Biomedical subjects

H Ashida

Publications and source records attributed to H Ashida.

At least 55 records · Page 3Linked to original sources

PubMed2000

[A case of spontaneous cervical carotid artery dissection managed by using primary stent placement].

The authors report the case of a 35-year-old male who underwent stenting for spontaneous cervical carotid dissection. He presented with sudden onset of hemicrania and left facial palsy followed by left hemiparesis and dysarthria. On admission, carotid angiography revealed postsinus tapering occlusion of the right internal carotid artery. Initially, he was managed with conservative treatment, but his neurological status deteriorated. Findings of brain CT, MRI and IMP-SPECT suggested hypoperfusion of the right cerebrum. A Palmaz stent, 39 mm in length, was successfully placed over the site of the dissection to restore normal patency through the dissected carotid artery. Following stent implantation, his neurological signs improved gradually but completely. Since the procedure, with oral administration of antiplatelet medication, he has suffered no cerebral ischemic events. Follow-up carotid angiography one year after stent implantation showed good patency of the stented segment. The present case emphasizes the usefulness of stenting for spontaneous cervical carotid dissection.

Adult↗

PubMed2000

[Midazolam-atropine lollipop for pediatric premedication].

Strawberry flavored sweet lollipop containing midazolam (5 mg) and atropine (0.25 mg) was evaluated for the premedication of pediatric patients as judged by sedative and anti-anxious effects and gastric fluid volume and acidity. The subjects of this prospective, double blind, random and controlled study were 175 children aged between 6 months and 10 years. They were divided into three groups: group A patients receiving the lollipop containing only 5 mg midazolam (n = 78), group B patients receiving the lollipop containing only 0.25 mg atropine (n = 21), and group C patients receiving the lollipop containing 5 mg midazolam and 0.25 mg atropine (n = 76). The plasma midazolam concentration was measured in ten children in group A. The sedative and anti-anxious effects were scaled with four levels. The children receiving the lollipop containing midazolam (group A and C) showed a better level of the sedative and anti-anxious state. The volume of gastric fluid of group A was more than those of group B and C. The pH of group A gastric fluid was also higher than those of other groups. The correlation equation of the plasma midazolam concentration (y ng.ml-1) against time (t min) was y = 149 x e(-t/64), (r = 0.775). These results suggest that midazolam-atropine lollipop is one of the favorable choices as the premedication for pediatric patients.

Adjuvants, Anesthesia↗

PubMed2000

[The influence of the use of mupirocin nasal ointment on the incidence of endogenous MRSA infections in an intensive care unit].

Nasal carriage of MRSA is a significant risk-factor for the endogenous MRSA infection in immunocompromised patients. MRSA infection in ICU patients is thus mostly endogenous infection. To evaluate the impact of mupirocin use on the incidence of endogenous infection caused by MRSA in an intensive care unit, we prospectively treated all patients in the unit with mupirocin, 3 times daily for 3 days. This routine use of mupirocin led to eradication of nasal MRSA carriage in 81.8% of surveillance cultures and to a significant reduction in the total incidence of MRSA infection among MRSA carrier patients (0 episode in 11 patients) when compared to historical controls prior to the use of mupirocin (3 episodes in 7 patients). Mupirocin nasal ointment was significantly effective to prevent endogenous MRSA infection.

Administration, Intranasal↗

PubMed1999

Posttraumatic intra-gallbladder hemorrhage in a patient with liver cirrhosis.

We report a case of intra-gallbladder hemorrhage secondary to blunt abdominal trauma in a patient with liver cirrhosis. A 58-year-old man was admitted to a local hospital with persistent right upper quadrant abdominal pain. Anemia was detected, and computed tomography (CT) revealed a high-density mass in the gallbladder lumen. He was transferred to our hospital because a gallbladder tumor was suspected. He had a history of habitual alcohol abuse and had sustained blunt abdominal trauma in the right upper quadrant 29 days before admission to our hospital (4 days before to the admission local hospital). The intra-gallbladder high-density mass depicted on the CT scan, observed as non-shadowing low-level echoes, was deemed to represent a blood clot on ultrasonography (US) performed 31 days after the trauma. US-guided percutaneous transhepatic gallbladder aspiration and cholecystography confirmed the presence of an old blood clot in the lumen. Because of the patient's persistent pain, a cholecystectomy was performed. The distended gallbladder was filled with old clotted blood.

