Biomedical subjects

Y Inoue

Publications and source records attributed to Y Inoue.

At least 739 records · Page 41Linked to original sources

PubMed1997

Malposition of the tibial tubercle during flexion in knees with patellofemoral arthritis.

OBJECTIVE: To assess the mechanisms contributing to the induction of patellofemoral arthritis (PF-OA). DESIGN AND PATIENTS: A computed tomography scan was taken at three levels of the lower extremity in full extension and at 30 degrees of flexion. The cuts were superimposed and 12 parameters were compared in 17 PF-OA knees and 27 normal knees to assess the rotation angle of the tibial tubercle. RESULTS: Although the tibial tubercle was in almost the same position in full extension in the normal and PF-OA knees, it was positioned significantly laterally at 30 degrees of flexion in PF-OA knees. Also the articular surface of the lateral femoral condyle was significantly narrower or steeper in PF-OA knees. CONCLUSION: Anatomic variations and mechanical abnormalities were identified in the PF-OA knees.

Adult↗

PubMed1997

Effect of deadtime loss on quantitative measurement of cerebral blood flow with technetium-99m hexamethylpropylene amine oxime.

Deadtime count loss may cause error in quantitative measurements with a gamma camera. We evaluated the effect of deadtime loss on the measurement of cerebral blood flow (CBF). Radionuclide angiography with technetium-99m hexamethylpropylene amine oxime (99mTc-HMPAO) was performed in 20 patients. A reference source was placed on the periphery of the detector to monitor deadtime loss, and CBF was calculated based on the data of radionuclide angiography with and without deadtime correction. In ten patients injected with 1110 MBq of the tracer, the CBF value without correction was 9.9%+/-1.8% higher than that with correction. This shows that deadtime loss may cause significant overestimation. The difference between CBF values obtained with and without correction was smaller in ten patients with an injected dose of 370 MBq (3.0%+/-1.2%). These results suggest a substantial effect of deadtime loss on CBF as measured by radionuclide angiography and 99mTc-HMPAO.

Adolescent↗

PubMed1997

Monoclonal antibodies against glutaraldehyde-conjugated histamine: application to immunocytochemistry.

We have developed mouse monoclonal antibodies (AHA-1-5, all IgG1 sub-isotype mAbs) against histamine (HA) conjugated to bovine serum albumin using glutaraldehyde-NaBH4. Among these, AHA-1 mAb was found to be the most useful for HA immunocytochemistry (ICC) in terms of specificity and sensitivity without non-specific immunobinding. AHA-1 was demonstrated to be specific to HA with an enzyme-linked immunosorbent assay (ELISA) binding test, simulating the ICC of tissue sections, and not reactive to any of the other amino acids and peptides with N-terminal histidine tested. By use of this antibody, indirect immunoperoxidase staining was observed in rat stomach fixed with glutaraldehyde (GA) in combination with NaBH4 reduction. In contrast, no immunoreactivity was seen in tissue fixed only with GA. Absorption controls indicated that the immunostaining could be completely inhibited by GA-conjugated HA, which was consistent with the results of an ELISA inhibition test. No cross-reactivity occurred with other GA-conjugated amino acids. ICC staining was dense in the cytoplasm of gastric enterochromaffin-like cells and very weak in mast cells. A new finding was that staining was noticed in some cell bands of the intermediate layer between the stratum lucidum and the stratum corneum of the stratified squamous epithelium of the gastric cardia, esophagus, tongue, and skin in rats. The results strongly suggest that the monoclonal antibody allowed highly specific detection of HA in animal tissues.

Animals↗

PubMed1997

Thermoregulatory responses of prepubertal boys and young men during moderate exercise.

