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The clinical and histological findings in two cases of tick bite alopecia of the scalp are described and possible pathogenetic mechanisms discussed. It is suggested that the central hair loss is the result of tissue necrosis, while the surrounding alopecia is either due to precipitate and abnormal telogen caused by the digestive tick saliva which becomes progressively diluted and less destructive as it spreads through the tissues or alternatively to an unknown toxin present in the salvia of the offending tick. [ABSTRACT FROM AUTHOR]

The clinical and histologic features of sucking pads in neonutes are clearly different From sucking blisters arid leukoedema, both of which may also be present in neonates. We propose that the condition is due Lo a combination of intracellular edema and hyperkeratosis. Perhaps the alternative term of sucking calluses is mow appropriate. The intracelular edemata is ascribed to passive diffusion of fluid, presumably saliva, into the cells. While the hyperkeratosis is regarded as an adaptive phenomenon to fraction during sucking. [ABSTRACT FROM AUTHOR]

The dermatological findings in five patients with thallium poisoning are described. Cutaneous involvement consisted mainly of an acneiform eruption, pellagra-like dyssebacea, crusted eczematous lesions and dry scaling of the distal parts of the extremities. Alopecia was not evident initially but later became apparent. The patients also had gastrointestinal and neurological symptoms and signs. [ABSTRACT FROM AUTHOR]

We report pathognomonic skin lesions of malignant atrophic papulosis, accompanied by lethal central nervous system and gastrointestinal disease in a 22-year-old black man Histopathological studies of the brain and colon showed areas of infarction and an underlying vasculitis with leukocytoclasis. [ABSTRACT FROM AUTHOR]

A patient with post-inflammatory cutis laxa and primary aortitis is described. Certain cases of primary aortitis or post-inflammatory cutis laxa occurring per se can be considered as polar variations of the same disease. [ABSTRACT FROM AUTHOR]

The article presents information about lipoid proteinosis. It is a rare dermatosis of which perhaps a hundred cases have been observed. The clinical features are hoarseness, cutaneous and mucosal lesions, alopecia, pruritus, photosensitivity and soft tissue calcifications, usually intracranial. The skin manifestations may be elevated yellowish-white or brownish papules or hyperkeratotic verrucous lesions, and atrophic scars are common. Bullous lesions are occasionally observed. The article also includes other information about the disease.

The histolgical findings after ultraviotet irradiation and mechanical trauma in patients with Darier's disease are reported. The action spectrum for the elicitation of lesions by u.v. light has been found to lie between 250 and 300 nm. Exacerbations of Darier's disease by diverse external irritants are interpreted as Koebner phenomena which do not elucidate the biochemical defect in the disease. [ABSTRACT FROM AUTHOR]

Marek's disease virus (MDV) is an oncogenic alphaherpesvirus that causes deadly lymphomas in chickens. In chickens, up to 50% of all peripheral T cells are gamma delta (γδ) T cells. Until now, their role in MDV pathogenesis and tumor formation remains poorly understood. To investigate the role of γδ T cells in MDV pathogenesis, we infected recently generated γδ T cell knockout chickens with very virulent MDV. Strikingly, disease and tumor incidence were highly increased in the absence of γδ T cells, indicating that γδ T cells play an important role in the immune response against MDV. In the absence of γδ T cells, virus replication was drastically increased in the thymus and spleen, which are potential sites of T cell transformation. Taken together, our data provide the first evidence that γδ T cells play an important role in the pathogenesis and tumor formation of this highly oncogenic herpesvirus.IMPORTANCEGamma delta (γδ) T cells are the most abundant T cells in chickens, but their role in fighting pathogens remains poorly understood. Marek's disease virus (MDV) is an important veterinary pathogen, that causes one of the most frequent cancers in animals and is used as a model for virus-induced tumor formation. Our study revealed that γδ T cells play a crucial role in combating MDV, as disease and tumor incidence drastically increased in the absence of these cells. γδ T cells restricted virus replication in the key lymphoid organs, thereby decreasing the likelihood of causing tumors and disease. This study provides novel insights into the role of γδ T cells in the pathogenesis of this highly oncogenic virus., Competing Interests: The authors declare no conflict of interest.

