Alcobiosis, an algal-fungal association on the threshold of lichenisation.

Alcobiosis, the symbiosis of algae and corticioid fungi, frequently occurs on bark and wood. Algae form a layer in or below fungal basidiomata reminiscent of the photobiont layer in lichens. Identities of algal and fungal partners were confirmed by DNA barcoding. Algal activity was examined using gas exchange and chlorophyll fluorescence techniques. Carbon transfer from algae to fungi was detected as 13C, assimilated by algae, transferred to the fungal polyol. Nine fungal partners scattered across Agaricomycetes are associated with three algae from Trebouxiophycae: Coccomyxa sp. with seven fungal species on damp wood, Desmococcus olivaceus and Tritostichococcus coniocybes, both with a single species on bark and rain-sheltered wood, respectively. The fungal partner does not cause any obvious harm to the algae. Algae enclosed in fungal tissue exhibited a substantial CO2 uptake, but carbon transfer to fungal tissues was only detected in the Lyomyces-Desmococcus alcobiosis where some algal cells are tightly enclosed by hyphae in goniocyst-like structures. Unlike lichen mycobionts, fungi in alcobioses are not nutritionally dependent on the algal partner as all of them can live without algae. We consider alcobioses to be symbioses in various stages of co-evolution, but still quite different from true lichens.

Pathogenic variants in the SPTLC1 gene cause hyperkeratosis lenticularis perstans.

BACKGROUND: Hyperkeratosis lenticularis perstans (HLP), also known as Flegel disease, is a rare skin disease presenting with asymptomatic small hyperkeratotic papules. The lesions often appear on the dorsal feet and lower legs, and typically develop after the fourth decade of life. A genetic basis for HLP is suspected; however, so far no gene defect linked to the development of HLP has been identified. OBJECTIVES: We aimed to identify the genetic cause of HLP. METHODS: For mutational analysis we studied a cohort of five patients with HLP using next-generation sequencing (NGS). We used DNA -extracted from fresh skin biopsies alongside ethylenediamine tetraacetic acid (EDTA) blood samples from two patients, and formalin-fixed -paraffin-embedded skin biopsy material from three patients. In addition, immunofluorescence staining of HLP lesions from four patients was investigated. RESULTS: In all samples from the five patients with HLP we identified by NGS rare variants in the SPTLC1 gene. In four patients we detected small deletions/frameshift variants and in one patient a splicing variant, predicted to disturb the splicing process. In blood samples the detected variants were heterozygous with an allele frequency of 49% and 50%, respectively. In skin biopsies the allele frequency was within the range of 46-62%. Immunofluorescence staining revealed reduced SPTLC1 protein levels in skin of patients. CONCLUSIONS: Our findings suggest that pathogenic variants in the SPTLC1 gene are the underlying genetic cause of HLP. Of note, the identified variants were either frameshift- or splicing variants probably leading to nonsense-mediated mRNA decay and thus reduced SPTLC1 protein levels. We conclude that diminished SPTLC1, the key enzyme in sphingolipid biosynthesis, leads to the development of HLP, which highlights the sphingolipid pathway as a new therapeutic target.

Generalized, Linear Hyperkeratotic Papules With Numerous White Spicules and Comedo-like Plugs.

A school-aged boy presents with generalized, linear hyperkeratotic papules with numerous central small filiform keratotic white spicules and brown plugs on the head, face, neck, trunk, and bilateral upper and lower extremities. What is your diagnosis?

Histopathological analysis of chronic paronychia.

