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Biomedical subjects

S Tamura

Publications and source records attributed to S Tamura.

At least 325 records · Page 18Linked to original sources
PubMed1996

[Emergency coronary artery bypass grafting (CABG) in a case of coronary occlusion secondary to long segmental dissection of left anterior descending artery after percutaneous transluminal coronary angioplasty (PTCA)].

A 60-year-old man with unstable angina underwent PTCA at left anterior descending artery (LAD) #6, which had stenosis of 90%. Subsequently, a long segmental dissection formed from #6 to #7 and the patients was scheduled for CABG. On the day before the expected date of CABG, he had an angina attack and a 12 lead electrocardiogram (ECG) showed ST segment and T wave elevation in V1-3. Coronary angiograms revealed 99% stenosis in LAD #6 and immediately rePTCA was performed at the site. RePTCA improved the stenosis to 50%, but ECG showed an inverted T wave in V3,4 and emergency CABG was performed, with the saphenous vein at LAD #8 and high lateral artery. Some authors have stated that CABG is not useful for long segmental coronary dissection, but we conclude that CABG should be definitely considered in such a case, because this procedure resolves pressure gradients at before-and-after entry and the bypass grafts will be never occluded whenever anastomosis (intima-adventitia-graft) is performed.

Angioplasty, Balloon, Coronary↗
PubMed1996

A new technique for exposing Calot's triangle during laparoscopic surgery: usefulness of extracorporeal lifting of the round ligament and gallbladder.

We developed a maneuver for holding and lifting the intraperitoneal organs from the extracorporeal side using a new instrument, the leading bar, by which we could guide the tape or the thread to the outside of the abdomen. In the case of cholecystolithiasis with a thickened wall or a stone stuck in the neck, we lifted the round ligament and gallbladder for better exposure of Calot's triangle, using the tape or thread through the abdominal wall to the extracorporeal side, and then clamped them with Kocher's forceps. With this technique, a good view of Calot's triangle was maintained so that the surgeon could expose the cystic duct easily and safely using both hands.

Cholangiography↗
PubMed1996

[Hepatic resection with "wrapping therapy" for advanced hepatocellular carcinoma uncontrolled by arterial embolization].

We report a 70-year-old male patient who had successful hepatic resection with "Wrapping therapy" for advanced hepatocellular carcinoma (HCC) uncontrolled by arterial embolization. His laboratory tests were as follows: Alb: 4.7 (g/dl), T. Bil:0.9 (mg/dl), ICG R15:26.8 (%), PT: > 100%, AFP:33 (ng/ml), HCV-Ab:(-), HBs-Ag:(-). Hepatic angiogram showed a 20 cm sized tumor in the left lobe and many large and small tumors in the right lobe. He received chemoembolization (TAE) five times during seven months. At the time of the fifth hepatic angiogram, TAE was assessed as ineffective because of the resulting collateral feeding arteries. Thus, he underwent left lobectomy, partial resection of the right lobe, and partial "Wrapping therapy" for the regions including foci supplied with parasitic branch. Afterwards, he had TAE two times. One year and five months after the procedure, he is still alive without signs of recurrence.

Aged↗
PubMed1996

[Verification of accuracy of several algorithms to quantitate left ventricular regional wall motion: a study using cine MR imaging with myocardial tagging].

To verify the accuracy of several algorithms used to quantitate left ventricular (LV) regional wall motion, five volunteers were examined by cine MR imaging with presaturation myocardial tagging in short-axis and 4-chamber sections. Three algorithms for the wall motion analysis, radial, centerline, and originally developed "modified-Hildreth" methods, were applied to the cine MR images, and dissociation of the end-systolic position of the tags estimated by each algorithm from the true position was examined. The modified-Hildreth method was comparable in accuracy to the other methods for estimating end-systolic tag position. Significantly worse estimation of the tag position by the three algorithms occurred in the 4-chamber section compared with the short-axis section (p < 0.001, 0.005), indicating difficulties in the wall motion analysis of "long-axis" LV images. Among the algorithms, the centerline method showed the highest accuracy of the estimation in the 4-chamber section, and the modified-Hildreth method was the best in the short-axis section. In the 4-chamber section, correction of the position of end-diastolic and end-systolic images around the luminal centroids improved the estimation (p < 0.01, 0.05). Tagging cine MR imaging was proved to be useful for determining the most suitable algorithm for quantitative wall motion analysis of LV images obtained from conventional angiocardiography and other imaging modalities.

