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Biomedical subjects

K Takatori

Publications and source records attributed to K Takatori.

At least 37 records · Page 2Linked to original sources
PubMed1998

Screening system for urease inhibitors using 13C-NMR.

Urease inhibitors are candidate drugs to treat infection with the human pathogen, Helicobacter pylori, which produces a potent urease [urea amidohydrolase; EC 3.5.1.5]. We developed a screening system based on 13C-NMR measurement of the time course of decrease in the signal of 13C-urea in the presence of urease. The effect on urease activity of known inhibitors, hydroxamic acids, L-ascorbic acid, 2,2'-dipyridyl disulfide and ninhydrin, was speedily and conveniently measured by this method.

Binding, Competitive↗
PubMed1998

[Percutaneous ethanol injection for unresectable pancreatic cancer-report of two cases].

Two cases of unresectable pancreatic cancer underwent percutaneous ethanol injection (PEI). The first was a 65-year-old man with a 43 x 39 mm mass in the head of the pancreas. He received PEI (total 38.5 ml of ethanol) 6 times. Serum CA19-9 decreased from 3,800 U/ml to 1,700 U/ml. The patient was dead 6 months after PEI. Autopsy revealed coagulative necrosis at the site of ethanol injection. The second case was a 66-year-old man with a 70 x 50 mm mass in the body of the pancreas. He was treated by PEI (total 10 ml). After PEI, his abdominal pain was relieved considerably. He died 4 months after PEI treatment. These findings suggest that PEI may be useful not only for pain control but also for tumor reduction of unresectable pancreatic cancer.

Aged↗
PubMed1997

Validity of the 13-C-urea breath test for the diagnosis of Helicobacter pylori infection.

Infection with Helicobacter pylori (H. pylori) plays an important role in the pathogenesis of gastritis, peptic ulcer and gastric cancer, and the 13C-urea breath test (13C-UBT) is a convenient and non-invasive method for the detection of H. pylori in the stomach. We have examined the sensitivity, specificity and accuracy of 13C-UBT. The 13CO2/12CO2 ratio was measured using infrared spectroscopy (IR) and gas chromatography/mass spectrometry (GC-MS).

Breath Tests↗
PubMed1996

Pathomorphological findings in a case of onychomycosis of a racehorse.

The hooves of a racehorse which were affected with white line disease and hoof wall disorders on both forelimbs were histopathologically investigated using thin ground section and standard paraffin section techniques. On both hooves, large quantities of fungus were found to have invaded the white line tissues, especially in the terminal horn which were markedly damaged. The fungus was also present among the cellular debris in the fissures of horny tissues. The morphological characteristics of the fungus were brown (its natural color), PAS-positive, mold-like shape with septa inside the tissues, and unicellular spores outside the tissues. These findings suggest that onychomycosis was a primary and/or secondary cause of white line disease in this subject.

Animals↗
PubMed1996

Simple 13C-urea breath test with infra-red spectrophotometer.

When mass spectrophotometric analysis is used for the 13C-urea breath test to assess H. pylori infection, it is costly, complicated, and time-consuming. To overcome these disadvantages, we utilized an infra-red spectrophotometer as a substitute for the mass spectrophotometer. A total of 153 patients (181 tests) analyzed with peptic ulcers or non-ulcer dyspepsia were investigated. Breath samples were collected 15 min after ingestion of 13C-urea (100 mg in 30 ml water). An infra-red spectrophotometer was used to determine the concentration of 13CO2 in the expirate. The 13CO2/12CO2 ratio was also measured by mass spectrophotometry to compare results with those of infra-red spectrophotometric analysis. Direct detection of H. pylori was qualified in biopsy specimens. Of the 181 biopsies, 138 were positive for H. pylori infection and 43 were negative. With the urea breath test, the mean value in the positive group was significantly higher than that in the negative group (0.062 +/- 0.044 vs 0.011 +/- 0.014, respectively). The cut-off level, 0.01, was determined as delta 13C atom %. The sensitivity of infra-red spectrophotometry was 97.8% (135/138) and specificity was 74.4% (32/43). There was an extremely high coefficient of correlation (r = 0.996) between mass and infra-red photometric analysis. Infra-red spectrometry appears to have great potential not only for diagnosing H. pylori infection but also for assessing treatment results. Its advantages include technical simplicity, cost-effectiveness, and high accuracy.

