首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 515 毫秒
1.
Four renal homotransplants were carried out between cadaver donors and four recipients, all of whom were in terminal chronic renal failure. Immune suppression was attempted with azathioprine (Imuran), actinomycin C and prednisone; no radiation was used, nor were the recipient''s kidneys, spleen or thymus removed. One patient died with disseminated histoplasmosis at two weeks; another with irreversible homograft rejection at 30 days; a third patient died of septicemia after 9½ weeks with stable renal function. The fourth patient, whose transplant had been ischemic for 190 minutes and had not functioned for 2½ weeks thereafter, eventually achieved good function which remained unchanged to 7½ months. Changes in urinary enzyme excretion and in the I131 renogram and meralluride scan were of value in assessing homograft rejection.  相似文献   

2.
The effects of neonatal thymectomy, at 3 days of age, on parameters of the reproductive axis were examined in male and female Sprague-Dawley rats. Gonadal and accessory sex tissue (male: epididymis, seminal vesicle, and ventral prostate; female: uterus) weights as well as anterior pituitary, spleen, and adrenal weights were determined in the thymectomized and sham-thymectomized animals at 20, 30, 40, 50, 60, and 90 days of age. Plasma gonadotropin concentrations as well as pituitary content of the gonadotropins and prolactin were assessed at each of these time intervals. No significant difference in gonad and accessory sex tissue weights was detected in thymectomized versus sham-operated controls at each of these times. Adrenal weights were increased in thymectomized animals compared with controls at 50 days of age and older in male rats and at 90 days in females. Spleen weights were decreased in the thymectomized males at 50 and 60 days of age. Thymectomy did not affect the spleen weight of females. Plasma concentrations of gonadotropins were unaffected in thymectomized males but were altered in females during the pre- and peripubertal period (Days 20-40). Vaginal opening, however, occurred at the same time in the thymectomized and control females. Pituitary gonadotropin and prolactin content were unaffected by thymectomy of the females, except at 90 days when pituitary luteinizing hormone (LH) content was lower in thymectomized than in control animals. LH and prolactin content were significantly reduced in the males at 60 and 90 days of age. These results demonstrate that there are sexual differences in the effects of thymectomy on parameters of the reproductive axis.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   

3.
Hypnosis was used to alter body image in an attempt to enable a woman to retain a skin homograft from an unrelated male donor. The man also acted as a nonhypnotized control by receiving a homograft from the hypnotized woman. Oneinch square full-thickness skin homografts were exchanged between the upper arms of the two volunteers. The homograft on the arm of the woman is still viable after eight months; the homograft on the man was rejected within two weeks. A second experiment in which the same subject was told under hypnosis to reject the homograft failed to produce rejection.Definite conclusions are not yet justified. Among factors to be considered in the present case are an unusual compatibility, schizophrenia as an inhibitor of the rejection mechanism, hypnotically induced irreversible acceptance, or other unknown mechanisms.  相似文献   

4.
AKR mice are highly susceptible to spontaneous T cell lymphomagenesis and thymus removal at the age of 1 to 3 mo greatly reduces its development. Twelve-mo-old AKR mice thymectomized at young age were shown previously to carry potential lymphoma cells that could be triggered to develop into B cell lymphomas (80 to 100%) after removal from their host "restrictive" environment into young histocompatible hosts. Additional attempts were made to terminate the potential lymphoma cell dormant state in 12-mo-old thymectomized AKR mice. Replenishment of some deficiencies caused by thymectomy at a young age, including a s.c. syngeneic thymus graft or a single injection of the dual tropic recombinant virus isolates DTV-71 or MCF-247 into 12-mo-old thymectomized AKR mice resulted in Ly-1+ pre-B or B cell lymphoma development in 80 to 98% of these treated mice. In vivo elimination of T cell subsets by administration of cyclosporin A or by mAb expressed on Th cells (anti-CD4) or cytotoxic T cells (anti-CD8) stimulated the progression of dormant potential lymphoma cells towards B cell lymphoma development. The most striking results were observed after administration of anti-CD8 mAb: 90 to 100% of these treated mice developed Ly-1+ B cell lymphomas within 80 days. The effect of rIL-2 on dormant PLC was also tested. Administration of rIL-2 to 12-mo-old thymectomized mice terminated tumor dormancy in 94% of the treated mice within 66 days. Tests of the resulting B lymphomas for dual tropic recombinant virus/mink cell focus-inducing virus infection indicated that the breakdown of tumor dormancy did not result from development of pathogenic class I mink cell focus-inducing viruses. These results suggest that T cell subsets and/or their products are involved in the proliferation arrest of potential lymphoma cells present in thymectomized AKR mice.  相似文献   

