6,203 research outputs found
Relapse of atypical hemolytic uremic syndrome during pregnancy in a patient on eculizumab maintenance treatment: A case report
Objective: Rare disease Background: Atypical hemolytic uremic syndrome (aHUS) is a genetic disorder with uncontrolled complement activation leading to systemic thrombotic microangiopathy; kidneys are almost invariably involved. Eculizumab has dramatically improved the prognosis of aHUS and affected women in the childbearing age are more likely to consider pregnancy, even if this could represent a risk for disease reactivation. Pregnancies in women with aHUS during Eculizumab treatment have been reported, with no cases of aHUS relapse. Case Report: We report the case of a female patient affected by aHUS with no specific gene mutations who had a pregnancyassociated aHUS relapse at 26-weeks of gestation during maintenance Eculizumab treatment. The patient developed stage II acute kidney injury and microangiopathic hemolytic anemia. Delivery by cesarean section at week 27, plasma exchange sessions and several supplemental Eculizumab administrations were required. After appropriate treatment, the patient partially recovered kidney function; the baby had a prolonged stay in the intensive care unit and showed no signs of neurologic damage. Conclusions: Previous reports indicated that pregnancy-related aHUS relapses were unlikely in women undergoing Eculizumab treatment. Based on our case, we suggest caution in counselling pregnancy in women with aHUS treated with Eculizumab, especially in the absence of pathogenic mutations in complement-regulating genes. Clinicians should be aware of possible aHUS relapse in pregnancy during Eculizumab treatment
Characterization of entomopathogenic nematodes and symbiotic bacteria active against Spodoptera frugiperda (Lepidoptera: Noctuidae) and contribution of bacterial urease to the insecticidal effect.
Rhodococcus equi Pneumonia in Kidney Transplant Recipient Affected by Acute Intermittent Porphyria: A Case Report
Rhodococcus equi is a gram-positive coccobacillus responsible for severe infections in patients with weakened immune systems. R equi generally causes pnumonia that may evolve into fatal systemic infection if left untreated. Here, we present a case of a 67-year-old woman affected by acute intermittent porphyria (AIP) who developed R equi pneumonia 7 months after kidney transplant. Although clinical features at presentation were nonspecific, lung computed tomography showed right perihilar consolidation with a mass-like appearance causing bronchial obstruction. Appropriate antibiotic including intravenous meropenem and oral azithromycin that was then switched to oral levofloxacin and oral azithromycin along with reduction of immunosuppressive therapy resolved pneumonia without provoking an acute attack of porphyria. AIP limited the choice of antibiotics for the treatment of R equi infection because some potentially porphyrinogenic antibacterial agents were avoided. Based on this experience, azithromycin and meropenem can be safely administered for the treatment of R Equi infection in patients with AIP
Anticorrosion Protection by Amine-Ionic Liquid Mixtures: Experiments and Simulations
The mixtures of aqueous amines and ionic liquids (ILs) are considered as potential solvents for CO2 capture. We report corrosion and CO2 absorption behavior of the mixed IL-amine solutions. The absorption tests were performed at 318.15 K under 0.1-2.7 MPa. The corrosion tests were carried out at 318.15 K under 2.7 MPa. Addition of [bmim][BF4] in aqueous alkanolamine solutions reduces corrosion rate for MEA by up to 72%. The CO, absorption capacity in the mixtures falls between those of aqueous MDEA and pure IL. These results allow to choose the working pressure range as a function of other parameters, such as gas pressure and mixture viscosity. According to the simulations, [bmim][BF4] participates in the gas capture through H-bonding, although the number of amine molecules is enough to capture all supplied CO, molecules. The equilibrium of the chemisorption reaction is, therefore, modified upon the stepwise IL addition. An ideal IL content for preventing corrosion is 10% w/w.CNPqHewlett-Packard Brasil LtdaCAPESPontif Catholic Univ Rio Grande Sul PUCRS, Postgrad Program Mat Engn & Technol, Ave Ipiranga 6681, BR-90619900 Porto Alegre, RS, BrazilPontif Catholic Univ Rio Grande Sul PUCRS, Sch Chem, Ave Ipiranga 6681, BR-90619900 Porto Alegre, RS, BrazilPontif Catholic Univ Rio Grande Sul PUCRS, Sch Engn, Ave Ipiranga 6681, BR-90619900 Porto Alegre, RS, BrazilUniv Fed Sao Paulo, BR-04021001 Sao Paulo, SP, BrazilUniv Fed Sao Paulo, BR-04021001 Sao Paulo, SP, BrazilWeb of Scienc
