Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 250
Filtrar
1.
J Clin Microbiol ; 58(7)2020 06 24.
Artigo em Inglês | MEDLINE | ID: mdl-32321780

RESUMO

Group A streptococcus (GAS) species cause bacterial pharyngitis in both adults and children. Early and accurate diagnosis of GAS is important for appropriate antibiotic therapy to prevent GAS sequalae. The Revogene Strep A molecular assay (Meridian Bioscience Canada Inc, Quebec City, QC, Canada) is an automated real-time PCR assay for GAS detection from throat swab specimens within approximately 70 min. This multicenter prospective study evaluated the performance of the Revogene Strep A molecular assay compared to that of bacterial culture. Dual throat swab specimens in either liquid Amies or Stuart medium were collected from eligible subjects (pediatric population and adults) enrolled across 7 sites (USA and Canada). Revogene Strep A and reference testing was performed within 7 days and 48 h of sample collection, respectively. Of the 604 evaluable specimens, GAS was detected in 154 (25.5%) samples by the reference method and in 175 (29%) samples by the Revogene Strep A assay. Revogene Strep A assay sensitivity and specificity were reported to be 98.1% (95% confidence interval [CI], 94.4 to 99.3) and 94.7% (95% CI, 92.2 to 96.4), respectively. The positive predictive value was 86.3% (95% CI, 80.4 to 90.6), negative predictive value was 99.3% (95% CI, 98.0 to 99.8) with a 1.0% invalid rate. Discrepant analysis with alternative PCR/bidirectional sequencing was performed for 24 false-positive (FP) and 3 false-negative (FN) specimens. Concordant results were reported for 17 (FP only) of 27 discordant specimens. The Revogene Strep A assay had high sensitivity and specificity for GAS detection and provides a faster alternative for GAS diagnosis.


Assuntos
Faringite , Infecções Estreptocócicas , Adulto , Canadá , Criança , Humanos , Faringite/diagnóstico , Faringe , Estudos Prospectivos , Quebeque , Sensibilidade e Especificidade , Infecções Estreptocócicas/diagnóstico , Streptococcus pyogenes/genética
2.
Clin Exp Nephrol ; 24(3): 259-267, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31696378

RESUMO

BACKGROUND: A scarcity of organs has driven the transplant community to broaden selection criteria for both living and deceased donors. Living donor transplants offer better patient and allograft survival when compared with deceased donor transplants. Many transplant centers now allow complex living donors such as those with nephrolithiasis to undergo nephrectomy. METHODS: We conducted a survey of medical and surgical directors of kidney transplant programs in the United States to shed light on current practices pertaining to medical evaluation of living kidney donors with nephrolithiasis. 353 surveys were e-mailed to medical directors and surgical directors of transplant programs after contacts were obtained from UNOS. RESULTS: 49 completed surveys were returned (13.9%). 77.7% (38/49) of survey participants said their centers will consider living kidney donor candidates with a history of symptomatic kidney stones, 69.4% (34/49) said their centers will consider candidates who are incidentally found to have kidney stones and 10.2% (5/49) said their centers decline all potential donors with nephrolithiasis. CONCLUSIONS: Several programs are still reluctant to allow potential donors with nephrolithiasis to donate. There is an unmet need to develop evidence-based guidelines to optimize outcomes in this population of kidney donors with nephrolithiasis and their recipients.


Assuntos
Transplante de Rim/normas , Doadores Vivos , Nefrolitíase , Humanos , Transplante de Rim/estatística & dados numéricos , Programas Médicos Regionais/estatística & dados numéricos , Inquéritos e Questionários
3.
J Virol ; 92(5)2018 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-29237841

