Inflammatory Neutrophil Infiltration Research Articles

Acute Bullous Hemorrhagic Pyoderma Gangrenosum: Pitfalls of Diagnostic Delay

Pyoderma gangrenosum is an uncommon inflammatory skin disease causing progressive, painful cutaneous ulceration. Systemic disorders are associated with approximately 50% of the cases; the most common disorders are inflammatory bowel disease, rheumatoid arthritis and the seronegative arthritides, hematological malignancies, and monoclonal gammopathies, most typically IgA. The bullous variant is often associated with myeloproliferative diseases1,2. Histologically, pyoderma gangrenosum is classified among the neutrophilic dermatoses, a group of cutaneous disorders characterized by a widespread, noninfectious, dermal neutrophilic inflammatory infiltrate. The histologic findings are variable and depend on the age of the lesion and the location of the biopsy. Although the histopathologic features are not diagnostic, a skin biopsy is necessary to rule out other causes of acute skin ulceration. The location of the biopsy is crucial in order to distinguish the lesion from other conditions, including the other neutrophilic dermatoses, infections, and vasculitis. The most fruitful yield comes from the violaceous edge of the lesion, rather than the center of the ulcer, which may show nonspecific secondary changes. A deep wedge biopsy including both the edge and a more central portion of the ulcer is most useful, and special stains for bacteria, mycobacteria, and fungi should be performed. Because the histologic features of pyoderma gangrenosum are nonspecific, the diagnosis is truly one of exclusion and is heavily reliant on clinical features and course. The absence of diagnostic laboratory tests or pathognomonic features and the fact that associated conditions may be undeclared put the onus on the treating physician to exclude other causes of skin ulceration and to identify any underlying disease. In one recent study, the frequency of misdiagnosis of pyoderma gangrenosum was 10%3. The condition most often presents on the legs as a rapidly expanding solitary ulcer with a violaceous, undermined border and a necrotic …

Pancreatic Panniculitis After Endoscopic Retrograde Pancreatography With Sphincterotomy

Fernández-Jorge, Beatriz1; García-Silva, Jésus M.D.1; Almagro, Manuel M.D.1; Ruzo, Jose Souto M.D.2; Rey, Enrique Carro M.D.3; Fonseca, Eduardo M.D.1 Author Information

THE IN VIVO ANTITUMORAL EFFECTS OF LIPOPOLYSACCHARIDE AGAINST GLIOBLASTOMA MULTIFORME ARE MEDIATED IN PART BY TOLL-LIKE RECEPTOR 4

Toll-like receptor 4 (Tlr-4) mediates many biological effects of lipopolysaccharide (LPS), which has antitumoral effects on glioblastoma both in vivo and in vitro. However, the precise role of Tlr-4 in these antitumoral effects remains unknown. The role of Tlr-4 in the antitumoral effect of LPS on glioblastomas was assessed in wild-type BALB/c mice and in Tlr-4 knockout (KO) BALB/c mice. Mice were implanted with DBT glioblastoma cells intracranially or subcutaneously, were treated with intratumoral LPS, and were assessed by histopathological examination for degrees of tumor progression and inflammation. Flow cytometry and Western blotting with antibodies to the Tlr-4 receptor and flow cytometry to the related CD14 moiety were performed to quantitate the expression levels of these two receptors by glioblastoma cells. For subcutaneous tumors, LPS caused near complete tumor elimination in wild-type mice, but only a 50% reduction in Tlr-4 KO mice. For mice implanted with intracranial glioblastomas, LPS increased survival times modestly in wild-type mice, but showed no benefit in the Tlr-4 KO mice. There were no histological differences among wild-type and Tlr-4 KO mice, except for tumor size. In both models, an early neutrophilic and later macrophage-rich inflammatory infiltrate were seen after LPS administration. Quantitative flow cytometry and Western blotting showed no Tlr-4 receptor or CD14 expression in murine and human glioblastoma cells in vitro, and Western blotting suggested that Tlr-4 effects are mediated by nontumoral elements such as microglia and inflammatory cells. LPS-induced antitumoral effects on glioblastoma multiforme are mediated, in part, by the Tlr-4 receptor. Further understanding of this process may lead to novel treatment strategies for this uniformly fatal disease.

