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Biomedical subjects

K Harada

Publications and source records attributed to K Harada.

At least 883 records · Page 49Linked to original sources
PubMed1990

[Studies on the cooperation-enhancing approach in dealing with children in the dental setting. 4. Relationship between adaptability to dental treatment and behavioral and emotional reactions before and during treatment].

The correlation between the behavioral and emotional reactions before dental treatment and the adaptability to dental treatment was evaluated in 84 three-to-six-year old children. Also the physical behavior of the children, the verbal reaction of the children and the speaking of dentists to the children during treatment were investigated among 13 cooperative and 13 uncooperative three-to-six-year old children. Dental treatment was conducted with tooth brushing, surface anesthesia, infiltration anesthesia, rubber dam application, cavity preparation with air turbine, cavity preparation with electric motor and composite resin filling. The results are summarized as follows: 1. There was a significant correlation between twelve of the twenty behavioral and emotional reactions before treatment and the adaptability to dental treatment. 2. The children who showed an uncooperative behavior to dental treatment showed a higher score of physical behavior during each treatment than the children who showed a cooperative behavior to dental treatment. 3. The score of physical behavior increased as the treatment progressed from tooth brushing to infiltration anesthesia. Among the children who showed cooperative behavior, the score showed a peak at the infiltration of anesthesia and then decreased. On the other hand, the children who showed uncooperative behavior continued showing a high score. 4. The uncooperative children showed a higher frequency of verbal reaction and crying than the cooperative children. 5. The frequency of speaking of the dentist to the uncooperative children was one and a half times as much as to the cooperative children. More than sixty percent were "instructions" and "explanations" to both of the cooperative and uncooperative children. "Praise" was used more to the cooperative children, and "count 10" and "encourage" were used more to the uncooperative children.

Child↗
PubMed1990

[Three-dimensional study of the microvascular network in the excretory end portion and the excretory ducts system of dog parotid gland].

The purpose of this study was to undertake a three-dimensional analysis of the microvascular network of the glandular body and the excretory ducts system of the dog parotid gland using microcorrosive resin casting technique and examined under scanning electron microscope. Results were as follows: 1. Contributed to the direct injection of the resin through the papilla of parotid, not only the excretory ducts but also the striated ducts, intercalated ducts and the end portion were completely filled with resin, thus enabling the fabrication of the intact casts. 2. One of the advantages of the present method was the ability to distinguish the each portion of the excretory ducts system based on the resin casts surface appearance of the different structure of the wall of the lumen. 3. Within the glandular body arteries, veins and excretory ducts vessels were found running their course through the connective tissue, finally emerging through the hilus of lobules into the lobules. However, several arterioles and venules, besides of running through the hilus, directly terminated at the capillary network in lobules. 4. No arteriovenous anastomoses (AVAs) were found in the lobules. However, AVAs were observed between the arterioles and venules distributed in the connective tissue around the lobules. 5. A large number of venous valves were observed in the veins immediately emerging from the hilus of lobules and also in the veins within the connective tissue of the gland. 6. Observing the vascular network of excretory ducts system, there was no proper vascular network belong to the intercalated ducts, however, on the striated ducts, one layer of the vascular network composed of dense capillaries was identified. Confluencing with each other, the diameter of excretory duct increased and its vascular network consist of two layers of vascular network of which inner layer was a dense capillary network similar to the striated ducts, the outer layer was a loose network composed of arterioles and venules. In the main excretory duct, these two layers of the vascular network were composed completely. 7. Some AVAs were observed in the arteriole and venule network around the main excretory duct.

Animals↗
PubMed1990

[Unsharpness of redundant shadows of the mandibular ramus region in panoramic tomography. The influence by the first slit width].

In panoramic tomography, redundant shadows of the mandibular ramus overlapping with tomographic images on the opposite side prevent radiological diagnosis. Redundant shadows differ from tomographic images in sharpness, film contrast, and imaging quality. In addition to mismatching of film velocities and X-ray beams, familiar causes of such unsharpness, still another source must be taken into consideration: the influence of varying slit widths. In the past, research has been concentrated on real images defined by McDavid et al.; that is, tomographic images and tomographic blurring images. The present study, however, qualitatively evaluates the unsharpness of redundant shadows of the mandibular ramus, especially with reference to the effects of first-slit width. At the same time, comparisons are made with tomographic images overlapping with redundant shadows of the mandibular ramus region. An orthopantomograph OP5 was employed as the panoramic X-ray apparatus. In the first step of the evaluation, X-ray beam alignments were examined in the horizontal dimension. To evaluate unsharpness of the mandibular ramus, we used regression analysis by the least-squares method and the Nitka method. Horizontal beam alignments and image layers as calculated by McDavid et al. (1985) were applied in setting the aluminum plate. Conclusions 1. In the case of redundant shadows of the mandibular ramus, unsharpness of the posterior margin and the condylar process depends on first-slit width, which is a major influence on imaging quality. 2. Intensity of edge and film contrast exert about equal influences on unsharpness of redundant shadows of the mandibular ramus. Both factors were influenced by the set-up position of the subject. 3. Film contrast exerted a greater influence than edge intensity on unsharpness of overlapped tomographic images. 4. The wider the first-slit width, the greater the indistinct area of redundant shadows of the mandibular ramus and overlapped images. But, for the purposes of diagnosis, maximum slit width is probably between 3 and 5 mm.

