RESUMO
OBJECTIVES: Paediatric feeding difficulties are common, affecting up to 25% of otherwise healthy children, symptoms include food refusal, gagging, choking, and excessive mealtime duration. These symptoms are commonly described in pre-operative discussions about tonsillectomy. This prospective study explores the impact of tonsillectomy on paediatric feeding difficulties. DESIGN: This prospective cohort study invited caregivers of children undergoing tonsillectomy to complete a PediEAT questionnaire about their children's feeding behaviours, pre and post-operatively. The study was completed in two phases with 9 questions administered in phase 1 and three additional questions added for phase 2. A free text comments box was also provided. Responses were graded from 0 to 5, where 0 is 'never a problem' and 5 is 'always a problem' with eating behaviours. SETTING: The study was conducted at our institution, a tertiary paediatric ENT unit. PARTICIPANTS: Children aged between 6 months - 7 years undergoing tonsillectomy for any indication were invited to participate. MAIN OUTCOME MEASURES: Changes to the Pedi-EAT scores pre and post operatively were the main outcome measure. RESULTS: 102 participants were recruited between January 2020 and January 2022. The mean age of participants was 4.1 years, 87% had a concurrent adenoidectomy. The mean time to completion of post-operative questionnaire was 23 weeks after surgery. 9 of the 12 questions showed a statistically significant improvement in post-operative scores using a paired student t-test (p < 0.05). The most significant improvements related to 'gets tired from eating and is not able to finish' (1.49 pre-op, 0.91 post op, p < 0.01) and 'eats food that needs to be chewed' (1.4 pre-op, 0.72 post-op, p < 0.01). 13% of participants only underwent tonsillectomy and this group also showed a statistically significant improvement in fatigue during eating (p < 0.05). CONCLUSION: Symptoms of fatigue during eating and avoidance of food requiring mastication are most likely to improve following tonsillectomy in children.
Assuntos
Obstrução das Vias Respiratórias , Tonsilectomia , Criança , Humanos , Lactente , Estudos Prospectivos , Adenoidectomia , Avaliação de Resultados em Cuidados de SaúdeRESUMO
BACKGROUND: Activation of wild-type p53 with the small molecule sirtuin inhibitor Tenovin-6 (Tnv-6) induces p53-dependent apoptosis in many malignant cells. In contrast, Tnv-6 reduces chronic lymphocytic leukaemia (CLL) cell viability with dysregulation of autophagy, without increasing p53-pathway activity. METHODS: Here, we have investigated whether a quiescent phenotype (unique to CLL) determines the Tnv-6 response, by comparing the effects of Tnv-6 on activated and proliferating CLL. We further studied if these responses are p53-dependent. RESULTS: Unlike quiescent cells, cell death in activated cultures treated with Tnv-6 was consistently associated with p53 upregulation. However, p53 acetylation remained unchanged, without caspase-3 cleavage or apoptosis on electron microscopy. Instead, cellular ultrastructure and protein profiles indicated autophagy inhibition, with reduced ubiquitin-proteasome activity. In specimens with mutant TP53 cultured with Tnv-6, changes in the autophagy-associated protein LC3 occurred independently of p53. Cells treated with Tnv-6 analogues lacking sirtuin inhibitory activity had attenuated LC3 lipidation compared with Tnv-6 (Pîº0.01), suggesting that autophagy dysregulation occurs predominantly through an effect on sirtuins. CONCLUSION: These cell cycle and p53-independent anti-leukaemic mechanisms potentially offer novel therapeutic approaches to target leukaemia-sustaining cells in CLL, including in disease with p53-pathway dysfunction. Whether targets in addition to sirtuins contribute to autophagy dysregulation by Tnv-6, requires further investigation.
