Acute Inflammatory Infiltrate Research Articles

Impact of Dual-coated Silver Nanoparticle and Antibiotic Sutures on Wound Healing in Inflammatory Mouse Models

ABSTRACT Background: The use of silver nanoparticles (AgNPs) in biomedicine has emerged in a big way owing to its antibacterial and anti-inflammatory properties. We hypothesize that combining the AgNPs with antibiotics for coating sutures will enhance the antibacterial property of sutures with the added advantage of the immunomodulatory effect of AgNPs on tissue healing. Materials and Methods: Polyglactin sutures were coated with AgNPs using the dip-coating method. The uniform coating and morphology of AgNPs on the suture surface were confirmed using scanning electron microscopy (SEM). Each type of suture – polyglactin plain, antibiotic coated (Triclosan), AgNP coated, and dually coated (antibiotic and AgNP) – was assessed for their antibacterial properties against Gram-positive bacteria, Gram-negative bacteria, and anaerobes. These sutures were utilized in an abdominal and systemic inflammatory mice model for ileal anastomosis. The intestinal tissue was evaluated for acute and chronic inflammation and collagen deposition to assess the healing and inflammatory response. Results: The SEM and energy dispersive X-ray analysis showed successful coating of AgNPs on plain and antibiotic-coated sutures. In comparison with the other groups, the dually coated suture had the best in vitro antibacterial efficacy. The AgNP-coated sutures were able to decrease both acute and chronic inflammatory cell infiltration, but the collagen synthesis and deposition were enhanced. Conclusion: AgNPs can be coated on Polyglactin suture either alone or in combination with antibiotics with preserved antibacterial effects. The dual coating of sutures gives a synergistic antibacterial effect. The AgNP diminishes immune response in the presence of preserved extracellular matrix generation.

Ophiopogonin D alleviates acute lung injury by regulating inflammation via the STAT3/A20/ASK1 axis

BackgroundAcute lung injury (ALI) is characterized by acute pulmonary inflammatory infiltration. Alveolar epithelial cells (AECs) release numerous pro-inflammatory cytokines, which result in the pathological changes seen in ALI. Ophiopogonin D (OD), extracted from the roots of Ophiopogon japonicus (Thunb.) Ker Gawl. (Liliaceae), reduces inflammation; however, the efficacy of OD in ALI has not been reported and the underlying molecular mechanisms remain unclear. PurposeThis study investigated the anti-inflammatory effects of OD, as well as the underlying mechanisms, in AECs and a mouse ALI model. MethodsLipopolysaccharide (LPS) and tumor necrosis factor-α (TNF-α) were used to stimulate macrophages and A549 cells, and a mouse ALI model was established by intratracheal LPS administration. The anti-inflammatory effects and mechanisms of OD in the TNF-α-induced in vitro inflammation model was evaluated using real-time quantitative polymerase chain reaction qPCR), enzyme-linked immunosorbent assay (ELISA), western blotting, nuclear and cytoplasmic protein extraction, and immunofluorescence. The in vivo anti-inflammatory activity of OD was evaluated using hematoxylin and eosin staining, qPCR, ELISA, and western blotting. ResultsThe bronchoalveolar lavage fluid and lung tissue of LPS-induced ALI mice exhibited increased TNF-α expression. TNF-α induced a significantly greater pro-inflammatory effect in AECs than LPS. OD reduced inflammation and mitogen-activated protein kinase (MAPK) and transcription factor p65 phosphorylation in vivo and in vitro and promoted signal transducer and activator of transcription 3 (STAT3) phosphorylation and A20 expression, thereby inducing apoptosis signal-regulating kinase 1 (ASK1) proteasomal degradation. ConclusionOD exerts an anti-inflammatory effect by promoting STAT3-dependent A20 expression and ASK1 degradation. OD may therefore have therapeutic value in treating ALI and other TNF-α-related inflammatory diseases.

The effect of cellular nuclear function alteration on the pathogenesis of shoulder adhesive capsulitis: an immunohistochemical study on lamin A/C expression

