[Progress on microneedle drug delivery systems for the treatment of corneal diseases]

Corneal diseases are prevalent eye conditions in China, and the lack of effective treatment in the short term can lead to blindness. However, delivering drugs to the cornea safely and effectively poses a significant challenge due to the presence of ocular barriers and clearance mechanisms. Conventional drug delivery methods exhibit low bioavailability, making it difficult to achieve therapeutic effects. Microneedles, with their ability to penetrate ocular surface barriers effectively, offer a low-invasive and highly promising drug delivery technology. This article introduces the main delivery barriers on the ocular surface, classifies microneedles, and highlights the latest developments in the treatment of corneal diseases. Finally, the potential challenges of applying microneedle delivery systems to the ocular surface are analyzed, aiming to provide insights for the clinical application of microneedles in corneal diseases.

Association of Molecular Subtypes with Pathologic Response, PFS, and OS in a Phase II Study of COXEN with Neoadjuvant Chemotherapy for Muscle-invasive Bladder Cancer

PURPOSE

The Coexpression Extrapolation (COXEN) gene expression model with chemotherapy-specific scores [for methotrexate, vinblastine, adriamycin, cisplatin (ddMVAC) and gemcitabine/cisplatin (GC)] was developed to identify responders to neoadjuvant chemotherapy (NAC). We investigated RNA-based molecular subtypes as additional predictive biomarkers for NAC response, progression-free survival (PFS), and overall survival (OS) in patients treated in S1314.

EXPERIMENTAL DESIGN

A total of 237 patients were randomized between four cycles of ddMVAC (51%) and GC (49%). On the basis of Affymetrix transcriptomic data, we determined subtypes using three classifiers: TCGA (k = 5), Consensus (k = 6), and MD Anderson (MDA; k = 3) and assessed subtype association with path response to NAC and determined associations with COXEN. We also tested whether each classifier contributed additional predictive power when added to a model based on predefined stratification (strat) factors (PS 0 vs. 1; T2 vs. T3, T4a).

RESULTS

A total of 155 patients had gene expression results, received at least three of four cycles of NAC, and had pT-N response based on radical cystectomy. TCGA three-group classifier basal-squamous (BS)/neuronal, luminal (Lum), Lum infiltrated, and GC COXEN score yielded the largest AUCs for pT0 (0.59, P = 0.28; 0.60, P = 0.18, respectively). For downstaging (

CONCLUSIONS

The Consensus classifier, based in part on the TCGA and MDA classifiers, modestly improved prediction for pathologic downstaging but subtypes were not associated with PFS or OS.

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Key Words Collapse

MESH Headings

• Humans
• Cisplatin/therapeutic use
• Cystectomy/methods
• Deoxycytidine/therapeutic use
• Muscles/pathology
• Neoadjuvant Therapy/methods
• Neoplasm Invasiveness
• Progression-Free Survival
• Retrospective Studies
• Urinary Bladder Neoplasms/drug therapy
• Urinary Bladder Neoplasms/genetics
• Urinary Bladder Neoplasms/pathology

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Grants

• UG1 CA233320 NCI NIH HHS
• UG1 CA233324 NCI NIH HHS
• UG1 CA180830 NCI NIH HHS
• UG1 CA233160 NCI NIH HHS
• U10 CA032102 NCI NIH HHS
• UG1 CA233196 NCI NIH HHS
• U10 CA180888 NCI NIH HHS
• U24 CA114748 NCI NIH HHS
• U10 CA180819 NCI NIH HHS
• UG1 CA233328 NCI NIH HHS

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Affiliation(s)

