Host selection by thrips is affected by the floral volatile profile of sunflower.

Thrips, Frankliniella intonsa, is a highly polyphagous pest with a worldwide distribution. F. intonsa-infested sunflower seeds show marked visual damage. The study findings revealed that significantly more F. intonsa infested confection sunflower compared to oilseed sunflower, via olfactometer bioassay studies, we found that compared with the flower and pollen of oilseed sunflowers, those of confection sunflowers attract F. intonsa. Considering this discrepancy in the preference of F. intonsa on oilseed and confection sunflowers, the volatiles of the flower and pollens of two sunflowers were analysed by gas chromatography-mass spectroscopy. The behavioural responses of F. intonsa were assessed for these compounds using Y-tube bioassays. Geranyl bromide, a unique volatile component of oilseed sunflowers, induced an assertive approach-avoidance behaviour in F. intonsa, whereas the unique component ethyl isovalerate in confection sunflowers attracted F. intonsa. F. intonsa adults demonstrated significant attraction to the blends of confection sunflowers. Furthermore, field verification revealed that intercropping confection and oilseed sunflowers could effectively control F. intonsa. The study provided insights into the chemical cues used by F. intonsa in locating hosts. Therefore, oilseed sunflowers can be used as repellent plants to prevent F. intonsa invasion.

Remote terahertz wireless power transfer with self-resonating spoof plasmonic structures.

In this paper, we use a pair of self-resonating subwavelength spoof plasmonic structures to achieve remote non-radiative terahertz wireless power transfer, while nearly without affecting the electromagnetic environment of free space around the structure. The resonating frequency and quality factor of the magnetic dipole mode supported by the spoof plasmonic structures can be freely tuned by tailoring the geometric structure. By putting the weak source and detector into the self-resonating structures, we can find that the effective non-radiative terahertz power transferring distance can reach several hundred times the radius of the structures. Finally, we also demonstrate the efficient wireless power transfer capability for the multi-target receiving system. These results may provide a novel approach to the design of non-radiative terahertz wireless power transfer and communications.

A new insight on copper: Promotion of collagen synthesis and myofiber growth and development in juvenile grass carp (Ctenopharyngodon idella).

Copper (Cu) is a trace element, essential for fish growth. In the current study, in addition to growth performance, we first explored the effects of Cu on collagen synthesis and myofiber growth and development in juvenile grass carp (Ctenopharyngodon idella). A total of 1080 fish (11.16 ± 0.01 g) were randomly divided into 6 treatments (3 replicates per treatment) to receive five doses of organic Cu, which were Cu citrate (CuCit) at 0.99 (basal diet), 2.19, 4.06, 6.15, and 8.07 mg/kg, and one dose of inorganic Cu (CuSO4·5H2O at 3.15 mg/kg), for 9 weeks. The results showed appropriate Cu level (4.06 mg/kg) enhanced growth performance, improved nutritional Cu status, and downregulated Cu-transporting ATPase 1 mRNA levels in the hepatopancreas, intestine, and muscle of juvenile grass carp. Meanwhile, collagen content in fish muscle was increased after Cu intake, which was probably due to the following pathways: (1) activating CTGF/TGF-ß1/Smads signaling pathway to regulate collagen transcription; (2) upregulating of La ribonucleoprotein domain family 6 (LARP6) mRNA levels to regulate translation initiation; (3) increasing proline hydroxylase, lysine hydroxylase, and lysine oxidase activities to regulate posttranslational modifications. In addition, optimal Cu group increased myofiber diameters and the frequency of myofibers with diameter >50 µm, which might be associated with upregulation of cyclin B, cyclin D, cyclin E, proliferating cell nuclear antigen, myogenic determining factor (MyoD), myogenic factor 5, myogenin (MyoG), myogenic regulatory factor 4 and myosin heavy chain (MyHC) and downregulation of myostatin mRNA levels, increasing protein levels of MyoD, MyoG and MyHC in fish muscle. Finally, based on percentage weight gain (PWG), serum ceruloplasmin (Cp) activity and collagen content in fish muscle, Cu requirements were determined as 4.74, 4.37 and 4.62 mg/kg diet (CuCit as Cu source) of juvenile grass carp, respectively. Based on PWG and Cp activity, compared to CuSO4·5H2O, the efficacy of CuCit were 131.80% and 115.38%, respectively. Our findings provide new insights into Cu supplementation to promote muscle growth in fish, and help improve the overall productivity of aquaculture.

