A new chromatographic response function with automatically adapting weight factor for automated method development.

A critical factor for automated method development in chromatography is the maximization or minimization of an objective function describing the quality (and speed) of the separation. In chromatography, this function is commonly referred to as a chromatographic response function (CRF). Many CRFs have previously been introduced, but many have unfavourable properties such as featuring multiple optima, insufficient discriminatory power, and a too strong dependence on the weight factors needed to balance resolution and time penalty components. To overcome these problems, the present study introduces a new type of CRF wherein the relative weight of the time penalty term is a self-adaptive function of the separation quality. The ability to unambiguously identify the optimal gradient settings of this newly proposed CRF is compared to that of some of the most frequently used CRFs in a study covering 100 randomly composed in silico samples. Doing so, the new CRF is found to flawlessly lead to the correct solution (=linear gradient parameters providing the highest resolution in the shortest potential time) in 100 % of the cases, while the most frequently used literature CRFs were off-target for about 50 to 60 % of the samples, even when considering the availability of spectral peak shape data. Some slight alterations to the proposed CRF are introduced and discussed as well.

Generating prophylactic immunity against arboviruses in vertebrates and invertebrates.

The World Health Organization recently declared a global initiative to control arboviral diseases. These are mainly caused by pathogenic flaviviruses (such as dengue, yellow fever and Zika viruses) and alphaviruses (such as chikungunya and Venezuelan equine encephalitis viruses). Vaccines represent key interventions for these viruses, with licensed human and/or veterinary vaccines being available for several members of both genera. However, a hurdle for the licensing of new vaccines is the epidemic nature of many arboviruses, which presents logistical challenges for phase III efficacy trials. Furthermore, our ability to predict or measure the post-vaccination immune responses that are sufficient for subclinical outcomes post-infection is limited. Given that arboviruses are also subject to control by the immune system of their insect vectors, several approaches are now emerging that aim to augment antiviral immunity in mosquitoes, including Wolbachia infection, transgenic mosquitoes, insect-specific viruses and paratransgenesis. In this Review, we discuss recent advances, current challenges and future prospects in exploiting both vertebrate and invertebrate immune systems for the control of flaviviral and alphaviral diseases.

Periventricular cyst as a complication of ventriculoperitoneal shunting in the context of intracranial haemorrhage: a case report and review of the literature.

Spontaneous intraventricular haemorrhage with hydrocephalus frequently requires neurosurgical intervention, including ventriculoperitoneal shunting. We describe a periventricular cyst following the placement of a ventriculoperitoneal shunt in a 67-year-old female patient. The patient was admitted for rehabilitation after a spontaneous left basal ganglia and diffuse intraventricular haemorrhage with hydrocephalus. Initial management included an extraventricular drain, followed by a ventriculoperitoneal shunt. On Day 5 of rehabilitation, the patient was urgently reviewed for reduced level of consciousness. A cerebrospinal fluid cyst was identified around the shunt catheter, with subacute haemorrhage within the cyst. The patient underwent a successful shunt revision, with rapid improvement in consciousness and resolution of the cyst. This case highlights the importance of pericatheter cyst as a differential diagnosis in patients with altered neurological status following ventriculoperitoneal shunting. Early detection and surgical revision can lead to rapid resolution of symptoms and a favourable prognosis.

Towards pharmacogenomics-guided tuberculosis (TB) therapy: N-acetyltransferase-2 genotypes among TB-infected Kenyans of mixed ethnicity.

