Flow Cytometry Test Research Articles

Ordering and Utilization of Peripheral Blood Flow Cytometry in an Academic Medical Center

Abstract Introduction/Objective The American Society for Clinical Pathology and the American Board of Internal Medicine’s Choosing Wisely campaign have developed best practice utilization guidelines for laboratory testing. Wisconsin Diagnostic Laboratories and Medical College of Wisconsin leadership noticed an increase in inappropriate peripheral blood flow cytometry testing in the last two years. An intervention was developed to help reduce inappropriate testing requests. Methods/Case Report The laboratory implemented a clinical decision support tool in the electronic medical record system that looked at patient diagnosis, history of stem cell transplant, and recommendations from pathology to help improve utilization of peripheral blood flow cytometry testing. Based on patient history, flow cytometry testing would move forward, or an alternative order of a peripheral blood pathology smear review with reflex to flow cytometry was offered. Pathologists would reflex flow cytometry if abnormalities were present by light microscopy or predetermined reflexing criteria were met. Results (if a Case Study enter NA) 314 cases were included for analysis. The intervention reduced volumes of peripheral blood flow cytometry in patients without a history of hematologic malignancy by 49.1% (p=<0.001). Appropriate utilization increased from 47.0% in the pre-intervention period to 80.4% in the post intervention period (p=<0.001). Significant diagnosis rate increased from 42.5% to 50.0% (p=.261). This resulted in a cost savings of $12,232 for the health system during the intervention period. Conclusion Clinical decision support based utilization efforts provide strong and consistent interventions to reduce the unnecessary and inappropriate ordering of peripheral blood flow cytometry.

Diagnostic workup of triple hit lymphoma by fine needle aspiration

Abstract Introduction/Objective Triple-hit lymphomas (THL) represent a rare and aggressive subset of high-grade B-cell lymphomas characterized by a triad of translocations involving MYC, BCL2, and BCL6. Patients with THL face poor outcomes when treated with the standard diffuse large B-cell lymphoma protocol. Thus, intensified regimens have emerged as a frontline strategy for managing these patients. Therefore, accurate diagnosis and molecular subclassification of these lymphomas are essential for guiding therapeutic decisions for these patients. Here, we report a case study detailing the diagnostic assessment of THL utilizing limited diagnostic material obtained through palpation-guided fine-needle aspiration (FNA). Methods/Case Report A 58-year-old male presented with a rapidly enlarging neck mass, accompanied by worsening dysphagia, pain, and fatigue over the course of two months. Laboratory testing showed leukocytosis and imaging studies revealed a partially necrotic, 7.8 x 9.1 x 9.4 cm right jugular nodal mass. The patient was referred to otolaryngology for further evaluation, where FNA of the mass was performed by the cytopathology team. The aspirate was sent for cytology with cell block and flow cytometry. The Romanowsky stain revealed abundant, large, discohesive cells with prominent nucleoli and scant cytoplasm with an abundance of lymphoglandular bodies in the background. Immunohistochemistry (IHC) on the cell block demonstrated BCL-2, BCL-6, and MYC expression, and a Ki-67 proliferation index >95%. Concurrent flow cytometric analyses showed an aberrant B-cell population expressing CD19, CD20, CD22, CD23 and surface lambda light chain. Further fluorescence in situ hybridization (FISH) analysis performed on the cell block confirmed gene rearrangements in BCL2, BCL6 and MYC, thereby classifying this patient’s disease as THL. Results (if a Case Study enter NA) NA Conclusion Diagnosing THL typically demands sufficient tissue for histology, cytology, flow cytometry, IHC, and molecular testing. Herein, we showcase a notable example where the diagnostic evaluation of THL was accomplished using limited material obtained from FNA. This case highlights the efficacy of conducting comprehensive diagnostic studies even when tissue availability is constrained. Utilizing cytologic samples not only streamlines the diagnostic process but also minimizes the need for patients to undergo additional invasive procedures, thus potentially reducing delays in diagnosis and therapeutic intervention.

