Search PubMed⌕ Search

Biomedical subjects

T Ohkawa

Publications and source records attributed to T Ohkawa.

At least 163 records · Page 9Linked to original sources
PubMed1988

The effect of an acute maternal stress on beta-endorphin and growth hormone releasing factor in the rat fetus.

Pregnant rats were injected with saline or L-tyrosine methylester HCl (200 mg/kg) and subjected to an acute forced immobilization stress on day 20 of gestation. At 10, 30, 60, and 120 minutes after the onset of stress, their fetuses were dissected out, and the contents of hypothalamic and pituitary immunoreactive beta-endorphin (IR-beta-EP) and hypothalamic immunoreactive growth hormone-releasing factor (IR-GRF) were determined by specific radioimmunoassays. The maternal stress arose a significant decrease of hypothalamic IR-beta-EP at 30 minutes, while pituitary IR-beta-EP slightly elevated at 30 minutes, then declined at 60 minutes. Hypothalamic IR-GRF showed a gradual increase during the maternal stress. Tyrosine supplementation tended to attenuate stress-induced changes in hypothalamic and pituitary IR-beta-EP, but the response of hypothalamic IR-GRF was less modified by tyrosine. These results showed the functional changes in fetal central beta-EP and GRF under maternal stress in the late gestational life, and suggested that catecholaminergic regulations participate, at least in part, in the fetal neuroendocrine response to maternal stress.

Animals↗
PubMed1988

Effect of single or chronic injection with a carbamate, propoxur, on the brain cholinergic system and behavior of mice.

Propoxur, an anticholinesterase carbamate, was injected singly (10 mg/kg, s.c.) or chronically (5 mg/kg/day, s.c., for 10 days) into mice. Animals were examined for effects on the cholinergic system in brain tissue and on behavior. Single injection caused an increase in brain acetylcholine (ACh) content at 10 and 60 min; and it caused decreases in acetylcholinesterase (AChE) activity at 10, 60 and 180 min, high-affinity choline uptake into synaptosomes at 10 and 60 min, and [3H]quinuclidinyl benzilate (QNB) binding at 10 min without causing any change in choline acetyltransferase (ChAT) activity. Open-field behavior and rotarod performance were depressed at 10 min and rectal temperature was decreased at 10, 60 and 120 min after a single injection. Chronic treatment caused decreases in high-affinity choline uptake and [3H]QNB binding 24 hr after the final injection without any changes in ACh content, AChE activity or ChAT activity. In behavioral tests conducted 10 min prior to daily administration, rotarod performance was slightly suppressed only during the period of injection. Although propoxur is considered to have effects similar to those of organophosphorus compounds, the changes observed in the present experiments seemed to be reversible.

Animals↗
PubMed1988

Electrical tolerance of the Chara corallina plasmalemma.

[Ca2+]o controls at least three distinct electrical phenomena in the Chara plasmalemma. 1). Increase of the electrical tolerance. 2). Decrease of the G without a marked change of the Gp/Gd ratio. 3). Elevation of the threshold for excitation (data not shown). On the other hand, [Mg2+]o shows quite opposite effects. Thus, optimum [Ca2+]o and [Mg2+]o are expected in vivo. Voltage dependencies of various conductances in the Chara plasmalemma are schematically shown in Fig. 4.

Biological Transport, Active↗
PubMed1988

[Citrate (CG-120) therapy for urolithiasis. 1. Clinical effects].

Urinary citrate is an important determinant for crystallization of calcium salts, and recently oral administration of citrate has been suggested to be clinically useful in the management of renal stone disease. The effect of CG-120, a citrate compound (potassium citrate, sodium citrate and citric acid) produced by Dr. Madaus (Germany), on upper urinary tract stones was investigated in 398 patients in this study group. The patients were treated with 3 or 4 g CG-120 daily. Two hundred thirty-one of them were treated accurately according to the protocol of the study for more than 32 weeks. The cumulative percentage of positive clinical effect for the stone (disappearance, passage or decrease in size) was 30.3% (70/231). There were no differences in the clinical effect between the group of 3 g/day and the group of 4 g/day. CG-120 seemed to be more effective in the cases of ureteral stone, young patients and females, but was less effective in the recurrent stone formers. Although there were 45 episodes of side effects in 38 patients in this study, no serious side effects attributed to CG-120 were experienced. CG-120 was proved as a useful drug in the treatment of upper urinary tract calculi as well as its prevention.

Adolescent↗
PubMed1988

[Citrate (CG-120) therapy in urolithiasis. 2. Effect on urinary and serum biochemistry ].

