Research and analysis of 74 bloodstream infection cases of Acinetobacter baumannii and drug resistance

OBJECTIVE

We aimed at investigating the clinical and bacteriological features and drug resistance of bloodstream infection of Acinetobacter baumannii, so as to provide new evidence for treatment of bloodstream infection of Acinetobacter baumannii.

PATIENTS AND METHODS

Statistical analysis was carried out for the clinical and bacteriological features and drug sensitivity of 74 bloodstream infection cases of Acinetobacter baumannii who were admitted to this hospital between July 2016 and June 2017.

RESULTS

Among 74 patients, about 72.0% of them were admitted to the ICU and Respiratory Department; the average age of these patients was 63 years old. Among 74 patients, 62 patients stayed in the hospital for over 2 weeks (83.8%), and 35 for over 1 month (47.3%); 72.0% of patients experienced intrusive operation, in which 28.0% of patients dead. The experiment of drug sensitivity showed that tigecycline had the highest sensitivity (100%), sequentially followed by amikacin (over 90.0%) and other anti-bacterial drugs (less than 40.0%). Pan-drug resistance was identified in 42 patients, accounting for 56.8%. Comparison between the pan-drug resistant and non-pan-drug resistant patients showed that in the first two weeks before the positive blood culture, there were statistically significant differences in administration of carbapenem antibiotics and intrusive operation (p<0.05). Among the patients, the lowest resistance to carbapenem antibiotics was 8.16%, while the rate of resistance to other 12 antibiotics was more than 40.00%. Multiple-resistant strain mainly originated from the ICU and the burn center.

CONCLUSIONS

In patients with bloodstream infection of Acinetobacter baumannii, the pan-drug resistant strains account for a vast majority with a high mortality rate. Age, intrusive operation and length of stay in hospital longer than 2 weeks are the common susceptible factors, while the administration of carbapenem antibiotics and intrusive operations might be the high-risk factors leading to pan-drug resistant cases.

Simultaneous non-contrast angiography and intraplaque haemorrhage (SNAP) imaging for cervical artery dissections

AIM

To evaluate the feasibility of high-resolution magnetic resonance imaging (MRI) with a simultaneous non-contrast angiography and intraplaque haemorrhage (SNAP) sequence in identifying cervical artery dissections (CeAD).

MATERIALS AND METHODS

Fifty-three patients with suspected CeAD underwent the SNAP sequence (including non-contrast magnetic resonance angiography [MRA] and heavy T1-weighting vessel wall images simultaneously in a single scan) and conventional MRI sequences (including three-dimensional [3D] time-of-flight MRA and T1-weighted black-blood imaging [T1W BB]) and cervical vascular ultrasound (CVUS). In diagnosis of CeAD, the diagnostic sensitivity and specificity of SNAP, and the diagnostic coherence between SNAP and conventional sequences and between SNAP and CVUS was analysed. At follow-up, the absolute signal (AS) and signal index (SI) of the intramural haematoma (IMH) between vessel wall images on SNAP and T1W-BB images were compared. The image quality of SNAP was analysed by comparing the signal-to-noise ratio (SNR) between vessel wall images from the SNAP and T1W-BB sequences.

RESULTS

The SNAP sequence was found to provide good performance in the diagnosis of CeAD (sensitivity 72.2%, specificity 98.2%); good agreement was found between SNAP and conventional sequences (Cohen's κ=0.76, p<0.05); and excellent agreement was found between SNAP and CVUS (Cohen's κ=0.83, p<0.05). There was no significant difference between AS or SI of the IMH of the vessel wall images within the SNAP and T1W-BB sequences during the review. The SNAP sequence had higher SNR of the IMH compared to T1W-BB, T2W-BB, proton-density-weighted volume isotropic turbo-spin-echo acquisition imaging (PD-VISTA) sequences (p<0.05).

CONCLUSION

The SNAP sequence holds the potential to be preferred choice for screening of patients with a high suspicion of CeAD and for the follow-up of IMH after treatment.