Assuntos
Autofagia/fisiologia , Leucemia Linfocítica Crônica de Células B/metabolismo , Leucemia Linfocítica Crônica de Células B/patologia , Proteína Supressora de Tumor p53/metabolismo , Idoso , Idoso de 80 Anos ou mais , Apoptose/efeitos dos fármacos , Apoptose/genética , Autofagia/efeitos dos fármacos , Autofagia/genética , Benzamidas/farmacologia , Caspase 3/genética , Ciclo Celular/efeitos dos fármacos , Ciclo Celular/genética , Ciclo Celular/fisiologia , Proliferação de Células/efeitos dos fármacos , Humanos , Interleucina-2/farmacologia , Leucemia Linfocítica Crônica de Células B/genética , Proteínas Associadas aos Microtúbulos/genética , Pessoa de Meia-Idade , Complexo de Endopeptidases do Proteassoma/efeitos dos fármacos , Complexo de Endopeptidases do Proteassoma/genética , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/genética , Proteína Supressora de Tumor p53/genética , Ubiquitina/genética , Regulação para Cima/efeitos dos fármacos , Regulação para Cima/genéticaRESUMO
Increasing biogas production from municipal anaerobic digesters via additional loading with industrial/agricultural wastes offers a low-cost, sustainable energy generation option of significant untapped potential. In this work, bench-top reactors were used to mimic a full-scale primary sludge digester operating at an organic loading rate (OLR) of 2.4 kg COD/m3 d and a 20 d hydraulic retention time (HRT). Co-digestion of whey with primary sludge was sustained at a loading rate of 3.2 kg COD/m3 d (17 d HRT) and boosted gas production to 151% compared to primary sludge digestion alone. Addition of chemical alkalinity enabled co-digestion of whey with primary sludge to be maintained at an elevated OLR of 6.4 kg COD/m3 d (11 d HRT) with gas production increased to 208%. However, when the chemical addition was simply replaced by cow manure, stable operation was maintained at OLRs of 5.2-6.9 kg COD/m3 d (11-14 d HRT) with gas production boosted up to 268%.
Assuntos
Biocombustíveis/análise , Esterco/análise , Proteínas do Leite/química , Esgotos/análise , Animais , Bovinos , Proteínas do Soro do LeiteRESUMO
Intracellular recordings were made from locus coeruleus neurons in a brain slice preparation. Opiates and opioid peptides produced a dose-dependent, stereospecific, naloxone-reversible hyperpolarization of the neuronal membrane. This was associated with an increase in membrane conductance.
Assuntos
Endorfinas/farmacologia , Encefalina Metionina/análogos & derivados , Encefalinas/farmacologia , Locus Cerúleo/fisiologia , Derivados da Morfina/farmacologia , Naloxona/farmacologia , Neurônios/fisiologia , Animais , Cobaias , Locus Cerúleo/efeitos dos fármacos , Potenciais da Membrana/efeitos dos fármacos , Neurônios/efeitos dos fármacosRESUMO
CD38 expression is an important prognostic marker in chronic lymphocytic leukemia (CLL) with high levels of CD38 associated with shorter overall survival. In this study, we used gene expression profiling and protein analysis of highly purified cell-sorted CD38(+) and CD38(-) chronic lymphocytic leukemia cells to elucidate a molecular basis for the association between CD38 expression and inferior clinical outcome. Paired CD38(+) and CD38(-) CLL cells derived from the same patient were shown to be monoclonal by V(H) gene sequencing but despite this, CD38(+) CLL cells possessed a distinct gene expression profile when compared with their CD38(-) sub-clones. Importantly, CD38(+) CLL cells relatively over expressed vascular endothelial growth factor (VEGF) and appeared to preferentially utilize an internal autocrine VEGF survival loop. Elevated VEGF expression was associated with increased expression of the anti-apoptotic protein Mcl-1. Inhibition of VEGF receptor signaling also resulted in a reduction in cell viability. In contrast, exogenous VEGF caused a significant increase in CD38(-) CLL cell viability and a marked induction of Mcl-1; both effects were less obvious in CD38(+) CLL cells. Taken together, our data provide a biological rationale for the poor prognosis of CD38(+) CLL and indicate that both VEGF and Mcl-1 may prove to be useful therapeutic targets.
Assuntos
ADP-Ribosil Ciclase 1/sangue , ADP-Ribosil Ciclase 1/deficiência , Regulação Neoplásica da Expressão Gênica , Leucemia Linfocítica Crônica de Células B/genética , Leucemia Linfocítica Crônica de Células B/imunologia , ADP-Ribosil Ciclase 1/genética , Antígenos CD/sangue , Antígenos CD/genética , Humanos , Cadeias Pesadas de Imunoglobulinas/genética , Região Variável de Imunoglobulina/genética , Leucemia Linfocítica Crônica de Células B/mortalidade , Análise de Sequência com Séries de Oligonucleotídeos , Mapeamento por Restrição , Análise de Sobrevida , Fator A de Crescimento do Endotélio Vascular/genéticaRESUMO
Intravenous thrombolysis and percutaneous coronary intervention (PCI) are alternative treatment options for coronary reperfusion in acute myocardial infarction. Recent trials and meta-analyses have produced increasing evidence that primary coronary intervention produces better long-term outcomes for the treatment of acute myocardial infarction. Most of these studies, however, were performed in US or European healthcare systems and may not be directly transferable to an NHS setting. The widespread introduction of primary PCI would have major implications for the organisation of healthcare provision within the UK. An alternative to PCI that may produce similar outcomes at a reduced cost might be early (pre-hospital) administration of thrombolysis. In an era of unprecedented financial attention, the importance of interventions that are simultaneously beneficial to the patient and economical to the NHS has never been more important. The evidence base for primary PCI and its possible use in the NHS are discussed.
