Advancements in non-invasive skin sampling: Clinical conditions characterization via the assessment of skin surface cytokine biomarkers

The skin is increasingly recognized as a biological active organ interacting with the immune system. Given that the epidermal skin layer actively releases various cytokines, non-invasive skin sampling methods could detect these cytokines, offering insights into clinical conditions. This study aims non-invasively measuring cytokine levels directly from the skin surface to characterize different inflammatory chronic disorders in the adult and elderly population: psoriasis, diabetes type 2, rosacea, chronic kidney disease (CKD) and aging. Cytokines IL-1β, IL-8 and IL-10 were sampled from healthy subjects and patients aged 18-80 using skin surface wash technique. A well with sterile phosphate-buffered saline solution was placed on the skin for 30 min, and the extracted solution was collected from the well for further cytokine levels analysis using ELISA assay. Results show distinct cytokine profiles in different pathological processes, healthy controls, affected and unaffected areas. Aging was associated with increased IL-1β, IL-8, and IL-10 levels in skin. In diabetes, IL-1β and IL-8 levels were elevated in lesional areas, while IL-10 levels were decreased in non-lesional skin. Psoriatic lesions showed elevated levels of IL-1β and IL-8. Rosacea patients had lower IL-10 levels in both lesional and non-lesional areas. CKD patients exhibited significantly lower IL-10 levels compared to healthy individuals. In conclusion, skin surface wash-derived cytokine profiles could serve as "alert biomarkers" for disease prediction, enabling early detection. Additionally, this method's cost-effectiveness allows pre-screening of molecules in clinical studies and holds potential as a tool for biomarkers and omics analysis, enhancing disorder characterization and disease management.

A cross-sectional cohort study on the skin microbiota in patients with different acne durations

Acne is a chronic disease that often persists for years. Skin microbial communities play an essential role in the development of acne. However, limited information is available about the dynamic patterns of skin microbiota in acne. This study aimed to characterize microbial community changes in skin pores and surfaces of acne patients with varying disease time. In this study, a total of 70 skin samples from 22 subjects were collected and sequenced using 16S rRNA amplicon sequencing. Although microbial compositions in skin pores were similar over time, significant differences in microbial structure were observed on the skin surface, with the dominance of Cutibacterium in the first 3 years and replacement by Staphylococcus in 4-6 years. Lactobacillus and Acinetobacter were more abundant in the normal group and continuingly decreased with disease time on the skin surface. Microbial networks further revealed substantial increases in microbial interactions in the 4-6 years group in both skin surfaces and pores. These results demonstrate that the skin microbiota alters with the disease duration and may provide a potential guide in redirecting skin microbiota towards healthy states.

In Vivo Assessment of Skin Surface Pattern: Exploring Its Potential as an Indicator of Bone Biomechanical Properties

The mechanical properties of bone tissue are the result of a complex process involving collagen-crystal interactions. The mineral density of the bone tissue is correlated with bone strength, whereas the characteristics of collagen are often associated with the ductility and toughness of the bone. From a clinical perspective, bone mineral density alone does not satisfactorily explain skeletal fragility. However, reliable in vivo markers of collagen quality that can be easily used in clinical practice are not available. Hence, the objective of the present study is to examine the relationship between skin surface morphology and changes in the mechanical properties of the bone. An experimental study was conducted on healthy children (n = 11), children with osteogenesis imperfecta (n = 13), and women over 60 years of age (n = 22). For each patient, the skin characteristic length (SCL) of the forearm skin surface was measured. The SCL quantifies the geometric patterns formed by wrinkles on the skin's surface, both in terms of size and elongation. The greater the SCL, the more deficient was the organic collagen matrix. In addition, the bone volume fraction and mechanical properties of the explanted femoral head were determined for the elderly female group. The mean SCL values of the healthy children group were significantly lower than those of the elderly women and osteogenesis imperfecta groups. For the aged women group, no significant differences were indicated in the elastic mechanical parameters, whereas bone toughness and ductility decreased significantly as the SCL increased. In conclusion, in bone collagen pathology or bone aging, the SCL is significantly impaired. This in vivo skin surface parameter can be a non-invasive tool to improve the estimation of bone matrix quality and to identify subjects at high risk of bone fracture.

