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1.
Gynecol Oncol ; 159(3): 692-698, 2020 12.
Artículo en Inglés | MEDLINE | ID: mdl-33077258

RESUMEN

BACKGROUND: We investigated the safety and efficacy of a combination of the oral tyrosine kinase inhibitor, nintedanib (BIBF 1120) with oral cyclophosphamide in patients with relapsed ovarian cancer. PATIENTS AND METHODS: Patients with relapsed ovarian, fallopian tube or primary peritoneal cancer received oral cyclophosphamide (100 mg o.d.) and were randomised (1,1) to also have either oral nintedanib or placebo. The primary endpoint was overall survival (OS). Secondary endpoints included progression free survival (PFS), response rate, toxicity, and quality of life. RESULTS: 117 patients were randomised, 3 did not start trial treatment, median age 64 years. Forty-five (39%) had received ≥5 lines chemotherapy. 30% had received prior bevacizumab. The median OS was 6.8 (nintedanib) versus 6.4 (placebo) months (hazard ratio 1.08; 95% confidence interval 0.72-1.62; P = 0.72). The 6-month PFS rate was 29.6% versus 22.8% (P = 0.57). Grade 3/4 adverse events occurred in 64% (nintedanib) versus 54% (placebo) of patients (P = 0.28); the most frequent G3/4 toxicities were lymphopenia (18.6% nintedanib versus 16.4% placebo), diarrhoea (13.6% versus 0%), neutropenia (11.9% versus 0%), fatigue (10.2% versus 9.1%), and vomiting (10.2% versus 7.3%). Patients who had received prior bevacizumab treatment had 52 days less time on treatment (P < 0.01). 26 patients (23%) took oral cyclophosphamide for ≥6 months. There were no differences in quality of life between treatment arms. CONCLUSIONS: This is the largest reported cohort of patients with relapsed ovarian cancer treated with oral cyclophosphamide. Nintedanib did not improve outcomes when added to oral cyclophosphamide. Although not significant, more patients than expected remained on treatment for ≥6 months. This may reflect a higher proportion of patients with more indolent disease or the higher dose of cyclophosphamide used. CLINICAL TRIAL REGISTRATION: Clinicaltrials.govNCT01610869.


Asunto(s)
Protocolos de Quimioterapia Combinada Antineoplásica/efectos adversos , Ciclofosfamida/efectos adversos , Neoplasias de las Trompas Uterinas/tratamiento farmacológico , Indoles/efectos adversos , Neoplasias Ováricas/tratamiento farmacológico , Neoplasias Peritoneales/tratamiento farmacológico , Administración Metronómica , Administración Oral , Anciano , Inhibidores de la Angiogénesis/administración & dosificación , Inhibidores de la Angiogénesis/efectos adversos , Protocolos de Quimioterapia Combinada Antineoplásica/administración & dosificación , Ciclofosfamida/administración & dosificación , Neoplasias de las Trompas Uterinas/diagnóstico , Neoplasias de las Trompas Uterinas/mortalidad , Neoplasias de las Trompas Uterinas/patología , Femenino , Humanos , Indoles/administración & dosificación , Persona de Mediana Edad , Estadificación de Neoplasias , Neoplasias Ováricas/diagnóstico , Neoplasias Ováricas/mortalidad , Neoplasias Ováricas/patología , Neoplasias Peritoneales/diagnóstico , Neoplasias Peritoneales/mortalidad , Neoplasias Peritoneales/patología , Supervivencia sin Progresión , Calidad de Vida
2.
Ir Med J ; 109(4): 397, 2016 Apr 11.
Artículo en Inglés | MEDLINE | ID: mdl-27685491

RESUMEN

Ischaemic stroke clinical outcomes are improved by earlier treatment with intravenous thrombolysis. An existing pathway at the Mater University Hospital for assessment of suspected acute stroke in the Emergency Department was updated, aiming to shorten door-to-needle time. This study examines the final clinical diagnosis of Dublin Fire Brigade Ambulance Paramedic identified Face-Arm-Speech-Test (FAST) positive patients presenting to the Emergency Department over a 7 month period. A retrospective analysis was carried out of 177 consecutive FAST positive patients presenting between March and November 2014. The final clinical diagnosis was acute stroke in 57.1% (n=101) of patients. Of these, 76 were ischaemic strokes of whom 56.5% (n=43) were thrombolysed. In the pre-hospital setting Ambulance Paramedics can identify, with reasonable accuracy, acute stroke using the FAST test. Over half of the ischaemic stroke patients presenting via this pathway can be treated with intravenous thrombolysis.