Assuntos
Angioplastia Coronária com Balão/métodos , Infarto do Miocárdio/terapia , Reperfusão Miocárdica/métodos , Terapia Trombolítica/métodos , Angioplastia Coronária com Balão/economia , Análise Custo-Benefício , Serviços Médicos de Emergência/economia , Humanos , Reperfusão Miocárdica/economia , Transferência de Pacientes/economia , Terapia Trombolítica/economia , Resultado do TratamentoRESUMO
OBJECTIVE: A variety of paediatric tracheostomy tubes are available. This article reviews the tubes in current use at Great Ormond Street Hospital for Children and Evelina London Children's Hospital. METHODS: This paper outlines our current preferences, and the particular indications for different tracheostomy tubes, speaking valves and other attachments. RESULTS: Our preferred types of tubes have undergone significant design changes. This paper also reports further experience with certain tubes that may be useful in particular circumstances. An updated sizing chart is included for reference purposes. CONCLUSION: The choice of a paediatric tracheostomy tube remains largely determined by individual clinical requirements. Although we still favour a small range of tubes for use in the majority of our patients, there are circumstances in which other varieties are indicated.
Assuntos
Traqueostomia/instrumentação , Criança , Desenho de Equipamento , Feminino , Humanos , Masculino , Fonoterapia/instrumentaçãoRESUMO
BACKGROUND: While information on how cardiac resynchronisation therapy (CRT) affects cardiac performance at rest is readily available, the mechanisms whereby CRT alters cardiac function during maximal exercise are unclear. AIMS: We examined the medium-term effects of CRT on cardiac and physical functional reserve of patients with severe heart failure (CHF) and prolonged QRS duration. METHODS: Seventeen consecutive patients with severe CHF (NYHA III-IV) and widened QRS underwent maximal cardiopulmonary exercise testing with non-invasive central haemodynamic measurements before and 6-8 weeks after CRT pacemaker implantation. RESULTS: After CRT there were significant increases in exercise cardiac output by 19.3% (P=0.0048) from 9.5+/-3.4 l min(-1), peak mean arterial blood pressure by 14.1% (P=0.0001) from 91.3+/-13.6 mm Hg, and peak cardiac power output by 37.2% (P=0.0008) from 1.92+/-0.74 W. There were no significant changes in these variables at rest. Exercise duration (+42.3%, P=0.0002), NYHA functional class (P=0.0001) and SF-36 symptom score (P=0.0006) were also significantly improved. Powerful surrogate indicators of prognosis were also significantly improved with CRT: peak O(2) consumption (+20.9%, P=0.0007), VE/VCO(2) slope (-20.0%, P=0.005) and circulatory power (+42.0%, P=0.0012). CONCLUSION: In this cohort of patients, post-implant CRT significantly improved the flow-, pressure- and power-generating capacity of the failing hearts. This may be causally related to the improvements observed in exercise capacity, functional class and symptom scores.
Assuntos
Estimulação Cardíaca Artificial , Tolerância ao Exercício , Insuficiência Cardíaca/fisiopatologia , Insuficiência Cardíaca/terapia , Idoso , Débito Cardíaco , Teste de Esforço , Feminino , Seguimentos , Indicadores Básicos de Saúde , Frequência Cardíaca , Humanos , Masculino , Pessoa de Meia-Idade , Consumo de Oxigênio , Marca-Passo Artificial , Estudos Prospectivos , Qualidade de Vida , Resistência VascularRESUMO
The growth and circulation of B lymphocytes is largely under the control of bone marrow stromal cells, cytokines and chemokines. The gene responsible for the pivotal B cell growth factor, stromal derived factor-1 (SDF-1), has recently been shown to contain a single nucleotide polymorphism G > A at position 801 which leads to higher SDF-1 secretion. This polymorphism is common in the normal population and has been shown to play a potential role in the development of both HIV and non-HIV related non-Hodgkin's lymphoma. We therefore undertook a large single-centre study to ascertain its role in the pathogenesis of two other common B-cell malignancies, notably chronic lymphocytic leukemia (CLL- 197 patients) and multiple myeloma (126 patients). We show that the 801 G > A polymorphism plays no role in the incidence of multiple myeloma or CLL nor the outcome in multiple myeloma. By contrast, it trends towards an inferior cause-specific survival in CLL.
