Analysis of CD8^+CD28^-T-suppressor cells in living donor liver transplant recipients

BACKGROUND:Human CD8 + CD28 - T-suppressor(Ts) cells have been considered to indicate a reduced need for immunosuppression in pediatric liver-intestine transplant recipients and recipients of deceased heart-kidney transplants.However,in adult-to-adult living donor liver transplantation(A-A LDLT)little information is available and the clinical significance is still unknown. METHODS:Flow cytometry was used to detect the population of CD8+CD28 -Ts cells present in peripheral blood in A-A LDLT recipients(n=31),patients with end- stage liver disease(n=24)and healthy controls(n=19). Meanwhile,we tested the graft function and trough levels of immunosuppression in recipients.The clinical and follow- up data of 31 transplant recipients were analyzed. RESULTS:Compared with diseased controls(P=0.007) and healthy individuals(P=0.000),a notable expansion of CD8 + CD28 - Ts cells was found in recipients of A-A LDLT.This was associated with graft function,levels of immunosuppression and rejection episodes. CONCLUSIONS:To monitor the CD8 + CD28 - Ts cells levels is important to evaluate the immune state of recipients. Meanwhile,it is also important to promote expansion of CD8+CD28 -Ts cells in recipients of A-A LDLT,not only to sustain good graft function and decrease the dosage of immunosuppressants,but also to reduce the occurrence of rejection.

Mechanical microenvironments of living cells: a critical frontier in mechanobiology

The fields of biomechanics and mechanobiology have long been predicated on the premise that mechanics governs cell behavior. However, over the past few years, a growing body of evidence has suggested that the mechanical environment very close to cells–the cell microenvironment–plays the most important role in determining what a cell feels and how it responds to tissue-level stimuli. To complicate matters further, cells can actively manipulate their microenvironments through pathways of recursive mechanobiological feedback. Harnessing this recursive behavior to understand and control cell physiology and pathophysiology is a critical frontier in the field of mechanobiology. Recent results suggest that the key to opening this scientific frontier to investigation and engineering application is understanding a different frontier: the physical frontier that cells face when probing their mechanical microenvironments.

Detection of cells by flow cytometry:Counting,imaging,and cell classification

The study of circulating cells in the blood stream is critical,as it covers many felds of biomed-icine,including immunology,cell biology,oncology,and reproductive medicine.In-viuo flowcytometry(IVFC)is a new tool to monitor and count cells in real time for long durations in theirnative biological environment.This review describes two main categories of IVFC,ie.,labeledand label-free IVFC.It focuses on label-free IVFC and introduces its technological developmentand related biological applications.Because cell recognition is the basis of flow cytometrycounting,this review also describes various methods for the classification of unlabeled cells,including the latest machine learning-based technologies.

Iron-Imprinted Single-Atomic Site Catalyst-Based Nanoprobe for Detection of Hydrogen Peroxide in Living Cells

Fe-based single-atomic site catalysts(SASCs),with the natural metalloproteases-like active site structure,have attracted widespread attention in biocatalysis and biosensing.Precisely,controlling the isolated single-atom Fe-N-C active site structure is crucial to improve the SASCs’performance.In this work,we use a facile ion-imprinting method(IIM)to synthesize isolated Fe-N-C single-atomic site catalysts(IIM-Fe-SASC).With this method,the ion-imprinting process can precisely control ion at the atomic level and form numerous well-defined single-atomic Fe-N-C sites.The IIM-Fe-SASC shows better peroxidase-like activities than that of non-imprinted references.Due to its excellent properties,IIM-Fe-SASC is an ideal nanoprobe used in the colorimetric biosensing of hydrogen peroxide(H_(2)O_(2)).Using IIM-Fe-SASC as the nanoprobe,in situ detection of H_(2)O_(2)generated from MDA-MB-231 cells has been successfully demonstrated with satisfactory sensitivity and specificity.This work opens a novel and easy route in designing advanced SASC and provides a sensitive tool for intracellular H_(2)O_(2)detection.