Adult↗
PubMed1996

[Endoscopic mucosal resection for early esophageal cancer].

'xcently, a new method of endoscopic mucosal resection (EMR) for early esophageal cancer has been developed with the advance of the endoscopic equipment. There are three methods for EMR, one is 2 channel method, the second is EMR using over-tube and the third is EMR using cap-fitted panendoscope. Using a new type of over-tube (EEMR-tube) for EMR, which was designed by Makuuchi, esophageal mucosal lesions can be resected easily and certainly. It is thought that the indication of EMR for early esophageal cancer is the lesion limited to the muscularis mucosae. Large ulcers by endoscopic mucosal resection will disappear without any stenotic change within two months. We think that EMR is a useful technique for the treatment of early esophageal cancer because of keeping quality of life of patients and capability of histological findings.

Endoscopy↗
PubMed1996

[Endoscopic treatment in colorectal lesions--especially on endoscopic mucosal resection].

Protruded polyps can usually be treated with conventional polypectomy technique. Slightly elevated lesions without malignant findings are treated with hot biopsy method if they are small enough (less than 5 mm). In order to treat flat or slightly depressed lesions or slightly elevated lesions larger than 5 mm, endoscopic mucosal resection (EMR) technique has been invented. Cancers confined to the mucosa or those only minimally invading the submucosa can be completely removed with this method. However, if histological analysis of the resected specimen shows that the cancer invades the submucosa massively or permeating the vessels, surgical treatment should be added, because otherwise there would be risk of cancer residue or metastasis. When a lesion is suspected to be a submucosal cancer by endoscopic findings and pit pattern analysis from the beginning, then surgical resection is the treatment of choice. Laterally spreading tumors, especially the homogeneous granular type, are good indication for EMR or endoscopic piecemeal mucosal resection (EPMR). It is important to remove the lesion completely confirming that the resection margin is covered with normal pits.

Colectomy↗
PubMed1996

[Effect of FUT-187, oral serine protease inhibitor, on inflammation in the gastric remnant].

Excessive enterogastric reflux following partial gastrectomy is believed to be responsible for the cause of inflammation in the gastric remnant. We examined the effect of FUT-187, a synthetic serine protease inhibitor, on symptoms and endoscopic findings in 33 patients who were diagnosed endoscopically as postgastrectomy gastritis. Patients took 50 mg FUT-187 orally after each meal and at bedtime for 8 weeks. Before treatment, 30 patients (91%) suffered from several symptoms including regurgitation and/or bitter taste in the mouth (49%), epigastric pain (42%) and nausea (36%). From endoscopic observation, erythema was detected in 32 patients, edema in 23 patients and erosion and/or ulcer in 9 patients. After treatment the global improvement rating for subjective symptoms was 76.7% (23/30) and the improvement of endoscopic findings was 63.6% (21/33). Diarrhea was observed in one patient but could be easily controlled by discontinuation of the drug. Our results suggest that FUT-187 can be a useful drug for the treatment of postgastrectomy gastritis with its efficacy and safety.

Administration, Oral↗
PubMed1995

Short external loops as potential substrate binding site of gamma-aminobutyric acid transporters.

While the gamma-aminobutyric acid (GABA) transporter GAT1 exclusively transports GABA, GAT2, -3, and -4 also transport beta-alanine. Cross-mutations in the external loops IV, V, and VI among the various GABA transporters were performed by site-directed mutagenesis. The affinity of GABA transport as well as inhibitor sensitivity of the modified transporters was analyzed. Kinetic analysis revealed that a cross-mutation in which loop IV of GAT1 was modified to resemble GAT4 resulted in increased affinity to GABA from Km = 8.7 to 2.0 microM without changing the Vmax. A cross-mutation in loop VI, which swapped the amino acid sequence of GAT2 for GAT1, decreased the affinity to GABA (Km, 35 microM). These results suggest that loops IV and VI contribute to the binding affinity of GABA transporters. A substitution of three amino acids in loop V of GAT1 by the corresponding sequence of GAT3 resulted in beta-alanine sensitivity of its GABA uptake activity. These three amino acids in loop V seem to participate in the beta-alanine binding domain of GAT3. It is suggested that those three external loops (IV, V, and VI) form a pocket in which the substrate binds to the GABA transporters.

