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Biomedical subjects

G Strecker

Publications and source records attributed to G Strecker.

At least 181 records · Page 10Linked to original sources

[A new type of sialidosis with kidney disease: nephrosialidosis. I. Clinical, radiological and nosological study].

The term nephrosialidosis is proposed to describe a type of oligosaccharidosis in which a glomerular nephropathy develops early and causes death in the early years of life. The clinical and radiological features of the disease are dysmorphic facies, visceral storage disease, early and severe mental retardation and skeletal abnormalities of a type often described in this group of diseases. Foam cells were present in the marrow and, late in the illness, a cherry red spot was present on fundoscopy. The condition is inherited as an autosomal recessive. The leucocytes were deficient in alpha-(2-6) neuraminidase, an abnormality that has also been described in mucolipidosis type I and in other conditions quite distinct from nephrosialidosis. Thus the conditions characterised by this enzyme deficiency are definitely heterogeneous.

Eye Manifestations↗

Structure of seven oligosaccharides excreted in the urine of a patient with Sandhoff's disease (GM2 gangliosidosis-variant O).

The urine of a patient with Sandhoff's disease (GM2 gangliosidosis-variant O) contains 10--12 N-acetylglucosamine-rich oligosaccharides in high amounts. The structures of seven of these have been determined: beta-GlcNAc(1--2)-alpha-Man-(1--3)-beta-man-(1--4)-GlcNAc; beta-GlcNAc-(1--4)-alpha-Man-(1--3)-beta-Man-(1--4)-GlcNAc; beta-GlcNAc-(1--2)-alpha-Man-(1--6)-beta-Man-(1--4)-GlcNAc; beta-GlcNAc-(1--4)-alpha-Man-(1--6)-beta-Man-(1--4)-GlcNAc; beta-GlcNAc-(1--2)-alpha-Man-(1--3)-[beta-GlcNAc-(1--2)-alpha-Man-(1--6)]beta-Man-(1--4)-GlcNAc; beta-GlcNAc-(1--2)-alpha-Man-(1--3)[beta-GlcNAc-(1--2)-alpha-Man-(1--6)][beta-GlcNAc-(1--4)]beta-Man-(1--4)-GlcNAc; beta-GlcNAc-(1--2)-alpha-Man(1)-(1--3)[beta-GlcNAc-(1--2)-alpha-Man(2)-(1--6)]beta-Man-(1--4)-GlcNAc, with additional beta-GlcNAc, with additional beta-GlcNAc-(1--4) on mannose (1) or (2). An unusual oligosaccharide, with a tri-branched beta-mannose, has been characterized as the major component excreted in urine.

Acetylglucosamine↗

Structural studies on 2-acetamido-1-N-(4-L-aspartyl)-2-deoxy-beta-D-glucopyranosylamine and 2-acetamido-6-O-(alpha-L-fucopyranosyl)-1-N-(4-L-aspartyl)-2-deoxy-beta-D-glucopyranosylamine by 360-MHz proton-magnetic-resonance spectroscopy.

The 360-MHz proton magnetic resonance spectra of 2-acetamido-1-N-(4-L-aspartyl)-2-deoxy-beta-D-glucopyranosylamine (GlcNAcbeta1 leads to Asn) and 2-acetamido-6-O-(alpha-L-fucopyranosyl)-1-N-(4-L-aspartyl)-2-deoxy-beta-D-glucopyranosylamine (Fucalpha1 leads to 6GlcNAcbeta1 leads to Asn) in deuterium oxide were completely interpreted. The chemical shifts and coupling constants were refined by simulation of the spectra. By means of an adapted Karplus equation the pyranose ring conformation of the sugars was calculated. The change of the geminal coupling constant J6a,6b in the N-acetylglucosamine residue of Fucalpha1 leads to 6GlcNAcbeta1 leads to Asn with respect to GlcNAcbeta1 leads to Asn is proposed to be characteristic for the (1 leads to 6) glycosidic linkage.

Acetylglucosamine↗

Sialidosis (mucolipidosis I).

The term "sialidosis" is suggested for the deficiency of alpha-neuraminidase activity in peripheral leukocytes and cultured fibroblasts which results in a considerable urinary excretion of sialyl-oligosaccharides. This defect was found in two siblings with a mild form of mucolipidosis I. 12 sialyl-acid rich oligosacharides have been isolated from the urine of the patients. The structure of ten of them has been determined. The studies of the patients show a remarkable variability of the clinical expression of this disease. The two siblings exhibited a progressive reduction of visual acuity, red-green blindness, a bilateral cherry red macular spot, punctate opacities of the lens, and minimal neurological symptoms. Morphologically, vacuolized lymphocytes, refringent inclusions in cultured fibroblasts, numerous cytoplasmatic inclusions containing a fine protein-like reticulum and some osmiophilic granules mainly in Kupffer's cells were found.

