Hand Immersion Research Articles

Regulation of Ventilation and Perceived Effort of Breathing by Locomotor Muscle Metaboreceptor Afferents in Patients with Chronic Obstructive Pulmonary Disease

Exercise intolerance in chronic obstructive pulmonary disease (COPD) is greater for lower limb locomotor exercise as compared to upper limb exercise, presumably due to greater ventilatory constraint and sense of breathing effort (the main component of dyspnea sensation) in the former. Muscle afferent signaling has been proposed to be involved on dysfunctional ventilatory and perceptual responses to exercise in COPD. However, ventilatory responses to muscle metaboreflex activation in locomotor muscles remain uninvestigated. Moreover, regardless of exercise mode, the effect of muscle metaboreflex activation on perceived effort of breathing has never been explored. Therefore, we investigated the effect of locomotor muscle metaboreflex activation on ventilation and perceived effort of breathing in COPD. Nine patients with moderate‐to‐severe COPD and nine age‐ and sex‐matched controls (CON) performed constant work rate cycle ergometry using both lower limbs. Workload was set at 75% of maximal for 4 min. Then subjects recovered at rest for 2 min either with or without unilateral lower limb circulatory occlusion. After a 30‐min interval, subjects were crossed over to the other experimental trial. On another visit, patients were submitted to the cold pressor test (CPT; hand immersion on iced water).The CPT was used to provoke a stress response independently from muscle afferents activation. In contrast to free flow recovery, recovery with circulatory occlusion increased systolic and diastolic arterial pressures, increased pulmonary ventilation, increased respiratory frequency and decreased expiratory time similarly in COPD and CON. Circulatory occlusion did not change tidal volume in both groups. Of note, circulatory occlusion decreased inspiratory time (mean±SD; COPD: occlusion = 0.90±0.27 vs free flow = 1.00±0.20 units; P < 0.01; CON: occlusion = 1.24±0.37 vs free flow = 1.22±0.29 units; P = 0.66) and increased inspiratory flow (COPD: occlusion = 1.09 ± 0.25 vs free flow = 0.90 ± 0.10 L/s; P < 0.01; CON: occlusion = 0.95 ± 0.27 vs free flow = 0.92 ± 0.23 L/s; P = 0.61), a surrogate of the inspiratory drive, only in COPD. On the other hand, circulatory occlusion increased perceived effort of breathing only in CON (COPD: occlusion = 1.4±0.9 vs free flow = 1.1±0.9 units; P = 0.53; CON: occlusion = 4.3±2.3 vs free flow = 1.9±1.1 units; P < 0.001). CPT increased arterial pressure, but did not change pulmonary ventilation, respiratory pattern and perceived effort of breathing in COPD. In conclusion, locomotor muscle metaboreflex activation stimulated pulmonary ventilation and inspiratory drive without affecting perceived effort of breathing in patients with COPD. Such responses were specific to the muscle metaboreflex activation and suggest that the muscle metaboreflex per se is not linked with the origin of COPD exertional dyspnea.Support or Funding InformationThe study was funded by (FAPESP: 2017/07771‐3). L.C.A. and T.O.F received CAPES scholarships. I.C.R received a FAPESP scholarship.

Efektivitas Perendaman Tangan Kaki dengan Air dan Pengolesan Campuran VCO dan Olive Oil dalam Mengatasi Efek Samping Kemoterapi (Palmar-Plantar Erythorodysesthesia) pada Pasien Kanker Kolon di Murni Teguh Memorial Hospital

Patients with colon cancer undergoing chemotherapy at the Pure Teguh Memorial Hospital both inpatient and outpatient experience many Palmar-Plantar Erythrodysesthesia. Palmar-Plantar Erythrodysesthesia incident that occurs in colon cancer patients due to side effects of chemotherapy. The high incidence of Plamr-Plantar Erythrodysesthesia in colon cancer patients is related to the lack of immersion of the feet with water and the application of a misture of VCO and olive oil. This type of research is a quasy experimental study of post test only non eguivalent control group design that aims to determine the effectiveness of soaking the foot with water and applying a mixture of VCO and Olive Oil in overcoming the side effects of chemotherapy (Palmar-Plantar Erythrodysesthesia) in colon cancer patients in Pure Teguh Memorial Hospital.The population in this study were all colon cancer patients who were undergoing chemotherapy in the Murni Teguh Memorial hospital chemotherapy center as many as 90 patients and a sample of 90 patients consisting of 45 people in the intervention group and 45 in the control group). Data were analyzed with chi square test. The results of the study are the effectiveness of foot immersion soaking with water and the application of a mixture of VCO and olive oil to overcome the side effects of chemotherapy (Palmar-Plantar Erythrodysesthesia) in colon cancer patients at Murni Teguh Memorial Hospital.As a suggestion in this study, it is expected that immersion of foot hands with water and the application of a mixture of VCO and olive oil to reduce Palmar-Plantar Erythrodysesthesia in colon cancer patients at Murni Teguh Memorial Hospital and for patients should immerse foot hands with water and basting mixture of VCO olive oil data to reduce the incidence of Palmar-Plantar Erythrodysesthesia.

