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INTRODUCTION: This study aims to explore Programmed Death Receptor-1 (PD-1) and Programmed Death Ligand-1 (PD-L1) variations in Lung Cancer (LC) tissues and Peripheral Blood (PPB) and their association with immunotherapy efficacy and prognosis. METHOD: 72 patients with LC were included in the LC group and 39 patients with concurrent benign lung disease were included in the benign group. PD-1/PDL-1 was compared in PPB and lung tissue. All LC patients were treated with immunotherapy. The relationship between PD-1/PDL-1 in LC tissue and PPB and immunotherapy efficacy was analyzed. Patients were divided into death and survival groups, and PD-1/PDL-1 in tumor tissues and PPB were compared. RESULTS: The authors found that PD-1 and PDL-1 positive expression in lung tissue and PPB in LC patients was elevated. Combined detection of PD-1 and PDL-1 was effective in diagnosing LC and evaluating the prognosis of LC patients. PD-1 and PDL-1 positive expression was reduced after disease remission while elevated in dead patients. The 3-year survival rate of patients with PD-1 positive expression was 45.45 % (25/55), which was lower (82.35 %, 14/17) than those with PD-1 negative expression. The 3-year survival rate of patients with positive and negative expression of PDL-1 was 48.78 % (20/41) and 61.29 % (19/31), respectively. DISCUSSION: The present results demonstrated that PD-1 and PDL-1 are abnormal in cancer tissue and PPB of LC patients. The combined detection of PD-1 and PDL-1 has diagnostic value for LC and evaluation value for the efficacy and prognosis of immunotherapy.
Subject(s)
B7-H1 Antigen , Immunotherapy , Lung Neoplasms , Programmed Cell Death 1 Receptor , Humans , Lung Neoplasms/therapy , Lung Neoplasms/mortality , Male , Female , Middle Aged , Programmed Cell Death 1 Receptor/analysis , Prognosis , Immunotherapy/methods , B7-H1 Antigen/analysis , Aged , Treatment Outcome , Adult , Biomarkers, Tumor/analysis , ImmunohistochemistryABSTRACT
Atomic layer deposition (ALD) offers unique capabilities to fabricate atomically engineered porous materials with precise pore tuning and multi-functionalization for diverse applications like advanced membrane separations towards sustainable energy-water systems. However, current ALD technique is inhibited on most non-polar polymeric membranes due to lack of accessible nucleation sites. Here, we report a facile method to efficiently promote ALD coating on hydrophobic surface of polymeric membranes via novel protein activation/sensitization. As a proof of concept, TiO2 ALD-coated membranes activated by bovine serum albumin exhibit remarkable superhydrophilicity, ultralow underwater crude oil adhesion, and robust tolerance to rigorous environments including acid, alkali, saline, and ethanol. Most importantly, excellent cyclable crude oil-in-water emulsion separation performance can be achieved. The mechanism for activation/sensitization is rooted in reactivity for a particular set of amino acids. Furthermore, the universality of protein-sensitized ALD is demonstrated using common egg white, promising numerous potential usages in biomedical engineering, environmental remediation, low-carbon manufacturing, catalysis, and beyond.
