Pigment Deposition Research Articles

Neovascularisation of the lens capsule: a unique finding

A 62 year-old man consulted for progressive loss of vision in both eye. His past ophthalmological history was unremarkable and he denied any known systemic condition. On examination, his best corrected visual acuity was light perception oulus uterque (OU). Papillary reaction to light was sluggish oculus sinister (OS) and normal OU. Ocular motility was full OU with normal intra-ocular pressure. Slit-lamp examination showed bilateral white mature cataract with low pharmacological dilation. High magnification under dilation revealed a vascular network composed of fine vessels located nasally adjacent to the papillary border on the anterior capsule of the lens associated with pigment deposits and loss of the papillary frill (A). There was no evidence of neovascularisation of the iris (NVI) or the angle neurovascular assessment (NVA). Ocular ultrasound was negative for vitreous hemorrhage or retinal detachment. Ancilliary testing for diagnosis of common aetiologies of anterior segment neovascularisation was carried out and revealed type 2 diabetes. The patient was referred for evaluation and control of his newly diagnosed diabetes. After six months, we performed an uneventful cataract surgery by phacoemulsification. Fundus fluorescein angiography (FFA) showed posterior segment ischemia with neovascularisation elsewere (B). Neovascularisation spared the iris and the angle. Thus, nerve conduction velocity (NVC) was the solely sign of anterior segment neovascularisation.

Evaluation of hair structural abnormalities in children with different neurological diseases

Hair microscopy is a fast and effortless diagnostic method for many diseases affecting hair in daily practice. Many diseases can present with hair shaft disorders in pediatric neurology practice. Children with pathological hair findings were included in our study. Microscopic evaluation of the hair was performed under light microscopy. The clinical findings, pathological hair shaft findings, laboratory tests, and final diagnosis of the patients were evaluated. In our study, 16 patients with rare pathological hair findings were identified. Of these 16 patients, nine were diagnosed with giant axonal neuropathy, three with Griscelli syndrome, two with Menkes disease, and two with autosomal recessive woolly hair disease. In hair inspection, curly and tangled hair in patients with giant axonal neuropathy; silvery blond hair in patients with Griscelli syndrome; sparse, coarse, and light-colored hair in patients with Menkes disease; and hypotrichosis in patients with autosomal recessive woolly hair were remarkable findings. Dystrophic hair was detected in most of the patients on light microscopy. In addition, signs of trichorrhexis nodosa, tricoptylosis, and pili torti were found. In particular, pigment deposition in the hair shaft of two patients diagnosed with Griscelli syndrome and pili torti findings in two patients with Menkes disease were the most important findings suggestingthe diagnosis. Detection of hair findings in the physical examination and performing light microscopic evaluation facilitates the diagnosis of rare diseases accompanied by hair findings. A hair examination should be performed as a part of physical and neurological examinationson eachpatient regardless of thecomplaint.

Role of Dermoscopy in Distinguishing Tinea Nigra from Acral Nevus

Dermoscopy is a practical, non-invasive tool that can be used to distinguish tinea nigra from other lesions that appear macroscopically similar, including acral nevus. Under dermoscopy, tinea nigra presents with a pattern of spiculated gray-brown pigment deposition, whereas acral nevus most often presents as brown pigment deposition in a parallel furrow pattern.

The Co-Occurrence of Anthracosis with Interstitial Lung Disease.

Anthracosis is defined as deposition of black pigments in the bronchial mucosa or lung parenchyma. The aim of this study was to investigate the clinical features of patients with coexisting anthracosis and interstitial lung diseases (ILDs). A total of 335 ILDs patients who underwent bronchoscopy at the affiliated hospital of Qingdao University were included in our study. We enrolled 71 patients who diagnosed with anthracosis by bronchoscopy. The clinical presentations, radiographic features, and bronchoscopic findings of the patients were reviewed. Compared with the non-anthracosis group, biomass exposure (48, 67.6% vs. 153, 53.9%, p=0.041), the median pressure of carbon dioxide before six-minute test (42.00 mmHg vs. 40.00 mmHg, P=0.001), the mean peak expiratory flow (115.21 ±23.55 %predicted vs. 104.20±26.17%pre-dicted, P=0.048), the mean level of triglyceride (1.79±1.27 mmol/L vs. 1.51 ±0.74 mmol/L, P=0.034) were significantly increased and the mean oxygen saturation after six-minute test (95.49 ±2.72% vs. 96.56 ±1.27%, P=0.028), the mean cardiac ejection fraction (61.22±2.07% vs.62.08±2.89%, P=0.019) were significantly decreased in the anthracosis group. However, we didn't find significant difference between the two groups in lymph node calcification (p=0.620) and lymphadenectasis (p=0.440). Biomass smoke is a risk factor for anthracosis. Anthracosis produce a bad effect on the oxygenation, cardiac function and lipid metabolism in ILDs patients. The ILDs patients should decrease the exposure of biomass.