5.
The ontogeny of hemopoietic cells which contain the enzyme terminal deoxynucleotidyl transferase (TdT) was studied in rats and mice. During fetal life, TdT-positive cells were first detected in the thymus, where they appeared on or about day 17 of gestation. TdT-positive cells were not found in fetal liver, spleen, or bone marrow, but appeared in bone marrow and spleen on the day after birth. In the rat, peak levels of TdT-positive cells were attained at 3 to 4 weeks of age in thymus, bone marrow, and spleen, accounting for 67, 3.9, and 2.3% of nucleated cells, respectively. The percentages of TdT-positive cells in thymus and bone marrow decreased gradually thereafter, whereas, TdT-positive cells in spleen were no longer detectable by 7 weeks of age. Normal percentages of TdT-positive cells were found in bone marrow and spleen from neonatally thymectomized rats and congenitally athymic (nu/nu) mice. Dexamethasone treatment resulted in a marked decrease in TdT-positive cells. The results are discussed with respect to the putative role of TdT-positive hemopoietic cells as thymocyte progenitors.  相似文献   

6.
The influence of the thymus on the production of the macrophage migration inhibitory factor (MIF) was studied in C57BL and CBA mice thymectomized at 4--6 weeks of age. On the 1--21st day after the operation they were immunized intraperitoneally with complete Freund's adjuvant. MIF production stimulated by tuberculin was determined on the maximum of the immune response. MIF production was abolished in mice of both lines already during the first days. To elucidate a relationship between MIF production and the presence of the thymus the former was investigated in the thymectomized "nude" mice. The mice showed no MIF production. It was found as well that thymectomy can interrupt the immune response in early stages of its development and completely eliminates MIF production the first days after immunization. Moreover, thymectomy in adult mice also changes spontaneous migration of macrophages both in immunized and non-immunized mice. These changes were more pronounced in C57BL mice.  相似文献   

7.
Intact quokkas (Setonix brachyurus) were grafted with thymus and skin as neonates. Fifty seven percent of primary thymus grafts persisted when donors were less than 32 days of age, compared with only 20% when the dornors were juveniles. This suggested that neonatal tissue was more readily accepted than tissue from adult animals. When the recipients had left the pouch, induced tolerance was tested by grafting thymus and skin from the original donors. Second thymus grafts were generally unsuccessful; however, second skin grafts were accepted and remained intact over the three-year period of observation, provided that the hosts were less than about 40 days of age at the time the first graft were placed.  相似文献   

8.
Lymphopoiesis with respect to recirculating and non-recirculating small lymphocytes was measured simultaneously in rats thymectomized as adults. Removal of the thymus at four to five weeks of age had a profound inhibitory effect upon the production of recirculating cells, whereas the formation of non-recirculating lymphocytes was only slightly depressed. Thymectomy had approximately the same impact of lymphopoiesis as thymectomy and exposure of the animal to a large dose of whole body X- and γ-irradiation. The latter finding, and the failure of a thoracic duct cell transfusion to augment lymphocyte production, accord with the view that the thymus is the principle intermediate source of recirculating small lymphocytes in the normal, unstimulated animal.  相似文献   

