[Evaluation of the efficacy and safety of Nocardia rubra cell wall skeleton immunotherapy for cervical high-risk HPV persistent infection]

Objective: To evaluate the efficacy and safety of Nocardia rubra cell wall skeleton (Nr-CWS) in the treatment of persistent cervical high-risk human papillomavirus (HR-HPV) infection. Methods: A randomized, double blind, multi-center trial was conducted. A total of 688 patients with clinically and pathologically confirmed HR-HPV infection of the cervix diagnosed in 13 hispital nationwide were recruited and divided into: (1) patients with simple HR-HPV infection lasting for 12 months or more; (2) patients with cervical intraepithelial neoplasia (CIN) Ⅰ and HR-HPV infection lasting for 12 months or more; (3) patients with the same HR-HPV subtype with no CINⅡ and more lesions after treatment with CINⅡ or CIN Ⅲ (CINⅡ/CIN Ⅲ). All participants were randomly divided into the test group and the control group at a ratio of 2∶1. The test group was locally treated with Nr-CWS freeze-dried powder and the control group was treated with freeze-dried powder without Nr-CWS. The efficacy and negative conversion rate of various subtypes of HR-HPV were evaluated at 1, 4, 8, and 12 months after treatment. The safety indicators of initial diagnosis and treatment were observed. Results: (1) This study included 555 patients with HR-HPV infection in the cervix (included 368 in the test group and 187 in the control group), with an age of (44.1±10.0) years. The baseline characteristics of the two groups of subjects, including age, proportion of Han people, weight, composition of HR-HPV subtypes, and proportion of each subgroup, were compared with no statistically significant differences (all P>0.05). (2) After 12 months of treatment, the effective rates of the test group and the control group were 91.0% (335/368) and 44.9% (84/187), respectively. The difference between the two groups was statistically significant (χ²=142.520, P<0.001). After 12 months of treatment, the negative conversion rates of HPV 16, 18, 52, and 58 infection in the test group were 79.2% (84/106), 73.3% (22/30), 83.1% (54/65), and 77.4% (48/62), respectively. The control group were 21.6% (11/51), 1/9, 35.1% (13/37), and 20.0% (8/40), respectively. The differences between the two groups were statistically significant (all P<0.001). (3) There were no statistically significant differences in vital signs (body weight, body temperature, respiration, pulse rate, systolic blood pressure, diastolic blood pressure, etc.) and laboratory routine indicators (blood cell analysis, urine routine examination) between the test group and the control group before treatment and at 1, 4, 8, and 12 months after treatment (all P>0.05); there was no statistically significant difference in the incidence of adverse reactions related to the investigational drug between the two groups of subjects [8.7% (32/368) vs 8.0% (15/187), respectively; χ²=0.073, P=0.787]. Conclusion: External use of Nr-CWS has good efficacy and safety in the treatment of high-risk HPV persistent infection in the cervix.

[Antimicrobial resistance and plasmid-mediated colistin resistance mechanism of diarrheagenic Escherichia coli recovered from foods in parts of China in 2020]

Objective: To investigate the antimicrobial resistance of food-borne diarrheagenic Escherichia coli (DEC) and the prevalence of mcr genes that mediates mobile colistin resistance in parts of China, 2020. Methods: For 91 DEC isolates recovered from food sources collected from Fujian province, Hebei province, Inner Mongolia Autonomous Region and Shanghai city in 2020, Vitek2 Compact biochemical identification and antimicrobial susceptibility testing platform was used for the detection of antimicrobial susceptibility testing (AST) against to 18 kinds of antimicrobial compounds belonging to 9 categories, and multi-polymerase chain reaction (mPCR) was used to detect the mcr-1-mcr-9 genes, then a further AST, whole genome sequencing (WGS) and bioinformatics analysis were platformed for these DEC isolates which were PCR positive for mcr genes. Results: Seventy in 91 isolates showed different antimicrobial resistance levels to the drugs tested with a resistance rate of 76.92%. The isolates showed the highest antimicrobial resistance rates to ampicillin (69.23%, 63/91) and trimethoprim-sulfamethoxazole (59.34%, 54/91), respectively. The multiple drug-resistant rate was 47.25% (43/91). Two mcr-1 gene and ESBL (extended-spectrum beta-lactamase) positive EAEC (enteroaggregative Escherichia coli) strains were detected. One of them was identified as serotype of O11:H6, which showed a resistance profile to 25 tested drugs referring to 10 classes, and 38 drug resistance genes were predicted by genome analysis. The other one was O16:H48 serotype, which was resistant to 21 tested drugs belonging to 7 classes and carried a new variant of mcr-1 gene (mcr-1.35). Conclusion: An overall high-level antimicrobial resistance was found among foodborne DEC isolates recovered from parts of China in 2020, and so was the MDR (multi-drug resistance) condition. MDR strains carrying multiple resistance genes such as mcr-1 gene were detected, and a new variant of mcr-1 gene was also found. It is necessary to continue with a dynamic monitoring on DEC contamination and an ongoing research into antimicrobial resistance mechanisms.

[Clinicopathological features and diagnosis of pericytic tumors of the kidney]

Objective: To investigate the clinicopathologic features,diagnosis and prognosis of pericytic tumor of the kidney. Methods: Three cases of pericytic tumor of the kidney (two cases were diagnosed as glomangiomyomas and one case as pericytic tumor,unclassified) were collected from the affiliated Hospital of Qingdao University between January 2014 to May 2021; the clinical and morphologic features, immunohistochemical and molecular characteristics were analyzed and the relevant literature was reviewed. Results: The three patients included one male and two females, with ages ranging from 21 to 70 years. In two patients the tumors were detected incidentally at physical examination and one patient presented with low back discomfort. Imaging showed a rounded nodular soft tissue density shadow in renal parenchyma, and enhancement scan showed uneven delayed enhancement. Grossly, two tumors were located in the renal hilum and one in the renal parenchyma; all were nodular. The tumors were measured in size from 1.6 cm to 5.1 cm (mean 4.1 cm) and showed gray or gray-red cut surface. Histologic examination showed the tumor cells were arranged in solid sheets or small nodules, closely related to vascular wall. Tumor cells were mostly epithelial-like with abundant cytoplasm, light eosinophilia, obscure boundary and round nuclei with visible nucleoli. Vague bundles and fascicular arrangements of smooth muscle component were noted in some areas, with transition of both components. There was no necrosis. By immunohistochemistry, the tumor cells strongly and diffusely expressed vimentin, SMA and collagen Ⅳ, two cases expressed CD34, all three cases expressed PDGFRB to varying extent, and the Ki-67 index was 2%-3%. PCR tests showed absent K-RAS, BRAF V600E gene mutation in all three cases. PDGFRB mutations in exons 3 and 18, respectively were found in two of the three cases by high-throughput sequencing, and no NOTCH 1/2/3 gene fusions were found in any of them. Follow-up information (range: 6-92 months) showed no evidence of local recurrence or distant metastasis in all three patients. Conclusions: Pericytic tumor of the kidney is a rare mesenchymal tumor originating in the kidney with differentiation to smooth muscle, most commonly glomus tumor. The mild pleomorphism, close relationship with vascular wall and spindled smooth muscle components suggest the diagnosis of the tumor. Expression of both epithelial and muscle-associated markers aids the diagnosis. PDGFRB gene mutations may have an important role in the development of this tumor. Most patients have a good prognosis, and a few cases have malignant biological behavior.