AYURVEDIC MANAGEMENT OF BAHUPITTA KAMALA W.S.R. HEPATOCELLULAR JAUNDICEA CASE REPORT

In this era of industrialization and life-threatening competition brings drastically changes in our life style. Most often patient just comes with complaints of "feeling sick and tired". Later it gets diagnosed as kamala (Jaundice). The incidence of such disease is increasing day by day due to change in life style and Eating habits. Jaundice is a condition in which yellowish discoloration of skin, sclera, mucous membranes, excretions occur due to hyperbilirubinemia and deposition of bile pigments. In Ayurveda jaundice is described as Kamlaroga. Kamala has been described in detail along with its aetiology, pathogenesis, symptoms, complications and management also. The description of Hepatocellular jaundice is similar to Ayurvedic description of Kamala vyadhi. This is a case report of 52-year-old female having Bahupittakamala (jaundice), who was treated with some Ayurvedic herbs and Virechana like panchakarma. She got effective results with Ayurvedic Management.

Perioperative anesthetic challenges in Alkaptonuria patient with comorbid conditions

Dear Editor, Alkaptonuria (AKU) is a rare autosomal-recessive inborn error of tyrosine metabolism which is a progressive debilitating disease and symptomatic around 30 years of age. In AKU, patient lacks enzyme required to breakdown homogentisic acid and on exposure to air complains of “black nappies.” Deposition of the onchronosis pigment in the large joints and spine causes joint destruction. In addition, there is involvement of airway, respiratory, renal, cardiac and coagulation system.[1] A 56-year-old man with AKU, G6PD deficiency, hypothyroidism, and hypertension, was scheduled for unilateral total knee arthroplasty. He was receiving levo-thyroxine 50 μg and amlodipine 5 μg once a day (OD). Over a span of 13 years the patient underwent multiple surgeries including lumbar thoracic, cervical fixation and, open cholecystectomy under general anesthesia. Neurological examination revealed hyperreflexia and spasticity in the lower limbs with decreased sensation over S1 dermatome. Airway examination revealed mouth opening of 5 cm, thyromental distance of 5.5 cm, limited neck extension (<10°), and a Mallampati class IV. Rest all investigations were normal. Patient was kept nil per oral prior to surgery and amlodipine and levo-thyroxine on the day of surgery. In the operating theatre, an 18 G intravenous line was secured, mandatory monitoring was attached and a difficult airway cart was kept ready. Patient was asked to self-position on the operation table. Following pre-oxygenation, IV fentanyl 2 μg/kg and propofol 2 mg/kg were administered. After loss of eyelash reflex, a check laryngoscopy was done with video-laryngoscope C-MAC® (Karl Storz, Germany) using a D-Blade which revealed a POGO of 75% with a granular deposit over the left posterior arytenoid, which adequate glottic chink. Vecuronium bromide 0.1 mg/kg was administered and trachea was intubated with 8.5 mm ID. Anesthesia was maintained with nitrous in oxygen, propofol infusion at 50-100 μg/kg/min, and intermittent boluses of vecuronium. At the end of surgery, an ultrasound-guided continuous femoral nerve block with 0.2% ropivacaine 15 ml bolus was performed followed by infusion of ropivacaine 0.2% with fentanyl 2 μg/ml. The surgery lasted for 2 h and vitals were stable during the entire period. 1.5 L of crystalloids were infused. Muscle paralysis was reversed. Black discolouration of heat and moisture exchanger as seen in this patient [Figure 1]. Trachea was extubated and the patient had an uneventful postoperative period.Figure 1: Black discolouration of heat and moisture exchanger in this patientCaring for a patient with AKU ochronosis with multiple comorbidities is challenging. Deposition of HGA in the cartilage of the airway and respiratory system can result in glottic stenosis leading to difficult airway management.[2] HGA deposits also make the dura and the arachnoid membrane vulnerable, therefore central neuraxial techniques were not preferred in the present case.[3] Drug-related precautions were observed for G6PD deficiency.[4] The learning points in this case is the preparedness for anticipated difficult airway, multimodal analgesia and good coordination with orthopedic team for perioperative management. Use of VL with shorter learning curve has changed the management in patients with difficult airway.[56] Since there is no approved treatment for AKU, with every repeated surgery these patients have progressively increasing anaesthetic challenges necessitating meticulous anesthetic management. Financial support and sponsorship Nil. Conflicts of interest There are no conflicts of interest.

