218 research outputs found
Transcriptional profiling of the epigenetic regulator Smchd1
Available online 31 December 2015Smchd1 is an epigenetic repressor with important functions in healthy cellular processes and disease. To elucidate its role in transcriptional regulation, we performed two independent genome-wide RNA-sequencing studies comparing wild-type and Smchd1 null samples in neural stem cells and lymphoma cell lines. Using an R-based analysis pipeline that accommodates observational and sample-specific weights in the linear modeling, we identify key genes dysregulated by Smchd1 deletion such as clustered protocadherins in the neural stem cells and imprinted genes in both experiments. Here we provide a detailed description of this analysis, from quality control to read mapping and differential expression analysis. These data sets are publicly available from the Gene Expression Omnibus database (accession numbers GSE64099 and GSE65747).Ruijie Liu, Kelan Chen, Natasha Jansz, Marnie E. Blewitt, Matthew E. Ritchi
Reversibility of Frailty After Bridge-to-Transplant Ventricular Assist Device Implantation or Heart Transplantation.
BACKGROUND: We recently reported that frailty is independently predictive of increased mortality in patients with advanced heart failure referred for heart transplantation (HTx). The aim of this study was to assess the impact of frailty on short-term outcomes after bridge-to-transplant ventricular assist device (BTT-VAD) implantation and/or HTx and to determine if frailty is reversible after these procedures. METHODS: Between August 2013 and August 2016, 100 of 126 consecutive patients underwent frailty assessment using Fried's Frailty Phenotype before surgical intervention: 40 (21 nonfrail, 19 frail) BTT-VAD and 77 (60 nonfrail, 17 frail) HTx-including 17 of the 40 BTT-VAD supported patients. Postprocedural survival, intubation time, intensive care unit, and hospital length of stay were compared between frail and nonfrail groups. Twenty-six frail patients were reassessed at 2 months or longer postintervention. RESULTS: Frail patients had lower survival (63 ± 10% vs 94 ± 3% at 1 year, P = 0.012) and experienced significantly longer intensive care unit (11 vs 5 days, P = 0.002) and hospital (49 vs 25 days, P = 0.003) length of stay after surgical intervention compared with nonfrail patients. Twelve of 13 frail patients improved their frailty score after VAD (4.0 ± 0.8 to 1.4 ± 1.1, P < 0.001) and 12 of 13 frail patients improved their frailty score after HTx (3.2 ± 0.4 to 0.9 ± 0.9, P < 0.001). Handgrip strength and depression improved postintervention. Only a slight improvement in cognitive function was seen postintervention. CONCLUSIONS: Frail patients with advanced heart failure experience increased mortality and morbidity after surgical intervention with BTT-VAD or HTx. Among those who survive frailty is partly or completely reversible underscoring the importance of considering this factor as a dynamic not fixed entity
Setdb1-mediated H3K9 methylation is enriched on the inactive X and plays a role in its epigenetic silencing
Background: The presence of histone 3 lysine 9 (H3K9) methylation on the mouse inactive X chromosome has been controversial over the last 15 years, and the functional role of H3K9 methylation in X chromosome inactivation in any species has remained largely unexplored. Results: Here we report the first genomic analysis of H3K9 di- and tri-methylation on the inactive X: we find they are enriched at the intergenic, gene poor regions of the inactive X, interspersed between H3K27 tri-methylation domains found in the gene dense regions. Although H3K9 methylation is predominantly non-genic, we find that depletion of H3K9 methylation via depletion of H3K9 methyltransferase Set domain bifurcated 1 (Setdb1) during the establishment of X inactivation, results in failure of silencing for around 150 genes on the inactive X. By contrast, we find a very minor role for Setdb1-mediated H3K9 methylation once X inactivation is fully established. In addition to failed gene silencing, we observed a specific failure to silence X-linked long-terminal repeat class repetitive elements. Conclusions: Here we have shown that H3K9 methylation clearly marks the murine inactive X chromosome. The role of this mark is most apparent during the establishment phase of gene silencing, with a more muted effect on maintenance of the silent state. Based on our data, we hypothesise that Setdb1-mediated H3K9 methylation plays a role in epigenetic silencing of the inactive X via silencing of the repeats, which itself facilitates gene silencing through alterations to the conformation of the whole inactive X chromosome.Andrew Keniry, Linden J. Gearing, Natasha Jansz, Joy Liu, Aliaksei Z. Holik, Peter F. Hickey, Sarah A. Kinkel, Darcy L. Moore, Kelsey Breslin, Kelan Chen, Ruijie Liu, Catherine Phillips, Miha Pakusch, Christine Biben, Julie M. Sheridan, Benjamin T. Kile, Catherine Carmichael, Matthew E. Ritchie, Douglas J. Hilton and Marnie E. Blewit
Can Campylobacter coli induce Guillain-Barré syndrome?