Artifacts↗
PubMed1990

A statistical study of autopsied cases of neonatal intraventricular hemorrhage.

We have performed a statistical study of 1218 autopsies of neonates to extract the factors related to fatal neonatal intraventricular hemorrhage (IVH). Prematurity indicated by a short gestational period or a low birth weight was the most significant factor for IVH. Many other factors considered to be related to IVH were also related closely to prematurity. Therefore, we pose the following question throughout the study: Did the factors independently relate to IVH without any confounding effects of prematurity? To obtain the answer, we tried a statistical adjustment for gestational age to eliminate the confounding effects of prematurity. After the adjustment was made, we concluded that the following 10 items, in order, were the actual factors related to fatal IVH: prematurity, subependymal hemorrhage, subarachnoidal hemorrhage, respiratory distress syndrome, hyaline membrane disease, respiratory acidosis, intracerebral hemorrhage, cyanosis, respirator care, and low Apgar score. There were two distinctive categories in the factors that were eliminated by the adjustment. One was a group that has no significance whatsoever in any subdivided gestational groups, such as meconium aspiration syndrome, due to purely the result of the confounding effect. The other was a group that showed its statistical significance only in a certain period of gestation, such as breech presentation.

Autopsy↗
PubMed1990

Heterogeneity in lectin-binding characteristics of human lymphokine-activated killer cells.

The binding of various lectins to human lymphokine-activated killer (LAK) cells was investigated. Human peripheral blood lymphocytes were cultured for 3 days with recombinant interleukin-2 (rIL-2), and then stained with 20 kinds of lectins. There were four types of lectin-binding patterns: (a) negative staining; (b) weakly positive staining; (c) strongly positive staining; and (d) two populations, one weakly and one strongly positive staining. Among the 20 kinds of lectins, both Lens culinaris agglutinin (LCA) and Pisum sativum agglutinin (PSA) showed two peaks in the staining patterns on LAK cells (type 4). We separated these two populations of LAK cells by using a cell sorter, and assayed them for cytotoxic activity against 51Cr-labeled Hela cells. The LAK cells that were strongly stained by LCA or PSA [LCA (or PSA)-bright LAK cells] showed stronger cytotoxic activity than the LAK cells that were weakly stained by LCA or PSA [LCA (or PSA)-dull LAK cells]. Furthermore, we separated lymphocytes with LCA or PSA before culturing them with rIL-2 (LAK precursor), and we found that both LCA-bright and PSA-bright lymphocytes can develop into LAK cells with higher cytolytic activity. LCA-bright lymphocytes kept their ability to be stained strongly with LCA even after culture with rIL-2 for 3 days. Similarly, LCA-dull lymphocytes were still stained weakly after culture with rIL-2. Two-color assay of LAK cells revealed that 78% of NK (CD16+)-LAK cells and 46% of T (CD3+)-LAK cells were LCA-bright cells.(ABSTRACT TRUNCATED AT 250 WORDS)

Antigens, CD↗
PubMed1990

[PET study on cerebral hemodynamics in internal carotid artery occlusion--the pathogenesis of watershed infarction].

We studied positron emission tomography in nine patients with unilateral internal carotid artery occlusion, selected as having good collateral circulation through the anterior portion of the circle of Willis. Analyses of regional cerebral blood flow, cerebral oxygen metabolic rate, oxygen extraction fraction, and cerebral blood volume allowed quantitative evaluation of the regional hemodynamic status, especially in relation to watershed area. The patient group has a significantly (p less than 0.01) decreased regional blood flow in the middle cerebral artery territory and the surrounding watershed areas of the occluded hemisphere, as compared with eight control subjects. Values of oxygen extraction fraction became progressively greater farther from the circle of Willis, attaining the highest level in the superior parietal and posterior temporal-occipital watershed area. Oxygen extraction fraction gave information on the balance of energy supply and demand, serving as an index of the oxygen carriage reserve. A concomitant decrease in the ratio of cerebral blood flow to volume suggested reduction in mean flow velocity with possible development of "stagnation thrombus". These findings suggest 1) hemodynamic vulnerability of watershed areas after internal carotid artery occlusion and 2) importance of systemic hemodynamic factors such as blood pressure and circulating blood volume in the genesis of watershed infarctions.

