Skin Potential Research Articles

The regenerative potential of skin and the immune system.

Skin has the natural ability to heal and replace dead cells regulated by a network of complex immune processes. This ability is conferred by the population of resident immune cells that act in coordination with other players to provide a homeostatic environment under constant challenge. Other than providing structure and integrity, the epidermis and dermis also house distinct immune properties. The dermal part is represented by fibroblasts and endothelial cells followed by an array of immune cells which includes dendritic cells (DCs), macrophages, mast cells, NK-cells, neutrophils, basophils, eosinophils, αβ T lymphocytes, B-cells and platelets. On the other hand, the functionally active immune cells in the epidermis comprise keratinocytes, DCs, NKT-cells, γδ T cells and αβ T cells (CD4+ and CD8+). Keratinocytes create a unique microenvironment for the cells of the immune system by promoting immune recognition and cellular differentiation. T lymphocytes exhibit tissue-specific tropism toward the epidermis and the lymphatic drainage system important for their function in immune regulation. This diversity in immune regulators makes the skin a unique organ to overcome pathogenic or foreign invasion. In addition, the highly coordinated molecular events make the skin an attractive model to understand and explore its regenerative potential.

Arabica Coffee (Coffea Arabica) Fruit Skin Potential Towards the Increase of Fibroblast Cells Amount Within Socket Post Tooth Extraction of Male Wistar Mouse

Background: Tooth extraction can cause wound in hard tissue and soft tissue inside oral cavity. Wound healing process involves cell proliferation especially fibroblast cells. To accelerate fibroblast cell proliferation alternative substance that can accelerates wound healing process is needed which is arabica coffee fruit skin. Arabica coffee fruit skin contains substances such as polyphenols, tannin, chlorogenic acid, and caffeine expected to be able to stimulate fibroblast cells amount. Objective: To understand arabica coffee fruit skin potential towards increase in number of fibroblast cells on the socket after tooth extraction. Method: The design of this research was post test only control group with sample size of 24 wistar mouse. The samples used were divided into two groups which are control and treatment group. Then treatment was given in 3 days, 5 days, and 7 days. Then they were decapitated to undergo tissue processing with HE coloring and post tooth extraction socket fibroblast cells counting. Acquired data then analyzed used One Way ANOVA and LSD test. Result: Fibroblast cell amount increased significantly (p<0.05) in treatment group compared to control group. Conclusion: Arabica coffee fruit skin potentially increase fibroblast cells amount in socket post tooth extraction of male wistar mouse. Keywords: tooth extraction; wound healing; fibroblast cells

RESEARCH OF HUMAN FATIGUE AND MEASUREMENT PARAMETERS FOR WORKABILITY ASSESSMENT

Human fatigue is reduced working capability for certain period of time as the result of unusual or prolonged workload. Fatigue arises when the body’s energy requirements exceed its supply. Fatigue first manifests as reduced concentration capability causing movement coordination and precision disruption leading to decreasing workability. Fatigue is an object of research in physiology, psychology, work ergonomics, medicine, and biotechnology where each domain has a focus on mental fatigue. The functional state in the context of professional activity is defined as a complex of characteristics of functions and qualities that determine the fulfilment of labour activity. Furthermore, a comprehensive estimation of subject functional state in combination with other factors like subject self-assessment and objective performance tests (cognitive load tests) is a necessary input for the evaluation of workability and efficiency on task. The heterogeneous nature of fatigue as a systemic manifestation requires analysis of multiple key parameters which are relevant to the specific type. The current feasibility study focuses on human biological signal from electrical activity of heart, brain, muscles and skin potentials as well as temperature, position, and respiration to obtain diagnostic parameters reflecting the state of cardiovascular, muscles, and central nervous systems for physiological monitoring of vital signs. The fatigue physiological parameter and feature formalization aim to support the development of a platform with complex passive multi-level fatigue monitoring system and workability evaluation system designed in order to provide an integrated service.