BACKGROUND: Chronic paronychia is an inflammatory process of the nail folds lasting more than 6 weeks. Clinically, there is hypertrophy and retraction of the folds and absence of the cuticle. Treatment involves clinical measures and, when there is no response or the hypertrophy of the folds is very pronounced, surgical treatment is indicated. Post-surgical histopathology is little studied in the literature. In this sense, we believe that the histopathological study is important not only for the individualized understanding of the patient's chronic disease, avoiding relapses, but also for the understanding of its pathophysiology and treatment possibilities. OBJECTIVE: To describe the histopathological changes found in biopsies of the proximal nail fold of patients with chronic paronychia undergoing surgical treatment. MATERIALS AND METHODS: A histopathological study of 16 nail folds from 6 patients after surgery was performed at 2 study centers. RESULTS: The most prevalent epidermal findings were orthokeratosis, hypergranulosis, acanthosis and spongiosis and the dermal findings were fibrosis and mononuclear inflammatory infiltrate. CONCLUSION: The histopathological study allowed us to conclude that chronic paronychia is primarily an inflammatory process, but it is not possible to conclude whether microorganisms such as Candida and bacterial cocci are part of the etiology or just secondary and opportunistic agents.

[Verrucous exophytic tumor of the glans penis]. / Verruköser exophytischer Tumor der Glans penis.

A 59-year-old man presented with a growing tumor on the glans penis, which we excised. Histologically, there was an acanthotic epidermis under which the papillary dermis was filled with foamy macrophages, best seen in a CD 68 stain. Verruciform xanthoma was diagnosed. Knowledge of this benign diagnosis may prevent an overly hasty, aggressive approach, since the differential diagnosis of penile carcinoma requires much more radical therapy, and mutilating penile surgery is associated with considerable psychosexual distress for patients.

Treponema spp. spirochetes and keratinopathogenic fungi isolated from keratomas in donkeys.

Keratoma is an aberrant keratin mass thought to originate from epidermal horn-producing cells interposed between the stratum medium of the hoof wall and the underlying third phalanx. The cause is unknown, although the presence of keratomas is frequently associated with chronic irritation, focal infection, or trauma. A total of 167 donkeys with keratomas were presented in this study. The diagnosis of a keratoma was based on clinical signs, radiography, and histopathologic examination. Surgical excision was attempted on all donkeys with lameness unless euthanasia was advised. Histopathologic examination, including Giemsa, periodic acid Schiff, and Young's silver special histochemical stains, was performed and showed the presence of fungal hyphae and spirochete bacteria within the degenerate keratin. Polymerase chain reaction (PCR) for treponeme bacteria was performed on 10 keratoma lesions and 9 healthy pieces of hoof (controls). All healthy donkey tissues were negative for the 3 recognized digital dermatitis (DD) treponeme phylogroups, whereas 3 of 10 (30%) donkey keratoma samples were positive for one of the DD treponeme phylogroups. Routine fungal culture and PCR for fungi were performed on 8 keratoma lesions and 8 healthy pieces of hoof (controls). Keratinopathogenic fungi were detected in 1 of 8 (12.5%) keratomas, while only non-keratinopathogenic, environmental fungi were detected in 8 control healthy hoof samples. This is the first time the DD treponemes phylogroup and keratinopathogenic fungi have been detected in keratomas. Further studies are required to assess the significance of this finding.

Metabolomic Profiling, Antioxidant and Enzyme Inhibition Properties and Molecular Docking Analysis of Antarctic Lichens.

The lichen species Lecania brialmontii, Pseudephebe pubescens, and Sphaerophorus globosus are part of the prominent lichenoflora of the Antarctic territory. In this work, we report the metabolomic identification of ethanolic extracts of these species, their antioxidant and cholinesterase enzyme inhibitory activity, and conduct a molecular docking analysis with typical compounds. Eighteen compounds were identified by UHPLC-ESI-QTOF-MS in L. brialmontii, 18 compounds in P. pubescens, and 14 compounds in S. globosus. The content of phenolic compounds was variable among the species, ranging from 0.279 to 2.821 mg AG/g, and all three species showed high inhibition potential on the cholinesterase enzymes. Molecular docking showed important interactions between AChE and BChE with the selected compounds. This study evidences the chemical fingerprint of three species of the order Lecanorales that support the continuation of the study of other biological activities and their potential for medical research.

Computer Aided Diagnosis of Melanoma Using Deep Neural Networks and Game Theory: Application on Dermoscopic Images of Skin Lesions.

