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Biomedical subjects

K Matsui

Publications and source records attributed to K Matsui.

At least 217 records · Page 12Linked to original sources
PubMed1997

Multivariate analysis of prognostic factors in patients with ovarian cancer stage I and II.

OBJECTIVE: To evaluate prognostic factors such as surface capsular invasion, rupture of the capsule and intraperitoneal cytology in patients with stage I or II ovarian cancer. METHOD: Multivariate analysis was performed using 11 clinicopathologic prognostic factors obtained from 183 cases of stage I and II ovarian cancer, which had been surgically treated between 1983 and 1993. RESULTS: Significant prognostic factors determined by the Kaplan-Meier method were rupture and invasion of the capsule in stage II ovarian cancer. Multivariate analysis showed that spontaneous rupture of the capsule was the only significant factor, and intrapelvic cytology was an important factor without significance. Although capsular rupture caused by the surgeon showed poor prognosis by the Kaplan-Meier method, no significance was observed for this factor by multivariate analysis. CONCLUSION: Multivariate analysis showed that capsular rupture caused by the surgeon did not affect the prognosis in stage I and II ovarian cancer.

Adenocarcinoma↗
PubMed1997

Two components of transmitter release in retinal bipolar cells: exocytosis and mobilization of synaptic vesicles.

Ca2+-transmitter release coupling was examined using bipolar cells with large presynaptic terminals dissociated from the goldfish retina. Presynaptic Ca2+ current (I(Ca)) was recorded under the whole-cell voltage clamp. Release of excitatory amino acid transmitter was simultaneously monitored as the current through N-methyl-D-asperate (NMDA) receptors of reporter cells or as the membrane capacitance (C(m)) change associated with exocytosis. When I(Ca) was activated by a long depolarizing pulse, a double-peaked transmitter-induced current (I(tr)) was elicited in reporter cells. The rapid component of I(tr) was evoked immediately after the onset of depolarization, and was affected only slightly by intracellularly applied Ca2+ chelators. The delayed slow component of I(tr) was elicited during depolarization once a fixed amount of Ca2+ was accumulated in presynaptic terminals, and its appearance was suppressed or retarded by Ca2+ chelators. Two components of transmitter release were also recognized by monitoring C(m) changes elicited by the activation of I(Ca). These results suggest that bipolar cells have at least two pools of synaptic vesicles; a small, immediately releasable pool and a large releasable pool. The rapid and the delayed slow components of transmitter release may reflect exocytosis and mobilization of synaptic vesicles, respectively.

Animals↗
PubMed1997

Fagomine isomers and glycosides from Xanthocercis zambesiaca.

50% aqueous MeOH extracts from the leaves and roots of Xanthocercis zambesiaca (Leguminosae) were subjected to various ion-exchange column chromatographic steps to give fagomine (1), 3-epi-fagomine (2), 3,4-di-epi-fagomine (3), 3-O-beta-D-glucopyranosylfagomine (4), and 4-O-beta-D-glucopyranosylfagomine (5). Their structures were determined by spectroscopic analyses, particularly by extensive 1D and 2D NMR studies. Compounds 3 and 4 are new natural products. Compound 1 is a good inhibitor of isomaltase and certain alpha- and beta-galactosidases. Whereas 2 is a more potent inhibitor of isomaltase and beta-galactosidases than 1, it does not inhibit alpha-galactosidase. Compounds 3-5 exhibited no significant inhibition against the glycosidases used.

Animals↗
PubMed1997

CODE chemotherapy with and without granulocyte colony-stimulating factor in small-cell lung cancer.

Sixty-three patients with extensive-stage small-cell lung cancer were randomized to receive either cyclophosphamide, vincristine, doxorubicin and etoposide (CODE) alone or CODE plus recombinant human granulocyte colony-stimulating factor (rhG-CSF). rhG-CSF administration in support of CODE chemotherapy resulted in increased mean total received dose intensity for all drugs (P = 0.03) with a significant improvement in survival (P = 0.004).

Adult↗
PubMed1997

Absorption, distribution, metabolism and excretion of a new, 14C-labelled oxazolidinone MAO-A inhibitor in rat and dog.

