The distribution of six biallelic polymorphisms on non-recombining segments of the Y-chromosome in five Chinese populations

Ancient demographic events can be inferred from the distribution of biallelic polymorphisms of NRY. In our study, six Y-biallelic markers were screened in 326 Y-chromosomes from five Chinese populations: Manchu, Fujian Han, Kazak, Bouyei and Sichuan Han. The chi2-test was performed using the SAS package. ARLEQUIN and SPSS programs were used for pairwise Fst's and genetic clusters, respectively. The M9 (G) and RPS4Y (T) polymorphisms show greater variance in these five populations and are informative and sensible in Chinese population genetic research, while the other four are less polymorphic. Significant differences in the distribution of the six biallelic markers were found between the three southern groups and the two northern groups involved in the present study. The Kazak population demonstrated marked differences not only from the southern populations, but differed notably from the other northern population, the Manchu. This result clearly suggests that the original division of the investigated groups into north and south would not yield optimal results from which useful generalizations could be made. The results have proven to be extremely useful, their analysis not only brought to light important new facts on the population structures, but supplied also useful guidelines for further additional Chinese population genetic research projects.     

Zinc coupling potentiates anti-HIV-1 activity of baicalin

Baicalin (BA) has been shown with anti-HIV-1 activity. Zinc is a nutrient element. The anti-HIV-1 activity of zinc complex of baicalin (BA-Zn) in vitro was studied and compared with the anti-HIV-1 activities between BA and BA-Zn in the present study. Our results suggested that BA-Zn has lower cytotoxicity and higher anti-HIV-1 activity compared with those of BA in vitro. The CC50s of BA-Zn and BA were 221.52 and 101.73 microM, respectively. The cytotoxicity of BA-Zn was about 1.2-fold lower than that of BA. The BA and BA-Zn inhibited HIV-1 induced syncytium formation, HIV-1 p24 antigen and HIV-1 RT production. The EC50s of BA-Zn on inhibiting HIV-1 induced syncytium formation (29.08 microM) and RT production (31.17 microM) were lower than those of BA (43.27 and 47.34 microM, respectively). BA-Zn was more effective than BA in inhibiting the activities of recombinant RT and HIV-1 entry into host cells. Zinc coupling enhanced the anti-HIV-1 activity of baicalin.     

Methylation profiling of urothelial carcinoma in bladder biopsy and urine

OBJECTIVE: To test DNA methylation profiling in detection of urothelial carcinoma in urine. STUDY DESIGN: Thirty-three bladder specimens were analyzed for the DNA p16INK4a, RASSF1, APC, GSTP, E-Cad and CyclinD2 genes to determine if there is a difference in gene methylation between benign and malignant cases. Urine samples were analyzed in a feasibility study. Finally, methylation profiles of urine samples were obtained and compared with follow-up biopsy diagnoses. RESULTS: We found methylated genes in 18% benign, 37% urothelial carcinoma in situ and 93% infiltrating urothelial carcinoma cases (p = 0.001). Methylation profiles from the 18 urine samples revealed a significantly higher prevalence of methylated genes in carcinoma cases than benign cases (100% vs. 50%, p = 0.025). We analyzed methylation profiles in 37 cytologically atypical urine samples with malignant or benign diagnosis on surgical follow-up andfound that only APC (55% in malignant vs. 0% in benign, p=0.025) and CyclinD2 were differentially methylated (35% in malignant vs. 0% in benign, p=0.2) while p14ARF, p16INK4a, RASSF1, GSTP and E-Cad had similar methylation profiles. CONCLUSION: These results suggest that methylation of p14ARF, p16INK4a, RASSF1, GSTP and E-Cad genes may not accurately identify carcinoma, but methylated APC and CyclinD2 might be useful biomarkers for urothelial carcinoma in urine.     

Synthesis and biological evaluation of 2′,5′-dimethoxychalcone derivatives as microtubule-targeted anticancer agents

A series of novel 2′,5′-dimethoxylchalcone derivatives including 18 new compounds were synthesized and evaluated for cytotoxicities against two human cancer cell lines, NTUB1 (human bladder cancer cell line) and PC3 (human prostate cancer cell line). All these derivatives except for 21 exhibited significant cytotoxic effect against NTUB1 and PC3 cell lines. Compounds 13 and 17 with 4-carbamoyl moiety showed potent inhibitory effect on growth of NTUB1 and PC3 cells. Flow cytometric analysis demonstrated that treatment of NTUB1 cells with 1 μM 13 and 17 induced G1 phase arrest accompanied by an increase in apoptotic cell death of NTUB1 cells after 24 h. Treatment of PC3 cells with 1 μM and 3 μM 13, and 1 μM and 3 μM 17 induced S and G1, and G1 and G2/M phase arrests, respectively, accompanied by an increase in apoptotic cell death. These data suggested that 13 and 17 with different 4-carbamoyl moiety displayed same cell cycle arrest in NTUB1 cells while different doses of 13 and 17 revealed different cell cycle arrest in PC3 cells. Cell morphological study of 17 indicated that more cells rounding up or dead associated with tubulin polymerization. Compound 17 showed an increased α-tubulin level in polymerized microtubule fraction in a dose-dependent manner while 500 nM paclitaxel also showed similar effect in NTUB1 cells by Western blot analysis. The result suggested that 17 may be used as microtubule-targeted agents.     