Seth P. Lerner Baylor College of Medicine, Houston, TX
David J. McConkey Johns Hopkins School of Medicine, Baltimore, MD
Catherine M. Tangen Fred Hutchinson Cancer Research Center, Seattle, WA
Joshua J Meeks Department of Urology, Feinberg School of Medicine, Northwestern University, Chicago, IL
Thomas W. Flaig University of Colorado, School of Medicine, University of Colorado, Aurora, CO
X Hua Fred Hutchinson Cancer Research Center, Seattle, WA
Siamak Daneshmand Department of Urology, Keck School of Medicine, University of Southern California, Los Angeles, CA
Ajjai Shivaram Alva University of Michigan, Ann Arbor, MI
M. Scott Lucia University of Colorado, School of Medicine, University of Colorado, Aurora, CO
Dan Theodorescu Cedars-Sinai CANCER, Los Angeles, CA
Amir Goldkorn University of Southern California, Los Angeles, CA
Matthew I. Milowsky University of North Carolina Lineberger Comprehensive Cancer Center, Chapel Hill, NC
W. Choi Johns Hopkins School of Medicine, Baltimore, MD
Rick Bangs SWOG Cancer Research Network, Portland, OR
Daniel L. Gustafson Colorado State University, Fort Collins, CO
Melissa Plets Fred Hutchinson Cancer Research Center, Seattle, WA
Ian M. Thompson CHRISTUS Medical Center Hospital, University of Texas Health Science Center at San Antonio, San Antonio, TX

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Prognostic Significance of the Novel Nutrition-Inflammation Marker of Lymphocyte-C-Reactive Protein Ratio in Patients with Nasopharyngeal Carcinoma Receiving Concurrent Chemoradiotherapy

PURPOSE/OBJECTIVE(S)

Recent studies indicate that the novel lymphocyte-C-reactive protein ratio (LCR) is strongly associated with the survival of various tumors, but its prognostic value in nasopharyngeal carcinoma (NPC) is understudied. This study aimed to explore the relationship between the LCR and overall survival (OS) in NPC and to develop a predictive model.

MATERIALS/METHODS

A total of 841 NPC patients received concurrent chemoradiotherapy (CCRT) were retrospectively enrolled and randomly divided into training cohort (n = 589) and validation cohort (n = 252). Univariate and multivariate Cox analyses were performed to identify variables associated with OS and construct a predictive nomogram. The predictive accuracy of the nomogram was evaluated and independently validated.

RESULTS

The LCR score differentiated NPC patients into two groups with distinct prognoses (HR = 0.53; 95% CI: 0.32-0.89, P = 0.014). Multivariate analysis showed that age, T stage, N stage, EBV-DNA status, and LCR score were independently associated with OS and a predictive nomogram was developed. The nomogram had a good performance for the prediction of OS [C-index = 0.770 (95% CI: 0.675-0.864)] and outperformed the traditional staging system [C-index = 0.589 (95% CI: 0.385-0.792)]. The results were internally validated using an independent cohort.

CONCLUSION

The novel nutrition-inflammation marker of LCR could serve as a simplified, affordable, easy-to-obtain, non-invasive, and readily promotive prognostic marker for NPC patients received CCRT, and the LCR-based prognostic nomogram outperformed the conventional staging system in terms of predictive power.

Sparse-to-dense coarse-to-fine depth estimation for colonoscopy

Colonoscopy, as the golden standard for screening colon cancer and diseases, offers considerable benefits to patients. However, it also imposes challenges on diagnosis and potential surgery due to the narrow observation perspective and limited perception dimension. Dense depth estimation can overcome the above limitations and offer doctors straightforward 3D visual feedback. To this end, we propose a novel sparse-to-dense coarse-to-fine depth estimation solution for colonoscopic scenes based on the direct SLAM algorithm. The highlight of our solution is that we utilize the scattered 3D points obtained from SLAM to generate accurate and dense depth in full resolution. This is done by a deep learning (DL)-based depth completion network and a reconstruction system. The depth completion network effectively extracts texture, geometry, and structure features from sparse depth along with RGB data to recover the dense depth map. The reconstruction system further updates the dense depth map using a photometric error-based optimization and a mesh modeling approach to reconstruct a more accurate 3D model of colons with detailed surface texture. We show the effectiveness and accuracy of our depth estimation method on near photo-realistic challenging colon datasets. Experiments demonstrate that the strategy of sparse-to-dense coarse-to-fine can significantly improve the performance of depth estimation and smoothly fuse direct SLAM and DL-based depth estimation into a complete dense reconstruction system.

