Rapid Endoscopic Diagnosis of Benign Ulcerative Colorectal Diseases With an Artificial Intelligence Contextual Framework.

BACKGROUND & AIMS: Benign ulcerative colorectal diseases (UCDs) such as ulcerative colitis, Crohn's disease, ischemic colitis, and intestinal tuberculosis share similar phenotypes with different etiologies and treatment strategies. To accurately diagnose closely related diseases like UCDs, we hypothesize that contextual learning is critical in enhancing the ability of the artificial intelligence models to differentiate the subtle differences in lesions amidst the vastly divergent spatial contexts. METHODS: White-light colonoscopy datasets of patients with confirmed UCDs and healthy controls were retrospectively collected. We developed a Multiclass Contextual Classification (MCC) model that can differentiate among the mentioned UCDs and healthy controls by incorporating the tissue object contexts surrounding the individual lesion region in a scene and spatial information from other endoscopic frames (video-level) into a unified framework. Internal and external datasets were used to validate the model's performance. RESULTS: Training datasets included 762 patients, and the internal and external testing cohorts included 257 patients and 293 patients, respectively. Our MCC model provided a rapid reference diagnosis on internal test sets with a high averaged area under the receiver operating characteristic curve (image-level: 0.950 and video-level: 0.973) and balanced accuracy (image-level: 76.1% and video-level: 80.8%), which was superior to junior endoscopists (accuracy: 71.8%, P < .0001) and similar to experts (accuracy: 79.7%, P = .732). The MCC model achieved an area under the receiver operating characteristic curve of 0.988 and balanced accuracy of 85.8% using external testing datasets. CONCLUSIONS: These results enable this model to fit in the routine endoscopic workflow, and the contextual framework to be adopted for diagnosing other closely related diseases.

Highly Reactive Graphene Dispersant and Its Effective Reinforcement for Phase Change Coatings.

High efficient dispersant that meanwhile possesses additional functions is highly desirable for the fabrication of graphene-based composite. In this paper, a new reactive dispersant, multi-silanols grafted naphthalenediamine (MSiND), is synthesized, which shows superiority compared with conventional dispersants. It can not only stabilize graphene in water at a high concentration of up to 16 mg mL-1 , but also simultaneously be applicable for ethanol medium, in which the graphene concentration can be as high as 12 mg mL-1 at the weight ratio of 1:1 (MSiND:graphene). The dispersion is compatible with multi-matrixes and affinity to various substrates. In addition, MSiND exhibits excellent reactivity due to the existence of high-density silanol groups. Tough graphene coatings are constructed on glass slides and non-woven fabric simply by direct painting and dip-coating. Moreover, with the assistance of MSiND, graphene-doped phase-change coatings on hydrophobic non-woven fabric (e.g., functional mask) are prepared via the spray method. The composite coatings show enhanced mechanical strength and excellent energy storage performance, exhibiting great potential in heat preservation and thermotherapy.

Interlayer Entropy Engineering Inducing the Symmetry-Broken Layered Oxide Cathodes to Activate Reversible High-Voltage Redox Reaction.

The as-reported doping entropy engineering of electrode materials that are usually realized by the sharing of multiple metal elements with the metal element from the lattice body, potentially has three shortages of stringent synthesis conditions, large active element loss, and serious lattice distortion. Herein, an interlayer entropy engineering of layered oxide cathodes is proposed, where the multiple metal ions are simultaneously intercalated into the same interlayer sites, thus avoiding the three shortages. Concretely, a novel interlayer medium-entropy V2O5 ((MnCoNiMgZn)0.26V2O5∙0.84H2O) is successfully constructed by a one-step hydrothermal method. The interlayer medium-entropy effect is revealed to be that five metal ions pre-intercalation induces the local symmetry-broken [VO6] octahedra in bilayer V2O5, thus activating the reversible high-voltage redox reaction, inhibiting the layer slip and following phase transformation by its pinning effect, and enhancing the charge transfer kinetics. As a result, the medium-entropy cathode realizes the trade-off between specific capacity and structural stability with a discharge capacity of 152 mAh g-1 at 0.1 A g-1 after 100 cycles, and a capacity retention rate of 98.7% at 0.5 A g-1 after 150 cycles for Li+ storage. This engineering provides a new guideline for the rational design of high-performance layered oxide cathodes.