Assuntos
Quimiocinas CXC/genética , Regulação Neoplásica da Expressão Gênica , Leucemia Linfocítica Crônica de Células B/genética , Leucemia Linfocítica Crônica de Células B/mortalidade , Mieloma Múltiplo/genética , Mieloma Múltiplo/mortalidade , Polimorfismo Genético , Adulto , Idoso , Idoso de 80 Anos ou mais , Linhagem Celular Tumoral , Quimiocina CXCL12 , Estudos de Coortes , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Prognóstico , Receptores CXCR4/genética , Resultado do TratamentoRESUMO
Telomere dysfunction and fusion can drive genomic instability and clonal evolution in human tumours, including breast cancer. Telomere length is a critical determinant of telomere function and has been evaluated as a prognostic marker in several tumour types, but it has yet to be used in the clinical setting. Here we show that high-resolution telomere length analysis, together with a specific telomere fusion threshold, is highly prognostic for overall survival in a cohort of patients diagnosed with invasive ductal carcinoma of the breast (n = 120). The telomere fusion threshold defined a small subset of patients with an extremely poor clinical outcome, with a median survival of less than 12 months (HR = 21.4 (7.9-57.6), P < 0.0001). Furthermore, this telomere length threshold was independent of ER, PGR, HER2 status, NPI, or grade and was the dominant variable in multivariate analysis. We conclude that the fusogenic telomere length threshold provides a powerful, independent prognostic marker with clinical utility in breast cancer. Larger prospective studies are now required to determine the optimal way to incorporate high-resolution telomere length analysis into multivariate prognostic algorithms for patients diagnosed with breast cancer.
Assuntos
Neoplasias da Mama/metabolismo , Neoplasias da Mama/mortalidade , Homeostase do Telômero , Telômero/metabolismo , Adulto , Idoso , Idoso de 80 Anos ou mais , Biomarcadores Tumorais , Neoplasias da Mama/genética , Neoplasias da Mama/patologia , Intervalo Livre de Doença , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Taxa de Sobrevida , Telômero/genéticaRESUMO
The ecto-enzyme CD38 is gaining momentum as a novel therapeutic target for patients with hematological malignancies, with several anti-CD38 monoclonal antibodies in clinical trials with promising results. In chronic lymphocytic leukemia (CLL) CD38 is a marker of unfavorable prognosis and a central factor in the pathogenetic network underlying the disease: activation of CD38 regulates genetic pathways involved in proliferation and movement. Here we show that CD38 is enzymatically active in primary CLL cells and that its forced expression increases disease aggressiveness in a xenograft model. The effect is completely lost when using an enzyme-deficient version of CD38 with a single amino-acid mutation. Through the enzymatic conversion of NAD into ADPR (ADP-ribose) and cADPR (cyclic ADP-ribose), CD38 increases cytoplasmic Ca(2+) concentrations, positively influencing proliferation and signaling mediated via chemokine receptors or integrins. Consistently, inhibition of the enzymatic activities of CD38 using the flavonoid kuromanin blocks CLL chemotaxis, adhesion and in vivo homing. In a short-term xenograft model using primary cells, kuromanin treatment traps CLL cells in the blood, thereby increasing responses to chemotherapy. These results suggest that monoclonal antibodies that block the enzymatic activities of CD38 or enzyme inhibitors may prove therapeutically useful.
