Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 220
Filtrar
Más filtros

Bases de datos
Tipo del documento
Intervalo de año de publicación
1.
Clin Microbiol Rev ; 37(1): e0011122, 2024 03 14.
Artículo en Inglés | MEDLINE | ID: mdl-38240603

RESUMEN

There is a growing need for solid organ transplantation (SOT) for people living with human immunodeficiency virus (HIV). With the advent of antiretroviral therapy, people living with HIV are experiencing increased life expectancies and are, therefore, developing more comorbidities, including end-stage organ disease. In cases of advanced organ failure, SOT is often the best therapeutic option to improve quality of life and overall survival. As organ shortages persist, transplantation of organs from donors with HIV to recipients with HIV has become a potential therapeutic option. This article first reviews the current state of organ transplantation from donors without HIV to recipients with HIV (HIV D-/R+) by organ and discusses key lessons learned from these transplant trials, including those about drug-drug interactions, rejection, and opportunistic infections. It then explores transplantation from donors with HIV to recipients with HIV (HIV D+/R+), a new frontier. Finally, it investigates challenges of implementation, including public awareness and regulatory requirements, and explores future directions for SOT in people living with HIV.


Asunto(s)
Infecciones por VIH , Trasplante de Órganos , Humanos , VIH , Calidad de Vida , Infecciones por VIH/tratamiento farmacológico , Donantes de Tejidos
2.
Acta Paediatr ; 113(1): 127-134, 2024 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-37641921

RESUMEN

AIM: To evaluate management of children and young people presenting to the Emergency Department (ED) with magnet ingestion before and after new guidance. METHODS: In May 2021, a National Patient Safety Agency and Royal College of Emergency Medicine (RCEM) Best Practice Guideline about management of ingested magnets was published. This was implemented in our department. Children and young people presenting after magnet ingestion were identified from SNOMED (coded routinely collected data) and X-ray requests between January 2016 and March 2022. Management was compared to national guidance. RESULTS: There were 138 patient episodes of magnet ingestion, with a rising incidence over the 5-year period. Following introduction of the guideline, there was a higher incidence of admission (36% vs. 20%) and operative intervention (15.7% vs. 8%). Use of follow-up X-ray increased from 56% to 90%. There was substantial variation in the management prior to guidance which reduced after introduction of the RCEM guidance. CONCLUSION: Management of magnet ingestion has become more standardised since introduction of the National RCEM Best Practice Guideline, but there is still room for improvement.


Asunto(s)
Cuerpos Extraños , Imanes , Niño , Humanos , Adolescente , Cuerpos Extraños/diagnóstico por imagen , Cuerpos Extraños/terapia , Cuerpos Extraños/epidemiología , Radiografía , Servicio de Urgencia en Hospital , Incidencia , Ingestión de Alimentos
3.
J Intern Med ; 289(5): 709-725, 2021 05.
Artículo en Inglés | MEDLINE | ID: mdl-33107650

RESUMEN

PURPOSE: Pseudoxanthoma elasticum (PXE) is a recessive disorder involving skin, eyes and arteries, mainly caused by ABCC6 pathogenic variants. However, almost one fifth of patients remain genetically unsolved despite extensive genetic screening of ABCC6, as illustrated in a large French PXE series of 220 cases. We searched for new PXE gene(s) to solve the ABCC6-negative patients. METHODS: First, family-based exome sequencing was performed, in one ABCC6-negative PXE patient with additional neurological features, and her relatives. CYP2U1, involved in hereditary spastic paraplegia type 56 (SPG56), was selected based on this complex phenotype, and the presence of two candidate variants. Second, CYP2U1 sequencing was performed in a retrospective series of 46 additional ABCC6-negative PXE probands. Third, six additional SPG56 patients were evaluated for PXE skin and eye phenotype. Additionally, plasma pyrophosphate dosage and functional analyses were performed in some of these patients. RESULTS: 6.4% of ABCC6-negative PXE patients (n = 3) harboured biallelic pathogenic variants in CYP2U1. PXE skin lesions with histological confirmation, eye lesions including maculopathy or angioid streaks, and various neurological symptoms were present. CYP2U1 missense variants were confirmed to impair protein function. Plasma pyrophosphate levels were normal. Two SPG56 patients (33%) presented some phenotypic overlap with PXE. CONCLUSION: CYP2U1 pathogenic variants are found in unsolved PXE patients with neurological findings, including spastic paraplegia, expanding the SPG56 phenotype and highlighting its overlap with PXE. The pathophysiology of ABCC6 and CYP2U1 should be explored to explain their respective role and potential interaction in ectopic mineralization.


