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T Miyawaki

Publications and source records attributed to T Miyawaki.

At least 19 recordsLinked to original sources
PubMed2005

Assessment of patients with intellectual disability using the International Classification of Functioning, Disability and Health to evaluate dental treatment tolerability.

BACKGROUND: Patients with serious intellectual disability (ID) are occasionally unable to tolerate dental treatment when intravenous sedation or general anaesthesia (IVS/GA) is involved. In order to make a decision regarding the application of IVS/GA, the International Classification of Functioning, Disability and Health (ICF) is useful. Therefore, in this study, a set of codes involved in dental problems were chosen from the ICF, and patients with ID who could tolerate dental treatments were compared with those who could not. METHODS: From preliminary interviews of six patients with ID, 16 codes were chosen, and an objective five-rank scale was then constructed for use with all chosen codes. Forty-nine ID patients who visited the Okayama University Hospital for dental treatment between January and April 2003 were evaluated. Facility workers were interviewed according to the code set chosen. The participants were then divided into two subgroups depending on their tolerability of dental treatment. The results of these groups for all 16 codes were then compared. RESULTS: Of the 49 patients interviewed, 23 were able to tolerate the dental treatment. In the 'Activities & Participation' section of the ICF, the tolerable group showed lower disability levels with regard to d110 Watching, d540 Dressing and d550 Eating. In other sections, there were no significant differences between the groups. The code set chosen in this study and the five-rank scales in each code were useful as they enabled easy interviewing. CONCLUSIONS: The ICF was raised as a possibility for considering the application of IVS/GA for dental treatment on patients with ID. For clinical use of the ICF, it is recommended that significant codes should be selected and that the five-rank scale is used so that more objective results are obtained from interviews.

Adult↗
PubMed2004

Intravenous sedation for dental patients with intellectual disability.

BACKGROUND: The poor quality of oral health care for people with intellectual disability (ID) has been recognized, and the strong fears about dental treatment suggested as a major reason for disturbances of visits to dentists by such patients. Intravenous sedation is a useful method for relieving the anxiety and fear of such patients about dental treatment, and is frequently essential for ID patients undergoing dental treatment. However, decision regarding the dose of sedative required to be administered for an adequate level of sedation is difficult because the effect of sedation cannot be adequately assessed in patients with severe ID. As an appropriate sedative dose for dental patients with ID has not been fully established, we investigated sedative doses required and the effect of sedation in patients with ID, compared with other dental patients. METHODS: We reviewed the anaesthetic records of dental patients with ID (73 cases) and other dental patients (19 cases) aged between 20 and 29 years who had undergone intravenous sedation with midazolam and propofol in Okayama University Dental Hospital, from January 2000 to December 2000. Intravenous sedation was induced with a bolus intravenous administration of midazolam (2-3 mg) and maintained with a continuous infusion of propofol. The dose of propofol was titrated to achieve an adequate level of sedation: asleep but responding to painful stimulation. The efficacy of sedation, the required doses of propofol, and the wake-up times were investigated for all subjects. The efficacy of sedation was evaluated by judging whether the patient became cooperative and allowed the dental treatment to be carried out or not. The complications induced by intravenous sedation were also evaluated in each subject. Differences in variables between subjects with ID and other subjects were analysed using the Mann-Whitney U-test. RESULTS: Intravenous sedation was effective for dental treatment in all subjects with or without ID. The required dose of propofol in subjects with ID was 4.74 mg/kg/h (2.63-10.33 mg/kg/h), significantly higher than that required for other subjects (3.31, 1.72-4.80 mg/kg/h). Wake-up times of subjects with ID were similar to those of the other subjects. Severe complications were not seen during or after intravenous sedation. CONCLUSION: The results of this study show that intravenous sedation is a useful method for dental patients with ID as well as for other dental patients, but indicate that dental patients with ID need higher doses of sedative to obtain an adequate level of sedation.

Adult↗
PubMed2004

Discordant phenotypic expression of Alport syndrome in monozygotic twins.

