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Biomedical subjects

K Takeuchi

Publications and source records attributed to K Takeuchi.

At least 847 records · Page 47Linked to original sources
PubMed1991

Antihypertensive effect of captopril and enalapril in endothelin-infused rats.

Comparative effects of angiotensin converting enzyme inhibitors and calcium channel blockers were assessed in rats infused chronically with synthetic endothelin. When 50 mg/kg/day of captopril orally or 6 mg/kg/day of enalapril intraperitoneally was administered simultaneously with 60 micrograms/kg/day of endothelin, the systolic blood pressure was on Day 1 142.7 +/- 5.9 mmHg (p less than 0.05) or 128.7 +/- 6.7 mmHg (p less than 0.05), respectively, compared to the rise to 163.8 +/- 4.7 mmHg when endothelin alone was infused. The antihypertensive effect of captopril or enalapril was sustained for the entire experimental period and was not associated with a significant change in urinary sodium excretion, whereas both drugs induced a significant increase in urine volume. Chronic infusion of angiotensin II intraperitoneally at a subpressor dose (400 micrograms/kg/day) reversed the antihypertensive effect of captopril in endothelin-infused rats. When 6 mg/kg/day of benidipine or 10 mg/kg/day of nilvadipine orally was administered simultaneously with 60 micrograms/kg/day of endothelin, the systolic blood pressure was on Day 1 137.0 +/- 2.4 mmHg (p less than 0.05) or 119.7 +/- 5.9 mmHg (p less than 0.05), respectively, compared to the rise when endothelin alone was infused. The antihypertensive effect of benidipine or nilvadipine was sustained for the entire experimental period and was not associated with any significant changes in urine volume and urinary sodium excretion. These results indicate that the reduced sensitivity of the peripheral arteries to endothelin may be involved in the mechanism of the hypotensive action of angiotensin converting enzyme inhibitors, dependent on the suppressed angiotensin II formation.

Animals↗
PubMed1991

Simultaneous measurements of cytosolic free calcium level and prostaglandin synthesis reveal a correlation between them in perfused monolayer of cultured rat vascular smooth muscle cells: effects of bradykinin and angiotensin II.

The level of cytosolic free calcium ([Ca2+]i) and the production rate of prostacyclin were simultaneously measured in perfused monolayers of cultured vascular smooth muscle (VSM) cells. After loading of fura-2 (a fluorescent calcium indicator), the monolayer of VSM cells (cultured on a cover glass) was fixed in the perfusion cuvette and the cuvette was placed in a fluorometer to monitor the change in [Ca2+]i. The monolayer was perfused and the fractionated perfusion solution was collected to determine 6-keto-PGF1 alpha (a metabolite of prostacyclin) production found in the solution. Afterwards, the time-dependent changes in [Ca2+]i and 6-keto-PGF1 alpha synthesis were compared. Bradykinin (BK, 10(-6) M), angiotensin (Ang) II (10(-7) M) as well as ionomycin (10(-6) M) induced simultaneous increases in [Ca2+]i and 6-keto-PGF1 alpha production. An inhibitor against prostaglandin synthesis, acetylsalicylic acid (ASA, 10(-6) M) abolished BK-induced 6-keto-PGF1 alpha synthesis, whereas ASA did not affect the increase in [Ca2+]i. BK-induced increases in [Ca2+]i and 6-keto-PGF1 alpha production occurred in a dose-dependent manner and the half-maximal response was observed at the same concentration of BK (10(-7) M). These results indicate that an increase in [Ca2+]i is closely associated with BK as well as AngII-induced prostacyclin synthesis. It is suggested that an increase in [Ca2+]i plays a prior role in prostacyclin synthesis. Thus, an interaction between phospholipase A2 (prostaglandin synthesis) and phospholipase C (inositol trisphosphate-Ca2+ mobilization) is suggested.

