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Biomedical subjects

K Doi

Publications and source records attributed to K Doi.

At least 667 records · Page 37Linked to original sources
PubMed1988

Brain lesions induced by hypertonic saline in mice: dose and injection route and incidence of lesions.

A single injection of hypertonic saline produced brain lesions with corresponding nervous signs in mice. The lesions were most often found in the hippocampus and were characterized by degeneration and loss of pyramidal cells. They could be induced effectively by a single administration of 20 ml of 25% saline/kg orally or of 30 ml of 8.5% saline/kg intraperitoneally. This simple experimental system seems to be a useful model of central nervous system involvement.

Administration, Oral↗
PubMed1988

Behavioral characteristics in mice with brain lesions induced by hypertonic saline.

Behavioral and histopathological characteristics were studied in mice treated repeatedly with hypertonic saline. In passive avoidance response using a step-through-type shuttle box, the mice treated with hypertonic saline showed shorter latency than control mice. No changes were observed in active avoidance response using a two-way-type shuttle box, spontaneous motor activity or motor function. Histopathological examination revealed marked and frequent degeneration and loss of neurons in the hippocampus as compared with animals after single treatment. The animals with severe hippocampal lesions showed impairment of passive avoidance response. The present brain lesions resulting from repeated treatment with hypertonic saline in mice are considered to be a possible model for memory disorders caused by hippocampal lesions in humans.

Animals↗
PubMed1988

[Affiliative achievement motivation and non-affiliative achievement motivation of female students].

The purpose of this study was to investigate the two dimensional theory of achievement motivation (Doi, 1982) in female students. Doi's motivation scale were administered to 81 female university students, 58 female students of school of nursing and 77 female students of school of English Language, and the Yatabe-Guilford personality inventory was also administered to the first and the second groups. Affiliative achievement motivation and non-affiliative achievement motivation were extracted by principal component analyses and canonical correlation analyses. Non-affiliative achievement motivation was found to be related to personality type: emotional instability and introversion. These findings differ from achievement motivation concepts (Murray, 1938; McClelland, Atkinson, Clark, & Lowell, 1953), that include emotional stability and extraversion.

Achievement↗
PubMed1988

[An immunohistological study of metastatic adenocarcinoma of the lymph node: is it useful in diagnosing a primary tumor?].

An immuno-histological study of metastatic adenocarcinoma has revealed the following results. Metastatic adenocarcinomas of the lymph-node of pulmonary and colonic origin were positive for CEA and negative for lysozymes, and those from gastric, pancreatic, and gallbladder tumors were positive CEA and lysozymes, and those from gastric and pancreatic tumors were positive for the secretory component. The prostate specific antigen was exclusively positive for metastatic prostatic adenocarcinoma with a low frequency and prostate acid phosphatase had many false positive results. Thyroglobulin was found to be positive only to colloid. Lactalbumin showed no specificity to metastatic breast adenocarcinoma. For achieving the final diagnosis of a primary tumor, its location in lymph nodes, the clinical history and the results of other examinations must also be taken into consideration.

Adenocarcinoma↗
PubMed1988

Histopathology of BALB/c mice infected with the D variant of encephalomyocarditis virus.

BALB/c mice infected with 10(5) pfu of the D variant of encephalomyocarditis virus were examined histopathologically during the subacute stage of infection. Main pathologic changes were observed in the brain, heart (massive myocardial necrosis with subsequent organization (i.e., replacement of necrotic myocardium by connective tissue) and congestion and dilatation of the right ventricle) and pancreas (moderate degranulation of beta-cells resulting in elevation of blood glucose level). The brain lesions were found most frequently in the pyramidal layer of the hippocampus and the granular layer of the cerebellum and were characterized by degeneration of neurons containing virus antigens. Perivascular mononuclear cell infiltration, spreading to the adjacent brain tissue, and thrombosis in small vessels were also frequently seen. Focal loss of neurons and gliosis developed later in these lesions.

Animals↗
PubMed1988

Cervical laminoplasty (Hattori's method). Procedure and follow-up results.

Posterior decompression plus posterior reconstruction (laminoplasty) is a useful surgical method for treatment of cervical compressive myelopathy. There are many laminoplasty procedures. This paper describes the Z-shaped laminoplasty developed by Hattori in 1971, and presents a clinical follow-up of the authors' experience with 130 patients. The procedure involves grinding the laminae down with an air drill and making a Z-shaped cut into the thinned laminae without excising the laminae. This technique enlarges the spinal canal. The purpose of this technique is to decompress the spinal cord and at the same time maintain clinical stability. Postoperative results were satisfactory without any major complication. Follow-up study was conducted in 78 cases with a minimal follow-up period of more than 2 years. Satisfactory clinical results were maintained for long periods postoperatively, and the enlargement of the spinal canal was well maintained as demonstrated on follow up X-ray study.

