Effect of the Content and Type of Binders on Electrochemical Performance of Silicon Anode Materials.

Binders play a critical role in stabilizing the cycling performance of silicon (Si) materials by protecting Si particles from pulverization in cycling processes. Poly(acrylic acid) (PAA) and carboxymethyl cellulose (CMC) are the two most studied binders for Si electrodes, of which PAA is an elastic polymer and CMC is a rigid polymer. Starting with the elastic PAA, we study the effect of binder content on the cycling performance of Si electrodes. It is found that regardless of the particle size of Si materials, there is an optimal binder content between 20% and 25% for the cycling stability of the Si electrodes. Compared with the elastic PAA, the rigid CMC binder causes Si electrodes lower capacity and faster capacity fading. AC-impedance analysis reveals that the lower capacity is due to a higher grain boundary resistance (Rgb) of the CMC-coated electrodes, which induces a high charge-transfer resistance (Rct) and consequently high polarization. In the discharging process of Li/Si cells, the high polarization triggers early termination, resulting in underutilization of the Si active material. On the other hand, the fast capacity fading of the CMC-coated electrodes is attributed to the inferior ability of the rigid binder to protect Si particles from pulverization.

[Clinical, imaging and pathological and molecular characteristics of simple bone cyst].

Objective: To investigate the radiologic, pathologic, and molecular features of simple bone cysts (SBC), and their differential diagnoses. Methods: Fourteen cases of SBC were collected at the Department of Pathology, the First Affiliated Hospital of Nanjing Medical University from 2017 to 2022, and fluorescence in situ hybridization (FISH) was performed for retrospective analysis. Results: There were 14 patients, including 7 females and 7 males, with age range of 7 to 45 (median 29) years. The most common complaint was pain, including 4 cases with pathological fracture and 5 with history of previous trauma. The tumor size ranged from 3.4 to 13.5 (median 5.6) cm. The lesion involved the femur (n=4), humerus (n=5) and iliac bone (n=5). Radiologic diagnoses included SBC, aneurysmal bone cyst, and giant cell tumor of the bone or its combination with aneurysmal bone cyst-like region and fibrous dysplasia. Histologically, the cyst walls of the lesions were composed of fibrous tissue, fibrin-like collagen deposits, bone-like matrix and occasional woven bone. The lesional cells were spindled to ovoid, with scattered osteoclast-like giant cells, foamy histiocytes, hemosiderin deposits and cholesterol clefts. In 6 cases there were nodular fasciitis-like areas. Immunohistochemically, the spindled to ovoid cells were positive for SMA, EMA and SATB2 in varying degrees. FISH detection was performed in all 14 cases and EWSR1/FUS rearrangement were found in 9 cases. One case of FUS::NFATC2 fusion was detected by next-generation sequencing. Nine cases of SBC with the rearrangement were more cellular, and there were more mitotic figures in the recurrent FUS::NFATC2 fusion tumor. Clinical follow-up was obtained in all 14 cases with the time ranging from 5 to 105 (mean 46) months. Amongst them, the tumor with FUS::NFATC2 rearrangement had local recurrence twice after the first local excision, but had no more recurrence or metastasis 34 months after the subsequent segmental resection. The other 13 cases had no recurrence. Conclusions: EWSR1 or FUS rearrangement is most commonly identified in SBC, suggesting that SBC might be a neoplastic disease. In cases where the radiologic appearance and histomorphology are difficult to differentiate from aneurysmal bone cyst, FISH detection can aid in the definitive diagnosis.

[Imaging study on determining the rationality of atlantoaxial fixation angle based on the ratio of line segments between anatomical markers on lateral X-ray films].

