Evaluating change in bruise colorimetry and the effect of subject characteristics over time

A Versatile Nanovaccine Enhancement Strategy Based on Suction-Inspired Physical Therapy

Vaccine technology is effective in preventing and treating diseases, including cancers and viruses. The efficiency of vaccines can be improved by increasing the dosage and frequency of injections, but it would bring an extra burden to people. Therefore, it is necessary to develop vaccine-boosting techniques with negligible side effects. Herein, we reported a cupping-inspired noninvasive suction therapy that could enhance the efficacy of cancer/SARS-CoV-2 nanovaccines. Negative pressure caused mechanical immunogenic cell death and released endogenous adjuvants. This created a subcutaneous niche that would recruit and activate antigen-presenting cells. Based on this universal central mechanism, suction therapy was successfully applied in a variety of nanovaccine models, which include prophylactic/therapeutic tumor nanovaccine, photothermal therapy induced in situ tumor nanovaccine, and SARS-CoV-2 nanovaccine. As a well-established physical therapy method, suction therapy may usher in an era of noninvasive and high-safety auxiliary strategies when combined with vaccines.

Capturing the Diversity of Dermatology-What's in a Name?

As research related to skin of color (SOC) in dermatology continues to grow, it is increasingly important to precisely define terminology. The terms 'SOC', 'race', and 'ethnicity' are frequently used to analyze differences in dermatologic disease onset, severity, and outcomes. These terms are used interchangeably, are ill-defined across research studies, and frequently conflate biologic and socially constructed categories. SOC has been thought to represent differing degrees of pigment or melanin in the skin, however skin pigment is quite variable among races and ethnicities. Furthermore, certain individuals with less skin pigment may socially consider themselves to be SOC, while the inverse is also true. Fitzpatrick skin phototype classifications in SOC dermatology, while commonly used as an objective measure of diversity, also present with numerous limitations and inaccuracies. We seek to highlight strengths and weaknesses of the current terminology used in SOC dermatology and recommend a more holistic understanding of reported differences, including a framework reflective of upstream socioeconomic, environmental, and historical factors that may be most relevant to reported associations.

Pulsed Photothermal Radiometric Depth Profiling of Bruises by 532 nm and 1064 nm Lasers

Optical techniques are often inadequate in estimating bruise age since they are not sensitive to the depth of chromophores at the location of the bruise. To address this shortcoming, we used pulsed photothermal radiometry (PPTR) for depth profiling of bruises with two wavelengths, 532 nm (KTP laser) and 1064 nm (Nd:YAG laser). Six volunteers with eight bruises of exactly known and documented times of injury were enrolled in the study. A homogeneous part of the bruise was irradiated first with a 5 ms pulse at 532 nm and then with a 5 ms pulse at 1064 nm. The resulting transient surface temperature change was collected with a fast IR camera. The initial temperature-depth profiles were reconstructed by solving the ill-posed inverse problem using a custom reconstruction algorithm. The PPTR signals and reconstructed initial temperature profiles showed that the 532 nm wavelength probed the shallow skin layers revealing moderate changes during bruise development, while the 1064 nm wavelength provided additional information for severe bruises, in which swelling was present. Our two-wavelength approach has the potential for an improved estimation of the bruise age, especially if combined with modeling of bruise dynamics.

The frequently dismissed importance of properly sampling skin bruises

The correct interpretation of skin lesions is a crucial issue in forensic medicine. Many macroscopic and microscopic vital reaction markers and molecules have been studied in the past years in order to estimate the timing of injuries. However, literature lacks information regarding how to perform sampling to obtain a more reliable and accurate response. The present study investigates 25 bruises and analyses the different histological asset in different areas (central or marginal) and the different layers (epidermis, dermis, hypodermis and muscle) of the wound. All wounds were sampled in several areas and analysed under a 200× magnification optical microscope, simply counting the degree of haemorrhaging (i.e hematic infiltration) visible in each optical field (0 = 0%-5%; 1 = 6%-25%; 2 = 26%-50%; 3 = 51%-75%; 4 = 76%-100%). All the injuries presented some kind of infiltration in at least one area, nonetheless only 56% of the wounds were infiltrated in the entirety of the areas. Finally, in 28% the dermal layer did not show any trace of infiltration. Therefore, considering such results it seems that depth or area of sampling of a bruise may largely influence the evaluation of vitality and hence of age of a wound. Though this may seem intuitive, no studies have examined this issue in depth.

