PubMed Health⌕ Search

Biomedical subjects

N Ohnuma

Publications and source records attributed to N Ohnuma.

At least 91 records · Page 5Linked to original sources
PubMed1991

[The role of magnetic resonance imaging for treatment in children with malignant solid tumor].

Magnetic resonance imaging (MRI) was performed in 126 children with malignant solid tumor between April 1984 and December 1990. The criteria of tumor visualization, localization, staging, prediction of kidney preserving and monitoring treatment were compared by MRI and CT for 47 children with neuroblastoma, Wilms' tumor, hepatoblastoma, rhabdomyosarcoma and teratoma, MRI and CT were viewed together and an assessment was made as to whether the studies yielded equivalent information or whether one study was superior to the other. 1) The tumor were better visualized in 47% cases by MRI than CT. 2) MRI was superior to CT in 43% cases in evaluating the local spread of tumor. 3) There was little difference between MRI and CT in identification of lymph node metastases. 4) Without requiring the injection of intravenous contrast agents, MRI accurately defined displacement, invasion of renal vessels by neuroblastoma. MRI was excellent in prediction of kidney preserving. 5) MRI was useful to detect bone marrow metastases in neuroblastoma. The best imaging plane for a demonstration of bone marrow involvement was coronal in lower limbs.

Abdominal Neoplasms↗
PubMed1990

Novel natriuretic peptide, CNP, potently stimulates cyclic GMP production in rat cultured vascular smooth muscle cells.

The newly identified peptide C-type natriuretic peptide (CNP) caused only a slight elevation of cGMP in rat renal glomeruli. In contrast, CNP potently increased cGMP levels in cultured rat vascular smooth muscle cells (VSMC) and stimulated guanylate cyclase activity in the particulate fraction of the cells. The extent of maximum activation of the enzyme induced by CNP was 4-fold higher than that by human atrial natriuretic peptide (alpha-hANP) while CNP was 4- and 16-fold weaker than alpha-hANP in binding affinity for the putative receptors on VSMC and vasorelaxant activity for rat aorta, respectively. These results indicate that CNP is a potent stimulator of cGMP formation in VSMC but not in glomeruli and pharmacological feature of CNP is distinct from that of ANP.

Amino Acid Sequence↗
PubMed1990

[Targeting anticancer chemotherapy dispersed in lipid contrast medium in hepatoblastoma in childhood].

Fourteen cases of malignant liver tumor in childhood were experienced in our department during past 14 years. Since 1984 we have performed preoperative targeting anticancer chemotherapy using oily anticancer agents such as THP-adriamycin 30 mg/m2. These oil emulsion was making with 20 mg amounts of THP-adriamycin dissolved in 5 ml urographin and 15 ml volume of lipiodol. These mixture were administered by catheterizing the hepatic artery under X-ray monitoring in 6 cases with hepatoblastoma. Remarkable anticancer effects of this targeting chemotherapy were achieved, the serum AFP level and tumor size both showing a decrease in all cases, and the resectability of tumor showing a increase in 5 among 6 cases in comparison with 50% resectability before 1983.

Adolescent↗
PubMed1990

[Study of crystalline drugs by means of a polarizing microscope. XI. Analysis of the particle size distribution of a principle agent in a trituration of phenytoin].

By the immersion method with a polarizing microscope a principle agent phenytoin was identified from its 10 times trituration containing vehicles such as lactose and starch. A particle size distribution of phenytoin crystals in its trituration was determined by observing one of the habit parameters b from all the detectable particles of phenytoin under a microscope in a suspension of an immersion oil, nD: 1.555, in which phenytoin crystals having key refractive indexes, n1: 1.606, n2: 1.631, were clearly detectable from other vehicles. By the similarity of crystal habits in the same lot the particle size distribution of phenytoin crystals in its trituration was calculated from the values of observed parameter b and average values of habit coefficients, T(square root of ab/c): 2.004, L(b/a): 2.545, which were obtained from some previously identified phenytoin crystals.

Crystallization↗
PubMed1989

Differential stimulation of rat lung particulate guanylate cyclase activity by atrial natriuretic peptide and sodium nitroprusside.

The effects of alpha-rat atrial natriuretic peptide (alpha-rANP) and sodium nitroprusside on the activity of rat lung particulate guanylate cyclase were examined. The particulate guanylate cyclase in partially purified rat lung membranes was stimulated by both alpha-rANP and nitroprusside. The effects of alpha-rANP and nitroprusside were, however, not additive. Diamide and N-ethylmaleimide almost completely abolished the nitroprusside-mediated stimulation, while they had only moderate effects on the alpha-rANP-mediated stimulation of the enzyme activity. ATP potentiated the enzyme stimulation by alpha-rANP, whereas it had no effect on the nitroprusside-mediated stimulation. These findings suggest that the stimulation of lung particulate guanylate cyclase activity by alpha-rANP and nitroprusside is mediated by different mechanisms.

Animals↗
PubMed1988

Tumor imaging by antineuroblastoma monoclonal antibody and its application to treatment.

