623 research outputs found
Production of Phenylacetylcarbinol in a Stand Still Condition Using Two Phase System by Applying Yeast Cells Capable of Fermenting Dried Ephedra Extract and Molass as Biocatalysts
Microbial Biotransformation of benzaldehyde to L Phenylacetylcarbinol (L-PAC) as a key intermediate for L-ephedrine synthesis has been evaluated using immobilized Hansenula polymorpha. The cultivation of 10 ml Hansenula anomala inoculum for 48 h in the cultivation medium with glucose as a sole carbon source resulted in the highest ethanol concentration of 10.6 ± 0.53 g/l. This was followed by Hansenula polymorpha (4.06 ± 0.20 g/l) and Brettanomyces lambicus (2.94 ± 0.15 g/l), respectively. The cultivation using 100 ml dried Ephedra extract and molass in 1:1 ratio as a sole carbon source showed that microbes with ability to consume glucose, fructose and sucrose released high level of ethanol (g/l) included Hansenula polymorpha (43.4 ± 4.0), (41.8 ± 1.2) and Hansenula anomala (38.1 ± 2.5). A biotransformation experiment was conducted using wet biomass of 3.06 g/l dry biomass equivalent from the medium with dried Ephedra extract and molass in 1:1 ratio as carbon source. After the two phase system was stood aside for 24 h, Hansenula polymorpha generated an overall R-phenylacetylcarbinol (PAC) concentration of 3.97 and 3.72 mM at 4 OC and 35OC which was followed by Hansenula polymorpha (3.04 and 3.73 mM), Brettanomyces lambicus (1.24 and 2.98 mM) as well as Hansenula anomala (0.86 and 0.07 mM)
Phytochemical based strategies for pathogen control and Antioxidant Capacities of Rauwolfia serpentina Extracts
Rauwolfia serpentina (Apocynaceae) is used among rural Indian communities to treat arthritis, skin cancer, burns, eczema, psoriasis, digestive problems, high blood pressure, sedative and diabetes, despite very little supporting scientific evidence. Due to increased interest by both the scientific community and industry regarding the medicinal uses of this plant species, we identified, quantified and compared the phytochemical contents and antioxidant capacities of extracts of Rauwolfia serpentina. Apart from extensively characterizing this medicinal plant with regards to its organic acid, polyphenols/phenolic acid, alcohol, aldehyde, ketone, alkane, pyrimidine, indole, alkaloid, phytosterol, fatty acid and dicarboxylic acid contents and antioxidant capacities, we describe a modified extraction procedure for the purpose of general phytochemical characterization, and compare this to a aqueous ethanol extraction technique. From the results it is clear that Rauwolfia serpentina contains a variety of compounds with confirmed antioxidant capacity and other putative health benefits relating to the prevention or treatment of diabetes, cardiovascular disease, cancer and hypertension. The results also indicate that separate extractions of the Leaf extracts, better serve for general phytochemical characterization purposes, hence justifying its use for biological in vivo efficacy studies
Tribological Performance of the Continuous Steel Fiber-reinforced Cu based Friction Material for Heavy-duty Braking Applications
Brake pads are the major components of the wind turbine, which primarily consists of metal matrix and ceramic reinforcements. The ceramic particles plunge out during the application of brakes, which in turn leads to the transformation of the wear mechanism from adhesive to abrasive wear. This increases the wear rate and therefore the study investigates the possible replacement of ceramic reinforcements with continuous fibers that exhibit high strength and compatibility. In recent years, Cu-based brake pads that are fabricated by powder metallurgy route are widely used in wind turbines. In this study, continuous fibers of stainless steel SS304 are reinforced in the Cu matrix by the casting method to preserve the fiber alignment. The fabricated composite is characterized for microstructure, microhardness, and tribological behavior. Besides, a comprehensive analysis of the wear mechanism in the developed composite is presented based on the surface morphology, elemental composition, and phase analysis
Non-radial sign-changing solutions for the Schroedinger-Poisson problem in the semiclassical limit
We study the existence of nonradial sign-changing solutions to the
Schroedinger-Poisson system in dimension N>=3. We construct nonradial
sign-changing multi-peak solutions whose peaks are displaced in suitable
symmetric configurations and collapse to the same point. The proof is based on
the Lyapunov-Schmidt reduction
A neuronal network of mitochondrial dynamics regulates metastasis.
