974 resultados para stress testing
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AIM: Antidoping procedures are expected to greatly benefit from untargeted metabolomic approaches through the discovery of new biomarkers of prohibited substances abuse. RESULTS: Endogenous steroid metabolites were monitored in urine samples from a controlled elimination study of testosterone undecanoate after ingestion. A platform coupling ultra-high pressure LC with high-resolution quadrupole TOF MS was used and high between-subject metabolic variability was successfully handled using a multiblock data analysis strategy. Links between specific subsets of metabolites and influential genetic polymorphisms of the UGT2B17 enzyme were highlighted. CONCLUSION: This exploratory metabolomic strategy constitutes a first step toward a better understanding of the underlying patterns driving the high interindividual variability of steroid metabolism. Promising biomarkers were selected for further targeted study.
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BACKGROUND: A growing number of patients with chronic hepatitis B is being treated for extended periods with nucleoside and/or nucleotide analogs. In this context, antiviral resistance represents an increasingly common and complex issue. METHODS: Mutations in the hepatitis B virus (HBV) reverse transcriptase (rt) gene and viral genotypes were determined by direct sequencing of PCR products and alignment with reference sequences deposited in GenBank. RESULTS: Plasma samples from 60 patients with chronic hepatitis B were analyzed since March 2009. The predominant mutation pattern identified in patients with virological breakthrough was rtM204V/I ± different compensatory mutations, conferring resistance to L-nucleosides (lamivudine, telbivudine, emtricitabine) and predisposing to entecavir resistance (n = 18). Complex mutation patterns with a potential for multidrug resistance were identified in 2 patients. Selection of a fully entecavir resistant strain was observed in a patient exposed to lamivudine alone. Novel mutations were identified in 1 patient. Wild-type HBV was identified in 9 patients with suspected virological breakthrough, raising concerns about treatment adherence. No preexisting resistance mutations were identified in treatment-naïve patients (n = 13). Viral genome amplification and sequencing failed in 16 patients, of which only 2 had a documented HBV DNA > 1000 IU/ml. HBV genotypes were D in 28, A in 6, B in 4, C in 3 and E in 3 patients. Results will be updated in August 2010 and therapeutic implications discussed. CONCLUSIONS: With expanding treatment options and a growing number of patients exposed to nucleoside and/or nucleotide analogs, sequence-based HBV antiviral resistance testing is expected to become a cornerstone in the management of chronic hepatitis B.
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In order to evaluate the Organon Teknika MB/BacT system used for testing indirect susceptibility to the alternative drugs ofloxacin (OFLO), amikacin (AMI), and rifabutin (RIF), and to the usual drugs of standard treatment regimes such as rifampin (RMP), isoniazid (INH), pyrazinamide (PZA), streptomycin (SM), ethambutol (EMB), and ethionamide (ETH), cultures of clinical specimens from 117 patients with pulmonary tuberculosis under multidrug-resistant investigation, admitted sequentially for examination from 2001 to 2002, were studied. Fifty of the Mycobacterium tuberculosis cultures were inoculated into the gold-standard BACTEC 460 TB (Becton Dickinson) for studying resistance to AMI, RIF, and OFLO, and the remaining 67 were inoculated into Lowenstein Jensen (LJ) medium (the gold standard currently used in Brazil) for studying resistance to RMP, INH, PZA, SM, EMB, and ETH. We observed 100% sensitivity for AMI (80.8-100), RIF (80.8-100), and OFLO (78.1-100); and 100% specificity for AMI (85.4-100), RIF (85.4-100), and OFLO (86.7-100) compared to the BACTEC system. Comparing the results obtained in LJ we observed 100% sensitivity for RMP (80-100), followed by INH - 95% (81.8-99.1), EMB - 94.7% (71.9-99.7), and 100% specificity for all drugs tested except for PZA - 98.3 (89.5-99.9) at 95% confidence interval. The results showed a high level of accuracy and demonstrated that the fully automated, non-radiometric MB/BacT system is indicated for routine use in susceptibility testing in public health laboratories.