BACKGROUND: Though persons of African descent have one of the widest genetic variability, genetic polymorphisms of drug-metabolising enzymes such as N-Acetyltransferase-2 (NAT2) are understudied. This study aimed to identify prevalent NAT2 single nucleotide polymorphisms (SNPs) and infer their potential effects on enzyme function among Kenyan volunteers with tuberculosis (TB) infection. Genotypic distribution at each SNP and non-random association of alleles were evaluated by testing for Hardy-Weinberg Equilibrium (HWE) and Linkage Disequilibrium (LD). METHODS: We isolated genomic DNA from cryopreserved Peripheral Blood Mononuclear Cells of 79 volunteers. We amplified the protein-coding region of the NAT2 gene by polymerase chain reaction (PCR) and sequenced PCR products using the Sanger sequencing method. Sequencing reads were mapped and aligned to the NAT2 reference using the Geneious software (Auckland, New Zealand). Statistical analyses were performed using RStudio version 4.3.2 (2023.09.1 + 494). RESULTS: The most frequent haplotype was the wild type NAT2*4 (37%). Five genetic variants: 282C > T (NAT2*13), 341 T > C (NAT2*5), 803A > G (NAT2*12), 590G > A (NAT2*6) and 481C > T (NAT2*11) were observed with allele frequencies of 29%, 18%, 6%, 6%, and 4% respectively. According to the bimodal distribution of acetylation activity, the predicted phenotype was 76% rapid (mainly consisting of the wildtype NAT2*4 and the NAT2*13A variant). A higher proportion of rapid acetylators were female, 72% vs 28% male (p = 0.022, odds ratio [OR] 3.48, 95% confidence interval [CI] 1.21 to 10.48). All variants were in HWE. NAT2 341 T > C was in strong complete LD with the 590G > A variant (D' = 1.0, r2 = - 0.39) but not complete LD with the 282C > T variant (D' = 0.94, r2 = - 0.54). CONCLUSION: The rapid acetylation haplotypes predominated. Despite the LD observed, none of the SNPs could be termed tag SNP. This study adds to the genetic characterisation data of African populations at NAT2, which may be useful for developing relevant pharmacogenomic tools for TB therapy. To support optimised, pharmacogenomics-guided TB therapy, we recommend genotype-phenotype studies, including studies designed to explore gender-associated differences.

Detailed analysis of the effective and intra-particle diffusion coefficient of proteins at elevated pressure in columns packed with wide-pore core-shell particles.

To determine the efficiency that can be obtained in a packed-bed liquid-chromatography column for a particular analyte, a correct determination of the molecular and effective diffusion coefficients (Dm and Deff) of the analyte is required. The latter is usually obtained via peak parking experiments wherein the flow is stopped. As a result, the column pressure rapidly dissipates and the measurement is essentially conducted at ambient pressure. This is problematic for analytes whose retention depends on pressure, such as proteins and potentially other large (dipolar) molecules. In that case, a conventional peak parking experiment is expected to lead to large errors in Deff. To obtain a better estimate ofDeff, the present study reports on the use of a set-up enabling peak parking measurements under pressurized conditions. This approach allowed us to report, for the first time, Deff for proteins at elevated pressure under retained conditions. First, Deff was determined at a (average) pressure of about 105 bar for a set of proteins with varying size, namely: bradykinin, insulin, lysozyme, ß-lactoglobulin, and carbonic anhydrase in a column packed with 400 Å core-shell particles. The obtained data were then compared to those of several small analytes: acetophenone, propiophenone, benzophenone, valerophenone, and hexanophenone. A clear trend between Deff and analyte size was observed. The set-up was then used to determine Deff of bradykinin and lysozyme at variable (average) pressures ranging from 28 bar to 430 bar. These experiments showed a decrease in intra-particle and surface diffusion with pressure, which was larger for lysozyme than bradykinin. The data show that pressurized peak parking experiments are vital to correctly determine Deff when the analyte retention varies significantly with pressure.

Polyhydroxyalkanoates production in purple phototrophic bacteria ponds: A breakthrough in outdoor pilot-scale operation.

The versatile capacity of purple phototrophic bacteria (PPB) for producing valuable bioproducts has gathered renewed interest in the field of resource recovery and waste valorisation. However, greater knowledge regarding the viability of applying PPB technologies in outdoor, large-scale systems is required. This study assessed, for the first time, the upscaling of the phototrophic polyhydroxyalkanoate (PHA) production technology in a pilot-scale system operated in outdoor conditions. An integrated system composed of two up-flow anaerobic sludge blanket (UASB) reactors (for fermentation of wastewater with molasses), and two high-rate algal ponds retrofitted into PPB ponds, was operated in a wastewater treatment plant under outdoor conditions. UASB's adaptation to the outdoor temperatures involved testing different operational settings, namely hydraulic retention times (HRT) of 48 and 72 h, and molasses fermentation in one or two UASBs. Results have shown that the fermentation of molasses in both UASBs with an increased HRT of 72 h was able to ensure a suitable operation during colder conditions, achieving 3.83 ± 0.63 g CODFermentative Products/L, compared to the 3.73 ± 0.85 g CODFermentative Products/L achieved during warmer conditions (molasses fermentation in one UASB; HRT 48 h). Furthermore, the PPB ponds were operated under a light-feast/dark-aerated-famine strategy and fed with the fermented wastewater and molasses from the two UASBs. The best PHA production was obtained during the summer of 2018 and spring of 2019, attaining 34.7 % gPHA/gVSS with a productivity of 0.11 gPHA L-1 day-1 and 36 % gPHA/gVSS with a productivity of 0.14 gPHA L-1 day-1, respectively. Overall, this study showcases the first translation of phototrophic PHA production technology from an artificially illuminated laboratory scale system into a naturally illuminated, outdoor, pilot-scale system. It also addresses relevant process integration aspects with UASBs for pre-fermenting wastewater with molasses, providing a novel operational strategy to achieve photosynthetic PHA production in outdoor full-scale systems.

Methenamine for urinary tract infection prophylaxis: A systematic review.

Urinary tract infections (UTIs) commonly affect many patient populations. Recurrent UTIs (rUTIs) can be particularly problematic and lead to potential hospitalizations, multiple antibiotic courses, and have a potential negative impact on quality of life. To prevent UTIs, antibiotics are frequently used for prophylaxis; however, antibiotic prophylaxis has notable untoward consequences including but not limited to potential adverse effects and development of antibiotic resistance. Methenamine, an antiseptic agent initially available in 1967, has re-emerged as a potential option for UTI prophylaxis in various populations, including older adults and renal transplant recipients. The objective of this systematic review was to evaluate the clinical effectiveness and safety of methenamine for UTI prophylaxis. A systematic review following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidance was performed. A PubMed, Embase, and Cochrane library search was conducted to identify relevant English-language studies evaluating methenamine for UTI prophylaxis including randomized controlled trials, case-control studies, and meta-analyses through June 2023. Articles were excluded if the studies did not primarily describe or evaluate methenamine for UTI prophylaxis, were commentaries/viewpoints articles, point prevalence studies, review articles, studies that evaluated methenamine used with another agent, and any duplicate publications from searched databases. A total of 11 articles were identified for inclusion. This systematic review suggests methenamine generally appears to be an effective and well-tolerated antibiotic-sparing option for UTI prophylaxis. Furthermore, the pharmacology, dosage and formulation, warnings, precautions, and safety considerations of methenamine that provide potential clinical considerations regarding its use for UTI prophylaxis are described. Further studies are needed to evaluate the clinical utility of methenamine for UTI prophylaxis.

Ammonia impact on the selection of a phototrophic - chemotrophic consortium for polyhydroxyalkanoates production under light-feast / dark-aerated-famine conditions.

