Spatiotemporal characteristics of ozone and the formation sensitivity over the Fenwei Plain

High surface ozone (O₃) levels affect human and environmental health. The Fenwei Plain (FWP), one of the critical regions for China's "Blue Sky Protection Campaign", has reported severe O₃ pollution. This study investigates the spatiotemporal properties and the causes of O₃ pollution over the FWP using high-resolution data from the TROPOspheric Monitoring Instrument (TROPOMI) from 2019 to 2021. This study characterizes spatial and temporal variations in O₃ concentration by linking O₃ columns and surface monitoring using a trained deep forest machine learning model. O₃ concentrations in summer were 2-3 times higher than those found in winter due to higher temperatures and greater solar irradiation. The spatial distributions of O₃ correlate with the solar radiation showing decreased trends from the northeastern to the southwestern FWP, with the highest O₃ values in Shanxi Province and the lowest in Shaanxi Province. For urban areas, croplands and grasslands, the O₃ photochemistry in summer is NO_x-limited or in the transitional regime, while it is VOC-limited in winter and other seasons. Reducing NO_x emissions would be effective for decreasing O₃ levels in summer, while VOC reductions are necessary for winter. The annual cycle in vegetated areas included both NO_x-limited and transitional regimes, indicating the importance of NO_x controls to protect ecosystems. The O₃ response to limiting precursors shown here is of importance for optimizing control strategies and is illustrated by emission changes during the 2020 COVID-19 outbreak.

[Efficacy and safety of transcatheter aortic valve replacement in the treatment of severe aortic stenosis]

Objective: To investigate the efficacy and safety of transcatheter aortic valve replacement (TAVR) in the treatment of severe aortic stenosis. Methods: The clinical data of patients with severe aortic stenosis who underwent TAVR at the People's Hospital of Xinjiang Uygur Autonomous Region between September 2016 and September 2022 were retrospectively analyzed. Changes in aortic transvalvular pressure gradients, valve orifice area, and activity tolerance of patients before and after the surgery were compared. Moreover, postoperative complications and follow-up results from 30 days to 6 years after the surgery were recorded. Results: A total of 76 patients were included in the study (50 males and 26 females), with an average age of (71.3±7.6) years, including 16 rheumatic valvular diseases, 60 senile degenerative diseases, 46 bicuspid valves and 30 tricuspid valves. The success rate of the operation was 96.1% (73/76). Compared with that before the operation, the mean aortic transvalvular pressure gradients decreased [(8.5±2.8) mmHg vs (68.5±19.2) mmHg (1 mmHg=0.133 kPa),P<0.001], but the valve orifice area increased [(1.91±0.31) cm² vs (0.65±0.21) cm², P<0.001]. Likewise, six-minute walking test (6MWT) showed that walking distance was longer after the surgery [(430±13) m vs (201±28) m, P<0.001]. There were 1 case of retroperitoneal hematoma, 1 case of stricture balloon dilatation after femoral artery suture concomitant with postoperative puncture site infection, 1 case of femoral artery surgical incision, 2 cases of valve-in-valve (ViV) and 5 cases of perivalvular leakage (4 cases were mild and 1 case was moderate) after the surgery, respectively. Moreover, acute left main artery occlusion during operation occurred in 1 case, ventricular rupture during operation occurred in 1 case and the patient was transferred to valve replacement surgery and finally dead, delayed coronary artery occlusion and death happened in 1 case, and all of the above-mentioned 3 cases were due to surgical failure. Postoperative pacemaker implantation due to third-degree atrioventricular block was performed in 5 cases. There were 1 case of pulmonary embolism, 1 case of transient right limb disorder, 1 case of gastrointestinal bleeding and 1 case of urethral bleeding after the surgery, respectively. The patients were followed up for (1.0±0.1) years (30 days to 6 years), and the results showed that 2 cases died, including 1 case died suddenly at home (the cause of death was unknown) and 1 case died of acute heart failure 8 months after the surgery. Chronic heart failure occurred repeatedly in 6 cases. The quality of life of other patients improved significantly. Conclusion: TAVR is effective and safe for patients with severe aortic stenosis.

