Phylogenetic analysis of archaea in three fractions of cow rumen based on the 16S rDNA sequence

Phylogenetic analysis of archaea in the rumen ecosystem was analysed by PCR of 16S rDNA from the bovine rumen using archaea-specific primers. The libraries were constructed from rumen fluid (AF), rumen solid (AS), and rumen epithelium (AE) from a rumen-fistulated Korean cow (Hanwoo). The 45 AF clones could be divided into three groups and the largest group was affiliated with the Methanomicrobiaceae family (96% of clones). The AF clones contained a high proportion of unidentifiable clones (67%). The 39 AE clones could be divided into two groups and the largest group was also affiliated with the Methanomicrobiaceae family (95% of clones). The AE clones contained a low proportion of unidentifiable clones (5%). The 20 AS clones could be divided into two groups that were affiliated with either the Methanobacteriaceae family (55%) or the Methanomicrobiaceae family (45%). The AS clones contained a moderate proportion of unidentifiable clones (40%). The predominant family of whole rumen archaea was found to belong to the Methanomicrobiaceae (85%). Methanomicrobiaceae were predominant in the rumen epithelium and the rumen fluid while Methanobacteriaceae were predominant in the rumen solid. One clone from the rumen fluid and two clones from the rumen epithelium contained rDNA sequences of Non-Thermophilic-Crenarchaeota (NTC) and Thermophilic-Crenarchaeota (TC), respectively, which have not previously been described from the rumen.     

Human VEGF165-myoblasts produce concomitant angiogenesis/myogenesis in the regenerative heart

Bioengineering the regenerative heart may provide a novel treatment for heart failure. On May 14, 2002, a 55-year-old man suffering from ischemic myocardial infarction received 25 injections carrying 465 million cGMP-produced pure myoblasts into his myocardium after coronary artery bypass grafting. As on August 28, 2002, his EKG was normal and showed no arrhythmia. His ejection fraction increased by 13%. He no longer experienced shortness of breath and angina as he did before the treatment. Three myogenesis mechanisms were elucidated with 17 human/porcine xenografts using cyclosporine as immunosuppressant. Some myoblasts developed to become cardiomyocytes. Others transferred their nuclei into host cardiomyocytes through natural cell fusion. As yet others formed skeletal myofibers with satellite cells. De novo production of contractile filaments augmented the heart contractility. Human myoblasts transduced with VEGF₁₆₅ gene produced six times more capillaries in porcine myocardium than in placebo. Xenograft rejection was not observed for up to 20 weeks despite cyclosporine discontinuation at 6 weeks. Pros and cons of autografts vs. allografts are compared to guide future development of heart cell therapy. (Mol Cell Biochem 263: 173–178, 2004)     

Status of intestinal parasite infections among children in Bat Dambang, Cambodia

A survey was conducted to determine the extent of intestinal parasite infection in Bat Dambang, Cambodia in March 2004. A total of 623 fecal specimens was collected from kindergarten and schoolchildren and examined using the formalin-ether sedimentation technique. The overall infection rate of intestinal parasites was 25.7% (boys, 26.2%; girls, 25.1%), and the infection rates of intestinal helminthes by species were as follows: Echinostoma sp. 4.8%, hookworm 3.4%, Hymenolepis nana 1.3%, and Rhabditis sp. 1.3%. The infection rates of intestinal protozoa were; Entamoeba coli 4.8%, Giardia lamblia 2.9%, Iodamoeba butschlii 1.4%, Entamoeba polecki 1.1%, and Entamoeba histolytica 0.8%. There were no egg positive cases of Ascaris lumbricoides or Trichuris trichiura. All children infected were treated with albendazole, praziquantel, or metronidazole according to parasite species. The results showed that intestinal parasites are highly endemic in Bat Dambang, Cambodia.     

