Resolving intravoxel fiber architecture using nonconvex regularized blind compressed sensing

In diffusion magnetic resonance imaging, accurate and reliable estimation of intravoxel fiber architectures is a major prerequisite for tractography algorithms or any other derived statistical analysis. Several methods have been proposed that estimate intravoxel fiber architectures using low angular resolution acquisitions owing to their shorter acquisition time and relatively low b-values. But these methods are highly sensitive to noise. In this work, we propose a nonconvex regularized blind compressed sensing approach to estimate intravoxel fiber architectures in low angular resolution acquisitions. The method models diffusion-weighted (DW) signals as a sparse linear combination of unfixed reconstruction basis functions and introduces a nonconvex regularizer to enhance the noise immunity. We present a general solving framework to simultaneously estimate the sparse coefficients and the reconstruction basis. Experiments on synthetic, phantom, and real human brain DW images demonstrate the superiority of the proposed approach.

Advances in the research of AMPK and its subunit genes

AMP-activated kinase (AMPK) is a heterotrimeric complex composed of three subunits and is the core energy sensor of the cell. The AMPK activity is important for survival during periods of stress and starvation and also has implications in type II diabetes, obesity, metabolic syndrome, longevity and cancer, etc. The activation of AMPK is triggered through binding of Adenosine Monophosphate Activated Proteins (AMP) to the Bateman domains of the gamma subunit, leading to increased phosphorylation of the threonine 172 on the alpha subunit by inducing allosteric activation and inhibiting dephosphorylation. AMPK and its subunits have been the focuses of many researchers dealing with genetic and metabolic issues. The study makes a comprehensive review on the structure, function, distribution, enzyme activity, the genetic mutation and other aspects of AMPK and its subunit genes, with the aim to outline main aspects of present researches on AMPK and its subunits in animal genetics.

Interactions of several single nucleotide polymorphisms and high body mass index on serum lipid traits

The interactions between single nucleotide polymorphisms (SNPs) and high body mass index (BMI) on serum lipid profiles are limited. This study was undertaken to detect the interactions of 10 SNPs and high BMI on serum lipid traits in an isolated population. A total of 978 normal BMI (< 24 kg/m2) and 751 high BMI (≥ 24 kg/m2) subjects of Bai Ku Yao were randomly selected from our previous stratified randomized cluster samples. Genotypes of rs2066715, rs1044925, low density lipoprotein receptor (LDL-R) Ava||, rs2070895, rs2000813, rs1801133, rs3757354, rs505151, rs2016520, and rs5888 SNPs were determined by polymerase chain reaction and restriction fragment length polymorphism combined with gel electrophoresis, and then confirmed by direct sequencing. The interactions were detected by factorial design covariance analysis. The genotypic and allelic frequencies of rs2070895 and rs505151 were different between normal and high BMI subjects, the genotypic frequency of rs2000813 and allelic frequency of rs3757354 were also different between normal and high BMI subjects (P < 0.01). The levels of total cholesterol (TC), apolipoprotein (Apo) A1 (rs2066715); TC, low-density lipoprotein cholesterol (LDL-C), ApoA1, ApoB, and ApoA1/ApoB (rs2070895); triglyceride (TG), high-density lipoprotein cholesterol (HDL-C), and ApoA1 (rs2000813); TC, HDL-C, LDL-C, ApoA1, and ApoB (rs1801133); HDL-C and ApoA1 (rs3757354) in normal BMI subjects were different among the genotypes (P < 0.01). The levels of LDL-C, ApoB, and ApoA1/ApoB (rs2066715); HDL-C, ApoA1, ApoB, and ApoA1/ApoB (rs2070895); TC, HDL-C, ApoA1, and ApoB (rs2000813); TC, TG, HDL-C, LDL-C, ApoA1, and ApoB (rs1801133); TC, TG, and ApoB (rs3757354); TG (rs505151); TG and ApoA1 and ApoB (rs2016520); and TC, HDL-C, LDL-C, ApoA1, and ApoB (rs5888) in high BMI subjects were also different among the genotypes (P < 0.01). The SNPs of rs2066715 (LDL-C and ApoA1/ApoB); rs2070895 (TC, LDL-C, ApoA1, and ApoB); rs2000813 (ApoB); rs1801133 (TC, TG, and LDL-C); rs3757354 (TC and TG); rs505151 (TG, HDL-C, ApoB, and ApoA1/ApoB); rs2016520 (TG and ApoA1/ApoB); and rs5888 (TG, ApoA1, and ApoB) interacted with high BMI to influence serum lipid levels (P < 0.01). The differences in serum lipid levels between normal and high BMI subjects might partly result from different interactions of several SNPs and high BMI.

