RESUMO
AIMS: To investigate short- and long-term effects of real-time monitoring medication use combined with short message service (SMS) reminders for missed doses on refill adherence to oral anti-diabetic medication. METHODS: A randomized controlled trial with two intervention groups and one control group involving 161 participants with Type 2 diabetes with suboptimal adherence. For 6 months, participants in the SMS group (n = 56) were monitored and received SMS reminders if they missed their medication. Participants in the non-SMS group (n = 48) were only monitored. The control group (n = 57) was not exposed to any intervention. Primary outcome measure was refill adherence to oral anti-diabetic medication. Multi-level regression analyses were performed to examine intervention effects on adherence between and within groups after 1 and 2 years of follow-up. RESULTS: At baseline, mean refill adherence was comparable between the groups. After 1 year, adherence in the SMS group was significantly higher than in the control group (79.5% vs. 64.5%; P < 0.001) and showed a significant improvement from baseline (+16.3%; P < 0.001). Mean adherence in the non-SMS group reached 73.1% (+7.3%; P < 0.05), but did not differ from the control group (P = 0.06). After 2 years, the improved adherence in the SMS group persisted and remained significantly higher than in the control group (80.4% vs. 68.4%; P < .01), contrary to the non-SMS group whose adherence approached baseline level again (65.5%). CONCLUSIONS: This study shows the long-term effectiveness of real-time medication monitoring combined with SMS reminders in improving refill adherence. This new reminder system can strengthen the self-management of people with diabetes.
Assuntos
Diabetes Mellitus Tipo 2/tratamento farmacológico , Diabetes Mellitus Tipo 2/psicologia , Adesão à Medicação/psicologia , Sistemas de Alerta , Autocuidado/psicologia , Envio de Mensagens de Texto , Administração Oral , Telefone Celular , Monitoramento de Medicamentos , Prática Clínica Baseada em Evidências , Feminino , Seguimentos , Hemoglobinas Glicadas/metabolismo , Humanos , Hipoglicemiantes/uso terapêutico , Masculino , Pessoa de Meia-Idade , Países Baixos , Sistemas de Alerta/tendências , Envio de Mensagens de Texto/tendências , Fatores de TempoRESUMO
Local coagulation activation has been shown to impact both primary tumor growth and metastasis in mice. It is well known that components of the blood clotting cascade such as tissue factor and thrombin play a role in tumor progression by activating cellular receptors and local formation of fibrin. However, whether venous thromboembolism (VTE) or a hypercoagulable state has a direct impact on cancer progression is unknown. Here we have combined an orthotopic murine breast cancer model, using female Nod-SCID mice, with siRNA-mediated silencing of antithrombin (siAT) leading to the induction of a systemic hypercoagulable state. We show that, compared to control siRNA-treated (not experiencing a hypercoagulable state) tumor-bearing mice, siAT treated tumor-bearing mice do not show enhanced tumor growth nor enhanced metastasis. We conclude that, in this murine model for hypercoagulability, induction of a hypercoagulable state does not contribute to breast cancer progression.
Assuntos
Neoplasias da Mama , Trombofilia , Humanos , Feminino , Animais , Camundongos , Antitrombinas , Modelos Animais de Doenças , Xenoenxertos , Camundongos SCID , Trombofilia/genética , Anticoagulantes , Neoplasias da Mama/complicações , Neoplasias da Mama/genética , Antitrombina III/genética , RNA Interferente PequenoRESUMO
BACKGROUND: Cushing's syndrome (CS) is associated with an hypercoagulable state and an increased risk of venous thromboembolism (VTE). Evidence-based guidelines on thromboprophylaxis strategies in patients with CS are currently lacking. We aimed to map the current clinical practice for thromboprophylaxis management in patients with CS across reference centers (RCs) of the European Reference Network on Rare Endocrine Conditions (Endo-ERN), which are endorsed specifically for the diagnosis and treatment of CS. Using the EU survey tool, a primary screening survey, and subsequently a secondary, more in-depth survey were developed. RESULTS: The majority of the RCs provided thromboprophylaxis to patients with CS (n = 23/25), although only one center had a standardized thromboprophylaxis protocol (n = 1/23). RCs most frequently started thromboprophylaxis from CS diagnosis onwards (n = 11/23), and the majority stopped thromboprophylaxis based on individual patient characteristics, rather than standardized treatment duration (n = 15/23). Factors influencing the initiation of thromboprophylaxis were 'medical history of VTE' (n = 15/23) and 'severity of hypercortisolism' (n = 15/23). Low-Molecular-Weight-Heparin was selected as the first-choice anticoagulant drug for thromboprophylaxis by all RCs (n = 23/23). Postoperatively, the majority of RCs reported 'severe immobilization' as an indication to start thromboprophylaxis in patients with CS (n = 15/25). Most RCs (n = 19/25) did not provide standardized testing for variables of hemostasis in the postoperative care of CS. Furthermore, the majority of the RCs provided preoperative medical treatment to patients with CS (n = 23/25). About half of these RCs (n = 12/23) took a previous VTE into account when starting preoperative medical treatment, and about two-thirds (n = 15/23) included 'reduction of VTE risk' as a goal of treatment. CONCLUSIONS: There is a large practice variation regarding thromboprophylaxis management and perioperative medical treatment in patients with CS, even in Endo-ERN RCs. Randomized controlled trials are needed to establish the optimal prophylactic anticoagulant regimen, carefully balancing the increased risk of (perioperative) bleeding, and the presence of additional risk factors for thrombosis.
