RESUMO
Next-generation sequencing has revolutionized family-based association tests for rare variants. As the lower power of genome wide association study for detecting casual rare variants, methods aggregating effects of multiple variants have been proposed, such as burden tests and variance component tests. This paper summarizes the methods of rare variants association test that can be applied for family data, introduces their principles, characteristics and applicable conditions and discusses the shortcomings and the improvement of the present methods.
Assuntos
Variação Genética , Estudo de Associação Genômica Ampla , Simulação por Computador , Relações Familiares , Estudos de Associação Genética , Estudo de Associação Genômica Ampla/métodos , HumanosRESUMO
Invasive pulmonary aspergillosis (IPA) has been increasingly frequent in severe liver disease. We aim to investigate the clinical presentation, predisposing factors, and treatment of IPA in patients with liver failure caused by hepatitis B virus (HBV) infection. Medical records from 798 patients with HBV-related liver failure were reviewed. A total of 43 patients with probable IPA were selected as the case group, another 43 patients with bacterial infection and 43 patients without any infections were selected, for whose age, sex, date of admission, and the disease onset were matched with the case group. We evaluated the risk factors, clinical manifestations, treatment, and subsequent outcome of IPA in patients with HBV-related liver failure. Multivariate logistic regression models were used to demonstrate risk factors associated with IPA. Compared with patients with bacterial infection and those without any infection, patients with probable IPA used more antibiotics and steroids, and had poorer conditions and the highest mortality (P < 0.0001). Multiple antibiotics use and frequent invasive procedures were independent factors associated with the occurrence of IPA in patients with HBV-related liver failure. Patients with HBV-related liver failure are predisposed to IPA and may have a more severe condition and poorer prognosis.
Assuntos
Hepatite B Crônica/complicações , Aspergilose Pulmonar Invasiva/epidemiologia , Aspergilose Pulmonar Invasiva/patologia , Falência Hepática/complicações , Adulto , Estudos de Casos e Controles , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Fatores de Risco , Resultado do TratamentoRESUMO
Objective: To explore the blood pressure levels and the influencing factors of hypertension among Hainan centenarians, and provide basic data for the further blood pressure related studies of the centenarian population. Methods: The baseline data were from China Hainan Centenarian Cohort Study (CHCCS). This cross-sectional data, based on the community population, was a complete sample study of centenarians, including questionnaire survey, physical examination and physiological index detection. A total of 1 002 centenarians were recruited to describe the blood pressure level. According to the guidelines for the prevention and treatment of hypertension in Chinese adults in 2018, the prevalence of hypertension was analyzed. Results: The median levels of systolic blood pressure, diastolic pressure and pulse pressure were 152.0, 76.0 and 76.5 mmHg, respectively. Blood pressure level was higher in females than in males. The prevalence of hypertension was 71.9%, mainly in isolated systolic hypertension with the prevalence of 60.1%. The results of multivariate analysis showed that the risk of hypertension in women was higher than that in men (OR=1.624, 95%CI: 1.155-2.283), and the risk of hypertension in the northern (OR=0.625, 95%CI: 0.434-0.901) and central areas (OR=0.586, 95%CI: 0.346-0.993) was lower than that of the Eastern. Conclusion: The prevalence of hypertension, mainly in isolated systolic hypertension, showing gender and regional distribution differences.
