Extensive Screening Process Research Articles

Design, Synthesis and Anti‐Cancer Evaluation of Quinoline‐1,2,4‐triazine Hybrids

AbstractNine quinoline‐1,2,4‐triazine hybrids (5 a–5 i) were designed, synthesized, and subjected to evaluation as potential anti‐cancer agents. Structures validation of the synthesized analogues was accomplished through comprehensive analysis employing NMR, HRMS, and IR spectroscopy techniques. Furthermore, the molecular structures of compounds 5 a, 5 d and 5 h were authenticated via single crystal X‐ray diffraction. In an extensive screening process against the human pancreatic cancer PANC‐1 cell line utilizing the MTT assay, all quinoline‐1,2,4‐triazine hybrids (5 a–5 i) manifested significant anti‐proliferative activity. Compound 5 g demonstrated a significant anti‐proliferative effect with an IC50 value of 26.8 μM, similar to the positive control, 5‐Fu. Subsequent investigations revealed varying degrees of cell viability in MDA‐MB‐231, A549, and UM‐UC‐3 cell lines upon exposure to different concentrations of compound 5 g. These findings lead us to postulate that compound 5 g may impede the migration, invasion, and adhesion of PANC‐1 cells, similar to the effects observed with 5‐Fu.

Systematic overview of intraosseous access versus intravenous delivery for emergency resuscitation: Efficacy and quality of existing evidence.

The impact of intraosseous (IO) access on resuscitation outcomes, as compared to intravenous (IV) administration, is subject to ongoing debate. This review aims to provide a comprehensive evaluation of the methodological, reporting, and evidence quality of existing Systematic Reviews/Meta-Analyses (SRs/MAs) on IO use during resuscitation. Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, we conducted a strategic literature search to identify pertinent SRs/MAs published up until May 6th, 2023. After an extensive screening process, 4 SRs/MAs were included for review. We used the A Measurement Tool to Assess Systematic Reviews-2 tool for assessing methodological quality, the Preferred Reporting Items for Systematic Reviews and Meta-Analyses checklist for evaluating reporting quality, and the Grading of Recommendations Assessment, Development, and Evaluation framework for examining the quality of evidence. The assessment revealed high methodological quality across all the included SRs/MAs but showed significant variability in the quality of evidence. The studies offered conflicting findings on the impact of IO access on resuscitation outcomes such as return of spontaneous circulation, survival rates at hospital discharge, and favorable neurological outcomes. Some studies suggested an association of IO access with poorer outcomes, while others indicated no significant difference between IO and IV routes. Despite the perceived utility of IO access when IV access is unachievable, the impact of IO on survival, return of spontaneous circulation, and neurological outcomes remains ambiguous due to the inconsistency in the existing evidence. This review underscores the critical need for more rigorous and consistent primary research in this area to strengthen clinical guidelines and improve patient outcomes.

Standardized Iterative Genome Editing Method for Escherichia coli Based on CRISPR-Cas9.

The introduction of complex biosynthetic pathways into the hosts' chromosomes is gaining attention with the development of synthetic biology. While CRISPR-Cas9 has been widely employed for gene knock-in, the process of multigene insertion remains cumbersome due to laborious and empirical gene cloning procedures. To address this, we devised a standardized iterative genome editing system for Escherichia coli, harnessing the power of CRISPR-Cas9 and MetClo assembly. This comprehensive toolkit comprises two fundamental elements based on the Golden Gate standard for modular assembly of sgRNA or CRISPR arrays and donor DNAs. We achieved a gene insertion efficiency of up to 100%, targeting a single locus. Expression of tracrRNA using a strong promoter enhances multiplex genomic insertion efficiency to 7.3%, compared with 0.76% when a native promoter is used. To demonstrate the robust capabilities of this genome editing toolbox, we successfully integrated 5-10 genes from the coenzyme B12 biosynthetic pathway ranging from 5.3 to 8 Kb in length into the chromosome of E. coli chassis cells, resulting in 14 antibiotic-free, plasmid-free producers. Following an extensive screening process involving genes from diverse sources, cistronic design modifications, and chromosome repositioning, we obtained a recombinant strain yielding 1.49 mg L-1 coenzyme B12, the highest known titer achieved by using E. coli as the producer. Illuminating its user-friendliness, this genome editing system is an exceedingly versatile tool for expediently integrating complex biosynthetic pathway genes into hosts' genomes, thus facilitating pathway optimization for chemical production.

