Uncovering the Power of HSCCC: Separation of Diastereomeric and Regioisomeric Styrylpyrones from the Stem Bark of Goniothalamus leiocarpus.

The plant Goniothalamus leiocarpus of the Annonaceae family is used as an alternative medicine in tropical regions. Applying high-speed counter current chromatography (HSCCC), eight new bioactive styrylpyrone isomers, including 6R,7S,8R,2'S-goniolactone B (1), 6S,7S,8S,2'S-goniolactone B (2), 6R,7R,8R,2'S-goniolactone B (3), 6R,7S,8S,2'S-goniolactone C (4), 6R,7S,8R,2'S-goniolactone C (5), 6S,7R,8S,2'S-goniolactone C (6), and two positional isomers, 6R,7R,8R,2'S-goniolactone G (7) and 6S,7R,8R,2'S-goniolactone G (8), were isolated from a chloroform fraction (2.1 g) of G. leiocarpus, which had a prominent spot by TLC analysis. The structures of the new compounds were elucidated by MS, NMR, IR, and UV spectra, and their absolute configurations were determined by Mosher's method, ECD, and X-ray diffraction analysis. The isolates are characteristic components found in plants of the genus Goniothalamus and consist of two structural moieties: a styrylpyrone and a dihydroflavone unit. The isolation of the eight new compounds demonstrates the effectiveness of HSCCC in separating the isomers of natural styrylpyrone. In a bioactivity assessment, compounds 1 and 6 exhibited cytotoxic effects against the human colon carcinoma cell lines LS513 and SW620 with IC50 values ranging from 1.6 to 3.9 µM. Compounds 1, 2, 7, and 8 showed significant synergistic activity against antibiotic-resistant Staphylococcus aureus strains.

Reduced PATL2 Impairs the Proliferation of Ovarian Granulosa Cells by Decreasing ADM2 Expression in Patients with PCOS.

It is recognized that PCOS patients are often accompanied with aberrant follicular development, which is an important factor leading to infertility in patients. However, the relevant regulatory mechanisms of abnormal follicular development are not well understood. In the present study, by collecting human ovarian granulosa cells (GCs) from PCOS patients who underwent in vitro fertilization (IVF), we found that the proliferation ability of GCs in PCOS patients was significantly reduced. Surprisingly, PATL2 and adrenomedullin 2 (ADM2) were obviously decreased in the GCs of PCOS patients. To further explore the potential roles of PATL2 and ADM2 on GC, we transfected PATL2 siRNA into KGN cells to knock down the expression of PATL2. The results showed that the growth of GCs remarkably repressed after knocking down the PATL2, and ADM2 expression was also weakened. Subsequently, to study the relationship between PATL2 and ADM2, we constructed PATL2 mutant plasmid lacking the PAT construct and transfected it into KGN cells. The cells showed the normal PATL2 expression, but attenuated ADM2 expression and impaired proliferative ability of GCs. Finally, the rat PCOS model experiments further confirmed our findings in KGN cells. In conclusion, our study suggests that PATL2 promoted the proliferation of ovarian GCs by stabilizing the expression of ADM2 through "PAT" structure, which is beneficial to follicular development, whereas, in the ovary with polycystic lesions, reduction of PATL2 could result in the decreased expression of ADM2, subsequently weakened the proliferation ability of GCs and finally led to the occurrence of aberrant follicles.

Forces driving transposable element load variation during Arabidopsis range expansion.

Genetic load refers to the accumulated and potentially life-threatening deleterious mutations in populations. Understanding the mechanisms underlying genetic load variation of transposable element (TE) insertion, a major large-effect mutation, during range expansion is an intriguing question in biology. Here, we used 1,115 global natural accessions of Arabidopsis (Arabidopsis thaliana) to study the driving forces of TE load variation during its range expansion. TE load increased with range expansion, especially in the recently established Yangtze River basin population. Effective population size, which explains 62.0% of the variance in TE load, high transposition rate, and selective sweeps contributed to TE accumulation in the expanded populations. We genetically mapped and identified multiple candidate causal genes and TEs, and revealed the genetic architecture of TE load variation. Overall, this study reveals the variation in TE genetic load during Arabidopsis expansion and highlights the causes of TE load variation from the perspectives of both population genetics and quantitative genetics.

