Electroanatomical voltage mapping with contact force sensing for diagnosis of arrhythmogenic right ventricular cardiomyopathy

BACKGROUND

Three-dimensional electroanatomical mapping (EAM) can be helpful to diagnose arrhythmogenic right ventricular cardiomyopathy (ARVC). Yet, previous studies utilizing EAM have not systematically used contact-force sensing catheters (CFSC) to characterize the substrate in ARVC, which is the current gold standard to assure adequate tissue contact.

OBJECTIVE

To investigate reference values for endocardial right ventricular (RV) EAM as well as substrate characterization in patients with ARVC by using CFSC.

METHODS

Endocardial RV EAM during sinus rhythm was performed with CFSC in 12 patients with definite ARVC and 5 matched controls without structural heart disease. A subanalysis for the RV outflow tract (RVOT), septum, free-wall, subtricuspid region, and apex was performed. Endocardial bipolar and unipolar voltage amplitudes (BVA, UVA), signal characteristics and duration as well as the impact of catheter orientation on endocardial signals were also investigated.

RESULTS

ARVC patients showed lower BVA vs. controls (p = 0.018), particularly in the subtricuspid region (1.4, IQR:0.5-3.1 vs. 3.8, IQR:2.5-5 mV, p = 0.037) and RV apex (2.5, IQR:1.5-4 vs. 4.3,IQR:2.9-6.1 mV, p = 0.019). BVA in all RV regions yielded a high sensitivity and specificity for ARVC diagnosis (AUC 59-78%, p < 0.05 for all), with the highest performance for the subtricuspid region (AUC 78%, 95% CI:0.75-0.81, p < 0.001, negative predictive value 100%). A positive correlation between BVA and an orthogonal catheter orientation (46°-90°:r = 0.106, p < 0.001), and a negative correlation between BVA and EGM duration (r = -0.370, p < 0.001) was found.

CONCLUSIONS

EAM using CFSC validates previous bipolar cut-off values for normal endocardial RV voltage amplitudes. RV voltages are generally lower in ARVC as compared to controls, with the subtricuspid area being commonly affected and having the highest discriminatory power to differentiate between ARVC and healthy controls. Therefore, EAM using CFSC constitutes a promising tool for diagnosis of ARVC.

COVID-19 pandemic and admission rates for and management of acute coronary syndromes in Israel

Background

Since the COVID-19 pandemic outbreak several countries have reported a decrease in the number of patients admitted with non-ST elevation myocardial infarction (NSTEMI).

Purpose

We aimed to evaluate admission trend and outcomes of patients with NSTEMI in the COVID-19 era in a nationwide survey.

Methods

A prospective, multicenter, observational, nationwide study involving 13 medical centers across Israel. All NSTEMI patients admitted to intensive cardiac care units (ICCUs) over an 8-week period during the COVID-19 outbreak were compare them with NSTEMI patients admitted 2 years earlier (control period) during the Acute Coronary Syndrome Israeli Survey (ACSIS) 2018.

Results

There were 624 (43%) NSTEMI patients, of them 349 (56%) hospitalized during the COVID-19 era and 275 (44%) during the control period, representing a 27% increase in NSTEMI admission rate during the COVID-19 era. Approximately 76% were male, median age was 67 years (IQR 58–76). There were no differences in baseline characteristics between the two study periods. During the COVID-19 era, more patients arrived at the hospital via an emergency medical system (EMS) compared with the control period (p for trend = 0.005)

Time from symptom onset to hospital admission was longer in the COVID-19 era [687.00 (IQR147–2805) vs. 178.00 (IQR 102- 407), respectively, p-value &lt;0.001]. Nevertheless, time from hospital admission to reperfusion was similar in both groups. Rate of percutaneous coronary intervention was higher in the COVID-19 era group (91.3% vs. 59.7%, respectively, p&lt;0.001). In-hospital mortality rate was similar in both groups (2.3% vs. 4.7%, respectively, p=0.149) as was the 30-day mortality rate (3.7% vs. 5.1%, respectively, p=0.238).

