Chemical Senses

Background: Smell testing is increasingly recognized as essential in rhinology practice but remains underutilized because of time constraints and limited clinical resources. This study aimed to evaluate the performance (test-retest reliability, accuracy and test completion time) of a self-administered, digital version of SMELL-RS, a non-semantic test of olfactory resolution (SMELL-R) and sensitivity (SMELL-S). Methodology: We performed a test-retest reliability study in a tertiary care facility. We enrolled 100 subjects with and without smell dysfunction. The primary outcome measures were two replicates of olfactory test scores (SMELL-RS composite score, SMELL-R score, SMELL-S score). The secondary outcome measures were Sniffin Sticks score, test completion time, patient demographics, and other clinical characteristics (clinical symptoms, etiologies). Results: The SMELL-RS composite score was reliable (ICC=0.71; p<0.0001) and correlated with the Sniffin Sticks composite score (r=0.68; p<0.0001). Different etiologies have different magnitudes of smell loss as revealed by the SMELL-RS score. SMELL-S reduces misdiagnosis associated with Sniffin Sticks threshold tests. The average completion time of the olfactory resolution test (SMELL-R) was on average 5.9 minutes (SD=1.9), while the average completion time of the olfactory sensitivity test (SMELL-S) was 5.5 minutes (SD=2.7). This is two to three times faster than the corresponding Sniffin Sticks tests. Conclusions: SMELL-RS is a rapid, fully automated, reliable, and accurate olfactory test suitable for self-administration in a clinical setting.

Taste perception is influenced by stimulus and oral temperature. Change in oral temperature modulates trigeminal neurons. Whether trigeminal thermal sensing interacts with taste is unknown. Here we studied temperature influences on mouse taste preferences and how they could change following silencing of TRPM8 (transient receptor potential melastatin 8) - a thermoreceptor supporting cool and warm temperature coding by trigeminal neurons. Female and male TRPM8 gene deficient and C57BL/6J (B6) control mice (n = 69) entered thermolickometry tests where they sampled taste solutions at cool (15{degrees}C) and warm (30{degrees}C) temperatures during brief-access (10-sec long) exposure trials, which capture oral sensory/tongue control of licking behavior. Taste solutions included innately avoided bitter quinine (0.03 and 0.3 mM) and preferred sugars (sucrose or glucose, 100 and 500 mM). Mice were respectively maintained under water restriction or water-replete conditions during quinine and sugar tests, which were conducted separately. Analyses revealed that 15{degrees}C enhanced, while 30{degrees}C reduced, licks to quinine in both B6 and TRPM8 deficient mice, which responded similarly (p > 0.05). In contrast, licks to static concentrations of sugars trended towards enhancement by 30{degrees}C, compared to 15{degrees}C, in male B6 mice but were suppressed, and inhibited, by 30{degrees}C (p < 0.05) in male TRPM8 deficient mice. This result agrees with prior studies that show warmth normally facilitates sweetness and that 30{degrees}C stimulation of oral tissues becomes anomalously aversive in TRPM8 deficient mice. These data provide initial evidence that TRPM8 thermosensory influences interact with sugar taste preferences, which may reflect a trigeminal-taste cross-modal phenomenon.

A single allele of any of the [~]1100 functional mouse odorant receptor (OR) genes is expressed by mature olfactory sensory neurons (mOSNs) through a poorly understood mechanism of singular gene choice. We were interested in developing an expression system to study OR selection in a mouse embryonic stem cell (mESC) carrying an Olfr151-IRES-CRE knock-in and a CRE-recombination-dependent ROSA26-MTMG reporter. Recombination of the ROSA reporter could not be observed after exposing this mESC to thousands of chemical compounds, including 175 compounds known to interfere with epigenetic regulatory processes nor by transfection with high probability Olfr151 promoter minigenes coexpressing CRE. The only two known regulatory elements that control OR promoters are not olfactory specific. Still, our inability to elicit even leaky CRE recombination in mESCs suggests that a specific transcriptional machinery within the OSN lineage is needed to drive OR promoter activation. Author SummaryThe Olfr151 promoter is inactive in mESCs.

