Search Results (519)

Background/Objectives: Mycobacterium abscessus is an opportunistic pathogen causing infections mainly in patients with immunosuppression and chronic pulmonary pathologies. Extended treatment periods are needed to tackle this pathogen, bacterial eradication is rare, and recurrence can take place with time. New alternative treatments are being investigated, such as bacteriophage therapy. This work describes the characterization of the mycobacteriophage P3MA, showing its ability to infect clinical and standard M. abscessus strains. Methods: Phylogenetic analysis, electron microscopy, growth curves, biofilm assays, checkerboard, and granuloma-like medium studies were performed. Results: P3MA inhibited the growth of clinical samples in both planktonic and biofilm states as well as in a granuloma-like model. The study of the interaction with antibiotics revealed that P3MA exhibited an antagonistic effect combined with clarithromycin, indifference with amikacin, and synergy with imipenem. Conclusions: All these results suggest that, after genetic engineering, P3MA could be a promising candidate for phage therapy in combination with imipenem, including lung infections. Full article

Crohn’s disease is a chronic inflammation affecting the gastrointestinal tract. To date, patients are commonly treated with corticosteroids or more aggressive biologics for high-risk subjects. Stem Cell Educator therapy has been successfully utilized to treat patients with type 1 diabetes and other autoimmune conditions. A 78-year-old patient with long-standing Crohn’s disease received one treatment with the Stem Cell Educator therapy, followed by clinical, radiographic, pathological examinations and immune marker testing by flow cytometry. After the treatment with Stem Cell Educator therapy, the patient’s clinical symptoms were quickly improved with normal bowel movements, without abdominal pain or rectal bleeding. Flow cytometry analysis revealed a marked decline in inflammatory markers, such as the percentage of monocyte/macrophage-associated cytokine interleukin-1 beta (IL-1β)⁺ cells, which reduced from 94.98% at the baseline to 18.21%, and down-regulation of the percentage of chemokine CXCL16⁺ cells from 91.92% at baseline to 42.58% at 2-month follow-up. Pathologic examination of the biopsy specimens from colonoscopy five weeks and six months post-treatment showed ileal mucosa with no specific abnormality and no significant inflammation or villous atrophy; no granulomas were identified. A follow-up CT scan four and one-half months post-treatment showed no evidence of the previously seen stenosis of the ilio-colonic anastomosis with proximal dilatation. Stem Cell Educator therapy markedly reduced inflammation in the subject with Crohn’s disease, leading to durable clinical, immunological, radiographic, and pathological improvements. Full article

We performed a diagnostic disease investigation on a wild smallmouth bass (Micropterus dolomieu) with skin ulcers that was collected from Lake Oahe, South Dakota, following reports from anglers of multiple fish with similar lesions. Gross and histologic lesions of ulcerative dermatitis, myositis, and lymphocytolysis within the spleen and kidneys were consistent with largemouth bass virus (LMBV) infection. LMBV was detected by conventional PCR in samples of a skin ulcer, and the complete genome sequence of the LMBV (99,184 bp) was determined from a virus isolate obtained from a homogenized skin sample. A maximum likelihood (ML) phylogenetic analysis based on the major capsid protein (MCP) gene alignment supported the LMBV isolate (LMBV-SD-2023) as a member of the species Ranavirus micropterus1, branching within the subclade of LMBV isolates recovered from North American largemouth (Micropterus salmoides) and smallmouth bass. This is the first detection of LMBV in wild smallmouth bass from South Dakota. The ultrastructure of the LMBV isolate exhibited the expected icosahedral shape of virions budding from cellular membranes. Viral nucleic acid in infected cells was visualized via in situ hybridization (ISH) within dermal granulomas, localized predominantly at the margin of epithelioid macrophages and central necrosis. Further sampling is needed to determine the geographic distribution, affected populations, and evolutionary relationship between isolates of LMBV. Full article

The respiratory consequences of brachycephalic airway obstructive syndrome (BAOS) are well known; however, brachycephalic dogs may also present with alimentary tract signs. The electronic medical records of 176 French bulldogs with BAOS were reviewed to classify the gastrointestinal endoscopic findings, and to evaluate the associations between clinicopathological data, endoscopic respiratory, and digestive findings. Dogs that did not undergo endoscopic examination of both airways and the upper digestive tract were excluded. The type and frequency of respiratory and digestive signs were assessed according to a previously described grading system, in addition to gastrointestinal histopathological findings. Video documentation was reviewed to assign a score to each gastrointestinal endoscopic finding (EGF) and to obtain a total EGF score. All dogs showed at least one EGF. The median total EGF score was 5 (range 1–9). A significant association between the score from digestive signs and the total EGF score was found. In addition, laryngeal granulomas were significantly associated with regurgitation. No associations were found between gastrointestinal histopathological findings and the scores from respiratory or digestive signs. Overall, gastrointestinal endoscopic findings and laryngeal granulomas are common among French bulldogs with BAOS. Therefore, a systematic endoscopic approach to alimentary signs is desirable to determine the most appropriate treatment. Full article