Seven prepubertal boys (aged 10-11 years) and eleven young men (aged 21-25 years), matched for skinfold thickness and maximal oxygen uptake (VO2max) per unit of mass, cycled at an intensity of approximately 40% VO2max for 45 min in a warm condition (30 degrees C, 45% relative humidity). During exercise no age-related differences were observed for the increases in rectal temperature (Tre) and heart rate (HR), although the absolute Tre and HR were significantly greater for the boys because of a higher initial baseline (P < 0.05). Total body sweating rate [181 (SEM 12) vs 245 (SEM 12) g.m-2(.)45 min-1; P < 0.002] and local sweating rates (msw) on chest, back, and forearm were significantly lower for the boys (P < 0.001), as was metabolic heat production [203 (SEM 9) vs 276 (SEM 9) W.m-2; P < 0.01]. The lower msw in the boys was due to a lower output per activated sweat gland, even though they had a higher activated sweat gland density regardless of site. In contrast, cutaneous blood flow by laser Doppler flowmetry (LDF) in the boys was significantly greater on the chest and back, compared to the men (P < 0.003). The age-related differences in cutaneous vascular conductance (CVC) were more marked because of lower mean arterial pressure in the boys during exercise. However, forearm LDF and CVC were significantly lower for the boys (P < 0.008). No significant differences in LDF among sites were observed for the boys, whereas for the men LDF on the forearm was significantly greater than on the chest and back (P < 0.01). The boys showed lower mean skin temperatures (especially on the back and chest despite greater increments of LDF) after starting to sweat, whereas the men remained unchanged, suggesting that the heat loss on the trunk in the boys was promoted by greater increments of LDF despite lower msw, compared to the young men. It was concluded that during moderate exercise in an air temperature at 30 degrees C, prepubertal boys could thermoregulate as efficiently as young men by greater vasodilatation on their trunk despite lower msw. Furthermore regional differences may exist in the maturation-related modification of vasodilatation.

Adult↗

PubMed1997

Mechanisms of underdeveloped sweating responses in prepubertal boys.

To approach the mechanisms underlying the underdeveloped sweating responses of prepubertal boys, 8 boys (7-11 years old) and 11 men (21-25 years old) were exposed to a standard heat stress for 60 min. The test consisted of placing the subjects' lower legs into a 42 degrees C water bath while they sat in otherwise constant environmental conditions (ambient temperature 25 degrees C and 45% relative humidity). Rectal (T[re]) and skin temperatures, local sweating rates (mSW: on the chest, back, forearm and thigh) and the frequency of sweating expulsions (fSW: as an indicator of central sudomotor activity) were measured during the test. During the passive heating, no group differences were observed for the increase in T(re), mean skin temperature and metabolic heat production. However, mean body temperature (Tb) during heating was significantly higher for the boys (P < 0.001) because of a higher baseline T(re). The boys had lower mSW on the chest (P < 0.004) and thigh (P < 0.001) during the latter half of the 60-min exposure compared to the young men, although a similar mSW was observed between the groups during the first half of the test. The group difference of mSW on the back was similar to that of the chest and thigh, but the difference was not significant (P = 0.10). In contrast, the boys had a greater mSW on the forearm throughout the heating (P < 0.03). The slope of the mSW vs fSW relationship was significantly lower for the chest and thigh in the boys compared to the men (P < 0.05), and the same tendency was observed for the back (but was not significant, P = 0.10). In contrast, no difference was observed between the groups for the slope of mSW vs fSW for the forearm. Furthermore, a lower sweat output per gland was also observed on the chest, back, and thigh in the boys (P < 0.01), but not on the forearm. No group difference was observed for the slope of the fSW vs Tb relationship. These results suggest that the lower mSW observed in the prepubertal boys were due possibly to underdeveloped peripheral mechanisms, including the sweat glands and their surrounding tissues, rather than to an underdeveloped central drive activity related to sudomotor function. Regional differences may well exist in any underdeveloped peripheral mechanism associated with maturation.

Adult↗

PubMed1997

An asymptomatic infant with isolated 3-methylcrotonyl-coenzyme: a carboxylase deficiency detected by newborn screening for maple syrup urine disease.

UNLABELLED: We describe an asymptomatic male infant with isolated 3-methylcrotonyl-coenzyme A carboxylase deficiency who came to medical attention by newborn mass screening due to elevated blood leucine. The diagnosis was made by abnormal urinary organic acids at 20 days of age and was confirmed by assay of the carboxylase activities in cultured skin fibroblasts. CONCLUSION: More attention should be paid to slight elevations of leucine levels in newborn mass screening. Urinary organic acid analysis should be performed in conspicuous cases.

Carbon-Carbon Ligases↗

PubMed1997

Acute effects of pioglitazone on glucose metabolism in perfused rat liver.

