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Query: UMLS:C0155339 (Brown)
 12,436 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A sequential analysis was made of various areas within the lymph nodes and spleen of newborn Brown Norway (BN) rats suffering from graft-versus-host disease (GVHD) subsequent to an allogeneic injection of adult Lewis (L) lymph node cells (experimental). One micron thick autoradiographs were compared between such experimental and control littermates having received the same number of syngeneic adult BN cells. Both experimental and control animals received tritiated deoxythymidine (3HdT) one hour before killing. The autoradiographs revealed a 2.25 and 2.50 times higher thymidine labeling index of lymphocytes in the deep cortex of mesenteric lymph nodes and white pulp of the spleen, respectively, for experimental animals. The experimental effect occurred within one day. The majority of the labeled cells in experimental animals were large lymphoblasts with prominent nucleoli. The labeling index within these areas remained significantly higher than control values until day 8 in the spleen and through day 14 within the lymph nodes. However, differences in labeled cells present in high powered microscopic fields reached a peak on day 3 within compartments in experimental animals but fell significantly below control values by day 9 owing to a pronounced disappearance of both small and large lymphocytes from these areas, and a decreased intensity of individual cell labeling as the reaction progressed. In contradistinction the concentration of labeled cells present in high powered microscopic fields of lymph nodes' medulla became 3.13 times controls by day 4. Most of these labeled cells contained a more basophilic cytoplasm than those found in the deep cortex and some were distinctly plasma cell precursors. In contrast to the deep cortex their concentration remained approximately three times control values until death. The data indicates that the major proliferative events within the spleen and lymph nodes in neonatal rat GVHD are initially restricted to donor cell localization areas of these tissue compartments. Subsequently the GVHD-related events may be attributed to other areas and possibly cell types. Thus any proliferation contributing to splenomegaly in the latter stages of GVHD appears to occur in the red pulp and that contributing to lymph node enlargement a medullary response.
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PMID:3H-deoxythymidine incorporation in graft-versus-host disease in the Norway rat. II. Autoradiographic studies. 1 7

Injection of mercuric chloride caused a progressive systemic lymphadenopathy and splenomegaly in Brown Norway (BN) but not in Lewis rats, as reported by others. We studied the number, duration and route of HgCl2 treatments and the topography of the resultant lymphadenopathy, as well as its age and strain dependency. Five injections of HgCl2 increased three-fold the weight of the lymph nodes which became considerably heavier than the spleen. Weanling rats were less susceptible than adults. A regional lymphadenopathy could not be produced. However, a synergistic interaction was observed when the systemic effects of HgCl2 were added to the regional lymphadenopathy produced by injections of metal powders, such that the lymph node mass approached 2% of body weight.
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PMID:The topography of mercurial lymphadenopathy in brown Norway rats. 326 61

Studies were conducted to compare the cell-mediated immune response of the Delayed Amelanotic (DAM) line of chickens with that of the line from which it originated, the Brown (BR) line, and a distantly related environmental control, the Light Brown Leghorn (LBL) line. Assays used to evaluate cell-mediated immunity were graft versus host (GvH) splenomegaly and the phytohemagglutinin (PHA) skin response. The three genetic stocks showed different responses to both tests with a variation in ranking between the tests. The GvH response of BR birds was significantly greater (P less than .01) than that of DAM birds, which was in turn significantly greater (P less than .001) than that of LBL birds. In the PHA skin test, the responses of BR and LBL birds did not differ but were significantly greater (P less than .001) than those of DAM line birds.
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PMID:Effect of selection for delayed amelanosis on immune response in chickens. 2. Cell-mediated immunity. 671 97

