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Biomedical subjects

H Itoh

Publications and source records attributed to H Itoh.

At least 1,009 records · Page 56Linked to original sources
PubMed1992

Effects of intravesically administered verapamil HC1 (calcium entry blocker) on the bladder function in unanesthetized rats.

The effects of intravesically administered verapamil HCl (calcium entry blocker) on the bladder function were investigated using an experimental model for unanesthetized rats. Intravesical verapamil HCl caused a marked suppression of maximum intravesical pressure accompanied by an increase of residual urine in a dose-dependent manner. The effect almost disappeared 90 min after the elimination of verapamil HCl. It is tentatively suggested that the intravesical instillation of verapamil HCl could be a potent therapy for disorders of bladder function, such as uninhibited contraction.

Administration, Intravesical↗
PubMed1992

Computer-assisted three-dimensional volumetry of the human pulmonary acini.

Computer-aided three-dimensional (3-D) volumetry of human pulmonary acini was undertaken using the left upper lobe of a 51-year-old female operated for small lung cancer. A normal part of this lobe, fixed by intrabronchial infusion with a mixture of polyethylene glycol and formalin, was subjected to serial sectioning, using a special slicer, into 48 serial slices of 0.5 mm in thickness. A soft x-ray radiograph was prepared from each slice at x 12, and the contours of airways and acinar boundaries contained in it were input by digitization into a microcomputer for 3-D reconstruction and volumetry. The estimated volumes of 130 acini were unexpectedly uniform, showing a normal type distribution with a mean of 172.7 +/- 37.9 mm3. No significant correlation proved to exist between the volume of acini and the number of branching generation of the terminal bronchioles (TBs) they received. Furthermore, there was no significant difference in volume among the acini facing the costal surface, those facing the mediastinal surface and those not facing any pleural surface. However, the generation number of TBs was shown to differ significantly with the location of acini. These results suggest that the tree of conductive airways is designed so as to meet the requirement of constant acinar volume.

Adenocarcinoma↗
PubMed1992

A case of primary intrahepatic sclerosing cholangitis (PISC) complicated with atypical biliary epithelial proliferation.

A 70-yr-old woman was admitted to our hospital with duodenal ulcer and anemia. The result of liver function test was abnormal and showed persistent elevated alkaline phosphatase levels. Thus, after recovery from duodenal ulcer, endoscopic retrograde cholangiopancreatography (ERCP) was performed; the characteristic "beaded" appearance with band-like strictures and saccular outpouchings affecting the intrahepatic biliary system were found. The diagnosis of primary intrahepatic sclerosing cholangitis (PISC) was made on the basis of the generally accepted diagnostic criteria of primary sclerosing cholangitis (PSC). However, the histological finding from a liver biopsy specimen revealed highly atypical epithelial proliferation of bile ducts. This case of PISC complicated with atypical biliary glandular changes is described, and the distinction between PISC and carcinoma of the bile duct is discussed.

Aged↗
PubMed1992

Sibling cases of primary biliary cirrhosis associated with polymyositis, vasculitis and Hashimoto's thyroiditis.

Primary biliary cirrhosis (PBC) was diagnosed in two siblings, a 42-year-old male and his 49-year-old sister. Furthermore, they were complicated with three types of autoimmune diseases: polymyositis, Hashimoto's thyroiditis and vasculitis of the right axillary artery. Although PBC is often associated with other autoimmune diseases, reports of the association with polymyositis and vasculitis syndrome are rare. Familial clustering of PBC with autoimmune diseases is also rare.

Adult↗
PubMed1992

Methyldopa-induced colitis in a patient with membranoproliferative glomerulonephritis.

A 76-year-old man with membranoproliferative glomerulonephritis complicated by methyldopa-induced colitis is reported. Eight months after administration of methyldopa, mucous bloody stool was noted. A barium enema examination showed disappearance of haustra and a spastic rectosigmoid with pseudo-polyposis. Biopsy specimens obtained from the sigmoid mucosa revealed interstitial edema and small inflammatory cells. After cessation of methyldopa treatment, the sigmoid findings, blood pressure, and proteinuria were improved, suggesting that methyldopa not only induced the acute colitis but also worsened the nephrotic syndrome in this patient.