Assuntos
Hipertensão , Idoso de 80 Anos ou mais , Pressão Sanguínea , China/epidemiologia , Estudos de Coortes , Estudos Transversais , Feminino , Humanos , Hipertensão/epidemiologia , Masculino , Prevalência , Fatores de RiscoRESUMO
As part of a study of the effects of lithium carbonate on neurochemical function in man, platelet and lymphocyte adenylate cyclase activity and lymphocyte beta-adrenergic receptor binding characteristics were determined before and after 2 weeks of lithium treatment in 10 normal volunteers. Lithium had differential effects on platelet and lymphocyte adenylate cyclase activity. In platelets, basal and stimulated (guanyl imidodiphosphate [Gpp[NH]p] or cesium fluoride) adenylate cyclase activity was significantly augmented by lithium treatment. By contrast, in lymphocytes, Gpp(NH)p- and cesium fluoride-stimulated adenylate cyclase activity was unaffected, while basal activity was decreased modestly after lithium. These results are consistent with preclinical studies that suggest that lithium's effects on adenylate cyclase activity are specific with respect to tissue and brain region and that lithium may interfere with guanine nucleotide binding (G) protein function. Lithium treatment significantly increased the ratio of low- to high-affinity dissociation constants for agonist displacement of antagonist binding to lymphocyte beta-adrenergic receptors (thought to reflect coupling between the beta-adrenergic receptor and stimulatory G protein). Lithium had significant effects on measures associated with signal transduction that might be contrasted to its more subtle effects on neuronal function (norepinephrine release) and neuroendocrine systems (responses to serotoninergic challenge) in these same subjects (reported in a companion article). Lithium's primary site of action may be on signal transduction mechanisms. These effects subsequently may be manifested in changes in neurotransmitter function that may be important to lithium's mood-stabilizing actions.
Assuntos
Adenilil Ciclases/metabolismo , Fluoretos , Lítio/farmacologia , Receptores Adrenérgicos beta/metabolismo , Adulto , Afeto/efeitos dos fármacos , Plaquetas/efeitos dos fármacos , Plaquetas/enzimologia , Césio/metabolismo , Feminino , Guanosina Trifosfato/metabolismo , Guanosina Trifosfato/farmacologia , Guanilil Imidodifosfato/metabolismo , Humanos , Lítio/sangue , Lítio/metabolismo , Carbonato de Lítio , Linfócitos/efeitos dos fármacos , Linfócitos/enzimologia , Masculino , Proteínas do Tecido Nervoso/metabolismo , Norepinefrina/metabolismo , Estudos Prospectivos , Receptores Adrenérgicos beta/efeitos dos fármacos , Sistemas do Segundo Mensageiro/efeitos dos fármacos , Serotonina/farmacologia , Serotonina/fisiologia , Transdução de Sinais/efeitos dos fármacosRESUMO
We have analyzed the expression of immunoglobulin lambda chains in the rat by hybridizing RNA from various sources with C lambda 1-like and C lambda 2-like sequences recovered from a rat genomic library. A 1.0 kb lambda 2-like sequence is readily detected in lambda-producing hybridomas and in normal rat spleen RNAs; a 1.0 kb lambda 1-like message is also present, although at much lower levels. An additional 700 b.p. C lambda 2-like fragment is found in all normal rat spleens, and presumably represents a defective message. The nucleotide sequence of one cDNA clone isolated from the lambda-producing hybridoma G36/1 shows a lambda 2-like sequence, and six lambda-secreting hybridomas produced from the spleen of a kappa-suppressed rat all express a C lambda 2-like message. The great majority of rat lambda chains therefore appear to be lambda 2-like. Northern blot analysis of RNA from the spleen of this kappa-suppressed rat shows a considerable increase in the expression of both lambda 2-like and (at lower levels) lambda 1-like message. The coordinate rise of lambda 1 and lambda 2 RNA in this rat suggests that there may be at least two functional lambda chain genes in the rat, although there is as yet no evidence for the existence of rat lambda 1-like proteins.
