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Biomedical subjects

T Eguchi

Publications and source records attributed to T Eguchi.

At least 91 records · Page 5Linked to original sources
PubMed1997

Mechanism of beta-adrenergic agonist-induced transmural transport of glucose in rat small intestine. Regulation of phosphorylation of SGLT1 controls the function.

The perfusion of rat small intestine with 10 microM epinephrine (Epi) or 10 microM norepinephrine resulted in significant increases in the amount of 3-O-[methyl-3H]-D-glucose transported from the mucosal to serosal side. The Epi-induced increases in glucose transport were coupled with selective increases in beta-adrenoceptor density in the mucosal membranes. Treatment with 0.1 microM okadaic acid increased glucose transport even in the absence of Epi, but that with 1 microM staurosporine or 60 microM N-[2-(methylamino)ethyl]-5-isoquinoline-sulfonamide dihydrochloride completely inhibited the increases in glucose transport induced by 10 microM Epi or 10 microM dibutyryl cAMP. The maximal binding sites (Bmax) of [3H]phlorizin in brush border membrane (BBM) from tissues perfused with Epi was increased, showing increases in the binding ability of the Na+/glucose cotransporter (SGLT1) to glucose. Phosphorylation and dephosphorylation of BBM with protein kinase A (PKA) and alkaline phosphatase resulted in increases and decreases in Bmax of [3H]phlorizin, respectively. The phosphorylation state of SGLT1 immunoprecipitated from BBM incubated with [gamma-32P]ATP-Mg2+ and PKA, and the analysis of phosphoamino acids composed of SGLT1 in rats given [32P]orthophosphate indicate the presence of potential sites for PKA-mediated phosphorylation of SGLT1 at serine. These findings indicate that the regulation of phosphorylation of SGLT1 leads to an alteration of its function and results in the control of glucose transport in the rat small intestine.

Adrenergic beta-Agonists↗
PubMed1997

Elevated plasma bile acids in hypergalactosaemic neonates: a diagnostic clue to portosystemic shunts.

UNLABELLED: To determine whether plasma levels of total bile acids may provide a useful index for hypergalactosaemia due to porto-systemic shunts, these levels were determined in hypergalactosaemic neonates. Increased levels were found in all cases with portohepatic venous or portocaval shunts. The levels of both total bile acids and galactose were normalized when the shunts disappeared on the echograms. Both bile acids and galactose are almost completely absorbed by the liver via the first portal blood passage. Portosystemic shunts contribute to elevated levels of bile acids and galactose. CONCLUSION: Increased plasma levels of total bile acids serve as a diagnostic clue to the presence of portosystemic shunts in neonates with hypergalactosaemia.

Arteriovenous Malformations↗
PubMed1997

Mechanism for reduction of serum folate by antiepileptic drugs during prolonged therapy.

To determine whether the induction of liver enzymes by antiepileptic drugs play a major role in folate depletion, serum concentrations of folate were measured in age-matched control subjects without anemia and in epileptic outpatients who were being treated with a single antiepileptic drug. Two of the four drugs being administered were enzyme inducers. A protein binding radioassay was used to measure folate levels. Compared with serum folate levels in controls (5.14 +/- 1.88 ng/ml: n = 74), mean serum folate levels were reduced significantly in patients treated with phenobarbitone (3.91 +/- 1.73 ng/ml, p < 0.01: n = 33) and carbamazepine (3.85 +/- 1.02 ng/ml, p < 0.01: n = 36): both of which are enzyme-inducing agents. In contrast, patients treated with the non-enzyme-inducer valproate (5.39 +/- 1.71 ng/ml: n = 41) or zonisamide (5.59 +/- 2.60 ng/ml: n = 25) exhibited serum folate levels that did not differ significantly from values in controls. Findings showed that a reduction in serum folate is associated with the induction of enzymes by antiepileptic drugs. Thus, the induction of microsomal liver enzymes may be critical to the depletion of folate by antiepileptic drugs.

Adolescent↗
PubMed1997

Plasma total homocysteine concentrations in epileptic patients taking anticonvulsants.

