Unveiling hierarchy and spatial distribution of O6-methylguanine-DNA methyltransferase promoter methylation in World Health Organization grade 2-3 gliomas.

This study investigated the role of O6-methylguanine-DNA methyltransferase promoter (MGMTp) methylation hierarchy and heterogeneity in grade 2-3 gliomas, focusing on variations in chemotherapy benefits and resection dependency. A cohort of 668 newly diagnosed grade 2-3 gliomas, with comprehensive clinical, radiological, and molecular data, formed the basis of this analysis. The extent of resection was categorized into gross total resection (GTR ≥100%), subtotal resection (STR >90%), and partial resection (PR ≤90%). MGMTp methylation levels were examined using quantitative pyrosequencing. Our findings highlighted the critical role of GTR in improving the prognosis for astrocytomas (IDH1/2-mutant and 1p/19q non-codeleted), contrasting with its lesser significance for oligodendrogliomas (IDH1/2 mutation and 1p/19q codeletion). Oligodendrogliomas demonstrated the highest average MGMTp methylation levels (median: 28%), with a predominant percentage of methylated cases (average methylation levels >20%). Astrocytomas were more common in the low-methylated group (10%-20%), while IDH wild-type gliomas were mostly unmethylated (<10%). Spatial distribution analysis revealed a decrement in frontal lobe involvement from methylated, low-methylated to unmethylated cases (72.8%, 59.3%, and 47.8%, respectively). In contrast, low-methylated and unmethylated cases were more likely to invade the temporal-insular region (19.7%, 34.3%, and 40.4%, respectively). Astrocytomas with intermediate MGMTp methylation were notably associated with temporal-insular involvement, potentially indicating a moderate response to temozolomide and underscoring the importance of aggressive resection strategies. In conclusion, our study elucidates the complex interplay of MGMTp methylation hierarchy and heterogeneity among grade 2-3 gliomas, providing insights into why astrocytomas and IDH wild-type lower-grade glioma might derive less benefit from chemotherapy.

TLR agonists promote formation of Tertiary Lymphoid Structure and improve anti-glioma immunity.

BACKGROUND: Glioma, characterized by limited lymphocytic infiltration, constitutes an "immune-desert" tumor displaying insensitivity to various immunotherapies. This study aims to explore therapeutic strategies for inducing tertiary lymphoid structure (TLS) formation within the glioma microenvironment (GME) to transition it from an immune-resistant to an activated state. METHODS: TLS formation in GME was successfully induced by intracranial administration of Toll-like receptor (TLR) agonists (OK-432, TLR2/4/9 agonist) and glioma antigens (i.c. αTLR-mix). We employed staining analysis, antibody neutralization, single-cell RNA sequencing (scRNA-Seq), and BCR/TCR sequencing to investigate the underlying mechanisms of TLS formation and its role in anti-glioma immunity. Additionally, a preliminary translational clinical study was conducted. RESULTS: TLS formation correlated with increased lymphocyte infiltration in GME and led to improved prognosis in glioma-bearing mice. In the study of TLS induction mechanisms, certain macrophages/microglia and Th17 displayed markers of "LTo" and "LTi" cells, respectively, interaction through LTα/ß-LTßR promoted TLS induction. Post-TLS formation, CD4+ and CD8+ T cells but not CD19+ B cells contributed to anti-glioma immunity. Comparative analysis of B/T cells between brain and lymph node showed that brain B/T cells unveiled switch from naïve to mature, some B cells highlighted an enrichment of CSR-associated genes, V gene usage and clonotype bias were observed. In related clinical studies, i.c. αTLR-mix treatment exhibited tolerability, and chemokines/cytokines assay provided preliminary evidence supporting TLS formation in GME. CONCLUSION: TLS induction in GME enhanced anti-glioma immunity, improved the immune microenvironment, and controlled glioma growth, suggesting potential therapeutic avenues for treating glioma in the future.

