Current Gold Standard Method Research Articles

An open-source, battery-powered, low-cost, and dual-channel pneumatic pulse generator for microfluidic cell-stretch assays

Cells in the body are regularly subjected to mechanical forces that influence their biological fate in terms of morphology, gene expression, and differentiation. The current gold standard method to replicate these effects in vitro is to culture cells on devices with elastic substrates and to impart mechanical stretch using mechanical or pneumatic pull–push methods. Microfluidic device designs offer several advantages in this context for general uniform and controlled stretching. However, the experimental setups are bulky, not user-friendly, and often involve several components that reside outside of the tissue culture incubator. Given the wide utility of mechanical stimulation in in-vitro research, our aim was to create a turn-key research tool that bioengineers can deploy in their cell-stretch assays, without having to deal with the complexity and nuances of ad hoc experimental setups. Here, we present an open-source, battery-powered, dual-channel cyclic pneumatic pulse generator box that can reside within an incubator and is compatible with custom microfluidic cell stretch devices. Our method depends on generating pressure-vacuum pulses simply using a linear miniature pneumatic air cylinder actuated using a continuous servo motor. To the best our knowledge, this is a first example of a completely battery-powered, standalone system that doesn’t have any peripherals residing out of the incubator. We provide a detailed list of different components as well as the step-by-step assembly process. We validate its performance in a cell stretch assay using a commercially available microfluidic chip. Our results show an acute stimulation of cyclic stretching over 8 h on human umbilical vein endothelial cells (HUVECs) resulted in preferential alignment of cells perpendicular to the axis of stretch.

Our journey toward implementation of digital breast tomosynthesis in breast cancer screening: the Malmö Breast Tomosynthesis Screening Project.

The purpose is to describe the Malmö Breast Tomosynthesis Screening Project from the beginning to where we are now, and thoughts for the future. In two acts, we describe the efforts made by our research group to improve breast cancer screening by introducing digital breast tomosynthesis (DBT), all the way from initial studies to a large prospective population-based screening trial and beyond. Our studies have shown that DBT has significant advantages over digital mammography (DM), the current gold standard method for breast cancer screening in Europe, in many aspects except a major one-the increased radiologist workload introduced with DBT compared with DM. It is foreseen that AI could be a viable solution to overcome this problem. We have proved that one-view DBT is a highly efficient screening approach with respect to diagnostic performance.

Research on Rapid Detection of Salmonella and Listeria monocytogenes Using Colloidal Gold Immunoassay and PCR Methods

This study used colloidal gold immunoassay strips and PCR (probe method) kit methods to detect Salmonella and Listeria monocytogenes. The accuracy and precision of the colloidal gold immunoassay strips and PCR (probe method) kit methods were validated using proficiency testing blind samples, and the consistency with the current national gold standard method was compared. The results of the two rapid detection methods were consistent with the results of the national standard method. This paper also analyzed the detection time and cost of the two rapid detection methods and the national standard method. The PCR (probe method) kit method takes less time for detection and can be used for high-throughput detection, with high sensitivity and low interference. It requires high equipment and personnel capabilities. The colloidal gold immunoassay strips method has the lowest detection cost, but its sensitivity is lower than that of the PCR method. It is easy to operate and requires low personnel and equipment requirements. Laboratories can choose the appropriate method based on their actual needs.

Comparison of the indirect immunofluorescence assay and a commercial ELISA to detect KSHV antibodies.