Assuntos
Cadeias lambda de Imunoglobulina/genética , RNA Mensageiro/análise , Animais , Sequência de Bases , Linhagem Celular , Eletroforese em Gel de Ágar , Hibridomas/imunologia , Cadeias lambda de Imunoglobulina/biossíntese , Dados de Sequência Molecular , RNA/análise , Ratos , Ratos Endogâmicos , Baço/análiseRESUMO
We present a multiple time windows beamformer (MTWB) method of solving the inverse problem of magnetic field and non-invasively imaging the cardiac electrical excitation conduction using the magnetocardiac signals acquired by a 61-channel superconducting quantum interference device (SQUID). The MTWB constructs spatial filters for each location in source space, one for each component of the source moment based on the distributed source model, and estimates the cardiac equivalent current sources. The output of spatial filters is the source strength estimated in three-dimensional space and the weight matrix calculated with magnetocardiac signals in multiple time windows. A signal subspace projection technique is used to suppress noise. Then, the characteristics of cardiac electrical excitation conduction among two healthy subjects and two coronary vessel stenosis (CVS) patients are extracted from reconstructed current sources with maximum strength at each instant during QRS complex and ST-T segment, and a series of two-dimensional cardiac electrical excitation conduction maps (EECM) are obtained. It is demonstrated that two healthy subjects are of similar and the stronger electrical activities than those of two CVS patients. This technique can be used as an effective tool for the diagnosis of heart diseases.
Assuntos
Coração , Frequência Cardíaca , HumanosRESUMO
The Dexamethasone Suppression Test (DST) was performed in 64 depressed inpatients, in 48 schizophrenics, and in 20 normal controls. Thirty-four percent of depressive inpatients were found to escape from dexamethasone suppression significantly higher than either schizophrenics (13%) or normal subjects (5%). Among subgroups, bipolar and unipolar endogenous depression patients had much higher abnormal rates for the DST (59% and 48%, respectively) than nonendogenous cases (8%). DST results were also found to be positively correlated with patients' Hamilton scores. These findings suggested that DST could be helpful in diagnosis, discrimination of subtypes, and in assessment of severity of symptoms. In 32 of the 64 depressed inpatients, urinary MHPG X SO4 excretion was determined and compared with 21 normal controls. Bipolar patients (n = 7) had less MHPG X SO4 excretion than unipolar endogenous patients (n = 16). Excretion was positively correlated with cortisol level at 17 hr after dexamethasone administration in 32 depressive inpatients, especially in the unipolar subgroup. A trend toward negative correlation, though not statistically significant, was found in bipolar depression between cortisol levels at 17 hr after dexamethasone administration and urinary MHPG X SO4 excretion. This may indicate that some differences in norepinephrine (NE) metabolism may exist between unipolar and bipolar depression, leading to differing correlations between deviation of central NE function and hypothalamus-pituitary-adrenal (HPA) axis in different subgroups of depression.
Assuntos
Transtorno Bipolar/diagnóstico , Transtorno Depressivo/diagnóstico , Dexametasona , Glicóis/urina , Hidrocortisona/sangue , Metoxi-Hidroxifenilglicol/urina , Esquizofrenia/diagnóstico , Adulto , Transtorno Bipolar/metabolismo , Transtorno Depressivo/metabolismo , Feminino , Humanos , Masculino , Metoxi-Hidroxifenilglicol/análogos & derivados , Esquizofrenia/metabolismoRESUMO
A dosage regimen of lysergic acid diethylamide (LSD) that reliably produces behavioral tolerance in rats was evaluated for effects on neurotransmitter receptor binding in rat brain using a variety of radioligands selective for amine receptor subtypes. Daily administration of LSD [130 micrograms/kg (0.27 mumol/kg) intraperitoneally (IP)] for 5 days produced a decrease in serotonin2 (5-hydroxytryptamine2, 5-HT2) binding in cortex (measured 24 hours after the last drug administration) but did not affect binding to other receptor systems (5-HT1A, 5-HT1B, beta-adrenergic, alpha 1- or alpha 2-adrenergic, D2-dopaminergic) or to a recognition site for 5-HT uptake. The decrease was evident within 3 days of LSD administration but was not demonstrable after the first LSD dose. Following 5 days of LSD administration the decrease was still present 48 hours, but not 96 hours, after the last administration. The indole hallucinogen psilocybin [1.0 mg/kg (3.5 mumol/kg) for 8 days] also produced a significant decrease in 5HT2 binding, but neither the nonhallucinogenic analog bromo-LSD [1.3 mg/kg (2.4 mumol/kg) for 5 days] nor mescaline [10 mg/kg (40.3 mumol/kg) for 5 or 10 days] affected 5-HT2 binding. These observations suggest that LSD and other indole hallucinogens may act as 5-HT2 agonists at postsynaptic 5-HT2 receptors. Decreased 5-HT2 binding strikingly parallels the development and loss of behavioral tolerance seen with repeated LSD administration, but the decreased binding per se cannot explain the gamut of behavioral tolerance and cross-tolerance phenomena among the indole and phenylethylamine hallucinogens.