[Phenotypic and genomic characterization for Salmonella isolates recovered from meat products in Beijing wholesale markets, 2014-2015]

Objective: To analyze the phenotypic and genomic characteristics of Salmonella isolates recovered from meat products in Beijing wholesale markets. Methods: A total of 336 Salmonella strains from meat products collected from wholesale markets in Beijing were tested for antimicrobial resistance to 25 antimicrobial compounds by micro-broth dilution method; whole genome data were sequenced, followed by the serotype and ST type prediction by Seqsero2 and SISTR software, and the drug resistance genes and virulence factors were also predicted with CARD and VFDB databases of Abricate software; Salmonella serotyping assay kit and serum agglutination method were used for serotype confirmation of some isolates with different genome prediction results. Results: The resistance rates to Nalidixic acid and Ampicillin were 62.5% (210/336) and 55.1% (185/336), respectively, and all isolates were susceptible to Tigecyclin, Cefoxitin and Carbapenem antimicrobial compounds; 207 isolates (61.6%, 207/336) were multi-drug resistant, some could even be resistant to ten categories of drugs at the same time, and the most common antimicrobial resistance spectrum was NAL-AMP-SAM. A total of 24 serotypes were detected with predominant serotypes of Enteritidis (34.5%, 116/336), Derby (17.3%, 58/336) and Indiana (10.4%, 35/336). A total of 27 ST types were detected, the dominant type was ST11; ST types were in good consistency with serotypes; The detection rates of resistant genes referred to aminoglycosides, fluoroquinolones, β-lactams, sulfonamides and tetracyclines are more than 48%, and the first two reached 100%. The prediction of drug resistance genes was consistent with the results of antimicrobial resistance phenotype. A total of 122 virulence genes were predicted, 74 of which existing among all isolates. Conclusion: Salmonella in meat from the wholesale markets of Beijing has a high proportion of multiple drug resistance, a complex drug resistance spectrum, a variety of serotypes and ST types, and a high carrying rate of drug resistance gene and virulence gene; drug resistance phenotype and genotype are relatively consistent.

Monocarboxylate transporter 1-mediated lactate accumulation promotes nucleus pulposus degeneration under hypoxia in a 3D multilayered nucleus pulposus degeneration model

During intervertebral disc degeneration (IVDD), due to endplate calcification, diminished oxygen and nutrient concentrations and accumulated lactate are present in the microenvironment of the nucleus pulposus (NP). The disadvantages of 3D layered culture include uneven oxygen and nutrient gradients. In the present study, to mimic the in vivo microenvironment of the NP, a 5-layered 3D culture was constructed using clinical haemostatic gelatine sponges and developed as a NP degeneration (NPD) model. Subsequently, cell distribution as well as expression of NP chondrogenic markers (type II collagen and aggrecan), glycosaminoglycan (GAG) and degeneration markers [e.g. matrix metalloproteinase (MMP) 3] were measured from the top to the bottom layer. However, in a single NP-cell-loaded disc model, the chondrogenic potency in the middle or bottom layer was higher than that in the top layer. To further study the mechanism underlying the degeneration of NP cells in this NPD model, the contribution of secreted metabolites was examined. Lactate identified in the supernatant modulated GAG accumulation and MMP3 expression. Inhibition of lactate influx by the monocarboxylate transporter (MCT)-1 inhibitor, AZD3965, reversed the effect of lactate on GAG accumulation and MMP3 expression and further improved NP cell degeneration in the NPD model. Thanks to the homogenous expression of lactate in the model, it was possible to further identified that the combination of lactate and hypoxia enhanced MMP3 expression. Taken together, multilayered cell-loaded sponges, with oxygen and nutrient gradients as well as lactate accumulation, can represent a 3D multilayered NPD model for exploring potential agents for IVDD.

The impact of particulate matter air pollution (PM2.5) on atherosclerosis in modernizing China: a report from the CATHAY study

BACKGROUND

Air pollution has been associated with an increase in cardiovascular diseases incidence. To evaluate whether air pollution can accelerate atherogenic processes, we assessed the effects of air pollution on important surrogate markers of atherosclerosis [brachial flow-mediated dilation (FMD) and carotid intima-media thickness (IMT)].

METHODS

A total of 1656 Han Chinese (mean age 46.0 + 11.2 years; male 47%) in Hong Kong, Macau, Pun Yu, Yu County and the 3-Gorges Territories (Yangtze River) were studied between 1996 and 2007 [Chinese Atherosclerosis in the Aged and Young Project (the CATHAY Study)]. Cardiovascular risk profiles were evaluated. Particulate matter with an aerodynamic diameter <2.5 µm (PM2.5) parameters were computed from satellite sensors. Brachial FMD and carotid IMT were measured by ultrasound.

RESULTS

Health parameters [age, gender, body mass index, waist : hip ratio (WHR) and glucose)] were similar in lowest and highest PM2.5 exposure tertiles, systolic and diastolic blood pressures and triglycerides were higher (P < 0.001) and low-density cholesterol (LDL-C) was lower in the top PM2.5 tertile (P < 0.001). Brachial FMD [7.84 ± 1.77, 95% confidence interval (CI) 7.59-8.10%, vs 8.50 ± 2.52, 95% CI 8.23-8.77%, P < 0.0001) was significantly lower and carotid IMT (0.68 ± 0.13 mm, 95% CI 0.67-0.69 mm vs 0.63 mm ± 0.15 mm 95% CI 0.62-0.64 mm; P < 0.0001) was significantly thicker in the top PM2.5 tertile compared with the lowest tertile. On multiple regression, FMD was inversely related to PM2.5 (beta = 0.134, P = 0.015) independent of gender, age and blood pressure (model R2 = 0.156, F-value = 7.6, P < 0.0001). Carotid IMT was significantly correlated with PM2.5 exposure (beta = 0.381, P < 0.0001) independent of age, location, gender, WHR, blood pressure and LDL-C (model R2 = 0.408, F-value = 51.4, P-value <0.0001).

CONCLUSIONS

Air pollution is strongly associated with markers of early atherosclerosis, suggesting a potential target for preventive intervention.

The Expression of Recombinant Human Serum Albumin in the Mammary Gland of Transgenic Mice

Human serum albumin (HSA) is widely used in the clinic for the treatment of several diseases in large amount each year. With the increasing demands of HSA in clinic and limited blood resource, recombinant HSA (rHSA) is becoming an attractive and alternative source for HSA production. In this study, we aimed to express rHSA in the mammary glands of transgenic mice by using a tissue-specific promoter and other regulatory elements. An rHSA expression vector was constructed bearing the cDNA and first intron of HSA under the control of bovine αs1-casein promoter with a 2 × chicken β-globin insulator in the front. Transgenic mice were generated and reverse transcription polymerase chain reaction showed that rHSA was expressed only in the mammary gland, indicating the tissue specificity of the bovine αs1-casein promoter in directing transgene transcription in transgenic mice. Enzyme-linked immunosorbent assay test showed that rHSA was successfully secreted into the milk of transgenic mice with the highest level at 1.98 ± 0.12 g/L. Our results indicate the ability of the bovine αs1-casein promoter to induce successful expression of rHSA in the mammary gland of transgenic mice.

[Analysis on serotype and antimicrobial resistance of invasive non-typhoidal Salmonella]

Objective: To investigate the serotypes and antimicrobial resistance of seven invasive non-typhoidal Salmonella (iNTS) isolates. Methods: For 7 iNTS strains collected, serotype identification, antimicrobial susceptibility testing and whole genome sequencing were performed. We identified, annotated and analyzed the serotypes, MLST types, and antimicrobial resistance genes. Results: Among the 7 tested iNTS isolates, we found one Salmonella Typhimurium strain and two Salmonella Ⅰ 4, [5], 12: i:- strains whose MLST types were ST34, two Salmonella Enteritidis strains, one Salmonella Corvallis strain and one strain of unknown serotype with the antigenic formulae of Ⅰ 4, [5], 12: d:- (ST279 type). Six of seven strains were monophasic and the deletion or pseudogenization of Salmonella Flagellum gene might contribute to the enhancement of Salmonella invasiveness. None was found to be resistant to tigarcycline, aztreonam, amikacin, cephalosporins and carbapenem and one Salmonella Typhimurium strain was found to be co-resistant to eight classes of antimicrobials at the same time. Resistance genes were generally in accord with relative resistant phenotypes. Conclusion: The iNTS strains could show high level multi-drug resistance, indicating that close attention should be paid to the resistance of iNTS though the overall resistance might be relatively not high.