Hyperbaric oxygen therapy reduces neuroinflammation and expression of matrix metalloproteinase‐9 in the rat model of traumatic brain injury

The acute inflammatory response plays an important role in secondary brain damage after traumatic brain injury (TBI). Neutrophils provide the main source of matrix metalloproteinases (MMPs) which also play a deleterious role in TBI. Numerous preclinical studies have suggested that hyperbaric oxygen therapy (HBOT) may by beneficial in various noncerebral and cerebral inflammatory diseases. The goal of this study was to evaluate the effects of HBOT on inflammatory infiltration and the expression of MMPs in correlation with secondary cell death in the rat model of dynamic cortical deformation (DCD). Twenty animals underwent DCD with subsequent HBOT (2.8 ATA, two sessions of 45 min each); 10 animals: DCD and normobaric oxygenation (1 ATA), 10 animals: not treated after DCD. Cell death was evaluated by TUNEL. Neutrophils were revealed by myeloperoxidase staining. Immunohistochemical staining for MMP-2 and -9 and tissue inhibitors of MMP-1 (TIMP-1) and -2 was also performed and the results were quantitatively evaluated by image analysis. In the animals treated by HBOT, a significant decrease in the number of TUNEL-positive cells and neutrophilic inflammatory infiltration was seen in comparison with nontreated animals and those treated by normobaric oxygen. The expression of MMP-9 was also significantly lower in the treated group. Staining for MMP-2 and TIMP-2 did not change significantly. Our results demonstrate that HBOT decreased the extent of secondary cell death and reactive neuroinflammation in the TBI model. The decline of MMP-9 expression after HBOT may also contribute to protection of brain tissue in the perilesional area. Further research should be centred on the evaluation of long-term functional and morphological results of HBOT.

Lactobacillus johnsoniiLa1 AttenuatesHelicobacter pylori-Associated Gastritis and Reduces Levels of Proinflammatory Chemokines in C57BL/6 Mice

In clinical settings, Lactobacillus johnsonii La1 administration has been reported to have a favorable effect on Helicobacter pylori-associated gastritis, although the mechanism remains unclear. We administered, continuously through the water supply, live La1 to H. pylori-infected C57BL/6 mice and followed colonization, the development of H. pylori-associated gastritis in the lamina propria, and the levels of proinflammatory chemokines macrophage inflammatory protein 2 (MIP-2) and keratinocyte-derived cytokine (KC) in the serum and gastric tissue over a period of 3 months. We documented a significant attenuation in both lymphocytic (P=0.038) and neutrophilic (P=0.003) inflammatory infiltration in the lamina propria as well as in the circulating levels of anti-H. pylori immunoglobulin G antibodies (P=0.003), although we did not observe a suppressive effect of La1 on H. pylori colonizing numbers. Other lactobacilli, such as L. amylovorus DCE 471 and L. acidophilus IBB 801, did not attenuate H. pylori-associated gastritis to the same extent. MIP-2 serum levels were distinctly reduced during the early stages of H. pylori infection in the La1-treated animals, as were gastric mucosal levels of MIP-2 and KC. Finally, we also observed a significant reduction (P=0.046) in H. pylori-induced interleukin-8 secretion by human adenocarcinoma AGS cells in vitro in the presence of neutralized (pH 6.8) La1 spent culture supernatants, without concomitant loss of H. pylori viability. These observations suggest that during the early infection stages, administration of La1 can attenuate H. pylori-induced gastritis in vivo, possibly by reducing proinflammatory chemotactic signals responsible for the recruitment of lymphocytes and neutrophils in the lamina propria.

Ľusage du tube endotrachéal Lanz® réduit les lésions de la trachée chez les chiens

