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N Tachi

Publications and source records attributed to N Tachi.

At least 55 records · Page 3Linked to original sources
PubMed1997

De novo mutation of Charcot-Marie-Tooth disease type 1A.

Charcot-Marie-Tooth disease type 1A (CMT 1A) is an autosomal dominant demyelinating polyneuropathy associated with a 1.5-Mb duplication of the p11.2-p12 region of chromosome 17, including the peripheral myelin protein-22 (PMP-22) gene (CMT 1A duplication). We report a male patient with a de novo CMT 1A diagnosed on clinical, electrophysiologic, and molecular grounds. Motor nerve conduction velocity (MCV) of the patient was 10.9 m/s in the ulnar nerve. The MCV of both his parents was within the normal range. Southern blot analysis of BamHI digestion showed reduced intensity rate of SF85/PMP-22, indicating CMT 1A duplication. Haplotype analysis with pVAW4093a, demonstrated that the de novo CMT 1A duplication was of paternal origin.

Blotting, Southern↗
PubMed1997

Detection of the mutation in facioscapulohumeral muscular dystrophy patients.

The gene responsible for facioscapulohumeral muscular dystrophy (FSHD) was mapped to chromosome 4q35 by linkage analyses. Recently, the probe p13E-11 derived from the cosmid clone 13E, which has been mapped to 4qter, detected a polymorphic EcoRI fragment, usually greater than 28 kb in normal individuals. In sporadic and familial FSHD patients, a specific shorter fragment, usually smaller than 28 kb, was found to cosegregate with FSHD. Two FSHD patients are presented here. Patient 1 is a sporadic case of FSHD with healthy parents. He had a de novo mutation identified by Southern blot analysis using the above-mentioned probe. Patient 2 is a typical familial FSHD patient clinically and histologically. A rearranged and shortened EcoRI fragment was identified by molecular analysis. Southern blot analysis using the probe p13E-11 also indicated a rearranged EcoRI fragment in both patients.

Alleles↗
PubMed1997

Is family history an independent risk factor for stroke?

OBJECTIVE: To estimate the influence of family history on the occurrence of stroke. METHODS: A case-control study was carried out from August 1992 to January 1994. The study population comprised 502 patients with a first stroke, aged between 20 and 70 years, who were treated at 48 affiliated hospitals. The same number of age and sex matched controls were selected from outpatients. Diagnoses were based on CT findings and clinical signs. There were 155 case-control pairs for subarachnoid haemorrhage, 158 for intracerebral haematoma, and 159 for cerebral infarction. Information about the patients and their families was obtained from a questionnaire which included the family histories of each subtype of stroke and other potential risk factors for stroke. The data were analysed focusing on the role of the family histories in the occurrence of stroke. RESULTS: In univariate analysis, the family histories of subarachnoid haemorrhage and intracerebral haematoma were positively associated with each of the subtypes of stroke (odds ratios 11.24 for subarachnoid haemorrhage, 2.39 for intracerebral haematoma), whereas family history of cerebral infarction was not a significant risk factor for its occurrence (odds ratio 1.41). Family history of intracerebral haematoma was correlated with a personal history of hypertension and habitual alcohol consumption. After adjustment for potential risk factors (hypertension, diabetes, hyperlipidaemia, obesity, alcohol consumption, and regular smoking), family history of subarachnoid haemorrhage still remained the most powerful risk factor for subarachnoid haemorrhage, whereas family history of intracerebral haematoma no longer showed a significant association with haematoma. CONCLUSION: Genetic factors play a major part in the pathogenesis of subarachnoid haemorrhage, and family history of subarachnoid haemorrhage is the strongest independent risk factor for the disease. On the other hand, family history of intracerebral haematoma was not an independent risk factor for haematoma, but it might be a good predictor, which indirectly influences the pathogenesis of intracerebral haematoma via certain hereditary components such as hypertension, and even lifestyle factors such as alcohol consumption. In cerebral infarction, genetic factors play a minor part in its pathogenesis.

Adult↗
PubMed1997

Deficiency of syntrophin, dystroglycan, and merosin in a female infant with a congenital muscular dystrophy phenotype lacking cysteine-rich and C-terminal domains of dystrophin.

