Cold Sensation Research Articles

Cold hypersensitivity in the hands and feet is associated with erectile dysfunction in young Taiwanese men

Cold hypersensitivity in the hands and feet (CHHF) is a protective or predisposing factor for many diseases; however, the relationship between CHHF and erectile dysfunction (ED) remains unclear. We aimed to investigate associations between CHHF and ED among young men of Southeast Asian origin. In this cross-sectional study, sexually active Taiwanese men aged 20–40 years were enrolled via an online questionnaire comprising general demographic information, comorbidities, subjective thermal sensations of their hands and feet in the past 6 months, and their erectile function using the International Index of Erectile Function-5 (IIEF-5). Participants who reported cold sensation of hands and feet were classified to have CHHF; those with IIEF-5 score ≤ 21 were considered to have ED. Total 54.2% and 27.9% of participants had ED and CHHF, respectively. Men with CHHF were significantly younger, had lower body mass index and IIEF-5 scores (p < 0.001), and a lower prevalence of diabetes mellitus (p = 0.033) along with higher prevalence of ED, psychiatric disorders, and insomnia (p < 0.001). After adjusting for predisposing factors of ED, CHHF (odds ratio 1.410, 95% confidence interval 1.159–1.714; p = 0.001) remained an independent predictor of ED. Thus, CHHF is independently associated with ED, affecting more than a quarter of young Taiwanese men. Autonomic dysregulation and subclinical endothelial dysfunction may be common pathophysiologies of CHHF and ED.

Abstract PO4-11-06: Survey of Questionnaires on the Efficacy and Cost of Scalp Cooling Devices in Breast Cancer Patients

Abstract &amp;lt; Background &amp;gt; Scalp cooling devices have demonstrated effectiveness in mitigating chemotherapy-induced alopecia, with an approximate reported success rate of 50% in hair preservation. Nevertheless, their utilization may lead to adverse effects and financial burdens for patients. Our institution introduced the Paxman scalp cooling system in 2021 for breast cancer patients undergoing perioperative chemotherapy, with its application extending to over 120 cases. An out-of-pocket expense of 16,000 yen ($110) per chemotherapy session is required, separate from insurance-covered treatments. We conducted a retrospective evaluation using patient questionnaires and medical records to assess the efficacy and cost-related satisfaction concerning scalp cooling devices. &amp;lt; Methods &amp;gt; The subjects consisted of breast cancer patients who had undergone at least one session of chemotherapy with scalp cooling devices at our institution. Objective assessment of hair preservation was performed through head photographs taken during the usage of the cooling devices and recorded in the medical charts. The evaluation was carried out using CTCAE version 4, and statistical analysis of relationships was conducted utilizing Stata version 18 and the χ² test. &amp;lt; Results &amp;gt; Responses were collected from 91 patients (survey response rate: 96%). The median age of the patients was 51 years (range: 28-80). The regimens of chemotherapy included anthracycline-based (A) in 10 patients (11%), taxane-based (T) in 19 patients (21%), A-T combination in 57 patients (63%), and HER2-targeted therapy in 38 patients (42%). The results of questionnaire revealed, besides scalp cooling, patients incurred a median cost of 131,000 yen($922) for wigs and 10,000 yen($70) for hair care and other expenses. 61 individuals (67%) completed the scalp cooling treatment during the chemotherapy. The reasons for discontinuation of scalp cooling were mainly discomfort due to tightness (33%), followed by the time-consuming nature of the process (30%), hair loss (26%), and excessive cold sensation (26%) (Multiple answers allowed). Regarding the benefits and drawbacks of scalp cooling devices, 50 patients (56%) expressed satisfaction for scalp cooling, 26 patients (29%) had neutral feelings, 14 patients (16%) expressed unsatisfied, and one response was unknown. Regarding the device's cost, 14 patients (16%) were satisfied, 35 patients (40%) were neutral, 39 patients (44%) were unsatisfied, and three responses was unknown. Among the 52 patients who continued using the device until their final chemotherapy session and could assess the head photographs, the hair loss grades were as follows: grade 0 in 9 patients (17%), grade 1 in 22 patients (42%), and grade 2 in 21 patients (40%). A correlation was observed between the objective hair loss grade and satisfaction with the device's efficacy (p &amp;lt; 0.01), while no significant correlation was found between satisfaction and the cost (p = 0.21) (attached table). &amp;lt; Discussion &amp;gt; Although more than half of the patients who utilized scalp cooling devices expressed satisfaction with their efficacy, merely 16% expressed satisfaction with the associated costs. Addressing patient financial burdens, including expand to insurance coverage, becomes imperative for future considerations. Table. The relation between hair preservation and satisfaction for efficacy and cost. A correlation was observed between the objective hair loss grade and satisfaction with the device's efficacy (p &amp;lt; 0.01), while no significant correlation was found between satisfaction and the cost (p = 0.21) Citation Format: Haruru Kotani, Nari Kureyama, Maho Kusudo, Rie Komaki, Akira Nakakami, Yuka Endo, Ayumi Kataoka, Akiyo Yoshimura, Masaya Hattori, Masataka Sawaki, Hiroji Iwata. Survey of Questionnaires on the Efficacy and Cost of Scalp Cooling Devices in Breast Cancer Patients [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 PO4-11-06.

