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1.
PLoS Med ; 18(9): e1003739, 2021 09.
Artículo en Inglés | MEDLINE | ID: mdl-34491987

RESUMEN

BACKGROUND: Among people living with HIV (PLHIV), more flexible and sensitive tuberculosis (TB) screening tools capable of detecting both symptomatic and subclinical active TB are needed to (1) reduce morbidity and mortality from undiagnosed TB; (2) facilitate scale-up of tuberculosis preventive therapy (TPT) while reducing inappropriate prescription of TPT to PLHIV with subclinical active TB; and (3) allow for differentiated HIV-TB care. METHODS AND FINDINGS: We used Botswana XPRES trial data for adult HIV clinic enrollees collected during 2012 to 2015 to develop a parsimonious multivariable prognostic model for active prevalent TB using both logistic regression and random forest machine learning approaches. A clinical score was derived by rescaling final model coefficients. The clinical score was developed using southern Botswana XPRES data and its accuracy validated internally, using northern Botswana data, and externally using 3 diverse cohorts of antiretroviral therapy (ART)-naive and ART-experienced PLHIV enrolled in XPHACTOR, TB Fast Track (TBFT), and Gugulethu studies from South Africa (SA). Predictive accuracy of the clinical score was compared with the World Health Organization (WHO) 4-symptom TB screen. Among 5,418 XPRES enrollees, 2,771 were included in the derivation dataset; 67% were female, median age was 34 years, median CD4 was 240 cells/µL, 189 (7%) had undiagnosed prevalent TB, and characteristics were similar between internal derivation and validation datasets. Among XPHACTOR, TBFT, and Gugulethu cohorts, median CD4 was 400, 73, and 167 cells/µL, and prevalence of TB was 5%, 10%, and 18%, respectively. Factors predictive of TB in the derivation dataset and selected for the clinical score included male sex (1 point), ≥1 WHO TB symptom (7 points), smoking history (1 point), temperature >37.5°C (6 points), body mass index (BMI) <18.5kg/m2 (2 points), and severe anemia (hemoglobin <8g/dL) (3 points). Sensitivity using WHO 4-symptom TB screen was 73%, 80%, 94%, and 94% in XPRES, XPHACTOR, TBFT, and Gugulethu cohorts, respectively, but increased to 88%, 87%, 97%, and 97%, when a clinical score of ≥2 was used. Negative predictive value (NPV) also increased 1%, 0.3%, 1.6%, and 1.7% in XPRES, XPHACTOR, TBFT, and Gugulethu cohorts, respectively, when the clinical score of ≥2 replaced WHO 4-symptom TB screen. Categorizing risk scores into low (<2), moderate (2 to 10), and high-risk categories (>10) yielded TB prevalence of 1%, 1%, 2%, and 6% in the lowest risk group and 33%, 22%, 26%, and 32% in the highest risk group for XPRES, XPHACTOR, TBFT, and Gugulethu cohorts, respectively. At clinical score ≥2, the number needed to screen (NNS) ranged from 5.0 in Gugulethu to 11.0 in XPHACTOR. Limitations include that the risk score has not been validated in resource-rich settings and needs further evaluation and validation in contemporary cohorts in Africa and other resource-constrained settings. CONCLUSIONS: The simple and feasible clinical score allowed for prioritization of sensitivity and NPV, which could facilitate reductions in mortality from undiagnosed TB and safer administration of TPT during proposed global scale-up efforts. Differentiation of risk by clinical score cutoff allows flexibility in designing differentiated HIV-TB care to maximize impact of available resources.


Asunto(s)
Antirretrovirales/uso terapéutico , Antituberculosos/uso terapéutico , Coinfección , Infecciones por VIH/tratamiento farmacológico , Sobrevivientes de VIH a Largo Plazo , Tamizaje Masivo , Servicios Preventivos de Salud , Tuberculosis/prevención & control , Adulto , Antirretrovirales/efectos adversos , Antituberculosos/efectos adversos , Botswana/epidemiología , Ensayos Clínicos como Asunto , Diagnóstico Precoz , Femenino , Infecciones por VIH/diagnóstico , Infecciones por VIH/epidemiología , Infecciones por VIH/virología , Humanos , Masculino , Persona de Mediana Edad , Valor Predictivo de las Pruebas , Prevalencia , Pronóstico , Reproducibilidad de los Resultados , Medición de Riesgo , Factores de Riesgo , Tuberculosis/diagnóstico , Tuberculosis/epidemiología , Tuberculosis/microbiología
2.
BMC Med ; 18(1): 19, 2020 02 11.
Artículo en Inglés | MEDLINE | ID: mdl-32041583