Plasma total homocysteine (tHcy) and serum folate (FA) concentrations were measured in 130 epileptic patients taking anticonvulsant drugs. A significant inverse correlation was found between FA and tHcy. This was greater in the older group (> or = 15 years) than in the younger group (1 to 14 years). There were four FA-deficient patients (FA concentration < 3 ng/mL regardless of symptoms), including three patients in the older group and one in the younger group. All FA-deficient patients had received long-term treatment (> 7 years) with multiple anticonvulsants. Their tHcy levels were higher than the 90th percentile of those in control subjects. Two patients showed extremely high levels of tHcy (57.9 and 29.1 mumol/L) and subnormal plasma methionine levels. After FA therapy, their tHcy decreased to levels the same as or less than those of control subjects and FA increased to above the normal range. Based on these findings, we conclude that measuring FA and tHcy concentrations may be useful for preventing thrombosis due to hyperhomocysteinemia in epileptic patients taking anticonvulsants, particularly those who receive long-term treatment with multiple agents.

Adolescent↗
PubMed1997

[The clinical analysis of pediatric meningioma: 5 cases].

Five cases of pediatric meningioma were reported with special emphasis on the clinical features. These cases consisted of three boys and two girls between eight and fifteen years old. Two were falx meningioma, two were suprasellar, and one was petroclival. One falx meningioma was associated with Neurofibromatosis II, and a suprasellar case had no dural attachment, but had cystic component after recurrence. Histologically, there were three meningothelial, one transitional, and one fibrous meningioma. No malignant meningioma was found among any of the cases. Two cases received postoperative irradiation and had no recurrence. A falx meningioma with Neurofibromatosis II and a suprasellar with no dural attachment had evidence of recurrence. The latter suffered from severe neurological deficits after reoperation. It was suggested that irradiation against residual tumor should be considered. However, total removal should be carried out in pediatric cases of meningioma. The authors concluded that our cases had features intermediate between adult meningiomas and pediatric meningiomas because the majority of cases were senior children.

Adolescent↗
PubMed1996

Antidiuretic action of tachykinin NK-3 receptor in the rat paraventricular nucleus.

Studies were performed on the central antidiuretic actions via the tachykinin NK-3 receptor in the rat hypothalamic paraventricular nucleus (PVN). Microinjections of the selective tachykinin NK-3 receptor agonist senktide (2-200 pmol) into the PVN resulted in prolonged inhibition of urine output in water-loaded rats, its effect being dose-dependent. The antidiuretic action of senktide was blocked by pretreatment with the vasopressin V2 receptor antagonist OPC-31260 (1 mg/kg, i.v.), but not by microinjection of the angiotensin II AT-1 receptor antagonist losartan (1 nmol) into the PVN. NK-3 receptor mRNA was strongly detected in the magnocellular part of the PVN and the supraoptic nucleus (SON) of the hypothalamus as detected by in situ hybridization histochemistry. Moreover, [3H]senktide binding sites were also detected in the PVN and the SON by receptor autoradiography. These findings suggest that NK-3 receptors in the PVN may be involved in water regulation by stimulation of vasopressin secretion from the posterior pituitary gland, and that vasopressin caused water reabsorbtion via the kidney V2 receptor.

Angiotensin Receptor Antagonists↗
PubMed1996

Regulation of phosphorylation of Gi2 alpha protein controls the secretory response to isoproterenol in rat parotid tissues.

Treatment of rat parotid tissues with 1 microM isoproterenol (IPR) for 10 min caused a 60% decrease in pertussis toxin (IAP)-catalyzed ADP-ribosylation of Gi alpha and resulted in supersensitivity of amylase secretion from the tissues. However, conversely, IPR treatment for 30 min caused a 40% increase in IAP-catalyzed ADP-ribosylation of Gi alpha, coupled with desensitization of amylase secretion. No changes in Gs function were observed in IPR-induced phenomena. Pretreatment with okadaic acid induced enhancement of the supersensitivity of amylase secretion and disappearance of the desensitization. These phenomena were accompanied with decreases in IAP-catalyzed ADP-ribosylation of Gi alpha. IPR treatment for 30 min caused a 50% decrease in phosphorylation of Gi2 alpha immunoprecipitated with anti-G protein antiserum (AS/7) from [32P]Pi-labeled cells, but such treatment for 10 min caused a 40% increase in phosphorylation in the cells pretreated with okadaic acid. Phosphorylation and dephosphorylation of immunoprecipitates with AS/7 by protein kinase A (PKA) and alkaline phosphatase caused decreases and increases in IAP-catalyzed ADP-ribosylation, respectively, indicating the presence of PKA-mediated phosphorylation sites on Gi2 alpha. Thus, the control of the phosphorylation of Gi2 alpha is of importance and relevance in the regulation of biological processes and cellular responses.

