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Biomedical subjects

T Sakata

Publications and source records attributed to T Sakata.

At least 307 records · Page 17Linked to original sources
PubMed1993

Suppression of food intake by apolipoprotein A-IV is mediated through the central nervous system in rats.

The aim of this experiment was to investigate whether the anorectic effect of apolipoprotein A-IV (apo A-IV) after lipid feeding is mediated via the central nervous system. Infusion of 0.5 micrograms of apo A-IV into the third ventricle failed to suppress food intake. Higher doses (1 micrograms or higher) of apo A-IV infused into the third ventricle inhibited food intake in a dose-dependent manner. In contrast, when apo A-I was infused into the third ventricle it had no effect on food intake. To further test the hypothesis that apo A-IV is an important factor controlling food intake, we administered goat anti-rat apo A-IV serum into the third ventricle of rats that were allowed food and water and lib. In all rats tested, this treatment resulted in enhanced food intake. In contrast, infusion of goat anti-rat apo A-IV serum failed to elicit such a response. Lastly, we determined the apo A-IV concentration in plasma and cerebrospinal fluid before and during active lipid absorption. Apo A-IV concentration in cerebrospinal fluid was about 1/20 that of plasma. Both serum and cerebrospinal fluid apo A-IV increased markedly as a result of feeding of lipid. In conclusion, we propose that apo A-IV may act centrally to control food intake.

Animals↗
PubMed1993

Psychology of computer use: XXX. Effects of presentation speed on pupil size using negative and positive CRTS.

The effects of presentation speed and both positive and negative CRT (cathode ray tube) displays on pupil size were studied. The pupillary areas of 12 female student volunteers were measured by infrared videopupillography. The three presentation speeds were no change for 12 sec., a change every 2 sec. for 12 sec., and a change every 1/2 sec. for 12 sec. Two-way analysis of variance showed that the pupil size in the negative displays was significantly larger than that in the positive displays. A difference in pupillary area results from different display speeds, irrespective of a difference in polarity.

Adult↗
PubMed1993

[Alcoholic liver injury accompanied with various metabolic and endocrinological disorders--a case report].

We report a young female case of alcoholic liver injury accompanied with various metabolic and endocrinological disorders. A 29 year-old woman was admitted because of general fatigue and hyperlipidemia. She was a heavy drinker. Laboratory data on admission revealed liver dysfunction and hyperlipidemia (type II b) with a quite high serum gamma-glutamyltranspeptidase (gamma GTP) level. The microscopic finding of the liver biopsy specimen showed fatty metamorphosis and ballooning of hepatocytes, and she was diagnosed as heavy alcoholic liver injury. The endocrinological examination revealed the elevated plasma cortisol level, though the urinary 17-hydroxycorticoids (17-OHCS) and 17-ketosteroids (17-KS) excretion and the plasma adrenocorticotropic hormone (ACTH) level were reduced. Cortisol secretion showed the normal circadian rhythm and the normal response to ACTH provocation. The levels of plasma triiodothyronine (T3), thyroxine (T4), and thyroid stimulating hormone (TSH) were also reduced. These endocrinological and metabolic disorders were normalized in company with recovery of the liver function by temperance, diet therapy and nutritional education. Thus, these abnormalities were considered to be resulted from the alcoholic liver injury and the effect of the ethanol to the hypothalamic-pituitary system.

Adult↗
PubMed1993

Thymic stroma-derived T-cell inhibitory factor (TSTIF) 1. TSTIF induces inhibition of antigen-stimulated T-cell proliferation.

