Sub-50 nm core-shell nanoparticles with the pH-responsive squeezing release effect for targeting therapy of hepatocellular carcinoma.

The development of drug delivery systems with high drug loading capacity, low leakage at physiological pH, and rapid release at the lesion sites remains an ongoing challenge. In this work, core-shell poly(6-O-methacryloyl-D-galactose)@poly(tert-butyl methacrylate) (PMADGal@PtBMA) nanoparticles (NPs) of sub-50 nm are facilely synthesized by reversible addition-fragmentation chain transfer (RAFT) soap-free emulsion polymerization with the assistance of 12-crown-4. A hydrophilic poly(methacrylic acid) (PMAA) core can then be revealed after deprotection of the tert-butyl groups, which is negatively charged and can adsorb nearly 100% of incubated doxorubicin (DOX) from a solution at pH 7.4. The physical shrinkage of PMAA chains below pH 6.0 endows the core with the squeezing effect, therefore realizing rapid drug release. It is demonstrated that the DOX release rate of PMADGal@PMAA NPs at pH 5 was 4 times that at pH 7.4. Cellular uptake experiments confirm the high targeting ability of the galactose modified PMADGal shell to human hepatocellular carcinoma (HepG2) cells. The fluorescence intensity of DOX in HepG2 cells is 4.86 times that of HeLa cells after 3 h incubation. Moreover, 20% cross-linked NPs show the highest uptake efficiency by HepG2 cells due to their moderate surface charge, size and hardness. In summary, both the core and the shell of PMADGal@PMAA NPs promise the rapid site-specific release of DOX in HepG2 cells. This work provides a facile and an effective strategy to synthesize core-shell NPs for hepatocellular carcinoma targeting therapy.

Galactosylated Core-Shell Nanoparticles with pH/GSH Dual Sensitivity for Targeting Hepatocellular Carcinoma.

Galactosylated core-shell nanoparticles (NPs) with diameters of sub-50 nm were fabricated in one pot by reversible addition-fragmentation chain transfer (RAFT) soap-free emulsion polymerization. Their galactosylated shells and acidic cores endow them with high targeting and drug loading efficiencies, respectively. Morever, the physical shrinkage and cleavage of the disulfide cross-linked NPs can realize the rapid release of loaded doxorubicin (DOX) under pH 5.0 and reduced glutathione (GSH) conditions. The combination of these excellent properties resulted in an even lower IC50 of DOX-loaded NPs than free DOX, demonstrating that this platform would be promising in targeting the therapy of hepatocellular carcinoma.

Novel Tumor-Specific Antigens for Immunotherapy Identified From Multi-omics Profiling in Thymic Carcinomas.

Thymic carcinoma (TC) is the most aggressive thymic epithelial neoplasm. TC patients with microsatellite instability, whole-genome doubling, or alternative tumor-specific antigens from gene fusion are most likely to benefit from immunotherapies. However, due to the rarity of this disease, how to prioritize the putative biomarkers and what constitutes an optimal treatment regimen remains largely unknown. Therefore, we integrated genomic and transcriptomic analyses from TC patients and revealed that frameshift indels in KMT2C and CYLD frequently produce neoantigens. Moreover, a median of 3 fusion-derived neoantigens was predicted across affected patients, especially the CATSPERB-TC2N neoantigens that were recurrently predicted in TC patients. Lastly, potentially actionable alterations with early levels of evidence were uncovered and could be used for designing clinical trials. In summary, this study shed light on our understanding of tumorigenesis and presented new avenues for molecular characterization and immunotherapy in TC.

