[Effects of myostatin and other growth factors on cultured human cells]. / Vliianie miostatina i nekotorykh rostovykh faktorov na kul'tiviruemye kletki cheloveka.

A dedicated cell-based biological test system was used for studying specific effects of myostatin and other human growth factors on the proliferation of cultured myoblasts and fibroblasts. Myostatin inhibited myoblast growth without affecting human fibroblasts. In this test system, human growth hormone and insulin-like growth factor I acted as antagonists of myostatin, which indicates that these agents have a potential for blocking its effects in vivo.

[Program for diagnosis and prevention of inherited metabolic diseases of cellular organelles]. / Prgramma diagnostiki i profilaktiki nasledstvennykh boleznei obmena kletochnykh organell.

A programme for diagnosis and prevention of lysosomal, peroxisomal, and mitochondrial [respiratory chain diseases (RCD)] diseases was developed on clinical, biochemical, and molecular approaches. The authors made postnatal diagnosis was made in 674 patients from 516 families and prenatal diagnosis in 124 fetuses in 94 families at risk. DNA analysis of mutant alleles in the mucopolysaccharidoses (MPS) I, II, and VI revealed 14, 13, and 4 new mutant alleles in IDS, ASB, IDUA genes, respectively. The pressure of a mutation process played a major role in the distribution of mutant alleles leading to MPS I and VI, but along with this factor genetic drift and migration undoubtedly influenced the observed spectrum of IDUA alleles in Russia. A clinical phenotype of patients with different MPS was analyzed on the basis of uniform registration of 167 symptoms and signs in 249 patients. Special statistical approaches were developed to characterize early manifestations of different MPS and "unique" signs and symptoms for many of them and "phenotypic distances" between them. The similar problems were solved for RCD through uniform registration of 110 symptoms and signs in 54 patients with different syndromes: pathognomonic symptoms for the whole RCD and "unique" symptoms for syndromes were defined.

Postnatal and prenatal diagnosis of lysosomal storage diseases in the former Soviet Union.

Diagnosis and prevention of lysosomal storage diseases (LSD) in the former Soviet Union (FSU) is based on the interaction of various local counselling units with the Department of Inherited Metabolic Diseases (DIMD) at the Research Center of Medical Genetics (RAMS). Work began in 1982 using standard, as well as newly developed biochemical techniques. 25 different LSD were diagnosed in 445 patients from 404 families. 106 pregnancies in families at risk were monitored prenatally, and 25 affected fetuses were diagnosed and aborted. The clinical spectrum of diagnosed lysosomal storage diseases (LSD) was surprisingly heterogeneous. Besides classical forms of LSD numerous atypical forms were discovered. They included juvenile and adult forms of some sphingolipidoses manifesting as progressive dystonia, spinocerebellar degeneration and hebephrenic schizophrenia, as well as an atypical form of mucolipidosis III in which the clinical phenotype bore an obvious resemblance to that of mucopolysaccharidosis (MPS) VI. The incidence of MPS was much higher than that of other LSD. It was evaluated as 1:15000 for two regions of the FSU. This investigation revealed some peculiarities of the ethnic distribution of MPS in populations of the FSU and supported the high prevalence of the gene for Tay-Sachs disease gene in Ashkenazi Jews.

First-trimester enzyme exclusion of Farber disease using a micromethod with [3H]ceramide.

Farber disease was diagnosed in a patient with typical features and ceramide accumulation in lipogranulomatous nodules. [3H]Ceramide with high specific activity was prepared and used to confirm diagnosis in the patient after her death and for prenatal studies in this family. A micromethod was developed for ceramidase assay in chorionic villi.

[Biochemical genetics of peroxisomal disorders]. / Biokhimicheskaia genetika peroksisomnykh boleznei.