Highly transparent, stretchable, and rapid self-healing polyvinyl alcohol/cellulose nanofibril hydrogel sensors for sensitive pressure sensing and human motion detection

Wearable sensors have emerged as favored novel devices for human healthcare. Current sensors, however, suffer from low sensitivity, non-transparency, and lack of self-healing ability. In this study, we synthesized a polyvinyl alcohol/cellulose nanofibril (PVA/CNF) hydrogel with dual-crosslinked networks for highly transparent, stretchable, and self-healing pressure and strain sensors. The hydrogel contains dynamic borate bonds, metal–carboxylate coordination bonds, and hydrogen bonds, all of which contribute to the hydrogel’s superior dimensional stability, mechanical strength and flexibility, and spontaneous self-healing ability as compared to traditional PVA hydrogels. The developed hydrogel has a moderate modulus of 11.2 kPa, and a high elongation rate of 1900%. It spontaneously self-heals within 15 s upon contact without any external stimuli, has a high transmittance of over 90%, and has excellent compatibility with human fibroblasts. The capacitive sensor developed based on the PVA/CNF hydrogel has high sensitivity to very subtle pressure changes, such as small water droplets. When used as a strain sensor, it was capable of detecting and monitoring various human motions such as finger, knee, elbow, and head movements, breathing, and gentle tapping. The developed hydrogel and sensors not only show great potential in electronic skin, personal healthcare, and wearable devices, but may also inspire the development of transparent, intelligent skin-like sensors.

Human neonatal stem cell‐derived skin substitute improves healing of severe burn wounds in a rat model

Conventional approaches can repair minor skin injuries; however, severe burn injuries require innovative approaches for efficient and better wound repair. Recent studies indicate that stem cell-based regenerative therapies can restore severe damaged skin both structurally and functionally. The current study aims to evaluate the wound healing potential of skin substitute derived from human neonatal stem cells (hNSCs) using a severe burn injury rat model. Amniotic epithelial cells (AECs) and mesenchymal stem cells (MSCs) were isolated from placenta (a source of neonatal stem cells) by explant culture method. After characterization, AECs and umbilical cord-MSCs were differentiated into keratinocyte and fibroblasts, respectively. Morphological changes, and expression of corresponding keratinocyte and fibroblast specific markers were used to verify differentiation into respective lineage. A skin substitute was developed by mixing hNSCs-derived skin cells (hNSCs-SCs) in plasma for transplantation in a rat model of severe burn injury. Results indicated that placenta-derived AECs and MSCs were efficiently differentiated into skin cells, that is, keratinocytes and fibroblasts, respectively, as indicated by morphological changes, immunostaining, and polymerase chain reaction analysis. Further, transplantation of hNSCs-SCs seeded in plasma significantly improved basic skin architecture, re-epithelization rate, and wound healing concurrent with reduced apoptosis. In conclusion, neonatal stem cell-derived skin substitute efficiently improved severe burn wounds in a rat model of burn injury. Unique properties of placenta-derived stem cells make them superlative candidates for the development of "off-the-shelf" artificial skin substitutes for future use.

A Circuit for Simultaneous Measurements of Skin Electrical Conductance, Susceptance, and Potential.

A circuit is presented that enables measurement of skin electrical conductance, susceptance, and potential simultaneously beneath the same monopolar electrode. Example measurements are shown to confirm the function of the circuit. The measurements are also in accordance with earlier findings that changes in skin conductance and potential do not always correspond and hence contain unique information.

Impact of obesity and gender differences on electrodermal activities.

The widespread use of electrodermal activity (EDA) as a measuring tool in sympathetic nervous system activity researches has resulted in a wide variety of publications on EDA. Yet, the influences of obesity and gender differences in the responses and levels of EDA have not been studied carefully. This study aims to investigate the impacts of obesity and gender differences on EDA parameters. To this end, EDA responses and levels were recorded from 36 (18 males and18 females) apparently healthy adult subjects nearly half of them are obese. EDA measures were induced by three different stimuli and the EDA responses and levels were compared as a function of obesity and gender differences for all stimuli. It was found that EDA parameters, in particular, skin conductance responses (SCRs) were significantly different between obese and non-obese subjects for both genders. In addition, it was found that the change in skin susceptance levels (SSLs) was statistically significant only among females. The investigation also showed that the gender difference has a crucial role in skin potential levels (SPLs) for obese subjects. The outcome results led to the conclusion that the phasic SCRs were strongly related to BMI, while tonic SPLs were related to gender differences.

