F-9775A and F-9775B are cathepsin K inhibitors that arise from a chromatin remodelling deletant strain of Aspergillus nidulans. A polyketide synthase gene has been determined to be responsible for their formation and for the simpler, archetypical polyketide orsellinic acid. We have discovered simple culture conditions that result in the production of the three compounds, and this facilitates analysis of the genes responsible for their synthesis. We have now analysed the F9775/orsellinic acid gene cluster using a set of targeted deletions. We find that the polyketide synthase alone is required for orsellinic acid biosynthesis and only two additional genes in the cluster are required for F9775 A and B synthesis. Our deletions also yielded the bioactive metabolites gerfelin and diorcinol.
The sequencing of Aspergillus genomes has revealed that the products of a large number of secondary metabolism pathways have not yet been identified. This is probably because many secondary metabolite gene clusters are not expressed under normal laboratory culture conditions. It is, therefore, important to discover conditions or regulatory factors that can induce the expression of these genes. We report that the deletion of sumO, the gene that encodes the small ubiquitin-like protein SUMO in A. nidulans, caused a dramatic increase in the production of the secondary metabolite asperthecin and a decrease in the synthesis of austinol/dehydroaustinol and sterigmatocystin. The overproduction of asperthecin in the sumO deletion mutant has allowed us, through a series of targeted deletions, to identify the genes required for asperthecin synthesis. The asperthecin biosynthesis genes are clustered and include genes encoding an iterative type I polyketide synthase, a hydrolase, and a monooxygenase. The identification of these genes allows us to propose a biosynthetic pathway for asperthecin.
In Aspergillus nidulans, cytoplasmic dynein and NUDF/LIS1 are found at the spindle poles during mitosis, but they seem to be targeted to this location via different mechanisms. The spindle pole localization of cytoplasmic dynein requires the function of the anaphase-promoting complex (APC), whereas that of NUDF does not. Moreover, although NUDF's localization to the spindle poles does not require a fully functional dynein motor, the function of NUDF is important for cytoplasmic dynein's targeting to the spindle poles. Interestingly, a γ-tubulin mutation, mipAR63, nearly eliminates the localization of cytoplasmic dynein to the spindle poles, but it has no apparent effect on NUDF's spindle pole localization. Live cell analysis of the mipAR63 mutant revealed a defect in chromosome separation accompanied by unscheduled spindle elongation before the completion of anaphase A, suggesting that γ-tubulin may recruit regulatory proteins to the spindle poles for mitotic progression. In A. nidulans, dynein is not apparently required for mitotic progression. In the presence of a low amount of benomyl, a microtubule-depolymerizing agent, however, a dynein mutant diploid strain exhibits a more pronounced chromosome loss phenotype than the control, indicating that cytoplasmic dynein plays a role in chromosome segregation.
Recent data from multiple organisms indicate that γ-tubulin has essential, but incompletely defined, functions in addition to nucleating microtubule assembly. To investigate these functions, we examined the phenotype of mipAD159, a cold-sensitive allele of the γ-tubulin gene of Aspergillus nidulans. Immunofluorescence microscopy of synchronized material revealed that at a restrictive temperature mipAD159 does not inhibit mitotic spindle formation. Anaphase A was inhibited in many nuclei, however, and after a slight delay in mitosis (∼6% of the cell cycle period), most nuclei reentered interphase without dividing. In vivo observations of chromosomes at a restrictive temperature revealed that mipAD159 caused a failure of the coordination of late mitotic events (anaphase A, anaphase B, and chromosomal disjunction) and nuclei reentered interphase quickly even though mitosis was not completed successfully. Time-lapse microscopy also revealed that transient mitotic spindle abnormalities, in particular bent spindles, were more prevalent in mipAD159 strains than in controls. In experiments in which microtubules were depolymerized with benomyl, mipAD159 nuclei exited mitosis significantly more quickly (as judged by chromosomal condensation) than nuclei in a control strain. These data reveal that γ-tubulin has an essential role in the coordination of late mitotic events, and a microtubule-independent function in mitotic checkpoint control.
