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Biomedical subjects

Y S Shin

Publications and source records attributed to Y S Shin.

At least 19 recordsLinked to original sources
PubMed1992

Mevalonate kinase assay using DEAE-cellulose column chromatography for first-trimester prenatal diagnosis and complementation analysis in mevalonic aciduria.

Mevalonic aciduria due to mevalonate kinase deficiency, an inherited defect of cholesterol biosynthesis, has presented with clinical variability in 10 patients from 7 families. We sought to define a genetic basis for this heterogeneity by determining mevalonate kinase activity in fibroblast heterokaryons obtained by polyethylene glycol fusion. To this end we developed a DEAE-cellulose (Cl-) column chromatography procedure for assessing mevalonate kinase in cell extracts that would allow multiple rapid analyses. Fusion of control fibroblasts with those from affected patients from six families with mevalonate kinase deficiency yielded 37% of the mean control activity. None of the fusions between the six cell lines of patients resulted in measurable mevalonate kinase activity. Using the chromatographic procedure, we developed an optimized assay for mevalonate kinase in biopsied chorionic villi. Km values for chorionic villi were similar to those obtained in fibroblasts. Mevalonate kinase activity in biopsied chorionic villi showed a linear increase (0.75-4.3 nmol/min per mg protein) with gestational age from 7 to 14 weeks. Using the optimized assay in biopsied chorionic villi we performed a first-trimester prenatal diagnosis in a pregnancy at risk for mevalonate kinase deficiency and correctly diagnosed an unaffected fetus. The availability of an optimized assay for mevalonate kinase in biopsied chorionic villi should allow reliable first-trimester prenatal diagnosis for families at risk.

Chorionic Villi↗
PubMed1992

A mild juvenile variant of type IV glycogenosis.

The mild juvenile form of type IV glycogenosis, confirmed by a profound deficiency of the brancher enzyme in tissue specimens is reported from three Turkish male siblings who, foremost, suffered from chronic progressive myopathy. Muscle fibers contained polyglucosan inclusions of typical fine structure i.e. a mixture of granular and filamentous glycogen. They reacted strongly for myophosphorylase, but were resistant to diastase. These inclusions were ubiquitinated and reacted with antibody KM-279 which previously has been shown to bind to Lafora bodies, corpora amylacea and polyglucosan material in hepatic and cardiac cells of type IV glycogenosis as well as polyglucosan body myopathy without brancher enzyme deficiency. Our findings confirm that although rate, a mild form of type IV glycogenosis is marked by polyglucosan inclusion not only in myofibers, but also in smooth muscle and sweat gland epithelial cells. This further implies that when polyglucosan inclusions are observed within myofibers it is mandatory to examine the muscle tissue for brancher enzyme activity since the brancher enzyme activities in circulating erythrocytes and leucocytes were normal in all three affected siblings and their parents. Therefore, it can be concluded that the patients reported on here represent a variant form of type IV glycogenosis, in which the defect is limited to muscle tissue. This further indicates that there are several different types of type IV glycogenosis with variable clinical manifestations.

Child↗
PubMed1992

Adult polyglucosan body myopathy.

This report describes a sporadic late-onset myopathy in two unrelated adults which was marked by polyglucosan inclusions surrounded by abnormally structured mitochondria, the latter finding a localized, possibly reactive phenomenon. The polyglucosan material was characterized by a battery of histochemical and enzyme histochemical techniques; revealed common antigenicity with Lafora bodies, corpora amylacea and muscle fiber inclusions in types IV and VII glycogenoses; and contained ubiquitin. Additional lectin histochemical and associated digestion preparations disclosed the presence of alpha-glycosyl residues as apparently the sole carbohydrate component in polyglucosan bodies while the above mentioned common antigenicity with Lafora bodies and other inclusions suggests an additional, so far unidentified, protein component.

Atrophy↗
PubMed1992

Identification of a feline immunodeficiency virus gene which is essential for cell-free virus infectivity.

