Trenbolone enhances myogenic differentiation by enhancing β-catenin signaling in muscle-derived stem cells of cattle

Testosterone is a key hormone regulating animal growth and development, which promotes skeletal muscle growth and inhibits fat deposition; however, the underlying mechanisms remain poorly defined. Because canonical Wingless and Int/β-catenin signaling promotes myogenesis, we hypothesized that testosterone regulates myogenesis through enhancing the β-catenin signaling pathway and the expression of its targeted genes. Muscle-derived stem cells were prepared from the skeletal muscle of fetal calf at day 180 of gestation and treated with or without trenbolone (10 nM), a synthetic analog of testosterone, in a myogenic medium. Trenbolone treatment increased the protein levels of MyoD and myosin heavy chain, as well as the androgen receptor content. The myogenic effect of trenbolone was blocked by cyproterone acetate, a specific inhibitor of androgen receptor, showing that the myogenic effect of trenbolone was mediated by the androgen receptor. Immunoprecipitation showed that androgen receptor and β-catenin formed a complex, which was increased by trenbolone treatment. Trenbolone activated adenosine monophosphate-activated protein kinase, which might phosphorylate β-catenin at Ser552, stabilizing β-catenin. Indeed, both cytoplasmic and nuclear β-catenin levels were increased after trenbolone treatment. As a result, β-catenin-mediated transcriptional activity was enhanced by trenbolone treatment. In conclusion, these data provide evidence that testosterone increases cellular β-catenin content which promotes the expression of β-catenin-targeted genes and myogenesis in the muscle-derived stem cells of cattle.

Reduction malarplasty using an L-shaped osteotomy through intraoral and sideburns incisions

The slender, oval-shaped face is considered to be attractive in East Asia. To obtain the ideal contour of the midface, reduction malarplasty has been popularized in oriental countries in recent years. This report describes a surgical technique for reduction of the zygomatic body and arch. After labiobuccal vestibular incisions are made, the anterior zygomatic body and lateral orbital rim are exposed by subperiosteal dissection. Thereafter, an L-shaped osteotomy is performed. Two parallel horizontal osteotomies are made in the anterior part of the zygomatic body, and the middle bone segment is removed. The zygomatic arch root is fractured through a small sideburn incision just anterior to the articular tubercle. Finally, the freed zygomatic complex is medially repositioned and fixed with one or two bicortex screws. Operations on 32 patients demonstrated that this technique may be a sound method for malar complex reduction, with the advantages of simple manipulation, stable fixation, and less risk of a drooping face.

Experimental constraints on left-right symmetric models from muon decay

The TWIST Collaboration has completed a new measurement of the energy-angle spectrum of positrons from the decay of highly polarized muons. A simultaneous measurement of the muon decay parameters ρ, δ, and P(μ)(π)ξ tests the standard model in a purely leptonic process and provides improved limits for relevant extensions to the standard model. Specifically, for the generalized left-right symmetric model |(g(R)/g(L))ζ|<0.020 and (g(L)/g(R))m(2)>578  GeV/c(2), both 90% C.L.

Empowerment and its effects on clinical nurses in central China

BACKGROUND

Chinese healthcare institutions have undergone constant changes in recent years. A large number of research studies conducted on work-related factors revealed that nurses in China experienced a low level of job satisfaction and a high level of turnover intention. Empowerment is one of the most important concepts in nursing and is most relevant to the study of nursing professionals' job-related outcomes.

AIM

The aim of this study was to test the Job Characteristics Model and the mediating role of structural empowerment on the relationships between the job characteristics and work-related outcomes among clinical nurses from central China.

METHODS

Three self-reported questionnaires were administered to a sample of 238 clinical nurses from two hospitals in central China. The results were analyzed using descriptive statistics, Pearson's correlation analysis and multiple linear regressions.

FINDINGS

Correlations were significant between job characteristics and job-related outcomes, and the estimated model on the effect of empowerment reduced the unique contribution of job characteristics on internal work motivation (from 17.2% to 13.0%) and general job satisfaction (from 13.4% to 10.1%), and eliminated the unique contribution of job characteristics on growth satisfaction (from 18.4% to 0%).

