Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 663
Filtrar
1.
Cereb Cortex ; 30(2): 587-596, 2020 03 21.
Artículo en Inglés | MEDLINE | ID: mdl-31216015

RESUMEN

Turner syndrome (TS) is a genetic disorder affecting approximately 1:2000 live-born females. It results from partial or complete X monosomy and is associated with a range of clinical issues including a unique cognitive profile and increased risk for certain behavioral problems. Structural neuroimaging studies in adolescents, adults, and older children with TS have revealed altered neuroanatomy but are unable to identify when in development differences arise. In addition, older children and adults have often been exposed to years of growth hormone and/or exogenous estrogen therapy with potential implications for neurodevelopment. The study presented here is the first to test whether brain structure is altered in infants with TS. Twenty-six infants with TS received high-resolution structural MRI scans of the brain at 1 year of age and were compared to 47 typically developing female and 39 typically developing male infants. Results indicate that the typical neuroanatomical profile seen in older individuals with TS, characterized by decreased gray matter volumes in premotor, somatosensory, and parietal-occipital cortex, is already present at 1 year of age, suggesting a stable phenotype with origins in the prenatal or early postnatal period.


Asunto(s)
Encéfalo/patología , Síndrome de Turner/patología , Encéfalo/diagnóstico por imagen , Femenino , Humanos , Lactante , Imagen por Resonancia Magnética , Tamaño de los Órganos , Síndrome de Turner/diagnóstico por imagen
2.
Haemophilia ; 22(4): 507-13, 2016 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-26936227

RESUMEN

BACKGROUND: The paradigm(™) 2 and 4 phase 3 clinical trials investigated the safety and efficacy of nonacog beta pegol, a recombinant glycoPEGylated factor IX (FIX) with extended half-life, in previously treated haemophilia B patients. AIM: These post hoc analyses investigated the bleeding patterns in target joints. METHODS: Patients randomized to 40 or 10 IU kg(-1) once weekly prophylaxis who had at least one target joint were included. Baseline demographics and disease-specific data were collected. Bleeding patterns were assessed, and an International Society on Thrombosis and Haemostasis (ISTH) definition of target joints was used. RESULTS: A total of 67% and 8% of patients in the 40 and 10 IU kg(-1) arm, respectively, did not experience target joint bleeds during the paradigm(™) 2 trial. Twenty-four target joints were recorded in each prophylaxis arm at baseline. During the paradigm(™) 2 trial, no bleeds were reported in 17 (71%) and 7 (29%) target joints in the 40 and 10 IU kg(-1) arms respectively. All target joint bleeds in the 40 IU kg(-1) once weekly prophylaxis arm were controlled with a single injection of 40 IU kg(-1) nonacog beta pegol. By the latest ISTH definition, 90% and 58% of target joints in the 40 and 10 IU kg(-1) arms, respectively, were no longer considered target joints at the end of the paradigm(™) 2 trial. At the end of the paradigm(™) 4 extension trial, all target joints in the 40 IU kg(-1) arm were no longer considered target joints. CONCLUSION: Routine prophylaxis with 40 IU kg(-1) once weekly nonacog beta pegol has the potential for effective management of target joint bleeds in haemophilia B patients.


Asunto(s)
Coagulantes/uso terapéutico , Factor IX/uso terapéutico , Hemofilia B/tratamiento farmacológico , Artropatías/fisiopatología , Polietilenglicoles/uso terapéutico , Adolescente , Adulto , Niño , Relación Dosis-Respuesta a Droga , Esquema de Medicación , Semivida , Hemorragia/prevención & control , Humanos , Artropatías/epidemiología , Masculino , Persona de Mediana Edad , Proteínas Recombinantes/uso terapéutico , Resultado del Tratamiento , Adulto Joven
3.
Evol Comput ; 23(3): 451-79, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-25781724

RESUMEN

The parameter-less population pyramid (P3) is a recently introduced method for performing evolutionary optimization without requiring any user-specified parameters. P3's primary innovation is to replace the generational model with a pyramid of multiple populations that are iteratively created and expanded. In combination with local search and advanced crossover, P3 scales to problem difficulty, exploiting previously learned information before adding more diversity. Across seven problems, each tested using on average 18 problem sizes, P3 outperformed all five advanced comparison algorithms. This improvement includes requiring fewer evaluations to find the global optimum and better fitness when using the same number of evaluations. Using both algorithm analysis and comparison, we find P3's effectiveness is due to its ability to properly maintain, add, and exploit diversity. Unlike the best comparison algorithms, P3 was able to achieve this quality without any problem-specific tuning. Thus, unlike previous parameter-less methods, P3 does not sacrifice quality for applicability. Therefore we conclude that P3 is an efficient, general, parameter-less approach to black box optimization which is more effective than existing state-of-the-art techniques.


