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1.
Bone Marrow Transplant ; 46(1): 59-63, 2011 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-20421869

RESUMO

Lenalidomide is an active treatment for multiple myeloma (MM) and is increasingly used as part of the initial treatment of this disease. Recent reports have suggested decreases in the number of CD34+ cells collected and increases in the failure rate among patients whose initial therapy contained lenalidomide when mobilized with G-CSF alone. A retrospective data analysis of 364 patients with MM who underwent stem cell mobilization and attempted harvest at the Hospital of the University of Pennsylvania between January 2002 and December 2007 was performed. Forty-three of the patients received lenalidomide in their induction regimen, and were mobilized with either CY and G-CSF or G-CSF alone. The number of apheresis cycles and the failure rate were lower, whereas the mean number of collected stem cells was higher in patients who were mobilized with CY and G-CSF in comparison with G-CSF alone. This suggests that lenalidomide does not prevent the harvest of adequate numbers of CD34 cells for autologous stem cell transplant, but mobilization with G-CSF and CY may be required to obtain adequate numbers of stem cells. Finally, in our study, the number of lenalidomide cycles did not correlate with stem cell yield.


Assuntos
Antineoplásicos/uso terapêutico , Ciclofosfamida/uso terapêutico , Fator Estimulador de Colônias de Granulócitos/uso terapêutico , Mobilização de Células-Tronco Hematopoéticas/métodos , Mieloma Múltiplo/terapia , Transplante de Células-Tronco de Sangue Periférico , Talidomida/análogos & derivados , Antígenos CD34/sangue , Antineoplásicos/administração & dosagem , Antineoplásicos/efeitos adversos , Remoção de Componentes Sanguíneos/estatística & dados numéricos , Quimioterapia Combinada , Humanos , Lenalidomida , Prontuários Médicos , Mieloma Múltiplo/sangue , Indução de Remissão/métodos , Estudos Retrospectivos , Talidomida/administração & dosagem , Talidomida/efeitos adversos , Talidomida/uso terapêutico , Condicionamento Pré-Transplante/efeitos adversos , Condicionamento Pré-Transplante/métodos , Transplante Autólogo , Resultado do Tratamento
2.
Bone Marrow Transplant ; 43(5): 417-22, 2009 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-18850013

RESUMO

Therapeutic options for patients with multiple myeloma whose disease has relapsed after a prior auto-SCT include novel biologic therapies, traditional chemotherapy or a second transplant, with no clear standard of care. Few published studies address the safety and efficacy of a second auto-SCT for relapsed disease. We reviewed the Abramson Cancer Center experience with salvage auto-SCT for relapsed multiple myeloma. Forty-one patients had received a salvage auto-SCT at our institution; the median time between transplants was 37 months (range 3-91). The overall response rate in assessable patients was 55%, and treatment-related mortality was 7%. With a median follow-up time of 15 months, the median PFS was 8.5 months and the median overall survival (OS) was 20.7 months. In a multivariate analysis of OS, independent prognostic factors were >or=5 prior lines of therapy and time to progression after initial auto-SCT of

Assuntos
Transplante de Células-Tronco Hematopoéticas , Mieloma Múltiplo/terapia , Terapia de Salvação/métodos , Adulto , Idoso , Progressão da Doença , Feminino , Seguimentos , Transplante de Células-Tronco Hematopoéticas/efeitos adversos , Transplante de Células-Tronco Hematopoéticas/mortalidade , Humanos , Masculino , Pessoa de Meia-Idade , Mieloma Múltiplo/mortalidade , Prognóstico , Recidiva , Transplante Autólogo
3.
Bone Marrow Transplant ; 36(11): 955-61, 2005 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-16205727

