Differences in tension oscillation in aortae of hypertensive and normotensive rats.
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Acetylcholine↗
Biomedical subjects
K Shimamura
Publications and source records attributed to K Shimamura.
[The sequelae of tuberculosis].
During the 20th century, tuberculosis has been the most prevalent and most harmful disease in Japan. Enormous medical researches have ever been performed to conquer the disease. Nevertheless tuberculosis has left various somatic and psychological residues on vast convalescents. On the other hand, researches to conquer tuberculosis have made considerable contribution to other fields of medicine. 1. Somatic and psychological residues on convalescents from tuberculosis. Chest x-ray findings, cardio-pulmonary disturbance, secondary infection, serum-hepatitis due to mass transfusion during the chest surgery, streptomycin-deafness and psychological disorder. 2. Sequelae of phthisiology. a. In the field of basic medicine. Respiratory physiology, immunology and genetic pharmacology. b. In the field of epidemiology. Methodology to control the disease. c. In the field of clinical medicine. Chest x-ray diagnostics, bronchoscopy, thoracoscopy, randomized controlled trial, regimens of chemotherapy, open chest surgery, anesthesiology, treatment of respiratory failure, informed consent, terminal care and cooperative study system. d. In the field of rehabilitation. Medical, vocational and social rehabilitation of the handicapped. e. In the field of public health. Comprehensive control system of the chronic disease. Smallpox has been eradicated, but the elimination of tuberculosis is still far away. Studies as excellent as past ones should intensively be carried out.
Convalescence↗
[Pharmacokinetics of cis-diammine (glycolato) platinum (254-S), a new platinum antitumor agent, following an intravenous and intraperitoneal infusion bioactive platinum concentration profile].
The pharmacokinetics of cis-diammine (glycolato) platinum (254-S) was investigated in cancer patients following intravenous and intraperitoneal infusion. The serum concentrations of total and unbound 254-S were determined by bioassay and chemical assay as platinum. Platinum detected by bioassay was thought to be active and unchanged 254-S. Almost all of platinum in plasma were found to be active and unbound to protein because of no differences in the concentrations determined by bioassay and chemical assay and in plasma and plasma filtrate. In abdominal ascites, platinum concentrations determined by bioassay corresponded with those determined by chemical assay, suggesting that 254-S was stable in abdominal ascites. The Cmax and AUC of active 254-S in plasma determined by bioassay following an intraperitoneal infusion were about 60% and 60-80% of those following an intravenous infusion, respectively. These results showed that 254-S was well absorbed into systemic circulation from abdominal ascites as an active form. It is concluded that antitumor effect may be obtained following an intraperitoneal infusion of 254-S as well as for the reduction of abdominal ascites.
Aged↗
Blood pressure and impairment of endothelium-dependent relaxation in spontaneously hypertensive rats.
Correlation between hypertension and impairment of endothelium-dependent relaxation was demonstrated using aortae from certain strains of rats with various levels of spontaneous hypertension. It was also observed that the impairment of endothelium-dependent relaxation is the secondary change due to hypertension, and the level and duration of hypertension is the determinant factor of the impairment.
Animals↗
Neural cadherin: role in selective cell-cell adhesion.
Cadherins are a family of Ca2+-dependent intercellular adhesion molecules. Complementary DNAs encoding mouse neural cadherin (N-cadherin) were cloned, and the cell binding specificity of this molecule was examined. Mouse N-cadherin shows 92 percent similarity in amino acid sequence to the chicken homolog, while it shows 49 percent and 43 percent similarity to epithelial cadherin and to placental cadherin of the same species, respectively. In cell binding assays, mouse N-cadherin did not cross-react with other mouse cadherins, but it did cross-react with chicken N-cadherin. The results indicate that each cadherin type confers distinct adhesive specificities on different cells, and also that the specificity of N-cadherin is conserved between mammalian and avian cells.
Amino Acid Sequence↗
Acute rejection of allogeneic hemopoietic progenitors by genetically resistant mice.