Advancing Diagnostic Accuracy and Quality of Patient Care Through the Implementation of a Flow Cytometry Quality Assurance Program

Abstract Introduction/Objective Flow cytometry immunophenotypic analysis plays an important role in the diagnosis, classification and disease monitoring of hematological neoplasms. However, interpretation of flow cytometry testing can be challenging, especially when using highly complex antibody panels. Thus exploring ways to improve diagnostic accuracy and in turn improving quality of patient care is needed. Methods/Case Report A flow cytometry quality assurance (QA) program was developed. Cases from various complex flow cytometry panels were randomly selected and cross-reviewed by a second pathologist on a daily basis. The outcomes of the QA review were categorized into three groups: complete agreement, minor discrepancy and major discrepancy. Each discrepancy, once identified, underwent a process of documentation, discussion and resolution. The reports were then modified in a timely manner and the clinical teams were notified of the changes. Recurrent issues and common pitfalls were reviewed and discussed at a weekly QA meeting. Here we summarize our 3-years’ experience with this program. Results (if a Case Study enter NA) In total, 6,166 cases were evaluated by the QA program; 6,028 (97.7%) cases showed complete concordance, 120 (2.0%) cases showed minor discrepancies and 18 (0.3%) cases showed major discrepancies. Antibody panels designed to evaluate mature and immature T-cell abnormalities showed the highest rate of discrepancy, 2.8%, whereas panels designed for evaluation of myelodysplastic syndromes showed the lowest discrepancy rate, 1.7%. When analyzing the trends of concordance and discrepancy over time, we found a statistically significant decrease in discrepancies over time, from 4% at the beginning of the QA program to 1.5% in the most recent time interval. Conclusion The overall concordance rate was 97.7%. The remaining 2.3% cases showed discrepancies that required a correction, underscoring the value and necessity of having a QA program. The overall discrepancy rates exhibited a gradual decline over time, indicative of the positive impact of the QA program on enhancing diagnostic competency and accuracy over time.

A 47-Year-old Asian female with tracheobronchial space-occupying lesions caused by chronic lymphocytic leukemia

Case presentationA 47-year-old Asian woman was admitted with worsening chest tightness and dyspnea for 10 days. Computed tomography (CT) showed changes in the trachea and segmental bronchi. Pulmonary function results suggestive of severe obstructive ventilatory dysfunction. Bronchoscopic findings showed the presence of multiple nodular lesions in the patient’s trachea and left and right main bronchi. Bronchoscopic biopsy, lymph node biopsy and bone marrow aspiration flow cytometry test results led to a definitive diagnosis of chronic lymphocytic leukemia (CLL), staged as Binet stage B and Rai stage 2.

Neuroprotective Role of AQP4 Knockdown in Astrocytes After Oxygen-Glucose Deprivation.

Aquaporin-4 (AQP4), predominantly expressed in astrocytes, has been implicated in the development of brain edema following ischemic events. However, its role in post-stroke neuroinflammation is not fully understood. Using a middle cerebral artery occlusion (MCAO) mouse model, we assessed AQP4's role in post-stroke inflammation. Brain tissue slices from male C57BL/6 mice were subjected to immunohistochemistry and western blot post-MCAO. Additionally, primary astrocytes were isolated for quantitative real-time PCR and immunofluorescence assays to evaluate the expression of inflammatory markers glial fibrillary acidic protein (GFAP) and AQP4. AQP4 modulation was achieved using viral knockdown and overexpression methods. Neuronal damage was assessed using flow cytometry and terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) tests in co-culture studies. MCAO mice exhibited a significant upregulation in GFAP. This reactive astrogliosis corresponded with an elevation in inflammatory markers. AQP4 expression responded to this inflammatory trend, peaking at 6 h after OGD and returning to baseline levels at 24 and 48 h. Co-culture experiments revealed that AQP4(+) astrocytes exacerbated injury in OGD-treated neurons, as evidenced by increased TUNEL positivity and apoptotic events. Conversely, AQP4(-) astrocytes appeared to have a protective effect. Knockdown of AQP4 resulted in reduced post-OGD inflammatory response, whereas AQP4 overexpression intensified the injury to neurons post-OGD. In vivo experiments also confirmed that AQP4 inhibitor TGN-020 reduced and overexpression of AQP4 increased behavioral abnormalities and brain infarcts. Our findings underscore AQP4's pivotal role in modulating post-stroke neuroinflammation. Targeting AQP4 may present a novel therapeutic avenue for mitigating ischemia-induced neuronal damage.

