Binding uric acid: a pure chemical solution for the treatment of hyperuricemia.

Hyperuricemia, characterized by elevated uric acid levels and subsequent crystal deposition, contributing to conditions such as gout, cardiovascular events, and kidney injury, poses a significant health threat, particularly in developed countries. Current drug options for treatment are limited, with safety concerns, leading to suboptimal therapeutic outcomes in symptomatic hyperuricemia patients and a lack of pharmaceutical interventions for asymptomatic cases. Distinguishing from the previous drug design strategies, we directly target uric acid, the pathological molecule of hyperuricemia, resulting in a pyrimidine derivative capable of increasing the solubility and excretion of uric acid by forming a complex with it. Its prodrug showed an anti-hyperuricemia activity comparable to benzbromarone and a favorable safety profile in vivo. Our finding provides a strategy purely based on organic chemistry to address the largely unmet therapeutic needs on novel anti-hyperuricemia drugs.

Biomechanical analysis of adjacent segments after correction surgery for adult idiopathic scoliosis: a finite element analysis.

The biomechanical aspects of adjacent segment degeneration after Adult Idiopathic Scoliosis (AdIS) corrective surgery involving postoperative changes in motion and stress of adjacent segments have yet to be investigated. The objective of this study was to evaluate the biomechanical effects of corrective surgery on adjacent segments in adult idiopathic scoliosis by finite element analysis. Based on computed tomography data of the consecutive spine from T1-S1 of a 28-year-old male patient with adult idiopathic scoliosis, a three-dimensional finite element model was established to simulate the biomechanics. Two posterior long-segment fixation and fusion operations were designed: Strategy A, pedicle screws implanted in all segments of both sides, and Strategy B, alternate screws instrumentation on both sides. The range of motion (ROM), Maximum von Mises stress value of intervertebral disc (IVD), and Maximum von Mises stress of the facet joint (FJ) at the fixation adjacent segment were calculated and compared with data of the preoperative AdIS model. Corrective surgery decreased the IVD on the adjacent segments, increased the FJ on the adjacent segments, and decreased the ROM of the adjacent segments. A greater decrease of Maximum von Mises stress was observed on the distal adjacent segment compared with the proximal adjacent segment. The decrease of Maximum von Mises stress and increment of Maximum von Mises stress on adjacent FJ in strategy B was greater than that in strategy A. Under the six operation modes, the change of the Maximum von Mises stress on the adjacent IVD and FJ was significant. The decrease in ROM in the proximal adjacent segment was greater than that of the distal adjacent segment, and the decrease of ROM in strategy A was greater than that in strategy B. This study clarified the biomechanical characteristics of adjacent segments after AdIS corrective surgery, and further biomechanical analysis of two different posterior pedicle screw placement schemes by finite element method. Our study provides a theoretical basis for the pathogenesis, prevention, and treatment of adjacent segment degeneration after corrective surgery for AdIS.

A landscape of methodology and implementation of adaptive designs in cancer clinical trials.

BACKGROUND: The use of adaptive designs in cancer trials has considerably increased worldwide in recent years, along with the release of various guidelines for their application. This systematic review aims to comprehensively summarize the key methodological and executive features of adaptive designs in cancer clinical trials. METHODS: A comprehensive search from PubMed, EMBASE, and the Cochrane Central Register of Controlled Trials was conducted to screen eligible clinical trials that employed adaptive designs and were conducted in cancer patients. The methodological and executive characteristics of adaptive designs were the main measurements extracted. Descriptive analyses, primarily consisting of frequency and percentage, were employed to analyzed and reported the data. RESULTS: A total of 180 cancer clinical trials with adaptive designs were identified. The first three most common type of adaptive design was the group sequential design (n=114, 63.3 %), adaptive dose-finding design (n=22, 12.2 %), and adaptive platform design (n=16, 8.9 %). The results showed that 4.4 % (n=8) of trials conducted post hoc modifications, and around 29.4 % (n=53) did not provide the methods for controlling type I errors. Among phase II or above trials, 79.9 % (112/140) applied the surrogate endpoint as the primary outcome in these trials. Importantly, 27.2 % (49/180) of trials did not report clear information on the independent data monitoring committee (iDMC), and 13.3 % (n=24) without clear information on interim analyses. Interim analyses suggested 34.4 % (62/180) of trials being stopped for futility, 10.6 % (n=19) for efficacy, and 2.2 % (n=4) for safety concerns in the early stage. CONCLUSIONS: This study emphasizes adaptive designs in cancer trials face significant challenges in their design or strict implementation according to protocol, which might significantly compromise the validity and integrity of trials. It is thus important for researchers, sponsors, and policymakers to actively oversee and guide their application.