Economic evaluations of interventions against influenza at workplaces: systematic review

BACKGROUND

The burden of influenza is mostly felt by employees and employers because of increased absenteeism rates, loss of productivity and associated direct costs. Even though interventions against influenza among working adults are effective, patronage and compliance to these measures especially vaccination are low compared to other risk groups.

AIMS

This study was aimed to assess evidence of economic evaluations of interventions against influenza virus infection among workers or in the workplace setting.

METHODS

The Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) reporting guideline for systematic reviews was followed. Three databases, PubMed, Web of Science and EconLit, were searched using keywords to identify relevant articles from inception till 25 October 2020. Original peer-reviewed papers that conducted economic evaluations of influenza interventions using cost-benefit, cost-effectiveness or cost-utility analysis methods focused on working-age adults or work settings were eligible for inclusion. Two independent teams of co-authors extracted and synthesized data from identified studies.

RESULTS

Twenty-four articles were included: 21 were cost-benefit analyses and 3 examined cost-effectiveness analyses. Two papers also presented additional cost-utility analysis. Most of the studies were pharmaceutical interventions (n = 23) primarily focused on vaccination programs while one study was a non-pharmaceutical intervention examining the benefit of paid sick leave. All but two studies reported that interventions against influenza virus infection at the workplace were cost-saving and cost-effective regardless of the analytic approach.

CONCLUSIONS

Further cost-effectiveness research in non-pharmaceutical interventions against influenza in workplace settings is warranted. There is a need to develop standardized methods for reporting economic evaluation methods to ensure comparability and applicability of future research findings.

Prognostic model for risk stratification of de novo metastatic nasopharyngeal carcinoma patients treated with chemotherapy followed by locoregional radiotherapy

BACKGROUND

There is no clinically applicable prognostic model designed for patients with de novo metastatic nasopharyngeal carcinoma (mNPC) treated with chemotherapy followed by locoregional radiotherapy (LRRT). We sought to develop a predictive tool of overall survival for individualized prediction and risk stratification in this heterogeneous patient population.

PATIENTS AND METHODS

A total of 244 eligible patients with de novo mNPC, who were treated with platinum-based first-line chemotherapy followed by LRRT, were included in this retrospective study. We divided patients into the training and validation sets based on the date of initial treatment, with 152 patients treated between 2008 and 2013 comprising the training set for model development and 92 patients treated at a later time (2014 to 2015) forming the validation set. We applied Cox proportional hazards model to examine factors associated with overall survival (OS). We developed and subsequently validated a prognostic model to predict OS. We assessed the performance of this prognostic model and stratified patients based on prognostic scores obtained from this proposed model.

RESULTS

The median OS of the entire cohort was 60.9 months. C-creative protein, number of metastatic sites, liver metastasis, post-treatment Epstein-Barr virus DNA, and response of metastasis were significantly associated with OS. A prognostic model for individual survival prediction was developed and graphically represented as a nomogram. The model showed favorable discrimination (C-index: 0.759), predictive accuracy [time dependent area under the curve (tAUC) at 5 years: 0.800], and calibration, and was further validated in an independent dataset. A risk stratification derived from the model can stratify these patients into three prognostic subgroups with significantly different survival.

CONCLUSION

We developed and validated a prognostic model that exhibited adequate performance in individualized prediction and risk stratification for patients with de novo mNPC treated with chemotherapy followed by LRRT.

Photorefractive effect in LiNbO3-based integrated-optical circuits for continuous variable experiments

We investigate the impact of the photorefractive effect on lithium niobate integrated quantum photonic circuits dedicated to continuous variable on-chip experiments. The circuit main building blocks, i.e. cavities, directional couplers, and periodically poled nonlinear waveguides, are studied. This work demonstrates that photorefractivity, even when its effect is weaker than spatial mode hopping, might compromise the success of on-chip quantum photonics experiments. We describe in detail the characterization methods leading to the identification of this possible issue. We also study to which extent device heating represents a viable solution to counter this effect. We focus on photorefractive effect induced by light at 775 nm, in the context of the generation of non-classical light at 1550 nm telecom wavelength.

