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1.
Bone Marrow Transplant ; 52(6): 825-831, 2017 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-28218757

RESUMO

We report outcomes for 44 children who underwent stem cell transplantation (SCT) for refractory AML in the UK between 2000 and 2012. Median age at SCT was 11.5 years. Twenty-three patients had primary refractory and 21 relapsed refractory AML. Refractory disease was confirmed by cytogenetics/molecular genetics in 24 cases. Median follow-up of the whole cohort is 6.8 years (2.1-14.9 years). Thirty patients (68%) achieved a CR following SCT. Transplant-related mortality at 1 year was 18%. Acute GVHD incidence was 52% (grade ⩾III 19%), chronic 7%. Relapse was the major cause of treatment failure and occurred in 32% of patients at a median of 61 days post SCT. Five-year overall survival and leukemia-free survival (LFS) were 43% (95% CI 31-61%). All patients with favorable cytogenetics (n=6) are alive in CR. Outcomes in patients with primary refractory disease were equivalent to those with relapsed refractory AML. Blast percentage ⩽30% in the BM pre-SCT, myeloablative conditioning and acute GVHD proved to be favorable prognostic features. We could stratify patients according to age ⩾10 years and >30% blasts in BM pre-SCT. Patients with none/one of these risk factors were highly salvageable (5 years LFS 53%) whereas those with both factors had a very poor prognosis (5 years LFS 10%). This may facilitate decision making on whether it is appropriate to consider transplant in such patients.


Assuntos
Doença Enxerto-Hospedeiro/mortalidade , Transplante de Células-Tronco Hematopoéticas , Leucemia Mieloide Aguda/mortalidade , Leucemia Mieloide Aguda/terapia , Doença Aguda , Adolescente , Aloenxertos , Criança , Pré-Escolar , Aberrações Cromossômicas , Intervalo Livre de Doença , Feminino , Seguimentos , Doença Enxerto-Hospedeiro/genética , Doença Enxerto-Hospedeiro/patologia , Humanos , Leucemia Mieloide Aguda/genética , Leucemia Mieloide Aguda/patologia , Masculino , Recidiva , Taxa de Sobrevida , Reino Unido/epidemiologia
2.
Bone Marrow Transplant ; 52(5): 717-725, 2017 May.
Artigo em Inglês | MEDLINE | ID: mdl-28092349

RESUMO

Improving haematopoietic cell transplantation outcomes by selection of an HLA-matched unrelated donor is best practice; however, donor selection by secondary characteristics is controversial. We studied 1271 recipients with haematological malignancies who underwent T-cell-depleted allografts and had complete data on HLA-matching status for six loci (HLA-A, -B, -C, -DRB1, -DQB1, -DPB1) and clinical outcome data. Five-year overall survival was 40.6%. HLA mismatching (at HLA-A, -B, -C, -DRB1, -DQB1) relative risk (RR) 1.22, 95% confidence interval (CI) 1.2-1.5, P=0.033 for 1 mismatch and RR 1.46, 95% CI 1.1-1.9, P=0.009 for >1 mismatch) and CMV mismatching (RR 1.37, 95% CI 1.2-1.6, P<0.001) were significantly associated with inferior survival. Donors aged <30 years showed a trend towards better survival. The multivariate model for mortality, combining CMV and HLA-match status, found an RR of 1.36 (95% CI 1.1-1.7, P=0.003) for HLA matched/CMV mismatched, an RR of 1.22 (95% CI 0.99-1.5, P=0.062) for HLA mismatched/CMV matched and an RR of 1.81 (95% CI 1.4-2.3, P=<0.001) for HLA/ CMV mismatched, compared with the HLA/CMV-matched recipients. These data suggest that HLA and CMV matching status should be considered when selecting unrelated donors and that CMV matching may abrogate the effect of an HLA mismatch.


