Suppression of neointimal thickening by a newly developed HMG-CoA reductase inhibitor,BAYw6228, and its inhibitory effect on vascular smooth muscle cell growth

1. The aim of this study was to determine whether BAYw6228 (BAYw), a newly developed 3-hydroxy-3-methylglutaryl-CoA (HMG-CoA) reductase inhibitor, could suppress an atherogenic process such as intimal thickening by a mechanism other than lowering the level of serum cholesterol.
2. First, we evaluated the in vitro effect of BAYw on the proliferation of vascular smooth muscle cells (SMC) from various species: Sprague-Dawley (SD) rats, New Zealand (NZ) white rabbits, intimal cells from Watanabe hereditary hyperlipidemic (WHHL) rabbit and SMC from the new-born human aorta. The increasing rate of total protein content of these cells was inhibited by the addition of BAYw in a dose-dependent fashion. In the presence of 2% foetal calf serum (FCS), the value of IC₅₀ was 1.0 μM in SD rats. 2.1 μM in NZ white rabbits, and 0.3 μM in WHHL rabbits. With human SMC, the value was 0.02 μM in the presence of 10% FCS and 0.2 μM with a mixture of growth factors.
3. Based on these above in vitro findings, we next examined the in vivo effect of the agent to determine whether it could suppress rabbit intimal thickening induced by balloon catheterization. A balloon catheter was inserted from a peripheral branch of the left external carotid artery to the aorta to denude the endothelium of the left common carotid artery in Japanese white rabbits. After 12 days they were divided into control and BAYw groups. The former were subcutaneously injected with saline and the latter with BAYw 1 mg kg⁻¹ day⁻¹. Two days after the beginning of treatment, a second balloon injury was performed to the previously injured left common carotid artery in both groups. After another two weeks, the left common carotid artery was removed and variously stained. Although the total serum cholesterol in the BAYw group was significantly lower than in the control (P<0.05), the difference was not enough to affect intimal thickening. In addition, the BAYw group had a smaller intima/media ratio than the control group, decreasing to 45% of control (P<0.05). By anti-α smooth muscle actin antibody staining, these intimal thickening areas were entirely occupied by SMCs, and their amount was attenuated by BAYw. By anti-rabbit macrophage antibody (RAM 11) staining, the number of positive cells in the intimal thickening was markedly decreased in the BAYw group compared to control (P<0.01).
4. These results indicate that BAYw has an inhibitory effect on intimal thickening by attenuating intimal SMC proliferation and infiltration of macrophages, suggesting that BAYw could be effective in the prevention of the progression of atherosclerotic plaque-like restenosis after angioplasty.

     

Analysis of Cdc2 and Cyclin D1 expression in breast cancer by immunoblotting

Cyclins and cyclin-dependent kinases may reflect the status of cell proliferation in cancer tissues. The authors sought to determine whether cdc2 and cyclin D1 are expressed in breast cancer and are useful as prognostic factors. Accumulation of cdc2 and cyclin D1 proteins was examined in 88 cases of breast cancer using immunoblotting techniques and correlations with clinicopathological factors and prognoses were investigated. Cdc2 and cyclin D1 proteins were observed in 27.3% and 75.0% of breast cancers studied, respectively. The incidence of lymph node metastasis was significantly high in cdc2/cyclin D1-double positive group and low in double negative group. On the other hand, the incidence of estrogen receptor (ER) negative cases was significantly higher in the cdc2-positive/cyclin D1-negative group. Relapse-free survival times of cdc2-positive cases were significantly shorter than those of cdc2-negative cases. The relapse-free survival times of cyclin D1-positive cases also tended to be poorer than those of cyclin D1-negative cases. Multivariate analyses revealed cdc2 as the second most significant of the prognostic variables, following lymph node status. The three-year relapse-free survival rate of cdc2/cyclin D1-double positive cases was 58.9%, whereas that of cdc2/cyclin D1-double negative cases was 100%. Cdc2 and cyclin D1 represent the status of cell proliferation in breast cancer, and may be useful in breast cancer assessment.     

Overtime, psychosocial working conditions, and occurrence of non- insulin dependent diabetes mellitus in Japanese men

OBJECTIVES: To ascertain the effects of overtime and psychosocial job conditions on the occurrence of non-insulin dependent diabetes mellitus (NIDDM) in Japan. DESIGN: An eight year prospective cohort study. SETTING: An electrical company in Japan. PARTICIPANTS: In 1984, a mailed questionnaire was sent to industrial workers of an electrical company in Japan. After excluding those who had a history of diabetes mellitus or other chronic diseases, 2597 male respondents were prospectively followed up for the succeeding eight years. Data from 2194 (84%) who were completely followed up were analysed. The occurrence of NIDDM during the follow up period was assessed according to the WHO criteria on the basis of an annual screening programme. MAIN RESULTS: The age adjusted incidence of NIDDM was significantly higher in those who worked overtime more than 50 hours per month than in those who worked 25 hours or less per month (p < 0.05). It was significantly higher in those who worked with new technology at baseline than in those who did not (p < 0.05). Cox's proportional hazard model indicated that those who worked overtime more than 50 hours per month had 3.7 times higher risk of NIDDM after controlling for known risk factors (p < 0.01) and those who worked with new technology had 2.4 times higher risk of NIDDM (p < 0.05). CONCLUSIONS: It is suggested that longer overtime and use of new technology are risk factors of NIDDM in Japanese men.     