Several genetic polymorphisms interact with overweight/obesity to influence serum lipid levels

Background

Information about the interactions of single nucleotide polymorphisms (SNPs) and overweight/obesity on serum lipid profiles is still scarce. The present study was undertaken to detect ten SNPs and their interactions with overweight/obesity on serum lipid levels.

Methods

A total of 978 normal weight and 751 overweight/obese subjects of Bai Ku Yao were randomly selected from our previous stratified randomized cluster samples. Normal weight, overweight and obesity were defined as a body mass index (BMI) < 24, 24–28, and > 28 kg/m²; respectively. Serum total cholesterol (TC), triglyceride (TG), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), apolipoprotein (Apo) A1 and ApoB levels were measured. Genotyping of ATP-binding cassette transporter A1 (ABCA-1) V825I, acyl-CoA:cholesterol acyltransferase-1 (ACAT-1) rs1044925, low density lipoprotein receptor (LDL-R) AvaII, hepatic lipase gene (LIPC) -250G>A, endothelial lipase gene (LIPG) 584C>T, methylenetetrahydrofolate reductase (MTHFR) 677C>T, the E3 ubiquitin ligase myosin regulatory light chain-interacting protein (MYLIP) rs3757354, proprotein convertase subtilisin-like kexin type 9 (PCSK9) E670G, peroxisome proliferator-activated receptor delta (PPARD) +294T>C, and Scavenger receptor class B type 1 (SCARB1) rs5888 was performed by polymerase chain reaction and restriction fragment length polymorphism combined with gel electrophoresis, and then confirmed by direct sequencing. The interactions were detected by factorial design covariance analysis.

Results

The genotypic and allelic frequencies of LIPC and PCSK9 were different between normal weight and overweight/obese subjects, the genotypic frequency of LIPG and allelic frequency of MYLIP were also different between normal weight and overweight/obese subjects (P < 0.05-0.001). The levels of TC, ApoA1 (ABCA-1); TC, LDL-C, ApoA1, ApoB and ApoA1/ApoB (LIPC); TG, HDL-C, and ApoA1 (LIPG); TC, HDL-C, LDL-C, ApoA1 and ApoB (MTHFR); HDL-C and ApoA1 (MYLIP) in normal weight subjects were different among the genotypes (P < 0.01-0.001). The levels of LDL-C, ApoB and ApoA1/ApoB (ABCA-1); HDL-C, ApoA1, ApoB and ApoA1/ApoB (LIPC); TC, HDL-C, ApoA1 and ApoB (LIPG); TC, TG, HDL-C, LDL-C, ApoA1 and ApoB (MTHFR); TC, TG and ApoB (MYLIP); TG (PCSK9); TG, ApoA1 and ApoB (PPARD); and TC, HDL-C, LDL-C, ApoA1 and ApoB (SCARB1) in overweight/obese subjects were different among the genotypes (P < 0.01-0.001). The SNPs of ABCA-1 (LDL-C and ApoA1/ApoB); LIPC (TC, LDL-C, ApoA1 and ApoB); LIPG (ApoB); MTHFR (TC, TG and LDL-C); MYLIP (TC and TG); PCSK9 (TG, HDL-C, ApoB and ApoA1/ApoB); PPARD (TG and ApoA1/ApoB); and SCARB1 (TG, ApoA1 and ApoB) interacted with overweight/obesity to influence serum lipid levels (P < 0.05-0.001).

Conclusions

The differences in serum lipid levels between normal weight and overweight/obese subjects might partly result from different genetic polymorphisms and the interactions between several SNPs and overweight/obesity.

Interactions of several lipid-related gene polymorphisms and cigarette smoking on blood pressure levels

