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T Matsuoka

Publications and source records attributed to T Matsuoka.

At least 19 recordsLinked to original sources
PubMed1995

Expression of CD38 gene, but not of mitochondrial glycerol-3-phosphate dehydrogenase gene, is impaired in pancreatic islets of GK rats.

Goto-Kakizaki (GK) rat, a rodent model of spontaneously occurring non-insulin dependent diabetes mellitus (NIDDM), exhibits impaired glucose-stimulated insulin secretion. To explore the background of the beta-cell dysfunction in NIDDM, we investigated whether and how the expression pattern of factors that would potentially be involved in the glucose-stimulated insulin secretion machinery is changed in GK rats. Using quantitative reverse transcription-PCR (RT-PCR) method, we found that the gene expression of CD38, a type 2 membrane protein which has ADP-ribosyl cyclase activity, is reduced by approximately 50% in islets of GK rats. Despite previous studies showing reduction in the FAD-linked mitochondrial glycerol-3-phosphate dehydrogenase (mGPDH) activity in GK rats, the mGPDH mRNA amounts were equal to those in the control Wistar rats, suggesting a difference that arose post-transcriptionally. These observations support the idea that multiple defects of the glucose-responsive insulin secreting machinery are involved in the development of diabetes in GK rats.

ADP-ribosyl Cyclase↗
PubMed1995

Photoactivated inhibition of superoxide generation and protein kinase C activity in neutrophils by blepharismin, a protozoan photodynamically active pigment.

Blepharismin is an endogenous photosensitizing pigment found in the protozoan Blepharisma. This pigment inhibited the generation of superoxide anion (O2-.) in neutrophils not only via a diacylglycerol-induced protein kinase C (PKC)-dependent reaction but also by an arachidonate-induced PKC-independent reaction. The inhibition was light and concentration dependent for both reactions. Light-activated inhibition was strong at wavelengths between 520 and 570 nm but not above 610 nm. PKC activity in neutrophils and from rat brain was inhibited by blepharismin in a light- and concentration-dependent manner. Moreover, arachidonate-activated NADPH oxidase activity in a cell-free system was also inhibited by the pigment in a light- and concentration-dependent manner. These results suggest that blepharismin inhibits NADPH oxidase activation through the non-specific inhibition of various membrane-bound enzymes and that this inhibition may also be correlated with that of PKC.

Animals↗
PubMed1995

Ubiquitous, but variable, expression of two alternatively spliced mRNAs encoding mouse homologues of transcription factors E47 and E12.

Two basic helix-loop-helix (bHLH) transcription factors, E47 and E12, are involved in cell-specific gene expression as part of dimeric complexes which interact with the cis-acting motif E-box. Although both generated from a single gene (E2A) by means of alternative splicing, the structural difference in these bHLH regions between the two suggests that the two bHLH proteins may differ in some of their functions. As a step toward elucidating the individual implications of E47 and E12, we investigated the mRNA expression ratios of their homologues (A1 and kA1, respectively) in mouse tissues and cell lines. Both the A1 and kA1 mRNAs were ubiquitously expressed in all tissues examined. However, their ratios varied: e.g., skeletal muscle, 2.2 +/- 0.3 (mean +/- SE); spleen, 2.0 +/- 0.2; pancreatic islet cells, 1.2 +/- 0.2. The A1/kA1 ratios in the cell lines investigated were similar to those of their original tissues. In conclusion, the ubiquity in mRNA expression observed for both the E47 and E12 homologues in mouse provides support for their involvement in a broad range of transcriptional regulation. The variation in the A1/kA1 expression ratios, on the other hand, supports the idea that A1 (E47) and kA1 (E12) each have some unique roles in the functions of these E2A gene-encoded bHLH proteins.

Alternative Splicing↗
PubMed1995

Interaction between valproate formulation and phenytoin concentrations.

