Antimicrobial resistance of Staphylococcus aureus isolated from bovine mastitis in China

Mastitis is one of the largest production concerns in the dairy industry worldwide. Mastitis caused by Staphylococcus aureus is a major concern to the dairy industry because of its resistance to antibiotic treatment. In this report, the results of antibiotic susceptibility test, carried out on 236 Staphylococcus aureus isolated from milk samples which were collected from cases of mastitis in cow herds of China, are presented. The regions and number of isolates include Inner Mongolia (112), Hebei (58) and Heilongjiang (66). Susceptibility to ampicillin, penicillin G, amoxicillin, piperacillin, cephalexin, cephazolin, cefotaxime, ceftazidime, cefoxitin, SMZ-TMP, gentamycin, kanamycin, norfloxacin, ciprofloxacin, ofloxacin, furaxone, torlamician, roxithromycin, clindamycin and vancomycin was determined by the disc diffusion method. Antibiotic susceptibility testing showed 87.30% (206 of 236) isolates were resistant to penicillin G. This result compares with the reports from other countries; the overall level of resistance was generally high for all antimicrobial agents tested.

Precision genetics for complex objectives in animal agriculture

Indirect modification of animal genomes by interspecific hybridization, cross-breeding, and selection has produced an enormous spectrum of phenotypic diversity over more than 10,000 yr of animal domestication. Using these established technologies, the farming community has successfully increased the yield and efficiency of production in most agricultural species while utilizing land resources that are often unsuitable for other agricultural purposes. Moving forward, animal well-being and agricultural sustainability are moral and economic priorities of consumers and producers alike. Therefore, these considerations will be included in any strategy designed to meet the challenges produced by global climate change and an expanding world population. Improvements in the efficiency and precision of genetic technologies will enable a timely response to meet the multifaceted food requirements of a rapidly increasing world population.

Abnormal high expression of B-cell activating factor belonging to the TNF superfamily (BAFF) associated with long-term outcome in kidney transplant recipients

B-cell activating factor belonging to the tumor necrosis factor superfamily (BAFF) is a critical regulator of B-cell maturation and survival. We investigated the expression of BAFF in peripheral blood sample from kidney transplant recipients. Results of flow cytometry showed that at 5 years or more posttransplantation, cell-surface BAFF was significantly expressed on peripheral CD3+ T lymphocytes kidney transplant recipients in compared with other groups (P < .05). BAFF expression was noted on CD4+ and CD8+ T cells. The BAFF messenger RNA level in peripheral mononuclear cells was consistent with the protein level. However, the serum soluble BAFF level varied among individuals in each group. Stratified by renal function, the cell-surface BAFF level was significantly higher in recipients with abnormal renal function compared with those with normal renal function (P < .05). Enzyme-linked immunosorbent assay results showed that expression level of cell-surface BAFF significantly correlated with panel reactive antibody. These results indicate that BAFF may be involved in the development of graft loss.

Family-based association analysis of S100A8 genetic polymorphisms with aggressive periodontitis

BACKGROUND AND OBJECTIVE

It is known that S100A8, a member of the S100 calcium-binding protein family, is associated with inflammatory diseases, including periodontitis. Our previous population-based study found an association between two polymorphisms, rs3795391 (A > G) and rs3806232 (A > G), in the upstream region of the S100A8 gene and aggressive periodontitis (AgP) in Chinese people. Based on those results, this investigation set out to analyze and corroborate whether the association also exists within families.

MATERIAL AND METHODS

Two hundred and four subjects from 73 nuclear families were recruited. All probands and their relatives were diagnosed according to the 1999 classification of periodontal diseases. Anticoagulated peripheral blood samples were collected from all the subjects, and DNA was extracted. The two single nucleotide polymorphisms (SNPs; rs3795391 and rs3806232) were detected and analyzed by standard polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) assay. Analysis of genotype/allele was performed by Family-Based Association Test (FBAT) software ( http://www.biostat.harvard.edu/~fbat/default.html).

