Diaphyseal-engaging stems are conventionally used in conversion total hip arthroplasty (cTHA) after prior intramedullary nailing (IMN) to bypass screw holes and previously instrumented metadiaphyses. However, it remains unclear if cementless metaphyseal or standard cemented stems can also provide satisfactory fixation in this scenario. This study compared the early outcomes of cTHA using three femoral stem designs: metaphyseal cementless, diaphyseal cementless, and standard cemented. A retrospective review of 80 patients who underwent cTHA after prior IMN at a single academic center from 2014 to 2024 was conducted. Patients received either a metaphyseal press-fit stem, a standard-length cemented stem, or a diaphyseal-engaging stem. The 90-day complications were recorded, including any reoperation, periprosthetic joint infection (PJI), periprosthetic femoral fracture, or dislocation. An "at-risk" subgroup analysis of stem tips that were within four centimeters proximal of the interlock hole was also conducted. Patients who received metaphyseal stems were younger (56 versus 77 versus 72 years, P < 0.001) and had lower Charlson Comorbidity Index (1.5 versus 4.0 versus 2.2, P = 0.019) scores compared to those who received cemented stems or diaphyseal stems. There were no significant differences in 90-day complication rates observed among the three stem groups (P = 0.10). Notably, no postoperative periprosthetic fractures occurred in any group (P = 1.000). There were no differences in reoperation (P = 0.232), PJI (P = 1.00), or dislocation (P = 0.61) rates between the three groups. The "at-risk" subgroup analysis of 15 patients demonstrated no significant differences among the three groups for any complication and, notably, had no postoperative periprosthetic fractures. Metaphyseal-engaging stems and standard cemented stems in cTHA after IMN demonstrated similar outcomes to diaphyseal stems and may be reasonable options in cTHA after IMN in select patients.
The triple-tapered, collared (TTC) femoral stems are increasingly being used in primary total hip arthroplasty (THA) and have demonstrated favorable clinical outcomes. However, their effect on proximal femoral bone mineral density (BMD) and stress-shielding remains unknown. The purpose of this study was to assess changes in proximal femoral BMD at one year following implantation of a cementless TTC stem. The secondary aims were to evaluate the influence of surgical approach and collar seating on postoperative BMD and to compare BMD changes associated with the TTC stem to those of a cementless, single-tapered, wedge-type (STW) stem. This single-institution prospective cohort study included 94 cementless primary THAs (45 direct anterior approach [DAA], 49 posterior approach [PA]) performed with a TTC stem. Dual-energy X-ray absorptiometry (DEXA) was obtained at six weeks and one year postoperatively. Ratios of one-year to six-week BMD values were calculated for each Gruen zone (R1 to R7). Results were compared to a previously published cohort of 31 STW stems from our institution. A mixed-effects model with repeated measures and Student's t-test were used for analyses. Across all Gruen zones, the TTC stem demonstrated limited BMD changes between six weeks and one year postoperatively (range, 0.91 to 1.03, P > 0.05). Collar seating on the calcar (77% of cases) was not associated with significant differences in BMD change in any Gruen zone. The DAA was associated with greater BMD change in Gruen zone 1 compared with the PA (0.90 versus 0.96, P = 0.025), with no differences in the other zones. There were no significant differences in BMD ratios observed between the TTC and STW cohorts at one year. The TTC stem demonstrated limited proximal femoral BMD changes between six weeks and one year following primary THA. Collar seating was not associated with differences in BMD, whereas a modest difference in Gruen zone 1 was observed between surgical approaches. Longer-term follow-up is warranted to further characterize proximal femoral bone remodeling with the TTC stem design.
