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Biomedical subjects

K Yasui

Publications and source records attributed to K Yasui.

At least 199 records · Page 11Linked to original sources
PubMed1996

Surgical treatment of Borrmann type IV gastric carcinoma: relevance of lymphadenectomy in improving survival.

BACKGROUND: Borrmann type IV gastric carcinoma carries a poor prognosis, even if curatively resected. The benefit of a lymphadenectomy is unknown. STUDY DESIGN: A retrospective study was designed to evaluate whether improvements have been made in the treatment of type IV gastric carcinoma over the past decade. The 345 patients with type IV carcinoma who underwent laparotomy within a recent 16-year period were split into two groups: one group of patients who underwent laparotomy between 1977 and 1985, and the other between 1986 and 1992. Survival data were compared between these two groups and prognostic factors for type IV gastric carcinoma were assessed by multivariate analysis. RESULTS: A significant difference in survival was observed between the groups, both of which underwent curative resection, despite a lack of difference in background factors. The improvement was more prominent among patients with nodal metastases and insignificant among patients without nodal metastases. Multivariate analysis identified nodal metastasis as a major independent prognostic factor. CONCLUSIONS: An improvement in outcome was presumably achieved through extended lymphadenectomy. However, the survival rate remains unsatisfactory, and further advances in the treatment of this disease are needed.

Adenocarcinoma↗
PubMed1996

[Thrombotic thrombocytopenic purpura after administration of ticlopidine].

On June 29, 1995, a 49-year-old man was admitted with acute onset of fever, petechiae on his legs, and mental confusion He had suffered hypertension since 6 months previously and was on nicardipine (60 mg/day), ifenprodil (60 mg/day) and ticlopidine (300 mg/day). He had been on ticlopidine for 4 weeks and on the other drugs for 6 months. Soon after admission he had frequent grand mal seizures and needed mechanical ventilation. A diagnosis of TTP was made. He was treated with plasmapheresis (50 ml/kg per day), aspirin 81 mg/day and dipyridamole 300 mg/day. On the sixth day his mental status returned to normal. He recovered gradually from microangiopathic hemolytic anemia, thrombocytopenia and elevated serum creatinine. We reviewed the literature and discussed the possible mechanism of TTP related to the use of ticlopidine.

Humans↗
PubMed1996

[Percutaneous CT guided bone biopsy in patients with suspected bone neoplasm].

Bone biopsy is necessary for the diagnosis of ambiguous skeletal lesions. Although several merits of computed tomography (CT)-guided percutaneous needle biopsy have been documented, few radiologists have performed this procedure in Japan. We performed this procedure with a newly introduced bone biopsy needle (OSTYCUT, angiomed, Karlsruhe, Germany) under CT guidance and evaluated the results. CT-guided bone biopsy (pelvic[n = 11]vertebral[n = 10], femoral[n = 1], sternal[n = 1]) was performed in 19 consecutive patients. Seventeen patients were suspected metastatic disease, and the others were suspected primary bone tumor. All biopsies but one were diagnostic. Malignancy was proved in 11 lesions. Three patients with prostatic carcinoma were proved to show no malignancy of bone lesions after a series of hormonal and chemotherapies. In one patient with both malignant mesothelioma and cervical carcinoma, the biopsy specimen from thoracic vertebra proved metastasis from mesothelioma. CT-guided bone biopsy is useful to evaluate the presence of malignancy and the effect of therapy for it, and to determine the primary site.

Adult↗
PubMed1995

TNF alpha receptor expression in rat cardiac myocytes: TNF alpha inhibition of L-type Ca2+ current and Ca2+ transients.

Tumor necrosis factor-alpha (TNF alpha) is a potentially powerful anti-neoplastic agent; however, its therapeutic usefulness is limited by its cardiotoxic and negative inotropic effects. Accordingly, studies were undertaken to gain a better understanding of the mechanisms of TNF alpha-mediated cardiodepression. Single cell RT-PCR, [125I]TNF alpha ligand binding and Western immunoblotting experiments demonstrated that rat cardiac cells predominantly express type I TNF alpha receptors (TNFRI or p60). TNF alpha inhibited cardiac L-type Ca2+ channel current (ICa) and contractile Ca2+ transients. Thus, it is possible that the negative inotropic effects of TNF alpha are the result of TNFRI-mediated blockade of cardiac excitation-contraction coupling.

Animals↗
PubMed1995

Incidence, diagnosis and significance of multiple gastric cancer.