Effects of Cold Stimulation Induced Pain on Cardiopulmonary Parameters: A Gender Based Study

Background Cold pressor induced pain elicits sympathetic responses which can be monitored by measuring blood pressure, heart rate and respiratory rate after exposure to the cold stress. Objective This study was done to evaluate gender difference in acute pain induced by cold pressor test on blood pressure, heart rate and respiratory rate of healthy individuals. Method Our study was cross sectional study with the sample size of 40 including 20 male and 20 female undergraduates. Acute pain was induced by immersion of hand in cold water at 4o C. Changes in blood pressure, heart rate and respiratory rate were recorded by the digital sphygmomanometer and AD Instruments (Model: ML856, Serial: T26-4025) and analysis was done by Lab Chart 7 Pro v 7.3.3 respectively. Acute pain parameter like pain threshold was also recorded. Statistical analysis was done by using Paired "t" test and non-parametric test. Result The present study enrolled 40 participants, aged between 18 - 24 years, and body mass index from 15.78 - 36.06 kg/m2 . The respiratory rate was increased in both males (17.30±3.19 to 19.0±3.21, P=0.01) and females (18.60±1.98 to 19.90±2.82, P= 0.01) however significant increase in heart rate was only found in females (77.80±8.07 to 80.70±7.80, P=0.03) after cold pressor test. The systolic as well as diastolic blood pressure did not increase significantly after cold pressor test. The pain thresholds ranged from 25.2 to 105.8 seconds (61.60±23.26, male Vs. 52.69±18.49, female, p = 0.188). Conclusion Our findings point towards autonomic adjustments suggesting more of sympathetic over activity immediately after cold pressor test.

Local hyperalgesia, normal endogenous modulation with pain report beyond its origin: a pilot study prompting further exploration into plantar fasciopathy.

Background and aims Persistent tendinopathies were previously considered solely as peripheral conditions affecting the local tendinous tissue until quantitative sensory testing identified involvement of altered pain processing. In similar fashion, pain in patients with persistent plantar fasciopathy may also involve more than local tissue. The aim of this pilot study was to investigate potential differences in conditioned pain modulation and pressure and thermal pain thresholds, between individuals with PF and healthy pain-free controls, as a precursor to a larger-scale study. Methods We assessed 16 individuals with plantar fasciopathy and 11 pain-free controls. Plantar fasciopathy diagnosis was: palpation pain of the medial calcaneal tubercle or the proximal plantar fascia, duration ≥3 months, pain intensity ≥2/10, and ultrasound-measured plantar fascia thickness ≥4 mm. Quantitative sensory tests were performed locally at the plantar heel and remotely on the ipsilateral elbow. Assessments included pain thresholds for pressure, heat and cold, and conditioned pain modulation measured as change in local resting pressure pain threshold with cold water hand immersion. Participants rated pain intensity at pain threshold. Additionally, the area and distribution of plantar fasciopathy pain was drawn on a digital body chart of the lower limbs. Descriptive analyses were performed and between-group differences/effects expressed as standardised mean differences (d). Results There was no conditioned pain modulation difference between participants with plantar fasciopathy and controls (d = 0.1). Largest effects were on local pressure pain threshold and reported pain intensity on pressure pain threshold (d > 1.8) followed by pain intensity for heat and cold pain thresholds (d = 0.3-1.5). According to the digital body chart, pain area extended beyond the plantar heel. Conclusions The unlikelihood of a difference in conditioned pain modulation yet a pain area extending beyond the plantar heel provide a basis for exploring altered pain processing in a larger-scale study. Implications This was the first study to investigate the presence of altered pain processing in individuals with plantar fasciopathy using a conditioned pain modulation paradigm and thermal pain thresholds. We found no indication of an altered pain processing based on these measures, however, patients rated pain higher on thresholds compared to controls which may be important to clinical practice and warrants further exploration in the future.

