The dermis promotes the development and maintains the functional components of skin, such as hair follicles, sweat glands, nerves and blood vessels. The dermis is also crucial for wound healing and homeostasis of the skin. The dermis originates from the somites, the lateral plate mesoderm and the cranial neural crest. Despite the importance of the dermis in the structural and functional integrity of the skin, genetic analysis of dermal development in different parts of the embryo is incomplete. The signaling requirements for ventral dermal cell development have not been established in either the chick or the mammalian embryo. We have shown previously that Wnt signaling specifies the dorsal dermis from the somites. In this study, we demonstrate that Wnt/β-catenin signaling is necessary for the survival of early ventral dermal progenitors. In addition, we show that, at later stages, Wnt/β-catenin signaling is sufficient for ventral dermal cell specification. Consistent with the different origins of dorsal and ventral dermal cells, our results demonstrate both conserved and divergent roles of β-catenin/Wnt signaling in dermal development.

Fatty liver disease in humans can progress from steatosis to hepatocellular injury, fibrosis, cirrhosis, and liver failure. We developed a series of straightforward assays to determine whether zebrafish larvae with either tunicamycin-or ethanol-induced steatosis develop hepatic dysfunction. We found altered expression of genes involved in acute phase response and hepatic function, and impaired hepatocyte secretion and disruption of canaliculi in both models, but glycogen deficiency in hepatocytes and dilation of hepatic vasculature occurred only in ethanol-treated larvae. Hepatic stellate cells (HSCs) become activated during liver injury and HSC numbers increased in both models. Whether the excess lipids in hepatocytes are a direct cause of hepatocyte dysfunction in fatty liver disease has not been defined. We prevented ethanol-induced steatosis by blocking activation of the sterol response element binding proteins (Srebps) using gonzo mbtps1 mutants and scap morphants and found that hepatocyte dysfunction persisted even in the absence of lipid accumulation. This suggests that lipotoxicity is not the primary cause of hepatic injury in these models of fatty liver disease. This study provides a panel of parameters to assess liver disease that can be easily applied to zebrafish mutants, transgenics, and for drug screening in which liver function is an important consideration.

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Inhaled bronchodilators are the cornerstone of treatment for chronic obstructive pulmonary disease (COPD). Soft mist inhalers (SMIs) are devices that deliver bronchodilators. Although correct device use is paramount to successful medication delivery, patient errors are common. This global systematic literature review and meta-analysis examined device use errors with SMIs among patients with obstructive lung diseases. PubMed, EMBASE, PsycINFO, Cochrane, and Google Scholar were searched to identify studies published between 2010 and 2019 that met the following inclusion criteria: (a) English language; (b) a diagnosis of COPD, bronchitis, or emphysema; and (c) reported device use errors among adults receiving long-acting bronchodilator treatment with Respimat® SMI (i.e. Spiriva®, Stiolto®, Spiolto®, and Striverdi®). Descriptive statistics examined sociodemographics, clinical characteristics, and device use errors. Meta-analysis techniques were employed with random-effects models to generate pooled mean effect sizes and 95% confidence intervals (CIs) for overall and step-by-step errors. The I 2 statistic measured heterogeneity. Twelve studies ( n = 1288 patients) were included in this meta-analysis. Eighty-eight percent of patients had COPD, and most had moderate/very severe airflow limitation (Global Initiative for Chronic Obstructive Lung Disease spirometric stages II to IV). Aggregate results revealed that 58.9% (95% CI: 42.4–75.5; I 2 = 92.8%) of patients made ≥1 device use errors. Among 11 studies with step-by-step data, the most common errors were failure to (1) exhale completely and away from the device (47.8% (95% CI: 33.6–62.0)); (2) hold breath for up to 10 seconds (30.6% (95% CI: 17.5–43.7)); (3) take a slow, deep breath while pressing the dose release button (27.9% (95% CI: 14.5–41.2)); (4) hold the inhaler upright (22.6% (95% CI: 6.2–39.0)); and (5) turn the base toward the arrows until it clicked (17.6% (95% CI: 3.0–32.2)). Device use errors occurred in about 6 of 10 patients who used SMIs. An individualized approach to inhalation device selection and ongoing training and monitoring of device use are important in optimizing bronchodilator treatment.

Obesity does not adversely influence the severity or the resolution of acute episodes of asthma.