65 research outputs found
Isolation, Identification and Characterization of Urinary Tract Infectious Bacteria and the Effect of Different Antibiotics
Introduction: Urinary Tract Infection (UTI) defines a condition in which the urinary tract is infected with a pathogen causing inflammation which is a common, distressing and occasionally life threatening condition. UTI affects people of all ages and both gender. In all patients with UTI are reported with asymptomatic bacteriuria. Female are more susceptible to UTIs compared to male. To ensure appropriate therapy, current knowledge of the organisms that cause UTI and their antibiotic is susceptibility is mandatory. Methods: This study focused on the frequency of uropathogens and their antibiotic susceptibility in different gender in Madurai District. Cultural and biochemical characterization of uropathogens revealed the prevalence of both gram-positive and gram-negative organisms Results: E. coli was the predominant isolate isolated from the urine specimen followed by Pseudomonas aeruginosa, Klebsiella pneumoniae, Staphylococcus aureus, Proteus mirabilis and Enterococcus faecalis. Among the antibiotics tested, chloraphenicol and ciprofloxacin (100%) were found to be effective for empirical treatment of UTI and has covered the majority of urinary pathogens followed by tetracycline, gentamycin and kanamycin (83%), Ampicillin (67). Streptomycin, Rifampicin and amoxicillin were less effective (50%). Conclusion: Some of the isolates were resistant to penicillin-G, Streptomycin, rifampicin and amoxicillin which are more frequently prescribed and indicates that increased consumption of a particular antibiotic leads to acquisition of resistance by the uropathogens. Resistance rates among common uropathogens continue to evolve and appear to be increasing too many commonly used antimicrobial agents and a continued surveillance of resistance rates among uropathogens is needed to ensure appropriate recommendations for the treatment of the urinary tract infections. Keywords: Urinary tract infection, Drug resistence, Uropathogens, Biochemical tests
Multilayer modeling of porous grain surface chemistry I. The GRAINOBLE model
Mantles of iced water, mixed with CO, H2CO, and CH3OH are formed during the
so called prestellar core phase. In addition, radicals are also thought to be
formed on the grain surfaces, and to react to form complex organic molecules
later on, during the warm-up phase of the protostellar evolution. We aim to
study the formation of the grain mantles during the prestellar core phase and
the abundance of H2CO, CH3OH, and radicals trapped in them. We have developed a
macrosopic statistic multilayer model that follows the formation of grain
mantles with time and that includes two effects that may increase the number of
radicals trapped in the mantles: i) at each time of the mantle formation, only
the surface layer is chemically active rather than the entire bulk, and ii) the
porous structure of grains allows to trap reactive particles. The model
considers a network of H, O and CO forming neutral species such as water, CO,
formaldehyde, and methanol, plus several radicals. We run a large grid of
models to study the impact of the mantle multilayer nature and grain porous
structure. In addition, we explored the influence of the uncertainty of other
key parameters on the mantle composition. Our model predicts relatively large
abundances of radicals. In addition, the multilayer approach makes it possible
to follow the chemical differentiation within the grain mantle, showing that
the mantles are far from being uniform. For example, methanol is mostly present
in the outer layers of the mantles whereas CO and other reactive species are
trapped in the inner layers. The overall mantle composition depends on the
density and age of the prestellar core, and on some microscopic parameters.
Comparison with observations allows us to constrain the value of few parameters
and provide some indications on the physical conditions during the formation of
the ices.Comment: 20 pages and 19 figures. Accepted in Astronomy & Astrophysic
Synthesis and Isomeric Analysis of RuII Complexes Bearing Pentadentate Scaffolds
A RuII-pentadentate polypyridyl complex [RuII(κ-N5-bpy2PYMe)Cl]+ (1+, bpy2PYMe = 1-(2-pyridyl)-1,1-bis(6-2,2'-bipyridyl)ethane) and its aqua derivative [RuII(κ-N5-bpy2PYMe)(H2O)]2+ (22+) were synthesized and characterized by experimental and computational methods. In MeOH, 1+ exists as two isomers in different proportions, cis (70%) and trans (30%), which are interconverted under thermal and photochemical conditions by a sequence of processes: chlorido decoordination, decoordination/recoordination of a pyridyl group, and chlorido recoordination. Under oxidative conditions in dichloromethane, trans-12+ generates a [RuIII(κ-N4-bpy2PYMe)Cl2]+ intermediate after the exchange of a pyridyl ligand by a Cl- counterion, which explains the trans/cis isomerization observed when the system is taken back to Ru(II). On the contrary, cis-12+ is in direct equilibrium with trans-12+, with absence of the κ-N4-bis-chlorido RuIII-intermediate. All these equilibria were modeled by density functional theory calculations. Interestingly, the aqua derivative is obtained as a pure trans-[RuII(κ-N5-bpy2PYMe)(H2O)]2+ isomer (trans-22+), while the addition of a methyl substituent to a single bpy of the pentadentate ligand leads to the formation of a single cis isomer for both chlorido and aqua derivatives [RuII(κ-N5-bpy(bpyMe)PYMe)Cl]+ (3+) and [RuII(κ-N5-bpy(bpyMe)PYMe)(H2O)]2+ (42+) due to the steric constraints imposed by the modified ligand. This system was also structurally and electrochemically compared to the previously reported [RuII(PY5Me2)X]n+ system (X = Cl, n = 1 (5+); X = H2O, n = 2 (62+)), which also contains a κ-N5-RuII coordination environment, and to the newly synthesized [RuII(PY4Im)X]n+ complexes (X = Cl, n = 1 (7+); X = H2O, n = 2 (82+)), which possess an electron-rich Hκ-N4C-RuII site due to the replacement of a pyridyl group by an imidazolic carbene
Mechanosensitive ACKR4 scavenges CCR7 chemokines to facilitate T cell de-adhesion and passive transport by flow in inflamed afferent lymphatics.
