Search PubMed⌕ Search

Biomedical subjects

M Hirose

Publications and source records attributed to M Hirose.

At least 379 records · Page 21Linked to original sources
PubMed1994

Induction and promotion of forestomach tumors by sodium nitrite in combination with ascorbic acid or sodium ascorbate in rats with or without N-methyl-N'-nitro-N-nitrosoguanidine pre-treatment.

In experiment I, short-term effects of combined treatment with anti-oxidants, sodium ascorbate (NaAsA) and sodium nitrite (NaNO2) on forestomach cell proliferation were examined in F344 male rats. Groups of 5 animals aged 6 weeks were treated for 4 weeks with 0.8% catechol, 0.8% hydroquinone, 1% tert-butyl-hydroquinone (TBHQ), 2% gallic acid or 2% pyrogallor alone or in combination with 0.3% NaNO2 in the drinking water and/or 1% NaAsA in the diet. The thicknesses of forestomach mucosa in rats treated with anti-oxidants and NaNO2 in combination were greater than those with antioxidant alone and additional NaAsA treatment further enhanced the thickening of mucosa. It was noteworthy that values for mucosae of animals treated with NaNO2 and NaAsA without anti-oxidant were similar to those for anti-oxidants. In experiment 2, effects of combined treatment with NaAsA or ascorbic acid (AsA) and NaNO2 on carcinogenesis were examined in F344 male rats with or without N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) pre-treatment. Groups of 20 or 15 rats, respectively, aged 6 weeks, were given a single intra-gastric administration of 150 mg/kg body weight of MNNG in DMSO:water = 1:1 or the vehicle alone by stomach tube. Starting 1 week later, they received supplements of 1% NaAsA or 1% AsA in the diet and 0.3% NaNO2 in drinking water in combination, each of the individual chemicals alone, or basal diet until the end of week 52. In MNNG-treated animals, incidences of forestomach papillomas and carcinomas were significantly enhanced in the NaNO2 alone group (84 and 47%, respectively) as compared with the basal diet group (30 and 10%), with further significant increase in carcinomas occurring with additional NaAsA (79%, p < 0.05) or AsA (85%, p < 0.05) treatment. In animals without MNNG, all animals in the NaNO2 group demonstrated mild hyperplasia, additional administration of NaAsA or AsA remarkably enhancing the grade of hyperplasia, and resulting in 53% and 20% incidences, respectively, of papillomas. Thus NaNO2 was demonstrated to exert promoter action for forestomach carcinogenesis, with NaAsA and AsA acting as co-promoters. The results strongly indicate that combined treatment with NaAsA or AsA and NaNO2 may induce forestomach carcinomas in the long term.

Animals↗
PubMed1994

Carcinogenicity of 4-methoxyphenol and 4-methylcatechol in F344 rats.

The carcinogenic potentials of 4-methoxyphenol (4-MP) and 4-methylcatechol (4-MC), phenolic compounds which are structurally similar to the known forestomach carcinogen BHA and the glandular stomach carcinogen catechol respectively, and cause considerably enhanced cell proliferation and cytotoxicities in rat forestomach and/or glandular stomach epithelium, were examined in male and female F344 rats. Groups of 30 male and female animals were administered diets containing 2% 4-MP or 2% 4-MC for 104 weeks. Histopathological findings in the 4-MP case included atypical hyperplasias (male, 67%, female, 37%), papillomas (50%, 23%) and squamous-cell carcinomas (77%, 20%) in the forestomach. 4-MC induced forestomach papillomas (70%, 93%) and squamous-cell carcinomas (53%, 37%), also glandular stomach submucosal hyperplasias (90%, 93%), adenomas (100%, 100%) and adenocarcinomas (57%, 47%), with ulceration or erosion. The degree of differentiation of the squamous-cell carcinomas induced by 4-MP was less than with 4-MC. The present study demonstrated unequivocal forestomach carcinogenicity for 4-MP and forestomach and glandular stomach carcinogenicity for 4-MC, with cytotoxicity and cell proliferation both appearing as important factors for these non-genotoxic carcinogens.

Animals↗
PubMed1994

Right atrial pressure and forearm blood flow during prolonged exercise in a hot environment.

