Mitochondrial Sequencing Identifies Long Non-Coding RNA Features that Promote Binding to PNPase.

Extranuclear localization of long non-coding RNAs (lncRNAs) is poorly understood. Based on machine learning evaluations, we propose a lncRNA-mitochondrial interaction pathway where Polynucleotide Phosphorylase (PNPase), through domains that provide specificity for primary sequence and secondary structure, binds nuclear-encoded lncRNAs to facilitate mitochondrial import. Using FVB/NJ mouse and human cardiac tissues, RNA from isolated subcellular compartments (cytoplasmic and mitochondrial) and crosslinked immunoprecipitate (CLIP) with PNPase within the mitochondrion were sequenced on the Illumina HiSeq and MiSeq, respectively. LncRNA sequence and structure were evaluated through supervised (Classification and Regression Trees (CART) and Support Vector Machines, (SVM)) machine learning algorithms. In HL-1 cells, qPCR of PNPase CLIP knockout mutants (KH and S1) were performed. In vitro fluorescence assays assessed PNPase RNA binding capacity and verified with PNPase CLIP. 112 (mouse) and 1,548 (human) lncRNAs were identified in the mitochondrion with Malat1 being the most highly expressed. Most non-coding RNAs binding PNPase were lncRNAs, including Malat1. LncRNA fragments bound to PNPase compared against randomly generated sequences of similar length showed stratification with SVM and CART algorithms. The lncRNAs bound to PNPase were used to create a criterion for binding, with experimental validation revealing increased binding affinity of RNA designed to bind PNPase compared to control RNA. Binding of lncRNAs to PNPase was decreased through knockout of RNA binding domains KH and S1. In conclusion, sequence and secondary structural features identified by machine learning enhance the likelihood of nuclear-encoded lncRNAs to bind to PNPase and undergo import into the mitochondrion.

Treatment Failure in a UK Malaria Patient Harboring Genetically Variant Plasmodium falciparum From Uganda With Reduced In Vitro Susceptibility to Artemisinin and Lumefantrine.

BACKGROUND: Recent cases of clinical failure in malaria patients in the United Kingdom (UK) treated with artemether-lumefantrine have implications for malaria chemotherapy worldwide. METHODS: Parasites were isolated from an index case of confirmed Plasmodium falciparum treatment failure after standard treatment, and from comparable travel-acquired UK malaria cases. Drug susceptibility in vitro and genotypes at 6 resistance-associated loci were determined for all parasite isolates and compared with clinical outcomes for each parasite donor. RESULTS: A traveler, who returned to the UK from Uganda in 2022 with Plasmodium falciparum malaria, twice failed treatment with full courses of artemether-lumefantrine. Parasites from the patient exhibited significantly reduced susceptibility to artemisinin (ring-stage survival, 17.3% [95% confidence interval {CI}, 13.6%-21.1%]; P < .0001) and lumefantrine (effective concentration preventing 50% of growth = 259.4 nM [95% CI, 130.6-388.2 nM]; P = .001). Parasite genotyping identified an allele of pfk13 encoding both the A675V variant in the Pfk13 propeller domain and a novel L145V nonpropeller variant. In vitro susceptibility testing of 6 other P. falciparum lines of Ugandan origin identified reduced susceptibility to artemisinin and lumefantrine in 1 additional line, also from a 2022 treatment failure case. These parasites did not harbor a pfk13 propeller domain variant but rather the novel nonpropeller variant T349I. Variant alleles of pfubp1, pfap2mu, and pfcoronin were also identified among the 7 parasite lines. CONCLUSIONS: We confirm, in a documented case of artemether-lumefantrine treatment failure imported from Uganda, the presence of pfk13 mutations encoding L145V and A675V. Parasites with reduced susceptibility to both artemisinin and lumefantrine may be emerging in Uganda.

An integrative latent class model of heterogeneous data modalities for diagnosing kidney obstruction.

