miRNA-based electrochemical biosensors for ovarian cancer.

Ovarian cancer, a prevalent and deadly cancer among women, presents a significant challenge for early detection due to its heterogeneous nature. MicroRNAs, short non-coding regulatory RNA fragments, play a role in various cellular processes. Aberrant expression of these microRNAs has been observed in the carcinogenesis-related processes of many cancer types. Numerous studies highlight the critical role of microRNAs in the initiation and progression of ovarian cancer. Given their clinical importance and predictive value, there has been considerable interest in developing simple, prompt, and sensitive miRNA biosensor strategies. Among these, electrochemical sensors have demonstrated advantageous characteristics such as simplicity, sensitivity, low cost, and scalability. These microRNA-based electrochemical biosensors are valuable tools for early detection and point-of-care applications. This article discusses the potential role of microRNAs in ovarian cancer and recent advances in the development of electrochemical biosensors for miRNA detection in ovarian cancer samples.

Amplification-free nucleic acids detection with next-generation CRISPR/dx systems.

CRISPR-based diagnostics (CRISPR/Dx) have revolutionized the field of molecular diagnostics. It enables home self-test, field-deployable, and point-of-care testing (POCT). Despite the great potential of CRISPR/Dx in diagnoses of biologically complex diseases, preamplification of the template often is required for the sensitive detection of low-abundance nucleic acids. Various amplification-free CRISPR/Dx systems were recently developed to enhance signal detection at sufficient sensitivity. Broadly, these amplification-free CRISPR/Dx systems are classified into five groups depending on the signal enhancement strategies employed: CRISPR/Cas12a and/or CRISPR/Cas13a are integrated with: (1) other catalytic enzymes (Cas14a, Csm6, Argonaute, duplex-specific nuclease, nanozyme, or T7 exonuclease), (2) rational-designed oligonucleotides (multivalent aptamer, tetrahedral DNA framework, RNA G-quadruplexes, DNA roller machine, switchable-caged guide RNA, hybrid locked RNA/DNA probe, hybridized cascade probe, or "U" rich stem-loop RNA), (3) nanomaterials (nanophotonic structure, gold nanoparticle, micromotor, or microbeads), (4) electrochemical and piezoelectric plate biosensors (SERS nanoprobes, graphene field-effect transistor, redox probe, or primer exchange reaction), or (5) cutting-edge detection technology platforms (digital bioanalysis, droplet microfluidic, smartphone camera, or single nanoparticle counting). Herein, we critically discuss the advances, pitfalls and future perspectives for these amplification-free CRISPR/Dx systems in nucleic acids detection. The continued refinement of these CRISPR/Dx systems will pave the road for rapid, cost-effective, ultrasensitive, and ultraspecific on-site detection without resorting to target amplification, with the ultimate goal of establishing CRISPR/Dx as the paragon of diagnostics.

Diagnostic Strategies in the Era of Monkeypox Resurgence: A Comprehensive Analysis.

The resurgence of monkeypox (Mpox), an orthopoxvirus infection closely related to smallpox, presents a significant global health challenge. This study presents a comprehensive overview of Mpox, focusing on its clinical manifestations, diagnostic strategies, and testing methodologies. A thorough review of the literature and available data on Mpox, emphasizing diagnostic assays, clinical indicators, and laboratory testing, constitutes the core of this analysis. The study involves insights from Mpox patients and healthcare professionals engaged in its diagnosis and management. Contextualizing the research within the global spread of Mpox addresses the complexities associated with the diagnosis of the disease. The findings illuminate diverse Mpox diagnostic techniques, encompassing viral culture, immunological methods, serology, quantitative polymerase chain reaction (qPCR), electron microscopy, and advanced technologies such as artificial intelligence (AI) and the GeneXpert system. qPCR is highlighted as the benchmark for MPXV detection and quantification. These diagnostic advancements have significantly enhanced the precision and efficiency of Mpox diagnosis, facilitating prompt identification and treatment of infected individuals. The study underscores the critical importance of accurate and timely diagnosis, proper handling and transportation of clinical specimens, and the imperative for point-of-care (POC) testing to control the global spread of Mpox.

