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.

MiR-125a-5p decreases after long non-coding RNA HOTAIR knockdown to promote cancer cell apoptosis by releasing caspase 2

HOTAIR (homeobox transcript antisense RNA), one of the prototypical long non-coding RNAs, has been verified overexpressed in multiple carcinomas and has emerged as a promising novel anticancer target. Its well-established role is acting as a predictor of poor prognosis and promoting cancer cell metastasis. Recently, another important mission of HOTAIR was uncovered that targeting HOTAIR caused cancer cell apoptosis. Nevertheless, so far there is no published data elaborating the mechanism. Here, we report that microRNA miR-125a-5p decreases and releases caspase 2 to promote cancer cell apoptosis after HOTAIR knockdown. We applied siRNAs targeting HOTAIR to various cancer cells, and observed apoptosis in all of these cell lines. RNA sequencing detected that miR-125a-5p was decreased after HOTAIR knockdown and miR-125a-5p mimics could rescue the apoptosis induced by HOTAIR deficiency. Luciferase assays identified caspase 2, an initiator caspase, to be a new target of miR-125a-5p. Elevated expression and subsequent cleavage of caspase 2 was observed after HOTAIR knockdown or inhibition of miR-125a-5p. RNAi of caspase 2 could attenuate the apoptosis induced by HOTAIR knockdown. In 80 clinical colon cancer tissues, HOTAIR and miR-125a-5p levels were higher than adjacent tissues, whereas caspase 2 was lower. MiR-125a-5p expression level was significantly correlated with colon tumor size, lymph node metastasis and clinical stage. These findings indicate that miR-125a-5p decreases after HOTAIR knockdown to promote cancer cell apoptosis by releasing caspase 2. Our work reveals a previously unidentified apoptotic mechanism, which might be exploitable in anticancer drug development.

Competitive and Predacious Interactions Among Three Phytoseiid Species Under Experimental Conditions (Acari: Phytoseiidae)

The effect of competition on species that coexist with similar ecological niches is an important theme in ecology. Furthermore, species displacement by introduced or invaded species is also an important environmental problem for biological control and conservation ecology. We tested whether two species of phytoseiids could coexist in closed cages with ample quantities of the extraguild prey species Carpoglyphus lactis (L.). Three species of phytoseiid mites-Amblyseius eharai Amitai & Swirski (a species native to China), Amblyseius swirskii (Athias-Henriot) and Neoseiulus cucumeris (Oudemans) (both species were introduced from outside of China)-were tested under experimental conditions (25 ± 1°C, 90 ± 5% relative humidity, and a photoperiod of 14:10 [L:D] h). With extraguild prey, we found that the numbers of a single population of each phytoseiid species (initial density of 10 females per cage) reached a plateau between 18 and 25 d after introduction into the experimental cages, suggesting that density-dependent factors were operating. In closed environments, one of these density-dependent factors might be cannibalism by these species. With regression analyses, Lotka-Volterra equations estimated the rate of population increase (r) and the carrying capacity (K) of each species with the data from observations on population dynamics. We next observed the interactions of two phytoseiid species with abundant extraguild prey. In all species combinations, one species went extinct and the other increased in population size, despite the availability of sufficient extraguild prey, suggesting some type of competition must have caused the extinctions. We suggested that intraguild predation is the most plausible hypothesis to explain the results.

Chinese military medical teams in the Ebola outbreak of Sierra Leone

The 2014-2015 Ebola virus disease (EVD) epidemic in West Africa was the largest in history. The three most affected countries, Guinea, Liberia and Sierra Leone, have faced enormous challenges in controlling transmission and providing clinical care for patients with EVD. The Chinese government, in response to the requests of the WHO and the governments of the affected countries, responded rapidly by deploying Chinese military medical teams (CMMTs) to the areas struck by the deadly epidemic. A total of three CMMTs, comprising 115 military medical professionals, were rotationally deployed to Freetown, Sierra Leone to assist with infection prevention and control, clinical care and health promotion and training. Between 1 October 2014 and 22 March 2015, the CMMTs in Sierra Leone admitted and treated a total of 773 suspected and 285 confirmed EVD cases. Among the 285 confirmed cases, 146 (51.2%) patients survived after treatment. In addition, the CMMTs maintained the record of zero infections among healthcare workers and zero cross-infections between quarantined patients. In this manuscript, we aim to give an overview of the mission, and share our best practices experience on predeployment preparedness, EVD holding and treatment centre building and EVD case management.