蓝猪耳小孢子发生和雄配子体发育

利用常规石蜡切片和超薄切片技术研究蓝猪耳(Torenia fournien)小孢子发生和雄配子体发育过程.蓝猪耳雄蕊4枚,花药具4个花粉囊.小孢子母细胞经减数分裂成四分体,其排列方式为四面体形或左右对称形.成熟花粉属2细胞型,具3个萌发孔.花药壁发育为双子叶型,腺质绒毡层.小孢子母细胞在四分体时期频繁出现细胞质降解的异常现象,其它发育阶段均正常;小孢子母细胞不正常的减数分裂可能导致花粉败育,这可能是蓝猪耳结实率低的原因之一.     

Neuraminidase Receptor Binding Variants of Human Influenza A(H3N2) Viruses Resulting from Substitution of Aspartic Acid 151 in the Catalytic Site: a Role in Virus Attachment?

Changes in the receptor binding characteristics of human H3N2 viruses have been evident from changes in the agglutination of different red blood cells (RBCs) and the reduced growth capacity of recently isolated viruses, particularly in embryonated eggs. An additional peculiarity of viruses circulating in 2005 to 2009 has been the poor inhibition of hemagglutination by postinfection ferret antisera for many viruses isolated in MDCK cells, including homologous reference viruses. This was shown not to be due to an antigenic change in hemagglutinin (HA) but was shown to be the result of a mutation in aspartic acid 151 of neuraminidase (NA) to glycine, asparagine, or alanine, which caused an oseltamivir-sensitive agglutination of RBCs. The D151G substitution was shown to cause a change in the specificity of NA such that it acquired the capacity to bind receptors, which were refractory to enzymatic cleavage, without altering its ability to remove receptors for HA. Thus, the inhibition of NA-dependent agglutination by the inclusion of oseltamivir carboxylate in the assay was effective in restoring the anti-HA specificity of the hemagglutination inhibition (HI) assay for monitoring antigenic changes in HA. Since the NA-dependent binding activity did not affect virus neutralization, and virus populations in clinical specimens possessed, at most, low levels of the “151 mutant,” the biological significance of this feature of NA in, for example, immune evasion is unclear. It is apparent, however, that an important role of aspartic acid 151 in the activity of NA may be to restrict the specificity of the NA interaction and its receptor-destroying activity to complement that of HA receptor binding.A characteristic feature of human influenza viruses is their frequent antigenic change to evade host immunity and cause recurrent annual epidemics of disease. As a consequence, available vaccines do not confer long-term immunity, and their composition is regularly reviewed by the WHO Global Influenza Surveillance Network (GISN) and updated to reflect changes in the antigenic characteristics of circulating viruses (2, 43).The two surface glycoproteins of the virus, hemagglutinin (HA) and neuraminidase (NA), perform clearly defined complementary roles in virus infection. Virus HA is responsible for the attachment of virus to sialic acid-containing glycoconjugates on susceptible cells, and it is antibody to HA, which neutralizes virus infectivity, that is of prime importance in immunity (37). Antibody to NA also contributes to the suppression of disease (3, 16). NA is responsible for destroying receptors for HA by removing the terminal sialic acid moieties from, and thereby inactivating, potentially inhibitory molecules such as mucins in the respiratory tract and from receptors on the surface of virus-infected cells to promote the release of progeny virus, thereby aiding virus transmission (1, 21, 26, 34). Thus, since NA may also cleave receptors from target cells, the maintenance of a balance between the receptor binding and receptor-destroying properties of HA and NA, respectively, is important in optimizing their respective functions in virus replication and maintaining epidemic potential (29, 41).Virus neutralization is principally the result of the inhibition of the attachment of HA to its receptor (9), and the hemagglutination inhibition (HI) assay is a simple and generally robust surrogate assay for monitoring antigenic relationships among viruses and is the principal basis for changes in vaccine composition recommended by the WHO (2, 43). Many mutations resulting in antibody escape cause amino acid substitutions close to the HA receptor binding site, which may influence receptor binding affinity and/or specificity as well as antigenicity (7, 37, 44). In turn, changes in receptor avidity and binding characteristics of HA, possibly associated with antigenic changes, may influence the effectiveness of the antibody inhibition of the agglutination of red blood cells (RBCs) in the standard HI assay and thereby complicate the interpretation of antigenic relationships (8, 12, 44).Antigenic drift among H3N2 viruses has been more muted in recent years. Whereas the antigenic drift of viruses between 1992 and 1997 required four changes in the H3N2 vaccine component, there was little progressive antigenic change in the HAs of A/Sydney/5/97(H3N2)-like viruses during the subsequent 5 years prior to the emergence of the A/Fujian/411/2002(H3N2)-like viruses (20) or among the more recently isolated A/Wisconsin/67/2005(H3N2)-like viruses between 2005 and 2009 (see below). Changes in the receptor binding characteristics of HA have been apparent from changes in the spectrum of RBCs agglutinated by the viruses, e.g., the loss of agglutination of chicken RBCs by H3N2 viruses circulating in the early 1990s (28, 31) and more recently by the poorer growth characteristics following the emergence of A/Fujian/411/2002-like viruses, particularly in embryonated eggs (22), which has “hampered” the selection of suitable vaccine candidates. Amino acid substitutions in residues 190 and 226 in the HA receptor binding site were implicated in the changes in hemagglutination (28, 31), while changes that increased the receptor binding of HA or decreased the enzyme activity of NA were shown to increase the growth of virus in eggs (22). Studies of differences among H3N2 viruses in their relative abilities to bind to and elute from RBCs of different species led Gulati et al. (11) to conclude that the more recently isolated Fujian/411/2002-like viruses bound different forms of sialic acid, which were not cleaved by the virus enzyme. However, studies using glycan arrays failed to identify any differences in receptor binding specificities, or in the amino acid sequences, of HAs that correlated with differences in hemagglutination (18).Another peculiar feature of many MDCK cell isolates of A/Wisconsin/67/2005-like viruses, isolated between 2005 and 2009, has been the poor inhibition of agglutination of turkey (and guinea pig) RBCs by reference postinfection ferret antisera, with the consequent difficulty in interpreting antigenic relationships from HI data (as reported herein). Here we describe the results of a series of experiments that demonstrate that this phenomenon is not due to changes in antigenicity or simply to changes in HA receptor binding but is the result of the selection in MDCK cells of changes in NA that promote NA-dependent, NA inhibitor-sensitive hemagglutination, which is refractory to inhibition by anti-HA antibody. The replacement of aspartic acid 151 of NA by glycine, which did not affect significantly the activity of the enzyme or its ability to remove receptors for HA, was shown to alter the specificity of NA, resulting in the attachment of virus via its NA to sialic acid receptors refractory to catalytic cleavage.     

