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Biomedical subjects

H Kitamura

Publications and source records attributed to H Kitamura.

At least 487 records · Page 27Linked to original sources
PubMed1985

C56 formation in the reaction mixture of isolated complement components through the classical complement pathway.

The mechanism of hemolysis of unsensitized erythrocytes by a mixture of 9 isolated, human-derived complement components, C1s, C4, C2, C3, C5, C6, C7, C8 and C9 (C1s-C9) was studied. Of the tested erythrocytes, guinea pig erythrocytes (Egp) were the most susceptible to lysis by C1s-C9, followed by human and sheep erythrocytes. Contamination of the isolated complement components by C56 was ruled out. It was determined that a factor was generated in the reaction mixture of C1s, C4, C2, C3, C5 and C6 (C1s-C6), which had lytic activity against Egp when C7, C8 and C9 were added. We found that the lytic factor was similar to C56 in the following properties: (1) the activity of the lytic factor decreased when incubated with isolated C7 prior to its reaction with Egp; (2) the lytic factor did not bind to Egp by itself but it did bind in the presence of C7; (3) EDTA did not have any inhibitory effect on the lytic factor; (4) the activity of the lytic factor decreased by treatment with anti-C5 and anti-C6 but not by treatment with anti-C3 and anti-C4, and (5) gel filtration of the reaction mixture (C1s-C6) indicated that the elution volumes of the lytic factor and of isolated C56 were similar. Thus, it is likely that C56 is generated in the reaction mixture of C1s-C6 and the lytic factor binds to unsensitized erythrocytes together with C7, to form an intermediate EC567 which is susceptible to lysis by the action of C8 and C9.

Animals↗
PubMed1985

Epithelial-mesenchymal interface in the rat mandibular process observed by electron microscopy.

Epithelial-mesenchymal interfaces in the stomodeal side of the rat mandibular processes were observed at Theiler's stages 14 and 15, when no epithelial organogenesis could be detected by electron microscopy. At stage 14, the basal lamina was discontinuous. Disintegrated basal lamina-like materials were seen in the epithelial-mesenchymal interface. A number of coated vesicles and smooth vesicles were seen in epithelial cell processes adjacent to the disintegrated basal lamina-like materials. Some epithelial cell processes penetrated into the mesenchymal space through the basal lamina and touched the ectomesenchymal cells. Other epithelial cell processes or satellite cell bodies protruded into the mesenchymal space, but were covered with basal laminae. At stage 15, the basal lamina was smooth and continuous with partial duplications. Ruthenium red-positive anionic sites were distributed in the basal lamina and on thin filaments underneath the basal lamina. At stage 15, the separation among anionic sites became more regular than that at stage 14. In this study we found some stage-specific morphological events in the epithelial-mesenchymal interface in the stomodeal side of the mandibular process at stages preceding the initiation of epithelial organogenesis.

Animals↗
PubMed1985

[Automated autoradiographic grain counting of DNA repair in cultured human fibroblasts after ultraviolet irradiation].

Measurement of autoradiographic grains produced by the decay of incorporated radioisotopes is often used for a quantitative assay of the rate of DNA replication and DNA repair in cells or tissues. However, visual grain counting by microscopic observation is time-consuming and tedious process. Recently, Kraemer et al. reported that automated measurement of grains in cultured human cells may be facilitated by using appropriate grain counting instruments. Under their experimental conditions using Kodak NTB-3 emulsion, instrument-determined grain number per nucleus was proportional to visual counts up to 30 grains, and then leveled off at much larger visual counts. The saturation phenomenon was due to counting-loss by the instrument caused by overlapping of neighboring grains. To prevent the counting-loss, we have used in the present study Japanese Sakura NR-M2 emulsion which is less sensitive to radiation exposure than Kodak NTB-3, thereby yielding smaller size of grains per radioactive decay. Samples were prepared from cultured skin fibroblasts derived from normal individuals and xeroderma pigmentosum (XP) patients defective in DNA repair. These cells were irradiated with 254 nm UV incubated for 3 h with culture medium containing 3H-thymidine, and autoradiograms were made by dipping in Sakura NR-M2 emulsion. The number of grains as well as grain surface area per nucleus was measured by using ARTEK CYTO TALLY MODEL 900 counting instrument, and compared with visual counts. The results showed that, under our optimum condition, the instrument-determined number of grains was directly proportional to visual counts, at least up to 150 grains per nucleus, with a correlation coefficient of 0.971.(ABSTRACT TRUNCATED AT 250 WORDS)

Autoradiography↗
PubMed1985

[Differences in left ventricular systolic performance during exercise in patients with hypertrophic cardiomyopathy and systemic hypertension].

