Skin Color Research Articles

Genome-Wide Identification and Expression Analysis of Fifteen Gene Families Involved in Anthocyanin Synthesis in Pear

Anthocyanins play a crucial role in imparting red coloration to pear fruits. However, the specific number and expression patterns of each member within the anthocyanin biosynthesis-related gene families in pears require systematic exploration. In this study, based on the pear genome we identified 15 gene families involved in the anthocyanin biosynthesis pathway using the BLASTP and Hidden Markov Model search methods, comprising a total of 94 enzyme genes. Through phylogenetic analysis, conserved domains, motif, and gene structure analysis, these gene families were further categorized into eight distinct lineages. Subsequent collinearity analysis revealed that the expansion of anthocyanin synthesis-related gene families primarily originated from segmental duplications. Analysis of cis-element in the promoter regions of genes related to anthocyanin synthesis unveiled the presence of light-responsive elements and various hormone-responsive elements. This suggests that changes in light stimulation and hormone levels may influence anthocyanin synthesis. RNA-Seq and qRT-PCR analyses indicated differential expression of anthocyanin biosynthesis-related genes between the peel and flesh tissues. During the accumulation of anthocyanins in red-fleshed pears, upstream genes in the anthocyanin biosynthesis pathway such as PbrPAL2, PbrC4H2, PbrC4H3, Pbr4CL2, Pbr4CL17, PbrF3H5, and PbrF3H6 exhibited high expression levels, likely contributing significantly to the red coloration of pear flesh. In summary, we have identified the number of gene family members involved in pear anthocyanin biosynthesis and analyzed the expression patterns of the genes related to pear anthocyanin biosynthesis. These findings provide a solid foundation for further research on the regulatory mechanisms underlying pear anthocyanin biosynthesis and the breeding of red pear varieties.

Enhancing postharvest quality and extending storage life of Booth 7 avocado (Persea americana Mill.) fruit through sodium nitroprusside (SNP) application during low-temperature storage

Postharvest quality plays a crucial role in marketability, consumer acceptability, and shelf life of avocados. This study investigates the efficacy of nitric oxide (NO) on postharvest physiology and quality of Booth 7 avocados treated with different concentrations of sodium nitroprusside (SNP) - a nitric oxide-releasing compound. Booth 7 avocados were immersed in SNP solutions (0.5 mM, 1.0 mM, and 1.5 mM), while the control fruit was immersed in distilled water for 15 min. After treatment, the fruit was stored at a temperature (T) of 8 ± 1 °C and relative humidity (RH) of 90 ± 5% for 35 days, during which the control fruit exhibited complete deterioration. The results revealed that Booth 7 avocados treated with 1.5 mM SNP concentration exhibited delayed quality changes during storage, reduced ethylene production and respiration rate, reduced alterations in soluble solids and acid content of the fruit flesh, as well as delayed changes in flesh and peel color. Additionally, the activity of total phenolic compounds (TPC), polygalacturonase (PG), and polyphenol oxidase (PPO) enzymes increased significantly, while the activity of the pectin methyl esterase (PME) enzyme was reduced. In conclusion, SNP treatment improved the quality and can be utilized as a potential postharvest preservative for Booth 7 avocados. For producers and distributors, the use of SNP in avocado postharvest management offers the potential to extend shelf life without compromising fruit quality.

The Efficacy of a Cosmetic Preparation Containing Sheep Colostrum on Mature Skin: A Randomized Placebo-Controlled Double-Blind Study

