The homeodomain (PHD) protein, PdbPHD3, confers salt tolerance by regulating squamosa promoter binding protein PdbSBP3 in Populus davidiana × P. bolleana.

Plant homeodomain (PHD) proteins are a family of zinc finger transcription factors that play roles in abiotic stress tolerance. However, their mechanisms in conferring salt tolerance are largely unknown. In this study, we characterized a PHD gene, PdbPHD3, from Populus davidiana × P. bolleana (Shanxin poplar) in response to salt stress. PdbPHD3 is a nuclear protein that is strongly induced by salt and abscisic acid (ABA) treatments. Overexpression of PdbPHD3 conferred salt tolerance, while silencing of PdbPHD3 increased sensitivity to salt. PdbPHD3 could enhance the activities of superoxide dismutase and peroxidase to reduce the abundance of reactive oxygen species, and enhance the osmotic potential by increasing the proline content. Chromatin immunoprecipitation sequencing (ChIP-seq) revealed that PdbPHD3 could bind to various DNA motifs, including the G-box ("CACGTG"), PALBOXAPC ("GGACGG"), and POLLEN1LELAT52 ("TTTCTT"). ChIP-seq combined with RNA sequencing identified a transcription factor gene, squamosa promoter binding protein 3 (PdbSBP3), which is directly regulated by PdbPHD3. Overexpression and silencing of PdbSBP3 improved and decreased salt tolerance, respectively. PdbSBP3 could also regulate all the physiological changes associated with salt tolerance, similar to PdbPHD3. These results suggest that PdbPHD3 confers salt tolerance by regulating PdbSBP3 to reduce ROS accumulation and increase proline content. Therefore, the regulatory axis of PdbPHD3 and PdbSBP3 confers salt tolerance in Shanxin poplar.

Intrathecal drug delivery systems for cancer pain: A retrospective analysis at a single tertiary medical center in China.

Objective: Intrathecal drug delivery systems (IDDS) have been clinically applied to treat refractory cancer-related pain for years. In this study, we demonstrate the current clinical practice and outcomes of IDDS for cancer pain management over a 3-year period at a single tertiary medical center in China. Methods: Patients who received IDDS implantation for cancer-related pain from 2021 to 2023 were identified. The electronic medical records of all eligible patients were retrospectively reviewed for study data including baseline characteristics, IDDS variables and postoperative clinical outcomes. Results: A total of 96 consecutive individuals were identified for analysis and complete follow-up information was available in 72 patients with a follow-up rate of 75 %. Patients were 49.0 % female with a mean age of 62 ± 10 years. The top five cancer types in IDDS population were lung (34.4 %), colorectal (17.7 %), pancreatic (11.5 %), breast (5.2 %) and liver (4.2 %) cancer. The median duration from cancer diagnosis to IDDS implantation was 24 months (interquartile range [IQR] 12-48 months) and from pain onset to IDDS implantation was 6 months (IQR 2-12 months). In addition, the median oral morphine equivalents (OME) daily dose was 290 mg (IQR 100-632 mg). Mean NRS was 7.5 ± 0.8 before implantation and decreased to an average of 3.0 ± 1.1 after IDDS (p < 0.001). Median overall survival after IDDS implantation was 3 months (IQR 2-6 months). Overall, 75 % family members of cancer patients were satisfied with IDDS in relieving cancer pain. Conclusion: IDDS therapy is a valuable option for patients suffering from cancer pain. More and more cancer pain patients receive IDDS to treat pain during the 3-year study period.

Analyzing post-endovascular treatment stroke prognosis with transcranial Doppler and quantitative electroencephalography.

