Novel mutations in mitochondrial cytochrome b in fatal post partum cardiomyopathy.
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Adult↗
Biomedical subjects
J Marin-Garcia
Publications and source records attributed to J Marin-Garcia.
Localized mitochondrial dysfunction in canine myocardial ischemia.
Effects of myocardial ischemia on mitochondrial enzymes and mitochondrial DNA (mtDNA) were examined using the model of Ameroid constriction of canine cardiac vessels. Endocardium supplied by constricted coronary arteries was found to have significantly lower citrate synthase and complex IV activities compared to values obtained from either epicardium supplied by constricted vessels or endocardium supplied by unconstricted coronary arteries. Neither significant differences in mtDNA copy number nor changes in respiratory complexes I, III and V were detected. These results suggest that highly localized, specific mitochondrial enzyme changes result from chronic myocardial ischemia.
Animals↗
Mitochondrial gene expression during bovine cardiac growth and development.
The expression of both mitochondrial and nuclear genes encoding enzymes involved in electron transport and oxidative phosphorylation was examined in bovine cardiac tissue during early growth, development and aging. The steady state level of mRNAs for mitochondrial genes including ATPase 6. COXII and cyt b increased 2.5-4-fold relative to early fetal levels in late fetal and young adult tissues and showed a marked decline (30-50%) in older adult tissues. Similar results were found with the nuclear genes, COXVB and ATP-beta synthase showing coordinate regulation of the two genomes. An increase in mtDNA copy number correlated with the increase in transcript level. Enzyme activity levels for NADH dehydrogenase and cytochrome c oxidase showed a similar trend, albeit of lesser magnitude. These activity levels contrasted with the activity level of an entirely nuclear-encoded mitochondrial enzyme, citrate synthase, which increased not only throughout development but in the older adult tissue. This study indicates that there is a pattern of increasing mitochondrial and nuclear gene expression for OXPHOS enzymes in developing cardiac tissue and decreasing OXPHOS gene expression in the aging heart.
Animals↗
Mitochondrial dysfunction in a case of fatal infantile cardiomyopathy.
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Cardiomyopathy, Hypertrophic↗
Cardiomyopathy and abnormal mitochondrial function.
The diagnosis of cardiomyopathy is mainly based on clinical and morphological criteria. While metabolic, viral, chemical, genetic, and immunological factors are often proposed as causes of cardiomyopathy, little is known about the role of the respiratory chain and other biochemical mitochondrial defects in this group of diseases. Research on the biochemistry and molecular biology of cardiomyopathies offers an opportunity for a better understanding of the pathogenesis and for finding specific therapy.
Adult↗
Presence of a mitochondrial DNA deletion in fetal and adult bovine cardiac tissue.
A deletion of about 5.3 kilobases has been detected in the mitochondrial DNA of bovine cardiac tissue. This deletion appears to be somatic in origin given its sporadic presence in the various heart compartments examined. Cardiac tissue derived from developmental stages including fetal, early and older adult animals harbored this mutation with increased levels (100-1000 fold) found in older adults. The deleted region of the mitochondrial genome maps to relatively the same area (deleting ATPase6, COXIII, ND2, ND4 and a portion of ND5) as the common 5 kb deletion reported in humans, but its presence in fetal tissue, as well as its decreased age dependence distinguish it relative to the reported human deletion.
Aging↗
Catheter embolization of pulmonary arteriovenous fistulas in an infant.
An infant with pulmonary arteriovenous fistulas is described. Surgical ligation of the fistulas and limited resection of parenchyma from the right lung was followed at 11 months of age, by successful steel coil embolization of residual fistulas.
Arteriovenous Fistula↗
Human cytochrome c oxidase during cardiac growth and development.
Human heart mitochondrial cytochrome c oxidase specific content and specific activity was measured in five fetuses 15-21 weeks gestational age and in five patients whose age ranged from 6 days to 22 years. None had evidence of cardiac pathology. An increase in cytochrome c oxidase specific content and specific activity was observed in the fetal heart with increasing gestational age (0.13-0.38 nmol heme a/mg protein and 67-295 nmol O2 utilized/min/mg protein) and from the neonatal period (0.35 nmol heme a/mg protein and 140 nmol O2/min/mg protein) to adulthood (1.2 nmol heme a/mg protein and 1104 nmol O2/min/mg protein). A marked increase was observed postnatally between 4 and 19 months.
Adolescent↗
Dilated cardiomyopathy in children with acquired immunodeficiency syndrome: a pathologic study of five cases.
