Effect of myofiber characteristics and thickness of perimysium and endomysium on meat tenderness of chickens

The objective of the present study was to evaluate the role of myofiber characteristics and the thickness of 2 major muscle membranes, perimysium and endomysium, in determining the breast meat tenderness of chickens. Birds from 2 breeds (White Leghorn and a line of broiler) were chosen. Chicks were sexed and wing-banded at hatch and were grown in separate cages in a single house. Sixty broilers and 60 White Leghorns were harvested at 6 wk of age, respectively, whereas another 60 White Leghorns were slaughtered at 18 wk of age. An equal number of males and females was maintained for each group. Body weight, breast muscle weight, pH, drip loss, cooking loss, Warner-Bratzler shear force value (SFV), total energy of shear force, fiber diameter, sarcomere length, myofiber density, and the thickness of endomysium and perimysium of the breast were determined for each bird. At 6 wk of age, histological examination indicated that the size of myofiber and thickness of endomysium and perimysium of broilers were larger than that those of White Leghorns (P < 0.01), whereas the SFV, drip loss, and cooking loss of broilers were smaller (P < 0.01). A comparison between the White Leghorns at 18 wk and the broilers at 6 wk, which were at similar BW but different ages, showed that the breast muscle weight of broilers was larger (P < 0.01) than that of White Leghorns. For breast muscle, the endomysium of broilers at 6 wk was thicker than that of White Leghorns at 18 wk (P < 0.01), whereas the perimysium was thinner (P < 0.01). The SFV, drip loss, and the cooking loss of broilers were smaller than those of White Leghorns at similar BW (P < 0.01). Meat tenderness was negatively correlated with myofiber density (-0.27) and the thickness of endomysium (-0.29) and positively correlated with the thickness of perimysium (0.20). It is suggested that muscle membrane should be considered in evaluating meat tenderness of the chicken.

Neurogenesis in the R6/2 mouse model of Huntington's disease is impaired at the level of NeuroD1

Adult neurogenesis is impaired in the hippocampus of transgenic R6 mouse models of Huntington's disease (HD). The phenotypes of R6 transgenic mice mimic several symptoms and signs of the disease (Li et al., 2005). They exhibit neurological and endocrine changes resembling some symptoms seen in humans. The reduction in neurogenesis is only apparent in the dentate gyrus as the number of newborn neurons in the subventricular zone, and olfactory bulb, is normal in R6 mice. The mechanism(s) underlying the reduction in hippocampal neurogenesis is still not fully understood. Here we show that the number of neuroblasts, but not granule neuron progenitors, is greatly reduced in 11-week old transgenic mice compared with wild-type (WT) controls. We demonstrate that NeuroD1 expression is reduced in the hippocampus. This is coupled to a decreased expression of downstream markers doublecortin and calretinin in maturing neurons. Taken together, our results suggest that mutant huntingtin (Htt) causes alterations of proteins expression in hippocampal progenitors, which might contribute to cognitive deficits in Huntington's disease.

3D FEA of high-performance polyethylene fiber reinforced maxillary dentures

OBJECTIVE

This project studies the effect of high-performance polyethylene (HPPE) fibers on stress distributions in a maxillary denture and the influence of fiber position on improving denture performance.

METHODS

A denture was scanned with a 3D Advanced Topometric Sensor digitizing system. The measuring system converted the images into a 3D digital model. A 3D reverse engineering technology then produced a numerical model which was then refined with Rapidform software. The underlying mucosa and bone were constructed using a freeform system integrated with a PHANTOM haptic device. A fiber lamella reinforcement was incorporated into the denture at different positions (fitting side, mid-palatal plane, polished side) with SolidWorks software. Boundary conditions were constrained at the top of the basal bone while bite force of 230 N was applied to the posterior teeth on both sides. The denture models were analyzed with ABAQUS software.

RESULTS

Stress concentrations were found at the incisal notch and at the anterior and posterior palatal surfaces of the unreinforced denture. The incorporated reinforcement effectively reduced the stress concentrations at these surfaces. Placement of the fibers at polished side was the best position in reducing stress concentrations.

SIGNIFICANCE

3D FEM usefully provides a non-laboratory means to reveal the weak areas in the maxillary complete denture, and exhibit the effectiveness of HPPE reinforcement together with fiber positions on enhancement of denture strength.

