Presence Of Inflammatory Cell Infiltrate Research Articles

A nonradioisotopic endpoint for measurement of lymph node cell proliferation in a murine allergic contact dermatitis model, using bromodeoxyuridine immunohistochemistry

Introduction: The murine local lymph node assay (LLNA) was developed as an alternative to guinea pig models for the assessment of the xenobiotic contact sensitization potential. However, it would be advantageous to have an alternative endpoint to the usual radioisotopic-dependent measures. In the present study, we investigated the development of a nonradioisotopic endpoint for LLNA using immunohistochemistry. Methods: Female Balb/c mice were treated by the topical application of strong sensitizers, 2,4-dinitrochlorobenzene (DNCB) and toluene diisocyanate (TDI), and a strong irritant, sodium lauryl sulfate (SLS), on the dorsum of both ears once daily for three consecutive days. The proliferation of cells in the auricular lymph node and ears was analyzed by means of the labeling index (LI) of bromodeoxyuridine (BrdU) incorporation into cells. Results: Skin reactions, consisting of increased ear thickness and the presence of inflammatory cell infiltrates, were observed in mice treated with DNCB and TDI. The cell number and the weight of the lymph nodes in the mice treated with the allergens, DNCB and TDI, were increased compared to vehicle control. We observed an increase in the areas of the B220 + cells in the lymph nodes of mice treated with allergens, as determined by immunohistochemistry. There was an increase in the percentage of B220 + cells in mice treated with DNCB and TDI compared to the vehicle control, but not in those treated with SLS. Because we observed an increase in the percentage of B cells in the allergen-treated group, we measured the stimulation index (SI) in the cortex and medulla (C+M) of the lymph node. The SI values of the C+M in the lymph nodes of the mice treated with DNCB and TDI were increased more than threefold compared with that of the control. However, the SI of the C+M in the lymph nodes of the mice exposed to 25% SLS was not significantly increased compared to the vehicle control, although the lymph node weight of the SLS group was significantly increased. Discussion: In Balb/c mice, BrdU immunohistochemistry showed its potential use for the identification and differentiation of chemicals with the capacity to induce irritation and sensitization. The results suggest that the measurement of the SI in the cortex and medulla of the lymph node using BrdU immunohistochemistry could provide a useful method to screen irritants and allergens.

Experimentally Induced Pyogenic Arthritis of Rabbit Knees: Comparative Study of MR Imaging and Pathology

Purpose: To compare the MR imaging findings of experimentally induced pyogenic arthritis of rabbit knees with the corresponding histopathologic findings. Materials and Methods: Infection was induced in 20 rabbit knees by direct intra-articular injection of Staphylococcus aureus. The animals were divided into four groups of five rabbits each, and spin-echo sagittal T1-and T2-weighted images were obtained 3 days, 1 week, 2 weeks, and 4 weeks, respectively, after staphylococcal inoculation. MR-pathologic correlation was performed, with emphasis on intra-and extra-articular soft tissue lesion characteristics. Soft tissue lesion signal intensity (SI) was classified as low, iso, or high on the basis of that of muscle, and high SI was further subdivided into three categories. Results: At T2-weighted imaging, all soft tissue lesions showed high SI. Pathologic examination revealed the presence of inflammatory cell infiltration (n=2), abscess (n=1), granulation tissue (n=3), fibrosis (n=11), edema (n=4), congestion (n=9), and joint fluid (n=11). Except for the abscess, these lesions were irregular in shape and had variable SI (grade 1-3) and at T2WI could not, therefore, be differentiated. In nine kness, extraarticular soft-tissue lesions were demonstrated at T2WI and correlated with infectious soft tissue lesions such as inflammatory cell infiltration, abscess, granulation tissues and fibrosis; and non-infectious reactive soft tissue changes such as edema and congestion. Conclusion: In pyogenic arthritis, the MR imaging features of soft tissue lesions varied and were nonspecific, depending on the histopathologic abnormalities observed. Our results indicate that in assessing the extent of pyogenic arthritis with MR imaging, caution is required.

Histopathology of resected myocardium and outcome of partial left ventriculectomy.

