Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0036341 (schizophrenia)
 60,220 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Single-photon emission computed tomography (SPECT) of the brain has been used to define functional abnormalities in two groups of childhood behavior disorders: (1) a "primary" category in which there is exclusive or predominant presentation with cognitive and/or behavioral dysfunction and (2) encephalopathies, often defined etiologically at the biochemical or molecular level, in which clinical expression includes, but is not confined to, neural dysfunction. Radiopharmaceuticals available for such studies are manifold, but those used to date have been predominantly perfusion agents, eg, Xenon-133 (133Xe) and technetium-99m (99mTc) hexamethylpropylene amine oxime, and studies with [99mTc]bicisate are eagerly awaited. Xenon-133 studies require that the patient be in the field of view of the detector while the tracer is administered. This renders it difficult for a subject to perform cognitive and other exercises while being imaged, because the environment is quite foreign. On the other hand, the 99mTc-labeled perfusion agents permit a scintigraphic "snapshot" of regional cerebral blood flow during a behavioral event without having to have the patient under the imaging instrument. Thus, one can separate the administration of the radiotracer, which can be done under more controlled and physiological conditions, from the actual imaging. In addition, greater spatial resolution is achieved with the technetium-based agents. Currently, multidetector or dedicated annular crystal-type cameras are the preferred brain SPECT devices, and they are essential to applications such as cortical "activation mapping" or tomographic detection of receptor systems. Close attention to technical detail and standardization of the child's behavioral environment during the investigation are critical to a successful study. The relative advantages and disadvantages of qualitative versus semiquantitative analysis of imaging date are reviewed. Among primary behavioral disorders, 133Xe SPECT studies in attention deficit disorder-hyperactivity (ADHD) have suggested a pattern of hypoperfusion of striatal and periventricular structures with sensorimotor cortical hyperperfusion. This pattern is consistent with some neurophysiological models of the disorder. In cerebral palsy, perfusional abnormalities have paralleled clinical deficits and may offer information to help predict outcome. The important field of childhood affective disorders (schizophrenia, juvenile autism, depression, etc) remains largely unstudied with SPECT. Finally, representative examples of the use of SPECT to study perfusion in encephalopathies with behavioral expression (phenylketonuria, MELAS (mitochondrial encephalomyopathy with lactic acidosis and stroke-like episodes) syndrome, Wilson's disease, etc) are given.
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PMID:Brain single-photon emission computed tomography for behavior disorders in children. 837 98

Cell and tissue damage in respiratory chain disorders have been related to increased production of reactive oxygen species (ROS). We measured telomere lengths in such disorders since ROS have also been implicated with telomere shortening. We investigated whole blood cell DNA of 14 patients with MELAS-related mitochondriopathy and two patients with the LHON-associated G11778A mutation of the mitochondrial genome. The phenotypes were variable and included an unusual case of schizophrenia-like psychosis associated with the A3243G mutation. As compared to healthy controls telomere shortening in the patient group was advanced (P < or = 0.006). We compare this finding with the accelerated telomere shortening in Down's syndrome and in chromosomal breakage syndromes. We discuss possible relations between advanced telomere shortening and selective constraints that act on proliferating cells with respiratory chain dysfunction.
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PMID:Advanced telomere shortening in respiratory chain disorders. 917 37

Autopsy reports of patients with mitochondrial encephalopathy with lactic acidosis and strokelike episode (MELAS) are rare. This report documents the clinical and autopsy findings of a 47-year-old woman with MELAS syndrome. The diagnosis was corroborated by documenting a mitochondrial DNA mutation tRNA-Leu (UUR) at position 3243. The patient's clinical history was marked by schizophrenia, peptic ulcer disease, constipation requiring hemicolectomy, migraine headaches, deafness, and a left temporal lobe infarct. At autopsy, a muscle biopsy demonstrated numerous ragged red fibers and a partial cytochrome C oxidase deficiency. By electron microscopy, increased numbers of slightly hypertrophic mitochondria were observed focally within myocytes and vessel walls; paracrystalline mitochondrial inclusions were not seen. The brain at autopsy showed mild cerebral atrophy and diffuse cortical gliosis. Prominent bilateral basal ganglia calcifications and vascular sclerosis were present, and a small remote left temporal lobe infarct was seen.
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PMID:Mitochondrial myopathy, encephalopathy, lactic acidosis, and strokelike episodes (MELAS) syndrome: an autopsy report. 982 26