The optimal threshold of PD-L1 combined positive score to predict the benefit of PD-1 antibody plus chemotherapy for patients with HER2-negative gastric adenocarcinoma: a meta-analysis.

BACKGROUND: Immune checkpoint inhibitors (ICIs) combined with chemotherapy have become the first-line treatment of metastatic gastric and gastroesophageal adenocarcinomas (GEACs). This study aims to figure out the optimal combined positive score (CPS) cutoff value. METHODS: We searched for randomized phase III trials to investigate the efficacy of ICIs plus chemotherapy for metastatic GEACs compared with chemotherapy alone. Pooled analyses of hazard ratios (HRs) based on PD-L1 expression were performed. RESULTS: A total of six trials (KEYNOTE-062, KEYNOTE-590, KEYNOTE-859, ATTRACTION-04, CheckMate 649, and ORIENT-16) were included, comprising 5,242 patients. ICIs plus chemotherapy significantly improved OS (HR: 0.79, 95% CI 0.72-0.86 in global patients; HR: 0.75, 95% CI 0.57-0.98 in Asian patients) and PFS (HR: 0.74, 95% CI 0.68-0.82 in global patients; HR: 0.64, 95% CI 0.56-0.73 in Asian patients) compared with chemotherapy alone. The differences in OS (ratio of HR: 1.05, 95% CI 0.79-1.40; predictive value: - 5.1%) and PFS (ratio of HR: 1.16, 95% CI 0.98-1.36; predictive value: - 13.5%) were not statistically significant between the global and Asian patients. Subgroup analyses indicated that the optimal CPS threshold was at ≥ 5 for OS and ≥ 10 for PFS with the highest predictive values. CONCLUSIONS: The benefit derived from ICIs plus chemotherapy is similar between Asian and global GEAC patients. However, those with a PD-L1 CPS < 5 or CPS < 10 may not have significant benefits from ICIs therapy. Therefore, it is advisable to routinely assess PD-L1 expression in GEAC patients considered for ICIs treatment.

Two new quinoline alkaloid with neuroprotective activities from Xylaria longipes.

Two new quinoline alkaloids with an α, ß-unsaturated amide side chain, xylarinines A and B (1 and 2), were isolated from the ethyl acetate extracts of Xylaria longipes solid fermentation. The structures of these were primarily determined though NMR and HRESIMS data analysis. The absolute configuration of compound 1 was assigned using experimental and calculated ECD data. The neuroprotective effects of compounds 1 and 2 against glutamate-induced damage in PC12 cells were evaluated in vitro bioassay. The results demonstrated that both compounds significantly improved cell viability, inhibited apoptosis, decreased malondialdehyde (MDA) levels, increased superoxide dismutase (SOD) and glutathione (GSH) levels, and reduced intracellular reactive oxygen species (ROS) accumulation. These findings suggested that these mechanisms contribute to the neuroprotective effects of the compounds.

Enhancing Multi-species Liver Microsomal Stability Prediction through Artificial Intelligence.

Liver microsomal stability, a crucial aspect of metabolic stability, significantly impacts practical drug discovery. However, current models for predicting liver microsomal stability are based on limited molecular information from a single species. To address this limitation, we constructed the largest public database of compounds from three common species: human, rat, and mouse. Subsequently, we developed a series of classification models using both traditional descriptor-based and classic graph-based machine learning (ML) algorithms. Remarkably, the best-performing models for the three species achieved Matthews correlation coefficients (MCCs) of 0.616, 0.603, and 0.574, respectively, on the test set. Furthermore, through the construction of consensus models based on these individual models, we have demonstrated their superior predictive performance in comparison with the existing models of the same type. To explore the similarities and differences in the properties of liver microsomal stability among multispecies molecules, we conducted preliminary interpretative explorations using the Shapley additive explanations (SHAP) and atom heatmap approaches for the models and misclassified molecules. Additionally, we further investigated representative structural modifications and substructures that decrease the liver microsomal stability in different species using the matched molecule pair analysis (MMPA) method and substructure extraction techniques. The established prediction models, along with insightful interpretation information regarding liver microsomal stability, will significantly contribute to enhancing the efficiency of exploring practical drugs for development.