Aberrant BMP15/HIF-1α/SCF signaling pathway in human granulosa cells is involved in the PCOS related abnormal follicular development.

AIMS: To investigate the regulatory mechanism of SCF expression in human GCs of PCOS related follicles. MATERIALS AND METHODS: SCF, BMP15 and HIF-1α were evaluated in human serums, follicular fluids (FFs) and GCs, which were collected from 69 PCOS patients and 74 normal ovulatory patients. KGN cell line was used in this study. RESULTS: Our results showed that the rate of MII oocyte and 2PN fertilization was lower in PCOS group, though PCOS patients retrieved much more oocytes. The level of BMP15 in FF and the level of SCF in serum and FF were also lower in PCOS patients. We found a weakened expression of HIF-1α and SCF in GCs from PCOS patients when compared with the non-PCOS patients. The expression of HIF-1α and SCF was significantly increased in KGN cells after treating cells with rhBMP15, however, this promotion effects of BMP15 on HIF-1α and SCF expression were obviously abolished by co-treatment with BMP-I receptor inhibitor (DM). Moreover, knock down of HIF-1α expression in KGN cells significantly reduced the expression of SCF in human GCs, in spite of activating BMP15 signaling pathway. CONCLUSIONS: The present study suggest that BMP15 could induce SCF expression by up-regulating HIF-1α expression in human GCs, the aberrance of this signaling pathway might be involved in the PCOS related abnormal follicular development.

A novel heterozygous variant in PANX1 is associated with oocyte death and female infertility.

PURPOSE: Oocyte death is a severe clinical phenotype that causes female infertility and recurrent in vitro fertilization and intracytoplasmic sperm injection failure. We aimed to identify pathogenic variants in a female infertility patient with oocyte death phenotype. METHODS: Sanger sequencing was performed to screen PANX1 variants in the affected patient. Western blot analysis was used to check the effect of the variant on PANX1 glycosylation pattern in vitro. RESULTS: We identified a novel PANX1 variant (NM_015368.4 c.86G > A, (p. Arg29Gln)) associated with the phenotype of oocyte death in a non-consanguineous family. This variant displayed an autosomal dominant inheritance pattern with reduced penetrance. Western blot analysis confirmed that the missense mutation of PANX1 (c.86G > A) altered the glycosylation pattern in HeLa cells. Moreover, the mutation effects on the function of PANX1 were weaker than recently reported variants. CONCLUSION: Our findings expand the inheritance pattern of PANX1 variants to an autosomal dominant mode with reduced penetrance and enrich the variational spectrum of PANX1. These results help us to better understand the genetic basis of female infertility with oocyte death.

Solute carrier family 2 members 1 and 2 as prognostic biomarkers in hepatocellular carcinoma associated with immune infiltration.

