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M Furuse

Publications and source records attributed to M Furuse.

At least 91 records · Page 5Linked to original sources
PubMed1998

Occludin is concentrated at tight junctions of mouse/rat but not human/guinea pig Sertoli cells in testes.

Occludin is the only integral membrane protein identified to date as a component of tight junctions (TJs). Here, we examined the distribution and expression of occludin in murine testis bearing well-developed TJ. In the adult mouse testis, occludin was concentrated at TJ strands, which are located at the most basal regions of lateral membranes of Sertoli cells. In immunoblotting, occludin showed a characteristic multiple banding pattern, suggesting that occludin is highly phosphorylated in the testis. In 1-wk-old mouse testis, occludin was distributed diffusely at the lateral membranes of Sertoli cells, and even at this stage, highly phosphorylated occludin was detected. With development, occludin gradually became concentrated at the most basal regions of Sertoli cells. The same results were obtained in rat, but unexpectedly occludin was not detected in human or guinea pig Sertoli cells by immunofluorescence microscopy as well as by immunoblotting. Inasmuch as TJs are also well developed in Sertoli cells of these species, we concluded that, at least in the testes of these species, there are some Sertoli cell-specific isoforms of occludin or other TJ-associated integral membrane proteins that differ from occludin.

Animals↗
PubMed1998

[A case of hemangiopericytoma with multiple extracranial metastasis: a case report].

A case of a patient with hemangiopericytoma with multiple extracranial metastasis, who has survived for more than twenty years is reported. A fifty-five-year-old male presented brain tumor twenty years ago. He underwent total removal of the tumors, but recurrences occurred each time. Liver metastasis was found seven years ago. After that multiple metastases extended to the lung, vertebra and pancreas and operations and irradiations were performed. At present, there is no progression of the tumors and he enjoyed a high quality of life. We concluded that, to ensure long time survival, a patient with hemangiopericytoma must be monitored carefully for local recurrence and systemic metastases.

Brain Neoplasms↗
PubMed1998

B-cell monoclonality precedes the development of gastric MALT lymphoma in Helicobacter pylori-associated chronic gastritis.

Little is known about the temporal changes in Helicobacter pylori density and B-cell clonality during the evolution from chronic gastritis to gastric mucosa-associated lymphoid tissue (MALT) lymphoma. Biopsied specimens from 28 patients with chronic gastritis who developed gastric MALT lymphoma (group A) and from 24 similar patients who did not (group B) during an equivalent follow-up period (mean, 42 months) were retrospectively scored for histological features of MALT lymphoma (0 to 5) and H. pylori density (0 to 3). B-cell clonality was analyzed by polymerase chain reaction (PCR). During the observation period, the H. pylori density in group A decreased significantly in comparison with group B; the mean change in H. pylori density (final minus initial density) per 1000 days was -1.4 for group A and +0.2 for group B (P < 0.005). Monoclonality was detected more frequently in group A (79%) than in group B (21%; P < 0.005), and it preceded the histological evidence of malignant transformation in 64% of those patients who showed monoclonality in group A. These results suggest that H. pylori is thus more closely associated with the precursor or initial phase in the genesis of gastric MALT lymphoma than with the later phase, as its density decreases as the tumor progresses. The detection of B-cell monoclonality by PCR is thus of possible use for predicting the histological genesis of gastric lymphoma.

Adolescent↗
PubMed1998

[Reduction of helical artifact using SmartHelical algorithm].

Stair-step artifact is a serious problem in reconstructed images of multiplanar reformation (MPR), surface rendering and maximum-intensity projection (MIP). We developed a new algorithm, SmartHelical Algorithm (SHA), to reduce helical artifacts. SmartHelical Algorithm reduced helical artifacts significantly with slight worsening of longitudinal resolution. Noise was reduced and SNR was increased. SHA reduced stair-step artifact in reconstructed images of MPR, surface rendering and MIP, and improved image quality.

Adult↗
PubMed1997

The central corticotropin-releasing factor and glucagon-like peptide-1 in food intake of the neonatal chick.

Recently, we have reported that central administration of glucagon-like peptide-1 (GLP-1) strongly decreases food intake of chicks. The aim of this study was to elucidate whether suppressed food intake induced by the central injection of GLP-1 is mediated by activation of the hypothalamic-pituitary-adrenal axis. First, the effects of central administration of corticotropin-releasing factor (CRF) were investigated. Birds (2-day-old) were food-deprived for 3 h and then CRF or saline was injected intracerebroventricular (i.c.v.). CRF strongly inhibited food intake. Thereafter, effects of central CRF or GLP-1 on plasma corticosterone concentration were examined. CRF significantly stimulated corticosterone release, but GLP-1 did not alter plasma corticosterone concentration. These results suggest that CRF is a potent inhibitor of food intake in the chick, but the suppression of food intake induced by central GLP-1 may not be involved in the activation of hypothalamic-pituitary-adrenal axis.