A Functional Near-Infrared Spectroscopy Study on the Cortical Haemodynamic Responses During the Maastricht Acute Stress Test

In order to better understand stress responses, neuroimaging studies have investigated the underlying neural correlates of stress. Amongst other brain regions, they highlight the involvement of the prefrontal cortex. The aim of the present study was to explore haemodynamic changes in the prefrontal cortex during the Maastricht Acute Stress Test (MAST) using mobile functional Near-Infrared Spectroscopy (fNIRS), examining the stress response in an ecological environment. The MAST includes a challenging mental arithmic task and a physically stressful ice-water task. In a between-subject design, participants either performed the MAST or a non-stress control condition. FNIRS data were recorded throughout the test. Additionally, subjective stress ratings, heart rate and salivary cortisol were evaluated, confirming a successful stress induction. The fNIRS data indicated significantly increased neural activity of brain regions of the dorsolateral prefrontal cortex (dlPFC) and the orbitofrontal cortex (OFC) in response to the MAST, compared to the control condition. Furthermore, the mental arithmetic task indicated an increase in neural activity in brain regions of the dlPFC and OFC; whereas the physically stressful hand immersion task indicated a lateral decrease of neural activity in the left dlPFC. The study highlights the potential use of mobile fNIRS in clinical and applied (stress) research.

Investigating Effects of Cold Water Hand Immersion on Selective Attention in Normobaric Hypoxia.

This study investigated the effect of cold-water hand immersion on selective attention as measured by the Stroop Color Word Test in nomorbaric normoxia and hypoxia. Ten healthy men rested for 60 min, after which they immersed their non-dominant hand into 5 °C water for 15 min. The interference score of the Stroop Color Word Test and thermal sensation were measured at baseline in the final 5 min of resting and in the final 5 min of cold water hand immersion. The interference score was not influenced by hypoxia but was found to be significantly improved compared to resting in both conditions during cold water hand immersion. Selective attention improved during 15 min of cold-water hand immersion, with increased thermal sensations rated as “very cool” of the immersed arm. Cold-water hand immersion may be helpful in improving cognitive function in normoxia and normobaric hypoxia.

Acute effects of salbutamol on systemic vascular function in people with asthma.

Asthmatics are at increased cardiovascular disease risk, which has been linked to beta2(β2)-agonist use. Inhalation of β2-agonists increases sympathetic nerve activity (SNA) in healthy individuals, however the systemic impact of salbutamol in asthmatics using β2-agonists regularly is unknown. This study compared the systemic vascular responses to a clinical dose of salbutamol (Phase I) and following an acute increase in SNA (Phase II) in asthmatics and controls. Fourteen controls and 14 asthmatics were recruited for Phase I. On separate days, flow-mediated dilation (FMD) and peripheral arterial stiffness (pPWV) were evaluated at baseline and following either 400 μg inhaled salbutamol or a placebo inhaler. For Phase II, heart rate, blood pressure, vascular conductance, pPWV, and central (c)PWV were evaluated in response to a large increase in SNA brought on by cold-water hand immersion (i.e. cold-pressor test) or body-temperature water hand immersion (i.e. control) in 10 controls and 10 asthmatics. Following salbutamol, asthmatics demonstrated reduced FMD (-3.0%, p<0.05) and increased pPWV (+0.7m/s, p<0.05); however, salbutamol had no effect in controls. The cold-pressor test resulted in similar increases in blood pressure, vascular flow rates and conductance, pPWV, and cPWV in both asthmatics and controls, suggesting similar neurovascular transduction in asthmatics and controls. Inhaled Salbutamol leads to increased arterial stiffness and reduced FMD in asthmatics. As asthmatics and controls had similar vascular responses to an increase in SNA, these findings suggest asthmatics have heightened sympathetic responses to β2-agonists which may contribute to the increased cardiovascular risk in asthma.

Temporal dynamic modulation of acute stress on error processing in healthy males.