The long-term effects of citrate therapy (CG-120, 3 g/day or 4 g/day) were examined in 398 patients with upper urinary tract calculi. We studied the influence of citrate therapy on urinary and blood biochemistry in 353 of them. CG-120 caused a sustained increase in urinary citrate, urinary pH and potassium, but no substantial or significant changes in other urinary parameters (uric acid, phosphate, oxalate, sodium, chloride and urine volume). Although urinary calcium decreased significantly up to the 24th week, it did not change significantly there after and it tended to increase at the 54th week. Urinary creatinine excretion decreased after 34 weeks of administration, but this phenomenon could not be explained, because the level of blood urea nitrogen and serum creatinine was not elevated in any case before administration. There were no changes in the serum calcium, magnesium, phosphate, uric acid, sodium, potassium or chloride level.

Blood Chemical Analysis↗
PubMed1988

[Clinical studies on the measurement of urinary tissue polypeptide antigen (TPA) levels using Prolifigen TPA kit "Daiichi"-II in urothelial cancers].

We have investigated the clinical significance of urinary tissue polypeptide antigen (TPA) as a tumor marker for urothelial cancers. Urinary TPA levels were determined by the immunoradiometric assay of Prolifigen TPA Kit "Daiichi"-II in 486 healthy controls and 1835 patients with various diseases including 526 with urothelial cancers and 140 with prostatic cancer. The mean value of urinary TPA was 199 +/- 213 (1SD)U/1 in 486 healthy controls. 95% of them having a level below 600 U/l. Therefore, 600 U/l was applied as a cut-off level. Positive rates of urothelial cancers and reactivated prostatic cancer were 57.6% (148 of 248 cases) and 45.5% (5 of 11 cases) respectively. On the other hand, the false positive rate of most urological benign diseases was only about 20% except for the acute stage of urinary tract infections and upper urinary tract stones with hydronephrosis. There was no significant difference in the positive rate between urinary TPA level and urinary cytology in urothelial cancers. The combination of both tests raised the positive rate to 73.1%. Therefore, urinary TPA may be useful in the monitoring of urothelial cancers, and the combination of urinary TPA and urinary cytology may increase the diagnostic accuracy.

Antigens, Neoplasm↗
PubMed1988

[A modification of the estimation of urinary oxalate using a Sigma kit].

The Sigma kit for estimating urinary oxalate is an enzymatic procedure. However, some errors were encountered using the standard assay system of the kit. Firstly, an overestimate of oxalate may arise from the oxidation of ascorbate during the alkaline wash stage of the extraction of oxalate from urine. Secondly, an underestimate of oxalate may occur because of incomplete extraction of oxalate. A modified assay system for measurement of urinary oxalate using the kit is reported. The following points were modified: urine was diluted two-fold with 0.2 M EDTA and and 0.2 M citrate buffer (pH 3.0), oxalate from urine was extracted with 0.06 N sodium hydroxide to prevent the overestimation by the oxidation of ascorbate, and a plate mixer and addition of a small magnet to the vial were used in the steps of both absorption and extraction of oxalate to keep the accuracy of the estimation. The linearity of standard curve, reproducibility and recovery rates of the modified method were studied, and good results were obtained (linearity; r = 0.999, CV of reproducibility; 5.3%, recovery rate; 101% (300 microM) and 103% (600 microM). A good correlation was seen between the modified Sigma method and high performance liquid chromatography (r = 0.991).

Chromatography, High Pressure Liquid↗
PubMed1987

[Sexual differentiation of social play and copulatory behavior in prenatally stressed male and female offspring of the rat: the influence of simultaneous treatment by tyrosine during exposure to prenatal stress].

The environmental stress in the late gestational life has been reported to induce impairments of androgen-dependent sex differentiation of the rat brain. This study was performed to investigate the effects of prenatal stress on the features of gender role behavior and copulatory behavior which are masculinized by perinatal androgens. Further, a possible counteraction of tyrosine to the long-term effects of prenatal stress was examined, because the supplementation of amino-acid precursor of catecholamines during the stress is known to maintain the content of catecholamines in the brain, which is considered to contribute to the differentiation of the brain. Time-mated pregnant females were subjected to the forced immobilization stress daily from day 15 of pregnancy to the day of delivery, and they received simultaneous i.p. injections of either tyrosine methylester HCl (200 mg/kg) or saline, less than 60 minutes before stress. Social play in the peripubescent period was observed in the male and female offspring. After maturation, they were castrated and male copulatory behavior under androgen-substitution was tested in the male offspring, and female copulatory behavior under estrogen-substitution was tested in the female offspring. In the male offspring, prenatal stress caused a significant depletion of social play as well as male copulatory behavior, showing the demasculinization of gender role centers and mating centers. In the female offspring exposed to the prenatal stress, a significant increase of social play was observed. And their lordosis quotient did not alter, but a reduced attractivity against male partner was found. These results in the female offspring suggest some extent of masculinization occurred in both centers, probably due to the increase of androgens derived from the adrenal glands when stressed. Tyrosine seemed to reduce the engagement of social play in both sexes, independently of the prenatal stress. On the other hand, tyrosine prevented, at least partially, the long-term effects of prenatal stress in copulatory behavior which were observed in this study. Tyrosine itself had no effect on copulatory behavior. The apparent counteraction of tyrosine in copulatory behavior suggests a positive involvement of catecholamines, especially norepinephrine, in the process of masculinization of the mating centers. The different action of tyrosine to these behaviors may reflect the fact that the different regions of the brain and separate mechanisms are responsible for the sexual differentiation of social play and copulatory behavior.