Cholecystography↗

PubMed1999

Comparison in metabolic activity of cytochrome P450 1A1 on heterocyclic amines between human and rat.

In mutagenicity and antimutagenicity tests, the toxicants have been activated to the ultimate mutagenic forms usually with rat cytochrome P450 (CYP) enzymes. An understanding is important of whether these data can be available for human. In this paper are compared the activating abilities of CYP1A1 between human and rat using recombinant yeast cells that express respective CYP1A1 and yeast NADPH-CYP-oxidoreductase simultaneously. Three different types of dietary procarcinogens, heterocyclic amines, were tested by two methods: a bioassay with Salmonella mutagenicity test and a chemical determination of N-hydroxyls as the ultimate mutagenic forms. Compared with ED(50) values, saturation levels, and V(max)/K(m) values at an initial stage of the enzyme activity, human and rat CYP1A1 showed almost similar abilities for the metabolic activation on heterocyclic amines. The two enzymes also had the same preference for the tested procarcinogens and the same affinities to the specific inhibitors such as flavonoids.

Amines↗

PubMed1999

Expression of a gene for cyclophilin which contains an amino-terminal endoplasmic reticulum-targeting signal.

We isolated a novel gene for cyclophilin (CyP) first identified as an intracellular target of the immunosuppressant cyclosporin A and also known to have peptidyl-prolyl cis-trans isomerase (PPIase) activity, named ATCYP5 from Arabidopsis thaliana. ATCYP5 encoded a polypeptide with 201 amino acids with a putative ER-targeting signal sequence at its N-terminal, but without the typical ER-retention signal in its C-terminal. In addition, ATCYP5 protein contained a seven amino-acid long sequence which has been found previously only in cytosolic CyPs from plants. The synthetic mutant green fluorescent protein (sGFP; S65T) was fused to the N-terminal part of ATCYP5, and expressed in tobacco BY-2 cells. The fluorescence derived from the fusion protein was detected mainly around the nucleus, indicating translocation into ER. ATCYP5 was expressed mainly in young stems especially in the apical region and weakly in leaves and roots.

Amino Acid Sequence↗

PubMed1999

Cold-adapted alanine dehydrogenases from two antarctic bacterial strains: gene cloning, protein characterization, and comparison with mesophilic and thermophilic counterparts.

The genes encoding NAD(+)-dependent alanine dehydrogenases (AlaDHs) (EC 1.4.1.1) from the Antarctic bacterial organisms Shewanella sp. strain Ac10 (SheAlaDH) and Carnobacterium sp. strain St2 (CarAlaDH) were cloned and expressed in Escherichia coli. Of all of the AlaDHs that have been sequenced, SheAlaDH exhibited the highest level of sequence similarity to the AlaDH from the gram-negative bacterium Vibrio proteolyticus (VprAlaDH). CarAlaDH was most similar to AlaDHs from mesophilic and thermophilic Bacillus strains. SheAlaDH and CarAlaDH had features typical of cold-adapted enzymes; both the optimal temperature for catalytic activity and the temperature limit for retaining thermostability were lower than the values obtained for the mesophilic counterparts. The k(cat)/K(m) value for the SheAlaDH reaction was about three times higher than the k(cat)/K(m) value for VprAlaDH, but it was much lower than the k(cat)/K(m) value for the AlaDH from Bacillus subtilis. Homology-based structural models of various AlaDHs, including the two psychotropic AlaDHs, were constructed. The thermal instability of SheAlaDH and CarAlaDH may result from relatively low numbers of salt bridges in these proteins.

Adaptation, Physiological↗

PubMed1999

Two cytosolic cyclophilin genes of Arabidopsis thaliana differently regulated in temporal- and organ-specific expression.

We have previously isolated two closely related genes (ATCYP1 and ATCYP2) each encoding a cytosolic cyclophilin of Arabidopsis thaliana. Here we tested expression patterns of these two genes by Northern analysis and by histochemical analysis with transgenic plants carrying the promoter: beta-glucuronidase (GUS) fusion. The results showed that ATCYP1 is predominantly transcribed in vascular tissue and flowers, but ATCYP2 is at higher levels in younger leaves. The different expression patterns seemed to be conferred by the quite different promoter structures carrying various cis elements. Our finding suggests that the two cyclophilins have different roles in Arabidopsis thaliana cells.

Arabidopsis↗

PubMed1999

[A case in which palatal squamous cell carcinoma responded to UFT therapy].