A Very Deep Graph Convolutional Network for 13C NMR Chemical Shift Calculations with Density Functional Theory Level Performance for Structure Assignment.

Nuclear magnetic resonance (NMR) chemical shift calculations are powerful tools for structure elucidation and have been extensively employed in both natural product and synthetic chemistry. However, density functional theory (DFT) NMR chemical shift calculations are usually time-consuming, while fast data-driven methods often lack reliability, making it challenging to apply them to computationally intensive tasks with a high requirement on quality. Herein, we have constructed a 54-layer-deep graph convolutional network for 13C NMR chemical shift calculations, which achieved high accuracy with low time-cost and performed competitively with DFT NMR chemical shift calculations on structure assignment benchmarks. Our model utilizes a semiempirical method, GFN2-xTB, and is compatible with a broad variety of organic systems, including those composed of hundreds of atoms or elements ranging from H to Rn. We used this model to resolve the controversial J/K ring junction problem of maitotoxin, which is the largest whole molecule assigned by NMR calculations to date. This model has been developed into user-friendly software, providing a useful tool for routine rapid structure validation and assignation as well as a new approach to elucidate the large structures that were previously unsuitable for NMR calculations.

A pair of new chromone enantiomers from Xylaria nigripes.

A pair of new chromone derivative enantiomers, (+)-xylarichromone A (1a) and (-)-xylarichromone A (1b), were isolated from the solid fermentation of Xylaria nigripes. The planar structure of 1 was determined by extensive NMR spectroscopic data, and its absolute configuration was assigned by comparison the ECD spectra with the known chromone derivatives. Compound 1 was the first chromone derivative reported from this medicinal fungus. The neuroprotective effects of 1 against oxygen and glucose deprivation (OGD) induced pheochromocytoma-12 cells (PC12) injury was investigated.

The ethnopharmacology, phytochemistry and pharmacology of the genus Hericium.

ETHNOPHARMACOLOGICAL RELEVANCE: Mushrooms in the genus Hericium are used as functional food and traditional medicines for a long history in East Asian countries such as China, India, Japan, and Korea. Some species of Hericium are called as monkey head mushroom (Houtougu) in China and Yamabushitake in Japan, which are traditionally considered as rare and precious health promoting food and medicinal materials for the treatment of dyspepsia, insomnia, chronic gastritis, and digestive tract tumors. THE AIM OF THE REVIEW: This review aims to summarize the ethnopharmacology and structural diversity of secondary metabolites from Hericium species, as well as the pharmacological activities of the crude extracts and pure compounds from Hericium species in recent years. MATERIALS AND METHODS: All the information was gathered by searching Scifinder, PubMed, Web of Science, ScienceDirect, Springer, Wiley, ACS, CNKI, Baidu Scholar, Google Scholar databases and other published materials (books and Ph.D. and M. Sc. Dissertations) using the keywords "Hericium", "Traditional uses", "Chemical composition", "Quality control" and "Pharmacological activity" (1971-May 2023). The species name was checked with https://www.mycobank.org/. RESULTS: The traditional uses of Hericium species were summarized, and 230 secondary metabolites from Hericium species were summarized and classified into six classes, mainly focusing on their chemical diversity, biosynthesis, biological activities. The modern pharmacological experiments in vivo or in vitro on their crude and fractionated extracts showed that the chemical components from Hericium species have a broad range of bioactivities, including neuroprotective, antimicrobial, anticancer, α-glucosidase inhibitory, antioxidant, and anti-inflammatory activities. CONCLUSIONS: The secondary metabolites discovered from Hericium species are highly structurally diverse, and they have the potential to be rich resources of bioactive fungal natural products. Moreover, the unveiled bioactivities of their crude extracts and pure compounds are closely related to critical human health concerns, and in-depth studies on the potential lead compounds, mechanism of pharmacological effects and pharmaceutical properties are clearly warranted.

p21 promotes gemcitabine tolerance in A549 cells by inhibiting DNA damage and altering the cell cycle.