Breath Tests↗
PubMed1995

[Pharmacological study on the dry distillation tar of delipidated soybean (Glyteer) (5): Antimicrobial activity].

Glyteer (GL) possessed a broad antimicrobial spectra against bacteria and fungi. The antimicrobial activity of GL was bactericidal action, but not bacteriostatic action. GL was more effective against fungi than bacteria. GL ointment also showed antimicrobial activity equal to that of GL. Furthermore, GL had an effect on methicillin-resistant Staphylococcus aureus (MRSA). Resistance to GL was not induced in broth cultures of Escherichia coli, Staphylococcus aureus, Streptococcus pyogenes, Candida albicans, and Trichophyton mentagrophytes. These results suggest that GL applied externally exerts a potent effect as an anti-microbial drug for dermopathy with various microbialpathogens.

Bacteria↗
PubMed1994

Adaptation of Aspergillus niger to several antifungal agents.

Adaptation of Aspergillus niger to short-term stress induced by three antifungal agents [amphotericin B (AMPH), miconazole (MCZ), and ketoconazole (KCZ)] was observed and evaluated quantitatively using individual hyphae. Spores were inoculated onto a poly-L-lysine-coated glass plate making up the base of a culture vessel. Potato dextrose broth (PDB) was added and the vessel incubated for 24 h at 28 degrees C. The growth rate of an arbitrarily selected test hypha was measured automatically. Exposure to AMPH (0.075 micrograms ml-1) stopped the growth of the hypha. After washing with PDB, the same concentration of AMPH was applied again. The growth of the test hypha was not inhibited. This phenomenon was defined as adaptation to the short-term stress of AMPH. Similarly, adaptation was observed with MCZ (0.01 microgram ml-1) and KCZ (0.5 microgram ml-1). The time required for the test hypha to restart growth after washing with PDB depended upon the concentration of MCZ or KCZ, but not upon the concentration of AMPH.

Adaptation, Physiological↗
PubMed1994

[Painful muscle cramps in liver cirrhosis and effects of oral taurine administration].

We administered 3 g of taurine orally for four weeks to 35 patients suffering from liver cirrhosis with repeated muscle cramp (MC). Improvement of MC was noted in 22 cases (62.9%). We also determined the plasma taurine concentration in eight cases of liver cirrhosis with MC. The plasma taurine concentration before ingestion was 54.1 +/- 20.7 nmol/ml, whereas that of four weeks after ingestion was 125.1 +/- 59.1 nmol/ml, which was significantly elevated by 2.3 fold. As the concentration increased, the frequency of MC decreased, suggesting the good correlation between ingestion and the decrease in frequency of MC. In liver cirrhosis without MC the plasma taurine concentration was 81.0 +/- 16.7 nmol/ml, which was significantly higher than in liver cirrhosis with MC. In a few cases with taurine ingestion, serial plasma taurine concentrations were detected. Plasma taurine reached the peak value during the first week of ingestion and plasma taurine levels were maintained 2-5 fold higher during ingestion.

Administration, Oral↗
PubMed1994

[Airborne fungi during the last ten years in Sagamihara].

Airborne fungi have been surveyed every week during the 10 years from 1983 to 1992 in Sagamihara. This is a follow up of a 1970 and a 1980 survey at the same sampling station (19.5 m above the ground), using the same gravity potato dextrose agar plate. There were two peak seasons during tsuyu (rainy season; June) and autumn (September to October). The most predominant fungi found, except for yeasts and non-sporulated fungi, were Cladosporium (2 seasons) and Alternaria (more frequently in tsuyu). These were followed by Epicoccum (tsuyu), Aureobasidium, Curvularia (summer), Ulocladium (autumn), Penicillium, Arthrinium, Nigrospora (summer), Fusarium, Trichoderma, Pestalotia in decreasing order of their total frequency throughout the 10 years. The most common fungi found during the most years were different from those found during 1970, particularly in the frequency of Aspergillus and Penicillium, but similar to those during 1980 in Sagamihara as well as in most areas of Japan.