Since preoperative hemodynamics are not proven to be a predictor of effects of partial left ventriculectomy (PLV), myocardial histopathology may be better correlated with effects and outcome of PLV. Myocyte size (micron) in the excised myocardium was measured in 338 patients undergoing PLV. Endocardial fibrosis, interstitial fibrosis, and inflammatory cell infiltration were enumerated as none = 0, mild = 1, moderate = 2, and severe = 3. These histopathologic observations were correlated with patients' postoperative survival. Reduced survival was seen in patients with advanced (> or = moderate) interstitial fibrosis in all patients (n = 338, p = 0.064) and in the subgroup with nonischemic etiology (n = 229, p = 0.0039). Although correlation between endocardial and interstitial fibrosis was significant (r = 0.55, p < 0.01), endocardial fibrosis failed to correlate with postoperative survival. While Chagas' disease was associated with severe inflammation and poor survival, the presence of inflammatory cell infiltration had no effect on survival in all patients combined (p = 0.943). Although most patients (n = 266, 79%) had myocyte diameter over 30 micron, those with less hypertrophy (< 30 micron, n = 70, 21%) had a tendency toward increased survival (p = 0.067) regardless of underlying etiology. Interstitial fibrosis may be an important factor in stratification of patients for repair (PLV) or replacement (transplantation). PLV may be more beneficial in patients with less hypertrophy, before develqpment of interstitial fibrosis. Endomyocardial biopsy might not predict the extent or variation in degree of interstitial fibrosis, which may be better evaluated by other metabolic or perfusion studies that measure overall myocardial histopathology and viability.

Arterioplastia com enxerto de pericárdio bovino: estudo experimental em cães

Com o objetivo de avaliar a eficácia do pericárdio bovino (PB) para corrigir defeitos arteriais, provocado nas artérias femorais cão, foram realizados remendos de PB e veia cefálica autóloga (VA). Foram utilizados vinte cães, Canis familiaris (oito machos e doze fêmeas), divididos em dois grupos de dez animais (I e II), para serem reoperados no 7º e 30º dias de pós-operatório (PO), respectivamente. Para análise dos dados, aplicou-se o teste do qui-quadrado ou teste exato de Fisher (a£ 0,05). Nas avaliações clínicas não foram observadas alterações significantes, independentemente, do tipo de enxerto utilizado e tempo de observação PO. As avaliações histológicas, entre os enxertos de PB e VA, não diferiram significantemente quanto à presença de infiltrado inflamatório agudo e trombo mural, que predominaram no 7º PO, enquanto a presença de tecido de granulação, placa miofibroblástica e células endoteliais predominaram no 30º PO. A presença de necrose, no 7º PO, entre os enxertos de PB e VA, foi significantemente maior no PB. Os enxertos não sofreram calcificação. Ocorreu significante reação tipo corpo estranho ao fio de polipropileno, no 30º PO, em ambos os enxertos. O PB mostrou-se eficaz como substituto arterial em cães, comparável à VA, para o período de observação estabelecido.

Incidence and histologic characteristics of blebs in patients with abdominal aortic aneurysms.

Aortic blebs-focal outpouchings within aortic aneurysms-may contribute to their eventual rupture. In this study we determine the incidence of aortic blebs and describe their microscopic features. Computed tomographic scans of the abdominal aorta were obtained in 188 patients with aortic diameters measuring > or = 3 cm and were independently evaluated by a radiologist. The number and location of blebs were recorded, and each was measured with calipers. Sixteen blebs, with an adjacent uninvolved aneurysmal segment of aorta, and tissue from two patients with ruptured aneurysms were examined by light microscopy and immunohistochemical analysis. Specimens from six blebs and five aneurysms were examined for alpha 1 (I) procollagen messenger RNA by in situ hybridization. Twenty blebs, ranging in size from 5 to 30 mm (mean, 12 +/- 7 mm), were detected in 11% (20 of 188) of computed tomographic scans. Blebs were observed in 10% (11 of 111) of patients with aortic diameters between 3.0 and 4.9 cm, 10% (6 of 61) of patients with aneurysms between 5.0 and 6.9 cm, and 19% (3 of 16) of patients with aortic diameters > or = 7 cm. Histologically, the major difference between the aneurysmal aortic wall and blebs was found in the media. In aneurysmal aortas, the media consisted of multiple layers of fragmented elastic lamellae, whereas the number of elastic tissue elements along the circumference of the blebs progressively decreased; only a few isolated fragments of elastic tissue were present at the apices. Histologic evidence of rupture was evident in two specimens. A chronic inflammatory cell infiltrate composed of T and B lymphocytes, plasma cells, and macrophages, common to both the aneurysmal and the blebs, was most prominent in the adventitia of aneurysmal tissue, but involved both the media and adventitia of the blebs. In situ hybridization demonstrated the presence of alpha 1 (I) procollagen messenger RNA in four of the five aneurysm segments that were evaluated, compared with only one of six blebs. Blebs were discovered in aneurysms of all sizes; their frequency appeared to be unrelated to aneurysm size. The presence of inflammatory cell infiltrates and absence of alpha 1 (I) procollagen messenger RNA in five of six blebs suggest that a local imbalance of matrix degradation and repair plays a role in the cause of these lesions. Attenuation of the aortic wall accompanying the formation of blebs may predispose these sites to rupture.

