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Enzyme Release (enzyme + release)
Selected AbstractsDoes l -carnitine have any effect on cold preservation injury of non-fatty liver in the University of Wisconsin solution?HEPATOLOGY RESEARCH, Issue 8 2007Abdurrahman Coskun Aim:, To evaluate the protective effect of l -carnitine on liver tissue preserved in University of Wisconsin (UW) solution. Methods:, Twenty Wistar Albino rats were divided into two groups, a control (UW) group and a UW plus l -carnitine group. Retrieved liver grafts were preserved in UW and UW plus l -carnitine solutions at +4°C. Preservation solution samples were assessed at 2, 24, 36, and 48 h to measure alanine aminotransferase and acid phosphatase activity. Tissue injury was scored on paraffin sections. Results:, No micro or macrovacuolar fat droplets were observed in the tissue slices. l -Carnitine effectively decreased enzyme release when added to UW solution (P < 0.05). Conclusion:, In addition to fatty liver, l -carnitine might be a metabolic adjunct in preservation solutions for non-fatty liver within UW solution. [source] Inflammatory Cytokine Imbalance after Coronary Angioplasty: Links with Coronary AtherosclerosisJOURNAL OF INTERVENTIONAL CARDIOLOGY, Issue 4 2007NATALE DANIELE BRUNETTI M.D., Ph.D. Aim:To investigate release of some inflammatory cytokines (Cys) after coronary angioplasty and its links with coronary atherosclerosis. Methods:Twenty-seven consecutive subjects with acute coronary syndrome (ACS) who underwent percutaneous coronary intervention (PCI) were enrolled in the study: serial blood samples were taken in order to evaluate plasma concentrations of Interleukin (IL)-2, IL-10, IL-18, TNF,, and IFN, just before PCI at 12 and 24 hours. Patients were then divided, considering balance between each inflammatory Cy and IL-10, an antiinflammatory Cy, into four groups, ranging from a prevalent antiinflammatory response (stable inflammatory Cy,increasing IL-10 values) to a marked inflammatory imbalance (increasing inflammatory Cy,stable IL-10 values). Results:All Cys showed significant increases in plasma concentrations if compared with baseline values. Release curves were not significantly different when comparing subjects with ST-elevation myocardial infarction (STEMI) versus unstable angina,non-STEMI (UA-NSTEMI), diabetics versus controls. Subjects with marked inflammatory response showed a higher incidence of stenosis on left anterior descending (LAD) coronary artery (IL-2 ,2 and IFN, P < 0.05); Cy release was higher in patients with multivessel coronary disease (IL-2 and IFN,, ANOVA P < 0.01). Correlations were also referable between Cys and myocardial enzyme release. Subjects treated with sirolimus-eluting stents (SES) showed significantly lower Cy periprocedure ratio if compared with those treated with bare metal stents. Conclusions:A significant Cy release is detectable after PCI: inflammatory response seems to correlate with both PCI due to plaque instabilization and coronary atherosclerosis. A blunted inflammatory response is detectable in subjects treated with SES. [source] Physicochemical characterization of papain entrapped in ionotropically cross-linked kappa-carrageenan gel beads for stability improvement using Doehlert shell designJOURNAL OF PHARMACEUTICAL SCIENCES, Issue 9 2006Mayur G. Sankalia Abstract This work examines the influence of various process parameters on papain entrapped in cross-linked ,-carrageenan beads for improvement of its stability. A Doehlert shell design (DSD) was employed to investigate the effect of three process variables, namely ,-carrageenan concentration, KCl concentration, and hardening time, on the entrapment, time required for 50% enzyme release (T50), time required for 90% enzyme release (T90), and particle size. The beads were prepared by dropping the ,-carrageenan containing papain into a magnetically stirred KCl solution. Topographical characterization was carried out by scanning electron microscopy and entrapment was confirmed by Fourier transform infrared spectroscopy and differential scanning calorimetry. Stability testing was carried out according to the International Conference on Harmonization (ICH) guidelines for zone III and IV. A polymeric matrix was prepared with ,-carrageenan (3.5% w/v) and potassium chloride (0.5 M) using the ionotropic gelation method, with a hardening time of 20 min. Beads characterized by a spherical disc shape with a collapsed center, an absence of aggregates, an entrapment of 82.75%, a T90 value of 55.36 min, and a composite index