A novel role for the cyclin-dependent kinase inhibitor p27Kip1 in angiotensin II–stimulated vascular smooth muscle cell hypertrophy

Angiotensin II (Ang II) has been shown to stimulate either hypertrophy or hyperplasia. We postulated that the differential response of vascular smooth muscle cells (VSMCs) to Ang II is mediated by the cyclin-dependent kinase (Cdk) inhibitor p27(Kip1), which is abundant in quiescent cells and drops after serum stimulation. Ang II treatment (100 nM) of quiescent VSMCs led to upregulation of the cell-cycle regulatory proteins cyclin D1, Cdk2, proliferating cell nuclear antigen, and Cdk1. p27(Kip1) levels, however, remained high, and the activation of the G1-phase Cdk2 was inhibited as the cells underwent hypertrophy. Overexpression of p27(Kip1) cDNA inhibited serum-stimulated [(3)H]thymidine incorporation compared with control-transfected cells. This cell-cycle inhibition was associated with cellular hypertrophy, as reflected by an increase in the [(3)H]leucine/[(3)H]thymidine incorporation ratio and by an increase in forward-angle light scatter during flow cytometry at 48 hours after transfection. The role of p27(Kip1) in modulating the hypertrophic response of VSMCs to Ang II was further tested by antisense oligodeoxynucleotide (ODN) inhibition of p27(Kip1) expression. Ang II stimulated an increase in [(3)H]thymidine incorporation and the percentage of S-phase cells in antisense ODN-transfected cells but not in control ODN-transfected cells. We conclude that p27(Kip1) plays a role in mediating VSMC hypertrophy. Ang II stimulation of quiescent cells in which p27(Kip1) levels are high results in hypertrophy but promotes hyperplasia when levels of p27(Kip1) are low, as in the presence of other growth factors.     

Quantitative analysis of enzyme-altered foci in rat hepatocarcinogenesis experiments--I. Single agent regimen

Considerable recent attention has focused on the quantitativeanalysis of enzyme-altered foci in rodent hepatocarcinogenesisexperiments. These foci are believed to represent clones premalignantcells. A method is presented for the quantitative analysis ofthese foci that takes into account both the total number offocal transections observed in each liver crosssection and thesize distribution of these transections. The method, which hasa natural interpretation within the framework of a two-mutationmodel for carcinogenesis, yields estimates of rates of initiationand of growth rates of enzyme-altered foci as functions of doseof the agent under consideration. Definitions of initiationand promotion potencies are proposed. The method is illustratedby application to an experiment in which rats were administeredN-nitroso morpholine at various concentrations in their drinkingwater.     

Autologous Conditioned Serum in the Treatment of Orthopedic Diseases

The common strategies for the treatment of patients with orthopedic diseases do not address the underlying pathogenesis. Several biologically based, local therapies aiming to influence the cytokine imbalance are either in development or in the initial stages of clinical use. A method based on exposure of blood leukocytes to pyrogen-free surfaces (e.g. glass spheres) elicits an accumulation of anti-inflammatory cytokines, including interleukin-1 receptor antagonist, and several growth factors, including insulin-like growth factor-1, platelet-derived growth factor, and transforming growth factor-beta(1), in the liquid blood phase. Based on these observations, a new therapy using cell-free, autologous conditioned serum (ACS) from the incubation of whole blood with glass spheres was developed. The injection of ACS into affected tissue(s) has shown clinical effectiveness and safety in animal models and studies, as well as in human clinical studies, for the treatment of osteoarthritis, lumbar stenosis, disc prolapse, and muscle injuries.     

Decreased caveolin-1 in atheroma: loss of antiproliferative control of vascular smooth muscle cells in atherosclerosis

OBJECTIVE: Proliferation of vascular smooth muscle cells (VSMC) is involved in the pathogenesis of primary atherosclerosis and restenosis after angioplasty. On the background of the antiproliferative activities of caveolin-1, the present study focused on the expression of caveolin-1 in proliferating VSMC of human atheroma. METHODS: VSMC were isolated from wild-type (Wt) and caveolin-1 knockout mice (Cav-/-). Proliferation of Wt-VSMC after supplementation of serum or Cav-/-VSMC after adenoviral overexpression of caveolin-1 was documented by either Western blot analysis of the cyclin-dependent kinase (Cdk) inhibitor p27kip1 and the proliferating cell nuclear antigen (PCNA) or BrdU incorporation. Using immunohistochemistry the proliferation of VSMC derived from atheroma of human carotid vessels as well as the expression of caveolin-1 in these cells were investigated ex vivo. RESULTS: Supplementation of serum to Wt-VSMC resulted in an augmented cell cycle entry and a concomitant decrease of caveolin-1 expression. Inversely, adenoviral overexpression of caveolin-1 in Cav-/-VSMC inhibited cellular proliferation. Corresponding to these in vitro data, the expression of caveolin-1 was significantly decreased in proliferating VSMC of human atheroma. CONCLUSION: The proliferation of VSMC in vitro and in human atheroma is associated with a decrease of caveolin-1 expression. These data suggest that the loss of antiproliferative control by caveolin-1 plays a pivotal role in VSMC proliferation in atherosclerosis.     

Hyperdense basilar artery sign—a reliable sign of basilar artery occlusion

Introduction  

We aimed to investigate the value of the hyperdense basilar artery (HBA) sign and of basilar artery (BA) attenuation measurements as predictors of basilar artery occlusion (BAO) on nonenhanced cranial CT (NECT).     

Integration of health management in schools using the Balanced Scorecard as a strategic management instrument

Aim  

Organizational development is crucial to health promotion in different settings. The Learn to Live Healthy intervention [German: Gesund Leben Lernen (GLL)] is a new school health promotion strategy designed to develop schools into healthy environments for all those who work and study there. GLL focuses on strengthening available health resources and reducing negative and excessive health stresses. The Balanced Scorecard (BSC), a strategic management instrument designed to support change processes, is employed in this BMBF-funded study. This research will assess the suitability of the BSC as a management and evaluation instrument for schools.     

Effect of lipoprotein-X on hepatic cholesterol synthesis.

The effect of different lipoproteins (lipoprotein-X and lipoprotein-B; LP-X and LP-B) on hepatic cholesterol synthesis was studied in vivo in rats. Lipoproteins were continuously infused into rats for 16 hours so that 24 mg cholesterol/100 g body weight were applied. Serum cholesterol level was nearly doubled after the infusion period. Lipoprotein electrophoresis revealed the predominance of the infused lipoprotein in the serum. LP-B infusion caused a reduction of cholesterol synthesis (42% of control values) and reduced the increased cholesterol synthesis of bile fistula rats to values below normal. LP-X did not reduce hepatic cholesterol synthesis significantly nor did it normalize the enhanced synthesis following biliary diversion. However, hepatic free cholesterol concentration increased after LP-X infusion. The effect of LP-X on liver cholesterol synthesis is similar to that of lecithin: cholesterol dispersions. The failure of LP-X to exert a feedback inhibition on cholesterol synthesis may therefore contribute to the mechanism of hypercholesterolemia in obstructive jaundice.