Changes in phenytoin concentrations caused by switching valproate formulations with different absorption rates were retrospectively investigated in eleven epileptic patients receiving treatment with both drugs. Total plasma phenytoin concentrations were measured before and after a standard tablet of valproate was replaced by the same dose as a slow-release tablet. The mean plasma phenytoin level rose significantly from 14.4 to 18.7 micrograms.ml-1. Nine of eleven patients had markedly increased phenytoin levels (by 21 to 72%), and two developed toxic symptoms. The results indicate that changing valproate formulations can cause major alterations in the plasma concentration of co-administered phenytoin.

Adolescent↗
PubMed1995

Liver injury as a model of uncontrolled hemorrhagic shock: resuscitation with different hypertonic regimens.

Using a standardized liver injury model of uncontrolled hemorrhage, we tested the effect of different hypertonic solutions on mortality, blood pressure, intra-abdominal bleeding, and circulating blood volume. After liver injury, rats were randomized to 4 groups: lactated Ringer's (LR, n = 10), Isosal (ISO, n = 10), hypertonic saline (HS, n = 10), and hypertonic sodium acetate (HA, n = 10). In all resuscitation groups, 4 mL/kg was infused at a rate of 0.4 mL/min. Blood volume was evaluated both directly and by estimation. Mortality was highest after HA resuscitation (40%) and lowest after HS resuscitation (0%), but this difference was not significant. Blood pressure was significantly higher after HS resuscitation, and this difference was sustained for 4 hours. The HA resuscitation did not increase blood pressure compared with LR resuscitation. Intraperitoneal blood volume was significantly higher with HS (25.5 +/- 0.7 mL/kg) and HA (26.8 +/- 1.2 mL/kg) than with LR (22.5 +/- 0.4 mL/kg). The HA resuscitation led to a significantly larger drop from baseline values of estimated terminal circulating blood volume than LR resuscitation. Nonparametric analysis combining survival time and directly measured change in blood volume demonstrated a significant advantage to HS, compared with LR. HA and HS resuscitations increased bleeding from uncontrolled solid viscus injury. The HS resuscitation restored blood pressure better than the other hypertonic solutions and maintained circulating blood volume in spite of increased bleeding. The HA and ISO resuscitations did not exhibit any advantage over LR in resuscitation of solid viscus injury.

Acetates↗
PubMed1995

Additional evidence for blepharismin photoreceptor pigment mediating step-up photophobic response of unicellular organism, Blepharisma.

In the ciliated protozoan, Blepharisma japonicum, the pink-colored pigment (blepharismin) contained in the pigment granules is believed to be the photoreceptor pigment responsible for the step-up photophobic response. When the cells partially bleached by extrusion of the pigment granules caused by cold shock were subsequently cultured under illuminated conditions, the pigment-less granules regenerated and the cells were further bleached (pigment content below 0.5%). The photosensitivity of such colorless cells disappeared completely. In contrast, the blepharismin pigment regenerated gradually when such colorless cells were transferred to darkness. The photosensitivity of the cells also recovered with regeneration of the pigment. We found that blepharismin pigment was not photobleached in the absence of O2. The step-up photophobic response was also completely repressed in the absence of O2. These results strongly confirm that blepharismin is a photoreceptor pigment mediating photobehavior of Blepharisma and that O2 is required for the early step in the phototransduction of the light-excited pigment.

Animals↗
PubMed1995

Effects of hypoxia and hypercapnia on the Hering-Breuer reflex of the conscious newborn rat.

We asked whether hypoxia and hypercapnia, singly or combined, affect the lung volume-dependent ventilatory inhibition [Hering-Breuer (HB) reflex] in newborn rats. Conscious rats 2, 5, and 8 days old were breathing in a flow plethysmograph. Mean lung volume was increased by applying a negative body surface pressure of 6 or 12 cmH2O. HB reflex was quantified as the inhibitory ratio (IR) of the apnea during the inflation expiratory time (TEinfl) to the control expiratory time (TEc), i.e., IR = TEinfl/TEc. In normoxia-normocapnia (control), IR with 6 cmH2O was approximately 8-12 at all ages and approximately doubled with inflation at 12 cmH2O. In hypoxia (HPX; 10% O2) or hypercapnia (HPCN; 3% CO2), IR decreased at 8 days, whereas it did not differ from the control value at 2 and 5 days. In HPX + HPCN, IR decreased at all ages. In HPX (at both 6- and 12-cmH2O inflations), in HPCN (6 cmH2O), or in HPX + HPCN (6 and 12 cmH2O), IR decreased significantly more at 8 days than at 2 days. Metabolic rate, simultaneously measured, decreased during HPX or HPX + HPCN by a similar amount at all ages. The ventilatory response to HPX or to HPCN was significantly more pronounced at 8 days than at 2 days. We conclude that, during the early postnatal development of the rat, HPX or HPCN, singly or combined, reduces the HB reflex inhibition in the oldest pups, with minimal or no effects in the youngest. These developmental differences cannot be explained by differences in metabolic drive on ventilation but are contributed to by differences in chemosensitivity.