Large-scale turbulence structures in a laboratory-scale boundary layer under steady and gusty wind inflows

Experiments on turbulence structures and features of a wind field under steady inflow and gusty wind inflows were implemented in a straight-through wind tunnel. Streamwise and wall-normal velocity components were measured using a streamline constant temperature anemometer (streamline CTA). Power spectra analyses revealed the existence of very large-scale motions (VLSMs) under both steady and gusty wind inflows; but new gusty scale motions (GSMs) were revealed under only gusty wind inflows. The GSMs might originate from an ordered external driving force that forces hairpin packets to align coherently in groups with a length scale related to the gust inflow condition. The streamwise wavelength of VLSMs is independent of inflow conditions, while the turbulent energy of VLSMs is associated with the wall-normal height and local mean streamwise velocity. In particular, the streamwise wavelength of GSMs increases linearly with the average value and period of sinusoidal gusty wind inflows, and the turbulent energy of GSMs is sensitive to the wall-normal height and all characteristic parameters of gusty wind inflows, including the average value, amplitude and period. Considerable wall-normal airflows induced by gusty wind inflows were detected and these are negatively correlated with the variation in gusty streamwise velocity, and root mean square (RMS) values of the gusty wall-normal velocity tended to increase linearly with the average value and amplitude of gusty wind inflows.

Identification and characterization of microRNA from chicken adipose tissue and skeletal muscle

MicroRNA (miRNA) is small noncoding RNA that is extensively expressed in organisms. Different types play important roles in various biological processes, such as growth and development. In this study, we identified 47 miRNA in chicken adipose tissue and skeletal muscle, of which 38 were known chicken miRNA, 4 were known miRNA homologous to other species, and 5 were potentially novel miRNA. The target genes from adipose tissue and skeletal muscle were predicted. The expression assay indicated that the 10 selected miRNA were differentially expressed in different developmental stages. Both miRNA-133a and miR-1a were muscle-related, whereas miR-122 was adipose-related miRNA. Certain identified miRNA may be essential to growth and development of chicken adipose tissue and skeletal muscle. Further studies of these miRNA will help to understand their functions in growth and development of adipose tissue and skeletal muscle of poultry.

Identification of single nucleotide polymorphisms in the CCNA2 gene and its association with wool density in Rex rabbits

The Rex rabbit is a typical fur breed. Wool density, hair length, wool fineness, and hide area are the main indices of fur quality. We previously found that the CCNA2 gene plays an important role in hair follicle initiation and development, and it is involved in the distinctive wool density of the Rex rabbit. It is an important candidate gene for wool density selection through marker-assisted selection. We conducted an association study to identify single nucleotide polymorphisms (SNPs) within the CCNA2 gene and their ligands associated with wool density. Using PCR-RFLP technology, we discovered two SNPs (129G>A and 1140G>C) of the CCNA2 gene. Allele frequencies of these two SNPs were investigated and evaluated by the χ(2) test in 100 Rex rabbits. The two SNPs were both in Hardy-Weinberg equilibrium. We also looked for a potential association of these SNPs with fur traits in 100 Rex rabbits. Rex rabbits with the GG genotype had significantly higher wool density (P < 0.01) than those with other genotypes; the other three fur traits did not differ significantly among the genotypes. In conclusion, the two SNPs of the CCNA2 gene affect wool density in the Rex rabbit.

Genetic variation of chicken MC1R gene in different plumage colour populations

1. Genetic variation in the chicken MC1R gene was analysed through bioinformatic methods after polymerase chain reaction (PCR) amplification and sequencing of the coding region of MC1R gene from 5 different populations with 4 plumage colours (black, grey plumage with black spots, yellow plumage with black spots, red). 2. A total of 11 novel variations were detected in Hebei chickens, of which 8 were non-synonymous. Allele distribution analysis showed that the wild-type e(+) (Brown Leghorn) allele was mainly found in Hy-Line Brown and Lohmann Brown, the dominant Extended black E(AY220304) allele was mainly found in Hebei chicken with black plumage, whereas the Buttercup (e(bc)) allele was rare. 3. Nucleotide diversity (π) within each colour strain of Hebei chickens (0·0047-0·0052) was significantly greater than that of Hy-Line Brown (0·0024) or Lohmann Brown (0·0043). 4. The results indicate that there is abundant polymorphism in the MC1R gene, especially in Hebei chicken, which was associated with its rich plumage colour diversity.

