Poly(2-Ethyl-2-Oxazoline) as an alternative to poly(Vinylpyrrolidone) in solid dispersions for solubility and dissolution rate enhancement of drugs

Poly(2-ethyl-2-oxazoline) (PEOX), a biocompatible polymer considered as pseudopolypeptide, was introduced as a potential alternative to the commonly used polymer, poly(vinylpyrrolidone) (PVP) for the preparation of solid dispersion with a poorly soluble drug. Glipizide (GPZ), a Biopharmaceutical Classification System class II model drug, was selected for solubility and dissolution rate study. GPZ-polymer solid dispersions and physical mixtures were characterized and investigated by X-ray diffractometry, differential scanning calorimetry, scanning electron microscopy, and FTIR spectroscopy. The impact of polymers on crystal nucleation kinetics was studied, and PEOX exhibited strong inhibitory effect compared with PVP. Solubility and dissolution behavior of the prepared solid dispersions and their physical blends were in vitro examined and evaluated. A significant enhancement in GPZ solubility was obtained with PEOX compared with the pure drug and solid dispersion with PVP. A big improvement in the intrinsic dissolution rate (45 times) and dissolved amount of GPZ (58 times) was achieved with PEOX in fasted state simulated intestinal fluid, against comparable enhancement observed with PEOX and PVP in phosphate buffer at pH 6.8. Lower molecular weight of PEOX-5K (5000 g/mol) was found to be superior to higher molecular weight PEOX-50K (50,000 g/mol) in the improvement of dissolution behavior. The findings of this study with GPZ as a model drug introduce lower molecular weight PEOX as a promising polymeric carrier toward better oral bioavailability of poorly soluble drugs

The 4q25 variant rs13143308T links risk of atrial fibrillation to defective calcium homoeostasis

Aims: Single nucleotide polymorphisms on chromosome 4q25 have been associated with risk of atrial fibrillation (AF) but the exiguous knowledge of the mechanistic links between these risk variants and underlying electrophysiological alterations hampers their clinical utility. Here, we tested the hypothesis that 4q25 risk variants cause alterations in the intracellular calcium homoeostasis that predispose to spontaneous electrical activity. Methods and results: Western blotting, confocal calcium imaging, and patch-clamp techniques were used to identify mechanisms linking the 4q25 risk variants rs2200733T and rs13143308T to defects in the calcium homoeostasis in human atrial myocytes. Our findings revealed that the rs13143308T variant was more frequent in patients with AF and that myocytes from carriers of this variant had a significantly higher density of calcium sparks (14.1¿±¿4.5 vs. 3.1¿±¿1.3 events/min, P¿=¿0.02), frequency of transient inward currents (ITI) (1.33¿±¿0.24 vs. 0.26¿±¿0.09 events/min, P¿<¿0.001) and incidence of spontaneous membrane depolarizations (1.22¿±¿0.26 vs. 0.56¿±¿0.17 events/min, P¿=¿0.001) than myocytes from patients with the normal rs13143308G variant. These alterations were linked to higher sarcoplasmic reticulum calcium loading (10.2¿±¿1.4 vs. 7.3¿±¿0.5¿amol/pF, P¿=¿0.01), SERCA2 expression (1.37¿±¿0.13 fold, P¿=¿0.03), and RyR2 phosphorylation at ser2808 (0.67¿±¿0.08 vs. 0.47¿±¿0.03, P¿=¿0.01) but not at ser2814 (0.28¿±¿0.14 vs. 0.31¿±¿0.14, P¿=¿0.61) in patients carrying the rs13143308T risk variant. Furthermore, the presence of a risk variant or AF independently increased the ITI frequency and the increase in the ITI frequency observed in carriers of the risk variants was exacerbated in those with AF. By contrast, the presence of a risk variant did not affect the amplitude or properties of the L-type calcium current in patients with or without AF. Conclusions: Here, we identify the 4q25 variant rs13143308T as a genetic risk marker for AF, specifically associated with excessive calcium release and spontaneous electrical activity linked to increased SERCA2 expression and RyR2 phosphorylation.Peer ReviewedPostprint (author's final draft

