Systematic analysis of prophages carried by Porphyromonas gingivalis.

To systematically investigate the prophages carrying in Porphyromonas gingivalis (P. gingivalis) strains, analyze potential antibiotic resistance genes (ARGs) and virulence genes in these prophages. We collected 90 whole genome sequences of P. gingivalis from NCBI and utilized the Prophage Hunter online software to predict prophages; Comprehensive antibiotic research database (CARD) and virulence factors database (VFDB) were adopted to analyze the ARGs and virulence factors (VFs) carried by the prophages. Sixty-nine prophages were identified among 24/90 P. gingivalis strains, including 17 active prophages (18.9%) and 52 ambiguous prophages (57.8%). The proportion of prophages carried by each P. gingivalis genome ranged from 0.5% to 6.7%. A total of 188 antibiotic resistance genes belonging to 25 phenotypes and 46 different families with six mechanisms of antibiotic resistance were identified in the 17 active prophages. Three active prophages encoded 4 virulence genes belonging to type III and type VI secretion systems. The potential hosts of these virulence genes included Escherichia coli, Shigella sonnei, Salmonella typhi, and Klebsiella pneumoniae. In conclusion, 26.7% P. gingivalis strains carry prophages, while the proportion of prophage genes in the P. gingivalis genome is relatively low. In addition, approximately 39.7% of the P. gingivalis prophage genes have ARGs identified, mainly against streptogramin, peptides, and aminoglycosides. Only a few prophages carry virulence genes. Prophages may play an important role in the acquisition, dissemination of antibiotic resistance genes, and pathogenicity evolution in P. gingivalis.

[Pulmonary vein stenosis with pulmonary infarction secondary to primary mediastinal seminoma: a case report].

Pulmonary vein stenosis is a rare condition that is often underdiagnosed and misdiagnosed. The clinical and radiologic manifestations are unspecific such as cough, hemoptysis and pulmonary lesions and are therefore difficult to distinguished with pneumonia and tuberculosis. The present study is a successful case report of pulmonary vein stenosis and pulmonary infraction secondary to mediastinal seminoma. This case suggested that pulmonary vein stenosis should be considered when a mediastinal mass is accompanied by pulmonary opacites that cannot be explained by common causes such as infection.

[Analysis of spirometer data of 5272 coal dust-exposed miners].

Objective: To analyze the spirometer data of coal mine workers, explore the impact of coal dust on the lung function of coal mine workers. Methods: From June to December 2018, 5272 male coal mine dust-exposed workers who underwent occupational health examinations at the Xinjiang Uygur Autonomous Region Occupational Disease Prevention and Treatment Hospital were selected as the research subjects. The basic information and spirometer data of the workers were collected and analyzed for different ages, years of service and the degree of lung function injury of workers exposed to dust and its influencing factors. Results: The total detection rate of lung function injury among dust-exposed workers was 33.9% (1785/5272) . The type of injury was mainly restrictive ventilatory dysfunction (66.7%, 1190/1785) , followed by mixed ventilatory dysfunction (31.4%, 561/1785) , obstructive ventilatory dysfunction (1.9%, 34/1785) . The detection rate of mild lung function impairment was 21.0% (1105/5272) , The detected rate of moderate or higher lung injury was 12.9% (680/5272) . The abnormal detection rate of chest radiography was 3.4% (179/5272) . The logistic regression analysis of the factors affecting lung function damage showed that employees aged 40-<50 were more likely to detect overall lung function injury and the moderate or higher lung injury (P<0.05) , and that they had been working for 35 to 45 years and excavators were more likely to detect overall function injury and different degree of lung injury (P<0.05) . Conclusion: The lung function injury of coal mine dust-exposed workers is related to their age, dust-exposed working years and type of work, mainly with mild injury and restrictive ventilation dysfunction.

[Surgical treatment of lung cancer patients with idiopathic pulmonary fibrosis].