The role of mitochondria in cancer is controversial. Using a genome-wide shRNA screen, we now show that tumours reprogram a network of mitochondrial dynamics operative in neurons, including syntaphilin (SNPH), kinesin KIF5B and GTPase Miro1/2 to localize mitochondria to the cortical cytoskeleton and power the membrane machinery of cell movements. When expressed in tumours, SNPH inhibits the speed and distance travelled by individual mitochondria, suppresses organelle dynamics, and blocks chemotaxis and metastasis, in vivo. Tumour progression in humans is associated with downregulation or loss of SNPH, which correlates with shortened patient survival, increased mitochondrial trafficking to the cortical cytoskeleton, greater membrane dynamics and heightened cell invasion. Therefore, a SNPH network regulates metastatic competence and may provide a therapeutic target in cancer
Bronchoalveolar Lavage-microRNAs Are Potential Novel Biomarkers of Outcome after Lung Transplantation
Background. Primary graft dysfunction, infections, and acute rejection (AR) worsen lung transplantation (LTx) outcome and patient survival. Despite significant efforts, reliable biomarkers of acute lung allograft dysfunction are lacking. To address this issue, we profiled the bronchoalveolar lavage (BAL) miRNome in LTx patients. Methods. BAL-microRNAs (miRNAs) from 16 patients were collected 7 days (T0), 15 days (T1), and 3 months (T2) after bilateral LTx and profiled on low-density array. Unsupervised and supervised analyses were used to identify miRNAs associated with clinical features, pneumonia, or AR. Prognostic markers were identified using the Cox model. Targeted signaling pathways were predicted in silico. A second series of 11 patients were used to validate AR-associated miRNAs. Results. Variation in BAL-miRNAs was associated with acute lung allograft dysfunction. Increased levels of miR-23b-3p at T2 were detected in patients with pneumonia, whereas let-7f-5p, miR-146b-3p, miR-22-5p, miR-29c-5p, miR-362-5p, and miR-452-5p were upregulated at T2 in patients with AR. miR-148b-5p and miR-744-3p distinguished LTx patients with AR in both cohorts. Low miR-148b-5p and high miR-744-3p expression levels were significantly associated with a shorter time to AR either within the first year after LTx or during follow-up. Combination of the 2 miRNAs identified LTx patients with higher AR risk independently of clinical variables. Conclusions. Our data provide new insights into the roles of BAL-miRNAs in regulating the pulmonary environment after transplantation and suggest that these miRNAs could serve as biomarkers of early- or mid-stage events. If validated, these findings could pave the way to a personalized clinical approach in LTx patients
Phenotypic and genotypic Helicobacter pylori clarithromycin resistance and therapeutic outcome: benefits and limits
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Comprehensive genomic analysis reveals the prognostic role of LRRK2 copy-number variations in human malignancies
Genetic alterations of leucine-rich repeat kinase 2 (LRRK2), one of the most important contributors to familial Parkinson\u2019s disease (PD), have been hypothesized to play a role in cancer development due to demographical and preclinical data. Here, we sought to define the prevalence and prognostic significance of LRRK2 somatic mutations across all types of human malignancies by querying the publicly available online genomic database cBioPortal. Ninety-six different studies with 14,041 cases were included in the analysis, and 761/14,041 (5.4%) showed genetic alterations in LRRK2. Among these, 585 (76.9%) were point mutations, indels or fusions, 168 (22.1%) were copy number variations (CNVs), and 8 (1.0%) showed both types of alterations. One case showed the somatic mutation R1441C. A significant difference in terms of overall survival (OS) was noted between cases harboring somatic LRRK2 whole deletions, amplifications, and CNV-unaltered cases (median OS: 20.09, 57.40, and 106.57 months, respectively; p = 0.0008). These results suggest that both LRRK2 amplifications and whole gene deletions could play a role in cancer development, paving the way for future research in terms of potential treatment with LRRK2 small molecule inhibitors for LRRK2-amplified cases