Colostrum, the first milk produced by mammals, is rich in various bioactive components that provide numerous health benefits to newborns, such as growth factors, hormones, immunoglobulins, cytokines, and enzymes. Topical application of bovine or equine colostrum has been found to improve regeneration, accelerate cutaneous wound healing, and have moisturizing, protective, and anti-aging properties. The aim of this study was to examine the effect of a cosmetic preparation containing sheep colostrum on skin with signs of aging in mature women. Fifty-two women, aged 40–70, were randomized into two groups to receive either colostrum or placebo cream. The participants applied the cream for eight weeks. Skin hydration, TEWL, sebum, erythema, and tone were measured using a standardized Courage + Khazaka electronic GmbH Multi Probe Adapter; skin elasticity was measured with a cutometer, and images were taken by FotoMedicus. The treatment increased skin moisture, reduced TEWL, and improved skin firmness. These findings were confirmed by the subjective survey. The participants reported, inter alia, improved skin softness and less redness and hypersensitivity. Sheep colostrum cream was more effective at improving skin conditions than placebo cream. Colostrum creams can improve certain aspects of skin quality, especially the hydrolipid barrier, and overall rejuvenation.

An experimental study on the application of “blue” (λ = 450 nm) laser light to remove pigmented skin formations

Objective. Pigment benign skin formations, including pigment spots, nevi and congenital giant pigment nevi (CGPN) are pathological skin formations located in its various layers, consisting of a cluster of melanocytes – cells containing the pigment melanin. CGPN are a special psychological and medical problem associated with extensive unaesthetic changes in the skin and with changed appearance of the patient Currently, there are numerous methods for treating pigmented skin formations, including CGPN. But all them are often ineffective and lead to unsatisfactory clinical and aesthetic results, while the incidence of complications sometimes reaches 41 % of cases in the form of scarring and recurrences. In this regard, the problem of effective and correct treatment of them continues to be relevant and requires further research in this direction.Purpose. To experimentally substantiate the effectiveness of application of laser light with wavelength λ = 450 nm for improving outcomes of treatment of pigmented skin formations, including CGPN, in children.Materials and methods. In the present trial, the researchers used laser light of “blue” spectral range (λ = 450 nm) with the absorption peak close to melanin, hemoglobin and oxyhemoglobin. Such light is generated by diode laser «Lasermed 10-03», developed for medical purposes by Russian Engineering Club LLC, Tula, Russian Federation. An experimental biomedical study was performed in vitro on cooled samples of mini-pig liver and muscles and in vivo on the pigmented skin of a live laboratory rat with the assessment of morphometric parameters and dynamics of the regenerative wound process at the irradiated zones.Results. The results of the performed experimental study promoted the development of optimal modes of “blue” (λ = 450 nm) laser irradiation for the precise removal of various pigmented skin formations.Conclusion. Laser light with wavelength 450 nm is a promising technique for the effective treatment of pigmented skin formations, among others CGPN, in pediatric patients as well

Validation of a Novel Noninvasive Technology to Estimate Blood Oxygen Saturation Using Green Light: Observational Study

Background Pulse oximeters work within the red-infrared wavelengths. Therefore, these oximeters produce erratic results in dark-skinned subjects and in subjects with cold extremities. Pulse oximetry is routinely performed in patients with fever; however, an elevation in body temperature decreases the affinity of hemoglobin for oxygen, causing a drop in oxygen saturation or oxyhemoglobin concentrations. Objective We aimed to determine whether our new investigational device, the Shani device or SH1 (US Patent 11191460), detects a drop in oxygen saturation or a decrease in oxyhemoglobin concentrations. Methods An observational study (phase 1) was performed in two separate groups to validate measurements of hemoglobin and oxygen concentrations, including 39 participants recruited among current university students and staff aged 20-40 years. All volunteers completed baseline readings using the SH1 device and the commercially available Food and Drug Administration–approved pulse oximeter Masimo. SH1 uses two light-emitting diodes in which the emitted wavelengths match with absorption peaks of oxyhemoglobin (hemoglobin combined with oxygen) and deoxyhemoglobin (hemoglobin without oxygen or reduced hemoglobin). Total hemoglobin was calculated as the sum of oxyhemoglobin and deoxyhemoglobin. Subsequently, 16 subjects completed the “heat jacket study” and the others completed the “blood donation study.” Masimo was consistently used on the finger for comparison. The melanin level was accounted for using the von Luschan skin color scale (VLS) and a specifically designed algorithm. We here focus on the results of the heat jacket study, in which the subject wore a double-layered heated jacket and pair of trousers including a network of polythene tubules along with an inlet and outlet. Warm water was circulated to increase the body temperature by 0.5-0.8 °C above the baseline body temperature. We expected a slight drop in oxyhemoglobin concentrations in the heating phase at the tissue level. Results The mean age of the participants was 24.1 (SD 0.8) years. The skin tone varied from 12 to 36 on the VLS, representing a uniform distribution with one-third of the participants having fair skin, brown skin, and dark skin, respectively. Using a specific algorithm and software, the reflection ratio for oxyhemoglobin was displayed on the screen of the device along with direct hemoglobin values. The SH1 device picked up more minor changes in oxyhemoglobin levels after a change in body temperature compared to the pulse oximeter, with a maximum drop in oxyhemoglobin concentration detected of 6.5% and 2.54%, respectively. Conclusions Our new investigational device SH1 measures oxygen saturation at the tissue level by reflectance spectroscopy using green wavelengths. This device fared well regardless of skin color. This device can thus eliminate racial disparity in these key biomarker assessments. Moreover, since the light is shone on the wrist, SH1 can be readily miniaturized into a wearable device.