Self-rated health scores predict mortality among people with type 2 diabetes differently across three different country groupings: findings from the ADVANCE and ADVANCE-ON trials

AIMS

To explore whether there is a different strength of association between self-rated health and all-cause mortality in people with type 2 diabetes across three country groupings: nine countries grouped together as 'established market economies'; Asia; and Eastern Europe.

METHODS

The ADVANCE trial and its post-trial follow-up were used in this study, which included 11 140 people with type 2 diabetes from 20 countries, with a median follow-up of 9.9 years. Self-rated health was reported on a 0-100 visual analogue scale. Cox proportional hazard models were fitted to estimate the relationship between the visual analogue scale score and all-cause mortality, controlling for a range of demographic and clinical risk factors. Interaction terms were used to assess whether the association between the visual analogue scale score and mortality varied across country groupings.

RESULTS

The visual analogue scale score had different strengths of association with mortality in the three country groupings. A 10-point increase in visual analogue scale score was associated with a 15% (95% CI 12-18) lower mortality hazard in the established market economies, a 25% (95% CI 21-28) lower hazard in Asia, and an 8% (95% CI 3-13) lower hazard in Eastern Europe.

CONCLUSIONS

Self-rated health appears to predict 10-year all-cause mortality for people with type 2 diabetes worldwide, but this relationship varies across groups of countries.

Down-regulation of miR-1181 indicates a dismal prognosis for nasopharyngeal carcinoma and promoted cell proliferation and metastasis by modulating Wnt/β-catenin signaling

OBJECTIVE

Our study aimed to investigate the expression pattern, clinicopathological feature and prognostic role of miR-1181 in nasopharyngeal carcinoma (NPC), and to determine the functional effects and potential mechanism of miR-1181 in NPC.

PATIENTS AND METHODS

The expression levels of miR-1181 were determined in NPC tissues and cell lines by RT-PCR. The clinical data were interpreted by chi-square test, univariate analysis, and multivariate analysis. The effect of PVT1 on proliferation was evaluated by CCK-8 and colony formation assays, and migration and invasion ability were evaluated by transwell and wound-healing assays. The association between miR-1181 and Wnt/β-catenin pathway was analyzed by Western blot.

RESULTS

We found that miR-1181 expression was significantly down-regulated in both NPC tissues and cell lines. Low expression of miR-1181 was significantly associated with N stage (p=0.013), clinical stage (p=0.037) and grade (p=0.033). Clinical assays showed that patients with low miR-1181 expression had shorter overall survival time than those with high miR-1181 expression (p=0.0007). Multivariate analysis revealed that miR-1181 expression was independently associated with the overall survival. Functional investigations indicated that overexpression of miR-1181 suppressed NPC cells proliferation, migration and invasion. Mechanistically, forced miR-1181 expression suppressed the activity of Wnt/β-catenin pathway.

CONCLUSIONS

Our findings proved that miR-1181 may serve as a candidate prognostic biomarker and target for new therapies in NPC patients.

mcr-1 facilitated selection of high-level colistin-resistant mutants in Escherichia coli

OBJECTIVES

The mcr-1 gene is the first reported plasmid-mediated colistin resistance gene. It has caused worldwide concern about the colistin resistance in Gram-negative bacteria. The aim of this research was to study the impact of mcr-1 on the selection of high-level colistin resistance (HLCR) mutations in Escherichia coli and Klebsiella pneumoniae.

METHODS

We detected the HLCR mutation rates of Enterobacteriaceae strains (K. pneumoniae XH209, KP10, and E. coli Q3, ATCC 25922) and their transformants harbouring the mcr-1 gene. Further analysis of the HLCR mutants was conducted by sequencing, plasmid elimination experiment, and real-time quantitative PCR.