XEN1101: A Novel Potassium Channel Modulator for the Potential Treatment of Focal Epilepsy in Adults

Antiseizure medications that reduce seizures via new mechanisms are needed. XEN1101 is an agonist of voltage-gated potassium ion channels (Kv) that was recently shown to reduce focal-onset seizures in a placebo-controlled phase II study. The molecular structure of this potassium channel “opener” is different from ezogabine/retigabine, preventing dimer formation and the pigmentary deposition associated with ezogabine/retigabine treatment. This article reviews the pharmacology and early clinical results for XEN1101.

Ochronosis – a rare metabolic disease

Alkaptonuria is a rare disorder, an autosomal recessive condition with genetic determinism and hereditary transmission, having a prevalence of 1 per 1 million population in USA. The pathogenesis includes the deficiency of the homogentisate 1,2-dioxygenase (HGD) enzyme, an intermediary enzyme in phenylalanine and tyrosine catabolism. Mutations in HGD gene leads to deficient levels of functional HGD and an excess of homogentisic acid (HGA). Although HGA is rapidly excreted by the kidneys, it slowly accumulates in various tissues. Due to HGA oxidase deficiency, HGA turns into melanin-like pigment which determines: alkaptonuria, accumulation in the connective tissues, in the joints, or can make cardiovascular and genitourinary deposits. The chronic accumulation of HGA destroys the affected tissue, leading to the characteristic black-blue color and to clinical symptoms of alkaptonuria. The aim of this paper is to investigate the particularities of rheumatic manifestations in a rare metabolic disease and to support the correct diagnosis. A 58-year-old male patient was admitted to our clinic in 2019 for bilateral knee and left shoulder pain. In 2008 he was diagnosed with polyarticular ochronosis having dorsal and lumbar pain, mixed scapulohumeral pain, lumbar intervertebral disk calcifications; at that time, a diagnosis of ankylosing spondylitis or Forestier disease was excluded. At the current admission, the patient has been thoroughly reassessed to obtain a proper diagnosis and to determine the severity of the disease. The ochronotic axial damage caused important differential diagnosis problems with ankylosing spondylitis. Pigment deposition in the eyes, ears and skin does not cause problems to patients, but cardiovascular and genitourinary deposition leads to important complications. Kinetotherapy and NSAIDs are beneficial for pain symptoms. There is no specific medication for stopping the disease progression. Conclusions. Ochronosis is a rare disease which can cause a lot of problems regarding a proper diagnosis and treatment. When differential diagnosis with AS is difficult, the HLA-B27 genotyping is recommended. Final diagnosis is based on qualitative and quantitative urinary tests. The treatment includes only symptomatic drugs such as NSAIDs and kinetotherapy to improve joint mobility and muscle toning.

High-Grade Fetal Vascular Malperfusion Is Associated With Diffuse Chorionic Hemosiderosis.