Radionuclide imaging plays a critical role in the diagnosis and management of kidney obstruction. However, most practicing radiologists in US hospitals have insufficient time and resources to acquire training and experience needed to interpret radionuclide images, leading to increased diagnostic errors. To tackle this problem, Emory University embarked on a study that aims to develop a computer-assisted diagnostic (CAD) tool for kidney obstruction by mining and analyzing patient data comprised of renogram curves, ordinal expert ratings on the obstruction status, pharmacokinetic variables, and demographic information. The major challenges here are the heterogeneity in data modes and the lack of gold standard for determining kidney obstruction. In this article, we develop a statistically principled CAD tool based on an integrative latent class model that leverages heterogeneous data modalities available for each patient to provide accurate prediction of kidney obstruction. Our integrative model consists of three sub-models (multilevel functional latent factor regression model, probit scalar-on-function regression model, and Gaussian mixture model), each of which is tailored to the specific data mode and depends on the unknown obstruction status (latent class). An efficient MCMC algorithm is developed to train the model and predict kidney obstruction with associated uncertainty. Extensive simulations are conducted to evaluate the performance of the proposed method. An application to an Emory renal study demonstrates the usefulness of our model as a CAD tool for kidney obstruction.

A Halogen Bonding [2]Rotaxane Shuttle for Chloride-Selective Optical Sensing.

The first example of a [2]rotaxane shuttle capable of selective optical sensing of chloride anions over other halides is reported. The rotaxane was synthesised via a chloride ion template-directed cyclisation of an isophthalamide macrocycle around a multi-station axle containing peripheral naphthalene diimide (NDI) stations and a halogen bonding (XB) bis(iodotriazole) based station. Proton NMR studies indicate the macrocycle resides preferentially at the NDI stations in the free rotaxane, where it is stabilised by aromatic donor-acceptor charge transfer interactions between the axle NDI and macrocycle hydroquinone moieties. Addition of chloride ions in an aqueous-acetone solvent mixture induces macrocycle translocation to the XB anion binding station to facilitate the formation of convergent XB⋅⋅⋅Cl- and hydrogen bonding HB⋅⋅⋅Cl- interactions, which is accompanied by a reduction of the charge-transfer absorption band. Importantly, little to no optical response was induced by addition of bromide or iodide to the rotaxane, indicative of the size discriminative steric inaccessibility of the interlocked cavity to the larger halides, demonstrating the potential of using the mechanical bond effect as a potent strategy and tool in chloride-selective chemo-sensing applications in aqueous containing solvent environments.

HeartMate 3 implantation with an emphasis on the biventricular configuration.

OBJECTIVES: Right ventricular failure following implantation of a durable left ventricular assist device (LVAD) is a major driver of mortality. Reported survival following biventricular (BiVAD) or total artificial heart (TAH) implantation remains substantially inferior to LVAD alone. We report our outcomes with LVAD and BiVAD HeartMate 3 (HM3). METHODS: Consecutive patients undergoing implantation of an HM3 LVAD between November 2014 and December 2021, at The Alfred, Australia were included in the study. Comparison was made between the BiVAD and LVAD alone groups. RESULTS: A total of 86 patients, 65 patients with LVAD alone and 21 in a BiVAD configuration underwent implantation. The median age of the LVAD and BiVAD groups was 56 years (Interquartile range 46-62) and 49 years (Interquartile range 37-55), respectively. By 4 years after implantation, 54% of LVAD patients and 43% of BiVAD patients had undergone cardiac transplantation. The incidence of stroke in the entire experience was 3.5% and pump thrombosis 5% (all in the RVAD). There were 14 deaths in the LVAD group and 1 in the BiVAD group. The actuarial survival for LVAD patients at 1 year was 85% and BiVAD patients at 1 year was 95%. CONCLUSIONS: The application of HM 3 BiVAD support in selected patients appears to offer a satisfactory solution to patients requiring biventricular support.

2024 CSANZ Position Statement on Indications, Assessment and Monitoring of Structural and Valvular Heart Disease With Transthoracic Echocardiography in Adults.