Background/Objectives: Osteonecrosis of the femoral head (ONFH) is a common condition in hip surgery, which is characterized by the death of bone cells due to disruption of the blood supply and ultimately irreversible destruction of the hip joint. As a result of the COVID-19 pandemic, a significant increase in the incidence of ONFH has been identified. To better understand the pathogenesis of ONFH in the context of COVID-19, our research aimed to determine pathomorphological changes in articular tissues specific to post-COVID-19 ONFH. Methods: Using morphological, morphometric, and statistical methods, the femoral heads after hip arthroplasty were retrospectively studied in patients with post-COVID-19 ONFH (n = 41) compared to a non-COVID-19 group of patients (n = 47). Results: Our results revealed that the key morphofunctional biomarkers of post-COVID-19 ONFH were clusters of mast cells, extensive areas of fibrosis, numerous arterial and venous thrombi, and giant cell granulomas. The potential relationship of those morphological features with the action of the SARS-CoV-2 coronavirus was discussed. Conclusions: Mast cells have been proposed as the leading players that may trigger the main molecular and cellular mechanisms in the development of post-COVID-19 ONFH and can be considered a diagnostic sign of the disease. Full article

Mycobacterium tuberculosis—an acid-fast staining bacterium—is a serious global health challenge that can have both short-term and long-term complications. Although the immune response helps trap the infection, it can also cause necrosis and calcification, leading to lung tissue damage. Calcification is a known outcome of chronic granuloma evolution in TB. Multiple pathways contribute to fibrosis and calcification; some examples are IL-1β, TGF-β, and TNF-α. Current antifibrotic drugs, such as nintedanib and pirfenidone, are effective but may increase the risk of latent tuberculosis reactivation in certain patients. Experimental therapies such as artemisinin derivatives have shown promise in preclinical TB fibrosis models, while cell-based therapies like bone marrow-derived mononuclear cells are also under early investigation for dual antifibrotic and immunomodulatory effects. This literature review will explore recent studies on the pathogenesis of M. tuberculosis, the mechanisms underlying calcification in granuloma formation, and subsequent complications of the disease process. Full article

Background and Clinical Significance: Disseminated nocardiosis is a rare, life-threatening infection, often misdiagnosed due to its resemblance to other conditions. Case Presentation: A 62-year-old post-renal transplant patient presented with pulmonary, hepatic, and pancreatic lesions. Despite multiple negative bacterial cultures, a histopathological examination of the liver revealed necrotizing granulomas with filamentous microorganisms, ultimately identified as Nocardia. Conclusions: This case highlights diagnostic challenges and the importance of integrating microbiological, pathological, and radiographical findings to manage and diagnose disseminated nocardiosis infections in immunocompromised individuals. Full article

Nocardia spp. are opportunistic pathogens of humans, domestic animals, and wildlife that can cause high levels of morbidity and mortality. Here, we present a unique case of nocardial airsacculitis in a free-ranging mallard (Anas platyrhynchos) from Arizona, USA, and compare it to the hosts, geographic distribution, diagnostic methodology, and infection site of known nocardiosis cases in birds. A gross necropsy, histopathology, and bacterial culture were performed. There were no gross findings associated with the nocardiosis. Histopathology showed multiple granulomas expanding the air sac with intralesional filamentous bacteria that were Grocott’s methenamine silver-positive, Fite–Faraco and Ziehl–Neelsen acid-fast, positive with the Periodic acid–Schiff reaction, and variably Gram-positive. The organism was isolated in culture and identified as Nocardia cyriacigeorgica based on the sequencing of a 463 bp portion of the 16S rRNA gene. While reports of nocardiosis in the class Aves are rare and some are possibly misdiagnosed due to limited diagnostics, cases are reported globally, sometimes resulting in epizootics. More information is needed to understand whether immunosuppression plays a role in disease development in birds. Known to be an emerging pathogen in humans, N. cyriacigeorgica can be considered as a differential diagnosis for pulmonary and potentially cutaneous or disseminated infections in birds. Full article

