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S Sjöblad

Publications and source records attributed to S Sjöblad.

11 recordsLinked to original sources
PubMed1979

Neonatal non-ketotic hyperglycinemia: a clinical, biochemical and neuropathological study including electronmicroscopic findings.

In a family of four children, three died within 8 days after birth. The fourth child survived after a critical first week with the same symptoms as the siblings. He was at the age of four found to have non-ketotic hyperglycinemia. The histories and neuropathology of the other children were then reexamined. It seems highly probable that all siblings suffered from non-ketotic hyperglycinemia. This report points to the clinical, biochemical and neuropathological diagnostic problems in this disease and also adds new information on the ultrastructural changes, not hitherto visualized.

Amino Acid Metabolism, Inborn Errors↗
PubMed1978

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.

Asparagine↗
PubMed1978

beta-D-galactosidase activities in juvenile GM1-gangliosidosis.

beta-Galactosidase activity was investigated in one case of juvenile GM1-gangliosidosis. This patient exhibited normal activity of the neutral form of beta-galactosidase (measured as beta-glucosidase activity) and normal pH curve of residual acid beta-galactosidase activity in leucocytes and fibroblasts. A shift towards more neutral pH optimum was seen in the beta-galactosidase enzyme occurring in serum. The communication also presents a study of the relationship of the different beta-galactosidases in human liver using isolated urine oligosaccharide from this patient as a beta-galactoside substrate. The other natural beta-galactoside substrates used in this investigation were different oligosaccharides, one glycopeptide and ceramide-beta-galactosidase. The beta-galactosidase forms with acidic pH optimum towards synthetic substrate (A forms) exhibit activity towards the natural substrate (except ceramide-beta-galactoside). The "neutral" beta-galactosidase with broad substrate specificity (B form) which includes beta-glucosides had no activity towards the natural substrates used. It could also be shown that the activity towards ceramide-beta-galactoside was a third type of beta-galactosidase different from A and B forms.

Adolescent↗
PubMed1977

A comparison of the alpha-L-fucosidase activities of human liver and serum.

Human liver alpha-L-fucosidase (alpha-L-fucoside fucohydrolase, EC 3.2.1.51) has been separated into four components by chromatography on Sephadex G-150 or DEAE-cellulose. These components differ in their relative stability to heat and acid treatment, and their response to neuraminidase. The serum enzyme was devoid of high molecular weight activity and probably contained more sialic acid residues than the corresponding enzyme from liver. All the liver components tested were able to liberate fucose from 2'-fucosyllactose but not fucose from other oligosaccharides.

Chromatography, DEAE-Cellulose↗
PubMed1977

Lysosomal enzymes in medium from cultured skin fibroblasts from normal individuals and patients with lysosomal diseases.

The release of acid hydrolases from cultured skin fibroblasts into the cell culture medium was studied in several lysosomal storage disorders (GM1-gangliosidosis, Fabry's disease, Hurler's disease, mannosidosis, and mucolipidosis). The levels of different activities were proportional to time (up to 44 h after medium change) and cell density with the exception of beta-glucosidase, which was not released. Culture medium from the fibroblasts of mucolipidosis patients exhibited higher activity of acid hydrolases than medium from cells of patients with GM1-gangliosidosis, Fabry's disease, Hurler's disease, and mannosidosis. These cells, however, exhibited somewhat higher levels of enzyme activity in their culture medium than control fibroblasts. The total production of acid hydrolases was yet rather similar in fibroblasts from controls and patients. Differential centrifugation showed that the highest specific activity of acid hydrolases was seen, as expected, in the lysosomal fraction, except in fibroblasts from patients with mucolipidosis, where the supernatant exhibited most activity. beta-Glucosidase, however, showed a normal differential centrifugation pattern also in fibroblasts from these patients.

Carbohydrate Metabolism, Inborn Errors↗
PubMed1976

Neutral alpha-mannosidase activity in human serum.

Two types of alpha-mannosidase (alpha-D-mannoside mannohydrolase, EC 3.2.1.24) with neutral pH optima exist in serum. The activity with an optimum between pH 6.0 and 6.4 is similar to alpha-mannosidase C, described earlier in tissues. The second activity, with a pH optimum between pH 5.2 and 5.8 is the dominant form in serum. These two forms can be differentiated from each other by gel-filtration, chromatography on DEAE-cellulose or chromatography on Concanavalin-A Sepharose. Using the chromatographic techniques, the serum type neutral activity co-elutes with the acidic forms of the enzyme. However, these two forms can be easily distinguished by effect of pH, heating or inhibition by the substrate methyl-alpha-D-mannopyranoside. The presence of the serum type alpha-mannosidase activity is discussed with respect to mannosidosis, a lysosomal storage disease.

Disaccharidases↗
PubMed1976

Molecular forms and activities of glycosidases in cultures of amniotic-fluid cells.

Ion-exchange chromatography of gel filtration demonstrated the presence of different molecular forms of nine lysosomal enzymes in cultured amniotic-fluid cells. The patterns of molecular forms were similar to those known from skin fibroblasts and liver tissue. During cultivation total enzyme activities fluctuated with the number of passages, without any consistent trend of increase or decrease, and without correlation to the dominating cell type in the culture.

Acetylglucosaminidase↗
PubMed1976

Quantitation of a urinary tetrasaccharide by gas chromatography and mass spectrometry.

A gas chromatographic mass spectrometric method has been developed for the rapid determination of a urinary tetrasaccharide (alpha-D-Glc-(1 leads to 6)-alpha-D-Glc-(1 leads to 4)-alpha-D-Glc-(1 leads to 4)-D-Glc). The urine sample is first fractionated by gel chromatography. An appropriate internal standard is added to the pooled tri-pentasaccharide fraction, which is then reduced, methylated and fractionated by g.c. The identification of the tetrasaccharide derivative is based on the g.c. relative retention time and the mass spectrum of the reduced permethylated tetrasaccharide. The normal excretion rate was in the range of 0.1-2.5 mg per 24 hours. Greatly increased amounts (9.4-89.6 mg 24 h-1) were found in the urine of patients with glycogen storage disease type II and type III and in one patient with unclassified muscular disease. A moderate increase (3.6m6 mg 24 h-1) was observed in one patient with glycogen storage disease type VI, in two patients with Duchenne muscular dystrophy and in two other patients with unclassified muscular disease.

Adolescent↗
PubMed1975

Glycosidases in human skin fibroblast cultures. Alpha-fucosidase, alpha-galactosidase, alpha-glucosidase, beta-mannosidase, and N-acetyl-alpha-glucosaminidase.

Five glycosidases, alpha-fucosidase, alpha-galactosidase, alpha-glucosidase, beta-mannosidase and N-acetyl-alpha-glucosaminidase were studied in human skin fibroblast cultures. The pH-dependency, kinetic properties of the enzymes and results of isoelectric focusing and ion exchange chromatography are presented. Techniques suitable for diagnosing inborn lysosomal diseases in skin fibroblast cultures are defined.

Adolescent↗