Objective: To propose a method to determine the unreasonableness of the fixed angle in posterior atlantoaxial fusion surgery based on the ratio of line segments between anatomical landmarks of the atlantoaxial joint. Methods: A cross-sectional study was conducted. According to the inclusion criteria, a screening was performed on the database of asymptomatic volunteers who had full-spine lateral X-ray films taken at the Second Affiliated Hospital of Wenzhou Medical University from May 2016 to May 2021. A total of 207 volunteers were included, comprising 98 males with an age of (40.68±13.87) years and 109 females with an age of (42.64±14.45) years. On the lateral X-ray film, a line (L) parallel to the posterior margin of the odontoid process was drawn at the posterior edge of the lower articular surface of the axis (a), intersecting the atlas at points b, c, and d. The line segments ab, bd, bc, and the C1-C2 angle were measured, and the ratios of bd/ab and bc/ab were calculated. The ability of bd/ab and bc/ab to predict the unreasonable fixed angle of the atlantoaxial joint (≥22°) was analyzed by receiver operating characteristic (ROC) curve analysis in both male and female. The areas under the ROC curves (AUC) were calculated, and the performance of the two prediction methods was compared using the Delong's test. The cutoff value for distinguishing the unreasonableness of the C1-C2 angle and the sensitivity and specificity were calculated. Results: The ROC curve analysis in the male group showed that the AUC of bc/ab for predicting the unreasonable C1-C2 angle was 0.791 (95%CI: 0.696-0.867, P<0.001), with a cutoff value of 0.449, sensitivity of 97.3%, and specificity of 70.0%. The performance was significantly better than that of bd/ab (cutoff value 1.100, AUC=0.532, 95%CI: 0.428-0.634, sensitivity 26.3%, specificity 83.3%, P<0.001). The ROC curve analysis in the female group showed that the AUC of bc/ab for predicting the unreasonable C1-C2 angle was 0.804 (95%CI: 0.745-0.852, P<0.001), with a cutoff value of 0.488, sensitivity of 90.5%, and specificity of 58.6%. The performance was significantly better than that of bd/ab (cutoff value 0.960, AUC=0.687, 95%CI: 0.624-0.748, sensitivity 90.5%, specificity 44.8%, P=0.041). Conclusions: The bc/ab value can be used as an effective indicator to predict the unreasonable C1-C2 angle in posterior atlantoaxial fusion surgery with high diagnostic accuracy. The cutoff value for males is<0.449, and for females is<0.488.

Nrf2 sensitizes ferroptosis through l-2-hydroxyglutarate-mediated chromatin modifications in sickle cell disease.

Sickle cell disease (SCD) is a chronic hemolytic and systemic hypoxia condition with constant oxidative stress and significant metabolic alterations. However, little is known about the correlation between metabolic alterations and the pathophysiological symptoms. Here, we report that Nrf2, a master regulator of cellular antioxidant responses, regulates the production of the metabolite l-2-hydroxyglutarate (L2HG) to mediate epigenetic histone hypermethylation for gene expression involved in metabolic, oxidative, and ferroptotic stress responses in SCD. Mechanistically, Nrf2 was found to regulate the expression of L2HG dehydrogenase (L2hgdh) to mediate L2HG production under hypoxia. Gene expression profile analysis indicated that reactive oxygen species (ROS) and ferroptosis responses were the most significantly affected signaling pathways after Nrf2 ablation in SCD. Nrf2 silencing and L2HG supplementation sensitize human sickle erythroid cells to ROS and ferroptosis stress. The absence of Nrf2 and accumulation of L2HG significantly affect histone methylation for chromatin structure modification and reduce the assembly of transcription complexes on downstream target genes to regulate ROS and ferroptosis responses. Furthermore, pharmacological activation of Nrf2 was found to have protective effects against ROS and ferroptosis stress in SCD mice. Our data suggest a novel mechanism by which Nrf2 regulates L2HG levels to mediate SCD severity through ROS and ferroptosis stress responses, suggesting that targeting Nrf2 is a viable therapeutic strategy for ameliorating SCD symptoms.