Phospholipase C-delta1 rescues intracellular Ca2+ overload in ischemic heart and hypoxic neonatal cardiomyocytes

Ischemia and simulated ischemic conditions cause intracellular Ca2+ overload in the myocardium. The relationship between ischemia injury and Ca2+ overload has not been fully characterized. The aim of the present study was to investigate the expression and characteristics of PLC isozymes in myocardial infarction-induced cardiac remodeling and heart failure. In normal rat heart tissue, PLC-delta1 (about 44 ng/mg of heart tissue) was most abundant isozymes compared to PLC-gamma1 (6.8 ng/mg) and PLC-beta1 (0.4 ng/mg). In ischemic heart and hypoxic neonatal cardiomyocytes, PLC-delta1, but not PLC-beta1 and PLC-gamma1, was selectively degraded, a response that could be inhibited by the calpain inhibitor, calpastatin, and by the caspase inhibitor, zVAD-fmk. Overexpression of the PLC-delta1 in hypoxic neonatal cardiomyocytes rescued intracellular Ca2+ overload by ischemic conditions. In the border zone and scar region of infarcted myocardium, and in hypoxic neonatal cardiomyocytes, the selective degradation of PLC-delta1 by the calcium sensitive proteases may play important roles in intracellular Ca2+ regulations under the ischemic conditions. It is suggested that PLC isozyme-changes may contribute to the alterations in calcium homeostasis in myocardial ischemia.     

中国人胃癌染色体17q21区域基因遗传不稳定性研究

To investigate microsatellite instability (MSI) and loss of heterozygosity (LOH) of locus D17S396, D17S579 and D17S855, and their effect on the expression of nm23H1 and BRCA1 of gastric cancer, which would provide experimental basis for clinical treatment and prognosis analysis of gastric cancer. DNA was extracted from paraffin-embedded materials. Polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP) was used to analyze MSI and LOH. Expression of nm23H, and BRCA1 was detected by Envision immuno-histochemistry and Leica-Qwin computer imaging techniques. In the forty cases of gastric cancer, the frequency of MSI, LOH and nm23H1 protein were 20.00%, 17.50% and 55.00% respectively at locus D17S396, while at locus D17S579, the frequency of MSI, LOH and BRCA1 protein were 22.50%, 15.00% and 37.50% respectively; at locus D17S855, the frequency of MSI, LOH and BRCA1 of thirty-seven cases were 18.92%, 18.92%, 37.84% respectively. In tumor node metastasis (TNM) staging, at locus D17S396, D17S579 and D17S855, MSI in stages I + II appeared more frequently than that in stages III + IV, while LOH appeared the contrary tendency. In the group of metastasis of gastric cancer, MSI had a less frequency (5.00%) than that with no metastasis (35.00%, P < 0.05) at locus D17S396, but LOH appeared more frequently (30.00%) than that with no metastasis (5.00%, P < 0.05). At locus D17S579, MSI had an increasing tendency with the degree of tumor differentiation (50.00% in high differentiation cases, 20.00% in middle differentiation cases, and 0% in low differentiation cases, P < 0.05). The frequency of nm23H1 and BRCA1 protein in stages TNM I + II was higher than that in stages TNM III + IV; and that in higher differentiation cases was higher than in poor differentiation cases. The frequency of nm23H1 protein in the group of metastasis (30.00%) was less than that with no metastasis significantly (80.00%, P<0.01). The frequency of nm23H1 protein in the group positive to MSI (87.50%) was higher than that in the group negative to MSI (46.88%, P < 0.05). However, nm23H1 protein in group positive to LOH (14.29%) was lower than that in the group negative to LOH (63.64%, P < 0.05). The frequency of BRCA1 protein in the group positive to MSI (66.67%) was more than that in the group negative to MSI (29.03%, P < 0.05). The results of experiments indicate that MSI and LOH may separately control the development of sporadic colon cancer with different pathways. MSI may be an early period molecule marker for sporadic colon cancer, enhanced expression of nm23H1 protein can effectively inhibit colon cancer metastasis and improve prognosis of sporadic colon cancer patients. By comparison, LOH mostly arises in the late period of sporadic colon cancer and endows a high aggressive and poor prognostic phenotype. nm23H1 protein could effectively restrain gastric cancer metastasis and development; and BRCA1 protein could restain tumor from becoming lower differentiation.     

