61 research outputs found

    Inclusion Complex Of S(-) Bupivacaine And 2-hydroxypropyl- β-cyclodextrin: Study Of Morphology And Cytotoxicity

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    Local anesthetics (LA) belong to a class of pharmacological compounds that attenuate or eliminate pain by binding to the sodium channel of excitable membranes, blocking the influx of sodium ions and the propagation of the nerve impulse. S (-) bupivacaine (S(-) bvc) is a local anesthetic of amino-amide type, widely used in surgery and obstetrics for sustained peripheral and central nerve blockade. This article focuses on the characterization of an inclusion complex of S(-) bvc in 2-hydroxypropyl-β-cyclodextrin (HP-β-CD). Differential scanning calorimetry, scanning electron microscopy and X-Ray diffraction analysis showed structural changes in the complex. In preliminary toxicity studies, the cell viability tests revealed that the inclusion complex decreased the toxic effect (p<0.001) produced by S(-) bvc. These results suggest that the S(-) bvc:HP-β-CD inclusion complex represents a promising agent for the treatment of regional pain.273207212Araújo, D.R., Cereda, C.M., Brunetto, G.B., Pinto, L.M.A., Santana, M.H., de Paula, E., Encapsulation of mepivacaine prolongs the analgesia provided by sciatic nerve blockade in mice (2004) Can J Anaesth, 51, pp. 566-572Araújo, D.R., Fraceto, L.F., Braga, A.F.A., de Paula, E., Drug-delivery systems for racemic bupivacaine (S50-R50) and bupivacaine enantiomeric mixture (S75-R25):cyclodextrins complexation effects on sciatic nerve blockade in mice (2005) Rev Bras Anestesiol, 55, pp. 316-328Araújo, D.R., Moraes, C.M., Fraceto, L.F., Braga, A.F.A., de Paula, E., Cyclodextrin-bupivacaine enantiomeric mixture (S75-R25) inclusion complex and intrathecal anesthesia in rats (2006) Rev Bras Anestesiol, 56, pp. 495-506Bibby, D., Davies, N.M., Tueker, I.G., Mechanisms by which cyclodextrins modify drug release from polymeric drug delivery systems (2000) Int J Pharm, 197, pp. 1-11Covino, B.G., Vassalo, H.G., (1976) Local anesthetics: Mechanisms of action and clinical use, , New York: Grune and Stratton;, 255pFoster, R.H., Markham, A., Levobupivacaine. A review of its pharmacology and use as a local anaesthetic (2000) Drugs, 59, pp. 551-579Grant, G.J., Bansinath, M., Liposomal delivery systems for local anesthetics (2001) Reg Anesth Pain Med, 26, pp. 61-63Gristwood, R.W., Cardiac and CNS toxicity of levobupivacaine: Strengths of evidence for advantage over bupivacaine (2002) Drug Saf, 25, pp. 153-163Hirayama, F., Uekama, K., Cyclodextrin-based controlled drug release system (1999) Adv Drug Deliv Rev, 36, pp. 125-141Huang, Y.F., Pryor, M.E., Mather, L.E., Veering, B.T., Cardiovascular and central nervous system effects of intravenous S-bupivacaine and bupivacaine in sheep (1998) Anesth Analg, 86, pp. 797-804Jong, R.H., (1994) Local anesthetics, , Springfield: CC. Thomas;, 325pKohata, S., Jyodi, K., Ohyoshi, A., Thermal decomposition of cyclodextrins (α -, β-, γ, and modified β-CyD) and of metal-(β-CyD) complex in the solid phase (1993) Thermochim Acta, 217, pp. 187-198Loftsson, T., Brewster, M.E., Pharmaceutical application of Cyclodextrin. 1. Drug solubilization and stabilization (1996) J Pharm Sci, 85, pp. 1017-1025Loukas, Y.L., Vraka, V., Gregoriadis, G., Novel non-acidic formulations of haloperidol complexed with beta-cyclodextrin derivatives (1997) J Pharm Biomed Anal, 16, pp. 263-268Mather, L.E., McCall, P., McNicol, P.L., Bupivacaine enantiomer pharmacokinetics after intercostal neural blockade in liver transplant patients (1995) Anesth Analg, 80, pp. 328-335Michaud, M., Icart, S., Determination of the substitution of hydroxypropylbetadex using fourier transform infrared spectrophotometry (2001) PharmEuropa, 13, pp. 714-716Naidu, N.B., Chowdary, K.P.R., Murthy, K.V.R., Satyanarayana, V., Hayman, A.R., Becket, G., Physicochemical characterization and dissolution properties of meloxicam-cyclodextrin binary systems (2004) J Pharm Biomed Anal, 35, pp. 75-86Pinto, L.M.A., Fraceto, L.F., Santana, M.H.A., Pertinhez, T.A., Oyama, S., de Paula, E., Physico-chemical characterization of benzocaine-β-cyclodextrin inclusion complexes (2005) J Pharm Biomed Anal, 39, pp. 956-963Ren, X., Xue, Y., Liu, J., Zhang, K., Zheng, J., Lou, G., Gou, C., Shen, J., A novel cyclodextrin-deri ved tellurium compound with glutathione peroxidase (2002) Chembiochem, 3, pp. 363-365Rose, J.S., Neal, J.M., Kopacz, D.J., Extended-duration analgesia: Update on microspheres and liposomes (2005) Reg Anesth Pain Med, 30, pp. 275-285Strichartz, G.R., Ritchie, J.M., (1987) Local anesthetics: Handbook of experimental pharmacology, , Berlin: Springer-Verlag;, 445pThompson, D.O., Cyclodextrin-enabling excipients: Their present and future use in pharmaceuticals (1997) Crit Rev Ther Drug Carrier Syst, 14, pp. 1-10