Investigation of the precision of the Visia® complexion analysis camera system in the assessment of skin surface features

Background

The aim of this study was to independently investigate the precision of the high resolution Visia^® camera, from Canfield Scientific, to capture several skin surface features.

Method

Facial images of eight volunteers were taken with closed eyes and a relaxed face. The capture was conducted in a resting position within a positioning rig. Frontal view images were taken. In the first capture session, the images were captured three times in a row with the head steadily resting in the capture rig. Each volunteer then left the capture rig and returned to it one week later repositioning the face, and the capture was repeated three times. On the basis of this study, it was additionally investigated which number of study participants would be required in order to make a claim as to the reproducibility of the captures. As a possible approach to making this determination, a power analysis was considered. In order to conduct this analysis, it was necessary to determine which differences between individual image captures would be clinically acceptable. To answer this question, a subjective assessment of the repeated image captures for all study participants and for all skin surface features was conducted in order to identify any differences that were visible with the human eye.

Results

Differences in skin criteria of the eight volunteers in terms of means and standard deviations were collected for weeks one and two. For the criteria skin texture, UV spots, brown spots and porphyrins, these differences were less than 2% and for pores and red areas they were between 2% and 4%. The results for spots and wrinkles were around 6%. Looking at the differences between the data from week one and two as well as the standard deviations, these differences turned out to be relatively small. This finding also pointed to a quite good precision of the measurement technique. The subjective assessment of the images of the eight participants on each of the eight skin criteria revealed that no differences were detectable in the recaptured versions of the images of the participants' faces in their native digital forms solely with the human eye. There was an exception for only one participant, in whom a distinction between two image captures appeared to be subjectively visible with the human eye, but only for the criterion of red areas. As the subjective assessment revealed that no clinically relevant differences could be identified, a power analysis involving a test for significant differences between the recaptured images was discarded. As a consequence, the number of participants recruited for the study on the reproducibility of the system presented herein was deemed to be sufficient.

Conclusion

The precision of the Visia^® camera system was found to be satisfactory in this study. The Visia^® camera helped to visualise skin features beyond what is visible to the human eye. Thus, the Visia^® camera system provides new objective information on skin surface characteristics beyond what can be acquired through purely subjective assessments.

The Experience of 3D Total-Body Photography to Monitor Nevi: Results From an Australian General Population-Based Cohort Study

BACKGROUND

Digital 3D total-body photography of the skin surface is an emerging imaging modality that can facilitate the identification of new and changing nevi.

OBJECTIVE

We aimed to describe the experiences of study participants drawn from the general population who were provided 3D total-body photography and dermoscopy for the monitoring of nevi.

METHODS

A population-based prospective study of adults aged 20-70 years from South East Queensland, Australia was conducted. Participants underwent 3D total-body photography and dermoscopy every 6 months over a 3-year period. Participants were asked to provide closed and open-ended feedback on their 3D total-body photography and dermoscopy experience (eg, comfort, trust, intended future use, and willingness to pay) at the halfway study time point (18 months) and final study time point (36 months). We assessed changes in participants' reported experience of 3D total-body photography, and patient characteristics associated with patient experience at the end of the study (36 months) were analyzed.

RESULTS

A total of 149 participants completed the surveys at both the 18- and 36-month time points (median age 55, range 23-70 years; n=94, 63.1% were male). At the 18-month time point, most participants (n=103, 69.1%) stated they completely trusted 3D total-body imaging for the diagnosis and monitoring of their nevi, and this did not change at the 36-month (n=104, 69.8%) time point. The majority of participants reported that they were very comfortable or comfortable with the technology at both the 18- (n=138, 92.6%) and 36-month (n=140, 94%) time points, respectively; albeit, the number of participants reporting that they were very comfortable reduced significantly between the 18- and 36-month time points, from 71.1% (n=106) to 61.1% (n=91; P=.01). Almost all participants (n=140, 94%) would consider using this technology if it were to become commercially available, and this did not change during the two study time points. Half of the participants (n=74) cited barriers to participating in 3D total-body photography, including trust in the ability of this technology to detect and monitor suspicious lesions, digital privacy, cost, and travel requirements.