Fabrication of Silicon Carbide Quantum Dots via Chemical-Etching Approach and Fluorescent Imaging for Living Cells

A simple chemical-etching approach is used to prepare the silicon carbide quantum dots (QDs). The raw materials of silicon carbide (SiC) with homogeneous nanoparticles fabricated via self-propagating combustion synthesis are corroded in mixture etchants of nitric and hydrofluoric acid. After sonication and chromatography in the ultra-gravity field for the etched products, aqueous solution with QDs can be obtained. The microstructure evolution of raw particles and optical properties of QDs were measured. Different organophilic groups on the surface like carboxyl, oxygroup, and hyfroxy were produced in the process of etching. Fluorescent labeling and imaging for living cells of Aureobasidium pulluans were investigated. The results indicated that SiC QDs were not cytotoxic and could stably label due to the conjugation between organophilic groups of QDs and specific protein of cells, it can be utilized for fluorescent imaging and tracking cells with in vivo and long-term-distance. Moreover, mechanism and specificity of mark were also analyzed.

Real-time observation of integrin bending/unbending conformational changes on living cells

Introduction Integrins are a large family of adhesion molecules broadly expressed on the surface of a wide variety of cells as heterodimers. Binding of integrins to ligands provides not only mechanical anchorage for the cell to another cell or

Recent advances in optical techniques for dynamically probing cellular mechanobiology

Cellular mechanotransduction characterized by the transformation of mechanical stimuli into biochemical signals,represents a pivotal and complex process underpinning a multitude of cellular functionalities.This process is integral to diverse biological phenomena,including embryonic development,cell migration,tissue regeneration,and disease pathology,particularly in the context of cancer metastasis and cardiovascular diseases.Despite the profound biological and clinical significance of mechanotransduction,our understanding of this complex process remains incomplete.The recent development of advanced optical techniques enables in-situ force measurement and subcellular manipulation from the outer cell membrane to the organelles inside a cell.In this review,we delved into the current state-of-the-art techniques utilized to probe cellular mechanobiology,their principles,applications,and limitations.We mainly examined optical methodologies to quantitatively measure the mechanical properties of cells during intracellular transport,cell adhesion,and migration.We provided an introductory overview of various conventional and optical-based techniques for probing cellular mechanics.These techniques have provided into the dynamics of mechanobiology,their potential to unravel mechanistic intricacies and implications for therapeutic intervention.

Exact Traveling Wave Solutions for Nano-Solitons of Ionic Waves Propagation along Microtubules in Living Cells and Nano-Ionic Currents of MTs

In this work, the extended Jacobian elliptic function expansion method is used as the first time to evaluate the exact traveling wave solutions of nonlinear evolution equations. The validity and reliability of the method are tested by its applications to nano-solitons of ionic waves propagation along microtubules in living cells and nano-ionic currents of MTs which play an important role in biology.

The Electrochemical Impedance Behavior of the Living Cells Escherichia Coli

The semiconductive characteristics of clectron-transfrring proteins in living cells E coli was investigated by electrochemsical impedance spectroscopy(EIS). We found that the electrochemical impedance of living cells as a function of temprature followed the Arrhenius equation for semiconductors. This result shows a strong evidence to prove the semiconductive behavior of proteins

Establishing delivery route-dependent safety and efficacy of living biodrug mesenchymal stem cells in heart failure patients

