Quantitative assessment of the tetracycline resistance gene pool in cheese samples by real-time TaqMan PCR

A TaqMan real-time PCR assay was developed to quantify the tetS gene pool present in retail cheeses. This protocol offers a rapid, specific, sensitive, and culture-independent method for assessing antibiotic resistance genes in food samples rich in fats and proteins.     

Antifibrotic effect of the Chinese herbs, Astragalus mongholicus and Angelica sinensis, in a rat model of chronic puromycin aminonucleoside nephrosis

Nephrotic syndrome has long been treated in China with two herbs, Astragalus mongholicus and Angelica sinensis, which may have antifibrotic effects. METHODS: Rats with chronic puromycin-induced nephrosis were treated with Astragalus and Angelica 3 mL/d (n = 7) or enalapril 10 mg/kg/d (n = 7). Normal control rats (n = 7) received saline rather than puromycin, and an untreated control group (n = 7) received puromycin but no treatment. After 12 weeks, stained sections of the glomerulus and tubulointerstitium were evaluated for injury. Immunohistochemistry staining measured extracellular matrix components, transforming growth factor-beta1 (TGFbeta1), osteopontin, ED-1-positive cells, and alpha-actin. TGFbeta1 mRNA was assessed by in situ hybridization. Renin, ACE activity, angiotensin, and aldosterone were measured by radioimmunoassay or colorimetry. In the untreated rats, chronic renal injury progressed to marked fibrosis at 12 weeks. Astragalus and Angelica significantly reduced deterioration of renal function and histologic damage. Expressions of type III and IV collagen, fibronectin, and laminin also decreased significantly. This anti-fibrotic effect was similar to that of enalapril. The herbs had no effect on the renin-angiotensin system but did reduce the number of ED-1-positive, and alpha-actin positive cells and expression of osteopontin compared to untreated controls. The combination of Astragalus and Angelica retarded the progression of renal fibrosis and deterioration of renal function with comparable effects of enalapril. These effects were not caused by blocking the intrarenal renin-angiotensin system, but associated with suppression of the overexpression of TGFbeta1 and osteopontin, reduction of infiltrating macrophages, and less activation of renal intrinsic cells [corrected].     

Effectiveness of a Government-Organized and Hospital-Initiated Treatment for Multidrug-Resistant Tuberculosis Patients-A Retrospective Cohort Study

Background

In contrast to the conventional model of hospital-treated and government directly observed treatment (DOT) for multidrug-resistant tuberculosis (MDR-TB) patient care, the Taiwan MDR-TB Consortium (TMTC) was launched in May 2007 with the collaboration of five medical care groups that have provided both care and DOT. This study aimed to determine whether the TMTC provided a better care model for MDR-TB patients than the conventional model.

Methods and Findings

A total of 651 pulmonary MDR-TB patients that were diagnosed nation-wide from January 2000-August 2008 were enrolled. Of those, 290 (45%) MDR-TB patients whose initial sputum sample was taken in January 2007 or later were classified as patients in the TMTC era. All others were classified as patients in the pre-TMTC era. The treatment success rate at 36 months was better in the TMTC era group (82%) than in the pre-TMTC era group (61%) (p<0.001). With multiple logistic regressions, diagnosis in the TMTC era (adjusted odds ratio (aOR) 2.8, 95% confidence interval (CI) 1.9–4.2) was an independent predictor of a higher treatment success rate at 36 months. With the time-dependent proportional hazards method, a higher treatment success rate was still observed in the TMTC era group compared to the pre-TMTC era group (adjusted hazard ratio 6.3, 95% CI 4.2–9.5).

Conclusion

The improved treatment success observed in the TMTC era compared to the pre-TMTC era is encouraging. The detailed TMTC components that contribute the most to the improved outcome will need confirmation in follow-up studies with large numbers of MDR-TB patients.     

Cytisine attenuates bone loss of ovariectomy mouse by preventing RANKL‐induced osteoclastogenesis

Postmenopausal Osteoporosis (PMOP) is oestrogen withdrawal characterized of much production and activation by osteoclast in the elderly female. Cytisine is a quinolizidine alkaloid that comes from seeds or other plants of the Leguminosae (Fabaceae) family. Cytisine has been shown several potential pharmacological functions. However, its effects on PMOP remain unknown. This study designed to explore whether Cytisine is able to suppress RANKL‐induced osteoclastogenesis and prevent the bone loss induced by oestrogen deficiency in ovariectomized (OVX) mice. In this study, we investigated the effect of Cytisine on RAW 264.7 cells and bone marrow monocytes (BMMs) derived osteoclast culture system in vitro and observed the effect of Cytisine on ovariectomized (OVX) mice model to imitate postmenopausal osteoporosis in vivo. We found that Cytisine inhibited F‐actin ring formation and tartrate‐resistant acid phosphatase (TRAP) staining in dose‐dependent ways, as well as bone resorption by pit formation assays. For molecular mechanism, Cytisine suppressed RANK‐related trigger RANKL by phosphorylation JNK/ERK/p38‐MAPK, IκBα/p65‐NF‐κB, and PI3K/AKT axis and significantly inhibited these signalling pathways. However, the suppression of PI3K‐AKT‐NFATc1 axis was rescued by AKT activator SC79. Meanwhile, Cytisine inhibited RANKL‐induced RANK‐TRAF6 association and RANKL‐related gene and protein markers such as NFATc1, Cathepsin K, MMP‐9 and TRAP. Our study indicated that Cytisine could suppress bone loss in OVX mouse through inhibited osteoclastogenesis. All data provide the evidence that Cytisine may be a promising agent in the treatment of osteoclast‐related diseases such as osteoporosis.     

