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1.
Haemophilia ; 27(3): 470-478, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-33626190

RESUMO

INTRODUCTION: Menorrhagia impacts ~40% of adolescent females, with about half having an underlying bleeding disorder, most commonly von Willebrand Disease (VWD). VWD affects ~1 in 1000 individuals, though many are unaware of their condition. Let's Talk Period (LTP) is an online knowledge translation platform aimed at increasing awareness of bleeding disorders symptoms, with a validated self-administered bleeding assessment tool (Self-BAT). AIM: To evaluate the effectiveness of the LTP high school outreach program in Grade 9 girls' health classes quantitatively, using baseline, post-presentation, and follow-up quiz scores, and qualitatively, with student and teacher feedback forms. METHODS: The 75-minute in-class presentations, developed in alignment with the 2015 Ontario Curriculum for Grade 9 Health and Physical Activity, were led by a haemophilia nurse, clinical research assistant, and undergraduate student from the LTP team. Students completed baseline, post-presentation, and 4-6-week follow-up Kahoot quizzes featuring the same nine questions to evaluate change in knowledge levels and retention. Both student and teacher feedback were collected. RESULTS: There was a significant increase (p < 0.001) from baseline to post-presentation scores, with a significant gain in knowledge, for all questions (p < 0.01). Students found content related to the basics and management of menstruation to be most interesting. Many had constructive feedback on how the presentation method could be improved. On average, the presentations were rated an 8.6 of 10 by students and 8.75 of 10 by teachers. CONCLUSION: The LTP high school outreach program effectively increases student knowledge of menorrhagia and bleeding disorders. It was well-received by students and staff alike.


Assuntos
Menorragia , Doenças de von Willebrand , Adolescente , Exercício Físico , Feminino , Humanos , Menorragia/complicações , Menorragia/terapia , Projetos Piloto , Instituições Acadêmicas , Doenças de von Willebrand/complicações
2.
Pediatr Blood Cancer ; 66(6): e27709, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-30900820

RESUMO

BACKGROUND: In the pediatric population, pathologic bleeding is often challenging to identify. The pediatric bleeding questionnaire (PBQ) was developed as a screening tool for von Willebrand disease (VWD) but was designed to be self-completed by children above 12 years of age. The study objective was to determine whether a modified Self-PBQ could be completed by 8- to 12-year-old children with adult assistance. PROCEDURE: The initial phase involved seven children who underwent cognitive debriefing to identify problems in the questionnaire, resulting in modifications to wording and response options. In phase 2, children completed the modified Self-PBQ independently or with assistance from their parent at five Canadian treatment centers. Parents filled out the Self-PBQ separately to serve as a comparison. Bleeding scores derived from the child self-report were compared to those of the parent proxy. RESULTS: Twenty-nine out of 31 patient/parent pairs successfully completed the Self-PBQ. Child and parent scores demonstrated a high level of agreement with an intraclass correlation (ICC) of 0.825. In the age subgroup analysis, the ICC was 0.834 and 0.824 for the 8- to 9-year-old and 10- to 12-year-old groups, respectively. The ICC was also determined in children with type 1 VWD (ICC = 0.829) versus those with more severe bleeding disorders (ICC = 0.802). Thus, age and disease severity had no significant effect on degree of agreement. CONCLUSIONS: Our study shows that agreement was maintained even in younger children aged 8-9 years and in children with varying bleeding phenotypes. This supports the administration of the modified Self-PBQ to 8- to 12-year-old children.


Assuntos
Hemorragia/diagnóstico , Programas de Rastreamento/métodos , Instituições Acadêmicas/estatística & dados numéricos , Autorrelato , Doenças de von Willebrand/diagnóstico , Criança , Feminino , Seguimentos , Hemorragia/complicações , Humanos , Masculino , Prognóstico , Inquéritos e Questionários , Doenças de von Willebrand/complicações
4.
Pediatr Blood Cancer ; 64(10)2017 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-28453185