3.
Ann Oncol ; 25(10): 1988-1995, 2014 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-25070546

RESUMEN

BACKGROUND: We investigated whether the Src inhibitor saracatinib (AZD0530) improved efficacy of weekly paclitaxel in platinum-resistant ovarian cancer. PATIENTS AND METHODS: Patients with platinum-resistant ovarian, fallopian tube or primary peritoneal cancer were randomised 2 : 1 to receive 8-week cycles of weekly paclitaxel (wPxl; 80 mg/m(2)/week ×6 with 2-week break) plus saracatinib (S; 175 mg o.d.) or placebo (P) continuously, starting 1 week before wPxl, until disease progression. Patients were stratified by taxane-free interval (<6 versus ≥6 months/no prior taxane). The primary end point was progression-free survival (PFS) rate at 6 months. Secondary end points included overall survival (OS) and response rate (RR). RESULTS: A total of 107 patients, median age 63 years, were randomised. Forty-three (40%) had received >2 lines of prior chemotherapy. The 6-month PFS rate was 29% (wPxl + S) versus 34% (wPxl + P) (P = 0.582). Median PFS was 4.7 versus 5.3 months (hazard ratio 1.00, 95% confidence interval 0.65-1.54; P = 0.99). RR (complete + partial) was 29% (wPxl + S) versus 43% (wPxl + P), P value = 0.158. Grade 3/4 adverse events were 36% versus 31% (P = 0.624); the most frequent G3/4 toxicities were vomiting (5.8% saracatinib versus 8.6% placebo), abdominal pain (5.8% versus 0%) and diarrhoea (4.3% versus 5.7%). Febrile neutropenia was more common in the saracatinib arm (4.3%) than placebo (0%). Response, PFS and OS were all significantly (P < 0.05) better in patients with taxane interval ≥6 months/no prior taxane (n = 85) than those <6 months (n = 22), regardless of randomisation. CONCLUSIONS: Saracatinib does not improve activity of weekly paclitaxel in platinum-resistant ovarian cancer. Taxane-free interval of ≥6 months/no prior taxane was associated with better outcome in both groups. TRIALS REGISTRATION: Clinicaltrials.gov NCT01196741; ISRCTN 32163062.


Asunto(s)
Benzodioxoles/administración & dosificación , Neoplasias de las Trompas Uterinas/tratamiento farmacológico , Neoplasias Ováricas/tratamiento farmacológico , Paclitaxel/administración & dosificación , Quinazolinas/administración & dosificación , Neoplasias Retroperitoneales/tratamiento farmacológico , Adulto , Anciano , Anciano de 80 o más Años , Protocolos de Quimioterapia Combinada Antineoplásica , Supervivencia sin Enfermedad , Resistencia a Antineoplásicos/efectos de los fármacos , Neoplasias de las Trompas Uterinas/patología , Femenino , Humanos , Persona de Mediana Edad , Neoplasias Ováricas/patología , Platino (Metal)/efectos adversos , Platino (Metal)/uso terapéutico , Neoplasias Retroperitoneales/patología
4.
Br J Cancer ; 108(12): 2464-9, 2013 Jun 25.
Artículo en Inglés | MEDLINE | ID: mdl-23695016

RESUMEN

BACKGROUND: We investigated the feasibility of dose-dense neoadjuvant chemotherapy (NACT) with paclitaxel and carboplatin before radical chemoradiation (CRT) and assessed the response rate to such a regimen. METHODS: CxII is a single-arm phase II trial of 46 patients, with locally advanced cervical cancer (stage Ib2-IVa). Patients received dose-dense carboplatin (AUC2) and paclitaxel (80 mg m⁻²) weekly for six cycles followed by CRT (40 mg m⁻² of weekly cisplatin, 50.4 Gy, 28 fractions plus brachytherapy). The primary end point was response rate 12 weeks post-CRT. RESULTS: Baseline characteristics were: median age at diagnosis 43 years; 72% squamous, 22% adenocarcinoma and 7% adenosquamous histologies; FIGO stage IB2 (11%), II (50%), III (33%), IV (7%). Complete or partial response rate was 70% (95% CI: 54-82) post-NACT and 85% (95% CI: 71-94) post-CRT. The median follow-up was 39.1 months. Overall and progression-free survivals at 3 years were 67% (95% CI: 51-79) and 68% (95% CI: 51-79), respectively. Grade 3/4 toxicities were 20% during NACT (11% haematological, 9% non-haematological) and 52% during CRT (haematological: 41%, non-haematological: 22%). CONCLUSION: A good response rate is achieved by dose-dense weekly NACT with carboplatin and paclitaxel followed by radical CRT. This treatment regimen is feasible as evidenced by the acceptable toxicity of NACT and by the high compliance to radiotherapy (98%).