RESUMEN

BACKGROUND: Undiagnosed tuberculosis (TB) remains the most common cause of HIV-related mortality. Xpert MTB/RIF (Xpert) is being rolled out globally to improve TB diagnostic capacity. However, previous Xpert impact trials have reported that health system weaknesses blunted impact of this improved diagnostic tool. During phased Xpert rollout in Botswana, we evaluated the impact of a package of interventions comprising (1) additional support for intensified TB case finding (ICF), (2) active tracing for patients missing clinic appointments to support retention, and (3) Xpert replacing sputum-smear microscopy, on early (6-month) antiretroviral therapy (ART) mortality. METHODS: At 22 clinics, ART enrollees > 12 years old were eligible for inclusion in three phases: a retrospective standard of care (SOC), prospective enhanced care (EC), and prospective EC plus Xpert (EC+X) phase. EC and EC+X phases were implemented as a stepped-wedge trial. Participants in the EC phase received SOC plus components 1 (strengthened ICF) and 2 (active tracing) of the intervention package, and participants in the EC+X phase received SOC plus all three intervention package components. Primary and secondary objectives were to compare all-cause 6-month ART mortality between SOC and EC+X and between EC and EC+X phases, respectively. We used adjusted analyses, appropriate for study design, to control for baseline differences in individual-level factors and intra-facility correlation. RESULTS: We enrolled 14,963 eligible patients: 8980 in SOC, 1768 in EC, and 4215 in EC+X phases. Median age of ART enrollees was 35 and 64% were female. Median CD4 cell count was lower in SOC than subsequent phases (184/µL in SOC, 246/µL in EC, and 241/µL in EC+X). By 6 months of ART, 461 (5.3%) of SOC, 54 (3.2%) of EC, and 121 (3.0%) of EC+X enrollees had died. Compared with SOC, 6-month mortality was lower in the EC+X phase (adjusted hazard ratio, 0.77; 95% confidence interval, 0.61-0.97, p = 0.029). Compared with EC enrollees, 6-month mortality was similar among EC+X enrollees. CONCLUSIONS: Interventions to strengthen ICF and retention were associated with lower early ART mortality. This new evidence highlights the need to strengthen ICF and retention in many similar settings. Similar to other trials, no additional mortality benefit of replacing sputum-smear microscopy with Xpert was observed. TRIAL REGISTRATION: Retrospectively registered: ClinicalTrials.gov (NCT02538952).


Asunto(s)
Antirretrovirales/uso terapéutico , Mycobacterium tuberculosis/efectos de los fármacos , Tuberculosis/tratamiento farmacológico , Adulto , Botswana , Femenino , Humanos , Masculino , Tamizaje Masivo , Estudios Prospectivos , Análisis de Supervivencia , Tuberculosis/mortalidad
3.
Exp Neurol ; 320: 112962, 2019 10.
Artículo en Inglés | MEDLINE | ID: mdl-31125548

RESUMEN

Cervical spinal cord injury (SCI) impairs arm and hand function largely by interrupting descending tracts. Most SCI spare some axons at the lesion, including the corticospinal tract (CST), which is critical for voluntary movement. We targeted descending motor connections with paired electrical stimulation of motor cortex and cervical spinal cord in the rat. We sought to replicate the previously published effects of intermittent theta burst stimulation of forelimb motor cortex combined with trans-spinal direct current stimulation placed on the skin over the neck to target the cervical enlargement. We hypothesized that paired stimulation would improve performance in skilled walking and food manipulation (IBB) tasks. Rats received a moderate C4 spinal cord contusion injury (200 kDynes), which ablates the main CST. They were randomized to receive paired stimulation for 10 consecutive days starting 11 days after injury, or no stimulation. Behavior was assessed weekly from weeks 4-7 after injury, and then CST axons were traced. Rats with paired cortical and spinal stimulation achieved significantly better forelimb motor function recovery, as measured by fewer stepping errors on the horizontal ladder task (34 ±â€¯9% in stimulation group vs. 51 ±â€¯18% in control, p = .013) and higher scores on the food manipulation task (IBB, 0-9 score; 7.2 ±â€¯0.8 in stimulated rats vs. 5.2 ±â€¯2.6 in controls, p = .025). The effect size for both tasks was large (Cohen's d = 1.0 and 0.92, respectively). The CST axon length in the cervical spinal cord did not differ significantly between the groups, but there was denser and broader ipsilateral axons distribution distal to the spinal cord injury. The large behavioral effect and replication in an independent laboratory validate this approach, which will be trialed in cats before being tested in people using non-invasive methods.


