Phase transitions in the classical exchange-anisotropic Kitaev-Heisenberg model

The Kitaev model on the honeycomb lattice has been receiving substantial attention due to the discovery of quantum spin liquid state associated with this model. Consequently, its classical partners such as the Kitaev-Heisenberg (KH) model and associated phase transitions become concerned. Specifically, an intermediate Kosterlitz-Thouless (KT) phase engaged in the transition from the high-temperature (T) disordered state to the low-T sixfold degenerate state is predicted in the isotropic KH model [Phys. Rev. Lett. 109, 187201 (2012)10.1103/PhysRevLett.109.187201], but so far no sufficient experimental proof has been reported. In this work, we consider an essential extension of this KH model on the honeycomb lattice by including the Kitaev exchange anisotropy that is non-negligible in realistic materials. The associated phase transitions are thus investigated using the Monte Carlo simulations. It is found that such an anisotropy will result in a degradation of the sixfold degeneracy of the ground state in the isotropic KH model down to the fourfold or twofold degenerate ground state, and the finite-T phase transitions will also be modified remarkably. Interestingly, the intermediate KT phase can be suppressed by this Kitaev exchange anisotropy. This work thus provides a more realistic description of the physics ingredient with the KH model and presents a possible explanation on absence of the intermediate phase in real materials where the Kitaev exchange anisotropy can be more or less available.

[Construction of urban scale-free network model and its epidemiological significance in the prevention and control of COVID-19]

COVID-19 is a public health emergency currently. In this study, a scale-free network model is established based on the Spring Migration data in 2020.The cities is clustered into three different modules. The epidemic of the cities in the black module was the most serious, followed by the red and the cyan. The black module contains 9 cities in Zhejiang province and 8 cities in Guangdong province, most of them located in the southeast coastal economic belt. These cities should be the key cities for epidemic prevention and control.

Cerebral Microbleeds Are Associated with Loss of White Matter Integrity

BACKGROUND AND PURPOSE

Previous studies have shown that diffusion tensor imaging suggests a diffuse loss of white matter integrity in people with white matter hyperintensities or lacunes. The purpose of this study was to investigate whether the presence of cerebral microbleeds and their distribution are related to the integrity of white matter microstructures.

MATERIALS AND METHODS

The study comprised 982 participants who underwent brain MR imaging to determine microbleed status. The cross-sectional relation between microbleeds and the microstructural integrity of the white matter was assessed by 2 statistical methods: a multilinear regression model based on the average DTI parameters of normal-appearing white matter and Tract-Based Spatial Statistics analysis, a tract-based voxelwise analysis. Fiber tractography was used to spatially describe the microstructural abnormalities along WM tracts containing a cerebral microbleed.

RESULTS

The presence of cerebral microbleeds was associated with lower mean fractional anisotropy and higher mean diffusivity, axial diffusivity, and radial diffusivity, and the association remained when cardiovascular risk factors and cerebral small-vessel disease markers were further adjusted. Tract-Based Spatial Statistics analysis indicated strictly lobar cerebral microbleeds associated with lower fractional anisotropy, higher mean diffusivity, and higher radial diffusivity in the internal capsule and corpus callosum after adjusting other cerebral small-vessel disease markers, while only a few voxels remained associated with deep cerebral microbleeds. Diffusion abnormalities gradients along WM tracts containing a cerebral microbleed were not found in fiber tractography analysis.

CONCLUSIONS

Cerebral microbleeds are associated with widely distributed changes in white matter, despite their focal appearance on SWI.