Lung cancer is the leading cause of death in malignant tumors. Surgery is one of the main treatments for early stage lung cancer. Idiopathic pulmonary fibrosis (IPF), one of the most common interstitial lung disease, is a chronic, progressive lung disease, characterized by insidious onset and progressive deterioration. It is reported that there are common pathways in idiopathic pulmonary fibrosis and lung cancer, and patients with IPF have a higher risk of lung cancer than the general population, whose prevalence was 3.34 times than that of the general population. The incidence of acute exacerbations of IPF and postoperative mortality was significantly higher in lung cancer patients complicated with IPF than those without IPF. The long-term outcomes of patients with IPF are dramatically worse than those without IPF. It was concluded that lobectomy has been still the standard surgical procedure for such patients, but sublobectomy should be taken as potential alternative choice for patients with high risk after preoperative evaluation. Moreover, further studies should be conducted on the prevention and treatment of acute exacerbation of IPF after surgery.

[Effects of overexpression of Notch intracellular domain on proliferation and osteogenic differentiation of human periodontal ligament stem cells].

Objective: To investigate the effect of overexpression of Notch intracellular domain (NICD) on proliferation and osteogenic differentiation of human periodontal ligament stem cells (hPDLSC). Methods: The third generation hPDLSC with stable overexpressing of NICD were assigned as experimental group, normal hPDLSC were as negative control group and hPDLSC transfected with empty vector were as blank control group. The effect of overexpressing NICD on proliferation ability of hPDLSC was detected by using cell counting kit-8 (CCK-8). Alizarin Red staining and real-time quantitative PCR (qPCR) were used to detect the effects of NICD on cementum attachment proteins (CAP), osteocalcin (OCN), Runt-related transcription factor 2 (RUNX2) and Notch signal pathway receptor Notch1. The effect of overexpressing NICD on hPDLSC osteogenic protein RUNX2 and flag marker protein (used to label NICD) were detected by using Western blotting. Results: CCK-8 results showed that there were no significant differences in A values amongst the three groups for 1-2 days (P>0.05). The number of cells in the experimental group was significantly increase than that of the two control groups from the third to seventh days (A values were 0.203±0.016, 0.364±0.014, 0.449±0.020, 0.549±0.020 and 0.570±0.020, respectively) (P<0.05). Alizarin red staining showed that compared with the blank control group and negative control group, the mineralized nodules in the experimental group had smaller formation range and lighter color, and the differences were statistically significant (P<0.05). The expressions of CAP gene (0.751±0.058, 0.887±0.025), osteocalcin gene (0.592±0.051, 0.670±0.045) and RUNX2 gene (0.319±0.038, 0.684±0.055) at 14 and 21 days in the experimental group were significantly lower than those in the negative control group respectively (P<0.05). However, the expression levels of Notch1 gene at 14 and 21 days (2.507±0.047, 4.041±0.219) were significantly higher than those of negative and blank control groups (P<0.05). The results of Western blotting showed that the expressions of flag marker protein (0.167±0.007, 0.204±0.010) at 14 and 21 days in the experimental group were significantly higher than those in the negative and blank control groups (P<0.05). However, the expressions of RUNX2 protein (0.075±0.006, 0.074±0.013) at 14 and 21 days were significantly lower than that in the negative control group (0.092±0.003, 0.118±0.008) and blank control group (0.174±0.006, 0.212±0.008) (P<0.05). Conclusions: Overexpression of NICD can promote the proliferation capacity of hPDLSC and inhibit its osteogenic differentiation.

TC > 0.05 as a Pharmacokinetic Parameter of Paclitaxel for Therapeutic Efficacy and Toxicity in Cancer Patients.