Acute Disease↗
PubMed1992

Sweet's syndrome associated with subacute necrotizing lymphadenitis.

A 34-year-old man with Sweet's syndrome associated with subacute necrotizing lymphadenitis is reported. Histological examination of an erythematous, painful, cutaneous plaque revealed a dermal interstitial neutrophilic infiltrate. A biopsy specimen obtained from an inguinal lymph node showed granulomatous formation, consisting of histiocytes, with central necrosis in the paracortex and macrophages in the sinus. Although the causes of the two diseases remain obscure, this appears to be the first report of Sweet's syndrome associated with subacute necrotizing lymphadenitis.

Adult↗
PubMed1992

Effects of acute hypoxia on ventilatory response at the onset of cycle exercise in man.

In order to examine whether or not there are initial changes in ventilation at the start of bicycle exercise having work loads of differing intensities are affected with regard to normoxia and to hypoxia accompanying hypocapnia, six healthy male subjects performed submaximal exercise of 30 and 120 W at 60 rpm under normoxic (FIO2 = 0.21) and hypoxic (FIO2 = 0.11) conditions. Resting ventilation was significantly higher in hypoxia than in normoxia. However, no statistically significant differences in the initial change in ventilation at the start of exercise (delta VI assessed breath-by-breath) were found between eucapnic normoxia and hypocapnic hypoxia in both 30 and 120 W exercise. Moreover, blood lactate after exercise did not increase in any conditions as compared with rest. These observations suggest that the neurogenic ventilatory response immediately after submaximal exercise at a work load below the subject's anaerobic threshold is independent from PO2.

Adult↗
PubMed1992

The effects of leg-cooling on blood lactate disappearance following supramaximal exercise.

In order to clarify whether leg-cooling after supramaximal treadmill exercise will change lactate disappearance rate from venous blood, blood lactate, calf blood flow, and skin temperature were determined in cold application and non-cold application recovery. In the cooling experiments, both legs were cooled with ice packs for 23 min during recovery. The skin temperature was significantly lower in the cold application as compared with the non-cold application. However, no significant difference was found in the blood lactate and/or calf blood flow between cold and non-cold conditions. In addition, there was no significant difference in the slope of regression line (blood lactate/blood flow) between cold and non-cold applications. These results suggest that no significant difference in the blood lactate between cold and non-cold applications could be explained by the lack of difference in the blood flow between cold and non-cold applications.

Adult↗
PubMed1992

Calcium suppresses central angiotensin II pressor response less in SHR.

To determine whether calcium alters central cardiovascular regulation, cardiovascular responses to intracerebroventricular (ICV) injection of calcium were recorded in conscious Wistar rats. Calcium injection consistently produced dose-dependent decreases in mean parterial pressure and heart rate. Pretreatment with a calcium channel blocker, diltiazem, attenuated cardiovascular responses to calcium. Decreases in plasma norepinephrine indicated the contribution of sympatho-inhibition to vasodepression by calcium. Preceding calcium injection reduced pressor responses to ICV-injected angiotensin II. These findings suggest that there is a pharmacological interaction between calcium and angiotensin II in the central nervous system. In spontaneously hypertensive rats (SHR), cardiovascular responses to calcium was larger than Wistar Kyoto rats (WKY). By contrast, calcium reduced pressor responses to angiotensin II only in WKY but not in SHR. Because the central interaction between calcium and angiotensin II has been different in SHR, our results imply that this difference may be related to the maintenance of high blood pressure in SHR.

Angiotensin II↗
PubMed1992

[CT diagnosis of diffuse lung disease].

