1. Introduction Drug-induced liver injury (DILI), defined as liver injury caused by a drug and/or its metabolites, is a common clinical adverse drug reaction1–4. This type of injury can cause acute liver failure and ...1. Introduction Drug-induced liver injury (DILI), defined as liver injury caused by a drug and/or its metabolites, is a common clinical adverse drug reaction1–4. This type of injury can cause acute liver failure and even death in severe cases5.展开更多
Listeria monocytogenes is an important foodborne pathogen responsible for listeriosis,a fatal disease.It is widely distributed in various foods and environmental sources.In this review,we focused on addressing PCR-bas...Listeria monocytogenes is an important foodborne pathogen responsible for listeriosis,a fatal disease.It is widely distributed in various foods and environmental sources.In this review,we focused on addressing PCR-based technologies,including conventional PCR,qPCR and droplet digital PCR(ddPCR).Specifically,we described(a)conventional PCR and mono-,duplex-and multiplex-qPCR methodologies;(b)development and applications of gene HlyA-,Iap-,PrfA–and SsrA-based conventional and qPCR assays as well as PCR assays targeting newly identified gene targets for specific detection of L.monocytogenes;differentiation of viable from dead L.monocytogenes by qPCR in conjugation with propidium monoazide pretreatment;PCR-based serotype identification of L.monocytogenes isolates;PCR-based detection of L.ivanovii,infecting ruminants,differentiation of L.monocytogenes from other Listeria species;and sigB-gene based PCR identification of Listeria spp;(c)applications of ddPCR in detection of L.monocytogenes;and(d)application of qPCR assays in detection and subtyping of L.monocytogenes in milk and dairy products;meats,meat products and meat-processing environment;and seafood,seafood products and processing environment.Our goal was to provide a relatively comprehensive overview of PCR-based methodologies available in detection,characterization and subtyping of various strains of L.monocytogenes in foods and environmental sources.展开更多
Listeria monocytogenes,one of the most important foodborne pathogens,can cause listeriosis,a lethal disease for humans.L.ivanovii,which is closely related to L.monocytogenes,is also widely distributed in nature and in...Listeria monocytogenes,one of the most important foodborne pathogens,can cause listeriosis,a lethal disease for humans.L.ivanovii,which is closely related to L.monocytogenes,is also widely distributed in nature and infects mainly warm-blooded ruminants,causing economic loss.Thus,there are high priority needs for methodologies for rapid,specific,cost-effective and accurate detection,characterization and subtyping of L.monocytogenes and L.ivanovii in foods and environmental sources.In this review,we(A)described L.monocytogenes and L.ivanovii,world-wide incidence of listeriosis,and prevalence of various L.monocytogenes strains in food and environmental sources;(B)comprehensively reviewed different types of traditional and newly developed methodologies,including culture-based,antigen/antibody-based,LOOP-mediated isothermal amplification,matrix-assisted laser desorption ionization-time of flight-mass spectrometry,DNA microarray,and genomic sequencing for detection and characterization of L.monocytogenes in foods and environmental sources;(C)comprehensively summarized different subtyping methodologies,including pulsed-field gel electrophoresis,multi-locus sequence typing,ribotyping,and phage-typing,and whole genomic sequencing etc.for subtyping of L.monocytogenes strains from food and environmental sources;and(D)described the applications of these methodologies in detection and subtyping of L.monocytogenes in foods and food processing facilities.展开更多
Objective: To refine the infectious doses of enteric bacterial pathogens in animal assays and vaccine clinical trials by studying the invasion kinetics of five bacterial pathogens with human intestinal cells.Methods: ...Objective: To refine the infectious doses of enteric bacterial pathogens in animal assays and vaccine clinical trials by studying the invasion kinetics of five bacterial pathogens with human intestinal cells.Methods: Utilizing in vitro cultured cell invasion assays with gentamicin-killing step,the invasive effects were analyzed in foodborne pathogens including Salmonella,Shigella, Yersinia, Escherichia coli(E. coli) O157 and opportunistic pathogens Citrobacter in human embryonic intestine 407 cells and ileocecum HCT-8 cells at multiplicities of infection(MOIs) of 0.04–4 000.00 E. coli HS served as a noninvasive control.Results: The study results showed that the bacterial invasive efficiency and the average number of internalized bacteria per host cell changed with different starting MOIs. Higher starting MOIs did not always produce more bacterial internalization. The bacterial invasion effects varied with different bacterial strains and host cell lines. E. coli O157:H7 did invade human ileocecum HCT-8 cells.Conclusions: This study shows that these bacteria possess different invasive patterns at various starting MOIs and also in different cell lines. The results could help to figure out the appropriate infectious doses of the bacteria in animal assays and in vaccine clinical trials. The bacterial invasion kinetics is also valuable in evaluating the safety and efficacy of live attenuated bacterial vaccines.展开更多
Sand production from loosely consolidated reservoirs is one of the critical issues in the oil and gas in-dustry all around the world that can cause many problems,such as erosion of surface and well equip-ment,sand acc...Sand production from loosely consolidated reservoirs is one of the critical issues in the oil and gas in-dustry all around the world that can cause many problems,such as erosion of surface and well equip-ment,sand accumulation in wells and operation facilities,buckling of casing in cased-hole wells and well productivity reduction.Sand production control methods include restrictive production rate,mechanical methods(slotted liner,wire-wrapped screen,pre-packed screen,frac-pack,gravel pack,high-rate water pack)and chemical consolidation that chemical method is considered for more effectiveness in sand production alleviation due to increasing formation strength in near wellbore region.This review provides an overview on the laboratory and filed operation investigations of chemical remedy for sand production.Some used chemical agents and more common laboratory tests for evaluating the chemical performance in sand consolidation are introduced in this paper.Furthermore,the results of field operations and in-jections of chemicals into the desired formation are also reported.These results show that the chemical sand consolidation is more effective in newly perforated wells which have no sand production experi-ence and have a production history of less than two years.Finally,it was concluded that the main challenges in applying this method are permeability and capillary force reduction around the wellbore and selective injection into the targeted formation layers.展开更多