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Abstract Introduction This study aims to explore Programmed Death Receptor-1 (PD-1) and Programmed Death Ligand-1 (PD-L1) variations in Lung Cancer (LC) tissues and Peripheral Blood (PPB) and their association with immunotherapy efficacy and prognosis. Method 72 patients with LC were included in the LC group and 39 patients with concurrent benign lung disease were included in the benign group. PD-1/PDL-1 was compared in PPB and lung tissue. All LC patients were treated with immunotherapy. The relationship between PD-1/PDL-1 in LC tissue and PPB and immunotherapy efficacy was analyzed. Patients were divided into death and survival groups, and PD-1/PDL-1 in tumor tissues and PPB were compared. Results The authors found that PD-1 and PDL-1 positive expression in lung tissue and PPB in LC patients was elevated. Combined detection of PD-1 and PDL-1 was effective in diagnosing LC and evaluating the prognosis of LC patients. PD-1 and PDL-1 positive expression was reduced after disease remission while elevated in dead patients. The 3-year survival rate of patients with PD-1 positive expression was 45.45 % (25/55), which was lower (82.35 %, 14/17) than those with PD-1 negative expression. The 3-year survival rate of patients with positive and negative expression of PDL-1 was 48.78 % (20/41) and 61.29 % (19/31), respectively. Discussion The present results demonstrated that PD-1 and PDL-1 are abnormal in cancer tissue and PPB of LC patients. The combined detection of PD-1 and PDL-1 has diagnostic value for LC and evaluation value for the efficacy and prognosis of immunotherapy.
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OBJECTIVE: To investigate the effect of volatile anesthetics on the rates of postoperative myocardial infarction (MI) and cardiac death after coronary artery bypass graft (CABG). DESIGN: A post hoc analysis of a randomized trial. SETTING: Cardiac surgical operating rooms. PARTICIPANTS: Patients undergoing elective, isolated CABG. INTERVENTIONS: Patients were randomized to receive a volatile anesthetic (desflurane, isoflurane, or sevoflurane) or total intravenous anesthesia (TIVA). The primary outcome was hemodynamically relevant MI (MI requiring high-dose inotropic support or prolonged intensive care unit stay) occurring within 48 hours from surgery. The secondary outcome was 1-year death due to cardiac causes. Measurements and main Results: A total of 5,400 patients were enrolled between April 2014 and September 2017 (2,709 patients randomized to the volatile anesthetics group and 2,691 to TIVA). The mean age was 62 ± 8.4 years, and the median baseline ejection fraction was 57% (50-67), without differences between the 2 groups. Patients in the volatile group had a lower incidence of MI with hemodynamic complications both in the per-protocol (14 of 2,530 [0.6%] v 27 of 2,501 [1.1%] in the TIVA group; p = 0.038) and as-treated analyses (16 of 2,708 [0.6%] v 29 of 2,617 [1.1%] in the TIVA group; p = 0.039), but not in the intention-to-treat analysis (17 of 2,663 [0.6%] v 28 of 2,667 [1.0%] in the TIVA group; p = 0.10). Overall, deaths due to cardiac causes were lower in the volatile group (23 of 2,685 [0.9%] v 40 of 2,668 [1.5%] than in the TIVA group; p = 0.03). CONCLUSIONS: An anesthetic regimen, including volatile agents, may be associated with a lower rate of postoperative MI with hemodynamic complication in patients undergoing CABG. Furthermore, it may reduce long-term cardiac mortality.
Subject(s)
Transplants , Desflurane , Anesthesia, Intravenous , AnestheticsABSTRACT
Venezuelan equine encephalitis virus (VEEV) is an enveloped RNA virus that causes encephalitis and potentially mortality in infected humans and equines1. At present, no vaccines or drugs are available that prevent or cure diseases caused by VEEV. Low-density lipoprotein receptor class A domain-containing 3 (LDLRAD3) was recently identified as a receptor for the entry of VEEV into host cells2. Here we present the cryo-electron microscopy structure of the LDLRAD3 extracellular domain 1 (LDLRAD3-D1) in complex with VEEV virus-like particles at a resolution of 3.0 Å. LDLRAD3-D1 has a cork-like structure and is inserted into clefts formed between adjacent VEEV E2-E1 heterodimers in the viral-surface trimer spikes through hydrophobic and polar contacts. Mutagenesis studies of LDLRAD3-D1 identified residues that are involved in the key interactions with VEEV. Of note, some of the LDLRAD3-D1 mutants showed a significantly increased binding affinity for VEEV, suggesting that LDLRAD3-D1 may serve as a potential scaffold for the development of inhibitors of VEEV entry. Our structures provide insights into alphavirus assembly and the binding of receptors to alphaviruses, which may guide the development of therapeutic countermeasures against alphaviruses.