Background: Sarcoidosis is a multisystem inflammatory disease characterized by the immune-mediated formation of non-necrotizing epithelioid granulomas. Several commonly used medications can induce similar granulomatous reactions, known as drug-induced sarcoid-like reactions (DISRs), which closely mimic sarcoidosis. Despite their specificity in targeting molecular pathways, certain therapies—particularly targeted treatments—have increasingly been linked to DISRs. Methods: This narrative review was based on a PubMed search using the terms “SARCOID LIKE REACTION” and “DRUG”. A cross-check was performed with “SARCOID” combined with each identified drug to identify misclassified cases. Drugs with limited evidence or weak pathogenetic plausibility were excluded, leaving only molecularly targeted therapies for consideration. Sources included case reports, case series, and reviews selected based on their clinical and scientific relevance, without any restrictions on time or language. Results: In light of the available data, five main pharmacological groups were found to be associated to DISR: immune checkpoint inhibitors, TNF-α antagonists, BRAF inhibitors, monoclonal antibodies, and miscellaneous agents. Each group has distinct mechanisms of action and clinical indications, which likely affect the frequency, presentation, and timing of DISRs. Conclusions: Diagnosing DISRs is challenging, and a structured approach is crucial for differentiating them from other conditions. To support clinicians, we propose a diagnostic algorithm to guide decision-making in suspected cases. Management should be individualized, as most DISRs either resolve spontaneously or improve after the discontinuation of the causative drug. Important factors influencing therapeutic decisions include the severity of the underlying disease, the availability of alternative treatments, and the extent of DISR manifestations. Full article

Vaccination remains the most cost-effective way to control clinical paratuberculosis in dairy herds, but its effect on the immune response at the intestine have been poorly characterized. The aim of this study was to evaluate the expression of toll-like receptor (TLR)-1, TLR2, TLR4, TLR9, interferon (IFN)-γ, inducible nitric oxide synthase (iNOS) and cluster of differentiation (CD)-204 in calves vaccinated with Silirum^® and then experimentally infected with paratuberculosis, using immunohistochemical techniques. Samples of the injection-site granuloma, scapular lymph node, intestine and mesenteric lymph nodes were studied. Lesions were classified as focal, multifocal and diffuse paucibacillary (lymphocytic). The immunolabeling for TLR1, TLR2, TLR4 and IFN-γ was assessed according to the number of immunolabeled cells, while TLR9, iNOS and CD204 immunolabeling in the lesions was evaluated using a histological score (H-score). Vaccinated calves with focal forms showed a significant increase in the number of macrophages immunolabeled TLR2 at the intestine and in the H-score values for iNOS in the granulomas. A greater immunolabeling of TLR2 and IFN-γ was detected at the injection-site granuloma. Animals with multifocal lesions, regardless of the vaccination status, showed lower numbers of TLR2+ macrophages and higher H-score values for CD204 in the granulomas. Thus, the protection conferred by the Silirum^® vaccine is associated with an enhanced immunological response in the intestine. Full article

Amelanotic melanocytic nevi of the oral cavity are uncommon lesions that often present a diagnostic challenge for clinicians, primarily due to their nonspecific clinical appearance and the broad spectrum of possible differential diagnoses. These lesions can mimic a variety of benign and malignant conditions, requiring precise histopathological confirmation. The primary objective of this article is to present a comprehensive case report—tracing the course from initial presentation through diagnostic workup to final diagnosis—and to provide an overview of the current literature on oral amelanotic melanocytic nevi. We report the case of a 27-year-old female who presented with a small, exophytic mass located in the anterior mandibular gingival region. The lesion was asymptomatic and lacked pigmentation, adding to the diagnostic uncertainty. A range of differential diagnoses was considered, including pyogenic granuloma, peripheral ossifying fibroma, and squamous cell carcinoma. Due to the lesion’s limited size and accessibility, an excisional biopsy was performed under local anesthesia. Histopathological examination revealed an amelanotic melanocytic nevus, a rare variant characterized by the absence of melanin pigment, further complicating the clinical impression. The diagnosis was confirmed through immunohistochemical staining, which demonstrated melanocytic markers consistent with a nevus. The patient was followed up with for six months postoperatively, with no evidence of recurrence or malignant transformation. This case highlights the critical role of biopsy in achieving a definitive diagnosis, especially in lesions with atypical clinical presentations. It also underscores the importance of considering amelanotic melanocytic nevi in the differential diagnosis of nonpigmented oral lesions, as well as maintaining vigilance regarding the rare possibility of amelanotic melanoma. Full article

