Peripheral Infection Research Articles

Preface to the special issue "Neuroimmunology".

This preface introduces the Special Issue on Neuroimmunology in the Journal of Neurochemistry. The basis of neuroimmunology is to understand functional interactions between cells of the immune system and the central nervous system (CNS). These cells communicate across systems because they share signaling molecules and corresponding receptors. Moreover, this cell signaling allows for dynamic bidirectional communication between the immune system and the brain both within the CNS proper as well as across peripheral organs. Because of this, Neuroimmunology intersects with many biological processes including immunity, behavior, endocrinology, metabolism, and pathology. Understanding neuroimmune interactions that influence CNS homeostasis is especially relevant in health and disease. This special issue comprises of 14 articles, representing 9 review articles and 5 original articles, covering the roles of neuroimmunology relevant to CNS injury, CNS & peripheral infections, cancer, Alzheimer's disease, and COVID-19. Thus, these articles highlight different aspects of neuroimmunology and signaling, and represent progress in understanding the consequences of inflammation on key communication pathways between the immune system and the brains.

Peripherally-restricted recurrent infection by engineered E. coli strain modulates hippocampal proteome promoting memory impairments in a rat model

Commensal bacteria that breach endothelial barrier has been reported to induce low grade chronic inflammation producing disease symptoms in major peripheral tissues. In this study, we investigated the role of genetically modified cellular invasive form of commensal E. coli K12 (SK3842) in cognitive impairment. Low-grade systemic infection model was developed using recurring peripheral inoculation of live bacteria in Wistar rats. To examine memory parameters, Novel object recognition test and Radial arm maze test were performed. Differential protein expression profiling of rat hippocampus was carried out using LC-MS/MS and subsequently quantified using SWATH. HBA1/2, NEFH, PFN1 and ATP5d were chosen for validation using quantitative RT-PCR. Results showed drastic decline in Recognition memory of the SK3842 infected rats. Reference and Working Memory of the infected group were also significantly reduced in comparison to control group. Proteome analysis using LC-MS/MS coupled with SWATH revealed differential expression of key proteins that are crucial for the maintenance of various neurological functions. Moreover, expression of NEFH and PFN1transcripts were found to be in line with the proteomics data. Protein interaction network of these validated proteins generated by STRING database converged to RhoA protein. Thus, the present study establishes an association between peripheral infection of a hippocampal protein network dysregulation and overall memory decline.

GAS6 as a potential target to alleviate neuroinflammation during Japanese encephalitis in mouse models

Viral encephalitis is characterized by inflammation of the brain parenchyma caused by a variety of viruses, among which the Japanese encephalitis (JE) virus (JEV) is a typical representative arbovirus. Neuronal death, neuroinflammation, and breakdown of the blood brain barrier (BBB) constitute vicious circles of JE progression. Currently, there is no effective therapy to prevent this damage. Growth arrest specific gene 6 (GAS6) is a secreted growth factor that binds to the TYRO3, AXL, and MERTK (TAM) family of receptor tyrosine kinases and has been demonstrated to participate in neuroprotection and suppression of inflammation in many central nervous system (CNS) diseases which has great potential for JE intervention. In this study, we found that GAS6 expression in the brain was decreased and was reversely correlated with viral load and neuronal loss. Mice with GAS6/TAM signalling deficiency showed higher mortality and accelerated neuroinflammation during peripheral JEV infection, accompanied by BBB breakdown. GAS6 directly promoted the expression of tight junction proteins in bEnd.3 cells and strengthened BBB integrity, partly via AXL. Mice administered GAS6 were more resistant to JEV infection due to increased BBB integrity, as well as decreased viral load and neuroinflammation. Thus, targeted GAS6 delivery may represent a strategy for the prevention and treatment of JE especially in patients with impaired BBB.