BACKGROUND: Metabolic reprogramming has been identified as a core hallmark of cancer. Solute carrier family 2 is a major glucose carrier family. It consists of 14 members, and we mainly study solute carrier family 2 member 1 (SLC2A1) and solute carrier family 2 member 2 (SLC2A2) here. SLC2A1, mainly existing in human erythrocytes, brain endothelial cells, and normal placenta, was found to be increased in hepatocellular carcinoma (HCC), while SLC2A2, the major transporter of the normal liver, was decreased in HCC. AIM: To identify if SLC2A1 and SLC2A2 were associated with immune infiltration in addition to participating in the metabolic reprogramming in HCC. METHODS: The expression levels of SLC2A1 and SLC2A2 were tested in HepG2 cells, HepG215 cells, and multiple databases. The clinical characteristics and survival data of SLC2A1 and SLC2A2 were examined by multiple databases. The correlation between SLC2A1 and SLC2A2 was analyzed by multiple databases. The functions and pathways in which SLC2A1, SLC2A2, and frequently altered neighbor genes were involved were discussed in String. Immune infiltration levels and immune marker genes associated with SLC2A1 and SLC2A2 were discussed from multiple databases. RESULTS: The expression level of SLC2A1 was up-regulated, but the expression level of SLC2A2 was down-regulated in HepG2 cells, HepG215 cells, and liver cancer patients. The expression levels of SLC2A1 and SLC2A2 were related to tumor volume, grade, and stage in HCC. Interestingly, the expression levels of SLC2A1 and SLC2A2 were negatively correlated. Further, high SLC2A1 expression and low SLC2A2 expression were linked to poor overall survival and relapse-free survival. SLC2A1, SLC2A2, and frequently altered neighbor genes played a major role in the occurrence and development of tumors. Notably, SLC2A1 was positively correlated with tumor immune infiltration, while SLC2A2 was negatively correlated with tumor immune infiltration. Particularly, SLC2A2 methylation was positively correlated with lymphocytes. CONCLUSION: SLC2A1 and SLC2A2 are independent therapeutic targets for HCC, and they are quintessential marker molecules for predicting and regulating the number and status of immune cells in HCC.

GnRH antagonist weakens endometrial stromal cells growth ability by decreasing c-kit receptor expression.

BACKGROUND: Several surveys have reported that patients treated with gonadotropin-releasing hormone antagonist (GnRH-ant) protocol showed a significantly lower rate of implantation and clinical pregnancy compared to GnRH agonist (GnRH-a) protocol during in vitro fertilization-fresh embryo transfer. Subsequent studies imputed this poor outcome to the negative effects of GnRH-ant on endometrial receptive. However, the mechanisms were not fully understood. METHODS: The clinical data of 2815 patients undergoing fresh embryo transfer in our center were analyzed. Human endometrial stromal cells (ESCs) from healthy women undergoing elective pregnancy termination of a normal pregnancy at 8-10 weeks gestation were treated with GnRH-analogs or imatinib (c-kit receptor inhibitor). CCK8 and Flow cytometry were used to investigated the growth ability of ESCs. Immunofluorescence staining and western blot was used to detected the target proteins. RESULTS: The clinical data showed that the endometrial thickness on HCG Day were significantly lower in GnRH-ant group. Although no difference of embryo quality in these two groups, GnRH-ant group showed remarkably decreased rate of HCG positive, embryo implantation and pregnancy. Moreover, GnRH-ant significantly reduced the proliferation and induced the apoptosis of ESCs. Furthermore, the expression and activation of c-kit receptor, which played pivotal roles during embryo implantation, were observably decreased by GnRH-ant. Inhibiting the activation of c-kit by imatinib remarkably suppressed the proliferation and promoted the apoptosis of ESCs. Additionally, the phosphorylation of AKT and expression of Cyclin D1, which were closely related with cellular growth, were distinctly lessened after treating with imatinib. CONCLUSIONS: In summary, our study showed that GnRH-ant weakened the activization of c-kit receptor by decreasing its expression, causing the impaired growth ability of ESCs. Our findings provided a new insight into the effects of GnRH-ant on endometrium.

UPLC-MS/MS method for the determination of the herb composition of Tangshen formula and the in vivo pharmacokinetics of its metabolites in rat plasma.