Assuntos
Citomegalovirus/imunologia , Antígenos HLA/imunologia , Neoplasias Hematológicas/terapia , Transplante de Células-Tronco Hematopoéticas/métodos , Doadores não Relacionados/provisão & distribuição , Adolescente , Adulto , Idoso , Criança , Pré-Escolar , Feminino , Histocompatibilidade , Humanos , Depleção Linfocítica , Masculino , Pessoa de Meia-Idade , Fatores de Risco , Testes Sorológicos , Análise de Sobrevida , Adulto Jovem
4.
Bone Marrow Transplant ; 50(1): 82-6, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25285801

RESUMO

The advent of reduced intensity conditioning (RIC) regimens has permitted the extension of allo-SCT to selected patients into their eighth decade but GVHD remains a major cause of morbidity and mortality. Alemtuzumab is increasingly used to reduce the risk of severe GVHD, but there are concerns that T-cell depletion may compromise outcome particularly in older patients. We therefore studied the impact of pre-transplant factors on the outcome of 187 patients with a haematological malignancy over the age of 60 transplanted using an alemtuzumab-based RIC regimen of whom co-morbidity scoring was possible in 169. Of the patients, 120 had a haematopoietic cell transplantation co-morbidity index (HCT-CI) of 0 or 1 and 49 had a score of 2 or more. The 5-year OS was 33%. In multivariable analysis, OS was determined by co-morbidity score (P=0.001) and disease status at transplant (P=0.004) but not by patient age. Non-relapse mortality was determined by co-morbidity score (P=0.001). Two-year OS for patients with a HCT-CI of 0-1 was 59 versus 6% for patients with a higher score. Alemtuzumab-based RIC allografts can be delivered safely in patients aged over 60 but co-morbidity scoring is mandatory to identify patients who will benefit.


Assuntos
Anticorpos Monoclonais Humanizados/administração & dosagem , Antineoplásicos/administração & dosagem , Neoplasias Hematológicas , Transplante de Células-Tronco Hematopoéticas , Depleção Linfocítica , Condicionamento Pré-Transplante , Idoso , Alemtuzumab , Aloenxertos , Feminino , Neoplasias Hematológicas/mortalidade , Neoplasias Hematológicas/terapia , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Sociedades Médicas , Taxa de Sobrevida , Reino Unido
6.
Bone Marrow Transplant ; 49(1): 42-8, 2014 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-23912664

RESUMO

This retrospective national study compared the use of alemtuzumab-based conditioning regimens for hematopoietic SCT (HSCT) in acquired severe aplastic anemia with antithymocyte globulin (ATG)-based regimens. One hundred patients received alemtuzumab and 55 ATG-based regimens. A matched sibling donor (MSD) was used in 87 (56%), matched unrelated donor (MUD) in 60 (39%) and other related or mismatched unrelated donor (UD) in 8 (5%) patients. Engraftment failure occurred in 9% of the alemtuzumab group and 11% of the ATG group. Five-year OS was 90% for the alemtuzumab and 79% for the ATG groups, P=0.11. For UD HSCT, OS of patients was better when using alemtuzumab (88%) compared with ATG (57%), P=0.026, although smaller numbers of patients received ATG. Similar outcomes for MSD HSCT using alemtuzumab or ATG were seen (91% vs 85%, respectively, P=0.562). A lower risk of chronic GVHD (cGVHD) was observed in the alemtuzumab group (11% vs 26%, P=0.031). On multivariate analysis, use of BM as stem cell source was associated with better OS and EFS, and less acute and cGVHD; young age was associated with better EFS and lower risk of graft failure. This large study confirms successful avoidance of irradiation in the conditioning regimens for MUD HSCT patients.


Assuntos
Anemia Aplástica/terapia , Anticorpos Monoclonais Humanizados/uso terapêutico , Soro Antilinfocitário/uso terapêutico , Transplante de Medula Óssea/métodos , Transplante de Células-Tronco de Sangue Periférico/métodos , Condicionamento Pré-Transplante/métodos , Adolescente , Adulto , Idoso , Alemtuzumab , Células da Medula Óssea/citologia , Criança , Pré-Escolar , Feminino , Sobrevivência de Enxerto , Doença Enxerto-Hospedeiro , Humanos , Lactente , Masculino , Pessoa de Meia-Idade , Sistema de Registros , Estudos Retrospectivos , Fatores de Risco , Irmãos , Doadores de Tecidos , Resultado do Tratamento , Reino Unido , Adulto Jovem
7.
Bone Marrow Transplant ; 48(7): 982-7, 2013 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-23318533