Subject(s)
Encephalitis Virus, Venezuelan Equine/chemistry , Receptors, LDL/chemistry , Receptors, Virus/chemistry , Cryoelectron Microscopy , Humans , Models, Molecular , Protein Structure, Secondary , Virus InternalizationABSTRACT
BACKGROUND: Brazil, Russia, India, China, and South Africa (BRICS) are emerging economies making up almost half the global population. We analyzed trends in cardiovascular disease (CVD) mortality across the BRICS and associations with age, period, and birth cohort. METHODS: Mortality estimates were derived from the Global Burden of Disease Study 2017. We used age-period-cohort modeling to estimate cohort and period effects in CVD between 1992 and 2016. Period was defined as survey year, and period effects reflect population-wide exposure at a circumscribed point in time. Cohort effects are defined as differences in risks across birth cohort. Net drift (overall annual percentage change), local drift (annual percentage change in each age group), longitudinal age curves (expected longitudinal age-specific rate), and period (cohort) relative risks were calculated. RESULTS: In 2016, there were 8.4 million CVD deaths across the BRICS. Between 1992 and 2016, the reduction in CVD age-standardized mortality rate in BRICS (-17%) was less than in North America (-39%). Eighty-eight percent of the increased number of all-cause deaths resulted from the increase in CVD deaths. The age-standardized mortality rate from stroke and hypertensive heart disease declined by approximately one-third across the BRICS, whereas ischemic heart disease increased slightly (2%). Brazil had the largest age-standardized mortality rate reductions across all CVD categories, with improvement both over time and in recent birth cohorts. South Africa was the only country where the CVD age-standardized mortality rate increased. Different age-related CVD mortality was seen in those ≥50 years of age in China, ≤40 years of age in Russia, 35 to 60 years of age in India, and ≥55 years of age in South Africa. Improving period and cohort risks for CVD mortality were generally found across countries, except for worsening period effects in India and greater risks for ischemic heart disease in Chinese cohorts born in the 1950s and 1960s. CONCLUSIONS: Except for Brazil, reductions of CVD mortality across the BRICS have been less than that in North America, such that China, India, and South Africa contribute an increasing proportion of global CVD deaths. Brazil's example suggests that prevention policies can both reduce the risks for younger birth cohorts and shift the risks for all age groups over time.
Subject(s)
Age Factors , Cardiovascular Diseases/epidemiology , Global Burden of Disease/statistics & numerical data , Adult , Brazil/epidemiology , Cardiovascular Diseases/mortality , China/epidemiology , Cohort Studies , Female , Humans , India/epidemiology , Male , Middle Aged , Risk , Russia/epidemiology , South Africa/epidemiology , Survival AnalysisABSTRACT
Amphimerus Barker, 1911 is a liver fluke infecting several animal species and humans. Being a digenetic trematode of the Opisthorchiidae family, Amphimerus is closely related to the genera Metorchis, Clonorchis and Opisthorchis. Recently, a high prevalence of Amphimerus infection in humans, cats, and dogs had been demonstrated in a tropical Pacific region of Ecuador. Hence, we determined and characterized the entire mt genome sequences of adult liver flukes, morphologically identified as Amphimerus, collected in the endemic region of Ecuador, and examined its phylogenetic relationships with flukes in the Opisthorchiidae family using Bayesian inference (BI) based on the concatenated amino acid sequences and partial cox1 sequences. The complete mt genome sequence (15, 151 bp in length) of the Amphimerus sp. contains 35 genes, including 12 protein-coding genes (PCGs, without atp8), two rRNAs (rrnL and rrnS) and 21 tRNAs, lacking trnG. The gene content and arrangement of the Ecuadorian Amphimerus mt genome was similar to those of other trematodes in the Opisthorchiidae family. All genes in the circular mt genome of Amphimerus sp. are transcribed from the same strand in one direction, with the A + T content of 60.77%. Genetic distances between Amphimerus sp. and other genera in Opisthorchiidae were rather high, ranging from 26.86% to 28.75% at nucleotide level and 29.37%-31.12% at amino acid level. Phylogenetic analysis placed the Ecuadorian Amphimerus within the branch of Opisthorchiidae, but very distinct from Opisthorchis. Our results indicate that the liver fluke Amphimerus from Ecuador does not belong to the genus Opisthorchis, and that it should be assigned under the genus Amphimerus. The determination of the mt genome of the Ecuadorian Amphimerus provides a new genetic resource for future studies on taxonomy and molecular epidemiology of Opisthorchiidae trematodes.
