Biomedical subjects

S E Pitner

Publications and source records attributed to S E Pitner.

11 recordsLinked to original sources

PubMed1982

Systolic time interval characteristics in children with Duchenne's progressive muscular dystrophy.

Systolic time interval (STI) characteristics of 17 boys with Duchenne's muscular dystrophy (DMD) were compared with those of 80 normal boys who served as control subjects. The heart rate decreased linearly with age in normal control subjects (r = -.47, P less than .01). By contrast, heart rate was significantly higher in patients with DMD (P less than .001) and tended to increase further with age. Each STI variable for normal control subjects increased significantly with age (P less than or equal to .01); QII, left ventricular ejection time (LVET), and pre-ejection period (PEP), in addition, decreased with increasing heart rate (P less than or equal to .05). In dystrophic patients QII and LVET decreased with increasing heart rate (P less than .001) but were not influenced by age. None of the other STI values in dystrophic patients was significantly influenced by either age or heart rate. Mean QII, LVET, and QI were shorter and PEP, isometric contraction time (ICT), and PEP/LVET ratio were longer (P less than .001) for DMD patients than for normal control subjects. In 13/17 patients, QII and LVET were below the 95% confidence interval of the normal mean, whereas PEP, ICT, and PEP/LVET exceeded the upper limits of normal in 8, 9 and 11 patients, respectively. For dystrophic patients, the difference (delta) between the observed values and those predicted from regression equations for normal control subjects was lower for QII, LVET, and QI (P less than .01) but higher for PEP (P less than .04), ICT, and PEP/LVET ratio (P less than .001). delta QII and delta LVET increased with age (P = .001 and .032, respectively). Duchenne's muscular dystrophy is thus documented to be associated with substantial alterations in STI characteristics that suggest a compromise of global left ventricular performance. Some of these abnormalities increase with age, probably reflecting the progressive cardiomyopathy characteristics of this disease.

Adolescent↗

PubMed1980

Dystrophic degeneration of papillary muscle and ventricular myocardium. A basis for mitral valve prolapse in Duchenne's muscular dystrophy.

The hearts of three children who died with Duchenne's progressive muscular dystrophy and features of mitral valve prolapse were examined to find if the valve disorder arose from cardiomyopathy due to the primary disease or from dystrophic changes in th mitral valve itself. Gross, histologic and ultrastructural features of mitral valve annulus, anterior and posterior leaflets, chordae tendineae, right and left ventricles, and anterior and posterior papillary muscles were compared with those of similar tissues from normal children of matched age and sex. Fibrosis and myofibrillar lysis--most extensive in posterior papillary muscle and in the posterobasal segment of the left ventricle--were the main histopathologic findings. Myofibrillar lysis was characterized by a total loss of actin and myosin myofilaments. By contrast, the mitral valve annulus, its leaflets and the origin, distribution pattern, length and thickness of chordae tendineae were entirely normal. These observations establish that mitral valve prolapse syndrome in Duchenne's dystrophy is an expression of cardiomyopathy involving papillary muscle and ventricular myocardium rather than a result of dystrophic changes in the mitral valve leaflets, annulus or chordae tendineae.

Adolescent↗

PubMed1980

Immunosuppressive agents in corticosteroid-refractory childhood dermatomyositis.

Five patients with childhood dermatomyositis, followed for 18 to 96 months, improved when treated with a combination of corticosteroids and methotrexate (one patient) or corticosteroids and cyclophosphamide (four patients) after having become refractory to corticosteroid therapy alone. Complications of vascular involvement in childhood dermatomyositis or from immunosuppressive therapy were observed in most of these patients. Disease components involving skin, muscle, or systemic vessels sometimes varied independently in regard to disease activity or therapeutic responsiveness. In two patients with stable or improving muscle function, cerebrovascular complications occurred. Monitoring of disease activity was best accomplished by clinical evaluation; serum muscle enzymes usually failed to rise prior to or during periods of clinical worsening.

Child↗

PubMed1978

An ultrastructural basis for electrocardiographic alterations associated with Duchenne's progressive muscular dystrophy.

Electrocardiographic abnormalities were identified in 63 (84%) of 75 patients with Duchenne's progressive muscular dystrophy. A tall R wave over V1 with an abnormal R/S ratio was seen in 64% of the patients, a deep and narrow Q wave greater than 4 mm over leads I, V5, and V6 in 44%, sinus tachycardia in 32% and right axis deviation in 16%. Other ECG abnormalities included an abnormal PV1 index in 14% of patients and a short P-R interval in 6%. Ultrastructural characteristics of the heart were determined for two patients with characteristic electrocardiographic abnormalities. Common to both hearts was a total loss of thick as well as thin myofilaments, which gave a "moth-eaten" appearance to the myofiber. This feature, combined with preservation of the transverse tubular system, formed the most characteristic ultrastructural finding and was seen most consistently in the posterobasal area of the left ventricle. Alterations of Z-band material; accumulation of mitochondria, occasionally containing electron-dense bodies and showing loss or discontinuity of cristae; dilatation of sarcoplasmic reticulum with striking ectasia of cisternae; depletion of glycogen particles; a paucity of lipoid or lipochrome granules; and the absence of virus-like particles were other consistent ultrastructural features. Comparison of skeletal and cardiac muscle disclosed identical subcellular changes. These observations support the contention that the distinctive ECG pattern associated with Duchenne's dystrophy results from multifocal degenerative changes involving myocardium, predominantly the posterobasal region of the left ventricle and the posterior papillary muscle.

Adolescent↗

PubMed1975

Effects of central-nervous-system irradiation on neuropsychologic functioning of children with acute lymphocytic leukemia.

Two neuropsychologic studies were performed to determine the long-term effects of "prophylactic" cranial or craniospinal irradiation on the psychologic and neurologic functions of children with acute lymphocytic leukemia. In a prospective study, 34 patients with leukemia who received either craniospinal irradiation or cranial irradiation combined with intrathecal methotrexate were evaluated by standardized neurologic and psychologic examinations before and after irradiation. Their performance was compared with that of 27 controls who received irradiation to parts of the body other than the cranium. In a retrospective study, 11 patients with leukemia receiving prophylactic craniospinal irradiation and 12 controls with the disease not receiving such therapy were followed from the second year after either irradiation or the initial hematologic remission. Eighteen months after irradiation in the prospective study and four years after irradiation in the retrospective study, no noteworthy neurologic or psychologic differences were found between subjects and controls.

Adolescent↗

PubMed1973