ECG Feature Extraction Based on Multiresolution Wavelet Transform

In this work, we have developed and evaluated an electrocardiogram (ECG) feature extraction system based on the multi-resolution wavelet transform. ECG signals from Modified Lead II (MLII) are chosen for processing. The result of applying two wavelet filters (D4 and D6) of different length on the signal is compared. The wavelet filter with scaling function more closely to the shape of the ECG signal achieved better detection. In the first step, the ECG signal was de-noised by removing the corresponding wavelet coefficients at higher scales. Then, QRS complexes are detected and each complex is used to locate the peaks of the individual waves, including onsets and offsets of the P and T waves which are present in one cardiac cycle. We evaluated the algorithm on MIT-BIH Database, the manually annotated database, for validation purposes. The proposed QRS detector achieved sensitivity of 75. 2 % 18 . 99 .. and a positive predictivity of 45 . 4 % 00 . 98 .. over the validation database.

Probiotics function and modulation of the immune system in allergic diseases

Allergic diseases have been a global problem over the past few decades. The effect of allergic diseases on healthcare systems and society is generally remarkable and is considered as one of the most common causes of chronic and hospitalized disease. The functional ability of probiotics to modulate the innate/acquired immune system leads to the initiation of mucosal/systemic immune responses. Gut microbiota plays a beneficial role in food digestion, development of the immune system, control/growth of the intestinal epithelial cells and their differentiation. Prescribing probiotics causes a significant change in the intestinal microflora and modulates cytokine secretion, including networks of genes, TLRs, signaling molecules and increased intestinal IgA responses. The modulation of the Th1/Th2 balance is done by probiotics, which suppress Th2 responses with shifts to Th1 and thereby prevent allergies. In general, probiotics are associated with a decrease in inflammation by increasing butyrate production and induction of tolerance with an increase in the ratio of cytokines such as IL-4, IL-10/IFN-γ, Treg/TGF-β, reducing serum eosinophil levels and the expression of metalloproteinase-9 which contribute to the improvement of the allergic disease's symptoms. Finally, it can be said that the therapeutic approach to immunotherapy and the reduction of the risk of side effects in the treatment of allergic diseases is the first priority of treatment and the final approach that completes the first priority in maintaining the condition and sustainability of the tolerance along with the recovery of the individual.

Diagnostic clues from the surface ECG to identify idiopathic (fascicular) ventricular tachycardia: correlation with electrophysiologic findings

INTRODUCTION

An RS interval > 100 msec in precordial leads has been recently described for the diagnosis of ventricular tachycardia (VT). The aim of this study was to assess the value of this criterion when applied to patients with right bundle branch block pattern, left-axis deviation (fascicular) VT sensitive to verapamil.

METHODS AND RESULTS

Eleven patients (mean age 31 +/- 11 years; range 16 to 51) had a mean heart rate of 164 +/- 37 beats/min (range 107 to 230) during VT. The QRS complex axis was -92 degrees +/- -15 degrees (range -80 to -115). The mean QRS duration was 121 +/- 9 msec (range 105 to 140). The mean RS interval was 67 +/- 9 msec (range 60 to 80). Fusion beats were present in 2 patients (18%), and AV dissociation confirmed by electrophysiologic study was found on ECG in 8 (73%) of 11. During tachycardia, the QRS-H' interval was 19 +/- 10 msec (range 10 to 30) in 6 of 11 patients. In seven patients, a fast, unique (or double) presystolic potential lasting 32 msec (range 12 to 40) occurring before the onset of the QRS complex was found at the site of origin of VT, localized in the inferior apical left ventricular septum. In all cases, VT was successfully treated by catheter ablation.

CONCLUSION

A wide QRS complex tachycardia with right bundle branch block and left-axis deviation sensitive to verapamil observed in a young patient without structural heart disease should not be confused with supraventricular tachycardia with aberrancy but rather suggests the presence of fascicular VT. As opposed to VT associated with structural heart disease, the RS interval is < 80 msec in all precordial leads in all cases. Independent of this parameter, AV dissociation detectable on surface ECG has a sensitivity of 73%, which increases to 82% in the presence of fusion beats.

Risk factors and control strategies for silicotuberculosis as an occupational disease

Silicotuberculosis is critical in community settings among workers and employees exposed to silica dust. Older age of entry (>30 years), male sex, infection with human immunodeficiency virus (HIV), exposure duration, smoking, chronic obstructive pulmonary disease, migration, the severity of the silicosis and the intensity of the exposure are potential risk factors. Lack of timely diagnosis and treatment for tuberculosis (TB) may also raise the rate of infection; previous treatment of TB is possibly associated with the development of silicotuberculosis in more than half of patients, increasing with age (>40 years). Identification of risk factors benefits not only the academic research community, but also the workers or employees and policy making. Some strategies can be implemented, such as controlling or reducing exposure to silica dust, ensuring continuity of treatment of TB or extended anti-TB treatment, management of the situation by occupational health professionals, prevention of oscillating migration, providing workers with compensation, training and education in occupational health, improving the quality of life of miners and workers, intensive medical surveillance and TB screening in routine health check ups, and policy making for higher immunity to inhibit inhalation of dust by workers or employees.

