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Biomedical subjects

A Hidaka

Publications and source records attributed to A Hidaka.

At least 73 records · Page 4Linked to original sources
PubMed1990

Hepatic neoplasms: effects of transcatheter arterial embolization on coagulation and fibrinolysis.

Forty-eight patients with hepatic malignancy (47 with hepatocellular carcinoma, one with metastatic colon carcinoma), who underwent transcatheter arterial embolization (TAE) for treatment of hepatic neoplasms, were investigated to determine the effects of TAE on coagulation and fibrinolysis. TAE was followed by a significant decrease in the platelet count (P less than .001); a prolongation of prothrombin time (P less than .001); an early increase in levels of fibrinopeptide A (P less than .01), fibrinopeptide B beta-15-42 (P less than .001), and fibrin(ogen) degradation products (P less than .001); and a delayed increase in the fibrinogen level (P less than .001), without a significant prolongation of the activated partial thromboplastin time. In the three patients who developed disseminated intravascular coagulation (DIC) after TAE, a reduction of both the platelet count and fibrinogen level occurred significantly earlier and in a more severe form than in the other patients without DIC; this reduction preceded the onset of the characteristic symptoms of DIC. Data suggested that close monitoring of platelet count and fibrinogen level is important for early detection of DIC following TAE.

Adult↗
PubMed1990

Endotoxemia in patients on hemodialysis.

We examined endotoxins and limulus amebocyte lysate-reactive material (LAL-RM) in serum from 87 patients on hemodialysis, using the conventional chromogenic limulus test (CCLT) and a new specific endotoxin assay with factor G-free LAL (endotoxin-specific test: EST). All patients with regenerated cellulose dialyzers had increased CCLT values, whereas the EST values were not higher than in controls. This discrepancy can be explained by the LAL-RM which is cellulose-derived and cross-reacts with LAL via factor G. Using EST for measurements of endotoxin, 6 patients out of 87 had pathological endotoxemia and all of these patients were associated with either cirrhosis, infection, or malignancy. Some patients who had no complications showed fever before or during dialysis, but they did not have high endotoxin levels. EST is useful for the diagnosis of endotoxemia in patients on hemodialysis because of the presence of LAL-RM in serum. Endotoxemia is rare in patients on hemodialysis, if they are not associated with infection, cirrhosis, or other complications.

Adult↗
PubMed1990

Thyroid response, especially to thyrotropin-binding inhibitory immunoglobulins, in euthyroid relatives of patients with Graves' disease: a clinical follow-up.

Three hundred and fifty-three euthyroid relatives of Graves' disease patients were tested for TSH binding inhibitory immunoglobulins (TBII). Eighteen had elevated levels of TBII, and 232 who had negative TBII levels also agreed to be followed for a period of 6-30 months. TBII was chosen as the critical screening measurement for this study, rather than thyroid-stimulating antibodies (TSAb) and thyroid-stimulating blocking antibodies (TSBAb), because of the availability and ease of use of TBII RIA kits. Eleven of the 18 subjects with elevated TBII were T3 nonsuppressible (group I), and 10 of the 11 were TRH unresponsive. Nine of these 10 subjects showed TSH levels below 0.05 mU/L. The remaining 7 subjects were T3 suppressible and TRH responsive (group II). Alterations in thyroid status occurred in 8 of the 11 subjects in group I during follow-up. One developed hypothyroidism, and 7 became hyperthyroid. The hypothyroid subject had initial titers of TBII, TSAb, and TSBAb that were markedly elevated, and TSAb disappeared when she became hypothyroid. Six of the 7 subjects who developed hyperthyroidism had elevated TSAb and negative TSBAb titers while they were euthyroid. All 7 subjects in group II remained euthyroid during the follow-up period. Only 2 of the 232 relatives who initially had negative TBII titers became hyperthyroid during the follow-up period. The results indicate that euthyroid relatives with a family history of Graves' disease who have elevated TBII levels and suppressed basal serum TSH concentrations have a much higher potential to develop hyperthyroidism than those who have normal or negative TBII levels.

Adolescent↗
PubMed1990

Simultaneous measurement of TSH-binding inhibitor immunoglobulin and thyroid stimulating autoantibody activities using cultured FRTL-5 cells in patients with untreated Graves' disease.

