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Biomedical subjects

Y Uchida

Publications and source records attributed to Y Uchida.

At least 631 records · Page 35Linked to original sources
PubMed1986

[Effects of forskolin on canine congestive heart failure].

Forskolin is a diterpene of the labdane family which activates adenylate cyclase. The effects of forskolin were investigated in a congestive heart failure (CHF) model that we newly established using anesthetized dogs. The model was made by the intramural injection of protease into the left ventricular free wall, saline loading, and dextran and methoxamine infusion. By this maneuver, aortic blood flow (AoBF) was decreased; left atrial pressure (LAP), systemic vascular resistance (SVR) and left ventricular endodiastolic pressure (LVEDP) were markedly increased; and systemic blood pressure was unchanged. A bolus injection of 5.0 micrograms/kg forskolin reversed the hemodynamic findings of CHF. It reduced LAP (17.5----7.9 mmHg) (mean, N = 7), SVR (19980----10390 dyne sec/cm5), time constant T (90.7----59.2 msec) and LVEDP (22.8----16.8 mmHg); and it increased Vmax (2.32----2.82 l/sec) and AoBF (0.50----0.72 l/min). Forskolin improved the CHF mainly through its vasodilator and positive inotropic actions.

Animals↗
PubMed1986

Phasic contractions of canine and human coronary arteries induced by potassium channel blockers.

To gain insight into mechanisms underlying phasic coronary vasospasm in patients with variant angina pectoris, we studied whether phasic contractions could be induced in isolated canine and human coronary arteries by agents which block potassium channels. Phasic contractions of canine coronary arteries were always induced by 3,4-diaminopyridine (10(-2) M) and less frequently by 4-aminopyridine (10(-2) M). These agents also caused phasic contractions in human, swine and monkey coronary arteries and in canine basilar, carotid, renal and femoral arteries. The cycle length of phasic coronary contractions ranged from 30 sec to 1 hour, and the developed tension was 2.5 times greater than for potassium contractions. The contractions continued for more than 11 hours. Morphologically, perinuclear vacuolization, a characteristic change of vasospasm, appeared in the coronary smooth muscles. The phasic contractions were not eliminated by tetrodotoxin, atropine, phentolamine or yohimbine, but they were eliminated by nicorandil which activates potassium channels and nifedipine which blocks slow calcium channels. The results indicate that potassium channel blockers can induce phasic arterial contractions.

4-Aminopyridine↗
PubMed1986

A decrease in plasma factor which stimulates prostaglandin I2 synthesis in patients with acute myocardial infarction.

PG I2 stimulating plasma factor was measured in patients with ischemic heart disease and age-matched controls. The plasma factor measured by bioassay using rat aorta was 3.2 +/- 0.6 (n = 21), 2.7 +/- 0.8 (n = 7), 1.6 +/- 1.5*** (n = 18) and 2.2 +/- 0.06** (n = 3) PG I2 ng/mg rat aorta (mean +/- SD; * p less than 0.05, ** p less than 0.01, *** p less than 0.001) in control, angina pectoris, acute myocardial infarction and old myocardial infarction with angina pectoris groups, respectively. The plasma factor measured by radioimmunoassay was 43.5 +/- 19.5 (n = 11), 35.4 +/- 13.1 (n = 4), 38.5 +/- 18.0 (n = 9), 26.0 +/- 20.1* (n = 7) and 59.5 +/- 31.2 (n = 5) ng/mg rat aortic protein/15 min in control, variant angina, stable angina, acute myocardial infarction and old myocardial infarction groups, respectively. The factor in deproteinized plasma of the acute myocardial infarction group was also smaller than that of the control group. PG I2 synthesis by rat aortic ring was inhibited by mepacrine, which inhibits phospholipase A2. The plasma factor was not inactivated by heating. The results indicate that a heat-stable plasma factor which acts on phospholipase A2 or on its surrounding reaction systems is deficient in the early stage of acute myocardial infarction. A decrease in the factor may cause PG I2 deficiency, resulting in coronary thrombosis or vasospasm and consequently in acute myocardial infarction.

Aged↗
PubMed1986

Radioimmunoassay of c-myc protein.

A sensitive radioimmunoassay for human c-myc protein was developed by using an amino-terminal fragment of c-myc protein, c-myc(11-24). Immunoreactive c-myc protein was found to be present in 3 human tumors (HL-60, N231, Lu-65), which are known to have c-myc gene amplification. In contrast, c-myc protein was undetectable in 1 human tumor (H69) without c-myc gene amplification as well as in human heart tissues.

Cell Line↗
PubMed1986

Studies on improvement of pharmaceutical preparations prescribed in hospitals. II: Study on pharmaceutical manufacturing of dibekacin sulfate gauze tampon.