[Comparative study of the effects of intramedullary nail fixation and minimally invasive percutaneous plate internal fixation technique on platelet activation and serum transforming growth factor-ß1(TGF-ß) 1 and bone morphogenetic protein-2 (BMP-2) in patients with tibial and fibular fracture].

OBJECTIVE: To investigate the effect of intramedullary nail fixation (IMN) and minimally invasive percutaneous plate internal fixation (MIPPO) techniques on tibiofibular fractures and their effect on platelet activation and serum transforming growth factor-ß1 (TGF-ß1) and bone morphogenetic protein-2 (BMP-2). METHODS: Total of 105 patients with tibiofibular fractures from February 2019 to February 2020 were selected and divided into 53 cases in the MIPPO group and 52 cases in the IMN group. There were 29 males and 24 females with an average age of (41.74±6.05) years old in MIPPO group;in IMN group, 31 males and 21 females with an average age of (40.59±5.26) years old. The perioperative surgical indexes, postoperative complications, ankle function recovery at 12 months postoperatively, platelet activation indexes at 3 and 7 days preoperatively and postoperatively, and serum TGF-ß1 and BMP-2 levels at 4 and 8 weeks preoperatively and postoperatively were compared between the two groups. RESULTS: The operating time and fracture healing time in the MIPPO group were shorter than those in the IMN group(P<0.05); Compared with the preoperative period, the levels of GMP-140, PAC-1, CD63, and CD61 increased in both groups at 3 and 7 days after surgery, but were lower in the MIPPO group than in the IMN group(P<0.05);the levels of serum TGF-ß1 and BMP-2 increased in both groups at 4 and 8 weeks after surgery compared with the preoperative period, and the postoperative complication rate in the MIPPO group was lower than that in the IMN group(P<0.05);the difference was not statistically significant in the excellent rate of ankle function recovery at 12 months follow-up after surgery between two groups(P>0.05). CONCLUSION: Both intramedullary nail fixation and MIPO technique for treatment of tibia and fibula fractures can improve ankle joint function, but the latter has the advantages of short operation time, fast fracture healing, fewer complications, and light platelet activation. Serum TGF-ß1, BMP-2 level improves quickly.

Research Status of Dendrimer Micelles in Tumor Therapy for Drug Delivery.

Dendrimers are a family of polymers with highly branched structure, well-defined composition, and extensive functional groups, which have attracted great attention in biomedical applications. Micelles formed by dendrimers are ideal nanocarriers for delivering anticancer agents due to the explicit study of their characteristics of particle size, charge, and biological properties such as toxicity, blood circulation time, biodistribution, and cellular internalization. Here, the classification, preparation, and structure of dendrimer micelles are reviewed, and the specific functional groups modified on the surface of dendrimers for tumor active targeting, stimuli-responsive drug release, reduced toxicity, and prolonged blood circulation time are discussed. In addition, their applications are summarized as various platforms for biomedical applications related to cancer therapy including drug delivery, gene transfection, nano-contrast for imaging, and combined therapy. Other applications such as tissue engineering and biosensor are also involved. Finally, the possible challenges and perspectives of dendrimer micelles for their further applications are discussed.

Characterization and clinical implications of different malignant transformation patterns in diffuse low-grade gliomas.

Malignant transformation (MT) of low-grade gliomas (LGGs) to a higher-grade variant seems inevitable, yet it remains unclear which LGG patients will progress to grade 3 or even directly to grade 4 after receiving a long course of treatment. To elucidate this, we conducted a retrospective cohort study based on 229 adults with recurrent LGG. Our study aimed to disclose the characteristics of different MT patterns and to build predictive models for patients with LGG. Patients were allocated into group 2-2 (n = 81, 35.4%), group 2-3 (n = 91, 39.7%), and group 2-4 (n = 57, 24.9%), based on their MT patterns. Patients who underwent MT showed lower Karnofsky performance scale (KPS) scores, larger tumor sizes, smaller extents of resection (EOR), higher Ki-67 indices, lower rates of 1p/19q codeletion, but higher rates of subventricular involvement, radiotherapy, chemotherapy, astrocytoma, and post-progression enhancement (PPE) compared with those in group 2-2 (p < 0.01). On multivariate logistic regression, 1p/19q codeletion, Ki-67 index, radiotherapy, EOR, and KPS score were independently associated with MT (p < 0.05). Survival analyses demonstrated that patients in group 2-2 had the longest survival, followed by group 2-3 and then group 2-4 (p < 0.0001). Based on these independent parameters, we constructed a nomogram model that exhibited superior potential (sensitivity: 0.864, specificity: 0.814, and accuracy: 0.843) compared with PPE in early prediction of MT. Combining the factors of 1p/19q codeletion, Ki-67 index, radiotherapy, EOR, and KPS score that were presented at initial diagnosis could precisely forecast the subsequent MT patterns of patients with LGG.

