Effects of small interfering RNA inhibit Class I phosphoinositide 3-kinase on human gastric cancer cells

AIM: To investigate the effects of small interfering RNA (siRNA)-mediated inhibition of Class I phosphoinositide 3-kinase (Class I PI3K) signal transduction on the proliferation, apoptosis, and autophagy of gastric cancer SGC7901 and MGC803 cells.

METHODS: We constructed the recombinant replication adenovirus PI3K(I)-RNA interference (RNAi)-green fluorescent protein (GFP) and control adenovirus NC-RNAi-GFP, and infected it into human gastric cancer cells. MTT assay was used to determine the growth rate of the gastric cancer cells. Activation of autophagy was monitored with monodansylcadaverine (MDC) staining after adenovirus PI3K(I)-RNAi-GFP and control adenovirus NC-RNAi-GFP treatment. Immunofluorescence staining was used to detect the expression of microtubule-associated protein 1 light chain 3 (LC3). Mitochondrial membrane potential was measured using the fluorescent probe JC-1. The expression of autophagy was monitored with MDC, LC3 staining, and transmission electron microscopy. Western blotting was used to detect p53, Beclin-1, Bcl-2, and LC3 protein expression in the culture supernatant.

RESULTS: The viability of gastric cancer cells was inhibited after siRNA targeting to the Class I PI3K blocked Class I PI3K signal pathway. MTT assays revealed that, after SGC7901 cancer cells were treated with adenovirus PI3K(I)-RNAi-GFP, the rate of inhibition reached 27.48% ± 2.71% at 24 h, 41.92% ± 2.02% at 48 h, and 50.85% ± 0.91% at 72 h. After MGC803 cancer cells were treated with adenovirus PI3K(I)-RNAi-GFP, the rate of inhibition reached 24.39% ± 0.93% at 24 h, 47.00% ± 0.87% at 48 h, and 70.30% ± 0.86% at 72 h (P < 0.05 compared to control group). It was determined that when 50 MOI, the transfection efficiency was 95% ± 2.4%. Adenovirus PI3K(I)-RNAi-GFP (50 MOI) induced mitochondrial dysfunction and activated cell apoptosis in SGC7901 cells, and the results described here prove that RNAi of Class I PI3K induced apoptosis in SGC7901 cells. The results showed that adenovirus PI3K(I)-RNAi-GFP transfection induced punctate distribution of LC3 immunoreactivity, indicating increased formation of autophagosomes. The results showed that the basal level of Beclin-1 and LC3 protein in SGC7901 cells was low. After incubating with adenovirus PI3K(I)-RNAi-GFP (50 MOI), Beclin-1, LC3, and p53 protein expression was significantly increased from 24 to 72 h. We also found that Bcl-2 protein expression down-regulated with the treatment of adenovirus PI3K(I)-RNAi-GFP (50 MOI). A number of isolated membranes, possibly derived from ribosome-free endoplasmic reticulum, were seen. These isolated membranes were elongated and curved to engulf a cytoplasmic fraction and organelles. We used transmission electron microscopy to identify ultrastructural changes in SGC7901 cells after adenovirus PI3K(I)-RNAi-GFP (50 MOI) treatment. Control cells showed a round shape and contained normal-looking organelles, nucleus, and chromatin, while adenovirus PI3K(I)-RNAi-GFP (50 MOI)-treated cells exhibited the typical signs of autophagy.

CONCLUSION: After the Class I PI3K signaling pathway has been blocked by siRNA, the proliferation of cells was inhibited and the apoptosis of gastric cancer cells was enhanced.

Allonocardiopsis opalescens gen. nov., sp. nov., a new member of the suborder Streptosporangineae , from the surface-sterilized fruit of a medicinal plant

