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Medical Research Archives

Knowledge Enterprise Journals

Preprints posted in the last 30 days, ranked by how well they match Medical Research Archives's content profile, based on 11 papers previously published here. The average preprint has a 0.02% match score for this journal, so anything above that is already an above-average fit.

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Segmental Lung Sound Analysis in Obstructive Lung Diseases Using Electronic Stethoscope; a protocol to establish an acoustic repository

Anuradha, H.; Yasaratne, D.; GMRI, G.; Parakrama, E.; Severin, R.

2026-05-28 respiratory medicine 10.64898/2026.05.27.26354263 medRxiv
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Introduction Obstructive lung diseases (OLDs) are responsible for high rates of illness and death worldwide. Inflammation, chronic airflow limitation, and bronchial remodeling occur in OLD and eventually result in the unique respiratory sounds. Despite its subjective and having low reproducibility, still traditional auscultation using a manual stethoscope is the main method used to identify the lung sounds. Nevertheless, the combination of recent advancements in digital stethoscopes and AI (Artificial Intelligence) has permitted the objective measurement of lung sounds. Nevertheless, there is a lack of standardized, region-specific databases for AI training and validation. Even though lung sound classification is an emerging aspect in research and telerehabilitation the lobar wise acoustic pattern is still novel due to lack of prevailing database to train AI models. Identifying this gap this study aims to develop an acoustic repository and analyze the data using segmental lung sounds from patients with OLDs and healthy controls through an electronic stethoscope. Methods and analysis This is a cross sectional observational study involving 120 participants (60 OLD patients and 60 healthy controls). Lobar wise acoustic signals will be captured using an electronic stethoscope in healthy and diseases population. The data will be analyzed using Audacity software for annotations and then it will be used for feature extraction and statistical analysis. The acoustic features extracted through Audacity, will include frequency, intensity, pitch, and root mean square (RMS) energy. Repeated measures ANOVA will be applied to compare mean sound intensities across lung segments while Pearson correlation will be used to assess associations with body composition parameters. The data will then be standardized for AI-based diagnostic applications. Ethics and dissemination The study is being reviewed from the Ethics Review Committee, Faculty of Medicine, University of Peradeniya (2025/EC/87) will be sought. Informed consent will be obtained in writing. The dissemination of results will take place through peer-reviewed publications and the creation of a public database containing lung sounds from the region.

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A historical specimen of False Lingzhi (Ganoderma lucidum) resolves a 245-year-old confusion within an important medicinal mushroom group

Varga, T.; Parker, S. R.; Agorini, A.; Dombrowski, A.; Hadfield, L.; Ainsworth, A. M.; Hawksworth, D. L.; Ghobad-Nejhad, M.; Papp, V.

2026-05-14 evolutionary biology 10.64898/2026.05.13.724775 medRxiv
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O_LIPlants and fungi are major sources of natural products beneficial to society, making the study of distinct species essential for discovering new drugs and bioactive compounds. The medicinal mushroom "Lingzhi" or "Reishi" (Ganoderma lingzhi) is widely used in traditional medicine and extensively studied for its bioactive triterpenoids, yet it is commonly identified as Ganoderma lucidum, the type species of the genus, which lacks a type specimen. C_LIO_LIWe sequenced a G. lucidum specimen preserved in the Kew fungarium, which agreed with the original description and was collected from wood of Corylus avellana in southern England. Using this reference specimen, we compiled genomic and ITS barcoding datasets to explore the genetic and geographic variation within this species. C_LIO_LIWe showed that G. lingzhi and G. lucidum diverged more than 12 million years ago and that all seven "G. lucidum" genomes deposited in public databases belong to other species. More than 1000 barcoding sequences showed that the widely used homology-based ITS barcoding is not working in this group, which can be mitigated by a phylogenetic placement approach. The 149 sequences assigned to G. lucidum with high confidence showed a Eurasian distribution and introductions to North and South America and Africa. C_LIO_LIOur study underscores the importance of accurate species identification and provides guidance for a group of pharmaceutical and socially significant species. To further support future studies and the wider public in differentiating between G. lingzhi and G. lucidum, we propose using "False Lingzhi" as the English name for G. lucidum. C_LI Societal Impact StatementTraditional Chinese Medicine has expanded far beyond Asia, with growing markets in North America and Europe for supplements and functional foods. Lingzhi or Reishi (Ganoderma lingzhi), a well-known medicinal mushroom, is valued for its anti-inflammatory and anticancer properties. However, it is often misidentified with species that may not provide the same health benefits. This confusion poses risks to consumer safety, product regulation, and research. Here, we establish a reference using morphological and molecular tools for the most commonly misidentified species (Ganoderma lucidum) and propose the name "False Lingzhi" to distinguish it, supporting accurate identification, safer product development, and reliable research.

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Exploring the Relationship Between Acute Respiratory Illnesses, blood inflammatory biomarkers, and Acute Cardiac Events through a cross-sectional study

Aleem, M. A.; Macintyre, C. R.; Rahman, B. A.; Rahman, M. Z.; Rahman, M. A.; Islam, A. K. M. M.; Ghosh, P. K.; Akhtar, Z.; Chowdhury, F.; Qadri, F. A.; Chughtai, A. A.