Noninvasive Monitoring of Dynamical Processes in Bruised Human Skin Using Diffuse Reflectance Spectroscopy and Pulsed Photothermal Radiometry

We have augmented a recently introduced method for noninvasive analysis of skin structure and composition and applied it to monitoring of dynamical processes in traumatic bruises. The approach combines diffuse reflectance spectroscopy in visible spectral range and pulsed photothermal radiometry. Data from both techniques are analyzed simultaneously using a numerical model of light and heat transport in a four-layer model of human skin. Compared to the earlier presented approach, the newly introduced elements include two additional chromophores (β-carotene and bilirubin), individually adjusted thickness of the papillary dermal layer, and analysis of the bruised site using baseline values assessed from intact skin in its vicinity. Analyses of traumatic bruises in three volunteers over a period of 16 days clearly indicate a gradual, yet substantial increase of the dermal blood content and reduction of its oxygenation level in the first days after injury. This is followed by the emergence of bilirubin and relaxation of all model parameters towards the values characteristic for healthy skin approximately two weeks after the injury. The assessed parameter values and time dependences are consistent with existing literature. Thus, the presented methodology offers a viable approach for objective characterization of the bruise healing process.

Quantifying the Degree of Bruise Visibility Observed Under White Light and an Alternate Light Source

BACKGROUND

Documentation of injuries associated with abuse and assault has pivotal impacts on clinical and legal outcomes. Before this study, no reliable and valid tools to consistently document the clinical visibility of bruises existed. The purpose of this study was to systematically evaluate reliability and validity of the Bruise Visibility Scale for documenting bruises visualized in normal (white) light and the Absorption Visibility Scale for documenting bruises visualized using an alternate light source (ALS).

METHODS

Bruises were induced using a paintball on the upper arms of 157 participants stratified into six skin color categories. Bruises were visualized 21 times over 4 weeks under white light and 10 ALS wavelength/goggle color combinations. Bruise size was measured using a metric ruler; bruise color was measured using a spectrophotometer. Interrater reliability was calculated using kappa and intraclass correlations coefficients. Construct validity was evaluated using generalized linear mixed modeling of associations between bruise size and color with both visibility scales.

RESULTS

Interrater agreement for bruise detection was over 90% for all but two ALS wavelength/goggle combinations. Kappa values indicated adequate interrater agreement under white light (κ = 0.76) and ALS (κ = 0.78). The visibility scale intraclass correlation coefficients were .91 for normal light and .93 for ALS. Statistical modeling showed greater bruise size was associated with higher visibility using either scale, and greater contrast in color or lightness was associated with higher Bruise Visibility Scale values.

IMPLICATIONS FOR PRACTICE

Both visibility scales showed satisfactory reliability and validity. Forensic nurses can use the scales to consistently document bruises.

Research Techniques Made Simple: Cutaneous Colorimetry: A Reliable Technique for Objective Skin Color Measurement

Skin color evaluation contributes to assessment of an individual's cutaneous phenotype. Skin color changes provide important clues to disease progression or treatment response. Skin color is also a predictor of skin cancer risk. Melanin pigment, blood flow, skin thickness, and photoaging contribute to skin color. Melanin, hemoglobin, bilirubin, and carotene are the primary chromophores of skin color. Their concentrations vary depending on the individual's phenotype, anatomic location, external insults of chemical irritants and UVR, and physiological changes. The evaluation and perception of skin color are often subjective. Objective quantification of skin color can be achieved with colorimetric devices such as tristimulus colorimeters. These devices compute the intensity of light reflected from skin and correlate with pigmentation and erythema. Cutaneous color and color changes can be quantified under color organization systems, such as the CIELAB color space, which is standardized by the Commission Internationale de l'Eclairage (CIE). The CIELAB expresses color's lightness, red/green intensity, and yellow/blue intensity, as L*, a*, and b* values, respectively. Additionally, skin color's full spectral characteristics and cutaneous physiology can be measured with spectrophotometers. This article outlines basic principles of the CIELAB color system and how to optimally use colorimetric devices as a skin research tool.