    Whole-exome sequencing identifies SLC52A1 and ZNF106 variants as novel genetic risk factors for (early) multiple-organ failure in acute pancreatitis

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    Objective: The aim of this study was to identify genetic variants associated with early multiple organ failure (MOF) in acute pancreatitis.Summary background data: MOF is a life-threatening complication of acute pancreatitis, and risk factors are largely unknown, especially in early persistent MOF. Genetic risk factors are thought to enhance severity in complex diseases such as acute pancreatitis.Methods: A 2-phase study design was conducted. First, we exome sequenced 9 acute pancreatitis patients with early persistent MOF and 9 case-matched patients with mild edematous pancreatitis (phenotypic extremes) from our initial Dutch cohort of 387 patients. Secondly, 48 candidate variants that were overrepresented in MOF patients and 10 additional variants known from literature were genotyped in a replication cohort of 286 Dutch and German patients.Results: Exome sequencing resulted in 161,696 genetic variants, of which the 38,333 nonsynonymous variants were selected for downstream analyses. Of these, 153 variants were overrepresented in patients with multiple-organ failure, as compared with patients with mild acute pancreatitis. In total, 58 candidate variants were genotyped in the joined Dutch and German replication cohort. We found the rs12440118 variant of ZNF106 to be overrepresented in patients with MOF (minor allele frequency 20.4% vs 11.6%, Padj = 0.026). Additionally, SLC52A1 rs346821 was found to be overrepresented (minor allele frequency 48.0% vs 42.4%, Padj = 0.003) in early MOF. None of the variants known from literature were associated.Conclusions: This study indicates that SLC52A1, a riboflavin plasma membrane transporter, and ZNF106, a zinc finger protein, may be involved in disease progression toward (early) MOF in acute pancreatitis.Copyright © 2021 Wolters Kluwer Health, Inc. All rights reserved.Genetics of disease, diagnosis and treatmen

    Natural Course and Treatment of Pancreatic Exocrine Insufficiency in a Nationwide Cohort of Chronic Pancreatitis

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    Objectives Pancreatic exocrine insufficiency (PEI) is a common complication of chronic pancreatitis. However, little is known about the natural course of PEI and the effect of pancreatic enzyme replacement therapy on symptoms. The aim of this study was to evaluate the natural course and treatment of PEI in a nationwide cohort of patients with chronic pancreatitis. Methods Patients with chronic pancreatitis were selected from the multicenter Dutch Chronic Pancreatitis Registry. Patients were classified in 3 groups: Definite PEI, potential PEI, and no PEI. Definite PEI and no PEI were compared regarding the course of disease, symptoms, treatment, and quality of life. Results Nine hundred eighty-seven patients were included from 29 centers, of which 304 patients (31%) had definite PEI; 451 (46%), potentially PEI; and 232 (24%), no PEI. Patients with definite PEI had significantly more malabsorption symptoms, a lower body mass index, and aberrant defecation. Lowered quality of life was not independently associated with PEI. Of the PEI patients using pancreatic enzyme replacement therapy, 47% still reported steatorrhea. Conclusions Pancreatic exocrine insufficiency is associated with malabsorption symptoms and a lower body mass index. Some form of pancreatic enzyme replacement therapy is reasonably effective in alleviating malabsorption symptoms, but improvement of treatment is needed

    Development of pancreatic diseases during long-term follow-up after acute pancreatitis:a post-hoc analysis of a prospective multicenter cohort

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    Background and Aim: More insight into the incidence of and factors associated with progression following a first episode of acute pancreatitis (AP) would offer opportunities for improvements in disease management and patient counseling. Methods: A long-term post hoc analysis of a prospective cohort of patients with AP (2008–2015) was performed. Primary endpoints were recurrent acute pancreatitis (RAP), chronic pancreatitis (CP), and pancreatic cancer. Cumulative incidence calculations and risk analyses were performed. Results: Overall, 1184 patients with a median follow-up of 9 years (IQR: 7–11) were included. RAP and CP occurred in 301 patients (25%) and 72 patients (6%), with the highest incidences observed for alcoholic pancreatitis (40% and 22%). Pancreatic cancer was diagnosed in 14 patients (1%). Predictive factors for RAP were alcoholic and idiopathic pancreatitis (OR 2.70, 95% CI 1.51–4.82 and OR 2.06, 95% CI 1.40–3.02), and no pancreatic interventions (OR 1.82, 95% CI 1.10–3.01). Non-biliary etiology (alcohol: OR 5.24, 95% CI 1.94–14.16, idiopathic: OR 4.57, 95% CI 2.05–10.16, and other: OR 2.97, 95% CI 1.11–7.94), RAP (OR 4.93, 95% CI 2.84–8.58), prior pancreatic interventions (OR 3.10, 95% CI 1.20–8.02), smoking (OR 2.33, 95% CI 1.14–4.78), and male sex (OR 2.06, 95% CI 1.05–4.05) were independently associated with CP. Conclusion: Disease progression was observed in a quarter of pancreatitis patients. We identified several risk factors that may be helpful to devise personalized strategies with the intention to reduce the impact of disease progression in patients with AP.</p