CONCLUSIONS

The majority of participants expressed positive attitudes toward 3D total-body photography for the monitoring of their moles. Half of the participants identified potential barriers to uptake.

Body mapping chart for estimation of percentage of body surface area in mesocephalic dogs

OBJECTIVE

To create a chart for estimating body surface area (BSA) for use in canine burn victims, similar to the human Rule of Nines.

DESIGN

Prospective study, from 2016 to 2017.

SETTING

University teaching hospital.

ANIMALS

Nine adult, medium-sized, mesocephalic dogs (5 females, 4 males).

INTERVENTIONS

Sedated dogs and fresh cadavers underwent full-body computed tomography (CT) scans. A 3-dimensional technique was used to calculate the surface area of specific body parts, as well as the surface area of the whole body. With the obtained measurements, a BSA chart was created.

MEASUREMENTS AND MAIN RESULTS

Estimates for percent of total BSA obtained with CT images were as follows: head and abdomen 14%, respectively, neck and each of the thoracic limbs 9%, thorax 18%, pelvic limbs 11% each, and pelvis including the tail 5%. The most considerable differences between dogs and people in respect to the Rule of Nines chart were noticed in the head, the pelvic limbs, as well as in the groin region in people as compared with the pelvic/tail area in dogs. The surface areas of the front legs and thorax were the only body parts that corresponded with that of human body surfaces.

CONCLUSIONS

A chart for estimating canine body surface was created. Given the diversity of dog breeds, sizes, and body conformation, our results cannot be generalized to all dogs. Studies of more diverse populations are warranted.

Application of Simulated Arms with Real-Time Pressure Monitor in Casting and Splinting by Physiological Sensors

In the real condition, the small sensor found it difficult to detect the position of the pressure sore because of casting displacement clinically. The large sensor will detect the incorrect pressure value due to wrinkles without close to arm. Hence, we developed a simulated arm with physiological sensors combined with an APP and a cloud storage system to detect skin pressure in real time when applying a short arm cast or splint. The participants can apply a short arm cast or splint on the simulative arm and the pressure in the cast or splint could be immediately displaced on the mobile application. The difference of pressure values from six pressure detection points of the simulated arm between the intern and the attending physician with 20-year working experience were 22.8%, −7.3%, 25.0%, 8.6%, 38.2%, 49.6%, respectively. It showed that the difference of pressure values in two farthest points, such as radius stab and ulnar styloid, was maximal. The pressures on the skin surface of the short arm cast were within acceptable range. Doctors would obtain reliable reference data and instantly understand the tightness of the swathed cast which would enable them to adjust it at any time to avoid complications.

Identifying patterns behind the changes in skin pores using 3-dimensional measurements and K-means clustering

Background

Skin pores are structural features of the skin, which tend to change as the skin ages. Since previous studies measured pores two‐dimensionally, precise measurements using three‐dimensional imaging were needed to comprehensively understand skin pores. This study aimed to determine the patterns behind the changes in skin pores during one's lifetime and to identify new characteristics of the pores in aged.

Materials and Methods

Skin surface profiles were measured three‐dimensionally from the cheeks of 101 Korean women from February to March 2020 to analyze the exact state of their pores. The researchers performed K‐means clustering to classify the skin pores, and topographical features of pores were analyzed as well. Statistical analyses were performed to verify the differences in the skin pore characteristics among clusters and the correlation between clusters and ages.

Results

Skin pores were classified into five groups based on size, density, and elongation. The skin conditions of the cluster groups were well correlated with aging, despite excluding age as a factor in pore classification. Adjacent skin pores tend to connect in the elderly.

