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Biomedical subjects

T Kawakita

Publications and source records attributed to T Kawakita.

At least 19 recordsLinked to original sources

Factors responsible for glucose intolerance in Japanese subjects with impaired fasting glucose.

Impaired fasting glucose (IFG) represents risk of development of diabetes (DM) and its complications. We investigated insulin secretion and insulin sensitivity in 403 IFG subjects divided into three levels of 2-hour postchallenge glucose (2-h PG) to clarify the factors responsible in the development of glucose intolerance in Japanese IFG. Nearly 60% of the subjects at annual medical check-up with FPG of 6.1-7.0 mmol/l at the first screening were diagnosed by 75 g oral glucose tolerance test (OGTT) to have impaired glucose tolerance (IGT; FPG <7.0 mmol/l and 7.8 mmol/l <2-h PG <11.1 mmol/l) or DM (isolated postchallenge hyperglycemia (IPH); FPG <7.0 mmol/l and 11.1 mmol/l <2-h PG level). The primary factor in the decreased glucose tolerance was a decrease in early-phase insulin, with some contribution of increasing insulin resistance. In addition, IFG/IGT and IFG/IPH subjects showed a compensatory increase in basal insulin secretion sufficient to keep FPG levels within the non-diabetic range. IFG is composed of three different categories in basal, early-phase insulin secretion, and insulin sensitivity.

Asian People↗

No effect of a traditional Chinese medicine, Hochu-ekki-to, on antibody titer after influenza vaccination in man: a randomized, placebo-controlled, double-blind trial.

BACKGROUND: It was shown that a traditional Chinese medicine, Hochu-ekki-to (HET), had adjuvant effects in influenza vaccination in an animal experiment. This, however, could not be assessed in a clinical study. METHODS: Thirty-two healthy subjects were randomly assigned to two groups (control and HET groups) in a double-blind manner. HET subjects (n=17) took 7.5 g of HET/day for two weeks; control subjects took the same amount of indistinguishable placebo. Then subjects were vaccinated against influenza (H1N1, H3N2 and B/Shandong). Hemagglutinin titers and natural killer (NK) activity were measured at weeks 0, 1, 2, 4, and 12. RESULTS: Antiinfluenza titers against the three viruses were increased continuously for the first two weeks and leveled off. However, there were no significant differences in any titers between the two groups. NK activity peaked at week 2 without any inter-group differences. CONCLUSION: We could not find any adjuvant effects of HET in this experimental condition.

Adjuvants, Immunologic↗

Plasma ghrelin levels in healthy elderly volunteers: the levels of acylated ghrelin in elderly females correlate positively with serum IGF-I levels and bowel movement frequency and negatively with systolic blood pressure.

Aging is associated with a decrease in growth hormone (GH) secretion, appetite and energy intake. As ghrelin stimulates both GH secretion and appetite, reductions in ghrelin levels may be involved in the reductions in GH secretion and appetite observed in the elderly. However, only preliminary studies have been performed on the role of ghrelin in elderly subjects. In this study, we sought to clarify the physiologic implications of the age-related alterations in ghrelin secretion by determining plasma ghrelin levels and other clinical parameters in healthy elderly subjects. Subjects were > or = 65 years old, corresponding to the SENIEUR protocol, had not had a resection of the upper gastrointestinal tract and had not been treated with hormones. One hundred and five volunteers (49 men and 56 women) were admitted to this study (73.4 +/- 6.3 years old). Plasma levels of acylated ghrelin in elderly female subjects positively correlated with serum IGF-I levels and bowel movement frequency and negatively with systolic blood pressure. In elderly men, desacyl ghrelin levels correlated only weakly with bowel movement frequency. These findings suggest that the plasma levels of the acylated form of ghrelin may influence the age-related alterations in GH/IGF-I regulation, blood pressure and bowel motility. These observational associations warrant further experimental studies to clarify the physiologic significance of these effects.

