Elevation of Vδ1 T cells in peripheral blood and livers of patients with primary biliary cholangitis

Primary biliary cholangitis (PBC), hitherto called primary biliary cirrhosis, is a cholestatic liver disease of unclear aetiology with autoimmune features. Accumulating evidence revealed that γδ T cells were involved in the development of autoimmune diseases. As one of γδ T cells subsets, however, the role of Vδ1 T cells in the immunopathogenesis of PBC is poorly understood. We analysed peripheral blood Vδ1 T cells in PBC patients in active stage (ASP, n = 18), adequate responders (AR, n = 10) and inadequate responders (IAR, n = 4) to ursodeoxycholic acid (UDCA) and an age-matched healthy control group (n = 16) by flow cytometric analysis. The ASP group exhibited a significantly higher proportion and absolute number of Vδ1 T cells, which were also observed in immunofluorescence staining of liver biopsy specimens of PBC patients. Moreover, these Vδ1 T cells expressed a series of activation markers and intracellular cytokines, which may contribute to the immunopathogenesis of PBC. Our study will help to clarify the role of Vδ1 T cells in the development of PBC.

Taxonomic evaluation of species in the Streptomyces hirsutus clade using multi-locus sequence analysis and proposals to reclassify several species in this clade

Previous phylogenetic analysis of species of the genus Streptomyces based on 16S rRNA gene sequences resulted in a statistically well-supported clade (100 % bootstrap value) containing eight species that exhibited very similar gross morphology in producing open looped (Retinaculum-Apertum) to spiral (Spira) chains of spiny- to hairysurfaced, dark green spores on their aerial mycelium. The type strains of the species in this clade, specifically Streptomyces bambergiensis, Streptomyces cyanoalbus, Streptomyces emeiensis, Streptomyces hirsutus, Streptomyces prasinopilosus and Streptomyces prasinus, were subjected to multi-locus sequence analysis (MLSA) utilizing partial sequences of the housekeeping genes atpD, gyrB, recA, rpoB and trpB to clarify their taxonomic status. The type strains of several recently described species with similar gross morphology, including Streptomyces chlorus, Streptomyces herbaceus, Streptomyces incanus, Streptomyces pratens and Streptomyces viridis, were also studied along with six unidentified green-spored Streptomyces strains from the ARS Culture Collection. The MLSAs suggest that three of the species under study (S. bambergiensis, S. cyanoalbus and S. emeiensis) represent synonyms of other previously described species (S. prasinus, S. hirsutus and S. prasinopilosus, respectively). These relationships were confirmed through determination of in silico DNA-DNA hybridization estimates based on draft genome sequences. The five recently described species appear to be phylogenetically distinct but the unidentified strains from the ARS Culture Collection could be identified as representatives of S. hirsutus, S. prasinopilosus or S. prasinus.

Prevalence of hepatitis A viral RNA and antibodies among Chinese blood donors

Like other developing countries, China was reported to have a relatively high seroprevalence of anti-hepatitis A antibodies (anti-HAV). However, no studies have evaluated the prevalence of anti-HAV and HAV RNA among voluntary blood donors with or without elevated serum alanine transaminase (ALT) levels. Anti-HAV antibodies were detected using an enzyme-linked immunosorbent assay, and reverse transcription quantitative polymerase chain reaction was carried out for detection of HAV RNA. In the current study, we analyzed a total of 450 serum samples with elevated ALT levels (≥40 U/L) and 278 serum samples with non-elevated ALT levels. Seroprevalence rates of anti-HAV were 51.6% in donors with elevated ALT and 41.4% in donors with non-elevated ALT; however, none of the samples was positive for HAV RNA. The results of our study showed lower seroprevalence rates of anti-HAV in blood donors (irrespective of ALT levels) than those in published data on Chinese populations. Although donors with elevated ALT had statistically higher prevalence rates of anti- HAV than did those with non-elevated ALT, none of the serum samples had detectable levels of the active virus. In conclusion, our results demonstrate that the transmission of hepatitis A by blood transfusion will occur rarely.