RESULTS

There was a statistically significant association of the SNP rs3795391 with AgP in the additive genetic model (chi(2) = 3.9836, d.f. = 1, p = 0.0459). Allele A showed significantly preferential transmission to the AgP affected individuals (Z = 1.996, p = 0.0459). The other SNP, rs3806232, showed no significant results in all models.

CONCLUSIONS

This family-based association study supports the previous findings that SNP rs3795391 (A > G) of the S100A8 gene might contribute to AgP susceptibility. This is, to our knowledge, the first investigation about AgP using FBAT in genetic analysis.

In vitro culture and differentiation of buffalo (Bubalus bubalis) spermatogonia

The objective of this study was to develop a culture system which could support buffalo spermatogonia differentiation into spermatids in vitro. Testes from 3- to 5-month-old buffaloes were decapsulated and seminiferous tubules were enzymatically dissociated to recover spermatogonia and sertoli cells. The cells were cultured in modified Dulbecco modified Eagle medium supplemented with different concentrations of foetal bovine serum, retinol, testosterone for 2 months at 37 degrees C. Spermatogonia and sertoli cells were identified with an antibody against c-kit or GATA4, respectively. The viability of spermatogonia in the media supplemented with different concentrations of serum was all significantly higher (p < 0.05) compared with that in the medium without serum. A-paired or A-aligned spermatogonia and spermatogonial colonies (AP-positive) were observed after 7-10 days of culture and spermatid-like cells with a flagellum (6-8 microm) appeared after 30 days of culture. For cultured conditions, retinol could not significantly promote the formation of spermatid-like cells (p > 0.05), whereas supplementation of testosterone could significantly promote (p < 0.05) the formation of spermatid-like cells after 41 days of culture. The expression of the spermatid-specific marker gene (PRM2) was identified after 30 days of culture by RT-PCR. Yet, the transition protein 1 (TP1, a haploid makers) was not detected. Meanwhile, spermatids developed in vitro were also confirmed by Raman spectroscopy. These results suggest that buffalo spermatogonia could differentiate into spermatids in vitro based on the analysis of their morphology, PRM2 expression and Raman spectroscopy. Yet, the normality of the spermatid-like cells was not supported by TP1 expression.

Elevation of C-reactive protein and interleukin-6 in plasma of patients with aggressive periodontitis

BACKGROUND AND OBJECTIVE

Systemic levels of C-reactive protein and interleukin-6 have been reported to be elevated in patients with periodontitis compared with periodontally healthy individuals. Most studies included patients with chronic periodontitis and comprised predominantly Caucasians. The aim of this study was to determine the relative levels of C-reactive protein and interleukin-6 in plasma of patients with aggressive periodontitis in China and to examine the relationships between these two inflammatory mediators and clinical parameters, peripheral blood cells and protein variables.

MATERIAL AND METHODS

Plasma samples were collected from 84 patients with aggressive periodontitis and from 65 control subjects. Periodontal examination consisted of taking probing depth and attachment loss measurements. The levels of plasma C-reactive protein and interleukin-6 were determined using enzyme-linked immunosorbent assays.

RESULTS

The levels of plasma C-reactive protein in patients with aggressive periodontitis were significantly higher than those in control subjects (1.87 vs. 0.52 mg/L). The level of plasma interleukin-6 in patients with aggressive periodontitis was 1.20 pg/mL, higher than that in control subjects (0.08 pg/mL). Multiple linear regression analysis showed that log C-reactive protein was significantly related to severe sites percentage and albumin following correction for age, gender, body mass index and smoking (p = 0.000, p = 0.008, respectively). Log interleukin-6 was found to be significantly correlated with periodontal diagnosis, leukocyte count and level of fasting blood glucose after adjusting for the confounders (p = 0.000, p = 0.009 and p = 0.013, respectively).

CONCLUSION

Patients with aggressive periodontitis have significantly elevated levels of plasma C-reactive protein and interleukin-6. These elevated inflammatory factors might potentially increase the risk for cardiovascular events and glucose dysregulation in relatively young individuals.