Transthoracic echocardiography (TTE) is the most widely available and utilised imaging modality for the screening, diagnosis, and serial monitoring of all abnormalities related to cardiac structure or function. The primary objectives of this document are to provide (1) a guiding framework for treating clinicians of the acceptable indications for the initial and serial TTE assessments of the commonly encountered cardiovascular conditions in adults, and (2) the minimum required standard for TTE examinations and reporting for imaging service providers. The main areas covered within this Position Statement pertain to the TTE assessment of the left and right ventricles, valvular heart diseases, pericardial diseases, aortic diseases, infective endocarditis, cardiac masses, pulmonary hypertension, and cardiovascular diseases associated with cancer treatments or cardio-oncology. Facilitating the optimal use and performance of high quality TTEs will prevent the over or under-utilisation of this resource and unnecessary downstream testing due to suboptimal or incomplete studies.

Anion Sensing through Redox-Modulated Fluorescent Halogen Bonding and Hydrogen Bonding Hosts.

Anion sensing via either optical or electrochemical readouts has separately received enormous attention, however, a judicious combination of the advantages of both modalities remains unexplored. Toward this goal, we herein disclose a series of novel, redox-active, fluorescent, halogen bonding (XB) and hydrogen bonding (HB) BODIPY-based anion sensors, wherein the introduction of a ferrocene motif induces remarkable changes in the fluorescence response. Extensive fluorescence anion titration, lifetime and electrochemical studies reveal anion binding-induced emission modulation through intramolecular photoinduced electron transfer (PET), the magnitude of which is dependent on the nature of both the XB/HB donor and anion. Impressively, the XB sensor outperformed its HB congener in terms of anion binding strength and fluorescence switching magnitude, displaying significant fluorescence turn-OFF upon anion binding. In contrast, redox-inactive control receptors display a turn-ON response, highlighting the pronounced impact of the introduction of the redox-active ferrocene on the optical sensing performance. Additionally, the redox-active ferrocene motif also serves as an electrochemical reporter group, enabling voltammetric anion sensing in competitive solvents. The combined advantages of both sensing modalities were further exploited in a novel, proof-of-principle, fluorescence spectroelectrochemical anion sensing approach, enabling simultaneous and sensitive read out of optical and electrochemical responses in multiple oxidation states and at very low receptor concentration.

Alcohol Abstinence in Drinkers with Atrial Fibrillation.

BACKGROUND: Excessive alcohol consumption is associated with incident atrial fibrillation and adverse atrial remodeling; however, the effect of abstinence from alcohol on secondary prevention of atrial fibrillation is unclear. METHODS: We conducted a multicenter, prospective, open-label, randomized, controlled trial at six hospitals in Australia. Adults who consumed 10 or more standard drinks (with 1 standard drink containing approximately 12 g of pure alcohol) per week and who had paroxysmal or persistent atrial fibrillation in sinus rhythm at baseline were randomly assigned in a 1:1 ratio to either abstain from alcohol or continue their usual alcohol consumption. The two primary end points were freedom from recurrence of atrial fibrillation (after a 2-week "blanking period") and total atrial fibrillation burden (proportion of time in atrial fibrillation) during 6 months of follow-up. RESULTS: Of 140 patients who underwent randomization (85% men; mean [±SD] age, 62±9 years), 70 were assigned to the abstinence group and 70 to the control group. Patients in the abstinence group reduced their alcohol intake from 16.8±7.7 to 2.1±3.7 standard drinks per week (a reduction of 87.5%), and patients in the control group reduced their alcohol intake from 16.4±6.9 to 13.2±6.5 drinks per week (a reduction of 19.5%). After a 2-week blanking period, atrial fibrillation recurred in 37 of 70 patients (53%) in the abstinence group and in 51 of 70 patients (73%) in the control group. The abstinence group had a longer period before recurrence of atrial fibrillation than the control group (hazard ratio, 0.55; 95% confidence interval, 0.36 to 0.84; P = 0.005). The atrial fibrillation burden over 6 months of follow-up was significantly lower in the abstinence group than in the control group (median percentage of time in atrial fibrillation, 0.5% [interquartile range, 0.0 to 3.0] vs. 1.2% [interquartile range, 0.0 to 10.3]; P = 0.01). CONCLUSIONS: Abstinence from alcohol reduced arrhythmia recurrences in regular drinkers with atrial fibrillation. (Funded by the Government of Victoria Operational Infrastructure Support Program and others; Australian New Zealand Clinical Trials Registry number, ACTRN12616000256471.).