Molecular cloning, characterization and expression of a C-type lectin cDNA in Chinese mitten crab, Eriocheir sinensis

C-type lectins are pattern-recognition proteins which are functionally important for pathogen recognition and immune regulation in vertebrates and invertebrates. In this study, a lectin cDNA named as Es-Lectin was cloned and characterized from the Chinese mitten crab, Eriocheir sinensis. The full-length sequence of this Es-Lectin cDNA was 651 bp, including an open reading frame of 483 bp encoding 160 amino acids. The predicted molecular weight of the Es-Lectin was 11.8 kDa. A typical signal peptide of 21 amino acids was deduced at the N-terminus of the predicted protein. This Es-Lectin belongs to a C-type lectin and contains six cysteines, a conserved EPN motif (Glu-Pro-Asn) and an imperfect WND (Trp-Asn-Asp) motif (FND, Phe-Asn-Asp). This Es-Lectin had 55% and 32% identity with other two C-type lectins in E. sinensis, and 29-36% homology with decapods. Although the Es-Lectin was also expressed in gill, hepatopancreas, intestine, muscle and stomach, its expression in haemocytes was the greatest. The expression of Es-Lectins in haemocytes increased at 1.5 h after the Aeromonas hydrophila challenge. After a slight decrease, the Es-Lectin expression in haemocytes significantly increased at 48 h post-challenge. The diverse distribution of Es-Lectin and its enhancement by bacterial challenge indicate that C-type lectins are important in the innate immune response to bacterial infection, and can be activated for innate immune response in crab at the initial stage after pathogen infection.     

蜂毒变应原及蜂毒免疫治疗

膜翅目昆虫种类繁多,其中某些种类昆虫刺蛰后可以导致严重的甚至危及生命的过敏反应。目前,关于膜翅目毒液的成分和变应原的研究越来越广泛和深入。该文主要介绍膜翅目中蜜蜂毒液的主要成分、主要变应原及蜂毒过敏的免疫治疗。     

Changes in DNA methylation and transgenerational mobilization of a transposable element (mPing) by the topoisomerase II inhibitor, etoposide, in rice

ABSTRACT: BACKGROUND: Etoposide (epipodophyllotoxin) is a chemical commonly used as an anti-cancer drug which inhibits DNA synthesis by blocking topoisomerase II activity. Previous studies in animal cells have demonstrated that etoposide constitutes a genotoxic stress which may induce genomic instability including mobilization of normally quiescent transposable elements (TEs). However, it remained unknown whether similar genetically mutagenic effects could be imposed by etoposide in plant cells. Also, no information is available with regard to whether the drug may cause a perturbation of epigenetic stability in any organism. RESULTS: To investigate whether etoposide could generate genetic and/or epigenetic instability in plant cells, we applied etoposide to germinating seeds of six cultivated rice (Oryza sativa L.) genotypes including both subspecies, japonica and indica. Based on the methylation-sensitive gel-blotting results, epigenetic changes in DNA methylation of three TEs (Tos17, Osr23 and Osr36) and two protein-encoding genes (Homeobox and CDPK-related genes) were detected in the etoposide-treated plants (S0 generation) in four of the six studied japonica cultivars, Nipponbare, RZ1, RZ2, and RZ35, but not in the rest japonica cultivar (Matsumae) and the indica cultivar (93-11). DNA methylation changes in the etoposide-treated S0 rice plants were validated by bisulfite sequencing at both of two analyzed loci (Tos17 and Osr36). Transpositional activity was tested for eight TEs endogenous to the rice genome in both the S0 plants and their selfed progenies (S1 and S2) of one of the cultivars, RZ1, which manifested heritable phenotypic variations. Results indicated that no transposition occurred in the etoposide-treated S0 plants for any of the TEs. Nonetheless, a MITE transposon, mPing, showed rampant mobilization in the S1 and S2 progenies descended from the drug-treated S0 plants. CONCLUSIONS: Our results demonstrate that etoposide imposes a similar genotoxic stress on plant cells as it does on animal and human cells, which may induce transgenerational genomic instability by instigating transpositional activation of otherwise dormant TEs. In addition, we show for the first time that etoposide may induce epigenetic instability in the form of altered DNA methylation patterns in eukaryotes. However, penetration of the genotoxic effects of etoposide on plant cells, as being reflected as genetic and epigenetic instability, appears to be in a strictly genotype- and/or generation-dependent manner.     

Regulation of protein kinase FA (a transmembrane signal of insulin and epidermal growth factor) in the brain

Two forms of type-1 protein phosphatase activating factor (FA) termed FA1 and FA2 have been identified in plasma membranes of pig brain. FA1 is spontaneously active and trypsin-labile whereas FA2 is inactive and trypsin-resistant. Phospholipid reconstitution studies further indicate that the FA activity in the neutral phospholipids-reconstituted complex is spontaneously active and trypsin-labile whereas the FA activity in the acidic phospholipids-reconstituted complex is trypsin-resistant and inactive. The results indicate that inactive FA2 may have its catalytic domain interacted with negatively-charged phospholipids in brain membranes. This provides initial evidence for the regulation of protein kinase FA (a transmembrane signal of insulin and epidermal growth factor) in the central nervous system.