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Biomedical subjects

T Katoh

Publications and source records attributed to T Katoh.

At least 397 records · Page 22Linked to original sources
PubMed1991

Allergic photocontact dermatitis due to suprofen. Photopatch testing and cross-reaction study.

We report 5 cases of photocontact dermatitis due to suprofen, a nonsteroidal anti-inflammatory drug introduced to the Japanese market in 1989, and available as a 1% ointment. The patients developed pruritic eczematous lesions after applying the ointment for from 2 weeks to 3 months. All 5 patients reacted positively to photopatch testing with ultraviolet A (UVA) and suprofen down to 0.1-0.01% pet., and 3 patients showed positive reactions with ultraviolet B (UVB) and suprofen down to 1.0-0.1%. Moreover, all patients showed a cross-reaction with tiaprofenic acid, which has a very similar chemical structure to suprofen. However, there was no cross-reaction between suprofen and ketoprofen. Prescribers should be aware of the existence of photocontact sensitivity due to these drugs.

Adolescent↗
PubMed1991

Glomerular stereospecific synthesis and hemodynamic actions of 8,9-epoxyeicosatrienoic acid in rat kidney.

Renal glomerular and cortical metabolism of endogenous arachidonic acid by cytochrome P-450 epoxygenase yields 8,9-, 11,12-, and 14,15-epoxyeicosatrienoic acids (EET). Using gas chromatography-mass spectrometry, we measured the synthesis of 8,9-EET from an endogenous pool of arachidonic acid in normal rat kidney. The (8S,9R) isomer was favored over the (8R,9S) isomer in a ratio (%) of 59 to 41 in isolated glomeruli and 68 to 32 in cortex tissue. (8S,9R)- but not (8R,9S)-EET elicited dose-dependent vasoconstriction on intrarenal administration in the euvolemic Munich-Wistar rat. Micropuncture measurements of glomerular dynamics revealed that (8S,9R)-EET increased afferent arteriolar resistance (RA) leading to reductions in single-nephron plasma flow rate (QA), net transcapillary hydraulic pressure difference (delta P), and consequently single-nephron glomerular filtration rate (SNGFR). There was no significant change in the value of the glomerular capillary ultrafiltration coefficient (Kf). In the presence of a cyclooxygenase inhibitor, indomethacin, the effects of 8,9-EET were reversed. RA fell leading to increases in QA and delta P, with resultant augmentation of SNGFR. Under these conditions, a modest reduction if Kf was noted. Thus (8S,9R)-EET is a stereoselective renal vasoconstrictor, preferentially generated over its optical isomer, (8R,9S)-EET, suggesting that it is biologically relevant and implying specific structural requirements for EET receptor activation. The principal mechanism of action of 8,9-EET is preglomerular vasoconstriction. The vasoconstrictor effect of 8,9-EET is CO dependent.

8,11,14-Eicosatrienoic Acid↗
PubMed1991

Enhancement of rat liver mitochondrial function by portal branch ligation secures subsequent extended hepatectomy.

We have examined the effects of portal branch ligation on liver mitochondrial function and on subsequent extended hepatectomy in rat. In the occluded lobes, mitochondrial function was depressed immediately after the ligation. In the unoccluded lobes, mitochondrial function was enhanced and reached the maximum two days after the ligation. This enhancement was associated with increases in the enzymic activities and subunit amounts of the energy-transducing complexes, and with increase in mitochondrial DNA content. The ligation improved both survival rate and mitochondrial redox state monitored by the ratio of acetoacetate to beta-hydroxybutyrate after hepatectomy. These results suggest that the enhancement of mitochondrial function by portal branch ligation fills the energy demand for liver regeneration.

Animals↗
PubMed1991

[Endoscopic ultrasonography in the assessment of invasive cardiac cancer].

The aim of this study was to assess the accuracy and limitation of Endoscopic ultrasonography (EUS) in the preoperative evaluation of the cardiac cancer (cancer in the area less than 2 cm from the esophago-gastric junction). EUS was preoperatively performed in 20 patients with cardiac cancer. These cases were visualized by the water immersion method and balloon contact method. The results were correlated with the histology of resected specimens. EUS was accurate in assessing the depth of tumor infiltration. Over all accuracy of EUS for cardiac cancer was 90%. Recognition of ultrasonographic patterns had enabled us to judge the mode of tumor infiltration whether expansive or infiltrative. Microscopical spread over 5 mm to the esophagus of the cardiac cancer could be detected by EUS. EUS was accurate in diagnosing thoracic lymph nodes (No. 110, 111, 112) metastasis of the cardiac cancer (accuracy 86%). EUS was valuable in the clinical diagnosis of the cardiac cancer.

Adult↗
PubMed1991

Changes in orientation of the major interlobar fissure in chronic liver diseases.

