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Y Chida

Publications and source records attributed to Y Chida.

At least 37 records · Page 2Linked to original sources
PubMed1994

Laterality of theta waves recorded from the bilateral hippocampi in freely moving male rats.

The correlation of rhythmic slow activity (RSA, "theta rhythm") of the rat hippocampus with voluntary movement is well known. However, it is not clear whether there is any difference between the right and left hippocampal function, and profiles of each electroencephalogram (EEG) in the rat. We fixed two paired chronically indwelling electrodes in the bilateral hippocampi, bilaterally enclosing the dorso-ventral structure. It was demonstrated that the distribution of the EEG frequency from the right ventral hippocampus was not the same as that on the other side when the rats were walking in an open area as a novelty environment. Morphological investigation suggested that there was no symmetry in structure between the right and left hippocampi in the rat. In the present investigation, bilateral hippocampal EEGs were also not identical. It is assumed that the left and right hippocampi have different functions in the rat.

Animals↗
PubMed1993

Gastric antisecretory effect of FRG-8813, a new histamine H2 receptor antagonist, in rats and dogs.

FRG-8813, a new histamine H2 receptor antagonist, was examined for antisecretory effects and compared with famotidine and cimetidine in rats and dogs. In pylorus-ligated and lumen-perfused rats, FRG-8813 given i.v. reduced basal gastric acid secretion and the acid secretion evoked by histamine, tetragastrin, bethanechol, and 2-deoxy-D-glucose in a dose-dependent manner. The i.v. antisecretory activity of FRG-8813 was equivalent to or slightly less than that of famotidine and the intraduodenal (i.d.) activity was greater than that of cimetidine. The duration of action of FRG-8813 was substantially longer than that of farmotidine and cimetidine for both i.v. and i.d. routes. The i.v. ED40 values for the histamine- and tetragastrin-evoked responses and the i.v. ED30 value for the bethanechol-evoked response were 0.15, 0.09 and 0.43 mg2kg, respectively. In Heidenhain pouch dogs, when the three H2 antagonists were given i.v. or orally, the relative antisecretory potency of the compounds was similar to that in rats. The long-lasting antisecretory effect of FRG-8813 was also observed, and the i.v. ED50 values for histamine-, tetragastrin- and bethanechol-evoked responses were 0.1, 0.24 and 1.0 mg/kg, respectively. Comparison of the parenteral and enteral potencies indicated that FRG-8813 has a lower bioavailability than famotidine and cimetidine in rats and dogs. These data suggest that FRG-8813 has a potent and long-lasting antisecretory effect with a far greater potency than cimetidine and with a slightly lower potency than famotidine.

Acetamides↗
PubMed1993

Enhanced coagulation and fibrinolysis during treatment with recombinant human erythropoietin in patients undergoing chronic hemodialysis.

Twenty-two patients on regular hemodialysis treatment suffering from renal anemia were treated with intravenous recombinant human erythropoietin (rhEPO) for more than 8 weeks. Before and 4 and 8 weeks after the start of rhEPO administration, we measured prothrombin time, activated partial thromboplastin time, fibrinogen (FBG), antithrombin III activity (ATIII), plasminogen activity (PLG), alpha 2-plasmin inhibitor activity (alpha 2 PI), alpha 2-plasmin inhibitor-plasmin complex (alpha 2 PIC), and cross-linked fibrin degradation products (XL-FDP) in citrated plasma to determine whether rhEPO treatment enhances coagulation and fibrinolytic activity. The pretreatment values of FBG, alpha 2 PIC, and XL-FDP were significantly higher than the normal control values. The pretreatment values of ATIII, PLG, and alpha 2 PI were significantly lower than the normal control values. Platelet count and FBG were significantly increased 4 and 8 weeks after treatment with rhE-PO. The prothrombin time was significantly shortened 8 weeks after rhEPO treatment, but the activated partial thromboplastin time did not change. PLG was significantly decreased 4 and 8 weeks after rhEPO treatment, and ATIII and alpha 2 PI were significantly decreased 8 weeks after rhEPO treatment. alpha 2 PIC was significantly increased 8 weeks after rhEPO treatment, and XL-FDP was significantly increased 4 and 8 weeks after rhEPO treatment. These data suggest that in patients on regular hemodialysis treatment coagulation and fibrinolysis are already enhanced before the start of rhEPO treatment and that rhEPO administration further enhances these disorders.

Adult↗
PubMed1992

Effect of thrombocytopenia on the onset of immune complex glomerulonephritis.