INTRODUCTION: Tangshen formula (TSF) is a traditional Chinese medicine composed of seven medicinal herbs including Astragalus membranaceus, Rehmannia glutinosa Libosch, Citrus aurantium L., etc. which is used to treat diabetic nephropathy III, IV qi and yin deficiency and stasis syndrome. Most of the studies on TSF are pharmacological and pharmacodynamic experiments. There are few basic studies on its chemical substances, and the effective constituents are not clear. OBJECTIVE: To analyse the main chemical components of TSF and the absorbed components in rat plasma following oral administration based on liquid chromatography tandem mass spectrometry (LC-MS/MS). Moreover, providing a rapid and valid analytical strategy for simultaneous determination of six components in rat plasma and use it in pharmacokinetic studies. RESULTS: A total of 132 components were identified in TSF, and 44 components were identified in rat plasma after oral TSF, 35 of which were prototype components and nine were metabolic components. A sensitive and reliable LC-MS/MS method was developed for simultaneous determination of six components in rat plasma. The intra-day and inter-day precision relative standard deviation (RSD) was lower than 15%; the accuracy of low, medium and high concentrations ranged from 80% to 120%. The recovery met the requirements and the RSD of the recoveries was less than 15%. CONCLUSION: A total of 132 components were identified in TSF. The LC-MS/MS quantitative method for the simultaneous determination of morroniside, loganin, notoginsenoside R1 , ginsenoside Re, ginsenoside Rb1 and astragaloside IV in rat plasma was established for the first time. The pharmacokinetic parameters are clarified, which can guide the clinical medication of TSF.

Meta-analysis of the association between sclerostin level and adverse clinical outcomes in patients undergoing maintenance haemodialysis.

BACKGROUND: Studies regarding the relationship of sclerostin (Scl) with clinical outcomes in patients undergoing maintenance haemodialysis have yielded controversial findings. This meta-analysis was performed to investigate the predictive role of Scl in this patient population. METHODS: Several electronic medical databases (e.g. PubMed, Embase, Web of Science and Cochrane Library) were searched for eligible studies through December 20, 2019. Summary hazard ratios (HRs) with 95% confidence intervals (CIs) were calculated based on Scr level (high or low) using a random or fixed effects model. RESULTS: From among 641 initially screened publications, 16 eligible studies were included in this meta-analysis. A high Scl level was not associated with cardiovascular events [HR = 0.8 (95% CI, 0.42-1.35)] or all-cause mortality [HR = 0.93 (95% CI, 0.56-1.54)]. There was high heterogeneity, but no evidence of publication bias. Interestingly, a high Scl level was associated with reduced cardiovascular events [HR = 0.44 (95% CI, 0.29-0.69)] in the subgroup by shorter follow-up period or all-cause mortality [pooled HR = 0.58 (95% CI, 0.36-0.91)] by shorter dialysis vintage. CONCLUSION: This meta-analysis indicated that a high Scl level did not predict total clinical outcomes in patients undergoing maintenance haemodialysis despite survival benefits in the subgroups. The predictive role of Scl in these patients should be further evaluated in large prospective studies.

C-kit signaling promotes human pre-implantation 3PN embryonic development and blastocyst formation.