Asunto(s)
Algoritmos , Modelos Teóricos , Teorema de Bayes , Ligamiento Genético
4.
Nature ; 505(7485): 654-6, 2014 Jan 30.
Artículo en Inglés | MEDLINE | ID: mdl-24476888

RESUMEN

Brown dwarfs--substellar bodies more massive than planets but not massive enough to initiate the sustained hydrogen fusion that powers self-luminous stars--are born hot and slowly cool as they age. As they cool below about 2,300 kelvin, liquid or crystalline particles composed of calcium aluminates, silicates and iron condense into atmospheric 'dust', which disappears at still cooler temperatures (around 1,300 kelvin). Models to explain this dust dispersal include both an abrupt sinking of the entire cloud deck into the deep, unobservable atmosphere and breakup of the cloud into scattered patches (as seen on Jupiter and Saturn). However, hitherto observations of brown dwarfs have been limited to globally integrated measurements, which can reveal surface inhomogeneities but cannot unambiguously resolve surface features. Here we report a two-dimensional map of a brown dwarf's surface that allows identification of large-scale bright and dark features, indicative of patchy clouds. Monitoring suggests that the characteristic timescale for the evolution of global weather patterns is approximately one day.

5.
Respiration ; 84(4): 306-11, 2012.
Artículo en Inglés | MEDLINE | ID: mdl-22846608

RESUMEN

BACKGROUND: The forced vital capacity (FVC) is an established measure in amyotrophic lateral sclerosis (ALS) clinical trials. Recently the sniff nasal inspiratory pressure (SNIP) test has been increasingly used as a respiratory measure. OBJECTIVES: It was the aim of this study to assess the feasibility of SNIP as an outcome measure in a phase III clinical trial with a lead-in design. METHODS: Twenty patients were enrolled in a randomized clinical trial. FVC, SNIP in sitting (SNIPsitt) and supine (SNIPsup) positions, and the ALS functional rating scale score (ALSFRS-R) were measured every 4 weeks. RESULTS: Complete data were available for 19 patients over 5 months. Baseline values were normal for FVC (101 ± 14%) but abnormal for SNIPsitt and SNIPsup (84 ± 34% and 82 ± 33%). While FVC and ALSFRS-R declined in parallel, SNIPsitt measures declined significantly less compared to ALSFRS-R (p < 0.05) and FVC (p < 0.001) up to 4 months after enrollment. Over 50% of patients still had values equal to or above baseline SNIPsitt measures after 3 months despite abnormal baseline values. CONCLUSIONS: The delayed decline in SNIP measurements suggests a learning effect over time. The optimal number of SNIPs in ALS clinical trials has yet to be determined. SNIP measures should be used with caution in trials with a lead-in design.


Asunto(s)
Esclerosis Amiotrófica Lateral/fisiopatología , Inhalación , Nariz/fisiopatología , Presión , Adulto , Anciano , Estudios de Factibilidad , Femenino , Humanos , Masculino , Persona de Mediana Edad , Evaluación de Resultado en la Atención de Salud , Postura , Capacidad Vital
6.
Ann Oncol ; 22(12): 2610-2615, 2011 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-21415234

RESUMEN

BACKGROUND: Lapatinib (GW572016) is a dual tyrosine kinase inhibitor of epidermal growth factor receptor (EGFR) and human epidermal growth factor receptor 2 (HER2/ErbB2), which are reported as overexpressed in 15%-45% of gastric cancers, making them potential targets. PATIENTS AND METHODS: The primary objective of this study was to assess response rate. Secondary objectives included overall survival (OS), toxicity, and the relationship of EGFR, ErbB2, and markers of angiogenesis with clinical outcome. Lapatinib was administered to chemonaive metastatic gastric cancer patients at a dose of 1500 mg orally daily for 28 days. RESULTS: The study enrolled 47 patients from February 2005 until May 2006. Four patients (9%) had a confirmed partial response (PR), 1 (2%) had an unconfirmed PR, and 10 (23%) had stable disease. Median (95% confidence interval) time to treatment failure was 1.9 (1.6-3.1) months and OS was 4.8 (3.2-7.4) months. Significant adverse events: one grade 4 cardiac ischemia/infarction, one grade 4 fatigue, and one grade 4 emesis. One treatment-related death was due to central nervous system ischemia. An exploratory analysis of markers revealed gene expression of HER2, interleukin (IL)-8 and genomic polymorphisms IL-8, and vascular endothelial growth factor correlated with OS. CONCLUSIONS: Lapatinib is well tolerated, with modest single-agent activity in advanced/metastatic gastric cancer patients. Potential molecular correlatives were identified which warrant further validation.