2026-05-20 respiratory medicine 10.64898/2026.05.15.26353350 medRxiv
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Introduction Recent respiratory illness, especially influenza, may trigger acute cardiac events via elevated inflammatory mediators. During the 2018 influenza season in Bangladesh, this study examined whether recent acute clinical respiratory illness (CRI) or laboratory-confirmed influenza was associated with elevated hs-CRP and IL-6, linked to acute cardiac events. Methods A total of 139 participants aged [&ge;]40 were recruited from a Dhaka cardiac hospital: 70 with acute myocardial infarction (AMI), 30 with other acute cardiac events, and 39 healthy individuals. CRI was defined as fever with cough and/or respiratory symptoms within seven days. Respiratory swabs were tested for influenza, and blood was analyzed for hs-CRP and IL-6. Results Median hs-CRP and IL-6 were higher in participants with CRI or influenza but not significantly. Cardiac patients had elevated hs-CRP (9.98 mg/L in other cardiac; 4.86 mg/L in AMI vs. 1.73 mg/L in healthy) and IL-6 (0.1 pg/mL in other cardiac; 0.145 pg/mL in AMI vs. 0.08 pg/mL in healthy) (p<0.001). CRI was not significantly associated with elevated hs-CRP or IL-6, though influenza in healthy participants was linked to higher IL-6. Cardiac patients had a higher risk of hs-CRP [&ge;]3 mg/L and elevated IL-6. Conclusion Cardiac patients showed significantly increased inflammatory markers, but CRI was not clearly linked to inflammation. Further research should assess biomarker utility for early cardiac risk.

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The Effect of Vaccination on the Evolution of the SARS-CoV-2 B.1.351 Variant

Wang, Z.; Raeihle, M.; Braun-Gorman, S.; Leung, I.; Richards, C.; Gabbay, L.; Shamoon-Pour, M.

2026-05-08 molecular biology 10.64898/2026.05.06.723356 medRxiv
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Since the initial distribution of the SARS-CoV-19 vaccine, its widespread use has been hypothesized to act as a selective pressure that drives the COVID-19 virus to mutate. This study aims to investigate the correlation between global vaccination rates and the mutation rate of the SARS-CoV-2 Beta variant (B.1.351). From January to July 2021, nucleotide diversity increased in tandem with vaccination rates, demonstrating that the virus evolved more rapidly in response to selective pressure from mass vaccination. Statistical analysis revealed statistically significant positive correlations between both vaccination rates and vaccine doses administered with nucleotide diversity. Thus, our findings indicate a positive correlation between rising vaccination rates and nucleotide diversity, suggesting that increased vaccination coverage acted as a selective pressure that accelerated viral evolution of SARS CoV2.

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Cigarette Smoke Extract (CSE) reduces expression of functional TRPV4 channels in primary human bronchial epithelial cells differentiated at an Air Liquid Interface (ALI) in vitro

Mueller, I.; Alt, P.; Gudermann, T.; Kiefmann, M.; Dietrich, A.

2026-05-22 cell biology 10.64898/2026.05.20.726480 medRxiv
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Primary human bronchial epithelial cells (pHBECs) of the airways of smokers are chronically exposed to cigarette smoke, which may induce chronic obstructive pulmonary disease (COPD) ranked fourth among the most common global causes of death. Using an established protocol for differentiation of pHBECs to a pseudostratified epithelium at an air liquid interface (ALI), we analyzed functional expression of transient receptor potential vanilloid 4 (TRPV4) proteins after application of cigarette smoke extract (CSE), which upregulated seven smoke exposure regulated genes (SERGs). TRPV4 protein expression in the plasma membrane and localization next to the cilia of ciliated cells was reduced, while cell barrier function was not altered after chronic exposure to CSE for 28 days compared to untreated control cells. Accordingly, TRPV4-mediated Ca2+ influx was blocked in pHBECs after CSE exposure. Moreover, Os-9 protein, which after binding mediates protection from degradation of TRPV4 protein by polyubiquitination, was significantly less expressed in pHBECs upon CSE exposure. Most interestingly, overexpression of OS-9 in pHBECs rescued reduced TRPV4 protein levels induced by CSE. Our study identifies a novel molecular mechanism of toxicity by CSE interfering with TRPV4 and OS-9 expression in pHBECs, which may blaze the trail for new therapeutic options in COPD.

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Computational drug repurposing identified Artemisinin and Mebendazole as potential inhibitors of virulence-associated proteins SKSR and essential kinases CpCDPK1 of Cryptosporidium parvum

Parveen, ; Saini, D.; Kumar, M.; Kapinder, ; Singh, A.; Jamil Khan, N.; Manzoor, N.; Sharma, M.; Kumar, P.

