149 research outputs found

    I. Hydrodynamic model selection for counter diffusing systems: A selectivity study in mass transfer with non-linear chemical kinetics. II. Effect of catalyst poisoning on selectivity: A modelless approach. III. Selectivity optimisation for complex non-linear reaction schemes. IV. Reactor simulation for the hydrogen fluoride reaction: Fluorspar + sulphuric acid products

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    A two step non-linear complex reaction scheme 2M1→2M2→M3 has been used to establish the need for a careful selection of a mass transfer model for counter diffusing systems. By comparing the Penetration Theory and Film Theory selectivity parameters, it is shown that the two fluid-mechanical models do not predict the same results. It is also shown that the deviations between the results predicted by the two models do not appear to be directly related to increasing complexity in the reaction kinectics. In addition, the effect of reaction order on the selectivity parameter, has been examined by varying the order of the second step reaction

    Traumatic Cyclodialysis Cleft Surgical Management Using Encirclage and Cryotherapy : A Novel Approach

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    This is a retrospective case series of 4 patients with traumatic cyclodialysis cleft (CC) with features of hypotony and posterior segment manifestations of blunt trauma who were treated using encirclage and trans scleral cryoptherapy along with vitrectomy. Encirclage was placed anteriorly in order to support the cleft. There was closure of cleft and improvement in Intra ocular pressure (IOP) in all cases. Thus the identification and treatment of CC with encirclage in cases with varied posterior manifestation of trauma can lead to good anatomical and visual restoration

    Management of necrotizing myositis in a field hospital: a case report

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    Necrotizing myositis is a rare and fatal disease of skeletal muscles caused by group A beta hemolytic streptococci (GABHS). Its early detection by advanced imaging forms the basis of current management strategy. Paucity of advanced imaging in field/rural hospitals necessitates adoption of management strategy excluding imaging as its basis. Such a protocol, based on our experience and literature, constitutes

    Human SHPRH suppresses genomic instability through proliferating cell nuclear antigen polyubiquitination

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    Differential modifications of proliferating cell nuclear antigen (PCNA) determine DNA repair pathways at stalled replication forks. In yeast, PCNA monoubiquitination by the ubiquitin ligase (E3) yRad18 promotes translesion synthesis (TLS), whereas the lysine-63–linked polyubiquitination of PCNA by yRad5 (E3) promotes the error-free mode of bypass. The yRad5-dependent pathway is important to prevent genomic instability during replication, although its exact molecular mechanism is poorly understood. This mechanism has remained totally elusive in mammals because of the lack of apparent RAD5 homologues. We report that a putative tumor suppressor gene, SHPRH, is a human orthologue of yeast RAD5. SHPRH associates with PCNA, RAD18, and the ubiquitin-conjugating enzyme UBC13 (E2) and promotes methyl methanesulfonate (MMS)–induced PCNA polyubiquitination. The reduction of SHPRH by stable short hairpin RNA increases sensitivity to MMS and enhances genomic instability. Therefore, the yRad5/SHPRH-dependent pathway is a conserved and fundamental DNA repair mechanism that protects the genome from genotoxic stress

    Implementation and characterization of solvent detergent viral inactivation in Single Use bags

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    Biomanufacturing of recombinant products from mammalian cell culture systems and plasma derived products requires at least two orthogonal virus reduction steps to comply with regulatory pathogen safety risk mitigation guidelines. Solvent detergent viral inactivation (SD VI) has historically been effectively utilized for the inactivation of lipid-enveloped viruses from plasma derived products, yet only recently have process development activities focused on implementation of SD VI in single use systems. The adoption of single-use technologies for bioproduction continues to progress, driven predominantly by the benefits of operational flexibility, speed of implementation, lower capital investment, and elimination of cross contamination concerns. However, the suitability of this flexible production platform for SD VI remains to be fully characterized. This presentation will review data generated from a recently completed SD VI study on a single-use mixing platform that demonstrates successful performance of this operation in a flexible manufacturing environment. Specifically, chemical compatibility, non-specific chemical adsorption, and leachables profiles of the reagents used in SD VI with the container film, mixer components, and transfer assemblies will be reviewed. In addition, the effectiveness of SD VI in single-use bags, based on small scale virus spiking studies, will be presented. Best practices guidance for appropriate unit operation set up, connectology, mixing and operation from 50 to 500L scale will also be reviewed. Finally, the potential regulatory impact of the implementation of single-use technology on solvent/detergent viral inactivation, based on the observations from this study, will be discussed

