Paired Student Research Articles

Differential renal length index: useful measure in management of isolated unilateral hydronephrosis?

To explore the usefulness of the 'differential renal length index' (iDRL) before and after pyeloplasty, as the anteroposterior diameter is commonly used to quantify hydronephrosis but inaccuracies arise due to interobserver variability, hydration status and pure intra-renal dilatation. Prospectively collected data, from two centres, of all children undergoing pyeloplasty for isolated unilateral pelvi-ureteric junction obstruction (PUJO) (2015-2021) were analysed. Subgroup analysis was undertaken: Group A - differential renal function (DRF) ≥40%, Group B - subnormal DRF (20-39%), and Group C - symptomatic. Children with structural anomalies of upper and lower urinary tract, bilateral involvement, and subnormal DRF (<20%) were excluded. All the children had a pre- and postoperative ultrasound scan and Tc99m mercapto-acetyltriglycine (MAG3) renograms. The iDRL was calculated as follows: iDRL = ([a - b]/b) × 100, where 'a' is the length of hydronephrotic kidney (cm) and 'b' is the length of contralateral normal kidney (cm). The mean difference and standard error of mean (SEM) between the pre- and postoperative iDRL was evaluated using the paired Student's t-test, with P < 0.05 considered statistically significant. A total of 119 children with 1-year follow-up were included. For the entire cohort, the mean (SEM) preoperative iDRL was 27.7 (1.4) and postoperatively was 12.5 (1.1), with a mean (range) DRF improvement of 54% (44-66%) (P < 0.001). In Group A (n = 97), the mean (SEM) preoperative iDRL was 26.6 (1.5) and postoperatively was 13.1 (1.2), with a mean (range) DRF improvement of 50% (38-63%) (P < 0.001). In Group B (n = 22), the mean (SEM) preoperative iDRL was 32.6 (3.5) and postoperatively was 10.0 (2.8), with a mean (range) DRF improvement of 69% (49-89%) (P < 0.001). In Group C (n = 28), the mean (SEM) preoperative iDRL was 19.9 (2.3) and postoperatively was 7.7 (1.9), with a mean (range) DRF improvement of 61% (38-85%) (P < 0.001). Our study identifies the iDRL as a useful measure of improvement following successful pyeloplasty. In the subgroup with DRF of >39% minimum improvement was >37%. Similar minimum DRF improvement was also noted (>37%) in hypo-functioning kidneys and symptomatic PUJO.

The cognitive engagement of students in pairs when using learning objects

This article discuss the potential use of Learning Objects for use with students organized in pairs in the school activities context.We will present data collected throughout a PhD research that sought to verify whether grouping into pairs during activities in the computer laboratory enables students' cognitive engagement. The investigation included the participation of 1st year and three 2nd year classes of elementary school in a Brazilian public school. The methodological approach used was Action Research and data collection took place during a complete academic year. In general, the results presented in this work allow us to affirm that the use of Learning Objects enables students' cognitive engagement during activities and that there is no significant difference in engagement between students who were organized in pairs and those who were working alone.

Age-related changes of intraocular pressure in Dutch belted rabbits.

This study investigated intraocular pressure (IOP) in Dutch belted rabbits using two different tonometers, rebound tonometry (TonoVet Plus; TVP) and a Tonopen (Tono-Pen AVIA Vet; TPA). Post-pubescent male Dutch belted rabbits aged 36weeks (n = 10 animals) were used in the study. IOP measurements were conducted every 2weeks for 22weeks using TVP and TPA on both eyes of each rabbit. The average IOP measurements were compared by the paired Student's t-test. Pairwise Pearson's correlation coefficients and Bland-Altman statistics were used. The overall mean IOP measured with TPA was significantly higher than that with TVP (23.5 ± 4.9 vs. 21.8 ± 2.4mmHg for the right eyes; P = 0.045, and 23.0 ± 4.7 vs. 21.5 ± 2.4mmHg for the left eyes; P = 0.047). Both tonometers tended to show increased IOP readings with age, and positive correlations between IOP and age were observed with both TPA (r = 0.95, P < 0.001 for right eyes; r = 0.95, P < 0.001 for left eyes) and TVP (r = 0.91, P < 0.001 for right eyes; r = 0.64, P = 0.024 for left eyes). The average bias calculated by subtracting TPA from TVP was - 1.60(95% confidence intervals - 1.927, - 1.281)mmHg. IOP in post-pubescent Dutch belted rabbits tended to increase with age throughout the 22week study.

Selective dual sensing strategy for free and vitamin D3 micelles in food samples based on S,N-GQDs photoinduced electron transfer.