[Clinical features and prognosis of pneumocystis pneumonia in patients treated with rituximab for autoimmune diseases]

Objective: To determine the clinical features and outcomes of pneumocystic pneumonia (PCP) in patients treated with rituximab for autoimmune diseases. Methods: PCP patients with autoimmune diseases as underlying diseases from January 2009 to April 2019 in Peking University First Hospital (male 67 cases, female 35 cases, age 17-79) were retrospectively reviewed. Patients were grouped as rituximab group and non-rituximab group based on the fact if they were treated with rituximab before the onset of PCP. Demographic data, clinical features, and outcomes of the two groups were analyzed. Results: There were 102 cases altogether, and 7 patients were treated with rituximab before the onset of PCP. Patients in rituximab group were relatively younger than that in non-rituximab group [(32.0±18.7) vs (52.4±14.9) years, P=0.010]. Patients in rituximab group had more CD3(+), CD4(+), CD8(+)T lymphocytes in peripheral blood samples than that in non-rituximab group [(1 306±596) vs (546±439)/μl, (674±401) vs (243±232)/μl, (616±249) vs (282±256)/μl, respectively, all P<0.01]. However, the B lymphocyte count and plasma level of IgG and IgM were significantly lower in rituximab group than that in non-rituximab group [0 (0, 0.2) vs 72 (50.0, 124.4)/μl, 4.0 (2.6, 5.8) vs 9.4 (5.3, 12.0) g/L, 0.3 (0.2, 1.0) vs 1.1 (0.6, 1.8) g/L, respectively, all P<0.05]. The incidence of Cytomegalovirus (CMV) pneumonia was significantly lower in rituximab group (0/7 and 57/95, P=0.007). Other demographic data, the use of corticosteroids, the incidence of severe PCP, mechanical ventilation, intubation, pneumothorax and mediastinal emphysema complications, as well as hospital mortality and length of stay in hospital in the two groups were comparable. Conclusions: In patients treated with rituximab for autoimmune diseases, the number of B lymphocytes in peripheral blood and the plasma level of immunoglobulins but not CD3(+), CD4(+), and CD8(+)T lymphocyte counts may play an important role in the pathogenesis of PCP. These patients are not vulnerable to be complicated with CMV pneumonia.

Universal scaling of weak localization in graphene due to bias-induced dispersion decoherence

The differential conductance of graphene is shown to exhibit a zero-bias anomaly at low temperatures, arising from a suppression of the quantum corrections due to weak localization and electron interactions. A simple rescaling of these data, free of any adjustable parameters, shows that this anomaly exhibits a universal, temperature- (T) independent form. According to this, the differential conductance is approximately constant at small voltages (V < kBT/e), while at larger voltages it increases logarithmically with the applied bias. For theoretical insight into the origins of this behaviour, which is inconsistent with electron heating, we formulate a model for weak-localization in the presence of nonequilibrium transport. According to this model, the applied voltage causes unavoidable dispersion decoherence, which arises as diffusing electron partial waves, with a spread of energies defined by the value of the applied voltage, gradually decohere with one another as they diffuse through the system. The decoherence yields a universal scaling of the conductance as a function of eV/kBT, with a logarithmic variation for eV/kBT > 1, variations in accordance with the results of experiment. Our theoretical description of nonequilibrium transport in the presence of this source of decoherence exhibits strong similarities with the results of experiment, including the aforementioned rescaling of the conductance and its logarithmic variation as a function of the applied voltage.

MicroRNA-337-5p participates in the development and progression of osteosarcoma via ERBB, MAPK and VEGF pathways

OBJECTIVE

To investigate the role of microRNA-337-5p in osteosarcoma (OS) and its underlying mechanism.

PATIENTS AND METHODS

The microRNA (microRNA-337-5p) that may be related to OS development was screened out by GEO (Gene Expression Omnibus) database. Survival analysis and ROC curve were performed according to microRNA-337-5p expressions in OA patients. Besides, the correlation between microRNA-337-5p expression and clinical parameters was evaluated by Chi-square analysis. Cox regression analysis was performed to detect the relationship between the overall survival and clinical parameters of OA patients. Subsequently, enriched functions and pathways of microRNA-337-5p were predicted by GESA (gene enrichment sets analysis). MicroRNA-337-5p expression was detected in 65 OS tissue samples and 30 normal tissue samples by qRT-PCR (quantitative Real-Time Polymerase Chain Reaction). For in vitro experiments, after microRNA-337-5p mimics or microRNA-337-5p inhibitor was transfected into OS cells, proliferative and invasive abilities were detected by CCK-8 (Cell Counting Kit-8) and transwell assay, respectively. Finally, Western blot was used to explore the underlying mechanism of microRNA-337-5p in regulating OS.

