Plant stem cell maintenance by transcriptional cross-regulation of related receptor kinases

The CLAVATA3 (CLV3)-CLAVATA1 (CLV1) ligand-receptor kinase pair negatively regulates shoot stem cell proliferation in plants. clv1 null mutants are weaker in phenotype than clv3 mutants, but the clv1 null phenotype is enhanced by mutations in the related receptor kinases BARELY ANY MERISTEM 1, 2 and 3 (BAM1, 2 and 3). The basis of this genetic redundancy is unknown. Here, we demonstrate that the apparent redundancy in the CLV1 clade is in fact due to the transcriptional repression of BAM genes by CLV1 signaling. CLV1 signaling in the rib meristem (RM) of the shoot apical meristem is necessary and sufficient for stem cell regulation. CLV3-CLV1 signaling in the RM represses BAM expression in wild-type Arabidopsis plants. In clv1 mutants, ectopic BAM expression in the RM partially complements the loss of CLV1. BAM regulation by CLV1 is distinct from CLV1 regulation of WUSCHEL, a proposed CLV1 target gene. In addition, quadruple receptor mutants are stronger in phenotype than clv3, pointing to the existence of additional CLV1/BAM ligands. These data provide an explanation for the genetic redundancy seen in the CLV1 clade and reveal a novel feedback operating in the control of plant stem cells

Identification of \u3ci\u3eVibrio\u3c/i\u3e Isolates by a Multiplex PCR Assay and \u3ci\u3erpoB\u3c/i\u3e Sequence Determination

Vibrio, a diverse genus of aquatic bacteria, currently includes 72 species, 12 of which occur in human clinical samples. Of these 12, three species—Vibrio cholerae, Vibrio parahaemolyticus, and Vibrio vulnificus—account for the majority of Vibrio infections in humans. Rapid and accurate identification of Vibrio species has been problematic because phenotypic characteristics are variable within species and biochemical identification requires 2 or more days to complete. To facilitate the identification of human-pathogenic species, we developed a multiplex PCR that uses species-specific primers to amplify gene regions in four species (V. cholerae, V. parahaemolyticus, V. vulnificus, and V. mimicus). The assay was tested on a sample of 309 Vibrio isolates representing 26 named species (including 12 human pathogens) that had been characterized by biochemical methods. A total of 190 isolates that had been identified as one of the four target species all yielded results consistent with the previous classification. The assay identified an additional four V. parahaemolyticus isolates among the other 119 isolates. Sequence analysis based on rpoB was used to validate the multiplex results for these four isolates, and all clustered with other V. parahaemolyticus sequences. The rpoB sequences for 12 of 15 previously unidentified isolates clustered with other Vibrio species in a phylogenetic analysis, and three isolates appeared to represent unnamed Vibrio species. The PCR assay provides a simple, rapid, and reliable tool for identification of the major Vibrio pathogens in clinical samples, and rpoB sequencing provides an additional identification tool for other species in the genus Vibrio

Stroke Severity Predicted by Aortic Atheroma Detected by Ultra-Fast and Cardiac-Gated Chest Tomography†

Background and Purpose: The presence of aortic atherosclerosis is an independent risk factor for secondary stroke. The present study was designed to have an initial exploration of the correlation between the load and extent of aortic atheroma (AA) and initial stroke severity or clinical outcome 3 months after stroke. Methods: Cardiac-gated chest tomography (CGCT) was used to detect and measure AA in patients with acute ischemic stroke as shown by our group in prior prospective studies and this is part four sub-exploratory study of the same cohort. The National Institute of Health Stroke Scale (NIHSS) was used to assess the initial stroke severity, and the modified Rankin Scale (mRS) was used to assess 3-month outcome. Results: Thirty-two patients underwent CGCT for evaluation of AA, and 21 were found to have AA. AA was more prevalent in patient with NIHSS >6 (14/17 versus 7/15, p-value 0.03). Applying the multiple logistic regression and propensity score adjustment (using the propensity of having AA given the baseline features as covariates) showed a non-significant trend that AA is three times more likely to be associated with NIHSS >6 (p = 0.08, OR 3.08, 95% CI 0.94–13.52). There was no evidence of association of AA with 3-month functional outcome (mRS): 11/14 (78.6%) mRS >1 had AA, and 10/18 (55.5%) of those with mRS ≤1 had AA (p = 0.27). Conclusion: In our current study with limited sample number and exploratory nature, the presence of AA on CGCT with acute ischemic stroke patients may be associated with worse neurological deficit at presentation. There was no evidence of association with 3-month functional outcome using the mRS

