The potential of a population register for addressing health inequities: an observational study using data linkage to improve breast cancer screening enrolment and participation in Indigenous Māori women in Aotearoa New Zealand.

Background: Breast cancer screening in Aotearoa New Zealand (NZ) still has persistent inequitable coverage by ethnicity, especially for Indigenous Māori women. This project aimed to undertake systematic data linkage to identify and invite eligible Māori women to participate in breast screening.

Methods: This is a cross-sectional observational study conducted in Northern New Zealand between 1/01/2020 and 30/06/2021.

Clinical Significance of Quantitative Viral Load in Patients Positive for SARS-CoV-2.

Cycle threshold (CT) refers to the number of cycles in a reverse transcriptase polymerase chain reaction (RT-PCR) assay needed to amplify viral RNA and can be used to indicate viral load. CT is inversely related to viral load, where lower CT values indicate higher viral levels. Data suggest lower CT scores are associated with worse outcomes in COVID; however, quantitative CT scores are not typically reported to patients.

The Prevalence and Management of Atrial Fibrillation in New Zealand Māori Detected through an Abdominal Aortic Aneurysm Screening Program.

Background: Atrial fibrillation (AF) screening was incorporated into an abdominal aortic aneurysm screening (AAA) program for New Zealand (NZ) Māori.

Methods: AF screening was performed as an adjunct to AAA screening of Māori men aged 60-74 years and women aged 65-74 years registered with primary health care practices in Auckland, NZ. Pre-existing AF was determined through coded diagnoses or medications in the participant's primary care record.

Retrospective survey of colposcopy experience for wāhine Māori across two time periods (2016 and 2021) in Waitematā and Auckland districts, New Zealand.

Aims: To examine wāhine Māori experiences of colposcopy services in New Zealand based on surveys conducted in 2016 and 2021.

Methods: The surveys included a total of 201 wāhine Māori who had attended one of the three colposcopy clinics in the Waitematā and Auckland districts. Participants were retrospectively surveyed about their experience via telephone using a pre-tested questionnaire.

TopoRoot: a method for computing hierarchy and fine-grained traits of maize roots from 3D imaging.

Background: 3D imaging, such as X-ray CT and MRI, has been widely deployed to study plant root structures. Many computational tools exist to extract coarse-grained features from 3D root images, such as total volume, root number and total root length. However, methods that can accurately and efficiently compute fine-grained root traits, such as root number and geometry at each hierarchy level, are still lacking.

Planning and delivery of intensity modulated bolus electron conformal therapy.

Purpose: Bolus electron conformal therapy (BECT) is a clinically useful, well-documented, and available technology. The addition of intensity modulation (IM) to BECT reduces volumes of high dose and dose spread in the planning target volume (PTV). This paper demonstrates new techniques for a process that should be suitable for planning and delivering IM-BECT using passive radiotherapy intensity modulation for electrons (PRIME) devices.

Useful island block geometries of a passive intensity modulator used for intensity-modulated bolus electron conformal therapy.

Purpose: This project determined the range of island block geometric configurations useful for the clinical utilization of intensity-modulated bolus electron conformal therapy (IM-BECT).

Methods: Multiple half-beam island block geometries were studied for seven electron energies 7-20 MeV at 100 and 103 cm source-to-surface distance (SSD). We studied relative fluence distributions at 0.

Introduction to passive electron intensity modulation.

This work introduces a new technology for electron intensity modulation, which uses small area island blocks within the collimating aperture and small area island apertures in the collimating insert. Due to multiple Coulomb scattering, electrons contribute dose under island blocks and lateral to island apertures. By selecting appropriate lateral positions and diameters of a set of island blocks and island apertures, for example, a hexagonal grid with variable diameter circular island blocks, intensity modulated beams can be produced for appropriate air gaps between the intensity modulator (position of collimating insert) and the patient.

Ten Years toward Equity: Preliminary Results from a Follow-Up Case Study of Academic Computing Culture.