RESULTS

MicroRNA-337-5p was overexpressed in serum and tissue samples of OS patients, which was valuable in diagnosing OS. Besides, microRNA-337-5p expression was correlated with the overall survival and necrosis range of OA patients, whereas not correlated with age and sex. GESA indicated that microRNA-337-5p was enriched in ERBB, MAPK, and VEGF pathways. In vitro experiments indicated elevated proliferative and invasive abilities in MG63 and U2OS cells after microRNA-337-5p overexpression. Furthermore, increased expressions of ERBB2, Erk1/2, and VEGF121 were observed in OS cells after microRNA-337-5p overexpression.

CONCLUSIONS

MicroRNA-337-5p is upregulated in OS tissues, which is an independent prognostic factor in OS. Overexpressed microRNA-337-5p can promote proliferative and invasive abilities of OS cells via activating ERBB, MAPK, and VEGF pathways.

Optimizing biologic sequencing in metastatic colorectal cancer: first line and beyond

Significant advances in the treatment of metastatic colorectal cancer (mcrc) since the early 2000s have led to improved clinical outcomes, including overall survival (os). When fluorouracil was the sole treatment agent for mcrc, os in phase iii studies was approximately 12 months. Now, in 2019, the median os (mos) in the most recent mcrc clinical trials has been approaching 3 years. The biologic agents that target the vascular endothelial growth factor (vegf), epithelial growth factor receptor (egfr), human epidermal growth factor receptor 2 (her2), PD-1, ctla-4, ntrk, and braf pathways play important roles in the mcrc treatment algorithm, given their significant-sometimes dramatic-activity. Emerging data indicate that the choice of a specific biologic at a particular time (line of treatment) for specific patient populations (based on tumour characteristics) is critical. In the present review, we discuss the available evidence for optimal biologic sequencing in the management of mcrc.

Identification of key pathways and genes changes in pancreatic cancer cells (BXPC-3) after cross-talk with primary pancreatic stellate cells using bioinformatics analysis

Pancreatic ductal adenocarcinoma (PDAC) is one of the most malignant tumors with poor prognosis, and the interaction between activated pancreatic stellate cells (PSCs) and PDAC cells plays an important role in the development of PDAC. The aim of this study was to identify gene changes in BXPC-3 after cross-talk with PSCs and reveal their potential mechanisms. The gene expression profiling analysis of BXPC-3 was completed after co-culture with primary PSCs for 48 h. The gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes pathway (KEGG) enrichment analyses were performed, and the differentially expressed genes (DEGs) were identified by Agilent GeneSpring GX software. In total, 3657 DEGs were identified in BXPC-3, including 1881 up-regulated genes and 1776 downregulated genes. GO analysis results showed that upregulated DEGs were significantly enriched in biological processes (BP), including peptide metabolic process, response to stress and electron transport chain; the downregulated DEGs were significantly enriched in biological processes, including signaling, multicellular organism development and anatomical structure development. KEGG pathway analysis revealed that 19 pathways were upregulated and 32 pathways were downregulated, and that upregulated DEGs were enriched in protein export and glutathione metabolism, while the downregulated DEGs were enriched in axon guidance and focal adhesion. The top 10 upregulated genes and the top 10 downregulated genes were identified. By constructing PPI network, we selected out 10 key genes (TP53, SRC, IL6, JUN, ISG15, CAD, STAT1, OAS3, OAS1, VIM) and significant pathways. The associated survival analysis was performed and the SRC, IL-6, ISG15, STAT1, OAS3, OAS1 and VIM were proved to be related to worse overall survival time of PDAC patients. In conclusion, the present study indicated that the identified DEGs promote our understanding of the molecular mechanisms underlying the interaction between pancreatic cancer cells and PSCs and might be used as molecular targets in the future to study the role of tumor microenvironment in the progression of PDAC.