Asunto(s)
Adenocarcinoma/terapia , Protocolos de Quimioterapia Combinada Antineoplásica/administración & dosificación , Carcinoma de Células Escamosas/terapia , Quimioradioterapia , Neoplasias del Cuello Uterino/terapia , Adenocarcinoma/mortalidad , Adenocarcinoma/patología , Adulto , Anciano , Protocolos de Quimioterapia Combinada Antineoplásica/efectos adversos , Carboplatino/administración & dosificación , Carboplatino/efectos adversos , Carcinoma de Células Escamosas/mortalidad , Carcinoma de Células Escamosas/patología , Terapia Combinada , Progresión de la Enfermedad , Esquema de Medicación , Femenino , Humanos , Persona de Mediana Edad , Terapia Neoadyuvante , Paclitaxel/administración & dosificación , Paclitaxel/efectos adversos , Análisis de Supervivencia , Neoplasias del Cuello Uterino/mortalidad , Neoplasias del Cuello Uterino/patología , Adulto Joven
5.
Ir J Psychol Med ; 40(2): 209-216, 2023 06.
Artículo en Inglés | MEDLINE | ID: mdl-33272341

RESUMEN

OBJECTIVES: Schizoaffective disorder and schizophrenia are common presentations to psychiatry services. Research to date has focussed on hypothesised biological differences between these two disorders. Little is known about possible variations in admission patterns. Our study compared demographic and clinical features of patients admitted voluntarily and involuntarily with diagnoses of schizoaffective disorder or schizophrenia to three psychiatry admission units in Ireland. METHODS: We studied all admissions to three acute psychiatry units in Ireland for periods between 1 January 2008 and 31 December 2018. We recorded demographic and clinical variables for all admissions. Voluntary and involuntary admissions of patients with schizoaffective disorder were compared to those with schizophrenia. RESULTS: We studied 5581 admissions to the study units for varying periods between January 2008 and December 2018, covering a total of 1 976 154 person-years across the 3 catchment areas. The 3 study areas had 218.8, 145.5 and 411.2 admissions per 100 000 person-years, respectively. Of the 5581 admissions over the study periods, schizoaffective disorder accounted for 5% (n = 260) and schizophrenia for 17% (n = 949). Admissions with schizoaffective disorder were significantly more likely to be female and older, and less likely to have involuntary admission status, compared to those with schizophrenia. As first admissions were not distinguished from re-admissions in this dataset, these findings merit further study. CONCLUSIONS: Admissions with a schizoaffective disorder differ significantly from those with schizophrenia, being, in particular, less likely to be involuntary admissions. This suggests that psychotic symptoms might be a stronger driver of involuntary psychiatry admission than affective symptoms.


Asunto(s)
Trastornos Psicóticos , Esquizofrenia , Humanos , Femenino , Masculino , Esquizofrenia/epidemiología , Internamiento Obligatorio del Enfermo Mental , Trastornos Psicóticos/epidemiología , Trastornos Psicóticos/terapia , Hospitalización , Irlanda/epidemiología
6.
Int J Prod Res ; 60(11)2022.
Artículo en Inglés | MEDLINE | ID: mdl-38868536

RESUMEN

Industry desires a digital thread of information that aligns as-designed, as-planned, as-executed, and as-inspected viewpoints. An experiment was conducted to test selected open data standards' ability to integrate the lifecycle stages of engineering design, manufacturing, and quality assurance through a thorough implementation of a small scale model-based enterprise. The research team set out to answer: from design, through production, and final inspections, what are the hurdles that a manufacturer would face during the development of a fully linked and integrated information chain? The research team was not able to fully link all the required information, but value for industry was still identified. This paper presents the results of the experiment, provides guidance on how to overcome or mitigate identified challenges, and discusses the benefits or incentives to be gained from tracing or linking information through multiple stages a product lifecycle.

7.
J Exp Med ; 174(1): 115-24, 1991 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-1711558

RESUMEN

T cell receptors (TCRs) and immunoglobulins (Igs) derive a large fraction of their repertoire from diversity generated at the junctions of the V, D, and J coding segments. This diversity is derived both from the random deletion of nucleotides from the ends of coding regions and from the subsequent addition of nontemplated N region nucleotides. While the vast majority of TCRs and Igs from adult mice have N regions, less than 5% of both TCR-gamma/delta and Ig from fetal and neonatal mice have N regions. This study analyzed the ontogeny of junctional diversity of TCR-alpha/beta. Genomic DNA or C beta-primed cDNA was prepared from thymocytes of mice at varying stages in ontogeny, and the rearranged V beta 8 or V beta 5 sequences were amplified by polymerase chain reactions. Sequencing of the V beta-D beta-J beta junctions showed few N regions early in ontogeny, although the fraction of sequences with N regions exceeded that previously reported for Ig and for TCR-gamma/delta. N regions were found in 13% of V beta junctional sequences from day 18-19 fetal thymocytes, 33% of sequences from newborn thymocytes, 76% of sequences from day 4 postnatal thymocytes, and 88% of sequences from 5-wk-old thymocytes. In addition, nonrandom usage of the D beta and J beta segments was observed in both fetal and adult TCR sequences. While the usage of each of the six J beta 2 segments was different, the same pattern of usage was seen regardless of whether D beta 1 or D beta 2 was used, suggesting that a factor controlling the rate of usage of each J segment is intrinsic to the J gene itself. Since TCRs derive so much of their diversity from N regions, the relative paucity of N regions in fetal alpha/beta T cells would create a fetal TCR-alpha/beta repertoire that would be quite different from, and smaller than, the adult repertoire. The lack of N regions might be predicted to limit the range of affinities of TCR-MHC + peptide interactions, which may have important consequences for positive and negative selection of fetal and newborn T cells.