A reliable nanotechnological sensing strategy, based on anS,N-co-doped graphene quantum dot (GQD) platform, has been developed to distinctly detect two key variants of vitamin D3, specifically the free (VD3) and the nanoencapsulated form (VD3Ms). For this purpose, food-grade vitamin D3 micelles were self-assembled using a low-energy procedure (droplet size: 49.6 nm, polydispersity index: 0.34, ζ-potential: -33 mV, encapsulation efficiency: 90 %) with an innovative surfactant mixture (Tween 60 and quillaja saponin). Herein, four fluorescent nanoprobes were also synthesized and thoroughly characterized: S,N-co-doped GQDs, α-cyclodextrin-GQDs, β-cyclodextrin-GQDs, and γ-cyclodextrin-GQDs. The goal was to achieve a selective dual sensing strategy for free VD3 and VD3Ms by exploiting their distinctive quenching behaviors. Thus, the four nanosensors allowed the individual sensing of both targetsto be performed (except α-CD-GQD for VD3Ms), but S,N-GQDs were finally selected due to selectivity and sensitivity (quantum yield, QY= 0.76) criteria. This choice led to a photoinduced electron transfer (PET) mechanism associated with static quenching, where differentiation was evidenced through a displayed 13-nm hypsochromic (blue) shift when interacting with VD3Ms. The reliability of this dual approach was demonstrated through an extensive evaluation of analytical performance characteristics. The feasibility and accuracy were proven in commercial food preparations and nutritional supplements containing declared nanoencapsulated and raw VD3, whose results were validated by a paired Student's t-test comparison with a UV-Vis method. To the best of our knowledge, this represents the first non-destructive analytical approach addressing the groundbreaking foodomic trend to distinctly detect different bioactive forms of vitamin D3, while also preserving their native nanostructures as achemical challenge, thus providing reliable information about their final stability and bioavailability.

Vitamin D Metabolites Before and After Kidney Transplantation in Patients Who Are Anephric

Rationale & ObjectiveKidneys are vital for vitamin D metabolism and disruptions in both production and catabolism occur in chronic kidney disease. Although vitamin D activation occurs in numerous tissues, the kidneys are the most relevant source of circulating active vitamin D. This study investigates extrarenal vitamin D activation and the impact of kidney transplantation on vitamin D metabolism in patients who are anephric. Study DesignCase series. Setting & ParticipantsAdult patients with previous bilateral nephrectomy (anephric) not receiving active vitamin D therapy were evaluated at the time of (N=38) and 1 year after (N=25) kidney transplantation. Liquid chromatography–tandem mass spectrometry was used to measure vitamin D metabolites. Metabolic ratios were expressed CYP24A1 (24,25(OH)2D/25(OH)D) and CYP27B1 (1α,25(OH)2D/25(OH)D) as activities. Differences between evaluation timepoints were evaluated by paired Student’s t-test or Wilcoxon matched-pairs signed-rank test. FindingsAt time of transplantation, 1α,25(OH)2D was detectable in all patients (4 to 36 pg/mL). There was a linear relationship between 25(OH)D and 1α,25(OH)2D-levels (r=0.58, p<0.001) with 25(OH)D explaining 34% of the variation in 1α,25(OH)2D-levels. There were no associations between 1α,25(OH)2D and biointact PTH or FGF23. One year after transplantation, 1α,25(OH)2D levels recovered (+205%) and CYP27B1 activity increased (+352%). Measures of vitamin D catabolism, 24,25(OH)2D and CYP24A1 activity increased 3-5 fold. Also at 12 months after transplantation, 1α,25(OH)2D was positively correlated with PTH (rho=0.603, p=0.04), but not with levels of 25(OH)D or FGF23. LimitationsRetrospective, observational study design with a small cohort size. ConclusionsLow-normal levels of 1α,25(OH)2D was demonstrated in anephric patients, indicating production outside of the kidneys. This extrarenal CYP27B1 activity may be more substrate-driven than hormonally regulated. Kidney transplantation seems to restore kidney CYP27B1 and CYP24A1 activity, as evaluated by vitamin D metabolic ratios, resulting in both increased vitamin D production and catabolism. These findings may have implications for vitamin D supplementation strategies in the setting of kidney failure and transplantation.

Learning Package impact on awareness about danger signs of pregnancy

Background: All pregnant women by virtue of their pregnant status face some level of maternal risk. Data suggest that around 40% of all pregnant women have some complications. Therefore, present study aims to assess effectiveness of learning package on awareness regarding danger signs of pregnancy. Method: Pre experimental research design with Quantitative approach was applied to conduct the study. A sample of 120 antenatal women selected for the study through non probability purposive sampling technique. Results: The mean pretest knowledge score was 13.52 ± 2.62, whereas mean posttest knowledge score was 24.52 ± 3.83. The post-test mean value knowledge score among antenatal women was significantly higher than the pretest knowledge score. The mean difference was 11 The paired student “t” test value was 33.67 which was significant at p=0.05 level. The findings revealed that there was no significant association between knowledge score with selected demographic variables of the antenatal women. Conclusion: Findings of our study strongly recommend the need for conducting learning program to increase the awareness regarding danger signs of pregnancy among antenatal women.

Pilot study for three-dimensional cephalometric Enlow's counterpart analysis: Vertical track. Two-dimensional and three-dimensional comparison.

