Search Results (2,426)

Metformin (MTF) is the only biguanide included in the World Health Organization’s list of essential medicines; representing a widespread drug in the management of diabetes mellitus. With its accessibility and affordability being one of its biggest assets, it has become the target of interest for many trying to find alternative treatments for varied pathologies. Over time, an increasing body of evidence has shown additional roles of MTF, with unexpected interactions of benefit in other diseases. Metformin (MTF) holds significant promise in mitigating ischemia-reperfusion injury (IRI), particularly in the realm of organ transplantation. As acceptance criteria for organ transplants expand, IRI during the preservation phase remain a major concern within the transplant community, prompting a keen interest in MTF’s effects. Emerging evidence suggests that administering MTF during reperfusion may activate the reperfusion injury salvage kinase (RISK) pathway. This pathway is pivotal in alleviating IRI in transplant recipients, potentially leading to improved outcomes such as reduced rates of organ rejection. This review aims to contextualize MTF historically, explore its current uses, pharmacokinetics, and pharmacodynamics, and link these aspects to the pathophysiology of IRI to illuminate its potential future role in transplantation. A comprehensive survey of the current literature highlights MTF’s potential to recondition and protect against IRI by attenuating free radical damage, activating AMP-activated protein kinase to preserve cellular energy and promote repair, as well as directly reducing inflammation and enhancing microcirculation. Full article

Tissue engineering, a rapidly advancing field in medicine, has made significant strides with the development of artificial tissue substitutes to meet the growing need for organ transplants. Three-dimensional (3D) porous scaffolds are widely utilized in tissue engineering, especially in orthopedic surgery. This study investigated the fluidic properties of diamond and gyroid structures with varying porosity levels (50–80%) using Computational Fluid Dynamics (CFD) analysis. The pressure and velocity distributions were analyzed, and it was observed that the pressure decreased gradually, whereas the velocity increased in the central area of the surface structures. Specifically, the pressure drop ranged from 2.079 to 0.984 Pa for the diamond structure and from 1.669 to 0.943 Pa for the gyroid structure as the porosity increased from 50% to 80%. It was also found that the permeability increased as the porosity level increased, with values ranging from ${2.424\times 10}^{-9}$ to ${5.122\times 10}^{-9} {\mathrm{m}}^2$ for the diamond structure and from ${2.966\times 10}^{-9}$ to ${5.344\times 10}^{-9} {\mathrm{m}}^2$ for the gyroid structure. The wall shear stress (WSS) was also analyzed, showing a consistent decrease with increased porosity for both types of structures, with WSS values ranging from ${9.903\times 10}^{-2}$ to ${9.840\times 10}^{-1} \mathrm{P}\mathrm{a}$ for the diamond structure and from ${1.150\times 10}^{-1}$ to ${7.717\times 10}^{-2} \mathrm{P}\mathrm{a}$ for the gyroid structure. Overall, this study provides insights into the fluidic properties of diamond and gyroid structures, which can be useful in various applications such as tissue engineering. Full article

In order to maintain the polio eradication status, it has become evident that the surveillance of cases with acute flaccid paralysis and of environmental samples must be urgently supplemented with the surveillance of poliovirus excretions among individuals with inborn errors of immunity (IEI). All children with IEI were screened for the excretion of poliovirus during a collaborative study conducted by the ICMR-National Institute of Virology, Mumbai Unit, ICMR-National Institute of Immunohaematology, and World Health Organization, India. A seven-month -old male baby who presented with persistent pneumonia and lymphopenia was found to have severe combined immune deficiency (SCID) due to a missense variant in the RAG1 gene. He had received OPV at birth and at 20 weeks. Four stool samples collected at 4 weekly intervals yielded iVDPV type 1. The child’s father, an asymptomatic 32-year-old male, was also found to be excreting iVDPV. A haploidentical hematopoietic stem cell transplant was performed, but the child succumbed due to severe myocarditis and pneumonia three weeks later. We report a rare case of transmission of iVDPV from an individual with IEI to a healthy household contact, demonstrating the threat of the spread of iVDPV from persons with IEI and the necessity to develop effective antivirals. Full article

