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T Yuki

Publications and source records attributed to T Yuki.

At least 19 recordsLinked to original sources
PubMed2006

Evaluation of modified crystal violet chromoendoscopy procedure using new mucosal pit pattern classification for detection of Barrett's dysplastic lesions.

BACKGROUND: Pit pattern diagnosis is important for endoscopic detection of dysplastic Barrett's lesions, though using magnification endoscopy can be difficult and laborious. We investigated the usefulness of a modified crystal violet chromoendoscopy procedure and utilised a new pit pattern classification for diagnosis of dysplastic Barrett's lesions. METHODS: A total of 1,030 patients suspected of having a columnar lined oesophagus were examined, of whom 816 demonstrated a crystal violet-stained columnar lined oesophagus. The early group of patients underwent 0.05% crystal violet chromoendoscopy, while the later group was examined using 0.03% crystal violet with 3.0% acetate. A targeted biopsy of the columnar lined oesophagus was performed using crystal violet staining after making a diagnosis of closed or open type pit pattern with a newly proposed system of classification. The relationship between type of pit pattern and histologically identified dysplastic Barrett's lesions was evaluated. RESULTS: Dysplastic Barrett's lesions were identified in biopsy samples with an open type pit pattern with a sensitivity of 96.0%. Further, Barrett's mucosa with the intestinal predominant mucin phenotype was closely associated with the open type pit pattern (sensitivity 81.9%, specificity 95.6%). CONCLUSIONS: The new pit pattern classification for diagnosis of Barrett's mucosa was found to be useful for identification of cases with dysplastic lesions and possible malignant potential using a crystal violet chromoendoscopic procedure.

Acetates↗
PubMed2004

Barrett's oesophagus with predominant intestinal metaplasia correlates with superficial cyclo-oxygenase-2 expression, increased proliferation and reduced apoptosis: changes that are partially reversed by non-steroidal anti-inflammatory drugs usage.

BACKGROUND: Cyclo-oxygenase-2 expression has been reported to play an important role in the metaplasia-dysplasia-carcinoma sequence in Barrett's oesophagus. However, the existence of cyclo-oxygenase-2 expressing cells in Barrett's epithelium is still uncertain. AIM: To identify the cells that express cyclo-oxygenase-2 protein and to investigate the relationship between cyclo-oxygenase-2 expression and mucin-phenotype of Barrett's epithelium. METHODS: Sections from 466 biopsy samples of Barrett's epithelium from 358 non-medicated patients were immunohistochemically examined for the cyclo-oxygenase-2 expression, mucin-phenotype, cell proliferation and apoptosis. RESULTS: Cyclo-oxygenase-2 expression was detected in 71.0% of Barrett's epithelium biopsy samples. In Barrett's epithelium with the gastric predominant mucin-phenotype, cyclo-oxygenase-2 expression was mainly found in stromal and deep epithelial cells, whereas in intestinal predominant mucin-phenotype, it was mostly in superficial epithelial cell. A significant elevation of proliferating cell nuclear antigen index and suppression of apoptotic index was observed in Barrett's epithelium with superficial epithelial cyclo-oxygenase-2 expression. Neither such elevation of proliferating cell nuclear antigen index nor the suppression of apoptotic index could be found in chronic non-steroidal anti-inflammatory drugs users. CONCLUSIONS: Barrett's epithelium with intestinal mucin and superficial epithelial cyclo-oxygenase-2 expression possess a higher proliferation potential, but this risk may be thwarted by non-steroidal anti-inflammatory drugs administration.

Anti-Inflammatory Agents, Non-Steroidal↗
PubMed2003

Expression of midkine and receptor-like protein tyrosine phosphatase (RPTP)-beta genes in the rat stomach and the influence of rebamipide.