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OBJECTIVES: To study the clinical features and outcome of very preterm infants withdrawn from caffeine citrate at different time points. METHODS: A retrospective analysis was performed on the medical data of the preterm infants with a gestational age of <32 weeks, who were hospitalized in the Division of Neonatology, the Second Xiangya Hospital of Central South University, from January 1, 2016 to November 30, 2020. According to the time of withdrawal from caffeine citrate, the infants who met the study criteria were divided into the group with withdrawal before the last week of hospitalization and the group with withdrawal within the last week of hospitalization. The two groups were compared in terms of clinical features, features of citric caffeine use, length of hospital stay and hospital costs, change in the intensity of respiratory support, and preterm complications. RESULTS: A total of 403 preterm infants were enrolled, with 285 infants in the group with withdrawal before the last week of hospitalization and 118 infants in the group with withdrawal within the last week of hospitalization. There were no significant differences in clinical features between the two groups (P>0.05). Compared with the group with withdrawal before the last week of hospitalization, the group with withdrawal within the last week of hospitalization had a significantly longer duration of the use of caffeine citrate, a significantly shorter length of hospital stay, a significantly lower rate of increased intensity of respiratory support after withdrawal, and a significantly lower incidence rate of moderate or severe bronchopulmonary dysplasia (P<0.05). CONCLUSIONS: A relatively long course of caffeine citrate treatment is more beneficial to the short-term clinical outcome of very preterm infants.

High frequency ultrasound-guided pericardiocentesis performed in the sitting position: A novel apical approach.

BACKGROUND: So far, few approaches have been described to reduce inadvertent injury to structure of the heart and nearby organs in percutaneous pericardiocentesis. HYPOTHESIS: We hypothesized that an in-plane high frequency ultrasound-guided apical approach, performed in the sitting position, would provide additional benefits in terms of feasibility and safety for draining malignant pericardial effusion (MPE). METHODS: The authors selected 53 consecutive patients with moderate or large symptomatic MPE who underwent high frequency ultrasound-guided pericardiocentesis. After the procedure, all patients were followed for 90 days with the main purpose of detecting procedure success, procedure-related complications, and recurrent PE. RESULTS: Procedure success rate for pericardiocentesis was 100%. All patients were placed in the sitting position with their left hands extended above the heads. An apical puncture approach was performed in all cases (100%). The mean duration of catheter drainage was 8.1 ± 3.2 days. The mean initial amount of pericardial fluid drained was 956.3 ± 687.5 ml. Overall, six patients (11%) had recurrent PE; 3 (6%) had repeated percutaneous pericardiocentesis. There was no major complication and minor complications occurred in four patients (8%). CONCLUSION: This novel in-plane high frequency US-guided apical approach has several advantages for percutaneous pericardiocentesis of MPE: performed in the sitting position; a benefit for patients with orthopnea; a maximum inserted wide angle to prevent damage to the myocardium; local enlargement of the PE region; high procedure success rate of pericardiocentesis; and excellent clinical outcomes.

Altered Functional Connectivity of Amygdala with the Fronto-Limbic-Striatal Circuit in Temporal Lobe Lesion as a Proposed Mechanism for Poststroke Depression.

OBJECTIVE: Poststroke depression (PSD) is an important complication that affects stroke rehabilitation. Abnormal cortical-subcortical connectivity may be associated with the development of PSD. However, few studies have focused on the emotional network of PSD in the temporal lobe lesions. The aim of is study was to investigate amygdala-cortical functional connectivity (FC) in the temporal lobe in individuals with and without PSD. DESIGN: Twenty-three patients with PSD and 21 stroke patients without depression were recruited to undergo functional magnetic imaging scanning. RESULTS: In stroke patients with depression, the left amygdala had increased FC with the bilateral precuneus and right orbital frontal lobe but decreased FC with the right putamen. The right amygdala had increased FC with the right temporal pole, right rectus gyrus, and left orbital frontal lobe but decreased FC with the right primary sensory area (S1). Correlative analyses revealed that the amygdala's FCs with the right orbital frontal lobe, right insular cortex, and right cingulate cortex were correlated with the Hamilton Depression Rating Scale score. CONCLUSION: The current study identified mood affected through the fronto-limbic-striatal circuit in PSD. Hyperconnectivity between the amygdala, default mode network, and salience network might be related to depressive symptoms, which may provide novel insight into the underlying neuropathologic mechanisms of PSD in temporal lobe lesions.