This review is the first one dealing specifically with a class of peroxisomal disorders that remain virtually unfamiliar to Russian medical genetic consultants and pediatricians. Data are presented that concern classification, genetics, characterization of clinical and biochemical phenotype, prevention, and therapy of 18 nosological units included in the class of peroxisomal disorders. Problems of general biological significance are reviewed, which can be solved using peroxisomal disorders as a valuable experimental model.

High-resolution loading tests in the study of genetic heterogeneity in gangliosidosis fibroblasts.

GM1- and GM2-gangliosides were isolated from brain and radiolabelled. The labelled moieties were localized by hydrolysis with lysosomal enzymes, followed by thin-layer chromatography of the products. High-resolution loading tests with labelled gangliosides were developed and found to differentiate infantile and juvenile forms of GM1- and GM2-gangliosidoses as well as the identification of B, O and AB types of GM2-gangliosidosis.

[A program of prevention of hereditary lysosomal diseases in the USSR]. / Programma profilaktiki nasledstvennykh lizosomnykh boleznei v SSSR.

The organization of genetic counselling for the families of patients with lysosomal storage diseases (LSD) was based on the interaction of the genetic counselling units of this country with a laboratory of inherited metabolic diseases of the National Research Center of Medical Genetics, USSR AMS. All the patients from 705 families at risk were examined using biochemical techniques and methods of somatic cell genetics. In total the loci differentiation was performed for 309 patients with mucopolysaccharidoses, glycoproteinoses, mucolipidoses, sphingolipidoses and other LSD. 53 families at risk (of 277) were prenatally diagnosed. 66 fetuses were diagnosed for mucopolysaccharidoses, type I, II, III, A and B, VI, Tay-Sachs disease, Sandhoff's disease, GM1-gangliosidosis, metachromatic leukodystrophy, mannosidosis, and multiple sulfatidosis. In total 18 affected fetuses were diagnosed and aborted. All the prenatal diagnoses were verified. The prevalence of mucopolysaccharidoses in two Central Asian republics was evaluated as 1:15,000. An Uneven ethnic distribution of different mucopolysaccharides in the USSR has also been shown.

[Isolation and characteristics of hexosaminidase A and activator protein from human kidney]. / Vydelenie i kharakteristika geksozaminidazy A i aktiviruiushchego belka iz pochki cheloveka.

Hexosaminidase A (HA) was isolated from human kidney and purified to an electrophoretically homogeneous state. The purification procedure included ion-exchange chromatography on DEAE-cellulose, gel filtration on Toyopearl HW-55 and chromatofocusing on PBE 94 (enzyme yield 26.6%, 1133.6-fold purification). The physico-chemical and kinetic properties of HA are as follows: Mr of the purified enzyme is approximately 100,000; Km for 4-methylumbelliferyl-2-acetamido-2-deoxy-beta-D-glucopyranoside is 0.6 mM; pH optimum is at pH 4.4-4.6; pI is 5.0. The amino acid composition of the purified enzyme was determined. A specific anti-HA antiserum was raised, which did not immunoprecipitate with fibroblast extracts characterized by a mutational blockade of HA synthesis. GM2 was isolated and purified from murine liver as well as from the brain of a female patient who died of Tay-Sachs disease. The label was introduced by way of treatment of GM2 with tritiated acetic anhydride. The specific radioactivity of [3H]GM2 was 521 and 2065 Ci/M, respectively. The label was introduced into the N-acetylneuraminic acid and GalNAc residues of these GM2 preparations. An activator protein capable of solubilizing the natural substrate of HA was isolated from human kidney and partially purified (with a 19.9% yield and 480-fold purification). The Mr of the purified activator protein was approximately 21,000. Purified HA hydrolyzed [3H]GM2 only in the presence of the activator protein. An addition of the activator to the incubation medium containing normal fibroblast culture extracts and [3H]GM2 caused an increase in the rate of substrate hydrolysis, tenfold, on the average.

[Study of the genetic heterogeneity of gangliosidoses in humans]. / Issledovanie geneticheskoi geterogennosti gangliozidozov u cheloveka.

