Evaluation of NOx emissions before, during, and after the COVID-19 lockdowns in China: A comparison of meteorological normalization methods.

Meteorological normalization refers to the removal of meteorological effects on air pollutant concentrations for evaluating emission changes. There currently exist various meteorological normalization methods, yielding inconsistent results. This study aims to identify the state-of-the-art method of meteorological normalization for characterizing the spatiotemporal variation of NOx emissions caused by the COVID-19 pandemic in China. We obtained the hourly data of NO2 concentrations and meteorological conditions for 337 cities in China from January 1, 2019, to December 31, 2020. Three random-forest based meteorological normalization methods were compared, including (1) the method that only resamples meteorological variables, (2) the method that resamples meteorological and temporal variables, and (3) the method that does not need resampling, denoted as Resample-M, Resample-M&T, and Resample-None, respectively. The comparison results show that Resample-M&T considerably underestimated the emission reduction of NOx during the lockdowns, Resample-None generates widely fluctuating estimates that blur the emission recovery trend during work resumption, and Resample-M clearly delineates the emission changes over the entire period. Based on the Resample-M results, the maximum emission reduction occurred during January to February 2020, for most cities, with an average decrease of 19.1 ± 9.4% compared to 2019. During April of 2020 when work resumption initiated to the end of 2020, the emissions rapidly bounced back for most cities, with an average increase of 12.6 ± 15.8% relative to those during the strict lockdowns. Consequently, we recommend using Resample-M for meteorological normalization, and the normalized NO2 concentration dynamics for each city provide important implications for future emission reduction.

Electrocatalytic CO2 Reduction and H2 Evolution by a Copper (II) Complex with Redox-Active Ligand.

The process of electrocatalytic CO2 reduction and H2 evolution from water, regarding renewable energy, has become one of the global solutions to problems related to energy consumption and environmental degradation. In order to promote the electrocatalytic reactivity, the study of the role of ligands in catalysis has attracted more and more attention. Herein, we have developed a copper (II) complex with redox-active ligand [Cu(L1)2NO3]NO3 (1, L1 = 2-(6-methoxypyridin-2-yl)-6-nitro-1h-benzo [D] imidazole). X-ray crystallography reveals that the Cu ion in cation of complex 1 is coordinated by two redox ligands L1 and one labile nitrate ligand, which could assist the metal center for catalysis. The longer Cu-O bond between the metal center and the labile nitrate ligand would break to provide an open coordination site for the binding of the substrate during the catalytic process. The electrocatalytic investigation combined with DFT calculations demonstrate that the copper (II) complex could homogeneously catalyze CO2 reduction towards CO and H2 evolution, and this could occur with great performance due to the cooperative effect between the central Cu (II) ion and the redox- active ligand L1. Further, we discovered that the added proton source H2O and TsOH·H2O (p-Toluenesulfonic acid) could greatly enhance its electrocatalytic activity for CO2 reduction and H2 evolution, respectively.

Semen quality and windows of susceptibility: A case study during COVID-19 outbreak in China.

BACKGROUND: To evaluate the impact of air pollution exposure on semen quality parameters during COVID-19 outbreak in China, and to identify potential windows of susceptibility for semen quality. METHODS: A retrospective observational study was carried out on 1991 semen samples collected between November 23, 2019 and July 23, 2020 (a period covering COVID-19 lock-down in China) from 781 sperm donor candidates at University-affiliated Sichuan Provincial Human Sperm Bank. Multivariate mixed-effects regression models were constructed to investigate the relationship between pollution exposure, windows of susceptibility, and semen quality, while controlling for biographic and meteorologic confounders. RESULT(S): The results indicated multiple windows of susceptibility for semen quality, especially sperm motility, due to ambient pollution exposure. Exposure to particulate matters (PM2.5 and PM10), O3 and NO2 during late stages of spermatogenesis appeared to have weak but positive association with semen quality. Exposure to CO late in sperm development appeared to have inverse relationship with sperm movement parameters. Exposure to SO2 appeared to influence semen quality throughout spermatogenesis. CONCLUSION(S): Potential windows of susceptibility for semen quality varied depending on air pollutants. Sperm motility was sensitive to pollution exposure. Findings from current study further elucidate the importance of sensitive periods during spermatogenesis and provide new evidence for the determinants of male fertility.

