Sodium tanshinone IIA sulfate protects myocardium against paraquat-induced toxicity through activating the Nrf2 signaling pathway in rats

Objective:

To investigate the therapeutic effect and mechanism of sodium tanshinone IIA sulfate (STS) on paraquat (PQ)-induced myocardial injuries in a rat model.

Methods:

Healthy adult Sprague Dawley rats were randomly divided into normal control, PQ, and PQ + STS groups. PQ group was given a single intragastric administration of PQ (80 mg/kg). PQ + STS group was intraperitoneally injected with STS (1 ml/kg) at 30 min following PQ exposure. Rats in control and PQ groups were injected with equal amount of saline. After 12, 24, 48, and 72 h, rats were killed, and the apoptosis of myocardial cells was detected. Myocardial expression of Bax and Bcl-2 was measured. The activity of the nuclear erythroid 2-related factor 2 (Nrf2) pathway was assessed by Western blot.

Results:

The apoptotic cells in PQ group were significantly increased in a time-dependent manner compared with the control group ( p < 0.01). The rats in PQ group exhibited significantly lower Bcl-2 expression, but notably higher Bax expression at 12, 24, 48, and 72 h after PQ exposure ( p < 0.05 or 0.01). STS intervention markedly reduced the proportion of apoptotic myocardial cells, increased Bcl-2 expression, and decreased Bax expression at 24, 48, and 72 h after treatment ( p < 0.05 or 0.01). The expression of phosphorylated Nrf2 and heme oxygenase 1 in PQ + STS group was significantly increased compared with PQ and control groups ( p < 0.05 or 0.01).

Conclusion:

STS effectively inhibits PQ-induced myocardial cell apoptosis in rats via modulating the Nrf2 pathway, suggesting its potential as a promising therapeutic agent for PQ-induced myocardium damage.

Isolation and biological characteristics of multipotent mesenchymal stromal cells derived from chick embryo intestine

1. Over the past decade, rapid advancement in isolation methods for identifying markers of the once elusive intestinal stem cell (ISC) populations has laid the foundation for unravelling their complex interrelationships during homeostasis. Study on ISC in avian intestinal tissue might play a pivotal foundation for further studies on the epithelial-to-mesenchymal transition (EMT) in gastrointestinal disease and cell-based therapy as well as intestinal tissue engineering. 2. The following experiment isolated a population of fibroblast-like, plastic adhering cells derived from chick embryo intestine, showing a strong self-renewing and proliferative ability, which was maintained in vitro up to passage 25. The findings included growth characteristics, detected expression of cell surface markers and characterised the capability of these cells to differentiate towards the osteogenic, adipogenic, and chondrogenic cell lineages. 3. RT-PCR analysis showed that these cells from chick embryos expressed mesenchymal stromal cell markers CD44, CD90 and VIMENTIN as well as ISC-specific genes LGR5, MI1, SMOC2, BMI1, and HOPX. Immunofluorescence and flow cytometry confirmed this biology characterisation further. 4. In conclusion, cells were isolated from the intestine of 18-day-old chicken embryos that exhibited the biological characteristics of mesenchymal stromal cells as well as markers of intestinal stem cells. Our findings may provide a novel insight for in vitro cell culture and characteristics of ISCs in avian species, which may also indicate a benefit for obtaining cell source for intestinal tissue engineering as well as cell-based investigation for gastrointestinal disease and treatment.

[Detection of root cracks after root canal preparation using rotary NiTi systems by optical coherence tomography (OCT) scan]

OBJECTIVE

To evaluate the accuracy of optical coherence tomography (OCT) in detecting root cracks after root canal instrumentation using histological gold standard.

METHODS

Twenty complete extracted human mandibular incisors that were free of caries, calculus, and root treatment were chosen and accessed coronally with a diamond bur, then mounted in resin blocks with alginate impression material using simulated periodontal ligaments, and the apex was exposed 3 mm. The teeth were stored in water at room temperature. Then the teeth were then instrumented to the major apical foramen (AF) at #30/0.09 using ProTaper Universal rotary nickel titanium system (Dentsply Maillefer, Ballaigues, Switzerland), irrigation with 1% sodium hypochlorite (NaOCl) by using a 26-gauge needle followed after each instrument. The apical root was scanned with 360° of rotation by Swept-Source Optical Coherence Tomography (SS-OCT) (wavelength: 1 310 nm, scan rate: 20 kHz, axial resolution: 16 μm) with driving device (stepper motor and lifting platform). The reconstruction images of axial planes 1, 2 and 3 mm from the apex were examined and the root cracks were blindly diagnosed by two observers. The horizontal section was performed at 1, 2 and 3 mm from the apex using low speed disc saw (Leica SP1600, Wetzlar, Germany). The presence of cracks was noted under an optical stereomicroscope (ZOOM-630E) with a cold light source using as gold standard to evaluate the accuracy of OCT in detecting root cracks after root canal instrumentation.

RESULTS

After canals instrumentation with ProTaper Universal rotary nickel titanium system to #30/0.09, root cracks were detected in 9 of 20 teeth by histological examination. Crack lines were observed on 13 of 60 horizontal sections and cracks on 12 of the 13 sections were detected by OCT. No cracks were observed in the other 47 of the 60 horizontal sections,none of which was misdiagnosed by OCT. The overall accuracy rate for detection of root cracks with OCT was 0.983, the sensitivity was 0.923, the specificity was 1.000, the positive predictive value (PPV) was 1.000 and the negative predictive value (NPV) was 0.979.

CONCLUSION

OCT may be a promising nondestructive imaging method for diagnosing root canal cracks after canal instrumentation.

Autism-associated Dyrk1a truncation mutants impair neuronal dendritic and spine growth and interfere with postnatal cortical development

Autism is a prevailing neurodevelopmental disorder with a large genetic/genomic component. Recently, the dual-specificity tyrosine-(Y)-phosphorylation-regulated kinase 1 A (DYRK1A) gene was implicated as a risk factor for autism spectrum disorder (ASD). We identified five DYRK1A variants in ASD patients and found that the dose of DYRK1A protein has a crucial role in various aspects of postnatal neural development. Dyrk1a loss of function and gain of function led to defects in dendritic growth, dendritic spine development and radial migration during cortical development. Importantly, two autism-associated truncations, R205X and E239X, were shown to be Dyrk1a loss-of-function mutants. Studies of the truncated Dyrk1a mutants may provide new insights into the role of Dyrk1a in brain development, as well as the role of Dyrk1a loss of function in the pathophysiology of autism.