Pioglitazone, a thiazolidinedone derivative, decreases insulin resistance and improves hyperglycemia in insulin-resistant obese and/or diabetic animals. However, the mechanisms by which hyperglycemia is improved are not well defined. We investigated the effects of pioglitazone on hepatic glucose metabolism using a perfused rat liver model. Perfusion with the buffer containing 1-10 microM pioglitazone for 20 min dose-dependently increased the hepatic fructose 2,6-bisphosphate content, a potent activator of 6-phosphofructo 1-kinase. The fructose 2,6-bisphosphate level after 20 min perfusion with 10 microM pioglitazone was 64.9 +/- 14.5 pmol/mg.protein, significantly higher than the control (48.3 +/- 10.9 pmol/mg.protein). When the liver from a starved for 48 h rat was perfused with the buffer containing 2 mM lactate but no glucose, glucose was generated from lactate via the gluconeogenic pathway and flowed into the effluent perfusate at a constant rate of 31 +/- 0.6 mumol/g.liver/h. The addition of 10 microM pioglitazone decreased the glucose output rate to 19.3 +/- 3.8 mumol/g.liver/h. Dose-dependent inhibition of glucose output by pioglitazone was observed in the 1-10 microM dose range. These results indicate that pioglitazone may not only stimulate glycolysis but also inhibit gluconeogenesis in the liver. These acute and insulin-independent effects on hepatic glucose metabolism may partly account for the diverse anti-diabetic effects of pioglitazone.

Administration, Oral↗

PubMed1997

Oxytocin enhances action potentials in pregnant human myometrium--a study with microelectrodes.

OBJECTIVE: Our purpose was to quantitatively assess the effects of oxytocin on membrane properties in the pregnant human myometrium. STUDY DESIGN: Specimens were obtained from the lower uterine segment during cesarean section at term. Electrical activity was recorded from individual cells by a conventional microelectrode method and the membrane functions were analyzed. RESULTS: Two types of spontaneous action potentials were seen: a long plateau potential and a spike-like action potential. With no change in the resting membrane potential, low concentrations of oxytocin either evoked an action potential with a plateau phase, increased the amplitude and duration of the plateau potential, or increased the frequency of generation of action potentials. Oxytocin also lowered the threshold for evoking an action potential. Higher concentrations depolarized the membrane with an associated reduction in membrane resistance. CONCLUSION: Oxytocin augments the excitability of pregnant human myometrial cells by multiple actions on the membrane, affecting both frequency and amplitude of action potentials.

Action Potentials↗

PubMed1997

The novel compound NO-1886 elevates plasma high-density lipoprotein cholesterol levels in hamsters and rabbits by increasing lipoprotein lipase without any effect on cholesteryl ester transfer protein activity.

Lipoprotein lipase (LPL) and cholesteryl ester transfer protein (CETP) are determinants of high-density lipoprotein (HDL) cholesterol concentrations in plasma. We have previously reported that NO-1886, by increasing LPL activity, causes elevation of HDL cholesterol levels in rats. In the present study, we studied the effect of NO-1886 on CETP activity in experimental animals. Since previous reports suggest that rats may lack CETP, we examined hamsters and rabbits, as well as rats. We found that NO-1886 increased LPL activity, resulting in elevation of plasma HDL cholesterol in all three animals. We confirmed that rats lack CETP and that both hamsters and rabbits have high CETP activity. NO-1886 had no effect on CETP activity in hamsters and rabbits. These results demonstrate that the compound NO-1886 elevates HDL cholesterol in experimental animals by selectively increasing LPL activity without any effect on CETP. Animals with low CETP and high LPL activities appear to be more sensitive to NO-1886 than those with high CETP and low LPL activities.

Animals↗

PubMed1997

Pectinolytic enzymes from Pseudomonas marginalis MAFF 03-01173.

Two pectinolytic enzymes were purified from the culture broth of Pseudomonas marginalis pv. marginalis MAFF 03-01173 with total 33% recovery of the initial activity. From the substrate specificities against pectin and polygalacturonic acid, the requirement of calcium ion for the enzymatic activity, and the N-terminal sequences, the enzymes were identified as pectin lyase and pectate lyase. The M,s of pectin lyase and pectate lyase were estimated to be 34,000 and 43,000, respectively, by SDS polyacrylamide gel electrophoresis. Both enzymes showed almost the same pH dependent activity curves with the highest activity at pH 8.3

Amino Acid Sequence↗

PubMed1997

Identification of cell types producing RANTES, MIP-1 alpha and MIP-1 beta in rat experimental autoimmune encephalomyelitis by in situ hybridization.

