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Biomedical subjects

S Sakurai

Publications and source records attributed to S Sakurai.

At least 163 records · Page 9Linked to original sources
PubMed1995

[Immunohistochemical analysis of adhesion molecules in directional coronary atherectomy specimens].

Chronic inflammatory cells are key components in the progression of atherosclerotic plaques and restenosis after coronary angioplasty. Adhesion molecules are fundamental in inflammatory processes. Therefore, the distributions of intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule (VCAM) were investigated in directional coronary atherectomy specimens obtained from 14 patients, in 6 with acute coronary syndromes (myocardial infarction and unstable angina within 1 month), 6 with old myocardial infarction and 2 with stable effort angina. There were eight primary lesions and six restenotic lesions. Atherectomy tissue fragments were snap frozen and cut into 4 microns thick cryostat sections for immunohistochemical staining by avidin-biotin complex immunoperoxidase techniques using adhesion molecule specific monoclonal antibodies BBIG-I1 (ICAM-1) and BBIG-V1 (VCAM). The cells of lesions were characterized in sequential sections by macrophage marker KP1 (CD68), endothelial marker JC/70A (CD31), and smooth muscle cell marker 1A4 (alpha-smooth muscle actin). Four restenotic lesions that had undergone a prior balloon angioplasty within a few months consisted of intimal proliferation and the other lesions were atherosclerotic plaque. Macrophage-rich areas were seen in the lesions from acute coronary syndromes and/or early restenotic lesions. Expression of ICAM-1 or VCAM was strongly associated with macrophage-rich areas, but VCAM staining was weaker than ICAM-1 except in one restenotic lesion. Macrophages that express ICAM-1 and/or VCAM may be important in the unstable plaques and restenotic lesions related to disease activity of ischemic heart disease.

Aged↗
PubMed1995

[Effects of kanamycin on platelet satellitism and leukocyte adhesion phenomena].

To examine the effects of kanamycin on platelet satellitism and leukocyte adhesion phenomena, we added kanamycin to the blood sample which showed the platelet satellitism and the leukocyte adhesion phenomena. We observed the rapid dispersion of platelets from the surface of leukocyte in platelet satellitism and also the rapid dispersion of leukocyte in leukocyte adhesion by addition of kanamycin (20 mg) in 1 ml of EDTA-anticoagulated blood from a patient with both phenomena. Neither adhesion of platelet nor adhesion of leukocyte was found on microscopical examinations after dispersion. Complete blood cell counts and their histogram patterns after dispersion were almost the same as those just after venipuncture. The dispersion was found just after the addition of kanamycin and no re-adhesion was observed. These findings suggest that kanamycin leads to dispersions of leukocyte-leukocyte, platelet-platelet and leukocyte-platelet adhesion phenomena.

Cell Adhesion↗
PubMed1995

Zinc promotes the repair of wounded monolayers of cultured vascular endothelial cells.

The effect of zinc on the repair of wounded monolayers of bovine aortic endothelial cells in a culture system was investigated. It was morphologically found that zinc promotes the appearance of the cells in the wounded area; cell number in the area was significantly increased by zinc. However, other heavy metals including copper, manganese, nickel and cobalt failed to exhibit a similar effect. The repair induced by exogenous basic fibroblast growth factor (bFGF) was potentiated by zinc but that by exogenous acidic fibroblast growth factor was unaffected by the metal. Promotion of the repair of the wounded area by zinc was completely blocked by either cycloheximide or anti-bFGF antibody. In addition, zinc-induced repair was significantly inhibited by a lipoxygenase inhibitor, nordihydroguaiaretic acid but not by a cyclooxygenase inhibitor, indomethacin. From these results, it is suggested that zinc promotes the repair process of damaged vascular endothelium through the lipoxygenase pathway that mediates the response of vascular endothelial cells to endogenous bFGF.

Animals↗
PubMed1994

Evolution of restriction sites of ribosomal DNA in natural populations of the field mouse, Apodemus speciosus.