Campylobacter jejuni enteritis is the most frequently identified infection preceding the Guillain-Barr\ue9 syndrome (GBS) and neural damage is thought to be induced through molecular mimicry between C. jejuni lipo-oligosaccharide (LOS) and human gangliosides. It has been questioned whether or not other Campylobacter species, including C. curvus, C. upsaliensis and C. coli, could be similarly involved. This is relevant because it would imply that bacterial factors considered important in the aetiology of GBS crossed species barriers. Two prior reports have appeared where C. coli was putatively associated with a case of GBS.Peer reviewed: YesNRC publication: Ye
Antimicrobial susceptibility profile of clinically relevant Bacteroides, Phocaeicola, Parabacteroides and Prevotella species, isolated by eight laboratories in the Netherlands
Objectives: Recently, reports on antimicrobial-resistant Bacteroides and Prevotella isolates have increased in the Netherlands. This urged the need for a surveillance study on the antimicrobial susceptibility profile of Bacteroides, Phocaeicola, Parabacteroides and Prevotella isolates consecutively isolated from human clinical specimens at eight different Dutch laboratories. Methods: Each laboratory collected 20–25 Bacteroides (including Phocaeicola and Parabacteroides) and 10–15 Prevotella isolates for 3 months. At the national reference laboratory, the MICs of amoxicillin, amoxicillin/clavulanic acid, piperacillin/tazobactam, meropenem, imipenem, metronidazole, clindamycin, tetracycline and moxifloxacin were determined using agar dilution. Isolates with a high MIC of metronidazole or a carbapenem, or harbouring cfiA, were subjected to WGS. Results: Bacteroides thetaiotaomicron/faecis isolates had the highest MIC 90 values, whereas Bacteroides fragilis had the lowest MIC 90 values for amoxicillin/clavulanic acid, piperacillin/tazobactam, meropenem, imipenem and moxifloxacin. The antimicrobial profiles of the different Prevotella species were similar, except for amoxicillin, for which the MIC 50 ranged from 0.125 to 16 mg/L for Prevotella bivia and Prevotella buccae, respectively. Three isolates with high metronidazole MICs were sequenced, of which one Bacteroides thetaiotaomicron isolate harboured a plasmid-located nimE gene and a Prevotella melaninogenica isolate harboured a nimA gene chromosomally. Five Bacteroides isolates harboured a cfiA gene and three had an IS element upstream, resulting in high MICs of carbapenems. The other two isolates harboured no IS element upstream of the cfiA gene and had low MICs of carbapenems. Conclusions: Variations in resistance between species were observed. To combat emerging resistance in anaerobes, monitoring resistance and conducting surveillance are essential.</p
Interlaboratory comparison of sample preparation methods, database expansions, and cutoff values for identification of yeasts by matrix-assisted laser desorption ionization-time of flight mass spectrometry using a yeast test panel
An interlaboratory study using matrix-assisted laser desorption ionization–time of flight mass spectrometry (MALDI-TOF MS) to determine the identification of clinically important yeasts (n35) was performed at 11 clinical centers, one company, and one reference center using the Bruker Daltonics MALDI Biotyper system. The optimal cutoff for the MALDI-TOF MS score was investigated using receiver operating characteristic (ROC) curve analyses. The percentages of correct identifications were compared for different sample preparation methods and different databases. Logistic regression analysis was performed to analyze the association between the number of spectra in the database and the percentage of strains that were correctly identified. A total of 5,460 MALDI-TOF MS results were obtained. Using all results, the area under the ROC curve was 0.95 (95% confidence interval [CI], 0.94 to 0.96). With a sensitivity of 0.84 and a specificity of 0.97, a cutoff value of 1.7 was considered optimal. The overall percentage of correct identifications (formic acid-ethanol extraction method, score>1.7) was 61.5% when the commercial Bruker Daltonics database (BDAL) was used, and it increased to 86.8% by using an extended BDAL supplemented with a Centraalbureau voor Schimmelcultures (CBS)-KNAW Fungal Biodiversity Centre in-house database (BDALCBS in-house). A greater number of main spectra (MSP) in the database was associated with a higher percentage of correct identifications (odds ratio [OR], 1.10; 95% CI, 1.05 to 1.15; P<0.01). The results from the direct transfer method ranged from 0% to 82.9% correct identifications, with the results of the top four centers ranging from 71.4% to 82.9% correct identifications. This study supports the use of a cutoff value of 1.7 for the identification of yeasts using MALDI-TOF MS. The inclusion of enough isolates of the same species in the database can enhance the proportion of correctly identified strains. Further optimization of the preparation methods, especially of the direct transfer method, may contribute to improved diagnosis of yeast-related infections
