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Biomedical subjects

K Otsuka

Publications and source records attributed to K Otsuka.

At least 253 records · Page 14Linked to original sources
PubMed1991

Enzymatic regulation of glycolysis and gluconeogenesis in rabbit periodontal ligament under various physiological pH conditions.

Optimal concentrations of the essential components for analyzing the activity of each enzyme associated with glycolysis and gluconeogenesis in rabbit periodontal ligament were examined, and enzyme assay systems for 15 enzymes including 22 reactions were established using triethanolamine buffer. Specific activities of all the enzymes, except for the gluconeogenic reaction of phosphoglycerate kinase, were systematically evaluated using the optimum buffer for each enzyme, since the activity of each enzyme varied depending on the buffer used. For glycolysis, the activity levels of hexokinase and 6-phosphofructokinase were very low, and consequently these enzyme reactions were inferred to be the rate-limiting steps. For gluconeogenesis, fructose 1,6-bisphosphatase and aldolase activities were extremely low, and the activities of glucose 6-phosphatase, phosphoenolpyruvate carboxykinase and pyruvate carboxylase were undetectable. These results suggest that the periodontal ligament may have no gluconeogenesis capability. With a rise in pH, the activities of the key enzymes of glycolysis gradually increased, and a specific "crossover" point was found between the activities of glyceraldehyde-phosphate dehydrogenase and phosphoglyceromutase. In addition, the activity of fructose 1,6-bisphosphatase, one of the key enzymes of gluconeogenesis, was markedly increased with a rise in pH, although pH changes had no effect on aldolase activity. Consequently, alkaline pH appeared to result in overall stimulation of glycolysis.

Animals↗
PubMed1991

Blood group N antigen precursor glycoproteins and N antigen precursor glycoproteins with Thomsen-Friedenreich (T) activity from human liver metastatic carcinomas.

1. Four perchloric acid-soluble fractions (PASFs) from human liver metastases of sigmoid colon carcinoma (LSCC), pancreas carcinoma (LPC), breast carcinoma (LBC) and human normal liver (NL) were subjected to DEAE-cellulose column chromatography and separated into three glycoprotein fractions, respectively. 2. In chromatography, LSCC-PASF and LBC-PASF gave Thomsen-Friedenreich (T)-active glycoprotein, blood group N antigen precursor glycoprotein with T activity and N antigen precursor glycoprotein, respectively. 3. LPC-PASF gave N antigen precursor glycoprotein with T activity and two N antigen precursor glycoproteins. 4. The three glycoprotein fractions from NL-PASF did not exhibit both T activity and N antigen precursor activity.

Antigens, Neoplasm↗
PubMed1991

Embryonic expression of beta-actin-lacZ hybrid gene injected into the fertilized ovum of the domestic fowl.

An experiment was carried out to investigate the expression of cloned DNA injected into the germinal disc of the chick fertilized ovum. The beta-actin-lacZ hybrid gene, MiwZ, was injected, in the closed circular form, into the cytoplasm of the germinal disc at the single-cell stage. The embryos were cultured in vitro, then in recipient eggshells up to day 4 of incubation. The survival rate of the embryos at day 4 was 42% (55/130), and the rate of embryos expressing MiwZ was 64% (35/55). Twenty-two embryos expressed the MiwZ in both embryonic and extraembryonic tissues, while the remainder expressed the MiwZ in only extraembryonic tissues. Mosaic expression was observed in most of the embryos expressing MiwZ in embryonic tissues. Expression throughout all tissues of the embryo including blood cells occurred in one case. In this case, the injected DNA was assumed to have integrated at an earlier stage. The results indicate that it is now possible to investigate the promoter activities of introduced exogenous genes as well as the effect of introduced genes on embryogenesis in early chick embryos. This technique may also facilitate the production of transgenic chicks.

Actins↗
PubMed1991

[Upper airway finding on CT scan with and without nasal CPAP in obstructive sleep apnea patients].

The area of upper airway (from the nasopharynx to the hypopharynx) was measured by means of computed tomography (CT) scan in 15 confirmed cases of obstructive sleep apnea (OSA) and in 4 normal controls while they were awake. The minimum cross-sectional area (MA) of the upper airway was 14.7 +/- 20.0 mm2 in OSA patients and 80.0 +/- 33.1 mm2 in normal controls and the difference was statistically significant (p less than 0.01). In OSA patients, MA did not correlate with age, body weight, apnea index, desaturation index, mean nadir-SO2 and lowest SO2. MA was also measured with OSA patients while nasal continuous positive airway pressure (NCPAP) of 10 cmH2O was applied and it was found that MA was significantly widened when NCPAP therapy was performed. We conclude that upper airway narrowing is consistent finding in OSA patients but the degree of narrowing does not correlate with parameters of apnea and gas exchange during sleep, and NCPAP is effective to widen the area of upper airway in OSA patients.