Studying anthocyanins in the skin and flesh of the tubers of some potato hybrids (<i>Solanum tuberosum</i> L.)

Relevance. Today special attention is paid to potato anthocyanins as components of functional food. Increasing interest is generated by research on the use of anthocyanins for the benefit of animals and people in addition to their significant role in the life of plants. The research goal was to identify the quantitative and qualitative composition of anthocyanins in the tubers of valuable potato hybrids of Primorsky selection. Five promising potato hybrids (Solanum tuberosum L.) belonging to different groups of maturity and involved in the comparative variety testing by FSBSI “FSC of Agricultural Biotechnology named after A. K. Chaiki” were used as the research object. The research was carried out under the conditions of field and laboratory experiments in Primorsky kray, Russia, in 2018-2023. The anthocyanins were divided by the method of high-performance liquid chromatography. The anthocyanins were identified by the method of second-order mass spectrometry. Results. The research evaluated the potato hybrids for the content of anthocyanins in the tissues of the tubers – skin and flesh. The following specimens were determined to have a high content of anthocyanins both in the skin and flesh: Pri-15-12-14 (petunidin-3-arabinoside: 310.0 and 91.1 mg/kg; cyanidin-3-glucoside: 149.8 and 39.8 mg/kg) and Pri-14-52-2 (petunidin-3-arabinoside: 360.0 and 143.0 mg/kg; cyanidin-3-glucoside: 80.4 and 81.2 mg/kg). The selected specimens were characterized by purple and blue-purple skin. Genotypes Pri-14-52-2 and Pri-15-12-14 had tuber flesh with purple pigmentation. Hybrids Pri-15-12-14 and Pri-14-52-2 had the highest total content of anthocyanins in the flesh – 130.9 and 224.2 mg/kg, respectively. The conducted research identified eight different anthocyanins in the tubers of the studied potato specimens: delphinidin-3-glucoside, delphinidin-3-ramnosil-5-glucoside, petunidin-3-glucoside, malvidin-3-glucoside, cyanidin-3-glucoside, cyanidin-3-ramnosil-5-glucoside, pelargonidin-3-glucoside, and petunidin-3-arabinoside. The tubers with pink and red skin were determined to contain pelargonidin-3-glucoside. Petunidin-3-glucoside and cyanidin-3-glucoside colored tuber skin purple. The selected group of specimens might be recommended for use as functional food and in goal-oriented breeding.

Abscisic acid activates transcription factor module MdABI5-MdMYBS1 during carotenoid-derived apple fruit coloration.