of 88.55 were produced. The shelf-life of the enzyme-loaded beads was found to increase to 3.63 years compared with 1.01 years for the conventional formulation. It can be inferred that the proposed methodology can be used to prepare papain-loaded ,-carrageenan beads for stability improvement. © 2006 Wiley-Liss, Inc. and the American Pharmacists Association J Pharm Sci 95: 1994,2013, 2006 [source] In vitro comparative study of three pancreatic enzyme preparations: dissolution profiles, active enzyme release and acid stabilityALIMENTARY PHARMACOLOGY & THERAPEUTICS, Issue 3 2008A. ALOULOU Summary Background, Various pancreatic enzyme preparations are used for the treatment of pancreatic insufficiency but their bioequivalence is often unknown. Aim, To determine in vitro the pH-dependent release and acid resistance of enzymes from three commercially available pancreatin capsules, two containing enteric-coated (Creon 25000; Eurobiol 25000) and one uncoated (Eurobiol 12500) microspheres. Methods, Dissolution experiments were performed at pH values ranging from 4.0 to 5.8. Lipase, chymotrypsin and amylase activities were measured in the solution as a function of time. Results, Eurobiol 25000 started to release its enzymes significantly at pH 5.0 (t1/2 = 71 min), whereas the enzymes from Creon 25000 were only released at higher pH value (5.4; t1/2 = 49.2 min). Unlike chymotrypsin, lipase and amylase were highly sensitive to acidic conditions at the lowest pH values tested. Both enzymes were also found to be sensitive to proteolytic inactivation at the highest pH values tested. Overall, Eurobiol 25000 released higher amounts of active amylase and lipase than Creon 25000 at the pH values usually found in duodenal contents. The uncoated Eurobiol 12500 preparation was, however, the only one that could immediately release rather high levels of active chymotrypsin and lipase at low pH (4.5). Conclusion, These findings suggest that pH-sensitive enteric-coated pancreatin products containing similar amounts of enzymes might not be bioequivalent depending on the pH of duodenal contents. [source] Control of the release of digestive enzymes in the larvae of the fall armyworm, Spodoptera frugiperdaARCHIVES OF INSECT BIOCHEMISTRY AND PHYSIOLOGY (ELECTRONIC), Issue 1 2010Digali Lwalaba Abstract There is a basal level of enzyme activity for trypsin, aminopeptidase, amylase, and lipase in the gut of unfed larval (L6) Spodoptera frugiperda. Trypsin activity does not decrease with non-feeding, possibly because of the low protein levels in plants along with high amino acid requirements for growth and storage (for later reproduction in adults). Therefore, trypsin must always be present so that only a minimal protein loss via egestion occurs. Larvae, however, adjust amylase activity to carbohydrate ingestion, and indeed amylase activity is five-fold higher in fed larvae compared to unfed larvae. Gut lipase activity is low, typical of insects with a high carbohydrate diet. A flat-sheet preparation of the ventriculus was used to measure the release of enzymes in response to specific nutrients and known brain/gut hormones in S. frugiperda. Sugars greatly increase (>300%) amylase release, but starch has no effect. Proteins and amino acids have little or no effect on trypsin or aminopeptidase release. The control of enzyme release in response to food is likely mediated through neurohormones. Indeed, an allatostatin (Spofr-AS A5) inhibits amylase and trypsin, and allatotropin (Manse- AT) stimulates amylase and trypsin release. Spofr-AS A5 also inhibits ileum myoactivity and Manse-AT stimulates myoactivity. The epithelial secretion rate of amylase and trypsin was about 20% of the amount of enzyme present in the ventricular lumen, which, considering the efficient counter-current recycling of enzymes, suggests that the secretion rate is adequate to replace egested enzymes. © 2009 Wiley Periodicals, Inc. [source] Effects of Cryopreservation and Hypothermic Storage on Cell Viability and Enzyme Activity in Recombinant Encapsulated Cells Overexpressing Alpha-L-IduronidaseARTIFICIAL ORGANS, Issue 5 2010Fabiana Quoos Mayer Abstract Here, we show the effects of cryopreservation and hypothermic storage upon cell viability and enzyme release in alginate beads containing baby hamster kidney cells overexpressing alpha-L-iduronidase (IDUA), the enzyme deficient in mucopolysaccharidosis type I. In addition, we compared two different concentrations of alginate gel (1% and 1.5%) in respect to enzyme release from the beads and their shape and integrity. Our