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Biomedical subjects

Y S Shin

Publications and source records attributed to Y S Shin.

At least 37 records · Page 2Linked to original sources
PubMed2000

Skeletal muscle apoptosis after burns is associated with activation of proapoptotic signals.

Critical illness is associated with muscle wasting and muscle weakness. Using burn injury as a model of local and systemic inflammatory response, we tested the hypothesis that thermal injury causes apoptosis in muscle. After a 40% body surface area burn to rats, abdominal muscles beneath the burn and limb muscles distant from the burn were examined for apoptosis at varying times after burn. Ladder assay, ELISA, and histological methods showed evidence of apoptosis in the abdominal muscles within 4-12 h with peak changes occurring at 3-7 days. Maximal apoptosis was also evident at distant limb muscles at 3-7 days. Investigation of proapoptotic pathways indicated mitochondrial membrane potential to be altered by 1 h after burn. Starting at 15 min after burn, cytochrome c was released from the mitochondria into the cytosol, followed by increased activity of caspase-3, starting at 6 h after burn. These studies suggest that mitochondria and caspase-mediated apoptotic pathways may be an additional mechanism of muscle weight loss in burns and may be potential therapeutic targets for prevention of muscle wasting.

Abdominal Muscles↗
PubMed2000

Novel missense mutations in the glycogen-branching enzyme gene in adult polyglucosan body disease.

We describe the first non-Ashkenazi patient with adult polyglucosan body disease and decreased glycogen-branching enzyme (GBE) activity in leukocytes. Gene analysis revealed compound heterozygosity for two novel missense mutations Arg515His and Arg524Gln in the GBE gene. Both missense mutations are predicted to impair GBE activity. This is the first identification of GBE mutations underlying adult polyglucosan body disease in a non-Ashkenazi family, and confirms that adult glycogen storage disease type IV can manifest clinically as adult polyglucosan body disease.

1,4-alpha-Glucan Branching Enzyme↗
PubMed1999

[Adult polyglucosan antibody disease. Case report with predominant involvement of the central and peripheral nervous system and branching enzyme defect in leukocytes].

We describe a 46 year old patient with adult polyglucosan body disease (APBD). She presented clinically with late onset pyramidal tetraparesis, sensory motor polyneuropathy and micturition difficulties. Magnetic resonance imaging of the brain revealed extensive leucencephalopathy and diffuse atrophy. The diagnosis based on the demonstration of polyglucosan bodies in the sural nerve biopsy. In search of a possible metabolic defect, we evaluated glycogen metabolism in this patient and her clinically unaffected daughters. Branching enzyme activity in the patients leukocytes was between 20-30% of the lower limit of normal range, whereas their children displayed values of 80%, suggesting a possible autosomal recessive mode of transmission. Branching enzyme deficiency in APBD with predominantly attack of the central and peripheral nervous system was so far described in 3 Jewish patients.

1,4-alpha-Glucan Branching Enzyme↗
PubMed1999

Recanalization of completely thrombosed giant aneurysm: case report.

BACKGROUND: Spontaneous recanalization in a completely thrombosed giant aneurysm is a very rare condition. CASE DESCRIPTION: An 18-year-old woman presented with a serpentine variety giant aneurysm of the posterior cerebral artery, in which spontaneous recanalization of a completely thrombosed lumen was demonstrated on magnetic resonance imaging and angiography. The patient was treated by trapping of the parent artery and aneurysmectomy. CONCLUSION: This case will provide insight into the potential for spontaneous recanalization in completely thrombosed giant aneurysms.

Adult↗
PubMed1999

Intravenous calcitriol regresses myocardial hypertrophy in hemodialysis patients with secondary hyperparathyroidism.