Just over 10 years ago, we conducted a culture study of the Computer Science Department at the flagship University of Illinois at Urbana-Champaign, one of the top five computing departments in the country. The study found that while the department placed an emphasis on research, it did so in a way that, in conjunction with a lack of communication and transparency, devalued teaching and mentoring, and negatively impacted the professional development, education, and sense of belonging of the students. As one part of a multi-phase case study spanning over a decade, this manuscript presents preliminary findings from our latest work at the university.

Round robin test on quantification of amyloid-β 1-42 in cerebrospinal fluid by mass spectrometry.

Introduction: Cerebrospinal fluid (CSF) amyloid-β 1-42 (Aβ42) is an important biomarker for Alzheimer's disease, both in diagnostics and to monitor disease-modifying therapies. However, there is a great need for standardization of methods used for quantification. To overcome problems associated with immunoassays, liquid chromatography-tandem mass spectrometry (LC-MS/MS) has emerged as a critical orthogonal alternative.

Practical applications of integrated microfluidics for peptide quantification.

Background: Increased pressure to obtain more, higher sensitivity data from less sample is especially critical for large peptides, whose already optimized LC-MS methods are heavily challenged by traditional ligand-binding assays.

Results: Critical bioanalytical assays were adapted to integrated microscale LC to reduce sample volumes while increasing sensitivity. Assays for teriparatide, glucagon and human insulin and five analogs were transferred from 2.

An ultrasensitive nano UHPLC-ESI-MS/MS method for the quantification of three neuromedin-like peptides in microdialysates.

Aim: An ultrasensitive nano UHPLC-ESI-MS/MS method is developed to simultaneously monitor three low-concentration neuromedin-like peptides in microdialysates.

Results: Peptide preconcentration and sample desalting is performed online on a trap column. A shallow gradient slope at 300 nl/min on the analytical column maintained at 35°C, followed by two saw-tooth column wash cycles, results in the highest sensitivity and the lowest carryover.

Bioanalysis Zone: overcoming matrix effects Q&A.

Experts Erin Chambers (Waters Corporation), John Kagel (University of North Carolina) and David Bell (Sigma-Aldrich) took part in a recent live panel discussion on overcoming matrix effects as part of the Bioanalysis Zone spotlight on the topic. Here they answer questions from our readers, which were submitted during the discussion and as part of our survey on the topic.

Improved sensitivity of the nano ultra-high performance liquid chromatography-tandem mass spectrometric analysis of low-concentrated neuropeptides by reducing aspecific adsorption and optimizing the injection solvent.

Obtaining maximal sensitivity of nano UHPLC-MS/MS methods is primordial to quantify picomolar concentrations of neuropeptides in microdialysis samples. Since aspecific adsorption of peptides to Eppendorf tubes, pipette tips and UHPLC vials is detrimental for method sensitivity, a strategy is presented to reduce adsorption of these peptides during standard preparation. Within this respect, all procedural steps from dissolution of the lyophilized powder until the injection of the sample onto the system are investigated.

Matrix effects in metabolite quantification for MIST assessment: the impact of phospholipid removal and HPLC column particle size.

Background: This Research article investigates the impact of phospholipid removal and high-performance liquid chromatography column particle size on the accuracy of determining the relative abundance of human metabolites using mass spectrometry peak areas in the context of assessing metabolite abundance for Metabolites in Safety Testing assessment. RESULTS/METHODOLOGY: Plasma samples spiked with 20 compounds, representing ten pairs of drugs and metabolites, were prepared using phospholipid removal plates (Ostro™) or standard protein precipitation techniques and analyzed by liquid chromatography-tandem mass spectrometry using high-performance liquid chromatography columns containing either 2.5 or 3.

Multidimensional LC-MS/MS enables simultaneous quantification of intact human insulin and five recombinant analogs in human plasma.

