Constitutively active AMP kinase mutations cause glycogen storage disease mimicking hypertrophic cardiomyopathy.

Mutations in PRKAG2, the gene for the gamma 2 regulatory subunit of AMP-activated protein kinase, cause cardiac hypertrophy and electrophysiologic abnormalities, particularly preexcitation (Wolff-Parkinson-White syndrome) and atrioventricular conduction block. To understand the mechanisms by which PRKAG2 defects cause disease, we defined novel mutations, characterized the associated cardiac histopathology, and studied the consequences of introducing these mutations into the yeast homologue of PRKAG2, Snf4. Although the cardiac pathology caused by PRKAG2 mutations Arg302Gln, Thr400Asn, and Asn488Ile include myocyte enlargement and minimal interstitial fibrosis, these mutations were not associated with myocyte and myofibrillar disarray, the pathognomonic features of hypertrophic cardiomyopathy caused by sarcomere protein mutations.

Accelerated cardiomyopathy in mice with overexpression of cardiac G(s)alpha and a missense mutation in the alpha-myosin heavy chain.

Background: To understand further the pathogenesis of familial hypertrophic cardiomyopathy, we determined how the cardiomyopathy induced by an Arg403-->Gln missense mutation in the alpha-myosin heavy chain (403) is affected by chronically enhancing sympathetic drive by mating the mice with those overexpressing G(s)alpha (G(s)alpha x403).

Methods And Results: Heart rate in 3-month-old conscious mice was elevated similarly (P<0.05) in mice overexpressing G(s)alpha (G(s)alpha mice; 746 +/- 14 bpm) and G(s)alpha x403 mice (718+/- 19 bpm) compared with littermate wild-type mice (WT; 623+/- 18 bpm) and 403 mice (594+/- 16 bpm).

Sarcomere protein gene mutations in hypertrophic cardiomyopathy of the elderly.

Background: Hypertrophic cardiomyopathy, a familial myocardial condition caused by sarcomere protein mutations, is usually recognized by early adulthood. Hypertrophic cardiomyopathy of the elderly has similar clinical features but, notably, a later age of onset and noncontributory family history. Causes of elderly-onset hypertrophic cardiomyopathy are unknown.

Mutations of TTN, encoding the giant muscle filament titin, cause familial dilated cardiomyopathy.

Congestive heart failure (CHF) can result from various disease states with inadequate cardiac output. CHF due to dilated cardiomyopathy (DCM) is a familial disease in 20-30% of cases and is associated with mutations in genes encoding cytoskeletal, contractile or inner-nuclear membrane proteins. We show that mutations in the gene encoding giant-muscle filament titin (TTN) cause autosomal dominant DCM linked to chromosome 2q31 (CMD1G; MIM 604145).

Ventricular arrhythmia vulnerability in cardiomyopathic mice with homozygous mutant Myosin-binding protein C gene.

Background: Homozygous mutant mice expressing a truncated form of myosin-binding protein C (MyBP-C(t/t)) develop severe dilated cardiomyopathy, whereas the heterozygous mutation (MyBP-C(t/+)) causes mild hypertrophic cardiomyopathy. Adult male MyBP-C(t/t) and MyBP-C(t/+) mice were evaluated for arrhythmia vulnerability with an in vivo electrophysiology study.

Methods And Results: Surface ECGs were obtained for heart rate, rhythm, and conduction intervals.

A polymorphic modifier gene alters the hypertrophic response in a murine model of familial hypertrophic cardiomyopathy.

Familial hypertrophic cardiomyopathy (FHC), an autosomal dominant disorder caused by mutationally altered dominant-acting sarcomere proteins, exhibits significant clinical heterogeneity. To determine whether genetic background could influence the expression of this disease, we studied a murine model for this human condition. Hypertrophic responses to the Arg403Gln missense mutation in a cardiac myosin heavy chain gene were compared in 129SvEv (inbred; designated 129SvEv- alpha MHC403/+) and Black Swiss (outbred; designated BSw- alpha MHC403/+) strains.

Malakoplakia involving the abdominal wall, urinary bladder, vagina, and vulva: case report and discussion of malakoplakia-associated bacteria.