Impact of Hepatitis B Virus Point-of-care DNA Viral Load Testing Compared With Laboratory-based Standard-of-care Approaches on Uptake of HBV Viral Load Testing, Treatment, and Turnaround Times: A Systematic Review and Meta-analysis.

Background: Point-of-care (PoC) hepatitis B virus (HBV) DNA viral load (VL) assays represent an alternative to laboratory-based standard-of-care (SoC) VL assays to accelerate diagnosis and treatment. We evaluated the impact of using PoC versus SoC approaches on the uptake of VL testing, treatment, and turnaround times from testing to treatment across the HBV care cascade. Methods: We searched 5 databases, 6 conference websites, and contacted manufacturers for unpublished reports, for articles with or without a comparator (SoC VL testing), and had data on the uptake of VL testing, treatment, or turnaround times between hepatitis B surface antigen (HBsAg) testing, VL testing, and treatment in the cascade. We performed a random-effects meta-analysis on rates of VL testing and treatment initiation. Results: Six studies, composing 9 arms, were included. Three PoC arms reported less than 1 day between screening for HBsAg positivity and VL testing, and the other one (2 arms) reported it between 7 and 11 days. Five arms reported the time to available VL test results (<1 day). Three studies reported 1-8 days between VL testing results and treatment initiation. Two studies reported the turnaround times between a positive HBsAg screening and treatment initiation (the same day and 27 days). Overall, 84.1% of those with HBsAg positivity were tested for DNA VL and 88.3% of eligible people initiated treatment. Conclusions: HBV PoC DNA testing appears to be associated with a turnaround time of <1 day for receipt of VL results and appears associated with high rates of DNA testing and initiation of treatment among those eligible. Clinical Trials Registration: PROSPERO CRD42023398440.

Esophageal oxyhemoglobin saturation as a resuscitative metric in hemorrhagic shock.

Background: Mixed venous saturation (SvO2) is considered the gold standard to assess the adequacy of tissue oxygen delivery (DO2) in shock states. However, SvO2 monitoring is challenging as it requires an invasive catheter and frequent blood sampling. Non-invasive methods, including near-infrared spectroscopy, have demonstrated low sensitivity to tissue dysoxia. Methods: We fabricated a new device that uses resonance Raman spectroscopy (RRS) to quantify oxyhemoglobin saturation (ShbO2) in the esophagus (eShbO2), tongue (tShbO2), and liver (hShbO2). In two rat models of hemorrhagic shock, we quantified (1) The correlation of RRS-measured ShbO2 to SvO2 during progressive hemorrhage (n=20) and (2) The value of these metrics to predict near-term mortality in fixed, severe hemorrhage (mean blood pressure =25 mm Hg; n=18). Results: In model 1, eShbO2 (r=0.705, p<0.0001) and tShbO2 (r=0.724, p<0.0001) correlated well with SvO2 and with serum lactic acid (eShbO2-lactate r=0.708, p<0.0001; tShbO2-lactate r=0.830, p<0.0001). hShbO2 correlated poorly with both SvO2 and lactic acid. Using time-matched ShbO2-SvO2 pairs, the performance of ShbO2 to detect severe tissue hypoxia (SvO2<20%) was excellent (AUC 0.843 for eShbO2, 0.879 for tShbO2). In model 2, eShbO2 showed a maximized threshold of 40% with 83% of animals dying within 45 minutes of this cut-off, demonstrating accuracy as a monitoring device. This was similar for tShbO2, with a threshold of 50%, predicting death within 45 minutes in 76% of animals. ShbO2 showed superior sensitivity to invasive monitoring parameters, including MABP<30 mm Hg (sensitivity 59%), pulse pressure<15 mm Hg (sensitivity 50%), and heart rate>220 bpm (sensitivity 39%, p=0.004). Conclusions: eShbO2 represents a new paradigm to assess the adequacy of DO2 to a tissue. It constitutes a promising monitoring method to evaluate tissue oxygen saturation in real time and non-invasively, correlating with SvO2 and time to death. Level of evidence: Level III, therapeutic/care management.

