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Biomedical subjects

T Kajii

Publications and source records attributed to T Kajii.

At least 19 recordsLinked to original sources
PubMed2001

Two cases of mosaic RhD blood-group phenotypes and paternal isodisomy for chromosome 1.

We encountered a 22-year-old man (case 1) and a 23-year-old woman (case 2), both unrelated and healthy. They were mosaic for the Rh blood group phenotype: one erythrocyte population was D-positive and the other was D-negative. Flow cytometric analysis of density profile of RhD antigen in their erythrocytes, and cytogenetic analysis including in situ hybridization using an RHD/RHCE-containing PAC clone, excluded a deletion of the RHD/RHCE gene complex, but suggested the presence of cells with uniparental disomy for chromosome 1 (UPD1). Microsatellite marker analysis was performed in both probands and their family members. In case 1, the analysis with markers spanning the chromosome 1 revealed both maternal and paternal alleles in his peripheral blood leukocytes (PBL), Epstein-Barr virus-transformed lymphoblastoid cells (EBL), and buccal mucosal cells. However, only paternal alleles were detected in all of 50 individual pieces of his hair or hair-roots and all of five monoclonal cell lines cloned from his established EBL. There was no direct evidence of heterozygous, biparental alleles in these two tissues. The presence of maternal isodisomy 1 was not absolutely ruled out in other tissues examined in case 1. Similar results were obtained in case 2, showing biparental, disomic patterns in her PBL and in 15 of 20 pieces of her hair roots, and showing monoallelic patterns in the remaining five pieces of hair roots. Analysis with markers for other autosomes confirmed their biparental inheritance. These findings indicated that both cases had at least two cell populations, one population having paternal UPD1 (isodisomy 1), and another heterozygous, biparental disomy 1. We emphasize that isodisomy for chromosome 1 is not infrequent and may cause unusual RhD phenotype, as seen in cases we described.

Adult↗
PubMed2001

Cancer-prone syndrome of mosaic variegated aneuploidy and total premature chromatid separation: report of five infants.

Five infants (two girls and three boys) from four families all had severe pre- and postnatal growth retardation, profound developmental delay, microcephaly, hypoplasia of the brain with Dandy-Walker complex or other posterior fossa malformations, and developed uncontrollable clonic seizures. Four infants developed Wilms tumors, and one showed cystic lesions in bilateral kidneys. All five infants showed variegated mosaic aneuploidy in cultured lymphocytes. In two infants whose chromosomes were prepared by us, 48.5%-83.2% lymphocytes showed total premature chromatid separation (PCS). Their parents had 3.5%-41.7% of their lymphocytes in total PCS. The remaining three infants and their parents, whose chromosomes were prepared at outside laboratories, tended to show lower frequencies of total PCS. Another five infants reported with the disorder were reviewed together with the five infants we described. Together, their clinical and cytogenetic manifestations were similar enough to suggest a syndrome. Seven of the 10 infants developed proven or probable Wilms tumors. The age at diagnosis of the tumors was younger than usual at 2-16 months. The tumors were bilateral in four infants and unilateral in three infants, and cystic changes were present in six infants. Two infants developed botryoid rhabdomyosarcoma. The carriers of the syndrome are thus liable to tumorigenesis. The possible role of mitotic checkpoint defects, proven in two infants with the syndrome (Matsuura et al. [2000: Am J Hum Genet 69:483-486]), was discussed in connection with tumor development and progression.

Abnormalities, Multiple↗
PubMed2001

Presence of third molar germs in orthodontic patients in Japan.

The purpose of this investigation was to evaluate the existence of third molar germs in orthodontic patients in Japan and to examine the relationship between the existence of third molars and sagittal maxillomandibular jaw relationships. The subjects comprised 306 patients from the orthodontic clinic of Hokkaido University Dental Hospital who were younger than 15 years. The subjects were divided into 2 groups: 1 group included 144 patients who were born between 1966 and 1969 (60s group), and the other group included 162 patients who were born between 1980 and 1987 (80s group). Assessments were made from panoramic radiographs and lateral cephalograms. The following results were obtained: (1) all 4 third molar germs were present in 77% of subjects, (2) mandibular third molars were present significantly more often than maxillary third molars, and (3) the percentage of skeletal Class III subjects who had all 4 third molars was lower than that of skeletal Class II subjects. The chi(2) test was used to determine statistical significance in differences.

Adolescent↗
PubMed2000

Chromosomal instability syndrome of total premature chromatid separation with mosaic variegated aneuploidy is defective in mitotic-spindle checkpoint.

