[Characteristics of epidemiology and antimicrobial resistance of gram-negative bacterial bloodstream infections in children]

Objective: To study the epidemiology and antimicrobial resistance of Gram-negative bacterial bloodstream infections in children, and to guide the choice of antimicrobials and the control of nosocomial infection. Method: Clinical data, bacteriology and antimicrobial susceptibility test results were collected retrospectively in hospitalized children who were diagnosed with gram-negative bacterial bloodstream infections in Yuying Children's Hospital of Wenzhou Medical University from January, 2010 to December, 2015. Result: A total of 399 cases (253 male and 146 female) were identified. The age ranged from 16 hours to 16 years (median age 10.1 months). The majority of cases were collected from division of neonatology (n=261, 65.4%), followed by 31 cases (7.8%) from pediatric intensive care unit and 29 cases (7.3%) from Gastroenterology Department; 275 cases (68.9%) had underlying diseases, mainly including preterm birth(n=172), neonatal respiratory distress syndrome(n=67) and newborn asphyxia(n=53). Eighty cases had received invasive procedures and 20 had surgical operation; 149 cases (37.3%) were community-acquired and 250 cases (62.7%) were hospital acquired. Fifty cases had complications, among those, 40 cases had septic shock, 32 cases had multiple organ dysfunction syndrome and 7 cases had disseminated intravascular coagulation; 288 cases were cured, 48 improved, 17 gave up treatment and discharged, and 46 died; totally 408 strains were isolated from 399 children, including Enterobacteriaceae (346, 84.8%), non-fermentative Gram-negative bacteria (49, 12.0%) and other gram-negative bacteria (13, 3.2%). The resistance rates of Escherichia coli (n=175) and Klebsiella pneumoniae (n=106) to carbapenems, β-lactams enzyme and its inhibitors, amikacin and cefoxitin were all lower than 10%. Totally 245 multi-drug resistant strains (60.1%) were isolated, including 225 strains of Enterobacteriaceae and 18 strains of non-fermentative Gram-negative bacteria (P<0.01) . Nine strains of Carbapenem-resistant Enterobacteriaceae were isolated, which were all sensitive to amikacin and the sensitive rates to fluoroquinolone reached 88.9%. Five strains which were detected sensitive to tigecycline were all sensitive. The proportion of Klebsiella sp in Gram-negative bacteria between 2013-2015 and 2010-2012 were 32.9% and 21.2%, respectively. The resistance rates of Escherichia coli and Klebsiella pneumoniae to β-lactams and its enzyme inhibitors and carbapenems had no significant change. Conclusion: Gram-negative bacterial bloodstream infections occur more frequently in newborns. Most children had combined underlying diseases. Escherichia coli and Klebsiella pneumoniae are the most common pathogens. β-Lactams and its enzyme inhibitors and carbapenems are the empirical choice of antimicrobial therapy for severe Enterobacteriaceae bloodstream bacterial infections.

Extracellular diffusion quantified by magnetic resonance imaging during rat C6 glioma cell progression

Solution reflux and edema hamper the convection-enhanced delivery of the standard treatment for glioma. Therefore, a real-time magnetic resonance imaging (MRI) method was developed to monitor the dosing process, but a quantitative analysis of local diffusion and clearance parameters has not been assessed. The objective of this study was to compare diffusion into the extracellular space (ECS) at different stages of rat C6 gliomas, and analyze the effects of the extracellular matrix (ECM) on the diffusion process. At 10 and 20 days, after successful glioma modeling, gadolinium-diethylenetriamine pentaacetic acid (Gd-DTPA) was introduced into the ECS of rat C6 gliomas. Diffusion parameters and half-life of the reagent were then detected using MRI, and quantified according to the mathematical model of diffusion. The main ECM components [chondroitin sulfate proteoglycans (CSPGs), collagen IV, and tenascin C] were detected by immunohistochemical and immunoblot analyses. In 20-day gliomas, Gd-DTPA diffused more slowly and derived higher tortuosity, with lower clearance rate and longer half-life compared to 10-day gliomas. The increased glioma ECM was associated with different diffusion and clearance parameters in 20-day rat gliomas compared to 10-day gliomas. ECS parameters were altered with C6 glioma progression from increased ECM content. Our study might help better understand the glioma microenvironment and provide benefits for interstitial drug delivery to treat brain gliomas.

