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Biomedical subjects

A Morishima

Publications and source records attributed to A Morishima.

At least 19 recordsLinked to original sources
PubMed2000

Helicases and aging.

Studying monogenic hereditary disorders that manifest age-related phenotypes in cells, tissues, and the total organism would be helpful for clarifying the mechanisms of aging. In this context, seven human disorders that manifest age-related phenotypes have been found to be caused by aberrations of five proteins with seven helicase motifs conserved in most of the helicases. These disorders are xeroderma pigmentosum, Cockayne syndrome, trichothiodystrophy, Bloom syndrome, Werner syndrome, X-linked alpha-thalassemia/mental retardation syndrome, and Juberg-Marsidi syndrome. A decline of probably pleiotropic and fundamental function of helicases in these disorders is, therefore, implied to underlie not only the various age-related phenotypes of the disorders but also the pleiotropic and universal nature of ordinary aging. Consistent with this implication, studies of these seven disorders suggest that their various age-related phenotypes are caused by aberrations in multiple processes, especially transcription. Furthermore, a few studies imply some association between aberration of the helicases and phenotypes in ordinary aging.

Aging↗
PubMed1999

Hyperkalemia probably reverses the antiarrhythmic effects of amiodarone: a case report.

Sustained monomorphic ventricular tachycardia (VT) developed in a 58-year-old man with acute myocardial infarction and end-stage renal disease. Amiodarone was effective in preventing VT recurrence. Sustained VT was not induced during an electrophysiologic study. However, VT recurred during accidental hyperkalemia, which was caused by the change of dialysis therapy from peritoneal dialysis to hemodialysis. VT subsided with correction of hyperkalemia. Thereafter, VT did not recur as long as the serum potassium concentration was kept within the normal range. Several months later, the patient died suddenly because poor dietary compliance resulted in an increase in his potassium concentration. This case suggests that hyperkalemia may reverse the potent antiarrhythmic effects of amiodarone.

Acute Kidney Injury↗
PubMed1998

Identification of preferred binding sites of a light-inducible DNA-binding factor (MNF1) within 5'-upstream sequence of C4-type phosphoenolpyruvate carboxylase gene in maize.

MNF1 is a factor which specifically binds to a 318 bp fragment (-1012 to -695) in the 5'-flanking region of the C4-type phosphoenolpyruvate carboxylase gene in Zea mays (Yanagisawa et al., Mol Gen Genet 224 (1990) 325-332). The most preferred binding site of MNF1 determined by a 2 bp mutation-scanning assay was an octamer sequence, GTGCCCTT, which is located within the repeated sequences (RS1; -886 to -849, -846 to -807). Furthermore, a PCR-mediated selection-amplification assay identified both the octamer sequence, GTGCCC(A/T)(A/T), and an additional sequence. CC(G/A)CCC, the latter of which was similar to the Sp1 sites in vertebrates. Specific binding of MNF1 to each of the supposed binding sites was confirmed with double-stranded monomers as probes. Considering native molecular mass of MNF1 (ca. 500 kDa), a protein complex is expected. In addition, MNF1 is anticipated to have two distinct DNA-binding proteins since the MNF1 binding to CCGCCC element was 1,10-phenanthroline-dependent whereas the MNF1 binding to the octamer was independent. Wide distribution of the MNF1 binding sequences within the 1 kb promoter region accounts for broad interactions of MNF1. Moreover, specific DNA binding due to MNF1, which was not observed in the nuclear extract derived from germinated and cultivated plants in darkness, appeared after a white-light pulse. This finding suggests the involvement of the protein complex in the light-dependent transcriptional control in the gene expression.

Base Sequence↗
PubMed1998

Pediatric endocrinology update: an overview. The essential roles of estrogens in pubertal growth, epiphyseal fusion and bone turnover: lessons from mutations in the genes for aromatase and the estrogen receptor.