T cell migration via afferent lymphatics to draining lymph nodes (dLNs) depends on expression of CCR7 in T cells and CCL21 in the lymphatic vasculature. Once T cells have entered lymphatic capillaries, they slowly migrate into contracting collecting vessels. Here, lymph flow picks up, inducing T cell detachment and rapid transport to the dLNs. We find that the atypical chemokine receptor 4 (ACKR4), which binds and internalizes CCL19 and CCL21, is induced by lymph flow in endothelial cells lining lymphatic collectors, enabling them to scavenge these chemokines. In the absence of ACKR4, migration of T cells to dLNs in TPA-induced inflammation is significantly reduced. While entry into capillaries is not impaired, T cells accumulate in the ACKR4-deficient dermal collecting vessel segments. Overall, our findings identify an ACKR4-mediated mechanism by which lymphatic collectors facilitate the detachment of lymph-borne T cells in inflammation and their transition from crawling to free-flow toward the dLNs
Grain Surface Models and Data for Astrochemistry
AbstractThe cross-disciplinary field of astrochemistry exists to understand the formation, destruction, and survival of molecules in astrophysical environments. Molecules in space are synthesized via a large variety of gas-phase reactions, and reactions on dust-grain surfaces, where the surface acts as a catalyst. A broad consensus has been reached in the astrochemistry community on how to suitably treat gas-phase processes in models, and also on how to present the necessary reaction data in databases; however, no such consensus has yet been reached for grain-surface processes. A team of ∼25 experts covering observational, laboratory and theoretical (astro)chemistry met in summer of 2014 at the Lorentz Center in Leiden with the aim to provide solutions for this problem and to review the current state-of-the-art of grain surface models, both in terms of technical implementation into models as well as the most up-to-date information available from experiments and chemical computations. This review builds on the results of this workshop and gives an outlook for future directions
Withdrawal of infliximab therapy in ankylosing spondylitis in persistent clinical remission, results from the REMINEA study
Altres ajuts: This work is conducted under the umbrella of the Rheumatology Society of Catalonia and supported by Merck Research Laboratories.Background: Recent data suggest that anti-TNF doses can be reduced in ankylosing spondylitis (AS) patients. Some authors even propose withdrawing treatment in patients in clinical remission; however, at present there is no evidence to support this. Objective: To assess how long AS patients with persistent clinical remission remained free of flares after anti-TNF withdrawal and to evaluate the effects of treatment reintroduction. We also analyze the characteristics of patients who did not present clinical relapse. Methods: Multicenter, prospective, observational study of a cohort of patients with active AS who had received infliximab as a first anti-TNF treatment and who presented persistent remission (more than 6 months). We recorded at baseline and every 6-8 weeks over the 12-month period the age, gender, disease duration, peripheral arthritis or enthesitis, HLA-B27 status, BASDAI, CRP, ESR, BASFI, and three visual analogue scales, spine global pain, spinal night time pain, and patient's global assessment. Results: Thirty-six out of 107 patients (34%) presented persistent remission and were included in our study. After treatment withdrawal, 21 of these 36 patients (58%) presented clinical relapse during follow-up. Infliximab therapy was reintroduced and only 52% achieved clinical remission, as they had before the discontinuation of infliximab; in an additional 10%, reintroduction of infliximab was ineffective, obliging us to change the anti-TNF therapy. No clinical or biological factors were associated with the occurrence of relapse during the follow-up. Conclusions: Two thirds of patients in clinical remission presented clinical relapse shortly after infliximab withdrawal. Although the reintroduction of infliximab treatment was safe, half of the patients did not present the same clinical response that they had achieved prior to treatment withdrawal
3-hydroxy-L-kynurenamine is an immunomodulatory biogenic amine
Tryptophan catabolism is a major metabolic pathway utilized by several professional and non-professional antigen presenting cells to maintain immunological tolerance. Here we report that 3-hydroxy-l-kynurenamine (3-HKA) is a biogenic amine produced via an alternative pathway of tryptophan metabolism. In vitro, 3-HKA has an anti-inflammatory profile by inhibiting the IFN-gamma mediated STAT1/NF-kappa Beta pathway in both mouse and human dendritic cells (DCs) with a consequent decrease in the release of pro-inflammatory chemokines and cytokines, most notably TNF, IL-6, and IL12p70. 3-HKA has protective effects in an experimental mouse model of psoriasis by decreasing skin thickness, erythema, scaling and fissuring, reducing TNF, IL-1 beta, IFN-gamma, and IL-17 production, and inhibiting generation of effector CD8(+) T cells. Similarly, in a mouse model of nephrotoxic nephritis, besides reducing inflammatory cytokines, 3-HKA improves proteinuria and serum urea nitrogen, overall ameliorating immune-mediated glomerulonephritis and renal dysfunction. Overall, we propose that this biogenic amine is a crucial component of tryptophan-mediated immune tolerance. 3-hydroxy-L-kynurenamine (3-HKA) is a metabolite deriving from a lateral pathway of tryptophan catabolism. Here the authors identify 3-HKA as a biogenic amine and show it has anti-inflammatory properties that can protect mice against psoriasis and nephrotoxic nephritis.Peer reviewe
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