RESUMO

Although follicular lymphoma (FL) is generally responsive to conventional-dose chemotherapy, improved survival in patients with this disease has been difficult to demonstrate. High-dose chemo/radiotherapy followed by autologous stem-cell transplantation (ASCT) can improve response rates, although its effects on survival remain controversial. Between 1990 and 2003, we transplanted 49 patients with low-grade FL at our institution. Twenty-two patients (45%) had undergone histologic transformation at the time of ASCT. In all, 44 patients (90%) had relapsed disease and five patients (10%) were resistant to chemotherapy at the time of transplantation. After ASCT, 30 patients (61%) were in complete remission (CR). The median overall survival (OS) has not been reached, while the median event-free survival (EFS) is 2.4 years. At a median follow-up of 5.5 years (longest 12.4 years), a plateau has been reached with 56% of patients remaining alive, and 35% event-free. ASCT was well tolerated except for two (4%) treatment-related deaths. In multivariable analysis, CR after ASCT and age less than 60 years are the best predictors of EFS and OS. ASCT is thus a safe therapeutic approach in FL, resulting in long-term EFS and OS for some patients, even with transformed disease.


Assuntos
Antineoplásicos/administração & dosagem , Transplante de Células-Tronco Hematopoéticas/métodos , Linfoma Folicular/terapia , Linfoma não Hodgkin/terapia , Sobreviventes , Adulto , Fatores Etários , Idoso , Intervalo Livre de Doença , Resistencia a Medicamentos Antineoplásicos , Feminino , Seguimentos , Transplante de Células-Tronco Hematopoéticas/mortalidade , Humanos , Linfoma Folicular/mortalidade , Linfoma Folicular/patologia , Linfoma não Hodgkin/mortalidade , Linfoma não Hodgkin/patologia , Masculino , Pessoa de Meia-Idade , Prognóstico , Indução de Remissão , Estudos Retrospectivos , Análise de Sobrevida , Transplante Autólogo
4.
Bone Marrow Transplant ; 30(1): 23-8, 2002 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-12105773

RESUMO

Gemtuzumab ozogamicin (GO) (Mylotarg, CMA-676) is a novel chemotherapeutic agent consisting of an anti-CD33 monoclonal antibody linked to calicheamicin, and is associated with a 30% response rate in patients with CD33-positive acute myeloid leukemia (AML) in first relapse. GO therapy has a 20% incidence of grade 3 or 4 hepatotoxicity, and has recently been associated with hepatic veno-occlusive disease (VOD). The efficacy and toxicity of GO in patients with AML who have relapsed after hematopoietic stem cell transplant (HSCT) is unknown, as this population was largely excluded from phase II studies. We reviewed the outcomes of eight consecutive patients with AML who received GO following relapse after HSCT. Two (25%) had responses to GO. One patient, who had had two previous HSCT and prior hyperbilirubinemia, developed severe VOD and died 14 days after GO therapy. The other seven patients did not meet diagnostic criteria for VOD. We conclude that GO can be safe and effective in patients who relapse following HSCT, but that caution is warranted in patients with multiple risk factors for VOD.


Assuntos
Aminoglicosídeos , Antibacterianos/administração & dosagem , Anticorpos Monoclonais/administração & dosagem , Transplante de Células-Tronco Hematopoéticas , Leucemia Mieloide/tratamento farmacológico , Doença Aguda , Adolescente , Adulto , Antibacterianos/toxicidade , Anticorpos Monoclonais/toxicidade , Anticorpos Monoclonais Humanizados , Causas de Morte , Feminino , Gemtuzumab , Hepatopatia Veno-Oclusiva/induzido quimicamente , Hepatopatia Veno-Oclusiva/etiologia , Humanos , Imunotoxinas/administração & dosagem , Imunotoxinas/toxicidade , Incidência , Leucemia Mieloide/complicações , Leucemia Mieloide/terapia , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Terapia de Salvação , Equivalência Terapêutica , Resultado do Tratamento
5.
Epilepsia ; 42(8): 967-78, 2001 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-11554881

