71 research outputs found
Screening of a HUVEC cDNA library with transplant-associated coronary artery disease sera identifies RPL7 as a candidate autoantigen associated with this disease.
A HUVEC cDNA library was screened with sera from two patients who had developed transplant-associated coronary artery disease (TxCAD) following cardiac transplantation. A total of six positive clones were isolated from a primary screen of 40 000 genes. Subsequent DNA sequence analysis identified these to be lysyl tRNA synthetase, ribosomal protein L7, ribosomal protein L9, beta transducin and TANK. Another gene whose product could not be identified showed homology to a human cDNA clone (DKFZp566M063) derived from fetal kidney. Full-length constructs of selected genes were expressed as his-tag recombinant fusion proteins and used to screen a wider patient base by ELISA to determine prevalence and association with TxCAD. Of these ribosomal protein L7 showed the highest prevalence (55.6%) with TxCAD sera compared to 10% non-CAD
Valve interstitial cells induce donor-specific T-cell anergy
AbstractObjectives: Valve allografts produce an immune response, which can influence their performance. The exact role of the interaction between recipient T cells and the different cellular components of the donor valve in stimulating an immune response is not known. Therefore the T-cell response to valve endothelial and interstitial cells was investigated in vitro. Methods: Valve endothelial and interstitial cells were characterized for cell-surface molecules before and after interferon Îł treatment by means of a panel of specific monoclonal antibodies and flow cytometry. The proliferative response of highly purified T lymphocytes was used to assess the immunogenicity of cultured valve endothelial and interstitial cells. This was further investigated by using a 2-step tolerance-induction protocol. Results: Valve endothelial and interstitial cells express similar levels of human leukocyte antigens and adhesion and costimulatory molecules, which are either induced or upregulated after interferon Îł treatment. T-cell responses to endothelial cells were detected after interferon Îł treatment, but responses to interferon Îłâtreated interstitial cells were not detected. This lack of response resulted in the induction of T-cell anergy, which was reversed by the presence of the costimulatory molecule B7-1. Conclusions: Although valve endothelial and interstitial cells express a similar range of cell-surface molecules, it is only the endothelial cells that are immunogenic. In addition, we have shown that these 2 cell types interact in a donorspecific manner to orchestrate the immune response and therefore may have clinical relevance in the allogeneic response of the heart valve recipients.J Thorac Cardiovasc Surg 2001;122:129-3
Fostering support for non-democratic rule? Controlled political liberalization and popular support for non-democratic regimes
When the Cold War ended, many non-democratic regimes across the globe embarked on a course of controlled political liberalization, hoping to stabilize their autocratic rule by mitigating popular demands for democratization and increasing regime legitimacy. But does this strategy actually work? This article uses multi-level analyses to examine how the degree of political liberalization affects regime support in non-democratic political systems and to ascertain which mechanisms underlie this effect. Drawing on aggregate measures of political liberalization and comparative survey data from four regional survey projects and 31 non-democracies, the study's results indicate that the degree of liberalization has no decisively positive effect on regime support, suggesting controlled political liberalization might not be an effective legitimizing strategy after all.Nach Ende des Kalten Krieges haben viele nicht-demokratische Regime weltweit einen Kurs der begrenzten politischen Ăffnung eingeschlagen, um öffentliche Forderungen nach Demokratisierung zu entschĂ€rfen und auf diese Weise die LegitimitĂ€t ihrer autokratischen Herrschaft zu erhöhen. Doch ist diese Strategie tatsĂ€chlich effektiv? Der Beitrag verwendet Mehrebenenanalysen, um zu untersuchen wie der Grad an politischer Ăffnung die RegimerunterstĂŒtzung in nicht-demokratischen politischen Systemen beeinflusst. Auf Basis von AggregatmaĂen zur politischen Ăffnung und Individualdaten aus vier regionalen Umfrageprojekten und 31 Autokratien kann kein klarer positiver Effekt des Grads der politischen Ăffnung auf die RegimeunterstĂŒtzung nachgewiesen werden, was eine begrenzte politische Ăffnung als wenig effektive Legitimationsstrategie erscheinen lĂ€sst
Genetic or pharmaceutical blockade of phosphoinositide 3-kinase p110ÎŽ prevents chronic rejection of heart allografts.
