Mitotic Index Levels Research Articles

Impact of Age on Survival after Partial Portal Vein Arterialization for the Treatment of Post-Hepatectomy Liver Failure in a Rat Model

Introduction: Post-operative liver failure (PLF) occurs in approximately 10% of patients undergoing major hepatectomy. Partial portal vein arterialization (PPVA) enhances the regenerative capacity of the resected liver. The aim of this study was to investigate the impact of age on survival after PPVA for the treatment of post-operative liver failure in a rat model. Materials and Methods: 24 rats underwent extended liver resection, that leaded to PLF. 12 rats were divided in 2 groups treated with PPVA: group 1a-young rats (n=6, age 2 months) and group 2a-old rats (n=6, age 30 months). Two control groups of rats of the same age were not treated with PPVA: group 1b-young and group 2b-old. Results: on postoperative day 7, no significant differences were observed among all groups in terms of ALT levels, prothrombin activity and serum creatinine. As for the liver regeneration markers, the level of mitotic index was greater in the groups treated with PPVA compared to the control groups (without significant differences between young and old groups). The 75% (9/12) of the rats treated with PPVA survived up to 7 days, with no significant differences between young (5/6) and elderly rats 66.7% (4/6). Conclusion: PPVA treatment had the same beneficial effect both in young and old rats.

Mitotic index and Alzheimer's disease.

Alzheimer's disease (AD), a progressive neurodegenerative disorder, is diagnosed definitively by increased numbers of beta-amyloid plaques and neurofibrillary tangles in brain biopsy or autopsy specimens. There are no simple straightforward laboratory tests currently available for clinical diagnosis. We have found consistent reduction in mitotic index levels in skin fibroblast cultures from AD individuals compared with age- and sex-matched controls. These differences were enhanced by overnight exposure to colcemid (p = 0.04). Results suggest that mitotic index in skin fibroblasts cultures should be further investigated as a potential diagnostic indicator for AD.

In vivo and in vitro induction of sister-chromatid exchanges by nordihydroguaiaretic acid

Nordihydroguaiaretic acid (NDGA) is a phenolic lignan previously used as an antioxidant in commercial products, and with a number of properties potentially useful to man. As its genotoxic capacity has been poorly evaluated, in this investigation we determined its effect on the production of sister-chromatid exchanges (SCEs), and on the level of mitotic index (MI) in cultured human lymphocytes and in mouse bone marrow cells in vivo. The proliferative index (PI), and the average generation time (AGT) were also determined for human lymphocytes and in mouse bone marrow cells respectively. The in vitro study was made in two donors using NDGA doses of 1.1, 3.6, 6.7, 13.5, and 27.0 μM; and for the in vivo study the tested doses were 8.8, 17.6, 35.3, and 70.7 mg/kg of body weight. The results concerning SCE induction in human lymphocytes showed a dose-dependent response with a maximum mean increase of 5.52 SCE in relation to the control level, and with respect to MI and PI a decrement of more than 50% and a cell cycle delay was detected only with the high dose. In the study with bone marrow cells, a statistically significant difference was determined with the high two doses (an increase of 1.06 SCEs with 70.7 mg/kg in relation to the control level). The MI decreased only with the high dose and no modification was observed with respect to AGT. In conclusion, in both used models the study demonstrated that NDGA produced genotoxic and cytotoxic effects.

Interaction of external agents with the circadian mitotic rhythm in the epithelium of the hamster cheek pouch∗

Abstract Use of intermittent white noise (60 and 70 dB) as an additional synchronizer in the light period (12 h) gave a rise in the level of mitotic index and moved the maximal values 1 to 3 h forward in time. The effects increased with the sound level. Unskilled handling of the animals in itself could produce a significant decrease in mitotic index. Independent of the various external conditions injection of ‘HTdR (1 /μCi/g body weight; 6 Ci/m mol) increased the mitotic index during the first hours after injection.