Genetic profiling and individualized prognosis of fracture

Fragility fracture is a serious public health problem in the world. The risk of fracture is determined by genetic and nongenetic clinical risk factors. This study sought to quantify the contribution of genetic profiling to fracture prognosis. The study was built on the ongoing Dubbo Osteoporosis Epidemiology Study, in which fracture and risk factors of 858 men and 1358 women had been monitored continuously from 1989 and 2008. Fragility fracture was ascertained by radiologic reports. Bone mineral density at the femoral neck was measured by dual‐energy X‐ray absorptiometry (DXA). Fifty independent genes with allele frequencies ranging from 0.01 to 0.60 and relative risks (RRs) ranging from 1.01 to 3.0 were simulated. Three predictive models were fitted to the data in which fracture was a function of (1) clinical risk factors only, (2) genes only, and (3) clinical risk factors and 50 genes. The area under the curve (AUC) for model 1 was 0.77, which was lower than that of model II (AUC = 0.82). Adding genes into the clinical risk factors model (model 3) increased the AUC to 0.88 and improved the accuracy of fracture classification by 45%, with most (41%) improvement in specificity. In the presence of clinical risk factors, the number of genes required to achieve an AUC of 0.85 was around 25. These results suggest that genetic profiling could enhance the predictive accuracy of fracture prognosis and help to identify high‐risk individuals for appropriate management of osteoporosis or intervention. © 2011 American Society for Bone and Mineral Research.     

Use of the Platelet Count/Spleen Diameter Ratio for the Noninvasive Diagnosis of Esophageal Varices in Patients with Schistosomiasis

Background/Aim:

In patients with liver cirrhosis, the platelet count/spleen diameter ratio has been validated as a parameter for the noninvasive diagnosis of esophageal varices. Schistosoma infection is a frequent cause of portal hypertension in Middle Eastern countries, and is associated with the development of esophageal varices. In this study we aimed to evaluate the platelet count/spleen diameter ratio as a noninvasive tool for the prediction of the presence of esophageal varices in patients with schistosoma-related chronic liver disease.

Patients and Methods:

Forty-three patients with hepatosplenic schistosomiasis underwent upper digestive endoscopy to check for the presence of esophageal varices. Furthermore, all patients underwent abdominal ultrasonography, and maximum spleen diameter (in mm) was measured. The platelet count/spleen diameter ratio was calculated in all patients.

Results:

Esophageal varices were found in 31 patients (72%). Age and gender were not significantly different between patients with and without varices. In patients with varices, median platelet count (82,000/μL versus 172,000/μL, P < 0.0001) and platelet count/spleen diameter ratio (571 versus 1651, P < 0.0001) were significantly lower, while spleen diameter (147 mm versus 109 mm, P = 0.0006) was significantly larger. In multivariate analysis, the platelet count/spleen diameter ratio was the only parameter independently associated with the presence of varices (P < 0.0001).

Conclusions:

In this study we have validated the use of the platelet count/spleen diameter ratio for the noninvasive diagnosis of esophageal varices in patients with portal hypertension caused by schistosoma infection. In these patients, the platelet count/spleen diameter ratio might be used to allow better rationalization of medical resources and use of endoscopy.     

Enhanced effect of soluble transforming growth factor-β receptor II and IFN-γ fusion protein in reversing hepatic fibrosis

Objective

To examine the in vivo anti-fibrotic effect of rat soluble transforming growth factor β receptor II (RsTβRII) and IFN-γ fusion protein (RsTβRII-IFN-γ) in rat hepatic fibrosis model.

Methods

Model rats were divided into five groups and treated i.m. for 8 weeks: 1) fibrotic model group (each rat, 100 μl of 0.9% NaCl day^-1); 2) RsTβRII-IFN-γ treatment group (each rat, 0.136 mg· day^-1); 3) IFN-γ treatment group (each rat, 7.5 MU· day^-1); 4) RsTβRII treatment group (each rat, 0.048 mg· day^-1); and 5) mixture of IFN-γ and RsTβRII treatment group (each rat, IFN-γ 7.5 MU· day^-1+ RsTβRII 0.048 mg· day^-1). After treatment, hepatic fibrogenesis was evaluated by histopathological analysis and measurement of collagen III, α-smooth muscle actin (α-SMA), TGF-β1, TGF-βRII and their mRNA.

Results

Immunohistochemistry, Western blot and real-time RT-PCR showed that RsTβRII-IFN-γ treatment significantly inhibited liver expression of collagen III, α-SMA, TGF-β1 and TGF-βRII at both protein and mRNA levels. Histopathological analysis also showed that the enhanced anti-fibrotic effects were achieved in model rats treated with RsTβRII-IFN-γ.