New development of advanced superconducting electron cyclotron resonance ion source SECRAL (invited)

Superconducting electron cyclotron resonance ion source with advance design in Lanzhou (SECRAL) is an 18-28 GHz fully superconducting electron cyclotron resonance (ECR) ion source dedicated for highly charged heavy ion beam production. SECRAL, with an innovative superconducting magnet structure of solenoid-inside-sextupole and at lower frequency and lower rf power operation, may open a new way for developing compact and reliable high performance superconducting ECR ion source. One of the recent highlights achieved at SECRAL is that some new record beam currents for very high charge states were produced by 18 GHz or 18+14.5 GHz double frequency heating, such as 1 e microA of (129)Xe(43+), 22 e microA of (209)Bi(41+), and 1.5 e microA of (209)Bi(50+). To further enhance the performance of SECRAL, a 24 GHz/7 kW gyrotron microwave generator was installed and SECRAL was tested at 24 GHz. Some promising and exciting results at 24 GHz with new record highly charged ion beam intensities were produced, such as 455 e microA of (129)Xe(27+) and 152 e microA of (129)Xe(30+), although the commissioning time was limited within 3-4 weeks and rf power only 3-4 kW. Bremsstrahlung measurements at 24 GHz show that x-ray is much stronger with higher rf frequency, higher rf power. and higher minimum mirror magnetic field (minimum B). Preliminary emittance measurements indicate that SECRAL emittance at 24 GHz is slightly higher that at 18 GHz. SECRAL has been put into routine operation at 18 GHz for heavy ion research facility in Lanzhou (HIRFL) accelerator complex since May 2007. The total operation beam time from SECRAL for HIRFL accelerator has been more than 2000 h, and (129)Xe(27+), (78)Kr(19+), (209)Bi(31+), and (58)Ni(19+) beams were delivered. All of these new developments, the latest results, and long-term operation for the accelerator have again demonstrated that SECRAL is one of the best in the performance of ECR ion source for highly charged heavy ion beam production. Finally the future development of SECRAL will be presented.

Production of highly charged ion beams with SECRAL

Superconducting electron cyclotron resonance ion source with advanced design in Lanzhou (SECRAL) is an all-superconducting-magnet electron cyclotron resonance ion source (ECRIS) for the production of intense highly charged ion beams to meet the requirements of the Heavy Ion Research Facility in Lanzhou (HIRFL). To further enhance the performance of SECRAL, an aluminum chamber has been installed inside a 1.5 mm thick Ta liner used for the reduction of x-ray irradiation at the high voltage insulator. With double-frequency (18+14.5 GHz) heating and at maximum total microwave power of 2.0 kW, SECRAL has successfully produced quite a few very highly charged Xe ion beams, such as 10 e microA of Xe(37+), 1 e microA of Xe(43+), and 0.16 e microA of Ne-like Xe(44+). To further explore the capability of the SECRAL in the production of highly charged heavy metal ion beams, a first test run on bismuth has been carried out recently. The main goal is to produce an intense Bi(31+) beam for HIRFL accelerator and to have a feel how well the SECRAL can do in the production of very highly charged Bi beams. During the test, though at microwave power less than 3 kW, more than 150 e microA of Bi(31+), 22 e microA of Bi(41+), and 1.5 e microA of Bi(50+) have been produced. All of these results have again demonstrated the great capability of the SECRAL source. This article will present the detailed results and brief discussions to the production of highly charged ion beams with SECRAL.

Toll-like receptor 2 gene polymorphism and its relationship with SCS in dairy cattle

Toll-like receptor 2 (TLR2) plays an important role in the innate immune response to a variety of pathogens. In this study, bovine TLR2 gene was taken as a candidate gene for mastitis resistance. Through PCR-SSCP analysis and sequencing, three missense mutations at T385 G, G398A, and G1884A were detected in the coding region that encoded extracellular domain. Altogether 240 dairy cattle of three breeds (Holstein, Simmental, and Sanhe cattle) were genotyped and allele frequencies were determined. The effects of TLR2 polymorphisms on somatic cell score (SCS) were analyzed and significant association was found between T385 G and SCS. The mean of genotype GG was significantly lower than those of genotype TT and TG. No significant associations were found with SCS for G398A and G1884A. Information provided in this research will be useful in further studies to determine the role of TLR2 gene in the mastitis resistance.