RESUMO

Influenza A viruses (IAVs) are common pathogens of birds that occasionally establish endemic infections in mammals. The processes and mechanisms that result in IAV mammalian adaptation are poorly understood. The viral nonstructural 1 (NS1) protein counteracts the interferon (IFN) response, a central component of the host species barrier. We characterized the NS1 proteins of equine influenza virus (EIV), a mammalian IAV lineage of avian origin. We showed that evolutionarily distinct NS1 proteins counteract the IFN response using different and mutually exclusive mechanisms: while the NS1 proteins of early EIVs block general gene expression by binding to cellular polyadenylation-specific factor 30 (CPSF30), NS1 proteins from more evolved EIVs specifically block the induction of IFN-stimulated genes by interfering with the JAK/STAT pathway. These contrasting anti-IFN strategies are associated with two mutations that appeared sequentially and were rapidly selected for during EIV evolution, highlighting the importance of evolutionary processes in immune evasion mechanisms during IAV adaptation.IMPORTANCE Influenza A viruses (IAVs) infect certain avian reservoir species and occasionally transfer to and cause epidemics of infections in some mammalian hosts. However, the processes by which IAVs gain the ability to efficiently infect and transmit in mammals remain unclear. H3N8 equine influenza virus (EIV) is an avian-origin virus that successfully established a new lineage in horses in the early 1960s and is currently circulating worldwide in the equine population. Here, we analyzed the molecular evolution of the virulence factor nonstructural protein 1 (NS1) and show that NS1 proteins from different time periods after EIV emergence counteract the host innate immune response using contrasting strategies, which are associated with two mutations that appeared sequentially during EIV evolution. The results shown here indicate that the interplay between virus evolution and immune evasion plays a key role in IAV mammalian adaptation.


Assuntos
Adaptação Fisiológica/genética , Adaptação Fisiológica/imunologia , Evolução Molecular , Evasão da Resposta Imune , Vírus da Influenza A/genética , Vírus da Influenza A/imunologia , Proteínas não Estruturais Virais/genética , Proteínas não Estruturais Virais/imunologia , Sequência de Aminoácidos , Animais , Sequência de Bases , Linhagem Celular , Fator de Especificidade de Clivagem e Poliadenilação/metabolismo , Citocinas/metabolismo , Cães , Regulação Viral da Expressão Gênica , Vetores Genéticos , Células HEK293 , Cavalos , Especificidade de Hospedeiro , Interações Hospedeiro-Patógeno/genética , Interações Hospedeiro-Patógeno/imunologia , Humanos , Imunidade Inata , Vírus da Influenza A Subtipo H3N8/imunologia , Vírus da Influenza A/patogenicidade , Interferon beta , Interferons/metabolismo , Janus Quinases , Células Madin Darby de Rim Canino , Mutação , Infecções por Orthomyxoviridae/virologia , Domínios e Motivos de Interação entre Proteínas , Fator de Transcrição STAT1/metabolismo , Alinhamento de Sequência , Transcriptoma , Proteínas não Estruturais Virais/química , Fatores de Virulência , Replicação Viral/genética
4.
Am J Transplant ; 16(4): 1276-84, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-26762606

RESUMO

Approximately 59 000 kidney transplant candidates have been removed from the waiting list since 2000 for reasons other than transplantation, death, or transfers. Prior studies indicate that low-performance (LP) center evaluations by the Scientific Registry of Transplant Recipients (SRTR) are associated with reductions in transplant volume. There is limited information to determine whether performance oversight impacts waitlist management. We used national SRTR data to evaluate outcomes of 315 796 candidates on the kidney transplant waiting list (2007-2014). Compared to centers without LP, rates of waitlist removal (WLR) were higher at centers with LP evaluations (44.6/1000 follow-up years, 95% confidence interval [CI] 44.0, 45.1 versus 68.0/1000 follow-up years, 95% CI 66.6, 69.4), respectively, which was consistent after risk adjustment (adjusted hazard ratio [AHR] = 1.59, 95% CI 1.55, 1.63). Candidate mortality following waitlist removal was lower at LP centers (AHR = 0.90, 95% CI 0.87, 0.94). Analyses limited to LP centers indicated a significant increase in WLR (+28.6 removals/1000 follow-up years, p < 0.001), a decrease in transplant rates (-11.9/1000 follow-up years, p < 0.001) and a decrease in mortality after removal (-67.5 deaths/1000 follow-up years, p < 0.001) following LP evaluation. There is a significant association between LP evaluations and transplant center processes of care for waitlisted candidates. Further understanding is needed to determine the impact of performance oversight on transplant center quality of care and patient outcomes.


