Effect of Tubular Orientation on the Dentin Bond Strength of Acidic Self-etch Adhesives

The effectiveness of self-etch adhesive systems is dependent on both the physical properties of the adhesive and the integrity of the adhesive-dentin interface. Most importantly, the integrity of the adhesive-dentin interface is affected by the tubule orientation of the intaglio dentin structure. The initial bond strength and potential durability of the self-etch adhesive interfaces to dentin are significantly affected by both the adhesive pH and occlusally-oriented tubule direction. The clinical relevance to the dentist is that the results reported for bond strengths by both manufacturers and independent researchers should be interpreted and compared based on the orientation of the dentin used for the measurements, particularly for those adhesives that are very acidic (pH lower than 2).

Increased risk of cardiovascular disease in Type 1 diabetes: arterial exposure to remnant lipoproteins leads to enhanced deposition of cholesterol and binding to glycated extracellular matrix proteoglycans

AIMS

To determine fasting and postprandial metabolism of apolipoprotein B48 (apoB48) remnant lipoproteins in subjects with Type 1 diabetes and the relationship to progressive cardiovascular disease, and to investigate the impact of remnant lipoprotein cholesterol accumulation associated with arterial wall biglycan using a rodent model of Type 1 diabetes.

METHODS

Normolipidaemic subjects (n = 9) with long-standing Type 1 diabetes (and advanced cardiovascular disease) and seven healthy control subjects were studied. Fasting and postprandial apoB48 concentration was determined following a sequential meal challenge. A rodent model of streptozotocin-induced diabetes was used to investigate the ex vivo retention of fluorescent-conjugated remnants. Binding of remnant lipoproteins to human recombinant biglycan was assessed in vitro.

RESULTS

A significantly higher concentration of fasting plasma apoB48 remnants was observed in patients with Type 1 diabetes compared with control subjects. Patients with Type 1 diabetes exhibited a greater total plasma apoB48 area under the curve (AUC) and an increased incremental AUC following a second sequential meal compared with control subjects. The arterial retention of remnants ex vivo and associated cholesterol was increased sevenfold in Type 1 diabetes rats relative to controls. Remnants were shown to bind with significant affinity to human biglycan in vitro and a further 2.3-fold increased binding capacity was observed with glycated biglycan. Remnants were shown to colocalize with both arterial biglycan and glycated matrix proteins in the Type 1 diabetes rodent model.

CONCLUSION

Impaired metabolism of remnant lipoproteins associated with enhanced binding to proteoglycans appears to contribute to the arterial cholesterol deposition in Type 1 diabetes. Our findings support the hypothesis that impaired remnant metabolism may contribute to accelerated progression of atherosclerosis in the hyperglycaemic and insulin-deficient state.

Purification and characterization of two new allergens from the salivary glands of the horsefly, Tabanus yao

BACKGROUND

Horsefly bite can cause allergic reactions in humans. There is no information about allergenic horsefly proteins.

OBJECTIVES

The current work aims to purify and characterize IgE-binding proteins from horsefly salivary glands.

METHODS

Two IgE-binding proteins, Tab a 1 and Tab a 2 with molecular weight of 26 and 35 kd, respectively, were purified and characterized from 60,000 pairs of horsefly salivary glands of Tabanus yao, respectively. Their primary sequences were determined by Edman degradation and cDNA cloning. Their allergenicity was examined using enzyme-linked immunosorbent assay (ELISA), ELISA inhibition tests, and immunoblots.

RESULTS

Immunoblotting demonstrated IgE binding by 32 and 34 of 37 (86.5% and 91.8%) subjects' sera to Tab a 1 and Tab a 2, respectively. They were identified as an antigen 5-related (Ag 5) protein and hyaluronidase, respectively. ELISA inhibitions of serum IgE reactivity to the horsefly salivary gland extract (SGE) using purified Tab a 1 and Tab a 2 were significant (about 45%). In addition, these proteins showed some IgE-binding capacity to sera of subjects with wasp sting allergy.