Carotenoids are major pigments contributing to fruit coloration. We previously reported that the apple (Malus domestica Borkh.) mutant fruits of 'Beni Shogun' and 'Yanfu 3' show a marked difference in fruit coloration. However, the regulatory mechanism underlying this phenomenon remains unclear. In this study, we determined that carotenoid is the main factor influencing fruit flesh color. We identified an R1-type MYB transcription factor, MdMYBS1, which was found to be highly associated with carotenoids and abscisic acid (ABA) contents of apple fruits. Overexpression of MdMYBS1 promoted, and silencing of MdMYBS1 repressed, β-branch carotenoids synthesis and ABA accumulation. MdMYBS1 regulates carotenoid biosynthesis by directly activating the major carotenoid biosynthetic genes encoding phytoene synthase (MdPSY2-1) and lycopene β-cyclase (MdLCYb). 9-cis-epoxycarotenoid dioxygenase 1 (MdNCED1) contributes to ABA biosynthesis, and MdMYBS1 enhances endogenous ABA accumulation by activating the MdNCED1 promoter. In addition, the basic leucine zipper domain transcription factor ABSCISIC ACID-INSENSITIVE5 (MdABI5) was identified as an upstream activator of MdMYBS1, which promotes carotenoid and ABA accumulation. Furthermore, ABA promotes carotenoid biosynthesis and enhances MdMYBS1 and MdABI5 promoter activities. Our findings demonstrate that the MdABI5-MdMYBS1 cascade activated by ABA regulates carotenoid-derived fruit coloration and ABA accumulation in apple, providing avenues in breeding and planting for improvement of fruit coloration and quality.

Morphological structure and ethnic background of the Sudanese Shagia tribe (East Africa)

North Sudan, especially the 4th Nile Cataract region, is home to one of the world’s most isolated human populations. This study aimed to clarify the ethnic background of the Shagia based on anthropological analyses. This study provides a morphological and ethnographic characterisation of the previously unstudied Shagia tribe. Head and body measurements were conducted among 64 adults from three villages. There were observable but relatively small admixture proportions of non-African population genes (light skin colour, narrow noses and masculine proportions) in their morphological build. The Shagia’s uniqueness may have been the result of severe genetic drift episodes resulting from founding events, such as long-term isolation and traditionally small population size. It is useful to trace the ethnic history of Africans and, specifically, for the tribal members of Shagia so that they may better understand and learn about their history. This study shows that the Shagia tribe was displaced from their territory due to the construction of the Merowe Dam. Thus, the results of this research fulfil the assumptions of urgent anthropology, as it contributes to the protection of the heritage of the 4th Nile Cataract region: an area of historical value to the study of the evolution of contemporary civilisation.

To Study “The Impact Of Skin Color Satisfaction On Self Esteem And Anxiety Among Young Adults”

This study investigates the connection between young individuals (18–25 years) anxiety levels, self-esteem, and skin color satisfaction. Utilizing a quantitative survey technique and drawing from previous research, the study attempts to define the relationship between skin color satisfaction and psychological well-being in this population. Standardized tests measuring anxiety, self-esteem, and skin color satisfaction were completed by the participants. To investigate the relationships between these factors, statistical studies were performed. The results showed that among young individuals, there were substantial relationships between anxiety levels, self-esteem, and skin color satisfaction. More specifically, there was negative relationship between anxiety and skin color satisfaction. These findings imply that early in adulthood, judgments of one's own skin tone are quite important in determining psychological consequences. The significance of these findings explored in relation to encouraging young adults to have good body images and mental health, and future directions for study and intervention are indicated.

Punica granatum L. (Pomegranate) Extracts and Their Effects on Healthy and Diseased Skin.