Error processing is critical for adaptive behaviors. Acute stress has been found to influence error processing. However, the neural dynamic correlates underlying this modulation remain elusive. To address this issue, we recruited 39 healthy male participants, who performed a two-session task before and after an acute stress test while their behavioral and EEG data were recorded. The participants were randomly exposed to either a stress condition (Maastricht Acute Stress Test) or a control condition. The stress test consisted of several hand immersion tasks (ice-cold water, 2°C) and mental arithmetic tasks. A color-word Stroop task was used to investigate the stress effect on error responses. Based on the level of stress-induced cortisol, the participants in the stress group were further classified as low (N=13) or high (N=13) cortisol responders. The results indicated that only in the high cortisol responders, the error-related negativity (ERN) amplitude was reduced after acute stress. In addition, the ∆ERN in the high cortisol responders was significantly smaller than that in the low cortisol responders. These results suggest that acute stress impairs error detection. However, the error positivity amplitudes increased in the stress group compared to the control group, indicating that acute stress leads to greater error assessment. Taken together, these results suggest that acute stress impairs error detection, which is modulated by individuals' response level following acute stress, and leads to more emotional and/or motivational responses to the error signal once the error is consciously realized.

Associations of self-report and actigraphy sleep measures with experimental pain outcomes in patients with temporomandibular disorder and healthy controls

ObjectiveDiscrepancies between self-reported and actigraphy sleep measures are common, producing ambiguity about which are better predictors of experimental pain outcomes. The current study tested if pain intensity during and situational pain catastrophizing following experimental pain were differentially predicted by self-reported or actigraphy sleep measures in patients with chronic temporomandibular disorder (TMJD) or healthy controls (HCs). MethodsForty patients with TMJD and 20 HCs completed self-report sleep measures (Pittsburgh Sleep Quality Index, PSQI; Insomnia Severity Index, ISI; PROMIS Sleep-Related Impairment [SRI] and Sleep Disruption [SD]), underwent an experimental pain induction consisting of four consecutive cold-water hand immersions, and provided pain intensity and situational pain catastrophizing ratings. Participants also wore an actigraphy watch and completed sleep diaries for seven days, which were averaged for actigraphic indices of total sleep time, sleep efficiency, wake after sleep onset, and self-reported sleep quality and restfulness. ResultsIndividuals with TMJD reported higher pain intensity during experimental pain (M = 65.81 vs. 47.77, p = .007) and self-reported worse sleep compared to HCs (all p's < 0.02, Cohen's D = 0.73–1.25). No group differences emerged for actigraphy measures (all p's > 0.05, Cohen's D = 0.05–0.53). Sleep variables did not interact with group to predict responses to experimental pain (all p's > 0.05). Across groups, PROMIS-SRI predicted pain intensity (β = 0.36, p = .008) and catastrophizing (β = 0.36, p = .009) after controlling for multiple comparisons, smoking, medications, and age. ConclusionSelf-reported sleep (but not actigraphy) measures differentiate patients with TMJD from HCs. Sleep-related interference may place people at particular risk for higher pain intensity and catastrophizing following experimental pain.

Gender Variations in Electrodermal Activity among Medical Students in Response to Cold Pressor Test

Objectives&#x0D; To evaluate &amp; compare the electrodermal activity(EDA) among males and females in response to cold pressor test. Thus know the differences in autonomic functions in males &amp; females.&#x0D; Materials &amp; Method&#x0D; In this experimental study Galvanic skin response(GSR) was the parameter measured for EDA. The sample size of our study was 70 MBBS students (35 males &amp; 35 females)&#x0D; Cold pressor test was performed by immersing hand in cold water (temp 4°C to 6°C) &amp;changes in electrodermal activity(GSR) was recorded by using Biochart (version 1.0) device in our research lab.&#x0D; Results&#x0D; There was a significant increase in GSR after immersion of hand in cold water both in males and females. The baseline GSR value, GSR after immersion in cold water &amp; the recovery GSR value were significantly higher in males compared to females.&#x0D; Conclusion&#x0D; There is substantial evidence of gender difference in the functioning of the autonomic system, including specific effects of both male &amp; female sex hormones. As a generalisation, at least in humans there is a preponderance of sympathetic mediated responses in males and of parasympathetic in females.&#x0D; Our data show that EDA(GSR) is such a simple and non invasive method that can be used reliably to measure the autonomic nervous system functions i.e., the sympathetic over activity during cold induced acute pain.

