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1.
East Asian Arch Psychiatry ; 34(2): 23-28, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38955787

RESUMO

BACKGROUND: There is evidence suggesting that autistic traits are associated with schizotypal traits. This study examined the factor structure of the Autism Spectrum Quotient 10 (AQ-10) and its associations with schizotypal traits (measured by the Schizotypal Personality Questionnaire-Brief [SPQ-B]) in a cohort of Chinese adolescents and young adults. METHODS: Invitation letters, stratified by locations and housing types, were randomly sent to individuals aged 15 to 24 years for participation. Assessments were made using face-to-face or online interviews. Autistic traits were assessed using the Chinese version of the AQ-10. Schizotypal personality traits were assessed using the Chinese version of the 22-item SPQ-B. RESULTS: In total, 395 male and 536 female participants (mean age, 19.93 years) were recruited between July 2020 and May 2021. Exploratory factor analysis of the AQ-10 yielded three factors (theory of mind, task switching, and attention deficits) explaining 55.11% of the total variance. Autistic traits were positively correlated with schizotypal traits of disorganised features (r = 0.21, p < 0.001), interpersonal relationship deficits (r = 0.19, p < 0.001), and cognitive-perceptual deficits (r = 0.11, p = 0.001). CONCLUSION: In Chinese adolescents and young adults, autistic traits, especially task switching and attention deficits (compared with theory of mind) are more closely correlated with schizotypal personality traits. Disentangling the overlapping and diametrical structure of autistic traits and schizotypal traits may help understand their aetiologies, assessment, and interventions.


Assuntos
Transtorno do Espectro Autista , Transtorno da Personalidade Esquizotípica , Humanos , Masculino , Feminino , Adolescente , Adulto Jovem , Transtorno da Personalidade Esquizotípica/psicologia , Transtorno do Espectro Autista/psicologia , Hong Kong , Análise Fatorial , Inquéritos e Questionários , Adulto , Teoria da Mente , Escalas de Graduação Psiquiátrica
2.
East Asian Arch Psychiatry ; 33(1): 21-27, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-36991552

RESUMO

INTRODUCTION: This study aims to investigate depressive symptoms and its association with resilience, pessimistic bias of COVID-19, lifestyle changes, and family conflicts among undergraduates in a Hong Kong university. METHODS: 1020 undergraduates in The University of Hong Kong completed the online survey between May and August 2020. Severity of depressive symptoms was assessed using the Patient Health Questionnaire-9. Resilience was assessed using the Connor-Davidson Resilience Scale. Pessimistic bias was assessed using two questions on the perceived risks of contracting COVID-19 and of dying from COVID-19. Changes in lifestyles and the presence of family conflicts were measured. Multivariable and mediation analyses were performed to examine association of depressive symptoms with other variables. RESULTS: 61.7% of the respondents reported having mild to severe depressive symptoms. 18.5% of the variance in depressive symptoms was explained by resilience, pessimistic bias, changes in the frequency of sleep, studying at home, and family conflict. Pessimistic bias partially mediated the association between resilience and depressive symptoms. CONCLUSION: The proportion of undergraduates with mild to severe depressive symptoms during the pandemic was high. Measures to reduce family conflict, maintain healthy daily habits, adjust pessimistic bias, and enhance resilience may help to improve the mental well-being of undergraduates during the pandemic.


Assuntos
COVID-19 , Resiliência Psicológica , Humanos , COVID-19/epidemiologia , Depressão/epidemiologia , Pandemias , Hong Kong/epidemiologia
3.
East Asian Arch Psychiatry ; 31(3): 55-66, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34588315

RESUMO

OBJECTIVE: We aim to provide an up-to-date systematic review and meta-analysis of the effects of cognitive stimulation (CS) on cognition, depressive symptoms, and quality of life in persons with dementia. Factors affecting the treatment effect were examined. METHODS: A literature search was performed on databases of MEDLINE, EMBASE, PsycINFO, CINAHL Plus, and Cochrane Library up to 7 March 2019. Only randomised controlled trials investigating the effects of CS in persons with dementia were included. The outcome measures were cognitive function, depressive symptoms, and quality of life. RESULTS: 20 randomised controlled trials with a total of 1251 participants (intervention group: 674; control group: 577) were included for meta-analysis. Most participants had mild to moderate dementia. CS had a significant positive small-to-moderate effect on cognition (Hedges's g = 0.313, p < 0.001). Heterogeneity of CS was low to moderate (Q=30.5854, df=19, p < 0.05, I2 = 37.877%). Inconclusive results were found for depressive symptoms and quality of life. CONCLUSION: CS has a significant positive effect on cognitive function, but its effect on depressive symptoms and quality of life was inconclusive. Future studies with more robust methodology establishing evidence of its efficacy are required.


