bluuebunny/crossref_metadata_2025_split huggingface dataset:
Ciprofloxacin-resistant Escherichia coli in Central Greece: mechanisms of resistance and molecular identification
Authors: Mavroidi Angeliki , Miriagou Vivi , Liakopoulos Apostolos , Tzelepi Εva , Stefos Angelos , Dalekos George N , Petinaki Efthymia 
Published: December 2012

Abstract

Background
Fluoroquinolone resistant E. coli isolates, that are also resistant to other classes of antibiotics, is a significant challenge to antibiotic treatment and infection control policies. In Central Greece a significant increase of ciprofloxacin-resistant Escherichia coli has occurred during 2011, indicating the need for further analysis.

Methods
A total of 106 ciprofloxacin-resistant out of 505 E. coli isolates consecutively collected during an eight months period in a tertiary Greek hospital of Central Greece were studied. Antimicrobial susceptibility patterns and mechanisms of resistance to quinolones were assessed, whereas selected isolates were further characterized by multilocus sequence typing and β-lactamase content.

Results
Sequence analysis of the quinolone-resistance determining region of the gyrA and parC genes has revealed that 63% of the ciprofloxacin-resistant E. coli harbored a distinct amino acid substitution pattern (GyrA:S83L + D87N; ParC:S80I + E84V), while 34% and 3% carried the patterns GyrA:S83L + D87N; ParC:S80I and GyrA:S83L + D87N; ParC:S80I + E84G respectively. The aac (6’)-1b-cr plasmid-mediated quinolone resistance determinant was also detected; none of the isolates was found to carry the qnrA, qnrB and qnrS.
Genotyping of a subset of 35 selected ciprofloxacin-resistant E. coli by multilocus sequence typing has revealed the presence of nine sequence types; ST131 and ST410 were the most prevalent and were exclusively correlated with hospital and health care associated infections, while strains belonging to STs 393, 361 and 162 were associated with community acquired infections. The GyrA:S83L + D87N; ParC:S80I + E84V substitution pattern was found exclusively among ST131 ciprofloxacin-resistant E. coli. Extended-spectrum β-lactamase-positive ST131 ciprofloxacin-resistant isolates produced CTX-M-type enzymes; eight the CTX-M-15 and one the CTX-M-3 variant. CTX-M-1 like and KPC-2 enzymes were detected in five and four ST410 ciprofloxacin-resistant E. coli isolates, respectively.

Conclusions
Our findings suggest that, ST131 and ST410 predominate in the ciprofloxacin resistant E. coli population.
Genetic diversity of Mycobacterium tuberculosis isolates from Beijing, China assessed by Spoligotyping, LSPs and VNTR profiles
Authors: Lu Bing , Zhao Ping , Liu Binbin , Dong Haiyan , Yu Qin , Zhao Xiuqin , Wan Kanglin 
Published: December 2012

Abstract

Background
Tuberculosis is one of the most infectious diseases in the world. Molecular typing methods such as spoligotyping, and VNTR (variable number tandem repeats), IS6110 in the NTF region and LSP (large sequence polymorphisms) analysis are generally useful tools for the resolution of various issues related to the classical epidemiology of Mycobacterium tuberculosis (M. tuberculosis).

Methods
To determine the transmission characteristics of M. tuberculosis strains isolated in Beijing, China, and their genetic relationships, especially those among Beijing family strains, 260 M. tuberculosis strains isolated from patients presenting pulmonary tuberculosis were analyzed by spoligotyping, and by examining 22 VNTR loci and the presence/absence of IS6110 in the NTF region, RD105 and RD181.

Results
81% (211 strains) of the isolates studied were Beijing family strains, 174 (82.5%) of which were identified as modern Beijing strains based on the presence of IS6110 upstream of the NTF region. RD181 was intact in 9 of the other 37 (17.5%) ancestral Beijing strains. The percentage of Beijing family strains in this study was consistent with previous reports. There are many differences, however, in allele diversity among VNTR loci between reports on strains from different areas.

Conclusions
The Beijing family is the most prevalent genotype in Beijing city and the predominance of Beijing family strains has not altered in almost twenty years. Differences in the alleles and discrimination ability of VNTR loci between different regions is likely due to population differences in the regions where these M. tuberculosis strains were isolated or to differences in sampling times.
Epidemic of Klebsiella pneumoniae ST11 Clone Coproducing KPC-2 and 16S rRNA Methylase RmtB in a Chinese University Hospital
Authors: Li Jun-Jie , Sheng Zi-Ke , Deng Mei , Bi Sheng , Hu Fei-Shu , Miao Hai-Feng , Ji Zhong-Kang , Sheng Ji-Fang , Li Lan-Juan 
Published: December 2012

Abstract

Background
Emergence of rmtB-positive Klebsiella pneumoniae carbapenemase (KPC)-producing K. pneumoniae (KPC-KP) poses a great threat to antimicrobial treatment options.