An endophytic actinomycete, designated strain I10A-01259T, was isolated from a surface-sterilized fruit of Lonicera maackii (Rupr.) Maxim., a medicinal plant, which was collected from a suburb of Beijing, China. Whole-cell hydrolysates of the isolate contained galactose and meso-diaminopimelic acid. The predominant phospholipids were phosphatidylglycerol and diphosphatidylglycerol; the menaquinones consisted mainly of MK-9, MK-11 and MK-12, with a minor amount of MK-10. The major fatty acids were iso-C16 : 0, anteiso-C15 : 0 and iso-C15 : 0. Comparative analysis of 16S rRNA gene sequences indicated that strain I10A-01259T was most closely related to Nocardiopsis arabia S186T (93.2 % sequence similarity), Thermobifida halotolerans YIM 90462T (93.0 %) and other strains of genera within the families Nocardiopsaceae and Thermomonosporaceae . On the phylogenetic tree based on 16S rRNA gene sequences, strain I10A-01259T fell within the radius of the suborder Streptosporangineae , in which the strain formed a distinct lineage next to the genera of the families Nocardiopsaceae and Thermomonosporaceae . Based on the data from our polyphasic taxonomic study, a novel genus and species, Allonocardiopsis opalescens gen. nov., sp. nov., are proposed within the suborder Streptosporangineae . The type strain of Allonocardiopsis opalescens is strain I10A-01259T ( = CPCC 203428T  = DSM 45601T  = KCTC 19844T).

Nocardioides perillae sp. nov., isolated from surface-sterilized roots of Perilla frutescens

A Gram-stain-positive, rod-shaped actinobacterium, designated strain I10A-01402(T), was isolated from surface-sterilized roots of a medicinal plant, Perilla frutescens, collected in a suburb of Beijing, China. Chemotaxonomically, the strain contained ll-diaminopimelic acid as the diagnostic diamino acid and MK-8(H4) as the predominant menaquinone. The phospholipids were diphosphatidylglycerol, phosphatidylglycerol and phosphatidylinositol. The major fatty acids were C17 : 1ω9c, C18 : 1ω9c, C17 : 0, C16 : 0 and iso-C16 : 0. The genomic DNA G+C content was 70.4 mol%. 16S rRNA gene sequence analysis indicated that strain I10A-01402(T) belonged to the genus Nocardioides. Phylogenetic analyses based on 16S rRNA gene sequences showed that the isolate formed a robust cluster with Nocardioides ginsengisegetis Gsoil 485(T), N. koreensis MSL-09(T) and N. alkalitolerans KSL-1(T). On the basis of the evidence from our polyphasic taxonomic study, a novel species, Nocardioides perillae sp. nov., is proposed. The type strain is I10A-01402(T) ( = CPCC 203382(T)  = DSM 24552(T)  = KCTC 29022(T)).

Description of Belnapia rosea sp. nov. and emended description of the genus Belnapia Reddy et al. 2006

A novel alphaproteobacterial strain, designated CPCC 100156T, was isolated from a forest soil sample collected from Hainan Island, South China, and subjected to taxonomic investigation using a polyphasic approach. The pink- to rosy-coloured colonies on TSA and YM agar were smooth and moist. Good growth occurred at 28–32 °C and at pH 7.0–7.5. The respiratory quinone was ubiquinone-9. The polar lipids consisted of phosphatidylcholine (PC), hydroxyphosphatidylethanolamine (OH-PE), phosphatidylglycerol (PG), diphosphatidylglycerol (DPG) and two unidentified aminolipids (AL1, AL2), with a minor amount of ninhydrin-positive phosphoglycolipid. (NPG). The major cellular fatty acids were summed feature 8 (C18 : 1ω7c /C18 : 1ω6c) (49.5 %), summed feature 3 (C16 : 1ω7c/C16 : 1ω6c) (22.5 %), and C16 : 0 (14.0 %). The G+C content of the genomic DNA was 70.3 mol%. The organism showed 16S rRNA gene sequence similarity of 97.37 % with Belnapia moabensis DSM 16746T. Phylogenetic analyses based on 16S rRNA gene sequences showed that the isolate belonged to the family Acetobacteraceae and consistently formed a robust cluster with Belnapia moabensis DSM 16746T in the phylogenetic tree. The DNA–DNA hybridization value between the new isolate and Belnapia moabensis DSM 16746T was 45.6 %. On the basis of the taxonomic evidence, it is proposed that strain CPCC 100156T represents a novel species, for which the name Belnapia rosea sp. nov. is proposed. The type strain is CPCC 100156T ( = DSM 23312T = CGMCC 1.10758T). The description of the genus Belnapia is emended accordingly.

[Effects of combined therapy of LY294002 and SN50 on nude mice model with gastric cancer]

OBJECTIVE

To investigate the effect of phosphatidylinositol 3-kinase inhibitor LY294002 combined with NF-κB P65 nuclear translocation inhibitor SN50 on the tumor cell growth and apoptosis using a nude mouse model of gastric cancer.