RESULTS

For XH209, mean mutation rate of XH209-pMCR was 1.7 (95% confidence interval (CI) 0.76-2.54) × 10^-8, while XH209 and XH209-pCR2.1 showed mutation rates of 2.0 (95% CI, 1.32-2.67) × 10^-8 and 2.3 (95% CI 1.47-3.13) × 10^-8. For KP10 and its derived strains KP10-pCR2.1, KP10-pMCR, the mutation rates were 3.5 (95% CI 0.77-6.13) × 10^-8, 4.8 (95% CI 0.69-8.94) × 10^-8 and 4.2 (95% CI 0.95-7.54) × 10^-8 respectively. The mutation rates of E. coli strains Q3-pMCR and ATCC25922-pMCR were 3.4 (95% CI 0.19-7.47) × 10^-8 and 1.54 (95% CI 0.27-2.8) × 10^-9, which were significantly higher than their corresponding non-mcr-1-carrying strains (p < 0.05).

CONCLUSIONS

Beside the knowledge that mcr-1 mediates low-level colistin resistance, this gene also facilitates selection of HLCR mutants in E. coli, but does not affect K. pneumoniae.

[The diagnostic value of copeptin in the cardiorenal syndrome rats and the association with heart and kidney impairment]

To explore the diagnostic value of copeptin (CPP) in cardiorenal syndrome (CRS) in rats and the association between CPP and impairment of heart and kidney, 60 male SD rats were randomly divided into blank control group (CK group), kidney failure group (SNX group), heart failure group (MI group), and CRS group. Heart and kidney function and their histology changes in rats from each group were detected. The correlation between serum CPP and heart and kidney function indexes was performed with Pearson correlation analysis. The HE staining of heart and kidney showed that the tissue lesion was more severe in CRS group than in SNX group and MI group. There was a significant positive correlation between serum CPP and brain natriuretic peptide (BNP) (r=0.638, P<0.05). No correlation was observed between serum CPP and cardiac function index (left ventricular systolic pressure, left ventricular diastolic pressure, left ventricular end-diastolic pressure) or renal function index (serum creatinine, urine creatinine, blood urea nitrogen) (r=0.512, 0.189,-0.063, 0.207, 0.290, 0.595, respectively, all P>0.05). The CPP level is associated with the degree of heart and kidney damage in CRS rats.

Phylogenetic estimates of diversification rate are affected by molecular rate variation

Molecular phylogenies are increasingly being used to investigate the patterns and mechanisms of macroevolution. In particular, node heights in a phylogeny can be used to detect changes in rates of diversification over time. Such analyses rest on the assumption that node heights in a phylogeny represent the timing of diversification events, which in turn rests on the assumption that evolutionary time can be accurately predicted from DNA sequence divergence. But there are many influences on the rate of molecular evolution, which might also influence node heights in molecular phylogenies, and thus affect estimates of diversification rate. In particular, a growing number of studies have revealed an association between the net diversification rate estimated from phylogenies and the rate of molecular evolution. Such an association might, by influencing the relative position of node heights, systematically bias estimates of diversification time. We simulated the evolution of DNA sequences under several scenarios where rates of diversification and molecular evolution vary through time, including models where diversification and molecular evolutionary rates are linked. We show that commonly used methods, including metric-based, likelihood and Bayesian approaches, can have a low power to identify changes in diversification rate when molecular substitution rates vary. Furthermore, the association between the rates of speciation and molecular evolution rate can cause the signature of a slowdown or speedup in speciation rates to be lost or misidentified. These results suggest that the multiple sources of variation in molecular evolutionary rates need to be considered when inferring macroevolutionary processes from phylogenies.

