ABSTRACT
To investigate the prevalence and genetic characteristics of myotonic dystrophy type 1 (DM1) in Taiwan, DM-suspected patients and their families identified during the period of 1990-2001 had their clinical records reevaluated and the CTG repeat sizes at the DM1 locus examined. A total of 96 subjects belonging to 26 families were identified as DM1 patients, which gave a minimal disease prevalence of 0.46/100,000 inhabitants. Clinical anticipation was frequently observed in affected families, even in some parent-child pairs with transmission contraction of the CTG repeat size. The inverse correlation between age at onset and CTG repeat length was significant only in patients with small expansions. In addition, a DM1 carrier with a childhood-onset son was found to have CTG length heterogeneity in the range of 40-50, indicating that premutation alleles could be unstable during gametogenesis as well as in somatic tissues. Our data demonstrated that DM1 is a rare disease in Taiwan and showed that transmission contraction of repeat size is more likely to occur in alleles with large repeats.
Subject(s)
Myotonic Dystrophy/epidemiology , Myotonic Dystrophy/genetics , Adolescent , Adult , Age of Onset , Aged , Aged, 80 and over , Child , Child, Preschool , DNA/blood , DNA/genetics , Female , Humans , Infant , Male , Middle Aged , Polymerase Chain Reaction , Taiwan/epidemiology , Trinucleotide Repeats/geneticsABSTRACT
This paper describes a highly interactive virtual reality orthopedic surgery simulator. The simulator allows surgeons to use various surgical instruments to operate on virtual rigid anatomic structures, such bones, prostheses and bone grafts, to simulate every procedure on the rigid structures for complex orthopedic surgeries, including arthroplasty, corrective or open osteotomy, open reduction of fractures and amputation. A comparative study of the simulator with paper simulation was performed and showed that interns and residents found the simulator to be a useful learning tool, and that visiting doctors could use it effectively for planning verification and rehearsal of operations.
Subject(s)
Computer Simulation , Computer-Assisted Instruction , Orthopedic Procedures , Orthopedics/education , User-Computer Interface , Amputation, Surgical , Arthroplasty , Arthroplasty, Replacement, Knee , Fracture Fixation , Humans , Osteotomy , Software , Spinal FusionABSTRACT
1. To study the role of protein kinase C (PKC) in the increase in manganese superoxide dismutase (Mn-SOD) gene expression following transient hypoxia in glial cells, we examined the mRNA levels of Mn-SOD using northern blot analysis. 2. The Mn-SOD mRNA levels were markedly increased after exposure to nitrogen gas for 5 min. 3. Pretreatment with chelerythrine or GF109203x, inhibitors of PKC, attenuated the increase in Mn-SOD mRNA following hypoxia in a concentration-dependent manner. 4. Incubation with phorbol 12-myristate 13-acetate, the PKC activator, enhanced the increase in Mn-SOD gene expression in response to transient hypoxia. 5. The results suggest that hypoxia increases Mn-SOD gene expression in cultured glial cells mainly through activation of a PKC pathway.
Subject(s)
Gene Expression Regulation , Neuroglia/enzymology , Protein Kinase C/biosynthesis , Superoxide Dismutase/biosynthesis , Superoxide Dismutase/genetics , Cell Hypoxia/drug effects , Cell Hypoxia/physiology , Cells, Cultured , Enzyme Inhibitors/pharmacology , Neuroglia/drug effects , RNA, Messenger/biosynthesisABSTRACT
Myotonic dystrophy (DM) is an inherited, autosomal dominant muscular disease which is primarily caused by a CTG trinucleotide expansion mutation on chromosome 19q13.3. The size of this trinucleotide repeat is related both to the age of onset and to the severity of the clinical manifestation. This disease is very rare in Taiwan, and clinical and genetic study on DM has not yet been documented in this area. Here, we present both clinical features and degrees of CTG expansion for a Taiwanese DM family. All of the DM patients examined in this family showed obvious clinical manifestations by age 30, which included facial and limb muscle weakness with atrophy, myotonia, and ptosis. In addition, individual DM members also exhibited variable phenotypes, which may reflect the complexity of the pathogenic mechanism. Because the collection of blood specimens was considered to be an invasive procedure, a genetic study on this DM family was performed using buccal cells. Our results confirmed that four members showing classic symptoms of DM had CTG repeat expansion in the DMI locus, and that one member with ptosis and minor muscle weakness in the right foot was a normal homozygote for CTG repeat. These data demonstrate that buccal cells can provide clear and reliable results, and thus, are suitable for a family study of DM.
