Impact of Low Bone Mineral Content Index on Cardiovascular Outcomes in Patients With Coronary Artery Disease Undergoing Percutaneous Coronary Intervention.

The prognostic value of bone mineral content (BMC) for the clinical outcomes of patients with coronary artery disease (CAD) remains unknown. The present study evaluated the association between BMC index (BMCI) and cardiovascular events between January 2020 to June 2021, in consecutive patients (n = 257) with CAD undergoing percutaneous coronary intervention (PCI) at the Nagano Municipal Hospital. BMCI was measured using bioelectrical impedance analysis and calculated as the BMC divided by height squared. Patients were classified as low (<0.918) or high BMCI (≥0.918) groups according to the receiver operating characteristics curve analysis for the primary endpoint, major adverse cardiovascular events (MACE), including cardiovascular death, spontaneous myocardial infarction, stroke, and any revascularization. During a median follow-up of 744 days, the low BMCI group (n = 152) had an increased risk of MACE compared with the high group (n = 105) (19.7 vs 6.7%, P = .004). A low BMCI was significantly associated with MACE in the multivariable Cox and the Inverse Probability of Treatment Weighting analyses (hazard ratio: 3.16, 95% confidence interval: 1.15-8.67, P = .025). In conclusion, among patients with CAD undergoing PCI, BMCI was a predictor for cardiovascular events. Further research is required to determine whether medical interventions for BMC can improve patient prognosis.

Hepatocyte proliferation activity in untreated rats, measured by immunohistochemical detection of Ki-67: The effect of age on the repeated-dose liver micronucleus assay.

The repeated-dose liver micronucleus (RDLMN) assay is a widely accepted method for detecting genotoxic substances. We investigated the effect of animal age on this assay. Proliferation activity in the liver tissue of untreated rats at age = 3.5, 6, 8, 10, or 12 weeks was measured via immunohistochemical expression of Ki-67 protein. The percentage of Ki-67-positive hepatocytes decreased markedly with age, reaching very low levels after 10 weeks, indicating decline with age of proliferative capacities in the liver. We calculated the area under the curve (AUC) of the approximate curve generated from the percentage of Ki-67-positive cells, to estimate the hepatocyte proliferation activity over the dosing period in the two regimens of the 4-week RDLMN assay: dosing initiated at age = 6 or 8 weeks. Hepatocyte proliferation activity of the former regimen was approximately double that of the latter. We also calculated the AUC for the juvenile-rat method, in which rats are treated for two days at age = 3.5 weeks. The AUC calculated for that method was approximately half of that for the 4-week repeated-dosing regimen initiated at 6 weeks of age. These findings suggest that the 4-week RDLMN assay with dosing initiated at age = 6 weeks could be approximately twice as sensitive as the other two methods.

A mammary fibroadenoma with terminal end buds-like structures in a 7-week-old male SD rat.

We report a case of mammary fibroadenoma in a 7-week-old male SD rat. This case showed rapid growth within one week from the time when the nodule was detected. Histologically, the nodule was a well-circumscribed subcutaneous mass. The tumor consisted of an epithelial component with island-like proliferation (cribriform to tubular patterns) and an abundant mesenchymal component. Alpha-SMA-positive cells were arranged at the periphery of the epithelial component and showed cribriform and tubular patterns. Discontinuous basement membranes and high cell proliferative activities were observed in the cribriform area. These features resembled those of normal terminal end buds (TEBs). Since the mesenchymal component had abundant fine fibers and a mucinous matrix, its stroma was regarded as neoplastic growth of fibroblasts; thus, this tumor was diagnosed as a fibroadenoma. This case is an extremely rare fibroadenoma in that it occurred in a young male SD rat and was composed of an epithelial component showing multifocal proliferation of TEB-like structures and a mucinous mesenchymal component consisting of fibroblasts with fine collagen fibers.