Animals↗
PubMed1997

Activated Ki-ras enhances sensitivity of ceramide-induced apoptosis without c-Jun NH2-terminal kinase/stress-activated protein kinase or extracellular signal-regulated kinase activation in human colon cancer cells.

The activation of c-Jun NH2-terminal kinase (JNK)/stress-activated protein kinase (SAPK) and/or extracellular signal-regulated kinase (ERK) is involved in ceramide-induced apoptosis in certain cells. To examine the relationship between activated Ki-ras-mediated signals and ceramide-induced apoptosis in human colon cancer cells, JNK/SAPK and ERK activity, as initiated by ceramide, was examined in HCT116, which has a mutation of Ki-ras at codon 13, and HCT116-derived clones, HKe-3 and HKh-2, in which activated Ki-ras was disrupted through gene targeting. In HKe-3 and HKh-2, the activity of JNK/SAPK increased significantly within 60 min following C2 ceramide stimulation, and some apoptosis followed. In contrast, C2 ceramide caused a marked apoptosis in HCT116, but activation of JNK/SAPK was not observed. C2 ceramide did not activate ERK in any of the cell lines. These results suggest that activated Ki-ras contributes to the sensitivity of ceramide-induced apoptosis without JNK/SAPK or ERK activation and that other signaling pathways involved in ceramide-induced apoptosis may be present in human colon cancer cells.

Apoptosis↗
PubMed1997

Influence of fasting and neuropeptide Y on the suppressive food intake induced by intracerebroventricular injection of glucagon-like peptide-1 in the neonatal chick.

Recently, we have reported that central administration of glucagon-like peptide-1 (GLP-1) strongly decreased food intake of chicks. The aim of the present study was to elucidate whether suppressed food intake by central injection of GLP-1 would be modified by an appetite stimulant such as fasting and neuropeptide Y (NPY). Birds (2 days old) were starved for 3 or 6 h and then GLP-1 (0.03 microg/10 microl) or saline was injected by the intracerebroventricular (i.c.v.) route. Birds starved for 6 h ate significantly more food than those starved for 3 h, while irrespective of the time for fasting GLP-1 strongly inhibited food intake as rapidly as 10 min after i.c.v injection. The suppressive effect on food intake continued until 4 h after injection. Central administration of NPY (2.5 microg/10 microl) greatly enhanced food intake, but co-injection of GLP-1 (0.01, 0.02 or 0.03 microg/10 microl) decreased food intake in a dose-dependent fashion. Under GLP-1 (0.03 microg/10 microl) treatment, whether NPY modifies food intake of chicks in a dose-dependent manner was investigated by co-injection of graded levels of NPY (0.4, 1.0 and 2.5 microg/10 microl). GLP-1 completely inhibited the effect of NPY on food intake without a dose response. These results suggest that central GLP-1 may interact with NPY and may be the most potent inhibitor of food intake in the chicken.

Animals↗
PubMed1997

Possible involvement of phosphorylation of occludin in tight junction formation.

Occludin is an integral membrane protein localizing at tight junctions in epithelial and endothelial cells. Occludin from confluent culture MDCK I cells resolved as several (>10) bands between 62 and 82 kD in SDS-PAGE, of which two or three bands of the lowest Mr were predominant. Among these bands, the lower predominant bands were essentially extracted with 1% NP-40, whereas the other higher Mr bands were selectively recovered in the NP-40-insoluble fraction. Alkaline phosphatase treatment converged these bands of occludin both in NP-40-soluble and -insoluble fractions into the lowest Mr band, and phosphoamino acid analyses identified phosphoserine (and phosphothreonine weakly) in the higher Mr bands of occludin. These findings indicated that phosphorylation causes an upward shift of occludin bands and that highly phosphorylated occludin resists NP-40 extraction. When cells were grown in low Ca medium, almost all occludin was NP-40 soluble. Switching from low to normal Ca medium increased the amount of NP-40-insoluble occludin within 10 min, followed by gradual upward shift of bands. This insolubilization and the band shift correlated temporally with tight junction formation detected by immunofluorescence microscopy. Furthermore, we found that the anti-chicken occludin mAb, Oc-3, did not recognize the predominant lower Mr bands of occludin (non- or less phosphorylated form) but was specific to the higher Mr bands (phosphorylated form) on immunoblotting. Immunofluorescence microscopy revealed that this mAb mainly stained the tight junction proper of intestinal epithelial cells, whereas other anti-occludin mAbs, which can recognize the predominant lower Mr bands, labeled their basolateral membranes (and the cytoplasm) as well as tight junctions. Therefore, we conclude that non- or less phosphorylated occludin is distributed on the basolateral membranes and that highly phosphorylated occludin is selectively concentrated at tight juctions as the NP-40-insoluble form. These findings suggest that the phosphorylation of occludin is a key step in tight junction assembly.