Angiotensin II↗
PubMed1991

No adverse effect of non-steroidal anti-inflammatory drugs, sulindac and diclofenac sodium, on blood pressure control with a calcium antagonist, nifedipine, in elderly hypertensive patients.

Effect of non-steroidal anti-inflammatory drug (NSAID) on blood pressure (BP) control was evaluated in elderly hypertensive patients treated with calcium antagonist. The study was based on a randomized, crossover design to compare the effect of an NSAID, sulindac, with that of another NSAID, diclofenac sodium, in the hypertension treatment. The study was completed in six elderly female subjects (the average age: 66 +/- 3 year) whose systolic BP and diastolic BP were more than 160 mmHg and more than 95 mmHg, respectively. When BP was controlled by nifedipine (20 mg x 2 per day in slow releasing form) within normal limits, sulindac (100 mg x 3 per day) or diclofenac sodium (25 mg x 3 per day) was administered for a week. After one week-washout period, the other NSAID was substituted. Plasma and urinary variables were measured on the final day of each study period. The average systolic BP and diastolic BP and the entry of study were 167 +/- 5 mmHg and 93 +/- 5 mmHg, respectively. Nifedipine significantly decreased the systolic BP to 140 +/- 4 mmHg (p less than 0.02) and the diastolic BP to 84 +/- 4 mmHg (p less than 0.05). Addition of either sulindac or diclofenac sodium did not affect BP, whereas urinary PGE2 excretion and plasma renin activity were significantly inhibited. Plasma creatinine and electrolyte concentration were not changed by the NSAIDs. The results indicate that either sulindac or diclofenac sodium does not interfere with control of hypertension by a calcium antagonist, nifedipine in in elderly hypertensive patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1991

[Clinico-histological study of low-density non-enhancing glioma].

Some gliomas are not noticeably enhanced on initial computer tomography (CT) scans. Such low-density non-enhancing gliomas have a relatively long period between onset and surgery ranging from 5 to 25 months. The mechanism causing the low density over a certain period of time in the sequential CT findings was retrospectively investigated. Characteristic histological findings associated with such low-density areas were microcystic formation, necrosis, intratumoral edema, infiltrative growth, and absence of capillary proliferation. Proliferation of capillary vessels is characteristic of CT enhancement.

Adolescent↗
PubMed1991

Role of transepithelial ion transport as a determinant of mucus viscoelasticity in chronic inflammation of the maxillary sinus.

Chronic sinusitis is a chronic inflammatory disease with fluid retention, most frequently in maxillary sinus. We measured both viscoelasticity of maxillary sinus fluid and bioelectric properties of maxillary mucosa in an attempt to correlate the mucus viscoelasticity with bioelectric properties. During sinus surgery, maxillary sinus fluid and maxillary mucosa were obtained from 15 patients with chronic sinusitis. Viscoelasticity was measured with an oscillating sphere magnetic rheometer within 24 h after sampling. Potential difference and short circuit current of maxillary mucosa mounted in Ussing chambers were measured before and after exposure of mucosal surface to amiloride. Both elasticity and viscosity showed significant positive correlation with percent inhibition of short-circuit current by amiloride. Our results indicate that the ion transport process plays a role in the determination of viscoelasticity of maxillary sinus fluid in chronic sinusitis.

Adult↗
PubMed1991

A quantitative study of the ciliary area of experimental otitis media with effusion in cats.

A quantitative electron microscopic study was performed to determine the extent of the ciliary surface area of the middle ear epithelium in cats. In normal cats, 97.8% of the middle ear mucosa in the hypotympanum and 45.9% in the upper part of the bulla were covered by cilia. Eustachian tube obstruction (ETO) significantly reduced the ciliary area to 73.1% in the hypotympanum and to 16.2% in the upper part of bulla at 1 week after ETO. Instillation of Escherichia coli lipopolysaccharide (LPS) or cat polymorphonuclear leukocyte (PMN) lysate into the middle ear cavity followed by ETO did not reduce the ciliary area, compared with ETO induced alone. Our results indicate that ETO reduces the ciliary area of the middle ear mucosa and that LPS or neutrophils do not enhance reduction of the ciliary area compared to ETO induced alone in this experimental condition.