Fabrication of PEGylated graphitic carbon nitride quantum dots as traceable, pH-sensitive drug delivery systems

Fluorescent PEGylated carbon nitride quantum dots are synthesized and characterized for traceable drug delivery and cell imaging.

Rebuilding of destroyed spin squeezing in noisy environments

We investigate the process of spin squeezing in a ferromagnetic dipolar spin-1 Bose-Einstein condensate under the driven one-axis twisting scheme, with emphasis on the detrimental effect of noisy environments (stray magnetic fields) which completely destroy the spin squeezing. By applying concatenated dynamical decoupling pulse sequences with a moderate bias magnetic field to suppress the effect of the noisy environments, we faithfully reconstruct the spin squeezing process under realistic experimental conditions. Our noise-resistant method is ready to be employed to generate the spin squeezed state in a dipolar spin-1 Bose-Einstein condensate and paves a feasible way to the Heisenberg-limit quantum metrology.

A tremendous expansion of copy number in crossbred bulls ( × )

Crossbreeding between cattle () and yak () exhibits significant hybrid advantages in milk yield and meat production. By contrast, cattle-yak F hybrid bulls are sterile. Copy number variations (CNV) of multicopy gene families in male-specific regions of the mammalian Y chromosome (MSY) affect human and animal fertility. The present study investigated CNV of (), (), (), and () in 5 yak breed bulls ( = 63), cattle-yak F ( = 22) and F ( = 2) hybrid bulls, and Chinese Yellow (CY) cattle bulls ( = 10) by quantitative real-time PCR. showed restricted amplification in yak bulls in that the average geometric mean copy number (CN) was estimated to be 4 copies. The most compelling finding is that there is a tremendous expansion of CN in F hybrids (385 copies; 95% confidence interval [CI] = 351-421) and F hybrids (356 copies) compared with the male parent breed CY cattle (142 copies; 95% CI = 95-211). Copy numbers of and were also extensively expanded on the Y chromosome in yak and CY cattle bulls. The geometric mean CN of and were estimated to be 123 (95% CI = 114-132) and 250 copies (95% CI = 233-268) in yak bulls and 71 (95% CI = 61-82) and 133 (95% CI = 107-164) copies in CY cattle, respectively. Yak and CY cattle have 2 copies of the gene on the Y chromosome. Similarly to gene, the F and F hybrid bulls have higher CN of , , and than CY cattle ( < 0.01). These results indicated that the MSY of yak and cattle-yak crossbred hybrids was fundamentally different from cattle MSY in the context of genomic organization. Based on the model of cattle-yak F and F hybrid bull sterility, the CNV of may serve as a potential risk factor for crossbred bull ( × ) infertility. To our knowledge, this is the first study to examine differences in multicopy genes in MSY between yak and cattle-yak bulls.

Opioids increase hip fracture risk: a meta-analysis

The relationship between hip fracture risk and opioid use remains controversial. Thus, we performed a meta-analysis to assess the risk of hip fracture among opioid users. PubMed and EMBASE were searched for studies published from the inception of the databases until June 2015. The information was extracted independently by two teams of authors. When the heterogeneity was significant, the random-effects model was used to calculate the overall pooled risk estimates. Ten studies with 697,011 patients were included in the final meta-analysis. The overall combined relative risk for the use of opioids and hip fracture was 1.54 [95 % confidence interval (CI) 1.34-1.77]. Subgroup analyses revealed sources of heterogeneity, and sensitivity analysis indicated stable results, and no publication bias was observed. This meta-analysis demonstrates that opioids significantly increase the risk of hip fracture.

Tuning the electronic and magnetic properties of graphene-like SiGe hybrid nanosheets by surface functionalization

In this paper, the structural, electronic and magnetic properties of fully and partially surface modified SiGe nanosheets (NSs) have been investigated using first-principles calculations based on density functional theory. The results demonstrate that the electronic and magnetic properties of SiGe NSs can be tuned by decorating H, Cl and F atoms on Si sites in SiGe NSs. It is shown that by decorating their surface with H, F, and Cl atoms, H-SiGe, F-SiGe, and Cl-SiGe NSs in FM states are predicted to behave as a semiconductor, half-metal, and metal, respectively. The diverse electronic and magnetic properties define the potential applications of SiGe nanosheets in electronics and spintronics.

Hemangioma treatment with pulsed dye laser-distinct parameters used between neonatal and non-neonatal patients

BACKGROUND

Pulsed dye laser (PDL) treatment remains the standard of care for infantile hemangiomas (IHs). However, the use of PDL to treat IHs in neonates has been hardly reported. In this study, the PDL treatments of IHs between neonatal and non-neonatal patients were retrospectively investigated.

METHODS

All patients diagnosed with hemangiomas were treated by PDL. Their clinical data were collected, and the treatment outcomes and PDL parameters in neonates and non-neonates were analyzed using the Mann-Whitney U-rank test.

RESULTS

All patients reached good or excellent scale in the treatment efficiency assessment. Laser energy used per treatment session was significantly lower in neonatal group than in non-neonatal group (Z = -8.980, P < 0.001). Total laser energy used in neonates was also markedly lower than that in non-neonatal patients (Z = -3.065, P = 0.002). However, treatment session numbers in these two groups were not significantly different (Z = -1.725, P = 0.085). Additionally, we observed that after each treatment, the purpura disappeared faster in neonates (2-4 weeks) than in non-neonatal patients (4-6 weeks), indicating neonates might have greater recovery ability.

CONCLUSIONS

PDL, with distinct parameters, was effective in the treatment of IHs in neonates. After each laser treatment, neonates recovered faster than non-neonatal patients.

Clinical Analysis of the HBV Infection Status of 135 Patients with Diffuse Large B Cell Lymphoma Treated with R-CHOP or CHOP/CHOP-Like Chemotherapy

Objectives

This study aimed to determine the HBV infection status of 135 patients with DLBCL (diffuse large B cell lymphoma), to analyze the overall survival (OS) and progression-free survival (PFS) of the different HBV infection status groups, and to discuss the relationship between HBV serological test results and the prognosis of DLBCL patients.

Methods

A retrospective analysis was performed of the clinical data, HBV serological test results, and PFS/OS of 135 DLBCL patients who were initially diagnosed and treated with more than 3 cycles of an R-CHOP/CHOP/CHOP-like regimen at our center from January 1, 2008 to December 31, 2012.

