153 research outputs found

    A single codon insertion in PICALM is associated with development of familial subvalvular aortic stenosis in Newfoundland dogs

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    Familial subvalvular aortic stenosis (SAS) is one of the most common congenital heart defects in dogs and is an inherited defect of Newfoundlands, golden retrievers and human children. Although SAS is known to be inherited, specific genes involved in Newfoundlands with SAS have not been defined. We hypothesized that SAS in Newfoundlands is inherited in an autosomal dominant pattern and caused by a single genetic variant. We studied 93 prospectively recruited Newfoundland dogs, and 180 control dogs of 30 breeds. By providing cardiac screening evaluations for Newfoundlands we conducted a pedigree evaluation, genome-wide association study and RNA sequence analysis to identify a proposed pattern of inheritance and genetic loci associated with the development of SAS. We identified a three-nucleotide exonic insertion in phosphatidylinositol-binding clathrin assembly protein (PICALM) that is associated with the development of SAS in Newfoundlands. Pedigree evaluation best supported an autosomal dominant pattern of inheritance and provided evidence that equivocally affected individuals may pass on SAS in their progeny. Immunohistochemistry demonstrated the presence of PICALM in the canine myocardium and area of the subvalvular ridge. Additionally, small molecule inhibition of clathrin-mediated endocytosis resulted in developmental abnormalities within the outflow tract (OFT) of Xenopus laevis embryos. The ability to test for presence of this PICALM insertion may impact dog-breeding decisions and facilitate reduction of SAS disease prevalence in Newfoundland dogs. Understanding the role of PICALM in OFT development may aid in future molecular and genetic investigations into other congenital heart defects of various species

    No impact of polymorphism in the phosphodiesterase 5A gene in Cavalier King Charles Spaniels on pimobendan-induced inhibition of platelet aggregation response

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    Background: A variant in the canine phosphodiesterase (PDE) 5A gene (PDE5A: E90K) is associated with decreased concentrations of circulating cyclic guanosine monophosphate (cGMP) and response to PDE5 inhibitor treatment. Pimobendan is a PDE inhibitor recommended for medical treatment of certain stages of myxomatous mitral valve disease (MMVD) in dogs.Hypothesis: PDE5A:E90K polymorphism attenuates the inhibitory effect of pimobendan on in vitro platelet aggregation and increases basal platelet aggregation in Cavalier King Charles Spaniels (CKCS). Selected clinical variables (MMVD severity, sex, age, hematocrit, platelet count in platelet-rich plasma [PRP], and echocardiographic left ventricular fractional shortening [LV FS]) will not show an association with results.Animals: Fifty-two privately owned CKCS with no or preclinical MMVD.Methods: Using blood samples, we prospectively assessed PDE5A genotype using Sanger sequencing and adenosine diphosphate-induced platelet aggregation response (area under the curve [AUC], maximal aggregation [MaxA], and velocity [Vel]) with and without pimobendan using light transmission aggregometry. Dogs also underwent echocardiography.Results: Pimobendan inhibited platelet function as measured by AUC, MaxA, and Vel at a concentration of 10 mu M (P <.0001) and Vel at 0.03 mu M (P <.001). PDE5A:E90K polymorphism did not influence the inhibitory effect of pimobendan or basal platelet aggregation response.Conclusions and Clinical Importance: The PDE5A:E90K polymorphism did not influence in vitro basal platelet aggregation response or the inhibitory effect of pimobendan on platelet aggregation in CKCS. Dogs with the PDE5A:E90K polymorphism did not appear to have altered platelet function or response to pimobendan treatment

    Angiotensin-converting enzyme activity and inhibition in dogs with cardiac disease and an angiotensin-converting enzyme polymorphism