Adult↗
PubMed1991

[Effects of nasal continuous positive airway pressure (NCPAP) on nocturnal renal function in obstructive sleep apnea syndrome (OSAS)].

Nocturnal renal function was examined in 8 patients with obstructive sleep apnea syndrome (OSAS) and the effects of nasal CPAP (NCPAP) on renal function were also studied. Nocturia was observed more than twice in all cases when no treatment was performed, but it disappeared after initiation of NCPAP. Fractional nocturnal urine volume and creatinine clearance decreased significantly from 1.36 +/- 0.15 ml/min to 0.75 +/- 0.20 ml/min (p less than 0.01) and from 116.8 +/- 46.5 ml/min to 101.1 +/- 33.0 ml/min (p less than 0.05), respectively, after initiation of NCPAP. Although the serum Na and creatinine did not change following NCPAP, the urine Na and creatinine changed significantly after NCPAP therapy. The serum renin, aldosterone, and ADH did not change after NCPAP therapy. The significant positive correlation (p less than 0.05) between the fractional nocturnal urine volume and DI, and also significant inverse correlation (p less than 0.05) between the fractional urine volume and %FRC were observed. These results suggest that the abnormal renal function seen in cases of OSAS is related to the hypoxemia during sleep. It was concluded that the nocturnal renal function in cases of OSAS was different from those in normal controls and NCPAP therapy induced the recovery of these abnormalities.

Creatinine↗
PubMed1991

[Effects of continuous lighting on secretion of melatonin and pituitary hormones in women].

Effects of light exposure on the serum concentrations of melatonin, prolactin, LH and FSH were studied in 53 women during their follicular phases. Twenty seven women were exposed to light (500-800 lux at eye level) from 17:30h to 22:00h, and 17 women received the same light intensity from 17:30h to 2:00h, while 9 women stayed in a dark room from 21:00h to 2:00h as control subjects. The light exposure suppressed a nocturnal increase in the serum concentrations of melatonin both at 22:00h and 2:00h. The light exposure and awake condition suppressed the serum prolactin concentrations and increased the serum FSH concentrations at 2:00h, while the influence on the serum LH concentrations was not clear because of LH pulsatility. These results show that the circadian rhythm of melatonin, prolactin and FSH is affected by light exposure and wakefulness, and the effects of light exposure would become more evident if light exposure was continued over a longer period.

Adult↗
PubMed1991

[The development of an antimony electrode with a built-in thermocouple and a temperature-compensated pH meter for the determination of intramyocardial pH during open-heart surgery].

Myocardial acidosis as reflected in pH measured by a glass (G) electrode during ischemic arrest may adversely affect postoperative cardiac function. However, (G) is slow in response and fragile. We report the development of an antimony electrode (Sb) and a pH meter based on our investigation and the results of their clinical application. As a biological material, CPD blood was chosen and subjected to a series of experiments determine its pH by (Sb) and (G). There was a small (within 0.1), but statistically significant difference in pH between (Sb) and (G). To simulate myocardial cooling during operation, CPD blood was cooled and its pH measured by (Sb) and (G). (Sb) showed significantly different behaviour from (G), i,e, the pH tended to fall with the falling temperature, whereas with (G) it tended to rise as had been previously known. The thermodynamic property of (Sb) was checked in appropriate buffer solutions by varying their temperatures. There was an almost linear correlation between EMF by (Sb) and the temperature of the buffer solutions (1 mV/1 degree C, or 0.017 pH/1 degree C). Accordingly, a pH meter incorporating an electronic circuit compensating for the temperature-depending EMF and a (Sb) with a built-in-thermocouple were constructed. Utilizing the new apparatus, CPD blood was again tested and it was proved that the new electrode and the pH meter worked in similar manner to (G). The new apparatus was applied to a series of measurement of intramyocardial pH during open-heart surgery and the results compared with that previously obtained by (G). There were no significant differences either between control pH or rate of its fall in the initial 10 minutes. following aortic cross-clamping and the administration of the cardioplegic solution. It is concluded that although (Sb) is not as accurate as (G), it is a reasonable alternative for the determination of the intramyocardial pH during open-heart surgery.