The tinA gene of Aspergillus nidulans encodes a protein
that interacts with the NIMA mitotic protein kinase in a cell cycle-specific
manner. Highly similar proteins are encoded in Neurospora crassa and
Aspergillus fumigatus. TINA and NIMA preferentially interact in
interphase and larger forms of TINA are generated during mitosis. Localization
studies indicate that TINA is specifically localized to the spindle pole
bodies only during mitosis in a microtubule-dependent manner. Deletion of
tinA alone is not lethal but displays synthetic lethality in
combination with the anaphase-promoting complex/cyclosome mutation
bimE7. At the bimE7 metaphase arrest point, lack of TINA
enhanced the nucleation of bundles of cytoplasmic microtubules from the
spindle pole bodies. These microtubules interacted to form spindles joined in
series via astral microtubules as revealed by live cell imaging. Because TINA
is modified and localizes to the spindle pole bodies at mitosis, and lack of
TINA causes enhanced production of cytoplasmic microtubules at metaphase
arrest, we suggest TINA is involved in negative regulation of the astral
microtubule organizing capacity of the spindle pole bodies during
In many important organisms, including many algae and most fungi, the nuclear envelope does not disassemble during mitosis. This fact raises the possibility that mitotic onset and/or exit might be regulated, in part, by movement of important mitotic proteins into and out of the nucleoplasm. We have used two methods to determine whether tubulin levels in the nucleoplasm are regulated in the fungus Aspergillus nidulans. First, we have used benomyl to disassemble microtubules and create a pool of free tubulin that can be readily observed by immunofluorescence. We find that tubulin is substantially excluded from interphase nuclei, but is present in mitotic nuclei. Second, we have observed a green fluorescent protein/α-tubulin fusion in living cells by time-lapse spinning-disk confocal microscopy. We find that tubulin is excluded from interphase nuclei, enters the nucleus seconds before the mitotic spindle begins to form, and is removed from the nucleoplasm during the M-to-G1 transition. Our data indicate that regulation of intranuclear tubulin levels plays an important, perhaps essential, role in the control of mitotic spindle formation in A. nidulans. They suggest that regulation of protein movement into the nucleoplasm may be important for regulating mitotic onset in organisms with intranuclear mitosis.
We identified four mutations in two previously undescribed loci involved in microtubule function in Aspergillus nidulans as extragenic suppressors of benA33, a heat-sensitive beta-tubulin mutation. Three of the four mutations map to a locus closely linked to riboB on linkage group VIII; we designated this locus mipA (for microtubule-interacting protein). We were not able to map the remaining suppressor because of chromosomal rearrangements. However, since it recombines with riboB at a significantly higher frequency than the mipA alleles, it is unlikely to be in mipA; thus, we designated it mipB1. The mip mutations are not allelic to the previously identified loci that encode alpha- and beta-tubulin, and it is likely that mipA and mipB encode previously unidentified nontubulin proteins involved in microtubule function. Each of the mip mutations suppresses the heat sensitivity conferred by benA33 and suppresses the blockage of nuclear division and movement conferred by this mutation at high temperatures. Interactions between mipA and benA are allele specific. All of the mipA mutations are cryptic in a wild-type benA background but cause cold sensitivity in combination with benA33. These mutations also confer cold sensitivity in combination with benA31 and benA32 and reduce the resistance conferred by these mutations to the antimicrotubule agent benomyl but do not suppress the heat sensitivity conferred by these alleles. Finally, the mipA alleles suppress the heat sensitivity conferred by benA11, benA17, and benA21 but do not confer cold sensitivity in combination with these alleles.
The outcome of 54 pregnancies in 23 patients with hypertrophic cardiomyopathy was analysed. No mother or infant died in the perinatal period. Six patients developed dyspnoea requiring treatment with diuretics. Beta-adrenergic blocking drugs were given in 18 pregnancies and three of the infants in this were small for dates and in two fetal bradycardia occurred. The results comfirmed that pregnancy is safe in patients with hypertrophic cardiomyopathy. A flexible approach should be adopted towards administering beta-adrenergic blocking drugs to pregnant women with hypertrophic cardiomyopathy. Many such patients do well without these drugs and can thus avoid the potential hazards--namely, small-for-dates babies and fetal bradycardia--that are associated with them.
