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

In galactosemia, prevention of mental retardation depends on early recognition of the disorder and institution of dietary restriction of galactose. We describe an automated fluorometric micromethod for galactose in whole blood spotted on filter paper. Galactose is oxidized by galactose oxidase to D-galacto-hexadialdose and H2O2 and measured as the highly fluorescent condensation product of homovanillic acid formed when H2O2 is acted upon by horseradish peroxidase. The procedure is 10-fold more sensitive than colorimetric procedures for galactose and is not hampered by the nonspecific fluorescence from endogenous NADPH that is encountered in methods in which galactose dehydrogenase is used. At a sampling rate of 40/h with a sample-to-wash ratio of 1/2, carryover is negligible, reproducibility is excellent, and 80% of steady state is achieved. Analytical recovery of added galactose was 95%. The method has the requisite sensitivity and accuracy for quantification of galactosemia and galactosuria in milkfed newborn infants and genetic evaluation of families of patients.
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PMID:Automated fluorometric analysis of galactose in blood. 87 Feb 60

Mannosidosis is a new and rare disorder. The following clinical symptoms should evolve its diagnosis: facial dysmorphy with slight mental retardation; bone deformities with abnormal L2 vertebra and craniosynostosis; biological abnormalities with vacuolized lymphocytes and absence of urinary mucopolysaccharides. Definite diagnosis relies upon detection of mannose oligosaccharides in the urine and serum deficiency of alpha-D-mannosidase.
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PMID:[Mannosidosis: a simple diagnosis]. 98 28

Mannosidosis is a partially defined disorder of glycoprotein metabolism; less than 20 cases have been reported in the literature. In this work, a longitudinal study of five new patients is presented in an attempt to delineate the phenotype and clinical course of this unusual storage disease. The data on our patients and those in the literature indicate that people with mannosidosis appear normal at birth and that their typical phenotype develops by two years of age. This is characterized by a distinctive coarse facies and dysostosis multiplex. Although recurrent infections, hearing loss and mental retardation occur, the course in this storage disorder generally is stable and is compatible with adult life. The diagnosis is confirmed by the presence of a deficiency in alpha-D-mannosidase activity in leukocytes or fibroblasts, by the presence of vacuolated lymphocytes in peripheral blood and foam cells in bone marrow, and an increased excretion of mannose-rich oligosaccharides in urine.
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PMID:Clinical manifestations of mannosidosis--a longitudinal study. 100 71

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

We describe the molecular characterization of two mutations responsible for galactosemia, an inherited disorder of galatose metabolism that causes jaundice, cataracts, and mental retardation in humans. The coding region of galactose-1-phosphate uridylyltransferase (GALT; UDPglucose:alpha-D-galactose-1-phosphate uridylyltransferase, EC 2.7.7.12) was amplified by the polymerase chain reaction from total cDNA of a classic galactosemic individual and was characterized by direct sequencing of the products. Two missense mutations were identified: (i) replacement of valine-44 by methionine and (ii) replacement of methionine-142 by lysine. These mutations led to a drastic reduction in GALT activity when individual mutant cDNAs were overexpressed in a mammalian cell system, although full-length protein is synthesized in this assay. The two galactosemia mutations account for 3 of the 15 galactosemia alleles analyzed. These results suggest that galactosemia is caused by a variety of mutations, which might be responsible for the observed clinical heterogeneity of this disorder. We also present the molecular characterization of two GALT polymorphisms: (i) replacement of leucine-62 by methionine and (ii) replacement of asparagine-314 by aspartate. It appears that galactosemia mutations tend to occur in regions that are highly conserved throughout evolution while the polymorphisms change variable residues.
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PMID:Molecular basis of galactosemia: mutations and polymorphisms in the gene encoding human galactose-1-phosphate uridylyltransferase. 201 74

We measured the cerebral metabolic rate for glucose (CMRglc) with positron emission tomography and [18F]2-fluoro-2-deoxy-D-glucose in a 47-year-old man with trisomy 21 Down's syndrome (DS) and autopsy-confirmed Alzheimer's disease. Dementia was evident from a confirmed history of cognitive decline, memory loss, and personality change. CMRglc in the subject was compared with the mean obtained in 13 healthy younger DS subjects, aged 19 to 33 years. Test scores of general intelligence, visuospatial ability, language, and memory function showed poorer performance in the older subject compared with the younger group. Mean hemispheric CMRglc in the older DS subject was 28% less than in the young DS group, and marked hypometabolism was evident in parietal and temporal lobe association cortices. At autopsy, extensive neuropathology was noted, especially in the parietal and temporal cortical regions, more so than reported in DS subjects without documented dementia. This study is the first complete assessment of cerebral metabolism, neuropsychological competence, and neuropathology in a DS subject with a documented course of dementia, and demonstrates the superimposition of Alzheimer type dementia on previous mental retardation.
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PMID:Dementia in Down's syndrome: cerebral glucose utilization, neuropsychological assessment, and neuropathology. 296