The present study investigates the capacity of the MRL104.8a thymic stromal cell clone to modulate T-cell growth. The culture supernatant (SN) from the MRL104.8a stromal cell monolayer was added to cultures of Th-clones with or without T-cell receptor (TCR) stimulation as provided by antigen (Ag) plus splenic antigen-presenting cells (APC). The results demonstrated that the MRL104.8a SN containing IL-7 activity induced dose-dependent proliferation of Th cells when they were not stimulated with Ag/APC. In contrast, addition of the same SN to cultures of Th cells during stimulation with Ag/APC resulted in potent dose-dependent inhibition of their proliferation. IL-7 contained in the SN was neither responsible for, nor involved in the inhibition event, because the inhibition was not observed with rIL-7 and was not neutralized by anti-IL-7 antibody. The growth inhibition of the Th clone in the presence of Ag plus APC was also induced by IL-10 or TGF-beta. However, the MRL104.8a SN-induced growth inhibition was mediated by a factor distinct from these cytokines, because (1) IL-10 cDNA was not amplified in polymerase chain reaction (PCR) products derived from MRL104.8a cells; (2) TGF-beta cDNA was detected in the PCR products, but only marginal levels of TGF-beta activity in an active form were found in the MRL104.8a SN and the SN-induced inhibition was not prevented by anti-TGF-beta antibody; and (3) addition of rIL-7 to antigen-stimulated cultures containing rTGF-beta or rIL-10 induced IL-7 mediated Th proliferation, whereas the MRL104.8a SN-induced inhibition was still observed in the presence of excess rIL-7. Moreover, this factor, designated thymic stroma-derived T-cell inhibitory factor, was found to have a m.w. of 20-25 x 10(3) and to exhibit heparin-binding property. Thus, these results indicate that the MRL104.8a thymic stromal cell clone produces a potentially novel factor that induces inhibition of antigen-stimulated T-cell proliferation.

Animals↗
PubMed1993

[A familial case of DRPLA diagnosed by an autopsy associated with hemoglobinopathy (Hb Takamatsu)].

The patient first noticed general muscle stiffness at the age of 36. Two years later, she suffered from a tonic-clonic seizure which brought her to a hospital for the first time. Choreoathetoid movement, ataxia and cognitive deficit were apparent. At the age of 44, tonic-clonic seizures became more frequent and she was admitted to our hospital as being status epilepticus. After the cessation of clinical seizures, she became appllic. Gradual increase of atrophic changes in cerebrum, cerebellum and brain stem were observed by MRI and CT. Hematological study showed that she had abnormal hemoglobin, Hb Takamatsu. Four of her five children were clinically examined; all of them showed abnormal EEG findings; three being mentally retarded and had clinical generalized convulsive seizures; two had hemoglobinopathy (Hb Takamatsu). The patient died from sepsis at the age of 50 and the autopsy was carried out. The brain weighed 930 gram. Histological findings confirmed the diagnosis of dentato-rubro-pallido-luysian atrophy; neuronal loss accompanied by gliosis in dentate nuclei, red nuclei, lateral part of globus pallidus, and subthalamic nuclei. The coincidence of the hereditary traits of two independent diseases, DRPLA and familial hemoglobinopathy (Hb Takamatsu) suggests closeness of their genetic loci.

Atrophy↗
PubMed1993

Arachidonic acid metabolism in cells transfected with sense and anti-sense cDNA to annexin I.

Thymic epithelial cell line TEA3A1 produce prostaglandin E2 (PGE2) and express high levels of annexin I. In order to study the relationship between the levels of annexin I expression and the arachidonic acid metabolism, TEA3A1 cells transfected with expression vector containing full length annexin I cDNA in either sense or anti-sense orientation was studied. In the anti-sense cells where the level of annexin I was reduced, the PGE2 production was significantly lower. On the other hand, PGE2 production was significantly higher in sense cells where the production of annexin I was also higher than in control cells. Our results show that increased PGE2 production in sense cells was accompanied by higher levels of PLA2 enzymatic activities. These results suggest that the production of annexin I is positively associated with the phospholipase A2 enzymatic activity and the prostaglandin production in thymic epithelial cells.

Animals↗
PubMed1992

Role of colony-stimulating factor-1 in macrophage activation in tumor-bearing mice.

We previously reported a dramatically increased number of macrophages in tumor-bearing mice. In this study, we investigated the involvement of CSF in that phenomenon. CSF-1 responding cells as macrophages precursors increased significantly in number in the spleens of tumor-bearing mice as compared with those in normal mice. Splenic cells and sera from the tumor-bearing mice respectively expressed CSF-1 in mRNA and serum protein levels, but failed to express the other CSF (granulocyte-macrophage-CSF or IL-3). Nonadherent splenic mononuclear cells (< 0.5% macrophages) from normal mice proliferated and differentiated into mature macrophages in culture within 7 days with recombinant mouse CSF-1 (rCSF-1). Both macrophages harvested from tumor-bearing mice and those activated in vitro with rCSF-1 expressed mostly Mac-1, -2 (and -3) Ag, showed yeast phagocytosis, produced IL-1 but not IL-2 or IL-3, and displayed potent cytotoxicity against NK cell resistant Meth-A tumor cells. These macrophages also expressed lipocortin I mRNA and secreted lipocortin I protein, and suppressed mitogenic responses of splenic lymphocytes. rCSF-1-activated macrophages derived from nonadherent splenic cells expressed both CSF-1 and CSF-1 receptor (c-fms) mRNA. Administration of rCSF-1 into normal mice induced hemopoietic and immunologic alternations similar to those observed in tumor-bearing mice. These results suggest that CSF-1 is involved in the dramatic increase of macrophages in tumor-bearing mice, possibly through an autocrine or paracrine loop.