OBJECTIVE: Despite successful recanalization following acute ischemic stroke, patients may have a poor prognosis. We investigated whether transcranial Doppler combined with quantitative electroencephalography can identify patients with a poor prognosis at an early stage. METHODS: Prospectively recruited patients with successful recanalization after endovascular treatment for acute ischemic stroke were assessed for prognosis at 90 days using the modified Rankin Scale. Clinical information and National Institute of Health Stroke Scale scores were recorded. Transcranial Doppler combined with quantitative electroencephalography was used to evaluate brain function. RESULTS: Of the 37 patients (63.5 ± 11.7 years) studied, 18 had a poor prognosis at 90 days (modified Rankin Scale >3). Multivariable analysis revealed that transcranial Doppler indicators of the pulsatility index of the unaffected side, quantitative electroencephalography indicators of the pairwise-derived Brain Symmetry Index, and National Institute of Health Stroke Scale score were independent prognostic indicators. Modeling indicated that combining these independent predictors yielded superior accuracy and net clinical benefit to any single variable. With the final predictive model presented as a nomogram, internal validation by bootstrap resampling showed good discrimination with a concordance index of 0.961. The calibration curve displayed good agreement of predicted and actual probabilities. INTERPRETATION: The nomogram prediction model combining transcranial Doppler with quantitative electroencephalography and National Institute of Health Stroke Scale scores can provide guidance for individualized risk prediction in patients with acute ischemic stroke after revascularization.

Exploring the Holistic Needs of People Living with Cancer in Care Homes: An Integrative Review.

Up to 26% of individuals residing in care homes are impacted by cancer. This underscores the importance of understanding the holistic needs of care home residents living with cancer to enhance the quality of their care. The primary objective of this integrative literature review was to consolidate the available evidence concerning the comprehensive needs of people living with cancer in care home settings, providing valuable insights into addressing their diverse needs. An integrative literature review was conducted using a systematic approach. Extensive searches were conducted in three databases, complemented by a thorough examination of grey literature and reference lists of relevant papers. The review focused on literature published between 2012 and 2022. The screening process involved two independent reviewers, with a third reviewer resolving any discrepancies. The review identified twenty research papers that met the eligibility criteria. These papers shed light on three primary themes related to the holistic needs of care home residents with cancer: physical, psychological, and end-of-life needs. Physical needs encompassed pain management, symptom control, and nutrition, while psychological needs involved social support, emotional well-being, and mental health care. End-of-life needs addressed end-of-life care and advance care planning. These themes highlight the multifaceted nature of cancer care in care homes and underscore the importance of addressing residents' holistic needs in a comprehensive and integrated manner. Improving care home education about cancer and integrating palliative and hospice services within this setting are vital for addressing the diverse needs of residents with cancer.

Vacuolar Sugar Transporter TMT2 Plays Crucial Roles in Germination and Seedling Development in Arabidopsis.

Vacuolar sugar transporters transport sugar across the tonoplast, are major players in maintaining sugar homeostasis, and therefore play vital roles in plant growth, development, and biomass yield. In this study, we analyzed the physiological roles of the tonoplast monosaccharide transporter 2 (TMT2) in Arabidopsis. In contrast to the wild type (WT) that produced uniform seedlings, the tmt2 mutant produced three types of offspring: un-germinated seeds (UnG), seedlings that cannot form true leaves (tmt2-S), and seedlings that develop normally (tmt2-L). Sucrose, glucose, and fructose can substantially, but not completely, rescue the abnormal phenotypes of the tmt2 mutant. Abnormal cotyledon development, arrested true leaf development, and abnormal development of shoot apical meristem (SAM) were observed in tmt2-S seedlings. Cotyledons from the WT and tmt2-L seedlings restored the growth of tmt2-S seedlings through micrografting. Moreover, exogenous sugar sustained normal growth of tmt2-S seedlings with cotyledon removed. Finally, we found that the TMT2 deficiency resulted in growth defects, most likely via changing auxin signaling, target of rapamycin (TOR) pathways, and cellular nutrients. This study unveiled the essential functions of TMT2 for seed germination and initial seedling development, ensuring cotyledon function and mobilizing sugars from cotyledons to seedlings. It also expanded the current knowledge on sugar metabolism and signaling. These findings have fundamental implications for enhancing plant biomass production or seed yield in future agriculture.

[Development of biosensors highly responsive to N-acetylneuraminic acid in Bacillus subtilis].