Asunto(s)
Familia 2 del Citocromo P450/genética , Proteínas Asociadas a Resistencia a Múltiples Medicamentos/genética , Seudoxantoma Elástico/genética , Paraplejía Espástica Hereditaria/genética , Calcinosis , Sistema Enzimático del Citocromo P-450/metabolismo , Ojo/patología , Células HEK293 , Humanos , Mutación Missense , Fenotipo , Seudoxantoma Elástico/metabolismo , Seudoxantoma Elástico/patología , Estudios Retrospectivos , Piel/patología , Paraplejía Espástica Hereditaria/metabolismo , Paraplejía Espástica Hereditaria/patología
4.
Am J Transplant ; 18(10): 2473-2482, 2018 10.
Artículo en Inglés | MEDLINE | ID: mdl-29701909

RESUMEN

Direct-acting antiviral medications (DAAs) have revolutionized care for hepatitis C positive (HCV+) liver (LT) and kidney (KT) transplant recipients. Scientific Registry of Transplant Recipients registry data were integrated with national pharmaceutical claims (2007-2016) to identify HCV treatments before January 2014 (pre-DAA) and after (post-DAA), stratified by donor (D) and recipient (R) serostatus and payer. Pre-DAA, 18% of HCV+ LT recipients were treated within 3 years and without differences by donor serostatus or payer. Post-DAA, only 6% of D-/R+ recipients, 19.8% of D+/R+ recipients with public insurance, and 11.3% with private insurance were treated within 3 years (P < .0001). LT recipients treated for HCV pre-DAA experienced higher rates of graft loss (adjusted hazard ratio [aHR] 1.34 1.852.10 , P < .0001) and death (aHR 1.47 1.681.91 , P < .0001). Post-DAA, HCV treatment was not associated with death (aHR 0.34 0.671.32 , P = .25) or graft failure (aHR 0.32 0.641.26 , P = .20) in D+R+ LT recipients. Treatment increased in D+R+ KT recipients (5.5% pre-DAA vs 12.9% post-DAA), but did not differ by payer status. DAAs reduced the risk of death after D+/R+ KT by 57% (0.19 0.430.95 , P = .04) and graft loss by 46% (0.27 0.541.07 , P = .08). HCV treatment with DAAs appears to improve HCV+ LT and KT outcomes; however, access to these medications appears limited in both LT and KT recipients.


Asunto(s)
Antivirales/uso terapéutico , Supervivencia de Injerto , Hepacivirus/efectos de los fármacos , Hepatitis C/tratamiento farmacológico , Trasplante de Riñón/economía , Trasplante de Hígado/economía , Listas de Espera/mortalidad , Adolescente , Adulto , Anciano , Femenino , Estudios de Seguimiento , Hepatitis C/virología , Humanos , Trasplante de Riñón/mortalidad , Trasplante de Hígado/mortalidad , Masculino , Persona de Mediana Edad , Pronóstico , Sistema de Registros , Estudios Retrospectivos , Factores de Riesgo , Tasa de Supervivencia , Donantes de Tejidos/provisión & distribución , Receptores de Trasplantes , Adulto Joven
5.
Nanotechnology ; 29(49): 495401, 2018 Dec 07.
Artículo en Inglés | MEDLINE | ID: mdl-30207539

RESUMEN

With a central curved chassis, a four-wheeled molecule-vehicle was deposited on a Au(111) surface and imaged at low temperature using a scanning tunneling microscope. The curved conformation of the chassis and the consequent moderate interactions of the four wheels with the surface were observed. The dI/dV constant current maps of the tunneling electronic resonances close to the Au(111) Fermi level were recorded to identify the potential energy entry port on the molecular skeleton to trigger and control the driving of the molecule. A lateral pushing mode of molecular manipulation and the consequent recording of the manipulation signals confirm how the wheels can step-by-step rotate while passing over the Au(111) surface native herringbone reconstructions. Switching a phenyl holding a wheel to the chassis was not observed for triggering a lateral molecular motion inelastically and without any mechanic push by the tip apex. This points out the necessity to encode the sequence of the required wheels action on the profile of the potential energy surface of the excited states to be able to drive a molecule-vehicle.