BACKGROUND: Midkine has been reported to bind to receptor-like protein tyrosine phosphatase (RPTP)-beta and to play important roles in growth and differentiation of various cells. Midkine is expressed in rat stomach during experimental ulcer healing, suggesting that the midkine-RPTP-beta system has some physiological functions in the stomach. Rebamipide is a mucoprotective drug used for the treatment of gastric ulcers. We have tested the hypothesis that the ulcer healing mechanism stimulated by rebamipide is linked physiologically to the gastric midkine-RPTP-beta system. MATERIALS AND METHODS: Seven-week-old-male Wistar rats were used. Midkine and RPTP-beta gene expression in rat stomach was investigated by laser capture microdissection coupled with the reverse transcription-polymerase chain reaction (RT-PCR). The effects of rebamipide on midkine and RPTP-beta expression in rat stomach and the gastric epithelial cell line RGM1 were evaluated by RT-PCR and Northern blot analyses. RESULTS: Midkine and RPTP-beta expression was detected in the gastric mucosal, submucosal and muscle layers. Rebamipide stimulated both midkine and RPTP-beta expression in rat stomach and RGM1 cells. CONCLUSION: Rebamipide may protect the gastric mucosa by regulating midkine and RPTP-beta expression.

Alanine↗
PubMed2002

[Three cases with a mediastinal neurinoma developed in a same family].

A 47-years-old woman (case 1) was admitted to our hospital because of a mediastinal mass. We performed an operation by VATS under the diagnosis of a mediastinal neurinoma. The histology of it was a neurinoma. Her father (case 2) had undergone a resection of a mediastinal neurinoma at the age of 42. Her brother (case 3) also had undergone a resection of mediastinal and intrathoracic neurinomas at the age of 37. A few years later, he underwent operations for neurinomas in limbs 2 times. We suppose patients with a mediastinal neurinoma have little complaints in many cases, so there are a number of patients who have a mediastinal neurinoma without being discovered and treated. Although the neurinoma is not considered as a hereditary disease inherently, the cases, we experienced, might have some genetic disorders. In this concern, our cases are very rare and have a great interest.

Aged↗
PubMed2001

State-dependent action of grayanotoxin I on Na(+) channels in frog ventricular myocytes.

1. Distinct properties of grayanotoxin (GTX) among other lipid-soluble toxins were elucidated by quantitative analysis made on the Na(+) channel in frog ventricular myocytes. 2. GTX-modified current (I(GTX)) was induced strictly in proportion to the open probability of Na(+) channels during preconditioning pulses irrespective of its duration, amplitude or partial removal of inactivation by chloramine-T. This confirms that GTX binds to the Na(+) channel exclusively in its open state, while batrachotoxin (BTX) was reported to be capable of modifying slow-inactivated Na(+) channels, and veratridine exhibited voltage-dependent modification. 3. The GTX-modified channel did not show any inactivation property, which is different from reported results with veratridine and BTX. 4. Estimated unbinding rates of GTX were in reverse proportion to the activation curve of GTX-modified Na(+) channels. This was not the previously reported case with veratridine. 5. A model including unbinding kinetics of GTX and slow inactivation of unmodified Na(+) channels in which GTX was permitted to bind only to the open state of Na(+) channels indicated that unbinding reactions of GTX occur only in the closed state.

Animals↗
PubMed2001

Pulmonary resection for metastases from colorectal cancer.

BACKGROUND: We reviewed our experience in the surgical treatment of 47 patients with colorectal pulmonary metastases and investigated factors affecting their survival. METHOD: From September 1986 to December 1999, 47 patients underwent 59 thoracotomies for pulmonary metastases from colorectal cancer. RESULTS: The median interval between colorectal resection and lung resection (disease-free interval [DFI]) was 33 months. Overall, 5-year survival was 48%. Five-year survival was 51% for patients with solitary metastasis (n = 30), 47% for patients with ipsilateral multiple metastases (n = 11), and 50% for patients with bilateral metastases (n = 6), and there were no significant differences. Five-year survival was 80.8% for 14 patients with DFI of < 2 years and 39.7% for 30 patients with a DFI of > 2 years (p = 0.22). Five-year survival for 11 patients with normal prethoracotomy carcinoembryonic antigen (CEA) levels was 70%, and that for 26 patients with elevated prethoracotomy CEA levels (> 5 ng/mL) was 36% (p < 0.05). Eight patients had extrathoracic disease. The median survival time after pulmonary resection was 18.5 months, and the 5-year survival was 60%. A second resection for recurrent metastases was performed in five patients, and a third resection was done in one patient. All six patients are alive. The median survival of five patients who underwent a second thoracotomy was 22 months (range, 2 to 68 months), and one patient is alive 39 months after the third resection. CONCLUSION: Pulmonary resection for metastases from colorectal cancer may help prolong survival in selected patients, even with bilateral lesions, recurrent metastasectomy, or extrathoracic disease. Prethoracotomy CEA level was found to be a significant prognostic factor.