Screening of a short chain antimicrobial peptide-FWKFK and its application in wound healing.

As a kind of basic polypeptide with antibacterial properties, antimicrobial peptides play an important role in resisting the invasion of foreign microorganisms. Antimicrobial peptides have a wide range of antimicrobial activities against bacteria, fungi, viruses and other microorganisms. They are active against traditional antibiotic-resistant strains and do not easily cause bacterial resistance. In this study, we synthesized an antibacterial peptide library by a Fmoc solid phase synthesis method, and screened the peptide chain FWKFK by modified cell membrane chromatography. The minimum inhibitory concentration of FWKFK against E. coli and S. aureus was 200 µg mL-1 and 250 µg mL-1, respectively, and FWKFK also had inhibitory effects on P. aeruginosa, B. subtilis and S. epidermidis. Its biocompatibility and therapeutic effect on mouse wounds were then tested. The results showed that the survival rate of normal cells after FWKFK treatment was more than 95%, the hemolysis rate of red blood cells was as low as 6%, and it had a significant effect on wound healing in mice.

Polysaccharide-based nanocarriers for efficient transvascular drug delivery.

Polysaccharide-based nanocarriers (PBNs) are the focus of extensive investigation because of their biocompatibility, low cost, wide availability, and chemical versatility, which allow a wide range of anticancer agents to be loaded within the nanocarriers. Similar to other nanocarriers, most PBNs are designed to extravasate out of tumor vessels, depending on the enhanced permeability and retention (EPR) effect. However, the EPR effect is compromised in some tumors due to the heterogeneity of tumor structures. Transvascular transport efficacy is decreased by complex blood vessels and condensed tumor stroma. The limited extravasation impedes efficient drug delivery into tumor parenchyma, and thus affects the subsequent tumor accumulation, which hinders the therapeutic effect of PBNs. Therefore, overcoming the biological barriers that restrict extravasation from tumor vessels is of great importance in PBN design. Many strategies have been developed to enhance the EPR effect that involve nanocarrier property regulation and tumor structure remodeling. Moreover, some researchers have proposed active transcytosis pathways that are complementary to the paracellular EPR effect to increase the transvascular extravasation efficiency of PBNs. In this review, we summarize the recent advances in the design of PBNs with enhanced transvascular transport to enable optimization of PBNs in the extravasation of the drug delivery process. We also discuss the obstacles and challenges that need to be addressed to clarify the transendothemial mechanism of PBNs and the potential interactions between extravasation and other drug delivery steps.

Tri-Ponderal Mass Index Reference Values for Screening Metabolic Syndrome in Children and Adolescents: Results From Two National-Representative Cross-Sectional Studies in China and America.