The availability of genetically modified mice has facilitated the study of mammalian T cells. No model has yet been developed to study these cells in chickens, an important livestock species with a high availability of γδ T cells. To investigate the role of γδ and αβ T cell populations in birds, we generated chickens lacking these T cell populations. This was achieved by genomic deletion of the constant region of the T cell receptor γ or β chain, leading to a complete loss of either γδ or αβ T cells. Our results show that a deletion of αβ T cells but not γδ T cells resulted in a severe phenotype in KO chickens. The αβ T cell KO chickens exhibited granulomas associated with inflammation of the spleen and the proventriculus. Immunophenotyping of αβ T cell KO chickens revealed a significant increase in monocytes and expectedly the absence of CD4 + T cells including FoxP3 + regulatory T cells. Surprisingly there was no increase of γδ T cells. In addition, we observed a significant decrease in immunoglobulins, B lymphocytes, and changes in the bursa morphology. Our data reveal the consequences of T cell knockouts in chickens and provide new insights into their function in vertebrates., (© 2023 The Authors. European Journal of Immunology published by Wiley-VCH GmbH.)

The continental margin off the northeastern United States (NEUS) contains numerous, topographically complex features that increase habitat heterogeneity across the region. However, the majority of these rugged features have never been surveyed, particularly using direct observations. During summer 2013, 31 Remotely-Operated Vehicle (ROV) dives were conducted from 494 to 3271 m depth across a variety of seafloor features to document communities and to infer geological processes that produced such features. The ROV surveyed six broad-scale habitat features, consisting of shelf-breaching canyons, slope-sourced canyons, inter-canyon areas, open-slope/landslide-scar areas, hydrocarbon seeps, and Mytilus Seamount. Four previously unknown chemosynthetic communities dominated by Bathymodiolus mussels were documented. Seafloor methane hydrate was observed at two seep sites. Multivariate analyses indicated that depth and broad-scale habitat significantly influenced megafaunal coral (58 taxa), demersal fish (69 taxa), and decapod crustacean (34 taxa) assemblages. Species richness of fishes and crustaceans significantly declined with depth, while there was no relationship between coral richness and depth. Turnover in assemblage structure occurred on the middle to lower slope at the approximate boundaries of water masses found previously in the region. Coral species richness was also an important variable explaining variation in fish and crustacean assemblages. Coral diversity may serve as an indicator of habitat suitability and variation in available niche diversity for these taxonomic groups. Our surveys added 24 putative coral species and three fishes to the known regional fauna, including the black coral Telopathes magna, the octocoral Metallogorgia melanotrichos and the fishes Gaidropsarus argentatus, Guttigadus latifrons, and Lepidion guentheri. Marine litter was observed on 81% of the dives, with at least 12 coral colonies entangled in debris. While initial exploration revealed the NEUS region to be both geologically dynamic and biologically diverse, further research into the abiotic conditions and the biotic interactions that influence species abundance and distribution is needed.

A patient who presented with erythema multiforme on clinical and histological examination but who subsequently developed fatal, fulminant systemic lupus erythematosus is reported. The prognostic significance of the development of erythema multiforme-type lesions in lupus erythematosus is discussed with reference to cases reported by Rowell et al. and Provost et al. The term 'Rowell's syndrome' is best avoided.

A hitherto undescribed inherited dermatosis, traceable to certain 19th-century inhabitants of Oudtshoorn, CP, has been transmitted as an autosomal dominant to a large number of their present-day descendants. The disease consists of intermittent and recurrent centrifugal peeling, with redness, of the palms and soles in particular. In more severe cases similar patches are found extending up the limbs to the buttocks and the trunk generally. The inconvenience is usually moderate, but it may be incapacitating. Some temporary relief, but so far nothing permanent, can be offered through treatment.

Smodingium argutum is the plant most commonly responsible for causing acute allergic contact dermatitis in South Africa. When an outbreak of Smodingium dermatitis occurred in a local school the allergenic principle present in this plant was chemically isolated and identified, and its allergenic property proved in the clinic by patch testing. The value of using an extract of fresh Smodingium leaves in lieu of fresh leaves themselves was confirmed, but freeze-dried material was found to be unsuitable for patch-test purposes.