RESUMO

Myeloablative allo-SCT decreases relapse incidence (RI) in ALL. Reduced intensity conditioning (RIC) may extend allo-SCT to older and less fit patients. Sixty-nine ALL patients reported to the BSBMT underwent fludarabine-based RIC allo-SCT, 38 from unrelated donors (UD). Forty-four patients received alemtuzumab. ALL was in CR in 64 patients (93%). This was a second or third SCT in 23 patients. Two-year OS and PFS were 36% and 32%, respectively. In multivariate analysis male recipients demonstrated better OS and PFS (hazard ratio (HR) = 0.42, P = 0.008 and HR = 0.45, P = 0.012, respectively). Two-year TRM was 29%: higher with younger age (HR = 0.97/year, P = 0.041), female recipient (HR = 2.55, P = 0.049) and increasing grade of acute GVHD (HR = 1.87, P = 0.001). Two-year RI was 38% and was lower in patients with acute and chronic GVHD (HR = 0.62 per increasing grade, P = 0.035 and HR = 0.52, P = 0.025, respectively). Long-term ALL-free survival is achievable following fludarabine-based RIC allo-SCT. The association between GVHD and decreased RI suggests the presence of a GVL effect.


Assuntos
Efeito Enxerto vs Leucemia , Leucemia-Linfoma Linfoblástico de Células Precursoras/terapia , Transplante de Células-Tronco , Condicionamento Pré-Transplante , Doença Aguda , Adolescente , Adulto , Fatores Etários , Alemtuzumab , Aloenxertos , Anticorpos Monoclonais Humanizados/administração & dosagem , Antineoplásicos/administração & dosagem , Intervalo Livre de Doença , Feminino , Doença Enxerto-Hospedeiro/etiologia , Doença Enxerto-Hospedeiro/mortalidade , Doença Enxerto-Hospedeiro/terapia , Humanos , Masculino , Pessoa de Meia-Idade , Leucemia-Linfoma Linfoblástico de Células Precursoras/mortalidade , Fatores Sexuais , Sociedades Médicas , Taxa de Sobrevida , Reino Unido , Vidarabina/administração & dosagem , Vidarabina/análogos & derivados
8.
Bone Marrow Transplant ; 47(1): 88-94, 2012 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-21358686

RESUMO

The clinical course of 2009 H1N1 influenza in Allo-SCT patients is unknown. Data were collected in the UK from October 2009 to April 2010 on laboratory-confirmed cases of H1N1 influenza in Allo-SCT recipients. H1N1 infection was diagnosed in 60 patients, median age 42 years, at a median of 10 months post-SCT. Twenty-one patients (35%) developed pneumonia and nine (15%) required admission to intensive care units. Actuarial mortality was 7% at 28 days and 19% 4 months post-diagnosis of 2009 H1N1 influenza. Increasing age and pre-existing lung disease were risk factors for pneumonia (P=0.006 and 0.037, respectively); older age was a risk factor for death (P=0.012). Morbidity and mortality from 2009 H1N1 influenza in SCT patients exceeds that of immunocompetent patients, but parallels that in other critically ill hospitalised cohorts; the elderly and those with chronic pulmonary disease are at greatest risk.


Assuntos
Vírus da Influenza A Subtipo H1N1 , Influenza Humana/mortalidade , Pandemias , Pneumonia/mortalidade , Transplante de Células-Tronco , Adolescente , Adulto , Fatores Etários , Idoso , Transplante de Medula Óssea , Criança , Pré-Escolar , Estudos de Coortes , Cuidados Críticos , Intervalo Livre de Doença , Feminino , Humanos , Lactente , Influenza Humana/terapia , Masculino , Pessoa de Meia-Idade , Pneumonia/terapia , Sociedades Médicas , Taxa de Sobrevida , Fatores de Tempo , Transplante Homólogo , Reino Unido/epidemiologia
9.
Bone Marrow Transplant ; 46(9): 1210-8, 2011 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-21102497