BACKGROUND: Paclitaxel (PTX) has remarkable anti-tumor activity, but it causes severe toxicities. There is an urgent need to seek an appropriate pharmacokinetic parameter of PTX to improve treatment efficacy and reduce adverse effects. OBJECTIVE: To evaluate the association of pharmacokinetic parameter TC > 0.05 of paclitaxel (PTX) and its therapeutic efficacy and toxicity in patients with solid tumors. METHODS: A total of 295 patients with ovarian cancer, esophageal cancer, breast cancer, and non-small cell lung cancer (NSCLC), who were admitted to the Tumor Hospital of Shantou University Medical College, China, were recruited for this study. Patients received 3 weeks of PTX chemotherapy. The plasma concentrations of PTX were examined using the MyPaclitaxel™ kit. The patients' PTX TC > 0.05 (the time during which PTX plasma concentration exceed 0.05µmol/L) were calculated based on pharmacokinetic analysis. RESULTS: The results showed that: (1) the concentrations of PTX in these 295 patients ranged from 0.0358-0.127 µmol/L; (2) the PTX TC > 0.05 ranged from 14 to 38h with a median time of 27h; (3) among all treatment cycles, there was a statistically significant difference in the PTX TC > 0.05 between CR+PR and SD+PD; (4) with the increasing value of TC > 0.05, level of leukopenia and leukopenic fever increased; (5) high PTX TC > 0.05 led to the occurrence of neutropenia, neutropenic fever, severe anemia, and severe peripheral neurotoxicity. Taken together, our results indicated that the pharmacokinetic parameter PTX TC > 0.05 was an effective measure of treatment efficacy and toxicity in patients with solid tumors. Maintaining PTX TC > 0.05 at 26 to 30h could improve its efficacy and reduce the incidence of leukopenia, neutropenia, anemia, and peripheral neurotoxicity in these patients. CONCLUSION: PTX TC > 0.05 is a key pharmacokinetic parameter of PTX which should be monitored to optimize individual treatment in patients with solid tumors.

Effects of graded levels of microbial phytase on apparent total tract digestibility of calcium and phosphorus and standardized total tract digestibility of phosphorus in four sources of canola meal and in soybean meal fed to growing pigs.

One hundred twenty pigs were used to determine effects of graded levels of microbial phytase on the apparent total tract digestibility (ATTD) of P and Ca and the standardized total tract digestibility (STTD) of P in 4 sources of canola meal and in 1 source of soybean meal (SBM) fed to growing pigs. The 4 sources of canola meal were produced from 1 source of high-protein canola seeds and 2 sources of conventional canola seeds with 1 of the conventional canola seeds being divided into 2 separate batches before crushing. Pigs (16.2 ± 5.3 kg initial BW) were individually housed in metabolism crates and were randomly allotted to 1 of 20 diets in a 5 × 4 factorial arrangement of treatments with 5 ingredients and 4 levels of phytase. There were 6 replicate pigs per diet. Five basal diets based on high-protein canola meal (CM-HP), high-temperature processed canola meal (CM-HT), low-temperature processed canola meal (CM-LT), conventional canola meal (CM-CV), or SBM were formulated. The basal diets contained no phytase. Fifteen additional diets were prepared by adding approximately 500, 1,500, or 2,500 phytase units/kg to each of the 5 basal diets. Feces were quantitatively collected for 5 d based on the marker-to-marker approach after a 7-d adaptation period. Results indicated that supplementation of microbial phytase increased (linear, < 0.05) the ATTD of Ca in diets containing CM-HP, CM-HT, CM-CV, and SBM but not in diets containing CM-LT. Microbial phytase also increased (linear and quadratic, < 0.05) the ATTD and STTD of P in all 5 ingredients. Compared with the CM-CV diets, the CM-HP diets had greater ( < 0.05) ATTD of Ca. The ATTD of Ca in the SBM diet was greater ( < 0.05) than in all canola meal diets, but no differences were observed in ATTD of Ca between CM-HT and CM-LT diets. The ATTD and the STTD of P were less ( < 0.05) in CM-HP, CM-HT, CM-LT, or CM-CV than in SBM if no microbial phytase was added, but no differences were observed in the ATTD and STTD of P in SBM, CM-HP, CM-HT, or CM-CV if the highest amount of phytase were added (interaction, < 0.05). Regression equations were developed to calculate the response to microbial phytase on the STTD of P in CM-HP, CM-HT, CM-LT, CM-CV, and SBM. In conclusion, inclusion of graded levels of microbial phytase increased the ATTD and STTD of P in CM-HP, CM-HT, CM-LT, CM-CV, and SBM and the response to microbial phytase added to each ingredient can be predicted by regression equations.

Body height and the spread of spinal anaesthesia for caesarean section: a prospective controlled trial.