This work provides a multidimensional method for the simultaneous, direct quantification of intact human insulin and five insulin analogs in human plasma. This investigation solves both the selectivity and sensitivity problems encountered for accurate quantification of insulins in plasma since the former is not possible with conventional assays and the latter with conventional LC-MS/MS. The method uses a mixed-mode SPE and a multidimensional LC method including a solid-core particle column containing an anion exchange stationary phase.

Systematic development of an UPLC-MS/MS method for the determination of tricyclic antidepressants in human urine.

Tricyclic antidepressants have been prescribed for the treatment of depression and other disorders since their discovery in the 1950s but have been replaced in recent decades by newer drugs with more favorable side effect profiles. However, for some patients and conditions, tricyclic antidepressants remain the drug of choice. A fast, sensitive, and robust UPLC-MS/MS method for the monitoring of amitriptyline, nortriptyline, imipramine, doxepin, and desipramine in human urine has been developed using a pre-defined and systematic method development approach.

High sensitivity LC-MS/MS method for direct quantification of human parathyroid 1-34 (teriparatide) in human plasma.

Teriparatide, the 1-34 fragment of human parathyroid hormone, is used to treat osteoporosis patients with a high risk of fracture by stimulating new bone formation. Routinely teriparatide is quantified using radioimmunoassay however the LC-MS/MS described here has the potential to achieve greater accuracy and precision, higher specificity, and is readily implemented in routine bioanalytical laboratories. Hence a complete method combining effective sample prep with appropriate LC separation and selected reaction monitoring (SRM) MS detection was developed to selectively separate teriparatide from closely related endogenous peptides and to reduce interferences.

Development of a fast method for direct analysis of intact synthetic insulins in human plasma: the large peptide challenge.

Background: Intact insulins are difficult to analyze by LC-MS/MS due to nonspecific binding and poor sensitivity, solubility and fragmentation. This work aims to provide a simpler, faster LC-MS method and focuses on solving the above issues.

Results: A novel charged-surface chromatographic column produced peak widths for insulin that were significantly narrower than traditional C18 columns when using formic acid as mobile phase.

Hydrophilic interaction chromatography (HILIC) for LC-MS/MS analysis of monoamine neurotransmitters.

Background: Hydrophilic interaction chromatography (HILIC) is becoming an increasingly popular alternative to traditional reversed-phase chromatography for the analysis of polar compounds. The ability to retain the most polar compounds in HILIC makes it attractive for the analysis of certain large groups of compounds, such as monoamines, which are inherently very polar.

Results: This paper details the development of a HILIC LC-MS/MS method for the analysis of monoamine neurotransmitters.

Challenges in developing an ultra-sensitive bioanalytical method for ethinylestradiol in human plasma.

Background: Ethinylestradiol (EE) is the active component in most birth control products. It is especially difficult to analyze due to the presence of many closely related endogenous steroids. Endogenous components can coelute with EE making selective extraction and chromatographic separation challenging.

Quantitation of amyloid beta peptides Aβ(1-38), Aβ(1-40), and Aβ(1-42) in human cerebrospinal fluid by ultra-performance liquid chromatography-tandem mass spectrometry.

Critical events in Alzheimer's disease (AD) involve an imbalance between the production and clearance of amyloid beta (Aβ) peptides from the brain. Current methods for Aβ quantitation rely heavily on immuno-based techniques. However, these assays require highly specific antibodies and reagents that are time-consuming and expensive to develop.

Performance of plasma free metanephrines measured by liquid chromatography-tandem mass spectrometry in the diagnosis of pheochromocytoma.

Background: Plasma free metanephrines have proved a highly sensitive biochemical test for the diagnosis of pheochromocytoma. We have developed and validated a simple, LC-MS/MS method to determine plasma metanephrines and compared the diagnostic efficacy of the method with an enzyme immunoassay procedure in 151 patients, 38 with histologically confirmed pheochromocytoma.

Methods: Off-line solid phase extraction in a 96-well plate format was used to isolate metanephrines from 100-microL of plasma, followed by rapid separation with hydrophilic interaction chromatography.