To determine, in dogs anesthetized with nitrous oxide (N2O), (whether the endotracheal tube (ETT) cuffed with a Lanz pressure regulating valve decreases the tracheal consequences of tracheal intubation.Sixteen mixed-breed dogs were allocated to two groups according to the ETT used: Control group (n = 8) - Rüsch ETT, and Lanz group (n = 8) - ETT with Lanz pressure regulating valve. The ETT cuffs in both groups were inflated with air to an intracuff pressure of 30 cm H2O. Anesthesia was induced and maintained with pentobarbitone and N2O (1.5 L x min(-1)) and O2 (1 L x min(-1)). ETT cuff pressures were measured before (control) and 60, 120, and 180 min during N2O administration. The dogs were sacrificed, and biopsy specimens from four predetermined areas of the tracheal mucosa in contact with the ETT were collected for light and scanning electron microscopy (SM) examination.Cuff pressures in the Control group were higher than in the Lanz group at all time points studied (P < 0.001), with an increase over time only in the Control group (P < 0.001). Median neutrophilic inflammatory infiltration values of the epithelial surface, and in the subepithelial layer in contact with the cuff, were higher in the Control group as compared to the Lanz group (3.0 vs 1.0 and 3.0 vs 1.5 respectively) (P < 0.05). On SM examination, median histological grades were higher in the Control group compared to Lanz group (2.9 vs 1.9 respectively), (P < 0.05).The Lanz ETT decreases tracheal mucosal injury in dogs.

Sweet???s Syndrome Presenting as Acute Hand Infection

Sweet's syndrome, originally described as an acute febrile neutrophilic dermatosis, belongs to a class of skin lesions that histologically have intense epidermal and/or dermal inflammatory infiltrate of neutrophils without evidence of infection or vasculitis. Skin lesions of Sweet's syndrome most commonly present on the face, trunk, upper extremities, and hands. The presenting lesions are often confused with infections because of their clinical appearance. A retrospective search of the electronic medical record was performed to identify patients with Sweet's syndrome from 1996 to the present. These records were then reviewed to identify those patients who had Sweet's syndrome that involved the hands. A total of 103 patients with Sweet's syndrome have been seen and treated at Scott and White Memorial Hospital since 1996. Of these, 49 patients had lesions on the hands. The presentation, treatment, and outcomes of several of these patients are presented. As physicians responsible for the treatment of hand lesions, it is important to consider the diagnosis of Sweet's syndrome because these wounds are unresponsive to antibiotics, do not benefit from débridement, and instead, require treatment with steroids.

Menetrier??s disease presenting as an acute protein-losing gastroenteropathy in a 27-year-old man with Gaucher disease

To describe a unique case of a young man with Gaucher disease who was diagnosed with Menetrier's disease. After an acute episode of severe gastritis, the patient developed hypoalbuminemia and protein-losing gastroenteropathy, and became unwell. Endoscopy revealed an abnormal stomach, with rigid, thickened folds covered with viscous greyish exudates. Superficial biopsies revealed foveolar hyperplasia, acute and severe gastritis with massive inflammatory infiltrate of neutrophils in the lamina propria with pit abscess formation. Tissue cultures for Helicobacter pylori were negative. Snare deep particle biopsy revealed the typical features of Menetrier's disease. Enzyme replacement therapy for Gaucher disease was started. This case poses a dilemma because the patient improved spontaneously, and as such is dissimilar to other adults who develop Menetrier's disease because of an infection; it is hoped that he may also not be at risk of the potential malignancies that are correlated with adult Menetrier's disease. The value of enzyme treatment is considered.

Loxosceles Sphingomyelinase Induces Complement-Dependent Dermonecrosis, Neutrophil Infiltration, and Endogenous Gelatinase Expression

Envenomation by the spider Loxosceles can result in dermonecrosis and severe ulceration. Our aim was to investigate the role of the complement system and of the endogenous metalloproteinases in the initiation of the pathology of dermonecrosis. Histological analysis of skin of rabbits injected with Loxosceles intermedia venom and purified or recombinant sphingomyelinases showed a large influx of neutrophils, concomitant with dissociation of the collagenous fibers in the dermis. Decomplementation, using cobra venom factor, largely prevented the influx of neutrophils, while influx of neutrophils was also reduced in genetically C6-deficient rabbits, suggesting roles for both C5a and the membrane attack complex in the induction of dermonecrosis. However, C-depletion and C6 deficiency did not prevent the haemorrhage and the collagen injury. Zymography analysis of skin extracts showed the induction of expression of the endogenous gelatinase MMP-9 in the skin of envenomated animals. Rabbit neutrophils contained high levels of MMP-9, expression of which was further increased after incubation with venom, suggesting that these cells may be a source of the MMP-9 found in the skin of envenomated animals. Furthermore, skin fibroblasts also secreted MMP-9 and MMP-2 upon incubation with venom, suggesting that locally produced MMPs can also contribute to proteolytic tissue destruction.