RESUMO

PURPOSE: In limbic or mesial temporal lobe epilepsy, much attention has been given to specific regions or cell populations (e.g., the hippocampus or dentate granule cells). Epileptic seizures may involve broader changes in neural circuits, and evidence suggests that subcortical regions may play a role. In this study we examined the midline thalamic regions for involvement in limbic seizures, changes in anatomy and physiology, and the potential role for this region in limbic seizures and epilepsy. METHODS: Using two rat models for limbic epilepsy (hippocampal kindled and chronic spontaneous limbic epilepsy) we examined the midline thalamus for evidence of involvement in seizure activity, alterations in structure, changes in the basic in vitro physiology of the thalamic neurons. We also explored how this region may influence limbic seizures. RESULTS: The midline thalamus was consistently involved with seizure activity from the onset, and there was significant neuronal loss in the medial dorsal and reuniens/rhomboid nuclei. In addition, thalamic neurons had changes in synaptically mediated and voltage-gated responses. Infusion of lidocaine into the midline thalamus significantly shortened afterdischarge duration. CONCLUSIONS: These observations suggest that this thalamic region is part of the neural circuitry of limbic epilepsy and may play a significant role in seizure modulation. Local neuronal changes can enhance the excitability of the thalamolimbic circuits.


Assuntos
Epilepsia do Lobo Temporal/fisiopatologia , Sistema Límbico/fisiopatologia , Tálamo/fisiopatologia , Anatomia Transversal , Animais , Contagem de Células , Modelos Animais de Doenças , Estimulação Elétrica , Eletrodos Implantados , Hipocampo/citologia , Hipocampo/fisiologia , Hipocampo/fisiopatologia , Excitação Neurológica/fisiologia , Lidocaína/farmacologia , Sistema Límbico/citologia , Sistema Límbico/fisiologia , Masculino , Vias Neurais/citologia , Vias Neurais/fisiologia , Vias Neurais/fisiopatologia , Neurônios/citologia , Neurônios/fisiologia , Ratos , Ratos Sprague-Dawley , Núcleos Talâmicos/citologia , Núcleos Talâmicos/efeitos dos fármacos , Núcleos Talâmicos/fisiologia , Tálamo/citologia , Tálamo/efeitos dos fármacos
6.
Arterioscler Thromb Vasc Biol ; 21(8): 1265-8, 2001 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-11498451

RESUMO

Matrix metalloproteinases (MMPs), proteolytic enzymes produced by monocytes, may contribute to atherosclerotic arterial wall remodeling and to plaque rupture. Because estrogen influences the synthesis of MMPs, we examined the effect of raloxifene, a selective estrogen receptor modulator, on monocyte MMP production. Human primary blood monocytes treated with raloxifene (10 micromol/L) in the presence of lipopolysaccharide (LPS) or tumor necrosis factor-alpha and granulocyte-macrophage colony-stimulating factor induced a 2- to 3-fold increase in MMP-1 production by monocytes. The enhancement of MMP-1 production by raloxifene in LPS-activated monocytes occurred through a cyclooxygenase-2- and prostaglandin E(2)-independent mechanism. Additionally, compared with monocytes acquired during the placebo phase, peripheral blood monocytes from 5 of 6 healthy postmenopausal women treated with raloxifene (60 mg daily for 1 month) in a clinical trial produced significantly higher levels of MMP-1 when the monocytes were activated with LPS. Furthermore, serum obtained during the raloxifene phase from 4 of these subjects, when added to control monocytes, significantly enhanced LPS-induced MMP-1 production compared with that from serum obtained during the placebo phase. In summary, raloxifene increases the production of MMP-1 in activated monocytes; this effect may be favorable in atherosclerotic arterial wall remodeling but unfavorable for plaque stability.


Assuntos
Arteriosclerose/sangue , Metaloproteinase 1 da Matriz/biossíntese , Monócitos/efeitos dos fármacos , Cloridrato de Raloxifeno/farmacologia , Moduladores Seletivos de Receptor Estrogênico/farmacologia , Células Cultivadas , Ciclo-Oxigenase 2 , Dinoprostona/biossíntese , Método Duplo-Cego , Feminino , Fator Estimulador de Colônias de Granulócitos e Macrófagos/farmacologia , Humanos , Isoenzimas/biossíntese , Lipopolissacarídeos/farmacologia , Metaloproteinase 1 da Matriz/metabolismo , Proteínas de Membrana , Monócitos/metabolismo , Pós-Menopausa , Prostaglandina-Endoperóxido Sintases/biossíntese , Cloridrato de Raloxifeno/uso terapêutico , Ensaios Clínicos Controlados Aleatórios como Assunto , Moduladores Seletivos de Receptor Estrogênico/uso terapêutico , Fator de Necrose Tumoral alfa/farmacologia
7.
J Biol Chem ; 276(22): 19027-32, 2001 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-11259424