CONCLUSIONS

We have first identified and characterized two IgE-binding proteins, Tab a 1, an Ag 5-like protein and Tab a 2, a hyaluronidase, from the horsefly salivary glands. They appear to be of importance for the allergic reactions induced by horsefly bite. These allergens are thus not only found in stinging but also found in hematophagous insects. These results also provided support for the presence of the so-called wasp-horsefly syndrome (WHS).

High expression of CXCR7 combined with Alpha fetoprotein in hepatocellular carcinoma correlates with extra-hepatic metastasis to lung after hepatectomy

The lung is the most frequent metastatic site of hepatocellular carcinoma (HCC), negatively impacting on survival rates. In this study, we evaluated the prognostic role of the chemokine receptor CXCR7 in lung metastasis of HCC after hepatectomy, using immunohistochemical detection on tissue microarrays of HCCs, with and without lung metastasis. Using three categories based on staining characteristics, patients with high CXCR7 expression demonstrated a shorter time to development of lung metastasis compared with patients with low CXCR7 expression (log-rank test) with no effet on overall survival. Analysis of tissue adjacent to tumor showed patients with microvascular invasion to have higher CXCR7. Stratification based on alpha fetoprotein level >20 ng/ml also showed high expression of CXCR7 to be a strong independent prognostic factor. These findings suggest that high expression of CXCR7 in HCCs with elevated alpha fetoprotein levels correlates with metastasis to lung and poor survival after hepatectomy, indicating potential use as a prognostic factor.

Application of constructed wetland for urban lake water purification: trial of Xing-qing Lake in Xi'an city, China

A comprehensive review of the current water pollution status in China has indicated that the urban lakes in Chinese cities have suffered from serious pollution and are in high risk of eutrophication, although the pollution sources have been largely controlled. The objective of this study lies in exploring a long term restoration of the aquatic ecosystem in Chinese city lakes using treatment wetland, an environmentally friendly and cost-effective technology. Trials from a subsurface horizontal flow constructed wetland (CW) have demonstrated that the treatment wetland can be used for a purpose such as lake water quality control. Average removal of 84.2% for COD, 53.8% for NH(3)-N, 47.9% for TN, 73.3% for TP and 86.6% for SS can be achieved. Relatively, low removal of nitrogen lies in the lack of nitrification and denitrification process. Accordingly, improved configuration of the treatment wetland system has been proposed and discussed. Finally, the importance of the integrated constructed wetland especially for the application of urban lake water treatment is highlighted.

The role of anti-inflammatory agents in age-related macular degeneration (AMD) treatment

Although age-related macular degeneration (AMD) is not a classic inflammatory disease like uveitis, inflammation has been found to have an important role in disease pathogenesis and progression. Innate immunity and autoimmune components, such as complement factors, chemokines, cytokines, macrophages, and ocular microglia, are believed to be heavily involved in AMD development. Targeting these specific inflammatory molecules has recently been explored in an attempt to better understand and treat AMD. Although antivascular endothelial growth factor therapy is the first line of defence against neovascular AMD, anti-inflammatory agents such as corticosteroids, nonsteroidal anti-inflammatory drugs (NSAIDs), immunosuppressive agents (eg, methotrexate and rapamycin), and biologics (eg, infliximab, daclizumab, and complement inhibitors) may provide an adjunct or alternative mechanism to suppress the inflammatory processes driving AMD progression. Further investigation is required to evaluate the long-term safety and efficacy of these drugs for both neovascular and non-neovascular AMD.

Elliptic flow of charged particles in Pb-Pb collisions at sqrt[S(NN)] = 2.76 TeV

We report the first measurement of charged particle elliptic flow in Pb-Pb collisions at sqrt[S(NN)] =2.76 TeV with the ALICE detector at the CERN Large Hadron Collider. The measurement is performed in the central pseudorapidity region (|η|<0.8) and transverse momentum range 0.2<p t<5.0 GeV/c. The elliptic flow signal v₂, measured using the 4-particle correlation method, averaged over transverse momentum and pseudorapidity is 0.087 ± 0.002(stat) ± 0.003(syst) in the 40%-50% centrality class. The differential elliptic flow v₂ p t reaches a maximum of 0.2 near p t =3 GeV/c. Compared to RHIC Au-Au collisions at sqrt[S(NN)] 200 GeV, the elliptic flow increases by about 30%. Some hydrodynamic model predictions which include viscous corrections are in agreement with the observed increase.