Detection of Hole Pockets in the Candidate Type-II Weyl Semimetal MoTe_{2} from Shubnikov-de Haas Quantum Oscillations

The bulk electronic structure of T_{d}-MoTe_{2} features large hole Fermi pockets at the Brillouin zone center (Γ) and two electron Fermi surfaces along the Γ-X direction. However, the large hole pockets, whose existence has important implications for the Weyl physics of T_{d}-MoTe_{2}, has never been conclusively detected in quantum oscillations. This raises doubt about the realizability of Majorana states in T_{d}-MoTe_{2}, because these exotic states rely on the existence of Weyl points, which originated from the same band structure predicted by density functional theory (DFT). Here, we report an unambiguous detection of these elusive hole pockets via Shubnikov-de Haas (SdH) quantum oscillations. At ambient pressure, the quantum oscillation frequencies for these pockets are 988 and 1513 T, when the magnetic field is applied along the c axis. The quasiparticle effective masses m^{*} associated with these frequencies are 1.50 and 2.77 m_{e}, respectively, indicating the importance of Coulomb interactions in this system. We further measure the SdH oscillations under pressure. At 13 kbar, we detected a peak at 1798 T with m^{*}=2.86m_{e}. Relative to the oscillation data at a lower pressure, the amplitude of this peak experienced an enhancement, which can be attributed to the reduced curvature of the hole pockets under pressure. Combining our experimental data with DFT+U calculations, where U is the Hubbard parameter, our results shed light on why these important hole pockets have not been detected until now.

[Differentiation of prostatitis and clinically significant prostate cancer in peripheral zone using the prostate imaging-reporting and data system]

Objective: To determine whether clinically significant prostate cancer (PCa) and prostatitis in the peripheral zone can be distinguished using prostate imaging reporting and data system version 1 (PI-RADS V1) and version 2(PI-RADS V2). Methods: Between September 2010 and August 2016, mpMRI data of 77 patients with PCa and 29 prostatitis obtained at 3.0 T were collected in Zhangjiagang Hospital Affiliated to Soochow University. Every lesion was scored according to PI-RADS (V1 and V2), as well as a sum score and a PI-RADS V2 score. The non-parametric Kruskal-Wallis test was used to assess differences between PCa and prostatitis regarding PS3, PS4 and PI-RADS V2 score. The diagnostic performance of PI-RADS V1 and V2 for detection of prostatitis in peripheral zone was compared by analyzing ROC curve. Results: The PI-RADS V1 score for PS3, PS4 and the PI-RADS V2-score were all significantly higher for PCa (PS3:12.1±2.1; PS4:16.2±2.9; V2:4.6±0.8) than for prostatitis (PS3:8.0±0.7; PS4:10.6±1.0; V2:3.0±0.5) (all P<0.01). Of these parameters, PS4 achieved the highest predictive value for the presence of prostatitis with an AUC of 0.937, sensitivity and specificity were 87.0%, 97.0% with a threshold of 12.5. Conclusion: Prostatitis can be differentiated from clinically significant PCa in peripheral zone on mpMRI using PI-RADS system, PS4 achieved better results compared to PS3 and V2.

Hypofractionated stereotactic radiotherapy combined with chemotherapy or not in the management of recurrent malignant gliomas: A systematic review and meta-analysis

Hypofractionated stereotactic radiotherapy (HFSRT) is a common salvage treatment for recurrent malignant glioma (MG). However, it remains controversial whether the combination of HFSRT and chemotherapy could improve survival for patients with recurrent MG compared to HFSRT alone. The present systematic review and meta-analysis aims to investigate this question, and tries to determine to what extent the addition of chemotherapy to HFSRT affects survival. A systematic review was performed to analyse the survival for patients treated with HFSRT combined with chemotherapy or not. Hazard ratios (HRs) with 95% confidence intervals (CIs) for overall survival (OS) were pooled with random effects; and standard mean difference (MD) with 95% CIs for OS were pooled using the same strategy. A total of 7 studies including 388 patients with recurrent MG were eligible for our study. The OS survival of patients receiving combination therapy ranged from 8.7 to 23 months, and the median OS of patients underwent HFSRT ranged from 3.9 to 12 months. The meta-analyses resulted in the pooled HR of 0.44 (95% CI 0.30-0.65, p < 0.0001) (Cochran Q statistic 4.70, P = 0.320, I² = 14.8%) and pooled standard MD of 0.80 months (95% CI 0.41-1.18, p < 0.001) (Cochran Q statistic 10.16, p = 0.71, I² = 50.8%). The present study suggests that HFSRT + chemotherapy confers a slight survival improvement for patients with recurrent MG as compared with sole HFSRT management. To draw a more solid conclusion, greater investigation is warranted.

Marsupialisation for the treatment of unicystic ameloblastoma of the mandible: a long-term follow up of 116 cases

Unicystic ameloblastoma is a unique histopathological type of ameloblastoma, and treatment is controversial. Marsupialisation is effective in reducing the size of cystic lesions and their complications. We have retrospectively analysed the clinical, histopathological, and prognostic data of affected patients who were treated by marsupialisation between 2003 and 2013 in three Chinese hospitals. Our aim was to evaluate the effects and prognosis, and the factors associated with outcome. A total of 116 patients with mandibular unicystic ameloblastomas were included, and 74, 26, and 16 patients were histopathologically classified as being luminal, intraluminal, and mural subtypes, respectively. Most responded well to marsupialisation, with an overall recurrence rate of 12%. Resorption of the root (p<0.001), perforation of the cortical bone (p=0.005), and histopathological subtype (p=0.013) were the main factors that predicted the outcome. Perforation of the cortical bone was the only reliable predictor of recurrence (p<0.001). Disease-free survival function curves indicated that patients with the mural subtype were at a higher risk of recurrence than patients with the other two subtypes (p=0.003). Poor outcomes of marsupialisation were treated surgically and, to date, no subsequent recurrences have been reported. Marsupialisation is effective for these patients, with a recurrence rate similar to that of radical treatment. The outcomes can be predicted using characteristics of the lesion such as resorption of the root, perforation of the cortical bone, and histopathological subtypes. However, additional studies are required to corroborate these findings.

[The reliability of using impenem, meropenem, cefoperazone-sulbactam and piperacillin-tazobactam to treat nosocomial Gram-negative bacterial infections with Monte Carlo simulation]

Objective: To evaluate the reliability of using imipenem, meropenem, cefoperazone-sulbactam, piperacillin-tazobactam in the treatment of hospital-acquired Gram-negative bacterial infections with Monte Carlo simulation(MCS). Methods: The MIC of the four agents collected from hospital-acquired infections were detected in accordance with broth dilution method of Clinical and Laboratory Standard Institute (CLSI). MCS were conducted with MICs and the pharmacokinetics parameters of the four agents based on conventional dose regimens.The cumulative fraction of response (CFR) of time over MIC target attainment in different dosing regimen were generated. Results: A total of 2 541 strains, including 2 093 strains of Enterobacteriaceae and 448 strains of glucose non-fermentative bacilli were collected.The MIC(90) of imipenem and meropenem against Enterobacteriaceae were less than 1 mg/L in general, whereas MIC(90) of two agents with β-lactamase inhibitors was around 64 mg/L.As to glucose non-fermenting bacteria, MICs of all the four agents were very high, especially to Acinetobacter baumannii, which indicated MIC(50) more than 32 mg/L.MCS revealed that carbapenems had significantly higher CFR than those with β-lactamase inhibitors.Imipenem and meropenem (1 g, q8 h) obtained CFRs of 74.69% and 81.42%, respectively.The CFR of cefoperazone-sulbactam (2 g, q8 h) and piperacillin-tazobactam (4 g, q6 h) (both excluding β-lactamase inhibitors) were just 49.59% and 27.66% respectively, which increased after excluding A. baumannii in piperacillin-tazobactam. Conclusions: The conventional dose regimens of imipenem and meropenem are reliable for the empiric therapy of Gram-negative hospital-acquired bacterial infections.Piperacillin-tazobactam is suggested to use with higher doses or prolonged infusion time to satisfy the time of drug concentration exceeded the MIC(T>MIC)requirement.More clinical studies of cefoperazone-sulbactam should be conducted to optimize its regimen and guarantee its efficacy.

[Advances on antimicrobial resistance research of Salmonella enterica Serovar Indiana]

Salmonella enterica Serovar Indiana is a common serotype of Salmonella isolated from food especially from poultry meat. Recently it demonstrated a raising tendency of infection cases and isolate numbers with high antimicrobial resistant rate against many common antimicrobials, including quinolones and cephalosporin which were regarded as the first line drug for the treatment of Salmonella infections, and this kind of Salmonella serotype was always carrying complex resistance mechanisms and also a variety of mobile elements, all of these features made the very clinical infections caused by Salmonella hard to treat and brought great difficulties and risks. Here, we review the prevalence of Samonella Indiana on national and international view, and we also anticipate the research progress on antimicrobial drug classes, multi drug resistance, co-resistance and resistance mechanism. We discuss the resistant genotypes, phenotypes, mechanism and transmission of Salmonella Indiana strains isolated from different origins. By introducing the resistance of Salmonella Indiana, we want to attract people's attention to this bacteria and its hazard, and offer some idea to evaluate and treat infections in clinical.