An intelligent fluorescence sensing platform based on entropy-driven toehold-mediated strand displacement cycle reaction for point-of-care testing of miRNA.

BACKGROUND: MicroRNA (miRNA) has gradually become an emerging biomarker for early diagnosis and prognosis of various diseases due to its specific gene expression and high stability. With the development of molecular diagnosis and point-of-care testing (POCT) technology, developing simple, fast, sensitive, efficient, and low-cost miRNA sensors is of great significance for clinical applications and emergency rapid diagnosis. At present, entropy-driven toehold mediated chain displacement reaction, as a promising enzyme free isothermal amplification technique, is an important tool for ultra-sensitive biosensing applications. RESULTS: In this study, we used gold nanoparticles (AuNPs) as carriers and quenchers, modified them using self-assembled triple chain composite substrates AuNPs@A@B1/B2, and used dual reporter molecules for cascade cyclic amplification to amplify fluorescence signals, which proposed a fluorescent biosensor based on this reaction and build an intelligent fluorescence sensing platform for rapid detection of miRNA. We designed a highly specific self-programmable sensor using the acute ischemic stroke (AIS) biomarker miRNA-125a-5p as a sample, and achieved sensitive detection of miRNA in the range of 0.01 µM∼10 µ M under optimal conditions. It broke through the traditional detection limitations of weak signals and liberated the fluorescence detection environment. SIGNIFICANCE: In summary, this creative miRNA biosensor combined with POCT has demonstrated extraordinary detection potential, broad application prospects in the early diagnosis and prognosis monitoring of AIS, provides a novel miRNA universal detection strategy for the fields of biological and life sciences.

Customizable OpenGUS immunoassay: A homogeneous detection system using ß-glucuronidase switch and label-free antibody.

We developed a customizable OpenGUS immunoassay that enables rapid and sensitive detection of analytes without requiring antibody modification. This immunoassay employs label-free whole antibodies, an antibody-binding Z domain (ZD) derived from Staphylococcal protein A, and a ß-glucuronidase (GUS) switch mutant, allowing for easy replacement of antibodies to tailor the immunoassays for various targeted antigens. The working principle is that the OpenGUS probe, the fusion protein of ZD and a GUS switch, converts the antibody-antigen interaction into GUS activation in a one-pot reaction. To enhance the signal-to-background ratio of the immunoassay, a GUS switch mutant that exhibits reduced background activation was developed by screening several additional mutations at the diagonal interface residue H514. Moreover, we optimized the composition of the reaction buffer, including organic solvents, salt, and surfactant. Under optimal conditions, we customized OpenGUS immunoassays for Cry j 1, human C-reactive protein, and human lactoferrin, achieving around 10-20-fold maximum fluorescence (15 min) or colorimetric (2 h) responses with picomolar to low nanomolar level detection limit, simply by using commercially available IgGs. Additionally, the three analytes were successfully detected in complex matrices similar to those used in practical applications. We believe that this customizable OpenGUS immunoassay will pave the way for the prompt development of rapid and sensitive homogeneous immunoassays for point-of-care diagnostics, high-throughput testing, and onsite environmental assessments.

Label-Free Exosome Analysis by Surface-Enhanced Raman Scattering Spectroscopy with Laser-Ablated Silver Nanoparticle Substrate.

