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Y Itakura

Publications and source records attributed to Y Itakura.

At least 37 records · Page 2Linked to original sources
PubMed1999

[Effect of aged garlic extract (AGE) on hyperglycemia induced by immobilization stress in mice].

The effect of aged garlic extract (AGE) on stress induced hyperglycemia was investigated using the immobilization stress model in mice. After the exposure to immobilization stress for 16 hr per day for 2 consecutive days, the adrenal glands of the mice hypertrophied, and their serum glucose level and corticosterone secretion became elevated, but insulin secretion did not change. These results suggest that the elevation of serum glucose was probably due to the stimulation of the pituitary-adrenocortical axis by the stress. Pretreatment of AGE (5 and 10 ml/kg, p.o.) significantly prevented adrenal hypertrophy, hyperglycemia and elevation of corticosterone, but did not alter serum insulin level. The efficacy of AGE was the same as that of diazepam (5 mg/kg, p.o.). From these results, it is suggested that AGE may prevent stress-induced hyperglycemia, which is the risk of suffering from diabetes mellitus and its progression.

Adrenal Glands↗
PubMed1999

Neonatal lung function in very immature infants with and without RDS.

Some infants, despite being born at low gestations (< 28 weeks gestational age) do not develop RDS and are not surfactant treated. The changes in lung function during the neonatal period in such infants have not been explored, hence it is unknown whether they are similar to those of surfactant treated infants with RDS of similar gestational age. Such data would facilitate assessment of the impact of surfactant administration on the lung function abnormalities of very immature infants with RDS. We, therefore, compared the results of neonatal lung function measurements from immature infants with RDS who received surfactant to those from infants with non-RDS respiratory distress not so treated and matched to the RDS infants for gestational age and within 10% of birthweight. Compliance and functional residual capacity (FRC) were measured daily for the first five days and then at 1, 2 and 4 weeks in 16 infants, median gestational age 27 weeks (range 25-27 weeks). Although exogenous surfactant administration to the immature infants with RDS was associated with improvements in lung function, the non RDS, non surfactant treated infants had both higher compliance (p < 0.05) and lung volumes (p < 0.01) throughout the perinatal period. These results demonstrate surfactant administration does not fully correct the perinatal lung function abnormalities of very immature infants with RDS.

Birth Weight↗
PubMed1999

Functional pulmonary surfactant deficiency and neonatal respiratory disorders.

The pathophysiology of functional deficiency of pulmonary surfactant in the neonatal respiratory disorders represented by MAS, hemorrhagic lung edema and ARDS was discussed. The removal of inhibitor(s) is the cardinal procedure for MAS and the lavage with surfactant solution seems to be promising. In case of replacement therapy, we should consider using a different dose compared to the one used in RDS due to lung immaturity, in order to optimize results.

Humans↗
PubMed1998

Lung volume measurements in infants with and without chronic lung disease.

UNLABELLED: Infants born prematurely who develop chronic lung disease (CLD) have airways obstruction and hence may have low lung volume. The aim of this study was to test that hypothesis and ascertain whether the nature of the comparison control group influenced the results. Sixteen infants who were oxygen dependent for more than 28 days (CLD) and eight infants without CLD had measurements of functional residual capacity (FRC) at 14 and 28 days. The 16 CLD infants consisted of eight less than 27 weeks gestational age (group A) and eight greater than 26 weeks gestational age (group B). The eight infants without CLD (group C) were each matched for gestational age and gender to infants in group B. Group A compared to group C had lower FRCs both at 14 days (median 18 ml/kg vs 27 ml/kg, P < 0.01) and 28 days (median 20 ml/kg vs 26 ml/kg, P < 0.05), but group A differed from group C with respect to both gestational age (P < 0.01) and birth weight (P < 0.01). The FRC results of group B were lower than those of their matched controls (group C) only at 28 days (median 22 vs 26 ml/kg, P < 0.05). Overall, the FRC results at 14 and 28 days correlated significantly with the duration of oxygen and ventilator dependence and weakly with gestational age. CONCLUSION: These results support the hypothesis that FRC results are lower in infants with CLD compared to those without CLD when measured in the neonatal period and emphasize the importance of an appropriate control group. Measurement of lung volume may facilitate assessment of the response to therapies for CLD.