Chronic rejection is the major cause of long-term heart allograft failure, characterized by tissue infiltration by recipient T cells with indirect allospecificity. Phosphoinositol-3-kinase p110ÎŽ is a key mediator of T cell receptor signaling, regulating both T cell activation and migration of primed T cells to non-lymphoid antigen-rich tissue. We investigated the effect of genetic or pharmacologic inactivation of PI3K p110ÎŽ on the development of chronic allograft rejection in a murine model in which HY-mismatched male hearts were transplanted into female recipients. We show that suppression of p110ÎŽ activity significantly attenuates the development of chronic rejection of heart grafts in the absence of any additional immunosuppressive treatment by impairing the localization of antigen-specific T cells to the grafts, while not inducing specific T cell tolerance. p110ÎŽ pharmacologic inactivation is effective when initiated after transplantation. Targeting p110ÎŽ activity might be a viable strategy for the treatment of heart chronic rejection in humans
Dermatitis herpetiformis: pathophysiology, clinical presentation, diagnosis and treatment
Mortality from gastrointestinal congenital anomalies at 264 hospitals in 74 low-income, middle-income, and high-income countries: a multicentre, international, prospective cohort study
Summary
Background Congenital anomalies are the fifth leading cause of mortality in children younger than 5 years globally.
Many gastrointestinal congenital anomalies are fatal without timely access to neonatal surgical care, but few studies
have been done on these conditions in low-income and middle-income countries (LMICs). We compared outcomes of
the seven most common gastrointestinal congenital anomalies in low-income, middle-income, and high-income
countries globally, and identified factors associated with mortality.
Methods We did a multicentre, international prospective cohort study of patients younger than 16 years, presenting to
hospital for the first time with oesophageal atresia, congenital diaphragmatic hernia, intestinal atresia, gastroschisis,
exomphalos, anorectal malformation, and Hirschsprungâs disease. Recruitment was of consecutive patients for a
minimum of 1 month between October, 2018, and April, 2019. We collected data on patient demographics, clinical
status, interventions, and outcomes using the REDCap platform. Patients were followed up for 30 days after primary
intervention, or 30 days after admission if they did not receive an intervention. The primary outcome was all-cause,
in-hospital mortality for all conditions combined and each condition individually, stratified by country income status.
We did a complete case analysis.
Findings We included 3849 patients with 3975 study conditions (560 with oesophageal atresia, 448 with congenital
diaphragmatic hernia, 681 with intestinal atresia, 453 with gastroschisis, 325 with exomphalos, 991 with anorectal
malformation, and 517 with Hirschsprungâs disease) from 264 hospitals (89 in high-income countries, 166 in middleincome
countries, and nine in low-income countries) in 74 countries. Of the 3849 patients, 2231 (58·0%) were male.
Median gestational age at birth was 38 weeks (IQR 36â39) and median bodyweight at presentation was 2·8 kg (2·3â3·3).
Mortality among all patients was 37 (39·8%) of 93 in low-income countries, 583 (20·4%) of 2860 in middle-income
countries, and 50 (5·6%) of 896 in high-income countries (p<0·0001 between all country income groups).
Gastroschisis had the greatest difference in mortality between country income strata (nine [90·0%] of ten in lowincome
countries, 97 [31·9%] of 304 in middle-income countries, and two [1·4%] of 139 in high-income countries;
pâ€0·0001 between all country income groups). Factors significantly associated with higher mortality for all patients
combined included country income status (low-income vs high-income countries, risk ratio 2·78 [95% CI 1·88â4·11],
p<0·0001; middle-income vs high-income countries, 2·11 [1·59â2·79], p<0·0001), sepsis at presentation (1·20
[1·04â1·40], p=0·016), higher American Society of Anesthesiologists (ASA) score at primary intervention
(ASA 4â5 vs ASA 1â2, 1·82 [1·40â2·35], p<0·0001; ASA 3 vs ASA 1â2, 1·58, [1·30â1·92], p<0·0001]), surgical safety
checklist not used (1·39 [1·02â1·90], p=0·035), and ventilation or parenteral nutrition unavailable when needed
(ventilation 1·96, [1·41â2·71], p=0·0001; parenteral nutrition 1·35, [1·05â1·74], p=0·018). Administration of
parenteral nutrition (0·61, [0·47â0·79], p=0·0002) and use of a peripherally inserted central catheter (0·65
[0·50â0·86], p=0·0024) or percutaneous central line (0·69 [0·48â1·00], p=0·049) were associated with lower mortality.
