A polymorphism in Toll-interleukin 1 receptor domain containing adaptor protein is associated with susceptibility to meningeal tuberculosis

BACKGROUND: Although meningitis is the most severe form of infection caused by Mycobacterium tuberculosis, the immunopathogenesis of this disease is poorly understood. We tested the hypothesis that polymorphisms in Toll-interleukin 1 receptor domain containing adaptor protein (TIRAP), an adaptor protein that mediates signals from Toll-like receptors activated by mycobacteria, are associated with susceptibility to tuberculosis (TB). METHODS: We used a case-population study design in Vietnam with cord-blood control samples (n = 392) and case patients (n = 358) who had either pulmonary (n = 183) or meningeal (n = 175) TB. RESULTS: The TIRAP single-nucleotide polymorphism (SNP) C558T was associated with increased susceptibility to TB, with a 558T allele frequency of 0.035 in control samples versus 0.074 in case patients (odds ratio [OR], 2.25; P < .001). Subgroup analysis revealed that SNP 558T was more strongly associated with susceptibility to meningeal TB (OR, 3.02; P < .001) than to pulmonary TB (OR, 1.55; P = .22). In comparison to the 558CC genotype, the 558TT genotype was associated with decreased whole-blood interleukin-6 production, which suggests that TIRAP influences disease susceptibility by modulating the inflammatory response. CONCLUSIONS: These results provide the first evidence of an association of a TIRAP SNP with the risk of any disease and also suggest that the Toll-like receptor pathway influences susceptibility to meningeal and pulmonary TB by different immune mechanisms.     

E2-25K mediates US11-triggered retro-translocation of MHC class I heavy chains in a permeabilized cell system

In cells expressing human cytomegalovirus US11 protein, newly synthesized MHC class I heavy chains (HCs) are rapidly dislocated from the endoplasmic reticulum (ER) and degraded in the cytosol, a process that is similar to ER-associated degradation (ERAD), the pathway used for degradation of misfolded ER proteins. US11-triggered movement of HCs into the cytosol requires polyubiquitination, but it is unknown which ubiquitin-conjugating and ubiquitin-ligase enzymes are involved. To identify the ubiquitin-conjugating enzyme (E2) required for dislocation, we used a permeabilized cell system, in which endogenous cytosol can be replaced by cow liver cytosol. By fractionating the cytosol, we show that E2-25K can serve as the sole E2 required for dislocation of HCs in vitro. Purified recombinant E2-25K, together with components that convert this E2 to the active E2-ubiquitin thiolester form, can substitute for crude cytosol. E2-25K cannot be replaced by the conjugating enzymes HsUbc7/Ube2G2 or Ube2G1, even though HsUbc7/Ube2G2 and its yeast homolog Ubc7p are known to participate in ERAD. The activity of E2-25K, as measured by ubiquitin dimer formation, is strikingly enhanced when added to permeabilized cells, likely by membrane-bound ubiquitin protein ligases. To identify these ligases, we tested RING domains of various ligases for their activation of E2-25K in vitro. We found that RING domains of gp78/AMFR, a ligase previously implicated in ERAD, and MARCHVII/axotrophin, a ligase of unknown function, greatly enhanced the activity of E2-25K. We conclude that in permeabilized, US11-expressing cells polyubiquitination of the HC substrate can be catalyzed by E2-25K, perhaps in cooperation with the ligase MARCHVII/axotrophin.     

The use of gene expression analysis and proteomic databases in the development of a screening system to determine the value of natural medicinal products

A rapid throughput screening system involving gene expression analysis was developed in order to investigate the potential of bioactive chemicals contained in natural health products as effective drug therapy, in particular the ability of these chemicals to alleviate the inflammatory response in human airway epithelial cells. A number of databases were searched to retrieve the information needed to properly analyze the gene expression profiles obtained. The gene expression of human bronchial epithelial cells infected with rhinovirus and/or exposed to platelet activating factor was analyzed. Following analysis of the gene expression data the total number of expressed proteins that may potentially act as a marker for monitoring the modulation of airway inflammation was narrowed to 19. Further studies will involve selecting antibodies for these proteins, culturing airway epithelial cells in the presence of extracts of natural health products, extracting the proteins and identifying them by western blot analysis.     

Achieving biventricular circulation in patients with moderate hypoplastic right ventricle in pulmonary atresia intact ventricular septum after transcatheter pulmonary valve perforation