Birth Weight↗
PubMed1998

Novel MEN1 gene mutations in familial multiple endocrine neoplasia type 1.

The recent isolation of the gene responsible for multiple endocrine neoplasia type 1 (MEN 1) has enabled direct genetic diagnosis for people with endocrine tumors and family members of affected patients. Although MEN 1 is rarely recognized in the Japanese population compared to its prevalence in Caucasians, we have previously reported a high prevalence of this disease in a limited area (Nagano Prefecture; population, 2.15 million). In this communication, we report mutations of the MEN1 gene in kindreds living in Nagano Prefecture. The absence of a common mutation among these kindreds indicates that the high prevalence of MEN 1 in this area is not due to a regional accumulation of patients descended from a common ancestor. This result implies that the prevalence of MEN 1 in other areas of Japan could also be higher than had been thought.

Frameshift Mutation↗
PubMed1998

Severe infantile congenital myopathy with nemaline and cytoplasmic bodies: a case report.

A Japanese boy had marked generalized hypotonia and weakness and progressive respiratory failure since birth. Left biceps brachii muscle biopsy at 47 days of age showed marked variation in muscle fiber size, and nemaline and/or cytoplasmic bodies in approximately 10% of the muscle fibers. To our knowledge, the presence of nemaline and cytoplasmic bodies in the same muscle has not been previously reported. The severity of his respiratory failure and muscle weakness were thought to be related to muscle immaturity since there were many undifferentiated type 2C fibers.

Biopsy↗
PubMed1998

Perinatal lung function measurements and prediction of respiratory problems in infancy.

The aim of this study was to determine which lung function test employed in the perinatal period gave the results most significantly associated with respiratory problems in infancy. The ratio of the proportion of time to reach peak tidal expiratory flow to total expiratory time (tPTEF:tE), thoracic gas volume (TGV) and airway resistance (R(aw)) (from which specific conductance (SG(aw)) was calculated) measurements were examined from 85 infants born at or near term. The infants were followed until at least one year of age and described as symptomatic if they wheezed for at least 24 hours. Twenty-three infants were symptomatic in the first year. The symptomatic group, compared to the asymptomatic, had a higher median FRC (p < 0.01) and R(aw) (p < 0.001); their median SG(aw) was lower (p < 0.001). It was possible to obtain tPTEF:tE results from only 61 infants; the median tPTEF:tE did not differ significantly between symptomatic and asymptomatic infants. Logistic regression analysis demonstrated a high R(aw) and FRC, but not a low tPTEF:tE, independently related to positive symptom status. A high R(aw) (>26 cm H2O (1 s(-1))(-1)) was the most sensitive (83%) predictor of subsequent respiratory problems, but all the tests examined had low positive predictive values.

Child↗
PubMed1998

Effect of body position on tidal volume and minute ventilation in very low birthweight infants.

BACKGROUND: To progress the clinical treatment of neonates, especially in the management of respiration, we have to be able to measure their pulmonary function appropriately. Various methods have been developed, but little is known about the pulmonary function of very low birthweight infants (VLBWI) because of the difficulty in taking their measurements with existing equipment. We have developed a very low dead space pneumotachograph to measure lung function in VLBWI. METHODS AND RESULTS: We used our pneumotachograph on 30 infants each weighing less than 1500 g at birth. The infants were intubated with endotracheal tubes of 2.5 or 2.0 mm diameter to measure tidal volume and minute ventilation in the prone and supine position. The tidal volume in the supine position was 6.99 +/- 0.42 mL/kg and 7.58 +/- 0.38 mL/kg in the prone position (mean +/- SE). The tidal volume was significantly larger in the prone than the supine position (P < 0.05). However, no significant difference was observed in minute ventilation and respiratory rates. CONCLUSION: The tidal volume significantly increased in the prone position in VBLWI, confirming the previous observation of larger healthy infants is also applicable to the very low birthweight infants.

Equipment Design↗
PubMed1998

Changes in phenytoin concentrations in blood and cerebrospinal fluid caused by direct hemoperfusion in a patient intoxicated with phenytoin.