Patterns of Multivitamin Use after Colorectal Cancer Diagnosis in Association with Long-term Survival

Multivitamin use has been related to a modest reduced risk of colorectal cancer (CRC), but evidence on its use after diagnosis in relation to survival has been limited. Incident, invasive CRC cases were identified through cancer registries from 1997–2008 and enrolled in four population-based sites of the Colon Cancer Family Registry (Fred Hutchinson Cancer Research Center, Cancer Care Ontario, Mayo Clinic, and the Universities of Queensland and Melbourne). At enrollment, a standardized interview ascertained multivitamin use in the year prior to diagnosis. A follow-up questionnaire was administered approximately 5 years after baseline, with 2,586 participants providing information on their multivitamin use at both time points. Survival outcomes were identified through linkage to national death registries. Delayed-entry Cox regression was used to estimate the association between patterns of multivitamin use and overall or CRC-specific survival (Hazard Ratio (HR) and 95% Confidence Interval (CI)), with survival time beginning at the 5-year follow-up survey. Models were adjusted for age at diagnosis, sex, body mass index, smoking history, stage, study center, and number of days from diagnosis to baseline survey. Over a median 4.8 years after the follow-up survey, 397 participants died (103 from CRC). Multivitamin use was common: at the 5-year follow-up, 37% reported continued use since before diagnosis, 12% had initiated use, 17% had discontinued use, and only 34% participants reported never using multivitamins. Compared to never use of multivitamins, continued use was significantly associated with increased subsequent overall survival (HR = 0.71, 95% CI: 0.55–0.91). However, this association did not reach statistical significance for CRC-specific survival (HR = 0.76, 95% CI: 0.47–1.24). No significant association was observed for discontinuing (HR = 0.92, 95% CI: 0.68–1.25) or initiating (HR = 0.80, 95% CI: 0.55–1.13) multivitamin use from baseline to follow-up, compared to never users, though initiating use trended towards increased survival. These findings suggest that continuing multivitamin use after a CRC diagnosis may increase survival; replication and details on the specific micronutrients included are needed.

Zfp462 deficiency causes anxiety-like behaviors with excessive self-grooming in mice

Zfp462 is a newly identified vertebrate-specific zinc finger protein that contains nearly 2500 amino acids and 23 putative C2H2-type zinc finger domains. So far, the functions of Zfp462 remain unclear. In our study, we showed that Zfp462 is expressed predominantly in the developing brain, especially in the cerebral cortex and hippocampus regions from embryonic day 7.5 to early postnatal stage. By using a piggyBac transposon-generated Zfp462 knockout (KO) mouse model, we found that Zfp462 KO mice exhibited prenatal lethality with normal neural tube patterning, whereas heterozygous (Het) Zfp462 KO (Zfp462^+/- ) mice showed developmental delay with low body weight and brain weight. Behavioral studies showed that Zfp462^+/- mice presented anxiety-like behaviors with excessive self-grooming and hair loss, which were similar to the pathological grooming behaviors in Hoxb8 KO mice. Further analysis of grooming microstructure showed the impairment of grooming patterning in Zfp462^+/- mice. In addition, the mRNA levels of Pbx1 (pre-B-cell leukemia homeobox 1, an interacting protein of Zfp462) and Hoxb8 decreased in the brains of Zfp462^+/- mice, which may be the cause of anxiety-like behaviors. Finally, imipramine, a widely used and effective anti-anxiety medicine, rescued anxiety-like behaviors and excessive self-grooming in Zfp462^+/- mice. In conclusion, Zfp462 deficiency causes anxiety-like behaviors with excessive self-grooming in mice. This provides a novel genetic mouse model for anxiety disorders and a useful tool to determine potential therapeutic targets for anxiety disorders and screen anti-anxiety drugs.

Abrp, a new gene, confers reduced susceptibility to tetracycline, glycylcine, chloramphenicol and fosfomycin classes in Acinetobacter baumannii

Acinetobacter baumannii, a non-fermenting gram-negative coccobacillus, is a major pathogen responsible for a variety of healthcare-associated infections, including pneumonia, urinary tract and bloodstream infections. Moreover, A. baumannii is associated with alarming increases in drug resistance rates to almost all available antibiotics leaving limited treatment options. Here, we characterize the biological functions of a novel gene, abrp, which encodes a peptidase C13 family. We demonstrate that the abrp is associated with decreased susceptibility to tetracycline, minocycline, doxycycline, tigecycline, chloramphenicol and fosfomycin. Deletion of abrp was able to increase cell membrane permeability and display slower cell growth rate. Results from the present study show that abrp plays an important role in conferring reduced susceptibility to different classes of antibiotics and cell growth in A. baumannii. The change of antibiotic sensitivities may result from modifications to the cell membrane permeability of A. baumannii.

