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1.
S Afr J Sports Med ; 33(1): v33i1a11211, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-36816894

RESUMO

Background: The Indian Ocean Island Games is a multi-sport event that occurs every four years and includes athletes from seven islands of the Indian Ocean, namely, Comoros, Reunion, Mayotte, Madagascar, Maldives, Seychelles, and Mauritius. Objectives: This study aims to describe the injury and illness epidemiology of the athletes participating during the 2019 Indian Ocean Islands Games. Methods: This prospective cohort study recorded injury and illness cases from athletes who competed in these Games. All medical physicians received detailed instructions and training on data collection using an injury report form. All athletes (minors and adults) who provided consent, or consent given from the minors' guardians, were included in this study. Athletes who did not provide consent for this study were excluded. Results: Athletes (n = 1 521; 531 women and 990 men) reported 160 injuries (injury incidence rate of 11%) and 85 illnesses (illness incidence rate of 6%). The percentage of distribution of injuries were highest in football and basketball. Most injuries occurred during competition, compared with training, joint sprains were the most common type of injury (28%), followed by muscle strains (19%). Men suffered most of the injuries (79% vs. 21% for women). Similarly, men sustained more illnesses than women (57% vs. 43%). Most illnesses affected the respiratory system (67%), and infection was the most common cause of illness (84%) in participating athletes. Conclusion: These findings are similar to previous events in other parts of the world. However, unique ailments, not previously reported on, were discovered. Epidemiological data from this study can be inferred to athletes who compete in similar multi-sport events in the Indian Ocean region.

2.
Arch Gen Psychiatry ; 48(5): 423-7, 1991 May.
Artigo em Inglês | MEDLINE | ID: mdl-1673594

RESUMO

Eighty-one percent of 339 alcoholics participating in a research program were found to have associated mental disorders. Alcoholics with onset of heavy drinking before 20 years of age had significantly more antisocial personality traits, drug abuse, bipolar disorder, panic disorder, suicide attempts, and paternal alcoholism than alcoholics with onset after age 20 years. Alcoholics with onset before and after 20 years of age also differed significantly from each other for cerebrospinal fluid concentrations of diazepam-binding inhibitor and somatostatin. These results support the notion that age of onset may delineate subgroups of alcoholics with significant clinical and neurochemical differences.


Assuntos
Alcoolismo/complicações , Transtornos Mentais/complicações , Neuropeptídeos/líquido cefalorraquidiano , Adulto , Fatores Etários , Alcoolismo/líquido cefalorraquidiano , Alcoolismo/diagnóstico , Transtorno da Personalidade Antissocial/complicações , Transtorno da Personalidade Antissocial/diagnóstico , Transtornos de Ansiedade/complicações , Transtornos de Ansiedade/diagnóstico , Transtorno Bipolar/complicações , Transtorno Bipolar/diagnóstico , Inibidor da Ligação a Diazepam , Feminino , Humanos , Masculino , Transtornos Mentais/diagnóstico , Pânico , Escalas de Graduação Psiquiátrica , Somatostatina/líquido cefalorraquidiano , Transtornos Relacionados ao Uso de Substâncias/complicações , Transtornos Relacionados ao Uso de Substâncias/diagnóstico , Tentativa de Suicídio/estatística & dados numéricos
3.
Sleep ; 5(4): 350-60, 1982.
Artigo em Inglês | MEDLINE | ID: mdl-6761826

RESUMO

Eleven patients suffering from chronic insomnia were given 30 mg flurazepam for 28 nights. While EEG measures of total sleep time and sleep efficiency were improved, changes in sleep latency and intermittent waking time were small and nonsignificant. Subjective benefits in sleep were confined to the first 2 nights. There was neither increased nor decreased daytime sleepiness. Cognitive functioning was significantly decreased during the first 2 days, and patients were unaware of these changes. Simple motor tasks were relatively unaffected. Desalkylflurazepam concentrations showed significant accumulation over time, but were not predictive of sleep measures or daytime performance in individual subjects. The withdrawal period was characterized by subjectively disturbed sleep and daytime dysphoria.