Clinical comparison of superior thyroid artery perforator flap and sternocleidomastoid myocutaneous flap for intraoral reconstruction.

The aim was to evaluate the techniques and outcomes of superior thyroid artery perforator flaps (STAPF) for intraoral reconstruction and to compare them with those of the sternocleidomastoid myocutaneous flap (SCMMF). The cases of 43 patients who underwent reconstruction with either a SCMMF or STAPF for the repair of a medium-sized intraoral defect, between January 2013 and December 2020, were reviewed retrospectively. Although both flaps are based on the superior thyroid artery, their specific harvesting techniques largely differ. All SCMMF (n = 23) were superiorly-based rotational flaps with myocutaneous designs. The STAPF cases (n = 20) included 18 septocutaneous flaps and two chimeric flaps. The flap size was larger in the STAPF group (P = 0.008), while incomplete level IIB dissection (oncological safety) was more frequent in the SCMMF group (P = 0.002). The flap necrosis rate was lower in the STAPF group (STAPF 15% vs SCMMF 34.8%, though this was not statistically significant). Cox multivariate analysis showed that the postoperative flap outcome (total flap necrosis vs flap survival; hazard ratio 27, 95% confidence interval 2.149-336.05; P = 0.001) and complications (excluding fistula) (hazard ratio 14, 95% confidence interval 1.314-142.767; P = 0.029) were associated with overall patient survival. Both speech (P < 0.001) and neck mobility (P < 0.001) functions were superior with STAPF reconstruction. Compared with the traditional SCMMF, the STAPF was found to have a lower necrosis rate with uncompromised oncological safety during harvesting. The STAPF is a good alternative for the repair of medium-sized head and neck defects.

[Imaging study on the safety of axial pedicle screw placement by the position of the screw trajectory tip on the anteroposterior and lateral radiographs].

Objective: To propose a method to judge the safety of axial pedicle screw placement based on the position of the tip of the screw trajectory on the anteroposterior and lateral X-ray radiographs. Methods: The cervical CT data of 40 patients admitted to the Second Affiliated Hospital of Wenzhou Medical University from December 2020 to December 2021 were selected, including 24 males and 16 females, with a mean age of (47.6±13.2) years. Based on the three-dimensional model reconstruction of Mimics software and its function of X-ray, the transmission of the axial pedicle screw and its anteroposterior and lateral films was simulated. The position of the tip of the simulated screw trajectory was divided into 5 regions (regions Ⅰ-Ⅴ) from the inside to the outside on the anteroposterior virtual radiographs, and the upper and lower regions (regions a, b) on the lateral virtual radiographs. By adjusting the direction of the screw, the tip of the screw was located in the corresponding 10 regions (80 screws in each area) on the virtual projections of the anteroposterior and lateral virtual radiographs respectively, and its accuracy was analyzed by CT to determine whether each screw penetrated the medial wall of the pedicle or vertebral artery foramen. The anteroposterior and lateral X-rays and postoperative CT data of 34 patients who underwent axial pedicle screw placement (67 axial pedicle screws were placed in total) from January 2014 to December 2021 were collected, including 18 males and 16 females, with a mean age of (45.8±14.1) years. The position of the tip of the screw trajectory on the anteroposterior and lateral films was divided in the same way. The number of screws in the corresponding 10 positions was counted, and CT analysis was used to determine whether each screw penetrated the medial wall of the axial pedicle or the vertebral artery foreman. Results: The results of the imaging simulation screw placement study showed that the perforation rate of the vertebral artery foramen in region Ⅳ and Ⅴ was 75.0% (120/160) and 100% (160/160), respectively, while the perforation rate of the medial wall of the axial pedicle in the region Ⅰ was 85.6%(137/160). The failure rate in regions Ⅱ and Ⅲ was relatively lower, and the performance of simulated screws located in the region a was better than those in region b. The perforation rates of the medial wall in regions (a-Ⅱ) and (a-Ⅲ) was 7.5% (6/80) and 0 (0/80), respectively, and the perforation rates of the vertebral foramen was 0 (0/80) and 21.3% (17/80), respectively. The retrospective imaging study also showed a higher rate of placement failure in regions Ⅰ, Ⅳ and Ⅴ, and relatively lower in regions Ⅱ and Ⅲ. There were total of 15 screws in region a-Ⅱ and a-Ⅲ, and no destruction of the medial wall of the axial pedicle and the vertebral artery foreman occurred there. Conclusions: Regions a-Ⅱ and a-Ⅲ are the "safety areas" of the tip of the pedicle screw trajectory in the axial vertebra. By analyzing the tip of the pedicle screw trajectory on the anteroposterior and lateral radiographs, the operator can determine the reasonable trajectory of axial pedicle screw placement, prevent the injury of the cervical spinal cord and vertebral artery, and reduce the risk of operation.