2026-05-19 molecular biology 10.64898/2026.05.17.725751 medRxiv
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Cryptosporidium parvum is a protozoan parasite responsible for cryptosporidiosis, significantly threatening immunocompromised individuals, particularly HIV/AIDS patients, by causing severe diarrhea and potential mortality. Current treatments are largely ineffective, prompting investigations into new therapeutic options. This study evaluated two antiparasitic drugs: Mebendazole, used for helminth infections, and Artemisinin, used for malaria. The SKSR gene family encodes virulence factors in C. parvum, and Calcium-dependent protein kinase1 (CpCDPK1) regulates the life cycle of C. parvum; targeting these proteins may reduce growth and infection in hosts. In the current study, molecular docking was conducted taking Mebendazole and Artemisinin drugs as ligands, SKSR gene family and CpCDPK1 proteins as drug targets. Results with SKSR showed binding energy of -4.9 kcal/mol, -6.72 kcal/mol for Mebendazole and Artemisinin, respectively. Whereas, with CpCDPK1, the binding energies were -6.44 kcal/mol, -9.18 kcal/mol for Mebendazole and Artemisinin, respectively. Docking of Nitazoxanide (an in-use drug for C. parvum) with SKSR and CpCDPK1 revealed binding energies -4.2 kcal/mol, -4.81 kcal/mol, respectively. The stability of the proteins (targets) upon binding to the ligands was assessed by performing all-atom MD simulations for 100ns using the GROMACS package. No major variations were observed upon binding of Artemisinin and Mebendazole to SKSR and CpCDPK1. The findings of MD simulations imply that both proteins maintain their stability upon binding of Artemisinin and Mebendazole. Molecular Docking and MD simulation studies suggest that Artemisinin and Mebendazole are potential candidates for repurposing in the treatment of C. parvum infections, with recommendations for in vitro studies to validate these findings.

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Origins of eukaryotic metabolism

Santana-Molina, C.; Spang, A.; Snel, B.

2026-05-12 evolutionary biology 10.64898/2026.05.08.723234 medRxiv
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The origin of eukaryotes is a key event in the evolution of cellular life hypothesized to involve a symbiotic integration between a member of the Asgard archaea and the Alphaproteobacteria. Recent work has provided evidence for additional genetic input from other prokaryotes to the eukaryotic proteome yet the extent and sources of these contributions remain debated. Here we aimed to further resolve the prokaryotic origins of eukaryotic genes to inform our understanding of eukaryogenesis. Specifically, we developed a phylogenetic framework to investigate the origins of eukaryotic gene families associated with metabolism and informational processing for comparison. We found that informational processing genes were predominantly derived by archaea whereas eukaryotic metabolism is highly chimeric in its origin. In contrast to previous studies, we report a substantial number of archaeal origins of diverse metabolic enzymes including key metabolic regulators. This highlights an overlooked participation of archaeal metabolism and pinpoints potential metabolic integrations during eukaryogenesis. Apart from the alphaproteobacterial contributions to the eukaryotic metabolism, we found an additional dominant phylogenetic signal of genes potentially derived from Myxococcota, especially for gene families associated with lipid metabolism. By systematically analysing the origins of eukaryotic metabolism, this research offers novel insights into the origin of eukaryotic membranes and refine our current models for the origin of the eukaryotic cell.

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Outbreak of H9N2 avian influenza viruses in lesser rhea in Peru, June-July 2025

Garcia-Glaessner, A.; Crespo-Bellido, A.; Munoz-Saavedra, B.; Juarez, D.; Barrera, P.; Salmon-Mulanovich, G.; Checahuari-Jarata, S. E.; Cruz, D.; Huisa-Balcon, D. X.; Idme, G.; Nelson, M. L.; Lescano, J.; Leguia, M.

2026-05-13 evolutionary biology 10.64898/2026.05.08.723762 medRxiv
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Avian influenza viruses (AIVs) are endemic in the Americas and responsible for outbreaks in both domestic and wild birds that occasionally spill over into humans. We report the first known outbreak of AIV H9N2 in lesser rhea (Rhea pennata), also known as Darwins rhea, in the region of Puno-Peru. The animals in this study lived in an isolated conservation center located in remote highlands above 4,000 m.a.s.l. Between June and July 2025, a total of 46/92 animals were recorded sick, with symptoms including greenish diarrhea (100%), hyporexia (24%), dyspnea (76%), nasal discharge (42%), drowsiness (18%) and isolation from the flock (73%), and 94% later died. Gross pathology exams revealed septicemia characterized by severe hepatitis, pneumonia, tracheitis, enteritis, and encephalitis. Swab and necropsy samples tested positive for Influenza A by PCR and were later identified as H9N2 through whole genome sequencing. We generated complete H9N2 genomes for two individuals. No additional pathogens were found. Phylogenetic analysis across all eight segments revealed that the viruses were low pathogenicity H9N2 AIV strains of North American origin, which indicated this outbreak was a new introduction of the virus into South America. We also performed a comparative mutational analysis and identified multiple mutations previously associated with mammalian host adaptation, increased virulence, increased pathogenicity, and increased virus binding to 2-6 receptors, which may explain the high mortality rates observed despite the supposedly low pathogenicity of the strain. We also identified novel mutations specific to rhea viruses that will need to be experimentally validated. This is the first report of a natural H9N2 systemic infection in an avian host, highlighting a need for increased surveillance efforts for zoonotic influenza viruses with pandemic potential. Author SummaryAvian influenza viruses (AIVs) are endemic in the Americas and cause more than 7,600 infections annually in domestic and wild birds worldwide each year. We report detection of AIV H9N2 in lesser rhea during an outbreak that occurred in June-July 2025 in the Andean highlands of Puno in Peru. Multiple sick animals were reported with symptoms of respiratory and gastrointestinal disease and 94% of them later died. Samples collected tested positive for Influenza A and they were subtyped as H9N2 of low pathogenic origin from North America. This is the third time H9N2 enters South America from North America, presumably through wild birds, some of which migrate along the Pacific Flyway. Comparison with other H9N2 sequences revealed a total of 44 mutations of interest that may explain the elevated death rates observed. Surveillance in wild birds remains patchy at best and needs to be strengthened in order to prevent spillover events into other animals, including humans.

