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Biomedical subjects

M Higurashi

Publications and source records attributed to M Higurashi.

At least 37 records · Page 2Linked to original sources
PubMed1993

The development of sleep-wakefulness rhythm in normal infants and young children.

The development of circadian sleep-wakefulness rhythm was investigated by a longitudinal study of two normal newborns for two and a half years and by a transversal study of 182 normal infants and young children living in three different areas of Japan. The circadian rhythm became established before 4 months of age, and daytime sleep became concentrated within two time periods from 7 months of age, and then within a single peak from 14 months of age. The time period 00:00-04:00 developed into the "absolute sleep period" from 3 months of age, and the "absolute wakefulness period" appeared first in the time period 08:00-11:00 from 14 months of age, and then in the time period 16:00-21:00 from one and a half years of age. Establishment of circadian rhythm as indicated by the numbers of sleep epochs in daytime and in nighttime, and the longest continuous sleep or wakefulness periods reflect the development of the nervous system and were influenced by the change of light-dark in the environment. These parameters showed critical ages, but not sexual or regional differences. However, regional differences were found in the times of waking up in morning and falling asleep at night. This indicated the phase of the circadian rhythm was also influenced by natural and social environmental factors.

Aging↗
PubMed1993

[XYY syndrome].

Explore the source record for details and available documents.

Humans↗
PubMed1993

[Attitudes toward handicapped children--a study comparing parents of handicapped children and others, in the case of Down syndrome].

The physically handicapped have received increasing attention in recent years. Since 1981, the International Year of Handicapped Persons, a number of administrative measures have been passed and the rights of handicapped have been recognized. However some problems still remain. In this study, conducted in 1990, the knowledge people have about congenital defects and their thinking regarding the social system for the handicapped were examined. A similar survey of parents of children with congenital defects was conducted to understand problems they encountered in the medical care and education of their child. Eighty-four parents of Down Syndrome children (DS) and 118 controls including housewives, female office workers, and students were surveyed. Results showed that 44% of mothers of DS wanted their husbands to participate more intensively in the medical care and education of their child. A slight gap in knowledge between the parents and the controls was seen. Of the controls, 12% asserted that the relationship of the handicapped and the non-handicapped should be equal. However, some of controls expressed that if they had a child with congenital defects, they had no confidence that they could bring up the child in this society.

Adolescent↗
PubMed1992

The effect of aging on cell-cycle kinetics and X-ray-induced chromosome aberrations in cultured lymphocytes from patients with Down syndrome.

To evaluate the effects of aging on cytogenetic characteristics of lymphocytes from Down syndrome (DS), cell-cycle kinetics after PHA stimulation and chromosome-type aberration frequencies after X-ray exposure were investigated in vitro in the lymphocytes derived from 4 (or 3 for X-ray treatment) age groups of DS patients and age-matched controls. The results clearly showed higher mitotic and proliferation index levels in younger groups compared to older groups at the various culture intervals, whether the lymphocytes were from the DS patients or controls. The age-related changes of the proliferation index were mainly attributed to a delayed response to PHA as age increased. The changes of PHA responses seemed to be particularly marked during adolescence. Nonetheless, no significant differences were observed between the DS patients and age-matched controls for each age group. In all age groups, frequencies of both chromosome-type exchanges and deletions were elevated in the DS patients by about 1.3 times in comparison with the controls. The magnitude of radiosensitivity, however, seemed to decrease slightly in the 40-49-year group. To our knowledge, the present study is the first report in the literature to deal with the effect of aging on the greater radiosensitivity of DS lymphocytes.

Adolescent↗
PubMed1992

Retrocaval ureter with recurrent pyelonephritis.

A case of retrocaval ureter with recurrent pyelonephritis is presented with discussion of these clinical entities. An excretory urogram and retrograde ureterogram disclosed pronounced hydronephrosis as well as a dilated proximal part and reversed J-shaped appearance of the right ureter. The compressed retrocaval portion of the ureter was resected and an end-to-end anastomosis was performed anterior to the vena cava. Due to the progressive kidney damage leading to severe hydronephrosis, a rapid radiological diagnosis should be made to replace the retropositioned ureter.

