Protective Effect of Biophytum sensitivum (L.) DC on Radiation-Induced Damage in Mice

The radioprotective effect of Biophytum sensitivum methanol extract was studied using in vivo mice model . Animals were exposed to whole body gamma irradiation (6 Gy/animal) after treatment with B. sensitivum (50mg/kg b.wt.) followed by estimation of cytosolic enzymes, level of antioxidants, hematological parameters, bone marrow cellular progenitors, serum cytokine levels and spleen hematopoietic colonies. Administration of B. sensitivum could reduce the enhanced level of ALP, GPT and LPO levels in irradiated animals. B. sensitivum could significantly enhance the glutathione (GSH) content in liver and intestinal mucosa of irradiated animals. B. sensitivum treatment could enhance the Total WBC count, cellularity of bone marrow, alpha-esterase positive cells, and relative organ weight of spleen as well as thymus. The number of hematopoietic colonies on the surface of the spleen was found to be enhanced after B. sensitivum treatment. B. sensitivum treatment could also stimulate the production of cytokines such as IL-1β, IFN-γ and GM-CSF in animals exposed to whole body gamma irradiation. The present investigation suggests that the protective effect of Biophytum sensitivum on Radiation-Induced hemopoietic damage is mediated through immunomodulation as well as sequential induction of IL-1β, GM-CSF and IFN-γ.     

Evaluation of the utility of popliteal lymph node examination in a cyclophosphamide model of immunotoxicity in the rat

The objective of this study was to characterize the variability of rat lymphoid organ weights and morphology following treatment with a known immunotoxicant, with a focus on the usefulness of evaluating popliteal lymph node weight and histology. Cyclophosphamide was administered to male Sprague-Dawley rats by oral gavage at doses of 2, 7 or 12?mg/kg/day for 10 consecutive days. Left and right popliteal lymph nodes (PLN), spleen and thymus were collected at necropsy, weighed, fixed and processed for histopathology. Femoral bone marrow was also collected, fixed and processed for histology. Organ weight variability was greater for PLN than for either spleen or thymus in control animals. There was a significant but weak correlation between paired left and right PLN weights (p?<?0.005; r²?=?0.2774). Significant treatment-related decreases in lymphoid organ weights were observed in spleen and thymus at?≥?7?mg/kg/day (p?<?0.01), whereas in PLN a significant decrease (p?<?0.05) was noted only at 12?mg/kg/day. The inclusion of PLN did not enhance the sensitivity of detection of systemic treatment-related changes in lymphoid organs in a rat cyclophosphamide model.     

The effect of hypophysectomy on the immune response

Twenty-one-day-old rats were hypophysectomized or sham-operated and challenged with sheep red blood cells 5 or 21 days after operation. Although the sizes of the bodies and lymphoid organs were greatly decreased in the hypophysectomized animals no significant difference was found in the numbers of plaque forming cells or serum antibody titres against the sheep red blood cells. The hypophysectomized rats showed a cell depletion in the perifollicular zone of the spleen follicles, but no obvious histological changes in the thymus.

It is concluded that pituitary hormones are not directly necessary for the formation of humoral antibodies.

     

Mechanisms of the antihypertensive effects of Nigella sativa oil in L-NAME-induced hypertensive rats

OBJECTIVESThis study was conducted to determine whether the blood pressure-lowering effect of Nigella sativa might be mediated by its effects on nitric oxide, angiotensin-converting enzyme, heme oxygenase and oxidative stress markers.METHODS:Twenty-four adult male Sprague-Dawley rats were divided equally into 4 groups. One group served as the control (group 1), whereas the other three groups (groups 2-4) were administered L-NAME (25 mg/kg, intraperitoneally). Groups 3 and 4 were given oral nicardipine daily at a dose of 3 mg/kg and Nigella sativa oil at a dose of 2.5 mg/kg for 8 weeks, respectively, concomitantly with L-NAME administration.RESULTSNigella sativa oil prevented the increase in systolic blood pressure in the L-NAME-treated rats. The blood pressure reduction was associated with a reduction in cardiac lipid peroxidation product, NADPH oxidase, angiotensin-converting enzyme activity and plasma nitric oxide, as well as with an increase in heme oxygenase-1 activity in the heart. The effects of Nigella sativa on blood pressure, lipid peroxidation product, nicotinamide adenine dinucleotide phosphate oxidase and angiotensin-converting enzyme were similar to those of nicardipine. In contrast, L-NAME had opposite effects on lipid peroxidation, angiotensin-converting enzyme and NO.CONCLUSION:The antihypertensive effect of Nigella sativa oil appears to be mediated by a reduction in cardiac oxidative stress and angiotensin-converting enzyme activity, an increase in cardiac heme oxygenase-1 activity and a prevention of plasma nitric oxide loss. Thus, Nigella sativa oil might be beneficial for controlling hypertension.     