Adult↗
PubMed2001

Novel site on sodium channel alpha-subunit responsible for the differential sensitivity of grayanotoxin in skeletal and cardiac muscle.

We searched for sites on the alpha-subunit of the fast Na(+) channel responsible for the difference in GTX (grayanotoxin) sensitivity of the skeletal- and cardiac-muscle Na(+) current. cDNA clones, encoding the skeletal or cardiac isoforms of the alpha-subunit, were inserted into a mammalian expression vector and transiently transfected into human embryonic kidney cells. The expressed channels were measured using whole-cell patch-clamp techniques and examined for GTX sensitivity. As a measure of GTX sensitivity, we used relative chord conductance (ratio of maximum chord conductance of noninactivating GTX-modified Na(+) currents to that of unmodified peak currents). Wild-type channels from skeletal muscle (mu 1) were more sensitive to GTX modification than wild-type cardiac channels (rH1) by a factor of 1.6. To facilitate exploration of alpha-subunit sites determining GTX sensitivity, we used SHHH, a chimera of skeletal muscle (S) domain D1 and heart muscle (H) domains D2D3D4 with supernormal sensitivity to GTX I (1.5-fold of wild-type mu 1). Successive replacement of Ser-251 (D1S4-S5 intracellular loop) and Ile-433 (D1S6 transmembrane segment), with corresponding rH1 residues Ala and Val, reduced, in a stepwise manner, the GTX sensitivity of the chimera and related mutants to that of wild-type rHl. We concluded that, in addition to Ile-433, known as the GTX-binding site, Ser-251 represents a novel site for GTX modification.

Binding Sites↗
PubMed2001

[Clinical efficacy of magnetic resonance cholangiopancreatography in the diagnosis of biliary tract diseases].

This study was carried out to clarify the efficacy of magnetic resonance cholangiopancreatography (MRCP) in the diagnosis of biliary tract diseases, Three hundred and eleven patients who underwent MRCP and ERCP during the period from January 1999 to December 1999 at our institution were included in the study. Two gastroenterologists who were blinded to results of direct cholangiography and final diagnoses interpreted MRCP images prospectively. The biliary duct was visualized by MRCP and ERCP in 99.4% and 89.5% of the cases, respectively. The sensitivity, specificity, and accuracy of MRCP in the diagnosis of choledocholithiasis were 95%, 97%, and 97%, respectively. MRCP depicted the presence of strictures with a sensitivity, specificity, and accuracy of 97%, 96%, and 96%, respectively. There were three false-positive cases because of artifacts from arterial compression, The accuracy of MRCP and ERCP in differentiation of benign strictures from malignant ones was 85% and 96%, respectively. Based on these results, it is concluded that MRCP has high capability in visualization of the biliary tree, and in detection of stones and strictures, To avoid over and under-diagnosis, awareness of some pitfalls inherent in, MRCP is important. We suggest that MRCP should be recommended for patients with suspicion of biliary tract diseases in the initial stage of making diagnosis.

Adult↗
PubMed2000

On site of action of grayanotoxin in domain 4 segment 6 of rat skeletal muscle sodium channel.

Grayanotoxin I (GTX I) is a diterpenoid extracted from the family of Ericaceae that binds to Na(+) channels and causes persistent activation. We investigated the interaction of GTX I with the amino acid residues I1575, F1579 and Y1586 in transmembrane segment D4S6 of micro1. In F1579A, GTX shifted the threshold potential about 50 mV in the hyperpolarizing direction and modified Na(+) channels twice as efficiently as that in wild-type. In contrast, these GTX-effects were eliminated completely in the I1575A mutant and were reduced substantially in mutant Y1586A. Lysine substitution for F1579 significantly reduced and for Y1586 completely eradicated the GTX-effect. Our data suggest that the GTX receptor site shares overlapping but non-identical molecular determinants with BTX in D4S6 and has common molecular determinants in D1S6.

Animals↗
PubMed2000

Effect of sulfhydryl reagents on the regulatory system of the L-type Ca channel in frog ventricular myocytes.