Clinicopathologic features with special reference to the heart are presented in five fatal cases of acquired immunodeficiency syndrome (AIDS) in children. Three children showed clinical evidence of cardiovascular compromise or congestive heart failure. Autopsy was performed in all cases. The enlarged heart showed biventricular dilatation with grossly unremarkable valves and coronary arteries and absence of mural thrombi. Microscopic examination of the heart revealed primarily myopathic abnormalities with hypertrophy of the myocardium and only rare foci of sparse inflammatory infiltrate. The pathogenesis of dilated cardiomyopathy in these children with AIDS is not known. Infection, immunologic factors, anemia, deficiency of nutritional factor(s), and longer survival may be related to the pathogenesis. Pediatricians should be alert to the possibility of cardiac involvement in pediatric AIDS.
Acquired Immunodeficiency Syndrome↗
Arteriopathy in children with acquired immune deficiency syndrome.
Pathologic features of the arteries of different organs (heart, lungs, kidneys, spleen, intestine, brain) seen at autopsy in 6 children with acquired immune deficiency syndrome (AIDS) are described. Small and medium-sized arteries, which were the most commonly involved, showed intimal fibrosis with fragmentation of elastic tissue, fibrosis and calcification of media with variable luminal narrowing, and a vasculitis or perivasculitis that was seen only in the brain in association with AIDS encephalopathy. In 1 case aneurysms of the right coronary artery with thrombosis and myocardial infarction were seen. Vascular inflammation, seen only in the brain, may be related to the agent associated with AIDS encephalopathy. The fibrocalcific arterial lesions most closely resemble idiopathic arterial calcification of infancy, but because of differences in age incidence, clinicopathologic and immunologic features, and the size and distribution of the involved arteries, the arterial lesions of pediatric AIDS appear to constitute a distinctive arteriopathy. Infection, secondary to immunodeficiency and resulting in increased exposure to endogenous and exogenous elastases, may be the pathogenesis. Luminal narrowing caused by arterial lesions may play a contributory role in the pathogenesis of the atrophy, cell depletion, scarring, and necrosis or infarction found in organs of children with AIDS. Pediatricians should be alerted to the possibility of arterial involvement in pediatrics AIDS.
Acquired Immunodeficiency Syndrome↗
Quinidine dosage in children using population estimates.
A total of 36 plasma quinidine concentrations from nine hospitalized pediatric patients with cardiac arrhythmias were examined retrospectively to determine factors significantly affecting quinidine dosing. Each plasma quinidine concentration was obtained after at least 24 h of inpatient therapy. Doses of quinidine base varied from 7.7 to 45.6 mg/kg/day and from 179 to 921 mg/m2/day. Six of the eight children who responded to quinidine achieved normal sinus rhythm with plasma concentrations less than 2.0 micrograms/ml. Stepwise multilinear regression analysis demonstrated that the plasma concentration was significantly affected by the quinidine dose and by the time after the dose that the plasma was obtained, but not by the age of the patient. Patient population estimates were then derived to predict the quinidine dosage necessary to achieve given plasma concentrations. The group of patients receiving digoxin concurrently were predicted to obtain higher plasma quinidine levels on smaller doses and a shorter quinidine elimination half-life compared with those patients not on digoxin. While currently recommended quinidine doses by body weight are frequently insufficient, recommended quinidine doses by body surface area are excessive. Children require larger quinidine doses on a body weight basis and respond to a wide range of plasma quinidine concentration. Patient population estimates provide useful information on dosing of infrequently prescribed drugs in children.
Adolescent↗
Effects of tachycardia with normal and ectopic ventricular activation on S-T segment potential and patterns in the dog.
Tachycardia induced by atrial pacing in the dog increases the intensity of potentials recorded on the body surface during the ST-T interval. The effects of tachycardia caused by ectopic right or left ventricular stimulation on ventricular recovery potentials were studied in 30 dogs. Rate was increased in a stopwise manner from 90 to 250 beats per minute by atrial pacing (ten dogs), or by left atrial-right ventricular sequential pacing (ten dogs), or by left atrial-left ventricular sequential pacing (ten dogs). ECG effects were determined by construction of body surface isopotential maps from voltages registered from 84 torso electrodes using a P-R segment baseline. Ectopic stimulation intensified the repolarization maximum and shifted its location to correspond with sites of epicardial stimulation. These findings reflect a reduced cancellation of transventricular differences in recovery times, with earliest recovery occurring at earliest activated sites. Increasing rate with any one activation pattern linearly increased potential extrema magnitudes without further changes of spatial features. This singular response to tachycardia regardless of activation sequence is consistent with an increase in the apparent moment of a repolarization dipole without alteration of its orientation.
