Search PubMed⌕ Search

Biomedical subjects

K Matsui

Publications and source records attributed to K Matsui.

At least 433 records · Page 24Linked to original sources
PubMed1990

Chemical modification by 2,4,6-trinitrobenzenesulfonic acid (TNBS) of an essential amino group in 3-ketovalidoxylamine A C-N lyase.

3-Ketovalidoxylamine A C-N lyase of Flavobacterium saccharophilum is a monomeric protein with a molecular weight of 36000, and contains 32 amino groups and no cysteine or cystine residues. The enzyme was inactivated by 2,4,6-trinitrobenzenesulfonic acid (TNBS) following pseudo-first order kinetics. Substrate of the lyase, p-nitrophenyl-3-ketovalidamine, protected the enzyme against the inactivation, suggesting that the modification occurred at or near the active site. Although several amino groups were modified by TNBS, a plot of log (reciprocal of the half-time of inactivation) versus log (concentration of TNBS) suggested that one amino group has an essential role in catalysis.

Amino Acids↗
PubMed1990

Inhibitory effect of validamine, valienamine and valiolamine on activities of carbohydrases in rat small intestinal brush border membranes.

Three pseudo-aminosugars, validamine, valienamine and valiolamine, produced by Streptomyces hygroscopicus subsp. limoneus showed potent inhibitory action on rat small intestinal carbohydrase activities such as sucrase, maltase, glucoamylase, isomaltase and trehalase activities, but negligible action on lactase activity and pancreatic alpha-amylase activity. Where inhibition was seen, kinetic analysis showed fully competitive inhibition of the carbohydrase activities by all three inhibitors. Valiolamine has more potent carbohydrase inhibitory activity than validamine or valienamine, and the apparent Ki values of valiolamine for sucrase, maltase, glucoamylase, isomaltase and trehalase activities were 3.2 x 10(-7), 2.9 x 10(-6), 1.2 x 10(-6), 9.1 x 10(-7) and 4.9 x 10(-5) M, respectively, which are 10(-5) to 10(-3) times smaller than the apparent Km values.

Animals↗
PubMed1990

Synthesis, chemical properties and mutagenicity of 1,6- and 3,6-dinitrobenzo[a]pyrenes.

Nitration of benzo[a]pyrene (BaP) with HNO3 (d = 1.38) produced a mixture of dinitroBaPs (1,6- and 3,6-isomers) and mononitroBaPs (1-, 3- and 6-isomers). Pure 1,6-dinitroBaP and 3,6-dinitroBaP were obtained by the reduction of the dinitroBaPs mixture with NaSH to yield the separable products 1-amino-6-nitroBaP and 3-amino-6-nitroBaP, followed by conversion to dinitroBaPs via the the diazonium salts. The half-wave potentials (E1/2) corresponding to the one-electron reduction of dinitroBaPs were measured and the relationship of these values to the mutagenicity is discussed.

Benzopyrenes↗
PubMed1990

Effect of multiple-dose irradiation on repair capacity in plateau phase C3H 10T1/2 cells.

Using plateau phase C3H 10T1/2 cells, we studied the effect of multiple-dose irradiation on the repair capacity of cells after further irradiation. Cells were irradiated with repeated doses of 2.5 Gy delivered two fractions per day at 6 to 7 hours interval. The cell survival after exposure to 1 to 9 fractions was lower above 5 fractions as compared to that predicted by calculating from single dose survival curve by assuming that cells retain their capacity to repair radiation damage after each fraction. Repair kinetics experiments showed that cells were less able to repair potentially lethal damage after test dose following multiple dose irradiations. There was, however, no difference in the ability to repair sublethal damage and potentially lethal damage sensitive to anisotonic treatment in preirradiated and untreated cells. Thus, it would appear that an enhancement of the lethal expression of potentially lethal damage of three types of damage may, at least in part, contribute to the difference between the cell survival curve after multiple fractions and that predicted by calculation.

Animals↗
PubMed1990

Effects of central osmotic stimulation on vasopressin and enkephalin release into the blood and cerebrospinal fluid and blood pressure.

