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Query: UMLS:C0025362 (mental retardation)
 15,878 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

This study extends our previous observation on patients with a tetralogy of Fallot, operated on by the late Dr; Alfred Blalock and his associates between 1945 and 1951, from a 15 year follow-up to 20 years and assesses the final status of these patients 20 to 28 years after their first operation. This study is mainly concerned with the 432 patients known to be alive at the beginning of the 15th postoperative year. At the beginning of the 20th year, 376 patients were alive, 24 had died, 32 had been lost to follow-up. Review of the final status of those 432 patients showed that 169 had no further cardiac surgery after their initial operation, 36 had further palliative surgery, and 227 had total correction. Thirty-seven percent of the first group, and 79.3% of those with total correction were doing well. These two groups, however, are not comparable. Approximately 250 patients have married; 161 have one or more children. Thirty-five percent have graduated from college and 68.7% are earning substantial incomes. The high scholastic achievement of many of these patients is strong evidence that low oxygen saturation of arterial blood is not a prime cause of mental retardation. The occupations of the patients indicate that the quality of their lives is extremely good and that a cardiac handicap in childhood does not preclude success in adult life. Approximately 69% of these patients have repaid in taxes the cost to society of their rehabilitation.
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PMID:Long-time observations on the Blalock-Taussig operation VIII. 20 to 28 year follow-up on patients with a tetralogy of Fallot. 5 Apr 71

Down's Syndrome (DS), the most frequent of congenital birth defects, results from the trisomy of the chromosome numbered 21 in all cells of affected patients. This disease is characterized by developmental anomalies, mental retardation and features of rapid aging, particularly in the brain where the occurrence of Alzheimer's disease (AD) is observed in all trisomy 21 patients over the age of 35. Elucidation of the biological mechanisms leading to brain aging in DS might provide new insight into the understanding of brain aging and AD in normal people. Copper-zinc superoxide dismutase (CuZnSOD) is one of the genes encoded by chromosome 21. As a consequence of gene dosage excess, CuZnSOD activity and protein are increased by 50% in all DS tissues. The level of CuZnSOD protein and mRNA is particularly high in hippocampal pyramidal neurons susceptible to degenerative processes in AD and in dopaminergic melanized-neurons vulnerable in Parkinson's disease. Increased CuZnSOD activity in these age-related neurodegenerative disorders might result in H2O2 overproduction and subsequently promote peroxidative damages within cells. Increase of seleno-dependent glutathione peroxidase (Se-GPx) in DS cells supports this concept. In order to test this hypothesis, cell and animal models of CuZnSOD overexpression have been designed. In cells transfected with the human CuZnSOD gene, and increased Se-GPx activity is observed, a situation which mimics DS. In mice transgenic for the human CuZnSOD, the expression pattern of the transgene in the brain is similar to that in humans, and we can observe an increased peroxidation in this tissue. These data, like others in the literature, support the hypothesis that excess CuZnSOD induces an imbalance in the regulation of oxygen-derived free radical production which might result in peroxidative brain damage and possibly contribute to accelerated aging and age-related neuropathology.
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PMID:Cellular clones and transgenic mice overexpressing copper-zinc superoxide dismutase: models for the study of free radical metabolism and aging. 145 Jun 8

An institutionalized adult cerebral palsy (CP) population was studied to evaluate the orthopaedic, functional, and cardiopulmonary status of 14 residents with untreated scoliosis greater than 45 degrees as compared with 42 residents with mild or no curves. Both groups were comparable in age, sex distribution, percentage of quadriplegics, and extent of mental retardation. Patients in the scoliosis group had more orthopaedic deformities involving the pelvis and hips and needed modified wheelchairs more often than did those without curves. There were no differences in incidence of decubiti, highest functional level achieved, functional loss, oxygen saturation, or pulse.
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PMID:Untreated scoliosis in severe cerebral palsy. 157 97