To evaluate differences in systolic global and regional performances of the left ventricle during exercise, multi-stage submaximal exercise echocardiography was used for 21 patients with hypertrophic cardiomyopathy (HCM) and 14 patients with systemic hypertension (HT), whose interventricular septa (IVS) were nearly the same in thickness (HCM; 16.5 +/- 2.4 mm, HT; 15.4 +/- 1.7 mm, NS). The data were compared with those of 18 normal subjects (N). During exercise, end-diastolic dimension (EDD) was increased in all three groups; however, there was no statistical differences among the three groups either at rest or during exercise. End-systolic dimension (ESD) was significantly decreased during exercise in HT (29.3 +/- 5.8 at rest to 28.1 +/- 5.8 mm at the peak exercise, p less than 0.05) and N (from 30.3 +/- 3.3 to 25.7 +/- 3.0 mm, p less than 0.001). On the other hand, ESD of HCM at rest, which was less than those of the other two groups, did not decrease with exercise (from 25.1 +/- 4.5 to 25.6 +/- 4.6 mm, NS), and rather they increased (more than 2 mm) during exercise in seven patients. The % shortening fraction (%SF) increased from rest to exercise both in HT (35.6 +/- 7.9% to 40.1 +/- 9.6%, p less than 0.001) and in N (from 35.1 +/- 4.2 to 45.9 +/- 4.7%, p less than 0.001). However, in the HCM group, the %SF, which was significantly greater at rest than in the other two groups, did not increase during exercise (42.5 +/- 6.8 to 42.5 +/- 8.8%, NS). In addition, in seven of 21 patients with HCM, the %SF increased more than 5% at the peak exercise. At rest, systolic wall thickening (%WT) of the IVS equally reduced both in HCM and HT. It increased in HT from 20.8 +/- 9.3% at rest to 24.6 +/- 12.7% at the peak exercise (p less than 0.05), but did not change in HCM (from 16.6 +/- 9.6% to 16.3 +/- 7.0%, NS). At rest, %WT of the left ventricular posterior wall (LVPW) was significantly greater in HCM than in HT. During exercise, it increased in HT (from 43.1 +/- 15.9% to 61.9 +/- 20.5%, p less than 0.01), but did not increase in HCM (from 81.0 +/- 27.7% to 85.5 +/- 29.6%, NS).(ABSTRACT TRUNCATED AT 400 WORDS)

Adult↗
PubMed1985

Fate of recombinants of the rat mandibular epithelium with cranial ectomesenchymal cells of different sources in vitro.

The recombinants of the mandibular molar bud epithelia with cranial ectomesenchymal cell groups from several different sources--mandibular molar area, tongue anlagen, and lateral nasal process--were cultured. Dental laminalike buds were developed in each of the recombinants (incidence of development 38-86%). In the heterotrophic recombinants, heterotypic differentiation of mandibular epithelium was also induced. However, the foreign ectomesenchymal cells were not induced heterotypically by the epithelial genetic factor, but the mesenchymal genetic factor is maintained. It is suggested that mandibular molar bud epithelia have potency to proliferate into mesenchyme under non-organ-specific influences of ectomesenchymal cells and that presumptive mandibular mucosal epithelia have multipotency for differentiation sensitive to inductive influences by the heterotypic cranial ectomesenchymal cells but that the mandibular molar bud epithelia have no heterotypic inductive activity for the differentiation of cranial ectomesenchymal cells.

Animals↗
PubMed1985

[Exercise echocardiography to evaluate left ventricular function in mitral and aortic regurgitation].

