Tmem79/Matt is the matted mouse gene and is a predisposing gene for atopic dermatitis in human subjects.

BACKGROUND: Atopic dermatitis (AD) is a major inflammatory condition of the skin caused by inherited skin barrier deficiency, with mutations in the filaggrin gene predisposing to development of AD. Support for barrier deficiency initiating AD came from flaky tail mice, which have a frameshift mutation in Flg and also carry an unknown gene, matted, causing a matted hair phenotype. OBJECTIVE: We sought to identify the matted mutant gene in mice and further define whether mutations in the human gene were associated with AD. METHODS: A mouse genetics approach was used to separate the matted and Flg mutations to produce congenic single-mutant strains for genetic and immunologic analysis. Next-generation sequencing was used to identify the matted gene. Five independently recruited AD case collections were analyzed to define associations between single nucleotide polymorphisms (SNPs) in the human gene and AD. RESULTS: The matted phenotype in flaky tail mice is due to a mutation in the Tmem79/Matt gene, with no expression of the encoded protein mattrin in the skin of mutant mice. Matt(ft) mice spontaneously have dermatitis and atopy caused by a defective skin barrier, with mutant mice having systemic sensitization after cutaneous challenge with house dust mite allergens. Meta-analysis of 4,245 AD cases and 10,558 population-matched control subjects showed that a missense SNP, rs6684514, [corrected] in the human MATT gene has a small but significant association with AD. CONCLUSION: In mice mutations in Matt cause a defective skin barrier and spontaneous dermatitis and atopy. A common SNP in MATT has an association with AD in human subjects.

Antibody-conjugated paramagnetic nanobeads: kinetics of bead-cell binding.

Specific labelling of target cell surfaces using antibody-conjugated paramagnetic nanobeads is essential for efficient magnetic cell separation. However, studies examining parameters determining the kinetics of bead-cell binding are scarce. The present study determines the binding rates for specific and unspecific binding of 150 nm paramagnetic nanobeads to highly purified target and non-target cells. Beads bound to cells were enumerated spectrophotometrically. Results show that the initial bead-cell binding rate and saturation levels depend on initial bead concentration and fit curves of the form A(1 - exp(-kt)). Unspecific binding within conventional experimental time-spans (up to 60 min) was not detectable photometrically. For CD3-positive cells, the probability of specific binding was found to be around 80 times larger than that of unspecific binding.

Child Maltreatment Prevention Service Cases are Significantly Reduced During the COVID-19 Pandemic: A Longitudinal Investigation Into Unintended Consequences of Quarantine.

Unprecedented financial and emotional stress, paired with measures to slow the spread of COVID-19 (e.g., school closures), place youth at risk for experiencing increased rates of abuse. We analyzed data from New York City's Administration for Children's Services to investigate the frequency of child maltreatment prevention service case openings during this time. Longitudinal counts of case openings were compiled for January through June of the years 2014-2020. An independent samples Kruskal-Wallis H-test suggested that pre-quarantine case openings were significantly larger than case openings during quarantine. To account for the possible influence of other historical events impacting data, a secondary Kruskal-Wallis H-test was conducted comparing only the 4 months of quarantine data available to the 4 months immediately preceding quarantine orders. The second independent samples Kruskal-Wallis H-test again suggested that pre-quarantine case openings were significantly larger than case openings during quarantine. A Poisson regression model further supported these findings, estimating that the odds of opening a new child maltreatment prevention case during quarantine declined by 49.17%. These findings highlight the severity of COVID-19 impacts on child maltreatment services and the gap between demand for services and service accessibility. We conclude with recommendations for local governments, community members, and practitioners.

Spiral wave dynamics under feedback via an equilateral triangular sensory domain.

We perform a numerical study of the trajectories of spiral wave cores in excitable systems whose excitability is modulated in proportion to the integral of the activity in a sensory domain in the shape of an equilateral triangle. As a result of this domain shape having vertices opposite sides, unusual forms of lobed limit cycles occur, which are destroyed and then re-form as the domain size is varied. Some key results are also demonstrated experimentally using the light-sensitive Belousov-Zhabotinsky reaction. To characterize the observed behavior, we introduce the concept of express and stagnation zones, which are regions where the trajectory moves particularly rapidly or slowly. The location and strength of the zones far from the domain are accounted for by approximating the parts of the spiral wave crossing the domain by a series of plane waves.