Biomedical subjects
K Naritomi
Publications and source records attributed to K Naritomi.
Molecular cytogenetic analysis of eight inversion duplications of human chromosome 13q that each contain a neocentromere.
Neocentromeres are fully functional centromeres that have arisen in previously noncentromeric chromosomal locations on rearranged chromosomes. The formation of neocentromeres results in the mitotic stability of chromosomal fragments that do not contain endogenous centromeres and that would normally be lost. Here we describe a unique collection of eight independent patient-derived cell lines, each of which contains a neocentromere on a supernumerary inversion duplication of a portion of human chromosome 13q. Findings in these patients reveal insight into the clinical manifestations associated with polysomy for portions of chromosome 13q. The results of FISH and immunofluorescent analysis of the neocentromeres in these chromosomes confirm the lack of alpha-satellite DNA and the presence of CENtromere proteins (CENP)-C, -E, and hMAD2. The positions of the inversion breakpoints in these chromosomes have been placed onto the physical map of chromosome 13, by means of FISH mapping with cosmid probes. These cell lines define, within chromosome 13q, at least three distinct locations where neocentromeres have formed, with five independent neocentromeres in band 13q32, two in band 13q21, and one in band 13q31. The results of examination of the set of 40 neocentromere-containing chromosomes that have thus far been described, including the 8 neocentromere-containing chromosomes from chromosome 13q that are described in the present study, suggest that chromosome 13q has an increased propensity for neocentromere formation, relative to some other human chromosomes. These neocentromeres will provide the means for testing hypotheses about sequence requirements for human centromere formation.
[Megalencephaly with gigantism, cerebral gigantism (Sotos syndrome)].
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[Goltz syndrome].
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[Dyskeratosis congenita (Zinsser-Cole-Engman syndrome)].
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Two sisters with Toriello-Carey syndrome.
Toriello-Carey syndrome comprises agenesis of the corpus callosum, telecanthus, short palpebral fissures, small nose with anteverted nares, Robin sequence, abnormally shaped ears, cardiac defect, and hypotonia. We describe two Japanese sisters with a Toriello-Carey syndrome whose phenotypes were as severe as reported male cases. The younger sister died suddenly at age 4 months. Our patients with a severe phenotype and possible parental consanguinity suggest autosomal recessive inheritance of Toriello-Carey syndrome.
Hyponatremia-induced metabolic encephalopathy caused by Rathke's cleft cyst: a case report.
Rathke's cleft cysts are sometimes associated with aseptic meningitis or metabolic encephalopathy due to hyponatremia. We treated such a case manifest by lethargy, fever and electroencephalographic abnormalities. A 68-year-old man was admitted to our ward after experiencing general malaise, nausea and vomiting and then high fever and lethargy. On admission, he was drowsy and had nuchal rigidity and Kernig's sign. Physically, he was pale with dry, thickened skin. He had lost 5.0 kg of body weight in the last month. His serum sodium was 115 mEq/l. He had a low serum osmotic pressure (235 mOsmol/l) and a high urine osmotic pressure (520 mOsmol/l). His urine volume was 1200-1900 ml/24 h with a specific gravity of 1008-1015. The urine sodium was 210 mEq/l. He did not have an elevated level of antidiuretic hormone. Electroencephalograms showed periodic delta waves over a background of theta waves. With sodium replacement, the patient become alert and symptom free, and his electroencephalographic findings normalized. However, the serum sodium level did not stabilize, sometimes falling with a recurrence of symptoms. Magnetic resonance imaging clearly delineated a dumbbell-shaped intrasellar and suprasellar cyst. The suprasellar component subsequently shrunk spontaneously and finally disappeared. An endocrinologic evaluation showed panhypopituitarism. The patient was given glucocorticoid and thyroxine replacement therapy, which stabilized his serum sodium level and permanently relieved his symptoms. A transsphenoidal approach was performed. A greenish cyst was punctured, and a yellow fluid was aspirated. The cyst proved to be simple or cubic stratified epithelium, and a diagnosis of Rathke's cleft cyst was made. The patient was discharged in good condition with a continuation of hormonal therapy. Rathke's cleft cyst can cause aseptic meningitis if the cyst ruptures and its contents spill into the subarachnoid space. Metabolic encephalopathy induced by hyponatremia due to salt wasting also can occur if the lesion injures the hypothalamus and pituitary gland.
Brachmann-de Lange syndrome and congenital heart disease.
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Retrospective analysis of clonality and detection of residual disease in myeloid leukemia by FISH on long-term stored bone marrow smears.