Bacillus subtilis is recognized as a generally-regarded-as-safe strain, and has been widely used in the biosynthesis of high value-added products, including N-acetylneuraminic acid (NeuAc) which is widely used as a nutraceutical and a pharmaceutical intermediate. Biosensors responding to target products are widely used in dynamic regulation and high-throughput screening in metabolic engineering to improve the efficiency of biosynthesis. However, B. subtilis lacks biosensors that can efficiently respond to NeuAc. This study first tested and optimized the transport capacity of NeuAc transporters, and obtained a series of strains with different transport capacities for testing NeuAc-responsive biosensors. Subsequently, the binding site sequence of Bbr_NanR responding to NeuAc was inserted into different sites of the constitutive promoter of B. subtilis, and active hybrid promoters were obtained. Next, by introducing and optimizing the expression of Bbr_NanR in B. subtilis with NeuAc transport capacity, we obtained an NeuAc-responsive biosensor with wide dynamic range and higher activation fold. Among them, P535-N2 can sensitively respond to changes in intracellular NeuAc concentration, with the largest dynamic range (180-20 245) AU/OD. P566-N2 shows a 122-fold of activation, which is 2 times of the reported NeuAc-responsive biosensor in B. subtilis. The NeuAc-responsive biosensor developed in this study can be used to screen enzyme mutants and B. subtilis strains with high NeuAc production efficiency, providing an efficient and sensitive analysis and regulation tool for biosynthesis of NeuAc in B. subtilis.

Multimodal Monitoring in Large Hemispheric Infarction: Quantitative Electroencephalography Combined With Transcranial Doppler for Prognosis Prediction.

Background: We aimed to explore whether transcranial Doppler (TCD) combined with quantitative electroencephalography (QEEG) can improve prognosis evaluation in patients with a large hemispheric infarction (LHI) and to establish an accurate prognosis prediction model. Methods: We prospectively assessed 90-day mortality in patients with LHI. Brain function was monitored using TCD-QEEG at the bedside of the patient. Results: Of the 59 (55.3 ± 10.6 years; 17 men) enrolled patients, 37 (67.3%) patients died within 90 days. The Cox regression analyses revealed that the Glasgow Coma Scale (GCS) score ≤ 8 [hazard ratio (HR), 3.228; 95% CI, 1.335-7.801; p = 0.009], TCD-terminal internal carotid artery as the offending vessel (HR, 3.830; 95% CI, 1.301-11.271; p = 0.015), and QEEG-a (delta + theta)/(alpha + beta) ratio ≥ 3 (HR, 3.647; 95% CI, 1.170-11.373; p = 0.026) independently predicted survival duration. Combining these three factors yielded an area under the receiver operating characteristic curve of 0.905 and had better predictive accuracy than those of individual variables (p < 0.05). Conclusion: TCD and QEEG complement the GCS score to create a reliable multimodal method for monitoring prognosis in patients with LHI.

Inducible Population Quality Control of Engineered Bacillus subtilis for Improved N-Acetylneuraminic Acid Biosynthesis.

Biosynthesis by microorganisms using renewable feedstocks is an important approach for realizing sustainable chemical manufacturing. However, cell-to-cell variation in biosynthesis capability during fermentation restricts the robustness and efficiency of bioproduction, hampering the industrialization of biosynthesis. Herein, we developed an inducible population quality control system (iPopQC) for dynamically modulating the producing and nonproducing subpopulations of engineered Bacillus subtilis, which was constructed via inducible promoter- and metabolite-responsive biosensor-based genetic circuit for regulating essential genes. Moreover, iPopQC achieved a 1.97-fold increase in N-acetylneuraminic acid (NeuAc) titer by enriching producing cell subpopulation during cultivation, representing 52% higher than that of previous PopQC. Strains with double-output iPopQC cocoupling the expression of double essential genes with NeuAc production improved production robustness further, retaining NeuAc production throughout 96 h of fermentation, upon which the strains cocoupling one essential gene expression with NeuAc production abolished the production ability.

Transcranial Doppler Combined With Quantitative Electroencephalography Brain Function Monitoring for Estimating the Prognosis of Patients With Posterior Circulation Cerebral Infarction.