    Structure and Function of the Hair Cell Ribbon Synapse

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    Faithful information transfer at the hair cell afferent synapse requires synaptic transmission to be both reliable and temporally precise. The release of neurotransmitter must exhibit both rapid on and off kinetics to accurately follow acoustic stimuli with a periodicity of 1 ms or less. To ensure such remarkable temporal fidelity, the cochlear hair cell afferent synapse undoubtedly relies on unique cellular and molecular specializations. While the electron microscopy hallmark of the hair cell afferent synapse — the electron-dense synaptic ribbon or synaptic body — has been recognized for decades, dissection of the synapse’s molecular make-up has only just begun. Recent cell physiology studies have added important insights into the synaptic mechanisms underlying fidelity and reliability of sound coding. The presence of the synaptic ribbon links afferent synapses of cochlear and vestibular hair cells to photoreceptors and bipolar neurons of the retina. This review focuses on major advances in understanding the hair cell afferent synapse molecular anatomy and function that have been achieved during the past years

    Overuse and misuse of antibiotics and the clinical consequence in necrotizing pancreatitis study: an observational multicenter

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    Objective: The use and impact of antibiotics and the impact of causative pathogens on clinical outcomes in a large real-world cohort covering the entire clinical spectrum of necrotizing pancreatitis remain unknown.Summary Background Data: International guidelines recommend broad-spectrum antibiotics in patients with suspected infected necrotizing pancreatitis. This recommendation is not based on high-level evidence and clinical effects are unknown.Materials and Methods: This study is a post-hoc analysis of a nationwide prospective cohort of 401 patients with necrotizing pancreatitis in 15 Dutch centers (2010-2019). Across the patient population from the time of admission to 6 months postadmission, multivariable regression analyses were used to analyze (1) microbiological cultures and (2) antibiotic use.Results: Antibiotics were started in 321/401 patients (80%) administered at a median of 5 days (P25-P75: 1-13) after admission. The median duration of antibiotics was 27 days (P25-P75: 15-48). In 221/321 patients (69%) infection was not proven by cultures at the time of initiation of antibiotics. Empirical antibiotics for infected necrosis provided insufficient coverage in 64/128 patients (50%) with a pancreatic culture. Prolonged antibiotic therapy was associated with Enterococcus infection (OR 1.08 [95% CI 1.03-1.16], P=0.01). Enterococcus infection was associated with new/persistent organ failure (OR 3.08 [95% CI 1.35-7.29], PP=0.03). Yeast was found in 30/147 cultures (20%).Discussion: In this nationwide study of patients with necrotizing pancreatitis, the vast majority received antibiotics, typically administered early in the disease course and without a proven infection. Empirical antibiotics were inappropriate based on pancreatic cultures in half the patients. Future clinical research and practice must consider antibiotic selective pressure due to prolonged therapy and coverage of Enterococcus and yeast. Improved guidelines on antimicrobial diagnostics and therapy could reduce inappropriate antibiotic use and improve clinical outcomes.Cellular mechanisms in basic and clinical gastroenterology and hepatolog

    Equilibrium solubility versus intrinsic dissolution: characterization of lamivudine, stavudine and zidovudine for BCS classification

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    Solubility and dissolution rate of drugs are of major importance in pre-formulation studies of pharmaceutical dosage forms. The solubility improvement allows the drugs to be potential biowaiver candidates and may be a good way to develop more dose-efficient formulations. Solubility behaviour of lamivudine, stavudine and zidovudine in individual solvents (under pH range of 1.2 to 7.5) was studied by equilibrium solubility and intrinsic dissolution methods. In solubility study by equilibrium method (shake-flask technique), known amounts of drug were added in each media until to reach saturation and the mixture was subjected to agitation of 150 rpm for 72 hours at 37 ºC. In intrinsic dissolution test, known amount of each drug was compressed in the matrix of Wood's apparatus and subjected to dissolution in each media with agitation of 50 rpm at 37 ºC. In solubility by equilibrium method, lamivudine and zidovudine can be considered as highly soluble drugs. Although stavudine present high solubility in pH 4.5, 6.8, 7.5 and water, the solubility determination in pH 1.2 was not possible due stability problems. Regarding to intrinsic dissolution, lamivudine and stavudine present high speed of dissolution. Considering a boundary value presented by Yu and colleagues (2004), all drugs studied present high solubility characteristics in intrinsic dissolution method. Based on the obtained results, intrinsic dissolution seems to be superior for solubility studies as an alternative method for biopharmaceutical classification purposes
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