To protect against reactive oxygen species, prokaryotic and eukaryotic cells have developed an antioxidant defence mechanism where O2- is converted to H2O2 by superoxide dismutase (Sod), and in a second step, H2O2 is converted to H2O by catalase (Cat) and/or glutathione peroxidase (Gpx). If Sod levels are increased without a concomitant Gpx increase, then the intermediate H2O2 accumulates. This intermediate could undergo the Fenton's reaction, generating hydroxyl radicals which may lead to lipid peroxidation in cells. In this study, we investigate the expression of Sod1, Gpx1 and susceptibility to lipid peroxidation during the aging process in mouse brains. We demonstrate that the mRNA levels and enzyme activity of Sod1 are higher in brains from adult mice compared to neonatal mice. Furthermore, we show that a linear increase in Sod1 mRNA and enzyme activity occurs with aging (1-100 weeks). On the contrary, we find that the mRNA and enzyme activity for Gpx1 does not increase with aging in mouse brains. In addition, our results demonstrate that the susceptibility of murine brains to lipid peroxidation increases with aging. The data in this study are consistent with the notion that reactive oxygen species may contribute to the aging process in mammalian brains. These results are discussed in relation to the normal aging process in mammals, and to the premature aging and mental retardation in Down syndrome.
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PMID:Cu/Zn superoxide dismutase mRNA and enzyme activity, and susceptibility to lipid peroxidation, increases with aging in murine brains. 159 44

Fetal ischemia or hypoxia can lead to cerebral palsy, mental retardation and epilepsy. We propose that the production of nitric oxide and oxygen radicals by neurons when ischemic or hypoxic brain is reperfused may contribute to cerebral injury. Ischemia will depolarize neuronal membranes causing the synaptic discharge of the excitatory neurotransmitter glutamate, which in turn opens the voltage-dependent, N-methyl-D-aspartic acid-specific glutamate receptor/ionophore, allowing calcium to accumulate in the neuron. Calcium in turn activates an oxygen-dependent neuronal nitric oxide synthetase, which oxidizes arginine to produce nitric oxide (.NO) when oxygen is readmitted to brain by reperfusion. Nitric oxide reacts with the oxygen radical superoxide (O2-), also produced by reperfusion, to form peroxynitrite (ONOO-). Peroxynitrite can diffuse for several micrometers before decomposing to form the powerful and cytotoxic oxidants hydroxyl radical and nitrogen dioxide. The hypothesis is consistent with available evidence on the protective action of glutamate antagonists and of oxygen radical scavengers for limiting cerebral infarction following focal ischemia.
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PMID:The double-edged role of nitric oxide in brain function and superoxide-mediated injury. 167 55

In 1930 adenosine triphosphate appeared in the literature from W. A. Engelhardt's work on avian erythrocytes. This was an early example of oxidative phosphorylation in intact cells, and it required methylene blue and oxygen. Both Belitser and I realized that the use of Warburg manometers for aeration was critical in order to generate oxidative phosphorylation of glucose in tissue preparations. Test tube techniques did not work. In 1956 we were able to describe a human type of diabetes called "galactose diabetes," in which consumption of human or cows' milk provokes mental retardation. Replacement of human or cows' milk products with "vegetable milk" formula in early infancy can prevent retardation. We determined that the disease results from a defect of galactose-one-phosphate uridylyl-transferase, a hereditary enzyme. This type of enzyme defect, if discovered and treated in early infancy, is a benign molecular disease. Regulation of transport systems in mammalian cell cultures are frequently complex energized systems. Perhaps my greatest surprise in this regard was the mere fact that an all-cis "odd" hexose-D-allose turned out to be a highly intense down-regulator of the hexose transport system. Additions of inhibitors of oxidative phosphorylation (such as oligomycin or di-nitrophenol) arrested the allose-mediated down-regulation. We have reason to suspect that the strong down-regulator is a phosphorylated form of D-allose. Thus ends my story about oxidative energized biological phosphorylation systems.
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PMID:50 years of biological research--from oxidative phosphorylation to energy requiring transport regulation. 188 94