Determination of T cell response against XBB variants in adults who received either monovalent wild type inactivated whole virus or mRNA vaccine or bivalent WT/BA.4-5 COVID-19 mRNA vaccine as the additional booster

ObjectivesAs the SARS-CoV-2 virus evolves more rapidly than vaccines are updated, T cell immunity potentially confers protection against disease progression and death from new variants. In this study, we aimed to assess whether the current boosting vaccination schemes offer sufficient T cell protection against new SARS-CoV-2 variants. Methods. 292 adults who had received the second booster of either monovalent wild type vaccines (inactivated virus or mRNA) (cohort 1) or the second/third booster of bivalent WT/BA.4-5 mRNA vaccine (cohort 2) were recruited in Hong Kong. All participants showed no serological evidence of recent infection of SARS-CoV-2. Blood samples of each participant were collected before and one-month after receiving the booster. T cell and antibody responses were determined by flow cytometry and neutralization test respectively. Results. Among all vaccination strategies, only the adults who had received the bivalent vaccine as the third booster dose significantly elicited T cell responses to the XBB variant. Either monovalent or bivalent mRNA but not inactivated virus vaccine as the second/third booster induced antibody against different XBB variants. Conclusions. Receiving bivalent mRNA vaccine as the third booster is preferrable to induce both T cell and antibody responses against XBB.

Bio-synthesized AGS@AgNPs for wound healing, antioxidant support, antibacterial defense, and anticancer intervention

Slow wound healing and wound infections are significant challenges for burn patients. Biosynthesis of nanoparticles (NPs) using plant extracts offers a rapid, facile, and safe method for producing biocompatible NPs. In this study, Anethum graveolens seed (AGS) extract served as a masking and reducing agent for the synthesis of silver nanoparticles (AGS@AgNPs). Initially, the parameters influencing AGS@AgNPs synthesis, including silver nitrate concentration, reaction time, temperature, and pH, were optimized. Subsequently, AGS@AgNPs structural and biological characteristics were evaluated. Observation of the surface plasmon resonance (SPR) of the AGS@AgNPs at approximately 420 nm, accompanied by a color change of the suspension to dark brown, confirmed AGS@AgNPs synthesis. Analysis via X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FT-IR), dynamic light scattering (DLS), zeta potential, and transmission electron microscopy (TEM) confirmed the production of pure, homogeneous, spherical, and stable silver NPs with sizes ranging from 20 to 40 nm using Anethum graveolens extract. Antibacterial assays revealed significant activity against both Gram-positive and Gram-negative bacterial strains. Antioxidant assessments demonstrated that AGS@AgNPs at a concentration of 250 μg/ml exhibited 92% inhibition of DPPH free radicals and in FRAP test, A. graveolens seed extract and AGS@AgNPs reduced Fe3+ ions to Fe2+ by 48.7% and 73.1%, respectively. Investigation of anticancer properties against the lung cancer cell line (A-549) revealed an IC50 value of 242 μg/ml. The results of the flow cytometry test and lactate dehydrogenase (LDH) assay demonstrated the death of cancer cells. Moreover, wound healing assays demonstrated a significant acceleration in burn wound closure rates in rats on days 3, 7, and 14 following treatments with AGS@AgNPs. Overall, these findings highlight the favorable biological activities of AGS@AgNPs, suggesting their potential utility in nanomedicine applications.

Comparative Analysis of AML Classification Systems: Evaluating the WHO, ICC, and ELN Frameworks and Their Distinctions.

