I-cell disease (Mucolipidosis II).

I-cell disease (Mucolipidosis II) is one of the lysosomal storage diseases which presents in the neonatal period, and within six months will phenotypically resemble the severe forms of the group of disorders called the "mucopolysaccharidoses" but without mucopolysacchariduria. In Mucolipidosis II, fibrocytes exhibit "abnormal lysosomes". Activities of several lysosomal enzymes are low in fibroblast cultures but high in mucolipidosis II serum. We present a patient with I-cell disease diagnosed on the basis of clinical, radiological and biochemical features. The mother of this child was pregnant and the fetus was also found to be affected.

Effect of 2-deoxy-D-glucose on metabolism of glycosaminoglycans in normal and hypercholesterolemic rats.

Carbohydrates are the integral parts of glyco-conjugates and play an important role in cellular functions. 2-Deoxy-D-glucose (2-dGlc) is a sugar analogue of glucose and mannose and is reported to inhibit the lipid-linked saccharide formation involved in N-linked glycosylation of proteins. Administration of 2-dGlc (1 mg/100 g body weight) produced a decrease in the tissue total glycosaminoglycans level. We found that the activity of the enzymes involved in the biosynthesis of precursors of glycosaminoglycans (GAG) decreased, but that of the degrading enzymes increased. Thus, the decreased levels of GAG in tissues in 2-dGlc-administered rats occurs via enhanced degradation as well as decreased synthesis.

Determinación de la actividad enzimática de la hexosaminidasa en fluidos biológicos / Determination of the enzimatic activity of hexosaminidase in biological fluids

Este estudio describe un método electroforético que emplea el sustrato fluorogénico 4-metilumbelliferil 2-acetamida 2-deoxi-ß-D-glucopiranosido, para determinación enzimática de la hexosaminidasa (HEX) en linfocitos de sangre períferica, líquido amniótico, suero y orina. Se propone que la electroforésis sirva como método confirmatorio del diagnóstico de la gangliosidosis GM2, ya que permite determinar la actividad enzimática de la HEX y hacer la diferenciación de las isoenzimas (HEX A y HEX B). La deficiencia de estas isoenzimas se detecta por disminución o ausencia de fluorescencia

Enzyme studies in GM2 gangliosidiosis, and their application in prenatal diagnosis.

Assay of hexosaminidase A and B enzymes in four cases with developmental regression and cherry red spot on fundus examination confirmed that three cases had Tay-Sachs disease, and one case had Sandhoff disease. Prenatal diagnosis was carried out by hexosaminidase enzyme assay in amniotic fluid and cells in one family, and chorionic villus sample in the second family. The fetus was diagnosed to be unaffected in one, and affected in the other family. Assay of hexosaminidase A and B is useful for specific diagnosis of GM2 gangliosidosis, and for prenatal diagnosis to reduce the burden of these disorders.

Aortic/glycosaminoglycans alterations in antiatherogenic action of dietary fiber from unripe banana (Musa paradisiaca).

Dietary fiber isolated as neutral detergent residue from unripe banana altered the concentration of aortic glycosaminoglycans in rats fed cholesterol free and cholesterol diet. Concentration of hyaluronic acid (9.9%), heparan sulphate (53.4%), chondroitin 4-sulphate (32.6%), chondroitin 6-sulphate (17.9%), dermatan sulphate (18.8%) and heparin (10.1%) increased in the aorta in rats fed cholesterol free diet. In rats fed cholesterol diet, concentration of heparan sulphate (23.3%), chondroitin 4-sulphate (9.8%) and heparin (42.4%) increased while hyaluronic acid showed a decrease (29.7%). The activity of beta-glucuronidase (9.5%) and beta-hexosaminidase (19.7%) decreased in the aorta in rats fed cholesterol free diet and given dietary fiber, while only beta-hexosaminidase (19.3%) decreased in rats fed cholesterol diet.