[Molecular typing characterization of food-borne methicillin-resistant Staphylococcus aureus in China]

Objective: To analyses the antimicrobial resistance and molecular characterization of 21 MRSA isolates cultured from retail foods from different provinces in China, and evaluate the molecular typing methods. Methods: Twenty-one MRSA isolates were obtained from national foodborne pathogen surveillance network in 2012 (Chinese salad, n=3; milk, n=1; cake, n=2; rice, n=1; cold noodle, n=1; spiced beef, n=1; dumpling, n=1; packed meal, n=1; salad, n=1; raw pork, n=9). The antimicrobial resistance of 21 strains to 12 antimicrobial agents was tested by broth dilution method. Polymerase chain reaction (PCR) and DNA sequencing were performed to obtain the genetic types of MLST (ST) and spa typing. The clonal complex (CC) was assigned by eBURST soft and the MLVA type (MT) and MLVA complex (MC) were identified via the database of the MLVA website (http://www.mlva.net). SmaI pulsed-field gel electrophoresis (SmaⅠ-PFGE) was also carried out to obtain the PFGE patterns of 21 strains. The genetic diversity and discriminatory power of typing were calculated by the Simpson's index of diversity (diversity index, DI) to find out the best genotyping method for MRSA. Results: All MRSA isolates showed multi-drug resistance(MDR), and were resistant to oxacillin, benzylpenicillin, clindamycin and erythromycin, and 71.4% (15/21), 47.6% (10/21), 42.9% (9/21) and 28.6% (6/21) of the MRSA isolates were resistant to tetracycline, ciprofloxacin, trimethoprim/sulfamethoxazole and gentamicin, respectively. Moreover, one strain was found to be resistant to all three antimicrobials of levofloxacin, moxifloxacin and rifampicin. Great diversity was found in these food-associated MRSA (6 STs, 7 spa types, and 9 MTs). PFGE patterns were more diverse than those of other three molecular typing methods (19 pulse types). The index of diversity (DI) of PFGE, MLVA, spa typing and MLST was 0.99, 0.80, 0.73, and 0.61, respectively. Among the MRSA isolates, CC9-ST9-t899-MT929-MC2236 (PFGE Cluster Ⅴ) was the most prevalent clone, which were all cultured from raw pork (9 isolates). Besides, two MRSA were identified as CC59-ST338-t437-MT621-MC621 (PFGE Cluster Ⅳ). Different clone had their own resistance spectrum profiles. Conclusion: The food-borne MRSA isolates were all MDR in this study. Different clones had their own resistance spectrum profiles. MLVA represented a promising tool for molecular epidemiology tracing of MRSA in foodborne disease events.

[Serotype distribution and antimicrobial resistance of Salmonella isolates from retail chicken carcasses in six provinces of China]

Objective: To obtain the serotype diversity and antimicrobial resistance of Salmonella isolates recovered from retail chicken carcasses for sale in six regions of China. Methods: From August 2010 to March 2012, each month 20 retail chicken carcasses including freshly slaughtered, chilled and frozen samples were collected from supermarkets and farmer's markets in 7 monitoring sites in Beijing, Jilin province, Inner Mongolia Autonomous, Shanxi province, Jiangsu province and Guangdong province, respectively. Samples were routinely collected for 12 months for each site. 1 680 chicken carcasses were collected in total and 2 629 Salmonella strains were isolated by PCR and biochemical method. Luminex xMAP method and classical slide agglutination method were carried out to determine isolates' serotypes. Minimal inhibitory concentrations (MICs) of 10 classes of antimicrobials including 14 agents were determined using broth micro-dilution method. Mocular methods were used to determine antimicrobial resistance genes of CIP-CTX-CT co-resistant isolates. Results: In all, 2 629 Salmonella isolates, there were 17 seorgroups and 58 serotypes, B and D1 were the dominant serogroups with rates of 34.7% (n=913) and 31.0% (n=815), Enteritidis (30.8%, n=810), Indiana (17.6%, n=463), Infantis (10.6%, n=278) were the top three serovars. We found 224 CIP-CTX co-resistant S. Indiana containing 3 colistin resistant strains, one of them carrying mcr-1 gene and being ESBLs positive, which demonstrated a nine multi drug resistance against 11 antimicrobials tested. Conclusion: These data began to describe the complicated serovar diversity and heavy antimicrobial resistance of Salmonella isolates recovered from retail chicken carcasses in six regions of China. The findings highlight the emergence of ciprofloxacin and cefotaxime co-resistant S. Indiana and also a mcr-1 positive S. Indiana with heavy multi drug resistance.

[Inhibition of G9a attenuates cell proliferation via the mitochondrial apoptosis pathway in lung adenocarcinoma]

Objective: The aim of this study is to investigate the effect of G9a inhibitor BIX-01294 on attenuating cell proliferation in human lung adenocarcinoma A549 cell line and the underlying molecular mechanism. Methods: Treated with BIX-01294, the growth and proliferation of A549 cells were detected by MTT assay and colony formation assay, and its impact on cell apoptosis was analyzed using flow cytometry. By Western blot, we explored the alterations in the expression of apoptosis-related proteins and the G9a catalysate, H3K9me and H3K9me2. In addition, in the pretreatment with caspase inhibitor Z-VAD-FMK, we detected the apoptotic dependence of BIX-01294 attenuating impact on A549 cell proliferation. Results: Compared with the control group, the histone methyltransferase G9a inhibitor BIX-01294 attenuated cell proliferation in A549 cells in a dose- and time-dependent manner. There were 42.5±8.7 colonies after BIX-01294 (10 μmol/L) treatment for 7 days, while 172.7±23.0 colonies in the control group, with a statistical significance (P<0.05). After treatment with BIX-01294 (10 μmol/L) for 24 hours, the cell apoptotic rate was(47.6±8.4)%, with a significant difference in comparison with the control group [(7.2±3.6)%, P<0.05]. The expression of G9a catalysate, H3K9me and H3K9me2 was downregulated, the same with anti-apoptotic protein Bcl-2, while the proteins in mitochondrial apoptosis pathway, Bax, Bak and cleaved caspase-9, were upregulated, so was the expression of cleaved caspase-3 and cleaved PARP, and there was no alteration in the expression of cleaved caspase-8, which is a protein related with death receptor apoptosis pathway. Furthermore, after Z-VAD-FMK pretreatment, the cell apoptotic rate was decreased significantly, and the expression of apoptosis-related proteins were downregulated. Conclusions: Our results indicate that BIX-01294 can attenuate cell proliferation in lung adenocarcinoma, and it can be considered as one of the underlying mechanisms, the apoptosis may be induced by activating mitochondrial pathway.

[Effects of recombinant human growth hormone on local expression of insulin-like growth factor-Ⅰ during orthodontic tooth movement]

OBJECTIVE

To explore in vivo the expression of insulin-like growth factor-Ⅰ(IGF-Ⅰ)under stress, and to analyze changes of the local expression related to recombinant human growth hormone(rhGH)treatment.

METHODS

Forty Wistar rats were randomly divided into control and growth hormone groups, 20 in each group. A force of 0.49 N was applied to move the right upper first molars mesially. The growth hormone group and control group received daily subcutaneous injections of rhGH and equivalent volumes of saline, respectively. The rats were sacrificed on days 1, 3, 7 and 14. Micro-CT-reconstructed images were used to survey root resorption, and horizontal sections of the maxillae were prepared for tartrate-resistant acid phosphate(TRAP)and immunohistochemistry staining.

