Search PubMed⌕ Search

Biomedical subjects

K Doi

Publications and source records attributed to K Doi.

At least 811 records · Page 45Linked to original sources
PubMed1979

Longitudinal study or serum thyroid hormones, chorionic gonadotrophin and thyrotrophin during and after normal pregnancy.

Measurements of serum levels of thyroxine (T4), free T4, 3,5,3'-triiodothyronine (T3), free T3, 3,3',5'-triiodothyronine (reverse T3, rT3), thyroxine-binding globulin capacity (TBGcap), chorionic gonadotrophin (hCG) and thyrotrophin (TSH) were carried out prospectively in eight women with uncomplicated pregnancies, in order to examine interrelationships between the thyroid gland and thyroid stimulating hormones during pregnancy. During pregnancy the levels of T4, free T4, T3, rT3 and TBGcap were significantly elevated, and TSH was decreased. It was noted that the elevation of T4 was maintained from the 8th to the 27th week of gestation while the level of TBGcap progressively increased. The levels of free T4 and rT3 in the first and third trimesters were significantly higher than those of age-matched, non-pregnant women. The levels of hCG showed a biphasic variation, with a peak in the 8th to 15th weeks, followed by a decline in the second trimester and a small, secondary elevation in the 32nd to 39th weeks. This later elevation was positively correlated with changes in free T4 and free T3 levels. The increase of serum T4 accompanied by an increase of free T4 in the first trimester appeared due to augmented secretion of T4, rather than being secondary to the elevated levels of TBGcap.

Adolescent↗
PubMed1979

Transient infantile hyperthyrotropinaemia. Report of a case.

A case of transient hyperthyrotropinaemia was found by mass screening for neonatal hypothyroidism using the paired TSH assay method. The patient was a baby boy born at term after a normal pregnancy who grew without any abnormal signs or symptoms. For the first 7 months after birth, his serum TSH was abnormally high while his total serum T4, T3, and free T4, T3 were within normal limits, exept for slightly low free T4 level at 7 months. The raised serum TSH decreased spontaneously to within normal limits after he was 9 months old.

Humans↗
PubMed1979

Identical biological effects of pancreatic glucagon and a purified moiety of canine gastric immunoreactive glucagon.

Because in the dog, the gastric fundus contains the largest amount of glucagon immunoreactivity (IRG), the IRG of mucosal scrapes of 105 canine stomachs was extracted by acid-ethanol and then precipitated by ether-ethanol. The IRG recovered was measured by antisera 30K, specific for glucagon and K-4023, which cross-reacts with glucagon-like immunoreactivity. Extracts of mucosa of stomach fundus were further purified by gel filtration on Bio-Gel P-30 in 3M acetic acid. One pooled fraction corresponding to marker pancreatic glucagon in its elution volume was then gel-filtered on Bio-Gel P-30 in 0.05 M NH(4)HCO(3) and yielded one IRG peak, which, however, showed three immunoreactive components on polyacrylamide disc gel electrophoresis in urea. In addition, antiserum K-4023 reacted more strongly with that peak than antiserum 30K indicating the presence of glucagon-like immunoreactivity in this fraction. Subsequent ion-exchange column chromatography on DEAE-Sephadex A-25 and then CM-Bio-Gel A allowed purification to a single protein band on disc gel electrophoresis reacting equally to both antisera 30K and K-4023. 1.5 mug of purified gastric glucagon was obtained and its biological effects were compared to those of pancreatic glucagon in isolated rat hepatocytes. When immuno-equivalent amounts (300-2,500 pg/ml) of either type of glucagon were used, the same biological responses with respect to glycogenolysis and gluconeogenesis as well as urea, lactate, and pyruvate production were observed. Liver cyclic AMP was also raised to the same extent by either one of these hormones. We conclude that this moiety of gastric IRG is apparently identical to pancreatic glucagon because (a) their molecular weights, elution properties in ion exchange chromatography, and their electrophoretic mobility are indistinguishable and (b) both hormones elicited identical biological effects in isolated rat hepatocytes.