Effects of radiant asymmetry on the thermal comfort conditions: Experiments in a test room

Occupants' well-being in buildings is related to the thermal comfort conditions in indoor spaces. Radiant asymmetry is a parameter of localised discomfort and its evaluation is rather challenging. It should be considered when dealing with radiant systems since they could produce unacceptable asymmetric temperature fields. In this paper, the issue of radiant asymmetry in winter is experimentally investigated in a test room equipped with radiant panels. A first round of testing is carried out to study the limits in terms of supply water temperature of the heated surface in relation to the discomfort curves proposed in the current standards. Configurations with a heated wall or ceiling and the contemporary presence of one or more heat-dissipating surfaces are considered. Twelve scenarios representing real building situations are analysed, each involving three consecutive heating phases with increasing supply temperatures of 30, 35 and 40 °C. The most critical configuration is imposed in a second testing round with 8 participants checking the actual subjects' perceptions through questionnaires, with conditions of global thermal neutrality (PMV = 0). The scenario with a heated ceiling and heat-dissipating floor is the most adverse, generating a vertical asymmetry exceeding the standard limit of 4 °C when the supply temperature is above 35 °C. The survey campaign shows that uncomfortable cold sensations are prevalent with lower radiant asymmetry levels, whereas the highest ceiling temperature improves comfort perception. The results suggest that participants could not feel the asymmetry increment and analysis of radiant asymmetry discomfort should also consider surface temperatures along with plane radiant temperature difference.

Outdoor thermal comfort in open transitional spaces with limited greenery in hot summer/cold winter climates

Regarding the constant use of transitional spaces, there is an intense interest in studies on the outdoor thermal comfort in transitional spaces, especially in regions with hot summers. This study aims to analyze the outdoor thermal comfort conditions of a transitional space focusing on vegetation cover change to distill findings into a set of design guidelines for landscape architects and urban planners to enhance the thermal comfort in open transitional spaces, especially in airport terminals with hot summer, and cold winter climate. The case study for this research is an open transitional area at the Mehr-Abad airport. Mehr-Abad airport experiences blistering summers and freezing winters. The environmental situation is analyzed using ENVI-met software. Subsequently, without-grass and without-tree scenarios were simulated to study the impact of greenery on transitional thermal comfort. The results were validated using the on-site collected data. In this study, results demonstrate that the average PET in the current situation is 39.81 ℃ in summer (hot sensation) and 5 ℃ in winter (cold sensation). Based on the results, removing the grass cover is the most suitable scenario for both summer with 35.80 ℃, and winter with 6.68 ℃. The best scenario consists of adding more deciduous trees to open transitional spaces to reduce solar shading in winter. This study provided a better understanding of the effects of vegetation in transient-oriented limited spaces on outdoor thermal comfort and looked deeper into vegetation characteristics concerning the transitional space requirements in hot summer/cold winter climates.