Conclusion

Our results confirmed that RsTβRII-IFN-γ has the enhanced effects in reversing hepatic fibrosis.     

Insulin priming effect on estradiol-induced breast cancer metabolism and growth

Diabetes is a risk factor for breast cancer development and is associated with poor prognosis for breast cancer patients. However, the molecular and biochemical mechanisms underlying the association between diabetes and breast cancer have not been fully elucidated. Here, we investigated estradiol response in MCF-7 breast cancer cells with or without chronic exposure to insulin. We found that insulin priming is necessary and specific for estradiol-induced cancer cell growth, and induces anaplerotic shunting of glucose into macromolecule biosynthesis in the estradiol treated cells. Treatment with ERK or Akt specific inhibitors, U0126 or {"type":"entrez-nucleotide","attrs":{"text":"LY294002","term_id":"1257998346","term_text":"LY294002"}}LY294002, respectively, suppressed estradiol-induced growth. Interestingly, molecular analysis revealed that estradiol treatment markedly increases expression of cyclin A and B, and decreases p21 and p27 in the insulin-primed cells. In addition, estradiol treatment activated metabolic genes in pentose phosphate (PPP) and serine biosynthesis pathways in the insulin-primed cells while insulin priming decreased metabolic gene expression associated with glucose catabolism in the breast cancer cells. Finally, we found that anti-diabetic drug metformin and AMPK ligand AICAR, but not thiazolidinediones (TZDs), specifically suppress the estradiol-induced cellular growth in the insulin-primed cells. These findings suggest that estrogen receptor (ER) activation under chronic hyperinsulinemic condition increases breast cancer growth through the modulation of cell cycle and apoptotic factors and nutrient metabolism, and further provide a mechanistic evidence for the clinical benefit of metformin use for ER-positive breast cancer patients with diabetes.     

肠毒素大肠杆菌攻毒小鼠模型的建立以及疫苗候选株保护效果的评价

目的:建立肠毒素大肠杆菌攻毒小鼠模型以及应用模型对疫苗候选株免疫效果进行评价．方法:通过鼻饲半数致死量(LD50)肠毒素大肠杆菌E44813,E44815和E11881A观察小鼠肺病理学变化、肺部细菌清除情况变化,建立肠毒素大肠杆菌鼻饲小鼠模型;应用鼻饲小鼠模型观察疫苗候选株FE1,FE3,FE6保护效果．结果:鼻饲LD50剂量肠毒素大肠杆菌小鼠的病理特征是肺组织存在大量的淋巴细胞、巨噬细胞、中性粒细胞和浆细胞,为多病灶支气管肺炎,肺部细菌清除缓慢,至第7天仍能检测到105数量级的细菌．应用疫苗候选株免疫后进行攻毒,小鼠没有发病和死亡,病理特征主要是淋巴细胞少量增多,肺部细菌清除迅速,至第7天已检测不到细菌,与对照有显著性差异(0 CFU／g vs 6．2×105,5．4×105,2．3×105 CFU／g,P<0．05)．结论:肠毒素大肠杆菌鼻饲小鼠模型能够为疫苗筛选和评价提供了有效途径,同时也证实了疫苗候选株FE1,FE3,FE6具有良好的免疫保护效果．     

An in vitro limiting-dilution assay of long-term repopulating hematopoietic stem cells in the mouse

We have developed a limiting-dilution assay of long-term repopulating hematopoietic stem cells in the mouse using a miniturized stroma- dependent bone marrow culture assay in vitro. The cells were overlaid on irradiated stromal layers in microtiter wells in a range of concentrations, and frequencies of cobblestone area-forming cells (CAFC) were calculated by employing Poisson statistics. The production of secondary granulocyte/macrophage colony-forming units (CFU-G/M) in the adherent layer of individual wells was correlated with the presence of such cobblestone areas. CAFC frequencies were determined in bone marrow cell suspensions that were either enriched for marrow repopulating ability (MRA) in vivo, while depleted for spleen colony- forming units (CFU-S), or vice versa. The separation of bone marrow cells (BMC) was either based on centrifugal elutriation, or monoclonal antibody-mediated magnetic depletion of cells carrying cell surface differentiation antigens, and subsequent sorting on the basis of light scatter and rhodamine-123 retention as a measure of mitochondrial activity. In addition, 5-fluorouracil-resistant BMC were studied. Our investigations show that a time-dependent cobblestone area formation exists that reflects the turnover time and primitiveness of CAFC. The frequency of precursors forming cobblestone areas on day 28 after overlay is proposed to be a measure for MRA, whereas the day-7 CAFC frequency closely corresponds with day-12 CFU-S numbers in the suspensions tested.