1741. Antibiotic Prescribing Practices in Pediatric Acute Respiratory Illnesses in Northern Vietnam

Background

Antimicrobial resistance (AMR) is a global challenge and influenced by several factors including antibiotic overprescribing. Antibiotics are frequently prescribed in Vietnam, especially in pediatric acute respiratory illnesses (ARIs). Understanding prescribing practices for pediatric ARIs is important to help identify areas for improved practices to prevent overprescribing and AMR.

Methods

We performed a retrospective review of pediatric patients aged 0-15 years with an ARI diagnosis based on ICD-10 codes from January 1-December 31, 2019 in 112 primary care centers in Northern Vietnam. Variables collected included age, sex, district, antibiotic prescribed, World Health Organization access, watch, reserve classification (WHO AWaRe), symptomatic agents prescribed, and signs and symptoms. Data was analyzed using descriptive statistical analysis.

Results

A total of 35,679 encounters were reviewed. Of all encounters, 34,018 (95.3%) received antibiotics, and 1,650 (4.9%) of these received >1 antibiotic (Table 1). According to WHO AWaRe classification, 19.3% of children 0 to < 5 years received a watch antibiotic compared to 10.4% in those 5 to15 years. The most frequent diagnosis was acute pharyngitis (21,270 encounters, 59.6%) and 20,496 (96.4%) of those encounters received antibiotics. Common signs and symptoms reported included cough (76.3%), fever (40.9%), and erythematous pharynx (33.1%). Though acute pharyngitis was the most common diagnosis, only 168 (0.5%) and 59 (0.2%) of encounters described lymphadenopathy and exudate, respectively.

Conclusion

Antibiotics are frequently prescribed for pediatric ARIs in Northern Vietnam. Most antibiotics prescribed were WHO AWaRe access antibiotics; however, 14% were watch antibiotics or not recommended. Though acute pharyngitis was the most common diagnosis, only a few of the encounters reported signs or symptoms that would be more suggestive of acute bacterial pharyngitis warranting antibiotics. Further investigation of the appropriateness of antibiotic prescriptions are needed to help identify targeted areas of improvement in prescribing practices and help decrease the burden of AMR.

Disclosures

Daniel Olson, MD, Pfizer: Grant/Research Support|Roche: Grant/Research Support.

Community knowledge and practices regarding antibiotic use in rural Mozambique: where is the starting point for prevention of antibiotic resistance?

BACKGROUND

Antibiotic misuse and other types of unnecessary use of antibiotics can contribute to accelerate the process of antibiotic resistance, which is considered a global concern, mostly affecting low-and middle-income countries (LMICs). In Mozambique there is limited evidence on community knowledge and practices regarding antibiotics and antibiotic resistance. As part of the ABACUS project, this paper describes knowledge and practices of antibiotic use among the general population in the semi-rural district of Manhiça to inform evidence-based communication intervention strategies for safer antibiotic use.

METHODS

The study was conducted in Manhiça, a semi-rural district of Southern Mozambique. Sixteen in-depth interviews and four focus group discussions (FGDs) were conducted with community members to explore lay knowledge and practices regarding antibiotics and awareness of antibiotic resistance. The qualitative data was analysed using a combination of content and thematic analysis. The SRQR guidelines for reporting qualitative studies was performed.

RESULTS

Although participants did not hold any consistent knowledge of antibiotics, their visual recognition of amoxicillin (distinct red yellow capsule) was acceptable, but less so for different types and brands of antibiotics. The majority of participants were aware of the term 'antibiotic', yet the definition they gave was rarely backed by biomedical knowledge. Participants associated antibiotics with certain colours, shapes and health conditions. Participants reported common habits that may contribute to resistance: not buying the full course, self-medication, sharing medicines and interruption of treatment. Most had never heard of the term 'antibiotic resistance' but were familiar with the phenomenon. They often understood the term 'resistance' as treatment failure and likened 'resistance' to non-compliance, ineffective medication, disease resistance or to an inability of the physical body to respond to it.

CONCLUSION

There is a broad understanding of the importance of medication compliance but not specifically of antibiotic resistance. In addition, there is a recognized gap between knowledge of responsible drug compliance and actual behaviour. Future qualitative research is required to further explore what determines this behaviour. The existing ability to visually identify amoxicillin by its distinct red and yellow appearance is informative for future awareness and behavioural change campaigns that may incorporate visual aids of antibiotics.