BACKGROUND Mesenchymal stem cells(MSCs)as living biopharmaceuticals with unique properties,i.e.,stemness,viability,phenotypes,paracrine activity,etc.,need to be administered such that they reach the target site,maintaining these properties unchanged and are retained at the injury site to participate in the repair process.Route of delivery(RoD)remains one of the critical determinants of safety and efficacy.This study elucidates the safety and effectiveness of different RoDs of MSC treatment in heart failure(HF)based on phase II randomized clinical trials(RCTs).We hypothesize that the RoD modulates the safety and efficacy of MSCbased therapy and determines the outcome of the intervention.AIM To investigate the effect of RoD of MSCs on safety and efficacy in HF patients.METHODS RCTs were retrieved from six databases.Safety endpoints included mortality and serious adverse events(SAEs),while efficacy outcomes encompassed changes in left ventricular ejection fraction(LVEF),6-minute walk distance(6MWD),and pro-B-type natriuretic peptide(pro-BNP).Subgroup analyses on RoD were performed for all study endpoints.RESULTS Twelve RCTs were included.Overall,MSC therapy demonstrated a significant decrease in mortality[relative risk(RR):0.55,95%confidence interval(95%CI):0.33-0.92,P=0.02]compared to control,while SAE outcomes showed no significant difference(RR:0.84,95%CI:0.66-1.05,P=0.11).RoD subgroup analysis revealed a significant difference in SAE among the transendocardial(TESI)injection subgroup(RR=0.71,95%CI:0.54-0.95,P=0.04).The pooled weighted mean difference(WMD)demonstrated an overall significant improvement of LVEF by 2.44%(WMD:2.44%,95%CI:0.80-4.29,P value≤0.001),with only intracoronary(IC)subgroup showing significant improvement(WMD:7.26%,95%CI:5.61-8.92,P≤0.001).Furthermore,the IC delivery route significantly improved 6MWD by 115 m(WMD=114.99 m,95%CI:91.48-138.50),respectively.In biochemical efficacy outcomes,only the IC subgroup showed a significant reduction in pro-BNP by-860.64 pg/mL(WMD:-860.64 pg/Ml,95%CI:-944.02 to-777.26,P=0.001).CONCLUSION Our study concluded that all delivery methods of MSC-based therapy are safe.Despite the overall benefits in efficacy,the TESI and IC routes provided better outcomes than other methods.Larger-scale trials are warranted before implementing MSC-based therapy in routine clinical practice.

Lectin Conjugated Gold Nanoparticle-based Colorimetric Assay for Studying the Interactions of Antibiotic with Living Cell

The interactions of antibiotic with living cells were studied by lectin conjugated gold nanoparticles（GNPs） based colorimetric assay. Because of the high affinity of lectin for saccharides, the lectin conjugated GNPs are able to employ as indicators for monitoring the antibiotic induced changes of glycosyl complexes. The interactions of a well known antibiotic, tunicamycin, with two different cell lines, HeLa and SHG-44, were selected to establish this assay. In the presence of tunicamycin, the dose- and time-dependence on the decreasing of binding affinity of lectin conjugated GNPs with living cells were demonstrated by conventional microscopic and UV-Vis spectroscopic studies. The experimental result demonstrates that our approach can be used to identify antibiotic induced expression difference of glycosyl complexes on different cellular surfaces and determine drug activity quantitatively. For further confirming the capability of the GNP-based assay, the system was also studied by confocal laser scanning microscopy（CLSM） and classic flow cytometry（FCM） assay, and satisfactory results were obtained.

Research on Electric Impedance Spectroscopy of Living Cell Suspensions by a Chip with Microelectrodes

A microfabricated electrical impedance spectroscopy (EIS) chip with microelectrodes was developed.The substrate and the electrodes of the chip were made of glass and gold,respectively.The experimental results demonstrated that the EIS-chip could distinguish different solutions (physiological saline,culture medium,living cell suspension etc.) by scanning from 10Hz to 45kHz.A 6-element circuit model was used for fitting the real part and the imaginary part admittance curves of the living cell suspension.An actual circuit was also built and tested to verify the 6-element circuit model proposed.The micro-EIS chip has several advantages including the use of small sample volumes,high resolution and ease of operation.It shows good application prospects in the areas of cellular electrophysioiogy,drug screening and bio-sensors etc.

