Your browser doesn't support javascript.
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 646
Filtrar
1.
Am J Ophthalmol ; 2020 Feb 26.
Artigo em Inglês | MEDLINE | ID: mdl-32112772

RESUMO

PURPOSE: To determine if agreement between subjective interpretations of Scheimpflug tomography maps of corneas with Fuchs endothelial corneal dystrophy (FECD) is affected by daily and hourly changes in corneal edema. DESIGN: Reliability analysis. METHODS: Scheimpflug imaging pachymetry and posterior elevation maps of corneas with a range of severity of FECD were evaluated in a randomized manner for the presence of three tomographic features of edema. Agreement between interpretations of one masked observer was assessed (percentage, and κ-statistic with 95% CI) for images taken within minutes on the same day, for images taken at a similar time on a different day, and for images taken over the course of a morning. Intra- and inter-observer agreement was also assessed. RESULTS: Interpretations for individual tomographic features agreed for ≥88% of images (κ≥0.75) taken within minutes on the same day; complete disagreement (i.e. disagreement for all 3 tomographic features in an image) occurred in ≤3% of images. Interpretations agreed for ≥77% of images (κ≥0.52) taken at a similar time on a different day; complete disagreement did not occur. Interpretations agreed for ≥81% of images (κ≥0.61) taken over the course of a morning; complete disagreement occurred ≤6% of images. Intra-observer agreement was ≥93% (κ≥0.83) and inter-observer agreement was ≥93% (κ≥0.66); complete disagreement did not occur. CONCLUSIONS: Subjective interpretation of Scheimpflug images in FECD is highly repeatable for disease classification. Although small variations in interpretations resulted from pathophysiologic changes in corneal hydration and other factors, clinically significant disagreements in interpretation were uncommon and therefore unlikely to affect clinical decision-making.

2.
Am J Hematol ; 2020 Mar 02.
Artigo em Inglês | MEDLINE | ID: mdl-32124470

RESUMO

Acute leukemias of ambiguous lineage (ALAL) comprise acute undifferentiated leukemias (AUL) and mixed-phenotype acute leukemias (MPAL). In the revised fourth edition of the World Health Organization (WHO) classification provided further refinements to the diagnostic criteria for ALAL. Molecular characterization of MPALs using comprehensive next-generation sequencing (NGS) has provided insights into their underlying biology and enabled a deeper understanding of ALAL classification. This review addresses the various components of pathologic assessment to establish a diagnosis of ALAL, and to further subclassify individual cases as AUL or MPAL, with an emphasis on the most up-to-date revisions to diagnostic criteria. In addition, key issues related to the detection of minimal residual disease (MRD) in ALALs and MPALs, and recently uncovered novel molecular diagnostic findings that may be helpful in better distinguishing various types of MPALs from each other, and from their "non-mixed" phenotypic correlates, are also discussed.

4.
Int J Pediatr Otorhinolaryngol ; 132: 109905, 2020 Jan 25.
Artigo em Inglês | MEDLINE | ID: mdl-32035348

RESUMO

INTRODUCTION: Idiopathic facial nerve palsy (FNP) is an uncommon but important presentation in children, with Lyme disease known to be a common cause. The UK county of Hampshire is a high incidence area of Lyme disease. We conducted a retrospective review of the investigation and management of paediatric FNP at a large University hospital, including serologic testing and treatment of Lyme disease. METHODS: We conducted a retrospective chart review of children under 18 presenting between January 1st, 2010 and December 31st, 2017 with a diagnosis of FNP. Patients with clear non-Lyme aetiology at presentation were excluded. Data was collected on demographics, initial presentation, investigations including Lyme serology, and management. RESULTS: A total of 93 children were identified, with an even proportion of male to female and median age 9.3 years (IQR 4.6-12 years). A history of rash was present in 5.4%, tick bite in 14% and recent travel to, or residence in the New Forest in 22.6%. Lyme serology was performed in 81.7% of patients, of which 29% were positive. Antibiotics were prescribed for 73.1% of patients, oral steroids for 44% and aciclovir for 17.2%. CONCLUSION: Lyme disease is a significant cause of FNP in this endemic area of the UK, and there was a large degree of variability in management prior to national guideline publication. Areas with endemic Lyme disease should consider introducing local guidelines supporting routine investigation and management for FNP, including empiric treatment for Lyme disease in accordance with NICE guidelines to improve care and reduce variability.