Myocarditis and haemolytic uraemic syndrome.

A 13 year old girl is reported who presented with haemolytic uraemic syndrome (HUS) due to Escherichia coli O157:H7 infection. She died during the acute phase of the illness after an episode of unexplained sudden circulatory collapse. Postmortem examination confirmed the diagnosis of HUS and showed histological evidence of myocarditis manifested by the presence of inflammatory cell infiltration in the myocardium and around the conducting system.

Mechanisms of epithelial damage: are there parallels between bullous skin diseases and asthma?

Over the last few years evidence has accumulated documenting the incidence of basement membrane zone (BMZ) autoantibodies in blistering skin disorders such as bullous pemphigus [1], cicatricial pemphigoid [2], linear IgA disease of adults (LAD) and chronic bullous disease of childhood (CBDC) [3,4]. Regarding their underlying aetiology and histopathology, these conditions appear to bear some resemblance to asthma. For example, parallels which may be drawn between bullous skin disorders and asthma include epithelial shedding and the presence of inflammatory cell infiltrate, especially eosinophils.

Faulty Major Histocompatibility Complex Class II I-E Expression is Associated With Autoimmunity in Diverse Strains of Mice: Autoantibodies, Insulitis, and Sialadenitis

Many regions and loci of the murine genome contribute to the pancreatic and salivary gland autoimmunity observed in the diabetic NOD mouse. Examination of the major histocompatibility complex region of the NOD mouse has revealed a defect in the expression of the major histocompatibility complex class II gene, I-E. To determine the isolated role of faulty I-E expression in abnormal self-recognition, we examined six commonly used inbred strains of mice on diverse genetic backgrounds that also do not express I-E, i.e., C57BL/10, SJL, ACA, DBA/1, NOD, and 129. Autoimmunity was assessed by the presence of inflammatory cell infiltrates (0,+/-,+,++, , +) within and among the pancreatic islets and salivary glands, and autoantibodies to self determinants. At 6 mo of age, inflammatory infiltrates in the pancreas (0, 3 mice; +/-, 3 mice; +, 7 mice; ++, 6 mice; , 1 mouse; +, 5 mice) and/or salivary glands (0, 0 mice; +/-, 3 mice; +, 1 mouse; ++, 4 mice; , 6 mice; +, 10 mice) were detected as well as autoantibodies in all 24 mice of all I-E- mouse strains on diverse genetic backgrounds. This indicates that defective expression of this single locus, in isolation, is sufficient for the spontaneous development of autoreactivity. In contrast, the simultaneous examination of 19 I-E+ mice on five commonly used inbred strains of mice (BALB/c, C67/KsJ, B10.BR, B10.A [2R], and B10.A [5R]) demonstrated no signs of humoral or cellular autoimmunity with target gland destruction or lymphocytic invasion. Our data suggest that many commonly used inbred strains of mice represent models of autoimmunity attributable to this single defective gene.(ABSTRACT TRUNCATED AT 250 WORDS)

Pulp response to, and cariogenicity of, a further strain of Streptococcus mutans (NCTC 10832).

The pulpal response to and cariogenicity of a third strain of Streptococcus mutans, namely S. mutans (NCTC 10832), was studied in monoinfected gnotobiotic rats of the Fischer strain using the techniques described previously by the present authors. Unlike S. mutans (NCTC 10449 and 10919), S. mutans (NCTC 10832) was associated with the presence of inflammatory cell infiltrates in the coronal pulp of a small number of teeth and extensive periapical inflammation 28 days after the creation of untreated pulpal exposures. S. mutans (NCTC 10832) was associated with the presence of extensive pulpal necrosis and reduced dentine bridge formation. These changes were similar to those noted with the other two strains of S. mutans. S. mutans (NCTC 10832) was non-cariogenic in monoinfected gnotobiotic rats of the Fischer strain.