BACKGROUND: Although in vitro culture system has been optimized in the past few decades, the problem of few or no high quality embryos has been still not completely solved. Accordingly, fully understanding the regulatory mechanism of pre-implantation embryonic development would be beneficial to further optimize the in vitro embryo culture system. Recent studies have found the expression of c-kit in mouse embryo and its promotion effects on mouse embryonic development. However, it is unclear the expression, the role and the related molecular regulatory mechanism of c-kit in human pre-implantation embryo development. Therefore, the present study is to determine whether c-kit is expressed in human pre-implantation embryos, and to investigate the possible regulatory mechanism of c-kit signaling in the process of embryonic development. METHODS: The present study includes human immature oocytes and three pronucleus (3PN) embryos collected from 768 women (28-32 ages) undergoing IVF, and normal 2PN embryos collected from ICR mice. Samples were distributed randomly into three different experimental groups: SCF group: G-1™ (medium for culture of embryos from the pro-nucleate stage to day 3) or G-2™ (medium for culture of embryos from day3 to blastocyst stage) + HSA (Human serum album) solution + rhSCF; SCF + imanitib (c-kit inhibitor) group: G-1™ or G-2™ + HSA solution + rhSCF + imanitib; SCF + U0126 (MEK/ERK inhibitor) group: G-1™ or G-2™ + HSA solution + rhSCF + U0126; Control group: G-1™ or G-2™ + HSA solution + PBS; The rate of good quality embryos at day 3, blastulation at day 6 and good quality blastulation at day 6 were analysis. RT-PCR, western blot and immunofluorescence staining were applied to detect the target genes and proteins in samples collected from human or mice, respectively. RESULTS: c-kit was expressed ubiquitously in all human immature oocytes, 3PN embryos and 3PN blastocysts. In the experiment of human 3PN embryos, compared with other groups, SCF group showed obviously higher rate of good quality at day 3, better rate of blastocyst formation at day 6 and higher rate of good quality blastocyst formation at day 6. Furthermore, we observed a higher ETV5 expression in SCF group than that in other groups. Similar results were also found in animal experiment. Interestingly, we also found a higher phosphorylation level of MEK/ERK signal molecule in mice embryos from SCF group than those from other groups. Moreover, inhibition of MEK/ERK signaling would remarkably impeded the mice embryonic development, which might be due to the reduced ETV5 expression. CONCLUSIONS: The present study firstly revealed that c-kit signaling might promote the human pre-implantation embryonic development and blastocyst formation by up-regulating the expression of ETV5 via MEK/ERK pathway. Our findings provide a new idea for optimizing the in vitro embryo culture condition during ART program, which is beneficial to obtain high quality embryos for infertile patients.

[Comparisons Between Seasonal and Diurnal Patterns of Cave Air CO2 and Control Factors in Jiguan Cave, Henan Province, China].

Cave air CO2 makes notable impacts on the deposition and dissolution of speleothem,affecting the stability of carbonate landscape and comfort of tourist in show caves.Cave air CO2 is a key factor of karstification occurrence.Studying the mechanism of cave air CO2 variation is important for understanding the pattern of karstification and cave protection.In order to understand the temporal and spatial variation characteristics and its possible controlling factors,inside and outside cave air CO2,hydrogeochemical index,temperature,relative humidity as well as precipitation and tourist amount were observed in the Jiguan Cave,which lies in the west Henan Province of south-north geographical boundary of China.Nearly five years monitoring of air CO2 of Jiguan Cave was carried out from December,2011 to May,2016.A diurnal monitoring was performed from 19 May,2016 to 20 May,2016.The results indicated that the cave air CO2 showed notable spatial and seasonal variations.① From the spatial variation,the sites closer to cave entrances,affected by strong cave ventilation,had lower pCO2.In addition,the special structure of Jiguan Cave and soil air pCO2 variation,vegetation respiration and soil microbial activity,which in turn were associated with changes in climate and environment also contributed to the variation of cave air pCO2.② On a seasonal scale,cave air CO2 was higher in summer and lower in winter.This variation of cave air CO2 was mainly influenced by tourism activity as well as karstification.③ Tourist amount was the mainly factor that influenced the variation of cave air CO2 on a daily scale.Because of tourism activity,cave air CO2 was increased,and also cave environment was disturbed.All of these intimidate the better conservation of cave environment.

[High-resolution Variations of Oxygen and Hydrogen Isotopes of Precipitation and Feedback from Cave Water: An Example of Jiguan Cave, Henan].