We performed direct hemoperfusion (DHP) 5 times on a patient with consciousness disorder and phenytoin intoxication. We then measured the phenytoin concentrations in her cerebrospinal fluid (CSF) and blood at various times. After the first DHP session, consciousness began to improve, and it normalized after the fourth DHP session when the blood concentration of phenytoin had decreased from 54.0 microg/ml to 16.5 microg/ml. The average plasma phenytoin elimination rate of DHP was 18.0% over 120-180 min. The concentration of phenytoin in the CSF decreased as that in the blood was lowered by DHP. The average reduction rate of phenytoin in the CSF after a DHP session was 23.7%, which was similar to the rate of elimination from the blood. The CSF/blood phenytoin ratio was 0.17, and no marked changes were detected before or after a DHP session.

Acute Disease↗
PubMed1998

Mechanisms of protection by S-allylmercaptocysteine against acetaminophen-induced liver injury in mice.

S-Allylmercaptocysteine (SAMC), one of the water-soluble organosulfur compounds in ethanol extracts of garlic (Allium sativum L.), has been shown to protect mice against acetaminophen (APAP)-induced liver injury. In this study, we examined the mechanisms underlying this hepatoprotection. SAMC (100 mg/kg, p.o.) given 2 and 24 hr before APAP administration (500 mg/kg, p.o.) suppressed the plasma alanine aminotransferase activity increases 3 to 12 hr after APAP administration significantly. The hepatic reduced glutathione levels of vehicle-pretreated mice decreased 1 to 6 hr after APAP administration, but SAMC pretreatment suppressed the reductions 1 to 6 hr after APAP administration significantly. These inhibitory effects of SAMC were dose-dependent (50-200 mg/kg) 6 hr after APAP administration. As SAMC pretreatment (50-200 mg/kg) suppressed hepatic cytochrome P450 2E1-dependent N-nitrosodimethylamine demethylase activity significantly in a dose-dependent manner, we suggest that one of its protective mechanisms is inhibition of cytochrome P450 2E1 activity. SAMC pretreatment also suppressed the increase in hepatic lipid peroxidation and the decrease in hepatic reduced coenzyme Q9 (CoQ9H2) levels 6 hr after APAP administration. The hepatic CoQ9H2 content of the SAMC pretreatment group was maintained at the normal level. Therefore, we suggest that another hepatoprotective mechanism of SAMC may be attributable to its antioxidant activity.

Acetaminophen↗
PubMed1998

Eradication of Helicobacter pylori restores elevation of serum gastrin concentrations in patients with end-stage renal disease.

In order to explore the role of Helicobacter pylori (H. pylori) infection in hypergastrinemia in patients on dialysis, the changes in serum gastrin concentration were examined before and after eradication treatment for H. pylori. Twenty-seven patients on dialysis were treated for the eradication of H. pylori. Fasting serum gastrin concentrations were measured by a radioimmunoassay which detects gastrin 17. Ammonia and pH levels of the gastric juice were also measured. The serum gastrin concentrations were significantly decreased following eradication of H. pylori, and the mean value reached the normal range. The restoration of hypergastrinemia was associated with marked reductions of gastric juice ammonia and pH levels. In contrast, patients in whom H. pylori was not eradicated showed no changes in these parameters. In conclusion, the elevation of the fasting serum gastrin 17 concentration seen in dialysis patients appeared to be attributable to H. pylori infection in the stomach.

Ammonia↗
PubMed1998

[Effects of folic acid supplementation on hyperhomocysteinemia in CAPD patients: effects on unsaturated fatty acids].