Assuntos
Cognição , Demência/psicologia , Demência/terapia , Demência/complicações , Depressão/complicações , Depressão/psicologia , Humanos , Qualidade de Vida
4.
J Intellect Disabil Res ; 63(8): 936-946, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-30775821

RESUMO

BACKGROUND: While accelerated ageing is recognised among individuals with Down syndrome (DS), the trajectory of their bone health across adulthood remains poorly understood. METHODS: This study aimed to determine the age-related loss of bone mineral density (BMD) of the lumbar spine in 128 adults with DS aged 18 to 54 years compared with 723 counterparts without DS. RESULTS: Men and women with DS had lower level of BMD than counterparts without DS across age groups. Magnitude of decrement in BMD as reflected in the z-scores was similar between younger and older men with DS. Older women with DS, on the contrary, showed greater decrement in older ages especially in their fourth decade of life. Osteopenia and osteoporosis as defined using age-specific and gender-specific T-scores affected greater number of men with DS (38% and 25%) than women (17% and 17%) aged 40-49 years. CONCLUSIONS: Findings supported adults with DS, especially men, to have early bone mineral testing.


Assuntos
Senilidade Prematura/diagnóstico por imagem , Densidade Óssea , Doenças Ósseas Metabólicas/diagnóstico por imagem , Síndrome de Down/diagnóstico por imagem , Absorciometria de Fóton , Adolescente , Adulto , Senilidade Prematura/complicações , Doenças Ósseas Metabólicas/etiologia , Síndrome de Down/complicações , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Osteoporose/diagnóstico por imagem , Osteoporose/etiologia , Fatores Sexuais , Adulto Jovem
7.
Open Dent J ; 9: 21-30, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25674168

RESUMO

AIM: To study the oral health status of Chinese children and adolescents undergoing chemotherapy in Hong Kong. METHOD: All Chinese children and adolescent oncology patients aged 18 or below attending the Children's Centre for Cancer and Blood Disease at a hospital for chemotherapy were invited and parental consent was sought before they were accepted into the study. The study comprised of 1) a parental questionnaire, 2) the collection of medical history and 3) a clinical examination for tooth decay (caries) and mucosal status. RESULTS: A total of 69 patients were invited, and they all participated in this study. Their mean age was 9.2±5.0 and 44 (64%) were males. Twenty-six patients (38%) had no caries experience (DMFT and/or dmft = 0). Higher caries experience was detected in participants that were not born in Hong Kong, had completed active chemotherapy, participated in school dental care service and whose parents had low educational levels. There were 41 patients with active chemotherapy, 24 of whom were diagnosed with acute leukaemia, 5 with haematological malignancies other than leukaemia and 11 with solid tumours. Antimetabolites, cytotoxic antibiotics, alkylating agents and plant alkaloids were administered in 49%, 32%, 24% and 22% of them, respectively. Twenty-six (63%) patients showed no mucosal complications. The most common oral complication was oral mucositis (24%) followed by petechiae (10%). CONCLUSION: About two-thirds of paediatric and adolescent cancer patients had caries experience, which was more common among those who had completed chemotherapy. Oral mucositis followed by petechiae were the two most common complications of receiving chemotherapy.