Dry eye disease (DED) is a multifactorial ocular surface disorder characterized by loss of tear film homeostasis, inflammation, neurosensory abnormalities, and epithelial damage. Despite the availability of topical immunomodulators and procedural interventions, a substantial proportion of patients with moderate-to-severe or refractory DED experience persistent symptoms and inadequate ocular surface recovery. Stem cell-based therapies, particularly mesenchymal stem cells (MSCs) and MSC-derived exosomes, have emerged as regenerative and immunomodulatory strategies aimed at restoring epithelial integrity and tear film stability rather than providing solely symptomatic relief. We conducted a systematic review and meta-analysis to evaluate the clinical efficacy and safety of stem cell and stem cell-derived therapies in human DED. This study followed PRISMA 2020 guidelines and was prospectively registered in PROSPERO (CRD420251057372). Six databases were searched from inception to May 14, 2025. Eligible studies were peer-reviewed human clinical investigations evaluating stem cell-based interventions for DED and reporting objective efficacy outcomes such as Schirmer test, tear break-up time (TBUT), corneal fluorescein staining (CFS), or patient-reported outcomes including the Ocular Surface Disease Index (OSDI). Pooled mean differences (MDs) or standardized mean differences (SMDs) with 95% confidence intervals (CIs) were calculated. Statistical heterogeneity was assessed using the I² statistic. Risk of bias was evaluated using RoB 2 for randomized controlled trials and ROBINS-I for non-randomized studies. Six studies comprising 131 patients were included. Stem cell-based therapies demonstrated significant improvements in tear production, tear film stability, epithelial integrity, and symptom burden. Schirmer test improved by MD = 4.70 mm (95% CI, 4.18-5.22; p < 0.001; I² = 12.59%), indicating a consistent enhancement of aqueous tear secretion. TBUT showed a large standardized improvement with pooled SMD = 1.125 (95% CI, 0.821-1.428; p < 0.001), although randomized trials demonstrated smaller effect sizes than non-randomized studies. OSDI scores decreased by MD = -11.44 points (95% CI, -22.71 to -0.17; p = 0.047), reflecting symptomatic improvement but with substantial between-study variability. Corneal fluorescein staining decreased by MD = -1.04 (95% CI, -1.23 to -0.84; p < 0.001; I² = 0%), supporting epithelial recovery. No serious treatment-related adverse events were reported; however, safety reporting was heterogeneous and follow-up durations were limited. Stem cell and stem cell-derived therapies are associated with significant improvements in both objective and subjective outcomes in DED and demonstrate a favorable short-term safety profile. Nevertheless, heterogeneity in cell source, delivery route, dosage, and study design limits generalizability. Larger, rigorously designed randomized trials with standardized protocols and longer follow-up are required to confirm efficacy and establish long-term safety.
Cemented femoral fixation is recommended for arthroplasty in femoral neck fracture (FNF) because of lower periprosthetic fracture risk, but carries cement-related risks, longer operative time, and technical variability. Modern collared cementless stems have emerged as potential alternatives. This study compared a triple-tapered collared cementless stem with a collared composite-beam cemented stem in total hip arthroplasty (THA) for displaced FNF. We asked the following: (1) Is periprosthetic fracture risk different between fixation strategies?; (2) Are revision rates and survivorship different?; (3) Are functional outcomes comparable?; and (4) Are mortality and complications affected by fixation type? We retrospectively reviewed 521 primary THAs for displaced FNF (2017 to 2024) at a tertiary center. Patients received a cemented collared composite-beam stem (n = 105) or a triple-tapered collared cementless stem (n = 416). Primary outcomes were periprosthetic femoral fracture and all-cause revision. The secondary outcomes included intraoperative fracture, wound debridement, aseptic loosening, periprosthetic joint infection, stem subsidence greater than five mm, dislocation, venous thromboembolism, mortality, and Harris Hip Score (HHS). Propensity score overlap-weighting balanced baseline covariates. Survivorship was assessed with Kaplan-Meier and an overlap-weighted Cox model. Outcomes were reanalyzed in the Dorr C subgroup. After overlap-weighting, baseline covariates were well balanced. Weighted periprosthetic fracture (2.74 versus 2.97%) and all-cause revision (2.76 versus 5.36%) were comparable. Revision-free survivorship through 24 months did not differ (hazard ratio 0.896; P = 0.916). There were no dislocations. HHS favored cementless fixation (mean difference 6.50 points; P < 0.0001). Mortality was low and similar between groups. Dorr C subgroup findings were consistent with the cohort. After propensity score overlap-weighting, periprosthetic fracture rates, revision rates, and 24-month revision-free survivorship were comparable between a triple-tapered collared cementless stem and a collared composite-beam cemented stem in displaced FNF THA. The HHS was higher in the cementless group. Modern collared cementless stems may represent a reasonable option in select patients. Larger multicenter prospective studies with longer follow-up are needed to confirm durability and refine patient selection.