1. After oral administration of 14C-labelled (5R)-3-[2-((1S)-3-cyano-1-hydroxypropyl)benzothiazol-6-yl]-5-metho xymethyl -2-oxazolidinone (E2011) at a dose of 1 mg/kg, the blood level of radioactivity reached a maximum concentration (Cmax) of 0.545 microgram eq./ml after 0.25 h in the rat and of 0.900 microgram eq./ml after 0.5 h in the dog. In dog plasma, Cmax for radioactivity and unchanged E2011 were 0.862 microgram eq./ml and 0.650 microgram/ml respectively with corresponding Tmax (time at Cmax) of 0.75 and 0.25 h. The unchanged drug in dog plasma was below the detection limit (5 ng/ml plasma) after 24 h. 2. The tissue levels of radioactivity were measured at 0.25 (Tmax), 6, 24, and 168 h after administration to the rat and at 0.5 (Tmax), 24, and 168 h in the dog. The radioactivity was distributed in all tissues examined at Tmax in the rat and dog. The radioactivity levels of the cerebral cortex in the rat and dog were 26 and 36% of the plasma level at Tmax. The radioactivity in tissues decreased at almost the same rate as that in plasma. Plasma protein binding of the unchanged drug in the rat in vitro were about 70% in the range of 0.1-10 micrograms/ml, and those in the dog were about 45% in the same concentration range. 3. Cumulative excretion of radioactivity in the rat was 74.5% in urine and 22.5% in faeces after 7 days. In the dog, 55.5 and 36.5% of the radioactivity administered were excreted in urine and faeces respectively after 7 days. The biliary excretion of radioactivity in the cannulated rat was 23.0% within 48 h. 4. In tlc analysis of plasma and tissues of the rat and dog, the radioactivity for the unchanged drug was much higher than metabolites. In tlc analysis of urine, the same metabolites were detected in the rat and dog, and the radioactivity of a metabolite, IM1, was the highest in the both animals. Eight metabolites were detected in the plasma, tissues and excreta of the rat, and four metabolites in the dog. 5. In conclusion, the absorption, distribution, metabolism and excretion of 14C-labelled E2011 in the rat and dog have been established, and only minor differences were observed between these species.

Absorption↗
PubMed1997

Transcutaneous needle biopsy of the lung.

PURPOSE: To evaluate the usefulness of transcutaneous needle biopsy (TCNB). MATERIAL AND METHODS: From May 1988 to December 1994, we performed TCNB under fluoroscopic control in 408 patients with mass lesions of the peripheral lung. The Surecut needle (1.5 mm) was selected mainly because of its ability to obtain specimens large enough for histological examination. Of the 408 patients, 286 had had previous bronchofiberscopic examinations but no definite diagnosis had been reached. RESULTS: A definite diagnosis was obtained by TCNB in 305 (74.7%) of 408 cases (251 malignant neoplasms, 54 benign lesions). In malignant neoplasms, the pathological diagnosis based on cytology and histology together was more reliable than that based on cytology alone. Although the complications of this procedure (such as pneumothorax) were within the range of acceptability, care should be taken to avoid air embolism and the seeding of cancer cells along the needle tract. CONCLUSION: TCNB with the Surecut needle is a useful procedure with relatively low risk.

Biopsy, Needle↗
PubMed1997

The effects of calystegines isolated from edible fruits and vegetables on mammalian liver glycosidases.

The polyhydroxylated nortropane alkaloids called calystegines occur in many plants of the Convolvulaceae, Solanaceae, and Moraceae families. Certain of these alkaloids exhibit potent inhibitory activities against glycosidases and the recently demonstrated occurrence of calystegines in the leaves, skins, and sprouts of potatoes (Solanum tuberosum), and in the leaves of the eggplant (S. melongena), has raised concerns regarding the safety of these vegetables in the human diet. We have surveyed the occurrence of calystegines in edible fruits and vegetables of the families Convolvulaceae, Solanaceae, and Moraceae by GC-MS. Calystegines A3, B1, B2, and C1 were detected in all the edible fruits and vegetables tested; sweet and chili peppers, potatoes, eggplants, tomatoes, Physalis fruits, sweet potatoes, and mulberries. Calystegines B1 and C1 were potent competitive inhibitors of the bovine, human, and rat beta-glucosidase activities, with Ki values of 150, 10, and 1.9 microM, respectively for B1 and 15, 1.5, and 1 microM, respectively, for C1. Calystegine B2 was a strong competitive inhibitor of the alpha-galactosidase activity in all the livers. Human beta-xylosidase was inhibited by all four nortropanes, with calystegine C1 having a Ki of 0.13 microM. Calystegines A3 and B2 selectively inhibited the rat liver beta-glucosidase activity. The potent inhibition of mammalian beta-glucosidase and alpha-galactosidase activities in vitro raises the possibility of toxicity in humans consuming large amounts of plants that contain these compounds.