8.
Psychol Med ; 43(9): 1883-93, 2013 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-23217676

RESUMO

BACKGROUND: Cognitive impairment is a core feature of schizophrenia. Its relationship with duration of untreated psychosis (DUP), a potentially malleable prognostic factor, has been less studied, with inconsistent findings being observed in the literature. Previous research investigating such a relationship was mostly cross-sectional and none of those prospective studies had a follow-up duration beyond 2 years. Method A total of 93 Hong Kong Chinese aged 18 to 55 years presenting with first-episode schizophrenia-spectrum disorder were studied. DUP and pre-morbid adjustment were measured using a structured interview incorporating multiple sources of information. Psychopathological evaluation was administered at intake, after clinical stabilization of the first psychotic episode, and at 12, 24 and 36 months. Cognitive functions were measured at clinical stabilization, and at 12, 24 and 36 months. RESULTS: DUP exerted differential effects on various cognitive domains, with memory deficits being the most related to DUP even when potential confounders including pre-morbid adjustment and sex were adjusted. Prolonged DUP was associated with more severe impairment in visual memory at clinical stabilization and verbal memory at 24 and 36 months. Further, patients with a long DUP were found to have worse outcomes on negative symptoms at 36 months. The effects of DUP on verbal memory remained significant even when negative symptoms were taken into consideration. CONCLUSIONS: Our findings provided further supportive evidence that delayed treatment to first-episode psychosis is associated with poorer cognitive and clinical outcomes. In addition, DUP may specifically affect memory function and its adverse impact on verbal memory may only become evident at a later stage of the recovery process.


Assuntos
Antipsicóticos/uso terapêutico , Transtornos Cognitivos/tratamento farmacológico , Transtornos Psicóticos/tratamento farmacológico , Esquizofrenia/tratamento farmacológico , Psicologia do Esquizofrênico , Tempo para o Tratamento , Adolescente , Adulto , Transtornos Cognitivos/psicologia , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Testes Neuropsicológicos , Prognóstico , Estudos Prospectivos , Transtornos Psicóticos/psicologia , Fatores de Tempo , Adulto Jovem
10.
East Asian Arch Psychiatry ; 22(3): 100-4, 2012 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-23019282

RESUMO

The year 2011 marked the 10-year milestone of early intervention for psychosis in Hong Kong. Since 2001, the landscape of early psychosis services has changed markedly in Hong Kong. Substantial progress has been made in the areas of early intervention service implementation, knowledge generation, and public awareness promotion. Favourable outcomes attributable to the early intervention service are supported by solid evidence from local clinical research studies; early intervention service users showed improved functioning, ameliorated symptoms, and decreased hospitalisation and suicide rates. Continued development of early intervention in Hong Kong over the decade includes the introduction and maturation of several key platforms, such as the Hospital Authority Early Assessment Service for Young People with Psychosis programme, the Psychosis Studies and Intervention Unit by the University of Hong Kong, the Hong Kong Early Psychosis Intervention Society, the Jockey Club Early Psychosis Project, and the postgraduate Psychological Medicine (Psychosis Studies) programme. In this paper, we reviewed some of the major milestones in local service development with reference to features of the Hong Kong mental health system. We describe chronologically the implementation and consolidation of public early intervention services as well as recent progresses in public awareness work that are tied in with knowledge generation and transfer, and outline the prospects for early intervention in the next decade and those that follow.


Assuntos
Intervenção Médica Precoce/tendências , Serviços de Saúde Mental/tendências , Desenvolvimento de Programas , Transtornos Psicóticos/terapia , Intervenção Médica Precoce/métodos , Educação em Saúde/métodos , Hong Kong , Humanos , Estereotipagem
11.
East Asian Arch Psychiatry ; 20(4): 174-9, 2010 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-22348926

RESUMO

OBJECTIVE: To examine the spontaneous blink rate over a 3-year period and its clinical and cognitive correlates among patients with first-episode schizophrenia. METHODS: This study prospectively followed 93 patients with first-episode schizophrenia, schizophreniform and schizoaffective disorders for 3 years. Patients were longitudinally assessed for blink rate, their positive and negative symptoms, and a range of cognitive features including verbal fluency, verbal memory, visual memory, and the Wisconsin Card Sorting Test performance. RESULTS. When compared with a matched control group, there was a significantly higher blink rate at their 3-year follow-up but not at initial presentation. The increase in blink rate over time correlated positively with the number of relapses. It also correlated with logical memory, verbal fluency, categories completed, and perseverative errors in the Wisconsin Card Sorting Test. The increased blink rate also correlated with pre-morbid schizoid and schizotypal traits. All these correlations were statistically significant. CONCLUSION: The change in the blink rate over time may reflect underlying involvement of the dopaminergic system in mediating relapse and cognitive functions.

