34 research outputs found
CD1d expression demarcates CDX4+ hemogenic mesoderm with definitive hematopoietic potential
To achieve efficient, reproducible differentiation of human pluripotent stem cells (hPSCs) towards specific hematopoietic cell-types, a comprehensive understanding of the necessary cell signaling and developmental trajectories involved is required. Previous studies have identified the mesodermal progenitors of extra-embryonic-like and intra-embryonic-like hemogenic endothelium (HE), via stage-specific WNT and ACTIVIN/NODAL, with GYPA/GYPB (CD235a/b) expression serving as a positive selection marker for mesoderm harboring exclusively extra-embryonic-like hemogenic potential. However, a positive mesodermal cell-surface marker with exclusively intra-embryonic-like hemogenic potential has not been identified. Recently, we reported that early mesodermal expression of CDX4 critically regulates definitive HE specification, suggesting that CDX4 may act in a cell-autonomous manner during hematopoietic development. To identify CDX4+ mesoderm, we performed single cell (sc)RNAseq on hPSC-derived mesodermal cultures, revealing CDX
Spondylarthropathies (including psoriatic arthritis): 244. Validity of Colour Doppler and Spectral Doppler Ultrasound of Sacroilicac Joints Againts Physical Examination as Gold Standard
Background: Sacroiliac joints (SJ) involvement is a distinctive and charasteristic feature of Spondyloarthritis (SpA) and x-ray is the test routinely used to make a diagnosis. However, x-ray reveals late structural damage but cannot detect active inflammation. The objective of this study was to assess the validity of Doppler ultrasound in SJ. Methods: Prospective blinded and controlled study of SJ, in which three populations were compared. We studied 106 consecutive cases, who were divided into three groups: a) 53 patients diagnosed with SpA who had inflammatory lumbar and gluteal pain assessed by a rheumatologist; b) 26 patients diagnosed with SpA who didn't have SJ tenderness and had normal physical examination; c) control group of 27 subjects (healthy subjetcs or with mechanical lumbar pain). All patients included that were diagnosed with SpA met almost the European Spondyloarthropathy Study Group (ESSG) classification criteria. Physical examination of the SJ included: sacral sulcus tenderness, iliac gapping, iliac compression, midline sacral thrust test, Gaenslen's test, and Patrick s test were used as gold standard. Both SJ were examined with Doppler ultrasound (General Electric Logiq 9, Wauwatosa WI, USA) fitted with a 9-14 Mhz lineal probe. The ultrasonographer was blinded to clinical data. Doppler in SJ was assessed as positive when both Doppler colour and resistance index (RI)â<â0.75 within the SJ area were present. Statistical analysis was performed estimating sensitivity and specificity against gold standard. The Kappa correlation coefficient was used for reliability study. Results: 106 cases (53 female, 55 male; mean age 36 10 years) were studied. There were no statistical differences between groups related to age or sex. Physical examination of SJ was positive in 38 patients (59 sacroiliac joints). US detected Doppler signal within SJ in 37 patients (58 SJ): 33 of them were symptomatic SpA (52 SJ), one of them were asymptomatic SpA (1 SJ) and one was a healthy control (1 SJ). The accuracy of US when compared to clinical data as gold standard at subject level in the overall group was: sensitivity of 68.6% and specificity of 85.7%, positive predictive value of 70.5% and negative predictive value of 84.5%. A positive likelihood ratio of 4.8, a negative likelihood ratio of 0.36 and a kappa coefficient of 0.55 were achieved. Conclusions: Doppler US of SJ seems to be a valid method to detect active SJ inflammation. Disclosure statement: The authors have declared no conflicts of interes
Early Ultrasound Surveillance of Newly-Created Hemodialysis Arteriovenous Fistula
Introduction:
We assess if ultrasound surveillance of newly-created arteriovenous fistulas (AVFs) can predict nonmaturation sufficiently reliably to justify randomised controlled trial (RCT) evaluation of ultrasounddirected salvage intervention.
Methods:
Consenting adults underwent blinded fortnightly ultrasound scanning of their AVF after creation,
with scan characteristics that predicted AVF non-maturation identified by logistic regression
modelling.
Results:
Of 333 AVFs created, 65.8% matured by 10 weeks. Serial scanning revealed that maturation occurred
rapidly, whereas consistently lower fistula flow rates and venous diameters were observed in those
that did not mature. Wrist and elbow AVF non-maturation could be optimally modelled from the
week four ultrasound parameters alone, but with only moderate positive predictive values (wrist,
60.6% (95% CI 43.9 â 77.3); elbow, 66.7% (48.9 - 84.4)). Moreover, 40 (70.2%) of the 57 AVFs that
thrombosed by week 10 had already failed by the week 4 scan, thus limiting the potential of salvage
procedures initiated by that scanâs findings to alter overall maturation rates.
