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Biomedical subjects

K Itoi

Publications and source records attributed to K Itoi.

At least 55 records · Page 3Linked to original sources
PubMed1991

Localization of the substance P-induced cardiovascular responses in the rat hypothalamus.

Intracerebroventricular injection of substance P (SP) has been reported to induce a typical cardiovascular defense response characterized by an increase in blood pressure, heart rate, sympathetic efferent activity, hindlimb vasodilatation and mesenteric vasoconstriction. In this study we employed microinjections of SP to localize the hypothalamic areas in which SP elicits the activation of the cardiovascular system. SP (550 pmol) injected into the anterior hypothalamus (AH) produced, after a short latency, a marked increase in mean arterial pressure and heart rate. In the ventromedial hypothalamus, the magnitude of the cardiovascular response to SP was identical to that in the AH, but the response was delayed. SP injected into the posterior hypothalamus failed to induce any cardiovascular response. These results suggest that the anterior and ventromedial parts of the hypothalamus are responsible for eliciting the central cardiovascular effects of SP in conscious rats.

Animals↗
PubMed1991

Immunoreactive endothelin in urine of patients with and without diabetes mellitus.

Immunoreactive (ir)-endothelin (ET) in urine was studied with a radioimmunoassay in patients with diabetes mellitus (DM) and non-DM diseases including endocrine disorders, primary glomerular diseases, autoimmune diseases, and hematological malignancies. Twenty-four-hour excretions (mean +/- SEM) of ir-ET were 8.0 +/- 0.9 pmol/day in the DM group (n = 13) and 9.5 +/- 1.2 pmol/day in the non-DM group (n = 51). No significant differences among DM and other disease groups were noted with respect to 24-h ir-ET excretion. Reverse-phase high-performance liquid chromatography of a normal urine extract revealed a major peak eluting later than ET-1. Gel chromatography revealed a single major peak in a smaller molecular weight (MW) region in normal urine and an additional peak in larger MW region in a urine extract from a DM patient. Urinary ir-ET consists of at least two components which may be metabolites of ET or ET precursors in plasma or peptides derived from the kidney.

Adolescent↗
PubMed1991

Immunoreactive endothelin in pheochromocytomas.

The presence of endothelin (ET) in tumor tissue and plasma of patients with pheochromocytoma was studied by radioimmunoassay. Immunoreactive (ir-) ET concentrations in 12 pheochromocytomas ranged from 66 to 253 fmol per gram wet tissue (gwt) (146 +/- 20 fmol/gwt, mean +/- SEM). These values were not significantly higher than tissue ir-ET concentrations of two primary aldosteronism (66 and 132 fmol/gwt) and three normal adrenal glands (71-120 fmol/gwt) (0.05 less than p less than 0.1). However, tumor tissue ir-ET concentrations in six of the 12 pheochromocytomas were higher than 132 fmol/gwt (the upper value of the control tissues). Sephadex G-50 column chromatography and reverse-phase high-performance liquid chromatography of pheochromocytoma tumor extracts showed a major peak eluting at an identical position to synthetic ET-1. Plasma ir-ET concentrations of pheochromocytomas (1.4 +/- 0.9 fmol/ml, n = 17) were not significantly different from those of patients with essential hypertension (1.0 +/- 0.7 fmol/ml, n = 20) and normal subjects (1.0 +/- 0.4 fmol/ml, n = 18) (0.05 less than p less than 0.1). This study has shown that high concentrations of ET-1 are present in tumor tissues of 50% of pheochromocytomas.

Adrenal Gland Neoplasms↗
PubMed1991

Cornexistin: a new fungal metabolite with herbicidal activity.

Cornexistin, a new compound demonstrating promising herbicidal activity, was purified from the culture filtrate of a newly-isolated fungus identified as Paecilomyces variotii SANK 21086. The compound was extracted with organic solvents from the culture filtrate, purified using column chromatography on Sephadex LH-20 and finally crystallized from methylene chloride. Following analysis of its physico-chemical properties it was identified to be a new compound belonging to the nonadride group. Chemical structure elucidation was conducted by analyses of various spectral data and the structure was finally confirmed by means of X-ray crystallographic analysis. Based on its herbicidal characteristics cornexistin may be classified as a postemergence herbicide active against certain young annual and perennial monocotyledonous and dicotyledonous plants with selective protection for corn.

Chromatography↗
PubMed1991

Hydantocidin: a new compound with herbicidal activity from Streptomyces hygroscopicus.

