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Biomedical subjects

N Takeuchi

Publications and source records attributed to N Takeuchi.

At least 109 records · Page 6Linked to original sources
PubMed1995

[Activities of antipseudomonal agents against clinical isolates of Pseudomonas aeruginosa].

Using clinically isolated 114 strains of Pseudomonas aeruginosa that were collected from April to October 1994, activity of antipseudomonal agents against these organisms was determined using the method of liquid microdilution. In addition, antimicrobial activities of the agents were graded according to serological groups of organisms. The results of this study are summarized as follows. 1. Many strains of P. aeruginosa were isolated mainly from sputum, pus and urine. 2. Serological group G organisms of sputum origin, group I of pus and bile origin, and group E of urine origin were isolated most frequently. 3. The most powerful antipseudomonal agent was cefclidin. Its MIC50 and MIC90 were 0.78 and 6.25 micrograms/ml, respectively. The second most powerful agent was ciprofloxacin whose MIC50 and MIC90 were 0.39 and 12.5 micrograms/ml, respectively. 4. The proportions of resistant strains ranged from 0.9% for cefclidin to 40.4% for ofloxacin. The antipseudomonal agents to which 30% or more of strains were resistant were cefpirome, gentamicin and ofloxacin. 5. Cefclidin showed the most powerful activity against strains that were resistant to ceftazidime, imipenem, gentamicin and ofloxacin. Its MIC90 against all strains resistant to ceftazidime, gentamicin and ofloxacin was 6.25 micrograms/ml. The MIC90 of cefclidin and tobramycin against imipenem-resistant strains was 3.13 micrograms/ml. 6. Group E organisms were found among strains resistant to ceftazidime, gentamicin and ofloxacin at high rates, but no group E strains were found among imipenem-resistant organisms. 7. Agents with highest activities by serological group of organisms were cefclidin against group A, tobramycin and ciprofloxacin against group B, imipenem against group E, ciprofloxacin against group G, and cefclidin and ciprofloxacin against group I.(ABSTRACT TRUNCATED AT 250 WORDS)

Anti-Infective Agents↗
PubMed1994

Isolation of mouse complement component C7.

Mouse complement component C7 was purified from serum by a sequential procedure of fractionation precipitation by ammonium sulfate, followed by DE-52 anion exchange chromatography. Protein G affinity column chromatography, Mono S cation exchange chromatography and Superdex 200 gel filtration. The final product contained a highly purified mouse C7 component showing a single band on SDS-PAGE at the apparent Mrs of 90 kDa and 100 kDa under non-reduced and reduced conditions respectively. The yield of C7, which was measured by the biological activity, was 7.0%

Animals↗
PubMed1994

Heme-heme oxygenase complex: structure and properties of the catalytic site from resonance Raman scattering.

The resonance Raman spectra of ferric and ferrous forms of the heme-heme oxygenase (HO) complex (isoform 1) clarify several structural features of the catalytic active site. Isotopic substitution studies of the central iron atom of the heme demonstrate that the line at 218 cm-1 in the ferrous ligand-free form of the complex originates from the iron-histidine stretching mode. The presence of a Raman line at this frequency confirms that the fifth ligand coordinating to the heme is a neutral imidazole from a histidine residue. The modes associated with CO in the carboxy derivative of the ferrous enzyme complex have typical frequencies of histidine-bound heme proteins such as myoglobin. In the ferric form of the complex, at alkaline pH, hydroxide is identified as the bound exogenous ligand, and at neutral pH we infer that water is bound. Thus, the coordination of the heme-HO complex is the same as that in myoglobin. However, in a comparison of the low-frequency vibrational modes in the resonance Raman spectrum of the heme-HO complex to those of myoglobin, the spectra are found to be very different, indicating that the interactions between the heme and its amino acid pocket in these two proteins are quite different. The neutral imidazole may play several important roles in the physiological function of the heme-HO complex.

Animals↗
PubMed1994

Endoluminal ultrasonography in the follow-up of patients with rectal cancer.

One principal aim in follow-up after curative surgery for colorectal cancer is to identify recurrent disease at an early and possibly treatable stage. The major problem for patients with rectal carcinoma is local recurrence, which occurs in 3-30 per cent of cases and carries a 5-year survival rate of less than 5 per cent. Since 1989, in addition to digital and sigmoidoscopic examination, endorectal ultrasonography has routinely been used in the follow-up of patients with rectal cancer. Sixty-six patients (40 men) who had undergone attempted radical surgery for mid- and lower-third rectal cancer were included in the study. The mean age was 68 (range 43-87) years. A total of 190 scans were performed, with a mean of 3 (range 1-9) for each patient. Thirteen (20 per cent) of the 66 patients developed local recurrence; in all cases this was suggested by rectal ultrasonography. Digital examination and rigid sigmoidoscopy failed to detect recurrence in three patients. Four detected recurrences were treated radically; the remaining patients received radiotherapy, palliative transanal resection or laser management because of advanced age or refusal to undergo surgery. Six patients were alive a mean of 21 (range 4-50) months after recurrence. Of these six patients, four were free from disease (three had undergone salvage surgery and one radiotherapy). Postoperative rectal ultrasonography can detect some local recurrences at an early treatable stage. The method is more accurate than digital examination and sigmoidoscopy, and should be used as part of a regular follow-up programme.