Prognostic effect of excessive chemotherapy cycles for stage II and III gastric cancer patients after D2 + gastrectomy.

BACKGROUND: According to relevant investigation and analysis, there are few research studies on the effect of excessive chemotherapy cycles after D2 gastrectomy on the survival of patients with gastric cancer. AIM: To determine whether excessive chemotherapy cycles provide extra survival benefits, reduce recurrence rate, and improve survival rate in patients with stage II or III gastric cancer. METHODS: We analyzed and summarized 412 patients with stage II gastric cancer and 902 patients with stage III gastric cancer who received D2 gastrectomy plus adjuvant chemotherapy or neoadjuvant chemotherapy. Analysis and comparison at a ratio of 1:1 is aimed at reducing realistic baseline differences (n = 97 in each group of stage II, n = 242 in each group of stage III). Progression-free survival, overall survival and recurrence were the main outcome indicators. RESULTS: When the propensity score was matched, the baseline features of stage II and III gastric cancer patients were similar between the two groups. After a series of investigations, Kaplan-Meier found that the progression-free survival and overall survival of stage II and III gastric cancer patients were consistent between the two groups. The local metastasis rate (P = 0.002), total recurrence rate (P < 0.001) and distant metastasis rate (P = 0.001) in the ≥ 9 cycle group of stage III gastric cancer were statistically lower than those in the < 9 cycle group. The interaction analysis by Cox proportional hazard regression model showed that intestinal type, proximal gastrectomy, and ≥ 6 cm maximum diameter of tumor had a higher risk of total mortality in the < 9 cycles group. CONCLUSION: Overall, ≥ 9 chemotherapy cycles is not recommended for patients with stage II and stage III gastric cancer because it has an insignificant role in the prognosis of gastric cancer. However, for patients with stage III gastric cancer, ≥ 9 cycles of chemotherapy was shown to significantly decrease recurrence.

Partial replacement of soybean meal by yellow mealworm (Tenebrio molitor) meal influences the flesh quality of Nile tilapia (Oreochromis niloticus).

This study investigated the effects of yellow mealworm meal (YM) replacing soybean meal (SBM) at different proportions (0%, 15%, 30% and 45%, referred as YM0, YM15, YM30 and YM45, respectively) on the flesh quality of Nile tilapia. A total of 360 fish (70.0 ± 0.12 g) were randomly divided into 4 groups (3 tanks per group). Fish were fed the experimental diet twice daily for 10 wk. The results showed that muscle protein content significantly decreased in YM30 and YM45, while the lipid content significantly decreased in YM45 (P < 0.05). The essential amino acids and flavor amino acids of the muscle were not affected by the YM substitution, while saturated fatty acid content decreased in YM30 and YM45 compared with YM0 (P < 0.05). Fillets in YM45 had higher hardness, gumminess, and a higher proportion of thin myofibers (≤100 µm, P < 0.05) than those in other groups. Further analysis revealed that apoptosis and atrophy related genes were up-regulated, while the muscle antioxidant capacity decreased significantly in YM45 (P < 0.05), which may be related to the high acid value in YM45 diet. Our findings indicated that YM could replace up to 30% SBM without substantially altering the flesh quality. When the replacement ratio increased to 45%, the flesh quality would change. Special attention should be paid to avoid feed rancidity which may affect the flesh quality of fish.

Microbiota derived butyrate affected the muscle texture of Nile tilapia (Oreochromis niloticus) fed with different protein sources.