Assuntos
ADP-Ribosil Ciclase 1/genética , ADP-Ribosil Ciclase 1/metabolismo , Leucemia Linfocítica Crônica de Células B/metabolismo , Leucemia Linfocítica Crônica de Células B/terapia , Animais , Antocianinas/farmacologia , Anticorpos Monoclonais/farmacologia , Cálcio/metabolismo , Adesão Celular , Movimento Celular , Proliferação de Células , Quimiotaxia , Flavonoides/farmacologia , Perfilação da Expressão Gênica , Glucosídeos/farmacologia , Humanos , Integrinas/metabolismo , Masculino , Microdomínios da Membrana , Camundongos , Camundongos Endogâmicos NOD , Camundongos SCID , Camundongos Transgênicos , Microscopia de Fluorescência , Mutação , Transplante de Neoplasias , Molécula-1 de Adesão Celular Endotelial a Plaquetas/metabolismo , Prognóstico , Ligação Proteica , Receptores de Quimiocinas/metabolismo , Transdução de SinaisRESUMO
OBJECTIVE: Dysthymia is generally believed to be associated with a high rate of DSM-III-R axis II comorbidity. However, it is unclear whether this rate is higher than that for other axis I disorders, how many dysthymic patients have personality disorders, and what the most common co-occurring axis II conditions are. METHOD: Ninety-seven outpatients with early-on-set dysthymia and 45 with episodic major depression were administered structured diagnostic interviews for axis I and II disorders. In addition, knowledgeable informants were independently interviewed about axis II conditions in the patients. RESULTS: A significantly greater proportion of dysthymic patients (60%) than patients with episodic major depression (18%) met criteria for a personality disorder. The most common axis II conditions among dysthymic patients were borderline, histrionic, and avoidant personality disorder. Informants' reports yielded similar results. CONCLUSIONS: These data indicate that early-onset dysthymia is associated with significantly greater axis II comorbidity than episodic major depression. Further work is necessary to elucidate the processes underlying this association.
Assuntos
Transtorno Depressivo/epidemiologia , Transtornos da Personalidade/epidemiologia , Adulto , Idade de Início , Transtorno da Personalidade Borderline/diagnóstico , Transtorno da Personalidade Borderline/epidemiologia , Comorbidade , Transtorno Depressivo/diagnóstico , Feminino , Transtorno da Personalidade Histriônica/diagnóstico , Transtorno da Personalidade Histriônica/epidemiologia , Humanos , Masculino , Modelos Psicológicos , Determinação da Personalidade , Transtornos da Personalidade/diagnóstico , Prevalência , Escalas de Graduação Psiquiátrica , Recidiva , Projetos de PesquisaRESUMO
OBJECTIVE: A number of studies have documented significant comorbidity between dysthymia and axis II personality disorders, particularly those grouped in cluster B. However, the nature of this comorbidity is poorly understood. The purpose of this investigation was to use the family study method to test five competing models of the comorbidity between early-onset dysthymia and cluster B personality disorders. METHOD: Proband groups consisted of subjects with early-onset dysthymia and a co-occurring cluster B personality disorder (N = 28), subjects with early-onset dysthymia without a cluster B personality disorder (N = 69), and a comparison group of subjects who had never been psychiatrically ill (N = 45). The groups were compared on rates of dysthymia with a cluster B personality disorder, dysthymia without a cluster B personality disorder, and cluster B personality disorders without dysthymia in their first-degree relatives (N = 675). RESULTS: The relatives of both subgroups of dysthymic probands exhibited higher rates of dysthymia with a cluster B personality disorder, dysthymia without a cluster B personality disorder, and cluster B personality disorders without dysthymia than the relatives of the never ill probands. In addition, the relatives of probands with comorbid dysthymia exhibited higher rates of cluster B personality disorders without dysthymia than the relatives of probands with noncomorbid dysthymia. CONCLUSIONS: This pattern of results is consistent with the notion that dysthymia and cluster B personality disorders co-occur because of shared etiological factors. This was the only one of five models of the comorbidity between dysthymia and cluster B personality disorders that was supported by the family data.