Cancer stemness drives malignant progression and drug resistance in hepatocellular carcinoma (HCC). Although mitochondrial dynamics are known to influence HCC development, the precise mechanisms linking mitochondrial function to stemness remain largely elusive. Integrating bulk and single-cell transcriptomics, we identified Butyrophilin Subfamily 3 Member A3 (BTN3A3) as a novel oncogene driving HCC stemness. BTN3A3 depletion markedly reduced sphere formation, stemness-related gene expression, and the percentage of CD90+/EpCAM+ cancer stem cells. Rescue experiments confirmed that BTN3A3 promotes HCC cell proliferation, migration, and invasion. Furthermore, BTN3A3 depletion sensitized HCC cells to sorafenib by inducing ROS accumulation and apoptosis. Mechanistically, mass spectrometry and Co-IP identified TOMM22 as a key mitochondrial interactor of BTN3A3. Crucially, sorafenib stress actively promotes BTN3A3 mitochondrial translocation, where it shields TOMM22 from ubiquitin-proteasome-dependent degradation. BTN3A3 deficiency led to TOMM22 depletion, mitochondrial fragmentation, and impaired oxidative phosphorylation (OXPHOS) and ATP production. Importantly, silencing TOMM22 reversed BTN3A3-mediated stemness and sorafenib resistance. In vivo orthotopic xenograft models and patient-derived organoids (PDOs) further validated that BTN3A3 correlates with stemness and malignant tumor growth. Utilizing 5E08, a pan-BTN3 monoclonal antibody, markedly suppressed tumor growth and concurrently downregulated TOMM22 expression in vivo. In conclusion, our study unveils a previously unrecognized non-immunological role for BTN3A3 in mitochondrial reprogramming. We demonstrate that BTN3A3 drives HCC stemness and drug resistance by preventing TOMM22 ubiquitination to maintain mitochondrial homeostasis. These findings position BTN3A3 as a promising therapeutic target, with the pan-BTN3 monoclonal antibody 5E08 offering a potential strategy to overcome stemness-driven malignancy and resistance in HCC patients.
Motivational factors are widely recognized as central to students' engagement in cognitively demanding learning; however, the role of STEM career interest in the development of computational thinking during adolescence remains insufficiently understood. It is also unclear whether this association differs by gender. Grounded in Social Cognitive Career Theory, this study examined the association between STEM career interest and computational thinking among high school students and tested the moderating role of gender. Data were collected from 467 students (Mage = 16.05, SD = 1.20; 57.2% female) enrolled in public science high schools in Diyarbakır, Türkiye, using a descriptive correlational design. Participants completed the STEM Career Interest Scale and the Computational Thinking Skills Scale. Moderation analysis was conducted using PROCESS (Model 1) with 5,000 bootstrap resamples. STEM career interest was positively associated with computational thinking. Gender showed no significant main effect, and the interaction between STEM career interest and gender was not significant, indicating that the strength of this association was similar for female and male students. These findings suggest that, within academically selective STEM-focused environments, motivational orientations toward STEM are linked to computational thinking in comparable ways across genders. The results highlight the importance of supporting students' motivational engagement, alongside instructional practices, in fostering computational thinking during secondary education.