Animals↗
PubMed1997

Comparative studies of the bactericidal, morphological and post-antibiotic effects of arbekacin and vancomycin against methicillin-resistant Staphylococcus aureus.

Arbekacin, an aminoglycoside antibiotic, has antibacterial activity against both Gram-positive and Gram-negative bacteria and is stable in the presence of aminoglycoside-inactivating enzymes produced by methicillin-resistant Staphylococcus aureus (MRSA). In this report, the antibacterial activity of arbekacin was compared with that of vancomycin, a glycopeptide antibiotic that also has potent antibacterial activity against MRSA. Arbekacin showed concentration-dependent bactericidal activity against MRSA strain 1936 (0.5-2 x MIC), but vancomycin showed only slight bactericidal activity, even at high concentrations of 19 x MIC. Arbekacin showed a longer post-antibiotic effect (2.3-3.8 h) than vancomycin (0-1.3 h) against MRSA strain 1936. Arbekacin induced marked morphological changes at 0.5 x MIC and the changes remained for 2 h after removal of the agent. When exposed to 0.5 x MIC of vancomycin, no notable morphological change was observed in the treated cells. Since arbekacin has broad-spectrum activity, these findings suggest that it may be a useful agent against MRSA infection, especially for polymicrobial MRSA infection with Gram-negative bacilli, such as Pseudomonas aeruginosa.

Aminoglycosides↗
PubMed1997

A purified protein from Salmonella typhimurium inhibits high-affinity interleukin-2 receptor expression on CTLL-2 cells.

Previously, we have demonstrated that the immunosuppression induced by the purified substance Salmonella typhimurium-derived inhibitor of T-cell proliferation (STI) involves T-cell non-responsiveness to interleukin-2 (IL-2). In the present study, it was found that STI inhibited the growth of CTLL-2 cells, which are an IL-2-dependent cytotoxic T-cell line. Analysis of IL-2 receptor (IL-2R) function showed that STI inhibited high-affinity receptor expression and internalization by CTLL-2 cells. Furthermore, FACS analysis demonstrated that STI inhibited both beta chain and gamma chain expression of IL-2R on the cells. These results suggest that the suppression of T-cell proliferation induced by STI results from a defect in IL-2R function.

Animals↗
PubMed1997

Electrical and mechanical modulations by oxygen-derived free-radical generating systems in guinea-pig heart muscles.

The effects of free-radical generating systems and angiotensin-converting enzyme (ACE) inhibitors on the action potentials and contractile force in guinea-pig cardiac muscles were examined using conventional microelectrode and whole-cell voltage-clamp methods at 36 degrees C. Hydrogen peroxide (30-100 microM) prolonged 50%, 75% and 90% repolarization of action-potential duration (APD) approximately 15-25 min after its application. But the longer exposure reversed the APD shortening in a concentration-dependent manner. Other action-potential parameters were not altered to a significant extent. The contractile force was increased. Longer exposure inhibited the enhanced force (but it was still larger than control). The effects on the spontaneous action potential from right atrial muscle were almost the same. In whole-cell voltage-clamp experiments, H2O2 (100 microM) inhibited L-type Ca2+ current and enhanced delayed rectifier K+ current. The effects of light-activated rose bengal (10-100 nM) on the APD were similar to, but more potent than, those of H2O2. The response was observed rapidly after a light illumination. During exposure to rose bengal (100 nM), abnormal spontaneous action potentials or arrhythmias such as a bigeminy occurred, presumably because of early and delayed afterdepolarizations. The responses were irreversible. At 300 microM ACE inhibitors, captopril and enalapril, protected the changes induced by these free radicals. These results indicate that H2O2 has a dual, time-dependent, action on the APD and rose bengal with light illumination produced the responses rapidly. The oxygen-derived free radicals increased [Ca]i and then cellular Ca2+ overload occurred. These responses were protected by ACE inhibitors.