IMMUNOPATHOLOGICAL PATTERNS IN LONG-TERM RENAL ALLOGRAFTS

Forty-eight consecutive core needle biopsies obtained 12-158 months after transplantation from 48 human renal allografts were analyzed. A conventional histological investigation and an immunohistochemical analysis of various markers of the immune system were performed, as well as cytological analyses of simultaneously obtained fine-needle aspiration biopsies. Findings were compared in grafts with excellent or reduced function and in patients who were immunosuppressed with azathioprine or cyclosporine. All the patients with excellent renal graft function (serum creatinine level less than or equal to 120 mumol/L) showed a normal picture with respect to both FNAB pattern and immunohistology, irrespective of the type of immunosuppression. Thus, the presence of inflammatory cell infiltration in a long-term renal graft suggests a pathological process of potential clinical significance. Biopsies from CsA-treated patients with reduced renal graft function (serum creatinine greater than 120 mumol/L) showing either a normal picture or focal interstitial fibrosis on histological examination were also usually normal with respect to both FNAB cytology and the immunohistological pattern. Five of 36 biopsies with reduced function showed an immunohistochemical pattern with signs of immune activation indistinguishable from those seen in early acute rejection. In cases with histological signs of chronic rejection, the immunopathological pattern varied, which suggests that different pathogenetic mechanisms were involved.

Eosinophilic Fasciitis

Two patients with eosinophilic fasciitis were studied to elucidate the activation of collagen production in this disorder. Histologic examination of biopsy specimens from the involved area of skin revealed the presence of inflammatory cell infiltrates and various degrees of collagen accumulation in the dermis, subcutis, fascia, and underlying muscle. Fibroblast cultures initiated from the involved skin exhibited 2.0- to 3.7-fold increased collagen production when compared with control fibroblast cultures established from the uninvolved skin of the same patients. Eosinophilic fasciitis fibroblasts also displayed 2.4- to 6.2-fold higher steady-state levels of type I procollagen messenger RNA than did the control cells, indicating pretranslational activation of type I procollagen gene expression. In addition, cellular fibronectin messenger RNA steady-state levels were elevated 1.9- to 3.3-fold in eosinophilic fasciitis fibroblasts. These results suggest that fibroblasts in the involved skin of patients with eosinophilic fasciitis exhibit an activated phenotype, similar to that of scleroderma fibroblasts, leading to accumulation of collagen in the skin and the underlying structures.

Evaluation of the effect of Evan's blue and triphenyltetrazolium chloride dyes on myeloperoxidase activity in canine cardiac tissue

Myeloperoxidase (MPO) activity in postinfarction, dual-stained canine tissue in the presence of Evan's Blue (EB) and Triphenyltetrazolium chloride (TTC) was evaluated. Perfusion of EB and TTC allows quantification of the area of necrosis, area-at-risk of infarction and noninvolved, normal tissue postinfarction. EB in cardiac tissue has been reported to interfere with MPO activity used to measure polymorphonuclear leukocyte (PMN) infiltration, thus requiring that infarct size and MPO activity be measured in separate groups of animals. Admixtures of EB-or TTC-stained canine cardiac tissue extracts with MPO homogenates were found to have similar MPO activity. Addition of a constant amount of EB- or TTC-stained tissue to a standard curve of MPO activity failed to influence the concentration-activity relationship. Furthermore, EB in the presence of inflammatory cell infiltration in vivo in the mouse did not alter MPO activity. Thus, neither EB nor TTC signficantly interfered with the measurement of MPO activity so that EB and/or TTC-stained tissue can be utilized to examine the role of PMN's in myocardial infarction.

Rheumatoid nodules. A lightmicroscopical study with special reference to fibrin and fibronectin.

The presence and localization of fibrin and fibronectin in rheumatoid nodules were studied using an indirect immunoperoxidase technique on tissue specimens fixed in formaldehyde, embedded in paraffin and pretreated with pepsin and testicular hyaluronidase. Three zones characteristic for rheumatoid nodules was recognized. Central area with necrosis, containing at least in part fibrinogen-antigenic material and fibronectin especially in the peripheral part of the necrotic area. Around the necrosis a layer of mesenchymal cells in a palisade arrangement was found. Especially in the external part of this layer fibronectin was demonstrated around and between the cells, where fibrin was absent. Peripherally, a zone of non-specific granulation tissue containing moderate amount of fibronectin decreasing towards the surround mature connective tissue, was seen. In the border of the cellular layer vessels were found in variable amount. In some of the vessels vasculitis was demonstrated with the presence of inflammatory cell infiltration, fibrin deposition and occasionally thrombosis. The pathogenesis of the inflammatory reaction in rheumatoid nodules is discussed.