9.
This paper examines the thymic dependence of alloimmunity inamphibians. In Xenopus, the presence of a thymus during thefirst 2 weeks of life is essential for the development of normalfirst-set skin allograft immunity. Thymectomy during this earlyperiod always impairs the alloimmune response of young adulttoads. However, most of these thymectomized animals are ableto completely destroy skin allografts, albeit with prolongedrejection times. Chronic graft rejection, rather than tolerance,still occurs following thymectomy as early as 5 days, when thethymus contains no small lymphocytes. In contrast to the considerabledifferences in first-set allograft survival times in controland early-thymectomized Xenopus, second-set grafts, appliedsubsequent to first-set destruction, are rejected in acute fashion(<3 weeks) in both groups. That the defect in first-set alloimmunityis specifically related to absence of thymus has been confirmedby implanting allogeneic thymus 2 weeks post-thymectomy. Thedonor thymus remains healthy and restores the allograft responseto normal. In contrast, allogeneic spleen does not reconstituteand itself often undergoes destruction. Preliminary autoradiographicexperiments on lymphoid tissue involvement in first-set allograftrejection are also described.  相似文献   

10.
Synopsis The ontogenetic development of the immune system in a marine teleostSebastiscus marmoratus was studied by histological examination and removal of the thymus. The pronephros and the spleen had been differentiated at the time of birth and contained small numbers of haemopoietic cells. In contrast to most vertebrates, the rudiments of the thymus were first visible 1 week post-birth in the dorsoposterior part of the pharynx, the same location as in the adults. However, small lymphocytes first appeared in the thymus of fish at 3 weeks of age, followed by the pronephros at 4 weeks and the spleen at 6 weeks. Complete or partial suppression of the antibody response to sheep red blood cells (SRBC) occurred in fish that were thymectomized at 1.5 months of age and immunized 2 weeks later, and a marked decrease in lymphocytes was observed in the pronephros and spleen. The thymectomy of adult fish also caused reduced serum antibody titres in fish immunized 1 month after the operation. These results suggest that the thymus plays an essential role in the development of the immune system and its functions continue into adult life.  相似文献   

11.
Experiments on rats have shown that thymectomy brings about the development of hypercoagulation and inhibition of fibrinolysis. Heterotransfusion is accompanied by hypocoagulation and stimulation of fibrinolysis in both intact and thymectomized rats. At the same time fibrinolysis in thymectomized rats is stimulated to a lesser degree than in intact animals. Preinjection into thymectomized rats of the thymus low-molecular factor thymaline over one week does not only make blood coagulation and fibrinolysis return to normal but also leads to adequate changes in the hemostatic system in response to heterotransfusion.  相似文献   

12.
Four weeks old (weanling) female rats were treated with the tricyclic antidepressant and histamine/serotonin receptor blocker mianserin for studying its faulty hormonal imprinting effect. Measurements were done four months later. Brain serotonin levels significantly decreased in four regions (hippocampus, hypothalamus, striatum and brainstem), without any change in the cortex. Sexual activity of the treated and control rats was similar. Cerebrospinal fluid nocistatin level was one magnitude higher in the treated rats, than in the controls. The density of uterine estrogen receptors was significantly reduced, while binding capacity of glucocorticoid receptors of liver and thymus remained at control level. The results call attention to the possibility of 1. a broad spectrum imprinting at the time of weaning by a receptor level acting non-hormone molecule 2. imprinting of the brain in a non-neonatal period of life and 3. a very durable (lifelong?) effect of the late imprinting with an antidepressant.  相似文献   