RESUMO

OBJECTIVE: Our objective was to generate, optimize, and validate a self-administered pediatric bleeding questionnaire (Self-PBQ) as a screening tool for von Willebrand disease (VWD) in children referred to the hematology clinic for the first time. STUDY DESIGN: The Self-PBQ was generated by combining the validated expert-administered PBQ and the International Society on Thrombosis and Hemostasis (ISTH) bleeding assessment tool (BAT). Medical terminology was translated into lay language requiring a grade 4 reading level. In Phase 1, the Self-PBQ was optimized and the level of agreement between the Self-PBQ and the expert-administered PBQ was determined. Phase 2 established the normal range of bleeding scores (BSs) of the Self-PBQ. Phase 3 examined the Self-PBQ as a screening tool for first-time referrals to the hematology clinic. RESULTS: The Self-PBQ is a reliable surrogate for the expert-administered PBQ with an excellent intraclass correlation (ICC) of 0.917. The Self-PBQ was scored with the PBQ and the ISTH-BAT scoring systems, for which its normal BS ranges are -1 to 2 or 0 to 2, respectively. A positive Self-PBQ BS (≥3) had a sensitivity of 78%, a specificity of 37%, a positive predictive value of 0.18, and a negative predictive value of 0.91 for identifying VWD in children being investigated by a hematologist for a bleeding disorder. CONCLUSION: The Self-PBQ generates comparable BSs to the expert-administered PBQ and is a reliable, reasonably sensitive screening tool to incorporate into the assessment of children presenting to a hematologist for the investigation of an inherited bleeding disorder.


Assuntos
Hemorragia , Autorrelato , Inquéritos e Questionários , Doenças de von Willebrand , Adolescente , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Recém-Nascido , Masculino
6.
J Pediatr Hematol Oncol ; 37(4): e220-2, 2015 May.
Artigo em Inglês | MEDLINE | ID: mdl-25411864

RESUMO

We report an 11-month-old boy with severe hemophilia A who had regular exposure to factor VIII (FVIII) intended to reduce the risk of developing an inhibitor. He developed a high-titer inhibitor (peak titer 19 BU) that disappeared within 6 weeks of starting immune tolerance induction (ITI). Anti-FVIII IgG4 peaked briefly compared with anti-FVIII IgG1 and the Bethesda titer. Neither rapid resolution of an inhibitor after prophylaxis nor this behavior of anti-FVIII IgG4 has been previously reported. Transient anti-FVIII IgG4 may be a marker of an attenuated anti-FVIII response induced by prophylactic FVIII therapy.


Assuntos
Fator VIII/imunologia , Hemofilia A/imunologia , Tolerância Imunológica , Imunoglobulina G/sangue , Fator VIII/antagonistas & inibidores , Humanos
7.
Res Pract Thromb Haemost ; 7(3): 100119, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-37065843

RESUMO

Background: Heavy menstrual bleeding (HMB) affects a significant number of women with bleeding disorders and has a negative impact on their quality of life. Objective: This retrospective study examined the management of patients with inherited bleeding disorders who used medical treatments, alone or in combination, for HMB. Methods: Chart review was performed on women attending the Women with Bleeding Disorders Clinic in Kingston, Ontario, between 2005 and 2017. Data collected included patient demographics, the reason for presentation and diagnosis, medical history, treatments, and patient satisfaction. Results: One hundred nine women were included in this cohort. Of these, only 74 (68%) were satisfied with medical management, and only 18 (17%) with first-line therapy. Treatments included combined contraceptives (oral pill, transdermal patch, and vaginal ring), progesterone-only pills, tranexamic acid, 52-mg levonorgestrel intrauterine system (LIUS), depomedroxyprogesterone acetate, and desmopressin, either alone or in combination. Satisfactory control of HMB occurred most often with the LIUS. Conclusion: In this cohort, managed in a tertiary care Women with Bleeding Disorders Clinic, only 68% of patients had successful control of HMB with medical treatment, and a minority were satisfied with first-line therapy. These data clearly highlight the need for additional research, including treatment approaches and novel therapies for this population.