Amphotericin B(AmB)is an amphiphilic drug commonly formulated in liposomes and administered intravenously to treat systemic fungal infections.Recent studies on the liposomal drug product have shed light on the AmB agg...Amphotericin B(AmB)is an amphiphilic drug commonly formulated in liposomes and administered intravenously to treat systemic fungal infections.Recent studies on the liposomal drug product have shed light on the AmB aggregation status in the bilayer,which heat treatment(curing)modifies.Although toxicity was found related to aggregation status-loose aggregates significantly more toxic than tight aggregates-the precise mechanism linking aggregation and toxicitywas notwell understood.This study directlymeasured drug release rate fromvarious AmB liposomal preparations made with modified curing protocols to evaluate correlations among drug aggregation state,drug release,and in vitro toxicity.UV–Vis spectroscopy of these products detected unique curing-induced changes in the UV spectral features:a∼25nm blue-shift of the main absorption peak(λ_(max))in aqueous buffer and a decrease in the OD_(346)/OD_(322) ratio upon thermal curing,reflecting tighter aggregation.In vitro release testing(IVRT)data showed,by applying and fitting first-order release kinetic models for one or two pools,that curing impacts two significant changes:a 3–5-fold drop in the overall drug release rate and a ten-fold decrease in the ratio between the loosely aggregated and the tightly aggregated,more thermodynamically stable drug pool.The kinetic data thus corroborated the trend independently deduced from the UV–Vis spectral data.The in vitro toxicity assay indicated a decreased toxicity with curing,as shown by the significantly increased concentration,causing half-maximal potassium release(TC50).The data suggest that the release of AmB requires dissociation of the tight complexes within the bilayer and that the reduced toxicity relates to this slower rate of dissociation.This study demonstrates the relationship between AmB aggregation status within the lipid bilayer and drug release(directly measured rate constants),providing a mechanistic link between aggregation status and in vitro toxicity in the liposomal formulations.展开更多
A simple efficient isocratic reversed-phase HPLC method was developed and validated for the determination of clindamycin palmitate hydrochloride (CPH) and its commercially available oral solution products. Separation ...A simple efficient isocratic reversed-phase HPLC method was developed and validated for the determination of clindamycin palmitate hydrochloride (CPH) and its commercially available oral solution products. Separation was achieved on a Phenomenex Zorbax (Luna) cyano column (150 × 4.6 mm, 5 μm) with a Phenomenex cyano guard cartridge (4 × 3.0 mm) on Agilent 1050 series HPLC system. CPH and its resolution standard lincomycin were eluted isocratically at a flow rate of 1 mL/min with a simplified mobile phase (potassium phosphate buffer (5 mM, pH 3.0)—acetonitrile—tetrahydrofuran (20:75:5, v/v/v)) and detected at 210 nm. The column was maintained at 25?C. The method was validated according to USP category I requirements. Robustness and forced degradation studies were also conducted. CPH marketed drug products were obtained from a drug distributor and assayed for potency using the validated method. Validation acceptance criteria were met in all cases. The analytical range for CPH was 15 - 500 μg/mL and the linearity was r2 > 0.999 over three days. The method was determined to be specific and robust. Both accuracy (92.0% - 103.8%) and precision (0.67% - 1.52%) were established across the analytical range for low, intermediate and high QC concentrations. Method applicability was demonstrated by analyzing two marketed products of CPH, in which results showed potency >98%. The method was determined to be an enhancement over the current USP methodology for assay as a result of increased efficiency, reduced organic solvents and the elimination of matrix modifiers. This method was successfully applied for the quality assessment of: 1) currently marketed drug products and 2) will in future assess the product quality of novel dosage forms of CPH for pediatric use.展开更多
As an abiotic stress,adverse germination temperatures cause serious disruptions in physiological and biochemical processes involved in seed germination.Using a factorial experiment,we examined the effects of different...As an abiotic stress,adverse germination temperatures cause serious disruptions in physiological and biochemical processes involved in seed germination.Using a factorial experiment,we examined the effects of different seed priming treatments on enzymatic and biochemical performances of rice seed germination under different temperatures.Each of the rice genotypes(Hashemi,Sadry-domsefid,IRON-70-7053-7 and NORIN-22)was primed with hydro-hardening,KCl,CaCl2 and ascorbic acid(AsA)and without a priming agent as a control at low(15℃),optimum(25℃)and high(35℃)germination temperatures.The results showed that the enzymatic and biochemical performances of all the rice genotypes were affected by the seed priming agents,especially under the low germination temperature.At 15℃,seed priming with AsA was found to be the best agent for the activities of amylase,α-amylase,catalase(CAT),peroxidase(POX),ascorbate peroxidase(APOX)and superoxide dismutase(SOD)as well as the content of soluble sugars in the NORIN-22 genotype,and for protease activity and soluble protein content in the IRON-70-7053-7 genotype.SOD at the low germination temperature and CAT,POX and protease at the optimum and high germination temperatures were the most important enzymes in occurrence of germination potential in terms of seedling length,vigor index,normal seedling rate and germination rate.Under the priming agents,the highest changes in normal seedling rate were observed at the low and optimum germination temperatures by AsA priming in the Hashemi and NORIN-22 genotypes,and at the high germination temperature under KCl priming in the Hashemi genotype.展开更多
Reducing the use of animal models in drug development and safety assessment has long been supported by the U.S.Food and Drug Administration(FDA).The report by Royal Society for the Prevention of Cruelty to Animals ind...Reducing the use of animal models in drug development and safety assessment has long been supported by the U.S.Food and Drug Administration(FDA).The report by Royal Society for the Prevention of Cruelty to Animals indicates that in 2020,experiments involved the use of over 100 million animals,with the United States leading the list by utilizing 20 million animals.Beyond ethical considerations associated with animal testing and the costs in terms of time and money,animal models are not always effective in predicting human reactions to drug exposure.While animal testing has been the traditional method for assessing the safety and efficacy of drugs.展开更多
Multipotent mesenchymal stromal cells [also known as mesenchymal stem cells(MSCs)] are currently being studied as a cell-based treatment for inflammatory disorders. Experimental animal models of human immune-mediated ...Multipotent mesenchymal stromal cells [also known as mesenchymal stem cells(MSCs)] are currently being studied as a cell-based treatment for inflammatory disorders. Experimental animal models of human immune-mediated diseases have been instrumental in establishing their immunosuppressive properties. In this review, we summarize recent studies examining the effectiveness of MSCs as immunotherapy in several widely-studied animal models, including type 1 diabetes, experimental autoimmune arthritis, experimental autoimmune encephalomyelitis, inflammatory bowel disease, graft-vs-host disease, and systemic lupus erythematosus. In addition, we discuss mechanisms identified by which MSCs mediate immune suppression in specific disease models, and potential sources of functional variability of MSCs between studies.展开更多