Adherence and Exercise Capacity Improvements of Patients With Adult Congenital Heart Disease Participating in Cardiac Rehabilitation.

Background As the number of adults with congenital heart disease increases because of therapeutic advances, cardiac rehabilitation (CR) is increasingly being used in this population after cardiac procedures or for reduced exercise tolerance. We aim to describe the adherence and exercise capacity improvements of patients with adult congenital heart disease (ACHD) in CR. Methods and Results This retrospective study included patients with ACHD in CR at New York University Langone Rusk Rehabilitation from 2013 to 2020. We collected data on patient characteristics, number of sessions attended, and functional testing results. Pre-CR and post-CR metabolic equivalent task, exercise time, and maximal oxygen uptake were assessed. In total, 89 patients with ACHD (mean age, 39.0 years; 54.0% women) participated in CR. Referral indications were reduced exercise tolerance for 42.7% and post-cardiac procedure (transcatheter or surgical) for the remainder. Mean number of sessions attended was 24.2, and 42 participants (47.2%) completed all 36 CR sessions. Among participants who completed the program as well as pre-CR and post-CR functional testing, metabolic equivalent task increased by 1.3 (95% CI, 0.7-1.9; baseline mean, 8.1), exercise time increased by 66.4 seconds (95% CI, 21.4-111.4 seconds; baseline mean, 536.1 seconds), and maximal oxygen uptake increased by 2.5 mL/kg per minute (95% CI, 0.7-4.2 mL/kg per minute; baseline mean, 20.2 mL/kg per minute). Conclusions On average, patients with ACHD who completed CR experienced improvements in exercise capacity. Efforts to increase adherence would allow more patients with ACHD to benefit.

Prediction of Metal Ion Binding Sites of Transmembrane Proteins.

The metal ion binding of transmembrane proteins (TMPs) plays a fundamental role in biological processes, pharmaceutics, and medicine, but it is hard to extract enough TMP structures in experimental techniques to discover their binding mechanism comprehensively. To predict the metal ion binding sites for TMPs on a large scale, we present a simple and effective two-stage prediction method TMP-MIBS, to identify the corresponding binding residues using TMP sequences. At present, there is no specific research on the metal ion binding prediction of TMPs. Thereby, we compared our model with the published tools which do not distinguish TMPs from water-soluble proteins. The results in the independent verification dataset show that TMP-MIBS has superior performance. This paper explores the interaction mechanism between TMPs and metal ions, which is helpful to understand the structure and function of TMPs and is of great significance to further construct transport mechanisms and identify potential drug targets.

Inhibition of the BTK-IDO-mTOR axis promotes differentiation of monocyte-lineage dendritic cells and enhances anti-tumor T cell immunity.