Cardiac electrical defects in progeroid mice and Hutchinson-Gilford progeria syndrome patients with nuclear lamina alterations

Hutchinson–Gilford progeria syndrome (HGPS) is a rare genetic disease caused by defective prelamin A processing, leading to nuclear lamina alterations, severe cardiovascular pathology, and premature death. Prelamin A alterations also occur in physiological aging. It remains unknown how defective prelamin A processing affects the cardiac rhythm. We show age-dependent cardiac repolarization abnormalities in HGPS patients that are also present in the Zmpste24-/- mouse model of HGPS. Challenge of Zmpste24-/- mice with the ß-adrenergic agonist isoproterenol did not trigger ventricular arrhythmia but caused bradycardia-related premature ventricular complexes and slow-rate polymorphic ventricular rhythms during recovery. Patch-clamping in Zmpste24-/- cardiomyocytes revealed prolonged calcium-transient duration and reduced sarcoplasmic reticulum calcium loading and release, consistent with the absence of isoproterenol-induced ventricular arrhythmia. Zmpste24-/- progeroid mice also developed severe fibrosis-unrelated bradycardia and PQ interval and QRS complex prolongation. These conduction defects were accompanied by overt mislocalization of the gap junction protein connexin43 (Cx43). Remarkably, Cx43 mislocalization was also evident in autopsied left ventricle tissue from HGPS patients, suggesting intercellular connectivity alterations at late stages of the disease. The similarities between HGPS patients and progeroid mice reported here strongly suggest that defective cardiac repolarization and cardiomyocyte connectivity are important abnormalities in the HGPS pathogenesis that increase the risk of arrhythmia and premature death.Peer ReviewedPostprint (published version

Synthesis and applications of 2(1H)-pyrazinones

Les 2(1H)-pirazinones són presents en una gran varietat de productes naturals. A més, la seva preparació constitueix una etapa clau en la síntesi d’un gran nombre de compostos bioactius. En aquest article es revisen dos dels mètodes principals de síntesi de 2(1H)-pirazinones a partir de precursors acíclics: la condensació d’un α-aminoàcid amida amb un compost 1,2-dicarbonílic i la reacció entre un halur d’oxalil i un α-aminonitril. Aquest darrer mètode condueix a la formació de 3,5-dihalo-2(1H)-pirazinones que serveixen de base per a l’obtenció de pirazinones altament funcionalitzades.2(1H)-pyrazinones are present in a wide variety of natural products. In addition, their preparation constitutes a key step in the synthesis of numerous bioactive compounds. This article reviews two of the main methods for the synthesis of 2(1H)-pyrazinones from acyclic precursors: the condensation of an α-amino acid amide with a 1,2-dicarbonyl compound and the reaction between an oxalyl halide and an α-aminonitrile. This last method leads to the formation of 3,5-dihalo-2(1H)-pyrazinones which serve as a basis for obtaining highly functionalized pyrazinones

The 4q25 variant rs13143308T links risk of atrial fibrillation to defective calcium homeostasis

