Selection pressure on the hemagglutinin gene of influenza A (H1N1) virus: adaptation to human and swine hosts in Asia

Influenza A (H1N1) virus is an important pathogen that can be transmitted in the enzootic cycle involved in influenza epidemics. In this study, we analyzed natural selection on the 260 sequences of subtype 1 hemagglutinin (HA1) gene of H1N1 viruses isolated from humans and swine in Asia. Nonsynonymous and synonymous substitution rates (dN, dS) were determined for each amino acid site in the HA1 coding region. Four and two positively selected sites were identified in human and swine viruses, respectively. These sites might be involved in the change of antigenic epitopes to evade the host immune system. The results indicate that more diversifying and less purifying selection controls HA1 of human viruses compared with the swine viruses. Furthermore, thirteen sites evolving differently in human and swine viruses were identified in the HA1. These sites may play a role in the cross-species transmission. The analysis of adaptive evolution of the HA1 can provide valuable information for accelerating vaccine and drug development for prevention and treatment of influenza A (H1N1) in Asia.

KEYWORDS

Influenza A virus; H1N1; hemagglutinin; positive selection; antigenic epitope.

Low-dose MTX combined with low-dose methylprednisolone as a first-line therapy for the treatment of acute GVHD: safety and feasibility

To study the efficacy and safety of a low dose of MTX combined with a low dose of methylprednisolone (MP) as a first-line therapy in the treatment of acute GVHD (aGVHD) after allogeneic hematopoietic SCT, 32 patients received i.v. MTX at a dose of 10 mg or oral MTX at a dose of 15 mg every 3-7 days (repeated at day 3 after the first dose and then at a weekly interval) combined with a low dose of MP (0.5 mg/kg/day) until a complete or partial response was achieved, or until treatment failure or intolerable side effects occurred. The overall treatment response rate was 81% (26/32 patients) and the response rate at day 28 was 75% (24/32 patients). The response rate for GVHD involving various organs was 88% (23/26) in the skin, 75% (3/4) in the liver and 81% (9/11) in the gut. Grade 3 toxicities occurred in only three patients presenting cytopenias. The estimated survival at 2 years was 77%. From this analysis, MTX in combination with a low dose of MP appears to be a well-tolerated, effective and inexpensive regime when used as a first-line treatment for aGVHD.

Novel 12-bp deletion in the coding region of the bovine NPM1 gene affects growth traits

The nucleophosmin 1 gene (NPM1) encodes a multifunctional nucleolar phosphoprotein that plays a crucial role in the control of various aspects of cell growth and homeostasis. In this study, the coding region of the NPM1 gene was screened in 1035 individuals of 4 Chinese cattle breeds by DNA sequencing and polyacrylamide gel electrophoresis. A novel 12-bp deletion mutation was identified in the coding region of the NPM1 gene. The PCR products of primer NPM1-P2 exhibited 3 genotypes and 2 alleles: 178 bp (denoted as W) and 166 bp (denoted as D). Genotype DD and allele D were predominant in the studied populations. Association analysis with growth traits in the Nanyang breed (N = 265) showed that the animals with genotype DD had significantly greater birth weight, body weight, body length, and heart girth than those with genotype WD (P < 0.01 or P < 0.05) at birth and after 6 months and 12 months, but not at 18 and 24 months of age. Results of this study suggest that the NPM1 gene is a candidate gene for growth traits in cattle.

Evidence for significantly enhancing reduction of Azo dyes in Escherichia coli by expressed cytoplasmic Azoreductase (AzoA) of Enterococcus faecalis

Although cytoplasmic azoreductases have been purified and characterized from various bacteria, little evidence demonstrating that these azoreductases are directly involved in azo dye reduction in vivo is known. In order to evaluate the contribution of the enzyme to azo dye reduction in vivo, experiments were conducted to determine the effect of a recombinant cytoplasmic azoreductase (AzoA) from Enterococcus faecalis expressed in Escherichia coli on the rate of metabolism of Methyl Red, Ponceau BS and Orange II. The intact cells that contained IPTG induced AzoA had a higher rate of dye reduction with increases of 2 (Methyl Red), 4 (Ponceau BS) and 2.6 (Orange II)-fold compared to noninduced cells, respectively. Metabolites of Methyl Red isolated from induced cultures were identified as N,N-dimethyl-p-phenylenediamine and 2-aminobenzoic acid through liquid chromatography electrospray ionization tandem mass spectrometry (LC/ESI-MS/MS) analyses. In conclusion, our data demonstrate that AzoA from Ent. faecalis is capable of increasing the reduction of azo dyes in intact E. coli cells and that cytoplasmic azoreductase is involved in bacterial dye degradation in vivo.

