Interplay of Cytokines and Chemokines in Aspergillosis.

Aspergillosis is a fungal infection caused by various species of Aspergillus, most notably A. fumigatus. This fungus causes a spectrum of diseases, including allergic bronchopulmonary aspergillosis, aspergilloma, chronic pulmonary aspergillosis, and invasive aspergillosis. The clinical manifestations and severity of aspergillosis can vary depending on individual immune status and the specific species of Aspergillus involved. The recognition of Aspergillus involves pathogen-associated molecular patterns (PAMPs) such as glucan, galactomannan, mannose, and conidial surface proteins. These are recognized by the pathogen recognition receptors present on immune cells such as Toll-like receptors (TLR-1,2,3,4, etc.) and C-type lectins (Dectin-1 and Dectin-2). We discuss the roles of cytokines and pathogen recognition in aspergillosis from both the perspective of human and experimental infection. Several cytokines and chemokines have been implicated in the immune response to Aspergillus infection, including interferon-γ (IFN-γ), tumor necrosis factor-α (TNF-α), CCR4, CCR17, and other interleukins. For example, allergic bronchopulmonary aspergillosis (ABPA) is characterized by Th2 and Th9 cell-type immunity and involves interleukin (IL)-4, IL-5, IL-13, and IL-10. In contrast, it has been observed that invasive aspergillosis involves Th1 and Th17 cell-type immunity via IFN-γ, IL-1, IL-6, and IL-17. These cytokines activate various immune cells and stimulate the production of other immune molecules, such as antimicrobial peptides and reactive oxygen species, which aid in the clearance of the fungal pathogen. Moreover, they help to initiate and coordinate the immune response, recruit immune cells to the site of infection, and promote clearance of the fungus. Insight into the host response from both human and animal studies may aid in understanding the immune response in aspergillosis, possibly leading to harnessing the power of cytokines or cytokine (receptor) antagonists and transforming them into precise immunotherapeutic strategies. This could advance personalized medicine.

Accelerating the understanding of Aspergillus terreus: Epidemiology, physiology, immunology and advances.

Aspergillus species encompass a variety of infections, ranging from invasive aspergillosis to allergic conditions, contingent upon the immune status of the host. In this spectrum, Aspergillus terreus stands out due to its emergence as a notable pathogen and its intrinsic resistance to amphotericin-B. The significance of Aspergillus-associated infections has witnessed a marked increase in the past few decades, particularly with the increasing number of immunocompromised individuals. The exploration of epidemiology, morphological transitions, immunopathology, and novel treatment approaches such as new antifungal drugs (PC945, olorofim) and combinational therapy using antifungal drugs and phytochemicals (Phytochemicals: quercetin, shikonin, artemisinin), also using immunotherapies to modulate immune response has resulted in better outcomes. Furthermore, in the context COVID-19 era and its aftermath, fungal infections have emerged as a substantial challenge for both immunocompromised and immunocompetent individuals. This is attributed to the use of immune-suppressing therapies during COVID-19 infections and the increase in transplant cases. Consequently, this review aims to provide an updated overview encompassing the epidemiology, germination events, immunopathology, and novel drug treatment strategies against Aspergillus terreus-associated infections.

Management of Trochanteric Fractures: Are We NICE Compliant?