METHODS

Human gastric cancer cell strain SGC7901 was transplanted subcutaneously to nude mice to establish tumor models. Model mice were randomly divided into the control group, the LY294002 treatment group, the SN50 treatment group, and the LY294002+SN50 treatment group, with 5 in each group. After being treated for 10 days, the inhibition rate of tumor growth was ascertained by measuring the size of tumor. Immunohistochemical method was used to detect the expression levels of Bcl-2, P53 and Bax proteins and transmission electron microscopy to investigate the apoptosis of tumor cells.

RESULTS

On the 10th day after treatment, the inhibition rate of gastric cancer cellular growth in the LY294002+SN50 group was (49.2±2.5)%, which was significantly higher than that in the LY294002 group(29.4±1.5)% and SN50 group (19.7±1.6)%(P<0.05). In comparison with the other two groups, LY294002+SN50 group exhibited more severe apoptosis, with expression of Bcl-2 decreased and that of P53 and Bax increased more significantly(P<0.05).

CONCLUSION

LY294002 combined with SN50 inhibits the growth of SGC7901 transplanted tumor and aggravates the apoptosis of gastric cancer cells in nude mice model.

Sinosporangium album gen. nov., sp. nov., a new member of the suborder Streptosporangineae

A Gram-positive, aerobic, non-motile actinobacterium, designated strain 6014T, was isolated from a soil sample collected from Qinghai province, north-west China, and subjected to a polyphasic taxonomic study. The isolate formed elementary branching hyphae and abundant aerial mycelia with globose sporangia on ISP 4 and R2A media. Whole-cell hydrolysates of strain 6014T contained arabinose, galactose and ribose as diagnostic sugars and meso-diaminopimelic acid as the diagnostic diamino acid. The polar lipids consisted of phosphatidylmethylethanolamine, phosphatidylethanolamine, hydroxy-phosphatidylethanolamine, N-acetylglucosamine-containing phospholipids, two unknown phospholipids and an unknown glycolipid. The menaquinone system contained MK-9(H2) and MK-9(H4). The major fatty acids were C14 : 0, i-C15 : 0, C16 : 0 and 10-methyl-C16 : 1. The genomic DNA G+C content of the isolate was 69.4 mol%. Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain 6014T fell within the radius of the suborder Streptosporangineae, in which the strain formed a distinct lineage next to genera of the family Streptosporangiaceae. Based on data from this polyphasic study, strain 6014T can be readily distinguished from previously described organisms and represents a member of a novel species within a new genus in the suborder Streptosporangineae. The name Sinosporangium album gen. nov., sp. nov. is proposed with 6014T (=DSM 45181T =KCTC 19655T) as the type strain.

In vivo antibacterial activity of nemonoxacin, a novel non-fluorinated quinolone

OBJECTIVES

To evaluate the in vivo antibacterial efficacy of nemonoxacin, a novel C8-methoxy non-fluorinated quinolone in murine systemic and local infection models.

METHODS

The efficacy of nemonoxacin in systemic infections was evaluated in mouse peritonitis models using isolates of methicillin-susceptible Staphylococcus aureus (MSSA, n=1), methicillin-resistant S. aureus (MRSA, n=1), methicillin- and levofloxacin-resistant Staphylococcus capitis (levofloxacin-resistant MRSC, n=1), penicillin-intermediate Streptococcus pneumoniae (PISP, n=1), penicillin-resistant S. pneumoniae (PRSP, n=2), Enterococcus faecalis (n=2, including 1 vancomycin-resistant Enterococcus, VRE) and Escherichia coli (n=3). The local infections included mouse pulmonary infections caused by PRSP (n=1), Klebsiella pneumoniae (n=1) and mouse ascending urinary tract infection caused by E. coli (n=1).