Background/Objectives: Cell-based therapies have become increasingly important in the treatment of cancers and inflammatory diseases; however, therapies utilizing monocyte–macrophage lineage cells remain relatively underexplored. Non-invasive cell tracking allows a better understanding of the fate of such cells, which is essential for leveraging their therapeutic potential. Here, we employed a Zirconium-89 (⁸⁹Zr)-oxine cell labeling method to compare the trafficking of monocytes and macrophages in vivo. Methods: Mouse bone marrow-derived monocytes and macrophages were each labeled with ⁸⁹Zr-oxine and evaluated for their viability, radioactivity retention, chemotaxis, and phagocytic function in vitro. Labeled cells were intravenously administered to healthy mice and to murine models of granuloma and syngeneic tumors. Cell migration was monitored using microPET/CT, while cell recruitment to the lesions was further assessed via ex vivo biodistribution and flow cytometry. Results: Labeled cells exhibited similar survival and proliferation to unlabeled cells for up to 7 days in culture. While both maintained phagocytic function, monocytes showed higher CCL2-driven chemotaxis compared to macrophages. ⁸⁹Zr-oxine PET revealed initial cell accumulation in the lungs, followed by their homing to the liver and spleen within 2–24 h, persisting through the 5-day observation period. Notably, monocytes trafficked to the liver and spleen more rapidly than macrophages. In both inflammation and cancer models, monocytes demonstrated higher accumulation at the lesion sites compared to macrophages. Conclusions: This study demonstrates the usefulness of ⁸⁹Zr-oxine PET in tracking monocyte–macrophage lineage cells, highlighting their distinct migration patterns and providing insights that could advance monocyte-centered cell therapies. Full article

A 10-year-old male neutered British Shorthair cat with diabetes mellitus presented with an acute onset of unilateral swelling, erythema, alopecia and coalescing ulcerations of the face and periocular skin. Initial clinical differential diagnoses were trauma, infections (including feline respiratory viruses), arthropod bites, and eosinophilic dermatoses such as eosinophilic granuloma complex, mosquito-bite hypersensitivity and cutaneous adverse drug reaction. Histopathology revealed fulminant furunculosis with abundant eosinophils and vasculitis. Initial topical glucocorticoid treatment partially improved the clinical signs but severely raised serum glucose levels. As a result, systemic glucocorticoids and ciclosporin were not considered optimal treatments, and the off-label and short-term use of oclacitinib was chosen with the owner’s informed consent. This treatment induced fast remission of clinical signs with no recurrence for 17 months. Secondary fusion of the eyelids caused by cicatrization was surgically reconstructed to restore full function. Full article

Previous studies showed a potent anti-inflammatory activity of Solanum tuberosum L. polysaccharide (STP), which inhibited pro-inflammatory cytokines and stimulated anti-inflammatory ones in peptic ulcer models. Thus, the main goal of this study was to find out the molecular background of such activity and possible applications in different anti-inflammatory models. This study investigated the anti-inflammatory potential of the polysaccharide STP using model of LPS-induced inflammation in THP-1 macrophage-like cells (on the expression of IL1B, IL6, IL10, TNF, NFKB1, BCL2, NRF2, and BAX—genes involved in the regulation of inflammatory processes and oxidative stress), rat pocket granuloma, and carrageenan-induced oedema models. STP significantly reduced oedema volume, exhibiting a comparable anti-exudative effect to ibuprofen and surpassing the control group. The anti-inflammatory mechanism of STP extends beyond suppression of proinflammatory cytokine (IL1B, IL6, TNF) expression, as it also activates cellular defence mechanisms (NRF2, BCL2, BAX) and expression of anti-inflammatory cytokine (IL10). This complex, multifactorial action suggests that STP may possess significant therapeutic value for inflammatory conditions. The combined functional and molecular findings underscore STP’s potent anti-inflammatory properties, comparable to ibuprofen. Full article

The liver of fish is an essential metabolic organ that also serves an immune regulatory role. In this study, we constructed a model of largemouth bass (Micropterus salmoides) infected with Nocardia seriolae by injection to explore the immune and antioxidant functions of the liver. The results showed that N. seriolae infection caused severe pathological changes in the liver, including cell necrosis, granuloma formation, and leukocyte infiltration. The level of mRNA expression of immune-related genes in the liver was significantly increased 2 days post-infection. Moreover, the combined analysis of transcriptome and metabolome showed that N. seriolae infection markedly affected liver metabolism, including glutathione metabolism, arginine and proline metabolism, arachidonic acid metabolism, as well as starch and sucrose metabolism. Additionally, multiple key biomarkers were identified as involved in regulating responses to N. seriolae infection, including arginine, glutathione, gpx, GST, PLA2G, GAA, and PYG. To further elucidate the regulatory effects of arginine on the immune and antioxidant processes in the liver, primary hepatocytes were isolated and cultured. The results demonstrated that arginine supplementation significantly reduced the expression of LPS-induced apoptosis-related genes (bax, cas3, cas8, and cas9) by up to 50% while increasing the expression of antioxidant genes (gpx, GST) by up to 700% at 24 h. Through the analysis of metabolic changes and immune responses in the liver following N. seriolae infection, combined with in-vitro experiments, this study elucidated the anti-apoptotic and antioxidant effects of arginine, revealing the immune response mechanisms in fish liver and laying the groundwork for using nutritional strategies to improve fish health. Full article