Animals↗
Ruptured sinus of valsalva aneurysm in children: report of two cases and literature review.
Two children with ruptured sinus of Valsalva aneurysm are described, each with a ventricular septal defect, and in one there was also an associated discrete subvalvular aortic stenosis. The diagnostic appearance of two-dimensional echocardiography and axial angiocardiography are emphasized to allow early diagnosis and surgical repair. A literature review of recent reports in English disclosed that 13 patients under age 20 had been reported to have ruptured sinus of Valsalva aneurysm.
Adolescent↗
Hypoplastic pulmonary arteries and aorta with obstructive uropathy in 2 siblings.
Two sisters who presented with diffuse hypoplasia of pulmonary arteries, relative hypoplasia of ascending aorta, obstructive uropathy, bilateral ureteral reflux, and hydronephrosis, are described. The subsequent course was characterized by progressive and gradual onset of right heart failure, failure to thrive, chronic malabsorption and systemic hypertension. The syndrome which appears to be transmitted by autosomal recessive inheritance can possibly represent a generalized hypoplasia and growth failure of a part or the entire arterial system. Peripheral pulmonary stenosis can occur as an isolated lesion or in association with other congenital cardiac anomalies, as well as in rubella syndrome and the syndrome of supravalvular aortic stenosis. This communication reports two siblings with a hitherto unreported combination of hypoplastic pulmonary arteries, and aorta with identical genito-urinary tract abnormalities.
Abnormalities, Multiple↗
Fetal supraventricular tachycardia: in utero therapy with digoxin and quinidine.
Digoxin has been successfully used to treat fetal supraventricular tachycardia. When therapy with digoxin fails, alternative therapies have met with equivocal success. In this report, successful fetal therapy with maternally administered digoxin and quinidine is presented in three consecutive patients with fetal supraventricular tachycardia. The arrhythmia was eliminated in each instance. Fetal ascites, present in two fetuses, was completely reversed. Intrapartum fetal distress was not observed. The rationale of this therapy and a review of pertinent literature are also presented.
Administration, Oral↗
Echocardiographic detection of early cardiac involvement in juvenile rheumatoid arthritis.
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Arthritis, Juvenile↗
Myocardial function in Rocky Mountain spotted fever: echocardiographic assessment.
Nine patients with Rocky Mountain spotted fever underwent M-mode echocardiographic examination. Increased left ventricular dimension was found in 2 patients and decreased left ventricular shortening fraction in 7. Diminished mean velocity of circumferential fiber shortening, increased left ventricular systolic time intervals ratio, and increased mitral valve E point to ventricular septal separation were found in 6 patients. One patient died and at necropsy diffuse myocarditis was present. Repeat echocardiographic examination was available in the remaining 8 patients at follow-up (mean 10 months). Abnormal E mitral point to ventricular septal separation remained in 3 patients and decreased left ventricular shortening fraction in 2; in 1 there was also increased left ventricular end-diastolic dimension. Thus abnormal left ventricular function and chamber enlargement are frequently present in patients with Rocky Mountain spotted fever.
Adolescent↗
Left ventricular dysfunction in Rocky Mountain spotted fever.
Rocky Mountain spotted fever is a serious infectious disease that continues to occur with increasing incidence in various areas of the United States. A high case-fatality ratio (11%) persists in spite of availability of adequate chemotherapeutic agents, and the cardiac involvement may play an important role in the final outcome of some cases. To assess the effect of the disease on left ventricular function 13 patients underwent M-mode echocardiographic examination on admission to a children's hospital. Increased left ventricular dimension was found in 3 patients and decreased left ventricular shortening fraction in 9. Diminished mean velocity of circumferential fiber shortening and increased left ventricular systolic time interval ratios were found in 8 patients and increased mitral valve E point to ventricular septal separation in 9. One patient died and biventricular dilatation with diffuse myocarditis was seen at autopsy. Repeat echo examination was available in 11 patients at follow-up (mean 5 months). Abnormal E mitral point to ventricular septal separation remained in 4 patients and decreased left ventricular shortening fraction in 2. The long-term prognosis for this group is unknown. Myocardial involvement is frequently present in Rocky Mountain spotted fever; close monitoring and aggressive therapeutic approach are essential if the high case-fatality ratio is to be reduced.
Adolescent↗