Inhibitory effect of osthole on alcohol-induced fatty liver in mice

BACKGROUND

Alcohol is a major cause of fatty liver, the disease is a spectrum that is initiated with steatosis, and without therapy it is apt to develop inflammation, necrosis, fibrosis and finally cirrhosis. There are currently no ideal pharmacological reagents that can prevent or reverse this disease. Osthole is an active constituent isolated from the fruit of Cnidium monnieri (L.) Cusson, a Chinese herbal medicine, which has been used in clinics for many years. It has many functions such as anti-inflammation, anti-osteoporosis and anti-tumor and so on, but there is no report about treatment of alcoholic fatty liver in mice.

AIM

To examine the inhibitory effect of osthole on alcohol-induced fatty liver in mice and to investigate the potential mechanisms.

METHODS

A mouse model with alcoholic fatty liver was induced by orally feeding 52% erguotou wine by gavage when they were simultaneously treated with osthole 10, 20, 40 mg/kg for 4 weeks. Whereafter, the lipids in serum and hepatic tissue, the levels of malondialdehyde (MDA), superoxide dismutase (SOD), reduced glutathione hormone (GSH), tumor necrosis factor-alpha (TNF-alpha) in hepatic tissue, hepatic weight coefficient and its histological evaluation were measured.

RESULTS

After treatment with osthole, the levels of serum total cholesterol (TC), triglyceride (TG), coefficient of hepatic weight, and the hepatic tissue contents of TC and TG were significantly decreased, the levels of MDA and TNF-alpha in liver were also decreased, while the GSH in liver was increased. Importantly, the histological evaluation of liver specimens demonstrated that osthole dramatically decreased lipid accumulation.

CONCLUSION

Osthole could inhibit alcohol-induced fatty liver in mice, and the mechanism might be associated with its anti-oxidation and suppression of TNF-alpha production.

Effects of dietary copper (II) sulfate and copper proteinate on performance and blood indexes of copper status in growing pigs

160 crossbred (Duroc x Landrace x Yorkshire) gilts averaged 21.25 kg body weight were used to study the effects of dietary copper (II) sulfate (CuSO4) and copper proteinate (Cu-Pr) on growth performance, plasma Cu concentration, ceruloplasmin activity, and erythrocyte Cu/Zn-superoxide dismutase (SOD) activity. All pigs were allotted to four treatments and fed with basal diets supplemented with 0 (control), 250 mg /kg Cu as CuSO4, and 50 and 100 mg/kg Cu as Cu-Pr. Growth performance was determined based on two growth phase (phase 1: days 0 to 15, phase 2: days 15 to 30). After 30 days of the treatment, 16 pig blood samples (four per treatment) were collected for indexes of copper status determination. The experimental results showed that compared with control, pigs fed with 250 mg Cu/kg as CuSO4 and 100 mg Cu/kg as Cu-Pr had higher average daily gain and average daily feed intake in the whole growth phase (d 0 to 30). In addition, 250 mg Cu/kg as CuSO4 and 100 mg/kg Cu as Cu-Pr enhanced plasma ceruloplasmin activity (P < 0.05), and 100 mg/kg Cu as Cu-Pr increased erythrocyte Cu/Zn-SOD activity (P < 0.01) compared with the control. There was no obvious treatment response on plasma Cu concentration in the present study.

Differential expression of peroxisome proliferator-activated receptors alpha and gamma gene in various chicken tissues

The peroxisome proliferator-activated receptors (PPARs) are the members of superfamily of nuclear hormone receptors. A great number of studies in rodent and human have shown that PPARs were involved in the lipids metabolism. The goal of the current study was to investigate the expression pattern of PPAR genes in various tissues of chicken. The tissue samples (heart, liver, spleen, lung, kidney, stomach, intestine, brain, breast muscle and adipose) were collected from six Arber Acres broilers (8 weeks old, male and female birds are half and half). Semi-quantitative RT-PCR and Northern blot were used to characterize the expression of PPAR-alpha and PPAR-gamma genes in the above tissues. By semi-quantitative RT-PCR, the results showed the expression level of PPAR-alpha gene was higher in brain, lung, kidney, heart and intestine, medium in stomach, liver and adipose than in spleen, and it did not express in breast muscle. The expression level of PPAR-gamma gene was higher in adipose, medium in brain and kidney than in spleen, heart, lung, stomach and intestine, but it did not express in liver and breast muscle. Northern blot results showed that PPAR-alpha gene expressed in heart, liver, kidney and stomach, and the intensity of hybridization signal was the stronger in liver and kidney than in other tissues, however, PPAR-gamma gene only expressed in adipose and kidney tissues. The results of this study showed the profile of PPAR gene expression in the chicken was similar to that in rodent, human and pig. However the expression profile of chicken also have its own specific trait, i.e. compared with mammals, PPAR-alpha gene can not be detected in skeletal muscle and PPAR-gamma gene can be stronger expressed in kidney tissues. This work will provide some basic data for the PPAR genes expression and lipids metabolism of birds.