Conclusions

In contrast to previous reports, in Israel, admission rate of NSTEMI was increased during the COVID-19 era. With longer time from symptoms to admission, but with the same time from hospital admission to reperfusion therapy and with similar in-hospital and 30-day mortality rates.

Funding Acknowledgement

Type of funding sources: None.

CO2 laser ablation of oral leukoplakia: with or without extension of margins?

PURPOSE

The purpose is to determine the sufficient extension of margins during laser ablation of oral leukoplakia and observe its short-term recurrence rate.

MATERIALS AND METHODS

The study was designed as a randomized controlled clinical trial was conducted on 33 oral leukoplakia lesions diagnosed in 30 patients (16 Females and 14 Males) with an age range between 39 and 79 years. The lesions were divided into three groups; Group A: 11 lesions in 11 patients, in which the laser ablation was done for the entire lesion without extension of margins; Group B: 11 lesions in 8 patients, in which the laser ablation was done for the lesion adding at least 3mm extension of margins; and finally the Group Control: consists of 11 untreated lesions in 11 patients, in which only "wait and see" approach was done.

RESULTS

Complete healing of 13 lesions occurred in both groups A and B. Complete regression of 3 lesions occurred in Group Control. After 6 months of follow-up, 6 of 9 lesions in both groups A and B that showed the recurrence, had shown an initial recurrence after 3 weeks of the laser ablation. Patients with no history of smoking habits showed complete healing of 87.5%, while in ex-smokers complete healing was 42.8%. The statistical analysis was performed, and the averages of all groups are significantly different (p <0.00001).

DISCUSSION

The primary treatment focuses on the elimination of associated risk factors (smoking, alcohol, and local irritating factors). In the literature, the recurrence rate varies between 13.6% and 40.7%, while in our study, it was 45.5% in Group A and 36.4% in Group B.

CONCLUSION

The recommended extension of margins should be at least 3mm in width. Further research can be performed to evaluate the immediate re-ablation of the lesions which showed an initial recurrence after 3 weeks of laser ablation.

Assessment of Atmospheric heavy metal deposition in North Egypt aerosols using neutron activation analysis and optical emission inductively coupled plasma

The aim of the present study is to assess the current level of atmospheric heavy metal pollution of aerosols in different cities of North Egypt using the neutron activation analysis and optical emission inductively coupled plasma techniques. The results revealed that the highest concentrations of particulate matter PM₁₀ and total suspended particulate matter were close to industrial areas. From the results of the enrichment factor calculations, the most significant elements of anthropogenic origin are Ba, Sb, Ce and Zn.

Pharmacokinetic comparison of two 40 mg tablet formulations of citalopram using a new amperometric detection technique

OBJECTIVES

To assess the bio-equivalence of two citalopram 40 mg tablet formulations (Lecital of the Jordan Sweden Medical and Sterilization Co. (JOSWE) as a test product, and Cipramil of Lundbeck (Denmark) as a reference product), and to develop a new high-performance liquid chromatography (HPLC) method using liquid-liquid extraction followed by addition of acid for the quantification of citalopram in human plasma.

METHODS

A single-blind, randomized, single-dose, 2-treatment, 2-period, 2-sequence, crossover bioequivalence study with a 20-day washout period in 24 healthy volunteers. The drug was administered with 240 ml of water after 10-h overnight fasting. After dosing, serial blood samples were collected for a period of 192 h. Plasma harvested from blood was analyzed for citalopram by a novel method using HPLC coupled with an electrochemical detector. The limit of quantitation of citalopram was 1.493 ng/ml. Matrix-based calibration curves were linear over the range 1.493 - 80.640 ng/ml for citalopram.