Kaposi's sarcoma-associated herpesvirus (KSHV) is an oncogenic virus involved in several diseases. The gold standard for KSHV sero diagnosis remains the indirect immunofluorescence assay (IFA), which is time-consuming and operator-dependent. We compared this method with an enzyme-linked immunosorbent assay (ELISA) targeting solubilized KSHV whole-genome extract among positive (n = 49, including 76% of HIV-infected patients) and negative (n = 14) control groups. We also included 14 sera with equivocal IFA results. ELISA showed better performance in detecting KSHV antibodies (McNemar's test, P = 0.0455). The sensitivity and specificity of both methods were 79% (64-89) and 100% (66-100) for the IFA, respectively, and 94% (83-99) and 100% (66-100) for ELISA, respectively. All IFA equivocal results were either negative or positive with ELISA. ELISA is more reliable and could be a good alternative for determining KSHV serological status, particularly in the context of immunocompromised patients and equivocal serology with the IFA.IMPORTANCEKaposi's sarcoma-associated herpesvirus (KSHV) sero status remains challenging because no perfect reference is available for the detection of KSHV antibodies. The current gold-standard method, the indirect immunofluorescence assay (IFA), has a very good specificity of close to 100%, but a lower sensitivity of around 80-85%, which decreases to 64-67% in immunocompromised patients. Additionally, this method is time-consuming and operator-dependent compared with new serological assays such as the enzyme-linked immunosorbent assay (ELISA). Thus, further research is still needed to improve KSHV sero diagnosis. Here, we compare the KSHV IgG ELISA kit assay (Advanced Biotechnologies Inc) with the gold-standard IFA, targeting the LANA-1 protein from latent BC-3 cell lines.

Abstract 44: Transcutaneous hydrogen sulfide measurement as a way to evaluate skin blood flow

Hydrogen sulfide (H 2 S) generated in the endothelium of small arteries has been shown to contribute to vasodilation, angiogenesis, and antioxidant properties. We have developed a non-invasive way to measure H 2 S emitted by the skin (TAGS™) and have shown that the ratio of leg:arm emitted levels correlate with severity of microvascular impairment in subjects with diabetes. This study evaluated the correlation of transdermal H 2 S ratios with the current gold standard method of evaluating leg skin blood flow, transcutaneous oxygen pressures (tcpO 2 ). TAGS™ measurements were made on the forearm and lower limbs in subjects to calculate the leg:arm ratio while tcpO 2 was recorded only from legs. Other measurements included ankle brachial index (ABI), fasting blood glucose, HbA1c, plasma lipids, blood pressure, and BMI. We observed that TAGS™ ratios correlated strongly with HbA1c (p = 0.0002) and with tcpO 2 (p = 0.0009). In addition, TAGS ratios were significantly lower in subjects with diabetes (0.69 +/- 0.18) compared to healthy controls (1.13 +/- 0.40) (p = <0.0001). These results suggest lower leg:arm ratios of transdermal H 2 S measurements are indicative of impaired microvascular function and that the TAGS™ measurements may be a simpler way than tcpO 2 to detect and monitor diminished skin blood flow that leads to PAD complications.

Fully Automated Measurement of Cobb Angles in Coronal Plane Spine Radiographs.

Background/Objectives: scoliosis is a three-dimensional structural deformity characterized by lateral and rotational curvature of the spine. The current gold-standard method to assess scoliosis is the measurement of lateral curvature of the spine using the Cobb angle in coronal plane radiographs. The interrater variability for Cobb angle measurements reaches up to 10°. The purpose of this study was to describe and assess the performance of a fully automated method for measuring Cobb angles using a commercially available artificial intelligence (AI) model trained on over 17,000 images, and investigate its interrater/intrarater agreement with a reference standard. Methods: in total, 196 AP/PA full-spine radiographs were included in this study. A reference standard was established by four radiologists, defined as the median of their Cobb angle measurements. Independently, an AI-based software, IB Lab SQUIRREL (version 1.0), also performed Cobb angle measurements on the same radiographs. Results: after comparing the readers' Cobb angle end vertebrae selection to the AI's outputs, 194 curvatures were considered valid for performance assessment, displaying an accuracy of 88.58% in end vertebrae selection. The AI's performance showed very low absolute bias, with a mean difference and standard deviation of differences from the reference standard of 0.16° ± 0.35° in the Cobb angle measurements. The ICC comparing the reference standard and the AI's measurements was 0.97. Conclusions: the AI model demonstrated good results in the determination of end vertebrae and excellent results in automated Cobb angle measurements compared to radiologists and could serve as a reliable tool in clinical practice and research.