Animals↗
PubMed1991

Rheological properties of middle ear mucus in relation to goblet cell population in cat.

Seventeen mucoid middle ear effusions were collected from the tympanic cavity of 15 cats 1 or 2 weeks after tubal obstruction. Middle ear mucosa was also taken both from the tympanic cavity and bulla, and the number of goblet cells was counted. Both elasticity (G') viscosity (eta') of the mucoid effusion were determined with an oscillating sphere magnetic rheometer and compared with goblet cell count. There was a significant correlation between G' and goblet cell population in the tympanic cavity. A similar significant correlation was observed between eta' and goblet cells. The G' and eta' values of the mucoid mucus were much higher than the optimal viscoelasticity for mucociliary transport. Results indicate that the mucus obtained in this study mainly originated from the goblet cells, and that its viscoelasticity was beyond ideal values for mucociliary transport.

Animals↗
PubMed1991

Rheological and biochemical properties of middle ear effusions from experimental otitis media in cats.

Both rheological and biochemical analyses were performed on middle ear effusions (MEEs) from cats with experimental otitis media with effusions (OME) induced by obstruction of the Eustachian tube. This study was undertaken in order to clarify the factors determining rheological properties (elasticity and viscosity) of MEEs. The viscoelasticity of the effusions had a positive significant correlation to fucose/total protein concentration (TPC), and a negative correlation to cathepsin B level/TPC. No correlation was observed between albumin level/TPC and viscoelasticity. These results indicate that in cats the rheological properties of MEEs depend on the level of secretory glycoproteins in MEEs and on the severity of inflammation in the early stage after tubal obstruction.

Albumins↗
PubMed1991

The relationship between proteases activity and glycoprotein levels in middle ear effusions from experimental otitis media in cats.

The relationship between lysosomal proteases activity (elastase and cathepsin B) and levels of mucous glycoproteins in middle ear effusions (MEEs) was studied using a cat model of otitis media with effusion (OME) induced by Eustachian tube obstruction (ETO). The ratio of cathepsin B activity to total protein concentration (TPC) in MEE was 25.6 +/- 19.4 RFU/g x dl-1 at 1 week after ETO, and increased with the duration of OME. The ratio of elastase activity to TPC had a significant correlation to total leukocyte count. The ratio of fucose levels to TPC, which is one of the parameters reflecting levels of mucous glycoprotein, at 1 week after ETO was significantly higher than that at both 2 and 4 weeks after ETO. The percentage of glycoprotein levels absorbed to wheat germ lectin was highest at 1 week after ETO, and decreased with the duration of OME. In conclusion, mucous glycoproteins in cat occupy a larger portion of glycoproteins in MEE at the early stage of OME, and elastase and other lysosomal proteases may play a role in both stimulation of mucin release from goblet cells and mucin degradation. The balance of these processes seems to be a key factor determining mucin levels in MEEs.

Albumins↗
PubMed1991

Effects of endotoxin and neutrophil lysate on experimental otitis media with effusion in cats.

Middle ear effusion (MEE) from otitis media with effusion (OME) contains large amounts of chemical mediators and substances from bacteria, which may act on the mucosa itself and cause further changes in the inflamed mucosa and MEE. To clarify the effects of such substances in MEE, we instilled endotoxin (LPS) or allogeneic neutrophil lysate (NL) into the middle ear cavity of OME induced by Eustachian tube obstruction (ETO). ETO + LPS and ETO + NL groups showed retention of a large amount of MEE as a characteristic difference between ETO alone group and these groups. The instillation of LPS into the middle ear cavity of the ETO model significantly increased the number of total cells and the ratio of the concentrations of albumin to total protein in MEEs. The instillation of NL significantly increased the number of goblet cells in the middle ear. These facts indicate that the pathology of OME may change in response to various factors added to MEE. Hence, we propose that a vicious circle of self-mediated inflammation is a possible causative factor for chronic OME.