Amino Acid Sequence↗
PubMed1995

Up-regulation of protein serine/threonine phosphatase type 2C during 1 alpha,25-dihydroxyvitamin D3-induced monocytic differentiation of leukemic HL-60 cells.

Treatment with 20 nM 1 alpha,25-dihydroxyvitamin D3 (1,25(OH)2D3) caused a progressive increase in the activity of Mg(2+)-dependent protein serine/threonine phosphatase type 2C (PP2C) in subcellular fractions of HL-60 cells, whereas PP2C activity was relatively constant throughout all-trans retinoic acid-induced (1 microM) granulocytic differentiation. The increase in PP2C activity appeared to parallel the 1,25(OH)2D3-induced phenotypic and functional changes in HL-60 cells. Immunoblot and Northern blot analysis indicated that the increase in PP2C activity corresponded to the increased expression of PP2C protein, which was preceded by an increase in the level of mRNA for PP2C beta. No mRNA for PP2C alpha was detected in resting or 1,25(OH)2D3-stimulated HL-60 cells. These results suggest that the increased expression of PP2C is related with the 1,25(OH)2D3-induced monocytic differentiation of HL-60 cells.

Calcitriol↗
PubMed1995

Characterization of mouse nasal lymphocytes isolated by enzymatic extraction with collagenase.

A reproducible method for isolation of mouse nasal lymphocytes was developed. The cells were released from tissue fragments of dissected mouse nose by enzyme extraction with collagenase and separated by a stepwise Percoll gradient centrifugation. The partially purified nasal lymphocyte fraction from normal BALB/c mice contained CD4+ T cells (18-23%), CD8+ T cells (7-10%) and B cells (20-38%), when analysed with a FACScan fluorescence analyser. The ratio of T to B cells and that of CD4+ to CD8+ T cells in the nasal cell fraction were about twice as high as those in Peyer's path lymphocytes. The nasal lymphocyte fraction from the mice infected with influenza virus was then characterized. The nasal lymphocytes contained a twice larger number of CD4+ and a three times larger number of CD8+ T cells than those of normal mice 7 days after infection. They produced IFN-gamma which increased after infection. They contained the cells secreting influenza virus-specific IgA and IgG antibodies 4 weeks after infection. Moreover, the nasal lymphocytes from infected C3H mice lysed the virus infected-target cells. These results suggest that this method can successfully be used for investigating cellular dynamics of mucosal immunity in the upper respiratory tract of experimental animals.

Animals↗
PubMed1995

Cytochrome P450 2A1, 2E1, and 2C9 cDNA-expression by insect cells and partial purification using hydrophobic chromatography.

High-level expression of three cloned cytochrome P450 enzymes was accomplished using the baculovirus-insect cell expression system. The amount of enzyme expression was enhanced by cell infections in the presence of medium-supplements containing hemin and by growth in suspension cultures. Human cytochromes P450 2E1 and 2C9 and rat cytochrome P450 2A1 were partially purified from cell extracts using hydrophobic interaction and hydroxyapatite chromatography. The resulting enzymes were of estimated molecular masses similar to those reported previously and analyzed by PAGE. Reconstitution of enzyme activity resulted when the enzymes were incubated together with NADPH-cytochrome P450 reductase, phospholipid, NADPH, and appropriate substrates. The cytochrome P450 activity of the partially purified enzymes was comparable to that of the corresponding enzymes expressed in the vaccinia virus-Hep G2 system. These results provide evidence for a general means of obtaining cytochrome P450 enzymes for mechanistic, immunochemical, and biophysical investigations.

Animals↗
PubMed1995

Expression of autocrine motility factor receptor in human esophageal squamous cell carcinoma.