Towards a Role for Clinical Pathology Diagnostics for Childhood Maltreatment

Recent reports from the Center for Disease Control and Kaiser Permanente demonstrate that early life adverse experience leads to morbidity and mortality in adulthood. To date there are no objective tests that help care-givers or local child protective services make informed decisions for children with a history of abuse, neglect or trauma. This is the first report from a new group of trans-disciplinary investigators describing a new approach to identify the biological impact of childhood maltreatment using clinical pathology testing. Such new quantitative measurements will be useful to identify children at risk for poor mental and physical health outcomes and to follow response to interventions.

Neonatal Overfeeding in Female Mice Predisposes the Development of Obesity in their Male Offspring via Altered Central Leptin Signalling

The prevalence of obesity among child-bearing women has increased significantly. The adverse consequences of maternal obesity on the descendants have been well accepted, although few studies have examined the underlying mechanisms. We investigated whether neonatal overfeeding in female mice alters metabolic phenotypes in the offspring and whether hypothalamic leptin signalling is involved. Neonatal overfeeding was induced by reducing the litter size to three pups per litter, in contrast to normal litter size of 10 pups per litter. Normal and neonatally overfed female mice were bred with normal male mice, and offspring of overfeeding mothers (OOM) and control mothers (OCM) were generated. We examined body weight, daily food intake, leptin responsiveness and the number of positive neurones for phosphorylated-signal transducer and activator of transcription 3 (pSTAT3) along with neuropeptide Y (NPY) in the arcuate nucleus of the hypothalamus (ARH) and NPY in the nucleus tractus solitarius (NTS) of the brain stem. The body weight and daily food intake of OOM were significantly higher than those of OCM. Leptin significantly reduced food intake and increased the number of pSTAT3 positive neurones in the ARH of OCM mice, whereas no significant changes in food intake and pSTAT3 neurones were found in leptin-treated OOM mice. The number of NPY neurones in the ARH and NTS of the OOM mice was significantly higher than that of OCM mice. The results of the present study indicate that the obese phenotype from mothers can be passed onto the subsequent generation, which is possibly associated with hypothalamic leptin resistance.

Identification of aac(2')-I type b aminoglycoside-modifying enzyme genes in resistant Acinetobacter baumannii

The aim of this study was to investigate the mechanism underlying the drug resistance of Acinetobacter baumannii toward aminoglycosides. A total of 32 A. baumannii strains were identified by molecular identification and subsequently isolated. The isolates were then amplified by polymerase chain reaction to analyze the 9 aminoglycoside-modifying enzyme genes and 7 16S rRNA methylase genes. Five types of aminoglycoside-modifying enzyme genes and 1 type of 16S rRNA methylase gene were detected in the 32 drug-resistant A. baumannii strains. Positive genes included 7 detection modes, of which the all-6-gene-positive mode aac(2')-Ib+aac(3)-I+aac(6')-Ib+ant(3'')-I+aph(3')-I+armA exhibited the largest number of strains (12, 37.5%). The resistance of A. baumannii against aminoglycosides resulted from the presence of 5 types of aminoglycoside-modifying enzyme genes and the 16S rRNA methylase gene armA. This study is the first to isolate the aac(2')-Ib aminoglycoside-modifying enzyme gene from A. baumannii in a domestic clinical setting.

Association of alcohol use disorders with amyotrophic lateral sclerosis: a Swedish national cohort study

BACKGROUND AND PURPOSE

Cigarette smoking is associated with amyotrophic lateral sclerosis (ALS), but the association between alcohol consumption and ALS is not clear. Our aim was to clarify this using a national cohort study design in Sweden.

METHODS

Individuals with alcohol use disorders (AUDs) were identified from several nationwide registers, and they were linked to the Swedish Hospital Discharge and Outpatients Registers to identify the incidence of ALS. Standardized incidence ratios (SIRs) were used to examine the risk of ALS amongst individuals with AUDs compared to those without AUDs.

RESULTS

A total of 7965 patients were diagnosed with ALS during the study period 1973-2010. The incidence of ALS amongst individuals with AUD was lower compared to individuals without AUD with an overall SIR of 0.54 (95% confidence interval 0.45-0.63). The study population was further stratified by gender, educational attainment, birth country, follow-up period and a diagnosis of chronic obstructive pulmonary disease (as a proxy for smoking), and the observed inverse association between AUD and ALS was consistent for all the stratified analyses.

