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Biomedical subjects

K Nonaka

Publications and source records attributed to K Nonaka.

At least 181 records · Page 10Linked to original sources
PubMed1990

Changes in the eruption order of the first permanent tooth and their relation to season of birth in Japan.

In order to examine the eruption order of the first two permanent teeth, kindergarten children 5 to 6 years old were examined in Hakone, Japan. Among a total of 817 children examined from 1976 to 1984, 349 were determined as I-type children, whose mandibular first incisor erupted earlier than the mandibular first molar, and 183 were as M-type children, whose first molar erupted earlier in the mandible. The mandibular I-type rate, i.e., the proportion of the I-type among a total of I- and M-type children, was 66% (349/532). In 1983-1984, the I-type rate was 70% among boys and 62% among girls, but the overall I-type rate did not differ significantly by the sex of the subject or by the year of examination. The I-type rate varied significantly with the season of subject's birth. Those born in October or November showed a significantly lower I-type rate (33%) than the other subjects (P less than 0.001), in spite of a shift of birth season with low I-type rate toward winter in 1983-1984. The difference of the I-type rate according to birth season suggests that the causes responsible for this change are primarily environmental and act at the prenatal or perinatal stage of life.

Age Factors↗
PubMed1990

Decrease in twinning rate in a hospital in Tokyo during World War II.

In order to investigate changes in twinning rate during World War II and postwar years, when the people in Tokyo suffered from malnutrition, about 80,000 delivery records during 1924-86 at one hospital in downtown Tokyo were examined. The twinning rate decreased from 1.47% in the 1920s to 0.81% in the 1980s. During the 1940s, the rate was 1.03% for 1940-42 and 0.94% for 1948-49, but it dropped down to 0.70% for 1943-47. In 1945, when Tokyo was heavily bombed repeatedly to be burnt out, and the people suffered from severe malnutrition, only one case of twinning was found among 305 maternities at this hospital (0.33%). While the mean birth weight of term singleton babies was 2953 g in 1940-41, it decreased to 2918 g in 1943-47, especially to 2856 g in 1945. This change in birth weight evidenced that the nutritional conditions in Tokyo became worse in 1943-47. This report suggests that the twinning rate decreased also during this period in Tokyo when the people suffered from malnutrition.

Female↗
PubMed1990

Seasonality in early loss of one fetus among twin pregnancies.

Ultrasonographic examinations were performed on 519 pregnant women in the first trimester at three hospitals in Tokyo from August 1985 to March 1987. Among 519 women, two fetal heart movements (FHMs) were confirmed in six cases. In two of these six cases, one of two FHMs disappeared two weeks later, and these were considered the "vanishing twin". In eight cases among those with ultrasonographic image of echo-free-space (EFS) in the uterus, the observed EFS was considered to be a probable empty gestational sac (GS-like-EFS-image). Seven of eight GS-like-EFS-images were observed in October-December (p less than 0.01) and two "vanishing twin" cases were also observed in the same season. Spontaneous abortion occurred in 11 cases and these were also more frequently observed in October-November (p less than 0.05). Some abortive factor is supposed to have prevailed in October-December. All six women having twin fetuses (including the "vanishing twin" cases) were born in January-May (p less than 0.05) and those having GS-like-EFS-images or terminating their pregnancy in spontaneous abortion were also born more frequently in the same season. Twin-prone and abortion-prone characteristics of the women born in this season are considered.

Diseases in Twins↗
PubMed1990

Inhibition of cytokine-induced MHC class II but not class I molecule expression on mouse islet cells by niacinamide and 3-aminobenzamide.

Normal mouse islet cells express low levels of MHC class I molecules and undetectable or extremely low levels of MHC class II molecules. Class I expression was dose-dependently augmented by incubation with interferon-gamma (IFN-gamma) or tumor necrosis factor (TNF). Although neither IFN-gamma nor TNF alone induce class II molecules on islet cells, synergistic interaction of IFN-gamma (200 U/ml) and TNF (200 U/ml) may induce class II expression on approximately 50% of islet cells. Niacinamide and 3-aminobenzamide, both inhibitors of ADP ribosylation and scavengers of free radicals, attenuated the class II expression induced by IFN-gamma and TNF. Twenty millimolar niacinamide and 10 mM 3-aminobenzamide reduced the rates of class II antigen-positive cells to mean +/- SD 3.6 +/- 0.3 and 6.1 +/- 1.9%, respectively. The agents did not affect the cytokine-induced augmentation of class I antigens. The inhibition of class II molecule expression may at least partly account for the preventive effect of niacinamide on autoimmune-associated beta-cell damage in NOD mice.

Animals↗
PubMed1990

Genetic study of dentinal growth in mandibular first molars of mice.

