Bacterial antibiotic resistance among cancer inpatients in China: 2016-20

BACKGROUND

The incidence of infections among cancer patients is as high as 23.2-33.2% in China. However, the lack of information and data on the number of antibiotics used by cancer patients is an obstacle to implementing antibiotic management plans.

AIM

This study aimed to investigate bacterial infections and antibiotic resistance in Chinese cancer patients to provide a reference for the rational use of antibiotics.

DESIGN

This was a 5-year retrospective study on the antibiotic resistance of cancer patients.

METHODS

In this 5-year surveillance study, we collected bacterial and antibiotic resistance data from 20 provincial cancer diagnosis and treatment centers and three specialized cancer hospitals in China. We analyzed the resistance of common bacteria to antibiotics, compared to common clinical drug-resistant bacteria, evaluated the evolution of critical drug-resistant bacteria and conducted data analysis.

FINDINGS

Between 2016 and 2020, 216 219 bacterial strains were clinically isolated. The resistance trend of Escherichia coli and Klebsiella pneumoniae to amikacin, ciprofloxacin, cefotaxime, piperacillin/tazobactam and imipenem was relatively stable and did not significantly increase over time. The resistance of Pseudomonas aeruginosa strains to all antibiotics tested, including imipenem and meropenem, decreased over time. In contrast, the resistance of Acinetobacter baumannii strains to carbapenems increased from 4.7% to 14.7%. Methicillin-resistant Staphylococcus aureus (MRSA) significantly decreased from 65.2% in 2016 to 48.9% in 2020.

CONCLUSIONS

The bacterial prevalence and antibiotic resistance rates of E. coli, K. pneumoniae, P. aeruginosa, A. baumannii, S. aureus and MRSA were significantly lower than the national average.

Light-Induced Renormalization of the Dirac Quasiparticles in the Nodal-Line Semimetal ZrSiSe

In nodal-line semimetals, linearly dispersing states form Dirac loops in the reciprocal space with a high degree of electron-hole symmetry and a reduced density of states near the Fermi level. The result is reduced electronic screening and enhanced correlations between Dirac quasiparticles. Here we investigate the electronic structure of ZrSiSe, by combining time- and angle-resolved photoelectron spectroscopy with ab initio density functional theory (DFT) complemented by an extended Hubbard model (DFT+U+V) and by time-dependent DFT+U+V. We show that electronic correlations are reduced on an ultrashort timescale by optical excitation of high-energy electrons-hole pairs, which transiently screen the Coulomb interaction. Our findings demonstrate an all-optical method for engineering the band structure of a quantum material.

One-dimensional flat bands in twisted bilayer germanium selenide

Experimental advances in the fabrication and characterization of few-layer materials stacked at a relative twist of small angle have recently shown the emergence of flat energy bands. As a consequence electron interactions become relevant, providing inroads into the physics of strongly correlated two-dimensional systems. Here, we demonstrate by combining large scale ab initio simulations with numerically exact strong correlation approaches that an effective one-dimensional system emerges upon stacking two twisted sheets of GeSe, in marked contrast to all moiré systems studied so far. This not only allows to study the necessarily collective nature of excitations in one dimension, but can also serve as a promising platform to scrutinize the crossover from two to one dimension in a controlled setup by varying the twist angle, which provides an intriguing benchmark with respect to theory. We thus establish twisted bilayer GeSe as an intriguing inroad into the strongly correlated physics of lowdimensional systems.

The High Mobility Group A1 (HMGA1) Transcriptome in Cancer and Development

BACKGROUND & OBJECTIVES

Chromatin structure is the single most important feature that distinguishes a cancer cell from a normal cell histologically. Chromatin remodeling proteins regulate chromatin structure and high mobility group A (HMGA1) proteins are among the most abundant, nonhistone chromatin remodeling proteins found in cancer cells. These proteins include HMGA1a/HMGA1b isoforms, which result from alternatively spliced mRNA. The HMGA1 gene is overexpressed in cancer and high levels portend a poor prognosis in diverse tumors. HMGA1 is also highly expressed during embryogenesis and postnatally in adult stem cells. Overexpression of HMGA1 drives neoplastic transformation in cultured cells, while inhibiting HMGA1 blocks oncogenic and cancer stem cell properties. Hmga1 transgenic mice succumb to aggressive tumors, demonstrating that dysregulated expression of HMGA1 causes cancer in vivo. HMGA1 is also required for reprogramming somatic cells into induced pluripotent stem cells. HMGA1 proteins function as ancillary transcription factors that bend chromatin and recruit other transcription factors to DNA. They induce oncogenic transformation by activating or repressing specific genes involved in this process and an HMGA1 "transcriptome" is emerging. Although prior studies reveal potent oncogenic properties of HMGA1, we are only beginning to understand the molecular mechanisms through which HMGA1 functions. In this review, we summarize the list of putative downstream transcriptional targets regulated by HMGA1. We also briefly discuss studies linking HMGA1 to Alzheimer's disease and type-2 diabetes.