The aim of this review is to provide a summary of the botany, phytochemistry and dermatological effects of Punica granatum (PG), with special emphasis on therapeutic mechanisms in various skin conditions. PG peel contains the highest levels of chemical compounds. Due to the high abundance of polyphenolic compounds, including phenolic acids, anthocyanins and flavonoids, exhibiting strong antioxidant properties, PG peel possesses significant health-promoting effects. Up until now, different parts of PG in the form of various extracts, fixed seed oil or individual active compounds have been investigated for various effects on skin conditions in in vitro and in vivo studies, such as antioxidant, anti-inflammatory, antimicrobial, chemoprotective and antiaging effects, as well as positive effects on striae distensae, skin repair mechanisms, erythema, pigmentation and psoriasis. Therefore, formulations containing PG active compounds have been used for skincare of diseased and healthy skin. Only a few effects have been confirmed on human subjects. Based on encouraging results obtained in in vitro and animal studies about the numerous substantial dermatological effects of PG active compounds, future perspectives should incorporate more in vivo investigations in human volunteers. This approach can aid in identifying the optimal concentrations and formulations that would be most efficacious in addressing specific skin conditions.

The representation of skin of colour in the Australasian Journal of Dermatology.

The representation of skin of colour in the Australasian Journal of Dermatology.

Cutaneous manifestations of systemic diseases in Afro‐Caribbean skin

AbstractThere is a need for training dermatologists in skin of colour's common and less common dermatoses due to the increasing diversity of the world population. The aim of this review is to highlight on cutaneous manifestations of systemic diseases in Afro‐Caribbean people, especially sarcoidosis, dermatomyositis, systemic sclerosis, systemic lupus.

Sun protection in outdoor workers - Development and validation of standardized questionnaires for behavior and knowledge.

Outdoor workers are at increased risk of developing non-melanoma skin cancer. We aimed to address the lack of validated German-language measurement instruments for outdoor workers' sun safety behavior and knowledge by compiling and validating two questionnaires. By expert consensus, items for the assessment of protective behavior (OccuSun) were compiled based on existing instruments. For knowledge, a translation of the Skin Cancer and Sun Knowledge (SCSK) scale was selected. After a pre-test, a validation study including 68 outdoor workers (62% female) was conducted in 2020. The retest reliability was r = 0.93 (95% confidence interval: 0.86-0.96) for the protection score and rs = 0.78 (0.67-0.86) for the knowledge score. Protective behaviors were correlated with respective diary data (0.38≤rs≤0.74, p<0.001) and skin pigmentation changes (-0.23 ≥ rs ≥ -0.42, 0.007≤p≤0.165) but not with self-reported sunburn frequency (0.21 ≥ rs ≥ -0.04). Among German outdoor workers, two questionnaires for the assessment of sun protection behavior (OccuSun) and knowledge (SCSK) demonstrated good reliability. The OccuSun had generally good validity. Both instruments are fit for subsequent validation to determine their sensitivity to change.

Color Face Image Generation with Improved Generative Adversarial Networks

This paper focuses on the development of an improved Generative Adversarial Network (GAN) specifically designed for generating color portraits from sketches. The construction of the system involves using a GPU (Graphics Processing Unit) computing host as the primary unit for model training. The tasks that require high-performance calculations are handed over to the GPU host, while the user host only needs to perform simple image processing and use the model trained by the GPU host to generate images. This arrangement reduces the computer specification requirements for the user. This paper will conduct a comparative analysis of various types of generative networks which will serve as a reference point for the development of the proposed Generative Adversarial Network. The application part of the paper focuses on the practical implementation and utilization of the developed Generative Adversarial Network for the generation of multi-skin tone portraits. By constructing a face dataset specifically designed to incorporate information about ethnicity and skin color, this approach can overcome a limitation associated with traditional generation networks, which typically generate only a single skin color.

Quality-Diversity Generative Sampling for Learning with Synthetic Data

Generative models can serve as surrogates for some real data sources by creating synthetic training datasets, but in doing so they may transfer biases to downstream tasks. We focus on protecting quality and diversity when generating synthetic training datasets. We propose quality-diversity generative sampling (QDGS), a framework for sampling data uniformly across a user-defined measure space, despite the data coming from a biased generator. QDGS is a model-agnostic framework that uses prompt guidance to optimize a quality objective across measures of diversity for synthetically generated data, without fine-tuning the generative model. Using balanced synthetic datasets generated by QDGS, we first debias classifiers trained on color-biased shape datasets as a proof-of-concept. By applying QDGS to facial data synthesis, we prompt for desired semantic concepts, such as skin tone and age, to create an intersectional dataset with a combined blend of visual features. Leveraging this balanced data for training classifiers improves fairness while maintaining accuracy on facial recognition benchmarks. Code available at: https://github.com/Cylumn/qd-generative-sampling.