High-quality welding of glass by a femtosecond laser assisted with silver nanofilm.

Glass products with high joint strength are highly demanded in the field of microelectromechanical system (MEMS). While the quality requirement of MEMS is getting higher and higher, much attention has been paid to further improving the welding strength of the glass. Herein, a femtosecond laser welding method assisted by silver nanofilm for quartz glass is proposed. To optimize the welding results, the influence of the laser power on the location of the heat-affected zone is studied. The effect of coated silver nanofilm at the interface of two glass substrates on femtosecond laser absorptivity is conducted. Also, the welding spot size under different irradiation periods is investigated. In addition, the welding strength with and without the silver nanofilm is measured and compared. It is demonstrated that the welding strength was increased nearly 20% on average by our proposed method compared with direct femtosecond laser welding. In addition, even at the lower laser power than the welding threshold, the welding process could be realized by the proposed method.

Novel cytotoxic exhibition mode of antimicrobial peptide anoplin in MEL cells, the cell line of murine Friend leukemia virus-induced leukemic cells.

Anoplin is a recently discovered antimicrobial peptide (AMP) isolated from the venom sac of the spider wasp Anoplius samariensis, and it is one of the shortest α-helical AMP found naturally to date consisting of only ten amino acids. Previous results showed that anoplin exhibits potent antimicrobial activity but little hemolytic activity. In this study, we synthesized anoplin, studied its cytotoxicity in Friend virus-induced leukemia cells [murine erythroleukemia (MEL) cells], and proposed its possible mechanism. Our results showed that anoplin could inhibit the proliferation of MEL cells in a dose-dependent and time-dependent manner via disrupting the integrity of cell membrane, which indicated that anoplin exerts its cytotoxicity efficacy. In addition, the cell cycle distribution of MEL cells was arrested in the G0/G1 phase significantly. However, anoplin could not induce obvious apoptosis in MEL cells, as well as anoplin could not induce visible changes on morphology and quantity in the bone marrow cells isolated from normal mice. All of these results indicate that anoplin, as generally believed, is a selective AMP, a value characteristic in the design of safe therapeutic agents. The cytotoxicity of anoplin on MEL cells was mainly attributable to the plasma membrane perturbation and also to the intracellular events such as the arrest of cell cycle. Although this is an initial study that explored the activity of anoplin in vitro rather than in vivo, with the increasing resistance of conventional chemotherapy, there is no doubt that anoplin has desirable feature to be developed as a novel and selective anticancer agent.

[Application experience of prelacrimal recess combined with septotomy in resection of recurrent inverted papilloma].

Objective:To investigate the effectiveness of nasal endoscopic anterior lacrimal recess approach combined with temporary fenestration of the nasal septum in resecting recurrent nasal inverted papilloma. Methods:Patients with recurrent nasal inverted papilloma who underwent reoperation in our hospital during the past 2 years were included . The nasal septum may hinder full access to and effective treatment of the lesions at the anterior and medial wall of the maxillary sinus by endoscope, aspirator and surgical instrument in the narrow aperture of the prelacrimal recess, although these lesions could be observed by 70° nasal endoscope. Results:The nasal septum is temporarily opened on the basis of the prelacrimal recess approach, and the nasal endoscope and instrument was introduced through trans-septal window, so as to provide a better view of the operative field and the angular range of the instrument's movement. Conclusion:The recurrent nasal inverted papilloma could be successfully managed by re-endoscopic anterior lacrimal recess approach combined with temporary fenestration of the nasal septum, and no recurrence was observed during the 2-year follow-up. This surgical approach is recommended for the inverted papilla which originates from the anterior medial wall of the maxillary sinus, as the tumor can be removed completely using this surgical approach.