It is demonstrated in rats that, in the presence of early postoperative severe but transient uremia, the survival of first set Brown-Norway (BN) renal allografts in Lewis (LEW) recipients is at least three times prolonged when compared to non-uremic controls. This phenomenon is called "uremic escape of renal allograft rejection'. By means of lethal X-irradiation of donors of BN kidneys transplanted into transiently uremic and non-uremic LEW recipients, the presence of passenger lymphocyte immunocompetence is demonstrated to be obligatory for this phenomenon to occur. As a result of mobile passenger lymphocyte immunocompetence, a graft-versus-host (GVH) reaction is elicited in the spleens of LEW recipients of BN kidneys which amplifies the host response. The splenomegaly observed in LEW recipients of BN kidneys is caused not only by this GVH reaction, which is shown to be exquisitely sensitive to even mild uremia. It is also contributed to by a proliferative response of the host against the graft (which latter response is equated with an in vivo equivalent of a unilateral mixed lymphocyte reaction (MLR)), since the reduction in spleen weights caused by abrogation of mobile passenger lymphocyte immunocompetence brought about by lethal donor X-irradiation is increased significantly by early postoperative severe but transient uremia. It is concluded that in uremic escape of renal allograft rejection both reactions are suppressed by uremia during the early postoperative period. Prolonged survival is brought about, since on the one hand suppression of the splenic GVH reaction abolishes its amplifying effect on the host response, and on the other hand suppression of the splenic MLR equivalent interferes with the generation of cytotoxic T-lymphocytes and enhances the generation of suppressor cells.
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PMID:Uremic escape of renal allograft rejection. 702 51

The present studies were undertaken to evaluate the histologic effects of graft-versus-host disease on the host colon after small bowel transplantation. Graft-versus-host disease was produced in six Lewis x Brown Norway F1 rats by performing vascularized, out-of-continuity small bowel transplants from parental Lewis donors. Host proximal and distal colon were sampled 14 days after operation when signs of graft-versus-host disease, including weight loss and splenomegaly, were present. Tissue was assessed histologically by blinded observer and compared to eight sham-operated controls. Three histologic features were noted to be statistically increased in diseased animals: (1) mucin loss; (2) crypt abscesses; and (3) large lymphoid aggregates in the mucosa and submucosa. These features were more commonly noted in the distal rather than the proximal colon. Another group of five grafted animals treated with cyclosporine A (10 mg/kg/day intramuscularly) still lost weight but did not display overt signs of graft-versus-host disease and had normal-sized spleens. There was normal mucin content and no evidence of crypt abscesses in these treated animals, although large lymphoid aggregates were present. It is concluded that mucin loss, crypt abscesses, and large lymphoid aggregates are characteristics of graft-versus-host disease-induced colonic injury in this model and that these changes are most evident in the distal colon. Cyclosporine A therapy does not completely reverse the histological changes of colonic graft-versus-host disease. This model may be useful in studying the mechanisms by which immune mediated colitides preferentially affect the distal colon.
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PMID:Graft-versus-host disease after small bowel transplantation is associated with host colonic injury. 755 45

We have prevented graft-versus-host disease (GVHD) by tolerizing graft donors to host antigens by intrathymic injection of recipient-type splenocytes into donors. A unidirectional GVHD model was used in which intravenous injection of 3-4 x 10(8) Lewis rat (donor) lymphocytes into (Lewis x Brown Norway)F1 rats (recipients) causes lethal GVHD. The donor animals were divided into five treatment groups. The group 1 donor animals received no treatment. The group 2 donors received a single intraperitoneal injection of 1 ml of antilymphocyte antiserum (ALS). The group 3 donors received an intrathymic injection of 50x10(6) host splenocytes. The group 4 donors received both ALS (intraperitoneally) and intrathymic allograft. The group 5 donors received both ALS (intraperitoneally) and intravenous allograft. Two weeks after these treatments, 3-4x10(8) lymphocytes from each of these donors were injected (intravenously) into the recipients. The clinical signs of GVHD, as measured by profound weight loss, hair loss, inflammation of foot pads and ears, and profound splenomegaly, were evident in recipients of groups 1, 2, and 3 between days 9 and 10 and in the recipients (two of four) of group 5 on day 17. No GVHD was observed by histopathology in all 14 hosts that received lymphocyte injection from the group 4 donor animals (up to 300 days). These results demonstrate that GVHD can be eliminated by tolerizing donors toward host by intrathymic injection of the recipient-type lymphocytes into the donor. A single injection of ALS is necessary to possibly eliminate antihost response from the donor for the tolerance induction. The thymic route appears to be superior to the intravenous route for tolerance induction.
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PMID:Prevention of graft-versus-host disease by intrathymic injection of recipient-type splenocytes into donor. 893 89