Studies on the adsorbability of graft-versus-host-reactive lymphocytes

A certain proportion of normal lymphoid cells from organs of different anatomical origin can react against allogeneic histocompatibility antigens, e.g. they can mediate a graft-versus-host (GVH) reaction. The present study was undertaken in order to obtain information about the antigen-specific receptors on GVH-reactive lymphocytes. We used fibroblast monolayers as cellular immunoadsorbents.

The results showed that with the methods employed we could not adsorb specifically GVH-reactive lymphocytes in a reproducible way, irrespective of whether these cells were from normal lymphoid organs like spleen, lymph nodes, thymus and bone marrow, from artificial sources like thymus and spleen of anti-thymocyte antiserum treated mice or from spleens of semi-allogeneic, irradiated, thymocyte-reconstituted mice. The most pronounced effect of adsorption on fibroblast monolayers on normal lymphocytes was a non-specific enhancement of their GVH potential.

These findings are discussed on the basis of recent results showing both syner-gistic and antagonistic effects of T-lymphocyte subpopulations.

     

Modulation of B and T cell subsets in mice treated with fractionated total lymphoid irradiation. III. Spleen and thymus dependency of B cell maturation processes

The role of spleen and thymus in maturation processes of B cell subpopulations was examined using mice which underwent fractionated total lymphoid irradiation (TLI). (BALB/BL)F₁ mice received 200 rds lymphoid irradiation daily for 8 days. Mice were spleen-shielded or -unshielded, or thymus-shielded or -unshielded during the irradiation. One day after termination of the irradiation, TLI-treated unshielded mice were reconstituted with 10 × 10⁶ spleen, thymus or bone marrow cells of normal untreated syngeneic mice. Two and a half months after termination of the treatment, the ability of the treated mice to produce in vivo anti-trinitrophenyl (TNP)-Ficoll antibodies, and the capability of spleen cells of those mice to respond in vitro to dextran sulfate and lipopolysaccharide was checked. In parallel, stained spleen cells were analyzed on the fluorescence-activated cell sorter. The results indicate that B cell maturation occurs only in mice where the spleens were shielded during TLI-treatment or in TLI-treated mice reconstituted with spleen cells of normal untreated mice. In these mice, the light scatter and the fluorescence distribution profiles were the same as those obtained from spleen cells of control mice: the treated mice gave a high anti-TNP-Ficoll antibody response and the proliferative response of the cells was low to dextran sulfate and high to lipopolysaccharide. Thymus shielding during TLI treatment or reconstitution of TLI-treated mice with thymus or bone marrow cells could not abolish the blockage of B cell maturation processes. These findings indicate that the spleen plays an obligatory role in B cell subset maturation pathways, whereas the thymus appears to play no essential role in these processes.     