The interactions of single nucleotide polymorphisms (SNPs) and cigarette smoking on blood pressure levels are limited. The present study was undertaken to detect nine lipid-related SNPs and their interactions with cigarette smoking on blood pressure levels. Genotyping of ATP-binding cassette transporter A1 (ABCA-1) V825I, acyl-CoA:cholesterol acyltransferase-1 (ACAT-1) rs1044925, low density lipoprotein receptor (LDL-R) AvaⅡ, hepatic lipase gene (LIPC) -250G>A, endothelial lipase gene (LIPG) 584C>T, methylenetetrahydrofolate reductase (MTHFR) 677C>T, proprotein convertase subtilisin-like kexin type 9 (PCSK9) E670G, peroxisome proliferator-activated receptor delta (PPARD) +294T>C, and Scavenger receptor class B type 1 (SCARB1) rs5888 was performed in 935 nonsmokers and 845 smokers. The interactions were detected by factorial regression analysis. The frequencies of genotypes (ACAT-1 and LIPG), alleles (ABCA-1), and both genotypes and alleles (LDL-R, LIPC, PPARD and SCARB1) were different between nonsmokers and smokers (P < 0.05-0.001). The levels of pulse pressure (PP, ABCA-1), and systolic, diastolic blood pressure (SBP, DBP) and PP (LIPC) in nonsmokers were different among the genotypes (P < 0.01-0.001). The levels of SBP (ABCA-1, ACAT-1, LIPG and PCSK9), DBP (ACAT-1, LDL-R, LIPC, PCSK9 and PPARD), and PP (LIPC, LIPG, MTHFR and PCSK9) in smokers were different among the genotypes (P < 0.01-0.001). The SNPs of ABCA-1, ACAT-1 and PCSK9; ACAT-1, LDL-R, MTHFR and PCSK9; and ABCA-1, LIPC, PCSK9 and PPARD were shown interactions with cigarette smoking to influence SBP, DBP and PP levels (P < 0.05-0.001); respectively. The differences in blood pressure levels between the nonsmokers and smokers might partly result from different interactions of several SNPs and cigarette smoking.

Interactions of the LIPG 584C>T polymorphism and alcohol consumption on serum lipid levels

Both endothelial lipase gene (LIPG) 584C>T (rs2000813) polymorphism and alcohol consumption modulate serum lipid levels. But their interactions on serum lipid profiles are not well known. The present study was undertaken to detect the interactions of LIPG 584C>T polymorphism and alcohol consumption on serum lipid levels. Genotyping of the LIPG 584C>T was performed in 763 unrelated nondrinkers and 520 drinkers aged 15-85 years. The levels of serum total cholesterol (TC), triglyceride (TG), high-density lipoprotein cholesterol (HDL-C), apolipoprotein (Apo) AI, and the ratio of ApoAI to ApoB were higher in drinkers than in nondrinkers (P<.01 for all). There were no significant differences in the genotypic and allelic frequencies between nondrinkers and drinkers. The levels of TC, HDL-C, and ApoAI in nondrinkers were different among the three genotypes (P<.05-.01), the subjects with CT genotype had higher TC, HDL-C, and ApoAI levels than the subjects with CC genotype. The levels of HDL-C and ApoAI in drinkers were different among the three genotypes (P<.001 and P<.05; respectively), the individuals with TT genotype had higher HDL-C and ApoAI levels than the individuals with CT and CC genotypes. The interactions between LIPG 584C>T genotypes and alcohol consumption on serum HDL-C (P<.01) and ApoAI levels (P<.05) were also detected by using a factorial regression analysis after controlling for potential confounders. The levels of TC in nondrinkers were correlated with LIPG 584C>T alleles (P<.05), whereas the levels of TG and HDL-C were associated with LIPG 584C>T alleles (P<.05) and genotypes (P<.05), respectively. These results suggest that the subjects with TT genotype benefit more from alcohol consumption than the subjects with CT and CC genotypes in increasing serum HDL-C and ApoAI levels.

Interactions of the apolipoprotein A5 gene polymorphisms and alcohol consumption on serum lipid levels

BACKGROUND

Little is known about the interactions of apolipoprotein (Apo) A5 gene polymorphisms and alcohol consumption on serum lipid profiles. The present study was undertaken to detect the interactions of ApoA5-1131T>C, c.553G>T and c.457G>A polymorphisms and alcohol consumption on serum lipid levels.

METHODOLOGY/PRINCIPAL FINDINGS

A total of 516 nondrinkers and 514 drinkers were randomly selected from our previous stratified randomized cluster samples. Genotyping was performed by polymerase chain reaction and restriction fragment length polymorphism. The levels of serum total cholesterol (TC), triglyceride (TG), high-density lipoprotein cholesterol (HDL-C), ApoA1 and ApoB were higher in drinkers than in nondrinkers (P<0.05-0.001). The genotypic and allelic frequencies of three loci were not different between the two groups. The interactions between -1131T>C genotypes and alcohol consumption on ApoB levels (P<0.05) and the ApoA1/ApoB ratio (P<0.01), between c.553G>T genotypes and alcohol consumption on low-density lipoprotein cholesterol (LDL-C) levels (P<0.05) and the ApoA1/ApoB ratio (P<0.05), and between c.457G>A genotypes and alcohol consumption on TG levels (P<0.001) were detected by factorial regression analysis after controlling for potential confounders. Four haplotypes (T-G-G, C-G-G, T-A-G and C-G-T) had frequencies ranging from 0.06 to 0.87. Three haplotypes (C-G-G, T-A-G, and C-G-T) were significantly associated with serum lipid parameters. The -1131T>C genotypes were correlated with TG, and c.553G>T and c.457G>A genotypes were associated with HDL-C levels in nondrinkers (P<0.05 for all). For drinkers, the -1131T>C genotypes were correlated with TC, TG, LDL-C, ApoB levels and the ApoA1/ApoB ratio (P<0.01 for all); c.553G>T genotypes were correlated with TC, TG, HDL-C and LDL-C levels (P<0.05-0.01); and c.457G>A genotypes were associated with TG, LDL-C, ApoA1 and ApoB levels (P<0.05-0.01).