The effect of platelets on the development of immune complex glomerulonephritis (GN) was examined using bovine serum albumin (BSA) GN with platelet depletion. To clarify the role of platelets in the initial stage of BSA GN, thrombocytopenia was induced before BSA infusion. In 18 New Zealand white rabbits, BSA was intravenously injected twice after the presensitization. Eight of these BSA GN rabbits were injected daily with goat anti-rabbit platelet antiserum to induce thrombocytopenia, and platelet counts were maintained below 5 x 10(4)/microliters throughout the experiment. In the thrombocytopenic group, the degree of proteinuria was significantly decreased compared to the control group. Glomerular polymorphonuclear leukocyte infiltration, mononuclear cell proliferation, exudation and glomerular enlargement were significantly suppressed in the thrombocytopenic group. The results suggest that platelets may be quite important in the initiation and development of immune complex GN.

Animals↗
PubMed1992

[Effects of FRG-8813, a new type histamine H2-receptor antagonist, on various experimental gastric and duodenal lesions in rats].

We examined the anti-ulcer effects of FRG-8813, a new type histamine H2-receptor antagonist, on various experimental gastric and duodenal lesions in rats. FRG-8813, administered orally, inhibited the formation of lesions dose-dependently in experimental models with the exception of the Shay ulcer model. The anti-ulcer potency of FRG-8813 was 4 approximately 10 times greater than that of cimetidine when the ED50 values of both compounds were compared. Famotidine and cimetidine inhibited lesion formation at higher doses than the anti-secretory doses. The anti-ulcer action of FRG-8813, however, appeared at even lower doses than those of anti-secretory action. These results suggest that FRG-8813 is able to prevent lesion formation with anti-secretory action plus other mechanisms unlike typical histamine H2-receptor antagonists.

Acetamides↗
PubMed1992

[Effects of FRG-8813, a new-type histamine H2-receptor antagonist, on the healing of gastric and duodenal ulcer in rats and spontaneously ulcerative mice].

We examined the anti-ulcer effects of FRG-8813, a new-type histamine H2-receptor antagonist, in chronic ulcer models of rats and mice (W/WV). FRG-8813, given orally twice a day for 7 days, accelerated the healing of gastric or duodenal ulcer induced by acetic acid injection or application at the non-antisecretory doses (0.3 approximately 3 mg/kg). Administration of FRG-8813 to rats with ulcers increased the amounts of mucus in the gastric mucosa. These actions of FRG-8813 were more potent than those of famotidine or cimetidine. In W/WV mice, several ulcers spontaneously developed on gastric mucosa during the 8 weeks after the birth. The ulcers were aggravated by several unknown factors after the ulcer generation in W/WV mice. The aggravation of ulcers was inhibited by the 4-week administration of FRG-8813 with diet at the dose of 1 or 10 mg/kg/day, but was not inhibited by cimetidine at the dose of 100 mg/kg/day. From these results, we suggest that FRG-8813 is able to accelerate the healing of ulcers by antisecretory plus increasing actions on the integrity of the gastric mucosal defense mechanisms; therefore FRG-8813 is expected to be a useful drug for the treatment of gastric or duodenal ulcers in humans.

Acetamides↗
PubMed1992

Expression and methylation of the beta-subunit gene of prolyl 4-hydroxylase: in erythrocytes, tendon and cornea of chick embryos.

It has recently been demonstrated that the beta-subunit of prolyl 4-hydroxylase (E.C. 1.14.11.2) is the same gene product as protein disulfide isomerase (PDI) and cellular thyroid hormone binding protein (THP). Therefore, it is very likely that the beta-subunit of the prolyl 4-hydroxylase gene serves as a house keeping gene in most cell types. In the present study, we examined the distribution of the chicken beta-subunit of prolyl 4-hydroxylase/protein disulfide isomerase (CPH beta/PDI) in erythrocytes, corneas and tendons of 13-, 17-, and 19-day-old chick embryos by immunohistochemistry using antibodies against CPH beta/PDI. Our data indicate that erythrocytes do not express the CPH beta/PDI gene whereas tendon cells express CPH beta/PDI at all developmental stages examined. The basal cells of corneal epithelium express CPH beta/PDI, but the superficial cell layers of stratified corneas of 19-day-old chick embryos do not. The expression of the CPH beta/PDI gene is also confirmed by in situ hybridization with cDNA encoding CPH beta/PDI. The results indicate that the expression of CPH beta/PDI in cornea is probably developmentally regulated. It has been suggested that methylation of genomic DNA is one of many possible regulatory mechanisms for gene expression. In order to examine whether methylation of genomic DNA may play any role in the expression of the beta-subunit gene, genomic DNA was isolated from corneas, tendons, and erythrocytes of individual 13-, 17-, and 19-day-old chick embryos. DNA samples were digested with Sma I and Eco RI, or Pst I and Sma I and followed by either Msp I, Hpa II, or Hha I and were then subjected to Southern hybridization with 32P-labeled genomic DNA fragments of CPH beta/PDI. Our results indicate that the CPH beta/PDI gene is methylated at the Hha I site in the 4th exon in erythrocytes whereas the same sites in tendon and cornea are hypomethylated. Examination of 5'-end flanking sequences of exon 1 of the CPH beta/PDI gene with the methylation sensitive endonucleases, Hha I and Hpa II did not reveal any difference in erythrocyte, cornea and tendon cells. Thus, our results indicated that DNA methylation may not play an important role in the expression of CPH beta/PDI.