Animals↗
PubMed1979

Histopathological study on effects of potassium aspartate on the hypothalamus of rats.

Rats of various ages were treated orally or intraperitoneally with potassium aspartate. The dose required to induce hypothalamic lesion varied considerably by the age of animals and route of administration. Additional experiment, in which the animals were orally treated three times a day with potassium aspartate in dose levels between the maximum safety dose and minimum lesion-producing dose in the preceding single dose study, revealed no hypothalamic lesion at all in any animals of each age group. In this condition, the maximum safety dose was 3--5 times as large as that in single dosage administration experiment. Regarding the safety evaluation of potassium aspartate preparations, brief discussions on some points in extrapolation of the results of the present experimental study to the clinical use were made.

Administration, Oral↗
PubMed1979

Lasting effect of infantile cold experience on cold tolerance in adult rats.

The effect of short and repetitive exposure to cold (5 degrees C, 4 hr/day for 2 weeks) from the birth up to the 14th day of newborn rats onthe thermal regulation in adulthood and on the tolerance to cold was investigated. After being exposed to cold, they were transferred to a room at 25 degrees C (N-CA). The control rats were raised at 25 degrees C (N-WA). An acute cold exposure test was performed by placing the animals in a room at 5 degrees C under urethane anesthesia. Electrical activity of neck muscles as an index of shivering was recorded. The colonic temperature fell at a significantly slower rate in N-CA rats with less shivering than in N-WA ones. Nonshivering thermogenesis tested by norepinephrine was significantly greater in N-CA rats than in N-WA ones. These results suggest that N-CA rats developed improved cold tolerance accompanied by greater nonshivering thermogenesis. Such a phenomenon in N-CA lasted for 18 weeks after the termination of cold exposure. Adult rats subjected to the same scheme of cold exposure (A-CA) (5 degrees C, 4 hr/day, 2 weeks) showed essentially the same results as seen in N-CA, but its improved cold tolerance and elevated nonshivering thermogenesis disappeared 4 weeks after the termination of cold exposure. Extirpation of interscapular brown adipose tissue immediately before the cold test did not appreciably affect the cold tolerance in N-CA and A-CA rats. The colonic temperature at the onset of shivering was significantly lower in N-CA as well as A-CA rats than in each of the corresponding control rats, indicating a shift of the shivering threshold to lower temperature values in the animals exposed intermittently to cold. These results indicate that an infantile experience with cold results in a greater and longer sustained ability to tolerate cold in adulthood, characterized by enhanced nonshivering thermogenesis.

Acclimatization↗
PubMed1979

Thermoregulatory nonshivering thermogenesis in men, with special reference to lipid metabolism.

The existence of thermoregulatory nonshivering thermogenesis, with special reference to lipid metabolism, was investigated in men. Acute cold exposure (10 degrees C, 60 min) produced a marked increase in heat production, with concomitant elevation of plasma free fatty acid (FFA) level, modest increase of ketone body concentration and lowered respiratory quotient (R.Q.). The correlation of heat production to plasma FFA levels was significantly positive; that is, subjects with higher heat production showed higher plasma FFA levels. Moreover, correlation of either heat production or plasma FFA levels to R.Q. was significantly negative, respectively. On the other hand, exposure to cold after an administration of nicotinic acid, which has a suppressive effect on FFA mobilization from adipose tissue, resulted in less cold-elevated heat production, a significant fall of plasma FFA and ketone body concentrations, and no change in R.Q. Although no visible or only slight shivering was observed in control cold exposure study, greater shivering occurred in the nicotinic acid cold exposure study. These results appear to indicate that nonshivering thermogenesis as a source of heat production achieved by enhanced utilization of lipids is also present in men.

Adult↗
PubMed1979

Seasonal variation of plasma glucagon concentrations in men.

