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Biomedical subjects

A Sato

Publications and source records attributed to A Sato.

At least 523 records · Page 29Linked to original sources
PubMed1995

Effect of thyrotropin-releasing hormone on serum thyroid hormones: a study in the patients with untreated and treated Graves' disease and subacute thyroiditis.

In order to investigate the extrapituitary action of TRH on the thyroid, serum T3, T4, and TSH levels after im administration of TRH were analyzed in 63 patients with untreated hyperthyroid Graves' disease, in 60 euthyroid patients with treated Graves' disease, in 8 patients with subacute thyroiditis, and in 140 healthy subjects. TRH administration in the healthy subjects resulted in a significant increase in serum T3 and T4 levels after 2 h. However, in the patients with untreated hyperthyroid Graves' disease, a significant decrease in serum T3 and T4 levels with undetectable TSH was found 2 h after TRH administration. In the patients with subacute thyroiditis, serum T3 levels also significantly decreased after TRH administration. When a decrease in serum T3 and T4 levels after TRH administration in the patients with hyperthyroid Graves' disease was analyzed in terms of thyroid microsomal antibody and thyroglobulin antibody, a decrease in serum T3 and T4 levels was largest in patients with thyroid microsomal antibody and thyroglobulin antibody. In contrast, an increase in serum T3 and T4 levels in response to TRH in the euthyroid patients with Graves' disease was largest in patients without thyroid autoantibodies. It is concluded that TRH acts directly on the thyroid to suppress the thyroid hormone secreting activity in the absence of circulating TSH and that thyroid autoantibodies affect thyroidal response after TRH administration.

Adolescent↗
PubMed1995

Expanding intracerebral hematoma from pituitary adenoma: case report.

We report the case of a 53-year-old man presenting with a headache of sudden onset and blurred vision secondary to hemorrhage from a nonfunctioning pituitary adenoma, which had been treated 25 years previously by transcranial surgery and postoperative irradiation. The intratumoral and intracerebral hematoma expanded to three times its initial size because of a recurrent hemorrhage that occurred during a 2-day period while the patient awaited surgery. The mechanisms of hematoma expansion and the management strategy in such a case are discussed, and a review of the pertinent literature is presented.

Adenoma, Chromophobe↗
PubMed1995

Diagnostic and prognostic value of myocardial scintigraphy with thallium-201 and gallium-67 in cardiac sarcoidosis.

STUDY OBJECTIVE: To examine the diagnostic and prognostic value of myocardial scintigraphy using thallium-201 and gallium-67 in cardiac sarcoidosis. PATIENTS: Twenty-five patients with sarcoidosis. METHODS: All patients underwent myocardial thallium-201 scintigraphy. Six patients with myocardial thallium-201 defects were classified into group A and another 19 without defects were classified into group B. Between group A and B, we compared the results of other noninvasive examinations, including standard 12-lead ECG, 24 h ambulatory ECG, chest radiography, measurements of serum angiotensin-converting enzyme (ACE) and lysozyme levels, and gallium-67 scintigraphy. RESULTS: Proportions of subjects who had varying degrees of heart block, severe ventricular arrhythmias (more than or equal to third grade of Lown's classification), and high levels of serum ACE and lysozyme levels were not different between these two groups (p > 0.05). Although an enlarged cardiothoracic ratio was more frequent in group A (p < 0.05), bilateral hilar lymphadenopathy was more frequent in group B (p < 0.01). Four patients of group A and 15 of group B underwent gallium-67 scintigraphy. Although no subjects of group B had myocardial uptake of gallium-67, two of four group A patients showed cardiac uptake. These four group A patients were treated with corticosteroids. The therapy provided clinical and scintigraphic improvement in two patients with myocardial gallium-67 uptake, although it did no improvement in the other two patients without gallium-67 uptake. CONCLUSIONS: When cardiac sarcoidosis was diagnosed according to myocardial thallium-201 defects, other noninvasive examinations were not useful to detect this disease. However, gallium-67 uptake may predict the efficacy of corticosteroids. Thus, the combination of thallium-201 and gallium-67 scintigraphy may be useful not only in diagnosis of cardiac sarcoidosis but also in prediction of effects of corticosteroids.