Skin fibroblast cells from two unrelated male infants with a chromosome-instability disorder were analyzed for their response to colcemid-induced mitotic-spindle checkpoint. The infants both had severe growth and developmental retardation, microcephaly, and Dandy-Walker anomaly; developed Wilms tumor; and one died at age 5 mo, the other at age 3 years. Their metaphases had total premature chromatid separation (total PCS) and mosaic variegated aneuploidy. Mitotic-index analysis of their cells showed the absence of mitotic block after the treatment with colcemid, a mitotic-spindle inhibitor. Bromodeoxyuridine-incorporation measurement and microscopic analysis indicated that cells treated with colcemid entered G1 and S phases without sister-chromatid segregation and cytokinesis. Preparations of short-term colcemid-treated cells contained those cells with chromosomes in total PCS and all or clusters of them encapsulated by nuclear membranes. Cell-cycle studies demonstrated the accumulation of cells with a DNA content of 8C. These findings indicate that the infants' cells were insensitive to the colcemid-induced mitotic-spindle checkpoint.

Abnormalities, Multiple↗
PubMed1999

Long-term effects of prostaglandin E2 on the mineralization of a clonal osteoblastic cell line (MC3T3-E1).

Prostaglandin (PG) E2 is thought to be a mediator of the effect of mechanical stress on bone formation, but its effects on osteoblasts have not yet been fully described. Here, the effects of the continuous application of PGE2 and indomethacin, an inhibitor of prostaglandin G/H synthase (cyclo-oxygenase), on the proliferation, differentiation and mineralization of a clonal osteoblastic cell line, MC3T3-E1, were investigated. The cells were cultured in media with either a high (1 microg/ml) or a low (1 ng/ml) concentration of PGE2, with indomethacin (1 microg/ml) and, as a control, with neither agent. The effects of PGE2 and indomethacin were assessed quantitatively. Indomethacin and a high concentration of PGE2 increased the total protein compared to the control and low-PGE2 cultures. 7 days after confluence, alkaline phosphatase (ALP) activity within the cells and extracellular matrices increased. This increase was highest with indomethacin and lowest with a high concentration of PGE2. ALP activity also increased in the medium, but only 21 days after confluence; the effects of the agents were similar to those on the cells and matrices. The accumulation of calcium, inorganic phosphate and hydroxyproline was highest with indomethacin. PGE2 production was at its maximum when the cells were at confluence and was inhibited by indomethacin. Specific [3H]PGE2 binding to the microsomal fraction of the cell was also measured to examine the expression of the PGE2 receptor. The amount of [3H]PGE2 binding per mg of protein was highest at confluence, then decreased and again increased in the mineralizing stage. These results suggest that indomethacin increases ALP activity and the accumulation of mineralized tissue in MC3T3-E1 cells, presumably by inhibiting the production of PGE2. PGE2 could signal the suppression of mineralization as early as confluence.

3T3 Cells↗
PubMed1998

Mosaic variegated aneuploidy with multiple congenital abnormalities: homozygosity for total premature chromatid separation trait.

Separation of chromatids of all mitotic chromosomes, here called total premature chromatid separation (total PCS), was observed in 67 to 87.5% of repeated cultures of peripheral blood lymphocytes from two unrelated infants. Also noted was a variety of mosaic aneuploidies, especially trisomies, double trisomies, and monosomies, to be called mosaic variegated aneuploidy. The infants both showed severe pre- and postnatal growth retardation, profound developmental retardation, uncontrollable seizures, severe microcephaly, hypoplasia of the brain, Dandy-Walker anomaly, abnormal facial appearance, and bilateral cataract. Patient 1, a girl, in addition had a cleft palate, multiple renal cysts, and Wilms tumor of the left kidney. Whereas patient 2, a boy, had ambiguous external genitalia. They both died within 2 years of age. In the two families of the infants, their parents and three other members showed 2.5 to 47% lymphocytes with total PCS but without mosaic variegated aneuploidy or phenotypic abnormalities. Another 10 relatives studied showed 0 to 1% cells with total PCS and so were judged negative for the total PCS trait. It was deduced that the total PCS trait in the two families was transmitted in an autosomal-dominant fashion, and the two affected infants were homozygous for the trait.

Abnormalities, Multiple↗
PubMed1997

A recurrent translocation, t(16;21)(q24;q22), associated with acute myelogenous leukemia: identification by fluorescence in situ hybridization.

Chromosome fluorescence in situ hybridization (FISH) analyses were performed on bone marrow cells in 3 adult patients with MDS or AML with a (16;21)(q24;q22) translocation. FISH analyses with AML1 probes at 21q22 proved in all 3 patients splitting of the AML1 gene at a region spanning exons 5 and 6 and the translocation of its 5' segment to distal 16q. Chromosome painting FISH analysis in patient 1 proved the translocation of the distal 21q segment to 16q, but it failed to prove the presumed translocation of the distal 16q segment to 21q, most likely because of its small size.

Adult↗
PubMed1995

Interstitial deletion of 8p: report of two patients and review of the literature.