The dentinal growth of mandibular molars of mice could be determined by genetic and environmental factors as are other quantitative characters, such as crown size and craniofacial size. To study the relative contribution of genetic and environmental factors to dentinal growth, a partial diallel cross was carried out by the mating of one pair from each of six strains of mice. In each F1 offspring, the total amount of dentinal formation in the first molar of the right mandible was quantified as a volume by the time-marking method, using nitrilotri-acetate lead with the computerized image scanning system, and then analyzed by a quantitative genetic method. The result obtained was as follows: In either sex, both additive genetic and nonadditive genetic variance components of the accumulative volume of dentinal formation in the first molar were relatively large throughout the experimental period, while the environmental variance component was much smaller. Thus it could be concluded that the genetic factor contributed more to the whole process of dentinal growth in the first molar rather than the environmental one in this F1 population.

Analysis of Variance↗
PubMed1990

Thyroidectomy reduces stress-induced prolactin secretion in rats. Participation of brain serotonergic systems.

Plasma prolactin levels were measured in thyroidectomized and sham-operated rats under immobilization stress. Thyroidectomy significantly reduced prolactin secretion during stress. The pretreatment of thyroidectomized rats with 6-chloro-2-[1-piperazinyl]- pyrazine (MK 212), a serotonin agonist that easily penetrates the blood-brain barrier, reversed the reduction in stress-induced prolactin release in the thyroidectomized group.

Animals↗
PubMed1990

[Effect of maxillary protracting bow appliance on reversed occlusion in deciduous dentition].

Previously we investigated the frequency of malocclusion in children who visited the Pedodontic Clinic of Kyushu University and the types of appliances to treat the reversed occlusion in deciduous dentition. The purpose of this study was to evaluate the effects of the maxillary protracting bow appliance to the reversed occlusion in deciduous dentition. Patients at the Hellman's dental age IIA and without molar cross-bite were selected. Eleven patients (6 males and 5 females) were treated with the maxillary protracting bow appliance, and 9 patients (5 males and 4 females) were treated with the chin cap. The controls were 15 patients (5 males and 10 females) without, distal step type of terminal plane, caries and malocclusion. For the sake of evaluation, the study models and lateral cephalograms were analyzed, which were taken before and after the correction of reversed occlusion. The results were as follows: 1. The effects of maxillary protracting bow appliance were the maxillary forward movement associated with counter-clockwise rotation of the nasal floor and the mandibular backward movement associated with clockwise rotation. 2. The maxillary protracting caused the labial inclination of the primary incisors in the maxilla, but the dental arch length was reduced by the mesial movement of the primary second molars in the maxilla. 3. From the results of multiple regression analysis in the maxillary protracting group, it was indicated that the increase of the overjet was attributable to the change of angles of SN-GN, SNB, SNA and GZN.

Cephalometry↗
PubMed1990

Protective effect of nicotinamide and 3-aminobenzamide on islet cell damage induced by gamma-interferon and tumor necrosis factor.

Mouse islet cell monolayers were damaged when cultured for five days in a medium containing 200 U/ml of recombinant murine interferon-gamma (IFN-gamma) and 300 U/ml of recombinant tumor necrosis factor (TNF). The cells formed granular clusters and ultimately floated in the medium; the floating cells proved to be dead by the trypan-blue dye-exclusion method. When 20 mM of nicotinamide or 5 mM of 3-aminobenzamide was supplemented to the medium, islet cell monolayers remained in the presence of the cytokines. 51Cr release studies showed that specific 51Cr release during five-day incubation with 200 U/ml of IFN-gamma and 300 U/ml of TNF was 30 +/- 4% (mean +/- SE). In a medium containing 20 mM of nicotinamide, together with IFN-gamma and TNF, specific 51Cr release was significantly reduced (12 +/- 3%, p less than 0.01). 3-aminobenzamide was effective at the level of 5 mM; specific 51Cr release was 2 +/- 5% (p less than 0.01). These results suggest that the mechanism by which IFN-gamma and TNF damage islet cells may be similar to that of streptozotocin and/or alloxan.

Animals↗
PubMed1990

[A case of lymphocytic adenohypophysitis associated with sarcoidosis of the lung and eye].