A7546 To study autonomic variability in offsprings of hypertensive parents in lucknow using handgrip dynamometer and galvanic skin response

Objectives: Positive family history of hypertension is one of the risk factors for being hypertensive in future life for children. Young adults with hypertensive first degree relatives constitute a special risk group that should be closely monitored. Early detection of proneness to hypertension may help an individual to lead a healthy life by altering his/her lifestyle. The aim of the present study is to investigate the autonomic variability in offspring of hypertensive parents. Methods: This is a case control study. In this study 60 healthy young subjects, (n = 60; 30 cases, 30 controls, age: 18–25 years both male and female) were chosen. The blood pressure of the participants was recorded using a electronic blood pressure instrument (Cannon). The participant was asked to sustain isometric handgrip at one third of Maximum voluntary contraction(MVC). At the completion of one minute, blood pressure was measured. Three minutes after the handgrip test, the blood pressure was noted again (recovery). GSR was recorded using Medicaid Polyrite machine. Results: In cases the diastolic blood pressure after 3 minutes of withdrawal of stressor was seen to be significantly higher (p value < 0.05) than baseline diastolic blood pressure. GSR recording was found to be significantly lower in cases than in controls (p value < 0.05). The change in skin potential is in response to stress which alters sympathetic activity. Conclusion: Once stimulated by a stressor, sympathetic system causes rise in blood pressure. The persons who show higher cardiovascular reactivity to a stressor but slower rate of recovery after the withdrawal of the stressor indicate that their autonomic control system is weak. Decreased GSR recordings also demonstrate altered sympathetic activity.

Influence of Relative Humidity on Electrodermal Levels and Responses

Background/Aim: Electrodermal activity (EDA) is a widely used measure in psychophysiological research, and its use in wearable devices has grown in recent times. It is recommended to have proper conditions for EDA measurement, and skin hydration is one factor that has a significant influence. It is, however, not known to what extent the ambient humidity influences the recording. This study explored the influence of relative humidity (RH) on EDA levels, and also the responses using a new technique for simultaneous recording of all measures of EDA: skin conductance (SC), skin susceptance (SS), and skin potential (SP) at the same skin site. Methods: A total of 10 healthy subjects were exposed to environments of low and high RH while EDA measures were recorded, including cognitive, visual and breathing stimuli for evoking electrodermal responses of different origin. EDA levels and responses were compared between the two humidity levels for all stimuli and all EDA measures. Results: It was found that EDA levels, in particular for SC and SS, were significantly increased during high humidity exposure, but that the change in EDA responses (SC, SS, and SP) was not statistically significant (p > 0.05, paired t test). Conclusion: This suggests that ambient humidity influences the recording of EDA levels and is important to consider when these parameters are used, but is not important in the recording or analysis of EDA responses.

Peter H. Venables (1923–2017)

Peter H. Venables (1923–2017)

A pilot study on skin potential recordings as a measure of nociception in pain-free dogs and humans, and in dogs with persistent pain

Abstract The Pain Trace™ device can detect changes in the skin's electrical potentials claimed to be associated with pain related alterations in the sympathetic and parasympathetic nervous system activity. Positive voltages represent the absence of major pain, whereas negative voltages represent moderate to severe pain. Unlike in humans and horses, no baseline skin potential recordings have been reported in dogs. In study Part 1 baseline skin potentials were recorded in healthy dogs and compared to readings obtained in human volunteers. In dogs, data were recorded with electrodes placed at three separate sites: neck, axilla, and thorax. In humans, data were collected from the palms. Readings over a 90-second period were averaged and comparisons between groups were performed using the Kruskal-Wallis test. All voltage recordings were positive. Readings in dogs had greater variability. Recordings from the thorax were more homogeneous, this being the reason why this site was chosen for study Part 2. No significant differences in recordings were noted between pain-free dogs and humans. The main hypothesis was that shifting from positive to negative skin potential voltages serves as an indicator of canine patients sensing moderate to severe pain. Therefore, we obtained preoperative readings from dogs with cranial cruciate ligament disease that were experiencing associated persistent pain, and compared these data with readings from pain-free dogs (thorax). In dogs undergoing surgery, all pre-surgery voltage readings were positive and thus no consistent relationship between skin potential recordings and pain perception could be established. Further investigation is needed to confirm any relationship between skin potential and pain severity in dogs.