The nasal epithelium is a complex tissue composed of both respiratory and olfactory tissue, and is constantly exposed to environmental insults, including toxins and pathogens. The main olfactory epithelium (MOE) serves as the critical site for olfaction, or sense of smell. Dysfunction at this critical barrier tissue can result in partial or total loss of olfactory function, resulting in significant impact to quality of life. The MOE is heterogeneous, comprised of many cell types including olfactory sensory neurons, support cells, and immune cells. It is not well understood how these diverse cell types in the MOE interact to regulate this tissue during homeostasis, and during times of injury and inflammation. We investigated how environmental olfactory exposures impact cell type specific transcriptional responses in the mouse MOE. We performed single-cell RNA sequencing (scRNA-seq) of the MOE following controlled environmental exposure to both well-known odorants and allergens. We identified major cell types and subtypes within the MOE, and identified transcriptional changes in response to the olfactory exposures. We identified transcriptional changes in OSNs, sustentacular cells, and resident immune cells to each condition. This indicated that environmental olfactory exposures drive changes to multiple cell types in the MOE. To our knowledge, this is the first study to identify effects of environmental olfactory exposures on cell-type specific transcription at homeostasis. These findings highlight the potential importance of multi-cellular interactions and communication in regulation of the olfactory epithelium.

Male odor induces various behavioral and physiological responses across the reproductive cycle in female mice. Although male odor preference in females is reduced during pregnancy, how it changes across later stages of the reproductive cycle, including nursing and weaning, remains unclear. Here, we found that male odor preference is lost during pregnancy and nursing. To identify the olfactory systems involved in these changes, we examined neural activity using c-Fos immunohistochemistry. Male odor exposure during nursing increased neural activity in the accessory olfactory bulb and the posteroventral medial amygdala (MeApv), a key node of the accessory olfactory system, as well as in subdivisions of the central amygdala, but not in the ventromedial hypothalamus or the bed nucleus of the stria terminalis. Finally, lesions of the MeApv prevented the loss of male preference during nursing, indicating that the MeApv is required for suppression of male preference during this stage.

Approach and avoidance behavior towards sensory stimuli serve as powerful behavioral readouts of our mental representations of the external world and our expectations and motivations in navigating it. In the olfactory system, approach or avoidance of odors statistically associated with people, places, and things relate to ecologically critical functions like feeding, fear, and reproduction. However, experimental methods for quantifying approach/avoidance behavior in relative terms across odors have been limited. Here we present a novel method for quantifying mouse approach/avoidance in an open field arena scented with up to four odors simultaneously. In lieu of traditional inferential statistics (which greatly limit the information that can be learned in this multivariate experiment), we demonstrate the a priori definition of quantitative hypotheses for the distribution of time among scented corners and the use of information theory-derived statistical metrics to quantify the relative likelihood of each competing hypothesis given the data collected. Finally, we use data from a fear conditioning experiment to demonstrate the application of this method to conclude that fear conditioned mice exhibit a fear generalization gradient that decreases as odorants become more different from the threat-predictive odorant, as opposed to competing hypotheses that mice are specifically avoiding the threat-predictive odorant or have overgeneralized their fear and avoid all test odors regardless of similarity. Critically, this method takes only a few minutes per animal with no prior behavioral training required, and it can be performed easily without automated apparatus.