Diterpenoid honatisine overcomes temozolomide resistance in glioblastoma by inducing mitonuclear protein imbalance through disruption of TFAM-mediated mtDNA transcription

BackgroundGlioblastoma (GBM) represents as the most formidable intracranial malignancy. The systematic exploration of natural compounds for their potential applications in GBM therapy has emerged as a pivotal and fruitful avenue of research. PurposeIn the present study, a panel of 96 diterpenoids was systematically evaluated as a repository of potential antitumour agents. The primary objective was to discern their potency in overcoming resistance to temozolomide (TMZ). Through an extensive screening process, honatisine, a heptacyclic diterpenoid alkaloid, emerged as the most robust candidate. Notably, honatisine exhibited remarkable efficacy in patient-derived primary and recurrent GBM strains. Subsequently, we subjected this compound to comprehensive scrutiny, encompassing GBM cultured spheres, GBM organoids (GBOs), TMZ-resistant GBM cell lines, and orthotopic xenograft mouse models of GBM cells. ResultsOur investigative efforts delved into the mechanistic underpinnings of honatisine's impact. It was discerned that honatisine prompted mitonuclear protein imbalance and elicited the mitochondrial unfolded protein response (UPRmt). This effect was mediated through the selective depletion of mitochondrial DNA (mtDNA)-encoded subunits, with a particular emphasis on the diminution of mitochondrial transcription factor A (TFAM). The ultimate outcome was the instigation of deleterious mitochondrial dysfunction, culminating in apoptosis. Molecular docking and surface plasmon resonance (SPR) experiments validated honatisine's binding affinity to TFAM within its HMG-box B domain. This binding may promote phosphorylation of TFAM and obstruct the interaction of TFAM bound to heavy strand promoter 1 (HSP1), thereby enhancing Lon-mediated TFAM degradation. Finally, in vivo experiments confirmed honatisine's antiglioma properties. Our comprehensive toxicological assessments underscored its mild toxicity profile, emphasizing the necessity for a thorough evaluation of honatisine as a novel antiglioma agent. ConclusionIn summary, our data provide new insights into the therapeutic mechanisms underlying honatisine's selective inducetion of apoptosis and its ability to overcome chemotherapy resistance in GBM. These actions are mediated through the disruption of mitochondrial proteostasis and function, achieved by the inhibition of TFAM-mediated mtDNA transcription. This study highlights honatisine's potential as a promising agent for glioblastoma therapy, underscoring the need for further exploration and investigation.

Evaluating the Serum Markers for Early Diagnosis of HCV Induced Hepatocellular Carcinoma

Hepatocellular carcinoma is a global public health problem which is intensified at developing countries due to lack of early diagnosis. Since Hepatitis C virus related morbidity accounts five million people in Pakistan, rate of morbidity and mortality of HCV related Hepatocellular carcinoma infections is high in Pakistan, and it is attributed to its diagnosis after its development. The public has the lack of awareness about the importance and benefits of liver biopsy testing; therefore, improved, and non-invasive methods of HCC diagnosis are urgently needed. The aim of the present study was to evaluate the importance of serum markers in early diagnosis of HCV induced Hepatocellular carcinoma and to develop a robust set of serological markers for their early detection and diagnosis. A total of 60 HCV positive patients including Chronic Liver disease (n=20), Cirrhosis (n=20), HCC patients (n=20) and 20 healthy volunteers (n=20) were enrolled in this study after an extensive screening process. Blood samples were collected from all the subjects and processed for serum separation followed by immunological, molecular, and biochemical analysis using Enzyme Linked Immunosorbant Assay, Real-Time PCR, complete blood picture, and a range of biochemical tests. Results showed gender wise variability among the subjects from each of the study groups where in the male subjects remained dominant with male and female ratio as 61.75:38.75. The average age of male subjects was observed between 42y, 43y, 49y and 37 years in comparison of female subjects who were 46y, 53y, 50y and 47y in CLD, cirrhosis, Hepatocellular carcinoma, and control groups, respectively. The data has also demonstrated that Hepatocellular carcinoma patients having Alpha Fetoprotein level >1000 showed the increased level of ALP and GGT with decreased HB and HCT. However, the Hepatocellular carcinoma patients having AFP level in the range of 100-500 had total bilirubin level > 3.0, while those having AFP level <100 has all serological markers in normal range. In addition, the patients of HCC showed increased PT with decreased albumin level. The increases level of albumin level (>3-<4.0) was observed from the serum samples of cirrhosis and Chronic liver disease patients. The increase in albumin up to 4.0 accompanied with the increased level of ALP and PT while decreased HB. In conclusion, different biochemical parameters may be used to distinguish the patients having Hepatocellular carcinoma from those suffering from cirrhosis and chronic liver disease induced by HCV infection. The findings of present study may help to enhance the outcome for patients with HCC by enabling the diagnosis to be made at an earlier stage of the disease.