JP-8 jet fuel exposure induces inflammatory cytokines in rat skin

The Department of Defense (DoD) has identified that one of the main complaints of personnel exposed to JP-8 jet fuel is irritant dermatitis. The purpose of this investigation is to describe the JP-8-induced inflammatory cytokine response in skin. JP-8 jet fuel or acetone control (300 μl) was applied to the denuded skin of rats once a day for 7 days. Skin samples from the exposed area were collected 2 and 24 h after the final exposure. Histological examination of skin biopsies showed neutrophilic inflammatory infiltrate. Reverse transcription-polymerase chain reaction (RT-PCR) was performed utilizing skin total RNA to examine the expression of various inflammatory cytokines. The CXC chemokine GROα was significantly upregulated at both time points, whereas GROβ was only increased 2 h post final exposure. The CC chemokines MCP-1, Mip-1α, and eotaxin were induced at both time points, whereas Mip-1β was induced only 24 h post exposure. Interleukins-1β and -6 (IL-1β and IL-6) mRNAs were significantly induced at both time points, while TNFα was not significantly different from control. Enzyme-linked immunosorbent assay (ELISA) of skin protein confirmed that MCP-1, TNFα, and IL-1β were modulated as indicated by PCR analysis. However, skin IL-6 protein content was not increased 2 h post exposure, whereas it was significantly upregulated by jet fuel after 24 h. Data from the present study indicate that repeated (7 days) JP-8 exposure induces numerous proinflammatory cytokines in skin. The increased expression of these cytokines and chemokines may lead to increased inflammatory infiltrate in exposed skin, resulting in JP-8-induced irritant dermatitis.

An Unusual Neutrophilic Dermatosis

The neutrophilic dermatoses are a heterogeneous group of cutaneous disorders unified by common histologic findings of a noninfectious, extensive dermal neutrophilic inflammatory infiltrate. Systemic manifestations are common, often with overlapping clinical features among this group of inflammatory dermatoses. This diverse group of diseases has historically been subclassified based upon the presence or absence of vasculitis. This has been a controversial point as entities originally characterized as lacking vascular damage have been shown to occasionally display evidence of vascular injury. Whether the injury to vessels is the primary pathogenetic mechanism, as in immune complex-mediated injury, or a secondary phenomenon, is often difficult to determine on histopathologic grounds alone. Entities to be discussed are inflammatory dermatoses characterized by a dense dermal neutrophilic infiltrate, including Sweet syndrome, pyoderma gangrenosum, rheumatoid neutrophilic dermatitis, bowel associated dermatitis-arthritis syndrome, Behçet disease, erythema elevatum diutinum (EED) and granuloma faciale (GF).

SOCS3 Is a Critical Physiological Negative Regulator of G-CSF Signaling and Emergency Granulopoiesis

To determine the importance of suppressor of cytokine signaling-3 (SOCS3) in the regulation of hematopoietic growth factor signaling generally, and of G-CSF-induced cellular responses specifically, we created mice in which the Socs3 gene was deleted in all hematopoietic cells. Although normal until young adulthood, these mice then developed neutrophilia and a spectrum of inflammatory pathologies. When stimulated with G-CSF in vitro, SOCS3-deficient cells of the neutrophilic granulocyte lineage exhibited prolonged STAT3 activation and enhanced cellular responses to G-CSF, including an increase in cloning frequency, survival, and proliferative capacity. Consistent with the in vitro findings, mutant mice injected with G-CSF displayed enhanced neutrophilia, progenitor cell mobilization, and splenomegaly, but unexpectedly also developed inflammatory neutrophil infiltration into multiple tissues and consequent hind-leg paresis. We conclude that SOCS3 is a key negative regulator of G-CSF signaling in myeloid cells and that this is of particular significance during G-CSF-driven emergency granulopoiesis.