Acylation↗

Mutations in the receptor tyrosine kinase pathway are associated with clinical outcome in patients with acute myeloblastic leukemia harboring t(8;21)(q22;q22).

AML1-MTG8 generated by t(8;21) contributes to leukemic transformation, but additional events are required for full leukemogenesis. We examined whether mutations in the receptor tyrosine kinase (RTK) pathway could be the genetic events that cause acute myeloblastic leukemia (AML) harboring t(8;21). Mutations in the second tyrosine kinase domain, juxtamembrane (JM) domain and exon 8 of the C-KIT gene were observed in 10, one and three of 37 AML patients with t(8;21), respectively. Three patients showed an internal tandem duplication in the JM domain of the FLT3 gene. One patient had a mutation in the K-Ras gene at codon 12. As the occurrence of these mutations was mutually exclusive, a total of 18 (49%) patients showed mutations in the RTK pathway. These results suggest that activating mutations in the RTK pathway play a role in part as an additional event leading to the development of t(8;21) AML. The 6-year cumulative incidence of relapse in patients with RTK pathway mutations was 79.8%, compared with 13.5% in patients lacking such mutations (P=0.0029). Furthermore, the 6-year relapse-free survival in patients with mutations was 18% compared to 60% in those without mutations (P=0.0340), indicating that RTK mutations are associated with the clinical outcome in t(8;21) AML.

Adolescent↗

Clinical characteristics of conjunctivochalasis with or without aqueous tear deficiency.

AIM: To show characteristic ocular surface findings caused by conjunctivochalasis (CCh) in dry eye patients with or without aqueous tear deficiency (ATD). DESIGN: Comparative non-interventional cases. PATIENTS AND METHODS: Clinical data of five ATD patients without CCh (group A), eight CCh patients with ATD (group B), and eight CCh patients without ATD (group C) were retrospectively reviewed. Presence or absence of CCh was determined by fluorescein staining to outline tear meniscus and conjunctival folds with an enhancing filter. Dry eye symptoms, history of subconjunctival haemorrhage, meibum expression, tear break up time, fluorescein and rose bengal staining, and fluorescein clearance test, and other abnormal ocular surface findings were measured. RESULTS: CCh patients were significantly older (p = 0.001). In pure ATD, the principal symptom of dryness became worse as the day progressed. In contrast, blurry vision, burning sensation, and dryness became worse during reading in all CCh patients (p = 0.0008) or worse in the morning upon awakening in the majority patients with CCh only (p = 0.02). Besides the interpalpebral exposure, which was noted in ATD, positive fluorescein or rose bengal staining was noted in the redundant conjunctival folds and the non-exposure zone in CCh (p = 0.0008). Redundant conjunctival folds were present in both lower and upper bulbar conjunctiva, obliterating both lower and upper tear meniscuses, and spatially correlated with anterior migration of the mucocutaneous junction in CCh. Delayed tear clearance was significantly more prevalent in CCh than ATD (p = 0.0008). Vigorous blinking worsened in CCh but not in ATD (p = 0.0008). Lacrimal puncta were swollen in groups B and C, but not in group A (p = 0.04). CONCLUSIONS: CCh is not restricted to the lower bulbar conjunctiva, and contributes to pathogenesis of dry eye by obliterating both lower and upper tear meniscus, causing unstable tear film and by creating delayed tear clearance. Dry eye symptoms were worsened by downgaze during reading and by vigorous blinking. Other characteristic signs including subconjunctival haemorrhage, swollen puncta, anterior migration of the mucocutaneous junction, and patterns of dye staining also help distinguish dry eye associated with CCh from that caused by ATD alone.

Adult↗

Characterization of itch-associated responses of NC mice with mite-induced chronic dermatitis.

