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Biomedical subjects

H Ohno

Publications and source records attributed to H Ohno.

At least 415 records · Page 23Linked to original sources
PubMed1990

Intracoronary endothelin-1 increases coronary retrograde pressure by constricting arterioles.

STUDY OBJECTIVE: The aim was to determine the site of coronary vasoconstriction induced by endothelin, by investigating the response in terms of retrograde pressure and reactive hyperaemia. EXPERIMENTAL MATERIAL: Twelve anaesthetised mongrel dogs, 12-14 kg, were used for the studies. DESIGN: The left anterior descending coronary artery was cannulated and perfused with blood through an extracorporeal bypass. The effects of intracoronary endothelin-1 (1-500 pmol) on coronary blood flow, coronary flow reserve (the peak reactive flow and the repayment after 15 s coronary occlusion), and retrograde coronary pressure during coronary occlusion were studied (n = 7). The retrograde coronary flow was collected from the bypass at each dose (n = 5). MEASUREMENTS AND MAIN RESULTS: At doses of greater than 20 pmol the coronary flow decreased dose dependently and reached almost zero flow at 500 pmol. The coronary flow reserve also decreased; however, the retrograde pressure was raised dose dependently at doses of greater than 10 pmol. At a dose of 500 pmol, the retrograde pressure was increased to 61 mm Hg [82(SEM 12)% of the coronary perfusion pressure]. Retrograde flow remained unchanged throughout the experiment. CONCLUSIONS: The endothelin-1 induced rise in retrograde pressure is in accordance with a dose dependent reduction in coronary flow reserve, and collateral flow was not augmented by endothelin. It is concluded that the effect of endothelin-1 on coronary circulation in situ was mainly due to the constriction of small resistant vessels.

Animals↗
PubMed1990

CD3 zeta and eta chains are produced by alternative splicing from a common gene.

We have analyzed the genomic organization of the murine CD3 eta gene. As suggested from the sequence of CD3 eta cDNA, exons I-VII are identical to those of CD3 zeta and exon VIII is a unique exon for CD3 eta. Exon VIII of the CD3 eta gene is located 4 kb downstream of exon VIII of the CD3 zeta gene. Together with the existence of a splicing acceptor site just before exon VIII of the CD3 eta gene, the CD3 eta chain is proved to be produced by an alternatively spliced transcript of the common gene of CD3 zeta and eta. Since T cell receptor complex contains two forms of zeta dimers, zeta-zeta and zeta-eta, on a single T cell, which seem to have different functions, the results indicate the importance of analyzing the regulation of the alternative splicing to understand T cell function.

Animals↗
PubMed1990

Effect of phospholipase A2 inhibitors on mouse T lymphocytes. II. Phospholipase A2 inhibitors induce T cell hybridomas and a T cell clone for the formation of glycosylation-inhibiting factor.

The mouse T cell hybridoma 12H5 cells constitutively form glycosylation-enhancing factor (GEF) and produce both IgE-potentiating factor and ovalbumin (OVA)-binding GEF upon antigenic stimulation with OVA-pulsed macrophages. Culture of the 12H5 cells either with nonspecific glycosylation inhibiting factor (GIF) or with a phospholipase A2 (PLA2) inhibitor, ONO-RS-082, stopped the formation of GEF and induced the same cells to form GIF. Induction of the GIF formation by a PLA2 inhibitor was observed even when the 12H5 cells had been treated with mitomycin C, indicating that the switching from the GEF formation to the GIF formation was not due to selective proliferation of a GIF-producing subclone. The OVA-binding GIF produced by the PLA2-inhibitor-treated, antigen-stimulated 12H5 cells binds to homologous antigen (ovalbumin), and shares both antigenic determinant recognized by the monoclonal antibody 14-30 and the lipomodulin-determinant with antigen-specific suppressor inducer factor (TsiF). The present experiments also showed that a typical helper T cell clone, D10, G4.1 cells, constitutively formed GEF and that preculture of the T cell clone with IL-2 and the PLA2 inhibitor switched the cells from the formation of GEF to the formation of GIF. Upon stimulation with antigen-pulsed macrophages, the inhibitor-treated D10.G4.1 cells formed GIF having affinity for conalbumin. The results indicated that the same T cells have the capacity to form either GIF or GEF under different conditions, and suggested that the GIF-producing suppressor T cells may be a phenotype of a subset of helper T cells. Switching of the same cells from the GEF formation to the GIF formation by the PLA2 inhibitor and the ability of the inhibitor to enhance GIF formation suggested that PLA2-inhibitory activity or GIF activity of TsiF is involved in the suppressor T cell cascade.

