PubMed Health⌕ Search

Biomedical subjects

H Oura

Publications and source records attributed to H Oura.

At least 37 records · Page 2Linked to original sources
PubMed1997

Inhibitory effect of green tea on injury to a cultured renal epithelial cell line, LLC-PK1.

When cells from a cultured renal epithelial cell line, LLC-PK1, were cultured under hypoxic conditions (oxygen concentration of 2% or less) before reoxygenation was applied (95% air, 5% CO2), the leakage of lactate dehydrogenase (LDH) into the medium increased. This phenomenon was inhibited in the presence of dimethyl sulfoxide, a hydroxyl radical scavenger, suggesting the involvement of free radicals. Such oxidative stress was significantly inhibited by a green tea extract, and more potently by a tannin mixture. On the other hand, under ordinary culture conditions (95%, air, 5% CO2), there was cell injury, although the LDH leakage was less than that under hypoxia/reoxygenation, and such injury was inhibited by the green tea extract and the tannin mixture.

Animals↗
PubMed1996

Immunohistochemical detection of p53 tumor suppressor protein in porokeratosis.

We examined 9 Japanese cases of porokeratosis (4 of the plaque type, 2 of disseminated superficial actinic porokeratosis, 2 of disseminated superficial porokeratosis, and one of giant porokeratosis) for the expression of p53 tumor suppressor protein immunohistochemically, using two anti-p53 antibodies, CM1 and DO1. The same results were obtained with both antibodies. The epidermis central to the cornoid lamellae was positive in 8 of 9 specimens. On the other hand, the peripheral epidermis was positive in 2 of the 9 cases. The epidermis beneath the cornoid lamellae was positive in 3 of the 9 cases. The frequency of p53 positivity was significantly higher in the epidermis central to cornoid lamellae over that beneath or peripheral to them (Fisher's exact probability test, p < 0.05). The majority of squamous cell carcinoma cells arising on giant porokeratosis stained with CM1 and DO1. These data may suggest that the abnormal p53 expression has some relevance to the skin carcinogenesis of porokeratosis.

Adult↗
PubMed1996

Molecular biological analysis of the effects of ginsenoside-Rb2 on albumin mRNA in streptozotocin-induced diabetic rats.

The mechanisms of the mRNA synthesis-promoting action of ginsenoside-Rb2, were investigated at the gene level. Rot analysis suggested that the previously reported increase in RNA polymerase activity as a result of administration of ginsenoside-Rb2 might be because of its effect on a specific gene. In this regard, albumin mRNA, which is expressed specifically in the liver, was assayed by northern blot hybridization using albumin cDNA in normal rats, diabetic control rats and diabetic rats given ginsenoside-Rb2. When the level of albumin mRNA in normal rats was set at 100, the level was reduced markedly to 32 in diabetic control rats. In contrast, in diabetic rats given ginsenoside-Rb2 the level was 0.54, significantly higher (69%) than that in diabetic rats given no ginsenoside-Rb2. In addition, poly(A)+RNA was purified from total RNA and subjected to hybridization, and poly(A)+RNA bands with different charges were measured by densitometry. The results of the measurement revealed changes dependent on the charge, and this was confirmed by autoradiography. We found no significant difference in the transcription activity of albumin mRNA, however, it showed only a tendency to increase. This suggests that ginsenoside-Rb2 has some effect on post-transcriptional regulation of the stability of mRNA itself. The results of Rot analysis suggest that ginsenoside-Rb2 affects a specific gene alone.

Albumins↗
PubMed1996

Clinical and histopathological studies in children with supraventricular tachycardia.

To determine whether myocardial changes in patients with supraventricular tachycardia (SVT) are primary or secondary to persistent tachycardia, 11 patients with SVT were studied. These patients were divided into 2 groups with respect to the type of SVT. Group I consisted of 5 patients with incessant SVT and one with multifocal atrial tachycardia, while group II consisted of 4 patients with paroxysmal supraventricular tachycardia and one with short-run supraventricular premature contraction. All of the patients underwent electrophysiological study and endomyocardial biopsy from the right ventricle following routine cardiac catheterization. In group II, there were no significant abnormalities in the clinical and hemodynamic parameters. In group I, 3 patients had clinical features of dilated cardiomyopathy including abnormal ECG, chest X-ray and hypokinesis on left ventriculography. Induction and termination of SVT were possible in 2 patients in group I and in 4 of the 5 patients in group II. The only significant histologic difference between group I and group II was fibrosis. A high incidence of histopathological abnormalities, such as hypertrophy, degeneration, interstitial fibrosis and disarray was observed in both groups. The incidence of significant pathology was higher in group I than in group II. Almost all of the patients were given antiarrhythmic drugs. One patient underwent a successful surgical procedure and normal cardiac function returned after resection of the foci of the right atrium. Our present results suggest that patients with SVT who have incessant or recurrent SVT should undergo not only intracardiac electrophysiologic study but also endomyocardial biopsy for the evaluation of myocardial damage, since SVT might be the initial sign of cardiomyopathy.

Adolescent↗
PubMed1996

Effectiveness of green tea tannin on rats with chronic renal failure.