6.
Am J Transplant ; 17(2): 519-527, 2017 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-27456927

RESUMEN

The impact of interferon (IFN)-free direct-acting antiviral (DAA) hepatitis C virus (HCV) treatments on utilization and outcomes associated with HCV-positive deceased donor liver transplantation (DDLT) is largely unknown. Using the Scientific Registry of Transplant Recipients, we identified 25 566 HCV-positive DDLT recipients from 2005 to 2015 and compared practices according to the introduction of DAA therapies using modified Poisson regression. The proportion of HCV-positive recipients who received HCV-positive livers increased from 6.9% in 2010 to 16.9% in 2015. HCV-positive recipients were 61% more likely to receive an HCV-positive liver after 2010 (early DAA/IFN era) (aRR:1.45 1.611.79 , p < 0.001) and almost three times more likely to receive one after 2013 (IFN-free DAA era) (aRR:2.58 2.853.16 , p < 0.001). Compared to HCV-negative livers, HCV-positive livers were 3 times more likely to be discarded from 2005 to 2010 (aRR:2.69 2.993.34 , p < 0.001), 2.2 times more likely after 2010 (aRR:1.80 2.162.58 , p < 0.001) and 1.7 times more likely after 2013 (aRR:1.37 1.682.04 , p < 0.001). Donor HCV status was not associated with increased risk of all-cause graft loss (p = 0.1), and this did not change over time (p = 0.8). Use of HCV-positive livers has increased dramatically, coinciding with the advent of DAAs. However, the discard rate remains nearly double that of HCV-negative livers. Further optimization of HCV-positive liver utilization is necessary to improve access for all candidates.


Asunto(s)
Hepacivirus/aislamiento & purificación , Hepatitis C/cirugía , Trasplante de Hígado , Donantes de Tejidos , Obtención de Tejidos y Órganos/estadística & datos numéricos , Trasplantes/virología , Listas de Espera , Adolescente , Adulto , Anciano , Antivirales/uso terapéutico , Femenino , Estudios de Seguimiento , Supervivencia de Injerto , Hepatitis C/tratamiento farmacológico , Hepatitis C/virología , Humanos , Masculino , Persona de Mediana Edad , Receptores de Trasplantes , Resultado del Tratamiento , Adulto Joven
7.
Am J Transplant ; 17(7): 1823-1832, 2017 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-28497525

RESUMEN

New federal regulations allow HIV-positive individuals to be live kidney donors; however, potential candidacy for donation is poorly understood given the increased risk of end-stage renal disease (ESRD) associated with HIV infection. To better understand this risk, we compared the incidence of ESRD among 41 968 HIV-positive participants of North America AIDS Cohort Collaboration on Research and Design followed for a median of 5 years with the incidence of ESRD among comparable HIV-negative participants of National Health and Nutrition Examination III followed for a median of 14 years. We used risk associations from multivariable Cox proportional hazards regression to derive cumulative incidence estimates for selected HIV-positive scenarios (no history of diabetes, hypertension, AIDS, or hepatitis C virus coinfection) and compared these estimates with those from similarly selected HIV-negative scenarios. For 40-year-old HIV-positive individuals with health characteristics that were similar to those of age-matched kidney donors, viral load <400 copies/mL, and CD4+ count ≥500 cells/µL, the 9-year cumulative incidence of ESRD was higher than that of their HIV-negative peers, yet still low: 2.5 versus 1.1 per 10 000 among white women, 3.0 versus 1.3 per 10 000 among white men, 13.2 versus 3.6 per 10 000 among black women, and 15.8 versus 4.4 per 10 000 among black men. HIV-positive individuals with no comorbidities and well-controlled disease may be considered low-risk kidney donor candidates.


Asunto(s)
Rechazo de Injerto/epidemiología , Infecciones por VIH/complicaciones , Fallo Renal Crónico/epidemiología , Trasplante de Riñón/efectos adversos , Donadores Vivos , Adulto , Estudios de Casos y Controles , Femenino , Estudios de Seguimiento , Tasa de Filtración Glomerular , Rechazo de Injerto/etiología , Supervivencia de Injerto , Infecciones por VIH/virología , Seropositividad para VIH , VIH-1/fisiología , Humanos , Incidencia , Fallo Renal Crónico/etiología , Pruebas de Función Renal , Masculino , Persona de Mediana Edad , Nefrectomía , América del Norte/epidemiología , Pronóstico , Factores de Riesgo , Carga Viral
8.
Am J Transplant ; 16(8): 2368-76, 2016 08.
Artículo en Inglés | MEDLINE | ID: mdl-27111897

