Papers by Natte Raksadawan
Genetic Testing, Jun 1, 2001
Among Ashkenazi Jewish individuals with mucolipidosis IV (ML IV), two mutations in the ML IV gene... more Among Ashkenazi Jewish individuals with mucolipidosis IV (ML IV), two mutations in the ML IV gene, IVS3-1A R G and delEX1-EX7, account for more than 95% of disease alleles. The reported method of genotyping for the delEX1-EX7 mutation involves a cumbersome multistep procedure. In the present study, a new simplified one-step procedure is described that detects this mutation in both patients and carriers. An improved procedure is also described for detection of the IVS3-1A R G mutation. Using these improved procedures, we have characterized the ML IV mutant alleles in 27 patients and 95 of their relatives from 22 families, and in 123 unrelated and unaffected Ashkenazi Jewish controls. Of the 27 ML IV patients, 16 patients (59.3%) were found to be homozygous for the IVS3-1A R G mutation and 1 patient (3.7%) homozygous for the delEX1-EX7 mutation. Additionally, 9 patients (33.3%) were compound heterozygotes for IVS3-1A R G/delEX1-EX7. Among the 123 Ashkenazi Jewish controls, two individuals were identified as heteroallelic with one IVS3-1A R G mutation (carrier frequency: approximately 1 in 61); none showed the delEX1-EX7 mutation. The modifications described here provide a more facile means of genotyping patients and carriers and expand the possibilities for screening at-risk populations.
Neuroscience, Sep 1, 2002
öTyrosine hydroxylase (TH) and brain-derived neurotrophic factor (BDNF), expressed in normal astr... more öTyrosine hydroxylase (TH) and brain-derived neurotrophic factor (BDNF), expressed in normal astrocytes, were used in combination for the treatment of Parkinson's disease (PD) symptoms in a rat model. Normal neonatal rat astrocytes were co-transfected with a vector expressing BDNF (AAVBDNF) and a retroviral vector expressing TH (termed TH-BDNF-DA þ cells), and then implanted into the striatum of PD rats induced by 6-hydroxydopamine. TH-BDNF-DA þ cells compensated for a severe insu⁄ciency of endogenous dopaminergic neurons in the PD rats, resulting in a signi¢cant improvement of PD symptoms. The decrease in the rotational rate of PD rats implanted with TH-BDNF-DA þ cells was more marked than that in PD rats implanted with normal astrocytes expressing either TH or BDNF alone (termed TH þ and BDNF þ cells, P 6 0.01 and 0.001, respectively), and suggested a synergistic e¡ect between TH and BDNF. In contrast, the rotational rate was not altered from the baseline in PD rats without treatment or implanted with parental rat astrocytes alone (P s 0.05). BDNF protected the dopaminergic neurons from apoptosis induced by 6-hydroxydopamine, and signi¢cantly increased the long-term survival of TH-positive cells in the striatum. Our data indicate that the combined use of TH and BDNF has a synergistic therapeutic e¡ect, and is more e⁄cient for the treatment of PD than a single gene therapy using either TH or BDNF alone.
PubMed, Aug 1, 2002
The authors share experiences in taking care of 27 cases of childhood onset myasthenia gravis (MG... more The authors share experiences in taking care of 27 cases of childhood onset myasthenia gravis (MGS). In all cases, the diagnosis was confirmed by a combination of clinical examination and Neostigmine test. The majority (92%) had localized ocular myasthenia with median onset of symptoms at 33 months of age. About 24 per cent of them progressed to generalized MGS. A few (8%) presented with respiratory failure that required ventilatory support with onset of symptoms at about 22 months. Thymectomy was performed in 10 cases. Complete and partial remissions were achieved in about 70 per cent and 26 per cent of cases respectively with the combination of an immunosuppressant (azathioprine) and a Cholinesterase inhibitor (pyridostigmine). None experienced a myasthenic crisis with proper management and good follow-up using the above combinations.
Journal of the Medical Association of Thailand = Chotmaihet thangphaet, 2006
Floppy infant syndrome (FIS) refers to a condition wherein an infant manifests generalized hypoto... more Floppy infant syndrome (FIS) refers to a condition wherein an infant manifests generalized hypotonia since birth or in early life. It is heterogeneous and can be caused by various central nervous system disorders, neuromuscular diseases and genetic disorders. X-linked myotubular myopathy (XMTM) is a progressive congenital myopathy morphologically characterized by the presence of centrally placed nuclei in numerous muscle fibers without any other particular pathological abnormalities. Patients are frequently born with floppiness and respiratory distress. The vast majority of patients carry a truncating or missense mutation in MTM1. The authors report here a full term male baby with clinicopathological features of XMTM. The diagnosis is validated by the finding of a c. 141-144delAGAA mutation ofMTM1. To the best of the authors' knowledge, the present case is the first genetically confirmed XMTM in Thailand. A brief review of various neuromuscular disorders causing floppy infant sy...
