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Biomedical subjects

H Tamai

Publications and source records attributed to H Tamai.

At least 91 records · Page 5Linked to original sources
PubMed1999

Comparison of bioelectrical impedance analysis and dual energy X-ray absorptiometry for assessment of body composition in children.

BACKGROUND: There are a variety of methods for assessing body composition. Bioelectrical impedance analysis (BIA) is an easy and non-invasive technique, but has limitations in underweight and overweight subjects. Few reports have investigated the validity of BIA in children. In this report, the characteristics of BIA, especially in overweight and underweight children, are assessed and the results are compared with those of dual energy X-ray absorptiometry (DXA), as a reliable method for assessing body composition. METHODS: Determination of the fat-free mass (FFM), body fat content and percent body fat (%fat) was carried out using both BIA and DXA. The subjects (60 males and 44 females) were divided into five groups according to the percentage of ideal bodyweight (%IBW). Ten obese children, who were treated with exercise and a low-energy diet for 1 month, were also enrolled in this study. RESULTS: The %fat, FFM and body fat content showed a close correlation when measured by BIA and DXA with the correlation coefficients being 0.90, 0.95, and 0.95, respectively. In the underweight group, the %fat value determined by BIA tended to be greater than that determined by DXA, while in the overweight group, the BIA value was lower than the DXA value. The same trend was also seen in obese children before and after therapy with exercise and diet. CONCLUSION: Bioelectrical impedance analysis seems to be a reasonable method for daily clinical use, but attention should be paid to the interpretation of %fat values in underweight and overweight children.

Absorptiometry, Photon↗
PubMed1999

Raised concentrations of aldehyde lipid peroxidation products in premature infants with chronic lung disease.

AIM: To indicate the extent of lipid peroxidation induced by oxidative stress, by measuring aldehyde end products in biological samples. METHODS: A highly specific gas chromatography and mass spectrometry (GC/MS) method was used to measure plasma concentrations of aliphatic aldehydes within the first week of life in 13 premature infants who subsequently developed chronic lung disease (CLD) and 11 infants without CLD (non-CLD). The oxime-tert-butyldimethylsilyl derivatives of aldehydes were analysed using 2,2,6,6-d4-cyclohexanone as the internal standard. RESULTS: All of the aldehydes measured were raised in those infants with CLD compared with non-CLD infants. Plasma concentrations of heptanal, 2-nonenal, and 4-hydroxynonenal (HNE) were significantly increased in CLD infants on the day of birth, while the differences in all aldehydes between the two groups were not significant at 4-6 days of age. Logistic regression analysis showed that the increase in these three aldehydes within the first 24 hours of life independently showed significant associations with the development of CLD. In particular, an HNE concentration of > or = 200 nM on day 0 was the best predictor for the early detection of CLD (odds ratio = 32.0), followed by a 2-nonenal concentration of > or = 150 nM (odds ratio = 16.0). CONCLUSIONS: These findings suggest that lipid peroxidation may have a role in the pathogenesis of neonatal CLD.

Aldehydes↗
PubMed1999

Instantaneous orthostatic hypotension in children and adolescents: a new entity of orthostatic intolerance.

We are the first to report clinical characteristics and circulatory and catecholamine responses to postural change in 44 children with instantaneous orthostatic hypotension (INOH). The symptoms include chronic fatigue, orthostatic dizziness, weakness, sleep disturbance, syncope or near syncope, headache, and loss of appetite. We divided the patients into two groups: group I (30 patients) had either a recovery time for mean arterial pressure of >25 s or a recovery time of >20 s with a 60% or greater decrease in mean arterial pressure at the initial decrease; group II (14 patients) had a prolonged reduction in systolic arterial pressure of > 15% during the later stage of standing (3-7 min) in addition to the criteria for group I. INOH was characterized by a marked reduction in blood pressure at the initial decrease (mean, -55/-27 mm Hg systolic/diastolic). Delayed recovery time of >60 s was found in 21 of 44 patients and orthostatic tachycardia (>35 beats per minute) in 20 of 44. Plasma noradrenaline responses were significantly lower in group I and II than in controls at 1 min of standing and were lower in group II at 5 min of standing. These results suggest that mechanisms responsible for INOH may depend on insufficient sympathetic activation during standing, possibly due to centrally mediated sympathetic inhibition, thus causing impairment of quality of life including school absenteeism. INOH is an important pathologic condition in children with complaints of orthostatic intolerance and can be an unrecognized cause of chronic fatigue. This condition can be identified by using a noninvasive beat-to-beat continuous blood pressure monitoring system.