CONCLUSIONS

The differences in some serum lipid parameters between the drinkers and nondrinkers might partly result from different interactions of the ApoA5 gene polymorphisms and alcohol consumption.

Low density lipoprotein receptor gene Ava II polymorphism and serum lipid levels in the Guangxi Bai Ku Yao and Han populations

BACKGROUND

Several common genetic polymorphisms in the low density lipoprotein receptor (LDL-R) gene have associated with modifications of serum total cholesterol (TC) and low density lipoprotein cholesterol (LDL-C) levels, but the results are not consistent in different populations. Bai Ku Yao is a special subgroup of the Yao minority in China. The present study was undertaken to detect the association of LDL-R gene Ava Ⅱ polymorphism and serum lipid levels in the Guangxi Bai Ku Yao and Han populations.

METHODS

A total of 1024 subjects of Bai Ku Yao and 792 participants of Han Chinese were randomly selected from our previous stratified randomized cluster samples. Genotyping of the LDL-R gene Ava Ⅱ polymorphism was performed by polymerase chain reaction and restriction fragment length polymorphism combined with gel electrophoresis, and then confirmed by direct sequencing.

RESULTS

The levels of serum TC, high density lipoprotein cholesterol (HDL-C), LDL-C, apolipoprotein (Apo) A1 and the ratio of ApoA1 to ApoB were lower in Bai Ku Yao than in Han (P < 0.01 for all). The frequency of A⁻ and A+ alleles was 65.5% and 34.5% in Bai Ku Yao, and 80.7% and 19.3% in Han (P < 0.001); respectively. The frequency of A⁻A⁻, A⁻A+ and A+A+ genotypes was 42.6%, 45.9% and 11.5% in Bai Ku Yao, and 64.9%, 31.6% and 3.5% in Han (P < 0.001); respectively. There was also significant difference in the genotypic frequencies between males and females in Bai Ku Yao (P <0.05), and in the genotypic and allelic frequencies between normal LDL-C (≤ 3.20 mmol/L) and high LDL-C (> 3.20 mmol/L) subgroups in Bai Ku Yao (P < 0.05 for each) and between males and females in Han (P < 0.05 for each). The levels of LDL-C in males and TC and HDL-C in females were different among the three genotypes (P < 0.05 for all) in Bai Ku Yao, whereas the levels of HDL-C in males and HDL-C and ApoA1 in females were different among the three genotypes (P < 0.05-0.001) in Han. The subjects with A+A+ genotype had higher serum LDL-C, TC, HDL-C or ApoA1 levels than the subjects with A-A+ and A⁻A⁻ genotypes. Spearman rank correlation analysis revealed that the levels of LDL-C in Bai Ku Yao and HDL-C in Han were correlated with genotypes (P < 0.05 and P < 0.01; respectively).

CONCLUSIONS

The association of LDL-R gene Ava Ⅱ polymorphism and serum lipid levels is different between the Bai Ku Yao and Han populations. The discrepancy might partly result from different LDL-R gene Ava Ⅱ polymorphism or LDL-R gene-environmental interactions.

Stimulatory effect of LPS and feedback effect of PGE2 on IL-27 production

Interleukin (IL)-27 is a new member of the IL-6/IL-12 family, composed of two subunits, the Epstein-Barr virus-induced gene 3 (EBI3) and p28 chains (p28), and produced by activated monocytes and dendritic cells. IL-27 plays an important role in the regulation of differentiation of naive T helper cells and has diverse effects on innate immune cells. However, the pro-inflammatory mechanisms of IL-27 are still not well known. In this study, we investigated the effect of lipopolysaccharide (LPS) on the production of IL-27. We found that LPS-stimulated IL-27 production was in a dose-dependent and time-dependent manner in THP-1 cells. We have also shown that IL-27 induced PGE2 production and COX-2 gene expression at the level of mRNA as well as protein. Moreover, we found feed back effect of PGE2 on the production of IL-27 in THP-1 cells. The results suggest that PGE2 significantly inhibits LPS-induced IL-27 production, without affecting basal IL-27 expression. Further experiment suggests that PGE2 and LPS regulate IL-27 through NF-κB pathway. Our findings may have wide implication for IL-27 in inflammatory diseases.