RESUMO

Membrane type 1-matrix metalloproteinase (MT1-MMP)-mediated activation of MMP-2 is thought to be important in the proteolysis of extracellular matrix in pathological events in which monocytes/macrophages are found. Here we report on the induction and regulation of human monocyte MT1-MMP and its role in MMP-2 activation. Activation of monocytes by lipopolysaccharide resulted in the induction of MT1-MMP mRNA and protein that was suppressed by inhibitors of prostaglandin synthesis (indomethacin), adenylyl cyclase (SQ 22536), and protein kinase A (Rp-cAMPs). Suppression of MT1-MMP by indomethacin and SQ 22536 was reversed by prostaglandin E(2) and dibutyryl cyclic AMP, respectively, demonstrating that induction of monocyte MT1-MMP is regulated through a prostaglandin-cAMP pathway. Functional analysis revealed that pro-MMP-2 in the supernatants from human bone marrow stromal fibroblasts, normal male-derived fibroblasts and melanoma cells (A2058) was converted to active MMP-2 when cultured with activated but not control monocytes. Antibodies against MT1-MMP blocked the activation of MMP-2. Tissue inhibitor of metalloproteinase-2 regulation of MMP-2 activation was shown through the addition of varying amounts of recombinant tissue inhibitor of metalloproteinase-2 with pro-MMP-2 to MT1-MMP-expressing monocytes. These findings demonstrate that activated monocytes express functionally active MT1-MMP that may play a significant role in the activation of MMP-2 produced by other cells and as such influence developmental and pathological conditions.


Assuntos
Adenina/análogos & derivados , Metaloproteinase 2 da Matriz/metabolismo , Metaloendopeptidases/química , Metaloendopeptidases/fisiologia , Monócitos/enzimologia , Prostaglandinas/metabolismo , Adenina/farmacologia , Adenilil Ciclases/metabolismo , Adenilil Ciclases/farmacologia , Western Blotting , Bucladesina/farmacologia , Células Cultivadas , AMP Cíclico/metabolismo , Proteínas Quinases Dependentes de AMP Cíclico/antagonistas & inibidores , Proteínas Quinases Dependentes de AMP Cíclico/farmacologia , Dinoprostona/metabolismo , Ativação Enzimática , Inibidores Enzimáticos/farmacologia , Fibroblastos/metabolismo , Citometria de Fluxo , Humanos , Indometacina/farmacologia , Lipopolissacarídeos/farmacologia , Metaloproteinases da Matriz Associadas à Membrana , Monócitos/metabolismo , RNA/metabolismo , Inibidor Tecidual de Metaloproteinase-2/metabolismo , Inibidor Tecidual de Metaloproteinase-2/fisiologia
8.
J Am Med Womens Assoc (1972) ; 56(4): 166-73, 188, 2001.
Artigo em Inglês | MEDLINE | ID: mdl-11759785