Adult↗
PubMed1988

Computer-aided detection of microcalcifications in mammograms. Methodology and preliminary clinical study.

The authors investigated the feasibility of using computer methods for automated detection of clustered microcalcifications on clinical mammograms. A new difference-image approach using a matched filter/box-rim filter combination effectively removed the structured background from the image. A locally adaptive gray-level thresholding technique was then used for extraction of the signals from the resulting difference image. Signal-extraction criteria based on the size, contrast, number, and clustering properties of microcalcifications were next imposed on the detected signals to distinguish true signals from noise or artifacts. The detection accuracy of the computer scheme was evaluated by means of a free response receiver operating characteristic (FROC) analysis. It was found that, for simulated subtle microcalcifications superimposed on normal mammograms, the difference-image approach with a matched filter/box-rim filter combination could yield a true-positive cluster detection rate of 80% at a false-positive detection rate of one cluster per image. In a study of 20 clinical images containing moderately subtle microcalcifications, the automated computer scheme obtained an 82% true-positive cluster detection rate at a false-positive detection rate of one cluster per image. These results indicate that the automated method has the potential to aid radiologists in screening mammograms for clustered microcalcifications.

Breast Diseases↗
PubMed1987

Spectroscopic studies on the interaction of phosphate with uteroferrin.

The effect of phosphate on the binuclear iron center of pink (reduced) uteroferrin was examined by magnetic resonance and optical spectroscopy. The purple (oxidized) protein, which contains 1 mol of tightly bound phosphate per mol of enzyme at isolation, does not give rise to a 31P NMR signal. Phosphate binding to phosphate-stripped pink uteroferrin is indistinguishable from that in the native purple phosphoprotein. As measured by EPR and optical spectroscopy, the rate of reaction between phosphate and pink uteroferrin is pH-dependent, decreasing as the pH increases. Phosphate is capable of binding to the reduced protein between pH 3 and 7.8, resulting in formation of the purple uteroferrin-phosphate complex. Evans susceptibility measurements at pH 4.9 indicate that the EPR silent species with a maximum absorption at 535 nm, generated upon phosphate addition to pink uteroferrin, is diamagnetic. Moreover, phosphate causes disappearance of the hyperfine-shifted resonances in the 1H NMR spectra of the reduced protein. We therefore have not been able to identify the paramagnetic "purple reduced enzyme-phosphate complex" reported by Pyrz et al. (Pyrz, J. W., Sage, J. T., Debrunner, P. G., and Que, Jr., L. (1986) J. Biol Chem. 261, 11015-11020) using Mossbauer spectroscopy and dithionite-reduced 57Fe-reconstituted uteroferrin. Our present data with native unmodified enzyme are in accord with our earlier results (Antanaitis, B. C., and Aisen, P. (1985) J. Biol. Chem. 260, 751-756) and with the results of Burman et al. (Burman, S., Davis, J. C., Weber, M. J., and Averill, B. A. (1986) Biochem. Biophys. Res. Commun. 136, 490-497) on bovine spleen phosphatase, suggesting that phosphate binding to reduced protein rapidly induces oxidation of the binuclear iron center.

Acid Phosphatase↗
PubMed1987

Hydroxyl radical formation and iron-binding proteins. Stimulation by the purple acid phosphatases.

The effect of the purple acid phosphatases with binuclear iron centers (uteroferrin and bovine spleen phosphatase) on hydroxyl radical formation by iron-catalyzed Haber-Weiss-Fenton chemistry has been compared to that of lactoferrin and transferrin. Using 5,5-dimethyl-1-pyrroline-1-oxide to detect superoxide and hydroxyl radicals and the xanthine-xanthine oxidase system to generate superoxide and hydrogen peroxide, we have observed by ESR spectroscopy that both phosphatases were able to promote hydroxyl radical formation. Lactoferrin and transferrin were found incapable of giving rise to these reactive species. This can be explained by the fact that lactoferrin and transferrin carry two Fe(III) atoms per molecule, neither of which are readily reduced by biological reductants. In contrast, the phosphatases possess a binuclear iron center in which one of the iron atoms is stabilized in the ferric state, but the other freely undergoes one-electron redox reactions. The redox-active iron may act as a catalyst of the Haber-Weiss-Fenton sequence, thus enabling the reactions generating hydroxyl radical to proceed. The iron complex of diethylenetriamine penta-acetic acid, also redox active, was investigated and found as well to promote Haber-Weiss-Fenton chemistry.

Acid Phosphatase↗
PubMed1987

A new type of albumin with predominantly increased binding affinity for 3,3',5-triiodothyronine in a patient with Graves' disease.