Modelling of the early ultrasound characteristics could also predict primary patency failure at 6
months, but that model performed poorly at predicting assisted primary failure (those AVFs that
failed despite a salvage attempt), partly because patency of at-risk AVFs was maintained by
successful salvage performed without recourse to the early scan data.
Conclusions:
Early ultrasound surveillance may predict fistula maturation, but is likely, at best, to result in only
very modest improvements in fistula patency. Power calculations suggest that an impractically large
number of participants (>1700) would be required for formal RCT evaluation
Early ultrasound surveillance of newly-created haemodialysis arteriovenous fistula
IntroductionWe assess if ultrasound surveillance of newly-created arteriovenous fistulas (AVFs) can predict nonmaturation sufficiently reliably to justify randomized controlled trial (RCT) evaluation of ultrasound-directed salvage intervention.MethodsConsenting adults underwent blinded fortnightly ultrasound scanning of their AVF after creation, with scan characteristics that predicted AVF nonmaturation identified by logistic regression modeling.ResultsOf 333 AVFs created, 65.8% matured by 10 weeks. Serial scanning revealed that maturation occurred rapidly, whereas consistently lower fistula flow rates and venous diameters were observed in those that did not mature. Wrist and elbow AVF nonmaturation could be optimally modeled from week 4 ultrasound parameters alone, but with only moderate positive predictive values (PPVs) (wrist, 60.6% [95% confidence interval, CI: 43.9â77.3]; elbow, 66.7% [48.9â84.4]). Moreover, 40 (70.2%) of the 57 AVFs that thrombosed by week 10 had already failed by the week 4 scan, thus limiting the potential of salvage procedures initiated by that scanâs findings to alter overall maturation rates. Modeling of the early ultrasound characteristics could also predict primary patency failure at 6 months; however, that model performed poorly at predicting assisted primary failure (those AVFs that failed despite a salvage attempt), partly because patency of at-risk AVFs was maintained by successful salvage performed without recourse to the early scan data.ConclusionEarly ultrasound surveillance may predict fistula maturation, but is likely, at best, to result in only very modest improvements in fistula patency. Power calculations suggest that an impractically large number of participants (>1700) would be required for formal RCT evaluation
A Multicenter, Randomized, PlaceboâControlled Trial of Atorvastatin for the Primary Prevention of Cardiovascular Events in Patients With Rheumatoid Arthritis
Objective:
Rheumatoid arthritis (RA) is associated with increased cardiovascular event (CVE) risk. The impact of statins in RA is not established. We assessed whether atorvastatin is superior to placebo for the primary prevention of CVEs in RA patients.
Methods:
A randomized, doubleâblind, placeboâcontrolled trial was designed to detect a 32% CVE risk reduction based on an estimated 1.6% per annum event rate with 80% power at P 50 years or with a disease duration of >10 years who did not have clinical atherosclerosis, diabetes, or myopathy received atorvastatin 40 mg daily or matching placebo. The primary end point was a composite of cardiovascular death, myocardial infarction, stroke, transient ischemic attack, or any arterial revascularization. Secondary and tertiary end points included plasma lipids and safety.
Results:
A total of 3,002 patients (mean age 61 years; 74% female) were followed up for a median of 2.51 years (interquartile range [IQR] 1.90, 3.49 years) (7,827 patientâyears). The study was terminated early due to a lower than expected event rate (0.70% per annum). Of the 1,504 patients receiving atorvastatin, 24 (1.6%) experienced a primary end point, compared with 36 (2.4%) of the 1,498 receiving placebo (hazard ratio [HR] 0.66 [95% confidence interval (95% CI) 0.39, 1.11]; P = 0.115 and adjusted HR 0.60 [95% CI 0.32, 1.15]; P = 0.127). At trial end, patients receiving atorvastatin had a mean ± SD lowâdensity lipoprotein (LDL) cholesterol level 0.77 ± 0.04 mmoles/liter lower than those receiving placebo (P < 0.0001). Câreactive protein level was also significantly lower in the atorvastatin group than the placebo group (median 2.59 mg/liter [IQR 0.94, 6.08] versus 3.60 mg/liter [IQR 1.47, 7.49]; P < 0.0001). CVE risk reduction per mmole/liter reduction in LDL cholesterol was 42% (95% CI â14%, 70%). The rates of adverse events in the atorvastatin group (n = 298 [19.8%]) and placebo group (n = 292 [19.5%]) were similar.