BACKGROUND: Alport syndrome is a genetically heterogeneous disorder, but most patients showed the X-linked form resulting from mutations in the COL4A5 gene. A few cases of mosaicism in Alport syndrome have been reported. METHODS: We describe the case of an 8-year-old boy with mosaicism in Alport syndrome. Punch skin biopsies were obtained from the patient's mother and monozygotic twin brother. Five biopsy specimens from non-Alport patients were used as controls. Immunohistochemical analysis was performed using rat monoclonal antibodies towards individual collagen IV(NC) domains. RESULTS: Kidney tissue of the patient showed: mosaic expression of alpha3(IV), alpha4(IV) and alpha5(IV) in the glomerular basement membrane (GBM), distal tubular basement membrane (TBM) and Bowman's capsule; mosaic alpha6(IV) expression in the Bowman's capsule and distal TBM; and well-preserved expression of alpha1(IV) and alpha2(IV). The patient's skin exhibited mosaic alpha5(IV) expression. His mother and monozygotic twin brother disclosed a normal linear staining of alpha5(IV) in their epidermal basement membranes. This unusual mosaicism of alpha3(IV), alpha4(IV), alpha5(IV) and alpha6(IV) is consistent with a pattern of female heterozygotes of Alport syndrome. CONCLUSION: This discordant phenotypic expression of Alport syndrome in monozygotic twins with unaffected parents suggests possible somatic mosaicism in the COL4A5 gene.

Child↗
PubMed2004

Secondary erythrocytosis associated with distal renal tubular acidosis.

AIMS: Diagnosis and classification of renal tubular acidosis (RTA) have traditionally been made on the basis of functional studies. Despite recent expanding knowledge about the molecular abnormalities involved in renal bicarbonate (HCO3-) and H+ transport, the pathophysiology of secondary erythrocytosis in association with distal RTA remains obscure. CASE HISTORY: A 2-month-old boy with severe hyperchloremic metabolic acidosis with positive urine anion gap was diagnosed with distal RTA. Replacement therapy with sodium bicarbonate and potassium citrate succeeded in improving his metabolic acidosis and growth. His renal function remained normal. He had persistent erythrocytosis. CONCLUSION: Secondary erythrocytosis is a rarely reported association of distal RTA. It may increase the risk of thromboembolism.

Acidosis, Renal Tubular↗
PubMed2003

Maintenance of sympathetic tone by a nickel chloride-sensitive mechanism in the rostral ventrolateral medulla of the adult rat.

In urethane-anaesthetised artificially ventilated Sprague-Dawley rats, bilateral microinjection of the divalent cation nickel chloride (Ni(2+); 50 mM, 50 nl) into the rostral ventrolateral medulla elicited a dramatic inhibition of splanchnic sympathetic nerve activity (-44+/-6%) and a marked depressor response (-35+/-7 mmHg). Selective blockade of high-voltage activated Ca(2+) channels with omega-agatoxin IVA (P/Q-type), omega-conotoxin GVIA (N-type) and nifedipine (L-type) did not decrease arterial pressure or splanchnic sympathetic nerve activity when injected separately into the rostral ventrolateral medulla, or combined with kynurenate. Injection of caesium chloride or ZD 7288, a blocker of the hyperpolarization-activated cation current, into the rostral ventrolateral medulla had no effect on arterial pressure or splanchnic sympathetic nerve activity. Bilateral microinjection of nickel chloride into the caudal ventrolateral medulla/pre-Bötzinger complex elicited small increases in splanchnic sympathetic nerve activity (+17+/-13%) and arterial pressure (+12+/-4 mmHg). These were substantially smaller than those evoked by blockade of glutamatergic receptors or high-voltage activated Ca(2+) channels in this area. Injection of kynurenate or high-voltage activated Ca(2+) channel blocker, but not Ni(2+), in this area evoked respiratory termination. The results indicate the existence of a distinct mechanism maintaining the tonic activity of rostral ventrolateral medulla presympathetic neurons that is different from that maintaining the tonic activity in the caudal ventrolateral medulla/pre-Bötzinger region. We conclude that ion channels that are sensitive to Ni(2+), but are insensitive to high-voltage activated (L, P/Q, N) Ca(2+) channel blockers, and are located postsynaptically on the presympathetic rostral ventrolateral medulla neurons are responsible for the tonic activity of the presympathetic neurons in rostral ventrolateral medulla. These channels could well be the low-voltage-activated (or T-type) Ca(2+) channels although other conductances cannot be conclusively excluded.

Age Factors↗
PubMed2003

Developmental changes in interleukin-12-producing ability by monocytes and their relevance to allergic diseases.

