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Biomedical subjects

S Sakata

Publications and source records attributed to S Sakata.

At least 199 records · Page 11Linked to original sources
PubMed1989

[Changes in anti-thyroid hormone and anti-thyroglobulin antibodies during thyroid hormone(s) or prednisolone treatments in 3 cases of Hashimoto's thyroiditis].

We have experienced 3 cases of Hashimoto's thyroiditis with anti-thyroid hormone antibodies. Changes in titers of anti-thyroglobulin(Tg) and anti-thyroid hormone antibodies during 6 year (Cases 1 and 2) and 7 year (Case 3) observation periods were examined in each case. Cases 1 (13-year-old) and 2 (10-year-old) are sisters with hypothyroidism whose chief complaint was short stature. They were diagnosed as having Hashimoto's thyroiditis by needle biopsy of the thyroid gland. Presence of anti-thyroid hormone antibodies were found in the sera of both cases (Case 1: anti-thyroxine(T4) antibodies, Case 2: anti-triiodothyronine(T3) antibodies). They were treated with synthetic T4 or combined therapy of T3 and T4, and serial sera obtained during the 6 year treatment period were tested for the titers of anti-Tg and anti-thyroid hormone antibodies. Case 3 (23-year-old female), who was diagnosed as having Hashimoto's thyroiditis associated with systemic lupus erythematosus (SLE) and Sjögren's syndrome had been treated with prednisolone(PSL) for 8 years. After one year of strating the treatment, she was found to have unusually low serum T3 measured by radioimmunoassay. Further examination revealed the presence of anti-T3 antibodies in her serum. Serial sera obtained during the 7 year observation period were tested for the titers of anti-Tg and anti-T3 antibodies. In cases 1 and 2, replacement therapy with thyroid hormone resulted in the decrease of titers of anti-thyroid hormone antibodies. In addition, increase in serum TSH concentrations was accompanied with increased titers of anti-Tg and anti-thyroid hormone antibodies in all 3 cases. The exact mechanism for it is not clear.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1989

[Fluctuations in the titers of anti-thyroid hormone and anti-thyroglobulin antibodies in 4 cases of Graves' disease during long-term treatment period].

We studied 4 cases of Graves' disease with anti-thyroid hormone antibodies. Changes in the serum levels of triiodothyronine(T3), thyroxine(T4), free T4, thyrotropin(TSH), and thyroglobulin(Tg), as well as titers of anti-Tg antibodies, anti-thyroid hormone antibodies, anti-TSH receptor antibodies(TRAb) and anti-microsomal antibodies(MCHA) during 2 10 years' treatment periods were examined in each case. Case 1; A woman, who was diagnosed as having Graves' disease when she was 10 years old, had been treated with methimazole(MMI) or propylthiouracil(PTU). Treatment with the antithyroid drug had been discontinued by herself when she was 19 years old until she was 24 years old, when she was pregnant and consulted our hospital. Since her serum levels of T3 were unusually high, examination of her serum for the presence of anti-T3 antibodies was done. The presence of anti-T3 antibodies in her serum was confirmed. Case 2; A woman, who was diagnosed as having Graves' disease at the age of 41, had been treated with MMI or PTU. Presence of serum anti-T3 antibodies was found in a screening test for the antibodies. Serial sera were obtained during the 5 year observation period when she was treated with MMI, PTU, and subtotal thyroidectomy. Titers of anti-Tg antibodies in her sera were in the normal range. Case 3; A woman, who was diagnosed as having Graves' disease at the age of 11, had been treated with MMI or PTU. Presence of anti-T3 and anti-T4 antibodies were found in her sera in a screening test. Serial sera obtained during the 4 year treatment period were tested. Case 4; A woman, who was diagnosed as having Graves' disease at the age of 14, had been treated with MMI. Presence of anti-T3 and anti-T4 antibodies was found in her sera in a screening test. Serial sera obtained during the 2 year treatment period were tested. Titers of anti-Tg were increased when the levels of TSH or titers of TRAb were increased. The results suggested that TSH and TRAb, which are thyroid stimulating substances, increased serum levels of Tg, which resulted in the increase of titers of anti-Tg. Because of the possibility that administration of PSL could modify B lymphocyte functions, periods during which PSL was administered were excluded from the examination of the correlation between Tg concentrations or titers of anti-Tg and titers of anti-thyroid hormone antibodies, as in Cases 2 and 4, respectively.(ABSTRACT TRUNCATED AT 400 WORDS)

