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Biomedical subjects

T Fukuda

Publications and source records attributed to T Fukuda.

At least 937 records · Page 52Linked to original sources

The remarkable proliferation of helper T cell subset in response to autologous thyrocytes and intrathyroidal T cells from patients with Graves' disease.

We have studied cellular interactions among thyrocytes, intrathyroidal T cells and peripheral blood T cells from Graves' patients. In the autologous mixed lymphocyte reaction of Graves' patients, CD4+ cells were able to proliferate vigorously against autologous non-T cells, whereas CD8+ cells responded weakly to non-T cell stimulators. Furthermore, the proliferative response of the CD4+ 2H4+ suppressor-inducer T cell subset was increased like that of the CD4+ 2H4- helper T cell subset. In contrast to peripheral blood non-T cell stimulators, thyrocytes and intrathyroidal T cells had the ability to activate the CD4+ 2H4- helper T cell subset but were not able to cause proliferation both of CD4+ 2H4+ suppressor-inducer T cell and CD8+ suppressor/cytotoxic T cell subsets. The marked reduction in proliferative responses of CD4+ 2H4+ cells and CD8+ cells could not be attributed to a difference in kinetics or altered response to variable number of stimulator cells. On the basis of these findings, it is suggested that the concentration of the helper T cell subset may be progressively increased and suppressor circuits may be unable to be activated in thyroid tissues. These abnormalities in cellular interactions may induce the excessive production of autoantibodies.

Adolescent↗

Bipotential cell differentiation of KU-812: evidence of a hybrid cell line that differentiates into basophils and macrophage-like cells.

KU-812-F is a subclone of KU-812, which has cytological features similar to the parent clone, and which carries the Philadelphia chromosome. We studied the effects of various chemical agents and serum-free culture (SF-C) condition on its differentiation. The KU-812-F subclone differentiated into macrophage-like cells with phorbol myristate acetate (PMA), but not with other agents. Unexpectedly, under SF-C, KU-812-F cells differentiated into mature basophil-like cells, and the histamine content of cell lysates increased in proportion to maturation. The addition of the condensed supernatant of SF-C promoted the cloning efficiency of KU-812-F cells in semisolid SF-C, whereas the cloning efficiency was reduced in SF-C alone. KU-812-F cells expressed myelomonocytic antigens. Additionally, My4 was induced with PMA and SF-C, but less often. HLA-DR was not expressed in any culture conditions, despite blastic morphology of KU-812-F cells or macrophage-like cells induced with PMA. The IgE receptor could not be demonstrated under any conditions. Correspondingly, immature and mature KU-812-F cells did not respond to anti-IgE or concanavalin A (con A), while histamine release was induced with PMA. In conclusion, KU-812-F belongs to the myeloid cell lineage and is at least a bipotential cell that can differentiate into basophils and macrophage-like cells. Although the functions appear to be dissimilar to those of normal basophils, the KU-812-F cell line may be a good model for basophil differentiation. Moreover, KU-812-F cells may provide new insights because they grow in semisolid culture by an autostimulating mechanism.

Basophils↗

[Magnetic resonance imaging (MRI) of pituitary adenomas].

MRI of 20 patients, 17-82 years old, with pituitary adenomas confirmed histopathologically, and 30 normal patients without pituitary dysfunction were reviewed. The studies were performed with a 0.5 Tesla MR scanner with a slice thickness of 10 mm. Inversion recovery sequences were employed as T 1-weighted examination, with repetition time (TR) of 2100-2500 msec, an inversion time (TI) of 600 msec and an echo time (TE) of 40 msec. The T 2-weighted examination had a TR of 1800-2500 msec and a TE of 120 msec. T 1-weighted images were obtained in all cases and T 2-weighted images in 14 cases. Spin echo images with a TR of 600-1000 msec and a TE of 40 msec (SE 40/600-1000) were also obtained in 14 cases. On T 1-weighted images, 20 adenomas were classified into six groups, according to their signal intensities; marked low intensity (1), low intensity (1), isointensity (11), high intensity (3), marked high intensity (1) and mixed intensity (3). On T 2-weighted images, 14 adenomas were classified into five groups; low intensity (1), isointensity (2), high intensity (4), marked high intensity (6) and mixed intensity (1). On SE 40/600-1000 images, 14 adenomas were also classified into four groups; low intensity (8), high intensity (2) and mixed intensity (3). Two adenomas with recent intratumoral hemorrhage had marked high intensity on both T1 and T2-weighted images. SE 40/600-1000 images were useful in evaluating the size and the extent of the visual pathway was best appreciated on IR images. Comparison between normal and involved cavernous sinus by adenomas was made.

Adenoma↗

[Effects of the pelvic and hypogastric nerve transection on the micturition cycle in the decerebrate dogs].

The effect of the transection of the pelvic and hypogastric nerves on the whole micturition cycle including the collecting and emptying phases was evaluated on the decerebrate dogs which exhibit highly consistent urodynamic parameters during a series of micturition cycles. Urodynamic parameters of each phase before and after each nerve transection were measured by pressure flow electromyographic studies and compared using the paired t test. Urodynamic parameters in the collecting phase consisted of threshold volume, threshold pressure, opening pressure and bladder compliance. Urodynamic parameters in the emptying phase consisted of voided volume, residual volume, residual ratio, contraction pressure, maximum flow rate and voiding time. Unilateral pelvic nerve transection produced a significant increase in threshold volume and bladder compliance and a significant decrease in threshold pressure during the collecting phase. There was a significant increase in residual volume and residual ratio and a significant decrease in contraction pressure and maximum flow rate during the emptying phase. After bilateral pelvic nerves transection, bladder did not contract and overflow incontinence occurred. Therefore, the pelvic nerves are considered to play an important role in both the collecting and emptying phases. Unilateral hypogastric nerve transection produced a significant decrease in threshold volume, threshold pressure and opening pressure during the collecting phase. There was a significant decrease in contraction pressure during the emptying phase. Bilateral pelvic nerve transection produced a significant decrease in threshold volume, threshold pressure and opening pressure, and a significant increase in bladder compliance during the collecting phase. There was a significant decrease in voided volume and contraction pressure during the emptying phase. Therefore, the hypogastric nerves are considered to play a certain role in the collecting phase.

Animals↗

[Effect of bunazosin on lower urinary tract function in the decerebrated dog].

The effect of bunazosin on the lower urinary tract function was studied by combined recording of cystometry and sphincter electromyogram (EMG) in 8 decerebrated dogs. Micturitions were induced by bladder filling and microelectrical stimulation of the pons before and after the administration of bunazosin. Bunazosin (0.03 mg/kg, i.v.) produced overflow incontinence in 7 of the 8 dogs and a significant decrease in the contractile response pressure to microelectrical stimulation of the pons in 6 dogs. Bunazosin appears to produce a decrease in urethral resistance and to be useful for the treatment of the failure of bladder emptying due to high urethral resistance.

Animals↗