Use of Coolsticks in district general hospital

Introduction: Ethyl chloride spray is conventionally used for testing cold sensation during spinal or epidural blocks.Coolsticks are reusable, durable, non-toxic stainless steels wants that can be cooled and are a cheaper alternative to ethyl chloride spray. The aim of this studd was to estimate the cost and carbon savings of switching from ethyl chloride spray to Coolstick use. Methods: The use of Coolsticks at a single district general hospital’s (Good Hope Hospital, Sutton Coldfield, UK) main theatres was audited in July 2023. The volume of ethyl chloride use in the obstetric theatre in 2022-23 was calculated based on pharmacy requisition forms. Estimates of CO2 equivalent emissions per stick and per ethyl chloride spray use were based on published data (Green Ward study from Dorset). Cost and CO2 equivalent emissions savings with cold sticks were calculated and extrapolated onto all seven theatres within Good Hope Hospital. Results: Only 25% of anaesthetists used Coolsticks, despite all being aware of their availability. The main reason stated for this was “adherence to usual practice”. In the obstetric theatre in 2022-23, 104 cans of ethyl chloride were used. Switching to Coolstick use would save £2,080 and 1,693kg CO2 equivalent per theatre per year. Extrapolating across the hospital, the potential saving was £14,560 and 11,852 kg CO2 equivalent per year. Conclusion: Use of Coolsticks is cost-saving and carbon-efficient. National associations should consider publishing formal recommendations to support their uptake. Research around clinical efficacy and patient satisfaction would speed uptake into clinical practice.

Association of Cold/Heat Sensation with Sleep Quality and Insomnia in Middle-aged Women

Objectives: Cold extremities have been suggested to correlate with sleep disturbances. This study aims to explore the relationship between thermal sensations in body, encompassing both cold and heat sensations, with sleep quality and insomnia.Methods: Self-administered questionnaires were utilized to assess thermal sensations in body, sleep quality and symptoms of insomnia in middle-aged women. A multiple logistic regression analysis was performed to ascertain the association between thermal sensations in body and both sleep quality and insomnia symptoms.Results: Among 899 participants, 255 (28.4%) were categorized in the cold sensation group, 95 (10.6%) in the heat sensation group, 70 (7.8%) in the group with both cold and heat sensations, and 479 (53.3%) in the no-sensation group. Pittsburgh Sleep Quality Index and Insomnia Severity Index were notably higher in the group experiencing both sensations when compared to the no-sensation group. After adjustments for covariates, the odds ratios for poor sleep quality, moderate/severe insomnia, and long sleep latency were significantly elevated in the group with both sensations when compared to the no-sensation group. The odds ratios for poor sleep quality in the cold sensation group and for moderate/severe insomnia and low sleep efficiency in the heat sensation group were significantly higher when compared to the no-sensation group.Conclusions: The risk for sleep disturbances varied depending on the presence of thermal sensations in body, with the greatest risk observed for low sleep quality and insomnia in individuals experiencing both cold and heat sensations.

Gender disparities in thermal responses under vertical air temperature differences

The effects of vertical temperature differences (VTD) on human thermal comfort have attracted growing attention from researchers when utilizing split air conditioners for winter heating. This study underscores the need to investigate the influences of gender disparities in the context of significant vertical temperature variations, a critical aspect that has not yet been comprehensively explored. Twenty gender-balanced subjects were exposed to a variety of stratified thermal environments created by a split air-conditioner. Their overall and local perceptual and physiological responses were measured at various operative temperatures and VTD. Results show that females have lower thermal sensation vote (TSV) and mean skin temperature under the same environments compared to males. Neutral operative temperatures of females and males are 23.7 ˚C and 20.8 ˚C, respectively. On the cold side, lower leg and foot thermal sensations are dominant whereas chest and back are dominant on the warm side. When females rated “slightly warm” (TSV equaled 1) or “warm” (TSV equaled 2), or males rated “slightly cool” (TSV equaled −1), increased VTD can lower thermal acceptability. The research findings have significant implications for the understanding of gender requirements of stratified heating environments and for maximizing the thermal comfort of the two genders.