Assuntos
Síndrome de Cushing , Doenças do Sistema Endócrino , Endometriose , Tromboembolia Venosa , Anticoagulantes/uso terapêutico , Síndrome de Cushing/complicações , Síndrome de Cushing/tratamento farmacológico , Feminino , Humanos , Doenças Raras/tratamento farmacológico , Tromboembolia Venosa/tratamento farmacológico , Tromboembolia Venosa/prevenção & controleRESUMO
Essentials Substitution therapy for von Willebrand (VW) disease leaves mutant VW factor (VWF) unhindered. Presence of mutant VWF may negatively affect phenotypes despite treatment. Inhibition of VWF by allele-specific siRNAs targeting single-nucleotide polymorphisms is effective. Allele-specific inhibition of VWF p.Cys2773Ser improves multimerization. SUMMARY: Background Treatment of the bleeding disorder von Willebrand disease (VWD) focuses on increasing von Willebrand factor (VWF) levels by administration of desmopressin or VWF-containing concentrates. Both therapies leave the production of mutant VWF unhindered, which may have additional consequences, such as thrombocytopenia in patients with VWD type 2B, competition between mutant and normal VWF for platelet receptors, and the potential development of intestinal angiodysplasia. Most cases of VWD are caused by dominant-negative mutations in VWF, and we hypothesize that diminishing expression of mutant VWF positively affects VWD phenotypes. Objectives To investigate allele-specific inhibition of VWF by applying small interfering RNAs (siRNAs) targeting common single-nucleotide polymorphisms (SNPs) in VWF. This approach allows allele-specific knockdown irrespective of the mutations causing VWD. Methods Four SNPs with a high predicted heterozygosity within VWF were selected, and siRNAs were designed against both alleles of the four SNPs. siRNA efficiency, allele specificity and siRNA-mediated phenotypic improvements were determined in VWF-expressing HEK293 cells. Results Twelve siRNAs were able to efficiently inhibit single VWF alleles in HEK293 cells that stably produce VWF. Transient cotransfections of these siRNAs with two VWF alleles resulted in a clear preference for the targeted allele over the untargeted allele for 11 siRNAs. We also demonstrated siRNA-mediated phenotypic improvement of the VWF multimerization pattern of the VWD type 2A mutation VWF p.Cys2773Ser. Conclusions Allele-specific siRNAs are able to distinguish VWF alleles on the basis of one nucleotide variation, and are able to improve a severe multimerization defect caused by VWF p.Cys2773Ser. This holds promise for the therapeutic application of allele-specific siRNAs in dominant-negative VWD.
Assuntos
Mutação , Polimorfismo de Nucleotídeo Único , RNA Interferente Pequeno/genética , Terapêutica com RNAi , Doenças de von Willebrand/terapia , Fator de von Willebrand/genética , Estudos de Viabilidade , Predisposição Genética para Doença , Células HEK293 , Humanos , Fenótipo , Multimerização Proteica , RNA Interferente Pequeno/metabolismo , Doenças de von Willebrand/sangue , Doenças de von Willebrand/genética , Fator de von Willebrand/metabolismoRESUMO
p53 is a potent inhibitor of cell growth and an inducer of apoptosis. During embryonic development, Mdm2 and Mdm4 inhibit the growth suppressive activities of p53. However, whether tight surveillance of p53 activity is required in quiescent cells is unknown. To test this, conditional inactivation of mdm2 and mdm4 was carried out in smooth muscle cells (SMCs). Upon SMC-specific inactivation of mdm2, and not of mdm4, mice rapidly became ill and died. Necropsy showed small intestinal dilation, and histological analyses indicated a severe reduction in the number of intestinal SMCs. Increased p53 levels and activity were detected in the remaining SMCs, and the phenotype was completely rescued on a p53-null background. Interestingly, intestinal SMCs are caspase-3-negative and therefore did not undergo caspase-3-dependent apoptotic cell death. Together, Mdm2, but not Mdm4, prevents accumulation of active p53 in quiescent SMCs and thereby the induction of p53-mediated caspase-3-independent cell death.