Previous research has found that a γ-tubulin mutation in Schizosaccharomyces pombe is synthetically lethal with a deletion of the C-terminal motor domain kinesin-like protein gene pkl1, but the lethality of the double mutant prevents a phenotypic analysis of the synthetic interaction. We have investigated interactions between klpA1, a deletion of an Aspergillus nidulans homolog of pkl1, and mutations in the mipA, γ-tubulin gene. We find that klpA1 dramatically increases the cold sensitivity and slightly reduces the growth rate at all temperatures, of three mipA alleles. In synchronized cells we find that klpA1 causes a substantial but transient inhibition of the establishment of spindle bipolarity. At a restrictive temperature, mipAD123 causes a slight, transient inhibition of spindle bipolarity and a more significant inhibition of anaphase A. In the mipAD123/klpA1 strain, formation of bipolar spindles is more strongly inhibited than in the klpA1 single mutant and many spindles apparently never become bipolar. These results indicate, surprisingly, that γ-tubulin and the klpA kinesin have overlapping roles in the establishment of spindle bipolarity. We propose a model to account for these data.
We have created 41 clustered charged-to-alanine scanning mutations
of the mipA, γ-tubulin, gene of Aspergillus
nidulans and have created strains carrying these mutations by
two-step gene replacement and by a new procedure, heterokaryon gene
replacement. Most mutant alleles confer a wild-type phenotype, but
others are lethal or conditionally lethal. The conditionally lethal
alleles exhibit a variety of phenotypes under restrictive conditions.
Most have robust but highly abnormal mitotic spindles and some have
abnormal cytoplasmic microtubule arrays. Two alleles appear to have
reduced amounts of γ-tubulin at the spindle pole bodies and
nucleation of spindle microtubule assembly may be partially inhibited.
One allele inhibits germ tube formation. The cold sensitivity of two
alleles is strongly suppressed by the antimicrotubule agents benomyl
and nocodazole and a third allele is essentially dependent on these
compounds for growth. Together our data indicate that γ-tubulin
probably carries out functions essential to mitosis and organization of
cytoplasmic microtubules in addition to its well-documented role in
microtubule nucleation. We have also placed our mutations on a model of
the structure of γ-tubulin and these data give a good initial
indication of the functionally important regions of the molecule.
NUT midline carcinoma (NMC) is a poorly differentiated squamous cancer characterized by rearrangement of the NUT gene. Research advances have provided opportunities for targeted therapy in NMC, yet the clinical features of this rare disease have not been systematically characterized. We report on a large population of such patients to identify the disease characteristics and treatments, correlate them with outcome, and to consider clinical recommendations.
A clinical database was established using retrospective demographic and outcomes data available on all known cases of NMC. Questionnaires were completed by treating physicians. Pathologic, demographic, and clinical variables were assessed for 63 patients, the largest cohort of NMC patients studied to date. Outcome data from 54 patients were available for survival analyses.
The diagnosis of NMC has increased annually since 2007. Since 2009, there has been an observed increase in the age at diagnosis (p<0.05). Geographic distribution of NMC patients has been concentrated in the United States (n=41, 65%). The median overall survival for patients with NMC was 6.7 months. The 2-year progression-free survival (PFS) was 9% with a 95% CI of 1%–17% (1-year PFS 15% (5%–24%)) and 2-year overall survival (OS) was 19% with a 95% CI of 7%–31% (1-year OS: 30% (27%–34%). Multivariate analysis suggested that extent of surgical resection and initial radiotherapy were independent predictors of PFS and OS. Notably, no chemotherapeutic regimen was associated with improved outcome.