Dietary pattern, colonic microbiota and immunometabolism interaction: new frontiers for diabetes mellitus and related disorders

In this review, the numerous possible mechanisms that provide supportive evidence for how colonic dysbiosis denotes metabolic dysfunction, dysregulates glucose homeostasis and leads to diabetes mellitus and related metabolic disorders are defined. Information was gathered from articles identified by systematic reviews and searches using Google, PubMed and Scopus. The composition of the colonic microbiota plays an integral role in maintaining host homeostasis by affecting both metabolic activities and underlying functional gene transcription in individuals with diabetes and related metabolic disorders. Increased colonic microbiome-derived concentrations of lipopolysaccharides, also known as 'metabolic endotoxaemia', as well as alterations in bile acid metabolism, short-chain fatty acids, intestinal hormones and branched-chain amino acid secretion have been associated with the diverse production of pro-inflammatory cytokines and the recruitment of inflammatory cells. It has been shown that changes to intestinal bacterial composition are significant even in early childhood and are associated with the pathogenesis of both types of diabetes. We hope that an improved understanding of related mechanisms linking the colonic microbiome with glucose metabolism might provide for innovative therapeutic approaches that would bring the ideal intestinal ecosystem to a state of optimal health, thus preventing and treating diabetes and related metabolic disorders.

Improvement in the resolution of o-phthalaldehyde derivatized amino acids by applying gradient steepness optimization to five reversed-phase columns of different lengths and particle sizes

Twenty-two o-phthalaldehyde (OPA) derivatized amino acids were separated on five different reversed-phase, octadecyl columns. Each column was packed with the same type of spherical silica on which matched bonding chemistry had been performed. Columns of 250, 150 or 50 mm x 4.5 mm I.D. were packed with 5 microns particles, and columns of 100 or 50 mm x 4.5 mm I.D. were packed with 3 microns particles. Snyder's linear solvent strength gradient optimization method was used to determine the optimum gradient steepness by maximizing the resolution of four pairs of adjacent OPA-derivatized amino acids. An asymptotic dependence of improvement in resolution with increase in gradient time was obtained for each pair of compounds on each column. For short (50 mm) columns, resolution of very closely eluting compounds required the use of gradient steepness parameters as low as 0.05 and 0.02, due to the low efficiencies intrinsic to these short column lengths.

Diastereoselective construction of a functionalized dihydro-pyridazine-based spirooxindole scaffold via C-3 umpolung of isatin N,N′-cyclic azomethine imine

This study demonstrates an abnormal [3+3] tandem Michael addition/N-cyclization of isatin N,N′-cyclic azomethine imine 1,3-dipoles and 2-arylidene malononitrile that diastereoselectively construct a dihydro-pyridazine-based spirooxindole.

Alleviation of halitosis by use of probiotics and their protective mechanisms in the oral cavity

Regarding the relation of halitosis with oral infections and its effects on social relations between humans, the present study investigated the positive effects of probiotics on prevention or treatment of halitosis. The causative agents of halitosis are volatile sulphur compounds (VSCs), and halitosis is divided into oral and non-oral types according to the source of the VSCs. H2S and CH3SH are two main halitosis metabolites-produced following the degradation of proteins by bacteria in the mouth-however, CH3SCH3 has a non-oral origin, and is a blood neutral molecule. Just as much as halitosis is important in medicine, its psychological aspects are also considered, which can even lead to suicide. Today, the use of probiotics as a new therapeutic in many roles is in progress. Most probiotics are used for the treatment of gastrointestinal tract disorders, but various studies on the alleviation of halitosis by use of probiotics have reported satisfactory results. The genera Lactobacillus, Streptococcus and Weissella are among the most useful probiotics for the prevention or treatment of halitosis in the oral cavity.

Comparison of the sheath delivery system versus bare stenting for coronary stent implantation

Outside the United States, Palmaz-Schatz coronary stents are implanted by hand-crimping the stent to a high pressure balloon without the use of a protective sheath. This lowers the delivery profile, increases the ease of deployment, and ensures that the postdilatation balloon is centered on the stent. To assess this bare stenting technique, 209 patients were retrospectively analyzed: 92 patients (107 lesions) with the sheath protected stent delivery system (SDS) and 117 patients (150 lesions) with the bare stent approach. The number of balloons used per lesion in the bare stent group was significantly less than in the SDS group (1.9 +/- 0.6 vs. 3.8 +/- 1.2, P < 0.0001). In addition, the procedure time in the bare stent group was significantly shorter than in the SDS group (106 +/- 55 vs. 134 +/- 60 min, P = 0.001). There was no difference in frequency of adverse events or stent displacement during the procedure. The bare stenting technique decreases the procedure time, reduces the number of balloons used, and is as safe as the SDS approach.