RESULTS

Tooth moved faster in the growth hormone group([0.291±0.017], [0.513±0.111]mm)than in the control group([0.245±0.033], [0.368± 0.052]mm)on days 7 and 14(P<0.05). More osteoclasts on day 3, and fewer osteoclasts on day 7 were observed in the growth hormone group([4.0±0.7], [2.6±0.6]cell/high-power field)than in the control group([2.8±0.6], [3.8±0.8]cell/high-power field)(P<0.05). The number of IGF-Ⅰ positive osteoclasts in the growth hormone group([4.7 ± 0.7]cell/high-power field)was significantly greater than that in the control group([2.7±0.5]cell/high-power field)(P<0.01)on day 3. Compared with the control group([18.6±1.5], [23.3± 3.8]cell/high-power field), IGF-Ⅰ positive PDL cells increased on days 7 and 14 in the growth hormone groups([29.6±3.4], [37.5±6.1]cell/high-power field)(P<0.01).

CONCLUSIONS

rhGH could stimulate IGF-Ⅰ expression in PDL, and accelerate bone remodeling and tooth movement.

Effects of corn distillers dried grains with solubles on performance, oxidative status, intestinal immunity and meat quality of Chinese Yellow broilers

The study assessed the effects of different dietary levels of corn distillers dried grains with solubles (DDGS) on performance, oxidation status, intestinal immunity and meat quality in Chinese Yellow broilers aged from 1 to 63 days. Lingnan male hatchings (1440) were randomly assigned to six treatments, each consisting of six replicates of 40 birds. The basal diet (I) was a typical corn-soya bean ration while the experimental diets (II to VI) partially substituted corn DDGS for soya bean meal. The level of substitution in starter, grower and finisher diets was as follows: II, 2%, 4% then 6%; III, 4%, 8% then 12%; IV, 6%, 12% then 18%; V, 8%, 16% then 24%; VI, 10%, 20% then 30%. Average daily feed intake and feed-to-gain ratio increased as linear responses to corn DDGS substitution from 1 to 21 days (p < 0.001). The plasma content of triglycerides and liver content of malondialdehyde increased as linear responses to corn DDGS substitution (p < 0.05). There was a linear decrease (p < 0.001) in jejunal abundance of IL-6 transcripts, with a substantial reduction to approximately 25% those of broilers fed the control diet, and a quadratic effect existed for secretory immunoglobulin A (sIgA) (p < 0.001). In addition, increased dietary corn DDGS caused favourable changes in selected functional properties of the meat: drip loss at 24 and 96 h increased as linear response to corn DDGS substitution (p < 0.001). Further, meat colour L* values decreased and a* values increased linearly in response to increasing corn DDGS (p < 0.05). In conclusion, diet IV (6%, 12% then 18% corn DDGS) in Chinese Yellow broiler diets had no negative effects on performance, antioxidant capacity and meat quality. This level of inclusion also appeared to promote sIgA secretion and enhance anti-inflammatory status.

Mechanical force-induced specific MicroRNA expression in human periodontal ligament stem cells

It remains unclear how the expression of microRNAs (miRNAs) in human periodontal ligament stem cells (PDLSCs) might respond to mechanical stretch. To investigate specific miRNA expression in stretched PDLSCs, we used a Flexcell® FX-5000™ tension system to achieve external mechanical stimulation. Then, a custom-designed microarray assay was performed to investigate and describe the genome-wide differential expression of miRNAs in normal and stretched PDLSCs. Finally, we implemented integrative miRNA target prediction and network analysis approaches to construct an interaction network of the key miRNAs and their putative targets. We found that stretching induced morphological changes and increased alkaline phosphatase (ALP) activity, runt-related transcription factor 2 (RUNX2), osteocalcin (OCN), and bone sialoprotein (BSP) expression in PDLSCs. The microarray data showed that 53 miRNAs were differentially expressed with stretching. With an interaction network, we examined the connections between 10 selected key miRNAs and their putative target genes, which were related to mechanical force. The results from the interaction network provided a basis for postulating the functional roles of miRNAs in PDLSCs.

A Likelihood-Based Framework for Association Analysis of Allele-Specific Copy Numbers

Copy number variants (CNVs) and single nucleotide polymorphisms (SNPs) co-exist throughout the human genome and jointly contribute to phenotypic variations. Thus, it is desirable to consider both types of variants, as characterized by allele-specific copy numbers (ASCNs), in association studies of complex human diseases. Current SNP genotyping technologies capture the CNV and SNP information simultaneously via fluorescent intensity measurements. The common practice of calling ASCNs from the intensity measurements and then using the ASCN calls in downstream association analysis has important limitations. First, the association tests are prone to false-positive findings when differential measurement errors between cases and controls arise from differences in DNA quality or handling. Second, the uncertainties in the ASCN calls are ignored. We present a general framework for the integrated analysis of CNVs and SNPs, including the analysis of total copy numbers as a special case. Our approach combines the ASCN calling and the association analysis into a single step while allowing for differential measurement errors. We construct likelihood functions that properly account for case-control sampling and measurement errors. We establish the asymptotic properties of the maximum likelihood estimators and develop EM algorithms to implement the corresponding inference procedures. The advantages of the proposed methods over the existing ones are demonstrated through realistic simulation studies and an application to a genome-wide association study of schizophrenia. Extensions to next-generation sequencing data are discussed.

Development of a quantitative ELISA kit for human secreted CD306/LAIR-2 and its application

AIM

A quantitative ELISA kit for the detection of human secreted CD306/LAIR-2 was developed using monoclonal and polyclonal antibodies which were raised against a highly purified recombinant human secreted CD306/LAIR-2.

METHODS

Anti-human secreted CD306/LAIR-2 monoclonal and polyclonal antibodies were raised by immunizing mouse or rabbit with recombinant human secreted CD306/LAIR-2. The monoclonal antibody was purified by protein G affinity, whereas the polyclonal antibody was purified by protein A affinity. The best match pair of antibodies were found and used to develop a double antibody sandwich ELISA kit for the detection of human secreted CD306/LAIR-2 in human samples.

RESULTS

A human secreted CD306/LAIR-2 ELISA kit was formulated with highly purified recombinant human secreted CD306/LAIR-2, highly specific monoclonal and polyclonal antibodies. This kit realized the quantitative measurement of recombinant human CD306/LAIR-2 and natural CD306/LAIR-2 in human serum samples.

CONCLUSIONS

The developed human secreted CD306/LAIR-2 ELISA kit is a reliable quantitation immunoassay kit.

Fractional iron solubility of aerosol particles enhanced by biomass burning and ship emission in Shanghai, East China

In terms of understanding Fe mobilization from aerosol particles in East China, the PM2.5 particles were collected in spring at Shanghai. Combined with the backtrajectory analysis, the PM2.5/PM10 and Ca/Al ratios, a serious dust-storm episode (DSE) during the sampling was identified. The single-particle analysis showed that the major iron-bearing class is the aluminosilicate dust during DSE, while the Fe-bearing aerosols are dominated by coal fly ash, followed by a minority of iron oxides during the non-dust storm days (NDS). Chemical analyses of samples showed that the fractional Fe solubility (%FeS) is much higher during NDS than that during DSE, and a strong inverse relationship of R(2)=0.967 between %FeS and total atmospheric iron loading were found, suggested that total Fe (FeT) is not controlling soluble Fe (FeS) during the sampling. Furthermore, no relationship between FeS and any of acidic species was established, suggesting that acidic process on aerosol surfaces are not involved in the trend of iron solubility. It was thus proposed that the source-dependent composition of aerosol particles is a primary determinant for %FeS. Specially, the Al/Fe ratio is poorly correlated (R(2)=0.113) with %FeS, while the apparent relationship between %FeS and the calculated KBB(+)/Fe ratio (R(2)=0.888) and the V/Fe ratio (R(2)=0.736) were observed, reflecting that %FeS could be controlled by both biomass burning and oil ash from ship emission, rather than mineral particles and coal fly ash, although the latter two are the main contributors to the atmospheric Fe loading during the sampling. Such information can be useful improving our understanding on iron solubility on East China, which may further correlate with iron bioavailability to the ocean, as well as human health effects associated with exposure to fine Fe-rich particles in densely populated metropolis in China.