Assuntos
Encéfalo/metabolismo , Regulação para Baixo/efeitos dos fármacos , Dietilamida do Ácido Lisérgico/farmacologia , Receptores de Serotonina/metabolismo , Animais , Córtex Cerebral/metabolismo , Ketanserina/metabolismo , Masculino , Mescalina/farmacologia , Especificidade de Órgãos , Psilocibina/farmacologia , Ensaio Radioligante , Ratos , Ratos Endogâmicos , Receptores de Serotonina/efeitos dos fármacos , Valores de ReferênciaRESUMO
BACKGROUND: Many studies have indicated that excess free radical formation may be involved in the pathogenesis of patients with schizophrenia. Some investigators suggested that the use of free radical scavengers might provide improvement in schizophrenia. The aim of this study was to determine the effectiveness and to evaluate the side effects of extract of Ginkgo biloba (EGb) plus haloperidol in chronic, treatment-resistant inpatients with schizophrenia. METHOD: One hundred nine patients meeting DSM-III-R criteria for schizophrenia completed a double-blind, placebo-controlled, parallel-group study of EGb plus haloperidol. Fifty-six of the patients were randomly assigned to receive a fixed dose of 360 mg/day of EGb plus a stable dose of haloperidol, 0.25 mg/kg/day, and 53 were assigned to receive placebo plus the same dose of haloperidol for 12 weeks. Patients were assessed using the Brief Psychiatric Rating Scale (BPRS), the Scale for the Assessment of Negative Symptoms (SANS), and the Scale for the Assessment of Positive Symptoms (SAPS) at baseline, week 6, and week 12 and the Treatment Emergent Symptom Scale (TESS) for side effects at week 12. RESULTS: There was a significant reduction in both groups in BPRS total score after 12 weeks of treatment (p < .05). However, a significant reduction in total SAPS and SANS scores was noted in the EGb group (p < .05), but not in the placebo group. There was a lower SAPS total score in the EGb group than in the placebo group at the end of 12 weeks of treatment (p < .05). Of those treated with EGb plus haloperidol, 57.1% were rated as responders as compared with only 37.7% of those receiving placebo plus haloperidol when assessed by the SAPS (chi2 = 4. 111, p = .043). After 12 weeks of treatment, TESS subscore 1 (behavioral toxicity) and subscore 3 (symptoms of nerve system) were significantly decreased in the EGb group compared with the placebo group (p < .05). CONCLUSION: EGb treatment may enhance the effectiveness of antipsychotic drugs and reduce their extrapyramidal side effects.