INTRODUCTION: The National Institute for Health and Care Excellence (NICE) updated the 2011 hip fracture management guidelines on January 6, 2023, suggesting that clinicians offer sliding hip screws in preference to intramedullary nails for trochanteric fractures above and including the lesser trochanter except reverse oblique fractures. This study aims to assess the compliance of our hospital with the updated guidelines while comparing the results with our performance prior to the update together with the national average. MATERIALS AND METHODS: A retrospective observational study was done to analyse if trochanteric fractures managed surgically were compliant with NICE guidelines. Pathological fractures secondary to tumours and AO/OTA 31A1.1 fractures were excluded. Fractures were classified using the 2018 AO/OTA classification system independently by two authors, with a review from a senior consultant if there was interobserver variation. Group A (n=60) included trochanteric fractures managed surgically three months prior to the update, while Group B (n=46) included patients managed operatively three months following the update. RESULTS: The compliance rates for Group A and Group B were similar at 88.33% and 89.13%, respectively, while the national average was about 67% over the course of six months. DISCUSSION: 31A2 fractures showed higher rates of non-compliance in both groups. Non-compliance was thought to be multifactorial: surgeon bias, inaccurate classification of fractures and a lack of awareness of guidelines. CONCLUSIONS: While there is scope for improvement, district general hospitals can achieve high rates of compliance. Educating and training doctors could help improve compliance.

Molecular Insights Into Development and Virulence Determinants of Aspergilli: A Proteomic Perspective.

Aspergillus species are the major cause of health concern worldwide in immunocompromised individuals. Opportunistic Aspergilli cause invasive to allergic aspergillosis, whereas non-infectious Aspergilli have contributed to understand the biology of eukaryotic organisms and serve as a model organism. Morphotypes of Aspergilli such as conidia or mycelia/hyphae helped them to survive in favorable or unfavorable environmental conditions. These morphotypes contribute to virulence, pathogenicity and invasion into hosts by excreting proteins, enzymes or toxins. Morphological transition of Aspergillus species has been a critical step to infect host or to colonize on food products. Thus, we reviewed proteins from Aspergilli to understand the biological processes, biochemical, and cellular pathways that are involved in transition and morphogenesis. We majorly analyzed proteomic studies on A. fumigatus, A. flavus, A. terreus, and A. niger to gain insight into mechanisms involved in the transition from conidia to mycelia along with the role of secondary metabolites. Proteome analysis of morphotypes of Aspergilli provided information on key biological pathways required to exit conidial dormancy, consortia of virulent factors and mycotoxins during the transition. The application of proteomic approaches has uncovered the biological processes during development as well as intermediates of secondary metabolite biosynthesis pathway. We listed key proteins/ enzymes or toxins at different morphological types of Aspergillus that could be applicable in discovery of novel therapeutic targets or metabolite based diagnostic markers.

Proteome Profile of Aspergillus terreus Conidia at Germinating Stage: Identification of Probable Virulent Factors and Enzymes from Mycotoxin Pathways.

Aspergillus terreus is an emerging opportunistic fungal pathogen that causes invasive aspergillosis in immunocompromised individuals. The main risk group of individuals for this organism is leukopenic patients, individuals having cancers, bone marrow transplant persons and those who have immunological disorders. The lack of early diagnostic marker for A. terreus and intrinsic resistance to Amphotericin B, further limits the successful therapy of A. terreus-associated infections. The germination of inhaled conidia is the key step to establish successful invasion in host tissues or organs. Thus, profiling of expressed proteins during germination of conidia not only shed light on proteins that are involved in invasion or virulence but may also provide early diagnostic markers. We used nanoLC-Q-TOF to study the proteome of germinating conidia (at 16 h time points) of A. terreus. We observed expression of 373 proteins in germinating conidia of A. terreus. A total of 74 proteins were uncharacterized in the database. The expressed proteins were associated with various processes like cell wall modulation, virulence factors and secondary metabolite biosynthesis. The most abundant proteins were associated with protein biosynthesis, carbohydrate metabolism and unknown functions. Among virulent proteins, mitogen-activated protein kinase (hog1) and mitogen-activated protein kinase (mpkC) are key virulent proteins observed in our study. We observed 7 enzymes from terretonin and 10 enzymes from geodin mycotoxin biosynthesis pathway. Interestingly, we observed expression of terrelysin protein, associated with blood cell lysis. Quantitative RT-PCR analysis showed 26-fold increase in transcripts encoding for dihydrogeodin oxidase and 885-fold for terrelysin gene in germinating conidia in comparison to conidia. Further, we propose that terrelysin protein and secondary metabolite such as geodin could be explored as diagnostic marker for A. terreus-associated infections.