Assuntos
Apoptose/fisiologia , Caspase 3/metabolismo , Miócitos de Músculo Liso/metabolismo , Proteínas Proto-Oncogênicas c-mdm2/fisiologia , Proteínas Proto-Oncogênicas/fisiologia , Proteína Supressora de Tumor p53/metabolismo , Ubiquitina-Proteína Ligases/fisiologia , Animais , Apoptose/genética , Caspase 3/genética , Diferenciação Celular/fisiologia , Regulação da Expressão Gênica/fisiologia , Intestino Delgado/metabolismo , Intestino Delgado/patologia , Camundongos , Camundongos Transgênicos , Miócitos de Músculo Liso/patologia , Proteína Supressora de Tumor p53/genéticaRESUMO
Apolipoprotein E3-Leiden (APOE*3-Leiden) transgenic mice have been used to study the effect of different cholesterol-containing diets on the remnant lipoprotein levels and composition and on the possible concurrent development of atherosclerotic plaques. On high fat/cholesterol (HFC) diet, the high expressing lines 2 and 181 developed severe hypercholesterolemia (up to 40 and 60 mmol/liter, respectively), whereas triglyceride levels remained almost normal when compared with regular mouse diet. The addition of cholate increased the hypercholesterolemic effect of this diet. In lines 2 and 181, serum levels of apo E3-Leiden also increased dramatically upon cholesterol feeding (up to 107 and 300 mg/dl, respectively). In these high expressing APOE*3-Leiden transgenic mice, the increase in both serum cholesterol and apo E3-Leiden occurred mainly in the VLDL/LDL-sized fractions, whereas a considerable increase in large, apo E-rich HDL particles also occurred. In contrast to the high expressing lines, the low expressing line 195 reacted only mildly upon HFC diet. On HFC diets, the high expresser APOE*3-Leiden mice developed atherosclerotic lesions in the aortic arch, the descending aorta, and the carotid arteries, varying from fatty streaks containing foam cells to severe atherosclerotic plaques containing cholesterol crystals, fibrosis, and necrotic calcified tissue. Quantitative evaluation revealed that the atherogenesis is positively correlated with the serum level of cholesterol-rich VLDL/LDL particles. In conclusion, with APOE*3-Leiden transgenic mice, factors can be studied that influence the metabolism of remnant VLDL and the development of atherosclerosis.
Assuntos
Apolipoproteínas E/análise , Arteriosclerose/etiologia , Hiperlipoproteinemias/etiologia , Animais , Apolipoproteína E3 , Apolipoproteínas E/genética , Arteriosclerose/patologia , Colesterol na Dieta/administração & dosagem , Feminino , Lipídeos/sangue , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos CBA , Camundongos Transgênicos , Fatores SexuaisRESUMO
Apolipoprotein E3-Leiden (APOE*3-Leiden) transgenic mice have been studied to identify factors modulating chylomicron and VLDL remnant lipoprotein metabolism. Transient elevated levels of VLDL/LDL-sized lipoproteins occurred in these mice with maximal levels during the period of rapid growth (optimum at 45 d of age). After about 100 d of age, serum cholesterol and triglyceride levels stabilized to slightly elevated levels as compared to control mice. The expression of the APOE*3-Leiden transgene was not age-dependent. In young mice the in vivo hepatic production of VLDL-triglycerides was 50% increased as compared to older mice. This is sustained by in vivo VLDL-apo B turnover studies showing increased (75%) VLDL-apo B secretion rates in young mice, whereas the VLDL-apo B clearance rate appeared not to be age dependent. On a high fat/cholesterol diet, females displayed significantly higher cholesterol levels than males (10 versus 7.0 mmol/liter, respectively). Serum levels of VLDL/LDL sized lipoproteins increased upon administration of estrogens, whereas administration of testosterone gave the opposite result. As compared to male mice, in female mice the hepatic VLDL-triglyceride production rate was significantly elevated. Injection of estrogen in males also resulted in increased VLDL-triglyceride production, although not statistically significant. In vivo VLDL-apo B turnover experiments showed that the VLDL secretion rate tended to be higher in females. Although, the fractional catabolic rate of VLDL-apo B is not different between males and females, administration of estrogens in males resulted in a decreased clearance rate of VLDL, whereas administration of testosterone in females resulted in an increased clearance rate of VLDL. The latter presumably due to an inhibiting effect of testosterone on the expression of the APOE*3-Leiden transgene. We conclude that hyperlipidemia in APOE*3-Leiden transgenic mice is strongly affected by age via its effect on hepatic VLDL production rate, whereas gender influences hyperlipidemia by modulating both hepatic VLDL production and clearance rate.