A study of genetic heterogeneity of GM1 and GM2 gangliosidoses was performed using a wide set of cultured fibroblast lines of patients with leukodystrophies. In addition to commonly used methods for enzyme diagnosis and for isozyme fractionating, following assays were developed for locus and allele differentiation: loading tests with 3H-GM1 and 3H-GM2, analytical chromatofocusing and activity determination of activator protein for GM2.

[The use of loading tests with labeled GM1-ganglioside for differential diagnosis of GM1-gangliosidosis]. / Ispol'zovanie nagruzochnykh testov s pomoshch'iu mechenogo GM1-gangliozida dlia differentsial'noi diagnostiki GM1-gangliozidoza.

Kinetics of GM1-ganglioside accumulation was studied in fibroblast cultures from patients with various forms of GM1-gangliosidosis using the labelled native substrate GM1-ganglioside isolated from human brain. A shape of accumulation curves in the plot was shown to depend on GM1-ganglioside concentration in a medium in juvenile form of the disease. Use of a number of the fibroblast strains and optimal concentration of GM1-ganglioside 20 micrograms/ml enabled to carry out allele differentiation of the juvenile form of GM1-gangliosidosis from infantile and normal forms, thus suggesting that the loading tests could be applied to pre- and postnatal diagnosis of GM1-gangliosidosis.

[Prenatal diagnosis of hereditary lysosomal diseases]. / Prenatal'naia diagnostika nasledstvennykh lizosomnykh boleznei.

Prenatal diagnosis was carried out in 10 families suffering from lysosomal diseases: Tay-Sachs disease--5 families, Sandhoff disease--1 family, GM1-gangliosidosis--1 family and Hunter disease--3 families. Diagnosis of Tay-Sachs disease was excluded in fetuses of two families, Sandhoff disease--in one family, GM1-gangliosidosis--in one family, Hunter disease--in two families. Tay-Sachs disease was found in two fetuses and in one neonate. In two fetuses was found Hunter disease (twin pregnancy). The results of prenatal diagnosis were corroborated by postnatal studies of the neonates funicular blood and of autopsies of the aborted fetuses tissues. Application of several independent procedures for prenatal diagnosis of hereditary lysosomal diseases enabled to exclude erroneous diagnosis.

[Identification of GM2-gangliosidosis using an in vitro loading test]. / Identifikatsiia GM2-gangliozidozov s pomoshch'iu nagruzochnogo testa in vitro.

A test system was developed for identification of conventional and atypical forms of GM2-gangliosidoses. The test system was based on a loading test using a culture of the patients skin fibroblasts. Gangliosides, isolated from small samples (several mg) of various tissues, were identified by means of thin-layer chromatography on silica gel plates. In the loading test both unlabelled and 3H-total gangliosides from bovine and rat brain were used. Skin fibroblasts from patients with Tay-Sachs disease, with Sandhoff disease and with unidentified form of leukodystrophy were cultivated. The fibroblasts were found to metabolize the gangliosides administered into the cultivation medium. The cells from patients with GM2-gangliosidoses accumulated GM2 during incubation within 8 days.

[Dihydropteridine reductase activity in leukocytes and cultured fibroblasts of health individuals and of patients with the classical form of phenylketonuria]. / Issledovanie aktivnosti digidropteridinreduktazy v leikotsitakh i kul'tiviruemykh fibroblastakh u zdorovykh liudei i bol'nykh s klassicheskoi formoi fenilketonurii.

Activity of dihydrohypteridine reductase, estimated by means of spectrophotometric method, was found in cell culture of human fibroblasts and in leukocytes of peripheric blood. The enzymatic activity was not altered markedly with time; thus suggesting a possibility to classify dihydropteridine reductase as a constitutive enzyme. In patients with typical form of phenylketonuria the enzymatic activity tended to decrease as compared with healthy persons.