Aging↗
PubMed1995

Apoptotic cell death triggered by nitric oxide in pancreatic beta-cells.

Nitric oxide (NO) is believed to be an effector molecule that mediates interleukin (IL)-1 beta-induced destruction and dysfunction of pancreatic beta-cells. We have demonstrated that both exogenous NO and NO generated endogenously by IL-1 beta brought about apoptosis of isolated rat pancreatic islet cells as well as pancreatic beta-cell tumor-derived cell line HIT. This apoptosis was characterized by cleavage of DNA into nucleosomal fragments of 180-200 bp and morphologically by nuclear shrinkage, chromatic condensation, and apoptotic body formation. The IL-1 beta-induced internucleosomal DNA cleavage occurred in a time- and dose-dependent manner. Actinomycin D, cycloheximide, and nitric oxide synthase inhibitors inhibited the DNA cleavage, which was correlated with the amount of NO produced, indicating that NO produced by HIT cells themselves could mediate the apoptosis. Furthermore, in the presence of tumor necrosis factor (TNF)-alpha, large amounts of NO were produced by IL-1 beta and DNA cleavage occurred more noticeably, although TNF-alpha alone did not generate NO. Streptozotocin (STZ), a diabetogenic reagent containing a nitroso moiety, also released NO and induced internucleosomal DNA cleavage in HIT cells. These results suggest that NO-induced internucleosomal DNA cleavage is an important initial step in the destruction and dysfunction of pancreatic beta-cells induced by inflammatory stimulation or treatment with STZ.

Amino Acid Oxidoreductases↗
PubMed1995

[Quantitative analysis of smooth pursuit eye movement].

Abnormalities of smooth pursuit eye movement (SPEM) have been estimated, mainly using the wave form on an electro-oculogram, in a qualitative way. Many methods for quantitative analysis of SPEM have been designed, though most are still uncommon in present clinical use. Using a personal computer, we developed a method of automatic quantitative analysis of ocular tracking eye movement recorded by electro-oculography (EOG). The design concept of this method is based on the observation that eye movement during ocular tracking consists of two different kinds of eye movements, one is SPEM and the other is saccade. The combination of SPEM and saccade (composite eye movement: CEM) commonly appears during ocular tracking. These two kinds of eye movement are essentially different not only in behavior but also about involved neural pathway in the central nervous system. From this point of view, we believe that the two kinds of eye movements involved in ocular tracking should be evaluated separately. The analysis method is outlined as follows. A horizontal sinusoidally moving visual target was employed to elicit ocular tracking eye movements. The test frequencies were set at 0.1, 0.2, 0.4 and 0.8Hz, and the amplitude of target motion was 15 deg at each frequency. The 20 seconds of eye movement data measured by EOG were fed into the computer through a digital-analog converter for further analysis. Using our original saccade detection algorithm, based on the physiological behavior of saccades, the saccadic components were detected and removed from the eye movement wave. The remaining parts, fragments of SPEM, were connected by means of interpolating defective parts. The reconstructed wave was a slow cumulative eye position curve (SCEP). Sinusoidal target motion, CEM and SCEP were processed by the FFT (Fast Fourier Transformation) method. Bode plots were applied to summarize the gain and phase of responses to SCEP and the target motion wave. These processes enable us to estimate abnormalities of SPEM such as low gain, abnormal phase shift and large trends in tested duration. We conclude that the method described here is useful for quantitative estimation of SPEM in clinical neuro-otological examinations.