Asunto(s)
Adenocarcinoma/tratamiento farmacológico , Antineoplásicos/uso terapéutico , Biomarcadores de Tumor/genética , Quinazolinas/uso terapéutico , Neoplasias Gástricas/tratamiento farmacológico , Adenocarcinoma/genética , Adenocarcinoma/mortalidad , Adenocarcinoma/secundario , Adulto , Anciano , Anciano de 80 o más Años , Biomarcadores de Tumor/metabolismo , Femenino , Expresión Génica , Humanos , Estimación de Kaplan-Meier , Lapatinib , Masculino , Persona de Mediana Edad , Polimorfismo Genético , Neoplasias Gástricas/genética , Neoplasias Gástricas/mortalidad , Neoplasias Gástricas/patología , Resultado del Tratamiento
7.
Vet Pathol ; 48(4): 896-902, 2011 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-20724516

RESUMEN

Damaraland mole rats (Cryptomys damarensis) are among the longest-living rodents, with a maximum longevity of approximately 16 years. As one of the few mammals termed eusocial, these animals have been used in behavioral, genetic, metabolic, and physiologic research at the University of Connecticut since 1997. For individual identification at 3 to 4 months of age, mole rats were subcutaneously implanted with microchip transponders (11 mm in length) in the dorsal cervical region. In 2007, 2 of the 90 implanted adults, 10-year-old and 9-year-old females, developed subcutaneous masses at the site of the implant. Histopathological and immunohistochemical examinations revealed amelanotic melanoma and fibrosarcoma, respectively, with metastasis of the amelanotic melanoma. In 2008, a total of 3 adult males were castrated as part of a sex behavior study; 3 months later, all 3 castrated males developed subcutaneous masses around their implants, whereas none of the noncastrated males had masses. After an additional 9 months, these masses were found to be granulomas. To the authors' knowledge, this is the first report of neoplasia in this species. Both the tumors and the granulomas surrounded the microchip transponder.


Asunto(s)
Sistemas de Identificación Animal/veterinaria , Granuloma/veterinaria , Ratas Topo , Neoplasias/veterinaria , Prótesis e Implantes/efectos adversos , Enfermedades de los Roedores/etiología , Sistemas de Identificación Animal/instrumentación , Animales , Femenino , Granuloma/etiología , Granuloma/patología , Masculino , Neoplasias/etiología , Neoplasias/patología , Enfermedades de los Roedores/patología
8.
J Neurol Neurosurg Psychiatry ; 81(10): 1135-40, 2010 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-20498181

RESUMEN

BACKGROUND: Many patients with amyotrophic lateral sclerosis (ALS) experience cramps during the course of the disease but so far, none of the medications used has been of proven benefit. The objective was to determine the effect of orally administered tetrahydrocannabinol (THC) on cramps in ALS patients. METHODS: The authors conducted a randomised, double-blind, placebo-controlled crossover trial in 27 ALS patients suffering from moderate to severe (visual analogue scale (VAS); VAS≥4) daily cramps. There were 7 women and 20 men with a mean age of 57 years and a mean functional ALS score (ALSFRS-R) of 38.4. Patients were randomly assigned to receive 5 mg THC twice daily followed by placebo or vice versa. Each treatment period lasted for 2 weeks and was preceded by a 2-week drug-free observation period (run-in, wash-out period respectively). The primary outcome measure was change in cramp intensity as assessed by a VAS. Secondary outcome measures included the number of cramps per day, number of cramps during daytime and bedtime, intensity of fasciculations (VAS) as well as validated measures of quality of life (ALSAQ-40), quality of sleep (SDQ), appetite (FAACT) and depression (HADS). RESULTS: Complete data were available from 22 patients. THC was well tolerated. There was no evidence for a treatment effect on cramp intensity, number of cramps, fasciculation intensity or any of the other secondary outcome measures. CONCLUSIONS: This interventional study with orally administered THC 5 mg twice daily did not demonstrate subjective improvement of cramp intensity in ALS patients.