Animals↗
PubMed1997

Intracerebroventricular injection of mammalian and chicken glucagon-like peptide-1 inhibits food intake of the neonatal chick.

Glucagon-like peptide-1 (GLP-1), structurally similar to glucagon, is synthesized from a larger precursor, preproglucagon, and has been postulated to be a novel incretin. Recently, it was reported that central administration of GLP-1 decreased food intake in rats. The amino acid sequences of GLP-1 are identical in all mammals, and chicken GLP-1 exhibits a high homology with mammalian GLP-1. The aim of this study was to elucidate whether central injection of mammalian or chicken GLP-1 inhibits food intake in the chick, and to compare their effects. Intracerebroventricular administration of mammalian and chicken GLP-1 strongly inhibited food intake of chicks. However, the suppressive effect of both GLP-1 on food intake was similar. These results show that GLP-1 with a variety of amino acid sequences may be the most potent inhibitor of food intake in the chicken.

Amino Acid Sequence↗
PubMed1997

Effect of glycerol on blood flow distribution in tumoral and peritumoral brain tissue.

To evaluate the effect of glycerol, thirty-two patients with brain tumor were directed to the study, including 17 gliomas and 15 meningiomas. Blood flow before and after the administration of glycerol were measured with Xe CT. Glioma was significantly hypo-perfused. The peritumoral edema of glioma and meningioma were also hypo-perfused. On the other hand, Meningioma was significantly hyper-perfused. After the administration of glycerol, blood flows were increased except for glioma. We suggested that, vascular responses to glycerol was different in the two tumor types. The steal phenomena of blood flow might occur in glioma.

Brain Neoplasms↗
PubMed1997

Suppression of serum-induced c-jun expression by activated Ki-ras in human colon cancer cells.

Through gene-targeting, we have established human colon cancer cell lines, HK2-6 and HKe-3, with and without activated Ki-ras, respectively, derived from a human colon cancer cell line HCT116, and we have reported that activated Ki-ras is involved in the deregulation of c-myc expression. To further examine the relation between Ki-ras-mediated signals and other immediate early genes, c-jun was analyzed on these cells stimulated by serum. Rapid and strong induction of c-jun was observed in HKe-3, but not in HCT116 or HK2-6. To elucidate the regulatory mechanisms of c-jun expression by Ki-ras, protein kinase C (PKC) and c-Raf were examined at serum-starved and serum-stimulated conditions. Phosphorylations of c-Raf were same among these cells, however, the cytosolic PKC activity in HKe-3 was two times higher than that in HCT116 on serum-starved and serum-stimulated conditions. These results suggested that serum responsiveness of c-jun may be suppressed by activated Ki-ras through PKC rather than c-Raf pathway in colon cancer cells.

Calcium-Calmodulin-Dependent Protein Kinases↗
PubMed1997

Asymmetrical or heterogeneous enhancement of the internal jugular veins in contrast-enhanced CT of the head and neck.

With faster CT scanners, asymmetric/heterogeneous enhancement (ASHE) of the internal jugular veins (IJVs) is frequently encountered in the absence of pathology. We investigated the frequency, side, pattern and significance of ASHE in 200 patients with various head and neck lesions. Non-ionic contrast medium (300 mgI/ml) was infused into a forearm vein (right, n = 100); left, n = 100). Forty seconds after contrast medium injection, contiguous 5-mm-thick sections were obtained craniocaudally from the skull base to the aortic arch. CT machines with two different scanning cycle times (3 s, n = 100; 2 s, n = 100) were used. ASHE of the IJVs was observed in 51 patients (25.5%); the patient group receiving a right-sided injection with a 2-s scan cycle machine, showing a higher frequency (44%). ASHE was divided into four patterns: homogeneous low density, focal low density, heterogenous opacification and fluid-fluid level formation. ASHE was frequently observed in routine contrast-enhanced CT of the head and neck. Frequency of ASHE increased when the scanning cycle was shorter. We should be aware of this phenomenon to avoid its misinterpretation as venous thrombosis or other pathology.

Adolescent↗
PubMed1997

Cholinergic factors are not involved in the delayed diet passage from the crop of chicks given medium chain triacylglycerol.

The role of cholinergic mechanisms in the delayed food passage from the crop induced by medium chain triacylglycerol was investigated in the young chicken. Vagotomy altered the crop emptying of chicks given dietary long chain triacylglycerol, but did not alter it in chicks given dietary medium chain triacylglycerol. On the contrary, denervation in the cranial rete and lateral commissure of the gizzard further inhibited the food passage induced by medium chain triacylglycerol. Administration of cisapride, which induces acetylcholine release from the myenteric nerves, and atropine, a muscarinic cholinergic antagonist, both delayed crop emptying of chicks given medium chain triacylglycerol. These results demonstrate that cholinergic factors are not involved in the delayed forward movement of the food containing medium chain triacylglycerol from the crop of chicks.