RESULTS

In the mouse systemic infection model, nemonoxacin demonstrated potent activity against MSSA (ED(50) =2.08 mg/kg), MRSA (ED(50) =2.59 mg/kg), levofloxacin-resistant MRSC (ED(50) =2.52 mg/kg), PISP (ED(50) =5.47 mg/kg), PRSP (ED(50) =3.68-5.28 mg/kg) and E. coli (ED(50) =3.13-5.28 mg/kg), and moderate activity towards E. faecalis infection (ED(50) =8.48-15.16 mg/kg). The therapeutic efficacy of nemonoxacin was significantly higher (P<0.01) than that of levofloxacin in infections caused by Gram-positive isolates (MSSA, MRSA, levofloxacin-resistant MRSC, PISP, PRSP and E. faecalis), but less potent than that of levofloxacin against E. coli infection (P<0.01). Nemonoxacin in vivo efficacy results with Gram-positive isolates (2- to 5-fold ED(50) advantage over levofloxacin) are consistent with the MIC data (4- to 16-fold MIC advantage of nemonoxacin over levofloxacin). In the mouse pulmonary infection model, nemonoxacin showed potent activity towards PRSP (higher than levofloxacin) and K. pneumoniae (lower than levofloxacin) infections. In the mouse ascending urinary tract infection model, nemonoxacin exhibited potent activity against E. coli infection (lower than levofloxacin).

CONCLUSIONS

The results validated the potent efficacy of nemonoxacin in vivo. The higher efficacy of nemonoxacin than of levofloxacin towards infections caused by Gram-positive cocci (especially MRSA, levofloxacin-resistant MRSC, PRSP and VRE) warrants investigation of its clinical use.

Amycolatopsis xylanica sp. nov., isolated from soil

An actinomycete, designated CPCC 202699T, was isolated from soil in Qinghai province, China, and its taxonomic status was established. Strain CPCC 202699Tcontainedmeso-diaminopimelic acid in its peptidoglycan, arabinose and galactose as the diagnostic sugars in whole-cell hydrolysates, a phospholipid pattern consisting mainly of phosphatidylethanolamine, phosphatidylmethylethanolamine and phosphatidylcholine, MK-9(H4) as the predominant menaquinone and iso-C16 : 0(18.8 %), iso-C15 : 0(18.1 %), iso-C14 : 0(14.2 %), C16 : 1cis9 (10.9 %) and C17 : 1cis9 (10.3 %) as the major fatty acids. In the phylogenetic tree based on 16S rRNA gene sequences, strain CPCC 202699Tformed a separate branch within the genusAmycolatopsis. However, strain CPCC 202699Tshowed low 16S rRNA gene sequence similarities (<97.0 %) with type strains of species with validly published names in the genusAmycolatopsis. On the basis of genotypic and phenotypic differences from the closest phylogenetic neighbours of strain CPCC 202699T, a novel species,Amycolatopsis xylanicasp. nov., is proposed. The type strain is CPCC 202699T(=DSM 45285T=KCTC 19581T=CCM 7627T).

Agromyces flavus sp. nov., an actinomycete isolated from soil

A gram-positive, non-motile strain, designated CPCC 202695(T), was isolated from a soil sample collected from the Qinghai-Tibet plateau, north-west China. Strain CPCC 202695(T) contained rhamnose, glucose and galactose in the cell wall as diagnostic sugars and 2,4-diaminobutyric acid, alanine, glutamic acid and glycine in the peptidoglycan. The polar lipids consisted of diphosphatidylglycerol, phosphatidylglycerol and two unknown glycolipids. MK-12 was the predominant menaquinone and anteiso-C(15 : 0) (34.2 %), iso-C(15 : 0) (19.8 %), iso-C(16 : 0) (12.7 %) and anteiso-C(17 : 0) (11.1 %) were the major fatty acids. 16S rRNA gene sequence similarities (94.2-97.1 %) between the isolate and the type strains of recognized species of the genus Agromyces indicated that strain CPCC 202695(T) was a member of the genus Agromyces. DNA-DNA relatedness clearly separated strain CPCC 202695(T) from its closest relatives. The phenotypic and genotypic data demonstrated that strain CPCC 202695(T) represents a novel species of the genus Agromyces, for which the name Agromyces flavus sp. nov. is proposed. The type strain is CPCC 202695(T) ( = KCTC 19578(T)  = CCM 7623(T)).