Cardiac Surgical Procedures↗
PubMed1990

Circumvention of multidrug resistance in P388 murine leukemia cells by a novel inhibitor of cyclic AMP-dependent protein kinase, H-87.

A newly synthesized compound, H-87, N-[2-(p-bromo cinnamylmethylamino)ethyl]-5-isoquinolinesulfonamide was found to be a potent and selective inhibitor of cyclic AMP-dependent protein kinase. The effects of H-87 on in vitro sensitivities of various P388 murine leukemia cell lines resistant to several antitumor agents were examined. H-87 significantly potentiated the cytotoxic effects of Adriamycin (ADR), daunorubicin (DAU), vincristine (VCR) and vinblastine (VBL) on P388 cells resistant to these antitumor agents but hardly influenced the effects of mitomycin C (MMC), 5-fluorouracil (5-FU) and cisplatin (CDDP) on ADR-resistant P388 cells (P388/ADR) and P388 phenotypes resistant to the corresponding antitumor agents. H-87 promoted the accumulation of VBL much more in P388/ADR cells than in the sensitive cells by inhibiting the energy-dependent extrusion of the antitumor agent from the cells. These results suggest that this novel isoquinoline-sulfonamide derivative, H-87, overcomes the multidrug resistance by inhibiting the phosphorylation of an outward drug transport system through cyclic AMP-dependent protein kinase.

Animals↗
PubMed1990

Effects of methanol and urea on optical resolution of phenylthiohydantoin-DL-amino acids by micellar electrokinetic chromatography with sodium N-dodecanoyl-L-valinate.

Effects of methanol and urea on enantiomeric resolution of phenylthiohydantoin (PTH)-DL-amino acids by micellar electrokinetic chromatography with sodium N-dodecanoyl-L-valinate (SDVal) were investigated. PTH-DL-Met that could not be optically resolved with an SDVal solution alone was resolved by using an SDVal/methanol solution. Four PTH-DL-amino acids were separated from each other and each pair of enantiomers was also optically resolved, although seriously tailed peaks were observed for each solute. The addition of urea to SDVal/methanol solutions improved these peak shapes.

Amino Acids↗
PubMed1990

Isolation and partial characterization of two glycoproteins from human liver metastases of sigmoid colon carcinoma.

1. Perchloric acid-soluble glycoprotein fraction (PASF) extracted from human liver metastases (LM) of sigmoid colon carcinoma was chromatographed on a DEAE-cellulose column. The main fraction (DEAE-nonadsorbed fraction) passed through the column was then subjected to Sephacryl S-200 superfine gel filtration and separated into 12 fractions. 2. Among 12 fractions, only both Fractions 3 and 4 were demonstrated to be chemically and immunologically homogeneous glycoproteins, respectively, by a combination of chemical composition analysis, SDS-PAGE and EITB assay using antisera against the DEAE-nonadsorbed fractions of PASFs from human LMs, normal liver (NL) and normal sigmoid colon (NSC). Each of Fractions 3 and 4 reacted with anti-LM serum to give one immuno complex on a nitrocellulose sheet in EITB assay, but did not react with anti-NL and -NSC sera. 3. Apparent molecular weights of 80,900 and 62,100, respectively, were found for Fractions 3 and 4. Both the fractions, respectively, had abnormal sugar compositions. Fraction 3 contained sialic acid, fucose, galactose, N-acetylglucosamine and N-acetylgalactosamine, but lacked glucose and mannose, and Fraction 4 contained sialic acid, fucose, galactose and N-acetylglucosamine, but lacked glucose, mannose and N-acetylgalactosamine, as sugar components.

Glycoproteins↗
PubMed1990

Computational simulation method of intraluminal velocity profile proved by laser Doppler velocimeter.

Measurement of the intraluminal velocity profile within an artery may provide insight into predicting the prognosis of arterial reconstruction. To confirm the results of the computer simulation method a laser Doppler velocimeter using an optical fiber was applied to canine femoral arteries with good or poor runoff, and the intraluminal velocity profile was measured directly. Under normal flow conditions, remarkable fluctuation was obtained at the layer adjacent to the wall, whereas under poor runoff conditions, stagnation of flow was seen at the layer adjacent to the wall. These results showed that our computational simulation method which calculates the intraluminal velocity profile was a reliable, valid method of on-line analysis of the intraluminal velocity profile.

Animals↗
PubMed1990

[Determinant of cardiac hypertrophy in elderly hypertension].