Background: Mortality outcomes in trials of low-dose computed tomography(CT) screening for lung cancer are inconsistent. This study aimed to evaluate whether CT screening in urban areas of China could reduce lung canc...Background: Mortality outcomes in trials of low-dose computed tomography(CT) screening for lung cancer are inconsistent. This study aimed to evaluate whether CT screening in urban areas of China could reduce lung cancer mortality and to investigate the factors that associate with the screening effect.Methods: A decision tree model with three scenarios(low-dose CT screening, chest X-ray screening, and no screening) was developed to compare screening results in a simulated Chinese urban cohort(100,000 smokers aged45-80 years). Data of participant characteristics were obtained from national registries and epidemiological surveys for estimating lung cancer prevalence. The selection of other tree variables such as sensitivities and specificities of low-dose CT and chest X-ray screening were based on literature research. Differences in lung cancer mortality(primary outcome), false diagnoses, and deaths due to false diagnosis were calculated. Sensitivity analyses were performed to identify the factors that associate with the screening results and to ascertain worst and optimal screening effects considering possible ranges of the variables.Results: Among the 100,000 subjects, there were 448,541, and 591 lung cancer deaths in the low-dose CT, chest X-ray, and no screening scenarios, respectively(17.2% reduction in low-dose CT screening over chest X-ray screening and 24.2% over no screening). The costs of the two screening scenarios were 9387 and 2497 false diagnoses and 7and 2 deaths due to false diagnosis among the 100,000 persons, respectively. The factors that most influenced death reduction with low-dose CT screening over no screening were lung cancer prevalence in the screened cohort, lowdose CT sensitivity, and proportion of early-stage cancers among low-dose CT detected lung cancers. Considering all possibilities, reduction in deaths(relative numbers) with low-dose CT screening in the worst and optimal cases were16(5.4%) and 288(40.2%) over no screening, respectively.Conclusions: In terms of mortality outcomes, our findings favor conducting low-dose CT screening in urban China.However, approaches to reducing false diagnoses and optimizing important screening conditions such as enrollment criteria for screening are highly needed.展开更多
Studies have shown that modified dietary fiber has better physical and chemical properties and functions,and can better play its physiological effects.This paper systematically and comprehensively expounded the applic...Studies have shown that modified dietary fiber has better physical and chemical properties and functions,and can better play its physiological effects.This paper systematically and comprehensively expounded the application progress of chemical separation method,microbial fermentation method,physical method,enzyme method and steam explosion method in dietary fiber modification,and expounded the development prospect of modified dietary fiber,so as to provide reference for further study on development and application of dietary fiber.展开更多
Direct labeling of virus particles is a powerful tool for the visualization of virus–cell interaction events. However, this technique involves the chemical modification of viral proteins that affects viral biological...Direct labeling of virus particles is a powerful tool for the visualization of virus–cell interaction events. However, this technique involves the chemical modification of viral proteins that affects viral biological properties. Here we describe an alternative approach of influenza virus labeling that utilizes Function-Spacer-Lipid(FSL) constructs that can be gently inserted into the virus membrane. We assessed whether labeling with fluorescent(fluo-Ad-DOPE) or biotin-labeled(biot-CMG2-DOPE) probes has any deleterious effect on influenza virus hemagglutinin(HA) receptor specificity, neuraminidase(NA) activity, or replicative ability in vitro. Our data clearly show that neither construct significantly affected influenza virus infectivity or viral affinity to sialyl receptors. Neither construct influenced the NA activities of the influenza viruses tested, except the A/Puerto Rico/8/34(H1N1) strain. Our data indicate that lipid labeling provides a powerful tool to analyze influenza virus infection in vitro.展开更多
The role that free radicals in general and oxygen radicals in particular play in carcinogenesis has attracted considerable attention in recent years. The oxygen radicals are undesirable but inevitable products of aero...The role that free radicals in general and oxygen radicals in particular play in carcinogenesis has attracted considerable attention in recent years. The oxygen radicals are undesirable but inevitable products of aerobic metabolism in the normal living cell. The cellular antioxidant defense system maintains an appropriate balance between necessary oxidative events and those that are excessive. When this critical balance cannot be maintained because of the overloading of the cellularredox system, oxygen radicals can induce cell damage. They can influence carcinogenesis by inducing DN A damage from direct oxidation or indirectly from DNA-binding products of lipid peroxidation. Oxygen radicals can induce conformational changes in the plasma membrane by lipid peroxidation and protein degradation, thus influencing membrane-associated cellular activities. They are capable of affecting membrane-bound protein kinases, growth factors and their receptors, and, therefore, signal transduction and oncogene activation. Thus, the oxygen radicals can have a major influence on oncogenes and oncogenesis. (C)1990 Academic Press.Inc.展开更多
The development and influencing factors of compliance behavior of investigators in clinical trials were explored. According to literature review, a hypothetical model of development of compliance behavior of investiga...The development and influencing factors of compliance behavior of investigators in clinical trials were explored. According to literature review, a hypothetical model of development of compliance behavior of investigators in clinical trials was established, and the influencing factors of compliance behavior of investigators and their interrelationships were studied based on questionnaire survey of five hundred investigators sampled randomly from one hundred clinical trial institutions in China. Cron- bach's alpha coefficient and structural equation modeling were adopted to empirically analyze the re- suits. Six variables in the hypothetical model were included: compliance behavior of investigators, credibility of clinical trial, capability of government regulation, quality control of sponsor, quality con- trol of clinical institution and compliance intention of investigators. Empirical analysis showed that the compliance behavior of investigators in clinical trial was directly affected by compliance intention of investigators, quality control of sponsor and quality control of clinical institution. In addition, credibility of clinical trial and capability of government regulation indirectly affected the compliance behavior of investigators in clinical trial through influencing the compliance intention of investigators, quality con- trol of sponsor and quality control of clinical institution. Quality control of sponsor was affected by credibility of clinical trial and capability of government regulation while quality control of clinical in- stitutinn wan only influenced by capability of government regulation.展开更多