Aminobenzoates↗
PubMed1990

Endothelin family in human plasma and cerebrospinal fluid.

To clarify whether endothelin may be present in human cerebrospinal fluid (CSF) and, if it exists, to compare its molecular forms with those of endothelin in human plasma, we analyzed pooled human CSF and plasma by high performance liquid chromatography with specific enzyme immunoassays for each endothelin peptide. Of the four human endothelin peptides hitherto identified, big endothelin-1 was the major molecular form of endothelin present in human CSF. In addition, there was a small but significant amount of endothelin-1 and endothelin-3 in CSF, while endothelin-2 was not detectable. Similarly, big endothelin-1, endothelin-1, and endothelin-3 were identified in human plasma. Although big endothelin-1 was the most abundant, a substantial amount of endothelin-1 and endothelin-3 was found in plasma with a resultant lower molar ratio of big endothelin-1 to endothelin-1 than in CSF. In all CSF samples from 17 patients requiring diagnostic lumbar puncture or lumbar anesthesia, endothelin was detectable, with a preponderance of big endothelin-1 relative to endothelin-1 and endothelin-3. The mean concentrations of endothelin-1 and endothelin-3 in simultaneously collected plasma were significantly (P less than 0.01) higher than those in CSF, while there was no significant difference between the mean big endothelin-1 concentration in plasma and that in CSF. There was no significant correlation among concentrations of big endothelin-1, endothelin-1, and endothelin-3 in each paired sample. These results indicate that endothelin is present in human CSF that is differently processed from endothelin in vascular endothelial cells and suggest a possible role for endothelin as a modulator of neuronal functions.

Adult↗
PubMed1990

[Quantitative assessment of gastric mucosal bleeding in the development of acute gastric mucosal lesions in the rat and prophylactic effect of elcatonin].

Intraperitoneal injection of indomethacin (5, 10 and 20 mg/kg) caused acute gastric mucosal lesions in the conscious restrained rat and also hypersecretion of gastric acid. Cimetidine, an H2-receptor antagonist, was found to prevent gastric mucosal bleeding and acid secretion induced by indomethacin. Elcatonin at higher doses than 2.5 U/kg (0.5 microgram/kg) was effective for protecting the gastric mucosa against indomethacin irritation, and it inhibited acid output in response to this ulcerogen. The acid inhibitory effect of elcatonin might be implicated in its cytoprotective action.

Animals↗
PubMed1990

[Effects of flutropium bromide, a new anti-asthma drug, alone or in combination with salbutamol, aminophylline and disodium cromoglycate on the acetylcholine induced bronchoconstriction].

Effects of flutropium bromide, a new bronchodilator with an anticholinergic action, alone or in combination with other antiasthma drugs were investigated in guinea pigs by using an index of inhibition of the acetylcholine (ACh)-induced bronchoconstriction. Single inhalation of flutropium bromide (0.0003%) into the airways of guinea pigs inhibited the ACh (i.v.)-induced bronchoconstriction without changing the fall in blood pressure induced by ACh. When salbutamol (3 micrograms/kg, i.v.), aminophylline (5 mg/kg, i.v.) or disodium cromoglycate (10 mg/kg, i.v.) was administered in combination with flutropium bromide (0.0003%), bronchodilation was enhanced as compared with single administration of the respective antiasthma drugs. From the above results, it is indicated that inhalation of flutropium bromide provides a more efficient bronchodilation in combination with other antiasthma drugs that possess different mechanisms of antiasthma effects.

Acetylcholine↗
PubMed1990

Antiulcer activity of eel-calcitonin (elcatonin) is associated with enhanced gastric mucosal PGE2 generation in the rat.