Lymphocytic adenohypophysitis is considered to be an inflammatory disease of the adenohypophysis that is commonly present with visual disturbance and hypopituitarism. Its etiology remains unclear but it is often related to an autoimmune disorder involving other organs, such as the thyroid, parathyroid, or adrenal glands. We encountered a rare case of lymphocytic adenohypophysitis associated with sarcoidosis of the lung and eye during the follow-up period. A 23-year-old woman was hospitalized in July 1986, with a one-month history of headache and visual disturbances which began three days after her second normal delivery. On admission, she showed slight visual impairment and had a left temporal superior quadrantanopia. Endocrinological evaluation revealed thyroid and adrenal hypofunction, and low response of human growth hormone to the loading test. A skull X-ray showed normal shaped sella with some erosion of the dorsum. CT scan showed a rounded contrast-enhanced intrasellar mass extending into the suprasellar cistern. MRI (SR: 500/30) showed a homogeneous low intensity mass which contained a small high intensity area on the relative T2-weighted image (2000/50). A biopsy was performed via right frontotemporal craniotomy. The consistency of the resected tissue was firmer than that of pituitary adenoma. Histologically, the tissue showed diffuse lymphocytic infiltration with some normal adenohypophysis. Her postoperative course was uneventful and the visual impairment improved two months later after the operation. Six months after the operation, she was readmitted with complaints of general fatigue and breathlessness. Chest X-ray showed diffuse infiltration throughout both lung fields, but there was no bilateral hilar lymphadenopathy.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1990

Effects of maternal birth season on birth seasonality in the Canadian population during the seventeenth and eighteenth centuries.

Birth records of the French-Canadian population for the period 1621-1765 were analyzed retrospectively to examine the effect of maternal birth season on the seasonal distribution of births. Preliminary examination indicated that there was a bimodal pattern in birth seasonality: a major peak in early spring, a trough in early summer, a minor peak in autumn, and a trough around December. Because this seasonality was strongly biased at the level of the first birth by the month of marriage, which was concentrated in November, the seasonality of nonfirst births (n = 32,926) was examined in relation to the four seasons of maternal birth. Mothers born in May-July showed a flatter monthly distribution of nonfirst births at a maternal age of 28 years or more. Analysis of marriage-first birth intervals indicated that mothers who married in August-October showed a lower percentage of immediate conception (intervals of 8-10 months), whereas those mothers born in May-July had a higher percentage of immediate conception. This difference in birth seasonality shown by mothers born in May-July is similar to results from early twentieth-century Japan. Some seasonal infertility factors could have affected the embryos at the earliest stage of pregnancy, modifying a part of the seasonal variation in birth rate.

Birth Intervals↗
PubMed1990

[Serum adenosine deaminase and its isozyme activity in leukemia and MDS].

We studied the activity of serum adenosine deaminase (ADA) and its isozyme in 36 leukemic patients (16 ANLL, 11 ALL, and 9 CML) and 8 MDS. Isozyme was measured by erythro-9-(2-hydroxy-3-nonyl) adenine (EHNA) inhibitory assay. This assay was simple and reliable. The appearance rate of abnormally high ADA value were 81.24% for ANLL, 100% for ALL, 77.8% for CML and 37.5% for MDS. The ADA level became high when MDS turned into overt leukemia. In isozyme pattern, there was a clear difference between ANLL and ALL. The isozyme I/II ratio was significantly higher (p less than 0.001) in ALL than ANLL. Lymphoblastic crisis of CML also had a high isozyme I/II ratio. There was a correlation between isozyme I and absolute number of peripheral blasts in ALL (r = 0.768). When observed time sequentially, ADA and isozyme changed correlatively with the number of blasts counts. Serum ADA and its isozyme are useful parameters both for leukemic diagnosis and treatment.

Adenosine Deaminase↗
PubMed1990

Effects of age and body mass of recipients on survival of transferred embryos in mice.

To examine the effects of age and body mass of recipients on embryo survival during gestation, ICR embryos were transferred to nulli- or primi-parous females of 4 strains of mice. Out of 530 recipients, 383 (72.3%) produced a litter. Transfer of 3,465 embryos to 383 recipients resulted in production of 1,637 pups born alive, an overall rate of embryo survival of 47.2 +/- 1.1%. Regression analyses revealed that embryo survival decreased in older recipients and increased in heavier recipients. The results were consistent in each parity/strain group and all groups combined.

Age Factors↗
PubMed1990

Genetic study on the mandibular molar size of rats.

Tooth size is determined by genetic and environmental factors like other quantitative characters such as body weight and body height. However, the degree of the relative contribution of both factors to the determination of tooth size has not been well clarified. In order to study the genetic and environmental factors affecting tooth size, we carried out a diallel cross mating by the cohabitation of pairs of males and females among 10 strains of rats. The bucco-lingual widths of the first, second, and third molars of the right mandible were measured in each offspring of F1 population. The body weight was also measured as a parameter that might indicate systemic growth factor in connection with tooth development. The quantitative genetic analysis was performed based on Wearden's model (Heredity 19:669-680, 1964). As a result, the size of the first and the second molars was more significantly controlled by genetic effect than maternal effect, while maternal effect could not be ignored for the size of the third molar in addition to genetic effect. The genetic effect on body weight became greater with age, while the maternal effect showed its maximum influence upon the body weight around the weaning. It is concluded that the size of the molar teeth beginning to develop in the uterus and to be calcified just after birth was mainly controlled by genetic factor, and that the size of the molar teeth beginning to develop approximately after birth was mainly controlled by maternal effect affecting body weight at the same period.