BACKGROUND: The T helper type-2 (Th2)-dominated situation can be observed in allergic diseases such as asthma or atopic dermatitis. A reduced ability to produce IL-12, which is a key cytokine for the induction of Th1 responses, has been proposed to lead to aberrant Th2 development in these disease conditions. OBJECTIVE: This study was intended to examine how IL-12-producing ability might associate with allergic diseases as a function of age. METHODS: IL-12 production by monocytes at various ages was assessed in patients with bronchial asthma and/or atopic dermatitis (n = 100) in comparison with non-allergic control subjects (n = 144). Whole blood cells were stimulated with lipopolysaccharide (LPS) after priming with IFN-gamma, then intracellular cytokine expression of IL-12 and IL-8 as a control cytokine of CD14-positive cells was assessed by flow cytometric analysis. RESULTS: In the control subjects, the ability of monocytes to produce IL-12 was negligible at birth and gradually increased with advancing age, whereas IL-8 production was intense throughout the human life. At more than 7 years of age, IL-12 production of patients with allergic diseases was significantly lower compared with that of control subjects. The unexpected finding was that infants and children below 6 years of age with allergic diseases tended to produce more IL-12 compared with age-matched controls. In this young group, it was noted that enhanced IL-12 production by monocytes was especially observed in allergic patients with specific IgE antibodies against some food allergens. Significant inverse relationships between serum IgE levels and IL-12-producing ability were found in the teenage and adult groups, but not in the younger children. CONCLUSION: IL-12 appeared to play different roles in the pathogenesis of allergic diseases between younger and older ages.

Adolescent↗
PubMed2003

Bruton's tyrosine kinase defect in dendritic cells from X-linked agammaglobulinaemia patients does not influence their differentiation, maturation and antigen-presenting cell function.

X-linked agammaglobulinaemia (XLA) is a primary immunodeficiency disease characterized by very low levels or even absence of circulating antibodies. The immunological defect is caused by deletions or mutations of Bruton's tyrosine kinase gene (Btk), whose product is critically involved in the maturation of pre-B lymphocytes into mature B cells. Btk is expressed not only in B lymphocytes but also in cells of the myeloid lineage, including dendritic cells (DC). These cells are professional antigen presenting cells (APC) that play a fundamental role in the induction and regulation of T-cell responses. In this study, we analysed differentiation, maturation, and antigen-presenting function of DC derived from XLA patients (XLA-DC) as compared to DC from age-matched healthy subjects (healthy-DC). We found that XLA-DC normally differentiate from monocyte precursors and mature in response to lipopolysaccharide (LPS) as assessed by de novo expression of CD83, up-regulation of MHC class II, B7.1 and B7.2 molecules as well as interleukin (IL)-12 and IL-10 production. In addition, we demonstrated that LPS stimulated XLA-DC acquire the ability to prime naïve T cells and to polarize them toward a Th1 phenotype, as observed in DC from healthy donors stimulated in the same conditions. In conclusion, these data indicate that Btk defect is not involved in DC differentiation and maturation, and that XLA-DC can act as fully competent antigen presenting cells in T cell-mediated immune responses.

Agammaglobulinaemia Tyrosine Kinase↗
PubMed2003

Defective Fc-, CR1- and CR3-mediated monocyte phagocytosis and chemotaxis in common variable immunodeficiency and X-linked agammaglobulinemia patients.

Blood monocyte phagocytic functions were evaluated by chemotaxis, phagocytosis, and superoxide anion production in nine patients with common variable immunodeficiency (CVI), eight patients with X-linked agammaglobulinemia (XLA), and in 17 normal subjects. Further laboratory diagnosis included the determination of the Bruton's tyrosine kinase (Btk) protein expression in monocytes using flow cytometry. The analysis of monocyte phagocytic function demonstrated that CR3-, CR1-, and Fc-mediated phagocytosis (p = 0.0001) were significantly decreased in CVI and XLA patients, and chemotaxis of monocytes (p = 0.0082) was reduced in XLA patients. Superoxide anion production, however, did not differ between the CVI, XLA, and the control groups. The cytoplasmic expression of Btk protein in monocytes was normal in CVI patients and decreased or not detected in XLA patients. It is proposed that impaired chemotaxis and phagocytosis by monocytes may be a characteristic of the innate immune system in CVI and XLA patients, providing a new direction for the physiopathology of these immunodeficiencies.

Adolescent↗
PubMed2002

Flow cytometric determination of intracytoplasmic Wiskott-Aldrich syndrome protein in peripheral blood lymphocyte subpopulations.