To assess the central effect of hypertonic NaCl on the release of vasopressin (AVP) and methionine enkephalin-like substances into the blood and cerebrospinal fluid, and on blood pressure, ventriculocisternal perfusion (0.25 ml/min, 60 min) was performed in anesthetized dogs with artificial cerebrospinal fluid (CSF), either isotonic (300 mosmol/kg) or hypertonic (600 and 1200 mosmol/kg). The effect of central administration of a V1-AVP antagonist on the central osmotic challenge was also studied. In dogs, given 600 mosmol/kg, CSF osmolality increased with a concomitant rise in mean arterial pressure and plasma AVP concentrations. Plasma osmolality, heart rate, CSF AVP and plasma and CSF methionine enkephalin-like substances showed no significant change. In dogs, given 1200 mosmol/kg, the CSF osmolality increase was accompanied by a rise in mean arterial pressure, heart rate, plasma AVP and CSF AVP. Plasma osmolality and plasma and CSF methionine-enkephalin-like substances did not change significantly. A V1-AVP antagonist given centrally attenuated the rise in mean arterial pressure induced by osmotic challenge. In dogs, given 300 mosmol/kg, no parameters changed significantly except for a gradual fall in heart rate. These results suggest that central osmotic stimulation by hypertonic NaCl increases blood pressure, heart rate and the release of AVP, but not methionine enkephalin-like substances, into the blood and CSF, and a V1-blocker given centrally attenuates the pressor response.

Animals↗
PubMed1990

[Diurnal rhythms of body temperature, heart rate, and behaviour in the stanchioned adult Shiba goats].

Using a data logger system, body temperature (dorsal subcutaneous temperature), heart rate, ingestive or ruminating behaviour and posture in adult Shiba goats tied to a stanchion were recorded automatically during 24 hours, to obtain basic information on the biological rhythms. A 600 g of usual ration mixed with hay cube, hay, beet pulp and wheat bran was fed twice a day (morning; 9:00-9:30, evening; 16:00-16:30). Animals kept under an artificial photoperiod (12L-12D, light period; 5:30-17:30) and about 10 degrees C room temperature. 1) Diurnal patterns of the above-mentioned items were recorded, mutual relationships relationships between these items were revealed. 2) The heart rate was higher after morning feeding, or during a light period and decreased gradually from midnight to early morning. Twice feeding greatly increased the heart rate. 3) The body temperature was lower in the early morning and increased gradually after morning feeding and showed the highest level during 1 to 1.5 hours after evening feeding. After that it decreased gradually till the early morning. 4) The numbers of jaw movement (bites/min) were a 70-90 bites in the ingestive behaviour and a 80-90 bites in the ruminating behaviour at dark period. 5) The total heart rate was a 110000 to 120000 beats/day, the total biting time was a 9.5 hours/day, and the mean standing time was a 9.3 to 11.7 hours/day. The standing time during light period (12 hours) was a 7.3 to 9.9 hours and that during dark period (12 hours) was a 1.8 to 2 hours.

Animals↗
PubMed1990

Combination therapy with bestatin in inoperable lung cancer. A randomized trial.

A randomized trial of combination therapy with bestatin (30 mg daily, every day) was performed in 238 patients with inoperable primary lung cancer from August, 1981 through April, 1984. Of the 238 patients, 227 were evaluable: 113 treated by bestatin combination therapy and 114 controls. There was no statistically significant difference in response rate or survival between the 2 groups. In squamous cell cancer response was observed in 34.5% of the bestatin group and 17.9% of the control group. The analysis, including Cox's proportional hazard model, revealed that the survival tended to be longer in the bestatin group (median survival 40 weeks) than in the control group (median survival 24 weeks; p = 0.051). This suggests that addition of bestatin might be beneficial in squamous cell cancer of the lung but further, more rigidly controlled, clinical trials are necessary before more definitive conclusions can be drawn.

Aged↗
PubMed1990

Trehalase inhibitors, validoxylamine A and related compounds as insecticides.

Validoxylamine A showed a potent inhibitory activity against insect trehalase in a competitive manner with a Ki value of 4.3 x 10(-10) M. The other validoxylamines and validamycins also exhibited the activity in vitro. Injection of these compounds to young last instar larvae of the tobacco cutworm, Spodoptera litura, elicited the morphological abnormality followed by death after the cessation of feeding. Validoxylamine A showed 100% mortality at a dose of 10 micrograms/ last instar larva.

Animals↗
PubMed1990

Cloning and characterization of genes responsible for m-fluoro-D,L-phenylalanine resistance in Brevibacterium lactofermentum.