Conclusion

Skin pores become larger and longer over time. Skin pores connect together in the elderly, which might be related to wrinkle formation. This phenomenon strongly suggests skin pores as a characteristic of aging skin and as a potential target for anti‐aging treatment.

Cutaneous microbiology of patients having primary shoulder arthroplasty

BACKGROUND

Shoulder periprosthetic infections are predominantly caused by bacteria residing in the skin of healthy individuals. Knowledge of the factors associated with the loads of the different cutaneous bacteria in individuals having shoulder arthroplasty may help identify patients at higher risk of periprosthetic infection and help guide preventive measures. For this reason, we tested the hypothesis that easy-to-obtain preoperative characteristics were significantly associated with the cutaneous microbiology and the loads of specific bacteria in shoulders having joint replacement.

METHODS

This study identified the microbiology of the unprepared epidermal skin surface and of the dermal edge freshly incised at surgery in 332 patients having primary shoulder arthroplasty. The load of bacteria in each sample was characterized as a value based on the laboratory report: 0 for "no growth"; 0.1 for "one colony only" or for "broth only"; and 1, 2, 3, and 4 for 1+, 2+, 3+, and 4+ growth, respectively. The relationships between preoperative patient characteristics and these semiquantitative results of the cutaneous cultures were analyzed.

RESULTS

Cultures of the unprepared epidermal skin surface showed positive results for a wide variety of organisms, including Cutibacterium in 72%, coagulase-negative Staphylococcus in 61%, and a spectrum of other organisms in 32%. By contrast, cultures of the freshly incised dermal edge showed a great preponderance of Cutibacterium (34%) in comparison to low levels of coagulase-negative Staphylococcus (8%) and other organisms (2%). An increased dermal load of Cutibacterium was significantly associated with male sex, younger patient age, American Society of Anesthesiologists class 1, use of testosterone supplements, prior shoulder surgery, and higher Cutibacterium loads on the unprepared skin surface.

CONCLUSIONS

Although the microbiology of the unprepared skin surface is diverse, the same is not true for the freshly incised dermis, where Cutibacterium is the predominant organism. Readily available preoperative patient characteristics are significantly associated with the load of Cutibacterium in the incised dermis. Preoperative cultures of the unprepared skin surface appear to be a new method for predicting the type and load of bacteria found in the freshly incised dermis at the time of surgery. Additional studies are needed to determine whether preoperative cultures of the unprepared epidermal skin surface can provide a method for identifying patients at increased risk of shoulder periprosthetic infections.

Lycopene presence in facial skin corneocytes and sebum and its association with circulating lycopene isomer profile: Effects of age and dietary supplementation

Lycopene is a dietary antioxidant known to prevent skin photodamage. This study aimed to examine age-dependent presence of this carotenoid on the surface of the facial skin and in the serum as well as to measure the same parameters during supplementation with lycopene. Serum samples and samples from facial skin surface were obtained from 60 young (under 25 years old) and 60 middle-aged (over 50 years old) volunteers. Similar samples were taken from 15 middle-aged subjects during 4-week supplementation with lycopene (7 mg/day). Serum lycopene levels and isomer profiles were analyzed by HPLC. Lycopene in desquamated corneocytes and the sebum from facial skin surface was determined using lycopene-specific fluorescent monoclonal antibodies. The results demonstrated that there was no age-related difference in serum lycopene levels, but a higher proportion of (all-E)-lycopene was detected in the "young" group (37.5% vs 26.2% in the "middle-aged" group; p < 0.0001). "Young" volunteers also had a higher lycopene level in both corneocytes (p = 0.0071) and the sebum (p = 0.0139) from the skin surface. Supplementation with lycopene resulted in a sharp increase of lycopene concentrations in both serum and skin surface samples. There was also a clear change in the pattern of lycopene isomers in the serum manifested by a significant increase in the proportion of (all-E)-lycopene (from 22.1% to 44.0% after supplementation, p < 0.0001). It can be concluded that dietary supplementation with lycopene results in its accumulation in the serum and skin. This process is accompanied by significant changes in the circulating lycopene isomer profile which becomes similar to that typical for young individuals.