Comparison between ultrasonography and capnography for ascertaining placement of endotracheal tube in patients undergoing general anesthesia – A prospective observational study

Background: Confirmation of the position of the endotracheal tube (ETT) is an essential step for verification of intubation. Failure to diagnose esophageal intubation may lead to fatal consequences. Capnography is the gold standard for confirmation of ETT position, but it is practically impossible to be performed in all situations. Ultrasonography (USG) or “visual stethoscope” can be used as an effective alternative for all intubators in all situations. Aims and Objectives: The study was conducted to evaluate the ultrasonography (USG) technique with respect to its efficacy to detect the proper endotracheal position of ETT compared to end-tidal capnography among patients undergoing general anesthesia; to compare the time taken by the USG technique with that of capnography for detection of proper placement of ETT; to assess the feasibility of USG to detect accidental esophageal intubation. Materials and Methods: This prospective comparative cross-sectional observational study was conducted on 68 patients. Both capnography and upper airway USG were performed immediately after intubation to confirm the ETT placement. Sensitivity, specificity, and positive and negative predictive values of upper airway USG were determined against capnography as the reference method. The time required to determine ETT placement by the two methods was found out and compared. Agreement between the methods was assessed with kappa statistics. Results: USG detected all three cases of esophageal intubation but could not detect two patients with correct tracheal intubation. Upper airway USG had a sensitivity of 96.92% (95% confidence interval [CI]: 93.54–100%), specificity of 100%, positive predictive value of 100%, and negative predictive value of 60% (95% CI: 50.4–69.6%). The Kappa value was found to be 0.735, indicating a good agreement between upper airway USG and capnography for confirmation of ETT placement. Time taken for confirmation of ETT by capnography was 21.68±2.63 s versus 11.44±1.38 s for upper airway USG (P<0.001). USG demonstrated bilateral lung sliding in 60 (88.2%) patients, unilateral lung sliding in 3 (4.4%) patients, and lung sliding was absent in 5 (7.4%) patients. Conclusion: Real-time upper airway USG is an alternative method of confirmation of ETT that is not only sensitive and accurate but is faster than the current gold standard method, capnography.

Diagnostic Performance of a Molecular Assay in Synovial Fluid Targeting Dominant Prosthetic Joint Infection Pathogens.

Prosthetic joint infection (PJI) is one of the most serious complications of joint replacement surgery among orthopedic surgeries and occurs in 1 to 2% of primary surgeries. Additionally, the cause of PJIs is mostly bacteria from the Staphylococcus species, accounting for more than 98%, while fungi cause PJIs in only 1 to 2% of cases and can be difficult to manage. The current gold-standard microbiological method of culturing synovial fluid is time-consuming and produces false-negative and -positive results. This study aimed to identify a novel, accurate, and convenient molecular diagnostic method. The DreamDX primer-hydrolysis probe set was designed for the pan-bacterial and pan-fungal detection of DNA from pathogens that cause PJIs. The sensitivity and specificity of DreamDX primer-hydrolysis probes were 88.89% (95% CI, 56.50-99.43%) and 97.62% (95% CI, 87.68-99.88%), respectively, compared with the microbiological method of culturing synovial fluid, and receiver operating characteristic (ROC) area under the curve (AUC) was 0.9974 (*** p < 0.0001). It could be concluded that the DreamDX primer-hydrolysis probes have outstanding potential as a molecular diagnostic method for identifying the causative agents of PJIs, and that host inflammatory markers are useful as adjuvants in the diagnosis of PJIs.

Expert-level sleep staging using an electrocardiography-only feed-forward neural network

Reliable classification of sleep stages is crucial in sleep medicine and neuroscience research for providing valuable insights, diagnoses, and understanding of brain states. The current gold standard method for sleep stage classification is polysomnography (PSG). Unfortunately, PSG is an expensive and cumbersome process involving numerous electrodes, often conducted in an unfamiliar clinic and annotated by a professional. Although commercial devices like smartwatches track sleep, their performance is well below PSG. To address these disadvantages, we present a feed-forward neural network that achieves gold-standard levels of agreement using only a single lead of electrocardiography (ECG) data. Specifically, the median five-stage Cohen's kappa is 0.725 on a large, diverse dataset of 5 to 90-year-old subjects. Comparisons with a comprehensive meta-analysis of between-human inter-rater agreement confirm the non-inferior performance of our model. Finally, we developed a novel loss function to align the training objective with Cohen's kappa. Our method offers an inexpensive, automated, and convenient alternative for sleep stage classification—further enhanced by a real-time scoring option. Cardiosomnography, or a sleep study conducted with ECG only, could take expert-level sleep studies outside the confines of clinics and laboratories and into realistic settings. This advancement democratizes access to high-quality sleep studies, considerably enhancing the field of sleep medicine and neuroscience. It makes less-expensive, higher-quality studies accessible to a broader community, enabling improved sleep research and more personalized, accessible sleep-related healthcare interventions.