Two female infants with de novo interstitial deletions of 8p were studied. One with a deletion from p11.21 to p11.23, and the other patient with a deletion from p11.23 to p21.3 had several clinical manifestations of the terminal 8p- syndrome. Band 8p11.23 was deleted in both patients. The clinical manifestations common to both patients included low birthweight, growth deficiency, congenital heart disease, mental retardation, dolichocephaly, low-set, malformed ears, high-arched palate, thin lips and micrognathia. Since these features may occur in most patients with chromosomal imbalance, and the terminal 8p- syndrome has hitherto been assumed to result from terminal deletions of 8p, ranging from p21.3 to p23, it is likely that these features are simply related to the chromosomal imbalance rather than to band specific imbalance of 8p11.23. The present study suggests that two different types of deletion, interstitial and terminal, are associated with still poorly defined, rather non-specific clinical features.

Adult↗
PubMed1994

Congenital heart defects in Aarskog syndrome.

We report on 10 Japanese individuals from 3 families affected with Aarskog syndrome. Pulmonary stenosis and ventricular septal defect with spontaneous closure were detected respectively, in 2 of them as an uncommon finding. A review documented 169 non-Japanese cases (2 with congenital heart defects), while of 30 Japanese individuals reported till now, 4 (including ours) had cardiac anomalies. We propose that this combination is not coincidental and that in all cases of Aarskog syndrome a cardiac evaluation is indicated.

Abnormalities, Multiple↗
PubMed1994

Occipital horn syndrome: report of a patient and review of the literature.

We report an 18-year-old boy with occipital horn syndrome and we review the 20 cases previously published with this syndrome. The distinctive features common to all patients were unusual facial appearance, skeletal abnormalities, chronic diarrhea and genitourinary abnormalities. The skeletal abnormalities included occipital horns, short, broad clavicles, deformed radii, ulnae, and humeri, narrowing of the rib cage, undercalcified long bones with thin cortical walls and coxa valga. Occipital horn syndrome is inherited in an X-linked recessive fashion. Our analysis indicates that occipital horn syndrome is associated with a recognizable characteristic phenotype.

Adolescent↗
PubMed1993

Premature aging and immunodeficiency: Mulvihill-Smith syndrome?

We report on a 30-year-old woman with premature aging, immunodeficiency, and other abnormalities. She had many manifestations of the Mulvihill-Smith syndrome, a disorder that has been described in 4 sporadic individuals, ranging in age from 4 to 17 years. The common manifestations include short stature, microcephaly, a senile face with an underdeveloped lower half, diminished facial subcutaneous fat, multiple pigmented nevi, sensorineural hearing loss, and a low IgG level. Our patient also had severe mental retardation, brachydactyly, severe T cell dysfunction, and suffered from severe verruca vulgaris and a chronic, active Epstein-Barr virus infection. The fact that her parents were first cousins suggests autosomal recessive inheritance of her disorder. Two alternative possibilities were considered: the disorder in the patient represents the Mulvihill-Smith syndrome with immune deficiency as a sign of its advanced stage, or a hitherto undescribed syndrome.

Adult↗
PubMed1993

Two Japanese cases with microcephalic primordial dwarfism: classical Seckel syndrome and osteodysplastic primordial dwarfism type II.

A male infant with "classical" Seckel syndrome and a girl with osteodysplastic primordial dwarfism type II are described. The boy with classical Seckel syndrome had severe brain dysplasia, a finding hitherto unreported in patients with this syndrome. The patient with osteodysplastic dwarfism type II had skeletal abnormalities including lumbar scoliosis, a small and high pelvis, metaphyseal flaring of the distal radii and ulnae, V-shaped metaphyseal flaring of the distal femorae, and short metacarpals and phalanges. The mother of this girl was short, microcephalic, and had disproportionately short forearms and legs. In view of this, dominant inheritance of the disease was suggested.

Abnormalities, Multiple↗
PubMed1993

Tissue-specific and developmentally regulated expression of the genes encoding adenylate kinase isozymes.

Adenylate kinase (AK) is known to play an important role in homeostasis of adenine nucleotide metabolism. We isolated cDNAs for rat AK isozymes (AK1, AK2, and AK3), determined their mRNAs in rat tissues by Northern blot analysis, and measured the isozyme activities. Tissue-dependent activities of AK1 and AK2 paralleled the contents of mRNAs. Tissues with high AK1 levels showed low AK2 levels and vice versa, suggesting that tissue-specific expressions of the AK1 and AK2 genes are inversely regulated. AK3 mRNA was detected in most tissues examined, suggesting that AK3 gene expression is constitutive. We further examined developmental changes in mRNAs and enzyme activities of AK isozymes in rat skeletal muscle and liver. In the skeletal muscle, AK1 and AK3 activities started to increase at around the weaning period. AK1 mRNA accumulated at the prenatal stage and further increased during development, while AK3 mRNA was at high levels during the fetal stage and remained fairly constant during development. In the liver, AK2 and AK3 activities started to increase after birth and were further elevated during growth, whereas their mRNAs were present at relatively high levels throughout development. The physiological meanings of the tissue-specific expression of the AK isozyme genes are discussed.

Adenylate Kinase↗