Association of methylenetetrahydrofolate reductase C677T polymorphism and serum lipid levels in the Guangxi Bai Ku Yao and Han populations

Background

The association of methylenetetrahydrofolate reductase (MTHFR) gene polymorphism and serum lipid profiles is still controversial in diverse ethnics. Bai Ku Yao is an isolated subgroup of the Yao minority in China. The aim of the present study was to eveluate the association of MTHFR C677T polymorphism and several environmental factors with serum lipid levels in the Guangxi Bai Ku Yao and Han populations.

Methods

A total of 780 subjects of Bai Ku Yao and 686 participants of Han Chinese were randomly selected from our previous stratified randomized cluster samples. Genotyping of the MTHFR C677T was performed by polymerase chain reaction and restriction fragment length polymorphism combined with gel electrophoresis, and then confirmed by direct sequencing.

Results

The levels of serum total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), apolipoprotein (Apo) AI and ApoB were lower in Bai Ku Yao than in Han (P < 0.05-0.001). The frequency of C and T alleles was 77.4% and 22.6% in Bai Ku Yao, and 60.9% and 39.1% in Han (P < 0.001); respectively. The frequency of CC, CT and TT genotypes was 58.7%, 37.3% and 4.0% in Bai Ku Yao, and 32.6%, 56.4% and 11.0% in Han (P < 0.001); respectively. The levels of TC and LDL-C in both ethnic groups were significant differences among the three genotypes (P < 0.05-0.01). The T allele carriers had higher serum TC and LDL-C levels than the T allele noncarriers. The levels of ApoB in Han were significant differences among the three genotypes (P < 0.05). The T allele carriers had higher serum ApoB levels as compared with the T allele noncarriers. The levels of TC, TG and LDL-C in Bai Ku Yao were correlated with genotypes (P < 0.05-0.001), whereas the levels of LDL-C in Han were associated with genotypes (P < 0.001). Serum lipid parameters were also correlated with sex, age, body mass index, alcohol consumption, cigarette smoking, and blood pressure in the both ethnic groups.

Conclusions

The differences in serum TC, TG, LDL-C and ApoB levels between the two ethnic groups might partly result from different genotypic and allelic frequencies of the MTHFR C677T or different MTHFR gene-enviromental interactions.

Association of the LIPG 584C > T polymorphism and serum lipid levels in the Guangxi Bai Ku Yao and Han populations

BACKGROUND

Endothelial lipase (EL) is a major determinant of high-density lipoprotein-cholesterol (HDL-C) metabolism, but the association of endothelial lipase gene (LIPG) polymorphism and serum HDL-C levels is scarce and conflicting in diverse populations. Bai Ku Yao is an isolated subgroup of the Yao minority in China. This study was designed to detect the association of LIPG 584C > T (rs2000813) polymorphism and several environmental factors with serum lipid levels in the Guangxi Bai Ku Yao and Han populations.

METHODS

A total of 645 subjects of Bai Ku Yao and 638 participants of Han Chinese were randomly selected from our previous stratified randomized cluster samples. Genotyping of the LIPG 584C > T was performed by polymerase chain reaction and restriction fragment length polymorphism combined with gel electrophoresis, and then confirmed by direct sequencing.

RESULTS

The levels of serum total cholesterol (TC), HDL-C, low-density lipoprotein cholesterol (LDL-C) and apolipoprotein (Apo) AI and ApoB were lower in Bai Ku Yao than in Han (P < 0.05 - 0.001). The frequency of C and T alleles was 73.5% and 26.5% in Bai Ku Yao, and 67.9% and 32.1% in Han (P < 0.01); respectively. The frequency of CC, CT and TT genotypes was 50.4%, 46.2% and 3.4% in Bai Ku Yao, and 41.4%, 53.1% and 5.5% in Han (P < 0.01); respectively. Serum HDL-C levels in both ethnic groups were different among the three genotypes (P < 0.05 for each). Serum TC levels in both ethnic groups were also different between the CC and CT/TT genotypes (P < 0.05 for each). The T allele carriers had higher serum HDL-C and TC levels than the T allele noncarriers. Multivariate logistic regression analysis showed that the levels of HDL-C and ApoB were correlated with genotypes in Bai Ku Yao (P < 0.05 for each), whereas the levels of TC and HDL-C were associated with genotypes in Han Chinese (P < 0.05 and P < 0.01). Serum lipid parameters were also correlated with several environmental factors in the both ethnic groups.

