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Biomedical subjects

E Tanaka

Publications and source records attributed to E Tanaka.

At least 235 records · Page 13Linked to original sources
PubMed1998

cis-Diamminedichloroplatinum induces peroxisomes as well as CYP4A1 in rat kidney.

Effects of cis-diamminedichloroplatinum (cisplatin) on rat kidney were investigated. Clinical parameters in rat urine and blood were studied. Blood urea nitrogen (BUN) and creatinine in blood and K+ in urine increased, but Na+ in urine decreased. Contents of total P450 and metabolic activities towards lauric acid and arachidonic acid in rat renal microsomes were not changed by cisplatin treatment. The levels of P450 isozymes (CYP4A1, 4A2, 4A8 and 2C23) were determined in rat renal microsomes by immunoblotting. The levels of CYP4A2 and 4A8 which are lauric acid omega-hydroxylases were not changed, but the levels of CYP2C23 and 4A1 were increased significantly by cisplatin treatment. Effects of clofibrate, a typical inducer for CYP4A1, on rat kidney were compared with those of cisplatin. Clofibrate induced palmitoyl CoA oxidase (a marker enzyme of peroxysome), CYP4A1, and CYP4A2 and reduced triglyceride level in plasma. Cisplatin had similar effects to clofibrate and induced peroxysomes as well as CYP4A1, although the effects were at a lesser extent than those of clofibrate. The induction levels of CYP4A1 correlated with increased levels of BUN. The present findings suggest that induction of P450 by cisplatin may take part in the renal injury or nephrotoxicity of cisplatin.

Animals↗
PubMed1998

A resected case of Mycobacterium szulgai pulmonary disease.

We present the first reported case of Mycobacterium szulgai pulmonary disease that needed surgical resection due to unsuccessful antimycobacterial chemotherapy. The patient was a non-immunocompromised 48-year-old male who presented with hemoptysis and whose sputum cultures repeatedly yielded M. szulgai. Antimycobacterial chemotherapy with isoniazid (INH) and rifampin (RMP)/ethambutol (EMB) for three years had been unsuccessful, and subsequent chemotherapy with RMP, EMB, ethionamide and kanamycin had to be discontinued due to liver dysfunction. Surgical resection was finally performed, and resulted in a favorable outcome. Although M. szulgai pulmonary disease is usually well controlled by antimycobacterial chemotherapy alone, surgical treatment may be necessary in some cases.

Antitubercular Agents↗
PubMed1998

Finite element analysis of the lower lumbar neural arch under facet loading.

To evaluate the mechanical effect of the direction of facet load on the isthmus stresses of the lower lumbar neural arch, stress analyses were performed by using three-dimensional finite element models of isolated L4 and L5 vertebrae with particular emphasis on accurate discretization of the posterior elements. The bilateral symmetric or unilateral facet loads, with a constant magnitude, were applied within the sagittal and transverse planes. The largest maximal principal stress in the neural arch (the largest sigma(max)) tended to be qualitatively similar in L4 and L5. At the physiologic range, the largest sigma(max), observed on the anterior surface of the isthmus, was relatively insensitive to the sagittal plane loadings but sensitive to the transverse plane loadings. The values of the largest sigma(max) of L4 and L5 were low at the more frontally directed facet load. The magnitude and direction of the largest sigma(max) depended upon the facet loadings mainly on the ipsilateral side and partly on the opposite side. The results suggest that the direction of facet load, which may be characterized by the facet orientation, can have mechanical effects on the occurrence and direction of isthmic crack.

Computer Simulation↗
PubMed1998

[A case of miliary tuberculosis with brain tuberculoma, following intraocular tuberculosis].

A 52-year-old woman with visual loss of her left eye consulted a ophthalmology clinic. She was conducted left vitrectomy and administered corticosteroid under the diagnosis of uveitis of unknown cause. But her visual acuity was not improved. Although re-surgery was planned, pus retention was found in her left eye. After her left eye was resected, fever and general malaise appeared suddenly. Her chest X-ray film revealed diffuse micronodular opacities. Acid-fast bacilli were detected from her sputum and identified to be Mycobacterium tuberculosis. She was diagnosed miliary tuberculosis, and then antituberculous chemotherapy consisting of 4 drugs was started. Granulomatous inflammation destructing retina and numerous acid-fact bacilli were found in histologic examination of the resected eye. This case was thought to be miliary tuberculosis disseminated from intraocular tuberculosis. After 2 months of therapy, neurologic symptoms which might be caused by brain tuberucloma appeared and deteriorated rapidly. But by adding corticosteroid to antituberculous therapy, symptoms were diminished gradually.