Exploring urban transformation to inform the implementation of the Sustainable Development Goals

The Sustainable Development Goals (SDGs) call for rapid transformation towards a more sustainable society, particularly for cities and urban areas. There is a wide spectrum of research which could inform the initiation and management of this urban transformation, but these contributions are found in disparate disciplines and academic fields. This study aims to synthesise the different elements of the ‘Urban Transformation’ (UT) literature into a format which can inform the implementation of the SDGs. Using a systematic qualitative review methodology, the study identified 5150 potentially relevant papers. An extensive screening process was conducted to form a review corpus of 323 studies, upon which an interpretative, iterative content analysis was applied. The analysis resulted in 15 ‘factors of urban transformation’ identified across the literature. These factors are a mix of mechanisms and enablers which are all identified in the literature as critical for urban transformation to occur or continue. By providing a link between the rich urban transformation literature and SDG implementation, the results of this review could be used to explore the transformative potential of current approaches to SDG implementation, or as an initial tool to design new and more transformative pathways to achieve the SDGs in cities.

Comparison of the Validity of the Timed Up and Go Test (TUG) and Activities-specific Balance Confidence Questionnaire (ABC) to the ‘Gold Standard’ Berg Balance Scale (BBS) in Assessing Fall Risk in the Elderly Population

Background: Falls are ranked as the leading cause of death from unintentional injury among older adults in the United States. Approximately 25% of the older adults in the U.S. experience a fall each year, which leads to excessive healthcare costs. Falls lead to serious injuries such as broken bones and head injuries hospitalizing 800,000 patients a year [1]. Based on those statistics, identifying fall risk accurately and efficiently using balance assessments is pertinent to fall prevention in the geriatric population. Therefore, the purpose of this study is to compare the validity of the Timed Up and Go Test (TUG) and Activities-Specific Balance Confidence Questionnaire (ABC) to the Berg Balance Scale (BBS) in assessing the risk of falls in the elderly population. Methods: The systematic review was conducted to highlight balance assessments including the Berg Balance Scale, Timed Up and Go Test, and Activities-specific Balance Confidence Questionnaire. Databases used in the electronic search were PubMed, Google Scholar, MedlinePlus, PTNow, PEDro, and EBSCOhost, and parameters were set at studies published from 2010 to 2021. All relevant studies were reviewed by assessing abstracts for inclusion. Studies in which participants completed and were scored on the three balance assessments were included. All participants completing the tests were required to be 65 years of age or older in order for the respective study to be included. Results: 62 studies were identified for further review after the initial search. After a more extensive screening process, several studies were excluded for reasons such as study design, age of participants, or insufficient testing measures. 16 studies were included for data analysis with a total of 1,376 participants. The validity of the BBS, TUG, and ABC were measured in the 16 studies with strong negative correlation between BBS and TUG (rho (22) = -.756, p < .01), and moderate positive correlation between BBS and ABC (rho (22) = .591, p < .01). Conclusions: The Timed Up and Go test may be an effective and valid tool assessing balance and a participant’s fall risk. It has been shown to have a strong correlation with the Berg Balance Scale. Meanwhile, the Activities-specific Balance Confidence Questionnaire, a subjective measure, has a moderate correlation with the Berg Balance Scale indicating that it is capable of identifying fall risk but not as accurately or efficiently as the Timed Up and Go Test. This research advocates for the appropriateness of the TUG test and ABC questionnaire, and therefore widens clinicians’ choices of valid balance assessment tools during fall risk examinations.