Chemically Welding Silver Nanowires toward Transferable and Flexible Transparent Electrodes in Heaters and Double-Sided Perovskite Solar Cells.

Silver nanowires (AgNWs) are important materials for flexible transparent electrodes (FTEs). However, the loose stacking of nanowire junctions greatly affects the electric conductivity across adjacent nanowires. Soldering can effectively reduce the wire-wire contact resistance of AgNWs by epitaxially depositing nanosolders at the junctions, but the process normally needs to be performed with high energy consumption. In this work, we proposed a simple room-temperature method to achieve precise welding of junctions by adjusting the wettability of the soldered precursor solution on the surfaces of AgNWs. The nanoscale welding at nanowire cross junctions forms efficient conductive networks. Furthermore, reduced graphene oxide (rGO) was used to improve the stability of FTEs by wrapping the rGO around the AgNW surface. The obtained FTE shows a figure-of-merit (FoM) of up to 439.3 (6.5 Ω/sq at a transmittance of 88%) and has significant bending stability and environmental and acidic stability. A flexible transparent heater was successfully constructed, which could reach up to 160 °C within a short response time (43 s) and exhibit excellent switching stability. When laminating this FTE onto half perovskite solar cells as the top electrodes, the obtained double-side devices achieved power conversion efficiencies as high as 16.15% and 13.91% from each side, pointing out a convenient method for fabricating double-sided photovoltaic devices.

A data-augmentation approach to deriving long-term surface SO2 across Northern China: Implications for interpretable machine learning.

Until recently, Northern China was one of the most SO2 polluted regions in the world. The lack of long-term and spatially resolved surface SO2 data hinders retrospective evaluation of relevant environmental policies and human health effects. This study aims to derive the spatiotemporal distribution of surface SO2 across Northern China during 2005-2019. As "concept drift" causes substantial estimation bias in back-extrapolation, we propose a new approach named the robust back-extrapolation via data augmentation approach (RBE-DA) to model the long-term surface SO2. The results show that the population-weighted regional SO2 ([SO2]pw) increased from 2005 to 2007 and decreased steadily afterwards. The [SO2]pw decreased by 80.4% from 74.2 ± 28.4 µg/m3 in 2007 to 14.6 ± 4.8 µg/m3 in 2019. The predicted spatial distributions for each year show that the SO2 pollution was severe (more than 20 µg/m3) in most areas of Northern China until 2017. By using model interpretation methods, we visually reveal the mechanism of estimation bias in the back-extrapolation. Specifically, the training data is severely imbalanced with respect to the satellite-retrieved SO2 column densities (i.e., it is short on high-value samples), so the benchmark model is unable to extrapolate the effects of this important predictor. This study provides long-term surface SO2 data for post hoc evaluation and human exposure assessment in Northern China, while demonstrating that the interpretable machine learning approach is critical for model diagnostics and refinement. Leveraging satellite retrievals, the RBE-DA approach can be applied worldwide to back-extrapolate various measures of air quality.

[Clinical application of nasal mucosa flap in the repair of nasopharyngeal skull base bone exposure after radiotherapy for nasopharyngeal carcinoma].

Objective:To observe the effect of nasal mucosa flap in the repair of nasopharyngeal skull base bone exposure after radiotherapy for nasopharyngeal carcinoma, and to provide a basis for the repair with nasal mucosa flap in skull base bone exposure after radiotherapy. Methods:The clinical data of 8 patients who underwent nasal endoscopic surgery were analyzed retrospectively. The survival of mucosal flap, the mucosal epithelialization of bone defect or exposed site, the improvement of main clinical symptoms and complications were followed up after operation. Results:Severe mucosal flap necrosis and bone exposure occurred in 1 case after operation, in the other 7 cases, the mucosal flap survived and the mucosal epithelium of nasopharynx recovered well. After operation, most of the patients' clinical symptoms such as headache and nasal odor were improved compared with those before operation. Conclusion:Nasal mucosal flap is a safe and minimally invasive autogenous material with good biocompatibility. It has a good application prospect in repairing bone defect or exposure of nasopharyngeal skull base after radiotherapy and is worth popularizing in clinic.