Early diagnostics of breast cancer is crucial to reduce the risk of cancer metastasis and late relapse. Exosome, which contains distinct information of its origin, can be the target object as a liquid biopsy. However, its low sensitivity and inadequate diagnostic tools interfere with the point-of-care testing (POCT) of the exosome. Recently, Surface-enhanced Raman Scattering (SERS) spectroscopy, which amplifies the Raman scattering, has been proved as a promising tool for exosome detection. However, the fabrication process of SERS probe or substrate is still inefficient and far from large-scale production. This study proposes rapid and label-free detection of breast cancer-derived exosomes by statistical analysis of SERS spectra using silver-nanoparticle-based SERS substrate fabricated by selective laser ablation and melting (SLAM). Employing silver nanowires and optimizing laser process parameters enable rapid and low-energy fabrication of SERS substrate. The functionalities including sensitivity, reproducibility, stability, and renewability are evaluated using rhodamine 6G as a probe molecule. Then, the feasibility of POCT is examined by the statistical analysis of SERS spectra of exosomes from malignant breast cancer cells and non-tumorigenic breast epithelial cells. The presented framework is anticipated to be utilized in other biomedical applications, facilitating cost-effective and large-scale production performance.

Biomarkers of Hemodynamic Congestion in Heart Failure.

PURPOSE OF REVIEW: The purpose of this review is to describe the evidence behind various blood and imaging-based biomarkers that can improve the identification of congestion when not clearly evident on routine examination. RECENT FINDINGS: The natriuretic peptides (NPs) BNP and NT-proBNP have been shown to closely correlate with intra-cardiac filling pressures, both at baseline and when trended following improvement in congestion. Additionally, NPs rise well before clinical congestion is apparent so can be used as a tool to help identify subclinical HF decompensation. Additional serum-based biomarkers including MR-proANP and CA-125 can be helpful in assisting with diagnostic certainty when BNP or NT-proBNP are in the "grey zone" or when factors are present which may confound NP levels. Additionally, the emerging use of ultrasound techniques may enhance our ability to fine-tune the assessment and treatment of congestion. Biomarkers, including the blood-based natriuretic peptides and markers on bedside point of care ultrasound, can be used as non-invasive indices of hemodynamic congestion. These biomarkers are particularly valuable to incorporate when the degree of a patient's congestion is not apparent on clinical exam, and they can provide important prognostic information and help guide clinical management.

Diagnostic accuracy of ultrasonography in acute lateral ankle ligament injury: A systematic review and meta-analysis.

BACKGROUND: The gold standard diagnostic method for acute lateral ankle ligament sprain is magnetic resonance imaging (MRI). However, it is hardly accessible and is time-consuming. Therefore, additional diagnostic methods are warranted. Point-of-care ultrasound, on the other hand, is inexpensive, widely available, time-efficient testing method. PURPOSE: Therefore, the aim of this meta-analysis is to determine the diagnostic accuracy of ultrasound for acute ankle ligament injuries compared to MRI. METHODS: In our systematic review and meta-analysis, we followed the recommendations of the Cochrane Handbook. We searched the following databases from inception to March 31, 2022: Medline (PubMed), EMBASE, and Cochrane Library. Eligible studies investigated the diagnostic accuracy of US compared to MRI for diagnosing acute lateral ankle ligament injuries. Finally, we calculated pooled sensitivity and specificity with a 95 % confidence interval (CI). RESULTS: Eight studies met our eligibility criteria, involving 434 patients. For anterior tibiofibular ligament (ATFL) injury, the summary sensitivity and specificity were Se = 0.97 (CI: 0.89-0.99) and Sp = 0.93 (CI: 0.84-0.97). For calcaneofibular ligament (CFL) injury, the summary sensitivity and specificity were Se.: Se = 0.81 (CI: 0.58-0.93) and Sp = 0.92 [0,81;0,97]. In addition, subgroup analysis based on US performed by different types of investigators was comparable between each other (radiologist group Se = 0.98, CI: 0.24-1, and Sp = 0.91, CI: 0.74-0.97, and the orthopedic/ emergency department group Se = 0.96, CI: 0-1, and Sp = 0.97, CI: 0-1). CONCLUSION: Ultrasound showed high diagnostic accuracy for acute lateral ankle ligament injury, irrespective of the investigator. Therefore, based on the current available data, it could be used in primary diagnostics of acute lateral ankle ligament injury.