RESUMEN

There is an increased risk of acute rejection (AR) in human immunodeficiency virus-positive (HIV+) kidney transplant (KT) recipients. Induction immunosuppression is standard of care for those at high risk of AR; however, use in HIV+ patients is controversial, given fears of increased infection rates. We sought to compare clinical outcomes between HIV+ KT recipients who were treated with (i) anti-thymocyte globulin (ATG), (ii) IL-2 receptor blocker, and (iii) no induction. We studied 830 HIV+ KT recipients between 2000 and 2014, as captured in the Scientific Registry of Transplant Recipients, and compared rates of delayed graft function (DGF), AR, graft loss and death. Infections and hospitalizations were ascertained by International Classification of Diseases, Ninth Revision codes in a subset of 308 patients with Medicare. Compared with no induction, neither induction agent was associated with an increased risk of infection (weighted hazard ratio [wHR] 0.80, 95% confidence interval [CI] 0.55-1.18). HIV+ recipients who received induction spent fewer days in the hospital (weighted relative risk [wRR] 0.70, 95% CI 0.52-0.95), had lower rates of DGF (wRR 0.66, 95% CI 0.51-0.84), less graft loss (wHR 0.47, 95% CI 0.24-0.89) and a trend toward lower mortality (wHR 0.60, 95% CI 0.24-1.28). Those who received induction with ATG had lower rates of AR (wRR 0.59, 95% CI 0.35-0.99). Induction in HIV+ KT recipients was not associated with increased infections; in fact, those receiving ATG, the most potent agent, had the lowest rates. In light of the high risk of AR in this population, induction therapy should be strongly considered.


Asunto(s)
Rechazo de Injerto/tratamiento farmacológico , Infecciones por VIH/complicaciones , Inmunosupresores/uso terapéutico , Fallo Renal Crónico/cirugía , Trasplante de Riñón/efectos adversos , Adulto , Suero Antilinfocítico/farmacología , Femenino , Estudios de Seguimiento , Tasa de Filtración Glomerular , Rechazo de Injerto/etiología , Supervivencia de Injerto , Infecciones por VIH/inmunología , Infecciones por VIH/virología , VIH-1/aislamiento & purificación , Humanos , Terapia de Inmunosupresión , Quimioterapia de Inducción , Fallo Renal Crónico/complicaciones , Pruebas de Función Renal , Masculino , Persona de Mediana Edad , Complicaciones Posoperatorias , Pronóstico , Factores de Riesgo
9.
Clin Genet ; 89(1): 5-9, 2016 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-26333625

RESUMEN

Fabry disease is an X-linked metabolic storage disorder due to the deficiency of lysosomal alpha-galactosidase A which causes accumulation of glycosphingolipids, primarily globotriaosylceramide, throughout the body. Gastrointestinal signs and symptoms-abdominal pain, nausea, diarrhea and diverticular disease--are some of the most frequently reported complaints in patients with Fabry disease but are often neglected. Gastrointestinal symptoms are due to intestinal dysmotility as well as impaired autonomic function, vasculopathy and myopathy. Since 2001, enzyme replacement therapy has been a mainstay in treatment of gastrointestinal symptoms of Fabry disease (FD), resulting in reduced gastrointestinal symptoms. Here, we report on four patients with Fabry disease (FD) who manifested early gastrointestinal involvement.


Asunto(s)
Enfermedad de Fabry/diagnóstico , Enfermedad de Fabry/metabolismo , Enfermedades Gastrointestinales/diagnóstico , Enfermedades Gastrointestinales/metabolismo , Tracto Gastrointestinal/metabolismo , Adolescente , Adulto , Animales , Biomarcadores , Encéfalo/metabolismo , Encéfalo/patología , Niño , Comorbilidad , Diagnóstico Diferencial , Enfermedad de Fabry/etiología , Femenino , Enfermedades Gastrointestinales/etiología , Humanos , Imagen por Resonancia Magnética , Masculino , Persona de Mediana Edad , Tomografía Computarizada por Rayos X , Adulto Joven
10.
Transpl Infect Dis ; 18(1): 146-9, 2016 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-26565742