CONCLUSIONS

The results supported the Job Characteristics Model in a nursing sample and empowerment mediated the impact of job characteristics on internal work motivation and general job satisfaction partially and on growth satisfaction completely.

Calculation of the expected bandwidth for a mid-infrared supercontinuum source based on As(2)S(3) chalcogenide photonic crystal fibers

We computationally investigate supercontinuum generation in an As(2)S(3) solid core photonic crystal fiber (PCF) with a hexagonal cladding of air holes. We study the effect of varying the system (fiber and input pulse) parameters on the output bandwidth. We find that there is significant variation of the measured bandwidth with small changes in the system parameters due to the complex structure of the supercontinuum spectral output. This variation implies that one cannot accurately calculate the experimentally-expected bandwidth from a single numerical simulation. We propose the use of a smoothed and ensemble-averaged bandwidth that is expected to be a better predictor of the bandwidth of the supercontinuum spectra that would be produced in experimental systems. We show that the fluctuations are considerably reduced, allowing us to calculate the bandwidth more accurately. Using this smoothed and ensemble averaged bandwidth, we maximize the output bandwidth with a pump wavelength of 2.8 μm and obtain a supercontinuum spectrum that extends from 2.5 μm to 6.2 μm with an uncertainty of ± 0.5 μm. The optimized bandwidth is consistent with prior work, but with a significantly increased accuracy..

Insulin-like growth factor-1 suspended in hyaluronan improves cartilage and subchondral cancellous bone repair in osteoarthritis of temporomandibular joint

This study sought to evaluate the effects of intra-articular injection of insulin-like growth factor-1 (IGF-1) suspended in hyaluronan (HA) on the cartilage and subchondral cancellous bone repair in osteoarthritis (OA) of the temporomandibular joint (TMJ). Disc perforation was performed bilaterally in rabbit TMJs to induce OA. Four groups of animals (n=12) received OA induction only, and either intra-articular HA injection alone, intra-articular IGF-1 injection alone, or a combination of HA and IGF-1 injection. All therapy was begun 4 weeks after OA induction. The animals were killed 12 or 24 weeks after the first injection, for histology and micro-CT examinations. Two additional animals were used as normal controls. Typical cartilage and subchondral cancellous bone lesions were observed in the OA group. No protective effect on cartilage and subchondral cancellous bone was found in the HA or IGF-1 alone groups. Better histological repair and nearly normal micro-architectural properties of the subchondral cancellous bone were observed in the HA+IGF-1 group compared with the HA or IGF-1 alone groups. HA may be used as an effective carrier for intra-articular injection of IGF-1 and the combination of HA/IGF-1 shows promise as a new rational approach to therapy of TMJ OA.

Tetranectin and apolipoprotein A-I in cerebrospinal fluid as potential biomarkers for Parkinson's disease

OBJECTIVE

The application of biomarkers may potentially improve the efficiency of the diagnosis for Parkinson's disease (PD). However, no reliable biomarker has been identified to date. This study is aimed to identify proteins that might serve as potential biomarkers for PD diagnosis or pathogenesis.

MATERIALS AND METHODS

Two-dimensional difference gel electrophoresis (2D DIGE) technique, in combination with matrix-assisted laser desorption/ionization-time of flight mass spectrometry (MALDI-TOF MS), was used to determine the differentially expressed cerebrospinal fluid (CSF) proteins in PD patients (n = 3) compared with normal controls (n = 3). Selected proteins were further confirmed by Western blotting analysis in the CSF of PD patients (n = 8), Alzheimer's disease (AD) patients (n = 6) and normal control subjects (n = 7).

