抗大麦黄矮病的小偃麦易位系的创制与鉴定

抗大麦黄矮病的小偃麦易位系的创制与鉴定@辛志勇$中国农业科学院作物育种载培研究所!北京100081@张增燕$中国农业科学院作物育种载培研究所!北京100081@陈孝$中国农业科学院作物育种载培研究所!北京100081@林志珊$中国农业科学院作物育种载培研究所!北京100081大麦;;小偃麦;;易位系     

Sex determination of buffalo embryos (Bubalus bubalis) by polymerase chain reaction

The aim of this study was to identify a simple, rapid method for sex determination of in vitro produced buffalo embryos, amplifying Y-chromosome-specific repeat sequences by polymerase chain reaction (PCR). Buffalo oocytes collected from slaughtered animals were matured, fertilised and cultured in vitro for 7 days. On day 7 embryos were evaluated and divided in to six groups according to developmental stage (2, 4, 8, 16 cells, morulae and blastocyst). Each embryo was stored singly in phosphate-buffered saline at -20 degrees C until PCR. Two different methods of extraction of DNA were compared: a standard procedure (ST), using a normal extraction by phenol-chloroform, isoamyl alcohol and final precipitation in absolute ethanol and a direct procedure (DT), using a commercial kit (Qiaquik-Qiagen mini blood). A pair of bovine satellite primers and two pairs of different bovine Y-chromosome-specific primers (BRY4.a and BRY.1) were used in the PCR assay on embryos and on whole blood samples collected from male and female adult buffaloes, used as control. The trial was carried out on 359 embryos (193 for ST and 166 for DT). When DNA samples from blood were amplified, the sex determined by PCR always corresponded to the anatomical sex. Embryo sexing was not possible in two embryos in ST and one embryo in DT. Both extraction protocols recovered sufficient quantities of target DNA at all developmental stages, but the time required for the ST (24 h) limits its use in embryo sexing and supports the use of commercial extraction kits (5 h).     

光动力疗法治疗感染性疾病的动物模型

光动力疗法(photodynamic therapy,PDT)是利用特定波长的激发光照射生物靶标上的光敏剂,从而产生活性氧并有效杀伤多种耐药病原体的新型治疗方式,具有作用广、安全可控、不易耐受等优点。大量体外实验已证实了PDT疗效,但目前动物实验数据较少,且治疗参数不一,一定程度上影响了PDT在临床治疗中的广泛应用。本文综述近年来PDT用于体内抗感染治疗的动物模型构建、治疗方案设计等方面的研究进展,为未来PDT抗感染研究及临床应用提供参考。     

Circular dichroism study of ribonuclease A mutants containing the minimal structural requirements for dimerization and swapping

Four residues Pro19, Leu28, Cys31 and Cys32 proved to be the minimal structural requirements in determining the dimeric structure and the N-terminal segment swapping of bovine seminal ribonuclease, BS-RNase. We analyzed the content of secondary and tertiary structures in RNase A, P-RNase A, PL-RNase A, MCAM-PLCC-RNase A and MCAM-BS-RNase, performing near and far-UV CD spectra. It results that the five proteins have very similar native conformations. Thermal denaturation at pH 5.0 of the proteins, studied by means of CD measurements, proved reversible and well represented by the two-state ND transition model. Thermodynamic data are discussed in the light of the structural information available for RNase A and BS-RNase.     

The MAPK pathway triggers activation of Nek2 during chromosome condensation in mouse spermatocytes

Chromosome condensation during the G2/M progression of mouse pachytene spermatocytes induced by the phosphatase inhibitor okadaic acid (OA) requires the activation of the MAPK Erk1. In many cell systems, p90Rsks are the main effectors of Erk1/2 function. We have identified p90Rsk2 as the isoform that is specifically expressed in mouse spermatocytes and have shown that it is activated during the OA-triggered meiotic G2/M progression. By using the MEK inhibitor U0126, we have demonstrated that activation of p90Rsk2 during meiotic progression requires activation of the MAPK pathway. Immunofluorescence analysis indicates that activated Erks and p90Rsk2 are tightly associated with condensed chromosomes during the G2/M transition in meiotic cells. We also found that active p90Rsk2 was able to phosphorylate histone H3 at Ser10 in vitro, but that the activation of the Erk1/p90Rsk2 pathway was not necessary for phosphorylation of H3 in vivo. Furthermore, phosphorylation of H3 was not sufficient to cause condensation of meiotic chromosomes in mouse spermatocytes. Other proteins known to associate with chromatin may represent effectors of Erk1 and p90Rsk2 during chromosome condensation. Nek2 (NIMA-related kinase 2), which associates with chromosomes, plays an active role in chromatin condensation and is stimulated by treatment of pachytene spermatocytes with okadaic acid. We show that inhibition of the MAPK pathway by preincubation of spermatocytes with U0126 suppresses Nek2 activation, and that incubation of spermatocyte cell extracts with activated p90Rsk2 causes stimulation of Nek2 kinase activity. Furthermore, we show that the Nek2 kinase domain is a substrate for p90Rsk2 phosphorylation in vitro. These data establish a connection between the Erk1/p90Rsk2 pathway, Nek2 activation and chromosome condensation during the G2/M transition of the first meiotic prophase.     