Assuntos
Flurazepam/uso terapêutico , Distúrbios do Início e da Manutenção do Sono/tratamento farmacológico , Ensaios Clínicos como Assunto , Cognição/efeitos dos fármacos , Avaliação de Medicamentos , Eletroencefalografia , Flurazepam/efeitos adversos , Flurazepam/análogos & derivados , Flurazepam/sangue , Humanos , Desempenho Psicomotor/efeitos dos fármacos , Tempo de Reação , Sono/efeitos dos fármacos , Síndrome de Abstinência a Substâncias/etiologia
4.
Psychopharmacology (Berl) ; 78(2): 137-40, 1982.
Artigo em Inglês | MEDLINE | ID: mdl-6817370

RESUMO

The effects of 4 weeks of treatment with the selective monoamine oxidase (MAO) inhibiting antidepressant clorgyline and pargyline on the sleep of affectively disordered patients were studied. Both inhibitors resulted in near total suppression of REM sleep, a decrease in total sleep time, and an increase in the percent of stage 2 sleep. Clorgyline also increased awake time and decreased total recording period and sleep latency. In general, changes were greater for clorgyline than for pargyline and were about 50% slower to return to baseline after clorgyline compared to pargyline discontinuation. The results were consistent with the hypothesis that selective inhibition of the MAO type A, as produced by clorgyline, is sufficient to induce marked sleep changes. MAO inhibitor-induced receptor changes are proposed to account for the time course of the REM suppression and the REM rebound observed upon withdrawal.


Assuntos
Inibidores da Monoaminoxidase/farmacologia , Sono REM/efeitos dos fármacos , Adulto , Clorgilina/farmacologia , Transtorno Depressivo/tratamento farmacológico , Transtorno Depressivo/psicologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Inibidores da Monoaminoxidase/uso terapêutico , Pargilina/farmacologia
5.
Arch Surg ; 121(1): 50-5, 1986 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-3484624

RESUMO

Blood transfusions repeatedly have been shown to prolong allograft survival, probably by stimulating suppressor T lymphocytes. The effects of transfusions on immune function in traumatized patients has not previously been investigated. We investigated the effects of transfusions on the immune system using a burned rat model. The transfusions were found to have no effect on the white blood cell counts, differential cell count, or neutrophil migration and bactericidal index. Those animals that received transfusion did exhibit impaired cell-mediated immunity and macrophage migration. Blood transfusions seem to increase further the immunosuppression seen with trauma and surgery.


Assuntos
Transfusão de Sangue , Queimaduras/imunologia , Animais , Atividade Bactericida do Sangue , Contagem de Células Sanguíneas , Movimento Celular , Ensaio de Unidades Formadoras de Colônias , Imunidade Celular , Macrófagos/imunologia , Masculino , Neutrófilos/imunologia , Ratos , Ratos Endogâmicos Lew , Staphylococcus aureus , Reação Transfusional
6.
Am J Surg ; 179(5): 389-90, 2000 May.
Artigo em Inglês | MEDLINE | ID: mdl-10930487

RESUMO

BACKGROUND: Intraoperative localization of rib abnormalities identified on bone scan can be deceptively difficult. Previously used techniques have had limited sensitivity and accuracy. The gamma probe can help localize these bone scan "hot spots." METHODS: Over the past 17 months, 5 patients underwent gamma-probe-directed limited rib resections following intravenous administration of Tc99m-MDP. Three patients required biopsies for suspected malignancy, and the other 2 underwent therapeutic resections for pain. The device was easy to work with following minimal training. RESULTS: Localization was excellent, limiting the extent of surgery needed. Comparison with rib counting and preoperative bone scan localization showed a discrepancy of up to 13 cm. Sensitivity and accuracy were each 100%. CONCLUSIONS: The gamma probe offers a simple and significant advance in the performance of rib biopsies for nonpalpable lesions.