5.
Br J Gen Pract ; 70(692): e172-e178, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-32041764

RESUMO

BACKGROUND: Consultations for self-limiting infections in children are increasing. It has been proposed that digital technology could be used to enable parents' decision making in terms of self-care and treatment seeking. AIM: To evaluate the evidence that digital interventions facilitate parents deciding whether to self-care or seek treatment for acute illnesses in children. DESIGN AND SETTING: Systematic review of studies undertaken worldwide. METHOD: Searches of MEDLINE and EMBASE were made to identify studies (of any design) published between database inception and January 2019 that assessed digital interventions for parents of children (from any healthcare setting) with acute illnesses. The primary outcome of interest was whether the use of digital interventions reduced the use of urgent care services. RESULTS: Three studies were included in the review. They assessed two apps and one website: Children's On-Call - a US advice-only app; Should I See a Doctor? - a Dutch self-triage app for any acute illness; and Strategy for Off-Site Rapid Triage (SORT) for Kids - a US self-triage website for influenza-like illness. None of the studies involved parents during intervention development and it was shown that many parents did not find the two apps easy to use. The sensitivity of self-triage interventions was 84% for Should I See a Doctor? compared with nurse triage, and 93.3% for SORT for Kids compared with the need for emergency-department intervention; however, both had lower specificity (74% and 13%, respectively). None of the interventions demonstrated reduced use of urgent-care services. CONCLUSION: There is little evidence to support the use of digital interventions to help parent and/or carers looking after children with acute illness. Future research should involve parents during intervention development, and adequately powered trials are needed to assess the impact of such interventions on health services and the identification of children who are seriously ill.

6.
Crit Care Resusc ; 22(1): 26-34, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-32102640

RESUMO

BACKGROUND: Patients with prolonged cardiac arrest that is not responsive to conventional cardiopulmonary resuscitation have poor outcomes. The use of extracorporeal membrane oxygenation (ECMO) in refractory cardiac arrest has shown promising results in carefully selected cases. We sought to validate the results from an earlier extracorporeal cardiopulmonary resuscitation (ECPR) study (the CHEER trial). METHODS: Prospective, consecutive patients with refractory in-hospital (IHCA) or out-of-hospital cardiac arrest (OHCA) who met predefined inclusion criteria received protocolised care, including mechanical cardiopulmonary resuscitation, initiation of ECMO, and early coronary angiography (if an acute coronary syndrome was suspected). RESULTS: Twenty-five patients were enrolled in the study (11 OHCA, 14 IHCA); the median age was 57 years (interquartile range [IQR], 39-65 years), and 17 patients (68%) were male. ECMO was established in all patients, with a median time from arrest to ECMO support of 57 minutes (IQR, 38-73 min). Percutaneous coronary intervention was performed on 18 patients (72%). The median duration of ECMO support was 52 hours (IQR, 24-108 h). Survival to hospital discharge with favourable neurological recovery occurred in 11/25 patients (44%, of which 72% had IHCA and 27% had OHCA). When adjusting for lactate, arrest to ECMO flow time was predictive of survival (odds ratio, 0.904; P = 0.035). CONCLUSION: ECMO for refractory cardiac arrest shows promising survival rates if protocolised care is applied in conjunction with predefined selection criteria.