8.
J Thromb Haemost ; 21(4): 880-886, 2023 04.
Artigo em Inglês | MEDLINE | ID: mdl-36696194

RESUMO

BACKGROUND: Bleeding assessment tools are key screening tests used in the evaluation of patients with suspected inherited bleeding disorders. The International Society on Thrombosis and Haemostasis-Scientific and Standardization Committee endorsed Bleeding Assessment Tool (ISTH-BAT) has differing reference ranges for adult males (0-3), adult females (0-5), and children (0-2), reflecting differing bleeding symptoms and exposure to hemostatic challenges in these healthy population subgroups. Age is known to markedly impact bleeding score in individuals with von Willebrand disease. However, the influence of age on bleeding score in healthy adult controls is poorly understood. OBJECTIVES: We aimed to assess variability in ISTH-BAT score with age among healthy control females. METHODS: We used the legacy "Merging Project" dataset of normal healthy controls upon which current ISTH-BAT normal ranges are based. We included women, totaling 646 individuals. The normal range (middle 95th percentile) of total ISTH-BAT and grouped subdomain scores between age quartiles was assessed. RESULTS: The normal range of ISTH-BAT scores increased with age, ranging from 0 to 4 in the youngest quartile (age range, 18-30) to 0 to 6 in the oldest (age range, 52-88). This increased variability with aging was related both to high menorrhagia domain scores in older women and an increase in postprocedural bleeding with accumulated exposure to hemostatic challenges. CONCLUSIONS: Cumulatively, our data highlight that normal aging leads to increased variability in bleeding scores in healthy adult females. Further refinement of the ISTH-BAT with age-adjusted reference ranges may improve the sensitivity and specificity of the tool among females.


Assuntos
Hemostáticos , Trombose , Adulto , Masculino , Criança , Humanos , Feminino , Idoso , Adolescente , Adulto Jovem , Pessoa de Meia-Idade , Idoso de 80 Anos ou mais , Relevância Clínica , Hemorragia/diagnóstico , Envelhecimento , Trombose/diagnóstico , Hemostasia
9.
Blood Adv ; 7(8): 1477-1487, 2023 04 25.
Artigo em Inglês | MEDLINE | ID: mdl-36121439

RESUMO

Type 1 von Willebrand disease (VWD) is associated with a reduction in qualitatively normal von Willebrand factor (VWF). Current diagnostic guidelines only take into consideration the contribution of basal VWF levels, despite a lack of correlation with bleeding severity. Defects in stimulated VWF release, which occurs after hemostatic challenge, may contribute to bleeding in type 1 VWD, but the pathogenic mechanisms are poorly defined. In this study, a layered multiomic approach including messenger RNA (mRNA) and microRNA (miRNA) sequencing was used to evaluate transcriptome-wide differences between type 1 VWD- and control-derived endothelial colony forming cells (ECFCs) during basal and stimulated VWF release. ECFCs from 8 patients with type 1 VWD and 4 other patients were included in this study as controls. VWF protein analysis revealed heterogenous responses to stimulation among type 1 VWD and control ECFCs. During basal VWF release, 64 mRNAs and 7 miRNAs were differentially regulated between type 1 VWD and control ECFCs, and 65 putatively pathogenic miRNA-mRNA interactions were identified. During stimulated VWF release, 190 mRNAs and 5 mRNAs were differentially regulated between type 1 VWD and control ECFCs, and 110 putatively pathogenic miRNA-mRNA interactions were identified. Five gene ontology terms including coagulation, regulation of cell shape, and regulation of cell signaling were also differentially regulated in type 1 VWD ECFCs during stimulated release. To our knowledge, we have shown for the first time that transcriptome-wide differences exist between type 1 VWD and control ECFCs. These differences may contribute to bleeding in type 1 VWD, and further investigation may reveal novel biomarkers and therapeutic targets.