Action Potentials↗
PubMed1997

Changes of lipoxygenase and fatty acid hydroperoxide lyase activities in bell pepper fruits during maturation.

Developmental changes in fatty acid hydroperoxide lyase (HPO lyase) and lipoxygenase (LOX) during the maturation of bell pepper fruits (Capsicum annuum L. cv. Kyonami) were examined by means of activity measurements, immunological detection of both the enzymes, and analysis of the volatile compounds formed upon homogenization of the fruits. Both the enzyme activities decreased with maturation, and immunological studies showed that the amounts of the enzymes concomitantly decreased. The amounts of six-carbon aldehydes and alcohols formed from bell pepper fruits upon homogenization also decreased during maturation, and with the fully ripened red fruits, these volatile compounds were hardly detectable. These results suggest that the major factor contributing to the changes in the composition of volatile compounds during the maturation of bell pepper fruits was changes in the amounts of HPO lyase and LOX.

Alcohols↗
PubMed1997

[A case of pleural metastasis of invasive thymoma with pulmonary metastasis responding to chemotherapy with cyclophosphamide and prednisolone].

The patient, a 48-year old male, was seen with hoarseness in December 1990. A chest radiograph and chest CT scan showed an anterior mediastinal mass. Median sternotomy revealed epithelial thymoma with involved partial lung and pericardium. After surgery, he received external radiation to the mediastinum. One year later he was given another 40 Gy external radiation in the cervical and mediastinal recurrence region. In May 1994, a chest CT scan revealed an extrapleural and bilateral lung mass. Histological examination revealed recurrent epithelial thymoma in the left cervical muscle biopsy, so treatment with cyclophosphamide and prednisolone were begun. A dose of 100 mg/body/day of cyclophosphamide and a dose of 10 mg/body/day of prednisolone were administered every 2 week. Complete remission was induced with four cycles of this treatment of cyclophosphamide and prednisolone. The chemotherapy was thus continued for 20 cycles in 14 months. This chemotherapy with cyclophosphamide and prednisolone appeared to be useful and safe for recurrent thymoma at the outpatient clinic level.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1997

[Acute retrograde dissection of the aorta is a formidable complication in retrograde perfusion through the femoral artery].

To avoid this complication, we applied a Nelaton catheter (Imamura, Tokyo, Japan: standard type) as a guide to insert an arterial perfusion cannula (Bardic) into the femoral artery. Initially, the Nelaton catheter is accurately placed into the femoral artery through a purse string suture without applying vascular clamps on the artery or its branches. Then the perfusion cannula is advanced using the Nelaton catheter as a guide. We believe this procedure will avoid acute retrograde dissection of the aorta since it protects the femoral artery from injuries caused by the vascular clamps or the tip of the perfusion cannula.

Aortic Dissection↗
PubMed1997

Effects of highly purified eicosapentaenoic acid on vascular reactivity to angiotensin II and norepinephrine in pregnant rabbits.

OBJECTIVE: We sought to determine whether the pressor response to an infusion of angiotensin II during pregnancy would be reduced by the oral administration of highly purified eicosapentaenoic acid ethyl ester (EPA-E). METHODS: We administered EPA-E orally to nine pregnant rabbits (200 mg/kg/day) from day 5 of gestation to day 5 postpartum. Pressor responses to graded doses of intravenously infused angiotensin II and norepinephrine were examined serially during pregnancy and the postpartum period. RESULTS: The EPA-E-treated, as well as the control pregnant rabbits (n = 6), were significantly less responsive to the vasoconstrictor effects of angiotensin II throughout pregnancy than the nonpregnant rabbits (n = 8). The vascular reactivity to infused angiotensin II in EPA-E-treated pregnant rabbits, as compared with that of control pregnant rabbits was unchanged, but reactivity to angiotensin II was lower only on the fifth postpartum day. The pressor responses to infused norepinephrine were unchanged during pregnancy and in the postpartum period, and EPA-E did not alter the response. The litters of four of the nine rabbits were partially or completely macerated. CONCLUSION: EPA-E did not reduce the already blunted pressor responsiveness to angiotensin II during pregnancy in rabbits. The effect of EPA-E in a state of increased pressor responsiveness during pregnancy due to a deficiency of vasodilatory prostaglandins needs to be determined.