Assuntos
Falência Renal Crônica/cirurgia , Transplante de Rim/normas , Avaliação de Processos e Resultados em Cuidados de Saúde/normas , Seleção de Pacientes , Indicadores de Qualidade em Assistência à Saúde/normas , Centros Cirúrgicos/estatística & dados numéricos , Centros Cirúrgicos/normas , Listas de Espera , Adolescente , Adulto , Idoso , Feminino , Seguimentos , Humanos , Transplante de Rim/estatística & dados numéricos , Masculino , Pessoa de Meia-Idade , Prognóstico , Avaliação de Programas e Projetos de Saúde , Transplantados , Adulto Jovem
5.
Phys Chem Chem Phys ; 18(28): 19037-49, 2016 Jul 28.
Artigo em Inglês | MEDLINE | ID: mdl-27355583

RESUMO

Methods based on pulse electron paramagnetic resonance allow measurement of the electron-electron dipolar coupling between two spin labels. Here we compare the most popular technique, Double Electron-Electron Resonance (DEER or PELDOR), with the dead-time free 5-pulse Relaxation-Induced Dipolar Modulation Enhancement (RIDME) method for Gd(iii)-Gd(iii) distance measurements at W-band (94.9 GHz, ≈3.5 T) using Gd(iii) tags with a small zero field splitting (ZFS). Such tags are important because of their high EPR sensitivity arising from their narrow central transition. Two systems were investigated: (i) a rigid model compound with an inter-spin distance of 2.35 nm, and (ii) two mutants of a homodimeric protein, both labeled with a DOTA-based Gd(iii) chelate and characterized by an inter-spin distance of around 6 nm, one having a narrow distance distribution and the other a broad distribution. Measurements on the model compound show that RIDME is less sensitive to the complications arising from the failure of the weak coupling approximation which affect DEER measurements on systems characterized by short inter-spin distances between Gd(iii) tags having a narrow central transition. Measurements on the protein samples, which are characterized by a long inter-spin distance, emphasize the complications due to the appearance of harmonics of the dipolar interaction frequency in the RIDME traces for S > 1/2 spin systems, as well as enhanced uncertainties in the background subtraction. In both cases the sensitivity of RIDME was found to be significantly better than DEER. The effects of the experimental parameters on the RIDME trace are discussed.

6.
Am J Transplant ; 15(9): 2394-403, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-25902877

RESUMO

Follow-up care for living kidney donors is an important responsibility of the transplant community. Prior reports indicate incomplete donor follow-up information, which may reflect both donor and transplant center factors. New UNOS regulations require reporting of donor follow-up information by centers for 2 years. We utilized national SRTR data to evaluate donor and center-level factors associated with completed follow-up for donors 2008-2012 (n = 30 026) using multivariable hierarchical logistic models. We compared center follow-up compliance based on current UNOS standards using adjusted and unadjusted models. Complete follow-up at 6, 12, and 24 months was 67%, 60%, and 50% for clinical and 51%, 40%, and 30% for laboratory data, respectively, but have improved over time. Donor risk factors for missing laboratory data included younger age 18-34 (adjusted odds ratio [AOR] = 2.03, 1.58-2.60), black race (AOR = 1.17, 1.05-1.30), lack of insurance (AOR = 1.25, 1.15-1.36), lower educational attainment (AOR = 1.19, 1.06-1.34), >500 miles to center (AOR = 1.78, 1.60-1.98), and centers performing >40 living donor transplants/year (AOR = 2.20, 1.21-3.98). Risk-adjustment moderately shifted classification of center compliance with UNOS standards. There is substantial missing donor follow-up with marked variation by donor characteristics and centers. Although follow-up has improved over time, targeted efforts are needed for donors with selected characteristics and at centers with higher living donor volume. Adding adjustment for donor factors to policies regulating follow-up may function to provide more balanced evaluation of center efforts.


Assuntos
Continuidade da Assistência ao Paciente/normas , Atenção à Saúde , Fidelidade a Diretrizes/normas , Transplante de Rim , Doadores Vivos , Adolescente , Adulto , Idoso , Feminino , Seguimentos , Humanos , Hipertensão , Masculino , Pessoa de Meia-Idade , Sistema de Registros , Obtenção de Tecidos e Órgãos , Estados Unidos , Adulto Jovem
7.
Phys Chem Chem Phys ; 17(8): 6053-65, 2015 Feb 28.
Artigo em Inglês | MEDLINE | ID: mdl-25640165