RESUMEN

BACKGROUND: Ventricular assist devices (VADs) have been associated with immune activation and sensitization. We observed several cases of false-positive (FP) hepatitis C virus (HCV) antibody (Ab) tests in patients being evaluated for orthotopic heart transplant (OHT), prompting us to investigate this further. METHODS: We reviewed all VAD and OHT cases at Johns Hopkins from 2005 to 2012. FP HCV serology was defined as an equivocal or low-positive HCV Ab, plus either (i) a negative recombinant immunoblot (RIBA) and/or HCV nucleic acid test (NAT), or (ii) an indeterminate RIBA and negative NAT. RESULTS: In 53 patients with available HCV testing, nearly 40% of patients (21/53: 39.6%) developed FP HCV Ab tests after VAD placement: 4 patients had negative NAT, 12 had negative RIBA, and 5 had an indeterminate RIBA and negative NAT. All patients with indeterminate RIBA tests had isolated reactivity to the same HCV protein, c100p/5-1-1p (NS4b protein). In 3 of 4 VAD patients who had OHT and repeat HCV Ab testing after VAD removal, repeat HCV Ab was negative (699-947 days after OHT); in 1 case, FP HCV serology persisted (5 days after OHT). Thirteen patients had OHT alone and none developed a FP HCV Ab. CONCLUSIONS: FP HCV Ab results following VAD placement are very common. Reversal of FP serology in several patients after VAD removal is suggestive of a possible association with the VAD hardware. Clinicians should be aware of this phenomenon, as it could lead to delays in determining eligibility for OHT and increased costs.


Asunto(s)
Hepacivirus/inmunología , Anticuerpos contra la Hepatitis C/sangre , Hepatitis C/diagnóstico , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Reacciones Falso Positivas , Femenino , Corazón Auxiliar/virología , Hepacivirus/genética , Hepacivirus/aislamiento & purificación , Hepatitis C/virología , Humanos , Masculino , Persona de Mediana Edad , ARN Viral/sangre , Estudios Retrospectivos , Pruebas Serológicas , Adulto Joven
11.
Am J Transplant ; 15(8): 2023-30, 2015 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-26080612

RESUMEN

Life expectancy among HIV-infected (HIV+) individuals has improved dramatically with effective antiretroviral therapy. Consequently, chronic diseases such as end-stage liver and kidney disease are growing causes of morbidity and mortality. HIV+ individuals can have excellent outcomes after solid organ transplantation, and the need for transplantation in this population is increasing. However, there is a significant organ shortage, and HIV+ individuals experience higher mortality rates on transplant waitlists. In South Africa, the use of organs from HIV+ deceased donors (HIVDD) has been successful, but until recently federal law prohibited this practice in the United States. With the recognition that organs from HIVDD could fill a critical need, the HIV Organ Policy Equity (HOPE) Act was passed in November 2013, reversing the federal ban on the use of HIV+ donors for HIV+ recipients. In translating this policy into practice, the biologic risks of using HIV+ donors need to be carefully considered. In this mini-review, we explore relevant aspects of HIV virology, antiretroviral treatment, drug resistance, opportunistic infections and HIV-related organ dysfunction that are critical to a transplant team considering HIV-to-HIV transplantation.


Asunto(s)
Infecciones por VIH/cirugía , Trasplante de Riñón , Trasplante de Hígado , Pautas de la Práctica en Medicina , Infecciones Oportunistas Relacionadas con el SIDA/epidemiología , Fármacos Anti-VIH/uso terapéutico , Reservorios de Enfermedades , Interacciones Farmacológicas , VIH/fisiología , Infecciones por VIH/tratamiento farmacológico , Infecciones por VIH/transmisión , Humanos , Estados Unidos , Tropismo Viral
12.
Am J Transplant ; 15(8): 2096-104, 2015 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-25773499

RESUMEN

Excellent outcomes among HIV+ kidney transplant (KT) recipients have been reported by the NIH consortium, but it is unclear if experience with HIV+ KT is required to achieve these outcomes. We studied associations between experience measures and outcomes in 499 HIV+ recipients (SRTR data 2004-2011). Experience measures examined included: (1) center-level participation in the NIH consortium; (2) KT experiential learning curve; and (3) transplant era (2004-2007 vs. 2008-2011). There was no difference in outcomes among centers early in their experience (first 5 HIV+ KT) compared to centers having performed >6 HIV+ KT (GS adjusted hazard ratio [aHR]: 1.05, 95% CI: 0.68-1.61, p = 0.82; PS aHR: 0.93; 95% CI: 0.56-1.53, p = 0.76), and participation in the NIH-study was not associated with any better outcomes (GS aHR: 1.08, 95% CI: 0.71-1.65, p = 0.71; PS aHR: 1.13; 95% CI: 0.68-1.89, p = 0.63). Transplant era was strongly associated with outcomes; HIV+ KTs performed in 2008-2011 had 38% lower risk of graft loss (aHR: 0.62; 95% CI: 0.42-0.92, p = 0.02) and 41% lower risk of death (aHR: 0.59; 95% CI: 0.39-0.90, p = 0.01) than that in 2004-2007. Outcomes after HIV+ KT have improved over time, but center-level experience or consortium participation is not necessary to achieve excellent outcomes, supporting continued expansion of HIV+ KT in the US.