Introduction: To ascertain the possible cut point of tri-ponderal mass index (TMI) in discriminating metabolic syndrome (MetS) and related cardio-metabolic risk factors in Chinese and American children and adolescents. Methods: A total of 57,201 Chinese children aged 7-18 recruited in 2012 and and 10,441 American children aged 12-18 from National Health and Nutrition Examination Survey (NHANES 2001-2014) were included to fit TMI percentiles. Participants were randomly assigned to a derivation set (75%) and validation set (25%). The cut points of TMI with the lowest misclassification rate under the premise of the highest area under curves (AUC) were selected for each sex, which were additionally examined in the validation set. All of data analysis was conducted between September and December in 2019. Results: TMI showed good capacity on discriminating MetS, with AUC of 0.7658 (95% CI: 0.7544-0.7770) to 0.8445 (95% CI: 0.8349-0.8537) in Chinese and 0.8871 (95% CI: 0.8663-0.9056) to 0.9329 (95% CI: 0.9166-0.9469) in American children. The optimal cut points were 14.46 kg/m3 and 13.91 kg/m3 for Chinese boys and girls, and 17.08 kg/m3 and 18.89 kg/m3 for American boys and girls, respectively. The corresponding misclassification rates were 17.1% (95% CI: 16.4-17.8) and 11.2% (95% CI: 9.9-12.6), respectively. Performance of these cut points were also examined in the validation set (sensitivity 67.7%, specificity 82.4% in Chinese; sensitivity 84.4%, specificity 88.7% in American children). Conclusions: A sex- and ethnicity- specific single cut point of TMI could be used to distinguish MetS and elevated risk of cardio-metabolic factors in children and adolescents.

Mechanisms of peripheral neurotoxicity associated with four chemotherapy drugs using human induced pluripotent stem cell-derived peripheral neurons.

The awareness of the long-term toxicities of cancer survivors after chemotherapy treatment has been gradually strengthened as the population of cancer survivors grows. Generally, chemotherapy-induced peripheral neurotoxicity (CIPN) is studied by animal models which are not only expensive and time-consuming, but also species-specific differences. The generation of human induced pluripotent stem cells (hiPSCs) and differentiation of peripheral neurons have provided an in vitro model to elucidate the risk of CIPN. Here, we developed a drug-induced peripheral neurotoxicity model using hiPSC-derived peripheral neurons (hiPSC-PNs) to study the mechanisms of different chemotherapeutic agents on neuronal viability using LDH assay, a cell apoptosis assay determined by caspase 3/7 activation, neurite outgrowth, ion channel expression and neurotransmitter release following treatment of cisplatin, bortezomib, ixabepilone, or pomalidomide. Our data showed that the multiple endpoints of the hiPSC-PNs model had different sensitivity to various chemotherapeutic agents. Furthermore, the chemotherapeutics separated cell viability from the decrease in neurite lengthand changed levels of ion channels and neurotransmitters to a certain extent. Thus, we study the mechanisms of peripheral neurotoxicity induced by chemotherapeutic agents through changes in these indicators.

Effect of Molybdenum on Plant Physiology and Cadmium Uptake and Translocation in Rape (Brassica napus L.) under Different Levels of Cadmium Stress.

This study investigated the beneficial effect of molybdenum (Mo) application on rape plants (Brassica napus L.) grown in a soil polluted by cadmium (Cd). A pot experiment was conducted to determine how different concentrations of exogenous Mo (0, 50, 100, and 200 mg/kg) affect plant physiology, biomass, photosynthesis, cation uptake, and Cd translocation and enrichment in rape plants under Cd stress (0.5 and 6.0 mg/kg). Under single Cd treatment, plant physiological and biochemical parameters, biomass parameters, leaf chlorophyll fluorescence parameters, and macroelement uptake of rape plants decreased, while their malonaldehyde content, proline content, non-photochemical quenching coefficient, and Cd uptake significantly increased, compared to those of the control group (p-values < 0.05). High-Cd treatment resulted in much larger changes in these parameters than low-Cd treatment. Following Mo application, the accumulation of malondialdehyde and proline decreased in the leaves of Cd-stressed plants; reversely, the contents of soluble protein, soluble sugar, and chlorophyll, and the activities of superoxide dismutase and glutathione peroxidase, all increased compared to those of single Cd treatment (p-values < 0.05). Exogenous Mo application promoted shoot and root growth of Cd-stressed plants in terms of their length, fresh weight, and dry weight. The negative effect of Cd stress on leaf chlorophyll fluorescence was substantially mitigated by applying Mo. Exogenous Mo also improved the uptake of inorganic cations, especially potassium (K+), in Cd-stressed plants. After Mo application, Cd uptake and accumulation were inhibited and Cd tolerance was enhanced, but Cd translocation was less affected in Cd-stressed plants. The mitigation effect of Mo on Cd stress in rape was achieved through the immobilization of soil Cd to reduce plant uptake, and improvement of plant physiological properties to enhance Cd tolerance. In conclusion, exogenous Mo can effectively reduce Cd toxicity to rape and the optimal Mo concentration was 100 mg/kg under the experimental conditions.

