The effect of calcium ion concentration on osteoblast viability, proliferation and differentiation in monolayer and 3D culture

Our research group aims to develop an osteochondral composite using type II collagen gel with hydroxyapatite (HAp) deposited on one side. Soaking gels in Ca2+ and phosphate solution is indispensable to HAp deposition, so relationships between cell behavior and Ca2+ concentration were examined in two- and three-dimensional cultures. The present results indicate that 2-4 mM Ca2+ is suitable for proliferation and survival of osteoblasts, whereas slightly higher concentrations (6-8 mM) favor osteoblast differentiation and matrix mineralization in both 2- and 3-dimensional cultures. Higher concentrations (>10 mM) are cytotoxic. Purely from the perspective of calcium deposition, higher concentrations lead to increased accumulation of Ca2+. Culturing cells in phosphate-containing gel in media with Ca2+ also leads to time-dependent formation of HAp in the gel. Considering the viability of embedded cells, culturing scaffolds in media with Ca2+ concentrations around 5mM is useful for both HAp deposition and osteoblast behavior.     

HLA-DR antigen expression and lymphocyte subsets in transitional cell carcinoma of the urinary bladder. An immunohistological study on frozen sections

Lymphocyte subpopulations (B cells, CD4, CD8), interleukin-20 receptors (IL-2), monocytes/macrophages (Leu M₅), and HLA-DR antigen expression were studied immunohistochemically on frozen sections from 38 bladder cancer specimens. T cells predominated over B cells in all tumours. CD4-positive lymphocytes predominated over CD8 in the stroma (CD4/CD8: 1·35/1), while in epithelial tumour cells CD8 was the prominent subpopulation (CD8/CD4: 1·75/1). Aberrant HLA-DR expression was found in 21·05 per cent of bladder tumours. A strong correlation between CD4 and CD8 population densities and macrophages with the other subpopulations was noticed. In HLA-DR-positive tumours, there was no correlation of the percentage of positive cells with CD4- and CD8-positive lymphocyte populations. Various parameters including IL-2 receptors, B cells, CD8- and CD4-positive cells, and macrophages did not differ significantly between the groups of tumours expressing and not expressing HLA-DR antigen. There were no statistically significant differences in the population densities of B cells, CD8- or CD4-positive cells, IL-2 receptor, monocytes/macrophages, and HLA-DR antigen expression among various clinicopathological parameters, including growth pattern, histological grade and clinical stage or patient's age and sex. These findings suggest that in transitional cell carcinoma of the urinary bladder, HLA-DR antigen expression is independent of lymphocyte subpopulations. It is therefore possible that HLA-DR expression by tumour cells reflect the existence of separate HLA-DR-positive or HLA-DR-negative tumour clones.     

β2-Adrenergic receptor polymorphism and nitric oxide-dependent forearm blood flow responses to isoproterenol in humans

Polymorphisms in the gene encoding the β₂-adrenoceptor have been associated with interindividual differences in blood pressure and the diagnosis of hypertension. A common polymorphism resulting in a change from arginine to glycine at amino acid 16 (Arg16 → Gly) enhances agonist-promoted downregulation of receptor expression in vitro . It is unknown whether genotype-dependent differences in nitric oxide generation contribute to differences in vasodilator responses to β₂-agonists in vivo . To address this question, venous occlusion plethysmography was used to measure forearm blood flow responses to graded brachial artery infusions of the β-agonist isoproterenol in 41 healthy normotensive Caucasian adults (mean age (± s.d .) = 29 ± 6 years), who were either Arg16  ( n = 18)  or Gly16  ( n = 23)  homozygotes. Compared to Arg16 homozygotes, Gly16 homozygotes demonstrated significantly greater blood flow responses to isoproterenol ( P = 0.02). After inhibition of nitric oxide synthase by N ^γ-monomethyl- l -arginine, blood flow responses did not differ significantly between genotype groups ( P = 0.27). Consequently, effects of the Arg16 → Gly polymorphism on forearm blood flow responses to isoproterenol appear to be dependent on differences in endothelial generation of nitric oxide. In contrast to previous reports based on systemic infusions of β₂-agonists, our findings indicate that regional blood flow responses to locally infused isoproterenol are significantly greater in Gly16 than in Arg16 homozygotes.     

Overexpression of the aldo-keto reductase family protein AKR1B10 is highly correlated with smokers' non-small cell lung carcinomas.

PURPOSE: Squamous cell carcinoma (SCC) and adenocarcinoma of the lung are currently subject to similar treatment regimens despite distinct differences in histology and epidemiology. The aim of this study is to identify a molecular target with diagnostic and therapeutic values for SCC. EXPERIMENTAL DESIGN: Genes specifically up-regulated in SCC were explored through microarray analysis of 5 SCCs, 5 adenocarcinomas, 10 small cell lung carcinomas, 27 normal tissues, and 40 cancer cell lines. Clinical usefulness of these genes was subsequently examined mainly by immunohistochemical analysis. RESULTS: Seven genes, including aldo-keto reductase family 1, member B10 (AKR1B10), were identified as SCC-specific genes. AKR1B10 was further examined by immunohistochemical analysis of 101 non-small cell lung carcinomas (NSCLC) and its overexpression was observed in 27 of 32 (84.4%) SCCs and 19 of 65 (29.2%) adenocarcinomas. Multiple regression analysis showed that smoking was an independent variable responsible for AKR1B10 overexpression in NSCLCs (P < 0.01) and adenocarcinomas (P < 0.01). AKR1B10 staining was occasionally observed even in squamous metaplasia, a precancerous lesion of SCC. CONCLUSION: AKR1B10 was overexpressed in most cases with SCC, which is closely associated with smoking, and many adenocarcinoma cases of smokers. These results suggest that AKR1B10 is a potential diagnostic marker specific to smokers' NSCLCs and might be involved in tobacco-related carcinogenesis.     

Whole Grain Consumption and Breast Cancer: A Case-Control Study in Women

Objective: Whole grain consumption has long been associated with human health. However, its relationship with breast cancer remains not well understood and appreciated. The aim of this work was to evaluate the association between whole grain consumption and breast cancer in women. Methods: A case-control study was designed. Two hundred and fifty consecutive, newly diagnosed breast cancer female patients (56 ± 12 years) and 250 one-to-one age-matched controls were enrolled. A standardized, validated questionnaire assessing various sociodemographic, clinical, lifestyle, and dietary characteristics was applied through face-to-face interviews. Moreover, data on regular consumption of whole grains (i.e., never/rarely, 1–6 times/week, >7 times/week) were recorded. Overall dietary habits were assessed through the level of adherence to the Mediterranean diet using the MedDietScore (theoretical range 0–55). Results: Whole grain consumption of more than 7 times/week was associated with a 0.49-fold (odds ratio = 0.49; 95% confidence interval, 0.29, 0.82) lower likelihood of having breast cancer, after adjustments were made. Conclusions: This study suggested that whole grain consumption more than 7 times/week was consistently associated with reduced risk of breast cancer.     

Recurrent pneumonia due to persistent Chlamydia pneumoniae infection

Two cases of recurrent pneumonia due to Chlamydia pneumoniae are described. C. pneumoniae was continuously detected from the nasopharynx in both patients by the polymerase chain reaction and/or culture even with appropriate antibiotic therapy during the first episode. After eradication of C. pneumoniae with long-term macrolide therapy, the respiratory symptoms of both patients completely disappeared and no relapse was observed. These data indicate that new treatment strategies may be necessary to eradicate the organism in patients prone to persistent infection.