Proteomic and bioinformatic analysis on endocrine organs of domesticated silkworm, Bombyx mori L. for a comprehensive understanding of their roles and relations

Three organs of silkworm larva endocrine system, including brain (Br), subesophageal ganglion (SG) and prothoracic glands (PG), were studied employing shotgun LC-MS/MS combined with bioinformatic analysis to comprehensively understand their roles and relations. Totally, 3430, 2683, and 3395 proteins were identified including 1885 common and 652, 253, and 790 organ-specific ones in Br, SG, and PG, respectively. Identified common-expressed proteins indicated the existence of intrinsic complex interactions among these parts of endocrine system. Most of the reputed organs-specific proteins were identified by this approach. KEGG pathway analysis showed 162 same pathways among the 169, 164, and 171 relating Br, SG, and PG. This analysis revealed functional similarities with exceptional resemblance in their metabolism and signaling pathways of the three organs. On the other hand, 70, 57, and 114 organ-specific enzymes related pathways were detected for Br, SG, and PG confirming their functional differences. These results reveal a cooperative mechanism among the three endocrine organs in regulating various physiological and developmental events, and also suggest that the organ-specific proteins might be the fundamental factors responsible for the functional differentiation of these organs.

Ischemic hepatitis

Ischemic hepatitis, otherwise known as "shock liver" and "hypoxic hepatitis", usually is secondary to a clinical setting of severe heart failure or shock. The main clinical manifestations are shown as the symptoms of primary diseases such as cardiac failure or shock, and gastrointestinal symptoms similar to viral hepatitis. Laboratory tests show an acute elevation in serum aminotransferase level, 25-250 times as high as the upper limit of normal (ULN) during a 12-48 hour period, which is rapidly recovered in about 7-14 days after treatment. Secondary to circulatory failure, there is a high rate of renal dysfunction in ischemic hepatitis. Treatment and prognosis depend on the protopathy.

Physical and Electrical Performance of Vapor-Solid Grown ZnO Straight Nanowires

Physical and electrical properties of wurtzitic ZnO straight nanowires grown via a vapor-solid mechanism were investigated. Raman spectrum shows four first-order phonon frequencies and a second-order Raman frequency of the ZnO nanowires. Electrical and photoconductive performance of individual ZnO straight nanowire devices was studied. The results indicate that the nanowires reported here are n-type semi-conductors and UV light sensitive, and a desirable candidate for fabricating UV light nanosensors and other applications.

Stronger in vitro phagocytosis by monocytes-macrophages is indicative of greater pathogen clearance and antibody levels in vivo

Monocytes-macrophages are crucial players in specific and nonspecific immune responses to protect organisms from invasion of bacteria or viruses. In this study, monocytes in circulation from 2 lines of Silky and Starbro chickens with different disease resistance were separated and cultured in vitro. After identification with acridine orange (AO), Giemsa staining, and CD14 immunostaining, monocytes-macrophages were used for adherence and phagocytosis test. The overall percentages of adherence of Silky monocytes was 1.5 times greater than that of Starbro (P < 0.01), which were 26.85% +/- 8.24% and 18.34% +/- 8.15%, respectively (mean +/- SD). The monocytes-macrophages phagocytic index, phagocytic product, and percentage of phagocytosis in Silkies were greater than in Star-bros, respectively. The difference of phagocytic index was significant (P < 0.05), that is, 3.70 +/- 1.75 and 1.97 +/- 0.31, respectively (mean +/- SD). Then, 20 Silkies were divided into 2 groups according to phagocytic index: high phagocytic index (HPI) group and low phagocytic index (LPI) group, to study the relationship between phagocytic activity in vitro and pathogen clearance. After being challenged against Salmonella Pullorum C79-13, the Silky birds with HPI produced a 3-fold greater level of specific antibodies compared with those with LPI (P < 0.01), 50.21 +/- 6.67 and 16.85 +/- 4.52, respectively (mean +/- SD). In contrast to LPI birds, HPI birds shed less Salmonella Pullorum bacteria (P < 0.05), that is, 168.98 x 10(8) +/- 294.74 x 10(8) compared to 385.40 x 10(8) +/- 399.94 x 10(8) (mean +/- SD), and the shedding peak of Salmonella Pullorum in the test span appeared 4 d earlier. These results indicated that phagocytosis of monocytes-macrophages had strong effects on antibody titer and bacteria shedding postchallenge, which could be used to predict the disease resistance in animals.