AIM: To characterize the immunogenicity of a hepatitis C virus (HCV) E2 DNA vaccine alone or with a protein vaccine boost in murine and porcine animal models. METHODS: A DNA vaccine expressing a secreted form of H...AIM: To characterize the immunogenicity of a hepatitis C virus (HCV) E2 DNA vaccine alone or with a protein vaccine boost in murine and porcine animal models. METHODS: A DNA vaccine expressing a secreted form of HCV E2 protein was constructed and used to vaccinate mice and piglets with or without boosting with a recombinant E2 protein vaccine formulated with CpG ODN and 10% Emulsigen. The immunogenicity of HCV E2 vaccines was analyzed by ELISA for antibody responses, MTT assay for lymphocyte proliferation, ELISPOT for the number of interferon-γ secreting cells, and cytotoxic T lymphocyte assays. RESULTS: Intradermal injection of E2 DNA vaccine induced strong Th1-1ike immune responses in mice. In piglets, E2 DNA vaccine elicited moderate and more balanced immune responses. A DNA vaccine prime and protein boost vaccination strategy induced significantly higher E2-specific antibody levels and shifted the immune response towards Th2-1ike ones in piglets. CONCLUSION: A DNA vaccine expressing a secreted form of HCV E2 protein elicited E2-specific immune responses in mice and piglets. Recombinant E2 protein vaccination following DNA immunization significantly increased the antibody response in piglets. These HCV E2 vaccines may represent promising hepatitis C vaccine candidates for further investigations.展开更多
Hydatidosis is a zoonotic disease caused by the larval stage of Echinococcus granulosus, hydatidosis an important helminthzoonosis affecting sheep in the world. Hydatidosis is a wellknown disease in third world countr...Hydatidosis is a zoonotic disease caused by the larval stage of Echinococcus granulosus, hydatidosis an important helminthzoonosis affecting sheep in the world. Hydatidosis is a wellknown disease in third world countries, especially in rural communities where humans live in close contact with domestic animals and dogs. Dogs act as intermediate hosts. The Al Taif city is about 90 kilometers away from mecca the holy city. In each year, millions of sheep and goats are slaughtered during the pilgrimage season. It is very important to assess the prevalence of hydatidosis since it can be transmitted through dogs which act as definitive hosts for the parasite. This study aims to determine the prevalence of hydatidosis and the fertility/sterility rates of hydatid cysts in sheep and goats slaughtered in Taif Abattoir, Kingdom of Saudi Arabia. In this study, 1098 sheep and 296 goats were examined;162 (13.5%) sheep and 18 (6.1%) goats were found harboring hydatid cysts. In goats 6% were harboring hydaated cyst, and 76% of the goat were of local origin. Differences in prevalence rates were highly significant展开更多
With the development of medicine,people are becoming more and more aware of the quality of medical water supply,such as dial ysis water,dental water,preparation water,operating room water,supply room water.Therefore,P...With the development of medicine,people are becoming more and more aware of the quality of medical water supply,such as dial ysis water,dental water,preparation water,operating room water,supply room water.Therefore,People are constantly improving the water treatment system and its standardized,and the demand for dialysis water is also becoming more and more strict.Hemodialysis is an effective means of maintaining the life of renal failure patients,120~180L water will be used for a conventional dialysis treatment,and high flux dialysis will consume more.展开更多
One of the well-defined sexually dimorphic structures in the brain is the sexually dimorphic nucleus, a cluster of cells located in the preoptic area of the hypothalamus. The rodent sexually dimorphic nucleus of the p...One of the well-defined sexually dimorphic structures in the brain is the sexually dimorphic nucleus, a cluster of cells located in the preoptic area of the hypothalamus. The rodent sexually dimorphic nucleus of the preoptic area can be delineated histologically using conventional Nissl staining or immunohistochemically using calbindin D28K immunoreactivity. There is increasing use of the cal- bindin D28K-delineated neural cluster to define the sexually dimorphic nucleus of the preoptic area in rodents. Several mechanisms are proposed to underlie the processes that contribute to the sexual dimorphism (size difference) of the sexually dimorphic nucleus of the preoptic area. Recent evidence indicates that stem cell activity, including proliferation and migration presumably from the 3^rd ventricle stem cell niche, may play a critical role in the postnatal development of the sexually dimorphic nucleus of the preoptic area and its distinguishing sexually dimorphic feature: a signifi-cantly larger volume in males. Sex hormones and estrogen-like compounds can affect the size of the sexually dimorphic nucleus of the preoptic area. Despite considerable research, it remains un-clear whether estrogen-like compounds and/or sex hormones increase size of the sexually dimor-phic nucleus of the preoptic area via an increase in stem cell activity originating from the 3^rd ventricle stern cell niche.展开更多
Recently,generic drug products have played an increasingly important role in the health care system globally,especially in the developing world,as they provide for an effective and more affordable alternative for heal...Recently,generic drug products have played an increasingly important role in the health care system globally,especially in the developing world,as they provide for an effective and more affordable alternative for healthcare professionals.Generic drug products are proven therapeutically equivalent to the corresponding innovator’s product,and hence can be substituted in clinical practice.The objective of generic drug development is to develop a stable and bioequivalent generic drug product with desirable properties in a timely manner.This presentation is intended to summarize three important sequential stages essential for successful generic drug development based on a regulatory experience in reviewing and evaluating the Pharmaceutical Development Section(P2)of the ASEAN Common Technical Dossier(ACTD)of generic drug product applications submitted to the Food and Drug Administration,Thailand[1,2].展开更多
文摘1. Introduction Drug-induced liver injury (DILI), defined as liver injury caused by a drug and/or its metabolites, is a common clinical adverse drug reaction1–4. This type of injury can cause acute liver failure and even death in severe cases5.