Enabling Quasi-Zero-Strain Behavior of Layered Oxide Cathodes via Multiple-cations Induced Order-to-Disorder Transition.

The chemically pre-intercalated lattice engineering is widely applied to elevate the electronic conductivity, expand the interlayer spacing, and improve the structural stability of layered oxide cathodes. However, the mainstream unitary metal ion pre-intercalation generally produces the cation/vacancy ordered superstructure, which astricts the further improvement of lattice respiration and charge-carrier ion storage and diffusion. Herein, a multiple metal ions pre-intercalation lattice engineering is proposed to break the cation/vacancy ordered superstructure. Taking the bilayer V2O5 as an example, Ni, Co, and Zn ternary ions are simultaneously pre-intercalated into its interlayer space (NiCoZnVO). It is revealed that the Ni─Co neighboring characteristic caused by Ni(3d)-O(2p)-Co(3d) orbital coupling and the Co-Zn/Ni-Zn repulsion effect due to chemical bond incompatibility, endow the NiCoZnVO sample with the cation/vacancy disordered structure. This not only reduces the Li+ diffusion barrier, but also increases the diffusion dimension of Li+ (from one-dimension to two-dimension). Particularly, Ni, Co, and Zn ions co-pre-intercalation causes a prestress, which realizes a quasi-zero-strain structure at high-voltage window upon charging/discharging process. The functions of Ni ion stabilizing the lattice structure and Co or Zn ions activating more Li+ reversible storage reaction of V5+/V4+ are further revealed. The cation/vacancy disordered structure significantly enhances Li+ storage properties of NiCoZnVO cathode.

Double-negative T cells ameliorate psoriasis by selectively inhibiting IL-17A-producing γδlow T cells.

BACKGROUND: Psoriasis is a chronic immune-mediated skin condition. Although biologic treatments are effective in controlling psoriasis, some patients do not respond or lose response to these therapies. Thus, new strategies for psoriasis treatment are still urgently needed. Double-negative T cells (DNT) play a significant immunoregulatory role in autoimmune diseases. In this study, we aimed to evaluate the protective effect of DNT in psoriasis and explore the underlying mechanism. METHODS: We conducted a single adoptive transfer of DNT into an imiquimod (IMQ)-induced psoriasis mouse model through tail vein injection. The skin inflammation and IL-17A producing γδ T cells were evaluated. RESULTS: DNT administration significantly reduced the inflammatory response in mouse skin, characterized by decreased skin folds, scales, and red patches. After DNT treatment, the secretion of IL-17A by RORc+ γδlow T cells in the skin was selectively suppressed, resulting in an amelioration of skin inflammation. Transcriptomic data suggested heightened expression of NKG2D ligands in γδlow T cells within the mouse model of psoriasis induced by IMQ. When blocking the NKG2D ligand and NKG2D (expressed by DNT) interaction, the cytotoxic efficacy of DNT against RORc+IL17A+ γδlow T cells was attenuated. Using Ccr5-/- DNT for treatment yielded evidence that DNT migrates into inflamed skin tissue and fails to protect IMQ-induced skin lesions. CONCLUSIONS: DNT could migrate to inflamed skin tissue through CCR5, selectively inhibit IL-17-producing γδlow T cells and finally ameliorate mouse psoriasis. Our study provides feasibility for using immune cell therapy for the prevention and treatment of psoriasis in the clinic.

Imatinib facilitates gemcitabine sensitivity by targeting epigenetically activated PDGFC signaling in pancreatic cancer.