Prognostic factors for treatment success in patients with multidrug-resistant tuberculosis in China

OBJECTIVE

To examine the clinical outcomes and associated prognostic factors among patients with multidrug-resistant tuberculosis (MDR-TB) in China.

METHODS

This retrospective study involved 243 patients with MDR-TB. All patients received standard regimens containing para-amino salicylic acid (PAS) and/or cycloserine (CS). The demographic, social and clinical characteristics of patients were recorded and the patients were followed up for 24 months.

RESULTS

Treatment success was closely associated with young age, non-farming occupations, shorter history or smoking, normal urine results, initial MDR-TB treatment regimen, increased haemoglobin, direct bilirubin, uric acid and thyroid stimulating hormone (TSH) levels, and lower white blood cell, neutrophil and blood platelet counts (all P < 0.05). On multivariable analysis, increased haemoglobin (hazard ratio [HR] 1.019, 95%CI 1.007-1.032, P = 0.002) and TSH levels (HR 1.002, 95%CI 1.006-1.039, P = 0.008), normal urine results (HR 1.541, 95%CI 1.008-2.358, P = 0.046) and initial MDR-TB treatment regimen (HR 2.238, 95%CI 1.090-4.597, P = 0.028) were prognostic factors for treatment success in MDR-TB.

CONCLUSIONS

Higher haemoglobin and TSH levels, normal urine results and initial MDR-TB treatment regimen might predict successful treatment of MDR-TB.

Intracellular manipulation and measurement with multipole magnetic tweezers

The capability to directly interrogate intracellular structures inside a single cell for measurement and manipulation is important for understanding subcellular and suborganelle activities, diagnosing diseases, and developing new therapeutic approaches. Compared with measurements of single cells, physical measurement and manipulation of subcellular structures and organelles remain underexplored. To improve intracellular physical measurement and manipulation, we have developed a multipole magnetic tweezers system for micromanipulation involving submicrometer position control and piconewton force control of a submicrometer magnetic bead inside a single cell for measurement in different locations (spatial) and different time points (temporal). The bead was three-dimensionally positioned in the cell using a generalized predictive controller that addresses the control challenge caused by the low bandwidth of visual feedback from high-resolution confocal imaging. The average positioning error was quantified to be 0.4 μm, slightly larger than the Brownian motion–imposed constraint (0.31 μm). The system is also capable of applying a force up to 60 pN with a resolution of 4 pN for a period of time longer than 30 min. The measurement results revealed that significantly higher stiffness exists in the nucleus’ major axis than in the minor axis. This stiffness polarity is likely attributed to the aligned actin filament. We also showed that the nucleus stiffens upon the application of an intracellularly applied force, which can be attributed to the response of structural protein lamin A/C and the intracellular stress fiber actin filaments.

Exploiting tumor-intrinsic signals to induce mesenchymal stem cell-mediated suicide gene therapy to fight malignant glioma

Background

Human mesenchymal stem cell (MSC)-based tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) gene delivery is regarded as an effective treatment for glioblastoma (GBM). However, adverse-free target site homing of the delivery vehicles to the tumor microsatellite nests is challenging, leading to erroneously sustained released of this suicide protein into the normal brain parenchyma; therefore, limiting off-target cytotoxicity and controlled expression of the suicide inductor is a prerequisite for the safe use of therapeutic stem cells.

Methods

Utilizing the intrinsic expression profile of GBM and its elevated expression of TGF-β relative to normal brain tissue, we sought to engineer human adipose-derived MSCs (hAMSC-SBE4-TRAIL) which augment the expression of TRAIL under the trigger of TGF-β signaling. We validated our therapeutic technology in a series of functional in vitro and in vivo assays using primary patient-derived GBM models.