Adult↗
PubMed1995

[A case of ruptured cerebral aneurysm associated with fenestrated vertebral artery in osteogenesis imperfecta].

An extremely rare case of ruptured cerebral aneurysm associated with a fenestrated vertebral artery in osteogenesis imperfecta (OI) is presented. A 33-year-old female suffering from OI was admitted to our hospital with severe headache and vomiting. A CT scan revealed subarachnoid hemorrhage. Cerebral angiography with four vessel study showed a fenestration in the V3 portion of the left vertebral artery and a dilatation in its V4 portion, but no cerebral aneurysm was detected. After conservative treatment for three weeks, repeated angiography demonstrated an aneurysm of the anterior communicating artery. A neck clipping of the aneurysm was performed successfully. The patient was discharged with no neurological deficits. OI is a hereditary connective tissue disease characterized by bone fragility. From her family history and clinical findings, the patient was suspected to have OI type I of Sillence's classification. Among the connective tissue diseases, OI does not have complications in the cerebrovascular system as frequently as other connective tissue diseases do, for example, Marfan's syndrome, Ehlers-Danlos syndrome, or pseudoxanthoma elasticum. Carotid-cavernous fistula and moyamoya disease have been the only complications reported in OI. However, dilatation of the aortic root and increased vascular fragility have been reported recently in OI. Although this is the first reported case of a ruptured aneurysm accompanied by a fenestration and a dilatation of the vertebral artery associated with OI, it was suggested that vascular fragility caused by collagen abnormality might affect the cerebral vasculature.

Adult↗
PubMed1995

Liver penetration and gastrobronchial fistula: unusual complication of a peptic ulcer.

The authors present the first case report on a patient with liver penetration and a gastrobronchial fistula from a gastric ulcer. Liver penetration was diagnosed by endoscopy, and the gastrobronchial fistula was noted on a computed tomography scan. An emergent total gastrectomy was performed because of uncontrolled massive gastric bleeding not responsive to conventional treatment. The initial treatment of choice for these patients should be conservative because both complications could potentially have been controlled by H2 blockers and percutaneous drainage of the abscess.

Bronchial Fistula↗
PubMed1995

[CT-guided stereotactic operation for cerebellar abscess by the transtentorial hiatus approach: a case report].

We reported a case of cerebellar vermian abscess, well managed by CT-guided stereotactic aspiration and drainage via the transtentorial hiatus route. A 69-year-old man was admitted to our hospital because of acute deterioration of bronchiectasis. About one month later, he complained of headache and gait unsteadiness. CT scan revealed a multilocular abscess in the cerebellar vermis. Although conservative therapy with antibiotics was applied, the symptoms deteriorated and the lesion continued to grow. Aspiration and drainage were therefore performed for the main lesion by CT-guided stereotactic surgery via the transtentorial hiatus route. This was completed without complications. The postoperative course was good and the lesion had disappeared when enhanced CT was carried out about 2 months after the operation. We consider this stereotactic transtentorial hiatus operation to be an effective treatment for patients such as the present one with a superior vermian lesion and who is at risk due to a poor respiratory condition.

Aged↗
PubMed1994

[Embolization of varicocele with ethanol].

Embolization with ethanol was performed in 40 varicocele patients to prevent recurrence due to collateral formation. A prescribed amount of ethanol (0.5-4 ml) was injected slowly into the testicular vein with the catheter tip as close as possible to the inguinal region. Embolization with stainless steel coils was also performed in 15 of the 40 patients. Immediately after embolization, three varicoceles were reduced in size, and 37 disappeared. Recurrence was recognized in only two patients. These patients were embolized at a proximal site above lumbar vertebra IV. Spermatic data have improved for 13 patients but not for one azoospermatic patient. Serious complications were recognized in only one patient, who received an injection of 15 ml ethanol in one dose. Therefore, we conclude that embolization with ethanol is an useful treatment for varicocele.

Adolescent↗
PubMed1994

[MR imaging findings in patients with epilepsy].