Two kinds of 3-deoxy-D-arabino-hepturosonate-7-phosphate (DAHP) synthase genes were cloned from an L-Phe-producing mutant of Brevibacterium lactofermentum, AJ11957, which was resistant to m-fluoro-D,L-phenylalanine (mFP) and p-fluoro-D,L-phenylalanine (pFP) and which had DAHP synthase free from feedback inhibition. Both genes were cloned using a vector plasmid, pAJ1844, and the resulting recombinant plasmids were named pAR1 and pAR2. They had different structures on the restriction maps. Both plasmids, pAR1 and pAR2, conferred mFP and pFP resistance and L-Phe and L-Tyr productivity on a wild-type strain of B. lactofermentum, AJ12036. The degrees of L-Phe-analogue resistance and aromatic amino acid productivity of the pAR1-transformant were larger than those of the pAR2-transformant. The introduction of pAR1 to AJ12036 resulted in the alteration of DAHP synthase activity from a feedback-sensitive mechanism to a feedback-insensitive one accompanied by an elevated level of specific activity. A DAHP synthase deficient mutant of Escherichia coli was complemented by pAR2, but not by pAR1. Characteristics of the two kinds of DAHP synthase genes are discussed.

3-Deoxy-7-Phosphoheptulonate Synthase↗
PubMed1990

[Hemodynamic features of hypotension induced by nicardipine in dogs].

Hemodynamic features of hypotension induced by nicardipine were studied in 18 mongrel dogs under 0.87% halothane in oxygen (1MAC). They were randomly allocated to one of two groups. Group C received no vasodilator therapy and served as control and group N received infusion of nicardipine. Mean arterial pressure decreased and was maintained at 60 mmHg for 60 minutes in group N. No change was noted in hemodynamic variables measured in group C throughout the experiment. During and after induced hypotension in group N, cardiac index (CI), stroke volume index (SVI), central venous pressure (CVP), and right ventricular stroke work index (RVSWI) increased significantly compared with the control values. On the other hand, systemic vascular resistance (SVR) was significantly reduced, reaching 25% of the control value at the end of hypotension period. Heart rate showed a progressive increase but not significantly. Left ventricular maximum dp/dt showed a moderate increase during hypotension, but then decreased gradually to the control value after induced hypotension. Left ventricular stroke work index (LVSWI) and pulmonary vascular resistant (PVR) were unchanged from the control value during and after induced hypotension. The data indicate that nicardipine is a potent systemic vasodilator with hyperdynamic hemodynamic effects in addition to significant increase in right ventricular function.

Animals↗
PubMed1990

[Prognostic factors affecting survival and response in patients with advanced non-small cell lung cancer treated with combination chemotherapy].

One-hundred and ninety-nine patients who had an inoperable stage III or IV non-small cell lung cancer (NSCLC) and collected were analyzed on the basis of factors affecting survival duration and response to chemotherapy. These patients were registered into a prospective randomized trial conducted from May of 1986 to April of 1988, and received either cisplatin and vindesine, cisplatin, vindesine and mitomycin C, or cisplatin and etoposide alternating with vindesine and mitomycin C. In the univariate analysis, sex, ECOG's performance status (PS), weight loss within previous 6 months, clinical stage, serum albumin value, serum lactate dehydrogenase level and hemoglobin (Hb) level were considered to be significant factors for survival (p less than 0.05). In the multivariable analysis using Cox's proportional model, clinical stage, PS, sex, weight loss and Hb level were proven to be significant variables for survival in the order of importance. When the response to chemotherapy was included in a conditional multivariable analysis, it was strongly associated with survival duration. A multivariable analysis of response using the logistic regression method demonstrated that female sex, cisplatin, vindesine and mitomycin combination regimen, squamous cell type, and no weight loss were significantly predictive of response outcome. These results are useful when comparing the response data and survival of completed studies and designing future trials in advanced NSCLC.

Adult↗
PubMed1990

[Current results of chemotherapy in non-small cell lung cancer].

From 1983 to 1988, two prospective randomized studies were conducted in the treatment of patients with inoperable non-small cell lung cancer (NSCLC). The first was a comparison of cisplatin (CDDP) alone vs CDDP plus vindesine (VDS) (CV-1), and the second was the comparison of CDDP plus VDS (CV-2) vs CDDP plus VDS plus mitomycin (MMC) (CVM) vs CDDP plus etoposide alternating with VDS plus MMC (CE/VM). A total of 345 patients entered into these two studies were evaluated. The response rates were 9.3% for CDDP alone, 26.8% for CV-1, 33.3% for CV-2, 42.6% for CVM, and 19.1% for CE/VE. There were significant differences in response rates between CDDP alone and CV-1 (p less than 0.01), and CVM and CE/VM (p less than 0.01). No differences were observed in the durations of response and survival among the five treatment arms. Females responded to chemotherapy better than males, and squamous cell carcinoma responded better than adenocarcinoma. Sex, performance status and stage were significant as prognostic factors in advanced NSCLC patients. Responders to chemotherapy live longer than nonresponders. In conclusion, CVM is considered to be currently best available regimen. No survival benefit has been proved for any treatments for advanced NSCLC. Chemotherapy for NSCLC is still investigational.