Commercial Strip-Inspired One-Pot CRISPR-Based Chip for Multiplexed Detection of Respiratory Viruses.

The absence of sensitive, multiplexed, and point-of-care assays poses a critical obstacle in promptly responding to emerging human respiratory virus (HRV) pandemics. Herein, RECOGNIZER (re-building commercial pregnancy strips via large-size nanoflowers), an innovative one-pot CRISPR assay, is presented that employs commercially available strips to identify several types of HRVs. The superiority of the RECOGNIZER assay mainly relies on two aspects: (i) DNA nanoflowers possessing a high surface-to-volume ratio and well-defined surface allow for a considerable probe loading density and minimized non-specific interaction, achieving an impressive signal-to-noise proportion exceeding tenfold at 1 nM target. (ii) The design of the one-pot reaction, multi-channel chip, and custom-made app enables the rapid, sample-to-answer, and multiplexed analysis of four HRVs in 25 min. This assay demonstrates a sensitivity of 5.42 pM for synthetic SARS-CoV-2 RNA and 10 copies µL-1 for SARS-CoV-2 plasmids after pre-amplification. Finally, the proposed approach indicated 100% accuracy in 50 clinical swab samples, demonstrating the robust performance in distinguishing SARS-CoV-2 from other HRVs. The versatility and scalability of RECOGNIZER renders it a user-friendly platform for virus infection monitoring, offering significant potential for improving pandemic response efforts.

Evaluation of a point-of-care multiplex immunochromatographic assay for the diagnosis of typhoid: results from a retrospective diagnostic accuracy study.

There is a clear medical need for an accurate diagnostic test for typhoid that can be performed at point of care. Two antigens (lipopolysaccharide [LPS] and hemolysin E [HlyE]) have recently been identified that can distinguish typhoid from other bacterial infections. Here, we present the results of a diagnostic accuracy study of the Dual Path Platform (DPP) Typhoid assay (Chembio) that detects IgA to both LPS and HlyE using blood culture as the reference standard. This was a retrospective, observational, laboratory study conducted at the Aga Khan University research laboratory, Pakistan, to evaluate the sensitivity and specificity of the DPP Typhoid assay, using archived frozen serum samples collected during a previous typhoid diagnostic accuracy study (NCT04801602). The sensitivity, specificity, and accuracy (area under the receptor operating characteristics curve [AUC]) were then assessed using the manufacturer's and Youden's optimal thresholds. In total, 385 samples were included in the analysis. Using the manufacturer's thresholds, the sensitivity, specificity, and AUC were 97.8% (95% confidence interval [CI] 94.6-99.2), 65.3% (95% CI 58.5-71.6), and 81.5% (95% CI 75.5-85.3), respectively. At Youden's optimal threshold, the overall sensitivity of the DPP Typhoid assay was 89.7% and the specificity was 82.2%. In latent class modeling compared with other nine rapid diagnostic tests evaluated from the same cohort sample, the DPP Typhoid assay demonstrated the highest balanced accuracy (89.2%). The DPP Typhoid assay demonstrated a high diagnostic accuracy for typhoid fever. However, further adjustment to new thresholds is recommended to enhance its performance capabilities. IMPORTANCE: Currently available diagnostic tests for typhoid have several limitations, including low sensitivity and specificity. Dual Path Platform Typhoid assay is a multiplex rapid test that detects IgA antibodies to lipopolysaccharide and hemolysin E antigen. It is considered to have high sensitivity and specificity, and its results were found to be highly correlated with ELISA results. However, very few studies have been conducted to evaluate this test and limited information about the accuracy of this test is present. Hence, this study evaluated the new typhoid test.