Of 2790 patients with gastric cancer undergoing surgery between January 1978 and December 1993, 160 (with 356 neoplastic lesions) had synchronous multiple cancer. Of these lesions 271 (76 percent) were early cancers. Only 85 (53 percent) of the 160 patients were diagnosed before operation as having multiple cancer; 69 further patients (43 percent) were diagnosed during the course of the operation. Small flat (IIb) and depressed (IIc) type lesions had a propensity to be missed before operation. The incidence of multiple cancer was relatively low, indicating that several microscopic lesions might have been overlooked in this series. There has, however, only been one patient (1 percent) with subsequent cancer of the gastric remnant of 126 with multiple cancer and postoperative gastric remnants over the past 16 years. This might be because of co-resection of unrecognized lesions by distal gastrectomy in 68 percent of the patients. Alternatively some microscopic cancers might not invariably be destined to grow into clinically significant lesions over 10 or more years.

Female↗
PubMed1995

Monokine production by peripheral whole blood in chronic hepatitis C patients treated with interferon.

Using our scoring system, we studied the production of monokines (interleukin-1 alpha, interleukin-1 beta, tumor necrosis factor-alpha, and interleukin-6) by lipopolysaccharide-stimulated peripheral whole blood in 34 patients with chronic hepatitis C during the interferon-alpha/beta therapy. It decreased in 25.7% (9/35 group A), fluctuated in 60.0% (21/35, group B), and increased in 14.3% (5/35, group C). The patients in group A were younger than those in group B (P < 0.05). The histological grade of injury was milder in group A than in group B or C. The rate of sustained response was 66.7% (6/9) in group A, 19.0% (4/21) in group B, and 40.0% (2/5) in group C(P = 0.0184, group A versus group B). In summary, monokine production by peripheral whole blood varied during interferon therapy for chronic hepatitis C patients. No significant change was noted in 60% of the patients. However, patients with decreased monokine production were younger, with a mild histological grade, and likely to respond to the interferon therapy.

Adult↗
PubMed1995

Simple fluorescent enzyme immunoassay for detection and quantification of hepatitis C viremia.

The viral load of hepatitis C virus, as reflected by hepatitis C virus viremia, has been shown to have important clinical implications. In this study the hepatitis C virus core protein level in serum was evaluated for the detection and quantification of hepatitis C virus viremia. Hepatitis C virus core protein in serum was detected using a simple and sensitive fluorescent enzyme immunoassay. Hepatitis C virus core protein was quantitated in 100 healthy subjects, 258 patients with hepatitis C virus infection and 108 patients with non-hepatitis-C-virus-related chronic liver diseases. HCV-RNA was determined using the branched DNA (bDNA) assay and reverse-transcription polymerase chain reaction. The detection limit of this fluorescent enzyme immunoassay was found between 10(4) - 10(5) copies/ml HCV-RNA equivalent. There was a good correlation between the core protein and bDNA assay results (p <0.01). Hepatitis C virus core protein was detected in 81% of patients with hepatitis C virus infection (acute hepatitis 4/5, chronic hepatitis 85/104, cirrhosis 64/73 and hepatocellular carcinoma 56/76) but in none of the healthy subjects and patients with non-hepatitis C virus chronic liver diseases. The amount of hepatitis C virus core protein in patients with hepatitis-C-virus-related hepatocellular carcinoma was lower compared to chronic hepatitis and cirrhosis (p <0.05). All 26 patients treated with interferon-alpha showed parallel changes between HCV-RNA and core protein levels. This fluorescent enzyme immunoassay is simple and quick (assay time <3 h) with sensitivity at least matching the bDNA assay. Similar levels of hepatitis C virus core protein were detected in patients with chronic hepatitis and cirrhosis, but patients with hepatocellular carcinoma tended to have a lower level of hepatitis C virus core protein.

DNA, Viral↗
PubMed1995

Isolation of thermolabile mutant RNA polymerase II from fission yeast Schizosaccharomyces pombe with mutations in the subunit 3 gene.

Subunit alpha of prokaryotic RNA polymerases plays key roles in protein-protein contacts for both subunit assembly and transcription activation. To gain an insight into the roles of subunit 3, the eukaryotic homologue of alpha, temperature-sensitive mutants of the fission yeast, Schizosaccharomyces pombe, have been isolated after transformation of the mutagenized rpb3 gene encoding mutant subunit 3 of RNA polymerase II. A total of 68 ts mutants were classified into two groups: mutants comprising one group ceased growing immediately after a temperature up-shift, while mutants comprising the other group exhibited delayed growth arrest at high temperatures. RNA polymerase II partially purified from Ts54, one of the group 2 mutants, was thermolabile in vitro, as measured by a non-specific transcription assay. This mutant carries double mutations in domain A of subunit 3, and thus can be used as a reference mutant of RNA polymerase II.

Cloning, Molecular↗
PubMed1995

Inhibitory action of SR33557 on L-type calcium current in single ventricular myocytes of rat.