Comprehensive analyses of the molecular heterogeneity of acute myelogenous leukemia, AML, particularly when malignant cells retain normal karyotype, has significantly evolved. In 2022, significant revisions were introduced in the World Health Organization (WHO) classification and the European LeukemiaNet (ELN) 2022 guidelines of acute myeloid leukemia (AML). These revisions coincided with the inception of the first version of the International Consensus Classification (ICC) for AML. These modifications aim to improve diagnosis and treatment outcomes via a comprehensive incorporation of sophisticated genetic and clinical parameters as well as facilitate accruals to innovative clinical trials. Key updates include modifications to the blast count criteria for AML diagnosis, with WHO 2022 eliminating the ≥20% blast requirement in the presence of AML-defining abnormalities and ICC 2022 setting a 10% cutoff for recurrent genetic abnormalities. Additionally, new categories, such as AML with mutated TP53 and MDS/AML, were introduced. ELN 2022 guidelines retained risk stratification approach and emphasized the critical role of measurable residual disease (MRD) that increased the use of next-generation sequencing (NGS) and flow cytometry testing. These revisions underscore the importance of precise classification for targeted treatment strategies and improved patient outcomes. How much difference versus concordance these classifications present and the impact of those on clinical practice is a continuing discussion.

The effects of drone transportation on routine laboratory, immunohematology, flow cytometry and molecular analyses.

Transportation of medical samples between laboratories or hospital sites is typically performed by motorized ground transport. Due to the increased traffic congestions in urban environments, drone transportation has become an attractive alternative for fast shipping of samples. In accordance with the CLSI guidelines and the ISO 15189 standard, the impact of this transportation type on sample integrity and performance of laboratory tests must be thoroughly validated. Blood samples from 36 healthy volunteers and bacterial spiked urine samples were subjected to a 20-40 min drone flight before they were analyzed and compared with their counterparts that stayed on the ground. Effects on stability of 30 routine biochemical and hematological parameters, immunohematology tests and flow cytometry and molecular tests were evaluated. No clinically relevant effects on blood group typing, flow cytometry lymphocyte subset testing and on the stability of the multicopy opacity-associated proteins (Opa) genes inbacterial DNA nor on the number of Abelson murine leukemia viral oncogene homolog 1 (abl) housekeeping genesin human peripheral blood cells were seen. Forthreeofthe 30 biochemistry and hematology parameters a statistically significant difference was found: gamma-glutamyl transferase (gamma-GT), mean corpuscular hemoglobin (MCH) and thrombocyte count. A clinically relevant effect however was only seen for potassium and lactate dehydrogenase (LDH). Multi-rotor drone transportation can be used for medical sample transportation with no effect on the majority of the tested parameters, including flow cytometry and molecular analyses, with the exception of a limited clinical impact on potassium and LDH.

Unleashing the Impact of Exosomes Derived from Human Placental Mesenchymal Stem Cells (hPMSCs) on U-266 Myeloma Cell Line.

