Relationship between the histological structures of spleen and its possible functions in the immune response

The spleens of human, ox, rabbits and rats were studied histologically. Serial sections of the tissues stained with methyl-green pyronin, Mallory-azan and Gridleys silver method were examined carefully in regarding to its architecture and staining nature of the composed cells. Pyronin-positive plasma cells were found to be localized at the periarteriallymphocyte sheath which surrounds the central arteries. The cells were more numerous at the terminal portion of the central arteries. Two distinct layers, the outer and the inner, were recognized and the apposed borders of each layer were separated by the reticular membrane which contains numerous marginal sinuses and capillaries. Composing cells of the marginal zone characterized by the small amount of pyroninophi1ic cytoplasm and lighter nucleus were different from the small lymphocytes and the macrophages. A nu ;nber of macrophages and rich capillaries were observed in the outer layer of the marginal zone. The so-called dark zone and the light zone of the g섬rminal center seemed to have constant direction of the arrangement, that is. the dark zone was located always near the central artery, while the light zone was far from the central artery. The possible invading route of the antigen in relation to the structures were discussed

Effects· of the Azathioprine Administered during Pregnancy on the Lymphoid Orga n s of the Neonatal Rats.

The following experiment was performed to study the effect of azathioprine administered during pregn' ancy on the development of lymphoid organs of neo' natal rats. The experimental animals were the three hundred Sprague·Dawley neonatal rats which were divided into four groups. The animals born from the azathioprine' administered adults during pregnancy were named for group 1 and 2. and were injected with antigen to group 1 and saline to group 2 respectively after birth. The animals of group 3 and 4 were born from the adults free of azathioprine during pregnancy and were injected with antigen to group 3 and saline to group 4 respectively after birth. Antigen or saline was injected intraperitoneally on the 1st. 4th. 9th. 12th and 16th week after birth. Then the spleen and thymus were resected on the 1st. 3rd. and 7th day after the injection for the plaque assay and histochemical studies The following results were obtained: 1. No plaque·forming cells and large pyroninophilic cells were observed in the spleens of all groups on the first week after birth 2. The number of plaque·forming cells and large pyroninoph i1ic cells observed in the spleens was much less after antigen injection but a little less after saline injection in the group of azathioprine admini stration than in the control group on the 4th. 8th and 12th week after birth. 3. A similar number of many plaque·forming cells and large pyroninophi1ic cells were observed in the all groups on the 16th week after birth. 4. While the development of thymus was retMded histologically for the groups of azathioprme acimini· stration than the control groups until the· 8th week after birth. a similar development of thymus between the two groups was observed on the 12th and 16h week after birth. 5. It may be suggested that adminislration of azathioprine did interfere with the development of T·lymphocyte and censequently affected the formation of antibody due to the insu뻐cient collaboration between T cells and B cells

Metabolism of C14-labeled Pyruvate and Glucose by Brain-Slices of Normal and Alloxan-Diabetic Rats.

Brain slices of 58 normal and alloxan-diabetic rats were divided into 4 groups. Each group was incubated for a period of 5 hours with incubation mixture consisting of 15 C.c. of phosphate buffer to which were added C1L glucose or C14-pyruvatc and 15 C.c of oxygen. During 5 hours of incubation period. the incubation media and gas phase were replaced with fresh media and oxygen at hourly intervals. This procedure made it possible to obtain hourly samples to determine the concentration of medium substrates and the amount and radioactivity of CO2 produced by the brain slices during the experimental period. It also had the advantage of presenting the tissue with a substrate of essentially constant concentration and specific activity. Data obtained from the C14-pyruvate incubation experiment, in the first and second group , and from the ClL glucose incubation experiment in the third and fourth group , were summarized as the follows. 1. In the ClL pyruvate incubation experiment, pyruvate disappearance rates were mean of 10.7 μM/hr/g in the first control group , and 12. 2 μM/hr/g in the second alloxan-diabetic group. The lactate accumulation rates in both groups were mean of 5. 8 and 5.1 μM/hr/g respectively. Total CO2 production rates in both groups were mean of 49. 7 and 63. 4 μM/hr/g respectively, showing a slightly higher value in the second group. However, since RSA, which represents the fraction of C14-02 derived from medium CILpyruvate to total CO2 production rate, was slightly hiher in the control group than the diabetic-group, there were little diffe• rences in C02 production rates derived from medium CILpyruvate of both groups. 2. In the C14-glucose incubation experiment, ClL glucose disappearance rates decreased about one half of the control in the diabetic group , showing a mean of 44.1 μM/hr/g in the third control group and 20.0 μM/hr/g in the fourth alloxan-diabetic group. Since there were not significant differences in total CO2 production rates and values in RSA, Cl4-0 2 production rates derived from medium clιglucose have been found to be almost the same value in both groups. From the data described above, insulin cannot have an influence on all the steps of carbohydrate metab olism in the brain tissue. However there is evidence that insulin exhibits the effect on membrane transport of glucose as found in the other tissues

Experimental Microvascular Grafts in Rats and Its Histological Studies.