Adolescent↗
PubMed1989

Selective enhancement of intratumoural blood flow in malignant gliomas: experimental study in rats by intracarotid administration of adenosine or adenosine triphosphate.

We studied the effect of intravenous and intracarotid infusion of adenosine and adenosine triphosphate (ATP) on the regional blood flow of intracerebrally transplanted RG-C6 tumours in rats, using the hydrogen clearance method. The intracarotid administration of adenosine or ATP selectively increased blood flow in the tumour, but did not produce any significant change either in the regional cerebral blood flow of the extratumoural ipsilateral hemisphere or in the ipsilateral hemisphere without tumour. The intracarotid administration of ATP at a dose of 10 micrograms/kg/min produced the most effective increase in the tumour blood flow (+51.5 +/- 16.8%). In contrast, both the intravenous administration of adenosine and that of ATP failed to increase tumour blood flow. These results may possibly indicate that intracarotid administration of the adenosine or ATP might contribute in selectively enhancing the delivery of anti-cancer agents to malignant brain tumours.

Adenosine↗
PubMed1989

A case of Graves' disease associated with polymyositis.

A patient with Graves' disease associated with severe muscle weakness who was finally diagnosed as polymyositis by pathological examination of the muscle is reported. A 28-year-old women was incidentally found to have hyperthyroidism when she consulted a hospital for the evaluation and treatment of anemia in 1979. She was treated with methimazole for approximately a month when she stopped the medication by herself. Approximately two yr later (Nov. 4, 1981) she consulted another hospital with complaints of palpitation and muscle weakness. Diagnosis of hyperthyroidism due to Graves' disease and thyrotoxic myopathy were made, followed by the treatment with radioiodine (4 mCi of 131I). She was further treated with propylthiouracil (PTU). Four yr after the treatment, serum thyroid hormone concentration declined to the lower level than normal and serum TSH concentration increased. She was subsequently treated with synthetic I-T4. Despite the fact she became euthyroid with the treatment, muscle weakness as well as elevated concentrations of muscle enzymes were not improved. Muscle biopsy was made in July 1983, and she was diagnosed as immune polymyositis and treatment with prednisolone and cyclophosphamide in addition to PTU or I-T4, was started. With the treatment, serum LDH decreased to the normal range. However she still has muscle weakness and serum concentrations of CPK and aldolase are still in higher levels than normal range.

Adult↗
PubMed1989

Thyroid hormone autoantibodies (THAA) in three sisters: a four-year follow up.

We have found three sisters who had thyroid hormone autoantibodies (THAA) in serum. Two of them were hypothyroid due to Hashimoto's thyroiditis. They were treated with synthetic thyroxine (T4) (Case 1) or T4 and triiodothyronine (T3) (Case 2). The other sister (Case 3) was euthyroid throughout the investigation period. Changes in the titers of THAA, antithyroglobulin (Tg) antibodies as well as in the concentrations of thyrotropin (TSH), and total and free thyroid hormones (T3, T4, FT3, and FT4) in sera from each patient were examined for four years. A significant positive correlation was observed between titers of THAA and anti-Tg antibodies in both Case 1 (anti-T3 and anti-T4) and 2 (anti-T4). On the other hand, a significant negative correlation between titers of anti-T3 and anti-Tg antibodies was observed in Case 3. These results suggest that antigen of THAA might be Tg in Case 1 and 2 and mechanism(s) of the production of THAA of Case 1 might be different from that of Case 1 and 2 in terms of their antigen or immune recognition of Tg.