Results

Our current findings show that these biologic delivery vehicles have high tumor tropism efficacy and expression TRAIL gene under the trigger of TGF-β-secreting GBMs, as well as avoid unspecific TRAIL secretion into normal brain tissue. hAMSC-SBE4-TRAIL inhibited the proliferation and induced apoptosis in experimental GBMs both in vitro and in vivo. In addition, our improved platform of engineered MSCs significantly decreased the tumor volume and prolonged survival time in a murine model of GBM.

Conclusions

Our results on the controlled release of suicide inductor TRAIL by exploiting an endogenous tumor signaling pathway demonstrate a significant improvement for the clinical utility of stem cell-mediated gene delivery to treat brain cancers. Harvesting immune-compatible MSCs from patients’ fat by minimally invasive procedures further highlights the clinical potential of this approach in the vision of applicability in a personalized manner. The hAMSC-SBE4-TRAIL exhibit great curative efficacy and are a promising cell-based treatment option for GBM to be validated in clinical exploration.

Electronic supplementary material

The online version of this article (10.1186/s13287-019-1194-0) contains supplementary material, which is available to authorized users.

Erythropoietin Ameliorates Lung Injury by Accelerating Pulmonary Endothelium Cell Proliferation via Janus Kinase-Signal Transducer and Activator of Transcription 3 Pathway After Kidney Ischemia and Reperfusion Injury

BACKGROUND/AIMS

Kidney ischemia and reperfusion injury could cause microvascular barrier dysfunction, lung inflammatory cascades activation, and programmed cell death of pulmonary endothelium, leading to acute lung injury. Our study aimed at determining whether erythropoietin (EPO) can ameliorate lung dysfunction following renal ischemia and reperfusion (IR) injury and explored the underlying mechanisms.

METHODS

In vivo, C57BL/6 mice received EPO (6000 U/kg) before right renal vascular pedicles clamping for 30 minutes, followed by 24 hours of reperfusion. The lung histopathologic changes and inflammatory cytokines expression were assessed. In vitro, cultured human umbilical vein endothelial cells were treated with EPO, and apoptosis rate, proliferation capacity, and phosphorylation status of the Janus kinase-signal transducer and activator of transcription 3 (Jak-STAT3) pathway were measured respectively in the presence or absence of lipopolysaccharide stimulation.

RESULTS

In vivo, EPO remarkably attenuated pulmonary interstitial and alveolar epithelial edema caused by renal IR injury. In vitro, the proliferation capacity of human umbilical vein endothelial cells was significantly increased under EPO stimulation, which correlated with changes in Jak-STAT3 signaling.

CONCLUSION

Our data indicated that EPO is able to ameliorate acute lung tissue damage induced by renal IR, and at least in part, via the Jak-STAT3 pathway.

[Study on genetic structure differences and adjustment strategies in different areas of China]

Objective: To describe the genetic structure of populations in different areas of China, and explore the effects of different strategies to control the confounding factors of the genetic structure in cohort studies. Methods: By using the genome-wide association study (GWAS) on data of 4 500 samples from 10 areas of the China Kadoorie Biobank (CKB), we performed principal components analysis to extract the first and second principal components of the samples for the component two-dimensional diagram generation, and then compared them with the source of sample area to analyze the characteristics of genetic structure of the samples from different areas of China. Based on the CKB cohort data, a simulation data set with cluster sample characteristics such as genetic structure differences and extensive kinship was generated; and the effects of different analysis strategies including traditional analysis scheme and mixed linear model on the inflation factor (λ) were evaluated. Results: There were significant genetic structure differences in different areas of China. Distribution of the principal components of the population genetic structure was basically consistent with the geographical distribution of the project area. The first principal component corresponds to the latitude of different areas, and the second principal component corresponds to the longitude of different areas. The generated simulation data showed high false positive rate (λ=1.16), even if the principal components of the genetic structure was adjusted or the area specific subgroup analysis was performed, λ could not be effectively controlled (λ>1.05); while, by using a mixed linear model adjusting for the kinship matrix, λ was effectively controlled regardless of whether the genetic structure principal component was further adjusted (λ=0.99). Conclusions: There were large differences in genetic structure among populations in different areas of China. In molecular epidemiology studies, bias caused by population genetic structure needs to be carefully treated. For large cohort data with complex genetic structure and extensive kinship, it is necessary to use a mixed linear model for association analysis.