Asunto(s)
Esclerosis Amiotrófica Lateral/tratamiento farmacológico , Dronabinol/uso terapéutico , Calambre Muscular/tratamiento farmacológico , Adulto , Anciano , Esclerosis Amiotrófica Lateral/complicaciones , Apetito/efectos de los fármacos , Estudios Cruzados , Depresión/tratamiento farmacológico , Método Doble Ciego , Femenino , Humanos , Masculino , Persona de Mediana Edad , Calambre Muscular/complicaciones , Calidad de Vida , Índice de Severidad de la Enfermedad , Trastornos del Sueño-Vigilia/complicaciones , Trastornos del Sueño-Vigilia/tratamiento farmacológico
9.
Ann Oncol ; 21(6): 1196-1202, 2010 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-19875761

RESUMEN

BACKGROUND: The purpose was to examine the prognostic impact of features of tumor cells and immune microenvironment in patients with follicular lymphoma treated with and without anti-CD20 monoclonal antibody therapy. PATIENTS AND METHODS: Tissue microarrays were constructed from archived tissue obtained from patients on three sequential Southwest Oncology Group (SWOG) trials for FL. All three trials included anthracycline-based chemotherapy. Anti-CD20 monoclonal antibodies were included for patients in the latter two trials. Immunohistochemistry was used to study the number and distribution of cells staining for forkhead box protein P3 (FOXP3) and lymphoma-associated macrophages (LAMs) and the number of lymphoma cells staining for myeloma-associated antigen-1 (MUM-1). Cox proportional hazards regression was used to evaluate the association between marker expression and overall survival (OS). RESULTS: The number or pattern of infiltrating FOXP3 cells and LAMs did not correlate with OS in sequential SWOG studies for FL. The presence of MUM-1 correlated with lower OS for patients who received monoclonal antibody but not for those treated with chemotherapy alone. CONCLUSIONS: Immune cell composition of lymph nodes did not correlate with OS in this analysis of trials in FL. The mechanism of the observed correlation between MUM-1 expression and adverse prognosis in patients receiving monoclonal antibody therapy requires confirmation.


Asunto(s)
Anticuerpos Monoclonales/uso terapéutico , Factores Reguladores del Interferón/metabolismo , Linfoma Folicular/diagnóstico , Linfoma Folicular/terapia , Macrófagos/patología , Linfocitos T Reguladores/patología , Adulto , Anciano , Recuento de Células Sanguíneas , Ensayos Clínicos Fase II como Asunto , Terapia Combinada , Femenino , Humanos , Inmunoterapia/métodos , Linfoma Folicular/inmunología , Linfoma Folicular/metabolismo , Macrófagos/metabolismo , Masculino , Oncología Médica/métodos , Persona de Mediana Edad , Valor Predictivo de las Pruebas , Pronóstico , Ensayos Clínicos Controlados Aleatorios como Asunto , Sudoeste de Estados Unidos , Linfocitos T Reguladores/efectos de los fármacos , Linfocitos T Reguladores/metabolismo
10.
Clin Nephrol ; 71(1): 59-62, 2009 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-19203551

RESUMEN

Membranous glomerulonephritis and minimal change disease are the most common forms of glomerular diseases noted in patients with graft versus host disease after hematopoietic stem cell transplantation. Herein, we report a patient who developed anti-neutrophil cytoplasmic antibody associated crescentic IgA nephropathy within 3 months after autologous hematopoietic stem cell transplantation. He was treated with intravenous pulse steroids and monthly intravenous cyclophosphamide for 6 months followed by cyclophosphamide every 3 months and tapering dose of steroids. His proteinuria resolved and renal function remained stable. Two cases of crescentic IgA nephropathy have been reported in patients who underwent allogenic hematopoietic stem cell transplantation. The etiology of IgA nephropathy developing after hematopoietic stem cell transplantation is unclear and larger registry-based studies are needed to further explore this condition.


Asunto(s)
Anticuerpos Anticitoplasma de Neutrófilos/fisiología , Glomerulonefritis por IGA/diagnóstico , Glomerulonefritis por IGA/etiología , Trasplante de Células Madre Hematopoyéticas/efectos adversos , Enfermedad de Hodgkin/terapia , Glomerulonefritis por IGA/terapia , Humanos , Masculino , Persona de Mediana Edad
11.
Neuroscience ; 155(3): 809-17, 2008 Aug 26.
Artículo en Inglés | MEDLINE | ID: mdl-18582538