Posterior circulation cerebral infarction (PCCI) can lead to deceased infratentorial cerebral blood flow (CBF) and metabolism. Neural activity is closely related to regional cerebral blood flow both spatially and temporally. Transcranial Doppler (TCD) combined with quantitative electroencephalography (QEEG) is a technique that evaluates neurovascular coupling and involves synergy between the metabolic and vascular systems. This study aimed to monitor brain function using TCD-QEEG and estimate the efficacy of TCD-QEEG for predicting the prognosis of patients with PCCI. We used a TCD-QEEG recording system to perform quantitative brain function monitoring; we recorded the related clinical variables simultaneously. The data were analyzed using a Cox proportional hazards regression model. Receiver-operating characteristic (ROC) curve analysis was used to evaluate the cut-off for the diastolic flow velocity (VD) and (delta + theta)/(alpha + beta) ratio (DTABR). The area under the ROC curve (AUROC) was calculated to assess the predictive validity of the study variables. Forty patients (aged 63.7 ± 9.9 years; 30 men) were assessed. Mortality at 90 days was 40%. The TCD indicators of VD [hazard ratio (HR) 0.168, confidence interval (CI) 0.047-0.597, p = 0.006] and QEEG indicators of DTABR (HR 12.527, CI 1.637-95.846, p = 0.015) were the independent predictors of the clinical outcomes. The AUROC after combination of VD and DTABR was 0.896 and showed better predictive accuracy than the Glasgow Coma Scale score (0.75), VD (0.76), and DTABR (0.781; all p < 0.05). TCD-QEEG provides a good understanding of the coupling mechanisms in the brain and can improve our ability to predict the prognosis of patients with PCCI.

Improving T-DNA Transfer to Tamarix hispida by Adding Chemical Compounds During Agrobacterium tumefaciens Culture.

Agrobacterium tumefaciens-mediated gene transfer is the most commonly used method for plant genetic engineering. However, during the period of A. tumefaciens culture, the effects of Agrobacterium culture before inoculation on genetic transformation are poorly understood. In the present study, we investigated the factors that affect the genetic transformation efficiency during Agrobacterium culture using Tamarix hispida as transgenic plant material. Agrobacterium treatment with spermidine (Spe), azacitidine (5-AzaC), dithiothreitol (DTT), or acetosyringone (AS) alone all significantly improved the efficiency of T-DNA transfer. Treatment with 5-AzaC reduced DNA methylation in Agrobacterium to induce the expression of virulence (vir) family genes, including virA, virB1, virC1, virD2, virD4 virE2, and virG. Spe treatment significantly induced the expression of all the studied genes, including virA, virB1, virC1, virD1, virD2, virD4, virE2, and virG. DTT treatment decreased reactive oxygen species accumulation. AS treatment activated the expression of the genes virA, virB1, virC1, virD1, virD2, virD4 and virG. All these effects resulted in increased T-DNA transfer. Additionally, combined Spe, 5-AzaC, DTT, and AS treatment improve Agrobacterium infection to a greater extent compared with their use alone, increasing T-DNA transfer by more than 8-fold relative to no treatment. Therefore, to improve genetic transformation, pretreatment of Agrobacterium during the culture period is important for improving genetic transformation efficiency.

Titrating bacterial growth and chemical biosynthesis for efficient N-acetylglucosamine and N-acetylneuraminic acid bioproduction.

Metabolic engineering facilitates chemical biosynthesis by rewiring cellular resources to produce target compounds. However, an imbalance between cell growth and bioproduction often reduces production efficiency. Genetic code expansion (GCE)-based orthogonal translation systems incorporating non-canonical amino acids (ncAAs) into proteins by reassigning non-canonical codons to ncAAs qualify for balancing cellular metabolism. Here, GCE-based cell growth and biosynthesis balance engineering (GCE-CGBBE) is developed, which is based on titrating expression of cell growth and metabolic flux determinant genes by constructing ncAA-dependent expression patterns. We demonstrate GCE-CGBBE in genome-recoded Escherichia coli Δ321AM by precisely balancing glycolysis and N-acetylglucosamine production, resulting in a 4.54-fold increase in titer. GCE-CGBBE is further expanded to non-genome-recoded Bacillus subtilis to balance growth and N-acetylneuraminic acid bioproduction by titrating essential gene expression, yielding a 2.34-fold increase in titer. Moreover, the development of ncAA-dependent essential gene expression regulation shows efficient biocontainment of engineered B. subtilis to avoid unintended proliferation in nature.