Monocytic-lineage inflammatory Ly6c+CD103+ dendritic cells (DCs) promote antitumor immunity, but these DCs are infrequent in tumors, even upon chemotherapy. Here, we examined how targeting pathways that inhibit the differentiation of inflammatory myeloid cells affect antitumor immunity. Pharmacologic inhibition of Bruton's tyrosine kinase (BTK) and the tryptophan-degrading enzyme indoleamine 2,3-dioxygenase (IDO) or deletion of Btk or Ido1 allowed robust differentiation of inflammatory Ly6c+CD103+ DCs during chemotherapy, promoting antitumor T cell responses and inhibiting tumor growth. Immature Ly6c+c-kit+ precursor cells had epigenetic profiles similar to conventional DC precursors; deletion of Btk or Ido1 promoted differentiation of these cells. Mechanistically, a BTK-IDO axis inhibited a tryptophan-sensitive differentiation pathway driven by GATOR2 and mTORC1, and disruption of the GATOR2 in monocyte-lineage precursors prevented differentiation into inflammatory DCs in vivo. IDO-expressing DCs and monocytic cells were present across a range of human tumors. Thus, a BTK-IDO axis represses differentiation of inflammatory DCs during chemotherapy, with implications for targeted therapies.

Chondrosarcoma in a paediatric population: a study of 247 cases.

PURPOSE: The aims of present study are to clarify the follow questions: 1) what constitutes paediatric chondrosarcoma?; 2) what are the effects of the demographic and tumour characteristics on survival in patients with paediatric chondrosarcoma?; 3) which prognostic factors of paediatric chondrosarcoma differ from those of the adult population, which have been reported previously? METHODS: Paediatric patients who were diagnosed with chondrosarcoma were searched for using the case listing session protocol of the National Cancer Institute's Surveillance, Epidemiology, and End Results 18 databases (1973 to 2014). The extracted demographic information includes: age, race, gender, year of diagnosis, tumour sites, tumour histological subtype, grade, stage and treatment. RESULTS: A total of 247 paediatric chondrosarcoma patients were extracted and included in our present study. We find that the paediatric patients have significantly better survival rates than the adult patients. The year of diagnosis, tumour sites, tumour histological subtype, grade, stage and surgery received are independent prognostic factors for the survival rate of paediatric chondrosarcoma patients, but race, gender and age are not. CONCLUSION: The paediatric chondrosarcoma patients have better survival rates than the adults. Paediatric patients with a diagnosis at an early age, tumour site at the vertebral column and pelvis/sacrococcyx, myxoid variants, high grade, distant stage and who did not have surgery have a poorer prognosis than patients with a diagnosis at a later age, tumour site at limbs, head and base, chondrosarcoma not otherwise specified, lower grade, localized stage and who received surgery. LEVEL OF EVIDENCE: II -Prognostic Study.

An informatics guided classification of miscible and immiscible binary alloy systems.

The classification of miscible and immiscible systems of binary alloys plays a critical role in the design of multicomponent alloys. By mining data from hundreds of experimental phase diagrams, and thousands of thermodynamic data sets from experiments and high-throughput first-principles (HTFP) calculations, we have obtained a comprehensive classification of alloying behavior for 813 binary alloy systems consisting of transition and lanthanide metals. Among several physics-based descriptors, the slightly modified Pettifor chemical scale provides a unique two-dimensional map that divides the miscible and immiscible systems into distinctly clustered regions. Based on an artificial neural network algorithm and elemental similarity, the miscibility of the unknown systems is further predicted and a complete miscibility map is thus obtained. Impressively, the classification by the miscibility map yields a robust validation on the capability of the well-known Miedema's theory (95% agreement) and shows good agreement with the HTFP method (90% agreement). Our results demonstrate that a state-of-the-art physics-guided data mining can provide an efficient pathway for knowledge discovery in the next generation of materials design.

High-sensitivity cardiac troponin T is a predictor of recurrent acute coronary syndrome in patients with acute myocardial infarction.