13.
Biochem Biophys Res Commun ; 274(3): 641-8, 2000 Aug 11.
Artigo em Inglês | MEDLINE | ID: mdl-10924331

RESUMO

Human MnSOD localizes to the mitochondria and plays a key protective role by detoxifying oxygen free radicals. The MnSOD mRNA 3' UTR contains a 280-bp region (Alu-like element or Alu-E) that shows high homology to human Alu and 7SL sequences. MnSOD 3' UTR probes hybridize to a specific cytoplasmic RNA species of approximately 300 nucleotides. This antisense RNA is most likely 7SL RNA based on its size, ubiquitousness, high levels, and lack of inducibility. Hybridization of this small RNA to the MnSOD 3' UTR may modulate posttranscriptional MnSOD gene expression. This regulation could occur by several means including inhibition of translation and mRNA destabilization. Regulation at the level of translational initiation does not seem to occur as MnSOD mRNA containing the Alu-E is efficiently bound by ribosomes. To test the role of the MnSOD 3' UTR, and in particular the Alu-E in gene expression, luciferase reporter gene constructs were made containing various regions of the MnSOD 3' UTR including the Alu-E. These constructs were transfected into human A549 lung carcinoma cells and luciferase activity was measured. Reporter constructs containing the MnSOD 3' UTR and the Alu-E repress luciferase activity. Taken together, these results suggest that naturally occurring antisense RNA may bind MnSOD mRNA and repress its expression. These results also suggest that other mRNAs containing Alu elements may be similarly repressed.


Assuntos
Regulação Enzimológica da Expressão Gênica , RNA Citoplasmático Pequeno/genética , Superóxido Dismutase/genética , Regiões 3' não Traduzidas/genética , Sequência de Bases , Humanos , Dados de Sequência Molecular , RNA Antissenso , RNA Mensageiro/genética
14.
J Biol Chem ; 274(19): 12955-8, 1999 May 07.
Artigo em Inglês | MEDLINE | ID: mdl-10224040

RESUMO

The nematode CED-4 protein and its human homolog Apaf-1 play a central role in apoptosis by functioning as direct activators of death-inducing caspases. A novel human CED-4/Apaf-1 family member called CARD4 was identified that has a domain structure strikingly similar to the cytoplasmic, receptor-like proteins that mediate disease resistance in plants. CARD4 interacted with the serine-threonine kinase RICK and potently induced NF-kappaB activity through TRAF-6 and NIK signaling molecules. In addition, coexpression of CARD4 augmented caspase-9-induced apoptosis. Thus, CARD4 coordinates downstream NF-kappaB and apoptotic signaling pathways and may be a component of the host innate immune response.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal , Apoptose , Proteínas de Caenorhabditis elegans , Proteínas de Ligação ao Cálcio/metabolismo , Proteínas de Transporte/metabolismo , Proteínas de Helminto/metabolismo , NF-kappa B/metabolismo , Proteínas/metabolismo , Sequência de Aminoácidos , Fator Apoptótico 1 Ativador de Proteases , Sequência de Bases , Proteínas de Transporte/genética , DNA Complementar , Humanos , Dados de Sequência Molecular , Proteína Adaptadora de Sinalização NOD1 , Homologia de Sequência de Aminoácidos , Transdução de Sinais
15.
Antiviral Res ; 36(1): 1-9, 1997 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-9330756

RESUMO

Age-dependent poliomyelitis (ADPM) is a neuroparolytic disease which results from combined infection of susceptible mice with lactate dehydrogenase-elevating virus (LDV) and murine leukemia virus (MuLV). The present study examined the effects of interferon-gamma (IFN-gamma) treatment on the incidence of ADPM, replication of LDV and MuLV and anti-LDV immunity. IFN-gamma treatment of ADPM-susceptible C58/M mice protected them from paralytic disease, but had no detectable effect on the IgG anti-LDV response or LDV viremia. IFN-gamma-mediated protection from ADPM correlated with reduced expression of LDV RNA, but not MuLV RNA, in the spinal cords of C58/M mice. These results confirm that spinal cord LDV replication is the determinant of ADPM and demonstrate that cytokine-mediated inhibition of LDV replication in the central nervous system prevents neuroparalytic disease.