Early detection of melanoma remains a daily challenge due to the increasing number of cases and the lack of dermatologists. Thus, AI-assisted diagnosis is considered as a possible solution for this issue. Despite the great advances brought by deep learning and especially convolutional neural networks (CNNs), computer-aided diagnosis (CAD) systems are still not used in clinical practice. This may be explained by the dermatologist's fear of being misled by a false negative and the assimilation of CNNs to a "black box", making their decision process difficult to understand by a non-expert. Decision theory, especially game theory, is a potential solution as it focuses on identifying the best decision option that maximizes the decision-maker's expected utility. This study presents a new framework for automated melanoma diagnosis. Pursuing the goal of improving the performance of existing systems, our approach also attempts to bring more transparency in the decision process. The proposed framework includes a multi-class CNN and six binary CNNs assimilated to players. The players' strategies is to first cluster the pigmented lesions (melanoma, nevus, and benign keratosis), using the introduced method of evaluating the confidence of the predictions, into confidence level (confident, medium, uncertain). Then, a subset of players has the strategy to refine the diagnosis for difficult lesions with medium and uncertain prediction. We used EfficientNetB5 as the backbone of our networks and evaluated our approach on the public ISIC dataset consisting of 8917 lesions: melanoma (1113), nevi (6705) and benign keratosis (1099). The proposed framework achieved an area under the receiver operating curve (AUROC) of 0.93 for melanoma, 0.96 for nevus and 0.97 for benign keratosis. Furthermore, our approach outperformed existing methods in this task, improving the balanced accuracy (BACC) of the best compared method from 77% to 86%. These results suggest that our framework provides an effective and explainable decision-making strategy. This approach could help dermatologists in their clinical practice for patients with atypical and difficult-to-diagnose pigmented lesions. We also believe that our system could serve as a didactic tool for less experienced dermatologists.

Mechanic Hands/Hiker Feet in a Patient With Amyopathic Dermatomyositis and Interstitial Lung Disease.

ABSTRACT: A 30-year-old African American woman with a history of interstitial lung disease presented with bilaterally symmetrical, nonpruritic, scaling and fissuring, hyperpigmented, lichenified plaques on her hands and feet. She reported occasional erythema of her face, intermittent erythema, and irritation of her eyes but denied any muscle weakness. A biopsy of the plantar first toe showed hyperkeratosis, striking alternating ortho- and parakeratosis with underlying apoptotic bodies. There was psoriasiform acanthosis without suprapapillary thinning, numerous apoptotic keratinocytes in all layers of the epidermis extending into the corneum that were out of proportion with the minimal interface inflammation. Colloidal iron and Alcian blue stains showed increased dermal mucin deposition. Given the clinical, histopathological, and supportive serological findings (positive anti-KU and anti-SSA), a diagnosis of clinically amyopathic dermatomyositis with mechanic hand/hiker feet (MH/HF) was rendered. The pseudocheckerboard pattern of MH/HF has been previously reported in only 4 patients. The most frequent associations with MH/HF are dermatomyositis and antisynthetase syndrome; however, our patient was negative for antiaminoacyl transfer RNA synthetase antibodies, a required criterion to diagnose antisynthetase syndrome. It is imperative to recognize MH/HF clinically and histopathologically because it may be an early indication of developing dermatomyositis or other connective tissue diseases, which would guide further workup and screening for systemic involvement of the disease, including interstitial lung disease.

Bowen Disease Within a Circumscribed Palmar Hypokeratosis.

ABSTRACT: Circumscribed palmar or plantar hypokeratosis is a focal disorder of keratinization that consists of a reduction in the thickness of the corneal layer of the epidermis of palms or soles. Although it is considered a benign entity, the thinning of the stratum corneum facilitates ultraviolet damage in the affected skin, which may result in an increased risk of developing focal epidermal dysplasia. Other factors, such as immunosuppression in transplanted patients, may play a role as well. We present a case of circumscribed palmar or plantar hypokeratosis with features of Bowen disease limited to the hypokeratotic epidermis.