In silico Identification of Potential Peptides or Allergen Shot Candidates Against Aspergillus fumigatus.

Aspergillus fumigatus is capable of causing invasive aspergillosis or acute bronchopulmonary aspergillosis, and the current situation is alarming. There are no vaccine or allergen shots available for Aspergillus-induced allergies. Thus, a novel approach in designing of an effective vaccine or allergen shot candidate against A. fumigatus is needed. Using immunoinformatics approaches from the characterized A. fumigatus allergens, we have mapped epitopic regions to predict potential peptides that elicit both Aspergillus-specific T cells and B cell immune response. Experimentally derived immunodominant allergens were retrieved from www.allergen.org. A total of 23 allergenic proteins of A. fumigatus were retrieved. Out of 23 allergenic proteins, 13 of them showed high sequence similarity to both human and mouse counterparts and thus were eliminated from analysis due to possible cross-reactivity. Remaining allergens were subjected to T cell (major histocompatibility complex class I and II alleles) and B cell epitope prediction using immune epitope database analysis resource. Only five allergens have shown a common B and T cell epitopic region between human and mouse. They are Asp f1 {147-156 region (RVIYTYPNKV); Mitogillin}, Asp f2 {5-19 region (LRLAVLLPLAAPLVA); Hypothetical protein}, Asp f5 {305-322 region (LNNYRPSSSSLSFKY); Metalloprotease}, Asp f17 {98-106 region (AANAGGTVY); Hypothetical protein}, and Asp f34 {74-82 region (YIQDGSLYL); PhiA cell wall protein}. The epitopic region from these five allergenic proteins showed potential for development of single peptide- or multipeptide-based vaccine or allergen shots for experimental prioritization.

Nano-LC-Q-TOF Analysis of Proteome Revealed Germination of Aspergillus flavus Conidia is Accompanied by MAPK Signalling and Cell Wall Modulation.

Aspergillus flavus is the second most leading cause of aspergillosis. The ability of A. flavus to adapt within the host environment is crtical for its colonization. Onset of germination of conidia is one of the crucial events; thus, in order to gain insight into A. flavus molecular adaptation while germination, protein profile of A. flavus was obtained. Approximately 82 % of conidia showed germination at 7 h; thus, samples were collected followed by protein extraction and subjected to nLC-Q-TOF mass spectrometer. Q-TOF data were analysed using Protein Lynx Global Services (PLGS 2.2.5) software. A total of 416 proteins were identified from UniProt Aspergillus species database. Orthologues of A. flavus was observed in A. fumigatus, A. niger, A. terreus, A. oryzae, etc. Proteins were further analysed in NCBI database, which showed that 27 proteins of A. flavus are not reported in UniProt and NCBI database. Functional characterization of proteins resulted majorly to cell wall synthesis and degradation, metabolisms (carbohydrate and amino acid metabolism), protein synthesis and degradation. Proteins/enzymes associated with aflatoxin biosynthesis were observed. We also observed Dicer-like proteins 1, 2 and autophagy-related proteins 2, 9, 18, 13, 11, 22. Expression of protein/enzymes associated with MAPK signalling pathway suggests their role during the germination process. Overall, the data present a catalogue of proteins/enzymes involved in the germination of A. flavus conidia and could also be applied to other Aspergillus species.

In silico Analysis Revealed High-risk Single Nucleotide Polymorphisms in Human Pentraxin-3 Gene and their Impact on Innate Immune Response against Microbial Pathogens.