Asunto(s)
Infecciones por VIH/cirugía , Trasplante de Riñón , Adolescente , Adulto , Anciano , Humanos , Persona de Mediana Edad , Estados Unidos , Adulto Joven
13.
Minerva Gastroenterol Dietol ; 61(1): 39-49, 2015 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-25390288

RESUMEN

Hepatitis C virus (HCV) infection is a rising global public health burden with an estimated 130-150 million infected people worldwide and 350,000 to 500,000 HCV-related deaths each year. Chronic kidney disease (CKD) is also a highly prevalent public health issue as the escalating numbers of patients worldwide are developing type 2 diabetes mellitus and hypertension due to high fat diets and a growing obesity epidemic. The high incidence and prevalence of HCV infection leads to substantial morbidity and mortality among renal dialysis patients. Recommendations are to screen for HCV infection among all patients with renal failure especially prior to initiation of hemodialysis and renal transplant evaluation. HCV-antibody enzyme immunoassay (EIA) followed by confirmation with HCV RNA nucleic acid test (NAT) is recommended for low prevalence regions, but in dialysis centers with a high prevalence of HCV, initial testing with NAT is recommended due to higher false positive EIA rates. Liver biopsy is used to assess of liver disease severity. Transjugular liver biopsy, as an effective and safe technique in patients with ESRD can be considered instead of percutaneous approach. Non-invasive approaches to staging fibrosis, including liver stiffness measurement by transient elastography and panels of serum fibrosis biomarkers, are also widely used. Although difficult to manage, combined pegylated- interferon (PEG IFN) and ribavirin therapy was the only treatment modality available for HCV-positive patients until the recently introduced new direct-acting antiviral agents. However, except boceprevir, there are no currently available data to suggest that these new anti-viral drugs are safe and effective among end-stage renal failure patients. IFN-containing regimens were also associated with high rates of renal graft loss in post-renal transplant patients. Therefore, management of HCV infection in renal failure patients is unique and should be tailored individually with calculated risk/benefit ratio. New studies are immediately warranted to determine the safety profile and efficacy of newer anti-HCV drugs not only in patients with end-stage renal failure prior to kidney transplantation but also among kidney transplant recipients.


Asunto(s)
Antivirales/uso terapéutico , Hepatitis C/tratamiento farmacológico , Fallo Renal Crónico/complicaciones , Prolina/análogos & derivados , Antivirales/efectos adversos , Salud Global , Guías como Asunto , Hepatitis C/diagnóstico , Hepatitis C/epidemiología , Humanos , Incidencia , Italia/epidemiología , Trasplante de Riñón , Prevalencia , Prolina/efectos adversos , Prolina/uso terapéutico , Resultado del Tratamiento
14.
Nano Lett ; 14(6): 3515-20, 2014 Jun 11.
Artículo en Inglés | MEDLINE | ID: mdl-24837282

RESUMEN

We report the fabrication of a photonic platform consisting of single wire light-emitting diodes (LED) and photodetectors optically coupled by waveguides. MOVPE-grown (metal-organic vapor-phase epitaxy) InGaN/GaN p-n junction core-shell nanowires have been used for device fabrication. To achieve a good spectral matching between the emission wavelength and the detection range, different active regions containing either five narrow InGaN/GaN quantum wells or one wide InGaN segment were employed for the LED and the detector, respectively. The communication wavelength is ∼400 nm. The devices are realized by means of electron beam lithography on Si/SiO2 templates and connected by ∼100 µm long nonrectilinear SiN waveguides. The photodetector current trace shows signal variation correlated with the LED on/off switching with a fast transition time below 0.5 s.