Anti‐p200‐Pemphigoid – Eine neue blasenbildende Autoimmundermatose

ZusammenfassungDas Anti‐p200‐Pemphigoid ist eine neue Autoimmunerkrankung der Haut, die klinisch durch pralle Blasen und histopathologisch durch eine subepidermale Spaltbildung mit einer überwiegend neutrophilen Infiltration der dermo‐epidermalen Junktionszone (DEJ) gekennzeichnet ist. Die direkte Immunfluoreszenz periläsionaler Hautbiopsien zeigt lineare Ablagerungen von IgG und C3 entlang der DEJ, während sich mittels indirekter Immunfluoreszenz zirkulierende IgG‐Antikörper gegen die dermale Seite NaCl‐gespaltener normaler Haut nachweisen lassen. Das Zielantigen der Autoantikörper ist ein 200 kD schweres Protein (p200) der unteren Lamina lucida, welches im Immunoblot mit Extrakten humaner Dermis erkannt wird. Die genaue Identität von p200, das offensichtlich eine wichtige Funktion für die Zell‐Matrix‐Adhäsion hat, ist noch unklar. Die bisherigen Untersuchungen konnten dieses Autoantigen jedoch von BP180, BP230, Laminin 1, 5 und 6, α6β4‐Integrin und Typ‐VII‐Kollagen abgrenzen. Die biochemische Charakterisierung von p200 zeigte, daß es sich hierbei um ein nichtkollagenes, N‐glykosiliertes, saueres Protein mit einem isoelektrischen Punkt von ca. 5,5 handelt. Die vorliegende Arbeit gibt einen Überblick zu Pathogenese, Klinik, Diagnostik und Therapie dieser neuen Autoimmundermatose.

Critical role for a high-affinity chemokine-binding protein in gamma-herpesvirus-induced lethal meningitis.

Chemokines are involved in recruitment and activation of hematopoietic cells in sites of infection and inflammation. The M3 gene of the gamma-herpesvirus gammaHV68 encodes an abundant secreted protein that binds CC chemokines with high affinity. We report here that this gene is essential for efficient induction of lethal meningitis by gammaHV68. An M3 mutant gammaHV68 (gammaHV68-M3.stop) was 100-fold less virulent than wild-type or marker rescue control (gammaHV68-M3.MR) viruses after intracerebral inoculation. After intracerebral inoculation, gammaHV68-M3.stop grew to lower titers than gammaHV68 or gammaHV68-M3.MR in the brain but spread to and grew normally in the spleen and lung. Expression of several CC chemokines was significantly induced in the CNS by gammaHV68 infection. Consistent with M3 acting by blockade of CC chemokine action, gammaHV68 induced a neutrophilic meningeal inflammatory infiltrate, while gammaHV68-M3.stop induced an infiltrate in which lymphocytes and macrophages predominated. In contrast to the important role of M3 in lethal meningitis, M3 was not required for establishment or reactivation from latent infection or induction of chronic arteritis. These data suggest a role for chemokines in the protection of the nervous system from viral infection and that the M3 protein acts in a tissue-specific fashion during acute but not chronic gammaHV68 infection to limit CC chemokine-induced inflammatory responses.

Neutrophil Migration During Liver Cirrhosis In Rabbits

1. The aim of the present study was to investigate neutrophil chemotaxis during the induction of liver cirrhosis in rabbits. 2. Liver cirrhosis was induced in male New Zealand white rabbits. The study consisted of three experimental groups: (i) group A (n=16) served as the control and received only normal chow and all rabbits in this group were killed at 16 weeks; (ii) group B rabbits (n=8) were killed immediately after the chemotaxis assay, which was performed 24 h after CCl4 administration, at weeks 2, 4, 6 and 8; and (iii) in group C rabbits (n=19), the chemotaxis assay was performed every second week on the day before CCl4 administration for 16 weeks and all animals in this group were killed at 16 weeks. 3. Four of six rabbits in group B had liver cirrhosis at week 8. In group C, liver cirrhosis occurred in seven of eight animals. All rabbits with liver cirrhosis had an inflammatory infiltrate of neutrophils. In group B, there was a significant increase in polymorphonuclear cells and neutrophil chemotaxis and a significant reduction in mononuclear leucocytes at week 8. The rabbits in group C showed a significant increase in total leucocyte and polymorphonuclear numbers at week 10. A significant increase in neutrophil chemotaxis was also observed from week 2 through to week 6. 4. The presence of neutrophils in the liver of all rabbits with cirrhosis, associated with an increase in polymorphonuclear cell chemotaxis during this process, supports the view that this cell type has an important role in the development of toxic liver damage.

Delayed pressure urticaria.

