Association of Experimental Chronic Arthritis with the Persistence of Group A Streptococcal Cell Walls in the Articular Tissue

A single injection of isolated fragments of group A streptococcal cell walls into the joints of rabbits stimulated an initial acute reaction which was followed by a prolonged inflammatory process. The chronic process was characterized by hyperplasia of the synovial cells, diffuse infiltration of the villi by macrophages, and focal collections of lymphocytes in the stroma of the villi. These histological changes were similar to those seen in the early stages of rheumatoid arthritis. Antibodies specific for the mucopeptide and group-specific C polysaccharide antigens of group A streptococcal cell walls were labeled with either fluorescein or (125)I, and were used to demonstrate antigen in the synovial tissues. The antigens persisted within macro-phages for at least 5 weeks. Their presence correlated with the evolution of the chronic inflammatory process.     

Characteristics of the antigen-binding properties of lymphocytes in experimental Salmonella infection

The data on the count of antigen-binding lymphocytes in the blood and lymphoid organs of mice in the course of Salmonella infection are presented. The reaction used for their detection is specific. Antigen-binding lymphocytes detected in mice in Salmonella infection belong to T- and B-cell populations and carry surface receptors belonging to IgA and IgM. Study of antigen-binding lymphocytes 1-20 hours after infection may be helpful in the specific diagnosis of Salmonella infections.     

Primary stage of feline immunodeficiency virus infection: viral dissemination and cellular targets.

The objective of this study was to identify cellular and organ targets of acute feline immunodeficiency virus (FIV) infection in vivo. Tissues of FIV-infected cats were studied at eight time points during the first 3 months after experimental infection. FIV nucleic acids were first detected by in situ hybridization 21 days after infection, approximately 1.5 weeks after lymph node enlargement was first observed and 3 weeks before the primary acute flu-like illness. The majority of FIV-infected cells were present in lymphoid organs, though low numbers of infected cells were noted in nonlymphoid organs as well. Germinal centers harbored many of the FIV-infected cells within lymphoid tissues. The thymic cortex was also a major site of early infection. Combined in situ hybridization and immunohistochemistry revealed that T lymphocytes were the primary target of early FIV infection in tissues of cats before the onset of clinical signs of acute illness. An unidentified population of mononuclear cells and a few macrophages were also infected. During the ensuing acute flu-like illness, the proportion of FIV-infected macrophages in tissues increased dramatically. This early shift in the predominant cellular localization of FIV from T lymphocytes to macrophages may be important for establishing viral persistence.     

Perforin expression after acute myocardial infarction--a pilot study

Perforin is an important mediator of inflammatory reactions. It is a quick-action cytotoxic mediator accumulated in the cytoplasmic granules of effector immunity cells (T lymphocytes, NK and NKT cells) which provide death signal in infected or transformed cells. Perforin-positive cells were previously detected in myocardial tissue during Trypanosoma cruzi infection and viral myocarditis while its role in chronic and progressive cardiovascular inflammatory disease such as atherosclerosis is almost completely unexplored. The perforin activity is also untested during acute coronary events that represent unexpected atherosclerotic complications due to the inflammatory destabilisation and atherosclerotic plaque rupture. The aim of this study was to investigate the presence of perforin, an important immunological inflammatory molecule in peripheral blood lymphocytes during the early period after acute myocardial infarction. We analyzed three subject groups: women with ST-segment elevation acute myocardial infarction (STEMI) treated with primary percutaneous coronary intervention (PCI), conservatively treated women with acute myocardial infarction without ST-segment elevation (NSTEMI) and a control group of healthy volunteers. The STEMI and NSTEMI groups did not basically differ in medication neither in levels of routine laboratory tests, while troponin I were significantly higher in the STEMI group. In the study, we detected an early decrease of perforin-positive lymphocytes in STEMI patients that were in contrast with their persisting elevation among NSTEMI patients. Despite greater myocardial necrosis in the STEMI group, results of this pilot-study indicated the prolonged perforin-mediated inflammatory response in patients with NSTEMI. This perforin down-regulation that follows the coronary interventional reperfusion in STEMI emphasized the possible anti-inflammatory role of primary PCI among patients with acute myocardial infarction. Given that the issue of routine primary PCI in NSTEMI is nowadays highly topical, the results we expect in the wake of this pilot study could demonstrate a significant impact on clinical practice. Further research is needed to confirm these results, compare the perforin-mediated activity to other inflammatory mediators in acute coronary events and to examine their impact on the long-term outcome.     