Assuntos
Envelhecimento/patologia , Interferon gama/farmacologia , Vírus Elevador do Lactato Desidrogenase/efeitos dos fármacos , Vírus da Leucemia Murina/efeitos dos fármacos , Poliomielite/prevenção & controle , Animais , Formação de Anticorpos , Predisposição Genética para Doença , Imunoglobulina G/biossíntese , Vírus Elevador do Lactato Desidrogenase/imunologia , Vírus Elevador do Lactato Desidrogenase/isolamento & purificação , Camundongos , Camundongos Mutantes , RNA Viral/genética , Medula Espinal/virologia
16.
Neurochem Int ; 29(2): 197-203, 1996 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-8837049

RESUMO

The potential benefits of tumor necrosis factor pretreatment in promoting motor functional recovery of peripheral nerve following low load crush injury were examined. Using a specially designed crush device, rat sciatic nerve was subjected to a low load crush injury of 2-h duration. Recombinant murine tumor necrosis factor and saline were intraperitoneally injected into the experimental and control animals, respectively, prior to nerve crushing. Subsequent motor function was evaluated at intervals by measurement of the sciatic functional index. There was significantly (P < 0.05 to < 0.01) more rapid recovery in the tumor necrosis factor pretreated group as compared to the controls between day 14 and day 28. The sciatic functional index in the tumor necrosis factor group improved to -69.3 +/- 5.3 at day 14 and to nearly normal at day 21. In contrast, the sciatic functional index in the control group was -95.5 +/- 3.1% at day 14 and did not approach normal until day 42. Histological results paralleled the functional findings. The results suggest that tumor necrosis factor pretreatment has the potential to attenuate neurostructural damage and promote motor functional recovery in rat peripheral nerve.


Assuntos
Compressão Nervosa , Regeneração Nervosa , Nervo Isquiático/fisiologia , Fator de Necrose Tumoral alfa/farmacologia , Animais , Axônios/ultraestrutura , Masculino , Camundongos , Bainha de Mielina/ultraestrutura , Degeneração Neural , Ratos , Ratos Sprague-Dawley , Proteínas Recombinantes/farmacologia , Nervo Isquiático/ultraestrutura
17.
Virus Res ; 41(2): 153-61, 1996 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-8738174

RESUMO

Placental and fetal infections with lactate dehydrogenase-elevating virus (LDV) were determined by virus titration, indirect fluorescence antibody (IFA), and in situ hybridization with cDNA probes. Experiments were designed to determine the effects of gestational age, timing of maternal LDV infection, and immunological (antibody and cytokine) factors on mouse placental and fetal LDV infection. Virus infection of the placenta was detected at high levels (almost all placentas infected) within 24 h post-maternal infection (p.m.i.), whereas fetal LDV infection was detected only at a low level by 24 h p.m.i. The percentage of fetuses becoming LDV infected progressively increased between 24 and 72 h p.m.i. When fetal infection was studied at 72 h p.m.i., earlier gestational ages (9-11 days) were associated with fetal resistance to infection, whereas between 12.5 and 15 days of gestation, virus infection was detected in 50-71% of fetuses. Maternal treatment with interferon-gamma (IFN-gamma) or anti-LDV monoclonal antibodies was associated with reduced rates of fetal, but not placental, LDV infection. These results demonstrate that both developmental and immunological factors are important in the regulation of transplacental LDV infection.


Assuntos
Infecções por Arterivirus/virologia , Feto/virologia , Vírus Elevador do Lactato Desidrogenase/isolamento & purificação , Placenta/virologia , Animais , Anticorpos Monoclonais/farmacologia , Anticorpos Antivirais/imunologia , Anticorpos Antivirais/farmacologia , Antivirais/farmacologia , Infecções por Arterivirus/patologia , Infecções por Arterivirus/prevenção & controle , Feminino , Feto/patologia , Técnica Indireta de Fluorescência para Anticorpo , Idade Gestacional , Transmissão Vertical de Doenças Infecciosas , Interferon gama/farmacologia , Vírus Elevador do Lactato Desidrogenase/genética , Vírus Elevador do Lactato Desidrogenase/imunologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos ICR , Placenta/patologia , Gravidez , Fatores de Tempo
18.
J Cell Biochem ; 60(1): 56-60, 1996 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-8825416

RESUMO

Tumor necrosis factor (TNF) and lymphotoxin (LT), initially described as tumoricidal proteins, may be useful as adjuncts in cancer therapy. Treatment with TNF or LT was found to protect cells and animals against damage mediated by radiation or cytotoxic anticancer drugs. By contrast, tumor cells treated with TNF or LT were sensitized to these insults. We present a model in which TNF or LT induces both the synthesis of "protective" proteins such as manganous superoxide dismutase (MnSOD) and the activation of "killing" proteins, such as proteases, depending on the level of the inducing signal. Although the p55-TNF/LT receptor is structurally related to the Fas receptor, they can each signal apoptosis by distinct pathways. Furthermore, activation of both receptors acts synergistically in stimulating apoptosis.


