Publications by authors named "David R Bickers"

Most allergic reactions to antibiotics are caused by β-lactam antibiotics; however non-β-lactam antibiotics are also capable of causing both immediate allergic reactions as well as late-type reactions to these drugs. This is especially true for fluoroquinolones and sulfonamides. Of these, the combination of sulfamethoxazole with trimethoprim (Cotrimoxazol, e.

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Skin cancer affects 1 in 5 Americans, resulting in significant morbidity and mortality. Treatment costs and rates of skin cancer and melanoma continue to rise, making preventative measures increasingly important. However, there is conflicting evidence about efficacy of primary and secondary prevention strategies in decreasing incidence and improving early diagnosis.

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The study of dominantly heritable cancers has provided insights about tumor development. Gorlin syndrome (GS) is an autosomal dominant disorder wherein affected individuals develop multiple basal cell carcinomas (BCCs) of the skin. We developed a murine model of Ptch1 haploinsufficiency on an ornithine decarboxylase (ODC) transgenic background (Ptch1/ODC/C57BL/6) that is more sensitive to BCCs growth as compared with Ptch1/ODC/C57BL/6 littermates.

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Currently available smoothened targeted therapies in patients with basal cell nevus syndrome are associated with substantial tumor recurrence and clinical resistance. Strategies bypassing smoothened and/or identifying additional downstream components of the Hedgehog pathway could provide novel antitumor targets with a better therapeutic index. Sry-related high mobility group box 9 (SOX9) is a Hedgehog/glioma-associated oncogene homolog-regulated transcription factor known to be overexpressed in basal cell carcinomas (BCCs).

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Background: Aberrant hedgehog signalling underlies the development of basal-cell carcinomas. We previously reported the interim analysis of a multicentre, randomised, double-blind, placebo-controlled, phase 2 trial in patients with the basal-cell nevus (Gorlin) syndrome indicating that the smoothened inhibitor vismodegib reduces basal-cell carcinoma tumour burden and prevents new basal-cell carcinoma growth in patients with basal-cell nevus syndrome. We report the final results of this 36 month trial.

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Patients with basal cell nevus syndrome (BCNS), also known as Gorlin syndrome, develop numerous basal cell carcinomas (BCC) due to germline mutations in the tumor suppressor PTCH1 and aberrant activation of Hedgehog (Hh) signaling. Therapies targeted at components of the Hh pathway, including the smoothened (SMO) inhibitor vismodegib, can ablate these tumors clinically, but tumors recur upon drug discontinuation. Using SKH1-Ptch1 as a model that closely mimics the spontaneous and accelerated growth pattern of BCCs in patients with BCNS, we show that AKT1, a serine/threonine protein kinase, is intrinsically activated in keratinocytes derived from the skin of newborn Ptch1 mice in the absence of carcinogenic stimuli.

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Article Synopsis
  • Nevoid basal cell carcinoma syndrome (NBCCS) is a rare genetic disorder mainly caused by mutations in the Ptch1 gene, leading to abnormal Shh signaling.
  • Ptch1+/-/SKH-1 mice have been developed as a new model for NBCCS, demonstrating symptoms similar to human patients, including sensitivity to UV and the development of multiple basal cell carcinomas (BCCs).
  • Treatment with smoothened inhibitors and anti-inflammatory drugs shows promise in reducing BCCs, but the most effective results are achieved with a combined approach targeting both p50-NFκB/Bcl3 and Shh signaling pathways.
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The year 2014 marks the centennial of events that led to the First World War ("the war to end all wars") following the assassination of Archduke Ferdinand of the crumbling Austro-Hungarian Empire. It also marks the 120th anniversary of the birth of Stephen Rothman and the 60th anniversary of the publication of his epic textbook The Physiology and Biochemistry of the Skin. In this review, we document our belief that Rothman had a seismic impact on moving investigative dermatology from a medical backwater to a scientific discipline that can hold its own with any other specialty.