RESUMO

OBJECTIVE: to assess the effectiveness of patient-targeted interventions in increasing mammography use when performed outside (outreach) or inside the primary care medical setting (inreach). METHODS: We performed a meta-analysis of controlled interventions to increase mammography use in patients in the United States published between 1980 and February 2001. Interventions were classified by setting (inreach or outreach), mechanism of action (behavioral, cognitive, sociologic, or a combination), type of control group (active or usual care), number of strategies, and mode of delivery (static or interactive). Summary estimates were calculated with DerSimonian and Laird random effects models for each group of interventions. RESULTS: We included 66 studies with 98 separate interventions. Inreach and outreach interventions were equally effective in increasing mammography use. Compared to active controls, behavioral interventions with multiple strategies increased mammography use by 14.0% (95% CI, 8.7-19.2) in inreach and 18.7% (95% CI, 4.9-32.4) in outreach settings. Theory-based educational strategies delivered interactively increased mammography use by 10.7% (95% CI, 6.8-14.7) and 19.9% (95% CI, 10.6-29.1) in inreach and outreach settings, respectively. Interventions that combined behavioral and theory-based educational strategies with usual care controls increased mammography use by 14.0% (95% CI, 7.9-20.2) in inreach and 27.3% (95% CI, 14.7-40.0) in outreach settings. Finally, sociologic interventions increased mammography use by 10.7% (95% CI, 3.4-18.0) and 9.1% (95% CI, 1.7-13.3) in inreach and outreach settings, respectively. CONCLUSIONS: Inreach and outreach interventions to increase mammography use were similarly effective within intervention categories based on mechanism of action, mode of delivery, and type of control group. Ultimate decisions about intervention strategies will depend on the characteristics of the target population, practical considerations, and relative cost-effectiveness.


Assuntos
Neoplasias da Mama/prevenção & controle , Mamografia/estatística & dados numéricos , Aceitação pelo Paciente de Cuidados de Saúde/psicologia , Serviços Preventivos de Saúde/estatística & dados numéricos , Relações Comunidade-Instituição , Feminino , Educação em Saúde , Humanos , Comunicação Persuasiva , Atenção Primária à Saúde , Estados Unidos
9.
Neuroscience ; 101(2): 377-91, 2000.
Artigo em Inglês | MEDLINE | ID: mdl-11074161

RESUMO

Limbic epilepsy is a chronic condition associated with a broad zone of seizure onset and pathology. Studies have focused mainly on the hippocampus, but there are indications that changes occur in other regions of the limbic system. This study used in vitro intracellular recording and histology to examine alterations to the physiology and anatomy of the basal nucleus of the amygdala in a rat model of chronic limbic epilepsy characterized by spontaneously recurring seizures. Epileptic pyramidal neuron responses evoked by stria terminalis stimulation revealed hyperexcitability characterized by multiple action potential bursts and no evident inhibitory potentials. In contrast, no hyperexcitability was observed in amygdalar neurons from kindled (included as a control for seizure activity) or control rats. Blockade of ionotropic glutamate receptors unmasked inhibitory postsynaptic potentials in epileptic pyramidal neurons. Control, kindled and epileptic inhibitory potentials were predominantly biphasic, with fast and slow components, but a few cells exhibited only the fast component (2/12 in controls, 0/3 in kindled, 3/10 in epileptic). Epileptic fast inhibitory potentials had a more rapid onset and shorter duration than control and kindled. Approximately 40% of control neurons exhibited spontaneous inhibitory potentials; no spontaneous inhibitory potentials were observed in neurons from kindled or epileptic rats. A preliminary histological examination revealed no gross alterations in the basal amygdala from epileptic animals. These results extend previous findings from this laboratory that hyperexcitability is found in multiple epileptic limbic regions and may be secondary to multiple alterations in excitatory and inhibitory efficacy. Because there were no differences between control and kindled animals, the changes observed in the epileptic animals are unlikely to be secondary to recurrent seizures.


Assuntos
Potenciais de Ação/fisiologia , Tonsila do Cerebelo/fisiopatologia , Epilepsia/fisiopatologia , Neurônios/fisiologia , Valina/análogos & derivados , Tonsila do Cerebelo/patologia , Animais , Modelos Animais de Doenças , Estimulação Elétrica/efeitos adversos , Epilepsia/patologia , Antagonistas de Aminoácidos Excitatórios/farmacologia , Potenciais Pós-Sinápticos Excitadores/fisiologia , Antagonistas GABAérgicos/farmacologia , Excitação Neurológica/fisiologia , Vias Neurais/patologia , Vias Neurais/fisiopatologia , Neurônios/classificação , Neurônios/citologia , Ácidos Fosfínicos/farmacologia , Propanolaminas/farmacologia , Quinoxalinas/farmacologia , Ratos , Valina/farmacologia
12.
Ann Oncol ; 10(8): 929-36, 1999 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-10509154