The Neuropeptide Alpha-Melanocyte-Stimulating Hormone Is Critical for Corneal Endothelial Cell Protection and Graft Survival after Transplantation.

Corneal transplantation is the most common form of tissue transplantation. The success of corneal transplantation mainly relies on the integrity of corneal endothelial cells (CEnCs), which maintain tissue transparency by pumping out excess water from the cornea. After transplantation, the rate of CEnC loss far exceeds that seen with normal aging, which can threaten sight. The underlying mechanisms are poorly understood. Alpha-melanocyte-stimulating hormone (α-MSH) is a neuropeptide that is constitutively found in the aqueous humor with both cytoprotective and immunomodulatory effects. The curent study found high expression of melanocortin 1 receptor (MC1R), the receptor for α-MSH, on CEnCs. The effect of α-MSH/MC1R signaling on endothelial function and allograft survival in vitro and in vivo was investigated using MC1R signaling-deficient mice (Mc1re/e mice with a nonfunctional MC1R). Herein, the results indicate that in addition to its well-known immunomodulatory effect, α-MSH has cytoprotective effects on CEnCs after corneal transplantation, and the loss of MC1R signaling significantly decreases long-term graft survival in vivo. In conclusion, α-MSH/MC1R signaling is critical for CEnC function and graft survival after corneal transplantation.

The impact of age on ablation outcomes in AF-mediated cardiomyopathy.

INTRODUCTION: The absence of ventricular scar in patients with atrial fibrillation (AF) and systolic heart failure (HF) predicts left ventricular (LV) recovery following AF ablation. It is unknown whether age impacts the degree of LV recovery, reverse remodeling, or AF recurrence following catheter ablation (CA) among this population. OBJECTIVES: To evaluate the impact of age on LV recovery and AF recurrence in a population with AF and systolic HF without fibrosis (termed AF-mediated cardiomyopathy) following CA. METHODS: Consecutive patients undergoing CA between 2013 and 2021 with LV ejection fraction (LVEF) < 45% and absence of cardiac magnetic resonance imaging (CMR) detected LV myocardial fibrosis were stratified by age (<65 vs. ≥65 years). Following CA, participants underwent remote rhythm monitoring for 12 months with repeat CMR for HF surveillance. RESULTS: The study population consisted of 70 patients (10% female, mean LVEF 33 ± 9%), stratified into younger (age < 65 years, 63%) and older (age ≥ 65 years, 37%) cohorts. Baseline comorbidities, LVEF (34 ± 9 vs. 33 ± 8 ≥65 years, p = .686), atrial and ventricular dimensions (left atrial volume index: 55 ± 21 vs. 56 ± 14 mL/m2 age ≥ 65, p = .834; indexed left ventricular end-diastolic volume: 108 ± 40 vs. 104 ± 28 mL/m2 age ≥ 65, p = .681), pharmacotherapy and ablation strategy (pulmonary vein isolation in all; posterior wall isolation in 27% vs. 19% age ≥ 65, p = .448; cavotricuspid isthmus in 9% vs. 11.5% age ≥ 65) were comparable (all p > .05) albeit a higher CHADS2 VASc score in the older cohort (2.7 ± 0.9 vs. 1.6 ± 0.6 age < 65, p < .001).   Freedom from AF was comparable (hazard ratio: 0.65, 95% confidence interval: 0.38-1.48, LogRank p = .283) as was AF burden [0% (interquartile range, IQR: 0.0-2.1) vs. age ≥ 65: [0% (IQR 0.0-1.7), p = .516], irrespective of age. There was a significant improvement in LV systolic function in both groups (ΔLVEF + 21 ± 14% vs. +21 ± 12% age ≥ 65, p = .913), with LV recovery in the vast majority (73% vs. 69%, respectively, p = .759) at 13 (IQR: 12-16) months. This was accompanied by comparable improvements in functional status (New York Heart Association class p = .851; 6-min walk distance 50 ± 61 vs. 93 ± 134 m in age ≥ 65, p = .066), biomarkers (ΔN-terminal-pro brain natriuretic peptide -139 ± 246 vs. -168 ± 181 age ≥ 65,p = .629) and HF symptoms (Short Form-36 survey Δphysical component summary p = .483/Δmental component summary, p = .841). CONCLUSION: In patients undergoing CA for AF with systolic HF in the absence of ventricular scar, comparable improvements in ventricular function, symptoms, and freedom from AF are achieved irrespective of age.