Geodermatophilus ruber sp. nov., isolated from rhizosphere soil of a medicinal plant

A novel actinobacterial strain, designated CPCC 201356(T), was isolated from a rhizosphere soil sample of the medicinal plant Astragalus membranaceus and subjected to a polyphasic taxonomic analysis. Good growth occurred at 20-32 °C, at pH 7.0-7.5 and with 0-1 % (w/v) NaCl. Colonies on R2A and ISP 2 agar were light red to red, round and lacked aerial mycelium; cells adhered to the agar. The peptidoglycan contained meso-diaminopimelic acid as the diagnostic diamino acid. The predominant menaquinones were MK-9(H(4)) and MK-9. Polar lipids consisted of diphosphatidylglycerol, phosphatidylethanolamine and two unknown phospholipids. The major cellular fatty acids were iso-C(16 : 0), iso-C(15 : 0) and C(17 : 1)ω8c. The G+C content of the genomic DNA was 72.8 mol%. Phylogenetic analyses based on 16S rRNA gene sequences showed that strain CPCC 201356(T) belonged to the family Geodermatophilaceae and consistently formed a distinct sub-branch with Geodermatophilus obscurus DSM 43160(T). The organism showed 16S rRNA gene sequence similarity of 97.7 % with G. obscurus DSM 43160(T). DNA-DNA hybridization between strain CPCC 201356(T) and G. obscurus DSM 43160(T) was 17.4 %. On the basis of evidence from this polyphasic taxonomic study, a novel species, Geodermatophilus ruber sp. nov., is proposed; the type strain is CPCC 201356(T) (=DSM 45317(T) =CCM 7619(T)).

Laceyella tengchongensis sp. nov., a thermophile isolated from soil of a volcano

A thermophilic strain, designated YIM 10002(T), was isolated from a soil sample of Big Empty Volcano in Tengchong county, Yunnan province, south-west China, and a polyphasic approach was used to investigate its taxonomic position. Strain YIM 10002(T) formed endospores on both aerial and substrate mycelia. Whole-cell hydrolysates contained meso-diaminopimelic acid, ribose, xylose and glucose. The major fatty acids were iso-C(15 : 0) and anteiso-C(15 : 0). The predominant menaquinone was MK-9. The polar lipids consisted of diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, phosphatidylinositol and phosphatidylinositol mannosides, together with some unknown phospholipids. The G+C content of its genomic DNA was 48.6 mol%. All of these chemotaxonomic data together with morphological characters consistently assigned strain YIM 10002(T) to the genus Laceyella. 16S rRNA gene sequence analysis showed that strain YIM 10002(T) was most closely related to Laceyella sacchari KCTC 9790(T) and Laceyella putida KCTC 3666(T) (99.9 and 98.0 % 16S rRNA gene sequence similarity, respectively). However, strain YIM 10002(T) showed relatively low DNA-DNA relatedness (34.0 and 39.0 %, respectively) with the above strains. Therefore, strain YIM 10002(T) represents a novel species of the genus Laceyella, for which the name Laceyella tengchongensis sp. nov. is proposed. The type strain is YIM 10002(T) (=DSM 45262(T) =CCTCC AA 208050(T)).

Alloactinosynnema album gen. nov., sp. nov., a member of the family Actinosynnemataceae isolated from soil

The taxonomic position of a Gram-stain-positive, aerobic strain, designated 03-9939(T), isolated from a soil sample collected from Xinjiang Province, China, was established using a polyphasic approach. Whole-cell hydrolysates of strain 03-9939(T) contained galactose and ribose as diagnostic sugars and meso-diaminopimelic acid as the diamino acid. The predominant menaquinone was MK-9(H4). The phospholipids consisted of diphosphatidylglycerol, phosphatidylglycerol and phosphatidylcholine. The major fatty acids were iso-C(16 : 0) (61.5 %) and iso-C(16 : 1) H (11.6 %). The genomic DNA G+C content was 68.2 mol%. Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain 03-9939(T) should be placed within the family Actinosynnemataceae, in which the strain formed a distinct lineage. Signature nucleotides in the 16S rRNA gene sequence showed that the strain contained a genus-specific diagnostic nucleotide signature pattern. The combination of phylogenetic analysis, phenotypic characteristics and chemotaxonomic data supported the conclusion that strain 03-9939(T) represents a novel species in a new genus of the family Actinosynnemataceae, for which the name Alloactinosynnema album gen. nov., sp. nov. is proposed. Strain 03-9939(T) (=DSM 45114(T) =KCTC 19294(T) =CCM 7461(T)) is the type strain of Alloactinosynnema album.