BackgroundAtopic diseases are estimated to affect 30-40% of the global population. However, the potential protective effect of hypoallergenic infant formula against conditions such as atopic dermatitis (AD), cows milk protein allergy (CMPA), and asthma remains uncertain. ObjectiveTo conduct a systematic review and meta-analysis of randomized controlled trials (RCTs) evaluating hypoallergenic formula for atopic disease prevention in high-risk infants. The primary outcome was AD and secondary outcomes were CMPA and asthma. MethodsA systematic review and meta-analysis was conducted according to PRISMA 2020. RCTs involving high-risk infants were identified through PubMed, Cochrane Library, and Web of Science. Exclusion criteria included interventions not initiated at birth, enrolment of sick infants, and non-RCTs. Pooled Relative Risks (RR) with 95% confidence intervals (CI) were calculated using a random-effects model. ResultsWe included 9 RCTs that enrolled high-risk infants. The meta-analysis found a borderline significant protective effects of AD (RR=0.78 [0.59-1.03], p=0.059; I2=46.5%), a significant protective effect of hypoallergenic formula in prevention of CMPA (RR=0.51 [0.27-0.97], p=0.0228; I2=37.3%), and no significant risk reduction for asthma (RR=0.78 [0.51-1.20], p=0.059; I2=37.5%). ConclusionThis systematic review and meta-analysis found no statistically significant protective effect of hypoallergenic formula for AD or asthma, though a non-significant trend toward risk reduction was observed. A significant risk reduction was seen for CMPA (RR{approx}0.5), although not all diagnoses were confirmed by oral food challenge. These findings suggest potential patient-specific benefits, but larger, well-designed RCTs are needed to confirm them.

Astyanax mexicanus consists of eyed, river-dwelling "surface" fish, and multiple, independently evolved cave populations, which have converged on troglobitic traits such as eye loss and reduced metabolism. However, considerably less is known about constructive adaptations, which include a larger olfactory epithelium in cavefish. It is unknown how this relates to the olfactory bulb (OB), which is the first stage of olfactory sensory processing in the brain. The goal of the present study is to begin to define the structure and functional organization of the OB in A. mexicanus, and to begin to understand how it was transformed via cave adaptation. We addressed these questions using whole-mount immunohistochemistry and in vivo Ca2+ imaging from the OB of developmentally matched surface and Pachon cavefish. The cavefish OB was significantly larger than surface fish by 14 days post fertilization (dpf), which was accompanied by a broad and proportional increase in synaptic input to most glomerular regions. Increases in the size of the OB were accompanied by increases in the number of neurons expressing tyrosine hydroxylase and calretinin, the latter of which occurred primarily in the medial OB and could not be explained as a compensatory response to a larger OB. In vivo Ca2+ imaging from the dorsal OB of surface and cavefish in response to a panel of chemical stimuli revealed odor-evoked responses that were spatially organized and highly conserved across the two populations. Surprisingly, the medial OB was consistently activated by any change in water flow in both populations, although the number of water-responsive neurons was significantly greater in cavefish when measurements were performed using either in vivo imaging or the neuronal activity marker phospho-ERK. Water-responding neurons were similarly present in the olfactory epithelium in both populations, along with neurons expressing the mechanosensitive ion channel Piezo2, with significantly more Piezo2-expressing neurons present in cavefish. Therefore, cavefish exhibit enhanced multisensory integration of olfactory and mechanosensory input in the earliest stage of olfactory sensory processing in the brain.