Chest surgery clinics of North America, 2001
Forty years ago, a patient with MG probably had a fifty-fifty chance of surviving a myasthenic cr... more Forty years ago, a patient with MG probably had a fifty-fifty chance of surviving a myasthenic crisis, defined as the need for mechanical ventilatory support. Approximately 16% of all patients experience a crisis, a figure that has not changed appreciably since then. Progressive weakness, oropharyngeal symptoms, refractoriness to anticholinesterase medication, intercurrent infection, and invasive procedures including needle biopsies of thymic gland masses, and reactions to contrast agents used in the performance of CT of the chest have been implicated in the development of crisis. It is now standard practice to treat severe crisis in an intensive care unit. The ready availability of intensive care in most hospitals belies the fall in the mortality of myasthenic crisis to 6% over the past several decades. Crisis is a temporary exacerbation, regardless of the proximate cause, and the goal is to keep the patient alive until it subsides, usually in 2 weeks. In the past, edrophonium was ...
Neuroscience, 2002
The jerky flow of Al-Mg alloys is investigated during tensile tests at imposed strain rate and ro... more The jerky flow of Al-Mg alloys is investigated during tensile tests at imposed strain rate and room temperature. The strain and strain rate dependences of the magnitude of the stress drops, the range of plastic instability and the critical strain for the onset of serrations are studied in connection with the Mg content. In the low strain rate part of the strain rate range of instability, the critical strain decreases with the Mg content. The critical strain rate corresponding to the minimum of the critical strain vs. applied strain rate curve shifts to larger values when the Mg content increases. This behavior leads to an enlargement of the strain rate domain of inverse behavior of the critical strain, at the expense of the domain of normal behavior. In the high strain rate part of the range of instability, the critical strain does not depend on the Mg content. These results are discussed in accordance with dynamic strain aging mechanisms.
Muscle & Nerve, 2006
Distal myopathy with rimmed vacuoles (DMRV) is an early-adult-onset, distal myopathy caused by a ... more Distal myopathy with rimmed vacuoles (DMRV) is an early-adult-onset, distal myopathy caused by a mutation of the UDP-N-acetylglucosamine 2 epimerase/N-acetylmannosamine kinase (GNE) gene. We herein report four Thai patients with DMRV who carried compound heterozygous mutations of the GNE gene including three novel (p.G89R, p.P511T, and p.I656N) and two known mutations (p.A524V and p.V696M). All patients shared p.V696M in one allele. Our study demonstrates the mutation spectrum of the GNE gene in Thai patients with DMRV.
Genetic Testing, 2001
Among Ashkenazi Jewish individuals with mucolipidosis IV (ML IV), two mutations in the ML IV gene... more Among Ashkenazi Jewish individuals with mucolipidosis IV (ML IV), two mutations in the ML IV gene, IVS3-1A R G and delEX1-EX7, account for more than 95% of disease alleles. The reported method of genotyping for the delEX1-EX7 mutation involves a cumbersome multistep procedure. In the present study, a new simplified one-step procedure is described that detects this mutation in both patients and carriers. An improved procedure is also described for detection of the IVS3-1A R G mutation. Using these improved procedures, we have characterized the ML IV mutant alleles in 27 patients and 95 of their relatives from 22 families, and in 123 unrelated and unaffected Ashkenazi Jewish controls. Of the 27 ML IV patients, 16 patients (59.3%) were found to be homozygous for the IVS3-1A R G mutation and 1 patient (3.7%) homozygous for the delEX1-EX7 mutation. Additionally, 9 patients (33.3%) were compound heterozygotes for IVS3-1A R G/delEX1-EX7. Among the 123 Ashkenazi Jewish controls, two individuals were identified as heteroallelic with one IVS3-1A R G mutation (carrier frequency: approximately 1 in 61); none showed the delEX1-EX7 mutation. The modifications described here provide a more facile means of genotyping patients and carriers and expand the possibilities for screening at-risk populations.
Neurologic Clinics, 2001
The therapy of myasthenia gravis and inflammatory myopathy are discussed in detail in this articl... more The therapy of myasthenia gravis and inflammatory myopathy are discussed in detail in this article. The discussion of these two disorders illustrates the extraordinary progress that has been achieved in the therapy of neuromuscular disease.
