80 research outputs found

    Transformation of 2,4, 6-Trinitrotoluene (TNT) by Immobilized and Resting Cells of Arthrobacter SP.

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    Arthrobacter sp. transformed 2,4,6-trinitrotoluene (TNT) into two isomeric monoaminodinitrotoluenes viz, 4-amino-2,6-dinitrotoluene (4-ADNT), 2-amino- 4,6 –dinitrotoluene (2-ADNT) and also 2,4- diamino-6- nitrotoluene (2,4-DANT) under aerobic resting cell conditions. Experiments were carried out at 30° C (±1°C) in phosphate buffer with 60 mg per liter TNT at a pH of 7.2 (±0.2). Complete transformation of TNT occurred within 36 hours, yielding a mixture of monoaminodinitrotoluenes and diaminonitrotoluene. The major component was found to be 4-ADNT. Under the same experimental conditions, transformations were studied using barium alginate immobilized cells of Arthrobacter sp. Appropriate controls were run simultaneously. In both the cases, reactions were monitored every six hours by thin-layer chromatography (TLC) and gas chromatography (GC). The products were identified by gas chromatography coupled with mass spectrometry (GC-MS). Immobilization of Arthrobacter sp. in barium alginate resulted in more efficient TNT transformations, which were complete in 24 hours. The immobilized cells could be utilized at least for eight cycles and a decrease in rate of transformation was observed with each cycle

    The risk stratification of adverse neonatal outcomes in women with gestational diabetes (STRONG) study

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    Aims: To assess the risk of adverse neonatal outcomes in women with gestational diabetes (GDM) by identifying subgroups of women at higher risk to recognize the characteristics most associated with an excess of risk. Methods: Observational, retrospective, multicenter study involving consecutive women with GDM. To identify distinct and homogeneous subgroups of women at a higher risk, the RECursive Partitioning and AMalgamation (RECPAM) method was used. Overall, 2736 pregnancies complicated by GDM were analyzed. The main outcome measure was the occurrence of adverse neonatal outcomes in pregnancies complicated by GDM. Results: Among study participants (median age 36.8 years, pre-gestational BMI 24.8 kg/m2), six miscarriages, one neonatal death, but no maternal death was recorded. The occurrence of the cumulative adverse outcome (OR 2.48, 95% CI 1.59–3.87), large for gestational age (OR 3.99, 95% CI 2.40–6.63), fetal malformation (OR 2.66, 95% CI 1.00–7.18), and respiratory distress (OR 4.33, 95% CI 1.33–14.12) was associated with previous macrosomia. Large for gestational age was also associated with obesity (OR 1.46, 95% CI 1.00–2.15). Small for gestational age was associated with first trimester glucose levels (OR 1.96, 95% CI 1.04–3.69). Neonatal hypoglycemia was associated with overweight (OR 1.52, 95% CI 1.02–2.27) and obesity (OR 1.62, 95% CI 1.04–2.51). The RECPAM analysis identified high-risk subgroups mainly characterized by high pre-pregnancy BMI (OR 1.68, 95% CI 1.21–2.33 for obese; OR 1.38 95% CI 1.03–1.87 for overweight). Conclusions: A deep investigation on the factors associated with adverse neonatal outcomes requires a risk stratification. In particular, great attention must be paid to the prevention and treatment of obesity

    Time-Dependent COVID-19 Mortality in Patients with Cancer: An Updated Analysis of the OnCovid Registry