Inhibitory effect of quercetin on cultured neonatal rat cardiomyocytes hypertrophy induced by angiotensin

AIM

To study the inhibitory effect of quercetin on cultured neonatal rat cardiomyocytes hypertrophy induced by angiotensin II (AngII) and its mechanism.

METHODS

DNA, RNA, and protein synthesis were measured by incorporation of [3H]thymidine, [14C]uridine, and [3H]tyrosine, respectively. Protein content were measured by Lowry's method. Protein kinase C (PKC) activity was assayed by incubating PKC with histone IIIS and [gamma-(32)P]ATP. Tyrosine protein kinase (TPK) activity was assayed by incubating TPK with poly glutamate/tyrosine (4:1) and [gamma-(32P]ATP.

RESULTS

After treated with AngIIat 10 nmol/L for 24 h, total protein content was greatly increased as compared with untreated group (P < 0.01). Incorporation of [14C]uridine and [3H]tyrosine was also greatly increased (P < 0.01) respectively, while incorporation of [3H]thymidine remained unchanged (P > 0.05). Ang II strongly increased cardiomyocytes PKC and TPK activities at 30 min. Que (1-100 micromol/L) could inhibit the increase of total protein content, incorporation of [14C]uridine and [3H]tyrosine, and PKC and TPK activities induced by Ang II in concentration-dependent manner.

CONCLUSION

The inhibitory effect of Que on the cardiomyocytes hypertrophy was related to its inhibitory effect on PKC and TPK.

Effect of quercetin on adhesion of platelets to microvascular endothelial cells in vitro

AIM

To study the effect of quercetin(Que) on the adhesion of platelets to microvascular endothelial cells (MVEC) isolated from human skin.

METHODS

[3H]-adenine-labeled platelets were incubated with MVEC. Effect of Que on platelet endothelial cell adhesion molecular (PECAM) expression on MVEC was also evaluated using enzyme-linked immunosorbent assay (ELISA).

RESULTS

Adhesion of platelet to MVEC reached to maximum at about 30 min. Que inhibited the adhesion of platelets to MVEC in a concentration-dependent manner. Que 5 micromol/L did not show any significant inhibition. When the concentration of Que increased to 10, 20, and 40 micromol/L, the inhibition rate increased to 10.5 %, 20.0 %, and 42.2 %, respectively. Pre-incubation of Que (10 - 40 micromol/L) with labeled platelets for 30 min also inhibited the adhesion but Que 5 micromol/L did not. The inhibition rate of Que 10, 20, and 40 micromol/L was 18.2 %, 29.8 %, and 65.3 % respectively. Expression of PECAM on the endothelial cells was decreased in a concentration-dependent manner when MVEC were treated with Que (10 - 40 micromol/L) for 12 h but Que 5 micromol/L did not significantly affect the expression.

CONCLUSION

Que could inhibit the adhesion of platelets to MVEC. This effect may be related to decreased expression of PECAM on MVEC.

[The frequency distribution and establishment of fruit fly strain of segregation distorter in Drosophila melanogaster in China]

Segregation Distorter (SD) is a meiotic drive system of natural occurrence. Heterozygous SD/SD+ males transmit the SD chromosome in vast excess over the normal homolog. SD chromosomes have been recovered at low frequency (1%-5%) from almost every population that has been screened for them in many places of the world. To examine whether there is SD system in natural populations of Drosophila melanogaster in China, we surveyed a few populations of D. melanogaster in Beijing and Qingdao respectively. The results suggested that SD is also found in every population examined at frequency of 1%-5%. On the basis of learning distribution of SD in China, we established a fruit fly stoch of SD from wild population of D. melanogaster in Beianhe district of Beijing. Furthermore, instead of using traditional genetic hybridization, we used molecular approach, PCR, to examine the distribution of SD chromosomes, which has been proved a very effective, quick and convenient method.