Multiple myeloma (MM) is a malignancy of plasma cells, terminally differentiated B cells, with complications like hypercalcemia, renal failure, anemia, and bone disease, which are also known as CRAB criteria. MM develops from monoclonal gammopathy of unknown significance (MGUS), a pre-malignant plasma cell dyscrasia. Over some time, MGUS has the potential to progress into smoldering multiple myeloma (SMM), which can evolve into MM. MM rarely progresses into plasma cell leukemia (PCL), a condition in which malignant plasma cells no longer stay in the bone marrow niche and circulate in the peripheral blood. In MM, various soluble factors play important roles, andinterleukin-6 has different vital roles. Interleukin-6, an inflammatory cytokine, has significant roles in the growth, survival, angiogenesis, metastasis, and apoptosis resistance in MM. Interleukin-6 is produced and secreted by both autocrine from myeloma cells and paracrine from bone marrow stromal cells. To tackle MM, various therapeutic approaches were applied over many years, and according to the results, most patients withMM can respond well to first-line treatment. However, the majority of patients may relapse as conventional treatment may not be curative. So, there is an urgent need for novel cell-based and cell-free therapeutic strategies, such as mesenchymal stem cell-based therapies and their products to offer new therapeutic strategies for MM. Materials and Methods: In the present study, we investigated the impacts of exosomes derived from human placental mesenchymal stem cells (hPMSCs) on apoptosis and interleukin-6 expression in a myeloma cell line, U-266, for the first time. hPMSCs were isolated from the human placenta and cultured in a DMEM medium. After characterizing the cells and acknowledging their identity, they underwent several passages and their supernatant was collected to harvest exosomes. The exosomes were isolated by ultracentrifugation and characterized by DLS and TEM, and their concentration was measured by BCA protein assay. U266 cells were treated with different concentrations of exosomes and then MTT and annexin/propidium iodide flow cytometry tests were performed to evaluate cell viability. Afterward, a real-time PCR test was performed to evaluate interleukin-6 gene expression. Results: According to our findings, treatment of U-266 cells with hPMSCS-derived exosomes led to the preservation of myeloma cells without changes in their cell cycle. Surprisingly, treatments did not hinder the expression of interleukin-6 in the myeloma cells. Conclusion: In MM patients, interleukin-6 pl ays different roles, and it is a desirable target to design new therapeutic strategies. To evaluate the effects of new therapeutic strategies, we designed and performed our study to estimate the effects of cell-free therapeutic strategy. In the present study, the impacts of hPMSCS-derived exosomes on the viability of MM cells and interleukin-6 gene expression were evaluated. The results showed that hPMSCS-derived exosomes resulted in the perseverance of myeloma cells without changes in the cell cycle. Furthermore, the interleukin-6 gene expression level showed no significant change.

Implementation of flow cytometry testing on rare matrix samples: Special considerations and best practices when the sample is unique or difficult to obtain.

The publication of Clinical and Laboratory Standards Institute's guideline H62 has provided the flow cytometry community with much-needed guidance on development and validation of flow cytometric assays (CLSI, 2021). It has also paved the way for additional exploration of certain topics requiring additional guidance. Flow cytometric analysis of rare matrices, or unique and/or less frequently encountered specimen types, is one such topic and is the focus of this manuscript. This document is the result of a collaboration subject matter experts from a diverse range of backgrounds and seeks to provide best practice consensus guidance regarding these types of specimens. Herein, we define rare matrix samples in the setting of flow cytometric analysis, address validation implications and challenges with these samples, and describe important considerations of using these samples in both clinical and research settings.

Investigating the effect of Fusobacterium nucleatum on the aggressive behavior of cancer-associated fibroblasts in colorectal cancer

Fusobacterium nucleatum, (F. nucleatum) as a known factor in inducing oncogenic, invasive, and inflammatory responses, can lead to an increase in the incidence and progression of colorectal cancer (CRC). Cancer-associated fibroblasts (CAF) are also one of the key components of the tumor microenvironment (TME), which lead to resistance to treatment, metastasis, and disease recurrence with their markers, secretions, and functions. This study aimed to investigate the effect of F. nucleatum on the invasive phenotype and function of fibroblast cells isolated from normal and cancerous colorectal tissue. F. nucleatum bacteria were isolated from deep periodontal pockets and confirmed by various tests. CAF cells from tumor tissue and normal fibroblasts (NF) from a distance of 10 cm of tumor tissue were isolated from 5 patients by the explant method and were exposed to secretions and ghosts of F. nucleatum. The expression level of two markers, fibroblast activation protein (FAP), and α-smooth muscle actin (α-SMA), and the amount of production of two cytokines TGF-β and IL-6 from fibroblast cells were measured by flow cytometry and ELISA test, respectively before and after exposure to different bacterial components. The expression of the FAP marker was significantly higher in CAF cells compared to NF cells (P < 0.05). Also, the expression of IL-6 in CAF cells was higher than that of NF cells. In investigating the effect of bacterial components on the function of fibroblastic cells, after comparing the amount of IL-6 produced between the normal tissue of each patient and his tumoral tissue under 4 treated conditions, it was found that the amount of IL-6 production from the CAF cells of patients in the control group, treated with heat-killed ghosts and treated with paraformaldehyde-fixed ghosts had a significant increase compared to NF cells (P < 0.05). Due to the significant increase in FAP marker expression in fibroblast cells of tumor tissue compared to normal tissue, it seems that FAP can be used as a very good therapeutic marker, especially in patients with high levels of CAF cells. Various components of F. nucleatum could affect fibroblast cells differentially and at least part of the effect of this bacterium in the TME is mediated by CAF cells.