To evaluate the response of circulating intact parathyroid hormone (iPTH) on myocardial hypertrophy in hemodialysis (HD) patients with secondary hyperparathyroidism (SHPT), echocardiographic and neurohormonal assessments were performed over a 15-week period in 15 HD patients with SHPT before and after calcitriol treatment and 10 HD control patients with SHPT not receiving calcitriol therapy. We prospectively studied a group of 15 patients with significantly elevated iPTH levels (iPTH >450 pg/mL) receiving calcitriol (2 microg after dialysis twice weekly). Clinical assessment, medication status, and biochemical and hematological measurements were performed once a month. Throughout the study, calcium carbonate levels were modified to maintain serum phosphate levels at less than 6 mg/dL, but body weight, antihypertensive medication, and ultrafiltration dose remained constant. In patients treated with calcitriol, an adequate reduction of iPTH levels was found (1,112 +/- 694 v 741 +/- 644 pg/mL; P < 0.05) without changes in values of serum ionized calcium (iCa++), phosphate, or hematocrit. Blood pressure (BP), cardiac output (CO), and total peripheral resistance (TPR) did not significantly change. After 15 weeks of treatment with calcitriol, M-mode echocardiograms showed pronounced reductions in interventricular wall thickness (13.9 +/- 3.6 v 12.8 +/- 3.10 mm; P = 0.01), left ventricular posterior wall thickness (12.5 +/- 2.4 v 11.3 +/- 1.8 mm; P < 0.05), and left ventricle mass index (LVMi; 178 +/- 73 v 155 +/- 61 g/m2; P < 0.01). However, in control patients, these changes were not found after the treatment period. In addition, sequential measurements of neurohormonal mediator levels in patients receiving calcitriol showed that plasma renin (18.5 +/- 12.7 v 12.3 +/- 11.0 pg/mL; P = 0.007), angiotensin II (AT II; 79.7 +/- 48.6 v 47.2 +/- 45.7 pg/mL; P = 0.001), and atrial natriuretic peptide (ANP; 16.6 +/- 9.7 v 12.2 +/- 4.4 pg/mL; P = 0.03) levels significantly decreased, whereas antidiuretic hormone (ADH), epinephrine, and norepinephrine levels did not change significantly. The percent change in LVMi associated with calcitriol therapy had a strong correlation with the percent change in iPTH (r = 0.52; P < 0.05) and AT II (r = 0.47; P < 0.05) levels. We conclude that the partial correction of SHPT with intravenous calcitriol causes a regression in myocardial hypertrophy without biochemical or hemodynamic changes, such as heart rate, BP, and TPR. The changes in plasma levels of iPTH and, secondarily, plasma levels of neurohormones (especially AT II) after calcitriol therapy may have a key role in attenuating ventricular hypertrophy in SHPT.

Adult↗
PubMed1999

Epitopes and nuclear localization analyses of canine distemper virus nucleocapsid protein by expression of its deletion mutants.

A series of nucleocapsid protein (NP)-deleted genes of the Onderstepoort strain was constructed in order to locate antigenic regions of the NP of canine distemper virus. The expression of proteins from 5'-deleted NP genes was examined in COS-7 cells by indirect immunofluorescence assay using three monoclonal antibodies (MAbs), c-5, f-5 and h-6, and a rabbit serum against NP. These MAbs reacted with two regions of NP. Amino acid residues from 1 to 80, and 337-358, were necessary and sufficient for formation of the epitopes identified by MAbs f-5 and h-6, and c-5, respectively. The proteins translated from intact or 3'-deleted genes were found to be localized in the nuclei of COS-7 cells, whereas the proteins from the 5'-deleted genes were mainly detected in the cytoplasm. These results suggested that 80 amino acid residues at the N-terminus are required for transportation of NP into the nucleus.

Animals↗
PubMed1999

Clinical, fluorine-18 labeled 2-fluoro-2-deoxyglucose positron emission tomography of the brain, MR spectroscopy, and therapeutic attempts in methylenetetrahydrofolate reductase deficiency.

The cases of three infants, two Saudi and one Bahraini, with methylenetetrahydrofolate reductase (MTHFR) deficiency are reported. They presented in the neonatal period with lethargy, poor feeding, hypotonia, and frequent apneas. Tandem mass spectrometry (MS/MS) of a blood spot indicated very low methionine level and of urine revealed high homocysteine. The diagnosis was confirmed by demonstrating severe deficiency of MTHFR in the cultured skin fibroblast. All patients were treated with folinic acid, vitamin B12, betaine, and methionine, with good initial response to the therapy. In two patients, the diagnosis was late and their disease was severe, resulting in neurological crippling. However, in the third patient, who was diagnosed and treated early, the current neurological status is normal. In her case, at 1 month of age, the brain FDG PET scan documented very faint cerebral and cerebellar cortical activities. After 5 months of intensive therapy, that included 200-600 mg/kg per day methionine, she had a dramatic clinical and biochemical recovery as well as a parallel improvement in FDG PET. Brain MR spectroscopy indicated normal neuronal glial and myelin markers for her age. We conclude that the functional changes confirmed by the FDG PET study were better correlated with the clinical course of the patient and adequately monitored the response to therapy. This disease warrants early detection through neonatal screening program, since the beneficial effect of early administration of adequate therapy with combined use of betaine and a high dose of methionine is rewarding and may be the treatment of choice for MTHFR deficiency.

