当归注射液对脑血栓患者花生四烯酸代谢产物和氧自由基水平的影响

目的 :了解当归注射液改善脑循环治疗脑血栓的临床效果。方法 :对 46例脑血栓形成患者应用当归注射液进行治疗 ,对比分析其治疗前后血浆前列环素 (PGI2 )、血栓烷A2 (TXA2 )及自由基水平。结果 :脑血栓形成患者TXA2 、丙二醛 (MDA)明显升高 ,超氧化物岐化酶 (SOD)明显降低。当归注射液治疗后上述改变明显减轻或恢复至正常组水平。结论 :当归注射液能有效调节花生四烯酸代谢产物和氧自由基水平 ,对治疗脑血栓效果明显。     

Characterization of an IgA receptor from group B streptococci: specificity for serum IgA

Some strains of group B streptococci express a cell surface protein which binds IgA. This report describes some properties of such an IgA receptor and compares it with a previously described IgA receptor from group A streptococci. The group B receptor was released in an almost pure form from bacteria incubated at elevated pH, and could be isolated by IgA-Sepharose affinity chromatography. The sequence of the N-terminal 19 amino acid residues was unique. The receptor preferentially binds IgA of human origin, as shown in immunoblotting experiments with purified IgA from nine different species. The affinity constant of the purified receptor for serum IgA was determined to be 3.5 x 10(8) M-1, but for secretory IgA it was too low to allow determination. This result indicates that secretory component and/or J chain interferes with the binding of IgA to this type of bacterial receptor, which may be one of the physiological functions of these polypeptides. A reduction in affinity was also observed for another complexed form of IgA, alpha 1-microglobulin-IgA. The group B receptor is antigenically unrelated to the IgA receptor from group A streptococci (protein Arp), but competitive inhibition experiments indicate that they bind to the same region in IgA. The implications of these findings, and the biological role of bacterial IgA receptors, are discussed.     

Affinity fractionation of lymphocytes using a monolithic cryogel

A new type of continuous, supermacroporous, monolithic, cryogel affinity adsorbent was developed, allowing specific fractionation and separation of human peripheral blood lymphocytes in a chromatographic format. The affinity adsorbent was used to design a novel cell separation strategy, which was based on the interaction of protein A from Staphylococcus aureus with cells bearing IgG antibodies on the surface. After treating lymphocytes with goat anti-human IgG(H+L), the IgG-positive B-lymphocytes were efficiently separated from T-lymphocytes. Protein A covalently coupled to epoxy activated dimethylacrylamide (DMAA) cryogel matrix specifically bound IgG-bearing B-lymphocytes through the Fc region, while non-bound T-lymphocytes passed through the column. More than 90% of the B-lymphocytes were retained in the column while the cells in the breakthrough fraction were enriched in T-lymphocytes (81%). The viability of the T-lymphocytes isolated was greater than 90%. The bound lymphocytes released by human or dog IgG recovered 60-70% of the B-cells without significantly impairing the cell viability. The technique can be applied in general to cell separation systems where IgG antibodies against specific cell surface markers are available.     

动脉粥样硬化斑块中内皮素生成及分布的免疫组织化学观察

应用免疫组化方法对人动脉粥样硬化（ＡＳ）斑块中内皮素（ＥＴ）进行分析，发现除内皮细胞外，增生的平滑肌细胞（ＳＭＣ）中也含有大量的内皮素；在内皮剥脱的大鼠胸主动脉，增生的内膜ＳＭＣ能产生丰富的内皮素。内皮素放射免疫测定证实ＳＭＣ增生的活跃程度与内皮素量呈正比。提示内皮素合成增多与ＡＳ斑块内ＳＭＣ增生关系密切。     

Effects of Na+, K+ and Mg2+ on45Ca2+ uptake by pancreatic islets

Microdissected pancreatic islets of noninbredob/ob-mice were used to study ionic effects on the lanthanum-nondisplaceable⁴⁵Ca²⁺ uptake by islet cells. Omission of Mg²⁺ from the incubation medium had no effect, but the⁴⁵Ca²⁺ uptake was increased by omission of Na⁺ and decreased by omission of K⁺. Excess Mg²⁺ (1.2–15 mM) inhibited and excess K⁺ (4.7–25 mM) stimulated the⁴⁵Ca²⁺ uptake in a concentration-dependent manner. Stimulation of⁴⁵Ca²⁺ uptake in Na⁺-deficient islets was associated with an enhancement of the basal insulin release. Total abolishment of glucose-stimulated⁴⁵Ca²⁺ uptake in K⁺-deficient islets did not preclude a significant secretory response to glucose. It is concluded that the lanthanum-nondisplaceable⁴⁵Ca²⁺ uptake shows a partial correlation to insulin release.     