Adult↗
PubMed1991

The combination of DNA methylation and H1 histone binding inhibits the action of a restriction nuclease on plasmid DNA.

To investigate the potentials of DNA methylation and H1 histone in regulating the action of DNA binding proteins, well ordered complexes were formed by slow salt gradient dialysis of mixtures of H1 histone with either methylated or nonmethylated DNA. The sites methylated in the plasmids were CCGG. Methylation of cytosine in this site protects the DNA against HpaII endonuclease but not against MspI. However, when the methylated DNA was complexed to H1, it was protected against MspI. The protection was only effective for a subset of the MspI restriction sites. The protection of DNA afforded by the combination of H1 binding and DNA methylation did not apply to EcoRI, PstI, or BamHI sites and so did not seem to be due to aggregation of the DNA by H1 histone. Gel retardation assays indicated that the affinity of H1 for methylated DNA was not detectably different from its affinity for nonmethylated DNA. Probably methylated DNA when bound to H1 is in a conformation that is resistant to MspI endonuclease. Such conformational changes induced by DNA methylation and H1 binding might affect the action of other DNA binding proteins, perhaps in chromatin as well as in H1.DNA complexes.

Animals↗
PubMed1991

Heterogeneity of serum and amniotic fluid prolactin in humans.

The molecular heterogeneity of PRL was studied in serum and amniotic fluid using immunoperoxidase electrophoresis. In the amniotic fluid, larger molecular variants (greater than 117 kD), small PRL (20 and 23 kD) and cleaved PRL were present in the nonreduced condition. Newly, three mercaptoethanol (MCE)-resistant forms (76, 64 and 53 kD), and 25- and 23-kD forms appeared after treatment with MCE. Two variants, 64 and 23 kD, did not bind to concanavalin A (Con A), indicating a simple peptide without sugars. Other glycosylated forms, 76, 53 and 25 kD, bound to Con A. In maternal serum, the same components as those in the amniotic fluid were seen, except for a scanty amount of 23 kD and a newly appearing glycosylated variant of 28 kD in the reduced condition. This 23-kD form also appeared with the administration of TRH in women.

Amniotic Fluid↗
PubMed1991

The development of sleep and wakefulness cycle in early infancy and its relationship to feeding habit.

The purpose of this study was to evaluate the relationship between sleep and wakefulness patterns to feeding habits in early infancy. The population consisted of 33 neurologically normal infants studied during their first 4 months of life. The number of 30-min epochs with sleep (sleep epoch) were counted in each 4-hr period in a day and evaluated over time. The effects of feeding on sleep and wakefulness were examined by analyzing the rates of sleep epoch after feeding in each time period. The rates of sleep epochs in each time period showed specific patterns each week. From 2 weeks of age, sleep epochs appeared most frequently in time periods 0:00-4:00 and 4:00-8:00 (p less than 0.01). These periods also had significantly high rates of sleep epochs after feeding by week 2. From week 6 both the number of sleep epochs and the rate of sleep epochs after feeding in time periods from 8:00 to 20:00 tended to decrease. These results suggest that the development of the circadian oscillation is set as a sleep epoch first during the time period of 0:00 to 8:00. In addition, feeding alone seemed to have no role as a time cue in the first 4 months of life.

Circadian Rhythm↗
PubMed1990

Livebirth prevalence and follow-up of malformation syndromes in 27,472 newborns.