Hormone replacement therapies, oral contraceptives, reproductive factors and colorectal adenoma risk: a systematic review and dose-response meta-analysis of observational studies

AIM

The association between the use of oral contraceptives and hormone replacement therapy (HRT) or other reproductive factors and the risk of colorectal adenoma (CRA) remains controversial. Our study aimed to review the evidence by conducting a dose-response meta-analysis to investigate this association.

METHODS

We searched PubMed and Embase databases for relevant studies published until May 2017. Traditional and dose-response meta-analyses were conducted. Sensitivity analysis was performed to evaluate the robustness of the results. Cumulative meta-analysis was used to assess the risk of different oral contraceptive formulations or generations.

RESULTS

A total of 19 observational studies, with 21 923 CRA cases and 1 030 711 participants, were included in the meta-analysis. Ever HRT use showed a potential inverse association with CRA risk [relative risk (RR) 0.83, 95% CI 0.70-1.00]. The dose-response meta-analysis further demonstrated that HRT use could reduce CRA risk. Compared with no HRT use, the predicted RRs were 0.82 (95% CI 0.67-0.99), 0.76 (95% CI 0.59-0.98) and 0.77 (95% CI 0.62-0.96) for 3, 6 and 9 years of HRT use, respectively. All other factors were not statistically significantly associated with CRA risk.

CONCLUSIONS

This study indicated that only HRT use might reduce the risk of developing CRA. Any advice regarding HRT use to prevent CRA should be tailored to the individual risks and potential benefits. Large, well-designed prospective studies with long-term follow-up are required to further clarify the aetiology of CRA.

Identification of key pathways and genes changes in pancreatic cancer cells (BXPC-3) after cross-talked with primary pancreatic stellate cells using bioinformatics analysis

Pancreatic ductal adenocarcinoma (PDAC) is one of the most malignant tumors with poor prognosis, and the interaction between activated pancreatic stellate cells (PSCs) and PDAC cells plays an important role in the development of PDAC. The aim of this study was to identify gene changes in BXPC-3 after cross-talked with PSCs and reveal their potential mechanisms. The gene expression profiling analysis of BXPC-3 was completed after co-cultured with primary PSCs for 48 h. The gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes pathway (KEGG) enrichment analyses were performed, and the differentially expressed genes (DEGs) were identified by Agilent GeneSpring GX software. In total, 3657 DEGs were identified in BXPC-3, including 1881 up-regulated genes and 1776 downregulated genes. GO analysis results showed that up-regulated DEGs were significantly enriched in biological processes (BP), including peptide metabolic process, response to stress, and electron transport chain; the down-regulated DEGs were significantly enriched in biological processes, including signaling, multicellular organismal development, and anatomical structure development. KEGG pathway analysis revealed that 19 pathways were upregulated and 32 pathways were downregulated, and that up-regulated DEGs were enriched in protein export and glutathione metabolism, while the down-regulated DEGs were enriched in axon guidance and focal adhesion. The top 10 up-regulated genes, and the top 10 down-regulated genes were identified. By constructing PPI network, we selected out 10 key genes (TP53, SRC, IL6, JUN, ISG15, CAD, STAT1, OAS3, OAS1, VIM) and significant pathways. The associated survival analysis was performed and the SRC, IL-6, ISG15, STAT1, OAS3, OAS1 and VIM were proved to be related to worse overall survival time of PDAC patients. In conclusion, the present study indicated that the identified DEGs promote our understanding of the molecular mechanisms underlying the interaction between pancreatic cancer cells and PSCs and might be used as molecular targets in the future to study the role of tumor microenvironment in the progression of PDAC.