BackgroundThe network of intermediate filament proteins underlying the inner nuclear membrane forms the nuclear lamina. Lamins have been associated with important cellular functions: DNA replication, chromatin organization, differentiation of the cell, apoptosis and in maintenance of nuclear structure.Little is known regarding the etiopathogenesis of adhesive capsulitis (AC); recently, a dysregulating fibrotic response starting from a subpopulation has been described within the fibroblast compartment, which suddenly turns on an activated phenotype.Considering the key role of A-type lamins in the regulation of cellular stability and function, our aim was to compare the lamin A/C expression between patients with AC and healthy controls.Materials and methodsA case–control study was performed between January 2020 and December 2021. Tissue samples excised from the rotator interval were analysed for lamin A/C expression by immunohistochemistry. Patients with AC were arbitrarily distinguished according to the severity of shoulder flexion limitation: ≥ 90° and < 90°. Controls were represented by samples obtained by normal rotator interval excised from patients submitted to shoulder surgery. The intensity of staining was graded, and an H-score was assigned. Statistical analysis was performed (Chi-square analysis; significance was set at alpha = 0.05).ResultsWe enrolled 26 patients [12 male and 14 female, mean age (SD): 52.3 (6.08)] and 15 controls [6 male and 9 female, mean age (SD): 57.1 (5.3)]. The expression of lamin A/C was found to be significantly lower in the fibroblasts of patients with adhesive capsulitis when compared with controls (intensity of staining: p: 0.005; H-score: 0.034); no differences were found regarding the synoviocytes (p: > 0.05). Considering only patients with AC, lamin A/C intensity staining was found to be significantly higher in samples where acute inflammatory infiltrate was detected (p: 0.004).No significant changes in levels of lamin A/C expression were documented between the mild and severe adhesive capsulitis severity groups.ConclusionsOur study demonstrated that the activity of lamin A/C in maintaining nuclear structural integrity and cell viability is decreased in patients with adhesive capsulitis. The phase of the pathogenetic process (freezing and early frozen) is the key factor for cell functionality. On the contrary, the clinical severity of adhesive capsulitis plays a marginal role in nuclear stability.Level of evidenceIII.

Lymphoepithelioma-like carcinoma: a rare case of rectal cancer.

Lymphoepithelioma-like carcinoma (LELC) is a histological variant that resembles nasopharyngeal lymphoepithelioma and occurs in various locations such as the salivary glands and lung. LELCs in the digestive tract are rare, accounting for only 2% of cases, being exceptional in the rectum. We present the case of an 84-year-old man with rectorrhagia, whitish malodorous discharge and constipation of one month's duration. Rectal examination identified a tumour. Colonoscopy revealed a rectal lesion that was confirmed by biopsy as malignant, and MRI showed an extensive rectal tumour. Histopathology revealed undifferentiated carcinoma with acute inflammatory infiltrate, consistent with LELC. Immunohistochemistry was positive for keratins 5/6, 18, 20, CEA and BER.EP4, while in situ hybridisation for Epstein-Barr virus (EBV) RNA was negative. The multidisciplinary decision included neoadjuvant radiotherapy and anterior rectal resection. The patient remains in complete response two years after treatment. Histologically, LELC is characterised by an acute inflammatory infiltrate interspersed with poorly differentiated neoplastic cells. The stomach is the most commonly affected region in the gastrointestinal tract, with more than 80% of gastric LELCs associated with EBV. To date, only four cases of rectal LELC have been reported, and its association with EBV was demonstrated in only one case. There are no standard treatments for rectal LELC, underscoring the need to gather more cases to understand its pathogenesis and develop effective treatment strategies.

Evaluation of calcium hydroxide mixed with propolis by ultrasonic activation as root canal dressing in delayed tooth replantation.

In cases of tooth avulsion, in which the neurovascular bundle responsible for nourishing the dental pulp is break, endodontic treatment is necessary before proceeding with tooth replantation. In this process, various substances have been tested in combination with calcium hydroxide Ca(OH)2 in an attempt to improve its effectiveness. This study aimed to examine the effects of using a mixture of Ca(OH)2 and 10% propolis, with subsequent application of ultrasonic treatment, on the delayed replantation of teeth in rats. Twenty-four rats underwent a surgical procedure to extract the upper right incisor, leaving it on a surface to dry for one hour. The pulp and periodontal ligament were removed and the teeth were submerged in a 2% sodium fluoride acidulated phosphate solution. The canals were dehydrated using paper cones and the teeth were divided into four groups, according to the type of intracanal dressing: Ca(OH)2 group, Ca(OH)2 group with ultrasonic agitation, Ca(OH)2 and propolis group, Ca(OH)2 and propolis group with ultrasonic agitation. The root canals were irrigated with saline solution and the teeth were reimplanted. Sixty days after reimplantation, the animals were euthanized. With regard to the presence of acute and chronic inflammatory infiltrate in the periodontal ligament, there was no statistically significant difference among some of the groups. Root resorption was identified in all groups, and there was no significant difference between them. It is concluded that the application of intracanal dressing containing Ca(OH)2 associated with 10% propolis, followed by ultrasonic agitation, did not prove to be more effective than the use of Ca(OH)2 alone in the repair process in the delayed replantation of rat teeth. Key words:Tooth replantation, Calcium hydroxide, Propolis, Ultrasound, Intracanal dressing.