13.
The effect of chronic and acute treatment with DDAVP, a vasopressin analog, was studied in 2 month old male rats, using an active avoidance test in a shuttle box. The experiment lasted 6 weeks: an acquisition period of 4 weeks and an extinction period of 2 weeks. Rats were treated one hour before behavioral testing 3 times a week for 6 weeks with either DDAVP 20 micrograms/rat/day for the whole period (chronic group) or with DDAVP for the first week and again once only on the first day of the extinction period (acute group) or with saline. Chronic treatment with DDAVP resulted in better acquisition and in a marked retardation of extinction compared with the acute treatment group. These results were obtained both in normal rats and in rats pretreated at age 5 days of life with intracisternal 6-OH dopamine.  相似文献   

14.
White rats were thymectomized neonatally. After 60 days, no alteration was noted in the plasma or testis magnesium level. On the other hand, a marked decrease was observed in the magnesium content of muscle (-23%) and of bone (-19%). The injection of thymosin reversed these changes. These findings suggest that a correlation between the thymus and the muscle is exerted by a protein factor (thymosin), and that the thymus may act on sex glands through an indirect pathway.  相似文献   

15.
Male Wistar rats sustaining prefrontal cortex aspiration or sham operation at 6 days or 30 days of age were submitted to the following behavioural tests: open-field, acquisition and retention of two-way active as well as passive avoidance tasks. In the open-field the locomotor activity proved enhanced in all the aspirated animals and this enhancement lasted for 30 days. In the two-day active avoidance task, an acquisition deficit was observed in both aspirated groups; but when retrained one month later, they were able to acquire the avoidance task like sham-operated rats and no difference appeared between the groups aspirated at 6 or at 30 days of age. Concerning the passive avoidance task, no difference could be detected between aspirated and sham-operated animals of both groups except that the rats aspirated at an early age (6 days) seemed to display a better avoidance ability in the retention test. These behavioural alterations (hyperactivity and impairment of the acquisition of the 2-way active avoidance) resulted from the prefrontal cortex aspiration, at whatever age this aspiration was performed (6 days or 30 days). They disappeared after a postoperative recovery period of about one month, as evidenced by this longitudinal study.  相似文献   

16.
W Rino  D Teixeira 《Acta anatomica》1979,105(3):242-249
Differences in neurocranium growth at puberty were studied in rats of both sexes thymectomized and sham-thymectomized at 2, 4, 6, 8, 10, 12 and 14 days of age and in controls of matched age and sex; skull length, width and height, and skull base length and face length were measured. The neurocranium of the thymectomized rats was significantly smaller than that of the sham-thymectomized and control rats of both sexes and in all age-groups.  相似文献   

17.
In studies of the mouse thymus, lymphocyte mitoses are seen to be most frequent in the thymus cortex. There is evidence from thymic grafts that a hypothetical factor, thymopoietin, may stimulate mitosis of thymic lymphocytes. It is a factor which is postulated to act in conjunction with the PAS-positive mesenchymal reticular cells and epithelial reticular cells of the cortex. The thymus medulla is necessary for the integrity of thymic grafts, and may also elaborate a secretion for maintaining the cellular functions of the gland. Thymectomy has been used as a gauge for judging normal thymic function and results, in the mouse, in lymphopenia, degeneration of spleen and lymph nodes, delayed rejection of skin allografts, reduced ability of spleen cells to mount the graft versus host reaction, and reduced primary immune response to certain antigens. Correction of these deficiencies offers a means of evaluating various thymic extracts and grafts. Lymphocytosis-stimulating hormone (LSH) is known to maintain the peripheral lymphoid organs and cause lymphocytosis in the thymectomized animal. Diffusion chamber studies of thymic grafts also show restored lymphoid tissue by a cell-free factor (CIF). These two factors may be the same and probably represent the basis of the highly purified lymphocyte-stimulating proteins, LSHr and LSHh, which restore the L/P ratio in thymectomized animals and may stimulate lymphopoiesis in spleen and lymph nodes. LSHr, unlike LSHh, increases the total lymphocyte count. LSHr has been found to increase the humoral antibody response in neonatal mice both by the PFC technique and by direct hemolysis of sheep erythrocytes. Homeostatic thymic hormone (HTH) is a thymic extract of small molecular weight and contains nucleic acid. In the thymectomized guinea pig it has been found to maintain normal levels of lymphocytes in the blood, spleen and lymph nodes, to restore antibody titers to typhoid H antigen and to restore the toxic allergic reaction. Thymic humoral factor (THF) is of smaller molecular weight (less than 1,000) and probably is not a protein. It also enhances lymphoid proliferation in neonatally thymectomized mice. There is evidence that THF participates in humoral antibody formation because it stimulates PFC formation from neonatally thymectomized mice after inoculation with sheep erythrocytes. Its effects on cell-mediated immunity are seen from findings that injection of THF restores the ability of thymectomized mice to reject skin allografts. THF enables spleen cells from thymectomized or neonatal animals to mount the graft versus host reaction, and causes maturation of bone marrow cells and spleen or lymph node cells so that they can participate in the graft versus host reaction. It has been reported to stimulate lymphocytes to kill isogeneic tumor cells in vitro. Thymosin is protein extracted from the thymus. It has been found to alleviate leukopenia slightly and provide some improvement in lymphoid histology in thymectomized mice...  相似文献   