The chemokines RANTES, macrophage inflammatory protein (MIP)-1 alpha and MIP-1 beta are members of the beta-family of chemokines and potent chemoattractants for lymphocytes and monocytes. To investigate the factors which regulate lymphocyte traffic in experimental autoimmune encephalomyelitis (EAE), we studied, by in situ hybridization analysis, the kinetics of mRNA expression and the potent cellular sources of RANTES, MIP-1 alpha and MIP-1 beta in the central nervous system (CNS) during the course of EAE. RANTES-positive cells appeared in the subarachnoid space and infiltrated the subpial region at around day 10, increased to a peak at days 12-13 and then decreased following the resolution of the acute phase of EAE, though elevated RANTES message expressions still remained on chronic subclinical stage. Most of RANTES positive cells were identified as T-lymphocytes located mainly around blood vessels, by combined studies of in situ hybridization and immunohistochemistry. The remainder of the RANTES-positive cells were astrocytes and macrophages/microglia. MIP-1 alpha and MIP-1 beta mRNA-positive cells appeared around day 10, increased further on days 12-13 and then gradually decreased. Most of the MIP-1 alpha- and MIP-1 beta-positive mononuclear cells were located around blood vessels. The kinetics of RANTES, MIP-1 alpha and MIP-1 beta expression paralleled those of the recruitment of infiltrating inflammatory cells and disease severity. Our observations support the possibility that chemokine production by T-cells, macrophages and astrocytes lead to the infiltration of inflammatory cells into the CNS parenchyma during the acute phase of EAE.

Animals↗

PubMed1997

Changes in expression and distribution of the glutamate transporter EAAT4 in developing mouse Purkinje cells.

EAAT4 is a Purkinje cell (PC)-specific, postsynaptic glutamate transporter in the adult mouse brain. Here, we performed developmental analyses to reveal its temporal expression in relation to PC differentiation. Using in situ hybridization, EAAT4 mRNA was specifically detected in the PC layer of the cerebellar primordium at embryonic day 13 (E13). During late fetal and neonatal periods, the transcripts were detected only in the PC layer in the caudal cerebellum. At postnatal day 7 (P7) and, thereafter, the prominent transcripts were found on monolayered PCs in the entire cerebellum. Using immunohistochemistry, low levels of EAAT4 immunoreactivity were first observed at E18 in the perikarya of PCs in the caudal cerebellum, and this pattern of immunostaining was maintained at P1 and P7. At P14 and, thereafter, the molecular layer in the entire cerebellum became immunopositive for EAAT4, and the intense immunoreactivity was detected preferentially in PC spines synapsing with parallel fiber terminals. Therefore, the present study has clarified that the transcription of EAAT4 begins in PCs from early embryonic stages, and that the synaptic localization of EAAT4 is established during the second postnatal week. When considered in the light of the synaptogenesis of parallel fiber-PC synapses which actively occurs in the rodent cerebellum during the second and third weeks of life, synaptic localization of the glutamate transporter EAAT4 may be closely associated with the synapse formation.

ATP-Binding Cassette Transporters↗

PubMed1997

Prominent expression of nuclear hormone receptor ROR alpha in Purkinje cells from early development.

The ROR alpha is a member of the nuclear hormone receptor gene superfamily, and its deletion causes the staggerer mutation in mice. In the staggerer mutant mouse, Purkinje cells (PCs) are severely affected in the cytology, synapse formation and gene expression. We previously found the presence of mediolateral compartments unique to the staggerer cerebellum, based on different degrees of abnormalities in the cytology and gene expression. In this paper we investigated expression of the ROR alpha mRNA in developing mouse cerebellum, with a particular interest in its regional difference. At embryonic day 15, the ROR alpha mRNA was expressed at the highest level in the PC plate. The prominent expression in PCs was maintained from late embryonic stage through mature stage. At any developmental stages, no apparent regional differences in the ROR alpha mRNA expression were detected in the mediolateral and rostrocaudal axes of the cerebellum. The high expression from early developmental stages provides a molecular-anatomical basis for its important role in phenotypic differentiation of PCs. However, the even distribution in the cerebellum suggests that the unique staggerer compartments are not directly related to the loss of ROR alpha function.