Results

The patients in the HBV infection group were older at disease onset (≥60 years old) and were more likely to present with stage 3-4 disease compared with the HBV-free group (P = 0.030 and P = 0.025, respectively). Approximately 50% of the patients with an active HBV infection required a reduction in the chemotherapy dose, and 66.7% of the patients in this group received more than 1 line of therapy; these rates were significantly higher than those in the no infection group (P = 0.003 and P = 0.011, respectively). Although HBV infection had no obvious influence on the outcome of first-line therapy, patients with an inactive infection had a higher relapse/progression rate within 3 months after a CR/PR than patients with an active infection (14/20 vs. 1/12, P = 0.001). The PFS at 1 year, 3 years and OS rates at 1 year, 3 years were significantly lower in the active HBV infection group than in the HBV-free group (P = 0.008, P = 0.002, P = 0.004, and P = 0.002, respectively). The PFS rates at 1 year and 3 year in HBV-free group were higher than those in the HBV infection group (80.5% and 52.9% P = 0.001, 78.1% and 44.4% P = 0.002). The lymphoma-related mortality rates were 2.7% in the no infection group, 19.2% in the HBV infection group (P = 0.004), and 28.6% in the active HBV infection group (P = 0.001). Among the patients treated with MabThera, the PFS in the HBV infection group was 11 months in the HBV infection group and 67 months in the infection-free group (P = 0.000). A Cox regression model of PFS revealed that age ≥60 years and HBV infection were independent prognostic factors (age: P = 0.019, HR = 2.002, 95% CI 1.123-3.567; HBV infection: P = 0.026, HR = 0.494, 95% CI 0.265-0.919).

Conclusion

Compared with the patients in HBV-free group, those in the HBV infection group were older at disease onset, and the active infection patients presented with more advanced disease and had a lower PFS at 1, 3 years as well as a lower OS at 3 years. The patients in the inactive infection group had a higher progression/relapse rate within 3 months after a CR/PR than those in the active infection group. HBV infection was an unfavorable factor for PFS in the MabThera group. An age ≥60 years and HBV infection were independent unfavorable prognostic factors for PFS.

Co-immobilization of Pseudomonas stutzeri YHA-13 and Alcaligenes sp. ZGED-12 with polyvinyl alcohol-alginate for removal of nitrogen and phosphorus from synthetic wastewater

Nitrogen (N) and phosphorus (P) are the two main factors causing water eutrophication. Immobilized micro-organisms have been widely studied in N and P removal. However, the effects of various immobilizing conditions on the removal efficiency of N and P using immobilized micro-organism beads (IMOBs) remain unclear. Polyvinyl alcohol (PVA) and alginate, as the two frequently immobilizing-used matrixes, were used for co-immobilizing Pseudomonas stutzeri YHA-13 and Alcaligenes sp. ZGED-12. PVA, alginate and CaCl₂contents, immobilization time and different wet biomass ratios of P. stutzeri to Alcaligenes sp. were conducted to elucidate their roles in and influences on the removal efficiency of N and P from synthetic wastewater. The application potential of IMOBs was estimated as well. Results showed that IMOBs prepared by cross-link of 4% PVA and 2-3% alginate with 5% CaCl₂and saturated boric acid solution for 10-15 min are the best ones in removal of N and P. Though IMOBs containing P. stutzeri and/or Alcaligenes sp. were capable of removal of the two nutrients, the highest removal efficiency was observed when the wet biomass ratio of P. stutzeri to Alcaligenes sp. was adjusted to 2:2. In addition, the IMOBs were of good ability to remove chemical oxygen demand (COD), NO(3)(-), NO(2)(-), NH(4)(+)- N, total nitrogen (TN) and total phosphorus (TP) from artificial wastewater. Of which, micro-organisms immobilized in matrixes were mainly responsible for NO(3)(-) and TP removal. Therefore, P. stutzeri YHA-13 and Alcaligenes sp. ZGED-12 are reliable bioresources to remove N and P from wastewater.

Decreased retinol-binding protein 4 in the sera of patients with end-stage renal disease after kidney transplantation

Retinol-binding protein 4 (RBP4) is a novel adipokine that has been associated with insulin resistance and type 2 diabetes. Patients with end-stage renal disease (ESRD) have very high serum RBP4 levels. However, whether successful kidney transplantation alleviates these elevated serum RBP4 levels is unclear. The serum RBP4 levels of 24 ESRD patients were determined before transplantation and at 1 day, 1 week, and 1 month after kidney transplantation. The control group included 22 healthy subjects. Serum RBP4 concentrations were measured using a commercial kit via the immunologic turbidimetric method, and were related to biomarkers for renal and liver function. The serum RBP4 level of ESRD patients before kidney transplantation (160.8 ± 29.1 mg/L) was approximately 7-fold higher than that of normal controls (22.6 ± 11.0 mg/L; P = 0.000). The serum RBP4 level before transplantation was significantly higher than that at 1 day (65.3 ± 28.4 mg/L), 1 week (48.3 ± 22.9 mg/L), and 1 month after transplantation (53.1 ± 25.5 mg/L; P = 0.000). However, these values were still higher than those of controls (P = 0.000). Univariate regression analysis showed that the percent changes in serum RBP4 concentration before and after kidney transplantation were positively correlated with serum creatinine, blood urea nitrogen, phosphate, and pre-albumin concentrations and negatively correlated with the estimated glomerular filtration rate. The serum RBP4 concentration of patients with ESRD decreased significantly after kidney transplantation; therefore, we found that serum RBP4 concentration was related to renal function.

Dectin-1 gene polymorphism is associated with susceptibility to nonspecific digestive disorders and cytokine expression in rabbits

Dectin-1 plays a critical role in the pathogenesis of intestinal inflammation by recognizing the pathogenic agents and mediating cytokine responses. The objective of this study was to establish the association between dectin-1 polymorphisms and susceptibility to nonspecific digestive disorders (NSDD) and cytokine expression in rabbits. A total of 7 coding SNP were detected in dectin-1 gene. The genetic association between SNP (ss707197675A > G) and susceptibility to NSDD was evaluated using a case-control study (178 cases and 174 controls). The results revealed that the A allele was associated with an increased risk of developing NSDD in rabbits. The AA genotype significantly increased the genetic susceptibility to NSDD with odds ratio of 4.76 (95% confidence interval, 1.92-12.50, P = 0.0002) compared with GG and GA genotypes. We also experimentally induced NSDD in another independent growing rabbit population by feeding a low-fiber diet and subsequently investigated the cytokine mRNA expression. Among the 4 studied cytokines, the expression of interferon-γ, IL-17F, and IL-22 were increased 2.8 to 6.0-fold in AA genotype compared with GG genotype (P < 0.01). The greater IL-17F and IL-22 mRNA expressions indicated a positive correlation with severe intestinal inflammation (P < 0.05). The decreased expression of IL-10 was associated with severe intestinal inflammation (P = 0.006), but IL-10 expression was not influenced by dectin-1 genotype. In conclusion, polymorphism ss707197675 of dectin-1 is related with susceptibility to NSDD and increased expression of proinflammatory cytokines, and dectin-1 could be an important candidate gene associated with NSDD in rabbits.