To clarify the behavioral and pathological features of spontaneous scratching of NC mice with mite-induced chronic dermatitis, we investigated the spontaneous and pruritogen-evoked scratching of NC mice. Although the frequency of scratching of NC mouse did not increase under specific pathogen-free environment, it gradually and markedly increased from 3 to 6 weeks after transfer to conventional environment. The onset of increase in spontaneous scratching was similar to that of dermatitis development and the elevation of plasma concentration of immunoglobulin E. At chronic stage (16 weeks after environment change), the frequency of spontaneous scratching was roughly parallel to the degree of dermatitis, but not to the plasma concentration of immunoglobulin E. The spontaneous scratching of NC mice with dermatitis was inhibited by distraction and the opioid antagonist naltrexone, suggesting that the scratching is itch-associated response. An intradermal injection of serotonin, but not histamine and substance P, elicited scratching of the injected site. Methysergide and cyproheptadine inhibited the serotonin-induced scratching but not spontaneous scratching. The results suggest that marked elevation of plasma immunoglobulin E is not always the cause of spontaneous itch-associated response of NC mice with dermatitis. Serotonin, histamine and substance P may not play an important role in spontaneous itch-scratch response at a chronic stage.

Animals↗

Development of the susceptibility to oral tolerance induction in infant mice administered a herbal drug, Hochu-ekki-to (Bu-Zhong-Yi-Qi-Tang).

The susceptibility to oral tolerance in post-neonatal infant mice and the effect of a herbal drug, Hochu-ekki-to (HOT), on the susceptibility were investigated. To induce oral tolerance induction, infant and adult mice at 4 and 8 weeks of age, respectively, were orally administered a single high dose of OVA before an intraperitoneal immunization with OVA adsorbed on aluminum hydroxide. HOT (1000 mg/kg) was administered orally for 7 days before the induction. HOT significantly decreased the serum levels of OVA-specific IgE and IgG1 and the antigen-specific proliferation of spleen cells in infant mice, both of which were greatly enhanced compared to in adult mice. HOT increased the number of both CD4+ T cells and antigen-presenting cells expressing MHC class II as well as costimulatory molecules (CD40, CD80 and/or CD86) in the Peyer's patch (PP) of infant mice, which had fewer cells than adult mice. In the PP, moreover, HOT augmented the IL-12p40 mRNA expression and spontaneous or CD40-stimulated IL-12 production, and increased the number of CD4+ cells expressing CD40 ligand, which is up regulated by IL-12. These results suggest that HOT increases the number and improves the function of PP cells that are fully susceptible to the induction of oral tolerance.

Adjuvants, Immunologic↗

Immunomodulating effect of a traditional Japanese medicine, hachimi-jio-gan (ba-wei-di-huang-wan), on Th1 predominance in autoimmune MRL/MP-lpr/lpr mice.

Hachimi-jio-gan (Ba-Wei-Di-Huang-Wan, HMG), a traditional Japanese herbal medicine, has been used for disorders accompanying aging. Oral administration of HMG from 8 to 16 weeks of age to MRL/lpr mice as a lupus-like autoimmune model ameliorated significantly some nephritis parameters, proteinuria and immune complex deposition in the kidney. Further, HMG reduced significantly the degree of lymphadenopathy and the serum level of immunoglobulin (Ig) G2a anti-dsDNA specific auto-antibody, even at 12 weeks of age. Simultaneously, interferon (IFN)-gamma production from anti-CD3 stimulated B220- T cells was suppressed by HMG, whereas interleukin (IL)-4 production was promoted. Examination of cytokine mRNA expressions in CD4 positive cells showed clearly that T cell differentiation was shifted from T helper (Th)1 to Th2 predominance by HMG. Furthermore, we demonstrated that HMG suppressed IL-12 mRNA expression in spleen cells which is a marker of Th1 predominance in MRL/lpr mice. These results suggested that HMG modulated an imbalance toward Th1 predominance in MRL/lpr mice through inhibition of IL-12 production and ameliorated autoimmune disorders.