Methods
From January 2010 to December 2010, non-duplicate KPC-KP isolates from our hospital were screened for rmtB and multiple other resistance determinants with PCR. Subsequent studies included MIC determination, PFGE, and multilocus sequence typing. Records from patients with KPC-KP isolated were retrospectively reviewed. Comparisons of molecular and clinical characteristics between rmtB-positive and rmtB–negative isolates were systematically performed, as well as the environmental colonization study in ICU wards.

Results
A total of 84 KPC-KP strains were collected, including 48 rmtB-positive KPC-KP (RPKP) and 36 rmtB-negative KPC-KP (RNKP) isolates. All KPC-KP isolates were multidrug resistant, with colistin and tigecycline being the most active agents. Compared with RNKP, RPKP displayed a much severer resistance phenotype. Susceptibility rates for amikacin (0% for RPKP versus 88.9% for RNKP, p < 0.01), fosfomycin (8.5% for RPKP versus 88.9% for RNKP, p < 0.01), and minocycline (6.7% for RPKP versus 52.8% for RNKP, p < 0.01), were all significantly lower in RPKP strains. Isolates belonging to PFGE pulsetype A and sequence type 11 were predominant in both groups, including 39 (81.3%) RPKP and 22 (61.1%) RNKP isolates. Nevertheless, RNKP showed more complex genetic backgrounds compared with RPKP. Diverse clinical characteristics were found in both cohorts, however, no significant differences were observed between RPKP and RNKP patients.

Conclusions
RPKP strains have spread widely and gradually replaced RNKP in our hospital. They seemed to show much severer resistance phenotypes compared with RNKP and had a bigger dissemination potential. Prudent use of available active agents combined with good control practices is therefore mandatory.
An automated method for analysis of microcirculation videos for accurate assessment of tissue perfusion
Authors: Demir Sumeyra U , Hakimzadeh Roya , Hargraves Rosalyn Hobson , Ward Kevin R , Myer Eric V , Najarian Kayvan 
Published: December 2012

Abstract

Background
Imaging of the human microcirculation in real-time has the potential to detect injuries and illnesses that disturb the microcirculation at earlier stages and may improve the efficacy of resuscitation. Despite advanced imaging techniques to monitor the microcirculation, there are currently no tools for the near real-time analysis of the videos produced by these imaging systems. An automated system tool that can extract microvasculature information and monitor changes in tissue perfusion quantitatively might be invaluable as a diagnostic and therapeutic endpoint for resuscitation.

Methods
The experimental algorithm automatically extracts microvascular network and quantitatively measures changes in the microcirculation. There are two main parts in the algorithm: video processing and vessel segmentation. Microcirculatory videos are first stabilized in a video processing step to remove motion artifacts. In the vessel segmentation process, the microvascular network is extracted using multiple level thresholding and pixel verification techniques. Threshold levels are selected using histogram information of a set of training video recordings. Pixel-by-pixel differences are calculated throughout the frames to identify active blood vessels and capillaries with flow.

Results
Sublingual microcirculatory videos are recorded from anesthetized swine at baseline and during hemorrhage using a hand-held Side-stream Dark Field (SDF) imaging device to track changes in the microvasculature during hemorrhage. Automatically segmented vessels in the recordings are analyzed visually and the functional capillary density (FCD) values calculated by the algorithm are compared for both health baseline and hemorrhagic conditions. These results were compared to independently made FCD measurements using a well-known semi-automated method. Results of the fully automated algorithm demonstrated a significant decrease of FCD values. Similar, but more variable FCD values were calculated using a commercially available software program requiring manual editing.

Conclusions
An entirely automated system for analyzing microcirculation videos to reduce human interaction and computation time is developed. The algorithm successfully stabilizes video recordings, segments blood vessels, identifies vessels without flow and calculates FCD in a fully automated process. The automated process provides an equal or better separation between healthy and hemorrhagic FCD values compared to currently available semi-automatic techniques. The proposed method shows promise for the quantitative measurement of changes occurring in microcirculation during injury.
Positive genetic interactors of HMG2 identify a new set of genetic perturbations for improving sesquiterpene production in Saccharomyces cerevisiae
Authors: Ignea Codruta , Trikka Fotini A , Kourtzelis Ioannis , Argiriou Anagnostis , Kanellis Angelos K , Kampranis Sotirios C , Makris Antonios M 
Published: December 2012

Abstract

Background
Terpenoids and isoprenoids are an important class of natural products, which includes currently used drugs, high value bioactive and industrial compounds, and fuel candidates. Due to their industrial application, there is increasing interest in the development of S. cerevisiae strains capable of producing high levels of terpenoids.

