Intramuscular therapeutic doses of enrofloxacin affect microbial community structure but not the relative abundance of fluoroquinolones resistance genes in swine manure.

Livestock manure is a major source of veterinary antibiotics and antibiotic resistance genes (ARGs). Elucidation of the residual characteristics of ARGs in livestock manure following the administration of veterinary antibiotics is critical to assess their ecotoxicological effects and environmental contamination risks. Here, we investigated the effects of enrofloxacin (ENR), a fluoroquinolone antibiotic commonly used as a therapeutic drug in animal husbandry, on the characteristics of ARGs, mobile genetic elements, and microbial community structure in swine manure following its intramuscular administration for 3 days and a withdrawal period of 10 days. The results revealed the highest concentrations of ENR and ciprofloxacin (CIP) in swine manure at the end of the administration period, ENR concentrations in swine manure in groups L and H were 88.67 ± 45.46 and 219.75 ± 88.05 mg/kg DM, respectively. Approximately 15 fluoroquinolone resistance genes (FRGs) and 48 fluoroquinolone-related multidrug resistance genes (F-MRGs) were detected in swine manure; the relative abundance of the F-MRGs was considerably higher than that of the FRGs. On day 3, the relative abundance of qacA was significantly higher in group H than in group CK, and no significant differences in the relative abundance of other FRGs, F-MRGs, or MGEs were observed between the three groups on day 3 and day 13. The microbial community structure in swine manure was significantly altered on day 3, and the altered community structure was restored on day 13. The FRGs and F-MRGs with the highest relative abundance were qacA and adeF, respectively, and Clostridium and Lactobacillus were the dominant bacterial genera carrying these genes in swine manure. In summary, a single treatment of intramuscular ENR transiently increased antibiotic concentrations and altered the microbial community structure in swine manure; however, this treatment did not significantly affect the abundance of FRGs and F-MRGs.

Functional and physical interaction between the selenium-binding protein 1 (SBP1) and the glutathione peroxidase 1 selenoprotein.

Selenium-binding protein (SBP) 1 is present in reduced levels in several cancer types as compared with normal tissues, and lower levels are associated with poor clinical prognosis. Another selenium-containing protein, glutathione peroxidase 1 (GPX1), has been associated with cancer risk and development. The interaction between these representatives of different classes of selenoproteins was investigated. Increasing SBP1 levels in either human colorectal or breast cancer cells by transfection of an expression construct resulted in the reduction of GPX1 enzyme activity. Increased expression of GPX1 in the same cell types resulted in the transcriptional and translational repression of SBP1, as evidenced by the reduction of SBP1 messenger RNA and protein and the inhibition of transcription measured using an SBP1 reporter construct. The opposing effects of SBP1 and GPX1 on each other were also observed when GPX1 was increased by supplementing the media of these tissue culture cells with selenium, and the effect of selenium on SBP1 was shown to be GPX1 dependent. Decreasing or increasing GPX1 levels in colonic epithelial cells of mice fed a selenium-deficient, -adequate or -supplemented diet resulted in the opposing effect on SBP1 levels. These data are explained in part by the demonstration that SBP1 and GPX1 form a physical association, as determined by coimmunoprecipitation and fluorescence resonance energy transfer assay. The results presented establish an interaction between two distinct selenium-containing proteins that may enhance the understanding of the mechanisms by which selenium and selenoproteins affect carcinogenesis in humans.

Effect of yiqi huoxue recipe on cardiac function and ultrastructure in regression of pressure overload-induced myocardial hypertrophy in rats.

OBJECTIVE: To investigate the effect of Yiqi Huoxue Recipe (YHR) on the cardiac function and ultrastructure during the regression of myocardial hypertrophy induced by pressure overload in rats. METHODS: The model of myocardial hypertrophy was established by abdominal aortic banding. Eighty male Wistar rats were divided into six groups, the normal control group I (n=20), the normal control group II (n=12), the hypertension model group I (n=12), the hypertension model group II (n=12), the YHR group (n=12) and the Captopril group (n=12). The observation was carried out in the normal control group I and the hypertension model group I after 4 weeks of modeling, and the other four groups were observed after 16 weeks of modeling (12 weeks of administration). The cardiac function was measured with a multichannel biological signal analysis system, and the myocardium ultrastructure was observed by a transmission electron microscope. RESULTS: (1) Compared with the normal control group I, the systolic blood pressure and cardiac coefficient (left ventricular weight/body weight) in the model I group was higher (P<0.05, P<0.01). (2) In the YHR group, cardiac coefficient and -dp/dt(max) were lower, left ventricular systolic pressure and +dp/dt(min) were higher when compared with the model group II and the Captopril group (P<0.05 or P<0.01). In the Captopril group, only cardiac coefficient was lower when compared with the mode group II (P<0.05). (3) Compared with the normal control group II, +dp/dt(max) was higher (P<0.01) -dp/dt(max) and isovolumetric contraction time (ICT) was lower (P<0.05, P<0.01) in both the YHR group and the Captopril group. (4) Results of the myocardium ultrastructure showed edema under myocardium plasmalemma, enlarged sarcoplasmic reticulum and T tube, and significantly enlarged intercalated disc of the cardiac muscle in the model groups. In the Captopril group, the extension of sarcoplasmic reticulum and T tube as well as the pathological changes of intercalated disc were lighter, with slight edema under the myocardium plasmalemma. In the YHR group, the expansion of the sarcoplasmic reticulum was less than in the Captopril group, part of the pathological changes of intercalated discs was slightly more severe than that in the Captopril group, the dissolution of nuclear chromatin was not found, which was similar to that of the Captopril group, and no injury of the nucleus was found, either. CONCLUSION: YHR could reverse myocardial hypertrophy in rats with abdominal aortic banding and improve the systolic and diastolic function of the left ventricle. The ultrastructure of the myocardium such as arcoplasmic reticulum, intercalated disc, and cell nucleus in abdominal aortic banding rats could be partly reversed by the recipe.

[Genetic diversity of Eucommia ulmoides by RAPD analysis].

OBJECTIVE: To determine the genetic diversity of Eucommia ulmoides. METHOD: 260 samples of 20 populations were analyzed through radom amplified polymorphic DHA (RAPD). RESULT: Total polymorphic loci percentage was 96.36 and the average was 38.92. 110 bands were produced with 10 random primers and 106 were polymorphic. Nei's gene diversity (H) was 0.246 1, Shannon's Information index(I) was 0.386 8, Gst was 0.424 4, indicating that 42.44% of the genetic variation was distributed among populations and 57.65% within populations. CONCLUSION: The genetic variation was relatively high in E. ulmoides, so the genetic diversity conservation principle should mainly focus on protection of the populations.