Visualization of ultrafast melting initiated from radiation-driven defects in solids.

Materials exposed to extreme radiation environments such as fusion reactors or deep spaces accumulate substantial defect populations that alter their properties and subsequently the melting behavior. The quantitative characterization requires visualization with femtosecond temporal resolution on the atomic-scale length through measurements of the pair correlation function. Here, we demonstrate experimentally that electron diffraction at relativistic energies opens a new approach for studies of melting kinetics. Our measurements in radiation-damaged tungsten show that the tungsten target subjected to 10 displacements per atom of damage undergoes a melting transition below the melting temperature. Two-temperature molecular dynamics simulations reveal the crucial role of defect clusters, particularly nanovoids, in driving the ultrafast melting process observed on the time scale of less than 10 ps. These results provide new atomic-level insights into the ultrafast melting processes of materials in extreme environments.

Femtosecond gas phase electron diffraction with MeV electrons.

We present results on ultrafast gas electron diffraction (UGED) experiments with femtosecond resolution using the MeV electron gun at SLAC National Accelerator Laboratory. UGED is a promising method to investigate molecular dynamics in the gas phase because electron pulses can probe the structure with a high spatial resolution. Until recently, however, it was not possible for UGED to reach the relevant timescale for the motion of the nuclei during a molecular reaction. Using MeV electron pulses has allowed us to overcome the main challenges in reaching femtosecond resolution, namely delivering short electron pulses on a gas target, overcoming the effect of velocity mismatch between pump laser pulses and the probe electron pulses, and maintaining a low timing jitter. At electron kinetic energies above 3 MeV, the velocity mismatch between laser and electron pulses becomes negligible. The relativistic electrons are also less susceptible to temporal broadening due to the Coulomb force. One of the challenges of diffraction with relativistic electrons is that the small de Broglie wavelength results in very small diffraction angles. In this paper we describe the new setup and its characterization, including capturing static diffraction patterns of molecules in the gas phase, finding time-zero with sub-picosecond accuracy and first time-resolved diffraction experiments. The new device can achieve a temporal resolution of 100 fs root-mean-square, and sub-angstrom spatial resolution. The collimation of the beam is sufficient to measure the diffraction pattern, and the transverse coherence is on the order of 2 nm. Currently, the temporal resolution is limited both by the pulse duration of the electron pulse on target and by the timing jitter, while the spatial resolution is limited by the average electron beam current and the signal-to-noise ratio of the detection system. We also discuss plans for improving both the temporal resolution and the spatial resolution.

Combined oral administration of bovine collagen peptides with calcium citrate inhibits bone loss in ovariectomized rats.

PURPOSE: Collagen peptides (CPs) and calcium citrate are commonly used as bone health supplements for treating osteoporosis. However, it remains unknown whether the combination of oral bovine CPs with calcium citrate is more effective than administration of either agent alone. METHODS: Forty 12-week-old Sprague-Dawley rats were randomly divided into five groups (n = 8) for once-daily intragastric administration of different treatments for 3 months at 3 months after ovariectomy (OVX) as follows: sham + vehicle; OVX + vehicle; OVX + 750 mg/kg CP; OVX + CP-calcium citrate (75 mg/kg); OVX + calcium citrate (75 mg/kg). After euthanasia, the femurs were removed and analyzed by dual energy X-ray absorptiometry and micro-computed tomography, and serum samples were analyzed for bone metabolic markers. RESULTS: OVX rats supplemented with CPs or CP-calcium citrate showed osteoprotective effects, with reductions in the OVX-induced decreases in their femoral bone mineral density. Moreover, CP-calcium citrate prevented trabecular bone loss, improved the microarchitecture of the distal femur, and significantly inhibited bone loss with increased bone volume, connectivity density, and trabecular number compared with OVX control rats. CP or CP-calcium citrate administration significantly increased serum procollagen type I N-terminal propeptide levels and reduced serum bone-specific alkaline phosphatase, osteocalcin, and C-telopeptide of type I collagen levels. CONCLUSIONS: Our data indicate that combined oral administration of bovine CPs with calcium citrate inhibits bone loss in OVX rats. The present findings suggest that combined oral administration of bovine CPs with calcium citrate is a promising alternative for reducing bone loss in osteopenic postmenopausal women.