Recording Forelimb Muscle Activity in Head-Fixed Mice with Chronically Implanted EMG Electrodes.

Powerful genetic and molecular tools available in mouse systems neuroscience research have enabled researchers to interrogate motor system function with unprecedented precision in head-fixed mice performing a variety of tasks. The small size of the mouse makes the measurement of motor output difficult, as the traditional method of electromyographic (EMG) recording of muscle activity was designed for larger animals like cats and primates. Pending commercially available EMG electrodes for mice, the current gold-standard method for recording muscle activity in mice is to make electrode sets in-house. This article describes a refinement of established procedures for hand fabrication of an electrode set, implantation of electrodes in the same surgery as headplate implantation, fixation of a connector on the headplate, and post-operative recovery care. Following recovery, millisecond-resolution EMG recordings can be obtained during head-fixed behavior for several weeks without noticeable changes in signal quality. These recordings enable precise measurement of forelimb muscle activity alongside in vivo neural recording and/or perturbation to probe mechanisms of motor control in mice.

O262: Evaluating the role and efficacy of virtual reality and simulation in teaching acute and trauma scenarios – a systematic review

Abstract Introduction Simulation allows trainees to practice skills safely and is the current gold standard method of teaching. More recently, novel methods such as virtual reality (VR) and augmented reality are being explored as possible methods of teaching. Aims To evaluate the current evidence pertaining to simulation and VR as methods of teaching in teaching acute and trauma management. Methods A systematic review was conducted using the PRISMA guidelines. Medline and Embase (via Ovid interface) were used to search for articles up to March 2023. The following MeSH terms were used: ‘(virtual reality OR VR) AND (acute surgical OR surgery OR trauma OR trauma management) AND (medical education OR education OR surgical training OR training) AND simulation’. Results A total of 3815 articles were identified. 2648 were screened upon de-duplication. 40 articles underwent full-text review; 14 were extracted. Prospective cohort studies were the most common, 43.8%. Experimental studies included a total of 436 participants, with a median sample size of 23 (IQR:14–32). 6 studies compared VR to simulation methods. Half of these articles indicated favourable conclusions towards VR training compared to standard training. A further 8 studies evaluated feasibility of VR training only – all had favourable outcomes for VR. Conclusion This review identified a range of evidence indicating that VR can be useful for training of acute surgical scenarios. VR was generally a well-received training modality although unlikely to replace simulation entirely. More robust statistical analysis in further studies is required, with investigation into the longer-term impact of VR training.

Benchmarking CRISPR-BP34 for point-of-care melioidosis detection in low-income and middle-income countries: a molecular diagnostics study