Adrenal Cortex Hormones↗
PubMed1995

Hypersensitivity pneumonitis associated with home ultrasonic humidifiers.

We describe five patients with hypersensitivity pneumonitis (HP) that was related to using home ultrasonic humidifiers. All patients had micronodular infiltrates on their chest radiograph, and their lung biopsy specimens revealed alveolitis with or without epithelioid cell granulomas. Challenge tests were performed on two patients with the humidifier water and three patients using the humidifier. All patients tested exhibited a positive response. Tests for precipitating antibodies against an extract of the humidifier water gave strongly positive reactions in all patients tested. Precipitins to Cephalosporium acremonium and Candida albicans were also present in all cases, whereas precipitins to thermophilic actinomycetes were not detected. Although cultures of the water grew a variety of fungal and bacterial organisms, thermophilic actinomycetes could not be detected. These findings suggest that thermophilic organisms may not be the causative antigens of HP associated with ultrasonic humidifiers. All five patients had an increase in the bronchoalveolar lavage (BAL) lymphocytes that were predominantly CD4+ lymphocytes. The T helper cell count (CD4) to suppressor T cell count (CD8) ratio was significantly higher than that observed in summer-type HP, and lower than that observed in bird fancier's lung, indicating that the phenotypes of the BAL lymphocytes may vary with the type of HP.

Adolescent↗
PubMed1995

Modulation of angiotensin II type 1 receptor mRNA expression in human blood cells: comparison of platelets and mononuclear leucocytes.

The objective of the present study was to quantify the expression of angiotensin II type 1 (AT1) receptor transcripts in human blood cells--platelets and mononuclear leukocytes--from 10 normal healthy volunteers during the alterations in the renin-angiotensin system. A quantitative assay employing reverse transcription-polymerase chain reaction (RT-PCR) was utilized. Oral administration of furosemide, 40 mg for 2 days, under mild salt restriction (50 mEq NaCl/day) for 6 days stimulated the renin-angiotensin system resulting in significant increases in plasma renin activity (PRA) (1.84 +/- 0.12 vs. 1.05 +/- 0.17 ng/l/s; P < 0.01), plasma angiotensin II concentration, and plasma aldosterone concentration (PAC). The ratio of AT1 receptor mRNA to glyceraldehyde-3-phosphate dehydrogenase (GAPDH) mRNA expression in mononuclear leucocytes was significantly (P < 0.05) increased from the basal level (0.49 +/- 0.05 vs. 0.29 +/- 0.03) (P < 0.01), while in platelets these changes were opposite (0.11 +/- 0.05 vs. 0.25 +/- 0.05) (P < 0.01). Compared to these significant changes, salt loading (200 mEq NaCl/day) for 6 days decreased PRA(0.49 +/- 0.10 vs. 1.05 +/- 0.17 ng/l/s; P < 0.01) and induced the opposite changes in the ratio of AT1 receptor/GAPDH mRNA. These data suggest that AT1 receptors in human blood cells may be of two different types--platelets and mononuclear leucocytes.

Adult↗
PubMed1995

Effects of short-term administration of alpha-chlorohydrin on reproductive toxicity parameters in male Sprague-Dawley rats.