Identification of key pathways and gene changes in primary pancreatic stellate cells after cross-talk with pancreatic cancer cells (BXPC-3) using bioinformatics analysis

It is well known that as the king of cancer, pancreatic ductal adenocarcinoma (PDAC) has relatively malignant biological behavior and poor prognosis. The interaction between pancreatic stellate cells and PDAC cells promotes the development of PDAC. The aim of this study was to describe gene characteristics in pancreatic stellate cell (PSCs) after cross-talked with BXPC-3 and unravel their underlying mechanisms. The expression profiling analysis of genes in PSCs was completed after co-cultured with primary BXPC-3 for 48h. The Kyoto Encyclopedia of Genes and Genomes pathway (KEGG) enrichment analysis and gene ontology (GO) analysis were performed, and the differentially expressed genes (DEGs) were identified by Agilent GeneSpring GX program. In total, 1804 DEGs were filtered out in PSCs, including 958 up-regulated genes and 846 downregulated genes. GO analysis showed that the up-regulated DEGs were significantly enriched in biological processes (BP) such as defense response, immune system process and immune response; the down-regulated DEGs were significantly enriched in biological regulation and cytoskeleton organization. KEGG pathway analysis showed that 28 pathways were upregulated and 5 were downregulated. By constructing PPI network, we selected out 10 key genes (IL6，IL8, IL1B, BCL2, CCL2, CSF2, KIT, ICAM1, PTPRC and IGF1) and significant enriched pathways. In conclusion, the current study suggests that the filtered DEGs contribute to our understanding of the molecular mechanisms underlying the interaction between PSCs and pancreatic cancer cells, and might be used as molecular targets to further the study the role of tumor microenvironment in the progression of PDAC.

Anal fistula plug vs rectal advancement flap for the treatment of complex cryptoglandular anal fistulas: a systematic review and meta-analysis of studies with long-term follow-up

AIM

The aim was to compare the effectiveness of the anal fistula plug (AFP) with the rectal advancement flap (RAF) for complex cryptoglandular anal fistulas.

METHODS

We conducted a literature search to identify relevant available articles published without language restriction from Embase and PubMed databases and the Cochrane Library. Studies comparing outcomes with the AFP vs RAF for complex cryptoglandular anal fistulas were eligible for inclusion.

RESULTS

A total of 11 articles with 810 patients were included in this meta-analysis. Four RCTs and one observational clinical study provided long-term follow-up. The pooled analysis of all 11 studies indicated that there was no significant difference between the AFP and RAF in terms of healing rate, recurrence rate and incidence of fistula complications. However, the pooled results of studies with long-term follow-up revealed that the RAF group had a significantly higher healing rate (OR 0.32, 95% CI 0.13, 0.78, P = 0.01) and lower recurrence rate (OR 4.45, 95% CI 1.45, 13.65, P = 0.009) than the AFP group.

CONCLUSIONS

For the treatment of complex cryptoglandular anal fistulas, the RAF was superior to the AFP in terms of healing and recurrence rate after pooling of randomized controlled trials with long-term follow-up, even though a comparison based on the pooling of all studies showed no significant difference.

[The role of the balance between Th17 and Treg in liver disease]

Naïve CD4+T cell differentiates into either Th17 or Treg in the microenvironment of various cytokines, among that, Th17 is induced by TGF-β and IL-6, while differentiates into Treg when there is only TGF-β. As the mainly transcription factors of Th17 and Treg respectively, RORγt and Foxp3 have important role in maintaining balance of Th17/Treg. Th17 and Treg are function antagonistically, so the balance of Th17/Treg means a lot for human body. Liver-a metabolic organof the body, it is susceptible to factors in vivo and in vitro. From basal hepatis to end-stage malignancy, common liver diseases are mainly including viral hepatitis, alcoholic liver disease, nonalcoholic fatty liver disease, autoimmune liver disease, hepatocellualr carcinoma and parasitic disease of liver, besides, the occurrence and development of all the diseases are correlated to the balance of Th17/Treg.

