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Biomedical subjects

H Tamai

Publications and source records attributed to H Tamai.

At least 109 records · Page 6Linked to original sources
PubMed1998

Oxidation products of uric acid and ascorbic acid in preterm infants with chronic lung disease.

Allantoin, the oxidation product of uric acid (UA), can be used as an in vivo marker of free radical generation. The aims of the present study were to evaluate the allantoin changes in plasma and bronchoalveolar lavage fluid (BALF) as well as to examine plasma levels of ascorbic acid (AA) and its oxidation product, dehydroascorbic acid (DHAA), in infants with or without chronic lung disease (CLD) during the first week of life. The study population was 20 infants of 24-30 weeks gestation, comprising 10 who subsequently developed CLD and 10 without CLD. In the CLD infants, the plasma allantoin/UA ratio showed a significant increase after day 1 and continued to increase gradually to reach a peak on day 6 (6.5 +/- 4.1% for CLD and 2.1 +/- 0.9% for non-CLD infants). The allantoin/UA ratio in BALF was also higher in CLD infants and the difference reached significance on days 4-6 (41.2 +/- 15.8% for CLD and 11.7 +/- 9.9% for non-CLD infants). In contrast to allantoin, the plasma DHAA/AA ratio did not differ between the 2 groups throughout the study period. Our findings that the allantoin/UA ratios were significantly higher in CLD than non-CLD infants not only in plasma but also in BALF, and that the intergroup differences of this ratio in both plasma and BALF was more prominent in the latter half of the first week of life further confirm our previous speculation that oxygen radicals are involved in the development of neonatal CLD.

Allantoin↗
PubMed1998

Antioxidant vitamin levels in plasma and low density lipoprotein of obese girls.

To investigate the antioxidant status of obese children, we analyzed beta-carotene and alpha-tocopherol levels in plasma and low density lipoprotein (LDL). We also analyzed the fatty acid composition of LDL as a substrate for oxidative stress. The plasma beta-carotene and alpha-tocopherol levels were relatively lower in obese girls than in normal controls. However, the plasma alpha-tocopherol/lipids ratio was significantly lower in obese girls than in normal controls. Both LDL beta-carotene and LDL alpha-tocopherol levels were significantly lower in obese girls than in normal controls, although no obvious differences were observed in plasma levels. In obese girls LDL contained more polyunsaturated fatty acid (PUFA) compared with normal controls. When the peroxidizability index (PI) was calculated to estimate the susceptibility of lipids to oxidative stress, obese girls had significantly higher PI values than normal controls. Both the LDL beta-carotene/PI ratio and the LDL alpha-tocopherol/PI ratio were significantly lower in obese girls than in normal controls. These results indicate the increased susceptibility of LDL to oxidative stress in obese girls which may promote atherosclerosis later in life.

Adolescent↗
PubMed1998

Effect of alpha-tocopherol status on alpha-tocopherol transfer protein expression and its messenger RNA level in rat liver.

Studies were designed to explore the role of vitamin E nutritional status in regulating the synthesis of alpha-tocopherol transfer protein (alphaTTP) in rat liver. In vitamin E-replete rats, expression of this protein and its specific messenger RNA (mRNA) was decreased by about 300% compared with rats with normal vitamin E levels. In vitamin E-depleted rats, the alphaTTP-specific mRNA level increased to about 150% of that in the normal vitamin E group. However, protein expression remained constant. These findings indicate that the synthesis of alphaTTP can be regulated by the vitamin E nutritional status.

Animals↗
PubMed1998

Plasma beta-carotene, retinol, and alpha-tocopherol levels in relation to glycemic control of children with insulin-dependent diabetes mellitus.

Plasma beta-carotene, alpha-tocopherol and retinol were measured in 15 female and 5 male children with insulin-dependent diabetes mellitus (IDDM), and the correlations with plasma hemoglobin A1c (HbA1c) and fructosamine were analyzed. Twelve female and 8 male children served as age-matched controls. The plasma beta-carotene and alpha-tocopherol levels of the IDDM children were significantly higher than those of the control children, but there were no differences in plasma retinol or total lipid levels. The plasma beta-carotene level, beta-carotene/retinol ratio and beta-carotene/total lipids ratio each showed significant correlations with serum HbA1c and fructosamine in all subjects studied. Similarly, the plasma alpha-tocopherol level and alpha-tocopherol/total lipids ratio were correlated with these indexes of glycemic control. These findings suggest certain mechanisms may exist to prevent lipid peroxidation and vascular complications in IDDM patients.