Angiotensin II↗
PubMed1997

[Intraoperative and follow-up color Doppler echocardiography for evaluating the surgical results of aortic valvuloplasty in a patient with bicuspid aortic valve].

A 21-year-old man underwent aortic valvuloplasty for aortic regurgitation due to bicuspid aortic valve. After the initial procedure for valvuloplasty of the anterior cusp, transesophageal color Doppler flow imaging revealed a significant regurgitant jet directed posteriorly as observed preoperatively. After an additional valvuloplastic procedure for the anterior cusp, the size of the regurgitant signal was reduced and directed to the center of left ventricular outflow tract. The surgery was then completed. On the 5th postoperative day, an aortic regurgitant murmur reappeared and color Doppler echocardiography showed a mild but significant regurgitant jet directed toward the interventricular septum, which may have been due to contraction of the anterior cusp treated by valvuloplasty. Aggravation of the aortic regurgitation in the early stage after plastic surgery is important and requires consideration in the intraoperative assessment.

Adult↗
PubMed1997

[Thoracoscopic cutting needle biopsy].

We presented a new method of percutaneous cutting needle biopsy under the thoracoscope. Percutaneous cutting needles for lung tumor have been abandoned because the risk of hemorrhage, death, and pneumothorax is much greater with these instruments than the computed tomographic guided needle aspiration. On the other hand, thoracoscopic stapled lung wedge resection is easy to obtain a good sample for any lung disease, but should be needed two or three staples, and waste a time, in the case following lobectomy was needed for malignancy. This thoracoscopic cutting needle biopsy was easy to obtain a specimen for the frozened section diagnosis. Under the view of thoracoscope, percutaneous cutting needle biopsy is safety, saving the cost for staples and easy to control the bleeding from the lung. The indication of this thoracoscopic cutting needle biopsy is the case that could not obtain the precise diagnosis by the preoperative biopsy and imaging diagnosis might be suspicious a malignant tumor.

Biopsy, Needle↗
PubMed1997

Podoplanin, novel 43-kd membrane protein of glomerular epithelial cells, is down-regulated in puromycin nephrosis.

Puromycin aminonucleoside nephrosis (PAN), a rat model of human minimal change nephropathy, is characterized by extensive flattening of glomerular epithelial cell (podocyte) foot processes and by severe proteinuria. For comparison of expression of glomerular membrane proteins of normal and PAN rats, a membrane protein fraction of isolated rat glomeruli was prepared and monoclonal antibodies were raised against it. An IgG-secreting clone designated LF3 was selected that specifically immunolabeled podocytes of normal but not of PAN rats. The antigen of LF3 IgG was identified as a 43-kd glycoprotein. Molecular cloning of its cDNA was performed in a delta gt11 expression library prepared from mRNA of isolated rat glomeruli. The predicted amino acid sequence indicated a 166-amino-acid integral membrane protein with a single membrane-spanning domain, two potential phosphorylation sites in its short cytoplasmic tail, and six potential O-glycosylation sites in the large ectodomain. High amino acid sequence identities were found to membrane glycoproteins of rat lung and bone and mouse thymus epithelial cells as well as to a phorbol-ester-induced protein in a mouse osteoblast cell line and to a canine influenza C virus receptor. In PAN, expression of this 43-kd protein was selectively reduced to < 30%, as determined by quantitative immunogold electron microscopy, immunoblotting, and Northern blotting. These data provide evidence that transcription of the 43-kd transmembrane podocyte glycoprotein is specifically down-regulated in PAN. To indicate that this protein could be associated with transformation of arborized foot processes to flat feet (Latin, pes planus) we have called it podoplanin.

Amino Acid Sequence↗