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The molluscicidal evaluation of Euphorbia splendens var. hislopii (Crown of thorns) against Lymnaea columella snails, intermediate host of Fasciola hepatica, in irrigation ditches of the Pisciculture Station at Universidade Federal Rural do Rio de Janeiro, was studied under limited field conditions. An aqueous solution of the latex at 5 mg/l was tested in two irrigation ditches (experimental and control ditches), after initial sampling of the snail population present. Twenty-four hours after application of the product, it was verified that 97.4% of free L. columella snails and 100% of snails of the same species captive in cages and used as sentinels at three points equidistant from the application site in the experimental ditch, died. For Biomphalaria tenagophila and Melanoides tuberculata snails, present in the experimental ditch, the mortality was 100%, for the species Pomacea spp. the mortality was 40%. No mortality was verified in the free mollusks, or in the sentinels in the ditch used as control. E. splendens var. hislopii latex is thus an efficient natural molluscicide, which may be used as an alternative control agent against L. columella.
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BACKGROUND: During stress, vasopressin is a potent synergistic factor of CRH as a hypothalamic stimulator of the HPA axis. The measurements of CRH and vasopressin levels are cumbersome because of their instability and short half-life. Copeptin is a more stable peptide stoichiometrically released from the same precursor molecule. The aim of our study was to compare copeptin and cortisol levels in different stress situations. METHODS: Three groups of patients with increasing stress levels were investigated: a) healthy controls without apparent stress (n=20), b) hospitalized medical patients with moderate stress (n=25) and c) surgical patients 30 minutes after extubation, with maximal stress (n=29). In all patients we assessed cortisol and copeptin levels. Copeptin levels were measured with a new sandwich immunoassay. RESULTS: Cortisol levels in controls were (median, IQ range, 486 [397-588] nmol/L), not significantly different as compared to medical patients (438 [371-612] nmol/L, p=0.69). Cortisol levels in surgical patients after extubation were higher (744 [645-1062] nmol/L p<0.01 vs controls and medical patients). Copeptin levels in controls were 4.3 [3.2-5.5] pmol/L, which was lower as compared to medical patients (17.5 [6.4-24.1], p<0.001) and surgical patients after extubation (67.5 [37.8-110.0] pmol/L, p<0.001). The correlation between copeptin levels and cortisol was r=0.46, p<0.001. CONCLUSION: Copeptin is a novel marker of the individual stress level. It more subtly mirrors moderate stress as compared to cortisol values.
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In this study, we have evaluated the broth microdilution method (BMM) for susceptibility testing of Mycobacterium tuberculosis. A total of 43 clinical isolates of M. tuberculosis and H37Rv as a control strain were studied. All isolates were tested by the proportion method and the BMM for isoniazid (INH), rifampicin (RIF), streptomycin (STR), and ethambutol (ETM). The proportion method was carried out according to the National Committee for Clinical Laboratory Standards (NCCLS) on Löwenstein-Jensen (LJ) medium. The BMM was carried out using 7H9 broth with 96 well-plates. All strains were tested at 3.2-0.05 µg/ml, 16-0.25 µg/ml, 32-0.5 µg/ml, and 32-0.5 µg/ml concentrations for INH, RIF, STR, and ETM, respectively. When the BMM was compared with the proportion method, sensitivity was 100, 100, 96.9, and 90.2%, while specificity was 100, 85.7, 90.9, and 100% for INH, RIF, STR, and ETM, respectively. The plates were examined 7, 10, 14, and 21 days after incubation. The majority of the result were obtained at 14th days after incubation, while the proportion method result were ended in 21-28 days. According to our results, it may be suggested that the BMM is suitable for early determining of multidrug-resistance-M. tuberculosis strains in developed or developing countries.