Anti-Inflammatory Agents↗
PubMed1998

Evaluation of Roche Amplicor PCR assay for Mycobacterium avium complex in bronchial washing.

SETTING: A commercially available polymerase chain reaction (PCR) test (Roche AmplicorTM Mycobacterium avium and M. intracellulare assay-MAC-PCR) designed to detect M. avium complex (MAC) in bronchial washing was evaluated. DESIGN: A total of 141 specimens from 127 patients with various pulmonary conditions were examined. Results were compared with acid-fast smears, cultures with Ogawa egg medium, as is still commonly used in Japan, and final diagnoses. RESULTS AND CONCLUSIONS: A total of 14 bronchial washing specimens yielded MAC. Six smear- and culture-positive specimens were all MAC-PCR positive. In eight smear-negative and culture-positive specimens, six were MAC-PCR positive. The overall sensitivity versus culture was 85.7% (12/14). However, sensitivity might be over-estimated, as there is a lower recovery rate of MAC with egg-based medium compared with liquid media. In 127 patients, 15 were identified as having pulmonary MAC disease, of whom 13 had positive MAC-PCR in bronchial washing. In the remaining 112 patients, MAC-PCR was negative, which suggests that positive MAC-PCR was not a contaminated result. However, in terms of sensitivity and speed, we were unable to show any additional clinical benefit for using MAC-PCR as opposed to liquid media, in which MAC can frequently be detected in 7 to 14 days.

Adult↗
PubMed1998

[Clinical features and diagnosis of disease caused by nontuberculous mycobacteria].

Number of patients infected with nontuberculous mycobacteria (NTM) is increasing world-wide in recent years. In Japan, M. avium complex, M. kansasii and rapidly growing mycobacteria account for most of the pathogens. They cause chronic and indolent pulmonary infection, lymphadenitis, disseminated diseases especially in patients with AIDS and localized skin, soft tissue, and skeletal infection. Because clinical features of NTM are not discernible from those of M. tuberculosis and NTM are ubiquitous in our environment, isolation and identification of the bacilli are mandatory for the diagnosis, and several diagnostic criteria are put forth.

Humans↗
PubMed1997

Lipopolysaccharide-binding proteins and their involvement in the bacterial clearance from the hemolymph of the silkworm Bombyx mori.

Proteins having the ability to bind to Escherichia coli K12W3110 (rough (R) mutant) were isolated and purified by affinity precipitation from the larval hemolymph of the silkworm Bombyx mori. These proteins were found to consist of two components with molecular masses of 43 kDa and 40 kDa by SDS/PAGE. They bound to all E. coli R mutants (Ra, Rb1, Rc, Rd1 and Re) and Salmonella minnesota R mutants. However, they did not bind to smooth types of the above bacteria. They bound to both lipopolysaccharide(LPS)-coated and lipid-A-coated microtiter plates and have similar dissociation constants for LPS and lipid A. This indicates that the binding proteins recognize the lipid A portion of LPS and thus, we have named these proteins BmLBP (B. mori LPS-binding proteins). We also found that BmLBP participated in the clearance of E. coli cells injected into the body cavity of the silkworm.

Acute-Phase Proteins↗
PubMed1997

Forensic analysis of eleven cyclic antidepressants in human biological samples using a new reversed-phase chromatographic column of 2 microm porous microspherical silica gel.