Melioidosis is a neglected but often fatal tropical disease. The disease has broad clinical manifestations, which makes diagnosis challenging and time consuming. To improve diagnosis, we aimed to evaluate the performance of the CRISPR-Cas12a system (CRISPR-BP34) to detect Burkholderia pseudomallei DNA across clinical specimens from patients suspected to have melioidosis. We conducted a prospective, observational cohort study of adult patients (aged ≥18 years) with melioidosis at Sunpasitthiprasong Hospital, a tertiary care hospital in Thailand. Participants were eligible for inclusion if they had culture-confirmed B pseudomallei infection from any clinical samples. Data were collected from patient clinical records and follow-up telephone calls. Routine clinical samples (blood, urine, respiratory secretion, pus, and other body fluids) were collected for culture. We documented time taken for diagnosis, and mortality at day 28 of follow-up. We also performed CRISPR-BP34 detection on clinical specimens collected from 330 patients with suspected melioidosis and compared its performance with the current gold-standard culture-based method. Discordant results were validated by three independent qualitative PCR tests. This study is registered with the Thai Clinical Trial Registry, TCTR20190322003. Between Oct 1, 2019, and Dec 31, 2022, 876 patients with culture-confirmed melioidosis were admitted or referred to Sunpasitthiprasong Hospital, 433 of whom were alive at diagnosis and were enrolled in this study. Median time from sample collection to diagnosis by culture was 4·0 days (IQR 3·0-5·0) among all patients with known survival status at day 28, which resulted in delayed treatment. 199 (23%) of 876 patients died before diagnosis and 114 (26%) of 433 patients in follow-up were treated, but died within 28 days of admission. To test the CRISPR-BP34 assay, we enrolled and collected clinical samples from 114 patients with melioidosis and 216patients without melioidosis between May 26 and Dec 31, 2022. Application of CRISPR-BP34 reduced the median sample-to-diagnosis time to 1·1 days (IQR 0·7-1·5) for blood samples, 2·3 h (IQR 2·3-2·4) for urine, and 3·3 h (3·1-3·4) for respiratory secretion, pus, and other body fluids. The overall sensitivity of CRISPR-BP34 was 93·0% (106 of 114 samples [95% CI 86·6-96·9]) compared with 66·7% (76 of 114 samples [57·2-75·2]) for culture. The overall specificity of CRISPR-BP34 was 96·8% (209 of 216 samples [95% CI 93·4-98·7]), compared with 100% (216 of 216 samples [98·3-100·0]) for culture. The sensitivity, specificity, speed, and window of clinical intervention offered by CRISPR-BP34 support its prospective use as a point-of-care diagnostic tool for melioidosis. Future development should be focused on scalability and cost reduction. Chiang Mai University Thailand and Wellcome Trust UK.

Photonic Si microwell architectures for rapid antifungal susceptibility determination of Candida auris.

We present the application of a photonic silicon chip-based optical sensor system for expeditious and phenotypic antifungal susceptibility testing. This label-free diagnostic assay optically monitors the growth of Candida auris at varying antifungal concentrations on a microwell-structured silicon chip in real-time, and antifungal susceptibility is detected within 6 h, four times faster than in the current gold standard method.

Isolation of Extracellular Vesicles from Cell Culture and Blood Through Nano-Targeted DLD Microfluidic Device.

Extracellular vesicles (EVs) are secreted by cells and found in biological fluids such as blood, with concentration correlated with oncogenic signals, making them attractive biomarkers for liquid biopsy. The current gold-standard method for EVs isolation requires an ultracentrifugation (UC) step among others. The cost and complexity of this technique are forbiddingly high for many researchers, as well as for routine use in biological laboratories and hospitals. This chapter reports on a simple microfluidic method for EVs isolation, based on a microfluidic size sorting technique named Deterministic Lateral Displacement (DLD). With the design of micrometric DLD array, we demonstrated the potential of our DLD devices for the isolation of nano-biological objects such as EVs, with main population size distribution consistent with UC technique.

Prevalence of Obstructive Sleep Apnea Using Home Sleep Test in Taiwan During the Coronavirus Disease Pandemic.

Obstructive sleep apnea syndrome (OSAS) is a common disorder associated with serious sequelae. The current gold standard diagnostic method, polysomnography, is costly and time consuming and requires patients to stay overnight at a facility. This study aimed to reveal the prevalence of OSAS in general adult population using a home sleep test (HST) during the coronavirus disease 2019 (COVID-19) pandemic. This prospective cohort study was conducted by the Department of Otolaryngology, Taipei City Hospital, Taipei, Taiwan, between January 2020 and December 2021. A total of 1372 patients aged 30-70 years completed an HST using a Type 3 portable sleep monitor (PM). The apnea-hypopnea index (AHI) was analyzed to assess the association of OSAS with age, body mass index (BMI), sex, Epworth Sleepiness Scale (ESS) and the Sleep Apnea Risk Assessment questionnaire (STOP-Bang questionnaire) rating. The mean age of the patients (782 men, 57%; 590 women, 43%) was 49.24 ± 11.04 years. OSAS was detected in 954 (69.5%) patients with 399 (29.1%) mild OSAS; 246 (17.9%) moderate OSAS; and 309 (22.5%) severe OSAS. Among these, the prevalence of moderate-to-severe OSAS was 143 (10.4%) in women and 412 (30.0%) in men. The mean age was the highest (51.29 ± 11.29) in the mild OSAS group and lowest (47.08 ± 10.87) in the healthy group. OSAS severity was greater with increasing BMI, 23.39 ± 3.44 in the healthy group and 29.29 ± 5.01 in the severe OSAS group. A positive correlation was also noted between the ESS/STOP-Bang questionnaire rating and OSAS severity. The prevalence of OSAS in Taiwan was 69.5% in our study. It showed strong evidence that OSAS has important public health consequences and PMs are simple, fast, feasible, and cost-effective tools for OSAS screening in the home environment, especially during the COVID-19 pandemic.