Aged↗
PubMed1989

Purification and characterization of a protein containing D-aspartic acid in bovine lens.

A protein containing biologically uncommon D-aspartic acid (DAsp) was extracted with 60% EtOH from the water-insoluble fraction of bovine lens. The protein was purified by DEAE-TOYOPEARL chromatography and electrical elution by SDS-polyacrylamide gel electrophoresis (SDS-PAGE) followed by reverse-phase chromatography. The D/L ratio of aspartic acid in the protein isolated was 0.12. The molecular weight of this protein was estimated to be 22,500 by SDS-PAGE. The high content of serine, glycine and glutamic acid was noteworthy. It has been considered that the presence of DAsp in the living body is caused by racemization closely related to aging. The age of bovines used was relatively young (5 years old). If the racemization was caused by aging, the presence of DAsp in the relatively young bovine lens suggested that the aging of the lens protein may start at a relatively young age. The protein containing DAsp may be generally present in lens beyond species such as mouse, bovine and human.

Aging↗
PubMed1989

[Siderotic regenerating nodules in liver cirrhosis--evaluation by gradient echo (FLASH) imaging 1.5T].

In three patients with histologically proven liver cirrhosis, a large number of small, low-intensity nodule(SLIN)s was clearly seen on gradient echo(GRE) images which are sensitive to field inhomogeneity. A histological study revealed that the SLINs corresponded to the regenerating nodules, laden with iron, of liver cirrhosis. As TE was prolonged, the SLINs increased in size in all three cases and fused with each other in one of three cases on GRE images. This phenomenon suggests that the magnetic susceptibility effect due to iron included in the regenerating nodules is the cause for the regenerating nodules shown as SLINs on GRE images, and that one SLIN does not always correspond to one regenerating nodule. We conclude that GRE images should be considered important for diagnosis of regenerating nodules in liver cirrhosis.

Female↗
PubMed1989

Foam counter-current chromatography of bacitracin. I. Batch separation with nitrogen and water free of additives.

A foam counter-current chromatographic method utilizing a true counter-current movement between nitrogen and distilled water through a long narrow coiled tube is described. Samples introduced into the coil are separated according to their foaming capability: foam-active materials generate foam and quickly move with nitrogen toward one end of the coil while the remainder are carried with the liquid stream in the opposite direction and eluted through the other end of the coil. The utility of the method was demonstrated in the fractionation of commercial bacitracin (BC). Hydrophobic components including BC-A, BC-F and several minor components were enriched with foam and collected in decreasing order of hydrophobicity, whereas hydrophilic components were eluted with the liquid in decreasing order of polarity. The results indicate that foam-active components can be effectively separated by foam counter-current chromatography using nitrogen and distilled water without a surfactant or other additives.

Bacitracin↗
PubMed1989

Improvement of chemical analysis of antibiotics. XVI. Simple and rapid determination of residual pyridonecarboxylic acid antibacterials in fish using a prepacked amino cartridge.

A simple and rapid method for the determination of residual pyridonecarboxylic acid antibacterials (PCAs) (oxolinic acid, nalidixic acid and piromidic acid) in fish was developed using a combination of high-performance liquid chromatography (HPLC) and clean-up with an amino-type prepacked cartridge. PCAs were extracted with n-hexane-ethyl acetate (1:3) and the extract was applied to a Baker 10 amino cartridge. PCAs were eluted from the cartridge with acetonitrile-methanol-0.01 M aqueous oxalic acid solution (pH 3.0) (3:1:6) and were determined by HPLC. The separations were performed on Nucleosil 3C18 (3 microns, 75 x 4.6 mm I.D.) using a mobile phase containing oxalic acid. The recoveries of PCAs from various fishes fortified at the level of 1.0 ppm were 77.1-95.5%, and the detection limits were 0.05 ppm. The analytical time per sample was less than 30 min.

Animals↗
PubMed1989

[Magnetic resonance imaging of the lumbar spine--comparison of multiple spin echo and low flip angle gradient echo imaging].