A high-performance liquid chromatographic method has been developed for the forensic analysis of eleven frequently used cyclic antidepressant drugs (ADSs) (amitriptyline, amoxapine, clomipramine, desipramine, dosulepine, doxepin, imipramine, maprotiline, melitracen, mianserine and nortriptyline) using a recently developed reversed-phase column with 2 microm particles for the analysis of biological samples. The separation was carried out using two different C8 reversed-phase columns (column 1: 100 mm X 4.6 mm I.D., particle size 2 microm, TSK gel Super-Octyl; column 2: 100 mm X 4.6 mm I.D., particle size 5 microm, Hypersil MOS-C8) for comparison. The mobile phase was composed of methanol-20 mM KH2PO4 (pH 7) (60:40, v/v) and the flow-rate was 0.6 ml/min for both columns. The absorbance of the eluent was monitored at 254 nm. When the eleven drugs were determined, the sensitivity with the 2 microm particles was about five times greater than with the 5 microm particles. Retention times on column 1 were shorter than those on column 2. These results show that the new ODS column packing with a particle size of 2 microm gives higher sensitivity and a shorter analysis time than the conventional ODS column packing when applied to the analysis of biological samples.

Antidepressive Agents, Tricyclic↗
PubMed1997

Use of synchrotron radiation microangiography to assess development of small collateral arteries in a rat model of hindlimb ischemia.

BACKGROUND: Current methods of angiography cannot provide images of arteries measuring < 200 microns in diameter. We have recently developed a new angiography system that uses monochromatic synchrotron radiation and a high-definition video system with a spatial resolution of 30 microns. In the present study, we applied this microangiography system to visualize small arteries in normal and ischemic rat limbs and investigated the development of collateral arteries. METHODS AND RESULTS: Microangiography was performed in the normal and the ischemic limb 4 weeks after the excision of the femoral artery. In the normal limb, up to the fourth branches of the iliac and/or femoral arteries (diameter < 100 microns) were readily identified. Some of these branches were found to perfuse the distal thigh area. In the ischemic limb, an extensive structural remodeling of the vascular network was observed. Numerous small arteries had developed from the branches of the iliac artery to constitute a fine arterial network, the so-called "midzone," which was composed of linear, normal appearing arteries and those with an undulating, unbranched appearance. CONCLUSIONS: The small collateral artery network was angiographically visualized with a resolution limit < 100 microns. The linear collaterals appeared to result from an opening of preexisting vessels. The undulating, unbranched vessels were not observed in the normal limbs and seemed to be vessels that were newly formed after limb ischemia. Synchrotron radiation microangiography appears to be a powerful means of assessing the development of small collateral arteries, which may help to provide a basis for understanding of the collateral circulation.

Angiography↗
PubMed1997

Forensic analysis of 10 barbiturates in human biological samples using a new reversed-phase chromatographic column packed with 2-micrometre porous microspherical silica-gel.

A high-performance liquid chromatographic method has been developed for the forensic analysis of 10 frequently used barbiturates (BARs) (allobarbital, amobarbital, barbital, cyclobarbital, hexobarbital, metharbital, pentobarbital, phenobarbital, secobarbital and thiopental) using a recently developed reversed-phase column packed with 2-micron particles. The results show that the new ODS column packing gives higher sensitivity and a shorter analysis time than the conventional ODS column packing when applied to the analysis of biological samples.

Autopsy↗
PubMed1997

Simultaneous determination of carbamazepine and its metabolites in plasma from carbon tetrachloride-intoxicated rats using a new reversed-phase chromatographic column of 2-microns porous microspherical silica gel.

A high-performance liquid chromatographic method has been developed for the simultaneous analysis of carbamazepine (CBZ) and its two metabolites, carbamazepine-10,11-epoxide (CBZ-E) and carbamazepine-10,11-dihydroxide (CBZ-diOH), using a recently developed reversed-phase column with 2-microns particles and a 2-microliters microflow cell equipped with a UV detector. The separation was achieved using two different C18 reversed-phase columns (column 1: 100 x 4.6 mm I.D., particle size 2 microns, TSK gel Super-ODS; column 2: 100 x 4.6 mm I.D., particle size 5 microns, Hypersil ODS-C18) for comparison. The mobile phase was composed of methanol-water (30:70, v/v), and the flow-rate was 0.4 ml/min for both columns. The absorbance of the eluent was monitored at 210 nm. Retention times with column 1 were shorter than with column 2. When the three compounds were determined, the sensitivity and limit of quantification were about ten times better with column 1 than with column 2. The relative recovery and linearity with column 1 were approximately the same as those with column 2. These results show that the new ODS column packing with a particle size of 2 microns gives a higher sensitivity and shorter analysis time than the conventional ODS column packing.