RESUMO

Dynamic Nuclear Polarization (DNP) experiments on solid dielectrics can be described in terms of the Solid Effect (SE) and Cross Effect (CE) mechanisms. These mechanisms are best understood by following the spin dynamics in electron-nuclear and electron-electron-nuclear model systems, respectively. Recently it was shown that the frequency swept DNP enhancement profiles can be reconstructed by combining basic SE and CE DNP spectra. However, this analysis did not take into account the role of the electron spectral diffusion (eSD), which can result in a dramatic loss of electron polarization along the EPR line. In this paper we extend the analysis of DNP spectra by including the influence of the eSD process on the enhancement profiles. We show for an electron-electron-nuclear model system that the change in nuclear polarization can be caused by direct MW irradiation on the CE electron transitions, resulting in a direct CE (dCE) enhancement, or by the influence of the eSD process on the spin system, resulting in nuclear enhancements via a process we term the indirect CE (iCE). We next derive the dependence of the basic SE, dCE, and iCE DNP spectra on the electron polarization distribution along the EPR line and on the MW irradiation frequency. The electron polarization can be obtained from ELDOR experiments, using a recent model which describes its temporal evolution in real samples. Finally, DNP and ELDOR spectra, recorded for a 40 mM TEMPOL sample at 10-40 K, are analyzed. It is shown that the iCE is the major mechanism responsible for the bulk nuclear enhancement at all temperatures.

8.
Phys Chem Chem Phys ; 17(1): 226-44, 2015 Jan 07.
Artigo em Inglês | MEDLINE | ID: mdl-25384575

RESUMO

Dynamic nuclear polarization is typically explained either using microscopic systems, such as in the solid effect and cross effect mechanisms, or using the macroscopic formalism of spin temperature which assumes that the state of the electrons can be described using temperature coefficients, giving rise to the thermal mixing mechanism. The distinction between these mechanisms is typically made by measuring the DNP spectrum - i.e. the nuclear enhancement profile as a function of irradiation frequency. In particular, we have previously used the solid effect and cross effect mechanisms to explain temperature dependent DNP spectra. Our past analysis has however neglected the effect of depolarization of the electrons resulting from the microwave (MW) irradiation. In this work we concentrate on this electron depolarization process and perform electron-electron double resonance (ELDOR) experiments on TEMPOL and trityl frozen solutions, using a 3.34 Tesla magnet and at 2.7-30 K, in order to measure the state of the electron polarization during DNP. The experiments indicate that a significant part of the EPR line is affected by the irradiation due to spectral diffusion. Using a theoretical framework based on rate equations for the polarizations of the different electron spin packets and for those of the nuclei we simulated the various ELDOR line-shapes and reproduced the MW frequency and irradiation time dependence. The obtained electron polarization distribution cannot be described using temperature coefficients as required by the classical thermal mixing mechanism, and therefore the DNP mechanism cannot be described by thermal mixing. Instead, the theoretical framework presented here for the analysis of the ELDOR data forms a basis for future interpretation of DNP spectra in combination with EPR measurements.

9.
Am J Transplant ; 14(12): 2855-60, 2014 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-25278446

RESUMO

The new allocation policy for deceased donor kidneys in the United States is expected to begin in late 2014. As part of this policy, prioritization to the highest quality deceased donor kidneys is dependent on candidate's estimated posttransplant survival (EPTS) score. In particular, candidates with low (≤20%) EPTS (indicating better estimated survival) will have greater access to donor offers. We evaluated the effect of dialysis initiation on preemptively listed candidates' EPTS score. Using current estimates, approximately 10% (n = 19,406) of candidates placed on the waiting list between 2008 and 2013 were listed preemptively and would have qualified for top 20% status. These patients were more likely younger, female, Caucasian and nondiabetic compared to other candidates. Among nondiabetic preemptively listed candidates, dialysis initiation decreases EPTS score (indicating better estimated survival and higher allocation priority) for approximately 5 months. In contrast, diabetic patients' EPTS score significantly increases (approximately 6%) immediately upon dialysis initiation. Our results reveal a counterintuitive aberration in the EPTS formula, which is important for decision making regarding organ selection and timing of dialysis initiation in the new allocation system. Revision of the EPTS formula should be considered to address these findings and further understanding of the impact of the new allocation system on candidates' prognosis is important.