NMC portends a poor prognosis among all squamous cell neoplasms and appears to be frequently unrecognized. The finding that conventional chemotherapy has been inadequate indicates a pressing need for the development of targeted therapeutics. Intensive local therapies such as gross total resection and radiotherapy might be associated with enhanced survival.
NUT midline carcinoma; outcomes; registry
All vertebrate nervous systems, except those of agnathans, make extensive use of the myelinated fiber, a structure formed by coordinated interplay between neuronal axons and glial cells. Myelinated fibers, by enhancing the speed and efficiency of nerve cell communication allowed gnathostomes to evolve extensively, forming a broad range of diverse lifestyles in most habitable environments. The axon-covering myelin sheaths are structurally and biochemically novel as they contain high portions of lipid and a few prominent low molecular weight proteins often considered unique to myelin. Here we searched genome and EST databases to identify orthologs and paralogs of the following myelin-related proteins: (1) myelin basic protein (MBP), (2) myelin protein zero (MPZ, formerly P0), (3) proteolipid protein (PLP1, formerly PLP), (4) peripheral myelin protein-2 (PMP2, formerly P2), (5) peripheral myelin protein-22 (PMP22) and (6) stathmin-1 (STMN1). Although widely distributed in gnathostome/vertebrate genomes, neither MBP nor MPZ are present in any of nine invertebrate genomes examined. PLP1, which replaced MPZ in tetrapod CNS myelin sheaths, includes a novel ‘tetrapod-specific’ exon (see also Möbius et al., 2009). Like PLP1, PMP2 first appears in tetrapods and like PLP1 its origins can be traced to invertebrate paralogs. PMP22, with origins in agnathans, and STMN1 with origins in protostomes, existed well before the evolution of gnathostomes. The coordinated appearance of MBP and MPZ with myelin sheaths and of PLP1 with tetrapod CNS myelin suggests interdependence – new proteins giving rise to novel vertebrate structures.
Myelin basic protein; myelin protein zero; PMP22; PMP2; stathmin
One-third of public school students are racial and/or ethnic minorities. Yet only 14 per cent of teachers represent these groups. Frequently lost in broader debates concerning this disparity is the paradoxical contribution of the 1954 Brown v. Board of Education decision. Schools were mandated under Brown to desegregate the student body. But the law did not necessarily protect the jobs of black teachers and administrators. Using a unique database of court orders, we examine the impact of mandated desegregation on black teachers. Findings indicate regional differences. Mandated desegregation created conditions that resulted in decreases in the black teaching force in the South. The opposite occurred in the nonsouth, with mandated desegregation positively associated with increases (although small) in the black teaching force. Our findings suggest that the legacy of mandated desegregation may have created broader institutional conditions in which black and other minority teachers remain underrepresented in the teaching force.
Education; United States; policy; black teachers; desegregation; public schools
Nanoparticle vaccines were produced using layer-by-layer fabrication and incorporating respiratory syncytial virus (RSV) G protein polypeptides comprising the CX3C chemokine motif. BALB/c mice immunized with G protein nanoparticle vaccines produced a neutralizing antibody response that inhibited RSV replication in the lungs following RSV challenge. ELISPOT analysis showed that G nanoparticle vaccinated mice had increased levels of RSV G protein-specific IL-4 and IFN-γ secreting cells compared to controls following RSV challenge. Remarkably, RSV challenge of G protein nanoparticle vaccinated mice resulted in increased RSV M2-specific IL-4 and IFN-γ secreting T cells, and increased M2-specific H-2Kd-tetramer positive CD8+ T cells in the lungs compared to controls. Cell type analysis showed vaccination was not associated with increased pulmonary eosinophilia following RSV challenge. These results demonstrate that vaccination of mice with the RSV G protein nanoparticle vaccines induces a potent neutralizing antibody response, increased G protein- and M2- specific T cell responses, and a reduction in RSV disease pathogenesis.