[Changes in genotype prevalence of human papillomavirus over 10-year follow-up of a cervical cancer screening cohort]

Objective: To evaluate the dynamic variation of genotypes distribution of human papillomavirus (HPV) over 10-year follow-up in a cervical cancer screening cohort. Methods: Based on the Shanxi Province Cervical Cancer Screening Study Ⅰ cohort, we detected HPV genotypes on the well-preserved exfoliated cervical cells from women who were tested HPV positive from year 2005 to year 2014 using reverse linear probe hybridization assay. The changes of prevalence of type-specific HPV over time among the overall population were estimated using linear mixed models. The association between the type-specific HPV and cervical intraepithelial neoplasia grade 2 or worse (CIN2 +) was calculated by linear Chi-square test. Finally, the trends of multiple infections of HPV with the increase of the age were analyzed. Results: During the cervical cancer screening of the overall population from 2005 to 2014, the most common genotypes among the population were HPV16 and 52. The prevalence of HPV16 decreased over time from 4.6% in 2005 to 2.2% in 2010 and 2014 (F=8.125, P<0.001). The prevalence of HPV52 remained pretty stable and HPV33, 51 and 58 slightly decreased then apparently increased. Further stratification analysis by pathological lesions showed the same trend of the HPV prevalence for the histology normal women with the overall population. Of note, for those women with the cervical intraepithelial neoplasia (CIN2 +), the detection rate of HPV16 decreased from 65.22% in 2005 to 41.03% in 2010 and finally to 31.58% in 2014 (χ(2)=4.420, P=0.036) and that of HPV33 substantially increased. No significant variation was found for other types of HPV. Multiple infection rate varied with the growing age of the women. Conclusions: The genotypes prevalence of HPV tended to vary over time during cervical cancer screening in the context of regular screening combining with immediate treatment for those CIN2 + women. HPV16 prevalence significantly decreased over time, which indicated that the variation of type-specific HPV prevalence should be considered when regular cervical cancer screening was organized using HPV technique.

Quantitative analysis of efficacy and associated factors of calcium intake on bone mineral density in postmenopausal women

A model-based meta-analysis method was performed to quantitatively analyze the efficacy characteristics of calcium intake in BMD increase among postmenopausal women. We found that age and calcium intake dose were key factors affecting the efficiency and onset of BMD change, and daily 1200 mg calcium was suggested to be a beneficial dosage.

INTRODUCTION

This paper aims to quantify the efficacy of calcium intake in preventing bone mineral density (BMD) decrease among postmenopausal women and to investigate the factors that may affect the efficacy.

METHODS

Comprehensive literature search was conducted in PubMed and EMBASE from January 2016. Placebo-controlled or no-treatment controlled randomized trials focused on calcium intake for the management of osteoporosis in postmenopausal women were included. The clinical and demographic characteristics of participants and efficacy data, defined as the mean percentage change of spine BMD (L2-L4) at each observation time point compared with that of baseline, were extracted from the studies. Model-based meta-analysis (MBMA) was used to describe the time course of BMD change by calcium intake and identify the related factors.

RESULTS

This study includes 17 trials involving 2537 subjects. The results showed that a classic pharmacodynamic maximal effect (E _max) model could describe the time course of BMD change by calcium intake. Using this model, we found that age and calcium intake dose were key factors affecting the efficiency and onset of BMD change. A 60-year-old woman administered with 800 mg/day calcium can achieve a maximum BMD increasing rate of 2.38%, and the time to reach 50% of this maximum (known as onset time) was 9.44 months. An increase of 0.0817% per year was noted in the maximal effect value for women aged between 50 and 83 years. For calcium dose interval from 250 to 2000 mg/day, the onset time was expressed as 9.44 × (dose/800)^-1.33 months. Two-year calcium intake of 700, 1200, and 2000 mg/day resulted in a maximum efficacy of BMD of 68.0, 81.3, and 89.6%, respectively. This indicates that the final efficacy had already reached the plateau (>80% E _max) under the 1200-mg/day dose.

