This book is one of our contemporary medical bibles. It needs no introduction; those who have frequent need of it know it very well, and those who use it less often seek it out on the library shelf when problems arise. The book is truly encyclopedic. Everything relevant discovered during the six-year intervals between publication finds its way into these pages. By today's standards, its 1,778 closely packed small-print pages are a bargain. The mutant gene is both hero and villain in this book. It is reponsible for the biochemical abnormality that results in disease, no matter how rare a given abnormality may be. By the same token, however, it is truly an experiment of nature, shedding light on fundamental metabolic sequences and biologic mechanisms. This volume, more than most, explains the contributions of the laboratory to clinical medicine. Each chapter seems to have been rewritten, so that the exciting

The Metabolic Basis Of Inherited Disease.

Multiple Sulfatase Deficiency Is Caused by Mutations in the Gene Encoding the Human Cα-Formylglycine Generating Enzyme

Sustained release polymeric gene delivery systems offer increased resistance to nuclease degradation, increased amounts of plasmid DNA (pDNA) uptake, and the possibility of control in dosing and sustained duration of pDNA administration. Furthermore, such a system lacks the inherent problems associated with viral vectors. Biodegradable and biocompatible poly(DL-lactide-co-glycolide) polymer was used to enacapsulate pDNA (alkaline phosphatase, AP, a reporter gene) in submicron size particles. Gene expression mediated by the nanoparticles (NP) was evaluated in vitro and in vivo in comparison to cationic-liposome delivery. Nano size range (600 nm) pDNA-loaded in poly(DL-lactide-co-glycolide) polymer particles with high encapsulation efficiency (70%) were formulated, exhibiting sustained release of pDNA of over a month. The entrapped plasmid maintained its structural and functional integrity. In vitro transfection by pDNA-NP resulted in significantly higher expression levels in comparison to naked pDNA. Furthermore, AP levels increased when the transfection time was extended, indicating sustained activity of pDNA. However, gene expression was significantly lower in comparison with standard liposomal transfection. Seven days after i.m. injections in rats, naked pDNA and pDNA-NP were found to be significantly more potent (1-2 orders of magnitude) than liposomal pDNA. Plasmid DNA-NP treatment exhibited increased AP expression after 7 and 28 days indicating sustained activity of the NP.

Sustained delivery and expression of DNA encapsulated in polymeric nanoparticles.

Sialidosis: a review of human neuraminidase deficiency.

The GM2 Gangliosidoses

Neuraminidase deficiency towards fetuin, 2→3 sialyllactose and 2→6 sialyllactose was found in cultured skin fibroblasts from a 10-year-old Japanese girl who exhibits craniofacial dysmorphism, a short neck, vertebral and pelvic deformities and macular cherry-red spots. Neuraminidase deficiency in this case seems the primary enzyme defect because the enzyme activity of her parents was intermediate. In addition, β-galactosidase in leukocytes and cultured skin fibroblasts from the patient was found to be severely deficient, but could be detected in serum and urine. In the parents, β-galactosidase activity was normal. There were moderately increased levels of urinary sialic acid-rich oligosaccharides and glycopeptides in the patient. The clinical and biochemical observations suggest that this case is very close to mucolipidosis I.

A case of neuraminidase deficiency associated with a partial β-galactosidase defect

Hypersialyloligosacchariduria in mucolipidoses: a method for diagnosis.

The addition of 88 mM sucrose to the culture medium of human skin fibroblasts from normal subjects caused remarkable increase in the intracellular lysosomal hydrolase activities. The mechanism of this induction by sucrose loading was carefully studied with several fibroblast strains of different inherited lysosomal storage disorders. In single lysosomal hydrolase defect such as GM1-gangliosidosis, mannosidosis and Sandhoff disease, no induction of the deficient hydrolase was found with 88 mM sucrose loading. In contrast, sucrose loading caused normalization of intracellular lysosomal hydrolase activities in I-cell disease fibroblasts and cytoplasmic inclusion materials disappeared. Subsequent investigations reveal that I-cell disease cells are classified into three subgroups by the degree of hydrolase induction by sucrose loading; a high responding, an intermediate responding and a no-response group. The heterogeneity may be based upon different induction by sucrose loading of the enzyme, probably the residual phosphotransferase which is involved in the processing steps of lysosomal enzyme molecules. With the addition of mannose-6-phosphate and 10 mM NH4Cl to cultured skin fibroblasts, it was shown that sucrose loading caused increased synthesis of lysosomal enzyme proteins. The result of the test with 2,4-dinitrophenol suggests that sucrose is indeed pinocytosed by cultured human skin fibroblasts and localized in lysosomes and that this event is the essential factor to trigger the induction of lysosomal hydrolases. Simultaneous loading of both invertase and sucrose in cultured cells caused no induction of α-mannosidase activity. This result indicates that invertase is also pinocytosed, reaches the lysosomes and hydrolyzes sucrose in the lysosomes. Lysosomal overloading with sucrose resulted in induction of lysosomal hydrolases and invertase blocked the induction of α-mannosidase activity. However, some induction still exists in β-galactosidase and α-fucosidase activity. Thus it is very likely that the induction of lysosomal hydrolases demands a complicated process. In this article, we investigated the effects of sucrose on the lysosomal hydrolases in cultured human skin fibroblasts of several inherited lysosomal storage disorders and normal subjects and discuss the possible mechanism. of the induction of lysosomal hydrolase activities by sucrose loading.

The effects of sucrose loading on lysosomal hydrolases

Rectal mucosa biopsy specimens from patients with neuronal storage diseases were examined by electron microscopy. The diseases were Tay-Sachs disease, Sandhoff's disease, Niemann-Pick disease types B and C, late infantile metachromatic leukodystrophy, GM1 gangliosidosis type 1, beta-galactosidase-neuraminidase deficiency, I-cell disease, and mucopolysaccharidoses (Hunter's syndrome and Sanfilippo's syndrome type A). Unmyelinated nerve fibers, endothelial cells, fibroblasts, plasma cells, and histiocytes were seen in the specimens. Except for plasma cells, the results thus obtained for various cells were similar to those obtained from skin and conjunctival biopsy specimens, which have been already reported. There has been no report so far on ultrastructure of the plasma cell in these diseases. Storage materials, eg, dense bodies and membrane-bound vacuoles, were observed in the plasma cells in various storage diseases, with the exception of late infantile metachromatic leukodystrophy. Thus, electron microscopy of rectal mucosa is useful in making diagnoses and examining plasma cells in some neuronal storage diseases.

Tomochika Kato

Papers

A case of neuraminidase deficiency associated with a partial β-galactosidase defect

Hypersialyloligosacchariduria in mucolipidoses: a method for diagnosis.

The effects of sucrose loading on lysosomal hydrolases

Ultrastructural study of biopsy specimens of rectal mucosa. Its use in neuronal storage diseases.

beta-Galactosidase deficient-type mucolipidosis: a complementation study of neuraminidase in somatic cell hybrids.