Histopathological features of microvascular anasto! TIGses using "Invagination technique," end-to-end anastomoses and long term results of interposed venous grafts were studied in the femoral vessels of rat one to 12 months following surgery. The observation performed under light microscope, TEM and SEM. I. Histopathological features of the anastomotic site, which were repaired by "Invagination technique" and usual end·to·end anastomosis respectively, did not differ each other in the long term results. 2. Histological regeneration of anastomotic site did not accomplished by post·op 2 months and revealed active process was undergoing. 3. Endothelial lining of intima was nearly completed by 2 months at undamaged portion directly by suture materials. 4. In summary it may be said that histological examination of the specimen ranging in age from one to 12 months led general conclusion that venous grafts persist as living structure but undergo certain histological changes consisting of fibrous reinforcement

Production of Monoclonal Antibody for Vasopressin

Monoclonal antibodies were produced against arginine vasopressin (AVP) by fusion of mouse myeloma cells with hyperimmune mouse spleen cells. Modified radioimmunoassay(RIA) was used to detect the presence of specific antibody in culture. Specificity of the antibody was further characterized by enzyme linked immunospecific assay(ELISA). This antibody was able to localize differentially the vasopressin neuron from the oxytocin neuron in tissue sections of the hypothalamus

Histochemical Changes of the Rat Lymphatic Organs in Relation with the Altered Status of Thyroxin

To observe the effects of thyroxine on the lymphatic organs, the Sprague-Dawley rats weighing about 200g were classified into 4 groups (Group 1: control, Group 2: thyroidectomy, Group 3: tyroidectomy plus thyroxin treatment in the dose of restoring the metabolism to normal, Group 4: thyroxin treatment in the dose of inducing hyperthyroidism), and from each experimental animals thymus, lymph node and spleen were resected on the Ist, 3rd, 5th and 8th week and fixed in 10% neutral formalin after measuring the organ weight. Each sections were stained with Hematoxylin-Eosin, Methyl Green Pyronin, PAS and Silver stain and observed under the light microscopy. The results are summarized as follows. 1. Weights of the lymphatic organs per body weight decreased after thyroidectomy and increased after thyroxin treatment. 2. After thyroxin treatment: 1) Pyronin positive lymphocytes increased in the corticomedullary junction of thymus, germinal center of the lymph node and periarteriallympho cyte sheath of the spleen. 2) PAS positive cells increased in the corticomedullary junction of thymus. 3) Reticular fibers increased in the medulla of thy mus and perifollicular region of the lymph node. 4) Hematopoietic cells increased in the red pulp of spleen. 3. After thyroidectomy the density of chromatin in the nucleus of thymocytes decreased, and the lymphoid follicles decreased in size and number. 4. The results suggested that thyroxin acts as a mitogen and effects the proliferation and differentiation of lymphocytes

Study on the Inhibition of the Immune Response of the Neonatal Rat Spleen by the Azathioprine Administered during Pregnancy

The following experiment was performed to study the inhibition mechanism of the immune response in the neonatal rat spleen by azathioprine administered during pregnancy. The experimental animals were the two hundred neonatal rats which were born by sixty normal Sqrague- Dawley pregnant rats, of which 45 rats 8mgjkg of azathioprine were administered to orally at the 7th gestational day. Above two hundred experimental animals were divided into 6 groups as follows: Group 1: Neonatal rats to which T-dependent antigen, Sheep Red Blood Cells (SRBC) were injected intraperitoneally, born by normal pregnant rats. Group 2: Neonatal rats to which SRBC were injected intraperitoneally, born by pregnant rats to which azathioprine had already been given orally during pregnancy. Group 3: Neonatal rats to which SRBC were injected intraperitoneally and thymus cells derived from outbred neonatal rats were injected intravenously, born by pregnant rats to which azathioprine had already been given orally during pregnancy. Group 4: Neonatal rats to which T-independent antigen, Dextran was injected intraperitoneally, born by normal pregnant rats. Group 5: Neonatal rats to which Dextran was injected intraperitoneally, born by pregnant rats to which azathioprine had already been given orally during pregnancy. Group 6: Neonatal rats to which Dextran was injected intraperitoneally and thymus cells derived from outbrcd neonatal rats were injected intravenously, born by pregnant rats to which azathioprine had already been given orally during pregnancy. Antigen was injected intraperitoneally to above each group on the 1th, 8th and 12th weeks after birth and then, the spleen was resected on the 3rd and 7th days after injection of antigen for the plaque assay and histochemical studies. The following results were obtained: 1. Many plaque-forming cellsCPFC) were observed on the 3rd day after injection of antigen in all groups to which SRBC were injected, while many PFC were observed on the 7th day after injection of antigen in all groups to which Dextran was injected. 2. More PFC were observed in Group 1 than Group 2, and much more PFC were observed in Group 3. 3. There were no significant differences in number of PFC between Dextran·Groups(Group 4, Group 5 and Group 6). 4. There was strong tendency to recover the immunoIogicaI function with increasing age in SRBC· Groups(Group 1, Group 2 and Group 3). 5. Above results were in good accordance with those of histochemical observations. 6. It is strongly suggested that administration of azathioprine during pregnancy did suppress the development of fetal thymus, and that as a result of that suppression peripheral Tvhelper cells were depleted and consequently the formation of antibody was inhibited due to the insufficient colla' boration between T cells and B cells