The clinical application value of multi-site mNGS detection of patients with sepsis in intensive care units

BackgroundSepsis remains a leading cause of mortality in intensive care units, and rapid and accurate pathogen detection is crucial for effective treatment. This study evaluated the clinical application of multi-site metagenomic next-generation sequencing (mNGS) for the diagnosis of sepsis, comparing its performance against conventional methods.MethodsA retrospective analysis was conducted on 69 patients with sepsis consecutively admitted to the Department of Intensive Care Medicine, Meizhou People’s Hospital. Samples of peripheral blood and infection sites were collected for mNGS and conventional method tests to compare the positive rate of mNGS and traditional pathogen detection methods and the distribution of pathogens. The methods used in this study included a comprehensive analysis of pathogen consistency between peripheral blood and infection site samples. Additionally, the correlation between the pathogens detected and clinical outcomes was investigated.ResultsOf the patients with sepsis, 57.97% experienced dyspnea, and 65.2% had underlying diseases, with hypertension being the most common. mNGS demonstrated a significantly higher pathogen detection rate (88%) compared to the conventional method tests (26%). The pathogen consistency rate was 60% between plasma and bronchoalveolar lavage fluid samples, and that of plasma and local body fluid samples was 63%. The most frequently detected pathogens were gram-negative bacteria, and Klebsiella pneumonia. There were no significant differences in the clinical features between the pathogens.ConclusionmNGS is significantly superior to conventional methods in pathogen detection. There was a notable high pathogen consistency detection between blood and local body fluid samples, supporting the clinical relevance of mNGS. This study highlights the superiority of mNGS in detecting a broad spectrum of pathogens quickly and accurately.Trial registrationNot applicable.

Alternating gemcitabine plus nab-paclitaxel and gemcitabine alone versus continuous gemcitabine plus nab-paclitaxel after induction treatment of metastatic pancreatic cancer (ALPACA): a multicentre, randomised, open-label, phase 2 trial

A standardised dose-reduction strategy has not been established for the widely used gemcitabine plus nab-paclitaxel regimen in patients with metastatic pancreatic ductal adenocarcinoma. We aimed to investigate the efficacy and tolerability of alternating treatment cycles of nab-paclitaxel-gemcitabine combination therapy and gemcitabine alone versus continuous treatment with the nab-paclitaxel-gemcitabine combination. ALPACA was a randomised, open-label, phase 2 trial conducted at 29 study centres across Germany. Patients aged 18 years or older with a histologically or cytologically confirmed diagnosis of metastatic pancreatic ductal adenocarcinoma who had not been previously treated for advanced disease were enrolled. After an induction phase with three cycles of nab-paclitaxel-gemcitabine combination therapy (nab-paclitaxel 125 mg/m2 and gemcitabine 1000 mg/m2 administered intravenously on days 1, 8, and 15 of each 28-day cycle), patients were randomly assigned (1:1) by stratified permuted block randomisation either to continue treatment with standard nab-paclitaxel-gemcitabine or to receive alternating cycles of nab-paclitaxel-gemcitabine and gemcitabine alone. Patients and investigators were not masked to treatment allocation. Randomisation was done centrally by the study statistician using a computer-generated randomisation list, and was stratified by Karnofsky Performance Status and presence of liver metastases. The primary endpoint was the derivation of an unbiased point estimate and an associated confidence interval with a confidence coefficient of 80% for the hazard ratio (HR) for overall survival after randomisation, without testing a specific hypothesis, analysed by intention to treat in all patients who started randomised treatment. Safety was analysed according to treatment received. This trial is registered with ClinicalTrials.gov, NCT02564146, and is completed. Between May 27, 2016, and May 27, 2021, 325 patients were enrolled. Following three cycles of induction treatment, 174 patients were randomly assigned: 85 to continue receiving standard nab-paclitaxel-gemcitabine, of whom 79 started treatment, and 89 to the alternating treatment schedule, of whom 88 started treatment. Of the 167 patients who started randomised treatment, 88 (53%) were female and 79 (47%) were male. Median overall survival after randomisation was 10·4 months (80% CI 9·2-12·0) in the group that received standard treatment and 10·5 months (10·2-11·1) in the group that received alternating treatment (HR 0·90, 80% CI 0·72-1·13; p=0·56). The most common adverse events of any grade were peripheral neuropathy (59 [74%] of 80 patients in the continuous treatment group vs 53 [62%] of 85 patients in the alternating treatment group) and fatigue (43 [54%] vs 44 [52%]). Treatment-emergent serious adverse events after randomisation occurred in 40 (50%) patients in the continuous treatment group and in 28 (33%) in the alternating treatment group. Fewer treatment-emergent adverse events of grade 3 or higher occurred in patients treated with alternating cycles compared with those receiving standard therapy, especially for peripheral neuropathy (17 [21%] patients in the continuous treatment group vs 12 [14%] in the alternating treatment group) and infections (16 [20%] vs nine [11%]). There were two treatment-related deaths after randomisation, both in the continuous treatment group (one multiple organ dysfunction syndrome, not treated after randomisation, and one interstitial lung disease). Our findings suggest that a dose-reduced regimen with alternating cycles of nab-paclitaxel-gemcitabine and gemcitabine alone after three induction cycles is associated with similar overall survival to that for standard treatment with nab-paclitaxel-gemcitabine, but with improved tolerability. We therefore propose that a switch to the alternating schedule could be considered in a clinical setting for patients with metastatic pancreatic cancer who have at least stable disease after three cycles of nab-paclitaxel-gemcitabine treatment. Celgene/Bristol Myers Squibb.