Adenosine Diphosphate Ribose↗
PubMed1996

Study of urinary mandelic acid concentration and peripheral nerve conduction among styrene workers.

The relationship between exposure to styrene and nerve conduction velocities was investigated in 32 workers occupationally exposed to styrene. There was a dose-dependent relationship between urinary mandelic acid and ulnar and peroneal motor distal latencies (MDLs). The ulnar and peroneal MDLs of subgroup B (urinary mandelic acid > or = 250 mg/l) were significantly longer than those of subgroup A (urinary mandelic acid < 250 mg/l)(p < 0.05), and the referent group (p < 0.03). After adjusting confounding factors, urinary mandelic acid had a significant positive relationship with ulnar and peroneal MDL. Our study suggests that a low level of styrene, below the 50 ppm exposure limit of the American Conference of Governmental Industrial Hygienists (ACGIH), involves the risk of inducing adverse effects on the peripheral nervous system. The study also indicated that motor distal latency is a sensitive parameter of toxic peripheral neuropathy.

Action Potentials↗
PubMed1996

Reconstruction of incomplete syndactyly of the toes using both dorsal and plantar flaps.

A new modified method for surgical correction of simple incomplete syndactyly of the toes has been devised. This procedure involves both a dorsal and a plantar skin flap and does not require a skin graft. Reconstruction of syndactyly using only skin flaps situated near the toes almost always results in skin deficiency. Use of a plantar flap from the sole provides sufficient skin for one toe and can be closed primarily. Fourteen cases involving 11 patients have been treated by this method, which is described herein.

Child, Preschool↗
PubMed1996

Investigation on neurotoxicity of occupational exposure to cyclohexane: a neurophysiological study.

OBJECTIVES: To examine the effect of occupational exposure to cyclohexane on the peripheral nervous system. METHODS: A nerve conduction study was performed on 18 workers exposed to cyclohexane in a luggage factory and on age and sex matched occupationally unexposed controls. 12 workers had been exposed to n-hexane (median 2.8 years) before the start of exposure to cyclohexane. To confirm the effect of exposure, a follow up study was performed on nine workers one year after the first study. The mean exposure to cyclohexane was 1.2 years in the first study. A symptom survey was performed. The exposure was measured by air sampling of the breathing zone of each worker. The urinary metabolite cyclohexanol was also monitored. RESULTS: The concentration of airborne cyclohexane ranged from 5 to 211 ppm. The urinary concentration of cyclohexanol ranged from 0.12 to 1.51 mg/l. There was a strong correlation between the cyclohexane exposure in personal air and urinary cyclohexanol. No differences were found in nerve conduction velocities (NCV) between workers exposed to cyclohexane and age and sex matched controls. The results of the follow up study showed significant improvements in peroneal motor NCV (P < 0.01) and sural sensory NCV (P < 0.05) and in ulnar motor distal latency (MDL, P < 0.05) and peroneal MDL (P < 0.05) compared with the first study. Although the past n-hexane exposure affected the first neurophysiological study, the effect had disappeared in the second study, one year later. CONCLUSION: Occupational exposure to the concentrations of cyclohexane experienced in this study had no adverse effects on the peripheral nervous system.

Adult↗
PubMed1996

Cine-magnetic resonance imaging evaluation of communication between middle cranial fossa arachnoid cysts and cisterns.

Cine-magnetic resonance (MR) imaging examinations were performed in 10 patients with middle cranial fossa arachnoid cysts to evaluate communication between the cysts and the normal cerebrospinal fluid (CSF) space. Eight of 10 patients were evaluated by time of flight cine-MR imaging, and two by phase contrast cine-MR imaging. Two patients underwent membranectomy of the cysts, and were evaluated both pre- and postoperatively. Computed tomography cisternography was used to confirm communication between the cysts and the surrounding cisterns. Pulsatile fluid motion within the cysts was present in all patients. However, marked fluid motion and jet flow between the cysts and the surrounding cisterns were only observed in communicating cysts. In the two patients who underwent membranectomy, postoperative examination found greater fluid motion and jet flow not previously present. Cine-MR imaging demonstration of marked pulsatile fluid motion accompanied by jet flow suggests that a cyst communicates with the normal CSF space.