Natural resistance to hemopoietic allograft results in functional elimination of the graft from the host within 24 to 48 h. The resistance is specific and is directed to the cell surface target structures of an unidentified nature. These determinants are controlled by the major histocompatibility complex-linked hemopoietic histocompatibility (Hh) loci and expressed by cells of the hemopoietic system. In this study, the susceptibility of various hemopoietic progenitors, as well as the nature and the kinetics of the early rejection process, were examined by directly following the functional survival of the grafted progenitors by periodic sampling. In both F1 hybrid and inbred allogeneic hosts, multipotential progenitors for granulocyte-erythrocyte-monocyte-megakaryocyte lineages, bipotential progenitors for granulocyte-monocyte lineages and unipotential progenitors of erythrocyte, granulocyte and monocyte were susceptible to elimination. Therefore, within the limited range of comparisons, neither the lineage, nor the degree of commitment or differentiation determines the susceptibility of hemopoietic progenitors to resistance. Functional elimination of the grafted progenitors from the recipient spleen was irreversible upon cultivation in semisolid medium. The frequency of seeding in the spleen at 3 h was comparable in resistant and susceptible hosts; elimination commenced shortly afterwards and by 24 h after transplantation less than 10% of clonogenic progenitors remained functional. Activation of natural killer cells strengthened pre-existing resistance, but did not convert genetically susceptible mice to resistant. Therefore, the resistance is dependent on an effector mechanism with predetermined specificity.
Animals↗
Electrical and mechanical properties of spontaneous contraction in hypertensive rat portal vein.
Contractile and electrical activities of longitudinal smooth muscle of portal vein from normotensive Wistar Kyoto rats (WKY) and stroke-prone spontaneously hypertensive rats (SHRSP) were compared. Amplitude and duration of spontaneous contraction of SHRSP portal vein were greater than those of WKY portal vein. No significant differences were observed in the resting membrane potentials between these preparations. Spontaneous spike activity appeared as a form of bursts. Duration of the burst and the number of spikes in each burst was greater in the portal vein of SHRSP than that of WKY. The amplitude of phasic and tonic components of K-contracture was also greater in SHRSP portal vein. Adrenergic and cholinergic nerves were not involved in the differences in contractions of the portal vein of these animal strains. Cross-sectional area of the longitudinal muscle layer was greater in SHRSP portal vein. These results suggest that the differences in spontaneous electrical activity are the cause of the differences in force and duration of the spontaneous contraction of portal vein from WKY and SHRSP, although the difference in excitation-contraction coupling of smooth muscle may be involved in much less extent.
Animals↗
An autopsy case of so-called midline malignant reticulosis followed by extensive dissemination with immunohistochemical evidence for its T cell malignancy.
An autopsy case of malignant midline reticulosis (MMR) is reported. The patient, a 42-year-old Japanese male, died after a clinical course of 22 months. Autopsy revealed extensive infiltration of generalized organs by the tumor cells, suggesting that the disease was highly malignant in nature. Staining with monoclonal antibodies against T-cell surface antigens Leu 4 on frozen sections and UCHL1 on paraffin-embedded sections enabled us to examine the phenotype of the tumor cells with good morphological preservation and to verify the T cell nature of the tumor.
Adult↗
Caffeine-induced contraction in arteries from stroke-prone spontaneously hypertensive rats.
Differences in caffeine-induced contraction in smooth muscle of resistance vessels from stroke-prone spontaneously hypertensive rats (SHRSP) and Wistar Kyoto rats (WKY) were investigated by using mesenteric artery preparations. The contraction induced by caffeine (10 mM) was greater in SHRSP preparations, both in the presence and absence of Ca (10 min after Ca removal). Caffeine-induced contraction was gradually decreased by the removal of extracellular Ca. No significant difference was observed in the time course of the decay of the contraction between SHRSP and WKY preparations, and the contraction disappeared when the time in Ca-free solution exceeded 80 min. The contraction induced by high-K-Tyrode's solution was completely abolished within 10 min after Ca removal, both in SHRSP and WKY preparations. Caffeine-induced contraction could be blocked by procaine or ryanodine. The results suggest that caffeine induces contraction by releasing Ca from sarcoplasmic reticulum, and that the release of Ca is greater in SHRSP vascular smooth muscle. It is also suggested that sarcoplasmic reticulum is leaky for stored Ca when extracellular Ca is removed, and that the rate of leakage does not differ between smooth muscle cells of SHRSP and WKY mesenteric arteries.
Animals↗
[Study on the longitudinal changes of the dental caries attack patterns of young child patients in pedodontic clinic, School of Dentistry, Ohu University].