Tracking a hospital outbreak of KPC-producing ST11 Klebsiella pneumoniae with whole genome sequencing

An outbreak of carbapenem-resistant Klebsiella pneumoniae strains emerged at a hospital, and was tracked in order to understand the spread of these infectious pathogens. A total of 66 K. pneumoniae strains were collected from sterile samples in 2012. The MICs of 20 antimicrobial agents were determined for all strains. Molecular typing was performed with pulsed-field gel electrophoresis (PFGE). Twelve blaKPC-producing K. pneumoniae strains isolated from ten patients were selected for whole genome sequencing. Phylogenetic reconstruction of these 12 strains was performed by the use of single-nucleotide polymorphism (SNP) row sequences of each draft genome sequence. Plasmids from the 12 strains were separated by S1 digestion and PFGE. The 12 K. pneumoniae strains isolated from the ten patients were deemed to be representative of the hospital outbreak, owing to their similar PFGE patterns. These 12 blaKPC-producing strains conferred multidrug resistance, which contrasted with the remaining 54, more susceptible, strains in the hospital. Differences in SNPs between each draft genome of the blaKPC-producing strains partitioned the 12 outbreak strains into three separate clades. The patients with each clade shared close hospital units. All 12 strains harboured at least one multidrug resistance plasmid. Strains showing high-level resistance may facilitate nosocomial dissemination and result in an infectious pathogen outbreak. Although the 12 blaKPC-producing K. pneumoniae strains possessed similar PFGE patterns, SNP variations throughout the genome allowed the strains to be divided into three clades. These results suggest that three independent transmission events led to hospital-wide dissemination of the outbreak strains.

The role of 3D computed tomography (CT) imaging in the diagnosis of foreign body aspiration in children

OBJECTIVE

The aim of this study was to improve the understanding of FBA in children and to decrease the rate of misdiagnosis, missed diagnosis and morbidity.

PATIENTS AND METHODS

We analyzed the clinical features and the three-dimensional reconstructed CT images of 590 children with foreign body aspiration (FBA) in the Xuzhou area of the Jiangsu province.

RESULTS

CT imaging revealed common complications of FBA including emphysema (n = 379), pneumonia (n = 174), and atelectasis (n = 26). The remaining 120 patients had no visible complications on the three-dimensional reconstructed CT images. Serious complications including pneumothorax, pneumomediastinum, subcutaneous emphysema, pneumatorrhachis could also be observed. The types of foreign bodies were diverse: the most common were peanuts and sunflower seeds. The diagnostic accuracy of the three-dimensional CT imaging was high, with a sensitivity and specificity of 99.83% and 99.89%, respectively.

CONCLUSIONS

3D CT imaging is an accurate, non-invasive technique to evaluate children with suspected FBA that can help decrease the rate of misdiagnosis and eliminate a delay in treatment for this potentially life-threatening condition.

Obesity, hypertension and diabetes mellitus affect complication rate of different nephrectomy techniques

INTRODUCTION

To investigate whether obesity, hypertension, and diabetes mellitus (DM) would increase post-nephrectomy complication rates using standardized classification method.

METHODS

We retrospectively included 843 patients from March 2006 to November 2012, of whom 613 underwent radical nephrectomy (RN) and 229 had partial nephrectomy (PN). Modified Clavien classification system was applied to quantify complication severity of nephrectomy. Fisher's exact or chi-square test was used to assess the relationship between complication rates and obesity, hypertension, as well as DM.