Beam test calibration of the balloon-borne imaging calorimeter for the CREAM experiment
CREAM (Cosmic Ray Energetics And Mass) is a multi-flight balloon mission
designed to collect direct data on the elemental composition and individual
energy spectra of cosmic rays. Two instrument suites have been built to be
flown alternately on a yearly base. The tungsten/Sci-Fi imaging calorimeter for
the second flight, scheduled for December 2005, was calibrated with electron
and proton beams at CERN. A calibration procedure based on the study of the
longitudinal shower profile is described and preliminary results of the beam
test are presented.Comment: 4 pages, 4 figures. To be published in the Proceedings of 29th
International Cosmic Ray Conference (ICRC 2005), Pune, India, August 3-10,
200
Clinical outcome of kidney transplantation in HIV-infected recipients: a retrospective study
Kidney transplantation is a safe and effective option for HIV-positive (HIV+) patients. We conducted a retrospective study on HIV+ kidney transplant recipients who underwent transplantation from March 2008 to September 2016.Inclusion criteria for transplantation were CD4þ T-cell count 200 per mm3 and undetectable HIV load. The current study reports the outcome of 19 HIV+ recipients, mostly of Caucasian origin (79%) with a median age of 50 years (interquartile range [IQR], 42–52), who were followed up for a median period of 2.4 years (IQR, 1.2–4.6) after transplantation. Compared with HIV-negative (HIV-) controls, HIV+ recipients had similar one- and three-year graft and patient survival, but significantly lower five-year patient survival (P¼0.03). The differences in graft outcome became less
evident with the analysis of death-censored graft survival rates. Cumulative incidence of allograft rejection at one year was 32.9%. Rates of infections were not particularly elevated and HIV replication remained well controlled in all but one patient. A high prevalence of metabolic and endocrine complications (68%) was reported after transplantation. Further studies are needed to evaluate long-term outcomes of HIV+ recipients who underwent kidney transplantation
Characterization of JBURE-IIb isoform of Canavalia ensiformis (L.) DC urease.
Ureases, nickel-dependent enzymes that catalyze the hydrolysis of urea into ammonia and bicarbonate, are widespread in plants, bacteria, and fungi. Previously, we cloned a cDNA encoding a Canavalia ensiformis urease isoform named JBURE-II, corresponding to a putative smaller urease protein (78 kDa) when compared to other plant ureases. Aiming to produce the recombinant protein, we obtained jbure-IIb, with different 3? and 5? ends, encoding a 90 kDa urease. Three peptides unique to the JBURE-II/-IIb protein were detected by mass spectrometry in seed extracts, indicating that jbure-II/-IIb is a functional gene. Comparative modeling indicates that JBURE-IIb urease has an overall shape almost identical to C. ensiformis major urease JBURE-I with all residues critical for urease activity. The cDNA was cloned into the pET101 vector and the recombinant protein was produced in Escherichia coli. The JBURE-IIb protein, although enzymatically inactive presumably due to the absence of Ni atoms in its active site, impaired the growth of a phytopathogenic fungus and showed entomotoxic properties, inhibiting diuresis of Rhodnius prolixus isolated Malpighian tubules, in concentrations similar to those reported for JBURE-I and canatoxin. The antifungal and entomotoxic properties of the recombinant JBURE-IIb apourease are consistent with a protective role of ureases in plants
In vitro efficacy and safety of a system for sorbent-assisted peritoneal dialysis
In vitro efficacy and safety of a system for sorbent-assisted peritoneal dialysis. Am J Physiol Renal Physiol 319: F162-F170, 2020. First published June 1, 2020; doi:10.1152/ajprenal. 00079.2020.-A system for sorbent-assisted peritoneal dialysis (SAPD) was designed to continuously recirculate dialysate via a tidal mode using a single lumen peritoneal catheter with regeneration of spent dialysate by means of sorbent technology. We hypothesize that SAPD treatment will maintain a high plasma-to-dialysate concentration gradient and increase the mass transfer area coefficient of solutes. Thereby, the SAPD system may enhance clearance while reducing the number of exchanges. Application is envisaged at night as a bedside device (12 kg, nighttime system). A wearable system (2.0 kg, daytime system) may further enhance clearance during the day. Urea, creatinine, and phosphate removal were studied with the daytime and nighttime system (n = 3 per system) by recirculating 2 liters of spent peritoneal dialysate via a tidal mode (mean