The introduction of cone beam computed tomography (CBCT) in dentistry has given orthodontists the possibility of studying craniofacial structures in three dimensions. Despite the possibility to obtain lateral cephalograms synthesized from CBCT, this approach still does not provide a fully three-dimensional evaluation of the patient's anatomy. While there has been some success in adapting traditional two-dimensional cephalometric analyses to three dimensions, the specific application of Enlow's cephalometric analysis using CBCT remains unexplored. This pilot study aims to introduce a novel approach for performing Enlow's vertical track analysis using CBCT images. Eighteen CBCT images of skeletal Class I (ANB = 2 ± 2) subjects (12 males and 6 females, aged from 9 to 19 years) with no history of previous orthodontic treatment were selected. For each subject, 2D Enlow's vertical track analysis was performed on lateral cephalograms extracted from the CBCT images, and separately, 3D vertical track analysis was directly performed on the CBCT images. To validate the proposed method, we compared the differences between the posterior vertical counterpart (PVC) and the middle vertical counterpart (MVC), as well as between the middle vertical counterpart (MVC) and the anterior vertical counterpart (AVC), as obtained from both the two-dimensional and three-dimensional analyses. The Kolmogorov-Smirnov normality test was applied for each variable to check whether data were normally distributed and a paired Student's t-test was performed. The level of statistical significance was .05. The comparison between three-dimensional PVC-MVC (-0.43 ± 0.37 cm) and two-dimensional PVC-MVC (-0.53 ± 0.36 cm) revealed no statistical difference (P = .27). Similarly, no significant difference (P = .28) was observed between two-dimensional MVC-AVC (-0.56 ± 0.34 cm) and three-dimensional MVC-AVC (-0.47 ± 0.37 cm). The method proposed by this study to realize the vertical track analysis on 3D images is valid and superimposable on that described by Enlow on lateral cephalograms.

Changes in Fingertip Cold-Induced Vasodilatation (Hunting Reaction) on Acute Exposure to Altitude.

Fossati, Alexandre, and Aleid C. J. Ruijs. Changes in fingertip cold-induced vasodilatation (hunting reaction) on acute exposure to altitude. High Alt Med Biol. 25:212-217, 2024. Objective: Cold-induced vasodilation (CIVD) of the extremities is an interesting part of human physiology. Although the physiology of the CIVD reaction remains unknown, there are indications that hypoxia influences our CIVD reaction. The objective of this study is to measure the influence of acute hypoxia on the CIVD reaction of the fingertips. Methods: The CIVD reaction was measured using immersion of one hand in a water bath of 0°C in 12 healthy volunteers at low (1,235 m) and high (3,800 m) altitude during 35 minutes. High altitude was reached by a 20-minute cable car ride. Testing was performed indoors (room temperature, 22-25°C) at both altitudes. Data analysis was performed measuring the parameters of the CIVD reaction. Differences were found using the paired Student's t-test. Results: There was no significant difference in baseline finger temperature, onset time, peak time, and frequency of the CIVD reaction. However, at high altitude, maximum temperature and amplitude were significantly higher, slope was steeper, and minimum temperature was lower. Conclusion: We did not find evidence for a diminished CIVD reaction at high altitude due to hypoxia.

Hand hygiene in emergencies: Multiprofessional perceptions from a mixed methods based online survey in Germany

IntroductionDespite high vulnerability to infection, hand disinfection compliance in emergencies is low. This is regularly justified as the disinfection procedure delays life support, and instead, wearing disposable gloves is preferred. Simulation studies showed higher achievable compliance than detected in real-life situations. This study aimed to explore healthcare providers’ attitudes toward hand disinfection and using gloves in emergencies. MethodsWe conducted an anonymous online survey in Germany on the attitude and subjective behavior in the five moments of hand hygiene in a closed environment and an open convenience sampling survey. Statistics included paired student's t-tests corrected for multiple testing. For qualitative analysis, we employed a single-coder approach. ResultsIn 400 participants, we detected low priority of WHO-1 (before touching a patient) and WHO-2 (before clean/aseptic procedure) hand hygiene moments, despite knowing the risks of omission of hand disinfection. For all moments, self-assessment exceeded the assessment of colleagues (p < 0.001). For WHO-3, we detected a lower disinfection priority for wearing gloves compared to contaminated bare hands. Qualitative analyses revealed five themes: basic conditions, didactic implementations, cognitive load, and uncertainty about feasibility and efficacy. DiscussionConsidering bias, the study's subjective nature, the unknown role of emergency-related infections contributing to hospital-acquired infections, and different experiences of healthcare providers, we conclude that hand disinfection before emergencies is de-prioritized and justified by the emergency situation regardless of the objective feasibility. ConclusionThis study reveals subjective and objective barriers to implementation of WHO-1 and WHO-2 moments of hand disinfection to be further evaluated and addressed in educational programs.

The Primary Care and Environmental Health e-Learning Course to Integrate Environmental Health in General Practice: Before-and-After Feasibility Study.