The effects of sulfhydryl (SH) reagents on the L-type Ca current (ICa) were studied in frog ventricular myocytes using the whole-cell patch-clamp method. Methanethiosulfonate ethylammonium (MTSEA+) was found to enter the cell through the membrane and cause a remarkable increase in Ica from the intracellular side. Methanethiosulfonate ethyltrimethylammonium (MTSET+) and methanethiosulfonate ethylsulfonate (MTSES-) could not penetrate the membrane and were effective only when directly applied to the intracellular side. In addition, suppressive effects on ICa of these MTS reagents were indicated by the following observation. A progressive decay in the peak amplitude of ICa after establishing maximal ICa, stimulated by intracellular MTSET+, was prevented by adding extracellular dithiothreitol (DTT). The SH-oxidizing agents N-ethylmaleimide (NEM), chloramine-T (CL-T), 2,2'-dithiodipyridine (DTDP) and 2,2'-dithio-bis-5-nitropyridine (DTBNP) also exerted a stimulatory effect on Ica. The effect of SH reagents persisted even when cAMP production was inhibited with Rp-cAMP-S, or when G-protein was inhibited with 1 mM GDPbetaS, indicating that the effect is not due to cAMP production or G-protein stimulation. It is concluded that there are sites on the Ca channels that are subject to direct modification by SH reagents.

2,2'-Dipyridyl↗
PubMed2000

An analysis of the variations in potency of grayanotoxin analogs in modifying frog sodium channels of differing subtypes.

Responses of tetrodotoxin-sensitive (TTX-s) and insensitive (TTX-i) Na(+) channels, in frog dorsal root ganglion (DRG) cells and frog heart Na(+) channels, to two grayanotoxin (GTX) analogs, GTX-I and alpha-dihydro-GTX-II, were examined using the patch clamp method. GTX-evoked modification occurred only when repetitive depolarizing pulses preceded a single test depolarization; modification, during the test pulse, was manifested by a decrease in peak Na(+) current accompanied by a sustained Na(+) current. GTX-evoked modification of whole-cell Na(+) currents was quantified by normalizing the conductance for sustained currents through GTX-modified Na(+) channels to that for the peak current through unmodified Na(+) channels. The dose-response relation for GTX-modified Na(+) channels was constructed by plotting the normalized slope conductance against GTX concentration. With respect to DRG TTX-i Na(+) channels, the EC(50) and maximal normalized slope conductance were estimated to be 31 microM and 0.23, respectively, for GTX-I, and 54 microM and 0.37, respectively, for alpha-dihydro-GTX-II. By contrast, TTX-s Na(+) channels in DRG cells and Na(+) channels in ventricular myocytes were found to have a much lower sensitivity to both GTX analogs. In single-channel recording on DRG cells and ventricular myocytes, Na(+) channels modified by the two GTX analogs (both at 100 microM), had similar relative conductances (range, 0.25-0.42) and open channel probabilities (range, 0.5-0.71). From these observations, we conclude that the differences in responsiveness of DRG TTX-i, and ventricular whole cell Na(+) currents to the GTX analogs studied are related to the number of Na(+) channels modified.

Animals↗
PubMed2000

[IFOBT-positive gastric cancer].

Among 888 patients who underwent operation or endoscopic resection for gastric cancer (1994-1998), 75 patients, who had no colorectal disease or only small polyps 5 mm or less in diameter, were positive on the immunologic fecal occult blood test (IFOBT) (the positive group). They are compared with the other 813 patients (the negative group) as to the following 6 points: symptoms, presence of anemia, depth of invasion including macroscopic appearance, location, maximum diameter of lesions, and microscopic findings. The rate of positive-IFOBT gastric cancer was 8.4%. The average blood hemoglobin concentration was significantly lower in the positive group than in the negative group. Advanced cancers, especially type 2 and 3, were significantly more frequent in the positive group than in the negative group. The size of the lesions tended to be larger in the positive group than in the negative group. There was no difference between the groups as to symptoms, location, depth of invasion and microscopic findings. In conclusion, IFOBT-positive patients who have no colorectal disease or only small polyps 5 mm or less in diameter should be recommended to undergo upper gastrointestinal endoscopy.

Female↗
PubMed2000

[The significance of magnetic resonance cholangiopancreatography in acute cholecystitis].