A new and practical assay was developed using cultured FRTL-5 cells for simultaneous assessment of TS-ab and TSH-binding inhibitor immunoglobulin, allowing direct comparison of these two activities under the same conditions. Subsequent to the TS-ab assay in which extracellular cAMP concentration in Hanks' medium without NaCl was determined, [125I]b TSH in this medium was added to observe the ability of serum Ig to inhibit the binding of [125I]b TSH to FRTL-5 cells. We found a much higher specific binding of [125I]b TSH to FRTL-5 cells and a much greater inhibition of [125I]bTSH binding to the cells exposed to Graves' Ig in hypotonic NaCl-free than in NaCl containing Hanks' medium, indicating that the binding of both TSH and Graves' Ig to the TSH receptor was salt-sensitive. The inhibitory activity of [125I]bTSH binding to the cells was 0.2 +/- 4.6% (mean +/- SD) in 45 normals. Inter-assay coefficients of variation in two positive controls with the mean values of 18.0 and 65.8% were 15.8 and 16.5%, respectively. Among 46 patients with untreated hyperthyroidism owing to Graves' disease, 45 (97.8%) were positive for TS-ab; 35 (76.1%) and 40 (87.0%) were positive for TSH-binding inhibitor in Ig assays using FRTL-5 cells and solubilized porcine thyroid membranes, respectively. TS-ab activities correlated less closely with TSH-binding inhibitory activities determined using FRTL-5 cells (r = 0.576, p less than 0.001) than with those determined using porcine thyroid membranes (r = 0.745, p less than 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

Autoantibodies↗
PubMed1990

Uterine resting tonus and maternal hypertension during late pregnancy--existence of intrauterine capacity.

The uterine resting tonus was measured with an open-end catheter beginning from the 24th gestational week through the onset of labor in order to investigate changes in the intrauterine environment from the physical aspect. The measurements were performed in 183 primiparas for a total of 272 times and 102 multiparas for a total of 120 times. The uterine resting tonus was almost constant from the 2nd trimester through the 3rd trimester, but it tended to increase gradually beginning 2-3 weeks prior to the onset of delivery. This tendency was more pronounced in primiparas, and their mean tonus was about 5mmHg higher than that of multiparas throughout the pregnancy. In 55 subjects in whom both the resting tonus and blood pressure were simultaneously measured at least twice during pregnancy, the mean maternal blood pressure increased as the resting tonus increased. The above findings revealed a positive correlation between the resting tonus and the maternal blood pressure and suggested the presence of a critical point in terms of the intrauterine capacity, which derives from the properties of the uterine muscle and the intrauterine contents, consisting mainly of the fetus. The increase in the resting tonus is surmised to be related to this critical point.

Adult↗
PubMed1989

Stimulation of cyclic AMP production in FRTL-5 thyroid cells by crude immunoglobulin fractions of serum from pregnant women.

In an assay for thyroid-stimulating antibodies, in which FRTL-5 thyroid cells were incubated with crude immunoglobulin (Ig) fractions precipitated from serum with 15% polyethylene glycol, significant increase in cAMP production was elicited by the samples from 25 (35.7%) out of 70 pregnant women. The highest value was 529.5%. There was a close correlation between thyroid stimulating activities and serum hCG concentrations (r = 0.708, P less than 0.001). When 125I-hCG was added to serum from pregnant women, about 20% of the radioactivity was incorporated into the Ig fractions. hCG preparations within a range of concentrations of 30-300 IU/m elicited 2.3-16.5 times increase in cAMP in a dose-dependent manner. Nine pregnant women with serum TSH concentrations less than the lower limit of the normal range (less than 0.25 mU/l) displayed significantly higher values for both thyroid stimulating activities and serum hCG concentrations (P less than 0.001, respectively) compared with those who had normal TSH levels in serum. These data suggest that hCG or its variant may stimulate the thyroid sufficiently to suppress secretion of TSH from the pituitary in some pregnant women.

Adult↗
PubMed1989

Role of thyrotropin receptor antibodies in the development of hyperthyroidism: follow-up studies on nine patients with Graves' disease.