Abstract 7168: PBI-410 (GQ1010), A novel Trop-2-targeted ADC demonstrates a favorable safety and toxicokinetic profile in multiple preclinical assessments

Abstract Introduction: Trop-2-targeting ADCs (Trop-2 ADC) have demonstrated notable clinical efficacy; however, safety concerns necessitate frequent dose adjustments or discontinuations. PBI-410 (GQ1010) is a next-generation TROP-2 ADC developed using GeneQuantum's Ligase-Dependent Conjugation (iLDC) technology, that integrates a highly stable linker and a novel camptothecin analogue payload, TopoIx. This study included comprehensive preclinical evaluations that demonstrated a favorable safety and TK profile and potential for broader therapeutic margin versus other Trop-2 ADCs approved or in development. Methods: TopoIx underwent extensive Good Laboratory Practice toxicity assessments in Sprague-Dawley (SD) rats (payload alone) and as part of the intact ADC in Non-Human Primates. Rats were administered repeated intravenous infusions of 0.5, 1.25, and 2.5 mg/kg of H0011 once a week over 5 doses. The potential toxicity profile of PBI-410 was evaluated in cynomolgus monkeys via repeated intravenous infusions of 10, 30, and 60 mg/kg doses every 3 weeks for 3 doses, followed by a six-week recovery phase. Results: TopoIx administration in SD rats exhibited good tolerance, with slight reductions in body weight gain and food consumption. Microscopic tissue changes resolved post-drug withdrawal, except for persistent findings in the sciatic nerve. Repeated doses of PBI-410 in cynomolgus monkeys were well-tolerated, primarily manifesting as skin pigmentation and associated microscopic alterations in specific tissues, such as eyes, esophagus, thymus, and lymph nodes typical for topoisomerase inhibitors. Importantly, these changes were reversible upon drug cessation. The HNSTD/NOAEL for PBI-410 was determined to be 60 mg/kg. This corresponds to mean Cmax of 1760 µg/mL and AUCinf of 235000 µg*hr/mL for ADC and for TopoIx mean Cmax of 16.4 ng/mL and AUCinf of 2610 ng*hr/mL. The lower exposure of TopoIx suggests minimum payload shedding in the systemic circulation. Notably, PBI-410 demonstrated a significantly enhanced safety profile compared to other Topo1-based Trop-2 ADCs, including an absence of hematopoietic and intestinal toxicities, and no pulmonary toxicity or interstitial lung disease (ILD) observed. Conclusion: PBI-410 demonstrated a favorable and differentiated nonclinical safety profile and favorable TK relative to those reported to date for other Trop-2 ADCs in development. This profile, in addition to the potent anti-tumor response and synergistic activity in combination with anti-PD1 reported previously, position PBI-410 as a best-in-class potential Trop-2 ADC and partner of choice for anti-PD1 combination therapy. Additionally, TopoIx has displayed excellent properties among the TOP1 inhibitors, making it suitable for a broader therapeutic application based on exceptional potency while maintaining a favorable safety profile. Citation Format: Yajun Sun, Vijayapal Reddy, Palaniappan Kulanthaivel, Yanwen Feng, Jie Zhao, Zhiyan Chi, Junhao Wang, Lili Shi, Gang Qin, Paul H. Song. PBI-410 (GQ1010), A novel Trop-2-targeted ADC demonstrates a favorable safety and toxicokinetic profile in multiple preclinical assessments [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 7168.

Quantitative Digital Image Assessment of Skin of Color Representation in a Medical School Dermatology Course.