Herpes Simplex Encephalitis: Two Fatal Cases

The clinical and pathological features of the first two reported cases of herpes simplex encephalitis occurring in Saskatchewan are presented. The clinical history of an acute onset, an early organic mental syndrome followed by coma, neurologic disturbances, rapid progression and death suggests the diagnosis. The acute, diffuse, inflammatory process with predominant involvement of the temporal lobes of the cerebral hemispheres and the presence of intranuclear inclusions in nerve and glial cells are illustrated. The viral particles were found in electron micrographs from the brain tissue of both patients. The definitive diagnosis was established by the isolation, from postmortem brain tissue, of the herpes simplex virus, which was grown in tissue culture and shown to be pathogenic in suckling mice.     

Analysis of immune response of guinea pigs infected with Brucella melitensis

The dynamics of the first antigen specific stage of immune response to Brucella infection was experimentally studied with the method of binding adsorbed antigenic immunoreagents with lymphocytes. The study revealed that the content of antigen-binding lymphocytes (ABL) reached its maximum as early as on day 7 after infection, gradually decreasing afterwards (but even on day 90 ABL could be detected in the blood). The specificity of ABL was proved by the fact that they were absent in noninfected animals, while in the animals infected with Brucella their content was higher than that of ABL specific to Yersinia enterocolitica O9; Brucella-specific ABL bound Brucella lipopolysaccharide (LPS) more intensively than Yersinia LPS. The detection of Brucella-specific ABL was inhibited by Brucella LPS more actively than by Yersinia LPS. The evaluation of the affinity of ABL to homologous LPS, made by the ratio of binding immunoreagents of the same specificity, but with suboptimal and optimal specificity, proved that an increase in the avidity of ABL occurred in the dynamics of the infectious process, which corresponded to the increase of their specificity.     

Inflammation may modulate IL-6 and C-reactive protein gene expression in the adipose tissue: the role of IL-6 cell membrane receptor

Only few studies have been addressed to the presence and regulation of C-reactive protein (CRP) gene expression in different districts of adipose tissue, and no study has investigated the role of adipose tissue in presence of inflammation. Therefore, the aim of this study was to investigate the inflammatory involvement of either adipose tissue or adipose cells (adipocytes and stromal cells, respectively) in patients with chronic inflammatory disease, focusing on regional adipose tissue CRP gene expression. Eighteen patients with inflammatory disease and 14 healthy controls were enrolled. All subjects underwent specific surgical procedures. Inflamed and noninflamed patients provided samples of subcutaneous and/or omental adipose tissue. All samples were analyzed by RT-PCR and real-time PCR for specific gene expression. In addition, both adipocytes and stromal cells were studied by real-time PCR and immunoprecipitation to evaluate either gene or protein expression of CRP. Our results (real-time PCR) demonstrated a higher gene expression of CRP, IL-6, and both IL-6 membrane receptors in subcutaneous samples of inflamed patients than in healthy controls. Furthermore, in omental fragments of inflamed patients, an enhanced mRNA abundance of the same genes, compared with subcutaneous, was observed. The results obtained at cellular level did not provide evidence of any difference between adipocytes and stromal cell CRP gene expression, whereas immunoprecipitation demonstrated the presence of CRP in inflamed subjects. These results provide first-time evidence of the involvement of adipose tissue in the course of chronic inflammatory diseases, with a different degree of participation of the different adipose tissue districts.     

Radiobiology of the acute radiation syndrome

Acute radiation syndrome or acute radiation sickness is classically subdivided into three subsyndromes: the hematopoietic, gastrointestinal and neurovascular syndrome but many other tissues can be damaged. The time course and severity of clinical signs and symptoms are a function of the overall body volume irradiated, the inhomogeneity of dose exposure, the particle type, the absorbed dose and the dose rate. Classical pathophysiology explain the failure of each of these organs and the timing of appearance of their signs and symptoms due to radiation-induced cytocidal effects of a great number of parenchymal cells of hierarchically organized tissues. Contemporaneously, many other radiation-induced effects has been described and all of them may lead to tissue injury with their corresponding signs and symptoms that can be expressed after short or long period of time. Radiation-induced multi-organ involvement is thought to be due to radiation-induced systemic inflammatory response mediated by released pro-inflammatory cytokines.     