Testing the druggable endothelial differentiation gene 2 knee osteoarthritis genetic factor for replication in a wide range of sample collections

OBJECTIVES

To replicate a previously reported association with osteoarthritis (OA) of the promoter single nucleotide polymorphism (SNP) rs10980705 in the endothelial differentiation gene 2 (EDG2).

METHODS

Five collections of samples, four from Europe and one from China, were studied. They included patients with 3 OA phenotypes: 1501 with knee OA, 1497 with hip OA and 376 with generalised OA. A total of 2521 controls were also studied. Allele and genotype frequencies of the rs10980705 SNP were analysed in each individual sample collection and in pooled data. In addition, a meta-analysis to incorporate results from the original Japanese report was performed.

RESULTS

The association of the rs10980705 SNP with knee OA was not replicated in any of the five sample collections studied or in their combined analysis (odds ratio (OR) 1.10, 95% CI 0.98 to 1.22; p = 0.10). Meta-analysis of all data, including the original Japanese study, did show association with knee OA (OR 1.15, 95% CI 1.06 to 1.26; p = 0.002) but the effect was accounted for by the Japanese data and was less significant than the original report. No association was found with hip OA or with generalised OA.

CONCLUSIONS

The original report of a promising genetic association between a druggable G-protein coupled receptor, EDG2, and knee OA has not been replicated. This lack of replication could be due to a modest effect of the promoter polymorphism that will require even larger studies (the winners curse) although a more pronounced effect in the Asian population vs Europeans cannot be excluded.

A comparison of tumor characteristics between ER+/PR+ and ER+/PR- breast tumors in Chinese women

21097

Background: Although breast caner patients with any one of the two sex hormone receptors positive can be treated with endocrine therapy, many clinical data showed that there was different response to endocrine therapy for patients with ER+/PR+ and with ER+/PR- tumors. The aim of this study was to find out the factors related to PR expression by comparing the ER+/PR+ tumors and ER+/PR- tumors clinically and biologically. Methods: Between January 1990 to August 2006, 5,191 female breast cancer patients with known ER/PR expression status who received operation in our hospital were enrolled onto this retrospective study. Clinical and biological features of 2,227 patients with ER+/PR+ tumors were compared with those of 909 patients with ER+/PR- tumors. χ2 test was used for univariate analysis and logistic regression for multivariate analysis. Disease-free survival (DFS) and overall survival (OS) was calculated using Kaplan-Meier analyses, and all statistical tests were two-sided. Results: The peak onset age of patients with ER+/PR+ tumors and ER+/PR- tumors was 50, and it was significantly higher than that of patients with ER- tumors, which is 48(P=0.001). Univariate analysis showed that ER+/PR- tumors were larger in size, had more lymph nodes of metastasis, were higher in tumor grade than ER+/PR+ tumors. Furthermore, the expression of ER and CathepsinD was significantly lower, and CerbB-2 expression was higher in ER+/PR- tumors than in ER+/PR+ tumors. Multivariate analysis indicated that positive PR expression was associated with the level of ER(OR=1.792, P=0.000), CathepsinD(OR=1.380, P=0.035)and CerbB-2(OR=0.639, P=0.007). DFS(P=0.004) and OS(P=0.009) were higher among patients with PR-expressing tumors than with PR- negative tumors. Conclusions: ER+/PR+ tumors and ER+/PR- tumors may have the same etiology which is different from that of ER- tumors. Because of low ER level and changes of the expression of CerbB-2 and CathepsinD, the tumors that lacked PR expression display more aggressive features and have worse prognosis. According to these differences, new target of therapy and endocrine regimen may provide the possibility of improving the response and prognosis of endocrine therapy for patients with ER+/PR- tumors.

No significant financial relationships to disclose.