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OBJECTIVE: The aim of this study is to create a standard test to approve the efficacy of a surgical sealant. An industrial test, the bulge-and-blister test, which is very convenient for measuring adhesion energy, is applied to the surgical field to quantify adhesion of bioadhesives. METHODS: Samples were composed of two circular layers of equine pericardium glued by the surgical sealant studied. The sample was fixed to a support with an industrial glue. The support and the bottom layer were perforated in the centre to allow injection of pressurised water. Water was progressively introduced through the hole in the support and the bottom layer to create a blister with constant radius, increasing height and internal pressure during this first step. At a critical pressure, delamination started, the radius and height of the blister increased and the pressure decreased. At this point, the adhesion energy could be determined. The experimental parameters were measured with a pressure sensor and an optical profilometry device for deflection. RESULTS: Adhesion testing was carried out in eight paired equine pericardium samples bonded with a Dermabond cyanoacrylate glue. The average value of the practical adhesion energy is 2.3 Jm(-2) with a standard deviation of 1.5 Jm(-2). CONCLUSION: Application of the bulge-and-blister test to the surgical field was achieved and allowed a quantification of adhesion of a surgical glue. Such information is essential to compare the different surgical glues presently available. The study of the impact of bonding conditions such as pressure, hygrometry or setting conditions will provide a better understanding of the characteristics of adhesion in the surgical field.
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Stress radiographs have been recommended in order to obtain a better objective quantification of abnormal compartment knee motion. This tool has showed to be superior in quantifying a posterior cruciate ligament (PCL) lesion compared to clinical or arthrometer evaluation. Different radiographic techniques have been described in literature to quantify posterior pathological laxity. In this study we evaluated the total amount of posterior displacement (PTD) and side to side difference (SSD), before and after surgical reconstruction of PCL or PCL and posterolateral complex (PLC), using two different stress radiography techniques (Telos stress and kneeling view). Twenty patients were included in this study. We found a statistical significant difference about both total PTD and SSD among the two techniques preoperatively and at follow-up, with greatest values occurring using the kneeling view. Although stress radiographies has been introduced to allow an objective quantification of laxity in ligamentous injured knee, we believe that further studies on a large numbers of subjects are required to define the relationship between PTD values, measured with stress knee radiography, particularly using kneeling view, and ligamentous knee injury, in order to obtain a real useful tool in the decision making process, as well as to evaluate the outcome after ligamentous surgery.
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In light of the recent publication of the safety, Health & Welfare at Work Bill 2004, which is set to target the construction industry in particular, the number of Irish employers implementing drug testing programmes in the workplace is set to increase. Little is known, however, about attitudes of Irish workers towards various aspects of drug testing. In order to address this matter, the author presents the findings of a cross-sectional survey of 148 construction trade apprentices in relation to their attitudes towards aspects of workplace drug testing. The extent to which their attitudes varied according to their levels of illegal drug use and alcohol use was also investigated. The results indicate that under some circumstances, testing is approved of. However, attitudes towards most aspects of drug testing are characterised by extreme variability. For example, nearly items were rejected by some respondents and accepted by others. It can be concluded that even if an employer designed a drug testing programme based on elements viewed more favourably, a substantial proportion of employees would still be likely to hold negative views towards some aspects of the programme. Furthermore, self-reported frequency of alcohol and drug use, particularly cannabis use, was associated to more negative reactions towards drug testing. Implications for implementing drug testing programmes in the workplace are discussed. The results of this study are intended to give employers an increased understanding of workers' attitudes towards drug testing programmes and to aid the development of effective substance-abuse prevention services.This resource was contributed by The National Documentation Centre on Drug Use.