Adolescent↗
PubMed1989

Effect of 8-anilino-1-naphthalene sulfonic acid (ANS) on the interaction between thyroid hormone and anti-thyroid hormone antibodies.

Effect of 8-anilino-1-naphthalene sulfonic acid (ANS) on the interaction between thyroid hormone and anti-thyroid hormone antibodies was examined. Addition of 5.1 x 10(6) or 6.3 x 10(6) molar excess of ANS, respectively, enhanced the binding of 125I-T3 or 125I-T4 to their respective autoantibodies. However, further increase in ANS concentration resulted in a decrease in binding. These results suggest that the optimum concentration of ANS for the detection of anti-thyroid hormone antibodies is 5 approximately 6 x 10(6) molar excess of ANS to 125I-T3 or 125I-T4. On the other hand, addition of 10(4) molar excess of ANS concentration decreased the binding of 125I-insulin to anti-insulin antibodies. It was therefore suggested that the effect of ANS could be a nonspecific one and likely due to its negative charge.

Anilino Naphthalenesulfonates↗
PubMed1989

Simultaneous occurrence of medullary and follicular carcinoma in the same thyroid lobe.

A rare case of the simultaneous development of medullary and follicular carcinoma of the thyroid gland in a 51-year-old Japanese woman is examined. A preoperative diagnosis was made by needle aspiration cytology. Neoplastic cells of the medullary carcinoma were positive for calcitonin and carcinoembryonic antigen, whereas the tumor cells of the follicular carcinoma were negative for these substances. This case presents evidence that, in rare cases, two malignant epithelial neoplasms of different origins can occur in the same lobe of the thyroid.

Adenocarcinoma↗
PubMed1989

Temporal changes of plasma erythropoietin level in hypobaric hypoxic mice and the influence of an altered blood oxygen affinity.

Temporal changes of plasma erythropoietin (Epo) in mice exposed to hypobaric hypoxia were studied by a fetal mouse liver cell culture method. Since a colony formation inhibitory activity was found in the mouse plasma, thirteen pretreatment procedures for bioassay were compared and the procedure of shaking with chloroform followed by dialysis was concluded to be the best. When normal mice (P50 = 40.4 +/- 2.2 Torr) were exposed to hypoxia of 350 Torr, the plasma Epo level was elevated, with peak at the 2nd to 3rd day, and afterwards declined gradually. On the contrary, cyanated mice (P50 = 30.1 +/- 1.5 Torr) showed much less of the Epo response when exposed to 350 Torr. Under 200 Torr hypoxia, both mice exhibited a similar and remarkable extent of the response. These results suggest that the renal Epo-producing tissue or its oxygen-sensing system is less hypoxic in cyanated mice than in normal mice under 350 Torr, and that the physiologically optimal oxygen affinity of blood is variable depending on hypoxic degrees. The fact that the inhibitory activity showed an inverse temporal change to that of Epo, suggested a possible important role of this activity in the regulation of erythropoiesis under hypoxia.

Administration, Oral↗
PubMed1989

Hb Hope, beta 136(H14)Gly----Asp, in a diabetic Japanese female and its functional characterization.

A beta-variant hemoglobin, first misjudged as a marked elevation of Hb A1, was found in a 68-year-old Japanese female with diabetes mellitus. This hemoglobin was isolated by Bio-Rex 70 chromatography combined with chromatofocusing, and was found to be Hb Hope, beta 136(H14)Gly----Asp, by classical and high performance liquid chromatographic peptide mapping techniques. Intrinsic oxygen affinity of this hemoglobin was approximately one-third as compared with that of Hb A0. This property was still observed in the constituent beta subunits isolated. Effects of such allosteric effectors as H+ (at a fixed concentration of Cl-), anion (Cl-), 2,3-diphosphoglycerate and carbon dioxide were more or less depressed. Among others, a marked reduction in the carbamate effect should be noted in a structural interpretation of the functional modifications. Subunit cooperativity, on the contrary, was not different from that in Hb A0 (n = 2.8-2.9). Explanation of these altered functions were attempted on the basis of the altered structure. The reduced stability of Hb Hope is also described.