Environmental and behavioral factors are responsible for 12.6 million deaths annually and contribute to 25% of deaths and chronic diseases worldwide. Through the One Health initiative, the World Health Organization and other international health organizations plan to improve these indicators to create healthier environments by 2030. To meet this challenge, training primary care professionals should be the priority of national policies. General practitioners (GPs) are ready to become involved but need in-depth training to gain and apply environmental health (EH) knowledge to their practice. In response, we designed the Primary Care Environment and Health (PCEH) online course in partnership with the Occitanie Regional Health Agency in France. This course was used to train GP residents from the Montpelier-Nimes Faculty of Medicine in EH knowledge. The course was organized in 2 successive parts: (1) an asynchronous e-learning modular course focusing on EH knowledge and tools and (2) 1 day of face-to-face sessions. This study assessed the impact of the e-learning component of the PCEH course on participants' satisfaction, knowledge, and behavior changes toward EH. This was a pilot before-and-after study. Four modules were available in the 6-hour e-learning course: introduction to EH, population-based approach (mapping tools and resources), clinical cases, and communication tools. From August to September 2021, we recruited first-year GP residents from the University of Montpellier (N=130). Participants' satisfaction, knowledge improvements for 19 EH risks, procedure to report EH risks to health authorities online, and behavior change (to consider the possible effects of the environment on their own and their patients' health) were assessed using self-reported questionnaires on a Likert scale (1-5). Paired Student t tests and the McNemar χ2 test were used to compare quantitative and qualitative variables, respectively, before and after the course. A total of 74 GP residents completed the e-learning and answered the pre- and posttest questionnaires. The mean satisfaction score was 4.0 (SD 0.9) out of 5. Knowledge scores of EH risks increased significantly after the e-learning course, with a mean difference of 30% (P<.001) for all items. Behavioral scores improved significantly by 18% for the participant's health and by 26% for patients' health (P<.001). These improvements did not vary significantly according to participant characteristics (eg, sex, children, place of work). The e-learning course improved knowledge and behavior related to EH. Further studies are needed to assess the impact of the PCEH course on clinical practice and potential benefits for patients. This course was designed to serve as a knowledge base that could be reused each year with a view toward sustainability. This course will integrate new modules and will be adapted to the evolution of EH status indicators and target population needs.

Abstract PO5-06-06: Tumor/stromal expression of CD3/CD8/PD-1/PD-L1 and overall survival (OS) in patients (pts) with metastatic (met) HER2+ breast cancer (BC)

Abstract Background: The “Thousand Patient HER-2 database” project at Saint Vincent’s University Hospital (SVUH) Dublin contains a cohort of met HER2+ BC pts treated with trastuzumab, with OS ranging from short term to durable complete response (never relapsed). While the majority of pts progress on treatment, higher stromal tumor immune infiltrate has been associated with longer OS in met HER2+ BC. Using the SVUH database, we have identified a cohort of met HER2+ BC pts that received trastuzumab and have a broad OS range (0.3 months (mos) to 200.9 mos). This study examines the tumor and stromal levels of pan T cell marker CD3, cytotoxic T cell marker CD8, and immune checkpoints PD-L1 and PD-1 by immunohistochemistry (IHC) in primary and met samples from this cohort. Methods: Clinico-pathological data was available for formalin-fixed, paraffin-embedded biopsy specimens (n=45 primary, n=25 matched met biopsies). IHC staining was conducted for CD3 (Agilent IR50361-2), CD8 (Agilent IR62361-2), PD-L1, (Agilent M365329-2), and PD-1 (Roche 07099029001). A DAKO Link 48 Autostainer was utilised for staining, incorporating positive (tonsil tissue) and negative controls (isotype controls). Slide processing used an Aperio AT2 Digital Slide Scanner (Leica Biosystems), Aperio ImageScope 12.4 software (Leica Biosystems) and QuPath analysis software (University of Edinburgh). Following annotation of tumor areas, an algorithm was trained to identify immune cells and designate them as tumor or stromal. Data was expressed as the number of positively stained cells/mm2 tissue. A median cut-off was applied to denote “high” and “low” expression for CD3 and CD8. For PD-1 and PD-L1, samples with ≥ 1 stained cell/mm2 were designated as positive (pos) and samples with zero stained cells as negative (neg). The Kaplan Meier method was utilised for survival studies. A paired Student’s t test was utilised for primary vs metastatic site comparisons. Results: 51.1% of primary samples displayed high CD3 (23/45) and CD8 (23/45) expression in both the stromal and tumor compartments. Within the tumor compartment, 18.6% (8/43) of samples were pos for PD-L1 expression, and 57.8% (26/45) were pos for PD-1 expression. In the stromal compartment, 30.2% (13/43) of samples were pos for PD-L1 expression, and 68.9% (31/45) were pos for PD-1 expression. High tumor levels of CD3 (median OS CD3 high 113.4 mos vs CD3 low 7.9 mos, HR 0.2938 (95% CI 0.130-0.618), p=0.0012) and CD8 (median OS CD8 high 73.9 mos vs CD8 low 10.8 mos, HR 0.4764 (95% CI 0.238-0.954), p=0.0365), but not stromal levels of these markers, were associated with improved OS. There were no significant differences in CD3, CD8, PD-1 and PD-L1 levels between matched primary and met samples (p &amp;gt;0.05). Tumor, but not stromal, PD-L1 expression was associated with longer OS (HR 0.3120 (95% CI 0.146-0.667), p=0.0027). Interestingly, stromal PD-1 expression, but not tumor PD-1 expression, was also associated with longer OS (median OS PD-1 pos 64.7 mos vs. PD-1 neg 5.6 mos, HR 0.158 (95% CI 0.060-0.411), p=0.0002). Conclusion: Our results report a link between OS and tumor (CD3+, CD8+ and PD-L1+)/stromal (PD-1+) immune cell infiltrate in met HER2+ BC patients treated with trastuzumab. Further expansion of this preliminary dataset is warranted. Citation Format: Denis Collins, Janet McCormack, Laura Ivers, Jose Javier Berenguer-Pina, Jo Ballot, Cecily Quinn, Darko Skrobo, Alex Eustace, Naomi Walsh, Aurelie Fabre, John Crown. Tumor/stromal expression of CD3/CD8/PD-1/PD-L1 and overall survival (OS) in patients (pts) with metastatic (met) HER2+ breast cancer (BC) [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO5-06-06.