CONCLUSIONS

In this follow-up study, heavy alcohol consumption, as shown by registration for AUD, was inversely associated with the incidence of ALS. However, further studies are needed to disentangle the contribution of other potential confounding factors on the observed association.

A novel biomarker Linc00974 interacting with KRT19 promotes proliferation and metastasis in hepatocellular carcinoma

Location-associated long noncoding RNA (lncRNA) was reported to interact with target protein via a cis-regulatory process especially for the Flank10kb class lncRNA. Based on this theory, we aimed to explore the regulatory mechanisms of Linc00974 and KRT19 (an lncRNA beyond the Flank10kb class with protein) when we first confirmed the aberrant expression in hepatocellular carcinoma in a previous study. Knockdown of Linc00974 resulted in an inhibition of cell proliferation and invasion with an activation of apoptosis and cell cycle arrest in vitro, which was also validated by a subcutaneous and tail vein/intraperitoneal injection xenotransplantation model in vivo. We further investigated the interaction pattern of Linc00974 and KRT19. MiR-642 was identified, by acting as the competing endogenous RNA in regulating Linc00974 and KRT19. Linc00974 was increased owing to an abnormal hypomethylation promoter, which induced the upregulation of KRT19 via ceRNA interaction, resulting in the activation of the Notch and TGF-β pathways as detected by cDNA microarray. We also discovered Linc00974F-1 stably expressed in the plasma. By the combined analysis of Linc00974F-1 with CYFRA21-1, we found that these joint indicators predicted growth and metastasis of tumor in HCC patients. In conclusion, the combination of Linc00974 and KRT19 may be novel indices for clinical diagnosis of tumor growth and metastasis in HCC, while Linc00974 may become a potential therapeutic target for the prevention of HCC progression.

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.

Hodgkin lymphoma after autoimmune diseases by age at diagnosis and histological subtype

BACKGROUND

Increased risk of Hodgkin lymphoma (HL) associated with personal history of several autoimmune diseases (ADs), such as rheumatoid arthritis, systemic lupus erythematosus, sarcoidosis, and immune thrombocytopenic purpura, are known. Whether there are other HL-related ADs and whether the increased risk of HL after ADs holds across sex, age, year of diagnosis, or HL histological subtype is unclear.

PATIENTS AND METHODS

We systematically analyzed the risk of HL in 878 161 Swedish patients diagnosed with 33 different ADs in 1964-2010. During ∼10-year follow-up of ADs patients, 371 incident HL cases were diagnosed.

RESULTS

Significantly increased overall standardized incidence ratio (SIR) for HL after ADs was 2.0 (95% confidence interval: 1.8-2.2); AD-specific SIRs: autoimmune hemolytic anemia 19.9 (7.2-43.6), sarcoidosis 10.3 (7.8-13.4), systemic lupus erythematosus 8.4 (5.2-12.9), immune thrombocytopenic purpura 7.0 (3.2-13.3), polyarteritis nodosa 6.6 (1.2-19.5), polymyositis/dermatomyositis 6.3 (2.0-14.9), Behcet's disease 5.6 (2.7-10.3), Sjögren's syndrome 5.0 (2.1-9.8), rheumatoid arthritis 3.2 (2.6-3.9), polymyalgia rheumatica 2.2 (1.4-3.5), and psoriasis 1.9 (1.3-2.6). Men with AD had slightly higher risk of HL (2.4, 2.0-2.7) compared with women (1.8, 1.5-2.0). Only 23% of ADs were diagnosed before age 35 years and the overall SIR for HL diagnosis before age 35 [1.4, (1.0-1.8)] was lower than that in older ages [35 ≤ age < 50: 2.1 (1.6-2.7); age ≥ 50: 2.2 (2.0-2.5)], except for sarcoidosis [age < 35: 19.3 (10.5-32.5); 35 ≤ age < 50: 10.4 (5.7-17.5); age ≥ 50: 8.4 (5.6-12.1)]. Risks of all classical HLs significantly increased after ADs: lymphocyte depletion 3.7 (1.5-7.6), lymphocyte-rich 3.7 (2.3-5.9), mixed cellularity 2.4 (1.8-3.2), and nodular sclerosis 1.7 (1.3-2.1).

CONCLUSION

Several, but not all ADs (11/33), had a positive association with all classical histological subtypes of HL. Higher risks of classical HL after polyarteritis nodosa, polymyositis/dermatomyositis, Behcet's disease, Sjögren's syndrome, polymyalgia rheumatica, and psoriasis were novel findings of this study.