The goals of this presentation are to review the essential roles of aromatase, estrogens and the estrogen receptor in pubertal growth. Estrogen deficiency due to mutations in the aromatase gene (CYP19) and estrogen resistance due to disruptive mutations in the estrogen receptor gene have no effect on normal male sexual maturation in puberty. However, they lead to absence of the pubertal growth spurt, delayed bone maturation, unfused epiphyses, continued growth into adulthood and very tall adult stature in both sexes. Gonadotropin and androgen levels are elevated in patients with either estrogen deficiency (aromatase deficiency) or estrogen resistance (estrogen receptor mutation). Glucose intolerance, hyperinsulinemia and lipid abnormalities are also present. Skeletal integrity is compromised. Increased bone turnover, reduced bone mineral density and osteoporosis develop in both sexes. Sexual orientation is appropriate in males and females. In females, aromatase deficiency in the ovary causes pubertal virilization and multicystic ovaries because of elevated gonadotropins and androgens. Simultaneously, secondary sexual maturation fails to occur. Placental aromatase deficiency results in virilization of the mother and her female fetus because of the accumulation of potent androgens which are not converted to estrogens. The male fetus has normal genitalia. In conclusion, estrogens are essential for normal female secondary sexual maturation, bone maturation, epiphyseal fusion, pubertal growth spurt and achievement of normal bone mineral mass. Estrogens also influence insulin sensitivity and lipid homeostasis. However, estrogens do not appear to be essential for fetal survival, placental growth, or female sexual differentiation.

Adult↗
PubMed1998

[A case of mild-type myotonic dystrophy with dementia and severe arteriosclerosis obliterans].

A 70-year-old man, with mild-type myotonic dystrophy (MyD) diagnosed by molecular genetic analysis when he was 68 years old, complained of worsening intermittent claudication during the past 2 years. Doppler examination revealed severe stenosis and obstruction in his leg arteries, which we diagnosed as arteriosclerosis obliterans (ASO). We then found him to be suffering from dementia, which was confirmed by dementia scale tests (Mini Mental State, 20/30; Hasegawas' Dementia Scale-Revision, 15/30). Even in mild-type MyD, as MyD is one of the progeria syndromes, the abnormal genes of MyD may accelerate the aging processes.

Aged↗
PubMed1997

Molecular and epidemiological studies of Werner syndrome in the Japanese population.

Werner syndrome (WS) is an autosomal recessive genetic disease characterized by many age-related features. The gene responsible for WS (WRN) has been isolated and contains a helicase domain, but its function is unknown. Six different mutations throughout the WRN gene have been reported in the Japanese population. We have studied whether patients with a specific mutation exhibit distinct phenotypes from others. Fourteen patients with different mutations showed almost the same signs and symptoms and, therefore, the C terminal part of the product appears to be crucial for its functions, although other parts may be important as well. Haplotype analyses using 13 microsatellites covering the 2.8-3.0 cM WRN region showed that two out of six different mutations had founder chromosomes. These two founder chromosomes may be evenly distributed throughout the western part of Japan, suggesting that these mutations go back to a time earlier than 1400 years ago.

Chromosome Mapping↗
PubMed1996

Gender change from female to male in classical congenital adrenal hyperplasia.

The psychoendocrinology of the development of normal gender identity and its variations is poorly understood. Studies of gender development in individuals born with endocrinologically well-characterized intersex conditions are heuristically valuable for the disaggregation of factors that are acting in concert during normal development. Four 46,XX individuals with classical congenital adrenal hyperplasia (CAH) and atypical gender identity entered a comprehensive research protocol including systematic interviews and self-report inventories on gender role behavior and identity, sexual history, and psychiatric history. Some of the data on gender variables were compared to data from 12 CAH women with the salt-wasting variant (CAH-SW) with female gender identity. The four patients (ages 28, 35, 38, and 30 years) represented three different subtypes of classical early-onset CAH: 21-OH deficiency, simple virilizing (CAH-SV); 21-OH deficiency, salt-wasting (CAH-SW); and 11-beta-OH deficiency. Their medical histories were characterized by delay beyond infancy or lack of surgical feminization of the external genitalia and progressive virilization with inconsistent or absent glucocorticoid replacement therapy. Although three patients had undergone one or more genital surgeries, all had retained at least some orgasmic capacity. In regard to childhood gender-role behavior, the four gender-change patients tended to be more masculine or less feminine than (behaviorally masculinized) CAH-SW controls. All patients were sexually attracted to females only. The process of gender change was gradual and extended well into adulthood. The most plausible factors contributing to cross-gender identity development in these patients appeared to be neither a particular genotype or endocrinotype nor a sex-typing bias on the part of the parents but a combination of a gender-atypical behavioral self-image, a gender-atypical body image, and the development of erotic attraction to women. Implications for psychosocial management are also discussed.