Assuntos
Reanimação Cardiopulmonar/métodos , Oxigenação por Membrana Extracorpórea , Parada Cardíaca/terapia , Reperfusão Miocárdica , Parada Cardíaca Extra-Hospitalar/terapia , Adulto , Idoso , Reanimação Cardiopulmonar/mortalidade , Oxigenação por Membrana Extracorpórea/efeitos adversos , Feminino , Parada Cardíaca/diagnóstico , Humanos , Masculino , Pessoa de Meia-Idade , Parada Cardíaca Extra-Hospitalar/mortalidade , Estudos Prospectivos , Estudos Retrospectivos , Taxa de Sobrevida , Resultado do Tratamento
7.
Bioresour Technol ; 302: 122887, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32018086

RESUMO

Immobilization of industrially important enzymes on supports is important to decrease the cost of the overall enzymatic production procedure. Herein, a novel method for synthesizing a new support, magnetic rice straw (MRS) in one step is reported: rice straw (RS) was soaked with Fe2+ ions and these were further reduced to form embedded Fe2O3 nanoparticles on the RS surface, forming MRS. This material presented a magnetic saturation value of 27.32 emu g-1. Lipase immobilization on MRS resulted in 94.3% immobilization efficiency and 91.3 mg g-1 of enzyme loading, which are higher than immobilization on native RS. The lipase stability was increased approximately 8-fold at 70 °C. The lipase-MRS composite was tested in the esterification reaction of biodiesel production, where it showed prominent reusability. Therefore, this novel and rapid synthesis method can provide ecological and economic support for enzyme immobilization and industrially important product formation.


Assuntos
Lipase , Oryza , Estabilidade Enzimática , Enzimas Imobilizadas , Esterificação , Fenômenos Magnéticos
8.
Mod Pathol ; 2020 Feb 12.
Artigo em Inglês | MEDLINE | ID: mdl-32051557

RESUMO

Ancillary testing during the initial workup of acute myeloid leukemia (AML) is largely performed using aspirated materials. We utilized multiplex immunofluorescence (MIF) imaging with digital image analysis to perform an in situ analysis of the microenvironment in NPM1-mutated AML using diagnostic bone marrow biopsy tissues (N = 17) and correlated these findings with diagnostic next-generation sequencing (NGS, N = 17), flow cytometry (FC, N = 14), and first remission (CR1) NPM1-specific molecular MRD (n = 16) data. The total CD3-positive T-cell percentages correlated positively between FC and MIF (r = 0.53, p = 0.05), but were significantly lower by MIF (1.62% vs. 3.4%, p = 0.009). The percentage of mutant NPM1-positive (NPM1c+) cells ranged from 9.7 to 90.8% (median 45.4%) and did not correlate with the NPM1 mutant allele fraction by NGS (p > 0.05). The percentage of CD34+/NPM1c+ cells ranged from 0 to 1.8% (median 0.07%). The percentage of NPM1c+ cells correlated inversely (34% vs. 62%, p = 0.03), while the percentages of CD3-/NPM1c- cells (64% vs. 35%, p = 0.03), and specifically CD3-/CD4-/NPM1c- cells (26% vs. 13%, p = 0.04), correlated positively with subsequent MRD. Discordances between MIF and FC/NGS data suggest that aspirate materials are likely an imperfect reflection of the core biopsy tissue. Furthermore, increased numbers of NPM1 wild-type cells within the microenvironment at diagnosis correlate with the subsequent presence of MRD.

9.
Am J Respir Crit Care Med ; 201(3): P5-P6, 2020 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-32003593
11.
Bioresour Technol ; 304: 123022, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32070839

RESUMO

Type I (Methylomicrobium album) and II (Methyloferula stellata) methanotrophs were encapsulated by alginate and polyvinyl alcohol (PVA) to improve methanol production from simulated biogas [methane (CH4) and carbon dioxide (CO2)] in the presence of CH4 vector. Polymeric matrix alginate (2%) and PVA (10%) were found to be optimum for the immobilization of both the methanotrophs, with a relative efficiency of methanol production up to 80.6 and 88.7%, respectively. The stability of methanol production by immobilized cells was improved up to 13.2-fold under repeated batch-culture over free cells. The addition of CH4 vectors showed 1.7-fold higher methanol production on using simulated biogas than in the control. The maximum methanol production of 7.46 and 7.14 mmol/L was noted for PVA-encapsulated M. album and M. stellata, respectively. This study successfully established the beneficial effects of CH4 vectors on methanol production by methanotrophs from greenhouse gases that can be applied for real biogas feedstock.