Sotos' syndrome (synonym: cerebral gigantism) is the association of mental retardation, macrocephaly and prenatal onset of accelerated growth. The rapid skeletal growth may account for a 4% incidence of scoliosis. General anaesthesia using halothane or enflurane in nitrous oxide and oxygen, with opioid supplementation and labetalol to induce moderate hypotension, appeared to be a satisfactory technique for corrective spinal surgery. The potential problems are discussed, with mental retardation and sometimes aggressive behaviour contraindicating a "wake-up" test. Extradural somatosensory evoked potential monitoring is a satisfactory alternative. Hook failures seem more likely than in patients undergoing surgery for adolescent idiopathic scoliosis.
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PMID:Posterior spinal fusion in Sotos' syndrome. 206 91

Literature data on the harmful effects of smoking during pregnancy are reviewed with special emphasis on the fetal growth retardation and delayed changes in child behavior. Intrauterine growth retardation is one of the major causes of low birth weight. It was shown that the birth weight of neonates in smoking mothers can be decreased by 30-396 g. Mass screening data indicate that smoking during pregnancy also increases perinatal mortality (up to 28%). Intrauterine growth retardation was also observed following passive smoking. Inhalation of tobacco smoke by pregnant women was found to increase the fetal heart rate and inhibit fetal movements. Children born from smoking mothers had the higher incidence of asphyxia, cyanosis and hyperactivity. Mass longitudinal studies of children of smoking mothers indicated learning disability, slight mental retardation and insufficient social adaptation by the age of 7 years. Special neurological follow-up study of 326 children revealed frequent minimal brain dysfunction. Pathogenesis of fetal disorders was shown to be associated with impaired adaptation to pregnancy in smoking women. Majority of the constituents of tobacco smoke are capable to pass through the placental-fetal barrier. The most harmful components for fetal development were found to be nicotine and carbon monoxide, which reduce the placental perfusion and blood flow. Exposure to carbon monoxide was shown to increase the level of carboxyhemoglobin and decrease the level of oxyhemoglobin resulting in reduced oxygen supply to fetal tissues and fetal anoxia.
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PMID:[Pathogenesis of fetal growth retardation and behavioral disorders in the progeny caused by smoking during pregnancy]. 265

We studied a patient with somatic growth failure with easy fatigability, myopathy with mitochondrial abnormality, increased lactate and pyruvate in blood and CSF, mental retardation, seizure, myoclonus, deafness, cerebellar ataxia, and blindness with macular degeneration and optic atrophy. Pathologic findings included multiple brain infarctions and massive calcification in the basal ganglia. Biochemical studies of isolated mitochondria revealed decreased oxygen consumption in skeletal muscle, diaphragm, and brain, suggesting an abnormality in the respiratory chain.
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PMID:Mitochondrial encephalomyopathy with lactate-pyruvate elevation and brain infarctions. 653 55

The aim of this study was to evaluate the dental treatments under nitrous oxide-oxygen sedation carried out during 1 yr by the first 45 Swedish dentists trained at probationary courses in the use of the technique. Special emphasis was placed on evaluating the risk and incidence of side effects. Data from 1719 treatment sessions in 823 patients, mainly children, were analyzed. Standardized sedation technique was used and the maximum level of nitrous oxide administered was set at 60%. About 90% of the patients showed excellent or fair acceptance. Factors influencing the acceptance were the patient's age, history of psychiatric disorders, mental retardation and occurrence of side effects. In 4.5% of the treatment sessions the patient experienced side effects, e.g. restlessness, vomiting or nausea, during treatment and in 0.9% after the treatment session. The side effects were mainly mild. No correlation was found between side effects and the nitrous oxide concentration used, length of treatment, patient's age or health classification. It is concluded that nitrous oxide-oxygen sedation is an excellent and safe aid to dental care.
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PMID:Nitrous oxide-oxygen sedation in dental care. 658 Sep 99


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