RESULTS

Eight proteins were identified after MS and protein database interrogation. In the CSF of PD patients, the expression levels of one isoform of apolipoprotein A-I (apoA-I), tetranectin, myosin phosphatase target subunit 1 (MYPT1), and two unknown proteins were down-regulated, whereas the expression levels of another apoA-I isoform, proapolipoprotein, and lipoprotein were up-regulated. Western blotting indicates that the expression of tetranectin was reduced in the CSF from PD patients and elevated in AD, while the expression of apoA-I was changed only in the CSF from PD patients.

CONCLUSION

Our preliminary results suggest that tetranectin and apoA-I may serve as potential biomarkers for PD, though further validation is needed.

Systemic treatment with strontium ranelate promotes tibial fracture healing in ovariectomized rats

Systemic treatment with strontium ranelate (SR) was performed on ovariectomized (OVX) rats with fractured tibiae. Callus quality was assessed by radiographic, histological, micro-computerized tomography, and biomechanical examinations at 4 and 8 weeks after fracture. Results revealed that systemic applied SR promoted osteoporotic fracture healing.

INTRODUCTION

Several studies have demonstrated the dual effect of SR on osteoporotic and undisturbed bone. However, reports of their effect on osteoporotic fracture healing are limited. This study was designed to investigate the effects of SR on bone regeneration in OVX rats with fractured tibiae.

METHODS

Three months after being OVX, female Sprague-Dawley rats accepted bilateral osteotomy on proximal tibiae fixed with intramedullary wires and were divided into two groups: OVX and OVX + SR (625 mg/kg/day). Callus quality was evaluated at 4 and 8 weeks postfracture.

RESULTS

Compared with OVX group, SR treatment significantly increased bone formation, BMD, biomechanical strength, and improved microstructural properties of the callus. The ultimate load was increased by 211.0% and 61.4% (p<0.01), and the total bone volume of callus by 74.8% and 79.3% (p<0.01) at 4 and 8 weeks postfracture, respectively. SR treatment also promoted healing progress with increased osteogenesis at 4 weeks; more mature and tightly arranged woven or lamellar bone at 8 weeks across the fracture gap in histological analysis.

CONCLUSION

This study suggests that systemic treatment with strontium ranelate could promote tibial fracture healing in OVX rats.

Establishment of a porcine model for lobar lung auto-transplantation

OBJECTIVE

The aim of this study was to develop a porcine model of left single lung auto-transplantation.

METHODS

Eighteen 50-kg male domestic pigs underwent left pneumonectomy and lobar lung auto-transplantation (left lower lobe). Each animal was allocated to a perfusion protocol during surgery: group I, cold saline (n = 6); group II, cold heparin (n = 6); and group III, cold Euro-Collins (n = 6). We measured changes of partial pressure of oxygen in pulmonary vein blood (PvO(2)), partial pressure of carbon dioxide in pulmonary vein blood (PvCO(2)), lung compliance, and mean pulmonary artery pressure.

RESULTS

The postoperative survival rate was 100%. PvO(2), PvCO(2), mean pulmonary artery pressure, and lung compliance of the left lower lobe showed a significant difference between the saline and the heparin groups or the Euro-Collins group (P < .05), whereas there was no significant difference between the heparin and the Euro-Collins groups.

CONCLUSION

Compared with other species, humans and pigs show remarkable anatomical and physiological similarity. It is useful experimental animal model to evaluate pulmonary function and grafting protocols following lobar lung transplantation.

A rare case of Gerbode defect associated with double orifice mitral valve

Gerbode defect is an unusual cardiac defect; its association with a double orifice mitral valve has not been previously reported. We present a case of a 45-year-old woman who complained of palpitation and dyspnea on exertion. Echocardiography revealed an abnormal communication between the left ventricle and the right atrium, but misinterpreted a double orifice mitral valve as fusion of the anterolateral commissure. The Gerbode defect was closed during cardiopulmonary bypass, while the double orifice mitral valve was left untouched. The patient was discharged 16 days postoperatively.

