Biomedical subjects
Publications and source records attributed to T Obara.
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The in vitro treatment with Fusarenon-X, a mycotoxin produced by Fusarium nivale Fn 2B, depressed the mitogenic responses of mouse lymphocytes to the T-cell mitogens, phytohaemagglutinin (PHA) and concanavalin A (Con A), but to a lesser extent to B-cell mitogen, a bacterial lypopolysaccharide (LPS). The in vitro treatment of mice with Fusarenon-X also decreased the responsiveness of splenic lymphocytes to the T-cell mitogen, Con A. Administration of Fusarenon-X to BALB/c mice before immunization significantly reduced anti-DNP IgE and IgG1 responses, while the treatment of mice after immunization was less effective. The number of spleen cells of the treated mice was increased with a reduction of T lymphocytes and an increase of granulocytic elements. In vitro antibody responses of spleen cells from Fusarenon-X treated mice by pokeweed mitogen (PWM) or LPS were also suppressed. Reconstruction experiments using sIg positive and negative spleen cells from normal and Fusarenon-X treated mice showed that this inhibitory effect resided in the sIg negative cell population.
The effect of a water-soluble fraction (CEF) that was prepared from an extract of Corynebacterium equi on primary reaginic antibody formation was studied in Balb/c mice. Mice were immunized with a hapten carrier (DNP-OVA) and received intraperitoneal injections of CEF 7 and 2 days prior to, or 2 and 7 days after the immunization. PCA titers of both antihapten (DNP) and anticarrier (OVA) antibodies of IgE class were reduced significantly by the CEF treatment. Evidence was presented in adoptive transfer experiments that the number of IgE-producing cells in the CEF-treated mice was lower than that of controls. Suppression of IgG1 anti-DNP antibody formation was also achieved by the CEF treatment. Formation of IgG1 anti-OVA antibodies, however, was not suppressed significantly by the treatment. The suppressive activities of CEF were shown to be dose-dependent, but timing of CEF administration did not appear critical.
The relation of the rate of circulating air change to room temperature and relative humidity in animal quarters with a central air-conditioning system during heating and cooling seasons was investigated, with the results as follows: During the period of heating, the ambient temperature generally rose with a fall of relative humidity as the number of conditioned air changes per hour was increased. Vertical differences in temperature and humidity between levels of 0.5 and 1.5 m above the floor also diminished with increasing air change rate. This tendency was more conspicuous in small animals rooms with outer walls facing north and west. With increasing rate of air changes, the room temperature was prone to decline and the relative humidity to rise during the period of cooling. There were less vertical differences in temperature and humidity during this period. The velocity of air circulation within the animal quarters and its variations tended to increase progressively with increasing rate of ventilation, though the changes were modest.
A water-soluble fraction (CEF) obtained from Corynebacterium equi was administered intradermally or intravenously into Sprague-Dawley rats. Passive cutaneous anaphylaxis (PCA) was elicited in these rats along with the controls by sensitization with mouse anti-DNP serum and challenge with the corresponding antigen. PCA reactions were markedly inhibited by the pretreatments of the rats with CEF. Similar treatments of the animals 2-4h after the sensitization did not inhibit PCA. Inhibitory activity of CEF in the pretreated animals was shown to be dose-dependent. Incubation of rat peritoneal mast cells with CEF effectively blocked the binding of murine IgE antibodies to the cells as evidenced by the failure of the treated cells to bind the antibodies. Furthermore, antigen-induced histamine release from rat mast cells, which were sensitized with murine IgE antibodies, was reduced significantly by CEF treatment of the cells prior to the sensitization. Results of this study indicated that CEF inhibits the PCA in rats, presumably by blocking the binding of heterocytotropic antibodies to Fc receptor of mast cells.
Two generations of rats were raised at animal room temperature ranging from 12 to 32 degrees C at steps of 2 degrees C. The body weight of rats born in 22 degrees C environment and exposed to each temperature did not significantly differ within the range of 16-28 degrees C. The delivery rate, litter size, and weaning rate decreased at 30 degrees C and 32 degrees C, and only the weaning rate had a tendency to decrease at 12 degrees C. No significant difference was demonstrated within the 14-28 degrees C range for any reproduction parameter observed. The body weight of sucklings did not differ at birth within the 12-32 degrees C range; and at 3 weeks of age, there were no differences within the range of 18-28 degrees C. The body weight gain in both sexes after weaning was generally small when the temperature was below 18 degrees C or above 30 degrees C. There were no significant differences in food intake within the 20-26 degrees C range, in water intake within the 12-26 degrees C range, in hematological and serum biochemical values within the 20-26 degrees C range, and in organ weights within the 18-28 degrees C range. Therefore, the range of 20-26 degrees C (68-78 degrees F) was the optimum temperature range in rat rooms.
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Carcinoembryonic antigen (CEA) activity was confirmed in the C-cell of the normal thyroid by immunohistochemical techniques. This suggests that CEA production in medullary carcinoma of the thyroid is not initiated by carcinogenesis, but reflects a function of the normal C-cell. It is not yet clear whether CEA production in the C-cell may be influenced by carcinogenesis. The C-cell is the first APUD cell that was confirmed to have CEA activity.
Normal rabbit serum contains an IgG-like component(s) that binds spermine as well as other polyamines. This molecule(s) has the same physicochemical properties as anti-spermine antibody obtained from rabbits immunized with spermine-thyroglobulin conjugates. However, the polyamines-binding IgG-like molecule(s), unlike anti-spermine antibody, is incapable either of precipitating a spermine-bovine serum albumin complex or of binding to a spermine-Sepharose column. These results suggest the existence of a naturally occurring anti-polyamine antibody that may have defective antibody functions.