Hyperhomocysteinemia has been recognized as one of the risk factors for atherosclerosis and premature vascular disease. Patients on dialysis and end-stage renal disease also manifest high plasma concentrations of homocysteine. We performed this study to evaluate the effects of folic acid supplementation on hyperhomocysteinemia in CAPD patients. Twenty-three CAPD patients (8 males, 15 females, 49.1 +/- 14.2-years-old) dialyzed for 22.7 +/- 19.2 months participated in the study. Daily 5-mg doses of folic acid supplementation for 4 weeks significantly reduced plasma concentrations of total homocysteine (p < 0.01) and serine (p < 0.001). This observation suggests that the reduction of plasma concentrations of total homocysteine results from activation of homocysteine remethylation to methionine. On the other hand, folic acid supplementation also revealed significant correlations between changes in serum concentrations of both dihomo-gamma-linolenic acid and arachidonic acid and changes in plasma concentrations of total homocysteine (r = -0.517, p < 0.05, r = -0.451, p < 0.05, respectively). In addition, serum concentrations of both dihomo-gamma-linolenic acid and arachidonic acid in 11 CAPD patients with hyperhomocysteinemia (> or = 35 micromol/litter) were significantly lower than those of 12 CAPD patients with normohomocysteinemia (< 35 micromol/litter) (p < 0.05, p < 0.05, respectively). Serum concentrations of both dihomo-gamma-linolenic acid and arachidonic acid in CAPD patients with hyperhomocysteinemia increased significantly (p < 0.01, p < 0.05, respectively) and reached similar levels of CAPD patients with normohomocysteinemia, while plasma concentrations of total homocysteine decreased after folic acid supplementation. These findings suggest that correction of hyperhomocysteinemia in patients on dialysis produces an increase in unsaturated fatty acids.

Administration, Oral↗
PubMed1997

Brain-derived neurotrophic factor reduces blood glucose level in obese diabetic mice but not in normal mice.

Brain-derived neurotrophic factor (BDNF) is a member of the neurotrophin family. However, it is not yet known if BDNF works on the endocrine system itself. Here we report that BDNF improves hyperglycemia in obese diabetic animals. BDNF reduced the blood glucose level in obese db/db diabetic mice in which the effect of BDNF was age-dependent and high under the condition of hyperinsulinemia, while BDNF showed no effect on non-diabetic db/m mice. These results suggest that BDNF ameliorates insulin resistance by enhancing insulin action in peripheral tissues. Furthermore, BDNF was found to reduce the plasma insulin level in db/db mice. Among the neurotrophin family, NT-3 also reduced the blood glucose level in db/db mice. These results provide a novel insight that neurotrophin functions on the endocrine system as well as the nervous system.

Animals↗
PubMed1997

Allixin, a phytoalexin produced by garlic, and its analogues as novel exogenous substances with neurotrophic activity.

Effects of allixin, a phytoalexin of garlic, and its analogues were studied on the survival and morphology of primary cultured neurons from fetal rat brain. Addition of allixin (1-100 ng/ml) to medium significantly promoted the survival of neurons derived from various regions of brain and increased the number of branching points per axon in hippocampal neurons. Allixin, however, was cytotoxic at higher concentrations (>1 microg/ml). Among the analogues of allixin, 2,6-dimethyl-3-hydroxy-4H-pyran-4-one (DHP) possessed potent neurotrophic activity at concentrations over 10 ng/ml without any obvious cytotoxicity up to 10 microg/ml. DHP also retained the activity to promote axonal branching. These results indicate that DHP is a novel exogenous low molecular weight neurotrophic substance without apparent cytotoxicity. This compound may be a useful prototype leading chemical for developing therapeutic and/or prophylactic drugs for neurodegenerative disorders.

Animals↗
PubMed1997

Neurotrophic activity of organosulfur compounds having a thioallyl group on cultured rat hippocampal neurons.

Several organosulfur compounds found in garlic extract promoted the survival of rat hippocampal neurons in vitro. From the analysis of structure-activity relationship, thioallyl group in these compounds is essential for the manifestation of neurotrophic activity. S-Allyl-L-cysteine (SAC), one of the organosulfur compounds having thioallyl group in garlic extract, also promoted the axonal branching of cultured neurons. These results suggest that thioallyl compounds make a unique group of neurotrophic factors.

Animals↗
PubMed1997

Multiple endocrine neoplasia type 1 is not rare in Japan.

Multiple endocrine neoplasia type 1 (MEN 1) is rarely reported in Japanese and other oriental populations. To examine if there is a racial difference in the prevalence of MEN 1, we initiated extensive work on patients with endocrine tumors for additional lesions, and annual screening of family members of affected patients. In a four-year study, eleven asymptomatic patients were found by family screening, and the number of patients with MEN 1 in our clinics increased from 16 to 38. Estimated prevalence of MEN 1 was no less than 0.018/1000. MEN 1 may not be as rare as had been thought in Japanese, and the prevalence of MEN 1 in Japanese would not be significantly different from that of Caucasians. Systemic surveillance and extensive screening of family members are required for early detection and management of patients.

Adolescent↗