Exploring the impact of the COVID-19 pandemic on pediatric surgical services.

Inevitably, along with other healthcare specializations, pediatric surgery was affected by the Coronavirus disease-19 (COVID-19) pandemic. Children were reported to manifest mild to moderate symptoms and mortality was primarily observed in patients aged <1 year and having underlying comorbidities. Most of the cases were asymptomatic in children, hence, posing a challenge for pediatric surgery centers to take drastic measures to reduce the virus transmission. Telemedicine was introduced and out-patient consultations were conducted online as out-patient clinics were closed. Elective surgeries were postponed with delayed appointments while the healthcare sector was diverted towards tackling COVID-19. Case urgency was classified and triaged, leading to limited surgeries being performed only in COVID-19 negative patients following an extensive screening process. The screening process consisted of online history taking and RT-PCR tests. Newer practices such as mouth rinse, video laryngoscopy, and anesthesia were introduced to restrict patients from crying, coughing, and sneezing, as an attempt to avoid aerosolization of viral particles and safely conduct pediatric surgeries during the pandemic. Surgical trainees were also affected as the smaller number of surgeries conducted reduced the clinical experience available to medical enthusiasts. There is still room for advanced practices to be introduced in pediatric surgery and restore all kinds of surgeries to improve the quality of life of the patient.

Internet-delivered Cognitive Behavioural Therapy for Persons with Mild Traumatic Brain Injury: A Multi-Method Feasibility Trial

<h3>Research Objectives</h3> To deliver a feasibility pilot trial to evaluate the acceptability and limited effectiveness of the internet-delivered cognitive behavioural therapy (ICBT) program that has been designed for persons with mild traumatic brain injury (mTBI) to improve overall well-being. <h3>Design</h3> A mixed-methods feasibility trial will be conducted to evaluate ICBT among persons with mTBI. Data will be collected at three time points, baseline, post-treatment and 3-month follow-up. Post-treatment, participants will complete a brief semi-structured interview examining the barriers and facilitators of the program. <h3>Setting</h3> Participants will be recruited from outpatient brain injury and stroke clinics by their health care providers. <h3>Participants</h3> A priori sample size of 20 has been calculated to be sufficient to detect a power of 90% and alpha at .05 with an effect size of 0.8 and accounted for a potential dropout of 30%. Potential participants will undergo an extensive screening process involving interviews to assess suicide risk and cognitive status. <h3>Interventions</h3> The ICBT program consists of six modules, including lessons on psychoeducation on the mTBI symptoms, managing symptoms of depression and anxiety, with a registered mental health professional contacting them once per week for up to 12 weeks, leading to personalized care. <h3>Main Outcome Measures</h3> The primary outcomes for the study include the feasibility and acceptability of the ICBT program. Secondary outcome measures include depression and anxiety. <h3>Results</h3> It is hypothesized that the ICBT program will be acceptable to participants and improve patient-reported outcomes from baseline to follow-up. Additionally, participants will provide valuable information on the strengths and challenges of the ICBT program to further improve and better serve this population's needs. <h3>Conclusions</h3> This research is expected to significantly improve health outcomes and mental health care delivery for individuals with mTBI and for those with other neurological conditions. The results of this study will guide larger studies to evaluate the program's effectiveness in a community setting. <h3>Author(s) Disclosures</h3> No conflict between any of the authors.