Assuntos
MicroRNAs , Doença de von Willebrand Tipo 1 , Humanos , Doença de von Willebrand Tipo 1/genética , Fator de von Willebrand/metabolismo , Células Endoteliais/metabolismo , Hemorragia , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Perfilação da Expressão Gênica , MicroRNAs/genética
10.
Res Pract Thromb Haemost ; 6(6): e12783, 2022 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-36186104

RESUMO

Background: Hemophilia carriers experience abnormal bleeding symptoms; however, a lack of awareness about this topic coupled with additional knowledge gaps and barriers leads to suboptimal care for this population. Objective: The primary objective was to describe the current knowledge gaps and challenges from the perspective of both hemophilia carriers and their health care providers. Methods: We carried out a mixed methods descriptive study with two population groups between September and December 2020. The hemophilia carrier perspective was obtained through both focus groups and questionnaires, whereas the health care providers perspective obtained via questionnaire sent to the Association of Hemophilia Care Directors of Canada and the Canadian Association of Nurses in Hemophilia Care. Focus groups were analyzed using descriptive thematic analysis and quantitative survey data was also analyzed. Results: Eleven hemophilia carriers participated along with 19 health care providers (11 physicians, eight nurses). Hemophilia carrier focus group discussions identified four areas representing major challenges or knowledge gaps: (1) negative psychosocial impacts; (2) difficulty determining symptom significance; (3) need for self-advocacy; (4) testing concerns. Survey results from both groups were aligned with the most important topics for ongoing education identified as information on abnormal bleeding symptoms, where to seek treatment, and considerations for heavy menstrual bleeding/menstruation. The majority of both study groups believe obligate or potential carriers should have factor levels checked regardless of age if symptoms of abnormal bleeding occur or before an invasive procedure. However, hemophilia carriers were significantly more in favor of genetic testing under the age of consent than health care providers in all scenarios evaluated.

11.
J Thromb Haemost ; 20(7): 1599-1609, 2022 07.
Artigo em Inglês | MEDLINE | ID: mdl-35466528

RESUMO

BACKGROUND: von Willebrand factor (VWF) is synthesized by vascular endothelial cells and megakaryocytes. The VWF propeptide is critical for multimerization and acts as an intra-molecular chaperone for mature VWF in sorting to its storage organelles, Weibel-Palade bodies (WPBs). In the Canadian Type 3 VWD study, almost half of the identified variants were in the VWF propeptide and these were associated with an increased bleeding phenotype. OBJECTIVE: To investigate VWF propeptide variants that cause quantitative von Willebrand disease (VWD) by utilizing patient-derived endothelial colony-forming cells (ECFCs). PATIENTS/METHODS: Endothelial colony-forming cells were isolated from five Type 3 VWD patients from four families with the following variants: (1) homozygous p.Asp75_Gly178del (deletion of exons 4 and 5 deletion; Ex4-5del), (2) homozygous p.Cys633Arg, (3) homozygous p.Arg273Trp, and (4) p.Pro293Glnfs*164 and p.Gln419* inherited in the compound heterozygous state. Additionally, ECFCs were isolated from six family members (two Type 1 VWD, four unaffected). RESULTS: Endothelial colony-forming cells from the Type 3 patient with the compound heterozygous genotype exhibited a true null VWF cellular phenotype, with negligible VWF detected. In contrast, the other three propeptide variants presented a similar expression pattern in homozygous ECFCs where VWF was synthesized but not packaged in WPBs, and variant VWF had an increased association with the endoplasmic reticulum (ER) marker, protein disulfide-isomerase (PDI), indicating an ER-retention phenotype. The biosynthetic phenotype was similar but to a lesser degree in heterozygous ECFCs expressing the non-null variants. CONCLUSION: This study further elucidates the importance of the VWF propeptide in the VWD phenotype using patient-derived cells.


Assuntos
Doença de von Willebrand Tipo 3 , Doenças de von Willebrand , Canadá , Retículo Endoplasmático/metabolismo , Células Endoteliais/metabolismo , Humanos , Doenças de von Willebrand/genética , Fator de von Willebrand/metabolismo
12.
J Thromb Haemost ; 20(10): 2246-2254, 2022 10.
Artigo em Inglês | MEDLINE | ID: mdl-35780487