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The application of DNA-based markers toward the task of discriminating among alternate salmon runs has evolved in accordance with ongoing genomic developments and increasingly has enabled resolution of which genetic markers associate with important life-history differences. Accurate and efficient identification of the most likely origin for salmon encountered during ocean fisheries, or at salvage from fresh water diversion and monitoring facilities, has far-reaching consequences for improving measures for management, restoration and conservation. Near-real-time provision of high-resolution identity information enables prompt response to changes in encounter rates. We thus continue to develop new tools to provide the greatest statistical power for run identification. As a proof of concept for genetic identification improvements, we conducted simulation and blind tests for 623 known-origin Chinook salmon (Oncorhynchus tshawytscha) to compare and contrast the accuracy of different population sampling baselines and microsatellite loci panels. This test included 35 microsatellite loci (1266 alleles), some known to be associated with specific coding regions of functional significance, such as the circadian rhythm cryptochrome genes, and others not known to be associated with any functional importance. The identification of fall run with unprecedented accuracy was demonstrated. Overall, the top performing panel and baseline (HMSC21) were predicted to have a success rate of 98%, but the blind-test success rate was 84%. Findings for bias or non-bias are discussed to target primary areas for further research and resolution.
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Objective: Aspergillus species are the main pathogens causing invasive fungal infections but the prevalence of other mould species is rising. Resistance to antifungals among these new emerging pathogens presents a challenge for managing of infections. Conventional susceptibility testing of non-Aspergillus species is laborious and often difficult to interpret. We evaluated a new method for real-time susceptibility testing of moulds based on their of growth-related heat production.Methods: Laboratory and clinical strains of Mucor spp. (n = 4), Scedoporium spp. (n = 4) and Fusarium spp. (n = 5) were used. Conventional MIC was determined by microbroth dilution. Isothermal microcalorimetry was performed at 37 C using Sabouraud dextrose broth (SDB) inoculated with 104 spores/ml (determined by microscopical enumeration). SDB without antifungals was used for evaluation of growth characteristics. Detection time was defined as heat flow exceeding 10 lW. For susceptibility testing serial dilutions of amphotericin B, voriconazole, posaconazole and caspofungin were used. The minimal heat inhibitory concentration (MHIC) was defined as the lowest antifungal concentration, inhbiting 50% of the heat produced by the growth control at 48 h or at 24 h for Mucor spp. Susceptibility tests were performed in duplicate.Results: Tested mould genera had distinctive heat flow profiles with a median detection time (range) of 3.4 h (1.9-4.1 h) for Mucor spp, 11.0 h (7.1-13.7 h) for Fusarium spp and 29.3 h (27.4-33.0 h) for Scedosporium spp. Graph shows heat flow (in duplicate) of one representative strain from each genus (dashed line marks detection limit). Species belonging to the same genus showed similar heat production profiles. Table shows MHIC and MIC ranges for tested moulds and antifungals.Conclusions: Microcalorimetry allowed rapid detection of growth of slow-growing species, such as Fusarium spp. and Scedosporium spp. Moreover, microcalorimetry offers a new approach for antifungal susceptibility testing of moulds, correlating with conventional MIC values. Interpretation of calorimetric susceptibility data is easy and real-time data on the effect of different antifungals on the growth of the moulds is additionally obtained. This method may be used for investigation of different mechanisms of action of antifungals, new substances and drug-drug combinations.
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Ninety-one percent of antenatal clinic attenders and 97% of women having a termination of pregnancy agreed to HIV testing on a named or anonymous basis. HIV period prevalence's for Antenatal clinic attenders, and women having termination of pregnancy tested in Dundee were 0.13% and 0.85% respectively and for antenatal clinic attenders in Edinburgh, 0.26%. For those at "low risk", rates for antenatal clinic attenders and women having termination of pregnancy in Dundee were 0.11% and 0.13%, and for antenatal clinic attenders in Edinburgh, 0.02%. In dundee HIV prevalence among women having a termination of pregnancy (0.85%) was significantly greater (p< 0.001) than that among antenatal clinic attenders (0.13%). The investigation's findings show that HIV undoubtedly is occurring among women at "low risk" and it is clear that a policy of selective voluntary testing of those at "high risk" only, is inadequate for pregnant women living in areas of high prevalence such as Edinburgh and Dundee. Moreover, when studying pregnant populations in such areas there is a need to include those having a termination of pregnancy.This resource was contributed by The National Documentation Centre on Drug Use.
