Kinoshita Y

Genetic Regulation of the Development of Glomerular Sclerotic Lesions in the BUF/Mna Rat

BUF/Mna strain rats spontaneously develop renal glomerular sclerotic lesions (RSL) at a nearly 100% incidence, diagnosed by hyperalbuminuria (greater than 500 mg/dl) and glomerular lesions morphologically resembling one type of human focal glomerular sclerosis (FGS). Genetic segregation of RSL development was studied by crossing the BUF/Mna strain with two other rat strains, WKY/NCrj and ACI/NMs, which were free of RSL. Two autosomal recessive genes in the BUF/Mna rats were found to determine the susceptibility to RSL in both combinations of crosses.

Clinicopathological study of livers from brain-dead patients treated with a combination of vasopressin and epinephrine

Studies were made on the pathological lesions and biochemical indices of the livers of 22 patients in whom normal hemodynamics was maintained for 0-48 days after brain death by administration of vasopressin and epinephrine. Thirty-one specimens of liver tissues were obtained by percutaneous biopsy or at autopsy. The degrees of central venous congestion, central fibrosis, focal fibrosis, fatty metamorphosis, piecemeal necrosis, periportal fibrosis, and intrahepatic cholangitis in livers on various days after brain death were compared with those on the day of brain death (day 0). Central venous congestion was extensive on days 0-4, significantly less on days 5-14, and then again extensive on days 15-48. Central fibrosis and focal fibrosis showed no remarkable change during the 48-day period. Fatty metamorphosis, piecemeal necrosis, and periportal fibrosis showed no significant changes until day 16, but spread extensively on days 40-48. Intrahepatic cholangitis was scarcely observed on day 0 but began to increase after day 3, and spread extensively after day 5. The level of serum glutamic pyruvic transaminase did not increase in most patients until day 15. The mean value of prothrombin activity also did not decrease until day 15. However, the mean value of serum alkaline phosphatase increased gradually after day 3, and was correlated with cholangitis. The present study showed that during prolonged hemodynamic maintenance of brain-dead patients, pathological lesions did not spread or diminished and that biochemical indices did not become worse, or improved, in the first 2 weeks, except for increases in cholangitis and the serum alkaline phosphatase level.

Cytolytic effects of glucocorticoid on thymus-medullary lymphocytes incubated in vitro

Abstract Thymus cortical and medullary lymphocytes (TCL and TML) were incubated in vitro with or without cortisol. The cytolytic effects of the steroid on both thymocytes were examined in the microscope and by measurements of protein and RNA synthetic activities. There did not appear to be significant differences in the extent of damage by glucocorticoid exposure between both thymocytes, although the reduction of RNA synthesis in TML was less marked as compared with that in TCL. The facts that lymphocytes in thymus medulla were able to survive after cortisone injection and that the cells incubated in vitro were affected by the steroid presented the hypothesis that there might be some particular mechanisms in thymus medulla to protect lymphocytes from the cytolytic action of glucocorticoid.

The in vitro proliferation of thymus epithelial cells stimulated with growth hormone and insulin-like growth factor-I

The experimental system to scrutinize the in vitro proliferation of thymus epithelial cells (TECs) was established on the basis of enhancing their mitotic index and DNA synthetic activity. The TEC line, TAD3 derived from lymphocyte-dominant thymoma, was used as the cell material. Growth hormone (GH) induced a significant proliferation of the cultured cell line in the preconfluent state. The optimal concentration of and the duration of the incubation with GH, in this system, were 50 ng/ml and 18 hrs., respectively. Furthermore, insulin-like growth factor-I (IGF-I), the mediator of somatotropic action of GH, also enhanced the DNA synthetic activity of the cultured cells in the preconfluent state. The authors recently found that the TECs, stimulated with GH, released significantly more IGF-I than the cells without GH. It is possible that there are two systems in the TEC proliferation, namely, direct induction by GH itself and indirect induction by IGF-I released from the GH-stimulated TECs. The data showing that GH could directly or indirectly induce proliferation of TECs might possibly be related to the formation of epithelial thymic rudiment in the fetal stage.

Maturational impairment of thymic lymphocytes in streptozotocin-induced diabetes in rats.

Streptozotocin (STZ)-induced diabetes in rats was associated with marked decreases in thymus weight and the number of thymic lymphocytes. Histologically, the cortical lymphocytes which were present near the cortico-medullary junction in the thymus seemed to be reduced selectively in the STZ-induced diabetes. Rosette-forming cells, which bind to guinea pig erythrocytes in the presence of fetal calf serum, were also significantly decreased. Insulin treatment allayed these intrathymic changes. Preincubation of thymic lymphocytes from diabetic rats with thymosin fraction 5 significantly enhanced the percentage of rosette-forming cells to near the control level. These results suggest that a maturational impairment of thymus cortical lymphocytes may be caused in STZ-induced diabetes with hypoinsulinemia and it may be intimately related to reductions in thymus weight and the number of thymic lymphocytes.