MSKI-RADS: An MRI-based Musculoskeletal Infection Reporting and Data System for the Diagnosis of Extremity Infections.

Background Current terms used to describe the MRI findings for musculoskeletal infections are nonspecific and inconsistent. Purpose To develop and validate an MRI-based musculoskeletal infection classification and scoring system. Materials and Methods In this retrospective cross-sectional internal validation study, a Musculoskeletal Infection Reporting and Data System (MSKI-RADS) was designed. Adult patients with radiographs and MRI scans of suspected extremity infections with a known reference standard obtained between June 2015 and May 2019 were included. The scoring categories were as follows: 0, incomplete imaging; I, negative for infection; II, superficial soft-tissue infection; III, deeper soft-tissue infection; IV, possible osteomyelitis (OM); V, highly suggestive of OM and/or septic arthritis; VI, known OM; and NOS (not otherwise specified), nonspecific bone lesions. Interreader agreement for 20 radiologists from 13 institutions (intraclass correlation coefficient [ICC]) and true-positive rates of MSKI-RADS were calculated and the accuracy of final diagnoses rendered by the readers was compared using generalized estimating equations for clustered data. Results Among paired radiographs and MRI scans from 208 patients (133 male, 75 female; mean age, 55 years ± 13 [SD]), 20 were category I; 34, II; 35, III; 30, IV; 35, V; 18, VI; and 36, NOS. Moderate interreader agreement was observed among the 20 readers (ICC, 0.70; 95% CI: 0.66, 0.75). There was no evidence of correlation between reader experience and overall accuracy (P = .94). The highest true-positive rate was for MSKI-RADS I and NOS at 88.7% (95% CI: 84.6, 91.7). The true-positive rate was 73% (95% CI: 63, 80) for MSKI-RADS V. Overall reader accuracy using MSKI-RADS across all patients was 65% ± 5, higher than final reader diagnoses at 55% ± 7 (P < .001). Conclusion MSKI-RADS is a valid system for standardized terminology and recommended management of imaging findings of peripheral extremity infections across various musculoskeletal-fellowship-trained reader experience levels. © RSNA, 2024 Supplemental material is available for this article. See also the editorial by Schweitzer in this issue.

Research Progress on the Risk and Prevention Measures of Peripheral Arterial Catheter Infection in ICU Patients

Peripheral arterial catheter (PAC) is an important assistant method in the treatment of critical patients. However, the related infection risk is significantly underestimated, especially the occurrence of catheter-related bloodstream infections (CRBSI), which also affects the prognosis of patients severely. After literature review, this paper summarized the risk of PAC related infections, PAC retention and maintenance infection prevention measures, and existing problems in PAC related infection research. The progress of intervention measures was collected such as strict adherence to aseptic principles, use of maximum aseptic barrier, selection of arterial puncture site, ultrasound assisted visual puncture, combination of patch and assistant fixation device, shortening of catheter retention period, use of chlorhexidine patch, and regular education and training, to provide scientific and actionable practical guidance for the prevention and control of PAC related infections in clinical practice.