alpha-Chlorohydrin (alpha-CH) was administered orally at doses of 0, 2 or 8 mg/kg/day for 2 weeks to Sprague-Dawley male rats. At the end of the administration period or 2 weeks after withdrawal (one group also treated with 8 mg/kg for 4 weeks), males were mated (treatment with alpha-CH was continued throughout the mating period of 2 weeks) with untreated females, and underwent examination, including assessment of sperm, to determine fertility. No significant treatment-associated changes were observed in terms of body weight, food consumption, or weights of the testes, epididymides or prostate in either the 2 or the 8 mg/kg group. Although there were no significant differences in sperm number, viability or maturation rate between either of the treated groups and the control group, sperm motility in the 8 mg/kg group observed after 2 hours incubation and sperm activity in groups treated with 8 mg/kg observed immediately after collection or after 2 hours incubation, as well as in the 2 mg/kg observed after 2 hours of incubation were significantly decreased. Two weeks after withdrawal (8 mg/kg group only), sperm motility and activity were no longer decreased. Histopathological examination of the testes after 4 weeks of alpha-CH administration disclosed no abnormalities on staining with Hematoxylin-Eosin after fixation in Bouin's solution. All treated male rats copulated with untreated females, but no pregnancy resulted from mating in the 8 mg/kg continuous administration case. There were no significant differences between the control and 2 mg/kg groups in numbers of corpora lutea and implantations in animals becoming pregnant. Two weeks after withdrawal, male rats treated with 8 mg/kg copulated and impregnated females. These findings suggest that evaluation of male fertility is possible within or following a 2-week treatment period for compounds like alpha-CH which have no toxicological, histopathological or sperm morphological effects, and that the use of several parameters for sperm examination is important in determining male fertility.

Animals↗
PubMed1995

Ten-year follow-up study of thyroid function in euthyroid patients with simple goiter or Hashimoto's thyroiditis.

In an attempt to study the natural course of Hashimoto's thyroiditis and simple goiter, 74 euthryroid patients with Hashimoto's thyroiditis and 212 patients with simple goiter were followed for 10 years. In 204 patients with simple goiter (96.2%) it remained as a simple goiter throughout the observation period, whereas 8 patients (3.8%) later had Hashimoto's thyroiditis as evidenced by the appearance of circulating thyroid autoantibodies. These 8 patients had HLA typing significantly different from that of control subjects. None of the patients with simple goiter had hyperthyroid Graves' disease despite the fact that 17.5% of those patients had mild to moderate exophthalmos with either Moebius' sign or von Graefe's sign. In contrast, 12 patients with Hashimoto's thyroiditis (16.2%) had exophthalmos with Moebius' sign and/or von Graefe's sign, and 4 of 12 such patients later had hyperthyroid Graves' disease. TSH binding inhibitory immunoglobulin was detected in 3 of 4 such patients with hyperthyroid Graves' disease. Forty-nine patients with Hashimoto's thyroiditis (66.2%) still remained euthyroid but 20 of those (27.0%) turned into hypothyroidism during the 10-year follow-up.

Adolescent↗
PubMed1995

Effect of 14-membered ring macrolide therapy on chronic respiratory tract infections and polymorphonuclear leukocyte activity.

We studied the efficacy of the long-term administration of 14-membered ring macrolides in treating patients with diffuse panbronchiolitis (DPB) (34 patients) and bronchiectasis (BE) (40 patients). Oral administration of erythromycin (400 or 600 mg), roxithromycin (150 or 300 mg) or clarithromycin (200 or 400 mg) given daily for at least 2 months, was evaluated. The efficacy of erythromycin, roxithromycin, and clarithromycin in DPB was 19/24 (79%), 6/7 (86%), and 2/3 (67%), respectively. Efficacy of these agents in BE exceeded 50%. We determined the effect of these macrolides on the activity of polymophonuclear leukocytes (PMNs) obtained from healthy volunteers. There were no significant differences between the effects of these 14-membered ring macrolides and josamycin, a 16-membered ring macrolide which was previously found to be ineffective in treating DPB. Thus, the effectiveness of the 14-membered ring macrolides in treating DPB appears to depend on mechanism(s) other than alterations in PMN activity.

Adult↗
PubMed1995

The effects of aging on the rat bladder and its innervation.