Strain dependence of the induction of skin and lung lesions by hexachlorobenzene (HCB) in the rat was studied to further the insight into the etiology of the lesions. To this end, 3- to 4-week-old female Brown Norway (BN), Lewis, and Wistar rats received diets supplemented with 150 mg (BN and Lewis), 450 mg (BN, Lewis, and Wistar) or 900 mg (BN and Wistar) HCB per kilogram diet for 4 weeks. Gross skin lesion development during exposure as well as pathologic changes in skin and lungs and various parameters of immunomodulation after exposure were assessed. General toxicity as judged by a slight increase in body weight gain and induction of liver cell hypertrophy was similar in BN and Lewis rats exposed to 450 mg/kg HCB and in Wistar rats exposed to 900 mg/kg HCB. Skin lesions ranged from redness to large exudating sores with crusts. With regard to dose, time of onset, incidence, and severity, skin lesions were very severe in BN, moderate in Lewis, and negligible in Wistar. Porphyrins could not be detected in the skin, whereas porphyrins in the liver were seen only in Lewis rats. Histology showed epidermal hyperplasia, deep dermal venules with activated endothelium, and deep dermal inflammatory infiltrates mainly consisting of eosinophilic granulocytes in BN and of mononuclear cells in Lewis and Wistar. Nonlesional skin of HCB-exposed rats showed very similar, though less prominent, changes. Lung pathology appeared negligibly strain-dependent; histology showed venules with an activated endothelium surrounded by a perivascular infiltrate as well as focal alveolar macrophage accumulations in all strains. Parameters of immunomodulation showed moderate strain dependence; relative spleen weights were dose-dependently increased in BN and Wistar and in the 450 mg/kg group in Lewis rats. BN rats showed a more marked splenomegaly than the other strains. Relative popliteal lymph node weights were increased significantly in BN and Lewis rats exposed to 450 mg/kg HCB. In all strains, HCB increased lymph node HEVs. Serum IgE and IgG levels were increased significantly in a dose-dependent way in BN rats only. Total serum IgM levels were elevated significantly in BN, Lewis, and Wistar rats that received 450 mg/kg and in Wistar rats that received 900 mg/kg HCB. Serum IgM levels against ssDNA were dose-dependently increased in all strains, being more marked in BN and Lewis than in Wistar rats. It is concluded that the HCB-induced inflammatory skin and lung pathologies have different etiology. Pronounced strain differences in the skin lesions suggest a specific involvement of the immune system. Skin lesions correlated significantly with all assessed parameters of immunomodulation in BN, with some in Lewis and with none in Wistar rats. No correlation was observed between the parameters of immunomodulation and lung lesions.
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PMID:Hexachlorobenzene-induced immunomodulation and skin and lung lesions: a comparison between brown Norway, Lewis, and Wistar rats. 916 65

Brown hares (Lepus europaeus) trapped in the countryside and domestic rabbits were experimentally infected with Toxoplasma gondii (K7 strain) oocysts. Hares (n=12) were divided into groups of 4 and infected with 10, 10(3) and 10(5) oocysts. Rabbits (n=12) were infected in the same way. The experimentally infected animals were monitored for 33 days after infection (p.i.). Most of the infected hares demonstrated behavioural changes, and all of them died between 8 and 19 days p.i. Three of the rabbits demonstrated only clinical changes related to the concurrent pasteurellosis. The typical pathological finding in the hares were haemorrhagic enteritis, enlargement and hyperaemia of mesenteric lymph nodes, splenomegaly and multiple miliary necrotic lesions in the parenchyma of the liver and other organs. Pathological changes in the rabbits were less pronounced than in the hares. In rabbit brains, tissue cysts of the T. gondii were found. The incidence of T. gondii antibodies both in the hares and the rabbits was first ascertained on day 7 p.i. On day 12 p.i., antibodies were already found in all the animals infected. Antibody titres in indirect fluorescence antibody test (IFAT) using the anti-rabbit conjugate were markedly higher in rabbits than in hares. In all hares, T. gondii was isolated post mortem from the liver, brain, spleen, kidney, lung, heart and skeletal muscles. Although T. gondii was also isolated in all rabbits, it was not always isolated in all their organs. In all hares, parasitemia was demonstrated on days 7 and 12 p.i. The percentage of rabbits with detected parasitemia was lower. In hares, a decrease in the numbers of leukocytes during the infection was observed. No such decrease was observed in the rabbits. The lymphocyte activity after the stimulation with non-specific mitogens showed significant differences between the hares and the rabbits even before the infection. After the infection, the hares infected with 10(3) and 10(5) doses and in rabbits infected with a 10(5) dose showed a decrease of lymphocyte activity. Rabbits infected with a 10(3) dose showed an increase of the lymphocyte activity. While in hares toxoplasmosis was an acute and fatal disease, the infection in rabbits had subclinical manifestations only and easily passed to a latent stage. The different courses of toxoplasmosis in the hare and the rabbit may be due to the differences in the natural sensitivity of the two species to the T. gondii infection or a negative impact of stress to the immune status of hares.
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PMID:Fatal toxoplasmosis in brown hares (Lepus europaeus): possible reasons of their high susceptibility to the infection. 1102 57