Liquid chromatography--mass spectrometry method for the determination of gliclazide in human plasma and application to a pharmacokinetic study of gliclazide sustained release tablets

A sensitive and selective liquid chromatographic--mass spectrometric (LC-MS) method for the determination of gliclazide (CAS 21187-98-4) in human plasma has been developed. Sample treatment was based on protein precipitation with acetonitrile. Analytical determination was carried out on a C18 column interfaced with a triple quadrupole mass spectrometer. Positive electrospray ionization was employed as the ionization source. The mobile phase was acetonitrile-water containing 10 mmol/l ammonium acetate, pH 3.5 adjusted with acetic acid (75:25) at the flow rate of 1.0 ml/min. Both the analyte and the internal standard glipizide (CAS 29094-61-9) were detected by use of selected ion monitoring mode. The method was linear in the concentration range of 0.025-2.5 microg/mL. The lower limit of quantification (LLOQ) was 0.025 microg/mL. The intra- and inter-day relative standard deviation across three validation runs over the entire concentration range was less than 9.8%. The accuracy determined at three concentrations (0.05, 0.2 and 1.5 microg/mL for gliclazide) was within +/- 10.11% in terms of relative error (RE). The method herein described was successfully applied for the evaluation of pharmacokinetic profiles of gliclazide sustained release tablets in 18 healthy volunteers. The results show that AUC, Tmax, Cmax and T1/2 between the test formulation and reference formulation have no significant difference (P > 0.05). Relative bioavailability is 96.7.4 +/- 12.9%.

Roseomonas vinacea sp. nov., a Gram-negative coccobacillus isolated from a soil sample

Strain CPCC 100056(T), which was isolated from a soil sample collected from the Qinghai-Tibet plateau, China, was subjected to a polyphasic taxonomic study. The organism was coccobacillus-shaped, non-motile and formed vinaceous colonies on ISP2 agar medium. The respiratory quinone was ubiquinone-10. The major fatty acids were C(18:1)omega7c and C(16:1)omega7c and/or C(16:1)omega6c. The G+C content of the genomic DNA was 67.3 mol%. A comparison of sequences in GenBank revealed that strain CPCC 100056(T) exhibited highest 16S rRNA gene sequence similarity (84.5-95.5%) with Roseomonas species. Strain CPCC 100056(T) could be distinguished from all Roseomonas species with validly published names by differences in phenotypic and genotypic properties. In view of the combined phenotypic, chemotaxonomic and phylogenetic data, strain CPCC 100056(T) should be classified as a representative of a novel species in the genus Roseomonas, Roseomonas vinacea sp. nov.; the type strain is CPCC 100056(T) (=KCTC 22045(T) =CCM 7468(T)).

Salinicoccus luteus sp. nov., isolated from a desert soil

A moderately halophilic bacterium, strain YIM 70202(T), was isolated from a desert soil sample collected from Egypt and was subjected to a taxonomic investigation. In a phylogenetic dendrogram based on 16S rRNA gene sequence analysis, strain YIM 70202(T) was affiliated to the Salinicoccus clade, showing 94.5-96.8 % 16S rRNA gene sequence similarity to the recognized species of the genus Salinicoccus, in which Salinicoccus roseus CCM 3516(T) was the nearest neighbour. The DNA-DNA relatedness value of the novel isolate with S. roseus CCM 3516(T) was 12.7 %. The novel isolate grew at temperatures between 4 and 45 degrees C and at pH values ranging from 7.0 to 11.0, with an optimum of 30 degrees C and pH 8.0-9.0, respectively. Strain YIM 70202(T) grew optimally in the presence of 10 % NaCl (w/v) and growth was observed at NaCl concentrations in the range 1-25 % (w/v). Chemotaxonomic data revealed that strain YIM 70202(T) contained MK-6 as the predominant respiratory quinone, possessed L-Lys-Gly(5) as the cell-wall peptidoglycan, had phosphatidylglycerol, diphosphatidylglycerol and an unknown glycolipid as the polar lipids and contained i-C(15 : 0) and ai-C(15 : 0) as the predominant fatty acids. The DNA G+C content was 49.7 mol%. The biochemical and chemotaxonomic properties demonstrate that strain YIM 70202(T) represents a novel species of the genus Salinicoccus. The name Salinicoccus luteus sp. nov. is proposed with strain YIM 70202(T) (=CGMCC 1.6511(T)=KCTC 3941(T)) as the type strain.