Subject(s)
Myotonic Dystrophy/genetics , Trinucleotide Repeat Expansion , Alleles , Blotting, Southern , Female , Genotype , Humans , Male , Mouth Mucosa/ultrastructure , Myotonic Dystrophy/epidemiology , Pedigree , Phenotype , Polymerase Chain Reaction , Taiwan/epidemiologyABSTRACT
Changes of adenosine A-1 receptor (A1-AR) gene expression in aging were investigated in cerebral cortex using the rat aged from 2 months (adult) to 24 months (aged). Quantification of A1-AR protein level by immunoblotting analysis showed an age-related decrease of A1-AR in cerebral cortex of Wistar rats. Compared to the preparations from 2-month-old animals, the levels of A1-AR in the 6-, 12-, and 24-month-old rats were reduced by 14.3+/-5.2, 32.5+/-4.5 and 28.2+/-5.7%, respectively. Similar decrease of mRNA level in A1-AR was also obtained using Northern blotting analysis. Two representative spots of mRNA, a 3.4-kb transcript and a 5.6-kb transcript, were observed in X-ray film from cerebral cortex of rat hybridized with rat A1-AR cDNA probe. Compared to the 2 month-old rats, levels of the 5.6-kb transcript were decreased by 17.9+/-2.5, 27.4+/-3.2 and 23.1+/-2.1% in the 6-, 12- and 24-month-old rats, respectively. These results indicated an age-related decrease of A1-AR in cerebral cortex of the rat that seems responsible for the change of response to adenosine.
Subject(s)
Aging/genetics , Aging/metabolism , Cerebral Cortex/metabolism , Down-Regulation/genetics , Gene Expression Regulation , Receptors, Purinergic P1/biosynthesis , Receptors, Purinergic P1/genetics , Animals , Blotting, Northern , Blotting, Western , Brain Chemistry/genetics , Cerebral Cortex/physiology , Male , Rats , Rats, Wistar , Receptors, Purinergic P1/isolation & purificationABSTRACT
Myotonic dystrophy (DM) is caused by a CTG trinucleotide expansion mutation at exon 15 of the myotonic dystrophy protein kinase gene. The clinical severity of this disease correlates with the length of the CTG trinucleotide repeats. Determination of the CTG repeat length has been primarily relied on by Southern blot analysis of restriction enzyme-digested genomic DNA. The development of PCR-based Southern blotting methodology provides a much more sensitive and simpler protocol for DM diagnosis. However, the quality of the template and the high (G+C) ratio of the amplified region hamper the use of PCR on the diagnosis of DM. A modified PCR protocol to amplify different lengths of CTG repeat region using various concentrations of 7deaza-dGTP has been reported (1). Here we describe a procedure including sample collection, DNA purification, and PCR analysis of CTG repeat length without using 7-deaza-dGTP. This protocol is very sensitive and convenient because only a small number of nucleate cells are needed for detection of CTG expansion. Therefore, it could be very useful in clinical and prenatal diagnosis as well as in prevalence study of DM.
Subject(s)
DNA/chemistry , Oligonucleotides , Repetitive Sequences, Nucleic Acid , Blood Specimen Collection , Blotting, Southern , Cell Line , DNA/isolation & purification , Humans , Polymerase Chain Reaction , Reagent Kits, Diagnostic , Sensitivity and SpecificityABSTRACT
In order to understand the role of superoxide dismutase (SOD) in response to transient hypoxia or hypoxia-reperfusion in astrocytes, the present study performed an in vitro investigation using rat glial cells in culture. Hypoxia was induced by an incubation with nitrogen gas for 10 min and that followed a further reperfusion with air for 10 min was indicating as hypoxia-normoxia. Activity of SOD was determined by the reduction of nitroblue tetrazolium (NTB). Changes of mRNA for Cu,Zn-SOD or Mn-SOD were also characterized using Northern blotting analysis. Transient hypoxia increased the activity of Mn-SOD but not that of Cu,Zn-SOD in glial cells. Expression of mRNA for SOD was also elevated in cells received hypoxia and the mRNA level for Mn-SOD raised higher than that for Cu,Zn-SOD. In cells received hypoxia-reperfusion, these changes of SOD both the activity and the mRNA level were not observed. Otherwise, the SOD protein amount, both Cu,Zn-SOD and Mn-SOD, identified by Western blotting was not changed in glial cells receiving hypoxic stress or not. The obtained results suggest that gene expression and activity of Mn-SOD in glial cells can be activated in response to the transient hypoxic stress.