Mid-infrared Photoconductive Response in AlGaN/GaN Step Quantum Wells

AlGaN/GaN quantum structure is an excellent candidate for high speed infrared detectors based on intersubband transitions. However, fabrication of AlGaN/GaN quantum well infrared detectors suffers from polarization-induced internal electric field, which greatly limits the carrier vertical transport. In this article, a step quantum well is proposed to attempt solving this problem, in which a novel spacer barrier layer is used to balance the internal electric field. As a result, a nearly flat band potential profile is obtained in the step barrier layers of the AlGaN/GaN step quantum wells and a bound-to-quasi-continuum (B-to-QC) type intersubband prototype device with detectable photocurrent at atmosphere window (3-5 μm) is achieved in such nitride semiconductors.

Regulation of the Heme Oxygenase-1/carbon monoxide system by hydrogen sulfide in murine coxsackievirus B3-induced myocarditis

To explore the impact of hydrogen sulfide (H2S) on the heme oxygenase—1 (HO—1)/carbon monoxide (CO) system in coxsackie virus B3 (CVB3)—induced myocarditis. A total of 80 Balb/c mice were divided randomly into four groups designated N, C, P and S. Group N served as the negative control while groups C, P, and S were infected with CVB3 to induce myocarditis. Group P was additionally treated with DL—propargylglycine (PAG) to inhibit the generation of H2S while Group S was treated with NaHS, an H2S donor. Ten days after infection, heart sections were scored for histopathology. We also measured carboxyhemoglobin (COHb) levels in the blood and HO—1 expression by immunohistochemistry. 1. Each CVB3—infected group (C, P, and S) exhibited increased pathology, COHb levels, and HO—1 expression compared to uninfected controls. 2. Regarding histopathology, the score of group P was worse, while that of group S was better, than that of group C. 3. The P group COHb level was lower than group C, while the S group COHb level was higher than group C. 4. Positive HO—1 expression was seen in group C with reduced expression in group P and increased expression in group S. 5. A positive correlation was observed between the COHb concentration and HO—1expression; alternatively, a negative correlation was found between the histopathologic scores and both the concentration of COHb and the expression level of HO—1. Modulation of H2S can play a regulatory role in the pathogenesis of VMC by impacting the HO—1/CO pathway.

How do hosts react to endosymbionts? A new insight into the molecular mechanisms underlying the Wolbachia-host association

Wolbachia is an intracellular bacterium that has aroused intense interest because of its ability to alter the biology of its host in diverse ways. In the two-spotted spider mite, Tetranychus urticae, Wolbachia can induce complex cytoplasmic incompatibility (CI) phenotypes and fitness changes, although little is known about the mechanisms. In the present study, we selected a strain of T. urticae, in which Wolbachia infection was associated with strong CI and enhanced female fecundity, to investigate changes in the transcriptome of T. urticae in Wolbachia-infected vs. uninfected lines. The responses were found to be sex-specific, with the transcription of 251 genes being affected in females and 171 genes being affected in males. Some of the more profoundly affected genes in both sexes were lipocalin genes and genes involved in oxidation reduction, digestion and detoxification. Several of the differentially expressed genes have potential roles in reproduction. Interestingly, unlike certain Wolbachia transinfections in novel hosts, the Wolbachia-host association in the present study showed no clear evidence of host immune priming by Wolbachia, although a few potential immune genes were affected.

Incidence and factors associated with nosocomial infections in a neonatal intensive care unit (NICU) of an urban children's hospital in China

OBJECTIVE

The study's aim was to assess incidence and epidemiologic profile of nosocomial infection (NI) in a NICU of China, and to identify main risk factors of NIs.

MATERIALS AND METHODS

Chi square test for discrete variables and independent t-test for continuous variables to examine the association with NI. Univariate regression model was applied to the variables to predict the NI status. Finally the multivariate model was utilized with stepwise methods included all variables in the univariate model to extrapolate the independent variables to NI.