A robust approach to deriving long-term daily surface NO2 levels across China: Correction to substantial estimation bias in back-extrapolation.

BACKGROUND: Long-term surface NO2 data are essential for retrospective policy evaluation and chronic human exposure assessment. In the absence of NO2 observations for Mainland China before 2013, training a model with 2013-2018 data to make predictions for 2005-2012 (back-extrapolation) could cause substantial estimation bias due to concept drift. OBJECTIVE: This study aims to correct the estimation bias in order to reconstruct the spatiotemporal distribution of daily surface NO2 levels across China during 2005-2018. METHODS: On the basis of ground- and satellite-based data, we proposed the robust back-extrapolation with a random forest (RBE-RF) to simulate the surface NO2 through intermediate modeling of the scaling factors. For comparison purposes, we also employed a random forest (Base-RF), as a representative of the commonly used approach, to directly model the surface NO2 levels. RESULTS: The validation against Taiwan's NO2 observations during 2005-2012 showed that RBE-RF adequately corrected the substantial underestimation by Base-RF. The RMSE decreased from 10.1 to 8.2 µg/m3, 7.1 to 4.3 µg/m3, and 6.1 to 2.9 µg/m3 in predicting daily, monthly, and annual levels, respectively. For North China with the most severe pollution, the population-weighted NO2 ([NO2]pw) during 2005-2012 was estimated as 40.2 and 50.9 µg/m3 by Base-RF and RBE-RF, respectively, i.e., 21.0% difference. While both models predicted that the national annual [NO2]pw increased during 2005-2011 and then decreased, the interannual trends were underestimated by >50.2% by Base-RF relative to RBE-RF. During 2005-2018, the nationwide population that lived in the areas with NO2 > 40 µg/m3 were estimated as 259 and 460 million by Base-RF and RBE-RF, respectively. CONCLUSION: With RBE-RF, we corrected the estimation bias in back-extrapolation and obtained a full-coverage dataset of daily surface NO2 across China during 2005-2018, which is valuable for environmental management and epidemiological research.

Self-reported reasons for treatment non-adherence in Chinese asthma patients: A 24-week prospective telephone follow-up study.

BACKGROUND: Treatment non-adherence is a challenge to achieve asthma control. However, few prospective studies were done for exploring asthma patient adherence in real world. OBJECTIVES: To evaluate treatment adherence and causes of non-adherence in a large asthma Chinese population. To analyze newly-diagnosed patients' adherence first time. METHODS: About 1582 asthma patients' data were collected from 12 study centers in China from February, 2012 to October, 2012. Disease and treatment information of subjects were collected were at first clinic visit, at 4, 12, and 24 weeks after that, follow-up phone calls were carried out for recording subjects' treatment adherence based on their self-reports. Subjects who reported non-adherence were additionally asked to choose the primary non-adherence cause from a list of nine potential causes. RESULTS: Treatment adherence rate of all subjects markedly decreased from 83.3% at week 4 to 42.0% at week 24 after the first clinic visit. Significantly, at week 24, good treatment adherence rate in newly-diagnosed patients was lower than those patients with asthma history (22.9% vs. 63.9%, P < .001). Newly-diagnosed patients were three times more likely to become non-adherence than those patients with asthma history. Female patients had lower treatment adherence rate than male patients (38.3% vs. 45.6%, P = .006). Subjects in 30-39 year age group had the worst treatment adherence (27.3%). The most commonly chosen cause for non-adherence was "relief of symptoms after short-term controller medication use" (43.8%). CONCLUSIONS: Asthma patients' treatment adherence could be improved by improving patient education, doctor/patient partnership, and level of medical service in Chinese population.