Gemcitabine is one of the most widely used chemotherapy drugs for advanced malignant tumors, including non-small cell lung cancer. However, the clinical efficacy of gemcitabine is limited due to drug resistance. The aim of the present study was to investigate the role of p21 in gemcitabine-resistant A549 (A549/G+) lung cancer cells. IC50 values were determined using a Cell Counting Kit-8 (CCK-8) assay. mRNA and protein expression levels of genes were measured by reverse transcription-quantitative PCR and western blotting, respectively. The cell cycle distribution and apoptosis rate were analyzed by flow cytometry. DNA damage in cells was evaluated by single-cell gel electrophoresis. The results of western blot analysis and the CCK-8 assay demonstrated that the expression of p21 was higher in A549/G+ cells than in gemcitabine-sensitive cells. Knockdown of p21 expression in gemcitabine-resistant cells sensitized these cells to gemcitabine (with the IC50 decreasing from 84.2 to 26.7 µM). Cell cycle analysis revealed different changes in the cell cycle distribution in A549/G+ cells treated with the same concentration of gemcitabine, and decreased expression of p21 was shown to promote G1 arrest. The apoptosis assay and comet assay results revealed that decreased p21 expression resulted in accumulation of unrepaired DNA double-strand breaks (DSBs) and induction of apoptosis by gemcitabine. The present study demonstrated that knockout of p21 mRNA expression in A549/G+ cells promotes apoptosis and DNA DSB accumulation, accompanied by G1 arrest. These results indicated that p21 is involved in regulating the response of A549 cells to gemcitabine.

Development and application of hepatocellular carcinoma risk prediction model based on clinical characteristics and liver related indexes.

BACKGROUND: Hepatocellular carcinoma (HCC) is difficult to diagnose with poor therapeutic effect, high recurrence rate and has a low survival rate. The survival of patients with HCC is closely related to the stage of diagnosis. At present, no specific serological indicator or method to predict HCC, early diagnosis of HCC remains a challenge, especially in China, where the situation is more severe. AIM: To identify risk factors associated with HCC and establish a risk prediction model based on clinical characteristics and liver-related indicators. METHODS: The clinical data of patients in the Affiliated Hospital of North Sichuan Medical College from 2016 to 2020 were collected, using a retrospective study method. The results of needle biopsy or surgical pathology were used as the grouping criteria for the experimental group and the control group in this study. Based on the time of admission, the cases were divided into training cohort (n = 1739) and validation cohort (n = 467). Using HCC as a dependent variable, the research indicators were incorporated into logistic univariate and multivariate analysis. An HCC risk prediction model, which was called NSMC-HCC model, was then established in training cohort and verified in validation cohort. RESULTS: Logistic univariate analysis showed that, gender, age, alpha-fetoprotein, and protein induced by vitamin K absence or antagonist-II, gamma-glutamyl transferase, aspartate aminotransferase and hepatitis B surface antigen were risk factors for HCC, alanine aminotransferase, total bilirubin and total bile acid were protective factors for HCC. When the cut-off value of the NSMC-HCC model joint prediction was 0.22, the area under receiver operating characteristic curve (AUC) of NSMC-HCC model in HCC diagnosis was 0.960, with sensitivity 94.40% and specificity 95.35% in training cohort, and AUC was 0.966, with sensitivity 90.00% and specificity 94.20% in validation cohort. In early-stage HCC diagnosis, the AUC of NSMC-HCC model was 0.946, with sensitivity 85.93% and specificity 93.62% in training cohort, and AUC was 0.947, with sensitivity 89.10% and specificity 98.49% in validation cohort. CONCLUSION: The newly NSMC-HCC model was an effective risk prediction model in HCC and early-stage HCC diagnosis.

Multi-trajectories of health-related quality of life and their associated factors in patients with nasopharyngeal carcinoma: A longitudinal study.