Delayed pressure urticaria is a physical urticaria where erythematous, often painful swellings occur at sites of sustained pressure on the skin, after a delay of several hours. If sought, it is present in up to 40% of patients with ordinary chronic "idiopathic urticaria" to a varying degree. Compared with other urticarias, the pressure-induced lesions impair the quality of life of patients most severely. The pathogenesis is not well characterized, but whealing is dependent on mast cell activation, with the histology of lesions also showing a deep dermal inflammatory infiltrate of neutrophils and eosinophils, without vasculitis. Treatment of delayed pressure is generally unsatisfactory, and is often resistant to antihistamine and a range of anti-inflammatory medication. Oral steroids, although the most effective therapy, are unsuitable for long-term use. Delayed pressure urticaria may persist for many years, and improved or novel methods of management are under investigation.

Abdominal ultrasound in acute schistosomiasis mansoni.

Reports on abdominal ultrasound studies in patients with acute schistosomiasis are still scarce and limited data are available on structural changes of the liver parenchyma in this stage of the disease. 26 patients with acute schistosomiasis mansoni were submitted to clinical and ultrasound examination. For ultrasound comparison, each acute patient was paired by age, gender, weight and height to a non-infected individual. Ultrasound showed a non-specific homogeneous size increase of the liver, and spleen in all acute patients, and easily identified intraabdominal lymph nodes in the periportal region in most cases. Three out of the five patients with periportal thickening underwent percutaneous liver biopsy. Periportal thickening disappeared 6 months after treatment for schistosomiasis. 24 months after successful treatment there was involution of the liver and spleen; lymph nodes, although reduced in size, were still easily recognized. Liver biopsy showed dense inflammatory infiltration of neutrophils, macrophages and eosinophils in the portal tracts associated with discrete fibrous tissue formation.

Leucocyte activation in erythema nodosum.

As a neutrophilic vascular reaction of small vessels in the subcutaneous tissue and a neutrophilic inflammatory infiltrate are common histopathological features found in initial erythema nodosum (EN) lesions, we asked the question whether activated polymorphonuclear neutrophils (PMN) might play a role in the pathogenesis of EN. We analysed the production of reactive oxygen intermediates (ROI) as a marker for activated neutrophils in the peripheral blood of patients suffering from EN (n = 10) and healthy volunteers (n = 10). FACS analysis of dihydrorhodamine 123-stained PMN was used to detect ROI production due to respiratory burst activity. Patients suffering from EN had a fourfold higher percentage of preactivated ('primed') ROI-producing PMN compared with healthy volunteers. Activation of PMN with formylated methionyl-leucyl-phenylalanine and phorbol 12-myristate 13-acetate led to an increase of ROI production per cell but had no influence on the percentage of activated cells. The percentage of ROI-producing cells in patients with EN correlated with the clinical severity. From these data, we conclude that ROI might play a role in the pathogenesis of EN. ROI might exert their effects by oxidative tissue damage and by promoting tissue inflammation.

Acquired cutis laxa associated with chronic urticaria

A 31-year-old man had cutis laxa after an urticarial eruption. He had no systemic manifestations. In urticarial lesions, elastolysis occurred only within the inflammatory infiltrate of neutrophils around the vessels and between the collagen bundles. In lax skin, elastolysis occurred throughout the entire dermis. Electron microscopic study showed a markedly decreased number of elastic fibers, with elastolysis most predominant near the inflammatory cells. These findings suggest that the neutrophil plays a significant role in the destruction of elastic fibers and subsequent development of cutis laxa.

Histopathologic patterns of erythema migrans and borrelial lymphocytoma

Erythema migrans and borrelial lymphocytoma are early signs of Lyme borreliosis. After infection with Borrelia burgdorferi via a tick bite, the body undergoes a series of events in an attempt to destroy the microorganism or limit its spread to other sites. Biopsies taken from patients soon after a tick bite show the tick head and neighboring skin with edema, vascular dilation, extravasation of erythrocytes, and an inflammatory infiltrate of neutrophils and eosinophils. If the spirochetes persist in the skin, the infiltrate shows predominantly lymphocytes and, in many circumstances, plasma cells. The infiltrates in the early phase of the disease are histologically characterized by the presence of both B and T lymphocytes (helper and suppressor phenotypes), macrophages, interdigitating reticulum cells, mast cells, and plasma cells. After dissemination, B. burgdorferi appears to cause direct organ damage or to provoke immune mechanisms resulting in inflammation. 1