Maternal overnutrition impacts offspring adiposity and brain appetite markers-modulation by postweaning diet

Maternal obesity has long-term consequences for the development of hypothalamic neurones involved in energy homeostasis and the metabolic profile in offspring. In the present study, we compared the effects of maternal obesity induced by longstanding high-fat diet (HFD) with milder postnatal overfeeding during suckling induced by litter size reduction. Female Sprague-Dawley rats consumed chow (C) or HFD. On postnatal day 1, litters from chow dams were adjusted to three per dam (small litter, CS) versus 12 control (normal litter, CN). Litters from HFD dams were adjusted to 12 per dam and fed HFD after weaning to induce obesity (HN). Thus, two degrees of maternal overnutrition were produced (CS and HN). To test whether postweaning diet can amplify the effects of maternal obesity, male offspring weaned onto chow or HFD were followed to 21 weeks. Maternal postnatal overnutrition (CS) and HFD-induced maternal obesity (HN) increased body weight and fat mass in offspring compared to those from control dams (CN). Significant glucose intolerance was induced by both degrees of maternal overnutrition, but only in offspring consuming HFD. HFD-induced maternal obesity (HN) was linked to increased offspring leptin, insulin, lipids, insulin resistance and hyperphagia, and was exaggerated by postweaning HFD. No effect of maternal postnatal overnutrition (CS) was seen on these parameters. Hypothalamic signal transducer and activator of transcription-3 and suppressor of cytokine signalling-3 mRNA were significantly elevated by maternal HFD (HN) in the HFD-fed offspring. The data obtained suggest that even mild maternal overnutrition (CS) led to increased adiposity, glucose intolerance and altered brain appetite regulators in offspring. A greater impact of HFD-induced maternal obesity was evident. Marked additive effects were observed when animals consumed a HFD postweaning.

8q24 allelic imbalance and MYC gene copy number in primary prostate cancer

Four independent regions within 8q24 near the MYC gene are associated with risk for prostate cancer. Here we investigated allelic imbalance at 8q24 risk variants and MYC gene DNA copy number (CN) in 27 primary prostate cancers. Heterozygotes were observed in 24 of 27 patients at one or more 8q24 markers and 27% of the loci exhibited AI in tumor DNA. 8q24 risk alleles were preferentially favored in the tumors. Increased MYC gene CN was observed in 33% of tumors, and the co-existence of increased MYC gene CN with AI at risk loci was observed in 86% (P<0.004 exact binomial test) of the informative tumors. No AI was observed in tumors which did not reveal increased MYC gene CN. Higher Gleason score was associated with tumors exhibiting AI (P=0.04), and also with increased MYC gene CN (P=0.02). Our results suggest that AI at 8q24 and increased MYC gene CN may both be related to high Gleason score in prostate cancer. Our findings also suggest that these two somatic alterations may be due to the same preferential chromosomal duplication event during prostate tumorigenesis.

The polymorphisms of bovine melanocortin-3 receptor pseudogene

Mammalian melanocortin-3 receptor (MC3R) plays an important role in the central control of energy homeostasis, and several functional polymorphisms of mc3r have been detected. Interestingly, the bovine mc3r was a pseudogene, and its polymorphisms and function remain to be investigated. Single-strand conformation polymorphism (SSCP) showed 5, 2 and 3 genotypes in fragment F1, F2 and F3 of mc3r in seven cattle breeds, respectively. All genotypes revealed novel sequences. Three SNPs 657G>T, 756C>T, 822T>C were detected in fragment F1, five SNPs 1091T>C, 1133T>C, 1144C>T, 1259T>C and 1319G>A were detected in fragment F2, and two SNPs 1687G>A, 1860C>T were detected in F3. The SNPs in fragment F1 and F2 were located at exon 2. The five SNPs in fragment F2 demonstrated a tight linkage disequilibrium status. Variation detected here might have an impact on the function of bovine mc3r pseudogene.