The effects of green tea tannin on nephrectomized rats were examined. There were increases in blood urea nitrogen, serum creatinine, and urinary protein, and a decrease in creatinine clearance in the nephrectomized control rats, whereas better results for these parameters were obtained in rats given green tea tannin after nephrectomy, demonstrating a suppressed progression of the renal failure. When the renal parenchyma was partially resected, the remnant kidney showed a decrease in the activity of radical scavenger enzymes. Green tea tannin, however, was found to lighten the kidney under such oxidative stress. Mesangial proliferation and glomerular sclerotic lesions, which were conspicuous in the rats that were not given green tea tannin after nephrectomy, were also relieved.

Animals↗
PubMed1995

Confirmation that magnesium lithospermate B has a hydroxyl radical-scavenging action.

Male LWH: Wistar rats were given creatinine (Cr) intraperitoneally at a dose of 1.00 g/kg body weight, and the urine was collected for 3 h after administration. Magnesium lithospermate B, a compound newly isolated from Salviae Miltiorrhizae Radix, was administered intraperitoneally 30 min before and 30 min after Cr administration. The excretion of urinary creatol and methylguanidine induced by Cr decreased in a dose-dependent manner. Since we have already shown that the main contributor to the Cr-->creatol oxidation step is the hydroxyl radical, magnesium lithospermate B may act as a radical scavenger.

Animals↗
PubMed1995

The promoting action of magnesium lithospermate B on the kinin-prostaglandin E2 system in the kidney.

The effect of magnesium lithospermate B purified from Salviae Miltiorrhizae Radix on the kinin-prostaglandin E2 system was investigated using kidney slices and isolated kidney microsomes. Magnesium lithospermate B markedly increased the amount of thiobarbituric acid-reactive substances produced by incubation of arachidonic acid in renal slices. Enhancement of arachidonic acid-mediated oxygenation of 1,3-diphenylisobenzofuran was also observed in renal microsomes from rats treated with magnesium lithospermate B, indicating an increase of prostaglandin biosynthesis. Furthermore, magnesium lithospermate B significantly increased the synthesis of prostaglandin E2 in renal slices, but the magnesium lithospermate B-mediated response was blunted with kinin antagonist. On the basis of the above results, it is apparent that magnesium lithospermate B exerts an influence on the prostaglandin system via kinin receptors.

Animals↗
PubMed1995

Effects of a component of green tea on the proliferation of vascular smooth muscle cells.

The effects of a component of green tea on the proliferation of smooth muscle cells were measured in terms of [3H]thymidine uptake. When green tea tannin mixture was added to the medium of cultured smooth muscle cells, it suppressed the proliferation of the cells dose-dependently. Similarly to the effects of the green tea tannin mixture, (-)-epigallocatechin 3-O-gallate, its main ingredient, had an inhibitory effect on smooth muscle cell proliferation at a low concentration. (-)-Epicatechin 3-O-gallate was also an effective component. Among four types of gallate-free tannin, (-)-epigallocatechin, (-)-epicatechin, and (+)-catechin showed significant dose-dependent inhibition of smooth muscle cell proliferation. However, caffeine and theanine were found to have no such action.

Animals↗
PubMed1995

Effects of a Dan Shen component, magnesium lithospermate B, in nephrectomized rats.

Magnesium lithospermate B, a compound newly isolated from Dan Shen, was given orally to rats for 70 days after excision of five-sixths of their kidney volume. As a result, mesangial proliferation, tubulo-interstitial lesions and glomerular sclerotic lesions, which were conspicuous in rats that were not given magnesium lithospermate B after nephrectomy, were inhibited. Furthermore, a decrease in blood urea nitrogen, improvement of hypoproteinemia, hypoalbuminemia and hypercholesteremia, and inhibition of urinary protein excretion were observed. The levels of creatinine, methylguanidine and guanidino-succinic acid, which accumulate in the blood with the progress of renal failure, were decreased significantly in rats given magnesium lithospermate B. These results indicate that magnesium lithospermate B, a component of an Oriental medicine has potential as a new therapeutic agent for inhibiting the progression of renal dysfunction.

Animals↗
PubMed1994

Effects of ginseng in nephrectomized rats.

Ginseng extract and its active component, saponin, were administered orally to nephrectomized rats for 90 d, and changes in blood and urine parameters and renal tissue lesions were assessed. Rats given saponin showed a significant decrease in the concentrations of blood urea nitrogen, creatinine and methylguanidine and a significant increase in total protein and albumin in the blood, with reduce urinary excretion of protein. There was also slight amelioration of the degree of mesangial proliferation, the severity of extratubular lesions and glomerular sclerotic lesions, and the extent of tubular interstitial lesions. However, these histological changes were inconspicuous in nephrectomized rats given ginseng extract.

Administration, Oral↗
PubMed1994

Ursolic acid inhibits aflatoxin B1-induced mutagenicity in a Salmonella assay system.