Subject(s)
Neuroglia/metabolism , RNA, Messenger/biosynthesis , Superoxide Dismutase/biosynthesis , Animals , Autoradiography , Blotting, Western , Cell Hypoxia/physiology , Cells, Cultured , Enzyme Activation , Gene Expression Regulation , Neuroglia/cytology , Neuroglia/enzymology , Rats , Superoxide Dismutase/geneticsABSTRACT
In an attempt to understand the role of free radicals in the regulation of sympathetic neurotransmission, the in vitro secretion of noradrenaline (NA) from synaptosomal preparations of guinea-pig ileum was investigated. Release of endogenous NA was quantified by an electrochemical detection (HPLC-ECD). In the presence of superoxide dismutase (SOD) and catalase at concentrations sufficient to scavenge the free radicals, secretion of NA was attenuated in samples with stimulation of 4-aminopyrine (4-AP) or not (spontaneous release). However, inducing superoxide radicals via the reaction of hypoxanthine with xanthine oxidase failed to modify the secretion of NA, both the 4-AP-stimulated release and the spontaneous secretion. Then, free radicals were induced in synaptosomes using hypoxia-normoxia exposure. Secretion of NA was markedly increased in samples receiving this treatment in a calcium-dependent way because it was attenuated by the removal of calcium chloride from bathing medium. An increase of SOD activity, both Mn-SOD and Cu, Zn-SOD, was also obtained by this exposure. Changes of SOD activities in response to free radicals produced by hypoxia-normoxia exposure in ileal synaptosomes can thus be considered. In conclusion, these results suggest that free radicals are formed to involve in the regulation of sympathetic neurotransmission via an increase of calcium influx to enhance the NA release in guinea-pig ileum.
Subject(s)
Ileum/metabolism , Myenteric Plexus/metabolism , Norepinephrine/metabolism , Presynaptic Terminals/metabolism , Animals , Catalase/metabolism , Female , Free Radicals , Guinea Pigs , Hypoxanthine/metabolism , Ileum/innervation , In Vitro Techniques , L-Lactate Dehydrogenase/metabolism , Male , Superoxide Dismutase/metabolism , Synaptosomes/enzymology , Synaptosomes/metabolism , Xanthine Oxidase/metabolismABSTRACT
In an attempt to understand the change of superoxide dismutase (SOD) in tumor cells by hypoxia and hypoxia-normoxia exposure, the present study performed an in vitro investigation using rat glioma cell line in culture. Hypoxia was induced by an incubation with nitrogen gas for 15 h followed the normoxia exposure with air for 30 min. Activity of SOD in cytosolic and particulate of cells was determined by the reduction of nitroblue tetrazolium. Changes of mRNA for Cu,Zn-SOD or Mn-SOD were also characterized using Northern blotting analysis. Hypoxic stress decreased the activity of SOD, both Cu,Zn-SOD and Mn-SOD, in glioma cells. Expression of mRNA for SOD was elevated by hypoxic stress and the increase of mRNA level for Cu,Zn-SOD was more marked than that for Mn-SOD. In response to hypoxia-normoxia exposure, an increase of activity with a lower mRNA level for Mn-SOD was observed in glioma cells. However, changes of Cu,Zn-SOD both the activity and the level of mRNA were not found in glioma cells by hypoxia-normoxia. The obtained results suggest that the SOD in glioma cells can be activated to compensate the damage from free radicals during hypoxic stress.