From (pi,0) magnetic order to superconductivity with (pi,pi) magnetic resonance in Fe(1.02)Te(1-x)Se(x)

The iron chalcogenide Fe(1+y)(Te(1-x)Se(x)) is structurally the simplest of the Fe-based superconductors. Although the Fermi surface is similar to iron pnictides, the parent compound Fe(1+y)Te exhibits antiferromagnetic order with an in-plane magnetic wave vector (pi,0) (ref. 6). This contrasts the pnictide parent compounds where the magnetic order has an in-plane magnetic wave vector (pi,pi) that connects hole and electron parts of the Fermi surface. Despite these differences, both the pnictide and chalcogenide Fe superconductors exhibit a superconducting spin resonance around (pi,pi) (refs 9, 10, 11). A central question in this burgeoning field is therefore how (pi,pi) superconductivity can emerge from a (pi,0) magnetic instability. Here, we report that the magnetic soft mode evolving from the (pi,0)-type magnetic long-range order is associated with weak charge carrier localization. Bulk superconductivity occurs as magnetic correlations at (pi,0) are suppressed and the mode at (pi, pi) becomes dominant for x>0.29. Our results suggest a common magnetic origin for superconductivity in iron chalcogenide and pnictide superconductors.

Multiple copies of 16s rRNA gene affect the restriction patterns and DGGE profile as revealed by analysis of genome database

The use of 16S rRNA gene has been a "golden" method to determine the diversity of microbial communities in environmental samples, phylogenetic relationships of prokaryotes and taxonomic position of newly isolated organisms. However due to the presence of multiple heterogeneous 16S rRNA gene copies in many strains, the interpretation of microbial ecology via 16S rRNA sequences is complicated. Purpose of present paper is to demonstrate the extent to which the multiple heterogeneous 16S rRNA gene copies affect RFLP patterns and DGG E profiles by using the genome database. In present genome database, there are 782 bacterial strains in total whose genomes have been completely sequenced and annotated. Among the total strains, 639 strains (82%) possess multiple 16S rRNA gene copies, 415 strains (53%) whose multiple copies are heterogeneous in sequences as revealed by alignment, 236 strains (30%) whose multiple copies show different restrict patterns by CSP61 + Hinfl, MspI + Rsal or HhaI as analyzed in silico. Polymorphisms of the multiple copies in certain strains were further characterized by G + C% and phylogentic distances based on the sequences of V3 region, which are linked to DGGE patters. Polymorphisms of a few strains were shown as examples. Using artificial communities, it is demonstrated that the presence of multiple heterogeneous 16S rRNA gene copies potentially leads to over-estimation of the diversity of a community. It is suggested that care must be taken when interpreting 16S rRNA-based RFLP and DGGE data and profiling an environmental community.

Polymorphisms in CFH, HTRA1 and CX3CR1 confer risk to exudative age-related macular degeneration in Han Chinese

BACKGROUND/AIMS

Single nucleotide polymorphisms (SNPs) in Complement Factor H (CFH), HTRA1 and CX3CR1 are associated with age-related macular degeneration (AMD) in Caucasian population. We aimed to determine whether, and of what magnitude, these AMD susceptibility SNPs are associated with exudative AMD in Han Chinese.

METHODS

Exudative AMD cases and age-matched controls were recruited from Nantong University Hospital (109 cases, 150 controls). Six SNPs in CFH, HTRA1 and CX3CR1 were genotyped. The allele/genotype frequencies were compared between the case and the control. Interactions of SNP-SNP or SNP-smoking status were assessed.

RESULTS

The CFH rs800292 showed significant associations with a reduced risk for exudative AMD. CX3CR1 V249I and T280M and the HTRA1 promoter SNP were significantly associated with the risk of exudative AMD. The two SNPs in CX3CR1 were in complete linkage disequilibrium. None of the AMD-susceptibility SNPs had interactions with each other or with smoking status to confer an altered AMD risk.

CONCLUSIONS

We have replicated the associations of the CFH and HTRA1 SNPs and report for the first time the association of CX3CR1 with exudative AMD in Han Chinese. There was no interaction among the SNPs from different genes, indicating that they might alter the AMD risk independently.