BACKGROUND: The trajectories of health-related quality of life (HRQoL) of nasopharyngeal carcinoma (NPC) during and after the treatment along with their associated factors are seldom investigated in longitudinal studies. This study aims to investigate the longitudinal trajectories of HRQoL over time and their associated factors in patients with newly diagnosed NPC. METHODS: Between July 2018 and September 2019, a total of 500 patients were finally involved in this study. HRQoL was measured at four time points, from before treatment to the follow-up period after treatment. Group-based multi-trajectory modeling was applied to identify trajectories of five HRQoL functioning domains during the longitudinal period. Multinomial logistic regression models were applied to investigate potential independent factors associated with the multi-trajectory groups. RESULTS: We identified four distinct multi-trajectory groups, including the "initially lowest functioning" group (19.8%), the "initially lower functioning" group (20.8%), the "initially higher functioning" group (46.0%), and the "consistently highest functioning" group (13.4%). Patients who were older than 45 years or had T4 stage disease were more likely to be in the "initially lowest functioning" group, while those with EBV DNA ≥ 1500 copies/mL before the treatment were more likely to be in the "initially lowest functioning" or the "initially lower functioning" groups. CONCLUSIONS: We report the presence of heterogeneity in HRQoL trajectories among patients with NPC, and found that older age, advanced T stage, and higher EBV DNA level before treatment were significantly associated with poor HRQoL trajectories. Further studies are needed to examine the generalizability of these identified HRQoL trajectories and their associations with psychosocial and survival outcomes.

Liver-cell protective pyridones from the fungi Tolypocladium album dws120.

Five previously undescribed pyridone derivatives, tolypyridones I-M, were identified from the solid rice medium fermented by Tolypocladium album dws120, along with two known compounds tolypyridone A (or trichodin A) and pyridoxatin. Their planar structures and partial relative configurations have been determined by careful interpretation of their spectroscopic data. The full assignment of the relative and absolute configurations of tolypyridones I-M was achieved by gauge-independent atomic orbital 13C NMR calculation, quantitative nuclear Overhauser effects based interatomic distance calculation, and electronic circular dichroism calculation. In addition, we have fully determined the configuration of tolypyridone A by X-ray diffraction analysis. In bioassay, tolypyridones I was able to restore cell viability and inhibit the release of alanine aminotransferase and aspartate aminotransferase for ethanol-induced LO2 cells, suggesting its potential as a liver protective agent.

Two pairs of new isobenzofuranone enantiomers from a soil-derived fungus Penicillium canescens DWS225.

Two pairs of new isobenzofuranone derivative enantiomers, (±)-penicifurans E (1) and (±)-penicifurans F (2), together with four know compounds (3-6) were isolated from the solid fermentation of Penicillium canescens DWS225. The structures of these enantiomers were elucidated by extensive NMR spectroscopic data, and their absolute configurations were assigned by the experimental and calculated ECD data. The neuroprotective effects of all the isolates against oxygen-glucose deprivation/reperfusion injury in pheochromocytoma-12 cells (PC12) were investigated.

Neuroprotective methylsuccinic acid and enoic acid derivatives from the fungus Xylaria longipes.

Three undescribed methylsuccinic acid derivatives, xylaril acids A-C, and two undescribed enoic acid derivatives, xylaril acids D-E, were isolated from the fungus Xylaria longipes. The structures of the undescribed compounds were deduced by spectroscopic means, including HRESIMS and 1D/2D NMR spectroscopy, as well as ECD calculations. The absolute configuration of xylaril acids A was further determined by single-crystal X-ray diffraction experiments. All the isolated compounds displayed neuroprotective activities against oxygen-glucose deprivation/reperfusion injury in PC12 cells by enhancing cell viability and inhibiting cell apoptosis.

A theoretical study on pseudo Mott phase transition of vanadium dioxide.

The structural phase transition (SPT) and metal-insulator phase transition (MIT) always occur simultaneously upon heating from the low-temperature insulator M1 phase to the high-temperature metal R phase in vanadium dioxide, and it is still unclear which one of Mott correlation and Peierls distortion plays a decisive role in the thermally induced phase transition (PT) since 1959. Our density functional theory (DFT)-based calculations revealed that the intermediate phase in the PT, the so-called monoclinic metal phase, is a zero indirect band gap semimetal (P21/c space group) with a pseudo gap (199 meV). From the M1 phase to the monoclinic metal phase, the band gap decreases gradually to zero, and the bonding lengths between vanadium-vanadium atoms remain nearly constant. The SPT and MIT from the intermediate structure to the R phase occur simultaneously with a sudden change of bonding lengths between vanadium-vanadium atoms, in which electrons can jump down rather than jump up to the conduction band minimum (CBM) from the valence band maximum (VBM) under thermal fluctuation in order to lower the total energy of the system to push forward the occurrence of PT. The electron jumping does not require additional energy from Coulomb repulsion between electrons even though it is always present. This SPT is a typical Peierls PT or a pseudo Mott PT rather than an actual Mott PT in the each of the two stages. Our conclusions provide a new understanding of SPT and MIT in vanadium dioxide that has been debated for more than 80 years.