Right atrial pressure (RAP) at rest is known to be reduced by an increase in skin blood flow (SkBF) in a hot environment. However, there is no clear evidence that this is so during exercise. To clarify the effect of the increase in SkBF on RAP during exercise, we measured forearm blood flow (FBF) (as an index of SkBF) and RAP continuously using a Swan-Ganz catheter in five male volunteers exercising on a cycle ergometer at 60% of peak aerobic power for 50 min in a hot environment (30 degrees C, relative humidity 20%). Cardiac output increased from 5.5 +/- 0.2 l/min at rest to 17.9 +/- 1.2 l/min (mean +/- SE, P < 0.01) in the first 10 min of exercise and then remained steady until the end of exercise. FBF did not change significantly during the first 5 min, but then increased from 2.7 +/- 0.5 ml/100 ml per min at rest to 10.8 +/- 1.7 ml/100 ml per min (P < 0.001) by 25 min as pulmonary arterial blood temperature (Tb) rose from 37.0 +/- 0.1 degrees C to 38.1 +/- 0.1 degrees C (P < 0.001). FBF then reached a plateau, despite a continuing increase in Tb. RAP increased significantly from 4.3 +/- 0.8 to 7.6 +/- 1.2 mm Hg (P < 0.001) during the first 5 min of exercise and then gradually declined to 6.1 +/- 1.0 mm Hg by 25 min (P < 0.001 vs. 5 min) and further to 5.7 +/- 1.0 mm Hg by 50 min, a value not significantly higher than at rest.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1994

Modification of N-butyl-N-(4-hydroxybutyl)nitrosamine-initiated urinary bladder carcinogenesis in rats by phytic acid and its salts.

The effects of dietary phytic acid and its salts on the promotion stage of two-stage urinary bladder carcinogenesis were examined. Male F344 rats were initiated by exposure to 0.05% N-butyl-N-(4-hydroxybutyl)nitrosamine in the drinking water for 4 wk, and then treated with basal diet containing a 2% supplement of phytic acid (PA), phytic acid dodecasodium salt (Na-PA), phytic acid dodecapotassium salt (K-PA), phytic acid hexamagnesium salt n-hydrate (Mg-PA) or no added chemical for 32 wk. Na-PA significantly increased the development of preneoplastic and neoplastic lesions of the urinary bladder. K-PA also brought about a tendency for increase in papillomas, whereas Mg-PA and PA were without effect. Both Na-PA and K-PA caused elevation of urinary pH, and Na+ or K+ concentration, respectively. These results confirm the promoting activity of the sodium salt of phytic acid for urinary bladder carcinogenesis and indicate modulation by urinary components, as demonstrated by increases in urinary pH, and Na+ concentration.

Animals↗
PubMed1994

Autoregulation of transcription of the hupA gene in Escherichia coli: evidence for steric hindrance of the functional promoter domains induced by HU.

The molecular mechanism of autoregulation of expression of the hupA gene in Escherichia coli was examined. The promoter of the gene contains a palindromic sequence with the potential to form a cruciform DNA structure in which the -35 sequence lies at the base of the stem and the -10 sequence forms a single-stranded loop. An artificial promoter lacking the palindrome, which was constructed by replacing a 10 nucleotide repeat for the predicted cruciform arm by a sequence in the opposite orientation, was not subject to HU-repression. DNA relaxation induced by deleting HU proteins and/or inhibiting DNA gyrase in cells results in increased expression from the hupA promoter. We propose that initiation of transcription of the hupA gene is negatively regulated by steric hindrance of the functional promoter domains for formation of the cruciform configuration, which is facilitated at least in part by negative supercoiling of the hupA promoter DNA region. The promoter region of the hupB gene also contains a palindromic sequence that can assume a cruciform configuration. Negative regulation of this gene by HU proteins may occur by a mechanism similar to that operating for the hupA gene.

Bacterial Proteins↗
PubMed1994

Effects of combined treatment with phenolic compounds and sodium nitrite on two-stage carcinogenesis and cell proliferation in the rat stomach.