Pain Mechanism in Rheumatoid Arthritis: From Cytokines to Central Sensitization.

Pain is the most common symptom in patients with rheumatoid arthritis (RA). Although in recent years, through the implementation of targeted treatment and the introduction of disease-modifying antirheumatic drugs (DMARDs), the treatment of RA patients has made a significant progress, a large proportion of patients still feel pain. Finding appropriate treatment to alleviate the pain is very important for RA patients. Current research showed that, in addition to inflammation, RA pain involves peripheral sensitization and abnormalities in the central nervous system (CNS) pain regulatory mechanisms. This review summarized the literature on pain mechanisms of RA published in recent years. A better understanding of pain mechanisms will help to develop new analgesic targets and deploy new and existing therapies.

Development and optimization of N-acetylneuraminic acid biosensors in Bacillus subtilis.

Transcriptional factor (TF)-based metabolite-responsive biosensors are important tools for screening engineered enzymes with desired properties and for the dynamic regulation of biosynthetic pathways. However, TF-based biosensor construction is often constrained by undesired effects of TF-binding site sequence insertion on gene expression and unpredictable optimal TF expression levels. In the present study, a stepwise TF-based biosensor construction approach was developed using an N-acetylneuraminic acid (NeuAc) biosensor for Bacillus subtilis, as a case study. Specifically, 12 promoters with various strengths were selected as the first promoter library. Next, binding site sequences for the NanR were inserted into various positions of the selected promoter sequences to develop the second promoter library, resulting in 6 engineered promoters containing TF-binding site sequences (NanO), without major effects on promoter strength. NanR expression cassettes with different expression levels were further integrated to construct the biosensor library, yielding 9 NeuAc biosensors with efficient repression in the absence of NeuAc. Finally, biosensor activation was characterized by testing fold changes in expression levels of the green fluorescent protein reporter in the presence of NeuAc in vivo, which revealed 61-fold activation when NeuAc was present. The NeuAc biosensor developed in this study can be used for screening engineered enzymes for enhanced NeuAc biosynthesis in B. subtilis.

Molecular Characterization of Magnesium Chelatase in Soybean [Glycine max (L.) Merr.].

Soybean (Glycine max) seed yields rely on the efficiency of photosynthesis, which is poorly understood in soybean. Chlorophyll, the major light harvesting pigment, is crucial for chloroplast biogenesis and photosynthesis. Magnesium chelatase catalyzes the insertion of Mg2+ into protoporphyrin IX in the first committed and key regulatory step of chlorophyll biosynthesis. It consists of three types of subunits, ChlI, ChlD, and ChlH. To gain a better knowledge of chlorophyll biosynthesis in soybean, we analyzed soybean Mg-chelatase subunits and their encoding genes. Soybean genome harbors 4 GmChlI genes, 2 GmChlD genes, and 3 GmChlH genes, likely evolved from two rounds of gene duplication events. The qRT-PCR analysis revealed that GmChlI, GmChlD, and GmChlH genes predominantly expressed in photosynthetic tissues, but the expression levels among paralogs are different. In silicon promoter analyses revealed these genes harbor different cis-regulatory elements in their promoter regions, suggesting they could differentially respond to various environmental and developmental signals. Subcellular localization analyses illustrated that GmChlI, GmChlD, and GmChlH isoforms are all localized in chloroplast, consistent with their functions. Yeast two hybrid and bimolecular fluorescence complementation (BiFC) assays showed each isoform has a potential to be assembled into the Mg-chelatase holocomplex. We expressed each GmChlI, GmChlD, and GmChlH isoform in Arabidopsis corresponding mutants, and results showed that 4 GmChlI and 2 GmChlD isoforms and GmChlH1 could rescue the severe phenotype of Arabidopsis mutants, indicating that they maintain normal biochemical functions in vivo. However, GmChlH2 and GmChlH3 could not completely rescue the chlorotic phenotype of Arabidopsis gun5-2 mutant, suggesting that the functions of these two proteins could be different from GmChlH1. Considering the differences shown on primary sequences, biochemical functions, and gene expression profiles, we conclude that the paralogs of each soybean Mg-chelatase subunit have diverged more or less during evolution. Soybean could have developed a complex regulatory mechanism to control chlorophyll content to adapt to different developmental and environmental situations.