RESUMO

BACKGROUND: Assessment of bleeding phenotype is critically important in the diagnosis of von Willebrand disease (VWD). Despite advances in bleeding assessment tools (BATs), standardized tools to evaluate bleeding following diagnosis (interim bleeding) are lacking. OBJECTIVES: We assessed the clinical utility of an interim bleeding protocol in a multicenter, international study involving patients with VWD. METHODS: The enrolment ISTH BAT formed the original bleeding score (0 BS). At follow-up, the International Society on Thrombosis and Haemostasis BAT was repeated but included only interval bleeding (Interim BS, 1 BS). Both scores were annualized (0 BS/yr, 1 BS/yr). BS were analyzed by VWD subtype, plasma VWF level, sex, and age. RESULTS: Interim BS discriminated by subtype, with significantly increased 0 BS and 1 BS in patients with type 3 VWD. In patients with type 1 VWD, a positive or negative 0 BS did not predict future bleeding, with similar 1 BS/yr (median 1.0 vs. 0.7, p = .2). Despite significantly higher 0 BS in females with type 1 VWD than males (median 7 vs. 5, p = .0012), 1 BS were not significantly different (median 4 vs. 4, p = .16). While 0 BS were lower in children than adults with type 1 VWD, interim BS were similar (median 5 vs. 3, p = .5; 1BS/yr, median 1 vs. 0.8, p = .7). Interestingly, in those with plasma von Willebrand factor:ristocetin cofactor levels >50 IU/dl, interim BS rates were similar to those 30-50 IU/dl (1 BS/yr 0.8 vs. 1.3, p = .5). CONCLUSION: This study provides both a new approach to longitudinal bleeding assessment and insights into the evolution of bleeding in VWD.


Assuntos
Doença de von Willebrand Tipo 1 , Doença de von Willebrand Tipo 3 , Doenças de von Willebrand , Feminino , Hemorragia/diagnóstico , Humanos , Masculino , Doença de von Willebrand Tipo 1/complicações , Doença de von Willebrand Tipo 1/diagnóstico , Doenças de von Willebrand/complicações , Doenças de von Willebrand/diagnóstico , Fator de von Willebrand
13.
J Thromb Haemost ; 18(3): 593-603, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-31860769

RESUMO

BACKGROUND: Patients with aortic stenosis (AS) can experience bleeding complications including gastrointestinal bleeding from angiodysplastic lesions due to acquired von Willebrand syndrome. Studies have pointed to a role for von Willebrand factor (VWF) in angiogenesis. OBJECTIVE: The objective of this study was to assess VWF defects in AS patients over time and the impact on angiogenesis using patient-derived endothelial colony-forming cells (ECFCs). PATIENTS/METHODS: Plasma sample collection and ECFC isolations were performed before valve replacement surgery, 3 to 5 days after, and 6 months after surgery. Plasma VWF antigen, activity, propeptide, collagen binding, multimers, factor VIII coagulant activity, and ADAMTS13 activity (a disintegrin-like and metalloprotease with thrombospondin type 1 motifs 13) were determined. ECFCs were assessed for VWF and angiopoietin-2 (Ang-2) storage and secretion, cell proliferation, and tubule formation in Matrigel. RESULTS AND CONCLUSIONS: Aortic stenosis patients exhibited quantitative and qualitative abnormalities of VWF including significantly increased VWF antigen, activity, and propeptide levels following surgery (P < .01). Increased high molecular weight VWF multimers were observed at all time points and in particular 3 to 5 days after surgery (mean = 14% ± 6%) relative to before (mean = 10% ± 4%), suggesting increased proteolysis by ADAMTS13 pre-operatively in a shear-dependent manner. ECFCs from patients with aortic stenosis were more proliferative than controls (P < .05) and had increased retention of Ang-2 (P < .05) suggesting epigenetic modification of the cells. Overall, there are hemostatic changes in AS patients that are present before valve replacement surgery and these persist long after surgery has occurred. These findings have implications for the current clinical management of AS patients.