Scholars’ open debate paper on the World Health Organization ICD-11 gaming disorder proposal
Concerns about problematic gaming behaviors deserve our full attention. However, we claim that it is far from clear that these problems can or should be attributed to a new disorder. The empirical basis for a Gaming Disorder proposal, such as in the new ICD-11, suffers from fundamental issues. Our main concerns are the low quality of the research base, the fact that the current operationalization leans too heavily on substance use and gambling criteria, and the lack of consensus on symptomatology and assessment of problematic gaming. The act of formalizing this disorder, even as a proposal, has negative medical, scientific, public-health, societal, and human rights fallout that should be considered. Of particular concern are moral panics around the harm of video gaming. They might result in premature application of diagnosis in the medical community and the treatment of abundant false-positive cases, especially for children and adolescents. Second, research will be locked into a confirmatory approach, rather than an exploration of the boundaries of normal versus pathological. Third, the healthy majority of gamers will be affected negatively. We expect that the premature inclusion of Gaming Disorder as a diagnosis in ICD-11 will cause significant stigma to the millions of children who play video games as a part of a normal, healthy life. At this point, suggesting formal diagnoses and categories is premature: the ICD-11 proposal for Gaming Disorder should be removed to avoid a waste of public health resources as well as to avoid causing harm to healthy video gamers around the world
A weak scientific basis for gaming disorder: let us err on the side of caution
We greatly appreciate the care and thought that is evident in the 10 commentaries that discuss our debate paper, the
majority of which argued in favor of a formalized ICD-11 gaming disorder. We agree that there are some people
whose play of video games is related to life problems. We believe that understanding this population and the nature
and severity of the problems they experience should be a focus area for future research. However, moving from
research construct to formal disorder requires a much stronger evidence base than we currently have. The burden of
evidence and the clinical utility should be extremely high, because there is a genuine risk of abuse of diagnoses. We
provide suggestions about the level of evidence that might be required: transparent and preregistered studies, a better
demarcation of the subject area that includes a rationale for focusing on gaming particularly versus a more general
behavioral addictions concept, the exploration of non-addiction approaches, and the unbiased exploration of clinical
approaches that treat potentially underlying issues, such as depressive mood or social anxiety first. We acknowledge
there could be benefits to formalizing gaming disorder, many of which were highlighted by colleagues in their
commentaries, but we think they do not yet outweigh the wider societal and public health risks involved. Given the
gravity of diagnostic classification and its wider societal impact, we urge our colleagues at the WHO to err on the side
of caution for now and postpone the formalization
Calsequestrin as a risk factor in Graves’ hyperthyroidism and Graves’ ophthalmopathy patients
Background: The pathogenesis of Graves’ ophthalmopathy (GO), Graves’ hyperthyroidism (GH) and the mechanisms for its link to thyroid autoimmunity are poorly understood. Our research focuses on the role of the skeletal muscle calcium binding protein calsequestrin (CASQ1) in thyroid. We measured the concentration of the CASQ1 protein correlating levels with parameters of the eye signs, CASQ1 antibody levels and CASQ1 gene polymorphism rs3838284. Methods: CASQ1 protein was measured by quantitative Western Blotting. The protein concentrations were expressed as pmol/mg total protein by reference to CASQ1 standards. Results: Western blot analysis showed the presence of two forms of CASQ1 in the thyroid. The mean concentration of CASQ1 protein was significantly reduced in patients with Graves’ disease, compared to thyroid from control subjects with multi-nodular goitre or thyroid cancer. Although in patients with GO it was lower than that, compared with patients with GH this difference was not significant. Reduced CASQ1 in Graves’ thyroid correlated with the homozygous genotype of the rs3838284 CASQ1 polymorphism. Conclusions: Decreased CASQ1 in the thyroid of patients with Graves’ disease compared to thyroid from control subjects is not explained but may reflect consumption of the protein during an autoimmune reaction against CASQ1 in the thyroid
Asymptomatic bacteriuria may be considered a complication in women with diabetes
WSTĘP. Celem pracy jest ocena częstości występowania oraz czynników ryzyka bezobjawowej bakteriurii (ASB, asymptomatic bacteriuria) u kobiet bez cukrzycy i chorych na cukrzycę.