Animals↗
PubMed1991

Quantitative histochemical study of secretory cells after short term tubal obstruction in the cat.

Quantitative histochemistry of goblet cells producing different types of glycoproteins was examined in cat middle ears with and without Euatachian tube obstruction (ETO). The goblet cell population significantly increased at 1 week after ETO and showed a tendency to decrease down to the normal level at 4 weeks after ETO. In the normal ears, approximately 85% of glycoprotein in the secretory cells were sulphated and 15% were neutral. ETO significantly increased goblet cell population containing sulphated glycoprotein at the expense of neutral glycoprotein. The results indicate that goblet cells can easily and within a short period be modified both in number and in intracellular glycoproteins by a tubal obstruction.

Animals↗
PubMed1991

[Computer-aided visuospatial cognitive-performance test].

The validity of a newly developed computer-aided "Visuospatial Cognitive-Performance Test" (VCP-Test) was examined in two populations, 68 normal elderly volunteers (mean age, 69.5% years) and 25 patients with dementia (mean age, 68.2 years). None of the cases in the two groups had either motor impairment or ataxia. The VCP-Test was a kind of vigilance task in which a subject is required to tap the key corresponding to the local change-over of the image on the computer display as quickly as possible. After 40 trials, consecutive data of performance efficiency were automatically displayed on the LCD display and printed out. A significant negative correlation between the VCP-Test and age in normal elderly population was recognized. Moreover, the relationship between the VCP-Test and the Hasegawa Dementia Scale (HDS), and the Mini-Mental State (MMS) was also significant in patients with dementia. In conclusion, the VCP-Test was considered to be useful for geriatric neurobehavioral functional assessment and for the detection of dementia.

Aged↗
PubMed1991

Properties of a cell line (MEG-01SSF) of human megakaryoblastic leukemia cells.

MEG-01SSF cells were prepared from MEG-01S by conditioning in a chemically defined, serum-free medium. The cells grew well in the medium and required transferrin for growth. Doubling time was about 20 hours. The cells retained GpIIb/IIIa as a marker of megakaryocytes and transferrin receptors on the cell surface. Some of the cells in the stationary phase of growth produced platelet-like particles, which bore characteristic microtubule rings.

Antigens, Surface↗
PubMed1991

Purification and properties of a novel surface-active agent- and alkaline-resistant protease from Bacillus sp. Y.

In the course of a search for an alkaline stable protease for industrial use, an alkaline protease (protease BYA) was isolated from an alkalophilic Bacillus sp. Y, and its properties were characterized. Its optimum pH was pH 10.0-12.5, when casein was used as a substrate. In addition to the stability of protease BYA at pH 6.5-13.0, it was also very stable towards various surface-active agents, such as sodium dodecyl sulfate and sodium linear alkylbenzene sulfonate. Protease BYA was most active at 70 degrees C. The isoelectric point (pI) of protease BYA was about 10.1. Protease BYA was characterized as a serine protease because of its sensitivity to phenylmethanesulfonyl fluoride and diisopropyl fluorophosphate. The protease seems to be related to proteases of the subtilisin family, such as subtilisin BPN', subtilisin Carlsberg, and No. 221 protease.

Amino Acid Sequence↗
PubMed1991

[Etiology of left ventricular rupture following mitral valve replacement].