Adolescent↗

Radioimmunoassay of the WZ polymorphic antigens of normal human colon and their relationship with ABH antigenic determinants.

Heat resistant, high mol. wt glycoproteins of the three WZ phenotypes (W+Z+, W-Z+ and W-Z-) were extracted from normal human colonic mucosa and labelled with 125I. More than 80 per cent of the radioactivity of the W+Z+ antigens labelled with I125, was precipitated by natural or immune anti-W antibodies. About 60 per cent of the W-Z+ 125I-labelled antigens were precipitated by immune anti-Z antibodies. No specific precipitation could be detected with W-Z- 125I-labelled antigens. All the precipitin reactions were quantitatively inhibited with the crude antigen extracts of the corresponding phenotypes. The W and Z antigens were only found in the intestinal mucosa and there was a 100-fold increase in the relative concentrations between the small bowel and the rectum. As opposed to this, the ABH antigens were found in all the digestive secretions studied, except those of the rectum, and their relative concentrations progressively decreased by about 100 between the small intestine and the recutm. The decrease in ABH concentration seems to be correlated to a WZ increase in the same regions.

ABO Blood-Group System↗

Deficit in neuraminidase associated with mucolipidosis II (I-cell disease).

Using a tritiated sialyloligosaccharide as a substrate, the authors showed that mucolipidosis II is characterized by a lack of neuraminidase activity in leucocytes, while the other acidic hydrolases activities are normal. According to Ashwell, terminal galactose is the required signal for glycoproteins uptake by the cells. Thus, a neuraminidase deficit may explain the increase of sialylated hydrolases activities in the plasma and the non-recognition of these enzymes by cultured fibroblasts.

Humans↗

Structure of the three major sialyl-oligosaccharides excreted in the urine of five patients with three distinct inborn diseases: "I cell disease" and two new types of mucolipidosis.

The urine of five patients with three distinct diseases ("I Cell disease" and two new types of mucolipidosis) contains sialic acid-rich oligosaccharides in a high amount: 50- to 500-fold the normal. The structure of the major components are as follows: alphaAcNeu(2 leads to 6)betaGal(1 leads to 4)betaGlcNac(1 leads to 2)alphaMan(1 leads to 3)betaMan(1 leads to 4)GlcNac,[alphaAcNeu(2 leads to 6)]betaGal(1 leads to 4)betaGlcNAc(1 leads to 2)alphaMan(1 leads to 3)[betaGal(1 leads to 4)betaGlcNac(1 leads to 2)alphaMan(1 leads to 6)]betaMan(1 leads to 4)GlcNAc and alphaAcNeu(2 leads to 6)betaGal(1 leads to 4)betaGlcNAc(1 leads to 2)alphaMan(1 leads to 3)[alphaAcNeu(2 leads to 6)betaGal(1 leads to 4)betaGlcNAc(1 leads to 2)alphaMan(1 leads to 6)]betaMan(1 leads to 4)GlcNAc. These results suggest that a deficit in alpha-neuraminidase is associated to these three different disorders and that an endo-beta-D-N-acetylglucosaminidase is able to release sialyoligosaccharides by splitting the sialylglycans of glycoproteins.

Adult↗

[Chemistry of urinary mannosides excreted in mannosidosis].

Mannose-rich oligosaccharides have been isolated from urines of 5 patients with mannosidosis. Their compositon and structure were determined. Three of them have been previously described by Norden et al: alpha p-Manp-(1 leads to 3) beta-d-Manp-(1 leads to 4) d-GlcNAcp; alpha-p-Manp-(1 leads to 2), alpha-d-Manp-(1 leads to 3) beta-d-Manp-(1 leads to 4) d-GlcNAc and alpha-d-Manp-(1 leads to 2) alpha-d-Manp-(1 leads to 2) alpha-d-Manp-(1 leads to 3) beta-d-Manp-(1 leads to 4) d-GlcNAcp, but the four others are new entities: alpha-d-Manp-(1 leads to 3) (alpha-d-Manp-(1 leads to 2) alpha-d-Manp-(1 leads to 2) alpha-d-Manp-(1 leads to 6) beta-d-Manp-(1 leads to 4) GlcNAcp; alpha-d-Manp-(1 leads to 2) alpha-d-Manp-(1 leads to 3) (alpha-d-Manp-(1 leads to 2) alpha-d-Manp-(1 leads to 6) beta-d-Manp-(1 leads to 4) GlcNAcp; alpha-d-Manp-(1 leads to 2), alpha-d-Man-(1 leads to 3) (alpha-d-Manp-(1 leads to 6) beta-d-Manp-(1 leads to 4) GlcNAp and alpha-d-Manp-(1 leads to 2) alpha-d-Manp-(1 leads to 3) (alpha-d-Manp-(1 leads to 6) beta-d-Manp-(1 leads to 4) GlcNAcp. These structures are related to the glycans of "oligomannosidic type" present in numerous glycoproteins. All possess a N-acetylglucosamine residue in terminal reducing position and reinforce the hypothesis of Kobata et al. and Montreuil et al. that catabolism of glycans N-glucosidically linked to the protein moiety begins by the aciton of a beta-endo-N-acetylglucosaminidase.