CONCLUSIONS

The frequency of LIPG 584T allele is lower in Bai Ku Yao than in Han Chinese. The LIPG 584T allele is associated with increased serum HDL-C, TC and ApoB levels. The differences in serum HDL-C, TC and ApoB levels between the two ethnic groups might partly result from different genotypic and allelic frequencies of LIPG 584C > T or different LIPG-enviromental interactions.

Halobacillus dabanensis sp. nov. and Halobacillus aidingensis sp. nov., isolated from salt lakes in Xinjiang, China

Two moderately halophilic spore-forming bacteria were isolated from salt lakes in the Xinjiang region of China. The two strains, designated AD-6T and D-8T, were aerobic, Gram-positive, rod-shaped and motile by means of peritrichous flagella. Strains AD-6T and D-8T grew in the presence of 0·5–20 % and 0·5–25 % (w/v) NaCl in complex medium, respectively. Their cell-wall peptidoglycan was of the l-orn–d-Asp type. The major menaquinone found in both strains was menaquinone-7 (MK-7). The fatty acid profile contained a large amount of branched fatty acids; the main fatty acids were anteiso-C15 : 0, anteiso-C17 : 0, iso-C15 : 0 and iso-C16 : 0. The DNA G+C content of strains D-8T and AD-6T was 41·4 and 42·2 mol%, respectively. Phylogenetic analysis based on 16S rRNA gene sequences revealed that strains D-8T and AD-6T were located in the genus Halobacillus. Levels of 16S rRNA gene sequence similarity between the isolated strains and the type strains of Halobacillus species were in the range 96·2–99·5 %. DNA–DNA relatedness values of 17·0–52·2 % were found between the two strains and other Halobacillus species. The DNA–DNA relatedness value between D-8T and AD-6T was 50·6 %. On the basis of phenotypic and chemotaxonomic properties, phylogenetic analysis and genomic distinctiveness, strains D-8T and AD-6T should be placed in the genus Halobacillus as two novel species, for which the names Halobacillus dabanensis sp. nov. (type strain=JCM 12772T=CGMCC 1.3704T) and Halobacillus aidingensis sp. nov. (type strain=JCM 12771T=CGMCC 1.3703T) are proposed, respectively.

Structural and functional studies of cinnamomin, a new type II ribosome-inactivating protein isolated from the seeds of the camphor tree

Cinnamomin is a new type II ribosome-inactivating protein (RIP). Its A-chain exhibits RNA N-glycosidase activity to inactivate the ribosome and thus inhibit protein synthesis, whereas the glycosylated B-chain is a lectin. The primary structure of cinnamomin, which exhibits approximately 55% identity with those of ricin and abrin, was deduced from the nucleotide sequences of cDNAs of cinnamomin A- and B-chains. It is composed of a total of 549 amino-acid residues: 271 residues in the A-chain, a 14-residue linker and 264 residues in the B-chain. To explore its biological function, the cinnamomin A-chain was expressed in Escherichia coli with a yield of 100 mg per L of culture, and purified through two-step column chromatography. After renaturation, the recovery of the enzyme activity of the expressed A-chain was 80% of that of native A-chain. Based on the modeling of the three-dimensional structure of the A-chain, the functional roles of five amino acids and the only cysteine residues were investigated by site-directed mutagenesis or chemical modification. The conserved single mutation of the five amino-acid residues led to 8-50-fold losses of enzymatic activity, suggesting that these residues were crucial for maintaining the RNA N-glycosidase activity of the A-chain. Most interestingly, the strong electric charge introduced at the position of the single cysteine in A-chain seemed to play a role in enzyme/substrate binding.

[Two new glycosides from Erigeron breviscapus (Vant.) Hand.-Mazz]

OBJECTIVE

To study the chemical constituents from the upground part of Erigeron breviscapus.

METHOD

The compounds were separated and purified by column chromatography with silica gel, and identified by IR, MS, NMR and 2D-NMR.

RESULT

Two new compounds were isolated and identified as 5,4'-dihydroxy flavonod-7-O-beta-D-pyranglycuronate buthyl ester(VI) and 3,5-dimethoxy benzene carbonic acid-4-O-beta-D-pyranglucose(VII).

