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INTRODUCTION: Haemophilia B is caused by a deficiency of coagulation factor IX (FIX) and characterized by bleeding in muscles and joints. In the perioperative setting, patients are treated with FIX replacement therapy to secure haemostasis. Targeting of specified FIX levels is challenging and requires frequent monitoring and adjustment of therapy. AIM: To evaluate perioperative management in haemophilia B, including monitoring of FIX infusions and observed FIX levels, whereby predictors of low and high FIX levels were assessed. METHODS: In this international multicentre study, haemophilia B patients with FIX < 0.05 IU mL-1 undergoing elective, minor or major surgical procedures between 2000 and 2015 were included. Data were collected on patient, surgical and treatment characteristics. Observed FIX levels were compared to target levels as recommended by guidelines. RESULTS: A total of 255 surgical procedures were performed in 118 patients (median age 40 years, median body weight 79 kg). Sixty percent of FIX levels within 24 hours of surgery were below target with a median difference of 0.22 IU mL-1 [IQR 0.12-0.36]; while >6 days after surgery, 59% of FIX levels were above target with a median difference of 0.19 IU mL-1 [IQR 0.10-0.39]. Clinically relevant bleeding complications (necessity of a second surgical intervention or red blood cell transfusion) occurred in 7 procedures (2.7%). CONCLUSION: This study demonstrates that targeting of FIX levels in the perioperative setting is complex and suboptimal, but although this bleeding is minimal. Alternative dosing strategies taking patient and surgical characteristics as well as pharmacokinetic principles into account may help to optimize and individualize treatment.
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Fator IX/uso terapêutico , Hemofilia B/tratamento farmacológico , Hemofilia B/cirurgia , Período Perioperatório , Adulto , Criança , Pré-Escolar , Fator IX/metabolismo , Feminino , Hemofilia B/metabolismo , Hemorragia/etiologia , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Trombose/etiologia , Adulto JovemRESUMO
INTRODUCTION: Patients', parents' and providers' preferences with regard to medical innovations may have a major impact on their implementation. AIM: To evaluate barriers and facilitators for individualized pharmacokinetic (PK)-guided dosing of prophylaxis in haemophilia patients, parents of young patients, and treating professionals by discrete choice experiment (DCE) questionnaire. PATIENTS/METHODS: The study population consisted of patients with haemophilia currently or previously on prophylactic treatment with factor concentrate (n = 114), parents of patients aged 12-18 years (n = 19) and haemophilia professionals (n = 91). DCE data analysis was performed, taking preference heterogeneity into account. RESULTS: Overall, patients and parents, and especially professionals were inclined to opt for PK-guided dosing of prophylaxis. In addition, if bleeding was consequently reduced, more frequent infusions were acceptable. However, daily dosing remained an important barrier for all involved. 'Reduction of costs for society' was a facilitator for implementation in all groups. CONCLUSIONS: To achieve implementation of individualized PK-guided dosing of prophylaxis in haemophilia, reduction of bleeding risk and reduction of costs for society should be actively discussed as they are motivating for implementation; daily dosing is still reported to be a barrier for all groups. The knowledge of these preferences will enlarge support for this innovation, and aid in the drafting of implementable guidelines and information brochures for patients, parents and professionals.
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Comportamento de Escolha , Cálculos da Dosagem de Medicamento , Hemofilia A/prevenção & controle , Modelos Estatísticos , Adolescente , Adulto , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Inquéritos e Questionários , Distribuição Tecidual , Adulto JovemRESUMO
Background: Desmopressin is frequently used perioperatively in persons with nonsevere hemophilia A. However, increase in factor (F)VIII:C after desmopressin use is interindividually highly variable. Tachyphylaxis has only been reported in test setting for persons with hemophilia A, with a remaining response of approximately 70% after a second dose compared with that after a first dose. Objectives: To study tachyphylaxis of FVIII:C response after multiple administration(s) of desmopressin in perioperative persons with nonsevere hemophilia A. Methods: We studied FVIII:C levels after desmopressin before (day 0 [D0]) and on days 1 (D1) and 2 (D2) after surgery in 26 patients of the DAVID and Little DAVID studies. We studied tachyphylaxis by comparing the responses at D1 and D2 with that at D0. We also assessed the reproducibility of the D0 response in comparison to an earlier performed desmopressin test. Results: The median absolute FVIII:C increase was 0.50 IU/mL (0.35-0.74; n = 23) at D0, 0.21 IU/mL (0.14-0.28; n = 17) at D1, and 0.23 IU/mL (0.16-0.30; n = 11) at D2. The median percentage of FVIII increase after the second administration (D1) compared with the first (D0) was 42.9% (29.2%-52.5%; n = 17) and that of the third (D2) compared with the first (D0) was 36.4% (23.7%-46.9%; n = 11). The FVIII:C desmopressin response at D0 was comparable with the desmopressin test response in 74% of the patients. Conclusion: Tachyphylaxis in the surgical setting was considerably more pronounced than previously reported, with FVIII:C at D1 and D2 of 36% to 43% of the initial response. Our results may have important implications for monitoring repeated desmopressin treatment when used perioperatively.