Pentraxin-3 (PTX-3) protein is an evolutionary conserved protein that acts as a soluble pattern-recognition receptor for pathogens and plays important role in innate immune response. It recognizes various pathogens by interacting with extracellular moieties such as glactomannan of conidia (Aspergillus fumigatus), lipopolysaccharide of Pseudomonas aeruginosa, Streptococcus pneumonia and Salmonella typhimurium. Thus, PTX-3 protein helps to clear these pathogens by activating downstream innate immune process. In this study, computational methods were used to analyze various non-synonymous single nucleotide polymorphisms (nsSNPs) in PTX-3 gene. Three different databases were used to retrieve SNP data sets followed by seven different in silico algorithms to screen nsSNPs in PTX-3 gene. Sequence homology based approach was used to identify nsSNPs. Conservation profile of PTX-3 protein amino acid residues were predicted by ConSurf web server. In total, 10 high-risk nsSNPs were identified in pentraxin-domain of PTX-3 gene. Out of these 10 high-risk nsSNPs, 4 were present in the conserved structural and functional residues of the pentraxin-domain, hence, selected for structural analyses. The results showed alteration in the putative structure of pentraxin-domain. Prediction of protein-protein interactions analysis showed association of PTX-3 protein with C1q component of complement pathway. Different functional and structural residues along with various putative phosphorylation sites and evolutionary relationship were also predicted for PTX-3 protein. This is the first extensive computational analyses of pentraxin protein family with nsSNPs and will serve as a valuable resource for future population based studies.

Cytokines induce effector T-helper cells during invasive aspergillosis; what we have learned about T-helper cells?

Invasive aspergillosis caused by Aspergillus species (Aspergillus fumigatus, A. flavus, and A. terreus) is life-threatening infections in immunocompromised patients. Understanding the innate and adaptive immune response particularly T-helper cells (TH-cells) against these Aspergillus species and how the different sub-set of TH-cells are regulated by differentiating cytokines at primary target organ site like lung, kidney and brain is of great significance to human health. This review focuses on presentation of Aspergillus through Antigen presenting cells (APCs) to the naive CD4(+) T-cells in the host. The production of differentiating/effector cytokines that activate following TH-cells, e.g., TH1, TH2, TH9, and TH17 has been reported in association or alone in allergic or invasive aspergillosis. Chemokines (CXCL1, CXCL2, CCL1, and CCL20) and their receptors associated to these TH-cells have also been observed in invasive aspergillosis. Thus, further study of these TH-cells in invasive aspergillosis and other elements of adaptive immune response with Aspergillus species are required in order to have a better understanding of host response for safer and effective therapeutic outcome.

Femoral Revision Arthroplasty for Su Type 3 Supracondylar Periprosthetic Knee Fractures.

Periprosthetic distal femoral fractures can present significant reconstructive challenges when associated with poor bone stock, comminution, or component loosening. Revision arthroplasty with stemmed components or distal femoral replacement arthroplasty often becomes necessary. This retrospective study reviewed the results of femoral revision arthroplasty in 16 knees with acute, extreme distal (Su type 3), supracondylar periprosthetic fractures using cemented, midlevel constrained implants. The mean patient age was 71 years and mean follow-up was 5 years. All fractures united with mean Knee Society scores of 86 and 55, at the last follow-up. All patients returned to preinjury activity level. Complications included one valgus malunion with shortening and one reoperation for functional lateral instability. This treatment modality achieved reliable fracture union and return of function. Moreover, the final salvage option of distal femoral arthroplasty is preserved.

Role of Heat-Shock Proteins in Cellular Function and in the Biology of Fungi.

Stress (biotic or abiotic) is an unfavourable condition for an organism including fungus. To overcome stress, organism expresses heat-shock proteins (Hsps) or chaperons to perform biological function. Hsps are involved in various routine biological processes such as transcription, translation and posttranslational modifications, protein folding, and aggregation and disaggregation of proteins. Thus, it is important to understand holistic role of Hsps in response to stress and other biological conditions in fungi. Hsp104, Hsp70, and Hsp40 are found predominant in replication and Hsp90 is found in transcriptional and posttranscriptional process. Hsp90 and Hsp70 in combination or alone play a major role in morphogenesis and dimorphism. Heat stress in fungi expresses Hsp60, Hsp90, Hsp104, Hsp30, and Hsp10 proteins, whereas expression of Hsp12 protein was observed in response to cold stress. Hsp30, Hsp70, and Hsp90 proteins showed expression in response to pH stress. Osmotic stress is controlled by small heat-shock proteins and Hsp60. Expression of Hsp104 is observed under high pressure conditions. Out of these heat-shock proteins, Hsp90 has been predicted as a potential antifungal target due to its role in morphogenesis. Thus, current review focuses on role of Hsps in fungi during morphogenesis and various stress conditions (temperature, pH, and osmotic pressure) and in antifungal drug tolerance.