Feline immunodeficiency virus (FIV) contains at least three small open reading frames (ORFs) in the genome, in addition to the three structural genes. Two of these ORFs (putative vif and ORF-A) have unknown functions. Northern (RNA) blot analysis of mRNAs from an FIV-infected cell line showed that the putative-vif-specific mRNA was expressed as a 5.2-kb species. To examine the function of the putative vif gene, we constructed mutants carrying a deletion in either the vif-like gene or the rev gene from an infectious molecular clone of FIV. Although the vif mutant produced virion-associated reverse transcriptase at a normal level upon transfection, cell-free virus prepared from the transfected cells could not infect feline CD4+ cells. The infectivity of the vif mutant, however, was demonstrated in a coculture of the transfected cells and feline CD4+ cells. We conclude that FIV contains the vif gene, which is structurally and functionally similar to that of the primate lentiviruses.

Base Sequence↗
PubMed1992

Modification of atracurium or vecuronium blockade and their reversal by succinylcholine in the cat.

The interaction between succinylcholine (SCC) and non-depolarizers, atracurium or vecuronium was investigated in 36 cats of either sex using the sciatic nerve-anterior tibialis muscle preparation. Additionally, the relation of SCC to pseudocholinesterase activity was examined. The duration of action of vecuronium (6.5 +/- 1.3 to 7.3 +/- 2.2 minutes) in cats pretreated with SCC was greater than those (2.0 +/- 0.6 minutes) in non-pretreated cats. However, SCC had no influence on the duration of atracurium. The serum pseudocholinesterase activity was decreased after the injection of atracurium or neostigmine in contrast to vecuronium. The authors conclude that the prior administration of SCC prolongs the duration of vecuronium but not that of atracurium, and pseudocholinesterase activity is not related to the prolonging effect of SCC.

Animals↗
PubMed1991

Production of infectious particles from defective human immunodeficiency virus type 1 (HIV-1)-producing cell clones by superinfection with infectious HIV-1.

A total of 81 cell clones persistently infected with the LAV-1 or HTLV-IIIB strain of human immunodeficiency virus type 1 (HIV-1) was isolated from cells which were obtained by serial passage of some proliferating MT-4 cells after a drastic cytolysis of most cells by HIV-1-infection. These cell clones were classified into 8 types (I to VIII) in terms of the expression of HIV-1 antigens, syncytium formation capacity, and reverse transcriptase activity and infectivity of virus particles in the culture fluid. Type I cell clones were producers of infectious HIV-1 particles, while types II to VIII cell clones did not produce infectious HIV-1 or were producers of uninfectious defective HIV-1 particles. Immunoprecipitation followed by SDS-polyacrylamide gel electrophoresis (PAGE) showed that the gag precursor protein in L-2 cell clone (type IV) was not cleaved to mature gag proteins, while the env precursor protein on L-3 cell clone (type III) was not cleaved to mature env protein. H-7 cell clone (type VIII) did not express any HIV-1 antigen. All these cell clones after the superinfection with infectious HIV-1 synthesized intact gag and env proteins, which were, at least in part, related to the HIV-1 genome persistently present in the cell clones before the superinfection, resulting in production of infectious HIV-1. For example, it was found that L-2 cell clone contained a single copy of the LAV-1 genome per haploid cell and produced doughnut-shaped particles. On the other hand, the cell clone isolated from the L-2 cell clone superinfected with infectious HTLV-IIIB contained the integrated HTLV-IIIB genome in addition to the LAV-1 genome present before the superinfection, and produced intact HIV-1 particles in addition to doughnut-shaped particles from a single cell. These results indicate that complementation and/or genetic recombination events in the superinfected cells may account for the production of infectious intact HIV-1 virions.

Animals↗
PubMed1991

Pharmacokinetics, neuromuscular effects, and biodisposition of 3-desacetylvecuronium (Org 7268) in cats.