CONCLUSION

Further elucidation of HMGA1 function should lead to novel therapeutic strategies for cancer and possibly for other diseases associated with aberrant HMGA1 expression.

RANTES and SDF-1 Are Keys in Cell-based Therapy of TMJ Osteoarthritis

The present study aimed to investigate the therapeutic effect of injections of local bone marrow mesenchymal stem cells (BMSCs) on osteoarthritis (OA) of the temporomandibular joint (TMJ) and to explore the role of stromal cell-derived factor 1 (SDF-1) and regulated on activation, normal T-cell expressed and secreted (RANTES) in this effect. Fundamentally, OA of the TMJ was induced by unilateral anterior crossbite in mice. Exogenous green fluorescent protein-labeled BMSCs (GFP-BMSCs) were weekly injected into the TMJ region for 4, 8, and 12 wk. The reparative effects of exogenous GFP-BMSCs were investigated by morphological observation and micro-computed tomography. The differentiation of GFP-BMSCs in the cartilage was examined by double immunofluorescence of GFPs with type II collagen, and the expression of related factors in the condylar cartilage was quantified by real-time polymerase chain reaction. The role of RANTES and SDF-1 in the therapeutic effect of exogenous BMSCs was examined by both in vitro and in vivo studies. The OA cartilage of the TMJ displays a synchronous increase in SDF-1 and RANTES expression and a higher capability of attracting the migration of GFP-BMSCs. The implanted GFP-BMSCs differentiated into type II collagen-positive cells and reversed cartilage degradation and subchondral bone loss in mice with OA of the TMJ. The migration of GFP-BMSCs towards OA cartilage and the rescuing effect of GFP-BMSC injections were impaired by the inhibitors of C-X-C chemokine receptor type 4 (CXCR4) and C-C chemokine receptor type 1 (CCR1), which are the receptors of SDF-1 and RANTES, respectively. Our data indicated that SDF-1/CXCR4 and RANTES/CCR1 signals are pivotal and function synergistically in the recruitment of GFP-BMSCs towards degraded cartilage in mice OA of the TMJ.

Quantitative assessment of the effects of the EPHX1 Tyr113His polymorphism on lung and breast cancer

The association between the microsomal epoxide hydrolase 1 gene (EPHX1) Tyr113His polymorphism and lung cancer and breast cancer risk has been reported in many recent studies, but there is no consensus among the results. Thus, we examined the association between the EPHX1 Tyr113His polymorphism and lung cancer through a meta-analysis. A comprehensive literature search was performed using the Pubmed and Embase databases. Odds ratios with 95% confidence intervals were used to assess the strength of associations. Our meta-analysis suggested that the Tyr113His polymorphism was associated with lung cancer risk in Asians under 3 genetic models, including a C vs T, CC vs TT, and recessive model. However, the risk was decreased in Caucasians under the genetic models, including a C vs T, CC vs TT, or CT vs TT, dominant, and recessive model. In contrast, there was no association with breast cancer risk for any of the genetic models. Our meta-analysis suggested that the EPHX1 Tyr113His polymorphism may be a risk factor for lung cancer in Asians, whereas it may be a decreased risk factor among Caucasians. However, this polymorphism was not found to be associated with breast cancer.

Overexpressed TGF-β in subchondral bone leads to mandibular condyle degradation

Emerging evidence has implied that subchondral bone plays an important role during osteoarthritis (OA) pathology. This study was undertaken to investigate whether abnormalities of the condylar subchondral bone lead to temporomandibular joint (TMJ) OA. We used an osteoblast-specific mutant TGF-β1 transgenic mouse, the CED mouse, in which high levels of active TGF-β1 occur in bone marrow, leading to abnormal bone remodeling. Subchondral bone changes in the mandibular condyles were investigated by micro-CT, and alterations in TMJ condyles were confirmed by histopathological and immunohistochemical analysis. Abnormalities in the condylar subchondral bone, characterized as fluctuant bone mineral density and microstructure and increased but uncoupled activity of osteoclasts and osteoblasts, were apparent in the 1- and 4-month CED mouse groups, while obvious cartilage degradation, in the form of cell-free regions and proteoglycan loss, was observed in the 4-month CED group. In addition, increased numbers of apoptotic chondrocytes and MMP9- and VEGF-positive chondrocytes were observed in the condylar cartilage in the 4-month CED group, but not in the 1-month CED group, compared with their respective age-matched controls. This study demonstrated that progressive degradation of mandibular condylar cartilage could be induced by the abnormal remodeling of the underlying subchondral bone during TMJOA progression.

