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Biomedical subjects

S Ono

Publications and source records attributed to S Ono.

At least 721 records · Page 40Linked to original sources
PubMed1986

Comparative studies on B cell reactivities in two X-linked immunodeficient mice to the B cell-stimulating factors.

Responsiveness of B cells from X-linked immunodeficient CBA/N and DBA/2Ha mice to the B cell growth factor-1 (BCGF-I or BSF-1) and B cell differentiation factors (B151-TRF1 and B151-TRF2) was comparatively studied. B cells from CBA/N mice did not respond to BSF-1 in the presence of soluble anti-mu antibody. However, the BSF-1-response of CBA/N B cells was detected when activated by the anti-mu antibody-coupled Sepharose-beads. In the B151-TRF1 assay, antigen-unprimed B cells from CBA/N mice failed to respond to B151-TRF1, whereas antigen-primed B cells became responsive to B151-TRF1. In the B151-TRF2 assay, CBA/N B cells were non-responder to B151-TRF2. In these assays, however, unprimed CBA/N B cells were able to absorb both B151-TRF1- and B151-TRF2-activities to the same extent as the non-defective strain B cells. These results indicate that B cell defect in CBA/N mice may be reflected by some abnormality in signal transmission at encounter to the B cell-stimulating factors but not by inability to bind these factors. These low responder properties of CBA/N B cells were all inherited in an X-linked recessive manner. In contrast, B cells from DBA/2Ha mice well responded to BSF-1 and B151-TRF2, whereas both antigen-unprimed and -primed DBA/2Ha B cells failed to respond to B151-TRF1. This selective B151-TRF1-unresponsiveness of DBA/2Ha B cells was also controlled by an X-linked recessive inheritance. Moreover, in contrast to CBA/N mice, selective unresponsiveness of B cells to B151-TRF1 in DBA/2Ha mice was reflected by the absence of B151-TRF1-receptor expression, as demonstrated by absorption experiment. The B cell populations found in these two distinct X-linked immunodeficient mice may provide an useful experimental model for analyzing B cell activation process mediated by various B cell stimulation factors.

Animals↗
PubMed1986

[Functional significance of left ventricular distortion in patients with right ventricular volume or pressure overloading].

To evaluate the effects of left ventricular (LV) distortion on its pump function, the LV cavity shape was analyzed by two-dimensional echocardiography in normal subjects and in patients with right ventricular (RV) volume or pressure overload. The functional significance of LV distortion in the short-axis sections was evaluated by an index of the efficiency of ejection (E) of endocardial circumferential fiber length (ECL) shortening in reducing LV cavity area during systole; E = measured systolic area reduction/ideal systolic area reduction X 100 (%), where an ideal area at end-diastole or end-systole was computed for the measured ECL, assuming its shape to be perfectly circular (ideal area = ECL2/4 pi), and then an ideal systolic area reduction was determined. E at the chordal level was termed Ech. In patients with atrial septal defect (ASD), the LV cavity was distorted at end-diastole and became more circular at end-systole. Since this characteristic change during systole diminished the E, and the values of E at the chordal level (Ech) were significantly lower in ASD than those in normal subjects (89.4 +/- 4.4% vs 98.3 +/- 0.8%, p less than 0.001), strongly suggesting impairment of the efficiency of LV pump function in ASD. In patients with pulmonary hypertension, the LV cavity was more distorted at systole, and a decrease in cavity area at end-systole with the distorted LV contributed to increased systolic area reduction. Thus, the values of Ech in this group exceeded 100% in five of nine patients (103.8 +/- 12.3%). In other words, when marked RV systolic overload exists, an increase in LV systolic area reduction due to progressive LV compression will occur against LV systolic pressure. This phenomenon suggests the existence of "cardiac massage on the LV by the RV with elevated pressure". In conclusion, it was strongly suggested that the efficiency of LV pump function is modulated by RV overload through dynamic changes in the LV shape.

Adolescent↗
PubMed1986

[General pharmacology of T-2588, a new oral cephem antibiotic].