Diagnostic values of carcinoembryonic antigen in predicting peritoneal recurrence after curative resection of gastric cancer: a meta-analysis

AIM

A meta-analysis was performed to assess the diagnostic values of carcinoembryonic antigen (CEA) in predicting the peritoneal recurrence after curative resection of gastric cancer.

METHODS

The Medline, Embase, Web of Science, Ovid and Cochrane databases, Google Scholar and Vivisimo engines were searched to identify studies reporting on the accuracy of CEA protein or CEA mRNA in predicting the postoperative peritoneal recurrence of gastric cancer. Publication bias was demonstrated by Funnel plots and Egger test. The sensitivity, specificity, and diagnostic odds ratio (DOR) were calculated and summary receiver operating characteristic curves were generated.

RESULTS

Seven and eight studies fulfilled the inclusion criteria for CEA protein and mRNA determination, including 635 and 849 patients, respectively. The pooled sensitivity, specificity and DOR of CEA protein for predicting the peritoneal recurrence were 0.77 (95 % CI 0.69-0.84), 0.89 (95 % CI 0.86-0.92), 29.71 (95 % CI 10.27-85.92), respectively. Similarly, the values for CEA mRNA were 0.82 (95 % CI 0.75-0.88), 0.82 (95 % CI 0.79-0.85) and 22.97 (95 % CI 10.90-48.41). Meanwhile, the sensitivity and DOR of CEA protein or mRNA were higher than those of cytology, while higher specificity was noted in cytology assay.

CONCLUSION

CEA protein and mRNA levels in peritoneal lavage show a high diagnostic accuracy and may help accurately predict the peritoneal recurrence after curative resection of gastric cancer.

Prevalence of carbapenem-hydrolyzing class D β-lactamase genes in Acinetobacter spp. isolates in China

In order to assess the prevalence of carbapenem-hydrolyzing class D β-lactamase genes in Acinetobacter spp. isolates in China, we conducted a polymerase chain reaction (PCR)-based surveillance of OXA-type β-lactamase gene clusters for a total of 2,880 Acinetobacter spp. isolates collected from 23 Chinese provinces. All isolates were tested for susceptibility to 12 antimicrobial agents and showed high rates of resistance to all these agents except minocycline. We also found that the vast majority of carbapenem-resistant Acinetobacter spp. were OXA-23-like-producing isolates, predominantly Acinetobacter baumannii isolates. Besides, bla OXA-58-like and bla OXA-24-like genes were detected in 32 and 11 isolates, respectively, involving many provinces throughout China. Furthermore, these two carbapenem-resistance determinants were located on transferable plasmids in most cases, indicating an emerging threat for both OXA-58-like- and OXA-24-like-producing Acinetobacter spp. isolates in China. Interestingly, a novel homologue of the bla OXA-143 gene was identified in a susceptible Acinetobacter pittii isolate. Overall, these observations suggest that the bla OXA-23-harboring A. baumannii isolates are the most frequent carbapenem-resistant Acinetobacter spp. in China, and the bla OXA-24-like and bla OXA-58-like genes have emerged as potential threats of hospital outbreaks of multidrug-resistant Acinetobacter spp.

Death-associated protein-3, DAP-3, correlates with preoperative chemotherapy effectiveness and prognosis of gastric cancer patients following perioperative chemotherapy and radical gastrectomy

Background:

DAP3 is a member of the death-associated protein (DAP) family and is characterised by proapoptotic function. It is involved in both exogenous and endogenous apoptotic pathways. In our previous studies, apoptotic level was found to be correlated with the effectiveness of preoperative chemotherapy. The effectiveness of preoperative chemotherapy was also associated with the overall effectiveness of the combined therapy and prognosis. The present study aimed to investigate the role of DAP3 in the evaluation of preoperative chemotherapy effectiveness and its ability to predict prognosis in gastric cancer.

Methods:

Quantitative PCR and immunohistochemistry staining were performed in 87 patients who received combined therapy. Knockdown of DAP3 was conducted in gastric cancer cell lines to investigate its impact on cell growth, migration, adhesion and invasion. Tolerance to chemotherapy agents was determined by assessing apoptosis and caspase-3.

Results:

Higher DAP3 expression in gastric tumours was correlated with better prognosis. Knockdown of DAP3 expression promoted cell migration and enhanced resistance to chemotherapy by inhibiting apoptosis.

Conclusion:

DAP3 is a potential molecular marker for response to preoperative chemotherapy and for predicting prognosis in gastric cancer patients treated with neoadjuvant chemotherapy and gastrectomy.