RESULTS

The prevalence of obesity, hypertension, and DM was 11.51%, 30.84%, 8.78%, respectively. The overall complication rate was 19.31%, 30.04%, 35.71% and 36.36% for laparoscopic radical nephrectomy (LRN), open-RN, LPN and open-PN respectively. An increasing trend of low grade complication rate as BMI increased was observed in LRN (P=.027) and open-RN (P<.001). Obese patients had greater chance to have low grade complications in LRN (OR=4.471; 95% CI: 1.290-17.422; P=0.031) and open-RN (OR=2.448; 95% CI: 1.703-3.518; P<.001). Patients with hypertension were more likely to have low grade complications, especially grade ii complications in open-RN (OR=1.526; 95% CI: 1.055-2.206; P=.026) and open PN (OR=2.032; 95% CI: 1.199-3.443; P=.009). DM was also associated with higher grade i complication rate in open-RN (OR=2.490; 95% CI: 331-4.657; P=.016) and open-PN (OR=4.425; 95% CI: 1.815-10.791; P=.013). High grade complication rates were similar in comparison.

CONCLUSIONS

Obesity, hypertension, and DM were closely associated with increased post-nephrectomy complication rates, mainly low grade complications.

Tigecycline resistance in Acinetobacter baumannii mediated by frameshift mutation in plsC, encoding 1-acyl-sn-glycerol-3-phosphate acyltransferase

Acinetobacter baumannii is an important pathogen of healthcare-associated infections and shows multidrug resistance. With the increasing application of tigecycline, isolates resistant to this antibiotic are of growing concern clinically. However, the definitive mechanism of tigecycline resistance remains unclear. To explore the mechanism of tigecycline resistance in A. baumannii, a tigecycline-resistant strain was obtained by increasing the concentration of the antimicrobial in liquid culture. Three mutations were identified by the whole genome comparison, including one synonymous substitution in a hypothetical protein and a frameshift mutation in plsC and omp38. The plsC gene was confirmed to cause decreased susceptibility to tigecycline by a complementation experiment and cellular membrane change was detected by flow cytometry. By measuring the relative growth rate, the fitness cost of plsC was estimated to be approximately 8 %. In conclusion, plsC was found to play an important role in tigecycline resistance in A. baumannii. The minor fitness cost of plsC indicates a high risk of the emergence and development of tigecycline resistance in A. baumannii.

Homocysteine induces blood vessel global hypomethylation mediated by LOX-1

Homocysteine (Hcy) is an independent risk factor of atherosclerosis through its involvement with the methionine cycle. In this study, we aimed to determine the blood vessel global methylation rate in Hcy-induced atherosclerosis in apolipoprotein-E-deficient (ApoE-/-) mice, and to explore the possible mechanism of this change in endothelial cells. ApoE-/- mice were divided into a hyperlipidemia (HLP) group, a hyperhomocysteinemia (HHcy) group, and an HHcy + folate + vitamin B12 (HHcy+FA+VB) group. Wild-type C57BL/6J mice were prepared as controls. Total Hcy, lipids, S-adenosylmethionine (SAM), and S-adenosylhomocysteine (SAH) contents in serum were measured with an automatic biochemistry analyzer and high-performance liquid chromatography. Methylation of B1 repetitive elements in blood vessels was tested using nested methylation-specific-polymerase chain reaction (nMS-PCR). Endothelial cells (ECs) were pretreated with Hcy or by adding FA and VB. Lectin-like oxidized LDL receptor-1 (LOX-1) expressions were determined by quantitative PCR, Western blot, and nMS-PCR. The HHcy group displayed severe HLP and HHcy. SAM and SAH contents were also elevated in the HHcy group compared with other groups. Methylation of B1 repetitive elements was significantly increased in the HHcy group (0.5050 ± 0.0182) compared to the HLP (0.5158 ± 0.0163) and control (0.5589 ± 0.0236) groups. mRNA and protein expressions of LOX-1 increased (0.2877 ± 0.0341, 0.6090 ± 0.0547), whereas methylation expression decreased (0.5527 ± 0.0148) after 100 μM Hcy stimulation in ECs. In conclusion, Hcy-induced atherosclerosis was closely associated with induced hypomethylation status in the blood vessel, and this process was partially mediated by LOX-1 DNA methylation.