534 research outputs found

    Adverse effects of anti-tuberculosis drugs on HepG2 cell bioenergetics

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    Tuberculosis (TB) is an intractable chronic infection. Disease treatment with anti-TB drugs remains challenging due to drug-induced hepatotoxicity. The toxicity of the anti-TB drugs rifampicin (RIF), isoniazid (INH) and pyrazinamide (PZA) either alone or in combination was investigated in HepG2 cells. Assays of intracellular adenosine triphosphate (ATP) levels at 4-, 24- and 48-h post-exposure to gradient concentrations of RIF, INH and PZA were conducted. Drug-induced effects on mitochondrial membrane potential (MMP), mitochondrial complex I and complex III activity, nicotinamide adenine dinucleotide (NAD+) levels and cellular lactate production were assessed. Decreased ATP levels were dose-dependent and correlated with drug exposure duration. Approximate 24-h IC50s were 0.5 mM, 70 mM and 84 mM for RIF, INH and PZA, respectively. Twenty-four hours post-drug treatment, reductions of MMP (p = 0.0005), mitochondrial complex I and III activities (p = 0.0001 and p = 0.0003, respectively), NAD+ levels (p = 0.0057) and increased lactate production (p < 0.0001) were observed. Drug combinations used to mimic cumulative drug treatments induced a synergistic inhibition of mitochondrial complex I activity. An assessment of cellular ultrastructure using transmission electron microscopy indicated drug-induced mitophagy. Collectively, our study suggests that hepatotoxicity of commonly employed anti-TB drugs is mediated by their curtailment of mitochondrial function

    Early and efficient detection of Mycobacterium tuberculosis in sputum by microscopic observation of broth cultures.

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    Early, efficient and inexpensive methods for the detection of pulmonary tuberculosis are urgently needed for effective patient management as well as to interrupt transmission. These methods to detect M. tuberculosis in a timely and affordable way are not yet widely available in resource-limited settings. In a developing-country setting, we prospectively evaluated two methods for culturing and detecting M. tuberculosis in sputum. Sputum samples were cultured in liquid assay (micro broth culture) in microplate wells and growth was detected by microscopic observation, or in Löwenstein-Jensen (LJ) solid media where growth was detected by visual inspection for colonies. Sputum samples were collected from 321 tuberculosis (TB) suspects attending Bugando Medical Centre, in Mwanza, Tanzania, and were cultured in parallel. Pulmonary tuberculosis cases were diagnosed using the American Thoracic Society diagnostic standards. There were a total of 200 (62.3%) pulmonary tuberculosis cases. Liquid assay with microscopic detection detected a significantly higher proportion of cases than LJ solid culture: 89.0% (95% confidence interval [CI], 84.7% to 93.3%) versus 77.0% (95% CI, 71.2% to 82.8%) (p = 0.0007). The median turn around time to diagnose tuberculosis was significantly shorter for micro broth culture than for the LJ solid culture, 9 days (interquartile range [IQR] 7-13), versus 21 days (IQR 14-28) (p<0.0001). The cost for micro broth culture (labor inclusive) in our study was US 4.56persample,versusUS4.56 per sample, versus US 11.35 per sample for the LJ solid culture. The liquid assay (micro broth culture) is an early, feasible, and inexpensive method for detection of pulmonary tuberculosis in resource limited settings

    Aggregation of human salivary Ca-proteinates in the presence of simple carbohydrates in vitro

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    The effect of 8 polyols and 14 aldoses or ketoses on the spontaneous aggregation of Ca-proteinates was followed spectrophotometrically in supernatants and filtrates of human mixed saliva. Each carbohydrate was added to the saliva samples at 37°C and the precipitated material was analyzed for protein, total carbohydrate and Ca. Based on their effect on aggregation, the carbohydrates could be divided into three groups: 1) those that showed no effect on aggregation: D-xylose, D-ribose and i-erythritol, 2) those that inhibited aggregation strongly: xylitol, Dsorbitol and D-mannitoi, and 3) those that inhibited aggregation moderately: glucose, fructose and sucrose. The inhibitory effect of the above polyols on the aggregation of Ca-proteinates varied greatly among the saliva donors, and correlated positively with the turbidity of the saliva and its protein content more than with the Ca-concentration or the pH of the saliva sample. It is suggested that inhibition of aggregation shown the most clearly for xylitol, sorbitol and mannitol manifests itself as a retardation of the final, irreversible aggregation of those glycoproteins that already exist in a precipitated form and which are responsible for the turbidity of saliva.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/75574/1/j.1600-0722.1986.tb01376.x.pd

    Vertical integration in production and services: development in transaction cost economics

