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Biomedical subjects

K Kikuchi

Publications and source records attributed to K Kikuchi.

At least 613 records · Page 34Linked to original sources
PubMed1995

Long-term effects of radioiodine on thyrotrophin receptor antibodies in Graves' disease.

OBJECTIVE: Graves' disease is recognized as an organ-specific autoimmune disorder caused by the presence of TSH receptor antibodies. The long-term effects of 131I treatment for Graves' disease on TSH receptor antibodies have not previously been studied. We have measured the TSH-binding inhibitory immunoglobulin (TBII) index and thyroid stimulating antibody (TSAb) activity in patients with Graves' disease following treatment with 131I. DESIGN: A retrospective study. PATIENTS: Two hundred and twenty-five patients with Graves' disease who were treated with 131I 1-13 years earlier were studied (1 year: 27 patients; 2-5 years: 42 patients; 6-9 years: 79 patients; 10-13 years: 77 patients). MEASUREMENTS: The TBII index was measured as the percentage 125I-TSH bound to pig thyroid membranes and TSAb activity as the amount of cAMP produced by cultured FRTL-5 cells. RESULTS: TBII was detected in 78% of patients prior to 131I administration. Following 131I administration, the incidence of positive TBII was 85% at the end of the first year decreasing to 40, 19, and 17% at 2-5, 6-9 and 10-13 years, respectively. The frequency of a positive TSAb was 74% at the end of the first year, and also decreased to 49, 27 and 29% at 2-5, 6-9 and 10-13 years, respectively. At more than 2 years after 131I therapy, the frequencies of hyperthyroidism in TBII and TSAb positive patients were 42% (19/45) and 30% (19/63), respectively, which were significantly higher than those in TBII and TSAb negative patients (8%: 12/153 and 8%:11/131, respectively). The frequency of hyperthyroidism after 131I treatment in patients with negative TBII before treatment (7%:2/29) was significantly lower than that (29%:30/102) in patients with positive TBII before treatment. CONCLUSIONS: These results indicate that (1) the TBII index and TSAb activity decreased over a period of more than 2 years after 131I therapy for Graves' disease, and (2) the TBII index before treatment may influence the long-term outcome of 131I therapy.

Adult↗
PubMed1995

White matter hyperintensity in neurologically asymptomatic subjects.

Recent advances in magnetic resonance imaging (MRI) technology have had a great impact on the delectability of minute, asymptomatic lesions of the central nervous system. The clinical significance and treatment modes of these lesions, such as white matter hyperintensity (WMH) lesions detected by T2 MRI, remain controversial. To address these problems, we retrospectively evaluated WMH lesions in relation to clinical parameters for 240 neurologically asymptomatic persons who had visited a hospital for a medical check-up of the brain. Proton and T2-weighted MRI were obtained using a 0.5 T superconducting MR imager using the spin echo technique with a repetition time (TR) of 2800 msec. An echo delay times (TE) of 40 msec was used for the proton MRI, and a TE of 100 msec was used for the T2-weighted MRI. The images were visually analyzed according to a four-point grading system. The MRI findings were correlated with clinical parameters including age, gender, presenting symptoms, and hypertension. The overall frequency of WMH increased with age. Grades 2 and 3 of WMH were more frequent in aged persons, whereas the occurrence of grade 1 WMH remained relatively constant across age groups. Based on multiple regression analysis, age was the most significant variable influencing the frequency of WMH, followed by hypertension. These results imply that WMH lesions may simply be a phenomenon of aging, or may be an indicator of prepathologic state in an ischemic brain.

Adolescent↗
PubMed1995

Congenital hypopituitarism with hypoplasia of the anterior pituitary gland and a normal posterior pituitary lobe.

We report a female infant with congenital hypopituitarism. All anterior pituitary hormones were deficient, and the anterior pituitary gland was undetectable on magnetic resonance images. Antidiuretic hormone secretion was appropriate, and the posterior lobe was localized at the end of the stalk, in the sella. These observations suggest that the posterior pituitary gland may develop independently of the anterior lobe.