Development of nanofibrous scaffolds for vascular tissue engineering

Small-diameter vascular grafts can easily lead to thrombosis and intimal hyperplasia. So the rate of the long-term patency is not satisfactory. Scaffolds that can support the growth of cells and remain stable and passable in vivo are in great demand. Vascular scaffolds were fabricated by electrospinning RGD-recombinant spider silk protein (pNSR32), polycaprolactone (PCL) and chitosan (CS). In addition, the cytocompatibility, the stability and the patency of scaffolds in vivo were studied. The results demonstrated that Sprague-Dawley rat aortic endothelial cells (SDRAECs) could highly enhanced adhesion and proliferation, together with increasing stress of fiber formation, and intensive biological function (the expression of PECAM-1 and vWF, the secretion of NO), in the pNSR32/PCL/CS scaffolds, compared with in the pNSR32/PCL and PCL scaffolds. The cell cycle studies of SDRAECs also revealed that the scaffolds promoted the cells to enter the stage of divisional proliferation. Furthermore, pNSR32/PCL/CS scaffolds could support the growth of cells under physiologic conditions and are able to maintain the structural integrity and patency for at least 8 weeks in a SD rat abdominal aortic defect model.

[Isolation and characterization of the salt-tolerant aerobic denitrifying bacterial strain A-13]

OBJECTIVE

This study is aimed to isolate and identify an aerobic denitrifying bacterium with high ability for nitrogen removing, and optimize its growing and denitrifying conditions to obtain the theory basis for controlling the eutrophic artificial lake.

METHODS

Aerobic denitrifying bacterium strain A-13 was screened by denitrifying medium. Strain identification was carried out through morphological, biochemical and physiological characteristics, 16S rRNA gene and periplasm nitrate reductase gene analysis. The optimal pH, temperature, carbon source, dissolved oxygen (DO), inoculum ratio were tested as well.

RESULTS

Strain A-13 isolated from a drain outlet located in Gaoqi village, Shangjie town, Minhou county, Fuzhou, China, was a member of Pseudomonas stutzeri and its DNA sequence was most closely related to Pseudomonas stutzeri DSM 50283. The optimal conditions for its growth and denitrification were followed as: pH 6.5, 33 degrees C, 150 r/min, 5% inoculum rate and the best carbon source was sodium succinate. Under these conditions, the maximum removal capacity for NO3- was approximately 1900 mg/L. The strain could grow well in the medium with high salinity (10%) and could also use NO2- and NH(4+)-H as the sole nitrogen source.

CONCLUSION

The isolated P. stutzeri, A-13 is a potential strain to treat wastewater with high salinity and/or eutrophication.

Study on characteristics of in vitro culture and intracellular transduction of exogenous proteins in fibroblast cell line of Liaoning cashmere goat

Establishment of fibroblast cell lines of endangered goat breeds and research on the gene or protein functions based on the cells made a significant contribution to the conservation and utilization of genetic resources. In this study, a fibroblast cell line of Liaoning cashmere goat, frozen in 174 cryovials with 5 × 10(6) cells each, was successfully established from 60 goats ear marginal tissues using explant culture and cryopreservation techniques. Biological analysis of in vitro cultured cell line showed that, the cells were morphologically consistent with fibroblasts; the average viability of the cells was 94.9 % before freezing and 90.1 % after thawing; the growth process of cells was consisted of a lag phase, a logarithmic phase and a plateau phase; cell population doubling time was 65.5 h; more than 90 % of cells were diploid prior to the 6th generation; Neither microbial contamination nor cross-contamination was detected. To determine cell permeability, intracellular path and stability of exogenous proteins during the transduction, a TAT protein transduction domain was fused to the C-terminus of enhanced green fluorescent protein, the established fibroblast cell line was treated with the purified exogenous proteins at various concentrations by adding them to the cell culture media for 1-24 h and assayed cell morphology and protein presence, it was found that the purified exogenous proteins readily entered cells at a concentration of 0.1 mg/ml within 1.5 h and some of them could translocate into nucleus, moreover, the exogenous proteins appeared to be stable inside cells for up to 24 h.

Cloning and prokaryotic expression of rat homolog of Serpina3n and its expression change during liver regeneration

A strikingly upregulated expressed sequence tag was screened from regenerating rat liver at 8 h in a 0-4-8-12 h short-interval successive partial hepatectomy model from a previous study. In the present study, a full-length open reading frame (ORF) corresponding to this expressed sequence tag was predicted through electronic cloning and was subsequently cloned from an 8-h rat regenerating liver and deposited in GenBank (accession No. HM448398). Sequence analysis of HM448398 and the predicted ORF revealed that the two ORFs may be different transcripts of a gene. The sequence of HM448398 was highly homologous to that of rat Serpina3n, suggesting that it may be a homolog of Serpina3n. The pGEX-2TK prokaryotic expression vector for this ORF was constructed, and the result of sodium dodecyl sulfate polyacrylamide gel electrophoresis manifested that the recombinant expression vector could express the glutathione-S-transferase-fused rat homolog of Serpina3n in an insoluble form in BL21. The target fusion protein was purified with affinity chromatography and was used as antigen to immunize rabbits for the production of polyclonal antibodies. Immunohistochemistry and real-time reverse transcription polymerase chain reaction analysis revealed that the gene was highly expressed in the priming and termination phases of liver regeneration. These findings lay a solid foundation for further study of roles of HM448398 using knock-in and RNA interference methods during liver regeneration.

Low-energy structures of clusters supported on metal fcc(110) surfaces

The low-energy structures (LESs) of adatom clusters on a series of metal face-centered cubic (fcc) (110) surfaces are systematically studied by the genetic algorithm, and a simplified model based on the atomic interactions is developed to explain the LESs. Two different kinds of LES group mainly caused by the different next nearest-neighbor (NNN) adatom-adatom interaction are distinguished, although the NNN atomic interaction is much weaker than the nearest-neighbor interaction. For a repulsive NNN atomic interaction, only the linear chain is included in the LES group. However, for an attractive one, type of structure in the LES group is various and replace gradually one by one with cluster size increasing. Based on our model, we also predict the shape feature of the large cluster which is found to be related closely to the ratio of NN and NNN bond energies, and discuss the surface reconstruction in the view of atomic interaction. The results are in accordance with the experimental observations.PACS: 68.43.Hn; 68.43.Fg.