Insertion site and risk of peripheral intravenous catheter colonization and/or local infection: a post hoc analysis of the CLEAN 3 study including more than 800 catheters

AimAlthough uncommon, infections associated with peripheral intravenous catheters (PIVCs) may be responsible for severe life-threatening complications and increase healthcare costs. Few data are available on the relationship between PIVC insertion site and risk of infectious complications.MethodsWe performed a post hoc analysis of the CLEAN 3 database, a randomized 2 × 2 factorial study comparing two skin disinfection procedures (2% chlorhexidine-alcohol or 5% povidone iodine-alcohol) and two types of medical devices (innovative or standard) in 989 adults patients requiring PIVC insertion before admission to a medical ward. Insertion sites were grouped into five areas: hand, wrist, forearm, cubital fossa and upper arm. We evaluated the risk of risk of PIVC colonization (i.e., tip culture eluate in broth showing at least one microorganism in a concentration of at least 1000 Colony Forming Units per mL) and/or local infection (i.e., organisms growing from purulent discharge at PIVC insertion site with no evidence of associated bloodstream infection), and the risk of positive PIVC tip culture (i.e., PIVC-tip culture eluate in broth showing at least one microorganism regardless of its amount) using multivariate Cox models.ResultsEight hundred twenty three PIVCs with known insertion site and sent to the laboratory for quantitative culture were included. After adjustment for confounding factors, PIVC insertion at the cubital fossa or wrist was associated with increased risk of PIVC colonization and/or local infection (HR [95% CI], 1.64 [0.92—2.93] and 2.11 [1.08—4.13]) and of positive PIVC tip culture (HR [95% CI], 1.49 [1.02—2.18] and 1.59 [0.98—2.59]).ConclusionPIVC insertion at the wrist or cubital fossa should be avoided whenever possible to reduce the risk of catheter colonization and/or local infection and of positive PIVC tip culture.

An overview of diabetes-related foot ulcers.

The escalating prevalence of diabetes mellitus presents concern due to its widespread organ damage, including the heart, kidneys, eyes, and nerves, leading to severe complications such as heart attacks, strokes, blindness, and diabetes-related foot ulcers (DFUs). Management in the community setting should be focused on prevention, assessment and patient-centred care. By understanding the complex aetiology, risk factors, and classification of DFUs, along with utilising evidence-based interventions like the Wound, Infection and Ischemia (WIfI) system, we can streamline care. Neuropathy, peripheral arterial disease and infection are major contributors to DFU development, highlighting the importance of early detection and intervention. Comprehensive care addressing vascular health, infection control, pressure offloading, wound management, metabolic control, and patient education is essential for successful DFU management. Ultimately, proactive prevention strategies and interdisciplinary collaboration are necessary in the management of DFUs and improving patient outcomes.

The antimicrobial susceptibility patterns of diabetic foot ulcers in the South African public healthcare sector.

Diabetic foot syndrome is defined as the presence of a diabetic foot ulcer (DFU) associated with neuropathy, peripheral artery disease and infection. While the use of antimicrobials in the treatment of DFU infection remains a mainstay, the choice of antimicrobial remains problematic owing to the presence of multidrug-resistant polymicrobial infections. In the South African public healthcare sector, the treatment of DFUs is based on the Standard Treatment Guidelines (STGs) and the Essential Drug List. These guidelines are developed using evidence-based medicine and are based on global susceptibility patterns rather than local susceptibility data, and may not provide the most appropriate treatment options. To determine the antimicrobial susceptibility patterns of DFUs isolated from patients visiting selected Gauteng provincial public hospitals in order to determine a clinically effective treatment protocol for the management of these infections. Sample swabs were taken from 51 DFUs using the Levine method. Each sample swab was spread onto blood agar plates, and thereafter individual pathogens were isolated. The antimicrobial susceptibility patterns of all isolated pathogens were determined using zone of inhibition measurements. Pathogens were grouped according to macromorphological characteristics as well as susceptibility patterns, and a representative isolate from each group was then identified. A total of 51 DFU ulcer swabs from 45 patients were included in the study. From the sample swabs, a total of 445 pathogens were isolated. The most effective antimicrobial was found to be gentamicin, followed by ciprofloxacin. Amoxicillin/clavulanic acid, the first-line treatment according to the STGs, was found to be ineffective for many of the isolated pathogens. The most commonly isolated pathogens were Proteus mirabilis, Enterococcus faecalis and Pseudomonas aeruginosa. These findings demonstrate the urgent need to reassess the STGs and base treatment plans on local epidemiological data. This study provides valuable data on common causative pathogens in DFU infections, as well as the resistance patterns of these pathogens, forming a baseline on which to base future DFU treatment plans.

Interactive exploration of adverse events and multimorbidity in CKD.