Bortezomib plus intermediate-dose dexamethasone and thalidomide in elderly untreated patients with multiple myeloma: a Chinese experience

Bortezomib has proven to be active in patients with multiple myeloma (MM), including elderly patients. The aim of this study was to evaluate the efficacy and toxicity of bortezomib in combination with intermediate-dose dexamethasone (Dex) and thalidomide in untreated MM patients aged > or =65 years in a Chinese single center. In this study, 18 patients were treated with bortezomib at 1.3 mg/m(2) IV on Days 1, 4, 8, and 11 and Dex at 20 mg/day IV on Days 1-4 and 8-11 simultaneously. Thalidomide at dose of 100 mg/day was given everyday. The mean number of cycles of bortezomib treatment was 2.06. Three patients (17%) achieved a complete response (CR), four (22%) a very good partial response (VGPR), and nine (50%) a PR, resulting in an overall response rate of 89%. The median time to response was 22 days (range 14-50 days). The duration of response was significantly longer in patients achieving a CR/VGPR with respect to those achieving only a PR (8.5 vs. 4.2 months, P = 0.03). Grade 3-4 toxicities occurring in patients comprised weakness, thrombocytopenia, diarrhea, infection, and neuropathy. Only one patient suffered from deep vein thrombosis. This preliminary experience in Chinese patients indicated that bortezomib-Dex-thalidomide is highly effective in elderly untreated patients with MM, even in patients with poor prognostic features.

S-novel SNP of alpha-lactalbumin gene in chinese dairy goats

The alpha-lactalbumin (alpha-LA) plays a key role in lactose synthesis in mammary glands of domestic animals. Mutations in the alpha-LA gene are associated with the milk traits in dairy cattle. In our study, a novel SNP: NO_X06366:g.875 C > T was detected in 708 dairy goat individuals--268 of the Xinong Saanen breed and 440 of Guanzhong breed, which revealed a synonymous mutation in the exon 1 of alpha-LA gene. The Polymerase Chain Reaction-Single Strand Conformation Polymorphism (PCR-SSCP) and sequencing techniques showed that there were three genotypes: CC, CT and TT. Moreover, the chi2-test showed that the genotype frequencies of the two breeds were in good agreement with the Hardy-Weinberg equilibrium (P > 0.05). The relationship of the polymorphism of dairy goat alpha-LA gene with the milk trait and the body size trait was revealed. Individuals with the CC genotype were significantly smaller at chest circumference than those with CT (P < 0.05) in both breeds. But the milk trait and other body size traits of the two dairy goat breeds had no significant association with genotypes studied.

Establishment of an H6N2 influenza virus lineage in domestic ducks in southern China

Multiple reassortment events between different subtypes of endemic avian influenza viruses have increased the genomic diversity of influenza viruses circulating in poultry in southern China. Gene exchange from the natural gene pool to poultry has contributed to this increase in genetic diversity. However, the role of domestic ducks as an interface between the natural gene pool and terrestrial poultry in the influenza virus ecosystem has not been fully characterized. Here we phylogenetically and antigenically analyzed 170 H6 viruses isolated from domestic ducks from 2000 to 2005 in southern China, which contains the largest population of domestic ducks in the world. Three distinct hemagglutinin lineages were identified. Group I contained the majority of isolates with a single internal gene complex and was endemic in domestic ducks in Guangdong from the late 1990s onward. Group II was derived from reassortment events in which the surface genes of group I viruses were replaced with novel H6 and N2 genes. Group III represented H6 viruses that undergo frequent reassortment with multiple virus subtypes from the natural gene pool. Surprisingly, H6 viruses endemic in domestic ducks and terrestrial poultry seldom reassort, but gene exchanges between viruses from domestic ducks and migratory ducks occurred throughout the surveillance period. These findings suggest that domestic ducks in southern China mediate the interaction of viruses between different gene pools and facilitate the generation of novel influenza virus variants circulating in poultry.