Microbial degradation of azo dyes by textile effluent adapted, Enterobacter hormaechei under microaerophilic condition

Landmark and sustainable eco-friendly dye treatment processes are highly desirous to ameliorate their effect on the environment. The present study investigated the azo dye degradation efficiency of adapted Enterobacter hormaechei SKB 16 from textile effluent polluted soil in optimized culture conditions. The adapted bacteria strain was identified by standard microbiological and molecular techniques. E. hormaechei was tested individually for the decolourizing of Reactive Yellow 145 (RY 145) and Reactive Red F3B (RR 180) dyes under optimized conditions of pH, temperature and dye concentration on decolourization were studied. The adapted bacteria strain exhibited maximum decolourization (98 %) of Reactive yellow 145 and Reactive red 180 in 100 ppm concentration at pH 7, temperature 37 °C after 98 h of incubation. The enzyme analyses revealed that azo reductase and laccase played major roles in the cleavage of the azo bond and desulfonation respectively of both dyes during degradation. The metabolites were further characterized by Fourier Transform Infrared Spectroscopy (FT-IR), High-Performance Liquid Chromatography (HPLC), and Gas Chromatography-Mass Spectrometry (GCMS). Thereafter, degradation was deduced based on changes of the functional group, variation in retention times and mass/charge ratio and molecular weight. This study elucidated the promising potentials of adapted SKB 16 strain in the eco-friendly removal of textile azo dyes. In addition, repeatability and sustainability are enhanced due to effective management of time which would have been spent on rigorous and extensive screening process.

Sudden Cardiac Death in Famous Athletes, Lessons Learned, Heterogeneity in Expert Recommendations and Pitfalls of Contemporary Screening Strategies.

Sudden cardiac death (SCD) in competitive athletes, though relatively uncommon, invariably leads to controversy. Specific limitations of an extensive screening process include lack of robust evidence to support prevention of SCD, poor cost-effectiveness and uncertain downstream implications of a positive screening test. An emerging body of evidence points to enhanced neurologically intact survival to hospital discharge when automated external defibrillators (AEDs) are used in a timely manner following sudden cardiac arrest (SCA). A viable alternative to an expansive screening process could be a robust secondary prevention system comprising of improvements in AED availability, stringent enforcement of CPR training in athletes and trainers to provide timely and effective resuscitation to reduce death following SCA. This strategy could widen the window to diagnose and treat the underlying etiology and prevent recurrence of SCA while also offering financial feasibility. Restricting athletes from competitive sports is a difficult decision for physicians owing to a lack of well-defined cutoffs for acceptable and prohibitive risk from pathology predisposing to SCD, especially in the absence of a protective medico-legal framework. In this review, we highlight a few cases that generated intense scrutiny by the public, media and medical professionals about the efficacy, feasibility and pitfalls of the existing screening process to diagnose cardiovascular pathology predisposing to SCD. Furthermore, contrasting approaches to screening, diagnosis and downstream workup protocols between the European Society of Cardiology and the American Heart Association are analyzed.

Micelles and Bicelles as Membrane Mimics for Membrane Protein Characterization

Micelles and bicelles are used to isolate membrane proteins for biophysical characterization, functional assays, and high-resolution structure determination. Utilizing these membrane mimics requires an extensive screening process to identify the appropriate amphiphilic environment to stabilize a functional membrane protein. To enable rational mimic selection, the goal of this research is to investigate the structural properties of micelles and bicelles to determine how their physical characteristics can forward membrane protein research. Small angle X-ray scattering and small angle neutron scattering were used to investigate the structure of micelles and bicelles, specifically binary mixtures of detergents and lipids. To determine the impact of membrane mimic structure on protein function, outer membrane phospholipase A1, the protease OmpT, and the lipid A palmitoyltransferase PagP were purified in detergent micelles with varying properties, and the overall protein activity was evaluated. Hypotheses based on the correlations between activity and micelle properties were tested using mixed micelles and bicelles with tunable properties. The information gained from these studies will determine the physical properties important in stabilizing membrane proteins and provide guiding principles for selecting membrane mimics.