1. The effect of SR33557 on L-type Ca2+ currents in rat ventricular myocytes was investigated by use of the whole-cell patch-clamp technique. 2. SR33557 inhibited Ca2+ current (ICa) in a concentration-dependent manner without change in the current-voltage relationship. 3. The inhibitory effect of SR33557 on ICa was dependent on the holding potential (Vh). The IC50 values were estimated to be 2.2 x 10(-8) M at Vh = -50 mV and 9.0 x 10(-6) M at Vh = -80 mV. SR33557 (10(-7) M) shifted the steady state inactivation curve of ICa toward more negative potentials. Thus, the affinity of the drug for inactivated channels was considerably higher than for resting channels. 4. Blockade of ICa by SR33557 was both tonic and use-dependent. 5. The time constant of onset of block was 36.4 s at -50 mV and 41.9 +/- 11.1 s at -40 mV. 6. The time course of unblock was voltage-dependent. The time constant declined from 400.7 +/- 68.1 is at -50 mV to 5.2 +/- 1.2 s at -80 mV. 7. The rate of block of ICa was related to the number of openings per unit time and to the amount of time spent depolarized. The affinity of drug for open channels was considered to be similar to that for inactivated channels. 8. These results suggest that SR33557 inhibits L-type Ca2+ current through binding to both open and inactivated channels in rat ventricular myocytes.

Animals↗
PubMed1995

Organic solvent-tolerant bacterium which secretes an organic solvent-stable proteolytic enzyme.

A bacterial strain which can be grown in a medium containing organic solvents and can secrete a proteolytic enzyme was isolated and identified as Pseudomonas aeruginosa. The strain was derived by the following two-step procedures: high proteolytic enzyme producers were first isolated by the usual method, and then the organic solvent-tolerant microorganism was selected from these high-rate proteolytic enzyme producers. The proteolytic activity of the supernatant of the culture was stable in the presence of various organic solvents. The stability of the enzyme in the presence of organic solvents, of which the values of the logarithm of the partition coefficient (log P) were equal to or more than 3.2, was almost the same as that in the absence of organic solvents. It is expected that both the solvent-tolerant microorganism and the solvent-stable enzyme produced by this strain can be used as catalysts for reactions in the presence of organic solvents.

Journal Article↗
PubMed1995

Controlled release by Ca(2+)-sensitive recombinant human tumor necrosis factor-alpha liposomes.

Recombinant human tumor necrosis factor-alpha (rHuTNF) was entrapped in liposomes consisting of Egg phosphatidylcholine (EggPC) alone, EggPC-egg phosphatidic acid (EggPA) or EggPC-egg phosphatidylglycerol (EggPG). These liposomes, stored in vials, were stable for a month at 4 degrees C. The rHuTNF release from the liposomes were examined in rat plasma and phosphate buffered saline (PBS). rHuTNF was released from the liposomes containing EggPA in rat plasma. The release of rHuTNF was inhibited by EDTA and was induced in PBS containing CaCl2, indicating that this release is induced by Ca2+ ion in the plasma. The release of rHuTNF was promoted by an increase of the EggPA content. In conclusion, we could obtain stable liposomes in a vial and this liposome could immediately release rHuTNF in the rat plasma. Furthermore we were able to control the release rate of rHuTNF from these liposomes.

Animals↗
PubMed1995

Cloning and nucleotide sequence of the calmodulin-encoding gene (cmdA) from Aspergillus oryzae.

A cDNA and genomic gene encoding calmodulin were isolated from Aspergillus oryzae using a part of the calmodulin gene from A. nidulans as a hybridization probe. The gene was in a 3.4-kb SphI fragment and Southern-blot analysis of genomic DNA suggested the existence of a single copy of the calmodulin gene in A. oryzae. The nucleotide sequence analysis showed that the gene consists of five introns and six exons. Although the nucleotide sequence homology with that of A. nidulans was not so high (68%), the deduced amino acid sequence was 100% and 84% identical with calmodulin of A. nidulans and chicken, respectively. The cDNA encoding A. oryzae calmodulin was expressed under the control of the GAL1 promoter in the calmodulin null mutant (cmd1) of yeast, Saccharomyces cerevisiae, and could function as a calmodulin gene.

Amino Acid Sequence↗
PubMed1995

Hepatic arteriography in patients with hepatocellular carcinoma: change in findings caused by balloon occlusion of tumor-draining hepatic veins.