A new type of serum albumin, that shows a markedly enhanced binding activity for 3,3', 5-triiodothyronine (T3), a somewhat increased activity for thyroxine (T4), and a normal activity for 3,3', 5-triiodothyronine (rT3) is described. This albumin was found in a patient with Graves' disease. After successful subtotal thyroidectomy, the existence of abnormal binding activity for T3 was suspected in this patient because of persistently increased total T3 concentrations in spite of elevated thyrotropin levels. Although free T3 and T4 concentrations measured by radioimmunoassay using commercial tracer analogue kits were markedly increased, those measured by equilibrium dialysis were within normal ranges. Electrophoretic studies revealed that these abnormalities were due to the markedly increased T3 binding activity by the serum albumin; that for T4 was also slightly increased. Scatchard plot analysis revealed that the association constant (Ka) for T3 of the patient's albumin was 5.1 X 10(6)/M (normal pooled albumin; 6.2 X 10(5)/M), and those for T4 and rT3 were 5.2 X 10(6)/M and 2.7 X 10(6)/M, respectively (normal pooled albumin; 2.1 X 10(6)/M for both T4 and rT3). The increased binding of albumin to T3 and T4 was markedly inhibited by barbitone, and 8-anilino-1-naphthalene-sulfonic acid. These characteristic features, and erroneously high values of free T3 and T4 concentrations measured by tracer analogue kits were similar to those seen in patients with familial dysalbuminemic hyperthyroxinemia, which have been previously reported. These findings strongly suggest that this albumin is a new variant in various dysalbuminemic syndromes, and the abnormal binding of iodothyronines moieties in these syndromes are not biochemically identical.

Adult↗
PubMed1987

Digital image processing of dentomaxillofacial radiographs.

The improvement in the image quality of dentomaxillofacial radiographs (panoramic radiographs) with the use of a digital image-processing system was examined. Linear and nonlinear unsharp masking techniques were employed for image processing. The quality of the processed images was found to be markedly improved over that in original radiographs. The detail visibility of linearly enhanced images, especially in low-density areas, was superior to that of nonlinearly enhanced images, although the presence of more artifacts and more noise was noted in linearly enhanced images. Radiographic diagnosis in the dentomaxillofacial region can be improved with this system.

Humans↗
PubMed1987

Urinary fluoride monitoring of industrial hydrofluoric acid exposure.

Preworkshift and postworkshift urinary fluoride concentrations were measured in 142 hydrofluoric acid (HF) workers and 82 unexposed workers aged 18 to 59. Postshift urinary fluoride concentration in HF workers was significantly higher than that in preshift or control workers. A linear relationship was observed between the mean values in urinary fluoride concentration and the HF concentration in the air. The mean urinary fluoride concentration of 4 ppm and its lower fiducial limit (95%, P = 0.05) of 2 ppm (specific gravity 1.024) were estimated corresponding to the atmospheric HF concentration of 3 ppm, which is the maximal allowable concentration recommended by the Japanese Association of Industrial Health and also the threshold limit value suggested by the American Conference of Governmental Industrial Hygienists. The results suggest that exposure to HF can be monitored by determining the urinary fluoride concentration.

Adolescent↗
PubMed1987

A reliable technique of free vascularized sural nerve grafting and preliminary results of clinical applications.

A technique of harvesting a free vascularized sural nerve graft based on either the cutaneous branch of the peroneal artery or the muscular perforating branch of the posterior tibial artery is described. Anatomic dissections with dye injection studies confirmed the reliability of this blood supply to a 25 cm long segment of the sural nerve. The sural nerve can be sectioned into as many as four segments while safely maintaining each segment's vascularity through intact fascia. A skin monitor can be elevated with the nerve to monitor vascular patency. The free vascularized sural nerve was used to reconstruct 16 nerve defects in the upper extremity. All 13 skin monitors elevated have survived. Early follow-up (range, 2 to 31 months) has shown encouraging clinical recovery. Although our preliminary results are difficult to compare with other series, this technique appears promising in clinical circumstances when interfascicular nerve grafting is indicated but the recipient bed is heavily scarred and poorly vascularized.

Adolescent↗
PubMed1987

Basic imaging properties of a large image intensifier-TV digital chest radiographic system.

The basic imaging properties of a large (57 cm) image intensifier (I.I.)-TV digital imaging system were examined to determine the effects of various physical parameters on the quality of the digital chest images obtained, and also to explore the clinical usefulness of the system. The characteristic curve of the digital system, which relates the output pixel value to the input relative x-ray intensity, was measured with an aluminum stepwedge. MTFs were determined using slit images, and the veiling-glare fraction was measured with a lead-disk technique. Noise Wiener spectra were obtained from uniformly exposed images. The current limitations of the large II-TV digital chest system are its low spatial resolution, and the presence of large amounts of veiling glare and structure mottle. Advantages of this system over other digital chest imaging systems include the high speed of image data acquisition and the capability of "real-time" dynamic imaging of the chest at a radiation dose comparable to that in conventional radiography of the chest.

Humans↗