The effects of FK506 and dexamethasone on rat thymocyte differentiation.

We investigated the effects of FK506 and glucocorticoids (GC) on rat thymocytes using flow cytofluorometry. Rats were treated with GC (0.1 mg/body, by single injection), with FK506 (1 mg/kg/day, for 7 days), or with FK506 and GC. GC alone significantly decreased the percentage of CD4+8+ thymocytes and increased the percentages of CD4-8-, CD4+8- and CD4-8+ thymocytes on day 7. FK decreased the percentage of CD4+8- and CD4-8+ thymocytes and increased the percentage of CD4+8+ thymocytes on days 5 to 14. FK and GC induced a significant decrease in the number of CD4+8+ thymocytes greater than that seen with GC alone on day 7. The absolute number of TCR alpha beta high MHC class Ihigh thymocytes after FK and GC was significantly lower than that of the control group, and was slightly lower than that after FK alone on day 14. These results suggest that combined treatment with FK506 and GC acts complexly to decrease rat CD4+8+ thymocytes and prevents thymocyte differentiation and maturation.

Analysis of cell surface antigens on glucocorticoid-treated rat thymocytes with monoclonal antibodies.

The effects of glucocorticoid (GC) on thymocytes have been utilized to investigate the maturation and differentiation of thymocytes, but these experiments have mainly been performed on mouse thymocytes. We investigated the cell surface antigens expressed by LEW rat thymocytes during thymic reconstitution after GC treatment. Three-color flow cytofluorometric analysis of CD4, CD8 and the T cell antigen receptor (TCR alpha beta) clearly demonstrated that normal rat thymocytes contain CD4-8+ TCR alpha beta- and CD4+8- TCR alpha beta- cells. After GC treatment, we observed significant increases in the percentages of CD4-8+ TCR alpha beta- and CD4+8- TCR alpha beta- cells. The extent of the increase in the percentage of CD4-8+ TCR alpha beta- cells was greater than that of CD4+8- TCR alpha beta- thymocytes. Two-color analysis of TCR alpha beta and major histocompatibility complex (MHC) class I antigen showed that GC treatment significantly increased the percentage of TCR alpha beta- MHC class Ihi cells. Three-color analysis of CD4, CD8 and MHC class I demonstrated that normal rat thymocytes contain CD4-8- MHC class Ihi cells, which increased in number after GC treatment. These results indicate that rat thymocytes contain no fewer CD4-8+ TCR alpha beta- and CD4+8- TCR alpha beta+ cells than do mouse thymocytes, and that CD4-8+ TCR alpha beta- cells predominate over CD4+8- TCR alpha beta- cells in LEW rat thymus. Rat CD4-8- cells seemed to be divided into two subsets of TCR alpha beta- MHC class Ihi and TCR alpha beta- MHC class I- cells.

Effects of FK506 on surface antigen expression by regenerating thymocytes after sublethal irradiation in the rat.

To determine the effects of FK506 on the intrathymic maturation of T cells, we analyzed changes in surface antigen expression by regenerating thymocytes after sublethal irradiation. Two-color flow cytofluorometric analysis of the regenerating thymocytes revealed that FK506 had few effects on the maturation of rat thymocytes from CD4-8- to CD4+8+, and from TCR alpha beta- MHC class I- to TCR alpha beta low MHC class I+ (TCR alpha beta, alpha and beta chains of the T cell antigen receptor). However, defects in the maturation of CD4+8+ cells to CD4+8- cells and of TCR alpha beta low MHC class I+ cells to TCR alpha beta high MHC class I+ cells were observed after FK506 administration. Furthermore, three-color analysis also detected a maturational defect of CD4-8+ TCR alpha beta high cells. Immunohistochemical analysis using MoAbs specific for MHC and TCR alpha beta revealed marked atrophy of the thymus medulla, suggesting disturbances in thymocyte regeneration and maturation. These results suggest that the maturation of CD4-8- TCR alpha beta- MHC class I- cells to CD4+8+ TCR alpha beta low MHC class I+ cells may be FK506 resistant, whereas FK506 may interfere with the maturation of CD4+8+ TCR alpha beta low MHC class I+ thymocytes not only to CD4+8- TCR alpha beta high MHC class I+ cells but also to CD4-8+ TCR alpha beta high MHC class I+ cells. We also demonstrated the possibility of enrichment of CD4-8- cells after sublethal irradiation and the existence of small subpopulations of CD4+8- TCR alpha beta- and CD4-8+ TCR alpha beta- cells which might mature to CD4+8+ cells in rat thymus.

[Multiorgan failure following intravesical bacillus Calmette-Guerin administration: a case report].

We describe a case of multiorgan failure after intravesical bacillus Carmette-Guern (BCG) immunotherapy for bladder cancer. A 58-year-old man with superficial transitional cell carcinoma of the bladder was initially treated by transurethral resection and intravenous chemotherapy, and then administered 11 sessions of BCG intravesically. He was administered BCG intravesically after cystoscopic examination. The next day he complained of nausea and malaise. He became hypotensive. The symptom progressed with multiorgan failure, disseminated intravascular coagulation and respiratory failure. The patient gradually improved with administration of antibiotics and corticosteroid, and hemodialysis, without antituberculous antibiotics. Intravesical instillation of BCG should not be carried out immediately after cystoscopic examination.