Assuntos
Apolipoproteínas E/genética , Hiperlipoproteinemias/etiologia , Lipoproteínas VLDL/metabolismo , Fatores Etários , Animais , Apolipoproteína E3 , Gorduras na Dieta/administração & dosagem , Feminino , Hormônios Esteroides Gonadais/farmacologia , Humanos , Lipídeos/sangue , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Receptores de LDL/análise , Fatores SexuaisRESUMO
BACKGROUND: Mouse models have become increasingly important in thrombosis research. However, only a limited number of assays are available for assessment of the coagulation system in mouse plasma. OBJECTIVES: To quantify tissue factor-initiated thrombin generation in murine platelet-rich and platelet-free plasma and to develop a test for measurement of resistance to activated protein C (APC) in mouse plasma. METHODS: Thrombin generation was monitored with calibrated automated thrombography (CAT) using a low-affinity fluorogenic substrate for thrombin. RESULTS: To overcome the higher activity of coagulation inhibitors in mouse plasma as compared with human plasma, the reaction temperature was lowered to 33 degrees C and the assay was carried out at a 2-fold higher final plasma dilution (1:3) than commonly used for CAT in human plasma. This increased the endogenous thrombin potential (ETP) 4- to 5-fold and enabled reliable measurement of thrombin generation in both platelet-free and platelet-rich mouse plasma. For the APC resistance measurement, the reaction conditions were further optimized with respect to tissue factor, phospholipid, APC and CaCl(2) concentrations. The test was validated using plasma of mice with different genetic background with respect to the factor V Leiden mutation (FV Leiden). Mice homozygous for FV Leiden had higher APC sensitivity ratios (mean 5.46; 95% CI 4.88-6.03) than heterozygous FV Leiden mice (mean 4.21; 95% CI 3.53-4.89) and than wild-type mice (mean 2.71; 95%CI 2.15-3.27). CONCLUSIONS: We have established reaction conditions for measurement of thrombin generation and APC resistance in mouse plasma. This assay enables evaluation of the coagulation system and the function of the protein C system in mouse models.
Assuntos
Resistência à Proteína C Ativada/genética , Testes de Coagulação Sanguínea/instrumentação , Testes de Coagulação Sanguínea/métodos , Trombina/química , Adulto , Animais , Automação , Plaquetas/metabolismo , Proteínas Sanguíneas/metabolismo , Calibragem , Feminino , Humanos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Protrombina/metabolismo , Sensibilidade e Especificidade , Trombina/metabolismoRESUMO
OBJECTIVE: In vitro studies implicate that the low-density lipoprotein receptor (LDLR)-related protein (LRP) in macrophages has a pro-atherogenic potential. In the present study, we investigated the in vivo role of macrophage specific LRP in atherogenesis independent of its role in the uptake of lipoproteins. METHODS AND RESULTS: We generated macrophage-specific LRP-deficient mice on an apoE/LDLR double-deficient background. Macrophage LRP deletion did not affect plasma cholesterol and triglyceride levels, lipoprotein distribution, and blood monocyte counts. Nevertheless, macrophage LRP deficiency resulted in a 1.8-fold increase in total atherosclerotic lesion area in the aortic root of 18-week-old mice. Moreover, LRP deficiency also resulted in a relatively higher number of advanced lesions. Whereas macrophage and smooth muscle cell content did not differ between LRP-deficient mice and control littermates, a 1.7-fold increase in collagen content and 2.3-fold decrease in relative number of CD3+ T cells were observed in lesions from macrophage specific LRP-deficient mice. CONCLUSIONS: Our data demonstrate that independent of its role in lipoprotein uptake, absence of LRP in macrophages resulted in more advanced atherosclerosis and in lesions that contained more collagen and less CD3+ T cells. In contrast to previous in vitro studies, we conclude that macrophage LRP has an atheroprotective potential and may modulate the extracellular matrix in the atherosclerotic lesions.