Aging↗

PubMed1997

Appearance of a fast inactivating voltage-dependent K+ currents in developing cerebellar granule cells in vitro.

To elucidate the molecular mechanisms that regulate the maturation of action potential, we began by examining voltage-dependent K+ currents, known to contribute to the maturation of action potential, of developing granule cells in mouse cerebellar microexplant cultures. The migration of developing granule cells in this culture is reported to mimic the in vivo process, but their specific identification is still incomplete. In this study, we identified and characterized granule cells in this culture. Immunocytochemical analysis found that granule cells migrated radially out from explants and subsequently formed small clusters and also that their morphology changed from a bipolar to a T shape during migration. Moreover, in the electrophysiological study, the GABA response of granule cells in this culture clarified that the electrophysiological properties of granule cells were normally maintained. We therefore have concluded, that this culture system is a powerful tool for investigating the differentiation of cerebellar granule cells. Based on these findings, we recorded voltage-dependent K+ currents of developing granule cells in this culture, while concurrently observing their morphology. Our results show that voltage-dependent K+ currents of developing granule cells change from delayed rectifier to A current in parallel with their morphological changes from bipolar to T-shaped cells.

Animals↗

PubMed1997

Structure and functional expression of the cloned mouse neuronal high-affinity glutamate transporter.

A cDNA encoding a neuron-specific glutamate transporter was isolated from mouse cerebellum and characterized. Expression of this cDNA in HEK293 cells induced high-affinity uptake of L-glutamate that was dependent on external Na+. The deduced amino-acid sequence of the cDNA shares 96% identity with its human homologue. Northern blot analysis of mouse tissues revealed that the mRNA of this transporter is specific to the brain. In situ hybridization in mouse brain sections showed that the mRNA is expressed densely and selectively in cell bodies of Purkinje cells.

ATP-Binding Cassette Transporters↗

PubMed1997

Possible interaction between cisapride and bromperidol.

1. The case of a schizophrenic patient taking bromperidol (18 mg/day), whose psychotic symptoms deteriorated markedly after addition of cisapride (7.5 mg/day), is presented. 2. Retrospective determination of drug concentrations revealed that plasma concentrations of bromperidol and its reduced metabolite were increased after cisapride addition. 3. The present study thus suggests that there is an interaction between cisapride and bromperidol.

Adult↗

PubMed1997

Clinical application of transiently evoked otoacoustic emissions after glycerol administration for diagnosis of sensorineural hearing loss.

Pure-tone audiometry and transiently evoked otoacoustic emission (TEOAE) measurements were made before and after glycerol administration in the ears of sensorineural hearing loss with three different clinical entities, i.e. Meniere's disease, cochlear Meniere's disease and unilateral sensorineural hearing loss of unknown cause without hearing fluctuation (SNHLWF). TEOAE was evoked after glycerol administration in several ears of Meniere's disease and cochlear Meniere's disease, in which it was not evoked before glycerol administration. Especially in patients with cochlear Meniere's disease, TEOAE was altered without an accompanying significant change in mean hearing level. The change in TEOAE after glycerol administration indicates that the active motile property of outer hair cells may be affected by endolymphatic hydrops.

Adult↗

PubMed1997

Neurofibromatosis type 1 and type 2: review of the central nervous system and related structures.

Although computed tomography (CT) provides a major imaging advance over conventional radiography and tomography in examining the whole body, the development of magnetic resonance (MR) imaging has proven to be an even greater breakthrough in diagnostic medical imaging. The anatomic detail demonstrated in a MR image is a representation of at least three physical properties of static-tissue: proton density, and T1 and T2 relaxation times. Intrinsic differences in proton density and, in particular, in proton relaxation times of tissues allow excellent image contrast between various normal structures and high sensitivity in detecting pathological states. This article discusses imaging features of neurofibromatosis, with particular emphasis on the potential of MR imaging.

Adolescent↗