Assuntos
Biópsia/métodos , Neoplasias Ósseas/diagnóstico por imagem , Fraturas não Consolidadas/diagnóstico por imagem , Câmaras gama , Monitorização Intraoperatória/métodos , Costelas/diagnóstico por imagem , Medronato de Tecnécio Tc 99m , Biópsia/efeitos adversos , Neoplasias Ósseas/cirurgia , Fraturas não Consolidadas/cirurgia , Humanos , Monitorização Intraoperatória/efeitos adversos , Pneumotórax/etiologia , Cintilografia , Reprodutibilidade dos Testes , Costelas/lesões , Costelas/cirurgia , Sensibilidade e Especificidade
7.
Psychiatry Res ; 12(3): 235-50, 1984 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-6593755

RESUMO

Ten insomniacs and matched control subjects, in whom major physiologic disorders such as sleep apnea and nocturnal myoclonus were ruled out, underwent studies of sleep, temperature, motor activity, cognitive performance, and perception of depth of sleep. Subjective descriptions of sleep differed significantly between insomniacs and normals on a variety of variables. In contrast, polysomnographic evaluation showed increased intermittent waking time and decreased sleep efficiency, and only a tendency toward decreased total sleep and increased sleep latency. Minnesota Multiphasic Personality Inventory (MMPI) evaluation revealed that insomniacs had higher scores on the F, D, and SI scales, and lower values on the K scale. On cognitive testing, insomniacs did well on tests of episodic (recent) memory, but displayed major deficits in accessing semantic memory (retrieval of material already known). Compared to normals, insomniacs described rapid eye movement (REM) sleep as relatively "light" sleep.


Assuntos
Distúrbios do Início e da Manutenção do Sono/psicologia , Adulto , Temperatura Corporal , Cognição , Feminino , Humanos , MMPI , Masculino , Atividade Motora , Desempenho Psicomotor , Tempo de Reação , Distúrbios do Início e da Manutenção do Sono/fisiopatologia , Fases do Sono
8.
Psychiatry Res ; 19(4): 267-84, 1986 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-3809325

RESUMO

Ten insomniacs with age- and sex-matched controls had studies of baseline sleep, relation of polygraphically defined sleep to retrospective reports, and arousal thresholds to electronic tones or to a recording of a voice calling out the subject's name. The two groups differed in 10 out of 13 questions about habitual sleep and daytime feelings. In contrast, polygraphic measures of baseline sleep indicated only that insomniacs tended to have slightly less total sleep and had a small but significant increase in early morning awakening time. Unlike the descriptions of habitual sleep, the subjects' retrospective reports of the previous night's sleep differed significantly only for the variable of total sleep time, and there were virtually no differences in the description of their status at a given moment. Auditory arousal thresholds were similar in the two groups, and both went back to sleep and stayed asleep with equal facility. These findings suggest that subjectively poor sleep is not necessarily "light" sleep. For both groups, arousal thresholds differed across the sleep stages, and thresholds to hearing the subject's name were lower than those in response to electronic tones. Although insomniacs had as much polygraphically defined sleep as controls between the forced awakenings of the arousal threshold studies, they perceived their sleep to be only approximately half as long. Insomniacs described themselves as having been awake more frequently than controls in 8 out of 10 forced awakening situations. In one case, insomniacs also overestimated the time between awakenings. In both groups, there was little relationship between reported habitual aspects of sleep and baseline polygraphically defined sleep variables. On questionnaires the following mornings, however, in both groups there was a positive correlation of subjective quality of sleep on the baseline nights with percentage of rapid eye movement sleep, and a negative correlation to various aspects of slow-wave sleep.