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    Importance: Whether the severity and mortality of COVID-19 in patients with cancer have improved in terms of disease management and capacity is yet to be defined. Objective: To test whether severity and mortality from COVID-19 among patients with cancer have improved during the course of the pandemic. Design, Setting, and Participants: OnCovid is a European registry that collects data on consecutive patients with solid or hematologic cancer and COVID-19. This multicenter case series study included real-world data from 35 institutions across 6 countries (UK, Italy, Spain, France, Belgium, and Germany). This update included patients diagnosed between February 27, 2020, and February, 14, 2021. Inclusion criteria were confirmed diagnosis of SARS-CoV-2 infection and a history of solid or hematologic cancer. Exposures: SARS-CoV-2 infection. Main Outcomes and Measures: Deaths were differentiated at 14 days and 3 months as the 2 landmark end points. Patient characteristics and outcomes were compared by stratifying patients across 5 phases (February to March 2020, April to June 2020, July to September 2020, October to December 2020, and January to February 2021) and across 2 major outbreaks (February to June 2020 and July 2020 to February 2021). Results: At data cutoff, 2795 consecutive patients were included, with 2634 patients eligible for analysis (median [IQR] age, 68 [18-77] years; 52.8% men). Eligible patients demonstrated significant time-dependent improvement in 14-day case-fatality rate (CFR) with estimates of 29.8% (95% CI, 0.26-0.33) for February to March 2020; 20.3% (95% CI, 0.17-0.23) for April to June 2020; 12.5% (95% CI, 0.06-22.90) for July to September 2020; 17.2% (95% CI, 0.15-0.21) for October to December 2020; and 14.5% (95% CI, 0.09-0.21) for January to February 2021 (all P <.001) across the predefined phases. Compared with the second major outbreak, patients diagnosed in the first outbreak were more likely to be 65 years or older (974 of 1626 [60.3%] vs 564 of 1008 [56.1%]; P =.03), have at least 2 comorbidities (793 of 1626 [48.8%] vs 427 of 1008 [42.4%]; P =.001), and have advanced tumors (708 of 1626 [46.4%] vs 536 of 1008 [56.1%]; P <.001). Complications of COVID-19 were more likely to be seen (738 of 1626 [45.4%] vs 342 of 1008 [33.9%]; P <.001) and require hospitalization (969 of 1626 [59.8%] vs 418 of 1008 [42.1%]; P <.001) and anti-COVID-19 therapy (1004 of 1626 [61.7%] vs 501 of 1008 [49.7%]; P <.001) during the first major outbreak. The 14-day CFRs for the first and second major outbreaks were 25.6% (95% CI, 0.23-0.28) vs 16.2% (95% CI, 0.13-0.19; P <.001), respectively. After adjusting for country, sex, age, comorbidities, tumor stage and status, anti-COVID-19 and anticancer therapy, and COVID-19 complications, patients diagnosed in the first outbreak had an increased risk of death at 14 days (hazard ratio [HR], 1.85; 95% CI, 1.47-2.32) and 3 months (HR, 1.28; 95% CI, 1.08-1.51) compared with those diagnosed in the second outbreak. Conclusions and Relevance: The findings of this registry-based study suggest that mortality in patients with cancer diagnosed with COVID-19 has improved in Europe; this improvement may be associated with earlier diagnosis, improved management, and dynamic changes in community transmission over time.

    Prevalence and impact of COVID-19 sequelae on treatment and survival of patients with cancer who recovered from SARS-CoV-2 infection: evidence from the OnCovid retrospective, multicentre registry study

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    Background: The medium-term and long-term impact of COVID-19 in patients with cancer is not yet known. In this study, we aimed to describe the prevalence of COVID-19 sequelae and their impact on the survival of patients with cancer. We also aimed to describe patterns of resumption and modifications of systemic anti-cancer therapy following recovery from SARS-CoV-2 infection. Methods: OnCovid is an active European registry study enrolling consecutive patients aged 18 years or older with a history of solid or haematological malignancy and who had a diagnosis of RT-PCR confirmed SARS-CoV-2 infection. For this retrospective study, patients were enrolled from 35 institutions across Belgium, France, Germany, Italy, Spain, and the UK. Patients who were diagnosed with SARS-CoV-2 infection between Feb 27, 2020, and Feb 14, 2021, and entered into the registry at the point of data lock (March 1, 2021), were eligible for analysis. The present analysis was focused on COVID-19 survivors who underwent clinical reassessment at each participating institution. We documented prevalence of COVID-19 sequelae and described factors associated with their development and their association with post-COVID-19 survival, which was defined as the interval from post-COVID-19 reassessment to the patients’ death or last follow-up. We also evaluated resumption of systemic anti-cancer therapy in patients treated within 4 weeks of COVID-19 diagnosis. The OnCovid study is registered in ClinicalTrials.gov, NCT04393974. Findings: 2795 patients diagnosed with SARS-CoV-2 infection between Feb 27, 2020, and Feb 14, 2021, were entered into the study by the time of the data lock on March 1, 2021. After the exclusion of ineligible patients, the final study population consisted of 2634 patients. 1557 COVID-19 survivors underwent a formal clinical reassessment after a median of 22·1 months (IQR 8·4–57·8) from cancer diagnosis and 44 days (28–329) from COVID-19 diagnosis. 234 (15·0%) patients reported COVID-19 sequelae, including respiratory symptoms (116 [49·6%]) and residual fatigue (96 [41·0%]). Sequelae were more common in men (vs women; p=0·041), patients aged 65 years or older (vs other age groups; p=0·048), patients with two or more comorbidities (vs one or none; p=0·0006), and patients with a history of smoking (vs no smoking history; p=0·0004). Sequelae were associated with hospitalisation for COVID-19 (p<0·0001), complicated COVID-19 (p<0·0001), and COVID-19 therapy (p=0·0002). With a median post-COVID-19 follow-up of 128 days (95% CI 113–148), COVID-19 sequelae were associated with an increased risk of death (hazard ratio [HR] 1·80 [95% CI 1·18–2·75]) after adjusting for time to post-COVID-19 reassessment, sex, age, comorbidity burden, tumour characteristics, anticancer therapy, and COVID-19 severity. Among 466 patients on systemic anti-cancer therapy, 70 (15·0%) permanently discontinued therapy, and 178 (38·2%) resumed treatment with a dose or regimen adjustment. Permanent treatment discontinuations were independently associated with an increased risk of death (HR 3·53 [95% CI 1·45–8·59]), but dose or regimen adjustments were not (0·84 [0·35–2·02]). Interpretation: Sequelae post-COVID-19 affect up to 15% of patients with cancer and adversely affect survival and oncological outcomes after recovery. Adjustments to systemic anti-cancer therapy can be safely pursued in treatment-eligible patients. Funding: National Institute for Health Research Imperial Biomedical Research Centre and the Cancer Treatment and Research Trust