Vimentin and 70K Neurofilament Protein Co-exist in Embryonic Neurones from Spinal Ganglia

Abstract: The mesenchymal intermediate filament protein vimentin and the 70K component of neurofilament were detected by two-dimensional gel electrophoresis in cultures of pure sensory and sympathetic neurones derived from chick embryos. The identities of these neuronal intermediate filament proteins were confirmed by comparison of their molecular weights, isoelectric points, and peptide patterns from limited papain digestions with those of the corresponding proteins from fibroblasts and brain, respectively. A specific antibody to vimentin stained filamenteous structures and colcemid-induced coils in both neurones and associated satellite cells. In contrast, a specific antibody to the 70K neurofilament protein stained these structures solely in neurones. This neurone-specific staining, as well as its molecular weight and isoelectric point, distinguishes the 70K neurofilament protein from the 68K neurofilament as sociated protein described by others, which has been claimed to resemble the tubulin assembly protein.     

间甲酚及施磷对小麦间作蚕豆土壤微生物和酶活性的影响

通过盆栽试验,研究了不同磷水平下化感物质间甲酚对小麦间作蚕豆和单作小麦、单作蚕豆土壤微生物和酶活性的影响。结果表明,间甲酚对不同模式生长盛期细菌和微生物总数表现为化感促进作用,对真菌表现为化感抑制作用,随施磷量的增加间甲酚对土壤微生物的化感促进作用降低;不同模式生长盛期土壤微生物数量在施磷量为100mg／kg土的处理中最高,但成熟期施磷量为200mg／kg土的处理最高;间作较单作具有保持较高土壤细菌和微生物总数的作用,施磷水平越高间作增大微生物数量的效果越大;间甲酚对土壤微生物多样性具有明显降低作用,间作土壤的微生物多样性低于单作。间作具有较高的弱化间甲酚对土壤过氧化氢酶化感负效应的作用,施磷可增强土壤过氧化氢酶活性;磷素作用下土壤脲酶活性增强,间甲酚对单作蚕豆和间作土壤脲酶活性具有促进作用,但弱化了施磷对脲酶活性的增强作用;增施磷肥可弱化间甲酚对单作蚕豆和间作土壤酸性磷酸酶的化感负效应,对单作小麦土壤酸性磷酸酶活性的影响相反。间甲酚对不同模式土壤微生物和酶活性的影响在作物成熟期显著下降,说明随时间的推移土壤中间甲酚的作用力在不断弱化。     

川芎嗪对脑缺血/再灌注后所致肺损伤的影响

目的：观察川芎嗪对脑缺血／再灌注后肺损伤的影响。方法：采用Pulsinelli等的方法建立大鼠急性全脑缺血／再灌注模型。将Wistar大鼠随机分为三组,即：对照组（Control）、缺血／再灌注组（I／R）、川芎嗪＋缺血／再灌注组（TEP＋I／R）,分别测定各组肺功能（PaO2、PaCO2）,肺系数（LI％）、血浆和肺组织中与自由基有关物质的含量。结果：川芎嗪可有效改善脑缺血／再灌注后肺功能,减轻肺水肿,减少胞浆酶的漏出,增加自由基清除醇的活性,抑制组织脂质过氧化的发生。结论：川芎嗪对脑缺血／再灌注后肺损伤具有保护作用,其机制可能与其抗氧自由基和膜保护作用有关。     

丝氨酸内肽酶在黄瓜叶片衰老中的作用

采用丝氨酸内肽酶抑制剂和植物生长调节剂处理离体黄瓜叶片,研究了黄瓜叶片暗诱导衰老过程中丝氨酸内肽酶的作用。结果表明,6-BA50μmol／L与丝氨酸内肽酶抑制剂AEBSF能抑制叶片内肽酶活性的升高,延缓蛋白质降解,而ABA50μmol/L则促进了内肽酶活性的升高：其作用效果与AEBSF相反。活性电泳结果显示,黄瓜叶片中检测到6条内肽酶同工酶,其中4条（CEP2、3、4、6）为丝氨酸类型内肽酶,而ABA使丝氨酸内肽酶CEP2、3、4、6的活性明显增强,提示了丝氨酸类型内肽酶在黄瓜叶片衰老过程中具有重要作用。