368 research outputs found

    TOM-1/tomosyn acts with the UNC-6/netrin receptor UNC-5 to inhibit growth cone protrusion in Caenorhabditis elegans

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    In the polarity/protrusion model of growth cone repulsion from UNC-6/netrin, UNC-6 first polarizes the growth cone of the VD motor neuron axon via the UNC-5 receptor, and then regulates protrusion asymmetrically across the growth cone based on this polarity. UNC-6 stimulates protrusion dorsally through the UNC-40/DCC receptor, and inhibits protrusion ventrally through UNC-5, resulting in net dorsal growth. Previous studies showed that UNC-5 inhibits growth cone protrusion via the flavin monooxygenases and potential destabilization of F-actin, and via UNC-33/CRMP and restriction of microtubule plus-end entry into the growth cone. We show that UNC-5 inhibits protrusion through a third mechanism involving TOM-1/tomosyn. A short isoform of TOM-1 inhibited protrusion downstream of UNC-5, and a long isoform had a pro-protrusive role. TOM-1/tomosyn inhibits formation of the SNARE complex. We show that UNC-64/syntaxin is required for growth cone protrusion, consistent with a role of TOM-1 in inhibiting vesicle fusion. Our results are consistent with a model whereby UNC-5 utilizes TOM-1 to inhibit vesicle fusion, resulting in inhibited growth cone protrusion, possibly by preventing the growth cone plasma membrane addition required for protrusion

    Solution of the distributional equation and Green’s functions for scattering problems

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    AbstractA general method is described to obtain Green’s functions involved in nuclear scattering theory problems. By imposing specified boundary conditions on the general solution to the distribution equation, one can readily obtain the Green’s function for the radial Schrödinger equation

    THERMOSENSITIVE IN SITU GEL OF TINIDAZOLE IN TREATMENT OF BACTERIAL VAGINOSIS: FORMULATION AND EVALUATION

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    Bacterial Vaginosis (BV) is the leading cause of vaginal discharge. Because of its big surface area, wealthy blood supply, avoidance of the first-pass effect and high permeability to many drugs, the vagina offers a promising location for local impact as well as systemic drug delivery. In situ gels give several benefits, such as ease of administration in the respective body cavities, elevated spreadability at certain temperatures, reduced administration frequency, improved patient compliance and comfort compared to standard dosage forms. Tinidazole (TNZ) can give effective treatment over the BV. In situ gel of TNZ containing polaxomer 407 and HPMC E100 or carbopol 941NF was optimized on the basis of various evaluation parameters. Gelation temperature (Tgel) and pH of all batches was found in range of 36.6 to 38.0 ºC and 4.20 to 5.03, viscosity was found in range of 1100-2050 cps at 25ºC and 4800-6530 cps at 37ºC. The Spredability was found in range of 16-20 cm. From these evaluation parameters we selected best combination for the mucoadhesive property, antimicrobial study, in vitro drug release and for HET CAM irritation study. The optimized formulation gives satisfactory results. In this study we also compare the performance of two mucoadhesive polymer. Based on maximum desirability and cost effectiveness, in situ vaginal gel containing 20% polaxomer and 0.5% HPMC E100 could be considered as a highly promising treatment for bacterial vaginosis

    A short isoform of the UNC-6/Netrin receptor UNC-5 is required for growth cone polarity and robust growth cone protrusion in Caenorhabditis elegans

