An integrated experimental and physiologically based pharmacokinetic modeling study of penicillin G in heavy sows

Penicillin G is widely used in food‐producing animals at extralabel doses and is one of the most frequently identified violative drug residues in animal‐derived food products. In this study, the plasma pharmacokinetics and tissue residue depletion of penicillin G in heavy sows after repeated intramuscular administrations at label (6.5 mg/kg) and 5 × label (32.5 mg/kg) doses were determined. Plasma, urine, and environmental samples were tested as potential antemortem markers for penicillin G residues. The collected new data and other available data from the literature were used to develop a population physiologically based pharmacokinetic (PBPK) model for penicillin G in heavy sows. The results showed that antemortem testing of urine provided potential correlation with tissue residue levels. Based on the United States Department of Agriculture Food Safety and Inspection Service action limit of 25 ng/g, the model estimated a withdrawal interval of 38 days for penicillin G in heavy sows after 3 repeated intramuscular injections at 5 × label dose. This study improves our understanding of penicillin G pharmacokinetics and tissue residue depletion in heavy sows and provides a tool to predict proper withdrawal intervals after extralabel use of penicillin G in heavy sows, thereby helping safety assessment of sow‐derived meat products.     

Effects of intratracheal administration of aflatoxin G1 on the expression of CC-10 in rat lung tissues

AIM: To explore the putative effects of single intratracheal administration of aflatoxin G1 (AFG1) on the expression of CC-10 of lung tissues in SD rats. METHODS: Male SD rats were intratracheally administrated with AFG1 (30 μg/kg body weight) and the animals were respectively sacrificed at 1, 3, 7 and 14 d after AFG1 treatment. Bronchial alveolar lavage fluid (BALF) was centrifuged and the supernatants were collected for LDH release assay using Detection Kit with biochemical method. The expression of clara cell 10 kD protein (CC-10 protein) in lung tissues was determined by FCM analysis and Western blotting respectively. The expression of CC-10 at mRNA level was analyzed by RT-PCR. RESULTS: LDH activity in BALF after AFG1 treatment for 1, 3 and 7 d was significantly increased as compared to that in their corresponding control group (P<0.01) and restored to control level at 14 d after AFG1 treatment. FCM, Western blotting and RT-PCR results showed that no significant changes in CC-10 expression at both protein and mRNA levels were found between AFG1 group and control group 1 day after AFG1 treatment. While the CC-10 expressions of lung tissues at both protein level and mRNA levels in AFG1 treated group were significantly decreased as compared to those in their corresponding control group at 3, 7 and 14 d after AFG1 treatment (all P<0.01). CONCLUSION: Intratracheal administration of AFG1 may cause injuries and decrease the expression of CC-10 in lung tissues of SD rats in vivo.     

Influence of selenium administration to dry cows on selected biochemical and immune parameters of their offspring

The study was performed on 16 Holstein‐Friesian calves divided into two groups of eight animals each. The first group was composed of calves whose mothers did not receive selenium supplements (Se0). The second group consisted of calves whose mothers were administered intramuscular injections of a selenium and vitamin E supplement containing 0.5 of sodium selenite/ml and 50 mg of tocopherol acetate/ml in a single dose of 30 ml (Se30) ml, 10 days before the expected parturition date (10 ± 2 days). The calves were fed 2.5 L of the mother's colostrum administered by stomach tube 2 hr after birth and another 2 L 6 hr after birth. Blood from all calves was collected 7 times from external jugular vein (day 0–before colostrum administration and on the 2nd, 3rd, 4th, 7th, 14th and 21st days of life) for analyses of selenium, ceruloplasmin, transferrin, lactoferrin, immunoglobulin G (IgG) concentrations and gamma‐glutamyl transferase (GGT) and lysozyme activity. Selenium concentration was significantly higher in calves whose mothers received selenium supplements than in the offspring of non‐supplemented cows until 72 hr after birth (p ≤ .05). Lysozyme and GGTP activity and IgG concentration were significantly higher in the S30 group during the entire experiment (p ≤ .05). Supplementation of selenium to the mothers did not influence the ceruloplasmin, lactoferrin and transferrin levels in calves. A single injection of a selenium supplement administered to cows during late pregnancy increases selenium levels in calves and enhances passive transfer from the mother to the offspring.     

Interaction of polymorphisms in resistin gene promoter -420C/G,cytochromes P4501A1 gene MspI and cigarette smoking on nonalcoholic fatty liver disease

AIM: To investigate the interaction of polymorphisms of resistin gene promoter -420C/G, cytochromes P4501A1-MspI and cigarette smoking in nonalcoholic fatty liver disease (NAFLD). METHODS: The genetic polymorphisms in resistin gene promoter -420C/G and CYP1A1-MspI were analyzed by the technique of polymerase chain reaction (PCR) in peripheral blood leukocytes of 900 NAFLD cases and 900 healthy persons. RESULTS: The frequencies of -420C/G (GG) and CYP1A1-MspI (m2/m2) were 49.75% and 50.08% in NAFLD cases and 24.00% and 24.25% in healthy controls, respectively. Statistical tests showed a significant difference in the frequencies between the 2 groups (P<0.01). The risk of NAFLD with -420C/G (GG) was significantly higher than that of controls. Individuals who carried with CYP1A1-MspI (m2/m2) had a high risk of NAFLD. Combined analysis of the polymorphisms showed that the percentages of -420C/G (GG)/CYP1A1-MspI (m2/m2) in NAFLD and control groups were 39.83% and 12.83%, respectively (P<0.01). The people who carried with -420C/G (GG)/CYP1A1-MspI(m2/m2) had a high risk in NAFLD group. The cigarette smoking rate in NAFLD group was signi-ficantly higher than that in control group (P<0.01), and the statistic analysis suggested an interaction between cigarette smoking and -420C/G (GG) and CYP1A1-MspI (m2/m2), which increased the risk of NAFLD.CONCLUSION: -420C/G (GG), CYP1A1-MspI (m2/m2) and cigarette smoking are the risk factors in NAFLD. The interactions between genetic polymorphisms in -420C/G, CYP1A1- MspI (m2/m2) and cigarette smoking increase the risk of NAFLD.     