Assuntos
Antipsicóticos/uso terapêutico , Sequestradores de Radicais Livres/uso terapêutico , Ginkgo biloba , Haloperidol/uso terapêutico , Fitoterapia , Esquizofrenia/tratamento farmacológico , Antipsicóticos/administração & dosagem , Escalas de Graduação Psiquiátrica Breve , Método Duplo-Cego , Quimioterapia Combinada , Feminino , Seguimentos , Haloperidol/administração & dosagem , Humanos , Masculino , Esquizofrenia/diagnósticoRESUMO
Daily administration of D-lysergic acid diethylamide (LSD) was previously shown to decrease serotonin2 (5-HT2) receptor binding in rat brain. Recently, 4-substituted derivatives of 1-(2,5-dimethoxyphenyl)-2-aminopropane, the substitution being with either iodine (DOI) or bromine (DOB), have been suggested to be relatively selective 5-HT2 agonists. These compounds share common behavioral and neurophysiological effects with LSD, suggested to be 5-HT2 receptor mediated, and the purpose of the present study was to determine whether they also affect 5-HT2 receptor binding after systemic administration in a similar way to LSD. Administration of DOI (1.0 mg/kg) or DOB (0.5 mg/kg) for 7 days resulted in a decrease in 5-HT2 binding, as evaluated with [3H]ketanserin, similar to the decrease after LSD. In a further evaluation of the parallelism of LSD and 5-HT2 agonists, it was found that 24 hr after one administration of a low dose of LSD (130 ug/kg) or DOI (1.0 mg/kg), there was no change in binding, but there was a decrease 24 hr after a high dose (LSD, 650 micrograms/kg; DOI, 7.0 mg/kg). Four hours after the high dose of LSD or DOI there was also a decrease in 5-HT2 binding. Thus, results have shown that 5-HT2 agonists are capable of down-regulating 5-HT2 receptors and that LSD acts in a parallel fashion. This study has also demonstrated that 5-HT2 receptors can be modified within hours after drug administration.
Assuntos
Anfetaminas/farmacologia , Encéfalo/metabolismo , 2,5-Dimetoxi-4-Metilanfetamina/farmacologia , Receptores de Serotonina/metabolismo , 2,5-Dimetoxi-4-Metilanfetamina/análogos & derivados , Animais , Encéfalo/efeitos dos fármacos , Alucinógenos , Ketanserina/metabolismo , Dietilamida do Ácido Lisérgico/farmacologia , Masculino , Ratos , Ratos Endogâmicos , Receptores de Serotonina/efeitos dos fármacos , Serotonina/metabolismoRESUMO
The purpose of this study was to compare the efficacy and safety of risperidone and haloperidol in treatment-resistant chronic schizophrenic patients. Subjects (n = 78) who met DSM-III criteria for schizophrenia were randomly assigned to receive 6 mg/day of risperidone or 20 mg/day of haloperidol for 12 weeks. Clinical efficacy was determined using the Positive and Negative Syndrome Scale (PANSS), and side-effects with the Treatment Emergent Symptom Scale (TESS). Risperidone produced a mean 39.8 +/- 24.1% reduction in total PANSS score compared to a mean 28.3 + 19.4% reduction in the haloperidol group (P < 0.05). Analysis of changes for the three subscores of the PANSS revealed that the general psychopathology and negative subscores were significantly improved in the risperidone group compared to the haloperidol group. As for the side-effects, the risperidone group showed a significantly lower TESS total score, as well as nervous system symptoms subscore and cardiovascular symptoms subscore, compared to the haloperidol group. Risperidone appears to be a more effective and better tolerated antipsychotic drug in treatment-refractory Chinese schizophrenia than haloperidol.
Assuntos
Antipsicóticos/efeitos adversos , Antipsicóticos/uso terapêutico , Haloperidol/efeitos adversos , Haloperidol/uso terapêutico , Risperidona/efeitos adversos , Risperidona/uso terapêutico , Esquizofrenia/tratamento farmacológico , Adulto , Povo Asiático , Doença Crônica , Método Duplo-Cego , Feminino , Humanos , Pacientes Internados , Masculino , Pessoa de Meia-Idade , Escalas de Graduação Psiquiátrica , Psicologia do EsquizofrênicoRESUMO
The effects of ethanol on serotonin (5-hydroxytryptamine, 5-HT) receptor binding in rat and mouse brain were determined under in vitro conditions and in mouse brain following seven days of ethanol ingestion. 5-HT1A receptor characteristics were measured utilizing the agonist [3H]8-hydroxy-2-(di-n-propylamino)tetralin ([ 3H]DPAT), and 5HT2 receptor-binding studies utilized the antagonist [3H]ketanserin. At the highest concentration of ethanol tested in vitro (680 mM), there was only 25% inhibition of [3H]DPAT binding in rat and mouse brain and 14% inhibition of [3H]ketanserin binding in rat brain. Effects of an anesthetic concentration of ethanol (100 mM) on agonist binding in the presence and absence of the guanine nucleotide GTP were also evaluated in vitro in mouse brain. In no case did ethanol (100 mM) significantly affect 5-HT1A or 5-HT2 receptor-binding characteristics. When 5-HT receptor characteristics were measured after mice consumed ethanol for seven days, there was no change in either 5-HT1A or 5-HT2 receptor-binding properties in any of the brain areas examined.