The novel protein C9orf116 promotes rat liver cell line BRL-3A proliferation.

Our previous study has proved that the chromosome 9 open reading frame 116 (C9orf116) (NM_001106564.1) was significantly up-regulated in the proliferation phase of liver regeneration. To study its possible physiological function, we analyzed the effect of C9orf116 on BRL-3A cells via over-expression and interference technique. MTT results showed that the cell viability of the interference group was significantly lower than the control group at 48h after transfection (P<0.05), whereas it was significantly higher in the over-expression group (P<0.05). The flow cytometry results showed that C9orf116 knockdown or over-expression had little effect on BRL-3A cell apoptosis. However, the number of cells in division phase (G2/M) was significantly reduced in the interference group (P<0.05), but significantly increased in the over-expression group (P<0.01). Furthermore, the expressions of cell proliferation-related genes CCNA2, CCND1 and MYC both at mRNA and protein levels were down-regulated in the interference group and up-regulated in the over-expression group. Therefore, we concluded that C9orf116 may promote cell proliferation by modulating cell cycle transition and the expression of key genes CCNA2, CCND1 and MYC in BRL-3A cells.

[Effect of kebimin decoction on serum levels of adhesion molecule and Th1/Th2 cytokines in patients with allergic rhinitis].

OBJECTIVE: To investigate the mechanisms of Kebimin decoction (KD) in treating allergic rhinitis (AR). METHODS: Sixty patients with AR were randomly divided into two groups, patients in the treated group (TG) were treated with KD, those in the control group (CG) were given Xinfang rhinitis capsule. The serum levels of adhesion molecule (sICAM-1, P-selectin), Th1 cytokines, including interferon-gamma (IFN-gamma) and interleukin-2 (IL-2), and Th2 cytokines (IL-4 and IL-5) were determined by enzyme-linked immunosorbent assay (ELISA) before and after treatment, and compared with those in 30 healthy subjects as control. RESULTS: The serum levels of adhesion molecule and Th2 cytokines were higher and Th1 cytokines were lower in AR patients than those in healthy control (P < 0.01). After treatment, these indexes were restored significantly (P < 0.01) in the treated group, but no significant change was found in the control group. CONCLUSION: KD has definite effect in treating allergic rhinitis by inhibiting production of adhesion molecule and regulating the levels of Th1/Th2 cytokines to correct the imbalanced Th1/Th2 cytokines network.

[Experimental study of spirulina platensis in treating allergic rhinitis in rats].

OBJECTIVE: To determine the therapeutic effect of spirulina platensis in allergic rhinitis (AR). METHODS: Ovalbumin sensitized white rats used as AR animals were treated with spirulina platensis (SPP). At the end of the treatment, the differences in the behavior science were observed; the changes in the nasal mucosa and mast cell degranulation were studied pathologically; and the levels of serum histamine and total immunoglobulin (Ig) E were determined by enzyme-linked immune sorbent assay. RESULTS: The behavior science score of the SPP treatment group was lower than that of the negative control group (P < 0.01 ) ; inflammatory reaction of nasal mucosa in the SPP treatment group were remarkably relieved; the number of nasal mucosa mastocyte and mast cell degranulation in the SPP treatment group were lower than that of the negative control group (P <0.01 ). The levels of serum histamine and total IgE in the SPP treatment group were lower than that of the negative control group (P <0.01 ). It had no significant difference in the positive control group and the SPP treatment group and the blank control group (P > 0.05 ). CONCLUSION: Spirulina platensis can prevent and treat AR in rats, which implies the possibility of using spirulina platensis for AR patients in the future.

Quick preparation of nanoluciferase-based tracers for novel bioluminescent receptor-binding assays of protein hormones: Using erythropoietin as a model.