CONCLUSION

Calcium intake can effectively postpone the tendency of BMD decrease in postmenopausal women. An increased calcium dose contributes to the shortening of the onset time. Considering the drug-acting rate and safety into account, menopausal women can be administered with a rational dose of 1200 mg/day to reduce bone loss.

[Current situation and thinking of diagnosis and treatment in some types of thyroid cancer]

As arising incidence of thyroid cancer, the treatment for thyroid carcinoma is becoming increasingly standardized. But there are different opinions on the treatment for some types of thyroid cancers, including the determination of operative opportunity, surgical method, and follow-up observation plan. There are mainly two categories of patients, namely the patients diagnosed as familial thyroid cancer mutation carriers through family screening, including medullary thyroid carcinoma and familial nonmedullary thyroid carcinoma, and the patients with thyroid microcarcinoma that can be observed after diagnosed by fine needle biopsy cytology. We will discuss current situation for the diagnosis and treatment of these patients.

Piccolo mediates EGFR signaling and acts as a prognostic biomarker in esophageal squamous cell carcinoma

The presynaptic cytomatrix protein Piccolo, encoded by PCLO, is frequently mutated and amplified in esophageal squamous cell carcinoma (ESCC), but its exact roles in ESCC remain unclear. Here we report that Piccolo expression correlates significantly with clinical stage, patient survival and tumor embolus. Functional studies demonstrate that PCLO knockdown remarkably attenuates ESCC malignancy in vitro and in vivo, and ectopic EGFR expression partially compensates for Piccolo loss. PCLO knockdown promotes ubiquitination and degradation of EGFR, which is associated with the negative regulatory effect of Piccolo on E3 ligase Siah1. An anti-Piccolo monoclonal antibody inhibited tumor proliferation in a mouse model of ESCC. These results demonstrate that Piccolo contributes to tumor aggressiveness in ESCC, likely by stabilizing EGFR and promoting EGFR-dependent signaling. Our results further suggest that Piccolo may represent a novel prognostic biomarker and therapeutic target for patients with ESCC.

[The multicenter study on the registration and follow-up of low anticoagulation therapy for the heart valve operation in China]

OBJECTIVE

To investigate the optimal anticoagulation methods and monitoring strategy for Chinese patients undergoing heart valve replacement, which is potentially quite different from western populations.

METHODS

In this multicenter prospective cohort study, the anticoagulation and monitoring strategy data was acquired from 25 773 in-hospital patients in 35 medical centers and 20 519 patients in outpatient clinic in 11 medical centers from January 1st, 2011 to December 31th, 2015.

RESULTS

As for in-hospital patients, mean age of study population was (48.6±11.2) years old; main etiology of valve pathology was rheumatic (87.5%) origin among study cohort; 94.8% of study population received mechanical valve implantation; international normalized ratio (INR) monitoring (in all the study centers) and low-intensity anticoagulation strategy (31 hospitals chose target INR range of 1.5-2.5, and actual values of INR among 89.2% of 100 069 in-hospital monitoring samples were 1.5-2.5), with mean actual INR values of 1.84±0.53, and warfarin dosage of (2.82±0.93) mg/d were widely adopted among the study centers; strategies of in-hospital warfarin administration were similar in all the study centers; complication rates of low-intensity anticoagulation strategy were low in severe hemorrhage (0.02%), thrombosis (0.05%), and thromboembolism (0.05%) events, without anticoagulation-related death.As for 18 974 outpatient clinic patients, the follow-up rate was 92.47%, with a total of 30 012 patient-years (Pty). Anticoagulation-related morbidity and mortality rates were 0.67% and 0.15% Pty; major hemorrhage morbidity and mortality rates were 0.25% and 0.13% Pty; thromboembolism morbidity and mortality rates were 0.45% and 0.03% Pty.The mean dosage of warfarin daily dosage was (2.85±1.23) mg/d and INR value was 1.82±0.57.No significant regional difference in the intensity of anticoagulation therapy was noted during the study.