BACKGROUND: No conclusive evidence exists on the effect of patient height on the spread of spinal anaesthesia. Our aim was to measure the ED50 and ED95 values of intrathecal ropivacaine in taller and shorter patients, and thus investigate the hypothesis that the spinal dose requirement in shorter patients is lower than that in taller patients undergoing caesarean section. METHODS: In this study, 270 pregnant women were assigned to the taller (Group T) or shorter group (Group S) based on their heights. Subjects in both groups were further randomly assigned to one of nine subgroups based on the dosage of intrathecal isobaric ropivacaine to be administered (7, 8, 9, 10, 11, 12, 13, 14 or 15 mg respectively). RESULTS: The ED50 and ED95 values of ropivacaine were 9.24 mg and 13.36 mg in Group S, and 10.11 mg and 14.63 mg in Group T, with no inter-group difference (P = 0.886). There was a significant inter-group difference in the incidence of hypotension and the changes in mean arterial pressure after spinal anaesthesia using 15 mg ropivacaine. The dose of ephedrine administered in Group S was higher than that in Group T when 15 mg ropivacaine was administered (P = 0.031). CONCLUSION: The taller and shorter patients did not respond differently to modest intrathecal doses of ropivacaine. However, a larger dose of ropivacaine was associated with an increased incidence of hypotension in shorter patients compared to that in taller patients.

Ghrelin to obestatin ratio in maternal serum in pregnancies complicated by intrauterine growth restriction.

Ghrelin, an endogenous for the growth hormone secretagogue receptor, has been shown to participate in fetal growth. Obestatin, encoded by the same gene as ghrelin, is described as a physiological opponent of ghrelin. This study was designed to determine the changes of ghrelin/obestatin ratio in maternal serum in pregnancies with intrauterine growth restriction (IUGR). The authors found that the ghrelin levels in maternal serum were significent lower in IUGR group than in control group (236.34 ± 14.58 pg/ml vs. 321.49 ± 18.19 pg/ml, p = 0.003). However, the difference of obestatin levels in maternal serum in IUGR group than in control group was not significent (276.25, ±20.54 pg/ml vs. 256.34 ± 21.21 pg/ml, p = 0.308). The ratio of ghrelin to obestatin in maternal serum were significent lower in UGR group than in control group (1.05 ± 0.09 vs. 0.82 ± 0.08, p = 0.03). Meanwhile, the maternal serum growth hormone (GH) concentration in IUGR group was lower than that in control group (1.08 ± 0.08 pg/ml vs. 1.41 ± 0.09 pg/ml, p = 0.009), and the maternal serum pla- cental growth hormone (PGH) concentration in IUGR group was lower than that in control group (2.21 ± 1.24 pg/ml vs. 2.92 ± 0.27 pg/ml,p = 0.031). The ratio of ghrelin to obestatin in maternal serum were positively correlation with GH and PGH concentrations in IUGR group (r = 0.876, p = 0.52; r = 0.764, p = 0.64). The findings of this study suggest that the ratio of ghrelin to obestatin in maternal serum were low, and were positively correlated with GH and PGH concentration in IUGR group, which can been considered as evidencees of ghrelin/obestatin balance disorder role in pathogenesis of IUGR.

[The expression and clinical significance of survivin in salivary gland adenoid cystic carcinoma: a Meta analysis].

Objective:This Meta-analysis was performed to explore the association between survivin expression and clinical pathological features of salivary gland adenoid cystic carcinoma (SACC). Method:Literature was searched in some databases such as PubMed, Embase, Cochrane Library, web of science, OVID, Springerlink, CNKI, CBM, Wanfang and CQVIP. The pooled odds ratios (ORs) and 95% confidence intervals (95% CIs) were estimated to determine the correlation between survivin expression and SACC using a fixed or random effects model according to heterogeneity. Result:A total of ten studies with 367 SACC patients and 124 normal control subjects were included in this Meta-analysis. The results showed that survivin was overexpressed in SACC tissues (OR=38.26, 95% CI: 17.37-84.29, P<0.01). It also revealed significant correlations between survivin expression and pathological types (OR=0.3, 95% CI: 0.17-0.55, P<0.01), advanced tumor clinical stages (OR=0.23, 95% CI: 0.13-0.42, P<0.01) and lymph node metastasis (OR=3.7, 95% CI: 1.82-7.56, P<0.01). Conclusion:The current study demonstrated that survivin expression may be associated with the clinical pathological features of SACC. However, due to the influence of the quantity and quality of the included literature, additional high quality of studies with larger sample sizes are needed to confirm our findings.