Assuntos
Metano , Methylococcaceae , Biocombustíveis , Metanol , Polímeros
12.
J Urol ; : 101097JU000000000000069801, 2020 Feb 03.
Artigo em Inglês | MEDLINE | ID: mdl-32011201
13.
Blood Adv ; 4(1): 122-126, 2020 Jan 14.
Artigo em Inglês | MEDLINE | ID: mdl-31917843

RESUMO

Disease relapse remains the leading cause of failure after autologous stem cell transplantation (ASCT) for patients with relapsed/refractory diffuse large B-cell lymphoma (R/R DLBCL). We conducted a phase 2, multicenter, single-arm study of the anti-PD-1 monoclonal antibody pembrolizumab given after ASCT in patients with chemosensitive DLBCL, hypothesizing that it would improve the progression-free survival (PFS) at 18 months after ASCT (primary endpoint) from 60% to 80%. Pembrolizumab was administered at 200 mg IV every 3 weeks for up to 8 cycles, starting within 21 days of post-ASCT discharge. Twenty-nine patients were treated on this study; 62% completed all 8 cycles. Seventy-nine percent of patients experienced at least one grade 3 or higher adverse event, and 34% experienced at least one grade 2 or higher immune-related adverse event. Overall, 59% of patients were alive and progression free at 18 months, which did not meet the primary endpoint. The 18-month overall survival was 93%. In conclusion, pembrolizumab was successfully administered as post-ASCT consolidation in patients with R/R DLBCL, but the PFS did not meet the protocol-specific primary objective and therefore does not support a larger confirmatory study. This trial was registered at www.clinicaltrials.gov as #NCT02362997.

14.
Clin J Am Soc Nephrol ; 15(2): 182-190, 2020 Feb 07.
Artigo em Inglês | MEDLINE | ID: mdl-31969341

RESUMO

BACKGROUND AND OBJECTIVES: In the general population, sleep disorders are associated with mortality. However, such evidence in patients with CKD and ESKD is limited and shows conflicting results. Our aim was to examine the association of sleep apnea with mortality among patients with CKD and ESKD. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: In this prospective cohort study, 180 patients (88 with CKD stage 4 or 5, 92 with ESKD) underwent in-home polysomnography, and sleep apnea measures such as apnea hypopnea index (AHI) and nocturnal hypoxemia were obtained. Mortality data were obtained from the National Death Index. Cox proportional hazard models were used for survival analysis. RESULTS: Among the 180 patients (mean age 54 years, 37% women, 39% with diabetes, 49% CKD with mean eGFR 18±7 ml/min per 1.73 m2), 71% had sleep apnea (AHI>5) and 23% had severe sleep apnea (AHI>30). Median AHI was 13 (range, 4-29) and was not significantly different in patients with advanced CKD or ESKD. Over a median follow-up of 9 years, there were 84 (47%) deaths. AHI was not significantly associated with mortality after adjusting for age, sex, race, diabetes, body mass index, CKD/ESKD status, and kidney transplant status (AHI>30: hazard ratio [HR], 1.5; 95% confidence interval [95% CI], 0.6 to 4.0; AHI >15 to 30: HR, 2.3; 95% CI, 0.9 to 5.9; AHI >5 to 15: HR, 2.1; 95% CI, 0.8 to 5.4, compared with AHI≤5). Higher proportion of sleep time with oxygen saturation <90% and lower mean oxygen saturation were significantly associated with higher mortality in adjusted analysis (HR, 1.4; 95% CI, 1.1 to 1.7; P=0.007 for every 15% higher proportion, and HR, 1.6; 95% CI, 1.2 to 2.1; P=0.003 for every 2% lower saturation, respectively). Sleep duration, sleep efficiency, or periodic limb movement index were not associated with mortality. CONCLUSIONS: Hypoxemia-based measures of sleep apnea are significantly associated with increased risk of death among advanced CKD and ESKD.