Clinical utility of quantitative dual-energy CT iodine maps and CT morphological features in distinguishing small-cell from non-small-cell lung cancer

AIM

To evaluate the clinical usefulness of quantitative dual-energy (DE) computed tomography (CT) iodine enhancement metrics combined with morphological CT features in distinguishing small-cell lung cancer (SCLC) from non-small-cell lung cancer (NSCLC).

MATERIALS AND METHODS

One hundred and six untreated lung cancer patients who underwent DECT before biopsy or surgery were prospectively enrolled. Twenty-seven routine CT descriptors, including tumour location, size, shape, margin, enhancement heterogeneity, and internal and surrounding structures, and associated findings were assessed and DECT parameters were measured in all patients. Multiple logistic regression analyses were applied to identify independent predictors of SCLC. The area under the receiver operating characteristic curve was compared between CT features combined with DECT metrics and CT features alone for distinguishing SCLC from NSCLC.

RESULTS

Histology revealed NSCLC in 80 and SCLC in 26 patients. In univariate analysis, 12 morphological CT features and two DECT metrics differed significantly between NSCLC and SCLC. When DECT parameters were combined with CT features for multivariate analysis, the independent predictors of SCLC were large tumour size, central location, confluent mediastinal lymphadenopathy, homogeneous enhancement, absence of coarse spiculation, and lower iodine density and iodine ratio (all p<0.05). The area under the receiver operating characteristic curve was improved from 0.908 to 0.981 after adding DECT metrics compared with CT features alone (p=0.007).

CONCLUSION

The combination of DECT measures and CT morphological features can be used to distinguish SCLC from NSCLC, with higher diagnostic performance compared with CT morphological features alone.

[Clinical features and diagnosis of childhood leukoencephalopathy with cerebral calcifications and cysts in four cases]

Objective: To investigate the clinical features and diagnostic bases of childhood leukoencephalopathy with cerebral calcifications and cysts (LCC). Methods: The clinical data involving manifestations and laboratory examinations of 4 children with LCC admitted to Beijing Children's Hospital Affiliated to Capital Medical University from 2012 to 2017 were retrospectively summarized. Each patient had a follow-up visit ranging from 4 months to 5 years and 9 months after initial examination. Results: Patients consisted of 2 males and 2 females, whose age of onset was respectively 2 years and 9 months, 6 years and 2 months, 7 years and 10 months, and 5 years and 1 month. The main clinical symptoms of these cases included headache, dizziness, partial seizure and claudication, and two of these cases had insidious onset. Cerebral calcifications and cysts with leukoencephalopathy were detected by neuroimaging in all patients. In addition, multifocal microhemorrhages and calcifications were observed by magnetic susceptibility-weighted imaging (SWI) series in 3 patients. Brain biopsy performed on 1 case disclosed a neuronal reduction in the cerebral cortex, loosening of focal white matter, multifocal lymphocyte infiltration, fresh hemorrhages, and gliosis, as well as angiomatous changes of blood vessels with hyalinized thicken-wall, stenotic or occlusive lumina and calcification deposits. The compound heterozygous mutations of n.*10G>A and n.82A>G in SNORD118 were identified in 1 case by target-capture next-generation sequencing. Sanger sequencing verified that the variant n.*10G>A was a novel mutation and it was of paternal-origin, while the variant n.82A>G was of maternal-origin, which had already been reported to be pathogenic to LCC. Follow-up study had shown continued partial seizure in 1 case and remissive claudication in another, while the remaining 2 cases had a relatively favorable outcome without obvious neurological symptoms at present time. Conclusions: The clinical manifestations of LCC are nonspecific, and the onset of the disease tends to be insidious. The triad neuroimaging findings of cerebral calcifications, cysts and leukoencephalopathy are essential to the diagnosis of the disease, and the signals of microhemorrhages revealed by SWI series provide another eloquent reference for the diagnosis. As biopsy is invasive and usually unavailable in the early stage, gene assessment, instead of pathological data, should be the gold standard in the diagnosis of LCC.