Assuntos
Apolipoproteínas E/metabolismo , Aterosclerose/metabolismo , Proteína-1 Relacionada a Receptor de Lipoproteína de Baixa Densidade/metabolismo , Macrófagos/metabolismo , Receptores de LDL/metabolismo , Animais , Apolipoproteínas E/genética , Aterosclerose/genética , Aterosclerose/patologia , Colágeno/metabolismo , Feminino , Regulação da Expressão Gênica/genética , Lipoproteínas/sangue , Proteína-1 Relacionada a Receptor de Lipoproteína de Baixa Densidade/genética , Macrófagos/patologia , Camundongos , Camundongos Knockout , Receptores de LDL/genéticaRESUMO
OBJECTIVE: To survey patients' experiences with the switch from an originator biologic to a biosimilar growth hormone. DESIGN: Questionnaire. METHOD: We developed a questionnaire in which patients were asked about their experiences with the switch from an originator biologic to a biosimilar growth hormone. The questionnaire was distributed to all 207 patients who were switched to the biosimilar in the Radboudumc since April 2014. The following topics were covered: (a) difficulties experienced in switching from originator to biosimilar; (b) patient education; (c) effectiveness of the biosimilar product; (d) possible adverse effects experienced; and (e) experience with application of the new injection system for the biosimilar. RESULTS: The questionnaire was completed by 79 patients (38.1%). Seventy-two percent of the patients indicated that before switching they had no concerns about switching. The other patients did have concerns beforehand, which were related to the different injection system (n=13), possible new adverse effects (n=13) and safety of the biosimilar (n=11). Before the switch was made, all patients had been informed in writing and also individually by endocrinologists and specialised nurses; 93% of the patients was satisfied with the counselling provided by Radboudumc. Concerning use of the new injection system, 95% of the patients indicated that they had received individual training and 98% was confident in using it. Patients rated the process of transition to the biosimilar at the Radboudumc an average of 7.8 (range: 1-10). CONCLUSION: Patients were satisfied with the switch to the biosimilar growth hormone and there were few side-effects. Some minor problems were encountered, but these could be solved. Extensive counselling of patients before switching to prescription of biosimilars proved to be worthwhile. The switch has led to a significant reduction in costs.
Assuntos
Medicamentos Biossimilares , Hormônio do Crescimento Humano/uso terapêutico , Medicamentos Biossimilares/uso terapêutico , Hormônio do Crescimento , Humanos , Satisfação do Paciente , Inquéritos e QuestionáriosRESUMO
Cell proliferation and cell death (either necrosis or apoptosis) are key processes in the progression of atherosclerosis. The tumor suppressor gene p53 is an essential gene in cell proliferation and cell death and is upregulated in human atherosclerotic plaques, both in smooth muscle cells and in macrophages. In the present study, we investigated the importance of macrophage p53 in the progression of atherosclerosis using bone marrow transplantation in APOE*3-Leiden transgenic mice, an animal model for human-like atherosclerosis. APOE*3-Leiden mice were lethally irradiated and reconstituted with bone marrow derived from either p53-deficient (p53(-/-)) or control (p53(+/+)) donor mice. Reconstitution of mice with p53(-/-) bone marrow did not result in any hemopoietic abnormalities as compared with p53(+/+) transplanted mice. After 12 weeks on an atherogenic diet, APOE*3-Leiden mice reconstituted with p53(-/-) bone marrow showed a significant (P=0.006) 2.3-fold increase in total atherosclerotic lesion area as compared with mice reconstituted with p53(+/+) bone marrow. Although likely a secondary effect of the increased lesion area, p53(-/-) transplanted mice also showed significantly more lesion necrosis (necrotic index, 1.1+/-1.3 versus 0.2+/-0.7; P=0.04) and lesion macrophages (macrophage area, 79.9+/-40.0 versus 39.7+/-27.3x10(3) micrometer(2) per section; P=0.02). These observations coincided with a tendency toward decreased apoptosis (terminal deoxynucleotidyl transferase end-labeling [TUNEL]-positive nuclei going from 0.42+/-0.39 to 0.14+/-0.15%, P=0.071), whereas the number of proliferating cells (5'-bromo-2'-deoxyuridine-positive nuclei) was not affected (3.75+/-0.98 versus 4.77+/-2.30%; P=0.59). These studies indicate that macrophage p53 is important in suppressing the progression of atherosclerosis and identify a novel therapeutic target for regulating plaque stability.