Adult↗
PubMed1996

Eosinophilic granuloma associated with intratumoral hemorrhage--case report.

A 2-year-old boy presented with a rapidly growing soft scalp mass in the left parietal region. Surgical exploration and histological examination demonstrated an eosinophilic granuloma associated with intratumoral hemorrhage. Eosinophilic granuloma should also be considered when a scalp mass lesion exhibits rapid growth.

Cerebral Hemorrhage↗
PubMed1996

[Complex partial status epilepticus in a patient with a frontal cavernous angiomas].

We described a 34-year-old woman with a right frontal cavernous angioma who presented with complex partial status epilepticus (CPSE). In the first CPSE, complex partial seizure with complete unresponsiveness and tonic motor manifestation on her left arm occurred repeatedly at short intervals. Her consciousness was mildly disturbed between the seizures. An hour after the intra-venous administration of diazepam, her consciousness returned to normal. In the second CPSE, no motor manifestation was found, but complete unresponsiveness of short duration accompanied with stare and moderately impaired consciousness continued to occur. We emphasize the importance of not missing this rare non-convulsive epileptic status, especially when it does not present motor manifestations.

Adult↗
PubMed1996

[Effects of age and skin temperature on peripheral nerve conduction velocity--a basic study for nerve conduction velocity measurement in worksite].

The purpose of this study was to investigate the relation between nerve conduction velocity (NCV) and some factors which affect the measurement, such as age, skin temperature, body build and alcohol consumption. Neurophysiological parameters of healthy volunteers (28 males and 27 females, aged 20-57 years) who were free from occupational exposure inducing neuropathy were determined by monitoring skin temperature. A questionnaire survey on height, alcohol and tobacco consumption was also performed. The following results were obtained: 1) Analysis of covariance to examine the relation between age groups and NCVs adjusting for skin temperature showed significant differences only in peroneal motor distal latency (MDL) and duration of sural sensory nerve action potential (SNAP) between age groups. However, there was no constant relation between these parameters and age. Multiple regression analysis showed the significant relationships between age and ulnar MDL and the duration of sural sensory nerve action potential, adjusting for sex, height, weight, BMI, alcohol intake (frequency/week, ethanol equivalent ml/week), tobacco consumption (/day), skin temperature and education years. 2) The skin temperature had significant effects on ulnar MDL, ulnar sensory NCV, duration of ulnar SNAP, sural sensory NCV and amplitude and duration of sural SNAP according to the results of multiple regression analysis and analysis of variance. 3) The body mass index had an independent effect on the ulnar nerve conduction, shortening MDL and the duration of the sensory nerve action potential. 4) Consumption of alcohol and tobacco had no significant relation to nerve conduction velocity in our study. These results show that skin temperature is a major covariate of peripheral nerve conduction and that it is very important to control skin temperature in studies on nerve conduction measurements.

Adult↗
PubMed1996

[Health status, social networks and support systems of so called old old in a population-based comparative study of residents ages 69-74 and 75-80].

To analyze the different features of health status, social support and networks of elderly people by age groups, a survey was performed of the social environment and health related issues among residents aged 69-74 and 75-80, the so called old-old, in Takasu, a small farming town in Hokkaido. The results were as follows: 1. The percentage of elderly having some of the symptoms related to dementia, lower scores of ADL, and poorer conditions of eye sight or hearing were significantly higher among the elderly aged 75-80 compared to those aged 69-74. The prevalence of diseases, such as senile cataracts in both sexes, and heart diseases in men were also higher among those aged 75 and over. 2. Although there were no differences in the mean number of hospital admissions or in the percentage of those having been sick in bed for more than 1 week during the previous one year, both the mean number of out-patient visits and percentage having a family physician were significantly higher in the elderly over 75 than under. Deterioration of IADL were prominent in the item on being able to go far away by themselves. 3. Almost 70% of the elderly participated in community-based social activities in Takasu. There were only small differences in social support and network among the different categories of family structure of the elderly. However women over 75 had statistically significantly lower number of the social supports compared to the younger age groups. A significantly smaller percentage of people was able to obtain the emotional or care support from their spouse for in elderly over 75 than for elderly under 75. 4. The results of this study suggest the need to provide more social support and networks for the old-old over 75 years old who tend to have more diseases and to be in poorer health condition, both physically or mentally than younger old.

Aged↗