Adolescent↗
PubMed1998

[A case of acute necrotizing encephalopathy of childhood with a good outcome].

We experienced a case of acute necrotizing encephalopathy of childhood with a good outcome. The disease continued for about three weeks, and the patient recovered with a sequela of mild left-hemiparesis. On the brain magnetic resonance imaging, abnormal intensity areas in the thalamus and putamen reduced size at an early stage of the disease. After 1 year, his mental and motor development seemed to be almost normal, but brain single photon emission computed tomography and electroencephalography were abnormal. Subclinical functional abnormalities persisted longer than had been expected.

Brain↗
PubMed1997

Contemporary percutaneous treatment of unprotected left main coronary stenoses: initial results from a multicenter registry analysis 1994-1996.

BACKGROUND: Coronary artery bypass surgery (CABG) has been considered the therapy of choice for patients with unprotected left main (ULMT) coronary stenoses. Selected single-center reports suggest that the results of percutaneous intervention may now approach those of CABG. METHODS AND RESULTS: To assess the results of percutaneous ULMT treatment from a wide variety of experienced interventional centers, we requested data on consecutive patients treated after January 1, 1994, from 25 centers. One hundred seven patients were identified who were treated either electively (n=91) or for acute myocardial infarction (n=16). Of patients treated electively, 25% were considered inoperable, and 27% were considered high risk for bypass surgery. Primary treatment included stents (50%), directional atherectomy (24%), and balloon angioplasty (20%). Follow-up was 98.8% complete at 15+/-8 months. Results varied considerably, depending on presentation and treatment. For patients with acute myocardial infarction, technical success was achieved in 75%, and survival to hospital discharge was 31%. For elective patients, technical success was achieved in 98.9%, and in-hospital survival was strongly correlated with left ventricular ejection fraction (P=.003). Longer-term event (death, infarction, or bypass surgery) -free survival was correlated with ejection fraction (P<.001) and was inversely related to presentation with progressive or rest angina (P<.001). Surgical candidates with ejection fractions > or = 40% had an in-hospital survival of 98% and a 9-month event-free survival of 86+/-5%, whereas patients with ejection fractions < 40% had 67% and 22+/-12% in-hospital and 9-month event-free survivals, respectively. Nine hospital survivors (10.6%) experienced cardiac death within 6 months of hospital discharge. CONCLUSIONS: While results for selected patients appear promising, until early post-hospital discharge cardiac death can be better understood and minimized, percutaneous revascularization of ULMT stenosis should not be considered an alternative to bypass surgery for most patients. When percutaneous revascularization of ULMT is required, directional atherectomy and stenting appear to be the preferred techniques, and follow-up angiography 6 to 8 weeks after treatment is probably advisable.

Aged↗
PubMed1997

Preparation of Copolymer Particles of Styrene with N-Vinylimidazole-Metal Complexes

The preparation of fine copolymer particles of N-vinylimidazole-metal complexes with styrene by emulsifier-free emulsion polymerization was investigated. Monodisperse spherical particles were formed in low concentrations of monomers. Significant amounts of Co and Ni were introduced into the copolymer particles. The amounts of Co incorporated into the particles are higher than those of Ni.

Journal Article↗
PubMed1997

Effectiveness of tranilast on restenosis after directional coronary atherectomy.