RESUMO

Auto-SCT is the standard first-line consolidative therapy in patients with multiple myeloma (MM). We performed a national benchmarking outcome analysis for patients with MM who underwent a single auto-SCT in 1999 and 2005. They were identified from the British Society of Blood and Marrow Transplantation (BSBMT) (n=211 and n=453) and EBMT (n=1311 and n=1978) registries. An improvement in Day+100 and D+365 non-relapsed mortality (NRM) was shown between years 1999 and 2005 (P=0.0495). The 4-year relapse rate (RR) was significantly higher in 2005 (P=0.0003) and was associated with a shorter time to next treatment (TTNT) (P=0.025). The 4-year PFS was significantly lower in 2005 (P=0.0012), with the year of auto-SCT (P=0.001) and status at auto-SCT (P=0.02) being independently significant. The 4-year OS was similar between the year cohorts (P=0.266). In the 'benchmarking' comparison, the European Group for Blood and Marrow Transplantation (EBMT) 1999 cohort demonstrated the best PFS, although no year-of-transplant effect could be demonstrated on the 4-year OS rates (P=0.760). An improvement in supportive care resulting in reduced NRM is evident between the decades. The main cause of treatment failure remains disease progression. The similarity in OS between the years may reflect the introduction of novel agents in salvage therapy. The reduced PFS in 2005 is as yet not fully explained, but may represent recent disease response criterion standardization.


Assuntos
Transplante de Células-Tronco Hematopoéticas/métodos , Mieloma Múltiplo/tratamento farmacológico , Mieloma Múltiplo/cirurgia , Adulto , Idoso , Terapia Combinada , Europa (Continente) , Feminino , Humanos , Irlanda , Masculino , Pessoa de Meia-Idade , Resultado do Tratamento , Reino Unido
10.
Bone Marrow Transplant ; 45(11): 1587-93, 2010 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-20154739

RESUMO

Fifty-one patients with primary myelofibrosis (PMF) received allogeneic haematopoietic stem cell transplants from related (n=33) or unrelated (n=18) donors. Twenty-seven patients, 19-54 years old, were prepared with myeloablative regimens including CY plus BU (n=4) or TBI (n=23). Twenty-four patients, 40-64 years old, received reduced-intensity conditioning (RIC) regimens. All RIC regimens contained fludarabine, combined with melphalan (n=19) or BU (n=5), and alemtuzumab or anti-thymocyte globulin (ATG) in the majority (n=19). Four patients (17%) in the RIC group had primary graft failure. Previous splenectomy reduced time to engraftment in the RIC group (13 versus 20 days; P=0.008). For MA and RIC groups, respectively, at 3 years, overall survival rates were 44 and 31% (P=0.67), progression-free survival 44 and 24% (P=0.87), and actuarial relapse rates 15 and 46% (P=0.06). Non-relapse mortality at 3 years was 41% for the myeloablative and 32% for the RIC group. Acute GVHD occurred in 29 and 38% of patients in the myeloablative and RIC groups, respectively. Extensive chronic GVHD developed in 30 and 35% of evaluable patients, respectively.


Assuntos
Transplante de Células-Tronco de Sangue Periférico/métodos , Mielofibrose Primária/cirurgia , Adulto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Condicionamento Pré-Transplante , Transplante Homólogo , Adulto Jovem
11.
Qual Saf Health Care ; 18(2): 93-8, 2009 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-19342521

RESUMO

This paper first describes efforts to improve the care for patients hospitalised with community-acquired pneumonia and the associated changes in quality measures at a rural academic medical centre. The results of the improvement interventions and the associated clinical realities, expected outcomes, measures, improvement interventions and improvement aims are then re-examined using the Glouberman and Zimmerman typology of healthcare problems--simple, complicated and complex. The typology is then used to explore the future design and assessment of improvement interventions, which may allow better matching with the types of problem healthcare providers and organisations are confronted with. Matching improvement interventions with problem category has the possibility of improving the success of improvement efforts and the reliability of care while at the same time preserving needed provider autonomy and judgement to adapt care for more complex problems.