po 080 v atpase g1 expression in human glioma stem cells correlates with erk activation
Introduction The vacuolar ATPase (V-ATPase) is a multisubunit proton pump acting in multiple processes in eukaryotic cells. Alteration of V-ATPase activity is associated to a wide range of human diseases including cancer. We have recently showed that V-ATPase expression has a central role in glioma stem cells (GSC) maintenance. Therefore we aimed to get insights into the signalling associated with V-ATPase expression in GSC. Material and methods Signalling survey was performed using phospho-specific antibodies and the Cancer 10-pathway Reporter Luciferase Kit. GSC were treated with Ammonium chloride (NH4Cl) (10–50 mM), Bafilomycin A1 (BafA1) (10 nM) and the ERK inhibitor PD98059 (10 uM) Cell Invasion through collagen matrix and sphere formation were evaluated after 48 hour of drugs treatment, while cell cycle, apoptosis and ROS production were evaluated by flow cytometry after 24 hour. Mitochondrial depolarization and activity were evaluated by flow cytometry after TMRE staining and western blot, respectively. Autophagy was analysed by western blot using an antibody to p62. All experiments were performed using primary GSC cultures with high and low levels of V-ATPase G1 subunit (V1G1HIGH and V1G1LOW; n=3 each). Results and discussions The MAPK/Erk pathway was significantly upregulated in V1G1HIGH GSC and V-ATPase impairment by BafA1 reduced Erk phosphorylation, besides decreasing lysosomal acidification. Therefore we investigated if this effect was specific for the pump activity or if it was related to lysosomal dysfunction or to MAPK/Erk signalling. The comparison of the three drugs revealed that only BafA1 treatment induced cells death, reduced clonogenicity and invasion ability and decreased the phosphorylation level of proteins involved in proliferation and pro-apoptotic processes. Moreover BafA1 was the only drug that, at not lethal dosage, impaired cell cycle progression. This effect was associated with an increase in ROS production and mitochondrial depolarization and using a ROS inhibitor the effects of BafA1 were reverted. Conclusion Taken together these results indicate that the V-ATPase play a central role in GSC viability that goes beyond lysosomal activity or ERK phosphorylation. Further studies are needed to elucidate the roles of the proton pump in GSC and to target this molecule for innovative anti-cancer strategies
Culture-based antibiotic susceptibility testing for Helicobacter pylori infection: a systematic review
Background Primary antibiotic resistance in Helicobacter pylori (H. pylori) strains is increasing worldwide, affecting therapy success. The use of therapies tailored on susceptibility pre-testing at culture has been proposed, but data are still conflicting. Method We performed a systematic review to evaluate the role of a culture-based therapeutic approach for H. pylori treatment, taking into account the sensitivity of culture and the success rates achieved with tailored therapies in different therapeutic steps. Results We analyzed data from 51 studies. Overall, H. pylori strains were isolated in 80.7% of 7889 patients, the success rates being 78.1%, 77.5%, 86.3% and 86.6%, before first-, second-, third-line or more therapies, respectively. In comparative studies, the infection was cured in 89.9% of 2052 patients treated with tailored therapies, and in 77.6% of 2516 patients receiving empiric therapy (P<0.001). However, in the subanalysis, the tailored approach achieved optimal eradication rates (>90%) only when it was applied before first-and second-line therapies, but not before third-line or more attempts (<80%). Moreover, no significant difference emerged between the 2 approaches when data from only the most recent (last 5 years) studies were considered, as well as in those performed in Western populations. Conclusions The attempt to achieve antibiotic susceptibility testing before treatment failed in 20% of infected patients managed in dedicated laboratories. Culture-tailored therapies administered after 2 or more therapies achieved suboptimal eradication rates. The role of bacterial culture in patients whose therapeutic management failed to eradicate H. pylori probably needs to be corroborated by further data
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