eNOS deficient mice develop progressive cardiac hypertrophy with altered cytokine and calcium handling protein expression.

Although studies have shown that endothelial nitric oxide synthase (eNOS) homozygous knockout mice (eNOS-/-) develop left ventricular (LV) hypertrophy, well compensated at least to 24 wks, uncertainty still exists as to the cardiac functional and molecular mechanistic consequences of eNOS deficiency at later time-points. To bridge the gap in existent data, we examined whole hearts from eNOS-/- and age-matched wild-type (WT) control mice ranging in age from 18 to 52 wks for macroscopic and microscopic histopathology, LV mRNA and protein expression using RNA Dot blots and Western blots, respectively, and LV function using isolated perfused work-performing heart preparations. Heart weight to body weight (HW/BW in mg/g) ratio increased significantly as eNOS-/- mice aged (82.2%, P < 0.001). Multi-focal replacement fibrosis and myocyte degeneration/death were first apparent in eNOS-/- mouse hearts at 40 wks. Progressive increases in LV atrial natriuretic factor (ANF) and alpha-skeletal actin mRNA levels both correlated significantly with increasing HW/BW ratio in aged eNOS-/- mice (r = 0.722 and r = 0.648, respectively; P < 0.001). At 52 wks eNOS-/- mouse hearts exhibited basal LV hypercontractility yet blunted beta adrenergic receptor (betaAR) responsiveness that coincided with a significant reduction in the LV ratio of phospholamban to sarcoplasmic reticulum Ca2+-ATPase-2a protein levels and was preceded by a significant upregulation in LV steady-state mRNA and protein levels of the 28 kDa membrane-bound form of tumor necrosis factor-alpha. We conclude that absence of eNOS in eNOS-/- mice results in a progressive concentric hypertrophic cardiac phenotype that is functionally compensated with decreased betaAR responsiveness, and is associated with a potential cytokine-mediated alteration of calcium handling protein expression.

Gene dosage-dependent effects of cardiac-specific overexpression of the A3 adenosine receptor.

We used a genetic approach to determine whether increasing the level of A3 adenosine receptors (A3ARs) expressed in the heart confers protection against ischemia without causing cardiac pathology. We generated mice carrying one (A3tg.1) or six (A3tg.6) copies of a transgene consisting of the cardiomyocyte-specific alpha-myosin heavy chain gene promoter and the A3AR cDNA. A3tg.1 and A3tg.6 mice expressed 12.7+/-3.15 and 66.3+/-9.4 fmol/mg of the high-affinity G protein-coupled form of the A3AR in the myocardium, respectively. Extensive morphological, histological, and functional analyses demonstrated that there were no apparent abnormalities in A3tg.1 transgenic mice compared with nontransgenic mice. In contrast, A3tg.6 mice exhibited dilated hearts, expression of markers of hypertrophy, bradycardia, hypotension, and systolic dysfunction. When A3tg mice were subjected to 30 minutes of coronary occlusion and 24 hours of reperfusion, infarct size was reduced approximately 30% in A3tg.1 mice and approximately 40% in A3tg.6 mice compared with nontransgenic littermates. The reduction in infarct size in the transgenic mice was not related to differences in risk region size, systemic hemodynamics, or body temperature, indicating that the cardioprotection was a result of increased A3AR signaling in the ischemic myocardium. The results demonstrate that low-level expression of A3ARs in the heart provides effective protection against ischemic injury without detectable adverse effects, whereas higher levels of A3AR expression lead to the development of a dilated cardiomyopathy.

A case of gonadal dysgenesis, breast development, Graves' disease, and low bone mass.

OBJECTIVE: To describe a case of XY gonadal dysgenesis with Tanner stage 4 breast development in the absence of a hormone-producing gonadal neoplasm and with Graves' disease and low bone mass. METHODS: The clinical features, laboratory results, and cytogenetic findings in the patient are presented, and the potential mechanisms of breast development are discussed. A MEDLINE search was performed, and related articles in the English-language literature published between 1955 and 2001 were reviewed. RESULTS: A 23-year-old African American woman was referred to the University of Louisville Hospital for evaluation of hyperthyroidism. About 4 months before this referral, hyperthyroidism was diagnosed, and treatment with methimazole was initiated. She continued to have thyrotoxicosis. Additionally, systemic review disclosed a history of primary amenorrhea. Physical examination revealed a tall phenotypic female patient with Tanner stage 4 breast development. Pelvic examination showed normal findings except for sparse pubic hair. Laboratory evaluation confirmed the diagnosis of Graves' disease as well as primary gonadal failure. Pelvic ultrasonography revealed a small uterus and bilateral adnexal masses (0.9 by 0.6 cm). On chromosomal analysis, a 46,XY karyotype was found. Further analysis of Y-DNA by polymerase chain reaction confirmed the presence of an intact Y chromosome, and no microdeletions were identified. Dual-energy x-ray absorptiometry demonstrated a Z-score of -4.7 and -4.2 at the lumbar spine and right hip, respectively. Graves' disease was successfully treated with (131)I. Laparoscopy was performed to resect streak gonads. On histologic examination, no typical ovarian, testicular, or neoplastic tissue was identified. The breast development in this patient remains unexplained. CONCLUSION: To the best of our knowledge, this is the first case report of a tall XY female patient with breast development in the absence of a hormone-producing gonadal neoplasm and without clearly identifiable gonads. Breast development was most likely related to estrogens, possibly produced by either streak gonads at the time of puberty or peripheral conversion of androgens, or to increased sensitivity of breast tissue to estrogens. Graves' disease is likely coincidental and could contribute to bone loss in such subjects.

Atypical squamous cells as a diagnostic pitfall in pulmonary Wegener's granulomatosis. A case report.

BACKGROUND: Wegener's granulomatosis (WG) is characterized by systemic, necrotizing, granulomatous inflammation accompanied by vasculitis. It classically involves the triad of the upper respiratory tract, lungs and kidneys. Isolated pulmonary lesions of WG may present in some patients as pulmonary masses, simulating neoplasms. The features of WG can be suggested by cytologic study. Atypical epithelial cells associated with WG have previously been reported as a cause of a false positive diagnosis of bronchoalveolar carcinoma. CASE: In this case the cytologic findings included atypical squamous cells in a background of acute, chronic and granulomatous inflammation. In several respiratory specimens the atypical squamous cells were incorrectly interpreted as diagnostic of squamous cell carcinoma. The correct diagnosis of WG was confirmed with open lung biopsy, which demonstrated necrotizing granulomatous inflammation with geographic necrosis and associated vasculitis. CONCLUSION: Markedly atypical squamous cells mimicking squamous cell carcinoma can be found accompanying the inflammatory process associated with WG and are a possible diagnostic pitfall. The possibility of WG as well as other inflammatory processes should always be considered in the differential diagnosis of squamous cell carcinoma of the lung. This case is the only reported case of WG in which atypical squamous cells were a diagnostic pitfall, initially suggesting a diagnosis of squamous cell carcinoma.