Phototrophic polyhydroxyalkanoate (PHA) production is an emerging technology for recovering carbon and nutrients from diverse wastewater streams. However, reliable selection methods for the enrichment of PHA accumulating purple phototrophic bacteria (PPB) in phototrophic mixed cultures (PMC) are needed. This research evaluates the impact of ammonia on the selection of a PHA accumulating phototrophic-chemotrophic consortium, towards the enrichment of PHA accumulating PPB. The culture was operated under light-feast/dark-aerated-famine and winter simulated-outdoor conditions (13.2 ± 0.9 °C, transient light, 143.5 W/m2), using real fermented domestic wastewater with molasses as feedstock. Three ammonia supply strategies were assessed: 1) ammonia available only in the light phase, 2) ammonia always present and 3) ammonia available only during the dark-aerated-famine phase. Results showed that the PMC selected under 1) ammonia only in the light and 3) dark-famine ammonia conditions, presented the lowest PHA accumulation capacity during the light period (11.1 % g PHA/g VSS and 10.4 % g PHA/g VSS, respectively). In case 1), the absence of ammonia during the dark-aerated-famine phase did not promote the selection of PHA storing PPB, whereas in case 3) the absence of ammonia during the light period favoured cyanobacteria growth as well as purple sulphur bacteria with increased non-PHA inclusions, resulting in an overall decrease of phototrophic PHA accumulation capacity. The best PHA accumulation performance was obtained with selection under permanent presence of ammonia (case 2), which attained a PHA content of 21.6 % g PHA/g VSS (10.2 Cmmol PHA/L), at a production rate of 0.57 g PHA/L·day, during the light period in the selection reactor. Results in case 2 also showed that feedstock composition impacts the PMC performance, with feedstocks richer in more reduced volatile fatty acids (butyric and valeric acids) decreasing phototrophic performance and leading to acids entering the dark-aerated phase. Nevertheless, the presence of organic carbon in the aerated phase was not detrimental to the system. In fact, it led to the establishment of a phototrophic-chemotrophic consortium that could photosynthetically accumulate a PHA content of 13.2 % g PHA/g VSS (6.7 Cmmol PHA/L) at a production rate of 0.20 g PHA/L·day in the light phase, and was able to further increase that storage up to 18.5 % g PHA/g VSS (11.0 Cmmol PHA/L) at a production rate of 1.35 g PHA/L·day in the dark-aerated period. Furthermore, the light-feast/dark-aerated-famine operation was able to maintain the performance of the selection reactor under winter conditions, unlike non-aerated PMC systems operated under summer conditions, suggesting that night-time aeration coupled with the constant presence of ammonia can contribute to overcoming the seasonal constraints of outdoor operation of PMCs for PHA production.

Capacitively coupled contactless conductivity detection to account for system-induced gradient deformation in liquid chromatography.

The time required for method development in gradient-elution liquid chromatography (LC) may be reduced by using an empirical modelling approach to describe and predict analyte retention and peak width. However, prediction accuracy is impaired by system-induced gradient deformation, which can be especially prominent for steep gradients. As the deformation is unique to each LC instrument, it needs to be corrected for if retention modelling for optimization and method transfer is to become generally applicable. Such a correction requires knowledge of the actual gradient profile. The latter has been measured using capacitively coupled "contactless" conductivity detection (C4D), featuring a low detection volume (approximately 0.05 µL) and compatibility with very high pressures (80 MPa or more). Several different solvent gradients, from water to acetonitrile, water to methanol, and acetonitrile to tetrahydrofuran, could be measured directly without the addition of a tracer component to the mobile phase, exemplifying the universal nature of the approach. Gradient profiles were found to be unique for each solvent combination, flowrate, and gradient duration. The profiles could be described by convoluting the programmed gradient with a weighted sum of two distribution functions. Knowledge of the exact profiles was used to improve the inter-system transferability of retention models for toluene, anthracene, phenol, emodin, sudan-I and several polystyrene standards.

Pharmacist prescribed hormonal contraceptives in New York State: Is there a need and an interest?

BACKGROUND: Hormonal contraceptives are a popular option for pregnancy prevention and other indications and require a prescription. Since 2013, 24 states have given pharmacists legal authority to initiate self-administered hormonal contraceptives, allowing for direct pharmacy access (DPA). New York State (NYS) did not allow for DPA of any hormonal contraceptives during the survey period, but passed a bill in 2023 allowing pharmacists to dispense hormonal contraceptives in accordance with a nonpatient-specific order. OBJECTIVES: This study aimed to characterize the experiences, perceptions, and knowledge of access to and DPA to hormonal contraceptives. METHODS: A survey was developed to gather responses to demographic- and opinion-related questions and administered online using the Pollfish survey platform. Participants were women between the ages of 16 and 44 years who lived in NYS. To ensure geographic representation, at least one response was gathered from each of the 27 NYS congressional districts. Chi-square tests were used to assess differences in hormonal contraceptive use by patient demographics. RESULTS: Most of the 500 respondents reported past (76.2%) or current/planned (76.8%) use of hormonal contraceptives. Older age (P = 0.033) and higher income (P = 0.0016) were associated with significantly greater rates of use. The most common challenges when visiting a provider for birth control included needing to schedule an appointment and wait times at the provider. Almost three-quarters of respondents (72.6%) were not aware that pharmacists could initiate contraceptives in other states, and 74.2% reported feeling comfortable with a pharmacist prescribing and dispensing hormonal contraceptives. CONCLUSION: Contraceptive initiation by pharmacists would be acceptable to most respondents, but there is room for increased acceptance based on patient education and experience. DPA to hormonal contraceptives may eliminate some of the barriers identified in this survey.