Peripheral choriovitreal neovascularization in proliferative diabetic retinopathy: histopathologic and ultrastructural study

We describe the histopathologic and ultrastructural evidence of choriovitreal neovascularization in the peripheral fundus of a non-vitrectomized eye with proliferative diabetic retinopathy (PDR). One eye with PDR was surgically enucleated because of neovascular glaucoma and studied with light and electron microscopy. The eye had neovascular membranes at the ora serrata of the peripheral fundus. The newly formed vessels originated from the choroid, passed through Bruch's membrane and the retina, and extended into the vitreous. These vessels had either developing or mature characteristics. The endothelial cells of the developing vessels contained a bulky cytoplasm with many intracytoplasmic filaments, ribosomes and rough endoplasmic reticulum. Budding endothelial cells were frequently found in the developing vessels. The endothelial cells of the mature vessels had attenuated cytoplasm and fenestrations with diaphragms. These observations suggest that choriovitreal neovascularization in the peripheral fundus is one of the features of PDR.     

E5531, a synthetic non-toxic lipid A derivative blocks the immunobiological activities of lipopolysaccharide.

1. The major pathological responses to Gram-negative bacterial sepsis are triggered by endotoxin or lipopolysaccharide. As endotoxin is shed from the bacterial outer membrane, it induces immunological responses that lead to release of a variety of cytokines and other cellular mediators. As part of a program aimed at developing a therapeutic agent for septic shock, we have developed E5531, a novel synthetic lipopolysaccharide antagonist. 2. As measured by release by tumour necrosis factor-alpha, human monocytes or whole blood can be activated by lipopolysaccharide, lipid A, and lipoteichoic acid (from Gram-positive bacteria). E5531 potently antagonizes activation by all these agents while itself being devoid of agonistic activity. 3. The inhibitory activity of E5531 was dependent on time of addition. When 10 nM E5531 was added simultaneously with lipopolysaccharide or 1 - 3 h before addition of lipopolysaccharide, production of tumour necrosis factor-alpha was inhibited by more than 98%. The addition of E5531 1 h after lipopolysaccharide reduced the efficacy of E5531 by 47%. 4. Antagonistic activity of E5531 was specific for lipopolysaccharide as it was ineffective at inhibiting interferon-gamma mediated NO release of RAW 264.7 cells, phorbor 12-myristate 13-acetate stimulated superoxide anion production in human neutrophils, concanavalin A stimulated mitogenic activity in murine thymocytes and tumor necrosis factor-alpha induced E-selectin expression in human umbilical vein endothelial cells. 5. E5531 as well as MY4, an anti-CD14 antibody, inhibited radiolabelled lipopolysaccharide binding in human monocytes. 6. These results support our contention that E5531 is a potent antagonist of lipopolysaccharide-induced release of tumour necrosis factor-alpha and other cellular mediators and may be an effective therapeutic agent for human septic shock due to Gram-negative bacteria.     

The effect of motivation on preschool children's sharing judgment and behavior]

The purpose of this study was to examine the effect of motivation on preschool children's sharing judgment and behavior. In Experiment 1, 45 4-year-olds and 41 5-year-olds were asked whether they wanted to share seals in a fictional situation, and were observed whether they shared their seals in an actual situation. The main results indicated that the number of children who shared seals in the latter situation was smaller than those who judged to share seals in the former one. Especially there was a great difference regarding this point in 4-year-olds children. "Empathic orientation" motivated preschool children's sharing behavior, while "self-focused orientation" did not. In Experiment 2, 52 4-year-olds and 60 5-year-olds were divided into two empathic levels (middle, high) and two motivational cost levels (low, high) to examine the effects of "empathic orientation" and "self-focused orientation." The main results indicated that high motivational cost restrained children from sharing in an actual situation.     

Chronic inhibitory effect of insulin on plasma lipid concentrations in rats with transplanted pancreas

BACKGROUND: Hyperinsulinemia, which is usually related to insulin resistance, is considered to be an important risk factor for coronary artery disease. Our study examines the influence of portal delivery of endogenous insulin after pancreas transplantation on plasma lipid metabolism, as compared with systemic delivery of insulin. METHOD: Pancreas was transplanted heterotopically in normal rats by anastomosis of the donor portal vein to the recipient portal vein (PPTx) or inferior vena cava (CPTx) as an in vivo model of endogenous hyperinsulinemia. RESULTS: The mean value of plasma insulin concentration of CPTx and PPTx rats was 149 and 165% that of control rats, whereas the plasma glucose concentration of CPTx and PPTx rats did not differ significantly from that of control rats. Plasma triglyceride (TG) concentrations were significantly lower in both PPTx and CPTx rats than control rats. During the intravenous glucose tolerance test, the area under the insulin concentration curves of CPTx and PPTx rats was 204 and 215% that of control rats, and they were correlated negatively with plasma TG concentrations. Plasma cholesterol and TG concentrations were significantly lower in PPTx rats than in control and CPTx rats. CONCLUSIONS: Chronic hyperinsulinemia has a dose-dependent inhibitory effect on the regulation of plasma TG concentrations in rats with a transplanted pancreas. Significant lower lipid levels in PPTx rats than in CPTx rats suggest that portal delivery of insulin from the transplanted pancreas is relatively preventive for the atherosclerotic process as compared with systemic delivery of insulin.