Assuntos
Antibacterianos/administração & dosagem , Pneumonia/terapia , Garantia da Qualidade dos Cuidados de Saúde/métodos , Centros Médicos Acadêmicos , Lista de Checagem , Infecções Comunitárias Adquiridas/diagnóstico , Infecções Comunitárias Adquiridas/terapia , Esquema de Medicação , Implementação de Plano de Saúde , Hospitalização , Humanos , New Hampshire , Pneumonia/diagnóstico , Indicadores de Qualidade em Assistência à Saúde , Fatores de Risco
12.
J Hosp Infect ; 69(1): 39-45, 2008 May.
Artigo em Inglês | MEDLINE | ID: mdl-18353493

RESUMO

Staphylococcus aureus (SA) is becoming increasingly resistant to antibiotics in hospitals and the community. Long-term outcomes following susceptible and resistant SA infection have not been studied. We performed a retrospective matched pair analysis of all patients with positive culture for meticillin-resistant SA (MRSA) or meticillin-susceptible SA (MSSA) from any site to assess the outcomes of infection. Data were collected for length of hospitalisation and in-hospital mortality, as well as longer-term outcomes including all-cause mortality, number of rehospitalisations and subsequent cultures for SA during the year following infection. Twelve months after their initial SA infection, 42% of patients were dead. There were no differences between the groups in short-term mortality, length of hospitalisation, number of subsequent hospitalisations and cultures for SA during the year following infection. Following discharge, however, MRSA infection was associated with higher mortality than MSSA at three months (32% vs 18% P=0.02), six months (42% vs 22% P=0.002) and 12 months (51% vs 32% P=0.005). In conclusion, SA infection is associated with a high one-year all-cause mortality. Most deaths occur after discharge. The likelihood of dying during the year following infection is higher for patients with MRSA infection than for those with MSSA infection.


Assuntos
Mortalidade Hospitalar , Tempo de Internação , Resistência a Meticilina , Infecções Estafilocócicas/mortalidade , Staphylococcus aureus/efeitos dos fármacos , Staphylococcus aureus/patogenicidade , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Antibacterianos/farmacologia , Técnicas Bacteriológicas , Meios de Cultura , Hospitalização/estatística & dados numéricos , Humanos , Tempo de Internação/estatística & dados numéricos , Meticilina/farmacologia , Pessoa de Meia-Idade , Prognóstico , Infecções Estafilocócicas/microbiologia , Staphylococcus aureus/isolamento & purificação , Fatores de Tempo
13.
Eur J Clin Microbiol Infect Dis ; 25(12): 751-5, 2006 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-17072575

RESUMO

Nosocomial diarrhea caused by Clostridium difficile causes significant morbidity and mortality in an increasing proportion of hospitalized patients annually. This case-control study of patients admitted to the hematology-oncology ward of a tertiary academic medical center over a 2-year period demonstrates that patients with Clostridium difficile-associated diarrhea (CDAD) were 22 times more likely than ward-matched controls with diarrhea to have received any antibiotic either during hospitalization or in the month preceding admission (p < 0.005), and they were nearly three times as likely as controls to have received a cephalosporin during the same period (p < 0.005). Diarrhea among lung cancer patients was approximately three times more likely to be caused by this organism than to be due to other causes (p = 0.04). A trend towards CDAD patients receiving higher numbers of different antibiotics during hospitalization (3.3 vs. 2.6, 95%CI -1.42-0.02, p = 0.06) was noted. Administration of interleukin-2 either during hospitalization or in the 30 days preceding admission was seven times more likely to have occurred in CDAD cases (p = 0.04), raising the question of whether or not this agent increases risk.


Assuntos
Antibacterianos/efeitos adversos , Toxinas Bacterianas/isolamento & purificação , Cefalosporinas/efeitos adversos , Clostridioides difficile/efeitos dos fármacos , Infecções por Clostridium/etiologia , Infecção Hospitalar/microbiologia , Diarreia/microbiologia , Enterotoxinas/isolamento & purificação , Adulto , Idoso , Estudos de Casos e Controles , Clostridioides difficile/patogenicidade , Diarreia/etiologia , Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos , Feminino , Humanos , Neoplasias Pulmonares/complicações , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Fatores de Risco
14.
J Occup Environ Hyg ; 2(5): 251-6, 2005 May.
Artigo em Inglês | MEDLINE | ID: mdl-15804982