文摘Listeria monocytogenes is an important foodborne pathogen responsible for listeriosis,a fatal disease.It is widely distributed in various foods and environmental sources.In this review,we focused on addressing PCR-based technologies,including conventional PCR,qPCR and droplet digital PCR(ddPCR).Specifically,we described(a)conventional PCR and mono-,duplex-and multiplex-qPCR methodologies;(b)development and applications of gene HlyA-,Iap-,PrfA–and SsrA-based conventional and qPCR assays as well as PCR assays targeting newly identified gene targets for specific detection of L.monocytogenes;differentiation of viable from dead L.monocytogenes by qPCR in conjugation with propidium monoazide pretreatment;PCR-based serotype identification of L.monocytogenes isolates;PCR-based detection of L.ivanovii,infecting ruminants,differentiation of L.monocytogenes from other Listeria species;and sigB-gene based PCR identification of Listeria spp;(c)applications of ddPCR in detection of L.monocytogenes;and(d)application of qPCR assays in detection and subtyping of L.monocytogenes in milk and dairy products;meats,meat products and meat-processing environment;and seafood,seafood products and processing environment.Our goal was to provide a relatively comprehensive overview of PCR-based methodologies available in detection,characterization and subtyping of various strains of L.monocytogenes in foods and environmental sources.
文摘Listeria monocytogenes,one of the most important foodborne pathogens,can cause listeriosis,a lethal disease for humans.L.ivanovii,which is closely related to L.monocytogenes,is also widely distributed in nature and infects mainly warm-blooded ruminants,causing economic loss.Thus,there are high priority needs for methodologies for rapid,specific,cost-effective and accurate detection,characterization and subtyping of L.monocytogenes and L.ivanovii in foods and environmental sources.In this review,we(A)described L.monocytogenes and L.ivanovii,world-wide incidence of listeriosis,and prevalence of various L.monocytogenes strains in food and environmental sources;(B)comprehensively reviewed different types of traditional and newly developed methodologies,including culture-based,antigen/antibody-based,LOOP-mediated isothermal amplification,matrix-assisted laser desorption ionization-time of flight-mass spectrometry,DNA microarray,and genomic sequencing for detection and characterization of L.monocytogenes in foods and environmental sources;(C)comprehensively summarized different subtyping methodologies,including pulsed-field gel electrophoresis,multi-locus sequence typing,ribotyping,and phage-typing,and whole genomic sequencing etc.for subtyping of L.monocytogenes strains from food and environmental sources;and(D)described the applications of these methodologies in detection and subtyping of L.monocytogenes in foods and food processing facilities.
文摘Objective: To refine the infectious doses of enteric bacterial pathogens in animal assays and vaccine clinical trials by studying the invasion kinetics of five bacterial pathogens with human intestinal cells.Methods: Utilizing in vitro cultured cell invasion assays with gentamicin-killing step,the invasive effects were analyzed in foodborne pathogens including Salmonella,Shigella, Yersinia, Escherichia coli(E. coli) O157 and opportunistic pathogens Citrobacter in human embryonic intestine 407 cells and ileocecum HCT-8 cells at multiplicities of infection(MOIs) of 0.04–4 000.00 E. coli HS served as a noninvasive control.Results: The study results showed that the bacterial invasive efficiency and the average number of internalized bacteria per host cell changed with different starting MOIs. Higher starting MOIs did not always produce more bacterial internalization. The bacterial invasion effects varied with different bacterial strains and host cell lines. E. coli O157:H7 did invade human ileocecum HCT-8 cells.Conclusions: This study shows that these bacteria possess different invasive patterns at various starting MOIs and also in different cell lines. The results could help to figure out the appropriate infectious doses of the bacteria in animal assays and in vaccine clinical trials. The bacterial invasion kinetics is also valuable in evaluating the safety and efficacy of live attenuated bacterial vaccines.
文摘Sand production from loosely consolidated reservoirs is one of the critical issues in the oil and gas in-dustry all around the world that can cause many problems,such as erosion of surface and well equip-ment,sand accumulation in wells and operation facilities,buckling of casing in cased-hole wells and well productivity reduction.Sand production control methods include restrictive production rate,mechanical methods(slotted liner,wire-wrapped screen,pre-packed screen,frac-pack,gravel pack,high-rate water pack)and chemical consolidation that chemical method is considered for more effectiveness in sand production alleviation due to increasing formation strength in near wellbore region.This review provides an overview on the laboratory and filed operation investigations of chemical remedy for sand production.Some used chemical agents and more common laboratory tests for evaluating the chemical performance in sand consolidation are introduced in this paper.Furthermore,the results of field operations and in-jections of chemicals into the desired formation are also reported.These results show that the chemical sand consolidation is more effective in newly perforated wells which have no sand production experi-ence and have a production history of less than two years.Finally,it was concluded that the main challenges in applying this method are permeability and capillary force reduction around the wellbore and selective injection into the targeted formation layers.