Radiomics to Differentiate Malignant and Benign Breast Lesions: A Systematic Review and Diagnostic Test Accuracy Meta-Analysis.

Breast cancer is a prevalent global health concern, necessitating accurate diagnostic tools for effective management. Diagnostic imaging plays a pivotal role in breast cancer diagnosis, staging, treatment planning, and outcome evaluation. Radiomics is an emerging field of study in medical imaging that contains a broad set of computational methods to extract quantitative features from radiographic images. This can be utilized to guide diagnosis, treatment response, and prognosis in clinical settings. A systematic review was performed in concordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines and the Cochrane Handbook for Systematic Reviews of Diagnostic Test Accuracy. Quality was assessed using the radiomics quality score. Diagnostic sensitivity and specificity of radiomics analysis, with 95% confidence intervals (CIs), were included for meta-analysis. The area under the curve analysis was recorded. An extensive statistical analysis was performed following the Cochrane guidelines. Statistical significance was determined if p-values were less than 0.05. Statistical analyses were conducted using Review Manager (RevMan), Version 5.4.1. A total of 31 manuscripts involving 8,773 patients were included, with 17 contributing to the meta-analysis. The cohort comprised 56.2% malignant breast cancers and 43.8% benign breast lesions. MRI demonstrated a sensitivity of 0.91 (95% CI: 0.89-0.92) and a specificity of 0.84 (95% CI: 0.82-0.86) in differentiating between benign and malignant breast cancers. Mammography-based radiomic features predicted breast cancer subtype with a sensitivity of 0.79 (95% CI: 0.76-0.82) and a specificity of 0.81 (95% CI: 0.79-0.84). Ultrasound-based analysis yielded a sensitivity of 0.92 (95% CI: 0.90-0.94) and a specificity of 0.85 (95% CI: 0.83-0.88). Only one study reported the results of radiomic evaluation from CT, which had a sensitivity of 0.95 (95% CI: 0.88-0.99) and a specificity of 0.56 (95% CI: 0.45-0.67). Across different imaging modalities, radiomics exhibited robust diagnostic accuracy in differentiating benign and malignant breast lesions. The results underscore the potential of radiomic assessment as a minimally invasive alternative or adjunctive diagnostic tool for breast cancer. This is pioneering data that reports on a novel diagnostic approach that is understudied and underreported. However, due to study limitations, the complexity of this technology, and the need for future development, biopsy still remains the current gold standard method of determining breast cancer type.

Combination of ultra-micro angiography and sound touch elastography for diagnosis of primary Sjögren's syndrome: a diagnostic test.

