Selection of Aptamers Specific for Adipose Tissue

Obesity has reached epidemic proportions, affecting more than one tenth of the world's population. As such, adipose tissue is being increasingly recognized as an important therapeutic target for obesity and related metabolic disorders. While many potential targets of adipose tissue have been established and drugs developed, very few of those drugs specifically target adipose tissue without affecting other tissue. This results from a limited knowledge of both cell-surface markers and physicochemical traits specific to adipocytes that might otherwise be exploited by circulating drugs.Here we report the use of cell-SELEX technology to select two aptamers that can specifically recognize mature adipocytes: adipo-1 and adipo-8. Adipo-8 shows high affinity for differentiated, mature 3T3-L1 adipocytes with a K(d) value of 17.8±5.1 nM. The binding was sustained upon incubation at 37°C and insulin stimulation, but was lost upon trypsin treatment. The binding ability was also verified on frozen tissue slides with low background fluorescence and isolated adipocytes.Aptamer adipo-8 selected from a random library appears to bind to mature differentiated adipocytes specifically. This aptamer holds great promise as a molecular recognition tool for adipocyte biomarker discovery or for targeted delivery of molecules to adipocytes

Supporting global antimicrobial stewardship : antibiotic prophylaxis for the prevention of surgical site infection in low and middle income countries (LMICs): a scoping review and meta-analysis

Background: The Scottish Antimicrobial Prescribing Group (SAPG) is supporting two hospitals in Ghana to develop antimicrobial stewardship. Early intelligence gathering suggested that surgical prophylaxis was suboptimal. We reviewed the evidence for use of surgical prophylaxis to prevent surgical site infections (SSI) in low and middle-income countries (LMICs) to inform this work. Methods: MEDLINE, Embase, Cochrane, CINHAL and Google Scholar were searched from inception to 17 February, 2020 for trials, audits, guidelines and systematic reviews in English. Grey literature, websites and reference lists of included studies were searched. Randomised clinical trials reporting incidence of SSI following Caesarian section were included in two meta-analyses. Narrative analysis of studies that explored behaviours and attitudes was conducted. Results: This review included 51 studies related to SSI and timing of antibiotic prophylaxis in LMICs. Incidence of SSIs is higher in LMICs, infection surveillance data is poor and there is a lack of local guidelines for antibiotic prophylaxis. Education to improve appropriate antibiotic prophylaxis is associated with reduction of SSI in LMICs.The random effects pooled mean risk ratio of SSI in Caesarian section was 0.77 (95% CI: 0.51 to 1.17) for pre-incision versus post-incision prophylaxis and 0.89 (95% CI: 0.55 to 1.14) for short versus long duration, Reduction in cost and nurse time was reported in shorter duration SAP. Conclusion: There is scope for improvement but interventions must include local context and address strongly held beliefs. Establishment of local multidisciplinary teams will promote ownership and sustainability of change

DNA Aptamers as Molecular Probes for Colorectal Cancer Study

Understanding the molecular features of specific tumors can increase our knowledge about the mechanism(s) underlying disease development and progression. This is particularly significant for colorectal cancer, which is a heterogeneous complex of diseases developed in a sequential manner through a multistep carcinogenic process. As such, it is likely that tumors with similar characteristics might originate in the same manner and have a similar molecular behavior. Therefore, specific mapping of the molecular features can be potentially useful for both tumor classification and the development of appropriate therapeutic regimens. However, this can only be accomplished by developing high-affinity molecular probes with the ability to recognize specific markers associated with different tumors. Aptamers can most easily meet this challenge based on their target diversity, flexible manipulation and ease of development.Using a method known as cell-based Systematic Evolution of Ligands by Exponential enrichment (cell-SELEX) and colorectal cancer cultured cell lines DLD-1 and HCT 116, we selected a panel of target-specific aptamers. Binding studies by flow cytometry and confocal microscopy showed that these aptamers have high affinity and selectivity. Our data further show that these aptamers neither recognize normal colon cells (cultured and fresh), nor do they recognize most other cancer cell lines tested.The selected aptamers can identify specific biomarkers associated with colorectal cancers. We believe that these probes could be further developed for early disease detection, as well as prognostic markers, of colorectal cancers

Supporting antimicrobial stewardship in Ghana:evaluation of the impact of training on knowledge and attitudes of healthcare professionals in two hospitals

Background A Commonwealth Partnership for Antimicrobial Stewardship was created between the Scottish Antimicrobial Prescribing Group (SAPG), Ghana Police Hospital and Keta Municipal Hospital. During a scoping visit, requirements for implementing antimicrobial stewardship (AMS), areas for improvement and training needs were identified. Methods A multidisciplinary team from SAPG and health psychologists from The Change Exchange developed and delivered multi-professional evidence-based teaching incorporating behavioural science, supported by partner pharmacists in each hospital. Four sessions were delivered over 2 days to 60 participants across both sites. Before and after the sessions, participants were asked to complete a knowledge quiz and a behaviours survey. Results were analysed using t-tests. Results Comparison of the participants’ pre- and post-test quiz scores (Keta Municipal Hospital 9.4 and 10.9, Ghana Police Hospital 9.2 and 11.1, respectively) demonstrated statistically significant improvement in knowledge of antimicrobial resistance and appropriate use of antibiotics. Comparison of survey responses before and after the education sessions indicated that the education had a positive impact on participants’ attitudes towards the issue of antimicrobial resistance, their role in AMS and confidence in using the Ghana Standard Treatment Guidelines. Participants were also more likely to question colleagues about compliance with guidelines. Forty-eight participants (80%) completed a training evaluation and all responded positively. Conclusions The education sessions appeared to be successful in improving knowledge and behaviours of hospital staff. Cascade of an abbreviated version of the training by partner pharmacists and AMS teams in Ghana will ensure that all staff have the opportunity to develop skills and knowledge to support AMS

Detailed sequences of aptamers used in the binding assay (primers are blue-colored).

<p>Detailed sequences of aptamers used in the binding assay (primers are blue-colored).</p