Flesh quality is influenced by diet components, but the underlying mechanism remains unclear. This study aimed to investigate the effect of replacing soybean meal (SBM) protein with cottonseed protein concentrate (CPC) at different levels (0%, CK; 15%, CPC15; 30%, CPC30 and 45%, CPC45) on the flesh quality of Nile tilapia. The results indicated that different protein sources influenced muscle amino acid composition instead of fatty acid composition. Lower muscle lipid content was found in CPC45, which in turn significantly altered the muscle texture. The hepatic lipid metabolism-related genes were detected and we found that CPC45 significantly suppressed the lipogenesis and promoted lipolysis. Higher content of microbiota-derived butyrate was found in the intestinal content of CPC45 and butyrate could decrease the lipid accumulation in vitro. Replacing SBM with CPC increased the intestinal butyrate to suppress the lipogenesis in the liver which may account for the increased muscle hardness.

Intestinal Microbiota Mediates Gossypol-Induced Intestinal Inflammation, Oxidative Stress, and Apoptosis in Fish.

Gossypol, the main antinutritional factor in cottonseed protein concentrate (CPC), could affect the growth conditions of fish, but the underlying mechanism remains unclear. In this study, an 8-week feeding trial was carried out to investigate the effects of gossypol on Nile tilapia (Oreochromis niloticus). Three experimental diets were designed, including control diet (CON), control diet supplemented with 150 mg/kg gossypol (ML), and 300 mg/kg gossypol (MH). 16S rRNA gene sequencing showed that gossypol significantly reduced the richness and diversity of the gut microbiota. Untargeted metabolite analysis revealed that most metabolites were down-regulated by gossypol, and riboflavin was the key metabolite with significant difference between CON-treated and gossypol-treated groups. Gossypol caused intestinal inflammation, oxidative stress, and apoptosis. Through fecal bacteria transplantation experiments, we demonstrated that intestinal microbiota mediated gossypol-induced negative effects, suggesting that intestinal microbiota and its metabolite may account for the harmful effects of gossypol.

Bacillus amyloliquefaciens ameliorates high-carbohydrate diet-induced metabolic phenotypes by restoration of intestinal acetate-producing bacteria in Nile Tilapia.

Poor utilisation efficiency of carbohydrate always leads to metabolic phenotypes in fish. The intestinal microbiota plays an important role in carbohydrate degradation. Whether the intestinal bacteria could alleviate high-carbohydrate diet (HCD)-induced metabolic phenotypes in fish remains unknown. Here, a strain affiliated to Bacillus amyloliquefaciens was isolated from the intestine of Nile tilapia. A basal diet (CON), HCD or HCD supplemented with B. amy SS1 (HCB) was used to feed fish for 10 weeks. The beneficial effects of B. amy SS1 on weight gain and protein accumulation were observed. Fasting glucose and lipid deposition were decreased in the HCB group compared with the HCD group. High-throughput sequencing showed that the abundance of acetate-producing bacteria was increased in the HCB group relative to the HCD group. Gas chromatographic analysis indicated that the concentration of intestinal acetate was increased dramatically in the HCB group compared with that in the HCD group. Glucagon-like peptide-1 was also increased in the intestine and serum of the HCB group. Thus, fish were fed with HCD, HCD supplemented with sodium acetate at 900 mg/kg (HLA), 1800 mg/kg (HMA) or 3600 mg/kg (HHA) diet for 8 weeks, and the HMA and HHA groups mirrored the effects of B. amy SS1. This study revealed that B. amy SS1 could alleviate the metabolic phenotypes caused by HCD by enriching acetate-producing bacteria in fish intestines. Regulating the intestinal microbiota and their metabolites might represent a powerful strategy for fish nutrition modulation and health maintenance in future.

Functional Characterization of Olfactory Proteins Involved in Chemoreception of Galeruca daurica.

