Is decreased bone mineral density associated with development of scoliosis? A bipedal osteopenic rat model

<p>Abstract</p> <p>Background</p> <p>An association between adolescent idiopathic scoliosis and osteopenia has been proposed to exist. It is still not clear whether there is such an association and if so, whether osteopenia is a causative factor or a consequence. Our previous pilot studies have suggested the presence of osteopenia in scoliotic animals. The aim of this study was to investigate the development of scoliosis in an unpinealectomized bipedal osteopenic rat model, implementing osteoporosis as a causative factor.</p> <p>Methods</p> <p>Fifty Sprague-Dawley rats were rendered bipedal at the 3^rdpostnatal week and separated into control (25 rats) and heparin (25 rats receiving 1 IU/gr body weight/day) groups. DEXA scans after 4 weeks of heparin administration showed low bone mass in the heparin group. Anteroposterior and lateral x-rays of the surviving 42 animals (19 in heparin and 23 in control groups) were taken under anesthesia at the 40^thweek to evaluate for spinal deformity. Additional histomorphometric analysis was done on spine specimens to confirm the low bone mass in heparin receiving animals. Results of the DEXA scans, histomorphometric analysis and radiological data were compared between the groups.</p> <p>Results</p> <p>Bone mineral densities of rats in the heparin group were significantly lower than the control group as evidenced by both the DEXA scans and histomorphometric analyses. However, the incidence of scoliosis (82% in heparin and 65% in control; p > 0.05) as well as the curve magnitudes (12.1 ± 3.8 in heparin versus 10.1 ± 4.3 degrees in control; p > 0.05) were not significantly different. Osteopenic rats were significantly less kyphotic compared to control specimens (p = 0.001).</p> <p>Conclusions</p> <p>This study has revealed two important findings. One is that bipedality (in the absence of pinealectomy) by itself may be a cause of scoliosis in this animal model. Further studies on animal models need to consider bipedality as an independent factor. Secondly, relative hypokyphosis in osteopenic animals may have important implications. The absence of sagittal plane analyses in previous studies makes comparison impossible, but nonetheless these findings suggest that osteopenia may be important in the development of 3D deformity in adolescent idiopathic scoliosis.</p

A Mouse Model of Acrodermatitis Enteropathica: Loss of Intestine Zinc Transporter ZIP4 (Slc39a4) Disrupts the Stem Cell Niche and Intestine Integrity

Loss-of-function of the zinc transporter ZIP4 in the mouse intestine mimics the lethal human disease acrodermatitis enteropathica. This is a rare disease in humans that is not well understood. Our studies demonstrate the paramount importance of ZIP4 in the intestine in this disease and reveal that a root cause of lethality is disruption of the intestine stem cell niche and impaired function of the small intestine. This, in turn, leads to dramatic weight loss and death unless treated with exogenous zinc

P3HT-Based Solar Cells: Structural Properties and Photovoltaic Performance

Each year we are bombarded with B.Sc. and Ph.D. applications from students that want to improve the world. They have learned that their future depends on changing the type of fuel we use and that solar energy is our future. The hope and energy of these young people will transform future energy technologies, but it will not happen quickly. Organic photovoltaic devices are easy to sketch, but the materials, processing steps, and ways of measuring the properties of the materials are very complicated. It is not trivial to make a systematic measurement that will change the way other research groups think or practice. In approaching this chapter, we thought about what a new researcher would need to know about organic photovoltaic devices and materials in order to have a good start in the subject. Then, we simplified that to focus on what a new researcher would need to know about poly-3-hexylthiophene:phenyl-C61-butyric acid methyl ester blends (P3HT: PCBM) to make research progress with these materials. This chapter is by no means authoritative or a compendium of all things on P3HT:PCBM. We have selected to explain how the sample fabrication techniques lead to control of morphology and structural features and how these morphological features have specific optical and electronic consequences for organic photovoltaic device applications

Evaluation of capture ELISA for detection of antineutrophil cytoplasmic antibodies directed against proteinase 3 in Wegener's granulomatosis: first results from a multicentre study

Objective: To evaluate the performance characteristics of direct and capture ELISA for the detection of PR3-ANCA in Wegener's granulomatosis (WG) in international ANCA reference laboratories. Methods: Serum samples were derived from patients with histological and clinical diagnosis of WG (n = 60), rheumatoid arthritis (RA) (n = 30) and healthy controls (n = 30). Each of them was tested for the presence of ANCA by indirect immunofluorescence technique (IFT), direct and capture ELISA in six international reference laboratories (Massachusetts General Hospital, Boston; Wieslab AB, Lund; University of Maastricht; University Hospital Groningen; Mayo Clinic, Rochester; Rheumaklinik Bad Bramstedt/University of Schleswig-Holstein Campus Lubeck). Each centre tested the sera according to their house protocols of IFT and ELISA. The diagnostic performance of each test was estimated by receiver operating characteristic curve analysis and sensitivity and specificity in detection of ANCA/PR3-ANCA were calculated for the respective methods. Results: In patients histologically and clinically known as WG, the detection of ANCA by IFT varied between 52 and 83% among the participating centres. PR3-ANCA positivity with the different ELISAs ranged from 53 to 80% in direct ELISA and from 72 to 76% in capture ELISA. While most capture ELISAs successfully detected PR3-ANCA, there were significant differences between IFT and direct ELISA results between laboratories. ROC curve analysis demonstrated that in five of six laboratories the overall diagnostic performance of capture ELISA was superior to IFT and direct ELISA, respectively. Conclusion: Capture ELISA is a highly sensitive assay for detection of PR3-ANCA in WG and should be used in conjunction with compatible clinical picture and histological evidence