Effect of lipanthyl on mRNA expression of endothelin-1 and nitric-oxide synthase in atherosclerotic vessel wall in rabbits

AIM

To study the mechanism of regression of atherosclerosis (AS) by lipanthyl.

METHODS

Experimental atherosclerotic rabbits created by damaging the abdominal aortic endothelium and feeding with high fat diet for 8 wk were then treated with lipanthyl 15 mg.kg-1.d-1 for 16 wk. Expression of endothelin (ET)-1 mRNA and nitric oxide synthase (NOS) mRNA in atherosclerotic vessel wall was measured by in situ hybridization and reverse transcription polymerase chain reaction (RT-PCR), respectively.

RESULTS

After lipanthyl administration for 16 wk, ET-1 mRNA expression was reduced, and integral optical density (IOD) and area of hybridization granule were observed to be (49,113 +/- 16,868) and (2448 +/- 621) micron 2 in lipanthyl group and (65,188 +/- 10,113) and (3028 +/- 352) micron 2 in atherosclerotic group, respectively. Regarding inducible NOS mRNA expression, IOD and area were decreased by 25.5% and 53.3%, respectively, whereas endothelial NOS mRNA expression was increased.

CONCLUSION

Restoration of the disturbed ET-1 mRNA/NOS mRNA balance by lipanthyl might be one of its mechanisms leading to regression of atherosclerosis.

Securinine induced apoptosis in human leukemia HL-60 cells

AIM

To study whether securinine might induce apoptosis in human leukemia HL-60 cells.

METHODS

Inhibition of proliferation was measured using MTT assay. The amount of apoptotic cells was measured by flow cytometry. DNA fragmentation was visualized by DNA agarose gel electrophoresis and the cellular changes were observed by electron microscope.

RESULTS

Securinine 5-80 mg.L-1 elicited typical apoptosis morphological changes and DNA fragmentation in a concentration-dependent manner in HL-60 cells. Securinine inhibited HL-60 cell proliferation in a time- and concentration-dependent manner. The IC50 and 95% confidence limits were 27 (15-47) mg.L-1 after 12-h treatment with securinine.

CONCLUSION

Securinine induced apoptosis in HL-60 cells.

Elemene induces apoptosis and regulates expression of bcl-2 protein in human leukemia K562 cells

AIM

To study the antitumor action of elemene (Ele) and its mechanism.

METHODS

Inhibition of proliferation was measured with a colorimetric 3-[4,5-dimethyl thiazol-2-yl]-2,5-diphenyltetrazolium bromide (MTT) assay. Morphological assessment of apoptosis was performed with fluorescence microscope. DNA fragmentation was assessed by agarose gel electrophoresis and flow cytometry. The levels of bcl-2 protein was measured with flow cytometry.

RESULTS

Exposure of exponentially growing K562 cells to Ele 65-520 mumol. L-1 for 48 h resulted in growth arrest. The values of IC50 and 95% confidence limits were 220 (152-319) mumol.L-1. After treatment of K562 cells with Ele 130 mumol.L-1, marked morphological changes including "Apo bodies" reduction in volume were observed with fluorescence microscope. Agarose gel electrophoresis of DNA from cells treated with Ele for 48 h revealed "ladder" pattern. The levels of bcl-2 protein in K562 cells treated with Ele for 48 h were obviously decreased.

CONCLUSION

Ele induces apoptosis of K562 cells, which is related with the down-regulation of bcl-2 protein in K562 cells.

Quercetin down-regulated bcl-2 gene expression in human leukemia HL-60 cells

AIM

To study the effect of quercetin (Que) on bcl-2 gene expression in human leukemia HL-60 cells.

METHODS

Immunohistochemical analysis and RNA Dot blot hybridization were used to identify the expression of bcl-2 genes.

RESULTS

The expression of bcl-2 protein was 94% in control HL-60 cells, which became 45%-84% when they were cultured with Que 15-60 mumol.L-1 for 48 h. The expression of bcl-2 mRNA in HL-60 cells was obviously decreased in treatment with Que 15-60 mumol.L-1.