Adult↗
PubMed1990

[Endocrine effects of hypotension induced by nicardipine in rabbits].

Endocrine effects of hypotension induced by nicardipine, a calcium antagonist, were studied in 18 male rabbits under halothane anesthesia. They were randomly divided into two groups; nicardipine (group N; n = 10) and controls (group C; n = 8). No change was noted in plasma catecholamines in group C throughout the experiment, but plasma renin activity decreased progressively. During and after induced hypotension, in group N, plasma epinephrine was significantly higher than the control value. The highest level of plasma epinephrine was seven times of the control value during 30 minutes after induction of hypotension. Plasma norepinephrine of group N was significantly higher than the controls. The maximum increase occurred 60 minutes after induction of hypotension. Plasma renin activity of group N was significantly higher than the control value. Compared with the control value (15.1 +/- 1.8 ng.ml-1.hr-1), plasma renin activity was activated 30 and 60 minutes after induction of hypotension (55.5 +/- 6.0 ng.ml-1.hr-1, P less than 0.001, 50.3 +/- 7.1 ng.ml-1.hr-1, P less than 0.01, respectively). In conclusion, our data show that hypotension by nicardipine activates the renin-angiotensin-sympathetic system.

Animals↗
PubMed1990

[A carcinosarcoma of the ovary: a case report and a review].

A carcinosarcoma of the ovary, which is a combined epithelial and mesenchymal tumor, is exceeding rare and usually has poor prognosis. Only four known cases, including this case, have been reported in Japan. In our case, after resection a combined chemotherapy consisting of cisplatinum, adriamycin cyclophosphamide and etoposide was administered and the patient had no uneventful postsurgical course.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1990

ABO blood-typing of bloodstains by dot-ELISA method.

The ABH antigens of bloodstains which were effectively solubilized in phosphate-buffered saline by crushing in a mortar were detected on a nitrocellulose membrane by enzyme-linked immunosorbent assay (ELISA). The analyses for characterization showed that the extracted substances consisted of various components of the red cell with molecular weights of more than 30,000. ABO types of some aged bloodstains were determined by this simple procedure. This method is a useful tool for determining various blood-groups from bloodstain.

ABO Blood-Group System↗
PubMed1990

[A case of primary leiomyosarcoma of the lung].

We reported a case of 66-year-old female with leiomyosarcoma of the right lower lobe of the lung with the complaint of abnormal shadow of the chest roentgenogram. On December 2, 1987, partial resection was performed and the tumor was totally removed. Histological examination revealed primary leiomyosarcoma of the lung. By electron microscopic observation, pinocytotic vesicle was not observed, but myofilaments were observed in the cytoplasm.

Aged↗
PubMed1990

[Rupture of an infected vein graft in the course of mediastinitis following coronary artery bypass grafting: report of a case].

A 51-year-old man developed a Staphylococcal mediastinitis and septicemia 23 days after coronary artery bypass grafting. He was initially treated with surgical debridement and closed irrigation with 0.5% povidone iodine solution. However, since the infection could not be eradicated by this method, an open packing method was subsequently required. Nineteen days after the diagnosis of mediastinitis, massive bleeding occurred due to rupture of an infected vein graft to the LAD. Although he went into profound hemorrhagic shock, suture ligation of the vein graft was successfully performed. The sternum was reapproximated 34 days after the initial debridement. Postoperative coronary angiograms revealed the patent vein grafts to the RCA and LCX, and PTCA was performed to the native stenosis of the LAD. The patient was discharged 5 months after the bypass operation and is now doing well 3 years postoperatively. Rupture of the heart or vessels in the course of postoperative mediastinitis is a very rare but highly lethal complication. We think that it is important to eradicate the infection as soon as possible to prevent the bleeding complication and that the decision as to which method, closed or open, should be employed, is crucial.

Blood Vessel Prosthesis↗