Assuntos
Política de Saúde , Transplante de Rim , Seleção de Pacientes , Diálise Renal , Doadores de Tecidos , Obtenção de Tecidos e Órgãos/tendências , Adolescente , Adulto , Idoso , Feminino , Seguimentos , Sobrevivência de Enxerto , Humanos , Masculino , Pessoa de Meia-Idade , Fatores de Tempo , Obtenção de Tecidos e Órgãos/estatística & dados numéricos , Listas de Espera , Adulto Jovem
10.
Am J Transplant ; 14(6): 1356-67, 2014 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-24731101

RESUMO

As of November 2013, 14.5% of the waitlist for a donor kidney comprised patients awaiting a retransplant. We performed a retrospective cohort study of 11,698 adult solitary kidney recipients using national Scientific Registry of Transplant Recipients data transplanted between 2002 and 2011. The aim was to investigate whether outcomes from patients' initial transplants are significant risk factors for patients' repeat transplants or for likelihood of relisting after a failed primary transplant. Retransplant recipients were more likely to be treated for acute rejection [adjusted odds ratio (AOR), 95% confidence interval (CI) = 1.26 (1.07-1.48), p = 0.0053] or hospitalized (AOR = 1.19, 95% CI 1.08-1.31, p = 0.0005) within a year of retransplantation if these outcomes were experienced within a year of primary transplant. Delayed graft function following primary transplants was associated with 35% increased likelihood of recurrence (AOR = 1.35, 95% CI = 1.18-1.54, p < 0.0001). An increase in 1-year GFR after primary transplant was associated with GFR 1 year postretransplant (ß = 6.82, p < 0.0001), and retransplant graft failure was inversely associated with 1-year primary transplant GFR (adjusted hazard ratio = 0.74, 95% CI = 0.71-0.76 per 10 mL/min/1.73 m(2) ). A decreased likelihood for relisting was associated with hospitalization and higher GFR following primary transplantation. The increasing numbers of individuals requiring retransplants highlights the importance of incorporating prior transplant outcomes data to better inform relisting decisions and prognosticating retransplant outcomes.


Assuntos
Transplante de Rim , Reoperação , Resultado do Tratamento , Listas de Espera , Adolescente , Adulto , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Fatores de Risco , Adulto Jovem
11.
Phys Chem Chem Phys ; 16(36): 19218-28, 2014 Sep 28.
Artigo em Inglês | MEDLINE | ID: mdl-25096750

RESUMO

The microwave frequency swept DNP enhancement, referred to as the DNP spectrum, is strongly dependent on the EPR spectrum of the polarizing radical and it reveals the underlying DNP mechanisms. Here we focus on two chlorinated trityl radicals that feature axially symmetric powder patterns at 95 GHz, the width of which are narrower than those of TEMPOL or TOTAPOL but broader than that of the trityl derivative OX63. The static DNP lineshapes of these commonly used radicals in DNP, have been recently analyzed in terms of a superposition of basic Solid Effect (SE) and Cross Effect (CE)-DNP lineshapes, with their relative contributions as a fit parameter. To substantiate the generality of this approach and further investigate an earlier suggestion that a (35,37)Cl-(13)C polarization transfer pathway, termed "hetero-nuclear assisted DNP", may be in effect in the chlorinated radicals (C. Gabellieri et al., Angew. Chem., Int. Ed., 2010, 49, 3360-3362), we measured the static (13)C-glycerol DNP spectra of solutions of ca. ∼10 mM of the two chlorinated trityl radicals as a function of temperature (10-50 K) and microwave power. Analysis of the DNP lineshapes was first done in terms of the SE/CE superposition model calculated assuming a direct e-(13)C polarization transfer. The CE was found to prevail at the high temperature range (40-50 K), whereas at the low temperature end (10-20 K) the SE dominates, as was observed earlier for (13)C DNP with OX63 and (1)H DNP with TEMPOL and TOTAPOL, thus indicating that this is rather general behavior. Furthermore, it was found that at low temperatures it is possible to suppress the SE, and increase the CE by merely lowering the microwave power. While this analysis gave a good agreement between experimental and calculated lineshapes when the CE dominates, some significant discrepancies were observed at low temperatures, where the SE dominates. We show that by explicitly taking into account the presence of (35/37)Cl nuclei through a e-(35,37)Cl-(13)C polarization pathway in the SE-DNP lineshape calculations, as proposed earlier, we can improve the fit significantly, thus supporting the existence of the "hetero-nuclear assisted DNP" pathway.