Assuntos
Apolipoproteínas E/genética , Arteriosclerose/genética , Macrófagos/metabolismo , Proteína Supressora de Tumor p53/deficiência , Animais , Valva Aórtica/patologia , Apolipoproteína E3 , Apoptose , Arteriosclerose/metabolismo , Arteriosclerose/patologia , Transplante de Medula Óssea , Contagem de Células , Dieta Aterogênica , Modelos Animais de Doenças , Progressão da Doença , Marcação In Situ das Extremidades Cortadas , Macrófagos/patologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Necrose , Índice de Gravidade de Doença , Baço/patologia , Linfócitos T/metabolismo , Linfócitos T/patologia , Proteína Supressora de Tumor p53/genética , Proteína Supressora de Tumor p53/metabolismoRESUMO
BACKGROUND: Coagulation factor VIII (FVIII) is a heavily glycosylated heterodimeric plasma protein that consists of a heavy (domains A1-A2-B) and light chain (domains A3-C1-C2). It has been well established that the clearance of FVIII from the circulation involves mechanisms that are sensitive to the low-density lipoprotein receptor (LDLR) family antagonist receptor-associated protein (RAP), including LDLR-related protein. Because FVIII clearance in the presence of a bolus injection of RAP still occurs fairly efficient, also RAP-independent mechanisms are likely to be involved. OBJECTIVES: In the present study, we investigated the interaction of FVIII with the endocytic lectin asialoglycoprotein receptor (ASGPR) and the physiological relevance thereof. METHODS AND RESULTS: Surface plasmon resonance studies demonstrated that FVIII dose-dependently bound to ASGPR with high affinity (Kd approximately 2 nM). FVIII subunits were different in that only the heavy chain displayed high-affinity binding to ASGPR. Studies employing a FVIII variant that lacks the B domain revealed that FVIII-ASGPR complex assembly is driven by structure elements within the B domain of the heavy chain. The FVIII heavy chain-ASGPR interaction required calcium ions and was inhibited by soluble D-galactose. Furthermore, deglycosylation of the FVIII heavy chain by endoglycosidase F completely abrogated the interaction with ASGPR. In clearance experiments in mice, the FVIII mean residence time was prolonged by the ASGPR-antagonist asialo-orosomucoid (ASOR). CONCLUSIONS: We conclude that asparagine-linked oligosaccharide structures of the FVIII B domain recognize the carbohydrate recognition domains of ASGPR and that an ASOR-sensitive mechanism, most likely ASGPR, contributes to the catabolism of coagulation FVIII in vivo.
Assuntos
Receptor de Asialoglicoproteína/metabolismo , Fator VIII/metabolismo , Animais , Sítios de Ligação , Cálcio/farmacologia , Carboidratos , Fator VIII/química , Fator VIII/farmacocinética , Galactose/farmacologia , Glicosilação , Humanos , Masculino , Taxa de Depuração Metabólica , Camundongos , Camundongos Endogâmicos C57BL , Ligação Proteica/efeitos dos fármacos , Estrutura Terciária de Proteína , Subunidades Proteicas/metabolismo , Ressonância de Plasmônio de SuperfícieRESUMO
BACKGROUND: One of the major determinants of von Willebrand factor (VWF) plasma levels is ABO blood group status, and individuals with blood group O have ~ 25% lower plasma levels. The exact mechanism behind this relationship remains unknown, although effects on clearance have been postulated. OBJECTIVES: To determine whether clearance of VWF is directly dependent on the presence of ABH antigens on VWF. METHODS: Three type 3 von Willebrand disease (VWD) patients were infused with Haemate-P, and the relative loading of VWF with ABH antigens at different time points was measured. VWF-deficient mice were injected with purified plasma-derived human VWF obtained from donors with either blood group A, blood group B, or blood group O. RESULTS: In mice, we found no difference in clearance rate between plasma-derived blood group A, blood group B and blood group O VWF. Faster clearance of the blood group O VWF present in Haemate-P infused in type 3 VWD patients would have resulted in a relative increase in the loading of VWF with A and B antigens over time. However, we observed a two-fold decrease in the loading with A and B antigens in two out of three patients, and stable loading in the third patient. CONCLUSION: There is no direct effect of ABH antigens on VWF in VWF clearance. We demonstrate that, in a direct comparison within one individual, blood group O VWF is not cleared faster than blood group A or blood group B VWF. Clearance differences between blood group O and non-blood group O individuals may therefore be related to the blood group status of the individual rather than the ABH antigen loading on VWF itself.