[Research progress on strain improvement of Acremonium chrysogenum by genetic engineering]

Acremonium chrysogenum, cephalosporin C (CPC) producing strain, is an important industrial microorganism. CPC is used to produce 7-ACA, a major intermediate for manufacturing of many first-line anti-infectious cephalosporin-antibiotics. The fermentation level of CPC determines the production, quality and cost of its downstream products. Therefore, it is necessary to develop the strains of A. chrysogenum. Along with the development of molecular biology, genetic manipulation technique is becoming more and more important in the field of molecular breeding. This paper reviews the latest research progresses on CPC biosynthesis and its regulation. Genetic manipulations of A. chrysogenum were summarized and concluded. We suggested that strain improvement of A. chrysogenum by means of induction and expression of biosynthetic and regulatory genes, as well as exogenous genes, and further optimization could be applied to different aspects including CPC production enhancement and metabolic pathway elongation, etc. Future direction of this field is also proposed. We believed that incorporation of comparative proteomics and genomic shuffling with molecular breeding could lead the achievements close to industry promptly.

Twenty-four weeks of pegylated interferon plus ribavirin effectively treat patients with HCV genotype 6a

The optimal duration of treatment and expected response rate for hepatitis C virus genotype (HCV-6)-infected patients have not been determined. Our aims were to determine the treatment outcome with pegylated interferon (PEG-IFN) plus ribavirin for HCV-6a-infected patients at Southwest Hospital and assess the association of the on-treatment virological response with the sustained virological response (SVR). Medical records were reviewed retrospectively. Twenty-two HCV-6a-infected patients were treated for 24 weeks, and 21 (95.5%) achieved an early virological response (EVR), 20 (90.9%) an end-of-treatment response (ETR) and 18 (81.8%) a SVR. However, only 18 of the 22 HCV-6a-infected patients were tested for serum HCV RNA level at week 4 of treatment and 15 (83.3%) achieved a rapid virological response (RVR). The rates of SVR, RVR, EVR and ETR in these patients were all similar to those in HCV-2/3 treated for 24 weeks and higher than those in HCV-1b-infected patients treated for 48 weeks. A lower relapse rate (10.0%) was seen in HCV-6a compared with HCV-2/3 (12.5%) or HCV-1b-infected patients (23.3%). The positive predictive values of RVR and EVR for HCV-6a were comparable with those for HCV-2/3-infected patients (86.7%vs 90.9%, P = 0.683 and 85.7%vs 86.8%, P = 0.904, respectively). Of the 3 HCV-6a-infected patients who did not achieve a RVR, 2 achieved an EVR and went on to achieve a SVR. The patient who did not achieve an EVR did not achieve a SVR. In summary, our results indicate that 24 weeks of PEG-IFN plus ribavirin can effectively treat patients with HCV-6a chronic infection.

Analysis of untyped SNPs: maximum likelihood and imputation methods

Analysis of untyped single nucleotide polymorphisms (SNPs) can facilitate the localization of disease-causing variants and permit meta-analysis of association studies with different genotyping platforms. We present two approaches for using the linkage disequilibrium structure of an external reference panel to infer the unknown value of an untyped SNP from the observed genotypes of typed SNPs. The maximum-likelihood approach integrates the prediction of untyped genotypes and estimation of association parameters into a single framework and yields consistent and efficient estimators of genetic effects and gene-environment interactions with proper variance estimators. The imputation approach is a two-stage strategy, which first imputes the untyped genotypes by either the most likely genotypes or the expected genotype counts and then uses the imputed values in a downstream association analysis. The latter approach has proper control of type I error in single-SNP tests with possible covariate adjustments even when the reference panel is misspecified; however, type I error may not be properly controlled in testing multiple-SNP effects or gene-environment interactions. In general, imputation yields biased estimators of genetic effects and gene-environment interactions, and the variances are underestimated. We conduct extensive simulation studies to compare the bias, type I error, power, and confidence interval coverage between the maximum likelihood and imputation approaches in the analysis of single-SNP effects, multiple-SNP effects, and gene-environment interactions under cross-sectional and case-control designs. In addition, we provide an illustration with genome-wide data from the Wellcome Trust Case-Control Consortium (WTCCC) [2007].

Clinical presentations and imaging findings of neuroblastoma beyond abdominal mass and a review of imaging algorithm

Neuroblastoma is one of the most common malignant neoplasms in childhood. The most common clinical presentation of this tumour is abdominal mass. However, affected children may have various clinical presentations as a result of disseminated metastatic disease or associated paraneoplastic syndromes at the time of diagnosis. In this article we have outlined the imaging findings in seven patients with "extra-abdominal" presentation of neuroblastoma and the pitfalls in making the correct diagnosis. The purpose of this pictorial review is to alert the general radiologist to the possible presentations of this common childhood malignancy to derive early detection and diagnosis.

A general framework for studying genetic effects and gene-environment interactions with missing data

Missing data arise in genetic association studies when genotypes are unknown or when haplotypes are of direct interest. We provide a general likelihood-based framework for making inference on genetic effects and gene-environment interactions with such missing data. We allow genetic and environmental variables to be correlated while leaving the distribution of environmental variables completely unspecified. We consider 3 major study designs-cross-sectional, case-control, and cohort designs-and construct appropriate likelihood functions for all common phenotypes (e.g. case-control status, quantitative traits, and potentially censored ages at onset of disease). The likelihood functions involve both finite- and infinite-dimensional parameters. The maximum likelihood estimators are shown to be consistent, asymptotically normal, and asymptotically efficient. Expectation-Maximization (EM) algorithms are developed to implement the corresponding inference procedures. Extensive simulation studies demonstrate that the proposed inferential and numerical methods perform well in practical settings. Illustration with a genome-wide association study of lung cancer is provided.

Reconstruction of a palatomaxillary defect with vascularized iliac bone combined with a superficial inferior epigastric artery flap and zygomatic implants as anchorage

Here is described a modified technique of palatomaxillary reconstruction that combines the use of a free vascularized bone graft by osteotomy, soft-tissue flap, zygomatic implant as an anchorage and two standard implants simultaneously. The patient presented with deformity in the left face after subtotal maxillectomy (Brown 2b classification). Preoperative work up was performed by a rapid prototyping model using computer-aided manufacturing technology. The purpose of this model is to provide accurate measurements of the defect. The palatomaxillary three-dimensional buttress system can be managed by orienting the bone graft vertically and horizontally. Reconstruction of the palatomaxillary defect was successfully accomplished in a single surgical procedure. Dental implant restoration achieved good osseointegration without any significant resorption. This new modification represents a significant contribution to palatomaxillary reconstruction using zygomatic implants as anchorage.

Carotid artery resection and reconstruction: clinical experience of 28 consecutive cases

The aim of this study was to analyse the experience at a single institution in carotid artery resection with or without reconstruction performed as part of an oncological procedure or emergency haemostasis. A total of 28 patients were included in this retrospective study; 17 underwent ligation or resection of the carotid artery, and 11 underwent reconstruction of the carotid artery. The perioperative complications and surgical outcomes were recorded and analysed. Of the 17 patients with ligation or resection of the carotid artery, 4 developed neurologic deficit within 2 weeks postoperatively. Three patients with malignant tumours died 1 month (1) and 4 months (2) postoperatively. Of the 11 patients undergoing carotid reconstruction, no major cerebral complications were noted after operation. Colour Doppler showed patent vascular graft 1 year postoperatively in nine patients. Due to the higher complication rates both in short and long term with ligation or resection of the carotid artery, resection and revascularization of the carotid artery is advocated for patients with carotid artery involvement when possible.

IR plus vacuum ultraviolet spectroscopy of neutral and ionic organic acid monomers and clusters: Propanoic acid

The vibrational spectrum of molecular propanoic acid, cooled in a supersonic expansion, in the region of 2500 to 7500 cm(-1) is obtained employing infrared plus vacuum ultraviolet nonresonant ionization detected spectroscopy. The fundamental and first overtone of the CH and OH stretch modes of cold propanoic acid molecules can be identified in the spectrum. Propanoic acid neutral and ionic clusters are also studied employing nonresonant ion dip and photodissociation spectroscopic techniques, respectively. For the neutral dimer, a sequence of features observed at ca. 2500-2700 cm(-1) can be assigned as combination bands of low frequency modes with the COH bending overtone; these features characterize the cyclic dimer ring structure. IR spectra of the larger neutral clusters n=3, 4, 5 indicate that they also have cyclic structures in which the OH groups are engaged in the cluster hydrogen bonding network. The CH groups are not involved in this hydrogen bonding structure. Free OH features are observed for the protonated ion clusters (C(2)H(5)COOH)(n)H(+), n=1,...,5, indicating that at least one OH group of these cluster ions is not involved in the cluster hydrogen bonding network. A comparison of the results for four hydrogen bonding neutral and ionic clusters (CH(3)OH, C(2)H(5)OH, CH(3)COOH, and C(2)H(5)COOH) is presented and discussed.