Air Microbiology↗
PubMed1993

Automatic evaluation of antifungal volatile compounds on the basis of the dynamic growth process of a single hypha.

An automatic analysing system was developed and employed for the evaluation of antifungal activity of volatile compounds in the gas phase. Aspergillus niger was inoculated on agar medium in the reaction vessel. The reaction vessel was incubated at 28 degrees C for 24 h and then a volatile compound was introduced into the vessel either in a batch or flow manner. The antifungal activity of the respective compounds estimated in situ was expressed by the dynamic response parameters of a single hypha. All volatiles tested in the present system inhibited hyphal growth, except linalyl acetate: Limone and geraniol were the most inhibitory. In contrast, linalyl acetate promoted hyphal growth. By definition of the parameters, the fungicidal and fungistatic effects could be distinguished.

Antifungal Agents↗
PubMed1993

Determination of anti-Aspergillus activity of antifungal agents based on the dynamic growth rate of a single hypha.

The dynamic growth rate of a single hypha of Aspergillus niger was analysed using an automatic system. A colony of A. niger was in contact with saline, saline containing an antifungal agent, and flushing saline, in sequence. The growth rate of a test hypha selected arbitrarily from the colony responded dynamically to the antifungal agent. The minimum concentration that caused the complete inhibition of hyphal growth was defined as the minimum inhibitory concentration (MIC). The MIC values obtained were compared with those determined by conventional methods based on increasing rate of colony diameter or dry matter weight.

Amphotericin B↗
PubMed1993

Effects of antimycotics on the biosynthesis of cellular macromolecules in Aspergillus niger protoplasts.

The effects of nine antimycotics on the biosynthesis of cellular macromolecules were analyzed using the regenerating system of protoplasts of Aspergillus niger. The incorporation of several specific radioactive precursors into major cellular components were measured in the presence or in the absence of respective agents. Miconazole, ketoconazole, and tolnaftate inhibited the lipid synthesis. 5-Fluorocytosine strongly inhibited the DNA and protein syntheses. Griseofulvin, however, specifically inhibited the synthesis of cell wall polysaccharides, i.e. chitin and glucan. Other agents showed non-specific inhibition effects. The significance of morphological change of hypha as an indicator of antimycotic action and its feasibility as a screening tool for novel antimycotic compounds are discussed.

Antifungal Agents↗
PubMed1993

Isolation of Trichophyton verrucosum from lesional and non-lesional skin in calves.

Trichophyton verrucosum, a causative agent of bovine dermatophytosis in Japan is considered to transfer easily from infected cattle to other healthy ones. No studies have ever tried to elucidate the distribution of T. verrucosum in breeding environment. In this study, we investigated the distribution of T. verrucosum in infected young calf skin and healthy skin. Hairs or scale samples were collected from 29 lesional skin, and 46 non-lesional skin of the 19 and 34 infected calves, respectively, both varying in age 2 to 6 months old, and 35 hair samples from the 29 healthy ones. They were directly inoculated on medium. The detection rates of T. verrucosum-positive were 58.6% from the lesional parts, 34.8% from the non-lesional parts and 17.1% from the healthy parts. The isolation of T. verrucosum from the calves with no skin lesion due to dermatophytosis implied that this infection might be easily transmitted by the contact with the infected calves. T. verrucosum infection in cattle poses a serious problem in animal husbandry. It is also important for public health to take preventive measures against the infection.

Animals↗
PubMed1993

Revised structure of a delta-aminolevulinic acid derivative.