Temporal and spatial expression of TGF-beta2 in tooth crown development in mouse first lower molar

Transforming Growth Factor beta2 (TGF-beta2) is involved in the regulation of many important cellular processes during tooth development. In this study we systematically characterized the expression pattern of TGF-beta2 in vivo and further analyzed its possible roles during different developmental stages of mouse first lower molar using immunofluorescence histochemical method with confocal microscopy. TGF-beta2 signaling was detected in different developing stages in both dental epithelium and surrounding dental mesenchyme. For the first time, we found that the basement membrane and epithelial cells in the basal layer showed no immunostaining from embryonic day 11 to 13; the primary enamel knot and secondary enamel knot exhibited pronounced immunostaining with different expression patterns at embryonic day 14 and 16. In addition, the mature ameloblast lost immunoreactivity, but the secretory ameloblast still exhibited positive immunoreaction at day 2 of postnatal development. Collectively, the temporospatial distribution patterns of TGF- beta2, especially in the basement membrane, epithelial cells in the basal layer, enamel knot, mature odontoblast and ameloblast, suggested a close association between TGF-beta2 signaling and tooth crown development, and indicated that TGF-beta2 might participate in tooth initiation, epithelial morphogenesis, formation of dentine matrix, and ameloblast differentiation.

Somatostatin elevates topoisomerase II alpha and enhances the cytotoxic effect of doxorubicin on gallbladder cancer cells

BACKGROUND

Gallbladder cancer is a common and lethal digestive malignancy which is nonsensitive to routine chemotherapy. Doxorubicin (DOX) is one of the major chemotherapeutic drugs for patients with gallbladder cancer. We tried to evaluate if combined use of somatostatin (SST) and DOX could have synergistic effect in the treatment of gallbladder cancer.

METHODS

Cells from the human gallbladder cancer cell line GBC-SD were treated with SST. Cell cycle analysis was determined by flow cytometry. Western blot analysis was performed to determine the protein levels of topoisomerase IIalpha (Topo IIalpha) after SST treatment. RT-PCR was utilized to detect SST receptors in GBC-SD cells. Finally, the chemotherapeutic effect of DOX combined with SST treatment on cellular growth was measured by MTT assay.

RESULTS

SST could induce cell cycle arrest in S phase and upregulate Topo IIalpha expression in GBC-SD cells. GBC-SD cells expressed all 5 subtypes of SST receptors. Finally, combined use of DOX with SST had a synergistic cytotoxic effect on GBC-SD cells.

CONCLUSION

SST, a naturally occurring, nontoxic compound, may represent a novel adjuvant chemotherapeutic agent for patients with gallbladder cancer.

Evaluation of IgG-ELISA for the diagnosis of Schistosoma japonicum in a high prevalence, low intensity endemic area of China

Antibody-based diagnostic methods for detecting infection with Schistosoma japonicum have been developed and integrated into the national control program in China; however, the utility of these methods compared with conventional coprological methods remains unclear. In two consecutive years, we compared the performance characteristics of Kato-Katz with a commercially available enzyme-linked immunosorbent assay (ELISA) that detects anti-egg antigen IgG antibodies in a high prevalence, low intensity village in China (1025 subjects in 2005 and 652 subjects in 2006). In comparison with Kato-Katz based on duplicate stool specimens, each read in triplicate, the sensitivity of IgG-ELISA was high, ranging from 79.3% to 87.4% but with a relatively low specificity of 38.9% to 53.5%. The positive predictive value ranged from 20.8% to 24.6% while the negative predictive value ranged from 93.1% to 94.4%. When analyzed as continuous variables, there was a poor correlation between EPG (eggs per gram feces) and antibody level in both years (r(2005)=0.23 and r(2006)=0.41). We detected a trend toward reduced sensitivity at lower infection intensity as measured by Kato-Katz in 2005 (P=0.262) and 2006 (P=0.287). We evaluated changes in antibody levels and the prevalence of positive antibody in the cohort of subjects examined in both 2005 and 2006 (n=565). The prevalence of positive antibody but not the continuous antibody level, decreased in individuals who were uninfected at both time points or who transitioned from infected to uninfected as assessed by Kato-Katz. In this cohort, the distribution of antibody levels measured in 2006 among individuals who were positive by Kato-Katz in 2006 broadly overlapped with the distribution of antibody levels in individuals who were negative by Kato-Katz in both 2005 and 2006. Our results indicate fairly poor performance characteristics of the anti-egg antigen IgG-ELISA for the detection of active infection with S. japonicum in our community based sample and are in contrast with other reports based on more selected populations. The high prevalence but low intensity of S. japonicum in our study community reflects the evolving epidemiology of schistosomiasis in communities receiving intermittent treatment with praziquantel in China. We suggest marked caution in implementing anti-egg antigen IgG-ELISA based diagnosis for either individual level diagnosis or population-based targeting for national control programs.