Age and CD4+ T cell counts are inversely associated with HIV drug resistance mutations in treatment naive female sex workers.

The increasing prevalence of human immunodeficiency virus (HIV) drug resistance mutations (HIVDRM) in untreated seropositive persons has consequences for future treatment options. This is extremely important in key populations such as female sex workers (FSWs), where the prevalence of pretreatment drug resistance (PDR) and associated risk factors are unknown. In this study, we analyzed PDR and associated risk factors in recently diagnosed and treatment-naive FSWs in Nairobi, Kenya. In this cross-sectional study, we used 64 HIV-seropositive plasma samples collected from FSWs between November 2020 and April 2021. To identify HIVDRM, the pol gene was amplified and genotyped using sanger sequencing. The effects of age, tropism, CD4+ T cell count, subtype, and location on HIVDRM counts were examined using Poisson regression. Overall, the prevalence of PDR was 35.9% (95% CI: 24.3-48.9), which was strongly influenced by K103N and M184V mutations, which confer resistance to non-nucleoside reverse transcriptase inhibitors (NNRTIs) and nucleoside reverse transcriptase inhibitors (NRTI), respectively. Subtype A1 was predominant followed by subtype D with a notable increase in inter-subtype recombinants. We found statistically significant evidence that age was inversely related to HIVDRM. A FSW who is 1 year older had 12% less HIVDRM (incidence rate ratios [IRR]: 0.88; 95% CI: 0.82-0.95; P < .001), after adjusting for CD4+ T cell count, subtype, location, and tropism. Similarly, an increase in CD4+ T cell count by 1 unit, was associated with 0.4% fewer HIVDRM (IRR: 0.996; 95% CI: 0.994-0.998; P = .001), while controlling for the other variables. HIV-1 tropism was not associated with HIVDRM counts. In conclusion, our findings show a high prevalence of NNRTIs. Lower CD4+ T cell counts and younger age were significant risk factors that influenced HIVDRM loads. This finding underscores the relevance of targeted interventions and the importance of continuing to focus on FSWs as a way of addressing the HIV epidemic.

Expanding known viral diversity in the healthy infant gut.

The gut microbiome is shaped through infancy and impacts the maturation of the immune system, thus protecting against chronic disease later in life. Phages, or viruses that infect bacteria, modulate bacterial growth by lysis and lysogeny, with the latter being especially prominent in the infant gut. Viral metagenomes (viromes) are difficult to analyse because they span uncharted viral diversity, lacking marker genes and standardized detection methods. Here we systematically resolved the viral diversity in faecal viromes from 647 1-year-olds belonging to Copenhagen Prospective Studies on Asthma in Childhood 2010, an unselected Danish cohort of healthy mother-child pairs. By assembly and curation we uncovered 10,000 viral species from 248 virus family-level clades (VFCs). Most (232 VFCs) were previously unknown, belonging to the Caudoviricetes viral class. Hosts were determined for 79% of phage using clustered regularly interspaced short palindromic repeat spacers within bacterial metagenomes from the same children. Typical Bacteroides-infecting crAssphages were outnumbered by undescribed phage families infecting Clostridiales and Bifidobacterium. Phage lifestyles were conserved at the viral family level, with 33 virulent and 118 temperate phage families. Virulent phages were more abundant, while temperate ones were more prevalent and diverse. Together, the viral families found in this study expand existing phage taxonomy and provide a resource aiding future infant gut virome research.