Results
Aiming to identify new gene targets which can be manipulated to increase sesquiterpene production, a set of HMG2 positive genetic interactors were assessed as single and digenic heterozygous deletions in the presence or absence of stable HMG2(K6R) overexpression. Upon single allele deletion, most genes examined led to increased sesquiterpene production in yeast cells. Tandem heterozygous deletion of a set of three genes, the ubiquitin ligases ubc7 and ssm4/doa10, and the ER resident protein pho86, led to an 11-fold increase in caryophyllene yields (125 mg/L in shake flasks) compared to cells lacking these modifications. The effect of the heterozygous deletions appears to be due to Hmg1p and Hmg2p stabilization.

Conclusion
Heterozygous deletions cause significant reductions in protein levels but do not lead to growth impediments frequently seen in haploid strains. By exploiting desirable haploinsufficiencies in yeast, we identified a new set of genes that can be disrupted in tandem and cause significant stabilization of Hmgp and a substantial increase in sesquiterpene production. The approach presented here allows new genetic perturbations to be compiled on yeast cell factory strains without negatively impacting cell growth and viability.
Degradation of a textile reactive azo dye by a combined biological-photocatalytic process: Candida tropicalis Jks2 -Tio2/Uv
Authors: Jafari Narjes , Kasra-Kermanshahi Rouha , Soudi Mohammad Reza , Mahvi Amir Hossein , Gharavi Sara 
Published: December 2012

Abstract
In the present study, the decolorization and degradation of Reactive Black 5 (RB5) azo dye was investigated by biological, photocatalytic (UV/TiO2) and combined processes. Application of Candida tropicalis JKS2 in treatment of the synthetic medium containing RB5 indicated complete decolorization of the dye with 200 mg/L in less than 24 h. Degradation of the aromatic rings, resulting from the destruction of the dye, did not occur during the biological treatment. Mineralization of 50 mg/L RB5 solution was obtained after 80 min by photocatalytic process (in presence of 0.2 g/L TiO2). COD (chemical oxygen demand) was not detectable after complete decolorization of 50 mg/L RB5 solution. However, photocatalytic process was not effective in the removal of the dye at high concentrations (≥200 mg/L). With 200 mg/L concentration, 74.9% of decolorization was achieved after 4 h illumination under photocatalytic process and the absorbance peak in UV region (attributed to aromatic rings) was not completely removed. A two-step treatment process, namely, biological treatment by yeast followed by photocatalytic degradation, was also assessed. In the combined process (with 200 mg/L RB5), absorbance peak in UV region significantly disappeared after 2 h illumination and about 60% COD removal was achieved in the biological step. It is suggested that the combined process is more effective than the biological and photocatalytic treatments in the remediation of aromatic rings.
L-glutamate released from activated microglia downregulates astrocytic L-glutamate transporter expression in neuroinflammation: the ‘collusion’ hypothesis for increased extracellular L-glutamate concentration in neuroinflammation
Authors: Takaki Junpei , Fujimori Koki , Miura Marie , Suzuki Takeshi , Sekino Yuko , Sato Kaoru 
Published: December 2012