15.
Nanotechnology ; 25(25): 255201, 2014 Jun 27.
Artículo en Inglés | MEDLINE | ID: mdl-24897006

RESUMEN

We report a systematic experimental and theoretical investigation of core-shell InGaN/GaN single wire light-emitting diodes (LEDs) using electron beam induced current (EBIC) microscopy. The wires were grown by catalyst-free MOVPE and processed into single wire LEDs using electron beam lithography on dispersed wires. The influence of the acceleration voltage and of the applied bias on the EBIC maps was investigated. We show that the EBIC maps provide information both on the minority carrier effects (i.e. on the local p-n junction collection efficiency) and on the majority carrier effects (i.e. the transport efficiency from the excited region toward the contacts). Because of a finite core and shell resistance a non-negligible current redistribution into the p-n junction takes place during the majority carrier transport. A theoretical model for transport in a core-shell wire is developed, allowing to explain the dependence of the EBIC profiles on the experimental parameters (the electron beam acceleration voltage and the bias applied on the device) and on the structural parameters of the wire (core and shell resistance, shunt resistance, etc). Comparison between simulated and experimental profiles provides valuable information concerning the structure inhomogeneities and gives insight into the wire electrical parameters.

16.
J Orthop Traumatol ; 15(1): 55-8, 2014 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-23797389

RESUMEN

BACKGROUND: The conventional approach for MRI procedures in very young children is to use general anesthesia which comes with inherent risks. Non-pharmacological strategies to reduce anxiety in children have also been described, but they all require patient cooperation. The purpose of the study was to evaluate the ability to complete diagnosis using temporary spica cast immobilization (TSCI) in children less than 3 years old undergoing MRI procedures for lower limb disorders. MATERIALS AND METHODS: A retrospective review identified 14 children under 3 years old that had required an MRI for a lower limb disorder, using TSCI. The MRI procedure was performed for evaluation of hip dysplasia, bone infections, limping, evaluation of soft tissue tumor and femoral head osteonecrosis. A spica cast was fitted by the pediatric orthopedic team. The MRI procedure was subsequently performed. RESULTS: Diagnosis was achieved in all cases. The radiologist identified movement artifacts (14 %) that did not impair the image quality enough to prevent interpretation. CONCLUSION: TSCI is a safe, effective and costless procedure avoiding general anesthesia for young patients under 3 years old who require MRI for pelvis or lower limb disorders. LEVEL OF EVIDENCE: IV.


Asunto(s)
Moldes Quirúrgicos , Inmovilización/métodos , Imagen por Resonancia Magnética/métodos , Osteomielitis/patología , Factores de Edad , Anestesia General , Preescolar , Femenino , Luxación Congénita de la Cadera/patología , Humanos , Lactante , Pierna , Masculino , Osteítis/patología , Osteonecrosis/patología , Estudios Retrospectivos , Neoplasias de los Tejidos Blandos/patología
17.
Rev Sci Instrum ; 95(1)2024 Jan 01.
Artículo en Inglés | MEDLINE | ID: mdl-38236087

RESUMEN

We present the development of an experimental platform that can collect four frames of x-ray diffraction data along a single line of sight during laser-driven, dynamic-compression experiments at the National Ignition Facility. The platform is comprised of a diagnostic imager built around ultrafast sensors with a 2-ns integration time, a custom target assembly that serves also to shield the imager, and a 10-ns duration, quasi-monochromatic x-ray source produced by laser-generated plasma. We demonstrate the performance with diffraction data for Pb ramp compressed to 150 GPa and illuminated by a Ge x-ray source that produces ∼7 × 1011, 10.25-keV photons/ns at the 400 µm diameter sample.

18.
Mol Psychiatry ; 17(1): 71-84, 2012 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-21606927

RESUMEN

Genetic mutations of SHANK3 have been reported in patients with intellectual disability, autism spectrum disorder (ASD) and schizophrenia. At the synapse, Shank3/ProSAP2 is a scaffolding protein that connects glutamate receptors to the actin cytoskeleton via a chain of intermediary elements. Although genetic studies have repeatedly confirmed the association of SHANK3 mutations with susceptibility to psychiatric disorders, very little is known about the neuronal consequences of these mutations. Here, we report the functional effects of two de novo mutations (STOP and Q321R) and two inherited variations (R12C and R300C) identified in patients with ASD. We show that Shank3 is located at the tip of actin filaments and enhances its polymerization. Shank3 also participates in growth cone motility in developing neurons. The truncating mutation (STOP) strongly affects the development and morphology of dendritic spines, reduces synaptic transmission in mature neurons and also inhibits the effect of Shank3 on growth cone motility. The de novo mutation in the ankyrin domain (Q321R) modifies the roles of Shank3 in spine induction and morphology, and actin accumulation in spines and affects growth cone motility. Finally, the two inherited mutations (R12C and R300C) have intermediate effects on spine density and synaptic transmission. Therefore, although inherited by healthy parents, the functional effects of these mutations strongly suggest that they could represent risk factors for ASD. Altogether, these data provide new insights into the synaptic alterations caused by SHANK3 mutations in humans and provide a robust cellular readout for the development of knowledge-based therapies.