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Molecular epidemiology of the globally spreading genetic lineage IV of peste des petits ruminants virus

Courcelles, M.; Tounkara, K.; Mantip, S.; Niang, M.; Kounta Sidibe, C. A.; Sery, A.; Dakouo, M.; Luka, P. D.; Adedeji, A.; Shamaki, D.; Muhammad, M.; Ali, Y. H.; Saeed, I. K.; Awuni, J.; Odoom, T.; Tetteh, P. A.; Yingar, D. T.; Wade, A.; Dickmu, S.; Diddi, A.; Shawash, H.; Couacy-Hymann, E.; Mathurin, K. Y.; Ouled Ahmed Ben Ali, H.; Ben Hassen, S.; hadouchi, s.; Alm-ajali, A.; Settypalli, T. B. K.; Lamien, C. E.; Salami, H.; Rassoul, S.; Asnaoui, M.; Cetre-Sossah, C.; Guendouz, S.; Kwiatek, O.; Libeau, G.; Dundon, W. G.; Bataille, A.

2026-05-18 evolutionary biology 10.64898/2026.05.18.725933 medRxiv
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Peste des petits ruminants (PPR) is a highly contagious viral disease of small ruminants caused by the peste des petits ruminants virus (PPRV), which is classified into four distinct genetic lineages (I-IV). A critical concern in the recent epidemiological history of PPRV is the rapid and widespread expansion of lineage IV (LIV) across West Africa over the past decade. This dominance suggests a potential adaptive advantage of circulating LIV strains in the regions current epidemiological context. In this study, we obtain the genome sequence of 26 new PPRV samples, including historical (pre-2000) and many recent African LIV isolates, offering the first opportunity to investigate the evolutionary history of LIV in Africa and identify genetic events potentially associated with its recent spread. Phylogenomic analyses implemented on a dataset of 167 curated PPRV genome sequences reveal that the most ancestral LIV group comprises strains circulating in Sub-Saharan Africa (designated clade LIVssa), providing robust evidence for an African origin of lineage IV. Our results further indicate that PPRV strains linked to the recent West African expansion of LIV belong to a specific LIVssa subgroup, termed NigB. We identified multiple signatures of selection pressure within the LIVssa sublineage, particularly in the NigB cluster. Several amino acid substitutions unique to LIVssa or NigB were detected, some of which may impact protein function and warrant prioritised investigation. Additional genomic data are required to confirm the association between the NigB group and the ongoing spread of LIV in West Africa. The evolutionary adaptations observed in LIVssa - potentially enhancing transmission efficiency, host range or pathogenicity - could undermine current disease control strategies in regions where PPR poses significant threats to food security and local economies. Author SummaryPeste des petits ruminants virus (PPRV) infects sheep and goats across Africa, Middle East, Asia and Europe, causing disease with major impact on global economy and food security. One genetic lineage of PPRV, called lineage IV (LIV), is at the origin of most recent expansion of the distribution of the disease, including replacement of other lineages in areas of African where PPRV is historically present. Here, we generated genome sequences from PPRV LIV isolates from different dates and places to study the evolution of this genetic lineage and explore whether its recent spread can be associated with the appearance of new mutations in the virus genome. Our results provide evidence that the PPRV LIV originated in Sub-Saharan Africa and identify mutations present only virus isolates currently spready in new regions of Africa. Further research should investigate the impact of these mutations on protein functions and capacity of transmission of PPRV.

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Disability, Fatigue, and Mental Health in Acute versus Chronic Spinal Pain Patients in the Gaza Strip: A Comparative Cross-Sectional Study

Salama, M.; Najim, A.; Shabana, M.; Almukbel, R.; Mokbel, K.

2026-05-15 rehabilitation medicine and physical therapy 10.64898/2026.05.12.26353046 medRxiv
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Background: Spinal pain, including neck pain and low back pain (LBP), is a common musculoskeletal condition and major contributor to disability worldwide. Evidence comparing disability, fatigue and mental health across acute and chronic stages remains limited, particularly in conflict-affected and low-resource settings. This study assessed these outcomes among patients with acute and chronic neck pain and LBP in the Gaza Strip. Methods: A comparative cross-sectional study was conducted among 410 adults attending outpatient physical therapy at Nasser Medical Complex, Khan Younis, Gaza Strip. Participants included 204 with neck pain and 206 with LBP, classified as acute neck pain (n=101), chronic neck pain (n=103), acute LBP (n=102) and chronic LBP (n=104). Disability, fatigue, psychological distress and sleep disturbance were assessed using the Neck Disability Index (NDI)/Oswestry Disability Index (ODI), Fatigue Severity Scale (FSS), Patient Health Questionnaire-4 (PHQ-4) and PROMIS Sleep Disturbance Short Form 8a. Independent t-tests, adjusted linear regression, correlation analyses, clinical-threshold analyses and binary logistic regression were performed. Results: Chronic neck pain and chronic LBP were associated with significantly higher disability, fatigue and psychological distress than acute pain. Chronic neck pain patients had higher NDI, FSS and PHQ-4 scores than acute neck pain patients; chronic LBP patients had higher ODI, FSS and PHQ-4 scores than acute LBP patients (all p<0.001). Sleep disturbance did not differ significantly between groups. Female participants reported higher psychological distress in both pain groups, with higher fatigue in neck pain and higher disability in LBP. Adjusted analyses confirmed that chronic pain status remained associated with higher disability, fatigue and psychological distress. Fatigue was the most consistent factor independently associated with chronic pain status. Conclusions: Chronic spinal pain was associated with greater disability, fatigue and psychological distress than acute spinal pain, while sleep disturbance was common across groups. These findings support early multidimensional assessment, including screening for fatigue and psychological distress. Longitudinal studies are needed to clarify whether these factors contribute to transition from acute to chronic spinal pain.