Congenital Pulmonary Airway Malformation Type 1 with Pulmonary Neuroendocrine Cell Hyperplasia in an Adult Male: a Rare Case Report

Abstract Introduction/Objective Congenital pulmonary airway malformations (CPAM) is rare, usually diagnosed in the pediatric population, and may occur in adults. Pulmonary neuroendocrine cell hyperplasia (PNECH) mimicking diffuse idiopathic pulmonary neuroendocrine cell hyperplasia (DIPNECH) associated with CPAM has not been described previously. We report a case of CPAM Type 1 with PNECH. Methods/Case Report A 33-year-old male, with past medical history of latent tuberculosis (TB) by Quantiferon blood testing, recurrent pneumonia, recurrent lung abscesses, and lung cavitary lesion for three years, presented with fever, cough with hemoptysis, shortness of breath, and left-sided chest pain. Computerized tomography of chest displayed a 10.8 cm cavitary lesion in the left lower lobe of the lung. The patient underwent left lower lobectomy of the lung. Grossly, the lobectomy specimen revealed a 10.5 cm irregular cavity communicating to the superior segmental bronchus of the left lower lobe. Microscopically, the dominant large cyst was surrounded by lung parenchyma and small cystically dilated spaces resembling bronchioles under the fibrotic pleura. The large cyst was lined by respiratory epithelium with rare pathognomonic mucous cells in clusters. Cyst walls contained smooth muscle, small islands of cartilage, and focal intense acute and chronic inflammatory cell infiltrates with hemorrhage. There were multiple foci of proliferation of pulmonary neuroendocrine cells centered around bronchioles surrounding the large cyst. The neuroendocrine cells were arranged from individual cells and cellular aggregates to larger tumorlets, highlighted by Synaptophysin and Chromogranin immunostains. No granuloma or necrosis was present. No acid-fast bacilli or fungal microorganisms were identified by special stains. The findings are consistent with CPAM type 1, with PNECH. Results (if a Case Study enter NA) NA Conclusion Our study demonstrates a histologically diagnosed adult congenital pulmonary airway malformations type 1 with an incidental pulmonary neuroendocrine cell hyperplasia, which mimics diffuse idiopathic pulmonary neuroendocrine cell hyperplasia. To the best of our knowledge, this is the first report of such an association.

Results of the morphological and immunohistochemical study of the consequences in premature birth and premature rupture of the membrane

The article presents the results of a morphological and immunohistochemical study of the afterbirths of women with miscarriages in cases of premature rupture of membranes (PRPO).The aim: to study the morphological and immunohistochemical features of placentas in premature births and premature rupture of membranes and to conduct a comparative analysis of the results depending on the gestational period.Material and methods. A morphological and immunohistochemical study of the litters of 250 pregnant women (the main group) with spontaneous premature births at 22-36 weeks of gestation and premature rupture of the membranes, which took place on the basis of the Department for Pregnant Women with Obstetric Pathology of the PAG Institute named after Acad. OHM. Lukyanova National Academy of Sciences of Ukraine" for the period from 2018 to 2020. The women of the main group are divided into three groups depending on the date of delivery - the 1st group includes patients who gave birth at 22-28 weeks of pregnancy, patients of the 2nd group who gave birth at 29-33 weeks, and to the 3rd group - those who gave birth at 34-36 weeks of pregnancy. Placentas of pregnant women of the main group were examined using morphological (histological method - staining with hematoxylin and eosin and van Gieson) and immunohistochemical methods (indirect streptavidin-peroxidase method for determining the expression level of progesterone receptors - RP).Results and discussion. Premature maturation of chorionic villi was found in 40 % of placentas of women in the 1st group 1, in 20 % – blood circulation disorders and the presence of acute inflammatory infiltration in the fetal membranes, decidual and chorionic membranes, 10 % – pathological immaturity of the placenta according to the variant of chaotic sclerosed villi. During the immunohistochemical study of RP, an unexpressed reaction was found in the epithelium and stromal cells of the stem, intermediate and terminal villi – 1 point; in fetal membranes and extra-villous cytotrophoblast – 2 points; in the endothelium of vessels – 0–1 point. In the placentas of women in the 2nd and 3nd group premature maturation of villi was found in 70 % of cases, pseudo-infarcts of villi which are embedded in fibrinoid occupying a significant area – 45 %, afunctional zones – 55 %, blood circulation disorders – 35 %, pathological immaturity placenta according to the variant of chaotic, sclerosed villi – 20 %, acute inflammatory infiltration in the fetal membranes – 15 %. Immunohistochemical analysis of the placental barrier revealed the highest expression of RP in the nuclei of decidual cell which belong to the maternal structure. Of note is the presence of progesterone receptor expression in stem villi, fibroblasts, and vessel wall nuclei. Minimal or absent expression was determined in the nuclei of other villous structures and their vessels. Conclusions. It has been proven that the receptivity of progesterone has its own characteristics in placental structures depending on the gestation period, which is an important factor in the choice of management for the prevention and reduction of perinatal losses for this contingent of pregnant women. The conducted studies make it possible to formulate a clear concept of pathogenetically justified therapy for miscarriage.