Charged-particle multiplicity density at midrapidity in central Pb-Pb collisions at sqrt[S(NN)] = 2.76 TeV

The first measurement of the charged-particle multiplicity density at midrapidity in Pb-Pb collisions at a center-of-mass energy per nucleon pair √ S NN = 2.76 TeV is presented. For an event sample corresponding to the most central 5% of the hadronic cross section, the pseudorapidity density of primary charged particles at midrapidity is 1584 ± 4(stat) ± 76(syst), which corresponds to 8.3 ± 0.4(syst) per participating nucleon pair. This represents an increase of about a factor 1.9 relative to pp collisions at similar collision energies, and about a factor 2.2 to central Au-Au collisions at √ S NN = 2.76 TeV. This measurement provides the first experimental constraint for models of nucleus-nucleus collisions at LHC energies.

Abstract P5-03-07: Adiponectin Deficiency Accelerated Breast Cancer Development and Promoted Cholesterol Accumulation in Mammary Tumors of MMTV-Polyomavirus Middle T Antigen Mice

Breast cancer is the most common cancer in women. Visceral obesity and body weight gain are associated with the increased risk of postmenopausal breast cancer. Adiponectin is an adipokine possessing anti-tumor activities against various types of obesity-related cancers. The present study has established a MMTV-polyomavirus middle T antigen (PyVT) transgenic mouse deficient with adiponectin (ADN) expression. Compared to the control mice [PyVT(+/−)ADN(+/+)], the development of mammary tumors in mice lacking this adipokine [PyVT(+/−)ADN(-/-)] was significantly accelerated. While the serum total cholesterol was progressively decreased from week 11 onwards, the cholesterol content in tumor tissues was elevated in both types of mice. The ratio between serum LDL-cholesterol and HDL-cholesterol was significantly higher in PyVT(+/−)ADN(-/-) mice than that in PyVT(+/−)ADN(+/+) mice. Adiponectin was able to inhibit cholesterol uptake in both MDA-MB-231 human breast cancer cells and the primary tumor cells isolated from PyVT transgenic mice. These data demonstrated that the anti-breast cancer activity of adiponectin was at least in part attributed to its suppressive effects on cholesterol accumulation in mammary tumors.

This work is supported by Research Grants Council of Hong Kong (Project no.777908M). Adiponectin knockout mice were kindly provided by Dr. Lawrence Chan at Baylor College of Medicine, who generated these mice with the support of the US National Institutes of Health grant HL-51586.

Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr P5-03-07.

Abstract P3-02-05: Evaluation of Gene Transcripts in Primary Tumors at Time of Diagnosis and Circulating Tumor Cells (CTCs) at Time of Metastatic Disease

Introduction: The enumeration of CTCs has already shown to bear clinical relevance as a prognostic and predictive factor in metastatic breast cancer. In addition to enumeration, isolation of CTCs enables their molecular characterization and thus holds great promise to establish association of their genetic profile with patient outcome and to identify potential drugable targets. In this study we established epithelial-specific mRNA and microRNA profiles in CTCs of patients with metastatic breast cancer, compared these profiles to the profiles measured in corresponding primary tumors, and determined their association with clinical parameters.

Study design:

For this study we included 50 breast cancer patients, of which 32 presented themselves with over 5 CTCs at the time of metastatic disease. From 14 of these patients with more than 5 CTCs at the time of metastatic disease also the primary tumor at time of breast cancer diagnosis was evaluated. Total RNA was extracted 1) from blood of the 50 patients with metastatic disease after EpCAM-based enrichment of 7.5 mL whole blood with the CellSearch™ Profile Kit [Veridex LCC], 2) from 14 unprocessed whole blood preparations from healthy blood donors, and 3) from 14 primary tumors. Gene transcript levels of CTC-specific and potentially clinically relevant mRNAs and microRNAs were compared in CTCs isolated at time of metastatic disease and the corresponding primary tumors. In addition, the association of these transcript levels with clinical data was assessed.