The Importance of Interprofessional Education in Developing Collaboration-Ready Biomedical Scientists For Translational Research

The biomedical sciences have advocated for interdisciplinary training to bridge the bench-to-bedside gap and strengthen translational research outcomes. As a functional extension of interdisciplinary collaboration, interprofessional education (IPE) represents a viable solution to strengthen collaborative relationships among basic science researchers and other health professional students at a very early stage in their academic journey in order to benefit patient-centered care. To support this direction, we developed a two-year longitudinal IPE curriculum at our institution (6 schools and 19 programs) termed TEAM UPTM. The focus of TEAM UPTM Year 1 includes building an interprofessional team while developing effective communication and collaboration skills. Case-based activities and a Health Partner Project are the main learning activities during the year. The Health Partner Project connects each diverse student team with an individual in the community to learn about the Health Partner's lived experiences and health-related goals. For the purposes of this report, we evaluated post-Year 1 individual perceptions and reflection assignments. The past 5 cohorts (2018-2022) have included a total of 42 biomedical sciences students (2018=10; 2019=11; 2020=10; 2021=8; 2022=3). After the final Year 1 session, students were asked to complete two assignments: a quantitative IPE perceptions survey and a written reflection focused on their interprofessional growth over the past academic year. IPE perceptions were measured using the Student Perceptions of Interprofessional Clinical Education-Revised Instrument, Version 2 (SPICE-R2) and examined retrospectively. We hypothesized that student SPICE-R2 scores would increase following participation in the TEAM UPTM curriculum. Indeed, when data are pooled across all five years, students exhibited a significant increase in total SPICE-R2 scores (p&lt;0.001 by paired Student’s t-test). SPICE-R2 subscores were also analyzed separately, representing IPE attitudes related to (A) Teamwork, (B) Roles &amp; Responsibilities, and (C) Patient Outcomes. One-way repeated-measures ANOVA analysis of score changes discovered a significant main effect of subscore category (p&lt;0.001), with subsequent Bonferroni post hoc analyses revealing greater changes in the Roles &amp; Responsibilities subscore (p&lt;0.001) relative to the Teamwork and Patient Outcomes subscores. Student reflections were also analyzed using a qualitative approach, indicating a greater appreciation of communication skills as applied to decision-making and belief that building relationships with health providers would allow for better translational research. These findings highlight IPE as an innovative strategy to support collaborative mindsets and bidirectional relationships between biomedical science researchers and health providers at an early educational stage. P60AA009803. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Sulfonylureas Compromise Microvascular Flow in Mouse Skeletal Muscle

Sulfonylureas are among the most prescribed oral anti-hyperglycaemics, particularly in low- and middle-income countries. Sulfonylureas are insulin secretagogues through blocking ATP-sensitive potassium channels (KATP) in β-cells of the pancreas. Despite wide usage, sulfonylureas are associated with increased cardiovascular disease morbidity and all-cause mortality, with ill-defined mechanisms. We tested the hypothesis that glyburide could block KATP channels in the microvasculature, thereby disrupting tissue oxygen demand-supply balance. We further investigated the contribution of other potassium channels to capillary-to-arteriole signalling. Experiments were conducted using an in-vivo anesthetized mouse skeletal muscle preparation (extensor digitorum longus, EDL); exteriorized and situated at in-situ length, overtop an oxygen-permeable membrane covering a gas chamber, and bathed in PlasmaLyte. C57BL/6 mice were employed (n=6-8). Brightfield images were captured at two wavelengths: oxygen-dependent and oxygen-independent, enabling the simultaneous determination of capillary hemodynamics and RBC oxygen content. Low oxygen challenges were achieved by dropping oxygen levels in the gas chamber from 7% to 2% for 3 minutes. Challenges were conducted before (control) and after drugs were added to bathing solution. Parameters were obtained before the challenge (baseline), during the challenge (2 regions) and after the challenge (recovery). Statistical significance was determined using a paired Student’s t-test. Target channels localization was investigated using immunofluorescence in formalin-fixed EDL. Oxygen challenges augmented EDL surface capillary hematocrit and RBC velocity and supply rate, while reducing RBC oxygen saturation. Incubation of the EDL with 10 μM glyburide decreased the baseline RBC supply rate (p&lt;0.05 vs control) and blunted the magnitude of capillary responses to the oxygen challenge (p&lt;0.05 vs control). Immunofluorescence confirmed the localization of KATP channels in EDL capillaries. Normal capillary responses were obtained when small and intermediate conductance or inward rectifier potassium channels were neutralized. This implies minimal or no contribution of these channels in oxygen signaling in the microvasculature. This data begins to elucidate the acute and direct effects of systemic KATP blockers on capillary-to-arteriole conducted signaling, which is likely key to optimal tissue oxygen regulation. Further experiments are warranted to confirm this conclusion. This work was supported by the Natural Science and Engineering Research Council of Canada (NSERC, RGPIN/04659-2017), an Ontario Graduate Scholarship (M.A.E) and a CIHR doctoral award (M.A.E). This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