Asunto(s)
Médula Cervical/fisiopatología , Estimulación Eléctrica/métodos , Actividad Motora/fisiología , Corteza Motora/fisiopatología , Traumatismos de la Médula Espinal/fisiopatología , Animales , Método Doble Ciego , Miembro Anterior , Ratas , Recuperación de la Función/fisiología
4.
BMC Health Serv Res ; 19(1): 46, 2019 Jan 18.
Artículo en Inglés | MEDLINE | ID: mdl-30658625

RESUMEN

BACKGROUND: Despite progress towards achieving UNAIDS 90-90-90 goals, barriers persist in laboratory systems in sub-Saharan Africa (SSA) restricting scale up of early infant diagnosis (EID) and viral load (VL) test monitoring of patients on antiretroviral therapy. If these facilities and system challenges persist, they may undermine recorded gains and appropriate management of patients. The aim of this review is to identify Public Private Partnerships (PPP) in SSA that have resolved systemic barriers within the VL and EID treatment cascade and demonstrated impact in the scale up of VL and EID. METHODS: We queried five HIV and TB laboratory databases from 2007 to 2017 for studies related to laboratory system strengthening and PPP. We identified, screened and included PPPs that demonstrated evidence in alleviating known system level barriers to scale up national VL and EID testing programs. PPPs that improved associated systems from the point of viral load test request to the use of the test result for patient management were deemed eligible. RESULTS: We identified six PPPs collaborations with multiple activities in select countries that are contributing to address challenges to scale up national viral load programs. One of the six PPPs reached 14.5 million patients in remote communities and transported up to 400,000 specimens in a year. Another PPP enabled an unprecedented 94% of specimens to reach national laboratory through improved sample referral network and enabled a cost savings of 62%. Also PPPs reduced cost of reagents and enabled 300,000 tested infants to be enrolled in care as well as reduced turnaround time of reporting results by 50%. CONCLUSIONS: Our review identified the benefits, enabling factors, and associated challenges for public and private sectors to engage in PPPs. PPP contributions to laboratory systems strengthening are a model and present opportunities that can be leveraged to strengthen systems to achieve the UNAIDS 90-90-90 treatment targets for HIV/AIDS. Despite growing emphasis on engaging the private sector as a critical partner to address global disease burden, PPPs that specifically strengthen laboratories, the cornerstone of public health programs, remain largely untapped.


Asunto(s)
Objetivos , Infecciones por VIH/tratamiento farmacológico , Asociación entre el Sector Público-Privado , United States Agency for International Development , África del Sur del Sahara , Bases de Datos Factuales , Atención a la Salud , Diagnóstico Precoz , VIH , Humanos , Lactante , Laboratorios , Pruebas Serológicas , Estados Unidos , Carga Viral
5.
Clin Microbiol Rev ; 32(1)2019 01.
Artículo en Inglés | MEDLINE | ID: mdl-30487166

RESUMEN

HIV diagnostics have played a central role in the remarkable progress in identifying, staging, initiating, and monitoring infected individuals on life-saving antiretroviral therapy. They are also useful in surveillance and outbreak responses, allowing for assessment of disease burden and identification of vulnerable populations and transmission "hot spots," thus enabling planning, appropriate interventions, and allocation of appropriate funding. HIV diagnostics are critical in achieving epidemic control and require a hybrid of conventional laboratory-based diagnostic tests and new technologies, including point-of-care (POC) testing, to expand coverage, increase access, and positively impact patient management. In this review, we provide (i) a historical perspective on the evolution of HIV diagnostics (serologic and molecular) and their interplay with WHO normative guidelines, (ii) a description of the role of conventional and POC testing within the tiered laboratory diagnostic network, (iii) information on the evaluations and selection of appropriate diagnostics, (iv) a description of the quality management systems needed to ensure reliability of testing, and (v) strategies to increase access while reducing the time to return results to patients. Maintaining the central role of HIV diagnostics in programs requires periodic monitoring and optimization with quality assurance in order to inform adjustments or alignment to achieve epidemic control.