Effects of Sophy β-glucan on growth performance, carcass traits, meat composition, and immunological responses of Peking ducks

The response of Peking ducks to supplements of Sophy β-glucan was studied. A total of 160 healthy 1-d-old mixed-sex ducklings were randomly allocated to 3 groups: Sophy β-glucan (n = 80), bacitracin zinc (n = 40), and control (n = 40), which received the same antibiotics-deficient diet supplemented with 1% β-glucan, 5% bacitracin zinc, or nothing, respectively. During 2 mo of the study, growth performance, carcass composition, and meat quality of Peking ducks were evaluated. Additionally, a separate immunological study was conducted with a total of 105 healthy male Peking ducks in 7 groups (n = 15) and immunized with different doses of β-glucan (0, 0.5, 2.5, 12.5, and 62.5 μg/duck) and BSA (200 μg/duck). Blood was taken for detection of anti-BSA-IgG antibody and peripheral blood mononuclear cells proliferation assays. Groups subjected to different dietary treatments showed almost no differences in growth performance and slaughter traits except breast muscle percentage and intestinal length. These 2 indicators were significantly higher in the bacitracin zinc group than in the control and β-glucan groups (P < 0.05). Similarly, chemical compositions, fatty acids, and amino acids of breast muscle were not significantly influenced by the diet. Ducks immunized with Sophy β-glucan did not have enhanced level of anti-BSA-IgG antibodies but had significant peripheral blood mononuclear cells proliferation compared with unchallenged ducks (P < 0.01). With an increase in the glucan concentration, the proliferative responses approximately linearly increased. These findings indicate that 1% Sophy glucan did not improve duck growth performance, carcass composition, and meat quality significantly under the conditions of the present experiment and mainly had regulatory or enhancing properties on poultry nonspecific cellular immunity.

Equivalence condition for the canonical and microcanonical ensembles in coupled spin systems

It is typically assumed, without justification, that a weak coupling between a system and a bath is a necessary condition for the equivalence of a canonical ensemble and a microcanonical ensemble. For instance, in a canonical ensemble, temperature emerges if the system and the bath are uncoupled or weakly coupled. We investigate the validity region of this weak-coupling approximation, using a coupled composite-spin system. Our results show that the spin coupling strength can be as large as the level spacing of the system, indicating that the weak-coupling approximation has a much wider region of validity than usually expected.

Effect of recombinant Panton–Valentine leukocidin in vitro on apoptosis and cytokine production of human alveolar macrophages

Panton–Valentine leukocidin (PVL) is associated with rare cases of necrotizing pneumonia that occur in otherwise healthy individuals. Human alveolar macrophages (HAMs) are major effector cells in host defense against infections. However, the impact of PVL on HAMs is uncertain. We evaluated the role of PVL in cytotoxicity and production of inflammatory cytokines secreted by HAMs. HAMs were purified from bronchoalveolar lavage fluid. Recombinant PVL (rPVL) was used in the study to interfere with HAM apoptosis and cytokine production in vitro. Hoechst 33342 fluorescence staining, transmission electron microscopy examination, and flow cytometry indicated that rPVL (10 nmol/L) treatment resulted in HAMs with markedly apoptotic characteristics, and HAMs treated with rPVL at 100 nmol/L showed clear indication of necrosis. A treatment of rPVL at 10 nmol/L elicited the secretion of IL-10 by HAMs relative to untreated control cells, but there was a slight decrease in the constitutive secretion of tumor necrosis factor (TNF)-α. Our results indicate that PVL-treated samples decreased HAM viability, leading to apoptosis at low concentrations and necrosis at high concentrations. In addition, PVL-treated cells released increased amounts of IL-10 and decreased amounts of TNF-α under apoptosis-inducing concentrations. Therefore, we speculated that PVL could play a negative role in HAM function at lower concentrations.

Establishment and cryopreservation of a fibroblast cell line derived from Bengal tiger (Panthera tigris tigris)

The Bengal tiger ear marginal tissue fibroblasts cell line (BTF22), containing 157 tubes of frozen cells, was successfully established by using primary explants technique and cell cryoconservation technology. Biological analysis showed that the population doubling time (PDT) for revival cells was approximately 28 h. Measurement of LDH and MDH isoenzymes showed no cross-contamination among the cells. Karyotyping showed that the frequency of cells with chromosome number 2n = 38 was 90.6-92.2%. Tests for bacteria, fungi, viruses and mycoplasma were negative. Plasmids encoding the fluorescent proteins pEGFP-N3, pEGFP-C1, pECFP-N1, pECFP-mito, pDsRed1-N1, and pEYFP-N1 were transfected into cells to study exogenous gene expression in the cells. The plasmid transfection efficiency was between 4.4% and 31.9%. Every index of the BTF22 cell line meets all the standard quality controls of American type Culture Collection (ATCC). Not only has the germline of this important Bengal tiger species been preserved at the cell level, but also valuable material had been provided for genome, postgenome and somacloning research. Moreover, the establishment of this technical platform would provide both technical and theoretical support for storing the genetic resources of other animals and poultry at the cell level.

Early embryonic blood cells collect antigens and induce immunotolerance in the hatched chicken

Earlier experimental data in our laboratory showed that introduction of an exogenous protein into early chicken embryonic blood leads to immunotolerance of hatched chicken to that protein. However, the underlying mechanism is yet unknown. In the present study, we show that the blood cells collecting circulating antigen might contribute to the establishment of immunotolerance. In this experiment, most of the chicken embryo blood cells took up injected fluorescein isothiocyanate-BSA at approximately embryonic d 3. At the same stage, 1 microL of embryo blood was taken out and incubated with BSA. After being loaded with BSA in vitro and washed, these cells were injected back into the original embryo. The BSA-specific lymphocytes were depleted in chickens whose early embryo cells had been loaded with BSA, as evidenced by a significant decrease in anti-BSA antibody after challenge with BSA when the chickens were 3 wk old. In addition, by direct injection of BSA to embryonic d 3 embryo blood, the hatched chickens had decreased amounts of anti-trinitrophenol antibody after the chickens were challenged with trinitrophenol-BSA, indicating that the helper function of BSA-specific T cells was impaired. In conclusion, these observations suggest that some early embryo blood cells possibly collect and store antigen for the establishment of self-tolerance before the maturation of B and T cells.

