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Biomedical subjects

S Arai

Publications and source records attributed to S Arai.

At least 415 records · Page 23Linked to original sources
PubMed1982

Induction of immunoglobulin-producing human peripheral blood lymphocytes in serum-free medium.

Induction of immunoglobulin-secreting cells from human peripheral blood lymphocytes in a serum-free culture medium was studied. Albumin, transferrin, insulin and fibronectin can replace serum entirely for support of pokeweed mitogen (PWM)-stimulated B lymphocytes, measured by a reverse hemolytic plaque assay using protein A-coated red cells. In this serum-free system, growth and maturation to IgM and IgG secretion occur at the same or higher efficiency as in conventional serum-containing medium, with maximum numbers of plaque-forming cells on day 6 at optimal dose of PWM, 0.5-5 micrograms/ml. This system can be used to avoid the interference from undefined serum components.

Animals↗
PubMed1982

Absence of Carp's agent in sera of patients with multiple sclerosis in Japan.

A study was devised to test for Carp's agent in the sera of Japanese patients with multiple sclerosis (MS). The sera were obtained from 17 patients with definite MS and six patients with possible MS. Strain C3H mice were given an intraperitoneal injection of 0.1 mL of each serum. One week before and 1, 3, and 6 weeks after inoculation, blood drops from tail tip were smeared and polymorphonuclear leukocytes (PMNLs) were counted. Although the experimental animals were kept under careful control, substantial fluctuation in the number of PMNLs occurred, and the variations of PMNL count in the experimental groups were all within the normal range. We conclude that there is no Carp's agent in the sera of patients with MS in Japan.

Animals↗
PubMed1982

The stress-strain relationship of the diastolic cardiac muscle and left ventricular compliance in the pressure-overload canine heart.

The relation between left ventricular (LV) compliance, chamber geometry and LV muscle compliance in pressure-overload hearts was studied. The diastolic pressure (P)-volume (V) relationship was evaluated at different ventricular volumes of isovolumic beat in 4 pressure-overload hypertrophied (H) and 5 normal (N) hearts. In H, the ratio of the LV volume at the EDP of 15 mmHg to LV weight (LVW) was 0.34 +/- 0.08 (SD) ml/g (N: 0.63 +/- 0.07, p less than 0.01). Thus the occurrence of concentric hypertrophy due to pressure-over-load was confirmed. The P-V relation was expressed as, delta V = a - b.exp (-cP), where a, b and c were constants, delta V = V - V0, and V0 was the initial volume at EDP = 0 cmH2O. Since this equation leads to the relation: d delta V/dP = c (a - delta V), c may be regarded as a parameter which represents the LV chamber compliance. In H, c was 0.074 +/- 0.024 (SD) mmHg-1 (N: 0.109 +/- 0.008 mmHg-1, p less than 0.01). Therefore, H was found to show decrease of LV compliance. The biaxial stress (sigma)-strain (epsilon) relation was derived from the P-V relation based on large deformation theory. The sigma-epsilon relationships of myocardium in H were not apparently different from that in N. However, there was a close correlation between c and LV volume (at EDP = 15 mmHg)/LVW (r = 0.83). Thus it was found that the change in LV compliance in H resulted from the change in LV chamber geometry.

Animals↗
PubMed1982

Iron-containing proteins augment responses of human lymphocytes to phytohemagglutinin and pokeweek mitogen in serum-free medium.

The effects of various iron-containing compounds on the responses of human peripheral lymphocytes to phytohemagglutinin (PHA) and pokeweed mitogen (PWM) were studied in serum-free medium supplemented with bovine serum albumin. Hemoglobin, transferrin and ferritin enhanced the incorporation of 3H-thymidine into DNA after PHA-stimulation of lymphocytes, while hemin, iron metal powder, ferrous sulfate, chromium powder, and zinc sulfate have little effect. The response to PWM, measured by plaque formation, was enhanced only by transferrin. Desferrioxamine, a chelating agent specific for ferric iron, completely removed these augmentative effects. The results indicate that iron-containing proteins influenced the responses of lymphocytes to stimulation by PHA and PWM in serum-free medium.

Culture Media↗
PubMed1982

Antihypertensive effect of nicardipine hydrochloride in essential hypertension.

The antihypertensive effect of a new calcium antagonist, nicardipine hydrochloride (YC-93), was studied in 47 mild to moderate essential hypertensives. YC-93 (30-60 mg/day) was administered orally alone for 8 weeks (Group I, 31 patients) or in combination with diuretics, beta blockers, or both (Group II, 16 patients). Blood pressure was reduced from 173.6 +/- 2.2/103.5 +/- 1.7 to 139.7 +/- 2.0/87.2 +/- 1.1 mmHg in Group I and from 172.9 +/- 3.9/108.9 +/- 2.9 to 140.5 +/- 2.3/89.5 +/- 2.5 mm Hg in Group II. Pulse rate was not altered in Group I but increased transiently in Group II. The side effects seen in seven patients were mostly related to the vasodilatation and were generally transient and mild. These results indicate that YC-93 is an effective antihypertensive drug for the treatment of essential hypertension.

Adult↗
PubMed1982

[Experience with high-dose methotrexate therapy for malignant solid tumors].

Thirteen patients with malignant solid tumors, mainly osteogenic sarcomas, were treated by high-dose MTX therapy, 50-400 mg/kg, in a total of 72 cycles. It has been proved that this therapy was relatively safe provided careful clinical surveillance were assured. Of 8 patients with osteogenic sarcomas, 6 had no metastatic lesions on the chest X-rays before this therapy: three were alive without any evidence of disease for 18-25 months after high-dose MTX therapy. In some cases of other malignant solid tumors, particularly intracranial tumors, clinical efficacy was observed. Dose-time relationships, etc. should further be studied for more therapeutic efficacies of high-dose MTX therapy.

Adolescent↗
PubMed1981

Daily profile of baroreflex sensitivity and the variability of blood pressure in essential hypertensive patients.

1. We have monitored intra-arterial pressure continuously throughout the day and analysed every beat by computer. 2. Baroreflex sensitivity (ms/mmHg) was measured four times a day (07.00, 12.00, 17.00 and 20.00 hours) in seven patients and three times a day (07.00, 12.00 and 17.00 hours) in 23 patients. The diurnal variation of baroreflex sensitivity in individual patients was 0--5.3 ms/mmHg and was not consistent. Mean baroreflex sensitivity was reduced in hypertensive patients compared with normotensive subjects. 3. A negative correlation was seen between baroreflex sensitivity and the variability of systemic blood pressure. 4. Baroreflex sensitivity was well correlated with the variability of heart rate.

Adult↗
PubMed1981

Experimental myocarditis induced in mice by infection with influenza A2 virus.

A mouse model was established for the study of acute myocarditis that occurs during influenza infection. Challenge with more than 10 LD50 of mouse-adapted influenza A2 virus (H2N2) induced myocarditis macroscopically discernible as white, irregularly shaped lesions which were shown by histological examination to consist of necrotic myofibers surrounded by infiltrating mononuclear inflammatory cells. After challenge with 10 LD50 of the virus, macroscopic myocarditis was found to advance in a progressive manner up to the 7th day, while the virus titer in the heart reached its peak on the 2nd day and began to decrease on the 5th day of infection. However, development of myocarditis was significantly suppressed in mice which were irradiated with 400 R of X-rays before infection. In addition, myocarditis did not develop in congenitally athymic nude mice. These data indicate that myocarditis was not brought about by viral action directly, but that it was mediated by some function of the host against viral invasion, which was abolished by X-irradiation. The data also suggest that T cells played a key role in the development of myocarditis.

Animals↗