fabpi-TAg mice, associated with decreased proliferation in both compartments. Thus, sepsis unmasks compartment-specific proliferative and apoptotic regulation that is not present under homeostatic conditions.-Lyons, J. D., Klingensmith, N. J., Otani, S., Mittal, R., Liang, Z., Ford, M. L., Coopersmith, C. M. Sepsis reveals compartment-specific responses in intestinal proliferation and apoptosis in transgenic mice whose enterocytes re-enter the cell cycle.

Osteonecrosis of the femoral head associated with pigmented villonodular synovitis.

A 23-year-old Japanese woman with no history of corticosteroid intake or alcohol abuse presented with a 10-month history of left hip pain without any antecedent trauma. An anteroposterior radiograph performed 10months after the onset of pain showed slight joint space narrowing and bone erosions surrounded by sclerotic lesions in both the acetabular roof and femoral neck. Magnetic resonance images of the left hip showed a feature of osteonecrosis of the femoral head and a mass with villus proliferation extending from the posterior intertrochanteric area to the anteromedial aspect of the femoral neck. In addition, the left quadratus femoris muscle, which is generally located just above the nutrient vessels of the femoral head, was not detected. Based on these findings, the patient was diagnosed with osteonecrosis of the femoral head caused by impairment of the nutrient vessels from invasion of the pigmented villonodular synovitis. She underwent radical synovectomy of the left hip 16months after the onset of pain, and her hip pain improved after the surgery.

P198: Intestinal adaptation following massive small bowel resection: Is there a role for the hedgehog signaling pathway?

Background: Hedgehog signaling plays a key role in small intestinal morphogenesis. Studies on knockout mice indicate important but disparate functions for Sonic hedgehog (Shh) and Indian hedgehog (Ihh) in the inhibition and stimulation of villus proliferation respectively. Proliferation and differentiation are essential factors in the process of intestinal adaptation. We therefore hypothesized that hedgehog signaling may play a role in the small bowel adaptive response, and to test this, examined expression of the hedgehog proteins following massive small bowel resection in rats.

Morphologic Changes in the Lungs of Cats Experimentally Infected With Dirofilaria immitis

The morphologic response of the pulmonary arteries and lungs in cats was studied after a five month heartworm infection produced by transplantation of four adult heartworms/cat. One group of seven heartworm infected cats was not treated, another group of seven cats was treated with 97.5 mg of aspirin given twice a week, and the third group of six cats was given aspirin at a sufficient dosage to block in vitro platelet aggregation throughout the study. A fourth group of eight noninfected cats served as controls. Five months after heartworm infection, the cats were euthanized and the lungs perfusion fixed for light microscopy and scanning electron microscopy of the pulmonary arterial surfaces.All cats in the three heartworm‐infected groups had live heartworms and the typical pulmonary arterial changes of heartworm disease at necropsy. The arterial surfaces, as viewed with scanning electron microscopy, had villus proliferations that were more numerous and exuberant than similar infections in dogs. Mean percentage of arterial surface involvement with villus proliferation of the nontreated heartworm infected cats was 67.3%; the aspirin treated cats, 73.8%; and the adjusted aspirin treated cats, 75.9%. The villi were myointimal proliferations in the small and medium‐sized arteries. The more elastic arteries had a predominance of fibromuscular proliferation. All heartworm infected cats had arterial muscular hypertrophy of the small arteries, in contrast to only three of eight of the nonheartworm infected cats. The caudal lobar arteries were frequently obstructed with either villus proliferation, thrombi, and/or dead heartworms. The muscular arteries had branches with marked dilation, a condition associated with pulmonary hypertension in man. However, only three cats, one in each group, had pulmonary hypertension. The adjusted aspirin group had less arteriosclerosis and thrombosis than the other two heartworm‐infected groups. There were no statistical differences between the heartworm groups with respect to arterial muscular hypertrophy, myointimal proliferation with and without eosinophilia, vein‐like dilations of the muscular arterial branches, and percentage of arterial surface with villus proliferation.Aspirin, when given at platelet inhibiting doses, reduced only a portion of the pulmonary response to heartworms in these cats. It was presumed that the inflammatory response to heartworms in the cat is so severe that trophic factors other than those released by platelets can also produce arterial disease. Based upon this study, aspirin is not recommended for heartworm disease in the cat.

Histological alterations in liver and intestine of teleost Sarotherodon mossambicus in response to mercury toxicity

Effects of lethal (1.5 ppm) and sublethal (0.1 ppm) concentrations of HgCl 2 on liver and intestine tissues of Sarotherodon mossambicus were studied by routine histological techniques. Engorged blood sinusoid, vacuolation, rupture, granular degeneration of hepatocytes, edema, focal necrosis, and proliferation of fibroblasts were the alterations observed in liver. Rupture of the tips of the villi, proliferation of villi, increase in goblet cell population, and focal necrosis of villi were the characteristic changes in intestine.