Asunto(s)
Variación Genética , Receptores de Antígenos de Linfocitos T/genética , Animales , Animales Recién Nacidos , Secuencia de Bases , Deleción Cromosómica , ADN/genética , Feto , Genes de Inmunoglobulinas , Sustancias Macromoleculares , Ratones , Ratones Endogámicos BALB C , Datos de Secuencia Molecular , Sondas de Oligonucleótidos , Reacción en Cadena de la Polimerasa , ARN/genética , ARN/aislamiento & purificación , Linfocitos T/inmunología , Timo/inmunología
8.
J Exp Med ; 172(5): 1377-90, 1990 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-1700054

RESUMEN

Much of T and B lymphocyte receptor diversity derives from the addition of nontemplated N regions at the junctions of receptor gene elements, although fetal T cells expressing gamma/delta receptors lack N regions. I have sequenced immunoglobulin H chain variable regions of PCR-amplified DNA and cDNA from fetal and newborn mouse liver and spleen cells. These sequences showed an absence of N regions. Only 1/87 DNA sequences and 17/146 RNA sequences contained N regions, in striking contrast to adult Ig sequences. These data show that N region insertion is a developmentally regulated process in B cells as well as in T cells, and demonstrate that receptor diversity in neonatal B cells is limited by the absence of N regions as well as by biased usage of Vh genes.


Asunto(s)
Animales Recién Nacidos/inmunología , Feto/inmunología , Reordenamiento Génico/genética , Genes de Inmunoglobulinas/genética , Animales , Animales Recién Nacidos/metabolismo , Secuencia de Bases , ADN/análisis , ADN/genética , Elementos Transponibles de ADN , Feto/metabolismo , Región de Unión de la Inmunoglobulina/genética , Hígado/química , Ratones , Ratones Endogámicos BALB C , Datos de Secuencia Molecular , Reacción en Cadena de la Polimerasa , ARN/análisis , ARN/genética , Bazo/química
9.
J Exp Med ; 160(1): 329-34, 1984 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-6204002

RESUMEN

The requirements for T cell/B cell interaction for the induction of primary in vitro antibody responses to phosphorylcholine (PC)-keyhole limpet hemocyanin (KLH) were examined. Long-term helper T cell lines derived from KLH-primed (CBA/N X BALB/c) F1 female mice (H-2k/d) were able to support a T15-idiotype dominant, IgM anti-PC response of BALB/c (H-2d) B cells and macrophages, but could not activate PC-specific responses by BALB.B (H-2b) B cells, even in the presence of irradiated H-2k/d antigen-presenting cells. Polyclonal IgM secretion in the same cultures did not appear to depend upon a major histocompatibility complex (MHC)-restricted T-B interaction. Since IgM anti-PC responses seem to be entirely derived from the Lyb5+ B cell subpopulation, we conclude that at least some Lyb5+ B cells can only be activated by MHC-restricted T-B interactions. We also found that xid B cells from (CBA/N X BALB/c) F1 male mice could be polyclonally activated by helper T cell lines by an apparently MHC-unrestricted interaction. Our data thus suggests that residence in the Lyb5- or Lyb5+ B cell subset does not determine the T:B interaction requirements for antibody synthesis.


Asunto(s)
Antígenos Ly/inmunología , Linfocitos B/inmunología , Colina/análogos & derivados , Cooperación Linfocítica , Fosforilcolina/inmunología , Linfocitos T Colaboradores-Inductores/inmunología , Animales , Linfocitos B/clasificación , Epítopos , Femenino , Antígenos H-2/genética , Hemocianinas/inmunología , Inmunoglobulina M/biosíntesis , Masculino , Ratones , Ratones Endogámicos BALB C
10.
J Exp Med ; 187(9): 1495-503, 1998 May 04.
Artículo en Inglés | MEDLINE | ID: mdl-9565641

RESUMEN

Functional variable (V), diversity (D), and joining (J) gene segments contribute unequally to the primary repertoire. One factor contributing to this nonrandom usage is the relative frequency with which the different gene segments rearrange. Variation from the consensus sequence in the heptamer and nonamer of the recombination signal sequence (RSS) is therefore considered a major factor affecting the relative representation of gene segments in the primary repertoire. In this study, we show that the sequence of the spacer is also a determinant factor contributing to the frequency of rearrangement. Moreover, the effect of the spacer on recombination rates of various human Vkappa gene segments in vitro correlates with their frequency of rearrangement in vivo in pre-B cells and with their representation in the peripheral repertoire.