TSH binding inhibitor immunoglobulin (TBII) and thyroid-stimulating antibody (TSAb) activities were measured serially for 4-32 months in nine patients before and during development of hyperthyroidism due to Graves' disease. Initially, all were euthyroid, seven had thyroid enlargement, one had proptosis, and seven had high serum titers of antithyroid microsomal antibodies. The occurrence of hyperthyroidism was preceded by detection of both TBII and TSAb in four patients and detection of TSAb alone in four patients. One patient had neither TBII nor TSAb when euthyroid. The mean initial TBII and TSAb activities were 10.2 +/- 15.2% (+/- SD) and 2677 +/- 4620%, respectively, when these patients were euthyroid. When they became hyperthyroid, both TBII and TSAb activities increased in all patients. At that time, TBII was detected in all but one (eight of nine subjects; 88.9%), with a mean activity of 58.8 +/- 23.4% (+/- SD), and TSAb was detected in all nine patients, with a mean value of 4508 +/- 4429%. These findings not only indicate the crucial role of TSH receptor antibodies in the development of hyperthyroidism due to Graves' disease, but also suggest that a certain period of subclinical Graves' disease exists before the onset of overt hyperthyroidism in most patients, in the sense that they have TSH receptor antibodies, especially TSAb, in their serum even though they are euthyroid.

Adult↗
PubMed1989

Mechanisms of increased sensitivity for detection of thyroid stimulating antibodies by use of hypotonic medium.

We have attempted to clarify the mechanism whereby the sensitivity to detect thyroid stimulating antibodies by use of cultured thyroid cells is enhanced when sodium chloride is removed from isotonic medium. Preexposure of cultured porcine thyroid cells to 10(-4) mol/l cycloheximide increased the subsequent cAMP response to TSab stimulation in isotonic NaCl medium, but not in hypotonic NaCl-free medium. Crude membrane fractions from porcine thyroid tissues were incubated with 6 Graves' IgGs in NaCl or NaCl-free medium at 37 degrees C for 1 h, centrifuged, washed, added [125I]TSH, and incubated for another hour. The result of the 'residual TBII assay' indicated that all 6 IgGs exhibited greater inhibition of [125I]TSH binding to the membranes when pre-incubated under hypotonic than isotonic conditions. When cultured porcine thyroid cells were incubated with 7 TSab samples in NaCl or NaCl-free medium depleted with 3-isobutyl-1-methylxanthine at 37 degrees C for 1 h, washed, added the NaCl-free medium containing 3-isobutyl-1-methylxanthine, and incubated for another 2 h, the use of NaCl-free medium during the pre-incubation resulted in greater increase in cAMP elicited by all 7 samples. In summary, 1) an inhibitory mechanism upon adenylate cyclase seems to be involved under isotonic conditions and may require new protein synthesis; 2) the binding of TSH receptor antibodies to the TSH receptor increases when NaCl is removed from isotonic medium, and 3) these factors are considered responsible for the enhanced sensitivity under hypotonic conditions.

Animals↗
PubMed1989

[The influence of increased uterine resting tonus on renal sympathetic nerve activity in pregnant rabbit].

We have shown that an increase in uterine resting tonus causes an increase in maternal blood pressure and a decrease in renal blood flow, and a neural factor may control this phenomenon through a Utero-Renal Reflex in pregnant rabbits. To explore this possible neural factor, we examined the changes in renal sympathetic nerve activity (R-SNA) in late pregnant rabbits under urethane anesthesia. SNA was measured with a bipolar electrode and renal cortical blood flow (RBF) was measured by a thermocouple method. An increase in uterine resting tonus was made by inserting a small balloon into the uterine cavity on the ovarian or cervical side. An increase in resting tonus on the ovarian side caused an increase in maternal blood pressure, increases in R-SNA and renal vascular resistance (RVR), and a decrease in RBF. However, an increase in resting tonus on the cervical side resulted in an increase in maternal blood pressure, slight increases in R-SNA and RVR, and an increase in RBF. These data indicate that an increase in uterine resting tonus can stimulate R-SNA, which in turn causes the deterioration of renal circulation.

Animals↗
PubMed1989

[Studies on renal sympathetic nerve activity related to the existence of a utero-renal reflex in pregnant rabbit].