There is a dearth of information on how different cocktails sweetened with different sugars impact brain activity. Glucose enters the brain faster and in greater concentration than fructose and directly affects neuronal activity of melanin-concentrating hormone (MCH) neurons. MCH signaling promotes both glucose drinking and alcohol intake by integrating central and sensory inputs, but it is currently unknown how MCH neuronal activity relates to sweetened cocktail drinking. This study sought to investigate the relationship between MCH activity and sugar-sweetened alcoholic cocktail drinking. We also sought to compare MCH neuronal responses to the sugar solutions without alcohol as well as their response to sensory stimuli. In female and male rats, we used fiber photometry to monitor MCH neurons in response to sensory stimuli and during drinking of 10% glucose, 10% fructose, and glucose or fructose cocktails with 1.25% or 10% alcohol. We found that MCH activity rises in response to a variety of sensory stimuli and peaks before the start of drinking for all cocktails, before returning to baseline near the start of drinking. The cocktail type impacted the dynamics of MCH activity, where increased alcohol concentration resulted in earlier MCH activity for fructose but not glucose cocktails. Finally, we found that peak MCH activity during drinking is correlated with approach behavior for all sugar and cocktail types. These findings suggest that glucose and alcohol may interact to directly influence MCH activity. Further, MCH neurons may regulate cocktail drinking in response to sugar type and alcohol concentration. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=118 SRC="FIGDIR/small/719280v1_ufig1.gif" ALT="Figure 1"> View larger version (17K): org.highwire.dtl.DTLVardef@b992c3org.highwire.dtl.DTLVardef@1526895org.highwire.dtl.DTLVardef@1504c6dorg.highwire.dtl.DTLVardef@c990fc_HPS_FORMAT_FIGEXP M_FIG C_FIG New and noteworthyFiber photometry was used to monitor lateral hypothalamic melanin-concentrating hormone (MCH) neurons in male and female rats during sensory stimuli and drinking of glucose, fructose, or glucose- or fructose-sweetened alcoholic cocktails. Subsecond-scale changes in MCH activity occurred after stimuli. Peak MCH activity during drinking was correlated with approach behavior. Alcohol concentration only impacted MCH activity with fructose cocktails. We discuss the implications of MCH dynamics towards brain function, associative learning, and alcohol use disorder.

Background and ObjectivesRecurrent acute otitis media (rAOM; defined as [&ge;]3 AOM episodes in 6 months or [&ge;]4 episodes in 12 months) affects 10-15% of children in the United States and is a leading cause of healthcare utilization and antibiotic prescriptions. Prospective identification of children at risk of rAOM could help target interventions and identify new risk factors to guide preventive approaches. We therefore sought to develop predictive models to identify children at risk of rAOM using electronic health records (EHR) data. MethodsWe extracted retrospective EHR data for children who were born at Duke University Health System (DUHS) hospitals between January 1, 2014, and June 30, 2022, and who had at least one AOM episode during the study period. We used LASSO to build predictive models for development of rAOM at each episode and identified factors associated with rAOM. ResultsWe identified 6,566 children who met the study criteria, including 1,634 (24.8%) who met criteria for rAOM. A model using only data available at the first AOM episode had an area under the curve (AUC) of 0.75 (0.73, 0.77) and an Area Under the Precision Recall Curve (AUPRC) of 0.41 (95% CI 0.37, 0.46), indicating moderate discriminative ability. At the time of the first AOM episode, features associated with subsequent rAOM development included age, number of prior antibiotic prescriptions, and diagnosis of gastroesophageal reflux disease (GERD). Further, children who developed rAOM were more likely to experience treatment failure than children who did not meet rAOM criteria across all episodes. ConclusionsOur findings indicate that clinical exposures and patient characteristics documented in the EHR distinguish children who are at risk of developing rAOM. Such models could be deployed within EHR systems to identify children who would benefit from early evaluation by an otolaryngologist and audiologist.

Quantifying feeding behavior with high temporal and spatial precision is critical for understanding how internal state, sensory cues, and neural activity shape food intake and dietary choice. Here, we describe a detailed protocol for performing consumption and dietary choice assays in Drosophila using the flyPAD/optoPAD system. This method enables simultaneous measurement of feeding events across multiple arenas while allowing precise control of gustatory stimuli and optogenetic stimulation. We provide step-by-step instructions for assay food preparation, flyPAD arena setup, data acquisition, and downstream data organization with suggested analyses. This approach is suitable for studying consumption, nutrient preference, learning, and state-dependent modulation of feeding behaviors, and can be readily adapted for optogenetic manipulations and comparative choice assays.