Antineuroblastoma monoclonal antibody (MoAb) was labeled with iodine-131 (131I) and injected into transplantable human neuroblastoma-bearing nude mice in vivo. Imaging of the tumor by gamma camera was then attempted. At the fourth day after injection of the antibody, relatively heavy labeling was observed in the tumor. Principal organs were removed and their 131I uptake was determined. A high radioactivity count was detected in the tumor, indicating efficacy of this antibody in tumor imaging of neuroblastoma. This antibody was labeled with 131I and injected into transplantable human neuroblastoma-bearing mice. Apparent inhibition of tumor growth was observed in animals treated as such compared with animals of the control group, MoAb alone group, and 131I alone group (P less than 0.05). In addition, pathohistologic study showed binding of 131I to tumor cells and necrotic changes, suggesting the possibility of application of this MoAb to the treatment of neuroblastoma.

Animals↗
PubMed1988

Stimulation of guanylate cyclase activity by irreversible binding of atrial natriuretic peptide to its receptor.

We examined receptor binding profiles of atrial natriuretic peptide (ANP) in rat tissue using 125I-labeled alpha-rat ANP [( 125I]alpha-rANP). Specific [125I]alpha-rANP binding to its receptor was reversible following addition of unlabeled free alpha-rANP, but it became increasingly irreversible with time during incubation. Irreversible binding of alpha-rANP was observed both at 0 degrees and 25 degrees in homogenates of adrenal capsules and lungs, crude membranes of renal glomeruli, partially purified membranes of lung, solubilized membrane preparations from renal glomeruli, and intact renal glomeruli. Irreversible binding increased in a time- and temperature-dependent manner. HPLC analysis demonstrated that the irreversibly bound radioactivity, which was extracted by 1 N CH3COOH from both intact renal glomeruli and from partially purified membranes, was associated with intact [125I]alpha-rANP. Irreversibly bound alpha-rANP increased cGMP concentrations by activating guanylate cyclase activity. These findings suggest that the appearance of irreversible binding of alpha-rANP to its receptor is independent of its internalization, and may be involved in message transduction and subsequent biological responses.

1-Methyl-3-isobutylxanthine↗
PubMed1988

Protective effect of alpha-human atrial natriuretic polypeptide (alpha-hANP) on chemical-induced pulmonary edema.

It has been established that alpha-hANP, the newly discovered peptide extracted from human cardiac atria, has potent natriuretic and hypotensive actions. Our present investigation is the first to demonstrate that alpha-hANP is capable of protecting against pulmonary edema caused by various chemicals, using isolated perfused guinea pig lung system. Lungs were perfused via pulmonary artery with Krebs-Ringer bicarbonate buffer at 5.0 ml/min, and wet weight of lungs and perfusion pressure of pulmonary artery (Pa) were monitored. Bolus injection of Triton-X or CHAPS into cannulated pulmonary artery produced edema as indicated by a massive increase in wet weight and a slight increase in Pa. Constant infusion of alpha-hANP through pulmonary artery at 200 ng/ml was effective in causing decrease in wet weight of lung. Perfusion of lung with paraquat or PGF2 alpha, and repeated bolus injection of arachidonic acid or PGE2 caused elevation in both wet weight of lung and Pa. The treatment with alpha-hANP similar to that described above also protected against edema caused by paraquat or arachidonic acid. Bolus administration of epinephrine induced a slight increase in wet weight and Pa, and alpha-hANP was effective in decreasing the elevated lung wet weight and Pa of lungs. Infusion or bolus administration of alpha-hANP into control lungs increased cGMP level in outflow perfusate as well as in lung tissue significantly. In lungs with edema which were induced by Triton-X or paraquat, there was a slight increase in cGMP level in Triton-X treated and no increase in paraquat treated lung tissues. In either cases, was there any increase in cGMP level in perfusate. The specific binding study of [125I]alpha-hANP revealed that the lack of increase in cGMP was not due to a loss of receptor in Triton-X or paraquat treated lungs. Thus our study demonstrated that alpha-hANP had a direct anti-edematic action(s) in lung which was not secondary to the systemic natriuretic and/or hypotensive action(s).

Animals↗
PubMed1988

[Diagnosis of anterior perineal anus (APA)--significance of electromyographic evaluation of the external anal sphincter location].

APA is a common cause of constipation, and is the mild case of the imperforated anus. On diagnosing APA, anterior displacement of the anus and normal distribution of the external anal sphincter to the anus are essential. To determine the location of the anus in the perineum simple clinical technique was developed. In 61 normal cases, the result of measurement was almost same in each sex, but in 3 APA cases the location were anteriorly dislocated than normal cases. Distribution of the external anal sphincter was evaluated with electromyographic technique, and location map of the sphincter was made. In 3 APA cases, the anus was totally surrounded by the external anal sphincter, but in 17 ano-cutaneous fistula cases, the opening was anteriorly dislocated to the sphincter distribution map. As a conclusion, newly proposed simple clinical technique to determine anal location and electromyographic examination of the external and sphincter distribution are very useful in objective diagnosis of APA.