Assuntos
Sistema ABO de Grupos Sanguíneos/sangue , Doença de von Willebrand Tipo 3/sangue , Fator de von Willebrand/metabolismo , Animais , Biomarcadores/sangue , Combinação de Medicamentos , Fator VIII/administração & dosagem , Feminino , Humanos , Infusões Intravenosas , Masculino , Camundongos Endogâmicos C57BL , Camundongos Knockout , Ligação Proteica , Fatores de Tempo , Doença de von Willebrand Tipo 3/diagnóstico , Doença de von Willebrand Tipo 3/tratamento farmacológico , Fator de von Willebrand/administração & dosagem , Fator de von Willebrand/genéticaRESUMO
Transgenic technologies have provided a series of very useful mouse models to study hyperlipidemia and atherosclerosis. Normally, mice carry cholesterol mainly in the high density lipoprotein (HDL) sized lipoproteins, and have low density lipoprotein (LDL) and very low density lipoprotein (VLDL) cholesterol levels. These low LDL and VLDL levels are due to the very rapid metabolism of remnant clearance in mice, which hamper metabolic studies. In addition, due to the lack of atherogenic lipoproteins, mice will not readily develop atherosclerosis. This situation has changed completely, because to date, most known genes in lipoprotein metabolism have been used in transgenesis to obtain mice in which genes have been silenced or overexpressed. These experiments have yielded many mouse strains with high plasma lipid levels and a greater susceptibility for developing atherosclerosis. One of the most widely used strains are knock-out mice deficient for apoE, which is one of the central players in VLDL metabolism. Subsequently, a wide variety of other transgenic studies involving APOE have been performed elucidating the role of apoE and apoE mutants in lipolysis, remnant clearance, cellular cholesterol efflux and atherogenesis. In addition, the APOE mouse models are excellent tools for the development of gene therapy for hyperlipidemias.
Assuntos
Apolipoproteínas E/fisiologia , Arteriosclerose/fisiopatologia , Hiperlipidemias/fisiopatologia , Camundongos Transgênicos/fisiologia , Animais , Apolipoproteínas E/genética , Arteriosclerose/genética , Modelos Animais de Doenças , Humanos , Hiperlipidemias/genética , Camundongos , Camundongos Transgênicos/genéticaRESUMO
Macrophage scavenger receptors class A (MSR) are thought to play an important role in atherogenesis by mediating the unrestricted uptake of modified lipoproteins by macrophages in the vessel wall leading to foam cell formation. To investigate the in vivo role of the MSR in this process, a transgenic mouse model expressing both isoforms of the human MSR was generated. A 180-kb yeast artificial chromosome (YAC) containing the human MSR gene (MSR1) with 60- and 40-kb flanking sequence at the 5' and 3' end, respectively, was obtained by reducing the size of a 1050-kb YAC by homologous recombination. This 180-kb YAC was microinjected into mouse oocytes. In the resulting transgenic mice, high levels of mRNA for both type I and type II human MSR1 were detected in peritoneal macrophages and trace levels in other organs, known to contain macrophage-derived cells. Using an antibody against the human MSR, the Kupffer cells in the liver were shown to contain the MSR protein. In vivo clearance of acetyl-LDL was not changed in the MSR1-transgenic mice. However, in vitro studies using peritoneal macrophages from the transgenic mice showed a two-fold increased degradation of acetyl-LDL and cholesterolester accumulation concomitant with a four-fold increase in foam cell formation, as compared to wild-type macrophages. Thus, macrophage specific overexpression of the MSR may lead to increased foam cell formation, which is one of the initial and crucial steps in atherogenesis.
Assuntos
Cromossomos Artificiais de Levedura/química , Células Espumosas/metabolismo , Macrófagos Peritoneais/metabolismo , Receptores Imunológicos/genética , Animais , Sequência de Bases , Células Cultivadas , Cromossomos Artificiais de Levedura/genética , Modelos Animais de Doenças , Células Espumosas/patologia , Expressão Gênica , Humanos , Células de Kupffer/química , Lipoproteínas LDL/metabolismo , Lipoproteínas LDL/farmacocinética , Macrófagos Peritoneais/patologia , Camundongos , Camundongos Transgênicos , Dados de Sequência Molecular , Reação em Cadeia da Polimerase , RNA Mensageiro/análise , Receptores Imunológicos/análise , Receptores Depuradores , Receptores Depuradores Classe A , Sensibilidade e Especificidade , Especificidade da Espécie , Distribuição TecidualRESUMO
In APOE*3-Leiden transgenic mice the atherosclerotic lesion size is correlated with plasma cholesterol. In these mice the plasma lipid levels are positively correlated with the relative amount of APOE 3-Leiden protein on the VLDL particle. The plasma cholesterol levels are influenced by diet, age and gender, mainly due to an effect of these factors on VLDL production rate. Excess of APOC1 protein does inhibit the hepatic clearance of VLDL remnant particles, whereas excess of apoE leads to a hampered extra-hepatic lipolysis of VLDL triglyceride.