Female↗
PubMed1995

Comparison of phenotypic characteristics, DNA-DNA hybridization results, and results with a commercial rapid biochemical and enzymatic reaction system for identification of viridans group streptococci.

The rapid ID 32 Strep system (bioMérieux, Marcy l'Etoile, France) was evaluated for its ability to identify 21 species of viridans group streptococci; results were compared with DNA-DNA hybridization results and results of conventional physiological tests. A total of 171 strains of the 21 species including 147 clinical strains was analyzed. Of the 156 strains of species included in the database of this system, 136 strains (87%) were correctly identified. Incorrect identification occurred for 13 strains (8%), and no identification was given for 7 strains (5%). It was difficult to differentiate S. mitis and S. oralis accurately with this system. Of the 17 strains identified as S. mitis by the rapid ID 32 Strep system, the results of DNA-DNA hybridization were in agreement for only 3 strains. S. crista and S. parasanguis, which are not included in the database, were identified as S. mitis or S. sanguis or were not identified, but S. parasanguis could probably be identified by using the rapid ID 32 Strep system because the biochemical profile is well characterized for this species. The rapid ID 32 Strep system can be used to differentiate most species for which phenotypic characteristics have been described if the database is revised according to recently reported amended criteria for the identification of viridans group streptococci. However, identification of a few species such as S. mitis and S. oralis is problematic with this system.

Bacterial Typing Techniques↗
PubMed1995

Effects of various growth factors and histamine on cultured keloid fibroblasts.

OBJECTIVE AND METHODS: We investigated the effects of several growth factors on [3H]thymidine incorporation and procollagen type I carboxyterminal propeptide (P1CP) production, which reflects type I collagen metabolism, in keloid and normal fibroblasts. RESULTS: Six fibroblast cell strains, derived from keloid or normal skin, exhibited similar growth responses to platelet-derived growth factor, transforming growth factor beta 1 (TGF-beta 1), gamma-interferon (gamma-IFN) and histamine. In contrast, keloid fibroblasts showed significantly greater growth response to epidermal growth factor (EGF) than normal fibroblasts. P1CP production was 4.4 times higher in 6 strains of keloid fibroblasts than in 6 controls. Treatment with gamma-IFN (100 U/ml) decreased P1CP production in both groups; the effect was significantly greater in keloid fibroblasts. TGF-beta 1 treatment upregulated P1CP production in both groups. Treatment with histamine increased P1CP production in keloid fibroblasts, although it did not change that in the controls. CONCLUSION: EGF and histamine may play some role in the development of keloids.

Cell Division↗
PubMed1995

Elevated procollagen type I carboxyterminal propeptide production in cultured scleroderma fibroblasts.

BACKGROUND: We recently reported that the serum concentration of procollagen type I carboxyterminal propeptide (P1CP) in patients with systemic sclereosis (SSc) was elevated. In the present study, we investigated collagen metabolism in in vitro cultured scleroderma fibroblasts by measuring P1CP levels in the culture medium. METHODS AND RESULTS: Spontaneous P1CP production was 4.2 times higher in fibroblast cultures from patients with SSc (n = 11) than in those from healthy controls (n = 10). P1CP production in fibroblasts derived from diffuse cutaneous SSc patients was significantly greater than that from limited cutaneous SSc patients. The serum P1CP level in SSc patients was correlated with the P1CP production of cultured fibroblasts (r = 0.815, p < 0.005). Transforming growth factor beta increased P1CP production, and gamma-interferon decreased P1CP production similarly in both SSc and normal fibroblasts. In contrast, histamine dihydrochloride increased P1CP production only in SSc fibroblasts but not in controls. CONCLUSION: These findings suggest that P1CP production in SSc fibroblasts is relevant to in vivo collagen synthesis in SSc patients.