Statistical model for small clusters transforming from one isomer to another

Based on the fact that the kinetic energy of one atom in small cluster still obeys the Boltzmann distribution, a statistical model is developed to predict the time consumed by a small cluster transforming from one isomer to another and is tested by vast molecular dynamics simulations of C(12) isomers transformation in helium gas at high temperatures (2000-3500 K). Extrapolating the model to lower temperatures, we found that the time for the most probable isomer of C(12) formed at 2500 K turning into the most stable one is more than 10(12) years at room temperature.

[Pulmonary nocardiosis in immunocompromised host: report of 2 cases and review of the literature]

OBJECTIVE

To investigate the clinical, imaging and pathogenic features of pulmonary nocardiosis and the drug resistance of Nocardia.

METHODS

The clinical and radiological data of 2 cases of pulmonary nocardiosis in this hospital were presented, and 32 cases reported in the Chinese literature since 1982 were reviewed.

RESULTS

Among the 34 cases of Nocardia infections, there were 26 cases of pulmonary nocardiosis, and 4 of whom died. Multiple organ infection occurred in 11 patients, including 7 with pulmonary and skin infections, 3 with pulmonary, skin and intracranial infections, and 1 with pulmonary and intracranial infections. All patients with pulmonary nocardiosis had cough. Of the 34 cases, 27 had fever, including intermittent fever in 5, and sustained fever in 22 cases. Of the 11 cases of pulmonary nocardiosis complicated with skin or intracranial dissemination, 8 patients were immunocompromised and 3 were immunocompetent (chi(2) = 2.08, P > 0.05). Three cases died in the immunocompromised group and 1 died in the immunocompetent group. Nocardia asteroides was identified in 14 cases, Nocardia brasiliensis in 4 cases, and the other 8 were not classified. In the patients with complicated skin or intracranial infections, 8 were caused by Nocardia asteroids, and 2 were caused by Nocardia brasiliensis. Chest X-ray or CT imaging of the lungs showed pleural effusion in 8, masses in 7, infiltrates in 6, cavities in 6, and nodular lesions in 5 cases. Antimicrobial susceptibility testing showed that Nocardia was sensitive to sulfonamide, amikacin, cefotaxime, ceftriaxone, minocycline, fluoroquinolones, and linezolid.

CONCLUSIONS

Immunosuppression is the most important predisposing factor for pulmonary nocardiosis. The most common pathogenic bacterium is Nocardia asteroids, which is frequently associated with disseminated lesions. The radiographic abnormalities of the lung show pleural effusion, masses, infiltration or cavity. With the increasing rate of resistance of Nocardia to the sulfonamide, the combination of antibiotic regimen according to susceptibility testing needs to be considered. Poor outcome is mostly found in immunocompromised hosts.

Stepwise regression analysis of the determinants of blood tacrolimus concentrations in Chinese patients with liver transplant

Tacrolimus (FK506) is one of the immunosuppressive drugs used effectively to prevent allograft rejection after liver transplantation. Narrow therapeutic range and individual variance in pharmacokinetics make it difficult to establish a fixed dosage for all patients. Genetic polymorphism in drug metabolizing enzymes and in transporters may influence tacrolimus exposure. A stepwise regression analysis was used to analyze the relationship between blood concentrations of tacrolimus (54 blood samples at the day of 1 week, 2 week and one month after liver transplantation) and genetic & non-genetic factors in 18 Chinese liver transplant patients. The equation of multiple stepwise regression was: Y (tacrolimus' blood concentration) = 34.534 - 0.247 (age) - 0.510 (weight) + 1.688 (dose) + 6.876 (recipient's CYP3A5 genotype) - 3.097 (donor's CYP3A5 genotype), P < 0.01. The factors impacting patient's tacrolimus blood concentrations in a descending order are weight, recipient's CYP3A5 genotype, dose, age, donor's CYP3A5 genotype. Among those, patient's weight and recipient's CYP3A5 genotype could significantly impact the blood concentration of tacrolimus. The influence of recipient's CYP3A5 gene polymorphism is much more obvious than that of donor's. Neither donor's nor recipient's MDR1 genetic polymorphisms were correlated with the blood concentration of tacrolimus.

[The effect of recombinant panton-valentine leukocidin on the production of cytokines by human alveolar macrophages]

OBJECTIVE

To investigate the effect of recombinant panton-valentine leukocidin (rPVL) on the regulation of human alveolar macrophage CD14 and IL-10 and TNF-alpha.

METHODS

Human alveolar macrophages (AM) were purified and cultured from bronchoalveolar lavage fluid. Each sample was divided into groups according to different concentrations and exposure times of rPVL. Semi-quantitative RT-PCR was used to evaluate the CD14 mRNA levels and Double-antibody-sandwich-ELISA was used to measure the IL-10 and TNF-alpha levels in AM cultures.

RESULTS

CD14 mRNA decreased after rPVL treatment in time-and concentration dependent manners. There were no statistically significant differences in CD14 mRNA among the blank control groups (F = 1.708, P > 0.05). CD14 mRNA in the T6N10 group and the T6N100 group( T = time in hours, N = concentration of rPVL/nmol/L) decreased as compared to the T6N0 group (t = 4.132, 6.818, both P < 0.001), and that in the T24N10 group and the T24N100 group also decreased as compared to the T24N0 group (t = 7.401, 11.415, both P < 0.001), indicating that the expression of CD14 was downregulated by rPVL treatment. There were also statistically significant differences in CD14 mRNA between T6N10 and T24N10 groups, T6N100 and T24N100 groups (t = 4.692, 6.019, both P < 0.001), T6N10 and T6N100 groups, T24N10 and T24N100 groups (t = 2.686, 4.014, P < 0.01 respectively), indicating that the expression of CD14 decreased as the treatment time and the concentration of rPVL increased. The IL-10 concentrations of the T24N10 and T24N100 groups increased as compared to the T24N0 group (t = 4.036, 3.941, both P < 0.01) in time-dependent and concentration-dependent manners with rPVL treatment. The TNF-alpha concentration of the T24N10 group decreased while that of the T24N100 group increased as compared to the T24N0 group (t = 2. 824, 8. 468, both P < 0.01, respectively), indicating that a lower concentration of rPVL inhibited TNF-alpha release while a higher concentration of rPVL induced release of TNF-alpha.

CONCLUSION

The results suggest that rPVL could reduce the expression of CD14 and induce disordered release of anti-inflammatory and proinflammatory cytokines by AMs, which may be one of the important mechanisms underlying the high mortality of infection with PVL-positive Staphylococcus aureus.

Pulmonary cryptococcosis in non-AIDS patients

PURPOSE

To clarify the clinical features and imaging characteristics of non-AIDS patients with pulmonary cryptococcosis.