Aged↗
PubMed1989

Dissociated mesencephalic responses to medial and ventral thalamic nuclei stimulation in rats. Relationship to analgesic mechanisms.

To investigate the mechanism of analgesia noted with electrical stimulation of the thalamic sensory relay nucleus and medial thalamus, modulations of neuronal activities in the periaqueductal gray matter (PAG) were studied in response to electrical stimulations of the ventroposterolateral nucleus (VPL) and parafascicular nucleus (Pf) and to peripheral noxious stimulations in rats. Extracellular single-unit activities were recorded from 102 neurons in the PAG and the adjacent area in animals under halothane anesthesia. A large population (83%) of the PAG neurons reacted to Pf stimulations with a predominantly excitatory response, whereas smaller numbers (43%) responded to VPL stimulations. There was a significant correlation between the response characteristics of Pf and noxious stimulations, whereas no correlation was found between VPL and noxious stimulations. The PAG neurons that were verified antidromically to project to the nucleus raphe magnus showed a similar pattern of response. The excitatory response to the Pf stimulation was partially attenuated by systemic administration of naloxone, whereas that to the VPL stimulation was not affected. These results suggest that part of the analgesic mechanism of medial thalamus stimulation involves activation of the descending pain suppression system by exciting the PAG neurons through the opioid system, while the analgesia produced by sensory relay nucleus stimulation does not involve the PAG neurons or the opioid system.

Afferent Pathways↗
PubMed1989

[A study on the development of message-production in the referential communication].

The purpose of this study was to examine the development of message-production in a referential communication paradigm. Children (3-12 years) were asked to mention the associative encodings of two kinds of figures and then verbally communicate the figures to the adult and peer listeners. Differences in content and mode of encoding under the associative and communicative conditions were analyzed. Five-year-olds showed more changes of mode than three-year-olds. As for the changes of content, however, five-year-olds showed less than the others did. It was concluded that in the development of message-production, the changes of mode began to appear simultaneously when the associative encodings of the figures became stable, and afterwards the changes of content appeared. Differences between the messages for the adult and peer listeners were also analyzed.

Adult↗
PubMed1989

[Salvage radiotherapy of recurrent breast cancer].

During 1972-1986, 217 cases of breast cancer patients following radical mastectomy received postoperative radiotherapy and chemotherapy at Chiba Prefectural Cancer Center Hospital. All patients had operable tumor (T1-3), and radiation was directed to the chest wall and regional nodes. A total of 57 patients have relapsed. Fourteen patients experienced isolated local-regional recurrence (11 chest wall, 2 supraclavicular and 1 axilla), and other cases developed distant metastases. Of these, forty patients (70%) died with different metastatic areas within three years, although salvage radiotherapy was effective in controlling the local or metastatic tumor. Of ten patients who survived three years or longer were, six were bone metastaes and four were chest wall recurrence.

Adult↗
PubMed1989

[Effect of isoproterenol on regional myocardial oxygen balance in dog hearts with coronary stenosis].

Effects of intravenous and intracoronary isoproterenol on oxygen balance in the regional myocardium as well as on coronary hemodynamics were investigated in eight dogs with coronary stenosis under droperidol-fentanyl anesthesia. From these observations, the effect of an increase in myocardial contractility per se on regional myocardial oxygen balance was deduced. After intravenous isoproterenol of 0.5 microgram.kg-1, oxygen tension at the regional subendocardium decreased (23.7--15.4 mmHg) although transmural blood flow increased (26.0--41.4 ml.min-1). Function of the whole heart improved; heart rate increased (85--161 beats.min-1); and aortic blood pressure decreased (94--60 mmHg). After intracoronary isoproterenol of 0.005 microgram.kg-1, oxygen tension at the regional subendocardium slightly but significantly increased (22.8--25.4 mmHg). Although transmural blood flow (27.6--36.6 ml.min-1) and cardiac function improved, heart rate (83--93 beats.min-1) and aortic blood pressure (106--104 mmHg) remained at the pre-isoproterenol level. The results suggest that oxygen balance at the regional subendocardium is deteriorated through tachycardia and hypotension and a vasodilatory effect is seen largely at the subepicardium after isoproterenol to the heart with coronary stenosis, and that an increase in myocardial contractility per se does not deteriorate the oxygenation at the subendocardium.