Сравнение частотных компонент ЭЭГ и кожного потенциала (количественный анализ)

In the experiment, a local EEG (Fp1) and a skin potential (SP) were recorded when anagrams were tested and several test tasks were performed. The main goal was to compare the structure and dynamics of the frequency components of the local EEG and SP based on a quantitative analysis of the obtained data. With the help of frequency analysis, profiles of frequency dynamics of the total EEG and SP, as well as histograms of distributions of their frequency components, were constructed, among which six typical patterns were singled out. In the series with simultaneous registration of EEG and SP, a high positive correlation of their total signals is established (the minimax range is from 0.70 to 0.94). Along with this, in the frequency patterns of the EEG and SP, some differences in the temporal distribution of the frequency components are found with a shift in the difference of the EEG-SP towards negative values. The possible nature of the general properties of the high-frequency dynamics of the EEG and SP is discussed. The obtained data are important, in particular, when interpreting the results of experiments with the simultaneous recording of several psychophysiological indices.

Phosphodiesterase 4B plays a role in benzophenone-3-induced phototoxicity in normal human keratinocytes

Benzophenone-3 (BP-3), which is extensively used in organic sunscreen, has phototoxic potential in human skin. Phosphodiesterase 4B (PDE4B) has a well-established role in inflammatory responses in immune cells. Currently, it is unknown if PDE4B is associated with BP-3-induced phototoxicity in normal human keratinocytes (NHKs). We found that BP-3 significantly increased PDE4B expression in ultraviolet B (UVB)-irradiated NHKs. Notably, BP-8, a sunscreen agent that shares the 2-hydroxy-4-methoxyphenyl methanone moiety with BP-3, also upregulated PDE4B expression in NHKs. Upon UVB irradiation, BP-3 upregulated the expression of pro-inflammatory factors, such as prostaglandin endoperoxide synthase 2, tumor necrosis factor α, interleukin 8, and S100A7, and downregulated the level of cornified envelope associated proteins, which are important in the development of the epidermal permeability barrier. The additive effects of UVB-activated BP-3 on the expression of both pro-inflammatory mediators and cornified envelope associated proteins were antagonized by treatment with the PDE4 inhibitor rolipram. The BP-3 and UVB co-stimulation-induced PDE4B upregulation and its association with the upregulation of pro-inflammatory mediators and the downregulation of epidermal differentiation markers were confirmed in a reconstituted three dimensional human epidermis model. Therefore, PDE4B has a role in the mechanism of BP-3-induced phototoxicity.

Continuously Producible Ultrasensitive Wearable Strain Sensor Assembled with Three-Dimensional Interpenetrating Ag Nanowires/Polyolefin Elastomer Nanofibrous Composite Yarn.

Fiber-shaped strain sensors with great flexibility and knittability have been tremendously concerned due to the wide applications in health manager devices, especially in human motion detection and physiological signal monitoring. Herein, a novel fiber-shaped strain sensor has been designed and prepared by interpenetrating Ag nanowires (NWs) into polyolefin elastomer nanofibrous yarn. The easy-to-obtain structure and simple roll-to-roll process make the continuous large-scale production of nanofibrous composite yarn possible. The continuous and alternating stretching and releasing reversibly change the contact probability between AgNWs in this interpenetrating network, leading to the variations of electrical resistance of the sensor. The gauge factors of strain sensors are calculated to be as high as 13920 and the minimum detection limit is only 0.065%. In addition, the strain sensor shows excellent durability during 4500 cycles with the strain of 10%. The response times of stretching and releasing strains are 10 and 15 ms, respectively. Furthermore, the strain sensor has been successfully applied in human motion detections both in single yarn and knitted fabrics. The result shows the practicability in applications of monitoring limbs movements, eye motion changes, artificial vocal cords, human pulse, and complex motions, which shows great potential in wearable sensors and electronic skin.