Effect of one‐time successive immersion of the right hand into ice‐cold and warm water on blood pressure in prehypertensives

An early diagnostic and awareness of hypertension are crucial for controlling and prevention from further its development. The dysfunction of the autonomic nervous system (ANS) is a cornerstone of hypertension pathophysiology which underlies the initiation and development of hypertension. The HRV is commonly used for the evaluation of ANS activity. Though physiological/therapeutic effects of hydrotherapy for maintaining health, preventing, and treating the diseases, were well documented, the scientific base of these effects till now remains unclear.The 79 normotensive and 76 prehypertensive men, 102 normotensive and 50 prehypertensive women (117.4±0.6 mm Hg and 135.0±1.0 mm Hg, 111.1±0.6 mm Hg and 126.3±0.8 mm Hg for SBP, respectively) were enrolled from V.N. Karazin Kharkiv National University student population. All of them gave written informed consents.The ECG was continually recorded during the 5‐minutes resting stage and cold‐warm test (CWT): 5‐minutes immersion of the right hand into warm water (37°C) following by 1‐minute immersion of the hand into the ice‐cold water. HR, LnLF and HF HRV power were obtained by digital 2‐channel ECG amplifier (CardioLab 2010, Ukraine). HRV was assessed in the frequency‐domain analysis during the resting and warm‐water stages. SBP and DBP were recorded at the end of the resting and warm‐water stages by means the automatic digital sphygmomanometer (Nissei WS‐1011, Ltd, Japan) and MBP was calculated. Three‐way repeated measure MANOVA was used to compare HR, MBP, LnLF, LnHF HRV power by sex, the presence of prehypertension, and CWT. Two‐way MANOVA was used to analyze the possible effect of sex and prehypertension on cardiovascular and HRV responses to cold‐warm test. Statistical analysis was performed with the SPSS statistical program, version 22.During CWT the HR decreased significantly compared with the resting stage in normotensive and prehypertensive groups (P&lt;0.001 for both), MBP increased in normotensive subjects (P=0.032) while decreased in the prehypertensive group (P&lt;0.001). The LnHF power widely used as an index of cardiovagal activity tended to be increased in normotensive subjects (P=0.054) while the LnLF power indicating, according to our hypothesis, an index of sympathoinhibition, increased only in the normotensive group at high significant level (P=0.003).Sex differences were found between normotensive subjects in ΔHR, ΔLnLF, and ΔLnHF HRV power, such that LnLF and LnHF increased more and HR decreased more in normotensive women than in men (P=0.034, P=0.010, and P=0.015, respectively) indicating that reduction of HR due to activation of cardiovagal activity and sympathoinhibition was higher in normotensive women.So, during CWT the increase in parasympathetic activity and sympathoinhibition led to the reduction of HR in normotensive subjects, while prehypertensive subjects demonstrated the decrease of both HR and MBP without change of HRV indices possibly due to the reduction of tonic activity of the sympathetic nervous system. This cold‐warm test may be used for early diagnostic of hypertension since the MBP in normotensives significantly increased and in prehypertensives decreased at high significant level.This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Carotid Artery Reactivity Predicts Events in Peripheral Arterial Disease Patients.

Patients with peripheral arterial disease (PAD) have increased risk on future cerebro- and cardiovascular events. Our aim was to examine whether carotid artery reactivity (CAR; a novel, simple procedure to examine endothelial function) predicts cardiovascular events in PAD patients. Increased risk for future cardiovascular events in PAD patients is likely related to endothelial dysfunction, highlighting the necessity for simple assessment of endothelial function. A total of 172 PAD patients (68 ± 10 years, 67% male) underwent the CAR, which involves ultrasound measurement of carotid artery diameter during sympathetic stimulation produced by 90-second hand immersion in 4°C ice-water (ie, cold pressor test). CAR-responses were dichotomized into carotid constriction or dilation. We recorded cardiac and cerebrovascular events, mortality, and clinical progression to percutaneous transluminal angioplasty or loss of patency during 12-month follow-up. Eighty-two PAD patients demonstrated carotid constriction and 90 patients demonstrated dilation. PAD patients with carotid constriction showed more cardiovascular events compared to patients with dilation (Kaplan-Meier Log rank; P < 0.05). Cox proportional hazard models showed that patients with carotid constriction continued to show higher risk for cardiovascular events [hazard ratio: 4.1; 95% confidence interval (CI), 1.3-12.5] and clinical progression (hazard ratio: 2.0; 95% CI, 1.2-3.3), even after adjustment for other risk factors. Ankle brachial pressure index and carotid intima-medial thickness alone did not predict (cardiovascular) event or improve risk assessment beyond that provided by CAR. Carotid vasoconstriction identifies PAD patients with a 4-fold increased risk for future cardiovascular events and 2-fold increased risk for clinical deterioration. CAR provides a simple, novel strategy to predict cardiovascular events and progression in PAD patients. www.trialregister.nl/trialreg/index.asp, NTR-4117.