Antifungal activity of propafenone on Candida spp. strains: interaction with antifungals and possible mechanism of action.

Introduction. The development of new antifungal drugs has become a global priority, given the increasing cases of fungal diseases together with the rising resistance to available antifungal drugs. In this scenario, drug repositioning has emerged as an alternative for such development, with advantages such as reduced research time and costs.Gap statement. Propafenone is an antiarrhythmic drug whose antifungal activity is poorly described, being a good candidate for further study.Aim. This study aims to evaluate propafenone activity against different species of Candida spp. to evaluate its combination with standard antifungals, as well as its possible action mechanism.Methodology. To this end, we carried out tests against strains of Candida albicans, Candida auris, Candida parapsilosis, Candida tropicalis, Candida glabrata and Candida krusei based on the evaluation of the MIC, minimum fungicidal concentration and tolerance level, along with checkerboard and flow cytometry tests with clinical strains and cell structure analysis by scanning electron microscopy (SEM).Results. The results showed that propafenone has a 50% MIC ranging from 32 to 256 µg ml-1, with fungicidal activity and positive interactions with itraconazole in 83.3% of the strains evaluated. The effects of the treatments observed by SEM were extensive damage to the cell structure, while flow cytometry revealed the apoptotic potential of propafenone against Candida spp.Conclusion. Taken together, these results indicate that propafenone has the potential for repositioning as an antifungal drug.

Is Feto-Maternal Transfusion after Cesarean Delivery Different in Singleton and Twin Pregnancy?

Background: The aim of the study was to investigate if feto-maternal transfusion was related to the size of the fetal-maternal interface, and, therefore, was larger in twin pregnancy in comparison with singleton pregnancy. Methods: Blood samples from women with singleton (n = 11), and monochorionic (n = 11) and dichorionic (n = 13) twin gestations were tested. Flow cytometry tests with hemoglobin F, glycophorin A, and hemoglobin F and carbonic anhydrase simultaneous staining were used to detect fetal red blood cells and maternal F cells. Results: In all cases, the volume of feto-maternal transfusion was estimated to be low. The highest rate of fetal red blood cells in the maternal circulation was observed in the blood of women with dichorionic twin gestations both before and after delivery. An increase in fetal red blood cells was observed after cesarean section in singletons and twins. The median rate of maternal F cells was 2.23% in singleton, 2.1% in monochorionic and 3.95% in dichorionic pregnancy. Conclusions: Feto-maternal transfusion during pregnancy may be related to the multiplicity and chorionicity of pregnancy.

Multiple Congenital Anomalies-Hypotonia-Seizures Syndrome 2 Caused by a Novel PIGA Variant Not Associated with a Skewed X-Inactivation Pattern

Germline variants in the phosphatidylinositol glycan class A (PIGA) gene, which is involved in glycosylphosphatidylinositol (GPI) biosynthesis, cause multiple congenital anomalies-hypotonia-seizures syndrome 2 (MCAHS2) with X-linked recessive inheritance. The available literature has described a pattern of almost 100% X-chromosome inactivation in mothers carrying PIGA variants. Here, we report a male infant with MCAHS2 caused by a novel PIGA variant inherited from his mother, who has a non-skewed pattern of X inactivation. Phenotypic evidence supporting the pathogenicity of the variant was obtained by flow-cytometry tests. We propose that the assessment in neutrophils of the expression of GPI-anchored proteins (GPI-APs), especially CD16, should be considered in cases with variants of unknown significance with random X-inactivation in carrier mothers in order to clarify the pathogenic role of PIGA or other gene variants linked to the synthesis of GPI-APs.

