The Accuracy of Diagnosis and Genotyping of Leishmania Species Based on Spliced Leader Mini-Exon Gene by Nuclear Magnetic Resonance and Sequencing Assays

Background

We aimed to evaluate the accuracy of genotyping of Leishmania species by the spliced leader mini-exon gene.

Methods

Suspected leishmaniasis patients, referred to Masieh Daneshvary Hospital, Tehran, Iran were included from May 2017 to September 2021. The Leishmania species were genotyped by PCRRFLP based on the SL mini-exon gene and the ITS1 region of SSU-rRNA gene and compared with the sequencing results. The expressed metabolites of metacyclic promastigotes were evaluated by Proton nuclear magnetic resonance (1H-NMR).

Results

Out of 66 suspected cases, 36 (54.4%) were positive for Leishmania species based on the PCR assays. In 21 (31.8%) cases, promastigotes grew on culture tubes. Based on the RFLP of SL RNA profile, 13 (19.7%) L. tropica, 9 (13.6%) L. major, 3 (4.5%) L. infantum, and 8 (12.1%) C. fasciculata isolates, isolated from culture media, were identified; however, 3 (4.5%) cases were unidentifiable due to the low number of parasites. Seventeen metabolites were expressed by the metacyclic forms of L. major, L. tropica and C. fasciculata isolates. The top differential metabolites expressed more in C. fasciculata were FAD, p-Methoxybenzyl alcohol and S-b-G-5, 5-G-b-S (A = CH2) (P<0.005) whereas Veratryl glycerols and D-(+)-Mannose were significantly increased in L. major and Betulin, LTyrosine in L. tropica (P<0.01).

Conclusion

The invaluable techniques such as sequencing and 1H-NMR confirmed the results of genotyping of Leishmania species based on the SL mini-exon gene. SL mini exon gene can be used as a diagnostic tool to differentiate various Leishmania genotypes and detect contamination of culture media with C. fasciculata.

Long-term efficacy and health consumption before and after ablation of AF

Background

Atrial fibrillation (AF), the most common arrhythmia worldwide, is associated with increased morbidity and mortality. Catheter ablation of AF is the most effective treatment option for symptomatic patients. The long-term efficacy is however not very well studied nor is health consumption before and after an ablation of atrial fibrillation.

Purpose

To study the long-term efficacy and health consumption before and after an ablation of AF in 1453 consecutive patients undergoing ablation in our institution.

Methods

Consecutive patients undergoing radiofrequency ablation for AF were included prospectively. 4 mm irrigated ablation (Biosense Webster) catheters and Carto® were used for all procedures. After a mean period of 4 years a survey measuring arrhythmia symptoms was sent out to all patients who were treated with an ablation of AF between 1st of January 2010 and 31st of December 2016. Data was collected from local registries, the national registry for catheter ablations and the national health registry. Health consumption measured as in-hospital visits two years before and after the procedure was assessed.

Results

877 (72.7%) patients had no further symptomatic arrhythmia four years after the procedure. Among the 329 patients who still reported symptoms 237 (72%) had milder, 65 (20%) had unchanged and 20 (8%, 1.3% of total) had worsened symptoms after e ablation.

The total number of in-hospital visits 2 years before and after the ablation was 4067. There were 2594 in-hospital visits before and 1473 after the ablation, a decrease by 43%. The majority of the these were arrhythmia related, 2264 and 908, respectively, a decrease by 60%. Seven patients had a stroke before the ablation and five after. The median length of stay was 1 day both before and after the ablation.

Conclusion

Health consumption is significantly decreased after an ablation for AF. The long-term effect is good with freedom of symptomatic AF of approximately 70% after four years.

Funding Acknowledgement

Type of funding sources: Private grant(s) and/or Sponsorship. Main funding source(s): Biosense Webster Inc

A Nuclear Magnetic Resonance-Based Metabolomic Study to Identify Metabolite Differences between Iranian Isolates of Leishmania major and Leishmania tropica

Background

Cutaneous leishmaniasis caused by Leishmania species (L. spp) is one of the most important parasitic diseases in humans. To gain information on the metabolite variations and biochemical pathways between L. spp, we used the comparative metabolome of metacyclic promastigotes in the Iranian isolates of L. major and L. tropica by proton nuclear magnetic resonance (¹H-NMR).

