Biomedical subjects

K Taki

Publications and source records attributed to K Taki.

At least 37 records · Page 2Linked to original sources

PubMed1999

The SOS response is induced by replication fork blockage at a Ter site located on a pUC-derived plasmid: dependence on the distance between ori and Ter sites.

A new model system for the study of the SOS response has been developed. In this system the response is induced by blocking the replication fork at a Ter site located in pUC-derived plasmids. Blockage of the fork is dependent on the expression of the Ter binding protein, Tus, encoded on another plasmid, in which the tus gene is under the control of the ara promoter. SOS induction can, therefore, be controlled by arabinose. The extent of the SOS response was monitored by measuring the activity of beta-galactosidase, expressed from a lacZ gene fused to the 5' region of the sfiA gene, a typical SOS-responsive gene. Expression of the fusion gene is completely dependent on recA+ and lexA+ genes. Using this system, we found that the distance between the ori and Ter sites is directly correlated with the strength of SOS induction. The properties of this system are discussed.

Bacterial Proteins↗

PubMed1999

Monokine stimulation of interleukin-11 production by human vascular smooth muscle cells in vitro.

Human vascular smooth muscle cells (VSMC) are a component of blood vessels, and secrete a variety of cytokines in atherosclerotic loci. Interleukin-11 (IL-11), a member of IL-6-like cytokines, is reported to be involved in inflammation and tissue remodeling, both of which are observed in atherosclerosis. However, no information is available as to the production of IL-11 by VSMC. Therefore, the expression of IL-11 in VSMC is investigated. The amounts of IL-11 protein and mRNA were determined by enzyme-linked immunosorbent assay (ELISA) and Northern blot analysis, respectively. The expression of IL-11 in VSMC was also immunohistochemically determined. IL-1 alpha, transforming growth factor-beta (TGF beta) and, to a lesser extent, tumor necrosis factor-alpha (TNF alpha) stimulated the IL-11 production by VSMC, and the stimulatory effects of IL-1 alpha and TGF beta on IL-11 production were dose-dependent. IL-1 alpha and TNF alpha synergistically augmented TGF beta-stimulated IL-11 production by VSMC. Immunohistochemical staining also revealed the expression of IL-11 protein in VSMC. Furthermore, IL-1 alpha, TGF beta, and TNF alpha induced IL-11 gene expression in VSMC. Because IL-6-like cytokines are reported to be cytoprotective, monokine-stimulated IL-11 may have a potent protective role in atherosclerotic lesions.

Arteriosclerosis↗

PubMed1999

Permissive role of brain allopregnanolone content in the regulation of pentobarbital-induced righting reflex loss.

Allopregnanolone [3alpha-hydroxy-5alpha-pregnan-20-one] (ALLO), a potent neurosteroid that positively modulates gamma-aminobutyric acid (GABA) action at various GABA(A) receptor subtypes is synthesized in nanomolar concentrations and stored non uniformly in various brain structures of mammals. We have measured brain ALLO content and its precursors by negative ion chemical ionization-mass-spectrometry after purification and separation of the different steroids with HPLC and gas chromatography. Our procedure measures steroids in the femtomolar range with structural information and unsurpassed selectivity. We were able to establish an association between the decrease in content of ALLO in mouse brain cortex elicited by either long-lasting social isolation or by the administration of 17beta-17 [bis (1-methylethyl) amino carbonyl] androstane-3,5-dilene-3-carboxylic acid (SKF 105111). an inhibitor of Types I and II 5alpha reductases, and the shortening of the righting reflex loss elicited by pentobarbital (PBT). SKF 105111 added to cortical brain slices in concentrations up to 10(-5) M failed per se to alter GABAergic currents or their potentiation by PTB recorded from pyramidal neurons. Fluoxetine (1.45 or 2.9 micromol/kg i.p.) doses that fail to change the PTB-induced loss of righting reflex and the level of brain ALLO in group-housed mice normalized both parameters in socially-isolated mice. In addition, we could detect both fluoxetine actions in socially isolated mice pretreated with doses of p-chlorophenylalanine (1.2 mmol/kg i.p. at 72, 48, and 24 h) that substantially inhibit brain serotonin 5HT synthesis as shown by an 80% drop of brain 5HT content. These studies for the first time have provided evidence suggesting that the endogenous cortical stores of ALLO physiologically upregulate GABAergic tone and by such a mechanism play a permissive or facilitatory role on the PTB-induced loss of the righting reflex. In the absence of such a permissive physiological influence by endogenous ALLO, the righting reflex inhibition by PTB is down regulated.