Assuntos
Apoptose , Linfotoxina-alfa/uso terapêutico , Neoplasias/terapia , Fator de Necrose Tumoral alfa/uso terapêutico , Animais , Apoptose/efeitos dos fármacos , Apoptose/efeitos da radiação , Indução Enzimática , Proteína Ligante Fas , Humanos , Glicoproteínas de Membrana/imunologia , Neoplasias/patologia , Superóxido Dismutase/biossíntese
19.
Microsurgery ; 17(3): 131-5, 1996.
Artigo em Inglês | MEDLINE | ID: mdl-9016456

RESUMO

The effect of lymphotoxin (LT) on the functional recovery of crushed peripheral nerves was studied. Using a specially designed compression device, a 5 mm segment of the right sciatic nerve of rats was subjected to a 100 g crush load with a 2 hr duration. The rats in the experimental and control groups received two doses of LT (20 micrograms/kg each) or the same volume of saline, respectively, administered intraperitoneously 24 hr and 1 hr before the procedure. Walking track tests and histologic examinations were performed at intervals up to 56 days after the crush. Motor functional recovery in the LT pretreated group started at day 7 while the crushed limb in the control group remained totally dysfunctional. The sciatic functional index improved faster in the LT group than in the control group during the second week after the crush and reached a significant difference (P < 0.05) at day 18. Subsequently, both groups had a similar evolution. Histologic results paralleled the functional findings. In conclusion, LT can promote motor functional recovery of crushed rat peripheral nerve in the early stage of regeneration.


Assuntos
Linfotoxina-alfa/uso terapêutico , Nervo Isquiático/lesões , Análise de Variância , Animais , Axônios/fisiologia , Axônios/ultraestrutura , Injeções Intraperitoneais , Linfotoxina-alfa/administração & dosagem , Masculino , Neurônios Motores/fisiologia , Bainha de Mielina/fisiologia , Bainha de Mielina/ultraestrutura , Regeneração Nervosa , Pré-Medicação , Distribuição Aleatória , Ratos , Ratos Sprague-Dawley , Nervo Isquiático/patologia , Nervo Isquiático/fisiopatologia , Cloreto de Sódio , Caminhada/fisiologia
20.
EXS ; 77: 321-33, 1996.
Artigo em Inglês | MEDLINE | ID: mdl-8856983

RESUMO

Tumor necrosis factor (TNF) and lymphotoxin (LT) are related cytokines produced in response to infection or oxidative insults such as radiation. These cytokines bind to the same receptors and have pleiotropic effects on a variety of cell types. TNF or LT pretreatment, which can induce the synthesis of "protective" proteins such as mitochondrial manganese superoxide dismutase (MnSOD), protects animals from lethal doses of radiation or the chemotherapeutic drug doxorubicin. In contrast, TNF or LT pretreatment of tumor cells, which do not express MnSOD, results in sensitization to these insults. Therefore, radio- or chemoprotection of normal cells may act partially through enhanced expression of MnSOD. On the other hand, tumor sensitization may result from activation of "killing" proteins such as interleukin-1 beta converting enzyme (ICE) or other ICE-like proteases, possibly through TNF/LT-induced oxygen free radicals. In addition to their originally described anti-tumor activity, these cytokines may have new therapeutic indications in protecting normal cells while sensitizing tumor cells to radiation or chemotherapeutic drugs.


Assuntos
Linfotoxina-alfa/farmacologia , Superóxido Dismutase/metabolismo , Fator de Necrose Tumoral alfa/farmacologia , Antioxidantes/metabolismo , Dano ao DNA , Regulação da Expressão Gênica/genética , Humanos , Modelos Biológicos , Estresse Oxidativo/efeitos dos fármacos , Espécies Reativas de Oxigênio/metabolismo
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