Results:

We identified 24 mRNA and 14 microRNAs more abundantly expressed in CellSearch-enriched fractions from patients with at least 5 CTCs compared with those without CTCs and/or compared with unprocessed whole blood prior to CellSearch enrichment (Mann-Whitney U-test P&lt;0.05). In addition, when comparing transcript levels present in CTCs during metastatic disease and those measured in the corresponding primary tumor, potentially clinically relevant discrepancies were observed. Findings of interest included changes in transcript levels of genes such as ESR1, ERBB2, TOP2A and MGB1, and in genes associated with proliferation and EMT. Finally, associations were observed between transcript levels measured in CTC preparations and clinical data like nodal status and size of the primary tumor.

Conclusion:

Our results show that molecular characterization of CTCs is feasible and has potential for a more tailored clinical approach above CTC enumeration in the treatment of metastatic breast cancer patients.

Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr P3-02-05.

Everolimus in renal cell carcinoma

Everolimus (also known as RAD-001; Afinitor®) is an orally active inhibitor of the intracellular protein kinase mammalian target of rapamycin. The U.S. Food and Drug Administration and the European Medicines Agency recently approved everolimus for the treatment of advanced renal cell carcinoma (RCC) on the basis of the results of a randomized phase III clinical trial. In the trial, 10 mg daily everolimus was effective and well tolerated by patients with advanced RCC, whose disease had progressed while under the treatment with sunitinib and/or sorafenib. Everolimus treatment led to 36% of 6-month progression-free survival (PFS) rate and 31% of 3-month PFS rate. Most of the adverse events were mild to moderate (grade 1-2) in severity. The most frequent grade 3-4 adverse events were stomatitis, fatigue, pneumonitis and infections. Clinical trials on everolimus in combination with sunitinib, sorafenib, imatinib and vatalanib for the treatment of RCC are ongoing.

Abstract P5-05-11: The Cellular Impact of HuR (Human (Hu) Antigen R) in Breast Cancer Cells on the Growth and Invasion In Vitro and the Expression of Cyclin D1 and MMP-9

Introduction: HuR, a ubiquitously expressed member of the Hu family, selectively binds and stabilizes ARE-containing mRNAs encoding proto-oncogenes, cell cycle regulators, cytokines and growth factors. The role of HuR and its cellular function in breast cancer remains unclear. In the present study, we aimed to provide new insights into the molecular and cellular implication of HuR in breast cancer.

Materials and methods. We first constructed a set of anti-HuR ribozyme transgenes that targeted human HuR. Breast cancer cells were transfected with the transgene, in order to establish new sublines with HuR expression knocked down. Cell growth and invasiveness were investigated using in vitro cell models. The expression of cyclin-D1 and MMP2 were determined using immunocytochemistry, Western blotting and polymerase chain reaction.

Results: Here, we show that MCF7 and MDA-MB-231 cells breast cancer cells stability transfected with a hammerhead ribozyme transgene specifically targeted to HuR (MCF7HuRKO and MDA-MB-231HuRKO) have a reduction in HuR expression both at mRNA and protein levels. Using these new sublines of breast cancer cells, the in vitro growth was evaluated. We showed that that HuR knockdown dramatically reduced cell growth in MCF7 cells (P &lt; 0.001) and to a lesser degree reduced that in MDA MB 231 cells. We further demonstrated that reduction of HuR in MDA MB 231 cells (MDA-MB-231HuRKO) resulted in a significant reduction of the in vitro invasiveness in MDA-MB-231 cells (P &lt; 0.001), although the same failed to occur to MCF-7 cells. Furthermore, we found that the decreased cell growth rate in MCF7 cells following HuR knockdown was seen together with a reduction in cyclin D1 transcript and protein levels. It was also interest to observe that the change in invasiveness in MDA-MB-231 cells after HuR knockdown was accompanied by a decrease in MMP-9 levels.