Uveal melanoma (UM) is the most common intraocular tumor in adults, and nearly 50% of patients develop metastatic disease with a high mortality rate. Therefore, the development of relevant preclinical in vivo models that accurately recapitulate the metastatic cascade is crucial. We exploited the chick embryo chorioallantoic membrane (CAM) xenograft model to quantify both experimental and spontaneous metastasis by qPCR analysis. Our study found that the transplanted UM cells spread predominantly and early in the liver, reflecting the primary site of metastasis in patients. Visible signs of pigmented metastasis were observed in the eyes, liver, and distal CAM. Lung metastases occurred rarely and brain metastases progressed more slowly. However, UM cell types of different origins and genetic profiles caused an individual spectrum of organ metastases. Metastasis to multiple organs, including the liver, was often associated with risk factors such as high proliferation rate, hyperpigmentation, and epithelioid cell type. The severity of liver metastasis was related to the hepatic metastatic origin and chromosome 8 abnormalities rather than monosomy 3 and BAP1 deficiency. The presented CAM xenograft model may prove useful to study the metastatic potential of patients or to test individualized therapeutic options for metastasis in different organs. Full article

Graft-versus-host disease (GVHD) is an expected and relatively common complication after allogeneic hematopoietic stem cell transplantation. It may affect different organs and typically involves the skin, liver, and gastrointestinal tract (GI-GVHD). GI-GVHD may show heterogeneous presentations with peculiar diagnostic implications. Although an endoscopic biopsy is considered the “gold standard” for the diagnosis of GI-GVHD, its broad application is limited due to the poor clinical conditions usually present in these patients, including thrombocytopenia. In the emergency department, enhanced computed tomography (CECT) has emerged as the best imaging modality for the evaluation of GI damage in frail patients. However, the role of CT in the context of either acute or chronic GI-GVHD has not been systematically investigated. Herein, we focus on the radiological features found on CECT in five patients with GI-GVHD confirmed on histology. CECT was performed for the persistence of GI symptoms in three cases (case 1, case 3, and case 4), for small bowel occlusion in one case (case 5), and for acute GI symptoms in one case (case 2). Serpiginous intestinal wall appearance with multisegmental parietal thickness and homogeneous, mucosal, or stratified small bowel enhancement were common features. Colic involvement with segmental or diffuse parietal thickness was also present. One patient (case 5) presented with inflammatory jejunal multisegmental stenosis with sub-occlusion as a chronic presentation of GI-GVHD. Regarding mesenterial findings, all five patients presented comb signs in the absence of lymphadenopathy. Extraintestinal findings included biliary tract dilatation in two cases (case 2 and case 4). These data support the utility of appropriate radiological investigation in GI-GVHD, paving the way for further serial and systematic investigations to track the appearance and evolution of GI damage in GVHD patients. Full article

Invasive aspergillosis (IA) represents a common form of fungal infection caused by various species of Aspergillus that most frequently affect immunocompromised patients. Typically, this disease occurs preferentially in high-risk groups including patients infected with the human immunodeficiency virus (HIV), patients with leukemia, patients with autoimmune diseases, and organ transplant patients undergoing medical immunosuppression. Considered the second most common cause of opportunistic fungal infection in humans after Candida albicans, this pathogen predominantly affects the lungs, but it may also spread by a hematogenous route to various organs and have a heterogeneous presentation. Owing to its high iodine levels, high perfusion, and enclosed capsule, the thyroid gland is considered to have a lower susceptibility to microbial invasion, and it is fairly uncommon to find associated infectious nodules. In metabolic imaging, ¹⁸F-FDG-PET/CT has become increasingly useful for detecting a wide range of infectious and inflammatory diseases and is already the gold standard for certain indications. According to the literature, no studies of hypermetabolic nodular thyroid aspergillosis on ¹⁸F-FDG-PET/CT confirmed on histology have yet been reported. Here, we report the first case of a patient with a heterogeneous presentation of IA and the presence of a hypermetabolic nodule in the thyroid with a surprising result. Full article