Allogeneic hematopoietic stem cell transplantation is an established curative therapy for many hematological diseases, but graft-versus-host disease remains a major cause of morbidity and mortality. Tacrolimus, a calcineurin inhibitor, is widely used for prophylaxis because it suppresses T-cell activation. However, its clinical use is complicated by a narrow therapeutic window and marked pharmacokinetic variability. Therapeutic drug monitoring based on trough whole-blood concentrations is routinely used to guide dosing, but this approach has limitations, particularly in transplantation recipients who experience rapid physiological and hematological changes. This review summarizes recent insights into determinants of tacrolimus pharmacology in hematopoietic stem cell transplantation and discusses emerging perspectives for individualized dosing. Tacrolimus exerts its immunosuppressive effects by forming a complex with FK506-binding proteins that inhibits calcineurin and suppresses activation of nuclear factor of activated T cells. Beyond this canonical mechanism, interactions with FK506-binding proteins influence the distribution of tacrolimus within blood cells. Because tacrolimus strongly divides into erythrocytes and leukocytes, whole-blood concentrations reflect systemic exposure and drug binding within circulating blood components. In recipients of hematopoietic stem cell transplantation, marked fluctuations in blood cell counts during conditioning therapy and hematopoietic recovery can alter this distribution, potentially causing changes in concentrations without corresponding changes in pharmacologically active exposure. Genetic variation in drug-metabolizing enzymes further contributes to variability in tacrolimus pharmacokinetics. In particular, polymorphisms in the gene encoding cytochrome P450 3A5 influence tacrolimus metabolism and may affect early dose requirements during the post-transplant period. Additionally, temporal fluctuations in tacrolimus exposure within individual patients are increasingly recognized as clinically relevant. Measures that capture the proportion of time during which concentrations remain within the therapeutic range provide a useful indicator of exposure stability. Tacrolimus therapy after hematopoietic stem cell transplantation is influenced by molecular pharmacology, blood cell-dependent distribution, genetic determinants of metabolism, and temporal variability in drug exposure. Integrating these factors may improve understanding of therapeutic drug monitoring and promote more individualized strategies to maintain stable immunosuppression and improve transplant outcomes.
Chronic wounds, such as diabetic ulcers, represent a substantial clinical difficulty because of impaired healing, often resulting from vascular and nerve damage associated with hyperglycemia. Traditional treatments primarily offer supportive care but frequently fail to fully restore tissue function, highlighting the urgent need for advanced regenerative strategies. Stem cell-based therapies, especially those leveraging secretome and exosomes, have gained attention as effective alternatives to direct stem cell transplantation. These cell-free approaches offer several advantages, including low immunogenicity, reduced risk of tumour formation, and greater ease of production, handling, and storage. Secretome and exosomes facilitate wound healing by modulating inflammation, promoting angiogenesis, aiding extracellular matrix remodelling, and stimulating the migration and proliferation of skin cells. Exosomes are vital for intercellular communication, delivering key regenerative signals that trigger anti-inflammatory responses and neovascularisation. Photobiomodulation (PBM), a non-invasive technique using specific light wavelengths, further enhances stem cell function and boosts the therapeutic impact of their secretome by influencing gene and protein expression. When combined, PBM and stem cell-derived secretome or exosomes offer a powerful treatment approach for chronic wound repair by activating critical biological pathways involved in regeneration of damaged tissue. This review highlights the current research on the roles of stem cell secretome, exosomes, and PBM in chronic wound treatment, with a focus on their synergistic mechanisms and promising therapeutic potential.