Conclusion: Our study shows that targeting HuR can influences breast cancer cell growth and invasion and suggests a role for HuR in vitro in enhancing breast cancer cell growth and invasion. These changes may be facilitated through changes in the level of cyclin D1 and MMP-9.

Citation Information: Cancer Res 2010;70(24 Suppl):Abstract nr P5-05-11.

Wnt/β-catenin activation promotes prostate tumor progression in a mouse model

Our previous studies have found that activation of Wnt/β-Catenin signaling resulted in mouse prostatic intraepithelial neoplasia (mPIN). In the large probasin promoter directed SV40-Large T-antigen (LPB-Tag) expressing mouse prostate, mPIN forms with rare areas of adenocarcinoma. Combining expression of both Wnt-signaling and Tag expression in the mouse prostate, we have studied the role of Wnt/β-Catenin signaling in the progression from mPIN to adenocarcinoma. Our results show that the prostates of mice expressing Tag alone or nuclear β-Catenin alone developed mPIN while the activation of both Tag and the Wnt/β-Catenin pathway resulted in invasive prostate adenocarcinoma. Also, Foxa2, a forkhead transcription factor, was induced by active Wnt/β-Catenin signaling; and the expression of Foxa2 was associated with the invasive phenotype in the primary prostate cancer. In the LPB-Tag/dominant active (D.A.) β-Catenin prostates, MMP7, a Wnt/β-Catenin target gene, was up-regulated. Furthermore, we also assessed AR and AR signaling pathway in these LPB-Tag/D.A. β-Catenin mice. Although β-Catenin is a well known AR co-activator in vitro, our study provides strong in vivo evidences indicating that both AR protein and the AR pathway were down-regulated in the prostate of LPB-Tag/D.A. β-Catenin mice. Histological analysis shows that prostate sections derived from the LPB-Tag/D.A. β-Catenin mice display neuroendocrine differentiation (NED) but NE cancer does not develop. Together, our findings indicate that Wnt/β-Catenin signaling plays an important role in the progression of mPIN to prostate adenocarcinoma.

Clinicopathological implications of tumour-associated macrophages and vascularization in sinonasal melanoma

This study investigated tumour-associated macrophages (TAMs) and their effects on tumour vascularization in sinonasal melanoma (SNM). Data on 45 patients with SNM undergoing surgery were reviewed retrospectively. Tumour sections were analysed immunohistochemically for TAMs, microvessels, lymph vessels, and vasculogenic mimicry in both intra- and peritumoural areas. The density of intratumoural TAMs was associated with tumour thickness and with overall survival in SNM stages I and II but there were no correlations between micro- or lymph vessel density and TAM infiltration. Greater TAM infiltration was observed in tumour tissues with vasculogenic mimicry although this was not statistically significant. These data suggest that high intratumoural TAM infiltration is associated with tumour aggressiveness and a poor prognosis for SNM, and that activation of macrophages can be polarized by different micro-environments. TAMs could be potential prognostic indicators for patients with SNM.

A randomized prospective study of rehabilitation therapy in the treatment of radiation-induced dysphagia and trismus

PURPOSE

To evaluate the therapeutic effect of rehabilitation therapy on radiation-induced dysphagia and trismus in nasopharyngeal carcinoma (NPC) patients after radiotherapy.

PATIENTS AND METHODS

43 NPC patients after radiotherapy were included. Patients were randomly assigned to either the rehabilitation group or a control group. Both groups were subjected to routine treatment, while the rehabilitation group also received rehabilitation therapy for 3 months. The severity of dysphagia was assessed using the water swallow test, while trismus was evaluated with the LENT/SOMA score and the interincisor distance (IID). The water swallow test, the LENT/SOMA score, as well as IID for both groups before and after treatment were analyzed and compared.