5-alpha Reductase Inhibitors↗

PubMed1999

Nuclear matrix protein levels in burn patients with multiple organ dysfunction syndrome.

In this study, we investigated multiple organ dysfunction syndrome (MODS) and nuclear matrix protein (NMP), which is an indicator for apoptosis, in burn patients. The subjects were 17 patients with a total burn surface area (TBSA) of 26% or more. Eight of them had MODS, and nine did not. Seven patients died, and 10 survived. The NMP value in the group with MODS (610 +/- 318 units/ml) was significantly higher than in the group without MODS (82 +/- 31 units/ml). The NMP values of the patients who died (645 +/- 326 units/ml) were significantly higher than in the group who survived (111 +/- 95 units/ml), and they rose significantly as the number of impaired organs increased. Our findings suggested that the NMP level in burn cases associated with MODS was higher when apoptosis developed and larger numbers of organs were impaired.

Adult↗

PubMed1999

Effect on locomotion of indole alkaloids from the hooks of uncaria plants.

Three predominant Uncariae plants, Uncaria rhynchophylla U. sinensis and U. macrophylla and their indole and oxindole alkaloid constituents were studied for their effect on locomotor response. Water extracts of U. macrophylla and U. sinensis and four indole alkaloids, corynoxine, corynoxine B, isorhynchophylline and geissoschizine methyl ether, significantly decreased locomotor activity after oral administration to mice. The depression of locomotor activity upon administration of these alkaloids appears to be due to mediating of the central dopaminergic system.

Alkaloids↗

PubMed1999

Elimination of CO2 in patients with carbonic anhydrase II deficiency, with studies of respiratory function at rest.

We evaluated the elimination of CO2 in three Japanese adults with carbonic anhydrase II (CA II) deficiency, as compared with that in 10 healthy volunteers. The patients had no signs of respiratory distress. Heart rate, body temperature, ventilation volume, respiratory rate and (a-ET) PCO2 were found to be higher and PaCO2 tended to be higher in the patients than those in the volunteers, while forced vital capacity (FVC), forced expiratory volume in 1s (FEV1), tidal volume, end-tidal PCO2 (PETCO2), pH and HCO3- in arterial blood were lower in the patients. All three patients had non-anion-gap metabolic acidosis, due to renal losses of bicarbonate, but with virtually no compensatory reduction in PaCO2. However, the high VE and PaO2 suggested that respiratory compensation for this metabolic acidosis was occurring, the elimination of CO2 was possibly facilitated by the presence of other carbonic anhydrase isoenzymes in the pulmonary capillaries. Thus, CA II deficiency causes mild to moderate impairments in CO2 elimination.

Adolescent↗

PubMed1999

Retrograde intra-arterial infusion of prostaglandin E1 and heparin for the no-reflow phenomenon after oromandibular reconstruction with a free fibular flap.

The authors encountered a patient with a tumor of the floor of the mouth in whom the no-reflow phenomenon occurred after excision of the lesion and the mandible, followed by reconstruction using a free fibular flap. A catheter was inserted retrogradely from the point where the peroneal artery had been ligated at the time of flap preparation. Continuous intra-arterial infusion of prostaglandin E1 and heparin was performed, and the flap survived. This method salvaged free flaps subject to the no-reflow phenomenon.

Alprostadil↗

PubMed1999

Cascade of acetazolamide-induced vasodilatation.

UNLABELLED: Acetazolamide (AZ) has been found to be effective in inducing vasodilatation. To evaluate the mechanism by which AZ acts, we compared the effects of this agent on vascular PGI2, endothelin (ET-1), and NOx, with those induced by CO2 gas inhalation. METHOD: Blood flow (BF) was measured in the liver, kidneys, stomach wall, and abdominal muscle of anesthetized white rabbits with a laser flow meter at baseline and again after sequential doses of AZ (4 mg/kg) or CO2 inhalation. Cardiac output and serum concentrations of PGI2, ET-1, and NOx were also measured in these animals. RESULTS: AZ increased BF in the liver and kidneys, but had no effect on BF in the stomach wall or abdominal muscle. The level of NOx was decreased following the administration of AZ, while PGI2 and ET-1 levels remained unchanged. In contrast, CO2 inhalation increased PCO2, and decreased pH, significantly. CO2 elevated BF in the liver, kidneys, stomach wall, and abdominal muscle, as well as serum levels of PGI2 and ET-1, while having no effect on NOx levels. The alterations in BF, PGI2, ET-1, and NOx in response to AZ, suggest that the mechanism of AZ-induced vasodilatation may involve a cascade that is triggered by CO2 retention similar to that caused by the inhalation of CO2.