Aims: Single nucleotide polymorphisms on chromosome 4q25 have been associated with risk of atrial fibrillation (AF) but the exiguous knowledge of the mechanistic links between these risk variants and underlying electrophysiological alterations hampers their clinical utility. Here, we here tested the hypothesis that 4q25 risk variants cause alterations in the intracellular calcium homeostasis that predispose to spontaneous electrical activity. Methods and results: Western blotting, confocal calcium imaging, and patch-clamp techniques were used to identify mechanisms linking the 4q25 risk variants rs2200733T and rs13143308T to defects in the calcium homeostasis in human atrial myocytes. Our findings revealed that the rs13143308T variant was more frequent in patients with AF and that myocytes from carriers of this variant had a significantly higher density of calcium sparks (14.1±4.5 vs. 3.1±1.3 events/min, p¿=¿0.02), frequency of transient inward (ITI) currents (1.33±0.24 vs. 0.26±0.09 events/min, p¿<¿0.001) and incidence of spontaneous membrane depolarizations (1.22±0.26 vs. 0.56±0.17 events/min, p¿=¿0.001) than myocytes from patients with the normal rs13143308G variant. These alterations were linked to higher sarcoplasmic reticulum calcium loading (10.2±1.4 vs. 7.3±0.5amol/pF, p¿=¿0.01), SERCA2 expression (1.37±0.13 fold, p¿=¿0.03) and RyR2 phosphorylation at s2808 (0.67±0.08 vs. 0.47±0.03, p¿=¿0.01) but not at s2814 (0.28±0.14 vs. 0.31±0.14, p¿=¿0.61) in patients carrying the rs13143308T risk variant. Furthermore, the presence of a risk variant or AF independently increased the ITI frequency and the increase in the ITI frequency observed in carriers of the risk variants was exacerbated in those with AF. By contrast, the presence of a risk variant did not affect the amplitude or properties of the L-type calcium current in patients with or without AF. Conclusions: We here identify the 4q25 variant rs13143308T as a genetic risk marker for AF, specifically associated with excessive calcium release and spontaneous electrical activity linked to increased SERCA2 expression and RyR2 phosphorylationThis work was supported by multi-centric grants from Centro Nacional de Investigaciones Cardiovasculares [CNIC-2009-08 to L.H.-M. and D.F.]; a grant from Fundacio´ Marato´ TV3 [2015-20-30 to L.H.-M.]; and grants from the Spanish Ministry of Economy and Competition [SAF2014-58286-C2-1-R to L.H.-M.] and [DPI2013-44584-R to R.B.]; and from the Spanish Ministry of Health and Consume, Instituto de Salud Carlos III, Red de Investigacio´n Cardiovascular [RD12/0042/0002] and CIBERCV to J.C., and from Fondo Europeo de Desarrollo Regional (FEDER)

Factors Associated to Duration of Hepatitis A Outbreaks: Implications for Control

Even though hepatitis A mass vaccination effectiveness is high, outbreaks continue to occur. The aim of this study was to investigate the association between duration and characteristics of hepatitis A outbreaks. Hepatitis A (HA) outbreaks reported between 1991 and 2007 were studied. An outbreak was defined as ≥2 epidemiologically-linked cases with ≥1 case laboratory-confirmed by detection of HA immunoglobulin M (IgM) antibodies. Relationships between explanatory variables and outbreak duration were assessed by logistic regression. During the study period, 268 outbreaks (rate 2.45 per million persons-year) and 1396 cases (rate 1.28 per 105 persons-year) were reported. Factors associated with shorter duration were time to intervention (OR = 0.96; 95% CI: 0.94–0.98) and school setting (OR = 0.39; 95% CI: 0.16–0.92). In person-to-person transmission outbreaks only time to intervention was associated with shorter outbreak duration (OR = 0.96; 95% CI: 0.95–0.98). The only variables associated with shorter outbreak duration were early administration of IG or vaccine and a school setting. Timely reporting HA outbreaks was associated with outbreak duration. Making confirmed HA infections statutory reportable for clinical laboratories could diminish outbreak duration

Evaluation of different bowel preparations for small bowel capsule endoscopy: a prospective, randomized, controlled study