Cyaphide-Azide 1,3-Dipolar Cycloaddition Reactions: Scope and Applicability.

Several examples of the cyaphide-azide 1,3-dipolar cycloaddition reaction to afford metallo-triazaphospholes are reported. The gold(I) triazaphospholes Au(IDipp)(CPN3 R) (IDipp=1,3-bis(2,6-diisopropylphenyl)imidazol-2-ylidene; R=t Bu, Ad, Dipp), magnesium(II) triazaphospholes, {Mg(Dipp NacNac)(CPN3 R)}2 (Dipp NacNac=CH{C(CH3 )N(Dipp)}2 , Dipp=2,6-diisopropylphenyl; R=t Bu, Bn), and germanium(II) triazaphosphole Ge(Dipp NacNac)-(CPN3 t Bu) can be prepared straightforwardly, under mild conditions and in good yields, in a manner reminiscent of the classic alkyne-azide click reaction (albeit without a catalyst). This reactivity can be extended to compounds with two azide functional groups such as 1,3-diazidobenzene. It is shown that the resulting metallo-triazaphospholes can be used as precursors to carbon-functionalized species, including protio- and iodo-triazaphospholes.

Location and appearance of dysplastic Barrett's esophagus recurrence after endoscopic eradication therapy: no additional yield from random biopsy sampling neosquamous mucosa.

BACKGROUND AND AIMS: Surveillance after complete remission of intestinal metaplasia (CRIM) is essential. Current recommendations are to sample visible lesions first, followed by random 4-quadrant biopsy sampling of the original Barrett's esophagus (BE) length. To inform post-CRIM surveillance protocols, we aimed to identify the anatomic location, appearance, and histology of BE recurrences. METHODS: We performed an analysis of 216 patients who achieved CRIM after endoscopic eradication therapy for dysplastic BE at a Barrett's Referral Unit between 2008 and 2021. The anatomic location, recurrence histology, and endoscopic appearance of dysplastic recurrences were evaluated. RESULTS: After a median of 5.5 years (interquartile range, 2.9-7.2) of follow-up after CRIM, 57 patients (26.4%) developed nondysplastic BE (NDBE) recurrence and 18 patients (8.3%) developed dysplastic recurrence. From 8158 routine surveillance biopsy samplings of normal-appearing tubular esophageal neosquamous epithelium, the yield for recurrent NDBE or dysplasia was 0%. One hundred percent of dysplastic tubular esophageal recurrences were visible and in BE islands, whereas 77.8% of gastroesophageal junction dysplastic recurrences were nonvisible. Four distinct endoscopic features suspicious for recurrent advanced dysplasia or neoplasia were identified: buried or subsquamous BE, irregular mucosal pattern, loss of vascular pattern, and nodularity or depression. CONCLUSIONS: The yield of routine surveillance biopsy sampling of normal-appearing tubular esophageal neosquamous epithelium was zero. BE islands with indistinct mucosal or loss of vascular pattern, nodularity or depression, and/or signs of buried BE should raise clinician suspicion for advanced dysplasia or neoplasia recurrence. We suggest a new surveillance biopsy sampling protocol with a focus on meticulous inspection, followed by targeted biopsy sampling of visible lesions and random 4-quadrant biopsy sampling of the gastroesophageal junction.