Reassignment of the structures of pestalopyrones A-D.

Pestalopyrones A-D are four unusual tricyclic pyrone derivatives with flexible chiral structures, isolated from the endophytic fungus Pestalotiopsis neglecta S3. The full elucidation of their structures was a challenging task, and remained unsolved in the original article. Herein, the relative configurations of pestalopyrones A and pestalopyrones B were unambiguously assigned by detailed analyses on spectroscopic data and GIAO 13C NMR calculation method with sorted training sets (STS). The planar structures of pestalopyrones C and pestalopyrones D were revised by reinterpretation of their reported spectroscopic data, and then their relative configurations were deduced by STS GIAO 13C NMR calculation and NOE analysis. The absolute configurations of all the mentioned compounds were determined by the comparison of their experimental and calculated ECD curves.

Simultaneous manipulation of transcriptional regulator CxrC and translational elongation factor eEF1A enhances the production of plant-biomass-degrading enzymes of Penicillium oxalicum.

Genetic engineering is an efficient approach to improve fungal bioproducts, but the specific targets are limited. In this study, it was found that the key transcription repressor CxrC of Penicillium oxalicum could physically interact with the translational elongation factor eEF1A that positively regulated the production of plant-biomass-degrading enzymes by the fungus under Avicel induction. Simultaneously deletion of the cxrC and overexpression of the eEF1A in the strain Δku70 resulted in 55.4%-314.6% higher production of cellulase, xylanase and raw-starch-degrading enzymes than that of the start strain Δku70. Transcript abundance of the genes encoding predominant cellulases, xylanases and raw-starch-degrading enzymes were significantly upregulated in the mutant ΔcxrC::eEF1A. The ΔcxrC::eEF1A enhanced saccharification efficiency of raw cassava flour by 9.3%-15.5% at early-middle stage of hydrolysis in comparison with Δku70. The obtained knowledges expanded the sources used as effective targets for increased production of plant-biomass-degrading enzymes by fungi.

Four new prenylflavonol glycosides from the leaves of Cyclocarya paliurus.

Four new prenylflavonol glycosides (1-4) along with two known analogues (5-6) were isolated from the leaves of Cyclocarya paliurus for the first time. The structures of these compounds were characterized by comprehensive analysis of 1 D, 2 D NMR, HRESIMS, UV data and enzymatic hydrolysis. In bioassays, compounds 1-4 were evaluated for inhibitory effects on xanthine oxidase (XOD) and effects on the inhibition of nitric oxide (NO) production in lipopolysaccharide (LPS) induced RAW264.7 cells. Moreover, compounds 1 and 2 showed outstanding XOD inhibitions with IC50 values of 18.16 ± 3.91 and 37.65 ± 5.67 µM, and exhibited inhibitions against LPS-induced NO production with IC50 values of 80.50 ± 3.09 and 82.28 ± 2.87 µM.

[Condensed tannins from roots of Indigofera stachyodes].

Eleven condensed tannins were isolated from the roots of Indigofera stachyodes by various column chromatography techniques including silica gel, octadecyl silica(ODS), Sephadex LH-20, and semi-preparative high performance liquid chromatography(HPLC). These compounds were identified on the basis of physicochemical properties, nuclear magnetic resonance(NMR) and mass spectrometry(MS) data as stachyotannin A(1), epicatechin-(2ß→O→7,4ß→8)-epiafzelechin-(4ß→8)-catechin(2), cinnamtannin D1(3), cinnamtannin B1(4), epicatechin-(2ß→O→7,4ß→8)-epiafzelechin-(4α→8)-epicatechin(5), gambiriin C(6), proanthocyanidin A1(7), proanthocyanidin A2(8), aesculitannin B(9), proanthocyanidin A4(10), and procyanidin B5(11). Compound 1 is a new compound. Compounds 2-11 were isolated from Indigofera for the first time. Furthermore, compounds 1, 2, and 4-11 showed inhibitory effects on thrombin-induced ATP release in platelets.