The rat vestibular system plays a critical role in anti-gravity responses such as the tail-lift reflex and the air-righting reflex. In a previous study in male rats, we obtained evidence that these two reflexes depend on the function of non-identical populations of vestibular sensory hair cells (HC). Here, we caused graded lesions in the vestibular system of female rats by exposing the animals to several different doses of an ototoxic chemical, 3,3-iminodipropionitrile (IDPN). After exposure, we assessed the anti-gravity responses of the rats and then assessed the loss of type I HC (HCI) and type II HC (HCII) in the central and peripheral regions of the crista, utricle and saccule. As expected, we recorded a dose-dependent loss of vestibular function and loss of HCs. The relationship between hair cell loss and functional loss was examined using non-linear models fitted by orthogonal distance regression. The results indicated that both the tail-lift reflex and the air-righting reflexes mostly depend on HCI function. However, a different dependency was found on the epithelium triggering the reflex: while the tail-lift response is sensitive to loss of crista and/or utricle HCIs, the air-righting response rather depends on utricular and/or saccular integrity.

Humans are not equally attractive to mosquitoes, leaving some more vulnerable to mosquito-borne illnesses than others. Body odor differences likely allow mosquitoes to discriminate between humans. Using a uniport olfactometer, we measured the attraction of Aedes aegypti, Aedes albopictus, and Culex quinquefasciatus mosquitoes for each of our 119 participants. Ae. aegypti, but not other species tested, were more attracted to male than female participants. Each of our three species ranked our participants differently, favoring a distinct subset of our cohort. For each species, mosquito attraction rates were used to define high and low attraction human odors and bacterial taxa. For example, Ae. aegypti and Cx. quinquefasciatus attraction was associated with the absence of odors like cyclic alcohols and monoterpenes, while Ae. albopictus attraction was associated with the presence of ketones. Each mosquito species exhibited distinct responses to individual humans, emphasizing both unique and shared cues for targeting their hosts.

Equine asthma (EA) is a highly prevalent, chronic, inflammatory disease of the lower airways ranging from mild-to-moderate to severe clinical presentations. Diagnosis currently relies on bronchoalveolar lavage fluid (BALF) cytology, an invasive method associated with interobserver variability, which highlights the need for more reproducible approaches. MicroRNAs (miRNAs) are small noncoding RNAs involved in post-transcriptional gene regulation. They are stable and readily detectable in body fluids and have shown promising results as biomarkers in human asthma. The aim of this study was to characterize miRNA abundance profiles in BALF and serum from horses with distinct EA endotypes to evaluate their biomarker potential and explore their involvement in disease pathogenesis. A total of 43 horses were included and classified as either EA (n=32) or controls (n=11), based on clinical examination and BALF cytology. The EA horses were further divided into three endotypes based on BALF inflammatory cell composition: neutrophilic asthma (n=10), mastocytic asthma (n=15), and mixed asthma (n=7). RNA was isolated from both serum and BALF samples and analyzed by quantitative real-time PCR (qPCR) targeting 103 miRNAs linked to asthma and pulmonary inflammation in humans. Differential miRNA abundance was analyzed across EA endotypes. The most significantly differentially abundant miRNAs were used for in silico target prediction and pathway enrichment analyses. Horses with mixed EA had significantly lower levels of eca-miR-125a-3p and eca-miR-125b-5p in BALF compared to controls. Additionally, eca-miR-146a-5p abundance was significantly increased in BALF from horses with neutrophilic EA compared to mastocytic EA. Target and pathway enrichment analyses for eca-miR-146a-5p identified immune-relevant pathways, such as MAPK and T-cell receptor signaling, supporting its involvement in inflammatory processes associated with asthma. This study identified three promising candidates, eca-miR-125a-3p, eca-miR-125b-5p, and eca-miR-146a-5p, as potential biomarkers associated with different EA endotypes. These miRNAs are interesting candidates for further investigation in an independent cohort.