Prophylactic infusion of norepinephrine does not affect the rostral spread of spinal anesthesia in pregnancy: a prospective, randomized, double-blinded study.

Background: The infusion of phenylephrine to prevent spinal-induced hypotension (SIH) in cesarean delivery may decrease the rostral spread of a spinal local anesthetic. We hypothesized that infusion of norepinephrine may decrease the rostral spread of spinal anesthesia, similar to that caused by phenylephrine. The aim of this study was to compare the block height of spinal anesthesia in the presence or absence of norepinephrine infusion administered to prevent SIH during cesarean delivery. Methods: Eighty patients were enrolled and allocated into groups receiving a norepinephrine infusion (group N) or saline infusion (group C). After intrathecal injection of hyperbaric bupivacaine 10mg, the block height for cold and pinprick sensation was checked 10 and 20min after the injection. The demographic characteristics, spinal anesthesia, side effects, and neonatal outcomes were also recorded. Results: The block height for cold and pinprick sensation was similar between the two groups, although the incidence of hypotension was significantly lower (p < 0.00) in group N than in group C. Systolic blood pressure was also more stable in group N than in group C, with the incidence of interventions being significantly lower in group N. There was no significant difference in patient satisfaction between the two groups. Conclusion: Evidence from this study suggested that prophylactic norepinephrine infusion does not reduce the rostral spread of spinal anesthesia in pregnancy. We suggest that it is not necessary to increase the dose of an intrathecal local anesthetic for cesarean delivery when prophylactic norepinephrine is administered. Clinical Trial Registration: https://www.chictr.org.cn/bin/project/edit?pid=152899, identifier [ChiCTR2200057439].

The impact of temperature and a chemesthetic cooling agent on lingual roughness sensitivity.

Oral tactile sensitivity underpins food texture perception, but few studies have investigated mechanoreception in oral tissues. During food consumption, oral tissues are exposed to a wide range of temperatures and chemical entities. The objective of the present study was to assess the influence of thermal sensations on lingual roughness sensitivity. Just-noticeable difference thresholds (JNDs) were determined using the staircase method for surface roughness from stainless steel coupons (Ra; 0.177-0.465 µm). Thresholds were assessed when cooling or heating the metal stimuli (n = 32 subjects). Compared to the JND threshold obtained at an ambient stimulus temperature (21 °C: 0.055 ± 0.010 μm), a cold (8 °C) temperature significantly (P = 0.019) reduced tongue sensitivity (i.e. increased JND) to surface roughness (0.109 ± 0.016 μm, respectively) whereas warm and hot temperatures had no significant effect (35 °C: 0.084 ± 0.012 μm; 45 °C: 0.081 ± 0.011 μm). To assess whether the effect of cooling on roughness thresholds is TRPM8-dependent, we collected roughness thresholds in a second cohort of subjects (n = 27) following the lingual application of the cooling compound Evercool 190 (24.3 µM). Interestingly, when Evercool 190 was used to elicit the cold sensation, lingual roughness JNDs were unaffected compared to the control application of water (EC: 0.112 ± 0.016 μm; water: 0.102 ± 0.017 μm; P = 0.604). That lingual roughness sensitivity is decreased by cold temperature, but not chemicals evoking cold sensations, suggests the mechanism underpinning thermal modulation is not TRPM8 dependent.

Revisiting a classical theory of sensory specificity: assessing consistency and stability of thermosensitive spots.