Diffuse chorionic hemosiderosis (DCH) is an abnormality of the placental membranes characterized by the deposition of iron pigment. It is usually secondary to recurrent venous bleeding in early pregnancy. In many papers, it is associated with pre-term delivery. Fetal vascular malperfusion (FVM) is an abnormality of the feto-placental circulation that may be seen at any stage of gestation, but most often in the third trimester. It may be graded as low grade (LGFVM) or high grade (HGFVM). No link has been identified in the placental literature between DCH and FVM, but we have noted the 2 co-existing in placentas submitted for analysis. This study explored a possible association of these 2 entities. Laboratory records were searched for singleton cases coded as DCH based on diagnosis on H&E stain over a 6-year period. Of 4478 placentas reported, 66 cases were coded as DCH (1.5%). These were classified as showing HGFVM, LGFVM, or no FVM. Controls (n = 132) were gestational age-matched cases without DCH. Cord length, coiling, insertion, or other abnormalities were noted. Membranes were classified as normal or circumvallate. Results were analyzed using Graphpad. Gestation ranged between 16 and 41weeks gestation. 14/66 (21%) cases of DCH showed HGFVM and 2/66 (3%) showed LGFVM. 16/132 (12%) controls showed HGFVM and 21/132 (15.9%) had LGFVM. Where FVM is present, high-grade FVM is significantly associated with DCH versus controls (P < .0031 Fischer's Test). HGFVM occurs significantly more often in placentas with DCH than in controls. Both FVM and DCH are associated with adverse perinatal outcomes, and a possible relationship between the 2 remains to be clarified.

Yellow nail syndrome

Yellow nail syndrome is an extremely rare syndrome, mainly in people over 50 years of age, occurring both systemically and in isolation and requiring the most careful collection of anamnesis, since this condition has a close relationship with respiratory diseases, malignant neoplasms of internal organs and rheumatoid arthritis. Moreover, this rare disease is not sufficiently studied to fully understand its pathogenesis and effective treatment. Patients pay attention to the yellow color of the nails, associated with the deposition of melanin, bile pigments and hemosiderin in the submarginal space, slowing down the growth and thickening of the nail. It should be noted that the change in the nail plates can be observed long before the other clinical manifestations of this syndrome are detected, and probably this can in some cases serve as a harbinger of incipient changes in the lung tissue, neoplasms and changes in the lymphatic vessels. In this regard, it is extremely important to clearly differentiate this condition and refer patients to related specialists for verification of the diagnosis and further treatment.

Toxic retinopathy and optic neuropathy in long-term tacrolimus intake

Tacrolimus is an effective immunosuppressive agent that is widely used in transplant surgery. Rare complications of its usage include optic neuropathy or maculopathy development.&#x0D; AIM: To present a clinical case of tacrolimus-induced optic neuropathy and retinopathy&#x0D; CLINICAL CASE. A family with a 17-year-old boy was referred to Helmoltz National Medical Research Center of Eye Diseases with complaints of sudden painless decreased vision in his right eye. The best-corrected visual acuity was the right eye of 0.3 and the left eye of 1.0. Ophthalmoscopy of his right eye revealed pigment mottling in the macula and paramacular region, mid-peripheral patchy pigment deposition in 2, 4, and 8 clock meridians. No pathological findings were revealed in his fellow eye. From the anamnesis, 15 years ago, the patient underwent liver transplantation (Alagille syndrome). From the moment of surgery to the date he received tacrolimus. Optical coherence tomography highlighted foveal smoothing, ellipsoid zone and retinal pigment epithelium disruption, macular and paramacular choroid thinning, and neuroretinal rim thickening. Computed microperimetry revealed a significantly decreased sensitivity in the central retinal zone of the right eye. Autofluorescence examination showed multiple punctate hypoautofluorescent spots in the macula and paramacula in the right eye, as well as hyperautofluorescent zones in the posterior pole in both eyes. Electric activity analysis has revealed decreased full-field electroretinogram parameters and P100 amplitude in visually-evoked potentials in the right eye and a decreased a-wave full-field electroretinogram of the left eye. The data provided by the parents suggest that the target tacrolimus concentration in plasma was exceeded 2 times just before the patient noticed vision impairment. Differential diagnoses included infectious and non-infectious posterior uveitis.&#x0D; CONCLUSION: The first case of combined retinopathy and optic neuropathy in adolescents induced by long-term tacrolimus treatment was described.

Systematic Review of the Use of Supplemental Multifocal Intraocular Lenses in the Ciliary Sulcus for Presbyopia Correction.