The effects of combined treatment with NaNO2 and phenolic compounds on N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) stomach carcinogenesis were investigated in F344 rats. In the first experiment, groups of 15-20 male rats were treated with an intragastric dose of 150 mg/kg body weight of MNNG, and starting 1 wk later, were given 2.0% butylated hydroxyanisole, 0.8% catechol, 2.0% 3-methoxycatechol or basal diet either alone or in combination with 0.2% NaNO2 in the drinking water until they were killed at week 52. All three antioxidants significantly enhanced forestomach carcinogenesis without any effect of additional NaNO2 treatment. However, in the absence of MNNG pretreatment, the grade of forestomach hyperplasia in the catechol and 3-methoxycatechol groups was significantly increased by the combined treatment with NaNO2. In a second experiment, the combined effects of various phenolic compounds and NaNO2 on cell proliferation in the upper digestive tract were examined. Groups of 5 rats were given one of 24 phenolic compounds or basal diet either alone or in combination with 0.3% NaNO2 for 4 weeks and then killed. Particularly strong enhancing effects in terms of thickness of the forestomach mucosa were seen with t-butylhydroquinone (TBHQ), catechol, gallic acid, 1,2,4-benzenetriol, dl-3-(3,4-dihydroxyphenyl)-alanine and hydroquinone in combination with NaNO2. In the glandular stomach, similar enhancing effects were evident in 11 cases, and in the esophagus with phenol, TBHQ and gallic acid. These results demonstrate that NaNO2 can augment cell proliferation induced in the stomach epithelium by various phenolic compounds.

Animals↗
PubMed1994

Immunohistochemical analysis of cytokeratin expression in eccrine spiradenoma: similarities to the transitional portions between secretory segments and coiled ducts of eccrine glands.

Despite light and electron microscopic and histochemical studies, there is no consensus on the cellular differentiation of eccrine spiradenoma. In the present study, eight specimens of eccrine spiradenoma were analysed by immunohistochemical techniques, using a panel of monoclonal antibodies against cytokeratins. Two types of epithelial cells were identified in tumour nodules: large, pale epithelial cells in the centre, and small, dark epithelial cells situated at the periphery. These nodules frequently contained tubular structures lined by cuboidal, columnar or, less commonly, flattened epithelial cells. Cytokeratin expression in eccrine spiradenoma was compared with expression in normal eccrine glands. Immunohistochemistry revealed that large, pale epithelial cells expressed immunophenotypes similar to those of luminal cells in the transitional portions between the secretory portions and the coiled ducts. The small, dark cells expressed immunophenotypes similar to those of basal cells in the transitional portions. Tubular structures observed in eccrine spiradenoma showed staining patterns similar to those of the luminal cells in the transitional portions. Eccrine spiradenoma may, therefore, differentiate towards the transitional portions between the secretory portions and coiled ducts of eccrine glands. Some of the large, pale epithelial cells in eccrine spiradenoma differentiate towards tubular structures, forming a lumen lined by a cuticle.

Adenoma, Sweat Gland↗
PubMed1994

Splenectomy for treatment of immunoblastic lymphadenopathy.

A 5-month-old girl was diagnosed with immunoblastic lymphadenopathy (IBL) on the basis of clinical symptoms and pathological findings. alpha-interferon, immunosuppressive agents such as cyclosporin A, deoxyspagarine, and azathioprine, and an alternating regimen of low-dose 6-mercaptopurine, cyclophosphamide and methotrexate were tried with partial success. Finally, splenectomy was carried out at 58 months of age, inducing prolonged complete remission without any medication.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1994

Effect of nicotine in migration and proliferation of rabbit gastric mucosal cells in a culture cell model.

The aim of this study was to assess the effects of nicotine on the gastric epithelial restoration using primary cultured rabbit gastric mucosal cell model. Confluent monolayer mucosal cell sheets consisting of mainly mucous cells were wounded using a rotating silicon tip. The process of restoration was monitored, and the size of wound was measured and analysed quantitatively. Artificial wounds recovered in 36 h in controls. The nicotine treatment (10(-5), 10(-4) and 10(-3) mol/L) did not cause any effects on the process of wound repair. Bromodeoxyuridine (BrdU) positive cells appeared around the wound 24-36 h after injury and then disappeared after the complete repair in controls and also in nicotine-treated groups. However, in the morphological observation, numerous vacuoles were detected in parietal cells of nicotine-treated groups. This effect of nicotine was reversible by removing nicotine from the medium. Present data suggest that nicotine has no direct effects on the mucosal restoration but might have an effect on the structure and function of parietal cells.