Subject(s)
DNA, Helminth/genetics , Fasciola hepatica/genetics , Genome, Mitochondrial , Phylogeny , Animals , Bayes Theorem , Ecuador , HumansABSTRACT
BACKGROUND: Volatile (inhaled) anesthetic agents have cardioprotective effects, which might improve clinical outcomes in patients undergoing coronary-artery bypass grafting (CABG). METHODS: We conducted a pragmatic, multicenter, single-blind, controlled trial at 36 centers in 13 countries. Patients scheduled to undergo elective CABG were randomly assigned to an intraoperative anesthetic regimen that included a volatile anesthetic (desflurane, isoflurane, or sevoflurane) or to total intravenous anesthesia. The primary outcome was death from any cause at 1 year. RESULTS: A total of 5400 patients were randomly assigned: 2709 to the volatile anesthetics group and 2691 to the total intravenous anesthesia group. On-pump CABG was performed in 64% of patients, with a mean duration of cardiopulmonary bypass of 79 minutes. The two groups were similar with respect to demographic and clinical characteristics at baseline, the duration of cardiopulmonary bypass, and the number of grafts. At the time of the second interim analysis, the data and safety monitoring board advised that the trial should be stopped for futility. No significant difference between the groups with respect to deaths from any cause was seen at 1 year (2.8% in the volatile anesthetics group and 3.0% in the total intravenous anesthesia group; relative risk, 0.94; 95% confidence interval [CI], 0.69 to 1.29; P = 0.71), with data available for 5353 patients (99.1%), or at 30 days (1.4% and 1.3%, respectively; relative risk, 1.11; 95% CI, 0.70 to 1.76), with data available for 5398 patients (99.9%). There were no significant differences between the groups in any of the secondary outcomes or in the incidence of prespecified adverse events, including myocardial infarction. CONCLUSIONS: Among patients undergoing elective CABG, anesthesia with a volatile agent did not result in significantly fewer deaths at 1 year than total intravenous anesthesia. (Funded by the Italian Ministry of Health; MYRIAD ClinicalTrials.gov number, NCT02105610.). (AU)
Subject(s)
Humans , Male , Female , Middle Aged , Coronary Artery Bypass , Anesthetics, Inhalation , Anesthesia, General , Anesthesia, IntravenousABSTRACT
OBJECTIVE:A careful choice of perioperative care strategies is pivotal to improve survival in cardiac surgery. However, there is no general agreement or particular attention to which nonsurgical interventions can reduce mortality in this setting. The authors sought to address this issue with a consensus-based approach.DESIGN:A systematic review of the literature followed by a consensus-based voting process.SETTING:A web-based international consensus conference.PARTICIPANTS:More than 400 physicians from 52 countries participated in this web-based consensus conference.INTERVENTIONS:The authors identified all studies published in peer-reviewed journals that reported on interventions with a statistically significant effect on mortality in the setting of cardiac surgery through a systematic Medline/PubMed search and contacts with experts. These studies were discussed during a consensus meeting and those considered eligible for inclusion in this study were voted on by clinicians worldwide.MEASUREMENTS AND MAIN RESULTS:Eleven interventions finally were selected: 10 were shown to reduce mortality (aspirin, glycemic control, high-volume surgeons, prophylactic intra-aortic balloon pump, levosimendan, leuko-depleted red blood cells transfusion, noninvasive ventilation, tranexamic acid, vacuum-assisted closure, and volatile agents), whereas 1 (aprotinin) increased mortality. A significant difference in the percentages of agreement among different countries and a variable gap between agreement and clinical practice were found for most of the interventions.CONCLUSIONS:This updated consensus process identified 11 nonsurgical interventions with possible survival implications for patients undergoing cardiac surgery. This list of interventions may help cardiac anesthesiologists and intensivists worldwide in their daily clinical practice and can contribute to direct future research in the field.