Objectives: Patients with Cystic fibrosis (CF) often receive aminoglycosides (AGs) to manage recurrent pulmonary infections, placing them at risk for ototoxicity. Chronic AG use can lead to complex cochlear damage affecting inner and outer hair cells, the stria vascularis, and spiral ganglion neurons. The greatest damage is typically in the basal cochlear region, which encodes high-frequency hearing, with additional involvement of more apical regions. While extended-high-frequency (EHF) hearing loss (EHFHL; 9-16 kHz) is often the earliest sign of AG ototoxicity, speech in noise (SiN) effects are rarely studied. Our overall hypothesis is that SiN perception difficulties in individuals with CF, treated with AGs, are related to combined cochlear and neural damage, primarily in the EHF range but also in the standard frequency (SF; 0.25-8 kHz) range. Three mechanisms that contribute to SiN perception were evaluated in children and young adults: 1) a primary effect of reduced EHF sensitivity, measured by pure-tone audiometry (PTA) and transient-evoked otoacoustic emissions (TEOAEs); 2) a secondary effect of subclinical damage in the SF range, measured by PTA and TEOAEs; and 3) additional neural effects, measured by middle ear muscle reflex (MEMR) threshold (afferent) and growth functions (efferent).Design:A total of 185 participants were enrolled; 101 individuals with CF treated with intravenous AGs and 84 age and sex-matched Controls without hearing concerns or CF. Assessments included EHF and SF PTA; the Bamford-Kowal-Bench (BKB)-SIN test for SiN perception; double-evoked TEOAEs with chirp stimuli from 0.71 to 14.7 kHz; and ipsilateral and contralateral wideband MEMR thresholds and growth functions using broadband stimuli. Results: Reduced sensitivity at EHFs (PTA, TEOAEs) was not associated with impaired SiN perception in the CF group. SF hearing, regardless of EHF status, was the primary predictor of SiN performance in the CF group. Increased MEMR growth was also significantly associated with poorer SiN in the CF group. Conclusions: In CF, impaired SiN perception was primarily predicted by SF hearing impairment, with additional involvement of the efferent auditory pathway through increased MEMR growth. These results build on prior evidence for efferent neural effects due to ototoxic exposures, supporting both sensory (afferent) and neural (efferent) mechanisms that contribute to listening difficulties in CF. Thus, preventive and intervention strategies should consider these combined mechanisms in people with AG ototoxicity to address their SiN problems.

Ethyl-iophenoxic acid (Et-IPA) is widely recognized as a useful biomarker to confirm oral bait consumption in eutherian species. In historical studies on marsupials, Et-IPA was rapidly eliminated from brushtail possums (Trichosurus vulpecula) and swamp wallabies (Wallabia bicolor) suggesting limited use for marsupial species. However, a 1 mg oral dose of Et-IPA was detectable in the marsupial Tasmanian devils (Sarcophilus harrisii) for [&ge;] 56 days suggesting the biomarker can be used in a devil bait vaccine program. To assess Et-IPA marking in off-target marsupials that may consume baits, we administered 1 mg oral doses of Et-IPA to brushtail possums, forester kangaroos (Macropus giganteus tasmaniensis), spotted-tailed quolls (Dasyurus maculatus) and eastern quolls (Dasyurus viverrinus). Liquid chromatography with tandem mass spectrometry was used to detect and quantify serum Et-IPA. Et-IPA was detected in the serum on day 2 but was not detected by day 14 in any of the species tested, including the two quoll species which are in the same carnivorous Dasyuridae family as the devils. The rapid elimination of Et-IPA in the marsupials included in this study suggests it is not useful as a biomarker for these species. Furthermore, rapid elimination in the kangaroos and possums suggests that Et-IPA is unlikely to accumulate in the food chain following distribution of Et-IPA-marked oral bait vaccines for Tasmanian devils. Short summary for non-expertsA recent study in Tasmanian devils (Sarcophilus harrisii) challenged the concept that ethyl iophenoxic acid (Et-IPA) is not a useful serum biomarker for marsupials. Using the same sensitive liquid chromatography-tandem mass spectrometry method we detected serum Et-IPA in four marsupial species on day two post-ingestion but by day 14, serum Et-IPA was undetectable. These findings indicate that Et-IPA is an unsuitable biomarker for these species and suggest that Et-IPA from devil bait vaccines is unlikely to bioaccumulate in the Tasmanian environment.