Animals↗
PubMed1994

Combined intrauterine and ovarian pregnancy: a case report.

A case of combined intrauterine and ovarian pregnancy diagnosed by postoperative microscopic observations is reported in this paper. The patient was a 23-year-old, Japanese nulligravid female. On the 32 day after a previous D & C when normal chorionic tissues of very early gestation were obtained, she complained of severe lower abdominal pain. Immediate laparotomy revealed hemorrhaging from a hematoma-like region on the surface of the left ovary, and partial resection of the left ovary was performed. The resected ovary was composed of an intact corpus luteum and another thin corpus luteum around a hematoma-like region containing chorionic villi, confirming this case to be an ovarian pregnancy. Histological findings of chorionic villi of the ovary indicated that ovarian pregnancy took place during the same menstrual period as intrauterine pregnancy, and not after the prior D & C. From these observations, this case was diagnosed as a combined intrauterine and ovarian pregnancy.

Abortion, Induced↗
PubMed1994

Right atrial pressure and ANP release during prolonged exercise in a hot environment.

To investigate the relationship between right atrial pressure (RAP) and atrial natriuretic peptide (ANP) release during prolonged exercise in a hot environment (30 degrees C, 20% relative humidity), we studied with a Swan-Ganz catheter five male volunteers exercising on a cycle ergometer at 60% of peak aerobic power for 50 min. The ANP level increased from 14 +/- 3 (SE) to 69 +/- 10 pg/ml (P < 0.001) during the first 10 min of exercise as RAP rose from 4.3 +/- 0.8 to 6.9 +/- 1.1 mmHg (P < 0.001). The 10-min ANP level was significantly correlated with RAP (r = 0.88, P < 0.05) but not with heart rate, pulmonary arterial blood temperature, plasma norepinephrine, or plasma epinephrine. The 10-min RAP value was inversely correlated with blood volume (r = -0.98, P < 0.01) and also with stroke volume (r = -0.96, P < 0.01). In the next 20 min of exercise, ANP continued to increase to 101 +/- 12 pg/ml (P < 0.02 vs. 10 min) and remained at this level until 50 min of exercise, whereas RAP decreased and reached a level not significantly different from baseline at 50 min (5.7 +/- 1.0 mmHg; P < 0.01 vs. 10 min). This dissociation of ANP and RAP may have been related to the significant increases from the 10-min values of heart rate, blood temperature, norepinephrine (all P < 0.01), and epinephrine (P < 0.02) during the same period. These results suggest that ANP release is primarily controlled by atrial distension at the onset of exercise but that other stimulators may be involved thereafter.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1994

The effect of the partial pressure of oxygen on blood glucose concentration examined using glucose oxidase with ferricyan ion.

Glucose oxidase with ferricyan ion (GOD-F) is widely applied in clinical settings as a glucose sensor. However, blood oxygen concentration affects this blood glucose value because oxygen, at increased concentrations, consumes blood glucose, which cannot then be measured by this sensor. We investigated the effect of PO2 on blood glucose concentration in 48 patients who were breathing high concentrations of oxygen. Arterial and pulmonary arterial blood glucose values were analyzed using the GOD-F method and, as a control, the hexokinase method. The respective PO2 values were also measured. The blood glucose concentrations measured by the GOD-F method show a significant linear relation with that measured by the hexokinase method in both arterial (y = -24.4 + 1.01x, r = 0.99) and pulmonary arterial blood (y = -3.4 + 1.01x, r = 0.96). The difference of intercepts is statistically significant, but because of the relatively large limits of agreement indicating any hidden extraneous variabilities, the error of the GOD-F method could not be assessed just by the difference. The equation defining the effect of PO2 on the percent change between blood glucose measured by the GOD-F method and that measured by the hexokinase method is -19.8/(1 + 203900/PO2(2.68) (r = 0.62). This formula generally follows our measured materials and introduces the relationship among blood glucose value, PO2, and the error of the GOD-F method. We hesitate to suggest that the arterial blood glucose concentration when measured by the GOD-F method could be underestimated by as much as 20% in patients with high arterial oxygen pressure.(ABSTRACT TRUNCATED AT 250 WORDS)

Anesthesiology↗
PubMed1994

Early changes in volume and non-enhanced volume of acoustic neurinoma after stereotactic gamma-radiosurgery.