Immunological and Histological Studies on the GALT and the Other Lymphoid Organs in the Rabbits

As an experiment for the study of bursa equivaleot organ in mammalia, the present experiment was performed on the GALT of young adult rabbits whether the cells of it respond to the antigenic stimulation or not. The experimental animals, weighed 1. 5 to 1.8kg, were randomly divided into two groups. Experimental group received a single injection of 1 ml of 20% sheep erythrocytes intravenously. Control group received a single injection of 1 ml of saline solut ion intravenously. After the injection of the antigen (or saline) the animals at various interval (from 1st day to 21st day) and the palatine tonsil, Peyer's patch, appendix, spleen , and thymus were removed. The cell suspensions obtained from each organ was used for the plaque technique and the paraffin sections obtained from each organ were carried out for the staining with methyl-green pyronin, silver, and hematoxylin-eosin. Hemolysin-producing cells were determined using a modification of Jerne plaque technique and the results were expressed as plaque-forming cells per 10' cells. The results were as followings: 1. In the experimental group the spleen and palatine tonsil produced a number of plaqueforming cells. It reached to the maximum at 3 days after the injection of the antigen and then decreased gradually. 2. By contrast, thymus, appendix, and PeyerS patch did not produce the plaque•forming cells as did the spleen and palatine tonsil. 3. The number of large pyroninophilic cells were markedly increased in the extrafollicular area of palatine tonsil and the periarteriallymphocyte sheath of spleen after the antigenic stimulation. It reached to the maximum at 3 days after the injection of antigen and then decreased gradually. 4. Number of large pyroninophilic cells did not change in the appendix, Peyers patch, and thymus after the antigenic stimulation. 5. The diffuse lymphatic tissue of the extrafolli cular area of palatine tonsil were more well developed than that of appendix and PeyerS patch. These results suggest that the palatine tonsil in the rabbits as well as spleen responds to the antigenic stirn ulation, while the appendix and Peyers patch do not

Studies on the Plasma Cells in the Lymphoid Organ during Pregnancy and Lactation in the Mouse I. Observations in the Thymus

The following experiment was performed to study on the numerical changes of the IgG, IgM and IgA bearing cells in the thymus during pregnancy and lactation in the mouse. The experimental animals were mated allogeneically (female ICRC x male DDY), and the thymi were resected at 4, 6 and 19 days of gestation and postpartum 20 days. The thymi were stained with MGP and immunohistochemical reaction. Then each group was compared with the virgin control group. The following results were obtained: 1. In 6 days of gestation, the number of IgA bearing cells was significantly more than that in virgin. 2. In 19 days of gestation, the number of IgG. IgM and IgA bearing cells was significantly more than that in virgin. 3. In suckling group, the number of IgG and IgA bearing cells was significantly more than that in virgin. 4. The immunoglobulin bearing cells were localized in perivascular region. On the basis of the above results, it is suggested that the thymus. the primary lymphoid organ, has relation with the maternal immune response, too

A Case of Anencephalus

A case of anencephalus. 38 weeks in fetal age. was observed. 1) The calvaria was completely absent and whole of the vertebrae showed complete spina bifida. There was strong lordosis between the 7th cervical and lst thoracic vertebra. which were compressed under the skull base. 2) Brain was completely absent while the bifurcated spinal cord was exposured on its upper half. Cranial nerves. of which peripheral part were existed. end in neighboring soft tissue or anastomosed with cervical nerves. 3) Marked enlargement or the liver was observed. 4) Absence of hypophysis and remarkable atrophy of the adrenal glands. characteristic features of the anencephalus. were observed in this case. 5) Profuse amount of amnionic fluid was detected in delivery.A case of anencephalus. 38 weeks in fetal age. was observed. 1) The calvaria was completely absent and whole of the vertebrae showed complete spina bifida. There was strong lordosis between the 7th cervical and lst thoracic vertebra. which were compressed under the skull base. 2) Brain was completely absent while the bifurcated spinal cord was exposured on its upper half. Cranial nerves. of which peripheral part were existed. end in neighboring soft tissue or anastomosed with cervical nerves. 3) Marked enlargement or the liver was observed. 4) Absence of hypophysis and remarkable atrophy of the adrenal glands. characteristic features of the anencephalus. were observed in this case. 5) Profuse amount of amnionic fluid was detected in delivery