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A2 and A1B in vitro milk digests: effects on in vitro leaky gut model and adipose cells

Perugini, J.; Bendinelli, P.; Scopini, E.; Galli, C.; Cattaneo, S.; Bonfatti, V.; Cinti, S.; Finco, A.; De Noni, I.; Giordano, A.; Ferraretto, A.

2026-05-13 molecular biology 10.64898/2026.05.09.723973 medRxiv
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Obesity is associated with chronic low-grade systemic inflammation of adipose tissue and is often linked to intestinal epithelial barrier (IEB) dysfunction. The present study aimed to evaluate the effects of in vitro gastrointestinal digests of bovine milk containing A1B or A2 {beta}-casein variants on leaky IEB and adipocyte inflammation. Digests of A1B (DA1B) and A2 (DA2) milk were administered to an in vitro Caco-2/HT-29 intestinal cell co-culture mimicking a leaky gut. Intestinal absorbed fractions derived from A1B (MA1B) and A2 (MA2) were administered to hMADS adipocytes. DA1B and DA2 did not modify intestinal permeability, either in the absence or the presence of inflammation. DA1B reduced Claudin-1 mRNA, as well as zonula occludens-1 mRNA and protein expression. Both DA1B and DA2 increased interleukin-8 expression, but only DA1B increased tumor necrosis factor-. In human adipocytes, MA1B, and to a lesser extent MA2, increased the expression of pro-inflammatory markers monocyte chemoattractant protein-1 and interleukin-6, while reducing adiponectin levels. DA2 preserved in vitro leaky IEB integrity and exhibited a lower inflammatory potential in both leaky gut and adipocytes compared to DA1B. This study is the first to establish a link among A2 milk, leaky gut syndrome, and obesity.

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Cardiac Mitochondrial Dysfunction Following Bleomycin-Induced Acute Lung Injury in Rats

Wilcox, R. M.; Ngu, A. K.; Jiang, I.; Nielsen, G. K.; Pellegrino, P. R.; Wang, H.

2026-05-11 molecular biology 10.64898/2026.05.06.723353 medRxiv
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BackgroundAcute lung injury (ALI) and acute respiratory distress syndrome (ARDS) are frequently associated with cardiac complications, including myocardial injury and right ventricular dysfunction. However, the mechanisms linking pulmonary injury to cardiac dysfunction remain incompletely understood. In this study, we investigated ventricular mitochondrial respiratory function during the acute phase of bleomycin-induced ALI. MethodsALI was induced in male and female rats by intratracheal bleomycin (2.5 mg/kg); saline served as a control. Circulating cardiac troponin I (cTnI) was measured as an indicator of myocardial injury. Mitochondrial respiration was assessed in permeabilized ventricular fibers using high-resolution respirometry (HRR). The mitochondrial respiration rate of the H9C2 cardiomyoblast cell line was performed using Seahorse Xfe96 Cell Mitochondrial Stress Test. Cells were treated with pro-inflammatory cytokine cocktails (PRO; IL1{beta} plus TNF plus IL6), anti-inflammatory cytokine cocktails (ANTI; IL4 plus IL10), a mixture of PRO and ANTI (BOTH), and (-)-norepinephrine (NE) in either hypoxic (1% oxygen) or normoxic conditions. ResultsBleomycin-induced ALI increased circulating cTnI levels in male rats, indicating early cardiac stress following lung injury. Mitochondrial respiration in the LV appeared to show modest alterations, with preserved oxidative phosphorylation (OXPHOS) and electron transport (ET) capacity. In contrast, the RV of male animals demonstrated marked reductions in absolute respiratory flux and substrate-supported OXPHOS capacity, indicating impaired mitochondrial oxidative capacity. Female animals exhibited greater preservation of mitochondrial respiratory function, particularly in the RV, with higher OXPHOS capacity and greater Complex I gain than males. H9C2 cells treated with PRO showed a significant increase in uncoupled respiration following 6- and 24-hour incubation periods, under normoxic conditions. Maximal respiration and spare respiratory capacity were increased following 24-hours under hypoxia. No significant changes were observed following treatment with NE alone and in combination with PRO under normoxia or hypoxia for 24 hours. ConclusionsALI induces ventricle-specific and sex-dependent alterations in cardiac mitochondrial bioenergetics, with pronounced impairment in males and relative mitochondrial resilience in females. In H9C2 cardiomyoblasts, short-term exposure (6-24 hours) to pro-inflammatory cytokines enhances uncoupled mitochondrial respiration under normoxic conditions, while short-term hypoxic exposure independently increases maximal respiration and spare respiratory capacity.

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Fecal untargeted metabolomic and short-chain fatty acid analyses in cats with chronic kidney disease

Schmidt, T.; Quimby, J.; Whitehouse, W. H.; Aronson, L.; Suchodolski, J. S.; Li, Q.