A Comparison of 06:00 AM Versus 09:00 AM Serum Cortisol as a Basal Morning Cortisol in Guwahati, Assam: A Pilot Study.

Cortisol secretion is regulated by circadian rhythm, which is influenced by zeitgebers like light. In India, the entire country operates under a single time zone, Indian Standard Time, which may not align with the local sunrise timing across different regions. This study aimed to compare the basal serum cortisol levels between 06:00 AM and 09:00 AM in Guwahati, Assam, where sunrise occurs earlier compared with the western part of the country. A cross-sectional pilot study was conducted from December 2022 to June 2023 in a tertiary care hospital in Guwahati. Serum cortisol samples were collected at 06:00 AM and 09:00 AM from 25 healthy adult participants once in winter and again in summer. Descriptive statistics and paired Student's t-tests were used. The mean serum cortisol levels at 06:00 AM in winter, summer and overall were 13.2, 13.4 and 13.3 μg/dL, respectively. At 09:00 AM, the mean serum cortisol levels in winter, summer and overall were 8.2, 7.7 and 8.0 μg/dL, respectively. Significant differences were observed between the 06:00 AM and 09:00 AM cortisol levels in both winter and summer (P <0.001). This study highlights the importance of considering the influence of earlier sunrise on circadian rhythm, cortisol secretion and sampling protocols. Recognising the impact of earlier sunrise on cortisol secretion and adapting sampling protocols accordingly to align with the local sunrise can provide a more accurate assessment of basal cortisol levels and help avoid potential misinterpretation and diagnostic challenges associated with low values.

Induction of TNFα by flavin adenine dinucleotide (FADH) protects neonatal C57Bl6 lungs from high oxygen induced lung injury

Background: Bronchopulmonary dysplasia (BPD) is a serious lung disease caused by oxidative stress, predominately affecting premature infants that require prolonged oxygen support. The co-factor flavin adenine dinucleotide (FADH) facilitates glutathione reductase (GR) enzymatic activity and increases the bioavailability of the antioxidant glutathione (GSH). As such, we hypothesized that intranasal delivery of FADH can improve redox homeostasis and attenuate lung injury following chronic high oxygen supplementation (0.85% FiO2) by altering pro-inflammatory signal transduction pathways in a C57Bl6 newborn mouse model for BPD. Methods: We used a prolonged hyperoxia-induced lung injury rodent model to recapitulate the clinical and histological changes present in BPD. Newborn mice were housed in FiO2 85% (hyperoxic) or 21% O2 (normoxic) from day of birth until post-natal day (PN) 14. FADH (7 μM) or saline (control) treatments were administered daily via intranasal insufflation on PN 14-21 in a final volume of 1.5μL/g body weight. BALF and lung tissue samples were collected and evaluated for redox stress, lung injury/development, and inflammation using standard immunohistological techniques, morphometric analysis, and standard molecular assays. BALF cytokines were measured using a flow cytometric approach (BioLegend). Two-dimensional cell migration assays were tracked via microscopy daily until 100% confluence reached; the ½ maximal peak values were evaluated to compare rate of wound closure following very low (2.5 ng/mL) TNFα or IL12 treatment. Transepithelial resistance and potential differences were measured using an EVOM device (World Precision Instrument) across human small airway epithelial cells, and equivalent short circuit currents (Isc) calculated in accordance with Ohm’s Law, where V=IR. Single data comparisons were performed using paired Student’s t-tests. Multiple comparisons were performed using ANOVA followed by post-hoc testing in Sigma Plot. Results: FADH protected neonatal lungs from high oxygen induced oxidative stress: GSH/GSSG Eh (a measure of oxidative stress) improved from -168.77 mV ± 3.64 mV to -179.10 mV ± 1.85 mV (n=5 BALF measurements). FADH also improved lung injury scores from 0.187±0.038 to 0.03±0.014 (p=0.005), decreased neutrophil migration (p&lt;0.001), and increased macrophages (p&lt;0.001) when compared to age-matched untreated pups. FADH-mediated increase in TNFα (and not IL12) significantly increased the rate of lung epithelial cell wound closure from [2.27±0.07 to 1.97±0.1 average days for ½ complete wound closure, n=6, p=0.01] and increased Isc from 6.5±.21 to 9.2±1.0 μA/cm2, n=3, p=0.03. Conclusions: Our findings indicate that FADH protects the preterm lung from hyperoxic injury by 1) increasing the bioavailability of GSH and 2) via TNFα signaling to increase the rate of wound closure and repair of epithelial cell function. Significances: The mechanisms identified through this study could be targeted as a potential adjunct therapy for BPD patients to attenuate high oxygen induced lung injury. Funding: Supported by R01HL137033 (MH). This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