Nanoluciferase (NanoLuc) is a newly developed small luciferase reporter with the so far brightest bioluminescence. In recent studies, we developed NanoLuc as an ultrasensitive probe for novel bioluminescent receptor-binding assays of some protein/peptide hormones. In the present study, we proposed a simple method for quick preparation of the NanoLuc-based protein tracers using erythropoietin (Epo) as a model. Epo is a glycosylated cytokine that promotes erythropoiesis by binding and activating the cell membrane receptor EpoR. For quick preparation of a bioluminescent Epo tracer, an Epo-Luc fusion protein carrying a NanoLuc-6 × His-tag at the C-terminus was secretorily overexpressed in transiently transfected human embryonic kidney (HEK) 293 T cells. The Epo-Luc fusion protein retained high-binding affinities with EpoR either overexpressed in HEK293T cells or endogenously expressed in mouse erythroleukemia cells, representing a novel ultrasensitive bioluminescent tracer for non-radioactive receptor-binding assays. Sufficient Epo-Luc tracer for thousands of assays could be quickly obtained within 2 days through simple transient transfection. Thus, our present work provided a simple method for quick preparation of novel NanoLuc-based bioluminescent tracers for Epo and some other protein hormones to facilitate their ligand-receptor interaction studies.

New designed HMBA agents as inducers of erythroleukemia cell differentiation.

OBJECTIVE: Searching for more potent and less toxic HMBA-related agents. METHODS: Human erythroleukemia cell K562, murine erythroleukemia cell (MEL) and its sub-line MEL DS19 were used as target cells to select a cell line which is the most sensitive to HMBA, then analyzed the activity of inducing differentiation of two new designed HMBA derivatives: HMBPA [hexamethylenebi (3-pyridin) amide] and Co-HDTA (ethylenediaminetetra acetic acid cobalt) using cell biology, cytochemical and molecular biology techniques. RESULTS: We found that the MEL DS19 cells were most sensitive to HMBA (benzidine positive, B+ approximately 76%). Co-HDTA can inhibit the growth of MEL DS19, but induces differentiation just in a small population (B+ 2% approximately 4.5%). Between 0.02 approximately 5 micromol/L, HMBPA induces 3% approximately 8% cells committed to differentiation with little inhibition of cell proliferation. 1 micromol/L HMBPA and 2 mmol/L HMBA together, can obviously increase the percentage of differentiated cell (B+ approximately 72%), inhibit DNA synthesis and accelerate beta-globin transcription. CONCLUSION: The new HMBA derivatives may provide potential cancer differentiation inducers.

[Effect of kebimin decoction in treating allergic rhinitis and on blood levels of nitric oxide and superoxide dismutase].

OBJECTIVE: To observe the therapeutic effect of Kebimin decoction (KD) on allergic rhinitis (AR) and its effect on blood levels of nitric oxide (NO) and superoxide dismutase (SOD) activity. METHODS: Eighty-two AR patients were randomly divided into two groups, the treated group and the control group, 41 in each group. To the treated group, KD was given one dose per day for 10 days as one therapeutic course and 1-3 courses were given successively. The control group was treated with Xinfang Rhinitis capsule for 30 days. Blood levels were determined and compared before and after treatment. RESULTS: The total effective rate in the treated group was 93%, which was better than that in the control group (51%), the difference was significant (chi 2 = 17.704, P < 0.01). Serum level of NO was higher and that of SOD activity was lower in the AR patients than that in healthy persons (P < 0.01), KD could significantly lower the former and increase the latter (P < 0.01). CONCLUSION: The therapeutic effect of KD in treating AR was significant, its mechanism might be related with the lowering of NO and increasing of SOD activity in serum, as well as the scavenging of oxygen free radical.

[Analysis of the level and significance of IL-16 and IL-17 in nasal secretion and in serum of patients with allergic rhinitis and non-allergic rhinitis].