To clarify the significance of magnetic renonance cholangiopancreatography (MRCP) in the acute phase of acute cholecystitis, MRCP was carried out in forty-five patients with acute cholecystitis in their acute phase. The MR pericholecystic high signal was observed in 38 of the 45 patients (84%). Enlargement of the gallbladder, presence of gallstones, and impacted stones was seen in 71%, 53%, and 18%, respectively. The MR pericholecystic high signal was classified into four categories: type 0, not observed; type 1, a liner high signal; type 2, a band-like high signal; type 3, a radiating high signal. In patients who showed a type 3 MR pericholecystic high signal, 91% required percutaneous transhepatic gallbladder drainage, and most of the gallbladders were diagnosed as necrotic cholecystitis by histology. The accuracy of MRCP for the diagnosis of choledocholithiasis was 96%. It was suggested that MRCP for patients with acute cholecystitis in the acute phase provides useful information for planning the treatment.

Acute Disease↗
PubMed1999

Variation in urinary flow according to voiding position in normal males.

Our objective was to study whether the urinary flow rate would vary according to voiding position. Twenty-one normal healthy male volunteers aged 24 to 40 years (mean, 29 years) were studied. The bed used was designed so that a hole could be opened at its center for voiding, and the bed could be bent at two points so that the subject could void in various positions. Urinary flow was measured with a portable uroflowmeter (P-Flow), which permits measuring urinary flow rate. Each subject assumed five voiding positions (standing, sitting, lateral, supine, and prone) in random order. Urinary flow was measured at least twice in each position to record a stable voiding. For voiding in the lateral position, subjects were instructed to void while bending the upper leg to keep an open angle between the legs. All subjects were also instructed to void without increasing abdominal pressure. Maximum flow rate was 20.7 +/- 6.59 mL/sec with voided volume of 262 +/- 77.8 mL in the lateral, 22.1 +/- 7.05 mLl/sec with voided volume of 309 +/- 130 mL in the supine, 25.0 +/- 8.25 mL/sec with voided volume of 287 +/- 122 mL in sitting, 27.1 +/- 8.89 mL/sec with voided volume of 263 +/- 102 mL in the standing, and 28.7 +/- 10.6 mL/sec with voided volume of 303 +/- 98 mL (mean +/- SD) in the prone positions. The maximum and mean urinary flow rates were greatest in the prone position. With regard to these parameters, significant differences were noted between the prone and lateral positions and between the prone and supine positions. In conclusions, the maximum urinary flow rate was highest in the prone position, followed by the standing, sitting, supine, and finally the lateral positions in normal males. Neurourol. Urodynam. 18:553-557, 1999.

Adult↗
PubMed1999

Regulation of L- and N-types of Ca2+ channels by intracellular ATP4- in frog dorsal root ganglion neurons.

The roles of free Mg2+ ions, ATP4- ions and Mg-ATP complexes in the regulation of N- and L-types of Ca2+ channels were studied in frog dorsal root ganglion (DRG) neurons using the whole-cell patch-clamp technique. Because Mg2+ ions interact with ATP4- ions to form Mg-ATP complexes, addition of one species can influence the concentrations of the other two. In this study their concentrations were carefully controlled by varying the concentrations of two constituents at a time while keeping the third constant. The effects of each of the three species on barium currents through L-type (IBaL) and N-type (IBaN) Ca2+ channels were plotted against its concentrations. The dose-response curves for ATP4- show that IBaL and IBaN proportionally increased with ATP4- concentrations up to 1 mM at three different Mg2+ concentrations. At a fixed concentration of ATP4-, IBaL and IBaN remained unchanged even when pMg changed from 3 to 5. Dose-response curves for IBaL and IBaN plotted against Mg-ATP concentration did not show a consistent pattern. H-7 and Mg2+ ions did not exert any blocking effect on the activity of either Ca2+ channel type, and neither dibutyryl-cAMP nor NKH-477 had any stimulating effect, suggesting that phosphorylation is not likely to be involved in ATP-induced potentiation. From these observations, it is concluded that L-type and N-type Ca2+ channels in frog DRG neurons are regulated by ATP4- ions alone, and that the neuronal Ca2+ channels are regulated by mechanisms that are different from those regulating the cardiac Ca2+ channels.

1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine↗