Adolescent↗
PubMed1995

Characterization of deoxyribonucleic acid-protein interactions at a growth hormone-inducible nuclease hypersensitive site in the rat insulin-like growth factor-I gene.

Many of the growth-promoting effects of GH are mediated by insulin-like growth factor-I (IGF-I), a highly conserved, 70-residue basic peptide. Previous studies have demonstrated that GH rapidly stimulates IGF-I expression in vivo, and our laboratory has identified a GH-regulated alteration in chromatin configuration, manifested as a hormonally induced deoxyribonuclease-I (DNase-I)-hypersensitive site in the second IGF-I intron. In the current study, we have used in vivo DNase-I footprinting to map this hormonally responsive chromatin domain to an approximately 350-nucleotide region and have identified DNA-protein interactions within the hypersensitive site by in vitro gel mobility shift experiments and DNase-I footprinting studies. DNA-protein binding was localized to two adjacent segments of 32 and 48 nucleotides. In 1 of these regions, protein-DNA contacts were also detected in vivo on guanine residues by dimethylsulfate footprinting. DNA-binding activity was present in GH-deficient rats, but was not modified by hormone treatment. Our results define a rapid and reversible genomic alteration in response to GH in a GH-regulated gene and delineate a target within chromatin for GH action.

Animals↗
PubMed1995

Comparison of 5-hydroxytryptamine-induced contraction of rat pulmonary artery to that of aorta in vitro.

We investigated the nature of the contraction produced by 5-hydroxytryptamine (5-HT) in the rat pulmonary artery, and compared it with that produced in the rat aorta. Both ketanserin and ritanserin inhibited 5-HT-induced contraction in the pulmonary artery non-competitively. In contrast, ketanserin competitively antagonized the contraction in the aorta. Bunazosin, a selective alpha 1-blocker, partially inhibited 5-HT-induced contraction in the pulmonary artery, but not in the aorta. In both the pulmonary artery and aorta, 8-OH-DPAT, a 5-HT1A selective agonist, produced a concentration-dependent contraction. In the pulmonary artery, 5-HT and 8-OH-DPAT produced contractions with similar potencies. In contrast, 8-OH-DPAT was less potent than 5-HT in the aorta. Bunazosin inhibited 8-OH-DPAT-induced contraction in both vessels. However, pindolol, a 5-HT1A antagonist, did not inhibit 8-OH-DPAT-induced contraction in the pulmonary artery. These results suggest that 5-HT produces contraction via not only 5-HT2 receptor, but also non-5-HT2 receptor (probably alpha 1-adrenoceptor) in the rat pulmonary artery. Furthermore, 8-OH-DPAT does not activate the 5-HT1A receptor to produce a contraction, but does activate other receptors which interact with alpha 1-adrenoceptor.

8-Hydroxy-2-(di-n-propylamino)tetralin↗
PubMed1995

Regional localization of rat and mouse protein-tyrosine phosphatase PTP alpha/LRP gene (Ptpra) by fluorescence in situ hybridization.

Protein tyrosine phosphatases (PTPases) negatively regulate the effect(s) of protein tyrosine kinases and are implicated in the regulation of a variety of biological events including cell activation, differentiation, and neoplastic transformation. To gain insight into the role(s) of the PTPases, we mapped the gene encoding for the widely expressed receptor-like protein tyrosine phosphatase PTP alpha/LRP (locus symbol Ptpra) to rat chromosome 3q36 and mouse chromosome 2G by fluorescence in situ hybridization method. These results indicate that there is a conserved syntenic group between human 20p13, rat 3q36, and mouse 2G.

Animals↗
PubMed1995

Purification and properties of extracellular carboxyl proteinase secreted by Candida pulcherrima.