RESULTS

After treatment, the rehabilitation group displayed a significant improvement in swallowing function, while the control group did not. The efficacy rate (percentage of patients with excellent or effective results) of rehabilitation group was higher than that of control group (77% vs. 43%), and the difference was statistically significant (ϰ(2) = 5.32, p = 0.02). IID pretreatment and posttreatment did not show much difference in the rehabilitation group, while in the control group IID significantly decreased posttreatment (1.1 ± 0.36 cm vs.1.8 ± 0.56 cm, p = 0.001). Although the mean IID in patients of both groups decreased after the 3 month follow-up, the decrease in the rehabilitation group was less than that of the control group (0.19 ± 0.5 cm vs. 0.69 ± 0.56 cm, p = 0.004 ). The efficacy rate of trismus in the rehabilitation group was significantly higher than that of the control group (64% vs. 28%, ϰ(2) = 5.31, p = 0.02).

CONCLUSIONS

Rehabilitation training can improve swallow function and slow down the progress of trismus in NPC patients following radiotherapy.

Granulocyte colony-stimulating factor attenuates chronic neuroinflammation in the brain of amyloid precursor protein transgenic mice: an Alzheimer's disease mouse model

Recent evidence suggests that inflammatory mechanisms contribute significantly to the progression of Alzheimer's disease. Granulocyte colony-stimulating factor (G-CSF) is an anti-inflammatory immunomodulator, but the mechanism of its anti-inflammatory effect is unclear. This study was designed to investigate whether G-CSF could inhibit inflammation in a mouse model of Alzheimer's disease through an α7 nicotinic acetylcholine receptor (α7 nAChR) pathway. Mice transgenic for the V171I mutant amyloid precursor protein (APP) were injected subcutaneously with G-CSF 50 μg/kg per day or phosphate-buffered saline (PBS; control group) for 7 days, and wild-type C57/BL6 mice were injected with PBS daily for 7 days. Mice were killed on days 7, 14 and 28 after treatment began. Levels of α7 nAChR protein were significantly increased and levels of interleukin-1β, tumour necrosis factor-α and nuclear factor-κB (NF-κB) protein were significantly decreased in the brain of APP transgenic mice in response to G-CSF. Levels of α7 nAChR protein correlated negatively with NF-κB levels. It is concluded that G-CSF might attenuate inflammation by down-regulating NF-κB and up-regulating α7 nAChR in the brain of APP transgenic mice, indicating a potential new therapeutic approach to Alzheimer's disease.

Up-regulated expression of Notch1 and Jagged1 in human colon adenocarcinoma

Deregulated expression of Notch molecules is observed in many malignant tumors, however, the expression of Notch1 and Jagged1 in colon adenocarcinoma is still unknown. This study is to investigate the expression of Notch1 and Jagged1 in human colon adenocarcinoma. Sixty-five human colon adenocarcinoma and 60 adjacent nontumor colon tissue sections were detected by immunohistochemistry. Ten paired fresh surgical human colon adenocarcinoma and adjacent nontumor colon samples were analyzed by Western blot and RT-PCR. Both Notch1 and Jagged1 were expressed in the cytoplasm of neoplastic cells of colon adenocarcinoma tissue. The protein and mRNA levels of both molecules were higher in colon adenocarcinoma than in adjacent nontumor tissue. Moreover, Notch1 was positively correlated with tumor stage. This investigation demonstrates that Notch1 and Jagged1 are up-regulated in human colon adenocarcinoma and suggests that Notch1/Jagged1 signaling might play a role in the development of colon adenocarcinoma.

Electric and magnetic excitation of coherent magnetic plasmon waves in a one-dimensional meta-chain

A one-dimensional diatomic meta-chain with equal-size holes and different-length slits is designed. Broadband coherent magnetic plasmon waves (MPW) are formed in such a system, excited by both the electric resonance in the slits and the magnetic resonance in the holes in a wide range of incidence angles (0°-40°) and broad frequency bands (200-230 THz). The dispersion properties of the MPW measured in our experiments agree with the theoretical calculation based on the Lagrange model. The coherent MPWs reported in this paper may have applications in subwavelength integrated nanocircuits.

How active are American adolescents and have they become less active?

