244 research outputs found

    The association between indwelling urinary catheter use in the elderly and urinary tract infection in acute care

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    BACKGROUND: The use of indwelling urinary catheters (IUCs) is thought to be the most significant risk factor for developing nosocomial urinary tract infections (UTIs). However, it is unclear how many elderly patients have preexisting bacteriuria prior to IUC placement. The purpose of this study was to determine 1) the frequency and appropriateness of IUC use in the Emergency Department (ED) in elderly patients admitted to our acute care hospital, 2) the percentage of elderly patients with an IUC who were discharged from the hospital with a diagnosis of UTI, 3) the percentage of patients with IUCs who were diagnosed and treated for UTI in the ED or who had admission bacteriuria ≥10(5 )organisms/ml indicating preexisting UTI, and 4) the percentage of patients with no indication of UTI on admission who had inappropriately placed IUCs and subsequently were diagnosed with a UTI. METHODS: Retrospective chart review. Chi square used to test significance of differences in proportions. RESULTS: Seventy three percent of patients who received an IUC in the ED were elderly (≥65 years old). During the study period, 277 elderly patients received an IUC prior to admission. Of these, 77 (28%) were diagnosed with UTI during their hospitalization. Fifty three (69%) of those diagnosed with a UTI by discharge either had the UTI diagnosed in the ED or had bacteriuria ≥10(5 )organisms/ml prior to IUC placement. Of the 24 elderly patients who developed a catheter-associated UTI (i.e., 9% of the elderly population who received an IUC), 11 of the IUCs were placed inappropriately. Thus, 4% of elderly patients with no indication of UTI on admission who received an inappropriate IUC in the ED had a primary or secondary diagnosis of UTI by discharge. The overall rate of nosocomial UTI due to an inappropriately placed IUC was the same in males and females. CONCLUSION: This study indicates that the strong association between IUC use and UTI may be partly explained by the high prevalence of preexisting UTI prior to IUC placement. Further prospective studies are needed to clarify the true risk vs benefit ratio for IUC use in acutely ill elderly patients

    Adenosine Kinase of T. b. rhodesiense Identified as the Putative Target of 4-[5-(4-phenoxyphenyl)-2H-pyrazol-3-yl]morpholine Using Chemical Proteomics

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    Human African trypanosomiasis (HAT), a devastating and fatal parasitic disease endemic in sub-Saharan Africa, urgently needs novel targets and efficacious chemotherapeutic agents. Recently, we discovered that 4-[5-(4-phenoxyphenyl)-2H-pyrazol-3-yl]morpholine exhibits specific antitrypanosomal activity toward T. b. rhodesiense, the causative agent of the acute form of HAT. Here we applied a chemical proteomics approach to find the cellular target of this compound. Adenosine kinase, a key enzyme of the parasite purine salvage pathway, was isolated and identified as compound binding partner. Direct binding assays using recombinant protein, and tests on an adenosine kinase knock-down mutant of the parasite produced by RNA interference confirmed TbrAK as the putative target. Kinetic analyses showed that the title compound is an activator of adenosine kinase and that the observed hyperactivation of TbrAK is due to the abolishment of the intrinsic substrate-inhibition. Whereas hyperactivation as a mechanism of action is well known from drugs targeting cell signaling, this is a novel and hitherto unexplored concept for compounds targeting metabolic enzymes, suggesting that hyperactivation of TbrAK may represent a novel therapeutic strategy for the development of trypanocides

    Dynamic Modelling under Uncertainty: The Case of Trypanosoma brucei Energy Metabolism

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    Kinetic models of metabolism require detailed knowledge of kinetic parameters. However, due to measurement errors or lack of data this knowledge is often uncertain. The model of glycolysis in the parasitic protozoan Trypanosoma brucei is a particularly well analysed example of a quantitative metabolic model, but so far it has been studied with a fixed set of parameters only. Here we evaluate the effect of parameter uncertainty. In order to define probability distributions for each parameter, information about the experimental sources and confidence intervals for all parameters were collected. We created a wiki-based website dedicated to the detailed documentation of this information: the SilicoTryp wiki (http://silicotryp.ibls.gla.ac.uk/wiki/Glycolysis). Using information collected in the wiki, we then assigned probability distributions to all parameters of the model. This allowed us to sample sets of alternative models, accurately representing our degree of uncertainty. Some properties of the model, such as the repartition of the glycolytic flux between the glycerol and pyruvate producing branches, are robust to these uncertainties. However, our analysis also allowed us to identify fragilities of the model leading to the accumulation of 3-phosphoglycerate and/or pyruvate. The analysis of the control coefficients revealed the importance of taking into account the uncertainties about the parameters, as the ranking of the reactions can be greatly affected. This work will now form the basis for a comprehensive Bayesian analysis and extension of the model considering alternative topologies