RESUMO

Threshold limit values for heat stress and strain are based on an upper limit wet bulb globe temperature (WBGT) for ordinary work clothes, with clothing adjustment factors (CAF) for other clothing ensembles. The purpose of this study was to determine the CAF for four clothing ensembles (Cotton Coveralls, Tyvek 1424 Coveralls, NexGen Coveralls, and Tychem QC Coveralls) against a baseline of cotton work clothes and to determine what effect relative humidity may have. A climatic chamber was used to slowly increase the level of heat stress by increasing air temperature at three levels of relative humidity (20%, 50%, and 70%). Study participants wore one of the five ensembles while walking on a treadmill at a moderate metabolic rate of 155 W m-2 (about 300 W). Physiological data and environmental data were collected. When the participant's core temperature reached a steady state, the dry bulb temperature was increased at constant relative humidity. The point at which the core temperature began to increase was defined as the inflection point. The environmental temperature recorded 5 min before the inflection point was used to calculate the critical WBGT for each ensemble. A three-way analysis of variance with ensemble by humidity protocol interactions and a multiple comparison test were used to make comparisons among the mean values. Only the vapor-barrier ensemble (Tychem QC) demonstrated an interaction with humidity level. The following CAFs are proposed: Cotton Coveralls (0 degrees C-WBGT), Tyvek 1424 Coveralls (+1), NexGen Coveralls (+2), and Tychem QC Coveralls (+10).


Assuntos
Vestuário , Transtornos de Estresse por Calor/prevenção & controle , Umidade , Saúde Ocupacional , Adulto , Feminino , Humanos , Masculino , Manufaturas , Valores de Referência , Temperatura , Níveis Máximos Permitidos
15.
Philos Trans R Soc Lond B Biol Sci ; 357(1428): 1835-41, 2002 Dec 29.
Artigo em Inglês | MEDLINE | ID: mdl-12626016

RESUMO

In this paper, we review recent work on aspects of corticothalamic interactions in the auditory and in the visual systems. There are gross similarities in the arrangements of these systems, but considerable contrasts in the processing computations and in the effects of corticothalamic feedback.


Assuntos
Córtex Cerebral/fisiologia , Tálamo/fisiologia , Animais , Córtex Auditivo/fisiologia , Retroalimentação , Corpos Geniculados/fisiologia , Audição/fisiologia , Modelos Neurológicos , Vias Neurais/fisiologia , Córtex Visual/fisiologia
16.
Bioorg Med Chem Lett ; 11(20): 2769-73, 2001 Oct 22.
Artigo em Inglês | MEDLINE | ID: mdl-11591520

RESUMO

Exploration of the SAR around selective NK2 antagonists, SR48968 and ZD7944, led to the discovery that naphth-1-amide analogues provide potent dual NK1 and NK2 antagonists. ZD6021 inhibited binding of [3H]-NKA or [3H]-SP to human NK1 and NK2 receptors, with high-affinity (K(i)=0.12 and 0.62nM, respectively). In functional assays ZD6021 had, at 10(-7)M, in human pulmonary artery pK(B)=8.9 and in human bronchus pK(B)=7.3, for NK1 and NK2, respectively. Oral administration of ZD6021 to guinea pigs dose-dependently attenuated ASMSP induced extravasation of plasma proteins, ED(50)=0.5mg/kg, and NK2 mediated bronchoconstriction, ED(50)=13mg/kg.


Assuntos
Benzamidas/farmacologia , Antagonistas dos Receptores de Neurocinina-1 , Piperidinas/farmacologia , Receptores da Neurocinina-2/antagonistas & inibidores , Sulfóxidos/farmacologia , Administração Oral , Animais , Benzamidas/química , Benzamidas/farmacocinética , Cães , Relação Dose-Resposta a Droga , Cobaias , Modelos Animais , Piperidinas/química , Piperidinas/farmacocinética , Ratos , Relação Estrutura-Atividade , Sulfóxidos/química , Sulfóxidos/farmacocinética
17.
Neural Netw ; 14(6-7): 589-98, 2001.
Artigo em Inglês | MEDLINE | ID: mdl-11665755

RESUMO

Neurons often work together to compute and process information, and neural assemblies arise from synaptic interactions and neural circuits. One way to study neural assemblies is to simultaneously record from several or many neurons and study the statistical relations among their spike trains. From this analysis researchers can try to understand the nature of the assemblies, which can also lead to attempts at modeling the underlying mechanisms. In this review we discuss three important parts of this process: (1) technical issues related to simultaneously recording more than one single unit, (2) ways of analyzing the data and (3) recent models offering hypothetical mechanisms of neural assemblies, especially models which incorporate feedback.