Soil carbon (C) storage is dependent upon the complex dynamics of fresh and native organic matter cycling, which are regulated by plant and soil-microbial activities. A fundamental challenge exists to link microbial biodiversity with plant-soil C cycling processes to elucidate the underlying mechanisms regulating soil carbon. To address this, we contrasted vegetated grassland soils with bare soils, which had been plant-free for 3 years, using stable isotope (13C) labeled substrate assays and molecular analyses of bacterial communities. Vegetated soils had higher C and N contents, biomass, and substrate-specific respiration rates. Conversely, following substrate addition unlabeled, native soil C cycling was accelerated in bare soil and retarded in vegetated soil; indicative of differential priming effects. Functional differences were reflected in bacterial biodiversity with Alphaproteobacteria and Acidobacteria dominating vegetated and bare soils, respectively. Significant isotopic enrichment of soil RNA was found after substrate addition and rates varied according to substrate type. However, assimilation was independent of plant presence which, in contrast to large differences in 13CO2 respiration rates, indicated greater substrate C use efficiency in bare, Acidobacteria-dominated soils. Stable isotope probing (SIP) revealed most community members had utilized substrates with little evidence for competitive outgrowth of sub-populations. Our findings support theories on how plant-mediated soil resource availability affects the turnover of different pools of soil carbon, and we further identify a potential role of soil microbial biodiversity. Specifically we conclude that emerging theories on the life histories of dominant soil taxa can be invoked to explain changes in soil carbon cycling linked to resource availability, and that there is a strong case for considering microbial biodiversity in future studies investigating the turnover of different pools of soil carbon.
upland acidic grassland; bacteria; substrate-specific respiration; priming effects; substrate carbon use efficiency; T-RFLP; RNA stable isotope probing; soil organic carbon
Background and aims
Transdifferentiation of hepatic stellate cells (HSCs) to a myofibroblast-like phenotype is a pivotal event that drives liver fibrosis. HSC transdifferentiation requires coordinated global changes in gene expression. Here we have investigated epigenetic regulators that orchestrate HSC transdifferentiation.
Expression profiling of epigenetic regulators was carried out in primary quiescent HSC and myofibroblasts by qRT-PCR. Recruitment of histone modifying enzymes (MLL5, Set1 and ASH1) to fibrogenic genes was determined by chromatin immunoprecipitation (ChIP). Functional studies on ASH1 were carried out by depletion of the protein by siRNA. Function of the ASH1 regulator, MeCP2, was determined in myofibroblastic HSC.
The lysine 4 Histone 3 (H3K4) methyltransferases MLL5, Set1 and ASH1 were highly up-regulated during HSC transdifferentiation. H3K4 trimethylation at 5’ end of the gene is a signature of active transcription. ASH1, but not MLL5 or Set1, was recruited to the regulatory regions of αSMA, collagen I, TIMP1 and TGFβ1. Depletion of ASH1 in HSC-derived myofibroblasts caused broad suppression of fibrogenic gene expression. We also discovered that MeCP2 positively regulates ASH1 expression.
We identify ASH1 as a key transcriptional activator component of the MeCP2 epigenetic relay pathway that orchestrates coordinated induction of multiple pro-fibrogenic genes.
Epigenetic regulation; HSC; MeCP2; H3K4 methylation; liver fibrosis
Better information on the human capital costs of early-onset mental disorders could increase sensitivity of policy-makers to the value of expanding initiatives for early detection-treatment. Data are presented on one important aspect of these costs: the associations of early-onset mental disorders with adult household income.
Data come from the WHO World Mental Health (WMH) Surveys in eleven high income, five upper-middle income, and six low/lower-middle income countries. Information about 15 lifetime DSM-IV mental disorders as of age of completing education, retrospectively assessed with the WHO Composite International Diagnostic Interview, was used to predict current household income among respondents ages 18-64 (n = 37,741) controlling for level of education. Gross associations were decomposed to evaluate mediating effects through major components of household income.
Early-onset mental disorders are associated with significantly reduced household income in high and upper-middle income countries but not low/lower-middle income countries, with associations consistently stronger among women than men. Total associations are largely due to low personal earnings (increased unemployment, decreased earnings among the employed) and spouse earnings (decreased probabilities of marriage and, if married, spouse employment and low earnings of employed spouses). Individual-level effect sizes are equivalent to 16-33% of median within-country household income, while population-level effect sizes are in the range 1.0-1.4% of Gross Household Income.