Odorant-binding proteins (OBPs) and chemosensory proteins (CSPs) play a fundamental role in insect olfaction. Galeruca daurica (Joannis) is a new pest with outbreak status in the Inner Mongolia grasslands, northern China. In this study, six olfactory protein genes (GdauOBP1, GdauOBP6, GdauOBP10, GdauOBP15, GdauCSP4, and GdauCSP5) were cloned by RACE and expressed by constructing a prokaryotic expression system. Their binding affinities to 13 compounds from host volatiles (Allium mongolicum) were determined by fluorescence-binding assay. In order to further explore the olfactory functions of GdauOBP15 and GdauCSP5, RNA interference (RNAi) and electroantennogram (EAG) experiments were conducted. Ligand-binding assays showed that the binding properties of the six recombinant proteins to the tested volatiles were different. GdauOBP6, GdauOBP15, GdauCSP4, and GdauCSP5 could bind several tested ligands of host plants. It was suspected that GdauOBP6, GdauOBP15, GdauCSP4, and GdauCSP5 were related to the host location in G. daurica. We also found that there were different EAG responses between males and females when the GdauOBP15 and GdauCSP5 genes were silenced by RNAi. The EAG response of G. daurica females to 2-hexenal was significantly decreased in dsRNA-OBP15-injected treatment compared to the control, and the dsRNA-CSP5-treated females significantly reduced EAG response to eight tested host volatiles (1,3-dithiane, 2-hexenal, methyl benzoate, dimethyl trisulfide, myrcene, hexanal, 1,3,5-cycloheptatriene, and p-xylene). However, the EAG response had no significant difference in males. Both GdauOBP15 and GdauCSP5 may have different functions between males and females in G. daurica and may play more important roles in females searching for host plants.

[Ultrasound-guided needle-knife for trigger finger].

OBJECTIVE: To explore the efficacy of ultrasound-guided needle-knife with precise three-dimensional stereotactic localization of ashi points for stenosing tenosynovitis of flexor tendon (trigger finger). METHODS: A total of 74 patients were randomly divided into an observation group and a control group, 37 cases in each group. The patients in the observation group were treated with ultrasound-guided intrathecal injection and releasing method of needle-knife, while the patients in the control group were treated with ultrasound-guided intrathecal injection. The self-made 9-score scale of trigger finger was recorded before treatment, immediately after treatment, 1 month and 3 months after treatment; the curative effect of the two groups was evaluated. RESULTS: The results of self-made 9-score scale in the observation group immediately after treatment, 1 month and 3 months after treatment were lower than that before treatment (all P<0.01); the scores in the observation group were lower than those in the control group at each time point after treatment (all P<0.01). The excellent and good rate immediately after treatment was 100.0% (37/37) in the observation group, which was superior to 8.1% (3/37) in the control group (P<0.05); the cured rates in the observation group were 100.0% (37/37) 1 month after treatment and 97.3% (36/37) 3 months after treatment, which were superior to 13.5% (5/37) and 10.8% (4/37) in the control group, respectively (P<0.05). CONCLUSION: The needle-knife with three-dimensional stereotaxic location of ashi point could significantly improve the symptoms of trigger finger, with superior immediate and long-term efficacy.

Developmental dysplasia of the hip: A special pathology.

Developmental dysplasia of the hip (DDH) is one of the most common congenital disorders in childhood. Its diverse pathological changes require different treatments and result in different outcomes. Although many studies have been conducted on DDH, some special pathology is still unrecognized. We here presented a rare case of a one-year and eleven-month old girl with DDH; a half-free intra-articular osteocartilaginous tissue was found in her right hip joint. X-ray, computer assisted tomography (CT) and magnetic resonance imaging (MRI) were performed to evaluate the pathological changes. MRI revealed some positive findings. The patient experienced open reduction and histopathological examination of the small tissue. Through gross anatomy it is a half-free intra-articular osteocartilaginous tissue, which can fully match a fossa observed at the femoral head. Histopathological examination found that the tissue was composed of collagenous fiber and cartilage-like tissue. Interestingly, we found the expression of type I collagen according to immunohistochemical analysis, which indicated that the cartilage-like tissue was formed due to laceration of the articular cartilage. This kind of disorder should be included as one of the pathologies of DDH. The most possible origin of this tissue is the femoral head which we speculate may have been fractured before.

The surface protease ompT serves as Escherichia coli K1 adhesin in binding to human brain micro vascular endothelial cells.