Asunto(s)
Linfocitos B/fisiología , Reordenamiento Génico/genética , Genes de Inmunoglobulinas/genética , Recombinación Genética/genética , Secuencia de Bases , Humanos , Región Variable de Inmunoglobulina , Cadenas kappa de Inmunoglobulina/genética , Datos de Secuencia Molecular , Reacción en Cadena de la Polimerasa , Señales de Clasificación de Proteína/genética , Receptores de Antígenos de Linfocitos T/genética
11.
J Exp Med ; 194(5): 645-56, 2001 Sep 03.
Artículo en Inglés | MEDLINE | ID: mdl-11535632

RESUMEN

Accessibility of immunoglobulin (Ig) gene segments to V(D)J recombination is highly regulated and is normally only achieved in B cell precursors. We previously showed that ectopic expression of E2A or early B cell factor (EBF) with recombination activating gene (RAG) induces rearrangement of IgH and IgL genes in nonlymphoid cells. VkappaI genes throughout the locus were induced to rearrange after transfection with E2A, suggesting that the entire Vkappa locus was accessible. However, here we show that Ig loci are not opened globally but that recombination is localized. Gene families are interspersed in the D(H), Vkappa, and Vlambda loci, and we show that certain families and individual genes undergo high levels of recombination after ectopic expression of E2A or EBF, while other families within the same locus are not induced to rearrange. Furthermore, in some families, induction of germline transcription correlates with the level of induced recombination, while in others there is no correlation, suggesting that recombination is not simply initiated by induction of germline transcription. The induced repertoire seen at 24 hours does not change significantly over time indicating the absence of many secondary rearrangements and also suggesting a direct targeting mechanism. We propose that accessibility occurs in a local manner, and that binding sites for factors facilitating accessibility are therefore likely to be associated with individual gene segments.


Asunto(s)
Genes de Inmunoglobulinas , Genes RAG-1 , Región Variable de Inmunoglobulina/genética , Cadenas kappa de Inmunoglobulina/genética , Familia de Multigenes , Recombinación Genética , Factores de Transcripción/metabolismo , Animales , Linfocitos B/inmunología , Factores de Transcripción con Motivo Hélice-Asa-Hélice Básico , Línea Celular , ADN Nucleotidiltransferasas/metabolismo , Proteínas de Unión al ADN/metabolismo , Reordenamiento Génico , Proteínas de Homeodominio/genética , Proteínas de Homeodominio/metabolismo , Humanos , Reacción en Cadena de la Polimerasa , Proteínas Recombinantes/metabolismo , Transactivadores/metabolismo , Transcripción Genética , Transfección , VDJ Recombinasas
12.
Ir J Psychol Med ; 36(3): 187-193, 2019 09.
Artículo en Inglés | MEDLINE | ID: mdl-30854993

RESUMEN

OBJECTIVES: The transition from adolescent to adult mental health services (AMHS) is associated with disengagement, poor continuity of care and patient dissatisfaction. The aim of this retrospective and descriptive study was to describe the 'care pathways' in an independent mental health service when adolescents reach age 18 and to investigate the level of engagement of those who transitioned to independent AMHS. METHODS: This is a retrospective, naturalistic and descriptive study in design. All patients discharged from the St Patrick's Adolescent Mental Health Service aged 17 years and 6 months and older, during a 3-year period between January 2014 and December 2016, were included. Electronic records were used to collect socio-demographic and clinical details and to determine engagement rates in adolescents who transferred to independent adult services. RESULTS: A total of 180 patients aged over 17 years and 6 months were discharged from the adolescent service. Of these, 45.6% were discharged to their GP, 28.9% to public mental health services and 25.6% to independent mental health services. The majority who transitioned to independent AMHS went to a Young Adult Service, which had high engagement rates at 3 and 12 months post-transition. CONCLUSIONS: In this independent mental health service, less than half of adolescents who reach the transition age are referred onto AMHS. Engagement rates were found to be high among those referred on to a specialised young adult service.