Systemic and skin-targeting beneficial effects of lycopene-enriched ice cream: A pilot study

The health-promoting dietary antioxidant lycopene has limited natural bioavailability, but lycopene-rich functional foods can improve its bioavailability. We assessed a new lycopene-enriched ice cream for systemic antioxidant effects and influence on morphological characteristics of facial skin surface in healthy volunteers. In a randomized crossover study, we used 4-wk dietary interventions with either control or lycopene-enriched ice cream. Samples of serum and residual skin surface components (RSSC) from facial skin were taken before interventions, at 2 wk, and at intervention end. Lycopene concentration, conventional blood biochemistry, and oxidative stress biomarkers comprising inflammatory oxidative damage and low-density lipoprotein peroxidase proteins were assessed in the serum. Lycopene-associated immunofluorescence, lipid droplet size, corneocyte desquamation, and microbial presence were measured in the RSSC. The results show that lycopene concentrations in the serum and skin steadily increased during lycopene-enriched ice cream consumption. Whereas we found no intervention-dependent changes in conventional biochemical parameters, both inflammatory oxidative damage and low-density lipoprotein peroxidase protein values significantly decreased by the end of intervention with lycopene-enriched ice cream, but remained unchanged during control ice cream consumption. Control ice cream significantly increased corneocyte desquamation and bacterial presence in the RSSC. These adverse effects, which could potentially predispose consumers to acne development, were absent when volunteers consumed lycopene-enriched ice cream. We concluded that lycopene-enriched ice cream is a new functional food with clear antioxidant properties. In addition, enrichment with lycopene may alleviate proinflammatory action of ice cream at the level of facial skin, thus decreasing diet-associated acne development risk in young consumers.

Evaluation of Setup Errors at the Skin Surface Position for Whole Breast Radiotherapy of Breast Cancer Patients

We used image-processing software to analyze the setup errors at the skin surface position of breast cancer patients (n=66) who underwent post-operative whole breast irradiation at our hospital in 2014-2015. The sixty-six digital reconstructed radiographs (DRR) were created at the treatment planning for each patient. The lineacgraphies (n=377) were taken after the patients' setup during radiotherapy. The lineacgraphies and DRR were superimposed at the skin surface position for each patient with the image-processing software. We measured the deviations of the isocenters for the nipple-lung (X) direction and craniocaudal (Y) direction and the deviation of the rotation angle of the XY axes between the lineacgraphy and DRR on the superimposed images. The systematic error (μ, Σ) and random error (σ) were calculated from the X and Y deviations and rotation angle deviation. The μ of X, Y, and rotation angle were 0.01 mm, -1.2 mm, and 0.05°, respectively. The Σ of X, Y, and rotation angle were 1.8 mm, 1.5 mm, and 0.9°, respectively. The σ of X, Y, and rotation angle were 2.0 mm, 1.5 mm, and 1.0°, respectively. Our analyses thus revealed that evaluations using image-processing software at the skin surface position in routine breast radiotherapy result in sufficiently small setup errors.

[The influence of rhinoplasty on the physical and mechanical properties of the skin of the external nose]

This article was designed to report the results of the measurement of the surface acoustic wave velocity in the skin of the external nose following rhinoplastic surgery based on the analysis of the postoperative conditions in 374 patients. The patients were divided into two groups, one comprised of 286 (86.5%) patients who underwent the newly developed rehabilitative treatment and the group of comparison composed of 88 (23.5%) patients who received a different treatment during the postoperative period. The analysis has demonstrated the significant reduction in the velocity of the surface acoustic waves in the skin of the external nose of the patients of the main study group within 1 and 6 months after the surgical intervention. The change was especially well apparent at the sites with the relatively thicker skin underlain by the subcutaneous adipose tissue. This result can be regarded as giving evidence of the effectiveness of the proposed physiotherapeutic treatment that allowed to achieve the rapid decrease of postoperative oedema and prevent the subsequent excessive cicatrization.

