1/11. Lectin analyses of glycoprotein hormones in patients with congenital disorders of glycosylation.OBJECTIVE: The congenital disorders of glycosylation (CDGs) are progressive multisystemic disorders characterized by a heterogeneous deficiency of the carbohydrate moieties in various structural and circulating glycoproteins, representing a natural model for glycoprotein hormone studies. Here, we studied the carbohydrate moiety of circulating glycoprotein hormones in four patients with a clinical suspicion of CDGs. methods: The diagnosis of CDG-I was confirmed in two out of the four cases by transferrin isoelectrofocusing (IEF) and/or carbohydrate-deficient transferrin (CDT) test. The carbohydrate moiety of serum endocrine-related glycoproteins was investigated by means of ricin (immunopurified thyrotropin (TSH)) and concanavalin a (Con-A) (TSH, follicle-stimulating hormone, alpha-subunit and thyroglobulin) lectin affinity chromatography measurement. RESULTS: CDT concentrations were very high in the two patients with CDG-I and moderately enhanced in the remaining two. In the two CDG-I patients, ricin analysis of immunopurified TSH showed a severe impairment of lectin binding, both before and after neuroaminidase treatment, indicating a nearly complete lack of terminal sialic acid and galactose residues. In these two cases, Con-A analysis showed a significant prevalence of firmly bound isoforms with poorly processed carbohydrate chains. In the remaining two cases with unknown CDG classification, TSH binding pattern to ricin was modestly affected and Con-A analysis showed the prevalence of weakly bound glycoprotein isoforms. CONCLUSIONS: The results of ricin analyses in all four patients were consistent with the CDT test and/or serum transferrin IEF. The severe alteration of TSH binding pattern to ricin seems to be characteristic of CDG-I. Nevertheless, TSH biological properties are not severely altered, as normal thyroid function was found in both cases.- - - - - - - - - - ranking = 1keywords = chromatography (Clic here for more details about this article) |
2/11. In vivo and in vitro NMR spectroscopy reveal a putative novel inborn error involving polyol metabolism.In vivo NMR spectroscopy was performed on the brain of a patient with a leukoencephalopathy, revealing unknown resonances between 3.5 and 4.0 ppm. In addition, urine and CSF of the patient were measured using high-resolution NMR spectroscopy. Also in these in vitro spectra, unknown resonances were observed in the 3.5-4.0 ppm region. Homonuclear (1)H two-dimensional J-resolved spectroscopy (JRES) and (1)H-(1)H correlation spectroscopy (COSY) were performed on the patient's urine for more accurate assignment of resonances. The NMR spectroscopic studies showed that the unknown resonances could be assigned to arabinitol and ribitol. This was confirmed using gas chromatography. The arabinitol was identified as D-arabinitol. The patient is likely to suffer from an as yet unknown inborn error of metabolism affecting D-arabinitol and ribitol metabolism. The primary molecular defect has not been found yet. urine spectra of patients suffering from diabetes mellitus or galactosemia were recorded for comparison. Resonances outside the 3.2-4.0 ppm region, which are the most easy to recognize in body fluid spectra, allow easy recognition of various sugars and polyols. The paper shows that NMR spectroscopy in body fluids may help identifying unknown resonances observed in in vivo NMR spectra.- - - - - - - - - - ranking = 1keywords = chromatography (Clic here for more details about this article) |
3/11. D( )-glyceric aciduria: etiology and clinical consequences.A family comprising mother, father, and five children is described. Four of the children were found to excrete massive amounts of D( )-glyceric acid in their urine. This was verified by gas chromatography-mass spectrometry and the configuration determined by capillary gas chromatography of O-acetylated menthyl esters. The excretion ranged from 10.8 to 19.9 mmol/24 h. The remaining child and the parents showed no evidence of this unusual metabolite. The virtual absence of clinical manifestations in this family was particularly interesting. Only two of the children showed any clinical abnormality and this was limited to mild microcephaly and speech delay; the other two children found to excrete large amounts of D( )-glycerate were healthy and developmentally normal at 7 y and 9 y of age. There was a marked increase in the excretion rate of D( )-glycerate in response to both oral fructose and serine loading. These results are consistent with a deficiency of D( )-glycerate kinase and indicate the potentially benign nature of this disorder.- - - - - - - - - - ranking = 2keywords = chromatography (Clic here for more details about this article) |
4/11. D-glyceric acidemia: an inborn error associated with fructose metabolism.A mentally retarded girl with epileptic seizures is described. Urinary organic acid screening revealed a massive excretion of glyceric acid, a normally barely detectable metabolite. Hyperglycinemia was not observed. Capillary gas chromatography of the O-acetylated (-)-menthyl ester of urinary glyceric acid showed the substance to have the D-configuration. The urinary D-glycerate excretion remained unaltered after an oral load with 200 mg/kg L-serine, but oral loading with fructose (1 g/kg) or dihydroxyacetone (1 g/kg) caused a sharp increase of the D-glycerate excretion. Treatment with a diet moderately restricted in fructose led to some clinical improvement as judged by subjective criteria. The metabolic lesion is thought to be located at some step of the fructose catabolic pathway, possibly at the level of hepatic triokinase deficiency.- - - - - - - - - - ranking = 1keywords = chromatography (Clic here for more details about this article) |