Severe persistent synovitis after cobalt-chromium total knee arthroplasty requiring revision.

Implant-related hypersensitivity is a well-established cause of failure after total hip arthroplasty but is a rare complication after total knee arthroplasty (TKA). It remains a relatively unpredictable and poorly understood cause of implant-related failure. This article describes 5 patients (6 knees) who presented with persistent pain and hypertrophic synovitis after TKA using a cobalt-chromium component. Extensive perioperative workup, including white blood cell count, erythrocyte sedimentation rate, C-reactive protein, joint aspiration, and intraoperative cultures, ruled out infection as a cause of the symptoms. All knees demonstrated appropriate ligamentous balance and were well aligned, with all components noted to be well fixed at revision. In all patients, the clinical condition improved dramatically after revision to zirconium femoral and titanium metal-backed tibial components. Pain and functional outcome scores improved in all patients. Intraoperative histopathology revealed a thickened synovium with either a predominantly lymphocytic or histiocytic monocellular response. Final pathology confirmed that no infection was present in any patient. The goal of TKA is to produce a well-performing, pain-free joint. When patients present with recurrent pain and synovitis after TKA, infection must be excluded. When infection and instability have been excluded, metal hypersensitivity should be considered as a cause of primary TKA failure. In these patients, revision to a zirconium femoral component can provide predictable and effective clinical improvement.

Management of failed trochanteric fracture fixation with cementless modular hip arthroplasty using a distally fixing stem.

Failure of internal fixation of intertrochanteric fractures is associated with delayed union or malunion resulting in persistent pain and diminished function. We evaluated 15 elderly patients treated with a tapered, fluted, modular, distally fixing cementless stem. At an average follow-up of 2.86 years, mean Harris hip score improved from 35.90 preoperatively to 83.01 (P < .01). Fourteen stems had stable bony on growth, and one stem was loose. Distal fixation with a tapered, fluted, modular cementless stem allows stable fixation with good functional outcome in a reproducible fashion in this challenging cohort of patients.

Accuracy of diagnostic injection in differentiating source of atypical hip pain.

It is not uncommon to encounter patients with atypical hip or lower extremity pain, ill-defined clinicoradiological features, and concomitant hip and lumbar spine arthritis. The purpose of this study is to present our experience using the response resulting from a combined anesthetic-steroid hip injection for treatment selection in these patients. A retrospective analysis of 204 consecutive diagnostic hip injections was undertaken. Patient charts were scrutinized for outcomes of injection and treatment. Our findings suggest that the relief of symptoms following injection of local anesthetic and steroid into the hip joint has a sensitivity of 91.5%, specificity and positive predictive value of 100%, and negative predictive value of 84.6% for response to total hip arthroplasty. We thereby believe that this is a reliable test with low morbidity and can predict the potential benefit of total hip arthroplasty in this diagnostically challenging group of patients.

Spontaneous displacement of olecranon fracture through geode salvaged by elbow replacement.

We present a case of pathological fracture of olecranon through a giant geode. Fracture was initially undisplaced and was treated conservatively. It later progressed to a transolecranon dislocation as a result of a pseudarthrosis at the fracture site. The patient presented 4 years later when she developed symptoms of ulnar nerve palsy. She was treated by a total elbow arthroplasty with ulnar nerve transposition. The current report highlights this unusual case and reviews the relevant literature.