Assuntos
Distúrbios do Início e da Manutenção do Sono/fisiopatologia , Adulto , Nível de Alerta/fisiologia , Limiar Auditivo/fisiologia , Cognição , Feminino , Humanos , Masculino , Sono/fisiologia , Distúrbios do Início e da Manutenção do Sono/psicologia , Percepção do Tempo
9.
Psychiatry Res ; 21(2): 89-94, 1987 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-3615694

RESUMO

Eight patients with major depressive disorder (seven bipolar and one unipolar) and matched controls had sleep studies, on which frequency analysis of the electroencephalogram (EEG) was performed. Total sleep and sleep efficiency were decreased in the patients, but there was no significant difference in rapid eye movement (REM) latency between the two groups. Frequency analysis revealed no group differences in power in the delta band (0.23-2.5 Hz) or the whole EEG spectrum (0.23-25 Hz). These findings suggest that mean REM latencies are not always shorter in major depression. The results are discussed in light of a previous report of decreased delta energy in the sleep EEG of unipolar patients.


Assuntos
Transtorno Bipolar/fisiopatologia , Transtorno Depressivo/fisiopatologia , Eletroencefalografia , Sono/fisiologia , Adulto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Tempo de Reação/fisiologia , Fases do Sono/fisiologia
10.
Braz J Med Biol Res ; 27(2): 269-73, 1994 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-7915927

RESUMO

We have previously demonstrated the non-covalent association of the protein tyrosine kinases p56lck and p60fyn together with a number of substrates for phosphorylation with rat thymocyte Thy-1. Here we present evidence that one of these associated phosphoproteins, p85, is associated by disulphide bridging with another polypeptide, demonstrating that it is an integral membrane protein with an extracellular domain. We also show that phosphatidylinositol 3 kinase activity may be coprecipitated with Thy-1 in Brij 96 thymocyte lysates.


Assuntos
Antígenos de Superfície/química , Glicosilfosfatidilinositóis/química , Glicoproteínas de Membrana/química , Fosfoproteínas/química , Proteínas Tirosina Quinases/química , Animais , Antígenos de Superfície/isolamento & purificação , Glicoproteínas de Membrana/isolamento & purificação , Testes de Precipitina , Ratos , Transdução de Sinais , Antígenos Thy-1 , Timo
14.
Immunology ; 81(1): 103-10, 1994 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-8132206

RESUMO

Rat lymphocytes were found to aggregate in response to monoclonal antibodies to the glycosyl phosphatidylinositol (GPI)-anchored surface antigen CD48. This clustering required bivalent antibodies but was not Fc mediated. It was blocked by inhibitors of cellular metabolism and cytoskeletal function but not by antibodies to leucocyte function-associated antigen-1 (LFA-1) or intracellular adhesion molecule-1 (ICAM-1). The clusters were found to be due to homotypic adhesion of B cells, with T cells showing no response despite expressing equal levels of CD48. In addition, thymocytes, which are known to cluster in response to cross-linking of Thy-1, another GPI-anchored molecule, were found not to respond to cross-linking of CD48. These results suggest that specific signalling through CD48 in B cells, but not T cells, and through Thy-1, but not CD48, in thymocytes, lead to cell adhesion events. This differential signalling is interesting as neither CD48 nor Thy-1 have transmembrane or intracellular domains. Levels of CD48-associated protein kinase activity were very low in both B and T cells, and no difference in the susceptibility to cleavage with phosphatidylinositol-specific phospholipase C was detected between B- and T-cell CD48.


Assuntos
Antígenos CD/imunologia , Linfócitos B/imunologia , Linfócitos T/imunologia , Animais , Anticorpos Monoclonais/imunologia , Antígenos CD/efeitos dos fármacos , Linfócitos B/enzimologia , Antígeno CD48 , Adesão Celular/efeitos dos fármacos , Agregação Celular/efeitos dos fármacos , Agregação Celular/imunologia , Células Cultivadas , Fragmentos Fc das Imunoglobulinas/imunologia , Fosfatidilinositol Diacilglicerol-Liase , Fosfoinositídeo Fosfolipase C , Diester Fosfórico Hidrolases/farmacologia , Fosfotransferases/metabolismo , Ratos , Ratos Endogâmicos , Linfócitos T/enzimologia
15.
J Nerv Ment Dis ; 169(4): 261-4, 1981 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-7217935

