Search PubMed⌕ Search

Biomedical subjects

F Saito

Publications and source records attributed to F Saito.

At least 109 records · Page 6Linked to original sources
PubMed1990

Syntheses and biological activities of renin inhibitors containing statine analogues.

Syntheses and biological activities of dipeptide renin inhibitors that contain statine analogues are described. The key steps of the synthetic approach to dipeptide renin inhibitors are the asymmetric synthesis of 2(R)-substituted-3-aminocarbonylpropionic acids and the diastereoselective syntheses of (3S,4S)-statine analogues. These inhibitors (2,14-40) inhibited human renin in the 3-140 nM range. Inhibitor ES 6864 (2) was found to be a highly potent inhibitor of human renin (IC50: 4.6 x 10(-9) M) and showed high enzyme specificity. Oral administration of ES 6864 at 3 mg/kg to conscious, sodium-depleted marmosets inhibited plasma renin activity (PRA) more than 80% after 1 h.

Amino Acids↗
PubMed1990

[Studies on the mechanisms of action of disopyramide on insulin secretion. The modification by high glucose solution].

Using the islet perifusion preparation and the isolated rat pancreas in situ perfusion preparation, the effects of disopyramide (Diso) on insulin secretion were studied. In an isolated pancreatic islet perifusion experiment, Diso (300 micrograms/ml) produced a significant increase in the immunoreactive insulin (IRI) level in the perfusate. The Diso-induced IRI rise was not affected by pretreatment with various autonomic blocking agents, such as propranolol, phentolamine or atropine. In an isolated rat pancreas in situ perfusion experiment, the IRI level in the perfusate increased significantly after the administration of Diso (300 micrograms/0.1 ml) under the perfusion of Krebs-Ringer bicarbonate buffer solution containing 0.3% glucose (0.3% glucose buffer), but not under the perfusion of Krebs-Ringer bicarbonate buffer solution containing 0.1% glucose (0.1% glucose buffer). The Diso-induced IRI rise was not affected by pretreatment with the autonomic blocking agents. Diso suppressed the IRI rise which was induced by additional glucose application (25%, 0.2 ml) under the perfusion of 0.1% glucose buffer, but not under the perfusion of 0.3% glucose buffer. Furthermore, Diso also suppressed the hypersecretion of insulin induced by increasing the glucose concentration from 0.1% to 0.3% in the perfusion fluid. The suppressing action of Diso on glucose-stimulated insulin secretion was partially recovered after pretreatment with propranolol or phentolamine. These findings show that Diso has both stimulatory and inhibitory effects on insulin secretion processes, and that the inhibitory action of Diso is suppressed by high glucose solution.

Animals↗
PubMed1990

[A consideration of determining the removal or retention of teeth in the patient with a few remained teeth].

The alveolar bone of edentulous ridge is resorbed after the teeth extraction and the subsequent denture insertion. For the periodontal structure, the stress transmitted along the longitudinal axis is favorable, but the horizontal stress is destructive. Under the overdenture application which the retained teeth have the reduced clinical crown, it is possible to prevent the alveolar bone resorption and to improve the involved teeth. However it is difficult for the inclined teeth to get the successful results. In a case, having a few remained teeth contained the embedded root stump and the overdenture being applicated, we obtained the suggestion as follows. 1. Also the embedded root stump is useful to prevent the alveolar bone resorption. 2. The top and direction of longitudinal axes of the inclined abutment teeth can be determined by means of surveying the least teeth movement when the stress was applied to the teeth by the fingers with dental pincette. 3. Also to the inclined abutment teeth, it is possible to transmit the stress along the longitudinal axes, when the overdenture has the contact with the short dome coping at the top and in the inferior area to the longitudinal axes inclined, and is relieved in the superior area to its axes.

Alveolar Bone Loss↗
PubMed1990

[Clinical study of ectopic eruption of the permanent first molars].