Impact of regression modeling on the assessment and harmonization of a point-of-care analyzer and commercial laboratory analyzer for feline plasma biochemistry testing.

BACKGROUND: Regression describes the relationship of results from two analyzers, and the generated equation can be used to harmonize results. Point-of-care (POC) analyzers cannot be calibrated by the end user, so regression offers an opportunity for calculated harmonization. Harmonization (uniformity) of laboratory results facilitates the use of common reference intervals and medical decision thresholds. OBJECTIVE: Our aims were to characterize the relationship of results for multiple biochemistry analytes on a POC and a commercial laboratory analyzer (CL) with three regression techniques and to use regression equations to harmonize the POC results with those of the CL. Harmonized results were assessed by recognized quality goals. We used harmonized results to assess the regression techniques. METHODS: After analyzer imprecision assessments, paired clinical samples were assessed with one dataset to calculate regression parameters that were applied to a second dataset. Three regression techniques were performed, and each was used to harmonize the POC results with those from the CL. POC results were assessed for bias and the number of results reaching quality goals before and after harmonization. RESULTS: All regression techniques could be used to harmonize most analytes so that 95% of results were within ASVCP TEa guidelines. Harmonization could be further improved with alternate regression techniques or exclusions. CONCLUSIONS: Regression offers a means to harmonize POC and CL analyzers. Further work is needed to assess how few samples can reliably be used and to assess likely species differences. No regression technique reliably describes the relationship between methods when correlation is poor.

Appropriateness of respiratory physiotherapy positioning for acute lobar collapse.

BACKGROUND: Positioning is an important physiotherapy treatment modality for the management of aeration loss associated with acute lobar atelectasis (ALA). Physiotherapists typically rely on lung auscultation and interpretation of chest x-ray (CXR) to inform treatment selection. These tools lack diagnostic accuracy, which could limit the ability of a physiotherapist to locate ALA and select an appropriate treatment position. OBJECTIVES: The objectives of this study were to determine the number of clinical physiotherapist treatment positions found to be in agreement with lung ultrasound (LUS)-identified aeration loss and to determine the diagnostic accuracy of CXR and lung auscultation against LUS as the reference standard for locating aeration loss in mechanically ventilated patients with ALA. METHODS: A prospective cohort study was conducted in a tertiary teaching hospital in Sydney. Mechanically ventilated adult patients in critical care with ALA were included. Physiotherapist-selected positions were compared against location of aeration loss based on LUS results to determine appropriateness. Location of aeration loss as identified by CXR results and lung auscultation was compared against LUS as the reference standard to determine diagnostic accuracy. RESULTS: Forty-three participants were included in this study. Four out of 43 patients (9.3%) were positioned appropriately. The rate of true positives for CXR and auscultation in locating aeration loss were highest in the lower lobes. Lung auscultation had higher sensitivities (16.7%-97.4%) than CXR (0%-59.5%) in a majority of lobes when detecting location of aeration loss. CXR had higher specificities (16.7%-100%) than lung auscultation (0%-64.9%) in a majority of lobes when detecting location of aeration loss. CONCLUSIONS: Physiotherapists did not deliver appropriate positioning in a majority of cases. Overall, the diagnostic accuracy of lung auscultation and CXR in detecting location of ALA was low. Correctly locating lung aeration loss is imperative to ensure appropriate respiratory physiotherapy positions are selected. Physiotherapists should consider additional assessment tools such as LUS to increase their diagnostic ability.

An Injection Molded SlipChip with Self-Sampling for Integrated Point-of-Care Testing of Human Papilloma Virus.