Tranilast is an antiallergic drug used widely in Japan that also inhibits the migration and proliferation of vascular smooth muscle cells. This pilot study was undertaken to determine the effectiveness of tranilast on restenosis after successful directional coronary atherectomy. After the procedure, 40 patients (56 lesions, tranilast group) were treated with oral tranilast for 3 months, and 152 patients (188 lesions, control group) did not receive tranilast. Angiographic and clinical variables were compared between the two groups. The minimal lumen diameter was significantly larger in the tranilast group than in the control group at both 3-month (2.08 vs 1.75 mm, p = 0.004) and 6-month follow-up (2.04 vs 1.70 mm, p = 0.003). The diameter stenosis in the tranilast group was smaller than that in the control group both 3 months (28% vs 40%, p = 0.0007) and 6 months (30% vs 43%, p = 0.0001) after the procedure, with a lower restenosis rate (percent diameter stenosis > or =50) in the tranilast group at 3 months (11 % vs 26%, p = 0.03). The number of clinical events over the 12-month period after the procedure was significantly reduced by tranilast administration (p = 0.013). These findings suggest that the oral administration of tranilast strongly prevents restenosis after directional coronary atherectomy.

Aged↗
PubMed1997

Changes in glomerular epithelial cells induced by FGF2 and FGF2 neutralizing antibody in puromycin aminonucleoside nephropathy.

In the present study, two series of experiments were done with PAN nephropathy rats given fibroblast growth factor 2 (FGF2) or FGF2 neutralizing antibodies. In the first series of experiments, a dose of 10 micrograms of FGF2 (FGF2 group), 40 micrograms of an FGF2 neutralizing antibody (Anti-FGF2 group) or an equal volume of physiological saline (Control group) was administered for four days after PAN injection. Urinary protein increased more in the FGF2 group than in the other two groups. PCNA (+) glomerular cells were found in decreasing order in groups FGF2, Control and Anti-FGF2. Most of the PCNA (+) cells were podocytes and epithelial cells of Bowman's capsule. Staining for desmin, a marker of podocyte injury, was significantly reduced in the Anti-FGF2 group. Glomerular adhesive lesions were found in decreasing order in groups FGF2, Control and Anti-FGF2. The second series of experiments was designed to study the effects of FGF2 neutralizing antibody (40 micrograms for 5 days after PAN injection, in MoAb group) on severely damaged podocytes caused by repeated (two courses) injections in the PAN nephropathy rats. The results were the same as those in series 1. An increase in urinary protein excretion was observed in both groups, but on the 40th day, the level of proteinuria in the MoAb group decreased abruptly. It was observed that the MoAb group had few adhesive glomeruli compared to the IgG group (administration of mouse IgG) and the PCNA (+) epithelial cells of Bowman's capsule were also few. It was supposed that FGF2 would promote the formation of adhesive lesions by stimulating the proliferation of podocytes and epithelial cells of Bowman's capsule. Additionally, FGF2 itself was thought to impair podocytes because of the increasing desmin score and proteinuria.

Animals↗
PubMed1997

Haemodynamic changes during vasodepressor syncope in children and autonomic function.

We investigated postural haemodynamic changes in 24 boys and 30 girls, aged 8-16 years, with orthostatic intolerance. During the orthostatic test, nine boys and seven girls (30%) developed a vasodepressor attack (orthostatic-positive group). The orthostatic-positive group had a more marked increase in heart rate (HR) with slightly lower systolic blood pressure than the orthostatic-negative group during standing, with no significant difference in cardiac output (CO). The shift of blood volume from the intrathoracic region to the lower part of the body determined by electrical impedance and plasma catecholamines on rising were identical in the two groups. At the onset of the vasodepressor attack, CO did not change significantly, indicating that sudden arterial vasodilatation was the cause. In a pharmacological study on autonomic function, higher sensitivity of alpha-adrenoceptor in the resistance vessels was found in the orthostatic-positive group, but there was no significant difference in the basal level of cardiac vagal and sympathetic activity and in cardiac beta-adrenoceptor sensitivity between the two groups. The stepwise regression analysis showed that the magnitude of HR increment during standing was the most useful indicator in predicting the occurrence of a vasodepressor attack. These results suggest that low sympathetic activity in the resistance vessels together with an exaggerated rise in HR during upright posture is strongly associated with vasovagal and vasodepressor attacks in children.

Adolescent↗
PubMed1997

Alterations in lymphocyte subsets and pituitary-adrenal gland-related hormones during fasting.