Asunto(s)
Pruebas Diagnósticas de Rutina , Infecciones por VIH/diagnóstico , Pruebas Diagnósticas de Rutina/historia , Pruebas Diagnósticas de Rutina/tendencias , VIH , Infecciones por VIH/prevención & control , Historia del Siglo XX , Historia del Siglo XXI , Humanos
6.
PLoS Med ; 15(9): e1002658, 2018 09.
Artículo en Inglés | MEDLINE | ID: mdl-30216354

RESUMEN

In a Perspective on the research article from Jacobson and colleagues, Amitabh Suthar and colleagues from the Centers for Disease Control and Prevention discuss the importance of and considerations for developing real-time and large-scale reporting systems for tracking and controlling antimicrobial resistance.


Asunto(s)
Farmacorresistencia Microbiana , Vigilancia en Salud Pública/métodos , Tuberculosis Resistente a Múltiples Medicamentos/microbiología , Farmacorresistencia Bacteriana , Humanos , Pruebas de Sensibilidad Microbiana , Programas Nacionales de Salud/tendencias , Tuberculosis Resistente a Múltiples Medicamentos/diagnóstico , Tuberculosis Resistente a Múltiples Medicamentos/tratamiento farmacológico
7.
J Infect Dis ; 213 Suppl 2: S41-6, 2016 Apr 15.
Artículo en Inglés | MEDLINE | ID: mdl-27025697

RESUMEN

BACKGROUND: Diagnosis of multidrug-resistant tuberculosis and prompt initiation of effective treatment rely on access to rapid and reliable drug-susceptibility testing. Efficient specimen transport systems and appropriate training on specimen referral contribute to optimal and timely access to tuberculosis diagnostic services. METHODS: With support and technical assistance from a public-private partnership (PPP) between Becton Dickinson and the US President's Emergency Plan for AIDS Relief, the Uganda National TB Reference Laboratory (NTRL) and National TB and Leprosy Program redesigned the tuberculosis specimen transport network and trained healthcare workers with the goal of improving multidrug-resistant tuberculosis detection. RESULTS: Between 2008 and 2011, the PPP mapped 93% of health facilities and trained 724 healthcare and postal staff members covering 72% of districts. Strengthening the tuberculosis specimen referral system increased referrals from presumptive multidrug-resistant tuberculosis cases by >10-fold, with 94% of specimens reaching the NTRL within the established target transport time. CONCLUSIONS: This study demonstrates the potential of PPP collaborations with ministries of health to positively influence patient care by strengthening laboratory systems through increased access to drug-susceptibility testing in Uganda. Ongoing efforts to integrate specimen transport networks will maximize resources and improve patient management.


Asunto(s)
Instituciones de Salud , Laboratorios/organización & administración , Mycobacterium tuberculosis/aislamiento & purificación , Asociación entre el Sector Público-Privado , Manejo de Especímenes , Tuberculosis/diagnóstico , Atención a la Salud/organización & administración , Personal de Salud/educación , Necesidades y Demandas de Servicios de Salud , Humanos , Laboratorios/normas , Pruebas de Sensibilidad Microbiana , Programas Nacionales de Salud , Derivación y Consulta , Tuberculosis/microbiología , Tuberculosis Resistente a Múltiples Medicamentos/diagnóstico , Tuberculosis Resistente a Múltiples Medicamentos/microbiología , Uganda
8.
J Nutr ; 141(1): 131-6, 2011 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-21106932

