Pre-treatment with rapamycin protects hematopoiesis against radiation injury

Background: Protection of hematopoietic system has become a primary goal in the development of novel medical countermeasures against ionization radiation and radiotherapy. This study was to explore the role of rapamycin in normal tissues against radiation

Materials and Methods: Mice were pretreated with rapamycin by i.p. every other day for five times before 5 Gy or 8.5 Gy gamma-ray whole body irradiation. Blood cell counts, HE staining of bone marrow and liver, bone marrow transplantation, CFU of spleen were used to measure the damage of hematopoiesis and extramedullary hemopoietic organs. Regular karyotype analysis and expression of gamma-H2AX [by flow cytometry and western blot] were used to measure DNA damage. Rad 50 and DNA Lig 4 expression by western blot were to see the DNA repair ability

Results: The decrease of red blood cells and platelet induced by radiation were alleviated by pretreatment with rapamycin [d 7,15, p<0.01], and the long-term restoration of white blood cells, lymphocytes and bone marrow were enhanced in rapamycin pretreatment group [d 30,40,70, p<0.05]. The transplantation experiment also indicates that the long-term reconstitution in lethally irradiated recipient mice was improved in rapamycin group [p<0.05]. The hepatocellular injury by radiation was also reduced and the colony formation numbers of spleen after irradiation was improved in rapamycin group [p<0.05]. Karyotype analysis indicates that rapamycin protected bone marrow cells from chromosome mutation. Furthermore, expression of DNA repair proteins Rad 50 and DNA Lig 4 was enhanced and DNA damage marker gamma-H2AX was reduced in mice exposed to radiation by rapamycin pretreatment

Conclusion: Rapamycin pretreatment mitigates hematopoietic system from radiation injury in both bone marrow and extramedullary hematopoietic organs by improving genomic stability and increasing survival of hematopoietic stem and progenitor cells [HSPCs]

Relationship between white spot syndrome virus [WSSV] loads and characterizations of water quality in Litopenaeus vannamei culture ponds during the tropical storm

An in-situ experiment was conducted to investigate the effect of tropical storm on the white spot syndrome virus [WSSV] loads in Litopenaeus vannamei rearing ponds. White spot syndrome virus loads, heterotrophic bacteria, Vibrio and water quality [including temperature, dissolved oxygen [DO], salinity, pH, NH4-N, and NO2-N] were continually monitored through one tropical storm. The WSSV loads decreased when tropical storm made landfall, and substantially increased when typhoon passed. The variation of WSSV loads was correlated with DO, temperature, heterotrophic bacteria count, and ammonia-N concentrations. These results suggested that maintaining high level DO and promoting heterotrophic bacteria growth in the shrimp ponds might prevent the diseases' outbreak after the landfall of tropical storm

Histones and histone modifications of retina conditions and disorders / 中华实验眼科杂志

Retina conditions and disorders,such as age-related macular degeneration (AMD),diabetic retinopathy (DR),retinitis pigmentosa (RP) and retinal or choroidal tumors,are relevant diseases to retinal neurons and vasculatures.Although genetic factors such as gene mutation and single nucleotide polymorphisms cause changes of gene expression and involve in the pathogenesis of certain retinal diseases,the alteration of gene expression can be observed without changing the genome sequences under the external or internal stimuli.This epigenetic role,especially histones and its modification,has been considered as a part of mechanisms of those diseases described above.Current advances have drawn our attentions to this field in both pathological and therapeutical challenges of retinal diseases.

Comparison of a commercial ELISA with the modified agglutination test for detection of Toxoplasma gondii antibodies in sera of naturally infected dogs and cats

Toxoplasma gondii can infect all warm-blooded animals. Modified agglutination test [MAT] and ELISA are widely used for the detection of T. gondii antibodies. However, there is little information on their acceptability for detecting antibodies in companion animals. This study compared ELISA and MAT for their ability to detect T. gondii infection in naturally infected dogs and cats. Blood samples were collected from dogs and cats in different areas of Beijing, China and analyzed by ELISA and MAT. The ?2 test and k analysis were used to evaluate their efficiency and agreement. For dogs, the seroprevalence of T. gondii antibodies detected by ELISA was 34.7%, which was significantly higher than that detected by MAT [P<0.05]. There was no significant difference between ELISA and MAT for detecting T. gondii antibodies in cats. Good agreements between MAT and ELISA were seen in both dogs and cats; however, inconsistent results were demonstrated by k analysis and in MAT titer assay. Serum-based ELISA may be more satisfactory for screening test of T. gondii infection in dogs, whereas both methods could be acceptable in cats

Buoyant tablet formulations: biopharmaceutical consideration

Medium viscosity grade hydroxypropyl methylcellulose [4000 cps], carbopol 934p, stearyl alcohol and ascorbic acid were used to prepare six tablet formulations of captopril. Application of high compression force and carbopol were shown to exert an adverse effect on floating capability of the tablets. Tablet buoyancy was enhanced in response to presence of sufficient amount of stearyl alcohol in the formulation. Drug release was shown to be dependent on the amount of the polymer added and the drug loading level. No significant effect of hardness variation was observed on drug release profiles, moreover, patterns of the drug release were apparently enhanced with formulations contained relative large amount of stearyl alcohol. Non-floating tablet formulation [formulation A] revealed the lowest drug plasma level whereas floating tablets with enhanced invitro drug release [formulation F] exhibited an improved rate and extent of drug absorption compared to formulations A and B. Although the attained average Cmax and AUC with formulation F were 30% and 86% of that revealed by conventional tablets, respectively, tablets of formulation F were capable to deliver captopril over 12 hr with minimum fluctuation in drug plasma level. Good correlation [r = 0.9599] was found between invitro drug release and invivo drug absorbed from the floating tablets of formulations B and F

Polymorphisms of four STRs and their associations with IDDM in Chinese Han population / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To obtain the polymorphic data of short tandem repeat(STR) loci of D15S657, D11S1369, D6S2420 and D6S503 in Chinese Han population and to study the association of these four STR loci with insulin-dependent diabetes mellitus(IDDM).</p><p><b>METHODS</b>The polymorphisms of the four STRs were studied by polymerase chain reaction-polyacrylamide gel electrophoresis(PCR-PAGE) followed by direct sequencing of PCR products in 105 normal Chinese Hans and 48 patients with IDDM.</p><p><b>RESULTS</b>Seven alleles at D15S657 locus, 5 alleles at D11S1369 locus, 7 alleles at D6S2420 locus and 4 alleles at D6S503 locus were found. No deviation from Hardy-Weinberg equilibrium was observed. The heterozygosities of these loci were 0. 7524, 0.6000, 0.6286, 0.6571 and the polymorphic information contents(PIC) 0.7616, 0.4430, 0.5345 and 0.5932, respectively. The allele frequencies of allele A(5) at D15S657 locus, allele A(5) at D11S1369 locus and allele A(4) at D6S2420 locus were increased significantly in patients with IDDM, compared to those in the control group.</p><p><b>CONCLUSION</b>The four STRs, used as genetic markers, were suitable for case-control study, forensic medicine identification and population genetic study. There is an association between the polymorphisms of D15S657, D11S1369, D6S2420 and IDDM.</p>