Primary Sjogren's syndrome (PSS) is a prevalent systemic autoimmune disease. However, the current gold standard diagnostic method is invasive, increasing the difficulty of patient acceptance and then delaying treatment. Therefore, a non-invasive, convenient, and effective diagnostic method is required. Although salivary gland ultrasonography (SGUS) is a good choice, previous studies have not found suitable parameters to diagnose PSS. Salivary gland involvement in patients with PSS leads to changes in gland stiffness and vascularization, so we combined sound touch elastography (STE) and ultra-microangiography (UMA) to demonstrate the diagnostic effectiveness of ultrasonography in PSS. This prospective study included 27 patients with PSS and 20 healthy controls, with all participants forming a random series. Major salivary glands were examined with UMA and STE. Color pixel percentage (CPP), shear wave velocity (SWV), and Young's modulus values were investigated, and the combination of these parameters was evaluated by logistic regression analysis. For Young's modulus and SWV in the elasticity index, combined evaluation of both parotid glands and submandibular glands yielded an area under the receiver operating characteristic (ROC) curve (AUC) and confidence interval (CI) of 0.819, 0.699-0.938 and 0.801, 0.677-0.925, respectively. The levels of CPP in the parotid glands were significantly elevated (P<0.003) among patients compared to those in the control group, whereas the CPP values in the submandibular glands were not statistically different (P>0.086). We evaluated the elasticity values of the total 4 glands and the CPP of parotid glands together by logistic regression modeling. The ROC curve yielded an AUC of 0.954 (95% CI: specificity 0.849-0.994) which showed the best accuracy, with 92.6% sensitivity and 85.0% specificity. The use of STE and UMA to examine the salivary glands may aid in the diagnosis of PSS, and their combination may be a promising method. This is good news for patients with PSS who are not suitable or unwilling to undergo labial gland biopsy.

Assessing the emotional states of dairy cows housed with or without their calves

There is growing interest in keeping dairy cows with their calves. Cow-calf contact or lack thereof is expected to affect emotional states, but this requires empirical testing. Different types of cow-calf contact may also affect the emotional states of cows. The primary objective of this study was to assess the emotional state of dairy cows with full-time (23 h/d), part-time (10 h/d), or no contact with their calves (separated 48 h after birth), using a visual judgement bias test (JBT) about one month after calving; JBT is the current gold-standard method to assess emotional state in animals by evaluating optimism or pessimism (illustrated by the proverbial half-full or half-empty water glass). The secondary objective was to compare outcomes of color- versus shape-based visual JBT. Fifty dairy cows were trained to approach a positive image on a screen (rewarded with food) and to avoid a negative image (else punished with waving bag). Once learned (>80% correct over 2 consecutive days), cows were presented with 3 ambiguous images (each presented once per day among 4 positive and 3 negative images, repeated over 4 d), and their approach responses recorded. For the color method (10 full-time, 9 part-time and 11 no-contact cows), positive and negative images were a solid red or white background; ambiguous images were shades of pink. For the shape method (8 full-time, 6 part-time and 6 no-contact cows), positive and negative images were a white circle or cross on a black background; ambiguous images were overlaid circle and cross in varying shades of gray. Cows learned to discriminate colors quicker than shapes (7.3 d, CL: 6.6 - 8.2 d; vs. 9.3 d, CL: 8.1 - 10.6 d; P = 0.01). Approaches to ambiguous colors followed a generalization curve (81.0, 33.1 and 5.0 ± 3.7% for near-positive, middle and near-negative images, respectively), but not approaches to ambiguous shapes (31.9, 25.7 and 21.9 ± 4.8%, respectively), indicating colors over shapes should be used in visual JBT for cattle. Part-time cows approached fewer ambiguous color images than full-time cows (23.5%, CL: 13.4 - 34.4%; vs. 44.8%, CL; 32.8 - 57.1%; P = 0.02) while no-contact cows were intermediate, but not different from full-time or part-time cows (37.8%, CL; 26.8 - 49.5%; P > 0.08). The color JBT results show a pessimistic bias (indicating a negative emotional state) in cows with part-time calf contact, possibly due to repeated daily separation from her young calf, relative to cows with full-time calf contact. Thus, cow-calf contact systems appear to influence the emotional state of cows depending on the practice. Cows without calf contact showed no difference in judgement bias between cows with full- or part-time calf contact, suggesting these cows probably do not experience a pervasive negative emotional state (relative to those with calf contact) approximately 30 d after calf separation. However, individual variability in judgement bias was evident for all treatments. The visual judgement bias test is a useful methodology for assessing emotional states of dairy cows; future research should prioritize understanding the emotional states of dairy cows in alternative management systems.

Validating MALDI-IMS Feasibility in Ex Vivo Brain Slices.