CONCLUSION

Compounds VI and VII were new compounds.

[Studies on chemical constituents of Bletilla striata (Thunb) Reichb. f]

OBJECTIVE

To study the chemical constituents of Bletilla striata.

METHOD

The constituents were separated and purified by column chromatography with silica gel, and identified by NMR, MS and physical data.

RESULT

Three compounds were isolated and identified as hexacosanoic alcohol 3-(4-hydroxy-3-methoxybenzol)-trans-acryliceylenate(1), physcion(2) and cyclobalanol(3).

CONCLUSION

Compound 1 was a new compound and compound 3 was isolated from this plant for the first time.

Addressing cultural orientations in fear appeals: promoting AIDS-protective behaviors among Mexican immigrant and African American adolescents and American and Taiwanese college students

Fear appeals threatening the individual have been shown to be powerful persuasive devices in the cultures where they have been studied. However, most fear appeal research has been conducted with members of individualist cultures. Individualist cultures place self-needs above group concerns, while collectivist cultures place group needs above self-concerns. Little is known about the effectiveness of fear appeals (or other persuasive strategies) in collectivist cultures. Two studies assessed the effectiveness of AIDS-prevention fear appeals threatening the self versus fear appeals threatening the group (i.e., family) on members of individualist and collectivist cultures. The first study focuses on African American and Mexican immigrant junior high school youth. The second study focuses on U.S. and Taiwanese college undergraduates. The results indicated that fear appeals should address cultural orientation (i.e., individualist versus collectivist orientation) to achieve maximum effectiveness. The results also indicate that one cannot assume cultural orientation based on ethnicity.

The structure dependent electrochemical-response of novel 1-(4-mercaptobutyl)-4-(2-ferrocenylvinyl)pyridinium bromide SAMs on an au electrode

The 1-(4-mercaptobutyl)-4-(2-ferrocenylvinyl)pyridinium bromide (1-HS(CH2)(4)-4-[(E)-FcCH=CH]C5H4N)+Br- and its hydrogenated product [1-HS(CH2)(4)-4-(-FcCH2CH2)C5H4N]+Br- were synthesized and assembled on an Au electrode to form self-assembled monolayers which showed a structure-dependent electrochemical-response in phosphate buffer aqueous solutions (pH = 7).

Exploration of RNA 3' terminal locations in rat ribosome

The locations of the 3' ends of RNAs in rat ribosome were studied by a fluorescence-labeling method combined with high hydrostatic pressure and agarose electrophoresis. Under physiological conditions, only the 3' ends of 28 S and 5.8 S RNA in 80 S ribosome could be labeled with a high sensitive fluorescent probe - fluorescein 5-thiosemicarbazide (FTSC), indicating that the 3' termini of 28 S and 5.8 S RNA were located on or near the surface of 80 S ribosome. The 3' terminus of 5 S RNA could be attacked by FTSC only in the case of the dissociation of the 80 S ribosome into two subunits induced by high salt concentration (1 M KCl) or at high hydrostatic pressure, showing that the 3' end of 5 S RNA was located on the interface of two subunits. However, no fluorescence-labeled 18 S RNA could be detected under all the conditions studied, suggesting that the 3' end of 18 S RNA was either located deeply inside ribosome or on the surface but protected by proteins. It was interesting to note that modifications of the 3' ends of ribosomal RNAs including oxidation with NaIO4, reduction with KBH4 and labeling with fluorescent probe did not destroy the translation activity of ribosome, indicating that the 3' ends of RNAs were not involved in the translation activity of ribosome.

Eukaryotic elongation factor 2 can bind to the synthetic oligoribonucleotide that mimics sarcin/ricin domain of rat 28S ribosomal RNA

Eukaryotic elongation factor 2 (eEF2) catalyzes the translocation of peptidyl-tRNA from the A site to P site by binding to the ribosome. In this work, the complex formation of rat liver eEF2 with a synthetic oligoribonucleotide (SRD RNA) that mimics sarcin/ricin domain of rat 28S ribosomal RNA is invested in vitro. Purified eEF2 can specifically bind SRD RNA to form a stable complex. tRNA competes with SRD RNA in binding to eEF2 in a less extent. Pretreatment of eEF2 with GDP or ADP-ribosylation of eEF2 by diphtheria toxin can obviously reduce the ability of eEF2 to form the complex with the synthetic oligoribonucleotide. These results indicate that eEF2 is likely to bind directly to the sarcin/ricin domain of 28S ribosomal RNA in the process of protein synthesis.