(352) Sex Differences in Sensory Processing: The Role of Stimulus Modality ad Psychological Factors

The experience of pain varies greatly from person to person. Many factors affect individual differences in pain, including sex and psychological factors. Previous studies have separately examined the effects of sex and psychological factors on pain, but most have not examined them in combination. The aim of this preliminary, exploratory analysis was to investigate sex differences in pain in a large sample to determine how pain responses and psychological measures of males compare to those of females using multiple quantitative sensory testing paradigms and multiple psychological measures. 141 participants (55 males, 86 females, mean age=29.1±6.8) were exposed to noxious heat, cold, and non-noxious audio stimuli. Participants were asked to rate their pain intensity and unpleasantness from thermal stimuli and the loudness of auditory stimuli. Psychological measures included the Barratt Impulsiveness Scale, Positive and Negative Affect Scale, PROMIS Anxiety, PROMIS Depression, PROMIS Pain Interference, and Pain Catastrophizing Scales. Univariate analyses and multiple linear models were constructed. Significant sex differences were found for cold and auditory stimuli but not heat. Females had lower cold tolerance during cold water hand immersion (means: males=76.2 seconds, females=59.7 seconds; p=.010). However, for 0.5°C cold phasic contact stimuli, males had greater pain intensity ratings (means: males=1.8, females=1.1; p=.030), and pain unpleasantness ratings (means: males=1.5, females= 0.9; p=0.040). Males had greater sensitivity to auditory stimuli as demonstrated by higher auditory unpleasantness ratings (means: males=4.1, females= 3.1; p=.049). Sex differences in psychological measures were found only for anxiety, which was greater in females (means: males=11.2, females=13.7; p=.006) and impulsivity, which was greater in males (means: males=56.0, females=51.7; p=.003). After adjusting for anxiety and impulsivity, the sex differences in cold pain tolerance, contact cold pain, and auditory sensitivity were not significantly different. Thus, sex differences in sensory processing are modality specific but may arise from sex differences in psychological factors.

Dermal Advanced REACH Tool (dART)-Development of a Dermal Exposure Model for Low-Volatile Liquids.

This article describes the development of a mechanistic model for underpinning the dermal Advanced REACH Tool (dART), an extension of the existing ART model and its software platform. It was developed for hand exposure to low volatile liquids (vapour pressure ≤ 10 Pa at 20°C) including solids-in-liquid products. The model is based on an existing conceptual dermal source-receptor model that has been integrated into the ART framework. A structured taxonomy of workplace activities referred to as activity classes are adopted from ART. Three key processes involved in mass transport associated with dermal exposure are applied, i.e. deposition, direct emission and contact, and transfer. For deposition, the model adopts all the relevant modifying factors (MFs) applied in ART. In terms of direct emission and contact (e.g. splashes) and transfer (e.g. hand-surface contacts), the model defines independent principal MFs, i.e. substance-related factors, activity-related factors, localized- and dispersion control and exposed surface area of the hands. To address event-based exposures as much as possible, the model includes crucial events during an activity (e.g. hand immersions) and translates objective information on tools and equipment (manual or automated) to probable events (e.g. splashes) and worker behaviours (e.g. surface contacts). Based on an extensive review of peer-reviewed literature and unpublished field studies, multipliers were assigned to each determinant and provide an approximated (dimensionless) numerical value. In the absence of (sufficient) evidence, multipliers were assigned to determinants based on assumptions made during discussions by experts in the consortium. A worked example is presented to illustrate the calculation of hand exposure for a specific scenario. The dART model is not yet implemented in the ART software platform, and a robust validation of the model is necessary to determine its predictive ability. With advancing knowledge on dermal exposure and its determinants, this model will require periodic updates and refinements, in addition to further expansion of the applicability domain of the model.