1) Measurements of the cystometrogram, of the responsiveness of bladder muscle to pelvic nerve efferent stimulation and of the sensitivity of the pelvic nerve afferents to pressure and volume during distensions have been made in the bladders of young adult (2-3 months) and aged (26-29 months) rats, anesthetized with mixtures of urethane and chloralose. 2) The pressure-volume relationship differed in young adult and aged rats. The bladders of the aged rats held up to nearly six times the volume of the young animals, and these volumes were accommodated at lower pressures in the aged animals. The pressure at which micturition contractions appeared was similar in young adult and aged animals. 3) The passive pressure associated with each of a series of distending volumes was recorded when a pelvic nerve was cut unilaterally. The distal cut end of this cut pelvic nerve was stimulated for 10 s at 20 Hz, using square wave pulses of 10 V and 1.0 ms. The active pressure-volume relationship was constructed from this data. Both the active and the passive relationships were shifted to the right in the aged animals, and it was evident that aging was associated with a reduction in the maximal pressure generated during pelvic nerve stimulation. Also the change in intravesical pressure induced by bladder contraction was less in aged animals. 4) The most sensitive mechanoreceptor afferents appear to have pressure and volume thresholds that do not change significantly during aging. While the distension-sensitive afferents in the pelvic nerve appear to have a similar sensitivity to intravesical pressure in young adult and aged rats, they were less able to monitor volume in the aged animals. The stimulus response relationship for volume was often less steep in the aged animals. 5) In this study, aging was shown to be associated with a large increase in bladder volume and a reduced sensitivity of pelvic nerve afferents to volume, and a reduced ability to raise bladder pressure during contraction of bladder smooth muscle. The changes in bladder function associated with aging are discussed.

Aging↗
PubMed1995

Mechanistic understanding of enamel mineralization under fluoride regime.

In order to learn more about how the microenvironment for enamel mineralization is modified by fluoride at low concentrations (0 through 1 ppm) and how excess fluoride retards the degradation and removal of amelogenins, we studied precipitation reactions in an in vitro model utilizing a dialysis chamber. The results showed that, with the limited supply of Ca ions through the ultrafiltration membrane, the solution composition surrounding the seed crystals showed a proximity to the steady-state condition after 12-24 h equilibration. Major findings were that (a) fluoride overcame partially the inhibition of precipitation and growth reactions by enamel proteins and (b), with this accelerating effect of fluoride, the steady-state Ca concentrations in the media surrounding the seed crystals decreased substantially as a function of fluoride concentration. The overall results support the concept that the presence of fluoride in the mineralizing milieu can modify markedly the steady-state concentrations of mineral lattice ions, particularly decreasing free Ca2+ concentrations, which in turn may modulate protease activities in situ.

Amelogenin↗
PubMed1995

A new nitric oxide (NO) releaser: spontaneous NO release from FK409.

The remarkable vasorelaxant and anti-platelet effects of FK409 have been reported to be due to nitric oxide (NO) release. The purpose of the present study is to investigate the spontaneous NO-releasing pathway of FK409 in aqueous solutions. 1H-NMR spectra of FK409 suggested that the compound underwent a time-dependent elimination of the hydrogen atom at alpha-position of the nitro moiety (at the 5-position) in weakly alkaline solutions. In addition, the degradation of FK409 monitored by HPLC showed a pH-dependency accelerating with an increase of pH. These results revealed that the first step in the degradation of FK409 might be the hydroxyl ion-dependent subtraction of the hydrogen atom at the 5-position. On the other hand, NO release from FK409 also exhibited a pH-dependency, and the velocity of NO liberation was markedly enhanced above pH 6. Furthermore, a linear relationship between the rate of FK409 degradation and that of NO formation was observed, indicating that the rate-limiting step for NO formation is the same as that for degradation. Thus, the rate-limiting process of NO formation from FK409 is due to the deprotonation reaction of the hydrogen atom at the 5-position by hydroxyl ions. The deprotonation process appears to be an essential step for both FK409 degradation and NO release. On the basis of the results, a possible kinetic scheme for NO release from FK409 is proposed.

Buffers↗
PubMed1995

Induction of differentiation of HL-60 cells by the anti-fungal antibiotic, radicicol.

The anti-fungal antibiotic, radicicol, produced in the culture broth of Neocosmospora tenuicristata, was found to induce differentiation of HL-60 cells into macrophages from the following evidence: (1) it caused morphological changes into macrophage-like cells, (2) induced NBT (Nitrobluetetrazolium) reduction activity, (3) induced phagocytosis, and (4) induced alpha-naphthyl acetate esterase activity. The concentration of radicicol required to differentiate HL-60 cells is 50-100 ng/ml, and the incubation time required for commitment of differentiation is 16 hours. Flow cytometry analysis indicated that radicicol blocks the cell cycle of HL-60 cells at the G1 and G2 sites. In addition, radicicol induced reversal of the transformed phenotype of ras-transformed NIH3T3 cells (DT cells) at 25 ng/ml.