Brain↗
PubMed1999

[Familial cataract in plasma galactitol increase without known enzyme defect].

BACKGROUND: Several enzyme defects of the galactose pathway may lead to cataract formation. We report on a family with familiar cataract. PATIENTS: A 2-year-old Turkish girl (daughter of first cousins) presented with dense cortical and subcapsular opacifications and mature cataract respectively. Bilateral phacectomy, planned posterior capsulotomy, transpapillary vitrectomy and implantation of a posterior chamber lens were performed. The child was otherwise healthy and the pregnancy had been unremarkable. The 25-year-old mother showed circumscribed drop-like opacities of the lens cortex bilaterally, the 5-year-old sister a diffuse opacification of the lens cortex in both eyes, the 27-year-old father and the 13-year-old uncle clear lenses. RESULTS: The girl's level of galactitol was elevated to 2.8 nmol/ml in the plasma (normal values 0.25-1.13 nmol/ml) and to 3.1 nmol/mg protein in the lens (normal values 0.5-1.7 nmol/mg protein). The levels of galactose-1-phosphate in RBC and sorbitol in plasma were in the normal range. The enzyme activities of galactokinase, galactose-1-phosphate uridyl transferase, UDP-galactose epimerase and sorbitol dehydrogenase in RBC, as well as the sorbitol dehydrogenase activity in the lens were in the normal range. The sister and the uncle both had slightly elevated plasma galactitol levels. CONCLUSIONS: Cataract-formation in this family is most likely due to a defect in the galactitol pathway, e.g. cataract in galactosemia without known enzyme defect (Shin-Jakobs disease). In patients with unexplained congenital or infantile cataracts, disorders of the polyol pathway should be thoroughly checked for to ensure a therapeutic diet if necessary.

Adult↗
PubMed1999

Effects of priming with pancuronium or rocuronium on intubation with rocuronium in children.

Rocuronium is a non-depolarizing neuromuscular blocking agent which has a rapid onset and intermediate duration of action. The goal of this study was to compare the neuromuscular blocking actions of rocuronium with and without a priming dose of pancuronium or rocuronium in children. Thirty patients were randomly allocated into 3 groups. Ten patients received a single dose of 0.6 mg/kg rocuronium (Group I). The others received either 0.015 mg/kg pancuronium (Group II) or 0.06 mg/kg rocuronium (Group III) 3 minutes before an intubating dose of 0.54 mg/kg rocuronium was given. Neuromuscular blockade was measured via accelerographic response to single stimulations (1 Hz) of the ulnar nerve until maximal twitch depression was reached followed by train-of-four (TOF) stimuli (2 Hz) at 15 second intervals for the remainder of recovery. Groups were compared with regard to onset time, duration and recovery indices. The onset time and duration of block did not differ significantly between groups. However, the time to recovery in group II (24.5 +/- 9.9 min) was significantly prolonged compared to that in group I (12.7 +/- 3.1 min) or group III (12.7 +/- 3.9 min). We concluded that the use of rocuronium with a preceding dose of either pancuronium or rocuronium provided no advantage for intubation in children.

Androstanols↗
PubMed1999

The infusion rate of mivacurium or atracurium for cesarean section compared with gynecological procedures.

Mivacurium is mainly metabolized by plasma cholinesterase, whereas atracurium is removed by Hofman elimination. The purpose of this study was to compare the infusion rate of atracurium and mivacurium in maintaining surgical relaxation, and to compare their recovery indices between parturients and non-pregnant women. Muscle relaxation was maintained by the continuous infusion of relaxants to retain the first response of train-of-four (TOF) at 5% of control. When mivacurium was used, Bolus-T5 (duration from the end of mivacurium bolus injection to 5% single twitch recovery) was measured. After discontinuing the infusion, the recovery index was measured. The infusion rate of mivacurium, not atracurium, was significantly lower in parturients and Bolus-T5 of parturients was significantly longer than that of non-pregnant women. There was no significant difference in the recovery indices of both relaxants. The authors concluded that the infusion rate of mivacurium in maintaining muscle relaxation in parturients should be reduced compared to the rate in non-pregnant women and measuring Bolus-T5 may be helpful in determining the infusion rate to maintain muscle relaxation.