RESUMEN

Exotic mushrooms have been used in ancient Chinese medicine due to their immunomodulatory properties for the treatment and/or prevention of chronic diseases. However, only limited data exist on the health benefits of white button mushrooms (WBM), the most common in the American diet. In the current study, we investigated the effects of WBM and shiitake mushrooms (SM) on collagen-induced arthritis (CIA) using a 2 x 3 factorial design in 8-wk-old female dilute brown non-agouti mice that were fed a control diet (n = 37) or the same diet supplemented with 5% lyophilized WBM or SM (n = 27) for 6 wk. CIA was induced by immunizing mice with 100 µg bovine collagen followed by 50 µg LPS on d 20 post-collagen injection. CIA was assessed by mononuclear cell infiltration, bone erosion, plasma IL-6, TNFα, and intercellular adhesion molecule-1 (sICAM-1) concentrations. Compared with the control diet, WBM and SM tended to reduce the CIA index from 5.11 ± 0.82 to 3.15 ± 0.95 (P = 0.06) (median, 6-9 to 1-2) 31 d post-collagen injection. Whereas 58% of control mice had a CIA index ≥ 7, only 23% of WBM and 29% of SM mice did (P = 0.1). Although both types of mushrooms reduced plasma TNFα (34%, WBM; 64%, SM), only SM increased plasma IL-6 by 1.3-fold (P < 0.05). The CIA index was positively correlated with sICAM1 (r = 0.55; P < 0.05) but negatively correlated with TNFα (r = 0.34; P < 0.05). Whether mushrooms are beneficial for arthritis management remains to be investigated. To our knowledge, this is the first report demonstrating a possible health benefit of WBM in arthritis treatment.


Asunto(s)
Agaricus , Artritis Experimental/prevención & control , Hongos Shiitake , Animales , Artritis Experimental/patología , Peso Corporal , Huesos/patología , Femenino , Incidencia , Molécula 1 de Adhesión Intercelular/análisis , Interleucina-6/sangre , Leucocitos Mononucleares/fisiología , Ratones , Ratones Endogámicos DBA , Análisis de Regresión , Factor de Necrosis Tumoral alfa/sangre
9.
Clin Immunol ; 136(2): 257-68, 2010 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-20462799

RESUMEN

We investigated whether circulating monocytes from patients with systemic juvenile idiopathic arthritis (SJIA) are resistant to apoptosis and which apoptotic pathway(s) may mediate this resistance. A microarray analysis of peripheral blood mononuclear cells (PBMC) of SJIA samples and RT-PCR analysis of isolated monocytes showed that monocytes from active SJIA patients express transcripts that imply resistance to apoptosis. SJIA monocytes incubated in low serum show reduced annexin binding and diminished FasL up-regulation compared to controls. SJIA monocytes are less susceptible to anti-Fas-induced apoptosis and, upon activation of the mitochondrial pathway with staurosporine, show diminished Bid cleavage and Bcl-w down-regulation compared to controls. Exposure to SJIA plasma reduces responses to apoptotic triggers in normal monocytes. Thus, SJIA monocytes are resistant to apoptosis due to alterations in both the extrinsic and intrinsic apoptosis pathways, and circulating factors associated with active SJIA may confer this phenotype.


Asunto(s)
Apoptosis/fisiología , Artritis Juvenil/fisiopatología , Monocitos/fisiología , Adolescente , Anticuerpos/inmunología , Apoptosis/genética , Artritis Juvenil/sangre , Supervivencia Celular , Células Cultivadas , Niño , Proteína Ligando Fas/metabolismo , Perfilación de la Expresión Génica , Regulación de la Expresión Génica/fisiología , Humanos , Mitocondrias/metabolismo , Monocitos/citología , Receptor fas/inmunología
10.
Gynecol Oncol ; 116(1): 10-4, 2010 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-19875158

RESUMEN

OBJECTIVE: To study patterns of recurrence and survival outcomes in patients with surgical stage I, grade 3 endometrioid adenocarcinoma of the endometrium (EA) treated with various treatment modalities. METHODS: A retrospective multi-institutional study of surgical stage I, grade 3 EA patients diagnosed between 1988 and 2006 was performed. Demographic, clinicopathologic, treatment and outcome data were collected. After surgery, patients were treated with either observation or radiotherapy (vaginal brachytherapy, whole pelvic or both). RESULTS: One hundred seventy-six patients were collected with a median age of 68 years. Twenty-six (15%) were stage IA, 96 (54%) IB and 54 (31%) IC. Sixty-one patients (35%) had lymphovascular space invasion (LVSI) and a mean of 18.9 lymph nodes (LNs) was removed. Seventy-eight patients (44%) were observed while 98 (56%) were treated with radiotherapy, the majority (n=51) receiving brachytherapy. After a median follow-up of 58 months, 20 recurrences (11%) were noted. Ninety percent of recurrences occurred in Stage IB/IC patients. The median time to recurrence was 22.5 months (5-74.5) and 80% of recurrences were extra-pelvic. There was no significant difference in recurrence based upon treatment modality or LVSI. Majority of recurrences were not salvaged as 75% (12/16) died of their disease with a median time of recurrence to death of 8 months. CONCLUSIONS: Patients with stage IB/IC, grade 3 endometrioid adenocarcinoma have a significant risk for extra-pelvic recurrence. Most patients will not be salvaged and will succumb to their disease, suggesting that current loco-regional adjuvant treatment strategies are not optimal and evaluation of more systemic therapies is warranted.