The aim of this study was to systematically examine patterns and time trends in US adolescents' physical activity (PA) and sedentary behaviours. We examined findings from the nationally representative Youth Risk Behavior Surveillance Surveys during 1991-2007, and fit regression models estimating average annual changes and tested time trends, and age, gender and ethnic differences. US adolescents had less PA but more sedentary behaviours than recommended, but showed no clear evidence of becoming less active. In 2007, 24.9% reported on average spending ≥3 h of screen time per day for non-school work; only 34.7% met the current PA recommendations, and it (25.6%) was even lower in girls. The prevalence of having sufficient vigorous PA changed little between 1993 and 2005 (from 65.8% to 64.1%). Encouraging changes regarding TV viewing time and physical education (PE) were detected. PE daily attendance rate and exercising >20 min during an average PE class increased significantly, while watching TV ≥3 h d⁻¹ decreased significantly in recent years. Considerable sex, age and ethnic differences existed in the patterns and trends. These national data show no clear evidence of declining PA among US adolescents in recent years. Reduced PA is not likely the major explanation of the recent increase in obesity among US adolescents.

Comparative analysis of the phenotypic characteristics of high- and low-virulent strains of Edwardsiella tarda

Edwardsiella tarda is a causative agent of edwardsiellosis in freshwater and marine fish. Extracellular enzymic, haemolytic, hydrophobic and serum resistance activities, haemagglutination, autoagglutination and siderophores of high- and low- virulent E. tarda strains were examined. The results revealed different haemagglutination, autoagglutination, haemolytic, hydrophobic and serum resistance activities in different strains. Analysis of extracellular proteins (ECPs) and outer membrane proteins (OMPs) demonstrated several major, low molecular weight, virulent-strain-specific proteins, which could be virulence-related. Based on the database search with MALDI-TOF MS data, the closest homologies of the three protein bands Ed1, Ed2 and Ed3 were phosphotransferase enzyme family protein, nitrite reductase [NAD(P)H], large subunit and ATP-dependent Lon protease, respectively. A comparison of pathogenicity of purified lipopolysaccharide (LPS) and lipid A from virulent and avirulent strains demonstrated that LPS was one of the virulence factors of the E. tarda isolates, and lipid A was a biologically active determinant of LPS.

Phylogeography and conservation genetics of Lake Qinghai scaleless carp Gymnocypris przewalskii

The objective of this study was to examine the spatial genetic relationships of the Lake Qinghai scaleless carp Gymnocypris przewalskii within the Lake Qinghai system, determining whether genetic evidence supports the current taxonomy of Gymnocypris przewalskii przewalskii and Gymnocypris przewalskii ganzihonensis and whether Gymnocypris przewalskii przewalskii are returning to their natal rivers to spawn. Comparison of mitochondrial (control region) variation (42 haplotypes in 203 fish) of G. przewalskii with the postulated ancestral species found in the Yellow River, Gymnocypris eckloni (10 haplotypes in 23 fish), indicated no haplotype sharing, but incomplete lineage sorting. Consistent with the sub-species status, an AMOVA indicated that the Ganzi River population was significantly different from all other river populations (F(ST) = 0·1671, P < 0·001). No genetic structure was found among the other rivers in the Lake Qinghai catchment. An AMOVA of amplified fragment length polymorphism (AFLP) loci, however, revealed significant genetic differences between most spawning populations (F(ST) = 0·0721, P < 0·001). Both mitochondrial and AFLP data found significant differences among G. p. przewalskii, G. p. ganzihonensis and G. eckloni (F(ST) values of 0·1959 and 0·1431, respectively, P < 0·001). Consistent with the incomplete lineage sorting, Structure analysis of AFLP loci showed evidence of five clusters. One cluster is shared among all sample locations, one is unique to G. p. ganzihonensis and G. eckloni, and the others are mostly found in G. p. przewalskii. Genetic evidence therefore supports the current taxonomy, including the sub-species status of G. p. ganzihonensis, and is consistent with natal homing of most Lake Qinghai populations. These findings have significant implications for the conservation and management of this unique and threatened species. The evidence suggests that G. p. przewalskii should be treated as a single population for conservation purposes. Exchangeability of the populations, however, should not be used to promote homogenization of fish spawning in the different rivers. As some degree of genetic divergence was detected in this study, it is recommended that the spawning groups be treated as separate management units.