Development of Indirect Enzyme-linked Immunosorbent Assay with Nucleoprotein as Antigen for Detection and Quantification of Antibodies against Avian Influenza Virus

Avian influenza (AI) is a serious infectious disease caused by avian influenza virus (AIV) belonging to type A Orthomyxovirus. In the present study, we developed an indirect enzyme-linked immunosorbent assay (ELISA) employing E. coli-expressed full-length nucleoprotein (NP) of H9N2 avian influenza virus for the detection and quantification of antibodies against AIV nucleoprotein. The NP-ELISA was compared with the AI agar gel propagation (AGP) test, haemagglutination inhibition (HI) test, and IDEXX-FlockChek ELISA using 263 sera. The NP-ELISA was significantly more sensitive than the AGP and HI tests, and showed 96.2% agreement ratio with IDEXX-FlockChek ELISA. With results obtained using the NP-ELISA, an ELISA titre (ET) prediction equation, with which the ELISA titres of a flock or individual chickens can be determined, was derived from a positive/negative (P/N) ratio standard curve. The NP-ELISA enables an alternative rapid serological diagnosis and is suitable for influenza A antibody screening, especially in species that harbour several influenza subtypes.

Chaperoning of estrogen receptor and induction of mammary gland proliferation by neuronal protein synuclein gamma

Synucleins are emerging as central players in the formation of pathologically insoluble deposits characteristic of neurodegenerative diseases. However, synuclein gamma (SNCG), previously identified as a breast cancer specific gene (BCSG1), is also highly associated with breast cancer progression. Using transgenic mouse model, we demonstrated a role of SNCG in induction of highly proliferative pregnancy-like phenotype of mammary epithelial cells and branching morphology. SNCG participated in the heat shock protein-based multiprotein chaperone complex for steroid receptor signaling. Expression of SNCG in mammary epithelium resulted in a significant stimulation of ERalpha transcriptional activity. SNCG-induced mammary gland proliferation can be effectively blocked by antiestrogen and ovariectomy, indicating that the induced proliferation is mediated by ERalpha signaling and requires estrogen stimulation. These data indicate the chaperone activity of SNCG on stimulation of steroid receptor signaling in mammary gland and, thus induces extensive mammary gland proliferation and contributes to the hormonal impact on mammary tumorigenesis.

hHR23B is required for genotoxic-specific activation of p53 and apoptosis

Rad23 proteins function in both DNA repair and protein stability regulation. As ubiquitinated forms of p53 are stabilized after DNA damage in concert with p53 functional activation, and human Rad23 proteins (hHR23A and B) regulate p53 stability in unstressed cells, the role of hHR23B in post-genotoxin regulation of p53 was investigated. Depletion of hHR23B by specific short interfering RNA before genotoxic exposure attenuated p53, p21 and bax induction, abrogated the accumulation of ubiquitinated p53 and suppressed apoptosis. Expression of ubiquitin derivatives with all lysines mutated except K48 or K63 demonstrated that K48-linked p53-ubiquitin conjugates were specifically induced after DNA damage. hHR23B, along with native and ubiquitinated p53, accumulated in chromatin after genotoxic exposure, and the accumulation of ubiquitinated p53 in chromatin was prevented by hHR23B depletion. Chromatin immunoprecipitation analysis demonstrated that hHR23B and p53 both localized to the p21 promoter shortly after DNA damage. hHR23B thus plays a critical role in the activation and function of p53 after specific genotoxic exposures.

Sensitivity analysis applied to the construction of radial basis function networks

Conventionally, a radial basis function (RBF) network is constructed by obtaining cluster centers of basis function by maximum likelihood learning. This paper proposes a novel learning algorithm for the construction of radial basis function using sensitivity analysis. In training, the number of hidden neurons and the centers of their radial basis functions are determined by the maximization of the output's sensitivity to the training data. In classification, the minimal number of such hidden neurons with the maximal sensitivity will be the most generalizable to unknown data. Our experimental results show that our proposed sensitivity-based RBF classifier outperforms the conventional RBFs and is as accurate as support vector machine (SVM). Hence, sensitivity analysis is expected to be a new alternative way to the construction of RBF networks.