Objective: To investigate the characteristics of katG and inhA gene mutations in multidrug-resistant tuberculosis (MDR-TB), pre-extensively drug-resistant tuberculosis (preXDR-TB), and their correlation with resistanc...Objective: To investigate the characteristics of katG and inhA gene mutations in multidrug-resistant tuberculosis (MDR-TB), pre-extensively drug-resistant tuberculosis (preXDR-TB), and their correlation with resistance to protionamide (Pto). Methods: A total of 229 patients with MDR-TB and pre-XDR-TB diagnosed in the Eighth Affiliated Hospital of Xinjiang Medical University from January 2020 to February 2024 were selected to analyze the characteristics of katG and inhA mutations in MTB clinical isolates and their correlation with Pto resistance. Results: The mutation rate of katG (with or without inhA mutation) was 85.2%. The mutation rates in MDR-TB and pre-XDR-TB were 87.4% (125/143) and 81.4% (70/86), respectively. The mutation rate of inhA (including katG mutation) was 14.8% (34/229), which was 12.6% (18/143) and 18.6% (16/86) in MDR-TB and pre-XDR-MTB, respectively. There was no difference in mutation (P > 0.05). Conclusion: The total resistance rate to Pto in 229 strains was 8.7% (20/229), which was 8.4% (12/143) and 9.3% (8/86) in MDR-TB and pre-XDR-TB, respectively. Among the inhA mutant strains, 13 were resistant to the Pto phenotype, and the resistance rate was 65% (13/20). In MDR-TB and pre-XDR-TB strains resistant to Pto, inhA gene mutations occurred in 66.7% (6/9) and 63.6% (7/11), respectively. The resistance rates of MDR-MTB and pre-XDR-TB strains without inhA gene mutation to Pto were 2.4% (3/125) and 5.7% (4/70), respectively.展开更多
Genome sequencing has revealed frequent mutations in Ras homolog family member A(RHOA)among various cancers with unique aberrant profiles and pathogenic effects,especially in peripheral T-cell lymphoma(PTCL).The discr...Genome sequencing has revealed frequent mutations in Ras homolog family member A(RHOA)among various cancers with unique aberrant profiles and pathogenic effects,especially in peripheral T-cell lymphoma(PTCL).The discrete positional distribution and types of RHOA amino acid substitutions vary according to the tumor type,thereby leading to different functional and biological properties,which provide new insight into the molecular pathogenesis and potential targeted therapies for various tumors.However,the similarities and discrepancies in characteristics of RHOA mutations among various histologic subtypes of PTCL have not been fully elucidated.Herein we highlight the inconsistencies and complexities of the type and location of RHOA mutations and demonstrate the contribution of RHOA variants to the pathogenesis of PTCL by combining epigenetic abnormalities and activating multiple downstream pathways.The promising potential of targeting RHOA as a therapeutic modality is also outlined.This review provides new insight in the field of personalized medicine to improve the clinical outcomes for patients.展开更多
Introduction: Despite the success derived from antiretroviral therapy, drug resistance (DR) mutations are known to develop and are major impediments to treatment of HIV patients. Therefore, periodic assessment of HIVD...Introduction: Despite the success derived from antiretroviral therapy, drug resistance (DR) mutations are known to develop and are major impediments to treatment of HIV patients. Therefore, periodic assessment of HIVDR is needed to ensure continuous HAART efficacy. This study assessed the magnitude of drug resistance as well as HIV genetic variability in drug-naive and treated patients in Nigeria. Methodology: Genotypic analysis was performed by sequencing plasma specimens from 40 individuals in a cross sectional study involving 202 HIV infected patients from all the six geopolitical zones of Nigeria. Sequences were analyzed for presence of HIVDR mutation using the algorithm in Stanford HIVDR database and confirmed by IAS-USA 2009 mutation list. Phylogenetic and recombination analyses were done using PAUP V4.0 and REGA V2.0 respectively. Results: Major DR mutations were detected in the reverse transcriptase (RT) gene of 5 (33%) drug experienced and 2 (8%) na?ve patients. Most common mutations were M184V and K103N with no protease (PR) mutations detected. Thymidine analogue mutations (TAMs) and a complex multi resistance mutation Q151M were detected in 3 samples. Polymorphic substitutions were observed in both PR and RT gene. Phylogenetic analysis revealed Group M isolates of G (20), J (1), circulating recombinant forms: CRF02_AG (14), CRF-18-cpx (1), CRF06_cpx (3) and a unique AD recombinant (1). Conclusion: Our findings corroborate previous studies on circulating DR viruses in Nigeria while genetic diversity is on the increase. In view of ART scale-up, monitoring the resistance pattern and genetic diversity will aid in appropriate prevention strategies.展开更多
Objective To investigate distinctive features in drug-resistant mutations (DRMs) and interpretations for reverse transcriptase inhibitors (RTIs) between proviral DNA and paired viral RNA in HIV-l-infected patients...Objective To investigate distinctive features in drug-resistant mutations (DRMs) and interpretations for reverse transcriptase inhibitors (RTIs) between proviral DNA and paired viral RNA in HIV-l-infected patients. Methods Forty-three HIV-l-infected individuals receiving first-line antiretroviral therapy were recruited to participate in a multicenter AIDS Cohort Study in Anhui and Henan Provinces in China in 2004. Drug resistance genotyping was performed by bulk sequencing and deep sequencing on the plasma and whole blood of 77 samples, respectively. Drug-resistance interpretation was compared between viral RNA and paired proviral DNA. Results Compared with bulk sequencing, deep sequencing could detect more DRMs and samples with DRMs in both viral RNA and proviral DNA. The mutations M1841 and M2301 were more prevalent in proviral DNA than in viral RNA (Fisher's exact test, P〈0.05). Considering 'majority resistant variants', 15 samples (19.48%) showed differences in drug resistance interpretation between viral RNA and proviral DNA, and 5 of these samples with different DRMs between proviral DNA and paired viral RNA showed a higher level of drug resistance to the first-line drugs. Considering 'minority resistant variants', 22 samples (28.57%) were associated with a higher level of drug resistance to the tested RTIs for proviral DNA when compared with paired viral RNA. Conclusion Compared with viral RNA, the distinctive information of DRMs and drug resistance interpretations for proviral DNA could be obtained by deep sequencing, which could provide more detailed and precise information for drug resistance monitoring and the rational design of optimal antiretroviral therapy regimens.展开更多
Objective:To analyze the mutation characteristics of inhA and katG genes in isoniazid-resistant Mycobacterium tuberculosis in Xinjiang.Methods:The katG and inhA in 148 strains of isoniazid-resistant Mycobacterium tube...Objective:To analyze the mutation characteristics of inhA and katG genes in isoniazid-resistant Mycobacterium tuberculosis in Xinjiang.Methods:The katG and inhA in 148 strains of isoniazid-resistant Mycobacterium tuberculosis were amplified through fluorescence quantitative PCR,and the amplified products were sequenced and compared.Results:The inhA gene mutation rate of 148 strains of isoniazid-resistant mycobacterium tuberculosis was 13.51%(20/148),among which the inhA gene mutation rate among patients of Han,Uygur,and Kazakh ethnicity were 15.87%,13.21%,and 17.65%,respectively.There was no significant difference in the inhA mutation rate among nationalities(c^(2)=2.897,P>0.05).The mutation rate of the katG gene was 84.46%(125/148),among which the mutation rates of patients of Han,Uyghur,and Kazak ethnicities were 82.54%,84.91%,and 76.47%,respectively.The Hui and other ethnic groups were all affected by the katG gene mutation.There was no significant difference in the mutation rate of the katG gene among different ethnicities(c^(2)=3.772,P>0.05).The mutation rates of the inhA gene in southern Xinjiang,northern Xinjiang,and other provinces were 18.60%,9.28%,and 37.50%,respectively.The mutation rates of the inhA gene in different regions were statistically different(c^(2)=6.381,P<0.05).There was no significant difference in the inhA mutation rate between patients from southern and northern Xinjiang(c^(2)=2.214,P>0.05)and between southern Xinjiang and other provinces(c^(2)=1.424,P>0.05).However,the mutation rate of the inhA gene in patients from other provinces was higher than that in northern Xinjiang(c^(2)=5.539,P<0.05).The mutation rates of the katG gene in southern Xinjiang,northern Xinjiang,and other provinces were 81.40%,87.63%,and 62.50%,respectively.There was no significant difference in the mutation rates of the katG gene among different regions(c^(2)=3.989,P>0.05).Conclusion:katG gene mutation was predominant in isoniazid-resistant tuberculosis patients in Xinjiang Uygur Autonomous Region,and inhA and katG gene mutation were no different among different ethnic groups.展开更多
A comparative molecular dynamics (MD) simulation study was performed on the p53 oncoprotein to investigate the effect of the Arg273His (R273H) mutation on the p53→DNA Binding Domain (DBD). The two p53 dimer structure...A comparative molecular dynamics (MD) simulation study was performed on the p53 oncoprotein to investigate the effect of the Arg273His (R273H) mutation on the p53→DNA Binding Domain (DBD). The two p53 dimer structures of the wild-type and mutant Arg273His (R273H) were simulated with the same thermodynamic and environmental parameters. The obtained results demonstrate that the induced Arg273His mutation has a considerable effect on the p53→DNA close contact interaction and changes the picture of hydrogen formation. The Arg273His mutation, in some cases, destroys the existing native hydrogen bond, but, in other cases, forms a strong p53→DNA hydrogen bond, which is not proper for the native protein. The MD simulation results illustrate some molecular mechanism of the conformational changes of the Arg273His key amino acid residue in the p53→DNA binding domain, which might be important for the understanding of the physiological functioning of the p53 protein and the origin of cancer.展开更多
BACKGROUND: The long-term use of nudeos(t)ide analogues causes drug resistance and mutations in the HBV reverse tran- scriptase (RT) region of the polymerase gene. The RT region overlaps the HBV surface gene (S ...BACKGROUND: The long-term use of nudeos(t)ide analogues causes drug resistance and mutations in the HBV reverse tran- scriptase (RT) region of the polymerase gene. The RT region overlaps the HBV surface gene (S gene) and therefore, the mutations in the RT region simultaneously modify S gene sequence. Certain mutations in the RT region bring about truncated S proteins because the corresponding changed S gene encodes a stop codon which results in the loss of a large portion of the C-terminal hydrophobic region of HBV surface protein. The rtA181T/sW172*, rtM204I/sW196* and rtV191I/sW182* are the most frequently reported drug-resistant mutations with C-terminal truncation, these mutations have oncogenic potential. DATA SOURCES: PubMed and Web of Science were searched using terms: "hepatitis B virus", "HBV drug resistance mutation" "HBV surface protein" "HBV truncation", "hepatocellular carcinoma", "rtA181T/sW172*", "rtM204I/sW196*", "rtV191I/sW182*", and relevant articles published in English in the past decades were reviewed. RESULTS: The rtA181T/sW172* and rtV191I/sW182* mutants occurred more frequently than the rtM204I/sW196* mutant both in chronic hepatitis B patients and the HBV-related hepatocellular carcinoma tissues. Although these mutations occur naturally, nudeos(t)ide analogues therapy is the main driving force. These mutations may exist alone or coexist with other HBV mutations. All these three mutants impair the virion secretion and result in HBV surface protein retention and serum HBV DNA level reduction. These mutations possess potential carcinogenic properties. The three mutations are resistant to more than one nucleos(t)ide analogue and therefore, it is difficult to treat the patients with the truncated mutations.CONCLUSIONS: Nucleos(t)ide analogues induce drug resistance and HBV S gene truncated mutations. These mutations have potential carcinogenesis.展开更多
Objective: To evaluate five drug treatment regimens in the treatment of Brucella spondylitis. Methods: Patients with clinical symptoms compatible and diagnostic test consistent with Brucella spondylitis were randomly ...Objective: To evaluate five drug treatment regimens in the treatment of Brucella spondylitis. Methods: Patients with clinical symptoms compatible and diagnostic test consistent with Brucella spondylitis were randomly assigned to five drug treatment regimens. Results: Combination therapy with doxycycline, rifampin and sulfamethoxazole for 56 consecutive days showed the highest cure rate of 20% after a single course and of 85% after a double course with affectivity rates of 55% and 95%. Cure rate and affectivity rate was significant better (P 0.05) than for patients receiving doxycycline, rifampin and streptomycin for the same period and regimens containing doxycycline were significant better than regimens without this drug. Conclusion: Combination therapy of doxycycline, rifampin and sulfamethoxazole for 8 weeks using one or two full courses should be recommended for Brucella spondylitis.展开更多
Lamivudine is an antiviral used for the treatment of chronic hepatitis B. Several studies have reported various mutations that are induced by lamivudine therapy. These mutations in the tyrosine-methionineaspartate-asp...Lamivudine is an antiviral used for the treatment of chronic hepatitis B. Several studies have reported various mutations that are induced by lamivudine therapy. These mutations in the tyrosine-methionineaspartate-aspartate(YMDD) motif are necessary and sufficient to confer high-level lamivudine resistance. During treatment with lamivudine, mutations develop in the YMDD motif of the hepatitis B virus(HBV) polymerase gene and lamivudine cannot prevent the replication of the mutant form. The virulence strain of developed mutation in the polymerase gene is lower than the original virus and they are susceptible to treatment with some other nucleoside analogs except lamivudine. Entecavir and tenofovir are potent HBV inhibitors and they can be confidently used as first line monotherapies. We read the article written by Tan et al that lamivudine therapy improved the clinical course in HBV patients with natural YMDD mutations. We think that lamivudine use for this patient group is not appropriate. These patients should use YMDD mutant form-effective drugs such as adefovir, tenofovir.展开更多
Hepatitis B virus(HBV)infection is a major cause of acute and chronic hepatitis,and of its long-term complications.It is the most variable among DNA viruses,mostly because of its unique life cycle which includes the a...Hepatitis B virus(HBV)infection is a major cause of acute and chronic hepatitis,and of its long-term complications.It is the most variable among DNA viruses,mostly because of its unique life cycle which includes the activity of error-prone enzyme,reverse transcriptase,and the very high virion production per day.In last two decades,numerous research studies have shown that the speed of disease progression,reliability of diagnostic methods and the success of antiviral therapy and immunization are all influenced by genetic variability of this virus.It was shown that mutations in specific regions of HBV genome could be responsible for unwanted clinical outcomes or evasion of detection by diagnostic tools,thus making the monitoring for these mutations a necessity in proper evaluation of patients.The success of the vaccination programs has now been challenged by the discovery of mutant viruses showing amino acid substitutions in hepatitis B surface antigen(HBsAg),which may lead to evasion of vaccine-induced immunity.However,the emergence of these mutations has not yet raised concern since it was shown that they develop slowly.Investigations of HBV genetic variability and clinical implications of specific mutations have resulted in significant advances over the past decade,particularly in regard to management of resistance to antiviral drugs.In the era of drugs with high genetic barrier for resistance,on-going monitoring for possible resistance is still essential since prolonged therapy is often necessary.Understanding the frequencies and clinical implications of viral mutations may contribute to improvement of diagnostic procedures,more proper planning of immunization programs and creating the most efficient therapeutic protocols.展开更多
In order to understand the biological effect of space environment on growth and development of rice, four pure strains of rice seeds were placed aboard a recoverable satellite system for 15 days, and 12 new lines were...In order to understand the biological effect of space environment on growth and development of rice, four pure strains of rice seeds were placed aboard a recoverable satellite system for 15 days, and 12 new lines were selected out after recovery. And their selected progenies were examined for mutations at morphological, physiological and molecular levels, and radiation doses were measured as well. It was found that the seeds received an average dose rate of 0.177 mGy/d and an integral dose of 2.656 mGy/15 days; there were 1.5± 0.5 heavy nuclear particles /cm 2 of Z/Β≥50(Z≥20) and the numbers of Z≥3 heavy nuclear particles reached 29.7±0.5 particles/cm2 in the satellite cabin; in sum weight of one thousand seeds, 5 lines increased, while 7 lines decreased; in germination power, 7 lines increased, while 5 lines decreased; in germination capacity, 3 lines increased, while 9 lines decreased; in respiration rate of seedling, 6 lines increased, while 5 lines decreased, and one line remained unchanged; in content of chlorophyll, only 1 line increased while 10 lines decreased, and one line remained unchanged. In order to understand better mutagenesis of 971-5 at molecular level, RAPD analysis was conducted with 60 random primers, of which 11.6% were able to generate polymorphic bands between mutated and control plants. It is therefore concluded from the present data that potential uses of crop improvement of rice can be highly mutagenic and can effectively induce some mutations.展开更多
Background: Stroke is a worldwide health problem, the world’s second-leading cause of death and third-leading cause of disability. Currently, the majority of stroke patients are ischemic stroke patients. It is necess...Background: Stroke is a worldwide health problem, the world’s second-leading cause of death and third-leading cause of disability. Currently, the majority of stroke patients are ischemic stroke patients. It is necessary to evaluate risk factors to prevent ischemic stroke. Data and Methods: The risk factors for stroke in the previous fiscal year were analyzed. They were divided into nonmodifiable and modifiable factors. The probit and ordered probit models were used in the study, with 59341 and 50542 observations used in the estimation of the models, respectively. Results: Among the nonmodifiable factors, age, gender and cerebrovascular disease history are important risk factors. The history of cerebrovascular diseases is considered to be an especially important factor. Among the modifiable factors, taking antihypertensive drugs and recent large weight change are negative risk factors;however, sleeping well significantly reduces the probability of ischemic stroke. Conclusion: It is very important to ensure that medical personnel know a patient’s history of cerebrovascular diseases for proper treatments. Ischemic stroke might be considered an important side effect of antihypertensive drugs. Limitations: The dataset was observatory. There are various types of antihypertension drugs, and their effects are not analyzed.展开更多
By means of mathematical modeling methods, we analyzed the relationship between the resistance to fluoroquinolones and GyrA mutation of Salmonella from animal isolates. We found that considering the influence of the r...By means of mathematical modeling methods, we analyzed the relationship between the resistance to fluoroquinolones and GyrA mutation of Salmonella from animal isolates. We found that considering the influence of the resistance to ciprofloxacin hydrochloride, enrofloxacin, ofloxacin, pefloacin mesylate and norfloxacin nicotinate of the five types of fluoroquinolones to GyrA mutation of animal Salmonella, the resistance of pefloacin mesylate had the most significant effect, while the resistance of ciprofloxacin hydrochloride and enrofloxacin were the least significant factors. Nearly half of the Salmonella supports such a rule that the MIC of norfloxacin nicotinate reaching 64 or 128 might lead to the mutation Ser83→Phe, MIC exceeding 512 might lead to the mutation Ser83→Gly; 60% of the sample supported that the MIC of enrofloxacin reaching 32 or 64 might lead to the mutation Asp87 →Asn. 80% of them agreed to the fact that the MIC of neither ciprofloxacin hydrochloride under 64 nor pefloacin mesylate below 512 might result in the gene mutation in 119 site. All Salmonella isolates supported the conclusion that the mutation Alal19→Val took place, if and only if the MIC of norfloxacin nicotinate exceeded 512.展开更多
Impaired insulin signaling in Alzheimer’s disease(AD)brains:The insulin signaling pathway is a fundamental physiological mechanism that presents in nearly all vertebrate cells.However,sometimes cells stop respondi...Impaired insulin signaling in Alzheimer’s disease(AD)brains:The insulin signaling pathway is a fundamental physiological mechanism that presents in nearly all vertebrate cells.However,sometimes cells stop responding properly to insulin stimulation.This condition is known as insulin resistance,which is a hallmark of two very common conditions,metabolic syndrome and type 2 diabetes(T2D).展开更多
AIM:To identify hepatitis B virus polymerase gene mutations during antiviral therapy using lamivudineadefovir sequential monotherapy followed by lamivudine-adefovir combination therapy.METHODS:The patient cohort inclu...AIM:To identify hepatitis B virus polymerase gene mutations during antiviral therapy using lamivudineadefovir sequential monotherapy followed by lamivudine-adefovir combination therapy.METHODS:The patient cohort included four adult chronic hepatitis B patients who had undergone sequential monotherapy,first with lamivudine(LMV) and then,after developing viral breakthrough,with adefovir(ADV) therapy.All of the patients had non-response or viral breakthrough after LMV-ADV sequential monotherapy,which resulted in the switching of their antiviral regimen to LMV-ADV combination therapy.Eleven serum samples from the four patients who showed non-response to rescue LMV-ADV combination therapy were collected sequentially at a time before the antiviral treatment and then during the LMV monotherapy,ADV monotherapy,and LMV-ADV combination therapy.For the genotypic analysis,the whole 1310-bp polymerase gene region was amplified,cloned and sequenced.RESULTS:All patients had been previously treated with 100 mg of LMV once daily for a 15-to 26-mo period.The emergence of resistance mutations to LMV,such as rtM204V/I and/or rtL180M,were found in all patients.Their antiviral regimens were switched to ADV monotherapy as the second line treatment.All patients had viral breakthrough or non-response after the LMV-ADV sequential monotherapy.ADV-resistant mutations were detected after 13 to 19 mo of LMV-ADV sequential monotherapy.The rtA181V/T mutations were predominantly identified during the ADV treatment in the LMV-resistant patients.Twenty-seven of 38 clones were combined with an amino acid change at rt181;three clones had mutations in rt236 and one clone had a combined mutation.The rtA181V/T mutations were not suppressed by the LMV-ADV combination therapy.Thirty-nine of 64 clones showed an rtA181V/T mutation and six clones showed combined mutations in rt181 and rt236.Mutations in rt204 re-emerged during the combination treatment.The rt181 and rt204 mutations did not co-exist in one clone.CONCLUSION:Add-on lamivudine therapy with adefovir for adefovir resistance may not suppress the pre-existing adefovir-resistant mutation that develops during lamivudine-adefovir sequential monotherapy.展开更多
Background:Triple-negative breast cancer(TNBC)is the most aggressive subtype and occurs in approximately 15%–20%of diagnosed breast cancers.TNBC is characterized by its highly metastatic and recurrent features,as wel...Background:Triple-negative breast cancer(TNBC)is the most aggressive subtype and occurs in approximately 15%–20%of diagnosed breast cancers.TNBC is characterized by its highly metastatic and recurrent features,as well as a lack of specific targets and targeted therapeutics.Epidermal growth factor receptor(EGFR)is highly expressed in a variety of tumors,especially in TNBC.LR004-VC-MMAE is a new EGFR-targeting antibody–drug conjugate produced by our laboratory.This study aimed to evaluate its antitumor activities against EGFR-positive TNBC and further studied its possible mechanism of antitumor action.Methods:LR004-VC-MMAE was prepared by coupling a cytotoxic payload(MMAE)to an anti-EGFR antibody(LR004)via a linker,and the drug-to-antibody ratio(DAR)was analyzed by HIC-HPLC.The gene expression of EGFR in a series of breast cancer cell lines was assessed using a publicly available microarray dataset(GSE41313)and Western blotting.MDA-MB-468 and MDA-MB-231 cells were treated with LR004-VC-MMAE(0,0.0066,0.066,0.66,6.6 nmol/L),and the inhibitory effects of LR004-VC-MMAE on cell proliferation were examined by CCK-8 and colony formation.The migration and invasion capacity of MDA-MB-468 and MDA-MB-231 cells were tested at different LR004-VCMMAE concentrations(2.5 and 5 nmol/L)with wound healing and Transwell invasion assays.Flow cytometric analysis and tumorsphere-forming assays were used to detect the killing effects of LR004-VC-MMAE on cancer stem cells(MDA-MB-468 and MDA-MB-231 cells).The mouse xenograft models were also used to evaluate the antitumor efficacy of LR004-VC-MMAE in vivo.Briefly,BALB/c nude mice were subcutaneously inoculated with MDA-MB-468 or MDAMB-231 cells.Then they were randomly divided into 4 groups(n=6 per group)and treated with PBS,naked LR004(10 mg/kg),LR004-VC-MMAE(10 mg/kg),or doxorubicin,respectively.Tumor sizes and the body weights of mice were measured every 4 d.The effects of LR004-VC-MMAE on apoptosis and cell cycle distribution were analyzed by flow cytometry.Western blotting was used to detect the effects of LR004-VC-MMAE on EGFR,ERK,MEK phosphorylation and tumor stemness marker gene expression.Results:LR004-VC-MMAE with a DAR of 4.02 were obtained.The expression of EGFR was found to be significantly higher in TNBC cells compared with non-TNBC cells(P<0.01).LR004-VC-MMAE inhibited the proliferation of EGFRpositive TNBC cells,and the ICvalues of MDA-MB-468 and MDA-MB-231 cells treated with LR004-VC-MMAE for 72 h were(0.13±0.02)nmol/L and(0.66±0.06)nmol/L,respectively,which were significantly lower than that of cells treated with MMAE[(3.20±0.60)nmol/L,P<0.01,and(6.60±0.50)nmol/L,P<0.001].LR004-VC-MMAE effectively inhibited migration and invasion of MDA-MB-468 and MDA-MB-231 cells.Moreover,LR004-VC-MMAE also killed tumor stem cells in EGFR-positive TNBC cells and impaired their tumorsphere-forming ability.In TNBC xenograft models,LR004-VC-MMAE at 10 mg/kg significantly suppressed tumor growth and achieved complete tumor regression on day 36.Surprisingly,tumor recurrence was not observed until the end of the experiment on day 52.In a mechanistic study,we found that LR004-VC-MMAE significantly induced cell apoptosis and cell cycle arrest at G/M phase in MDAMB-468[(34±5)%vs.(12±2)%,P<0.001]and MDA-MB-231[(27±4)%vs.(18±3)%,P<0.01]cells.LR004-VC-MMAE also inhibited the activation of EGFR signaling and the expression of cancer stemness marker genes such as Oct4,Sox2,KLF4 and EpCAM.Conclusions:LR004-VC-MMAE showed effective antitumor activity by inhibiting the activation of EGFR signaling and the expression of cancer stemness marker genes.It might be a promising therapeutic candidate and provides a potential therapeutic avenue for the treatment of EGFR-positive TNBC.展开更多
Objective:To determine the genetic diversity,natural selection and mutations in Plasmodium(P.)knowlesi drug resistant molecular markers Kelch 13 and dhps gene in clinical samples of Malaysia.Methods:P.knowlesi full-le...Objective:To determine the genetic diversity,natural selection and mutations in Plasmodium(P.)knowlesi drug resistant molecular markers Kelch 13 and dhps gene in clinical samples of Malaysia.Methods:P.knowlesi full-length gene sequences Kelch 13 gene(PkK13)from 40 samples and dhps gene from 30 samples originating from Malaysian Borneo were retrieved from public databases.Genetic diversity,natural selection,and phylogenetic analysis of gene sequences were analysed using DNAsp v5.10 and MEGA v5.2.Results:Seventy-two single nucleotide polymorphic sites(SNPs)across the full-length PkK13 gene(63 synonymous substitutions and 9 non-synonymous substitutions)with nucleotide diversity ofπ~0.005 was observed.Analysis of the full-length Pkdhps gene revealed 73 SNPs andπ~0.006(44 synonymous substitutions and 29 non-synonymous substitutions).A high number of haplotypes(PkK13;H=37 and Pkdhps;H=29)with haplotype diversity of Hd~0.99 were found in both genes,indicating population expansion.Nine mutant alleles were identified in PkK13 amino acid alignment of which,7(Asp3Glu,Lys50Gln,Lys53Glu,Ser123Thr,Ser127Pro,Ser149Thr and Ala169Thr)were within the Plasmodium specific domain,2(Val372Ile and Lys424Asn)were in the BTB/POZ domain and no mutation was observed within the kelch propeller domain.The 29 non-synonymous mutations in the Pkdhps gene were novel and only presented in exon 1 and 2.Conclusions:Monitoring the mutations from clinical samples collected from all states of Malaysia along with clinical efficacy studies will be necessary to determine the drug resistance in P.knowlesi.展开更多
This study was conducted to investigate the effects of extracts of 4 Tibetan veterinary drugs on bacterial diarrhea, and to guide the clinical treatment of the disease. The inhibitory effects of the extracts of the 4 ...This study was conducted to investigate the effects of extracts of 4 Tibetan veterinary drugs on bacterial diarrhea, and to guide the clinical treatment of the disease. The inhibitory effects of the extracts of the 4 Tibetan veterinary drugs, Veronica ciliate Fisch, Usnea diffracta Vain, Sophoraflavescens var. flavescens, Lamiophlomis rotata ( Benth. ) Kudo on 14 common diarrheagenic bacteria were detected by K-B diffusion method and micro-broth dilution method. Optimization was performed on prescriptions of the 4 Tibetan veterinary drugs using orthogonal design software, and a mouse bacterial diarrhea model was established with a clinical isolate, Salmonella blegdam. According to the LD50 value of the optimal prescription of the 4 Tibetan veterinary drugs, the established mouse bacterial diarrhea model was treated in 3 dose groups, i. e. , the high, middle and low dose groups (0. 060, 0. 030 and 0. 020 g/ml, respectively). The results showed that the 4 Tibetan veterinary drugs had very good inhibitory effects on most of the tested diarrheagenic bacteria, and among them, U. diffracta had better inhibitory effects on all the tested bacteria. The optimal prescription of the d Tibetan veterinary drugs (high dose, 0.06 g/ml) exhibited very good inhibitory effect on mouse diarrhea, indicating that the prescription has very good anti-diarrhea effect, which is beneficial to the clinical treatment of such disease and the development of Tibetan veterinary drugs.展开更多
In Western countries, the mutation status of the BRCA1 and BRCA2 genes is commonly determined for genetic counseling among members of families with a history of breast or ovarian cancer, especially for women of the As...In Western countries, the mutation status of the BRCA1 and BRCA2 genes is commonly determined for genetic counseling among members of families with a history of breast or ovarian cancer, especially for women of the Ashkenazi Jewish ethnicity. Recent studies in the Cancer Genome Atlas project have demonstrated that BRCA2 mutation carriers are more responsive to platinum-based chemotherapy among high-grade serous ovarian cancer patients. Thus, in Western countries, the mutation status of BRCA1 and BRCA2 is recognized to have an important value with which to assess cancer risk and therapeutic response. However, very limited studies of BRCA1 and BRCA2 mutations and their implications for counseling and therapeutic prediction have been conducted in China. Therefore, a potentially important genetic test that is technically simple has not benefited Chinese women with an increased risk of breast or ovarian cancer. This article summarizes the current progress in the study of BRCA1/2 mutation in China and recommends an increased effort in applying advances in genetic testing to the clinical management of Chinese patients with ovarian cancer.展开更多
Drug-induced liver injury encompasses a spectrum of diseases ranging from mild biochemical abnormalities to acute liver failure; example of this scenery is hepatotoxicity caused by the first-line antituberculous drugs...Drug-induced liver injury encompasses a spectrum of diseases ranging from mild biochemical abnormalities to acute liver failure; example of this scenery is hepatotoxicity caused by the first-line antituberculous drugs isoniazid, rifampin and pyrazinamide, which are basic for treatment of drug-sensible and drug-resistant tuberculosis. In the search for pharmacological alternatives to prevent liver damage, antitubercular drugs have been the subject of numerous studies and published reviews, a great majority of them carried out by Asian countries. At the same time, hepatoprotectors from plant source are now emerging as a possible alternative to counteract the toxic effects of these therapeutic agents. The present review aims to highlight the most recent studies on the subject, based information published in scientific databases such as Scopus and Pub Med.展开更多
基金Study on the Correlation Between inhA Gene Mutation of Multidrug-Resistant MTB and Resistance to Protionamide (Project number: 2022013)。
文摘Objective: To investigate the characteristics of katG and inhA gene mutations in multidrug-resistant tuberculosis (MDR-TB), pre-extensively drug-resistant tuberculosis (preXDR-TB), and their correlation with resistance to protionamide (Pto). Methods: A total of 229 patients with MDR-TB and pre-XDR-TB diagnosed in the Eighth Affiliated Hospital of Xinjiang Medical University from January 2020 to February 2024 were selected to analyze the characteristics of katG and inhA mutations in MTB clinical isolates and their correlation with Pto resistance. Results: The mutation rate of katG (with or without inhA mutation) was 85.2%. The mutation rates in MDR-TB and pre-XDR-TB were 87.4% (125/143) and 81.4% (70/86), respectively. The mutation rate of inhA (including katG mutation) was 14.8% (34/229), which was 12.6% (18/143) and 18.6% (16/86) in MDR-TB and pre-XDR-MTB, respectively. There was no difference in mutation (P > 0.05). Conclusion: The total resistance rate to Pto in 229 strains was 8.7% (20/229), which was 8.4% (12/143) and 9.3% (8/86) in MDR-TB and pre-XDR-TB, respectively. Among the inhA mutant strains, 13 were resistant to the Pto phenotype, and the resistance rate was 65% (13/20). In MDR-TB and pre-XDR-TB strains resistant to Pto, inhA gene mutations occurred in 66.7% (6/9) and 63.6% (7/11), respectively. The resistance rates of MDR-MTB and pre-XDR-TB strains without inhA gene mutation to Pto were 2.4% (3/125) and 5.7% (4/70), respectively.
基金This work was supported by the Natural Science Foundation of Guangdong Province(Grant No.2019A1515011354).
文摘Genome sequencing has revealed frequent mutations in Ras homolog family member A(RHOA)among various cancers with unique aberrant profiles and pathogenic effects,especially in peripheral T-cell lymphoma(PTCL).The discrete positional distribution and types of RHOA amino acid substitutions vary according to the tumor type,thereby leading to different functional and biological properties,which provide new insight into the molecular pathogenesis and potential targeted therapies for various tumors.However,the similarities and discrepancies in characteristics of RHOA mutations among various histologic subtypes of PTCL have not been fully elucidated.Herein we highlight the inconsistencies and complexities of the type and location of RHOA mutations and demonstrate the contribution of RHOA variants to the pathogenesis of PTCL by combining epigenetic abnormalities and activating multiple downstream pathways.The promising potential of targeting RHOA as a therapeutic modality is also outlined.This review provides new insight in the field of personalized medicine to improve the clinical outcomes for patients.
文摘Introduction: Despite the success derived from antiretroviral therapy, drug resistance (DR) mutations are known to develop and are major impediments to treatment of HIV patients. Therefore, periodic assessment of HIVDR is needed to ensure continuous HAART efficacy. This study assessed the magnitude of drug resistance as well as HIV genetic variability in drug-naive and treated patients in Nigeria. Methodology: Genotypic analysis was performed by sequencing plasma specimens from 40 individuals in a cross sectional study involving 202 HIV infected patients from all the six geopolitical zones of Nigeria. Sequences were analyzed for presence of HIVDR mutation using the algorithm in Stanford HIVDR database and confirmed by IAS-USA 2009 mutation list. Phylogenetic and recombination analyses were done using PAUP V4.0 and REGA V2.0 respectively. Results: Major DR mutations were detected in the reverse transcriptase (RT) gene of 5 (33%) drug experienced and 2 (8%) na?ve patients. Most common mutations were M184V and K103N with no protease (PR) mutations detected. Thymidine analogue mutations (TAMs) and a complex multi resistance mutation Q151M were detected in 3 samples. Polymorphic substitutions were observed in both PR and RT gene. Phylogenetic analysis revealed Group M isolates of G (20), J (1), circulating recombinant forms: CRF02_AG (14), CRF-18-cpx (1), CRF06_cpx (3) and a unique AD recombinant (1). Conclusion: Our findings corroborate previous studies on circulating DR viruses in Nigeria while genetic diversity is on the increase. In view of ART scale-up, monitoring the resistance pattern and genetic diversity will aid in appropriate prevention strategies.
基金supported by grants from the State Key Laboratory of Infectious Disease Prevention and Control(2011SKLID102)the National Nature Science Foundation of China(81172733 and 81561128006)the 12th Five-Year National Science and Technology Major Project(2013ZX10001-006)
文摘Objective To investigate distinctive features in drug-resistant mutations (DRMs) and interpretations for reverse transcriptase inhibitors (RTIs) between proviral DNA and paired viral RNA in HIV-l-infected patients. Methods Forty-three HIV-l-infected individuals receiving first-line antiretroviral therapy were recruited to participate in a multicenter AIDS Cohort Study in Anhui and Henan Provinces in China in 2004. Drug resistance genotyping was performed by bulk sequencing and deep sequencing on the plasma and whole blood of 77 samples, respectively. Drug-resistance interpretation was compared between viral RNA and paired proviral DNA. Results Compared with bulk sequencing, deep sequencing could detect more DRMs and samples with DRMs in both viral RNA and proviral DNA. The mutations M1841 and M2301 were more prevalent in proviral DNA than in viral RNA (Fisher's exact test, P〈0.05). Considering 'majority resistant variants', 15 samples (19.48%) showed differences in drug resistance interpretation between viral RNA and proviral DNA, and 5 of these samples with different DRMs between proviral DNA and paired viral RNA showed a higher level of drug resistance to the first-line drugs. Considering 'minority resistant variants', 22 samples (28.57%) were associated with a higher level of drug resistance to the tested RTIs for proviral DNA when compared with paired viral RNA. Conclusion Compared with viral RNA, the distinctive information of DRMs and drug resistance interpretations for proviral DNA could be obtained by deep sequencing, which could provide more detailed and precise information for drug resistance monitoring and the rational design of optimal antiretroviral therapy regimens.
基金Xinjiang Uygur Autonomous Region Health Youth Medical Science and Technology Talents Special Project(Project number:WJW-202116)。
文摘Objective:To analyze the mutation characteristics of inhA and katG genes in isoniazid-resistant Mycobacterium tuberculosis in Xinjiang.Methods:The katG and inhA in 148 strains of isoniazid-resistant Mycobacterium tuberculosis were amplified through fluorescence quantitative PCR,and the amplified products were sequenced and compared.Results:The inhA gene mutation rate of 148 strains of isoniazid-resistant mycobacterium tuberculosis was 13.51%(20/148),among which the inhA gene mutation rate among patients of Han,Uygur,and Kazakh ethnicity were 15.87%,13.21%,and 17.65%,respectively.There was no significant difference in the inhA mutation rate among nationalities(c^(2)=2.897,P>0.05).The mutation rate of the katG gene was 84.46%(125/148),among which the mutation rates of patients of Han,Uyghur,and Kazak ethnicities were 82.54%,84.91%,and 76.47%,respectively.The Hui and other ethnic groups were all affected by the katG gene mutation.There was no significant difference in the mutation rate of the katG gene among different ethnicities(c^(2)=3.772,P>0.05).The mutation rates of the inhA gene in southern Xinjiang,northern Xinjiang,and other provinces were 18.60%,9.28%,and 37.50%,respectively.The mutation rates of the inhA gene in different regions were statistically different(c^(2)=6.381,P<0.05).There was no significant difference in the inhA mutation rate between patients from southern and northern Xinjiang(c^(2)=2.214,P>0.05)and between southern Xinjiang and other provinces(c^(2)=1.424,P>0.05).However,the mutation rate of the inhA gene in patients from other provinces was higher than that in northern Xinjiang(c^(2)=5.539,P<0.05).The mutation rates of the katG gene in southern Xinjiang,northern Xinjiang,and other provinces were 81.40%,87.63%,and 62.50%,respectively.There was no significant difference in the mutation rates of the katG gene among different regions(c^(2)=3.989,P>0.05).Conclusion:katG gene mutation was predominant in isoniazid-resistant tuberculosis patients in Xinjiang Uygur Autonomous Region,and inhA and katG gene mutation were no different among different ethnic groups.
文摘A comparative molecular dynamics (MD) simulation study was performed on the p53 oncoprotein to investigate the effect of the Arg273His (R273H) mutation on the p53→DNA Binding Domain (DBD). The two p53 dimer structures of the wild-type and mutant Arg273His (R273H) were simulated with the same thermodynamic and environmental parameters. The obtained results demonstrate that the induced Arg273His mutation has a considerable effect on the p53→DNA close contact interaction and changes the picture of hydrogen formation. The Arg273His mutation, in some cases, destroys the existing native hydrogen bond, but, in other cases, forms a strong p53→DNA hydrogen bond, which is not proper for the native protein. The MD simulation results illustrate some molecular mechanism of the conformational changes of the Arg273His key amino acid residue in the p53→DNA binding domain, which might be important for the understanding of the physiological functioning of the p53 protein and the origin of cancer.
基金supported by a grant from the National Natural Science Foundation of China(81071363)
文摘BACKGROUND: The long-term use of nudeos(t)ide analogues causes drug resistance and mutations in the HBV reverse tran- scriptase (RT) region of the polymerase gene. The RT region overlaps the HBV surface gene (S gene) and therefore, the mutations in the RT region simultaneously modify S gene sequence. Certain mutations in the RT region bring about truncated S proteins because the corresponding changed S gene encodes a stop codon which results in the loss of a large portion of the C-terminal hydrophobic region of HBV surface protein. The rtA181T/sW172*, rtM204I/sW196* and rtV191I/sW182* are the most frequently reported drug-resistant mutations with C-terminal truncation, these mutations have oncogenic potential. DATA SOURCES: PubMed and Web of Science were searched using terms: "hepatitis B virus", "HBV drug resistance mutation" "HBV surface protein" "HBV truncation", "hepatocellular carcinoma", "rtA181T/sW172*", "rtM204I/sW196*", "rtV191I/sW182*", and relevant articles published in English in the past decades were reviewed. RESULTS: The rtA181T/sW172* and rtV191I/sW182* mutants occurred more frequently than the rtM204I/sW196* mutant both in chronic hepatitis B patients and the HBV-related hepatocellular carcinoma tissues. Although these mutations occur naturally, nudeos(t)ide analogues therapy is the main driving force. These mutations may exist alone or coexist with other HBV mutations. All these three mutants impair the virion secretion and result in HBV surface protein retention and serum HBV DNA level reduction. These mutations possess potential carcinogenic properties. The three mutations are resistant to more than one nucleos(t)ide analogue and therefore, it is difficult to treat the patients with the truncated mutations.CONCLUSIONS: Nucleos(t)ide analogues induce drug resistance and HBV S gene truncated mutations. These mutations have potential carcinogenesis.
文摘Objective: To evaluate five drug treatment regimens in the treatment of Brucella spondylitis. Methods: Patients with clinical symptoms compatible and diagnostic test consistent with Brucella spondylitis were randomly assigned to five drug treatment regimens. Results: Combination therapy with doxycycline, rifampin and sulfamethoxazole for 56 consecutive days showed the highest cure rate of 20% after a single course and of 85% after a double course with affectivity rates of 55% and 95%. Cure rate and affectivity rate was significant better (P 0.05) than for patients receiving doxycycline, rifampin and streptomycin for the same period and regimens containing doxycycline were significant better than regimens without this drug. Conclusion: Combination therapy of doxycycline, rifampin and sulfamethoxazole for 8 weeks using one or two full courses should be recommended for Brucella spondylitis.
文摘Lamivudine is an antiviral used for the treatment of chronic hepatitis B. Several studies have reported various mutations that are induced by lamivudine therapy. These mutations in the tyrosine-methionineaspartate-aspartate(YMDD) motif are necessary and sufficient to confer high-level lamivudine resistance. During treatment with lamivudine, mutations develop in the YMDD motif of the hepatitis B virus(HBV) polymerase gene and lamivudine cannot prevent the replication of the mutant form. The virulence strain of developed mutation in the polymerase gene is lower than the original virus and they are susceptible to treatment with some other nucleoside analogs except lamivudine. Entecavir and tenofovir are potent HBV inhibitors and they can be confidently used as first line monotherapies. We read the article written by Tan et al that lamivudine therapy improved the clinical course in HBV patients with natural YMDD mutations. We think that lamivudine use for this patient group is not appropriate. These patients should use YMDD mutant form-effective drugs such as adefovir, tenofovir.
基金Supported by Ministry of Education,Science and Technological Development,Republic of Serbia,Grant No.175073
文摘Hepatitis B virus(HBV)infection is a major cause of acute and chronic hepatitis,and of its long-term complications.It is the most variable among DNA viruses,mostly because of its unique life cycle which includes the activity of error-prone enzyme,reverse transcriptase,and the very high virion production per day.In last two decades,numerous research studies have shown that the speed of disease progression,reliability of diagnostic methods and the success of antiviral therapy and immunization are all influenced by genetic variability of this virus.It was shown that mutations in specific regions of HBV genome could be responsible for unwanted clinical outcomes or evasion of detection by diagnostic tools,thus making the monitoring for these mutations a necessity in proper evaluation of patients.The success of the vaccination programs has now been challenged by the discovery of mutant viruses showing amino acid substitutions in hepatitis B surface antigen(HBsAg),which may lead to evasion of vaccine-induced immunity.However,the emergence of these mutations has not yet raised concern since it was shown that they develop slowly.Investigations of HBV genetic variability and clinical implications of specific mutations have resulted in significant advances over the past decade,particularly in regard to management of resistance to antiviral drugs.In the era of drugs with high genetic barrier for resistance,on-going monitoring for possible resistance is still essential since prolonged therapy is often necessary.Understanding the frequencies and clinical implications of viral mutations may contribute to improvement of diagnostic procedures,more proper planning of immunization programs and creating the most efficient therapeutic protocols.
文摘In order to understand the biological effect of space environment on growth and development of rice, four pure strains of rice seeds were placed aboard a recoverable satellite system for 15 days, and 12 new lines were selected out after recovery. And their selected progenies were examined for mutations at morphological, physiological and molecular levels, and radiation doses were measured as well. It was found that the seeds received an average dose rate of 0.177 mGy/d and an integral dose of 2.656 mGy/15 days; there were 1.5± 0.5 heavy nuclear particles /cm 2 of Z/Β≥50(Z≥20) and the numbers of Z≥3 heavy nuclear particles reached 29.7±0.5 particles/cm2 in the satellite cabin; in sum weight of one thousand seeds, 5 lines increased, while 7 lines decreased; in germination power, 7 lines increased, while 5 lines decreased; in germination capacity, 3 lines increased, while 9 lines decreased; in respiration rate of seedling, 6 lines increased, while 5 lines decreased, and one line remained unchanged; in content of chlorophyll, only 1 line increased while 10 lines decreased, and one line remained unchanged. In order to understand better mutagenesis of 971-5 at molecular level, RAPD analysis was conducted with 60 random primers, of which 11.6% were able to generate polymorphic bands between mutated and control plants. It is therefore concluded from the present data that potential uses of crop improvement of rice can be highly mutagenic and can effectively induce some mutations.
文摘Background: Stroke is a worldwide health problem, the world’s second-leading cause of death and third-leading cause of disability. Currently, the majority of stroke patients are ischemic stroke patients. It is necessary to evaluate risk factors to prevent ischemic stroke. Data and Methods: The risk factors for stroke in the previous fiscal year were analyzed. They were divided into nonmodifiable and modifiable factors. The probit and ordered probit models were used in the study, with 59341 and 50542 observations used in the estimation of the models, respectively. Results: Among the nonmodifiable factors, age, gender and cerebrovascular disease history are important risk factors. The history of cerebrovascular diseases is considered to be an especially important factor. Among the modifiable factors, taking antihypertensive drugs and recent large weight change are negative risk factors;however, sleeping well significantly reduces the probability of ischemic stroke. Conclusion: It is very important to ensure that medical personnel know a patient’s history of cerebrovascular diseases for proper treatments. Ischemic stroke might be considered an important side effect of antihypertensive drugs. Limitations: The dataset was observatory. There are various types of antihypertension drugs, and their effects are not analyzed.
基金Supported by the National Natural Science Foundation of China (11171244)
文摘By means of mathematical modeling methods, we analyzed the relationship between the resistance to fluoroquinolones and GyrA mutation of Salmonella from animal isolates. We found that considering the influence of the resistance to ciprofloxacin hydrochloride, enrofloxacin, ofloxacin, pefloacin mesylate and norfloxacin nicotinate of the five types of fluoroquinolones to GyrA mutation of animal Salmonella, the resistance of pefloacin mesylate had the most significant effect, while the resistance of ciprofloxacin hydrochloride and enrofloxacin were the least significant factors. Nearly half of the Salmonella supports such a rule that the MIC of norfloxacin nicotinate reaching 64 or 128 might lead to the mutation Ser83→Phe, MIC exceeding 512 might lead to the mutation Ser83→Gly; 60% of the sample supported that the MIC of enrofloxacin reaching 32 or 64 might lead to the mutation Asp87 →Asn. 80% of them agreed to the fact that the MIC of neither ciprofloxacin hydrochloride under 64 nor pefloacin mesylate below 512 might result in the gene mutation in 119 site. All Salmonella isolates supported the conclusion that the mutation Alal19→Val took place, if and only if the MIC of norfloxacin nicotinate exceeded 512.
文摘Impaired insulin signaling in Alzheimer’s disease(AD)brains:The insulin signaling pathway is a fundamental physiological mechanism that presents in nearly all vertebrate cells.However,sometimes cells stop responding properly to insulin stimulation.This condition is known as insulin resistance,which is a hallmark of two very common conditions,metabolic syndrome and type 2 diabetes(T2D).
基金Supported by A grant from the South Korea Heathcare Technology R and D Project,Ministry for Health,Welfare and Family Affairs,South Korea,No.A084826
文摘AIM:To identify hepatitis B virus polymerase gene mutations during antiviral therapy using lamivudineadefovir sequential monotherapy followed by lamivudine-adefovir combination therapy.METHODS:The patient cohort included four adult chronic hepatitis B patients who had undergone sequential monotherapy,first with lamivudine(LMV) and then,after developing viral breakthrough,with adefovir(ADV) therapy.All of the patients had non-response or viral breakthrough after LMV-ADV sequential monotherapy,which resulted in the switching of their antiviral regimen to LMV-ADV combination therapy.Eleven serum samples from the four patients who showed non-response to rescue LMV-ADV combination therapy were collected sequentially at a time before the antiviral treatment and then during the LMV monotherapy,ADV monotherapy,and LMV-ADV combination therapy.For the genotypic analysis,the whole 1310-bp polymerase gene region was amplified,cloned and sequenced.RESULTS:All patients had been previously treated with 100 mg of LMV once daily for a 15-to 26-mo period.The emergence of resistance mutations to LMV,such as rtM204V/I and/or rtL180M,were found in all patients.Their antiviral regimens were switched to ADV monotherapy as the second line treatment.All patients had viral breakthrough or non-response after the LMV-ADV sequential monotherapy.ADV-resistant mutations were detected after 13 to 19 mo of LMV-ADV sequential monotherapy.The rtA181V/T mutations were predominantly identified during the ADV treatment in the LMV-resistant patients.Twenty-seven of 38 clones were combined with an amino acid change at rt181;three clones had mutations in rt236 and one clone had a combined mutation.The rtA181V/T mutations were not suppressed by the LMV-ADV combination therapy.Thirty-nine of 64 clones showed an rtA181V/T mutation and six clones showed combined mutations in rt181 and rt236.Mutations in rt204 re-emerged during the combination treatment.The rt181 and rt204 mutations did not co-exist in one clone.CONCLUSION:Add-on lamivudine therapy with adefovir for adefovir resistance may not suppress the pre-existing adefovir-resistant mutation that develops during lamivudine-adefovir sequential monotherapy.
基金supported by the CAMS Innovation Fund for Medical Sciences(CIFMS)(2021-1-I2M-026)the Beijing Natural Science Foundation(7202133)the Non-profit Central Research Institute Fund of Chinese Academy of Medical Sciences(2021-RW350-002)。
文摘Background:Triple-negative breast cancer(TNBC)is the most aggressive subtype and occurs in approximately 15%–20%of diagnosed breast cancers.TNBC is characterized by its highly metastatic and recurrent features,as well as a lack of specific targets and targeted therapeutics.Epidermal growth factor receptor(EGFR)is highly expressed in a variety of tumors,especially in TNBC.LR004-VC-MMAE is a new EGFR-targeting antibody–drug conjugate produced by our laboratory.This study aimed to evaluate its antitumor activities against EGFR-positive TNBC and further studied its possible mechanism of antitumor action.Methods:LR004-VC-MMAE was prepared by coupling a cytotoxic payload(MMAE)to an anti-EGFR antibody(LR004)via a linker,and the drug-to-antibody ratio(DAR)was analyzed by HIC-HPLC.The gene expression of EGFR in a series of breast cancer cell lines was assessed using a publicly available microarray dataset(GSE41313)and Western blotting.MDA-MB-468 and MDA-MB-231 cells were treated with LR004-VC-MMAE(0,0.0066,0.066,0.66,6.6 nmol/L),and the inhibitory effects of LR004-VC-MMAE on cell proliferation were examined by CCK-8 and colony formation.The migration and invasion capacity of MDA-MB-468 and MDA-MB-231 cells were tested at different LR004-VCMMAE concentrations(2.5 and 5 nmol/L)with wound healing and Transwell invasion assays.Flow cytometric analysis and tumorsphere-forming assays were used to detect the killing effects of LR004-VC-MMAE on cancer stem cells(MDA-MB-468 and MDA-MB-231 cells).The mouse xenograft models were also used to evaluate the antitumor efficacy of LR004-VC-MMAE in vivo.Briefly,BALB/c nude mice were subcutaneously inoculated with MDA-MB-468 or MDAMB-231 cells.Then they were randomly divided into 4 groups(n=6 per group)and treated with PBS,naked LR004(10 mg/kg),LR004-VC-MMAE(10 mg/kg),or doxorubicin,respectively.Tumor sizes and the body weights of mice were measured every 4 d.The effects of LR004-VC-MMAE on apoptosis and cell cycle distribution were analyzed by flow cytometry.Western blotting was used to detect the effects of LR004-VC-MMAE on EGFR,ERK,MEK phosphorylation and tumor stemness marker gene expression.Results:LR004-VC-MMAE with a DAR of 4.02 were obtained.The expression of EGFR was found to be significantly higher in TNBC cells compared with non-TNBC cells(P<0.01).LR004-VC-MMAE inhibited the proliferation of EGFRpositive TNBC cells,and the ICvalues of MDA-MB-468 and MDA-MB-231 cells treated with LR004-VC-MMAE for 72 h were(0.13±0.02)nmol/L and(0.66±0.06)nmol/L,respectively,which were significantly lower than that of cells treated with MMAE[(3.20±0.60)nmol/L,P<0.01,and(6.60±0.50)nmol/L,P<0.001].LR004-VC-MMAE effectively inhibited migration and invasion of MDA-MB-468 and MDA-MB-231 cells.Moreover,LR004-VC-MMAE also killed tumor stem cells in EGFR-positive TNBC cells and impaired their tumorsphere-forming ability.In TNBC xenograft models,LR004-VC-MMAE at 10 mg/kg significantly suppressed tumor growth and achieved complete tumor regression on day 36.Surprisingly,tumor recurrence was not observed until the end of the experiment on day 52.In a mechanistic study,we found that LR004-VC-MMAE significantly induced cell apoptosis and cell cycle arrest at G/M phase in MDAMB-468[(34±5)%vs.(12±2)%,P<0.001]and MDA-MB-231[(27±4)%vs.(18±3)%,P<0.01]cells.LR004-VC-MMAE also inhibited the activation of EGFR signaling and the expression of cancer stemness marker genes such as Oct4,Sox2,KLF4 and EpCAM.Conclusions:LR004-VC-MMAE showed effective antitumor activity by inhibiting the activation of EGFR signaling and the expression of cancer stemness marker genes.It might be a promising therapeutic candidate and provides a potential therapeutic avenue for the treatment of EGFR-positive TNBC.
基金supported by the institutional funding committee of Najran University,Najran,Saudi Arabia(Project code:NU/IFC/ENT/01/007).
文摘Objective:To determine the genetic diversity,natural selection and mutations in Plasmodium(P.)knowlesi drug resistant molecular markers Kelch 13 and dhps gene in clinical samples of Malaysia.Methods:P.knowlesi full-length gene sequences Kelch 13 gene(PkK13)from 40 samples and dhps gene from 30 samples originating from Malaysian Borneo were retrieved from public databases.Genetic diversity,natural selection,and phylogenetic analysis of gene sequences were analysed using DNAsp v5.10 and MEGA v5.2.Results:Seventy-two single nucleotide polymorphic sites(SNPs)across the full-length PkK13 gene(63 synonymous substitutions and 9 non-synonymous substitutions)with nucleotide diversity ofπ~0.005 was observed.Analysis of the full-length Pkdhps gene revealed 73 SNPs andπ~0.006(44 synonymous substitutions and 29 non-synonymous substitutions).A high number of haplotypes(PkK13;H=37 and Pkdhps;H=29)with haplotype diversity of Hd~0.99 were found in both genes,indicating population expansion.Nine mutant alleles were identified in PkK13 amino acid alignment of which,7(Asp3Glu,Lys50Gln,Lys53Glu,Ser123Thr,Ser127Pro,Ser149Thr and Ala169Thr)were within the Plasmodium specific domain,2(Val372Ile and Lys424Asn)were in the BTB/POZ domain and no mutation was observed within the kelch propeller domain.The 29 non-synonymous mutations in the Pkdhps gene were novel and only presented in exon 1 and 2.Conclusions:Monitoring the mutations from clinical samples collected from all states of Malaysia along with clinical efficacy studies will be necessary to determine the drug resistance in P.knowlesi.
基金Supported by the Science and Technology Training Plan Project of Sichuan Province(2016KZ0007)the Fundamental Research Funds for the Central Universitiesof Southwest University for Nationalities(2017NZYQN38)
文摘This study was conducted to investigate the effects of extracts of 4 Tibetan veterinary drugs on bacterial diarrhea, and to guide the clinical treatment of the disease. The inhibitory effects of the extracts of the 4 Tibetan veterinary drugs, Veronica ciliate Fisch, Usnea diffracta Vain, Sophoraflavescens var. flavescens, Lamiophlomis rotata ( Benth. ) Kudo on 14 common diarrheagenic bacteria were detected by K-B diffusion method and micro-broth dilution method. Optimization was performed on prescriptions of the 4 Tibetan veterinary drugs using orthogonal design software, and a mouse bacterial diarrhea model was established with a clinical isolate, Salmonella blegdam. According to the LD50 value of the optimal prescription of the 4 Tibetan veterinary drugs, the established mouse bacterial diarrhea model was treated in 3 dose groups, i. e. , the high, middle and low dose groups (0. 060, 0. 030 and 0. 020 g/ml, respectively). The results showed that the 4 Tibetan veterinary drugs had very good inhibitory effects on most of the tested diarrheagenic bacteria, and among them, U. diffracta had better inhibitory effects on all the tested bacteria. The optimal prescription of the d Tibetan veterinary drugs (high dose, 0.06 g/ml) exhibited very good inhibitory effect on mouse diarrhea, indicating that the prescription has very good anti-diarrhea effect, which is beneficial to the clinical treatment of such disease and the development of Tibetan veterinary drugs.
文摘In Western countries, the mutation status of the BRCA1 and BRCA2 genes is commonly determined for genetic counseling among members of families with a history of breast or ovarian cancer, especially for women of the Ashkenazi Jewish ethnicity. Recent studies in the Cancer Genome Atlas project have demonstrated that BRCA2 mutation carriers are more responsive to platinum-based chemotherapy among high-grade serous ovarian cancer patients. Thus, in Western countries, the mutation status of BRCA1 and BRCA2 is recognized to have an important value with which to assess cancer risk and therapeutic response. However, very limited studies of BRCA1 and BRCA2 mutations and their implications for counseling and therapeutic prediction have been conducted in China. Therefore, a potentially important genetic test that is technically simple has not benefited Chinese women with an increased risk of breast or ovarian cancer. This article summarizes the current progress in the study of BRCA1/2 mutation in China and recommends an increased effort in applying advances in genetic testing to the clinical management of Chinese patients with ovarian cancer.
基金Part of this manuscript was supported by Grant from the Instituto Mexicano del Seguro Social,projects FIS/IMSS/PROT/G15/1414
文摘Drug-induced liver injury encompasses a spectrum of diseases ranging from mild biochemical abnormalities to acute liver failure; example of this scenery is hepatotoxicity caused by the first-line antituberculous drugs isoniazid, rifampin and pyrazinamide, which are basic for treatment of drug-sensible and drug-resistant tuberculosis. In the search for pharmacological alternatives to prevent liver damage, antitubercular drugs have been the subject of numerous studies and published reviews, a great majority of them carried out by Asian countries. At the same time, hepatoprotectors from plant source are now emerging as a possible alternative to counteract the toxic effects of these therapeutic agents. The present review aims to highlight the most recent studies on the subject, based information published in scientific databases such as Scopus and Pub Med.