The pharmacokinetics, biodisposition, and neuromuscular blocking properties of 3-desacetylvecuronium were studied in 17 adult cats. Animals were divided into three groups: five cats with kidney failure induced by bilateral ligation of the renal pedicles, six cats with galactosamine-induced fulminant hepatitis, and six control cats. An intravenous bolus of 300 micrograms.kg-1 of 3-desacetylvecuronium was rapidly injected into the jugular vein. Arterial blood, urine, and bile samples were collected at regular intervals for 6 h in control cats and for 8 h in cats with kidney or liver failure. The liver was excised for analysis at the end of the experiment. In cats with renal failure, 3-desacetylvecuronium pharmacokinetic and pharmacodynamic variables did not differ from those in control cats. In cats with liver failure, plasma clearance was significantly less and mean residence time greater than in control cats (2.8 +/- 0.6 vs. 14.1 +/- 6.5 ml.kg-1.min-1 and 334 +/- 225 vs. 49 +/- 29 min, mean +/- SD, respectively). Volume of distribution at steady state in cats with liver failure and in control cats was not different. Also, in cats with liver failure, the duration of action and recovery index of 3-desacetylvecuronium was significantly greater than in control cats (168 +/- 62 vs. 82 +/- 32 min, and 39 +/- 19 vs. 10 +/- 4 min, respectively). Onset time of neuromuscular blockade was similar in all three groups. Total recovery of 3-desacetylvecuronium, for all three groups, in urine, bile, and liver was 90 +/- 11% (mean +/- SD). In control cats, 70 +/- 18% of 3-desacetylvecuronium was recovered in bile and liver and 19 +/- 14% in urine. No 3,17-bidesacetylvecuronium (a putative 3-desacetylvecuronium metabolite) was detected.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1990

[Prenatal diagnosis of genetic diseases].

Many severe genetic disorders can be identified in utero to offer parents the option to terminating the pregnancy und preventing the birth of an affected child. Various techniques of gaining tissues or cells for prenatal testings are available such as fetal blood or liver sampling, amniocentesis and chorionic villous sampling (CVS). The first step of the diagnosis is at the cell function level which involves the identification of accumulated or missing metabolites in amniotic fluid by chemical methods. The second step is to study the protein function, biochemical analysis of blood cells, cultured amniocytes and direct or cultured chorionic villi. The third step is the molecular genetic, the deoxyribonucleic acid (DNA) analysis in fetal cells or tissues. The recently developed first-trimester CVS procedure represents a rapid and safe diagnosis in utero.

Abortion, Eugenic↗
PubMed1990

Diagnosis of glycogen storage disease.

Glycogen storage diseases are associated with more than 15 different enzyme deficiencies and can be clinically divided mainly into two groups, those that affect primarily the liver and those that affect principally the muscle. In this report each glycogenosis has been clinically and biochemically documented and possibilities for an accurate and prompt diagnosis of the various types have been summarized. Most of the patients suffering from type II, type III, type IV and type VIa can easily be diagnosed by analysis of peripheral blood cells without the need for tissue biopsies. First trimester diagnosis using chorionic villi is feasible for severe forms of the glycogenoses, type IIa, type IIIa and type IV.

Blood Glucose↗
PubMed1990

Cataract and metabolic disease.

In addition to the already recognized metabolic diseases which have been associated with cataract formation, e.g. galactosaemia, galactokinase deficiency, Lowe's syndrome and diabetes, several other disorders can also lead to the development of cataracts. They are sorbitol dehydrogenase deficiency, uridine diphosphate galactose-4-epimerase deficiency, marginal maternal transferase and galactokinase deficiency, galactitol and sorbitol accumulation of unknown origin, heterozygosity for galactosaemia and galactokinase deficiency as well as the carrier state for Lowe's syndrome. In this review these metabolic disorders have been divided into five groups according to the age at the first appearance of lens clouding and the possible means of treatment have been discussed.

Adult↗
PubMed1990

Plasma polyol levels in patients with cataract.

Galactitol and sorbitol concentrations in plasma were determined in patients (with or without cataract) in whom homo- or heterozygosity for galactokinase, galactose-1-phosphate uridyltransferase, systemic or peripheral UDP-galactose epimerase and sorbitol dehydrogenase deficiency was confirmed. For the above disorders it can be concluded that elevation of plasma polyols is not always related to the presence or absence of cataract. In all cases with cataract, however, the plasma galactitol or sorbitol levels were elevated. In another group of patients with unexplained congenital or infantile cataracts, but without apparent enzyme defects, mild to moderately elevated concentrations of plasma galactitol or sorbitol were found in about 45%. In 8% of this group the cataract and the elevated plasma galactitol concentration could possibly have been related to partial maternal enzyme deficiency. In all the other cases the elevated plasma polyol concentration remains unexplained but could indicate a further cause of cataract formation due to a hitherto unknown galactose or glucose metabolic aberration.

Carbohydrate Epimerases↗