Persons with chronic kidney disease (CKD) are at increased risk of adverse events, early mortality, and multimorbidity. A detailed overview of adverse event types and rates from a large CKD cohort under regular nephrological care is missing. We generated an interactive tool to enable exploration of adverse events and their combinations in the prospective, observational German CKD (GCKD) study. The GCKD study enrolled 5217 participants under regular nephrological care with an estimated glomerular filtration rate of 30-60 or >60mL/min/1.73m2 and an overt proteinuria. Cardio-, cerebro- and peripheral vascular, kidney, infection, and cancer events, as well as deaths were adjudicated following a standard operation procedure. We summarized these time-to-event data points for exploration in interactive graphs within an R shiny app. Multivariable adjusted Cox models for time to first event were fitted. Cumulative incidence functions, Kaplan-Meier curves and intersection plots were used to display main adverse events and their combinations by sex and CKD etiology. Over a median of 6.5 years, 10271 events occurred in total and 680 participants (13.0%) died while 2947 participants (56.5%) experienced any event. The new publicly available interactive platform enables readers to scrutinize adverse events and their combinations as well as mortality trends as a gateway to better understand multimorbidity in CKD: incident rates per 1000 patient-years varied by event type, CKD etiology, and baseline characteristics. Incidence rates for the most frequent events and their recurrence were 113.6 (cardiovascular), 75.0 (kidney), and 66.0 (infection). Participants with diabetic kidney disease and men were more prone to experiencing events. This comprehensive explorative tool to visualize adverse events (https://gckd.diz.uk-erlangen.de/), their combination, mortality, and multimorbidity among persons with CKD may manifest as a valuable resource for patient care, identification of high-risk groups, health services, and public health policy planning.

Treatment of Aorto-iliac and Infrainguinal Vascular Infections with a Prefabricated Bovine Pericardial Graft

The use of biological grafts provides acceptable mid- and long-term results in native or prosthetic vascular infections. Several reports describe the successful use of bovine pericardium in case of vascular infections, mainly as a large patch to be sutured as a tubular graft. Recently, a novel prefabricated bovine pericardium graft (Biointegral Surgical No-React® Inc, Mississauga, ON, Canada) has been introduced in clinical practice with promising results. In this study, we report our preliminary experience utilizing Biointegral Surgical graft in case of native and or prosthetic aorto-iliac and infrainguinal infection. We retrospectively analyzed data from 20 patients with native or prosthetic aorto-iliac and infrainguinal infection who underwent in situ reconstruction (ISR) with a Biointegral Surgical No-React bovine pericardium prosthesis between October 2020 and February 2023 at the Vascular Surgery Unit of the Fondazione Policlinico Universitario Gemelli - IRCCS in Rome, Italy. All patients followed a standardized protocol including postoperative anticoagulation and long-term intravenous antibiotics. The indication for surgery was: mycotic aortic aneurysm in 4 patients (20%), graft infection after abdominal aortic repair in 11 patients (55%), peripheral graft infection in 5 patients (25%). Complete excision of the infected aorta or prosthetic graft, surgical debridement and ISR were performed in all patients. Hospital mortality rate was 5% (n=1) and graft-related mortality of 0%. During follow-up (median 13months, range 6-34months), reinfection was 5.2% and primary graft patency 94.7%. The use of prefabricated bovine pericardial grafts represents a promising option for the treatment of native and prosthetic aorto-iliac and infrainguinal infections. The application of this biological graft with a standardized postoperative protocol has been associated with a satisfactory patency and reinfection rate without increased bleeding complications.

An update review of post-transplant diabetes mellitus: Concept, risk factors, clinical implications and management.