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Currently, there is no consensus on the optimal management to prevent postpartum hemorrhage (PPH) in hemophilia carriers. We aimed to evaluate peripartum management strategies in relation to maternal and neonatal bleeding outcomes by performing an extensive database search up to August 2020. Seventeen case-reports/series and 11 cohort studies were identified of overall 'poor' quality describing 502 deliveries. The PPH incidence in the individual patient data was 63%; 44% for those women receiving prophylaxis to correct coagulation and 77% for those without (OR 0.23, CI 0.09-0.58) and in cohort data 20.3% (26.8% (11/41) vs. 19.4% (55/284) (OR: 1.53, 95% CI: 0.72-3.24), respectively. Peripartum management strategies mostly consisted of clotting factor concentrates, rarely of desmopressin or plasma. Tranexamic acid appears promising in preventing secondary PPH, but was not used consistently. Neonatal bleeding was described in 6 affected male neonates, mostly after instrumental delivery or emergency CS, but insufficient information was provided to reliably investigate neonatal outcome in relation to management. The high PPH risk seems apparent, at most mildly attenuated by prophylactic treatment. Prospective cohort studies are needed to determine the optimal perinatal management in hemophilia.
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Hemofilia A/complicações , Hemorragia/etiologia , Complicações Hematológicas na Gravidez/etiologia , Antifibrinolíticos/uso terapêutico , Fatores de Coagulação Sanguínea/uso terapêutico , Parto Obstétrico , Feminino , Hemofilia A/terapia , Hemorragia/terapia , Humanos , Recém-Nascido , Período Periparto , Hemorragia Pós-Parto/etiologia , Hemorragia Pós-Parto/terapia , Gravidez , Complicações Hematológicas na Gravidez/terapia , Ácido Tranexâmico/uso terapêuticoRESUMO
INTRODUCTION: Haemophilia is a congenital bleeding disorder mainly affecting males. To prevent bleeding, patients need to perform regular intravenous injections (prophylaxis) throughout life. Non-adherence often occurs. Problems with acceptance or self-management appear to be the main reasons for non-adherence in haemophilia. The aim of this study was to test the feasibility and effects of two interventions focussed on acceptance (face-to-face) and self-management (online). METHODS: Patients with severe haemophilia and acceptance or self-management problems were eligible. The face-to-face group intervention was based on Acceptance and Commitment Therapy (ACT) (8 sessions/6 months, target N = 8 participants). The online intervention was based on a successful online programme in rheumatoid arthritis (5-8 modules/2 months, target N = 8). Both interventions were designed according to the MRC framework in collaboration with the patient society and experts. We compared adherence (VERITAS-Pro, optimum 0), quality of life (SF-36, optimum 100) and illness perception (BIPQ, optimum 0) before start (T0) and after 2 months (T2). Feasibility criteria were as follows: completion of training by > 50% of participants and ability to collect at least 80% of outcome parameters. RESULTS: The face-to-face intervention was feasible (89% enrolment and recruitment, 100% retention). One hundred percent of the outcome parameters was collected. Results were promising: although adherence (VERITAS-Pro) was stable (from 64 to 62 points), quality of life (SF-36) showed a clinically relevant improvement (> 5 points) in five of eight domains. Illness perception (BIPQ) showed a clinically relevant increase from 47 to 39 points. Patient evaluation was positive. The online intervention, however, was infeasible: enrolment was only 20% (6/30). Only three patients signed informed consent (recruitment 10%), and none completed more than one module (retention 0%). Consequently, the online intervention was terminated. CONCLUSION: The face-to-face acceptance intervention was considered feasible with promising results. Unfortunately, the online intervention was infeasible and therefore terminated. These findings suggest that adapting effective interventions to other settings does not guarantee success, despite the use of established methodology and patient participation. Population differences (only male participants, congenital disease) could be an explanation for failure of the online intervention in haemophilia despite success in rheumatoid arthritis. TRIAL REGISTRATION: NL55883.041.16.