Elcatonin is a newly synthetized peptide that prevents experimental ulcer formation. In this study, we examined the influence of elcatonin on endogenous prostaglandin biosynthesis by the gastric mucosa with respect to its antiulcer activity. Control levels of PGE2 generation for the fundic and antral mucosa were 302 +/- 12 and 465 +/- 28 ng/g tissue/min, respectively. Pretreatment with elcatonin resulted in a dose-dependent increment in gastric mucosal PGE2 generation. We conclude that the antiulcer effect of elcatonin is probably due to its ability to enhance endogenous prostaglandin synthesis in the gastric mucosa.

Animals↗
PubMed1990

Effect of L-cysteine on distribution volume of 1-(tetrahydro-2-furanyl)-5-fluorouracil.

Higher plasma concentrations of 1-(tetrahydro-2-furanyl)-5-fluorouracil (FT) were obtained after administration of FT (100 mg/kg, i.v.) combined with L-cysteine (CySH, 500 mg/kg, p.o.). The volume of distribution (Vd) and body fluid volumes significantly decreased. These results suggest that the increase of the plasma concentrations of FT can be attributed to the decrease of the Vd of FT, which is considered to be based on the decrease of body fluid volumes by the combined administration of CySH.

Animals↗
PubMed1990

[Effects of cefpirome sulfate on male sexual development in rats].

Cefpirome sulfate (CPR) was administered subcutaneously at 200, 500, and 1000 mg/kg/day to male rats for 5 weeks from 6 through 40 days of age and examinations were made to determine whether the antibiotic caused any detrimental effects on male sexual development when administered to juvenile rats. Cefotetan (CTT) was given at 1000 mg/kg/day as a positive control. Incrustation occurred at the injection site during administration in all treated groups. The CPR groups had no compound related changes in fertility, spermatozoa, and reproductive organs, while the CTT group showed decreased testicular weight, abnormal fertility and spermatozoa, and atrophied germinal epithelium of seminiferous tubules, atrophied epididymis, and decreased number of spermatozoa. From the results of this investigation, it may be concluded that CPR had no effects on male sexual development when administered to juvenile rats.

Animals↗
PubMed1990

New conversion method of metal surfaces for resin bonding. Conversion effects for pure metals in dental precious metal alloys.

Excellent adhesion of adhesives to metals can be realized by simply applying liquid Ga-Sn alloy (Adlloy) on the adherend metal surface. This method is only effective on dental precious metal alloys. Five metals, Au, Pt, Pd, Ag, and Cu, included in dental precious metal alloys were converted by this method to determine the most effective pure metal from bonding strength measurements, water durability at the adhesion interface, and ESCA measurements. All metals converted by Adlloy showed excellent bonding strength and water durability, whereas nonconverted metals showed poor water durability. ESCA measurements showed that metal surfaces converted by Adlloy are covered with a 3-6 nm thick Ga and Sn oxide film and that the diffusibilities of Ga in the metals are in the order Ag greater than Au greater than Pt greater than Cu greater than Pd. From the viewpoint of handling, Ag is the most effective metal.

Acrylic Resins↗
PubMed1990

Training effects on blood zinc levels in humans.

Effects of physical training on fasting erythrocyte and plasma zinc distributions were studied on seven previously sedentary male students. The training consisted of running over 5 km, 6 times/week for 10 weeks. Maximum aerobic capacity (VO2max) and 12 min walk-run performance increased significantly (p less than 0.01) after training. The erythrocyte concentrations of total zinc and of zinc derived from carbonic anhydrase I (CA-I) rose significantly (p less than 0.05) after training, whereas no such effects were noted in CA-II-derived zinc, Cu2Zn2 superoxide dismutase-derived zinc, and other zinc. On the other hand, no effect of training was found in total or alpha 2-macroglobulin-bound zinc in plasma, although albumin-bound zinc concentration declined significantly (p less than 0.05). Following the training period, however, the response to a VO2max test of the van Beaumont quotient (J Appl Physiol 1973;34:102-6) for total plasma zinc had decreased significantly (p less than 0.05), suggesting a relative reduction of the circulating exchangeable zinc. In addition, there were significant (p less than 0.05) decreases in plasma iron and ferritin concentrations after training, indicating latent iron deficiency anemia. These results may suggest that the changes in CA-I-derived zinc and/or albumin-bound zinc portend zinc deficiency during running training and that sports anemia precedes hypozincemia in athletes.