基金financially supported by the Offi ce of Research and Standards, Office of Generic Drugs, CDER at the FDA (75F40120C00055)
文摘Amphotericin B(AmB)is an amphiphilic drug commonly formulated in liposomes and administered intravenously to treat systemic fungal infections.Recent studies on the liposomal drug product have shed light on the AmB aggregation status in the bilayer,which heat treatment(curing)modifies.Although toxicity was found related to aggregation status-loose aggregates significantly more toxic than tight aggregates-the precise mechanism linking aggregation and toxicitywas notwell understood.This study directlymeasured drug release rate fromvarious AmB liposomal preparations made with modified curing protocols to evaluate correlations among drug aggregation state,drug release,and in vitro toxicity.UV–Vis spectroscopy of these products detected unique curing-induced changes in the UV spectral features:a∼25nm blue-shift of the main absorption peak(λ_(max))in aqueous buffer and a decrease in the OD_(346)/OD_(322) ratio upon thermal curing,reflecting tighter aggregation.In vitro release testing(IVRT)data showed,by applying and fitting first-order release kinetic models for one or two pools,that curing impacts two significant changes:a 3–5-fold drop in the overall drug release rate and a ten-fold decrease in the ratio between the loosely aggregated and the tightly aggregated,more thermodynamically stable drug pool.The kinetic data thus corroborated the trend independently deduced from the UV–Vis spectral data.The in vitro toxicity assay indicated a decreased toxicity with curing,as shown by the significantly increased concentration,causing half-maximal potassium release(TC50).The data suggest that the release of AmB requires dissociation of the tight complexes within the bilayer and that the reduced toxicity relates to this slower rate of dissociation.This study demonstrates the relationship between AmB aggregation status within the lipid bilayer and drug release(directly measured rate constants),providing a mechanistic link between aggregation status and in vitro toxicity in the liposomal formulations.
文摘A simple efficient isocratic reversed-phase HPLC method was developed and validated for the determination of clindamycin palmitate hydrochloride (CPH) and its commercially available oral solution products. Separation was achieved on a Phenomenex Zorbax (Luna) cyano column (150 × 4.6 mm, 5 μm) with a Phenomenex cyano guard cartridge (4 × 3.0 mm) on Agilent 1050 series HPLC system. CPH and its resolution standard lincomycin were eluted isocratically at a flow rate of 1 mL/min with a simplified mobile phase (potassium phosphate buffer (5 mM, pH 3.0)—acetonitrile—tetrahydrofuran (20:75:5, v/v/v)) and detected at 210 nm. The column was maintained at 25?C. The method was validated according to USP category I requirements. Robustness and forced degradation studies were also conducted. CPH marketed drug products were obtained from a drug distributor and assayed for potency using the validated method. Validation acceptance criteria were met in all cases. The analytical range for CPH was 15 - 500 μg/mL and the linearity was r2 > 0.999 over three days. The method was determined to be specific and robust. Both accuracy (92.0% - 103.8%) and precision (0.67% - 1.52%) were established across the analytical range for low, intermediate and high QC concentrations. Method applicability was demonstrated by analyzing two marketed products of CPH, in which results showed potency >98%. The method was determined to be an enhancement over the current USP methodology for assay as a result of increased efficiency, reduced organic solvents and the elimination of matrix modifiers. This method was successfully applied for the quality assessment of: 1) currently marketed drug products and 2) will in future assess the product quality of novel dosage forms of CPH for pediatric use.
基金supported by the Gorgan University of Agricultural Sciences and Natural ResourcesSabz Fanavaran Loozan Shomal Company+1 种基金University of GuilanGuilan Science and Technology Park, Iran
文摘As an abiotic stress,adverse germination temperatures cause serious disruptions in physiological and biochemical processes involved in seed germination.Using a factorial experiment,we examined the effects of different seed priming treatments on enzymatic and biochemical performances of rice seed germination under different temperatures.Each of the rice genotypes(Hashemi,Sadry-domsefid,IRON-70-7053-7 and NORIN-22)was primed with hydro-hardening,KCl,CaCl2 and ascorbic acid(AsA)and without a priming agent as a control at low(15℃),optimum(25℃)and high(35℃)germination temperatures.The results showed that the enzymatic and biochemical performances of all the rice genotypes were affected by the seed priming agents,especially under the low germination temperature.At 15℃,seed priming with AsA was found to be the best agent for the activities of amylase,α-amylase,catalase(CAT),peroxidase(POX),ascorbate peroxidase(APOX)and superoxide dismutase(SOD)as well as the content of soluble sugars in the NORIN-22 genotype,and for protease activity and soluble protein content in the IRON-70-7053-7 genotype.SOD at the low germination temperature and CAT,POX and protease at the optimum and high germination temperatures were the most important enzymes in occurrence of germination potential in terms of seedling length,vigor index,normal seedling rate and germination rate.Under the priming agents,the highest changes in normal seedling rate were observed at the low and optimum germination temperatures by AsA priming in the Hashemi and NORIN-22 genotypes,and at the high germination temperature under KCl priming in the Hashemi genotype.
文摘Reducing the use of animal models in drug development and safety assessment has long been supported by the U.S.Food and Drug Administration(FDA).The report by Royal Society for the Prevention of Cruelty to Animals indicates that in 2020,experiments involved the use of over 100 million animals,with the United States leading the list by utilizing 20 million animals.Beyond ethical considerations associated with animal testing and the costs in terms of time and money,animal models are not always effective in predicting human reactions to drug exposure.While animal testing has been the traditional method for assessing the safety and efficacy of drugs.