In an attempt to understand a role of glucagon in seasonal acclimatization in men, measurements of plasma glucagon, blood free fatty acids (FFA), blood glucose, blood ketone body (beta-hydroxybutyrate) and hematocrit were made in 13 male and 8 female college staff members, aged 20 to 42, once a month for one year. Blood samples were obtained at 4:00 to 5:00 p.m, between meals. Average monthly temperatures during the study were as follows; Jan. -7.8, Feb. -5.6, March -3.7, Apr. 4.6, May 11.4, June 18.3, July 23.9, Aug. 22.0, Sept. 14.7, Oct. 7.5, Nov. 1.4, Dec. -4.2 (degrees C). Plasma glucagon, blood FFA and blood ketone body exhibited significant monthly variation in both sexes. Plasma glucagon as well as blood FFA level was significantly higher in winter (Dec., Jan., Feb.) than in summer (June, July, Aug), whereas blood ketone body level was lower in winter than in summer. Plasma glucagon level was significantly lower in female than in male subjects. A significant positive correlation was observed between plasma glucagon and blood FFA levels throughout the year. Seasonal variations of blood glucose and hematocrit were not observed. These results suggest that seasonal variation in glucagon secretion is associated with seasonal changes in ambient temperatures as one of the strategies for climatic acclimatization through regulation of lipid metabolism.

Acclimatization↗
PubMed1979

Homotransplantation of limbs in rats. A preliminary report on an experimental study with nonspecific immunosuppressive drugs.

We did 97 limb homografts among histoincompatible rats, Wistar and Fischer 344 pairs, and we concluded as follows. 1. Using microvascular anastomoses, rats are technically, immunologically, and economically superior to other animals for the study of limb homografts. 2. The homografted legs in animals without the use of any immunosuppressive agents were rejected by the 14th postoperative day (average, 12.5 days) among the Wistar and Fischer 344 pairs. The common features of limb rejection became clear, both macroscopically and histologically. 3. Rats immunosuppressed with azathioprine and prednisolone retained the homografted legs intact for 24, 21, and 17 days (when the recipient rat died). Other immunosuppressive drugs (6-MP, prednisolone) did not delay rejection.

Animals↗
PubMed1978

Application of radiographic magnification technique with an ultra-high-speed rare-earth screen/film system to oral cholecystography.

2X magnification employing a 200-mu focal spot and an Alpha 8-XM screen/film system was applied to oral cholecystography and the results compared with those for the conventional contact technique with the Par-RP system. The basic imaging properties of the system, as well as phantom studies, indicated that the image quality obtained with magnification is comparable to or better than that for the conventional technique. In clinical studies on the detection of gallstones, the conventional technique revealed 5 true-positive and 17 true-negative cases and 1 false-positive and 2 false-negative cases, while the magnification technique provided 7 true-positive and 18 true-negative cases but no false cases. With the magnification technique the skin dose was reduced to approximately half that for the conventional contact technique.

Cholecystography↗
PubMed1978

Biochemical studies on rats with insulin-secreting islet cell tumors induced by streptozotocin: with special reference to physiological response to oral glucose load in the course of and after tumor induction.

Pancreatic islet cell tumors were induced in 32 of 49 male Wistar rats (73%) surviving 9 months or longer following treatment with streptozotocin alone, with streptozotocin and nicotinamide, or with streptozotocin and picolinamide. Serial oral glucose tolerance tests in rats treated with streptozotocin and nicotinamide showed that the elevation of blood glucose levels after oral glucose load was depressed significantly 7 months after treatment. Plasma insulin responses were distinctly elevated 9 months after treatment. Blood glucose levels remained lower and plasma insulin levels rose markedly after a glucose load in tumor-bearing rats as compared to the response of tumor-free rats. These findings suggest that pancreatic islet cell tumors induced by streptozotocin with and without combined treatment are insulin-secreting, and that streptozotocin itself has oncogenic effects on the rat pancreas. Mean insulin concentration in islet cell tumors amounted to 401 U/g wet wt, whereas the concentration was 14 U/g wet wt in the pancreatic tissue from tumor-free rats.

Adenoma, Islet Cell↗