The effectiveness of stereotactic gamma-radiosurgery for treating acoustic neurinoma was evaluated by measuring the volumes of the tumor, non-enhanced tumor, and cerebellar edema in 13 patients with acoustic neurinoma who were followed up for 9 to 15 months (median 12.7 mos) after treatment. The tumor volume and non-enhanced volume tended to reach a maximum after 6 months, and cerebellar edema volume after 9 months, then decreased gradually thereafter. Hearing loss tended to increase gradually, but involvement of the facial nerve was transient.

Aged↗
PubMed1994

Reinforcement of cyclosporin A-induced red cell destruction by superoxide.

To determine the mechanism of hemolysis following organ transplantation, we studied the effect of immunosuppressants and/or superoxide (SO) on the in vitro destruction of red cells. The immunosuppressants tested included cyclosporin A (CyA), deoxyspagarine (DSG), and FK506. SO was obtained from the hypoxanthine-xanthine oxidase reaction. Of the three immunosuppressants studied, only CyA affected the size of red cells and directly produced hemolysis in an isotonic buffer without the involvement of an immune mechanism. In addition, SO and CyA showed a synergistic effect on hemolysis during prolonged incubation. Catalase and allopurinol prevented hemolysis by counteracting the activity of SO. In that SO is produced in excess during the recovery of blood flow after organ transplantation, the prolonged contact of red cells with CyA and SO may be involved in the development and reinforcement of hemolysis in vivo.

Adult↗
PubMed1994

Experimental study of lung transplantation from non-heart-beating donor following brain death in canine model of left lung allotransplantation.

Thirty mongrel dogs were divided into 3 groups. Group I was a normal control group (n = 4) without transplantation procedure. Group II was a transplantation control group (n = 5) with left lung allotransplantation from heart-beating donor. Group III consisted of animals (n = 8) which received lung allografts from non-heart-beating donor following brain death. In Group III, brain death was brought about by intracranial hypertension with the inflation of balloon in the subdural space of donor. After 6 hours, the mechanical ventilation was discontinued followed by cardiac arrest. Left lung was excised twenty minutes after the cardiac arrest and was washed out with cold Ep4 solution for subsequent orthotopic allotransplantation. Right pulmonary arterial occlusion test (RPAO) were carried out under right thoracotomy to evaluate graft function immediately and 7 to 14 days after the surgery. PaO2, PAP and CO were measured before and 20 minutes after RPAO. All animals in Group II and 7 of 8 animals in Group III survived more than 7 days after surgery. No significant differences in the value of PaO2, mean PAP and TPVR with RPAO among three groups at each time of assessment, showing the possibility of lung transplantation from non-heart-beating donor followed by brain death.

Anesthesia↗
PubMed1994

[A case of adult respiratory distress syndrome treated with 5 ppm nitric oxide inhalation].

A cases of adult respiratory distress syndrome, ARDS, was treated with nitric oxide (NO) inhalation for 10 days. The optimal dose of inhaled NO was determined by the dose-response relationship with NO concentration ranging from 5 to 160 ppm. 5 ppm of NO inhalation considerably increased PaO2 and decreased mean pulmonary arterial pressure (mPAP). Further increase in concentration of inhaled NO did not result in remarkable change in PaO2, but decreased mPAP. NO inhalation therapy was begun with 20 ppm of NO and 0.95 of FIO2, and on the 6th day NO concentration was decreased to 5 ppm with 0.7 of FIO2. In this case of ARDS, FIO2 could be sufficiently decreased and PaO2 maintained at more than 60 Torr with 5 ppm NO inhalation.

Administration, Inhalation↗