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    OBJECTIVE The objective of this study was to evaluate angiotensin-converting enzyme (ACE) activity in dogs and with and without an ACE polymorphism in the canine ACE gene, before and after treatment with an ACE inhibitor. METHODS Thirty-one dogs (20 wild-type, 11 ACE polymorphism) with heart disease were evaluated with ACE activity measurement and systolic blood pressure before and after administration of an ACE inhibitor (enalapril). RESULTS Median pre-treatment ACE activity was significantly lower for ACE polymorphism dogs than for dogs with the wild-type sequence ( P=0.007). After two weeks of an ACE inhibitor, ACE activity was significantly reduced for both genotypes (wild-type, P&lt;0.0001; ACE polymorphism P=0.03); mean post-therapy ACE activity was no different between the groups. CONCLUSION An ACE polymorphism is associated with lower levels of ACE activity. Dogs with the polymorphism still experience suppression of ACE activity in response to an ACE inhibitor. It is possible that the genetic status and ACE activity of dogs may impact the response of dogs with this variant to an ACE inhibitor

    Medical Students Educate Teens About Skin Cancer: What Have We Learned?

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    Skin cancer is a serious societal problem, and public awareness outreach, including to youth, is crucial. Medical students have joined forces to educate adolescents about skin cancer with significant impacts; even one 50-min interactive outreach session led to sustained changes in knowledge and behavior in a cohort of 1,200 adolescents surveyed. Medical students can act as a tremendous asset to health awareness public outreach efforts: enthusiastic volunteerism keeps education cost-effective, results in exponential spread of information, reinforces knowledge and communication skills of future physicians, and can result in tangible, life-saving benefits such as early detection of melanoma

    Improved outcomes of pediatric dilated cardiomyopathy with utilization of heart transplantation

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    AbstractObjectivesWe studied the outcomes of pediatric patients diagnosed with dilated cardiomyopathy (DCM) and their relation to epidemiologic and echocardiographic variables at the time of presentation.BackgroundThe outcome of pediatric DCM patients ranges from recovery to a 50% to 60% chance of death within five years of diagnosis. The impact of heart transplantation and other emerging therapies on the outcomes of pediatric DCM patients is uncertain.MethodsWe performed a retrospective study of the outcomes in 91 pediatric patients diagnosed with DCM from 1990 to 1999. Routine therapy included use of digoxin, diuretics, angiotensin-converting enzyme inhibitors, and heart transplantation.ResultsAt the time of last follow-up, 11 patients (12%) had died without transplantation; 20 (22%) underwent transplantation; 27 (30%) had persistent cardiomyopathy; and 33 (36%) had recovery of left ventricular systolic function. Overall actuarial one-year survival was 90%, and five-year survival was 83%. However, actuarial freedom from “heart death” (death or transplantation) was only 70% at one year and 58% at five years. Multivariate analysis found age <1 year (hazard ratio 7.1), age >12 years (hazard ratio 4.5), and female gender (hazard ratio 3.0) to be significantly associated with a greater risk of death or transplantation and a higher left ventricular shortening fraction at presentation (hazard ratio 0.92), with a slightly decreased risk of death or transplantation.ConclusionsPediatric DCM patients continue to have multiple outcomes, with recovery of left ventricular systolic function occurring most frequently. Utilization of heart transplantation has led to improved survival after the diagnosis of pediatric DCM

    Macrophage-Specific Chemokines Induced via Innate Immunity by Amino Acid Copolymers and Their Role in EAE

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    The random amino acid copolymer poly(Y,E,A,K)n (Copaxone®) is widely used in multiple sclerosis treatment and a second generation copolymer poly(Y,F,A,K)n with enhanced efficacy in experimental autoimmune encephalomyelitis in mice has been described. A major mechanism through which copolymers function to ameliorate disease is the generation of immunosuppressive IL-10-secreting regulatory T cells entering the CNS. In addition, the antigen presenting cell to which these copolymers bind through MHC Class II proteins may have an important role. Here, both CCL22 (a Th2 cell chemoattractant) in large amounts and CXCL13 in much smaller amounts are shown to be secreted after administration of YFAK to mice and to a smaller extent by YEAK parallel to their serum concentrations. Moreover, bone marrow-derived macrophages secrete CCL22 in vitro in response to YFAK and to higher concentrations of YEAK. Strikingly, these chemokines are also secreted into serum of MHC Class II −/− mice, indicating that an innate immune receptor on these cells also has an important role. Thus, both the innate and the adaptive immune systems are involved in the mechanism of EAE amelioration by YFAK. The enhanced ability of YFAK to stimulate the innate immune system may account for its enhanced efficacy in EAE treatment
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