Assuntos
Transtorno Depressivo/epidemiologia , Família , Transtornos da Personalidade/epidemiologia , Adolescente , Adulto , Fatores Etários , Idade de Início , Comorbidade , Transtorno Depressivo/diagnóstico , Transtorno Depressivo/etiologia , Feminino , Humanos , Masculino , Modelos Estatísticos , Transtornos da Personalidade/diagnóstico , Transtornos da Personalidade/etiologia , Prevalência , Escalas de Graduação Psiquiátrica , Fatores de RiscoAssuntos
Dissecção Aórtica/etiologia , Hipertensão Pulmonar/complicações , Artéria Pulmonar , Doença Cardiopulmonar/complicações , Dissecção Aórtica/diagnóstico por imagem , Doença Crônica , Feminino , Humanos , Hipertensão Pulmonar/patologia , Obesidade Mórbida/complicações , Artéria Pulmonar/diagnóstico por imagem , Doença Cardiopulmonar/diagnóstico por imagem , Tomografia Computadorizada por Raios XRESUMO
1. The effects of intravenous morphine on the firing of single sensory neurones in the thalamus of the anaesthetized rat are described. 2. Low doses (0.38 to 2.00 mg/kg) of morphine depressed the excitation of nucleus lateralis neurones produced by natural noxious stimuli but were without effect on spontaneous activity. The excitation of some of these neurones by iontophoretically applied acetylcholine or glutamate was also depressed by morphine. These effects were reversed by intravenous (0.25 to 1.17 mg/kg) but not iontophoretically applied (50 to 200 nA) naloxone. 3. Similar or higher doses of morphine (0.58 to 5.07 mg/kg) did not prevent the excitation of ventrobasal thalamic neurones by non-noxious stimuli. 4. The possibility of a direct action of intravenous morphine in the thalamus is discussed.
Assuntos
Morfina/farmacologia , Neurônios/efeitos dos fármacos , Dor/fisiopatologia , Tálamo/efeitos dos fármacos , Animais , Glutamatos/farmacologia , Masculino , Ratos , Tálamo/citologia , Fatores de TempoRESUMO
Chlorambucil and other cytotoxic drugs kill cells, non-selectively, by inducing apoptosis. In this study, we measured the apoptotic response to chlorambucil in T- and B-cells from untreated B-CLL patients and T-cells, from normal control subjects. We found increased chemosensitivity in the T-cells of B-CLL patients compared to the controls (P=0.0002). The chlorambucil ID(50) values for T-cells from B-CLL patients showed a direct correlation with Bcl-2 expression (P=0.002) and an inverse correlation with CD3 cell count (P<0.0001), suggesting a trend of increasing chemosensitivity and decreasing Bcl-2 expression with an elevated T-cell count. There was no differential expression of Bcl-2 or Bax between the CD4(+) and CD8(+) cells of B-CLL patients, isolated by immunomagnetic separation. We found correlations in the leukaemic B-cells between chlorambucil ID(50) values and both Bcl-2 expression (P=0.006), and Bcl-2/Bax ratios (P=0.002), suggesting a role for the Bcl-2/Bax ratio in predicting the response of untreated CLL patients to cytotoxic treatment. Chlorambucil produced almost identical changes in Bcl-2 and Bax expression in normal T-cells and leukaemic B-cells triggered to die by apoptosis, which together with the correlation between Bcl-2 and chemosensitivity confirms a pivotal role for Bcl-2 in regulating a distal step in the apoptotic pathway following cytotoxic cellular damage.
Assuntos
Antineoplásicos Alquilantes/farmacologia , Apoptose/efeitos dos fármacos , Linfócitos B/efeitos dos fármacos , Clorambucila/farmacologia , Leucemia Linfocítica Crônica de Células B/tratamento farmacológico , Proteínas Proto-Oncogênicas c-bcl-2/análise , Proteínas Proto-Oncogênicas/análise , Linfócitos T/efeitos dos fármacos , Linfócitos B/fisiologia , Células Cultivadas , Humanos , Leucemia Linfocítica Crônica de Células B/metabolismo , Leucemia Linfocítica Crônica de Células B/patologia , Linfócitos T/fisiologia , Proteína X Associada a bcl-2RESUMO
Chlorambucil-induced apoptosis was assessed by three different flow cytometric methods in B-cell chronic lymphocytic leukaemia (B-CLL) cells cultured in vitro and the results were compared with those derived from the morphological assessment of the same samples. Spontaneous apoptosis was consistently observed in the control cultures in the absence of drug but this accounted for less than 12% of all cells in every case. The methods under investigation were the Annexin V labelling assay, the terminal deoxynucleotidyl transferase (TdT) end-labelling assay and the labelling of a 38 kDa mitochondrial membrane protein (7A6 antigen) which is exposed on cells undergoing apoptotic cell death (Apo2.7 assay). The Annexin V assay consistently stained a higher percentage of cells and with a greater separation between the positive and negative cell populations. We conclude that the phosphatidyl serine translocation to the outer leaflet of the cell membrane following an apoptotic signal, as labelled by Annexin V, probably occurs before the development of the DNA strand breaks or the exposure of 7A6 antigen in those cells triggered to die by apoptosis.