Adolescent↗
PubMed1999

[Problems of intravenous lidocaine treatment in status epilepticus or clustering seizures in childhood].

Lidocaine was administered intravenously as a substitute for diazepam, to 12 patients with status epilepticus or clustering seizures aged 26 days to 11 years. The medication was very effective in 3 cases with acute convulsions, which disappeared immediately after infusion of lidocaine without relapse. The medication was effective only temporarily in 4 patients; they experienced relapsing seizures during drip infusion of lidocaine intravenously for maintenance. All the relapsing seizures were secondarily generalized ones with diffuse ictal discharges. In 2 cases of localization-related epilepsy, complex partial seizures evolved to secondarily generalized seizures immediately after administration of lidocaine. It must be noticed that in a relatively large number of cases lidocaine is ineffective or even harmful.

Anticonvulsants↗
PubMed1999

Erythrocyte P1 group antigen expression in VTEC-associated hemolytic uremic syndrome.

BACKGROUND: The P1 blood group antigen has been postulated as a protective host factor against the development of the verotoxin-associated with hemolytic uremic syndrome (HUS). PATIENTS AND METHODS: In this study the P1 blood group antigen in 59 Japanese children with a past history of hemorrhagic colitis (HC) was scored with a direct agglutination method using a commercial anti P1 antibody. RESULTS: The P1 antigen was positive in 4 (21.1%) of 19 patients with a history of postdiarrheal HUS and in 11 (28.0%) of 40 patients with no history. There were no significant differences in the frequency of the P1 phenotype between the 2 groups (p = 0.629). CONCLUSION: We concluded that the P1 blood group antigen is not a protective factor against the development of HUS from verotoxin-producing Escherichia coli(VTEC)-infected hemorrhagic colitis in Japanese individuals.

Bacterial Toxins↗
PubMed1999

[A new bite block also serving as an endotracheal tube holder for infants].

We developed a new type of bite block with a combined function as an endotracheal tube (ETT) holder for infants and small children to prevent airway troubles caused by tube kinking, dislodging, extubation and oral membrane trauma. One mm thick plastic plate sized 3.5 x 2 cm was curved to make an open roll. The outer surface of the roll was covered and glued with soft plastic tube (5.0 mm ID endotracheal tube), cut in 3.5 cm length to give an elastic outer surface for the patient's comfort. The rolled ends were diagonally cut to make an oblique slit of 3 mm width. A t-shaped flange made of soft vinyl plate was fixed at a third of the length of the roll to maintain the block's position relative to the lips and to make the fixation of the tube easier. In practical use, after endotracheal intubation is performed as usual, this bite block is put into the mouth and positioned at the oral angle with the flange on the patient's skin. The ETT is fit into the slit of the roll. The skin-facing surface of the flange is pasted to the skin with the double stick material usually used for colostomy stoma. The ETT and the bite block are fixed en bloc with fixing tapes around the mouth. Our bite block has following advantages over other types of bite blocks and tube holders especially for children; 1) the volume of foreign bodies (ETT and bite block) occupying the oral cavity can be reduced and this attenuates the patient's discomfort, 2) good holding of the ETT can prevent its dislodging and decrease the incidence of accidental extubation and 3) suctioning is easier because of wide oral space. The four sizes of the bite block suitable for 4.0, 4.5, 5.0, 5.5 and 6.0 mm ID ETTs are manufactured. We applied this device to several ICU patients and found its use practical and safe.

Child, Preschool↗
PubMed1999

[The linkage of the major histocompatibility complex to autoimmune thyroid diseases].