Thermal sensitivity is not uniform across the skin, and is particularly high in small (∼1 mm2) regions termed "thermosensitive spots." These spots are thought to reflect the anatomical location of specialized thermosensitive nerve endings from single primary afferents. Thermosensitive spots provide foundational support for "labeled line" or specificity theory of sensory perception, which states that different sensory qualities are transmitted by separate and specific neural pathways. This theory predicts a highly stable relation between repetitions of a thermal stimulus and the resulting sensory quality, yet these predictions have rarely been tested systematically. Here, we present the qualitative, spatial, and repeatability properties of 334 thermosensitive spots on the dorsal forearm sampled across four separate sessions. In line with previous literature, we found that spots associated with cold sensations (112 cold spots, 34%) were more frequent than spots associated with warm sensations (41 warm spots, 12%). Still more frequent (165 spots, 49%) were spots that elicited inconsistent sensations when repeatedly stimulated by the same temperature. Remarkably, only 13 spots (4%) conserved their position between sessions. Overall, we show unexpected inconsistency of both the perceptual responses elicited by spot stimulation and of spot locations across time. These observations suggest reappraisals of the traditional view that thermosensitive spots reflect the location of individual thermosensitive, unimodal primary afferents serving as specific labeled lines for corresponding sensory qualities.NEW & NOTEWORTHY Thermosensitive spots are clustered rather than randomly distributed and have the highest density near the wrist. Surprisingly, we found that thermosensitive spots elicit inconsistent sensory qualities and are unstable over time. Our results question the widely believed notion that thermosensitive spots reflect the location of individual thermoreceptive, unimodal primary afferents that serve as labelled lines for corresponding sensory qualities.

Treatment of Complete Brachial Plexus Injuries Using Double Free Muscle Transfer

The purpose of this study was to examine the surgical outcomes of double free muscle transfer (DFMT) performed in patients with complete brachial plexus injury (BPI). We retrospectively analyzed the outcomes of DFMT for 12 patients with complete BPI who were followed up for more than 2 years after the final muscle transplantation. Their mean age was 29 years (range, 18-41). Three patients underwent contralateral C7 nerve root transfer before the DFMT. The range of motion (ROM) of the shoulder, elbow, and fingers was measured. Patient-reported outcome measures, including Disability of the Shoulder, Arm, and Hand (DASH) scores and visual analog scale (VAS) scores for pain, were also examined. The mean shoulder ROM against gravity was 22° ± 8° in abduction and 33° ± 5° in flexion. Seven patients underwent phrenic nerve (PhN) transfer to the suprascapular nerves, and five exhibited asymptomatic lung impairment on spirography more than 2 years after PhN transfer. The mean elbow ROM against gravity was 111° ± 9° in flexion and -32° ± 7° in extension. All patients obtained elbow flexion >90° against a 0.5-kg weight. All patients obtained touch sensation and two recognized warm and cold sensations in the affected palm. The mean total active motion of the affected fingers was 44° ± 11°. All patients exhibited hook function of the hands. The mean preoperative and postoperative DASH scores were 70.3 ± 13.4 and 51.8 ± 15.9, respectively. The mean pain VAS score was 28 ± 31 at the final follow-up. Double free muscle transfer provided patients with complete brachial plexus palsy with good elbow flexion and hand hook functions. Therapeutic IV.

Integration of Independent Heat Transfer Mechanisms for Non-Contact Cold Sensation Presentation With Low Residual Heat.

Thermal sensation is crucial to enhancing our comprehension of the world and enhancing our ability to interact with it. Therefore, the development of thermal sensation presentation technologies holds significant potential, providing a novel method of interaction. Traditional technologies often leave residual heat in the system or the skin, affecting subsequent presentations. Our study focuses on presenting thermal sensations with low residual heat, especially cold sensations. To mitigate the impact of residual heat in the presentation system, we opted for a non-contact method, and to address the influence of residual heat on the skin, we present thermal sensations without significantly altering skin temperature. Specifically, we integrated two highly responsive and independent heat transfer mechanisms: convection via cold air and radiation via visible light, providing non-contact thermal stimuli. By rapidly alternating between perceptible decreases and imperceptible increases in temperature on the same skin area, we maintained near-constant skin temperature while presenting continuous cold sensations. In our experiments involving 15 participants, we observed that when the cooling rate was -0.2 to -0.24 °C/s and the cooling time ratio was 30 to 50%, more than 86.67% of the participants perceived only persistent cold without any warmth.