To conduct a critical review of the peer-reviewed literature on the use of supplemental multifocal intraocular lenses in the ciliary sulcus. This systematic review was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement recommendations. According to the inclusion and exclusion criteria defined, 15 articles were selected for the current systematic review. Each of them was analyzed carefully and their risk of bias was assessed with the Quality Assessment Tool for Case Series Studies from the National Heart, Lung, and Blood Institute. Data of 384 eyes from 227 patients were analyzed. Most of the studies reviewed had a short follow-up and poor or limited design, including case reports, case series, and clinical trials with several gaps in their methodology. Post-operative uncorrected distance and near visual acuity ranged from 20/40 to 20/20 and from 0.4 to 0.02 logMAR, respectively. Pigment dispersion (12 eyes) and deposits (13 eyes) were the most described complication. Dysphotopsia, glare, and halos were the more frequently reported visual disturbances. However, most of the patients reported a high level of satisfaction with their surgery. Most articles reviewed (13 of 15) achieved a risk of bias score between 6 and 8, representing a high level of evidence despite the study design limitations. Supplemental multifocal intraocular lenses seem to offer good distance and near visual results, leading to high levels of spectacle independence and patients' satisfaction, with limited complications associated. However, more studies with a more robust design are needed to confirm these trends. [J Refract Surg. 2021;37(12):830-835.].

Melanosis coli as a factor in the development of colorectal cancer

Melanosis coli is characteristic of patients with a long history of constipation and the use of laxatives – anthraquinone derivatives, which are quite prescribed by doctors and patients independently. As a rule, melanosis develops after 4–9 months of taking drugs from this group and is most common in women in the older age group. Pathogenetically, melanosis is characterized by the deposition of pigment in the lamina propria of the mucous membrane, manifested by a pronounced dark coloration of the mucosa, depending on the degree of pigmentation of the colon, melanosis is divided into three degrees. The most common localization is in the right colon, but cases with the spread of pigmentation to the left colon and other parts have been described. Diagnosis does not cause difficulties, melanosis coli is detected during routine endoscopic examination, and is confirmed by pathomorphological examination. Melanosis is an actual problem in terms of the risk of developing colorectal cancer (CRC). There are already convincing data proving that the frequency of detection of adenomas increases not only due to the absence of pigment accumulation by them, but also the pathogenetic aspects of the influence of melanosis on the occurrence and development of adenomas have been described. Proteomic analysis allows to determine the expression of various proteins, which confirms the role of melanosis in the development of colorectal cancer. It is also interesting to note that sometimes there are some difficulties in the differential diagnosis of melanosis, for example, with ischemic lesions of the colon. Patients with melanosis coli require close attention, timely diagnosis and treatment.

Systemic Review on the Pathogenicity of Plasmodium berghei in the Liver and Spleen of the Experimental Mice

Malaria is still one of the most prevalent tropical and parasitic diseases throughout the world representing a global health concern. Even with all efforts to restrict disease transmission and national malaria control programs, malaria infection continues to cause considerable morbidity and mortality in resource-poor countries. Malaria infection occurs in two stages, the Exoerythrocytic and Erythrocytic stage. The exact biology of malaria parasite in human hosts is likely relatively similar, with the main differences being attributable to the human immune response, the number of previous infections and the exposure profile. The disease severity can be determined by the balance between the pro-inflammatory and anti-inflammatory cytokines. Although, research about the clinical characterization and histology of malaria has shown some information regarding the pathogenesis, the actual mechanisms by which malaria parasites produce severe disease, the immunity defends against infection is remained unknown. Studies in animal models can reveal details about the processes of severe malaria infection and human defense mechanisms. Because of its similarities to the Plasmodium species that cause human malaria, Plasmodium berghei is used as a model organism for the experimental research. In addition, of affecting the central nervous system, Plasmodium berghei infection in the Swiss Webster mouse causes systemic damage, and affects numerous organs including the liver and lymphoid organs. The infected spleen demonstrations includethe splenomegaly, re-modelling and other basic changes consist of the red pulp’s expansion, marginal zone’s slight damage, enlarged vasculature and the barrier cells activities. Moreover, the liver shows hyperplastic Kupffer cells, fatty change, portal tract inflammation, cholestasis, liver cell necrosis, sequestration of Parasitized Red Blood Cells (PRBCs) and deposition of hemozoin pigments.