Animals↗
PubMed1992

Enhanced fibrinolytic activity during the course of hemodialysis.

In order to clarify the effect of hemodialysis (HD) on the fibrinolytic system, fibrinolytic activity was evaluated in 27 patients undergoing regular hemodialysis treatment (RDT) using new parameters including plasma alpha 2-plasmin inhibitor (alpha 2 PI), alpha 2-plasmin inhibitor-plasmin complex (alpha 2 PIC), cross-linked fibrin degradation products (XL-FDP), tissue plasminogen activator (t-PA) activity, t-PA antigen and plasminogen activator inhibitor-1 (PAI-1) antigen. Predialysis baseline levels of plasminogen and alpha 2PI activity in RDT patients were significantly lower and those of alpha 2PIC were significantly higher than normal control values. During a single HD session, alpha 2PIC exhibited a continuous, significant increase reaching about 180% of initial values by the end of HD. alpha 2PI activity was significantly decreased at the end of the HD, though there were no significant changes in plasminogen activity during HD. Predialysis baseline levels of XL-FDP in RDT patients were significantly higher than normal control values. No significant changes in XL-FDP were observed during HD. Both t-PA activity and t-PA antigen significantly increased during HD, and PAI-1 antigen significantly decreased during HD. Von Willebrand factor (vWF) antigen in plasma, which is regarded as reflecting a release reaction by vascular endothelial cells to certain stimuli, also significantly increased during HD. However, neither vWF antigen nor t-PA antigen was increased by heparin administration alone. The changes in alpha 2PI and alpha 2PIC levels suggest that fibrinolytic activity is slightly higher in RDT patients and is even higher during HD.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1992

Long-term effects of steroid treatment on nephrotic syndrome associated with Kimura's disease and a review of the literature.

A 68-year-old Japanese male (Case 1) and a 59-year-old Japanese male immigrant to Brazil (Case 2) who suffered from subcutaneous eosinophilic lymphoid granuloma (Kimura's disease) of several years duration, developed nephrotic syndrome. Renal biopsy demonstrated membranous nephropathy in Case 1 and minimal-change lesion in Case 2. Both patients were treated with prednisolone for several months. There was complete remission of nephrotic syndrome in eight years in Case 1 and in three months in Case 2. Proteinuria did not reappear after remission of nephrotic syndrome in either case. In contrast subcutaneous tumors subsided in both cases during steroid treatment but again became active immediately following discontinuation of the drug. These clinical observations suggest that, though some common factor(s) might mediate the development of both skin and renal lesions, the mechanism of action on these two target organs may differ, perhaps serving only as a "trigger" for the initiating mechanism of renal disease.

Aged↗
PubMed1991

Coagulation and fibrinolysis in patients with chronic renal failure undergoing conservative treatment.

Eighteen patients with chronic renal failure due to primary glomerular disease undergoing conservative treatment (CRF patients) were studied to evaluate whether coagulation and fibrinolytic activity in plasma are enhanced in the patients. We measured plasma levels of coagulation-fibrinolysis parameters including thrombin-antithrombin III complex (TAT) (an index of thrombin formation), alpha 2-plasmin inhibitor (alpha 2 PI)-plasmin complex (alpha 2 PIC) (an indicator of plasmin production) and cross-linked fibrin degradation products (XL-FDP) (an index of fibrinolysis secondary to coagulation). There was no correlation between plasma levels of TAT, alpha 2PIC and XL-FDP and serum creatinine levels in CRF patients. Both fibrinogen and TAT were found to be significantly higher in CRF patients than in normal controls. TAT was negatively correlated with serum albumin or total protein. Antithrombin III (ATIII) activity was significantly lower in CRF patients than in normal controls. CRF patients showed significantly but slightly higher alpha 2 PIC and XL-FDP when compared to normal controls. These results suggest that TAT, alpha 2PIC and XL-FDP are good indicators of coagulation-fibrinolysis even in patients with decreased renal function. Coagulation activity is significantly increased in CRF patients but fibrinolysis secondary to coagulation is only slightly enhanced.