RESULTS

Infection rate in NICU during the study period was 6.2 episodes per 100 patients. Infection density was 4.2 episodes per 1,000 patient-days. Infection rate of ventilation-related pneumonia was 3.4 episodes per 1,000 mechanical ventilation (MV) days. Central line-associated bloodstream infection rate was 5.4 episodes per 1,000 central line days. Gestational age < 32 weeks, with congenital malformation, twins or triplets, gastric tube feeding, operation, duration of prophylaxis antibiotic use, duration of probiotic use, duration of parenteral nutrition were the risk factors associated with NI in NICU. We discussed the association between intrinsic factors of infants and health care procedures with NI.

CONCLUSION

This study provided information for prevention strategies of NI, that will ultimately improve the healthcare service level.

Classification of Streptomyces phylogroup pratensis (Doroghazi and Buckley, 2010) based on genetic and phenotypic evidence, and proposal of Streptomyces pratensis sp. nov

The Streptomyces phylogroup pratensis (Doroghazi and Buckley, 2010) contains isolates obtained from grassy fields, as well as Streptomyces flavogriseus ATCC 33331 and strain CGMCC 4.1868. This latter strain was received as Streptomyces griseoplanus but was subsequently found to be mislabeled, and S. flavogriseus ATCC 33331 (=IAF-45-CD) was shown to be clearly distinct from the type strain S. flavogriseus ATCC 25452(T) (=CGMCC 4.1884(T)). In order to evaluate the taxonomic position of phylogroup pratensis further, sequences of the 16S rRNA gene and five protein-coding housekeeping genes (atpD, gyrB, recA, rpoB and trpB) were determined for six strains of the phylogroup and type strains of 19 related species, which were selected by a BLAST search based on the sequences of the phylogroup. The 16S rRNA gene sequences for the phylogroup were identical to those of eight species belonging to cluster I of the S. griseus clade. However, in all the individual protein-coding gene and MLSA phylogenies, the phylogroup strains without exception formed an obviously distinct cluster that could be equated with a new species status. The phylogenetic evidence for the new species assignment was also supported by corresponding DNA-DNA hybridization values and by phenotypic characteristics. It is therefore proposed that the phylogroup should be classified as Streptomyces pratensis sp. nov., and the type strain is ch24(T) (=CGMCC 4.6829(T)=NRRL B-24916(T)).

Femtoliter-scale patterning by high-speed, highly scaled inverse gravure printing

Pattern printing techniques have advanced rapidly in the past decade, driven by their potential applications in printed electronics. Several printing techniques have realized printed features of 10 μm or smaller, but unfortunately, they suffer from disadvantages that prevent their deployment in real applications; in particular, process throughput is a significant concern. Direct gravure printing is promising in this regard. Gravure printing delivers high throughput and has a proven history of being manufacturing worthy. Unfortunately, it suffers from scalability challenges because of limitations in roll manufacturing and limited understanding of the relevant printing mechanisms. Gravure printing involves interactions between the ink, the patterned cylinder master, the doctor blade that wipes excess ink, and the substrate to which the pattern is transferred. As gravure-printed features are scaled, the associated complexities are increased, and a detailed study of the various processes involved is lacking. In this work, we report on various gravure-related fluidic mechanisms using a novel highly scaled inverse direct gravure printer. The printer allows the overall pattern formation process to be studied in detail by separating the entire printing process into three sequential steps: filling, wiping, and transferring. We found that pattern formation by highly scaled gravure printing is governed by the wettability of the ink to the printing plate, doctor blade, and substrate. These individual functions are linked by the apparent capillary number (Ca); the printed volume fraction (φ(p)) of a feature can be constructed by incorporating these basis functions. By relating Ca and φ(p), an optimized operating point can be specified, and the associated limiting phenomena can be identified. We used this relationship to find the optimized ink viscosity and printing speed to achieve printed polymer lines and line spacings as small as 2 μm at printing speeds as high as ∼1 m/s.