An extracellular proteinase secreted by Candida pulcherrima KSY 188-5 was purified about 60-fold to electrophoretical homogeneity from its culture supernatant, by ammonium sulfate fractionation, anion-exchange chromatography, and gel filtration. The proteinase had a molecular weight of approximately 36,500 and an isoelectric point of pH 4.7. The enzyme had an optimum pH of around 2.5-3.5 for activity and 3.0-5.0 for stability. The optimum temperature was around 45 degrees C at pH 3.0. The enzyme showed a broad substrate specificity for a variety of proteins to hydrolyze casein, BSA, hemoglobin keratin, and collagen. Among several proteinase inhibitors, pepstatin A completely abolished the enzyme activity; indicating that the extracellular proteinase from C. pulcherrima KSY 188-5 was classified in the group of carboxyl proteinases.

Amino Acids↗
PubMed1995

[Macrophage colony-stimulating factor in patients with rheumatoid arthritis].

Macrophage colony-stimulating factor (M-CSF) is a cytokine involved in the development and proliferation of the monocyte/macrophage lineage cells. M-CSF has also been reported to participate in the induction of osteoclasts, and may be important in the destruction of bone and cartilage and the periarticular osteoporotic changes seen in patients with rheumatoid arthritis (RA). We developed a new ELISA technique to measure M-CSF levels in synovial fluid with high sensitivity and reproducibility. The mean M-CSF level in the synovial fluid of patients with RA was 1.38 +/- 0.56 ng/ml, and that of patients with osteoarthritis (OA) was 0.67 +/- 0.13 ng/ml. In contrast, serum levels of M-CSF in patients with RA and in normal controls were 1.32 +/- 0.50 ng/ml and 0.90 +/- 0.09 ng/ml, respectively. These differences were both statistically significant. Since serum M-CSF levels correlate with inflammatory signs obtained from examination of blood, they indicate the general condition of patients with RA. Synovial fluid M-CSF levels increase even in the early phase of RA and remain high despite drug therapy, which suggests that they reflect the condition of affected joints including joint spaces and inflamed synovia more directly than do the levels of serum M-CSF. Measurement of the M-CSF level in the synovial fluid may be useful in the diagnosis, clinical evaluation, and assessment of the effects of treatment in patients with RA.

Adult↗
PubMed1995

Thyroid hormone regulates rat placental type III iodothyronine deiodinase activity by inducing kinetic changes different from those in the same isozyme in rat brain.

The kinetics of type III iodothyronine deiodinase (5-D) in rat placenta and brain and the role of phospholipids in enzyme activity were determined. Pregnant Sprague-Dawley rats were given either vehicle (control group) or T4 (15 micrograms/100 g bw/day; hyperthyroid group) from the 14th to the 21st day of gestation. Mitochondrial-microsomal fractions of the placenta and brain were used as the source of T4 5-D. Placental T4 5-D activity in the hyperthyroid group was increased when determined at 13 nM T4, but it was not significantly different from the control value when assayed at 1.3 microM T4. In contrast, T4 5-D in the brain was significantly increased in the hyperthyroid group regardless of the substrate concentration. Hyperthyroid rats showed decreased Km for placental 5-D and increased Vmax for brain 5-D. CM-Sephadex chromatography of solubilized placental microsomes was performed to determine whether phospholipids cause a reduction in the Km of placental 5-D in hyperthyroid rats. T3 5-D activity was undetectable unless protein-containing fractions were combined with phospholipid-containing fractions in the reaction mixture. Kinetic studies revealed that phospholipids had no effects on either Km or Vmax of placental T3 5-D. These data indicate that 5-D activity in the rat placenta is increased in hyperthyroidism with different kinetic changes from those in the brain, and that phospholipids have no effects on the kinetic parameters of placental 5-D whereas they are essential for the enzyme activity.

Animals↗
PubMed1995

Decrease of histone H1 kinase activity in relation to parthenogenetic activation of pig follicular oocytes matured and aged in vitro.