Robust reduced-rank regression.

In high-dimensional multivariate regression problems, enforcing low rank in the coefficient matrix offers effective dimension reduction, which greatly facilitates parameter estimation and model interpretation. However, commonly used reduced-rank methods are sensitive to data corruption, as the low-rank dependence structure between response variables and predictors is easily distorted by outliers. We propose a robust reduced-rank regression approach for joint modelling and outlier detection. The problem is formulated as a regularized multivariate regression with a sparse mean-shift parameterization, which generalizes and unifies some popular robust multivariate methods. An efficient thresholding-based iterative procedure is developed for optimization. We show that the algorithm is guaranteed to converge and that the coordinatewise minimum point produced is statistically accurate under regularity conditions. Our theoretical investigations focus on non-asymptotic robust analysis, demonstrating that joint rank reduction and outlier detection leads to improved prediction accuracy. In particular, we show that redescending [Formula: see text]-functions can essentially attain the minimax optimal error rate, and in some less challenging problems convex regularization guarantees the same low error rate. The performance of the proposed method is examined through simulation studies and real-data examples.

[Effects of anti-PD-L1 monoclonal antibody and EGFR-TKI on the expression of PD-L1 and function of T lymphocytes in EGFR-mutated lung cancer cells].

Objective: To investigate the effects of anti-PD-L1 monoclonal antibody and EGFR-TKI on expression of soluble PD-L1 and function of T lymphocytes in EGFR-mutated lung cancer cells. Methods: Flow cytometry was used to analyze the expression of membrane PD-LI. ELISA was performed to detect the level of sPD-L1 in the supernatant of cultured EGFR-mutated and wild type lung cancer cells before and after erlotinib treatment.After treated with anti-PD-L1 monoclonal antibody alone and in combination with erlotinib, the proliferation of T lymphocytes in co-culture system was measured using Cell Counting Kit-8 (CCK-8) assay. The expression levels of PD-LI and IFN-γ in tumor cells and T lymphocytes treated with erlotinib in co-culture system were analyzed by flow cytometry and ELISA, respectively. Results: PD-L1 was highly expressed in EGFR-mutated lung cancer PC9 cells (78.7±3.1)% and HCC827 cells (82.7±2.6)%.After treated with erlotinib, the expression rates of membrane PD-L1 in PC9 and HCC827 cells were down-regulated (64.7%±3.1% and 73.0%±2.6%, respectively), significantly lower than that in the two cell lines without erlotinib treatment (P<0.05), and the expression levels of sPD-L1 in the supernatant of PC9 and HCC827 cells were also down-regulated (0.680±0.120)ng/ml and (0.903±0.047)ng/ml, respectively, significantly lower than that in the two cell lines without erlotinib treatment (P<0.01). However, no significant changes of membrane PD-L1 and sPD-L1 expression were found in EGFR wild type lung cancer cells (H1299 and A549) before and after erlotinib treatment. In the co-culture system composed of T cells and EGFR-mutated lung cancer cells, treatment with erlotinib alone promoted the proliferation of T lymphocytes (P<0.05), and combined treatment of anti-PD-L1 monoclonal antibody with erlotinib had a stronger effect (P<0.05). In the co-culture system composed of T cells and EGFR wild type cell lines, the proliferation of T cells was not changed after using erlotinib alone or combination of erlotinib and anti-PD-L1 monoclonal antibody (P>0.05). Before and after treatment with erlotinib, the secretion levels of IFN-γ were (856.0±70.3)pg/ml and (1 697.3±161.0)pg/ml, respectively, showing a significant difference (P<0.001). The expression rates of membrane PD-L1 were (76.2±0.5)% and (50.9±0.9)%, respectively, also showing a significant difference (P<0.001). However, no significant changes in the expression of IFN-γ and membrane PD-L1 were found in the co-culture system composed of T cells and A549 cells. Conclusions: Anti-PD-L1 monoclonal antibody combined with EGFR-TKI can effectively promote the proliferation and secretion function of T lymphocytes in the microenvironment of EGFR-mutated lung cancer cells.