5/11. Mannosidosis. Clinical and biochemical study.The clinical, radiological, and biochemical features of 2 male children with mannosidosis are described. Superficially they appeared to suffer from Hurler's syndrome, but the facies, eye signs, radiological and cytological features were atypical. Excess urinary oligosaccharides were found by thin-layer chromatography. The diagnosis was confirmed by determining the acidic alpha-mannosidase activity of leucocytes and cultured skin fibroblasts. Prenatal diagnosis is possible from cultured amniotic cells.- - - - - - - - - - ranking = 1keywords = chromatography (Clic here for more details about this article) |
6/11. Urinary abnormalities in fucosidosis. Characterization of a disaccharide and two glycoasparagines.The urinary excretion of fucose-containing material was found to be highly increased in a patient with fucosidosis type 2. Three structurally related compounds, a disaccharide and two glycoasparagines, were isolated from the urine. The isolation procedure included ultrafiltration, gel chromatography on Sephadex G-25, preparative zone electrophoresis and paper chromatography. From structural studies including optical rotation, sugar analysis, methylation analysis, ninhydrin degradation, reduction with lithium aluminium hydride and partial hydrolysis, the following structures were deduced: formula (see text), where Fucp is fucopyranose, Manp is mannopyranose, Galcp is galactopyranose, GlcNAcp is 2-acetamido-2-deoxyglucopyranose and Asn is asparagine. The yields of these compounds were 1.7, 40, and 6 mg/l, respectively. The origin of the disaccharide and the two glycoasparagines is probably the core region of glycoprotein carbohydrate chains.- - - - - - - - - - ranking = 2keywords = chromatography (Clic here for more details about this article) |
7/11. Congenital ascites as a presenting sign of lysosomal storage disease.Neonatal ascites is usually attributed to hematologic, genitourinary, gastrointestinal tract, or congenital heart disease. When these lesions have been excluded, metabolic storage disorders should be considered in the differential diagnosis. We report eight cases of neonatal ascites associated with different types of lysosomal storage disease: infantile sialidosis, Salla disease, GM1 gangliosidosis, and gaucher disease. In each case there was a history of sibling of perinatal death resulting from the disease. In three cases the diagnosis of ascites was made in utero by ultrasound examination. These diseases are characterized by excretion in the fetal urine of abnormal catabolic products or by measurement of decreased activity of specific lysosomal hydrolases in cultured amniocytes. Thin-layer chromatography of the oligosaccharides in amniotic fluid may be indicated when a diagnosis of persistent fetal ascites has been established.- - - - - - - - - - ranking = 1keywords = chromatography (Clic here for more details about this article) |
8/11. alpha-mannosidosis: analysis of urinary oligosaccharides with high performance liquid chromatography and diagnosis of a case with unusually mild presentation.mannose containing oligosaccharides (OS) excreted in the urine of patients with alpha-mannosidosis have been analyzed with high performance liquid chromatography (HPLC). The HPLC method provides a highly sensitive assay for detection of the urinary oligosaccharides and was employed for diagnosis of a fifteen-year-old female with an unusually mild presentation of the disease. Dysostosis multiplex and coarse facies were absent; mental impairment was particularly mild. The elution profile of the urinary OS from this patient and two, more severely affected, patients with mannosidosis were nearly identical, containing nine major OS fractions. The concentrations of the OS were eight fold lower in our patient but, when calculated relative to creatinine, the levels of the urinary OS of all patients were similar.- - - - - - - - - - ranking = 5keywords = chromatography (Clic here for more details about this article) |
9/11. serum and urinary trisaccharides in mannosidosis.A trisaccharide, Man2glcNAc, was the most abundant urinary oligosaccharide (161-558 mumol per liter) in a patient with mannosidosis. By means of a newly developed high-performance liquid chromatography (HPLC) procedure, we were able to measure low levels of serum trisaccharide (0.1--0.4 nmol per milliliter). This is the first report of the measurements of serum oligosaccharides in mannosidosis. Our observations on the disparate relationship between serum and urinary concentrations of this trisaccharide suggest that a facilitated renal clearance of oligosaccharides may be related to the nonprogressive aspect of this disorder.- - - - - - - - - - ranking = 1keywords = chromatography (Clic here for more details about this article) |
10/11. Mannosidosis: isolation and comparison of mannose-containing oligosaccharides from gingiva and urine.Excessive gingival hyperplasia with storage of mannose-rich oligosaccharides appears to be a unique feature present in a 31-year-old mannosidosis patient. Fractionation and analysis of the gingiva established the presence of (Man)2GlcNAc (2.2 mumol/g), (Man)3GlcNAc (3.5 mumol/g), (Man)4GlcNAc (2.8 mumol/g) and higher oligomers (Man)5GlcNAc--(Man)8GlcNAc (0.5 mumol/g); (Man, mannose; GlcNAc, N-acetylglucosamine). Eight characteristic oligosaccharides were isolated from the patient's urine by thin-layer chromatography. The most abundant was (Man)2GlcNAc (161--558 mumol/l); decreasing amounts of higher homologues up to a dekasaccharide, (Man)9GlcNAc (1--4 mumol/l) were also present. In contrast to urine, in which the trisaccharide was predominant, tetrasaccharides and pentasaccharides were more abundant in gingiva.- - - - - - - - - - ranking = 1keywords = chromatography (Clic here for more details about this article) |
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