Antifungal Agents↗
PubMed1995

Clinorotation inhibits chondrogenesis in micromass cultures of embryonic mouse limb cells.

Studies of the response of mammalian chondrocytes to gravitational changes in vivo, in organ culture, and in cell culture show that chondrogenesis is reduced in microgravity or by unloading, and increased by low levels of excess g. To investigate the cellular responses to microgravity using a ground based model, micromass cultures were exposed to simulated weightlessness on two clinostats. For rotation on the large clinostat, cultures were set up in Rose chambers, and cells were videotaped and photographed at several time periods after rotation began. For the smaller clinostat, cultures were set up in T-flasks, and two axes of rotation for clinostated cultures were used. Stationary controls [+1 g, -1 g (upside-down), and sideways] as well as rotation controls were employed. Rotation rate was 30 rpm for both clinostatted cultures and rotation controls. Chondrocyte differentiation was assessed by cartilage specific alcian blue staining. Significantly fewer alcian blue stained nodules were present in clinostatted cultures than in stationary controls or rotation controls. Nodules that did not stain with alcian blue, probably due to unsulfated matrix were present in all cultures. The number of nodules in sideways controls was greater than in any other culture (108% of +1 g controls), probably due to ongoing stimulus of the cell via cytoskeletal components. The results show that chondrocytes in culture respond to changes in the gravity vector in a predictable manner, and that carefully controlled clinostat studies can be useful adjuncts to and predictors for spaceflight experiments.

Animals↗
PubMed1995

Degradation of cystathionine gamma-lyase in rat liver lysosomes: effect of leupeptin treatment.

Highly purified lysosomes from the livers of normal and leupeptin-treated rats were subjected to immunoblot analysis, using antibodies against rat liver cystathionine gamma-lyase. Normal lysosomes showed small amount of single band at about 40 kDa, whereas the leupeptin-treated lysosomes showed large amounts of a major band at about 40 kDa and a minor band at about 35 kDa. These observations suggest that cystathionine gamma-lyase is sequestered into lysosomes at the original subunit molecular weight and is degraded in the lysosome by way of the sequential formation of an intermediate with distinct molecular weight.

Animals↗
PubMed1995

[Serum phospholipase A2 activity in patients with aspirin-induced asthma].

Urinary excretion of leukotrienes is greater in patients with aspirin-induced asthma (AIA) than in other patients with asthma in remission, and is greater still during an aspirin-induced attack. We therefore hypothesized that increased phospholipase A2 (PLA2) activity leads to increased leukotriene synthesis when non-steroidal antiinflammatory drugs inhibit cyclooxygenase in patients with AIA, and that PLA2 activity increases further during an aspirin induced attack. To test this hypothesis, we measured the serum PLA2 activity in adult asthmatic patients, and compared the activity in those with AIA to the activity in those without AIA. The subjects were 43 patients with asthma in remission, 17 with AIA and 26 without AIA. Serum PLA2 activity was also measured before and after intravenous administration of lysine-aspirin in three patients with AIA and in one without AIA. Serum PLA2 activity was measured by radioimmunoassay. Serum PLA2 activity in patients with AIA, in those without AIA, and in healthy controls was 300.9 +/- 52.9, 294.4 +/- 65.3 and 171.7 +/- 41.8 pmol/ml/min, respectively. Serum PLA2 activity in asthmatic patients was significantly higher than in healthy controls (p < 0.01), but there was no difference between patients with and without AIA. Intravenous lysine-aspirin provoked asthmatic attacks in three patients with AIA. However, intravenous lysine-aspirin did not significantly change serum PLA2 activity in the three patients with AIA or in the patient without AIA. These results indicate that although PLA2 may be involved in the pathogenesis of bronchial asthma, it is not specific to AIA. Thus, the pathophysiology of AIA remains unclear and further investigation is needed.

Adult↗