18.
Extirpation of the thymuses of Xenopus laevis abrogates the capacity to respond to trinitrophenol (TNP)-Ficoll regardless of the age of the animal. This thymus requirement can be substituted for by a variety of treatments which stimulate thymus-derived (T)cell activity in the periphery, such as the rejection of allogeneic skin grafts, immunologic challenge with thymus-dependent immunogens, (e.g., heterologous erythrocytes), or plant-derived lectins (e.g., concanavalin A). Here we report that interleukin 2 (IL-2), a T-cell-produced hormone of mammalian origin also substitutes for this thymus requirement in thymectomized toads.  相似文献   

19.
This study was designed to explore the role of short-course cyclosporin A therapy in preventing calcification. Homograft valves heterotopically allografted onto abdominal aorta from SD to Wistar rats. The expression of CD25, CD40L, CD71, calcium content and morphological change were observed. In control group, expression of immune indices got maximal at early stage postoperatively, and then gradually declined, remained at low level 12 weeks afterwards. In test group with Cyclosporin A, the expression of immune indices were lower than that of control group at 2–4 weeks postoperatively, but no significant difference was found 8 weeks afterwards. The calcification began from 4 weeks postoperatively, increased gradually and reached highest level at 12 weeks. In test group calcium content was much lower from 4 to 16 weeks postoperatively. It is concluded that cyclosporine A treatment can prevent calcification of homograft valves because it inhibited immune response at early stage after transplantation.  相似文献   

20.
Histocompatibility analyses in goldfish were performed using the tetraploid goldfish-crucian carp hybrid and the first generation of gynogenetic diploid (GD1) goldfish. Tetraploids were obtained by crossing clonal triploid crucian carp with goldfish. GD1 goldfish were produced by the suppression of the second meiotic division. Tetraploid scale grafts on triploid clone members evoked an acute rejection in 4–6 days, whereas the reverse transplants were accepted or rejected chronically. Reciprocal grafting between tetraploids showed subacute rejection in 10–12 days, although some fish showed chronic rejection in 20–30 days. On the other hand, scale grafts reciprocally exchanged among triploids were intact even 3 months after grafting, although some of them showed a unidirectional rejection pattern. Furthermore, allograft rejection among gynogens occurred between 5 and 20 days, whereas all the scale allografts between members of control siblings were rejected within 9 days. In addition, neither accelerated acute rejection nor acceptance of allografts was observed in grafts exchanged among GD1 goldfish. These results suggest that single doses of histocompatibility alleles are effective in eliciting acute rejection, and each of the fourth haploid set of chromosomes originating from paternal goldfish might share the same histocompatibility antigens to a large extent. This experiment also indicates that the genecentromere recombination rate is quite high with respect to the histocompatibility loci in this species.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号