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Women with Von Willebrand disease (VWD) have an increased risk of developing postpartum hemorrhage (PPH). Our aim is to evaluate peripartum management strategies in relation to maternal and neonatal bleeding complications in VWD. Electronic databases were searched up to January 2019. Seventy-one case-reports and -series and 16 cohort studies were selected, including 811 deliveries. Cohort studies reported primary PPH in 32% and secondary PPH in 13% of the women. The overall primary PPH incidence in the individual patient data was 34%, similar between women who received prophylactic treatment to prevent PPH and those who didn't. Neonatal bleeding events were reported in 4.6% of deliveries. Overall, the available evidence on peripartum management in women with VWD was of low quality. The ongoing high risk for PPH is evident, despite prophylactic treatment, as well as the need for higher quality evidence from larger prospective cohort studies to improve management strategies.
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Hemorragia Pós-Parto/etiologia , Doenças de von Willebrand/complicações , Feminino , Humanos , Período Periparto , GravidezRESUMO
CD44 splice variants have been shown to be involved in metastasis of carcinomas. In addition, the standard form of CD44 has been implicated in metastasis, particularly of melanomas and lymphomas. To investigate this, we have generated a CD44-negative mutant of the highly metastatic murine MDAY-D2 lymphosarcoma. The two CD44 alleles of this diploid cell line were sequentially disrupted by homologous recombination, using isogenic CD44 genomic constructs interrupted by a neomycin or hygromycin resistance-conferring gene. The resulting double knockout (DKO) cells had completely lost the capacity to bind to immobilized hyaluronic acid, but did not differ from MDAY-D2 cells in integrin expression or in vitro growth. Subcutaneous (s.c.) growth potential and metastatic capacity of MDAY-D2 and DKO cells were assessed by s.c. and i.v. injection of the lowest cell dose (10(3) or 10(4), respectively) that gave rise to tumor formation by MDAY-D2 cells in approximately 100% of the mice. Quite unexpectedly, we observed no difference at all in either s.c. growth rate or local invasion into surrounding tissues between MDAY-D2 cells and the CD44-negative DKO cells. Also hematogenous metastasis formation upon i.v. injection was similar: both parental and DKO cells metastasized extensively to the spleen, liver, and bone marrow. We conclude that, at least for these MDAY-D2 lymphosarcoma cells, the standard form of CD44 is dispensable for tumor growth and metastasis. Our results show that targeted disruption of genes in tumor cells is a feasible approach to study their role in tumorigenesis and metastasis.
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Receptores de Hialuronatos/fisiologia , Linfoma não Hodgkin/patologia , Metástase Neoplásica/patologia , Animais , Sequência de Bases , Adesão Celular/fisiologia , Divisão Celular/fisiologia , Enzimas Imobilizadas/metabolismo , Ácido Hialurônico/metabolismo , Injeções Subcutâneas , Integrinas/biossíntese , Camundongos , Dados de Sequência Molecular , Mutação/fisiologia , Células Tumorais Cultivadas/citologiaRESUMO
Essentials Factor IX (FIX) dosing using body weight frequently results in under and overdosing during surgery. We aimed to establish a population pharmacokinetic (PK) model describing the perioperative FIX levels. Population PK parameter values for clearance and V1 were 284 mL h-170 kg-1 and 5450 mL70 kg-1. Perioperative PK parameters differ from those during non-surgical prophylactic treatment. SUMMARY: Background Hemophilia B is a bleeding disorder characterized by a deficiency of coagulation factor IX (FIX). In the perioperative setting, patients receive FIX concentrates to ensure hemostasis. Although FIX is usually dosed according to bodyweight, under- and overdosing occurs frequently during surgery. Aim The objective was to quantify and explain the interpatient variability of perioperatively administered plasma-derived (pd) and recombinant (r) FIX concentrates. Methods Data were collected from 118 patients (median age, 40 years [range, 0.2-90]; weight, 79 kg [range, 5.3-132]) with moderate (28%) or severe hemophilia B (72%), undergoing 255 surgical procedures. Population pharmacokinetic (PK) parameters were estimated using nonlinear mixed-effect modeling in NONMEM. Results Measured perioperative FIX level vs. time profiles were adequately described using a three-compartment PK model. For a typical 34-year-old patient receiving rFIX, clearance (CL), intercompartmental clearance (Q2, Q3), distribution volume of the central compartment (V1) and peripheral compartments (V2, V3) plus interpatient variability (%CV) were: CL, 284 mL h-170 kg-1 (18%); V1, 5450 mL70 kg-1 (19%); Q2, 110 mL h-170 kg-1; V2, 4800 mL70 kg-1; Q3, 1610 mL h-170 kg-1; V3, 2040 mL70 kg-1. From 0.2 years, CL and V1 decreased 0.89% and 1.15% per year, respectively, until the age of 34 years. Patients receiving pdFIX exhibited a lower CL (11%) and V1 (17%) than patients receiving rFIX. Interpatient variability was successfully quantified and explained. Conclusions The estimated perioperative PK parameters of both pdFIX and rFIX are different from those reported for prophylactic treatment. The developed model may be used to apply PK-guided dosing of FIX concentrates during surgery.