P2X receptors in trigeminal subnucleus caudalis modulate central sensitization in trigeminal subnucleus oralis

This study investigated the role of trigeminal subnucleus caudalis (Vc) P2X receptors in the mediation of central sensitization induced in nociceptive neurons in subnucleus oralis (Vo) by mustard oil (MO) application to the tooth pulp in anesthetized rats. MO application produced a long-lasting central sensitization reflected in neuroplastic changes (i.e., increases in neuronal mechanoreceptive field size and responses to innocuous and noxious mechanical stimuli) in Vo nociceptive neurons. Twenty minutes after MO application, the intrathecal (i.t.) administration to the rostral Vc of the selective P2X(1), P2X(3), and P2X(2/3) receptor antagonist, 2'-(or 3'-)O-trinitrophenyl-ATP (TNP-ATP), significantly and reversibly attenuated the MO-induced central sensitization for more than 15 min; saline administration had no effect. Administration to the rostral Vc of the selective P2X(1), P2X(3), and P2X(2/3) receptor agonist, alpha,beta-methylene ATP (alpha,beta-meATP, i.t.) produced abrupt and significant neuroplastic changes in Vo nociceptive neurons, followed by neuronal desensitization as evidenced by the ineffectiveness of a second i.t. application of alpha,beta-meATP and subsequent MO application to the pulp. Administration to the rostral Vc of the selective P2X(1) receptor agonist beta,gamma-methylene ATP (beta,gamma-meATP, i.t.) produced no significant neuroplastic changes per se and did not affect the subsequent MO-induced neuroplastic changes in Vo nociceptive neurons. These results suggest that P2X(3) and possibly also the P2X(2/3) receptor subtypes in Vc may play a role in the initiation and maintenance of central sensitization in Vo nociceptive neurons induced by MO application to the pulp.     

Intratracheal administration of liposomal clodronate accelerates alveolar macrophage reconstitution following fetal liver transplantation

To facilitate study of alveolar macrophages in vivo, we developed a method to rapidly and efficiently replace resident alveolar macrophages with macrophages of a different (donor) genotype. Chimeric mice were generated by lethal irradiation followed by fetal liver transplantation (FLT) using green fluorescent protein (GFP) transgenic reporter mice as donors. Kinetics of peripheral blood monocyte (PBM) and alveolar macrophage reconstitution was determined 4 and 10 weeks post-FLT by quantifying the percentage of GFP+ cells. To enhance the recruitment of donor monocytes into the lung after FLT, mice were treated with intratracheal administration of liposomal clodronate to deplete host alveolar macrophages at 6 weeks post-FLT. PBM reconstitution occurred by 4 weeks after FLT (85.7+/-1.6% of CD11b+/Gr-1+ monocytes were GFP+), and minimal alveolar macrophage repopulation was observed (9.5% GFP+). By 10 weeks following FLT, 48% of alveolar macrophages were GFP+ by immunostaining of macrophages on lung tissue sections, and 55.1 +/- 1.6% of lung lavage macrophages were GFP+ by fluorescein-activated cell sorter analysis. Clodronate treatment resulted in a significant increase in GFP+ alveolar macrophages 10 weeks after FLT. By immunostaining, 90% of macrophages were GFP+ on lung tissue sections and 87.5 +/- 1.1% GFP+ in lung lavage (compared with GFP-transgenic controls). The ability of newly recruited alveolar macrophages to clear Pseudomonas aeruginosa and activate nuclear factor-kappaB in response to Eschericia coli lipopolysaccharide demonstrated normal macrophage function. Optimizing this methodology provides an important tool for the study of specific genes and their contribution to alveolar macrophage function in vivo.     

Studies on the Histamine Releasing Effect of Bee Venom Fractions and Compound 48/80 on Skin and Lung Tissue of the Rat

Two bee venom fractions, F I and F II, obtained by gel filtration, and compound 48/80, were shown to release histamine from skin and lung tissue of the rat. F I is the phosphatidase A containing fraction, and F II contains a basic polypeptide. Dose-response relationships, the time course of the histamine release, and the influence of enzyme inhibitors were studied. The results with F II and compound 48/80 were similar, suggesting that the two substances activate the same kind of release mechanism. It is concluded that F II is not related to the earlier described bee venom polypeptides melittin and aparnin. The mode of action of phosphatidase A was distinctly different from that of F II or compound 48/80. The results are consistent with the assumption that it acts in a “non-specific.” way by hydrolysing tissue phosphatides to lyso compounds, which in turn damage the tissue.     

Detecting Candida albicans in human milk

Procedures for diagnosis of mammary candidosis, including laboratory confirmation, are not well defined. Lactoferrin present in human milk can inhibit growth of Candida albicans, thereby limiting the ability to detect yeast infections. The inhibitory effect of various lactoferrin concentrations on the growth of C. albicans in whole human milk was studied. The addition of iron to the milk led to a two- to threefold increase in cell counts when milk contained 3.0 mg of lactoferrin/ml and markedly reduced the likelihood of false-negative culture results. This method may provide the necessary objective support needed for diagnosis of mammary candidosis.     

Nucleolar localization of non-structural protein 3b, a protein specifically encoded by the severe acute respiratory syndrome coronavirus

The open reading frame 3 (ORF3) of the severe acute respiratory syndrome coronavirus (SARS-CoV) genome encodes a predicted 154-amino acid protein, which lacks similarities to any known protein, and is named 3b. In this study, it was shown that 3b protein was predominately localized to nucleus with EGFP tag at its N- or C-terminus. The localization patterns were similar in different transfected cells. Immuno-fluorescence assay revealed that 3b protein was co-localized well with C23 in nucleolus. C23, B23 and fibrillarin all are important nucleolar proteins, which localize in the region of the nucleolus. Co-transfection of p3b-EGFP with pC23-DsRed, pB23-DsRed and pfibrillarin-DsRed further confirmed 3b's nucleolus localization. With construction of serial truncated mutants of 3b, a region (residues 134-154 aa) responsible for nucleolar localization was determinated in 3b protein. These results provide a new insight for further functional studies of SARS-CoV 3b protein.