BACKGROUND: Fluorescence in situ hybridization (FISH) has allowed the detection of numerical chromosomal aberrations in interphase nuclei on fresh or frozen smears of leukemia. METHODS: To analyze clonality and residual disease in myeloid leukemia retrospectively, we applied FISH to bone marrow smears stored at ambient temperature for up to 9 years. RESULTS: When hybridization efficiency was investigated on stored control smears from patients without hematological malignancy, more than 96% of nuclei showed the expected number of signals using DNA probes specific for chromosome 7, X or Y. In combination with cell morphology, we observed much higher hybridization efficiency in blasts and granulomonocytic cells compared with lymphoid and erythroid cells. On the basis of good hybridization efficiency for old smear specimens, we applied FISH to stored bone marrow smears of myeloid leukemias, in which either loss of chromosome 7 or loss of sex chromosomes had been verified previously by conventional cytogenetics (one patient with chronic myelomonocytic leukemia (CMML) and four with acute myeloid leukemia (AML; three M2 and one M7)). As a result, the loss of chromosome was detected in blasts from all patients and was observed in mature granulocytes, except in M7. In the CMML patient and one AML (M2) patient with t(8;21), lymphoid and erythroid cells also showed the loss of chromosomes, suggesting that it should occur at stem-cell level. A high amount of residual disease was detected in the morphological remission samples in one AML (M2) patient after induction therapy. The patient eventually succumbed to relapse. CONCLUSION: Thus, the present FISH technique is useful to analyze the clinical significance of clonality and the residual disease in myeloid leukemia, retrospectively.
Pneumocephalus associated with ethmoidal sinus osteoma--case report.
A 35-year-old female suffered sudden onset of severe headache upon blowing her nose. No rhinorrhea or signs of meningeal irritation were noted. Computed tomography (CT) with bone windows clearly delineated a bony mass in the right ethmoid sinus, extending into the orbit and intracranially. Conventional CT demonstrated multiple air bubbles in the cisterns and around the mass in the right frontal skull base, suggesting that the mass was associated with entry of the air bubbles into the cranial cavity. T1- and T2-weighted magnetic resonance (MR) imaging showed a low-signal lesion that appeared to be an osteoma but did not show any air bubbles. Through a wide bilateral frontal craniotomy, the cauliflower-like osteoma was found to be protruding intracranially through the skull base and the overlying dura mater. The osteoma was removed, and the dural defect was covered with a fascia graft. Histological examination confirmed that the lesion was an osteoma. The operative procedure resolved the problem of air entry. CT is superior to MR imaging for diagnosing pneumocephalus, by providing a better assessment of bony destruction and better detection of small amounts of intracranial air.
The Cohen syndrome: report of a case.
We report on a sporadic case satisfied with a proposed diagnostic criteria for Cohen syndrome. This 10 year-old Japanese boy had truncal obesity, short stature, mild mental retardation, hypotonia, maxillary hypoplasia, micrognathia, narrow hands and feet, high-arched palate, prominent upper central incisors, high nasal bridge, but no pigmentary retinopathy. Autosomal recessive manner of inheritance was suggested by the pedigree.
Megalocornea-mental retardation syndrome: an additional case report.
We report here on a Japanese male infant with megalocornea-mental retardation (MMR) syndrome. He had megalocornea (corneal diameter: 13 mm) without glaucoma, developmental retardation, hypotonia, frontal bossing, high-arched palate, carp-like mouth, micrognathia, and delayed myelination. He seems to be included in Verloes type of the MMR syndrome.
Agenesis of corpus callosum in three sibs.
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Characterization of marker chromosomes by fish using microdissected probes from old Carnoy-fixed cells: report of two cases.
We reported on two patients with a de novo marker chromosome of which the origins were successfully identified by FISH using microdissected probes. These probes were established by microdissections of extra chromosomal segments from Carnoy-fixed cells stored at -20 degrees C for several years. Using these probes, we could verify partial 1q32 trisomy in a patient with 17p+ as well as partial 16q2 trisomy in another patient with 4p+.
[Clonal analysis by fluorescence in situ hybridization in a patient with de nove acute myeloid leukemia with myelodysplasia].
A 12-year-old girl presenting leukocytosis, anemia and thrombocytopenia was diagnosed as de nove acute myeloid leukemia (AML, M2) with concurrent myelodysplastic features in myeloid and erythroid cells. Her karyotype was defined as 47, XX, +8[20]. Though she was treated successfully with multi-drug chemotherapy, she relapsed after 2 years of remission. A bone marrow transplantation from HLA matched her brother was performed to induce hematological remission which persisted for one year. She again relapsed with AML with myelodysplasia, and an abnormal complex karyotype was newly detected. She eventually died without further chemotherapy. We performed FISH on the patient's stained bone marrow smears using DNA probes for chromosome 8 and Y to analyze the clonality. The results showed that the most of blasts and bone marrow cells except lymphoid cells were of trisomy 8 at onset, while in the 1st remission, trisomy 8 clone was slightly detected only in monocytes. At 1st and 2nd relapse, trisomy 8 clone was detected again in most of myeloid cells. Thus, in this case, it was considered that underlying stem cell disorder with trisomy 8 during the entire disease course contributed to leukemogenesis.
Japanese cases of type 1 thanatophoric dysplasia exclusively carry a C to T transition at nucleotide 742 of the fibroblast growth factor receptor 3 gene.
Type I thanatophoric dysplasia (TD) is typically a lethal neonatal dwarfism, but a limited number of cases of type I TD cases survive more than one year, suggesting genetic heterogeneity. In this study, we analyzed the fibroblast growth factor receptor 3 (FGFR3) gene in 5 Japanese cases of type I TD with clinical symptoms ranging from lethal to long-survival. In every case, nucleotide sequence analysis of cDNA revealed a C to T transition at nucleotide 742 (C742T) in one allele of the FGFR3 gene, suggesting that type I TD is a rather homogeneous genetic condition, irrespective of clinical course. No association was found between C742T and C882T, although both nucleotides changes were from CpG dinucleotide in a near location.