Streptomyces atacamensis sp. nov., isolated from an extreme hyper-arid soil of the Atacama Desert, Chile

The taxonomic position of a Streptomyces strain isolated from an extreme hyper-arid soil sample collected from the Atacama Desert was determined using a polyphasic approach. The strain, isolate C60T, had chemical and morphological features typical of members of the genus Streptomyces and formed a distinct phyletic line in the Streptomyces 16S rRNA gene tree, together with the type strain of Streptomyces radiopugnans . The two strains were distinguished readily using a combination of phenotypic properties and by a DNA–DNA relatedness value of 23.17 (±0.95) %. On the basis of these genotypic and phenotypic data, it is proposed that isolate C60T ( = CGMCC 4.7018T = KACC 15492T) be classified in the genus Streptomyces as Streptomyces atacamensis sp. nov.

Streptomyces chlorus sp. nov. and Streptomyces viridis sp. nov., isolated from soil

Two actinomycete strains, BK125(T) and BK199(T), isolated from a hay meadow soil sample were investigated to determine their taxonomic position using a polyphasic approach. The isolates produced greenish-yellow and light green aerial mycelium on oatmeal agar, respectively. They contained anteiso-C15 : 0, iso-C15 : 0 and C16 : 0 as the major fatty acids, and MK-9 (H6) and MK-9 (H8) as the predominant isoprenoid quinones. Phylogenetic analysis of the 16S rRNA gene sequences showed that the isolates formed distinct phyletic lines towards the periphery of the Streptomyces prasinus subclade. Analysis of DNA-DNA relatedness between the two isolates showed that they belonged to different genomic species. The organisms were also distinguished from one another and from type strains of species classified in the S. prasinus subclade using a combination of genotypic and phenotypic properties. On the basis of these data, it is proposed that the isolates be assigned to the genus Streptomyces as Streptomyces chlorus sp. nov. and Streptomyces viridis sp. nov. with isolates BK125(T) ( = KACC 20902(T) = CGMCC 4.5798(T)) and BK199(T) ( = KACC 21003(T) = CGMCC 4.6824(T)) as the respective type strains.

Taxonomic evaluation of the Streptomyces hygroscopicus clade using multilocus sequence analysis and DNA-DNA hybridization, validating the MLSA scheme for systematics of the whole genus

Streptomyces hygroscopicus and related species are the most well known candidate producers of antibiotics and many other industrially and agronomically important secondary metabolites in the genus Streptomyces. Multilocus sequence analysis (MLSA) has shown to be a powerful and pragmatic molecular method for unraveling streptomycete diversities. In this investigation, a multilocus phylogeny of 58 representatives of the S. hygroscopicus 16S rRNA gene clade including S. violaceusniger and related species was examined. The result demonstrated that the MLSA data were helpful in defining members of the S. hygroscopicus clade, providing further evidence that the MLSA scheme of five housekeeping genes (atpD, gyrB, recA, rpoB and trpB) is a valuable alternative for creating and maintaining operational protocols for the Streptomyces species assignment. DNA-DNA hybridization (DDH) between strains with representative MLSA evolutionary distances, combined with previous data from S. griseus and S. albidoflavus clades, revealed a high correlation between MLSA and DDH, and sustains that the five-gene nucleotide sequence distance of 0.007 could be considered as the species cut-off for the whole genus. This significant correlation thus makes the MLSA scheme applicable to construction of a theory-based taxonomy for both ecology and bioprospecting of streptomycetes. Based on the MLSA and DDH data, as well as phenotypic characteristics, 10 species and three subspecies of the S. hygroscopicus clade are considered to be later heterotypic synonyms of eight genomic species, and Streptomyces glebosus sp. nov., comb. nov. (type strain CGMCC 4.1873(T)=LMG 19950(T)=DSM 40823(T)) and Streptomyces ossamyceticus sp. nov., comb. nov. (type strain CGMCC 4.1866(T)=LMG 19951(T)=DSM 40824(T)) are also proposed.