Tunable few-cycle and multicycle coherent terahertz radiation from relativistic electrons.

We report the generation of tunable, narrow-band, few-cycle and multicycle coherent terahertz (THz) pulses from a temporally modulated relativistic electron beam. We demonstrate that the frequency of the THz radiation and the number of the oscillation cycles of the THz electric field can be tuned by changing the modulation period of the electron beam through a temporally shaped photocathode drive laser. The central frequency of the THz spectrum is tunable from ∼0.26 to 2.6 THz with a bandwidth of ∼0.16 THz.

Pharmacological effect of deoxypodophyllotoxin: a medicinal agent of plant origin, on mammalian neurons.

Deoxypodophyllotoxin (DOP) is a natural product that can be isolated from a variety of medicinal herb plants. It is well known for its antitumor, antiviral, and anti-inflammatory activities. However, there are few investigations that address neurotoxic effect of DOP in animal nervous system. In this study, whole-cell patch clamp and calcium imaging techniques were employed to investigate effects of DOP on electrophysiological properties and calcium regulation of rat dorsal root ganglion (DRG) neurons. DOP inhibited both TTX-S (tetrodotoxin-sensitive) and TTX-R (tetrodotoxin-resistant) sodium currents in voltage clamp recording and caused a decrease in the number of action potentials (APs) in current clamp experiment. Suppressive and unfavorable effects of DOP on the kinetics of sodium currents in terms of excitability of DRG neurons may greatly contribute to its antitumor and anti-inflammatory activities. Moreover, DOP evoked increase of intracellular Ca(2+) concentrations ([Ca(2+)](i)) in DRG neurons, and this effect may lead to neuronal cytotoxicity.

Effects of BmKNJX11, a bioactive polypeptide purified from Buthus martensi Karsch, on sodium channels in rat dorsal root ganglion neurons.

A long-chain polypeptide BmKNJX11 was purified from the venom of Asian scorpion Buthus martensi Karsch (BmK) by a combination of gel filtration, ion-exchange chromatography, and reverse-phase high-performance liquid chromatography. The molecular mass was found to be 7036.85 Da by electrospray ionization mass spectrometry. The first 15 N-terminal amino acid sequence of BmKNJX11 was determined to be GRDAY IADSE NCTYT by Edman degradation. With whole cell recording, BmKNJX11 inhibited tetrodotoxin-sensitive voltage-gated sodium channels (TTX-S VGSC) in freshly isolated rat dorsal root ganglion (DRG) neurons in a concentration- and voltage-dependent manner. At a concentration of 40 mug/ml BmKNJX11 lowered the activation threshold and produced negative shifting of TTX-S sodium current (I(Na)) activation curve. In addition, BmKNJX11 induced shifting of the steady-state inactivation curve to the left, delayed the recovery of TTX-S I(Na) from inactivation, and also reduced the fraction of available sodium channels. These results suggested that BmKNJX11 might exert effects on VGSC by binding to a specific site. Considering that TTX-S VGSC expressed in DRG neurons play a critical role in nociceptive transmission, the interaction of BmKNJX11 with TTX-S VGSC might lead to a change in excitability of nociceptive afferent fibers, which may be involved in the observed peripheral pain expression.