Improving topical non-melanoma skin cancer treatment: In vitro efficacy of a novel guanosine-analog phosphonate

Actinic keratosis, a frequent carcinoma in situ of non-melanoma skin cancer (NMSC), can transform into life-threatening cutaneous squamous cell carcinoma. Current treatment is limited due to low complete clearance rates and asks for novel therapeutic concepts; the novel purine nucleotide analogue OxBu may be an option. In order to enhance skin penetration, solid lipid nanoparticles (SLN, 136-156 nm) were produced with an OxBu entrapment efficiency of 96.5 ± 0.1%. For improved preclinical evaluation, we combined tissue engineering with clinically used keratin-18 quantification. Three doses of 10(-3) mol/l OxBu, dissolved in phosphate-buffered saline as well as loaded to SLN, were effective on reconstructed NMSC. Tumour response and apoptosis induction were evaluated by an increase in caspase-cleaved fragment of keratin-18, caspase-7 activation as well as by reduced expression of matrix metallopeptidase-2 and Ki-67. OxBu efficacy was superior to equimolar 5-fluorouracil solution, and thus the drug should be subjected to the next step in preclinical evaluation.

Antitumor activity of cell-permeable RUNX3 protein in gastric cancer cells

PURPOSE

Gastric cancer is a leading cause of cancer death worldwide. Limited therapeutic options highlight the need to understand the molecular changes responsible for the disease and to develop therapies based on this understanding. The goal of this study was to develop cell-permeable (CP-) forms of the RUNT-related transcription factor 3, RUNX3-a candidate tumor suppressor implicated in gastric and other epithelial cancers-to study the therapeutic potential of RUNX3 in the treatment of gastric cancer.

EXPERIMENTAL DESIGN

We developed novel macromolecule transduction domains (MTD) which were tested for the ability to promote protein uptake by mammalian cells and tissues and used to deliver of biologically active RUNX3 into human gastric cancer cells. The therapeutic potential CP-RUNX3 was tested in the NCI-N87 human tumor xenograft animal model.

RESULTS

RUNX3 fusion proteins, HM(57)R and HM(85)R, containing hydrophobic MTDs enter gastric cancer cells and suppress cell phenotypes (e.g., cell-cycle progression, wounded monolayer healing, and survival) and induce changes in biomarker expression (e.g., p21(Waf1) and VEGF) consistent with previously described effects of RUNX3 on TGF-β signaling. CP-RUNX3 also suppressed the growth of subcutaneous human gastric tumor xenografts. The therapeutic response was comparable with studies augmenting RUNX3 gene expression in tumor cell lines; however, the protein was most active when administered locally, rather than systemically (i.e., intravenously).

CONCLUSIONS

These results provide further evidence that RUNX3 can function as a tumor suppressor and suggest that practical methods to augment RUNX3 function could be useful in treating of some types of gastric cancer.

Collinear guided wave to leaky wave acoustooptic interactions in proton-exchanged LiNbO(3) waveguides

The results of a detailed theoretical study on collinear guided wave to leaky wave acoustooptic (AO) interactions in proton-exchanged LiNbO(3) (PE:LiNbO(3)) planar waveguides are presented. The guided-to-leaky mode conversion for an input optical beam at the wavelength of 632.8 nm by the induced diffraction grating from a collinear surface acoustic wave (SAW) is analyzed using a generalized multimode formulation of the coupled mode theory. Mode conversion efficiency and AO bandwidth have been calculated as functions of acoustic frequency, interaction length, guiding layer thickness, and acoustic drive power density for three cuts of the LiNbO(3) substrate. High performance configurations that are desirable for application to demultiplexing and switching in optical communication systems are identified, and the corresponding channel capacity and frequency resolution are determined. For example, it was shown that the X-cut configuration features the highest mode conversion efficiency. However, a relatively small AO bandwidth is associated with this configuration. Both high mode conversion efficiency and large AO bandwidth can be accomplished at the guiding layer thickness of 1.0 microm. A TM(o)-->TE(nu) mode conversion efficiency as high as 42% together with an AO bandwidth of approximately 70 MHz can be achieved in the Z-cut waveguide at the guiding layer thickness of 1.0 microm, acoustic drive power density of 50 mW/mm, interaction length of 40 mm, and acoustic frequency of 460 MHz. The corresponding channel capacity and frequency resolution are 745 and 0.09 MHz, respectively. Measured mode conversion efficiencies as high as 90 and 78% obtained at the acoustic frequencies of 107 and 367 MHz using the X-cut substrate and the Y-propagation SAW have verified the theoretical prediction on the mode conversion efficiencies.