Animals↗
PubMed1992

Zucker obese rats: defect in brain histamine control of feeding.

Manipulation of hypothalamic histamine produced different effects on feeding between the Zucker obese (fa/fa) and their lean littermate rats (Fa/-). Infusion of a histamine H1-receptor antagonist into the third cerebroventricle elicited feeding in the lean and Wistar King A rats, but it did not affect feeding in the obese rats. To enhance hypothalamic neuronal histamine, thioperamide, and H3-receptor antagonist, was similarly infused. The lean and Wistar rats decreased their food intake after the infusion, but thioperamide produced no significant effect on feeding in the obese rats. Infusion of histamine into the third cerebroventricle mimicked the effects of thioperamide on feeding: reduction of food intake in the lean and Wistar rats, but no significant change in the obese rats. Hypothalamic histamine of the obese rats (0.430 nmol/g) was significantly lower than the lean (1.209 nmol/g) and Wistar rats (4.838 nmol/g). The histamine concentration of the cerebral cortex in the obese rats was also lower than the non-obese animals. The results indicate that the feeding abnormality of Zucker obese rats may be at least due to disturbance of histamine suppressive signals both at presynaptic and postsynaptic levels.

Animals↗
PubMed1992

Identification of IL-7-dependent bone marrow-derived Thy-1-B220- lymphoid cell clones that rearrange and express both Ig and T cell receptor genes.

Bone marrow stromal cell lines and lymphoid cell lines were co-established from the Whitlock-Witte type of long term liquid cultures of MRL/1 and C57BL/10 (B10) (Thy-1.1) bone marrow cells. The present study investigates the immunologic nature of parental and cloned lymphoid cell lines. Both strains of parental lines and their clones did not grow alone but proliferated on the monolayers of co-established parental stromal cell lines from a syngeneic or alternative strain. When various lymphokines or cytokines were tested for their capacity to support the growth of these lymphoid cell clones, only IL-7 could substitute for the growth-promoting function of stromal cells. These IL-7-dependent clones expressed neither Thy-1 nor B220 Ag. However, all of them from two strains were found to rearrange synchronously H chain of Ig as well as gamma chain of TCR genes. Some of the clones transcribed a mature size of IgH mRNA. Co-expression of mRNA for lambda 5 but not for IgL chain (kappa, lambda) genes resulted in the generation of cell surface mu chain in these clones. Other clones expressed a smaller size of IgH mRNA without exhibiting surface mu chain. Irrespective of the differences in IgH rearrangements and its mRNA expression, a mature size TCR gamma mRNA was detected in all of the clones. Thus, these results demonstrate the existence of untransformed (IL-7-dependent) immature lymphoid cells rearranging both Ig and TCR genes. Their unique features concerning cell surface markers (B220- mu+), specific growth factor requirement, and various modes of Ig/TCR gene rearrangements are discussed in the context of early lymphoid development.

Animals↗
PubMed1992

Regulatory effects of interleukin-7 on renal tumor infiltrating lymphocytes.