Assuntos
Cloro/química , Compostos de Tritil/química , Isótopos de Carbono , Radicais Livres/química , Isótopos , Espectroscopia de Ressonância Magnética , Micro-Ondas
12.
Am J Transplant ; 13(7): 1703-12, 2013 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-23710661

RESUMO

SRTR report cards provide the basis for quality measurement of US transplant centers. There is limited data evaluating the prognostic value of report cards, informing whether they are predictive of prospective patient outcomes. Using national SRTR data, we simulated report cards and calculated standardized mortality ratios (SMR) for kidney transplant centers over five distinct eras. We ranked centers based on SMR and evaluated outcomes for patients transplanted the year following reports. Recipients transplanted at the 50th, 100th and 200th ranked centers had 18% (AHR = 1.18, 1.13-1.22), 38% (AHR = 1.38, 1.28-1.49) and 91% (AHR = 1.91, 1.64-2.21) increased hazard for 1-year mortality relative to recipients at the top-ranked center. Risks were attenuated but remained significant for long-term outcomes. Patients transplanted at centers meeting low-performance criteria in the prior period had 40% (AHR = 1.40, 1.22-1.68) elevated hazard for 1-year mortality in the prospective period. Centers' SMR from the report card was highly predictive (c-statistics > 0.77) for prospective center SMRs and there was significant correlation between centers' SMR from the report card period and the year following (ρ = 0.57, p < 0.001). Although results do not mitigate potential biases of report cards for measuring quality, they do indicate strong prognostic value for future outcomes. Findings also highlight that outcomes are associated with center ranking across a continuum rather than solely at performance margins.


Assuntos
Registros Hospitalares/estatística & dados numéricos , Transplante de Rim/estatística & dados numéricos , Indicadores de Qualidade em Assistência à Saúde , Sistema de Registros , Adulto , Feminino , Seguimentos , Humanos , Transplante de Rim/normas , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Obtenção de Tecidos e Órgãos/estatística & dados numéricos
13.
Am J Transplant ; 13(4): 1001-1011, 2013 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-23406350

RESUMO

As of May 2012, over 92 000 patients were awaiting a solitary kidney transplant in the United States and new waitlist registrations have been rising for over a decade. The decreasing availability of donor organs makes it imperative that organ allocation be as efficient and effective as possible. We performed a retrospective cohort study of adult recipients in the United States (n=109 392) using Scientific Registry of Transplant Recipients data. The primary aim was to evaluate the interaction of donor risk with recipient characteristics on posttransplant outcomes. Donor quality (based on kidney donor risk index [KDRI]) had significant interactions by race, primary diagnosis and age. The hazard of KDRI on overall graft loss in non-African Americans was 2.16 (95%CI 2.08-2.25) versus 1.85 (95%CI 1.75-1.95) in African Americans (p<0.0001), 2.16 (95%CI 2.08-2.24) in nondiabetics versus 1.84 (95%CI 1.74-1.94) in diabetics (p<0.0001), and 2.22 (95%CI 2.13-2.32) in recipients<60 years versus 1.83 (95%CI 1.74-1.92) in recipients≥60 (p<0.0001). The relative hazard for diabetics at KDRI=0.5 was 1.49 but at KDRI=2.0 the hazard was significantly attenuated to 1.17; among African Americans the respective risks were 1.50 and 1.17 and among recipients 60 and over, it was between 1.64 and 1.22. These findings are critical considerations for informed decision-making for transplant candidates.


Assuntos
Transplante de Rim/métodos , Insuficiência Renal/terapia , Doadores de Tecidos , Obtenção de Tecidos e Órgãos/métodos , Adolescente , Adulto , Negro ou Afro-Americano , Idoso , Diabetes Mellitus/metabolismo , Feminino , Sobrevivência de Enxerto , Humanos , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Modelos de Riscos Proporcionais , Sistema de Registros , Estudos Retrospectivos , Fatores de Risco , Resultado do Tratamento , Estados Unidos , Listas de Espera , Adulto Jovem
14.
Am J Transplant ; 13(9): 2374-83, 2013 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-24034708

