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K Hori

Publications and source records attributed to K Hori.

At least 109 records · Page 6Linked to original sources
PubMed1999

[A case of pulmonary plasma cell granuloma with a cavity].

Plasma cell granuloma of the lung is an uncommon and non-malignant neoplasm that may present difficulties in both diagnosis and management. We report a 52-year-old male who was admitted to our hospital due to fever and an abnormal shadow on chest roentgenography. Chest computed tomography revealed a tumor shadow with a cavity in the left upper lobe. However, neither bronchofiberscopy nor serum examinations suggested a diagnosis. Video-assisted thoracoscopic surgery (VATS) was performed and postoperative pathological examination of the resected specimen showed plasma cell granuloma. The postoperative course was uneventful. No recurrence was observed 10 months after the operation. As plasma cell granuloma of the lung is histologically benign, surgery should be performed to preserve the maximal residual lung with no lesion. VATS is the method of choice for treatment of pulmonary plasma cell granuloma.

Humans↗
PubMed1998

Dopamine and acetylcholine elevation on lever-press acquisition in rat prefrontal cortex.

To determine whether the rat medial prefrontal cortex (PFC) is involved in acquiring operant learning, we observed changes in extracellular concentration of dopamine (DA) and acetylcholine (ACh) in the rat medial PFC during lever-press acquisition (acquisition group) or retrieval (retention group) using in vivo microdialysis. We found that DA or ACh elevation related to acquisition occurred. DA elevation was observed in the acquisition group only. These results indicate that the medical PFC is related to acquisition, and suggest that interaction between DA and ACh may be involved in learning acquisition.

Acetylcholine↗
PubMed1998

Inactivation of bacterial respiratory chain enzymes by singlet oxygen.

To distinguish the bactericidal action of singlet oxygen (1O2) from hypohalous acids, wild-type and lycopene transformant E. coli strains were exposed to each of the oxidants and then bacterial viability was investigated. 1O2 was generated by chemical and enzymatic systems at pH 4.5. ExpoSure of wild-type E. coli to 1O2 caused a significant loss of E. coli viability due to inactivation of membrane respiratory chain enzymes by 1O2. This action of 1O2 could be attenuated by lycopene in the bacterial cell membrane. In the lycopene transformant strain of E. coli, inactivation of NADH oxidase and succinate oxidase by hypohalous acids were significantly suppressed, but E. coli viability was unaffected. Based on these findings, we suggest that phagocytic leukocytes produce 1O2 as a major bactericidal oxidant in the phagosome.

Bromides↗
PubMed1998

Cloning of the Xenopus laevis aldolase C gene and analysis of its promoter function in developing Xenopus embryos and A6 cells.

A Xenopus aldolase C gene (XAClambda3-1), much longer (9.6 kb) than human and rat genes (3.7-3.6 kb), was isolated and characterized, and expression studies were performed using Xenopus embryos and A6 cells, a kidney cell line constitutively expressing aldolase C gene. The Xenopus gene contained nine exons, and in its proximal 5'-upstream region a GC box and a 16 bp long aldolase C-specific element (ACSE), and in addition, a CCAAT box and a TATA-like element, both missing in mammalian genes. The lacZ gene connected to the 5'-upstream region (1.6 kb) of the aldolase gene containing many potentially regulative sequence elements was expressed in embryos temporally and spatially like the endogenous aldolase C gene. Deletion experiments using embryos and A6 cells suggested that this 5'-upstream DNA contained in its distal part a region which negatively affected on its expression in embryos, but not in A6 cells. The proximal-most region contained a basal promoter (68 bp) essential for expression in both embryos and A6 cells. Deletion experiments using A6 cells failed to detect such regulative regions within the first intron (spanning ca. 4 kb). Analyses with mutated promoters in A6 cells revealed that the GC box was the crucial element in the basal promoter, although the TATA-like element appeared to have a slightly stimulative effect on the GC box functioning. Gel retardation and foot-printing assays revealed the occurrence in A6 cells of a nuclear factor(s) that binds specifically to the GC box. Since Xenopus aldolase C gene has several unique structural features, we expect that it will provide an interesting material for studying the evolution and developmental control of the aldolase C gene.