Migrant μ+δ+ and static μ+δ− B lymphocyte subsets

Immunoglobulin isotype expression in isolated lymph node (LN), spleen and blood lymphocyte suspensions was assessed in rats. The proportion of μ⁺δ^? B cells in spleen (34%) was approximately twice that in blood and LN. Immunohistological examination of spleens showed the cells of the marginal zones to be predominantly μ⁺δ^?. On the other hand, μ⁺δ⁺ B cells were mainly confined to the follicles in both spleen and LN. These follicles had a minor μ⁺δ^? component. The migratory properties of B cells with these two phenotypes were assessed by depleting lymphocytes migrating through the white pulp of rat spleen. This was achieved by placing a ³²P-impregnated β-emitting polythene strip over one half of the spleen. Examination of the nonirradiated half of the spleen, LN and peripheral blood after 12 days irradiation showed selective loss of δ⁺ B cells. The μ⁺δ^? cells of the splenic marginal zone were numerically unaltered. There was also a substantial residual μ⁺δ^? B cell presence in the small lymphocyte compartment of follicles of LN and spleen in depleted animals. In addition, the blood selectively retained a μ⁺δ^? B cell component. This was not derived from the spleen, as μ⁺δ^? blood B cell numbers were sustained even where both halves of the spleen were irradiated. It is concluded that: (a) the major static B cell component of spleen and LN is μ⁺δ^?, (b) that most if not all δ⁺ B cells repeatedly migrate through the spleen and (c) there is a blood-born μ⁺δ^? component which is resistant to depletion by splenic irradiation.     

Antigen in tissues: III. The separation of antigen-containing components from lymphoid tissues

Particulate and soluble antigens were labelled with ¹²⁵I, injected into rats and the lymphoid organs examined. As determined by autoradiography of tissue sections, one antigen used localized exclusively in vacuoles of medullary macrophages of the lymph nodes and others on the surfaces of reticular cells in the lymphoid follicles of nodes or the white pulp of spleen. The remaining antigens studied localized in both medulla and lymphoid follicles of nodes.

Tissues containing antigen were homogenized in a sucrose medium and most radioactivity was recovered in a large granule fraction. This fraction was submitted to equilibrium centrifugation. The preparations were not resolved in gradients of sucrose or dextran but in gradients of Urografin the preparations were resolved into two or more peaks of radioactivity. Medullary localized antigen banded in a region of the gradient rich in lysosomal enzymes and was considered to be present in vesicles. Antigen was not found in a region of the gradient rich in mitochondria. Antigen from lymphoid follicles of nodes or from spleen white pulp banded at high density values and was considered to be present as an antigen—antibody complex, possibly associated with membrane.

Equilibrium density centrifugation in Urografin gradients provides a means of separating and examining the properties of antigen in lymphoid tissues.

     

Organ specificity of antithymocyte globulin

Absorption of horse antimouse thymocyte globulin with either mouse kidney, liver, spleen, mesenteric lymph node, or bone marrow resulted in significant reduction of thymocytotoxicity titre. Absorption with thymus completely removed the thymocytotoxic effect. Cytotoxicity against spleen was removed by absorption with spleen, not by absorption with kidney, liver, or thymus.

Absorption by thymus resulted in complete removal of immunosuppressive potency, as judged by duration of survival of H-2 incompatible cardiac allografts, but absorption with the other lymphoid and non-lymphoid tissues did not significantly affect immunosuppressive potency.

These studies suggest that horse antimouse thymocyte globulin contained antibodies which were cross-reactive with non-thymic lymphocytes and non-lymphoid tissue but in addition contained antibodies specific for thymus. These thymus specific antibodies were of major importance in determining the immunosuppressive potency of horse antimouse thymocyte globulin.

     

Protective effect of Biophytum sensitivum (L.) DC on radiation-induced damage in mice

The radioprotective effect of Biophytum sensitivum methanol extract was studied using in vivo mice model . Animals were exposed to whole body gamma irradiation (6 Gy/animal) after treatment with B. sensitivum (50mg/kg b.wt.) followed by estimation of cytosolic enzymes, level of antioxidants, hematological parameters, bone marrow cellular progenitors, serum cytokine levels and spleen hematopoietic colonies. Administration of B. sensitivum could reduce the enhanced level of ALP, GPT and LPO levels in irradiated animals. B. sensitivum could significantly enhance the glutathione (GSH) content in liver and intestinal mucosa of irradiated animals. B. sensitivum treatment could enhance the Total WBC count, cellularity of bone marrow, alpha-esterase positive cells, and relative organ weight of spleen as well as thymus. The number of hematopoietic colonies on the surface of the spleen was found to be enhanced after B. sensitivum treatment. B. sensitivum treatment could also stimulate the production of cytokines such as IL-1beta, IFN-gamma and GM-CSF in animals exposed to whole body gamma irradiation. The present investigation suggests that the protective effect of Biophytum sensitivum on Radiation-Induced hemopoietic damage is mediated through immunomodulation as well as sequential induction of IL-1beta, GM-CSF and IFN-gamma.     