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Fator IX/farmacocinética , Hemofilia B/sangue , Hemofilia B/tratamento farmacológico , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Fatores de Coagulação Sanguínea , Testes de Coagulação Sanguínea , Peso Corporal , Criança , Pré-Escolar , Estudos de Coortes , Hemofilia B/cirurgia , Humanos , Lactente , Cooperação Internacional , Pessoa de Meia-Idade , Proteínas Recombinantes/farmacocinética , Adulto JovemRESUMO
BACKGROUND: The Rho GTPases Rho, Rac, and Cdc42 regulate the organization of the actin cytoskeleton by interacting with multiple, distinct downstream effector proteins. Cdc42 controls the formation of actin bundle-containing filopodia at the cellular periphery. The molecular mechanism for this remains as yet unclear. RESULTS: We report here that Cdc42 interacts with IRSp53/BAP2 alpha, an SH3 domain-containing scaffold protein, at a partial CRIB motif and that an N-terminal fragment of IRSp53 binds, via an intramolecular interaction, to the CRIB motif-containing central region. Overexpression of IRSp53 in fibroblasts leads to the formation of filopodia, and both this and Cdc42-induced filopodia are inhibited by expression of the N-terminal IRSp53 fragment. Using affinity chromatography, we have identified Mena, an Ena/VASP family member, as interacting with the SH3 domain of IRSp53. Mena and IRSp53 act synergistically to promote filopodia formation. CONCLUSION: We conclude that the interaction of Cdc42 with the partial CRIB motif of IRSp53 relieves an intramolecular, autoinhibitory interaction with the N terminus, allowing the recruitment of Mena to the IRSp53 SH3 domain. This IRSp53:Mena complex initiates actin filament assembly into filopodia.
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Proteínas de Transporte/metabolismo , Proteínas do Citoesqueleto , Proteínas do Tecido Nervoso/metabolismo , Pseudópodes/metabolismo , Proteína cdc42 de Ligação ao GTP/metabolismo , Células 3T3 , Actinas/metabolismo , Motivos de Aminoácidos , Sequência de Aminoácidos , Animais , Sítios de Ligação , Células CHO , Cricetinae , Células HeLa , Humanos , Camundongos , Proteínas dos Microfilamentos , Dados de Sequência Molecular , Proteínas do Tecido Nervoso/genética , Fragmentos de Peptídeos/metabolismo , Ligação Proteica , Proteínas Recombinantes/metabolismo , Técnicas do Sistema de Duplo-HíbridoRESUMO
Semaphorins and their receptors, plexins, are widely expressed in embryonic and adult tissues. In general, their functions are poorly characterized, but in neurons they provide essential attractive and repulsive cues that are necessary for axon guidance [1-3]. The Rho family GTPases Rho, Rac, and Cdc42 control signal transduction pathways that link plasma membrane receptors to the actin cytoskeleton and thus regulate many actin-driven processes, including cell migration and axon guidance [4-7]. Using yeast two-hybrid screening and in vitro interaction assays, we show that Rac in its active, GTP bound state interacts directly with the cytoplasmic domain of mammalian and Drosophila B plexins. Plexin-B1 clustering in fibroblasts does not cause the formation of lamellipodia, which suggests that Rac is not activated. Instead, it results in the assembly of actin:myosin filaments and cell contraction, which indicates Rho activation. Surprisingly, these cytoskeletal changes are both Rac and Rho dependent. Clustering of a mutant plexin, lacking the Rac binding region, induced similar cytoskeletal changes, and this finding indicates that the physical interaction of plexin-B1 with Rac is not required for Rho activation. Our findings that plexin-B signaling to the cytoskeleton is both Rac and Rho dependent form a starting point for unraveling the mechanism by which semaphorins and plexins control axon guidance and cell migration.