To investigate the association between human leukocyte antigen (HLA) and development of autoimmune thyroid diseases such as Graves' disease (GD), Hashimoto's thyroiditis (HT), and Graves' disease patients with undetectable TSH-binding inhibitor immunoglobulin (TBII-negative GD), HLA typing was done. 1. We previously reported increased frequencies of HLA-A2 and DPB1*0501 in TBII-positive GD patients, 2. significantly increased frequencies of HLA-A2 and DPB4*0101 in patients with HT, 3. more TBII-negative GD patients having both HLA-B46 and DPB1*0202 than those having each allele alone, suggesting that these 2 alleles may play a synergistic role in controlling the susceptibility to TBII-negative GD, and 4. contrarily that the frequencies of DQA1*0102 in HT patients and of DQB1*0501 in GD patients were significantly decreased, suggesting that DQA1*0102 and DQB1*0501 might confer resistance to the development of HT and GD.

Autoimmune Diseases↗
PubMed1999

[Diabetes and vitamin levels].

The plasma vitamin levels are discussed in association with human diabetic condition. 1) Plasma vitamin B1 level of diabetic patients is revealed in the state of marginal deficiency. 2) Vitamin B6, as the coenzyme pyridoxal phosphate, plays an important role in the metabolism of carbohydrates, therefore B6 has been associated with impairments in gluconeogenesis and abnormal glucose intolerance. 3) Vascular complications of diabetes mellitus, such as atherosclerosis and retinopathy are considered to be related with glycation of low density lipoprotein which induces oxidative injuries to vascular endothelium. Administration of vitamins to diabetic patients reduces insulin requirement and attracts much attention for improvement of vascular complications. Vitamins play as not only nutritional supplements for deficiency, but pharmacological agents for treatment.

Ascorbic Acid↗
PubMed1999

[Substance P].

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Humans↗
PubMed1999

[Allantoin].

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Adolescent↗
PubMed1998

Autonomic function in children with type 1 diabetes mellitus.

We investigated autonomic function in 58 children and young adults with Type 1 diabetes mellitus (aged 7-22 years, duration from 3 to 18, 8.6 +/- 3.4 years) and in 74 healthy controls (6-21 years) using power spectral analysis of blood pressure and heart rate in addition to conventional standard autonomic function tests: deep breathing, the Valsalva manoeuvre, and a standing test. None of the diabetic patients were symptomatic. Reproducibility of the tests was assessed by determining the coefficient of variation in 9 controls (7.8-37.7%). Thirteen per cent of the subjects had difficulty in adequately performing the Valsalva manoeuvre. After adjustment for age, sex, body mass index, and respiratory frequency, results of the Valsalva manoeuvre and deep breathing were not different between patients and controls and there was no significant postural reduction in systolic blood pressure (> or = 20 mmHg) in the patients. Heart rate variation in the supine position during natural breathing was low in patients, although power spectral analysis of heart rate variation did not show a significant decrease in the power density in the high and the low frequency in patients compared to healthy controls. Beat-to-beat blood pressure fluctuation was significantly lower in patients and correlated with metabolic control (mean annual haemoglobin A1c), but not with disease duration and was abnormal in 7 diabetic children (12%). In contrast, tests of vagal activity were not impaired in the patients in this age range. We concluded that vagal involvement in Type 1 diabetic patients determined by spectral analysis of R-R intervals in addition to conventional tests is uncommon, but that beat-to-beat blood pressure variation was more likely to be affected.

Adolescent↗
PubMed1998

Developmental changes in the expression of alpha-tocopherol transfer protein during the neonatal period of rat.

It is well known that the cellular concentration of alpha-tocopherol (alpha-toc) is about 10-fold greater than that of gamma-tocopherol (gamma-toc) despite the ingestion of a large amount of gamma-toc in the diet. Recently, this discrimination of tocopherol is considered to be attributed to alpha-tocopherol transfer protein (alpha-TTP) which binds to alpha-toc in preference to the other forms of tocopherol in the liver. In the present study, developmental changes in expression of alpha-TTP after birth were investigated using rats with respect to plasma changes of tocopherols. The expression of alpha-TTP in the neonatal rat liver, which was very low immediately after birth, increased steadily during the two weeks of life before weanling and reached the adult level at four weeks. During the suckling period, the plasma ratio of alpha-toc to gamma-toc linearly increased, because plasma alpha-toc which was low immediately after birth, increased rapidly during the period, while gamma-toc remained unchanged. The increase in the ratio seemed to correlate with the developmental expression of alpha-TTP in the liver during this period.