Identification by density separation of antigen-specific surface receptors on the progenitors of antibody-producing cells

Initiation of an immune response to sheep erythrocytes by the transplantation of spleen cells into irradiated recipients is thought to involve an interaction between two functionally different lymphoid cells. If such populations actually exist, it should be possible to separate them from each other and to study the properties of each type of cell. To this end, mouse spleen cells have been fractionated using equilibrium centrifugation in density gradients of Ficoll. Two functionally different populations of spleen cells were obtained. Neither population was active in initiating an immune response by itself on transplantation into irradiated mice, but mixtures of the two populations were. One population of spleen cells was also active when transplanted together with normal mouse bone marrow and the other population was active when mixed with thymus cells from normal mice. These results indicate that two different spleen cells must interact to initiate an immune response in vivo.

The specificity of the cell that synergizes with thymus cells was investigated further and shown to have antigen-specific receptors on its surface. These cells can be recognized by their ability to make rosettes with erythrocyte antigens. Thus, the `background' rosette-forming cells found in unimmunized mice are actually progenitors of antibody-producing cells.

     

Reduced sensitivity of F1 hybrid rats to rechallenge with parental strain spleen cells

1. F₁ hybrid rats that recovered from graft-versus-host (GVH) disease induced by the intraperitoneal injection of spleen cells of one parental strain showed varying degrees of resistance on re-challenge with cells of the same or of the other parental strain. Resistance to re-challenge, expressed either in terms of mortality or of severity of clinical manifestations, was greater after a strong than after a weak response to first challenge.

2. Resistance was shown not to be due to immunization of the F₁ hybrid. Resistant rats accepted skin grafts from both parental strains; resistance was not produced by the injection of thymic cells or of irradiated spleen cells; lethally irradiated thymectomized rats were able to develop resistance.

3. Two possible explanations of this phenomenon are discussed: (a) resistance is due to reactive hyperplasia of the recipient's lymphoid system; and (b) parental lymphoid tissue contains humoral antibody-producing cells: the iso-antibodies mask antigenic sites on the recipient's target tissues from the action of cells responsible for inducing a GVH reaction, by a mechanism analogous with that of tumour enhancement.

     

Contact and delayed hypersensitivity in the mouse: III. Depression of contact sensitivity by pre-treatment with antigen and the restoration of immune competence in tolerant mice by normal lymphoid and bone narrow cells

Contact sensitivity was produced in mice by applying an alcoholic solution of picryl chloride or 2-phenyl-4-ethoxymethylene oxazolone (oxazolone) to the abdominal wall. It was assessed by painting the ear with the contact sensitizing agent dissolved in olive oil and measuring the increase in ear thickness 24 hours later.

Contact sensitivity to picryl chloride was depressed by pre-treatment with the sulphonic acid derivative of picric acid. Complete depression was obtained when either two large doses or multiple small doses were given and in the former case this complete depression was still present 6 weeks after the last injection of the sulphonic acid. Similar pre-treatment with oxazolone depressed contact sensitivity to oxazolone in some but not all mice.

Pre-treatment with the folic acid antagonist amethopterin before and during sensitization almost completely abolished contact sensitivity, while a single larger dose given 48 hours before sensitization only had a small effect.

Mice whose immune response to picryl chloride had been depressed by pretreatment with sulphonic acid and methotrexate were used to study restoration of immune competence by normal lymphoid cells. No restoration was observed when unirradiated recipients were used. However, a mixture of lymph node and bone marrow cells and, to a lesser extent thymus and bone marrow cells, restored immune competence to picryl chloride in irradiated recipients. It was concluded that irradiation favoured the restoration of immune competence by normal lymphoid cells and that a mixture of lymph node and possibly thymus cells with bone marrow cells was able to cause restoration.