Adrenal Hyperplasia, Congenital↗
PubMed1995

Aromatase deficiency in male and female siblings caused by a novel mutation and the physiological role of estrogens.

The aromatase enzyme complex catalyzes the conversion of androgens to estrogens in a wide variety of tissues, including the ovary, testis, placenta, brain, and adipose tissue. Only a single human gene encoding aromatase P450 (CYP19) has been isolated; tissue-specific regulation is controlled in part by alternative promoters in a tissue-specific manner. We report a novel mutation in the CYP19 gene in a sister and brother. The 28-yr-old XX proband, followed since infancy, exhibited the cardinal features of the aromatase deficiency syndrome as recently defined. She had nonadrenal female pseudohermaphrodism at birth and underwent repair of the external genitalia, including a clitorectomy. At the age of puberty, she developed progressive signs of virilization, pubertal failure with no signs of estrogen action, hypergonadotropic hypogonadism, polycystic ovaries on pelvic sonography, and tall stature. The basal concentrations of plasma testosterone, androstenedione, and 17-hydroxyprogesterone were elevated, whereas plasma estradiol was low. Cyst fluid from the polycystic ovaries had a strikingly abnormal ratio of androstenedione and testosterone to estradiol and estrone. Hormone replacement therapy led to breast development, menses, resolution of ovarian cysts, and suppression of the elevated FSH and LH values. Her adult height is 177.6 cm (+2.5 SD). Her only sibling, an XY male, was studied at 24 yr of age. During both pregnancies, the mother exhibited signs of progressive virilization that regressed postpartum. The height of the brother was 204 cm (+3.7 SD) with eunuchoid skeletal proportions, and the weight was 135.1 kg (+2.1 SD). He was sexually fully mature and had macroorchidism. The plasma concentrations of testosterone (2015 ng/dL), 5 alpha-dihydrotestosterone (125 ng/dL), and androstenedione (335 ng/dL) were elevated; estradiol and estrone levels were less than 7 pg/mL. Plasma FSH and LH concentrations were more than 3 times the mean value. Plasma PRL was low; serum insulin-like growth factor I and GH-binding protein were normal. The bone age was 14 yr at a chronological age of 24 3/12 yr. Striking osteopenia was noted at the wrist. Bone mineral densitometric indexes of the lumbar spine (cancellous bone) and distal radius (cortical bone) were consistent with osteoporosis; the distal radius was -4.7 SD below the mean value for age- and sex-matched normal men; indexes of bone turnover were increased. Hyperinsulinemia, increased serum total and low density lipoprotein cholesterol, and triglycerides and decreased high density lipoprotein cholesterol were detected.(ABSTRACT TRUNCATED AT 400 WORDS)

Adult↗
PubMed1995

[Genetic analysis of Werner syndrome in a family].

Werner syndrome (WRN) is a rare autosomal recessive disorder, one of the progeroid syndromes, and is characterized by features of premature aging. The incidence of WRN in the Japanese population, 1 in 200,000, is higher than than that in the Caucasian population. The genetic defect of WRN is unknown. But genetic linkage to several markers on the short arm of chromosome 8 has been reported recently. Here, we studied one family with WRN in which an affected individual had a papillary thyroid carcinoma and myelodysplastic syndrome. Using 4 microsatellites closely located to the WRN locus: D8S360, D8S1055, D8S339 and ANK1, we analyzed the genotypes of this patient, her three siblings and her parents, who were first cousins. The mutative haplotype, identified through the generations in pedigree, helps detect a carrier or a presymptomatic patient. The eldest sister inherited two normal haplotypes, but the second sister inherited one mutative haplotype. There was no difference in clinical signs and symptoms between these sisters. when the WRN gene is isolated, it will help us understand the mechanism of aging.

Adult↗
PubMed1994

[Study of left ventricular function in cerebral thrombosis with pulsed Doppler echocardiography].