Conclusion:
Atorvastatin 40 mg daily is safe and results in a significantly greater reduction of LDL cholesterol level than placebo in patients with RA. The 34% CVE risk reduction is consistent with the Cholesterol Treatment Trialistsâ Collaboration metaâanalysis of statin effects in other populations
A community based mental health response to a multiple shooting
It has become common practice to develop community based mental health interventions following disasters of various kinds. This paper reports on the mental health response to a multiple fatal shooting mat occurred in a city office block in Melbourne, Australia. Emphasis is placed on the adaptation of general principles to the specific needs of the disaster affected community. A rationale for the approach is presented, and the importance of community participation in design and implementation of the program is discussed. The paper describes the major strategies utilised and provides evaluative comment on the program
Genetic variation in Dip5, an amino acid permease, and Pdr5, a multiple drug transporter, regulates glyphosate resistance in S. cerevisiae
S. cerevisiae from different environments are subject to a wide range of selective pressures, whether intentional or by happenstance. Chemicals classified by their application, such as herbicides, fungicides and antibiotics, can affect non-target organisms. First marketed as RoundUpTM, glyphosate is the most widely used herbicide. In plants, glyphosate inhibits EPSPS, of the shikimate pathway, which is present in many organisms but lacking in mam- mals. The shikimate pathway produces chorismate which is the precursor to all the aromatic amino acids, para-aminobenzoic acid, and Coenzyme Q10. Crops engineered to be resis- tant to glyphosate contain a homolog of EPSPS that is not bound by glyphosate. Here, we show that S. cerevisiae has a wide-range of glyphosate resistance. Sequence comparison between the target proteins, i.e., the plant EPSPS and the yeast orthologous protein Aro1, predicted that yeast would be resistant to glyphosate. However, the growth variation seen in the subset of yeast tested was not due to polymorphisms within Aro1, instead, it was caused by genetic variation in an ABC multiple drug transporter, Pdr5, and an amino acid permease, Dip5. Using genetic variation as a probe into glyphosate response, we uncovered mecha- nisms that contribute to the transportation of glyphosate in and out of the cell. Taking advan- tage of the natural genetic variation within yeast and measuring growth under different conditions that would change the use of the shikimate pathway, we uncovered a general transport mechanism of glyphosate into eukaryotic cells
Genetic variation in Dip5, an amino acid permease, and Pdr5, a multiple drug transporter, regulates glyphosate resistance in S. cerevisiae
S. cerevisiae from different environments are subject to a wide range of selective pressures, whether intentional or by happenstance. Chemicals classified by their application, such as herbicides, fungicides and antibiotics, can affect non-target organisms. First marketed as RoundUpTM, glyphosate is the most widely used herbicide. In plants, glyphosate inhibits EPSPS, of the shikimate pathway, which is present in many organisms but lacking in mam- mals. The shikimate pathway produces chorismate which is the precursor to all the aromatic amino acids, para-aminobenzoic acid, and Coenzyme Q10. Crops engineered to be resis- tant to glyphosate contain a homolog of EPSPS that is not bound by glyphosate. Here, we show that S. cerevisiae has a wide-range of glyphosate resistance. Sequence comparison between the target proteins, i.e., the plant EPSPS and the yeast orthologous protein Aro1, predicted that yeast would be resistant to glyphosate. However, the growth variation seen in the subset of yeast tested was not due to polymorphisms within Aro1, instead, it was caused by genetic variation in an ABC multiple drug transporter, Pdr5, and an amino acid permease, Dip5. Using genetic variation as a probe into glyphosate response, we uncovered mecha- nisms that contribute to the transportation of glyphosate in and out of the cell. Taking advan- tage of the natural genetic variation within yeast and measuring growth under different conditions that would change the use of the shikimate pathway, we uncovered a general transport mechanism of glyphosate into eukaryotic cells
Pain Mechanisms in Osteoarthritis: Understanding the Role of Central Pain and Current Approaches to Its Treatment: Figure 1.
In this literature review, the mechanisms underlying pain associated with osteoarthritis (OA) are discussed, along with evidence for the efficacy of medications thought to act centrally to relieve OA pain. We survey the cascade of events from inflammation to activation of nociceptive and neuropathic pathways, to the development and maintenance of central and peripheral sensitization. Preclinical and clinical evidence for the sensitization hypothesis is discussed, along with recently identified genetic variations that may increase sensitivity to pain in patients with OA. Evidence is presented for the efficacy of centrally acting analgesics for OA pain (opioids, antiepileptics, tricyclic antidepressants, and serotonin/norepinephrine receptor inhibitors)