Objective: Transcatheter valve perforation for pulmonary atresia intact ventricular septum is the standard of care for patients with mild right ventricular hypoplasia. However, its role in moderate right ventricular hypoplasia has been less well defined. We sought to report the long‐term outcome of patients with moderate hypoplastic right ventricle who had undergone the procedure.
Design, Settings, and Patients: We performed a retrospective analysis on patients who had undergone transcatheter pulmonary valve perforation from January 1996 to January 2015 at our institution. The procedures would be carried out irrespective of the right ventricular size, as long as there were no absolute contraindications. Intervention and Outcome Measures: Demographic and procedural data were cor‐ related with outcome measures. Outcomes analyzed included procedural success, reintervention rates, final circulation type, and functional class. Multivariate analysis and receiver operator curve were used to identify for parameters in predicting biven‐ tricular circulation.
Results: The procedural success rate was 92% (33 out of 36) in this group with mod‐ erate right ventricular hypoplasia (tricuspid valve z score −4.2 ± 3.0, 69.4% of pa‐ tients with z score <−2.5). Early reintervention rate was 39%, mostly being insertion of modified Blalock–Taussig shunt. Overall reintervention‐free survival was 53%, 30%, and 19% at 1, 6, and 12 months postintervention. Despite no significant catch‐ up right ventricular growth, majority of survivors (84%) enjoyed a biventricular circu‐ lation with good functional status. A tricuspid to mitral valve ratio >0.79 was a good predictor of biventricular outcome. (specificity of 100%, positive predictive value 100%).
Conclusion: Encouraging long‐term results with biventricular circulation and func‐ tional status were demonstrated with transcatheter pulmonary valve perforation in patients even with moderate hypoplastic right ventricle, which is comparable to that with mild right ventricular hypertrophy. The baseline tricuspid to mitral valve ratio was identified as a potentially useful tool in predicting biventricular circulation.     

Multiple sclerosis in pregnancy: prevalence,sociodemographic features,and obstetrical outcomes

Objective: We sought to describe the prevalence, sociodemographic features, and antenatal/peripartum outcomes of multiple sclerosis (MS) in pregnancy.

Study design: A retrospective cohort study was performed using deliveries in California from 2001 to 2009. Cases of MS as well as other morbidities were identified via ICD-9-CM code. Logistic regression was performed to adjust for potential confounders.

Results: About 1185 out of 4,424,049 deliveries were complicated by MS. MS prevalence increased with maternal age, with Caucasians comprising a higher proportion of MS subjects. MS subjects were older and more likely to have private insurance. Women with MS were more likely to have preexisting medical conditions such as asthma, chronic hypertension, thyroid disease, or cardiac disease. However, no significant antepartum and peripartum morbidities were found to be increased in patients with MS. Urinary tract infection, cesarean delivery, and induction of labor were slightly increased in MS patients.

Conclusions: MS is a rare condition which is more likely to affect older Caucasian women of higher socioeconomic status and is associated with several preexisting medical conditions. MS, however, does not appear to pose significant increases in adverse pregnancy outcome. This suggests that pregnant patients with MS may likely experience an uneventful pregnancy.     

Preliminary investigation about the expression of tubulin in platelets from patients with iron deficiency anemia and thrombocytosis

Objective: In order to inquire into the pathogenesis of increased platelet counts in peripheral blood of patients with iron deficiency anemia (IDA), the phenomenon of thrombocytosis was confirmed, and then the expression of tubulin within platelets from IDA patients was investigated.

Methods: Peripheral blood samples were collected from 79 patients with IDA and were divided into 2 groups, group of IDA with normal platelet counts (34 cases), and group of IDA with increased platelet counts (thrombocytosis) (45 cases). Additionally, 45 peripheral blood samples from healthy volunteers were enrolled as a group of healthy controls. Count of platelets in peripheral blood was detected by means of LH-780 hematology analyzer and hemocytometer under a microscope respectively, and analyzed statistically.

Results: There was no statistical difference between platelet counts detected by LH-780 hematology analyzer and hemocytometer under a microscope (P?>?.05). The mean fluorescence intensity (MFI) of both α-tubulin and β-tubulin within platelets from IDA patients with thrombocytosis was significantly less than that from healthy volunteers and IDA patients with normal platelet counts (P?P?>?.05).

Conclusion: Some patients with IDA are accompanied by thrombocytosis, from which the expression of α-tubulin and β-tubulin within platelets reduced obviously compared with those with normal platelet counts and healthy controls respectively. It is implied that downregulation of tubulin probably is a part of the pathogenesis leading to increased platelet counts in IDA.     

Effects of empagliflozin on cardiorespiratory fitness and significant interaction of loop diuretics

The effects of empagliflozin on cardiorespiratory fitness in patients with type 2 diabetes mellitus (T2DM) and heart failure with reduced ejection fraction (HFrEF) are unknown. In this pilot study we determined the effects of empagliflozin 10 mg/d for 4 weeks on peak oxygen consumption (VO₂) in 15 patients with T2DM and HFrEF. As an exploratory analysis, we assessed whether there was an interaction of the effects of empagliflozin on peak VO₂ of loop diuretics. Empagliflozin reduced body weight (?1.7 kg; P = .031), but did not change peak VO₂ (from 14.5 mL kg^?1 min^?1 [12.6‐17.8] to 15.8 [12.5‐17.4] mL kg^?1 min^?1; P = .95). However, patients using loop diuretics (N = 9) demonstrated an improvement, whereas those without loop diuretics (N = 6) experienced a decrease in peak VO₂ (+0.9 [0.1‐1.4] vs ?0.9 [?2.1 to ?0.3] mL kg^?1 min^?1; P = .001), and peak VO₂ changes correlated with the baseline daily dose of diuretics (R = +0.83; P < .001). Empagliflozin did not improve peak VO₂ in patients with T2DM and HFrEF. However, as a result of exploratory analysis, patients concomitantly treated with loop diuretics experienced a significant improvement in peak VO₂.