Inhibition of agonist-induced down-regulation of the delta-opioid receptor with a proteasome inhibitor attenuates opioid tolerance in human embryonic kidney 293 cells

This study was designed to test the hypothesis that inhibition of agonist-induced delta-receptor down-regulation would block the development of opioid tolerance in a cell-based model. A human embryonic kidney 293 cell line was established that expressed an epitope-tagged delta-opioid receptor (DOR). Treatment of DOR cells with Tyr-d-Ala-Gly-Phe-d-Leu-enkephalin (DADL) resulted in a time-dependent decrease in the B(max) of delta-opioid receptor binding sites and immunoreactive receptor protein. When cells were coincubated with the proteasome inhibitor N-benzyloxycarbonyl-l-leucyl-l-leucyl-l-leucinal (ZLLL) and DADL, the magnitude of the agonist-induced decrease in B(max) and immunoreactive receptor protein was reduced compared with DADL treatment alone. Acute treatment of DOR cells with DADL caused a 3-fold increase in the level of phosphorylated mitogen-activated protein (MAP) kinase. Prior exposure of DOR cells to DADL completely abrogated the agonist-induced activation of MAP kinase. When DOR cells were coincubated with DADL and ZLLL, the proteasome inhibitor prevented the loss of agonist activation of MAP kinase. Acute treatment of DOR cell membranes with DADL stimulated [(35)S]guanosine 5'-3-O-(thio-)triphosphate (GTPgammaS) binding. When DOR cells were preincubated with DADL, the agonist-induced increase in [(35)S]GTPgammaS binding was attenuated. Coincubation of ZLLL and agonist partially prevented the decreased responsiveness to agonist stimulation. The results of this study demonstrated that inhibition of agonist-induced down regulation with a proteasome inhibitor attenuated opioid tolerance in a cellular model, and suggest that coadministration of a proteasome inhibitor with chronic opioid agonist treatment may be useful for limiting opioid tolerance in vivo.     

Molar bands for 'precision' bonding of lingual retainers

Bonded retainers have been used principally for long-term retention of treated cases. Various methods of bonding lingual retainers have been described in the literature over the past two decades. However, accurate and passive placement of retainers has always been a matter of concern. This report presents a simple and economical method for accurate and passive placement of bonded lingual retainers that enables the operator to save considerable chair time.     

Quantitative determination of bioactive phenylethanoid glycosides in Clerodendrum phlomidis using HPTLC

A new validated high performance thin layer chromatographic method has been developed for the simultaneous determination of three bioactive phenylethanoid glycosides verbascoside (1), leucosceptoside A (2) and martynoside (3) in the roots of Clerodendrum phlomidis. Extraction efficiency of marker compounds was studied using normal (cold and hot), ultrasonic as well as microwave assisted extraction techniques with various solvents. Well resolved separation of marker compounds was achieved on silica gel 60F₂₅₄ plates using the mobile phase consisting of chloroform–methanol–water (7.8:2.0:0.2, v/v/v). Quantitation of marker compounds was carried out using the densitometric reflection/absorption mode at 460 nm after post-chromatographic derivatization with vanillin–sulphuric acid reagent. Method was validated for peak purity, precision, robustness and sensitivity etc., as per ICH guidelines. Report on the occurrence of phenylethanoid glycosides for the first time in C. phlomidis is of chemotaxonomic importance.     

Practice patterns and adherence to nutrition guidelines in acute pancreatitis: An international physician survey

BackgroundThere is agreement among GI society guidelines for recommending early oral nutrition with non-liquid diet in patients with mild acute pancreatitis (AP). There is less agreement regarding administration of tube feedings (TF) in AP. Data on physicians’ adherence to nutrition guidelines and practice variations are limited.AimsTo report practice patterns in the nutritional management of different severity profiles of AP.MethodsWe conducted an anonymous electronic survey among physician members of the International Association of Pancreatology and the American Pancreatic Association. We assessed nutrition practices based on severity of AP, and asked relevant questions regarding the preferred administration strategies for enteral nutrition. Responses were compared by practice location and subspecialty.ResultsA total of 178 physicians, mostly medical pancreatologists (40.4%) and surgeons (34.8%) from Europe (43.4%) and North America (32%) responded. Overall, only 26.7% initiated oral nutrition in mild AP on day 1, 40.9% waited >48 h, and 57.3% initiated nutrition with liquid diets. Physicians reported frequently using TF in patients with moderately-severe (30–75%, depending on the amount and location of necrosis) and severe AP (75–80%). Two-thirds of physicians preferred initiating TF after 48 h, administering it post-pylorically, and using semi-elemental or polymeric formulas. Median TF duration was 11 days (IQR, 7–21). Significant variations were noted based on geographic location and physician subspecialty for several aspects of nutritional practices in both mild and non-mild AP.ConclusionAdherence to oral nutrition guideline recommendations for mild AP is low. There is significant variability in the use of TF in AP. Our study highlights opportunities for improving consistency of nutrition care in AP and identify potential areas for research.     

Microwave-assisted facile synthesis of poly(luminol-co-phenylenediamine) copolymers and their potential application in biomedical imaging

Conjugated copolymers have attracted much attention because of their outstanding photo-physical properties. The present work reports for the first time, microwave-assisted copolymerization of o-phenylenediamine with luminol using different weight ratios of the two monomers. The composition of the copolymers was confirmed by Fourier transform infrared spectroscopy (FTIR) and nuclear magnetic resonance spectroscopy (¹H-NMR) while monomer reactivity ratios were determined using the Fineman–Ross method. Ultraviolet-visible spectroscopy revealed the variation in polaronic states upon copolymerization while X-ray diffraction (XRD) and transmission electron microscopy (TEM) analyses showed the morphology of the copolymers to be intermediate between that of the homopolymers. Confocal analysis and fluorescence studies revealed that the copolymers showed composition based blue as well as red emission which could be utilized for in vivo imaging of cancer cells.

Development of bioimaging agents based on poly(o-phenylendiamine and luminol).     

Potential and Prospects of Shikonin Production Enhancement in Medicinal Plants

Proceedings of the National Academy of Sciences, India Section B: Biological Sciences - Plants are a rich source of valuable chemicals that are used as herbal and modern medicines. Shikonin, a...