Assuntos
Potenciais de Ação/fisiologia , Sistema Nervoso Central/fisiologia , Modelos Neurológicos , Rede Nervosa/fisiologia , Neurônios/fisiologia , Algoritmos , Animais , Retroalimentação/fisiologia , Humanos
19.
J Med Chem ; 44(3): 372-89, 2001 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-11462978

RESUMO

A great need exists for antipsychotic drugs which will not induce extrapyramidal symptoms (EPS) and tardive dyskinesias (TDs). These side effects are deemed to be a consequence of nonselective blockade of nigrostriatal and mesolimbic dopamine D2 receptors. Nondyskinetic clozapine (1) is a low-potency D2 dopamine receptor antagonist which appears to act selectively in the mesolimbic area. In this work dopamine antagonism was assessed in two mouse behavioral assays: antagonism of apomorphine-induced climbing and antagonism of apomorphine-induced disruption of swimming. The potential for the liability of dyskinesias was determined in haloperidol-sensitized Cebus monkeys. Initial examination of a few close cogeners of 1 enhanced confidence in the Cebus model as a predictor of dyskinetic potential. Considering dibenzazepines, 2 was not dyskinetic whereas 2a was dyskinetic. Among dibenzodiazepines, 1 did not induce dyskinesias whereas its N-2-(2-hydroxyethoxy)ethyl analogue 3 was dyskinetic. The emergence of such distinctions presented an opportunity. Thus, aromatic and N-substituted analogues of 6-(piperazin-1-yl)-11H-dibenz[b,e]azepines and 11-(piperazin-1-yl)dibenzo[b,f][1,4]thiazepines and -oxazepines were prepared and evaluated. 11-(4-[2-(2-Hydroxyethoxy)ethyl]piperazin-1-yl)dibenzo[b,f][1,4]thiazepine (23) was found to be an apomorphine antagonist comparable to clozapine. It was essentially nondyskinetic in the Cebus model. With 23 as a platform, a number of N-substituted analogues were found to be good apomorphine antagonists but all were dyskinetic.


Assuntos
Antipsicóticos/farmacologia , Comportamento Animal/efeitos dos fármacos , Dibenzotiazepinas/farmacologia , Antagonistas de Dopamina/farmacologia , Discinesia Induzida por Medicamentos/etiologia , Receptores de Dopamina D2/efeitos dos fármacos , Animais , Antipsicóticos/efeitos adversos , Antipsicóticos/química , Apomorfina/farmacologia , Cebus , Dibenzotiazepinas/efeitos adversos , Dibenzotiazepinas/química , Antagonistas de Dopamina/efeitos adversos , Antagonistas de Dopamina/química , Feminino , Masculino , Camundongos , Fumarato de Quetiapina , Estereoisomerismo , Relação Estrutura-Atividade
20.
J Neurophysiol ; 84(4): 1863-8, 2000 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-11024078

RESUMO

We have previously developed a model of the corticogeniculate system to explore cortically induced synchronization of lateral geniculate nucleus (LGN) neurons. Our model was based on the experiments of Sillito et al. Recently Brody discovered that the LGN events found by Sillito et al. correlate over a much longer period of time than expected from the stimulus-driven responses and proposed a cortically induced slow covariation in LGN cell membrane potentials to account for this phenomenon. We have examined the data from our model, and we found, to our surprise, that the model shows the same long-term correlation. The model's behavior was the result of a previously unsuspected oscillatory effect, not a slow covariation. The oscillations were in the same frequency range as the well-known spindle oscillations of the thalamocortical system. In the model, the strength of feedback inhibition from the cortex and the presence of low-threshold calcium channels in LGN cells were important. We also found that by making the oscillations more pronounced, we could get a better fit to the experimental data.


Assuntos
Corpos Geniculados/fisiologia , Modelos Neurológicos , Córtex Visual/fisiologia , Simulação por Computador , Eletrofisiologia , Oscilometria , Fatores de Tempo
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