Control of plant stem cell function by conserved interacting transcriptional regulators

Plant stem cells in the shoot apical meristem (SAM) and root apical meristem are necessary for postembryonic development of aboveground tissues and roots, respectively, while secondary vascular stem cells sustain vascular development. WUSCHEL (WUS), a homeodomain transcription factor expressed in the rib meristem of the Arabidopsis SAM, is a key regulatory factor controlling SAM stem cell populations, and is thought to establish the shoot stem cell niche through a feedback circuit involving the CLAVATA3 (CLV3) peptide signalling pathway. WUSCHEL-RELATED HOMEOBOX 5 (WOX5), which is specifically expressed in the root quiescent centre, defines quiescent centre identity and functions interchangeably with WUS in the control of shoot and root stem cell niches. WOX4, expressed in Arabidopsis procambial cells, defines the vascular stem cell niche. WUS/WOX family proteins are evolutionarily and functionally conserved throughout the plant kingdom and emerge as key actors in the specification and maintenance of stem cells within all meristems. However, the nature of the genetic regime in stem cell niches that centre on WOX gene function has been elusive, and molecular links underlying conserved WUS/WOX function in stem cell niches remain unknown. Here we demonstrate that the Arabidopsis HAIRY MERISTEM (HAM) family of transcription regulators act as conserved interacting cofactors with WUS/WOX proteins. HAM and WUS share common targets in vivo and their physical interaction is important in driving downstream transcriptional programs and in promoting shoot stem cell proliferation. Differences in the overlapping expression patterns of WOX and HAM family members underlie the formation of diverse stem cell niche locations, and the HAM family is essential for all of these stem cell niches. These findings establish a new framework for the control of stem cell production during plant development

Does menopause transition influence viral suppression and adherence in Women living with HIV?

BACKGROUND Increasing numbers of women living with HIV transition through menopause. It is unclear if this transition has an impact on treatment adherence, viral suppression, psychiatric comorbidities or drug use. We aimed at examining adherence and viral suppression during the perimenopausal period and explored the influence of psychiatric comorbidities and active injection drug use (IDU). SETTING Retrospective Swiss HIV Cohort Study analysis from 01/2010 to 12/2018. METHODS We explored peri- and postmenopausal trends of viral blips, low-level viremia, viral failure, adherence, psychiatric comorbidities and IDU using interrupted time series (ITS) models. RESULTS Rates of depression and psychiatric care increased during perimenopause before decreasing afterwards. Negative treatment outcomes such as viral blips, low-level viremia, viral failure and low adherence steadily declined while transitioning through menopause - this was also true for subgroups of women with depression, psychiatric treatment and active IDU. CONCLUSIONS Increased rates of depression and psychiatric care while transitioning through menopause do not result in lower rates of adherence or viral suppression in women living with HIV in Switzerland

A diverse panel of hepatitis C virus glycoproteins for use in vaccine research reveals extremes of monoclonal antibody neutralization resistance

Despite significant advances in the treatment of hepatitis C virus (HCV) infection, the need to develop preventative vaccines remains. Identification of the best vaccine candidates and evaluation of their performance in preclinical and clinical development will require appropriate neutralization assays utilizing diverse HCV isolates. We aimed to generate and characterize a panel of HCVE1E2 glycoproteins suitable for subsequent use in vaccine and therapeutic antibody testing. Full-length E1E2 clones were PCR amplified from patient- derived serum samples, cloned into an expression vector, and used to generate viral pseudoparticles (HCVpp). In addition, some of these clones were used to generate cell culture infectious (HCVcc) clones. The infectivity and neutralization sensitivity of these viruses were then determined. Bioinformatic and HCVpp infectivity screening of approximately 900 E1E2 clones resulted in the assembly of a panel of 78 functional E1E2 proteins representing distinct HCV genotypes and different stages of infection. These HCV glycoproteins differed markedly in their sensitivity to neutralizing antibodies. We used this panel to predict antibody efficacy against circulating HCV strains, highlighting the likely reason why some monoclonal antibodies failed in previous clinical trials. This study provides the first objective categorization of cross-genotype patient-derived HCVE1E2 clones according to their sensitivity to antibody neutralization. It has shown that HCV isolates have clearly distinguishable neutralization-sensitive, -resistant, or -intermediate phenotypes, which are independent of genotype. The panel provides a systematic means for characterization of the neutralizing response elicited by candidate vaccines and for defining the therapeutic potential of monoclonal antibodies