15.
Redox Biol ; 29: 101409, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31926617

RESUMO

Atherosclerosis is a chronic inflammatory disease of the vasculature characterised by the infiltration of activated neutrophils and macrophages at sites of damage within the vessel wall, which contributes to lesion formation and plaque progression. Selenomethionine (SeMet) is an organic form of selenium (Se), an essential trace element that functions in the regulation of the immune response by both bolstering the endogenous thioredoxin and glutathione antioxidant defence systems and by directly scavenging damaging oxidant species. This study evaluated the effect of dietary SeMet supplementation within a high fat diet fed apolipoprotein E deficient (ApoE-/-) mouse model of atherosclerosis. Dietary supplementation with SeMet (2 mg/kg) increased the tissue concentration of Se, and the expression and activity of glutathione peroxidase, compared to non-supplemented controls. Supplementation with SeMet significantly reduced atherosclerotic plaque formation in mouse aortae, resulted in a more stable lesion phenotype and improved vessel function. Concurrent with these results, SeMet supplementation decreased lesion accumulation of M1 inflammatory type macrophages, and decreased the extent of extracellular trap release from phorbol myristate acetate (PMA)-stimulated mouse bone marrow-derived cells. Importantly, these latter results were replicated within ex-vivo experiments on cultured neutrophils isolated from acute coronary syndrome patients, indicating the ability of SeMet to alter the acute inflammatory response within a clinically-relevant setting. Together, these data highlight the potential beneficial effect of SeMet supplementation as a therapeutic strategy for atherosclerosis.

16.
Artigo em Inglês | MEDLINE | ID: mdl-31986566

RESUMO

Quorum sensing (QS) mediated infections cause severe diseases in human beings. The control of infectious diseases by inhibiting QS using antipathogenic drugs is a promising approach as antibiotics are proving inefficient in treating these diseases. Marine fungal (Pestalotiopsis sydowiana PPR) extract was found to possess effective antipathogenic characteristics. The minimum inhibitory concentration (MIC) of the fungal extract against test pathogen Pseudomonas aeruginosa PAO1 was 1000 µg/mL. Sub-MIC concentrations (250 and 500 µg/mL) of fungal extract reduced the QS regulated virulence phenotypes such as the production of pyocyanin, chitinase, protease, elastase, and staphylolytic activity in P. aeruginosa PAO1 by 84.15%, 73.15%, 67.37%, 62.37%, and 33.65%, respectively. Moreover, it also reduced the production of exopolysaccharides (74.99%), rhamnolipid (68.01%), and alginate (54.98%), and inhibited the biofilm formation of the bacteria by 90.54%. In silico analysis revealed that the metabolite of P. sydowiana PPR binds to the bacterial QS receptor proteins (LasR and RhlR) similar to their respective natural signalling molecules. Cyclo(-Leu-Pro) (CLP) and 4-Hydroxyphenylacetamide (4-HPA) were identified as potent bioactive compounds among the metabolites of P. sydowiana PPR using in silico approaches. The MIC values of CLP and 4-HPA against P. aeruginosa PAO1 were determined as 250 and 125 µg/mL, respectively. All the antivirulence assays were conducted at sub-MIC concentrations of CLP (125 µg/mL) and 4-HPA (62.5 µg/mL), which resulted in marked reduction in all the investigated virulence factors. This was further supported by gene expression studies. The findings suggest that the metabolites of P. sydowiana PPR can be employed as promising QS inhibitors that target pathogenic bacteria.