Olfactory sensory neurons (OSNs) project a single axon from the olfactory epithelium to the olfactory bulb. OSNs initially target large, distinct, individually identifiable neuropils called protoglomeruli in the zebrafish embryo. Here we examine the contributions Robo axonal guidance receptors make to OSN axon targeting of protoglomeruli. We show that OSNs that project to the DZ protoglomerulus express higher levels of robo2 than those that project to the CZ protoglomerulus, and concordant with this observation, DZ-projecting axons are more often misrouted by loss of robo2 than are CZ-projecting axons. Further, we demonstrate that in the absence of robo2, robo1 contributes to DZ-targeting but not to CZ-targeting. The loss of either robo1 or robo3 by themselves do not affect targeting to either the CZ or DZ protoglomeruli. These findings identify OSN subtype-dependent contributions of Robo receptors to vertebrate olfactory circuit assembly. In the absence of repellent Slit/Robo signaling, we propose that Netrin1b steers OSN axons to ectopic ventral midline locations where Slit1a and Netrin1b are both expressed.

BackgroundIdentifying metabolites associated with prostate cancer (PC) aggressiveness may elucidate mechanisms underlying disease severity. Doing so for plasma and formalin-fixed, paraffin-embedded (FFPE) tissue could accelerate discovery. In this cross-sectional pilot study, we generated hypotheses for further exploration by assessing associations between plasma metabolites and Gleason score in individuals with PC and evaluating correlations between plasma and FFPE metabolite levels. MethodsWe examined plasma and FFPE samples from 10 individuals with Gleason score 7 (six 3+4, four 4+3) and nine individuals with Gleason score 9 (six 4+5, three 5+4) tumors from a convenience sample of 19 men with PC. We measured the relative abundance of polar metabolites at the time of radical prostatectomy. We used linear models of log2 fold changes to examine plasma metabolite levels relative to pathologic tumor grade. Relationships among metabolite levels measured in plasma and FFPE tumor tissue within individuals across metabolites were examined using Pearson correlations. ResultsAmong 18 plasma metabolites selected a priori because of prior associations with PC aggressiveness, serine (p=0.0051) and ornithine (p=0.036) levels were higher in individuals with Gleason 9 than Gleason 7 PC. After multiple testing correction, however, no associations were statistically significant. The median correlation between levels in plasma and FFPE tumor tissue was 0.45 (range: 0.40-0.53) for the 94 metabolites measured in both biospecimens. ConclusionsPlasma serine and ornithine demonstrated the largest differences between individuals with Gleason 7 and Gleason 9 PC. Metabolite levels in FFPE prostate tissue samples were moderately correlated with plasma levels. Future studies in larger samples are needed to further explore the hypotheses generated by this study.