Animals↗
PubMed1988

Effects of thalamic parafascicular stimulation on the periaqueductal gray and adjacent reticular formation neurons. A possible contribution to pain control mechanisms.

To investigate the mechanism of analgesic effect of electrical stimulation of the thalamic parafascicular nucleus (Pf), we studied modulations of neuronal activities in the periaqueductal gray (PAG) and the adjacent reticular formation (RF) in response to Pf electrical and peripheral noxious stimulations in the rat. Extracellular single unit activities were recorded from 129 neurons in the PAG and adjacent RF under light halothane anesthesia. Pf stimulation caused neuronal responses in approximately 80% of the PAG and adjacent RF neurons, and noxious stimulation in 75%, with predominant excitatory responses to either stimulation. When the responses to the two stimuli were tested in the same neurons (n = 69), 91% responding to noxious stimuli also responded to Pf stimuli, again with predominant excitatory responses to either stimulation. The PAG and adjacent RF neurons that were verified antidromically to project to the nucleus raphe magnus (NRM), showed a similar pattern of response (n = 20). These results suggest that a sizeable population of neurons in the PAG and adjacent RF receives excitatory effects from the Pf and noxious afferents, and that part of these neurons projects to the NRM, which inhibits the dorsal horn cells of the spinal cord (the descending pain suppression system). Thus, part of the mechanism of the analgesic effects of Pf stimulation is due to activation of the descending pain suppression system by exciting the PAG and adjacent RF neurons. A possible role of noxious afferents on the negative feedback to pain mediation through this descending system also has to be considered.

Animals↗
PubMed1988

Effects of high O2 affinity of blood on oxygen consumption (VO2) of dog gracilis muscle at varying O2 delivery.

To clarify the influence of high O2-affinity blood on oxygen consumption by peripheral tissue, we perfused the dog gracilis muscle alternately with normal and low P50 blood at constant CaO2 and varying blood flows. VO2 was plotted against O2 delivery which was a product of CaO2 and blood flow. VO2 of the resting dog gracilis muscle was O2 delivery-dependent below a critical O2 delivery of 0.40 ml/min.100g, but became delivery-independent above this level. This relationship was essentially the same as that observed in rat skeletal muscle (Kolár and Janský, 1984), and was independent of the O2 affinity of blood, both qualitatively and quantitatively, although the PVO2 was significantly lower in the perfusions with the high affinity blood than in those with normal blood. The average PVO2 value by which the delivery-dependent and -independent VO2 regions were separated decreased from 33 Torr in the normal perfusions to 20 Torr in the high O2 affinity perfusions. In conclusion, the elevation of blood O2 affinity does not induce any reduction in VO2, and thus hypoxia, in resting skeletal muscle under normoxic conditions when O2 delivery is not below the critical level.

Animals↗
PubMed1988

Wide variation of myoglobin contents in gizzard smooth muscles of various avian species.

We determined myoglobin contents of gizzards (muscular stomach) and breast muscles in 34 avian species by a modification of Reynafarje's spectrophotometric procedure. The birds were apparently differentiated into two groups in respect of the gizzard, one with a high myoglobin content (7.74 +/- 1.81 mg/g muscle) and the other with a low (1.54 +/- 0.41 mg/g). In the former group of 15 species all but one were herbivorous, and all but one were carnivorous or else omnivorous in the latter group of 19 species. The myoglobin level was considered to closely correlate with mechanical performance and therefore oxygen demands of the gizzards. It might also be relevant to a circulatory situation during the tonic contractions of this organs.

Animals↗