Acetylglucosamine↗

[Study of the fucose-rich oligosaccharides in the urine of healthy and melituric subjects with A, B and O blood groups].

The application of adsorption chromatography on charcoal-Celite leads the authors to characterize in normal urines a class of fucose-rich oligosaccharides which possess blood group activities and are related to the phenotypes ABH, Le and secretor. Most of these oligosaccharides have a glucose residue in reducing terminal positions. Excretion of some oligosaccharides increases in the urine of diabetic and lactosuric subjects. In spontaneous or induced galactosurias, the elimination of oligosaccharides with a glucose residue in reducing terminal position decreases while appears a large amount of new oligosaccharides which all possess a galactose residue in reducing terminal position. These results lead to the conclusion that urinary oligosaccharides do not originate from glycosphingolipids, but from transglycosylation on carbohydrates which exist free in the organism: glucose for normal and diabetic subjects, lactose or galactose for lactosuric and galactosuric subjects, respectively.

ABO Blood-Group System↗

[Structure and immunochemical properties of the urinary oligosaccharides excreted during induced galactosuria].

Induced galactosuria is characterized by the excretion in urine of large amounts of new oligosaccharides, the structure of which are in connection with blood-group phenotypes ABH, Lewis and Secretor: O group : O-alpha-L fucopyranosyl-(1 leads to 2)-D galactopyranose et O-alpha-L fucopyranosyl-(1 leads to 2)-O-beta-D galactopyranosyl-(1 leads to 3)-[O-alpha-L fucopyranosyl-(1 leads to 4)]-O-beta-D 2-deoxy-2 acetamido-glucopyranosyl-(1 leads to 4)-[O-alpha-L fucopyranosyl-(1 leads to 6)]-D-galactopyranose. A group: O-alpha-D-2-deoxy-2 acetamido-galactopyranosyl-(1 leads to 3)-[O-alpha-L fucopyranosyl-(1 leads to 2)]-D galactopyranose et O-alpha-D-2-deoxy-2 acetamido-galactopyranosyl-(1 leads to 3)-[O-alpha-L fucopyranosyl-(1 leads to 2)]-O-beta-D galactopyranosyl-(1 leads to 3)-[O-alpha-L fucopyranosyl-(1 leads to 4)]-O-beta-D-2-deoxy-2 acetamido-glucopyranosyl-(1 leads to)-[O-alpha-L fucopyranosyl-(1 leads to 6)]-D galactopyranose. B group : O-alpha-D galactopyranosyl-(1 leads to 3)-[O-alpha-L fucopyranosyl-(1 leads to 2)]-D galactopyranose et O-alpha-D galactopyranosyl-(1 leads to 3)-[O-alpha-L fucopyranosyl-(1 leads to 2)]-O-beta-D galactopyranosyl-(1 leads to 3)-[O-alpha-L fucopyranosyl-(1 leads to 4)]-O-beta-D-2-deoxy-2 acetamido-glucopyranosyl-(1 leads to 4)-[O-alpha-L fucopyranosyl-(1 leads to 6)]-D-galactopyranose.

ABO Blood-Group System↗

[Mannonidosis. Apropos of 5 cases].

Mannosidosis remains an extremely rare entity (9 published cases). Our personal experience, based upon 5 cases, suggests that the diagnosis may be based upon both positive as well as negative clinical and paraclinical data, which differentiate the disorder from other diseases which it resembles. The use of simple methods--thin layer chromatography of oligosaccharides and measurement of serum mannosidase at pH 3.5 and 4.5--render diagnosis easy. It should, however, be mentioned that there exists no valid treatment for this apparently autosomal recessive disorder but that ante-natal detection is theoretically possible.

Bone and Bones↗