flow rate: 50 and 100 mL/min, respectively) for 8 h in vitro. Time-averaged plasma clearance over 24 h was modeled assuming one 2 liter exchange/day, an increase in mass transfer area coefficient, and 0.9 liters ultrafiltration/day. Urea, creatinine, and phosphate removal was 33.2 ± 4.1, 5.3 ± 0.5, and 6.2 ± 1.8 mmol, respectively, with the daytime system and 204 ± 28, 10.3 ± 2.4, and 11.4 ± 2.1 mmol, respectively, with the nighttime system. Time-averaged plasma clearances of urea, creatinine and phosphate were 9.6 ± 1.1, 9.6 ± 1.7, and 7.0 ± 0.9 mL/min, respectively, with the nighttime system and 10.8 ± 1.1, 13.4 ± 1.8, and 9.7 ± 1.6 mL/min, respectively, with the daytime and nighttime system. SAPD treatment may improve removal of uremic toxins compared with conventional peritoneal dialysis, provided that peritoneal mass transport will increase
Prolonged RT-PCR test positivity in hemodialysis patients with COVID-19
Background: The weakened immune system of patients on hemodialysis (HD) may prolong SARS-CoV-2 infection compared to the general population. Current international guidelines recommend ending isolation in conjunction with serial testing in moderately and severely immunocompromised subjects. This study aimed to estimate SARS-CoV-2 infectivity by measuring RT-PCR test positivity in HD patients. A comparison between RT-PCR test and cycle threshold (Ct) value has been performed as a secondary endpoint. Methods: A single-center retrospective study was conducted at the University of Modena (Italy) from March 2020 to October 2022. Only patients on chronic HD therapy with COVID-19 were enrolled in the study. In our HD Center, two negative nasopharyngeal reverse transcription polymerase chain reaction (RT-PCR) results were used to end quarantine in this population. SARS-CoV-2 RT-PCR test positivity duration measured the time elapsed from a positive RT-PCR to a second negative test. Ct cut-off of 35 cycles was used to definite “high Ct value,” a condition characterized by a large number of cycles of PCR amplification to register a positive RT-PCR test. Results: During the observational period, 159 cases of SARS-CoV-2 infections were diagnosed in 151 patients. Median age was 70.1 (54.3–81.6) years and males accounted for 59.6% of the COVID-19 population. Median duration of SARS-CoV-2 RT-PCR test positivity on the nasal mucosa accounted for 30 (IQR, 21–40.5) days. Unvaccinated patients experienced significantly longer RT-PCR test positivity compared to vaccinated patients (42 [IQR,31–56] vs. 28 [IQR,20–35.7] days; p = < 0.001). The use of high Ct value, a laboratory surrogate of SARS-CoV-2 replication, anticipated a negative RT-PCR test of 9 (IQR, 6–12) days. Multivariate linear regression analysis showed that increased age (β coefficient 0.31; confidence interval [CI] 95%, 0.14—0.43; p = < 0.001) and the lack of anti-SARS-CoV-2 vaccination (β 0.49 CI95%, 11.9–22.5; p = < 0.001) were predictors of a prolonged RT-PCR positivity. Conclusions: Patients with COVID-19 on HD had prolonged RT-PCR test positivity. The adoption of “high Ct value” criteria led to a significant reduction in the duration of RT-PCR test positivity compared to the use of the classical nucleic acid amplification test. In our study, the lack of SARS-CoV-2 vaccination and older age were independently associated with a longer RT-PCR positivity
Avaliação de um biossorvente à base de fibra de ráfia na sorção de hidrocarbonetos
Oil spills and discharges of petroleum products have severely polluted aquatic ecosystems, oceans, rivers, groundwater and even soil. In August 2019, more than 2,000 km of the northeast and southeast coast of Brazil were struck by a major oil spill in the country’s largest ever environmental disaster. Spill remediation is a significant environmental challenge and the economic and socioenvironmental impacts of these events are diverse. Oil spills in oceans and rivers severely affect the fishing and tourism industries of the areas in question, with damage including severe short and long-term effects on plants and animals, such as respiratory and digestive disorders, reduced growth and reproductive capacity as well as weakened immunity due to the bioaccumulation of toxic contaminants. There are several proposed strategies for removing crude oil and petroleum products from surface water. Contaminated areas can be remediated in-situ or ex-situ, with the former considered the best option in terms of cost and efficiency. In this respect, absorbent materials obtained from biomass have received widespread attention due to their ease of use, buoyancy and low cost. Raffia is a natural fiber abundant in eastern Africa with excellent physical properties, such as low specific