Detection of Inflicted Bruises by Alternate Light: Results of a Randomized Controlled Trial

Bruises are often difficult to detect on victims of violence, potentially impacting investigation and prosecution. The purpose of our randomized controlled trial was to measure the effectiveness of an alternate light source (ALS) within visible and long ultraviolet spectrums at improving bruise detection compared to white light over time. We also examined the effects of skin color, age, gender, localized fat, and injury mechanism on bruise detection. Participants included 157 healthy adults with balanced sampling across six skin color categories. Bruises were created under the controlled application of a paintball pellet and dropped weight to one upper and lower arm, respectively. Using a crossover design, both bruises were examined 21 times over 4 weeks. Ten different wavelength (350–535 nm) and filter (yellow, orange, red) combinations were used. Multilevel models were used to analyze 2903 examinations on both upper and lower arms. Results in multivariable models showed after controlling for other covariates 415 and 450 nm using a yellow filter had greater odds of detecting evidence of bruising than white light (Upper Arm: 415 nm: OR = 5.34, 95% CI: 4.35–6.56; 450 nm: OR = 4.08, 95% CI: 3.36–4.96). Under either light source, being female and having more localized fat had increased odds of detecting bruises created by the dropped weight (female: OR = 2.96, 95% CI: 2.37–3.70; fat: OR = 1.21, 95% CI: 1.09–1.34). Our results support ALS as an appropriate tool to enhance concurrent physical assessment of bruises in the presence of known history of injury. Future development and evaluation of clinical practice guidelines for ALS application are needed.

Determination of the age of bruises using a bilirubinometer

The dating of bruises can be of crucial interest in clinical forensic medicine, but the macroscopic or photographic evaluation of a bruise has not been regarded as reliable. Several methods have thus been regularly evaluated for this purpose, with reflectance spectrometry yielding promising results. The objective of this study is to evaluate the value of a bilirubinometer as a tool for dating bruises on living victims. A clinical follow-up was carried out on patients presenting a bruise with a known onset. Using a bilirubinometer, we obtained daily measurements of the bruise (bili-bruise) and of healthy skin (bili-skin). Potential confounding factors were collected: age, sex, body mass index, trauma mechanism and Fitzpatrick skin phototype. We followed 20 patients for a total of 88 measurements of bruises. Bili-skin values showed significant differences according to skin phototype. Differences between the bili-bruise and bili-skin values (Δ-bili) followed an increase phase, peaking between 3 and 5 days, and then there was a decrease phase. No significant Δ-bili value differences were observed based on the suspected confounding factors. Our results are in favour of a peak Δ-bili value generally at day 4 or 5 post-trauma. Notably, decreasing values were not observed before day 3. Decreasing Δ-bili values would then indicate a bruise resulting from an injury formed at least 3 days before the first measurement. Complementary work confirming such data would enable improvement of the performance of bruise dating in forensic medicine.

Optimising the measurement of bruises in children across conventional and cross polarized images using segmentation analysis techniques in Image J, Photoshop and circle diameter measurements

BACKGROUND

Bruising is a common abusive injury in children, and it is standard practice to image and measure them, yet there is no current standard for measuring bruise size consistently. We aim to identify the optimal method of measuring photographic images of bruises, including computerised measurement techniques.

METHODS

24 children aged <11 years (mean age of 6.9, range 2.5-10 years) with a bruise were recruited from the community. Demographics and bruise details were recorded. Each bruise was measured in vivo using a paper measuring tape. Standardised conventional and cross polarized digital images were obtained. The diameter of bruise images were measured by three computer aided measurement techniques: Image J (segmentation with Simple Interactive Object Extraction (maximum Feret diameter), 'Circular Selection Tool' (Circle diameter), & the Photoshop 'ruler' software (Photoshop diameter)). Inter and intra-observer effects were determined by two individuals repeating 11 electronic measurements, and relevant Intraclass Correlation Coefficient's (ICC's) were used to establish reliability. Spearman's rank correlation was used to compare in vivo with computerised measurements; a comparison of measurement techniques across imaging modalities was conducted using Kolmogorov-Smirnov tests. Significance was set at p < 0.05 for all tests.