The first HRCT of the lung was obtained in 1979 in Japan. Since then, CT-pathologic correlations have been performed in the major diffuse lung diseases. For this purpose, lung specimens were fixed in the inflated condition, which enables precise stereomicroscopic observations to be performed on sliced lung specimens. The first successful correlation was performed in diffuse panbronchiolitis (DPB), where nodular densities in HRCT were proven to correspond to chronic inflammation in the respiratory bronchioles and their neighboring structures. However, further investigation of the correlations are required in diffuse lung diseases showing ground glass-like densities in CT, since this finding is nonspecific and may occur in both airspace and interstitial lung disease.

Bronchiolitis↗
PubMed1992

Poly (lactic/glycolic acid) microspheres containing antigen as a novel and potential agent of immunotherapy for allergic disorders.

In order to establish a safer and simpler antigen administration method in immunotherapy, we prepared biodegradable microspheres containing antigen and evaluated its safety and efficacy using guinea pigs. Poly (lactic/glycolic acid); (LGA) microspheres containing ovalbumin (OA) were fabricated by solvent evaporation. Over 70% of the OA was released from the microspheres within 3 days, and release was completed within 14 days in vivo. The local tissue reactions to the OA-LGA microspheres were apparently weaker than those to OA-alum. Repeated injections of high dose OA-LGA microspheres to OA-sensitized guinea pigs (high-LGA group) for 8 weeks at intervals of 2 weeks elicited an excellent therapeutic effect, i.e. a significant increase in the threshold value of antigen inhalation test, with a significant increase in IgG2 blocking antibody. The therapeutic efficacy of the high-LGA group was comparable to the conventional immunotherapy model (conventional group) and was superior to the antigen-alum model (alum group). We concluded that administration of antigen-LGA microspheres could become a new immunotherapeutic method for allergic disorders, being safer and requiring a lower frequency of antigen injections than the conventional method.

Animals↗
PubMed1992

The natriuretic peptide system in the brain: implications in the central control of cardiovascular and neuroendocrine functions.

The natriuretic peptide system consists of three endogenous ligands, i.e., atrial natriuretic peptide (ANP), brain natriuretic peptide (BNP), and C-type natriuretic peptide (CNP), and at least three subtypes of receptors. All of the peptides and receptors exist in the central nervous system (CNS). ANPs in the brain are N-terminally truncated forms: ANP (4-28) and ANP (5-28). The primary structure of BNP varies considerably among species, whereas that of CNP is highly conserved. ANP, BNP, and CNP are distributed in discrete brain regions, although the distribution varies in different species. Few immunohistochemical studies have so far been performed on BNP and CNP. There are three subtypes of receptors: ANP-A and ANP-B, which are bioactive, and the C receptor, which does not seem to be directly related to bioactivity. In the rat, the major subtype of ANP receptor in the CNS is the ANP-B receptor, based on the results of Northern blotting. Since the ligand for ANP-B receptor is CNP, the CNP-ANP-B receptor system may be most important, at least in rat brain. It is still unknown whether or not a specific receptor for BNP exists in central or peripheral tissues. Further studies should clarify the exact localization of ANP, BNP, and CNP and the three receptor subtypes in the CNS. Although natriuretic peptides and their receptors are distributed widely in the CNS, the AV3V regions, basal medial hypothalamus, brainstem, and circumventricular organs are the most prominent sites. This suggests an important physiological role of the natriuretic peptide system in the central control of cardiovascular homeostasis. The natriuretic peptide system seems to be involved in the regulation of water and salt intake, blood pressure, and secretion of vasopressin in the direction of reducing body fluid and lowering blood pressure. Such actions of natriuretic peptides are antagonistic to the central actions of angiotensin II (AII). In fact, the distribution of ANP and AII and their receptors in the CNS overlaps considerably. It is highly likely, therefore, that the central natriuretic peptide system and the renin-angiotensin system play important roles in the central control of cardiovascular and body fluid homeostasis in opposite directions. The natriuretic peptide system may also be involved in neuroendocrine control and some other CNS functions, although the physiological significance of these actions is less clear at the present time. It is now clear that there is considerable plasticity in the regulation of natriuretic peptides and their receptors.(ABSTRACT TRUNCATED AT 400 WORDS)

Amino Acid Sequence↗
PubMed1992

High performance liquid chromatography of nucleic acids and the related compounds on a fluorinated silica gel column.