OBJECTIVE: A previous study suggested that temporary occlusion of a segment of the hepatic vein causes an increase in arterial flow and retrograde portal flow in the occluded segment. Such occlusions might improve the efficacy of arterial infusion therapy. Accordingly, we studied the change in blood flow visible on hepatic arteriograms when a segment of the hepatic vein is temporarily occluded in patients with hepatocellular carcinoma. MATERIALS AND METHODS: The study group consisted of 24 patients with nodular-type hepatocellular carcinoma. Conventional hepatic arteriography was followed by hepatic arteriography performed using a balloon catheter to occlude the hepatic vein that was most closely associated with the tumor. Visualization of the tumor-draining veins, portal vein branches, the degree of tumor vascularity, and the density of the hepatogram on the hepatic arteriogram were retrospectively compared before and during venous occlusion. The veins were evaluated visually; an increase of tumor vascularity was defined as an increase in the number of countable tumor vessels during occlusion, and a dense hepatogram was considered to be a definite sinusoidgram induced by venous occlusion. RESULTS: Conventional hepatic arteriography showed the tumor-draining veins to be branches of the portal vein in only two of the 24 patients (8%). Hepatic arteriography during venous occlusion, however, showed the tumor-draining veins to be branches of the portal vein in four of the patients (17%). An increase in the degree of tumor vascularity with venous occlusion was observed only in a patient with an initial arteriohepatic vein shunt. Dense hepatogram and hepatofugal opacification of the portal vein branches in the occluded, tumor-bearing segment were obtained in 10 patients (42%). Eight of these did not have liver cirrhosis, whereas all of the remaining 14 patients did (p < .001). CONCLUSION: Our results suggest that occlusion of a segment of the hepatic vein may be useful during arterial infusion of hepatocellular carcinoma.

Adult↗
PubMed1995

Collagen fibrils in the odontoblast layer in the teeth of the rat and the house shrew, Suncus murinus, by scanning electron microscopy using a maceration method.

It is not well known whether there are gaps in the tight junctions between odontoblasts and whether the fluid flows from the pulp to the predentin through these gaps. The collagen fibrils in the odontoblast layer were investigated using a maceration method in order to show the existence of the gaps between tight junctions of the odontoblasts. The mandibles containing teeth of the rat and the house shrew were digested by NaOH maceration and revealed the architecture of the collagen fibrils under scanning electron microscopy. The collagen fibrils went from the pulp, through the odontoblast layer, and were woven into the collagen network of the predentin in all teeth used in this study. Thick bundles of collagen were seen in the odontoblast layer at the pulp horn of the rat molars. Because there are many collagen fibrils in the odontoblast layer, it is considered that the tight junction of the odontoblast is of the discontinuous type.

Alveolar Process↗
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

Evaluation of the effect of pancreatic resection in advanced pancreatic cancer with special reference using hospital-free survival as a measure of quality of life.

Comparisons of surgical procedures and the identification of prognostic factors in pancreatic cancer were carried out on 158 patients who underwent surgery in Aichi Cancer Center from 1975 to 1991 for advanced pancreatic ductal adenocarcinoma. Survival and 'hospital-free survival (HFS), which we consider the best general means of measuring quality of life (QOL) in such severe and often fatal disease, were identified as primary end points, and the effect of pancreatectomy, compared with palliative surgery (by-pass operation, etc.) for TNM Stages III and IV pancreatic cancer was evaluated. Both survival and HFS were significantly longer in the group of patients who underwent pancreatectomies (R group, n 25) compared to the group without pancreatic resection (NR group, n 35) in Stage III cases. In Stage IV cases, however, no significant difference was observed between the R (n 12) and NR (n 86) groups. From these results, we conclude that an extensive pancreatic resection against Stage III pancreatic cancer may improve prognosis. For Stage IV pancreatic cancers, however, aggressive surgery might not always be beneficial either for survival or for QOL.

Carcinoma, Ductal, Breast↗
PubMed1994

Signal transduction pathway in human polymorphonuclear leukocytes for chemotaxis induced by a chemotactic factor. Distinct from the pathway for superoxide anion production.

The tyrosine kinase inhibitors erbstatin and herbimycin A inhibited the chemotactic response to FMLP (2 x 10(-7) M) and the superoxide anion (O2-) production stimulated by FMLP (1 x 10(-6) M) in human polymorphonuclear leukocytes (PMN) in similar manners. These compounds also inhibited phospholipase D (PLD)-catalyzed breakdown of phosphatidyl choline, suggesting a possible link between tyrosine kinase and PLD. In the presence of propranolol (phosphatidic acid (PA) phosphohydrolase inhibitor), or ethanol, the activation of PLD results in the modulation of PA and/or diglyceride (DG) generation, producing an irregularity in O2- production. However, PMN motility was not affected in these conditions. These results suggest that PLD is a downstream effector of FMLP-induced tyrosine kinase activation that leads to activation of the PMN superoxide release but not to chemotactic migration. In contrast, the tyrosine kinase inhibitors did not inhibit inositol 1,4,5-triphosphate generation and increase of intracellular concentration of free calcium. Furthermore, a protein kinase C inhibitor, 1-(5-isoquinolinesulfonyl)-2-methylpiperazine dihydrochloride (H-7), did not affect the migration of PMN and the activation of PLD induced by FMLP at concentrations of less than 50 microM. These results support the premise that there is a specific signaling pathway for chemoattractant-induced PMN locomotion.

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