Adult↗
PubMed1991

Enhanced coagulation-fibrinolysis in patients on regular hemodialysis treatment.

Thirty-three patients with chronic uremia on regular hemodialysis treatment (RDT) have been studied to determine whether coagulation and fibrinolysis are enhanced or not. We examined predialysis values of coagulation and fibrinolysis parameters including alpha-2-plasmin inhibitor-plasmin complex (alpha 2PIC), a good index of in vivo plasmin production, and cross-linked fibrin degradation products (XL-FDP), an index of fibrinolysis secondary to coagulation. Fibrinogen was significantly higher (p less than 0.001) in RDT patients than in normal controls. ATIII activity was significantly lower in RDT patients than in normal controls (p less than 0.001). Plasminogen activity and alpha-2-plasmin inhibitor (alpha 2PI) activity were significantly lower (p less than 0.001) in RDT patients than in normal controls. Alpha 2PIC and XL-FDP were both significantly higher (p less than 0.001) in RDT patients than in normal controls. XL-FDP was inversely correlated with alpha 2PI (r = -0.486, p less than 0.01) and positively correlated with alpha 2PIC (r = 0.646, p less than 0.001). These results suggest that coagulation and fibrinolysis are enhanced in RDT patients and that the enhanced fibrinolysis is mainly due to fibrinolysis secondary to coagulation.

Adult↗
PubMed1990

Plasma von Willebrand factor and thrombomodulin as markers of vascular disorders in patients undergoing regular hemodialysis therapy.

Increased plasma levels of von Willebrand factor antigen (vWF:Ag) are regarded as reflecting the release reaction by vascular endothelial cells and/or endothelial cell injury, and increased levels of thrombomodulin (TM) antigen as reflecting damage to endothelial cells. We investigated changes in plasma vWF:Ag and TM antigen levels during the course of regular hemodialysis treatment (RDT) in 14 patients undergoing RDT in order to evaluate the effect of hemodialysis (HD) on endothelial cells. vWF:Ag and TM were both measured by the sandwich EIA method. Predialysis levels of vWF:Ag and TM in RDT patients were both significantly higher than normal control values. Neither patient age nor blood pressure was not correlated with predialysis vWF:Ag and TM levels. Both vWF:Ag and TM levels significantly increased during a single HD session. There was a positive correlation between predialysis TM levels and duration of HD and an inverse correlation between the amount of vWF:Ag released during HD and duration of HD. It appears that HD procedures induce stimulation and damage of endothelial cells and that long-term, recurrent HD treatment may predispose to vascular disorders.

Adult↗
PubMed1990

Effects of FRG-8701 on gastric acid secretion, gastric mucosal lesions by necrotizing agents and experimental gastric or duodenal ulcer in rats.

Effects of FRG-8701, a new histamine H2-receptor antagonist, on gastric acid secretion, necrotizing agents-induced gastric lesions and acute gastric or duodenal ulcer in rats were studied. In lumen-perfused rats, intravenous injection of FRG-8701 reduced gastric acid secretion, and its antisecretory effect was almost equipotent to that of famotidine but the duration of action was substantially longer. In pylorus-ligated rats, the antisecretory effect of intraduodenal FRG-8701 administration was about 7 times more potent than that of cimetidine. FRG-8701 effectively inhibited macroscopic gastric hemorrhagic lesions induced by various kinds of necrotizing agents. Intraperitoneal injection was effective in preventing the lesions as well as oral treatment. The oral ED50 values for these lesions ranged from 1.1 to 9.4 mg/kg. On the other hand, famotidine failed to reduce these lesions, and the cytoprotective effect of cimetidine was observed only in high doses compared with the doses for antisecretory activity. In addition, the cytoprotective effect of FRG-8701 was not affected by the treatment of indomethacin or N-ethylmaleimide. FRG-8701 showed antiulcer activity against stress and indomethacin gastric ulcer and mepirizole duodenal ulcer. Its antiulcer effect was 5-15 times more potent than that of cimetidine. These results indicate that FRG-8701 is a new antiulcer drug that exerts a potent cytoprotective effect in addition to its gastric antisecretory activity.

Acetamides↗
PubMed1990

[A case of systemic lupus erythematosus associated with cryptococcal meningitis which was successfully cured by the administration of massive dose of amphotericin B].