We investigated changes in the immunoendocrine system during fasting. Ten hospitalized patients aged 14-46 y with psychosomatic disorders fasted for 7 or 10 d. Blood samples were collected before and on days 3 and 7 of the 7-d fasts. When fasting continued to 10 d, an additional sample was taken on day 10. We measured blood cellularity (white blood cells and total lymphocytes), the total number and percentage of lymphocyte subsets (CD2, CD3, CD4, CD8, and CD19), natural killer (NK) cell activity, cytokines (interleukin 1 beta, interleukin 2, interleukin 6, granulocyte-macrophage colony stimulating factor, tumor necrosis factor alpha, and interferon gamma), and soluble interleukin 2 receptors. Corticotropin, cortisol, and dehydroepiandrosterone sulfate (DHEAS) concentrations were also determined. Although the total number of lymphocytes decreased during fasting, NK cell activity increased significantly. Plasma cortisol and DHEAS concentrations also increased significantly whereas changes in corticotropin concentrations were not significant. The total number and percentage of CD4 cells decreased significantly during fasting but no other lymphocyte subsets changed significantly. The percentage of CD4 cells was negatively correlated with cortisol concentrations during fasting. No detectable changes occurred in cytokines or soluble interleukin 2 receptors during the study. All measured immunoendocrine values that changed during fasting returned to prefasting values during the refeeding period. These findings indicate that fasting affects immune variables such as T cell subsets and NK cell activity at least in part through changes in adrenal gland-related hormones.

Adolescent↗
PubMed1997

Trends in neonatal exchange transfusions at Yodogawa Christian Hospital.

A review was conducted to determine the trends in exchange transfusion (ET) of newborn infants at the Yodogawa Christian Hospital during the past 18 years. At that hospital in 1957, the first ET was performed on a term infant with severe hemolytic jaundice caused by rhesus factor (Rh) incompatibility. By 1989, ET had been performed in more than 1400 newborn infants. These cases of newborns who had had ET were retrospectively reviewed, with a focus on every 3 year period from 1974 to 1992. The total number of infants requiring ET noticeably decreased from 68 cases (14.0% of total admissions) in 1974 to 19 cases (6.1% of total admissions) in 1992. (chi 2, P < 0.001) There were three major significant changes in ET during those years. The first was a change in the subjects for ET. The incidence of ET for term infants showed a marked decrease, while the incidence of ET for preterm infants, especially for very low birthweight (VLBW) infants (< 1500 g), noticeably increased. The second was a change in indications for ET. There was a marked decrease in the need for ET as a result of hyperbilirubinemia, while the incidence of ET because of other etiologies, such as septicemia and/or disseminated intravascular coagulopathy, noticeably increased. The third was a change in the technical methods of ET. Now at the Yodogawa Christian Hospital, 100% of the infants are given ET with an automated peripheral two-site method, instead of the Diamond method. Although ET might still be a useful treatment for severe hyperbilirubinemia and other acute problems, the total number of ET noticeably decreased in accord with a decrease in the number of severe hyperbilirubinemia in term newborns. On the other hand, the incidence of ET in preterm infants increased relatively, accompanied by an increase in the survival of VLBW infants. The automated two-site method is the preferred technique for ET at the Yodogawa Christian Hospital, rather than the Diamond method. Further changes in ET might occur in accord with new alternative measures in future.

Christianity↗
PubMed1997

Primary hyperthyroidism induced erythropoietin-resistant anemia?

We describe a 26-year-old male hemodialysis patient with erythropoietin (EPO) resistant anemia associated with primary hyperthyroidism. Use of the anti-hyperthyroid drug, methimazole, led to improvement of his hyperthyroidism and anemia. Before the anti-hyperthyroid therapy, he had received transfusions to maintain an adequate hematocrit during recombinant human EPO therapy. After the therapy, his hyperthyroidism improved and his hematocrit gradually increased without any transfusion. These findings suggest that the patient's EPO resistant anemia was the result of primary hyperthyroidism, and that this complication is reversible if accurate treatment is given.

Adult↗
PubMed1997

Thyroid xenografts from patients with Graves' disease in severe combined immunodeficient mice and NIH-beige-nude-xid mice.