Introduction: Auditory brainstem response (ABR) is a standard objective method for estimating hearing threshold, especially in patients who cannot reliably participate in behavioral audiometry. However, ABR interpretation is usually performed by an expert. This study evaluated whether two general-purpose artificial intelligence (AI) multimodal large language model (LLM) chatbots, ChatGPT and Qwen, can accurately estimate ABR hearing thresholds from ABR waveform images. The accuracy was measured by comparisons with the judgements of 3 expert audiologists. Methods: A total of 500 images each containing several ABR waveforms recorded at different stimulus intensities were analyzed. Three expert audiologists established the reference auditory thresholds based on visual identification of wave V at the lowest stimulus intensity, with the most frequent judgment among the three used as the reference. Each waveform image was independently submitted to ChatGPT (version 5.1) and Qwen (version 3Max) using the same standardized prompt and without additional clinical context. Agreement with the expert thresholds was assessed as mean errors and correlations. Sensitivity and specificity for detecting hearing loss (>20 dB nHL) were also calculated. In cases where the AI and expert thresholds nominally matched, corresponding latency measures were also compared. Results: Auditory thresholds derived from both LLMs correlated strongly with expert opinion, with Pearson r = 0.954 for ChatGPT and r = 0.958 for Qwen. ChatGPT showed a mean error of +5.5 dB and Qwen showed a mean error of -2.7 dB. Exact nominal agreement with expert values was achieved in 34.6% of ChatGPT estimates and 35.6% of Qwen estimates; agreement within +/-10 dB was observed in 75.6% and 80.0% of cases, respectively. For hearing-loss classification, ChatGPT achieved 100% sensitivity but low specificity (20.4%), whereas Qwen showed a more balanced profile with 91.6% sensitivity and 67.5% specificity. Curiously, estimates of wave V latency were markedly poor for both LLMs, with systematic underestimation and weak correlations with the expert judgements. Conclusion: ChatGPT and Qwen demonstrated a moderate ability to estimate ABR thresholds from waveform images, although their performance was not good enough for independent clinical use. Both models captured general patterns of hearing loss severity, but there was systematic bias, limited specificity and sensitivity balance, and poor latency estimation. General-purpose multimodal LLMs may have potential as assistive or preliminary tools, but clinically reliable ABR interpretation will likely require specialized, domain-trained AI systems with expert oversight.

The management of Hashimotos thyroiditis (HT), one of the most prevalent autoimmune disorders worldwide, becomes more complex when it coexists with type 2 diabetes (T2D) compared with the management of either disease alone. This complexity may arise from overlapping genetic, metabolic, and immune dysregulation, as well as potential therapeutic conflicts. Although HT and T2D are known to co-occur and share immune and metabolic features, the molecular characteristics underlying these overlaps have not been systematically explored. This study aimed to identify shared gene expression signatures and associated biological pathways between HT and T2D using an in silico, hypothesis-generating approach, and to explore candidate compounds that may be relevant to both conditions. Independent transcriptomic datasets (GSE138198 for control/HT and GSE29231 for control/T2D) were analyzed, leading to the identification of 59 genes that were differentially expressed in both HT and T2D compared with control samples. Protein-protein interaction (PPI) network analysis prioritized five shared key genes (sKGs): CDC42, CD74, FOS, RAC2, and YWHAB. Functional enrichment analysis of these sKGs revealed overlapping biological processes, molecular functions, cellular components, and immune-related signaling pathways, as well as shared regulatory networks involving transcription factors (FOXC1 and HNF4A) and microRNAs (hsa-miR-221-3p and hsa-miR-29a-3p). Immune infiltration analysis demonstrated broadly similar patterns of immune dysregulation in both diseases, providing additional biological context for the observed shared molecular signatures. Finally, an exploratory in silico drug repurposing pipeline incorporating molecular docking, ADMET profiling, drug-likeness assessment, and molecular dynamics simulations prioritized three candidate compounds: gliquidone, oleanolic acid, and glipizide for further investigation. Overall, this study provides a hypothesis-generating framework highlighting shared molecular features between HT and T2D, which may inform future experimental validation and clinical research. Author SummaryIn this work, we wanted to better understand why Hashimotos thyroiditis, an autoimmune condition that affects the thyroid gland, is often seen in people who also have type 2 diabetes. Treating patients who live with both conditions can be difficult, and we were interested in finding out whether they share common biological causes. To do this, we examined genetic data from individuals with each disease and looked for patterns that appeared in both groups. We discovered several genes that seem to act in similar ways in the two conditions, particularly genes linked to immune system activity and associated pathways. This finding suggests that shared molecular signatures and immune-associated pathways may play a role in the development of both diseases. We also explored how these shared genetic features influence larger biological processes and immune responses. The similarities we found support the idea that the two diseases may be connected through related biological pathways. In addition, we used computer-based screening methods to identify existing drugs that might influence these shared pathways. While these results need further testing, we hope our findings help open new directions for research and eventually contribute to better care for patients affected by both conditions.