MATERIAŁ I METODY. Do badania włączono 636 kobiet chorych na cukrzycę (typu 1 i 2) w wieku 18–75 lat, które w tym czasie nie były w ciąży i nie występowały u nich zaburzenia układu moczowego, oraz 153 kobiety bez cukrzycy, które zgłosiły się do okulisty lub do lekarza innej specjalności w celu leczenia urazów (jako grupa kontrolna). Bezobjawową bakteriurę zdefiniowano jako obecność co najmniej 105 bakterii na ml jednego lub dwóch rodzajów tworzących kolonie, wyhodowanych z czystego, środkowego strumienia moczu osoby bez objawów zakażenia dróg moczowych (UTI, urinary tract infection).
WYNIKI. Bezobjawowa bakteriuria występowała u 26% kobiet chorych na cukrzycę i u 6% kobiet bez cukrzycy (p < 0,001). Częstość ASB u kobiet chorych na cukrzycę typu 1 wyniosła 21%. Czynniki ryzyka ASB w cukrzycy typu 1 to: dłuższy czas trwania choroby, neuropatia obwodowa i makroalbuminuria. U kobiet chorych na cukrzycę typu 2 ASB występowała w 29% przypadków. Czynniki ryzyka ASB w cukrzycy typu 2 to: wiek, makroalbuminuria, niższy wskaźnik BMI oraz przebyte w poprzednim roku zakażenie dróg moczowych. Nie stwierdzono związku między aktualnym poziomem HbA1c i obecnością ASB.
WNIOSKI. Częstość ASB jest większa u kobiet chorych na cukrzycę niż bez cukrzycy i schorzenie to można uznać za jedno z powikłań cukrzycy u kobiet.OBJECTIVE. To study the prevalence of and risk factors
for asymptomatic bacteriuria (ASB) in women with and
without diabetes.
RESEARCH DESIGN AND METHODS. A total of 636 nonpregnant
women with diabetes (type 1 and type 2)
who were 18–75 years of age and had no abnormalities
of the urinary tract, and 153 women without diabetes
who were visiting the eye and trauma outpatient clinic
(control subjects) were included. We defined ASB as
the presence of at least 105 colony-forming units/ml of
1 or 2 bacterial species in a culture of clean-voided
midstream urine from an individual without symptoms
of a urinary tract infection (UTI).
RESULTS. The prevalence of ASB was 26% in the diabetic
women and 6% in the control subjects (P < 0.001).
The prevalence of ASB in women with type 1 diabetes
was 21%. Risk factors for ASB in type 1 diabetic women
included a longer duration of diabetes, peripheral neuropathy,
and macroalbuminuria. The prevalence of ASB
was 29% in women with type 2 diabetes. Risk factors
for ASB in type 2 diabetic women included age, macroalbuminuria,
a lower BMI, and a UTI during the previous
year. No association was evident between current
HbA1c level and the presence of ASB.
CONCLUSIONS. The prevalence of ASB is increased in
women with diabetes and might be added to the list of
diabetic complications in these women
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