We have produced a novel monoclonal antibody (mAb) directed against Wiskott-Aldrich syndrome protein (WASP) by immunizing mice with the recombinant protein. The mAb designated 5A5 is highly specific to WASP and suitable for Western blot analysis and immunoprecipitation. A flow cytometric assay using the 5A5 mAb identifies expression of intracytoplasmic WASP in lymphocytes from normal individuals. Double staining analysis with cell surface CD3, CD19, and CD56, and intracytoplasmic molecules revealed WASP expression in each subpopulation. With regard to WASP expression in patients with Wiskott-Aldrich syndrome (WAS) and X-linked thrombocytopenia (XLT), peripheral blood mononuclear cells (PBMCs) from nine patients and Epstein-Barr virus-transformed B-lymphoblastoid cell lines from seven patients examined did not show WASP expression by flow cytometric analysis. These results were confirmed by Western blot analysis. We conclude that WASP expression in lymphocyte subpopulations from patients with WAS and XLT can be more precisely evaluated by flow cytometry as compared with Western blot analysis. This flow cytometry method is important as a supplement to Western blots, but even more important as an alternative and powerful assay that can contribute to research on WASP as well as diagnosis in a clinical setting.

Animals↗
PubMed2002

Growth-dependent and species-specific accumulation of polychlorinated biphenyls (PCBs) in tidal flat organisms collected from the Ariake Sea, Japan.

The growth-related as well as species-specific accumulation of polychlorinated biphenyls (PCBs) was studied for tidal flat organisms collected from the Ariake Sea, western Japan. Elevated concentrations of PCBs were found in omnivore fishes, followed in decreasing order by crabs, herbivore fishes, and mussels. This revealed that trophic levels play an important role in PCB accumulation in these organisms. Age- and body length-dependent accumulations of PCBs were observed in herbivorous mudskippers, although a large range of concentrations was found in similar growth stage of fishes. High correlations have been found between concentrations and body length rather than age, which may indicate that the growth rate, which is strongly influenced by the feeding rate of diets, seems to be the predominant factor in determining PCB accumulation. Besides, based on PCB levels in eggs and the whole body in herbivore fishes, the transfer rate of PCBs was estimated to be approximately 10% of female body burdens. Comparison of PCB compositions between eggs and whole body suggests the selective transfer of lower-chlorinated congeners to eggs, which may be due to their instantaneous periods to achieve steady state between egg and whole body lipids. The relationship between BSAFs (biota-sediment accumulation factors) in organisms and log Kow revealed that omnivore mudskipper significantly accumulated PCBs in their body, which might be due to their greater feeding rate and/or higher trophic status in the tidal flat environment.

Animals↗
PubMed2002

Activation of mu-opioid receptors in rat ventrolateral medulla selectively blocks baroreceptor reflexes while activation of delta opioid receptors blocks somato-sympathetic reflexes.

The effects of activation of mu and delta-opioid receptors in the rostral ventrolateral medulla (RVLM) on somato-sympathetic, baroreceptor and chemoreceptor reflexes, as well as respiratory rhythmicity in sympathetic nerves, were examined in urethane anaesthetized (1.1-1.2 g/kg) and artificially ventilated Sprague-Dawley rats. Microinjection of the delta-opioid receptor agonist [D-Pen(2,5)]-enkephalin (DPDPE; 8 mM, 50 nl) bilaterally into the RVLM potently inhibited the post-inspiratory-related burst discharges of lumbar sympathetic nerve activity (LSNA) but had only limited effects on splanchnic sympathetic nerve activity (SSNA) and phrenic nerve discharge. Injection of DPDPE into the RVLM strongly attenuated the somato-sympathetic reflex (approximately 50-80%) evoked in the lumbar sympathetic nerve and splanchnic sympathetic nerve by tibial nerve stimulation but had no effect on baroreceptor reflexes and chemoreceptor reflexes evoked by aortic nerve stimulation and brief hypoxia, respectively. Injection of the mu-opioid receptor agonist, [D-Ala(2),N-Me-Phe(4),Gly-ol(5)]-enkephalin (DAMGO; 4 mM, 50 nl), also elicited a greater inhibition of LSNA than SSNA accompanied by an abolition of phrenic nerve discharge. Injection of DAMGO inhibited the baroreceptor reflex without significant effect on either the somato-sympathetic or the chemoreceptor reflexes. We propose that opioid peptides diminish specific excitatory and inhibitory inputs to the presympathetic neurons in RVLM via distinct presynaptic receptor subclasses.

Action Potentials↗
PubMed2002

Clinical implications of leptin and its potential humoral regulators in long-term low-calorie diet therapy for obese humans.

