Children's Memorial Hospital

About: Children's Memorial Hospital is a based out in . It is known for research contribution in the topics: Population & Transplantation. The organization has 5652 authors who have published 8967 publications receiving 283837 citations.

Isolated ventricular inversion: A consideration of the morphogenesis, definition and diagnosis of nontransposed and transposed great arteries

Abstract: The clinical, electrocardiographic, hemodynamic, angiocardiographic and pathologic findings are presented in an infant with isolated ventricular inversion (ventricular inversion without transposition of the great arteries). The morphogenesis, definition and diagnosis of nontransposed and transposed great arteries are considered, based on the present case, and on a series of 149 necropsy cases of transposition of the great arteries which were compared with heart specimens having normally related great arteries. There are four anatomic types of distal conus: pulmonary, aortic, combined (pulmonary and aortic), and bilaterally deficient. It is concluded that the development of the distal parts of the conus (subpulmonary and subaortic) largely determines the relations (1) between the semilunar and the atrioventricular valves, (2) between the great arteries and the ventricles, (3) between the semilunar valves (superoinferior and anteroposterior), (4) the presence or absence of distal infundibular stenosis, and (5) the relative locations of high ventricular septal defects (subaortic or subpulmonary). Transpositions of the great arteries display abnormal subaortic conal myocardium. This alters the normal contiguity between the aortic and mitral valves, and results in abnormal relations between the great arteries and the ventricles, and between the great arteries themselves. To our knowledge, transposed great arteries never exhibit mitral-aortic fibrous continuity, whereas nontransposed great arteries always do. The anatomic type of conus, which may readily be determined angiocardiographically, is a more reliable diagnostic guide to the presence or absence of transposition than is the relation between the great arteries, because the latter may be rendered atypical by abnormal ventricular locations.

Relative contributions of neural mechanisms versus muscle mechanics in promoting finger extension deficits following stroke

Abstract: The origins of impaired finger and hand function were exam- ined in 10 stroke survivors with chronic spastic hemiparesis, with the intent of assessing whether mechanical restraint or altered neurophysiological control mechanisms are responsible for the well-known impairment of finger extension. Simultaneous extension of all four metacarpophalangeal (MCP) joints of the impaired hand was either externally imposed using a rotary actuator or attempted voluntarily by the subject. Trials were conducted both before and after administration of a local anesthetic, blocking the median and ulnar nerves at the elbow. The anesthetic was administered to reduce the activity of the muscles flexing the MCP joints, in order to distinguish mechanical from neuronal resistance to imposed MCP rotation. We found that the nerve blockade resulted in a reduction in velocity-dependent torque (P 0.01), thereby indicating significant joint impedance due to spasticity. Blockade also produced a posture-dependent reduction in static torque in declaratively relaxed subjects (P 0.04), suggesting some tonic flexor activity for specific hand postures. No change in either extensor isometric (P 0.33) or isokinetic (0.53) torque was apparent, but 3 of the 10 subjects did exhibit substantial (10°) improvement in voluntary MCP extension following the blockade. This improvement seemed largely due to a decrease in inappropriate flexor activity during the movement, rather than an increase in extensor activity. We argue that persistent and inappropriate flexor acti- vation plays a role in limiting voluntary finger extension, and that this acti- vation is potentially a reflection of altered supraspinal control of key spinal pathways. In all cases, this inappropriate activation was compounded by weakness, apparent in both the extensor and flexor muscles. Muscle Nerve 28: 309 -318, 2003

Biliary atresia is associated with CD4+ Th1 cell-mediated portal tract inflammation.

Abstract: A proposed mechanism in the pathogenesis of biliary atresia involves an initial virus-induced, progressive T cell–mediated inflammatory obliteration of bile ducts. The aim of this study was to characterize the inflammatory environment present within the liver of infants with biliary atresia to gain insight into the role of a primary immune-mediated process versus a nonspecific secondary response to biliary obstruction. Frozen liver tissue obtained from patients with biliary atresia, neonatal giant cell hepatitis, total parenteral nutrition (TPN)–related cholestasis, choledochal cysts, and normal control subjects was used for fluorescent immunohistochemistry studies of cellular infiltrates, cytokine mRNA expression, and in situ hybridization for localization of cytokine-producing cells. Immunohistochemistry revealed increases in CD8+ and CD4+ T cells and Kupffer cells (CD68+) in the portal tracts of biliary atresia. Reverse transcription–PCR analysis of biliary atresia tissue showed a Th1-type cytokine profile with expression of IL-2, interferon-γ, tumor necrosis factor-α, and IL-12. This profile was not seen in normal, neonatal hepatitis or choledochal cyst livers but was present in TPN-related cholestasis. In situ hybridization revealed that the Th1 cytokine–producing cells were located in the portal tracts in biliary atresia and in the parenchyma of TPN-related cholestasis. A distinctive portal tract inflammatory environment is present in biliary atresia, involving CD4+ Th1 cell–mediated immunity. The absence of similar inflammation in other pediatric cholestatic conditions suggests that the portal tract inflammation in biliary atresia is not a secondary response to cholestasis but rather indicates a specific immune response involved in the pathogenesis of biliary atresia.