Pancreatic ductal adenocarcinoma (PDAC) is a malignant tumor with poor prognosis. Gemcitabine-based chemotherapy has become one of the main modalities of its management. However, gemcitabine resistance frequently occurs, leading to failure of PDAC therapy. Platelet-derived growth factors (PDGFs) and their receptors play important roles in cancer progression and chemoresistance. We aimed to investigate the biological function and therapeutic significance of platelet-derived growth factor C (PDGFC) in drug-resistant PDAC. Our study showed that PDGFC was abnormally highly expressed in gemcitabine-resistant PDAC. Silencing PDGFC expression can enhance the therapeutic effect of gemcitabine on PDAC. Mechanistically, the transcription of PDGFC is mediated by H3K27 acetylation, and PDGFC promotes gemcitabine resistance by activating the PDGFR-PI3K-AKT signaling pathway. The PDGFR inhibitor imatinib inhibits the PDGFR pathway. Imatinib and gemcitabine have a synergistic effect on the treatment of PDAC, and imatinib can significantly enhance the anti-tumor effect of gemcitabine in a drug-resistant PDAC patient-derived xenograft model. In conclusion, PDGFC is a potential predictor of gemcitabine-resistant PDAC. Imatinib inhibits PDGFR activation to promote gemcitabine sensitivity in PDAC. Combined modality regimen of imatinib and gemcitabine is likely to translate into clinical trial for the treatment of PDGFC-associated gemcitabine-resistant patients.

EPA and DHA Alleviated Chronic Dextran Sulfate Sodium Exposure-Induced Depressive-like Behaviors in Mice and Potential Mechanisms Involved.

Patients with ulcerative colitis (UC) have higher rates of depression. However, the mechanism of depression development remains unclear. The improvements of EPA and DHA on dextran sulfate sodium (DSS)-induced UC have been verified. Therefore, the present study mainly focused on the effects of EPA and DHA on UC-induced depression in C57BL/6 mice and the possible mechanisms involved. A forced swimming test and tail suspension experiment showed that EPA and DHA significantly improved DSS-induced depressive-like behavior. Further analysis demonstrated that EPA and DHA could significantly suppress the inflammation response of the gut and brain by regulating the NLRP3/ASC signal pathway. Moreover, intestine and brain barriers were maintained by enhancing ZO-1 and occludin expression. In addition, EPA and DHA also increased the serotonin (5-HT) concentration and synaptic proteins. Interestingly, EPA and DHA treatments increased the proportion of dominant bacteria, alpha diversity, and beta diversity. In conclusion, oral administration of EPA and DHA alleviated UC-induced depressive-like behavior in mice by modulating the inflammation, maintaining the mucosal and brain barriers, suppressing neuronal damage and reverting microbiota changes.

A highly efficient metal-free selective 1,4-addition of difluoroenoxysilanes to chromones.

A highly efficient metal-free selective 1,4-addition reaction of difluoroenoxysilanes to chromones was developed using the low-cost and readily available HOTf as the catalyst, which is a facile and straightforward method to access valuable C2-difluoroalkylated chroman-4-one derivatives. Interestingly, the products could be readily converted to the difluorinated bioisostere of the natural product (S)-2,6-dimethylchroman-4-one and a difluorinated benzo-seven-membered heterocycle via the Schmidt rearrangement reaction. In addition, the in vitro anti-proliferative activities of these synthesized derivatives against human colon carcinoma cells (HCT116) revealed that compound 3g exhibited potent inhibitory effect on HCT116 cancer cells with an IC50 value of 6.37 µM, representing a novel lead compound for further structural optimization and biological evaluation.

Valproate-related neutropenia and lithium-related leukocytosis in patients treated with clozapine: a retrospective cohort study.

BACKGROUND: Neutropenia is a noteworthy side effect of clozapine, which might warrant this drugs' discontinuance for safety. Studies have revealed that the risk of neutropenia increases with concurrent administration of valproate, but the evidence was limited. Conversely, lithium may have an ameliorating effect on clozapine-induced neutropenia. This study explored the effects of valproate and lithium on white blood cell counts in patients treated with clozapine. METHODS: We retrospectively investigated the electronic medical records from one tertiary psychiatric hospital in Taiwan and enrolled patients discharged between January 1, 2006, and December 31, 2017, with clozapine prescriptions. We scrutinized their demographic data, medications, and hematological results at discharge and during follow-up outpatient clinic visits over the subsequent 3 years. Patients were classified into four groups: clozapine only (CLO), clozapine and valproate (CLO + VAL), clozapine and lithium (CLO + Li), and clozapine, valproate, and lithium (CLO + VAL + Li). We also identified hematological events (neutropenia or leukocytosis) of these patients during outpatient follow-ups. RESULTS: Of the included 1084 patients, 55(5.1%) developed neutropenia. Concurrent valproate use (odds ratio [OR] = 3.49) and older age (p = .007) were identified as risk factors. Moreover, 453 (41.79%) patients developed leukocytosis. Younger age; male sex; and concurrent use of lithium (OR = 3.39, p < .001), clozapine daily dosage, and benzodiazepines were the risk factors for leukocytosis. CONCLUSION: Concurrent valproate use and older age are associated with the development of neutropenia in patients treated with clozapine. Concurrent lithium usage, younger age, male sex, and concurrent benzodiazepine use might be related to leukocytosis.