The purpose of this study was to investigate the etiology and characteristics of the ectopic eruption of first permanent molars. The subjects were 35 cases (27 maxilla and 8 mandible) with ectopically erupted permanent first molars, which were recognized in 24 out-patients (10 boys and 14 girls) visiting Tohoku University, Dental Hospital. The materials used for the analysis were dental casts, X-ray lateral cephalograms and panoramic radiographs, and both materials of the ectopic and normal groups were compared. The results were as follows: 1) There were no significant differences statistically between the mesio-distal crown diameters of the maxillary permanent first molar, central and lateral incisor, and all deciduous teeth in ectopic group and their mean values in Ono's and Otsubo's studies. 2) There were no significant differences as compared to all parts of the size of the dental arch in ectopic sides with those in the normal sides of same individuals at IIA and IIC of Hellman's developmental stage in dentition. 3) When the sizes of the dental arch in the ectopic group were compared with those of the normal group, the former were smaller at the distance between the mid-point and the canine mesial surface (Fig. 1-4), the ridge of the posterior region of the basal arch and most distal point of the primary second molar (Fig. 1-6) at the Hellman's dental age IIA, while the canine distance to the midline (Fig. 1-1), the dental arch perimeter from mid-point to the distal surface of primary second molar (Fig. 1-4+5), and the distance between the canine and primary second molar, div. X (Fig. 1-7) at Hellman's dental age of IIC were significantly smaller than the latter. 4) Regarding the comparison of the value of the changes in dental arch size between the ectopic group and the normal group from Hellman's dental age of IIA to IIC, the distance between the canine and primary second molar, div. X (Fig. 1-7) decreased markedly and the distance between the ridge of the posterior region of the basal arch and the most distal point of the primary second molar (Fig. 1-6) increased. 5) Results of the analysis of X-ray lateral cephalograms showed that the angle of eruption of first molars in the ectopic group was significantly smaller compared with normal group. 6) According to the cluster analysis on the calcification of tooth germ using panoramic radiographs, similarity among all of the samples was lacking in the ectopic group, especially congenital missing of the second molars and second premolars in the ectopic side and the delayed calcification of the ectopically erupted teeth were found in maxilla.

Child↗
PubMed1989

Evaluation by exercise Doppler echocardiography of maintenance of cardiac output during ventricular pacing with or without chronotropic response.

To examine the effectiveness of activity-initiated rate-responsive pacing, this study assessed the increases in stroke volume and cardiac output during randomized treadmill exercise in rate-responsive and fixed-rate ventricular (VVI) pacing in 10 patients. Stroke volume index and cardiac index were determined by suprasternal Doppler measurements. Compared with the findings during VVI pacing, the rate-responsive pacing was associated with (1) prolongation of exercise duration (8.0 +/- 4.0 vs 7.3 +/- 3.6 minutes, p less than 0.05); (2) greater exercise-induced positive chronotropic response (mean maximal heart rate 127 +/- 12 vs 78 +/- 15 beats/min, p less than 0.001); (3) smaller increase in stroke volume index (38 +/- 10 vs 50 +/- 11 ml/m2, p less than 0.001), and (4) greater increase in cardiac index (4.7 +/- 1.1 vs 3.9 +/- 1.0 liters/min/m2, p less than 0.001). A significant correlation was observed between age and percent increase in stroke volume index during VVI pacing (p less than 0.05). These findings indicate that VVI pacing increased stroke volume more than did rate-responsive pacing, especially in younger patients, but the increase in cardiac output was less than that seen with rate-responsive pacing due to the absence of chronotropic response. Accordingly, an activity-sensing, rate-responsive pacemaker can effectively increase the heart rate, significantly augment cardiac output and extend the duration of exercise.

Adult↗
PubMed1989

Localization of coronary artery narrowings by applying R-wave amplitude correction to exercise-induced ST depression in angina pectoris and single-vessel coronary artery narrowing.

This study investigated whether coronary artery narrowings can be localized by applying R-wave amplitude correction to exercise-induced ST depression in multiple unipolar precordial lead electrocardiography using 20 electrodes covering the left chest wall. Ten normal subjects and 29 patients with stable angina pectoris and single-vessel coronary artery narrowing (greater than or equal to 75% luminal diameter stenosis in only 1-vessel) participated. Of the 29 patients, 5 had left main coronary artery disease (CAD), 14 had left anterior descending CAD, 4 had right CAD and 6 had left circumflex CAD. The exercise-induced ST depression with R-wave amplitude correction was defined as the exercise-induced ST depression divided by the R-wave amplitude. The 20 points of the lead system were divided into 4 areas: the left main, left anterior descending, right and left circumflex coronary arteries. Coronary artery narrowing was supposed to be in an artery corresponding to the area where the maximal value of the exercise-induced ST depression with and without R-wave amplitude correction was situated. By applying R-wave amplitude correction, the diagnostic ability of localization of coronary artery narrowings was improved significantly from 52% to 86% (p less than 0.005). In particular, localization of the left main coronary artery narrowing was correctly diagnosed in 100% (5 of 5) of angina pectoris patients with left main CAD.