High-sensitivity cardiac troponin T is a useful tool for diagnosing myocardial ischemia. However, its role in the prognosis of patients with acute myocardial infarction has not been studied. Here, the prognostic value of high-sensitivity cardiac troponin T for patients with acute myocardial infarction was investigated. The concentrations of high-sensitivity cardiac troponin T, other clinical chemistry makers, and living habits were investigated at the time of admission in patients with acute coronary syndrome, whereas the high-sensitivity cardiac troponin T concentrations at 6 h after admission and during recovery were analyzed in other patient groups. The concentration of high-sensitivity cardiac troponin T was significantly higher in patients with acute myocardial infarction than in those with other cardiac diseases and in controls (P < 0.01). Based on the standard diagnostic criterion, 134 patients were diagnosed with acute myocardial infarction. Monitoring the change in concentration of high-sensitivity cardiac troponin T in patients with acute coronary syndrome can reduce the risk of recurrence and death.

An antiproliferative gene FLNA regulates migration and invasion of gastric carcinoma cell in vitro and its clinical significance.

This study aimed to analyze the expression and clinical significance of filamin A (FLNA) in gastric carcinoma and the biological effect in its cell line by FLNA overexpression. Immunohistochemistry and western blot were used to analyze FLNA protein expression in 47 cases of gastric cancer and 47 cases of normal tissues to study the relationship between FLNA expression and clinical factors. FLNA lentiviral vector and empty vector were respectively transfected into gastric cancer SGC-7901 cell line. Reverse transcription-polymerase chain reaction (RT-PCR) and western blot were used to detect the mRNA level and protein of FLNA. 3-[4,5-Dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide (MTT) assay and migration and invasion assays were also conducted to determine the influence of the upregulated expression of FLNA that might be found on SGC-7901 cell biological effect. Immunohistochemistry: The level of FLNA protein expression was found to be significantly lower in gastric cancer tissue than normal tissues (P < 0.05). Western blot: The relative amount of FLNA protein in gastric cancer tissue was found to be significantly lower than in normal tissues (P < 0.05). The level of FLNA protein expression was not correlated with gender, age, and tumor invasion (P > 0.05), but it was correlated with lymph node metastasis, clinic stage, and histological grade (P < 0.05). Loss of FLNA expression correlated significantly with poor overall survival time by Kaplan-Meier analysis (P < 0.05). The result of biological function showed that SGC-7901 cell transfected FLNA had a lower survival fraction, significant decrease in migration and invasion, and lower matrix metallopeptidase 9 (MMP-9) protein expression compared with SGC-7901 cell untransfected FLNA (P < 0.05). FLNA expression decreased in gastric cancer and correlated significantly with lymph node metastasis, clinic stage, histological grade, and poor overall survival, suggesting that FLNA may play important roles as a negative regulator to gastric cancer SGC-7901 cell by promoting degradation of MMP-9.

BTG1 expression correlates with the pathogenesis and progression of breast carcinomas.

This study aimed to analyze the expression, clinical significance of B cell translocation gene 1 (BTG1) in breast carcinoma and the biological effect in its cell line by BTG1 overexpression. Immunohistochemistry and western blot were used to analyze BTG1 protein expression in 72 cases of breast cancer and 36 cases of normal tissues to study the relationship between BTG1 expression and clinical factors. Recombinant lentiviral vector was constructed to over-express EMP-1 and then infect breast cancer MCF-7 cell line. Quantitative real-time RT-PCR (qRT-PCR) and western blot were used to detect the mRNA level and protein of BTG1. MTT assay, cell apoptosis, cell cycles, migration and invasion assays were also conducted as to the influence of the upregulated expression of BTG1 that might be found on MCF-7 cells biological effect. The level of BTG1 protein expression was found to be significantly lower in breast cancer tissue than normal tissues (P < 0.05). Decreased expression of BTG1 was significantly correlated with tumor invasion, lymph node metastasis, clinic stage and histological grade of patients with breast cancer (P < 0.05). Meanwhile, loss of BTG1 expression correlated significantly with poor overall survival time by Kaplan-Meier analysis (P < 0.05). The result of biological function shown that MCF-7 cell transfected BTG1 had a lower survival fraction, higher percentage of the G0/G1 phases, higher cell apoptosis, significant decrease in migration and invasion, and lower CyclinD1, Bcl-2, and MMP-9 protein expression compared with MCF-7 cell untransfected BTG1 (P < 0.05). BTG1 expression decreased in breast cancer and correlated significantly lymph node metastasis, clinic stage, histological grade, poor overall survival, proliferation, and metastasis in breast cancer cell by regulating CyclinD1, Bcl-2, and MMP-9 protein expression, suggesting that BTG1 may play important roles as a negative regulator to breast cancer cell.