Separations of nucleic acids and the related compounds were investigated by HPLC on a new fluorinated bonded silica gel column. Polyadenylate (Poly (A)) enzymatic partial hydrolysate sample and the mixture of various polynucleotide samples were sufficiently separated by the reversed-phase mode using a gradient elution with aqueous ammonium acetate/acetonitrile system. Mixed-mode separation on the fluorinated bonded phase coated with a tert-alkylammonium salt was also examined for the separation of the various polynucleotides including tRNAs.

Chromatography, High Pressure Liquid↗
PubMed1992

Manidipine inhibits the progression of hypertension and atherosclerosis in endothelium-injured and cholesterol-fed Goldblatt 2K1C rats.

In the present study, arteriosclerotic change of the aorta was induced in rats. The effects of manidipine hydrochloride on the resulting hypertension and arteriosclerotic change were studied. In endothelium-injured cholesterol-fed Goldblatt 2K1C rats, moderate elevation of blood pressure was noted at 3, 4, and 5 weeks. Laboratory studies performed at the end of 6 weeks also showed hypercholesterolemia, accompanied by a reduction of triglycerides and HDL cholesterol. Regular doses of manidipine (200 or 500 mg/kg) resulted in a dose dependent inhibition of the blood pressure elevation and a reduction of HDL cholesterol, but had no effect on cholesterol or triglyceride levels. Morphological studies in endothelium-injured rats afflicted with hypercholesterolemia and hypertension, showed medial thickening and intimal hyperplasia. Hyperplasia of the intima was a result of excessive proliferation of the smooth muscle cells. These cells showed an unusually large number of fat droplets and were considered indicative of atheromatous plaque formation. In rats treated with manidipine, hyperplasia of the media was completely suppressed while hyperplasia of the intima was reduced by a minimum of 50%. This study demonstrated that hypercholesterolemia and hypertension produced arteriosclerotic change in endothelium-injured rats, which was inhibited by manidipine. It is not known whether antiarteriosclerotic action was involved in the antihypertensive effect of manidipine.

Animals↗
PubMed1992

Effect of manidipine on cardiac hypertrophy and coronary circulation in DOCA/salt hypertensive rats.

The effect of manidipine on cardiac hypertrophy, coronary circulation, left ventricular weight and maximal coronary flow in hypertension was measured in DOCA/salt treated systolic hypertensive rats with and without manidipine treatment. Normotensive rats were used as controls. After feeding with 0.05% manidipine-containing food, blood pressure was reduced only in DOCA/salt hypertensive rats, but not in control rats. After 3 weeks of treatment, sodium excretion was significantly increased in DOCA/salt-treated rats with or without manidipine treatment. Hearts were removed and perfused with modified Krebs-Henseleit solution with adenosine (5 x 10(-5) M) in a Langendorff apparatus. Maximal coronary flow (MCF) was significantly decreased only in DOCA/salt hypertensive rats without treatment, while manidipine treatment restored MCF. Left ventricular weight/body weight was also markedly greater in DOCA/salt-treated rats not given manidipine. Left ventricular weight in DOCA/salt-treated rats given manidipine was significantly reduced compared with DOCA/salt hypertensive rats without treatment, although it was heavier than in the control animals. Morphological examination showed that the increased wall/lumen ratio in DOCA/salt hypertensive rats was reduced by manidipine treatment. These findings suggest that treatment with manidipine in DOCA/salt hypertensive rats lowered high blood pressure and improved impaired coronary circulation with a reduction in left ventricular and vascular hypertrophy.

Aldosterone↗