Immunohistological studies with A1-3, a monoclonal antibody to activated human monocytes and macrophages

A wide variety of monoclonal antibodies (mAb) have now been produced which recognize cell surface antigens on human peripheral blood monocytes. However, few of these mAb demonstrate specificity for monocytes, and fewer still recognize antigens exclusively on monocytes activated by one or more stimuli and/or block specific monocyte functions. The mAb A1-3 binds to lipopolysaccharide (LPS)-stimulated monocytes but not to resting blood monocytes, and inhibits the procoagulant activity of these LPS-activated cells. By using this mAb, we examined the reactivity of monocytes/macrophages (MO) in a broad range of normal and inflammatory tissues by means of a sensitive, four-layer immunoperoxidase technique. Cells of the MO system, in addition to lymphocytes and dendritic cells resident in lymphoid tissues, liver, lung, and other organs, were nonreactive with the A1-3 mAb. In contrast, intense staining of inflammatory MO was found in biopsies from patients with renal allograft rejection, acute glomerulonephritis, or granulomatous diseases. This apparent restriction of A1-3 binding to inflammatory, "activated" MO suggests that A1-3 mAb will be useful for the analysis of MO "activation" in many pathologic processes.     

Differences in the inflammatory response induced by acute pancreatitis in different white adipose tissue sites in the rat

Background

There is increasing evidence of the role of adipose tissue on the systemic effects of acute pancreatitis. Patients with higher body mass index have increased risk of local and systemic complications and patients with android fat distribution and higher waist circumference are at greater risk for developing the severe form of the disease. Here we evaluated the changes on different areas of adipose tissue and its involvement on the inflammatory response in an experimental model of acute pancreatitis.

Methods

Pancreatitis was induced in male Wistar rats by intraductal administration of sodium taurocholate. Orlistat was administered to inhibit lipase activity. Activation of peritoneal macrophages was evaluated by measuring IL1β and TNFα expression. Inflammation was evaluated by measuring myeloperoxidase activity in mesenteric, epididymal and retroperitoneal areas of adipose tissue. Changes in the expression of inflammatory mediator in these areas of adipose tissue were also evaluated by RT-PCR.

Results

Pancreatitis induces the activation of peritoneal macrophages and a strong inflammatory response in mesenteric and epididymal sites of adipose tissue. By contrast, no changes were found in retroperitoneal adipose tissue. Inhibition of lipase prevented the activation of macrophages and the local inflammation in adipose tissue.

Conclusions

Our results confirm the involvement of adipose tissue on the progression of systemic inflammatory response during acute pancreatitis. However, there is a considerable diversity in different adipose tissue sites. These differences need to be taken into account in order to understand the progression from local pancreatic damage to systemic inflammation during acute pancreatitis.     

Activation of alveolar macrophages after plutonium oxide inhalation in rats: involvement in the early inflammatory response

Alveolar macrophages play an important role in the distribution, clearance and inflammatory reactions after particle inhalation, which may influence long-term events such as fibrosis and tumorigenesis. The objectives of the present study were to investigate the early inflammatory events after plutonium oxide inhalation in rats and involvement of alveolar macrophages. Lung changes were studied from 3 days to 3 months after inhalation of PuO2 of different isotopic compositions (70% or 97% 239Pu) and initial lung deposits (range 2.1 to 43.4 kBq/rat). Analyses of bronchoalveolar lavages showed early increases in the numbers of granulocytes, lymphocytes and multinucleated macrophages. The activation of macrophages was evaluated ex vivo by measurement of inflammatory mediator levels in culture supernatants. TNF-alpha and chemokine MCP-1, MIP-2 and CINC-1 production was elevated from 7 days after inhalation and remained so up to 3 months. In contrast, IL-1beta, IL-6 and IL-10 production was unchanged. At 6 weeks, pulmonary macrophage numbers and activation state were increased as observed from an immunohistochemistry study of lung sections with anti-ED1. Similarly, histological analyses of lung sections also showed evidence of inflammatory responses. In conclusion, our results indicate early inflammatory changes in the lungs of PuO2-contaminated animals and the involvement of macrophages in this process. A dose-effect relationship was observed between the amount of radionuclide inhaled or retained at the time of analysis and inflammatory mediator production by alveolar macrophages 14 days after exposure. For similar initial lung deposits, the inflammatory manifestation appears higher for 97% 239Pu than for 70% 239Pu.     