Alkaline protease from a new halotolerant alkaliphilic Bacillus agaradhaerens strain ak-r isolated from egyptian soda lakes

Alkaline proteases are hydrolytic enzymes that cleave peptide bonds in proteins and peptides in alkaline conditions, which occupy a pivotal importance with respect to their industrial applications. This study aimed to isolate new alkaline protease producing alkaliphilic bacteria from Egyptian soda lakes and optimize the fermentation process to enhance the enzyme production. The extensive screening process of the samples collected from Egyptian soda lakes resulted in isolation of a potent alkaline protease producing alkaliphilic strain AK-R. The isolate was identified as Bacillus agaradhaerens strain AK-R based on 16S rRNA gene analysis (99%). Wheat bran and gelatin supported maximum alkaline protease production as carbon and nitrogen sources, respectively. Strain AK-R is halo-tolerant thermo-tolerant alkaliphilic bacterium in nature, as it can grow over a wide range of NaCl concentrations (up to 25%) and up to 55 °C, with maximal growth and enzyme production at 2.5-5%, and pH 11 at 35 °C. Among the tested cations, only Mg 2+ and Ca 2+ ions significantly enhanced the enzyme production by about 1.2, and 1.3 fold compared to control, respectively. Alkaline protease secretion was coherent with the growth pattern, reaching maximal yield after about 32 h (mid stationary phase). In conclusion a new halo-tolerant thermo-tolerant alkaliphilic alkaline protease producing Bacillus agaradhaerens strain AK-R was isolated from Egyptian soda lakes. Optimization of the nutritional and cultivation conditions resulted in increase of enzyme yield by 20 fold. Strain AK-R and its extracellular alkaline protease with salt, pH and temperature, tolerance signify their potential application in laundry and pharmaceuticals industries.

Overdiagnosis of high-grade dysplasia in Barrett's esophagus: a multicenter, international study

Numerous histological mimics of high-grade dysplasia in Barrett's esophagus predispose to overdiagnosis and potential serious mismanagement, including unnecessary esophagectomy. This study investigates the prevalence and sources of this problem. Biopsies from 485 patients diagnosed with Barrett's high-grade dysplasia were screened for a multi-institutional, international Barrett's endoscopic ablation trial. Screening included review of the original diagnostic slides and an additional protocol endoscopy with an extensive biopsy sampling. Observer variability by the study pathologists was assessed through two blinded diagnostic rounds on 437 biopsies from 26 random study endoscopies. Study diagnostic reassessments revealed significantly lower rates of high-grade dysplasia. Only 248 patients (51%) were confirmed to have high-grade dysplasia. The remaining patients had inflamed gastric cardia without Barrett's (n=18; 7%), Barrett's without dysplasia (n=35; 15%), indefinite change (n=61; 26%), low-grade dysplasia (n=79; 33%), adenocarcinoma (n=43; 18%), and other (n=1; <1%), yielding an alarming total of 194 or 40% of patients who were overdiagnosed with Barrett's high-grade dysplasia. Study pathologists achieved a high-level agreement (90% three-way inter-observer agreement per biopsy, Kappa value 0.77) for high-grade dysplasia. Confounding factors promoting overdiagnosis included Barrett's inflammatory atypia (n=182), atypia limited to the basal metaplastic glands (n=147), imprecise criteria for low grade neoplasia (n=102), tangential sectioning artifact (n=59), and reactive gastric cardiac mucosa (n=38). A total of 194 patients (40%) were overdiagnosed with Barrett's high-grade dysplasia, as affirmed by the extensive screening process and high-level study pathologist agreement. The multiple diagnostic pitfalls uncovered should help raise pathologists' awareness of this problem and improve diagnostic accuracy.

Palladium-catalyzed synthesis of indole-3-alkynones via direct carbonylation of indoles

