Viral oncogenesis and its role in nonmelanoma skin cancer

In recent years, the contribution of viruses to cutaneous oncogenesis has steadily gained recognition. The archetype is human herpesvirus 8, which is well established as the causative agent in Kaposi sarcoma. Other viruses believed to play a role in nonmelanoma skin cancer include human papillomavirus and the recently described Merkel cell polyomavirus. We review the mechanisms by which these three viruses interact with the host cell, ultraviolet radiation and immunosuppression to result in carcinogenesis.     

Simultaneous acquisition of gradient-echo and asymmetric spin-echo for single-shot z-shim: Z-SAGA.

This article describes the Z-SAGA pulse sequence, a technique for recovering susceptibility losses in EPI images for neuroimaging applications. The pulse sequence is based on an asymmetric spin echo EPI sequence and acquires a gradient echo image and an asymmetric spin echo image in a single shot. For one of the images, a z-shim gradient pulse is applied to compensate for susceptibility-related field distortions. The two images are combined to form an image with reduced signal loss. This sequence is simple to implement and experimentally demonstrated to be effective for BOLD imaging.     

Bacterial invasion of periodontal tissues in advanced periodontitis in humans

Bacterial invasion of the pocket epithelium and underlying connective tissue was found in seven cases of advanced human periodontitis. Four cases showed invasion of the epithelium as well as the connective tissue while in the other three cases bacterial invasion was limited to the pocket epithelium. The microorganisms observed included cocci, rods, filaments, fusiforms and spirochetes and these were morphologically similar to those observed in the apical zone of the subgingival plaque. Most bacteria showed typical Gram-negative cell walls. Bacteria were seen in enlarged epithelial intercellular spaces and among debris of disintegrated epithelial cells. In the connective tissue the bacteria were seen among remnants of collagen fibers and degenerated fibroblasts. Identification of the invading microorganisms may assist in understanding the pathogenesis of chronic periodontitis.     

Voriconazole Exposure and Risk of Cutaneous Squamous Cell Carcinoma,Aspergillus Colonization,Invasive Aspergillosis and Death in Lung Transplant Recipients

Voriconazole is a triazole antifungal used to prevent and treat invasive fungal infections after lung transplantation, but it has been associated with an increased risk of developing cutaneous squamous cell carcinoma (SCC). Despite widespread use, there are no clear guidelines for optimal prophylactic regimens that balance the competing risks and benefits. We conducted a retrospective cohort study of all lung transplant recipients at the University of California, San Francisco, who were transplanted between October 1991 and December 2012 (n = 455) to investigate whether voriconazole exposure affected development of SCC, Aspergillus colonization, invasive aspergillosis and all‐cause mortality. Voriconazole exposure was associated with a 73% increased risk of developing SCC (hazard ratio [HR] 1.73; 95% confidence interval [CI]: 1.04–2.88; p = 0.03), with each additional 30‐day exposure at the standard dose increasing the risk by 3.0% (HR 1.03; 95% CI: 1.02–1.04; p < 0.001). Voriconazole exposure reduced risk of Aspergillus colonization by 50% (HR 0.50; 95% CI: 0.34–0.72; p < 0.001), but we were underpowered to detect risk reduction for invasive aspergillosis. Voriconazole exposure significantly reduced all‐cause mortality among subjects who developed Aspergillus colonization (HR 0.34; 95% CI: 0.13–0.91; p = 0.03) but had no significant impact on those without colonization. Physicians should consider patient‐specific factors that modify the potential risks and benefits of voriconazole for the care of lung transplant recipients.     

Research gaps in the management and prevention of cutaneous squamous cell carcinoma in organ transplant recipients

Although tremendous progress has been made in recent years in skin cancer care for organ transplant recipients, significant gaps remain in data‐driven clinical guidelines, particularly for the treatment and prevention of cutaneous squamous cell carcinoma (cSCC), the most common malignancy among this population. In this review, we aim to summarize current knowledge around the management of cSCC and highlight the most significant gaps in knowledge that continue to pose challenges in the delivery of skin cancer care for organ transplant recipients. We suggest future directions for research that will bridge existing gaps and establish evidence‐driven guidelines for primary prevention, screening and treatment of cSCC in this high‐risk patient population.