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Actinas/metabolismo , Citoesqueleto/metabolismo , Proteínas de Drosophila , Proteínas do Tecido Nervoso/metabolismo , Receptores de Superfície Celular/metabolismo , Proteínas rac de Ligação ao GTP/metabolismo , Proteínas rho de Ligação ao GTP/metabolismo , Células 3T3 , Sequência de Aminoácidos , Animais , Sítios de Ligação , Drosophila , Ativação Enzimática , Guanosina Trifosfato/metabolismo , Humanos , Camundongos , Dados de Sequência Molecular , Proteínas do Tecido Nervoso/genética , Receptores de Superfície Celular/genética , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes de Fusão/metabolismo , Proteína cdc42 de Ligação ao GTP/metabolismo , Proteínas rac de Ligação ao GTP/antagonistas & inibidores , Proteínas rac de Ligação ao GTP/genéticaRESUMO
BACKGROUND: Phosphatidylinositol 4,5-bisphosphate (PIP(2)) has been implicated in the regulation of the actin cytoskeleton and vesicle trafficking. It stimulates de novo actin polymerization by activating the pathway involving the Wiskott-Aldrich syndrome protein (WASP) and the actin-related protein complex Arp2/3. Other studies show that actin polymerizes from cholesterol-sphingolipid-rich membrane microdomains called 'rafts', in a manner dependent on tyrosine phosphorylation. Although actin has been implicated in vesicle trafficking, and rafts are sites of active phosphoinositide and tyrosine kinase signaling that mediate apically directed vesicle trafficking, it is not known whether phosphoinositide regulation of actin dynamics occurs in rafts, or if it is linked to vesicle movements. RESULTS: Overexpression of type I phosphatidylinositol phosphate 5-kinase (PIP5KI), which synthesizes PIP(2), promoted actin polymerization from membrane-bound vesicles to form motile actin comets. Pervanadate (PV), a tyrosine phosphatase inhibitor, induced comets even in the absence of PIP5KI overexpression. PV increased PIP(2) levels, suggesting that it induces comets by changing PIP(2) homeostasis and by increasing tyrosine phosphorylation. Platelet-derived growth factor (PDGF) enhanced PV-induced comet formation, and these stimuli together potentiated the PIP5KI effect. The vesicles at the heads of comets were enriched in PIP5KIs and tyrosine phosphoproteins. WASP-Arp2/3 involvement was established using dominant-negative WASP constructs. Endocytic and exocytic markers identified vesicles enriched in lipid rafts as preferential sites of comet generation. Extraction of cholesterol with methyl-beta-cyclodextrin reduced comets, establishing that rafts promote comet formation. CONCLUSIONS: Sphingolipid-cholesterol rafts are preferred platforms for membrane-linked actin polymerization. This is mediated by in situ PIP(2) synthesis and tyrosine kinase signaling through the WASP-Arp2/3 pathway. Actin comets may provide a novel mechanism for raft-dependent vesicle transport and apical membrane trafficking.