Transient ischemia induces massive nuclear accumulation of SUMO2/3-conjugated proteins in spinal cord neurons.

OBJECTIVES: The objective of this study is to determine whether transient spinal cord ischemia activates small ubiquitin-like modifier (SUMO1-3) conjugation, a post-translational protein modification that protects neurons from ischemia-like conditions. METHODS: Mice were subjected to 8-12 min of spinal cord ischemia and 3-24 h of recovery using a newly developed experimental model. To characterize the model, activation of stress response pathways induced after spinal cord ischemia, previously observed in other experimental models, was verified by western blot analysis. Levels and subcellular localization of SUMO-conjugated proteins in spinal cords were evaluated by western blot analysis and immunohistochemistry, respectively. RESULTS: Following transient spinal cord ischemia, stress responses were activated as indicated by increased phosphorylation of eukaryotic initiation factor 2 (eIF2α), extracellular signal-regulated kinases (ERK1/2) and Akt. SUMO1 conjugation was not altered, but a selective rise in levels of SUMO2/3-conjugated proteins occurred, peaking at 6 h reperfusion. The marked activation of SUMO2/3 conjugation was a neuronal response to ischemia, as indicated by co-localization with the neuronal marker NeuN, and was associated with nuclear accumulation of SUMO2/3-conjugated proteins. CONCLUSION: Our study suggests that spinal cord neurons respond to ischemic stress by activation of SUMO2/3 conjugation. Many of the identified SUMO target proteins are transcription factors and other nuclear proteins involved in gene expression and genome stability. It is therefore concluded that the post-ischemic activation of SUMO2/3 conjugation may define the fate of neurons exposed to a transient interruption of blood supply, and that this pathway could be a therapeutic target to increase the resistance of spinal cord neurons to transient ischemia.

The n-terminal 5-MER peptide analogue P165 of amyloid precursor protein exerts protective effects on SH-SY5Y cells and rat hippocampus neuronal synapses.

The disturbance of the insulin-signaling pathway plays an important role in Alzheimer's disease. Resistance to insulin signaling renders neurons energy-deficient and vulnerable to oxidization or other metabolic insults and impairs synaptic plasticity. In search of neuroprotective drugs, we synthesized a peptide analogue, P165, an active domain of the soluble amyloid precursor protein, which is resistant to degradation and is suitable for oral administration in a clinical setting. Initially, we confirmed that P165 can protect cells from streptozotocin-caused damage and stimulate cell outgrowth using cultured SH-SY5Y cell lines treated with streptozotocin. P165 significantly reduced lactate dehydrogenase leakage from damaged cells, thereby rescuing cell energy production. Insulin signaling such as insulin receptor substrate-1 (IRS-1) and phosphoinositide 3-kinase (PI3K) proteins were upregulated to stimulate cell survival and growth. We proceeded to investigate the effect of P165 on streptozotocin-treated Alzheimer's disease (AD) rats. The data showed that P165 protected synaptic loss and dysfunction by increasing synaptophysin and PSD-95 (post synaptic density-95), while simultaneously decreasing α-synuclein expression. Moreover, animal behavior testing clearly showed that P165 increased rats' learning and memory activity. Overall, these results constitute evidence that peptide analogue 165 may protect synapse and improve learning and memory ability in AD.