17.
Ann Am Thorac Soc ; 17(4): 474-483, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31922899

RESUMO

Rationale: Although both type 2 diabetes mellitus (T2DM) and obstructive sleep apnea (OSA) are independently recognized as risk factors for cardiovascular disease, little is known about their interaction.Objectives: We hypothesized that T2DM and OSA act synergistically to increase vascular risk, and that treatment of OSA would improve vascular reactivity in patients with T2DM plus OSA.Methods: Cross-sectional study of 141 adults with T2DM, OSA, T2DM plus OSA, and control subjects, followed by a 3-month, parallel-arm, randomized, placebo-controlled trial comparing active and sham continuous positive airway pressure (CPAP) in 53 adults with T2DM plus OSA. Endothelium-dependent macro- and microvascular reactivity (flow-mediated dilation [FMD] of the brachial artery and acetylcholine-induced dilation of forearm microvasculature, respectively) and cardiovascular magnetic resonance to assess left- and right-ventricular mass/volume.Results: Mean (±SD) FMD was 6.1 (±4.0)%, 7.3 (±3.6)%, 6.8 (±4.5)%, and 4.8 (±2.9)% in control subjects, T2DM only, OSA only, and T2DM plus OSA, respectively. We observed a significant T2DM × OSA interaction on FMD, such that the mean effect of OSA in those with T2DM was 3.1% (95% confidence interval [CI], 0.6 to 5.6) greater than the effect of OSA in those without T2DM. A total of 3 months of CPAP resulted in a mean absolute increase in FMD of 0.3% (95% CI, -1.9 to 2.5; primary endpoint), with a net improvement of 1.1% (95% CI, -1.4 to 3.6) among those with adherence of 4 h/night or greater. A significant T2DM × OSA interaction was found for both left ventricular (LV) and right ventricular end-diastolic volume, such that OSA was associated with a 22.4 ml (95% CI, 3.2 to 41.6) greater LV end-diastolic volume and 23.2 ml (95% CI, 2.6 to 43.8) greater right ventricular end-diastolic volume in those with T2DM compared with the impact of OSA in those without T2DM. We observed a net improvement in LV end-diastolic volume of 8.7 ml (95% CI, -7.0 to 24.4).Conclusions: The combination of T2DM plus OSA is associated with macrovascular endothelial dysfunction beyond that observed with either disease alone. CPAP for 3 months did not significantly improve macrovascular endothelial function in the intent-to-treat analysis; however, cardiovascular magnetic resonance results suggest that there may be a beneficial effect of CPAP on LV diastolic volume.Clinical trial registered with www.clinicaltrials.gov (NCT01629862).

18.
Ophthalmology ; 127(3): 315-323, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31685256

RESUMO

PURPOSE: To determine if Scheimpflug tomography pachymetry map and posterior elevation map patterns, central corneal thickness (CCT), and corneal backscatter can predict the prognosis of Fuchs endothelial corneal dystrophy (FECD). DESIGN: Cross-sectional study with follow-up of outcomes. PARTICIPANTS: Ninety-six eyes (56 subjects) with a range of severity of FECD. METHODS: Corneas were graded by cornea specialists according to the area and confluence of guttae and the presence of clinically definite edema. Masked and randomized Scheimpflug imaging pachymetry map and posterior elevation map patterns were assessed by 1 observer for loss of regular isopachs, displacement of the thinnest point of the cornea, and the presence of posterior surface depression. The prognosis of eyes over a 5-year (median) follow-up period was determined based on FECD progression (new onset of clinically definite edema or ≥5% increase in CCT) or intervention by endothelial keratoplasty. Cumulative probabilities of progression and intervention were estimated from survival analyses, with risk factors determined by using Cox proportional hazards models. MAIN OUTCOME MEASURES: Pachymetry map and posterior elevation map patterns, corneal backscatter, and CCT (ultrasonic pachymetry). RESULTS: In univariate analyses, loss of regular isopachs (hazard ratio [HR], 18.00) displacement of the thinnest point (HR, 11.53), focal posterior surface depression (HR, 10.21), and anterior corneal backscatter (HR, 1.22, per 1-grayscale unit increment), were risk factors for progression or intervention (P < 0.001), whereas CCT (HR, 1.30, per 25-µm increment) was not (P = 0.15). In multivariate analyses, loss of regular isopachs (HR, 11.57; P < 0.001) and displacement of the thinnest point (HR, 5.61; P = 0.02) were independent and clinically important risk factors for progression and intervention. The 5-year cumulative risk of disease progression and intervention was 7%, 48%, and 89% when none, 1 or 2, and all 3 pachymetry map and posterior elevation map parameters were present, respectively (P <0.001). The 4-year cumulative risk of disease progression and intervention after uncomplicated cataract surgery was 0%, 50%, and 75% when none, 1 or 2, and all 3 pachymetry map and posterior elevation map parameters were present, respectively (P < 0.001). CONCLUSIONS: Three Scheimpflug tomography pachymetry map and posterior elevation map patterns can predict FECD prognosis independent of CCT. The risk of FECD progression and intervention, including after uncomplicated cataract surgery, increases according to the number of parameters present.