Electrolytic partitioning of uranium and plutonium based on a new type of electrolytic mixer-settler

The design of a new type of electroreduction mixer-settler for the partitioning of uranium and plutonium during the Purex process, which is featured with E-shaped cathodes and U-shaped anodes in settling chamber, is described and the operational results achieved using this equipment are presented. The results show that this new type of mixer-settler has excellent separation performances. The flow rate of organic feed solution is 3 mL/min and the flow ratio of feed solution (1BF) to aqueous back extraction stream (1BX) and to organic wash stream (1BS) is 4/1/1. For an organic feed of 84 g/L uranium and 1.40 ⁓ 2.64 g/L plutonium, both the separation factor of plutonium from uranium and that of uranium from plutonium are apparently higher than 104

Isolation and partial characterization of novel genes encoding acidic cellulases from metagenomes of buffalo rumens

AIMS

To clone and characterize genes encoding novel cellulases from metagenomes of buffalo rumens.

METHODS AND RESULTS

A ruminal metagenomic library was constructed and functionally screened for cellulase activities and 61 independent clones expressing cellulase activities were isolated. Subcloning and sequencing of 13 positive clones expressing endoglucanase and MUCase activities identified 14 cellulase genes. Two clones carried two gene clusters that may be involved in the degradation of polysaccharide nutrients. Thirteen recombinant cellulases were partially characterized. They showed diverse optimal pH from 4 to 7. Seven cellulases were most active under acidic conditions with optimal pH of 5.5 or lower. Furthermore, one novel cellulase gene, C67-1, was overexpressed in Escherichia coli, and the purified recombinant enzyme showed optimal activity at pH 4.5 and stability in a broad pH range from pH 3.5 to 10.5. Its enzyme activity was stimulated by dl-dithiothreitol.

CONCLUSIONS

The cellulases cloned in this work may play important roles in the degradation of celluloses in the variable and low pH environment in buffalo rumen.

SIGNIFICANCE AND IMPACT OF THE STUDY

This study provided evidence for the diversity and function of cellulases in the rumen. The cloned cellulases may at one point of time offer potential industrial applications.

[Rapid detection of anti-HAV IgM by solid-phase immunosorbent hemagglutination inhibition test]

A solid-phase immunosorbent hemagglutination inhibition test (SPISHAI) was developed for hepatitis A virus-specific immunoglobulin M (IgM) antibody. Three hundred thirty and six sera were comparatively detected with both SPISHAI and ELISA. Among them 97 sera were positive and 237 were negative with both method. The crude agreement rate was 99.4%. With SPISHAI the titers of anti-HAV IgM ranged from 1:20 to 1:327,680 among tested sera from infected individuals by HAV. The specificity of SPISHAI was confirmed by 2-ME treatment method and blocking test. The patients with non-A hepatitis all got negative results. The SPISHAI does not require conjugated antibody and sophisticated equipment, and is not interfered with rheumatoid factor in sera. Furthermore, the result of the test can be got within 3 hours. Therefore, the SPISHAI is a cheap and simple, and could be applied for early diagnosis and epidemiological surveillance of hepatitis A in the community and in primary health care.

[Observation of the outcome of 112 cases with Graves' disease treated by short-term antithyroid drug therapy for one year]

One hundred and twelve new cases with Graves' disease were treated by tapazole for 6 months and followed-up for another 12 months in a prospective study. One hundred and eleven cases completed the whole course of study, and only one failed to be followed up. The results of the follow-up for 12 mon showed that the remission rate was 41.4% (46/111) and relapse rate was 58.6% (65/111). The present study indicated that the remission or relapse was related with serum levels of T3 before treatment, shrank goiter and disappearance of goiter bruit during the treatment as well as thyroid suppression rate, but not related to sex, age, period of illness before therapy or severity of the disease. It is suggested that a 6-mon antithyroid drug therapy instead of traditional long term therapy may be suitable for those patients who are with a reduced goiter and disappeared goiter bruit during the antithyroid therapy, and suppressible thyroid up-take by T3 and whose serum levels of T3 before treatment are not very high. So the patients may benefit from the short-term therapy. They are not only able to obtain a prolonged remission but also save time and money.