Autocrine motility factor and its receptor (gp78) have been shown to play an important role in tumor cell migration, invasion and metastasis. We have detected gp78 expression in buffered-formalin-fixed, paraffin-embedded sections of esophageal squamous cell carcinomas using an anti-gp78 monoclonal antibody (MAb), 3F3A, and examined the relationship between gp78 expression and clinicopathological and prognostic factors. In 55 of 101 (54%) patients, gp78 was detected in the tumor cells. The frequency of gp78-positive expression was significantly associated with tumor size, infiltrative growth, depth of invasion and lymph node metastasis. The cumulative survival rate of patients with gp78 was significantly lower than that of patients without gp78. Our results suggest that autocrine motility factor receptor (gp78) expression could be a useful biomarker for malignancy grading and prognosis in patients with esophageal squamous cell carcinoma.

Adult↗
PubMed1995

Establishment and characterization of cachexia-inducing and -non-inducing clones of murine colon 26 carcinoma.

To investigate the mechanism causing cachexia and its association with shorter patient survival, we cloned weight-loss-inducing and -non-inducing sublines of murine colon 26 carcinoma (colon 26). One clone, clone 20, induced substantial weight loss, wasting of adipose tissue and muscle, and hypoglycemia in mice with a minimum tumor burden of 0.3 g (2 g per 100 g body weight). Clone-20-bearing mice had a median survival of 24.5 days with average tumor weight of 0.4 g. In contrast, clone 5 induced neither severe weight loss, wasting of adipose tissue and muscle, nor hypoglycemia; clone-5-bearing mice survived for a median of 70 days with average tumor weight of 12 g. These results clearly indicate that shorter survival is associated with the degree of cachexia and is independent of tumor size. Using this pair of colon 26 clones, we examined mediators of cachexia. Neither TNF alpha, IL-1 alpha nor IFN gamma was detected in the serum of mice bearing either clone, while IL-6 was detected in mice bearing both clones by ELISA and a bioassay. Administration of anti-IL-6 monoclonal antibody (MAb) partially but significantly suppressed cachexia induction in clone-20-bearing mice. These results point to the involvement of IL-6 in experimental cachexia. However, our finding of the presence of IL-6 in the serum of mice bearing clone 5, which does not induce weight loss, clearly indicates that IL-6 is not solely responsible for the induction of cachexia.

Animals↗
PubMed1995

Molecular cloning and expression of mouse mg(2+)-dependent protein phosphatase beta-4 (type 2C beta-4).

A full-length complementary DNA (cDNA) clone (pTK-3) encoding an isoform of Mg(2+)-dependent protein phosphatase beta (MPP beta-4) was isolated for the first time from a mouse melanocyte cDNA library. It was strongly suggested that the mRNA corresponding to the pTK-3 insert was a splicing variant of a single pre-mRNA that also encodes MPP beta-1 and -2 (T. Terasawa, T. Kobayashi, T. Murakami, M. Ohnishi, S. Kato, O. Tanaka, H. Kondo, H. Yamamoto, T. Takeuchi, and S. Tamura, 1993, Arch. Biochem. Biophys. 307, 342-349). The amino acid sequence of MPP beta-4 differed from those of MPP beta-1 and -2 only at the carboxyl terminal region. Analysis by reverse transcriptase polymerase chain reaction (RT-PCR) revealed that MPP beta-4 mRNA was expressed only in testis and intestine and not in other mouse tissues tested. Specific expression of the mRNA signals of two other isoforms of MPP beta, MPP beta-3 and -5 (a novel isoform), in testis and intestine was also demonstrated by the RT-PCR. The carboxyl terminal region of MPP beta-5 was found to have a chimera structure composed of part of MPP beta-1 and part of MPP beta-3. The recombinant MPP beta-3 and -4 and the putative MPP beta-5 expressed in Escherichia coli cells exhibited Mg(2+)-dependent and okadaic acid-insensitive protein phosphatase activities. It was demonstrated that the mRNA expression levels of MPP beta-3, -4, and -5 alter according to the maturation of mouse testis. These results suggest that the complex structure of MPP beta isoforms and their tissue- and developmental stage-specific expression reflect the variety of their physiological functions.

Alternative Splicing↗
PubMed1995

Arterial-injection chemotherapy for hepatocellular carcinoma using monodispersed poppy-seed oil microdroplets containing fine aqueous vesicles of epirubicin. Initial medical application of a membrane-emulsification technique.