Amino Acid Sequence↗
PubMed1998

Chronic cerebral hypoperfusion disrupts discriminative behavior in acquired-learning rats.

We describe an 'acquired-learning' rat model that was used to investigate the effects of chronic cerebral hypoperfusion on the maintenance of previously acquired discriminative behavior using the discriminating learning task. Male Wistar rats, aged 11 weeks, were trained to discriminate between lamp-on and lamp-off states under an operant-type learning procedure. After 30 sessions, we selected 'acquired-learning' rats with an average discrimination ratio higher than 75% recorded during the last three sessions. Chronic hypoperfusion was then induced by permanent ligation of both common carotid arteries under pentobarbital anesthesia. The rats were tested after surgery over a period of 12 weeks and brain tissue was analyzed for muscarinic acetylcholine receptor (mACh-R) binding. Cerebral hypoperfusion resulted in a significant reduction in the discrimination ratio throughout the observation period, compared with sham-operated rats. However, chronic hypoperfusion would not affect on motor function. The maximum number of mACh-R examined 12 weeks after the operation was significantly reduced in the frontal cortex and hippocampus in the hypoperfusion group. Impaired discrimination learning was associated with a reduction in mACh-R. Our findings suggest that chronic cerebral hypoperfusion in acquired-learning rats is a useful model for investigating the pathophysiology of dementia and that cortical and/or hippocampal cholinergic systems contributes to learning impairment, at least, in our learning task.

Analysis of Variance↗
PubMed1998

Noradrenaline release in the rat subfornical organ area to blood pressure changes.

To verify whether noradrenergic inputs to the subfornical organ (SFO) are involved in the control system of arterial pressure, we investigated the effects of blood pressure changes on noradrealine (NA) release in the SFO and its surrounding sites using microdialysis techniques in rats. Hemorrhage (5 or 10 ml/kg) significantly increased the NA concentration in the region of the SFO, but did not cause significant changes in the sites away from the SFO. An elevation in arterial pressure following intravenous administration of the alpha-agonist metaraminol slightly decreased the NA level in the region of the SFO. These results imply that the noradrenergic neural inputs to the SFO area may be involved in the control of cardiovascular function.

Adrenergic alpha-Agonists↗
PubMed1998

Role of isozyme group-specific sequence 4 in the isozyme-specific properties of human aldolase C.

To assess which regions of the aldolase C molecule are required for exhibiting isozyme-specific kinetic properties, we have constructed nine chimeric enzymes of human aldolases A and C. Kinetic studies of these chimeric enzymes revealed that aldolase C absolutely required its own isozyme group-specific sequences (IGS), particularly IGS-4, for exhibiting the characteristics of aldolase C which differ significantly from those of isozymes A and B (Kusakabe T, Motoki K, Hori K. Human aldolase C: characterization of the recombinant enzyme expressed in Escherichia coli. J Biochem (Tokyo) 1994;115:1172-7). Whereas human aldolases A and B required their own isozyme group-specific sequences-1 and -4 (IGS-1 and -4) as the main determinants of isozyme-specific kinetic properties (Motoki K, Kitajima Y, Hori K. Isozyme-specific modules on human aldolase A molecule. J Biol Chem 1993;268:1677-83; Kusakabe T, Motoki K, Sugimoto Y, Takasaki Y, Hori K. Human aldolase B: liver-specific properties of the isoenzyme depend on type B isozyme group-specific sequence. Prot. Eng. 1994;7:1387-93), the present studies indicate that the IGS-1 is principally substitutable between aldolases A and C. The kinetic data also suggests that the connector-2 (amino acid residues 243-306) may modulate the interaction of IGS units with the alpha/beta barrel of the aldolase molecule.

Amino Acid Sequence↗
PubMed1998

Responses of raphe nucleus projecting subfornical organ neurons to angiotensin II in rats.