Sixteen patients including 13 cases with disk herniation and 3 cases with spondylosis of lumbar spine were examined on a resistive MRI system operating at 0.1 T. All lesions were studied with both multiple spin echo (MSE) and low flip angle gradient echo (LF) techniques to evaluate which technique is more effective in detecting the disk degeneration and the indentation on subarachnoid space. MSE images were obtained with repetition time (TR) of 1100-1500 ms or cardiac gating, an echo time (TE) of 30, 60, 90, 120, 150, and 180 ms symmetrical 6 echoes, and total acquisition time of more than 281 sec. LF images were obtained with TR of 500, 250, and 100 ms, TE of 18 ms, a flip angle of 30 degree, and total acquisition time of 128 sec. Eleven lesions of spinal disk degeneration and 12 of indentation on subarachnoid space were detected with LF. On the other hand, 26 lesions of spinal disk degeneration and 38 of indentation on subarachnoid space were detected with MSE. Although the parameters of LF employed in this study were relatively effective to emphasize T2*-based contrast, the ability of LF in detection of spinal disk degeneration and indentation on subarachnoid space is less than that of MSE. Signal contrast to noise ratios for normal disk and degenerative disk, epidural-fat and disk herniated material, CSF and disk herniated material, and epidural-fat and CSF were less than 4 with LF, but more than 4 with MSE.(ABSTRACT TRUNCATED AT 250 WORDS)

Humans↗
PubMed1989

High-performance liquid chromatography of proteins on N-methylpyridinium polymer columns.

Two types of 4-methylpyridinium polymers (4VP-DVB-Me and 4VP-EG-Me, cross-linked with divinylbenzene and ethylene glycol dimethacrylate, respectively) were employed for the analysis of proteins in ion-exchange high-performance liquid chromatography. These polymers had different physical properties in the dry state, but showed similar retentions in size-exclusion chromatography using carbohydrate standards. Generally, the 4VP-EG-Me column was superior to the 4VP-DVB-Me column with regard to separation and recovery of proteins.

Chromatography, High Pressure Liquid↗
PubMed1989

[Clinical significance of the intranuclear cleft of the lumbar intervertebral disk on MRI].

MR studies of the lumbar spine in 111 patients were analyzed at 469 disks to assess the prevalence of intranuclear cleft (INC) in the lumbar intervertebral disk. MR studies were performed on either 0.1-tesla (T) magnet (69 patients) or 0.22-T magnet (42 patients). The pulse sequences reviewed were saturation recovery (SR; TR = 0.5 sec), short TR, TE spin echo (S-SE; TR = 0.5 sec, TE = 34 msec) and long TR, TE spin echo (L-SE; TR = 1.5 sec, TE = 68,80 msec). All study were done in a sagittal plane with 10 mm slice thickness. The conclusions were as follows: 1) On a 80 msec TE, 1.5 sec TR image, INCs were detected in more than 80% of disks in patients over 30 years old but in only 13.3% of disks in patients under 20 years old. 2) In both imaging system, L-SE showed INCs more frequently than SR and S-SE. 3) INCs were less frequently demonstrated in the disk with decreased signal intensity on 0.1-T magnet as compared with 0.22-T magnet. 4) On SR and S-SE, there is an increase in the prevalence of INC in the disk with decreased signal intensity. We suggest that the INC will be a good landmark of the pathological process of the lumbar disk, such as degeneration.

Adolescent↗
PubMed1989

Improvement of chemical analysis of antibiotics. XV. Isocratic high-performance liquid chromatographic methods for the analysis and preparative separation of the components of bacitracin.

Isocratic high-performance liquid chromatographic (HPLC) systems were established for analytical and preparative separation of the components of the antibiotic preparation bacitracin (BC). The best analytical results were obtained using a C18 modified silica gel column (Capcell Pak C18) with a solvent system of 0.04 M disodium hydrogenphosphate buffer and methanol (4:6), pH 9-10. The calibration graphs showed good linear relationships between 50 and 1000 ng for BC-A and between 65 and 1000 ng for BC-F. With respect to the preparative HPLC, a Capcell Pak C18 column with methanol-0.05 M aqueous sodium sulphate solution (6:4) as a mobile phase gave satisfactory results. The isolation of BC-A and -F was readily achieved without decomposition of the components by using the present preparative HPLC followed by desalting on a prepacked C18 cartridge.

Anti-Bacterial Agents↗
PubMed1989

Lung cancer in chromate workers: high-risk group for multiple lung cancer.

We diagnosed eight (8.9%) lung cancer patients in 90 workers exposed to chromate compounds. The duration of exposure ranged from 8 to 31 years, with a mean value of 18 +/- 8 years. The histological classification was squamous-cell carcinoma in seven patients and adenocarcinoma in one patient. The site of origin of the primary tumors was located peripherally in two (25%) and centrally in six (75%). All but one of these patients underwent surgery. In three (37.5%) of these patients, lung cancer foci were detected during the postoperative follow-up by sputum cytology and bronchoscopy. Two of these three patients had multicentric cancer foci: double primary early squamous-cell carcinoma in one and early squamous-cell carcinoma + small-cell lung cancer in the other. In a high-risk group such as chromate workers, we should emphasize early detection of lung cancer by serial sputum cytology, chest x-rays, and bronchoscopy. Lung cancer patients with chromate exposure should be treated with due regard to the possibility of synchronous or metachronous cancer.

Adult↗