CONCLUSIONS

INR can be used as a normalized indicator for intensity of anticoagulation therapy in China.The optimal anticoagulation intensity with INR range from 1.5 to 2.5 is safe and effective for Chinese patients with heart valve replacement, and there is no significant regional difference in the intensity of anticoagulation therapy.

The gene polymorphisms of IL-8(-251T/A) and IP-10(-1596C/T) are associated with susceptibility and progression of type 2 diabetic retinopathy in northern Chinese population

PurposeThe aim of the present study is to investigate the association of the polymorphism of two genes in CXC chemokine family, interleukin-8 (IL-8) and interferon-inducible protein 10 (IP-10), with both susceptibility and progression of DR in T2D population of northern China.Patients and methodsA total of 1043 eligible type 2 diabetic patients from Heilongjiang of northern China were recruited for this study. They were grouped into: with diabetic retinopathy (DR, 528 cases) and without diabetic retinopathy (DNR, 515 cases). Single nucleotide polymorphism (SNP) genotyping of IL-8(-251T/A) and IP-10(-1596C/T) was performed by polymerase chain reaction. Multivariate analysis and stepwise multiple logistic progression analysis were conducted to evaluate the association between gene SNP and DR susceptibility and progression. Pooled odds ratio (OR) with 95% confidence interval (CI) was applied to assess the strength of the association among study groups.ResultsThe occurring of IL-8(-251) AA genotype was correlated with susceptibility (OR: 2.286, 95% CI: 1.382-3.782, P=0.001) and progression of high-risk proliferative diabetic retinopathy (PDR) (OR: 0.354, 95% CI: 0.162-0.770, P=0.009). Reversely, T allele of IP-10 (-1596) C/T was correlated with a reduced risk of DR (OR: 0.341, 95% CI: 0.249-0.466, P<0.001). However, gene polymorphisms of IL-8-251T/A and IP-10-1596C/T were not associated with diabetic macular edema (DME)(P>0.05).ConclusionsAA genotype of IL-8-251T/A was closely correlated to DR and high-risk proliferative diabetic retinopathy (PDR). -1596T allele of the IP-10 is a beneficial genotype for DR.

Krüppel-like factor 2 suppresses growth and invasion of gastric cancer cells in vitro and in vivo

Krüppel-like factor 2 (KLF2), a novel tumor-suppressor gene, is implicated in diverse cellular processes, including cell growth, apoptosis, and invasion. However, the role and action mechanisms of KLF2 in gastric cancer (GC) need be further elucidated. The expression of KLF2 was investigated by immunohistochemical assay in human GC tissues, and lentivirus-mediated KLF2 overexpression was transfected into GC cells (AGS and HGC-27) for assessing cell proliferation and invasion, respectively indicated by MTT and Transwell assays. Subcutaneous GC tumor models were constructed for estimating tumor growth in vivo. As a result, the expression level of KLF2 was decreased in GC tissues compared with the para-carcinoma tissues (31.03% vs 53.45%, P=0.035), and negatively correlated with the lymph node metastasis in GC patients (P=0.02). Moreover, overexpression of KLF2 inhibited the cell proliferation and invasive potential and downregulated the protein expression of PCNA, Bcl-2 and MMP-9 in GC cells. The result in vivo showed KLF2 overexpression reduced the xenograft tumor growth. In conclusion, our findings indicate that KLF2 may function as a tumor suppressor involved in the progression of human GC.

Kinetic analysis of RNA editing of Newcastle disease virus P gene in the early period of infection

As a paramyxovirus, Newcastle disease virus (NDV) has the ability to edit its P (phosphoprotein) gene to synthesize three kinds of viral protein (P, V and W). It is technically very difficult to differentiate P, V and W mRNAs, and little was known about NDV regulation of RNA-editing frequency. To investigate the rules of NDV RNA editing, the ratio of the P gene-derived transcripts (P, V and W) was determined by sequencing at different time points post-infection. The results showed unstable ratio of V and W mRNA at different time points, and the frequency of NDV editing was significantly increased at the early period of infection (P 

KEYWORDS

Newcastle disease virus; phosphoprotein; RNA editing; G insertion.