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    In this paper, we first establish the core, fundamental concepts of Williamson's TCE, examining the different governance structures or the institutional alternatives that TCE theory proposes. We go on to describe some critical considerations and theoretical proposals that correspond fundamentally to Williamson's heuristic model, the integration of incentives in organizational forms, idiosyncratic demand, and how the concept of transaction is conceived in general.Peris-Ortiz, M.; Bonet, F.; Rueda Armengot, C. (2011). Vertical integration in production and services: development in transaction cost economics. Service Business. 5(1):87-97. doi:10.1007/s11628-011-0103-0S879751Alchian A (1965) The basic of some recent advances in the theory of management of the firm. J Ind Econ 14:30–41Alchian A (1969) Corporate management and property rights. In: Manne GH (ed) Economic Policy and Regulation of Corporate Securities. 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    Radiation induced angiosarcoma a sequela of radiotherapy for breast cancer following conservative surgery

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    Radiation induced angiosarcomas (RIA) can affect breast cancer patients who had radiotherapy following conservative breast surgery. They are very rare tumors and often their diagnosis is delayed due to their benign appearance and difficulty in differentiation from radiation induced skin changes. Therefore it is very important that clinicians are aware of their existence. We report here a case of RIA followed by discussion and review of literature

    International consensus definitions of clinical trial outcomes for kidney failure: 2020

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    Kidney failure is an important outcome for patients, clinicians, researchers, healthcare systems, payers, and regulators. However, no harmonized international consensus definitions of kidney failure and key surrogates of progression to kidney failure exist specifically for clinical trials. The International Society of Nephrology convened an international multi-stakeholder meeting to develop consensus on this topic. A core group, experienced in design, conduct, and outcome adjudication of clinical trials, developed a database of 64 randomized trials and the 163 included definitions relevant to kidney failure. Using an iterative process, a set of proposed consensus definitions were developed and subsequently vetted by the larger multi-stakeholder group of 83 participants representing 18 different countries. The consensus of the meeting participants was that clinical trial kidney failure outcomes should be comprised of a composite that includes receipt of a kidney transplant, initiation of maintenance dialysis, and death from kidney failure; it may also include outcomes based solely on laboratory measurements of glomerular filtration rate: a sustained low glomerular filtration rate and a sustained percent decline in glomerular filtration rate. Discussion included important considerations, such as (i) recognition of existing nomenclature for kidney failure; (ii) applicability across resource settings; (iii) ease of understanding for all stakeholders; and (iv) avoidance of inappropriate complexity so that the definitions can be used across ranges of populations and trial methodologies. The final definitions reflect the consensus for use in clinical trials

    Effect of bilberry juice on indices of muscle damage and inflammation in runners completing a half-marathon: a randomised, placebo-controlled trial.

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    Background: Emerging evidence indicates that fruits rich in polyphenols may attenuate exercise-induced muscle damage and associated markers of inflammation and soreness. This study was conducted to determine whether bilberry juice (BJ), which is particularly rich in polyphenols, reduces markers of muscle damage in runners completing a half marathon. Methods: A total of 21 recreationally trained runners (age 30.9 ± 10.4 y; mass 71.6 ± 11.0 kg; M=16; F=5) were recruited to a single blind, randomised, placebo-controlled, parallel study. Participants were block randomised to consume 2 x 200 ml of BJ or energy-matched control drink (PLA) for 5 d before the Sheffield Half Marathon, on race day, and for 2 days post-race. Measurements of delayed onset muscle soreness (DOMS), muscle damage (creatine kinase; CK) and inflammation (c-reactive protein ; CRP) were taken at baseline, pre-race, post-race, 24 h post-race and 48 h post-race. The effect of treatment on outcome measures was analysed using magnitude-based inferences based on data from 19 participants; 2 participants were excluded from the analyses because they did not provide samples for all time points. Results: The half marathon caused elevations in DOMS, CRP and CK. BJ had a possibly harmful effect on DOMS from pre-race to immediately post-race (11.6%, 90% CI ± 14.7%), a likely harmful effect on CRP from pre-race to 24 h post-race (mean difference ES 0.56, 90% CI ± 0.72) and a possibly harmful effect on CRP from pre-race to 48 h post-race (ES 0.12, 90% CI ± 0.69). At other time points, the differences between the BJ and PLA groups in DOMS and CRP were unclear, possibly trivial or likely trivial. Differences in the changes in CK between BJ and PLA were unclear at every time point other than from baseline to pre-race, where BJ had a possibly harmful effect on reducing muscle damage (ES 0.23, 90% CI ± 0.57). Conclusion: Despite being a rich source of antioxidant and anti-inflammatory phytochemicals, BJ evoked small to moderate increases in exercise-induced DOMS and CRP. Further larger studies are required to confirm these unexpected preliminary results

    Fusion of macrophages on lens implants resulting in the formation of giant cells

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    Giant cells on lens implants are understood to be a sign of chronic irritation. These multinucleated cells develop from macrophages by fusion and they disappear in successful cases along with the free-moving macrophages, when the fixed fibroblast-like cells and the proteinaceous capsule have succeeded in creating a continuous and effective separation on the surface of a lens implant. Details about the stages in the development of giant cells on lens implants as well as their significance as typical representatives of chronic granulomatous inflammation are discussed.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/47386/1/417_2005_Article_BF02171723.pd
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