Adjuvants, Immunologic↗

Dichotomous effect of a traditional Japanese medicine, bu-zhong-yi-qi-tang on allergic asthma in mice.

To determine the potentiality of prophylactic and/or therapeutic approaches using a traditional herbal medicine, Bu-zhong-yi-qi-tang (Japanese name: Hochu-ekki-to, HOT), for the control of allergic disease, we examined the effects of oral administration of HOT on a murine model of asthma allergic responses. When oral administration of HOT was begun at the induction phase immediately after OVA sensitization, eosinophilia and Th2-type cytokine production in the airway were reduced in OVA-sensitized mice following OVA inhalation. The serum levels of OVA-specific immunoglobulin (Ig)E and IgG1 were significantly decreased, whereas the level of OVA-specific IgG2a was increased. Interleukin (IL)-4 production by spleen T cells in response to OVA was significantly suppressed, while Interferon (IFN)-gamma production was increased in mice treated with HOT in the induction phase. On the other hand, HOT given in the eliciting phase induced a predominant Th2 response with increased IgE production in OVA-sensitized mice following OVA inhalation. These results suggest that the oral administration of HOT dichotomously modulates allergic inflammation in a murine model for asthma, thus offering a different approach for the treatment of allergic disorders.

Administration, Oral↗

Protective effect of a traditional Japanese medicine Hochu-ekki-to (Chinese name: Bu-zhong-yi-qi-tang), on the susceptibility against Listeria monocytogenes in infant mice.

In this study, the effect of traditional Japanese (Chinese) medicine, Hochu-ekki-to, HOT (Chinese name: Bu-zhong-yi-qi-tang), on the susceptibility against Listeria monocytogenes in postneonatal infant mice was examined. Numbers of bacteria in infant mice (infected at 4 weeks of age) were significantly higher than those in adult mice (infected at 8 weeks of age) on day 3 (non-specific resistance phase) and day 5 (specific resistance phase) after infection. Oral administration of 1,000 mg/kg of HOT for 7 days to infant mice reduced bacterial numbers in the liver and spleen at 5 days after the infection. The amount of IFN-gamma and the number of IFN-gamma-producing CD4+ T cells were lower in infant mice than adult mice but those in infant mice enhanced by HOT treatment. HOT also enhanced the antigen-presenting function along with the expression of MHC class II in infant macrophages induced by heat-killed L. monocytogenes. Further, HOT enhanced the IFN-gamma production from infant CD4+ T cells independent of the deficiency in the antigen-presenting function. These findings suggest that HOT induced simultaneously functional maturation of both infant antigen-presenting cells and T cells, and consequently developed an anti-listerial Th1 response.

Animals↗

Protective effect of a traditional Japanese medicine, Bu-zhong-yi-qi-tang (Japanese name: Hochu-ekki-to), on the restraint stress-induced susceptibility against Listeria monocytogenes.

In this study, the effect of traditional Japanese (Chinese) medicine, Bu-zhong-yi-qi-tang (Japanese name: Hochu-ekki-to, HOT), on the restraint stress treatment (RST)-induced susceptibility against Listeria monocytogenes (L. monocytogenes) was examined. When RST was performed every day for 10 h from the day of infection, the bacterial numbers were increased at 3 and 5 days after the infection. Oral pretreatment with HOT for 7 days prevented such increases. Pretreatment with HOT prevented the suppression of antigen-specific IFN-gamma production by RST. HOT also prevented suppression of macrophage accumulation, including MHC-class II positives, in the peritoneal cavity and their bactericidal activity by RST. HOT suppressed the serum corticosterone level elevated by RST in infected mice. Taken together, the suppression of corticosterone using HOT participates in the prevention of suppressions of the bactericidal activity of macrophages, migration of macrophages and antigen-specific IFN-gamma production of Th1 cells by RST. Our findings suggest that HOT is a useful drug for patients suffering from stress disease to reduce the susceptibility to bacterial infection.

Animals↗

Body sway induced by depth linear vection in reference to central and peripheral visual field.