Studies on Difference in Cellular Immune-Response Between the Human Tonsil and Blood Lymphocytes

Tonsillar and blood lymphocytes in a viable state were separated from tuberculin-sensitive tonsillectomized patients. The difference in the response to various cellular immunological stimulation between both lymphocyte groups was studied. Tonsillar lymphocytes without adherent cells could not respond well to PPD, while blood lymphocytes responded far better than tonsillar lymphocytes did to PPD when adherent cells were absent. PHA and PWM stimulated tonsillar and blood lymphocytes irrespective of the presence of adherent cells. However, in case of PWM stimulation, 3H-TdR incorporation was more remarkable in tonsillar lymphocytes than in blood lymphocytes. Furthermore, the lymphocytes which react to homologous cells also existed in the tonsils as in blood. These results suggest that there might be lymphocyte-subpopulations showing a difference of functional roles or of maturing-process between tonsil and blood lymphocytes.

Studies on the Capacity of Human Tonsillar Lymphocyte Subpopulations to Produce Interferon

Tonsillar lymphocytes produced classical interferon (Type I) in response to NDV infection and produced immune interferon (Type II) in response to PHA, PPD or histo-incompatible antigens. Lymphocytes having higher specific gravity and having a greater proliferative response to mitogens or antigens produced more interferon than lymphocytes having lower specific gravity. There was no difference between heavy and light small tonsillar lymphocytes in regard to their sensitivity to the protective effects of interferon. As for the interferon produced in association with a cellular immune response, the peak of interferon production tended to appear earlier than the peak of 3H-TdR incorporation. It is suggested that tonsillar lymphocytes play an important role in human host defense against virus infections.

Ouabain-like immunoreactive substances exist in the hypothalamus and the adrenal medulla in rats

Abstract Since it has been demonstrated that one of the endogenous digitalis-like factors (EDLF) is ouabain, searches for the EDLF are focused on the endogenous ouabain in the mammalian body. We have developed a monoclonal, anti-ouabain antibody which similarly cross-immunoreacts with other digitalis glycosides such as ouabain, digoxin, and digitoxin; the epitope of this antibody was confirmed to be the partial structure important for cardiac compounds and neutralizing their pharmacological activity, Na + /K + -ATPase inhibition, in a competitive mode against K + . By using this monoclonal antibody, we immunohistochemically examined the distribution of the digitalis-like substances in the adrenal glands and the hypothalamus. The immunoreactivity was diffusely distributed in the cytoplasm of endocrine cells of the adrenal medulla, but not in the adrenal cortex. Immunoreactive neuronal somata and their proximal processes were found in the hypothalamic paraventricular nucleus, and the intensity of the immunostaining in the proximal processes was greater than in the somata. In the neurons of the supraoptic nucleus very weak immunoreactivity was observed. No immunoreactive material was detected in the other areas of the hypothalamus examined in this study. Present findings with a monoclonal, ouabain antibody suggest that the ouabain-like immunoreactive substances are exclusively distributed in the neural tissues such as the hypothalamus and the adrenal medulla. Although the physiological role of the substance is still uncertain, this particular distribution suggests that it may be a neurotransmitter implicated in the cardiovascular and endocrine functions.

Separation of two antigenically different subpopulations of small lymphocytes from rat thymus

Abstract 1. 1. A group of small lymphocytes has been revealed to consist of heterogeneous cells in view of cellular specific gravity. On the basis of this information, three kinds of highly purified sub-populations of small lymphocytes were separated from rat thymus by combining a discontinuous density gradient centrifugation with absorbent-cotton column method. 2. 2. Heterologous antisera against these subpopulations were employed for scrutiny of surface antigenic properties of each subclass. The following three points were demonstrated; ( a ) The surface antigenicity of small lymphocytes (LSL) in the least dense fraction differed from that of the cell type (HSL) in the densest fraction; ( b ) the subpopulation obtained from the intermediate fraction appeared to be a mixed group which was composed of the cells having surface antigenic characteristics of LSL and of the cells possessing those of HSL; ( c ) it was presumed that small lymphocytes in rat thymus consisted of two subclasses with regard to their surface antigenic properties. 3. 3. An antiserum (AHSLAS) against the HSL subpopulation caused a selective depletion of lymphocytes in thymus-dependent areas of spleen and lymph nodes. A preabsorption of AHSLAS with the thymic HSL subclass resulted in the disappearance of its marked activity, but a previous absorption with the thymic LSL did not diminish the activity. These results suggested that some cells in the HSL subpopulation migrated from thymus into peripheral lymphoid organs.

Time-Dependent Fluorescence Depolarization of Fluorescein in Rat Thymus Lymphocytes

Time behavior of fluorescence depolarization has been measured for fluorescein molecules introduced into rat thymus lymphocytes by means of a time-correlated single-photon-counting method under the excitation by a CW mode-locked Ar + ion laser. The depolarization mechanism has been identified as restricted rotational Brownian motion of fluorescein in the case of very dilute dye concentration. The observed temperature dependence of rotatable angle of fluoresce in as well as that of rotational relaxation time is consistent with the expectation that the lymphocyte becomes softer as the temperature is raised. The relation between the quantities obtained by stationary and time-resolved experiments is discussed.