OBJECTIVE: To compare human thyroid xenografts from patients with Graves' disease in severe combined immunodeficient (SCID) mice and triple immunodeficient NIH-beige-nude-xid (NIH-3) mice to obtain an improved animal model for studying these xenografts. DESIGN: Animal study. PARTICIPANTS AND ANIMALS: Patients with Graves' disease; SCID and NIH-3 mice. INTERVENTIONS: Thyroid tissue from six patients with Graves' disease was xenografted to SCID and NIH-3 mice; in addition, peripheral blood mononuclear cells (PBMC) from 12 patients with Graves' disease were grafted intraperitoneally to separate SCID and NIH-3 mice. OUTCOME MEASURES: Levels of human immunoglobulin (IgG), thyroperoxidase antibodies (TPO-Ab), thyroglobulin (Tg-Ab), and expression of thyrocyte intercellular adhesion molecule-1 (ICAM-1) and histocompatibility leukocyte antigen (HLA-DR) in mice after xenografting. RESULTS: IgG was detected in all mice grafted with Graves' thyroid tissue and some mice grafted with PBMC; levels of human IgG peaked 6 to 10 weeks after xenografting. Human IgG levels reached a mean of 500 mg/L (standard error of the mean [SEM] 150 mg/L) in the NIH-3 mice with thyroid xenografts. This was similar to results in SCID mice with thyroid xenografts, which had a mean level of human IgG of 640 mg/L (SEM 230 mg/L). PBMC xenografting resulted in a mean IgG level of 1200 mg/L (SEM 250 mg/L) in NIH-3 mice, which was similar to the mean level of 1000 mg/L (SEM 280 mg/L) in SCID mice. The rate of rise in human IgG in the sera of the NIH-3 mice with thyroid xenografts was similar to that in the SCID mice. TPO-Ab were also detected in some mice with Graves' thyroid grafts and in a few mice injected with PBMC, with levels peaking 4 to 6 weeks after xenografting. TPO-Ab levels reached a mean 109.3 U/mL (SEM 57.2 U/mL) in the NIH mice with thyroid xenografts, which were similar to the mean level of 91.7 U/mL (SEM 34.2 U/mL) in the SCID mice. There were no significant differences in the Tg-Ab levels in each type of mice (13.9 [SEM 12.1] U/mL v. 17.9 [SEM 7.9] U/mL). Eight weeks after xenografting into mice, the expression of xenograft thyrocyte ICAM-1 decreased significantly in both the SCID and NIH-3 mice (from 43.4%, SEM 4.9%, to 35.9%, SEM 4.6%, in the NIH-3 mice, p < 0.05, and from 43.4%. SEM 4.9%, to 32.5%, SEM 5.2%, in the SCID mice, p < 0.05). However, the expression of thyrocyte HLA-DR did not change significantly in the NIH-3 mice (from 11.5%, SEM 3.3%, to 10.8%, SEM 3.3%), whereas it decreased significantly in the SCID mice (from 11.5%, SEM 3.3%, to 4.2%, SEM 2.0%, p < 0.02). CONCLUSIONS: Not only SCID mice but also NIH-3 mice may be useful as animal models for xenografted thyroid tissue, which will help us elucidate the pathogenesis of autoimmune thyroid disease. NIH-3 mice are superior to SCID mice in maintaining the expression of thyrocyte HLA-DR in Graves' thyroid xenografts at levels as high as those before xenografting; this maintenance of expression may be due to the lack of natural killer cells in NIH-3 mice.

Animals↗
PubMed1997

[Aspiration pneumonia during the endotracheal intubation on the occasion of bladder perforation by TUR].

We report on two cases of aspiration pneumonia which developed during the endotracheal intubation after bladder perforation during TUR. The first case was a 79 y.o. male, who underwent TUR-P and lithotripsy under spinal and epidural anesthesia. The second case was a 69 y.o. male, who had undergone TUR-Bt under nitrous oxide-oxygen-enflurane anesthesia. General anesthesia was selected to perform an laparotomy when the diagnosis was made. They vomited a considerable amount of gastric content just after giving the drugs for induction. The chest X-rays revealed signs of aspiration pneumonia. These X-ray findings improved in a week using antibiotic therapy. Although TUR is performed as scheduled, vomiting may occur in the case of unexpected bladder perforation, which can cause aspiration pneumonia. In such emergency, we should insert a nasal tube before induction, press the cricoid (crush induction), or intubate with the patient awake.

Aged↗