RESUMEN

Naked mole-rats are highly social rodents that live in large colonies characterized by a rigid social and reproductive hierarchy. Only one female, the queen, breeds. Most colony members are non-reproductive subordinates that work cooperatively to rear the young and maintain an underground burrow system. Little is known about the neurobiological basis of the complex sociality exhibited by this species. The neuropeptide oxytocin (Oxt) modulates social bonding and other social behaviors in many vertebrates. Here we examined the distribution of Oxt immunoreactivity in the brains of male and female naked mole-rats. As in other species, the majority of Oxt-immunoreactive (Oxt-ir) cells were found in the paraventricular and supraoptic nuclei, with additional labeled cells scattered throughout the preoptic and anterior hypothalamic areas. Oxt-ir fibers were found traveling toward and through the median eminence, as well as in the tenia tecta, septum, and nucleus of the diagonal band of Broca. A moderate network of fibers covered the bed nucleus of the stria terminalis and preoptic area, and a particularly dense fiber innervation of the nucleus accumbens and substantia innominata was observed. In the brainstem, Oxt-ir fibers were found in the periaqueductal gray, locus coeruleus, parabrachial nucleus, nucleus of the solitary tract, and nucleus ambiguus. The high levels of Oxt immunoreactivity in the nucleus accumbens and preoptic area are intriguing, given the link in other rodents between Oxt signaling in these regions and maternal behavior. Although only the queen gives birth or nurses pups in a naked mole-rat colony, most individuals actively participate in pup care.


Asunto(s)
Encéfalo/metabolismo , Oxitocina/metabolismo , Animales , Encéfalo/anatomía & histología , Mapeo Encefálico , Ratas Topo/anatomía & histología , Ratas Topo/metabolismo
12.
Eur J Vasc Endovasc Surg ; 34(3): 340-6, 2007 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-17582795

RESUMEN

OBJECTIVES: To assess the effects of intermittent limb compression on arterial collateral formation in a rabbit-model. DESIGN: Animal study. MATERIAL AND METHODS: New Zealand rabbits (n=11), aged 2-years, weight of at least 4.0 kg, underwent bilateral superficial femoral artery ligation. In ten of these, the experimental leg underwent 60 minutes of daily intermittent compression for a ten week period with 3 sec/90 mmHg pressure inflation and a cycle of 3 times per minute. The contra-lateral limbs were not treated. At the end of the ten-week period, high-resolution angiograms were obtained by barium infusion into the aorta. The angiograms were analyzed in a blinded manner and the number of collateral arteries larger than 100 microns, was counted. Following perfusion-fixation, histological specimens of transverse sections of the compressed semi-membranous muscle were examined. RESULTS: The compressed limbs demonstrated a significantly (8.1+/-.87 vs 6.0+/-.97; p<0.005) greater number of collateral vessels, ranging in size from 100-700 microns, as compared to the control sides. The mean size of collaterals in the compressed limbs was not significantly different (0.33+/-0.17 vs 0.31+/-0.16). Microscopic examination of the collaterals confirmed remodeling by a typical neo-intima consisting of 6-7 cell-layers. CONCLUSIONS: Intermittent limb compression increases the number of angiographical collateral arteries.


Asunto(s)
Arteriopatías Oclusivas/diagnóstico por imagen , Arteriopatías Oclusivas/fisiopatología , Circulación Colateral , Arteria Femoral/diagnóstico por imagen , Arteria Femoral/fisiopatología , Músculo Esquelético/irrigación sanguínea , Neovascularización Fisiológica , Animales , Sulfato de Bario/administración & dosificación , Medios de Contraste/administración & dosificación , Modelos Animales de Enfermedad , Arteria Femoral/cirugía , Aparatos de Compresión Neumática Intermitente , Ligadura , Presión , Conejos , Radiografía , Reproducibilidad de los Resultados , Factores de Tiempo
13.
J Med Genet ; 44(2): e56, 2007 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-17407838

RESUMEN

BACKGROUND: Despite advances in the characterisation of mutations in the MECP2-coding region, a small proportion of classic RTT cases remain without recognisable mutations. OBJECTIVE AND METHODS: To identify previously unknown mutations, a quantitative assay was established, providing estimates of MECP2_e1 and MECP2_e2 expression levels in peripheral blood. A systematic analysis of an Israeli cohort of 82 patients with classic and atypical RTT is presented, including sequence analysis of the MECP2-coding region, MLPA, XCI and quantitative expression assays. RESULTS AND CONCLUSION: A novel mis-sense mutation at ca 453C-->T (pD151E), resulting in a change of a conserved residue at the methyl-binding domain, and a rare GT deletion of intron 1 donor splice site are reported. It is shown that various MECP2 mutations had distinct effects on MECP2 expression levels in peripheral blood. The most significant (p<0.001) reduction in the expression of both MECP2 isoforms was related to the presence of the intron 1 donor splice-site mutation. Using quantitative expression assays, it was shown that several patients with classic and atypical RTT with no mutation findings had significantly lower MECP2 expression levels. Further research on these patients may disclose still elusive non-coding regulatory MECP2 mutations.