Surface engineered long-lasting antibacterial Janus cotton fabrics with excellent moisture/thermal management properties

The hydrophilic property of traditional cotton fabrics invariably facilitates sweat absorption, potentially leading to discomfort such as cold and clammy sensation, and even promoting bacterial proliferation. Herein, we developed a Janus cotton fabric using a surface engineering strategy combining “graft through” and “mist polymerization” methodologies. Through the “graft through” polymerization of methacryloyloxyethyl dodecyl dimethyl ammonium bromide (DMDB), we constructed a well-designed antibacterial coating on the fabric with amphiphilic properties. The resulting polymer, PDMDB, imparts highly efficient and durable antibacterial properties to the cotton fabric, achieving a bcteriostatic rates against S. aureus and E. coli of > 99.9 %. Even after undergoing 150 washing cycles, the residual bactericidal efficacy remains above 99 %. Additionally, the reversible hydrophilic-hydrophobic nature of PDMDB successfully enables the construction of a Janus structure on cotton fabrics via “mist polymerization”. Benefiting from its comprehensive design, the Janus cotton fabrics realize a superior directional liquid transport property. Its water evaporation rate is 1.3–1.5 times higher than that of the original cotton fabric in continuous outdoor moisture management, while maintaining body temperature 5.63 °C lower than that of the surrounding environment. It is worth mentioning that our approach utilizes abundant raw materials and facile modification technologies, thereby providing a favorable guarantee for the mass production and use of Janus cotton fabrics.

Cold-Temperature Coding with Bursting and Spiking Based on TRP Channel Dynamics in Drosophila Larva Sensory Neurons.

Temperature sensation involves thermosensitive TRP (thermoTRP) and non-TRP channels. Drosophila larval Class III (CIII) neurons serve as the primary cold nociceptors and express a suite of thermoTRP channels implicated in noxious cold sensation. How CIII neurons code temperature remains unclear. We combined computational and electrophysiological methods to address this question. In electrophysiological experiments, we identified two basic cold-evoked patterns of CIII neurons: bursting and spiking. In response to a fast temperature drop to noxious cold, CIII neurons distinctly mark different phases of the stimulus. Bursts frequently occurred along with the fast temperature drop, forming a peak in the spiking rate and likely coding the high rate of the temperature change. Single spikes dominated at a steady temperature and exhibited frequency adaptation following the peak. When temperature decreased slowly to the same value, mainly spiking activity was observed, with bursts occurring sporadically throughout the stimulation. The spike and the burst frequencies positively correlated with the rate of the temperature drop. Using a computational model, we explain the distinction in the occurrence of the two CIII cold-evoked patterns bursting and spiking using the dynamics of a thermoTRP current. A two-parameter activity map (Temperature, constant TRP current conductance) marks parameters that support silent, spiking, and bursting regimes. Projecting on the map the instantaneous TRP conductance, governed by activation and inactivation processes, reflects temperature coding responses as a path across silent, spiking, or bursting domains on the map. The map sheds light on how various parameter sets for TRP kinetics represent various types of cold-evoked responses. Together, our results indicate that bursting detects the high rate of temperature change, whereas tonic spiking could reflect both the rate of change and magnitude of steady cold temperature.

Strong and aversive cold processing and pain facilitation in fibromyalgia patients relates to augmented thermal grill illusion

The thermal grill illusion (TGI) is assumed to result from crosstalk between the thermoreceptive and nociceptive pathways. To elucidate this further, we compared 40 female fibromyalgia patients to 20 healthy women in an exploratory cross-sectional study. Sensations (cold, warm/heat, unpleasantness, pain and burning) evoked by 20 °C, 40 °C and alternating 20 °C/40 °C (TGI) and somatosensory profiles according to standardized quantitative sensory testing (QST) were assessed on the palm of the dominant hand. Compared to healthy controls, fibromyalgia patients reported stronger thermal grill-evoked cold, warm, unpleasantness and pain as well as stronger and more aversive 20 °C- and 40 °C-evoked sensations. They showed a loss in warm, mechanical and vibration detection, a gain in thermal pain thresholds and higher temporal summation (TS). Among QST parameters higher TS in fibromyalgia patients was most consistently associated with an augmented TGI. Independently, an increased TGI was linked to cold (20 °C) but less to warm (40 °C) perception. In fibromyalgia patients all thermal grill-evoked sensations were positively related to a higher 20 °C-evoked cold sensation and/or 20 °C-evoked unpleasantness. In conclusion, the TGI appears to be driven mainly by the cold-input. Aversive cold processing and central pain facilitation in fibromyalgia patients seem to independently augment the activation of the pain pathway.