Assuntos
Angiodisplasia , Estenose da Valva Aórtica , Doenças de von Willebrand , Estenose da Valva Aórtica/cirurgia , Proliferação de Células , Humanos , Fator de von Willebrand
14.
Res Pract Thromb Haemost ; 4(1): 92-99, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31989089

RESUMO

BACKGROUND: Bleeding assessment is part of the diagnostic workup of von Willebrand disease (VWD). Bleeding assessment tools (BATs) have standardized obtaining this information but have been criticized because they are time consuming. OBJECTIVE: To use our legacy data to determine which questions from BATs are the strongest predictors of a VWD diagnosis. PATIENTS/METHODS: Bleeding score data from 3 different BATs were used. Patients aged <12 years were excluded. Questions on BATs relate to different bleeding symptoms, and each symptom is scored by severity. Scores for each symptom were sorted based on whether they indicated clinically significant bleeding, and nonsignificant scores were set as the reference category. Multivariable logistic regression was used to determine the symptoms that were the strongest predictors of a laboratory-confirmed VWD diagnosis. RESULTS: A total of 927 participants were included; 144 (16%) were patients with VWD, and 783 (84%) were healthy controls. The top 3 symptoms for which a clinically significant positive response increased the likelihood of VWD were hemarthrosis (odds ratio [OR], 19.2; 95% confidence interval [CI], 3.7-100.4), postsurgical bleeding (OR, 15.2; 95% CI, 5.9-38.9), and menorrhagia (OR, 10.3; 95% CI, 4.9-21.9). With each increase in number of bleeding symptom categories with clinically significant scores, subjects had a stepwise increase in odds of a VWD diagnosis. CONCLUSIONS: Our results suggest that most of the bleeding symptoms on BATs are significant predictors of VWD, and there is value in assessing multiple bleeding symptoms when eliciting a bleeding history. Certain bleeding symptoms are more useful predictors than others. Future BAT revisions may consider adding a relative weighting to each symptom.

15.
Blood Adv ; 2(20): 2629-2636, 2018 10 23.
Artigo em Inglês | MEDLINE | ID: mdl-30327371

RESUMO

The cause of hemophilia A carrier bleeding is not well established. Desmopressin (DDAVP), used clinically to treat or prevent bleeding, can also be used as a medical stress surrogate. This study's objective was to compare the response to DDAVP in hemophilia A carriers with that in normal control patients. Bleeding was assessed by the International Society on Thrombosis and Hemostasis Bleeding Assessment Tool (ISTH-BAT). DDAVP (0.3 µg/kg) was administered either IV or subcutaneously (SC), and blood was drawn at baseline and 1, 2, and 4 hours postadministration. Blood was assessed for factor VIII (FVIII) level, von Willebrand factor (VWF) antigen (VWF:Ag), VWF activity (VWF:RCo or VWF:GPIbM), thromboelastography (TEG), and thrombin generation assay (TGA) at all points, and for VWF propeptide (VWFpp):Ag ratio and ABO blood type at baseline. Carriers were older than control patients (median age, 34 and 21 years, respectively; P = .003) and had higher ISTH-BAT bleeding scores (median bleeding score, 8 and 0, respectively; P = .001). Carriers had a significantly reduced FVIII response to DDAVP compared with control patients (P ≤ .0001). When only carriers with normal baseline FVIII levels (n = 10) were included, carriers maintained a reduced FVIII response (P ≤ .0001). Furthermore, participants with abnormal bleeding scores had a significantly lower FVIII response to DDAVP compared with those with normal bleeding scores (P = .036). Hemophilia A carriers have a lower and less sustained FVIII response to DDAVP, suggesting an impaired ability to respond to hemostatic stress, which contributes to bleeding.


Assuntos
Desamino Arginina Vasopressina/metabolismo , Hemofilia A/complicações , Hemostasia/efeitos dos fármacos , Adulto , Feminino , Hemofilia A/patologia , Humanos , Masculino , Pessoa de Meia-Idade
16.
Artigo em Inglês | MEDLINE | ID: mdl-24303262

RESUMO

The rigorous assessment of bleeding symptoms is a key component in establishing a diagnosis in patients suspected of having von Willebrand disease (VWD) and other inherited bleeding disorders. Multiple bleeding questionnaires have been developed and validated to capture bleeding history phenotypes for assessing patients with bleeding disorders. In this study we developed a prediction model based on Naïve Bayes decision tree classifier by analyzing various phenotypic attributes derived from multiple bleeding questionnaires. We evaluated the classification effectiveness derived from the top 25 attributes with highest discriminations on prediction of VWD. We used data from 952 patients and the classifier achieved a precision of 95%, recall of 94%, and a Receiving Operating Curve (ROC) area under the curve of 0.97.