The status of dental caries prevalence in the child patients, having visited the pedodontic clinic of Ohu University Dental Hospital, was surveyed longitudinally for 2 years (between 3 and 5 years of age) or 3 years (between 2 and 5 years). Also the dental caries attack patterns used at the dental health examination in infants aged 3 years, were investigated longitudinally. The surveyed child patients were 132 boys and 143 girls who had 20 deciduous teeth in their mouth through the surveyed period. The results were as follows: 1. The dental caries prevalence rate in the child patients was high at each age. 2. B and C caries attack patterns showing extensive caries increased remarkably at 3 or 4 years of age, and O patterns decreased with advanced age. 3. The child patients having no change in the caries attack patterns for 3 years decreased about 70%, and the severe type group transmitted to C caries attack patterns increased with advanced age. 4. Most of O caries attack patterns at 2 years of age changed to other patterns between 3 and 4 years of age, and they were few at 5 years.
Child, Preschool↗
[Discriminant analysis concerning the background factors of dental caries prevalence in young child-patients visiting the pedodontic clinic of Ohu University Dental Hospital].
In order to get the appropriate clinical information for dental caries prevention, 38 boys and 30 girls who visited the pedodontic clinic of Ohu University Dental Hospital were surveyed for 3 years, they ranged from 2 to 5 years of age. They had all deciduous teeth and were classified into 4 groups, desirable, light, moderate and severe, on the basis of the longitudinal changes of the dental caries attack patterns, after 1 year and 3 years, which is used at the dental health examination of 3-year old children in Japan. The relationships between the groups and the investigations from documents of their past history, health and usual condition of living at their first visit to the hospital were analysed by means of discriminant analysis of the first class of Hayashi's quantifying theory. The results were as follows: 1. O caries attack patterns at 2 years of age transmitted to all caries attack patterns except B patterns at 3 years, and O caries attack patterns at 3 and 4 years never transmitted to C patterns at 5 years. 2. The desirable group having no change in the caries attack patterns was 64.7%, at 2 to 3 years, but was 25.1% and decreased markedly at 2 to 5 years. The severe group transmitting to C caries attack patterns was 17.7% at 2 to 3 years, but was 42.6% and increased remarkably at 2 to 5 years.(ABSTRACT TRUNCATED AT 250 WORDS)
Child, Preschool↗
Effect of vanadate on resting membrane potential, action potential and twitch contraction in guinea-pig ureter.
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Action Potentials↗
[Cell kinetic analysis with flow cytometry as a disdifferentiation mechanism in human neuroblastoma cells in vitro].
The established cell line NB6 (human neuroblastoma) was perturbed in vitro, in order to evaluate the disdifferentiation mechanism of malignant neoplastic cells during cultivation. The methods for perturbation were as follows: 1) 50%-cell removal from dishes; 2) 0.1 mg/ml of vincristine (VCR) contact; and 3) 10Gy of beta-radiation. Specimens were harvested every 24 hours until 72 hours, simultaneously stained for DNA and RNA with acridine orange (AO), and cell kinetically analyzed for DNA/RNA/cell-distribution with the aid of flow cytometry (FCM). Thus disdifferentiated cells and/or newly cell cycle traversing cells, were evaluated. The new subpopulations were considered to be recruited from G1A and/or Gq (Darzynkieowicz et al.) into the cell cycle after perturbations. Cells of the new subpopulations had smaller volume compared with the control cells. Furthermore, in the current study, newly cell cycle traversing cells of NB6 appeared to have a disturbed cell cycle traverse in G2B phase from the clonological changing patterns of FCM cytograms. These new subpopulations were revealed to be able to passage up to five or six times. Though it was impossible to make them appear, these new cycling subpopulations might be capable of remaining as permanent clones in vitro.
Beta Particles↗
Effects of sodium vanadate on the smooth muscle of the rat portal vein.
The effects of vanadate on the mechanical and electrical activity of the rat portal vein were examined. Vanadate increased the height of the spontaneous contractions of the portal vein without affecting basal tension. This effect was not blocked by alpha-blockers or atropine. Vanadate did not exert any effect when the spontaneous contractions were abolished by high concentrations of verapamil or in the absence of Ca. Vanadate did not change the resting membrane potential of the smooth muscle cells of the vein, but it increased the rate of rise and the amplitude of the action potentials and the number of action potentials per burst. The intracellular Na content was increased slightly by vanadate. However, the effects of Na,K-pump inhibition by ouabain or K-removal were quite different from those of vanadate, and these procedures did not block the effect of vanadate, although they attenuated it. Vanadate also potentiated the K-contracture of the portal vein. These results indicate that vanadate increases the amplitude of the spontaneous contractions through an increase in the number of action potentials per burst which underly the contraction. These effects are not mediated by intrinsic nerve excitation or inhibition of Na,K pump activity. The facilitation of Ca entry through the voltage dependent Ca channel may be the main cause of the effect of vanadate on mechanical activity.