High Rates of Human Fecal Carriage of mcr-1-Positive Multidrug-Resistant Enterobacteriaceae Emerge in China in Association With Successful Plasmid Families.

Background: mcr-1-mediated colistin resistance in Enterobacteriaceae is concerning, as colistin is used in treating multidrug-resistant Enterobacteriaceae infections. We identified trends in human fecal mcr-1-positivity rates and colonization with mcr-1-positive, third-generation cephalosporin-resistant (3GC-R) Enterobacteriaceae in Guangzhou, China, and investigated the genetic contexts of mcr-1 in mcr-1-positive 3GC-R strains. Methods: Fecal samples were collected from in-/out-patients submitting specimens to 3 hospitals (2011-2016). mcr-1 carriage trends were assessed using iterative sequential regression. A subset of mcr-1-positive isolates was sequenced (whole-genome sequencing [WGS], Illumina), and genetic contexts (flanking regions, plasmids) of mcr-1 were characterized. Results: Of 8022 fecal samples collected, 497 (6.2%) were mcr-1 positive, and 182 (2.3%) harbored mcr-1-positive 3GC-R Enterobacteriaceae. We observed marked increases in mcr-1 (0% [April 2011] to 31% [March 2016]) and more recent (since January 2014; 0% [April 2011] to 15% [March 2016]) increases in human colonization with mcr-1-positive 3GC-R Enterobacteriaceae (P < .001). mcr-1-positive 3GC-R isolates were commonly multidrug resistant. WGS of mcr-1-positive 3GC-R isolates (70 Escherichia coli, 3 Klebsiella pneumoniae) demonstrated bacterial strain diversity; mcr-1 in association with common plasmid backbones (IncI, IncHI2/HI2A, IncX4) and sometimes in multiple plasmids; frequent mcr-1 chromosomal integration; and high mobility of the mcr-1-associated insertion sequence ISApl1. Sequence data were consistent with plasmid spread among animal/human reservoirs. Conclusions: The high prevalence of mcr-1 in multidrug-resistant E. coli colonizing humans is a clinical threat; diverse genetic mechanisms (strains/plasmids/insertion sequences) have contributed to the dissemination of mcr-1, and will facilitate its persistence.

MicroRNA-4458 suppresses the proliferation of human lung cancer cells in vitro by directly targeting Lin28B.

Previous studies have shown that the expression of microRNA-4458 (miR-4458) is dysregulated in hepatocellular carcinoma and colon cancer. In this study, we investigated the direct target of miR-4458 and its biological functions in human lung cancer cells. By using the database TargetScan, we identified Lin28B, an oncogene, as a direct target gene of miR-4458. In dual-luciferase reporter assay, we found that miR-4458 mimics dose-dependently inhibited the luciferase activity of the wild-type 3'UTR of Lin28B in human lung cancer A549 and NCI-H1299 cell lines without affecting its mutant forms, whereas anti-miR-4458, an inhibitor of miR-4458, dose-dependently promoted the luciferase activity of the wild-type 3'UTR of Lin28B in A549 and NCI-H1299 cell lines without affecting its mutant forms. Overexpression of miR-4458 significantly decreased the protein levels of Lin28B in the cells, and inhibited the cell growth and colony formation. Conversely, knockdown of miR-4458 with anti-miR-4458 significantly increased the protein levels of Lin28B, and promoted the cell proliferation, which could be reverted by knockdown of Lin28B expression. In addition, we detected the expression of Lin28B using RT-PCR in 40 human lung cancer tissues and matched peritumoral tissues, and found that Lin28B was overexpressed in lung cancer tissues and negatively correlated with miR-4458 expression (r=-0.694, P<0.05). We conclude that miR-4458 is a tumor suppressor, and Lin28B is the direct target of miR-4458. These results suggest the modulation of miR-4458/Lin28B expression offers a potential therapeutic strategy for lung cancer.