High-risk human papillomavirus (HPV) screening is crucial for cervical cancer prevention. However, laboratory-based nucleic acid amplification tests (NAATs) require costly equipment, designated lab space, and skilled personnel. Additionally, cervical swabs collected by healthcare professionals can be inconvenient, uncomfortable, and reduce privacy, limiting broader application and patient compliance. A SlipChip-based Integrated Point-of-Care (SIPOC) system featuring an injection-molded SlipChip is presented with preloaded reagents for nucleic acid extraction and a portable four-channel real-time quantitative PCR instrument for detection. This system incorporates a self-sampling method that allows participants to collect their own vaginal swabs, with the ß-Globin gene as a control. After testing 130 participants for HPV-16 and HPV-18, 97.7% of the self-collected samples are valid. Among valid samples, 25 tested positive for HPV-16 and 9 for HPV-18. Compared to Roche's standard HPV PCR test, the SIPOC system shows 100% positive predictive value (PPV) for both HPV-16 and HPV-18 and negative predictive values (NPVs) of 99.0% and 99.1%, respectively. This system is promising for HPV screening in resource-limited settings and adaptable for other point-of-care NAAT applications, including home testing.

Development of a µPAD for the point-of-care testing of serum glutamic oxaloacetic transaminase (SGOT).

A wax-patterned paper analytical device (µPAD) has been developed for point-of-care colourimetric testing of serum glutamic oxaloacetic transaminase (SGOT). The detection method was based on the transamination reaction of aspartate with α-ketoglutarate, leading to the formation of oxaloacetate which reacts with the reagent Fast Blue BB salt and forms a cavern pink colour. The intensity of the cavern pink colour grows as the concentration of SGOT increases. UV-visible spectroscopy was utilized to optimize reaction conditions, and the optimized reagents were dropped onto the wax-patterned paper. The coloured PADs, after the addition of SGOT, have been photographed, and a colour band has been generated to correlate the SGOT concentration visually. The images were used to calculate the intensity values using ImageJ software, which inturn was used to calculate the SGOT concentration. The PADs were also tested with serum samples, and SGOT spiked serum samples. The PAD could detect the SGOT concentration ranging from 5 to 200 U/L. The analysis yielded highly accurate results with less than 6% relative error compared to the clinical sample. This colourimetric test demonstrated exceptional selectivity in the presence of other biomolecules in the blood serum, with a detection limit of 2.77 U/L and a limit of quantification of 9.25 U/L. Additionally, a plasma separation membrane was integrated with the PAD to directly test SGOT from finger-prick blood samples.

Rapid point-of-care breath test predicts breast cancer and abnormal mammograms in symptomatic women.

Previous studies have reported volatile organic compounds (VOCs) in the breath as biomarkers of breast cancer. These biomarkers may be derived from cancer-associated fibroblasts, in which oxidative stress degrades polyunsaturated fatty acids to volatile alkanes and methylated alkane derivatives that are excreted in the breath. We evaluated a rapid point-of-care test for breath VOC biomarkers as predictors of breast cancer and abnormal mammograms. We studied 593 women aged⩾18 yr referred to three sites for mammography for a symptomatic breast-related concern (e.g. breast mass, nipple discharge). A rapid point-of-care breath testing system collected and concentrated alveolar breath VOCs on a sorbent trap and analyzed them with gas chromatography and surface acoustic wave detection in <6 min. Breath VOC chromatograms were randomly assigned to a training set or to a validation set. Monte Carlo analysis identified significant breath VOC biomarkers of breast cancer and abnormal mammograms in the training set, and these biomarkers were incorporated into a multivariate algorithm to predict disease in the validation set.Prediction of breast cancer:50 women had biopsy-proven breast cancer (invasive cancer 41, ductal non-invasive cancer 9)Unsplit data set:breath VOCs identified breast cancer with 83% accuracy (area under curve of receiver operating characteristic), 82% sensitivity and 77.1% specificity.Split data sets:training set breath VOCs identified breast cancer with 80.3% accuracy, 84% sensitivity and 74.3% specificity. Corresponding values in the validation set were 68%% accuracy, 72.4% sensitivity and 61.5% specificity.Prediction of BIRADS 4 and 5 mammograms (versus BIRADS 1, 2 and 3): unsplit data set:breath VOCs identified abnormal mammograms with 76.2% accuracy.Split data sets:breath VOCs identified abnormal mammograms with 74.2% accuracy, 73.3% sensitivity and 60% specificity. Corresponding values in the validation set were 60.5% accuracy, 64.2% sensitivity and 51% specificity. A rapid point-of-care test for breath VOC biomarkers predicted risk of breast cancer and abnormal mammograms in women with breast-related symptoms.