Usefulness of dermoscopy in the evaluation of patch test reactions

BackgroundDespite being widely used in different areas of dermatology, there have been few studies evaluating the benefit of dermoscopy in the interpretation of patch tests, especially in weak and doubtful reactions. ObjectivesTo evaluate the role of dermoscopy in the interpretation of patch tests and describe the main findings of the reactions. MethodProspective study, carried out in dermatology reference centers in southern Brazil, which evaluated the final results of patch tests analyzed with the aid of dermoscopy. Results77 patients and 160 reactions were included. The most prevalent substances were nickel sulphate (23.8%), kathon CG (9.4%), and perfume mix (8.8%). The main dermoscopic findings were reaction area​​ greater than half of the chamber site (90%), homogeneous erythema (86.9%), vesicles (30%), crusts (21.3%), perifollicular erythema (35%), pore reaction (19.4%) and pustules (8.8%). Dermoscopy was found to facilitate the definition of erythema in reactions on black skin and when due to substances with deposition of pigment. Of the 64 weak or doubtful reactions, 36 (56.25%) showed a change in the final result after dermoscopy evaluation; of the 36 doubtful reactions, 33 (91.6%) showed a change in the final result after dermoscopy evaluation (p < 0.001). Study limitationsThe probable limitation of the study is its sample size. Though certain significance levels have been reached, other possible relationships may not have been observed. ConclusionDermoscopy improves significantly the interpretation of patch tests, especially in weak and doubtful reactions.

Insights Into mRNA and Long Non-coding RNA Profiling RNA Sequencing in Uterus of Chickens With Pink and Blue Eggshell Colors

The blue egg is both of biological interest and economic importance for consumers, egg retailers, and scientists. To date, the genetic mechanisms underlying pigment have mainly focused on protein-coding genes. However, the underpinning mechanism of non-coding RNAs on the pigment deposition among different eggshell colors remains unknown. In this study, RNA sequencing was employed to profile the uterine gland transcriptome (lncRNA and mRNA) of 15 Changshun blue eggshell layers, to better understand the genetic mechanisms of deposition of blue eggshell color. Results showed that differentially expressed mRNAs, GO terms, and KEGG pathways among pink-eggshell and blue-eggshell chickens were mainly targeting immune- and transporter-related terms with the SLC family, IgJ, CD family, and MTMR genes. Furthermore, the progesterone-mediated oocyte maturation and cortisol synthesis and secretion pathway with targeted gene PGR and Pbx1 were significantly enriched between blue- and pink-eggshell chickens. Integrating analysis of lncRNA and mRNA profiles predicted 4 and 25 lncRNA–gene pairs by antisense and cis analysis. They were relative to immune, nerve, and lipids and amino acid metabolisms, porphyrin, and chlorophyll metabolism with targeted gene FECH and oxidative phosphorylation and cardiac muscle contraction pathways with targeted gene COX6A1. Within blue-eggshell chickens, the GO terms hindbrain tangential cell migration and phosphatidylinositol monophosphate phosphatase activity with targeted gene Plxna2 and MTRM1 were identified. Integrating analysis of lncRNA and mRNA profiles predicted 8 and 22 lncRNA–gene pairs. Most pathways were mainly enriched on lipid-related metabolisms as found in mRNA sequencing. The lncRNAs did exert similar functions in color formation by modulating pigment disposition and immune- and lipid-related metabolisms. Our results provide a catalog of chicken uterine lncRNAs and genes worthy of further studies to understand their roles in the selection for blue eggshell color layers.

Phenotypic Switching of B16F10 Melanoma Cells as a Stress Adaptation Response to Fe3O4/Salicylic Acid Nanoparticle Therapy.

Melanoma is a melanocyte-derived skin cancer that has a high heterogeneity due to its phenotypic plasticity, a trait that may explain its ability to survive in the case of physical or molecular aggression and to develop resistance to therapy. Therefore, the therapy modulation of phenotypic switching in combination with other treatment modalities could become a common approach in any future therapeutic strategy. In this paper, we used the syngeneic model of B16F10 melanoma implanted in C57BL/6 mice to evaluate the phenotypic changes in melanoma induced by therapy with iron oxide nanoparticles functionalized with salicylic acid (SaIONs). The results of this study showed that the oral administration of the SaIONs aqueous dispersion was followed by phenotypic switching to highly pigmented cells in B16F10 melanoma through a cytotoxicity-induced cell selection mechanism. The hyperpigmentation of melanoma cells by the intra- or extracellular accumulation of melanic pigment deposits was another consequence of the SaIONs therapy. Additional studies are needed to assess the reversibility of SaIONs-induced phenotypic switching and the impact of tumor hyperpigmentation on B16F10 melanoma’s progression and metastasis abilities.