Characterization of CTX-M-140, a Variant of CTX-M-14 Extended-Spectrum ß-Lactamase with Decreased Cephalosporin Hydrolytic Activity, from Cephalosporin-Resistant Proteus mirabilis.

CTX-M-140, a novel CTX-M-type extended-spectrum ß-lactamase (ESBL), was identified in cephalosporin-resistant clinical isolates of Proteus mirabilis CTX-M-140 contained an alanine-to-threonine substitution at position 109 compared to its putative progenitor, CTX-M-14. When it was expressed in an Escherichia coli isogenic background, CTX-M-140 conferred 4- to 32-fold lower MICs of cephalosporins than those with CTX-M-14, indicating that the phenotype was attributable to this single substitution. For four mutants of CTX-M-14 that were constructed by site-directed mutagenesis (A109E, A109D, A109K, and A109R mutants), MICs of cephalosporins were similar to those for the E. coli host strain, which suggested that the alanine at position 109 was essential for cephalosporin hydrolysis. The kinetic properties of native CTX-M-14 and CTX-M-140 were consistent with the MICs for the E. coli clones. Compared with that of CTX-M-14, a lower hydrolytic activity against cephalosporins was observed for CTX-M-140. blaCTX-M-140 is located on the chromosome as determined by I-CeuI pulsed-field gel electrophoresis (I-CeuI-PFGE) and Southern hybridization. The genetic environment surrounding blaCTX-M-140 is identical to the sequence found in different plasmids with blaCTX-M-9-group genes among the Enterobacteriaceae Genome sequencing and analysis showed that P. mirabilis strains with blaCTX-M-140 have a genome size of ∼4 Mbp, with a GC content of 38.7% and 23 putative antibiotic resistance genes. Our results indicate that alanine at position 109 is critical for the hydrolytic activity of CTX-M-14 against oxyimino-cephalosporins.

MLVA and MLST typing of Brucella from Qinghai, China.

BACKGROUND: The Qinghai-Tibet Plateau (QTP) of China is an extensive pastoral and semi-pastoral area, and because of poverty and bad hygiene conditions, Brucella is highly prevalent in this region. In order to adequately prevent this disease in the QTP region it is important to determine the identity of Brucella species that caused the infection. METHODS: A total of 65 Brucella isolates were obtained from human, livestock and wild animals in Qinghai, a Chinese province in east of the QTP. Two molecular typing methods, MLVA (multi-locus variable-number tandem-repeat analysis) and MLST (multi locus sequence typing) were used to identify the species and genotypes of these isolates. FINDINGS: Both MLVA and MLST typing methods classified the 65 isolates into three species, B. melitensis, B. abortus and B. suis, which included 60, 4 and 1 isolates respectively. The MLVA method uniquely detected 34 (Bm01 ~ Bm34), 3 (Ba01 ~ Ba03), and 1 (Bs01) MLVA-16 genotypes for B. melitensis, B. abortus and B. suis, respectively. However, none of these genotypes exactly matched any of the genotypes in the Brucella2012 MLVA database. The MLST method identified five known ST types: ST7 and ST8 (B. melitensis), ST2 and ST5 (B. abortus), and ST14 (B. suis). We also detected a strain with a mutant type (3-2-3-2-?-5-3-8-2) of ST8 (3-2-3-2-1-5-3-8-2). Extensive genotype-sharing events could be observed among isolates from different host species. CONCLUSIONS: There were at least three Brucella (B. melitensis, B. abortus and B. suis) species in Qinghai, of which B. melitensis was the predominant species in the area examined. The Brucella population in Qinghai was very different from other regions of the world, possibly owing to the unique geographical characteristics such as extremely high altitude in QTP. There were extensive genotype-sharing events between isolates obtained from humans and other animals. Yaks, sheep and blue sheep were important zoonotic reservoirs of brucellosis causing species found in humans.

NDM-1-Producing Citrobacter freundii, Escherichia coli, and Acinetobacter baumannii Identified from a Single Patient in China.