Anal Canal↗
PubMed1988

[Delayed primary operation of solid tumors in children].

Delayed primary operation has been started since 1982 in our department and 19 cases of solid tumor in childhood were treated with this method. They included 11 cases of advanced neuroblastoma, 5 cases of hepatoblastoma and 3 cases of yolk sac tumor in sacrococcygeal area. We discussed effectiveness of preoperative chemotherapy to the primary tumor and metastatic lesions, the best timing of operation after chemotherapy and the operative technique in delayed primary operation. Preoperative chemotherapy were useful in almost all cases of delayed primary operation, so the primary lesion and lymph nodes metastases were removed easily. We recommended it was the best timing of operation when 2 or 3 courses of preoperative chemotherapy were finished. CUSA (Cavitron Ultrasonic Surgical Aspirator) was the useful instrument to remove the primary tumor and lymph node metastases completely in advanced neuroblastoma preserving both kidneys.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1987

Radioimmunodetection of neuroblastoma with antineuroblastoma monoclonal antibody.

The Antineuroblastoma monoclonal antibody CNM-5 was submitted to preclinical studies and then used for tumor imaging with following results. 1. CNM-5 is an antibody which belongs to the IgM fraction and has a molecular weight of 900 kilodaltons. Its protein concentration was found to be 17.99 mg/dl. 2. The 131I-labeled antibody was injected into nude mice transplanted with human neuroblastoma, and imaging was performed by a gamma camera. Accumulation of 131I in the tumor was relatively clearly seen. Various organs were removed and examined for 131I uptake. Radioactivity was easily detected in the tumor, suggesting that CNM-5 is effective for use in imaging diagnosis of neuroblastoma.

Animals↗
PubMed1987

Kinetics of cytotoxic T lymphocytes in stage IV-S neuroblastoma.

The kinetics of cytotoxic T lymphocytes (CTL) in a patient with stage IV-S neuroblastoma were examined for 2 months. CTL were detectable during the preoperative and postoperative periods in this stage IV-S neuroblastoma patient, in spite of the tumor-bearing condition. Furthermore, the patient's mother showed the same level of CTL. This experiment suggests that patients with stage IV-S neuroblastoma have a constantly high level of CTL, and that this immunologic response is predominantly hereditary.

Adrenal Gland Neoplasms↗
PubMed1987

Alpha-human atrial natriuretic peptide (alpha-hANP) prevents pulmonary edema induced by arachidonic acid treatment in isolated perfused lung from guinea pig.

Protective effect of alpha-human atrial natriuretic peptide (alpha-hANP) on pulmonary edema was investigated using an isolated perfused lung model. Infusion of alpha-hANP (1.7 to 22 ng/ml or 0.56 to 7.3 nM) prevented the edema induced in isolated lung from guinea pig by repeated treatment of 50 micrograms of arachidonic acid at 30 min intervals via the pulmonary artery. The antiedematic action of alpha-hANP was considered to be receptor mediated because the effective concentration was close to the Kd value of the binding of the ANP receptors in the lung homogenate.

Animals↗
PubMed1987

Rat atrial natriuretic polypeptide increases net water, sodium and chloride absorption across rat small intestine in vivo.

Localization of binding sites for synthetic rat atrial natriuretic polypeptide (alpha-rANP) and the effect of the peptide on net water and electrolyte movement in vivo perfused small intestine of the rat were studied. Autoradiographic study demonstrated that specific binding sites were localized on a space between the base of epithelia and lamina propria of the small intestine. Alpha-rANP (0.25 micrograms/min) infused into the superior mesenteric artery of rats increased net absorption of water (46% increase in comparison with controls), Na (84% increase) and Cl (70% increase) across the small intestinal tract perfused with Ringer's solution. These increases were also observed when glucose-free Ringer's solution was employed. Thus it would be concluded that the Na-glucose cotransport system is not involved in the action of alpha-rANP. These observations suggest that alpha-rANP controls circulating water-electrolyte balance through regulating not only renal function but also intestinal water, Na and Cl absorption.

Animals↗
PubMed1987

[Effectiveness of cis-dichlorodiammine-platinum in the treatment of advanced neuroblastoma].

Twenty cases of advanced neuroblastoma treated at the Pediatric Surgical Department of Chiba University from 1975 through 1985 were discussed. Cis-dichlorodiammineplatinum (CDDP) and VM-26 were administered to 7 patients with disseminated neuroblastoma resistant to treatment with cyclophosphamide, doxorubicin and vincristine. One complete remission, 4 partial remissions, and 2 minor responses were observed in our series. These results were far better than in our previous study, in which patients were treated with regimens containing cyclophosphamide, doxorubicin and vincristine. Several kinds of side effects were observed in children treated with CDDP. Vomiting occurred in all of them, and bone marrow toxicity was found in 5 among 7 patients. There was one case of severe nephrotoxicity caused by severe proximal tubular dysfunction with increased urinary loss of sodium, leading convulsion.

Adrenal Gland Neoplasms↗