Asunto(s)
Actinas/metabolismo , Proteínas Portadoras/genética , Dendritas/ultraestructura , Espinas Dendríticas/genética , Mutación/genética , Neuronas/citología , Animales , Trastorno Autístico/genética , Línea Celular Transformada/citología , Células Cultivadas , Chlorocebus aethiops , Dendritas/genética , Espinas Dendríticas/fisiología , Proteínas Fluorescentes Verdes/genética , Proteínas Fluorescentes Verdes/metabolismo , Hipocampo/citología , Humanos , Microscopía Confocal , Proteínas del Tejido Nervioso , Transfección , Tubulina (Proteína)/metabolismo
19.
Transpl Infect Dis ; 15(3): 233-42, 2013 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-23432974

RESUMEN

BACKGROUND: The epidemiology of invasive mold infections (IMI) in transplant recipients differs based on geography, hosts, preventative strategies, and methods of diagnosis. METHODS: We conducted a retrospective observational study to evaluate the epidemiology of proven and probable IMI, using prior definitions, among all adult hematopoietic stem cell transplant (HSCT) and solid organ transplant (SOT) recipients in the era of "classic" culture-based diagnostics (2000-2009). Epidemiology was evaluated before and after an initiative was begun to increase bronchoscopy in HSCT recipients after 2005. RESULTS: In total, 106 patients with one IMI were identified. Invasive aspergillosis (IA) was the most common IMI (69; 65.1%), followed by mucormycosis (9; 8.5%). The overall rate of IMI (and IA) was 3.5% (2.5%) in allogeneic HSCT recipients. The overall incidence for IMI among lung, kidney, liver, and heart transplant recipients was 49, 2, 11, and 10 per 1000 person-years, respectively. The observed rate of IMI among human leukocyte antigen-matched unrelated and haploidentical HSCT recipients increased from 0.6% annually to 3.0% after bronchoscopy initiation (P < 0.05). The 12-week mortality among allogeneic HSCT, liver, kidney, heart, and lung recipients with IMI was 52.4%, 47.1%, 27.8%, 16.7%, and 9.5%, respectively. Among allogeneic HSCT (odds ratio [OR]: 0.07, P = 0.007) and SOT (OR: 0.22, P = 0.05) recipients with IA, normal platelet count was associated with improved survival. Male gender (OR: 14.4, P = 0.007) and elevated bilirubin (OR: 5.7, P = 0.04) were significant predictors of mortality for allogeneic HSCT and SOT recipients with IA, respectively. CONCLUSIONS: During the era of culture-based diagnostics, observed rates of IMI were low among all transplants except lung transplant recipients, with relatively higher mortality rates. Diagnostic aggressiveness and host variables impact the reported incidence and outcome of IMI and likely account for institutional variability in multicenter studies. Definitions to standardize diagnoses among SOT recipients are needed.


Asunto(s)
Aspergilosis/epidemiología , Aspergilosis/mortalidad , Trasplante de Células Madre Hematopoyéticas/efectos adversos , Mucormicosis/epidemiología , Mucormicosis/mortalidad , Trasplante de Órganos/efectos adversos , Adulto , Anciano , Aspergilosis/tratamiento farmacológico , Femenino , Humanos , Incidencia , Masculino , Persona de Mediana Edad , Mucormicosis/tratamiento farmacológico , Estudios Retrospectivos , Adulto Joven
20.
Rev Sci Instrum ; 94(12)2023 Dec 01.
Artículo en Inglés | MEDLINE | ID: mdl-38088778

RESUMEN

Nanosecond-gated hybrid complementary metal-oxide semiconductor imaging sensors are a powerful tool for temporally gated and spatially resolved measurements in high energy density science, including inertial confinement fusion, and in laser diagnostics. However, a significant oscillating background excited by photocurrent has been observed in image sequences during testing and in experiments at the National Ignition Facility (NIF). Characterization measurements and simulation results are used to explain the oscillations as the convolution of the pixel-level sensor response with a sensor-wide RLC circuit ringing. Data correction techniques are discussed for NIF diagnostics, and for diagnostics where these techniques cannot be used, a proof-of-principle image correction algorithm is presented.

SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA