Characterization of cancer stem-like cells in a novel STI571-resistant chronic myeloid leukemia cell line

Objective： To characterize a novel chronic myeloid leukemia （CML） cell line and to further elucidate the mechanisms of resistance to STI571. Methods： A novel K562 cell line （K562NP16） was achieved after exposure of the K562 cells to VP16. A small subpopulation （K562NP16 SP） that was capable of excluding Hoechst 33342 in the K562NP16 cell line was isolated by fiow cytometry sorting. The rest of the K562NP16 cells were classified as non-SP K562NP16. The mechanisms involved in K562NP16 SP cells which became resistant to STI571 were studied. Results： The levels of Bcr-Abl and Abl proteins were similar in the K562 cell line and in non-SP K562NP16 and K562NP16 SP cells. The multidrug-resistant gene 1 （MDR1） expression of the 170 kDa P-glycoprotein （P-gp） was detected in K562NP16 non-SP and K562NP16 SP cells but not in K562 cells. The expression levels of P-gp in the two K562NP16 cell lines were similar. Compared with non-SP K562/ VP16, the K562NP16 SP cells were more resistant to STI571. This resistance could hardly be reversed by many multidrug resistance inhibitors. In addition, in vivo study showed that the K562NP16 SP cells induced tumorigenesis in mice, while the K562NP16 non-SP cells failed to do so. Conclusion： A novel K562 cell line, K562NP16, was generated. A small side population K562NP16 SP cells, had high resistance to STI571 treatment and more tumorigenic than the K562 cells. It may represent the cancer stem cells of the K562NP16 cell line.

Chemoprophylaxis, diagnosis, treatments, and discharge management of COVID-19: An evidence-based clinical practice guideline(updated version)

The novel severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)is the cause of a rapidly spreading illness,coronavirus disease 2019(COVID-19),affecting more than seventeen million people around the world.Diagnosis and treatment guidelines for clinicians caring for patients are needed.In the early stage,we have issued"A rapid advice guideline for the diagnosis and treatment of 2019 novel coronavirus(2019-nCoV)infected pneumonia(standard version)";now there are many direct evidences emerged and may change some of previous recommendations and it is ripe for develop an evidence-based guideline.We formed a working group of clinical experts and methodologists.The steering group members proposed 29 questions that are relevant to the management of COVID-19 covering the following areas:chemoprophylaxis,diagnosis,treatments,and discharge management.We searched the literature for direct evidence on the management of COVID-19,and assessed its certainty generated recommendations using the Grading of Recommendations,Assessment,Development and Evaluation(GRADE)approach.Recommendations were either strong or weak,or in the form of ungraded consensus-based statement.Finally,we issued 34 statements.Among them,6 were strong recommendations for,14 were weak recommendations for,3 were weak recommendations against and 11 were ungraded consensus-based statement.They covered topics of chemoprophylaxis(including agents and Traditional Chinese Medicine(TCM)agents),diagnosis(including clinical manifestations,reverse transcription-polymerase chain reaction(RT-PCR),respiratory tract specimens,IgM and IgG antibody tests,chest computed tomography,chest X-ray,and CT features of asymptomatic infections),treatments(including lopinavirritonavir,umifenovir,favipiravir,interferon,remdesivir,combination of antiviral drugs,hydroxychloroquine/chloroquine,interleukin-6 inhibitors,interleukin-1 inhibitors,glucocorticoid,qingfei paidu decoction,lianhua qingwen granules/capsules,convalescent plasma,lung transplantation,invasive or noninvasive ventilation,and extracorporeal membrane oxygenation(ECMO)),and discharge management(including discharge criteria and management plan in patients whose RT-PCR retesting shows SARS-CoV-2 positive after discharge).We also created two figures of these recommendations for the implementation purpose.We hope these recommendations can help support healthcare workers caring for COVID-19 patients.

Prevalence and risk factors of cardiovascular diseases and psychological distress among female scientists and technicians

This study aimed to explore the prevalence and risk factors of cardiovascular disease(CVD)and psychological distress among female scientists and technicians in China.Accordingly,we included scientists and technicians from representative research institutions,medical institutions,colleges,universities,and businesses in China,and the data were collected from July 1,2019 to March 31,2021 via online questionnaires.The parameters evaluated in this study included age,sex,marital status,educational background,monthly income,sleep hours,sleep problems,smoking,alcohol consumption,work-related stress,work burnout,cardiovascular symptoms,CVD,family history,and depressive and anxiety symptoms.A total of 14530 scientists and technicians were included,comprising 7144 men and 7386 women.We found 34.9%men and 16.6%women with CVD,35.1%men and 21.4%women with depressive symptoms,28.7%men and 13.8%women with anxiety symptoms,and 22.0%men and9.5%women with CVD combined with depressive or anxiety symptoms.This study focused on the details of women.Younger women(age≤35 years)had the highest prevalence of depressive symptoms(24.9%),anxiety symptoms(16.2%),and comorbidity(11.2%).It was established that,despite traditional risk factors,unmanageable work burnout,depressive symptoms,and anxiety symptoms were associated with a higher risk of CVD in women;insomnia,overwhelming work stress,unmanageable work burnout,and CVD were linked to a higher risk of depressive symptoms and anxiety;insomnia,overwhelming work stress,and unmanageable work burnout were related to CVD combined with depressive or anxiety symptoms.A bidirectional relationship was noted between CVD and depression or anxiety in female scientists and technicians,and insomnia and overwhelming work stress were positively associated with comorbidity.It is suggested that effective measures should be taken to protect female scientists and technicians from CVD and psychological distress.

Secondary structural analysis of the mRNA regions encoding the hemagglutinin cleavage site basic amino acids of the avian influenza virus H5N1 subtype samples

Here we report the codon bias and the mRNA secondary structural features of the hemagglutinin(HA)cleavage site basic amino acid regions of avian influenza virus H5N1 subtypes.We have developed a dynamic extended folding strategy to predict RNA secondary structure with RNAstructure 4.1 program in an iterative extension process.Statistical analysis of the sequences showed that the HA cleavage site basic amino acids favor the adenine-rich codons,and the corresponding mRNA fragments are mainly in the folding states of single-stranded loops.Our sequential and structural analyses showed that to prevent and control these highly pathogenic viruses,that is,to inhibit the gene expression of avian influenza virus H5N1 subtypes,we should consider the single-stranded loop regions of the HA cleavage site-coding sequences as the targets of RNA interference.