results indicate that in both alginate concentrations, the enzyme is released in lower amounts compared with nonencapsulated cells. Alginate 1% beads presented increased levels of IDUA release, although this group presented more deformities when compared with alginate 1.5% beads. Importantly, both encapsulated groups presented higher cell viability after long cryopreservation period and hypothermic storage. In addition, alginate 1.5% beads presented higher enzyme release after freezing protocols. Taken together, our findings suggest a benefic effect of alginate upon cell viability and functionality. These results may have important application for treatment of both genetic and nongenetic diseases using microencapsulation-based artificial organs. [source] Perfusate Lactate Dehydrogenase Level and Intrarenal Resistance Could Not Be Adequate Markers of Perfusion Quality During Isolated Kidney PerfusionARTIFICIAL ORGANS, Issue 11 2000Berta Herrera Abstract: The main goal of this work was to study the influence of perfusion pressure and flow waveform during kidney perfusion, and the relationship between renal vascular resistance (RVR) and lactate dehydrogenase (LDH) concentration in the perfusate. Simultaneous constant pressure kidney perfusions were performed with either pulsatile or continuous flow at either 30 or 80 mm Hg of constant perfusion pressure. Mean flow, pressure, and RVR were displayed online during perfusion. Perfusate samples for LDH, creatine phosphatase kinase (CPK), and alkaline phosphatase (AP) determinations were taken. At the end of the perfusion, 2 ml of Evans blue was injected into the circuit to obtain images of perfusate distribution, and the kidneys were weighed. Also, hematoxylin/eosine studies were performed, showing more Bowman's space and tubular dilation in kidneys perfused with high pressure. We did not find differences in RVR between kidneys perfused at 30 and 80 mm Hg; nevertheless, perfusate distribution was better in the 80 mm Hg perfusions. We did not find any correlation between enzyme release and RVR in kidneys perfused with different mean pressures. These findings suggest that vascular resistance and LDH concentration cannot be independently considered as adequate markers of perfusate distribution. [source] Calcium sensing and cell signaling processes in the local regulation of osteoclastic bone resorptionBIOLOGICAL REVIEWS, Issue 1 2004Mone Zaidi ABSTRACT The skeletal matrix in terrestrial vertebrates undergoes continual cycles of removal and replacement in the processes of bone growth, repair and remodeling. The osteoclast is uniquely important in bone resorption and thus is implicated in the pathogenesis of clinically important bone and joint diseases. Activated osteoclasts form a resorptive hemivacuole with the bone surface into which they release both acid and osteoclastic lysosomal hydrolases. This article reviews cell physiological studies of the local mechanisms that regulate the resorptive process. These used in vitro methods for the isolation, culture and direct study of the properties of neonatal rat osteoclasts. They demonstrated that both local microvascular agents and products of the bone resorptive process such as ambient Ca2+ could complement longer-range systemic regulatory mechanisms such as those that might be exerted through calcitonin (CT). Thus elevated extracellular [Ca2+], or applications of surrogate divalent cation agonists for Ca2+, inhibited bone resorptive activity and produced parallel increases in cytosolic [Ca2+], cell retraction and longer-term inhibition of enzyme release in isolated rat osteoclasts. These changes showed specificity, inactivation, and voltage-dependent properties that implicated a cell surface Ca2+ receptor (CaR) sensitive to millimolar extracellular [Ca2+]. Pharmacological, biophysical and immunochemical evidence implicated a ryanodine-receptor (RyR) type II isoform in this process and localized it to a unique, surface membrane site, with an outward-facing channel-forming domain. Such a surface RyR might function either directly or indirectly in the process of extracellular [Ca2+] sensing and in turn be modulated by cyclic adenosine diphosphate ribose (cADPr) produced by the ADP-ribosyl cyclase, CD38. The review finishes by speculating about possible detailed models for these transduction events and their possible interactions with other systemic mechanisms involved in Ca2+ homeostasis as well as the possible role of the RyR-based signaling mechanisms in longer-term cell regulatory processes. [source] | |||||||||||||