An analysis by restriction endonuclease digestion of ribosomal DNA (rDNA) was carried out in natural populations of Apodemus speciosus, a field mouse that is endemic to Japan. Two restriction sites, the EcoRI (E3) and DraI (D4) sites, in the nontranscribed spacer region downstream from the gene for 28S RNA showed polymorphism within and between individuals in the populations from the Japanese main islands. By contrast, populations from the small adjoining islands which are thought to have separated from the main islands 1-2 x 10(4) years ago showed relatively low levels of polymorphism within and between individuals, i.e., one of the polymorphic bands in the case of each enzyme was predominant in these populations, irrespective of the variants. These results indicate that the rate of fixation of site variations depends on population size and that the direction of fixation is random. Furthermore, each polymorphic restriction site seems to be fixed independently.

Animals↗
PubMed1994

Phylogenetic relationships among Homo sapiens and related species based on restriction site variations in rDNA spacers.

A rapid method, using 12 restriction enzymes, was employed to analyze variations in ribosomal DNA (rDNA) spacers in a study of phylogenetic relationships between Homo sapiens and related species. We mapped restriction sites in the external and internal spacer regions and compared the arrangements of sites. The estimated sequence divergence between Homo sapiens and Pan troglodytes, Pan paniscus, Gorilla gorilla, Pongo pygmaeus, Hylobates lar, H. agilis, and Macaca fuscata was 2.7, 2.3, 3.8, 7.3, 6.8, 7.8, and 14.1%, respectively. The genetic relationships inferred from these distances generally correspond to those inferred from analyses of other molecular markers in the literature. The divergence between H. lar and H. agilis and between H. lar and H. syndactylus was 0.34 and 2.4%, respectively.

Animals↗
PubMed1994

1994 Nicola Cerulli Young Researchers Award. Downhill walking: a stressful task for the anterior cruciate ligament? A biomechanical study with clinical implications.

Accelerated rehabilitation after anterior cruciate ligament (ACL) reconstruction has become increasingly popular. Methods employed include immediate extension of the knee and immediate full weight bearing despite the risks presented by a graft pull-out fixation strength of 200-500 N. The purpose of this study was to calculate the tibiofemoral shear forces and the dynamic stabilising factors at the knee joint for the reasonably demanding task of downhill walking, in order to determine whether or not this task presented a postoperative risk to the patient. Kinematic and kinetic data were collected on six male and six female healthy subjects during downhill walking on a ramp with a 19% gradient. Planar net joint moments and mechanical power at the knee joint were calculated for the sagittal view using a force platform and videographic records together with standard inverse dynamics procedures. A two-dimensional knee joint model was then utilised to calculate the tibiofemoral shear and compressive forces, based on the predictions of joint reaction force and net moment at the knee. Linear envelopes of the electromyographic (EMG) activity recorded from the rectus femoris, gastrocnemius and biceps femoris muscles were also obtained. The maximum tibiofemoral shear force occurred at 20% of stance phase and was, on average, 1.2 times body weight (BW) for male subjects and 1.7 times BW for female subjects. The tibiofemoral compressive force was 7 times BW for males and 8.5 times BW for females during downhill walking. The hamstring muscle showed almost continuous activity throughout the whole of the stance phase.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1994

Elevation of N1-acetylspermidine and putrescine in hepatic tissues of patients with fulminant hepatitis and liver cirrhosis.

Hepatic polyamines were assayed in 15 patients with liver diseases, 5 with fulminant hepatitis (FH); 3 with exacerbated liver cirrhosis (ELC); and 7 with liver cirrhosis (LC). Hepatic putrescine and N1-acetylspermidine as percentages of total polyamines, were elevated and spermine was decreased in all 15 patients. The increase in hepatic N1-acetylspermidine levels appeared to be greater in patients with FH and ELC than in those with LC. These results suggest that the production of N1-acetylspermidine in human liver is closely associated with the induction of spermidine/spermine N1-acetyltransferase activity in liver diseases.

Acetyltransferases↗
PubMed1994

Detection of monocyte chemotactic and activating factor (MCAF) in normal blood and urine using a sensitive ELISA.