A five-year-old girl was referred to prometaphase chromosome analysis because of mental retardation, facial dysmorphic features suggestive of Cornelia de Lange syndrome, cleft palate and additional minor congenital malformations of the cardiac system and fingers and toes. A familial balanced translocation (3;9)(q26.1; p23) was found. The karyotype of the proposita was 46,XX,der(9),t(3;9)(q26.1;p23). Thus the patient was trisomic for 3q26.1-qter and monosomic for 9p23-pter. The unbalanced chromosome constitution was not detected by standard Q-banding analysis shortly after birth. The karyotype was misdiagnosed as 46,XX,9(p+) in the proposita and her mother, and thought to be a normal variant of chromosome 9. The repeated cytogenetic study led to the diagnosis of the translocation and to the possibility of prenatal diagnosis in the translocation carriers. A survey of 22 published cases of dup(3q) showed that nearly 60% were secondary to familial balanced rearrangements with an excess of maternally derived abnormal chromosomes 3. Red blood cell galactose-1-phosphate-uridyltransferase (GALT) activity was normal in the patient, consistent with previous assignment of the gene locus for GALT to 9p13 (Shih et al. 1982).
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PMID:Partial trisomy 3q syndrome inherited from familial t(3;9)(q26.1; p23). 365 93

The authors performed galactose loading tests in children suffering from chronic diseases: recurrent bronchitis vomiting, diarrhoea, milk-intolerance, somatic and mental retardation, cramps. In 32 of the 92 examined cases galactose levels rose until pathological, pseudo- diabetic levels. Stillbirth, cataract, hyperbilirubinaemia, convulsions occurred among family members of 10 patients. Galactose-1-phosphat-uridyl-transferase levels were decreased only in 4 of the 17 patients examined. In the other cases some different pathway of galactose metabolism is suspected. Complete remission of symptoms was achieved with diet devoid of milk sugar (lactose) in 29 patients: one infant died and two others remained mentally retarded. According to the examinations presented minor deviations of galactose metabolism cause clinical symptoms more frequently in early life as it was supposed until now.
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PMID:[Galactose loading test in infants and small children suffering in recurrent bronchitis and other chronic illness (author's transl)]. 611 85

Forty patients with the Prader-Willi syndrome have been examined. The typical features begin in gestational life with poor fetal vigor and difficulties with birth and post-partum feeding. The classical features of hypotonia, small hands and feet, cryptorchidism can be identified at this time. The delayed milestones, mental retardation and obesity become more prominent later. The average height of the patients in this series who were admitted to the Clinical Study Center was 149 cm and their weight was 114 kg. The weight and height curves show that Prader-Willi individuals are consistently shorter and heavier than normal children. Tests of endocrine function showed normal glucose tolerance. Insulin secretion was increased in relation to obesity. The rise in growth hormone (hGH) after injecting insulin to induce hypoglycemia and after the infusion of arginine was comparable to other obese individuals but was low in comparison to normal weight subjects. There was no rise in growth hormone with L-dopa administration, but there was a rise in hGH with the administration of 2-deoxy-D-glucose. The hypoglycemia produced by insulin was greater in the Prader-Willi patient than in obese controls. The rise in TRH (thyrotropin-releasing hormone) following the injection of TSH (thyrotropin stimulating hormone) was greater in the Prader-Willi patients than in the obese controls. Hypogonadism was routine in this series, and the response to LRH (luteinizing releasing hormone) was absent in all tested subjects. Treatment with clomiphene for 30 to 90 days significantly increased the response to LRH in three adult individuals who had not been treated with gonadal steroids previously and who were hypogonadal. Rectal temperature declined in three of the five Prader-Willi patients during exposure to an ambient temperature of 4 degrees C, but none of the three obese controls showed a decline. Food intake averaged 5167 kcal/d when six patients were given trays containing more food than they could eat. Food intake was not reduced when tryptophan was added to the diet. Salivary secretion was reduced in the Prader-Willi patients. A number of pulmonary function tests were significantly reduced in the study patients compared to obese or normal weight controls. The anatomic findings in four autopsied patients with the Prader-Willi syndrome showed no significant differences from those of obese subjects without this syndrome. The chromosomal pattern showed a deletion or translocation at chromosome 15 in 3 of 12 patients in whom this test was performed. These findings in 40 patients with the Prader-Willi syndrome have been compared with the information contained in 159 reports published in the medical literature.
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PMID:The Prader-Willi syndrome: a study of 40 patients and a review of the literature. 633 43

We report a boy aged 12 years 7 months with mental retardation, hydrocephalus, dysmorphic facial features, congenital heart disease, and skeletal and renal anomalies. The karyotype showed a mosaic tetrasomy 9p involving the secondary constriction. This result was confirmed by tetraplex gene dosage effect for galactose-1-P-uridyltransferase (GALT). Comparing the clinical features of our case with those of previously reported patients, tetrasomy 9p appears to be a distinctive and clinically recognisable malformation syndrome.
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PMID:Tetrasomy 9p confirmed by GALT. 664 73


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