Update on imaging in Code Stroke.

"Code Stroke" is a multidisciplinary procedure designed to detect acute ischemic strokes and transfer patients for early reperfusion. Selecting these patients requires multimodal imaging with either CT or MRI. 1) Conventional studies without contrast material are obligatory to detect bleeding. Applying the ASPECTS scale, these studies can also identify and quantify areas of early infarction. 2) In candidates for mechanical thrombectomy, angiographic studies are necessary to identify stenoses and obstructions and to evaluate the collateral circulation. 3) Patients with known onset between 6 and 24h or with unknown onset require perfusion studies to distinguish between infracted tissue and recoverable ischemic tissue. Semi-automatic software facilitates diagnosis, but radiologists must interpret its output.

Evaluation of temperature excursions from USP <659> recommendations during mail transit.

BACKGROUND: Patients use mail delivery as a convenient alternative to acquiring medications in person. Federal laws require nonspecialty oral medications to be stored at controlled room temperature during distribution; however, no laws or regulations govern temperature requirements for medication transport among patients, which may expose medications to harmful temperature excursions. OBJECTIVE: The purpose of this study was to evaluate temperature excursions during mail transit based on the shipment method, carrier, and season. METHODS: This prospective study monitored temperature fluctuations during simulated mail transit between New Jersey, California, and Tennessee over winter (December 2019-February 2020) and summer (August-September 2020) time frames. Packages with data-logging thermometers were shipped to 3 U.S. destinations via 3 common mail carriers and 2 popular shipping methods. Three packages were mailed for each combination of season, carrier, and shipping method, representing 36 individual packages. The primary end point was percent of transit time out of range (OOR) based on the United States Pharmacopeia <659> recommended range, 68°F to 77°F. Additional end points include package transit durations and extreme temperatures. RESULTS: Evaluated packages spent an average of 68.3% of transit time OOR. In winter, 3-day and next business day packages spent similar time OOR (80.1% vs. 78%). In summer, 3-day packages spent more time OOR compared with next business day shipping (43.1% vs. 13.6%). Mean transit time was statistically significantly longer for 3-day packages (406.6 hours vs. 303.1 hours; P < 0.0001). Mean winter transit time was statistically significantly longer than summer (475.7 hours vs. 233.9 hours; P < 0.001) regardless of the shipping method. The minimum and maximum temperatures recorded were 5.1°F and 102.3°F, respectively. CONCLUSION: Package temperatures were outside of the recommended range for most of the transit time regardless of the shipping method, carrier, or season.

Insecticide resistance compromises the control of Aedes aegypti in Bangladesh.

BACKGROUND: With no effective drugs or widely available vaccines, dengue control in Bangladesh is dependent on targeting the primary vector Aedes aegypti with insecticides and larval source management. Despite these interventions, the dengue burden is increasing in Bangladesh, and the country experienced its worst outbreak in 2019 with 101 354 hospitalized cases. This may be partially facilitated by the presence of intense insecticide resistance in vector populations. Here, we describe the intensity and mechanisms of resistance to insecticides commonly deployed against Ae. aegypti in Dhaka, Bangladesh. RESULTS: Dhaka Ae. aegypti colonies exhibited high-intensity resistance to pyrethroids. Using CDC bottle assays, we recorded 2-24% mortality (recorded at 24 h) to permethrin and 48-94% mortality to deltamethrin, at 10× the diagnostic dose. Bioassays conducted using insecticide-synergist combinations suggested that metabolic mechanisms were contributing to pyrethroid resistance, specifically multi-function oxidases, esterases, and glutathione S-transferases. In addition, kdr alleles were detected, with a high frequency (78-98%) of homozygotes for the V1016G mutation. A large proportion (≤ 74%) of free-flying and resting mosquitoes from Dhaka colonies survived exposure to standard applications of pyrethroid aerosols in an experimental free-flight room. Although that exposure affected the immediate host-seeking behavior of Ae. aegypti, the effect was transient in surviving mosquitoes. CONCLUSION: The intense resistance characterized in this study is likely compromising the operational effectiveness of pyrethroids against Ae. aegypti in Dhaka. Switching to alternative chemical classes may offer a medium-term solution, but ultimately a more sustainable and effective approach to controlling dengue vectors is required. © 2023 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Principles and potential of solvent gradient size-exclusion chromatography for polymer analysis.