A new oral cephem antibiotic, T-2588, the pivaloyloxymethyl ester of (+)-(6R, 7R)-7-[(Z)-2-(2-amino-4-thiazolyl)-2-methoxyiminoacetamido]-3- [(5-methyl-2H-tetrazol-2-yl)methyl]-8-oxo-5-thia-1-azabicyclo[4.2. 0]oct-2-ene-2-carboxylic acid (T-2525), is mainly absorbed from the intestinal tract and biotransformed to T-2525 thereafter. General pharmacological activities of T-2588 were studied and following results were obtained. On the central nervous system, T-2588 did not show any effects at oral doses of 500-2,000 mg/kg and T-2525 produced only a slight elevation of body temperature in rabbits without any other effects at an intravenous dose of 500 mg/kg. On the respiratory and cardiovascular systems, T-2525 caused a slight hypotension and increased both respiratory rate and femoral blood flow, but no changes were observed in heart rate and electrocardiogram in dogs at an intravenous dose of 500 mg/kg. The T-2525 exerted no significant influence on blood pressure response to isoproterenol, acetylcholine or histamine, but showed a slight tendency to decrease pressor response to adrenaline in dogs at intravenous doses of 100-500 mg/kg. For the renal function in rats, T-2588 had no effects on urine volume, electrolytes and PSP excretion at oral doses of 500-2,000 mg/kg. Intravenous administration of T-2525 caused an increase of sodium excretion at 500 mg/kg and dose-dependent increases of PSP excretion at 20-500 mg/kg. Hematological studies revealed that both T-2588 at oral doses of 500-2,000 mg/kg and T-2525 at intravenous doses of 100-500 mg/kg had no effects on bleeding time in mice, blood coagulation and platelet aggregation in rats. The T-2588 exerted no effect on the gastrointestinal system in rats or mice and had no antiinflammatory activity in rats at oral doses of 500-2,000 mg/kg. The T-2525 scarcely affected the motilities of isolated smooth muscle preparations in experimental animals including stomach, ileum, colon, uterus, vas deferens and trachea at a concentration as high as 10(-3) g/ml. The T-2525 increased bile secretion in rats at intravenous doses of 100-500 mg/kg. The T-2525 slightly decreased the twitch tension of musculus gastrocnemius induced by electrical stimulation in rats at an intravenous dose of 500 mg/kg. These results indicate that T-2588 is a pharmacologically inactive antibiotic.

Animals↗
PubMed1986

Effects of aging on the formation of ester forms of riboflavin in the rat lens.

We studied the effects of aging on the formation of ester forms of riboflavin in the lens of rats. The formation was highest in newborn and 2-week-old rats; a sharp decrease was noted at one month, thereafter it continued to decrease gradually reaching a plateau at 3 months. In general, esterification of riboflavin was higher in female than male rats. We found that a decrease in the esterification of riboflavin with increasing age is a characteristic change in the rat lens. This finding may help to clarify the pathogenesis of senescent change in the lens.

Aging↗
PubMed1985

Different recovery process of ST depression on postexercise electrocardiograms in women in standing and supine positions.

False-positive exercise test responses are frequently observed in women. To differentiate a false-positive from a true-positive test response, the effect of postures for recording a postexercise electrocardiogram to the recovery process of ST depression was investigated in 26 women with nonischemic ST depression and in 14 patients with typical angina pectoris. Exercise tests were performed twice, and the postexercise electrocardiogram was recorded while standing during the first test and in the supine position during the second test. In the false-positive test, maximal ST depression occurred immediately after exercise and showed a rapid recovery process in the early recovery phase. However, ST depression persisted without complete recovery, or increased in the late recovery phase as long as subjects were kept standing. In contrast, ST depression returned to the control level when subjects changed to the supine position after exercising. This discrepant pattern in the recovery process of ST depression by changing postures was not observed in the true-positive test results. Changing postures for recording postexercise electrocardiograms could be helpful in differentiating a false-positive response from a true ischemic response.

Adult↗