2026-05-14 molecular biology 10.64898/2026.05.12.724333 medRxiv
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BackgroundThe gut-kidney axis plays a direct role in gastrointestinal and kidney health. Gut-derived metabolites like uremic toxins are associated with the pathophysiology of feline chronic kidney disease (CKD). The aim of the study was to identify novel fecal biomarkers and investigate the roles of gastrointestinal metabolites in feline CKD. ResultsFecal samples from 41 healthy non-CKD (control) and 67 CKD cats, including 5 IRIS stage 1 (CKD1), 37 stage 2a (CKD2a), 18 stage 2b (CKD2b), and 7 stage 3 (CKD3), were subject to fecal untargeted metabolomics and targeted short-chain fatty acid (SCFA) analyses. Multiple linear regression, adjusted for sex, age, body weight and study site, identified 64 differential metabolites between control and across CKD groups (P<0.0001 and FDR<0.10). Approximately 65% of the metabolites were lipids, including polyunsaturated long-chain fatty acids, acylcarnitines, and ceramides. Random Forest algorithm selected N1-methyl-2-pyridone-5-carboxamide (2PY), a uremic toxin from nicotinamide catabolism, as the top fecal marker for classifying feline CKD. Fecal 2PY was increased in CKD1 (P = 0.03), CKD2a, CKD2b, and CKD3 (all P<0.0001) compared to the controls. Data mining revealed serum concentration of 2PY was significantly increased with severity of CKD in cats, possibly due to impaired renal excretion. Cholesterol and arachidonic acid, markers for enterocyte shedding and inflammation, were increased in CKD3 versus control (both P<0.05). In healthy non-CKD cats, evident suggested fecal lipids increased with age (P<0.0001), and were higher in females versus males (P<0.0001). While fecal indole and p-cresol were increased in CKD3 versus control (both P<0.05), no change was observed in indoxyl sulfate (IS) or p-cresol sulfate (PCS). Fecal indole-3-acetic acid (IAA) was decreased in several CKD groups compared to the controls (all P<0.05). Finally, two branched SCFAs, isobutyrate and isovalerate, were increased in CKD3 versus control (both P<0.05). ConclusionsThe study revealed 2PY as a novel marker and unveiled profound alterations in intestinal lipid compositions with a potential link to gut barrier integrity and inflammation in CKD.

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Hydrocephalus caused by Katnip deletion is linked to increased ciliogenesis and reduced proliferation of neuroprogenitor cells

Limerick, A.; Chu, C. Y.; Turner, J. S.; Brautigan, D. L.; Xu, W.; Fu, Z.

2026-05-05 cell biology 10.64898/2026.05.01.722314 medRxiv
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BackgroundKATNIP (Katanin-interacting protein), also known as KIAA0556, is one of the human genes with pathogenic variants linked to Joubert syndrome, an archetypal neurodevelopmental ciliopathy. KATNIP is a scaffolding protein with a critical role in ciliogenesis. In this study, we characterized the ciliopathy phenotypes due to KATNIP gene deletion. ResultsWe produced a Katnip null mouse model using CRISPR-Cas12a (Cpf1). The null heterozygotes appeared normal while the homozygotes died around postnatal day 9, showing severe hydrocephalus and deficiency in neuroprogenitor cell proliferation. Katnip-deficient cells in the brain have a higher rate of cilia formation and longer cilia than wild type cells. ConclusionKATNIP loss of function gives rise to hydrocephalus found in Joubert syndrome. The results indicate that KATNIP restricts ciliogenesis and cilia extension and supports proliferation of neuroprogenitor cells in the brain.

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Exploring Auditory Biofeedback Paradigms for Gait Training in Children with Cerebral Palsy: A User-Centered Design Study

Kantan, P. R.; Hansen, M. B.; Foldager, J. J.; Fjeldgaard, F. S.; Dahl, S.; Spaich, E. G.

2026-05-29 rehabilitation medicine and physical therapy 10.64898/2026.05.29.26353852 medRxiv
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Purpose: To identify, through iterative user-centered design, the auditory biofeedback requirements and sound preferences supporting gait training in children with cerebral palsy (CP), and to determine which feedback variables, sound mappings, and sound types yield clinically viable and movement-interpretable paradigms. Methods: The iterative process spanned two prototype phases. Prototype A comprised seven paradigms demonstrated to two experienced physiotherapists (Workshop 1A). Two of these were subsequently discarded owing to poor sound-movement interpretability and two were modified. Six paradigms were added to Prototype B, demonstrated to four children, five parents, and one therapist (Workshop 1B) and two therapists (Workshop 2B). Data were analyzed using systematic text condensation. Results: Within-child sound preferences varied with energy level and sensory state on a given day. Sound-movement interpretability tended to suffer for paradigms with greater acoustic complexity (e.g. computer-generated music). Therapists endorsed a repertoire spanning both movement quality and movement quantity targets. Participants independently proposed paradigms rewarding restrained and controlled movement, a feedback category absent from the current prototype. Conclusions: Session-level calibration is preferable to fixed sound profiles, requiring real-time interface support for paradigm adjustment. Acoustic complexity must remain subordinate to movement-sound interpretability. Paradigms targeting movement restraint are a development priority unaddressed in the literature.