Biofilm, ice recrystallization inhibition and freeze-thaw protection in an epiphyte community.

Microbial communities found on the surface of overwintering plants may be exposed to low temperatures as well as multiple freeze-thaw events. To explore the adaptive mechanisms of these epiphytes, with the objective of identifying products for freeze-protection, enrichment libraries were made from frost-exposed leaves. Of 15 identified bacteria from 60 individual clones, approximately half had ice-association activities, with the great majority showing high freeze-thaw resistance. Isolates with ice nucleation activity and ice recrystallization inhibition activity were recovered. Of the latter, two (Erwinia billingiae J10, and Sphingobacterium kitahiroshimense Y2) showed culture and electron microscopic evidence of motility and/or biofilm production. Mass spectrometric characterization of the E. billingiae extracellular polymeric substance (EPS) identified the major proteins as 35 kDa outer membrane protein A and F, supporting its biofilm character. The addition of the EPS preparation increased the freeze-thaw survival of the more susceptible bacteria 1000-10000 times, and protection was at least partially dependent on the protein component.

Isolation and characterization of virulent bacteriophages against Escherichia coli serogroups O1, O2, and O78.

The goal of this study was to isolate and characterize a more complete set of phages that are active against Escherichia coli serogroups O1, O2, and O78, the main causative agents of avian colibacillosis. A mixture of E. coli (O1:K1), (O2:K1), and (O78:K80) was used as a host to isolate phages from wastewater and fecal samples from poultry processing plants. Seven phages were isolated; only 2 of them, EC-Nid1 and EC-Nid2, were selected for further characterization. It was found that EC-Nid1 and EC-Nid2 had icosahedral heads, necks, and contractile tails with tail fibers and therefore belonged to Myoviridae. The phages had genome sizes of 67.06 to 68.04 kb and they lysed all tested strains of E. coli serotype O1, O2, and O78. The 2 phages were resistant to pH 5 to 9, and phage EC-Nid2 was slightly more resistant to acid and alkali environments. Two major protein bands were indicated in EC-Nid (A and D); band D at 45 kDa was a major coat protein and band A was identified as a homolog of endo-N-acetylneuraminidase. It was concluded that phage EC-Nid1 and EC-Nid2 are highly active against O1, O2, and O78 colibacillosis strains.

Design of water gas shift catalysts for hydrogen production in fuel processors.

Low sulfur hydrocarbon fuels can be converted to fuel cell grade H(2) using a compact fuel processor architecture. The necessary high volumetric activity water gas shift (WGS) Pt on ceria-zirconia catalysts reacts CO-rich reformate with steam to yield H(2) and CO(2). Such highly selective, non-pyrophoric noble metal/Ce([1-(x+y)])Zr(x)Dp(y)O(2) catalysts were developed through coordinated atomic modeling, syntheses, structural characterization, kinetic performance tests, and micro-kinetic analyses. Density functional simulations made with the VASP code suggested that the undoped catalyst WGS activity would be limited by the strong binding of CO intermediates, blocking the reoxidation of the reduced oxide by water. These predictions were confirmed by in situ cylindrical internal reflection-Fourier transform infrared spectroscopy and by micro-kinetic analyses of the micro-reactor results. Atomic simulations were used to evaluate the impact transition metal dopants had on the surface chemistry of cubic ceria-zirconia. VASP predicted that acidic transition metal dopants such as Nb, Mo, Ta, and W would increase the oxide surface affinity for water and thus increase the turnover rate of the catalyst. The efficacy of Mo-doped ceria-zirconia compositions was confirmed at lower temperatures in replicated catalyst synthesis-reactor studies.

[Microbiological and production characteristics of the high-temperature Kongdian bed revealed during field trial of biotechnology for the enhancement of oil recovery].