Assuntos
Encéfalo/ultraestrutura , Etanol/farmacologia , Receptores de Serotonina/metabolismo , 8-Hidroxi-2-(di-n-propilamino)tetralina , Animais , Ketanserina/antagonistas & inibidores , Masculino , Camundongos , Camundongos Endogâmicos , Ligação Proteica/efeitos dos fármacos , Tetra-Hidronaftalenos/antagonistas & inibidores , TrítioAssuntos
Transplante de Córnea , Rejeição de Enxerto , Adolescente , Adulto , Idoso , Criança , Feminino , Humanos , Imunossupressores/uso terapêutico , Masculino , Pessoa de Meia-Idade , Fatores de TempoRESUMO
OBJECTIVE: To determine the prevalence of dementia and Alzheimer's disease (AD) in rural China. METHODS: A cross-sectional study was conducted within a cohort of adults older than 50 years of age in Linxian County, China. A Chinese version of the Mini-Mental State Examination (CMMSE) was used to screen cases of possible dementia. Three different cutoff points on CMMSE were applied depending on the participant's level of education. The participants then were given psychiatric interviews, medical and neurological examinations, and psychometric tests to ascertain the clinical diagnoses of dementia and AD. RESULTS: Among the 16,095 participants, 5.26% were screened positive with 374 diagnosed as having dementia. Among them, AD accounted for 80.5%. The adjusted prevalence rates were 0.33%, 0.89%, 3.43%, and 8.19% in people in age groups 50-54, 55-64, 65-74, and 75 and above, respectively. The prevalence of AD correlated with the participant's level of education, and was 2.61%, 0.94%, and 0.56% in the illiterate group, in the primary school group, and in the middle school or higher group, respectively. Adjusted by education levels a higher prevalence in women was observed in the illiterate group. CONCLUSIONS: The prevalence of dementia in this population is similar to that reported from other areas in mainland China and Taiwan with aging being a significant risk factor. After controlling for age, being a female and having received less number of years of education were associated with an higher prevalence of AD.
Assuntos
Doença de Alzheimer/epidemiologia , Demência/epidemiologia , Transtornos da Memória/epidemiologia , População Rural/estatística & dados numéricos , Distribuição por Idade , Idoso , Idoso de 80 Anos ou mais , Envelhecimento/fisiologia , Doença de Alzheimer/diagnóstico , Doença de Alzheimer/fisiopatologia , Causalidade , China/epidemiologia , Estudos de Coortes , Estudos Transversais , Demência/diagnóstico , Demência/psicologia , Escolaridade , Feminino , Humanos , Masculino , Programas de Rastreamento/métodos , Transtornos da Memória/diagnóstico , Transtornos da Memória/fisiopatologia , Pessoa de Meia-Idade , Testes Neuropsicológicos , Prevalência , População Rural/tendências , Distribuição por SexoRESUMO
The purpose of the study was to evaluate the effect of the classic antipsychotic haloperidol plus extract of ginkgo biloba (EGb) on treatment-resistant chronic schizophrenia and on blood superoxide dismutase (SOD) levels. Eighty-two patients with chronic refractory schizophrenia were studied. Forty-three patients were treated with haloperidol plus extract of ginkgo biloba (group 1), and 39 received haloperidol plus placebo (group 2). SOD levels of these patients were measured before and after treatment and were compared with SOD levels of 30 healthy volunteers. Therapeutic efficiency was equated with a change in clinical rating scores assessed by standardized measurement tools that included the Scale for the Assessment of Positive Symptoms and the Scale for the Assessment of Negative Symptoms (SANS) over this period. Patients in group 1 improved significantly as demonstrated by scores from these two assessment instruments; those in group 2 improved significantly only as shown by scores on SANS. SOD levels before treatment in all patients were significantly higher than those in healthy controls; after treatment, the SOD level decreased significantly in group 1 but not in group 2. These results suggest that EGb may enhance the efficiency of the classic antipsychotic haloperidol in patients with schizophrenia, especially on their positive symptoms, and that EGb may work through an antioxidant effect that is involved in the therapeutic mechanism in patients with chronic refractory schizophrenia.
Assuntos
Antipsicóticos/farmacologia , Ginkgo biloba/uso terapêutico , Haloperidol/farmacologia , Fitoterapia , Plantas Medicinais , Esquizofrenia/enzimologia , Superóxido Dismutase/metabolismo , Adulto , Antipsicóticos/uso terapêutico , Doença Crônica , Interações Medicamentosas , Quimioterapia Combinada , Feminino , Ginkgo biloba/química , Haloperidol/uso terapêutico , Humanos , Masculino , Pessoa de Meia-Idade , Extratos Vegetais/uso terapêutico , Esquizofrenia/tratamento farmacológico , Superóxido Dismutase/efeitos dos fármacos , Resultado do TratamentoRESUMO
Mouse phagocytic glycoprotein-1 (Pgp-1; Ly-24) is a 95-kDa glycoprotein of unknown function that has served as an important T cell/leukocyte differentiation marker. Recent work has suggested that it may be related to a human 85- to 95-kDa glycoprotein (termed variously the Hermes Ag/lymphocyte homing receptor, ECMRIII, P80, and CD44) that is involved in lymphocyte binding to high endothelial venules in the process of lymphocyte homing, and has been implicated in other cell adhesion events. The widespread expression of this molecular class in diverse organ systems suggests a broad role in cellular adhesion, and has led to the unifying designation homing-cellular adhesion molecule (H-CAM). By using human H-CAM cDNA probes, we have isolated a full-length cDNA for the mouse homolog. Comparison of the human and mouse sequences reveals that an N-terminal domain homologous to cartilage proteoglycan core and link proteins, as well as the C-terminal transmembrane and cytoplasmic sequences, are highly conserved (89% and 86% identity, respectively). In contrast, a proximal extracellular domain thought to serve as a target for O-glycosylation and chondroitin sulfate attachment has undergone substantial divergence (only 42% identity). Transient expression of the cDNA in CHO cells followed by immunologic staining confirms that this mouse H-CAM cDNA encodes Pgp-1.1, one of two known Pgp-1 alloantigens.
Assuntos
Sequência de Bases , Moléculas de Adesão Celular/genética , Receptores Imunológicos/genética , Homologia de Sequência do Ácido Nucleico , Sequência de Aminoácidos , Animais , Antígenos Ly/genética , Antígenos Ly/isolamento & purificação , Western Blotting , Moléculas de Adesão Celular/isolamento & purificação , Linhagem Celular , Clonagem Molecular , Cricetinae , Cricetulus , DNA/isolamento & purificação , Feminino , Humanos , Glicoproteínas de Membrana/genética , Glicoproteínas de Membrana/isolamento & purificação , Camundongos , Dados de Sequência Molecular , Ovário , Receptores de Retorno de LinfócitosRESUMO
BACKGROUND: Eosinophils selectively accumulate at sites of allergic inflammation. Their recruitment is dependent on both the expression and functional activity of cell adhesion molecules. How the functional activity of cell adhesion molecules on eosinophils is regulated is poorly understood. OBJECTIVE: Our objective was to examine the functional activity of alpha 4 integrins on human eosinophils and its regulation by various agents. METHODS: Function of alpha 4 integrins on human eosinophils was examined by testing adhesion to immobilized fibronection and vascular cell adhesion molecule-1 (VCAM-1) in the presence or absence of a monoclonal antibody (mAb) (8A2) that activates beta 1 integrin function. RESULTS: Spontaneous eosinophil adhesion to VCAM-1 was enhanced by 8A2, but adhesion to fibronectin could only be detected in the presence of 8A2. Concentrations of 8A2 that were approximately 100-fold less than saturating induced maximal eosinophil adhesion. Adhesion to VCAM-1 in the presence of 8A2 was effectively inhibited by alpha 4 and beta 1 integrin mAbs: beta 7 mAb had partial inhibitory activity. Connecting segment-1 peptide and alpha 4 mAb blocked 8A2-dependent fibronectin binding: beta 1, beta 2, and beta 7 integrin mAbs had partial inhibitory activity. Eosinophils obtained from bronchoalveolar lavage fluids and blood eosinophils stimulated with IL-5, platelet-activating factor, or RANTES displayed increased beta 2 integrin-dependent, not alpha 4 integrin-dependent, attachment. Spontaneous adhesion of eosinophils to VCAM-1 was significantly reduced by the tyrosine kinase inhibitor tyrphostin B46 (inhibitory concentration of 50% approximately equal to 20 mumol/L); this effect was reversed by 8A2. CONCLUSIONS: The functional activity of integrins on eosinophils can be positively and negatively regulated. Altered integrin avidity may influence eosinophil recruitment in vivo.
Assuntos
Antígenos CD/metabolismo , Eosinófilos/fisiologia , Fibronectinas/metabolismo , Integrinas/metabolismo , Tirfostinas , Molécula 1 de Adesão de Célula Vascular/metabolismo , Anticorpos Monoclonais , Antígenos CD/imunologia , Compostos de Benzilideno/farmacologia , Adesão Celular , Inibidores Enzimáticos/farmacologia , Humanos , Integrina alfa4 , Integrina beta1/imunologia , Integrina beta1/metabolismo , Integrinas/imunologia , Células Jurkat/fisiologia , Cinética , Nitrilas/farmacologia , Fragmentos de Peptídeos/metabolismo , Proteínas Tirosina Quinases/antagonistas & inibidores , Transdução de SinaisRESUMO
Germinal centers (GC) constitute a specialized microenvironment essential for the formation of memory B cells, B cell affinity maturation and isotype switching. Within the GC, the B cells closely interact with follicular dendritic cells (FDC) and T cells, which both provide stimuli to the B cells that prevent their entry into apoptosis and promote their differentiation into memory cells or plasma cells. Cross-linking of B cell immunoglobulin (Ig) receptors by antigen, stimulation of the integrin adhesion molecules LFA-1 and VLA-4 on the B cell through interaction with their counter receptors ICAM-1 and VCAM-1 on the FDC and cross-linking of CD40 on the B cells through interaction with the CD40 ligand (CD40L) on T cells have been shown to prevent entry into apoptosis of GC B cells. Triggering of CD95, on the other hand, has been shown to induce apoptosis. We therefore investigated the interaction between adhesion-mediated signals, Ig, CD40, and CD95. The spontaneous apoptosis of GC B cells was not further increased by adding anti-CD95. However, CD95 stimulation did result in apoptosis of GC B cells in the presence of anti-Ig or adhesion-mediated rescue signals, which indicates that CD95 expressed on GC B cells is functionally active. In contrast, anti-CD95 was unable to induce apoptosis in cells rescued via CD40 stimulation, suggesting an important role for CD40L expressed on GC T cells in apoptosis regulation. We also studied apoptosis of B cells adhering to FDC, and found that B cells that interact with FDC were also rescued from CD95-induced apoptosis. A human CD40.Fc mu fusion protein that blocks CD40 ligation failed to inhibit this effect. Our studies therefore indicate that neither CD40, Ig receptors, nor adhesion receptors mediate rescue from apoptosis by FDC.