To assess differences in left ventricular (LV) performance between mitral regurgitation (MR) and aortic regurgitation (AR), exercise echocardiography was performed for 12 patients with MR and 18 patients with AR, and the results were compared with those of 11 normal subjects. These patients with LV volume overloads were all in the NYHA class I or II. There were no differences in age or sex distributions between the two groups. Symptom-limited submaximal exercise was performed on an ergometer in the supine position. The results obtained were as follows: LV dimensions at end-diastole (EDD) and end-systole (ESD) were greater in the diseased groups than in the normal group. Resting EDD and ESD showed no differences between the MR and the AR groups. There were no differences in exercise-induced increases in heart rates or elevations of systolic blood pressures among the three groups. During exercise, EDD increased and ESD decreased in the normal group, and similar results were obtained for the MR group. However, in the AR group, EDD and ESD remained unchanged. Ten of the 18 patients with AR had decreased ESD, and eight had unchanged or increased ESD during exercise. Resting shortening fractions were equally distributed among the three groups. During exercise, the shortening fractions were significantly increased in the normal and the MR groups. In the AR group, shortening fractions remained at resting values, with variable responses in individual cases. Systolic wall thickening of the interventricular septum and the LV posterior wall showed similar responses of shortening fractions. The relation between the peak systolic wall stress index (PSSI) and ESD, or PSSI and the shortening fraction revealed that exercise induced an afterload mismatch of LV performance in some patients with AR. Thus, though resting LV performances did not differ from each other, an afterload mismatch is more easily induced with exercise in patients with AR than in patients with MR. This may be one of the cause of the different clinical courses in these two groups with LV volume overloads.

Adult↗
PubMed1985

[Left ventricular wall motion in ischemic heart disease quantitatively assessed by three-dimensional vectors of reference points in multi-directional two-dimensional echocardiography].

Left ventricular wall motion was analyzed in a spatial geometric manner assuming the quantitative vectors formed by the reference points' movement on two-dimensional echocardiogram in 58 normal subjects and 40 patients with ischemic heart disease. Long-axis, RAO-equivalent and short-axis views, termed sagittal, frontal, and horizontal planes, respectively, were visualized and two or three reference points were defined on each plane. The vectors of these points' movement were obtained from video-image tracings on each plane and systolic excursion and distortion angles of each pair of reference points were vectorially assessed. All vectors in myocardial infarction were directed towards the infarcted areas. Clockwise horizontal distortion of the left ventricle apex-to-base axis was observed in normal subjects, but it was slight (3.1 +/- 3.0 degrees: mean +/- SD at the papillary muscle horizontal section). However, larger horizontal distortion was observed in single coronary artery disease, which may lead to the erroneous segmental wall motion analysis using conventional cineangiography because of the overlap of the adjacent segments.

Adult↗
PubMed1985

[Coronary reserve of the right ventricle evaluated by double dose T1-201 scintigraphy].

Thallium-201 double dose scintigraphy was applied to exercise to estimate the coronary blood flow reserve of the left and right ventricles and this was compared with the degree of coronary artery stenosis. As an index of coronary reserve we measured the rate of change of blood flow distribution (delta F) calculated from the change in myocardial radioactivity following thallium-201 injections, once at rest and once during exercise. With submaximal exercise the increases in delta F of the left ventricle were less in patients with ischemic heart disease than in the control subjects, and were less as the number of diseased coronary vessels increased. The increases of delta F of the right ventricle were less in patients with stenosis of the proximal portion of the right coronary artery than in patients without stenosis and in the control subjects. The more severe the stenosis of the proximal portion of the right coronary artery, the smaller the delta F of the right ventricle. These results indicate that evaluation of the delta F in the left and right ventricles is useful in estimating coronary artery stenosis.

Coronary Circulation↗
PubMed1985

Pathologically defined neuro-, vasculo-, entero-Behçet's disease.

Behçet's disease is characterized clinically by the presence of a diagnostic triad of stomatitis, genital ulceration and uveitis. Multiple other organ systems may be involved. Prognosis is related to the presence of central nervous system, vascular or intestinal involvement. This report describes the pathology of neuro-, vasculo- and entero-Behçet's disease in a single patient.

Adult↗
PubMed1984

Light and electron microscopic studies on the cytological changes in the rat pancreatic islets induced by sodium diethyl dithiocarbamate (DEDTC) administration.

The effect of sodium diethyl dithiocarbamate ( DEDTC ) administration upon the structure of the pancreatic islet cells has been examined in the rat. In light microscopy, the aldehyde fuchsin stainability of the B cell granules was found to increase notably at 6 h and thereafter following the medication. In electron microscopy, the B cell granules with a porous core were shown to predominate over those with a homogeneous core containing paracrystalline structures between 30 min and 3 h following the medication. Between 6 and 12 h following medication, occasional B cells were seen to be provided with large secretory granules with a porous core. The results of the present study have been discussed with special reference to the chelating action of DEDTC .

Animals↗