Microbiological technology for the enhancement of oil recovery based on the activation of the stratal microflora was tested in the high-temperature horizons of the Kongdian bed (60 degrees C) of the Dagang oil field (China). This biotechnology consists in the pumping of a water-air mixture and nitrogen and phosphorus mineral salts into the oil stratum through injection wells in order to stimulate the activity of the stratal microflora which produce oil-releasing metabolites. Monitoring of the physicochemical, microbiological, and production characteristics of the test site has revealed large changes in the ecosystem as a result of the application of biotechnology. The cell numbers of thermophilic hydrocarbon-oxidizing, fermentative, sulfate-reducing, and methanogenic microorganisms increased 10-10 000-fold. The rates of methanogenesis and sulfate reduction increased in the near-bottom zone of the injection wells and of some production wells. The microbial oil transformation was accompanied by the accumulation of bicarbonate ions, volatile fatty acids, and biosurfactants in the formation waters, as well as of CH4 and CO2 both in the gas phase and in the oil. Microbial metabolites promoted the additional recovery of oil. As a result of the application of biotechnology, the water content in the production liquid from the test site decreased, and the oil content increased. This allowed the recovery of more than 14000 tons of additional oil over 3.5 years.

[Microbiological investigations of high-temperature horizons of the Kongdian petroleum reservoir in connection with field trial of a biotechnology for enhancement of oil recovery].

The physicochemical conditions and microbiological characteristics of the formation waters of the Kongdian bed of the Dagang oil field (China) were studied. It was demonstrated that this bed is a high-temperature ecosystem with formation waters characterized by low mineralization. The concentrations of nitrogen and phosphorus compounds, as well as of electron acceptors, are low. Oil and oil gas are the main organic matter sources. The bed is exploited with water-flooding. The oil stratum was inhabited mostly by anaerobic thermophilic microorganisms, including fermentative (10(2)-10(5) cells/ml), sulfate-reducing (0-10(2) cells/ml), and methanogenic (0-10(3) cells/ml) microorganisms. Aerobic bacteria were detected mainly in the near-bottom zone of injection wells. The rate of sulfate reduction varied from 0.002 to 18.940 microg S(2-) l(-1) day(-1) and the rate of methanogenesis from 0.012 to 16.235 microg CH4 l(-1) day(-1). Microorganisms with great biotechnological potential inhabited the bed. Aerobic thermophilic bacteria were capable of oxidizing oil with the formation of biomass, the products of partial oxidation of oil (volatile acids), and surfactants. During growth on the culture liquid of oiloxidizing bacteria, methanogenic communities produced methane and carbon dioxide, which also had oil-releasing capabilities. Using various labeled tracers, the primary filtration flows of injected solutions at the testing site were studied. Our comprehensive investigations allowed us to conclude that the tested method for microbial enhancement of oil recovery based on the activation of the stratal microflora can be applied in the Kongdian bed horizons.

Association of a Virus with Wheat Displaying Yellow Head Disease Symptoms in the Great Plains.

Wheat with yellow head disease (YHD) (yellow heads and mosaic leaf symptoms) has been observed in Kansas since 1997. A pathogen was transmitted from the infected wheat to maize by vascular puncture inoculation and to Nicotiana benthamiana by rub inoculation. The original infected wheat and infected maize and N. benthamiana test plants all produced a unique 32- to 34-kDa protein when analyzed by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). Time-of-flight mass spectrometry analysis of the unique 32- to 34-kDa protein showed that the amino acid sequence was most closely related to the nucleoprotein of Rice hoja blanca virus, indicating that the virus causing YHD symptoms in wheat is a tenuivirus. Antiserum made to this protein failed to react with extracts made from healthy wheat or wheat infected with Wheat streak mosaic virus or the High Plains virus. The antiserum did react to extracts made from symptomatic wheat, maize, and N. benthamiana, shown by SDS-PAGE to contain the unique protein, and to extracts of wheat with YHD symptoms from Kansas, North Dakota, South Dakota, and Oklahoma. The name Wheat yellow head virus is proposed for this virus.