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Perioperative Period/methods , Perioperative Period/mortalityABSTRACT
OBJECTIVE: To assess the trend of sex disparity in hemoglobin concentration and prevalence of anemia among Chinese school-aged children from 1995 to 2010. STUDY DESIGN: Data were collected from 360 866 children aged 7, 9, 12, 14, and 17 years during 4 cross-sectional surveys (1995, 2000, 2005, and 2010) of the Chinese National Surveys on Students Constitution and Health. Shifts in hemoglobin concentration distributions were compared by sex. Average shifts and sex differences were calculated with quantile regression models. Logistic regression was used to estimate the prevalence odds ratio of sex for prevalence of anemia in different surveys. RESULTS: The mean hemoglobin concentration increased among Chinese children between 1995 and 2010, from 132.7 to 138.3 g/L in boys, and from 127.7 to 132.3 g/L in girls. The prevalence of anemia decreased from 18.8% in 1995 to 9.9% in 2010. It was higher in rural than urban children among all age groups. The prevalence odds ratios of girls versus boys for anemia increased in both urban and rural areas over time. CONCLUSION: Hemoglobin concentration and prevalence of anemia improved among Chinese school-aged children over time. Hemoglobin concentration improved faster in boys than girls and as a result the relative prevalence of anemia in girls compared with boys increased. Sex-specific preventive guidelines and public health policies for childhood anemia are needed in China.
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Anemia/epidemiology , Health Status Disparities , Hemoglobins/analysis , Adolescent , Anemia/diagnosis , Child , China/epidemiology , Cross-Sectional Studies , Female , Humans , Logistic Models , Male , Prevalence , Retrospective Studies , Risk Assessment , Rural Population , Severity of Illness Index , Sex Factors , Urban PopulationABSTRACT
Objective: There is initial evidence that the use of volatile anesthetics can reduce the postoperative release of cardiac troponin I, the need for inotropic support, and the number of patients requiring prolonged hospitalization following coronary artery bypass graft (CABG) surgery. Nevertheless,small Randomized Controlled Trials have failed to demonstrate a survival advantage. Thus, whethervolatile anesthetics improve the postoperative outcome of cardiac surgical patients remains uncertain. An adequately powered randomized controlled trial appears desirable.Design: Single blinded, international, multicenter randomized controlled trial with 1:1 allocation ratio.Setting: Tertiary and University hospitals.
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Male , Female , Humans , Adult , Anesthesia , Drug-Related Side Effects and Adverse Reactions , MortalityABSTRACT
Two new sesquiterpenoid tropolone glycosides, liriosmasides A (1) and B (2), along with two known compounds, secoxyloganin and oplopanpheside C, were isolated from a methanol extract of the roots of Liriosma ovata. The structures of 1 and 2 were elucidated by spectroscopic methods including 1D and 2D NMR and by high-resolution mass spectrometry involving an ultra-high-performance liquid chromatography-quadrupole-orbital ion trap mass spectrometric (UHPLC-Q-Orbitrap MS) method. Compound 1 showed weak inhibitory activity against HIV RNase H.