We administered UFT to a 70-year-old female with squamous cell carcinoma of the palatal mucosa (T1 N0 M0) who had not consented to radical surgical treatment. The tumor disappeared grossly and histopathologically after 1 month, and no adverse reaction to oral administration of UFT was noted. The patient remains under observation.

Administration, Oral↗

PubMed1999

EEG topographical analysis of spatial disorientation.

BACKGROUND: We examined EEG topography while subjects experienced spatial disorientation (SD) such as vection and somatogravic illusion (SGI). METHODS: Five healthy male subjects were exposed to a rotating image evoking vection (Experiment 1) and to a 0.58 G linear forward acceleration evoking SGI (Experiment 2). The data were analog-to-digital converted with an epoch length of 1 s and a sampling frequency of 256 Hz. Polynomial coefficient vectors were calculated for the following analyses of EEG under the illusion: a) objective evaluation of topographical difference by two-way MANOVA; b) visual inspection of the power spectra maps; and c) logarithmic deviation ratio topography (log DRT). RESULTS: MANOVA demonstrated significant differences in EEG topography in the high alpha band while the vection was evoked. No significant difference was revealed in any bands for SGI. Characteristic patterns common to all subjects were hardly identified on the power spectra maps. By log DRT under vection, a decrease of power was observed in the centro-parietal area on the left side in one subject, on the right in another subject, and in the mid-right frontal area in a third subject compared with the control with eyes open. As for SGI, log DRT revealed a decrease of power in the occipital area in most of the trials as the magnitude was reduced by a visible horizon. CONCLUSIONS: MANOVA revealed a significant change in EEG topography while the subjects felt vection. Log DRT reflected characteristic patterns under vection and SGI. Thus EEG topography may be useful for the study of SD.

Acceleration↗

PubMed1999

[A case of subarachnoid hemorrhage verified as cerebral vasospasm by using three-dimensional CT angiography (3 D-CTA): reference to comparison with conventional angiography].

The authors present a case of aneurysmal subarachnoid hemorrhage that were verified as cerebral vasospasm by using both three-dimensional CT angioraphy (3 D-CTA) and conventional angiography. A 45-year-old man was referred to our department 4th day after sudden onset of a severe headache. On admission, emergency 3 D-CTA showed the cerebral vasospasm involving M 1 segment. Conventional angiography performed at the same day of the left internal carotid artery confirmed the cerebral vasospasm of the same vessel as 3 D-CTA, and furthermore demonstrated the left middle cerebral artery (MCA) and anterior cerebral artery (ACA) genu aneurysms. The former was seen as a ruptured aneurysm from brain CT findings (Fisher group 3). On the 10th day after the onset, 3 D-CTA demonstrated the remaining severe cerebral vasospasm of the supraclinoid portion of left ICA and M 1 segment. Findings at the conventional angiography subsequently performed were concordant with those of 3 D-CTA. The patient was successfully treated with delayed surgical clipping for both aneurysms without the symptoms related to the cerebral vasospasm and discharged without neurological abnormality. We consider that 3 D-CTA shows promise as a minimally invasive method of evaluating the cerebral vasospasm and would take the place of the conventional angiography.

Cerebral Angiography↗

PubMed1998

Kinetic analysis of the mechanism of action of the multidrug transporter.

To clarify the mechanistic role of PGP (P-glycoprotein) in multidrug transport, we constructed a kinetic model composed of four compartments: (1) the extracellular space; (2) the space in the membrane; (3) the intracellular space; and (4) the pore-like space in the PGP molecule. The kinetics of the concentration of ADM (adriamycin) in each compartment were formulated based on the assumptions that (a) the movement of ADM between two compartments by diffusion is dependent on a dynamic distribution coefficient introduced here, (b) the uptake of ADM into the pore-like structure by the pump mechanism activated by ATP is described by enzyme kinetics, (c) the movement of ADM out of the pore-like structure to the extracellular medium through a valve-like mechanism is also expressed by enzyme kinetics. The mathematical analysis of the exact solution can explain the distinct effects of verapamil and vanadate on the accumulation and release of ADM, where verapamil inhibits the efflux by the valve-like mechanism and vanadate blocks the influx by the pump mechanism. We also performed a numerical calculation with this model for a quantitative explanation and found the valid parameter values to fit the experimental data. These results support the modified hydrophobic vacuum cleaner model.

