Renal Tubular Acidosis: Core Curriculum 2025.

Renal tubular acidoses (RTAs) are a subset of non-anion gap metabolic acidoses that result from complex disturbances in renal acid excretion. Net acid excretion is primarily accomplished through the reclamation of sodium bicarbonate and the buffering of secreted protons with ammonia or dibasic phosphate, all of which require a series of highly complex and coordinated processes along the renal tubule. Flaws in any of these components lead to the development of metabolic acidosis and/or a failure to compensate fully for other systemic acidoses.

Infection-Associated Glomerulonephritis.

The nephritic syndrome has been associated with a wide variety of infections, spanning many organisms and myriad clinical presentations. Infection-associated glomerulonephritis is challenging to diagnose given the many confounding factors linking kidney injury to infection; however, urine microscopy can assist in identifying abnormal cellular elements suggestive of glomerulonephritis. Kidney biopsy remains the gold standard for diagnosing the underlying pathologic lesion.

The effect of acute hydration on body composition assessed by multi-frequency and single-frequency bioelectrical impedance.

Background: Multi-frequency bioelectrical impedance (MF-BIA) provides an estimate of total body water. However, it is unknown if MF-BIA detects body water increases due to acute hydration, thus affecting the validity of MF-BIA body composition measurements. The purpose of this study was to compare the effects of pre-testing fluid ingestion on body composition estimation using single-frequency bioelectrical impedance (SF-BIA) and MF-BIA.

COVID-19 pandemic in long-term care: An international perspective for policy considerations.

This paper identifies key factors rooted in the systemic failings of the long-term care sector amongst four high income countries during the COVID-19 pandemic. The goal is to offer practice and policy solutions to prevent future tragedies. Based on data from Australia, Canada, Spain and the United States, the findings support evidence-based recommendations at macro, meso and micro levels of practice and policy intervention.

Impact of Temperature and Oxygen Availability on Gene Expression Patterns of Mycobacterium ulcerans.

Buruli ulcer disease is a neglected tropical disease caused by the environmental pathogen Mycobacterium ulcerans. The M. ulcerans major virulence factor is mycolactone, a lipid cytotoxic compound whose genes are carried on a plasmid.

Assessing the Potential of Untargeted SWATH Mass Spectrometry-Based Metabolomics to Differentiate Closely Related Exposures in Observational Studies.

Mass spectrometry (MS) is increasingly used in clinical studies to obtain molecular evidence of chemical exposures, such as tobacco smoke, alcohol, and drugs. This evidence can help verify clinical data retrieved through anamnesis or questionnaires and may provide insights into unreported exposures, for example those classified as the same despite small but possibly relevant chemical differences or due to contaminants in reported exposure compounds. Here, we aimed to explore the potential of untargeted SWATH metabolomics to differentiate such closely related exposures.

Controlled Formation of Protonated and Radical Cation Precursor Ions by Atmospheric Pressure Photoionization with μLC-MS Enables Electron Ionization and MS/MS Library Search.

Atmospheric pressure photoionization (APPI) was developed as an alternative to electrospray ionization (ESI) for the generation of protonated molecules using liquid chromatography and optimized using dopants such as toluene, which predominantly forms protonated molecules, and chlorobenzene, which favors the formation of radical cations, although the latter has not been fully exploited. Based on 40 diverse low-molecular-weight compounds and micro liquid chromatography (μLC) coupled with APPI tandem mass spectrometry (APPI-MS/MS), the potential of radical cations was investigated. Chromatographic and ionization conditions were decoupled by post-column addition of methanol, allowing separate study and optimization.

Untargeted 'SWATH' mass spectrometry-based metabolomics for studying chronic and intermittent exposure to xenobiotics in cohort studies.

Humans are exposed to numerous chemicals daily, for example through nutrition, therapies, and lifestyle choices, which may exert beneficial or toxicological responses. In cohort studies, exposures are frequently assessed using questionnaires, although mass spectrometry-based metabolomics has recently emerged as complementary technique capable of yielding molecular evidence of exposures. Corresponding data processing workflows, however, have been mostly developed for detecting (omnipresent) endogenous metabolites, whereas detection of exogenous chemicals would benefit from fit-for-purpose strategies.