    Hypersensitivity reactions related to oxaliplatin (OHP)

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    Patients treated with platinum compounds are subject to hypersensitivity reactions. Our study has highlighted the reactions related to oxaliplatin (OHP) infusion. One hundred and twenty-four patients affected by advanced colorectal cancer were treated with different schedules containing OHP, at the Institute of Haematology and Medical Oncology 'L. and A. Seragnoli' of Bologna and at the Medical Oncology Division of Livorno Hospital. Seventeen patients (13%) showed hypersensitivity reactions after a few minutes from the start of the OHP infusion. Usually, these reactions were seen after 2-17 exposures to OHP (Mean\ub1s.e.: 9.4\ub11.07). No patient experienced allergic reactions at his/her first OHP infusion. Eight patients developed a mild reaction consisting of flushing and swelling of the face and hands, itching, sweating and lachrymation. The remaining nine patients showed a moderate-severe reaction with dyspnoea, wheezing, laryngospasm, psycho-motor agitation, tachycardia, precordial pain, diffuse erythema, itching and sweating. Six patients out of 17 were re-exposed to the drug with premedication of steroids and all except one developed the hypersensitivity reaction again. The cumulative dose, the time of exposure to OHP and the clinical features are variable and unpredictable. The risk of developing hypersensitivity reactions in patients treated with a short infusion of OHP cannot be underestimated. \ua9 2003 Cancer Research UK

    Evidence for Loss of a Partial Flagellar Glycolytic Pathway during Trypanosomatid Evolution

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    Classically viewed as a cytosolic pathway, glycolysis is increasingly recognized as a metabolic pathway exhibiting surprisingly wide-ranging variations in compartmentalization within eukaryotic cells. Trypanosomatid parasites provide an extreme view of glycolytic enzyme compartmentalization as several glycolytic enzymes are found exclusively in peroxisomes. Here, we characterize Trypanosoma brucei flagellar proteins resembling glyceraldehyde-3-phosphate dehydrogenase (GAPDH) and phosphoglycerate kinase (PGK): we show the latter associates with the axoneme and the former is a novel paraflagellar rod component. The paraflagellar rod is an essential extra-axonemal structure in trypanosomes and related protists, providing a platform into which metabolic activities can be built. Yet, bioinformatics interrogation and structural modelling indicate neither the trypanosome PGK-like nor the GAPDH-like protein is catalytically active. Orthologs are present in a free-living ancestor of the trypanosomatids, Bodo saltans: the PGK-like protein from B. saltans also lacks key catalytic residues, but its GAPDH-like protein is predicted to be catalytically competent. We discuss the likelihood that the trypanosome GAPDH-like and PGK-like proteins constitute molecular evidence for evolutionary loss of a flagellar glycolytic pathway, either as a consequence of niche adaptation or the re-localization of glycolytic enzymes to peroxisomes and the extensive changes to glycolytic flux regulation that accompanied this re-localization. Evidence indicating loss of localized ATP provision via glycolytic enzymes therefore provides a novel contribution to an emerging theme of hidden diversity with respect to compartmentalization of the ubiquitous glycolytic pathway in eukaryotes. A possibility that trypanosome GAPDH-like protein additionally represents a degenerate example of a moonlighting protein is also discussed

    Phase II study of weekly oxaliplatin and 24-h infusion of high-dose 5-fluorouracil and folinic acid in the treatment of advanced gastric cancer

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    [[abstract]]To investigate the efficacy and safety of combining weekly oxaliplatin with weekly 24-h infusion of high-dose 5-fluorouracil (5-FU) and folinic acid ( FA) in treatment of patients with advanced gastric cancer. Patients with histologically confirmed, locally advanced or recurrent/metastatic gastric cancer were studied. Oxaliplatin 65 mg m(-2) 2-h intravenous infusion, and 5-FU 2600 mg m(-2) plus FA 300 mg m(-2) 24-h intravenous infusion, were given on days 1 and 8, repeated every 3 weeks. Between January 2001 through January 2002, 55 patients were enrolled. The median age was 64 years (range: 22-75). In all, 52 patients (94.5%) had recurrent or metastatic disease and three patients had locally advanced disease. Among 50 patients evaluable for tumour response, 28 patients achieved partial response, with an overall response rate of 56% (95% confidence interval (CI): 41.8-70.3%). All 55 patients were evaluated for survival and toxicities. Median time to progression and overall survival were 5.2 and 10.0 months, respectively, during median follow-up time of 24.0 months. Major grades 3-4 toxicities were neutropenia in 23 cycles (7.1%) and thrombocytopenia in 16 cycles (5.0%). Treatment was discontinued for treatment-related toxicities in nine patients (16.4%), of whom eight were due to oxaliplatin-related neurotoxicity. One patient (1.8%) died of neutropenic sepsis. This oxaliplatin-containing regimen is effective in the treatment of advanced gastric cancer. Except for neurotoxicity that often develops after prolonged use of oxaliplatin, the regimen is well tolerated