IR plus vacuum ultraviolet spectroscopy of neutral and ionic organic acid molecules and clusters: Acetic acid

Infrared (IR) vibrational spectroscopy of acetic acid (A) neutral and ionic monomers and clusters, employing vacuum ultraviolet (VUV), 10.5 eV single photon ionization of supersonically expanded and cooled acetic acid samples, is presented and discussed. Molecular and cluster species are identified by time of flight mass spectroscopy: the major mass features observed are A(n)H(+) (n=1-9), ACOOH(+) (VUV ionization) without IR radiation present, and A(+) with both IR and VUV radiation present. The intense feature ACOOH(+) arises from the cleavage of (A)(2) at the beta-CC bond to generate ACOOH(+)+CH(3) following ionization. The vibrational spectrum of monomeric acetic acid (2500-7500 cm(-1)) is measured by nonresonant ionization detected infrared (NRID-IR) spectroscopy. The fundamentals and overtones of the CH and OH stretches and some combination bands are identified in the spectrum. Mass selected IR spectra of neutral and cationic acetic acid clusters are measured in the 2500-3800 cm(-1) range employing nonresonant ionization dip-IR and IR photodissociation (IRPD) spectroscopies, respectively. Characteristic bands observed at approximately 2500-2900 cm(-1) for the cyclic ring dimer are identified and tentatively assigned. For large neutral acetic acid clusters A(n)(n>2), spectra display only hydrogen bonded OH stretch features, while the CH modes (2500-2900 cm(-1)) do not change with cluster size n. The IRPD spectra of protonated (cationic) acetic acid clusters A(n)H(+) (n=1-7) exhibit a blueshift of the free OH stretch with increasing n. These bands finally disappear for n> or =6, and one broad and weak band due to hydrogen bonded OH stretch vibrations at approximately 3350 cm(-1) is detected. These results indicate that at least one OH group is not involved in the hydrogen bonding network for the smaller (n< or =5) A(n)H(+) species. The disappearance of the free OH stretch feature at n> or =6 suggests that closed cyclic structures form for A(n)H(+) for the larger clusters (n> or =6).

Infrared plus vacuum ultraviolet spectroscopy of neutral and ionic methanol monomers and clusters: New experimental results

We present new observations of the infrared (IR) spectrum of neutral methanol and neutral and protonated methanol clusters employing IR plus vacuum ultraviolet (vuv) spectroscopic techniques. The tunable IR light covers the energy ranges of 2500-4500 cm(-1) and 5000-7500 cm(-1). The CH and OH fundamental stretch modes, the OH overtone mode, and combination bands are identified in the vibrational spectrum of supersonic expansion cooled methanol (2500-7500 cm(-1)). Cluster size selected IR plus vuv nonresonant infrared ion-dip infrared spectra of neutral methanol clusters, (CH(3)OH)(n) (n=2,[ellipsis (horizontal)],8), demonstrate that the methanol dimer has free and bonded OH stretch features, while clusters larger than the dimer display only hydrogen bonded OH stretch features. CH stretch mode spectra do not change with cluster size. These results suggest that all clusters larger than the dimer have a cyclic structure with OH groups involved in hydrogen bonding. CH groups are apparently not part of this cyclic binding network. Studies of protonated methanol cluster ions (CH(3)OH)(n)H(+) n=1,[ellipsis (horizontal)],7 are performed by size selected vuv plus IR photodissociation spectroscopy in the OH and CH stretch regions. Energies of the free and hydrogen bonded OH stretches exhibit blueshifts with increasing n, and these two modes converge to approximately 3670 and 3400 cm(-1) at cluster size n=7, respectively.

Infrared plus vacuum ultraviolet spectroscopy of neutral and ionic ethanol monomers and clusters

A high sensitivity spectroscopy is employed to detect vibrational antiitions of ethanol neutrals and ions in a supersonic expansion. The infrared (IR) features located at 3682 and 3667 cm(-1) can be assigned to the OH stretch for the two neutral C(2)H(5)OH conformers, anti and gauche, respectively. Their overtone energies located at 7179 (anti) and 7141 (gauche) cm(-1) are also identified. The OH fundamental stretch for ethanol ions is redshifted around 210 cm(-1), while the CH stretch modes are unchanged for neutral and ionic C(2)H(5)OH at around 2900-3000 cm(-1). The charge on the ethanol ion is apparently localized on the oxygen atom. IR induced photodissociation spectroscopy is applied to the study of neutral and protonated ethanol clusters. Neutral and protonated ethanol cluster vibrations are observed. The CH modes are not perturbed by the clustering process. Neutral clusters display only hydrogen bonded OH features, while the protonated ionic clusters display both hydrogen bonded and non-hydrogen-bonded features. These spectroscopic results are analyzed to obtain qualitative structural information on neutral and ionic ethanol clusters.

Generation and detection of alkyl peroxy radicals in a supersonic jet expansion

Alkyl peroxy radicals are synthesized in a supersonic jet expansion by the initial production of alkyl radicals and subsequent reaction with molecular oxygen. Parent ions CH3OO+/CD3OO+ are observed employing vacuum ultraviolet (VUV) single photon ionizationtime-of-flight mass spectroscopy (TOFMS). Employing infrared (IR) + VUV photofragmentation detected spectroscopy, rotationally resolved infrared spectra of jet-cooled CH3OO and CD3OO radicals are recorded for the A 2A' <-- X 2A" transition by scanning the IR laser frequency while monitoring the CH3 + and CD3 + ion signals generated by the VUV laser. The band origins of the A 2A'<--X 2A" transition for CH3OO and CD3OO are identified at 7381 and 7371 cm(-1), respectively. Rotational simulation for the CH3OO and CD3OO 0(0) 0 transitions of A<--X yields a rotational temperature for these radicals of approximately 30 K. With the aid of ab initio calculations, two and five vibrational modes for the A 2A' excited electronic state are assigned for CH3OO and CD3OO radicals, respectively. Both experimental and theoretical results suggest that the ground electronic state of the ions of ethyl and propyl peroxy radicals are not stable although their ionization energies (IE) are less than 10.5 eV. The C2H5OO+/C3H7OO+ cations can readily decompose to C2H5 +/C3H7 + and O2. This is partially responsible for the inability of IR+VUV photofragmentation spectroscopy to detect the near IR A<--X electronic transition for these radicals.

Vibronic spectroscopy of the peroxyacetyl radical in the near IR

The A 2A'<--X 2A" electronic transition of the peroxyacetyl radical (PA) is observed employing NIR/VUV ion enhancement, supersonic jet spectroscopy. Rotational envelope simulations yield a rotational temperature for ground state PA of ca. 55 K. Ab initio calculations of transition energies and vibrational frequencies for the A<--X transition assist in the assignment of the observed spectrum. A number of the vibrational modes of the A state are assigned to observed transitions (the O-O stretch 2(1), the COO bend 5(1), and the CCOO backbone bend 6(1)). The calculations and mass spectra suggest that the ground state of the PA ion is repulsive. An increase in rotational linewidth of the overtone of the O-O stretch (2(1)) is observed and discussed in terms of A state dynamics. The O-O stretch anharmonicity is estimated to be 13.35 cm(-1).

Generation and Detection of the Peroxyacetyl Radical in the Pyrolysis of Peroxyacetyl Nitrate in a Supersonic Expansion

The peroxyacetyl radical (PA, CH3C(O)OO) is generated by flash pyrolysis of peroxyacetyl nitrate (PAN, CH3C(O)OONO2) in a supersonic jet. The 0(0)(0) A2A' <-- X2A'' electronic transition for PA, at ca. 5582 cm(-1), is detected in a supersonically cooled sample by time-of-flight mass spectroscopy in the CH3CO mass channel. Rotational envelope simulation results find that the rotational temperature for PA in its ground electronic and vibrational state is ca. 55 K. At ca. 330 degrees C, the thermal decomposition of PAN by flash pyrolysis in a heated nozzle with supersonic expansion is mainly by formation of PA and NO2. The maximum yield of PA is obtained at this temperature. At higher temperatures (300-550 degrees C), an intense signal in the CH2CO+ mass channel is observed, generated by the decomposition of PA.