[Effects of sodium butyrate on proliferation and differentiation of human gastric carcinoma cell line AGS]

BACKGROUND & OBJECTIVE

Sodium butyrate (NaBT) can inhibit proliferation and induce differentiation of various tumor cells. This study was to investigate effects of NaBT on the proliferation and differentiation of human gastric carcinoma cell line AGS and explore the possible mechanism.

METHODS

AGS cells were treated with 0, 1.0, 2.0 and 4.0 mmol/L of NaBT. Cell proliferation was detected by MTT assay; cell morphology changes were observed under optical and transmission electron microscopy; cell cycle was detected by flow cytometry (FCM). The expression of cyclin-dependent kinase inhibitor p21 was detected by reverse transcription-polymerase chain reaction (RT-PCR) and Western blot.

RESULTS

After incubation with different concentrations of NaBT for 24 to 72 h, AGS cell proliferation was inhibited dramatically and the highest inhibition rate was 81.54%. The structure of AGS cells changed greatly. NaBT induced an increase of G0/G1 phase cells and a significant decrease of S phase cells accompanied by the changes in DNA ploidy. The expression of p21 was up-regulated at both mRNA and protein levels. NaBT exerted its effects in a dose-dependent manner.

CONCLUSIONS

NaBT could induce G1 arrest and inhibit cell proliferation in AGS cells by up-regulating the expression of p21. This could reverse the malignant phenotype of AGS to some extents.

Cloning and identification of a novel sperm binding protein, HEL-75, with antibacterial activity and expressed in the human epididymis

BACKGROUND

The HEL-75 protein is a beta-defensin that was identified by analyzing a human epididymis cDNA library. Studying its function may not only elucidate the mechanisms of host defense, but may also provide new alternatives for novel therapeutic drugs for reproductive tract infections.

METHODS

The HEL-75 gene was amplified by PCR, and its structure and function were predicted and analyzed with bioinformatics tools. Polyclonal serum was raised against recombinant HEL (rHEL)-75 protein. The gene expression pattern was analyzed with RT-PCR and immunofluorescent staining. Finally, the antimicrobial activity and function during fertilization of HEL-75 were analyzed using a colony-forming unit assay and IVF, respectively.

RESULTS

The human HEL-75 gene is located on chromosome 20p13 and encodes a 95 amino acid protein with a predicted N-terminal signal peptide of 22 amino acids. The protein has six conserved cysteine residues, characteristic of members of the beta-defensin superfamily, as well as several potential post-translational modification sites. At the transcriptional level, HEL-75 was expressed in the epididymis and lung, but only in the epididymis at the translational level. Immunofluorescent staining showed that HEL-75 protein bound spermatozoa in the epididymis. RHEL-75 protein could kill Escherichia coli in vitro in a dose- and time-dependent fashion. However, no effect was observed on sperm motility nor fertilization when spermatozoa were blocked with anti-rHEL-75 polyclonal serum.

CONCLUSION

HEL-75 is a new beta-defensin expressed in the epididymis and on sperm; it may play an important role in host defense.

Colorectal cancer or colon and rectal cancer? Clinicopathological comparison between colonic and rectal carcinomas

AIMS

The aim of this study was to compare features of colon and rectal cancers such as prognosis, clinicopathological features and tumor markers, namely carcinoembryonic antigen (CEA), matrix metalloproteinase (MMP)-2 and p27(kip1).

METHODS

Two hundred and thirty patients with stage I-III colon or rectal cancer were retrospectively assessed with the endpoint of recurrence or metastasis after curative operation. CEA, MMP-2 and p27(kip1) were studied by immunohistochemistry in cancer tissues of all patients.