Animals↗
PubMed1997

Effect of ketone bodies on crop emptying in the chicken.

1. The effect of ketone bodies on crop emptying was studied in chickens in 2 experiments. In the first, the effect of beta-hydroxybutyrate, acetoacetate or acetone on relative crop content was measured. The effects of dietary medium and long chain triacylglycerols upon serum beta-hydroxybutyrate were investigated in the second. 2. beta-Hydroxybutyrate, but not acetoacetate and acetone, delayed crop emptying in a dose dependent fashion. Serum beta-hydroxybutyrate concentration was high in chicks given medium chain triacylglycerol, when compared with long chain triacylglycerol. 3. The results suggest that delayed crop emptying induced by medium chain triacylglycerol could partly be explained by an enhanced concentration of serum beta-hydroxybutyrate, which is the result of the rapid oxidation of medium chain fatty acids.

3-Hydroxybutyric Acid↗
PubMed1997

Effects of dietary cholestyramine on the utilisation of diets containing medium or long chain triacylglycerols by chicks.

1. The effects of graded dietary concentrations of cholestyramine (CSTY, a bile acid binding polymer), which prevents micelle formation and bile acid reabsorption, on the lipid and energy metabolism of chicks given diets containing different dietary concentrations of medium chain triacylglycerol (MCT) and long chain triacylglycerol (LCT) were investigated. 2. MCT- or LCT-supplemented diets containing 100 or 200 g oil/kg diet and 0, 10 or 20 g CSTY kg were fed to 7 d old chicks for 10 d. As dietary CSTY concentration increased, a reduction in the metabolisable energy value was observed for both dietary lipid sources. Consequently, fat and energy retentions were also reduced as the dietary CSTY content increased.

Animals↗
PubMed1997

Magnetic resonance imaging quantitation of superior sagittal sinus flow: correlation to cerebral blood flow measured by xenon-enhanced computed tomography.

We compared measurements of venous blood flow velocity in the superior sagittal sinus (SSS) obtained by magnetic resonance imaging (MRI) and quantitative measurements of cerebral blood flow (CBF) obtained by xenon-enhanced CT, in neurosurgical patients and normal volunteers, to assess the clinical usefulness of MRI for determination of CBF. Flow measurements were obtained in 15 neurosurgical patients and 3 normal volunteers. SSS velocimetry was performed using the direct bolus imaging technique with a 1.5-tesla MRI system near the point of lambda on a sagittal MR image. Quantitative CBF was measured by xenon-enhanced CT and correlated with SSS flow velocity. We also examined the effect of surgical evacuation of a hematoma or cranioplasty in 3 patients, mannitol in 5 patients and acetazolamide in 4 patients by performing SSS velocimetry. The peak SSS flow velocity during the entire cardiac cycle was 27.2 +/- 6.3 cm sec-1 (mean +/- SD) in normal volunteers and 23.5 +/- 8.9 cm sec-1 in patients. The SSS flow velocity increased after surgery. Mean SSS peak flow velocity increased by 24% and 48% at 10 min after administration of mannitol and acetazolamide, respectively. SSS peak flow velocity showed significant linear correlations with both cerebral cortical (r = 0.74) and hemispheric flows (r = 0.73). Our results suggest that SSS flow velocity reflects CBF and that MRI assessment of SSS flow provides a simple method for assessing and monitoring global changes in cerebral hemodynamics.

Acetazolamide↗
PubMed1997

Computed tomography analysis of the anterior mediastinal fat after left upper lobectomy.

RATIONALE AND OBJECTIVES: The authors evaluate changes in the anterior mediastinal fat (AMF) after left upper lobectomy. METHODS: In 36 carcinoma patients undergoing left upper lobectomy, the area and volume of AMF were measured using computed tomography before and after surgery, and their relations to postoperative mediastinal deviation were examined. RESULTS: The postoperative AMF distribution was changed distinctly, showing marked increase from the aortic arch to the main pulmonary arterial level, with converse decrease at upper and lower slices, but no significant postoperative change was noted in total AMF volume. There was a close correlation between changes in AMF area and mediastinal deviation after lobectomy. In two patients, a pseudotumor composed of AMF was depicted on frontal radiograph postoperatively, pseudotumor was thought to appear when the postoperative mediastinal deviation was marked but unaccompanied by marginal fluid or fibrosis. CONCLUSIONS: The AMF distribution is distinctly changed postoperatively, the displaced AMF redistribution is considered to be the main cause of seemingly increased fat or pseudotumor.

Adipose Tissue↗