The cannabinoid WIN55,212-2 protects against oxidized LDL-induced inflammatory response in murine macrophages

The endocannabinoid system has recently been attracted interest for its anti-inflammatory and anti-oxidative properties. In this study, we investigated the role of the endocannabinoid system in regulating the oxidized low-density lipoprotein (oxLDL)-induced inflammatory response in macrophages. RAW264.7 mouse macrophages and peritoneal macrophages isolated from Sprague-Dawley (SD) rats were exposed to oxLDL with or without the synthetic cannabinoid WIN55,212-2. To assess the inflammatory response, reactive oxygen species (ROS) and tumor necrosis factor alpha (TNF- α) levels were determined, and activation of the mitogen-activated protein kinase (MAPK) and nuclear factor (NF)-kappa B signaling pathways were assessed. We observed that: i) oxLDL strongly induced ROS generation and TNF- α secretion in murine macrophages; ii) oxLDL-induced TNF- α and ROS levels could be lowered considerably by WIN55,212-2 via inhibition of MAPK (ERK1/2) signaling and NF-kappa B activity; and iii) the effects of WIN55212-2 were attenuated by the selective CB2 receptor antagonist AM630. These results demonstrate the involvement of the endocannabinoid system in regulating the oxLDL-induced inflammatory response in macrophages, and indicate that the CB2 receptor may offer a novel pharmaceutical target for treating atherosclerosis.     

Synthesis and characterization of quaternized β-chitin

Water-soluble 2′-O-hydroxypropyltrimethylammoniumchitin chloride (2′-O-HTACCt) was prepared directly from β-chitin and 3-chloro-2-hydroxypropyltrimethylammonium chloride (CTA) in basic medium. The effect of alkali concentration, reaction temperature, reaction time, and dosage of CTA on yield and degree of substitution (DS) of 2′-O-HTACCt were studied. These quaternized chitin derivatives were characterized by FTIR and ¹H NMR spectroscopy, conductometric titration, and elemental analysis methods. Research results indicate that β-chitin can react directly with CTA to produce a water-soluble 2′-O-HTACCt derivative with a high DS. The optimal preparation conditions were determined to be 35-40 wt % (aq NaOH), 40 °C (reaction temperature), 6 h (reaction time), and 4 (molar ratio of CTA to β-chitin unit).     

TFPI or uPA-PAI-1 complex affect cell function through expression variation of type II very low density lipoprotein receptor

Very low density lipoprotein receptors (VLDLR) including type I and type II are known to affect cell functions by binding to its extracellular ligands. However, the effect of these ligands on VLDLR expression remains elusive. Tissue factor pathway inhibitor (TFPI) and urokinase plasminogen activator and plasminogen activator inhibitor 1 (uPA-PAI-1) complex, two ligands of VLDLR, were used to examine their effects on VLDLR expression. TFPI treatment decreased type II VLDLR expression, inhibited cell proliferation and migration, and degradated β-catenin in SGC7901 cells. However, uPA-PAI-1 complex, increased type II VLDLR expression with promoted cell proliferation and migration and stabilization of β-catenin. These results indicated that extracellular ligands can change the expression of type II VLDLR to affect cell proliferation and migration.