RESULTS

Images were available for 38 bruises in vivo, with 48 bruises visible on cross polarized imaging and 46 on conventional imaging (some bruises interpreted as being single in vivo appeared to be multiple in digital images). Correlation coefficients were >0.5 for all techniques, with maximum Feret diameter and maximum Photoshop diameter on conventional images having the strongest correlation with in vivo measurements. There were significant differences between in vivo and computer-aided measurements, but none between different computer-aided measurement techniques. Overall, computer aided measurements appeared larger than in vivo. Inter- and intra-observer agreement was high for all maximum diameter measurements (ICC's > 0.7).

CONCLUSIONS

Whilst there are minimal differences between measurements of images obtained, the most consistent results were obtained when conventional images, segmented by Image J Software, were measured with a Feret diameter. This is therefore proposed as a standard for future research, and forensic practice, with the proviso that all computer aided measurements appear larger than in vivo.

Alternate Light Source Findings of Common Topical Products

BACKGROUND

One of the important roles of a forensic clinician is to perform examinations of patients who are victims and suspects of crime. Alternate light source (ALS) is a tool that can improve evidence collection and enhance visualization of injuries. The purpose of this study was to examine if commonly used topical products fluoresce or absorb when examined with an ALS. Second, we aimed to identify patient and examination variables that may impact findings.

METHODS

A convenience sample of 81 subjects was used. After the application of 14 over-the-counter products, researchers observed the participants' skin with an ALS under 18 combinations of wavelengths and colored filters.

RESULTS

Of the 14 products viewed (n = 1458 observations per product), six were found to fluoresce under alternate light in more than 40% of observations, five fluoresced in 1%-10% of observations, and three fluoresced less than 1% of the time. One product (a makeup product) absorbed ALS light consistently (81%), and a second (a sunscreen product) absorbed in 7%, whereas the remaining 12 products produced absorption findings in less than 1% of observations. In generalized mixed linear models, absorption findings were more commonly identified in participants with light or medium skin tones when compared with those with dark skin tones.

DISCUSSION

These results suggest that the presence of topical products may impact ALS findings. A thorough forensic clinical assessment should include a documented history, including assessment of potential sources of findings, to aid in interpretation.

Reliability of tristimulus colourimetry in the assessment of cutaneous bruise colour

BACKGROUND

Bruising is one of the most common types of injury clinicians observe among victims of violence and other trauma patients. However, research has shown commonly used qualitative description of cutaneous bruise colour via the naked eye is subjective and unreliable. No published work has formally evaluated the reliability of tristimulus colourimetry as an alternative for assessing bruise colour, despite its clinical and research applications in accurately assessing skin colour. The purpose of this study was to systematically evaluate the test-retest and inter-observer reliability of tristimulus colourimetry in the assessment of cutaneous bruise colour.

METHODS

Two researchers obtained repeated tristimulus colourimetry measures of cutaneous bruises with participants of diverse skin colour. Measures were obtained using the Minolta CR-400 Chomameter. Commission Internationale d'Eclairage (CIE) L*a*b* colour space was used. Data was analysed using intraclass correlation coefficients (ICC), Cronbach's alpha, and minimal detectable change (MDC) on all three L*a*b* values.

RESULTS

The colorimeter demonstrated excellent test-retest or intra-rater reliability (L* ICC=0.999; a* ICC=0.973; b* ICC=0.892) and inter-rater reliability (L* ICC=0.997; a* ICC=0.976; b* ICC=0.982).

CONCLUSIONS

With consistent placement, the tristimulus colourimetry is reliable for the objective assessment and documentation of cutaneous bruise colour for purposes of clinical practice and research. Recommendations for use in practice/research are provided.