Aged↗
PubMed1989

Giant cell pneumonia caused by varicella zoster virus in a neonate.

A premature male neonate, born at the 25th gestational week, developed pneumonia six days after delivery and died. Postmortem examination of the lungs revealed giant cell pneumonia with intranuclear inclusion bodies; varicella zoster infection was confirmed by immunoperoxidase stain using monoclonal antibody to varicella zoster virus and electron microscopic examination. In previously reported necropsy cases of numerous giant-cell formation in the lung is not mentioned. Therefore, the unusual features prompting this report include the absence of skin lesions in this mother and infant and the presence of giant cell pneumonia, not previously reported in varicella zoster infection.

Antibodies, Monoclonal↗
PubMed1988

Radiation injury in a patient with unusually high sensitivity to radiation.

Radiation therapy is usually given with the assumption that interindividual variations in radiosensitivity are small, except for some patients with hereditary diseases associated with increased sensitivity. Recently, we observed radiation induced pericarditis in a breast carcinoma patient, in whom clinical signs, blood counts and chromosome analysis after in vitro irradiation of blood suggested a state of unusually high radiosensitivity. No evidence of constitutional chromosome abnormality was found in karyotypic analysis with the G-banding technique.

Breast Neoplasms↗
PubMed1988

Analysis of factors affecting year-round performance of Single Comb White Leghorn laying hens reared under an open-sided housing system.

Based upon a field survey, an analysis was made to clarify factors affecting year-round performance of laying hens reared within an open-sided housing system. Data were collected from flocks located in Kumagaya city (36 degrees N, Japan), where they were subjected to periodic seasonal changes in photoperiod and ambient temperature specific to that area. Monthly performance of Single Comb White Leghorn laying hens at 5 to 16 mo of age was recorded and analyzed in terms of month of hatch, ambient temperature, and age. Changes in egg production and daily egg mass coincided with those in natural daylength. Egg weight was significantly lower in June-hatched layers; egg mass was highest in May and lowest in December hatches. Feed, CP, and ME intakes showed opposite periodic changes to that of ambient temperature with various delay times: ME intake showed no delay, whereas feed and CP intakes had 18 and 29-day delays, respectively. By comparing the performances of April to June and September to November-hatched hens, it was found that natural photoperiod appeared to be more important than ambient temperature in egg production, and that the effect of natural photoperiod became small and insignificant as the bird aged. The effect of temperature on egg production rate was found to be dependent on age of laying hens, i.e., it was more evident in old birds, especially when birds were exposed to a cold climate. Apparent age-dependent changes in the periodic element of egg production rate as related to calendar month were also shown.

Animals↗
PubMed1988

Quantitative estimation of dietary intake in patients on hemodialysis.

A simple method to calculate the amount of dietary (protein, sodium and potassium) intake in hemodialyzed patients was developed. In 8 nutritionally stable patients, the amount of dietary intake was monitored conventionally by a dietary record method. In contrast, assuming that the amount of dietary intake was equal to the amount of accumulation in the body, the former was calculated as the change in the product of serum concentrations and total body fluid volume, which was estimated based on the sex and body build of each patient. The urea accumulation was converted to the protein intake. The interdialytic dietary protein and sodium intake calculated by this method, 120 +/- 10 g and 240 +/- 40 mEq, respectively, was not significantly different from that obtained by the dietary record, while the interdialytic potassium accumulation, 60 +/- 7 mEq, was significantly smaller than the dietary intake, 110 +/- 9 mEq, obtained by the record method, though the correlation was significant. Thus, the amount of protein and sodium intake can be calculated simply without diet research or body fluid volume measurements. Although potassium intake can not be calculated exactly because of intestinal loss, this simple method gives us a rough estimate. In addition, multiple regression analysis showed that the amount of energy intake obtained by the record method may be explained by the protein and sodium intake estimated by simple calculation.

Blood Urea Nitrogen↗