Zhihengliuella halotolerans gen. nov., sp. nov., a novel member of the family Micrococcaceae

The actinobacterial strain YIM 70185T was isolated from a saline soil sample collected from Qinghai province, north-west China, and subjected to a taxonomic investigation. Phylogenetic analysis based on 16S rRNA gene sequences revealed 93.5–96.4 % similarity to members of related genera in the family Micrococcaceae. In the phylogenetic dendrogram based on 16S rRNA gene sequence analysis, strain YIM 70185T formed a separate clade next to the genera Micrococcus and Citricoccus within the family Micrococcaceae. The peptidoglycan type was A4α, l-lys–l-ala–l-Glu. Cell-wall sugars contained glucose and tyvelose. The polar lipids were phosphatidylglycerol, diphosphatidylglycerol, phosphatidylinositol, an unknown phospholipid and an unknown glycolipid. The menaquinones were MK-9, MK-10 and MK-8 (molar ratio 5 : 2 : 1). The major fatty acids were ai-C15 : 0 and i-C15 : 0 and the DNA G+C content was 66.5 mol%. These chemotaxonomic profiles supported the assignment of strain YIM 70185T to a novel genus within the family Micrococcaceae. The name Zhihengliuella halotolerans gen. nov., sp. nov. is proposed. The type strain of Zhihengliuella halotolerans is YIM 70185T (=DSM 17364T=KCTC 19085T).

Deinococcus yunweiensis sp. nov., a gamma- and UV-radiation-resistant bacterium from China

A Gram-negative, non-spore-forming, non-motile, rod-shaped, red-pigmented strain, designated YIM 007T, was found as a contaminant on an agar plate in the laboratory of Yunnan Institute of Microbiology, China. The optimum growth pH and temperature for the isolate were 7.0–7.5 and 30 °C, respectively. The predominant respiratory quinone was MK-8. The polar lipid profile consisted mainly of various unknown phosphoglycolipids and glycolipids. The major cellular fatty acids were C16 : 1 ω7c, C16 : 0, C17 : 0 and C17 : 1 ω8c. l-Ornithine was detected in its peptidoglycan. The DNA G+C content was 64.1 mol%. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain YIM 007T showed 16S rRNA gene sequence similarity levels of 86.8–92.1 % to the other described Deinococcus species. Based on the high 16S rRNA gene sequence divergence and phenotypic differences, it is proposed that the unknown strain should be classified as a novel species in the genus Deinococcus with the name Deinococcus yunweiensis sp. nov. The type strain is YIM 007T (=KCTC 3962T=DSM 17005T).

Neuron-specific Bcl-2 homology 3 domain-only splice variant of Bak is anti-apoptotic in neurons, but pro-apoptotic in non-neuronal cells

We have identified and characterized N-Bak, a neuron-specific isoform of the pro-apoptotic Bcl-2 family member Bak. N-Bak is generated by neuron-specific splicing of a novel 20-base pair exon, which changes the previously described Bak, containing Bcl-2 homology (BH) domains BH1, BH2, and BH3, into a shorter BH3-only protein. As demonstrated by reverse transcription-polymerase chain reaction and RNase protection assay, N-Bak transcripts are expressed only in central and peripheral neurons, but not in other cells, whereas the previously described Bak is expressed ubiquitously, but not in neurons. Neonatal sympathetic neurons microinjected with N-Bak resisted apoptotic death caused by nerve growth factor (NGF) removal, whereas microinjected Bak accelerated NGF deprivation-induced death. Overexpressed Bak killed sympathetic neurons in the presence of NGF, whereas N-Bak did not. N-Bak was, however, still death-promoting when overexpressed in non-neuronal cells. Thus, N-Bak is an anti-apoptotic BH3-only protein, but only in the appropriate cellular environment. This is the first example of a neuron-specific Bcl-2 family member.

Interleukin 10 aggravates experimental autoimmune myasthenia gravis through inducing Th2 and B cell responses to AChR

The damage of acetylcholine receptor (AChR) at neuromuscular junctions of experimental autoimmune myasthenia gravis (EAMG), an animal model of human MG, is mediated by B cells which require T cell help. The Th2 associated cytokine IL-10 suppresses production of cytokines released by Th1 cells and is considered for treatment of human autoimmune diseases. To evaluate the role of IL-10 in EAMG, rhIL-10 was administered daily to Lewis rats by the subcutaneous route starting at the day of immunization and continued for 7 weeks. IL-10 failed to abrogate EAMG at low dose (0.1 or 1 microg/day) and at the dose of 3 microg/day caused earlier onset and aggravated clinical signs of EAMG when compared to EAMG rats injected with PBS only. Although Th1 responses reflected by AChR-induced lymphocyte proliferation and levels of IFN-gamma secreting cells, as well as AChR-induced Th1 cytokine mRNA expression was suppressed, augmented IL-4 mRNA expression and AChR-specific B cell responses may play an important role in the failure of IL-10 to abrogate EAMG. This study implicates a critical precaution in planning immunotherapy of IL-10 in antibody-mediated autoimmune diseases, e.g. MG.