Despite the significant progress made, CMV infection is one of the most frequent infectious complications in transplant recipients. CMV infections that become refractory or resistant (R/R) to the available antiviral drugs constitute a clinical challenge and are associated with increased morbidity and mortality. Novel anti-CMV therapies have been recently developed and introduced in clinical practice, which may improve the treatment of these infections. In this review, we summarize the treatment options for R/R CMV infections in adult hematopoietic cell transplant and solid organ transplant recipients, with a special focus on newly available antiviral agents with anti-CMV activity, including maribavir and letermovir. Full article

Transplanted organs experience several episodes of ischemia and ischemia-reperfusion. The graft injury resulting from ischemia-reperfusion (IRI) remains a significant obstacle to the successful survival of transplanted grafts. Temperature significantly influences cellular metabolic rates because biochemical reactions are highly sensitive to temperature changes. Consequently, lowering the temperature could reduce the degradative reactions triggered by ischemia. In mitigating IRI in liver grafts, the potential protective effect of localized hypothermia on the liver prior to blood flow obstruction has yet to be explored. In this study, we applied local hypothermia to mouse donor livers for a specific duration before stopping blood flow to liver lobes, a procedure called “liver precooling”. Mouse donor liver temperature in control groups was controlled at 37 °C. Subsequently, the liver donors were preserved in cold University of Wisconsin solution for various durations followed by orthotopic liver transplantation. Liver graft injury, function and inflammation were assessed at 1 and 2 days post-transplantation. Liver precooling exhibited a significant improvement in graft function, revealing more than a 47% decrease in plasma aspartate transaminase (AST) and alanine aminotransferase (ALT) levels, coupled with a remarkable reduction of approximately 50% in liver graft histological damage compared to the control group. The protective effects of liver precooling were associated with the preservation of mitochondrial function, a substantial reduction in hepatocyte cell death, and a significantly attenuated inflammatory response. Taken together, reducing the cellular metabolism and enzymatic activity to a minimum level before ischemia protects against IRI during transplantation. Full article

Pediatric solid organ transplant (SOT) recipients face a challenging balance between immunosuppression and graft rejection. While Epstein–Barr Virus (EBV) and cytomegalovirus (HCMV) are known contributors to post-transplant lymphoproliferative disease and graft rejection, respectively, the roles of herpesvirus 6 and 7 (HHV6 and HHV7) and the impact of these herpesviruses on cytokine levels remain unclear, leading to gaps in clinical practice. In this associative study, we measured 17 cytokines using a Bio-Plex assay in a meticulously curated plasma sample pool (N = 158) from pediatric kidney and liver transplant recipients over a one-year follow-up period. The samples included virus-negative and virus-positive cases, either individually or in combination, along with episodes of graft rejection. We observed that the elevation of IL-4, IL-8, and IL-10 correlated with graft rejection. These cytokines were elevated in samples where HCMV or HHV6 were detected alone or where EBV and HHV7 were co-detected. Interestingly, latent EBV, when detected independently, exhibited an immunomodulatory effect by downregulating cytokine levels. However, in co-detection scenarios with β-herpesviruses, EBV transitioned to a lytic state, also associating with heightened cytokinemia and graft rejection. These findings highlight the complex interactions between the immune response and herpesviruses in transplant recipients. The study advocates for enhanced monitoring of not only EBV and HCMV but also HHV6 and HHV7, providing valuable insights for improved risk assessment and targeted interventions in pediatric SOT recipients. Full article