We retrospectively examined the MR imaging (MRI) findings in 144 patients with epilepsy (31 with temporal lobe epilepsy and 113 with other epilepsies). 110 cases (76.4%) showed abnormal findings such as spotty lesions in white matter, hippocampal atrophy and/or signal change, ventricular dilatation and/or deformity, developmental lesions, brain tumors and so on. Hippocampal atrophy and/or signal change was shown in 74.1% of temporal lobe epilepsy, a remarkably high percentage (P < 0.01) compared with the other types of epilepsies (18.1%). This finding means that hippocampal lesions may play a large part in the cause of temporal lobe epilepsy. Investigation of the relationship between clinical term and abnormal findings revealed that the longer the clinical term, the larger the number of hippocampal lesions, regardless of whether it is temporal lobe epilepsy or not. Thus hippocampal lesions may occur as a result of hypoxia accompanied with seizure. Therefore we recommend horizontal and/or vertical sections of hippocampus in MR imaging of all patients with epilepsy. Even though MR findings may reflect some secondary lesions, MRI will shed some light on the proper understanding of epilepsy.

Adolescent↗
PubMed1994

Neuroradiologic and electrophysiologic assessment of cervical spondylotic amyotrophy.

Dissociated motor loss due to cervical spondylosis and disc herniation was evaluated in 10 patients who presented with left deltoid paresis in the absence of sensory deficits or myelopathy. All of these cases underwent cervical anterior decompression. Based on magnetic resonance imaging, computed tomography myelography, and computed tomography discography, patients were divided into two pathologic types: The first showed focal bony spur and disc herniation with axial cord rotation and nerve root compression, and the second demonstrated ventral cord flattening. Electrophysiologic studies included evoked spinal potentials, motor evoked potentials, and evoked muscle action potentials. Motor evoked potentials, recorded epidurally from the ventral aspect of the thecal sac and the nerve root within the anterior discectomy or vertebrectomy sites, proved clinically most useful. Combining the latest available neuroradiologic and electrophysiologic information, 4 types of neural injury associated with deltoid pareses were identified in the 10 patients. The first included isolated C5 nerve root lesions; the second, C6 nerve root lesions; the third, both C5 and C6 nerve root lesions, and finally, intrinsic cord pathology.

Adult↗
PubMed1994

Combined antitumor effects of TNF and G-CSF on a human medulloblastoma xenograft line.

The antitumor effects of TNF and G-CSF on a xenograft line of human medulloblastoma were examined. (Method):1) A human medulloblastoma xenograft line was transplanted into nude mice. Tumor bearing nude mice were divided into the following eight groups: untreated controls (C); those receiving a subcutaneous injection of G-CSF for one week (G1); for four weeks (G2); those receiving an intratumoral injection of TNF for four weeks (Tit); an intravenous injection of TNF (Tiv); those receiving a combination of G1 and Tit (G1 + Tit); a combination of G2 and Tit (G2 + Tit); and a combination of G2 and Tiv (T2 + Tiv). The relative tumor weight in each group was calculated and any antitumor effects were examined by calculating a tumor growth inhibition ratio. 2) Tumor bearing nude mice were divided into the following two groups: those receiving a subcutaneous injection of G-CSF and an intravenous injection of TNF (G+T); and only an intravenous injection of TNF (T). We evaluated the pathological findings from the tumors at 0 h, 0.5 h, 1 h, 3 h, 6 h, 12 h, 24 h and 48 h after the TNF injection. Routine H.E. staining and immunostaining using antigranulocyte and antimacrophage antibodies were performed. (Results): 1) The tumor growth inhibition ratio was 0.112, 0.190, 0.287, 0.451, 0.347, 0.635, and 0.622 at G1, G2, Tit, Tiv, G1 + Tit, G2 + Tit, G2 + Tiv group. A combined antitumor effect was clearly seen in the G2 + Tit and the G2 + Tiv groups. 2) The tumor was fragmented by the infiltration of many inflammatory cells 24 hours after TNF injection. Many more macrophages were observed in the tumors of G+T mice than in the T mice. Granulocytes were observed only in the tumors of the G+T mice.

Animals↗