[The bacteria detection and drug sensitivity test from infected root canals]

OBJECTIVE

To provide bacteriological basis for curing infected root canals with sensitive drugs.

METHODS

We have made bacterial cultivation for 56 cases with infected root canals and drug sensitive test with agar dilution.

RESULTS

The rates of bacteria detection and positive rates from infected root canals were high. Anaerobia and aerobia were sensitive to different kinds of antibiotics.

CONCLUSION

Bacteria have close relation to infected root canals. Sensitive drugs should be selected in clinical treatment.

The role of LY49 NK cell subsets in the regulation of murine cytomegalovirus infections

The distributions and functions of NK cell subsets, as defined by the expression of Ly49 NK cell receptors, were examined in murine CMV (MCMV)-infected mice. MCMV induced a reduction in NK1.1+ cell number in the spleen and an increase in the peritoneal exudate cells. Within the splenic NK1.1+ population, proportional increases in Ly49A+ and Ly49G2+ cells but decreases in Ly49C+ and Ly49D+ cells were observed 3 days post-MCMV infection, but within the peritoneal NK1.1+ cell populations there were proportional decreases in Ly49A+ cells and increases in Ly49C+, Ly49D+, and Ly49G2+ cells. Lymphocytic choriomeningitis virus did not elicit a comparable NK cell subset distribution. Lymphokine-activated killer cells were sorted into different Ly49 NK cell subsets and adoptively transferred into C57BL/6 suckling mice. Regulation of MCMV synthesis in these suckling mice was shown to be an IFN-gamma-dependent, perforin- and Cmv-1-independent process, and each NK cell subset mediated anti-viral activity. In adult C57BL/6 mice, the control of MCMV in the spleen is mediated by a perforin-dependent mechanism, regulated in part by the Cmv-1 gene, which maps closely to the Ly49 family. In vivo depletions of either one or two of the Ly49 subsets in adult mice did not affect the ability of the residual NK cells to regulate MCMV synthesis. These data provide evidence of NK cell subset distribution and function in MCMV infection, but no individual subset was required for the Cmv-1-like regulation of MCMV synthesis.

Oltipraz chemoprevention trial in Qidong, Jiangsu Province, People's Republic of China

Oltipraz has been used clinically in many regions of the world as an antischistosomal agent and is an effective inhibitor of aflatoxin hepatocarcinogenesis in rats. This chemopreventive action of oltipraz results primarily from an altered balance in aflatoxin metabolic activation and detoxication. In 1995, a randomized, placebo-controlled, double-blind intervention was conducted in residents of Qidong, People's Republic of China, who are at high risk for exposure to aflatoxin and development of hepatocellular carcinoma. The major study objectives were to define a dose and schedule for oltipraz that would reduce levels of aflatoxin biomarkers in biofluids of the participants, and to further characterize dose-limiting side effects. Two hundred thirty-four healthy eligible individuals, including those infected with HBV, were randomized to receive either 125 mg oltipraz daily, 500 mg oltipraz weekly, or placebo. Blood and urine specimens were collected to monitor potential toxicities and evaluate biomarkers over the 8-week intervention and subsequent 8-week follow-up periods. Overall, compliance in the intervention was excellent; approximately 85% of the participants completed the study. Objective evaluation of adverse events was greatly facilitated by inclusion of a placebo arm in the study design. A syndrome involving numbness, tingling, and pain in the fingertips was the only event that occurred more frequently among the active groups (18 and 14% of the daily 125 mg and weekly 500 mg arms, respectively) compared to placebo (3%). These symptoms were reversible and could be relieved with non-steroidal antiinflammatory agents. A more complete understanding of the chemopreventive utility of oltipraz awaits completion of an assessment of the efficacy of oltipraz in modulating levels of aflatoxin biomarkers.