Animals↗
PubMed1997

Reevaluation of postoperative radiotherapy for thoracic esophageal carcinoma.

PURPOSE: To reevaluate postoperative radiotherapy for thoracic esophageal carcinoma. METHODS AND MATERIALS: Reviewed were the outcome of 89 patients who underwent esophagectomy with systematic dissection of regional lymph nodes between 1988 and 1993. Of the 89 patients, 19 underwent no adjuvant treatment, 22 underwent adjuvant chemotherapy alone, and 48 underwent postoperative radiotherapy. Twelve of the 48 also underwent adjuvant chemotherapy. RESULTS: All patients who experienced local-regional recurrence had lymph node metastases at the time of surgery. The actuarial local-regional control rate at 2-year of follow-up was 94% for patients with lymph node metastases at the time of surgery who underwent postoperative radiotherapy alone or plus chemotherapy, and 74% for those who underwent adjuvant chemotherapy alone. The local-regional control rate was significantly better for those who had undergone postoperative radiotherapy (p < 0.01). CONCLUSIONS: Postoperative radiotherapy still plays an important role as adjuvant treatment.

Adult↗
PubMed1997

Humoral immune response to the E2 protein of hepatitis G virus is associated with long-term recovery from infection and reveals a high frequency of hepatitis G virus exposure among healthy blood donors.

The second envelope protein (E2) of the hepatitis G virus (HGV) was expressed in Chinese hamster ovary (CHO) cells and showed a molecular weight of approximately 60 to 70 kd, with 15 to 25 kd of the size contributed by N-linked glycosylation. An enzyme-linked immunosorbent assay (ELISA) using HGV-E2 was developed to test for antibodies to this protein (anti-E2) in human sera. High sensitivity was achieved by developing monoclonal antibodies (mAbs) to HGV-E2, which were used as capture antibodies in the ELISA. Our studies revealed that 16% of healthy Spanish blood donors were exposed to HGV, indicating that additional routes of viral transmission besides parenteral exposure might exist. An even higher prevalence of exposure to HGV (52%-73%) was found in several groups at risk of parenteral exposure to infectious agents, i.e., intravenous drug users, transfusion history, hemophiliacs, and hepatitis C virus (HCV)-positive patients. Most anti-E2-positive patients were HGV-RNA-negative and vice versa, indicating an inverse correlation of these two viral markers. A panel of 16 posttransfusion patients followed for up to 16 years revealed that patients who develop an anti-E2 response become HGV-RNA-negative, while patients who do not develop anti-E2 are persistently infected. Immunity to HGV seems to be long-lasting, because circulating antibody to E2 could still be detected 14 years after seroconversion. Sequence comparisons showed that E2 is highly conserved among isolates collected worldwide, indicating that immune escape variants are not common in HGV infections. This reflects on a molecular level why HGV infections usually are cleared spontaneously by the host. However, possible mechanisms of HGV persistence, as found in some patients, remain to be elucidated.

Amino Acid Sequence↗
PubMed1997

Lack of correlation between gallbladder opacification in delayed CT and contrast-associated nephropathy.

The objective of our study was to determine the correlation between gallbladder opacification by delayed CT and contrast-associated nephropathy (CAN). Delayed CT after angiography was performed in 269 patients. Gallbladder opacification was defined when the CT value in gallbladder was more than 30 HU. Positive renal dysfunction was recognized as CAN which defined as an increase in serum creatinine level > 0.3 mg/dl and > 20 % on days 1, 3, or 7. Gallbladder opacification appeared in 154 of 269 (57 %) patients and CAN in 35 (13 %) patients. Of 117 patients without gallbladder opacification, 17 CAN (14 %) were recognized, and of 152 patients with gallbladder opacification, 18 CAN (12 %) were recognized. No significant correlation existed between delayed gallbladder opacification and CAN.

Angiography↗
PubMed1997

Microangiographic assessment of collateral vessel formation following direct gene transfer of vascular endothelial growth factor in rats.