RESUMO

Numerous factors impact patients' health beyond traditional clinical characteristics. We evaluated the association of risk factors in kidney transplant patients' communities with outcomes prior to transplantation. The primary exposure variable was a community risk score (range 0-40) derived from multiple databases and defined by factors including prevalence of comorbidities, access and quality of healthcare, self-reported physical and mental health and socioeconomic status for each U.S. county. We merged data with the Scientific Registry of Transplant Recipients (SRTR) and utilized risk-adjusted models to evaluate effects of community risk for adult candidates listed 2004-2010 (n = 209 198). Patients in highest risk communities were associated with increased mortality (adjusted hazard ratio [AHR] = 1.22, 1.16-1.28), decreased likelihood of living donor transplantation (adjusted odds ratio [AOR] = 0.90, 0.85-0.94), increased waitlist removal for health deterioration (AHR = 1.36, 1.22-1.51), decreased likelihood of preemptive listing (AOR = 0.85, 0.81-0.88), increased likelihood of inactive listing (AOR = 1.49, 1.43-1.55) and increased likelihood of listing for expanded criteria donor kidneys (AHR = 1.19, 1.15-1.24). Associations persisted with adjustment for rural-urban location; furthermore the independent effects of rural-urban location were largely eliminated with adjustment for community risk. Average community risk varied widely by region and transplant center (median = 21, range 5-37). Community risks are powerful factors associated with processes of care and outcomes for transplant candidates and may be important considerations for developing effective interventions and measuring quality of care of transplant centers.


Assuntos
Serviços de Saúde Comunitária/provisão & distribuição , Transplante de Rim/mortalidade , Adulto , Idoso , Feminino , Acessibilidade aos Serviços de Saúde , Humanos , Falência Renal Crônica/etnologia , Doadores Vivos , Masculino , Pessoa de Meia-Idade , Razão de Chances , Fatores de Risco , População Rural , Doadores de Tecidos , Resultado do Tratamento , População Urbana , Listas de Espera/mortalidade
15.
Am J Transplant ; 13(1): 67-75, 2013 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-23279681

RESUMO

Report cards evaluating transplant center performance have received significant attention in recent years corresponding with the Centers for Medicare and Medicaid Services issue of the 2007 Conditions of Participation. Our primary aim was to evaluate the association of report card evaluations with transplant center volume. We utilized data from the Scientific Registry of Transplant Recipients (SRTR) along with six consecutive program-specific reports from January 2007 to July 2009 for adult kidney transplant centers. Among 203 centers, 46 (23%) were low performing (LP) with statistically significantly lower than expected 1-year graft or patient survival at least once during the study period. Among LP centers, there was a mean decline in transplant volume of 22.4 cases compared to a mean increase of 7.8 transplants among other centers (p = 0.001). Changes in volume between LP and other centers were significant for living, standard and expanded criteria deceased donor (ECD) transplants. LPs had a reduction in use of donors with extended cold ischemia time (p = 0.04) and private pay recipients (p = 0.03). Centers without low performance evaluations were more likely to increase the proportion of overall transplants that were ECDs relative to other centers (p = 0.04). Findings indicate a significant association between reduced kidney transplant volume and low performance report card evaluations.


Assuntos
Transplante de Rim/estatística & dados numéricos , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estados Unidos
16.
Appl Magn Reson ; 44(6): 649-670, 2013 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-23687407

RESUMO

In this work, the experimental conditions and parameters necessary to optimize the long-distance (≥ 60 Å) Double Electron-Electron Resonance (DEER) measurements of biomacromolecules labeled with Gd(III) tags are analyzed. The specific parameters discussed are the temperature, microwave band, the separation between the pumping and observation frequencies, pulse train repetition rate, pulse durations and pulse positioning in the electron paramagnetic resonance spectrum. It was found that: (i) in optimized DEER measurements, the observation pulses have to be applied at the maximum of the EPR spectrum; (ii) the optimal temperature range for Ka-band measurements is 14-17 K, while in W-band the optimal temperatures are between 6-9 K; (iii) W-band is preferable to Ka-band for DEER measurements. Recent achievements and the conditions necessary for short-distance measurements (<15 Å) are also briefly discussed.

17.
Sci Rep ; 13(1): 2163, 2023 02 07.
Artigo em Inglês | MEDLINE | ID: mdl-36750714

RESUMO

Presented here is a magnetic hydrogel particle enabled workflow for capturing and concentrating SARS-CoV-2 from diagnostic remnant swab samples that significantly improves sequencing results using the Oxford Nanopore Technologies MinION sequencing platform. Our approach utilizes a novel affinity-based magnetic hydrogel particle, circumventing low input sample volumes and allowing for both rapid manual and automated high throughput workflows that are compatible with Nanopore sequencing. This approach enhances standard RNA extraction protocols, providing up to 40 × improvements in viral mapped reads, and improves sequencing coverage by 20-80% from lower titer diagnostic remnant samples. Furthermore, we demonstrate that this approach works for contrived influenza virus and respiratory syncytial virus samples, suggesting that it can be used to identify and improve sequencing results of multiple viruses in VTM samples. These methods can be performed manually or on a KingFisher automation platform.