The subfornical organ (SFO) is an important central site of action of circulating angiotensin II (ANG II). Although neuroanatomical tracing studies have identified the efferent pathways from the SFO to the midbrain raphe nucleus (RN), the functional role of the pathways is unknown. The present study was carried out to examine the responses of SFO neurons projecting to the dorsal RN (DRN) to microiontophoretic application or intracarotid injection of ANG II in male rats under urethane anesthesia. Twenty-three neurons in the SFO were antidromically identified by electrical stimulation of the midbrain DRN. Of these identified units, 13 were excited by ANG II applied iontophoretically, while 10 were unresponsive. ANG II-induced excitation was prevented by the ANG II antagonist saralasin (Sar) applied iontophoretically. The activity of seven out of 10 units that displayed this excitation to iontophoretically applied ANG II was also enhanced by intracarotid injection of ANG II. These results suggest that SFO neurons projecting to the DRN may monitor the circulating level of ANG II and carry the information to the DRN.

Angiotensin II↗
PubMed1998

Effect of serotonin on ouabain-sensitive, K+-dependent, p-nitrophenylphosphatase activity in strial marginal cells of normal and reserpinized guinea pigs.

Na+,K+-ATPase activity is abundant on the basolateral infoldings of the strial marginal cells and contributes to the maintenance of the characteristic electrolyte composition of the endolymph. However, the stria vascularis of the cochlea is known not to be innervated. In order to clarify its humoral regulation by serotonin, the K+-p-nitrophenylphosphatase activity of strial marginal cells was investigated with a cerium-based method in normal guinea pigs and in guinea pigs treated with reserpine, 5-hydroxytryptamine or reserpine plus 5-hydroxytryptamine. K+-p-nitrophenylphosphatase activity was almost completely depressed 3-20 days after reserpine administration. Ten days after reserpinization, followed by repeated 5-hydroxytryptamine treatment, the enzyme activity was detectable. These results suggest that 5-hydroxytryptamine increases the phosphatase activity. Thus, the function of the stria vascularis in producing cochlear endolymph may be regulated by 5-hydroxytryptamine.

4-Nitrophenylphosphatase↗
PubMed1998

Endothelin receptors and angiotensin II receptors in tumor tissue.

In cancer chemotherapy, selective enhancement of drug delivery to tumor tissue is essentially important for increase of chemotherapeutic effects. An attenuated vasoconstrictive response to angiotensin II (Ang II) in tumors and a marked increase in tumor blood flow were observed compared with normal tissues during systemic hypertension induced by Ang II infusion. The phenomenon was absent when hypertension was provoked by endothelin-1 (ET-1). We assessed this response to characterize ET receptor and Ang II receptor density and affinity in normal and tumor tissues. The tumor cell line LY80 was transplanted to the skin in nude rats. Four weeks later the rats were sacrificed. [125I] ET-1 and [125I Sar1, Ile8]-Ang II were used to map the receptors for ET and Ang II in rat tissues using computerized in vitro autoradiography. A moderately high density of ET receptors, (ETB > ETA) was found in tumors. The Ang II receptors were markedly reduced in tumor tissues without changes in the affinity. These results suggest that the decrease in Ang II receptors but not ET receptors in tumors may explain the hemodynamic effect of Ang II-induced hypertension and ET-induced hypertension on tumor blood flow.

Angiotensin II↗
PubMed1998

Endovascular papillary angioendothelioma (Dabska tumor) in an elderly woman.

A patient with endovascular papillary angioendothelioma with a low grade of malignancy showing papillary proliferation of endothelioid cells is presented. The patient, an 83-year-old woman, underwent resection of a tumor of the neck. At operation a 9 x 7 cm cystic tumor containing yellow transparent liquid with clots was found in the subcutaneous tissue. Histological studies showed endothelioid cells with spindle-shaped nuclei proliferated in layers around the fibrovascular cores, which showed the characteristic appearance of papillary proliferation. These cells were immunohistochemically positive for CD31, CD34 and factor VIII-related antigen. Based on these observations, the tumor was considered to be an endovascular papillary angioendothelioma (Dabska tumor). Dabska tumor is a vascular tumor with a low grade of malignancy and usually occurs in infants and young children. About 13 cases of Dabska tumor have been reported. The occurrence of a Dabska tumor in an aged patient is considered to be rare.