Primary deficiency of merosin is the cause of the classic form of congenital muscular dystrophy (CMD) accompanied by brain white matter abnormalities. We report a female infant with dystrophinopathy who was deficient in merosin in skeletal muscle. The patient had a phenotype of typical CMD and white matter abnormalities on brain MRI. Merosin was greatly reduced in the biopsied skeletal muscle. However, the expression of dystroglycan and syntrophin was also greatly reduced, and the immunoreactivity for the antibodies against the cysteine-rich/C-terminal domains of dystrophin was absent in the sarcolemma. Reverse transcriptase polymerase chain reaction analysis of the dystrophin gene revealed a complete lack of exons 71 through 74. In skeletal muscle, only the mutant gene was expressed. These results suggest that the patient is a symptomatic Duchenne muscular dystrophy carrier with skewed X-inactivation. This patient illustrates for the first time that a dystrophin abnormality can cause a secondary deficiency of merosin in dystrophinopathy. The reduction of merosin may account for the clinical phenotype of CMD and correlate with the white matter abnormalities in our patient.

Base Sequence↗
PubMed1997

[Locations of crossover breakpoints within the CMT 1 A-REP repeat in patients with hereditary neuropathy with liability to pressure palsy--detection by recombinant chromosome-specific polymerase chain reaction].

The crossover breakpoints for hereditary neuropathy with liability to pressure palsies (HNPP) are located in the CMT 1 A-REP repeat flanking a 1.5 Mb region of chromosome 17p11.2-12. Three-unrelated HNPP patients have breakpoints in a 3.2 kb novel fragment of recombinant chromosome in the CMT 1 A-REP repeat. The fragment is detected by recombinant chromosome-specific polymerase chain reaction (PCR). Further analysis of PCR demonstrated a 1.2 kb novel junction fragment in the 3.2 kb region in all HNPP patients. The precise mapping of the breakpoints indicated that 2 patients were localized in a 700 bp interval of the 1.2 kb fragment 1.3kb telomeric to a marier transposon-like element (Kiyosawa and Chance, HMG 5: 745-753, 1996), suggesting that this region is a recombinational "hotspot" within the CMT 1 A-REP repeat for HNPP as well as CMT 1 A.

Adult↗
PubMed1997

[Vitreous surgery for macular hole followed membrane peeling].

We performed vitreous surgery for macular holes following membrane peeling. The cases were five eyes of five females aged 42 to 67 years at the time of membrane peeling, out of 441 eyes of 414 patients who underwent membrane peeling. One eye had secondary epiretinal membrane combined with ocular sarcoidosis, two eyes had idiopathic epiretinal membrane, and two eyes had idiopathic vitreoretinal traction syndrome. The presumed interval from membrane peeling to macular hole formation was 5 to 90 months (average 14 months). For treatment of the macular holes, membrane peeling and SF6 gas tamponade were performed. In four eyes of the five eyes, the macular hole was closed. In the remaining eye, removal of the retinal pigment epithelium from the base of macular hole and application of fibrin glue were used in addition to SF6 gas tamponade, but the macular hole was not closed. The follow-up term was 10-24 months (average 17.6 months). Geometrical mean visual acuity was 0.34 before membrane peeling, 0.94 at maximum after membrane peeling, 0.19 after macular hole formation, 0.51 at maximum after macular hole surgery, and 0.44 at the final visit.

Adult↗
PubMed1997

[Localization of DM-PK in normal and myotonic dystrophy muscles].

Myotonic dystrophy (DM) is an autosomal-dominant, multi-system disorder characterized by myotonia, progressive muscleatrophy and weakness. DM is also associated with smooth muscle, cardiac muscle, lens, endocrine and central nervous system abnormalities. The phenotypic expression of DM varies from asymptomatic adults to severely affected neonates. The genetic basis for DM is the expansion of a CTG repeat in the 3' end of a transcript that encodes a protein with putative serine/threonine protein kinase (myotonic dystrophy protein kinase, DM-PK). The predicted molecular weight of the full-length human DM-PK is about 69 kDa, while it may have some isoforms. DM-PK expression is observed in neuromuscular junction, muscle spindle, and sarcoplasm on both normal and DM muscles. Other muscular dystrophies, such as Duchenne and Becker type, DM-PK is intensively expressed in cytoplasm on immature regenerating fibers.