A cyclist’s thermal comfort dilemma: Is faster better?

Thermal balance between the body and the environment is a precondition of thermal comfort. This balance depends on the bodily heat generation due to metabolism and heat dissipation to the ambient. Various thermoregulatory mechanisms are in place to adjust the latter in response to changes in the former and maintain the balance. Otherwise, thermal discomfort occurs due to a sensation of warmth or cold, depending on in which direction the balance is tipped. This short paper uses basic thermodynamic models to examine the role of cycling speed in improving thermal comfort. The effect of higher speed on both metabolic heat generation and heat dissipation is examined for various road and environmental conditions to determine whether cycling faster could provide relief from thermal discomfort. The results suggest a net cooling effect, desirable under heat surplus, is unlikely to be achieved. A net heating effect, on the other hand, can be achieved for mildly cold conditions.

Association of higher transient receptor potential melastatin 8 expression with higher tumor histologic grades, lymph node metastasis, risk factors, and worse survival in patients with head and neck squamous cell carcinoma

Background/purposeTransient receptor potential melastatin 8 (TRPM8), a thermosensitive ion channel known for its role in cold sensation and menthol response, has emerged as a potential regulator in various cancers. This study aimed to investigate expression trends of TRPM8 in head and neck squamous cell carcinoma (HNSCC) cases and oral squamous cell carcinoma (OSCC) cell lines and its association with clinicopathological features. Materials and methodsThe noncancerous matched tissues and HNSCC paired tissue samples from 84 HNSCC patients were utilized to evaluate the association of TRPM8 with HNSCC clinicopathological features. TRPM8 expression was examined in HNSCC patient tissues and OSCC cell lines treated with arecoline. ResultsKaplan-Meier survival analysis of TCGA data revealed high TRPM8 expression correlated with unfavorable outcomes and higher tumor histologic grades. TRPM8 mRNA expression was upregulated in HNSCC cell lines and patients’ tissue samples. Arecoline treatment led to significantly increased TRPM8 mRNA and protein expression in OSCC cell lines. Lymph node metastasis showed a significant association with upregulated TRPM8 expression in combined OSCC and oropharyngeal squamous cell carcinoma (OPSCC) cases. TRPM8 mRNA expression was upregulated in HNSCC and OSCC patients with alcohol drinking and cigarette smoking habits, but not in betel quid chewing. ConclusionThese findings reveal the involvement of TRPM8 in HNSCC's malignant development and metastasis, suggesting that high expression of TRMP8 may be mutually causal with addiction to tobacco, alcohol, and betel nut in HNSCC patients. Further investigations are needed to determine the underlying pathways of TRPM8 in HNSCC's development and progression.

Prediction of cell-cell communication patterns of dorsal root ganglion cells: single-cell RNA sequencing data analysis.