An attempt was made to isolate the active component of Eriobotrya japonica, which inhibits aflatoxin B1-induced mutagenicity in the Salmonella assay system. The number of revertants per plate was significantly decreased when a MeOH extract of Eriobotrya japonica was added to the assay system using Salmonella typhimurium TA100 or TA98. Furthermore, we examined the effect of each fraction purified from the MeOH extract, and an EtOAc fraction was found to be the most effective. Ursolic acid isolated from the EtOAc fraction markedly and significantly decreased the numbers of Salmonella typhimurium TA100 revertants per plate, thus showing antimutagenic activity.

Aflatoxin B1↗
PubMed1994

Decrease in the level of albumin mRNA with progression of renal failure in rats.

Variations in the level of albumin mRNA and the transcription rate of the albumin gene in rats with adenine-induced renal failure were compared with those in normal rats. A paired feeding schedule was employed to eliminate any nutritional differences between normal rats and rats with adenine-induced renal failure. The albumin mRNA level isolated from the liver became lower as the period of adenine administration lengthened. However, there was no difference in the transcription rate of the albumin gene between the two rat groups. These results suggest that a post-transcriptional process is responsible for the renal failure-induced repression of albumin synthesis. Furthermore, plasma glucagon levels in adenine-induced renal failure specimens were markedly higher than those in the normal group, whereas we found no difference in the plasma insulin level between normal and adenine-fed rats. These investigations provide evidence that the decrease in the level of albumin mRNA in renal failure may be partly related to the elevated level of glucagon.

Acute Kidney Injury↗
PubMed1994

[Lung transplantation from non-heart-beating donor following brain death in canine model].

Candidates for pulmonary transplantation have been limited because of extreme susceptibility to lung infections and pulmonary edema in the brain-dead donor. To ameliorate the donor shortage, two possibilities for expanding the donor source have been presented, i.e. xenotransplantation and transplantation from cardiac-dead donors. The present study was conducted to evaluate the possibility of lung transplantation from a non-heart-beating donor following brain death, using a canine model. Six mongrel dogs were put into a state of brain death by elevating intracranial pressure with a balloon catheter. Following the intravenous administration of methylprednisolone and heparin used for 6-hour management following brain death mechanical ventilation was discontinued leading to cardiac arrest with in a few minutes. Excision of the left lung was scheduled for twenty minutes after cardiac arrest, followed by washing out the pulmonary vasculature with cold Ep4 solution, and orthotopic transplantation into the recipient animal. Immunosuppression was achieved with methylprednisolone and azathioprine. A right pulmonary arterial occlusion test (RPAO) was performed to assess graft function immediately and 7 days postoperatively. All but one animal survived and three animals had an uneventful postoperative course, with the transplants alone according to immediate and 7 day postoperative, respectively, RPAO results. These outcomes indicate the possible feasibility of lung transplantation from non-heart-beating donors following brain death.

Animals↗
PubMed1994

Inhibitory effects of ginseng on proliferation of cultured mouse mesangial cells.

To evaluate the pharmacological action of ginseng, its effects on the proliferative activity of mesangial cells, which are thought to play an important role in the regulation of renal function, were determined in terms of [3H]thymidine uptake. When the extract was added to the medium of mesangial cell cultures, it suppressed the proliferation of mesangial cells, and similar proliferation-inhibitory activity was found in the total saponin and ginsenoside-Rd fractions, consistent with the renal effects observed in our previous in vivo studies. The inhibition of mesangial cell proliferation by the extract can thus be explained by the action of ginsenoside-Rd.

Animals↗
PubMed1993

Dispersed cell culture of human sweat duct cells under serum-free conditions.

Human eccrine gland duct cells were successfully cultured using a serum-free medium, K-GM medium. Eccrine sweat ducts were isolated from dispase treated skin specimens from palms or soles. After treatment of the isolated ducts with trypsin and EDTA, dispersed cells were cultured in K-GM medium. In primary cultures, small colonies were seen 3 to 4 days after inoculation. Then the cells rapidly proliferated and formed large colonies with a paving stone-like cell arrangement. During the culture, small dome shaped areas were sometimes formed in the centers of colonies. Cultures multiplied for a maximum of 7 passages. The plating efficiencies of the 1st to 6th passage cells were about 20% to 30%. Immunocytochemically, cultured cells were positively stained with anti-carcinoembryonic antigens, K8.37 and K8.13, but not with anti-S100 protein, anti-HLA-DR, 34 beta B4, or PKK3. An electron micrograph of the cultured cells showed a multilayer of flattened cells linked by desmosomes. These results indicate that the cultured cells possessed the staining properties compatible with those of the ductal portion of eccrine sweat glands. No contamination by other mesenchymal cells, such as fibroblasts, was seen during the culture.

Antigens↗
PubMed1993

L-gulono-gamma-lactone oxidase is the enzyme responsible for the production of methylguanidine in the rat liver.

A methylguanidine-synthesizing enzyme localized in rat liver microsomes produces methylguanidine via the intermediates creatone A and creatone B from the substrate, creatol, a substance produced from creatinine mainly by reaction with hydroxyl radicals. This enzyme has been identified as L-gulono-gamma-lactone oxidase (EC 1.1.3.8). However, no corresponding activity was found in extracts from human livers.

Amino Acid Sequence↗