Escherichia coli (E. coli) K1 is the most common bacteria that cause meningitis in the neonatal period. But it's not entirely clear about how E. coli crosses the blood-brain barrier. The features of the ompT deletion in meningitic E. coli infection were texted in vitro. In comparison with the parent strain, the isogenic ompT deletion mutant was significantly less adhesive to human brain microvascular endothelial cells (HBMEC). The adhesion-deficient phenotype of the mutant was restored to the level of the wild-type by complementing with low-level OmpT expression plasmid. Interestingly, the adhesion was enhanced by point mutation at the OmpT proposed catalytic residue D85. Compared with the poor adhesive activity of bovine serum albumin-coated fluorescent beads, recombinant OmpT or catalytically inactive variant of OmpT-coated beads bound to HBMEC monolayer effectively. Our study suggests that OmpT is important for bacterial adhesion while entering into central nervous system, and the adhesion does not involve in the proteolytic activity of OmpT.

Identification, organ expression and ligand-dependent expression levels of peroxisome proliferator activated receptors in grass carp (Ctenopharyngodon idella).

The peroxisome proliferator-activated receptors (PPARs) are ligand-dependent transcription factors belonging to the nuclear receptor family, and can regulate various genes involved in lipid metabolism. The aim of the present study was to investigate the tissue distribution patterns of PPARs and their ligand specificities in grass carp. We cloned three PPAR isotypes of the species and evaluated their organ distribution patterns using real-time PCR. Through analyzing the deduced amino acid sequences identities between the products cloned in grass carp and those described in other species, we concluded that the same type of PPAR amino acid sequences in different species were with high homology, and different subtypes of PPAR in the same species were with low homology. The mRNA constitutive expression level of PPARα predominated in the liver, but was weak in other tested tissues. PPARß was present in all tested organs, and particularly abundant in heart, liver and muscle. PPARγ was only detected in the liver, and to a lesser extent in brain, muscle and visceral adipose tissue. Grass carp were intraperitoneally injected with 50 mg kg(-1) body mass (bw) dose of clofibrate, 42 mg kg(-1) bw dose of 2-bromo palmitate and 1 mg kg(-1) bw dose of 15-deoxy-Δ(12,14) prostaglandin J2 (15d-PGJ2), respectively, and the relative changes of the mRNA abundance of PPARs in liver were analyzed by real-time PCR. Clofibrate was able to increase the expressions of both PPARα and ß, but was not able to for PPARγ. 2-bromo palmitate could affect the expressions of both PPARß and γ, but was not able to for PPARα. 15d-PGJ2 was able to induce PPARß expression, but PPARα and γ were not enhanced. Consequently, these results indicate that clofibrate, 2-bromo palmitate and 15d-PGJ2 could be applied as the activators of grass carp PPARs.

Predicting secondary structural folding kinetics for nucleic acids.

We report a new computational approach to the prediction of RNA secondary structure folding kinetics. In this approach, each elementary kinetic step is represented as the transformation between two secondary structures that differ by a helix. Based on the free energy landscape analysis, we identify three types of dominant pathways and the rate constants for the kinetic steps: 1), formation; 2), disruption of a helix stem; and 3), helix formation with concomitant partial melting of a competing (incompatible) helix. The third pathway, termed the tunneling pathway, is the low-barrier dominant pathway for the conversion between two incompatible helices. Comparisons with experimental data indicate that this new method is quite reliable in predicting the kinetics for RNA secondary structural folding and structural rearrangements. The approach presented here may provide a robust first step for further systematic development of a predictive theory for the folding kinetics for large RNAs.

Molecular cloning, characterization and mRNA expression of selenium-binding protein in abalone (Haliotis discus hannai Ino): Response to dietary selenium, iron and zinc.