OBJECTIVE: To address the clinical implications of leptin and to re-examine the relationship between leptin and its potential humoral regulators such as insulin, nonesterified fatty acids (NEFA) and triiodothyronine (T3) in low-calorie diet (LCD) for obese humans. DESIGN: Longitudinal study. SETTING: University and foundation hospitals. SUBJECTS: Ten obese men and 10 premenopausal obese women. INTERVENTIONS: Five men and five women took 800 kcal/day LCD and another five men and five women took 1400 kcal/day balanced deficit diet (BDD) during 4 weeks. RESULTS: Plasma leptin levels in the LCD group decreased more markedly (46.2+/-14.6 to 13.2+/-3.6 ng/ml) than that expected for the decrement in percentage fat (39.0+/-1.7 to 35.9+/-1.7%) and body mass index (BMI; 35.4+/-2.4 to 33.1+/-2.2 kg/m(2)), while that in the BDD group did not decrease significantly (14.9+/-3.5 to 13.4+/-2.8 ng/ml). The ratio of the decrease in leptin levels to that of BMI during the first week was significantly greater than that during the following 3 weeks (39.5+/-2.7 vs 29.3+/-2.1%, P=0.017). The plasma insulin and T3 levels also fell substantially in the first week and continued to decrease during the entire course. Plasma leptin levels measured weekly in each subject were correlated well with insulin (r=0.586, P=0.0003) and T3 (r=0.785, P=0.0004). Multiple regression analyses after adjustment for the time course and BMI revealed that serum levels of T3 were independently correlated with plasma leptin levels (r=0.928, P<0.0001). The plasma NEFA level was markedly elevated during the first 2 weeks and decreased thereafter. CONCLUSIONS: A rapid fall in leptin during the first week of LCD, coordinated by insulin, T3 and NEFA, should be beneficial for responding to decreased energy intake. Inversely, in view of the powerful effect of leptin on energy dissipation, the present findings suggest the potential usefulness of leptin in combination with caloric restriction for the treatment of obesity. SPONSORSHIP: The Ministry of Education, Culture, Sports, Science and Technology of Japan and the Ministry of Health, Labour and Welfare of Japan.

Adolescent↗
PubMed2002

Exercise prescription based upon cardiac vagal activity for middle-aged obese women.

OBJECTIVE: The purposes of this study were to examine a new method to determine exercise intensity for obese people based on the cardiac vagal activity and to determine the effect of this approach on myocardial stress. SUBJECTS: Forty-three middle aged obese female volunteers (age 43.7+/-6.5 y; height 1.56+/-0.05 m; body mass 66.5+/-9.3 kg; body mass index 27.3+/-2.8 kg m(2); percentage body fat 40.7+/-5.9%). MEASUREMENT: In the first experiment, 43 subjects performed a ramp exercise test on a bicycle ergometer with measurement of ECG and gas exchange parameters. In the second experiment, 11 subjects performed 45 min of constant walking exercise on a treadmill at a level corresponding to exercise intensity determined by vagal activity obtained from a ramp bicycle test. Blood pressure, endothelin 1 (ET-1), catecholamine, atrial natriuretic peptide (ANP), and brain natriuretic peptide (BNP) were measured before and after exercise. RESULTS: The heart rate variability power decreased with increasing work rate, and changed little after reaching individual-specific work rate. We presumed that vagal activity disappeared at this point and that the heart rate at this exercise intensity was determined as the vagal activity threshold (T(VA)). The results showed a significant positive correlation (r=0.742, P<0.0001) between T(VA) and ventilatory threshold (VT) heart rates, although the mean heart rate of T(VA) (114.3+/-8.5 beats/min) was significantly lower (P<0.001) than that at VT (119.0+/-11.7), suggesting the cardiac vagal withdrawal occurred prior to the onset of lactate acidosis (lactic acid accumulation). Furthermore, exercise intervention experiment at T(VA) indicated that ET-1, catecholamine and BNP levels were not significantly different before and after exercise. However, ANP levels increased significantly after exercise (pre-exercise 18.6+/-5.38 vs post-exercise 44.0+/-24.87 pg/ml, P<0.001), which in turn brought about a significant post-exercise reduction in the blood pressure (SBP 117.6+/-13.7 vs 110.5+/-7.4 mmHg, P<0.05; DBP 78.6+/-6.7 vs 73.5+/-6.6 mmHg, P<0.01). CONCLUSION: Our data suggest that it is possible to determine the exercise intensity (T(VA)) on the basis of cardiac vagal response. These results also suggest that exercise at T(VA) level is a safe exercise intensity in the light of cardiac stress, and that T(VA) may be recommended for obese people who might possess lower cardiac sympatho-vagal activity.

Adult↗