Hydantocidin, a new compound with potent non-selective herbicidal activity, was found in a submerged culture of Streptomyces hygroscopicus SANK 63584. It was isolated from the culture filtrate by the following successive treatments comprised of activated carbon, Diaion HP-20, Dowex 50WX4, and Avicel column chromatographies. Finally it was crystallized as colorless needles from acetone. The molecular formula, C7H10N2O6, was determined by analyses of HRFAB mass spectrum in conjunction with 13C NMR spectrometry. The structural elucidation revealed that it has a unique structure with a spiro-bond between ribose and hydantoin moieties in the molecule. The characteristic herbicidal activities against annuals as well as perennials, including monocotyledonous and dicotyledonous weeds, were observed.

Animals↗
PubMed1990

Release of neuropeptide Y from pheochromocytomas.

To investigate the release of neuropeptide Y (NPY) from the pheochromocytomas, we studied the relationship between the plasma and tumor tissue immunoreactive (IR) NPY concentrations in 13 patients with pheochromocytoma and measured the IR-NPY concentration in plasma samples obtained by catheter from several veins (jugular veins, superior vena cava, renal veins, adrenal veins and inferior vena cava) in 2 patients with pheochromocytoma. The plasma IR-NPY concentration in 13 patients with pheochromocytoma ranged from 118 to 1460 pg/ml and the concentration in 10 of 13 patients with pheochromocytoma was above 290 pg/ml (the upper limit of normal range). The tumor tissue IR-NPY ranged from 0.025 to 95.3 micrograms/g wet tissue. Plasma IR-NPY was parallel with tumor tissue IR-NPY in 13 cases of pheochromocytoma (r = 0.76, P less than 0.01). The highest concentration of IR-NPY was found in plasma obtained from the drainage vein from a tumor among the plasma samples obtained from several veins in 2 cases of pheochromocytoma. These findings indicate that in patients with pheochromocytoma, NPY is in most cases excessively released from the tumors into the systemic circulation and plasma IR-NPY in the periphery is increased.

Adrenal Gland Neoplasms↗
PubMed1990

[A case of mediastinitis caused by rupture of esophageal diverticulum].

A 42-year-old male student from abroad visited a department of internal medicine of a hospital because of fever and dyspnea. A diagnosis of purulental mediastinitis with empyema was made. After drainage of the right thoracic cavity, the patient was referred to our department. Although consecutive treatment consisting of administration of antibiotics and thoracic drainage was conducted, dyspnea became worse, and widening of the mediastinum become severer. Mediastinal drainage was done via the parasternal approach under general anesthesia. Thereafter, the patient temporarily suffered from respiratory failure, and controlled respiration by a respirator was needed. Since the amount of discharge from the mediastinal and thoracic drains gradually decreased, and clinical symptoms disappeared, the drain tubes were removed. During the clinical course, laryngoscopy, bronchoscopy, esophago-gastro-endoscopic examination and esophagography were performed. Esophagoscopy revealed a diverticulum, and esophagography showed a fistula from the esophageal diverticulum to mediastinum. From these examination results, a diagnosis of mediastinitis caused by rupture of esophageal diverticulum was established.

Adult↗
PubMed1990

[Septic pulmonary emboli caused by parenteral nutrition catheter infection].

A case of septic pulmonary emboli due to parenteral nutrition catheter infection was reported. Characteristic radiologic features were recognized. A 50-year-old man, who was receiving parenteral nutrition after total gastrectomy, consulted our department with complaints of fever and general malaise. A chest radiograph showed scattered ill-defined small peripheral nodules, which were not present before parenteral nutrition, and these nodules were quickly formed cavities + in 2nd day. He was suffering from high fever, hemo-sputum and dyspnea after removal of the parenteral nutrition catheter. Pseudomonas aeruginosa was isolated from the tip of parenteral nutrition catheter and sputum cultures. Septic pulmonary emboli were diagnosed and antibiotic therapy was performed. Bacterial endocarditis and septic thrombophlebitis were ruled out. The multiple cavity nodules extended to involve the peripheral areas of the lung and invasive shadows appeared on the chest radiograph in 8th day. Then, the invasive shadows disappeared and the walls of the cavitary lesions became thinner. After 2 months, all cavitary lesions disappeared with only linear shadows remaining.

Catheterization, Central Venous↗
PubMed1990

[A case of pulmonary arteriovenous fistula treated by subsegmentectomy with CUSA].

A 35-year-old female who had no symptom was admitted to our hospital because of an abnormal shadow in the middle area of the right lung in a chest X-ray film. The chest tomography, CT and the angiography revealed a pulmonary arteriovenous fistula. It located in the right upper lobe, and was successfully resected by subsegmentectomy of S3b using CUSA. The results indicated that the CUSA was useful in the surgical treatment of the pulmonary arteriovenous fistula which had many vascular anastomoses.

Adult↗
PubMed1989

Selective local action of angiotensin II on dopaminergic neurons in the rat hypothalamus in vivo.