Selenium-binding protein (SEBP) is believed to play crucial role in controlling the oxidation/reduction in the physiological processes. In this study, the cDNA of selenium-binding protein from abalone Haliotis discus hannai Ino (HdhSEBP) was cloned by homology cloning and rapid amplification of cDNA ends (RACE) technique. The full length of HdhSEBP cDNA was 2071 bp, consisting of a 5' untranslated region (UTR) of 55 bp, a 3' UTR of 522 bp, and an open reading frame (ORF) of 1494 bp. The deduced protein has 497 amino acid residues with a calculated molecular mass of 55.6 kDa and a predicted isoelectric point of 5.47. BLAST analysis reveals that HdhSEBP shares high identities with other known SEBPs from mammal, bird, fish and mollusk, etc. The mRNA expression patterns of HdhSEBP in hepatopancreas and haemocytes were measured by real-time PCR in abalone fed with nine different diets containing graded levels of selenium (0, 1 and 50 mg kg(-1)), iron (0, 65 and 1300 mg kg(-1)) and zinc (0, 35 and 700 mg kg(-1)) for 20 weeks, respectively. The results showed that the expression of the HdhSEBP mRNA increased and reached the maximum at optimal dietary selenium (1 mg kg(-1)), iron (65 mg kg(-1)) and zinc (35 mg kg(-1)), respectively. Deficient or excessive level of dietary selenium, iron or zinc, respectively, leaded to significant depression of HdhSEBP mRNA. It is concluded that the expression levels of HdhSEBP are affected by dietary selenium, iron or zinc.

[Chinese medicine for acute upper respiratory tract infection: a systematic review of randomized controlled trials].

OBJECTIVE: To evaluate the efficacy and safety of new drugs of traditional Chinese medicine (TCM) for acute upper respiratory tract infection (common cold). METHODS: Reports regarding randomized controlled trials of Chinese medicine for common cold were reviewed. Related reports were selected and the methodological quality of the trials was assessed by the Jadad scale. Meanwhile, the stratified analysis was made according to different TCM syndrome types of common cold. RESULTS: Thirteen randomized controlled trials consistent with the inclusion criteria were selected and reviewed. As TCM treatment group was compared with control group, the meta analysis indicated that the relative risk (RR) for obviously effective rate was 1.10, and the 95% confidence interval (CI) was [1.05, 1.16]; the weighted mean difference (WMD) of the onset time of lowering body temperature was -1.70, and the 95% CI was [-2.76, -0.65]. There were significant differences in the above evaluation indexes between the two groups (P=0.000 2, P=0.002). The WMD of disappearing time of fever was -1.32, and the 95% CI was [-3.14, 0.49], while there was no significant difference between the two groups (P=0.15). As the common cold patients with wind-heat syndrome in the TCM treatment group were compared with those in the control group, the meta analysis indicated that the RR for obviously effective rate was 1.11, the 95% CI was [1.05, 1.19], and there was significant difference between the two groups (P=0.000 7). As the common cold patients with wind-cold syndrome in the TCM treatment group were compared with those in the control group, the meta analysis indicated that the RR for obviously effective rate was 1.07, the 95% CI was [0.99, 1.16], and there was no significant difference between the two groups (P=0.10). Serious adverse reactions had not been reported in the trials. CONCLUSION: TCM new drugs developed in recent years for preventing and treating common cold have better therapeutic effects than the old ones. They can accelerate the onset time of lowering body temperature and improve the symptoms of common cold without any significant adverse reactions. Because of lacking of placebo-controlled and blank-controlled studies, further high-quality trials are still needed.

Amnesic shellfish poisoning toxin stimulates the transcription of CYP1A possibly through AHR and ARNT in the liver of red sea bream Pagrus major.

To investigate the role of detoxification-related liver genes in amnesic shellfish poisoning toxin metabolism, red sea bream Pagrus major were exposed to domoic acid (DA, 2mugg(-1) wet weight) for 24h. Hepatic mRNA expression levels of AHR, ARNT, CYP1 and GSTs were determined by semi-quantitative RT-PCR. The cytosolic factors aryl hydrocarbon receptor (AHR) and aryl hydrocarbon receptor nuclear translocator (ARNT) mRNA levels of DA exposure group were substantially enhanced by 113.3% and 90.9%, respectively. Consistent with this result, the phase I xenobiotic metabolizing enzyme (XME) cytochrome P-450 1A (CYP1A) was significantly induced. In contrast, the transcriptions of three major phase II XME glutathione S-transferases as well as heat shock protein 70 were not significantly affected by DA exposure. These results suggest a possible role of CYP1A after DA exposure in the toxin metabolism of marine fish, possibly through the AHR/ARNT signaling pathway.