Platelet-mediated adhesion facilitates leukocyte sequestration in hypoxia-reoxygenated microvessels.

Leukocyte transendothelial migration and sequestration are two distinct outcomes following leukocyte adhesion to endothelium during ischemia-reperfusion injury, in which platelets may play a pivotal role. In the present study, we established an in vitro hypoxia-reoxygenation model to mimic ischemia-reperfusion injury and found platelet pre-incubation significantly increased leukocyte adhesion to endothelial cells after hyoxia-reoxygenation (over 67%). Blockade of endothelial-cell-expressed adhesion molecules inhibited leukocyte direct adhesion to endothelial cells, while platelet-mediated leukocyte adhesion was suppressed by blockade of platelet-expressed adhesion molecules. Further experiments revealed platelets acted as a bridge to mediate leukocyte adhesion, and platelet-mediated adhesion was the predominant pattern in the presence of platelets. However, platelet pre-incubation significantly suppressed leukocyte transendothelial migration after hypoxia-reoxygenation (over 31%), which could be aggravated by blockade of endothelial-cell-expressed adhesion molecules, but alleviated by blockade of platelet- expressed adhesion molecules. This would indicate that platelet-mediated adhesion disrupted leukocyte transendothelial migration. An in vivo mesenteric ischemia-reperfusion model demonstrated leukocyte transfusion alone caused mild leukocyte adhesion to reperfused vessels and subsequent leukocyte infiltration, while simultaneous leukocyte and platelet transfusion led to massive leukocyte adhesion and sequestration within reperfused microvessels. Our studies revealed platelets enhanced leukocyte adhesion to endothelial cells, but suppressed leukocyte transendothelial migration. Overall, this leads to leukocyte sequestration in hypoxia-reoxygenated microvessels.

Reaction-Based "Off-On" Fluorescent Probe Enabling Detection of Endogenous Labile Fe(2+) and Imaging of Zn(2+)-induced Fe(2+) Flux in Living Cells and Elevated Fe(2+) in Ischemic Stroke.

Fluorogenic sensors capable of spatiotemporally detecting Fe(2+) in biological systems are highly valuable in the study of iron biology. Toward this end, a new "off-on" Fe(2+)-selective fluorescent probe has been developed by incorporating an Fe(2+)-induced N-O cleavage of acylated hydroxylamine moiety into the naphthalimide fluorophore. The probe displays facile response (within 15 min) and good selectivity toward Fe(2+) with >27-fold enhancement of fluorescence intensity and high sensitivity of as low as 0.5 µM with a noticeable 3-fold fluorescence enhancement. These features of the probe have been transformed into in the convenient detection of endogenous, basal level of labile Fe(2+) pools in living cells. Furthermore, we have demonstrated the capacity of the probe for the studies of important Fe(2+) related biological functions. It can respond to the Zn(2+)-induced Fe(2+) flux, an important event observed in stroke, and facilely detect the elevated level of Fe(2+) in the brain tissue of a rat undergoing ischemic stroke at the ischemic site.

Photo-triggered fluorescent theranostic prodrugs as DNA alkylating agents for mechlorethamine release and spatiotemporal monitoring.