The results of a survey of the birth prevalence of congenital anomalies among 27,472 consecutive newborn babies at a large maternity hospital in Tokyo are reported. There were 29 cases with trisomy-21; 5 cases with trisomy-13 syndrome; 5 with trisomy-18 syndrome; 2 with cri-du-chat syndrome; and one each with partial monosomy 4p, partial trisomy 5p, partial trisomy 6p, partial trisomy 9p, partial trisomy 9q, partial monosomy 10p, and partial monosomy 13q. Single cases of the following were observed: the Hallermann-Streiff syndrome, the Treacher-Collins syndrome, achondroplasia, arthrogryposis, the Beckwith-Wiedemann syndrome, the asplenia syndrome, the Klippel-Trenaunay-Weber syndrome, the Marfan syndrome, the Carpenter syndrome, the Goldenhar syndrome, and the Pierre Robin syndrome. The results of follow-ups to determine the life-prognosis of each patient with an autosomal aberration are reported.

Chromosome Aberrations↗
PubMed1989

Ullrich-Turner syndrome and anorexia nervosa.

We report on a 6-year-old girl with Ullrich-Turner syndrome and anorexia nervosa. The diagnosis was made at 6 years and she became anorectic at 14 years. She had been treated with low doses of estrogen just before the onset of anorexia. In spite of remarkable decrease in food intake, her body weight was in the normal range compared to standard weight. Rohrer indices were also normal, probably due to abnormal habitus in individuals with the syndrome. The pathogenetic relationship between this disorder and the hormone treatment in the onset of anorexia nervosa is discussed.

Anorexia Nervosa↗
PubMed1989

Mitomycin-C-induced sister-chromatid exchanges and cell-cycle kinetics in lymphocytes from patients with Klinefelter syndrome.

The chromosomal sensitivity to mitomycin-C (MMC) and cell-cycle kinetics in cells from patients with Klinefelter syndrome, a sex chromosomal disorder giving a high risk of malignant tumor, were studied by techniques of sister-chromatid exchanges (SCEs). The frequencies of MMC-induced SCEs increased in proportion to the increase in MMC concentration in both patient and normal control cells. At low levels of MMC there were no significant differences in SCE frequencies between the patient and normal control cells, but at MMC concentrations of 3 X 10(-8) M (p less than 0.05) and 1 X 10(-7) M (p less than 0.01), significant increases in the frequency of MMC-induced SCEs were observed in cells from patients compared to cells from normal controls. Although the analysis of cell-cycle kinetics both after various culture times and after treatment with MMC revealed that there were no significant differences between the patient and normal control cells, patients with Klinefelter syndrome showed a tendency to cell-cycle delays after treatment with MMC in comparison with normal controls.

Cell Cycle↗
PubMed1989

Effects of high-rise living on physical and mental development of children.

Effects of high-rise living on infants' development were investigated in 1987-1988 in a high-rise residential area in Tokyo, using questionnaires on the daily behaviors of a total of 1,045 infants, completed by mothers and kindergarten teachers. Infants of high-rise living showed a delayed independence in fundamental daily customs compared with those of low-rise living. This could be ascribed to an over-attachment of mothers of high-rise living with their infants resulting from a reduced number of outings.

Activities of Daily Living↗
PubMed1987

Synthesis and degradation of H1 histone subtypes in mouse lymphoma L5178Y cells.

H1 histone of mouse lymphoma L5178Y was fractionated into five subtypes, I-V, by Bio-Rex 70 column chromatography. The rates of synthesis of subtypes III and V were higher than those of I, II, and IV, as determined by the measurement of [3H]lysine incorporation. The degradation of the subtype was estimated assuming first order kinetics; subtypes III and V had half-lives of 18 h and 25 h, respectively, and the three other subtypes all had half-lives of 63 h. The syntheses of these subtypes during the cell cycle were examined using synchronized cultures. The syntheses of subtypes I, II, and IV started at the beginning of S phase, whereas those of III and V started in mid-S phase. The syntheses of III and V were at least 1.5-2 times more rapid than those of I, II, and IV, and their active synthesis was accompanied by their rapid degradation. The five subtypes of H1 were further characterized in relation to phosphorylation. Each showed characteristic differences in its synthetic pattern or phosphorylation, and we concluded that each H1 subtype has its own specific function at least in the process of replication of chromatin.

Animals↗