Leukemic stem cells (LSCs) are the cellular reservoir most strongly implicated in relapse of acute myeloid leukemia, yet their operational detection by multiparameter flow cytometry remains challenging because of immunophenotypic overlap with normal progenitors and variability across assays. Including CD45RA in the CD34⁺CD38⁻ gating strategy substantially improves discrimination between malignant and normal stem/progenitor populations and thus enables more precise LSC enumeration in a single-tube format. Given the clinical importance of accurately quantifying the LSC compartment, we evaluated a refined single-tube flow cytometry assay that incorporates CD45RA within the CD34 + CD38- gate to increase specificity for the leukemic stem compartment. In a retrospective cohort of 109 AML bone marrow samples, measurable residual disease (MRD) was assessed with a conventional three-tube, 8-color panel and LSCs were enumerated using an adapted single-tube, 8-color panel defining LSCs as CD34 + CD38-CD45RA + . To ensure analytical reliability we applied a formal lower limit of quantification (LLOQ), defined empirically as a cluster of 50 CD45 + events; samples below the sample-specific LLOQ were not called positive. Positivity thresholds were set at ≥ 0.1% for MRD and ≥ 0.004% for LSCs. Group comparisons used the Mann-Whitney U test and associations were quantified by Pearson correlation. LSCs were detectable in 28/109 (25.7%) patients, while MRD positivity was observed in 37/109 (33.9%) patients. A robust association was demonstrated between LSC presence and MRD positivity (p = 0.00035). The LSC burden was significantly elevated in MRD-positive patients, and concomitantly, MRD levels were profoundly higher in patients harboring detectable LSCs (p = 2.01 × 10⁻⁹). A strong positive correlation was observed between LSC and MRD levels across the entire cohort (R = 0.66, p = 3.2 × 10⁻15). LSC and MRD status were independent of sex, FLT3, or NPM1 mutation status. Immunophenotypic profiling of the LSC compartment revealed predominant aberrant co-expression of CD33 (89.3%) and a multi-marker cocktail (89.3%), with CD44 (67.9%) and CD123 (53.6%) also frequently observed. The implementation of a refined LSC detection assay, leveraging CD45RA gating and a stringent LLOQ, yields a specific and clinically actionable quantification of the LSC reservoir in AML. The strong correlation between the CD34 + CD38-CD45RA + LSC subset and MRD status suggests its potential as a complementary biomarker for residual disease monitoring; however, prospective validation in outcome-annotated cohorts is required to establish its prognostic utility and clinical applicability.
Diabetes mellitus (DM) is characterized by progressive β-cell dysfunction, and current therapies improve glycemic control without restoring endogenous β-cell mass. Induced pluripotent stem cell (iPSC)-based approaches offer a potential regenerative strategy. This systematic review and meta-analysis evaluates the efficacy and safety of iPSC-based interventions for diabetes in preclinical models. A comprehensive literature search was conducted in PubMed, ScienceDirect, and Web of Science for studies published up to November 2025. Studies assessing iPSC-based therapies in diabetic models were systematically reviewed and quantitatively synthesized. Thirty-one preclinical studies involving 424 animals were included. iPSC-based interventions were associated with reduced mortality (odds ratio [OR] 0.14) and reductions in blood glucose across 21 studies (mean difference [MD]  -267.36). Glucose-lowering effects were observed under fasting, non-fasting, and glucose-challenge conditions and were accompanied by increased insulin and C-peptide levels. Improvements were also reported in several diabetes-related complications, including cardiac dysfunction, impaired wound healing, neuropathy, and retinopathy. iPSC-based therapies show potential to improve glycemic control and diabetes-related complications in preclinical models, likely through a combination of endocrine replacement and paracrine-mediated regenerative mechanisms. However, substantial heterogeneity across outcome assessments, reliance on short- to mid-term follow-up, and limitations of experimental disease models constrain the interpretation and generalizability of these findings. Immune compatibility, long-term safety, and scalable manufacturing remain key challenges for clinical translation.
High bone mineral density (BMD) is common and sometimes an incidental finding. The causes are numerous. Among them, none has previously been attributed to total body irradiation (TBI). We present the case of a 56-year-old female patient with a history of T-lymphoblastic lymphoma at age 33 who was treated with allogeneic hematopoietic stem cell transplantation following a conditioning regimen including a single-fraction 10 Gray TBI. This patient was in complete remission but experienced several transplant-related late effects. She presented to the rheumatology outpatient clinic with chronic mechanical low back pain and a history of early menopause. Bone assessment by densitometry revealed high bone mineral density with a lumbar spine L2-L4 T-score of +6.3 standard deviation (SD) (1.939 g/cm²), right femoral neck T-score of +7.2 SD (1.849 g/cm²), right total femur T-score of +4 SD (1.484 g/cm²), distal radioulnar T-score of +0.7 SD (0.495 g/cm²). Imaging revealed sclerotic lesions in the vertebrae, femoral cortices and pelvis. An etiological workup excluded other causes such as fluorosis, mastocytosis, renal osteodystrophy, hypoparathyroidism/pseudohypoparathyroidism and myelofibrosis. Bone growth factors and resorption markers were normal. Genetic sequencing showed no significant abnormalities. Based on this comprehensive evaluation, TBI was identified as a possible contributing factor to the occurrence of high BMD. The patient was managed with analgesics and regular follow-up. This case highlights the importance of a systematic etiologic approach to high bone mineral density and underscores the need for future scientific research to better understand this phenomenon for which the pathological relationship with radiation exposure remains unknown.