Annotation of complex mass spectra by multi-layered analysis.

Annotating electrospray small molecule mass spectra remains a challenging problem due to the multiple processes occurring during ionization. Although an [M+H] is often present, ions can be formed by reactions with other cations, background compounds and co-eluting species, and by in-source fragmentation. Even single analytes can produce multiple ion forms, many of which remain unidentified and may appear to be different species, affecting reproducibility, quantification and precursor selection in DDA experiments.

A Primary Care Intervention to Increase HIV Pre-Exposure Prophylaxis (PrEP) Uptake in Patients with Syphilis.

Identifying candidates for HIV pre-exposure prophylaxis (PrEP) is a barrier to improving PrEP uptake in priority populations. Syphilis infection is an indication for PrEP in all individuals and can be easily assessed by primary care providers (PCP) and health systems. This retrospective study evaluated the impact of a multidisciplinary provider outreach intervention on PrEP uptake in patients with a positive syphilis test result in a safety-net hospital-based primary care practice.

Monitor gastrointestinal tolerance in children who have switched to an "enteral formula with food-derived ingredients": A national, multicenter retrospective chart review (RICIMIX study).

Background: Enteral tube feeding intolerances, such as diarrhea, are commonly reported in children. In the pediatric population, interest is growing in the use of blended diets for the management of enteral feeding intolerances. Fiber within a blended diet stimulates the growth of beneficial gut bacteria, which in turn produce short-chain fatty acids, which are utilized as energy substrates for enterocytes.

National audit to assess standards of care for deliberate self-harm patients presenting to trauma centres with penetrating wounds and recommendations for action.

Background: The authors assessed the standard of care for patients presenting with deliberate self-harm (DSH) injuries to major trauma centres (MTCs) in England as well as hospitals within the major trauma network in Scotland. This was to generate an understanding of current practice, identify any shortfall and develop recommendations to improve safety and patient care.

Methods: We contacted all MTCs in England and hospitals in the major trauma network in Scotland, asking their permission to be included in this study.

The Content of Pre-habilitative Interventions for Patients Undergoing Repair of Abdominal Aortic Aneurysms and Their Effect on Post-Operative Outcomes: A Systematic Review.

Objective: Patients requiring abdominal aortic aneurysm (AAA) repair are at risk of post-operative complications due to poor pre-operative state. Pre-habilitation describes the enhancement of functional capacity and tolerance to an upcoming physiological stressor, intended to reduce those complications. The ability to provide such an intervention (physical, pharmacological, nutritional, or psychosocial) between diagnosis and surgery is a growing interest, but its role in AAA repair is unclear.

Improved metabolite characterization by liquid chromatography - Tandem mass spectrometry through electron impact type fragments from adduct ions.

Using a chimeric collision cell mounted on a quadrupole time-of-flight platform, collision induced dissociation (CID) and electron induced dissociation (EID) were investigated for the LC-MS analysis of low molecular weight compounds including drugs and endogenous metabolites. Compared to CID, EID fragmentation of the [M+H] species (10-20 eV) from standard compounds resulted in additional specific and informative fragments, mostly due to neutral losses and, in some cases due to ring openings. Some analytes, for example reserpine and vinpocetine, provided characteristic [M+H] species.

Metabolomics data complemented drug use information in epidemiological databases: pilot study of potential kidney donors.

Objective: The objective of this study was to investigate whether clinical metabolomics, which is increasingly applied in population-based and epidemiological studies, can be used to provide analytical evidence of exposures, and whether such information can be useful to strengthen and/or complement corresponding clinical database entries, taking drug use as an example.

Study Design And Setting: Liquid chromatography-mass spectrometry (LC-MS) metabolomics analyses were performed on urine from 100 randomly-selected control subjects (50% females) from the TransplantLines Food and Nutrition Biobank and Cohort Study (NCT identifier 'NCT02811835'), and drugs were identified through spectral library searching and targeted signal extraction.