The Role of 24-hydroxylase in Homeostatic Regulation of 1,25-dihydroxyvitamin D

Background. Because of the importance of vitamin D (VitD) in calcium balance and bone health, the body has evolved effective homeostatic mechanisms to maintain 1,25-dihydroxyvitamin D [1,25(OH)2D] — the biologically active form — in a narrow physiological range. Objective and hypothesis. We developed a mathematical model to investigate homeostatic mechanisms regulating VitD metabolism with the objective of elucidating regulatory mechanisms maintaining levels of 1,25(OH)2D within a narrow physiological range despite wide variation in availability of VitD. Methods. We studied 11 otherwise healthy VitD deficient [25(OH)D&lt;20 ng/mL] participants before and after VitD3 supplementation (50,000 IU once or twice a week depending on BMI for 4-6 weeks). We measured 25(OH)D, 1,25(OH)2D, 24,25(OH)2D, PTH, and FGF23. We used a 2-tailed paired Student’s t-test to analyze our data; p=0.05 was selected as the criterion for statistical significance. This represents a secondary analysis of a previously published clinical trial [Shahidzadeh Yazdi et al. (2023) J Clin Endocrinol Metab, doi: 10.1210/clinem/dgad554]. Results. VitD3 supplements induced a significant 2.7-fold increase (p=0.0006) in mean 25(OH)D and a 4.3-fold increase (p=0.0002) in 24,25(OH)2D, but did not change 1,25(OH)2D, PTH, or FGF23. Our model showed that 24-hydroxylase activity was regulated over a 10-fold range — with maximal induction for 25(OH)D&gt;50 ng/mL and maximal suppression for 25(OH)D&lt;10-20 ng/mL). Because 24-hydroxylase catalyzes metabolic clearance of 1,25(OH)2D, high levels protect against VitD toxicity and low levels preserve 1,25(OH)2D when VitD is scarce. Thus, suppression of 24-hydroxylase activity is a homeostatic mechanism reflecting the body’s perception of VitD deficiency. Accordingly, measurements of 24,25(OH)2D levels can contribute to assessment of VitD status. However, measurements of total levels of all VitD metabolites [including 24,25(OH)2D] are confounded by the ~3-fold inter-individual variation in VitD binding protein (VDBP) levels. Fortunately, the ratio of 1,25(OH)2D /24,25(OH)2D is independent of VDBP levels. Our analysis suggests that this ratio provides a superior assessment of VitD status compared to the current recommendation to measure total 25(OH)D. For example, 24-hydroxylase activity is highly correlated with 1,25(OH)2D /24,25(OH)2D (ρ2=0.91) but less well correlated with 25(OH)D (ρ2=0.91). Conclusions. The body has two defense mechanisms to protect against VitD deficiency. The first line of defense is suppression of 24-hydroxylase, which is triggered by mild-moderate VitD deficiency and preserves VitD from degradation. However, at times of severe VitD deficiency, the first line of defense may be insuffcient to maintain 1,25(OH)2D in a physiological range. Therefore, the body triggers a second line of defense — secondary hyperparathyroidism, which in turn upregulates 1-hydroxylation and increases production of 1,25(OH)2D. By better understanding the physiology of homeostatic regulation of VitD metabolism, physicians can advance the state-of-the-art in diagnosing and treating VitD deficiency. Funding: R01DK118942; T32DK098107. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

L’électroconvulsivothérapie, toute une (psycho)éducation !

BackgroundElectroconvulsive therapy (ECT) remains an essential, yet often stigmatized, treatment in psychiatry. Addressing this issue, our study introduces and evaluates a psychoeducational intervention aimed at demystifying ECT for patients and their caregivers, using the QuAKE (Questionnaire on Attitudes and Knowledge of ECT). MethodsThis psychoeducational approach was designed for individuals indicated for ECT and their caregivers. The session's effectiveness was gauged by comparing pre- and post-intervention QuAKE scores. Statistical significance was determined using paired Student t-test. ResultsThe study included 20 participants, with caregivers constituting 90% of the sample. The intervention led to a statistically significant increase in knowledge (mean increase of 7.55 points, p<0.001) and a notable decrease in stigmatizing attitudes (mean decrease of 9 points, p<0.001) towards ECT, as measured by the QuAKE scales. DiscussionThe significant improvements in both knowledge and attitudes underline the potential benefits of incorporating psychoeducational interventions into ECT treatment protocols. Future research should further explore the role of such interventions in the broader treatment pathway, enhancing patient and caregiver understanding and acceptance of ECT.