Advancing Diagnostic Accuracy and Quality of Patient Care Through the Implementation of a Flow Cytometry Quality Assurance Program.

Flow cytometry immunophenotypic analysis plays an important role in the diagnosis, classification, and disease monitoring of hematologic neoplasms. The interpretation of flow cytometry testing can be challenging. To explore ways to improve diagnostic accuracy and in turn enhance the quality of patient care. A flow cytometry quality assurance (QA) program was developed. Cases from various complex flow cytometry panels were randomly selected and cross-reviewed. The outcomes of the QA review were categorized into 3 groups: complete agreement, minor discrepancy, and major discrepancy. Each discrepancy underwent a process of documentation, discussion, and resolution. Here we summarize our 3 years of experience with this program. In total, 6166 cases were evaluated; 6028 cases (97.7%) showed complete concordance, 120 cases (2.0%) showed minor discrepancies, and 18 cases (0.3%) showed major discrepancies. Among the top 5 panels evaluated, the panel evaluating mature T-cell abnormalities showed the highest rate of discrepancy, whereas the panel for evaluation of myelodysplastic syndromes showed the lowest discrepancy rate. When analyzing the trends of concordance and discrepancy over time, we observed a statistically significant decrease in discrepancy rate over time, from 4% at the beginning of the 6-month period to 1.5% in the final 6-month period. The overall concordance rate was 97.7%. The remaining 2.3% of cases showed discrepancies that required a correction, underscoring the value and necessity of having a QA program. The overall discrepancy rates exhibited a gradual decline over time, indicative of the positive impact of the QA program on enhancing diagnostic competency and accuracy over time.

Genetically engineered electrospinning contributes to spinal cord injury repair by regulating the immune microenvironment.

Introduction: Spinal cord injury (SCI) is associated with microenvironment imbalance, thereby resulting in poor regeneration and recovery of the spinal cord. Gene therapy can be used to balance the inflammatory response, however target genes cannot exist in localized injured areas. Methods: A genetically engineered electrospun scaffold (GEES) to achieve long-term immunoregulation and nerve repair was constructed. By combining the microfluidic and electrospinning techniques, interleukin-10 plasmid (pIL10) was loaded into lipid nanoparticles (LNPs) (pIL10-LNP), which was encapsulated to the nerve growth factor (NGF). Immunofluorescence staining, qRT-PCR, ELISA, flow cytometry, and other tests were employed to comprehensively assess the role of GEES in modulating macrophage polarization and facilitating neural repair. Results: The results showed that the scaffold released >70% of the pIL10-LNP within 10 d and continued slow release within 30 d. In vitro cell experiments have demonstrated that GEES effectively stimulates macrophages to secrete anti-inflammatory cytokines and facilitates the differentiation of neural stem cells into neuronal cells. In rat T9 SCI model, the GEES significantly inhibited the inflammatory response in the acute and chronic phases of SCI by transfecting local tissues with slow-release pIL10-LNP to promote the release of the anti-inflammatory factor IL10, thereby creating a favorable microenvironment. With the addition of NGF, the repair and regeneration of nerve tissues was effectively promoted, and the post-SCI motor function of rats improved. Discussion: GEES can regulate post-SCI immune responses through continuous and effective gene delivery, providing a new strategy for the construction of electrospun scaffolds for nerve repair in gene therapy.

Synthesis and evaluation of novel mitochondria-targeted, water-soluble phenoxazine-porphyrins for efficient photodynamic therapy