Incidence and severity of cytomegalovirus infection in seropositive heart transplant recipients.

BACKGROUND: The frequency and significance of cytomegalovirus (CMV) infection in seropositive (R+) heart transplant recipients (HTR) is unclear, with preventative recommendations mostly extrapolated from other groups. We evaluated the incidence and severity of CMV infection in R+ HTR, to identify risk factors and describe outcomes. METHODS: R+ HTR from 2010 to 2019 were included. Antiviral prophylaxis was not routinely used, with clinically guided monitoring the local standard of care. The primary outcome was CMV infection within one-year post-transplant; secondary outcomes included other herpesvirus infections and mortality. RESULTS: CMV infection occurred in 27/155 (17%) R+ HTR. Patients with CMV had a longer hospitalization (27 vs. 20 days, unadjusted HR 1.02, 95% CI 1.00-1.02, p = .01), higher rate of intensive care readmission (26% vs. 9%, unadjusted HR 3.46, 1.46-8.20, p = .005), and increased mortality (33% vs. 8%, unadjusted HR 10.60, 4.52-24.88, p < .001). The association between CMV and death persisted after adjusting for multiple confounders (HR 24.19, 95% CI 7.47-78.30, p < .001). Valganciclovir prophylaxis was used in 35/155 (23%) and was protective against CMV (infection rate 4% vs. 27%, adjusted HR .07, .01-.72, p = .025), even though those receiving it were more likely to have received thymoglobulin (adjusted OR 10.5, 95% CI 2.01-55.0, p = .005). CONCLUSIONS: CMV infection is common in R+ HTR and is associated with a high burden of disease and increased mortality. Patients who received valganciclovir prophylaxis were less likely to develop CMV infection, despite being at higher risk. These findings support the routine use of antiviral prophylaxis following heart transplantation in all CMV R+ patients.

Inter-annual Persistence of Canopy Fungi Driven by Abundance Despite High Spatial Turnover.

While it is now well established that fungal community composition varies spatially at a variety of scales, temporal turnover of fungi is less well understood. Here we studied inter-annual community compositional changes of fungi in a rainforest tree canopy environment. We tracked fungal community shifts over 3 years in three substrate types (live bryophytes, dead bryophytes, and host tree bark) and compared these changes to amounts of community turnover seen at small spatial scales in the same system. The effect of substrate type on fungal community composition was stronger than that of sampling year, which was very small but significant. Although levels of temporal turnover varied among substrates, with greater turnover in live bryophytes than other substrates, the amount of turnover from year to year was comparable to what is seen at spatial distances between 5 and 9 cm for the same substrate. Stability of communities was largely driven by a few fungi with high relative abundances. A majority of fungal occurrences were at low relative abundances (≤ 0.1%). These fungi tended to be short lived and persisted to following years ≤ 50% of the time, depending on substrate. Their presence and persistence are likely impacted by stochastic processes like dispersal limitation and disturbance. Most samples contained only one or a few fungi at high relative abundance (≥ 10%) that persisted half or more of the time. These more abundant and persistent fungi are expected to have sustained functional interactions within the canopy ecosystem.

Antimicrobial resistance of breakthrough urinary tract infections in young children receiving continual antibiotic prophylaxis.