RESUMO

BACKGROUND: High-dose chemotherapy with autologous stem-cell transplantation is used increasingly in the treatment of poor-prognosis primary breast cancer. Because these patients may be cured with standard multimodality therapy, it is important to address both the efficacy of transplantation, and its effect on the delivery of standard treatments including local radiation therapy. PATIENTS AND METHODS: Patients with high risk primary breast cancer were treated with high-dose cyclophosphamide and thiotepa and stem-cell transplant following surgery and conventional-dose adjuvant chemotherapy. Outcome, including sites of failure and delivery of local radiation therapy, was assessed for 103 patients. RESULTS: Overall and disease-free survival rates at 18 months were 83% (+/- 4%) and 77% (+/- 4%) respectively. Twenty patients (19.4%) received radiation therapy prior to transplant. Of the remaining 83, 77 received radiation therapy after transplant. Overall, 5 (19.2%) of 26 first sites of recurrence were local alone. For patients receiving radiation prior to transplant, 3 of 7 (43%, 95% CI: 6%-80%) sites of first recurrence were local, while 2 of 19 (10.5%, 95% CI: 0%-24.5%) sites of first recurrence were local alone in patients receiving post-transplant radiation or no radiation. CONCLUSION: Transplantation does not appear to significantly compromise the delivery or outcome of local radiation therapy for primary breast cancer.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Neoplasias da Mama/terapia , Transplante de Células-Tronco Hematopoéticas/métodos , Adulto , Antineoplásicos Alquilantes/administração & dosagem , Neoplasias da Mama/mortalidade , Neoplasias da Mama/patologia , Quimioterapia Adjuvante , Terapia Combinada , Intervalos de Confiança , Ciclofosfamida/administração & dosagem , Intervalo Livre de Doença , Relação Dose-Resposta a Droga , Feminino , Humanos , Mastectomia/métodos , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Prognóstico , Radioterapia Adjuvante , Índice de Gravidade de Doença , Análise de Sobrevida , Tiotepa/administração & dosagem , Resultado do Tratamento
13.
Med Oncol ; 16(4): 279-88, 1999 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-10618691

RESUMO

The purpose of this study was to determine the efficacy, engraftment kinetics, effect of bone marrow tumor contamination, and safety of high-dose therapy and granulocyte-colony stimulating factor (G-CSF) mobilized peripheral blood progenitor cell (PBPC) support for patients with responding metastatic breast cancer. Forty two patients underwent G-CSF (10 microg/kg) stimulated PBPC harvest. PBPC and bone marrow aspirates were analyzed by histologic and immunocytochemical methods for tumor contamination. Thirty-seven patients received high-dose therapy consisting of cyclophosphamide 6 g/m2, thiotepa 500 mg/m2, and carboplatin 800 mg/m2 (CTCb) given as an infusion over 4 d followed by PBPC reinfusion and G-CSF (5 microg/kg) support. No transplant related deaths or grade 4 toxicity was recorded. CD34+ cells/kg infused was predictive of neutrophil and platelet recovery. With a median follow-up of 38 months, three year survival was 44% with relapse-free survival of 19%. Histological bone marrow involvement, found in 10 patients, was a negative prognostic factor and was associated with a median relapse-free survival of 3.5 months. Tumor contamination of PBPC by immunohistochemical staining was present in 22.5% of patients and found not to be correlated with decreased survival. G-CSF stimulated PBPC collection followed by a single course of high dose chemotherapy and stem cell infusion with G-CSF stimulated marrow recovery leads to rapid, reliable engraftment with low toxicity and promising outcome in women with responding metastatic breast cancer.