ATP Binding Cassette Transporter, Subfamily B, Mem↗

PubMed1998

Catabolic fate of dietary trilinoleoylglycerol hydroperoxides in rat gastrointestines.

To elucidate whether dietary lipid peroxides are absorbed in the body, the catabolic fate of trilinoleoylglycerol hydroperoxides (TL-OOH), in the gastrointestines of rats was examined. Oxidized trilinoleoylglycerol with a peroxide value of 1000 meq/kg, 0.5 or 20 mg, was dosed intragastrically to rat together with 59.5 or 40 mg unoxidized trilinoleoylglycerol, respectively. The fate of TL-OOH in gastric and intestinal lumina was determined by high-performance liquid chromatography periodically until 240 min after treatment. At low dose, TL-OOH was soon broken down to linoleic acid hydroperoxides (LA-OOH) and hydroxyls, probably through gastric lipases, whereas at high dose, TL-OOH was retained in the stomach. In both cases, TL-OOH did not reach the intestines, though the unoxidized lipids moved to the intestines. When LA-OOH was given intragastrically, the lipids decomposed in the stomach, and linoleic acid hydroxyls, hexanal, 9-oxononanoic acid, and two novel compounds were detected 30 min after treatment. The novel compounds were identified to be epoxyketones, 11-oxo-12,13-epoxy-9- and 11-oxo-9,10-epoxy-12-octadecenoic acids. Thus, dietary TL-OOH was broken down in the stomach releasing, LA-OOH which decomposed further, and did not reach the intestines.

Animals↗

PubMed1998

Dietary hydroperoxides of linoleic acid decompose to aldehydes in stomach before being absorbed into the body.

Our previous study (Biochim. Biophys. Acta 1393 (1998) 336-348, this issue) found that dietary hydroperoxides of trilinoleoylglycerol were broken down, releasing linoleic acid hydroperoxides (LA-OOH) in the stomach without reaching the intestines. The present paper describes the catabolic fate of LA-OOH in rat gastrointestines, in an attempt to elucidate those products which can be absorbed into the body. At an intragastric dose of 6.5 or 18 mumol, LA-OOH was not transported to the intestines as determined by HPLC. At large doses (200 or 800 mumol), much greater than that in the daily diet, there was partial leakage of LA-OOH to the intestines. The periodical fate was analyzed with 17.2 mumol [U-14C]LA-OOH chemically and radiochemically. Exemplifying the product composition at 30 min after treatment (as percentage of dosed amount), 27% unchanged LA-OOH, 9.7% epoxyketones, 3.5% hydroxyls (LA-OH), 2.4% decomposed aldehydes, and 13% unknown products were found in the gastric lumen. Another 25% was incorporated in the gastric tissue, and the other 6.4% occurred in the intestinal lumen and tissue as decomposed aldehyde. The LA-OH further decomposed to aldehydes with time in the stomach. When an aldehyde mixture was prepared and dosed, significant increases in hexanal and 4-hydroxynonenal were detected in the liver 15 h later. These results show that the dietary LA-OOH is decomposed to aldehydes in the stomach and that aldehydes are partly absorbed into the body.

Aldehydes↗

PubMed1998

Effect of in vivo administered 2,3,7,8-tetrachlorodibenzo-p-dioxin on DNA-binding activities of nuclear transcription factors in liver of guinea pigs.

To study the long-term effect of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) on the DNA-binding activity of nuclear transcription factors; a single dose of TCDD was injected intraperitoneally to male guinea pigs (1 microgram/kg i.p.). The animals were killed after 1, 2, 10, 20, 28, and 40 days, and DNA-binding activities in liver nuclear fraction were assessed through electrophoretic gel mobility shift assay (EMSA). As expected, the nuclear protein binding to dioxin or xenobiotic response element (DRE or XRE) increased as a result of TCDD's action (1-20 days). In addition, protein binding to 32P-labeled activator protein-1 (AP-1) response element (RE) (1-28 days) and activator protein-2 (AP-2) RE (1-28 days) were all increased by the action of TCDD. On the other hand, TCDD treatment significantly lowered the nuclear protein binding to both specific protein-1 (Sp-1) RE and c-MycRE at all time points (1-40 days). In the case of protein binding to 32P-labeled cAMP response element (CRE), we found two groups of binding bands being affected by TCDD. The intensity of the upper band group decreased, and that of the lower band group increased. As for AP-1 proteins, judging by the results of the Western blotting assay, the level of c-Fos increased while that of c-Jun decreased with TCDD treatment both at day 1 and 28. It is known that the rise in AP-1 and AP-2 activities often results in lowering certain cell differentiation signaling messengers in the nucleus. In agreement with this scenario, binding of C/EBP (CCAAT enhancer binding protein) to its response element site was found to be suppressed for 1 through 28 days. Among hormone receptors, TCDD treatment decreased the binding to retinoic acid RE but increased the binding to thyroid hormone RE.