Early mental disorders are associated with substantial decrements in income net of education at both individual and societal levels. Policy-makers should take these associations into consideration in making healthcare research and treatment resource allocation decisions.
epidemiology; mental disorders; early-onset; income; cross-national; WHO World Mental Health (WMH)
Background & Aims
Sinusoidal obstruction syndrome (SOS) following oxaliplatin based chemotherapy can have a significant impact on post-operative outcome following resection of colorectal liver metastases. To date no relevant experimental models of oxaliplatin induced SOS have been described. The aim of this project was to establish a rodent model which could be utilised to investigate mechanisms underlying SOS to aid the development of therapeutic strategies.
C57Bl/6 mice, maintained on a purified diet, were treated with intra-peritoneal FOLFOX (n = 10), or vehicle (n = 10), weekly for five weeks and culled one week following final treatment. Sections of the liver and spleen were fixed in formalin and paraffin embedded for histological analysis. The role of oxidative stress on experimental-induced SOS was determined by dietary supplementation with butylated hydroxyanisole and N-acetylcysteine.
FOLFOX treatment was associated with the development of sinusoidal dilatation and hepatocyte atrophy on H&E stained sections of the liver in keeping with SOS. Immunohistochemistry for p21 demonstrated the presence of replicative senescence within the sinusoidal endothelium.
FOLFOX induced endothelial damage leads to a pro-thrombotic state within the liver associated with upregulation of PAI-1 (p <0.001), vWF (p <0.01) and Factor X (p <0.001), which may contribute to the propagation of liver injury.
Dietary supplementation with the antioxidant BHA prevented the development of significant SOS.
We have developed the first reproducible model of chemotherapy induced SOS that reflects the pathogenesis of this disease in patients. It appears that the use of antioxidants alongside oxaliplatin based chemotherapy may be of value in preventing the development of SOS in patients with colorectal liver metastases.
AST, aspartate aminotransferase; ALT, alanine aminotransferase; ALP, alkaline phosphatase; BHA, butylated hydroxyanisole; CRLM, colorectal liver metastases; CXCL1/2, chemokine (C-X-C motif) ligand 1/2; GAPDH, gyceraldehyde 3-phosphate dehydrogenase; H&E, haematoxylin and eosin; HPF, high powered field; γH2AX, phosphorylated form of the H2A histone family, member X; i.p., intraperitoneal; IL-6, interleukin 6; MCP1, monocyte chemotactic protein-1; NAC, N-acetylcysteine; NRF2, nuclear factor (erythroid-derived 2)-like 2; NQO1, NAD(P)H dehydrogenase 1; PCNA, proliferating cell nuclear antigen; PAI-1, plasminogen activatior inhibitor 1; PAR 1/2, protease activated receptor 1/2; STAT3, signal transducer and activator of transcription 3; SOS, sinusoidal obstruction syndrome; TXN1, thioredoxin 1; VEGF-A/B/C, vascular endothelial growth factor A/B/C; VEGFR-1/2, vascular endothelial growth factor receptor ½; vWF, von Willebrand factor; Sinusoidal obstruction syndrome; Oxaliplatin; Colorectal liver metastases; Chemotherapy induced liver injury
Environmental mycobacteria (EM) include species commonly found in various terrestrial and aquatic environments, encompassing animal and human pathogens in addition to saprophytes. Approximately 150 EM species can be separated into fast and slow growers based on sequence and copy number differences of their 16S rRNA genes. Cultivation methods are not appropriate for diversity studies; few studies have investigated EM diversity in soil despite their importance as potential reservoirs of pathogens and their hypothesized role in masking or blocking M. bovis BCG vaccine.