Epithelial cell polarity affects susceptibility to Pseudomonas aeruginosa invasion and cytotoxicity

Intact tissues are relatively resistant to Pseudomonas aeruginosa-induced disease, and injury predisposes tissue to infection. Intact epithelia contain polarized cells that have distinct apical and basolateral membranes with unique lipids and proteins. In this study, the role of cell polarity in epithelial cell susceptibility to P. aeruginosa virulence mechanisms was tested. Madin-Darby canine kidney (MDCK) cells, human corneal epithelial cells, and primary cultures of two different types of airway epithelial cells were grown on Transwell filters or in plastic tissue culture wells. P. aeruginosa invasion of cells was quantified by gentamicin survival assays with two isolates that invade epithelial cells (6294 and PAO1). Cytotoxic activity was assessed by trypan blue exclusion assays with two cytotoxic strains (6206 and PA103). Basolateral surfaces of cells were exposed by one of two methods: EGTA pretreatment of epithelial cells or growth of cells in low-calcium medium. Both methods of exposing basolateral membranes increased epithelial cell susceptibility to P. aeruginosa invasion and cytotoxicity. Migrating cells were also found to be more susceptible to P. aeruginosa invasion than confluent monolayers that had established membrane polarity. Monolayers of MDCK cells that had been selected for resistance to killing by concanavalin A were resistant to both cytotoxicity and invasion by P. aeruginosa because they were more efficiently polarized for their susceptibility to P. aeruginosa virulence factors than regular MDCK cells and not because they were defective in glycosylation. These results suggest that there are factors on the basolateral surfaces of epithelial cells that promote interaction with P. aeruginosa or that there are inhibitory factors on the apical cell surface. Thus, cell polarity of intact epithelia is likely to contribute to defense against P. aeruginosa infection.

Temperature dependence of optical properties for amorphous silicon at wavelengths of 632.8 and 752 nm

The temperature dependence of the optical properties for amorphous silicon is studied at wavelengths of 632.8 and 752 nm. Both the refractive index and extinction coefficient increase linearly with temperature for 752 nm, while the refractive index decreases and the extinction coefficient increases for 632.8 nm. The rate of increase of the extinction coefficient at 632.8 nm is twice as much as that for 752 nm.

Explosion of a liquid film in contact with a pulse-heated solid surface detected by the probe-beam deflection method

The threshold for explosive vaporization of a liquid layer on an opaque solid surface heated by an ultraviolet excimer pulsed laser is studied by a photoacoustic probe-beam deflection method. The probe beam traverses the liquid in the vicinity of the laser-heated liquid-solid interface. Below the explosion threshold, photoacoustic generation in the solid occurs only through a thermoelastic mechanism, which results mainly in shear waves that do not couple well into the liquid. Above the explosion threshold, photoacoustic pulses in the solid are also produced by explosive recoil, hence producing longitudinal pulses in the solid that couple well into the liquid after reflections. By setting the probe-beam refraction to detect longitudinal pulse echoes coupled back into the liquid, a sensitive detection of the explosive threshold can be established.

A simple technique for removing plant polysaccharide contaminants from DNA

A survey of the inhibitory effects of various plant polysaccharides on DNA restrictions (HindIII and EcoRI) revealed that neutral polysaccharides (arabino-galactan, dextran, gum guar, gum locust bean, beta-glucan, inulin, laminaran, mannan and starch) were not very inhibitory. In contrast, acidic polysaccharides (carrageenan, dextran sulfate, gum ghatti, gum karaya, pectin and xylan) were very inhibitory, even at low concentrations. The Elutip-d (RPC-5 type resin) was evaluated for removal of the inhibitory polysaccharides. Used alone or in combination with a phenol/chloroform wash, it proved effective in removing the polysaccharide so that HindIII digestion was possible, except in the cases of carrageenan and dextran sulfate. In addition, the genomic DNA extracts from live oak (Quercus virginiana) and magnolia (Magnolia grandiflora) were sufficiently purified so that the DNAs could be restricted with both EcoRI and HindIII.

Regulation of erythropoiesis in diabetes mellitus

The regulation of erythropoiesis in 40 subjects with diabetes mellitus was investigated to test the hypothesis that increased blood concentrations of glycosylated hemoglobin would produce a reduced p50 and a compensatory increase in erythropoietin. Little evidence to support this hypothesis was observed. However, diabetes did produce complex changes in hemoglobin-oxygen releasing capacity which were compensated for in the expected way, i.e. oxygen releasing capacity showed an inverse correlation with erythropoietin. We conclude that the effects of diabetes on erythropoiesis are minor and probably have no pathological significance in most patients suffering from this disease.