Asunto(s)
Servicios de Salud del Adolescente/estadística & datos numéricos , Servicios de Salud Mental/estadística & datos numéricos , Transición a la Atención de Adultos , Adolescente , Adulto , Femenino , Humanos , Irlanda , Masculino , Trastornos Mentales/psicología , Trastornos Mentales/terapia , Alta del Paciente , Estudios Retrospectivos , Adulto Joven
14.
J Clin Invest ; 97(10): 2277-82, 1996 May 15.
Artículo en Inglés | MEDLINE | ID: mdl-8636407

RESUMEN

The antibody response to H. influenzae type b (Hib) is pauciclonal, and is dominated by antibodies using the VkappaA2 gene. Navajos have a 5-10-fold increased incidence of Hib disease compared with control populations. We hypothesized that a polymorphism in one of the genes in this oligoclonal response may lead to increased disease susceptibility. Since the predominant A2+ anti-Hib antibodies have high avidity for Hib and can be unmutated, the A2 Vkappa gene was analyzed. Over half of the Navajos studied, but only one control individual, had a new allele of A2, termed A2b, with three changes from the published A2 germline sequence. One of the changes was in the recombination signal sequence, suggesting that the A2b allele might not undergo V-J rearrangement very frequently. This possibility was confirmed by analyzing the relative frequency of non-productive A2 rearrangements in A2a/b heterozygous Navajos. Many fewer A2b rearrangements were observed, showing that the A2b allele is defective in its ability to undergo rearrangement. The prevalence of this allele in Navajos may play a role in their increased susceptibility to invasive Hib disease. If so, it would underscore the importance of the germline Ig repertoire for protective antibody responses to pathogenic bacteria in unimmunized children.


Asunto(s)
Anticuerpos Antibacterianos/genética , Genes de Inmunoglobulinas , Infecciones por Haemophilus/etiología , Haemophilus influenzae/inmunología , Región Variable de Inmunoglobulina/genética , Cadenas kappa de Inmunoglobulina/genética , Inuk/genética , Alelos , Secuencia de Aminoácidos , Secuencia de Bases , Reordenamiento Génico , Humanos , Datos de Secuencia Molecular , Regiones Promotoras Genéticas
15.
Mol Cell Biol ; 17(7): 3768-78, 1997 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-9199310

RESUMEN

During V(D)J recombination, the coding ends to be joined are extensively modified. Those modifications, termed coding-end processing, consist of removal and addition of various numbers of nucleotides. We previously showed in vivo that coding-end processing is specific for each coding end, suggesting that specific motifs in a coding-end sequence influence nucleotide deletion and P-region formation. In this study, we created a panel of recombination substrates containing actual immunoglobulin and T-cell receptor coding-end sequences and dissected the role of each motif by comparing its processing pattern with those of variants containing minimal nucleotide changes from the original sequence. Our results demonstrate the determinant role of specific sequence motifs on coding-end processing and also the importance of the context in which they are found. We show that minimal nucleotide changes in key positions of a coding-end sequence can result in dramatic changes in the processing pattern. We propose that each coding-end sequence dictates a unique hairpin structure, the result of a particular energy conformation between nucleotides organizing the loop and the stem, and that the interplay between this structure and specific sequence motifs influences the frequency and location of nicks which open the coding-end hairpin. These findings indicate that the sequences of the coding ends determine their own processing and have a profound impact on the development of the primary B- and T-cell repertoires.


Asunto(s)
Reordenamiento Génico de Linfocito B , Genes de Inmunoglobulinas , Animales , Composición de Base , Secuencia de Bases , Células Cultivadas , Codón , ADN/metabolismo , Enlace de Hidrógeno , Ratones , Conformación de Ácido Nucleico , Recombinación Genética , Eliminación de Secuencia , Relación Estructura-Actividad
16.
Psychopharmacology (Berl) ; 180(4): 595-606, 2005 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-15864554

RESUMEN

RATIONALE: Gamma-aminobutyric acid (GABA)-benzodiazepine receptor function is hypothesised to be reduced in alcohol dependence. OBJECTIVES: We used positron emission tomography (PET) with [11C]flumazenil, a non-selective tracer for brain GABA-benzodiazepine (GABA-BDZ) receptor binding, to determine in vivo the relationship between BDZ receptor occupancy by an agonist, midazolam, and its functional effects. METHODS: Abstinent male alcohol dependent subjects underwent [11C]flumazenil PET to measure occupancy of BDZ receptors by midazolam whilst recording its pharmacodynamic effects on behavioural and physiological measures. Rate constants describing the exchange of [11C]flumazenil between the plasma and brain compartments were derived from time activity curves. RESULTS: A 50% reduction in electroencephalography (EEG)-measured sleep time was seen in the alcohol dependent group despite the same degree of occupancy by midazolam as seen in the control group. The effects of midazolam on other measures of benzodiazepine receptor function, increasing EEG beta1 power and slowing of saccadic eye movements, were similar in the two groups. No differences in midazolam or flumazenil metabolism were found between the groups. CONCLUSIONS: In summary, our study suggests that alcohol dependence in man is associated with a reduced EEG sleep response to the benzodiazepine agonist, midazolam, which is not explained by reduced BDZ receptor occupancy, and is consistent with reduced sensitivity in this measure of GABA-BDZ receptor function in alcohol dependence. The lack of change in other functional measures may reflect a differential involvement of particular subtypes of the GABA-BDZ receptor.