Adult↗
PubMed1996

A new mutation of the Po gene in patients with Charcot-Marie-Tooth disease type 1B: screening of the Po gene by heteroduplex analysis.

Most of Charcot-Marie-Tooth (CMT) 1 families are associated with a duplication in chromosome 17p11.2-p12, which includes the gene encoding peripheral myelin protein-22 (PMP-22). Point mutations of the Po gene have been identified in a few of the CMT 1 families in whom no duplication was found. We investigated a new mutation of the Po gene in one of those families. A to G substitution of nucleotide 389 in exon 3 resulted in Lys 131 Arg substitution. This structural change of extracellular domain of Po would alter the function of Po and result in an impairment of peripheral myelin compaction.

Adult↗
PubMed1996

Vitrectomy for diffuse macular edema in cases of diabetic retinopathy.

PURPOSE: To ascertain the effects of posterior vitreous detachment for diffuse diabetic macular edema. METHODS: We performed vitrectomy on 58 eyes of 41 consecutive patients with diabetic macular edema without posterior vitreous detachment. Follow-up was done at 12 months postoperatively. RESULTS: In 57 of 58 eyes after vitrectomy and posterior vitreous detachment, macular edema resolved, and diffuse fluorescein leakage disappeared in 35 of 36 eyes examined at the 12th month. Visual improvement was statistically significant (P < .0001, paired t test). CONCLUSION: In eyes with diffuse diabetic macular edema and without posterior vitreous detachment, vitrectomy with posterior vitreous detachment may be effective.

Adult↗
PubMed1996

Truncated XPA protein detected in atypical group A xeroderma pigmentosum.

XPA protein from a patient with typical group A xeroderma pigmentosum (XP) and three atypical group-A XP patients were analysed. Immunoblot analysis of XPA proteins revealed that a typical group-A XP patient showed no XPA protein band, while a smaller, truncated XPA protein, which appears to be responsible for mid skin lesions and minimal neurological abnormalities, was detected in cells from three atypical group-A XP patients. Furthermore, the difference in the amount of truncated XPA protein correlated with the mildness of neurological manifestations in these three atypical group-A XP patients. The results suggest a correlation between clinical manifestations and qualitative and quantitative abnormalities of XPA protein products.

Adolescent↗
PubMed1996

CTG repeat size and histologic findings of skeletal muscle from patients with congenital myotonic dystrophy.

An approximate correlation has been demonstrated between the degree of CTG repeat expansion and clinical severity among myotonic dystrophy patients. Congenital myotonic dystrophy, which is the most severe form of the disease, has the largest size of CTG repeat. Muscle immaturity is a characteristic finding in congenital myotonic dystrophy muscle. We compared the CTG repeat size and histologic findings of skeletal muscle from patients with congenital myotonic dystrophy. An 8.6 kb or 9.8 kb plus an expanding band ranging from 15 kb to 17.5 kb was observed in muscle from five patients with congenital myotonic dystrophy by Southern blot analysis using EcoRI-digested DNAs probed with p5B1.4. There was no correlation between immaturity of skeletal muscle and the degree of CTG repeat expansion on skeletal muscle. Undetermined maternal factors may have an important role in the cause of immaturity of muscle in congenital myotonic dystrophy patients.

Blotting, Southern↗
PubMed1996

[DNA diagnosis in myotonic dystrophy].

Myotonic dystrophy (DM) is an autosomal-dominant, multisystemic disorder characterized by myotonia, progressive muscle atrophy and weakness, cardiac conduction defect, mental retardation, and cataracts. The phenotypic expression of DM varies from asymptomatic adults to severely affected neonates with congenital DM (CDM). DM shows genetic anticipation, an increase in disease severity and earlier age of onset in successive generations. The molecular basis of DM mutation is an unstable trinucleotide (CTG) repeat located in the 3' end of a transcript that encodes a myotonin-protein kinase. Normal populations have 5 to about 30 CTG repeats, where DM patients have 50-2,000 such repeats. The CTG repeat number is expanded in DM patients when transmitted from parent to child severity. An approximate correlation has been demonstrated between the degree of CTG repeat expansion and clinical severity. The largest repeat sizes are disclosed in CDM. Furthermore, we presented haplotype analysis of CDM families and disclosed localization of myotonic dystrophy protein kinase in DM muscle. DM kinase mRNA was decreased in various tissues of CDM patient.