Animals↗
PubMed1987

Adjuvant chemotherapy for invasive bladder cancer.

From June 1982 through December 1985, 25 patients who had undergone radical cystectomy with pelvic node dissection for pathologic stage-pT3 or -pT4 and/or N+ disease received adjuvant chemotherapy involving the injection of cis-platinum alone or in combination with adriamycin and 5-fluorouracil (CAF). Thirteen patients also received preoperative adjuvant chemotherapy involving the infusion of cis-platinum, adriamycin, and mitomycin C into the bilateral internal iliac arteries. Postoperative adjuvant chemotherapy was performed using the following two protocols. Protocol 1 (18 cases) consisted of cis-platinum alone being administered every week for 3 weeks and then every month for 1 year. In protocol 2 (7 cases), cisplatinum, adriamycin, and 5-fluorouracil were administered at 3-week intervals on three occasions and then every month for 1 year. Eighteen patients were still alive with no evidence of disease after an average of 26 months. One patient died as a result of factors unrelated to cancer. Local recurrence and distant metastasis occurred in 6 patients, of whom 3 were still alive for an average of 20.7 months. Three patients died of cancer progression after 9, 19, and 21 months. The survival rate for all 25 patients at 50 months was 77%. Nausea and vomiting occurred in most patients during the administration of cis-platinum. Mild myelosuppression developed in a few patients subjected to protocol 2. Our results indicate that adjuvant chemotherapy consisting of the administration of cis-platinum alone or in combination with other chemotherapeutic agents appears to be effective in patients with invasive bladder cancer.

Aged↗
PubMed1987

Percutaneous dissolution of uric acid calculi with THAM irrigation.

We describe two patients suffering from uric acid calculi; one had uremia due to obstruction in one kidney, and the other retained fragments after percutaneous nephrolithotomy. They were successfully treated by irrigation of a THAM (tris-hydroxy-methyl-aminomethane) solution through percutaneous nephrostomy.

Aged↗
PubMed1987

Passive transfer of experimental allergic encephalomyelitis with lymphocytes collected from brains of immunized guinea pigs.

Lymphocytes were collected from the brains of guinea pigs immunized with syngeneic spinal cord emulsified in complete Freund's adjuvant. Sixteen to 32 X 10(6) lymphocytes were inoculated into the vein of each inbred guinea pig (NIH 13). Recipient animals without clinical signs of experimental allergic encephalomyelitis (EAE) were sacrificed 20 days later. Some of the recipients had perivascular infiltrates of a large number of mononuclear cells mostly in choroid plexus and meninges of the brain and spinal cord. Demyelination, which was not so intense, was also observed in the vicinity of the perivascular infiltrates. Thus, the lymphocytes from the brain as well as lymph node and spleen were clear to have the ability to transfer EAE.

Animals↗
PubMed1987

Effect of dietary calcium and magnesium on experimental renal tubular deposition of calcium oxalate crystal induced by ethylene glycol administration and its prevention with phytin and citrate.

Oral administration of ethylene glycol to rats, and the resultant intratubular depositions of microcrystals of calcium oxalate were studied investigating the influences of dietary calcium or magnesium and assessing the protective efficacies against the crystallizations by treatment with phytin and sodium citrate. With increase of calcium intake and consequent increase of urinary calcium excretion there was a marked increase in the amount of tubular deposit of calcium oxalate crystal and in the calcium content of renal tissue. Although magnesium deficiency accelerated renal tubular calcium oxalate deposition, the protection against the crystal formation was not observed with excessive dietary magnesium. When rats were fed a high-calcium diet supplemented with phytin, a significant inhibition of the intratubular crystallization was observed. It appeared obvious that a hypocalciuric action of phytin was attributed to the effect of the prevention. There was vigorous protection of crystal formation by treatment with sodium citrate, which correlated with the level of citrate concentration in the drinking water.

Animals↗