Development of time-resolved immunofluorometric assays for vascular endothelial growth factor and application on plasma of patients with gastric tumours.

A highly sensitive and accurate time-resolved immunofluorometric assay (TR-IFMA) has been developed, for the first time, to measure plasma vascular endothelial growth factor (VEGF) in patients with gastric tumours. A monoclonal anti-hVEGF antibody and a biotinylated anti-hVEGF antibody were used to develop a non-competitive 'sandwich'-type assay. Fluorescence can be measured by a time-resolved fluorometer after binding of europium (Eu)(3+)-labelled streptavidin to the biotinylated immunoglobulin. Plasma VEGF concentrations were measured by TR-IFMA in 92 healthy controls, in 36 benign stomach disease patients and in 92 gastric cancer patients before surgery. The association between plasma VEGF levels and clinicopathological features was evaluated. A standard curve for VEGF TR-IFMA has been developed with good sensitivity (0.37 pg/ml). Accuracy studies, specificity, parallelism and precision data were determined and all were found to be satisfactory. The validity of the VEGF assay was confirmed by the good correlation between the results obtained by TR-IFMA and commercial enzyme-linked immunosorbent assay (ELISA) (ELISA result = 1.862 + 0.953 (TR-IFMA result), r = 0.944]. The plasma levels of VEGF are higher in gastric cancer patients than in healthy controls. VEGF levels were associated significantly with the presence of distant metastases, as well as invasion depth of the tumour and tumour stage, but not with tumour location, tumour histology, differentiation or the presence of lymph node metastases. At the cut-off of 217.79 pg/ml, the diagnostic sensitivity, specificity and accuracy of the TR-IFMA were 40.2%, 93.7% and 69.9%, respectively. A highly sensitive and reliable TR-IFMA for VEGF has been developed. The determination of plasma VEGF levels may be clinically useful.

C-terminal modification is required for GABARAP-mediated GABA(A) receptor trafficking.

We investigated the ubiquitin-like modification of GABA(A) receptor-associated protein (GABARAP) and its function. A fusion protein of GABARAP with v5 in the N terminus and myc in the C terminus was expressed in rat cultured hippocampal neurons and PC12 cells. Western blotting with antibodies to v5 and myc revealed that the C terminus of GABARAP was cleaved off. Cleavage was blocked by mutating the C-terminal Gly116 to Ala, suggesting that G116 is required for the processing. Unlike ubiquitin, GABARAP was not incorporated covalently into higher-molecular-weight protein complexes. Nor was GABARAP degraded by ubiquitinylation through the proteasome, although GABARAP formed noncovalent dimers. Immunofluorescent confocal microscopy demonstrated that recombinantly expressed GABARAP was diffusely localized in PC12 cells. However, prevention of C-terminal processing in the mutant GABARAP(G116A) resulted in redistribution to the Golgi. In neurons, punctate cytoplasmic staining of GABARAP was seen in soma and processes, whereas GABARAP(G116A) was limited to soma. Compared with wild-type GABARAP, the colocalization and interaction of GABARAP(G116A) with GABA(A) receptors were significantly reduced, resulting in a reduction in expression of receptors in the plasma membrane. When alpha1beta2gamma2S-containing GABA(A) receptors were expressed in oocytes, the increased surface expression of GABA(A) receptors, as shown by increased GABA currents and surface-accessible GABA(A) receptor subunit polypeptides resulting from GABARAP coexpression, was prevented by mutation G116A. In addition, the distribution of NSF (N-ethylmaleimide-sensitive factor) was affected in GABARAP(G116A)-expressing neurons. These results suggest that glycine 116 is required for C-terminal processing of GABARAP and that processing is essential for the localization of GABARAP and its functions as a trafficking protein.