Semi-dominant mutation in the cysteine-rich receptor-like kinase gene, ALS1, conducts constitutive defence response in rice

Plants have evolved a sophisticated two-branch defence system to prevent the growth and spread of pathogen infection. The novel Cys-rich repeat (CRR) containing receptor-like kinases, known as CRKs, were reported to mediate defence resistance in plants. For rice, there are only two reports of CRKs. A semi-dominant lesion mimic mutant als1 (apoptosis leaf and sheath 1) in rice was identified to demonstrate spontaneous lesions on the leaf blade and sheath. A map-based cloning strategy was used for fine mapping and cloning of ALS1, which was confirmed to be a typical CRK in rice. Functional studies of ALS1 were conducted, including phylogenetic analysis, expression analysis, subcellular location and blast resistance identification. Most pathogenesis-related (PR) genes and other defence-related genes were activated and up-regulated to a high degree. ALS1 was expressed mainly in the leaf blade and sheath, in which further study revealed that ALS1 was present in the vascular bundles. ALS1 was located in the cell membrane of rice protoplasts, and its mutation did not change its subcellular location. Jasmonic acid (JA) and salicylic acid (SA) accumulation were observed in als1, and enhanced blast resistance was also observed. The mutation of ALS1 caused a constitutively activated defence response in als1. The results of our study imply that ALS1 participates in a defence response resembling the common SA-, JA- and NH1-mediated defence responses in rice.

Prevalence and Potential Associated Factors of Depression among Chinese Older Inpatients

INTRODUCTION

Little is known about the current representative depression situation among Chinese older inpatients. The aim of this study is to examine prevalence of depression and associated risk factors among Chinese older inpatients by a large-scale cross-sectional national survey.

METHODS

This study is based on baseline survey data from a large-scale cohort study in a representative sample of Chinese older inpatients. The procedure of this study involves physical examination and face-to-face questionnaire interviews. Depression was assessed based on the Geriatric Depression Scale 15. Mixed-effect Poisson regression model was used to examine the relationship between depression and covariates by controlling the cluster effect of hospital wards.

RESULTS

Of all 9727 respondents, the mean age of all respondents was 72.4±5.7 years, from 65 to 97. The average GDS score was 2 (1, 4). The prevalence rate of depression was 16.7% (95%CI: 15.8-17.4%) among older inpatients. The prevalence rates were 14.6% for males and 19.5% for females respectively. After controlling the cluster effect of hospital wards, age, gender, ADL score, educational level, BMI, frail, marriage, falls, alcohol drinking, cognitive function, living conditions, vision, hearing, sleep and defecation function were associated with depression. Emaciation (OR=1.176, 95%CI: 1.107-1.249), frail (OR=1.562, 95%CI: 1.489-1.639), divorced or widowed (OR=1.083 95%CI: 1.017-1.153), living in the bungalow (OR=1.075, 95%CI: 1.023-1.130), falls (OR=1.078, 95%CI: 1.030-1.128), cognitive function (OR=1.142, 95%CI: 1.091-1.195), vision dysfunction (OR=1.125, 95%CI: 1.076-1.177), hearing dysfunction (OR=1.061, 95%CI: 1.011-1.113), sleep dysfunction (OR=1.237, 95%CI: 1.194-1.282), defecation dysfunction (OR=1.160, 95%CI: 1.103-1.221) could increase prevalence risk of depression.

CONCLUSIONS

There was a high prevalence of depression among Chinese older inpatients. Demographic characteristics, physical and mental conditions indicators have strong effect on prevalence and strength of depression. Therefore, it is essential to assess depression and perform comprehensive measures to improve physical and mental conditions in order to manage depressive symptoms in older inpatients.