weight, good liquid sorption and low conductivity. As such, the present study investigated the application of raffia fiber with different particle sizes (< 300 µm, 300 - 850 µm, 850 - 1000 µm, 1000 - 1400 µm and 1400 - 2000 µm) and fiber/hydrocarbon ratios (1, 2, 3 and 4% w/v) as an absorbent for hydrocarbons, using n-heptane as a model molecule. Microscopic analysis of micronized raffia fiber indicated the presence of honeycomb-shaped cells with well-defined borders and an irregular geometry. These honeycomb structures are preserved, especially in large particle size ranges. Among the granulometries assessed, the highest sorption capacities were obtained for 1000 to 1400 µm raffia fibers, suggesting that honeycomb-shaped structures favor hydrocarbon sorption. Additionally, the fact that smaller particles do not require micronization is economically beneficial and facilitates application of the absorbent material to remediate hydrocarbon-contaminated areas. The results obtained under the conditions studied indicate that sorption capacity increases as the absorbent content rises. Comparison of fiber contents of 1% and 3% w/v for 1000 - 1400 µm particles showed an increase of approximately 43% in sorption capacity when content rose to 3% w/v. The results of the present study demonstrate the potential of natural raffia fiber as an alternative absorbent for hydrocarbons.O derramamento de óleo e derivados de petróleo leva a graves efeitos de poluição em sistemas aquáticos, oceanos, rios e águas subterrâneas e, até mesmo, no solo. Recentemente, em agosto de 2019, mais de 2 mil quilômetros do litoral do Nordeste e Sudeste brasileiro foram atingidos por um grande derramamento de petróleo, caracterizando o maior desastre ambiental já ocorrido no Brasil. Um grande desafio ambiental é a remediação de incidentes envolvendo derramamento de óleo e derivados de petróleo. Os impactos econômicos e socioambientais desses incidentes são os mais diversos. Considerando os desastres de derramamento em áreas marítimas e fluviais, os danos podem gerar sérios problemas na indústria pesqueira ou até mesmo em atividades turísticas da região. Entre estes danos, efeitos gravíssimos em plantas e animais a curto e longo prazo, como problemas nos sistemas respiratório e digestivo, na capacidade de crescimento e reprodução e na imunidade devido aos processos de bioacumulação de contaminantes tóxicos. Atualmente, muitas abordagens são propostas para remoção de contaminantes de óleo e derivados de petróleo de superfícies aquosas. A remediação de áreas contaminadas pode ocorrer in-situ ou ex-situ, sendo que as tecnologias in-situ são sempre consideradas as melhores opções devido ao custo e eficiência. Com relação a isso, materiais absorventes provenientes de biomassa têm atraído muita atenção pela sua facilidade de utilização, pois normalmente possuem boa flutuabilidade e baixo custo. A ráfia é uma espécie de fibra natural encontrada em abundância na região ocidental da África e que possui propriedades físicas interessantes, como a baixa massa específica, boa sorção a líquidos e baixa condutividade. Dentro deste contexto, o presente trabalho estudou a aplicação da fibra natural de ráfia em diferentes faixas granulométricas (< 300 µm, 300 - 850 µm, 850 - 1000 µm, 1000 - 1400 µm e 1400 - 2000 µm) e em diferentes razões fibra/hidrocarboneto (1, 2, 3 e 4% m/v) como material absorvente para hidrocarbonetos, utilizando o n-heptano como molécula modelo. A análise microscópica da fibra de ráfia micronizada indica a presença de células formadas com fronteiras bem definidas e fechadas, mas com geometria irregular, cuja forma lembra uma colmeia de abelha. Essas estruturas de colmeia foram preservadas, principalmente nas maiores faixas granulométricas. Dentre as diferentes granulometrias avaliadas, as maiores capacidades de sorção foram obtidas com partículas de ráfia na faixa de 1000 - 1400 µm, sugerindo que a presença de estruturas na forma de colmeia favorece a sorção de hidrocarboneto. Além disso, o fato de não haver necessidade de micronizar a fibra em partículas muito finas, gera vantagens do ponto de vista econômico e de aplicação do material absorvente na remediação de áreas contaminadas por hidrocarbonetos. Os resultados obtidos nas condições estudadas indicam que a capacidade de sorção cresce à medida que a quantidade de absorvente aumenta. Comparando-se os teores de 1% e 3% m/v de ráfia, na faixa de 1000 - 1400 µm verificou-se um aumento de aproximadamente 43% na capacidade de sorção, quando o teor de fibra aumentou para 3% m/v. Os resultados do presente trabalho evidenciam a potencialidade da fibra natural de ráfia como material absorvente alternativo para hidrocarbonetos
- …