We developed a highly sensitive enzyme-linked immunosorbent assay (ELISA) for human monocyte chemotactic and activating factor (MCAF), an inflammatory cytokine that plays an important role in the recruitment of blood monocytes to areas of inflammation. The ELISA, which is based on a sandwich method using two newly-developed monoclonal antibodies, could quantitatively detect MCAF in the range between 2.5 pg/ml (50 fg/sample) to 300 pg/ml after incubation for a total of 2 h, and showed no cross-reactivity with various structurally-related IL-8 superfamily proteins. It was not affected by blood or urine components non-specifically, and thus was directly applicable to clinical specimens. When serum and urine samples from healthy subjects were measured, they all turned out to contain detectable levels of MCAF (more than 30 pg/ml). By gel-filtration column chromatography analysis, MCAF in the body fluids was eluted as a single peak at the position corresponding to the molecular weight of 10 kD, suggesting that it exists as a monomer form, free from carrier proteins. The established ELISA here is expected to be effectively used for the further investigations on the relationship of MCAF with various inflammatory diseases.

Animals↗
PubMed1994

Sequences and evolutionary analysis of mouse 5S rDNAs.

We selectively amplified the spacer regions of genes for mouse 5S ribosomal RNA (rRNA), which are tandemly repeated, by the PCR method, using primers specific to the two ends of the coding region for 5S rRNA. Fragments of approximately 1.6 kb were amplified from DNA from the BALB/cCrSlc mouse (Mus musculus domesticus), the SM/J mouse (M. m. domesticus), the MOA mouse (M. m. musculus) and the SEG mouse (M. spretus). These fragments were cloned into an appropriate plasmid vector, and two clones representative of each of the four strains were sequenced. The sequences were GC rich (> 60%) and contained a high proportion of very simple repetitive motifs, such as (TG)n and (ATCC)n, which accounted for the intra- and intergenomic length heterogeneity. Excluding such polymorphic regions and neglecting small insertions or deletions, we estimated the sequence divergence between clones. Sequence divergence within a genome averaged 0.26%, and the divergence between individuals of the same subspecies, between subspecies, and between species was 0.44%, 0.62%, and 1.73%, respectively. The results indicate that the spacer region evolved rapidly but with a reduction in heterogeneity within each genome, as a result of certain, as yet unidentified, homogenization mechanisms. The results further suggest that the spacer regions of genes for 5S rRNA may provide good indicators for phylogenetic analysis of closely related species.

Animals↗
PubMed1994

Phylogenetic relationship between the Iriomote cat and the leopard cat, Felis bengalensis, based on the ribosomal DNA.

We analyzed the restriction fragment length polymorphisms in the spacer regions of ribosomal DNA (rDNA), using twelve restriction enzymes, to examine whether the Iriomote cat is related to the leopard cat (Felis bengalensis). A restriction map for each taxon was constructed and the major taxon-specific types of repeating unit (repetypes) were characterized on the basis of the arrangements of restriction sites. The Iriomote cat and the leopard cat share a common repetype but this repetype is different from that of the domestic cat (F. catus) with an estimated sequence divergence of 1.5% and from that of the ocelot (F. paradalis) with an estimated sequence divergence of 2.5%. These results indicate that, phylogenetically, the Iriomote cat is closely related to the leopard cat and that the ancestral population moved from the continent to Iriomote Island quite recently. The rDNA arrays of the leopard cat exhibit considerable intragenomic size-variation, which is thought to have emerged as a result of differences in numbers of repeated DNA segments, whereas the extent of such size-variation is much lower in the rDNA of the Iriomote cat. It appears that, even though migration of the Iriomote cat occurred relatively recently, the population has diverged to some extent from its continental counterpart, perhaps via fixation of preexistent intraspecific variations rather than by generation of new variations.

Animals↗
PubMed1994

Disturbed lipid metabolism in patients with subclinical hypothyroidism: effect of L-thyroxine therapy.