Adipose Tissue↗

PubMed1998

Purification and characterization of a mannose/glucose-specific lectin from Castanea crenata.

A hemagglutinin was purified from the cotyledons of Japanese chestnut (Castanea crenata Sieb. et Zucc.) by affinity chromatography on asialo-fetuin Sepharose 4B column followed by anion-exchange and gel permeation chromatography. The hemagglutinating activity of Castenea crenate agglutinin (CCA) was strong for sialidase-treated human erythrocytes, but was inhibited by mannose, glucose, and their derivatives as well as by glycoproteins having an N-linked complex carbohydrate type. The apparent M(r) of intact CCA was determined to be ca 257,000 by gel filtration using a Superose 12 column. In SDS-PAGE, under reducing and non-reducing conditions, CCA migrated as a single band of M(r) 37,000. Therefore, the intact CCA may be composed of six or eight identical subunits without disulfide bonds. In addition, CCA showed strong mitogenic activity similar to other lectins. The N-terminal amino acid of CCA may be blocked since no amino acid was detected by direct sequence analysis. Amino acid analysis showed that CCA was rich in glycine, but did not contain cysteine residues. Some properties of CCA were similar to mannose/glucose-specific legume lectins, but our data suggest that the molecular structure of CCA is different.

Agglutination Tests↗

PubMed1998

Tryptophan pyrolysis products, Trp-P-1 and Trp-P-2 induce apoptosis in primary cultured rat hepatocytes.

The cytotoxicity of heterocyclic amines, dietary carcinogens derived from cooked foods, to primary cultured rat hepatocytes was studied. A tryptophan pyrolysis product, 3-amino-1,4-dimethyl-5H-pyrido[4,3-b]indole (Trp-P-1) was the most cytotoxic of 11 compounds tested. Trp-P-1 was found to induce apoptosis as measured by morphological changes in nuclear chromatin and internucleosomal DNA fragmentation. 3-Amino-1-methyl-5H-pyrido[4,3-b] indole (Trp-P-2) showed a moderate apoptotic effect, and other compounds had a similar but weaker effect.

Animals↗

PubMed1998

Antimutagenicity of flavones and flavonols to heterocyclic amines by specific and strong inhibition of the cytochrome P450 1A family.

We found the mechanism in flavonoids that can strongly suppress the mutagenicity of one of the food-derived and carcinogenic heterocyclic amines, 3-amino-1-methyl-5H-pyrido[4,3-b]indole (Trp-P-2). The antimutagenicity was evaluated by IC50 value, the amount required for 50% inhibition of the mutagenicity of 0.1 nmol Trp-P-2, with Salmonella typhimurium TA98 strain in the presence of S9 mix. The flavones and flavonols were two orders stronger as antimutagens that such antimutagenic phytochemicals as chlorophylls and catechins. We had previously found flavonoids to be a desmutagen to neutralize Trp-P-2 before or during attack of DNA, because they had no effect on either the ultimate mutagenic form of Trp-P-2 (N-hydroxy-Trp-P-2) or the mutated cells. The desmutagenicity of the flavonoids did not depend on the hydroxy number or position that should be associated with antioxidative potency, and was also unaffected by the solubility of Trp-P-2 in the assay solution. The inhibitory effect of the flavonoids on the metabolic activation of Trp-P-2 to N-hydroxy-Trp-P-2 was almost in parallel with the antimutagenic IC50 value, when determined with a Saccharomyces cerevisiae AH22 cell simultaneously expressing both rat cytochrome P450 1A1 and yeast reductase. The Ki values of flavones and flavonols for the enzyme were less than 1 microM, while the K(m) value of Trp-P-2 was 25 microM. The antimutagenicity of the flavones and flavonols was thus concluded to be due to inhibition of the activation process of Trp-P-2 by P450 1A1 to the ultimate carcinogenic form. They were also able to act as antimutagens toward other indirect mutagens that were activated by P450 1A1.

Animals↗