Microdialysis was used to investigate whether angiotensin II modulates the basal and K+-induced release of endogenous noradrenaline, dopamine and their metabolites 3,4-dihydroxyphenylglycol (DOPEG) and 3,4-dihydroxyphenylacetic acid (DOPAC) from the anterior hypothalamus of the anaesthetized rat. The release of the amines was stimulated twice (ST1 and ST2) with either 50 mmol/l or 100 mmol/l K+. The release of each amine induced by K+ was reproducible and concentration-dependent. Angiotensin II when present in the perfusion fluid after ST1 at a concentration of 0.1 and 10 mumol/l (chosen after in vitro experiments had shown that the recovery of the peptide across the dialysis membrane was only 3.6%), had no significant effect on amine release. However, 10 mumol/l angiotensin II induced an immediate, significant increase in basal DOPAC outflow which reached a maximum of 89% in the 100 mmol/l K+ and 53% in the 50 mmol/l K+ experiments. No such effect was observed with DOPEG outflow. In a separate experimental series, addition of angiotensin II without a preceding K+ stimulation period did not significantly affect the outflow of the amines and metabolites. The results suggest that angiotensin II can selectively influence dopamine metabolism in the anterior hypothalamus in vivo but does not act locally to acutely facilitate the release of endogenous catecholamines from this brain area.

3,4-Dihydroxyphenylacetic Acid↗
PubMed1989

Lipomas of the peripheral lung--a case report and review of the literature.

Bronchial lipomas are uncommon benign neoplasms of the lung and the number of these tumours is only 109 cases in the international literature (108 cases reported in English and one in German) up to date. Moreover, most of the tumours occur in the proximal portions of lobar or segmental bronchi: the references in the literature to peripheral lipoma of the lung make up only 6 cases. Peripheral lipomas of the lung are thought to originate from fatty tissue in the wall of peripheral bronchi. We present a further case of peripheral lipoma and analyze the reported 7 cases.

Adult↗
PubMed1989

Interaction of hydroxyapatite with sodium chondroitin sulfate and calcium chondroitin sulfate in an aqueous phase.

The suspension pH at a given concentration of hydroxyapatite (HAP) decreased with the concentration of calcium chondroitin-6-sulfate (CaChs), whereas it increased with the concentration of sodium chondroitin-6-sulfate (Na2Chs). The former effect is due to the increase in the concentration of H+ by ion exchange between H+ on the surface of HAP and Ca2+ of CaChs, and the latter is due to the protonation of phosphate ion (Pi) released from the surface of HAP. The absorbed amount of chondroitin-6-sulfate anion (Chs) by HAP was higher with CaChs than with Na2Chs over the concentration range examined. The equilibrium concentration of Pi decreased with increasing concentration of added CaChs because the concentration of free Ca2+, which dissociates from CaChs, regulates the free concentration of Pi through the restriction of the solubility product of HAP (Ksp). In contrast, that in the presence of Na2Chs increased with increasing concentration of added Na2Chs owing to the anion exchange between Chs and Pi of the HAP surface. The total concentration of Ca2+, which was released from HAP into the solution phase, increased after passing through a minimum with increasing concentration of added Na2Chs. That is, the concentration of Ca2+ free from Chs decreased with an increase in the concentration of released Pi owing to the restriction of the solubility product, whereas that of Ca2+ bound by Chs increased with increasing concentration of added Na2Chs through the ion exchange of Na+ with Ca2+. It was confirmed by the dialysis method that the value of Ksp was almost constant around 10, although HAP dissolves incongruently in the presence of Na2Chs.

Chemical Phenomena↗
PubMed1989

Corticotropin-releasing hormone in the human hypothalamus. Free-floating immunostaining method.

We have clearly demonstrated corticotropin-releasing hormone (CRH) immunoreactive cell bodies and nerve fibers in the human hypothalamus by immunocytochemistry using free-floating sections instead of paraffin-embedded sections. Human hypothalami were obtained at autopsy, fixed and cryostat-sectioned at 40 microns. Free-floating sections were immunostained with antibody to CRH using the Vector ABC system. Most of CRH immunoreactive nerve fibers from the paraventricular nucleus pass under the fornix, while some CRH immunoreactive nerve fibers pass beyond the fornix and some through the fornix. Then the CRH immunoreactive nerve fibers run downward, medially to the supraoptic nucleus and toward the pituitary stalk. This method of immunocytochemistry is a very sensitive and suitable means for immunocytochemical studies of neuropeptides in the human brain.

Aged↗
PubMed1989

Calcitonin gene-related peptide in the human hypothalamus.