6-Ketoprostaglandin F1 alpha↗

PubMed1999

Involvement of spinal delta 1-opioid receptors in forced walking stress-induced antinociception in the tail-flick test in mice.

The purpose of this study was to elucidate the involvement of spinal delta-opioid receptor subtypes in forced walking stress-induced antinociception mice. We first confirmed that forced walking stress produced walking duration-dependent antinociception in mice as determined by the tail-flick test. Intrathecal treatment with 7-benzylidenenaltrexone, a selective delta 1-opioid receptor antagonist, significantly attenuated forced walking stress-induced antinociception. In contrast, intrathecal treatment with naltriben, a selective delta 2-opioid receptor antagonist, had no significant effect on forced walking stress-induced antinociception. Intracerebroventricular treatment with either 7-benzylidenenaltrexone or naltriben had no effect on the forced walking stress-induced antinociception. These results suggest that forced walking stress-induced antinociception is mediated by spinal delta 1-opioid receptors in mice.

Analgesics↗

PubMed1998

A clinical, genetic, neuropathological study in a Japanese family with SCA 6 and a review of Japanese autopsy cases of autosomal dominant cortical cerebellar atrophy.

This report concerns a Japanese family with genetically confirmed SCA 6, including an autopsy case, and a review of Japanese autopsy cases of autosomal dominant cortical cerebellar atrophy (ADCCA). The proband (Case 1) was a Japanese woman. She developed gait disturbance at age 62. The father and younger sister (Case 2) had the same disorder. She died at age 67 due to subarachnoid hemorrhage. Neuropathological examination revealed severe loss of Purkinje cells in the cerebellum, prominently in the dorsal vermis, and absence of neuronal loss in the inferior olives. Molecular genetic study showed the CAG-repeat expansion of SCA 6 gene. The younger sister (Case 2) developed gait disturbance at age 62. Neurological examination at age 66 revealed cerebellar signs without sensory disturbance. Neuroimaging at this time showed cerebellar atrophy, prominently in the vermis. She died of multiple myeloma at age 66. A neuropathological review of Japanese autopsy cases of ADCCA showed that there are two patterns in the distribution of cerebellar cortical lesions of Japanese patients with ADCCA. The distribution of cerebellar cortical lesions in genetically confirmed Japanese patients with SCA 6 is more prominent in the vermis than in the hemisphere.

Aged↗

PubMed1998

Distribution of cerebellar cortical lesions in multiple system atrophy: a topographic neuropathological study of three autopsy cases in Japan.

We investigated neuropathologically the distribution of the cerebellar cortical lesions in three Japanese autopsy cases of multiple system atrophy (MSA) using hemisphere specimens. The lesions were classified as mild, moderate or severe. The distribution of cerebellar cortical lesions in all three cases were uniform: the cerebellar cortical lesions were more conspicuous in the vermis than in the hemisphere. These neuropathological findings differ from the established theory that cerebellar lesions of MSA are more pronounced in the hemisphere than in the vermis. The degree of cerebellar cortical lesions in our cases increased in relation to the duration of the disease. Our pathological data may contribute to the morphological differential diagnosis in various neurodegenerative disorders including late cortical cerebellar atrophy. Our neuropathological findings may also make a contribution to the neuroradiological progress in the differential diagnosis of spinocerebellar disease.

Brain Mapping↗

PubMed1998

Acetazolamide-induced increase in blood flow to rabbit organs is confirmed using colored microspheres.