A gauze tampon, which contains an ointment incorporating dibekacin sulfate, was prepared and investigated as a device to prevent bacterial infection after operation of chronic sinusitis. It was proved that no loss of potency occurred upon heat sterilization and that it was stable even after storage for a long period. This gauze tampon was easy to insert into the paranasal sinuses, achieving satisfactory therapeutic efficacy in terms of hemostasis and disinfection. No adverse reactions have been observed.

Adult↗
PubMed1986

Studies on improvement of pharmaceutical preparations prescribed in hospitals. IV. Dibekacin sulfate viscous solution for treatment of mouth and throat wounds.

For the purpose of preventing suppuration of wounds of the oral cavity and throat, we attempted to develop a viscous solution of dibekacin sulfate (DKB) as a suitable medication. Solutions of different viscosity and antibacterial potency were prepared by mixing DKB, sodium carboxymethyl cellulose (CMC-Na), and water in varying proportions. Studies were then performed to ascertain relationships between the concentration of CMC-Na pH and viscosity, and between the viscosity and diffusion of DKB. The concentration of CMC-Na giving rise to optimal clinical efficacy was determined, and the concentration of DKB necessary for clinical treatment was estimated on the basis of the ionic binding constant between DKB and CMC-Na. As a result, the optimum CMC-Na concentration was found to be 2%, while the optimum DKB concentration was estimated to be 100 micrograms/ml.

Carboxymethylcellulose Sodium↗
PubMed1986

Pathophysiological condition of the nose of asthmatic children with subclinical nasal allergy.

Nasal mucociliary transport time, nasal hypersensitivity to histamine, the number of basophils and eosinophils in the superficial mucous layer of the inferior turbinate, and the amount of histamine in the nasal secretion were measured in the asthmatic children with subclinical nasal allergy (asthma group). These results were compared with those in nasal allergic patients with nasal symptoms (nasal allergy group). Saccharin time did not show any significant difference between the asthma and nasal allergy group. The threshold for nasal hypersensitivity to histamine was significantly higher in the asthma group than in the nasal allergy group. Accumulation of basophils and eosinophils in the superficial mucous layer of the inferior turbinate were observed in both groups. There was a statistical correlation between the number of basophils and the number of eosinophils in the superficial nasal mucosa in the nasal allergy group, but not in the asthma group. These data suggest that basophilic cell function in the superficial mucous layer in the nose is of greater significance in the development of nasal symptoms in response to nasal allergy than either mucociliary activity or nasal mucosal hypersensitivity to histamine.

Adolescent↗
PubMed1986

[Choriocarcinoma of the stomach].

A 55-year-old Japanese man was admitted to our hospital in January 1985 complaining of epigastralgia. Radiologic and endoscopic examinations showed gastric carcinoma, but biopsy specimens taken by surgery showed the histologic pattern of choriocarcinoma. On autopsy, multiple metastatic sites wer observed, and histological examination of the primary and metastatic sites revealed choriocarcinoma. Primary gastric choriocarcinoma may develop from gastric cancer by retrodifferentiation.

Biopsy↗
PubMed1985

Effects of nerve growth factor and heart cell conditioned medium on neurite regeneration of aged sympathetic neurons in culture.

The effects of nerve growth factor (NGF) and heart-cell-conditioned medium (HCM) on the neurite regeneration of aged sympathetic neurons were investigated in culture. Investigation of HCM was carried out by two different methods: one was the use of whole HCM on collagen substratum, which reflected component(s) effective in solution (HCM-S); the other was the use of polyornithine (PORN)-binding component(s) (P-HCM). Superior cervical ganglion neurons prepared from male mice from 6 to 30 months of age were cultured in MEM-10% FCS on collagen or gelatin-PORN substratum for 3 days. The number of neurons with neurites and the length of neurites were quantified as neurite production and elongation, respectively. Neuronal survival was not affected by addition of NGF, HCM-S or P-HCM. Neurite production of early adult neurons was enhanced by NGF, HCM-S or P-HCM. In contrast, neurite production of aged neurons was enhanced by only HCM-S, but not NGF or P-HCM. HCM-S did not promote neurite elongation in neurons at any age. Neurite elongation of early adult neurons was enhanced by NGF or P-HCM. Neurite elongation of aged neurons was enhanced by P-HCM. However, responsiveness of NGF for neurite elongation varied according to substrata. No age-related difference was found in neurite production and elongation in the absence of NGF, HCM-S or P-HCM. These results indicate that responsiveness of aged sympathetic neurons is various in different growth factors.

Age Factors↗