The stable isotopes of atmospheric precipitation that affect the isotopes of speleothem and cave water are controlled by a variety of factors, such as temperature, rainfall amount, altitude, vapor source and others. Knowledge in the factors causing rainfall stable isotopes change is one of the keys to understanding the cave water stable isotopes change of monsoon-sensitive area in the north-south China intersection. The samples collected from 4 ground water sites in Jiguan Cave and the instantaneous heavy rain during Aug.4th-6th, 2015 were analyzed, and combined with the precipitation oxygen and hydrogen isotopes data for samples from almost 6 years (2009-2015) collected in Jiguan Cave of Luanchuan County in Henan Province, leading to the following findings:① The precipitation was divided into 2 stages with different vapor sources (high-altitude water vapor from the South China Sea and inland areas from near the ground to evaporate moisture) that could be recorded in the δ18O of single rainfall by HYSPLIT model. ② The evaporation of stage 2 masked the temperature effect to some extent, which also decreased the slope and intercept of LMWL and d-excess of precipitation. ③ The δ18O values feature of cave drip water in Jiguan Cave during this rainfall was mainly a response to the summer monsoon precipitation from sea source vapor. The cave drip water of Jiguan Cave responded to the heavy rain very quickly, and the time was ~3 h. The δ18O of drip became heavier when dripping rate increased and then decreased slowly. The same pattern could be found in underground river with slight delay, and the pool near the cave entrance reflected the difference of precipitation δ18O in two stages.

[Response and Control Factors of Groundwater to Extreme Weather, Jiguan Cave, Henan Province, China].

Geochemical dynamics of cave water were monitored to unveil its variation and controlling factors from October 2009 to December 2013 in Jiguan Cave,west of Henan province,southeastern coast of the loess plateau. The results showed that: (1) the hydrochemical types of the cave water are HCO(3-)-Ca(2+)-Mg2+ and HCO(3-)-Mg(2+)-Ca2+. HCO(3-) are over 80% of the anions, Ca2+ and Mg2+ are the dominate cations, and ground river keeping in erosion and pool water drips in deposition all the year. (2) Dripping water and pool water in Ji guan cave can respond perfectly to the change of external climate environment, which geochemistry indexes possess the extraordinary seasonal effects. (3) The concentration changes of the Ca2+, Mg2+ , SO4(2-) responded sensitively to annual precipitation change. Ca2+, Mg2+, SO4(2-) rise in waterlogging year and fall in drought year. Because HCO(3-) controlled by CO2 concentration. HCO(3-) concentration showed a unconspicuous response to the change of external climate environment. (4) The concentration changes of Ca2+, Mg2+, SO4(2-) have no obvious seasonal variation and showed a unconspicuous response to the change of external climate environment.

Vulvovaginal candidiasis: species distribution, fluconazole resistance and drug efflux pump gene overexpression.

The increasing incidence of vulvovaginal candidiasis (VVC) and the emergence of fluconazole resistance are an indisputable fact. However, little information is available regarding the correlation between fluconazole resistance in vaginal Candida albicans and the expression of drug efflux pump genes. In this study, we investigated the species distribution, fluconazole susceptibility profiles and the mechanisms of fluconazole resistance in Candida strains. In total, 785 clinical Candida isolates were collected from patients with VVC. C. albicans was the most frequently isolated species(n = 529) followed by C. glabrata (n = 164) and C. krusei (n = 57). Of all Candida isolates, 4.7% were resistant to fluconazole. We randomly selected 18 fluconazole resistant isolates of C. albicans to evaluate the expression of CDR1, CDR2, MDR1 and FLU1 genes. Compared with fluconazole-susceptible C. albicans isolates, CDR1 gene expression displayed 3.16-fold relative increase, which was statistically significant. CDR2, MDR1 and FLU1 overexpression was observed in several fluconazole-resistant C. albicans isolates, but statistical significance was not achieved. These results demonstrate a high frequency of non-albicans species (32.6%); however, C. albicans is the most common Candida species implicated in vaginitis, and this strain displays considerable fluconazole resistance. Meanwhile, our study further indicates that fluconazole resistance in C. albicans may correlate with CDR1 gene overexpression.

Molecular cloning and expression analysis of chymotrypsin-like serine protease from the redclaw crayfish (Cherax quadricarinatus): a possible role in the junior and adult innate immune systems.