Assuntos
COVID-19 , Sequenciamento por Nanoporos , Humanos , SARS-CoV-2 , Sequenciamento por Nanoporos/métodos , Hidrogéis , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Fenômenos Magnéticos
18.
Am J Transplant ; 11(10): 2242-6, 2011 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-21827624

RESUMO

Treatment options for a suspicious renal mass in a renal allograft include radical nephrectomy or nephron-sparing surgery (NSS). To our knowledge robotic-assisted laparoscopic partial nephrectomy (RPN) as treatment for a renal mass in a transplant kidney has not been previously reported. We report the case of RPN for a 7-cm renal mass in a transplanted kidney. A 35-year-old female with reflux nephropathy received a living-related donor kidney transplant in 1986. At 24 years after transplantation she had a 7-cm Bosniak III cystic mass of the allograft detected on computerized tomography (CT) scan. Preoperative creatinine was 2.2 mg/dL with an estimated glomerular filtration rate (eGFR) of 25 mL/min/1.73 m(2) . RPN was performed with bulldog clamping of the renal vessels, the graft was left in situ and immunosuppression was maintained postoperatively. Tumor diameter was 7.3 cm with a nephrometry score of 10a. Warm ischemia time (WIT) was 26.5 min. Estimated blood loss was 100 mL. There was no change between pre- and postoperative eGFR. There were no operative complications. Histology was papillary renal cell carcinoma type 1, nuclear grade 2. Margins were negative. RPN is a technically feasible treatment option for a suspicious renal mass in renal allografts.


Assuntos
Neoplasias Renais/cirurgia , Transplante de Rim , Laparoscopia/métodos , Nefrectomia/métodos , Robótica , Adulto , Feminino , Humanos , Tomografia Computadorizada por Raios X
19.
Am J Transplant ; 10(6): 1460-7, 2010 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-20553449

RESUMO

Kidneys from nondirected donors (NDDs) have historically been allocated directly to the deceased donor wait list (DDWL). Recently, however, NDDs have participated in kidney exchange (KE) procedures, including KE 'chains', which have received considerable media attention. This increasing application of KE chains with NDD participation has occurred with limited ethical analysis and without ethical guidelines. This article aims to provide a rigorous ethical evaluation of NDDs and chain KEs. NDDs and bridge donors (BDs) (i.e. living donors who link KE procedures within KE chains) raise several ethical concerns including coercion, privacy, confidentiality, exploitation and commercialization. In addition, although NDD participation in KE procedures may increase transplant numbers, it may also reduce NDD kidney allocation to the DDWL, and disadvantage vulnerable populations, particularly O blood group candidates. Open KE chains (also termed 'never-ending' chains) result in a permanent diversion of NDD kidneys from the DDWL. The concept of limited KE chains is discussed as an ethically preferable means for protecting NDDs and BDs from coercion and minimizing 'backing out', whereas 'honor systems' are rejected because they are coercive and override autonomy. Recent occurrences of BDs backing out argue for adoption of ethically based protective measures for NDD participation in KE.


Assuntos
Rim/imunologia , Doadores Vivos , Comunicação , Meios de Comunicação , Confidencialidade , Análise Ética , Humanos , Doadores de Tecidos , Listas de Espera
20.
Transpl Infect Dis ; 12(2): 155-60, 2010 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-19878490

RESUMO

Histoplasmosis is recognized to occur in the Ohio and Mississippi River Valleys of the United States, but less widely appreciated is its worldwide distribution. We report a case of disseminated histoplasmosis with disease involving skin, lungs, and epiglottis in a renal transplant patient 6 months after a trip to Bangladesh, to highlight the potential risk of acquisition of this infection in the Indian subcontinent.


Assuntos
Histoplasma , Histoplasmose/etiologia , Hospedeiro Imunocomprometido , Transplante de Rim , Bangladesh , Dermatomicoses/etiologia , Epiglotite/etiologia , Humanos , Pneumopatias Fúngicas/etiologia , Masculino , Pessoa de Meia-Idade , Ohio , Infecções Oportunistas/etiologia , Complicações Pós-Operatórias/etiologia , Fatores de Risco , Viagem
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA