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1.
Med Teach ; 41(5): 584-590, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-30394166

RESUMO

Purpose: To examine the associations between residents' personality traits, type of specialty, and symptoms of burnout. Method: A cross-sectional online survey among Dutch residents was conducted (see Supplementary Material ). The 20-item Dutch translation of the Maslach Burnout Inventory was used to ascertain burnout. Personality traits were assessed with the 44-item Dutch Big Five Inventory. Logistic regression analyses, including all five personality traits, were used to assess associations with burnout. Analyses were stratified by specialties. Results: One thousand two hundred thirty one residents participated, 185 (15.0%) of whom met the criteria for burnout. Neuroticism was significantly associated with resident burnout in all specialties, more strongly in supportive (odds ratio (OR) 6.19, 95% CI 2.12-18.12) and surgical (OR 4.37, 95% CI 1.76-10.86) than in medical residents (OR 1.99, 95% CI 1.22-3.24). Extraversion was significantly associated with less burnout in surgical residents (OR 0.26, 95% CI 0.13-0.58). These findings remained highly significant after controlling for gender, overtime, autonomy at work, satisfaction between work and private life, and the perceived quality of the learning environment. Conclusions: Burnout risk was associated with personality traits in residents. Consistently, residents scoring high on neuroticism reported more burnout. Extraverted surgical residents were less susceptible to burnout. Residents scoring high on neuroticism may require more intense monitoring during their training years.


Assuntos
Esgotamento Profissional/psicologia , Medicina/estatística & dados numéricos , Personalidade , Médicos/psicologia , Adulto , Esgotamento Profissional/epidemiologia , Estudos Transversais , Extroversão Psicológica , Feminino , Humanos , Internato e Residência , Modelos Logísticos , Masculino , Países Baixos/epidemiologia , Neuroticismo , Desenvolvimento da Personalidade , Inquéritos e Questionários
2.
Adv Health Sci Educ Theory Pract ; 22(4): 803-818, 2017 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-27651045

RESUMO

Burnout is highly prevalent in medical residents. In order to prevent or reduce burnout in medical residents, we should gain a better understanding of contributing and protective factors of burnout. Therefore we examined the associations of job demands and resources, home demands and resources, and work-home interferences with burnout in male and female medical residents. This study was conducted on a nation-wide sample of medical residents. In 2005, all Dutch medical residents (n = 5245) received a self-report questionnaire on burnout, job and home demands and resources and work-home interference. Path analysis was used to examine the associations between job and home characteristics and work-home interference and burnout in both males and females. In total, 2115 (41.1 %) residents completed the questionnaire. In both sexes emotional demands at work and the interference between work and home were important contributors to burnout, especially when work interferes with home life. Opportunities for job development appeared to be an important protective factor. Other contributing and protective factors were different for male and female residents. In females, social support from family or partner seemed protective against burnout. In males, social support from colleagues and participation in decision-making at work seemed important. Effectively handling emotional demands at work, dealing with the interference between work and home, and having opportunities for job development are the most essential factors which should be addressed. However it is important to take gender differences into consideration when implementing preventive or therapeutic interventions for burnout in medical residents.


Assuntos
Esgotamento Profissional/epidemiologia , Esgotamento Profissional/psicologia , Internato e Residência/estatística & dados numéricos , Adulto , Tomada de Decisões , Feminino , Humanos , Satisfação no Emprego , Masculino , Pessoa de Meia-Idade , Países Baixos , Fatores Sexuais , Apoio Social , Equilíbrio Trabalho-Vida , Carga de Trabalho/psicologia
3.
Nephrol Dial Transplant ; 31(6): 914-21, 2016 06.
Artigo em Inglês | MEDLINE | ID: mdl-26681729

RESUMO

BACKGROUND: Antiangiogenic treatment with the multitargeted vascular endothelial growth factor (VEGF) receptor inhibitor sunitinib associates with a blood pressure (BP) rise and glomerular renal injury. Recent evidence indicates that VEGF derived from tubular cells is required for maintenance of the peritubular vasculature. In the present study, we focussed on tubular and glomerular pathology induced by sunitinib and explored whether a high salt (HS) diet augments the BP rise and renal abnormalities. METHODS: Normotensive Wistar Kyoto (WKY) rats were exposed to a normal salt (NS) or HS diet for 2 weeks and subsequently for 8 days to sunitinib or vehicle administration after which the rats were euthanized and kidneys excised. Mean arterial pressure (MAP) was telemetrically measured. Urine was sampled for proteinuria and endothelinuria, and blood for measurement of endothelin-1, creatinine and cystatin C. RESULTS: Compared with the NS diet, MAP rapidly rose by 27 ± 3 mmHg with the HS diet. On sunitinib, MAP rose further by 15 ± 1 with the NS and by 23 ± 4 mmHg with the HS diet (P < 0.05). The HS diet itself had no effect on proteinuria, endothelinuria or the plasma levels of endothelin-1, creatinine and cystatin C. Only with the HS diet, sunitinib administration massively increased proteinuria and endothelinuria and these two parameters were related (r = 0.50, P < 0.01). Likewise, renal glomerular pathology was enhanced during sunitinib with the HS diet, whereas tubulointerstitial injury or reduced peritubular capillary density did not occur. CONCLUSIONS: An HS diet induces a marked BP rise in WKY rats and exacerbates both the magnitude of the BP rise and glomerular injury induced by sunitinib.


Assuntos
Inibidores da Angiogênese/toxicidade , Pressão Sanguínea/efeitos dos fármacos , Indóis/toxicidade , Nefropatias/patologia , Pirróis/toxicidade , Cloreto de Sódio na Dieta/toxicidade , Fator A de Crescimento do Endotélio Vascular/antagonistas & inibidores , Animais , Nefropatias/tratamento farmacológico , Nefropatias/etiologia , Masculino , Ratos , Ratos Endogâmicos WKY , Sunitinibe
4.
Neuropsychobiology ; 71(4): 212-7, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26279280

RESUMO

BACKGROUND: Psychosis spectrum disorders, especially schizophrenia, have been linked to disturbed dopaminergic activity in the brain. Plasma homovanillic acid (pHVA) levels partly represent dopaminergic metabolism in the central nervous system. In the present study associations between (changes in) pHVA levels, symptom severity and symptomatic improvement in patients with psychoses were investigated. METHODS: From a total of 80 patients, 58 fulfilled all inclusion criteria and their symptom profile and severity were assessed by means of the Comprehensive Assessment of Symptoms and History (CASH), the Positive and Negative Syndrome Scale (PANSS) and the Clinical Global Impression Scale for Severity and Improvement (CGI-S/CGI-I) at baseline and after 6 weeks of antipsychotic treatment. After inclusion, all patients were prescribed first- or second-generation antipsychotics by their treating psychiatrist. A total of 12 patients had first-episode psychosis (FEP). At both time points, pHVA levels were measured. Subsequently, pHVA levels were compared with an age-matched control sample and changes in pHVA levels (ΔpHVA) after treatment were associated with clinical parameters. RESULTS: Before analyses, data were scrutinized for possible confounders, particularly gender, smoking, medication status (including antipsychotic class), and recent drug use. The pHVA levels in patients were not different from those in controls. Treatment resulted in a significant decrease of all parameters. Symptomatic improvement as well as ΔpHVA was most pronounced in FEP patients. CONCLUSION: These findings show that patients with FEP have a more favourable outcome than non-FEP patients and that greater ΔpHVA also suggests that FEP patients still have the capacity to adjust dopaminergic neurotransmission.


Assuntos
Antipsicóticos/uso terapêutico , Ácido Homovanílico/sangue , Transtornos Psicóticos/sangue , Transtornos Psicóticos/tratamento farmacológico , Adulto , Feminino , Humanos , Masculino , Escalas de Graduação Psiquiátrica , Resultado do Tratamento
6.
Acta Neuropsychiatr ; 26(4): 223-9, 2014 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-25142290

RESUMO

OBJECTIVE: Brain-derived neurotrophic factor (BDNF) and S100B are involved in brain plasticity processes and their serum levels have been demonstrated to be altered in patients with psychoses. This study aimed to identify subgroups of patients with psychotic disorders across diagnostic boundaries that show a specific symptom profile or response to treatment with antipsychotics, by measuring serum levels of BDNF and S100B. METHODS: The study sample consisted of 58 patients with DSM-IV psychotic disorders. Comprehensive Assessment of Symptoms and History (CASH), Positive and Negative Syndrome Scale (PANSS) and Clinical Global Impression scale for severity and improvement (CGI-S/CGI-I) were applied at baseline and after 6 weeks of antipsychotic treatment. At both time points, serum levels of BDNF and S100B were measured and compared with a matched control sample. RESULTS: Baseline BDNF and S100B levels were significantly lower in patients as compared with controls and did not change significantly during treatment. Dividing the patient sample according to baseline biochemical parameters (low and high 25% and middle 50%), no differences in symptom profiles or outcome were found with respect to BDNF. However, the subgroups with low and high S100B levels had higher PANSS scores than the middle subgroup. In addition, the high subgroup still showed significantly more negative symptoms after treatment, whereas the low subgroup showed more positive symptoms compared with the other subgroups. CONCLUSION: Serum levels of BDNF and S100B are lowered in patients with psychotic disorders across diagnostic boundaries. The differences between high and low S100B subgroups suggest a relationship between S100B, symptom dimensions and treatment response, irrespective of diagnostic categories.


Assuntos
Fator Neurotrófico Derivado do Encéfalo/sangue , Transtornos Psicóticos/sangue , Subunidade beta da Proteína Ligante de Cálcio S100/sangue , Adolescente , Adulto , Idoso , Antipsicóticos/uso terapêutico , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Escalas de Graduação Psiquiátrica , Transtornos Psicóticos/tratamento farmacológico , Resultado do Tratamento , Adulto Jovem
7.
Int J Psychiatry Clin Pract ; 17(2): 125-30, 2013 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-23437800

RESUMO

OBJECTIVE: The aim of the study was to determine the prevalence of cardiometabolic dysregulations and their somatic treatment regimens in a group of psychiatric patients treated with antipsychotics. METHODS: In a naturalistic cohort study, baseline cardiometabolic parameters were measured in 543 outpatients. After one year, a second assessment was performed in 220 patients out of the total sample. In addition, it was investigated whether in patients with somatic comorbidities adequate treatment was prescribed. RESULTS: In this cohort, about half of the patients fulfilled the criteria for metabolic syndrome. Only a limited number of patients, however, received pharmacologic treatment for individual risk factors: About 19% for hypercholesterolemia, 26% for hypertension, and 52% for diabetes. Non-treated patients were significantly younger than treated patients. Follow-up data show that the course of the cardiometabolic parameters can be dynamic. CONCLUSIONS: Cardiometabolic risk factors are highly prevalent in psychiatric patients treated with antipsychotic drugs. Unfortunately, adequate treatment of cardiometabolic comorbidity in these relatively young patients is seriously hampered. Thus, specific guidelines for psychiatric patients have to be developed taking into account the high cardiovascular risk at a relatively young age and potential pharmacokinetic interactions between psychotropics and somatic compounds. Moreover, integration of psychiatric and physical health care systems for patients with mental disorders is urgently needed.


Assuntos
Antipsicóticos/efeitos adversos , Doenças Cardiovasculares/epidemiologia , Transtornos Mentais/epidemiologia , Síndrome Metabólica/epidemiologia , Adolescente , Adulto , Fatores Etários , Doenças Cardiovasculares/induzido quimicamente , Doenças Cardiovasculares/tratamento farmacológico , Estudos de Coortes , Comorbidade , Diabetes Mellitus/tratamento farmacológico , Diabetes Mellitus/epidemiologia , Feminino , Humanos , Hipercolesterolemia/tratamento farmacológico , Hipercolesterolemia/epidemiologia , Hipertensão/tratamento farmacológico , Hipertensão/epidemiologia , Masculino , Transtornos Mentais/tratamento farmacológico , Síndrome Metabólica/induzido quimicamente , Síndrome Metabólica/tratamento farmacológico , Países Baixos/epidemiologia , Prevalência , Psicotrópicos/uso terapêutico , Fatores de Risco
8.
PLoS One ; 18(1): e0280939, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36696439

RESUMO

BACKGROUND: The diagnostic process of patients with suspect pancreatic lesions is often lengthy and prone to repeated diagnostic procedures due to inconclusive results. Targeted Next-Generation Sequencing (NGS) performed on cytological material obtained with fine needle aspiration (FNA) or biliary duct brushing can speed up this process. Here, we study the incremental value of NGS for establishing the correct diagnosis, and subsequent treatment plan in patients with inconclusive diagnosis after regular diagnostic work-up for suspect pancreatic lesions. METHODS: In this prospective cross-sectional cohort study, patients were screened for inclusion in four hospitals. NGS was performed with AmpliSeq Cancer Hotspot Panel v2 and v4b in patients with inconclusive cytology results or with an uncertain diagnosis. Diagnostic results were evaluated by the oncology pancreatic multidisciplinary team. The added value of NGS was determined by comparing diagnosis (malignancy, cystic lesion or benign condition) and proposed treatment plan (exploration/resection, neoadjuvant chemotherapy, follow-up, palliation or repeated FNA) before and after integration of NGS results. Final histopathological analysis or a 6-month follow-up period were used as the reference standard in case of surgical intervention or non-invasive treatment, respectively. RESULTS: In 50 of the 53 included patients, cytology material was sufficient for NGS analysis. Diagnosis before and after integration of NGS results differed in 24% of the patients. The treatment plan was changed in 32% and the diagnosis was substantiated by the NGS data in 44%. Repetition of FNA/brushing was prevented in 14% of patients. All changes in treatment plan were correctly made after integration of NGS. Integration of NGS increased overall diagnostic accuracy from 68% to 94%. INTERPRETATION: This study demonstrates the incremental diagnostic value of NGS in patients with an initial inconclusive diagnosis. Integration of NGS results can prevent repeated EUS/FNA, and can also rigorously change the final diagnosis and treatment plan.


Assuntos
Neoplasias Pancreáticas , Humanos , Estudos Transversais , Neoplasias Pancreáticas/diagnóstico , Neoplasias Pancreáticas/genética , Neoplasias Pancreáticas/patologia , Estudos Prospectivos , Pâncreas/patologia , Sequenciamento de Nucleotídeos em Larga Escala , Aspiração por Agulha Fina Guiada por Ultrassom Endoscópico
9.
Endosc Int Open ; 10(4): E549-E557, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-35433206

RESUMO

Background and study aims In this study, we evaluated the performance of community hospitals involved in the Dutch quality in endosonography team regarding yield of endoscopic ultrasound (EUS)-guided tissue acquisition (TA) of solid pancreatic lesions using cumulative sum (CUSUM) learning curves. The aims were to assess trends in quality over time and explore potential benefits of CUSUM as a feedback-tool. Patients and methods All consecutive EUS-guided TA procedures for solid pancreatic lesions were registered in five community hospitals between 2015 and  2018. CUSUM learning curves were plotted for overall performance and for performance per center. The American Society of Gastrointestinal Endoscopy-defined key performance indicators, rate of adequate sample (RAS), and diagnostic yield of malignancy (DYM) were used for this purpose. Feedback regarding performance was provided on multiple occasions at regional interest group meetings during the study period. Results A total of 431 EUS-guided TA procedures in 403 patients were included in this study. The overall and per center CUSUM curves for RAS improved over time. CUSUM curves for DYM revealed gradual improvement, reaching the predefined performance target (70 %) overall, and in three of five contributing centers in 2018. Analysis of a sudden downslope development in the CUSUM curve of DYM in one center revealed temporary absence of a senior cytopathologist to have had a temporary negative impact on performance. Conclusions CUSUM-derived learning curves allow for assessment of best practices by comparison among peers in a multidisciplinary multicenter quality improvement initiative and proved to be a valuable and easy-to-interpret means to evaluate EUS performance over time.

10.
Psychiatry Res ; 185(1-2): 54-9, 2011 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-20510466

RESUMO

Although many researchers agree that working memory (WM) impairments are a core symptom of schizophrenia, it remains unclear how the disturbances on specific WM components relate to one another. In this study, we presented a Delayed-Matching-To-Sample task to 24 schizophrenia patients and 24 healthy controls, matched on demographical variables. Verbal and visuospatial WM performance was investigated with pseudowords and Chinese characters as stimuli, respectively. Processing demands (maintenance and manipulation, measured with delay and mental rotation) were low or high. Reaction time and accuracy were recorded. All experimental factors had significant effects. In general, patients were slower and less accurate than controls. Patients were especially slower on verbal tasks but they were not less accurate. Accuracy differences did not increase when either maintenance or manipulation demands increased alone but they did when both maintenance and manipulation demands increased simultaneously. These findings indicate that performance impairment in patients was non-specific and that no specific deficit of any WM component was observed.


Assuntos
Transtornos da Memória/etiologia , Memória de Curto Prazo/fisiologia , Esquizofrenia/complicações , Adulto , Análise de Variância , Estudos de Casos e Controles , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Testes Neuropsicológicos , Reconhecimento Visual de Modelos , Estimulação Luminosa , Tempo de Reação/fisiologia , Percepção Espacial/fisiologia , Comportamento Verbal
11.
J Med Cases ; 12(7): 288-290, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-34434474

RESUMO

Cervical myomas are benign tumors originating from cervical muscle tissue with a very rare incidence of only about 8% of all myomas. The surgical approach depends on the position of cervical myoma. This case report discusses a 44-year-old woman who complained of a lump discharge from her birth canal 6 months ago, and currently discharging from her vagina. We performed vaginal myomectomy, and the cervical myoma measuring 8 × 8 × 6 cm with solid consistency was removed. We continued with total vaginal hysterectomy. Post-operative recovery was progressing well. The histopathology report was consistent with leiomyoma. Large prolapsed cervical myoma can be disturbing and discomforting for many patients. It is relatively rare and can be successfully removed vaginally with minimal morbidity.

12.
Obstet Gynecol ; 138(4): 633-646, 2021 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-34623076

RESUMO

OBJECTIVE: To evaluate the associations of depressive symptoms and antidepressant use during pregnancy with the risks of preterm birth, low birth weight, small for gestational age (SGA), and low Apgar scores. DATA SOURCES: MEDLINE, EMBASE, ClinicalTrials.gov, and PsycINFO up to June 2016. METHODS OF STUDY SELECTION: Data were sought from studies examining associations of depression, depressive symptoms, or use of antidepressants during pregnancy with gestational age, birth weight, SGA, or Apgar scores. Authors shared the raw data of their studies for incorporation into this individual participant data meta-analysis. TABULATION, INTEGRATION, AND RESULTS: We performed one-stage random-effects meta-analyses to estimate odds ratios (ORs) with 95% CIs. The 215 eligible articles resulted in 402,375 women derived from 27 study databases. Increased risks were observed for preterm birth among women with a clinical diagnosis of depression during pregnancy irrespective of antidepressant use (OR 1.6, 95% CI 1.2-2.1) and among women with depression who did not use antidepressants (OR 2.2, 95% CI 1.7-3.0), as well as for low Apgar scores in the former (OR 1.5, 95% CI 1.3-1.7), but not the latter group. Selective serotonin reuptake inhibitor (SSRI) use was associated with preterm birth among women who used antidepressants with or without restriction to women with depressive symptoms or a diagnosis of depression (OR 1.6, 95% CI 1.0-2.5 and OR 1.9, 95% CI 1.2-2.8, respectively), as well as with low Apgar scores among women in the latter group (OR 1.7, 95% CI 1.1-2.8). CONCLUSION: Depressive symptoms or a clinical diagnosis of depression during pregnancy are associated with preterm birth and low Apgar scores, even without exposure to antidepressants. However, SSRIs may be independently associated with preterm birth and low Apgar scores. SYSTEMATIC REVIEW REGISTRATION: PROSPERO, CRD42016035711.


Assuntos
Antidepressivos/efeitos adversos , Depressão/tratamento farmacológico , Complicações na Gravidez/tratamento farmacológico , Resultado da Gravidez/epidemiologia , Adulto , Antidepressivos/uso terapêutico , Índice de Apgar , Peso ao Nascer , Depressão/epidemiologia , Feminino , Idade Gestacional , Humanos , Recém-Nascido de Baixo Peso , Recém-Nascido , Recém-Nascido Pequeno para a Idade Gestacional , Gravidez , Complicações na Gravidez/epidemiologia , Nascimento Prematuro/epidemiologia , Inibidores Seletivos de Recaptação de Serotonina/efeitos adversos
13.
J Exp Med ; 142(4): 1029-34, 1975 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-1176888

RESUMO

In the course of studying the nature of mononuclear cellular infiltrates in tissue sections of human kidney it was noted that indicator sheep erythrocytes densely coated with the third component of complement (C3) specifically adhered to all of the glomeruli in the tissue sections. The deposition of complement (C) within the glomerulus is a feature of many immunologically related renal diseases (1,2), yet the precise mechanism by which C is deposited remains unexplained. We feel that this observation, suggesting the presence of a receptor for C, is, therefore, of particular interest.


Assuntos
Sítios de Ligação de Anticorpos , Complemento C3 , Proteínas do Sistema Complemento , Glomérulos Renais/imunologia , Animais , Complexo Antígeno-Anticorpo , Eritrócitos/imunologia , Cobaias , Humanos , Técnicas In Vitro , Ovinos
14.
J Exp Med ; 127(5): 967-82, 1968 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-5655105

RESUMO

Rabbit IgM anti-Forssman antibody was highly purified and the subunits obtained on reduction and alkylation were labeled radioactively and isolated by two different and unrelated methods. In both cases the subunits were found to have a molecular weight of about 90,000, based on their behavior on density gradient centrifugation and gel filtration, and evidence is given that they contained one light and one heavy chain. The subunits bound only weakly to sheep erythrocyte stroma, and only half could be shown to possess antigen specific sites. The data are consistent with the concept that each anti-Forssman IgM molecule has five effective binding sites, but it is uncertain whether the ineffectiveness of the remaining five H-L chain pairs is inherent in the structure of the IgM molecule or an artifact due to the isolation procedure. Intact IgM anti-Forssman antibody binds very firmly to structures containing multiple repeating antigen sites, and it appears that this is due to the presence of multiple binding sites on the molecule.


Assuntos
Imunoglobulina M/análise , Alquilação , Animais , Sítios de Ligação , Centrifugação com Gradiente de Concentração , Cromatografia em Gel , Eritrócitos/imunologia , Isótopos de Iodo , Peso Molecular , Oxirredução , Coelhos , Ovinos , Ultracentrifugação
15.
J Exp Med ; 194(11): 1609-16, 2001 Dec 03.
Artigo em Inglês | MEDLINE | ID: mdl-11733575

RESUMO

We studied complement 1 inhibitor (C1-INH) as an inhibitor of the alternative complement pathway. C1-INH prevented lysis, induced by the alternative complement pathway, of paroxysmal nocturnal hemoglobinuria (PNH) erythrocytes in human serum. It inhibited the binding of both factors B and C3 to PNH and rabbit erythrocytes and blocked the ability of factor B to restore alternative-pathway function in factor B-depleted serum. C1-INH did not bind to factors B or D but did bind to immobilized C3b and cobra venom factor (CVF), a C3b analogue. C1-INH prevented factor B from binding to CVF-coated beads and dissociated bound factor B from such beads. Factor B and C1-INH showed cross competition in binding to CVF-coated beads. Factor D cleaved factor B into Bb and Ba in the presence of C3b. Cleavage was markedly inhibited when C3b was preincubated with C1-INH. C1-INH inhibited the formation of CVFBb and decreased the C3 cleavage. Removal of C1-INH from serum, in the presence of Mg-EGTA with an anti-C1-INH immunoabsorbant, markedly increased alternative-pathway lysis. C1-INH interacts with C3b to inhibit binding of factor B to C3b. At physiologic concentrations, it is a downregulator of the alternative pathway convertase.


Assuntos
Proteínas Inativadoras do Complemento 1/imunologia , Complemento C3b/imunologia , Fator B do Complemento/imunologia , Fator D do Complemento/imunologia , Via Alternativa do Complemento/imunologia , Glicoproteínas/imunologia , Hemoglobinúria Paroxística/imunologia , Absorção , Animais , Proteínas Inativadoras do Complemento 1/metabolismo , Proteínas Inativadoras do Complemento 1/farmacologia , C3 Convertase da Via Alternativa do Complemento , Complemento C3b/metabolismo , Fator B do Complemento/metabolismo , Fator D do Complemento/metabolismo , Proteínas Inativadoras do Complemento/imunologia , Proteínas Inativadoras do Complemento/metabolismo , Ácido Egtázico/farmacologia , Venenos Elapídicos/imunologia , Venenos Elapídicos/metabolismo , Eritrócitos/efeitos dos fármacos , Eritrócitos/imunologia , Eritrócitos/metabolismo , Glicoproteínas/metabolismo , Glicoproteínas/farmacologia , Hemoglobinúria Paroxística/sangue , Hemólise/efeitos dos fármacos , Hemólise/imunologia , Humanos , Microesferas , Fragmentos de Peptídeos/metabolismo , Coelhos , Sefarose
16.
J Exp Med ; 134(1): 176-87, 1971 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-4997584

RESUMO

In vitro studies were performed utilizing sera from a strain of guinea pigs with a total absence of hemolytically active C4. Previous studies in these animals have demonstrated normal complement-dependent inflammatory reactions, suggesting that they are able to bypass their deficiency of C4. In vitro studies with C4-deficient serum also indicate normal activation of late-acting C components. Thus, endotoxin was capable of fixing normal amounts of the late components of complement (C3-9) in these sera, but did not fix C1 and C2. Antigen-antibody complexes fixed both early and late components of complement, although components beyond C4 were fixed less efficiently than in normal sera. Therefore, both in vivo and in vitro evidence indicates that the C4-deficient guinea pigs possess an alternate pathway for activation of late-acting complement components. Antigenic analysis of C4-deficient serum utilizing both guinea pig anti-C4 antibody and rabbit anti-C4 antibody suggests an absolute deficiency of C4-like molecules. Sera from animals with C4-deficiency were found to have one-half the normal level of C2. Sera from five of eight animals tested had 10-20% normal C1 activity. C3-9 assayed as a complex was normal.


Assuntos
Proteínas do Sistema Complemento , Imunidade , Síndromes de Imunodeficiência/imunologia , Animais , Anticorpos , Complexo Antígeno-Anticorpo , Antígenos , Atividade Bactericida do Sangue , Testes de Fixação de Complemento , Endotoxinas , Escherichia coli/imunologia , Cobaias , Imunodifusão , Síndromes de Imunodeficiência/genética , Coelhos , Albumina Sérica , Zimosan
17.
J Exp Med ; 134(1): 162-75, 1971 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-4254163

RESUMO

Guinea pigs with a genetically determined total deficiency of the fourth component of complement have been studied for various in vivo immunological functions. Passive cutaneous anaphylaxsis, contact and delayed hypersensitivity, and the cellular exudative response to a foreign body were normal. These animals also have normal direct and reverse passive Arthus reactions which suggest that they possess a mechanism to bypass C4 and directly activate late-acting complement components. This would appear to be an unequivocal demonstration of an alternate pathway in the complement sequence. Immune clearance of guinea pig erythrocytes sensitized with rabbit antibody was impaired in the deficient animals. Antibody production in C4-deficient animals was impaired for two of the three antigens studied.


Assuntos
Proteínas do Sistema Complemento , Imunidade , Síndromes de Imunodeficiência/imunologia , Animais , Anticorpos , Reação de Arthus/imunologia , Dinitrofenóis , Eritrócitos/imunologia , Feminino , Corpos Estranhos/imunologia , Cobaias , Hipersensibilidade Tardia/imunologia , Hipersensibilidade Imediata/imunologia , Síndromes de Imunodeficiência/genética , Masculino , Ovalbumina , Anafilaxia Cutânea Passiva , Coelhos , Albumina Sérica
18.
J Exp Med ; 162(3): 877-89, 1985 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-3897448

RESUMO

The mechanism was sought by which bactericidal IgG for E. coli 0111 (strain 12015) increases the bactericidal efficiency of C5b-9. IgG did not affect the distribution of C3 deposition on the O-Ag capsule and the outer membrane of 12015, suggesting that bactericidal IgG was not directing complement activation to different sites on the bacterial surface. However, one-fifth of the C3 that was deposited in the presence of IgG attached covalently to the antibody molecule. Covalent complexes between purified C3b and IgG were prepared in order to study the role of C3b-IgG in the bactericidal reaction. 8-10-fold less C3b-IgG than IgG was necessary to sensitize 12015 for serum killing. When aggregates were eliminated from the C3b-IgG and IgG preparations by sucrose density gradient ultracentrifugation, C3b-IgG remained three- to fourfold more effective than IgG on a molecule-for-molecule bound basis in mediating the serum bactericidal reaction. These results suggest that formation of C3b-IgG during the serum bactericidal reaction is critical for killing, and have important implications for the development of effective bactericidal vaccines.


Assuntos
Anticorpos Antibacterianos/imunologia , Atividade Bactericida do Sangue , Complemento C3b/imunologia , Escherichia coli/imunologia , Imunoglobulina G/imunologia , Centrifugação com Gradiente de Concentração , Complemento C3b/metabolismo , Via Alternativa do Complemento , Humanos , Imunoglobulina G/metabolismo
19.
J Exp Med ; 165(2): 572-7, 1987 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-2434597

RESUMO

The affected E of two patients with paroxysmal nocturnal hemoglobinuria (PNH) were enriched by lysing the unaffected, normal E with anti-human decay-accelerating factor (DAF) and guinea pig serum. The membranes of the unlysed, DAF-deficient cells (PNH-E) were dissolved and examined by SDS-PAGE and immunoblotting using an antiserum to homologous restriction factor (HRF). Whereas the 65 kD complement regulatory protein was readily detectable in the normal controls, it was completely lacking in both samples of PNH-E membranes. Functional studies likewise indicated the absence of HRF activity from PNH-E. When radiolabeled, isolated HRF protein was offered to PNH-E, it became firmly attached to the cell. Approximately 1,000 molecules of HRF per cell reduced the characteristic susceptibility of these cells to reactive lysis by C5b-9 to nearly normal levels. The results suggest that HRF, which is known to control the action of C8 and C9 on normal human E membranes, is deficient in PNH, as well as acetylcholinesterase and DAF.


Assuntos
Proteínas Sanguíneas/deficiência , Antígenos CD59 , Proteínas de Transporte , Membrana Eritrocítica/metabolismo , Hemoglobinúria Paroxística/sangue , Proteínas de Membrana/imunologia , Proteínas Sanguíneas/imunologia , Proteínas Sanguíneas/fisiologia , Antígenos CD55 , Separação Celular , Proteínas Inativadoras do Complemento , Hemólise , Humanos , Soros Imunes/farmacologia , Proteínas de Membrana/deficiência , Proteínas de Membrana/fisiologia
20.
J Exp Med ; 141(4): 736-52, 1975 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-1168690

RESUMO

When L cells were treated with anti-L-cell antibody in medium containing heat-inactivated fetal calf serum, nucleoside uptake and cell growth were stimulated. The response was markedly increased when fresh, unheated sera from calves, guinea pigs, humans, mice, or rabbits were also present. The factors in unheated serum responsible for the enhancement of immunostimulation were studied. Using low concentrations of sera deficient in various complement (C) components and low concentrations of antibody no augmentation of immunostimulation was seen with Clr-deficient human serum, C2-deficient human serum, C2,4-deficient human serum, C4-deficient guinea pig serum, C3-C9-depleted guinea pig serum (by administration of cobra venom factor to animals), but stimulation was observed with C5-deficient human serum, C5-deficient mouse serum, and C6-deficient rabbit serum. When the concentration of anti-serum was raised, however, augmentation was observed with C4-deficient guinea pig serum. Thus, at low concentrations of antiserum enhancement appeared to occur through the classical C pathway, whereas at high concentrations of antibody either the classical or alternate C pathways appeared to be involved. Stimulation was specifically restored by purified C2 in C2-deficient serum and by C3 in C3-C9-deficient serum. Under the usual reaction conditions consumption of guinea pig C component C4 could be demonstrated which provided direct evidence for activation of the classical C pathway under conditions leading to immunostimulation. By immunofluorescence, cells treated with antibody and normal human serum had human C3 deposited at the cell surface. Taken together these observations suggest that C activated through C3 by either the classical or alternate pathways has the potential to enhance nucleoside incorporation into DNA and cell growth of cells exposed to limiting amounts of antibody. Although the mechanism of stimulation is unknown, it is likely to involve a direct effect of C3 at the level of the cell membrane.


Assuntos
Reações Antígeno-Anticorpo , Proteínas do Sistema Complemento , DNA de Neoplasias/biossíntese , Células L/imunologia , Animais , Cálcio , Bovinos/imunologia , Testes Imunológicos de Citotoxicidade , Cabras/imunologia , Cobaias/imunologia , Reação de Imunoaderência , Soros Imunes , Radioisótopos do Iodo , Células L/metabolismo , Magnésio , Microscopia de Fluorescência , Ligação Proteica , Coelhos/imunologia , Timidina/metabolismo , Trítio , Uracila/análogos & derivados , Uracila/metabolismo
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