Effects of FK506 on rat thymic epithelial cells; immunohistochemical study.

The effects of FK506, a new immunosuppressive agent, on the rat thymus were investigated using the immunoperoxidase technique and flow cytofluorometry using monoclonal antibodies. Flow cytometric analysis of the thymus revealed that the proportion of cells labelled positively with OX7 (Thy-1 antigen), OX8 (CD8, T cytotoxic/suppressor cells) and W3/25 (CD4, T helper cells and macrophages) increased following treatment, with FK506, 1 mg/kg body weight for 14 days. A marked reduction of the thymic medulla following treatment was clearly demonstrated by staining with OX18 (MHC class I) and OX6 (MHC class II). Changes produced by FK506 were also observed in the cortical area of the thymus, being especially marked in the subcapsular area and around the blood vessels by staining with OX6, PKK-1 (alpha-cytokeratin), AB-1040 (type IV collagen), and AB-1220 (laminin). Eventually FK506 treatment resulted in patchy reduction of OX-6, PKK-1, AB-1040 and AB-1220 positive area in the cortex. This evidence suggests that FK506 may impair the thymic microenvironment and subsequently disturb the thymocyte maturation.

Effects of FK506 on rat thymus: time-course analysis by immunoperoxidase technique and flow cytofluorometry.

The effect of administration of FK506 at 1 mg/kg body weight for 14 days on rat lymphoid tissues, especially the thymus, and recovery after discontinuation of treatment, were investigated by the immunoperoxidase technique and flow cytofluorometry using monoclonal antibodies OX6, OX7, OX8, OX18 and W3/25, reactive with rat lymphocytes. Marked reduction of the thymic medulla upon treatment was clearly demonstrated by staining with OX18 and OX6. Changes produced by FK506 were also observed in the cortical area of the thymus, and were especially marked in the subcapsular area and around blood vessels. Eventually, the thymic cortex appeared patchy, this change being maximal 14 days after the start of administration. Obvious restitution of the thymic medulla was evident about 14 days after withdrawal of FK506. Flow cytometric analysis of the thymus showed that the percentages of cells labelled positively with OX7, OX8 and W3/25 were increased with FK506 treatment, and recovered to the normal level soon after withdrawal. Furthermore, the peak of fluorescence intensity of OX7+, OX8+ and W3/25+ cells showed a temporary shift to the right during FK506 treatment; however, the peak of fluorescence intensity of OX18+ cells showed a temporary shift to the left. Treatment with FK506 also produced a significant change in 3H-thymidine uptake by thymocyte. These results suggest that FK506 may inhibit the proliferation, maturation and differentiation of thymocytes. However, thymocytes prepared from FK506-treated rats and labelled with FITC behaved similarly to rat thymocytes in normal recipient rats. This suggests that during FK506 treatment thymocytes may retain their potential for peripheral mobilization.

Influence of nephrectomy on the growth of a murine Wilms tumor: a study using parabiotic rats.

It has been reported that unilateral nephrectomy causes acceleration of the growth of a Wistar/Furth rat Wilms tumor. We studied this phenomenon in parabiotic rats by measuring tumor growth after either sham nephrectomy, or excision of 1, 2 or 3 kidneys. We observed no stimulation of tumor growth in the experimental groups. Renal function was significantly decreased after removal of 2 or 3 kidneys. Serum creatinine levels were significantly different between right and left members of parabiotic pairs in these 2 groups. The effect of unilateral and bilateral nephrectomy on tumor growth in single rats also was examined. In these rats progressive increases in tumor growth were observed after unilateral and bilateral nephrectomy. Our inability to demonstrate a tumor-stimulating factor in the parabiotic model may be due partly to incomplete sharing of humoral factors between parabionts. Serum transfer studies in vitro may prove more fruitful in demonstrating such a factor.

Underexcretory-type hyperuricemia, disproportionate to the reduced glomerular filtration rate, in two boys with mild proteinuria.

Two unrelated boys with mild persistent proteinuria and underexcretory-type hyperuricemia of more than 9.0 mg/dl (535 mumols/l) are described. The proteinuria was detected at age 10 and 6 years, respectively. The fractional excretion of uric acid in both was low at 2-3%, when the creatinine clearance was decreased by about 50%. Tissue examination revealed focal interstitial fibrosis in both patients and medullary urate crystals in one patient in whom medullary tissue was obtained on biopsy. An immunofluorescence study was negative for immunoglobulins, complements and fibrin. Treatment of hyperuricemia did not prevent further deterioration of their renal function. One of them underwent a renal transplantation and then his serum uric acid level returned to the normal range. Neither patient had a family history of hyperuricemia, gout or inherited progressive renal disease. Both patients are likely to be sporadic cases of familial nephropathy with gout, an autosomal dominant disease, due to a new mutation. Hyperuricemia due to diminished uric acid clearance may be a risk factor or predictor for the development of progressive renal disease in some subjects.