Assuntos
Apoptose/genética , Apoptose/fisiologia , Citometria de Fluxo/métodos , Anexina A5/análise , Permeabilidade da Membrana Celular , Corantes , Estudos de Avaliação como Assunto , Técnicas Genéticas , Humanos , Dose Letal Mediana , Leucemia Linfocítica Crônica de Células B/patologia , Propídio/análiseRESUMO
B-cell chronic lymphocytic leukaemia (B-CLL) is an incurable clonal disease which shows initial responsiveness to a number of chemotherapeutic drugs. However, most treated patients become resistant to treatment and this represents a major problem in the successful management of the condition. Experimental evidence points to the fact that most chemotherapeutic drugs ultimately exert their cell killing effect through the process of apoptosis. In this study we compared the apoptotic responses of B-CLL cells in vitro following exposure to several chemotherapeutic drugs. We found that there was a correlation between ID50 values for all the drugs under investigation; particularly between Chlorambucil and Fludarabine (P = 0.0002). In addition, we analysed the expression of Bcl-2 and Bax, two proteins pivotal to the regulation of apoptosis, both immediately ex vivo and in viable and apoptotic sub-populations following exposure to drug. Our data suggest that high Bcl-2/Bax ratios may be predictive of a drug resistant phenotype in B-CLL cells and that modulation of these proteins is essential for the induction of cell death. Furthermore, it seems likely that the superior potency that has been ascribed to Fludarabine is due to it being administered in a more optimised dose. A recently reported clinical trial of Fludarabine against high-dose Chlorambucil supports this view since it showed that both treatment modalities were comparable in terms of response rate and survival times.
Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Resistencia a Medicamentos Antineoplásicos/genética , Leucemia Linfocítica Crônica de Células B/tratamento farmacológico , Proteínas Proto-Oncogênicas c-bcl-2/genética , Protocolos de Quimioterapia Combinada Antineoplásica/farmacologia , Apoptose/efeitos dos fármacos , Clorambucila/administração & dosagem , Clorambucila/farmacologia , Doxorrubicina/administração & dosagem , Doxorrubicina/farmacologia , Etoposídeo/administração & dosagem , Etoposídeo/farmacologia , Humanos , Leucemia Linfocítica Crônica de Células B/genética , Leucemia Linfocítica Crônica de Células B/patologia , Vidarabina/administração & dosagem , Vidarabina/análogos & derivados , Vidarabina/farmacologiaRESUMO
The activity of single thalamic nociceptive neurones was recorded extracellularly. BW 180C, (D-ala2,D-leu5-enkephalin) applied locally, by iontophoresis (10--40 nA) or systemically by i.v. injection (1.5--6 mg/kg) markedly depressed the evoked excitation of these neurones following peripheral noxious stimulation. This effect could be antagonised by naloxone. Enhanced enzymic stability did not appear to prolong the duration of action of BW 180C iontrophoretically applied to these neurones.
Assuntos
Endorfinas/farmacologia , Encefalinas/farmacologia , Neurônios/efeitos dos fármacos , Dor/fisiopatologia , Tálamo/efeitos dos fármacos , Animais , Depressão Química , Potenciais Evocados/efeitos dos fármacos , Masculino , Ratos , Tálamo/citologiaRESUMO
We investigated the relationship between drug resistance and Bcl-2/Bax in B-cell chronic lymphocytic leukaemia (B-CLL). Apoptosis was induced in vitro with chlorambucil and cell death was monitored by dual-labelled FACS analysis using Annexin V and propidium iodide. Bcl-2 and Bax protein expression was quantified using FACS and a correlation between drug-induced apoptosis and Bcl-2/Bax was established. Cells were then sorted into viable and nonviable populations according to their forward and side-scatter characteristics and re-analysed for Bcl-2/Bax. The most resistant cells had elevated Bcl-2 levels and low Bax expression. Furthermore, those cells which were undergoing apoptosis showed only a marginal reduction in Bcl-2 expression, but significantly elevated Bax expression following exposure to chlorambucil. The Bcl-2/Bax was significantly greater in the cell fractions resistant to chlorambucil-induced apoptosis. This observation further supports the suggestion that Bax is the pivotal protein in determining the fate of cells following apoptotic signals.