α-Diazoesters were discovered to be good electrophiles in a catalytic asymmetric α-functionalization of ketones for the first time. This reaction also provided a direct and efficient method for C-N bond formation with excellent yields (up to 98%) and enantioselectivities (up to 99% ee) under mild conditions. The application of the electrophilicity of α-diazoesters opens up a novel way to access the diversity of diazo chemistry.

The present study was designed to examine whether rabbits fed a diet containing high fat and sucrose could develop obesity and insulin resistance (IR), the major pathophysiological features of metabolic syndrome. Male Japanese white rabbits were fed either a normal chow diet (control) or high fat and sucrose diet (HFSD) for 36 weeks. Plasma levels of triglycerides (TG), total cholesterol (TC), glucose and insulin were measured. To evaluate glucose metabolism, we performed an intravenous glucose tolerance test. In addition, we compared adipose tissue accumulation in HFSD-fed rabbits with that in normal rabbits. HFSD constantly and significantly led to an increase in body weight of HFSD-fed rabbits, caused by significantly higher visceral adipose tissue accumulation. Although there were no differences in plasma TG, TC, glucose, insulin levels and blood pressure between the two groups, HFSD-fed rabbits showed impaired glucose clearance associated with higher levels of insulin secretion compared to control rabbits. Our results showed that HFSD induced IR and increased adipose accumulation in rabbits, suggesting that HFSD-fed rabbits may become a model for research on human IR and obesity.

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Background: Dermatophytes are fungi that cause superficial infections of the skin, hair, and nails. They are the most common agents of fungal infections worldwide. Dermatophytic fungi constitute three genera, Trichophyton, Epidermophyton, and Microsporum, and the evolutionary relationships between these genera are epidemiologically important. Mitochondria are considered to be of monophyletic origin and mitochondrial sequences offer many advantages for phylogenetic studies. However, only one complete dermatophyte mitochondrial genome (E. floccosum) has previously been determined.

Abstract:Objective: To investigate the effects of T-2 toxin on expressions of Fas, p53, Bcl-xL, Bcl-2, Bax and caspase-3 on human chondrocytes. Methods: Human chondrocytes were treated with T-2 toxin (1~20 ng/ml) for 5 d. Fas, p53 and other apoptosis-related proteins such as Bax, Bcl-2, Bcl-xL, caspase-3 were determined by Western blot analysis and their mRNA expressions were determined by reverse transcriptase-polymerase chain reaction (RT-PCR). Results: Increases in Fas, p53 and the pro-apoptotic factor Bax protein and mRNA expressions and a decrease of the anti-apoptotic factor Bcl-xL were observed in a dose-dependent manner after exposures to 1~20 ng/ml T-2 toxin, while the expression of the anti-apoptotic factor Bcl-2 was unchanged. Meanwhile, T-2 toxin could also up-regulate the expressions of both pro-caspase-3 and caspase-3 in a dose-dependent manner. Conclusion: These data suggest a possible underlying molecular mechanism for T-2 toxin to induce the apoptosis signaling pathway in human chondrocytes by regulation of apoptosis-related proteins.

The first catalytic enantioselective Roskamp reaction of alpha-alkyl-alpha-diazoesters with aromatic aldehydes was realized using a simple chiral N,N'-dioxide-scandium(III) complex. Remarkably, with 0.05 mol % catalyst, the reaction was performed well over a series of substrates, giving the desired products chemoselectively in excellent yields (up to 99%) and enantioselectivities (up to 98% ee) under mild conditions. This protocol provides a promising method for the synthesis of chiral alpha-alkyl-beta-keto esters and 1,3-diols.

Simian parvovirus (SPV) is a member of the genus Erythrovirus and is closely related to the human parvovirus B19. Natural and experimental infection of monkeys with SPV resembles B19 infection of human.We report a detailed characterization of the viral RNAs and proteins generated following transfection of cloned SPV into COS cells and SPV infection of the human erythroid progenitor line UT-7/Epo-S1. SPV and B19 are 50% identical at the nucleotide level, and although their basic transcription and protein expression profiles were generally similar, there were also significant differences. SPV pre-mRNAs contain three introns, compared to two found for B19: an additional intron was found within the capsid-coding region. RNAs in which this intron was spliced were abundant and encoded the SPV 14-kDa protein (analogous to the B19 11-kDa protein), which initiated at an AUG in the exon preceding the third intron. Unlike B19, SPV RNAs were also spliced between the donor of the first intron and the acceptor of the second intron. The third intron was additionally spliced from a portion of these molecules; these mRNAs encoded the 14-kDa protein. A portion was not spliced further and encoded VP2. Like B19, SPV has a polyadenylation signal [AAUAAA (pA)p] in the middle of the genome, which directed efficient polyadenylation of both spliced and unspliced mRNAs (encoding a putative 10-kDa protein, analogous to the B19 7.5-kDa protein, and SPV NS1, respectively). The 14-kDa protein was localized to both in the nucleus and cytoplasm.Autonomous parvoviruses with tropism for erythroid cells are classified as erythroviruses. This group includes the human erythroviruses, represented by human B19 virus (B19) (27) and its variants V9 (26) and A6 (13), and the nonhuman primate erythroviruses simian parvovirus (SPV) (14), pig-tailed macaque parvovirus (8), rhesus parvovirus (8) and, possibly, the chipmunk parvovirus (32). SPV was initially isolated from cynomolgus monkeys (14) and is remarkably similar to the human B19 parvovirus, exhibiting a predilection for host bone marrow in vitro and the ability to cause serious anemia in some infected animals (15, 16).SPV has a single-stranded genome of approximately 5,600 nucleotides (nt) (3), and its nucleotide sequence, except for its inverted terminal repeats, has been determined. Comparison of the SPV sequence with that of other parvoviruses shows 50% overall homology with parvovirus B19 (27). At the protein level, there is approximately 70% homology with B19 capsid proteins and 50% homology with B19 NS proteins (3). SPV has been cultured in vivo in both human and monkey bone marrow cells and in the human erythroid progenitor cell lines UT-7/ Epo-S1 and KU812Ep6 (4), albeit with low infectivity. Similar to the organization of B19, SPV has two large open reading frames (ORFs) in either half of the genome. The left ORF encodes the nonstructural NS1 protein, and the right ORF encodes the two capsid proteins VP1 and VP2 (3, 31). Expression of the VP2 ORF of SPV results in the generation of virus-li...

Small RNAs (sRNAs) are involved in the post-transcriptional regulation of metabolic pathways and in responses to stress and virulence. We analyzed the expression levels of five sRNAs of Staphylococcus aureus during human colonization or infection. Total RNA was isolated from nasal carriers, abscesses and cystic fibrosis patients (20 subjects per condition). The expression levels of the sRNAs were measured in the clinical samples and compared with those of the corresponding strains grown in vitro. Five sRNAs were encoded and expressed in all clinical strains in vitro. In vivo, the global expression of the five sRNAs was extremely variable in the abscessed patients, more homogeneous in the cystic fibrosis patients, and highly uniform in the nasal carrier samples. The expression levels of the sRNAs in vivo resembled those obtained at exponential phase or late exponential phase of growth in vitro, for three and one sRNA respectively; while for one sRNA, the expression was always higher in vivo as compared to in vitro growth. The in vitro conditions do not uniformly mimic the in vivo conditions for sRNA expression. Nasal colonization is associated with a unique expression pattern of sRNA that might reflect the commensalism of S. aureus in this niche.