基金The FDA Modernizing Science grant programthe FDA MCMi program+1 种基金the Division of Cellular and Gene Therapiessupported through fellowship administered by the Oak Ridge Institute for Science and Education
文摘Multipotent mesenchymal stromal cells [also known as mesenchymal stem cells(MSCs)] are currently being studied as a cell-based treatment for inflammatory disorders. Experimental animal models of human immune-mediated diseases have been instrumental in establishing their immunosuppressive properties. In this review, we summarize recent studies examining the effectiveness of MSCs as immunotherapy in several widely-studied animal models, including type 1 diabetes, experimental autoimmune arthritis, experimental autoimmune encephalomyelitis, inflammatory bowel disease, graft-vs-host disease, and systemic lupus erythematosus. In addition, we discuss mechanisms identified by which MSCs mediate immune suppression in specific disease models, and potential sources of functional variability of MSCs between studies.
基金supported by Peking Union Medical College Youth Fund and the Fundamental Research Funds for the Central Universities(No.2017310049)
文摘Background: Mortality outcomes in trials of low-dose computed tomography(CT) screening for lung cancer are inconsistent. This study aimed to evaluate whether CT screening in urban areas of China could reduce lung cancer mortality and to investigate the factors that associate with the screening effect.Methods: A decision tree model with three scenarios(low-dose CT screening, chest X-ray screening, and no screening) was developed to compare screening results in a simulated Chinese urban cohort(100,000 smokers aged45-80 years). Data of participant characteristics were obtained from national registries and epidemiological surveys for estimating lung cancer prevalence. The selection of other tree variables such as sensitivities and specificities of low-dose CT and chest X-ray screening were based on literature research. Differences in lung cancer mortality(primary outcome), false diagnoses, and deaths due to false diagnosis were calculated. Sensitivity analyses were performed to identify the factors that associate with the screening results and to ascertain worst and optimal screening effects considering possible ranges of the variables.Results: Among the 100,000 subjects, there were 448,541, and 591 lung cancer deaths in the low-dose CT, chest X-ray, and no screening scenarios, respectively(17.2% reduction in low-dose CT screening over chest X-ray screening and 24.2% over no screening). The costs of the two screening scenarios were 9387 and 2497 false diagnoses and 7and 2 deaths due to false diagnosis among the 100,000 persons, respectively. The factors that most influenced death reduction with low-dose CT screening over no screening were lung cancer prevalence in the screened cohort, lowdose CT sensitivity, and proportion of early-stage cancers among low-dose CT detected lung cancers. Considering all possibilities, reduction in deaths(relative numbers) with low-dose CT screening in the worst and optimal cases were16(5.4%) and 288(40.2%) over no screening, respectively.Conclusions: In terms of mortality outcomes, our findings favor conducting low-dose CT screening in urban China.However, approaches to reducing false diagnoses and optimizing important screening conditions such as enrollment criteria for screening are highly needed.
基金Supported by the Key Basic Research Project of Applied Basic Research Plan in Heibei Province(17967502D)
文摘Studies have shown that modified dietary fiber has better physical and chemical properties and functions,and can better play its physiological effects.This paper systematically and comprehensively expounded the application progress of chemical separation method,microbial fermentation method,physical method,enzyme method and steam explosion method in dietary fiber modification,and expounded the development prospect of modified dietary fiber,so as to provide reference for further study on development and application of dietary fiber.
基金partially(NVB) supported by RAS Presidium Grant "Molecular and Cell Biology"
文摘Direct labeling of virus particles is a powerful tool for the visualization of virus–cell interaction events. However, this technique involves the chemical modification of viral proteins that affects viral biological properties. Here we describe an alternative approach of influenza virus labeling that utilizes Function-Spacer-Lipid(FSL) constructs that can be gently inserted into the virus membrane. We assessed whether labeling with fluorescent(fluo-Ad-DOPE) or biotin-labeled(biot-CMG2-DOPE) probes has any deleterious effect on influenza virus hemagglutinin(HA) receptor specificity, neuraminidase(NA) activity, or replicative ability in vitro. Our data clearly show that neither construct significantly affected influenza virus infectivity or viral affinity to sialyl receptors. Neither construct influenced the NA activities of the influenza viruses tested, except the A/Puerto Rico/8/34(H1N1) strain. Our data indicate that lipid labeling provides a powerful tool to analyze influenza virus infection in vitro.
文摘The role that free radicals in general and oxygen radicals in particular play in carcinogenesis has attracted considerable attention in recent years. The oxygen radicals are undesirable but inevitable products of aerobic metabolism in the normal living cell. The cellular antioxidant defense system maintains an appropriate balance between necessary oxidative events and those that are excessive. When this critical balance cannot be maintained because of the overloading of the cellularredox system, oxygen radicals can induce cell damage. They can influence carcinogenesis by inducing DN A damage from direct oxidation or indirectly from DNA-binding products of lipid peroxidation. Oxygen radicals can induce conformational changes in the plasma membrane by lipid peroxidation and protein degradation, thus influencing membrane-associated cellular activities. They are capable of affecting membrane-bound protein kinases, growth factors and their receptors, and, therefore, signal transduction and oncogene activation. Thus, the oxygen radicals can have a major influence on oncogenes and oncogenesis. (C)1990 Academic Press.Inc.
文摘The development and influencing factors of compliance behavior of investigators in clinical trials were explored. According to literature review, a hypothetical model of development of compliance behavior of investigators in clinical trials was established, and the influencing factors of compliance behavior of investigators and their interrelationships were studied based on questionnaire survey of five hundred investigators sampled randomly from one hundred clinical trial institutions in China. Cron- bach's alpha coefficient and structural equation modeling were adopted to empirically analyze the re- suits. Six variables in the hypothetical model were included: compliance behavior of investigators, credibility of clinical trial, capability of government regulation, quality control of sponsor, quality con- trol of clinical institution and compliance intention of investigators. Empirical analysis showed that the compliance behavior of investigators in clinical trial was directly affected by compliance intention of investigators, quality control of sponsor and quality control of clinical institution. In addition, credibility of clinical trial and capability of government regulation indirectly affected the compliance behavior of investigators in clinical trial through influencing the compliance intention of investigators, quality con- trol of sponsor and quality control of clinical institution. Quality control of sponsor was affected by credibility of clinical trial and capability of government regulation while quality control of clinical in- stitutinn wan only influenced by capability of government regulation.