Hypoglycemic and hypolipidemic effects of different parts and formulations of bitter gourd (Momordica Charantia)

BackgroundCardiovascular diseases and diabetes are responsible for large number of deaths throughout the globe. Bitter gourd has the potential to become a component of the diet or a dietary supplement for diabetic and pre-diabetic patients owing to the presence of insulin like molecules. Recent investigations have suggested that bitter gourd extracts may ameliorate high fat diet induced obesity and hyperlipidemia in animal models. Moreover, its supplements in food result in lowering weight gain and visceral fat mass.MethodsThe current study was designed to investigate the nutraceutical potential of skin, flesh and whole fruit of bitter gourd cultivars against hyperglycemia and hyperlipidemia. For the purpose, various bitter gourd cultivars were procured from local market. Bio-evaluation studies were carried out on biochemical parameters using rodent experiment model.ResultsFrom results, it was revealed that maximum reduction in blood glucose skin 1.06%, flesh 2.65%, whole fruit 4.29%, total cholesterol skin 6.60%, flesh 6.04%, whole fruit 6.70%, low density lipoprotein skin 5.55%, flesh 6.81%, whole fruit 6.60%, and triglycerides skin 0.04%, flesh 3.38%, whole fruit 2.02%, were observed. Moreover, insulin skin 2.14%, flesh 3.52%, whole fruit 2.73%, production was slightly enhanced with improved levels of high density lipoprotein in whole fruit of bitter gourd.ConclusionOverwhelmingly, it may be inferred here that bitter gourd holds the potential to significantly improve diabetic conditions and associated late complications with no ill effects on body organs.

Reconstruction of parotidectomy and lateral skull base defects

The purpose of this review is to summarize the options for reconstruction of parotid and lateral skull base defects based on the size and functional requirements of the defect. Free grafts with dermal fat or acellular human dermis, superficial musculoaponeurotic system flaps, and sternocleidomastoid flaps have been successful in preventing Frey's syndrome and restoring facial contour defects after superficial and total parotidectomy. Lateral skull base resections often require reconstruction with pedicled or free flaps to restore extensive soft tissue and dural defects. Supraclavicular artery island flaps and submental flaps have been recently been gaining popularity for use for these purposes. Free tissue transfer remains the best reconstructive option for repair of large soft tissue and/or dural defects. The most reliable free flap for lateral skull base reconstruction is the anterolateral thigh flap, which is highly versatile because of its large skin paddle and potential for harvest with varying amounts of fascial and muscle tissue. Here we will summarize the most appropriate and widely used reconstructive options for parotid and lateral skull base defects of various sizes, discussing the most recent evidence pertaining to each technique along with advantages and limitations of each reconstructive strategy.

Comparative analysis of respiratory, skin and eye irritation potential of chemicals using Japanese GHS classification

Comparative analysis of respiratory, skin and eye irritation potential of chemicals using Japanese GHS classification

Electrodermal responses to discrete stimuli measured by skin conductance, skin potential, and skin susceptance.