Construction of an Acid-Tolerant Rhizobium leguminosarum Biovar Trifolii Strain with Enhanced Capacity for Nitrogen Fixation

Strain ANU1173 is an acid-tolerant Rhizobium leguminosarum biovar trifolii strain that is able to nodulate subterranean clover plants growing in agar culture at pH 4.4 At pH 6.5, its symbiotic effectiveness in association with Trifolium subterraneum cv. Mt. Barker was 80% relative to that of strain ANU794, a Sm derivative of the commercial inoculant R. leguminosarum bv. trifolii TA1. Strain ANU1173 contained four indigenous megaplasmids, the smallest of these being the symbiotic (Sym) plasmid. The critical pH requirement for growth of strain ANU1173 in laboratory media was shown not to be associated with this plasmid. When the Sym plasmid of strain ANU1173(pSym-1173) was mobilized into a Nod strain of R. leguminosarum bv. viciae, the plasmid conferred to the transconjugant a level of symbiotic effectiveness in association with T. subterraneum that was similar to that observed with ANU1173. The symbiotic effectiveness of strain ANU1173 was improved by first curing pSym-1173 (generating strain ANU1184) and replacing it with another R. leguminosarum bv. trifolii Sym plasmid, pBR1AN. Subterranean clover plants inoculated with strain ANU1184 (pBR1AN) exhibited a 35 or 53% increase in acetylene reduction activity and a 20 or 17% increase in dry weight when grown at pH 6.5 and pH 4.4, respectively, compared with plants inoculated with strain ANU1173 and grown under the same pH conditions. It was further shown that pBR1AN was stably maintained in strain ANU1184 under free-living and symbiotic conditions. These results indicate that it is possible to construct an acid-tolerant strain of R. leguminosarum bv. trifolii with an enhanced capacity for nitrogen fixation.

Evidence for competing magnetic and superconducting phases in superconducting Eu 1-x Sr x Fe 2-y Co y As 2 single crystals

In single crystals of Eu(1-x)Sr(x)Fe(2-y)Co(y)As(2), Co doping suppresses spin-density wave (SDW) ordering and induces a superconducting transition. A resistivity reentrance due to the antiferromagnetic ordering of Eu(2+) spins is observed, indicating the competition between antiferromagnetism (AFM) and superconductivity (SC). It is striking that the resistivity reentrance can be completely suppressed by a small magnetic field due to a field-induced metamagnetic transition from AFM to ferromagnetism (FM). The resistivity reentrance can also be suppressed by the substitution of Eu(2+) ions with nonmagnetic Ba(2+)/Sr(2+) to completely destroy the AFM ordering. These results indicate that the AFM order appears destructive to SC, while FM can coexist with the superconductivity. Further we find that magnon excitation exists in AFM ordering and can be suppressed by an applied field. Coexistence of SC from the FeAs layer and the inner field produced by the ferromagnetic Eu(2+) layer suggest a possible p-wave component in the superconducting order parameter.

Effect of intermittent treatment with human Parathyroid Hormone 1-34 in SAMP6 senescence-accelerated mice

We examined trabecular and cortical bone in the senescence-accelerated mouse prone 6 (SAMP6) murine model of senile osteoporosis after treatment with human PTH 1-34. Sixteen-week-old female SAMP6 mice were assigned to control and PTH groups. PTH (20 microg/kg) was administered sc 3 times a week for 12 weeks. The control mouse strain, senescence-accelerated mouse resistant 1 (SAMR1), was used for comparison. The femoral metaphysis and diaphysis were used to measure bone mineral density (BMD), analyze the trabecular and the cortical structure by micro-computed tomography, and for conducting the bone strength test. PTH significantly attenuated the loss of BMD, improved the trabecular bone microstructure, and increased the bone strength in the femoral metaphysis. We did not find any differences in the bone strength of the femoral diaphysis after PTH treatment, although the cortical bone volume and cortical thickness were improved. Although the cortical thickness increased, the cortical bone density decreased, likely because of the increase of cortical porosity in the distal metaphysis after administration of PTH.