Acute liver failure is a life-threatening organ dysfunction with systemic organ involvement and is associated with significant mortality and morbidity unless specific management is undertaken. This meta-analysis aimed to assess the effects of intravenous N-acetylcysteine (NAC) on mortality and the length of hospital stay in patients with non-acetaminophen acute liver failure. Two hundred sixty-six studies from four databases were screened, and four randomized control trials were included in the final analysis. Our results could not demonstrate increased overall survival (OR 0.70, 95% CI [0.34, 1.44], p = 0.33) or transplant-free survival (OR 0.90, 95% CI [0.25, 3.28], p = 0.87) in patients treated with intravenous NAC. We observed an increased overall survival in adult patients treated with NAC (OR 0.59, 95% CI [0.35, 0.99], p = 0.05) compared to pediatric patients, but whether this is attributed to the age group or higher intravenous dose administered remains unclear. We did not observe a decreased length of stay in NAC-treated patients (OR −5.70, 95% CI [−12.44, 1.05], p = 0.10). In conclusion, our meta-analysis could not demonstrate any significant benefits on overall and transplant-free patient survival in non-acetaminophen ALF. Future research should also focus on specific etiologies of ALF that may benefit most from the use of NAC. Full article

Introduction: Psychosocial pre-transplant evaluation in patients undergoing liver transplantation (LT) could help identify those patients at higher risk of pharmacological non-adherence, organ rejection, and mortality. The Stanford Integrated Psychosocial Assessment for Transplantation (SIPAT) is a validated tool for assessing LT candidates’ psychosocial well-being. Data on the ability of the SIPAT evaluation to predict post-transplant outcomes are sparse. Material and Methods: clinical and psychosocial data from a sample of 134 candidates for LT were analyzed. Moreover, the association between pre-transplant psychosocial evaluation and post-transplant clinical outcomes, including organ rejection, mortality, and immunosuppressant drug adherence, was calculated. Results: At the pre-transplant evaluation, patients who showed high SIPAT scores (77, 57%) also had more liver disease assessed by model for end-stage liver disease (MELD; F = 5.04; p < 0.05), alcoholic etiology (F = 35.80; p < 0.001), encephalopathy (F = 5.02; p < 0.05), and portal hypertension (F = 7.45; p < 0.01). Of the 51 transplant patients, those who had a high pre-transplant SIPAT score showed lower post-transplant immunosuppressive adherence, linked to more frequent immunological events. Conclusions: Patients with an alcoholic etiology of liver disease and more severe liver dysfunction are likelier to not adhere to medical prescriptions following transplantation. Current data suggests that this specific group of patients could benefit from early psychological pre-habilitation before undergoing liver transplantation. Full article

Cell-based therapies using corneal stromal stem cells (CSSC), corneal keratocytes, or a combination of both suppress corneal scarring. The number of quiescent keratocytes in the cornea is small; it is difficult to expand them in vitro in quantities suitable for transplantation. This study examined the therapeutic effect of corneal fibroblasts reversed into keratocytes (rCF) in a mouse model of mechanical corneal injury. The therapeutic effect of rCF was studied in vivo (slit lamp, optical coherence tomography) and ex vivo (transmission electron microscopy and immunofluorescence staining). Injection of rCF into the injured cornea was accompanied by recovery of corneal thickness, improvement of corneal transparency, reduction of type III collagen in the stroma, absence of myofibroblasts, and the improvement in the structural organization of collagen fibers. TEM results showed that 2 months after intrastromal injection of cells, there was a decrease in the fibril density and an increase in the fibril diameter and the average distance between collagen fibrils. The fibrils were well ordered and maintained the short-range order and the number of nearest-neighbor fibrils, although the averaged distance between them increased. Our results demonstrated that the cell therapy of rCF from ReLEx SMILe lenticules promotes the recovery of transparent corneal stroma after injury. Full article

Orthotopic liver transplantation stands as the sole curative solution for end-stage liver disease. Nevertheless, the discrepancy between the demand and supply of grafts in transplant medicine greatly limits the success of this treatment. The increasing global shortage of organs necessitates the utilization of extended criteria donors (ECD) for liver transplantation, thereby increasing the risk of primary graft dysfunction (PGD). Primary graft dysfunction (PGD) encompasses early allograft dysfunction (EAD) and the more severe primary nonfunction (PNF), both of which stem from ischemia–reperfusion injury (IRI) and mitochondrial damage. Currently, the only effective treatment for PNF is secondary transplantation within the initial post-transplant week, and the occurrence of EAD suggests an elevated, albeit still uncertain, likelihood of retransplantation urgency. Nonetheless, the ongoing exploration of novel IRI mitigation strategies offers hope for future improvements in PGD outcomes. Establishing an intuitive and reliable tool to predict upcoming graft dysfunction is vital for early identification of high-risk patients and for making informed retransplantation decisions. Accurate diagnostics for PNF and EAD constitute essential initial steps in implementing future mitigation strategies. Recently, novel methods for PNF prediction have been developed, and several models for EAD assessments have been introduced. Here, we provide an overview of the currently scrutinized predictive tools for PNF and EAD evaluation strategies, accompanied by recommendations for future studies. Full article