Non-specific deadenylation and deguanylation of naked RNA catalyzed by ricin under acidic condition

Ricin A-chain catalyzes the hydrolysis of the N-glycosidic bond of a conserved adenosine residue at position 4324 in the sarcin/ricin domain of 28S RNA of rat ribosome. The GAGA tetraloop closed by C-G pairs is required for recognition of the cleavage site on 28S ribosomal RNA by ricin A-chain. In this study, ricin A-chain (reduced ricin) exhibits specific depurination on a synthetic oligoribonucleotide (named SRD RNA) mimic of the sarcin/ricin domain of rat 28S ribosomal RNA under neutral and weak acidic conditions. Furthermore, the activity of intact ricin is also similar to that of ricin A-chain. However, under more acidic conditions, both enzymes lose their site specificity. The alteration in specificity of depurination is not dependent on the GAGA tetraloop of SRD RNA. A higher concentration of KCl inhibits the non-specific N-glycosidase activity much more than the specific activity of ricin A-chain. In addition, characterization of depurination sites by RNA sequencing reveals that under acidic conditions ricin A-chain can release not only adenines, but also guanines from SRD RNA or 5S ribosomal RNA. This is the first report of the non-specific deadenylation and deguanylation activity of ricin A-chain to the naked RNA under acidic conditions.

[Biliary tract reconstruction after cystectomy of congenital choledochal cyst]

OBJECTIVE

To evaluate the operative methods of biliary tract reconstruction after cystectomy of congenital choledochal cyst(CCC).

METHODS

One hundred and six cases with CCC underwent cystectomy and biliary tract reconstruction in our hospital from July 1984 to December 1999 were followed up. Among them, there were three kinds of procedures in biliary tract reconstruction: with single Roux-Y hepaticojejunostomy in 48 cases, with intussusceptive valve to the line of Roux-Y hepaticojejunostomy in 37 cases, with rectangular valve to the line of Roux-Y hepaticojejunostomy in 21 cases.

RESULTS

Fifty nine cases were followed up for 4.68 years in average. There were 3 cases with ascending cholangitis after single Roux-Y hepaticojejunostomy. And the symptom disappeared in 2 cases underwent reoperation with an intussueceptive valve plasty to the line of Roux-Y hepaticojejunostomy. No patients suffered from ascending cholangitis in the precautionary valve plasty group.

CONCLUSION

It suggests that the postoperative ascending cholangitis can be prevented effectively if standard cystectomy and prophylactic intussusceptive valve added to the line of Roux-Y hepaticojejunostomy are carried out. The procedure should be performed as soon as possible providing the child is tolerable.

[Structural elucidation of a new tetrahydroxystilbene of Radix Polygoni Multiflori Preparata and study on its cardiovascular activity]

AIM

To investigate the cardiovascular active constituents of Radix Polygoni multiflori Preparata.

METHODS

Compounds were isolated from the water soluble extract with column chromatography of Sephadex, ODS and HPLC. The compounds were identified on the basis of spectral analysis (IR, EI-MS, FAB-MS, 1HNMR, 13CNMR, 2D-NMR) and phytochemical properties. Its inhibitory effect on the proliferation of bovine vascular smooth muscle cells were bioassayed in vitro.

RESULTS

One compound was isolated and identified as: 2,3,5,4'-tetrahydroxystilbene-2-O-(6"-O-alpha-D- glucopyranosyl)-beta-D-glucopyranoside.

CONCLUSION

Compound I is a new compound with cardiovascular activity.

Use of prawn blood agar hemolysis to screen for bacteria pathogenic to cultured tiger prawns Penaeus monodon

A newly developed prawn blood agar consisting of 1 ml of tiger prawn hemolymph in medium containing 200 ppm Rose Bengal was used to determine the hemolytic activity of 35 isolates of bacteria obtained from cultured tiger prawns Penaeus monodon and their rearing water. For comparison, the hemolytic activity of these isolates was also determined in sheep blood agar. Nine isolates (25.7% of total) showed different hemolytic reactions on prawn blood agar and sheep blood agar. From the 35 isolates, 8 with various hemolytic characteristics were selected and the relationship between the type of hemolytic activity and pathogenicity was determined and compared. Four isolates that showed hemolytic activity in prawn blood agar caused high mortality to cultured tiger prawns. By contrast, a significantly lower mortality rate was observed for tiger prawns injected with 4 isolates that did not exhibit hemolytic activity on prawn blood agar. Results further showed that mortality did not correlate with hemolytic activity determined using sheep blood agar. Prawn blood agar containing P. monodon hemocytes was faster and more accurate for determining prawn hemolytic activity of bacterial isolates.