A New Method to Determine Antioxidant Activities of Biofilms Using a pH Indicator (Resazurin) Model System.

Biopolymeric films were prepared with gelatin, plasticizer, and three different types of antioxidants (ascorbic acid, phytic acid, and BHA) corresponding to different mechanisms in activity. The antioxidant activity of films was monitored for 14 storage days upon color changes using a pH indicator (resazurin). The instant antioxidant activity of films was measured by a DPPH free radical test. The system using resazurin was composed of an agar, an emulsifier, and soybean oil to simulate a highly oxidative oil-based food system (AES-R). Gelatin-based films (GBF) containing phytic acid showed higher tensile strength and energy to break than all other samples due to the increased intermolecular interactions between phytic acid and gelatin molecules. The oxygen barrier properties of GBF films containing ascorbic acid and phytic acid increased due to the increased polarity, while GBF films containing BHA showed increased oxygen permeability compared to the control. According to "a-value" (redness) of the AES-R system tested with films, films incorporating BHA showed the most retardation of lipid oxidation in the system. This retardation corresponds to 59.8% antioxidation activity at 14 days, compared with the control. Phytic acid-based films did not show antioxidant activity, whereas ascorbic acid-based GBFs accelerated the oxidation process due to its prooxidant activity. The comparison between the DPPH free radical test and the control showed that the ascorbic acid and BHA-based GBFs showed highly effective free radical scavenging behavior (71.7% and 41.7%, respectively). This novel method using a pH indicator system can potentially determine the antioxidation activity of biopolymer films and film-based samples in a food system.

Sulfonyl-PYBOX Ligands Enable Kinetic Resolution of α-Tertiary Azides by CuAAC.

We report the first highly selective kinetic resolution of racemic α-chiral azides via Cu-catalyzed azide-alkyne cycloaddition (CuAAC). Newly developed pyridine-bisoxazoline (PYBOX) ligands, bearing a C4 sulfonyl group, enable effective kinetic resolution of racemic azides derived from privileged scaffolds such as indanone, cyclopentenone, and oxindole, and their asymmetric CuAAC to afford α-tertiary 1,2,3-triazoles with high to excellent ee values. DFT calculations and control experiments reveal that the C4 sulfonyl group decreases the Lewis basicity of the ligand and increases the electrophilicity of the copper center for better recognition of azides, and functions as a shielding group to make the chiral pocket of the catalyst more effective.

Comprehensive Analysis of Glutamate Receptor-like Genes in Rice (Oryza sativa L.): Genome-Wide Identification, Characteristics, Evolution, Chromatin Accessibility, gcHap Diversity, Population Variation and Expression Analysis.

Glutamate receptors (GLR) are widely present in animals and plants, playing essential roles in regulating plant growth, development and stress response. At present, most studies of GLRs in plants are focused on Arabidopsis thaliana, while there have been few studies on rice. In this study, we identified 26 OsGLR genes in rice (Oryza sativa L.). Then, we analyzed the chromosomal location, physical and chemical properties, subcellular location, transmembrane (TM) helices, signal peptides, three-dimensional (3D) structure, cis-acting elements, evolution, chromatin accessibility, population variation, gene-coding sequence haplotype (gcHap) and gene expression under multiple abiotic stress and hormone treatments. The results showed that out of the 26 OsGLR genes, ten genes had the TM domain, signal peptides and similar 3D structures. Most OsGLRs exhibited high tissue specificity in expression under drought stress. In addition, several OsGLR genes were specifically responsive to certain hormones. The favorable gcHap of many OsGLR genes in modern varieties showed obvious differentiation between Xian/indica and Geng/japonica subspecies. This study, for the first time, comprehensively analyzes the OsGLR genes in rice, and provides an important reference for further research on their molecular function.