BACKGROUND: Iodized poppy-seed oil (IPSO) has a property of depositing itself selectively in the cells of hepatocellular carcinoma (HCC). A mixture of anticancer agents and IPSO has been used widely because IPSO accumulates in tumors, but its usefulness appears limited because the anticancer agents become separated easily from IPSO and do not remain in the tumor. The authors prepared a long term inseparable, water-in-oil-in-water emulsion (W/O/W) for use in arterial-injection therapy for patients with HCC and evaluated its clinical usefulness. METHODS: The W/O/W was prepared by a membrane-emulsification technique using a controlled pore glass with 10.6-microns pores. From December 1992 to January 1994, the W/O/W containing 8-60 mg of epirubicin was applied to the hepatic arterial-injection therapy for 21 patients with HCC to determine its antitumor and side effects. RESULTS: After arterial infusions with W/O/W, an evident antitumor effect was observed in all 13 patients treated with W/O/W containing 40 mg or more of epirubicin with or without gelatin-sponge particles used simultaneously. In the group treated with the W/O/W containing a high dose (40 mg or more) of epirubicin, even though the gelatin-sponge particles were not used, tumor size was reduced in six of seven patients, and a 50% or greater decrease of initial alpha-fetoprotein (AFP) levels within 14 days was observed in all four patients who showed abnormal levels of serum AFP before treatment. One partial necrosis and two complete necroses of three resected tumors were confirmed histopathologically. Fever (in all patients), nausea (in two), pain in the right upper quadrant of the abdomen (in two), and slight cough (in one) were noted as minor side effects. CONCLUSIONS: To the authors' knowledge, this is the first clinical trial using this emulsion prepared by the membrane-emulsification technique. Emulsification using a fine-pore glass membrane of equal pore size (i.e., controlled-pore glass membrane) is a new technique for preparing lipid microdroplets of equal size (monodispersed) containing aqueous fine microdroplets to form W/O/W: This technique of chemoembolization can be used to treat patients with HCC.

Aged↗
PubMed1995

Positive correlation of plasma transforming growth factor-beta 1 levels with tumor vascularity in hepatocellular carcinoma.

Transforming growth factor-beta 1 (TGF-beta 1) has been implicated in tumor progression by promoting angiogenesis or suppressing immune system. We reported previously that transforming growth factor-beta 1 (TGF-beta 1) is overproduced by human hepatocellular carcinoma (HCC) tissues and that plasma TGF-beta 1 levels are elevated in patients with HCC. In the present study, we investigated the relationship between plasma TGF-beta 1 levels and tumor vascularity as assessed by conventional celiac angiography in 17 patients with HCC. The plasma TGF-beta 1 level did not correlate with tumor size or underlying liver disease. However, we found that plasma TGF-beta 1 levels correlated positively with the tumor vascularity. These results suggest that excessive TGF-beta 1 production may contribute to tumor angiogenesis in HCC.

Aged↗
PubMed1995

No detectable cytomegalovirus and Epstein-Barr virus genomes in the pancreas of recent-onset IDDM patients.

Viral infection is assumed to trigger or exacerbate autoimmune responses against pancreatic beta cells leading to the development of insulin-dependent diabetes mellitus (IDDM). We therefore examined by polymerase chain reaction the presence of two candidate viruses, cytomegalovirus and Epstein-Barr virus, in IDDM pancreases. Pancreas tissues were obtained by biopsy under laparoscopy from 16 recent-onset IDDM patients: age 17-53 years; disease duration 0-7 months; six had flu-like symptoms before onset. Frozen sections were made and subjected to DNA amplification. DNA samples were prepared from the frozen sections and polymerase chain reaction was performed using primers specific to cytomegalovirus, Epstein-Barr virus and control gene for HLA-DP. Cytomegalovirus- and Epstein-Barr virus-infected cells were used for positive control. Southern blot analysis could detect cytomegalovirus DNA from as few as 2 x 10(-1) cytomegalovirus-infected cells and Epstein-Barr virus DNA from two Epstein-Barr virus-infected cells. This highly sensitive analysis, however, could not detect cytomegalovirus or Epstein-Barr virus genomes in pancreases of recent-onset IDDM. A single copy human gene (HLA-DP) was amplified from all IDDM pancreases indicating that DNA amplification was performed without inhibition. We conclude that cytomegalovirus or Epstein-Barr virus genomes are unlikely to exist in pancreas biopsy specimens of recent-onset IDDM patients.

Adolescent↗