RESULTS

The disease-free 3-year survival rate after operation of the total 230 patients was 63.0%. The prognosis of colon cancer was significantly better than that of rectal cancer (70.6 vs. 57.0%; p = 0.017), especially for stage III (p = 0.0059). Multivariate analysis also demonstrated that tumor location in the colon or rectum, differentiation, venous invasion and the expression of CEA were independent factors for prognosis. The hazard of recurrence and metastasis in rectal cancer was 1.564 times that in colon cancer. In both groups, there were no statistical differences in age, gender, tumor size, tumor gross type, mucin production, tumor differentiation, venous invasion, MMP-2 and p27(kip1).

CONCLUSION

We investigated prognosis, clinicopathological factors, oncogenes and tumor suppressor gene production in colon and rectal cancers. The prognosis of colon cancer is better than that of rectal cancer, especially for stage III. This study shows some differences between colon and rectal cancer.

[Regional difference of land use/cover change in farming-pasturing zone of Naiman Banner in Inner Mongolia]

Based on the four TM images of Naiman Banner in Inner Mongolia in 1975, 1985, 1995 and 2005, the extent and relative rate of land use change were used as the indices to analyze the regional difference of land use/cover change in the farming-pasturing zone of Naiman Banner, and the indices abundance and importance value were adopted to analyze the spatial distribution features of land use/cover change in the study area. The results showed that from 1975 to 2005, the types of land use/cover became diversified. The annual change rate was high, and the regional difference was significant. In the northern alluvial plain sub-area, woodland area increased rapidly and largely, while sandy land area decreased obviously. The changing speed of the areas of meadow and sandy land was the fastest, while that of residential area was the slowest. The main forms of land conversion were the conversion from sandy land to cropland and woodland. In the middle sandy land sub-area, sandy land had a wide distribution. The changes of other land use types were comparatively small, and the main form of land conversion was the inter-conversion between cropland and sandy land. In southern loess sub-area, cropland was the dominant land use type and had the smallest change, meadow and sandy land changed most quickly, and the conversion from meadow to cropland and woodland was the most important land conversion form. Natural factors determined the principal characteristics of land use structure in each sub-area of the study area, and artificial factors determined the changing trends of each land use type in each sub-area.

12-lipoxygenase induces apoptosis of human gastric cancer AGS cells via the ERK1/2 signal pathway

12-Lipoxygenase (12-LOX) is over-expressed in a variety of human tumors, but its exact effect on the tumorogenesis of gastric cancer remains largely obscure. To investigate the effect of 12-LOX and its inhibitor baicalein on proliferation and apoptosis of human gastric cancer, AGS cells were separately treated with 12-hydroxyeicosatetraenoic acid (12-HETE, a metabolite of 12-LOX) and baicalein. MTT assay revealed that the absorbance of the 12-HETE-treated group was significantly (P < 0.01) higher than that of control group and that the absorbance of baicalein-treated group was significantly (P < 0.01) less than that of the control group, and that 48 h after treatment the apoptosis index of the baicalein-treated group was significantly (P < 0.01) higher than that of the untreated group and was significantly (P < 0.01) lower in the 12-HETE-treated group. Western blotting analysis was used to investigate the mechanism of these effects. The results revealed that the concentration of phosphorylated ERK in cells treated with 100 nmol L(-1) 12-HETE was significantly (P < 0.05) higher than in the untreated group and that the concentration of phosphorylated ERK1/2 in cells treated with 40 micromol L(-1) baicalein was significantly (P < 0.05) lower than in the untreated group. The expression level of bcl-2 was up-regulated and down-regulated after separate treatment with 12-HETE and baicalein, respectively, and both of these effects could be blocked by PD98059. Protein kinase C (PKC) activity was increased by treatment with 12-HETE and reduced by treatment with baicalein (P < 0.05). The PKC inhibitor BIM (bisindolymaleimide-I) blocked the phosphorylation of ERK1/2 and activation of PKC induced by 12-LOX. When pretreated with BIM, the concentration of phospho-ERK1/2 or bcl-2 in the BIM + 12-HETE-treated group was significantly (P < 0.05) lower than in that treated with 12-HETE only, and the concentration in the BIM + baicalein-treated group was significantly (P < 0.05) higher than in that treated with baicalein only. On the basis of these data we conclude that, via its metabolite 12-HETE, 12-LOX abolishes proliferation of AGS cells and protect cells from apoptosis by activating the ERK1/2 pathway and, eventually, enhances expression of bcl-2. Because PKC is also involved in the activation of ERK1/2 induced by 12-LOX, 12-LOX inhibitors would be potentially powerful anticancer agents for prevention and cure of human gastric cancer.