A case of SLE with moderately deteriorated renal function due to lupus nephritis developed cryptococcal meningitis. Long term administration of amphotericin B (cumulative dose 5 g) combined with 5-flucytosine eradicated this fungal infection. Throughout amphotericin B administration urinary excretions of Na and K, as well as plasma HCO3 concentration were monitored, and, Na, K and HCO3 were supplemented orally and intravenously so much as to replace their urinary losses. Neither prominent water-electrolyte disturbance nor severe azotemia, which are the most serious side effects of amphotericin B, did not ensue. This case study indicates that sufficient water.electrolytes supplementation is important to prevent the nephrotoxicity of amphotericin B.

Adult↗
PubMed1989

[Effects of hemodialysis on left ventricular performance: a Doppler echocardiographic study].

Left ventricular systolic and diastolic performance was examined using Doppler and M-mode echocardiography in 42 patients with chronic renal failure before and after hemodialysis. Twenty patients with left ventricular hypertrophy, 22 without hypertrophy and 30 normal subjects were studied. Chronic renal failure patients showed significantly larger chamber diameters of the left ventricle, left atrium and right ventricle than did normal subjects. This group also exhibited greater fractional shortening, stroke volume and cardiac output. Before hemodialysis, patients with left ventricular hypertrophy had a significantly higher cardiac output and the greater ratio of late to early diastolic peak flow velocities (A/R) than did patients without hypertrophy. After hemodialysis, there were significant reductions in blood pressure, ventricular and atrial dimensions, stroke volume and cardiac output. The velocities of early and late diastolic left ventricular filling and the deceleration rate were also significantly reduced. The heart rate, A/R, deceleration half time, and the ratio of deceleration half time to acceleration half time (DHT/AHT) were significantly increased. The greater the amount of fluid removed, the greater the changes in the above values. Patients with left ventricular hypertrophy exhibited significant reductions in fractional shortening, ejection fraction, stroke volume and cardiac output, compared to those without hypertrophy. However, patients without hypertrophy showed more significant decrease in the acceleration half time and increase in DHT/AHT than did patients with hypertrophy. These findings demonstrated normal systolic function and impaired diastolic properties in patients with chronic renal failure, who had left ventricular hypertrophy unaccompanied by dilatation.

Adult↗
PubMed1989

Multiplication of the dictyosome during the formation of autospores in the green alga Chlorococcum infusionum.

Numerical changes in dictyosomes during the formation of autospores in a green alga, Chlorococcum infusionum, were investigated by electron microscopy. Two dictyosomes were seen near the nucleus in young vegetative cells. Four dictyosomes were seen in large mononucleate cells which appeared to enter mitosis soon. Binucleate cells contained 4 or 8 dictyosomes, the latter number being found in the large binucleate cells. Large tetranucleate cells contained 16-25 dictyosomes in each cell. Dictyosomes consisted of about 4 cisternae with a diameter of 0.4-0.6 micron in mono- to tetranucleate cells. Cytokinesis began with the formation of the septa during the third nuclear division, and 16 cells were finally formed. Dictyosomes did not increase in number in 8- and 16-nucleate cells. In septum-forming cells, dictyosomes were 0.6-1.0 microns in diameter, with 6-9 cisternae. A single dictyosome was included in each of the 16 resultant cells. These observations suggest that the dictyosomes multiply in association with the multiplication of the nuclei without correlation with formation of the cell wall or cytokinesis.

Chlorophyta↗
PubMed1988

Cross-physical dependence of several drugs in methaqualone-dependent rats.

We investigated the characteristics of physical dependence on methaqualone. Rats were made physically dependent on methaqualone by the use of the drug-admixed food (DAF) method for 33 days. Pentobarbital, barbital, ethanol and diazepam were cross-administered against methaqualone to evaluate the degree of suppression of methaqualone withdrawal signs as an index for the cross-physical dependence liability of these drugs to methaqualone. To evaluate the cross-physical dependence liability, we used AUC of body weight loss and withdrawal scores between the first cross-administration (9 hr after the withdrawal) and 27 hr after the withdrawal. AUC of weight loss was significantly suppressed by the four test drugs as compared to each control. Withdrawal scores were also significantly inhibited by the cross-administration of barbital, ethanol and diazepam. Considering that the rats given barbital or ethanol fell asleep after the cross-administration, diazepam seems to cause the strongest suppression of methaqualone withdrawal signs among the four test drugs. Thus, physical dependence on methaqualone may be similar by nature to that on benzodiazepines rather than barbiturates and alcohol.

Animals↗