Calcitonin gene-related peptide (CGRP)-like immunoreactivity (LI) in the human hypothalamus was investigated by radioimmunoassay and by immunocytochemistry. CGRP-LI was detected from two hypothalami obtained at autopsy (2.1 and 7.0 ng/g wet tissue) by radioimmunoassay. Reverse phase high performance liquid chromatography revealed that most of the CGRP-LI in the human hypothalamus was eluted in an identical position with synthetic human CGRP. For immunocytochemistry, human hypothalami obtained at autopsy were fixed and cryostat-sectioned at 40 microns. Free floating sections were immunostained with antibody to CGRP. CGRP-immunoreactive cell bodies were found in the supraoptic nucleus, paraventricular nucleus and infundibular nucleus. These findings indicate that CGRP exists in the cell bodies of the supraoptic nucleus, paraventricular nucleus and infundibular nucleus in the human hypothalamus and CGRP may play some roles in the endocrine and other functions of the human hypothalamus.

Aged↗
PubMed1989

Neuropeptide Y and blood pressure in haemodialysis patients.

To investigate the relationship between plasma neuropeptide Y (NPY) concentrations and blood pressure in haemodialysis (HD), we measured plasma immunoreactive neuropeptide Y (IR-NPY) concentrations and blood pressure before and after HD in 71 patients undergoing maintenance HD. Plasma IR-NPY concentrations were measured by radioimmunoassay after extraction with Sep-Pak C18 cartridges. We corrected the plasma IR-NPY values after HD by reference to the ratio of the plasma total protein levels before HD to the levels after HD, in order to exclude the influence of the haemoconcentration caused by HD. Plasma IR-NPY concentrations before and after HD in 71 patients undergoing maintenance HD were 413 +/- 94 pg/ml and 340 +/- 90 pg/ml (mean +/- SD), respectively. Plasma IR-NPY concentrations before HD in 28 hypertensive patients with HD (398 +/- 91 pg/ml) were not significantly different from those in 40 normotensive (427 +/- 98 pg/ml) and 3 hypotensive (372 +/- 21 pg/ml) patients with HD (P greater than 0.1). Plasma IR-NPY concentrations after HD in 9 patients whose systolic blood pressure fell more than 30 mmHg during HD (409 +/- 52 pg/ml) were significantly higher than those in the other patients (P less than 0.025). These findings suggest that the release of NPY is increased when the blood pressure falls during HD in patients undergoing maintenance HD.

Blood Pressure↗
PubMed1989

Neuropeptide Y- and somatostatin-like immunoreactivities in ganglioneuroma, ganglioneuroblastoma and neuroblastoma.

Neuropeptide Y (NPY)- and somatostatin (SS)-like immunoreactivities (LI) were investigated in tumor tissues of one ganglioneuroma (GN), 3 ganglioneuroblastomas (GNB) and one neuroblastoma (NB) by radioimmunoassay. NPY-LI was detected from all 5 tumor tissues (16.4-1247 pmol/g wet tissue). Sephadex G-50 column chromatography and reverse phase high performance liquid chromatography (HPLC) revealed that most of the NPY-LI in tumor extracts was eluted in an identical position to synthetic human NPY except one GNB (case 2). In this case, most of the NPY-LI was eluted in a higher molecular weight region than synthetic human NPY in Sephadex G-50 column chromatography and in a more hydrophobic position in HPLC. SS-LI was detected from 4 tumor extracts except one GNB (case 2) (21.3-787 pmol/g wet tissue). Sephadex G-25 column chromatography and reverse phase HPLC revealed that SS-LI in tumor extracts was eluted just after the void volume and then in the same positions as SS-28 and SS-14. These results suggest that NPY, SS-14 and SS-28 exist in tumor tissues of GN, GNB and NB, and most of the NPY-LI in one GNB was a higher molecular and more hydrophobic form of NPY-LI.

Chromatography, Gel↗
PubMed1989

[An immunoradiometric assay of the serum TPA from patients with primary lung cancer and a comparison with the conventional double antibody method].

The serum level of tissue polypeptide antigen (TPA) has been measured by a new immunoradiometric assay (IRMA) method that has been recently developed using a specific antibody, and compared with the results obtained by the conventional double antibody method, using a polyclonal antibody. Both methods gave essentially the same results, i.e. the serum TPA level in patients with primary lung cancer was higher when compared with non-malignant pulmonary diseases and healthy individuals (p less than 0.01). However the positive rate and average values of TPA with patients of non-malignant diseases were found to be lower by the new IRMA method than by the conventional method. This may be due to the improvement in specificity and accuracy of this newer method of assay, as they also statistically decrease within the cut off level (110 U/L) estimated in non-malignant diseases and healthy individuals. Therefore, it has been concluded that the IRMA method is more suitable than the conventional method for diagnosis of primary lung cancer.

Adenocarcinoma↗