     

雌二醇对大鼠细胞免疫功能 的影响

本文采用大鼠去卵巢或再补充雌二醇(E_2)的方法探讨 E_(2)对免疫器官及其细胞免疫功能的影响。结果表明,去卵巢大鼠的脾脏和胸腺肥大,重量增加,脾细胞和胸腺细胞数明显增多。给去卵巢大鼠补充 E_2可使上述变化逆转。切除卵巢后的大鼠脾细胞对 ConA 诱导的增殖应答反应和诱生 IL—2的能力明显增高,补充 E_(2)亦可使上述变化逆转。但去卵巢大鼠的胸腺细胞对 ConA 诱导的增殖应答反应未能检测到可见的变化;给去卵巢鼠补充 E_2后,胸腺细胞对 ConA 的应答反应反而增强,并观察到胸腺细胞呈现轻度的自发增殖反应。实验结果表明:E_2能影响外周和中枢免疫器官及其细胞免疫功能,但这种影响在外周和中枢免疫器官表现出不同的变化。     

The immune response in lymphoid organs of rat: A cytochemical study

Variations in the activity of lactate dehydrogenase (LDH), succinate dehydrogenase (SDH), dihydrofolate reductase (DHFR) and alkaline phosphatase (ALP) were studied, using the light microscope (LM), and cytochemical reactions in lymphoid organs (lymph node, spleen, thymus) of rats, up to day 5 following Escherichia coli immunisation. Increased levels of LDH and DHFR in the T-area of lymph nodes and of spleen were seen from day 2 to day 4 postimmunisation. The SDH reaction in lymph nodes and in the spleen increased during days 2 and 3 but decreased on day 4 postimmunisation. Considerable increases in the activities of LDH and SDH were seen in thymus at all times postimmunisation. The DHFR reaction product also increased but less markedly. No reaction for ALP was observed in lymphocytes of lymphoid organs studied. Following E. coli immunisation, there is an increase in glycolytic and respiratory metabolism, and in the synthesis of proteins in T-dependent areas of lymphoid organs. These increases are correlated with immune activation of T-cells in these organs.     

The development of lymphocytes with T- or B-membrane determinants in the human foetus

The development of T- or B-membrane determinants on human foetal lymphoid cells was studied by the direct immunofluorescence technique, using a tetramethyl rhodamine isothiocyanate (TRITC) labelled horse antihuman T-cell conjugate (ATC) for the detection of T lymphocytes and a fluorescein isothiocyanate (FITC) labelled goat antihuman Fab conjugate for the demonstration of Ig-bearing B lymphocytes. Human foetal lymphocytes were also tested for spontaneous rosette formation with sheep red blood cells (SRBC).

Cell suspensions of liver, spleen, thymus, bone marrow and blood of twenty-five human foetuses of 5·5–26 weeks of gestational age have been investigated. ATC-positive lymphoid cells were first seen in the liver at 5·5 weeks; E rosette-forming cells (ERFC) and Ig-bearing lymphoid cells were first found at 9 weeks. ERFC were also present in the thymus at 9 weeks. By 12 weeks, fluorescent B and T lymphocytes were found in bone marrow and spleen. ERFC were also found in bone marrow at this age, but not in spleen. At 15 weeks, more than 80% of blood lymphoid cells had T or B determinants.

A difference in the reactivity of lymphoid cells with the ATC and their capacity to form E rosettes was observed. In liver and spleen, the ATC determinant was detectable before the SRBC receptor. In bone marrow, blood and thymus the ATC determinant was found on a higher percentage of lymphoid cells than was the SRBC receptor when those organs were first investigated. During the entire investigated period of gestation, the majority of lymphoid cells in liver and bone marrow did not react with either of the conjugates, nor did they form E rosettes. In all organs investigated, except in the thymus, lymphoid cells were occasionally seen which reacted with both conjugates. By the 16th week of foetal age, more than 90% of lymphoid cells in thymus, spleen and blood had acquired T- or B-membrane determinants.