Matrix-assisted laser desorption ionization imaging mass spectrometry (MALDI-IMS) generates unique mass spectra in X/Y coordinates across a tissue sample, thus allowing for the spatial detection and relative quantification of biologic compounds in situ. The soft ionization of MALDI-IMS makes it an ideal technique for high-resolution imaging of complex lipid species. Lipid-based spatial chemical maps derived from MALDI-IMS provide critical insight into the unique molecular profiles of a variety of neurologic diseases. Ex vivo brain slice preparations are a prominent alternative to in vivo animal models for studying many different neurologic conditions. For the first time, we present a feasible protocol for achieving reproducible lipidomic MALDI-IMS data from ex vivo rat brain slices and provide evidence that ex vivo brain slices maintain spatiochemical lipidomic profiles representative of an intact whole brain. We conducted a methods comparison assessing the lipid profiles within the neocortex, striatum, and corpus callosum between coronal sections taken from ex vivo brain slices and the current gold standard tissue preparation method, fresh frozen whole brains. For the first time we demonstrate a technique by which 400 μm ex vivo brain slices can be extracted from an imaging chamber and prepared for MALDI-IMS in a way that preserves their lipidomic integrity. We demonstrate the feasibility of MALDI-IMS in ex vivo brain slices and provide a roadmap for MALDI-IMS utilization in uncharted neuroscience fields.

The role of MIBG scan in the diagnosis of pheochromocytoma.

e15064 Background: Pheochromocytoma is an uncommon adrenal medulla tumor. Metaiodobenzylguanidine (MIBG) scintigraphy is the current gold standard functional imaging method for evaluating pheochromocytoma, due to its excellent 100% specificity, 80% sensitivity, and general availability. In addition to establishing an extension evaluation and monitoring medication efficacy, MIBG scintigraphy is essential to confirm the diagnosis of suspected pheochromocytoma, especially when there is a tumor-like adrenal mass whose etiology is to be determined and biopsy is contraindicated given the risk of catecholamine discharge with hypertensive flare and the risk of bleeding. Our aims are to determine the efficacy of scintigraphy in the diagnosis of pheochromocytoma by examining the epidemiological characteristic and uptake patterns of the disease. Methods: In a retrospective analysis from January 2010 to December 2020, we examined pheochromocytoma patients medical records who had been referred for MIBG scintigraphy to the regional western Algerian Nuclear Medicine department at the University Hospital Center of Tlemcen. Prior to a progressive intravenous injection of 40–80 MBq of l-MIBG, patients underwent preparation (discontinuation of interfering drugs with I-MIBG especially antihypertensive treatment, thyroid blocking, and hydration). Imaging acquisition was carried out 48 and 72 hours later. Results: Fifty patients with probable pheochromocytoma (sex ratio = 0,78; mean age = 43 [17-74] years) completed I-MIBG scintigraphy prior to adrenalectomy. The MIBG scan has a high specificity and positive predictive value (100%). It confirms the presence of pheochromocytoma in 21 cases (42%), even if the metanephrine is normal in a patient with a non-secreting pheochromocytoma. In 18 cases, the main pattern is a single, homogenous, and intense intra-abdominal uptake. For the three remaining patients, a voluminous and heterogeneous uptake with a photopenic center that was associated to a necrotic adrenal mass larger than 10 cm in size, seen on abdominal Computerized Tomography (CT). In this retrospective analysis, no cases of metastatic or multiple diseases were documented. The sensitivity and negative predictive value are 84% and 86%, respectively. In 29 patients (58%), the scan reveals no abnormalities in uptake. This is attributed, in part, to 30% false positive biology (sampling conditions of urinary and/or plasmatic metanephrines and/or normetanephrines), 20% false positive CT imaging (differential diagnosis of adrenal mass: benign or malignant adrenal nodule), and 8% false negative MIBG scintigraphy (subcentimetric, cystic and necrotic lesion). Conclusions: Due to its exceptional specificity, robust sensitivity, and whole-body staging, MIBG scintigraphy—along with biology and morphology imaging—is a crucial noninvasive diagnostic method for the management of pheochromocytoma prior to adrenalectomy.