Ecogeography of Plumage Pigmentation in Great Horned Owls

ABSTRACT Plumage pigmentation is fundamental to a bird's phenotype, with pigment deposition causing relative crypsis or conspicuousness, depending on the environmental context. Geographic variation in plumage melanin tends to be predictable, suggesting that aspects of climate cause local matching of plumage to environment via genetic adaptation. Ecogeographic rules describe this predictability: Gloger's rule predicts that populations in wetter and warmer environments will be more pigmented; Bogert's Rule predicts more pigmentation in cold environments. The Great Horned Owl (Bubo virginianus) exhibits extensive geographic variation in the degree of melanin-based pigmentation. We examined fine-scale spatial variation in owl plumage melanism along environmental gradients in southwestern North America. We tested whether variation is explained by either of two non-mutually exclusive hypotheses: (1) a history of allopatric divergence between subspecies or (2) in situ local adaptation consistent with ecogeographic rules. The allopatric divergence hypothesis predicts a bimodal distribution of plumage melanism, with a geographic cline across a zone of secondary contact, whereas the local adaptation hypothesis predicts that climate explains variation independently of geography. Using a colorimeter, we measured coloration in 101 museum specimens of breeding-season Great Horned Owls that had been obtained from variable environments and elevations. Specimens previously identified as separate subspecies were distinguishable by colorimetry. Plumage lightness, however, was continuously distributed, rather than bimodal. While accounting for males having reduced pigmentation relative to females, linear models revealed that lighter plumage was associated with low latitude, low elevation, high temperature, and low precipitation. These findings suggest that variation in Great Horned Owl plumage pigmentation is best understood as continuous ecogeographic variation, consistent with ecogeographic predictions, and currently maintained in situ along multiple environmental gradients that characterize the “sky island” topography of the southwestern USA.

Identification of pigment genes (melanin, carotenoid and pteridine) associated with skin color variant in red tilapia using transcriptome analysis

Red tilapia (Oreochromis spp.) is an inter-specific hybridization between two tilapia strains by directional breeding. It is favored by consumers due to the color and market value. However, the skin color of red tilapia is unstable and phenotypic segregation with irregular black dots may appear in their offsprings, which is harmful to red tilapia aquaculture industry. To elucidate the mechanisms underlying differential pigmentation in red tilapia, four typical phenotypes were collected for comparative transcriptome analysis. Differentially expressed genes (DEGs) were categorized into three aspects, including melanin, carotenoid and pteridine. The Gene Ontology and KEGG pathways analysis were also done afterwards. We identified candidate genes related to the regulation of pigment synthesis and deposition and the distribution of chromatophores. The genes relevant to melanin synthesis (e.g., pmel, oca2, tyrp1, bmp2, vps11, edn3, ednrb and wnt6) have the higher expression in whole black red tilapia. The genes with the elevated expression level in whole pink tilapia were involved in carotenoid transport and deposition cooperated with lipid metabolism (e.g., scarb1, plin2, stard5, stard10, rbp7, pnpla2, apod and rdh12, etc.), xanthophore formation (e.g., pax7 and gch1). This research would be useful for future genetic studies on the pigmentation of the skin color variation in red tilapia, and it provides a theoretical basis for achieving genetic improvement of red tilapia body-color stability and consistency in red tilapia aquacluture industry.

The Pathogenesis and Management of Acne-Induced Post-inflammatory Hyperpigmentation.

Acne vulgaris is a common inflammatory disease. Among patients with darker skin phototypes (Fitzpatrick III-VI), the inflammatory processes of acne stimulate excess melanogenesis and abnormal melanin deposition, leading to pigmentary sequelae known as post-inflammatory hyperpigmentation and post-inflammatory erythema in all skin tones, although post-inflammatory hyperpigmentation is more common in darker skin and post-inflammatory erythema in lighter skin. These pigmentary alterations can be long lasting and are often more distressing to patients than the active acne lesions. This article discusses what is known about acne-related pigmentation, much of which is extrapolated from general study of nonspecific pigment deposition. Because dyspigmentation poses both a significant clinical concern to patients and a therapeutic challenge to clinicians, we formed a working group consisting of pigmentary experts with the aim of increasing awareness and education of acne-related pigmentary sequelae.