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Actinas/metabolismo , Proteínas do Citoesqueleto , Proteínas do Tecido Nervoso/metabolismo , Fosfatidilinositol 4,5-Difosfato/metabolismo , Proteínas/metabolismo , Células 3T3 , Proteína 2 Relacionada a Actina , Proteína 3 Relacionada a Actina , Animais , Colesterol/metabolismo , Expressão Gênica , Humanos , Camundongos , Proteínas do Tecido Nervoso/genética , Fosforilação , Fosfotransferases (Aceptor do Grupo Álcool)/genética , Fosfotransferases (Aceptor do Grupo Álcool)/metabolismo , Proteínas/genética , Esfingolipídeos/metabolismo , Tirosina/metabolismo , Proteína da Síndrome de Wiskott-Aldrich , Proteína Neuronal da Síndrome de Wiskott-AldrichRESUMO
UNLABELLED: ESSENTIALS: Targeting of factor VIII values is a challenge during perioperative replacement therapy in hemophilia. This study aims to identify the extent and predictors of factor VIII underdosing and overdosing. Blood group O predicts underdosing and is associated with perioperative bleeding. To increase quality of care and cost-effectiveness of treatment, refining of dosing is obligatory. BACKGROUND: Perioperative administration of factor VIII (FVIII) concentrate in hemophilia A may result in both underdosing and overdosing, leading to respectively a risk of bleeding complications and unnecessary costs. OBJECTIVES: This retrospective observational study aims to identify the extent and predictors of underdosing and overdosing in perioperative hemophilia A patients (FVIII levels < 0.05 IU mL(-1)). PATIENTS AND METHODS: One hundred nineteen patients undergoing 198 elective, minor, or major surgical procedures were included (median age 40 years, median body weight 75 kg). Perioperative management was evaluated by quantification of perioperative infusion of FVIII concentrate and achieved FVIII levels. Predictors of underdosing and (excessive) overdosing were analyzed by logistic regression analysis. Excessive overdosing was defined as upper target level plus ≥ 0.20 IU mL(-1). RESULTS: Depending on postoperative day, 7-45% of achieved FVIII levels were under and 33-75% were above predefined target ranges as stated by national guidelines. A potential reduction of FVIII consumption of 44% would have been attained if FVIII levels had been maintained within target ranges. Blood group O and major surgery were predictive of underdosing (odds ratio [OR] 6.3, 95% confidence interval [CI] 2.7-14.9; OR 3.3, 95% CI 1.4-7.9). Blood group O patients had more bleeding complications in comparison to patients with blood group non-O (OR 2.02, 95% CI 1.00-4.09). Patients with blood group non-O were at higher risk of overdosing (OR 1.5, 95% CI 1.1-1.9). Additionally, patients treated with bolus infusions were at higher risk of excessive overdosing (OR 1.8, 95% CI 1.3-2.4). CONCLUSION: Quality of care and cost-effectiveness can be improved by refining of dosing strategies based on individual patient characteristics such as blood group and mode of infusion.
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Sistema ABO de Grupos Sanguíneos , Coagulação Sanguínea/efeitos dos fármacos , Perda Sanguínea Cirúrgica/prevenção & controle , Coagulantes/administração & dosagem , Fator VIII/administração & dosagem , Hemofilia A/tratamento farmacológico , Assistência Perioperatória/métodos , Hemorragia Pós-Operatória/prevenção & controle , Adulto , Testes de Coagulação Sanguínea , Distribuição de Qui-Quadrado , Criança , Pré-Escolar , Coagulantes/efeitos adversos , Coagulantes/farmacocinética , Esquema de Medicação , Cálculos da Dosagem de Medicamento , Monitoramento de Medicamentos , Fator VIII/efeitos adversos , Fator VIII/farmacocinética , Hemofilia A/sangue , Hemofilia A/complicações , Hemofilia A/diagnóstico , Humanos , Infusões Parenterais , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Países Baixos , Razão de Chances , Hemorragia Pós-Operatória/sangue , Hemorragia Pós-Operatória/etiologia , Estudos Retrospectivos , Fatores de Risco , Resultado do TratamentoRESUMO
The murine CD18 monoclonal antibody (mAb) M18/2 was reported to inhibit lymphoma metastasis [Zahalka, M. A. et al. (1993) J. Immunol. 150, 4466]. To identify the pathways potentially blocked, we studied the effects of M18/2 compared with two new mAb against murine CD18, GAME-46, and -245. Whereas the GAME mAb blocked most Mac-1-mediated interactions, M18/2 had no effect, or even stimulated. The same was true for adhesion of LFA-1 to ICAM-1. To test effects on interactions with different ICAMs, we used L cells transfected with human ICAM-1, -2, and -3. As previously described, mouse LFA-1 does not bind to human ICAM-1 but we show here that mouse LFA-1 does bind to human ICAM-2 and -3. Again, the GAME mAb blocked completely, but M18/2 did not. These results indicate that the LFA-1 binding sites for ICAM-1 and ICAM-2 and -3, although in close vicinity, are distinct. Furthermore, effects of M18/2 on metastasis cannot be ascribed to blocking of any known beta2-integrin activity.