RESULTS

The average bioavailability and pharmacokinetic parameters of the two citalopram tablets were as follows: peak plasma concentration Cmax was 35.0 +/- 10.04 ng/ml and 33.4 +/-7.80 ng/ml for Lecital and Cipramil, respectively. The time to peak plasma concentrations tmax were 3.81 +/- 1.18 and 4.08 +/- 1.54 h, while the plasma half-life (t1/2) values were 54.0 +/- 7.50 and 54.7 +/- 10.6 h. The area under the plasma concentration-time profiles AUCo-t were 1,820 +/- 582 ng x h/ml and 1,660 +/- 510 ng x h/ml, whereas the AUC0-infinity were 2,010 +/- 663 ng x h/ml and 1,850 +/- 577 ng x h/ml for Lecital and Cipramil, respectively. The 90% confidence intervals for test/reference ratio were found within the acceptable limits of 80 - 125%, consequently no significant difference was found between the test and reference.

CONCLUSION

Based on the pharmacokinetic and statistical results, it was concluded that Lecital 40 mg tablets of JOSWE is bioequivalent to Cipramil 40 mg tablets of Lundbeck (Denmark).

Efficacy of Thermotherapy to Treat Cutaneous Leishmaniasis Caused byLeishmania tropicain Kabul, Afghanistan: A Randomized, Controlled Trial

BACKGROUND

Pentavalent antimony is the agent recommended for treatment of cutaneous leishmaniasis (CL). Its use is problematic, because it is expensive and because of the potential for drug-associated adverse effects during a lengthy and painful treatment course.

METHODS

We tested the efficacy of thermotherapy for the treatment of CL due to Leishmania tropica in a randomized, controlled trial in Kabul, Afghanistan. We enrolled 401 patients with a single CL lesion and administered thermotherapy using radio-frequency waves (1 treatment of >or=1 consecutive application at 50 degrees C for 30 s) or sodium stibogluconate (SSG), administered either intralesionally (a total of 5 injections of 2-5 mL every 5-7 days, depending on lesion size) or intramuscularly (20 mg/kg daily for 21 days).

RESULTS

Cure, defined as complete reepithelialization at 100 days after treatment initiation, was observed in 75 (69.4%) of 108 patients who received thermotherapy, 70 (75.3%) of 93 patients who received intralesional SSG, and 26 (44.8%) of 58 patients who received intramuscular SSG. The OR for cure with thermotherapy was 2.80 (95% confidence interval [CI], 1.45-5.41), compared with intramuscular SSG treatment (P=.002). No statistically significant difference was observed in the odds of cure in comparison of intralesional SSG and thermotherapy treatments. The OR for cure with intralesional SSG treatment was 3.75 (95% CI, 1.86-7.54), compared with intramuscular SSG treatment (P<.001). The time to cure was significantly shorter in the thermotherapy group (median, 53 days) than in the intralesional SSG or intramuscularly SSG group (median, 75 days and >100 days, respectively; P=.003).

CONCLUSIONS

Thermotherapy is an effective, comparatively well-tolerated, and rapid treatment for CL, and it should be considered as an alternative to antimony treatment.

A randomized controlled trial of insecticide-treated bednets and chaddars or top sheets, and residual spraying of interior rooms for the prevention of cutaneous leishmaniasis in Kabul, Afghanistan

Anthroponotic cutaneous leishmaniasis (ACL) is a significant public health problem in many towns and cities of south central Asia and the Middle East, resulting in disfigurement and disability which warrants preventive action. A randomized controlled trial was conducted in 1997/98 amongst a non-immune study population of 3666 people in Kabul, Afghanistan, to compare the efficacy of insecticide-treated nets (ITNs), insecticide-treated Islamic cloth wraps (chaddars) used to sleep in, and residual pyrethroid spraying of individual houses for the prevention of ACL. Dosages of insecticide were: ITNs with permethrin, 0.5 g/m2; chaddars with permethrin, 1 g/m2; rooms with lambdacyhalothrin, 30 mg/m2. Cases of ACL were diagnosed on clinical criteria. At the end of the trial period (15 months) the incidence of ACL amongst controls was 7.2%, amongst ITN users 2.4% (OR 0.31, 95% CI 0.2-0.5), amongst impregnated chaddar users 2.5% (OR 0.33, 95% CI 0.2-0.6) and amongst residents of sprayed houses 4.4% (OR 0.60, 95% CI 0.3-0.95). ITNs and impregnated chaddars were equally effective, providing about 65% protective efficacy, with approximately 40% protective efficacy attributable to individual house spraying. No significant differences for age or sex were found between new cases in the intervention and control groups. No serious side-effects were reported and interventions were generally popular; ITNs were the most popular, followed by residual spraying and then impregnated chaddars.