Interpretation Unacceptable differences in mortality exist for gastrointestinal congenital anomalies between lowincome,
middle-income, and high-income countries. Improving access to quality neonatal surgical care in LMICs will
be vital to achieve Sustainable Development Goal 3.2 of ending preventable deaths in neonates and children younger
than 5 years by 2030
Effect of angiotensin-converting enzyme inhibitor and angiotensin receptor blocker initiation on organ support-free days in patients hospitalized with COVID-19
IMPORTANCE Overactivation of the renin-angiotensin system (RAS) may contribute to poor clinical outcomes in patients with COVID-19.
Objective To determine whether angiotensin-converting enzyme (ACE) inhibitor or angiotensin receptor blocker (ARB) initiation improves outcomes in patients hospitalized for COVID-19.
DESIGN, SETTING, AND PARTICIPANTS In an ongoing, adaptive platform randomized clinical trial, 721 critically ill and 58 nonâcritically ill hospitalized adults were randomized to receive an RAS inhibitor or control between March 16, 2021, and February 25, 2022, at 69 sites in 7 countries (final follow-up on June 1, 2022).
INTERVENTIONS Patients were randomized to receive open-label initiation of an ACE inhibitor (nâ=â257), ARB (nâ=â248), ARB in combination with DMX-200 (a chemokine receptor-2 inhibitor; nâ=â10), or no RAS inhibitor (control; nâ=â264) for up to 10 days.
MAIN OUTCOMES AND MEASURES The primary outcome was organ supportâfree days, a composite of hospital survival and days alive without cardiovascular or respiratory organ support through 21 days. The primary analysis was a bayesian cumulative logistic model. Odds ratios (ORs) greater than 1 represent improved outcomes.
RESULTS On February 25, 2022, enrollment was discontinued due to safety concerns. Among 679 critically ill patients with available primary outcome data, the median age was 56 years and 239 participants (35.2%) were women. Median (IQR) organ supportâfree days among critically ill patients was 10 (â1 to 16) in the ACE inhibitor group (nâ=â231), 8 (â1 to 17) in the ARB group (nâ=â217), and 12 (0 to 17) in the control group (nâ=â231) (median adjusted odds ratios of 0.77 [95% bayesian credible interval, 0.58-1.06] for improvement for ACE inhibitor and 0.76 [95% credible interval, 0.56-1.05] for ARB compared with control). The posterior probabilities that ACE inhibitors and ARBs worsened organ supportâfree days compared with control were 94.9% and 95.4%, respectively. Hospital survival occurred in 166 of 231 critically ill participants (71.9%) in the ACE inhibitor group, 152 of 217 (70.0%) in the ARB group, and 182 of 231 (78.8%) in the control group (posterior probabilities that ACE inhibitor and ARB worsened hospital survival compared with control were 95.3% and 98.1%, respectively).
CONCLUSIONS AND RELEVANCE In this trial, among critically ill adults with COVID-19, initiation of an ACE inhibitor or ARB did not improve, and likely worsened, clinical outcomes.
TRIAL REGISTRATION ClinicalTrials.gov Identifier: NCT0273570
IFN-Îł Reverses the Stop Signal Allowing Migration of Antigen-Specific T Cells into Inflammatory Sites
Humoral immune response to human aortic valve homografts
The humoral response to homograft valves in humans is largely unknown. The anti-human lymphocyte antigen (HLA) antibody production, specificity, and immunoglobulin class were examined sequentially in 73 patients undergoing aortic valve replacement. In addition, the long-term production of antibodies was examined in a cross-sectional study of 160 patients at periods varying from 1 to 15 years postoperatively. Human lymphocyte antigen antibodies were produced in 17 of 30 antibioticsterilized homografts (56%) and in 15 of 15 âhomovitalâ homograft recipients, compared with 6 of the 28 control xenograft recipients (21%) (p < 0.001). The HLA antibodies were immunoglobulin G in all 15 homovital homografts, in 11 of 17 antibiotic-sterilized homografts, and in four of the six xenograft cases. Human lymphocyte antigen specificities could be assigned to the antibodies in 21 cases. In 10 of 11 cases in which donor HLA typing data were available, the antibodies detected were directed against donor HLA class I antigens. Of six possible determinants of HLA antibody production, the type of homograft valve implanted (homovital or antibiotic sterilized) correlated with antibody formation. In the crosssectional study, 66 of the 85 homovital homograft recipients tested for HLA antibodies after 1 year were found to have antibodies, compared with 29 of 75 antibioticsterilized homograft recipients (p = 0.00003). We conclude that homografts appear to stimulate a strong donor HLA-specific antibody response, particularly of the immunoglobulin G class. This is most common in homovital valve recipients. These antibodies can persist for 15 years after operation. The clinical significance of this response requires further investigation
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