AbstractBackgroundIn the central nervous system, astrocytic L-glutamate (L-Glu) transporters maintain extracellular L-Glu below neurotoxic levels, but their function is impaired with neuroinflammation. Microglia become activated with inflammation; however, the correlation between activated microglia and the impairment of L-Glu transporters is unknown.MethodsWe used a mixed culture composed of astrocytes, microglia, and neurons. To quantify L-Glu transporter function, we measured the extracellular L-Glu that remained 30 min after an application of L-Glu to the medium (the starting concentration was 100 μM). We determined the optimal conditions of lipopolysaccharide (LPS) treatment to establish an inflammation model without cell death. We examined the predominant subtypes of L-Glu transporters and the changes in the expression levels of these transporters in this inflammation model. We then investigated the role of activated microglia in the changes in L-Glu transporter expression and the underlying mechanisms in this inflammation model.ResultsBecause LPS (10 ng/mL, 72 h) caused a significant increase in the levels of L-Glu remaining but did not affect cell viability, we adopted this condition for our inflammation model without cell death. GLAST was the predominant L-Glu transporter subtype, and its expression decreased in this inflammation model. As a result of their release of L-Glu, activated microglia were shown to be essential for the significant decrease in L-Glu uptake. The serial application of L-Glu caused a significant decrease in L-Glu uptake and GLAST expression in the astrocyte culture. The hemichannel inhibitor carbenoxolone (CBX) inhibited L-Glu release from activated microglia and ameliorated the decrease in GLAST expression in the inflammation model. In addition, the elevation of the astrocytic intracellular L-Glu itself caused the downregulation of GLAST.ConclusionsOur findings suggest that activated microglia trigger the elevation of extracellular L-Glu through their own release of L-Glu, and astrocyte L-Glu transporters are downregulated as a result of the elevation of astrocytic intracellular L-Glu levels, causing a further increase of extracellular L-Glu. Our data suggest the new hypothesis that activated microglia collude with astrocytes to cause the elevation of extracellular L-Glu in the early stages of neuroinflammation.
ERCC1 mRNA levels can predict the response to cisplatin-based concurrent chemoradiotherapy of locally advanced cervical squamous cell carcinoma
Authors: Bai Zhou-lan , Wang Yan-yang , Zhe Hong , He Jian-li , Hai Ping 
Published: December 2012

Abstract

Background
The purpose of this study was to investigate whether the excision repair cross-complementation group 1 (ERCC1) mRNA expression could predict treatment response of patients with locally advanced cervical squamous cell carcinoma (LACSCC) who underwent cisplatin-based concurrent chemoradiotherapy (CCCRT).

Methods
A total of sixty LACSCC patients, treated with radical CCCRT from a single institution were evaluated. ERCC1 mRNA expression was determined by quantitative real-time RT-PCR in pre-treatment tumor tissues. The association of ERCC1 status with clinicopathological characteristics (age, histological grade, tumor size, parametrial invasion, lymph node metastasis and FIGO stage) and treatment response were analyzed.

Results
No significant association between ERCC1 mRNA expression and clinicopathological characteristics were observed. Patients with low ERCC1 mRNA level had a significantly higher rate of complete response (86.21%) than patients with high level of ERCC1 expression (19.36%; p < 0.001). In the logistic regression analysis, low ERCC1 mRNA level retained an independent role in predicting complete response to CCCRT (P < 0.001). An ERCC1 expression level of 0.0901 was determined as an optimal cutoff value to identify complete response patients to CCCRT treatment. The sensitivity for detection of a complete response was 81.48% with a specificity of 96.97% (area under the curve, 0.893; 95% confidence interval, 0.804–0.983).

Conclusions
This is the first analysis of the association between ERCC1 mRNA levels and treatment response in patients with LACSCC. Low ERCC1 mRNA level appears to be a highly specific predictor of response to CCCRT in LACSCC.
The effect of glial fibrillary acidic protein expression on neurite outgrowth from retinal explants in a permissive environment
Authors: Toops Kimberly A , Hagemann Tracy L , Messing Albee , Nickells Robert W 
Published: December 2012

Abstract

Background
Increased expression of glial fibrillary acidic protein (GFAP) within macroglia is commonly seen as a hallmark of glial activation after damage within the central nervous system, including the retina. The increased expression of GFAP in glia is also considered part of the pathologically inhibitory environment for regeneration of axons from damaged neurons. Recent studies have raised the possibility that reactive gliosis and increased GFAP cannot automatically be assumed to be negative events for the surrounding neurons and that the context of the reactive gliosis is critical to whether neurons benefit or suffer. We utilized transgenic mice expressing a range of Gfap to titrate the amount of GFAP in retinal explants to investigate the relationship between GFAP concentration and the regenerative potential of retinal ganglion cells.

Findings
Explants from Gfap

-/-
and Gfap

+/-
mice did not have increased neurite outgrowth compared with Gfap

+/+
or Gfap over-expressing mice as would be expected if GFAP was detrimental to axon regeneration. In fact, Gfap over-expressing explants had the most neurite outgrowth when treated with a neurite stimulatory media. Transmission electron microscopy revealed that neurites formed bundles, which were surrounded by larger cellular processes that were GFAP positive indicating a close association between growing axons and glial cells in this regeneration paradigm.