In order to define the factors responsible for cardiac hypertrophy in elderly hypertension, blood pressures and non-hemodynamic humoral parameters were correlated with echocardiographic left ventricular mass (LVM) in 30 elderly hypertensive patients and 30 age-matched normotensive subjects with a mean age of 65 years. Arterial blood pressures were obtained either at the clinic, after supine rest, during maximal exercise test, or with a 24 hour ambulatory monitoring device at 10 minute intervals. Interventricular septum and posterior wall thickness, but not end-diastolic diameter, were significantly increased in the hypertensives than in the normotensives. LVM was significantly correlated with all of te blood pressure parameters, having the strongest association with the mean of ambulatory systolic blood pressures (r = 0.65, p less than 0.001). On the other hand, plasma norepinephrine (r = 0.09), plasma renin activity (r = -0.14), and atrial natriuretic factor (r = -0.08), though known to influence cardiac adaptation to hypertrophy in young or middle aged hypertensives, were not correlated wit LVM. These results suggest that the heart in elderly hypertension is characterized by concentric hypertrophy, the only significant determinant of which appears to be a hemodynamic factor. Unlike younger patients, sympathetic nervous and renin-angiotensin systems may not play an important role in the development of cardiac hypertrophy in the elderly.

Aged↗
PubMed1990

[The effect of short-term nasal CPAP therapy in cases of obstructive sleep apnea syndrome].

Recent studies have shown that nasal CPAP is very effective in the treatment of patients with obstructive sleep apnea syndrome (OSA). To clarify the characteristics of pulmonary function testing and to evaluate the effect of short term nasal CPAP therapy in 13 cases of OSA patients, nasal CPAP was used for 10 to 14 days and polysonography was performed on two consecutive nights without nasal CPAP and at one night with nasal CPAP. Pulmonary function tests and the Uchida-Kraepelin test were performed before the initiation of nasal CPAP therapy and also 7 to 14 days after the nasal CPAP therapy. Apnea index reduced significantly in all cases from 5.10 +/- 19.6 episodes/hour without therapy to 3.1 +/- 3.5 with nasal CPAP (p less than 0.001). Nasal CPAP significantly reduced the frequency of obstructive (p less than 0.001) and mixed apnea (p less than 0.01), but the frequency of central apnea did not change with nasal CPAP. During the nasal CPAP, mean nadir SaO2 rose from 87.3 +/- 2.9% to 92.7 +/- 1.1% (p less than 0.001) and the lowest SaO2 rose from 73.3 +/- 6.4% to 92.0 +/- 2.1% (p less than 0.001). Before the nasal CPAP therapy, daytime PaO2 was 80.6 +/- 6.4 Torr and closing capacity (CC)/FRC ratio was higher when patients were in a supine than in a sitting position. After short term nasal CPAP therapy, daytime PaO2 increased significantly (p less than 0.001), and FRC/TLC in a supine position increased and CC/FRC in a supine position decreased in some patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1990

[Clinical significance of measurement of plasma melatonin concentration in women with irregular menstrual cycles].

To study the effects of melatonin on the human hypophyseal ovarian axis, we measured the concentrations of melatonin in the plasma of women with a regular menstrual cycle and of women with an abnormal menstrual cycle, at days 5 through 10 after the onset of menstruation or withdrawal bleeding. In seven women with a regular menstrual cycle, there was a tendency for the plasma melatonin concentration to gradually decrease chronologically from 49.0 +/- 9.8pg/ml (M +/- S.E.) at 9:30 h to 19.0 +/- 4.0pg/ml at 12:00 h. On the other hand, the plasma melatonin concentration at 21:30 h was 50.3 +/- 7.4pg/ml which was almost the same as the level at 9:30 h, while the concentration during the night significantly increased chronologically to 106.3 +/- 28.6pg/ml at 24:00 h. By comparing the plasma melatonin concentration measured during the day with that measured during the night, a significant difference was discovered after 21:40 h (p less than 0.05). The plasma melatonin concentration at 10:00 h and 22:00 h in 20 women with a regular menstrual cycle was 28.1 +/- 3.4pg/ml and 72.2 +/- 9.9pg/ml, respectively, showing a diurnal rhythm with a significantly higher level during the night than during the day. On the other hand, the plasma melatonin concentration in most of the women with an anovulatory cycle or amenorrhea was within the range of the mean level of +/- 1.5 x the standard deviation obtained from the 20 women with a regular menstrual cycle. However, an increase in plasma melatonin during the night was not found in three of nine women with an anovulatory cycle and one of two women with second grade amenorrhea.(ABSTRACT TRUNCATED AT 250 WORDS)

Circadian Rhythm↗