To obtain an adequate view of the whole small intestine during capsule endoscopy (CE) a clear liquid diet and overnight fasting is recommended. However, intestinal content can hamper vision in spite of these measures. Our aim was to evaluate tolerance and degree of intestinal cleanliness during CE following three types of bowel preparation. PATIENTS AND METHODS: This was a prospective, multicenter, randomized, controlled study. Two-hundred ninety-one patients underwent one of the following preparations: 4 L of clear liquids (CL) (group A; 92 patients); 90 mL of aqueous sodium phosphate (group B; 89 patients); or 4 L of a polyethylene glycol electrolyte solution (group C; 92 patients). The degree of cleanliness of the small bowel was classified by blinded examiners according to four categories (excellent, good, fair or poor). The degree of patient satisfaction, gastric and small bowel transit times, and diagnostic yield were measured. RESULTS: The degree of cleanliness did not differ significantly between the groups (P = 0.496). Interobserver concordance was fair (k = 0.38). No significant differences were detected between the diagnostic yields of the CE (P = 0.601). Gastric transit time was 35.7 +/- 3.7 min (group A), 46.1 +/- 8.6 min (group B) and 34.6 +/- 5.0 min (group C) (P = 0.417). Small-intestinal transit time was 276.9 +/- 10.7 min (group A), 249.7 +/- 13.1 min (group B) and 245.6 +/- 11.6 min (group C) (P = 0.120). CL was the best tolerated preparation. Compliance with the bowel preparation regimen was lowest in group C (P = 0.008). CONCLUSIONS: A clear liquid diet and overnight fasting is sufficient to achieve an adequate level of cleanliness and is better tolerated by patients than other forms of preparation

Health Services Utilization, Work Absenteeism and Costs of Pandemic Influenza A (H1N1) 2009 in Spain: A Multicenter-Longitudinal Study

Background: The aim of this study was to estimate healthcare resource utilization, work absenteeism and cost per patient with pandemic influenza (H1N1)2009, from its beginning to March 2010, in Spain. We also estimated the economic impact on healthcare services. Methods and Findings: Longitudinal, descriptive,multicenter study of in- and outpatients with confirmed diagnosis of influenza A (H1N1) in Spain. Temporal distribution of cases was comparable to that in Spain. Information of healthcare and social resources used from one week before admission (inpatient) or index-medical visit (outpatient) until recovery was gathered. Unit cost was imputed to utilization frequency for the monetary valuation of use. Mean cost per patient was calculated. A sensitivity analysis was conducted, and variables correlated with cost per patient were identified. Economic impact on the healthcare system was estimated using healthcare costs per patient and both, the reported number of confirmed and clinical cases in Spain. 172 inpatients and 224 outpatients were included. Less than 10% were over 65 years old and more than 50% had previous comorbidities. 12.8% of inpatients were admitted to the Intensive Care Unit. Mean length of hospital stay of patients not requiring critical care was 5 days (SD =4.4). All working-inpatients and 91.7% working-outpatients went on sick leave. On average, work absenteeism was 30.5 days (SD=20.7) for the first ones and 9 days (SD= 6.3) for the latest. Caregivers of 21.7% of inpatients and 8.5% of outpatients also had work absenteeism during 10.7 and 4.1 days on average respectively. Mean cost was J6,236/inpatient (CI95%=1,384-14,623) and J940/outpatient (CI95% =66-3,064). The healthcare economic burden of patients with confirmed influenza was J144,773,577 (IC95% 13,753,043-383,467,535). More than 86% of expenditures were a result of outpatients" utilization. Conclusion: Cost per H1N1-patient did not defer much from seasonal influenza estimates. Hospitalizations and work absenteeism represented the highest cost per patient

Successful treatment of Candida parapsilosis mural endocarditis with combined caspofungin and voriconazole

BACKGROUND: Fungal mural endocarditis is a rare entity in which the antemortem diagnosis is seldom made. Seven cases of mural endocarditis caused by Candida spp. have been collected from literature and six of these patients died after treatment with amphotericin B. CASE PRESENTATION: We report a case of mural endocarditis diagnosed by transesophageal echocardiogram and positive blood cultures to Candida parapsilosis. Because blood cultures continued to yield C. parapsilosis despite caspofungin monotherapy, treatment with voriconazole was added. CONCLUSION: This is the first description of successful treatment of C. parapsilosis mural endocarditis with caspofungin and voriconazole