A new method has been developed for the Pd-catalyzed direct carbonylation of indoles with phenylacetylenes. The process involved the initial iodination of the indole to afford the corresponding 3-iodo-indole, which was subsequently carbonylated with a variety of different alkynes using Pd(0) to yield the indole-3-alkynones. In contrast to the traditional Pd-catalyzed oxidative carbonylation strategy, which involves the Pd(II)-mediated activation of the aromatic C-H bonds, the aromatic C-H bonds in the current process were activated by iodine oxidation, eliminating the problems associated with the reduction of Pd(II) to Pd(0) under the CO atmosphere. Following an extensive screening process, Pd(OAc)2/CuI was identified as the most efficient catalyst system for the reaction in the presence of a base and iodine as an oxidant under mild conditions (0.2 MPa CO, 90 °C). The reaction provided the desired products in moderate to excellent isolated yields (up to 94%) and good tolerance to a variety of different functional groups. The structure of a representative alkynone product (3he) was unambiguously verified by X-ray single crystal structure analysis. Furthermore, the carbonylation products underwent a three-component reaction with sodium azide and benzyl bromide to give the corresponding 1,2,3-triazole analogues in the absence of any catalyst, thus expanding the synthetic application of the current methodology. 采用共合成法制备了一系列不同硅氨基含量的介孔氧化硅 SBA-15, 在其孔道中引入 Keggin 型钨磷酸, 且其含量随硅氨基含量的增加而增加. 考察了不同处理温度下杂多酸的热稳定性, 发现焙烧后钨物种能在 SBA-15 孔道内高度分散. 以 H2O2 为氧化剂, 研究了该催化剂在环己烯环氧化反应中的催化活性, 考察了杂多酸负载量和焙烧温度对催化活性的影响. 结果表明, 400 °C 处理后的钨磷酸催化剂具有高的反应活性和重复使用性能.

MabCent: Arctic marine bioprospecting in Norway

The deep waters surrounding the coastline of the northern parts of Norway represent an exciting biotope for marine exploration. Dark and cold Arctic water generates a hostile environment where the ability to adapt is crucial to survival. These waters are nonetheless bountiful and a diverse plethora of marine organisms thrive in these extreme conditions, many with the help of specialised chemical compounds. In comparison to warmer, perhaps more inviting shallower tropical waters, the Arctic region has not been as thoroughly investigated. MabCent is a Norwegian initiative based in Tromsø that aims to change this. Since 2007, scientists within MabCent have focussed their efforts on the study of marine organisms inhabiting the Arctic waters with the long term goal of novel drug discovery and development. The activities of MabCent are diverse and range from sampling the Arctic ice shelf to the chemical synthesis of promising secondary metabolites discovered during the screening process. The current review will present the MabCent pipeline from isolation to identification of new bioactive marine compounds via an extensive screening process. An overview of the main activities will be given with particular focus on isolation strategies, bioactivity screening and structure determination. Pitfalls, hard earned lessons and the results so far are also discussed.

The Phosphodiesterase-5 Inhibitor Vardenafil Is a Potent Inhibitor of ABCB1/P-Glycoprotein Transporter

One of the major causes of chemotherapy failure in cancer treatment is multidrug resistance (MDR) which is mediated by the ABCB1/P-glycoprotein. Previously, through the use of an extensive screening process, we found that vardenafil, a phosphodiesterase 5 (PDE-5) inhibitor significantly reverses MDR in ABCB1 overexpressing cancer cells, and its efficacy was greater than that of tadalafil, another PDE-5 inhibitor. The present study was designed to determine the reversal mechanisms of vardenafil and tadalafil on ABC transporters-mediated MDR. Vardenafil or tadalafil alone, at concentrations up to 20 µM, had no significant toxic effects on any of the cell lines used in this study, regardless of their membrane transporter status. However, vardenafil when used in combination with anticancer substrates of ABCB1, significantly potentiated their cytotoxicity in ABCB1 overexpressing cells in a concentration-dependent manner, and this effect was greater than that of tadalafil. The sensitivity of the parenteral cell lines to cytotoxic anticancer drugs was not significantly altered by vardenafil. The differential effects of vardenafil and tadalafil appear to be specific for the ABCB1 transporter as both vardenafil and tadalafil had no significant effect on the reversal of drug resistance conferred by ABCC1 (MRP1) and ABCG2 (BCRP) transporters. Vardenafil significantly increased the intracellular accumulation of [3H]-paclitaxel in the ABCB1 overexpressing KB-C2 cells. In addition, vardenafil significantly stimulated the ATPase activity of ABCB1 and inhibited the photolabeling of ABCB1 with [125I]-IAAP. Furthermore, Western blot analysis indicated the incubation of cells with either vardenafil or tadalafil for 72 h did not alter ABCB1 protein expression. Overall, our results suggest that vardenafil reverses ABCB1-mediated MDR by directly blocking the drug efflux function of ABCB1.