Mycoplasma pulmonis Arthritis in Congenitally Athymic (Nude) Mice

Histopathological examinations were performed on arthritic joints and other organs of strain BALB/cA nu/nu and nu/+ mice intravenously injected with Mycoplasma pulmonis strain m53. In both groups of mice suffering from polyarthritis, acute inflammatory lesions with infiltration of polymorphonuclear leukocytes in the synovia and periarticular tissues were observed one to two weeks after injection. In nu/nu mice, the acute inflammation appeared repeatedly up to 20 weeks after inoculation, when the experiment was terminated, and furthermore, extensive synovial and periarticular necrosis were characteristically present after the 4th week. Only a small number of lymphocytes and plasma cells were in the lesions. In nu/+ mice, after the early acute inflammation of arthritis, relapses of the infiltration of polymorphonuclear leukocytes were also observed in some mice in and after the 10th week. In addition, infiltration of lymphocytes and plasma cells was substantial after the 15th week. Focal necrosis was sometimes found in the liver of nu/nu mice. Perivascular infiltration of small lymphocytes and plasma cells was found in the lungs, liver and kidney of nu/+ mice in and after the 15th week. Repair mechanisms of injured articular tissues in nu/nu mice were histopathologically poor, while those in nu/+ mice seemed to be progressive and quite similar to those reported by many investigators for mice with the thymus intact. The histopathological differences are discussed in respect to the thymus-dependent immune responses.     

Apolipoprotein A-I infiltration in rheumatoid arthritis synovial tissue: a control mechanism of cytokine production?

The production of tumor necrosis factor α (TNF-α) and interleukin-1β (IL-1β) by monocytes is strongly induced by direct contact with stimulated T lymphocytes, and this mechanism may be critical in the pathogenesis of rheumatoid arthritis (RA). Apolipoprotein A-I (apoA-I) blocks contact-mediated activation of monocytes, causing inhibition of TNF-α and IL-1β production. This study examined the hypothesis that apoA-I may have a regulatory role at sites of macrophage activation by T lymphocytes in inflamed RA synovial tissue. Synovial tissue samples were obtained after arthroscopy from patients with early untreated RA or treated RA and from normal subjects. As determined by immunohistochemistry, apoA-I was consistently present in inflamed synovial tissue that contained infiltrating T cells and macrophages, but it was absent from noninflamed tissue samples obtained from treated patients and from normal subjects. ApoA-I staining was abundant in the perivascular areas and extended in a halo-like pattern to the surrounding cellular infiltrate. C-reactive protein and serum amyloid A were not detected in the same perivascular areas of inflamed tissues. The abundant presence of apoA-I in the perivascular cellular infiltrates of inflamed RA synovial tissue extends the observations in vitro that showed that apoA-I can modify contact-mediated macrophage production of TNF-α and IL-1β. ApoA-I was not present in synovium from patients in apparent remission, suggesting that it has a specific role during phases of disease activity. These findings support the suggestion that the biologic properties of apoA-I, about which knowledge is newly emerging, include anti-inflammatory activities and therefore have important implications for the treatment of chronic inflammatory diseases.     