CONCLUSION

The apoptotic action of Que in HL-60 cells was associated with the down-regulation of the apoptosis-suppressing gene bcl-2.

Effects of tanshinone II-A sulfonate on adhesion molecule expression of endothelial cells and platelets in vitro

AIM

To study the action of tanshinone II-A sulfonate (Tan) on adhesion molecule expression by cultured endothelial cells and platelets.

METHODS

Tumor necrosis factor alpha (TNF-alpha)-induced ICAM-1 expression on the cell surface and endothelial adhesivity toward HL-60 cells were studied using human umbilical vein endothelial cells (HUVEC). Thrombin-induced expression of platelet P-selectin was studied using human blood platelets. Adhesion molecule expression on the cell surface was measured by flow cytometry. The number of HL-60 cells adhering to the HUVEC monolayer was determined by liquid scintillation spectroscopy.

RESULTS

Pretreatment of HUVEC with TNF-alpha significantly enhanced ICAM-1 expression and increased HL-60 cells adhesion to HUVEC from 4.6% +/- 0.7% to 30% +/- 6%. Tan (25-200 mumol.L-1) inhibited the effects of TNF-alpha in a concentration-dependent manner. Tan also inhibited the increase of P-selectin expression of thrombin-activated platelets in a concentration-dependent manner.

CONCLUSION

Tan inhibited expression of adhesion molecules (ICAM-1, P-selectin) in HUVEC and in human blood platelets.

Involvement of interleukin-2 in analgesia produced by Coriolus versicolor polysaccharide peptides

AIM

To study the role of interleukin-2 (IL-2) and mediobasal hypothalamus (MBH) in analgesia produced by Coriolus versicolor polysaccharide peptide (PSP).

METHODS

The IL-2 antiserum was injected i.c.v. or i.p. and the MBH was destroyed electrolytically.

RESULTS

PSP i.g. 1 g.kg-1.d-1 for 6 d increased the pain threshold in tail stimulation-vocalization test in rats. This PSP-produced analgesia was blocked by i.c.v., but not i.p., IL-2 antiserum and disappeared after electrolytic lesion of MBH.

CONCLUSION

The analgesia produced by PSP is mediated by IL-2 which is activated by PSP and interacts with IL-2 receptors in the MBH.

Quercetin induced apoptosis in human leukemia HL-60 cells

AIM

To examine whether quercetin (Que) might induce apoptosis in human leukemia HL-60 cells.

METHODS

DNA fragmentation was visualized by agarose gel electrophoresis. Inhibition of proliferation was measured with a colorimetric MTT-assay. The DNA degradation was determined using flow cytometry, and the microscopic changes were observed by an electron microscope.

RESULTS

Que 15-120 mumol.L-1 elicited typical apoptosis morphological changes including condensed chromatin, nuclear fragmentation, and reduction in volume. DNA fragmentation and DNA degradation in a concentration-dependent manner in HL-60 cells. Que inhibited HL-60 cell proliferation. The values of IC50 and 95% confidence limits were 43 (30-61) mumol.L-1 after 48-h treatment with Que.

CONCLUSION

Que induced apoptosis in HL-60 cells.

Bulked segregant analysis using microsatellites: mapping of the dominant white locus in the chicken

In order to perform a linkage study, the genotypes of a large number of individuals from a segregating population need to be determined. In case the phenotype to be mapped is influenced by a single locus or a major gene, sampling of the DNA from individual animals with the same phenotype into a single pool (bulked segregant) can reduce the number of typings. In this study we used bulked segregant analysis in order to map the Dominant White locus in the chicken. In a pilot experiment, we showed that allele frequencies can be accurately estimated from pooled samples using fluorescently labeled microsatellite markers. A segregating population for the Dominant White locus was obtained by performing a cross between a white male chicken (Genotype li for Dominant White) and a black female chicken (ii). The resulting progeny of 21 white and 18 black chickens were divided in two pools. Genotypes for both the parents and the pools were determined using 168 fluorescently labeled microsatellite markers, of which 68 were informative. The relative allele frequencies between the pools were estimated for these 68 informative markers. One marker (MCW188) was found to segregate with the Dominant White locus. Subsequent typing of all individuals from this cross and an additional 148 animals from five different families showed only two recombinants between the marker and the Dominant White locus, resulting in a LODlinkage score (log10 of odds) of 36. Using the pooled DNA approach, the Dominant White locus was successfully mapped on linkage group 22 of the East Lansing reference family at a distance of 2 cM from MCW188.