OBJECTIVE: To test the immunoglobulin free light chain (FLC) from nasal secretion and serum of patients with allergic rhinitis(AR)and non-allergic rhinitis(NAR) for the purpose of exploring the possible immunological mechanism. METHOD: Ninety consecutive patients were selected between January 2009 and January 2012, involving 45 patients with AR and 45 patients with NAR diagnosed by symptoms,signs,skin prick tests(SPT) and specific IgE (slgE). Forty-five volunteers were chosen as healthy control (HC). According to the visual analogue scale (VAS) scores,the nasal symptoms of AR and NAR,including sneeze. Nasal discharge. Nasal obstruction and nasal itching were compared. ELISA was used to detect the total IgE, IL-16, IL-17 in nasalsecretion and serum. The data was analyzed by SPSS 17.0 software. RESULT: There was no statistical difference between AR and NAR group in nasal symptoms (P > 0.05); In serum, IL-16 and IL-17 increased in AR group comparared to NAR group (P < 0.05); IL-16 and IL-17 increased in NAR group comparared to HC group (all P < 0.05); In nasal secretion, IL-16 and IL-17 increased in NAR and AR group comparared to HC group (all P < 0.05). CONCLUSION: IL-16, IL-17 takes part in the path of physiological process of AR and NAR with the immunological mechanism.

Hemokinin-1(4-11)-induced analgesia selectively up-regulates δ-opioid receptor expression in mice.

Our previous studies have shown that an active fragment of human tachykinins (hHK-1(4-11)) produced an opioid-independent analgesia after intracerebroventricular (i.c.v.) injection in mice, which has been markedly enhanced by a δ OR antagonist, naltrindole hydrochloride (NTI). In this study, we have further characterized the in vivo analgesia after i.c.v. injection of hHK-1(4-11) in mouse model. Our qRT-PCR results showed that the mRNA levels of several ligands and receptors (e.g. PPT-A, PPT-C, KOR, PDYN and PENK) have not changed significantly. Furthermore, neither transcription nor expression of NK1 receptor, MOR and POMC have changed noticeably. In contrast, both mRNA and protein levels of DOR have been up-regulated significantly, indicating that the enhanced expression of δ opioid receptor negatively modulates the analgesia induced by i.c.v. injection of hHK-1(4-11). Additionally, the combinatorial data from our previous and present experiments strongly suggest that the discriminable distribution sites in the central nervous system between hHK-1(4-11) and r/mHK-1 may be attributed to their discriminable analgesic effects. Altogether, our findings will not only contribute to the understanding of the complicated mechanisms regarding the nociceptive modulation of hemokinin-1 as well as its active fragments at supraspinal level, but may also lead to novel pharmacological interventions.

Involvement of RbAp48 in erythroid differentiation of murine erythroleukemia cells induced by sodium butyrate.

Normal mammalian terminal erythroid differentiation is a precisely regulated process during which the progenitor cells execute particular programs to form a mature erythrocytic phenotype. In the present study, it was found that RbAp48, a histone-binding protein associated with retinoblastoma protein, was upregulated during terminal erythroid maturation in vivo and in vitro. This indicated that RbAp48, at least in part, participated in the regulation of murine erythropoiesis. Following sodium butyrate (SB) induction, murine erythroleukemia (MEL) cells began to re-enter erythroid differentiation and the ratio of differentiated cells reached ~80% at 72 h. The erythroid maturation-related mRNA expression of α-globin, ß-globin and glycophorin A (GPA) was increased markedly, which indicated that SB induced MEL differentiation. During MEL differentiation, the RbAp48 level showed a 1.5-fold increase at 72 h, and the globin transcription factor (GATA)-1 level was also upregulated in the early stage of differentiation. By contrast, the c-Myc level was gradually downregulated in MEL differentiation. Using an immunofluorescence assay, the results of the study directly showed that the average fluorescence intensity of RbAp48 in each cell reached an almost 1.7-fold increase at 72 and 96 h. This was consistent with the western blot results of RbAp48 during MEL differentiation. In addition, reduced expression of RbAp48 by RNA inference decreased SB-induced MEL differentiation by ~20%, indicating that a high level of RbAp48 was essential for MEL differentiation. Taken together, these results established a functional link between RbAp48 and erythroid differentiation.