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Twelve cases of patients with primary aldosteronism (PA) who admitted to Hokkaido University Hospital from 1965 to 1975 were studied. 1. Attention should be paid for the existence of PA as a frequent cause of juvenile hypertension in female, since female were frequently than in male (11 cases of female to 1 case of male) and 10 of 12 patients with PA were pointed out to have high blood pressure at the age of under 40. 2. Periodic paralysis as a main clinical symptom with PA were more frequent in our study than in the reports of other countries, which might be due to a large amount of salt intake in Japanese. 3. In accordance with the rapid progress of hormonal estimation for plasma renin activity (PRA) and plasma aldosterone concentration (PAC), the usefulness of potassium clearance test by the use of sodium thiosulfate became less worth. 4. It was impossible to differentiate primary aldosteronism from low renin essential hypertension by means of PRA after the stimuli of intravenous injection of furosemide and walking, but it could be differentiated after 3 days of sodium restriction, 3 days of administration of hydrochrolothiazide (75 mg/day) and 3 hours of walking. 5. With the long-term use of diuretics and various kinds of antihypertensive drugs in the treatment of high blood pressure in patients with PA, normal basal level and responsiveness of PRA were observed. Therefore no patient should be put through renin and aldosterone studies while on diuretics and antihypertensive drugs. 6. The 131I-19-iodocholesterol adrenal scintigraphy is a first choice method for the localizing diagnosis of PA because of inherent disadvantages in selective adrenal venography or in the determination of PAC in adrenal venous blood obtained against by catheterization of the adrenal veins.
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Serum carcinoembryonic antigen (CEA) and calcitonin were assayed in 8 patients with medullary carcinoma of the thyroid (MCT) and 14 unaffected family members, from 4 pedigrees of Sipple's syndrome and one pedigree with inherited MCT. Serum CEA ranged from 5.4 to 44.5 ng/ml in the patients, but less than 2.5 ng/ml in the unaffected. This is in contrast with retinoblastoma and cancer family syndrome, where not only the patients but also unaffected family members show high serum CEA, and cytoplasmic or selective maternal inheritance of serum CEA level is presumed. In inheritable MCT, serum CEA increases in association with the development of MCT, and serum CEA level per se is not inherited.
There are many complications due to hemodialysis, causes of which seem to lie under disorders of the coagulation system, fibrinolytic system, and kinin system. Therefore, it is important to understand the dynamics of these systems during hemodialysis. Accordingly, kallikreinogen, plasminogen, plasmin inhibitors, contact factor, antithrombin, and prothrombin were assayed during the experimental dialysis, experimental ultrafiltration and clinical hemodialysis. Plasmin inhibitors decreased remarkably by dialysis. They then recovered the pre-dialytic values as time went on. Kallikreinogen did not show any definite tendency immediately after the beginning of dialysis, but two hours later its value rather increased relative to thepre-dialytic value. It was supposed that this increase was caused by reactive hyperproduction due to gradual consumption of kallikreinogen. Contact factor slightly decreased by dialysis, whereas prothrombin and antithrombin decreased apparently. When hemodialysis is practiced, it is necessary to fully realize that the coagulation system, fibrinolytic system, and kinin system might lose their balance.
The number of air-borne bacteria in air ducts and barrierred laboratory animal rooms with the so-called econovent rotary heat exchanger, were checked monthly during a year by the pin-hole sumpler method for air ducts and Koch method for animal rooms. Also, concentration of ammonia was checked with the same samples by gas impinger. No significantly difference in number of air-borne bacteria was seen between before and after passing the econovent. Those passing through HEPA filter was not detected. There were more air-borne bacteria in animal rooms, outside locker room and shower room than in the corridor, utensil storage, inside locker room and pass box. No ammonia were detected in the outdoor, but exhaust air duct after passing the econovent contained very small amount of ammonia. On the other hand, high concentration of ammonia were preserved in the supplying air duct, exhaust air duct and mice and rats rooms, about 86% of ammonia in exhaust air duct returned back into the supplying air duct. No influences on reproduction in mice and rats were recognized.
UNLABELLED: There have been many biomechanical studies throughout the world on the fracture treatment. However, only a few were performed under intravital condition. The purpose of the present study is to measure the successive strength changes of the callus after a fracture, in vivo in an animal. METHOD: Specifically designed Küntscher nails were made to meet the anterior convexity and the size of the medullary canal of the femora of goats. Three self-temperature-compensating semi-conductor strain-gauges were glued on the inner surface of the nail and coated with epoxy-resin and silicone rubber. The nail was inserted into the intact femur, and the initial measurement of the strains was performed using a specially designed wooden three point bending jig. Then the femur was transected at the middle. Periodical measurements of the strains were done, first, during walking and, then, with the three point bending jig under general anesthesia. Ten goats were used for the experiments. The measurement was undertaken every two to three weeks. Serial x-rays were taken. The femur was studied histopathologically after the death of the animal. RESULTS: 1. Although the nail with the strain-gauges presented some foreign body reaction and certain difficulties in sterilization, it was well tolerated by the animal, permitting the strain measurement for as long as 18 weeks after the fracture. 2. There was a tendency that the less loosening is found between the nail and the bone, the larger is the strain and the smaller becomes the dispersion of the strains. 3. On the three point bending test, the post-fracture strain changes were not directly proportional to the lapse of time. In the early phase, the strains remained large for about four weeks and tended to rapidly decrease in the middle and late phases in accordance with the development of callus formation on x-ray. 4. A similar strain change was observed on the walking test, although the animal presented with some painful limp. The results suggest that early excessive exercise to be avoided when an intramedullary fixation is not sufficiently rigid.