Subject(s)
Glycosides/isolation & purification , Olacaceae/chemistry , Sesquiterpenes/isolation & purification , Tropolone/analogs & derivatives , Tropolone/isolation & purification , Chromatography, High Pressure Liquid/methods , Glycosides/chemistry , Glycosides/pharmacology , Molecular Structure , Nuclear Magnetic Resonance, Biomolecular , Peru , Plant Roots/chemistry , Ribonuclease H/antagonists & inhibitors , Sesquiterpenes/chemistry , Sesquiterpenes/pharmacology , Tropolone/chemistry , Tropolone/pharmacologyABSTRACT
Background The sea cucumber lysozyme belongs to the family of invertebrate lysozymes and is thought to be a key defense factor in protecting aquaculture animals against bacterial infection. Recently, evidence was found that the sea cucumber lysozyme exerts broad spectrum antimicrobial action in vitro against Gram-negative and Gram-positive bacteria, and it also has more potent antimicrobial activity independent of its enzymatic activity. To explore the antimicrobial role of this non-enzymatic lysozyme and model its structure to novel antimicrobial peptides, the peptide from the C-terminal amino acid residues 70-146 of the sea cucumber lysozyme in Stichopus japonicus (SjLys-C) was heterologously expressed in Escherichia coli Rosetta(DE3)pLysS. Results The fusion protein system led to over-expression of the soluble and highly stable product, an approximate 26 kDa recombinant SjLys-C protein (rSjLys-C). The present study showed that rSjLys-C displayed strong antimicrobial activity against the tested Gram-positive and Gram-negative bacteria. In particular, the heat-treated rSjLys-C exhibited more inhibitive activity than the native rSjLys-C. The structural analysis of SjLys-C showed that it is a typical hydrophilic peptide and contains a helix-loop-helix motif. The modeling of SjLys-C molecular structures at different temperatures revealed that the tertiary structure of SjLys-C at 100°C underwent a conformational change which is favorable for enhancing antimicrobial activity. Conclusion These results indicate that the expressed rSjLys-C is a highly soluble product and has a strong antimicrobial activity. Therefore, gaining a large quantity of biologically active rSjLys-C will be used for further biochemical and structural studies and provide a potential use in aquaculture and medicine.
Subject(s)
Animals , Peptide Fragments/metabolism , Sea Cucumbers , Recombinant Proteins , Anti-Infective Agents/pharmacology , Solubility , Temperature , Bacteria/drug effects , In Vitro Techniques , Muramidase , Blotting, Western , Stichopus , Escherichia coliABSTRACT
Two somatic embryogenesis receptor-like kinase genes (identified as AcSERK1 and AcSERK2) have previously been characterized from pineapple (Ananas comosus). In this work, we describe the characterization of a third gene (AcSERK3) in this family. AcSERK3 had all the characteristic domains and shared extensive sequence homology with other plant SERKs. AcSERK3 expression was studied by in situ hybridization and quantitative real-time PCR to analyze its function. Intense in situ hybridization signals were observed only in single competent cells and competent cell clusters; no hybridization signal was detected in the subsequent stages of somatic embryogenesis. AcSERK3 was highly expressed in embryogenic callus compared to other organs, e.g., 20-80 fold more than in anther but similar to that of non-embryogenic callus, which was 20-50 fold that of anther. AcSERK3 expression in root was 80 fold higher than in anther and the highest amongst all organs tested. These results indicate that AcSERK3 plays an important role in callus proliferation and root development. His-tagged AcSERK3 protein was successfully expressed and the luminescence of His6-AcSERK3 protein was only â¼5% of that of inactivated AcSERK3 protein and reaction buffer without protein, and 11.3% of that of an extract of host Escherichia coli pET-30a. This finding confirmed that the AcSERK3 fusion protein had autophosphorylation activity.