METHODS

We retrospectively collected 15 HIV-negative patients with pathology-proved pulmonary cryptococcosis from Sep 1992 to Jan 2008. Their medical records and radiological data were reviewed and analyzed.

RESULTS

Only one patient was asymptomatic.Thirteen patients were immunocompetent and two were immunosuppressed. Three patients had associated cryptococcosis meningitis. The most common radiographic abnormalities were multiple pulmonary nodules or masses, seen in 8 and 5 cases of patients respectively. 14 patients received specific therapy for Cryptococcus neoformans. Two patients died. In the 11 patients with isolated pulmonary cryptococcosis, treatment consisted of fluconazole alone (n=7), in combination with amphotericin B (n=2), and both 5-flucytosine and amphotericin B (n=2). For the other 2 patients with cryptococcosis meningitis, one was treated with amphotericin B alone and the other with fluconazole combined with amphotericin B and 5-flucytosine.

CONCLUSIONS

Non-AIDS patients might also susceptible to cryptococcosis infection. Histological examination is the principal method of diagnosis. The most common CT findings are solitary or multiple nodules with or without cavitation in the subpleural areas of the lung.

[Research progress of neural stem cells signal transduction pathway]

OBJECTIVE

To summarize Notch, basic helix-loop-helix (bHLH) and Wnt gene signal transduction pathways in the process of differentiation and development of neural stem cells.

METHODS

The literature on the gene signal transduction pathway in the process of differentiation and development of neural stem cells was searched and then summarized and analyzed.

RESULTS

The formation of Nervous System resulted from common actions of multi-signal transduction pathways. There may exist a fixed threshold in the complicated selective system among Notch, bHLH and Wnt gene signal transduction pathways.

CONCLUSION

At present, the specific gene signal transduction pathway of multiplication and differentiation of neural stem cells is still unclear.

Diffusion characteristics of a T-type microchannel with different configurations and inlet angles

A series of symmetrical and asymmetrical microfluidic T-sensors with different inlet angles were fabricated to study the mixing characteristics of a T-type microstructure for generating concentration gradient. Computational fluid dynamics (CFD) simulations showed that the concentration gradient, transition zone and diffusion length were different for various configurations and inlet angles. Quick mix and sharp concentration gradient occurred in the asymmetrical structure with large inlet angle. The observed concentration gradients in the fabricated microchannel were consistent with the theoretical prediction. In this microstructure, stagnant zone and z-direction diffusion also affected the concentration gradient. Based on the simulation results, the microfluidic structure was optimized to generate desired concentration gradient for a cell-based study.

Frequency of CYP2D6*10 and *14 alleles and their influence on the metabolic activity of CYP2D6 in a healthy Chinese population

To study the frequency of CYP2D6(*)10 and (*)14 alleles in a healthy Chinese population, and the influence of these two alleles on the metabolic activity of CYP2D6. CYP2D6(*)10 and (*)14 genotypes of 295 healthy Chinese subjects were determined using a tetra-primer method and allele-specific amplification. CYP2D6 phenotypes of 131 subjects were determined using dextramethorphan as probe drug. There were 10 subjects with a (*)14 allele, including one homozygous for (*)14. The gene frequency of (*)10 and (*)14 alleles were 55.8 and 1.8%, respectively. The metabolic ratio (MR) of dextramethorphan in 131 subjects was 0.032+/-0.106. The MR of (*)1/(*)1, (*)1/(*)10, (*)10/(*)10, (*)1/(*)14, (*)10/(*)14, and (*)14/(*)14 groups were 0.007+/-0.012, 0.009+/-0.010, 0.042+/-0.029, 0.093, 0.11, and 1.186, respectively. The MR of subjects with (*)14 allele was higher than those of (*)1/(*)1, (*)1/(*)10, or (*)10/(*)10 groups (P<0.001). The CYP2D6(*)10 and (*)14 alleles have substantial impact on the metabolic activity of CYP2D6, and the CYP2D6(*)14 allele may be the cause of the poor metabolizer phenotype in Chinese subjects.

Dipolar effect in coherent spin mixing of two atoms in a single optical lattice site

We show that atomic dipolar effects are detectable in the system that recently demonstrated two-atom coherent spin dynamics within individual lattice sites of a Mott state. Based on a two-state approximation for the two-atom internal states and relying on a variational approach, we have estimated the spin dipolar effect. Despite the absolute weakness of the dipole-dipole interaction, it is shown that it leads to experimentally observable effects in the spin mixing dynamics.

Dynamical instability and domain formation in a spin-1 Bose-Einstein condensate

We interpret the recently observed spatial domain formation in spin-1 atomic condensates as a result of dynamical instability. Within the mean field theory, a homogeneous condensate is dynamically unstable (stable) for ferromagnetic (antiferromagnetic) atomic interactions. We find that this dynamical instability naturally leads to spontaneous domain formation as observed in several recent experiments for condensates with rather small numbers of atoms. For trapped condensates, our numerical simulations compare quantitatively to the experimental results, thus largely confirming the physical insight from our analysis of the homogeneous case.

[Comparison of two score models in predicting prognosis and renal outcome in acute renal failure]

OBJECTIVE

To compare the value of ATN-ISI (acute tubular necrosis-individual severity index) and APACHE II (acute physiology and chronic health evaluation) score models in predicting mortality and renal outcome in patients with acute renal failure (ARF).

METHODS

422 in-hospital patients with ARF were retrospectively analysed, the value in predicting prognosis and renal outcome of these two score models was compared. Renal outcome was observed three times, i.e. >or= 30 days, >or= 45 days and >or= 60 days after the occurrence of ARF and discriminant analysis was used in the study.

RESULTS

The scores of the two models both correlated significantly with the mortality of patients with ARF. When ATN-ISI scores were >or= 0.85, the mortality was 100% and it was the same with APACHE II when the scores were >or= 35. The areas under ROC curve of APACHE II and ATN-ISI were 0.817 +/- 0.021 and 0.880 +/- 0.018 respectively, suggesting good model discriminantion. For the correctly classificated rate of renal outcome, ATN-ISI was better than APACHE II at any time. When ATN-ISI scores were >or= 0.75, patients were dialysis dependent. When the scores were >or= 0.58 but less than 0.75, the patient's renal function did not recover but was not dialysis dependent; when the scores were < 0.58, the patients's renal function would recover. When APACHE II scores were >or= 26, patients were dialysis dependent. There was no cut-off score point to separate renal function recovery from renal dysfunction. However, when APACHE II scores were <or= 22, 19.6% of the patients had renal dysfunction and 80.4% of them had renal function recovered.