The properties of a polymeric material are influenced by its underlying molecular distributions, including the molecular-weight (MWD), chemical-composition (CCD), and/or block-length (BLD) distributions. Gradient-elution liquid chromatography (LC) is commonly used to determine the CCD. Due to the limited solubility of polymers, samples are often dissolved in strong solvents. Upon injection of the sample, such solvents may lead to broadened or poorly shaped peaks and, in unfavourable cases, to "breakthrough" phenomena, where a part of the sample travels through the column unretained. To remedy this, a technique called size-exclusion-chromatography gradients or gradient size-exclusion chromatography (gSEC) was developed in 2011. In this work, we aim to further explore the potential of gSEC for the analysis of the CCD, also in comparison with conventional gradient-elution reversed-phase LC, which in this work corresponded to gradient-elution reversed-phase liquid chromatography (RPLC). The influence of the mobile-phase composition, the pore size of the stationary-phase particles, and the column temperature were investigated. The separation of five styrene/ethyl acrylate copolymers was studied with one-dimensional RPLC and gSEC. RPLC was shown to lead to a more-accurate CCD in shorter analysis time. The separation of five styrene/methyl methacrylate copolymers was also explored using comprehensive two-dimensional (2D) LC involving gSEC, i.e. SEC × gSEC and SEC × RPLC. In 2D-LC, the use of gSEC was especially advantageous as no breakthrough could occur.

Immunogenicity of a single fractional intradermal dose of Japanese encephalitis live attenuated chimeric vaccine.

BACKGROUND: Japanese encephalitis (JE) is endemic in Asia and the western Pacific. Vaccination is recommended for travellers to endemic regions, but the high cost of the vaccine is a major barrier to uptake. METHODS: A quasi-experimental, pre-post intervention clinical trial without a control group was conducted to assess the immunogenicity and safety of intradermal (ID) JE vaccine. Healthy adults (18-45 years) received one dose of 0.1 mL (20% of standard dose) ID Imojev® (JE live attenuated chimeric vaccine, Sanofi-Aventis). Adverse events following immunization (AEFIs) were recorded 10 days post-vaccination. Blood samples were collected at baseline, 4 and 8 weeks post-vaccination. Neutralizing antibodies were measured using 50% plaque reduction neutralization test (PRNT50). Seroconversion was defined as PRNT50 titre ≥10. An in vitro study was also conducted to quantify the rate of decay of vaccine potency after reconstitution. RESULTS: In total, 51 participants (72.6% females, median age 31 years), all non-reactive to JE virus at baseline were enrolled. Mild and moderate AEFIs were reported by 19.6% of participants; none required medical attention or interfered with normal daily activities. All participants seroconverted at 4 weeks (GMT 249.3; 95%CI:192.8-322.5) and remained seropositive at 8 weeks (GMT 135.5; 95%CI:104.5-175.6). Vaccine potency declined at a rate of 0.14 log plaque-forming units/0.5 mL per hour. CONCLUSIONS: In healthy adults, a single 0.1 mL ID dose of Imojev was safe and immunogenic, at least in the short term. Reconstituted vials of Imojev vaccine may not retain their potency after 6 hours. Fractional JE ID vaccination could be a cheaper yet effective alternative for short-term travellers. Further studies need to investigate the immune response in a wider age range of individuals and the long-term immunogenicity of fractional JE ID vaccines. CLINICAL TRIALS REGISTRATION: ACTRN12621000024842.

Japanese Encephalitis Emergence in Australia: The Potential Population at Risk.

In Australia, Japanese encephalitis virus circulated in tropical north Queensland between 1995 and 2005. In 2022, a dramatic range expansion across the southern states has resulted in 30 confirmed human cases and 6 deaths. We discuss the outbreak drivers and estimate the potential size of the human population at risk.