We identified New Delhi metallo-ß-lactamase (NDM-1)-producing Citrobacter freundii GB032, Escherichia coli GB102, and Acinetobacter baumannii GB661 in urine and stool samples from a single patient in China. Plasmid profiling and Southern blotting indicated that blaNDM-1 from GB032 and that from GB102 were likely located on the same plasmid, while blaNDM-1 from GB661 was located on a very large (>400-kb) plasmid. This case underscores the broad host range of blaNDM-1 and its potential to spread between members of the family Enterobacteriaceae and A. baumannii.

CTX-M-137, a hybrid of CTX-M-14-like and CTX-M-15-like ß-lactamases identified in an Escherichia coli clinical isolate.

OBJECTIVES: To characterize a novel CTX-M chimera, CTX-M-137, from Escherichia coli clinical isolates in China. METHODS: Isolates were collected from five hospitals between 22 February 2009 and 20 December 2011. Resistance genes were investigated by PCR. blaCTX-M-137 was cloned and purified for kinetic measurements. Conjugation experiments, S1-PFGE and Southern blotting were performed to study the plasmid harbouring blaCTX-M-137. The genetic environment of blaCTX-M-137 was determined by genomic cloning and sequencing. RESULTS: A total of 247 cephalosporin-resistant E. coli were identified. blaCTX-M group genes were the most prevalent extended-spectrum ß-lactamase (ESBL) genes, with 71 isolates harbouring blaCTX-M-1 group genes and 137 isolates harbouring blaCTX-M-9 group genes. A novel chimera of CTX-M-14-like and CTX-M-15-like ESBLs, designated CTX-M-137, was identified from a 60-year-old man with a urinary tract infection. The N-terminus of CTX-M-137 matched CTX-M-14 and the C-terminus matched CTX-M-15. CTX-M-137 conferred resistance to ceftazidime, cefotaxime and aztreonam. Purified CTX-M-137 showed good hydrolytic activity against ceftazidime and cefotaxime, and was inhibited by clavulanic acid. The blaCTX-M-137 was carried on an ∼83 kb IncI1 plasmid. blaCTX-M-137 was carried on a complete transposition unit ISEcp1-blaCTX-M-137-Δorf477 inserted into yagA, which is part of the IncI1 plasmid backbone. CONCLUSIONS: We identified a novel CTX-M chimera, CTX-M-137, with a CTX-M-14-like N-terminus and a CTX-M-15-like C-terminus. Our findings suggest an ongoing diversification of CTX-M-type ESBLs through recombination events.

Association of the MS4A2 gene promoter C-109T or the 7th exon E237G polymorphisms with asthma risk: a meta-analysis.

BACKGROUND AND OBJECTIVE: A large number of studies have examined the association between the Membrane-spanning 4 domains, superfamily A, number 2 (MS4A2) gene C-109T (rs1441586) or E237G (rs569108) variants and asthma risk. However, the results are inconsistent and inconclusive. To derive a more precise estimation, a meta-analysis was performed. METHODS: Meta-analyses were conducted with the data from case-control association studies (24 studies with 4496 asthmatics and 4571 controls for E237G variant and 9 studies including 2005 cases and 1868 control for C-109T polymorphisms, respectively). Random-effects model was used to calculate summary odds ratios (ORs). RESULTS: For the MS4A2 gene E237G variant, no significant associations with asthma were found in overall population; we observed an elevated risk of atopic asthma among subjects with the 237G allele (OR=1.341, 95% CI: 1.039-1.732 for G versus E and OR=1.374, 95% CI: 1.032-1.828 for EG+GG versus EE) in the stratified meta-analysis. As for the MS4A2 gene C-109T polymorphism, no significant associations with asthma risk were observed in the total population; in subgroup analysis by ethnicity of subjects we found increased asthma risk among Asians carrying T allele (OR=1.140, 95% CI: 1.019-1.276 for T versus C and OR=1.359, 95% CI: 1.029-1.794 for TT versus CC). CONCLUSIONS: Data indicated that the MS4A2 gene E237G variant may be a risk factor for developing atopic asthma and the promoter -109T allele is a potential risk factor of asthma in Asians.