17.
Blood Coagul Fibrinolysis ; 24(7): 719-26, 2013 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-23846000

RESUMO

von Willebrand factor (vWF) antigen levels are elevated in patients with end-stage kidney disease (ESKD). We determined the quantitative and qualitative abnormalities of vWF and factors influencing vWF proteolysis in participants with ESKD compared with age-matched controls and determined the association between abnormalities in vWF and mortality over 4 years of follow-up. vWF : Ag and von Willebrand factor propeptide (vWFpp) levels, vWF functional activity (vWF :RCo), vWF multimer profiles, ADAMTS-13, thrombospondin 1 (TSP-1), and interleukin 6 (IL-6) were evaluated before and after a single hemodialysis treatment in 55 individuals with vascular disease and an age-matched group of controls (n = 21). vWF : Ag and vWF activity were significantly higher in the ESKD patients and levels increased further following the dialysis procedure. The percentage of high molecular weight multimers (%HMWMs) was significantly elevated in the ESKD patients compared with controls. TSP-1 was lower and IL-6 was higher providing possible explanation for the increase in %HMWM in ESKD. The %HMWM dropped significantly in the postdialysis sample. Mortality at 4 years was significantly associated with vWF : Ag. There are higher plasma vWF : Ag levels and a small increase in HMWMs in the ESKD milieu. The acute drop in the %HMWM of vWF postdialysis appears to be due to shear forces encountered during the dialysis procedure. The contribution of these abnormalities to either a pro-thrombotic and/or pro-bleeding phenotype in this population requires further study.


Assuntos
Falência Renal Crônica/sangue , Fator de von Willebrand/metabolismo , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade
18.
Behav Brain Res ; 212(2): 168-73, 2010 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-20385173

RESUMO

Metabotropic glutamate receptors (mGluRs), which are coupled to second messenger pathways via G proteins, modulate glutamatergic and GABAergic neurotransmission. Because of their role in modulating neurotransmission, mGluRs are attractive therapeutic targets for anxiety disorders. Previously we showed that mGluR8(-/-) male mice showed higher measures of anxiety in the open field and elevated plus maze than age-matched wild-type mice. In this study, we assessed the potential effects of acute pharmacological modulation of mGluR8 on measures of avoidable and unavoidable anxiety. In addition to wild-type mice, we also tested apolipoprotein E-deficient (Apoe(-/-)) mice, as these mice show increased levels of anxiety-like behaviors and therefore might show an altered sensitivity to mGluR8 stimulation. mGluR8 stimulation with the specific agonist DCPG, or modulation with AZ12216052, a new, positive allosteric modulator of mGluR8 reduced measures of anxiety in both wild-type mice. The effects of mGluR8 positive allosteric modulators, which only affect neurotransmission in the presence of extracellular glutamate, seem particularly promising for patients with anxiety disorders showing benzodiazepine insensitivity.


Assuntos
Ansiedade/metabolismo , Receptores de Glutamato Metabotrópico/metabolismo , Acetanilidas/farmacologia , Animais , Ansiedade/tratamento farmacológico , Apolipoproteínas E/genética , Apolipoproteínas E/metabolismo , Percepção Auditiva/efeitos dos fármacos , Percepção Auditiva/fisiologia , Benzoatos/farmacologia , Fármacos do Sistema Nervoso Central/farmacologia , Glicina/análogos & derivados , Glicina/farmacologia , Masculino , Aprendizagem em Labirinto/efeitos dos fármacos , Aprendizagem em Labirinto/fisiologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Testes Neuropsicológicos , Receptores de Glutamato Metabotrópico/agonistas , Reflexo de Sobressalto/efeitos dos fármacos , Reflexo de Sobressalto/fisiologia , Tioglicolatos/farmacologia , Fatores de Tempo
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