Asunto(s)
Carcinoma Endometrioide/patología , Carcinoma Endometrioide/terapia , Neoplasias Endometriales/patología , Neoplasias Endometriales/terapia , Recurrencia Local de Neoplasia/patología , Adulto , Anciano , Anciano de 80 o más Años , Terapia Combinada , Supervivencia sin Enfermedad , Femenino , Humanos , Persona de Mediana Edad , Estadificación de Neoplasias , Estudios Retrospectivos , Resultado del Tratamiento
11.
Acad Emerg Med ; 13(5): 537-42, 2006 May.
Artículo en Inglés | MEDLINE | ID: mdl-16551776

RESUMEN

OBJECTIVES: To describe the prevalence of depressive symptoms in adolescents presenting to the emergency department (ED) and to describe their demographics and outcomes compared with adolescents endorsing low levels of depressive symptoms. METHODS: The Beck Depression Inventory-2nd edition (BDI-II) was used to screen all patients 13-19 years of age who presented to the ED during the period of study. The BDI-II is a 21-item self-report instrument used to measure the presence and severity of depressive symptoms in adolescents and adults. Demographics and clinical outcomes of screening-program participants were abstracted by chart review. Patients were categorized into one of four severity categories (minimal, mild, moderate, or severe) and one of three presenting complaint categories (medical, trauma, mental health). RESULTS: Four hundred eighty-seven patients were approached, and 351(72%) completed the screening protocol. Participants endorsed minimal (n = 192, 55%), mild (n = 52, 15%), moderate (n = 41, 11%), or severe depressive symptoms (n = 66, 19%). Those with moderate or severe depressive symptoms were more likely to be hospitalized. Of patients completing the BDI-II, 72% with psychiatric, 12% with traumatic, and 19% with medical chief complaints endorsed either moderate or severe depressive symptoms. CONCLUSIONS: Depressive symptoms are prevalent in this screening sample, regardless of presenting complaint. A substantial proportion of patients with nonpsychiatric chief complaints endorsed moderate or severe depressive symptoms. A screening program might allow earlier identification and referral of patients at risk for depression.


Asunto(s)
Conducta del Adolescente , Depresión/diagnóstico , Depresión/epidemiología , Servicio de Urgencia en Hospital/estadística & datos numéricos , Tamizaje Masivo/instrumentación , Tamizaje Masivo/estadística & datos numéricos , Pediatría/estadística & datos numéricos , Adolescente , Adulto , Distribución por Edad , Comorbilidad , Estudios Transversales , Depresión/clasificación , Femenino , Hospitalización/estadística & datos numéricos , Humanos , Modelos Logísticos , Masculino , Ohio/epidemiología , Participación del Paciente/estadística & datos numéricos , Prevalencia , Escalas de Valoración Psiquiátrica , Transporte de Pacientes/estadística & datos numéricos , Heridas y Lesiones/epidemiología
12.
Am J Hum Genet ; 77(4): 567-81, 2005 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-16175503