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The hedgehog (Hh) signaling pathway is considered to be a major signal transduction pathway during embryonic development, but it usually shuts down after birth. Aberrant Sonic hedgehog (Shh) activation during adulthood leads to neoplastic growth. Basal cell carcinoma (BCC) of the skin is driven by this pathway.

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p38 mitogen-activated protein kinases (MAPKs) respond to a wide range of extracellular stimuli. While the inhibition of p38 signaling is implicated in the impaired capacity to repair ultraviolet (UV)-induced DNA damage-a primary risk factor for human skin cancers-its mechanism of action in skin carcinogenesis remains unclear, as both anti-proliferative and survival functions have been previously described. In this study, we utilized cultured keratinocytes, murine tumorigenesis models, and human cutaneous squamous cell carcinoma (SCC) specimens to assess the effect of p38 in this regard.

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Hairless mice carrying homozygous mutations in hairless gene manifest rudimentary hair follicles (HFs), epidermal cysts, hairless phenotype, and enhanced susceptibility to squamous cell carcinomas. However, their susceptibility to basal cell carcinomas (BCCs), a neoplasm considered originated from HF-localized stem cells, is unknown. To demonstrate the role of HFs in BCC development, we bred Ptch(+/-)/C57BL6 with SKH-1 hairless mice, followed by brother-sister cross to get F2 homozygous mutant (hairless) or wild-type (haired) mice.

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Importance: Keratocystic odontogenic tumors (KCOTs) of the jaw affect more than 65% of patients with basal cell nevus syndrome (BCNS). Surgery frequently causes facial disfigurement and is not always curative. Most BCNS-related and some sporadic KCOTs have malignant activation of the Hedgehog signaling pathway.

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Sporadic human basal cell carcinomas (BCC) are generally well managed with current surgical modalities. However, in the subset of high-risk patients predisposed to developing large numbers of BCCs, there is an unmet need for effective, low-morbidity chemoprevention. This population includes fair-skinned patients with extensive sun exposure and those with genodermatoses such as the basal cell nevus (Gorlin) syndrome (BCNS).

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Retinoids are known to affect skin cell proliferation and differentiation and are key molecules that target retinoid and retinoic acid receptors (RXRs and RARs), leading to physiological and pharmacologic effects. Our aim was to elucidate the role of the retinol-binding protein receptor STRA6, mediating cellular uptake of retinol, on skin structure and function. Our results indicate that STRA6 is constitutively expressed in human epidermal keratinocytes and dermal fibroblasts and is regulated via RAR/RXR-mediated pathways.

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Following World War II, dermatology in German-speaking Europe faced enormous challenges, including the need to rebuild damaged or destroyed facilities, the replacement of the loss of many prewar leaders, and a raging venereal disease epidemic. Restoration of academic excellence and leadership required that young German-speaking dermatologists had to seek additional training in the United States, thereby reversing the historical trends of the 19th and early 20th centuries. Some of the initial visitors included Herbert Goldschmidt, Egon Macher, Gerd Steigleder, and Klaus Wolff.

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The rise to power of the National Socialist (Nazi) party led by Adolf Hitler and the subsequent tumultuous 12 years of their rule in Germany resulted in catastrophes including World War II, the most destructive war ever, and the premeditated and systematic murder of 5 to 6 million European Jews. Despite their notable contributions to the academic excellence that existed in German-speaking countries at that time, Jewish physicians were particularly vulnerable to persecution and death. Between 1933 and 1938, a series of repressive measures eliminated them from the practice of medicine in Germany and other countries.

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Arsenic exposure is known to disrupt innate immune functions in humans and in experimental animals. In this study, we provide a mechanism by which arsenic trioxide (ATO) disrupts macrophage functions. ATO treatment of murine macrophage cells diminished internalization of FITC-labeled latex beads, impaired clearance of phagocytosed fluorescent bacteria and reduced secretion of pro-inflammatory cytokines.

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