Abstract JOURNAL/nrgr/04.03/01300535-202406000-00042/inline-graphic1/v/2023-10-30T152229Z/r/image-tiff Dorsal root ganglion neurons transmit peripheral somatic information to the central nervous system, and dorsal root ganglion neuron excitability affects pain perception. Dorsal root ganglion stimulation is a new approach for managing pain sensation. Knowledge of the cell-cell communication among dorsal root ganglion cells may help in the development of new pain and itch management strategies. Here, we used the single-cell RNA-sequencing (scRNA-seq) database to investigate intercellular communication networks among dorsal root ganglion cells. We collected scRNA-seq data from six samples from three studies, yielding data on a total of 17,766 cells. Based on genetic profiles, we identified satellite glial cells, Schwann cells, neurons, vascular endothelial cells, immune cells, fibroblasts, and vascular smooth muscle cells. Further analysis revealed that eight types of dorsal root ganglion neurons mediated proprioceptive, itch, touch, mechanical, heat, and cold sensations. Moreover, we predicted several distinct forms of intercellular communication among dorsal root ganglion cells, including cell-cell contact, secreted signals, extracellular matrix, and neurotransmitter-mediated signals. The data mining predicted that Mrgpra3-positive neurons robustly express the genes encoding the adenosine Adora2b (A2B) receptor and glial cell line-derived neurotrophic factor family receptor alpha 1 (GFRα-1). Our immunohistochemistry results confirmed the coexpression of the A2B receptor and GFRα-1. Intrathecal injection of the A2B receptor antagonist PSB-603 effectively prevented histamine-induced scratching behaviour in a dose-dependent manner. Our results demonstrate the involvement of the A2B receptor in the modulation of itch sensation. Furthermore, our findings provide insight into dorsal root ganglion cell-cell communication patterns and mechanisms. Our results should contribute to the development of new strategies for the regulation of dorsal root ganglion excitability.

Seasonal analysis of thermal comfort in Mediterranean social courtyards: A comparative study

Neighbourhoods in cities generate social inequality risks due to outdated climate passive control infrastructures. Previous research has explored thermal comfort related to health emergencies in energy-poverty areas. However, there is scant research on the courtyard's thermodynamic performance and its implication on thermal comfort throughout the year. This study evaluates that performance in Seville's social housing courtyards in extreme seasons. Monitoring campaigns were conducted to assess courtyard temperatures linked to outdoor environment. Results show that temperatures within the courtyards were 8.6–12.1 °C lower than the outdoor environment during the warm season and up to 3.3 °C warmer at night during the cold season. Thermal comfort in courtyards could reach comfortable conditions during 92% of the daytime hours in summer, reducing the sensation of extreme cold by more than 6 °C in winter when evaluated using Physiologically Equivalent Temperature. This highlights the ability of courtyards to mitigate health risks linked to extreme temperatures.

Nitrous oxide consistently attenuates thermogenic and thermoperceptual responses to repetitive cold stress in humans.

Divers are at enhanced risk of hypothermia, due to the independent action of the inspired inert gases on thermoregulation. Thus, narcosis induced by acute (≤2 h) exposure to either hyperbaric nitrogen or normobaric nitrous oxide (N2O) impairs shivering thermogenesis and accelerates body core cooling. Animal-based studies, however, have indicated that repeated and sustained N2O administration may prevent N2O-evoked hypometabolism. We, therefore, examined the effects of prolonged intermittent exposure to 30% N2O on human thermoeffector plasticity in response to moderate cold. Fourteen men participated in two ∼12-h sessions, during which they performed sequentially three 120-min cold-water immersions (CWIs) in 20°C water, separated by 120-min rewarming. During CWIs, subjects were breathing either normal air or a normoxic gas mixture containing 30% N2O. Rectal and skin temperatures, metabolic heat production (via indirect calorimetry), finger and forearm cutaneous vascular conductance (CVC; laser-Doppler fluxmetry/mean arterial pressure), and thermal sensation and comfort were monitored. N2O aggravated the drop in rectal temperature (P = 0.01), especially during the first (by ∼0.3°C) and third (by ∼0.4°C) CWIs. N2O invariably blunted the cold-induced elevation of metabolic heat production by ∼22%-25% (P < 0.001). During the initial ∼30 min of the first and second CWIs, N2O attenuated the cold-induced drop in finger (P ≤ 0.001), but not in forearm CVC. N2O alleviated the sensation of coldness and thermal discomfort throughout (P < 0.001). Thus, the present results demonstrate that, regardless of the cumulative duration of gas exposure, a subanesthetic dose of N2O depresses human thermoregulatory functions and precipitates the development of hypothermia.NEW & NOTEWORTHY Human thermoeffector plasticity was evaluated in response to prolonged iterative exposure to 30% N2O and moderate cold stress. Regardless of the duration of gas exposure, N2O-induced narcosis impaired in a persistent manner shivering thermogenesis and thermoperception.