Performance of point-of-care glucose testing for the diagnosis of gestational diabetes in South Africa.

OBJECTIVE: Lack of accessibility to oral glucose tolerance tests (OGTTs) in South Africa means many pregnant women go without testing for gestational diabetes mellitus (GDM). This study evaluated point-of-care (POC) glucometers against the laboratory-based glucose method in pregnant women. METHODS: This was a cross-sectional study on pregnant women attending the prenatal clinic in Johannesburg who were recommended for the OGTT. OGTTs were conducted as per International Association of Diabetes and Pregnancy Study Groups (IADPSG) guidelines. Women who consented to the study donated both venous and capillary blood for laboratory-based and POC glucose measurements using seven POC glucometers: I-STAT, Xpress, LDX, VivaChek-Ino, Accu-Chek Active, StatStrip, and Codefree. By assessing sensitivity, specificity, and area under the receiver operating characteristic curve (AUC) and comparing Bland-Altman plots, the diagnostic accuracy of each glucose meter was compared with the reference method, the laboratory-based glucose method. RESULTS: Data were analyzed for 1076 pregnant women. Based on OGTT testing, 83 women had GDM (7.7%). Overall, the POC glucometers performed poorly, with sensitivity ranging from 17.6% to 87.18% and specificity ranging between 62.7% and 99.8%. The AUC ranged from 0.59 to 0.79. All POC glucometers showed moderate to poor reliability. Laboratory-based fasting plasma glucose (FPG) surpassed the POC glucometers in sensitivity, specificity, and AUC, with values of 94.0%, 100%, and 0.98, respectively. CONCLUSION: We demonstrated that laboratory-based FPG has the potential to be used as a diagnostic test for GDM and that the POC glucometers cannot replace OGTT laboratory-based measurements.

Feline friendly POCUS: how to implement it into your daily practice.

PRACTICAL RELEVANCE: Cats are great pretenders; they often hide illness until they are critical. This makes patients of this species challenging to assess and manage in the emergency setting where quick and stress-free diagnosis and treatment are necessary. Veterinary point-of-care ultrasound (POCUS) is a rapid, evidence-based, non-invasive, repeatable, cage-side ultrasonographic examination designed to answer clinically driven questions without compromising feline wellbeing. Integrating feline friendly POCUS as an extension of the physical examination to streamline diagnostic and therapeutic interventions, thereby limiting stress and improving overall patient care, is advocated by the authors of this article. EQUIPMENT: Given the multitude of ultrasound machines and probes available that are portable, meaning they can be moved around the clinic and used patient-side, it should be possible for most practitioners to integrate POCUS into daily practice. The authors' preferred equipment for feline POCUS is a microconvex probe and a portable machine with a fixed pre-set. This set-up allows the clinician to complete all POCUS (abdominal, lung and pleural space, and heart) without needing to move the patient, change probes or restrain the patient in a particular position, ultimately saving time, personnel and cost while maintaining patient comfort and safety. AIM: This review aims to serve as a valuable resource for veterinarians seeking to improve their feline patient care through the judicious utilisation of POCUS. In this article, the complex challenges posed by cats are addressed, and the different POCUS techniques, applications and clinical recommendations are discussed. EVIDENCE BASE: This review draws on the published literature, as well as the authors' own collective experience when providing recommendations.