Poly(Aspartic Acid) Promotes Odontoblast-like Cell Differentiation in Rat Molars with Exposed Pulp.

Mechanical pulp exposure was performed in the upper molars of 56 Wistar rats, randomly divided as follows (n = 14): control (no treatment); MTA group-pulp capping with mineral trioxide aggregate (MTA Angelus); pAsp group-application of 20 μL of pAsp solution (25 mg·mL-1); MTA+pAsp group-application of MTA mixed with pAsp (5:1 by mass). Animals were euthanized after 7 or 21 days. Histological sections were submitted to hematoxylin-eosin and Brown and Brenn staining and immunohistochemical analysis for osteopontin (OPN) and dentin matrix protein 1 (DMP 1). At 7 days, an acute inflammatory infiltrate and the presence of disorganized mineralized tissue were observed in all groups. At 21 days, the quality and thickness of the reparative dentin in treated groups were superior to the control, and bacterial contamination was observed in two MTA-pAsp specimens. While all treated groups showed intense immunostaining for OPN at 21 days, only the pAsp group expressed DMP 1, indicating the presence of fully differentiated odontoblast-like cells. Poly(aspartic) acid promoted dentin regeneration in rat molars in the absence of an additional calcium source and may be an alternative to MTA as a pulp-capping agent.

Cytological changes in respiratory epithelium in association with marijuana smoking

Marijuana is one of the commonly used illicit drugs in Nigeria. This study evaluated the cytological changes in the respiratory epithelium associated with marijuana smoking in Calabar Municipality, Cross River State, Nigeria. This study was a cross- sectional study involving 100 marijuana smokers and 50 marijuana non-smokers, aged 15 years and above. Sputum samples were aseptically collected, and smears prepared. The smears were fixed in ethyl alcohol and were stained using Giemsa and Papanicolaou staining techniques. The stained smears were examined using x10 and x40 objectives of light microscope. Photomicrographs of stained smears were obtained. Data were represented in percentages in tables. Chi-square was used to determine statistical difference between two categorical variables. P-values &lt; 0.05 were considered significant. Marital status, level of education and age of subjects significantly influenced the smoking of marijuana (p=0.001). There was a significant increase in the number of marijuana smokers between the age of 15 – 24(p=0.001) when compared with other age groups. There were also significant abnormalities (p=0.001) observed in the respiratory epithelium of marijuana smokers when compared with non-marijuana smokers. Respiratory cytology smears from marijuana smokers who have smoked for at least 10 years showed mild to moderate metaplasia, numerous acute and chronic inflammatory infiltrates while those who have smoked for more than 10 years showed giant epithelial cells, multinucleated cells and clumps of dysplastic cells. Data from this study showed that marijuana smoking causes inflammatory and dysplastic changes in the respiratory epithelium.

Common Diagnostic Challenges and Pitfalls in Segmental Colitis Associated with Diverticulosis (SCAD).

Segmental colitis associated with diverticulosis (SCAD) is characterized by inflammation involving the sigmoid inter-diverticular mucosa, sparing the proximal colon and rectum. Due to the heterogeneity of clinical manifestations and endoscopic and histological findings, SCAD diagnosis might be challenging in clinical practice. This narrative review aimed to report the SCAD diagnostic criteria adopted in different studies, highlighting the current challenges and main pitfalls in its diagnosis. We analysed fourteen studies, mainly prospective observational studies. Haematochezia and rectal bleeding were the main complaints leading to diagnosis, followed by diarrhoea. An accurate endoscopic description was performed in 86% of studies, while a standardised biopsy sampling protocol (sigma, proximal colon and rectum) was scarcely adopted, being complete only in 28.5% of studies. The evaluation of concomitant drugs potentially inducing colitis was carried out in only 57% of studies. Great heterogeneity in sigmoid endoscopic (edema, erythema, erosions, ulcers, mucosal friability) and histological findings (chronic and/or acute inflammatory infiltrate) was observed. We showed that SCAD diagnosis is often based on not fully adequate macroscopic colonic description and scant biopsy protocol sampling. An accurate clinical and endoscopic evaluation, with an adequate sampling biopsy protocol, with attention to differential diagnosis, seemed to be crucial for a prompt SCAD diagnosis.