    Transient knockdown and overexpression reveal a developmental role for the zebrafish enosf1b gene

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    <p>Abstract</p> <p>Background</p> <p>Despite detailed <it>in vivo </it>knowledge of glycolytic enolases and many bacterial non-enolase members of the superfamily, little is known about the <it>in vivo </it>function of vertebrate non-enolase enolase superfamily members (ENOSF1s). Results of previous studies suggest involvement of the β splice form of ENOSF1 in breast and colon cancers. This study used the zebrafish (<it>Danio rerio</it>) as a vertebrate model of ENOSF1β function.</p> <p>Results</p> <p>Whole mount in situ hybridization (WISH) showed that zebrafish ENOSF1β (<it>enosf1b</it>) is zygotic and expressed ubiquitously through the first 24 hours post fertilization (hpf). After 24 hpf, <it>enosf1b </it>expression is restricted to the notochord. Embryos injected with <it>enosf1b</it>-EGFP mRNA grew slower than EGFP mRNA-injected embryos but caught up to the EGFP-injected embryos by 48 hpf. Embryos injected with ATG or exon 10 <it>enosf1b </it>mRNA-targeting morpholinos had kinked notochords, shortened anterior-posterior axes, and circulatory edema. WISH for <it>ntl </it>or <it>pax2a </it>expression showed that embryos injected with either morpholino have deformed notochord and pronephros. TUNEL staining revealed increased apoptosis in the peri-notochord region.</p> <p>Conclusions</p> <p>This study is the first report of ENOSF1 function in a vertebrate and shows that ENOSF1 is required for embryonic development. Increased apoptosis following <it>enosf1b </it>knockdown suggests a potential survival advantage for increased ENOSF1β expression in human cancers.</p

    Knockdown of Bardet-Biedl Syndrome Gene BBS9/PTHB1 Leads to Cilia Defects

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    Bardet-Biedl Syndrome (BBS, MIM#209900) is a genetically heterogeneous disorder with pleiotropic phenotypes that include retinopathy, mental retardation, obesity and renal abnormalities. Of the 15 genes identified so far, seven encode core proteins that form a stable complex called BBSome, which is implicated in trafficking of proteins to cilia. Though BBS9 (also known as PTHB1) is reportedly a component of BBSome, its direct function has not yet been elucidated. Using zebrafish as a model, we show that knockdown of bbs9 with specific antisense morpholinos leads to developmental abnormalities in retina and brain including hydrocephaly that are consistent with the core phenotypes observed in syndromic ciliopathies. Knockdown of bbs9 also causes reduced number and length of cilia in Kupffer's vesicle. We also demonstrate that an orthologous human BBS9 mRNA, but not one carrying a missense mutation identified in BBS patients, can rescue the bbs9 morphant phenotype. Consistent with these findings, knockdown of Bbs9 in mouse IMCD3 cells results in the absence of cilia. Our studies suggest a key conserved role of BBS9 in biogenesis and/or function of cilia in zebrafish and mammals

    Antioxidant, anti-inflammatory and analgesic potential of Cucumis sativus seed extract