Bio-sequestration of carbon dioxide using carbonic anhydrase enzyme purified from Citrobacter freundii

The increase in the atmospheric concentrations of one of the vital green house gasses, carbon dioxide, due to anthropogenic interventions has led to several undesirable consequences such as global warming and related changes. In the global effort to combat the predicted disaster, several CO2 capture and storage technologies are being deliberated. One of the most promising biological carbon dioxide sequestration technologies is the enzyme catalyzed carbon dioxide sequestration into bicarbonates which was endeavored in this study with a purified C. freundii SW3 β-carbonic anhydrase (CA). An extensive screening process for biological sequestration using CA has been defined. Six bacteria with high CA activity were screened out of 102 colonies based on plate assay and presence of CA in these bacteria was further emphasized by activity staining and Western blot. The identity of selected bacteria was confirmed by 16S rDNA analysis. CA was purified to homogeneity from C. freundii SW3 by subsequent gel filtration and ion exchange chromatography which resulted in a 24 kDa polypeptide and this is in accordance with the Western blot results. The effect of host on metal ions, cations and anions which influence activity of the enzyme in sequestration studies suggests that mercury and HCO3 − ion almost completely inhibit the enzyme whereas sulfate ion and zinc enhances carbonic anhydrase activity. Calcium carbonate deposition was observed in calcium chloride solution saturated with carbon dioxide catalyzed by purified enzyme and whereas a sharp decrease in calcium carbonate formation has been noted in purified enzyme samples inhibited by EDTA and acetazolamide.

Novel single-round PCR and cloning of full-length envelope genes of HIV-1 may yield new insight into biomolecular antibacterial drug development

Nested or semi-nested polymerase chain reaction (PCR) with a ‘hot start’ is the preferred amplification method for full-length, in-frame envelope genes (gp160) of the human immunodeficiency virus type 1 (HIV-1). This generally follows an extensive screening process. This paper describes an effective single-round PCR method and cloning process for HIV-1 gp160 from clinical samples, and cell and tissue cultures developed during the early stages of construction of a molecular HIV-1 vaccine. The amplification method and cloning process are adaptable to full-length HIV-1, HIV-2, and other viral production processes. Also described within, is one solution to the most-often extensive screening process for inserts containing full-length, in-frame gp160. Of note, was a perceived toxicity of gp160 to bacteria during the culturing and the scaling-up process that created the extensive screening process. The toxicity association was not found with the individual gp160 genes, the gp120 or the gp41 gene, with other viral regions similar or larger in molecular weight to gp160, or with other non-gp160 full-length genes of HIV-1 such as pol and gag genes. The HIV-1 gp160 toxicity issue may provide insight towards the development of the next generation of novel biomolecular drugs against bacterial infections.

Bilateral rearfoot asymmetry and anterior knee pain syndrome.

Single-session observational study. To examine the magnitude and extent of asymmetry between right and left rearfoot angles in individuals who are asymptomatic versus symptomatic for anterior knee pain. Asymmetry in lower limb measures has been linked to the occurrence of knee pathologies, yet the practice of deriving unilateral rather than bilateral data and thereafter averaging the findings may play a role in obscuring the true nature of the rearfoot angle-knee pain relationship. A convenience sample of participants was recruited from the local university and business communities and a university-affiliated physiotherapy clinic. Eighty-on young adult males and females volunteered to participate in this study. Following an extensive screening process, including mandatory exclusion for a previous history of lower limb dysfunction or injury, data were collected from 75 individuals classified as asymptomatic (n = 50), unilaterally symptomatic (n = 11), or bilaterally symptomatic (n = 14) for anterior knee pain. Right and left rearfoot angles were goniometrically measured under static, weight-bearing conditions. No significant differences in mean right and left rearfoot angles by group or limb were observed. However, these mean values did not always reflect the true variation of data within the sample. Fifty-six percent of the individuals studied demonstrated a minimum of 4 degrees bilateral rearfoot angle difference, while for 20% of the sample this difference exceeded 7 degrees. Only a we yet statistically significant correlation existed between right and left rearfoot angles (r = 0.31, P < 0.01). Rearfoot angles in weight bearing are not bilaterally symmetric, and the magnitude and direction of the observed asymmetry does not appear to be indicative of whether an individual is asymptomatic or symptomatic for anterior knee pain.