Activity of Nidus Vespae extract and chemical fractions against Streptococcus mutans biofilms

AIMS

To evaluate the effect of Nidus Vespae extract and chemical fractions on the viability and architecture of Streptococcus mutans biofilms.

METHODS AND RESULTS

The raw material was first extracted using 95% ethanol/water. Subsequent fractions were prepared from this extract using cyclohexane/ethyl acetate, petroleum ether/ethyl acetate and chloroform/methanol. The biomass dry weight and total protein of samples treated with Nidus Vespae extract and chemical fractions were significantly less than those treated with the vehicle control (P < 0.05). Biofilms treated with Nidus Vespae also resulted in lower percentage of polysaccharide composition. The pH decrease in the biofilm matrix was retarded by Nidus Vespae compared with the vehicle control. Architecture of biofilms treated with Nidus Vespae was different than in the vehicle control and 0.05% chlorhexidine.

CONCLUSIONS

Chloroform/methanol fraction was the most effective treatment.

SIGNIFICANCE AND IMPACT OF THE STUDY

The significant antibiofilm activity demonstrated by Nidus Vespae shows it to be a promising source of novel anticariogenic agents.

A Comparison of Mitochondrial Respiratory Function of Tibet Chicken and Silky Chicken Embryonic Brain

The Tibet chicken lives in high altitude and has adapted itself well to hypoxia. The Silky chicken is a lowland chicken from Jiangxi province of China. The objective of the present study was to investigate whether there were any differences in brain mitochondrial respiratory function between Tibet chicken and Silky chicken embryos incubated in a normoxic (21% oxygen concentration) or simulated hypoxic (13% O(2)) hatchibator. Brain mitochondria of chicken embryos were prepared by differential centrifugation on d 16 of incubation. The respiratory control ratio (RCR) and the adenosine 5'-diphosphate: oxygen ratio (ADP/O) were determined polarographically. The complex I activity was measured with an ultraviolet spectrophotometer by following the oxidation of the reduced state of beta-nicotinamide adenine dinucleotide. Under the normoxic incubation condition, there were no significant differences in the RCR, the ADP/O, and the activity of complex I between embryonic brain mitochondria of the 2 breeds. Under the hypoxic incubation condition, the ADP/O in brain mitochondria of embryos from the 2 breeds were identical. Also under hypoxic conditions the RCR in brain mitochondria of Tibet chicken embryos was higher (P < 0.05) than in Silky chicken embryos when brain mitochondria were provided with glutamate-malate, but no significant difference was found in the RCR with succinate as an energy substrate. The complex I activity of Silky chicken embryos was higher than that of Tibet chicken embryos when they were incubated in the hypoxic hatchibator (P < 0.01). In conclusion, the results show that under simulated hypoxic incubation conditions electron transport in brain mitochondria of Tibet chicken embryos was more tightly coupled than that of lowland chicken (Silky chicken) embryos with glutamate-malate as energy substrate, which was associated with the difference in the activity of complex I between embryonic brains of the 2 breeds. This work will provide reference for future studies on the association of mitochondrial respiratory function with the adaptation to hypoxia.

Biological Control of Grape Crown Gall by Rahnella aquatilis HX2

Crown gall induced by Agrobacterium vitis is a worldwide plant disease in grape-growing regions. Rahnella aquatilis HX2, a new isolate from vineyard soil in Beijing, showed a significant inhibition effect on the development of crown galls in grapevines. In field trials, immersion of the basal ends of grape cuttings with HX2 cell suspension inhibited or completely prevented crown gall formation caused by A. vitis K308 in the roots of the plants from the cuttings. The 3-year average disease incidence in grape plants treated with HX2 was 30.8% compared to 93.5% in plants without HX2. The culture supernatant of HX2 exhibited a stronger inhibition effect on disease development than did the cell suspension. HX2 could be found in the grape rhizosphere, grown under field conditions, for up to 90 days after inoculation. There was no significant difference in the mean population sizes of root microflora between plants treated and not treated with HX2. The inhibition effect of HX2 on crown gall in sunflower, caused by different agrobacterial strains, varied between 30.7 and 100%, depending on strains. Our results showed that Rahnella aquatilis HX2 may be used as a biological control agent for crown gall disease of grapes.