Osteoarthritis is a chronic disabling disease characterized by progressive degeneration of articular cartilage. The condition is characterized by an imbalance in the inflammatory response, the degradation of the extracellular matrix, the apoptosis of chondrocytes, and the disorder of the immune microenvironment. The present clinical efficacy of the treatment is unsatisfactory due to the limited self-healing ability of the articular cartilage. In recent years, there has been a growing body of research focusing on the therapeutic potential of exosomes (Exos) derived from mesenchymal stem cells (MSCs). The findings of these studies have demonstrated the significant potential of MSC-derived exosomes as a promising cell-free therapeutic strategy. This article provides a synopsis of the research progress and mechanisms of mesenchymal stem cell-derived exosomes (MSC-Exos) from diverse tissue sources in the treatment of osteoarthritis. Furthermore, the application of MSC-Exos in the treatment of osteoarthritis were also discussed. The review will provide a valuable reference for future research directions in this field.
The HOXA gene locus coordinates body patterning, hematopoiesis, and differentiation. While studying blood phenotype-associated variation within the HOXA locus, we identified a genetic variant, rs17437411, associated with globally reduced blood counts, protection from blood cancers, and variation in anthropometric phenotypes. We found that this variant disrupts the activity of a previously unstudied antisense long non-coding RNA (lncRNA) located between HOXA7 and HOXA9, which we named HOXA opposite-strand transcript, stem-cell regulator, antisense mid-cluster between loci (HOTSCRAMBL). The HOTSCRAMBL variant disrupts lncRNA function and reduces human hematopoietic stem cell (HSC) self-renewal. Mechanistically, HOTSCRAMBL enables appropriate expression and splicing of HOXA genes in HSCs, most notably HOXA9, in an SRSF2-dependent manner. Given the critical role of HOXA gene expression in some blood cancers, we also demonstrate that HOTSCRAMBL variation or deletion compromises HOXA-dependent acute myeloid leukemias. Collectively, we show how insights from human genetic variation can uncover critical regulatory processes required for effective developmental gene expression.
Hematopoietic stem cell transplantation (HSCT) success relies on timely engraftment and immune reconstitution. While neutrophil and platelet recovery are well-established clinical endpoints, the dynamics of monocyte engraftment and their relationship with hematopoietic recovery remain insufficiently characterized. In this prospective observational study, 56 patients undergoing autologous (n = 32) or allogeneic (n = 24) peripheral blood stem cell transplantation were enrolled. Pre-engraftment monocyte peak day was defined based on serial complete blood counts. Flow cytometric analysis was performed at the time of monocyte engraftment to assess monocyte (CD14/CD16) and lymphocyte subsets. Associations between monocyte dynamics and neutrophil and platelet engraftment were evaluated using correlation and multivariable regression analyses. Allogeneic recipients demonstrated significantly delayed neutrophil engraftment compared to autologous patients (p=0.003). Pre-engraftment monocyte peak day was strongly correlated with neutrophil engraftment (ρ = 0.83, p < 0.001) and moderately correlated with platelet engraftment (ρ = 0.46, p = 0.001). In multivariable analyses, monocyte peak timing remained independently associated with both neutrophil (B = 0.87, p < 0.001) and platelet recovery (B = 1.53, p = 0.015), whereas CD34⁺ cell dose showed no independent association. Flow cytometric analysis demonstrated predominance of CD14⁺ monocytes during early engraftment. Despite elevated inflammatory markers in patients with complications, engraftment kinetics remained comparable. Pre-engraftment monocyte dynamics are strongly associated with subsequent hematopoietic recovery and may serve as an early indicator of engraftment following HSCT. These findings support the potential utility of monocyte-based monitoring in post-transplant care and highlight the need for further studies to validate their prognostic value.