A 29-year-old woman presented with a 3-month history of multiple purulent discharging nodules involving her lower abdomen, vulva, and left thigh. Physical examination also disclosed vaginal nodules and a left pelvic mass. Cystoscopy revealed multiple mucosal nodules and a perforation of the left vesical wall that appeared to communicate with the pelvic mass.

Uterine adenosarcoma with sarcomatous overgrowth versus uterine carcinosarcoma: comparison of treatment and survival.

Objective: Uterine adenosarcoma with sarcomatous overgrowth (ASSO) is a rare variant of uterine sarcoma first described in 1989. This clinicopathologic study was undertaken to compare the treatment and survival of uterine adenosarcoma with sarcomatous overgrowth to that of uterine carcinosarcomas.

Methods: A review of uterine sarcomas diagnosed at Washington Hospital Center from January 1988 to December 1998 was performed.

A murine model of Holt-Oram syndrome defines roles of the T-box transcription factor Tbx5 in cardiogenesis and disease.

Heterozygous Tbx5(del/+) mice were generated to study the mechanisms by which TBX5 haploinsufficiency causes cardiac and forelimb abnormalities seen in Holt-Oram syndrome. Tbx5 deficiency in homozygous mice (Tbx5(del/del)) decreased expression of multiple genes and caused severe hypoplasia of posterior domains in the developing heart. Surprisingly, Tbx5 haploinsufficiency also markedly decreased atrial natriuretic factor (ANF) and connexin 40 (cx40) transcription, implicating these as Tbx5 target genes and providing a mechanism by which 50% reduction of T-box transcription factors cause disease.

Development of left ventricular hypertrophy in adults in hypertrophic cardiomyopathy caused by cardiac myosin-binding protein C gene mutations.

Objectives: We sought to determine whether the development of left ventricular hypertrophy (LVH) can be demonstrated during adulthood in genetically affected relatives with hypertrophic cardiomyopathy (HCM).

Background: Hypertrophic cardiomyopathy is a heterogeneous cardiac disease caused by mutations in nine genes that encode proteins of the sarcomere. Mutations in cardiac myosin-binding protein C (MyBPC) gene have been associated with age-related penetrance.

Health plans' use of asthma quality improvement projects to meet NCQA accreditation standards.

Background: Managed care represents an important system of healthcare delivery in the United States and the primary source of care for many persons with asthma.

Objective: To characterize how US managed care health plans address the quality of asthma care through the use of disease-specific quality improvement (QI) programs complying with National Committee for Quality Assurance (NCQA) standards.

Methods: This study was a cross-sectional review of reports from all accreditation surveys conducted in 1996 and 1997 by the NCQA.

Abnormal fragile histidine triad (FHIT) expression in advanced cervical carcinoma: a poor prognostic factor.

The FHIT gene is a candidate tumor suppressor gene that has been implicated in the development of cervical carcinoma. We hypothesized that abnormal Fhit expression might be a poor prognostic factor for patients with cervical cancer. The tumors from 59 high-risk patients (stage II-III) were evaluated for abnormal Fhit expression by immunohistochemical staining.

A nonsense mutation in MSX1 causes Witkop syndrome.

Witkop syndrome, also known as tooth and nail syndrome (TNS), is a rare autosomal dominant disorder. Affected individuals have nail dysplasia and several congenitally missing teeth. To identify the gene responsible for TNS, we used candidate-gene linkage analysis in a three-generation family affected by the disorder.

A serologically identified tumor antigen encoded by a homeobox gene promotes growth of ovarian epithelial cells.

Ovarian carcinomas are thought to arise from cells of the ovarian surface epithelium by mechanisms that are poorly understood. Molecules associated with neoplasia are potentially immunogenic, but few ovarian tumor antigens have been identified. Because ovarian carcinomas can elicit humoral responses in patients, we searched for novel tumor antigens by immunoscreening a cDNA expression library with ovarian cancer patient serum.

Cardiomyopathy in Irx4-deficient mice is preceded by abnormal ventricular gene expression.