Results: In 83 subjects for whom drug use information was available, 22 expected and 26 unexpected prescription-only drugs were identified, while 28 expected prescription-only drugs remained undetected.

Adduct annotation in liquid chromatography/high-resolution mass spectrometry to enhance compound identification.

Annotation and interpretation of full scan electrospray mass spectra of metabolites is complicated by the presence of a wide variety of ions. Not only protonated, deprotonated, and neutral loss ions but also sodium, potassium, and ammonium adducts as well as oligomers are frequently observed. This diversity challenges automatic annotation and is often poorly addressed by current annotation tools.

Diabetic Kidney Disease.

Diabetic kidney disease (DKD) is the most common cause of chronic kidney disease in the United States. Approximately 30% to 40% of individuals with diabetes mellitus develop DKD, and the presence of DKD significantly elevates the risk for morbidity and mortality. Understanding of DKD has grown in recent years.

Operationalizing an academic pediatric practice during the COVID-19 crisis.

We report on innovating protocols at an Academic Pediatric practice during the COVID-19 (2019 novel coronavirus) crisis. Facing the challenges of limited personal protective equipment and testing capacity, we rapidly and efficiently changed processes to optimize infection control, providing safe and effective care for our vulnerable population.

SWATH-MS for metabolomics and lipidomics: critical aspects of qualitative and quantitative analysis.

Introduction: While liquid chromatography coupled to mass spectrometric detection in the selected reaction monitoring detection mode offers the best quantification sensitivity for omics, the number of target analytes is limited, must be predefined and specific methods developed. Data independent acquisition (DIA), including SWATH using quadrupole time of flight or orbitrap mass spectrometers and generic acquisition methods, has emerged as a powerful alternative technique for quantitative and qualitative analyses since it can cover a wide range of analytes without predefinition.

Objectives: Here we review the current state of DIA, SWATH-MS and highlight novel acquisition strategies for metabolomics and lipidomics and opportunities for data analysis tools.

SWATH data independent acquisition mass spectrometry for screening of xenobiotics in biological fluids: Opportunities and challenges for data processing.

SWATH data independent acquisition (DIA) mass spectrometry (MS) has become an established technique in MS-based 'omics' research and is increasingly used for the screening of xenobiotics (e.g. drugs, drug metabolites, pesticides, toxicants).

Establishing and Sustaining a Culture of Evidence-Based Practice: An Evaluation of Barriers and Facilitators to Implementing the Best Practice Spotlight Organization Program in the Australian Healthcare Context.

Background: Nurses and midwives are central to the implementation and delivery of quality care through evidence-based practice (EBP). However, implementation of EBP in nursing and midwifery is under-researched with few examples of systematic and sustained change. The Registered Nurses Association of Ontario's Best-Practice Spotlight Organization (BPSO) Program was adopted in South Australia as a framework to systematically implement EBP in two diverse and complex healthcare settings.

Hybrid SWATH/MS and HR-SRM/MS acquisition for phospholipidomics using QUAL/QUANT data processing.

A hybrid SWATH/MS and HR-SRM/MS acquisition approach using multiple unit mass windows and 100 u precursor selection windows has been developed to interface with a chromatographic lipid class separation. The method allows for the simultaneous monitoring of sum compositions in MS1 and up to 48 lipids in MS2 per lipid class. A total of 240 lipid sum compositions from five phospholipid classes could be monitored in MS2 (HR-SRM/MS) while there was no limitation in the number of analytes in MS1 (HR-SIM/MS).

Hydraulic study of a non-steady horizontal sub-surface flow constructed wetland during start-up.

This paper describes the hydraulic performance of a start-up, pilot-scale, horizontal sub-surface flow constructed wetland (CW), located outdoors at the Helmholtz UFZ, Leipzig. This paper aims to investigate the impact of the method of hydraulic calculation in a pilot-scale system. Impulse-response tracer tests were conducted at multiple depths and locations throughout the system and the uranine concentration was measured using a fluorometer.