Conclusions
We postulate that glial cells with increased Gfap expression support the elongation of new neurites from retinal ganglion cells possibly by providing a scaffold for outgrowth.
Evaluation of efficacy of iodine prophylaxis in Poland based on the examination of schoolchildren living in Opoczno Town (Lodz Voivodship)
Authors: Zygmunt Arkadiusz , Adamczewski Zbigniew , Wojciechowska-Durczyńska Katarzyna , Cyniak-Magierska Anna , Krawczyk-Rusiecka Kinga , Zygmunt Agnieszka , Karbownik-Lewińska Małgorzata , Lewiński Andrzej 
Published: December 2012

Abstract

Background
In 1997 a currently obligatory model of iodine prophylaxis, based on mandatory iodization of household salt with 30 mg KI/kg, was introduced. The aim of our study was to assess the iodine intake among school-age children living in Opoczno in 3 subsequent time points – in 1994, before establishment of currently operating model of iodine prophylaxis, in 1999 – 2 years after implementation of iodine prophylaxis and in 2010, – 14 years after its implementation.

Methods
We assessed goitre incidence and urine iodine concentration (UIC) in 104 children in 1994, 207 children in 1999 and 174 children in 2012. Age of examined children ranged from 6 to 15 years. The thyroid volumes evaluated by ultrasound were compared to reference values for thyroid volume proposed by Zimmermann at al. Moreover, we have introduced a new index – V/BSA ratio (comparison of thyroid volume to the body surface area), which to our belief allows for more accurate assessment of thyroid volume.

Results
The median of UICs was 45.5 μg/L (1994), 101.1 μg/L (1999) and 100.6 μg/L (2010). The distribution of obtained results has changed as well – iodine concentrations below 50 μg/L were present in 59.1% children in 1994, in 12.6% children – in 1999 and in 7.1% children – in 2010.
Although a significant decrease in goitre incidence with regard to age – 92.6% (1994) vs 18.5% (1999) and 15.8% (2010), as well as with regard to BSA – 95.4% (1994) vs 15.2% (1999) and 11.6% (2010) was observed, it still points to the iodine deficiency, which is in contradiction with UICs as they are within normal limits. V/BSA ratio avoids such discrepancy. The values of ratio V/BSA were higher in 1994 (7.079 ± 2.775) than in 1999 (2.935 ± 1.112) (p<0.05) and in 2010 (2.846 ± 1.029) (p<0.05).

Conclusions
Hitherto model of iodine prophylaxis has proved to be effective in eliminating the iodine deficiency. The iodine intake is now more even, homogenous, which translates into smaller scatter of UICs and less percentage of children, in whom UIC is less than 50 μg/L. However, the iodine intake only slightly exceeds the recommended values, so median of UICs oscillates around the lower limit of references values.
ABT-737 reverses the acquired radioresistance of breast cancer cells by targeting Bcl-2 and Bcl-xL
Authors: Li Ji-Yu , Li Yu-Yang , Jin Wei , Yang Qing , Shao Zhi-Ming , Tian Xing-Song 
Published: December 2012

Abstract

Background
Acquired radioresistance of cancer cells remains a fundamental barrier to attaining the maximal efficacy of radiotherapy for the treatment of breast cancer. Anti-apoptotic proteins, such as Bcl-2 and Bcl-xL, play an important role in the radioresistance of cancer cells. In the present study, we aimed to determine if ABT-737, a BH3-only mimic, could reverse the acquired radioresistance of the breast cancer cell line MDA-MB-231R by targeting Bcl-2 and Bcl-xL.

Methods
The radiosensitivity of MDA-MB-231 and MDA-MB-231R cells was compared using colony formation assays. Reverse-transcription PCR and western blot were performed to detect the expression of Bcl-2 and Bcl-xL in the cancer cell lines. Annexin V flow cytometric analysis and caspase-3 colorimetric assay were used to evaluate apoptosis of the cancer cells. Cell viability was measured using the Cell Counting Kit-8. The animals used in this study were 4 to 6-week-old athymic female BALB/c nu/nu mice.

Results
The MDA-MB-231R cells were more radioresistant than the MDA-MB-231 cells, and Bcl-2 and Bcl-xL were overexpressed in the MDA-MB-231R cells. While ABT-737 was able to restore the radiosensitivity of the MDA-MB-231R cells in vitro and in vivo experiment, it was not able to enhance the radiosensitivity of the MDA-MB-231 cells. In addition, ABT-737 increased radiation-induced apoptosis in the MDA-MB-231R cells. Bcl-2 and Bcl-xL were down regulated in the MDA-MB-231R cells following treatment with ABT-737.

Conclusions
Targeting of the anti-apoptotic proteins Bcl-2 and Bcl-xL with ABT-737 may reverse the acquired radioresistance of MDA-MB-231R cells in vitro and in vivo. These findings suggest an attractive strategy for overcoming the acquired radioresistance of breast cancer cells.