We have shown that the changes in renal blood flow (RBF) and renal sympathetic nerve activity (R-SNA) in metreurysis are different on the ovarian side from those on the cervical side. We examined their dissimilar mechanisms, and the changes in noradrenaline in the renal vein under metreurysis as an indicator of SNA and we also explored the pathway of Utero-Renal Reflex. In pregnant rabbits, SNA was measured by using bipolar electrode and renal cortical blood flow was measured by the thermocouple method. Noradrenaline was measured by HPLC. A small balloon was inserted into the uterine cavity on the ovarian or cervical side to increase the uterine resting tonus (URT). Noradrenaline increased under metreurysis with the increase in R-SNA. After protecting the abdominal large vessels an increase in URT in the cervical side caused the elevation of mean blood pressure, an increase in R-SNA and a decrease in RBF. After blocking the nerve around the suspensory ligaments an increase in URT in ovarian side did not cause an increase in R-SNA or a decrease in RBF. These data indicate that an increase in URT can stimulate R-SNA through the Utero-Renal Reflex, which in turn causes the deterioration of renal circulation.

Animals↗
PubMed1988

Sensitive, practical bioassay of thyrotropin, with use of FRTL-5 thyroid cells and magnetizable solid-phase-bound antibodies.

We have developed a new method for assessing the bioactivity of thyrotropin (TSH) in human serum by measuring cAMP production in FRTL-5 thyroid cells as an index of stimulation. To eliminate serum inhibitors of the cAMP response to TSH, we purified samples by mixing them with anti-TSH antibodies coupled to magnetizable particles. This method of immunoaffinity purification was simple and suitable for the measurement of a large number of samples. The detection limit of the bioassay was 3.13 milli-int. units of human TSH per liter. Intra-assay and interassay coefficients of variation ranged from 5.4 to 8.6% and from 12.6 to 21.5%, respectively. The concentrations of bioassayable TSH closely correlated with those of immunoassayable TSH, both in the immunoaffinity-purified samples (r = 0.946, P less than 0.001) and in the serum samples (r = 0.945, P less than 0.001) from 14 euthyroid subjects and 53 hypothyroid patients with Hashimoto's thyroiditis. The bioactivity-to-immunoactivity ratio was almost constant (0.84 +/- 0.30; mean +/- SD) over the range of concentrations of immunoassayable TSH in serum, 6.3 to 177 milli-int. units/L. We also demonstrate that the technique is applicable to measurements of bioactivities of circulating forms of immunoreactive TSH in different pathophysiological conditions.

Animals↗
PubMed1988

[Clinical and experimental studies on the pathogenesis in pregnancy induced hypertension].

Placental ischemia is one of the etiological factors of pregnancy induced hypertension (PIH), however, the pathogenesis of placental and renal ischemia has not been clarified. The purposes of this investigation are (1) to clarify the fetomaternal hemodynamic changes in PIH and the influence of maternal postural change on fetomaternal hemodynamics, measured by thermodilution method, impedance cardiography and pulsed doppler method during pregnancy, (2) to provide to relationship between intrauterine resting tonus and maternal hemodynamics, that is, blood pressure, placental and renal blood flow measured by electromagnetic flowmeter and thermocouple method, and renal nerve activity, and (3) to study the influence of placental ischemia on vascular sensitivity to angiotensin II measured by Magnus method in animal experiment. (1) The increase in C.O and blood volume were recognized from the beginning of pregnancy to 24 GW, and subsequently, the decreasing tendency were found from about 32 GW to the onset of labor. However this decreasing tendency were subsided in the lateral position. These circulatory changes were observed in both normotensive and PIH cases, and especially, the decrease in C.O and blood volume in late pregnancy were more remarkable in PIH than that in normotensive pregnancy. From the results of Starling curve, left ventricular work was more hyperdynamic status in PIH than that in normotensive pregnancy, these results show that there are a compensatory mechanism against high vascular resistance in PIH. A/B (S/D) ratio in uterine artery, umbilical artery and fetal aorta were lowered in II-nd and III-rd trimester and more decreased in the lateral position from the supine position, on the other hand these ratio in PIH were elevated respectively. These results show that there are the aortocaval compression by the heavy tensive uterus and subsequent sluice flow mechanism in fetoplacental circulation in the supine position in late pregnancy. (2) These vascular compression were recognized very often in PIH accompanying with increasing in uterine resting tonus. It was recognized in pregnant rabbit that an increase in uterine resting tonus in the ovarian side caused an increasing blood pressure, a decrease in renal and placental blood flow and an increase in renal sympathetic nerve activity (RSNA). After resection of the suspensory ligament of ovarii, an increase in resting tonus in the ovarian side did not only cause an increase in RSNA, but also a decrease in renal blood flow.(ABSTRACT TRUNCATED AT 400 WORDS)

Angiotensin II↗