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    Introduction: UNC-6/Netrin is a conserved bi-functional guidance cue which regulates dorsal-ventral axon guidance in C. elegans. In the Polarity/Protrusion model of UNC-6/Netrin mediated dorsal growth away from UNC-6/Netrin, The UNC-5 receptor first polarizes the VD growth cone such that filopodial protrusions are biased dorsally. Based on this polarity, the UNC-40/DCC receptor stimulates growth cone lamellipodial and filopodial protrusion dorsally. The UNC-5 receptor maintains dorsal polarity of protrusion, and inhibits growth cone protrusion ventrally, resulting in net dorsal growth cone advance.Methods: Growth cone imaging in mutants, combined with Cas9 genome editing and genetic analysis, were used to analyze the role of a novel short isoform on unc-5 in growth cone polarity and protrusion.Results: Work presented here demonstrates a novel role of a previously undescribed, conserved short isoform of UNC-5 (UNC-5B). UNC-5B lacks the cytoplasmic domains of UNC-5 long, including the DEATH domain, the UPA/DB domain, and most of the ZU5 domain. Mutations that specifically affect only the unc-5 long isoforms were hypomorphic, suggesting a role of unc-5B short. A mutation specifically affecting unc-5B caused loss of dorsal polarity of protrusion and reduced growth cone filopodial protrusion, the opposite of unc-5 long mutations. Transgenic expression of unc-5B partially rescued unc-5 axon guidance defects, and resulted in large growth cones. Tyrosine 482 (Y482) in the cytoplasmic juxtamembrane region has been shown to be important for UNC-5 function, and is present in both UNC-5 long and UNC-5B short. Results reported here show that Y482 is required for the function of UNC-5 long and for some functions of UNC-5B short. Finally, genetic interactions with unc-40 and unc-6 suggest that UNC-5B short acts in parallel to UNC-6/Netrin to ensure robust growth cone lamellipodial protrusion.Discussion: These results demonstrate a previously-undescribed role for the UNC-5B short isoform, which is required for dorsal polarity of growth cone filopodial protrusion and to stimulate growth cone protrusion, in contrast to the previously-described role of UNC-5 long in inhibiting growth cone protrusion

    Anti-inflammatory and analgesic activity of different fractions of Boswellia serrata

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    The study was designed to investigate the anti-inflammatory and analgesic effect of different fractions of Boswellia serrata. The effect of different fractions of Boswellia serrata were studied using carrageenan induced paw edema, acetic acid induced writhing response, formalin induced pain, hot plate and tail flick method for studying anti-inflammatory and analgesic activity, respectively. The different fractions of B. serrata, essential oil (10 ml/kg), gum (100 mg/kg, resin (100 mg/kg) oleo-resin (100 mg/kg) and oleo-gum-resin (100 mg/kg) significantly reduces carrageenan induced inflammation in rats and shows analgesic activity, as determined by acetic acid induced writhing response, formalin induced pain, hot plate and tail flick method. The different fractions of B. serrata showed prompt anti-inflammatory and analgesic activity due to the inhibition of 5-lipoxygenase enzyme.Keywords: Analgesic; Boswellia serrata; Inflammation; 5- lipoxygenase; Burseraceae

    Zero Order Spectrophotometric Method for Estimation of Escitalopram Oxalate in Tablet Formulations

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    A new, simple, fast and reliable zero order spectrophotometric method has been developed for determination of Escitalopram Oxalate in bulk and tablet dosage forms. The quantitative determination of drug was carried out using the zero order values (absorbance) measured at 238 nm. Calibration graph constructed at 238 nm was linear in concentration range of 2-20 µg/ml with correlation coefficient 0.9999. The method was found to be precise, accurate, specific, and validated as per ICH guidelines and can be used for determination of Escitalopram Oxalate in tablet formulations

    SEPARATION OF BACOSIDE A 3 AND BACOPASIDE II, MAJOR TRITERPENOID SAPONINS IN Bacopa monnieri, BY HPTLC AND SFC. APPLICATION OF SFC IN IMPLEMENTATION OF UNIFORM DESIGN FOR HERBAL DRUG STANDARDIZATION, WITH THERMODYNAMIC STUDY

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    SUMMARY Development, optimization, and validation of new analytical methods for standardization of bacoside A 3 and bacopaside II, the major triterpenoid saponins present in Bacopa monnieri extract, are needed to improve the quality assurance of derived extracts and phytomedicines. Two chromatographic methods are described for evaluation of the quality of Bacopa monnieri extract and its commercial formulations. The first is reversed-phase high-performance thin-layer chromatography (RP-HPTLC), the second is packed column supercritical-fluid chromatography with photodiode-array detection (PC-SFC-DAD). SFC conditions were optimized by uniform design. The effect of temperature on the separation of the saponins was studied in detail. The Van't Hoff plots for retention and selectivity were found to be linear. To obtain a better understanding of the different separations, the temperature dependence was studied to determine the thermodynamic data ∆H°, ∆S°, ∆∆H° and ∆∆S°. These data revealed that separation of bacoside A 3 was enthalpically favoured in the range of temperatures investigated whereas entropy-controlled separation was observed for bacopaside II. Both methods were validated for precision, robustness, recovery, and limits of detection and quantitation. Analysis of variance (ANOVA) and Student's t-test were used to correlate results from quantitative determination of the markers by RP-HPTLC and PC-SFC-DAD. -126
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