A novel chymotrypsin-like serine protease (CLSP) was isolated from the hepatopancreas of the redclaw crayfish Cherax quadricarinatus (Cq-chy). The full-length cDNA of Cq-chy contains 951 nucleotides encodes a peptide of 270 amino acids. The mature peptide comprising 223 amino acids contains the conserved catalytic triad (H, D, and S). Similarity analysis showed that Cq-chy shares high identity with chymotrypsins from the fiddler crab; Uca pugilator. Cq-chy mRNA expression in C. quadricarinatus was shown to be: (a) tissue-related with the highest expression in the hepatotpancreas and widely distributed, (b) highly responsive in the hepatopancreas to White Spot Syndrome Virus (WSSV) challenge, and (c) differently regulated in immature and adult crayfish. In this study we successfully isolated Cq-chy. Our observations indicate that Cq-chy is differently involved in the immature and adult innate immune reactions, thus suggesting a role for CLSPs in the invertebrate innate immune system.

[Association between particulate air pollution and daily respiratory and cardiovascular hospital admissions].

OBJECTIVE: To establish concentration-response relationship model for high particulate air pollution and daily hospital admissions for early warning system. METHODS: The Poisson generalized additive model was used with natural cubic spline smoothing for air pollutants of PM10, SO2, NO2, CO to determine the shape of concentration-response relationship. And piecewise linear regression was used for risk analysis. RESULTS: Age-specific analysis suggested the non-linear association between particulate air pollution and hospital admissions in all age groups. In respiratory and cardiovascular admissions, the percentage increase was 0.716%-2.145% and 0.65% for 10 microg/m3 increase in PM10, respectively. Cause-specific analysis suggested the non-linear association between particulate air pollution and hospital admissions for all diseases. The significant association was found with COPD and ischaemic heart disease, and the related percentage increase was 2.94% and 1.94%, respectively. Heating and noheating period analysis suggested the effect of PM10 was higher in noheating period than that in heating period. CONCLUSION: Compared with mortality, particulate air pollution should affect the hospital admissions more greatly, the percentage increase should be higher for hospital admissions than that of mortality (0.25%).

Synthesis and biological evaluation of the mitochondrial complex 1 inhibitor 2-[4-(4-fluorobutyl)benzylsulfanyl]-3-methylchromene-4-one as a potential cardiac positron emission tomography tracer.

A series of fluorinated chromone analogs with IC50 values ranging from 9 to 133 nM for the mitochondrial complex 1 (MC-I) has been prepared. A structure-activity relationship (SAR) study of the most potent fluorinated chromone analog 10 demonstrated the linkage heteroatom preference of the side chain region of the molecule while maintaining potent MC-I inhibitory activity. Tissue distribution studies 30 min after [(18)F]10 administration to Sprague-Dawley (SD) rats demonstrated high uptake of the radiotracer from the blood pool into the myocardium (2.24% ID/g), kidney (1.93% ID/g), and liver (2.00% ID/g). After 2 h about 66% of the activity in the myocardium at 30 min had been retained, whereas approximately 70% had been cleared from the liver and kidney. MicroPET images of SD rats after [(18)F]10 administration allowed easy assessment of the myocardium through 60 min with minimal lung or liver interference.

ACh-evoked membrane hyperpolarization in smooth muscle cells of rat vas deferens in vitro: involvement of K(+) channels and NO.