Effects of quercetin on production and release of endothelin and cGMP from cultured endothelial cells

AIM

To evaluate the effects of quercetin (Que) on the formation and release of endothelin (ET) and cyclic guanosine monophosphate (cGMP) by endothelial cells.

METHODS

Radioimmunoassay (RIA) was used to assess the amounts of ET and cGMP produced by unstimulated human umbilical vein cells (HUVEC) or HUVEC stimulated with activated platelets and thrombin.

RESULTS

Following the treatment of the cultured HUVEC with activated platelets, the amount of ET in the medium was increased, but no significant effect on cGMP within the cells was seen. Thrombin not only increased the amount of ET in the medium, but also raised the level of cGMP within the cells. Pretreatment of HUVEC with Que 0.5, 5, and 50 mumol.L-1, the release of ET by HUVEC stimulated with thrombin and thrombin-activated platelets was much inhibited. Que 0.5-50 mumol.L-1 markedly increased the amount of cGMP in HUVEC stimulated with thrombin and activated platelets. Que also inhibited the release of ET from unstimulated HUVEC, but increased the production of cGMP from unstimulated EC.

CONCLUSION

Thrombin and activated platelets stimulated the release of ET from HUVEC and Que inhibited the release of ET and promoted the formation of cGMP from HUVEC.

Effect of quercetin on platelet aggregation induced by oxyradicals

AIM

To study the action of quercetin (Que) on inhibiting platelet aggregation.

METHODS

Active oxygen free radicals produced by xanthine/xanthine oxidase (Xan/XO) reaction was used, platelet aggregation was determined by the turbidimetric method, and the Xan/XO oxyradicals generating reaction by luminol-dependent chemiluminescence (Che) method.

RESULTS

Active oxygen free radicals enhanced the platelet aggregation induced by ADP 1.6 mumol.L-1. The rate of maximal aggregation increased from 29%-38% for ADP to 59%-70% for ADP + Xan/XO. The enhancement was abolished by the treatment of platelet-rich plasma (PRP) with Que 650 mumol.L-1 or hydrocortisone (Hyd) 900 mg.L-1. Both Que and Hyd scavenged the active oxyradicals in vitro. The Che was decreased by 75.7% (Que 4 mumol.L-1) and 79.0% (Hyd 900 mg.L-1) as compared with control.

CONCLUSION

Active oxygen free radicals participated in the platelet aggregation, and scavenging oxyradicals by Que was one of mechanisms of inhibiting platelet aggregation.

Effects of Coriolus versicolor polysaccharides peptides on electric activity of mediobasal hypothalamus and on immune function in rats

AIM

The nervous mechanism of the immune potentiating effect of Coriolus versicolor polysaccharides peptides (PSP) was studied in Wistar rats.

METHODS

The unit discharge of the mediobasal hypothalamus (MBH) neurons was recorded extracellularly and the lymphocyte proliferation was measured.

RESULTS

PSP 1 g.kg-1 ig for 5 d increased the T-lymphocytes and promoted T-lymphocyte proliferation in spleen and peripheral blood. This promoting effect of PSP was blocked by MBH lesion. PSP increased the discharge frequency of MBH neurons, but no increase in discharge frequency was observed after treatment of PSP plus immune inhibitor, cyclosporin A.

CONCLUSION

MBH is involved in the immune-potentiating effect of PSP.

Effects of quercetin on aggregation and intracellular free calcium of platelets

AIM

To study the effects of Que on the intraplatelet free calcium concentration and the effects of calcium on the inhibition of platelet aggregation by Que.

METHODS

Using Quin-2 fluorescence technique.

RESULTS

Que inhibited the platelet aggregation and the rise of [Ca2+]i induced by thrombin in platelets. The values of IC50 and 95% confidence interval were 146.2 (92.4 - 231.3) and 78.5 (49.5 - 124.4) mumol.L-1, respectively. The inhibitory effects of Que on platelet aggregation induced by thrombin were reduced by adding calcium to the medium, and Que had no effect on thrombin-induced internal Ca2+ release from dense tubular system.

CONCLUSION

The inhibitory effects of Que on aggregation and the rise of [Ca2+]i in platelets was mainly due to an inhibition of Ca2+ influx.