    Wear and corrosion interactions on titanium in oral environment : literature review

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    The oral cavity is a complex environment where corrosive substances from dietary, human saliva, and oral biofilms may accumulate in retentive areas of dental implant systems and prostheses promoting corrosion at their surfaces. Additionally, during mastication, micromovements may occur between prosthetic joints causing a relative motion between contacting surfaces, leading to wear. Both processes (wear and corrosion) result in a bio-tribocorrosion system once that occurs in contact with biological tissues and fluids. This review paper is focused on the aspects related to the corrosion and wear behavior of titanium-based structures in the oral environment. Furthermore, the clinical relevance of the oral environment is focused on the harmful effect that acidic substances and biofilms, formed in human saliva, may have on titanium surfaces. In fact, a progressive degradation of titanium by wear and corrosion (tribocorrosion) mechanisms can take place affecting the performance of titanium-based implant and prostheses. Also, the formation of wear debris and metallic ions due to the tribocorrosion phenomena can become toxic for human tissues. This review gathers knowledge from areas like materials sciences, microbiology, and dentistry contributing to a better understanding of bio-tribocorrosion processes in the oral environment.(undefined

    Transformationof 2,4,6-Trinitrotoluene (tnt) By Immobilized And Resting Cells Of

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    Key words: monoaminodinitrotoluenes, dinitrotoluene, Arthrobacter sp., gas chromatography, mass spectrometry Copyright 1999 Kansas State University Phanerochaete chrysosporium, has been reported to mineralize TNT (Pasczynski and Crawford et al., 1995). In the utilization of TNT, a variety of microbes opt for either of the two principal pathways. In the first pathway, nitro groups are eliminated as nitrite/ nitrate (Boopathy et al., 1994; Vorbeck et al., 1994; Duque et al., 1993; Vanderberg et al., 1995). In the second pathway the nitro group is reduced to amines. This is usually observed in organisms that can draw energy by using the nitro group as the final electron acceptor, transforming it to amine (Cartright and Cain et al., 1959; Gorontzy et al., 1994; Pruess et al., 1993). A number of reduction products of TNT other than 4-ADNT, 2- ADNT 2,4- DANT, and 2,4,6-triaminotolouene (TAT) are known. Lewis et al. (1996) identified 2,4-dihydroxylamino-6nitrotoluene (2,4-DHANT) in the fermentation broth of Clostridium perfringens. In addition to these compounds, the azo-derivatives viz, 2-2&apos;, 6-6&apos;-tetranitro-4-azoxytoluene, and 2-2&apos;, 4-4&apos;- tetranitro-6-azoxytoluene are also known to be formed (Fiorella and Spain, 1997; Regan and Crawford 1994; McCormick et al., 1976). Members of the genus of Arthrobacter are universally distributed in all soils, having considerable nutritional versatility. Strains have been isolated that decompose herbicides, caffeine, nicotine, polychlorinated biphenyls, and other compounds (Gilbert and Crowly, 1997). Some strains have been reported to grow using nitrophenol, finally yielding hydroquinone and nitrite (Hanne et al., 1993). No reports of studies employing Arthrobacter sp. for degradation of TNT are known. Though the idea of using immobilized m..
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