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Primary Care Providers Journey with OSA Care, Challenges and Strategies: A Qualitative Study

Cho, W.; Cheng, M.; Blades, K.; David, O.; Tsai, W.; Povitz, M.; McBrien, K.; Donald, M.; Pendharkar, S.

2026-05-20 respiratory medicine 10.64898/2026.05.15.26353339 medRxiv
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Purpose: Obstructive sleep apnea (OSA) is a treatable chronic condition associated with significant health and societal consequences. Primary care providers (PCPs) often manage OSA with support from sleep specialists but face challenges navigating a complex system of care. By developing a Journey Map, we sought to identify factors influencing primary care OSA management and the associated PCPs' perspectives and emotions. Methods: Twenty-one Calgary-based PCPs were interviewed as part of a study evaluating a primary care management pathway for OSA. We used conventional content analysis, utilizing inductive coding to define journey phases and deductive coding via the Theoretical Domains Framework (TDF) to identify barriers and enablers. These were then mapped onto journey phases for OSA management to create a Journey Map. Results: The Journey Map included five phases of OSA care. PCPs described feeling neutral during the Learning phase and expressed neutral to positive emotions during the Patient Encounter and Diagnosing OSA phases. In contrast, the Initial Treatment and Ongoing Management phases were associated with neutral to negative emotional experiences. Barriers included limited OSA-related training and education, unclear roles among provider groups, and low patient engagement. Enablers included accessible knowledge resources, a shared key role in OSA screening, and availability of sleep testing. Opportunities to enhance primary care OSA management were identified at each step. Conclusion: This study identified several behavioural factors influencing PCP decision-making across the OSA care continuum. The Journey Map illustrates how high diagnostic confidence of PCPs shifts to escalating challenges and negative sentiment during treatment and long-term management of OSA. Keywords: obstructive sleep apnea; primary health care; health service delivery; process assessments; attitude of health personnel

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microRNA-721 is a host regulator of TNF-IRF1 axis in Leishmania infected macrophage

Zanatta, J. M.; Bahia, I. A. F.; Sousa, E. S. A. d.; Teixeira, C. A.; Kato, K. T.; Bento, C. A.; Acuna, S. M.; Lima, M. R. D.; Silvestre, R.; Fonseca, D. L. M.; Muxel, S. M.

2026-05-16 immunology 10.64898/2026.05.13.724987 medRxiv
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MicroRNAs (miRNAs) are small noncoding RNAs that play critical roles in regulating immune responses and have emerged as potential biomarkers and therapeutic targets in complex diseases. Leishmaniasis is a neglected disease that compromises host immunity and is associated with challenging treatments regimens. Leishmania amazonensis (L. amazonensis), an intracellular protozoan parasite, causes cutaneous leishmaniasis by replicating inside mammalian macrophages to establish infection. In this context, miRNAs have emerged as vital post-transcriptional factors that regulate the inflammatory landscape during infection. In this study, we aimed to analyze the function of miR-721 in macrophages during L. amazonensis infection by integrating in silico miR-721 target prediction with RNAseq data from macrophages of two distinct mouse genotypes, resistant C57BL/6 and susceptible BALB/c. We found that miR-721 is induced in macrophages infected with L. amazonensis, but is not in LPS-stimulated macrophages, suggesting a TLR4-independent activation. Integrating miR-721 target prediction with comparative transcriptomic analyses in resistant C57BL/6 and susceptible BALB/c models revealed the TNF-IRF1 axis as a primary miR-721-associated regulatory network. Specifically, miR-721 is predicted to target the 3UTRs of Tnf and Irf1 to suppress the inflammatory response. Functional inhibition of miR-721 successfully restored Tnf and Irf1 expression and reduced the amastigote burden over 24 hours. Furthermore, we showed that the miR-721/TNF-IRF1 axis regulates downstream genes associated with macrophage response, such as Serpine1, Csf1, Cd69 and Maf. Our work demonstrated that Leishmania induces miR-721, which negatively modulates the TNF-IRF1 axis, thereby suppressing the immune response and favoring parasite persistence. While C57BL/6 macrophages exhibit a robust activation of the TNF-IRF1 network, promoting inflammatory response, BALB/c macrophage showed a breakdown of this network. This was associated with post-transcriptional suppression of inflammatory responses, thereby favoring parasite persistence. These findings link miR-721 to the establishment of macrophage polarization, providing relevant insights into the mechanisms of parasite subversion of the host immune response.

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Importance and frequency of using esophageal pressure monitoring during ventilatory support. A cross-sectional study

Gimenez, M. L.; Steinberg, E.; Garegnani, L. I.