We report here the development, optimization and validation of molecular assays targeting the 16S rRNA gene to assess diversity and prevalence of fast and slow growing EM in representative soils from semi tropical and temperate areas. New primer sets were designed also to target uniquely slow growing mycobacteria and used with PCR-DGGE, tag-encoded Titanium amplicon pyrosequencing and quantitative PCR.
PCR-DGGE and pyrosequencing provided a consensus of EM diversity; for example, a high abundance of pyrosequencing reads and DGGE bands corresponded to M. moriokaense, M. colombiense and M. riyadhense. As expected pyrosequencing provided more comprehensive information; additional prevalent species included M. chlorophenolicum, M. neglectum, M. gordonae, M. aemonae. Prevalence of the total Mycobacterium genus in the soil samples ranged from 2.3×107 to 2.7×108 gene targets g−1; slow growers prevalence from 2.9×105 to 1.2×107 cells g−1.
This combined molecular approach enabled an unprecedented qualitative and quantitative assessment of EM across soil samples. Good concordance was found between methods and the bioinformatics analysis was validated by random resampling. Sequences from most pathogenic groups associated with slow growth were identified in extenso in all soils tested with a specific assay, allowing to unmask them from the Mycobacterium whole genus, in which, as minority members, they would have remained undetected.
Human pluripotent stem cells are a promising source of differentiated cells for developmental studies, cell transplantation, disease modeling, and drug testing. However, their widespread use even for intensely studied cell types like spinal motor neurons is hindered by the long duration and low yields of existing protocols for in vitro differentiation and by the molecular heterogeneity of the populations generated. We report a combination of small molecules that within 3 weeks induce motor neurons at up to 50% abundance and with defined subtype identities of relevance to neurodegenerative disease. Despite their accelerated differentiation, motor neurons expressed combinations of HB9, ISL1 and column-specific markers that mirror those observed in vivo in human fetal spinal cord. They also exhibited spontaneous and induced activity, and projected axons towards muscles when grafted into developing chick spinal cord. Strikingly, this novel protocol preferentially generates motor neurons expressing markers of limb-innervating lateral motor column motor neurons (FOXP1+/LHX3−). Access to high-yield cultures of human limb-innervating motor neuron subtypes will facilitate in-depth study of motor neuron subtype-specific properties, disease modeling, and development of large-scale cell-based screening assays.
The molecule serotonin (5-hydroxytryptamine or 5-HT) is involved in numerous biological processes both inside and outside of the central nervous system. 5-HT signals through 5-HT receptors and it is the diversity of these receptors and their subtypes that give rise to the varied physiological responses. It is clear that platelet derived serotonin is critical for normal wound healing in multiple organs including, liver, lung heart and skin. 5-HT stimulates both vasoconstriction and vasodilation, influences inflammatory responses and promotes formation of a temporary scar which acts as a scaffold for normal tissue to be restored. However, in situations of chronic injury or damage 5-HT signaling can have deleterious effects and promote aberrant wound healing resulting in tissue fibrosis and impaired organ regeneration. This review highlights the diverse actions of serotonin signaling in the pathogenesis of fibrotic disease and explores how modulating the activity of specific 5-HT receptors, in particular the 5-HT2 subclass could have the potential to limit fibrosis and restore tissue regeneration. This article is part of a Special Issue entitled: Fibrosis: Translation of basic research to human disease.
► Introduction, overview of serotonin signaling and biology ► The role of serotonin in wound healing, regeneration and fibrosis ► Future perspectives
It has been argued that the effects of the desegregation of public schools from the late 1960s onward were limited and short-lived, in part because of white flight from desegregating districts and in part because legal decisions in the 1990s released many districts from court orders. Data presented here for 1970–2000 show that small increases in segregation between districts were outweighed by larger declines within districts. Progress was interrupted but not reversed after 1990. Desegregation was not limited to districts and metropolitan regions where enforcement actions required it, and factors such as private schooling, district size, and inclusion of both city and suburban areas within district boundaries had stronger effects than individual court mandates.
To identify the sociodemographic factors associated with variation in area-based breastfeeding in England; to calculate the predicted breastfeeding rates adjusted for sociodemographic variations.