Asunto(s)
Alcoholismo/metabolismo , Encéfalo/fisiopatología , Flumazenil/farmacocinética , Moduladores del GABA/farmacocinética , Tomografía de Emisión de Positrones , Receptores de GABA-A/fisiología , Adulto , Análisis de Varianza , Presión Sanguínea/efectos de los fármacos , Encéfalo/efectos de los fármacos , Estudios de Casos y Controles , Propuestas de Licitación/métodos , Electroencefalografía/métodos , Moduladores del GABA/sangre , Frecuencia Cardíaca/efectos de los fármacos , Humanos , Procesamiento de Imagen Asistido por Computador/métodos , Masculino , Midazolam/sangre , Midazolam/farmacología , Persona de Mediana Edad , Dimensión del Dolor/métodos , Movimientos Sacádicos/efectos de los fármacos , Índice de Severidad de la Enfermedad , Sueño/efectos de los fármacos , Escala de Ansiedad ante Pruebas/estadística & datos numéricos , Factores de Tiempo , Tritio/farmacocinética
17.
Mol Immunol ; 30(16): 1473-9, 1993 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-8232333

RESUMEN

In the neonate, Ig V-D-J junctions often occur at regions of short sequence homology, resulting in one to two predominant junctional sequences for most V-D and D-J recombinations. We have proposed that this mechanism of homology-directed recombination may play a role in the non-random usage of VH genes observed in fetal and neonatal life, since use of the short homologies at V-D junctions would preferentially make productive rearrangements for the overutilized 7183 and Q52 VH genes, and would make predominantly non-productive rearrangements for the underutilized VHJ558 gene family. Here we test this hypothesis for the 81X gene from the VH7183 family. Since pre-B cells which have rearranged the 81X gene do not appear to undergo the normal clonal proliferation before light chain rearrangement, analysis of the percentage of productive versus non-productive rearrangements for this VH gene is not skewed by the expansion of pre-B cells with productively rearranged IgH alleles. If V-D-J rearrangements were random, one would predict that only one-third of the rearrangements would be in-frame. This is close to what we observed for the 81X gene in adult bone marrow. In contrast, we show that 62% of all 81X rearrangements in fetal/newborn pre-B cells were productive. Forty-one percent of all the neonatal pre-B sequences containing DFL16 or DSP2 used homology-directed recombination to create the predominantly observed V-D junctional sequences, and 93% of those sequences were productive. This is consistent with our hypothesis that the mechanism of homology-directed recombination would result in an increased proportion of productive 81X rearrangements in the newborn. Therefore, we suggest that in fetal and neonatal life, when N regions are lacking, VH7183 and VHQ52 genes are more likely to undergo productive rearrangements than other VH families and thus are much more likely to contribute to the early B cell repertoire.


Asunto(s)
Reordenamiento Génico , Genes de Inmunoglobulinas , Cadenas Pesadas de Inmunoglobulina/genética , Región Variable de Inmunoglobulina/genética , Adulto , Diversidad de Anticuerpos , Linfocitos B/ultraestructura , Secuencia de Bases , Células Madre Hematopoyéticas/ultraestructura , Humanos , Recién Nacido , Hígado/inmunología , Datos de Secuencia Molecular , Recombinación Genética
18.
Mol Immunol ; 35(4): 227-32, 1998 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-9736338

RESUMEN

Receptor editing is a process consisting of replacement of pre-existing H or L chain rearrangements by secondary rearrangements. This process could serve to remove autoreactive specificities, or to rescue loci with non-functional rearrangements. At the H chain locus, functional replacement of a V(H)DJ(H) rearrangement by an upstream V(H) requires the presence of an embedded RSS located in reverse orientation near the 3' end of the V(H) segment. Although most V(H) genes contain a fairly consensus embedded heptamer, the nonamer sequence bears little resemblance to the consensus RSS nonamer. Therefore, the physiologic rate of H chain editing by V(H) replacement is yet unknown. In this study, we used both conventional and sensitive competition recombination substrate assays to determine the recombination frequency of the V(H)1X embedded RSS relative to consensus and non-consensus RSS's. Results show no detectable recombination of the 81X embedded RSS in a recombination substrate, and the competition substrate allows us to estimate that the 81X embedded RSS recombines at least 1300 fold less often than a consensus RSS. This suggests that V(H) gene replacement is not responsible for the decrease in representation of the 81X gene during differentiation. Furthermore, since the sequence of the embedded RSS is very similar for many V(H) genes, our results suggest that receptor editing of the H chain will be an infrequent event, leaving L chain editing as the main mode of avoiding autoreactive specificities in vivo.