Asunto(s)
Proteína 2 de Unión a Metil-CpG/genética , Síndrome de Rett/genética , Cromosomas Humanos X , Estudios de Cohortes , Secuencia Conservada , ADN/genética , ADN/aislamiento & purificación , Femenino , Regulación de la Expresión Génica , Humanos , Israel , Masculino , Mutación Missense , Polimorfismo de Nucleótido Simple , Isoformas de Proteínas/genética , ARN/genética , ARN/aislamiento & purificación
14.
Int J Dermatol ; 46(1): 64-7, 2007 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-17214724

RESUMEN

BACKGROUND: Darier's disease (DD) is an autosomal dominant skin disorder characterized by abnormal keratinization and acantholysis. Deleterious mutations in the gene ATP2A2 which encodes SERCA2, a calcium pump of the sarco/endoplasmic reticulum underlie the disease. OBJECTIVE: To identify the genetic defect in two Jewish families of eastern-European ancestry with DD. METHODS: DNA was extracted from peripheral blood of six patients and three healthy members of the two families. Polymerase chain reaction (PCR) was carried out to amplify the exons and flanking intron boundaries of the ATP2A2 gene followed by direct sequencing. Restriction fragment analysis verified the presence or absence of the mutations. Results Two novel mutations were identified. A nonsense mutation, a change of C391 to T (R131X) in exon 5, was found in one family and a missense mutation, a change of A530 to C (Q177P) in the second. The mutations were not present in 50 healthy individuals of the same ethnic origin. Both pathogenic mutations are in codons that are located in a highly conserved cytoplasmic beta-strand domain which functions as the transduction site. CONCLUSION: The existence of two mutations in two Jewish families of the same ancestry might confirm the previously published reports that most mutations in that gene are private.


Asunto(s)
Enfermedad de Darier/genética , Judíos/genética , ATPasas Transportadoras de Calcio del Retículo Sarcoplásmico/genética , Adulto , Codón sin Sentido , Enfermedad de Darier/etnología , Femenino , Humanos , Lactante , Masculino , Mutación Missense , Linaje , Reacción en Cadena de la Polimerasa
15.
J Med Genet ; 43(12): e56, 2006 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-17142618

RESUMEN

BACKGROUND: Despite advances in the characterisation of mutations in the MECP2-coding region, a small proportion of classic RTT cases remain without recognisable mutations. OBJECTIVE AND METHODS: To identify previously unknown mutations, a quantitative assay was established, providing estimates of MECP2_e1 and MECP2_e2 expression levels in peripheral blood. A systematic analysis of an Israeli cohort of 82 patients with classic and atypical RTT is presented, including sequence analysis of the MECP2-coding region, MLPA, XCI and quantitative expression assays. RESULTS AND CONCLUSION: A novel mis-sense mutation at ca 453C-->T (pD151E), resulting in a change of a conserved residue at the methyl-binding domain, and a rare GT deletion of intron 1 donor splice site are reported. It is shown that various MECP2 mutations had distinct effects on MECP2 expression levels in peripheral blood. The most significant (p<0.001) reduction in the expression of both MECP2 isoforms was related to the presence of the intron 1 donor splice-site mutation. Using quantitative expression assays, it was shown that several patients with classic and atypical RTT with no mutation findings had significantly lower MECP2 expression levels. Further research on these patients may disclose still elusive non-coding regulatory MECP2 mutations.


Asunto(s)
Expresión Génica/genética , Proteína 2 de Unión a Metil-CpG/genética , Mutación/genética , Síndrome de Rett/genética , Adolescente , Adulto , Niño , Preescolar , Estudios de Cohortes , Análisis Mutacional de ADN/métodos , Humanos , Israel , Proteína 2 de Unión a Metil-CpG/sangre , Proteína 2 de Unión a Metil-CpG/deficiencia , Reproducibilidad de los Resultados , Síndrome de Rett/diagnóstico , Síndrome de Rett/metabolismo , Inactivación del Cromosoma X
16.
Proc Natl Acad Sci U S A ; 103(41): 15200-5, 2006 Oct 10.
Artículo en Inglés | MEDLINE | ID: mdl-17015832