Aging↗
PubMed1998

Intramural delivery of a specific tyrosine kinase inhibitor with biodegradable stent suppresses the restenotic changes of the coronary artery in pigs in vivo.

OBJECTIVES: This study was designed to examine whether or not intramural delivery of ST638 (a specific tyrosine kinase inhibitor) with biodegradable stent can suppress the restenotic changes of the coronary artery in vivo. BACKGROUND: Clinical and animal studies demonstrated that restenosis after coronary intervention results from a combined effect of neointimal formation and geometric remodeling (decrease in total cross-sectional area). Thus, the most effective strategy to prevent the restenosis appears to inhibit both the neointimal formation and geometric remodeling by antiproliferative agent and stent, respectively. We have previously shown that ST638 markedly suppresses the restenotic changes of the porcine coronary artery when applied from the adventitial site. METHODS: A poly-L-lactic acid biodegradable stent was coated with either ST638 (0.8 mg) or equimolar of its inactive metabolite, ST494. A pair of these stents were implanted alternatively in the left anterior descending or circumflex coronary artery in pigs (n=6). Three weeks after the procedure, coronary stenosis was assessed by angiography followed by histological examination. RESULTS: Coronary stenosis was significantly less at the ST638 stent site than at the ST494 stent site (47+/-5% vs. 25+/-4%, p < 0.01). Histological examination also showed that the extent of neointimal formation and that of geometric remodeling were significantly less at the ST638 stent site than at the ST494 stent site (p < 0.05). CONCLUSIONS: These results indicate that intramural delivery of a specific tyrosine kinase inhibitor with biodegradable stent overcomes the proliferative stimuli caused by balloon injury, the stent itself, and the drug coating on the stent, resulting in the suppression of the restenotic changes of the coronary artery in vivo. This strategy might also be useful in the clinical setting in humans.

Animals↗
PubMed1998

Tissue distribution of the guinea-pig decay-accelerating factor.

MCA44 is a monoclonal antibody (mAb) to guinea-pig decay-accelerating factor (DAF) and, using this mAb, tissue distribution of guinea-pig DAF was studied by immunofluorescence. Guinea-pig DAF was found to be expressed not only on the vascular endothelium but also on different types of cells, such as the tubular epithelium of the kidney, epidermal cells of the skin and synovial lining cells. As there was no significant reduction in staining intensity with MCA44 following treatment with phosphatidylinositol-specific phospholipase C, many guinea-pig DAF molecules expressed in these tissues may be of the transmembrane form.

Animals↗
PubMed1998

Effect of chronic ethanol feeding on endotoxin-induced hepatic injury: role of adhesion molecules on leukocytes and hepatic sinusoid.

Endotoxin is postulated to be an important aggravating factor for alcoholic liver disease. We have previously reported that rats fed ethanol are more vulnerable to endotoxin-induced liver damage, and hepatic microcirculatory disturbance plays an important role for this liver damage by observation with an intravital microscopy. In this study, we have investigated the role of adhesion molecules in endotoxin-induced microcirculatory disturbance in chronic ethanol-fed rats. Male Wistar rats were pair-fed with ethanol liquid diet (ethanol group) or an isocaloric control diet (control group) for 6 weeks. Leukocyte adherence to the hepatic sinusoid by stimulation with lipopolysaccharides (1 mg/kg of body weight) was observed by an inverted fluorescence microscopy equipped with a silicon-intensified target camera and was found to be enhanced in ethanol-fed rats. Tumor necrosis factor-alpha and GRO/CINC-1 (rat counterpart of interleukin-8) was increased in the blood in these animals. Subsequent expression of adhesion molecules, LFA-1 beta-chain on leukocytes were demonstrated by flow cytometry, which suggests a possible involvement of leukocyte adherence to the hepatic damage in ethanol-fed animals. Preadministration of anti-rat LFA-1 beta-chain monoclonal antibody effectively suppressed leukocyte adherence to the hepatic sinusoid. These results suggest that the enhanced sequestration of neutrophils to the liver with these adhesion molecules may play a significant role in the pathogenesis of alcoholic liver disease.

Alcoholism↗