Two uncommon cases of left ventricular rupture that occurred during cardiac surgery were treated successfully. These cases may be useful in understanding the etiology of common left ventricular rupture following mitral valve replacement. One case occurred during coronary bypass surgery. The myocardium which is already abnormal seems to be weak to trauma such as bending, traction and torsion. In the other case, who underwent mitral valve replacement with preservation of the posterior leaflet with its attached chordae, the disruption was localized in the epicardial side of the left ventricular posterior wall, though direct injury by some instrument was excluded as a possibility, with a depth of half the thickness of the wall. In experiments using dogs, shape and movement of the mitral annulus were examined. The length of the annulus attached to the posterior leaflet in end-systole was shortened to 89.0 +/- 4.6% of that in late diastole. Furthermore, the annulus was distorted by the elevation of the heart. We approve of Cobbs' "untethered ventricle theory" and consider moreover as follows: In general, whether with or without preservation of the mitral loop, the mitral annulus and the left ventricular posterior wall after mitral valve replacement are severely constricted by the rigid prosthetic ring and become tense, which limits movement in both circular and longitudinal directions. Then even slight stress may cause a primary tear on the posterior wall of the left ventricle, resulting in rupture. In order to treat the rift, the prosthesis must be removed before the apex of the heart is lifted, to avoid excessive ventricular wall tension.

Aged↗
PubMed1991

[Difference of blood cell counts with reference blood cell counters in three different makers].

To determine the difference of CBC values in different blood cell counters, we have measured the values of CBC by using reference cell counters of three major makers; Coulter, Sysmex and Technicon. Thirty ml of whole blood was taken from 2 healthy individuals and mixed with 45 mg of EDTA -2K. The blood samples were then sent to reference laboratory of each maker under identical conditions. The determination of cell counts was performed 4 hours after taking blood. Ten consecutive analysis were then carried out and the mean of 10 values was calculated. The apparent difference was displayed in leucocyte and platelet counts. In both of two samples, the highest values of either leucocyte or platelet count was obtained with Coulter instrument. And second high values were noted with Sysmex counter and the lowest values were observed by Technicon instrument. The extent of difference between each instrument was over 10% in case of platelet count and was 5 to 10% in leucocyte count. The difference of erythrocyte count, Hgb level, hematocrit value and MCV also existed, but the extent of difference was within 5% in all of these examinations. Since CV of each examination was sufficiently low level, this difference might be due to the difference in accuracy of reference cell counter of each maker. These results suggest that distinct differences of CBC count, particularly platelet and leucocyte count can be produced by the different procedures of calibration for reference counter in each maker of automated blood cell counter.

Adult↗
PubMed1991

[A case of disproportionately large communicating fourth ventricle after resection of temporal astrocytoma that evolved an isolated fourth ventricle].

The isolation and enlargement of the fourth ventricle after a ventriculoperitoneal (V-P) shunt was classified as "isolated fourth ventricle (IFV)". The term, "disproportionately large communicating fourth ventricle (DFV)" was first introduced by Scotti et al as being an enlarged fourth ventricle communicating with the third ventricle. The authors present a case of DFV after the resection of an astrocytoma. Upon recurrence of the tumor a second resection was carried out 5 years later. It was found that IFV had evolved because a cyst in the right temporal lobe was obstructing the aqueduct. After shunting of the tumor cyst, the aqueduct was again found to be patent and the fourth ventricle gradually decreased in size. A 34-year-old female presented headache, nausea, and a mild left hemiparesis. An initial CT scan demonstrated a fourth ventricle of approximately normal size and a right temporal mass. The first craniotomy revealed an astrocytoma. A CT scan after the surgical procedure showed enlargement of all ventricles, especially the fourth, resulting from the blockage of the foramina of Luschka and Magendie. The insertion of a V-P shunt was followed by a reduction in size of all ventricles. The diagnosis of DFV was thus confirmed because the fourth ventricle had a demonstrated communication with the third ventricle. After a second craniotomy for tumor recurrence five years later, a CT scan revealed the enlargement of the fourth ventricle and a cyst in the right temporal lobe. A metrizamide CT scan revealed that the cyst was isolated and an RI ventriculogram confirmed obstruction of the aqueduct.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