OBJECTIVE: The development of collateral microvessels following therapeutic angiogenesis with vascular endothelial growth factor (VEGF) was investigated using a new system of microangiography that employs monochromatic synchrotron radiation (SR) and a high definition video system to visualize arteries with a spatial resolution of 30 microns. METHODS: Ischemia was induced in the hindlimb of 20 rats by excision of the femoral artery, followed by transfection of the plasmid (400 micrograms) encoding VEGF or beta-galactosidase (control) into limb muscles. Microangiography was used to assess the development of collaterals in the ischemic limb four weeks after treatment. RESULTS: Gene transfer of VEGF produced morphologically similar, but significantly more extensive, collateral networks at the microvascular level as compared with the naturally occurring collateral arteries in the control animals (angiographic score: 0.88 +/- 0.08 versus 0.54 +/- 0.05, p < 0.01). No adverse vascular effects such as hemangiomas and/or arteriovenous (AV) fistulae were observed following VEGF treatment. The vasodilator effect of papaverine was evident in relatively large vessels in both groups. At the microvascular level (diameter < 100 microns), however, papaverine induced significant vasodilation in the VEGF-treated animals, and almost no vasodilation in the controls. CONCLUSIONS: SR microangiography allowed us to assess the development of small collateral arteries following VEGF-gene transfer. The information obtained may provide new insights regarding the collateral microcirculation and therapeutic angiogenesis.

Angiography↗
PubMed1997

Coronary vasoconstrictive effects of neuropeptide Y and their modulation by the ATP-sensitive potassium channel in anesthetized dogs.

OBJECTIVES: This study examined the coronary vasoconstrictive action of endogenous neuropeptide Y (NPY) during sympathetic nerve stimulation and its modulation by the adenosine triphosphate (ATP)-sensitive potassium (KATP) channel in vivo. BACKGROUND: Exogenous NPY was characterized by its potent vasoconstrictive effect. However, endogenous NPY has failed to show any vasoconstrictive activity in vivo. METHODS: We studied 70 anesthetized dogs with vagotomy under beta-adrenergic blockade. Ansae subclaviae stimulation and intracoronary administration of the neurotransmitters (NPY and norepinephrine) were done with or without alpha-adrenergic blockade, NPY antagonist BIBP3226 or KATP channel acting agents. We measured coronary vascular resistance (CVR) and the neurotransmitter levels in systemic arteries and the great cardiac vein, and the amount of overflow (venoarterial difference times myocardial blood flow). RESULTS: During nerve stimulation, NPY levels correlated significantly with CVR at the highest r value (r = 0.850, p < 0.0001) obtained for the venous level under alpha-blockade, but norepinephrine showed no correlation. Treatment with BIBP3226 abolished the correlation between NPY level and CVR under alpha-blockade. Without alpha-blockade, norepinephrine levels correlated significantly with CVR; however, NPY showed no correlation. The amount of NPY overflow during the stimulation was nearly 1,000-fold lower than norepinephrine overflow. Exogenous NPY had a 100-fold more potent coronary vasoconstrictive action than that of norepinephrine. The KATP channel antagonist glibenclamide enhanced vasoconstriction of NPY, and the agonist pinacidil suppressed it with a predominant effect in the subepicardial region. CONCLUSIONS: During sympathetic nerve stimulation, the vasoconstrictive actions of NPY are masked by norepinephrine under intact alpha-adrenoceptor conditions, manifest during alpha-blockade and modulated by KATP channel activity.

Adenosine Triphosphate↗
PubMed1997

In vivo function tests of hepatic drug-oxidizing capacity in patients with liver disease.

Aminopyrine, antipyrine and trimethadione have been widely used for some time as probe drugs to assess non-selective P450 liver function. They have proved useful in evaluating pre- and post-operative liver function when performing surgery, transplantations, etc., in addition to a general evaluation of liver function and drug interactions. Progress has recently been made both in these non-selective P450 function tests and in the analysis of drug-metabolizing enzymes at a molecular level, which has resulted in more selective P450 function tests. The caffeine (CYP1 A2), chlorzoxazone (CYP2E1), lidocaine (CYP3 A) and midazolam (CYP3 A) function tests and the erythromycin breath test (CYP3 A) are currently being used as specific probes. The future use of these tests needs to be discussed in terms of potential clinical implications.

Aminopyrine↗