The structure of the fluorescent derivative formed in the method of Okayama et al. (Clin Chem 1990; 36:1494-7) for determining delta-aminolevulinic acid (ALA) concentrations was reinvestigated after esterification. The molecular ion peak at m/z 303.1473 corresponded to the molecular formula of C17H21NO4 (calcd 303.1470). The infrared spectrum showed the presence of carbonyl and carboxyl groups. This compound contained two acetyl groups, two methyl groups, and one methoxycarbonylethyl group, as revealed by 1H and 13C nuclear magnetic resonance and 13C-1H shift-correlated spectroscopy. Experiments with correlation spectroscopy via long-range coupling indicated that the main skeleton is 3H-pyrrolizine. The relative arrangement of functional groups was determined by means of nuclear Overhauser effect difference experiments. We were led to the conclusion that the methyl ester of the derivative is 2,6-diacetyl-1,5-dimethyl-7-(2-methoxycarbonylethyl)-3H-pyrrolizine. This structure was unequivocally confirmed by x-ray analysis; therefore, the structure of the derivative itself is 2,6-diacetyl-1,5-dimethyl-7-(2-carboxyethyl)-3H-pyrrolizine.

Chromatography, High Pressure Liquid↗
PubMed1992

Evaluation of antifungal activity of antimycotics by automatic analyzing system.

Antifungal activity of several antimycotics has been evaluated using an automatic analyzing system (AAS), which is composed of a specially designed reaction vessel, microscopic observation system, image analyzing system, and computer program for automatic tracing of hypha growth. The agar plate was prepared on the ceiling of the reaction vessel, and spore mass of a fungus (Aspergillus niger) was inoculated onto it. After the preincubation at 28 degrees C for 24 h the reaction vessel was set on a microscope stage and connected to the liquid flow system. An appropriate hypha was selected for the measurement of growth process during the following steps: first contact with saline for 30 min for the adaptation, the second contact with same saline for 30 min, contact with saline containing an antimycotic substance for 60 min, and contact with flushing saline for 60 min. During a sequence of these steps, the apical tip of a growing hypha displayed on a TV monitor was followed automatically. The dynamic response of hypha to an agent was analyzed by several parameters. Morphological changes of the hypha caused by respective agents were recorded on VTR for further analysis. By using this system, the antifungal activity of antimycotics could be quantitatively determined within several hours.

Amphotericin B↗
PubMed1991

Computerized approach using autoradiography to quantify atrial natriuretic peptide receptors in the DOCA-salt hypertensive rat kidney.

The alteration of atrial natriuretic peptide (ANP) receptors was investigated in the kidney of deoxycorticosterone acetate (DOCA)-salt treated hypertensive rats. The absolute amount of renal ANP receptors was determined in a membrane homogenate binding study of rat whole kidneys. Administration of DOCA-salt led to a decrease in renal ANP receptors after 3 weeks (prehypertensive state) and 6 weeks (established hypertensive state) of treatment. In vitro macro-autoradiography (ARG) was then performed with [125I]ANP to localize and to quantitate specific renal ANP receptors. ARG revealed that specific ANP binding was distributed mainly over the renal cortex with the inner medulla next in frequency. Renal ANP receptors were therefore quantified over the cortex and the inner medulla using the computerized microdensitometry of ARG. A significant reduction in renal ANP receptors was observed in the DOCA-salt treated rats after 3 and 6 weeks of treatment with decrements observed in both the cortex and inner medulla. These alterations may be related to the pathophysiology of hypertension.

Animals↗
PubMed1991

[Mycological examination on skin surface of cynomolgus monkeys (Macaca fascicularis)].

Mycological examination on skin surface of 39 female and 35 male cynomolgus monkeys was carried out. Fungi were detected from 73 out of 74 subjects. Cladosporium was mostly predominant and the moderate predominant fungi were as follows: Acremonium, Curvularia, Arthrinium, Trichoderma, Stachybotrys, Emericella, Epicoccum, Pestalotia and Aureobasidium. However, dermatophytes or keratinophilic fungi were not isolated in this study.

Animals↗