[Experimental observation of hyperbaric oxygen combined with radioactive seed implantation in the treatment of nude mice bearing esophageal squamous cell carcinoma]

Objective: To investigate the effect and mechanism of hyperbaric oxygen combined with radioactive seed implantation in the treatment of esophageal squamous cell carcinoma. Methods: Subcutaneous tumor model of esophageal squamous cell carcinoma using TE-8 cells was established. Tumor bearing Balb/c(nu/nu) mice (60 mice) were divided into four groups, Cont group that treated with normal oxygen level, HBO group that treated with hyperbaric oxygen, RSI group that treated with radioactive seed implantation, and HBO+ RSI group that treated with hyperbaric oxygen combined with radioactive seed implantation. Tumor volume ratio and mean survival time of tumor bearing mice were observed. Pathological changes of tumor tissue after treatment were observed by hematoxylin eosin (HE) staining. Enzyme linked immunosorbent assay kit was used to detect oxidative stress. Apoptosis related proteins were detected by Western blot. Results: After treatment, the tumor volume ratio of HBO+ RSI group was 3.51±0.80 and was significantly lower than that of Cont group, HBO group, and RSI group (P<0.05). The mean survival time of HBO+ RSI group tumor bearing mice was 62 d and was significantly longer than that in Cont group, HBO group, and RSI group (P<0.05). HE staining showed that the pathological changes of tumor tissues were most obvious in HBO+ RSI group. After treatment, the MDA and Bax levels in nude mice of HBO+ RSI group were significantly higher than those in Cont group, HBO group and RSI group, but the levels of GSH, SOD and Bcl-2 were significantly lower than those of Cont group, HBO group and RSI group (P<0.05). Conclusion: Hyperbaric oxygen combined with radioactive seed implantation could slow tumor growth and increase survival time of tumor bearing mice. The possible mechanism is that hyperbaric oxygen combined with radioactive seed implantation can improve the oxidative stress response and the expression of apoptosis protein in tumor bearing nude mice.

[Efficacy of extended-infusion of carbapenem plus sulbactam for ventilator-associated pneumonia caused by extensive drug-resistant Acinetobacter baumannii]

Objective: To evaluate the efficacy of extended-infusion of carbapenem plus sulbactam for ventilator-associated pneumonia caused by extensive drug-resistant Acinetobacter baumannii (XDRAB). Methods: Clinical data of patients with ventilator-associated pneumonia caused by XDRAB who were treated with extended-infusion carbapenem plus sulbactam or tigecycline-based therapy in Peking University First Hospital from January 2015 to December 2016 were collected and reviewed in this retrospective study. Twenty-one patients were treated with extended-infusion carbapenem plus sulbactam, and 20 other patients received tigecycline combined with other antibiotics. The general status of the patient, microbiological eradication rate, superinfection rate, new microorganism colonization rate, clinical resolution rate on the third day, clinical cure rate and mortality during treatment were compared between the two groups. Results: The two groups shared similar characteristics except that patients in the carbapenem group were younger. Microbiological eradication was not observed. Superinfections occurred in 1 patients (4.8%) in the carbapenem group and 0 patients in the tigecycline group (P=1.000), the occurrences of new microorganisms colonization were 14.3% and 25.0% respectively (P=0.638). Clinical cure were achieved in 57.1% of the patients in the carbapenem group and 50.0% of the patients in the tigecycline group (P=0.647), the clinical resolution rates on the third day were 52.4% and 45.0% respectively (P=0.636). The mortality during treatment was 9.5% in carbapenem group, and 20.0% in tigecycline group (P=0.612). No serious adverse drug reactions occurred. Conclusions: Ventilator-associated pneumonia caused by XDRAB treated with either extended-infusion carbapenem plus sulbactam or tigecycline-based therapy has a similar clinical outcome.