IR+vacuum ultraviolet (118 nm) nonresonant ionization spectroscopy of methanol monomers and clusters: Neutral cluster distribution and size-specific detection of the OH stretch vibrations

Small methanol clusters are formed by expanding a mixture of methanol vapor seeded in helium and are detected using vacuum UV (vuv) (118 nm) single-photon ionization/linear time-of-flight mass spectrometer (TOFMS). Protonated cluster ions, (CH3OH)(n-1)H+ (n=2-8), formed through intracluster ion-molecule reactions following ionization, essentially correlate to the neutral clusters, (CH3OH)n, in the present study using 118 nm light as the ionization source. Both experimental and Born-Haber calculational results clarify that not enough excess energy is released into protonated cluster ions to initiate further fragmentation in the time scale appropriate for linear TOFMS. Size-specific spectra for (CH3OH)n (n=4 to 8) clusters in the OH stretch fundamental region are recorded by IR+vuv (118 nm) nonresonant ion-dip spectroscopy through the detection chain of IR multiphoton predissociation and subsequent vuv single-photon ionization. The general structures and gross features of these cluster spectra are consistent with previous theoretical calculations. The lowest-energy peak contributed to each cluster spectrum is redshifted with increasing cluster size from n=4 to 8, and limits near approximately 3220 cm(-1) in the heptamer and octamer. Moreover, IR+vuv nonresonant ionization detected spectroscopy is employed to study the OH stretch first overtone of the methanol monomer. The rotational temperature of the clusters is estimated to be at least 50 K based on the simulation of the monomer rotational envelope under clustering conditions.

IR/UV double resonant spectroscopy of the methyl radical: Determination of ν3 in the 3pz Rydberg state

IR+UV double resonant ion-dip and ion-enhancement spectroscopies are employed to study the nu3 asymmetric CH stretch vibration fundamental of CH3 in the ground and 3p(z) Rydberg electronic states. CH3 radical is synthesized in the supersonic jet expansion by flash pyrolysis of azomethane (CH3NNCH3) prior to the expansion. The Q band of the 3(1) (1) 3p(z)<--X transition of CH3, not detected by conventional UV resonantly enhanced multiphoton ionization (REMPI) spectroscopy, is determined to lie at 59,898 cm(-1) using IR+UV REMPI spectroscopy. Energy of the asymmetric CH stretch of CH3 in the 3p(z) Rydberg state, nu3(3p(z)), is 3087 cm(-1), redshifted by approximately 74 cm(-1) with respect to ground state nu3(X).

Survey of intestinal parasites in pigs from intensive farms in Guangdong Province, People's Republic of China

The prevalence of intestinal parasites was investigated in intensive pig farms in Guangdong Province, China between July 2000 and July 2002. Faecal samples from 3636 pigs (both sexes and five age groups) from 38 representative intensive pig farms employing different parasite control strategies were examined for the presence of helminth ova and protozoan oocysts, cysts and/or trophozoites using standard techniques. Of the 3636 pigs sampled, 209 (5.7%) were infected with Trichuris suis, 189 (5.2%) with Ascaris, 91 (2.5%) with Oesophagostomum spp., 905 (24.9%) with coccidia (Eimeria spp. and/or Isospora suis) and 1716 (47.2%) with Balantidium coli. These infected pigs were mainly from farms without a strategic anti-parasite treatment regime. Concurrent infection of multiple parasites was common, and T. suis was the most common nematode infecting breeding, young and mature pigs. The results of the present investigation provide relevant 'base-line' data for assessing the effectiveness of control strategies against intestinal parasitism in intensively raised pigs in Guangdong Province, China.

High IFN-alpha expression is associated with the induction of experimental autoimmune uveitis (EAU) in Fischer 344 rat

Th1-response plays a crucial role in determining pathogenesis of organ-specific autoimmune diseases. It is believed that both IL-12 and INF-alpha are initiators to regulate Th1-response. In our experimental autoimmune uveitis (EAU) model, both Lewis and Fischer 344 rats share the same MHC class II molecules, while Lewis rat is EAU susceptible and Fischer 344 rat is EAU resistant. However, under the same condition of immunization, if pertussis toxin (PTX) was injected intraperitoneally as an additional adjuvant, Fischer 344 rat can develop EAU. In this study we investigate which mechanisms are involved in the induction of EAU in CFA+R16+PTX-treated (CRP-treated) Fischer 344 rats. In vivo and in vitro data demonstrated that Th1-cytokine, IFN-gamma mRNA expression was significantly increased in disease target tissue-eyes and in draining lymph node cells of CRP-treated Fischer 344 rat. When IL-12 and IFN-alpha mRNA expression were compared in the experimental groups, only IFN-alpha mRNA expression was associated with EAU development. To distinguish the sources of IFN-alpha producing cells, it was observed that IFN-alpha expression was mainly produced by macrophages. It was further confirmed that normal macrophage from Fischer 344 rat was able to produce significant IFN-alpha in the presence of PTX. The data strongly suggested that IFN-alpha might be involved in initiating Th1-cell differentiation and in turn contribute to the induction of EAU. High IFN-alpha expression induced by PTX may represent a novel pathway to initiate Th1 response in Fischer 344 rat.

Cell growth inhibition by the multifunctional multivalent zinc-finger factor CTCF

The 11-zinc finger protein CCTC-binding factor (CTCF) employs different sets of zinc fingers to form distinct complexes with varying CTCF- target sequences (CTSs) that mediate the repression or activation of gene expression and the creation of hormone-responsive gene silencers and of diverse vertebrate enhancer-blocking elements (chromatin insulators). To determine how these varying effects would integrate in vivo, we engineered a variety of expression systems to study effects of CTCF on cell growth. Here we show that ectopic expression of CTCF in many cell types inhibits cell clonogenicity by causing profound growth retardation without apoptosis. In asynchronous cultures, the cell-cycle profile of CTCF-expressing cells remained unaltered, which suggested that progression through the cycle was slowed at multiple points. Although conditionally induced CTCF caused the S-phase block, CTCF can also arrest cell division. Viable CTCF-expressing cells could be maintained without dividing for several days. While MYC is the well-characterized CTCF target, the inhibitory effects of CTCF on cell growth could not be ascribed solely to repression of MYC, suggesting that additional CTS-driven genes involved in growth-regulatory circuits, such as p19ARF, are likely to contribute to CTCF-induced growth arrest. These findings indicate that CTCF may regulate cell-cycle progression at multiple steps within the cycle, and add to the growing evidence for the function of CTCF as a tumor suppressor gene.

CTCF-binding sites flank CTG/CAG repeats and form a methylation-sensitive insulator at the DM1 locus

An expansion of a CTG repeat at the DM1 locus causes myotonic dystrophy (DM) by altering the expression of the two adjacent genes, DMPK and SIX5, and through a toxic effect of the repeat-containing RNA. Here we identify two CTCF-binding sites that flank the CTG repeat and form an insulator element between DMPK and SIX5. Methylation of these sites prevents binding of CTCF, indicating that the DM1 locus methylation in congenital DM would disrupt insulator function. Furthermore, CTCF-binding sites are associated with CTG/CAG repeats at several other loci. We suggest a general role for CTG/CAG repeats as components of insulator elements at multiple sites in the human genome.

An integrated approach for genome-wide gene expression analysis

Since efficient and relatively cheap methods were developed for determining biosequences, a lot of biosequence data has been generated. As the main problem in molecular biology is the analysis of the data instead of the data acquisition, part of the study of computational biology is to extract all kinds of meaningful information from the sequences. Computer-assisted methods have become very important in analyzing biosequence data. However, most of the current computer-assisted methods are limited to finding motifs. Genes can be regulated in many ways, including combinations of regulatory elements. This research is aimed at developing a new integrated system for genome-wide gene expression analysis. This research begins with a new motif-finding method, using a new objective function combining multiple well defined components and an improved stochastic iterative sampling strategy. Combinatorial motif analysis is accomplished by constructive induction that analyzes potential motif combinations. We then apply standard inductive learning algorithms to generate hypotheses for different gene behaviors. A genome-wide gene expression analysis demonstrated the value of this novel integrated system.