Time to Rehospitalization for Different Oral Risperidone Dosing Frequencies in Patients With Schizophrenia: A 17-Year Retrospective Cohort Study.

PURPOSE: This retrospective cohort study aimed at determining whether the daily administration pattern of risperidone influences time to rehospitalization in patients with schizophrenia. Previous studies have related more frequent dosing to poor medication adherence. This causes suboptimal disease control, which entails shorter times between hospital admissions. METHODS: We investigated admission records from 1 tertiary psychiatric hospital in Taiwan. Patients were included if they had a main diagnosis of schizophrenia or schizoaffective disorder and were receiving oral risperidone. The enrollment period was July 2001 to December 2016; we observed whether rehospitalization would occur in subsequent periods of 3-month, 6-month, and 1-year follow-ups. RESULTS: There were 1504 patients grouped by daily dosing frequency of oral risperidone. Most patients (95.9%) received 6 mg or less of risperidone per day. After adjustment for covariates, including daily total dosages of risperidone, it showed an independent association that more frequent dosing frequency of risperidone had higher hazard ratios (HRs) of rehospitalizations (in 1-year follow-up: 2 vs 1 dosing a day: HR, 1.566; 3 vs 1 dosing a day: HR, 3.010; 4 vs 1 dosing a day: HR, 4.305) and a significant trend of more possible rehospitalizations (Cochran-Armitage test for trend: P < 0.001) in 3-month, 6-month, and 1-year follow-up. CONCLUSIONS: Patients receiving more doses of risperidone per day are more likely to be readmitted within 1 year following last discharge, indicating poorer treatment outcomes for patients who receive more frequent doses.

Metabolic interventions: A new insight into the cancer immunotherapy.

Metabolic reprogramming confers cancer cells plasticity and viability under harsh conditions. Such active alterations lead to cell metabolic dependency, which can be exploited as an attractive target in development of effective antitumor therapies. Similar to cancer cells, activated T cells also execute global metabolic reprogramming for their proliferation and effector functions when recruited to the tumor microenvironment (TME). However, the high metabolic activity of rapidly proliferating cancer cells can compete for nutrients with immune cells in the TME, and consequently, suppressing their anti-tumor functions. Thus, therapeutic strategies could aim to restore T cell metabolism and anti-tumor responses in the TME by targeting the metabolic dependence of cancer cells. In this review, we highlight current research progress on metabolic reprogramming and the interplay between cancer cells and immune cells. We also discuss potential therapeutic intervention strategies for targeting metabolic pathways to improve cancer immunotherapy efficacy.

Evaluating the adequacy of nodal status in node-negative gallbladder cancer with T1b-T2 stages: use of nodal staging score.

BACKGROUND: The study aimed at establishing a nodal staging score (NSS) to quantify the likelihood that pathologic node-negative gallbladder cancer (GBC) patients are indeed free of lymph node (LN) metastasis. METHODS: Clinicopathological data of 1374 GBC patients with T1b-T2 stages were collected from the Surveillance, Epidemiology and End Result database (design cohort [DC], n = 1289) and the First Affiliated Hospital of Sun Yat-sen University (validation cohort [VC], n = 85). NSS was derived from the count of examined LNs (ELNs) and T stage by using a beta-binomial model, and represented the probability that a node-negative patient is correctly staged. The prognostic value of NSS in node-negative GBC was evaluated by survival analysis. RESULTS: The probability of missing a nodal disease in node-negative GBC patients with T1b-T2 stages (pT1bN0 and pT2N0) decreased as the number of ELNs increased. NSS increased as the number of ELNs increased. For pT1bN0 and pT2N0 patients, examination of 5 and 27 lymph nodes could ensure an NSS of 90.0%, respectively. Multivariate analysis revealed that NSS was an independent predictor for overall survival in pT1bN0 and pT2N0 GBC patients (DC, HR:0.53, 95%CI: 0.42-0.66, p < 0.001; VC, HR: 0.33, 95%CI: 0.14-0.76, p = 0.009). CONCLUSION: NSS could evaluate the adequacy of nodal staging and predict the prognosis in pT1bN0 and pT2N0 GBC patients, and hence was helpful to guide their treatment strategies.