Adult↗
PubMed1994

Morphological changes in the tectorial and basilar membranes of aged rats.

Using both light and transmission electron microscopy presbycusic degeneration of the cochlea was observed in particular in the tectorial and basilar membranes, in naturally aged rats. These animals showed a descending auditory pattern as determined by auditory brainstem response. Ultrastructurally, the number of collagen fibers in the tectorial membrane was reduced and straight type A fibers were increased relative to branched, coiled type B fibers. The basilar membrane in the basal turn was also thickened by an increased homogeneous ground substance. These findings indicate that the specificity of vibration of the tectorial and basal membranes is very different in aged and young rats.

Aging↗
PubMed1994

Image quality of digital chest radiography: evaluation of subtle interstitial lung abnormalities (preliminary study).

To evaluate the image quality of storage phosphor radiography (SR) for diagnosing subtle interstitial lung abnormalities, we studied the differences between conventional screen-film radiography (FR) and SR in 38 patients. Nineteen patients had subtle interstitial lung abnormalities and the others had normal chests. Two formats of hard copies were used for SR; a full-size SR (14 x 14 inches, 0.2-mm pixel size) and a minified SR (9 x 9 inches, 0.13-mm pixel size). Readings were carried out by 14 readers (7 chest radiologists and 7 residents). The area under the receiver operating characteristic curve was used to evaluate the results. For the 14 readers no significant differences in observer performance were observed among the three image sets (FR, full-size SR, minified SR), while for the seven chest radiologists significant differences were observed between FR and the two formats of SR. The best perceptual accuracy was obtained with FR as evaluated by the seven chest radiologists. In conclusion, while overall performance with digital and conventional radiographs was almost the same as far as diagnosing subtle interstitial lung abnormalities, significant differences between FR and SR were found by chest radiologists. Critically important information may be lost in commercially available SR.

Humans↗
PubMed1994

High-resolution CT and pulmonary function tests in collagen vascular disease: comparison with idiopathic pulmonary fibrosis.

To estimate whether the lung abnormalities seen in collagen vascular diseases (CVD) were similar or distinct to those seen in idiopathic pulmonary fibrosis (IPF), and to ascertain whether the extent of the abnormalities on high-resolution CT (HRCT) correlated with pulmonary function, we reviewed HRCT findings and pulmonary function test results of 64 patients with either CVD (n = 55) or IPF (n = 9). Response to corticosteroid treatment was also evaluated in 20 of the 64. High incidence of honeycomb lesion was observed in IPF (9/9, 100%) and in progressive systemic sclerosis (PSS) (11/14, 79%). CVD, except for PSS, had a low incidence of honeycomb lesion (27%). On the other hand, incidence of ground-glass shadow in CVD (47/55, 85%) was the same as that in IPF (8/9, 89%). Diffusing capacity significantly correlated with the extent of all parenchymal abnormalities in all CVD and IPF, with honeycomb lesion in PSS, and with ground-glass shadow or air-space consolidation in CVD except for PSS (r < -0.7, P < 0.001). In all 15 cases in which corticosteroid therapy was effective, no honeycomb lesions were seen. Collagen vascular disease, except for PSS, had a different pattern of disease than IPF. The morphologic changes seen on HRCT correlated well with pulmonary function in CVD.

Collagen Diseases↗
PubMed1994

Preoperative embolization for paraganglioma.

We have applied a new method of preoperative embolization to an intravagal and to carotid body paraganglioma, using estrogen dissolved in absolute alcohol and polyvinyl alcohol particles, which diffusely embolizes vessels from capillaries to main feeders. Total resection of the tumors after embolization was successively performed without postoperative complications; total blood loss was 205 and 130 ml, respectively, and the surgical time was approximately 3 hours in both cases. The technique, characteristics, and advantages of this method are discussed.

Angiography↗
PubMed1994

Effect of beta-carotene on spontaneous and X-ray-induced chromosomal damage in bone marrow cells of mice.