RESUMEN

The minor allele of the R620W missense single-nucleotide polymorphism (SNP) (rs2476601) in the hematopoietic-specific protein tyrosine phosphatase gene, PTPN22, has been associated with multiple autoimmune diseases, including rheumatoid arthritis (RA). These genetic data, combined with biochemical evidence that this SNP affects PTPN22 function, suggest that this phosphatase is a key regulator of autoimmunity. To determine whether other genetic variants in PTPN22 contribute to the development of RA, we sequenced the coding regions of this gene in 48 white North American patients with RA and identified 15 previously unreported SNPs, including 2 coding SNPs in the catalytic domain. We then genotyped 37 SNPs in or near PTPN22 in 475 patients with RA and 475 individually matched controls (sample set 1) and selected a subset of markers for replication in an additional 661 patients with RA and 1,322 individually matched controls (sample set 2). Analyses of these results predict 10 common (frequency >1%) PTPN22 haplotypes in white North Americans. The sole haplotype found to carry the previously identified W620 risk allele was strongly associated with disease in both sample sets, whereas another haplotype, identical at all other SNPs but carrying the R620 allele, showed no association. R620W, however, does not fully explain the association between PTPN22 and RA, since significant differences between cases and controls persisted in both sample sets after the haplotype data were stratified by R620W. Additional analyses identified two SNPs on a single common haplotype that are associated with RA independent of R620W, suggesting that R620W and at least one additional variant in the PTPN22 gene region influence RA susceptibility.


Asunto(s)
Artritis Reumatoide/genética , Variación Genética , Proteínas Tirosina Fosfatasas/genética , Secuencia de Bases , ADN/genética , Haplotipos , Humanos , Datos de Secuencia Molecular , Polimorfismo de Nucleótido Simple , Proteína Tirosina Fosfatasa no Receptora Tipo 22 , Factores de Riesgo
13.
J Bacteriol ; 187(15): 5214-23, 2005 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-16030215

RESUMEN

Several genetic systems that allow the use of iron-protoporphyrin IX (heme) have been described for the pathogenic bacterium Neisseria meningitidis. However, many questions about the process of heme acquisition and utilization remain to be answered. To isolate and analyze unidentified genes that play a role in heme iron uptake and utilization, a Himar1 transposon mutant library was screened in N. meningitidis serogroup A strain IR4162. One locus identified by transposon mutagenesis conferred protection against heme toxicity. A mutant with a deletion in a gene termed ght (gene of hydrophobic agent tolerance) within this locus was susceptible to heme and other hydrophobic agents compared to the parental strain. Transcriptional analysis indicated that ght is cotranscribed with an upstream open reading frame NMA2149. Uncharacterized orthologues of ght were identified in many other gram-negative bacteria. We present genetic evidence for the importance of ght in resistance to hydrophobic agents and its potential role in interaction with other hydrophobic agent resistance mechanisms within N. meningitidis.


Asunto(s)
Genes Bacterianos , Hemo/metabolismo , Hierro/metabolismo , Neisseria meningitidis/genética , Neisseria meningitidis/metabolismo , Secuencia de Aminoácidos , Prueba de Complementación Genética , Hemo/toxicidad , Metaloporfirinas/toxicidad , Datos de Secuencia Molecular , Neisseria meningitidis/efectos de los fármacos , Sistemas de Lectura Abierta , Alineación de Secuencia , Homología de Secuencia de Aminoácido
14.
Am J Hum Genet ; 75(2): 330-7, 2004 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-15208781

RESUMEN

Rheumatoid arthritis (RA) is the most common systemic autoimmune disease, affecting approximately 1% of the adult population worldwide, with an estimated heritability of 60%. To identify genes involved in RA susceptibility, we investigated the association between putative functional single-nucleotide polymorphisms (SNPs) and RA among white individuals by use of a case-control study design; a second sample was tested for replication. Here we report the association of RA susceptibility with the minor allele of a missense SNP in PTPN22 (discovery-study allelic P=6.6 x 10(-4); replication-study allelic P=5.6 x 10(-8)), which encodes a hematopoietic-specific protein tyrosine phosphatase also known as "Lyp." We show that the risk allele, which is present in approximately 17% of white individuals from the general population and in approximately 28% of white individuals with RA, disrupts the P1 proline-rich motif that is important for interaction with Csk, potentially altering these proteins' normal function as negative regulators of T-cell activation. The minor allele of this SNP recently was implicated in type 1 diabetes, suggesting that the variant phosphatase may increase overall reactivity of the immune system and may heighten an individual carrier's risk for autoimmune disease.


Asunto(s)
Artritis Reumatoide/genética , Mutación Missense , Polimorfismo de Nucleótido Simple , Proteínas Tirosina Fosfatasas/genética , Frecuencia de los Genes , Humanos , Datos de Secuencia Molecular , Especificidad de Órganos/fisiología , Proteína Tirosina Fosfatasa no Receptora Tipo 1 , ARN Mensajero/fisiología
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