[Unique characteristics of "the second brain" - The enteric nervous system].

Enteric nervous system (ENS) is composed of intestinal submucosal and myenteric plexuses. ENS may independently regulate intestinal digestive and absorptive function, and it is also known as "the second brain" or gut brain. ENS has significant specificity relative to central nervous system (CNS) in properties and functional activities of neurons and neural circuits. ENS is connected with CNS through the feedback pathway (brain-gut-axis) of sympathetic and parasympathetic nerves and peripheral primary sensory afferent nerves to form the bidirectional brain-gut-axis, which may affect emotion, appetite and behavioral states of individuals. Gastrointestinal functional disorder (GIFD) induced by ENS dysfunction may not only cause abnormal gastrointestinal function but also has been implicated in cognitive and mood disorders, such as irritable bowel syndrome (IBS). GIFD would influence deeply the quality of life in patients. Nevertheless, in the worldwide, ENS has so far received much less attention as compared with CNS. The depth of research and scale of investment in ENS studies have been much lower than those in CNS studies. The situation in China is even more evident. From ENS research history, an outstanding problem is to ignore largely the unique properties of ENS and apply mechanically the hypotheses formed in CNS studies to ENS researches. In this review, the structure and function of ENS are briefly introduced, and the importance of extraordinary characteristics of ENS is illustrated by the problems encountered in our studies.

Impact of enhanced recovery after surgery protocol on pancreaticoduodenectomy: a meta-analysis of non-randomized and randomized controlled trials.

BACKGROUND: Enhanced recovery after surgery (ERAS) has been widely applied in many surgical specialties. However, with respect to the impact of ERAS on pancreaticoduodenectomy (PD), there still exist some controversies. METHODS: Literature search was performed in PubMed, Web of Science and the Cochrane Library from January, 1990 to July, 2019. A meta-analysis was performed using fixed-effects or random-effects models. RESULTS: Twenty-two studies containing 4147 patients were identified. The entire pooled data showed that ERAS significantly reduced overall and minor morbidity (RR: 0.80, 95% CI: 0.72-0.88, p < 0.001; RR: 0.78, 95% CI: 0.69-0.88, p < 0.001, respectively), but didn't affect major morbidity (RR: 0.97, 95% CI: 0.84-1.13, p = 0.72). ERAS markedly reduced the incidences of delayed gastric emptying (DGE) (RR: 0.69, 95% CI: 0.55-0.88, p = 0.002), incisional infection (RR: 0.75, 95% CI: 0.60-0.94, p = 0.01) and intra-abdominal infection (RR: 0.79, 95% CI: 0.63-1.00, p = 0.05), but didn't influence clinically-relevant postoperative pancreatic fistula (CR-POPF) (RR: 0.86, 95% CI: 0.73-1.01, p = 0.07). Shorter length of stay (LOS) (WMD: -5.07, 95% CI: -6.71 to -3.43, p < 0.001) was noted in ERAS group, without increasing 30-day readmission (RR: 1.03, 95% CI: 0.86-1.24, p = 0.71) and mortality (RR: 0.70, 95% CI: 0.41-1.21, p = 0.20). CONCLUSION: ERAS significantly reduced overall and minor morbidity, incidences of DGE, incisional and intra-abdominal infections, and shortened LOS in PD, without increasing 30-day readmission and mortality. However, more large-scale randomized controlled trials are still needed to confirm the findings.

An Improved Strategy for Fluorescent Tagging of Membrane Proteins for Overexpression and Purification in Mammalian Cells.