Clark-Baraitser Syndrome (CLABARS) is an autosomal dominant neurodevelopmental disorder caused by pathogenic variants in the TRIP12 gene. Research into the molecular mechanisms of CLABARS has been limited by the lack of suitable human model systems. In this study, we introduce an induced pluripotent stem cell (iPSC) line derived from a CLABARS patient, providing a promising model to investigate mechanisms of altered cell lineage commitment during disease progression.
Cytomegalovirus (CMV) reactivation is a major cause of morbidity and mortality after haploidentical hematopoietic stem cell transplantation (Haplo-HSCT). While T cells are crucial for controlling CMV, the dynamic characteristics of the T-cell receptor (TCR) repertoire and their predictive value for refractory CMV reactivation remain poorly characterized. This study aimed to longitudinally monitor the TCR repertoire in Haplo-HSCT patients to identify features associated with CMV reactivation and to explore predictive biomarkers for refractory and recurrent CMV disease. We enrolled 164 Haplo-HSCT patients, of which a subset of 28 was prospectively monitored for TCR repertoire dynamics via multiplex PCR and high-throughput sequencing. Patients were stratified into control (no reactivation, n = 10), acute phase (first reactivation, n = 18), and resolution phase (after clearance, n = 18) groups. CMV-specific TCRs were identified by database matching. The incidence of CMV reactivation was 48.17% (79/164). CMV reactivation induced significant perturbations in TCR repertoire architecture, characterized by increased CDR3 clonality, reduced clonotype distribution evenness, and a decreased number of unique Clonotypes (all P < 0.05) compared to controls, indicating a state of oligoclonal expansion. This skewed architecture persisted even after viral clearance, suggesting delayed CMV-specific immune reconstitution. Consistent with this, patients with CMV reactivation had significantly lower CD4+ T cell counts compared to those without reactivation (P = 0.003). Longitudinal analysis revealed that impaired CD4+ T cell recovery preceded CMV reactivation. Patients with secondary reactivation (6/18) exhibited reduced diversity of V-J gene pairings (lower Shannon index, P < 0.05) and significant downregulation of specific TRBV28/TRBJ1-1 and TRBV6-1/TRBJ2-7 combinations. Crucially, lower abundance and total frequency of CMV-specific TCRs at initial reactivation predicted secondary reactivation (P < 0.05) and were correlated with a longer disease course. Four patients who failed letermovir prophylaxis lacked CMV-specific TCRs in their top clonotypes. The abundance of CMV-specific TCRs is a key predictor of refractory CMV reactivation post-Haplo-HSCT. Longitudinal TCR profiling offers a promising strategy for risk stratification, potentially guiding more personalized preemptive therapies. Not applicable.
Anti-thymocyte globulin (ATG) remains integral to graft-versus-host disease (GvHD) prophylaxis in allogeneic hematopoietic stem cell transplantation (HSCT), yet its optimal dosing is unresolved. Excessive immunosuppression can impair immune reconstitution and increase infection-related morbidity. This review summarizes evidence on the timing, dosing, and pharmacologic modeling of rabbit ATG (Thymoglobulin) in pediatric HSCT. Early investigations demonstrated that reduced ATG exposure, achieved through lower or earlier dosing, enhanced CD4 recovery and lowered viral reactivation rates, whereas higher exposure delayed immune recovery and increased severe infections. Pharmacokinetic and pharmacodynamic analyses identified absolute lymphocyte count and body weight and graft source as key determinants of ATG disposition, supporting the development of model-based dosing (MBD) strategies that individualize exposure according to patient and graft characteristics. Across multiple clinical studies, MBD achieved superior CD4 reconstitution, significantly reduced viral reactivation, and decreased chronic GvHD and graft failure without significantly increasing acute GvHD. Survival outcomes improved in patients reaching early CD4 recovery under individualized dosing. Optimal results were associated with high ATG exposure before transplantation and low exposure afterward. Collectively, current data indicate that MBD provides a rational, safe, and effective framework to balance GvHD prevention with immune recovery in pediatric HSCT. Further studies in peripheral blood and haploidentical transplantation settings are warranted to validate and expand this approach.