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Antígenos CD/metabolismo , Antígenos de Diferenciação , Antígenos CD18/metabolismo , Moléculas de Adesão Celular/metabolismo , Molécula 1 de Adesão Intercelular/metabolismo , Antígeno-1 Associado à Função Linfocitária/metabolismo , Antígeno de Macrófago 1/metabolismo , Animais , Anticorpos Monoclonais/imunologia , Reações Antígeno-Anticorpo , Sítios de Ligação , Ligação Competitiva , Adesão Celular , Complemento C3b/metabolismo , Epitopos , Fibrinogênio/metabolismo , Gelatina/metabolismo , Humanos , Hibridomas , Linfoma/patologia , Camundongos , Metástase Neoplásica , Testes de Precipitina , Ratos , Especificidade da EspécieRESUMO
Previous trials have demonstrated a clinical and electrophysiological improvement of diabetic peripheral polyneuropathy in diabetic patients treated with cyclandelate at a dosage of 1600 mg/day. Hence, a double-blind randomised trial was started in 16 insulin-dependent diabetic patients presenting with symptoms of neuropathy, an increased vibration perception threshold (VPT), disturbed tendon reflexes at lower limbs and an EMG showing a significantly decreased motor nerve conduction velocity (MCV) of the peroneal nerves. The placebo-treated group and the cyclandelate-treated group were not significantly different regarding age, duration of diabetes and level of metabolic control (measured as total HbA1), which remained unchanged during the year of observation. In the cyclandelate-treated group, pathological sensation improved significantly in 7 of 8 patients. MCV, measured under standardised conditions, increased significantly during the first 6 months of treatment, while mean VPT did not change. In the placebo group 3 of 8 patients showed an improvement of sensation, 3 did not feel any change and 2 worsened. Neither mean MCV nor VPT changed significantly. No severe side effects were observed during the study period.
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Ciclandelato/uso terapêutico , Diabetes Mellitus Tipo 1/complicações , Neuropatias Diabéticas/tratamento farmacológico , Ácidos Mandélicos/uso terapêutico , Adulto , Idoso , Limiar Auditivo/efeitos dos fármacos , Ensaios Clínicos como Assunto , Ciclandelato/efeitos adversos , Método Duplo-Cego , Feminino , Hemoglobinas Glicadas/metabolismo , Humanos , Masculino , Pessoa de Meia-Idade , Distribuição AleatóriaRESUMO
Evaluation of the local haemodynamic changes was performed in 93 patients with untreated reflex sympathetic dystrophy, based upon a simple dynamic vascular examination technique, using 99Tcm-HSA. According to the disease stage, opposite observations were made: in stage I (n = 72) an increase in both blood flow and blood volume was found, in stage II (n = 21) in contrast, both blood flow and blood volume decreased. These findings show that reflex sympathetic dystrophy can be staged according to haemodynamic changes. It is obvious, moreover, that a careful haemodynamic staging is most important for the choice of the right vasoactive treatment; e.g. calcitonin (vasoconstrictive) versus guanethidine (vasodilating).
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Distrofia Simpática Reflexa/diagnóstico por imagem , Agregado de Albumina Marcado com Tecnécio Tc 99m , Calcitonina/uso terapêutico , Hemodinâmica/fisiologia , Humanos , Cintilografia , Distrofia Simpática Reflexa/tratamento farmacológico , Distrofia Simpática Reflexa/fisiopatologiaRESUMO
Ninety-two cryptotetany tests were performed with simultaneous EMG-recording in the M. Interosseus dorsalis I and the M. Opponens pollicis. It was found that, in 21 cases out of 92 (22.8%), exclusively in the M. Interosseus dorsalis I, and in 11 cases out of 92 (11.9%), exclusively in the M. Opponens pollicis, multiplet activity was detected for at least 2 minutes. From this study it appears that, in performing the cryptotetany test, the M. Opponens pollicis is certainly not be preferred to the M. Interosseus dorsalis as the only place of recording. It appears, on the contrary, that simultaneous recording in the M. Interosseus dorsalis I and the M. Opponens pollicis is to be preferred to a recording exclusively in the M. Interosseus dorsalis I. In this way, a not unsignificant number of false negative cryptotetany tests can be avoided.