Impact of Respiratory-gated 4D PET/CT Scan for Motion Correction in Characterizing Lesions Adjacent to the Diaphragm - A Cross-sectional Study at a Tertiary Care Institute.

The blur introduced by breathing motion degrades the diagnostic accuracy of whole-body F-18 fluorodeoxyglucose positron emission tomography-computed tomography (18F-FDG PET-CT) in lesions adjacent to the diaphragm by increasing the apparent size and by decreasing their metabolic activity. This study aims to evaluate the efficacy of motion correction by four-dimensional phase-based respiratory-gated (RG) 18F-FDG PET-CT in improving metabolic parameters of lesions adjacent to the diaphragm (especially in the lungs or liver). Eighteen patients with known lung or liver lesions underwent conventional 18F-FDG PET-CT and respiratory-gated PET-CT acquisition of the desired region using a pressure-sensing, phase-based respiratory-gating system. Maximum standardized uptake value (SUVmax), metabolic tumor volume (MTV), and total lesion glycolysis (TLG) were obtained for these lesions from gated and nongated PET-CT images for analysis. Furthermore, a visual analysis of lesions was done. Statistical significance of the RG image parameters was assessed by the two-tailed paired Student's t test and confirmed with the robust nonparametric Wilcoxon's signed-rank test (two-tailed asymptotic). There was an overall significant increase in SUVmax (P 0.001) in all gating methods with a percentage increase maximum of about 18.13%. On gating methods, MTV decreased significantly (P = 0.001) than that of nongating method (maximum reduction of about 32.9%). There was a significant difference (P = 0.02) in TLG between gated and nongated methods. Motion correction with phase-based respiratory gating improves the diagnostic value of 18F-FDG PET-CT imaging for lung and liver lesions by more accurate delineation of the lesion volume and quantitation of SUV and can thus impact staging, diagnosis as well as management in selected patients.

Optimizing Individual Wound Closure Practice Using Augmented Reality: A Randomized Controlled Study.

Background Suturing requires repeated practice with guidance to prevent skill deterioration; however, guidance is often limited by expert availability. There is evidence that augmented reality (AR) may assist procedural skill acquisition among learners. This study examines the use of an AR suture guidance application to assist the independent practice of suturing. Methodology A novel suture guidance application was designed for the Microsoft HoloLens. The guidance system included a calibration system and holograms that projected over a suture pad in a stepwise manner. To assess the application, 30 medical students were recruited and randomly assigned to two groups. The control group (n = 16) was given 30 minutes of independent suture practice, while the experimental group (n = 14) utilized the suture guidance application. Both groups completed a pre- and post-test wound closure assessment. After the post-test, the control group trialed the suture guidance application. All participants completed a feedback survey on the application. Statistical analysis was completed using Stata (StataCorp., College Station, TX, USA) with paired Student's t-tests and Welch's t-tests with a significance of 95%. Results Both groups demonstrated a significant improvement in total time and time per stitch during the post-test. Additionally, comparing pre- and post-test assessments in the experimental group revealed a significant improvement in the total number of stitches (p = 0.007), the ratio of bisecting stitches (p = 0.02), and the symmetry of stitch bite (p = 0.03). The feedback survey supported the application for guiding suture placement and spacing. Participants identified limitations in the hologram stability and neck positioning. Conclusions This study suggests the potential to use AR to facilitate the independent practice of wound closure within simulation environments.

Comparison of pre- and post-implantation of Indonesian-made plates in fracture patients: Functional, radiological, biomechanical and chemical analyses.

Bone implants are important in the recovery of fractures and degenerative diseases. Although many implants have been marketed, study on Indonesian-made plates is still limited. The aim of this study was to assess the patients' functional and radiological improvements and biomechanical and chemical changes of Indonesian-made plates used in long bone fractures. retrospective study was conducted at Semen Gresik Hospital, Gresik, Indonesia. This study included adult patients with long bone fractures who had surgeries with Indonesian plates. Functional improvement (assessed using disabilities of arm, shoulder, and hand (DASH) or lower extremity functional scale (LEFS)) and radiological data (assessed using radiographic union score (RUS)) were assessed in week 4 and month 6, 12, and 15 after surgery. Biomechanical changes (hardness and roughness test) and chemical analysis were assessed after 15 months of use. The normality of the data was tested with Shapiro-Wilk while data analysis was conducted using paired Student t-test or Friedman test as appropriate with type of data. Our data indicated that the DASH and LEFS functional scores had significant improvement over the follow-ups indicating functional recovery. RUS scores also improved over time, indicating a good healing process. Hardness tests on post-surgery implants showed a decrease in hardness of 7.3% and an increase of 3.3% in roughness. Chemical analysis showed a reduction in chemical levels in the implant of 7.8%, indicating durability and minimal toxicity. This study highlights that Indonesian implants have been proven safe to use in fractures. Further examinations with a larger sample and a longer duration of monitoring are recommended for stronger validity.