The effect of beta-carotene on spontaneous and X-ray-induced chromosomal damage in bone marrow cells of mice was studied. As a source of beta-carotene, dried Dunaliella bardawil (containing 6% beta-carotene) or oil suspension of Dunaliella beta-carotene was used. In Experiment 1, mice were given a basal diet, a 0.5% Dunaliella diet, or a 4% Dunaliella diet for four weeks. In Experiment 2, mice were given an oil suspension of Dunaliella beta-carotene (300 mg/kg body wt) by gavage for seven days while being fed a fat-rich diet. After beta-carotene treatment for the indicated time, spontaneous and X-ray (0.3 Gy, whole-body)-induced chromosomal damage in bone marrow cells was evaluated in terms of the percentages of micronucleated reticulocytes in their peripheral blood. The beta-carotene treatment slightly lowered the spontaneous and X-ray-induced chromosomal damage in bone marrow cells. Despite the higher doses of beta-carotene, the concentrations of beta-carotene in bone marrow, liver, and serum were much lower than those of vitamin E. In addition, the beta-carotene treatment markedly lowered the concentration of vitamin E in the tissues.

Animals↗
PubMed1994

Role of membrane-associated lymphotoxin (mLT) in the killing activity of lymphokine-activated killer (LAK) cells towards various tumour cell lines.

Human lymphokine-activated killer (LAK) cells developed by an incubation of peripheral mononuclear cells with IL-2 express the membrane-associated lymphotoxin (LT)-related molecule (mLT). By a further cultivation of mLT expressing (mLT-positive) LAK cells for 24 h without IL-2, mLT disappears (mLT-negative LAK cells). Cytotoxicities of various tumour cell lines by either mLT-positive or -negative LAK cells were compared. Eight out of 12 tumour cell lines, less susceptible to mLT-negative LAK cells than mLT-positive LAK cells, were categorized as group A. Two tumour cells (K562 and Molt-4) had the same susceptibility to both kinds of LAK cells. The others (Daudi and Jurkat) had less susceptibilities only when they were assessed at E:T ratios of less than 5. The four tumour cell lines in the latter two cases, containing K562, Molt-4, Daudi and Jurkat cells, were categorized as group B. The cytotoxicities of group A tumour cells, but not group B tumour cells, by LAK cells were significantly suppressed by the presence of anti-LT antibody. Group A tumour cells had higher LT-binding ability (2.82-16.44 fmol/10(6) cells) than group B tumour cells (less than 1.46 fmol/10(6) cells). Both mLT-positive and -negative LAK cells had similar perforin activities and tumour cell-binding capacities. These results suggest that the mLT-mediated killing mechanism is involved in tumour cell killing by LAK cells. Further, various tumour cell lines can be classified into two large groups according to their susceptibilities to the mLT-mediated killing by LAK cells.

Animals↗
PubMed1994

Interpretation of subtle interstitial lung abnormalities: conventional versus film-digitized radiography.

PURPOSE: To evaluate the reliability of film-digitized radiography in detection of subtle interstitial lung abnormalities. MATERIALS AND METHODS: The differences in interpretation of conventional screen-film (SF) and film-digitized (FD) radiographs obtained in 80 patients were studied. Forty patients with subtle interstitial lung abnormalities and 40 patients with no lung abnormalities were selected. SF radiographs of all patients were digitized (spatial resolution, 0.175 mm; 2,000 x 2,000 pixels; 10 bits). Five chest radiologists and five residents evaluated the images with a five-level scale of confidence. Results were evaluated with receiver operating characteristic techniques. RESULTS: For the entire group, no statistically significant differences in performance were found between SF and FD radiographs. Chest radiologists performed better on SF radiographs (P = .003). For residents, no statistically significant differences were observed between the modalities. CONCLUSION: FD radiographs may be inadequate compared with SF radiographs in the diagnosis of subtle interstitial lung abnormalities.

Adult↗
PubMed1994

Extracorporeal shock wave lithotripsy using the Dornier MPL 9000 lithotriptor.

336 patients with urinary calculi were treated between June 1988 and October 1991 with extracorporeal shock wave lithotripsy using the Dornier MPL 9000 lithotriptor. Of 352 renal units (a kidney and its ureter), 286 had renal stones, 62 had ureteral stones and 10 had both. There were radiolucent stones in 6 units. The complete disintegration rate was 94%. The mean number of shock waves was 2,973, the range being from 300 to 16,131. In 310 of 447 (64%) sessions, treatment was done without any anesthesia. The rate of complete removal was 67.3% 3 months after the last treatment. Only 11 patients required supplementary treatment consisting of percutaneous nephrolithotripsy and transurethral lithotripsy. There were no severe complications except subcapsular hematomas observed in 2 patients. The Dornier MPL 9000 is a useful lithotriptor for the treatment of urinary calculi, except staghorn calculi.

Female↗