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Eletromiografia , Tetania/diagnóstico , Adolescente , Adulto , Circulação Sanguínea , Constrição , Feminino , Mãos , Humanos , Masculino , Pessoa de Meia-Idade , Respiração , Tetania/fisiopatologiaRESUMO
The F-wave latency of the deep peroneal nerve in function of leg length was determined in 66 normal persons and 25 diabetic patients with known polyneuropathy. The latencies were measured by stimulating the nerve at the ankle and recording the F-wave at the musculus extensor digitorum brevis using a needle electrode. The leg length was represented by the distance between the spina iliaca anterior superior and the lateral malleolus. The F-wave latencies obtained in diabetic patients were significantly higher than in controls (p less than 0.01). The method is suitable to detect polyneuropathy, especially in early cases where the conventional techniques (determination of the motor and/or sensory latencies and/or conduction velocities at the lower limbs) may still yield normal or borderline values. The upper limits of the normal values of the F-wave latencies in function of leg length is given by a non-linear curve, which can be represented by the equation: F-wave latency (msec) = 14.7 + 47.5 x (leg length in m)2. For practical purposes, the upper limit of the normal value for a given leg length can be readily determined from a latency-length curve.
Assuntos
Neuropatias Diabéticas/fisiopatologia , Nervo Fibular/fisiopatologia , Adulto , Tornozelo/inervação , Ensaios Clínicos como Assunto , Eletromiografia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Condução Nervosa , Tempo de ReaçãoRESUMO
Eleven patients with limited joint mobility and neuropathy were enrolled in a physical therapy program of passive joint mobilization at a rate of two sessions per week. Treatment resulted in a significant improvement in joint mobility after 10 sessions. Further improvement after 20 sessions did not reach the level of statistical significance, although near-normal joint mobility was attained. After completion of therapy, there was a progressive deterioration in joint mobility. No serious adverse effects were noted during treatment. This study provides some evidence that use of physical therapy may result in significant, although temporary, improvement in the mobility of the ankle and foot joints in diabetic patients with limited joint mobility and neuropathy. As limited joint mobility has been associated with the development of abnormally high pressures under the feet, which in turn may contribute to plantar ulceration in the susceptible neuropathic foot, the results indicate that physical therapy may be useful in the prevention of plantar ulceration in diabetic patients with limited joint mobility and neuropathy, although this must be verified by additional research.
Assuntos
Pé Diabético/fisiopatologia , Amplitude de Movimento Articular , Articulações Tarsianas/fisiologia , Articulação do Dedo do Pé/fisiopatologia , Adulto , Feminino , Humanos , Masculino , Articulação Metatarsofalângica/fisiologia , Pessoa de Meia-Idade , Projetos PilotoRESUMO
Pseudodystrophy is a condition that in the past was regarded incorrectly as a kind of reflex sympathetic dystrophy. The difference between both diseases can be ascertained easily by a bone scintigraphy. Other clinical features of pseudodystrophy are discussed. Infrequent presentations of reflex sympathetic dystrophy are described: radial, parcellar, and zonal cases; vertebral localization; and other misleading conditions.
Assuntos
Distrofia Simpática Reflexa , Adolescente , Adulto , Braço/diagnóstico por imagem , Braço/fisiopatologia , Criança , Diagnóstico Diferencial , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Radiografia , Cintilografia , Distrofia Simpática Reflexa/diagnóstico , Distrofia Simpática Reflexa/etiologia , Distrofia Simpática Reflexa/psicologia , Distrofia Simpática Reflexa/terapia , Temperatura CutâneaRESUMO
In the literature there is no unanimity with respect to the diagnosis of reflex sympathetic dystrophy (RSD). Frequently, the diagnosis is established on mere clinical grounds. In our opinion, however, bone scintigraphy is of major importance for the diagnosis. Using this examination, true RSD can be clearly differentiated from other conditions which are incorrectly diagnosed and treated as RSD. If the bone scan is not suggestive of RSD, the clinical picture, radiological examination and vascular scan may lead to the correct diagnosis. This may be a pseudodystrophy, in which a hypovascularization is found right from the start, while in true RSD there is initially a hypervascularization. Other conditions which may be confused with RSD are causalgia, neurotic compulsive postures, hysterical conversion, malingering and even self-mutilation. In the spontaneous course of RSD three phases can be distinguished. Stage I is the warm or hypertrophic phase, stage II the cold or atrophic phase. Per definition the third phase corresponds to stabilization or, in rare instances, to healing. By means of the vascular scan the correct stage can be determined, and the results of treatment evaluated. Finally it should be noted that in children the condition is completely different from true RSD, as it concerns a pseudodystrophy or disuse-related dystrophy. This condition may also be seen in adults and adolescents, usually females. The bone scan is always negative. In this way bone scintigraphy constitutes the means to answer the question as to what RSD is and what it is not. An algorithm for the differential diagnosis is presented.