Malathion dermal permeability in relation to dermal load: Assessment by physiologically based pharmacokinetic modeling of in vivo human data

Estimates of dermal permeability (K_p), obtained by fitting an updated human PBPK model for malathion to previously reported data on excreted urinary metabolites after 29 volunteers were dermally exposed to measured values of [¹⁴C]malathion dermal load (L), were used to examine the empirical relationship between K_p and L. The PBPK model was adapted from previously reported human biokinetic and PBPK models for malathion, fit to previously reported urinary excretion data after oral [¹⁴C]malathion intake by volunteers, and then augmented to incorporate a standard K_p approach to modeling dermal-uptake kinetics. Good to excellent PBPK-model fits were obtained to all of 29 sets of cumulative urinary metabolite-excretion data (ave. [±1 SD] R² = 0.953 [±0.064]). Contrary to the assumption that K_p and L are independent typically applied for dermally administered liquids or solutions, the 29 PBPK-based estimates of K_p obtained for malathion exhibit a strong positive association with the 2/3rds power of L (log-log Pearson correlation = 0.925, p = ∼0). Possible explanations of this observation involving physico-chemical characteristics and/or in vivo cutaneous effects of malathion are discussed. The PBPK model presented, and our observation that K_p estimates obtained by fitting this model to human experimental urinary-excretion data correlate well with L^2/3, allow more realistic assessments of absorbed and metabolized dose during or after a variety of scenarios involving actual or potential dermal or multi-route malathion exposures, including for pesticide workers or farmers who apply malathion to crops.

Relation between skin micro-topography, roughness, and skin age

BACKGROUND

The topography of the skin surface consists of lines, wrinkles, and scales. Primary and secondary lines form a network like structure that may be identified as polygons. Skin surface roughness measurements are widely applied in dermatological research and practice but the relation between roughness parameters and their anatomical equivalents are unclear. This study aimed to investigate whether the number of closed polygons (NCP) per measurement field can be used as a reliable parameter to measure skin surface topography. For this purpose, we analysed the relation between skin surface roughness parameters and NCP in different age groups.

METHODS

Images of the volar forearm skin of 38 subjects (14 children, 12 younger, and 12 older adults) were obtained with the VisioScan VC98. The NCP was counted by three independent researchers and selected roughness parameters were measured. Interrater reliability of counting the number of closed polygons and correlations between NCP, roughness parameters, and age were calculated.

RESULTS

The mean NCP/mm² in children was 3.1 (SD 1.1), in younger adults 1.0 (SD 0.7), and in older adults 1.0 (SD 0.9). The interrater reliability was 0.9. A negative correlation of NCP/mm² with age was observed, whereas measured roughness parameters were positively associated with age. NCP/mm² was weakly related to skin roughness.

CONCLUSION

The NCP/mm² is a reproducible parameter for characterizing the skin surface topography. It is proposed as an additional parameter in dermatological research and practice because it represents distinct aspects of the cutaneous profile not covered by established roughness parameters.

The Relationship between Exercise Intensity and Lactate Concentration on the Skin Surface

We examined the relationship between skin surface lactate concentration on working muscle and heart rate during continuous graded cycling exercise. Sixteen healthy male volunteers participated in this study. A plastic container with 100 μl 1% ethanol was put on the skin surface on the belly of rectus femoris muscle. The workloads were 300, 600, 900 and 1080 (or 990) kpm/min, and each stage was 5 min in duration. Sample collections were performed at rest, during exercise, and recovery. The lactate concentration during exercise significantly increased compared to the basal level (p<0.05 or p<0.001). Skin surface lactate concentration was found to correlate significantly with heart rate at the exercise intensity of 360 kpm/min (r=-0.52, p<0.05), 720 kpm/min (r=-0.74, p<0.01) and 900 kpm (r=-0.53, p<0.05). This study confirmed that 1) the increase in lactate concentration on the skin surface on working muscle is associated with increase in exercise intensity (heart rate), and 2) the skin surface lactate concentration on the working muscle can be used as a parameter of exercise intensity in each subject.