Outbreak of PER-1 and diversity of ß-lactamases among ceftazidime-resistant Pseudomonas aeruginosa clinical isolates.

A growing number of ß-lactamases have been reported in Pseudomonas aeruginosa clinical isolates. The aim of this study was to investigate the diversity of ß-lactamases in the collection of 51 ceftazidime-resistant P. aeruginosa clinical isolates in four hospitals of southern China. Among these isolates, variable degrees of resistance to other ß-lactam and non-ß-lactam agents were observed. Pulsed-field gel electrophoresis (PFGE) revealed a high degree of clonality with five main genotypes. Of the 51 isolates tested, 35 (68.6%) were identified as extended-spectrum ß-lactamase (ESBL) producers, with 35 producing PER-1, 1 CTX-M-3, 7 CTX-M-15 and 1 CTX-M-14. Most (82.9%, 29/35) PER-1-producing isolates were collected from two hospitals between January and April in 2008 and belonged to the same PFGE pattern (pattern B) with similar antibiogram and ß-lactamase profiles, which suggested an outbreak of this clone at the time. The prevalence of CTX-M-type ESBL (17.6%, 9/51) was unexpectedly high. One isolate was identified as producing VIM-2. Furthermore, we also reported an occurrence of a novel OXA-10 variant, OXA-246, in 14 P. aeruginosa isolates. In addition, AmpC overproduction was found to be the ß-lactamase-mediated mechanism responsible for ceftazidime resistance in 6 isolates (11.8%). Our results revealed an overall diversity of ß-lactamases and outbreak of a PER-1-producing clone among ceftazidime-resistant P. aeruginosa in southern China.

[X-ray powder diffraction of clay minerals of SZK01 core of Zabuye Lake, Tibetan Plateau].

The present article chooses the core from the borehole SZK01 in Zabuye Lake as the main research object. According to the results of X-ray powder diffraction of clay minerals, the major components are illite, illite and smectite mixed layer mineral (I/S), kaolinite and chlorite. According to the different species and contents of clay, integration of the characteristics of mineral and the results of Δ18O, we reestablished the evolution process of paleoclimate in Zabuye Lake. In compaison with SZK02 core in Zabuye, Greenland GISP2 and GRIP and Guliya ice core, it contains 5 stages since 115 ka in Zabuye: the last interglacial (15-75.5 ka), the earlier last glacial (75.5-60 ka), the interstage of the last glacial (60-30.1 ka), the last glacial maximum (30.1-16.7 ka) and deglacial-holocene (since 16.7 ka). We also recognized 6 Heinrich events (H1-H6) and warm event in 71 ka. In particular, the content of kaolinite is low, with the negative-skewed value of Δ18O in 52-53 ka, while the value of Δ18O in SZK02 and Guliya ice core is negative-skewed too, indicating the cold event in Tibet plateau, named H5-1. All the above demonstrated that the climate in Tibet plateau is global since the earlier last glacial, and it also has regional characteristics.

[Infections of the head and neck leading to descending necrotizing mediastinitis: management of 9 cases].

OBJECTIVE: To report nine cases of descending necrotizing mediastinitis (DNM) and to summarize the management experience. METHODS: Between December 2005 and December 2008, nine patients (mean age, 55.7 years; age range, 38 to 78 years) with DNM were treated. Eight patients underwent surgical drainage of the involved cervical region and mediastinum (4 with cervical drainage alone; 4 with cervical drainage and right thoracotomy). RESULTS: Two patients died, one of them refused surgical therapy and the other one died of multiorgan failure related to postoperative septic shock. Seven patients recovered. The mortality rate was 22%. CONCLUSIONS: Delayed diagnosis and inadequate drainage are the main causes of high mortality rate of DNM. Aggressive surgical drainage and debridement of the neck and mediastinum by a multidisciplinary team of surgeons are very important in the treatment of DNM.