Haplotypes↗
PubMed1996

Immunocytochemical localization of myotonin protein kinase on muscle from patients with congenital myotonic dystrophy.

Using a polyclonal anti myotonin-protein kinase (M-PK) antibody against synthetic M-PK peptides corresponding to part of the amino acid sequence, and the immunohistochemical analysis of indirect immunoperoxidase, we have investigated localization of M-PK on muscle from patients with congenital myotonic dystrophy. In congenital myotonic dystrophy (MD) patients, one month and 3 months old, M-PK was weakly expressed at sarcolemma of muscle fibers. In congenital MD patients from 2 to 9 years of age, M-PK was clearly expressed at sarcolemma of muscle fibers. M-PK of immature muscle is weakly expressed at sarcolemma. With aging, M-PK is clearly expressed at sarcolemma of muscle from MD patient and normal control.

Adult↗
PubMed1995

MRI of peripheral nerves and pathology of sural nerves in hereditary motor and sensory neuropathy type III.

We investigated two patients with hereditary motor and sensory neuropathy type III, one with Déjérine-Sottas disease and the other with congenital hypomyelination neuropathy based on nerve pathology and MRI of the sciatic nerve. On biopsy of the sural nerve of the patient with Déjérine-Sottas disease, myelin debris, indicating demyelination, was observed in an onion-bulb pattern surrounding myelinated fibres. In the patient with congenital hypomyelination neuropathy, onion bulbs were formed of two parallel layers of basement membrane. There was no evidence of myelin breakdown. On axial T2-weighted MRI, a severely hypertropied sciatic nerve containing multiple rounded lesions, suggesting inflammation or demyelination, was observed in the patient with Déjérine-Sottas disease. In contrast, the sciatic nerve of the patient with congenital hypomyelination neuropathy showed slight hypertrophy without demyelination. MRI of the sciatic nerve may represent a useful tool for characterisation of demyelinating disease and its prognosis.

Adolescent↗
PubMed1995

Somatic cell heterogeneity between DNA extracted from lymphocytes and skeletal muscle in congenital myotonic dystrophy.

Myotonic dystrophy (DM) results from the expansion of an unstable CTG trinucleotide repeat in the 3' untranslated region of mRNA encoding a putative serine/threonine protein kinase. The degree of the CTG repeat amplification in genomic DNAs extracted from lymphocytes correlates with disease severity. We have analyzed the amplification of the CTG repeat of DNAs extracted from skeletal muscles and lymphocytes in five congenital DM patients. The amplification from skeletal muscles showed an increase of about 1.5 kb to 3.5 kb larger than that from lymphocytes in all patients. Furthermore, we have investigated the somatic instability of the CTG repeat in various tissues from a severe congenital DM patient.

Adolescent↗
PubMed1995

Expression of myotonic dystrophy protein kinase in biopsied muscles.

We present expression of myotonic dystrophy protein kinase (DM-PK) on biopsied muscles by immunocytochemistry using antibody against synthetic DM-PK peptide antigen. Immunolocalization of DM-PK was observed in neuromuscular junctions, muscle spindle, and sarcoplasm on both normal and DM muscles. DM-PK expression of sarcoplasm was present in adult normal and DM muscles. In Duchenne and Becker muscular dystrophies, DM-PK was intensively expressed in cytoplasm on immature regenerating fibers. DM-PK is initially produced in cytoplasm of regenerating fibers and migrates toward sarcoplasm with maturity of muscle cell.

Adult↗
PubMed1995

Minimal somatic instability of CTG repeat in congenital myotonic dystrophy.

The molecular basis of myotonic dystrophy was identified as an unstable trinucleotide (CTG) repeat in the 3' untranslated region of an mRNA encoding a member of the protein kinase family. Unstable DNA was analyzed from various tissue samples of a patient with severe congenital myotonic dystrophy. In BamHI- or BglI-digested DNA, a normal band plus differently expanded ones were identified in various tissue samples. These observations demonstrated somatic instability of the repeat in a congenital myotonic dystrophy patient.

Blotting, Southern↗