This article utilizes a novel objective method to analyze the representation of various skin tones in a medical school dermatology course. By employing quantitative methods, the research aims to improve skin of color representation in medical curricula and highlight the importance of inclusive education for better patient care.

A Case Report of the First CEA Transplant in an HIV-Positive Burn Patient in South Africa Using a Novel Composite Culture Technique

AbstractResource-limited burn centers are usually devoid of cultured epithelial autografts (CEA) owing largely to prohibitive costs. A modified CEA technique at our burn center incorporated cost-effective, routinely-used dressings with favorable outcomes. One unknown concern was the immunosuppressive effect that extensive burns and potentially human immunodeficiency virus (HIV) infection may have on graft take. This case study reports on the graft take outcomes of the first CEA transplanted in an HIV-positive patient with extensive burns in South Africa, using this technique. Graft take was determined after 21 days at 80% and a long-term follow-up of 8 years indicated good pigmentation return and skin pliability. Delayed diagnosis of pyoderma gangrenosum caused partial graft loss; however, successful regrafting occurred after pyoderma gangrenosum treatment and eradication. The case was considered clinically successful. HIV may not directly affect graft take, but may result in immunosuppressive conditions that delay graft take success.

Highly Sensitive Detection of Melanin in Melanomas Using Multi-harmonic Low Frequency EPR.

Low frequency EPR can noninvasively detect endogenous free radical melanin in melanocytic skin lesions and could potentially discriminate between benign atypical nevi and malignant melanoma lesions. We recently succeeded in demonstrating the ability of clinical EPR to noninvasively detect the endogenous melanin free radical in skin lesions of patients. However, the signal-to-noise ratio (SNR) was extremely low warranting further research to boost the sensitivity of detection. In the present study, we assessed the performance of a clinical EPR system with the capability to perform multi-harmonic (MH) analysis for the detection of melanin. The sensitivity of MH-EPR was compared with a classical continuous wave (CW)-EPR (1st harmonic) detection in vitro in melanin phantoms, in vivo in melanoma models with cells implanted in the skin, in lymph nodes and having colonized the lungs, and finally on phantoms placed at the surface of human skin. In vitro, we observed an increase in SNR by a factor of 10 in flat melanin phantoms when using MH analysis compared to CW combined with an increase in modulation amplitude. In B16 melanomas having grown in the skin of hairless mice, we observed a boost in sensitivity in vivo similar to that observed in vitro with the capability to detect melanoma cells at an earlier stage of development. MH-EPR was also able to detect non-invasively the melanin signal coming from melanoma cells present in lymph nodes as well as in lungs. We also observed a boost of sensitivity using phantoms of melanin placed at the surface of human skin. Overall, our results are paving the way for new clinical trials that will use MH clinical EPR for the characterization of pigmented skin lesions.

Genomic insights into shank and eggshell color in Italian local chickens

Eggshell and shank color in poultry is an intriguing topic of research due to the roles in selection, breed recognition, and environmental adaptation. This study delves into the genomics foundations of shank and eggshell pigmentation in Italian local chickens through genome-wide association studies analysis to uncover the mechanisms governing these phenotypes. To this purpose, 483 animals from 20 local breeds (n = 466) and 2 commercial lines (n = 17) were considered and evaluated for shank and eggshell color. All animals were genotyped using the Affymetrix Axiom 600 K Chicken Genotyping Array. As regards shank color, the most interesting locus was detected on chromosome Z, close to the TYRP1 gene, known to play a key role in avian pigmentation. Additionally, several novel loci and genes associated with shank pigmentation, skin pigmentation, UV protection, and melanocyte regulation were identified (e.g., MTAP, CDKN2A, CDKN2B). In eggshell, fewer significant loci were identified, including SLC7A11 and MITF on chromosomes 4 and 12, respectively, associated with melanocyte processes and pigment synthesis. This comprehensive study shed light on the genetic architecture underlying shank and eggshell color in Italian native chicken breeds, contributing to a better understanding of this phenomenon which plays a role in breed identification and conservation, and has ecological and economic implications.