Involvement of the mercapturic acid pathway in the induction of splenomegaly and skin and lung pathology by hexachlorobenzene (HCB) in the rat was investigated by seeking to determine whether pentachloronitrobenzene (PCNB) has the same inflammatory effects as HCB, since both compounds are directly conjugated to glutathione, and further processed into the same mercapturic acid metabolites which are excreted via the urine. Female Brown Norway (BN/SsNO1aHsd) rats at 3 to 4 weeks of age were orally exposed to diets with or without supplementation with 450 mg HCB or equimolar (467 mg) or higher (934 mg) amounts of PCNB per kilogram of diet over 4 weeks. Gross skin lesion development and body weight gains were assessed during exposure and spleen and liver weights as well as histopathologic changes in skin and lung were assessed after exposure. After 3 weeks of exposure, urinary metabolites of the mercapturic acid and oxidative biotransformation pathways were identified using high-performance liquid chromatography (HPLC) and liquid chromatography-mass spectrometry (LC-MS). Oral exposure of the rats to 450 mg/kg HCB resulted in an increase in relative spleen and liver weights as well as in the development of skin and lung pathology in the absence of overall liver toxicity. Equimolar or higher concentrations of PCNB caused none of these effects. Urinary levels of the mercapturic acid N-acetyl-S-(pentachlorophenyl)-cysteine (PCP-NAC), were comparable in HCB- and PCNB-treated rats. Levels of closely related methylsulfide derivatives of PCP-NAC, also generated via the same mercapturic acid pathway, appeared to be significantly higher in PCNB- than in HCB-treated rats, whereas the reverse was true for the urinary levels of the oxidative metabolite pentachlorophenol (PCP). Thus, results indicate that metabolites of the mercapturic acid pathway are not involved in the induction of splenomegaly and skin and lung pathology caused by HCB exposure in BN rats and that the main urinary metabolite of HCB in these BN rats is PCP. Since PCP itself, as well as other cytochrome P450-derived metabolites from HCB, are not likely to be involved in the induction of splenomegaly and skin and lung pathology, it is suggested that either the parent compound HCB or as-yet-unidentified non-P450-generated metabolites are involved in these inflammatory effects of HCB.
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PMID:The mercapturic acid biotransformation pathway of hexachlorobenzene is not involved in the induction of splenomegaly, or skin and lung lesions in the Brown Norway rat. 1120 68

Hexachlorobenzene (HCB) is a persistent environmental pollutant with (auto)immune effects in humans and rats. The Brown Norway (BN) rat is very susceptible to HCB-induced immunopathology, and oral exposure causes inflammatory skin and lung lesions, splenomegaly, lymph node (LN) enlargement, and increased serum levels of IgE and anti-ssDNA IgM. The role of T cells in HCB-induced immunopathology is unclear and to elucidate this Cyclosporin A (CsA) was used. BN rats were exposed to either a control diet or a diet supplemented with 450 mg/kg HCB for 21 days. CsA treatment started 2 days prior to HCB exposure and rats were injected daily with 20 mg/kg body weight CsA. Treatment with CsA prevented the HCB-induced immunopathology significantly. The onset of skin lesions was delayed and the severity was also strongly decreased. Furthermore, CsA prevented the HCB-induced increase in spleen weight partly and the increase in auricular LN weight completely. The increase in serum IgE and IgM against ssDNA levels was prevented completely. Macrophage infiltrations into the spleen and lung still occurred but infiltrations of eosinophilic granulocytes into the lung were prevented. Restimulation of spleen cells with the T-cell mitogen ConA and the macrophage activator LPS clearly showed that CsA inhibited T-cell activation, but not macrophage activation. Together, our results show that both T cells and macrophages play a prominent role in HCB-induced immunopathology.
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PMID:Hexachlorobenzene-induced Immunopathology in Brown Norway rats is partly mediated by T cells. 1530 97


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