Animals↗
PubMed1990

[Combination assay of IAP and ADA in hematologic malignancies].

We measured the levels of adenosine deaminase (ADA) and immunosuppressive acid protein (IAP) in 10 patients with acute myeloid leukemia (AML), 5 with acute lymphoblastic leukemia (ALL), 8 with chronic myeloid leukemia (CML), 7 with myelodysplastic syndrome (MDS), 5 with malignant lymphoma (ML), 3 with multiple myeloma (MM) and one with adult T cell leukemia. On admission, the level of IAP was abnormally high in all cases of AML and ALL 50% of CML cases, 71.4% of MDS cases, 60% of ML cases and none of MM cases. ADA was elevated in all cases of ALL, 77.8% of AML and CML cases, 57.1% of MDS cases, 60% of ML cases and 33.3% of MM cases. In 7 patients with AML, the level of IAP returned to normal when they achieved complete remission. On the other hand, the level of ADA had already returned to normal even during induction therapy. ADA showed a positive correlation with the absolute number of peripheral blasts and lactic dehydrogenase both in AML and ALL. These results suggest that ADA indicates the activity of leukemia and IAP indicates the immunocompetence of the host.

Adenosine Deaminase↗
PubMed1989

Physicochemical properties of crystalline forms of ethynylestradiol solvates: comparison of thermal behavior with X-ray crystal structure.

Four crystalline forms of ethynylestradiol solvates were obtained from three solvents [acetonitrile (Form A), methanol (Form B), and chloroform saturated with water (Forms C and D)], and were characterized by X-ray powder patterns and thermal analyses. The crystal structures of Forms A, B, and C were further analyzed using the X-ray diffraction method, and the results are discussed in comparison with the thermal behavior of the crystalline forms. The steroid conformation of ethynylestradiol was rigid and no noticeable difference was observed among the solvated crystal structures; the molecular structure differed only in the orientation of the ethynyl group with respect to the steroid skeleton. The difference in the interaction mode between ethynylestradiol and the solvent molecules primarily discriminates the physicochemical properties.

Calorimetry↗
PubMed1989

Effect of delivery season on subsequent birth interval in early 20th century in Japan.

Questionnaires of birth dates of family members (13,404 families in total) were analyzed in order to examine the effects of delivery season of a baby on the subsequent birth interval. Deliveries at maternal age of 20-34 years were used. In 1921-1935, the mothers who had been delivered of a baby in August-October showed the shortest (30.62 months geometric mean) and those in February-April the longest (34.05 months) non-last intervals, with a highly significant difference among the four delivery seasons (P less than 0.001, Kruskal-Wallis test, n = 5678). Although the intervals were abruptly prolonged just before the last birth, the above difference was also consistent in the last intervals. When seasonal distributions of last and non-last births were compared, last births tended to be concentrated in the summer half of a year (P less than 0.05) in 1921-1935. In 1951-1965, overall geometric mean of the interval shortened to 28.44 months, and the length of intervals did not differ appreciably according to the season of preceding delivery. Deliveries in late summer (August-October) in 1921-1935, therefore, were associated with increased risk of termination of reproduction, on one hand, but a lowered chance of prolongation of the subsequent interval, on the other hand. Possible environmental factors are discussed to explain this apparently paradoxical phenomenon.

Adult↗
PubMed1989

Growth and reproduction of mice developed from bisected embryos.

Embryos from three groups of mice, ICR (I), a synthetic (S), and an F(1) hybrid from C57BL males and S females (F), were used to examine effects of embryo bisection on subsequent viability, postnatal growth and reproduction. In two experiments, Group S females used as recipients received the following combinations of whole (W) and/or bisected (B) embryos: W(I) and W(F), W(I) and B(F), B(I) and W(F), and B(I) and B(F) in Experiment 1 and W(I) and W(S), W(I) and B(S), B(I) and W(S), and B(I) and B(S) in Experiment 2. Eight to 12 embryos of both types were transferred surgically to two horns of the uterus. Overall survival rate of whole embryos (32.6%) was significantly greater (P < 0.001) than that for demi-embryos (13.2%). The gestation period after transfer was significantly longer (P < 0.05) for demi-embryos (17.5d) than for whole embryos (16.4 d). Mice developed from demi and whole embryos were not different in mean body weight at birth and at 21, 42 and 63 d of age. Fertility and litter size at first parity of mice that developed from bisected embryos were comparable with those that developed from whole embryos. Hence, bisection decreased embryo viability, increased gestation period of recipients but did not affect postnatal growth and reproduction.

Journal Article↗