Adult↗
PubMed1998

Differential UDP-galactose-4'-epimerase (GALE) enzymatic activity and mRNA expression in the rat mammary gland during lactation.

We have investigated the UDP-galactose-4'-epimerase (GALE) enzymatic activity and mRNA expression in the rat mammary gland during lactation. We report a dramatic increase in the GALE enzymatic activity correlated with an increase in the mRNA transcript expression. These results indicate a transcriptional regulation of the enzyme during lactation in the rat mammary gland. Our data are of double interest for further investigation: first, the mammary gland provides a suitable model for the characterisation of the transcriptional regulation elements of GALE which are still unknown in mammals; second, GALE expression could help to compensate UDP-galactose deficiency in classic galactosaemia.

Animals↗
PubMed1998

Solution and solid phase combinatorial synthesis of peptidomimetic library containing diversified alpha-methylated amino acids.

A combinatorial peptidomimetic library containing diversified alpha-methylated amino acids was generated by the Ugi four component condensation (4cc) reaction from acids, amines, isocyanides and ketones in both solution and solid phase synthetic procedures. This one-pot methodology overall gave fair to good yields, which compare well with multi-step syntheses.

Amino Acids↗
PubMed1998

Simultaneous occurrence of various mutations and polymorphisms in cis and in trans of the galactose-1-phosphate uridyltransferase gene in a Turkish family with classical galactosemia.

Classical galactosemia, characterized clinically by acute hepatic dysfunction, sepsis, cataract, and failure to thrive, is caused by deficiency of galactose-1-phosphate uridyltransferase (GALT). Galactose restriction normalizes these acute symptoms; however, long-term complications such as intellectual deficits and ovarian failure are conspicuous in the majority of patients. Here we report two Turkish siblings with classical galactosemia. The clinical course of the two children differed markedly: only the older girl suffered from severe acute symptoms during the neonatal period, and she developed greater mental retardation than her younger affected brother. The functional activity of GALT was virtually absent in each affected children. The mother and two healthy siblings exhibited approximately 50% normal GALT activity and the father approximately 25%. Molecular analysis revealed that these two galactosemic siblings were homozygous for a stop codon mutation of E340X in GALT exon 10. Moreover, two additional mutations, a neutral polymorphism L218L and N314D, which are typical for the Duarte-I variant, were found in the same GALT allele. The two healthy siblings and the parents were heterozygous for these combinations of mutations. In addition, the father's second GALT allele revealed three intron mutations at nucleotide position 1105 (G-->C), 1323 (G-->A) and 1391 (G-->A) and the N314D mutation, which correspond to the mutations of Duarte-2 variant. Our findings indicate that in classical galactosemia several distinct mutations can be present in one allele (in cis) of the GALT gene. Therefore it seems to be necessary to examine all introns and exons of the GALT gene in galactosemic patients who do not carry the Q188R mutation or another frequent mutation in the GALT gene.

Adolescent↗
PubMed1998

A new mutation of the glucose-6-phosphatase gene in a 4-year-old girl with oligosymptomatic glycogen storage disease type 1a.

A 4-year-old German girl was diagnosed as having glycogen storage disease type la and showed no other marked symptoms except hepatomegaly. The glucose-6-phosphatase activity in the liver was approximately 1.5% to 5.0% of normal values, and molecular analysis revealed compound heterozygosity for R83C and the novel mutation N264K. This result indicates that there is a wide clinical variation of glucose-6-phosphatase deficiency. DNA analysis is helpful for confirmation of the diagnosis, as well as establishment of the genotype and phenotype correlation in glycogen storage disease type 1a.

Child, Preschool↗
PubMed1998

Infantile muscle phosphorylase-b-kinase deficiency. A case report.

A Turkish girl is described who showed a severe floppy infant syndrome and respiratory failure at birth. She suffered upper respiratory tract infections and pneumonia. She was ventilated and had hypercapnoea secondary to bradypnoea. Biochemical analysis of skeletal muscle revealed a slightly increased glycogen content, and enzymatic analysis revealed a muscle phosphorylase-b-kinase deficiency. The infant succumbed after 140 days due to persistent apnoea and asystole. Isolated muscle phosphorylase-b-kinase deficiency should be considered as a possible diagnosis in floppy infants.

Brain Diseases, Metabolic↗