The umbilical cord and the amniotic membrane are a precious source of human mesenchymal stem cells (hMSCs), even though they are often discarded after the delivery. Due to their immunomodulatory and anti-inflammatory properties, hMSCs could be part of relevant strategies in the field of regenerative medicine. Additionally, they can be obtained from these tissues via a non-invasive and cost-effective process, overcoming ethical controversies. This study aims to propose protocol refinement to obtain hMSCs from the amnion and umbilical cord of healthy donors (utilizing limited and defined laboratory resources), and to compare and characterize these cells, thereby enabling future research on their properties. 30 women from "Paolo Giaccone" University Hospital of Palermo (Italy) were enrolled, according to the inclusion and exclusion criteria approved by the local Ethics Committee. A sample of umbilical cord and amnion was obtained from every patient and processed via an enzymatic or mechanical method. After refining the isolation protocol, hMSCs were characterized using flow cytometry, RT-qPCR, inducing a trilinear differentiation, and testing the formation of spheroids. This research shows reliable and practical methods to isolate hMSCs from birth tissues, validating them with extensive cell characterization. No direct association was observed between mothers' age and newborns' sex and the success rate in establishing hMSCs primary cultures, while a possible association between neonatal weight and the successful establishment of umbilical cord-derived cultures was found. Moreover, a difference in the adipogenic potential of the two hMSCs sources was highlighted. hMSCs have a relevant role in biomedicine, along with their derivatives, for their promising regenerative properties: this study aims to explore new insights to promote further research in this field.
Cardiovascular toxicity is a leading cause of drug attrition. Conventional animal models are constrained by cost, duration, and interspecies discrepancies. Organoids provide physiologically relevant alternatives for toxicity assessment. Here, we developed cardiovascular organoids (CVOs) by co-differentiating cardiomyocytes and vascular progenitor cells from human embryonic stem cells. CVOs demonstrated enhanced vascular and myocardial maturation relative to standalone cardiomyocyte or vascular organoids. In pharmacological assays, CVOs accurately recapitulated amiodarone bleomycin and cisplatin induced endothelial stress and captured dexamethasone and Vitamin C anti-inflammatory and antioxidant properties. CVOs generated results consistent with established toxicity profiles, exhibiting superior discriminatory capacity between positive and negative compounds. The prediction accuracy of the selected specific markers for all model compounds was about 90%. These findings confirm that CVOs reliably mirror in vitro cardiovascular toxicity profiles and represent a human-relevant platform for first-line screening of compounds.
Parkinson's disease (PD) is an age-related neurodegenerative disorder characterized by the progressive degeneration of dopaminergic neurons, with mitochondrial dysfunction playing a critical role in its pathogenesis. As a critical organelle in eukaryotic cells, mitochondria not only serve as the central hub for energy metabolism but also play a pivotal role in regulating inflammation and cell apoptosis. However, mitochondrial damage leads to the accumulation of reactive oxygen species (ROS), oxidative stress, and abnormal aggregation of α-synuclein (α-Syn), which collectively contribute to neuronal injury and cell death. Therefore, targeting mitochondrial dysfunction has emerged as a promising therapeutic approach for PD. Exosomes, as extracellular vesicles (EVs) secreted by cells, encapsulate various substances, including proteins, nucleic acids, and lipids. Exosomes exhibit inherent targeting ability, high stability, and low immunogenicity. Additionally, the molecular contents within exosomes can regulate the biological responses of recipient cells by modulating cellular functions and signaling pathways. These characteristics of exosomes have contributed to significant achievements in the treatment of neurodegenerative diseases over the years. This review explores the latest advancements regarding the impact of stem cell-derived exosomes on mitochondrial function in PD, focuses on the regulation of mitochondrial dysfunction in recipient cells by the exosomal cargo, and presents recent evidence that suggests mitochondrial components within exosomes may facilitate cellular recovery. The aim is to provide new insights into potential therapeutic strategies for PD and to highlight directions for future research.