Continual antibiotic prophylaxis (CAP) can reduce the risk of recurrent UTI (rUTI). However, antimicrobial resistance in subsequent UTIs is a concern. This study aimed to explore antimicrobial resistance in young children prescribed CAP for rUTIs. A retrospective review of patient records/microbiology results was undertaken for children < 2 years of age, on CAP, with 2-3 clean catch/mid-stream/supra-pubic aspirate urine cultures with a pure growth of bacteria, between January 2017 and December 2019. One hundred twenty-four urine specimens from 54 patients (26 (48%) males, median age 6 months) were analysed. CAP prescribed was trimethoprim in 37 (69%), cefalexin in 11 (29%), and nitrofurantoin in 6 (11%). Based on antimicrobial susceptibility of the index UTI within the study period, 41 patients (76%) grew organisms on urine culture classified as sensitive and 13 (24%) resistant. Thirty-five (65%) children had congenital anomaly of the kidneys and urinary tract (CAKUT); they were more likely to be in the resistant group (P = 0.032). Escherichia coli (37/54, 69%) was the commonest index uropathogen. The resistant group had a higher proportion of non-E. coli index UTI pathogens (P = 0.098). Breakthrough UTI with a CAP-resistant organism was more likely in the resistant group (P = 0.010). Age, sex, and kidney scarring on DMSA (dimercaptosuccinic acid) scan were not significantly different between groups.  Conclusion: Over a 3-year period, the proportion of children on CAP with resistant organism UTI doubled and resistant infections were more likely in children with CAKUT. Development of non-antimicrobial prophylaxis options is required. What is Known: • Recurrent urinary tract infections are common in children, particularly in those with underlying anatomical abnormalities of the kidneys and urinary tract. • Continuous antibiotic prophylaxis is used frequently in these children, however there is a lack of consensus on whether the potential benefits of CAP outweigh the harms. What is New: • This study adds further evidence towards the consequences of using continuous antibiotic prophylaxis in recurrent UTI; specifically, a 2-fold increase in antimicrobial resistance was seen in subsequent UTIs following long-term use of CAP, providing further vigour for the need for non-antibiotic alternatives.

Direct percutaneous endoscopic gastrostomy for nutritional support in patients with aerodigestive tract cancers.

BACKGROUND: Conventional pull-through percutaneous endoscopic gastrostomy (PEG) risks infection and tumour implantation in head and neck cancers. Endoscopically inserted direct gastrostomy has lower rates of complications but is underutilised. AIMS: To describe the endoscopic steps for direct gastrostomy insertion and review our single-centre experience to assess the technical feasibility and safety. METHODS: Patients who underwent endoscopic direct gastrostomy insertion between December 2016 and June 2021 were included. A 24Fr introducer kit for gastrostomy feeding tube (Avanos Healthcare, Australia) was used. Patient and tumour characteristics, procedural data and 30-day outcomes were recorded. RESULTS: Thirty patients underwent direct PEG insertion (mean age 64 years and 24 male). All were planned for or currently undergoing radiotherapy. Twenty-six (87%) of 30 cases were performed under conscious sedation over a median procedure time of 21 min (interquartile range 11 min). No tumour seeding was seen, and one case of PEG-site infection was observed. CONCLUSIONS: Direct PEG is safe and effective and should be considered for patients with aerodigestive tract cancer in need of nutritional support.

Estimating age-specific mortality using calibrated splines.

Demographers have developed a number of methods for expanding abridged mortality data into a complete schedule; however, these can be usefully applied only under certain conditions, and the presence or absence of one or more additional sources of incompleteness can degrade their relative accuracy, lead to implausible profiles, or even cause the methods to fail. We develop a new method for expanding an abridged schedule based on calibrated splines; this method is accurate and robust in the presence of errors in mortality rates, missing values, and truncation. We compare its performance with the performance of existing methods for expanding abridged data and find that it is superior to current methods at producing accurate and plausible complete schedules over a broad range of data-quality conditions. The method when applied is a valuable addition to existing tools for estimating mortality, especially for small nations, countries with incomplete vital statistics, and subnational populations.

Healthcare cost burden of acute chest pain presentations.