An essential prerequisite for in vitro biochemical or structural studies is a construct that is amenable to high level expression and purification and is biochemically "well-behaved". In the field of membrane protein research, the use of green fluorescent protein (GFP) to monitor and optimize the heterologous expression in different hosts has radically changed the ease of streamlining and multiplexing the testing of a large number of candidate constructs. This is achieved by genetically fusing the fluorescent proteins to the N- or C-terminus of the proteins of interest to act as reporters which can then be followed by methods such as microscopy, spectroscopy, or in-gel fluorescence. Nonetheless, a systematic study on the effect of GFP and its spectral variants on the expression and yields of recombinant membrane proteins is lacking. In this study, we genetically appended four common fluorescent protein tags, namely, mEGFP, mVenus, mCerulean, and mCherry, to the N- or C-terminus of different membrane proteins and assessed their expression in mammalian cells by fluorescence-detection size exclusion chromatography (FSEC) and protein purification. We find that, of the four fluorescent proteins, tagging with mVenus systematically results in higher expression levels that translates to higher yields in preparative purifications, thus making a case for switching to this yellow spectral variant as a better fusion tag.

Sources and health risks of polycyclic aromatic hydrocarbons during haze days in eastern China: A 1-year case study in Nanjing City.

The concentrations of 16 priority polycyclic aromatic hydrocarbons (PAHs) in ambient air were investigated for a 1-year period to assess their sources and health risks during haze days in Nanjing City, eastern China. The highest level of total PAHs (∑16 PAHs) in the gaseous phase during the haze days was 18.0±13.3µg/m3. Their sources may be attributable to pyrogenic products (55.2%), petrochemical refining industry (8.7%), and petrol volatilization (36.1%). The incremental lifetime cancer risk during the haze days exceeded or was close to the priority level of risk (10-4), indicating that PAH pollution during the haze days has caused public health problems associated with the respiratory system. The priority PAHs in the particle phase are mainly composed of low-ring components (<4 rings), accounting for 65.2-96.8% of the ∑16 PAHs during haze days. These particles are derived from petroleum hydrocarbons (16.5%), incomplete combustion of gasoline (62.2%), and burning of coal and biomass (21.4%). The priority level of risk fell within an acceptable range (10-7-10-6). The PAHs in suspended particles can be transported to the surfaces of vegetables by gravitational deposition, causing an increase in PAH concentrations in vegetable leaves. The increased carcinogenic risk associated with human dietary intake was 6.9×10-5 for S. oleracea, 1.7×10-5 for B. pekinensis, and 6.2×10-6 for B. chinensis. These levels were close to the critical value (10-4), and the potential health risks from dietary intake of PAHs should be prioritized.

ß-Nicotinamide adenine dinucleotide acts at prejunctional adenosine A1 receptors to suppress inhibitory musculomotor neurotransmission in guinea pig colon and human jejunum.

Intracellular microelectrodes were used to record neurogenic inhibitory junction potentials in the intestinal circular muscle coat. Electrical field stimulation was used to stimulate intramural neurons and evoke contraction of the smooth musculature. Exposure to ß-nicotinamide adenine dinucleotide (ß-NAD) did not alter smooth muscle membrane potential in guinea pig colon or human jejunum. ATP, ADP, ß-NAD, and adenosine, as well as the purinergic P2Y1 receptor antagonists MRS 2179 and MRS 2500 and the adenosine A1 receptor agonist 2-chloro-N6-cyclopentyladenosine, each suppressed inhibitory junction potentials in guinea pig and human preparations. ß-NAD suppressed contractile force of twitch-like contractions evoked by electrical field stimulation in guinea pig and human preparations. P2Y1 receptor antagonists did not reverse this action. Stimulation of adenosine A1 receptors with 2-chloro-N6-cyclopentyladenosine suppressed the force of twitch contractions evoked by electrical field stimulation in like manner to the action of ß-NAD. Blockade of adenosine A1 receptors with 8-cyclopentyl-1,3-dipropylxanthine suppressed the inhibitory action of ß-NAD on the force of electrically evoked contractions. The results do not support an inhibitory neurotransmitter role for ß-NAD at intestinal neuromuscular junctions. The data suggest that ß-NAD is a ligand for the adenosine A1 receptor subtype expressed by neurons in the enteric nervous system. The influence of ß-NAD on intestinal motility emerges from adenosine A1 receptor-mediated suppression of neurotransmitter release at inhibitory neuromuscular junctions.