The Association Between Conditioned Pain Modulation and Manipulation-induced Analgesia in People With Lateral Epicondylalgia.

Objectives:Conditioned pain modulation (CPM) and manipulation-induced analgesia (MIA) may activate similar neurophysiological mechanisms to mediate their analgesic effects. This study assessed the association between CPM and MIA responses in people with lateral epicondylalgia.Materials and Methods:Seventy participants with lateral epicondylalgia were assessed for CPM followed by MIA. A single assessor measured pressure pain thresholds (PPT) before, during, and after cold water immersion (10°C) of the asymptomatic hand and contralateral lateral glide (CLG) mobilization of the neck. For analyses, linear mixed models evaluated differences in CPM and MIA responses. Pearson partial correlations and regression analyses evaluated the association between CPM and MIA PPT.Results:There was a significant increase (CPM and MIA, P<0.001) in PPT from baseline during the interventions (CPM mean: 195.84 kPa for elbow and 201.87 kPa for wrist, MIA mean: 123.01 kPa for elbow and 126.06 kPa for wrist) and after the interventions (CPM mean: 126.06 kPa for elbow, 114.24 kPa for wrist, MIA mean: 123.50 kPa for elbow and 122.16 kPa for wrist). There were also significant moderate and positive partial linear correlations (r: 0.40 to 0.54, P<0.001) between CPM and MIA measures, controlling for baseline measures. Regression analyses showed that CPM PPT was a significant predictor of MIA PPT (P<0.001) and the models explained between 73% and 85% of the variance in MIA PPT.Discussion:This study showed that CPM and MIA responses were significantly correlated and that the CPM response was a significant predictor of MIA response.

Effect of temperature on muscle endurance in healthy adults

Background: The local application of cold or heat on the muscle is known to affect the muscle endurance which can be measured using the handgrip dynamometer. Aims and Objectives: The present study has been done with the objective of studying the effects of cold water immersion and rewarming on the endurance of the hand and forearm muscles. Materials and Methods: The study included 40 healthy medical students. The dominant hand and forearm were immersed in cold water for 5 min after which muscle endurance was determined using the handgrip spring-type dynamometer and this was followed by immersion of hand and forearm in hot water after which muscle endurance was again determined. Paired t-test was used to analyze the data. Results: On comparing the muscle endurance after cold water immersion and rewarming, the results showed that there was a statistically significant improvement (P < 0.05) in the muscle endurance after rewarming. Conclusion: The results demonstrate an increase in the hand and forearm muscle endurance after rewarming which may be beneficial for people working in meat packaging and cold storage industries. These industrial workers can immerse their hands in rewarming sinks intermittently which might enhance their work performance.

Relation between finger cold-induced vasodilation and rewarming speed after cold exposure

PurposeThe risk for local cold injuries has been linked to poor cold-induced vasodilation (CIVD) during cold exposure and to poor rewarming after cold exposure. The purpose of this study is to establish the relation between CIVD and rewarming speed.MethodsTwelve participants immersed one hand in ice water for 30 min to evoke CIVD and the other hand in ice water for 10 min to investigate the rewarming profile. The ring, middle and index fingertip temperatures were monitored during hand immersion and the resistance index of frostbite (RIF) was calculated. RIF depends on minimal (Tmin) and mean (Tmean) finger skin temperature and onset time. Rewarming was quantified using an infrared imaging system and the rewarming speed over 19 min was determined.ResultsTmin (5.8 ± 3.0 °C) and Tmean (10.4 ± 3.0 °C) caused non-distinctive contributions to the total RIF-scores so that onset time (12.7 ± 3.1 min) became the dominant factor. A significant negative correlation between RIF and rewarming speed was found (rs = − 0.60, p = 0.041).ConclusionsThe negative relation between RIF and rewarming speed may be explained by the common observation that onset time relates to the temperature of fingertip tissue, while Tmin, Tmean and rewarming speed relates to body thermal status. The rewarming test is to be preferred over the CIVD test in terms of ease of use, but the predictive value of the rewarming test for cold injuries is limited, cannot replace the RIF since onset time of finger vasodilation is not included and should be further investigated.