Aged↗
PubMed1998

Structures of new acylated oleanene-type triterpene oligoglycosides, theasaponins E1 and E2, from the seeds of tea plant, Camellia sinensis (L.) O. Kuntze.

Two new acylated oleanene-type triterpene oligoglycosides, theasaponins E1 and E2, were isolated from the seeds of tea plant [Camellia sinensis (L.) O. Kuntze]. The structures of theasaponins E1 and E2 were elucidated on the basis of chemical and physicochemical evidence to be expressed as 21-O-angeloyl-22-O-acetyltheasapogenol E 3-O-[beta-D-galactopyranosyl(1-->2])[beta-D-xylopyranosyl(1-->2)-alpha-L - arabinopyranosyl (1-->3)]-beta-D-glucopyranosiduronic acid and 21-O-angeloyl-28-O-acetyltheasapogenol E 3-O-[beta-D-galactopyranosyl(1-->2)][beta-D-xylopyranosyl (1-->2)-alpha-L-arabinopyranosyl (1-->3)-beta-D-glucopyranosiduronic acid, respectively. Theasaponin E1 was found to show antisweet activity.

Acylation↗
PubMed1998

[On the constituents of the root of fukuchiyama-jio, the hybrid of Rehmannia glutinosa var. purpurea and R. glutinosa forma hueichingensis].

In order to characterize the pharmaceutical utility of the root of Fukuchiyama-jio, which was produced as the hybrid of Rehmannia glutinosa LIBOSCH. var. purpurea MAKINO (Akaya-jio in Japanese) and Rehmannia glutinosa LIBOSCH. forma hueichingensis HSIAO (Kaikei-jio in Japanese) (Scrophulariaceae), we have investigated the chemical constituents of the root of Fukuchiyama-jio in detail in comparison with those of Akaya-jio and Kaikei-jio. Chemical analysis as well as quantitative one by means of gas liquid chromatography (GLC) have shown that the root of Fukuchiyama-jio contains a larger amount of iridoid glucosides as compared with Akaya-jio and Kaikei-jio. During these chemical analyses, a new ionone glucoside named oxyrehmaionoside B (7) along with melasmoside (6) were isolated as the characteristic constituents of Fukuchiyama-jio and the structure of 7 has been determined.

Chromatography, Gas↗
PubMed1998

[Quantitative determination of constituents in various licorice roots by means of high performance liquid chromatography].

During the course of our studies on the chemical constituents of botanically identified Chinese licorice roots of various origins, we have identified 15 kinds of saponins and 49 kinds of flavonoids (including flavonoid glycosides). With these chemical constituents at hand, we have carried out the chemical evaluation studies of licorice roots available in Japan by means of high performance liquid chromatography (HPLC). In the HPLC analysis using an ODS reversed-phase column, a combination of 1% aqueous acetic acid and acetonitrile was used as the mobile phase in a gradient solvent system, and the eluate was monitored with UV absorption at 254 nm (for saponins with a diene or a conjugated carbonyl moiety, liquiritin, and liquiritin apioside) or at 350 nm (for other flavonoid constituents). By our analytical method described here, quantitative analyses of saponin and flavonoid constituents were effected simultaneously. We have found an interesting piece of information concerning the origin of parent plants and their characteristic constituents such as saponins and flavonoids.

Chromatography, High Pressure Liquid↗
PubMed1998

Adrenal hemorrhage associated with Klebsiella oxytoca bacteremia.

Septic adrenal hemorrhage is classically caused by meningococcemia. An autopsied case is presented of a 45-year-old man with adrenal hemorrhage due to Klebsiella oxytoca bacteremia following placement of a central venous catheter. He died 5 hours after developing disseminated intravascular coagulation (DIC). The bacterial entry site may have been the catheter. The cause of death was considered to be pulmonary edema due to bacteremia rather than adrenal insufficiency due to hemorrhage. Septic adrenal hemorrhage should be recognized as a subtype of sepsis rather than adrenal insufficiency, and may be caused in conditions of severe sepsis with DIC, independent of the microorganic variety.

Adrenal Gland Diseases↗