Kidney transplantation is the gold standard therapeutic alternative for patients with end-stage renal disease; nevertheless, it is not without potential complications leading to considerable morbidity and mortality such as post-transplant diabetes mellitus (PTDM). This narrative review aims to comprehensively evaluate PTDM in terms of its diagnostic approach, underlying pathophysiological pathways, epidemiological data, and management strategies. Articles were retrieved from electronic databases using predefined search terms. Inclusion criteria encompassed studies investigating PTDM diagnosis, pathophysiology, epidemiology, and management strategies. PTDM emerges as a significant complication following kidney transplantation, influenced by various pathophysiological factors including peripheral insulin resistance, immunosuppressive medications, infections, and proinflammatory pathways. Despite discrepancies in prevalence estimates, PTDM poses substantial challenges to transplant. Diagnostic approaches, including traditional criteria such as fasting plasma glucose (FPG) and HbA1c, are limited in their ability to capture early PTDM manifestations. Oral glucose tolerance test (OGTT) emerges as a valuable tool, particularly in the early post-transplant period. Management strategies for PTDM remain unclear, within sufficient evidence from large-scale randomized clinical trials to guide optimal interventions. Nevertheless, glucose-lowering agents and life style modifications constitute primary modalities for managing hyperglycemia in transplant recipients. The complex interplay between PTDM and the transplant process necessitates individualized diagnostic and management approaches. While early recognition and intervention are paramount, modifications to maintenance immunosuppressive regimens based solely on PTDM risk are not warranted, given the potential adverse consequences such as increased rejection risk. Further research is essential to refine management strategies and enhance outcomes for transplant recipients.

Resolving a paradox: antidepressants, neuroinflammation, and neurodegeneration

Depression is a known risk factor for dementia. Antidepressants are the most commonly used treatment for this condition, and are effective in at least half to two-thirds of cases. Extensive evidence from in vitro and animal models suggests that antidepressants have anti-inflammatory and neuroprotective properties. These effects have been shown to reduce the oxidative damage, amyloid aggregation, and expression of pro-inflammatory genes associated with animal models of neurodegenerative disorders. However, longitudinal research in humans has shown that antidepressants do not protect against dementia, and may even be associated with a risk of cognitive deterioration over time in older adults. The contrast between two sets of findings represents a paradox of significant clinical and public health significance, particularly when treating depression in late life. This review paper attempts to resolve this paradox by critically reviewing the medium- and long-term effects of antidepressants on peripheral immune-inflammatory responses, infection risk, gut microbiota, and neuroendocrine responses to stress, and how these effects may influence the risk of neurodegeneration. Briefly stated, it is possible that the peripheral actions of antidepressant medications may antagonize their beneficial effects against neuroinflammation. The implications of these findings are then explored with a particular focus on the development and testing of multimodal neuroprotective and anti-inflammatory treatments that could reduce the risk of Alzheimer’s and related dementias in patients suffering from depression.

Authors' response to “Comment on Marsh et al. (2023) ‘Peripheral intravenous catheter infection and failure: A systematic review and meta-analysis’”

Authors' response to “Comment on Marsh et al. (2023) ‘Peripheral intravenous catheter infection and failure: A systematic review and meta-analysis’”

Foot Amputation in a diabetic patient who didn’t follow-up for five years

Diabetes foot ulcers (DFUs), a vascular endothelial complication, are linked to higher morbidity and mortality. DFUs are caused by a complex mix of neuropathy, peripheral arterial disease, foot deformities, and infections. Foot ulcers are a leading cause of morbidity in diabetics, and they are usually preceded by peripheral arterial disease, neuropathy, or a combination of the three, as well as other factors. We review the case of a 46 years old man who was evaluated with a small oozing wound. He did not see his doctor about his glucose level for 5 years. When he was presented with the oozing, his X-ray of the left leg and MRI of the left lower leg without contrast revealed osteomyelitis. After three days of Clindamycin administration, the patient was taken to the operating room for a left partial ray amputation as well as a left leg incision and drainage. His wound improved from scant serosanguinous drainage to peri skin dry and peeling skin underneath after continuous dressing in his post-amputation partial ray, an overall area greatly improving and healing wound. This case report summarizes the consequences of not visiting a doctor's office if you have diabetes symptoms.

Simian varicella virus infection and reactivation in rhesus macaques trigger cytokine and Aβ40/42 alterations in serum and cerebrospinal fluid.

Simian varicella virus (SVV) produces peripheral inflammatory responses during varicella (primary infection) and zoster (reactivation) in rhesus macaques (RM). However, it is unclear if peripheral measures are accurate proxies for central nervous system (CNS) responses. Thus, we analyzed cytokine and Aβ42/Aβ40 changes in paired serum and cerebrospinal fluid (CSF) during the course of infection. During varicella and zoster, every RM had variable changes in serum and CSF cytokine and Aβ42/Aβ40 levels compared to pre-inoculation levels. Overall, peripheral infection appears to affect CNS cytokine and Aβ42/Aβ40 levels independent of serum responses, suggesting that peripheral disease may contribute to CNS disease.