RESUMO

Sleep EEG and respiratory measures were examined in a 38-year-old man with a long-standing history of insomnia and daytime sleepiness. He was found to have seven to 18 primarily obstructive apneas per night on four baseline recordings, a finding not generally considered to be indicative of pathology. On the first two nights on which he received 30 mg of the benzodiazepine hypnotic flurazepam, there were 22 and 100 apneas, and during the daytime he became extremely sleepy. Upon cessation of medication, his clinical condition improved, and the number of apneas decreased to 11 and 6 on withdrawal nights 4 and 6. Although respiratory depression is neither invariable nor unique to flurazepam, this case suggests that it may be a clinically significant problem with recommended oral doses in some individuals.


Assuntos
Flurazepam/efeitos adversos , Síndromes da Apneia do Sono/induzido quimicamente , Distúrbios do Início e da Manutenção do Sono/tratamento farmacológico , Adulto , Humanos , Masculino , Placebos
16.
Eur J Immunol ; 23(10): 2540-4, 1993 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-8104794

RESUMO

Cell surface glycoproteins anchored to the plasma membrane via glycosylphosphatidylinositol (GPI) structures, and hence having no cytoplasmic domains, can nevertheless transmit activation signals in lymphocytes. By immunoprecipitation from detergent lysates and in vitro immune complex kinase reactions the GPI-anchored molecules Thy-1 and CD48 are shown to be associated with multimolecular complexes of phosphoproteins including the protein tyrosine kinases p56lck and p60fyn in both rat and mouse thymocytes. Moreover, the kinase activity associated with Thy-1 on rat thymocytes is shown to be dependent on the activation state of the cells, with stimulation by the lectin, concanavalin A, producing a marked decrease in Thy-1-associated kinase activity. In such activated cells, there is an increased association of kinase activity with CD48, but this may be explained in terms of increased surface expression of CD48 and of increased total kinase activity. Additional phosphoproteins of 85, 36 and 32 kDa were consistently seen as components of the complexes.


Assuntos
Antígenos CD/metabolismo , Antígenos de Superfície/metabolismo , Glicoproteínas de Membrana/metabolismo , Proteínas Tirosina Quinases/metabolismo , Proteínas Proto-Oncogênicas/metabolismo , Animais , Antígeno CD48 , Membrana Celular/metabolismo , Concanavalina A/farmacologia , Glicosilfosfatidilinositóis/metabolismo , Ativação Linfocitária , Proteína Tirosina Quinase p56(lck) Linfócito-Específica , Camundongos , Camundongos Endogâmicos BALB C , Proteínas Proto-Oncogênicas c-fyn , Ratos , Transdução de Sinais/imunologia , Transdução de Sinais/fisiologia , Linfócitos T/imunologia , Linfócitos T/metabolismo , Antígenos Thy-1
17.
Cell Biol Int ; 25(1): 33-42, 2001.
Artigo em Inglês | MEDLINE | ID: mdl-11237406

RESUMO

Thy-1, a glycosylphosphatidylinositol (GPI)-anchored glycoprotein expressed at high levels on thymocytes, has been implicated in positive and negative signal transduction. We show that Thy-1 associates with a protein of 85--90 kDa, which is prominently phosphorylated in vitro as well as in vivo following the stimulation of thymocytes with pervanadate. pp85--90 is not identical to known proteins that are phosphorylated following T cell activation. The SH2 domains of fyn, csk, phosphatidylinositol 3'-kinase, rasGAP, vav and lck bind to pp85--90 with varying affinities. The SH2 domains of ZAP70, SHP-1 and PLC gamma 1 and the SH3 domains of lck, vav and HS1 did not bind to pp85--90. The molecular weight, iso-electric point, efficient phosphorylation by fyn and lck and preferential binding to the SH2 domain of fyn compared to that of lck indicate that Thy-1-associated pp85-90 may be identical to a recently cloned, fyn-associated transmembrane adaptor protein, PAG-85.