Animals↗
Extra- and intracellular calcium in vanadate-induced contraction of vascular smooth muscle.
The effects of extracellular Ca and Ca antagonists on vanadate-induced contractions of vascular smooth muscles of aortae and mesenteric arteries from rabbits, guinea pigs, and Wistar-Kyoto (WKY) and stroke-prone spontaneously hypertensive rats (SHRSP) were studied. Vanadate-induced contractions of aortae were greatly diminished by extracellular Ca removal; the size of the remaining contraction was variable. Vanadate-induced contractions of mesenteric arteries, which were only observed in the presence of elevated K, were suppressed by the removal of Ca. Verapamil and nifedipine depressed vanadate-induced contractions of aortae from WKY and SHRSP, whereas they produced no or only slight inhibition of responses in guinea pig and rabbit aortae. Ca uptake into smooth muscle cell increased in the presence of vanadate, but the increase was much less than that induced by high K. In saponin-skinned smooth muscle, vanadate depressed the Ca-induced contraction. It is concluded that the vanadate-induced contraction utilizes both extracellular and intracellularly bound Ca, the relative contribution of which varies from preparation to preparation.
Animals↗
[Studies on the development of water maze-learning ability in rats (3). Effect of the learning schedule on learning acquisition].
The effect of different learning schedules massed or distributed practice conditions (3 trials a day for 3 days), on water-filled multiple T-maze learning ability of 8-week-old SPF Wistar-Imamichi rats was investigated. Although the mean number of errors decreased day by day in both groups, the number of errors in a given day and the total number of errors in 3 days did not differ significantly between the two groups. A tendency toward a decrease in the number of errors was observed as the trials proceeded in the group with distributed practice but not in the group with massed practice. The result suggests that a certain time period for rest after each trial is necessary to acquire the memory.
Animals↗
[Immunoelectron-microscopic findings of cells concerning immunological recognition].
Recent advance in immunology is evident since the development of monoclonal antibodies and recombinant DNA techniques. Nevertheless, morphological studies in immunology is necessary to understand the mechanisms of immunological reaction in vivo and immunological disease. In this article, morphological findings mainly under immunoelectron microscopy of cells concerning immunological recognition are described. In a paragraph of peripheral bloods, findings of CD3+, CD4+, CD8+, Leu7+ and HLA-DR+ cells are shown with review of recent evidence of immunological recognition and mechanisms of CML. In a paragraph of peripheral lymphoid tissue, morphological changes of B lymphocytes in B cell proliferation are described with changes of surface markers on B cells. In a paragraph of thymus, recent knowledges about immunological tolerance and MHC restriction are reviewed with immunohistochemical findings of the cells in thymus.
Animals↗
Chromosome abnormalities in malignant lymphoma in patients from Saitama.
Clonal chromosome abnormalities were found in 89 (97%) of 92 patients with non-Hodgkin's malignant lymphoma including immunologically determined 34 B- and 25 T-lymphomas; only 3 of 19 T-lymphoma patients examined had serum adult T-cell leukemia/lymphoma-associated antigen antibody. Association of 8q24 translocations with small non-cleaved cell (P less than 0.01) and that of t(14;18) (q32;q21) with follicular histology (P = 0.03) were significant. Several other abnormalities were also found to be correlated with histological or immunological phenotypes: trisomy 5 with diffuse, mixed cell lymphoma (P = 0.03); a break at 3q21 with diffuse, large cell lymphoma (P = 0.04); gain of chromosome 18 or X and rearrangements of 13q with immunoblastic lymphoma (P = 0.02, 0.03, and 0.03, respectively); and rearrangements of 7q with diffuse large cell histology (P = 0.02) and T-cell phenotype (P = 0.02). Multiple clones were more frequently seen in T-cell lymphoma than in B-cell lymphoma (P = 0.01). Structural changes of the long arm of chromosome 4 or 15 and a break in 6p21 were also associated with T-lymphoma (P = 0.03, respectively). Since the frequency of T-lymphoma is significantly higher and that of t(14;18) is significantly lower in the adult T-cell leukemia/lymphoma nonendemic area of Saitama in Japan than in Minnesota in the United States (P less than 0.01), factors affecting the lymphoma-genesis may be different or operating in different intensities in different areas.
Adolescent↗