Assuntos
Neoplasias da Mama/patologia , Neoplasias da Mama/terapia , Transplante de Células-Tronco Hematopoéticas , Células-Tronco Hematopoéticas/patologia , Adulto , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Neoplasias da Medula Óssea/secundário , Neoplasias Ósseas/secundário , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/mortalidade , Feminino , Fator Estimulador de Colônias de Granulócitos/uso terapêutico , Mobilização de Células-Tronco Hematopoéticas/efeitos adversos , Transplante de Células-Tronco Hematopoéticas/efeitos adversos , Humanos , Pessoa de Meia-Idade , Recidiva Local de Neoplasia , Células Neoplásicas Circulantes/patologia , Estudos Prospectivos
15.
Epilepsy Res ; 32(1-2): 194-205, 1998 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-9761320

RESUMO

The limbic/mesial temporal lobe epilepsy syndrome has been defined as a focal epilepsy, with the implication that there is a well defined focus of onset, traditionally centered around the hippocampus. The pathology of the hippocampus in this syndrome has been well described and a number of physiological abnormalities have been defined in this structure in animal models and humans with epilepsy. However, anatomical and physiological abnormalities have also been described in other limbic sites in this form of epilepsy. Previous studies have shown broadly synchronized or multifocal seizure onset within the limbic system of the animal models and human patients. We hypothesized that the epileptogenic circuit for the initiation of seizures was distributed throughout the limbic system with a possible central synchronizing process. In vitro studies showed that multiple limbic sites in epileptic animals (hippocampus, entorhinal cortex, piriform cortex and amygdala) have epileptiform changes with prolonged depolarizations and multiple superimposed action potentials. In vivo studies revealed that thalamic stimulation yields short latency excitatory responses in the entorhinal cortex and hippocampus. In addition, in epileptic animals, thalamic stimulation caused epileptiform responses in the hippocampus. Based on the findings of this study and on previous anatomy and physiology reports, we hypothesize that the process of seizure initiation involves broad circuit interactions involving multiple independent limbic structures, and that the midline thalamus may act as a physiological synchronizer. We offer a new proposal for the functional anatomy of limbic epilepsy that takes widespread hyperexcitability in the limbic system and the potential for thalamic synchronization into consideration.


Assuntos
Encéfalo/anatomia & histologia , Encéfalo/fisiopatologia , Epilepsia do Lobo Temporal/fisiopatologia , Sistema Límbico/anatomia & histologia , Sistema Límbico/fisiopatologia , Animais , Encéfalo/fisiologia , Modelos Animais de Doenças , Humanos , Masculino , Modelos Neurológicos , Rede Nervosa/anatomia & histologia , Rede Nervosa/fisiopatologia , Ratos , Ratos Sprague-Dawley
16.
17.
Food Chem Toxicol ; 36(7): 169-82, 1998 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-9687969

RESUMO

A new-technology cigarette has been developed. While the new cigarette burns some tobacco, it does not use tobacco as the fuel to sustain combustion and provide heat to the cigarette. Rather, the new cigarette primarily heats tobacco thereby reducing products of smoke formation mechanisms such as tobacco combustion, tobacco pyrolysis and pyrosynthesis. The mainstream smoke composition from a cigarette based on the new design (TOB-HT) has been characterized in comparative chemical testing with two reference cigarettes using the FTC puffing regimen. Thermal properties, UV absorption characteristics, elemental composition and materials balance studies all suggest a simplified smoke aerosol. Twenty-five smoke constituents ("target compounds") identified by the scientific community as compounds that may contribute to the diseases statistically associated with smoking have also been measured. Mainstream smoke concentrations of most target compounds are significantly lower with the TOB-HT cigarette when compared with reference cigarettes in the ultra-light "tar" and light "tar" categories. Taken together, chemical analysis results suggest simplified TOB-HT smoke chemistry with marked reductions in specific chemicals reported to be biologically active.