Presently, electrodermal activity (EDA) is the preferred term for changes in electrical properties of the skin. Change in the skin conductance responses (SCRs) and skin potential responses (SPRs) due to external stimuli have previously been investigated in a number of studies, but very little for skin susceptance responses (SSRs) recorded simultaneously at the same skin site. This study aimed to investigate the association between the three parameters of EDA, skin conductance (SC), skin potential (SP), and skin susceptance (SS) responses generated by different types of psychological stimuli. SCRs, SPRs, and SSRs were recorded from 20 healthy test subjects simultaneously at the same skin area. EDA responses were induced by five different external stimuli, which were shown in the form of PowerPoint slides on a PC monitor that situated in front of participants. All stimuli evoked EDA responses, but with significantly different magnitudes, dependent on stimulus type. Both SC and SP waveforms yielded positive responses with respect to the stimuli; however, SS showed negative response and its role was found to be significant at low frequency (20Hz). This study illustrated that different discrete stimuli showed different passive and active electrodermal responses at the same skin site. SCRs, SPRs, and SSRs were dependent on the stimulus type, and the highest response was associated with the sound stimulus, which can be attributed to orienting response or startle reflex. In addition, it was found that the SSRs have a significant contribution at 20Hz. In spite of a high correlation found between average amplitude values of SCRs and SSRs, no significant association was seen between average amplitudes values of SPRs and SSRs, and between SCRs and SPRs.

Electrical Grounding Improves Vagal Tone in Preterm Infants

Background: Low vagal tone (VT) is a marker of vulnerability to stress and the risk of developing necrotizing enterocolitis in preterm infants. Electric fields produced by equipment in the neonatal intensive care unit (NICU) induce an electric potential measurable on the skin in reference to ground. An electrical connection to ground reduces the skin potential and improves VT in adults. Objectives: We aimed to measure the electric field strengths in the NICU environment and to determine if connecting an infant to electrical ground would reduce the skin potential and improve VT. We also wished to determine if the skin potential correlated with VT. Methods: Environmental magnetic flux density (MFD) was measured in and around incubators. Electrical grounding (EG) was achieved with a patch electrode and wire that extended to a ground outlet. We measured the skin potential in 26 infants and heart rate variability in 20 infants before, during, and after grounding. VT was represented by the high-frequency power of heart rate variability. Results: The background MFD in the NICU was below 0.5 mG, but it ranged between 1.5 and 12.7 mG in the closed incubator. A 60-Hz oscillating potential was recorded on the skin of all infants. With EG, the skin voltage dropped by about 95%. Pre-grounding VT was inversely correlated with the skin potential. VT increased by 67% with EG. After grounding, the VT fell to the pre-grounding level. Conclusion: The electrical environment affects autonomic balance. EG improves VT and may improve resilience to stress and lower the risk of neonatal morbidity in preterm infants.

Characterization of Cacao Fruit Skin for Active Carbon and Green Chemicals

&lt;p&gt;PThe potential of cacao fruit skin that has not been widely used by the community are encouraged to develop the cacao fruit skinas bio charcoal. One way to reduce the build up of biomass waste is by pyrolysis derived from combustion products that produce liquid smoke, charcoal and some gases (CO&lt;sub&gt;2&lt;/sub&gt;, H&lt;sub&gt;2&lt;/sub&gt;, and CO&lt;sub&gt;2&lt;/sub&gt;). The purpose of this research is to utilize cacao peel to get the liquid smoke of cacao skin and cacao charcoal. The result of this research showed that the skin of cacao fruit produce hemicellulose content of 21.06%, cellulose of 20.15% and lignin of 51.98%. The analysis result of carbon content of cacao skin activated charcoal from Luwu regency is 55.11%. FT-IR analysis of the cacao skin powder from Luwu regency showed that there were depolymerization for cellulose and hemicellulose contentsat the wave number of 1107.14 cm&lt;sup&gt;-1&lt;/sup&gt; andfound C-H of lignin at the wave number of 1730.15 cm&lt;sup&gt;-1&lt;/sup&gt;. The hydroxyl group (OH) appeared on the wave number of 3441.01 cm&lt;sup&gt;-1&lt;/sup&gt; and group of C = CH (Aromatic H) on the wave number of781.17 – 659.66 cm&lt;sup&gt;-1&lt;/sup&gt;. Crystallinity degree of cacao fruits skin from Luwu which was obtained from XRD analysis is 12.66%. The wasteutilization of this cacao fruit skin with pyrolysis technology is able to reduce carbon emissions and can be as a supporter of sustainable development program.&lt;/p&gt;