Raw data from body composition analysis from 5 to 16 year of age: Child5to16.csv Raw data of grip... more Raw data from body composition analysis from 5 to 16 year of age: Child5to16.csv Raw data of grip strength and gait speed for whole muscle prediction by multiple linear equation: WholeMuscle.csv
Clinical Neurology and Neurosurgery, 2009
Dysferlinopathy refers to a variety of autosomal recessive, skeletal muscle disorders due to the ... more Dysferlinopathy refers to a variety of autosomal recessive, skeletal muscle disorders due to the mutations of dysferlin-encoding gene, DYSF. It encompasses limb-girdle muscular dystrophy type 2B (LGMD2B), Miyoshi myopathy (MM), distal myopathy with anterior tibial onset (DMAT), isolated hyperCKemia, rigid spine syndrome and congenital muscular dystrophy. Herein, we report five Thai patients with distal myopathy due to dysferlinopathy including four MM and one DMAT patients. Muscle biopsy from one MM patient depicted numerous ring fibers which is an atypical finding in dysferlinopathy. Mutation analysis of DYSF revealed novel compound heterozygous mutations of p.Tyr309X and c.236+1G>T in two related MM patients, known homozygous mutations, p.Arg89X and p.Gln176X, in two MM patients and a heterozygous missense mutation, p.Arg555Trp, in a DMAT patient. Most of the previously reported DMAT patients were Hispanic. To the best of our knowledge, this is the first report of genetically confirmed patients with dysferlinopathy in Thailand.
Journal of the Medical Association of Thailand Chotmaihet Thangphaet, Feb 1, 2006
Floppy infant syndrome (FIS) refers to a condition wherein an infant manifests generalized hypoto... more Floppy infant syndrome (FIS) refers to a condition wherein an infant manifests generalized hypotonia since birth or in early life. It is heterogeneous and can be caused by various central nervous system disorders, neuromuscular diseases and genetic disorders. X-linked myotubular myopathy (XMTM) is a progressive congenital myopathy morphologically characterized by the presence of centrally placed nuclei in numerous muscle fibers without any other particular pathological abnormalities. Patients are frequently born with floppiness and respiratory distress. The vast majority of patients carry a truncating or missense mutation in MTM1. The authors report here a full term male baby with clinicopathological features of XMTM. The diagnosis is validated by the finding of a c.141-144delAGAA mutation of MTM1. To the best of the authors' knowledge, the present case is the first genetically confirmed XMTM in Thailand. A brief review of various neuromuscular disorders causing floppy infant syndrome is also included.
Journal of the Medical Association of Thailand = Chotmaihet thangphaet
The authors share experiences in taking care of 27 cases of childhood onset myasthenia gravis (MG... more The authors share experiences in taking care of 27 cases of childhood onset myasthenia gravis (MGS). In all cases, the diagnosis was confirmed by a combination of clinical examination and Neostigmine test. The majority (92%) had localized ocular myasthenia with median onset of symptoms at 33 months of age. About 24 per cent of them progressed to generalized MGS. A few (8%) presented with respiratory failure that required ventilatory support with onset of symptoms at about 22 months. Thymectomy was performed in 10 cases. Complete and partial remissions were achieved in about 70 per cent and 26 per cent of cases respectively with the combination of an immunosuppressant (azathioprine) and a Cholinesterase inhibitor (pyridostigmine). None experienced a myasthenic crisis with proper management and good follow-up using the above combinations.
The authors share experiences in taking care of 27 cases of childhood onset myasthenia gravis (MG... more The authors share experiences in taking care of 27 cases of childhood onset myasthenia gravis (MGS). In all cases, the diagnosis was confirmed by a combination of clinical examination and Neostigmine test. The majority (92%) had localized ocular myasthenia with median onset of symptoms at 33 months of age. About 24 per cent of them progressed to generalized MGS. A few (8%) presented with respiratory failure that required ventilatory support with onset of symptoms at about 22 months. Thymectomy was performed in 10 cases. Complete and partial remissions were achieved in about 70 per cent and 26 per cent of cases respectively with the combination of an immunosuppressant (azathioprine) and a Cholinesterase inhibitor (pyridostigmine). None experienced a myasthenic crisis with proper management and good follow-up using the above combinations.
Journal of the Medical Association of Thailand = Chotmaihet thangphaet, 2002
The authors share experiences in taking care of 27 cases of childhood onset myasthenia gravis (MG... more The authors share experiences in taking care of 27 cases of childhood onset myasthenia gravis (MGS). In all cases, the diagnosis was confirmed by a combination of clinical examination and Neostigmine test. The majority (92%) had localized ocular myasthenia with median onset of symptoms at 33 months of age. About 24 per cent of them progressed to generalized MGS. A few (8%) presented with respiratory failure that required ventilatory support with onset of symptoms at about 22 months. Thymectomy was performed in 10 cases. Complete and partial remissions were achieved in about 70 per cent and 26 per cent of cases respectively with the combination of an immunosuppressant (azathioprine) and a Cholinesterase inhibitor (pyridostigmine). None experienced a myasthenic crisis with proper management and good follow-up using the above combinations.
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Papers by Natte Raksadawan