Changes of histone H1 kinase activity before and after electrical stimulation were connected with the ability of cytoplasm of pig oocytes to be activated parthenogenetically when matured and aged in vitro. Cumulus-oocyte complexes were collected from prepubertal gilts and cultured in a modified Waymouth's MB752/1 medium. The first mature oocytes were observed after 30 h of culture. After 36 h of culture, about 65% of oocytes had matured (reached metaphase II stage with the first polar body). When oocytes matured after 36 h of culture were stimulated with an electric pulse and subsequently cultured for 10 h, only 7% became parthenogenetically activated (formation of a female pronucleus). When oocytes matured for 60 h and 72 h underwent the same treatment, significantly more became activated parthenogenetically (46% and 57%, respectively). Oocytes matured for 72 h but not stimulated electrically also exhibited high spontaneous parthenogenetic activation (24%). Activation of oocytes resulted either in the formation of a female pronucleus(ei) or in fragmentation of oocytes. Fragmentation in stimulated and nonstimulated oocytes increased significantly after 72 h of culture (37% and 18%, respectively). Histone H1 kinase activity in immature oocytes at the germinal vesicle stage was low (17.2 fmol h-1 per oocyte). However, when oocytes were cultured for 36 and 48 h, histone H1 kinase activity increased significantly (168.2 and 138.5 fmol h-1 per oocyte, respectively). Prolonged culture (60 h and 72 h) resulted in a significant decrease in histone H1 kinase activity (94.3 and 49.3 fmol h-1 per oocyte, respectively). When oocytes cultured for up to 72 h were electrically stimulated, histone H1 kinase activity in activated oocytes (oocytes that formed a female pronucleus and fragmented oocytes) was significantly lower (24.7 mol h-1 per oocyte) than that in nonactivated oocytes (99.9 mol h-1 per oocyte). The present data clearly indicate that the gradual decrease of histone H1 kinase activity is correlated with ageing of oocytes matured in vitro and with their ability to be parthenogenetically activated.

Animals↗
PubMed1995

Effects of upper limb exercise on thermoregulatory responses in patients with spinal cord injury.

We evaluated changes in body temperature, heart rate, and oxygen uptake during arm cranking exercise (20 watts, 30 min) in an artificial climate room at a temperature of about 25 degrees C or 35 degrees C (relative humidity, about 50%) in 5 patients with paraplegics due to spinal cord injury (SCI). The tympanic temperature (Tty) was significantly higher from rest to recovery at 35 degrees C than at 25 degrees C. The mean Tty after 10 minutes of rest was 36.68 degrees C +/- 0.396 (mean +/- SD) at a room temperature of 25 degrees C and 37.25 degrees C +/- 0.253 at 35 degrees C, showing a difference of about 0.5 degrees C. This difference was maintained during exercise and recovery. The Tty at the end of exercise was higher than that at the start of exercise by 0.66 degrees C +/- 0.218 (mean +/- SD) at 25 degrees C and by 0.59 degrees C +/- 0.210 at 35 degrees C. The skin temperature (Tsk) in each measurement area (the head, arm, chest, thigh, shin, and calf) was significantly higher at 35 degrees C. Oxygen uptake did not differ between 25 degrees C and 35 degrees C. The heart rate was significantly higher at 35 degrees C than at 25 degrees C during rest and at the start of exercise but did not differ during exercise and recovery. Thus, mild-moderate exercise in this study did not cause marked changes such as increases in body temperature and heart rate that affect biological function in SCI.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1995

Relationship among blood lactate and plasma catecholamine levels during exercise in acute hypoxia.

Five male subjects performed steady exercise on a cycle ergometer at an intensity of 60% maximal O2 uptake (VO2max) for 6 min on three separate occasions while breathing gas mixtures of 12,16 or 21% O2 in N2. Expired gas fractions, ventilation, heart rate, arterial O2 saturation (SaO2), blood lactate (La) and plasma catecholamines (epinephrine: E and norepinephrine: NE) were measured. O2 uptake (VO2) was calculated for the last minute of exercise. Blood samples were drawn at rest and immediately after exercise. By inspiring hypoxic gas mixtures, the SaO2 value decreased during exercise to 85.0 +/- 5.4 (16%) and 66.4 +/- 4.1 (12%) from 95.0 +/- 0.1 in normoxia. VO2 during exercise was not different among the three conditions. Exercise-induced La accumulation was increased by hypoxia. E and NE during exercise were not affected by hypoxia statistically. There was a significant correlation between La and E (P < 0.01) and between La and NE (P < 0.01) during exercise in the three conditions. The present findings suggest a relationship between glycogen metabolism and sympathoadrenal activity which results in an increase of plasma catecholamines during exercise in humans acutely exposed to hypoxia.