2026-05-03 emergency medicine 10.64898/2026.04.30.26352166 medRxiv
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BackgroundEsophageal pressure (Pes) measurement has been used successfully over the past half-century to delineate the respiratory systems physiology and mechanics. However, there is no information about the importance of Pes monitoring in different scenarios. We aimed to assess the importance and frequency of Pes monitoring in different scenarios according to health professionals and its importance in decision-making. MethodCross-sectional study with an international survey. We included healthcare professionals dedicated to patients receiving invasive and non-invasive ventilation without limits of age, gender, experience and seniority in the position or country of residence. We used non-probabilistic snowball sampling. ResultsWe included 152 participants, with 54.61% (83) males. The response rate to the survey questions ranged from 100% to 71.71%. Of the included participants, 91/139 (65.47%) were respiratory therapists, and 31/139 (22.30%) were Physicians. Most participants worked in mixed ICU. 109/121 (90.08%) participants considered Pes monitoring very important or extremely important for teaching or research. Only 32/112 (28.57%) reported using Pes frequently for these proposals. 49/109 (40.50%) participants considered Pes monitoring very important or extremely important during non-invasive ventilatory support. Only 17/112 (15.18%) reported using Pes frequently for these proposals. Regarding MV individualisation in ARDS during total ventilatory support, 94/121 (77.69%) participants considered Pes monitoring very important or extremely important. Only 33/112 (29.46%) reported using Pes frequently in this scenario. 90/121 (74.38%) also considered it very important or extremely important for MV individualisation in obese patients without ARDS, and 108/121 (89.26%) considered it very important or extremely important for MV individualisation in obese patients with ARDS during total ventilatory support. Only 25/112 (22.32%) and 39/112 (34.82%) reported using Pes frequently in these scenarios, respectively. ConclusionsPes monitoring was considered very important or extremely important for most assessed scenarios. Conversely, most participants rarely or never used it, although it changed therapeutic decisions often when implemented.

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N-Acetylcysteine Partially Rescues Heat-Stressed Skeletal Muscle Cells: A Secondary Analysis of Public Data

Oumo, D.; Namasinga, A.; Nambache, B.; Eketu, Y.

2026-05-18 cell biology 10.64898/2026.05.15.725331 medRxiv
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ObjectiveN-acetylcysteine (NAC) is a clinically available antioxidant with potential applications in trauma-induced hypermetabolic states, including burn injury and crush syndrome. However, its effects on heat-stressed skeletal muscle cells remain incompletely characterized. This study conducted a secondary analysis of a publicly available dataset to quantify NACs protective effects against heat-stress-induced cellular damage. MethodsWe re-analyzed a publicly available dataset (Lu J, 2024, Mendeley Data, doi:10.17632/wffrtcgbnx.1) containing 21 observations across three conditions: Control (n=3), Heat Stress only (HS, n=3), and HS with NAC at five doses (0.5-8.0 mM, n=3 per dose). The primary outcome was the protective ratio [(HS+NAC - HS) / (Control - HS)], where 1.0 indicates complete protection. Statistical analyses included one-way ANOVA, post-hoc t-tests with Bonferroni correction, Cohens d effect sizes, and bootstrap confidence intervals. ResultsHeat stress significantly reduced cell viability by 56.3% (Control: 100.0 {+/-} 12.2 vs HS: 43.7 {+/-} 5.1; t(4)=7.37, p=0.002, Cohens d=6.02). NAC demonstrated a biphasic dose-response with maximal protection at 2.0 mM (66.7 {+/-} 14.4), yielding a protective ratio of 0.409 (95% CI: 0.146-0.675), representing 40.9% protection against heat stress damage. The comparison between HS and HS+NAC (2.0 mM) showed a large effect size (Cohens d = 2.12) but did not reach statistical significance (p = 0.060) due to the small sample size. One-way ANOVA confirmed overall group differences (F(2,18)=32.39, p<0.001, 2=0.783). ConclusionsNAC provides partial protection against heat stress-induced skeletal muscle cell damage at 2.0 mM, with a large effect size suggesting clinical relevance despite limited statistical power. These preliminary findings support further investigation of NAC as an adjunct therapy in trauma-induced hypermetabolic states. All analysis code is provided for reproducibility.

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Pulmonary Distribution and Lesion Penetration of Antimicrobials in Patients with Nontuberculous Mycobacterial Disease

Watanabe, F.; Hiramatsu, M.; Kawakami, T.; Oka, T.; Nanami, H.; Shimoda, K.; Hanada, K.; Shiraishi, Y.; Morimoto, K.

2026-05-20 respiratory medicine 10.64898/2026.05.12.26352725 medRxiv
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Background. The intrapulmonary pharmacokinetics of antimicrobial agents used to treat nontuberculous mycobacterial (NTM) pulmonary disease remain poorly characterized, limiting the optimization of dosing regimens. This study characterized the plasma and intrapulmonary pharmacokinetics of azithromycin, ethambutol, rifampicin, clofazimine, and amikacin, as well as their penetration into pulmonary lesion sites. Methods. We prospectively enrolled patients undergoing guideline-based treatment for NTM pulmonary disease who were indicated for surgical resection at a single center in Japan. Drug concentrations were measured in the plasma and lung samples, and analyzed using a population pharmacokinetic model. The lung lesion site, cavity, or nodule/bronchiectatic were evaluated as covariates of the plasma-to-lung partition ratios. Results. Twenty-four patients were enrolled in the study. Antimicrobial agents other than rifampicin and amikacin accumulate in the lungs at concentrations > 40-fold higher than those in the plasma. Notably, the intrapulmonary half-life of ethambutol, which has not been well-characterized to date, is estimated to be approximately 2 months, indicating prolonged retention within the lungs. Evaluation of drug penetration into cavities and nodular/bronchiectatic lesions showed no clearly reduced concentration compared to that of normal lung tissue. However, in the single case where the caseum was obtained, azithromycin, ethambutol, and rifampicin levels exhibited clearly lower concentrations. Conclusions. Ethambutol shows a prolonged intrapulmonary half-life, suggesting sustained lung exposure even with intermittent dosing. The absence of clearly reduced drug penetration into lesion sites suggests that lesion phenotype alone may have limited value in guiding drug selection.