桉树体内的生根抑制物质研究综述*

对桉树内源生根抑制物Ｇ和“巨桉酚”，分别列出了化学结构和物理性质，分析对植物生根的抑制作用表明，随着茎叶组织成熟，Ｇ含量上升；不同种类桉树和不同成熟度的组织，Ｇ含量也不同，并有周期性的变化，在１０＾－４Ｍ时，抑制巨桉插条３０％－４０％发根，但在１０＾－５Ｍ时，不表现有抑制作用，巨桉的幼苗随着茎节数增多，Ｇ含量升高，在１２节数时，生根率几为０。两者的生理效应还有抑制种子萌发和叶片光合作用，具有生长素     

苏云金芽孢杆菌七个亚种酌DNA的G+C克分子百分数的测定

苏云金芽孢杆菌在害虫的生物防治以及植物抗虫育种中的作用日益扩大。该类细菌资源的开发和利用越来越被重视,而正确的分类鉴定方法是进行该项研究的基础。目前苏云金芽孢杆菌的分类鉴定是根据形态特征、生理生化特性、鞭毛抗原(H)的血清型以及营养细胞的酯酶型等,将其分为31个亚种。随着分子生物学和遗传学的高速发展,     

对两个分离自海南尖峰岭的木本豆科植物根瘤菌菌株的多相鉴定

对分离自海南尖峰岭自然保护区木本豆科植物的2个根瘤菌菌株RIF200835和RIF200845进行了鉴定.这两个菌株的16S rDNA序列同模式菌株Rhizobium miluonense CCUAU 41251T的相似度分别为98.28％和98.51％.对这两个菌株进行全细胞脂肪酸组分和全细胞醌组分的分析结果表明,菌株RIF200835和RIF200845在组分上与模式菌株较为一致,但在含量上稍有差异.RIF200835和RIF200845这两个菌株的DNA G+Cmol％含量分别为63.68％和60.56％,介于根瘤菌G+Cmol％含量范围(57％～65％)之内.这两个菌株的看家基因atpD、glnⅡ、recA 和rpoB,不同于模式菌株,而独立聚成一个分支.研究结果表明,菌株RIF200835和RIF200845可能为根瘤菌属Rhizobium中的新种.     

Evaluation of the conjunctival swab for canine visceral leishmaniasis diagnosis by PCR-hybridization in Minas Gerais State, Brazil

Larvae of Oestrus ovis (Diptera: Oestridae) are ubiquitous parasites of nasal and sinusal cavities of sheep and goats. According to the chronobiology of O. ovis infections in Sardinia and the seasonal pattern of the IgG response, the optimal period to investigate the relationships between O. ovis larval populations and intensity of local and systemic IgG antibody responses was mid-July in the summer season. Sarda x Lacaune ewes (n=186), divided into three ram-families were used in the study. Systemic and local IgG responses were measured by ELISA tests using second stage larval crude extracts (L2CE) and L2 (L2SGC) and L3 (L3SGC) salivary gland contents as coating antigens. The number of larval instars, larval length of L1, L2 and L3 larvae, and larval weight of L2 and L3 larvae were individually recorded after ewe necropsy. Negative correlations among larval establishment and/or larval development on the one hand and intensity of local or systemic IgG responses on the other hand were found in two out of three studied ram-families.     

Protein electrophoresis of psittacine plasma

BACKGROUND: Although protein electrophoresis (EPH) has been widely applied in human and veterinary medicine, it has only recently been implemented in the analysis of avian samples. OBJECTIVE: The purpose of this study was to examine the application of protein EPH to the analysis of psittacine plasma samples. Our goals were to describe protein fraction mobility, establish reference intervals for some common species, determine the coefficient of variation (CV) of the chosen method, and examine the effects of sample handling and sample condition. METHODS: Heparinized plasma samples from several common psittacine species (minimum sample size 50 each) were examined using the Beckman Paragon system and SPEP-II gels. Total protein was measured by refractometry. Reference intervals (95%) were calculated by the rank methods. RESULTS: Fraction migration patterns were found to vary among common psittacine species. Day-to-day CV for the EPH fractions ranged from 2.2% to 10.5%; within-run CV ranged from 4.8% to 10.8%; and total CV ranged from 3.2% to 14.8%. The highest CV was noted for the poorly defined alpha-globulin fraction. Prolonged refrigeration, repeated freeze-thawing, hemolysis, and lipemia altered the results. CONCLUSIONS: Protein fractions from psittacine species were variable in terms of migration pattern and protein concentration, which necessitates the use of species-specific reference intervals. Avian protein electrophoretic patterns and values should be interpreted based on knowledge of the CV associated with the technique as well as on the effects of sample handling and condition.