Adolescent↗
PubMed1990

[Toxic activities of the Ga-Sn alloy (Adlloy-OH) on nutritional condition and dental caries development in rats].

The toxic activities of Ga-Sn alloy (Adlloy-OH) in experimental rats, its relations to the nutritional condition and dental caries development, were studied for three months. Adlloy, 0.3 g or 3 g per body weight (kg), was fed orally with the basal diet consisting of casein, sucrose, bean oil, mineral, and vitamin mixtures. Biochemical assays of serum was carried out for total protein, albumin, calcium, inorganic phosphate, glucose, urea, creatine, alkaline phosphatase, GOT, and GPT. There was no convincing evidence of toxic effects on growth and biochemical data by the oral feeding of Addloy-OH.

Animals↗
PubMed1990

[The trends of the TMJ patients on dental clinic of pediatric dentistry. Comparison finished patients with discontinued patients by questionnaire].

We made a follow-up survey on the TMJ dysfunction syndrome patients who visited our clinic, using questionnaires for the purpose of raising the dental management of TMJ dysfunction syndrome patients and obtained as following results. 1. The percentage of questionnaires which were sent back was 61.5% with the finished group, and was 38.9% with the discontinued group. The average percentage for all subjects was 50.7%. 2. From the results from all subjects who answered the questionnaire and sent them back, it was found that the ratio of the patients who had understanding of the explanation before the treatment of the TMJ dysfunction syndrome was 60.5%. The ratio of the patients who answered "I could not use the splint completely" was 2.6%, and the ratio of the patients who answered "I used the splint completely in spite of malaise when using it" was 84.2%. The ratio of the patients who answered "I felt that treat time was long" was 57.9%. The ratio of the patients who had a relapse of the symptom after treatment was 33.3%, but 22.2% of their symptoms were temporary and soon disappeared. 3. There were 4 questions which showed statistical significant differences between the finished group and the discontinued group. They were the attitude to the treatment after examination at first visit, period of time the splint was used, complaint of discomfort while using the splint, concerned mind of visiting interval. 4. The rate of the patients who complained of the limitation of jaw at the first time was higher with the finished group than with the discontinued group.

Child↗
PubMed1990

[A study of active induction of orthodontic therapy in TMJ dysfunction syndrome--from the data of patients with TMJ dysfunction in adolescents].

It seems that active orthodontic therapy using multi-bracket appliances presents effective assurance of a physiological stable occlusion for TMJ dysfunction syndrome in adolescents. The efficiency and problems concerning the progress of active orthodontic therapy after splint therapy were examined from the data of the change of occlusal conditions, and the function of masticatory muscles before and after therapy for TMJ dysfunction from four cases for which we performed orthodontic therapy activity. 1. All of the occurring symptoms of the TMJ dysfunction syndrome (limitation, pain, sound) in the progress of orthodontic therapy were concerned with using intermaxillary elastic. The symptom which occurred in process of using only intra-maxillary elastic was just a malaise of the TMJ. Also the sound of the TMJ relapsed in the process of using class III intermaxillary elastic and recurred after the multi-bracket appliance was removed. In this case, the condylar vertical position after orthodontic therapy changed from the lower position to the center position compared with the first visit. 2. Malocclusion was improved with orthodontic therapy in all four patients. 3. The function of the masticatory muscles after orthodontic therapy was improved in comparison with the first visit by evaluation of the masticatory muscles activity and the state of silent period.

Adolescent↗
PubMed1990

[Cerebral blood flow in infants: comparison of carotid blood flow and cerebral blood velocity].

Carotid blood was measured with a ultrasonic volume flow meter in 38 infants. The carotid blood flow was 1.50 +/- 0.55 ml/sec. At the same time peak systolic flow velocity, mean blood velocity, end diastolic velocity, pulsatility index (PI) and resistance index (RI) in the middle and anterior cerebral arteries were measured by duplex Doppler scanning. There was a correlation between the carotid blood flow and the mean blood velocity in middle and anterior cerebral arteries. However, PI and RI were not well correlated with carotid blood flow.

Blood Flow Velocity↗