Ecological analysis of routine data using random effects logistic regression.
All 151 primary care trusts (PCTs) in England 2010–2011.
PCT level data on breastfeeding: initiation, any and exclusive breastfeeding at 6–8 weeks.
There was considerable variation in breastfeeding across PCTs (breastfeeding initiation mean 72%, range 39–93%; any breastfeeding at 6–8 weeks mean 45%, range 19–83%; exclusive breastfeeding at 6–8 weeks mean 32%, range 14–58%), with London PCTs reporting markedly higher rates. Maternal age was strongly associated with area-based breastfeeding, with a 4–6% increase in odds of breastfeeding associated with a unit increase in the percentage of older mothers. Outside London, the proportion of the local population from a Black and Minority Ethnic (BME) background, compared with those from a White British background, was associated with higher breastfeeding (1–3% increase in odds per unit increase in the proportion from a BME background). Area-based deprivation was associated with reduced odds of breastfeeding (21–32% reduced odds comparing most deprived quintile to least deprived quintile). Weaker associations were observed between sociodemographic factors and breastfeeding in London PCTs. Very few PCTs reported breastfeeding figures substantially above or below the national average, having adjusted for variations in sociodemographic factors.
Our results show striking associations between sociodemographic factors and breastfeeding at the area level, with much of the variation in breastfeeding rates explained by the sociodemographic profile. The sociodemographic context of breastfeeding is clearly important at the area level as well as the individual level. Our findings can be used to inform decision-making relating to local priorities and service provision.
Breastfeeding; Public Health; Nutrition & Dietetics
The authors conducted a qualitative study of private-practice dentists in their offices by using vignette-based interviews to assess barriers to the use of evidence-based clinical recommendations in the treatment of noncavitated carious lesions.
The authors recruited 22 dentists as a convenience sample and presented them with two patient vignettes involving noncavitated carious lesions. Interviewers asked participants to articulate their thought processes as they described treatment recommendations. Participants compared their treatment plans with the American Dental Association’s recommendations for sealing noncavitated carious lesions, and they described barriers to implementing these recommendations in their practices. The authors recorded and transcribed the sessions for accuracy and themes.
Personal clinical experience emerged as the determining factor in dentists’ treatment decisions regarding noncavitated carious lesions. Additional factors were lack of reimbursement and mistrust of the recommendations. The authors found that knowledge of the recommendations did not lead to their adoption when the recommendation was incongruent with the dentist’s personal experience.
The authors found that ingrained practice behavior based on personal clinical experience that differed substantially from evidence-based recommendations resulted in a rejection of these recommendations.
Attempts to improve the adoption of evidence-based practice must involve more than simple dissemination of information to achieve a balance between personal clinical experience and scientific evidence.
Early carious lesions; evidence-based recommendations; pit-and-fissure sealants
Data are reported on the background and performance of the K6 screening scale for serious mental illness (SMI) in the World Health Organization (WHO) World Mental Health (WMH) surveys. The K6 is a 6-item scale developed to provide a brief valid screen for DSM-IV SMI based on the criteria in the US ADAMHA Reorganization Act. Although methodological studies have documented good K6 validity in a number of countries, optimal scoring rules have never been proposed. Such rules are presented here based on analysis of K6 data in nationally or regionally representative WMH surveys in 14 countries (combined n = 41,770 respondents). Twelve-month prevalence of DSM-IV SMI was assessed with the fully-structured WHO Composite International Diagnostic Interview. Nested logistic regression analysis was used to generate estimates of the predicted probability of SMI for each respondent from K6 scores taking into consideration the possibility of variable concordance as a function of respondent age, gender, education, and country. Concordance, assessed by calculating the area under the receiver operating characteristic curve (AUC), was generally substantial (Median .83; Range .76-.89; Inter-quartile range .81-.85). Based on this result, optimal scaling rules are presented for use by investigators working with the K6 scale in the countries studied.
K6 screening scale; psychiatric epidemiology; serious mental illness (SMI)