To explore the underlying mechanism of acetylcholine (ACh)-evoked membrane hyperpolarizing response in isolated rat vas deferens smooth muscle cells (SMCs), intracellular microelectrode recording technique and intracellular microelectrophoresis fluorescent staining technique were used to study ACh-evoked membrane hyperpolarizing response in SMCs freshly isolated from Wistar rat vas deferens. By using microelectrodes containing fluorescent dye 0.1% propidium iodide (PI), 37 and 17 cells were identified as SMCs in outer longitudinal and inner circular muscular layers, respectively. The resting membrane potentials of SMCs were (-53.56+/-3.88) mV and (-51.62+/-4.27) mV, respectively. The membrane input resistances were (2245.60+/-372.50) MOmega and (2101.50+/-513.50) MOmega, respectively. ACh evoked membrane hyperpolarizing response in a concentration-dependent manner with an EC(50) of 36 micromol/L. This action of ACh was abolished by both a non-sepcific muscarinic (M) receptor antagonist atropine (1 mumol/L) and a selective M(3 ) receptor antagonist diphenylacetoxy-N-methylpiperidine-methiodide (DAMP, 100 nmol/L). ACh-evoked membrane hyperpolarization was also abolished by a nitric oxide synthase inhibitor N-nitro-L-arginine methyl ester (L-NAME, 300 micromol/L) and suppressed by an ATP-sensitive potassium (K(ATP)) channel blocker glipizide (5 micromol/L) and an inward rectifier potassium (K(ir)) channel inhibitor bariumion (50 micromol/L). A combination of glipizide and bariumion abolished ACh-evoked membrane hyperpolarizing response. The results suggest that ACh-evoked membrane hyperpolarization in rat vas deferens SMCs is mediated by M(3) receptor followed with activation of K(ATP) channels, K(ir) channels, and NO release.

[Concentration-response relationship between particulate air pollution and daily mortality in Taiyuan].

OBJECTIVE: To further study concentration-response relationship between daily mortality and particulate air pollution, to provide scientific basis for making policy. METHODS: We applied spline model to daily time-series data for Taiyuan city, China from 2004-2005, using concentration of particulate matter less than 10 microm in aerodynamic diameter (PM10) as the exposure measure, and controlling confounding factors, such as season, meteorological factors, day-of-the-week, other air pollutions, etc. RESULTS: The spline model showed a nonlinear relationship for the relative risks of death for all causes (total deaths) and for specific causes in relation to PM10 concentration, and obtained threshold levels. For total mortality, malignant tumor mortality and cardiovascular-cerebrovascular-respiratory mortality, the threshold levels were 85.00 microg/m3, 89.59 microg/m3, 122.54 microg/m3, respectively using the value of differential deduction. CONCLUSION: Our nonlinear models are appropriate for assessing the effect of particulate air pollution on daily mortality at current ambient levels in Taiyuan, China,in contrast to those of Europe and America.

Modulatory effect of CCK-8S on GABA-induced depolarization from rat dorsal root ganglion.

CCK is a brain-gut peptide that is abundantly distributed in both gastrointestinal tract and mammalian brain. The sulfated octapeptide fragment of cholecystokinin (CCK-8S) has been shown to be involved in numerous physiological functions such as behavior, anxiety, learning/memory processes and neuropathic pain. CCK-8S is one of the strongest endogenous anti-opioid substances and suppresses opioid peptides-mediated 'pre-synaptic inhibition' of gamma-aminobutyric acid (GABA) release. Here we provide evidence that CCK-8S modulates GABA-evoked membrane depolarization in rat dorsal root ganglion (DRG) neurons using intracellular recording technique. Bath application CCK-8S-induced membrane depolarization in most of the rat DRG neurons. The depolarization was blocked by prolumide but not LY225910. Pretreatment with CCK-8S suppressed the GABA-evoked depolarization in a concentration-dependent manner. The CCK-8S inhibition was also time-dependent and reached the peak at about 2 min. The inhibitory effect of CCK-8S was strongly suppressed by pre-incubation of CCK-B receptor antagonist LY225910, phospholipase C inhibitor U73122, protein kinase C inhibitor chelerythrine and calcium chelator BAPTA-AM, respectively. The protein kinase A inhibitor H-89 did not affect CCK-8S effect. The results suggest that CCK-8S inhibits GABA-A receptor function by activation of CCK-B receptor followed by activation of intracellular PLC-Ca(2+)-PKC cascade. Thus, CCK-8S might enhance nociceptive information transmission through inhibition of the "pre-synaptic inhibition" evoked by GABA, which may explain its role in modulation of primary sensory information (especially pain).