Altered N-methyl D-aspartate receptor subunit expression causes changes to the circadian clock and cell phenotype in osteoarthritic chondrocytes

The chondrocyte circadian clock is altered in osteoarthritis. This change is implicated in the disease-associated changes in chondrocyte phenotype and cartilage loss. Why the clock is changed is unknown. N-methyl-D-aspartate receptors (NMDAR) are critical for regulating the hypothalamic clock. Chondrocytes also express NMDAR and the type of NMDAR subunits expressed changes in osteoarthritis.

OBJECTIVE

To determine if NMDAR regulate the chondrocyte clock and phenotype.

DESIGN

Chondrocytes isolated from macroscopically-normal (MN) and osteoarthritic human cartilage were treated with NMDAR antagonists or transfected with GRIN2A or GRIN2B-targetting siRNA. H5 chondrocytes were transfected with GluN2B-expression plasmids. Clock genes and chondrocyte phenotypic markers were measured by RT-qPCR.

RESULTS

PER2 amplitude was higher and BMAL1 amplitude lower in osteoarthritic compared to MN chondrocytes. In osteoarthritic chondrocytes, NMDAR inhibition restored PER2 and BMAL1 expression to levels similar to MN chondrocytes, and resulted in reduced MMP13 and COL10A1. Paradoxically, NMDAR inhibition in MN chondrocytes resulted in increased PER2, decreased BMAL1 and increased MMP13 and COL10A1. Osteoarthritic, but not MN chondrocytes expressed GluN2B NMDAR subunits. GluN2B knockdown in osteoarthritic chondrocytes restored expression of circadian clock components and phenotypic markers to levels similar to MN chondrocytes. Ectopic expression of GluN2B resulted in reduced BMAL1, increased PER2 and altered SOX9, RUNX2 and MMP13 expression. Knockdown of PER2 mitigated the effects of GluN2B on SOX9 and MMP13.

CONCLUSIONS

NMDAR regulate the chondrocyte clock and phenotype suggesting NMDAR may also regulate clocks in other peripheral tissues. GluN2B expression in osteoarthritis may contribute to pathology by altering the chondrocyte clock.

Natural history of serum HBV-RNA in chronic HBV infection

Virus-like particles encapsulating HBV-RNA represent a serum biomarker for assessing viral replication activity in clinical practice. However, baseline levels of serum HBV-RNA and their associations with viral replicative intermediates and liver disease in phases of chronic hepatitis B remain unknown. In this cross-sectional study, 102 patients were categorized into immune-tolerant (IT), HBeAg-positive immune active (HBeAg+IA), inactive carrier (IC) and HBeAg-negative immune active (HBeAg-IA) phases. HBV-RNA in serum samples and in 66 paired liver biopsies were quantified and correlated with serum ALT levels, histopathological scores and the levels of other viral replicative intermediates. Mean levels of serum HBV-RNA differed among phases, with the highest levels among IT (6.78 ± 0.83 log₁₀ copies mL^-1 ) patients, followed by HBeAg+IA (5.73 ± 1.16 log₁₀ copies mL^-1 ), HBeAg-IA (4.52 ± 1.25 log₁₀ copies mL^-1 ) and IC (2.96 ± 0.40 log₁₀ copies mL^-1 ) patients. Serum HBV-RNA levels correlated with HBV DNA in all phases, although correlations with other viral replicative intermediates weakened or disappeared when cases were stratified into phases. Distinct compositions of viral products were found among phases: the ratio of HBsAg to serum HBV-RNA was highest in IC patients, while the ratio of serum HBV-RNA to intrahepatic HBV-RNA and the ratio of intrahepatic HBV-DNA to intrahepatic HBV-RNA were significantly higher in IT patients. In conclusion, baseline levels of HBV-RNA and the composition of viral replicative intermediates differ significantly across the natural course of chronic HBV infection. These findings shed light on the nature of viral replication and pathogenesis of disease among different phases of chronic HBV infection.