Methods

L. tropica and L. major were collected from three areas of Iran, namely Gonbad, Mashhad, and Bam, between 2017 and 2018, and were cultured. The metacyclic promastigote of each species was separated, and cell metabolites were extracted. ¹H-NMR spectroscopy was applied, and the data were processed using ProMatab in MATLAB (version 7.8.0.347). Multivariate statistical analyses, including the principal component analysis and the orthogonal projections to latent structures discriminant analysis, were performed to identify the discriminative metabolites between the two L. spp. Metabolites with variable influences in projection values of more than one and a P value of less than 0.05 were marked as significant differences.

Results

A set of metabolites were detected, and 24 significantly differentially expressed metabolites were found between the metacyclic forms of L. major and L. tropica isolates. The top differential metabolites were methionine, aspartate, betaine, and acetylcarnitine, which were increased more in L. tropica than L. major (P<0.005), whereas asparagine, 3-hydroxybutyrate, L-proline, and kynurenine were increased significantly in L. major (P<0.01). The significantly altered metabolites were involved in eight metabolic pathways.

Conclusion

Metabolomics, as an invaluable technique, yielded significant metabolites, and their biochemical pathways related to the metacyclic promastigotes of L. major and L. tropica. The findings offer greater insights into parasite biology and how pathogens adapt to their hosts.

A systems medicine approach reveals disordered immune system and lipid metabolism in multiple sclerosis patients

Identification of autoimmune processes and introduction of new autoantigens involved in the pathogenesis of multiple sclerosis (MS) can be helpful in the design of new drugs to prevent unresponsiveness and side effects in patients. To find significant changes, we evaluated the autoantibody repertoires in newly diagnosed relapsing-remitting MS patients (NDP) and those receiving disease-modifying therapy (RP). Through a random peptide phage library, a panel of NDP- and RP-specific peptides was identified, producing two protein data sets visualized using Gephi, based on protein--protein interactions in the STRING database. The top modules of NDP and RP networks were assessed using Enrichr. Based on the findings, a set of proteins, including ATP binding cassette subfamily C member 1 (ABCC1), neurogenic locus notch homologue protein 1 (NOTCH1), hepatocyte growth factor receptor (MET), RAF proto-oncogene serine/threonine-protein kinase (RAF1) and proto-oncogene vav (VAV1) was found in NDP and was involved in over-represented terms correlated with cell-mediated immunity and cancer. In contrast, transcription factor RelB (RELB), histone acetyltransferase p300 (EP300), acetyl-CoA carboxylase 2 (ACACB), adiponectin (ADIPOQ) and phosphoenolpyruvate carboxykinase 2 mitochondrial (PCK2) had major contributions to viral infections and lipid metabolism as significant events in RP. According to these findings, further research is required to demonstrate the pathogenic roles of such proteins and autoantibodies targeting them in MS and to develop therapeutic agents which can ameliorate disease severity.

Long-term prognosis in patients with bifascicular block--the predictive value of noninvasive and invasive assessment

OBJECTIVES

Patients with bifascicular block (BFB) have a high mortality rate. The purpose of the present study was to identify high-risk patients in a BFB population by performing an extensive cardiac evaluation including noninvasive and invasive tests.

DESIGN

Population-based study.

SUBJECTS

A total of 100 patients with BFB, of whom 41 had a history of unexplained syncope, were prospectively studied. The mean age was 68 +/- 12. All patients were investigated with Holter-monitoring, an exercise test, an echocardiography, and an invasive electrophysiological study. The severity of congestive heart failure (CHF) was assessed by New York Heart Association (NYHA) classification. Patients in NYHA class IV were excluded.

INTERVENTIONS

Patients with syncope were recommended prophylactic pacemaker treatment, which was accepted by 31 patients (76%). Main outcome measures. All-cause mortality and sudden cardiac death (SCD).

RESULTS

During a median follow-up of 84 months, 33 patients died, of whom 14 in SCD. In a univariate analysis, high age, a previous myocardial infarction, and CHF were associated with a significantly increased risk of all-cause mortality and SCD. In a Cox multiple regression analysis, CHF was the only independent predictor of all-cause mortality and SCD (P < 0.01).

CONCLUSION

Patients with BFB have a poor long-term prognosis. The predictive value of noninvasive and invasive investigations is limited. The only independent predictor of all-cause mortality and SCD in this population was the presence of CHF.