Expression of alpha smooth muscle actin in living donor liver transplant recipients

Recently,there have been reports from liver biopsies that showed the progression of liver fibrosis in liver transplant patients after the cessation of immunosuppression.Herein,we focused on activated hepatic stellate cells expressing alpha smooth muscle actin(α-SMA)to understand the correlation between immunosuppressant medication and liver fibrosis.The study enrolled two pediatric patients who underwent living donor liver transplantation and ceased immunosuppressant therapy.The number ofα-SMA-positive cells in the specimens obtained by liver biopsy from these two patients showed a three-fold increase compared with the number from four transplanted pediatric patients who were continuing immunosuppressant therapy.In addition,theα-SMA-positive area evaluated using the WinRooF image processing software program continued toincrease over time in three adult transplanted patients with liver fibrosis,and theα-SMA-positive area was increasing even during the pre-fibrotic stage in these adult cases,according to a retrospective review.Therefore,α-SMA could be a useful marker for the detection of early stage fibrosis.

Real-Time analysis of exosome secretion of single cells with single molecule imaging

The exosome-mediated response can promote or restrain the diseases by regulating the intracellular pathways,making the exosome become an effective marker for diagnosis and therapeutic control at the single-cell level.However,real-time analysis is hard to be achieved with traditional approaches because the exosomes usually need to be enriched by ultracentrifugation for a measurable signal-to-noise ratio.Recently developed label-free single-molecule imaging approaches may become an real-time quantitative tool for the analysis of single exosomes and related secretion behaviors of single living cells owing to their extreme sensitivity.

Live-cell imaging:new avenues to investigate retinal regeneration

Sensing and responding to our environment requires functional neurons that act in concert. Neuronal cell loss resulting from degenerative diseases cannot be replaced in humans, causing a functional impairment to integrate and/or respond to sensory cues. In contrast, zebrafish（Danio rerio） possess an endogenous capacity to regenerate lost neurons. Here, we will focus on the processes that lead to neuronal regeneration in the zebrafish retina. Dying retinal neurons release a damage signal, tumor necrosis factor α, which induces the resident radial glia, the Müller glia, to reprogram and re-enter the cell cycle. The Müller glia divide asymmetrically to produce a Müller glia that exits the cell cycle and a neuronal progenitor cell. The arising neuronal progenitor cells undergo several rounds of cell divisions before they migrate to the site of damage to differentiate into the neuronal cell types that were lost. Molecular and immunohistochemical studies have predominantly provided insight into the mechanisms that regulate retinal regeneration. However, many processes during retinal regeneration are dynamic and require live-cell imaging to fully discern the underlying mechanisms. Recently, a multiphoton imaging approach of adult zebrafish retinal cultures was developed. We will discuss the use of live-cell imaging, the currently available tools and those that need to be developed to advance our knowledge on major open questions in the field of retinal regeneration.

SmartFlare^(TM) is a reliable method for assessing mRNA expression in single neural stem cells