Ultrastructure damage of oviduct telocytes in rat model of acute salpingitis

Acute salpingitis (AS) is an inflammatory disease which causes severe damage to a subset of classically described cells lining in oviduct wall and contributes to interstitial fibrosis and fertility problems. Telocytes (TCs), a newly discovered peculiar type of stromal cells, have been identified in many organs, including oviduct, with proposed multiple potential bio‐functions. However, with recent increasing reports regarding TCs alterations in disease‐affected tissues, there is still lack of evidence about TCs involvement in AS‐affected oviduct tissues and potential pathophysiological roles. We presently identified normal TCs by their characteristic ultrastructural features and immunophenotype. However, in AS‐affected oviduct tissues, TCs displayed multiple ultrastructural damage both in cellular body and prolongations, with obvious loss of TCs and development of tissue fibrosis. Furthermore, TCs lose their interstitial 3‐D network connected by homocellular or heterocellular junctions between TCs and adjacent cells. And especially, TCs connected to the activated immunocytes (mononuclear cells, eosinophils) and affected local immune state (repression or activation). Meanwhile, massive neutrophils infiltration and overproduced Inducible Nitric Oxide Synthase (iNOS), COX‐2, suggested mechanism of inflammatory‐induced TCs damage. Consequently, TCs damage might contribute to AS‐induced structural and reproductive functional abnormalities of oviduct, probably via: (i) substances, energy and functional insufficiency, presumably, e.g. TC‐specific genetic material profiles, ion channels, cytoskeletal elements, Tps dynamics, etc., (ii) impaired TCs‐mediated multicellular signalling, such as homeostasis/angiogenesis, tissue repair/regeneration, neurotransmission, (iii) derangement of 3‐D network and impaired mechanical support for TCs‐mediated multicellular signals within the stromal compartment, consequently induced interstitial fibrosis, (iv) involvement in local inflammatory process/ immunoregulation and possibly immune‐mediated early pregnancy failure.     

Induction of Experimental Chronic Arthritis in Rabbits by Cell-free Fragments of Erysipelothrix

A cell-free crude extract of Erysipelothrix rhusiopathiae injected by high pressure jet into the knee-joint of rabbits stimulated an acute, mild inflammatory reaction. Additional injections at 3-day intervals induced a chronic condition characterized by hyperplasia of the synovial cells and hypertrophy of the villi, due to infiltration by lymphocytes and plasma cells which formed aggregates resembling Allison-Ghormley bodies. There was also extensive proliferation of stroma vasculature and fibrous tissue. A similar jet injection of the diluent produced an early, transient, acute, and mild inflammation. A mechanism is postulated for fixation of one or more of the chemically characterized antigens in or near the synovium as a means of inducing the localized inflammatory response that predisposes the joint to infection.     

Distinct chemokine triggers and in vivo migratory paths of fluorescein dye-labeled T Lymphocytes in acutely simian immunodeficiency virus SIVmac251-infected and uninfected macaques

To define the possible impact of T-lymphocyte trafficking parameters on simian immunodeficiency virus (SIV) pathogenesis, we examined migratory profiles of carboxyfluorescein diacetate succinimidyl ester (CFSE)-labeled T lymphocytes in acutely SIVmac251-infected and uninfected macaques within 48 h after autologous transfer. Despite significant upregulation of homeostatic chemokine CCL19/macrophage inflammatory protein 3beta and proinflammatory chemokine CXCL9/monokine induced by gamma interferon in secondary lymphoid tissue in SIV infection, no differences in CFSE+ T-lymphocyte frequencies or cell compartmentalization in lymph nodes were identified between animal groups. By contrast, a higher frequency of CFSE+ T lymphocytes in the small intestine was detected in acute SIV infection. This result correlated with increased numbers of gut CD4 T lymphocytes expressing chemokine receptors CCR9, CCR7, and CXCR3 and high levels of their respective chemokine ligands in the small intestine. The changes in trafficking parameters in SIV-infected macaques occurred concomitantly with acute gut CD4 T-lymphocyte depletion. Here, we present the first in vivo T-lymphocyte trafficking study in SIV infection and a novel approach to delineate T-lymphocyte recruitment into tissues in the nonhuman primate animal model for AIDS. Such studies are likely to provide unique insights into T-lymphocyte sequestration in distinct tissue compartments and possible mechanisms of CD4 T-lymphocyte depletion and immune dysfunction in simian AIDS.     

Sex chromatin analysis of lymphocytes invading host organs in transfusion-associated graft-versus-host disease

We report a method of sex chromatin analysis of lymphocytes separated from host organs in transfusion-associated graft-versus-host disease (GVHD), which enabled the demonstration of invasion by donor lymphocytes. The lymphocytes examined were separated from deparaffinized tissue blocks of skin, spleen and bone marrow from two female patients with transfusion-associated GVHD by incubation in 0.5% pepsin. The tissues had been removed at autopsy and fixed in formalin. Sex chromatin analysis was performed by fluorescence microscopy on separated lymphocytes stained with 0.005% quinacrine dihydrochloride. By this means Y chromatin-positive (i.e. male) lymphocytes were demonstrated in the skin, spleen and bone marrow of both female patients.