To define the role of Irx4, a member of the Iroquois family of homeobox transcription factors in mammalian heart development and function, we disrupted the murine Irx4 gene. Cardiac morphology in Irx4-deficient mice (designated Irx4(Delta ex2/Delta ex2)) was normal during embryogenesis and in early postnatal life. Adult Irx4(Delta ex2/Delta ex2) mice developed a cardiomyopathy characterized by cardiac hypertrophy and impaired contractile function.

Comparison of two murine models of familial hypertrophic cardiomyopathy.

Although sarcomere protein gene mutations cause familial hypertrophic cardiomyopathy (FHC), individuals bearing a mutant cardiac myosin binding protein C (MyBP-C) gene usually have a better prognosis than individuals bearing beta-cardiac myosin heavy chain (MHC) gene mutations. Heterozygous mice bearing a cardiac MHC missense mutation (alphaMHC(403/+) or a cardiac MyBP-C mutation (MyBP-C(t/+)) were constructed as murine FHC models using homologous recombination in embryonic stem cells. We have compared cardiac structure and function of these mouse strains by several methods to further define mechanisms that determine the severity of FHC.

Identification of genetic loci associated with paralysis, inflammation and weight loss in mouse experimental autoimmune encephalomyelitis.

Experimental autoimmune encephalomyelitis (EAE), a model for human multiple sclerosis, is an inducible inflammatory and demyelinating disease of the central nervous system (CNS). Susceptibility to this disease is heritable and is demonstrated by the development of an ascending paralysis accompanied by a loss in body wt 2-3 weeks following immunization with proteins derived from CNS myelin. In a previous genetic analysis of susceptibility to EAE in a cross between susceptible SJL/J mice and resistant B10.

Mutations in sarcomere protein genes as a cause of dilated cardiomyopathy.

Background: The molecular basis of idiopathic dilated cardiomyopathy, a primary myocardial disorder that results in reduced contractile function, is largely unknown. Some cases of familial dilated cardiomyopathy are caused by mutations in cardiac cytoskeletal proteins; this finding implicates defects in contractile-force transmission as one mechanism underlying this disorder. To elucidate this important cause of heart failure, we investigated other genetic causes of dilated cardiomyopathy.

An abnormal Ca(2+) response in mutant sarcomere protein-mediated familial hypertrophic cardiomyopathy.

Dominant-negative sarcomere protein gene mutations cause familial hypertrophic cardiomyopathy (FHC), a disease characterized by left-ventricular hypertrophy, angina, and dyspnea that can result in sudden death. We report here that a murine model of FHC bearing a cardiac myosin heavy-chain gene missense mutation (alphaMHC(403/+)), when treated with calcineurin inhibitors or a K(+)-channel agonist, developed accentuated hypertrophy, worsened histopathology, and was at risk for early death. Despite distinct pharmacologic targets, each agent augmented diastolic Ca(2+) concentrations in wild-type cardiac myocytes; alphaMHC(403/+) myocytes failed to respond.

Homozygous mutation in cardiac troponin T: implications for hypertrophic cardiomyopathy.

Background: Mutations in the gene that encode cardiac troponin T (cTnT) account for approximately 15% of cases of familial hypertrophic cardiomyopathy (HCM). These mutations are associated with a particularly severe form of HCM characterized by a high incidence of sudden death and a poor overall prognosis, despite subclinical or mild left ventricular hypertrophy.

Methods And Results: We evaluated a family with HCM and multiple occurrences of sudden death in children.

Impact of sociodemographic case mix on the HEDIS measures of health plan quality.

Background: The widely used Health Plan Employer Data and Information Set (HEDIS) measures may be affected by differences among plans in sociodemographic characteristics of members.

Objective: The objective of this study was to estimate effects of geographically linked patient sociodemographic characteristics on differential performance within and among plans on HEDIS measures.

Research Design: Using logistic regression, we modeled associations between age, sex, and residential area characteristics of health plan members and results on HEDIS measures.

Loss of function and inhibitory effects of human CSX/NKX2.5 homeoprotein mutations associated with congenital heart disease.

CSX/NKX2.5 is an evolutionarily conserved homeodomain-containing (HD-containing) transcription factor that is essential for early cardiac development. Recently, ten different heterozygous CSX/NKX2.