Assuntos
Transdução de Sinais , Antígenos Thy-1/química , Antígenos Thy-1/metabolismo , Animais , Sítios de Ligação , Eletroforese em Gel Bidimensional , Eletroforese em Gel de Poliacrilamida , Glutationa Transferase/metabolismo , Concentração de Íons de Hidrogênio , Ativação Linfocitária , Fosforilação , Ligação Proteica , Estrutura Terciária de Proteína , Proteínas Proto-Oncogênicas/química , Proteínas Proto-Oncogênicas c-fyn , Ratos , Ratos Endogâmicos Lew , Proteínas Recombinantes de Fusão/metabolismo , Linfócitos T/metabolismo , Domínios de Homologia de src
18.
Am J Drug Alcohol Abuse ; 19(3): 359-68, 1993.
Artigo em Inglês | MEDLINE | ID: mdl-8213699

RESUMO

Three hundred and eight subjects were screened over the phone for admission to an inpatient alcohol treatment research unit. Using a structured interview, the prospective patients were asked questions regarding demographics, drinking history, previous treatments, physical health, family history, and a detailed history of past and present substance use. Drug use was studied as regular use versus no use or brief experimental use of five drug categories: cannabinoids, stimulants, sedatives, opiates, and hallucinogens. Fifty-one percent of the men and 48% of the women reported regular use of one or more of the drugs in addition to alcohol. For women, the amount of alcohol intake was positively correlated with use of stimulants (r = .32, p = .001), cannabinoids (r = .24, p = .019), sedatives (r = .30, p = .003), and hallucinogens (r = .30, p = .003). For men, correlations between the amount of alcohol intake and drug use were weaker but significant for stimulants (r = .21, p = .002), opiates (r = .15, p = .028), and hallucinogens (r = .15, p = .029). Women with alcoholic mothers displayed higher alcohol intake than women with nonalcoholic mothers (p = .02) and also showed more frequent use of most drugs. Although men with alcoholic fathers also showed greater alcohol intake compared to men with nonalcoholic fathers, the two groups did not differ in drug use. Younger subjects of both sexes were more likely to use cannabinoids, stimulants, opiates, and hallucinogens. Alcohol and sedative use was relatively constant across all age groups.


Assuntos
Alcoolismo/epidemiologia , Programas de Rastreamento , Transtornos Relacionados ao Uso de Substâncias/epidemiologia , Adulto , Alcoolismo/psicologia , Alcoolismo/reabilitação , Comorbidade , Estudos Transversais , Feminino , Humanos , Drogas Ilícitas , Incidência , Masculino , Maryland , Pessoa de Meia-Idade , Admissão do Paciente , Determinação da Personalidade , Psicotrópicos , Transtornos Relacionados ao Uso de Substâncias/psicologia , Transtornos Relacionados ao Uso de Substâncias/reabilitação
19.
J Cell Sci ; 107 ( Pt 7): 1783-96, 1994 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-7983148

RESUMO

The surface glycoprotein, Thy-1, when expressed by transfection in NG115/401L neural cells, inhibits their neurite outgrowth over astrocytes. We have investigated the role of the glycosylphosphatidylinositol anchor of Thy-1 in this inhibition. Hybrid molecules, in which the lipid anchor was replaced by polypeptide transmembrane domains, were expressed by transfection. Lines expressing Thy-1 with the transmembrane and full cytoplasmic domains of NCAM-140, or with the transmembrane and truncated cytoplasmic domain of CD8, were not inhibited in their ability to extend neurites over astrocytes. Truncation of the cytoplasmic domain of NCAM-140 to just two amino acids, however, produced a transmembrane form of Thy-1 that, when expressed at high levels, inhibited neurite outgrowth. All forms of Thy-1 were concentrated in clusters that occurred primarily on fine filopodia. In double transfectants expressing normal Thy-1 and Thy-1 with the full NCAM cytoplasmic tail, the clusters of each form were separate, with no instances of the transmembrane form being found within the clusters of lipid-anchored Thy-1. Thy-1 with the two-amino-acid cytoplasmic domain of NCAM also occurred in clusters separate from those occupied by lipid-anchored Thy-1, but substantial 'invasion' of the clusters of normal Thy-1 by this transmembrane construct occurred. We suggest that the ability of this hybrid protein to enter the lipid-anchored clusters enables it to activate the signalling pathways that normal Thy-1 uses. Thus the membrane anchor, in targetting Thy-1 to different microdomains on the cell surface, determines its ability to inhibit neurite outgrowth on astrocytes.