Azilsartan treatment improves insulin sensitivity in obese spontaneously hypertensive Koletsky rats

AIM

Hypertension often coexists with insulin resistance. However, most metabolic effects of the antihypertensive agents have been investigated in nomotensive animals, in which different conclusions may arise. We investigated the metabolic effects of the new angiotensin II type 1 receptor blocker azilsartan using the obese Koletsky rats superimposed on the background of the spontaneously hypertensive rats.

METHODS

Male Koletsky rats were treated with azilsartan (2 mg/kg/day) over 3 weeks. Blood pressure was measured by tail-cuff. Blood biochemical and hormonal parameters were determined by enzymatic or ELISA methods. Gene expression was assessed by RT-PCR.

RESULTS

In Koletsky rats, azilsartan treatment lowered blood pressure, basal plasma insulin concentration and the homeostasis model assessment of insulin resistance index, and inhibited over-increase of plasma glucose and insulin concentrations during oral glucose tolerance test. These effects were accompanied by decreases in both food intake and body weight (BW) increase. Although two treatments showed the same effect on BW gain, insulin sensitivity was higher after azilsartan treatment than pair-feeding. Azilsartan neither affected plasma concentrations of triglyceride and free fatty acids, nor increased adipose mRNA levels of peroxisome proliferator-activated receptor (PPAR)γ and its target genes such as adiponectin, aP2. In addition, azilsartan downregulated 11β-hydroxysteroid dehydrogenase type 1 expression.

CONCLUSIONS

These results show the insulin-sensitizing effect of azilsartan in obese Koletsky rats. This effect is independent of decreases in food intake and BW increase or of the activation of adipose PPARγ. Our findings indicate the possible usefulness of azilsartan in the treatment of metabolic syndrome.

Streptomyces herbaceus sp. nov., Streptomyces incanus sp. nov. and Streptomyces pratens sp. nov., isolated from the soil of a hay meadow

The taxonomic positions of three streptomycetes isolated from a soil sample from a hay meadow were determined using a polyphasic approach. The isolates had chemical and morphological properties typical of the genus Streptomyces and, in phylogenetic analyses based on 16S rRNA gene sequences, formed a distinct subclade that was most closely related to the Streptomyces prasinus subclade. DNA-DNA relatedness studies showed that the novel strains belonged to three different genomic species. The novel strains could be distinguished from one another and from the type strains of the species classified in the S. prasinus subclade using a combination of genotypic and phenotypic properties. On the basis of these data, it is proposed that the novel strains be assigned to the genus Streptomyces as Streptomyces herbaceus sp. nov., Streptomyces incanus sp. nov. and Streptomyces pratens sp. nov., with BK119(T) ( = KACC 21001(T)  = CGMCC 4.5797(T)), BK128(T) ( = KACC 21002(T)  = CGMCC 4.5799(T)) and BK138(T) ( = KACC 20904(T)  = CGMCC 4.5800(T)) as the respective type strains.

Fluorescence in situ hybridization on plant extended chromatin DNA fibers for single-copy and repetitive DNA sequences

The compactness of plant chromosomes and the structure of the plant cell wall and cytoplasm provide a great obstacle to fluorescence in situ hybridization (FISH) for single-copy or low-copy DNA sequences. Consequently, many new methods for improving spatial resolution via chromosomal stretching have been employed to overcome this technical challenge. In this article, a technique for extracting cell-wall free nuclei at mitotic interphase, then using these nuclei to prepare extended DNA fibers (EDFs) by the method of a receding interface, whereby slide-mounted chromatin produces EDFs in concert with gravity-assisted buffer flow, was adopted as a result of the low frequency of EDF damage produced by this procedure. To examine the quality of these EDFs, we used single-copy gene encoding S-locus receptor kinase and multi-copy 5S rDNA (ribosomal DNA) as probes. The resulting EDFs proved suitable for high-resolution FISH mapping for repetitive DNA sequences, and the localization of a single-copy locus.