Successful catheter cryoablation of Hisian ectopy using 2 new diagnostic criteria based on unipolar and bipolar recordings of the His electrogram

We describe the case of a 61-year-old woman who underwent successful catheter cryoablation of a symptomatic Hisian ectopy. Diagnosis was based on features of the HV interval assessed from a bipolar recording during mapping. The location of the arrhythmic focus was identified using simultaneous unipolar and bipolar recordings of the His electrogram. This case report highlights the use of 2 new criteria for the diagnosis and mapping of Hisian ectopy, and the successful use of cryothermia for the ablation of extrasystoles arising from the His bundle.     

Exposure to second-hand smoke and reproductive outcomes depending on maternal asthma

Tobacco consumption and exposure to second-hand smoke (SHS) are associated with reduced birth weight. One issue that has not been clarified previously is that of the potential higher risk of this outcome in mothers with asthma. We assessed the role of prenatal maternal tobacco use and SHS on reproductive outcomes and assessed the interaction with maternal history of asthma. Data was collected from the INMA study, a maternal birth cohort selected from the general population established in Spain in 2002. We measured cotinine at the 32nd week of pregnancy in 2,219 females. Diagnosed maternal asthma was self-reported during pregnancy. 35% of mothers reported not being exposed to smoking or SHS during pregnancy. Active smoking (i.e. self-reported or cotinine >50 ng·mL(-1)) was related to a 134 g decrease in birth weight and a relative risk of 1.8 for small for gestational age and fetal growth restriction. These results were not modified by maternal asthma. Maternal asthma had a similar frequency in all exposure groups. Non SHS-exposed females had the lowest prevalence of asthma. SHS (i.e. cotinine 20-50 ng·mL(-1)) decreased birth weight by 32 g among those without maternal asthma, but these differences were not statistically significant (95% CI -88.76-24.76). Maternal asthma did not promote these effects. Maternal history of asthma did not modify the effects of smoking on reproductive outcomes in a cohort sampled from the general population.     

Circulating endothelial cells and their progenitors in systemic lupus erythematosus and early rheumatoid arthritis patients

Objective. The aim of this study was to investigate the endothelial progenitor cell population in SLE and early RA patients and its potential relationships with disease features and cytokine serum levels. Methods. Endothelial progenitor cells (EPCs), mature EPCs (mEPCs) and endothelial cells (ECs) were measured in peripheral blood samples from 83 SLE and 85 early RA patients and 39 healthy controls by flow cytometry on the basis of CD34, VEGF receptor 2 and CD133 expression. Serum levels of IL-1β, IL-6, IL-8, IL-17, VEGF-A, IFN-α, TGF-β and GM-CSF were quantified by immunoassays. Clinical and immunological data were obtained by reviewing clinical histories. Results. Circulating EPCs were increased in SLE but not in early RA patients associated with an enhanced CD34(+) bone marrow-progenitor cell release but unrelated to disease features. The amount of mEPCs, however, was significantly higher in SLE patients presenting anti-SSA/SSB antibodies and/or malar rash, whereas the presence of specific autoantibodies was associated with EC counts in early RA and SLE patients. As expected, most cytokines tested were altered in both diseases but, interestingly, IFN-α levels, and to a lesser extent IL-6 and IL-1β, were associated with CD133 loss and increased mEPC number, whereas VEGF and TGF-β seem to exert an opposite effect. Conclusion. Our results show that high IFN-α levels and/or the presence of disease-specific antibodies may identify a group of SLE patients with increased mEPC and EC counts, and consequently probably defective endothelial repair, thus supporting their use as surrogate biomarkers of endothelial damage and high cardiovascular risk.     

Potential mechanisms for increased HIV-1 transmission across the endocervical epithelium during C. trachomatis infection

Among the now pandemic sexually transmitted infections (STIs), Chlamydia trachomatis (C. trachomatis) is the predominant bacterial pathogen and human immunodeficiency virus type 1 (HIV-1) is the most lethal of the viral pathogens. The female genital tract is the primary site for heterosexual transmission of both C. trachomatis and HIV-1. Infection with C. trachomatis, and with a variety of other STIs, increases the risk for transmission of HIV-1, although the mechanisms for this finding remain unclear. We have used in vitro modeling to assess the mechanisms by which infection with genital C. trachomatis serovars might increase the transmission of HIV-1 across the female genital tract. C. trachomatis infection of an immortalized endocervical epithelial cell line (A2EN) increases the cell surface expression of the HIV-1 alternative primary receptor, galactosyl ceramide (GalCer), and of the HIV-1 co-receptors, CXCR4 and CCR5. C. trachomatis infection also increases the binding of HIV-1 to A2EN cells, and, subsequently, increases levels of virus in co-cultures of HIV-exposed A2EN and susceptible MT4-R5 T cells. Finally, in vivo endocervical cell sampling reveals a dramatic increase in the number of CD4+, CXCR4 and/or CCR5 positive T cell targets in the endocervix of C. trachomatis positive women when compared to those who are C. trachomatis negative. This combination of in vitro and in vivo results suggests several mechanisms for increased transmission of HIV-1 across the endocervices of C. trachomatis-infected women.     