Assuntos
Apolipoproteínas E/deficiência , Arteriosclerose/metabolismo , Colesterol/sangue , Lipídeos/sangue , Lipoproteínas/metabolismo , Camundongos Transgênicos/metabolismo , Fatores Etários , Animais , Apolipoproteína E3 , Apolipoproteínas C/metabolismo , Feminino , Humanos , Lipoproteínas VLDL/metabolismo , Masculino , Camundongos , Camundongos Transgênicos/genética , Fatores SexuaisAssuntos
Proteína-1 Relacionada a Receptor de Lipoproteína de Baixa Densidade/fisiologia , Inibidor 1 de Ativador de Plasminogênio/sangue , Animais , Proteína-1 Relacionada a Receptor de Lipoproteína de Baixa Densidade/deficiência , Camundongos , Camundongos Knockout , Farmacocinética , Inibidor 1 de Ativador de Plasminogênio/administração & dosagem , Inibidor 1 de Ativador de Plasminogênio/farmacocinéticaRESUMO
BACKGROUND: Poor adherence to oral antidiabetics has a negative influence on glycaemic control in type 2 diabetes patients. Real Time Medication Monitoring (RTMM) combines real time monitoring of patients' medication use with SMS reminders sent only if patients forget their medication, aiming to improve adherence. This study aimed to investigate the effect of these SMS reminders on adherence to oral antidiabetics in patients using RTMM and investigate patients' experiences with RTMM. METHODS: Data were collected in a RCT involving 104 type 2 diabetes patients with suboptimal adherence to oral antidiabetics. Fifty-six patients were randomised to receive SMS reminders if they forgot their medication, 48 patients received no reminders. Primary outcome measure was adherence to oral antidiabetics registered with RTMM, measured as: (1) days without dosing; (2) missed doses; (3) doses taken within predefined standardized time windows. Patients' experiences were assessed with written questionnaires. RESULTS: Over the six-month study period, patients receiving SMS reminders took significantly more doses within predefined time windows than patients receiving no reminders: 50% vs. 39% within a 1-h window (p=0.003) up to 81% vs. 70% within a 4-h window (p=0.007). Reminded patients tended to miss doses less frequently than patients not reminded (15% vs. 19%, p=0.065). Days without dosing were not significantly different between the groups. The majority of patients reported positive experiences with RTMM and SMS reminders. CONCLUSION: RTMM with SMS reminders improves adherence of type 2 diabetes patients, especially the precision with which patients follow their prescribed regimen, and is well accepted by patients. TRIAL REGISTRATION: Netherlands Trial Register NTR1882.
Assuntos
Diabetes Mellitus Tipo 2/tratamento farmacológico , Monitoramento de Medicamentos/instrumentação , Hipoglicemiantes/administração & dosagem , Adesão à Medicação , Cooperação do Paciente , Sistemas de Alerta/estatística & dados numéricos , Envio de Mensagens de Texto/estatística & dados numéricos , Administração Oral , Estudos de Casos e Controles , Feminino , Humanos , Masculino , Pessoa de Meia-IdadeRESUMO
BACKGROUND: Oral estrogen use is associated with changes in plasma levels of many coagulation proteins. OBJECTIVE: To gain more insight into the underlying mechanism of estrogen-induced changes in coagulation. METHODS: Ovariectomized female mice were used to study the impact of oral 17α-ethinylestradiol (EE) on plasma coagulation, hepatic coagulation gene transcript levels, and dependence on estrogen receptor (ER) α and ERß. RESULTS: Ten days of oral EE treatment resulted in significantly reduced plasma activity levels of factor (F)VIII, FXII, combined FII/FVII/FX and antithrombin, whereas FIX activity significantly increased. Regarding hepatic transcript levels, oral EE caused significant decreases in fibrinogen-γ, FII, FV, FVII, FX, FXII, antithrombin, protein C, protein Z, protein Z inhibitor and heparin cofactor II mRNA levels, whereas FXI levels significantly increased and transcript levels of FVIII, FIX, protein S and α(2) -antiplasmin remained unaffected. All EE-induced coagulation-related changes were neutralized by coadministration of the non-specific ER antagonist ICI182780. In addition, ERα-deficient mice lacked the EE-induced changes in plasma coagulation and hepatic transcript profile, whereas ERß-deficient mice responded similarly to non-deficient littermate controls. A crucial role for the ER was further demonstrated by its rapid effects on transcription, within 2.5-5 h after EE administration, suggesting a short chain of events leading to its final effects. CONCLUSIONS: Oral EE administration has a broad impact on the mouse coagulation profile at the level of both plasma and hepatic mRNA levels. The effects on transcription are rapidly induced, mostly downregulatory, and principally mediated by ERα.