Inhibitors of carbonic anhydrase activity have been found to increase blood and organ PCO2 and to increase blood flow (BF) in individual organs. To determine whether carbonic anhydrase inhibition coordinately induces an increase in BF in several organs, we assayed the effect of the carbonic anhydrase inhibitor, acetazolamide (AZ), on BF in rabbit organs using the colored microsphere (CM) assay. Eight female white rabbits were anesthetized with ketamine and urethane, and administered three sequential doses of 4 mg/kg AZ. After each dose, the rabbits were injected with 9 x 10(5) CMs of different colors, and arterial blood was collected. We found that AZ had no effect on blood pressure, body temperature, hemoglobin concentration, or PaCO2. In contrast, 12 mg/kg AZ significantly increased PaO2 and significantly decreased base excess. When we measured organ BF, we observed, in response to 12 mg/kg AZ, an 82% increase in brain BF and a 55% increase in kidney BF, but no change in BF of the liver, stomach wall, or abdominal muscle. These findings suggest that the inhibition of carbonic anhydrase activity by AZ, which decreases the rate of CO2 conversion to HCO3-, causes the retention of CO2 in tissues and organs, and thus increases BF in specific organs. Administration of carbonic anhydrase inhibitors, such as AZ, may increase BF to the brain and kidney without reducing PaO2, thereby increasing the supply of oxygen in conditions involving hypoxia such as ischemia and shock.

Acetazolamide↗

PubMed1998

Regulatory mechanisms in expression of the traY-I operon of sex factor plasmid R100: involvement of traJ and traY gene products.

BACKGROUND: The plasmid R100 encodes tra genes essential for conjugal DNA transfer in Escherichia coli. Genetic evidence suggests that the traJ gene encodes a positive regulator for the traY-I operon, which includes almost all the tra genes located downstream of traJ. The molecular mechanism of regulation by TraJ, however, is not yet understood. traY is the most proximal gene in the traY-I operon. TraY promotes DNA transfer by binding to a site, sbyA, near the origin of transfer. TraY is suggested to have another role in regulation of the traY-I operon, since it binds to two other sites, named sbyB and sbyC, located in the region preceding traY-I. RESULTS: Using a traY-lacZ fusion gene, we showed that the traY-I operon was expressed only in the presence of traJ. The TraJ-dependent expression of traY-I required the E. coli arcA gene, which encodes a host factor required for conjugation. TraJ-dependent transcription occurred from a promoter (named pY) located upstream of traY-I. The isolated TraJ protein was found to bind to a dyad symmetry sequence, named sbj (specific binding site of TraJ), which existed in the intergenic region between traJ and traY-I. We also demonstrated that TraY repressed the TraJ-dependent expression of traY-I at the TraY binding sites, sbyB and sbyC, which overlapped with pY. CONCLUSIONS: TraJ is a protein which binds to the sbj site in the region upstream of the promoter pY and positively regulates expression of the traY-I operon in the presence of the E. coli arcA gene. Since sbj is located 93bp upstream of pY in the intergenic region between traJ and traY-I, TraJ presumably contacts with a transcription apparatus to promote transcription from pY. TraY, which is known to activate the initiation of conjugal DNA transfer, has a new role in the transcriptional autoregulation of traY-I expression. At levels which are sufficient to initiate conjugal DNA transfer, TraY represses traY-I transcription in the presence of TraJ.

Bacterial Outer Membrane Proteins↗

PubMed1998

Effect of oral clonidine premedication on hemodynamic response during sedated nasal fiberoptic intubation.

Although oral clonidine premedication is known to reduce the hemodynamic response under general anesthesia, effects of the hemodynamic response during sedated fiberoptic nasal intubation have not yet been examined. Our aim was to compare the effects of clonidine premedication on hemodynamic responses with those of atropine and hydroxyzine premedication during sedated fiberoptic nasal intubation. Thirty adult patients were randomly assigned to one of two groups: Group 1 patients (n = 15) were premedicated with atropine sulfate (0.01 mg/kg) and hydroxyzine hydrochloride (1mg/kg) intramuscularly, and group 2 patients (n = 15) were premedicated with clonidine (5 micrograms/kg) orally. We compared the hemodynamic response and sedation level in fiberoptic nasal intubation between the two groups. there were no significant differences in sedation levels and postoperative complaints between the two groups. But the oral clonidine premedication (Group 2) blunted hemodynamic changes during the fiberoptic intubation. No profound hypotension or marked bradycardia was noted in group 2. We concluded that the oral clonidine premedication might contribute to hemodynamic stability during sedated fiberoptic nasal intubation.

Administration, Oral↗

PubMed1998

[Coronary artery fistula with left atrial myxoma: report of a case].

A 64-year-old male was referred for surgical treatment of left atrial myxoma. Preoperative coronary angiography revealed coronary artery fistula from the left anterior descending artery and the circumflex artery draining into the main pulmonary artery. Operative treatment was performed including resection of the myxoma, patch closure of the atrial septal defect, and closure of the fistula with pledgeted mattress sutures from within the main pulmonary artery on cardiopulmonary bypass. His postoperative course was uneventful, and disappearance of the left atrial myxoma and the coronary artery fistula was ascertained by echocardiography and coronary angiography.