PURPOSE: A significant correlation between the magnitude of linear vection and the degree of body sway induced by a visual stimulus perceived as moving in depth was previously described (Jpn J Physiol 49: 417-424, 1999). The purpose of this study was to examine the role of the central and peripheral visual fields in inducing vection and body sway. METHODS: Ten healthy volunteer students who had no vestibular or neurological disorders served as subjects. A depth optokinetic stimulus (DOKS) was projected onto a head-mounted display (HMD) and was perceived to move in depth. Different amounts of the central or peripheral visual field were masked independently. The magnitude of the linear vection induced by the DOKS was evaluated by verbal assessment and compared with the magnitude of induced body sway. Body sway was monitored by a video-motion-analyzer that recorded the movement of the head, shoulder, hip, knee and ankle. RESULTS: The magnitude of vection was correlated with the frequency of DOKS and also with the amplitude of body sway (r = 0.74). When the central visual field was restricted by 10 to 30%, there was almost no change in the induced body sway and vection. However, when central occlusion was greater than 40%, depth perception and induced body movement were greatly reduced. With increasing amounts of peripheral field occlusion from 50 to 90%, there was a greater reduction of both vection and body sway. CONCLUSION: Vection is strongly correlated with body movement, and vection and body sway were more dependent on stimulation of the peripheral visual field.

Adult↗

Synthesis and pharmacological evaluation of carboxamide derivatives as selective serotoninergic 5-HT(4) receptor agonists.

A number of new carboxamide derivatives were synthesized. The affinity of these compounds for the serotoninergic 5-HT(4) receptor was evaluated by use of radioligand-binding techniques. The agonistic activity was evaluated as the contractile effect of the ascending colon isolated from guinea-pigs. Among these compounds, 4-amino-5-chloro-2-methoxy-N-[1-[2-[(methylsulfonyl)amino]ethly]-4-piperidinylmethyl]benzamide (24) showed a high affinity for the 5-HT(4) receptor (Ki = 9.6 nM). Compound 24 displayed a higher affinity for 5-HT(4) receptors than the other receptors, including, 5-HT(3) and dopamine D(2) receptors. In addition, compound 24 was confirmed to be a potent 5-HT(4) receptor agonist (ED(50) = 7.0 nM). An interaction model between compound 24 and 5-HT(4) receptor was proposed.

Journal Article↗

Accelerated recovery from cyclophosphamide-induced leukopenia in mice administered a Japanese ethical herbal drug, Hochu-ekki-to.

The effect of a Japanese ethical herbal drug, Hochu-ekki-to (HOT), on recovery from leukopenia induced by cyclophosphamide (CY) was investigated. Daily oral administration of 1000 mg/kg HOT into CY-treated mice significantly prevented decrease of leukocyte numbers in the peripheral blood and accelerated recovery from leukopenia. Ginsenoside Rgl extracted from Ginseng radix, a major herb of HOT, was one of the active ingredients. HOT increased numbers of neutrophils and monocytes in the peripheral blood compared with CY-treated control. Moreover, HOT augmented the resistance against Pseudomonas aeruginosa infection. The number of colony-forming units in the spleen (CFU-S) also increased in HOT-treated mice. The frequencies of IL-3-, GM-CSF- and IFN-gamma-producing cells increased in the spleen, bone marrow, liver and IEL on HOT treatment, and HOT clearly augmented the expressions of IL-3, GM-CSF and IFN-gamma mRNA in the spleen, bone marrow, liver and IEL except IL-3 and IFN-gamma mRNA in the IEL. These results suggest that HOT enhances the production of hematopoietic lymphokines, stimulates the proliferation of hematopoietic progenitor cells and consequently accelerates recovery from leukopenia in CY-treated mice. Additionally, IFN-gamma which HOT-augmented the production may contribute the protective effect against the bacterial infection by activating of phagocyte cells.

Animals↗