BACKGROUND One of the most challenging tasks of modern biology concerns the real-time tracking and quantification of mRNA expression in living cells.On this matter,a novel platform called SmartFlare^(TM) has taken advantage of fluorophore-linked nanoconstructs for targeting RNA transcripts.Although fluorescence emission does not account for the spatial mRNA distribution,NanoFlare technology has grown a range of theranostic applications starting from detecting biomarkers related to diseases,such as cancer,neurodegenerative pathologies or embryonic developmental disorders.AIM To investigate the potential of SmartFlare^(TM) in determining time-dependent mRNA expression of prominin 1(CD133)and octamer-binding transcription factor 4(OCT4)in single living cells through differentiation.METHODS Brain fragments from the striatum of aborted human fetuses aged 8 wk postconception were processed to obtain neurospheres.For the in vitro differentiation,neurospheres were gently dissociated with Accutase solution.Single cells were resuspended in a basic medium enriched with fetal bovine serum,plated on poly-L-lysine-coated glass coverslips,and grown in a lapse of time from 1 to 4 wk.Live cell mRNA detection was performed using SmartFlare^(TM) probes(CD133,Oct4,Actin,and Scramble).All the samples were incubated at 37°C for 24 h.For nuclear staining,Hoechst 33342 was added.SmartFlare^(TM) CD133-and OCT4-specific fluorescence signal was assessed using a semiquantitative visual approach,taking into account the fluorescence intensity and the number of labeled cells.RESULTS In agreement with previous PCR experiments,a unique expression trend was observed for CD133 and OCT4 genes until 7 d in vitro(DIV).Fluorescence resulted in a mixture of diffuse cytoplasmic and spotted-like pattern,also detectable in the contacting neural branches.From 15 to 30 DIV,only few cells showed a scattered fluorescent pattern,in line with the differentiation progression and coherent with mRNA downregulation of these stemness-related genes.CONCLUSION SmartFlare^(TM) appears to be a reliable,easy-to-handle tool for investigating CD133 and OCT4 expression in a neural stem cell model,preserving cell biological properties in anticipation of downstream experiments.

Lived Experience of Sickle Cell Patients during and after Crisis

Aims and Objectives: To understand the lived experience and needs of patients with sickle cell disease during and two weeks after their crisis and identify the obstacles faced by patients while they are in the hospital. Background: Although there is no specific data of a number of affected individuals with sickle cell disease in Oman based on their age, the majority of the Omani population are youth. This category of the population is either in their high school or working in the governmental or private sector in the country. When the most productive category of the population are getting frequently absent due to sickle cell crisis and complication of sickle cell crisis from their work, this leads to huge financial and human resource burden. Design: Phenomenology. Method: This qualitative descriptive research was conducted using face-to-face interviews based on an interview protocol. The interview protocol was developed by the authors based on a framework called domains of well-being. Twenty adult patients have been recruited for the interview after meeting inclusion criteria and were asked about their well-being and lived experience during sickle cell crisis. Authors used SRQR checklist in reporting the study. Results: Thirteen themes were identified related to patients’ lived experience and their well-being during sickle cell crisis. Patients reported physical, emotional, social, and spiritual alteration. Major themes that emerged are communication, medical team interpretation of genuine pain, Emotional disturbance during the crisis, What does this study contribute to the wider global clinical community? Nurses and doctors should use therapeutic communication when dealing with sickle cell patients. Nurses should establish rapport and trust with patients. In each health care setting, there should be a social worker to deal with patients with chronic illness social relationships between the patient, family and friends, post-discharge status, spiritual and Islamic activities, and physical abilities. Conclusion: Participants’ physical and psychological statuses were mostly affected. Moreover, participants experienced extreme emotional disturbance during a painful crisis. However, it was not well understood why participants experienced post sickle cell crisis symptoms which need to be further investigated. Relevance to Clinical Practice: Understanding the lived experience of sickle cell patients may help improve nursing and medical care provided to them and enhance better outcomes for patients. These findings made the nurses and physicians plan a strategy of treating sickle cell patients using a holistic approach.

3-82 Environmental Control of Live Cell Imaging System at Microbeam Facility

Live cell imaging has significantly changed our understanding to cell biology during the past 10 years. However, providing a suitable environment to keep cells heathy is still a challenge in live cell imaging experiments, and has great influence on the reliability of the experimental results. Many factors are needed to maintain cells healthy, such as temperature, pH, oxygen tension, CO2 and so on.

3-79 Live Cell Imaging Study of XRCC1 Kinetics at the

DNA strand breaks can lead to cell carcinogenesis or cell death if not repaired rapidly and efficiently. An online live cell imaging system was established at the high energy microbeam facility at the Institute of Modern Physics (IMP) to study early and fast cellular response to DNA damage after high linear energy transfer (LET) ion radiation. HT1080 cells expressing XRCC1-RFP were irradiated with single high energy nickel ions, and time-lapse images of the irradiated cells were obtained online.