In this study, we use cationic imidazole as the targeting group and phenoxazine as the electron donor, attaching phenoxazine to porphyrin via two different linking methods to synthesize two phenoxazine-porphyrin photosensitizers (PSs), P1 and P2, intended for photodynamic therapy (PDT) applications. Additionally, we synthesized a molecule, P3, that does not contain the cationic imidazole group, to serve as a control PS. We comprehensively evaluate the performance of P1 and P2 through steady-state and transient spectroscopy analysis, theoretical calculations, photooxidation experiments, and in vitro cell experiments. The results showed that P1 and P2 exhibit excellent water solubility, longer triplet state lifetimes (P1 at 200 μs, P2 at 170 μs), outstanding photostability, higher photooxidation rates and quantum yields of singlet oxygen (1O2). Notably, in the photooxidation experiment, P1's photooxidation rate is 1.1 times that of P2, and 1.5 times that of tetraphenyl zinc porphyrin (ZnTPP) without phenothiazine. This may be due to the larger Gibbs free energy difference between the singlet and triplet excited states in P1 (ΔGS-T of P1 is 0.87 eV, compared to 0.83 eV for P2), which results in a greater driving force for intersystem crossing (ISC) in P1 than in P2. The introduction of the cationic imidazole group in P1 and P2 significantly enhances water solubility and tumor cell uptake compared to P3, particularly showing higher intracellular accumulation and 1O2 generation capabilities in HepG2 tumor cells. Flow cytometry test results further confirmed the significant photocytotoxicity of P1 and P2, with a marked decrease in survival rates after light exposure, where the survival rate of P1 nanoparticles (NPs) dropped to 41.7 %, P2 NPs to 35.1 %, and P3 NPs to 75.0 %. The findings of this study provide crucial theoretical support for the design of new PSs.

Simple and rapid flow cytometry assay for the detection of malignant epithelial cells in body fluids.

Morphology is routinely used for detecting malignant cells in body fluids, but it has limitations. Recently, flow cytometry (FCM) is used as an effective tool for studying non-haematological malignancies. The main objective of this study is to standardize a simple and rapid FCM test for the detection of malignant epithelial cells in body fluids. Body fluids that had been processed for cytology/cytology and FCM were enrolled in this prospective study. We developed a fluorescent-labelled, monoclonal antibody panel composed of cell surface markers for this FCM assay. We compared the results of cytology/cell block and FCM. A total of 121 fluid samples were studied. Comparing the diagnostic performance of cytology/cell block and FCM, 52 (43%) cases were positive and 60 (49.5%) cases were negative for carcinoma cells by both techniques. Nine cases showed discordant results between the two techniques. Six cases were cytology+ but FCM- and three cases were FCM+ cytology-. Clustered Epithelial Cell Adhesion Molecule (EpCAM)-positive events with high scatter properties were definitive for positive diagnosis by FCM. We studied PD-L1 expression in 13 cases by FCM. Six cases were reported as false negative by this FCM assay due to hypocellularity and lack of EpCAM expression in malignant cells. This FCM assay is simple, easier and cost-effective yielding sensitive results with no inter-observer variability. FCM would become a valuable tool to complement routine diagnostic cytology and reduces misdiagnosis.

MCF-7 cell - derived exosomes were involved in protecting source cells from the damage caused by tributyltin chloride via transport function

Tributyltin chloride (TBTC) is a ubiquitous environmental pollutant with various adverse effects on human health. Exosomes are cell - derived signaling and substance transport vesicles. This investigation aimed to explore whether exosomes could impact the toxic effects caused by TBTC via their transport function. Cytotoxicity, DNA and chromosome damage caused by TBTC on MCF-7 cells were analyzed with CCK-8, flow cytometry, comet assay and micronucleus tests, respectively. Exosomal characterization and quantitative analysis were performed with ultracentrifugation, transmission electron microscope (TEM) and bicinchoninic acid (BCA) methods. TBTC content in exosomes was detected with Liquid Chromatography-Mass Spectrometry (LC-MS). The impacts of exosomal secretion on the toxic effects of TBTC were analyzed. Our data indicated that TBTC caused significant cytotoxicity, DNA and chromosome damage effects on MCF-7 cells, and a significantly increased exosomal secretion. Importantly, TBTC could be transported out of MCF-7 cells by exosomes. Further, when exosomal secretion was blocked with GW4869, the toxic effects of TBTC were significantly exacerbated. We concluded that TBTC promoted exosomal secretion, which in turn transported TBTC out of the source cells to alleviate its toxic effects. This investigation provided a novel insight into the role and mechanism of exosomal release under TBTC stress.