To evaluate whether patients with subclinical hypothyroidism have a disturbance in lipid metabolism, and whether supplemental L-thyroxine (L-T4) therapy would improve their lipid parameters, we measured serum levels of thyroid hormones, TSH and lipid parameters in 34 patients with subclinical hypothyroidism before and 2 months after treatment with L-T4. Before treatment, patients with subclinical hypothyroidism had elevated serum low density lipoprotein cholesterol (LDL-C) concentrations compared with control subjects (P < 0.05). Overall, L-T4 therapy significantly decreased the serum level of TSH (P < 0.01), total cholesterol (TC; P < 0.02), high density lipoprotein cholesterol (P < 0.02), LDL-C (P < 0.05), and the ratio of apolipoprotein B to apolipoprotein A1 (P < 0.05). Lipid values in patients with basal serum TSH levels below 10 mU/l were not affected by L-T4 therapy, whereas serum levels of TC and LDL-C decreases significantly (P < 0.01) in patients with serum TSH levels above 10 mU/l. Thus, the L-T4 treatment appears to have a preventive effect on the disturbance of lipid metabolism in patients with subclinical hypothyroidism, especially in patients with serum TSH levels above 10 mU/l.

Adult↗
PubMed1993

Electron diffraction study on two-dimensional domain structure of L-DPPC monolayer.

A spatial variation in the two-dimensional crystal lattice orientation of L-DPPC monolayer on a hydrophobic substrate was observed by use of an electron microscope with diffraction and dark-field techniques. It is shown that the monolayer has a mosaic structure with domains, each of which consists of a region with a homogeneously oriented lattice of L-DPPC molecules. The domain structure of L-DPPC monolayer on a hydrophilic surface is also discussed.

1,2-Dipalmitoylphosphatidylcholine↗
PubMed1993

[The effect of arotinolol on the thyroid function and the autonomic nerve systems].

beta-blockers have been accepted as a reasonable adjunct therapy for the treatment of hyperthyroidism. They lessen the sympathetic symptoms such as tachycardia and finger tremor. On the other hand, many studies have demonstrated a decrease in 3, 3', 5-triiodothyronine (T3) during treatment with beta-blockers (especially propranolol). The purpose of this study is to clarify the effect of arotinolol (alpha 1, beta-blocker) on the thyroid functions and autonomic nerve systems (ANS) of patients with Graves' disease. Arotinolol 20mg a day p.o. was given to untreated patients with Graves' disease (n = 16) for 2 weeks. Blood sampling and the ANS function-tests were done before and after the treatment. In addition, the in vitro effects of arotinolol on the cAMP production and the radioactive iodine uptake (RAIU) using rat thyroid cell line FRTL5 were evaluated to examine the direct influence on thyroid cells. Arotinolol improved hyperthyroid symptoms including tachycardia, but had no effect on ANS function-tests. It is of interest that not only T3 but also T4 decreased after the arotinolol treatment. We therefore suspected the direct suppressive effects of arotinolol on the thyroid. There were, however, no in vitro inhibitory effects on the cAMP production and the RAIU in TSH-stimulated FRTL5 cells. The reason why serum T4 levels in patients with untreated Graves' disease have decreased after the treatment of arotinolol could not be clarified. In conclusion, arotinolol is a very useful drug for the initial therapy of patients with Graves' disease to reduce the serum thyroid hormone levels and symptoms of hyperthyroidism when combined with antithyroid drugs.

Adolescent↗
PubMed1993

Anaplastic large cell lymphoma with histiocytic phenotypes.

A 38 year old man died suddenly of widespread lymphoid neoplasm after a short clinical course. Histologically the tumor was composed of pleomorphic large cells that often demonstrated phagocytic activity. Moreover, histochemical and immunohistochemical tests revealed that the tumor cells had the phenotypes of both anaplastic large cell lymphoma and histiocytic cells. Immunogenotyping failed to demonstrate any lymphoid nature. This case might be categorized as anaplastic large cell lymphoma with histiocytic phenotypes.

Adult↗