Assuntos
Nicotiana/química , Plantas Tóxicas , Poluição por Fumaça de Tabaco/análise , Cromatografia Gasosa-Espectrometria de Massas , Temperatura Alta , Nicotina/análise , Nitrosaminas/análise , Fumar , Alcatrões/análise , Indústria do Tabaco , Testes de Toxicidade
18.
Brain Res ; 799(2): 183-96, 1998 Jul 20.
Artigo em Inglês | MEDLINE | ID: mdl-9675275

RESUMO

In the limbic status model of chronic temporal lobe epilepsy, hippocampal stimulation induces acute status epilepticus in rats; recurrent, spontaneous seizures develop following an asymptomatic silent period lasting several weeks. Previous work has shown increased excitability and decreased inhibition in CA1 pyramidal neurons in chronically epileptic animals. To determine the relationship of altered cellular responses to seizure onset, in vitro intracellular recording was used to follow the evolution of changes in synaptic physiology occurring during the seizure-free silent period. Pyramidal cells displayed increasing epileptiform activity throughout the period investigated, 3-14 days following status; the mean number of evoked action potentials from 1.1+/-0.05 in control cells to 2.4+/-0.4 early (3 days after status) and 4. 3+/-0.7 late (14 days) in the silent period. Monosynaptic inhibitory postsynaptic potentials mediated by gamma-aminobutyric acid-A receptors in silent period cells differed markedly from controls. Area, rise time, and duration of these potentials decreased by 40-60% within 3 days following status and to values commensurate with chronically epileptic animals in 7 to 10 days. gamma-Aminobutyric acid-B receptor-mediated IPSPs diminished more gradually in the silent period, reaching a minimum at day 14. In contrast, presynaptic gamma-aminobutyric acid-B receptor function showed maximum impairment 3 days after status. The benzodiazepine type 1 receptor agonist zolpidem reduced hyperexcitability in both silent period and chronically epileptic cells, but was more effective at unmasking the underlying IPSP in silent period neurons. The results indicate that changes in different components of pyramidal cell inhibitory synaptic physiology associated with chronic epilepsy in this model evolve individually at different rates, but are all complete before seizure onset. Although the results do not imply causality, they do suggest that the development of physiological changes in CA1 pyramidal cells may contribute to the lag period preceding the onset of chronic seizures.


Assuntos
Epilepsia do Lobo Temporal/fisiopatologia , Sinapses/fisiologia , Animais , Doença Crônica , Eletrofisiologia , Epilepsia do Lobo Temporal/patologia , Hipocampo/efeitos dos fármacos , Hipocampo/patologia , Hipocampo/fisiopatologia , Terminações Pré-Sinápticas/metabolismo , Células Piramidais/efeitos dos fármacos , Células Piramidais/fisiologia , Piridinas/farmacologia , Ratos , Receptores de GABA-A/fisiologia , Receptores de GABA-B/fisiologia , Fatores de Tempo , Zolpidem
19.
Food Chem Toxicol ; 36(3): 169-82, 1998 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-9609390

RESUMO

A new-technology cigarette has been developed. While the new cigarette burns some tobacco, it does not use tobacco as the fuel to sustain combustion and provide heat to the cigarette. Rather, the new cigarette primarily heats tobacco thereby reducing products of smoke formation mechanisms such as tobacco combustion, tobacco pyrolysis and pyrosynthesis. The mainstream smoke composition from a cigarette based on the new design (TOB-HT) has been characterized in comparative chemical testing with two reference cigarettes using the FTC puffing regimen. Thermal properties, UV absorption characteristics, elemental composition and materials balance studies all suggest a simplified smoke aerosol. Twenty-five smoke constituents ("target compounds") identified by the scientific community as compounds that may contribute to the diseases statistically associated with smoking have also been measured. Mainstream smoke concentrations of most target compounds are significantly lower with the TOB-HT cigarette when compared with reference cigarettes in the ultra-light "tar" and light "tar" categories. Taken together, chemical analysis results suggest simplified TOB-HT smoke chemistry with marked reductions in specific chemicals reported to be biologically active.


Assuntos
Nicotiana/química , Plantas Tóxicas , Poluição por Fumaça de Tabaco/análise , Temperatura Alta , Nicotina/análise , Nitrosaminas/análise , Fumar , Alcatrões/análise , Indústria do Tabaco , Testes de Toxicidade
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