CONCLUSION

Both the score models are of value in predicting mortality and renal outcome in patients with ARF. ATN-ISI score model was better than APACHE II.

[Development of the chip system for measurement of red blood cell rheology]

We have developed a novel silicon microchannel system for the research of the red blood cell rheology and deformation. Recurring to many kinds of information technologies and advanced test means such as the electronic microscope, the image acquisition system and the computer processing system and by using the up-to-date Micro Electro Mechanical System (MEMS) technology, a new measuring system of red bood cell deformation is designed based on the chip and a model using the silicon microchannel to simulate capillary vessel network. It provides a real-time collection and anaysis of data which include image, speed, flow parameter, and so on. It provides printing, storage of the analysis results and patients' database management.

Field assessment of nanoscale bimetallic particles for groundwater treatment

A field demonstration was performed in which nanoscale bimetallic (Fe/Pd) particles were gravity-fed into groundwater contaminated bytrichloroethene and other chlorinated aliphatic hydrocarbons at a manufacturing site. With diameters on the order of 100-200 nm, the nanoparticles are uniquely suited to rapidly degrade redox-amenable contaminants and for optimal subsurface delivery and dispersion. Approximately 1.7 kg of the nanoparticles was fed into the test area over a 2-day period, resulting in minimal clogging of the injection well. The test area was located within a well-characterized region of the contaminant plume and included an injection well and three piezometer couplets spaced 1.5 m apart. Despite the low nanoparticle dosage, trichloroethene reduction efficiencies of up to 96% were observed over a 4-week monitoring period with the highest values observed at the injection well and adjacent piezometers. Data from the field assessment were consistent with the results of pre-injection laboratory studies, which showed rapid dechlorination of target chlorinated compounds accompanied by a sharp decrease of standard oxidation potential and an increase in pH.

Decreased +gz tolerance following lower body positive pressure: simulated push-pull effect

OBJECTIVE

The purpose of this study was to attempt to simulate the push-pull maneuver on a single-axis human centrifuge using lower body positive pressure (LBPP), and to observe the effect of the push-pull maneuver on +Gz tolerance.

METHODS

Six volunteers participated in the experiment. They were subjected to LBPP of up to 300 mm Hg for 1 min. Blood pressure (BP) and heart rate (HR) were monitored before, during and after LBPP. Immediately after LBPP, +Gz tolerance was measured on a human centrifuge.

RESULTS

During LBPP, systolic BP (SBP) and diastolic BP (DBP) increased significantly, mean arterial pressure (MAP) increased but not significantly, and HR decreased significantly. After LBPP, SBP and MAP decreased significantly, while DBP and HR decreased but not significantly. In all subjects, +Gz tolerance decreased after LBPP. The decreased value was 0.70 +/- 0.06 G, maximum 1.0 G and minimum 0.5 G.

CONCLUSION

The push-pull maneuver can be simulated on a single-axis human centrifuge using LBPP. The physiologic effects of LBPP were similar to those of -Gz. We observed that +Gz tolerance decreased after LBPP, which confirmed the push-pull effect from the experiment.

[Appraisal and analysis of heat removing characteristic of liquid cooling garment using thermal manikin]

OBJECTIVE

To analyze the relation of the design parameters and appraise the heat removing characteristic of liquid cooling garment (LCG) using thermal manikin.

METHOD

To appraise the design of LCG, the thermal manikin wearing LCG and heat insulation garment was put in the temperature cabin, then the inlet and outlet temperature of cooling liquid in the LCG were measured and the heat removed was calculated.

RESULT

The relationship between the design parameters and heat removed, and also that between the design parameters and temperature ratio efficiency were found. And the heat removed was calculated. It provided a reasonable basis for appraisal of LCG.

CONCLUSION

The design of the LCG for the EVA space suit was found to be reasonable. The flow rate regulation range was too narrow, and the change of heat removing capacity depended on the change of inlet temperature.

Synthesis and characterization of CdIn(2)S(4) nanorods by converting CdS nanorods via the hydrothermal route

The ternary semiconductor CdIn(2)S(4) nanorods were synthesized by a method based on CdS nanorods via the hydrothermal route, in which CdS nanorods were converted by reaction with InCl(3) and thiourea in aqueous solution. Transmission electron microscopy (TEM) images revealed that the typical sizes of the CdIn(2)S(4) nanorods were 10-30 nm in diameter and 200-1000 nm in length. X-ray photoelectron spectra (XPS) analysis of the surface stoichiometry (CdIn(2.03)S(4.15)) and room-temperature Raman spectrum (RS) were recorded. The influences of reaction temperature, time, and sulfur sources on the formation for CdIn(2)S(4) nanorods were investigated. A possible formation mechanism of the CdIn(2)S(4) nanorods was also proposed.

[Data analysis of 492 times centrifuge examination]

Objective. To sum up the experiences and to find the regularity of centrifuge examinations. Method. The data of nine years of centrifuge examination (from 1988 to 1996) of pilots who suffered from black out or LOC frequently were analyzed. Result. There were totally 492 times centrifuge examinations. First centrifuge examination included 229 pilots, 49 qualified, 180 unqualified. Second centrifuge examination included 263 pilots, 50 qualified, 213 unqualified. The pilots were all male. The average age of first centrifuge examination was 29.27 +/- 4.87 years. Average flying time was 1015.24 +/- 131.89 h. 68.7% of their plane was JJ-6 or above. Conclusion. Most pilots undergoing centrifuge examination these nine years were 26-35 year old, and had flown for 601-1200 h. The planes they flew are mostly high-performance fighter aircraft. Close attention must be paid to pilots under similar condition by the flight surgeon. It is recommended that the special equipment of G-tolerance training should be added to the fighter aircraft units.

Cloning and characterization of a new member of the T-box gene family

The T-box is a strongly conserved protein domain, 174 to 186 amino acids in length, that binds DNA. Many genes from many species have been shown to encode T-box domain-containing proteins. Here we report the cloning and characterization of a novel T-box gene, TBX21. The human cDNA contains an open reading frame encoding a 535-amino-acid protein with a predicted molecular mass of 58.3 kDa. Except for the T-box sequence, database searches revealed no significant homology to any known sequences at the nucleotide or protein level. In addition to the human cDNA sequence, we report the cDNA sequence of the murine homologue, the structure and organization of the murine Tbx21 gene, and its localization to mouse chromosome 11. TBX21 expression was detected in peripheral blood lymphocytes, spleen, lung, and natural killer cells.