P19 Diagnostic conundrums in paraneoplastic pemphigus

Abstract Paraneoplastic pemphigus (PNP) is a subset of pemphigus, a group of autoimmune blistering skin disorders. A 51-year-old man presented with paraneoplastic pemphigus associated with a hepatic neoplasm. He described an epigastric mass and associated mucositis affecting the orogenital mucosae, as well as the sclerae. Both computed tomography and magnetic resonance imaging demonstrated a 14-cm mass arising from the left lobe of the liver. A liver biopsy showed features of an atypical spindle-cell neoplasm, but a definite diagnosis was not possible. A diagnostic skin biopsy was taken from his outer lip mucosae. Histology showed surface ulceration with an acute inflammatory infiltrate, lichenoid lymphoplasmacytic infiltrate with focal basal vacuolar change, degenerate keratinocytes and adjacent suprabasal acantholysis and spongiosis. Perilesional direct immunofluorescence (DIF) was negative; however, indirect immunofluorescence (IIF) showed intercellular IgG antibodies on transitional epithelium with a high titre of 1 : 800 to rat bladder. These finding were consistent with the suspected clinical diagnosis of paraneoplastic pemphigus. The patient was commenced on oral prednisolone 1 mg kg−1 daily. Topical therapy included budesonide mixed with sweetener applied to the oral mucosae. Following this, a trial of 3 days of intravenous methylprednisolone along with 2% cocaine mouthwash, triple mouthwash (betamethasone, doxycycline and nystatin) and Dermovate® ointment was commenced, with improvement noted in pain, haemorrhage and ulceration. Intravenous immunoglobulin was administered preoperatively. The patient was subsequently transferred to a specialist centre for hepatobiliary surgery and listed for debulking of the liver mass. Postoperatively, he had plasmapheresis, with a noted reduction in mucosal ulceration and significant improvement in pain. Chemotherapy with doxorubicin and ifosfamide was initiated thereafter. PNP is a severe autoimmune blistering disorder characterized clinically by flaccid blisters and erosions. Although much is yet to be understood regarding the pathophysiology of PNP, studies show that the development of autoantibodies to the plakin family and desmogleins 1 and 3 play a particular role in its pathogenesis. In addition to autoantibodies, CD8+ T cells have also been shown to contribute to the development of PNP. In adults, the majority of cases are associated with an underlying haematological malignancy and, rarely, a solid-organ tumour. DIF findings include IgG and C3 deposition along the intercellular and basement membrane zones, while IIF detects autoantibodies to proteins found in transitional or stratified squamous epithelium. As in our case, reports have shown that the DIF can be negative, with one study showing a positive DIF in only 41% of cases. This case highlights the complex diagnostic and treatment challenges practitioners face when dealing with PNP and the patients it affects.

Role of Hydrodistention and Intravesical Hyaluronic Acid in Treatment of Bladder Pain Syndrome: Case Report

Bladder pain syndrome (BPS) causes decreased mental and physical quality of life. The diagnosis and treatment of BPS must be made effective; however, the treatment of BPS was still not satisfactory for most patients. Two cases of BPS were presented to the urology clinic and were treated with a combination of hydrodistention and intravesical hyaluronic acid (HA) periodically. After 3-8 hydrodistension and hyaluronic acid instillation, the patients showed symptom improvement indicated by O’Leary Sant Questionnaire (symptom score 19-21 before treatment became 3-4 after treatment, problem score 8-16 before treatment became 0-2 after treatment), visual analogue scale (7-10 before treatment to 3-4 after treatment), and the global response assessment (GRA) scale were markedly improved. Both patients had glomerulations during cystoscopy, and the second had Hunner Lesion. A pathological examination of bladder biopsy specimens indicated acute and chronic inflammatory cell infiltration. The combination of hydrodistention and intravesical HA was beneficial for treating BPS in this study. Further study such as a clinical trial is needed to prove the efficacy and safety of this treatment.

Role of Hydrodistention and Intravesical Hyaluronic Acid in Treatment of Bladder Pain Syndrome: Case Report

Bladder pain syndrome (BPS) causes decreased mental and physical quality of life. The diagnosis and treatment of BPS must be made effective; however, the treatment of BPS was still not satisfactory for most patients. Two cases of BPS were presented to the urology clinic and were treated with a combination of hydrodistention and intravesical hyaluronic acid (HA) periodically. After 3-8 hydrodistension and hyaluronic acid instillation, the patients showed symptom improvement indicated by O’Leary Sant Questionnaire (symptom score 19-21 before treatment became 3-4 after treatment, problem score 8-16 before treatment became 0-2 after treatment), visual analogue scale (7-10 before treatment to 3-4 after treatment), and the global response assessment (GRA) scale were markedly improved. Both patients had glomerulations during cystoscopy, and the second had Hunner Lesion. A pathological examination of bladder biopsy specimens indicated acute and chronic inflammatory cell infiltration. The combination of hydrodistention and intravesical HA was beneficial for treating BPS in this study. Further study such as a clinical trial is needed to prove the efficacy and safety of this treatment.