The orientation of the major interlobar fissure, as an indicator of right lobar atrophy, was evaluated using axial MR imaging in 64 patients with histologically proven chronic liver diseases. The "interlobar fissure angle" was determined by a line drawn through the middle hepatic vein and inferior vena cava and a horizontal line at the level of hepatic hilus. The angle was significantly smaller in cirrhosis than in either chronic persistent or active hepatitis. A much smaller angle was observed in cirrhosis associated with colonic interposition. The increasing incidence of small "interlobar fissure angle" (less than 30 degrees) was observed to parallel the histological stages from chronic persistent hepatitis to liver cirrhosis. All the cirrhotic patients with colonic interposition and an angle of less than 30 degrees. This simple method is considered useful in the diagnosis of right lobar atrophy and disease severity in chronic liver disease.

Adult↗
PubMed1991

Mechanism of adaptive increase of respiratory enzymes in rat liver mitochondria during obstructive jaundice.

In order to elucidate the response of mitochondria to obstructive jaundice, we have examined the effects of common bile duct ligation on rat liver mitochondria. Although oxidative phosphorylation, especially respiratory control, of mitochondria was disturbed after the ligation, specific enzymic activities and subunit contents of the respiratory enzymes in mitochondria were significantly increased one week after the ligation. The immunostain for ubiquinol-cytochrome c oxidoreductase confirmed the increase in the subunit amounts in hepatocytes. This increase was associated with the increase in specific contents of DNA in mitochondria. These results suggest that mitochondrial biosynthesis is stimulated during obstructive jaundice.

Animals↗
PubMed1991

[Stab wounds of the spinal cord by a kitchen knife: report of a case].

A case of spinal cord injury due to stab wounds by a kitchen knife is presented. A 41-year-old male was hospitalized because of spinal cord injury resulting from stab wounds inflicted with a kitchen knife in the posterior cervical area. Neurological examination on admission showed paraplegia, disappearance of deep tendon reflex in both lower extremities, sensory disturbance below T1 level, left Horner's syndrome and urinary disturbance. In addition to these symptoms cerebrospinal fluid was leaking from the wounds. An emergency operation was performed. After laminectomy of C7 and T1, we found that the spinal cord was almost completely split at C7/T1 level. Dural plasty was performed. Neurologically, sensory disturbance was slightly improved at 4 months after the injury. Initial MRI (TR: 200 msec, TE: 20 msec) revealed high intensity at C7/T1 level which was damaged by the kitchen knife. MRI 5 months after the injury revealed low intensity on T1 weighted imaged, high intensity on T2 and proton weighted image. The occurrence of the spinal cord injury due to stab wounds by a kitchen knife is very rare in Japan. MRI is useful in the diagnosis of stab wounds of the spinal cord.

Adult↗
PubMed1991

[Clinical significance of a tumor marker NCC-ST-439 in breast cancer--a comparative study with CA 15-3, CEA and TPA].

We compared a new tumor marker NCC-ST-439 (ST-439) with CA 15-3, CEA and TPA for its clinical usefulness in 600 patients with breast cancer (81, primary; 49, recurrent; 470, non-recurrent), and confirmed the following results. The sensitivity of ST-439 (41.5%) was significantly higher (p less than 0.05) than that of CA 15-3 (26.2%), CEA (28.5%) and TPA (26.9%). The specificity of ST-439 (84.5%), however, was considerably lower (p less than 0.01) than these other three markers. In primary cases, the positive rate of ST 439 (34.6%) was significantly higher (p less than 0.05) than that of the other markers, and was remarkable in the early stage. As to the positive rate at the various metastatic sites, there were a few differences among these four markers. Because of no significant correlation among these markers, combination assay with ST-439, CA 15-3 and CEA showed an excellent sensitivity (57.7%). These results suggest that ST-439 is a useful tumor marker not only in monitoring the recurrence, but also in the diagnosis of primary cancer.

Antigens, Tumor-Associated, Carbohydrate↗
PubMed1991

[A case of inflammatory breast cancer successfully treated with intra-arterial infusion of high-dose epirubicin].

A 56-year-old female with extensive inflammatory breast cancer was treated with intra-arterial infusion chemotherapy using a high dose of epirubicin. One cycle consisted of epirubicin; 150 mg (day 1, 4, 7) and daily administration of tamoxifen; 40 mg. After completion of 2 cycles of the regimen, both the main tumor and the extensive inflammatory skin lesion completely disappeared (CR). Hair loss, gastrointestinal disorders and leukopenia (nadir; 1,600) were the side effects encountered, but all of them were reversible. These findings suggested that dose-escalation of epirubicin was effective, and that cases with extensive skin involvement were also candidates for this modality.