基金Supported by the Canadian Network for Vaccines and Immuno-therapeutics
文摘AIM: To characterize the immunogenicity of a hepatitis C virus (HCV) E2 DNA vaccine alone or with a protein vaccine boost in murine and porcine animal models. METHODS: A DNA vaccine expressing a secreted form of HCV E2 protein was constructed and used to vaccinate mice and piglets with or without boosting with a recombinant E2 protein vaccine formulated with CpG ODN and 10% Emulsigen. The immunogenicity of HCV E2 vaccines was analyzed by ELISA for antibody responses, MTT assay for lymphocyte proliferation, ELISPOT for the number of interferon-γ secreting cells, and cytotoxic T lymphocyte assays. RESULTS: Intradermal injection of E2 DNA vaccine induced strong Th1-1ike immune responses in mice. In piglets, E2 DNA vaccine elicited moderate and more balanced immune responses. A DNA vaccine prime and protein boost vaccination strategy induced significantly higher E2-specific antibody levels and shifted the immune response towards Th2-1ike ones in piglets. CONCLUSION: A DNA vaccine expressing a secreted form of HCV E2 protein elicited E2-specific immune responses in mice and piglets. Recombinant E2 protein vaccination following DNA immunization significantly increased the antibody response in piglets. These HCV E2 vaccines may represent promising hepatitis C vaccine candidates for further investigations.
文摘Hydatidosis is a zoonotic disease caused by the larval stage of Echinococcus granulosus, hydatidosis an important helminthzoonosis affecting sheep in the world. Hydatidosis is a wellknown disease in third world countries, especially in rural communities where humans live in close contact with domestic animals and dogs. Dogs act as intermediate hosts. The Al Taif city is about 90 kilometers away from mecca the holy city. In each year, millions of sheep and goats are slaughtered during the pilgrimage season. It is very important to assess the prevalence of hydatidosis since it can be transmitted through dogs which act as definitive hosts for the parasite. This study aims to determine the prevalence of hydatidosis and the fertility/sterility rates of hydatid cysts in sheep and goats slaughtered in Taif Abattoir, Kingdom of Saudi Arabia. In this study, 1098 sheep and 296 goats were examined;162 (13.5%) sheep and 18 (6.1%) goats were found harboring hydatid cysts. In goats 6% were harboring hydaated cyst, and 76% of the goat were of local origin. Differences in prevalence rates were highly significant
基金Guangdong Obers Blood Purification Aca demician Work station(2013B090400004)Science and technology plan project of Guangdong industrial high and new technology field(2013B010203019)+3 种基金Guangzhou entrepreneurial leader talent/LCY201215Guangdong Inno vation Fund Project(2014A010101123)Guangdong Provincial Center for clinical en gineering of blood purification(507204531040)Guangdong University blood purification technology and Engineering Research Center(GCZX-A1104)
文摘With the development of medicine,people are becoming more and more aware of the quality of medical water supply,such as dial ysis water,dental water,preparation water,operating room water,supply room water.Therefore,People are constantly improving the water treatment system and its standardized,and the demand for dialysis water is also becoming more and more strict.Hemodialysis is an effective means of maintaining the life of renal failure patients,120~180L water will be used for a conventional dialysis treatment,and high flux dialysis will consume more.
基金supported by the National Center for Toxicological Research/FDA(Protocol P00710 to He Z and Protocol P00706 to Ferguson SA)supported by UAMS Hornick Award+1 种基金NIH Grant R01-NS049389UAMS institutional funds
文摘One of the well-defined sexually dimorphic structures in the brain is the sexually dimorphic nucleus, a cluster of cells located in the preoptic area of the hypothalamus. The rodent sexually dimorphic nucleus of the preoptic area can be delineated histologically using conventional Nissl staining or immunohistochemically using calbindin D28K immunoreactivity. There is increasing use of the cal- bindin D28K-delineated neural cluster to define the sexually dimorphic nucleus of the preoptic area in rodents. Several mechanisms are proposed to underlie the processes that contribute to the sexual dimorphism (size difference) of the sexually dimorphic nucleus of the preoptic area. Recent evidence indicates that stem cell activity, including proliferation and migration presumably from the 3^rd ventricle stem cell niche, may play a critical role in the postnatal development of the sexually dimorphic nucleus of the preoptic area and its distinguishing sexually dimorphic feature: a signifi-cantly larger volume in males. Sex hormones and estrogen-like compounds can affect the size of the sexually dimorphic nucleus of the preoptic area. Despite considerable research, it remains un-clear whether estrogen-like compounds and/or sex hormones increase size of the sexually dimor-phic nucleus of the preoptic area via an increase in stem cell activity originating from the 3^rd ventricle stern cell niche.
文摘Recently,generic drug products have played an increasingly important role in the health care system globally,especially in the developing world,as they provide for an effective and more affordable alternative for healthcare professionals.Generic drug products are proven therapeutically equivalent to the corresponding innovator’s product,and hence can be substituted in clinical practice.The objective of generic drug development is to develop a stable and bioequivalent generic drug product with desirable properties in a timely manner.This presentation is intended to summarize three important sequential stages essential for successful generic drug development based on a regulatory experience in reviewing and evaluating the Pharmaceutical Development Section(P2)of the ASEAN Common Technical Dossier(ACTD)of generic drug product applications submitted to the Food and Drug Administration,Thailand[1,2].