Cloning and Sequence Analysis of the Structural Gene for the bc 1 - Type Rieske Iron-Sulfur Protein from Thermus thermophilus HB8

The structural gene encoding the Rieske iron-sulfur protein from Thermus thermophilus HB8 has been cloned and sequenced. The gene encodes a protein of 209 amino acids that begins with a hydrophilic N-terminus followed by a stretch of 21 hydrophobic amino acids that could serve as a transmembrane helix. The remainder of the protein has a hydrophobicity pattern typical of a water-soluble protein. A phylogenetic analysis of 26 Rieske proteins that are part of bc 1 or b 6 f complexes shows that they fall into three major groups: eubacterial and mitochondrial, cyanobacterial and plastid, and five highly divergent outliers, including that of Thermus . Although the overall homology with other Rieske proteins is very low, the C-terminal half of the Thermus protein contains the signature sequence CTHLGC-(13X)-CPCH that most likely provides the ligands of the [2Fe-2S] cluster. It is proposed that this region of the protein represents a small domain that folds independently and that the encoding DNA sequence may have been transferred during evolution to several unrelated genes to provide the cluster attachment site to proteins of different origin. The role of individual residues in this domain of the Thermus protein is discussed vis-a-vis the three-dimensional structure of the bovine protein (Iwata et al ., 1996 Structure 4 , 567–579).Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/44801/1/10863_2004_Article_409077.pd

Vaccine hesitancy and HPV vaccine uptake among male and female youth in Switzerland: a cross-sectional study

OBJECTIVES: Identifying factors associated with human papillomavirus (HPV) vaccine uptake is essential for designing successful vaccination programmes. We aimed to examine the association between vaccine hesitancy (VH) and HPV vaccine uptake among male and female youth in Switzerland. DESIGN: With a cross-sectional study, an interview-based questionnaire was used to collect information on sociodemographic factors, vaccination records and to measure the prevalence of VH using the Youth Attitudes about Vaccines scale (YAV-5), a modified version of the Parent Attitudes about Childhood Vaccinations survey instrument. SETTING AND PARTICIPANTS: Eligible male and female participants, 15-26 years of age, were recruited through physicians' offices and military enlistment in all three language regions of Switzerland. Of 1001 participants, we included 674 participants with a vaccination record available (415 males and 259 females) in this study. PRIMARY AND SECONDARY OUTCOME MEASURES: The outcome was uptake for HPV vaccine (having received >/=1 dose of HPV vaccine). Covariates were VH, sex, age and other sociodemographics. RESULTS: 151 (58%) female and 64 (15%) male participants received >/=1 dose of HPV vaccine. 81 (31%) female and 92 (22%) male participants were VH (YAV-5-Score >50). The odds for being unvaccinated were higher for VH women than non-VH women, adjusted OR=4.90 (95% CI 2.53 to 9.50), but similar among VH and non-VH men, OR=1.90 (95% CI 0.84 to 4.31). The odds for being unvaccinated were lower for younger men (born on or after 1 July 2002) than older men (born before 1 July 2002), OR=0.34 (95% CI 0.14 to 0.81), but we found no association between age and vaccine uptake for female youth, OR=0.97 (95% CI 0.48 to 1.97). CONCLUSIONS: VH was associated with lower HPV vaccine uptake in female youth but not male youth in our study population in Switzerland. Our findings suggest that issues other than VH contribute to HPV underimmunisation in male youth in Switzerland