Conditioned pain modulation identifies altered sensitivity in extremely preterm young adult males and females

BackgroundConditioned pain modulation is a potential biomarker for risk of persistent pain. As early-life experience can alter subsequent somatosensory processing and pain response, we evaluated conditioned pain modulation after extremely preterm birth. MethodsThis observational study recruited extremely preterm (<26 weeks gestation; n=98) and term-born control (n=48) young adults (19–20 yr) from the longitudinal EPICure cohort. Pressure pain threshold (PPT; variable test stimulus lower leg) was measured before, during, and after a conditioning stimulus (contralateral hand immersion; 5°C water; 30 s). Questionnaires assessed current pain, medication use, anxiety, and pain catastrophising. ResultsFor participants tolerating conditioning, there were significant main effects of extremely preterm status, sex, and time on PPT during and after hand immersion. Inhibitory modulation was evoked in 64/98 extremely preterm (3, no change) and 38/48 term-born control (3, facilitation) subjects. The conditioned pain modulation effect (percentage change in PPT) did not differ between the extremely preterm and term-born control groups {53% [95% confidence interval (CI): 41–65] vs 57% [95% CI: 42–71]}. Reduced cold tolerance (<20 s) hampered conditioned pain modulation quantification in a higher proportion of extremely preterm participants [extremely preterm vs term-born control: 31/98 (32%) vs 7/48 (15%); P=0.03]. One-third of extremely preterm females withdrew the hand before parallel PPT (<15 s), and had lower baseline PPT than term-born control females [4.9 (95% CI: 4.8–5.1) vs 5.3 (95% CI: 5.1–5.5) ln kPa; P=0.02]. Higher anxiety, pain catastrophising, and medication use correlated with pain intensity, but not conditioned pain modulation effect. ConclusionsCold conditioning evoked inhibitory modulation in the majority of young adults and identified a subgroup of extremely preterm females with increased baseline sensitivity. Early-life experience and sex/gender should be considered when evaluating persistent pain risk with conditioned pain modulation.

HYPNOTIZABILITY AND PAIN MODULATION: A Body–Mind Perspective

The study investigated whether the cardiac activity and cognitive–emotional traits sustained by the behavioral inhibition/activation system (BIS/BAS) may contribute to hypnotizability-related pain modulation. Nociceptive stimulation (cold-pressor test) was administered to healthy participants with high (highs) and low (lows) hypnotizability in the presence and absence of suggestions for analgesia. Results showed that heart rate increased abruptly at the beginning of nociceptive stimulation in all participants. Then, only in highs heart rate decreased for the entire duration of hand immersion. During stimulation with suggestions of analgesia, pain threshold negatively correlated with heart rate. BIS/BAS activity partially accounted for the observed hypnotizability-related differences in the relation between cardiac interoception and pain experience.

Koroška 8000 Himalayan expedition: digit responses to cold stress following ascent to Broadpeak (Pakistan, 8051m).

Cold-induced vasodilatation (CIVD) is a peripheral blood flow response, observed in both the hands and feet. Exercise has been shown to enhance the response, specifically by increasing mean skin temperatures (Tsk), in part due to the increased number of CIVD waves. In contrast, hypobaric hypoxia has been suggested to impair digit skin temperature responses, particularly during subsequent hand rewarming following the cold stimulus. This study examined the combined effect of exercise and hypobaric hypoxia on the CIVD response. We compared the CIVD responses in the digits of both the hands and feet of a team of alpinists (N = 5) before and after a 35-day Himalayan expedition to Broadpeak, Pakistan (8051m). Five elite alpinists participated in hand and foot cold water immersion tests 20 days before and immediately upon return from their expedition. The alpinists summited successfully without supplemental oxygen. Post-expedition, all alpinists demonstrated higher minimum Tsk in their hands (pre: 9.9 ± 1.1, post: 10.1 ± 0.7°C, p = 0.031). Four alpinists had either greater CIVD waves, and, consequently, higher mean Tsk in their hands, or higher recovery temperatures (pre: 26.0 ± 5.5°C post: 31.0 ± 4.1°C, p = 0.052), or faster rewarming rate (pre: 2.6 ± 0.5°Cmin-1 post: 3.1 ± 0.4°Cmin-1,p = 0.052). In the feet, the responses varied: 1/5 had higher wave amplitudes and 1/5 had higher passive recovery temperatures, whereas 3/5 had lower mean toe temperatures during cold exposure. The results of the cold stress test suggest after a 35-day Himalayan expedition, alpinists experienced a slight cold adaptation of the hands, but not the feet.