Administration, Oral↗
PubMed1990

Isolation and characterization of human reg protein produced in Saccharomyces cerevisiae.

reg was originally identified as a gene expressed during the regeneration of insulin-producing pancreatic beta-cells of the rat. We built an expression vector containing human reg cDNA to drive Saccharomyces cerevisiae to synthesize the reg protein, and purified it from the culture medium. The 144-amino acid sequence of the recombinant protein was consistent with that deduced from the cDNA and genomic DNA sequence except that the signal sequence of 22 amino acids was eliminated, and the amino-terminal residue of the protein was pyroglutamic acid. The secondary structure of the reg protein was predicted by determination of the intramolecular cystine linkage and of alpha-helix and beta-sheet contents.

Amino Acid Sequence↗
PubMed1990

[Quantitative image of bone mineral content--dual energy subtraction in a single exposure].

A dual energy subtraction system was constructed on an experimental basis for the quantitative image of bone mineral content. The system consists of a radiography system and an image processor. Two radiograms were taken with dual x-ray energy in a single exposure using an x-ray beam dichromized by a tin filter. In this system, a film cassette was used where a low speed film-screen system, a copper filter and a high speed film-screen system were layered on top of each other. The images were read by a microdensitometer and processed by a personal computer. The image processing included the corrections of the film characteristics and heterogeneity in the x-ray field, and the dual energy subtraction in which the effect of the high energy component of the dichromized beam on the tube side image was corrected. In order to determine the accuracy of the system, experiments using wedge phantoms made of mixtures of epoxy resin and bone mineral-equivalent materials in various fractions were performed for various tube potentials and film processing conditions. The results indicated that the relative precision of the system was within +/- 4% and that the propagation of the film noise was within +/- 11 mg/cm2 for the 0.2 mm pixels. The results also indicated that the system response was independent of the tube potential and the film processing condition. The bone mineral weight in each phalanx of the freshly dissected hand of a rhesus monkey was measured by this system and compared with the ash weight. The results showed an error of +/- 10%, slightly larger than that of phantom experiments, which is probably due to the effect of fat and the variation of focus-object distance. The air kerma in free air at the object was approximately 0.5 mGy for one exposure. The results indicate that this system is applicable to clinical use and provides useful information for evaluating a time-course of localized bone disease.

Animals↗
PubMed1990

[Measurement of oxygen concentration in tumor cells by fluorescent probe (nitrocompound)].

The hypoxic cell fraction in tumors is considered to be responsible for radioresistance. Estimating the population of the hypoxic cell fraction in tumor could develop the effective means to predict radiosensitivity. In this study, nitroacridine (fluorescent dye) was tested to estimate hypoxic status in single cells and in spheroids. The oxygen concentration in the medium was measured by oxygen electrodes utilizing polarography method, mean while that in cells was calculated from the fluorescence intensity of the dye. The fluorescent spectra from cells showed the same pattern in spite of the changed oxygen concentration in medium, on the other hand its intensity was dependent upon the oxygen concentration. Using a fixed nitroacridine concentration and a fixed staining time, oxygen concentration of cells could be determined within range from 0.1 to 1.0% values. These values are almost the same as the oxygen concentration of the radioresistant tumor cells. Thus, the fluorescent method we used in this study is considered to be useful to estimate radioresistance of tumor. However, fluorescent intensity would alter when used different cell lines, because of different cellular activity of nitroreductase.

Aminacrine↗
PubMed1990

Translocation of protein kinase C to membranes induced by TNF does not cause the inhibition of EGF binding to human wish cells.

Tumor necrosis factor (TNF) caused an inhibition of 125I-labeled epidermal growth factor [( 125I]EGF) binding to its receptors of human amniotic (WISH) cells at 5 min after addition of TNF, which reached a maximal level (60-70% reduction) after 15-30 min and declined thereafter. TNF also induced a translocation of protein kinase C activity from the cytosol to the membrane, which peaked at 45-60 min after addition of TNF and almost returned to basal level at 120 min. Furthermore, prolonged incubation of WISH cells with 12-O-tetradecanoylphorbol 13 acetate (TPA) diminished the TPA effect on the inhibition of EGF binding to the cells due to the desensitization of protein kinase C; however, TNF still reduced the EGF binding to the cells pretreated with TPA for a long time. These results indicate that although TNF causes the translocation of protein kinase C to the membrane, activation of protein kinase C is not required for TNF to induce a decrease in EGF binding to the cells.

Amnion↗
PubMed1990

A passive tobacco smoke exposure system for laboratory animals.

A simple passive tobacco smoke exposure system was developed for laboratory animals. The system consisted of a tobacco smoke generator and an exposure chamber. Performance testing was conducted using Fischer 344 rats. The rats were exposed to passive tobacco smoke generated by 20 cigarettes per day for 3 months. The concentration of the cigarette smoke aerosol (particle phase) in the chamber can be kept almost constant during exposure. The daily average mass concentration was 10.0 +/- 4.3 mg/m3 and the carbon monoxide was 79 +/- 22 ppm during exposure.

Animals↗