To evaluate the cardiac dysfunction of the cerebral infarction (cerebral thrombosis) patients in the chronic period, non-invasive studies were performed on 45 cerebral infarction patients (CI group: 25 males and 16 females, mean age 64.1 y). Forty hospitalized patient without cerebral infarction served as controls (non-CI group: 23 males and 19 females, mean age 64.8 y). The CI and non-CI group were divided into two sub-groups: patients with a past history of hypertension (HT) and without (NT). In each sub-group, the cardiac functions were compared between CI and non-CI by M-mode and Doppler echocardiography. In echocardiography, research based on the premise that the function of the left ventricle can be divided into preload (EDVi), afterload (SVR), contractility (EF, mVcf, SBP/ESV) and distensibility (E/A). On results show that there were no significant differences in preload, afterload and contractility of the left ventricle between CI and non-CI group in each HT and NT sub group. However, a significant difference was demonstrated in the diastolic function the left ventricle between the two groups in the HT (p = 0.007) and NT (p = 0.04) sub-groups. In conclusion, left ventricle diastolic function was deteriorated in cerebral infarction patients although systolic function not deteriorated. Because diastolic dysfunction may be caused by existing latent heart failure and/or silent myocardial ischemia, echocardiographic study is useful for early detection of left ventricle impairments in cerebral infarction patients.

Aged↗
PubMed1993

Are adolescent suicide attempters noncompliant with outpatient care?

The outpatient clinic attendance patterns of 115 consecutively referred 10- to 18-year-old suicide attempters and of 110 nonattempters were compared. The two groups did not differ in number of appointments scheduled or missed, but attempters kept significantly fewer appointments than did nonattempters. Seventy-seven percent of each group dropped out of treatment, but attempters dropped out significantly faster. Attendance and dropout were unrelated to age, reason for referral, or previous attempts. Girls missed more appointments than did boys, and Hispanic patients kept a smaller percentage of scheduled appointments than did other ethnic groups. We conclude that adolescent attempters are not more likely to drop out of treatment but keep fewer appointments and remain in care more briefly than do other outpatients. Recommendations for triage and brief case management are made.

Adolescent↗
PubMed1991

Cognitive ability and everyday functioning in women with Turner syndrome.

This paper presents results from an assessment of cognitive ability and everyday functioning in a group of adult women with Turner syndrome (TUS). Twenty-three TUS women were compared with 23 matched controls with constitutional short stature (CSS). A subgroup of 10 TUS women were compared with their nondisabled female siblings. On the Wechsler Adult Intelligence Test-Revised (Wechsler, 1981), no significant group differences were found in Verbal IQ. There were significant group differences for Performance IQ and Full Scale IQ, largely due to specific deficits in the area of spatial and mathematical ability. These difficulties were also evident on the Benton Visual Retention Test-Revised (Benton, 1974). TUS individuals had significantly lower educational attainment than CSS controls but did not differ from their siblings. TUS individuals had significantly lower occupational attainment than the women in both comparison groups.

Achievement↗
PubMed1990

Thyroid adenoma following treatment of acute lymphocytic leukemia.

Sequelae of the treatment of children with acute lymphocytic leukemia (ALL) include multiple effects on the endocrine system, especially as it relates to growth and puberty. Thyroid dysfunction, and in particular, the occurrence of thyroid neoplasia, has been only rarely described. We report the development of benign thyroid neoplasms in two patients 9 years following the diagnosis and treatment of ALL. Both patients were clinically and biochemically euthyroid with noncystic "cold" nodules found on thyroid scan. In light of these observations, and along with previous reports of malignant thyroid neoplasia in children with ALL, long-term careful observation of children successfully treated for ALL is indicated.

Adenoma↗
PubMed1989

Psychopathology and social functioning in women with Turner syndrome.

Turner syndrome (TUS) in women is associated with sex chromosome abnormalities, ovarian dysgenesis with estrogen deficiency, and short stature. The goal of this study was to assess the long-term effects of these sex chromosome and hormonal anomalies on psychopathology and social functioning. We report interview and questionnaire data concerning lifetime history of mental disorders and current psychiatric symptoms. Also reported are data from questionnaires and interviews evaluating social functioning as measured by education, occupation, personal resources, and sexual behavior. Twenty-three TUS women were studied and compared with 23 closely matched women with constitutional short stature (CSS) and with 10 normal sisters of the TUS women. TUS women reported generally less mental disorder and comparable rates of psychiatric symptoms. On the other hand, they had lower overall functioning on a measure of global psychological health and had more impairment in social functioning as measured by achievement of adult milestones. We conclude that TUS women display less mental illness by positive symptom-oriented criteria but also less mental health when day-to-day functioning is considered. Our data suggest that differences in TUS women cannot be explained solely by short stature and may be related to other psychosocial, genetic, endocrine, or CNS effects of the syndrome.

Achievement↗