BACKGROUND: This study aimed to estimate the direct healthcare cost burden of acute chest pain attendances presenting to ambulance in Victoria, Australia, and to identify key cost drivers especially among low-risk patients. METHODS: State-wide population-based cohort study of consecutive adult patients attended by ambulance for acute chest pain with individual linkage to emergency and hospital admission data in Victoria, Australia (1 January 2015-30 June 2019). Direct healthcare costs, adjusted for inflation to 2020-2021 ($A), were estimated for each component of care using a casemix funding method. RESULTS: From 241 627 ambulance attendances for chest pain during the study period, mean chest pain episode cost was $6284, and total annual costs were estimated at $337.4 million ($68 per capita per annum). Total annual costs increased across the period ($310.5 million in 2015 vs $384.5 million in 2019), while mean episode costs remained stable. Cardiovascular conditions (25% of presentations) were the most expensive (mean $11 523, total annual $148.7 million), while a non-specific pain diagnosis (49% of presentations) was the least expensive (mean $3836, total annual $93.4 million). Patients classified as being at low risk of myocardial infarction, mortality or hospital admission (Early Chest pain Admission, Myocardial infarction, and Mortality (ECAMM) score) represented 31%-57% of the cohort, with total annual costs estimated at $60.6 million-$135.4 million, depending on the score cut-off used. CONCLUSIONS: Total annual costs for acute chest pain presentations are increasing, and a significant proportion of the cost burden relates to low-risk patients and non-specific pain. These data highlight the need to improve the cost-efficiency of chest pain care pathways.

Comparison of Chemical and Electrochemical Approaches to Abacavir Oxidative Stability Testing.

A novel electrochemical approach using two different electrode materials, platinum and boron-doped diamond (BDD), was employed to study the oxidative stability of the drug abacavir. Abacavir samples were subjected to oxidation and subsequently analysed using chromatography with mass detection. The type and amount of degradation products were evaluated, and results were compared with traditional chemical oxidation using 3% hydrogen peroxide. The effect of pH on the rate of degradation and the formation of degradation products were also investigated. In general, both approaches led to the same two degradation products, identified using mass spectrometry, and characterised by 319.20 and m/z 247.19. Similar results were obtained on a large-surface platinum electrode at a potential of +1.15 V and a BDD disc electrode at +4.0 V. Degradation of 20% of abacavir, the rate required for pharmaceutical stability studies, took only a few minutes compared to hours required for oxidation with hydrogen peroxide. Measurements further showed that electrochemical oxidation in ammonium acetate on both types of electrodes is strongly pHdependent. The fastest oxidation was achieved at pH 9. The pH also affects the composition of the products, which are formed in different proportions depending on the pH of the electrolyte.

Stimulating the Melanocortin System in Uveitis and Diabetes Preserves the Structure and Anti-Inflammatory Activity of the Retina.

The endogenous neuropeptide α-Melanocyte Stimulating Hormone (α-MSH) is a potent suppressor of inflammation and has an essential role in maintaining the normal anti-inflammatory microenvironment of the retina. While the therapeutic use of α-MSH peptide in uveitis and diabetic retinopathy models has been demonstrated, its short half-life and instability limit its use as a therapeutic drug. A comparable analog, PL-8331, which has a stronger affinity to melanocortin receptors, longer half-life, and, so far, is functionally identical to α-MSH, has the potential to deliver melanocortin-based therapy. We examined the effects of PL-8331 on two mouse models of retinal disease, Experimental Autoimmune Uveoretinitis (EAU) and Diabetic Retinopathy (DR). PL-8331 therapy applied to mice with EAU suppressed EAU and preserved retinal structures. In diabetic mice, PL-8331 enhanced the survival of retinal cells and suppressed VEGF production in the retina. In addition, retinal pigment epithelial cells (RPE) from PL-8331-treated diabetic mice retained normal anti-inflammatory activity. The results demonstrated that the pan-melanocortin receptor agonist PL-8331 is a potent therapeutic drug to suppress inflammation, prevent retinal degeneration, and preserve the normal anti-inflammatory activity of RPE.