Background: Sleep deprivation and disturbances in circadian rhythms may hinder surgical performance and decision-making capabilities. Solid organ transplantations, which are technically demanding and often begin at uncertain times, frequently during nighttime hours, are particularly susceptible to these effects. This study aimed to assess how transplant operations conducted during daytime versus nighttime influence both patient and graft outcomes and function. Methods: simultaneous pancreas–kidney transplants (SPKTs) conducted at the University Hospital of Leipzig from 1998 to 2018 were reviewed retrospectively. The transplants were categorized based on whether they began during daytime hours (8 a.m. to 6 p.m.) or nighttime hours (6 p.m. to 8 a.m.). We analyzed the demographics of both donors and recipients, as well as primary outcomes, which included surgical complications, patient survival, and graft longevity. Results: In this research involving 105 patients, 43 SPKTs, accounting for 41%, took place in the daytime, while 62 transplants (59%) occurred at night. The characteristics of both donors and recipients were similar across the two groups. Further, the rate of (surgical) pancreas graft-related complications and reoperations (daytime 39.5% versus nighttime 33.9%; p = 0.552) were also not statistically significant between both groups. In this study, the five-year survival rate for patients was comparable for both daytime and nighttime surgeries, with 85.2% for daytime and 86% for nighttime procedures (p = 0.816). Similarly, the survival rates for pancreas grafts were 75% for daytime and 77% for nighttime operations (p = 0.912), and for kidney grafts, 76% during the day compared to 80% at night (p = 0.740), indicating no significant statistical difference between the two time periods. In a multivariable model, recipient BMI > 30 kg/m², donor age, donor BMI, and cold ischemia time > 15 h were independent predictors for increased risk of (surgical) pancreas graft-related complications, whereas the timepoint of SPKT (daytime versus nighttime) did not have an impact. Conclusions: The findings from our retrospective analysis at a big single German transplant center indicate that SPKT is a reliable procedure, regardless of the start time. Additionally, our data revealed that patients undergoing nighttime transplants have no greater risk of surgical complications or inferior results concerning long-term survival of the patient and graft. However, due to the small number of cases evaluated, further studies are required to confirm these results. Full article

The combination of nanosecond Pulsed Electric Field (nsPEF) with pharmaceuticals is a pioneering therapeutic method capable of enhancing drug uptake efficacy in cells. Utilizing nsPEFs configured at 400 pulses, an electric field strength of 15 kV/cm, a pulse duration of 100 ns, and a repetition rate of 10 pulses per second (PPS), we combined the nsPEF with a low dose of doxorubicin (DOX) at 0.5 μM. Upon verifying that cells could continuously internalize DOX from the surrounding medium within 1 h post nsPEF exposure, we set the DOX exposure period to 10 min and contrasted the outcomes of varying sequences of DOX and nsPEF administration: pulsing followed by DOX, DOX followed by pulsing, and DOX applied 40 min after pulsing. Flow cytometry, CCK-8 assays, and transmission electron microscopy (TEM) were employed to examine intracellular DOX accumulation, cell viability, apoptosis, cell cycle, and ultrastructural transformations. Our findings demonstrate that exposing cells to DOX 40 min subsequent to nsPEF treatment can effectively elevate intracellular DOX levels, decrease cell viability, and inhibit the cell cycle. This research work presents a novel approach to enhance DOX uptake efficiency with moderate conditions of both DOX and nsPEF. Full article