Tetraspanin CD53 regulates peripheral blood leucocytes vitality and pathogen infection in turbot (Scophthalmus maximus)

Cluster of differentiation 53 (CD53) also known as OX44 or tetraspanin 25 (TSPAN25) is a glycoprotein belonging to the tetraspanin family. Members of the tetraspanin family are characterized by four transmembrane domains, including intracellular N- and C-termini, and small and large extracellular domains. Currently, the function of CD53 in teleost is not well understood. In this study, we identified a CD53 (named SmCD53) from turbot (Scophthalmus maximus) and examined its expression and biological activity. SmCD53 contained 231 amino acid residues and was predicted to be a tetraspanin with small and large extracellular domains. SmCD53 expression was observed in different tissues, particularly in immune-related organs. Experimental infection with bacterial or viral pathogen significantly up-regulated SmCD53 expression in a time-dependent manner. Immunofluorescence microscopy analysis showed that SmCD53 was localized on the surface of PBL and was recognized by antibody against its large extracellular domain. Ligation of SmCD53 onto PBLs with antibodies suppressed the respiratory burst activity, inflammatory reaction, and enhanced cell viability. SmCD53 knockdown significantly enhanced bacterial dissemination and proliferation in turbot. Overall, these results underscore the importance of CD53 in the maintenance of the function and homeostasis of the immune system.

Healing rates and outcomes following closed transmetatarsal amputations: A systematic review and random effects meta-analysis of proportions.

Transmetatarsal amputation (TMA) is a common surgical procedure for addressing severe forefoot pathologies, such as peripheral vascular disease and diabetic foot infections. Variability in research methodologies and findings within the existing literature has hindered a comprehensive understanding of healing rates and complications following TMA. This meta-analysis and systematic review aims to consolidate available evidence, synthesising data from multiple studies to assess healing rates and complications associated with closed TMA procedures. Following Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines, a systematic search of Medline, Embase, and Cochrane databases was conducted for articles published from January 1st, 1988, to June 1st, 2023. Inclusion criteria comprised studies reporting healing rates in non-traumatic transmetatarsal amputation patients with more than 10 participants, excluding open TMAs. Two independent reviewers selected relevant studies, with disagreements resolved through discussion. Data extracted from eligible studies included patient demographics, healing rates, complications, and study quality. Among 22 studies encompassing 1569 transmetatarsal amputations, the pooled healing rate was 67.3%. Major amputation rates ranged from 0% to 55.6%, with a random-effects pooled rate of 23.9%. Revision rates varied from 0% to 36.4%, resulting in a pooled rate of 14.8%. 30-day mortality ranged from 0% to 9%, with a fixed-effects pooled rate of 2.6%. Post-operative infection rates ranged from 3.0% to 30.7%, yielding a random-effects pooled rate of 16.7%. Dehiscence rates ranged from 1.7% to 60.0%, resulting in a random-effects pooled rate of 28.8%. Future studies should aim for standardised reporting and assess the physiological and treatment factors influencing healing and complications.

Infectious Diseases.

Microglia, brain-resident innate immune cells, have been extensively studied in neurodegenerative contexts like Alzheimer's disease. The Coronavirus disease 2019 (COVID-19) pandemic highlighted how peripheral infection and inflammation can be detrimental to the neuroimmune milieu and initiate microgliosis driven by peripheral inflammation. Microglia can remain deleterious to brain health by sustaining inflammation in the central nervous system even after the clearance of the original immunogenic agents. In this chapter, we discuss how pulmonary infection with Severe Acute Respiratory Syndrome CoronaVirus 2 (SARS-CoV-2) can lead to neurovascular and neuroimmune inflammation causing the neurological syndrome of post-acute sequelae of COVID-19 (PASC). Further, we incorporate lessons from the Human Immunodeficiency Virus' (HIV's) effects on microglial functioning in the era of combined antiretroviral therapies (cART) that contribute to HIV-1 associated neurocognitive disorders (HAND). Finally, we describe roles for mixed lineage kinase 3 (MLK3) and leucine-rich repeat kinase (LRRK2) as key regulators of multiple inflammatory and apoptotic pathways important to the pathogenesis of PASC and HAND. Inhibition of these pathways provides a therapeutically synergistic method of treating both PASC and HAND.