Crohn’s disease proteolytic microbiota enhances inflammation through PAR2 pathway in gnotobiotic mice

ABSTRACT Emerging evidence implicates microbial proteolytic activity in ulcerative colitis (UC), but whether it also plays a role in Crohn’s disease (CD) remains unclear. We investigated the effects of colonizing adult and neonatal germ-free C57BL/6 mice with CD microbiota, selected based on high (CD-HPA) or low fecal proteolytic activity (CD-LPA), or microbiota from healthy controls with LPA (HC-LPA) or HPA (HC-HPA). We then investigated colitogenic mechanisms in gnotobiotic C57BL/6, and in mice with impaired Nucleotide-binding Oligomerization Domain-2 (NOD2) and Protease-Activated Receptor 2 (PAR2) cleavage resistant mice (Nod2 −/−; R38E-PAR2 respectively). At sacrifice, total fecal proteolytic, elastolytic, and mucolytic activity were analyzed. Microbial community and predicted function were assessed by 16S rRNA gene sequencing and PICRUSt2. Immune function and colonic injury were investigated by inflammatory gene expression (NanoString) and histology. Colonization with HC-LPA or CD-LPA lowered baseline fecal proteolytic activity in germ-free mice, which was paralleled by lower acute inflammatory cell infiltrate. CD-HPA further increased proteolytic activity compared with germ-free mice. CD-HPA mice had lower alpha diversity, distinct microbial profiles and higher fecal proteolytic activity compared with CD-LPA. C57BL/6 and Nod2 −/− mice, but not R38E-PAR2, colonized with CD-HPA had higher colitis severity than those colonized with CD-LPA. Our results indicate that CD proteolytic microbiota is proinflammatory, increasing colitis severity through a PAR2 pathway.

Eosinophilic Annular Erythema as a Subset of Wells Syndrome or a Distinct Entity: Report of Two Cases

Eosinophilic annular erythema (EAE) is an uncommon acute eosinophilic dermatosis of unknown etiology. Urticarial papules and plaques as pruritic lesions appear in annular and arcuate forms on the trunk and proximal limbs and rarely affect the face. In histopathological diagnosis, EAE has typical features, including acute dermal inflammatory infiltrate with abundant eosinophils and lymphocytes around arteries. In spite of no clear treatment, the findings indicated the positive effects of systemic corticosteroid, hydroxychloroquine, and Ultraviolet B therapy along with recurrences. Two patients have been elected in the present study. The first patient was a middle-aged diabetic female with urticarial papules and plaques around the pelvis and proximal thighs that had active borders with improved centers. We started with 400 mg of hydroxychloroquine and 25 mg of prednisone for the patient whose lesions were subsided during the first week. The second consulted patient was a 41-year-old female without a history of previous illness with four months of painful, pruritic, and violaceous plaques on the back of the trunk. In histopathology, dermal inflammatory infiltrate with abundant eosinophils was observed in the dermis. Corticosteroids and hydroxychloroquine were prescribed with the diagnosis of EAE for this patient as well.

A3 CROHN’S DISEASE PROTEOLYTIC MICROBIOTA ENHANCES INFLAMMATION THROUGH PAR2 PATHWAY IN GNOTOBIOTIC MICE

Abstract Background An imbalance in host proteases has been implicated in inflammatory bowel disease (IBD). Recent evidence implicates microbial proteolytic activity (PA) in ulcerative colitis but whether it also plays a role in Crohn’s disease (CD) remains unclear. Purpose We therefore investigated the colitogenic potential and underlying pathways of proteolytic CD microbiota. Method Adult germ-free (GF) C57BL/6 mice were colonized with CD microbiota selected based on high (CD-HPA) or low fecal proteolytic activity (CD-LPA), and from healthy controls with LPA (HC-LPA), after which total fecal proteolytic, elastolytic and mucolytic activity were analyzed in the mice. Microbial community was assessed by 16S rRNA gene sequencing. Immune function and colonic injury were investigated by inflammatory gene expression (NanoString) and histology. Colitis severity and underlying pathways were investigated in C57BL/6, Nucleotide-binding Oligomerization Domain-2 knock-out (Nod2-/-), and Protease-Activated Receptor 2 (PAR2) cleavage resistant mice (R38E-PAR2) subjected to 2% dextran sodium sulfate in drinking water for 5 days followed by 2 days on water. Result(s) Colonization with HC-LPA or CD-LPA lowered baseline fecal proteolytic activity compared with GF mice, which was paralleled by lower acute inflammatory cell infiltrate. CD-HPA further increased proteolytic activity compared with GF mice. Fecal supernatants from CD-LPA or HC-LPA colonized mice had lower in vitro PAR2 cleavage compared to supernatants from GF and CD-HPA colonized mice. Several genes, such as Map kinases, Rhoa, Myd88, and Tollip, were increased in GF mice compared to colonized mice. 18 genes related to inflammation and barrier function (e.g., Mapk2k6, Tnf, Claudin1) were differentially expressed between CD-LPA and CD-HPA. CD-HPA mice had lower alpha diversity, distinct microbial profiles, and higher fecal proteolytic activity compared with CD-LPA. Abundance of several beneficial species (e.g., Akkermansia muciniphilia) was decreased while other taxa were increased (e.g., Hungattella hathewayi) in CD-HPA compared to CD-LPA. H. hathewayi as well as the serine protease K04772 were transcriptionally increased in fecal samples from CD-HPA colonized mice. C57BL/6 and Nod2-/- mice, but not R38E-PAR2 mice, colonized with CD-HPA developed earlier and more severe colitis compared with mice colonized with CD-LPA. Conclusion(s) CD proteolytic microbiota is proinflammatory through a PAR2 pathway. H. hathewayi correlates with the proinflammatory phenotype through the serine protease K04772 in this model. The results support a role of microbial PA in CD, which could constitute a biomarker for identifying patients who would benefit from anti-proteolytic therapies. Disclosure of Interest None Declared