We describe a new theranostic strategy for selective delivery and spatiotemporal monitoring of mechlorethamine, a DNA alkylating agent. A photo-responsive prodrug is designed and composed of a photolabile o-nitrophenylethyl group, a DNA alkylating mechlorethamine drug and a coumarin fluorophore. Masking of the "N" in mechlorethamine in a positively charged state in the prodrug renders it inactive, non-toxic, selective and non-fluorescent. Indeed, the stable prodrug shows negligible cytotoxicity towards normal cells with and without UV activation and is completely non-fluorescent. However, upon photo-irradiation, the active mechlorethamine is released and induces efficient DNA cross-links, accompanied by a strong fluorescence enhancement (152 fold). Furthermore, DNA cross-linking activity from the release can be transformed into anticancer activity observed in in vitro studies of tumor cells. Importantly, the drug release progress and the movement can be conveniently monitored by fluorescence spectroscopy. The mechanistic study proves that the DNA cross-linking activity is mainly due to the release of DNA alkylating mechlorethamine. Altogether, the studies show the power of the theranostic strategy for efficient therapy in cancer treatment.

A FRET-based ratiometric fluorescent and colorimetric probe for the facile detection of organophosphonate nerve agent mimic DCP.

A FRET ratiometric fluorescent probe enabling a fast and highly sensitive response to OP nerve agent mimic DCP within 1 min and with as low as 0.17 ppm concentration detection limit has been developed. Moreover, the probe exhibits noticeable color changes under UV light and even with the naked eye. It is also demonstrated that it can detect both liquid and gas nerve agents.

[Effects of platelets on the adhesion between leukocytes and liver sinusoidal endothelium cells as well as on the transendothelial migration of leukocytes undergoing hypoxia-reoxygenation].

OBJECTIVE: To investigate the effects of platelet on intercellular adhesion between leukocyte and liver sinusoidal endothelial cell(LSEC) and the transendothelial migration under the hypoxia-reoxygenation condition, as well as the role of relevant adhesion molecules. METHOD: LSEC was cultured for 24 hours under hypoxia condition and then reoxygenated for 2 hours (hypoxia-reoxygenation, HR). This hypoxia-reoxygenation model was used to simulate the clinical liver ischemia-reperfusion injury process (IRI). Platelets and leukocytes were labeled with fluorescence dye, and then the adhesion was detected by fluorescence microscope, fluorescence plate reader and laser scanning confocal microscope. Antibody blockage experiment was used to analyze the relevant adhesion molecules. RESULTS: The adhesion between platelets and LSEC was increased significantly after HR. The fluorescence intensity of adherent platelets increased from 142.10 ± 7.53 to 289.17 ± 20.00(P < 0.01). After H-R treatment and the addition of platelets, the number of adherent leukocytes increased markedly, and a significant statistical difference (360.71 ± 23.47 and 186.39 ± 17.96, P < 0.01) was found in comparing with the platelet deficient group. These adhesion processes could be blocked respectively by anti-GPIb, anti-GPIIb, anti-GPIIIa, anti-P-selectin, anti-CD31, anti-ICAM-1, anti-VCAM-1 and anti-ELAM-1. Confocal microscopy showed that platelets located between leukocytes and LSEC, and mediated their adhesion process. However, the adhesion of platelets to LSEC decreased the transendothelial migration of leukocytes (227.79 ± 16.51 and 167.27 ± 10.92, P < 0.05). CONCLUSION: During ischemia-reperfusion condition platelets adhere to the surface of LSEC, and then further mediate more adhesion processes between leukocytes and endothelial cells, as well as inhibit the transendothelial migration of leukocytes. The consequence is that large numbers of leukocytes were sequestrated within hepatic sinus, and deteriorate liver ischemia-reperfusion injury.

A fluorescent probe capable of detecting H2S at submicromolar concentrations in cells.

A new internal charge transfer (ICT) fluorescent probe for highly selective and sensitive monitoring of H(2)S has been developed. The design takes advantage of the facile reduction of non-fluorescent hydroxyamine naphthalimide by H(2)S to highly fluorescent amine naphthalimide. It has been demonstrated that the probe is able to detect H(2)S at submicromolar concentrations in cells.