RESUMEN

Myxobacteria are single-celled, but social, eubacterial predators. Upon starvation they build multicellular fruiting bodies using a developmental program that progressively changes the pattern of cell movement and the repertoire of genes expressed. Development terminates with spore differentiation and is coordinated by both diffusible and cell-bound signals. The growth and development of Myxococcus xanthus is regulated by the integration of multiple signals from outside the cells with physiological signals from within. A collection of M. xanthus cells behaves, in many respects, like a multicellular organism. For these reasons M. xanthus offers unparalleled access to a regulatory network that controls development and that organizes cell movement on surfaces. The genome of M. xanthus is large (9.14 Mb), considerably larger than the other sequenced delta-proteobacteria. We suggest that gene duplication and divergence were major contributors to genomic expansion from its progenitor. More than 1,500 duplications specific to the myxobacterial lineage were identified, representing >15% of the total genes. Genes were not duplicated at random; rather, genes for cell-cell signaling, small molecule sensing, and integrative transcription control were amplified selectively. Families of genes encoding the production of secondary metabolites are overrepresented in the genome but may have been received by horizontal gene transfer and are likely to be important for predation.


Asunto(s)
Evolución Molecular , Genoma Bacteriano , Myxococcus xanthus/genética , Deltaproteobacteria/genética , Deltaproteobacteria/fisiología , Datos de Secuencia Molecular , Familia de Multigenes , Myxococcus xanthus/crecimiento & desarrollo , Myxococcus xanthus/fisiología , ARN Ribosómico 16S/genética , Transducción de Señal/genética , Transducción de Señal/fisiología
17.
J Bacteriol ; 188(7): 2706-10, 2006 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-16547059

RESUMEN

The symbiotic pathogenic bacterium Xenorhabdus nematophila produces two distinct intracellular inclusion bodies. The pixA gene, which encodes the 185-residue methionine-rich PixA inclusion body protein, was analyzed in the present study. The pixA gene was optimally expressed under stationary-phase conditions but its expression did not require RpoS. Analysis of a pixA mutant strain showed that PixA was not required for virulence towards the insect host or for colonization of or survival within the nematode host, and was not essential for nematode reproduction. The pixA gene was not present in the genome of Xenorhabdus bovienii, which also produces proteinaceous inclusions, indicating that PixA is specifically produced in X. nematophila.


Asunto(s)
Proteínas Bacterianas/metabolismo , Cuerpos de Inclusión/metabolismo , Xenorhabdus/metabolismo , Animales , Proteínas Bacterianas/química , Proteínas Bacterianas/genética , Regulación Bacteriana de la Expresión Génica , Larva/parasitología , Manduca/parasitología , Mutagénesis Insercional , Nematodos/microbiología , Fenotipo , Xenorhabdus/genética
18.
Occup Environ Med ; 62(5): 309-17, 2005 May.
Artículo en Inglés | MEDLINE | ID: mdl-15837852

RESUMEN

AIMS: To characterise the development of noise induced damage to hearing. METHODS: Hearing and noise exposure were prospectively monitored among a cohort of newly enrolled construction industry apprentices and a comparison group of graduate students, using standard pure tone audiometry and distortion product otoacoustic emissions (DPOAEs). A total of 328 subjects (632 ears) were monitored annually an average of 3.4 times. In parallel to these measures, noise exposure and hearing protection device (HPD) use were extensively monitored during construction work tasks. Recreational/non-occupational exposures also were queried and monitored in subgroups of subjects. Trade specific mean exposure L(eq) levels, with and without accounting for the variable use of hearing protection in each trade, were calculated and used to group subjects by trade specific exposure level. Mixed effects models were used to estimate the change in hearing outcomes over time for each exposure group. RESULTS: Small but significant exposure related changes in DPOAEs over time were observed, especially at 4 kHz with stimulus levels (L1) between 50 and 75 dB, with less clear but similar patterns observed at 3 kHz. After controlling for covariates, the high exposure group had annual changes in 4 kHz emissions of about 0.5 dB per year. Pure tone audiometric thresholds displayed only slight trends towards increased threshold levels with increasing exposure groups. Some unexpected results were observed, including an apparent increase in DPOAEs among controls over time, and improvement in behavioural thresholds among controls at 6 kHz only. CONCLUSIONS: Results indicate that construction apprentices in their first three years of work, with average noise exposures under 90 dBA, have measurable losses of hearing function. Despite numerous challenges in using DPOAEs for hearing surveillance in an industrial setting, they appear somewhat more sensitive to these early changes than is evident with standard pure tone audiometry.