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OBJECTIVES: To estimate the shifts in age at menarche from 1985 to 2010, compare the differences of average age at menarche between urban and rural groups, and determine the association of menarche with body mass index (BMI). STUDY DESIGN: The data were obtained from 4 cross-sectional Chinese National Surveys on Students' Constitution and Health (1985, 1995, 2005, and 2010). In this representative sample of Chinese school-aged girls, the average age at menarche was determined using probit analysis and compared between urban and rural areas. Logistic regression was used to assess the association of BMI with the likelihood of having reached menarche. RESULTS: The age at menarche in Chinese girls dropped from 13.41 years to 12.47 years from 1985 to 2010. There was a significant difference in age at menarche between urban and rural girls over time, with urban girls having their menarche earlier than rural girls. Logistic regression showed that a higher BMI was strongly associated with an increased likelihood of having reached menarche, even after controlling for age, urban or rural residence, province, social economic status, and school. CONCLUSION: The analysis suggests a drop of about 4.5 months per decade in the average age at menarche over the past 25 years, and a significant inverse association between BMI and having reached menarche. Considering that both early menarche and higher BMI are significant risk factors for chronic diseases, and may act together in later years to the detriment of a woman's health, greater attention should be paid to the health of girls with earlier menarche and higher BMI.
Subject(s)
Asian People , Menarche/physiology , Adolescent , Body Mass Index , Child , China , Female , Humans , Logistic Models , Reference Values , Social ClassABSTRACT
To evaluate the molecular mechanism of fluoroquinolones resistance in Mycoplasma hominis (MH) clinical strains isolated from urogenital specimens. 15 MH clinical isolates with different phenotypes of resistance to fluoroquinolones antibiotics were screened for mutations in the quinolone resistance-determining regions (QRDRs) of DNA gyrase (gyrA and gyrB) and topoisomerase IV (parC and parE) in comparison with the reference strain PG21, which is susceptible to fluoroquinolones antibiotics. 15 MH isolates with three kinds of quinolone resistance phenotypes were obtained. Thirteen out of these quinolone-resistant isolates were found to carry nucleotide substitutions in either gyrA or parC. There were no alterations in gyrB and no mutations were found in the isolates with a phenotype of resistance to Ofloxacin (OFX), intermediate resistant to Levofloxacin (LVX) and Sparfloxacin (SFX), and those susceptible to all three tested antibiotics. The molecular mechanism of fluoroquinolone resistance in clinical isolates of MH was reported in this study. The single amino acid mutation in ParC of MH may relate to the resistance to OFX and LVX and the high-level resistance to fluoroquinolones for MH is likely associated with mutations in both DNA gyrase and the ParC subunit of topoisomerase IV.
Subject(s)
Anti-Bacterial Agents/pharmacology , Drug Resistance, Bacterial , Fluoroquinolones/pharmacology , Mutation, Missense , Mycoplasma Infections/microbiology , Mycoplasma hominis/drug effects , Reproductive Tract Infections/microbiology , DNA Gyrase/genetics , DNA Topoisomerase IV/genetics , Humans , Mycoplasma hominis/genetics , Mycoplasma hominis/isolation & purificationABSTRACT
Aptamers that recognize the IgG Fc region are of great interest because of their wide application as an immunology probing tool, for diagnostics, and as affinity agents for antibody purification. We developed a target replacement strategy as a modification of conventional Systematic Evolution of Ligands by EXponential enrichment (SELEX) in order to efficiently select and identify novel DNA aptamers against the Fc region of mouse IgG. In this new approach, multiple IgG subclasses (IgG1, IgG2a, mouse IgG Fc, and anti-HBs IgG) were sequentially used to select aptamers in one continuous SELEX. After 8 rounds of selection, the aptamers were analyzed using dot blot and an electrophoretic mobility shift assay, which showed universal binding capability to different IgG subclasses. Secondary structure analysis of the aptamers indicated that the stem-loop structure of the aptamers play an important role in binding to the common site in different mouse IgG subclasses. This demonstrated the feasibility of using multiple target replacement SELEX for the selection of aptamers. This target replacement strategy is also expected to be useful for selecting aptamers that bind common regions of molecules other than antibodies.