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There are many factors contributing to individual variations in the response to stressful experiences. The present study evaluated the patterns of stress responses according to attachment representations in 28 adults from a community sample, plus 46 subjects expected to be particularly sensitive to stress, having been exposed during childhood and/or adolescence to traumatizing events such as abuse or potentially lethal illnesses. Subjects were given the Adult Attachment Interview, which provides attachment classifications, and the Trier Social Stress Test (TSST), involving an experimental psychosocial challenge. Subjective responses to the TSST, as well as saliva samples (assayed for cortisol) and blood plasma samples (assayed for ACTH and oxytocin) were collected before, during and after the stress procedure. The stress responses presented specific patterns according to attachment classifications. Subjects with an autonomous attachment classification reported relatively low subjective stress, they presented a moderate response of the hypothalamic-pituitary-adrenal (HPA) axis (ACTH and cortisol), and a high level of oxytocin. Subjects with a dismissing classification reported a moderate subjective stress, they presented an elevated response of the HPA axis, and moderate levels of oxytocin. Subjects with a preoccupied classification presented moderate levels of subjective stress, and of HPA response, and a relatively low level of oxytocin. Finally, subjects with an unresolved classification reported elevated subjective stress; they presented a suppressed HPA response, and moderate levels of oxytocin. These data support the notion that attachment representations may affect stress responses, and suggest a specific role of oxytocin in both the attachment system and the stress system.
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Antiretroviral resistance mutations (ARM) are one of the major obstacles for pharmacological human immunodeficiency virus (HIV) suppression. Plasma HIV-1 RNA from 306 patients on antiretroviral therapy with virological failure was analyzed, most of them (60%) exposed to three or more regimens, and 28% of them have started therapy before 1997. The most common regimens in use at the time of genotype testing were AZT/3TC/nelfinavir, 3TC/D4T/nelfinavir and AZT/3TC/efavirenz. The majority of ARM occurred at protease (PR) gene at residue L90 (41%) and V82 (25%); at reverse transcriptase (RT) gene, mutations at residue M184 (V/I) were observed in 64%. One or more thymidine analogue mutations were detected in 73%. The number of ARM at PR gene increased from a mean of four mutations per patient who showed virological failure at the first ARV regimens to six mutations per patient exposed to six or more regimens; similar trend in RT was also observed. No differences in ARM at principal codon to the three drug classes for HIV-1 clades B or F were observed, but some polymorphisms in secondary codons showed significant differences. Strategies to improve the cost effectiveness of drug therapy and to optimize the sequencing and the rescue therapy are the major health priorities.
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Hailey-Hailey disease (HHD) is an autosomal dominant disorder characterized by suprabasal cutaneous cell separation (acantholysis) leading to the development of erosive and oozing skin lesion. Micro RNAs (miRNAs) are endogenous post-transcriptional modulators of gene expression with critical functions in health and disease. Here, we evaluated whether the expression of specific miRNAs may play a role in the pathogenesis of HHD. Here, we report that miRNAs are expressed in a non-random manner in Hailey-Hailey patients. miR-125b appeared a promising candidate for playing a role in HHD manifestation. Both Notch1 and p63 are part of a regulatory signalling whose function is essential for the control of keratinocyte proliferation and differentiation and of note, the expression of both Notch1 and p63 is downregulated in HHD-derived keratinocytes. We found that both Notch1 and p63 expression is strongly suppressed by miR-125b expression. Additionally, we found that miR-125b expression is increased by an oxidative stress-dependent mechanism. Our data suggest that oxidative stress-mediated induction of miR-125b plays a specific role in the pathogenesis of HHD by regulating the expression of factors playing an important role in keratinocyte proliferation and differentiation.