    Combined modalities of resistance in an oxaliplatin-resistant human gastric cancer cell line with enhanced sensitivity to 5-fluorouracil

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    To identify mechanisms underlying oxaliplatin resistance, a subline of the human gastric adenocarcinoma TSGH cell line, S3, was made resistant to oxaliplatin by continuous selection against increasing drug concentrations. Compared with the parental TSGH cells, the S3 subline showed 58-fold resistance to oxaliplatin; it also displayed 11-, 2-, and 4.7-fold resistance to cis-diammine-dichloroplatinum (II) (CDDP), copper sulphate, and arsenic trioxide, respectively. Interestingly, S3 cells were fourfold more susceptible to 5-fluorouracil-induced cytotoxicity due to downregulation of thymidylate synthase. Despite elevated glutathione levels in S3 cells, there was no alteration of resistant phenotype to oxaliplatin or CDDP when cells were co-treated with glutathione-depleting agent, l-buthionine-(S,R)-sulphoximine. Cellular CDDP and oxaliplatin accumulation was decreased in S3 cells. In addition, amounts of oxaliplatin- and CDDP–DNA adducts in S3 cells were about 15 and 40% of those seen with TSGH cells, respectively. Western blot analysis showed increased the expression level of copper transporter ATP7A in S3 cells compared with TSGH cells. Partial reversal of the resistance of S3 cells to oxaliplatin and CDDP was observed by treating cell with ATP7A-targeted siRNA oligonucleotides or P-type ATPase-inhibitor sodium orthovanadate. Besides, host reactivation assay revealed enhanced repair of oxaliplatin- or CDDP-damaged DNA in S3 cells compared with TSGH cells. Together, our results show that the mechanism responsible for oxaliplatin and CDDP resistance in S3 cells is the combination of increased DNA repair and overexpression of ATP7A. Downregulation of thymidylate synthase in S3 cells renders them more susceptible to 5-fluorouracil-induced cytotoxicity. These findings could pave ways for future efforts to overcome oxaliplatin resistance

    How do 66 European institutional review boards approve one protocol for an international prospective observational study on traumatic brain injury? Experiences from the CENTER-TBI study

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    Background The European Union (EU) aims to optimize patient protection and efficiency of health-care research by harmonizing procedures across Member States. Nonetheless, further improvements are required to increase multicenter research efficiency. We investigated IRB procedures in a large prospective European multicenter study on traumatic brain injury (TBI), aiming to inform and stimulate initiatives to improve efficiency. Methods We reviewed relevant documents regarding IRB submission and IRB approval from European neurotrauma centers participating in the Collaborative European NeuroTrauma Effectiveness Research in Traumatic Brain Injury (CENTER-TBI). Documents included detailed information on IRB procedures and the duration from IRB submission until approval(s). They were translated and analyzed to determine the level of harmonization of IRB procedures within Europe. Results From 18 countries, 66 centers provided the requested documents. The primary IRB review was conducted centrally (N = 11, 61%) or locally (N = 7, 39%) and primary IRB approval was obtained after one (N = 8, 44%), two (N = 6, 33%) or three (N = 4, 23%) review rounds with a median duration of respectively 50 and 98 days until primary IRB approval. Additional IRB approval was required in 55% of countries and could increase duration to 535 days. Total duration from submission until required IRB approval was obtained was 114 days (IQR 75-224) and appeared to be shorter after submission to local IRBs compared to central IRBs (50 vs. 138 days, p = 0.0074). Conclusion We found variation in IRB procedures between and within European countries. There were differences in submission and approval requirements, number of review rounds and total duration. Research collaborations could benefit from the implementation of more uniform legislation and regulation while acknowledging local cultural habits and moral values between countries.Peer reviewe
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