Asunto(s)
Trastornos de la Audición/etiología , Industrias , Ruido en el Ambiente de Trabajo/efectos adversos , Adulto , Audiometría de Tonos Puros/métodos , Umbral Auditivo , Femenino , Pérdida Auditiva Provocada por Ruido/etiología , Humanos , Masculino , Exposición Profesional/efectos adversos , Emisiones Otoacústicas Espontáneas/fisiología , Evaluación de Resultado en la Atención de Salud/métodos , Estudios Prospectivos , Factores de Tiempo
19.
Ann Rheum Dis ; 62(12): 1221-3, 2003 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-14644864

RESUMEN

BACKGROUND: Peripheral neuropathy is a prominent feature of the systemic and secondary vasculitides. Usually, it is responsive to corticosteroids, but in certain cases it may be resistant to corticosteroid or immunosuppressive treatment, or both. OBJECTIVE: To present patients who exhibited various inflammatory diseases accompanied with vasculitic peripheral neuropathies for which intravenous immunoglobulin (IVIg) was used for treatment. METHODS: Six patients with Sjögren's syndrome, systemic lupus erythematosus (SLE), vaccination induced vasculitis, Churg-Strauss vasculitis, mixed cryoglobulinaemia associated with hepatitis C infection, or sarcoidosis were included. All developed vasculitic peripheral neuropathy, and were treated with high dose IVIg (2 g/kg body weight). The patients were followed up for 1-5 years after this treatment. RESULTS: In four patients (Sjögren's syndrome, Churg-Strauss vasculitis, SLE, and vaccination induced vasculitis) the neuropathy resolved after IVIg treatment. CONCLUSION: IVIg may be beneficial in cases of resistant vasculitic peripheral neuropathy. IVIg should probably be considered as a sole or adjuvant treatment for patients with contraindications to conventional treatment, or alternatively, for patients in whom conventional treatment has failed.


Asunto(s)
Inmunoglobulinas Intravenosas/uso terapéutico , Enfermedades del Sistema Nervioso Periférico/terapia , Vasculitis/complicaciones , Adulto , Anciano , Niño , Síndrome de Churg-Strauss/complicaciones , Crioglobulinemia/complicaciones , Femenino , Hepatitis C/complicaciones , Humanos , Vacunas contra la Influenza/efectos adversos , Lupus Eritematoso Sistémico/complicaciones , Masculino , Persona de Mediana Edad , Enfermedades del Sistema Nervioso Periférico/complicaciones , Sarcoidosis/complicaciones , Síndrome de Sjögren/complicaciones
20.
J Heart Lung Transplant ; 22(11): 1234-44, 2003 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-14585385

RESUMEN

BACKGROUND: Hearts from non-heart-beating organ donors are not transplanted because of risk of ischemia-reperfusion injury. We tested whether pharmacologic pre-conditioning with adenosine and the Na(+)/H(+) exchanger inhibitor, cariporide, combined with controlled reperfusion, would prevent injury in porcine hearts that had sustained 30 minutes of hypoxia/ischemia in closed-chest animals. METHODS: Hearts from Yorkshire pigs (100 kg) were studied in 3 groups. Group 1 (control) hearts were surgically removed while beating. Group 2 hearts were harvested from animals made hypoxic by discontinuing mechanical ventilation for 30 minutes. Group 3 hearts were hypoxic as in Group 2, but these animals received adenosine (40 mg) and cariporide (400 mg) 10 minutes before stopping ventilation. Cardiac function in all groups was assessed ex vivo in a working heart apparatus in which pressure and flow measurements were made over 3 hours. Controlled reperfusion in Group 3 hearts used leukocyte-depleted blood perfusate containing free radical scavengers. Myocardial injury was assessed on the basis of perfusate creatine phosphokinase activity and histopathologically determined injury score. RESULTS: Groups 1 and 3 hearts could be resuscitated to perform work equivalently during the entire reperfusion period and showed positive responses to increases in pre-load and norepinephrine. Group 2 hearts could not perform work. After 3 hours, Group 2 hearts showed significantly higher creatine phosphokinase and histopathologic injury scores compared to with Groups 1 and 3, which were not significantly different from each other. CONCLUSIONS: Pharmacologic pre-conditioning and controlled reperfusion effectively protect non-beating porcine hearts from injury after 30 minutes of hypoxia/ischemia in situ.


Asunto(s)
Adenosina/uso terapéutico , Antiarrítmicos/uso terapéutico , Guanidinas/uso terapéutico , Precondicionamiento Isquémico Miocárdico/métodos , Daño por Reperfusión Miocárdica/prevención & control , Sulfonas/uso terapéutico , Vasodilatadores/uso terapéutico , Animales , Creatina Quinasa/metabolismo , Corazón/efectos de los fármacos , Corazón/fisiopatología , Hipoxia/metabolismo , Daño por Reperfusión Miocárdica/enzimología , Daño por Reperfusión Miocárdica/patología , Miocardio/enzimología , Miocardio/patología , Porcinos
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...