An SOD-mimicry mechanism underlies the role of nitroxides in protecting papain from oxidative inactivation

Nitroxide stable free radicals have previously been found to afford protection in various biological systems against diverse types of oxidative stress, including, ischemia/reperfusion, hyperoxia, mechanical trauma, toxic xenobiotics, ionizing radiation, gastric and colonic irritants or strong oxidants. Dismutation of superoxide has originally been suggested to be one of the mechanisms that underlie the anti-oxidant effect of nitroxides. However, no direct evidence has been found, so far, to support this assumption. In the present study, superoxide and H2O2, generated enzymatically, were used to directly inactivate papain, a sulfhydryl enzyme, in vitro. The rate of papain inactivation served to assess the damage. The reaction mixtures contained a chelate in order to prevent the effect of adventitious redox-active metal ions, pre-empt the Fenton reaction and avoid hydroxyl-induced damage. Catalase or SOD alone partially protected the papain from inactivation. The protective effect of nitroxides resembled that of SOD in several aspects: a) nitroxides provided partial protection; b) the protective effect of nitroxides did not increase with the elevation of their concentration (above 0.5 mM); c) the combined addition of SOD and the nitroxide did not provide greater protection than that demonstrated by nitroxides or SOD separately; d) the effects of catalase with the nitroxide were additive; e) the nitroxide, like SOD itself, did not protect papain from H2O2-induced inactivation; f) the nitroxide was found not to be consumed in the course of the reaction but rather to be recycled. The results indicate that: (a) the main species responsible for the papain inactivation in a system in which the effect of transition metals is pre-empted, are O2-. and H2O2; (b) nitroxides inhibit the oxidative damage by removing superoxide not stoichiometrically, but rather catalytically as SOD-mimics; (c) nitroxides do not afford protection when the oxidative damage is induced directly by H2O2 (and not mediated by redox-active metals).

Do nitroxides protect cardiomyocytes from hydrogen peroxide or superoxide?

The aim of the research was to study the role played by extracellular O2-radicals, which are implicated in cardiac cell damage and the protective effect by cell-permeable, nitroxide, superoxide dismutase-mimics. Cardiomyocytes cultures from 1-day-old rats served as the test-system. Experiments were performed since 5th day in culture when > 80% of the cells were beating myocardial cells. Oxidative damage was induced by 0.5 mM hypoxanthine and 0.06 U/ml xanthine oxidase or by 10 mM glucose and 0.15 U/ml glucose oxidase. The parameters used to evaluate damages were spontaneous beating, lactate dehydrogenase release and ATP level. The rhythmic pulsation was followed microscopically. To determine the kinetics of cytosolic enzyme release from the cells, media samples were collected at various points of time and assayed for enzyme activity. To determine the cellular ATP, cells were washed with sodium phosphate buffer, scraped off and boiled for 3 min with sodium phosphate buffer. Following centrifugation the supernatant was collected and ATP was determined by the chemiluminogenic assay using firefly tails. The present results indicate that nitroxide stable free radicals in the millimolar concentration range, provide full protection without toxic side-effect. Unlike exogenously added SOD that failed to protect, exogenous catalase provided almost full protection. In addition, the metal-chelating agent dipyridyl, but not diethylene-triamine-pentaacetate or desferrioxamine, protected the cultured cells. The present results suggest that H2O2 is the predominant toxic species mediating the oxidative damage whereas extracellular superoxide radical does not contribute to cultured cardiomyocyte damage.(ABSTRACT TRUNCATED AT 250 WORDS)

Structural requirements for inhibition of melanoma lung colonization by heparanase inhibiting species of heparin