P597 Usefulness of histological monitoring in predicting relapse after de-escalation of thiopurines in Ulcerative Colitis

Abstract Background Thiopurines are useful to maintain remission for ulcerative colitis (UC) and to inhibit immunogenicity in combination with biologics while their long-term use may increase risks of infections and malignancies. Therefore, the risk-benefit balance should be evaluated, and de-escalation needs to be discussed. However, optimal de-escalation strategy such as dosing and monitoring has not been well studied. Methods UC patients in clinical remission (partial Mayo score ≤ 2 and rectal bleeding subscore of 0) who de-escalated thiopurines (dose-reduction or discontinuation) were enrolled. The risk of relapse and changes in Mayo endoscopic subscore (MES) and histological findings after thiopurine de-escalation were retrospectively investigated. The correlation with relapse (treatment escalation (including topical therapy) with the exacerbation of symptoms or rectal bleeding score ≥ 1) was analyzed by logistic regression analysis. Results A total of 69 de-escalation steps (51 dose-reductions and 18 discontinuations) were conducted in 39 patients. The mean duration and dose of thiopurine use were 3.5 years and 66.6mg (converted to azathioprine). Thiopurines were used in combination with biologics in 16 (41.0%). Relapse occurred in 17/69 (24.6%) de-escalation steps (10/17 discontinuations). In 36 de-escalations remaining in remission with available data before and after de-escalations, worsening of MES occurred in 13%, whereas exacerbations of any histopathological finding occurred in 44% (crypt architectural irregularities 25%, chronic inflammatory cell infiltrate 19％, acute inflammatory cell infiltrate 16％, basal plasmacytosis 13%, mucin depletion 13%, crypt abscess 8%). Chronic inflammatory cellular infiltrate (p=0.002), basal plasmacytosis (p=0.008), and acute inflammatory cell infiltrate (p=0.039) at de-escalation were significantly associated with relapse after de-escalation. Nancy Index was also associated with relapse (p=0.011), while MES was not. Conclusion Histological worsening may precede clinical relapse thus may be useful to predict relapse after thiopurine withdrawal.

Not Everything is as it Seems: An Unusual Case of Pyelonephritis

Urinary tract infection is an important cause of hospitalization, morbidity and mortality, being responsible for an important fraction of health expenses. The main risk factors are urine flow obstruction, urinary catheters, immunosuppression and diabetes mellitus. We present a case of pyelonephritis that culminated in nephrectomy, finally unravelling an unexpected diagnosis. A 52-year-old male presented in the emergency department with two weeks of pain in the left iliac fossa that irradiated to the lumbar region and cloudy urine. Lab work revealed severe anaemia (4.9 g/dL), inflammatory markers elevation, leucoerythrocyturia, serum creatinine of 4.33 mg/dL and metabolic acidosis. Computed tomography scan showed a swollen left kidney with a staghorn calculus and intraparenchymal hypodensities. After a failed trial of large spectrum antibiotics, he was submitted to left radical nephrectomy with significant clinical improvement. Gross examination showed a markedly dilated pyelocalicial tree, filled with several staghorn calculi and purulent secretions with associated parenchymal atrophy. Histopathologic evaluation revealed exuberant chronic pyelonephritis with an acute inflammatory infiltrate that extended into the perinephric fat and multiple Schistosoma ova, predominantly calcified. The authors describe the case of a severe pyelonephritis with exuberant clinical and imagiological features and rare microbiological findings, suggesting previous genitourinary Schistosomiasis that predisposed to nephrolithiasis and chronic pyelonephritis.

Synthesis and Evaluation of a Chitosan-Silica-Based Bone Substitute for Tissue Engineering.