19.
Bioresour Technol ; 297: 122433, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31761623

RESUMO

This study aimed to establish a unique approach for the production of methanol from methane (CH4) in the presence of paraffin oil mediated by methanotrophs immobilized on coconut coir (CC). Immobilization of different methanotrophs through covalent method increased the immobilization yield and relative efficiency for methanol production to 48.6% and 96.8%, respectively. In the presence of paraffin oil, methanol production was 1.6-fold higher by Methylocystis bryophila than by control. Compared to free cells, whole cells immobilized on CC showed higher stability for methanol production. Under repeated batch conditions, cumulative methanol production by immobilized cells and free cells, after eight cycles of reuse, was 52.9 and 30.9 mmol/L, respectively. This study effectively demonstrated the beneficial influence of lignocellulosic biowaste CC as support for immobilization of methanotrophs and paraffin oil on bioconversion of CH4 to methanol.


Assuntos
Metano , Metanol , Biotransformação , Cocos , Lignina/análogos & derivados
20.
Transplantation ; 104(3): 482-489, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31568396

RESUMO

BACKGROUND: The optimal method of oxygen delivery to donor kidneys during ex vivo machine perfusion has not been established. We have recently reported the beneficial effects of subnormothermic (22°C) blood perfusion in the preservation of porcine donation after circulatory death kidneys. Since using blood as a clinical perfusate has limitations, including matching availability and potential presence of pathogen, we sought to assess hemoglobin-based oxygen carrier (HBOC-201) in oxygen delivery to the kidney for renal protection. METHODS: Pig kidneys (n = 5) were procured after 30 minutes of warm in situ ischemia by cross-clamping the renal arteries. Organs were flushed with histidine tryptophan ketoglutarate solution and subjected to static cold storage or pulsatile perfusion with an RM3 pump at 22°C for 4 hours with HBOC-201 and blood. Thereafter, kidneys were reperfused with normothermic (37°C) oxygenated blood for 4 hours. Blood and urine were subjected to biochemical analysis. Total urine output, urinary protein, albumin/creatinine ratio, flow rate, resistance were measured. Acute tubular necrosis, apoptosis, urinary kidney damage markers, neutrophil gelatinase-associated lipocalin 1, and interleukin 6 were also assessed. RESULTS: HBOC-201 achieved tissues oxygen saturation equivalent to blood. Furthermore, upon reperfusion, HBOC-201 treated kidneys had similar renal blood flow and function compared with blood-treated kidneys. Histologically, HBOC-201 and blood-perfused kidneys had vastly reduced acute tubular necrosis scores and degrees of terminal deoxynucleotidyl transferase 2'-deoxyuridine, 5'-triphosphate nick end labeling staining versus kidneys treated with cold storage. Urinary damage markers and IL6 levels were similarly reduced by both blood and HBOC-201. CONCLUSIONS: HBOC-201 is an excellent alternative to blood as an oxygen-carrying molecule in an ex vivo subnormothermic machine perfusion platform in kidneys.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA