Harrison P. Nguyen

The biology of human papillomaviruses.

Human papillomaviruses (HPVs) are small, double-stranded DNA viruses that cause lesions in cutaneous and mucosal tissue and are responsible for carcinomas of the cervix, vagina, vulva and penis. HPVs sort into 5 genera with a total of approximately 150 species that have been sequenced. Its genome is comprised of an early (E) region encoding the viral regulatory proteins, a late (L) region encoding the viral structural proteins and a noncoding region that is essential to the viral life cycle. For infection to occur, the virus must access the basal epidermal layer where, following endocytosis and viral capsid disassembly, the L2 protein mediates viral genome transfer to the nuclei of mitotic keratinocytes. The viral genome is maintained in episomal form during the normal life cycle and replicates in synchrony with the host cell DNA under the mediation of E1, E2, E4 and E5 viral proteins. In most high-grade cervical neoplasms, however, the viral DNA is integrated into the host genome through the disruption of the E2 open reading frame. The oncoproteins E6 and E7, which were previously suppressed by E2, are then free to inhibit the Rb and p53 tumor suppressor pathways. The viral life cycle concludes with the packaging of the viral genome and virus release, which entails the E2-mediated recruitment of L2 to regions of replication, the expression of L1 and the assembly of the icosahedral capsid in the nucleus. Overall, the complex biology of HPV continues to be an important area of research with substantial implications for public health.

Apoptotic Gene Expression in Sinecatechins-Treated External Genital and Perianal Warts

External genital and perianal warts (EGW)—the most common viral sexually transmitted disease in the United States—are caused by the human papillomavirus (HPV), a family of DNA viruses with more than 150 genotypes characterized to date (7). In 2006, sinecatechins ointment 15% (trade name Veregen ) was approved by the Food and Drug Administration for the treatment of EGW. Sinecatechins ointment is comprised of a proprietary blend of eight different catechins, the chief family of flavonoids believed to account for the wide array of health benefits attributed to green tea (12). In decreasing order of concentration, the four major catechins found in green tea are epigallocatechin gallate, epigallocatechin, epicatechin gallate, and epicatechin. Prior to their application for treating viral disease, catechins had been associated with a wide array of health benefits (10). Although it is believed that the majority of these health benefits are due to the catechins’ antioxidative activity, green tea catechins have also displayed poorly understood antiproliferative and antiviral properties (10). In vitro, epigallocatechin gallate can induce apoptotic growth inhibition of four HPV-infected tumor cell lines, and in vivo, green tea catechins were found to be effective in treating cervical HPV lesions, as determined by positive morphological changes of cervical lesions and a decrease of HPV DNA levels following treatment (8,11). However, despite these observations and FDA approval nearly a decade ago, the mechanism of action of sinecatechins-induced growth inhibition of EGW is unknown. To begin to answer this question, we performed an openlabel, single-site study enrolling subjects with a clinical diagnosis of EGW, and used specialized microarrays to determine the expression-level changes specific to apoptosis of EGW before and after sinecatechins treatment. A total of 30 subjects were recruited for the study, 24 male and 6 female, with a mean age of 39.2 – 10.6 years. Of these, 18 subjects remained enrolled and were available for follow-up for the duration of the study. Veregen ointment, 15%, was dispensed to the patient with instructions to apply to the target warts three times daily for 16 weeks. Three biopsies were taken from each patient—excised at baseline (B1), at the first visit with 50% or more clearance of target warts (B2), and at the first visit with complete clearance of target lesions (B3). Tissue samples were stored in RNAlater (Ambion) solution until processing, and nucleic acids were extracted from the samples using Trizol reagent (Sigma). HPV types from extracted DNA samples were detected by a nested polymerase chain reaction (PCR) approach as previously described (1), and copy number was determined with a custom-made real time PCR kit (Quantification of HPV6_15979, L1 protein, L1 gene, PrimerDesign Ltd.). Extracted and applied RNA, measured at A260/A280 nm, produced a ratio between 1.8 and 2.0. Subjects were stratified based on their response to treatment, which was quantitatively determined by measuring change in viral copy number between B1 and B3. Subjects were classified as virological responders (VR) if viral copy number decreased by at least 60% from B1, and were classified as virological nonresponders (VNR) if viral copy number remained the same or increased from B1. Of these, seven were found to be VR, and 11 were defined as VNR. In addition to the detection of HPV-6 in all lesions, one VR and three VNR were positive for co-infection with other HPV types (VR: HPV-18 and -35; VNR: HPV-7, -8, and -35). Next, the Applied Biosystems High Capacity RNAto-cDNA master mix was utilized for cDNA synthesis, and analysis of apoptotic gene expressions was then performed using TaqMan array 96-well plates. Initially, gene expression level was surveyed individually as an independent variable, and subsequently, group-based response values were generated using DataAssist v3.01 Software. Quantification of group-based responses for each gene were determined by calculating a fold change from biopsy 1 to biopsy 2 (B1_2), from biopsy 1 to biopsy 3 (B1_3), and from biopsy 2 to biopsy 3 (B2_3). Gene expression changes were categorized as biologically significant if there was at least a twofold change. To determine statistical significance of these fold changes, the statistical significance of these fold changes was evaluated using a nonparametric two-sided Wilcoxon signed-rank test with a significance level of p< 0.05.

Future considerations for clinical dermatology in the setting of 21st century American policy reform: Accountable Care Organizations

An Accountable Care Organization (ACO) is a network of providers that collaborates to manage care and is financially incentivized to realize cost savings while also optimizing standards of care. Since its introduction as part of the 2010 Patient Protection and Affordable Care Act, ACOs have grown to include 16% of Medicare beneficiaries and currently represent Medicares largest payment initiative. Although ACOs are still in the pilot phase with multiple structural models being assessed, incentives are being introduced to encourage specialist participation, and dermatologists will have the opportunity to influence both the cost savings and quality standard aspects of these organizations. In this article, part of a health care policy series targeted to dermatologists, we review what an ACO is, its relevance to dermatologists, and essential factors to consider when joining and negotiating with an ACO.

Molecular mechanisms supporting a pathogenic role for human polyomavirus 6 small T antigen: Protein phosphatase 2A targeting and MAPK cascade activation

BRAF inhibitors are highly effective therapies in treating a subset of melanomas but are associated with induction of secondary cutaneous squamous cell carcinoma (cSCC). Recently, Human Polyomavirus 6 (HPyV6) was found to actively express viral proteins in BRAF inhibitor‐induced cSCCs; however, the specific cellular mechanisms by which HPyV6 may facilitate neoplastic cell growth require further investigation. The current study describes a novel pathogenic mechanism of action for HPyV6 small tumor (sT) antigen which involves binding to protein phosphatase 2A (PP2A) via its WFG motif and zinc binding sites. Our findings demonstrate an important role of HPyV6 sT for activation of PP2As downstream oncogenic pathways (MEK/ERK/c‐Jun), which may underlie the pathogenesis of BRAF inhibitor‐induced neoplasms. J. Med. Virol. 89:742–747, 2017.

Future considerations for clinical dermatology in the setting of 21st century American policy reform: The Medicare Access and Children's Health Insurance Program Reauthorization Act and Alternative Payment Models in dermatology

With the introduction of the Medicare Access and Childrens Health Insurance Program Reauthorization Act, clinicians who are not eligible for an exemption must choose to participate in 1 of 2 new reimbursement models: the Merit-based Incentive Payment System or Alternative Payment Models (APMs). Although most dermatologists are expected to default into the Merit-based Incentive Payment System, some may have an interest in exploring APMs, which have associated financial incentives. However, for dermatologists interested in the APM pathway, there are currently no options other than joining a qualifying Accountable Care Organization, which make up only a small subset of Accountable Care Organizations overall. As a result, additional APMs relevant to dermatologists are needed to allow those interested in the APMs to explore this pathway. Fortunately, the Medicare Access and Childrens Health Insurance Program Reauthorization Act establishes a process for new APMs to be approved and the creation of bundled payments for skin diseases may represent an opportunity to increase the number of APMs available to dermatologists. In this article, we will provide a detailed review of APMs under the Medicare Access and Childrens Health Insurance Program Reauthorization Act and discuss the development and introduction of APMs as they pertain to dermatology.

Future considerations for clinical dermatology in the setting of 21st century American policy reform: The Medicare Access and Children's Health Insurance Program Reauthorization Act and the Merit-based Incentive Payment System

As the implementation of the Medicare Access and Childrens Health Insurance Program Reauthorization Act begins, many dermatologists who provide Medicare Part B services will be subject to the reporting requirements of the Merit-based Incentive Payment System (MIPS). Clinicians subject to MIPS will receive a composite score based on performance across 4 categories: quality, advancing care information, improvement activities, and cost. Depending on their overall MIPS score, clinicians will be eligible for a positive or negative payment adjustment. Quality will replace the Physician Quality Reporting System and clinicians will report on 6 measures from a list of over 250 options. Advancing care information will replace meaningful use and will assess clinicians on activities related to integration of electronic health record technology into their practice. Improvement activities will require clinicians to attest to completion of activities focused on improvements in care coordination, beneficiary engagement, and patient safety. Finally, cost will be determined automatically from Medicare claims data. In this article, we will provide a detailed review of the Medicare Access and Childrens Health Insurance Program Reauthorization Act with a focus on MIPS and briefly discuss the potential implications for dermatologists.

Molecular insight into the viral biology and clinical features of trichodysplasia spinulosa

Trichodysplasia spinulosa (TS) is a disfiguring skin disease that occurs most frequently in patients receiving immunosuppressive therapies, and is thus frequently associated with organ transplantation. TS is characterized clinically by folliculocentric papular eruption, keratin spine formation and development of leonine face; and histologically by expansion of the inner root sheath epithelium and high expression of the proliferative marker Ki‐67. Recent discovery of the TS‐associated polyomavirus (TSPyV) and emerging studies demonstrating the role of TSPyV tumour antigens in cell proliferation pathways have opened a new corridor for research on TS. In this brief review, we summarize the clinical and histological features of TS and evaluate the current options for therapy. Furthermore, we address the viral aetiology of the disease and explore the mechanisms by which TSPyV may influence TS development and progression. As reports of TS continue to rise, clinician recognition of TS, as well as accompanying research on its underlying pathogenesis and therapeutic options, is becoming increasingly important. It is our hope that heightened clinical suspicion for TS will increase rates of diagnosis and will galvanize both molecular and clinical interest in this disease.

Expression Patterns of Immune-Associated Genes in External Genital and Perianal Warts Treated with Sinecatechins

The role of human papillomavirus (HPV) in human disease includes external genital and perianal warts (EGW), with some HPV genotypes having oncogenic potential (i.e., HPV-16 and -18). While green-tea extracts have antitumor and antiproliferative effects in vitro, the mechanism of action of sinecatechins in the treatment of EGW is not well understood. To investigate the role of immune-regulated genes further, an open-label, single institution, prospective study was conducted enrolling patients with clinically diagnosed EGW. Thirty subjects were enrolled, and 18 completed the trial. All patients applied sinecatechins 15% ointment to target lesions in the study. RNA expression microarrays were obtained from treated EGW lesions and analyzed for differential gene expression of immune-regulated genes. HPV types were analyzed and, based on copy number, were stratified into virological responders (VR) or nonresponders (VNR). Gene expression analysis of RNA samples was performed using TaqMan arrays for human T cell receptor and CD3 complex (TCR), Toll-like receptors (TLR) pathway, interferon (IFN) pathway, and antigen processing pathway. A total of 256 genes were analyzed across the four arrays. Genes that were significantly regulated between VRs and VNRs were CREB3L4, HIST1H3A, HIST1H3H, IFNA1, IFNA4, IFNA5, IFNA6, IFNA8, IFNA14, IFNG, IFNAR1, IL6, IRF9, MAPK4, MAPK5, MAPK14, NET1, and PIK3C2A in the IFN array. In the TCR array, HLA_B was found to be statistically significantly upregulated in both the VR and VNR groups; concomitantly, CD8A was found to be statistically significantly downregulated only in VRs. In the TLR array, only LBP and MAPK8 were found to be differentially regulated. In the antigen processing array, HLA-A, HLA-C, HLA-DMA, HLA-DMB, HLA-F, PSMA5, PSMB8, and PSMB9 were differentially downregulated. Based on these findings, it was determined that sinecatechins treatment modulates and downregulates genes involved in the pro-inflammatory response to HPV infection.

Beta-blockers as therapy for infantile hemangiomas.

Infantile hemangiomas (IH) are common benign vascular tumors seen in children. Although the majority will improve spontaneously without treatment, a small subset will require therapy due to a variety of complications. Less than a decade ago, propranolol replaced corticosteroids as first-line treatment for most IH and it has proven to be a relatively safe, effective therapy. After initiation of propranolol, most hemangiomas show evidence of significant improvement relatively rapidly, often within days. Although propranolol is generally felt to have a more limited side-effect profile than systemic corticosteroids, its use has been infrequently associated with adverse events, including sleep disturbances, acrocyanosis, hypotension, bradycardia, respiratory events, and hypoglycemia. Rarely, hypoglycemic seizures have been reported, usually occurring in the setting of prolonged fasting.

Commentary: Future considerations for clinical dermatology in the setting of 21st century American policy reform: The Medicare Access and CHIP Reauthorization Act of 2015

The American Medical Association and over 750 national and state-based physician and specialty organizations have gone on record in support of H.R. 2, the “Medicare Access and CHIP Reauthorization Act.” Many physicians have questions about the major provisions of the legislation, and others have been disturbed by incomplete or incorrect interpretations of the bill’s legislative language. Below are responses to frequently asked questions about the major provisions of H.R. 2 that will affect Medicare physician payments; following these FAQs are Myth-Fact clarifications to incorrect interpretations of the bill that have been widely circulated.