Assuntos
Astrócitos/fisiologia , Moléculas de Adesão Celular Neuronais/metabolismo , Adesão Celular , Membrana Celular/fisiologia , Glicosilfosfatidilinositóis/metabolismo , Neuritos/fisiologia , Antígenos Thy-1/metabolismo , Sequência de Aminoácidos , Animais , Sequência de Bases , Moléculas de Adesão Celular Neuronais/análise , Moléculas de Adesão Celular Neuronais/biossíntese , Membrana Celular/ultraestrutura , Glioma , Células Híbridas , Camundongos , Microscopia Imunoeletrônica , Dados de Sequência Molecular , Mutagênese Sítio-Dirigida , Neuroblastoma , Oligodesoxirribonucleotídeos , Mutação Puntual , Reação em Cadeia da Polimerase , Ratos , Mapeamento por Restrição , Antígenos Thy-1/análise , Antígenos Thy-1/biossíntese , Transfecção
20.
Eur J Immunol ; 27(3): 679-86, 1997 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-9079809

RESUMO

CD5 is a glycoprotein expressed on thymocytes, T cells, and a subset of B cells. Antibody-mediated cross-linking studies or studies on CD5 knockout mice implicate CD5 as a co-stimulatory or negative regulatory molecule. CD5 is rapidly phosphorylated on tyrosine (Y) residues following Tcell activation. Y429 and Y441 occur in an imperfect immunoreceptor tyrosine-based activation motif (ITAM)-like sequence. We investigated whether phosphatidylinositol (PI) 3-kinase, which binds to tyrosine-phosphorylated ITAM, interacts with CD5 following T cell activation. PI 3-kinase activity and the regulatory p85 subunit of PI 3-kinase associated with CD5 in pervanadate-stimulated, but not in unstimulated thymocytes. Cellular p85 as well as the recombinant Src homology 2 (SH2) domains of p85 bound a tyrosine-phosphorylated peptide encompassing Y463 with approximately threefold greater affinity than a doubly tyrosine-phosphorylated Y429-Y441 peptide. Binding of the C-SH2 domain to the Y463 phosphopeptide, together with preferential binding of the N-SH2 domain to the Y429-Y441 phosphopeptide, suggests a bivalent interaction. A 120-kDa phosphoprotein (pp120) associated with CD5 and specifically with the Y429-Y441 phosphopeptide in stimulated thymocytes. We conclude that stimulation of thymocytes with pervanadate induces the recruitment of PI 3-kinase and pp120 to CD5.


Assuntos
Antígenos CD5/metabolismo , Moléculas de Adesão Celular/metabolismo , Ativação Linfocitária , Fosfotransferases (Aceptor do Grupo Álcool)/metabolismo , Proteínas Tirosina Quinases/metabolismo , Timo/fisiologia , Sequência de Aminoácidos , Animais , Sequência Consenso , Citoplasma/metabolismo , Quinase 1 de Adesão Focal , Proteína-Tirosina Quinases de Adesão Focal , Humanos , Substâncias Macromoleculares , Dados de Sequência Molecular , Fosfatidilinositol 3-Quinases , Fosfopeptídeos/metabolismo , Ligação Proteica , Ratos , Transdução de Sinais , Timo/citologia , Domínios de Homologia de src
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