High-Efficiency Postdilution Online Hemodiafiltration Reduces All-Cause Mortality in Hemodialysis Patients

Retrospective studies suggest that online hemodiafiltration (OL-HDF) may reduce the risk of mortality compared with standard hemodialysis in patients with ESRD. We conducted a multicenter, open-label, randomized controlled trial in which we assigned 906 chronic hemodialysis patients either to continue hemodialysis (n=450) or to switch to high-efficiency postdilution OL-HDF (n=456). The primary outcome was all-cause mortality, and secondary outcomes included cardiovascular mortality, all-cause hospitalization, treatment tolerability, and laboratory data. Compared with patients who continued on hemodialysis, those assigned to OL-HDF had a 30% lower risk of all-cause mortality (hazard ratio [HR], 0.70; 95% confidence interval [95% CI], 0.53–0.92; P=0.01), a 33% lower risk of cardiovascular mortality (HR, 0.67; 95% CI, 0.44–1.02; P=0.06), and a 55% lower risk of infection-related mortality (HR, 0.45; 95% CI, 0.21–0.96; P=0.03). The estimated number needed to treat suggested that switching eight patients from hemodialysis to OL-HDF may prevent one annual death. The incidence rates of dialysis sessions complicated by hypotension and of all-cause hospitalization were lower in patients assigned to OL-HDF. In conclusion, high-efficiency postdilution OL-HDF reduces all-cause mortality compared with conventional hemodialysis.In the last decades, renal replacement therapy with hemodialysis has become a standard of care for patients with ESRD. Despite continuous improvement, annual mortality among these patients ranges between 15% and 25%.^1,2 Hemodialysis techniques are based on the ability of molecules to diffuse across a semipermeable membrane, which allows adequate clearance of low molecular weight particles. To increase the clearance of middle-to-large molecules, synthetic membranes with high water permeability (high-flux membranes) were introduced years ago. The anticipated benefit of high-flux over low-flux hemodialysis on patient survival was not confirmed in the Hemodialysis (HEMO) study.³ However, the Membrane Permeability Outcome (MPO) study,⁴ as well as a post hoc analysis in diabetic patients, showed that high-flux hemodialysis improved long-term survival in patients with hypoalbuminemia.Clearance of middle-to-large molecules can be increased by combining diffusive and convective transport through hemodiafiltration. The introduction of online hemodiafiltration (OL-HDF) using ultrapure dialysate as the source of the replacement fluid has allowed the convective volume to be increased and has reduced the cost of the procedure.⁵ Randomized studies with limited sample sizes and nonrandomized studies have shown that OL-HDF improves hemodynamic stability and response to erythropoietic-stimulating agents (ESAs) and reduces the incidence of hemodialysis-associated amyloidosis and chronic inflammation.^6–11 The effect of OL-HDF on patient survival is derived from noncontrolled studies. The European Dialysis Outcomes and Practice Pattern Study was associated with a mortality risk reduction of 35% in patients treated with high-efficiency hemodiafiltration compared with those treated with conventional hemodialysis.¹² These results were confirmed in other noncontrolled studies conducted in several European countries,^13–15 although two recent, randomized studies failed to show differences in patient survival^16,17In 2007, the Catalonian Health Authorities approved a specific additional reimbursement for OL-HDF to dialysis care providers and the Catalonian Society of Nephrology promoted this randomized study (On-Line Hemodiafiltration Survival Study, or Estudio de Supervivencia de Hemodiafiltración On-Line [ESHOL]) to compare the effect of OL-HDF over hemodialysis on patient survival.¹⁸     

Abnormal functioning of the semantic network in schizophrenia patients with thought disorganization. An exemplar production task

Numerous studies have indicated that thought disorganization in schizophrenia is associated with an enhanced semantic priming effect. This suggests abnormal functioning of the semantic network in these patients, with disinhibited spreading of semantic activation. We investigated whether thought disorganization is also associated with atypical responses in the production of semantic category exemplars. An exemplar production task was administered to 43 patients with schizophrenia and 24 healthy controls. The names of 16 semantic categories were provided, and the participants were requested to produce an exemplar for each category. The typicality of the response was rated according to norms. Higher ratings of thought disorganization were associated with the production of more atypical exemplars. In addition, the patients with high thought disorganization scores were significantly more atypical in their responses than were the healthy controls. In contrast, the patients with low thought disorganization scores were equivalent to the healthy controls. Higher ratings of affective flattening were associated with the production of less atypical exemplars. The results corroborate, within a different paradigm than semantic priming, the theory that thought disorganization is associated with faster and more distant connections within the semantic network. This effect is counteracted by affective flattening.