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    In the present study antioxidant, anti-inflammatory and analgesic potential of the methanolic extract of Cucumis sativus seeds was evaluated. Extraction of the seeds was carried out using solvents of increasing polarity. The free radical scavenging activity of all the extracts was measured by DPPH and H2O2 methods. Methanolic extract of the seeds had shown significant antioxidant activity as compared to chloroform and ethyl acetate extract. Hence, methanolic extract of C. sativus seeds (MECS) at a dose level of 100, 200 and 300 mg/kg was further evaluated for its in vivo anti-inflammatory activity using carrageenan induced rat paw edema and analgesic activity by tail flick and tail immersion methods. Results were obtained in a dose dependent manner. MECS (300 mg/kg) had shown significant (p < 0.05) anti-inflammatory and analgesic activity as compared to diclofenac sodium and morphine, respectively. From the results it may be concluded that MECS have good antioxidant, anti-inflammatory and analgesic potential.Colegio de Farmacéuticos de la Provincia de Buenos Aire

    SNPdetector: A Software Tool for Sensitive and Accurate SNP Detection

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    Identification of single nucleotide polymorphisms (SNPs) and mutations is important for the discovery of genetic predisposition to complex diseases. PCR resequencing is the method of choice for de novo SNP discovery. However, manual curation of putative SNPs has been a major bottleneck in the application of this method to high-throughput screening. Therefore it is critical to develop a more sensitive and accurate computational method for automated SNP detection. We developed a software tool, SNPdetector, for automated identification of SNPs and mutations in fluorescence-based resequencing reads. SNPdetector was designed to model the process of human visual inspection and has a very low false positive and false negative rate. We demonstrate the superior performance of SNPdetector in SNP and mutation analysis by comparing its results with those derived by human inspection, PolyPhred (a popular SNP detection tool), and independent genotype assays in three large-scale investigations. The first study identified and validated inter- and intra-subspecies variations in 4,650 traces of 25 inbred mouse strains that belong to either the Mus musculus species or the M. spretus species. Unexpected heterozgyosity in CAST/Ei strain was observed in two out of 1,167 mouse SNPs. The second study identified 11,241 candidate SNPs in five ENCODE regions of the human genome covering 2.5 Mb of genomic sequence. Approximately 50% of the candidate SNPs were selected for experimental genotyping; the validation rate exceeded 95%. The third study detected ENU-induced mutations (at 0.04% allele frequency) in 64,896 traces of 1,236 zebra fish. Our analysis of three large and diverse test datasets demonstrated that SNPdetector is an effective tool for genome-scale research and for large-sample clinical studies. SNPdetector runs on Unix/Linux platform and is available publicly (http://lpg.nci.nih.gov)

    Reticular dysgenesis-associated AK2 protects hematopoietic stem and progenitor cell development from oxidative stress.

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    Adenylate kinases (AKs) are phosphotransferases that regulate the cellular adenine nucleotide composition and play a critical role in the energy homeostasis of all tissues. The AK2 isoenzyme is expressed in the mitochondrial intermembrane space and is mutated in reticular dysgenesis (RD), a rare form of severe combined immunodeficiency (SCID) in humans. RD is characterized by a maturation arrest in the myeloid and lymphoid lineages, leading to early onset, recurrent, and overwhelming infections. To gain insight into the pathophysiology of RD, we studied the effects of AK2 deficiency using the zebrafish model and induced pluripotent stem cells (iPSCs) derived from fibroblasts of an RD patient. In zebrafish, Ak2 deficiency affected hematopoietic stem and progenitor cell (HSPC) development with increased oxidative stress and apoptosis. AK2-deficient iPSCs recapitulated the characteristic myeloid maturation arrest at the promyelocyte stage and demonstrated an increased AMP/ADP ratio, indicative of an energy-depleted adenine nucleotide profile. Antioxidant treatment rescued the hematopoietic phenotypes in vivo in ak2 mutant zebrafish and restored differentiation of AK2-deficient iPSCs into mature granulocytes. Our results link hematopoietic cell fate in AK2 deficiency to cellular energy depletion and increased oxidative stress. This points to the potential use of antioxidants as a supportive therapeutic modality for patients with RD
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