[SDS-PAGE analysis of the antibacterial activity of the hemolymph from housefly larva].

OBJECTIVE: To study the inducible antibacterial activity of the hemolymph from housefly larva and analyze the antibacterial molecules. METHODS: The hemolymph was collected from the third instar housefly larvae 48 h after pricking treatment. Nine standard bacterial strains were used for determination of the antibaterial activity of the collected hemolymph and its combination with ampicillin. The anti-yeast activity of the hemolymph and its mixture with fluconazol was also assayed. The antibacterial molecules in the hemolymph was analyzed by SDS-PAGE. RESULTS: The growth of E.coli, Staphylococcus aureus, Staphylococcus albus, subserotypes of Shigeila flexneri, Bacillus proteus, Bacillus subtilis, Bacillus typhi, Bacillus paratyphosus, and Micrococcus lysodeikticus could be inhibited by the hemolymph collected from housefly larva, and the effect differed significantly between the groups (Plt;0.001). The hemolymph produced the strongest antibacterial activity against Micrococcus lysodeikticus, and the combination of the hemolymph with ampicillin most conspicuously inhibited the growth of Staphylococcus albus. The hemolyph and fluconazol exhibited obvious synergistic effect against yeast. SDS-PAGE identified some specific antibacterial molecules in the hemolymph. CONCLUSION: The induced hemolymph from housefly larva possesses strong antibacterial and antifungal activities especially against Micrococcus lysodeikticus. The hemolymph in combination with ampicillin produces the strongest effect against Staphylococcus albus, and fluconazol can significantly enhance the anti-yeast activity of the hemolymph through a synergistic mechanism.

[Clone, expression and immunoreaction of napA gene of Helicobacter pylori].

AIM: To construct a prokaryotic expression system of Helicobacter pylori(Hp) (neutrophil-activating protein) napA gene, analyze nucleic acid sequence and study its immunity and inflammation. METHODS: napA fragment was amplified from Hp NCTC11639 chromosomal DNA by PCR. Its T-A was cloned, sequenced and compared with other Hp strains on the GenBank. Then the gene was cloned into pGEX-4T-1 fusion expression vector, expressed in E.coli and purified by GST-affinity chromatography. The purified product was used to screen 29 stains of mouse anti Hp monoclonal antibodies(mAb) and its immunity and inflammation analyzed with sera of Hp-infected patients by Western blot. RESULTS: napA fragment was composed of 435 base pairs (GenBank No.DQ341279) and the nucleotide homology with other Hp strains on the GenBank was 94%-98%. The molecular weight of the recombinant napA-pGEX-4T-1 expressed in E.coli was 44 kDa. 3 of 29 anti-Hp mAbs were against NAP. Western blot analysis proved that the recombinant NAP was specifically recognized by the sera of Hp-infected patients. CONCLUSION: The recombinant NAP has original immunoreaction. It is of great value to clinical sero-diagnosis and vaccine study of Hp.

[Variability analysis of S2 gene of SARS-CoV].

OBJECTIVE: To determine the sequence of S2 gene of SARS-associated coronavirus (SARS-CoV) GD322 and analyze the phyletic evolution of S2 gene. METHOD: S2 gene fragment was amplified from SARS-CoV GD322 genome with RT-PCR and ligated to pGEM-T vector for sequence analysis after transformation of the plasmid into E. coli DH5a. The variability of S2 genes and S2 proteins from 12 strains isolated in the early, intermediate and advanced stages of the SARS outbreak were analyzed and the phylogenetic tree was constructed with Lasergene, Clustal X, DNAman and Treeview. T cell antigen epitopes of S2 protein were predicted on the basis of Internet database. RESULT: With the epidemic spread of SARS-CoV, the S2 genes of the virus tended to become stable. Homology of S2 genes of SARS-CoV isolated in advanced stage of the outbreak reached 99.9%. Prediction of T cell antigen epitope showed that mutation at the 57th amino acid effected T cell antigen epitope. CONCLUSION: S2 gene of GD322 SARS-CoV is relatively stable during the epidemic spread of the virus, and mutation at the 57th amino acids of S2 protein may affect the T cell antigen epitope.