Bone defects have prompted the development of biomaterial-based bone substitutes for restoring the affected tissue completely. Although many biomaterials have been designed and evaluated, the combination of properties required in a biomaterial for bone tissue engineering still poses a challenge. In this study, a chitosan-silica-based biocomposite was synthetized, and its physicochemical characteristics and biocompatibility were characterized, with the aim of exploring the advantages and drawbacks of its use in bone tissue engineering. Dynamic light scattering measurements showed that the mean hydrodynamic size of solid silica particles (Sol-Si) was 482 ± 3 nm. Scanning electron microscopy of the biocomposite showed that Sol-Si were homogenously distributed within the chitosan (CS) matrix. The biocomposite swelled rapidly and was observed to have no cytotoxic effect on the [3T3] cell line within 24 h. Biocompatibility was also analyzed in vivo 14 days post-implant using a murine experimental model (Wistar rats). The biocomposite was implanted in the medullary compartment of both tibiae (n = 12). Histologically, no acute inflammatory infiltrate or multinucleated giant cells associated to the biocomposite were observed, indicating good biocompatibility. At the tissue-biocomposite interface, there was new formation of woven bone tissue in close contact with the biocomposite surface (osseointegration). The new bone formation may be attributed to the action of silica. Free silica particles originating from the biocomposite were observed at the tissue-biocomposite interface. According to our results, the biocomposite may act as a template for cellular interactions and extracellular matrix formation, providing a structural support for new bone tissue formation. The CS/Sol-Si biocomposite may act as a Si reservoir, promoting new bone formation. A scaffold with these properties is essential for cell differentiation and filling a bone defect.

RF13 | PMON83 Culture Negative Pituitary Abscesses: A Case Series

Abstract Introduction Pituitary abscesses are rare, representing less than 1% of pituitary lesions. Patients may present with pituitary hypofunction, headache, and/or vision changes, often without systemic or biochemical signs of infection, with diagnosis only made intraoperatively. Cases A 74-year-old man with history of diabetes and coronary artery disease presented with headache and left-eye ptosis. MRI revealed a 1.8 cm hypoenhancing cystic, hemorrhagic sellar mass extending into the left cavernous sinus. Pre-operative labs showed AM cortisol 1.1 ug/dL, testosterone 43 ng/dL (reference range 250-1100), FSH 15.3 mIU/mL, LH 4.5 mIU/mL consistent with adrenal insufficiency and hypogonadism. He underwent transsphenoidal pituitary resection (TSR) during which frank pus was demonstrated after incision into the dura overlying the pituitary. Surgical pathology showed necrosis and granulation-type reaction with acute inflammatory cell infiltrates. Gram stain and methenamine silver stains did not reveal definite micro-organisms while tissue bacterial cultures showed normal skin flora. He remained hemodynamically stable without fevers throughout the hospitalization and was discharged on empiric antibiotics and hydrocortisone. A 74-year-old female with history of a pituitary macroadenoma was admitted for worsening headaches. Labs were consistent with her known history of secondary adrenal insufficiency and hypogonadotropic hypogonadism. Repeat MRI showed characteristics suggestive of hemorrhage within a 1.8 cm intrasellar mass with inhomogeneous and peripheral enhancement after contrast. She underwent TSR and intraoperatively frank pus was encountered. Surgical pathology showed sinonasal mucosa with chronic inflammation. There was no growth in aerobic, fungal, or AFB cultures; anaerobic cultures grew rare commensal bacteria. She was discharged with a course of antibiotics and remains on hydrocortisone. A 42-year-old male presented with headache and was found to have a 2.5 cm sellar mass with rim enhancement elevating and compressing the optic chiasm on MRI. Labs were significant for AM cortisol 4.9 ug/dL and testosterone 8 ng/dL, FSH 0.4 mIU/mL, LH &amp;lt;0.2 mIU/mL consistent with adrenal insufficiency and hypogonadism. He underwent TSR and was found to have purulent debris in the sella. Pathology showed epithelial tissue fragments insufficient for diagnosis, and cultures grew few skin and oropharyngeal contaminants. He was discharged on hydrocortisone with a course of antibiotics. Conclusion We describe three patient cases presenting with headache and varying degrees of hypopituitarism, found to have purulent material emanating from the sella during transsphenoidal resection. None presented with clinical or biochemical systemic signs of infection. MRI imaging was variable, ranging from cystic, hemorrhagic features to peripheral enhancement. Surgical pathology and cultures were unrevealing for a definitive infectious source or other cystic lesion such as Rathke's cleft cyst. This case series demonstrates the potential nonspecific presentation of pituitary abscesses including negative cultures and pathology. It is important to keep this rare diagnosis in the differential for patients presenting with pituitary disease. Presentation: Sunday, June 12, 2022 12:30 p.m. - 12:35 p.m., Monday, June 13, 2022 12:30 p.m. - 2:30 p.m.