Biological therapy using a combination of lymphokine and tumor infiltrating lymphocytes (TILs) is a new approach to the treatment of patients with advanced cancer. To improve the potency of TILs, new cytokines with T-cell stimulatory effects used alone or in combination with interleukin-2 (IL-2) are currently being investigated. We have studied the effect of interleukin-7 (IL-7) on TILs derived from renal cell carcinoma. Our data demonstrated that five of ten TILs proliferated in response to IL-7 alone. This proliferative response was 73-90% less than that obtained with IL-2 alone. The use of IL-7 plus IL-2 resulted in a 1.2- to 4.7-fold increase in proliferation of six of ten TILs compared with IL-2 alone. IL-7-driven TIL growth was consistently blocked by anti-IL-2, anti-IL-2R and anti-IL-7 antibodies (37.2%, 41.6% and 82.2% suppression, respectively). The expression of IL-2 receptors was also significantly increased in the presence of IL-7 or IL-7 phytohemagglutinin (40.6 + 3.8 and 72.5 + 1.5). In comparison with IL-2, IL-7 treatment was associated with a decrease in CD56 (46.3% +/- 19 vs 10% +/- 4.9) and increase in CD3 (29.3% +/- 12 vs 73% +/- 6.4) and CD4 (19.3% +/- 15 vs 58% +/- 10). These studies suggest that in some renal TILs, IL-7 and IL-2 can have a synergistic proliferative effect. The IL-7 stimulatory effect appears to be mediated via both an IL-2 pathway and an IL-7-independent pathway.

Antigens, CD↗
PubMed1992

Superficial bladder cancer treated by total cystectomy: tumour characteristics and patient survival.

Of 113 patients with bladder cancer who underwent total cystectomy from January 1980 to December 1990, 30 (27%) had superficial tumours (pTa, pTis, and pT1). Nineteen of these 30 patients (63%) were primarily treated by total cystectomy and the remaining 11 (37%) had a past history of treatment for bladder cancer. Major reasons for choice of total cystectomy were multifocal tumours, frequent recurrence, and diffuse carcinoma in situ. Histologically stage pT1, grade 3 tumours were frequently accompanied by carcinoma in situ and often by lymphatic invasion. None of the 24 patients undergoing pelvic lymphadenectomy had lymph node metastasis. Of 25 male patients 15 (60%) underwent simultaneous prophylactic urethrectomy. Two of the remaining 10 males (20%) not undergoing this additional operation died of subsequent urethral recurrence. The 5-year actuarial survival rate was 80% for the 30 patients when all causes of death were considered. It was concluded that patients with superficial bladder cancer who undergo total cystectomy without prophylactic urethrectomy require close follow-up with urethral washings for cytology to detect early urethral recurrence, an important determinant for survival.

Adult↗
PubMed1992

Anorexia induced by toxohormone-L isolated from ascites fluid of patients with hepatoma.

To ascertain anorexigenic effect of toxohormone-L, a polypeptide extracted and purified from ascites of patients with hepatoma were infused into the rat third cerebroventricle. Food intake decreased on the first day after infusion of an optimum dose of 10.0 micrograms (p less than 0.05). The suppressive effect on feeding was linearly dose dependent (p less than 0.05). Meal size and latency to the first meal decreased in the 12-h dark period, and the first and the second 4-h cumulative blocks after infusion of a 10.0 micrograms dose (p less than 0.01 for each). The suppressive effects on total food intake and meal size were completely recovered within 24 h after infusion. Neither postprandial intermeal interval nor eating speed was affected. Periprandial drinking, a ratio of water intake to food intake, was not affected after infusion of 5.0 and 10.0 micrograms toxohormone-L. Infusion of a 10.0 micrograms dose showed no effect on ambulation. These findings suggest that anorexia and cachexia produced in cancer patients may essentially be due to the suppressive effect of toxohormone-L on food intake.

Animals↗
PubMed1992

Acceleration of tail pinch-induced feeding in rats by analgesic effect of neurotropin.

Mechanisms of tail pinch-induced feeding and effects of neurotropin (NSP), an extract from the inflamed skin of rabbit inoculated with vaccinia virus, on behavioral responses were investigated in rats. Treatment of a 5-min tail pinch (tail pinch I) induced feeding response. An intensified 15-min tail pinch (tail pinch II) provoked emotional reactions besides feeding behavior. The rate of food intake (food intake/tail pinch duration) during tail pinch II was less than that at tail pinch I. Intraperitoneal administration of NSP (100 mg/kg/day) by itself produced no remarkable change in feeding or emotional behavior. However, NSP-treated rats increased eating size and prolonged eating duration during tail pinch I. Pretreatment of NSP increased feeding behavior more potently at tail pinch II than at tail pinch I and decreased the incidence of emotional reactions at tail pinch II. The results suggest that NSP, by its analgesic action, may modulate behavioral responses during tail pinch treatment through selective blockade of the nociceptive and feeding-inhibitory information, but not through the nonnociceptive and feeding-excitatory signals.

Analgesics↗