Heparanase activity correlates with metastatic potentials of lymphoma, melanoma and mammary adenocarcinoma cell lines. We investigated the ability of various modified species of heparin and size homogeneous oligosaccharides derived from depolymerized heparin to inhibit: a) heparanase-mediated degradation of heparan sulfate (HS) in the extracellular matrix (ECM) deposited by cultured endothelial cells, and b) lung colonization of B16-BL6 melanoma cells in C57BL mice. For this purpose, melanoma cells or conditioned medium were incubated with metabolically sulfate-labeled subendothelial ECM in the absence and presence of heparin, heparin fragment or nonanticoagulant species of heparin. Labeled HS degradation fragments released into the incubation medium were analyzed by gel filtration over Sepharose 6B. The B16-BL6 melanoma cells were also tested for lung colonization following their intravenous administration to C57BL mice, in the absence and presence of the various species of heparin. Inhibition of both heparanase and melanoma lung colonization depended on the size and degree of sulfation of the heparin molecule, the position of sulfate groups, and the occupancy of the N position of the hexosamines. Inhibition of heparanase was best achieved by heparin species containing 16 sugar units or more and having sulfate groups at both the N and O positions. Low sulfate oligosaccharides were less effective heparanase inhibitors than medium and high sulfate fractions of the same size saccharide. While O-desulfation abolished the heparanase inhibiting effect of heparin. O-sulfated, N-substituted (e.g., N-acetyl or N-hexanoyl) species of heparin retained a high inhibitory activity, provided that the N-substituted molecules had a molecular size of about > or = 4,000 daltons. Potent inhibitors of heparanase activity were also efficient inhibitors of tumor invasion and lung colonization. The antimetastatic and anticoagulant activities of heparin were unrelated, as indicated by using heparin fractions with high and low affinity for antithrombin III. These heparins differ about 200-fold in their anticoagulant activity, but expressed similar high antiheparanase and antimetastatic activities. It appears that heparanase-inhibiting species of heparin interfere with the passing of tumor cells across the capillary wall, as they significantly inhibited metastasis even when injected up to 3 h after lodgment. Structural requirements for inhibition of heparanase activity and lung colonization of melanoma cells by species of heparin were different from those identified for a) release of ECM-bound basic fibroblast growth factor (bFGF), and b) stimulation of bFGF receptor binding and mitogenic activity.(ABSTRACT TRUNCATED AT 400 WORDS)

Effects of nitroxide stable radicals on juglone cytotoxicity

Nitroxides stable radicals are unreactive toward most diamagnetic molecules, but readily undergo one-electron redox reactions with paramagnetic species such as free radicals and transition metals, thus serving as cell-permeable antioxidants. The cytotoxicity of juglone (5-hydroxy-1,4-naphthoquinone), like that of other naphthoquinones, requires bioreduction to yield the semiquinone which in turn reduces oxygen to O2.-. Therefore, nitroxides are expected to mitigate cytotoxicity of quinone-based xenobiotics, such as naphthoquinones. In the present study, in vitro scission of isolated DNA was induced upon juglone reduction by glutathione and Fe(II) ions, however, not by xanthine oxidase or cytochrome c reductase. The DNA scission was inhibited by nitroxides, catalase and chelating agents, though not by superoxide dismutase. Juglone was more toxic toward bacterial cells under hypoxia than under air. Nitroxides < or = 2 mM protected bacterial cells from juglone-induced toxicity under both aerobic and hypoxic conditions. The cytoprotective effect of lipophilic nitroxide was greater than that of hydrophilic ones. Catalase and metal chelating agents decreased juglone-induced cell killing, whereas H2O2 increased it. The mechanisms underlying the nitroxides protective effect involve (a) the reoxidation of reduced transition metal ions, (b) the selective radical-radical reaction with juglone semiquinone, and possibly (c) under aerobic condition catalytic removal of extra- and intracellular O2.-. The present results suggest also that the cell membrane rather than DNA is the main target of juglone toxicity.