Relationships between Body Fat Distribution,Epicardial Fat and Obstructive Sleep Apnea in Obese Patients with and without Metabolic Syndrome

Background

Obstructive sleep apnea (OSA) and metabolic syndrome, both closely related to obesity, often coexist in affected individuals; however, body mass index is not an accurate indicator of body fat and thus is not a good predictor of OSA and other comorbidities. The aim of this study was to investigate whether the occurrence of OSA could be associated with an altered body fat distribution and a more evident cardio metabolic risk independently from obesity and metabolic syndrome.

Methods and Results

171 consecutive patients (58 men and 113 women) were included in the study and underwent overnight polysomnography. Anthropometric data, blood pressure, lipid profile, glycaemic parameters were recorded. Body composition by DXA, two-dimensional echocardiography and carotid intima/media thickness measurement were performed. 67 patients (39.2%) had no OSA and 104 (60.8%) had OSA. The percentage of patients with metabolic syndrome was significantly higher among OSA patients (65.4%) that were older, heavier and showed a bigger and fatter heart compared to the control group. Upper body fat deposition index , the ratio between upper body fat (head, arms and trunk fat in kilograms) and lower body fat (legs fat in kilograms), was significantly increased in the OSA patients and significantly related to epicardial fat thickness. In patients with metabolic syndrome, multivariate regression analyses showed that upper body fat deposition index and epicardial fat showed the best association with OSA.

Conclusion

The occurrence of OSA in obese people is more closely related to cardiac adiposity and to abnormal fat distribution rather than to the absolute amount of adipose tissue. In patients with metabolic syndrome the severity of OSA is associated with increase in left ventricular mass and carotid intima/media thickness.     

DNMT3b 39179G‎T Polymorphism and the Risk of Adenocarcinoma of the Colon in Koreans

DNA-methyltransferase-3B (DNMT3b) plays an important role in the generation of aberrant methylation in carcinogenesis. DNMT3b SNP has been associated with susceptibility to lung, head, neck, and breast cancer, but its association with the development of colon cancer has not been reported. We investigated the relationship between the 39179G‎T polymorphism in the DNMT3b gene, which is involved in de novo methylation and is associated with the risk of adenocarcinoma of the colon in Koreans. The DNMT3b 39179G‎T genotypes were determined by a PCR-RFLP method in 248 adenocarcinomas of colon cancer patients and in 248 healthy controls matched as to age and sex. When stratified by sex and age, a significantly reduced risk of the combined GT and GG genotypes was observed in younger patients (<59, adjusted OR = 0.255, 95% CI = 0.133–0.489) and in male patients (adjusted OR = 0.383, 95% CI = 0.225–0.652). The DNMT3b 39179G‎T polymorphism may be a genetic determinant of adenocarcinoma of the colon, especially in younger Korean men.     

Therapeutics development for triplet repeat expansion diseases

The underlying genetic mutations for many inherited neurodegenerative disorders have been identified in recent years. One frequent type of mutation is trinucleotide repeat expansion. Depending on the location of the repeat expansion, the mutation might result in a loss of function of the disease gene, a toxic gain of function or both. Disease gene identification has led to the development of model systems for investigating disease mechanisms and evaluating treatments. Examination of experimental findings reveals similarities in disease mechanisms as well as possibilities for treatment.     

Antimicrobial and antistaphylococcal biofilm activity from the sea urchin Paracentrotus lividus

Aims:  Staphylococcal biofilm-associated infections are resistant to conventional antibiotics. Consequently, new agents are needed to treat them. With this aim, we focused on the effector cells (coelomocytes) of the sea urchin Paracentrotus lividus immune system.
Methods and Results:  We tested the activity of the 5-kDa peptide fraction of the cytosol from coelomocytes (5-CC) against a group of Gram-positive, Gram-negative bacteria and fungi. We determined minimal inhibitory concentrations (MICs) ranging from 253·7 to 15·8 mg ml⁻¹. We observed an inhibitory activity and antibiofilm properties of 5-CC against staphylococcal biofilms of reference strains Staphylococcus epidermidis DSM 3269 and Staphylococcus aureus ATCC 29213. The antimicrobial efficacy of 5-CC against the biofilms of clinical strain Staph. epidermidis 1457 was also tested using live/dead staining in combination with confocal laser scanning microscopy. At a sub-MIC concentration (31·7 mg ml⁻¹) of 5-CC the formation of young (6-h old) and mature (24-h old) staphylococcal biofilms was inhibited.
Conclusions:  The biological activity of 5-CC could be attributed to three peptides belonging to the sequence segment 9–41 of a beta-thymosin of P. lividus .
Significance and Impact of the Study:  The effector cells of P. lividus represent an interesting source of marine invertebrates-derived antimicrobial agents in the development of new strategies to treat staphylococcal biofilms.     

Persistence of the control of the fluctuations of heart rate in the anesthetized and pithed adult rat. Effect of enteraminergic drugs]

Spontaneous fluctuations in heart rate were analyzed by spectral analysis in the ether anesthetized and pithed adult rat. In order to investigate the changes in the spectral pattern of the fluctuations, the selective 5HT-2 and -3 isoreceptor blockers ritanserin and BRL 43694A were used. In both the experimental conditions, ritanserin blockade led to dose-dependent increased fluctuations in HR low and high frequencies. In both the anesthetized and pithed rats, the low frequency range HR fluctuations were drastically reduced by BRL 43694A.