     

The prevalence of human thymic lymphoid follicles is lower in suicides

In an autopsy study we determined the prevalence of thymic lymphoid follicles in 311 accident victims in whom the time interval between accident and death was known. We found that the prevalence decreased abruptly in those surviving 48 h or more (P=0.000008). We then compared the prevalence in 271 accident and 168 suicide victims, all of whom had died less than 48 h after the incident and found that the prevalence was significantly lower in the suicide group (P=0.03). We conclude that this difference may be related to the effect on the thymus of high levels of psychological stress likely to have been experienced by the suicides in the days prior to the act. The use of the term hyperplasia to indicate the presence of lymphoid follicles in the thymus and the methodology appropriate for determining the prevalence of thymic lymphoid follicles are discussed. Received: 9 February 1999 / Accepted: 26 August 1999     

Toxic effects of mercuric sulfide on immune organs in mice

Mercuric sulfide (HgS) is a major component of cinnabar, which has been used as a sedative drug in China for more than 2000 years. Because its toxicological effects are still unclear, we attempted to verify the toxic effects of HgS, focused on liver and immune organs such as the spleen and thymus. Male ICR mice were administered HgS (0.02, 0.2, 2.0?g/kg/day) by gavage for 4 weeks. During the administration period, HgS-treated mice did not reveal overt signs of clinical toxicity. HgS had no significant effect on body weight, food consumption, water consumption, and organ weights. In spite of its known insolubility, HgS was absorbed by the gastrointestinal tract and accumulated in the liver, spleen and thymus in a dose-dependent manner. In the biochemical and histological examination, HgS did not cause hepatotoxicity. However, HgS significantly increased both CD8⁺ T lymphocytes and CD4⁺CD8⁺ lymphocyte populations in the spleen without changing in the thymus. In the histological evaluation, HgS induced enlargement with marked hyperplasia and increase of lymphoid follicles in the spleen. In addition, HgS induced the gene expression of pro-inflammatory cytokines in the spleen and thymus. Our results suggest that insoluble HgS was absorbed by the gastrointestinal tract, accumulated in the spleen and thymus, and thus could affect immune systems.     

Treatment of radiation disease by Nocardia fraction: Possible effect of inflammatory cytokines

Nocardia delipidated cell mitogen (NDCM) derived from Nocardia opaca, given 2 h after wholebody gamma irradiation (2.5 Gy) to germ-free piglets in amounts of 1 mg/kg via a stomach tube, prevented the loss of B-cells in the spleen, intestinal mucosa, and mesenteric lymph nodes when recorded on day 8 after irradiation. NDCM and/or formolized Enterococcus faecalis strain (Ef) applied intrapertioneally also 2 h after irradiation increased the survival rate in mice irradiated with 8.3 Gy and 8.5 Gy doses. The number of nucleated bone marrow cells and the content of RNA in the spleen were significantly higher in rats given immunostimulators NDCM and Ef after irradiation with 5.0 Gy. The effect is presumed to be a consequence of stimulated production of inflammatory cytokines.     

Changes produced by pertussis antigen on the blood cells and lympho-haemapoietic tissues after early and late thymectomy or splenectomy

The effect of thymectomy and splenectomy in C3H/Bi mice on the responses of circulating leucocytes and on morphological changes of the haematopoietic tissues after injection of pertussis vaccine has been studied.

After pertussis all mice showed depletion of lymphoid cells in all the lymphoid organs as well as in bone-marrow and an increased number of leucocytes, lymphocytes, neutrophils and monocytes in the circulation. Neonatal thymectomy decreased lymphocytosis produced by pertussis. Thymectomy, at all ages studied, fostered an increase in the number of monocytes and polymorphonuclears in circulation. Splenectomy at birth or early in life provoked an increase in levels of circulating polymorphonuclears and lymphocytes in pertussis treated animals.

In neonatally thymectomized mice the depletion of lymphoid cells from lymphoid tissues after pertussis could be shown to include the thymic-independent areas. The depletion of small lymphocytes from thymus following pertussis persisted longer than depletion of small lymphocytes from spleen, marrow or lymph nodes. The longer persistence of lymphoid depletion in the thymus than in peripheral lymphoid tissues is, we believe, to be related to the central lymphoid function of thymus as a site of differentiation of lymphoid cells and to the aloofness of thymus from recirculation of fully differentiated peripheral lymphocytes.