Asunto(s)
Reordenamiento Génico de Cadena Pesada de Linfocito B/genética , Región Variable de Inmunoglobulina/genética , Señales de Clasificación de Proteína/genética , Recombinación Genética/genética , Cadenas kappa de Inmunoglobulina/genética , Edición de ARN
19.
Mol Immunol ; 31(11): 783-91, 1994 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-8047070

RESUMEN

The scid mutation interferes with normal rearrangement of antigen receptor genes, leading to an absence of T and B lymphocytes in most SCID mice. However, the SCID phenotype is "leaky", with an age- and strain-dependent increase in the incidence of mice with small number of T and B cells and readily detectable serum immunoglobulin. Introduction of neonatal T cells into young SCID mice results in a 100% incidence of the leaky phenotype. We have identified the location of antibody secreting cells in T cell-induced leaky SCID mice as the spleen and peritoneal cavity, and we have sequenced 35 productively rearranged immunoglobulin genes from these sites to determine if normal V-D-J recombination was occurring. VH11 sequences with potential autoreactivity were observed frequently in both the peritoneal cavity and spleen of T cell-induced leaky SCID mice, and these sequences were indistinguishable from those recovered from peritoneal cavity B cells from normal C.B-17 mice. Non-VH11 SCID sequences showed fewer N nucleotides and slightly more P nucleotides than normal V-D-J sequences. Many SCID junctions occurred at the site of short sequence homologies. These results suggest that successful V-D-J recombination is occurring with low frequency in all SCID mice, and that neonatal T cell transfer plus autoantigen stimulation allows the long term survival of these B cells.


Asunto(s)
Reordenamiento Génico de Cadena Pesada de Linfocito B/inmunología , Animales , Células Productoras de Anticuerpos , Secuencia de Bases , Ensayo de Inmunoadsorción Enzimática , Región Variable de Inmunoglobulina/genética , Ratones , Ratones Endogámicos BALB C , Ratones SCID , Datos de Secuencia Molecular , Mutación , Reacción en Cadena de la Polimerasa , Linfocitos T/trasplante
20.
Mol Immunol ; 37(1-2): 29-39, 2000.
Artículo en Inglés | MEDLINE | ID: mdl-10781833

RESUMEN

The process of V(D)J recombination is highly regulated. Germline transcription of unrearranged gene segments precedes V(D)J rearrangement, and the correlation between germline transcription and accessibility for recombination is strong; thus it has been suggested that germline transcription may be required for rearrangement. If germline transcription is essential for rearrangement, then the level of transcription of individual gene segments might affect the relative frequency of recombination of those genes. Also, since the intronic enhancer, E(mu), is very distant from V(H) genes before they rearrange, then any promoters which were enhancer dependent might have a transcriptional advantage. Here we study in luciferase vectors the promoters of three functional genes of the V(H)S107 family, and compare them to that of the most frequently rearranging gene in the mouse I(g)H locus, V(H)81X, and to a V(H)J558 gene. Within the V(H)S107 family, the three V(H) genes rearrange with very different relative frequencies, with V1 rearranging the most, and V13 seldom rearranging. We show that only the strong V(H)J558 promoter has significant luciferase reporter gene activity in the absence of E(mu). V1 has only 20% as much activity as J558 in the absence of E(mu), and the other promoters have less than 8% of the activity of J558. Notably, the 81X promoter has essentially no enhancer-independent activity. In the presence of E(mu), V1 has equivalent activity to J558, while the other promoters show much less activity. Again, 81X is the weakest promoter of all, despite being the most frequently rearranging gene. Finally, we show that the steady state level of V(H)S107 and V(H)7183 germline transcripts in vivo is very low. Thus, these data show little correlation between the strength or enhancer-independence of these V(H) promoters and the relative frequency of recombination of the corresponding V(H) genes. In addition, the data show that individual V(H) promoters have different strengths even in the presence of E(mu), demonstrating that even promoters within a single V(H) family can be quite heterogeneous.


Asunto(s)
Elementos de Facilitación Genéticos , Reordenamiento Génico , Genes de Inmunoglobulinas , Cadenas Pesadas de Inmunoglobulina/genética , Región Variable de Inmunoglobulina/genética , Regiones Promotoras Genéticas , Animales , Secuencia de Bases , Luciferasas/genética , Ratones , Ratones Endogámicos BALB C , Datos de Secuencia Molecular , TATA Box
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