Administration, Inhalation↗
PubMed1995

The stimulatory effects of PDGF and TGF-beta 1 on dermal fibroblast attachment.

We investigated the effects of various growth factors (platelet-derived growth factor (PDGF), epidermal growth factor (EGF), basic fibroblast growth factor (bFGF), transforming growth factor-alpha (TGF-alpha), transforming growth factor-beta 1 (TGF-beta 1), tumor necrosis factor-alpha (TNF-alpha), keratinocyte growth factor (KGF)) on fibroblast attachment to plastic plates. It is thought that cell attachment to plastic plates in vitro may represent the step between cell migration and proliferation in vivo during wound healing. Among the growth factors examined, only PDGF and TGF-beta 1 significantly increased fibroblast attachment to both uncoated and collagen-coated plates in a concentration-dependent manner. The addition of anti-PDGF antibody abolished the enhancing effect of PDGF but not that of TGF-beta 1, suggesting that the effect of TGF-beta 1 is not through the autocrine induction of PDGF-related activities secreted by the fibroblasts themselves. These data suggest that PDGF and TGF-beta 1 regulate fibroblast attachment to the suitable environment in the process of dermal wound healing in vivo.

Adult↗
PubMed1995

Distribution of menaquinone-4, a therapeutic agent for osteoporosis, in bone and other tissues of rats.

[14C]Menaquinone-4 was administered orally once daily at a dose of 4 mg/kg for ten days to female rats of different ages to determine its blood and tissue distribution with particular attention to its distribution in bone. Animals aged 10 and 30 months were either ovariectomized or sham-operated as a control, and young rats aged 7 weeks were used as untreated controls. Blood concentrations of radioactivity at 24h after each dose during repeated administration increased daily and approached a steady rate by the seventh dose. Higher concentrations of radioactivity in blood (plasma) were observed in older animals than in the younger ones, but there was little difference between ovariectomized rats (OVX rats) and sham-operated rats (Sham rats). In tissue samples collected at 1.5 h after administration, the liver, adipose tissue, spleen and adrenals showed higher concentrations of radioactivity than the other organs and the plasma. IN bone tissues, the bone marrow (BM) and cancellous tissue (CT) of the femur showed radioactivity concentrations which were higher than that in the plasma, and these increased during repeated administration. Finally, at 24 h after the last dose, the concentrations of radioactivity in bone tissues of older animals (BM, 5,807.2 ng eq/g; CT, 5,264.8 ng eq/g in OVX rats aged 10 months and BM, 11,479.3 ng eq/g; CT, 4,023.0 ng eq/g in OVX rats aged 30 months) were several times higher than those in younger animals (BM, 2,771.6 ng eq/g; CT, 890.2 ng eq/g in 7-week-old untreated rats). The values in OVX rats were also higher than those in Sham rats. Furthermore, micro autoradiography studies of femur sections from OVX rats indicated that [14C] Menaquinone-4 localized in cancellous tissue where bone is known to be actively remodelled. The concentrations of radioactivity in cancellous tissue and bone marrow of OVX rats aged 10 and 30 months were comparable to the pharmacologically effective concentrations of Menaquinone-4 (10(-6)-10(-5) M) in in vitro studies on bone formation. These findings suggest that orally administered Menaquinone-4 distributes specifically into the bone tissues of ovariectomized rats and this is consistent with its effect as a therapeutic agent for osteoporosis.

Aging↗