Modulation of bradykinin-induced intracellular Ca2+ oscillations in v-Ki-ras-transformed fibroblasts

Modulation of bradykinin (BK)-induced intracellular Ca2+ oscillations was investigated with single cell Ca2+ analysis in v-Ki-ras-transformed NIH3T3 fibroblasts. The Ca2+ oscillations were inhibited by the addition of a specific antagonist for subtype 2 of BK receptors (B2 receptor), not the antagonist for B1 receptor. Decrease of the extracellular Ca2+ concentration suppressed the [Ca2+]i oscillations and application of thapsigargin dissipated the [Ca2+]i oscillations. These findings suggest that the continuous activation of B2 receptor leading to the fluctuations of both Ca2+ influx which refills the internal Ca2+ stores, and Ca2+ mobilization from the internal stores, is essential to the occurrence of the [Ca2+]i oscillations in these cells.

Effects of quercetin on Na(+)-K(+)-exchanging ATPase and Ca(2+) Mg(2+)-ATPase in rats

Quercetin (Que) ig 200 mg.kg-1, qd x 14 d decreased activities of the Na(+)-K(+)-exchanging ATPase (I) of rat brain plasma membranes and heart sarcolemmal and Ca(2+) Mg(2+)-ATPase (II) of heart sarcolemmal membrane. Que 100 mg.kg-1 reduced the activity of I from rat heart sarcolemmal preparation, but had no effect on that from rat brain plasma membranes. The result shows that I of myocardium is more sensitive than that of brain in rat. Que also showed a remarkable inhibitory effect in the II of heart sarcolemma.

Effects of quercetin on platelet and reperfusion-induced arrhythmias in rats

The role of platelets in reperfusion arrhythmias (RA) and the efficacy of quercetin (Que) in preventing the arrhythmias were investigated in anesthetized rats. Platelet count (PC) was performed, the ultrastructure of platelets was scrutinized, and the levels of thromboxane B2 (TXB2) and 6-keto-prostaglandin F1 alpha (Keto-PGF1 alpha) in plasma were determined by radioimmunoassay (RIA). The pretreatment with Que (5 mg.kg-1) 2 min prior to reperfusion inhibited RA. Que remarkably improved the ultrastructural deviation of platelet, inhibited the platelet aggregation and thromboxane A2 (TXA2) formation, and increased the prostacyclin (PGI2) generation and the ratio of PGI2/TXA2. The decrease in PC and increase in TXB2 level in plasma indicated the participation of platelets in the arrhythmogenic activity of ischemia and reperfusion. The results showed that Que produced a protective effect against RA probably through inhibiting the platelet aggregation, TXA2 formation and increasing the PGI2 generation.

[Effect of quercetin on chemiluminescence of human platelets induced by arachidonic acid]

Arachidonic acid (AA)-induced platelet chemiluminescence (CL) was measured with a lumiphotometer. Quercetin remarkably inhibited the CL, the IC50 of quercetin was 3 mumol.L-1. When quercetin plus aspirin, which inhibits only cyclooxygenase, was added, the inhibitory rate of platelet-CL obviously increased (P < 0.01). On the other hand, the quercetin had a scavenging effect on superoxide anion radical using alkaline sodium dithionite solution generation. The IC50 was 20.9 mumol.L-1. In addition, superoxide dismutase of 0.1 mg.ml-1 inhibited the platelet-CL by 97.8%, while mannitol, a hydroxyl radical scavenger, only by 43.3% at a concentration of 80 mg.ml-1. These results suggest that the mechanism of the inhibiting AA-induced platelet-CL by quercetin was associated with scavenging the superoxide anion radical directly and with inhibiting the cyclooxygenase.

[Effects of piracetam on Na(+)-K(+)-ATPase and monoamine oxidase in rat brain and its antioxidation effect]

Piracetam, ig 600 mg.kg-1.d-1 for 30 d, caused a 20% decrease in the activity of Na(+)-K(+)-ATPase and monoamine oxidase (MAO) in vivo. In vitro, it presented an inhibitory effect on MAO, but had no direct effect on Na(+)-K(+)-ATPase at a concentration of 100 mmol.L-1. Piracetam had a potential action in scavenging free radicals. This action may be related to its clinical effects on amnesia and Alzheimer's disease.