Arterio-Arterial Fistula↗

PubMed1998

[Difficulty to diagnose the cause of death in emergency room].

We evaluated the diagnoses noted on the medical records of 275 patients admitted to Saga Medical College Hospital during the six-year period 1990-1995: 245 patients with cardiopulmonary arrest on arrival (CPAOA) and 30 patients with cardiopulmonary arrest occurring in the emergency room (CPAER). The most frequent cause of CPAOA was heart disease, and the next frequent cause was respiratory disease. In the CPAER patients, the most frequent cause was heart disease, while the next frequent was acute aortic dissection. There were discrepancies in the respective causes of cardiac arrest between the CPAOA and CPAER patients, which was probably due to difficulty in diagnosis in the emergency room. In the emergency room, the cardiopulmonary resuscitation is the first treatment to be performed for CPAOA, the examination for the cause of cardiac arrest is the next followed after the heart beating. However, the cause of cardiac arrest can not be diagnosed in the emergency room for the CPAOA patients without the successful resuscitation, because the examinations for the cause of cardiac arrest can not be performed for the patients without beating heart in the emergency room. Therefore, it is concluded that there exists a need to improve the training for finding out the abnormal death with the inspection and the medico-legal autopsy. It may be suggested that the training system of forensic medicine is ideal for clinical physician who can study the decision of the diseases ranging from toxicosis to acute cardiopulmonary arrest in both the emergency and the forensic medicine.

Autopsy↗

PubMed1997

Preprodynorphin-, preproenkephalin-, and preprotachykinin-expressing neurons in the rat neostriatum: an analysis by immunocytochemistry and retrograde tracing.

Specific antibodies were produced against C-terminal portions of rat preprodynorphin (PPD), preproenkephalin (PPE), and preprotachykinin A (PPT). PPD, PPE, and PPT C-terminal immunoreactivity was observed in many cell bodies of medium-sized neurons in the rat neostriatum (caudate-putamen). Intense PPE immunoreactivity was found in neuropil of the globus pallidus, whereas intense to moderate PPD and PPT immunoreactivity was distributed in neuropil of the substantia nigra and the entopeduncular nucleus. A double-immunofluorescence analysis revealed that PPE-immunoreactive neostriatal neurons rarely showed immunoreactivity for PPD (<1%) or PPT (<2%). In contrast, more than 95% of PPD-immunoreactive neostriatal neurons showed PPT immunoreactivity, and vice versa. No PPD-, PPE-, or PPT-immunoreactive neostriatal neurons showed immunoreactivity for the markers of neostriatal intrinsic neurons, such as calretinin, choline acetyltransferase, parvalbumin, or somatostatin. When tetramethylrhodamine-dextran amine (TMR-DA) was injected into the substantia nigra, almost all neurons that were labeled retrogradely with TMR-DA showed immunoreactivity for PPD (98%) or PPT (99%), but very few of them exhibited PPE immunoreactivity (1%). After injection of TMR-DA into the globus pallidus, 86%, 17%, and 10% of the retrogradely labeled neurons showed immunoreactivity for PPE, PPD, and PPT, respectively. These results support the notion that the neostriatal projection neurons are divided into at least two groups: The projection neurons of one group contain enkephalins and send projection fibers almost exclusively to the globus pallidus, and the others contain tachykinins and dynorphins/Leu-enkephalin and send projection fibers mainly to the substantia nigra.

Amino Acid Sequence↗

PubMed1997

Emergency extracorporeal life support for patients with near-fatal status asthmaticus.

Extracorporeal life support (ECLS) was used to treat three patients with near-fatal status asthmaticus who did not respond to aggressive medical therapies and mechanical ventilation under controlled permissive hypercapnia. ECLS was instituted in patient 1 because PaCO2 was excessively high and pH was excessively low, in patient 2 because hypoxemia and shock were not responsive to treatment, and in patient 3 because of sustained severe hypotension. ECLS supported adequate gas exchange until pulmonary function improved, diminishing the need for mechanical ventilation and preventing pulmonary complications. Pulmonary dysfunction improved markedly after only 21 to 86 hours of ECLS. Aggressive medical treatments were continued during ECLS. Our findings indicate that ECLS is a useful method for preventing death in patients with near-fatal status asthmaticus.

Adolescent↗