Search

Pyoderma gangrenosum (PG) can represent a diagnostic challenge, leading to missed or delayed diagnosis. With prolonged immunosuppressive therapy, the risk of infections is elevated, predisposing patients to receive anti-infective treatments and, in serious cases, amputations. Limb amputations have been reported as complication of PG misdiagnosis but can also occur as a complication of long-standing PG ulcers.We aimed to describe the clinical characteristics of patients with PG leading to limb amputation through a multicenter retrospective case series between 2010 and 2020 including patients with PG who underwent limb amputation. We report a descriptive analysis of these patients' clinical course and outcome.Ten patients with PG who underwent at least one limb amputation were identified. Six were male (60%). Mean age was 65 years. All patients had ulcerative PG on the lower extremities, with a mean PG ulcer duration of 30.6 months. Six patients had PG-related comorbidities such as ulcerative colitis, myelodysplasia, and inflammatory arthritis. Other significant comorbidities included diabetes mellitus (DM) (five patients), coronary artery disease (five patients), and chronic kidney disease (two patients). The majority of patients (8/10) were correctly diagnosed with PG prior to amputation, whereas two patients were misdiagnosed with necrotizing soft tissue infections (NSTIs). All patients received intravenous antibiotics without substantial improvement. Eight patients developed sepsis and shock-like symptoms and the diagnosis of NSTIs was considered. Below-knee amputation was performed in six patients and above-knee amputation in four. Four patients had amputation performed twice because of recurrent NSTIs. Conclusion This multicenter case series sheds light on practice gaps for physician assessing patients with PG, in that limb amputation may result from PG misdiagnosis or complications thereof. Elderly patients (above 65 years) with coexisting lower extremity PG, DM, and/or chronic cardiac or renal disease should be managed with particular care toward preventing infection/NSTIs to prevent further complications such as limb amputations.

Introduction To evaluate the use of inaccurate terminology used by dermatology practices to describe the training and qualifications of their nonphysician clinicians (NPCs) when new patients are booking appointments. Methods Clinics were randomly selected and called to determine the first available appointment for a new patient with a new and changing mole. If the receptionist confirmed the first-offered appointment was with an NPC, the encounter was included in this study. If receptionists used inaccurate terminology to describe the NPCs and their qualifications, this instance was recorded along with the specific language that they used. Results A total of 344 unique dermatology clinics were contacted on February 27, 2020, in 25 states. Phone calls at 128 clinics (37.2%) met our inclusion criterion. Inaccurate language was used to describe NPCs at 23 (18%) unique clinic locations across 12 states, with "dermatologist," "doctor," "physician," and "board-certified" being used to describe NPCs as the most common inaccurate terms. Conclusion These findings demonstrate that front office staff at dermatology clinics use inaccurate and potentially misleading terminology to refer to NPCs working in their clinics. While we cannot establish whether this is intentional or due to a lack of training, additional focus should be placed on accurately representing provider qualifications to patients.

Human melanomas are commonly driven by activating mutations in BRAF, which promote melanocyte proliferation through constitutive stimulation of the MAPK pathway. However, oncogenic BRAF alone is insufficient to promote melanoma; instead, its expression merely induces a transient burst of proliferation that ultimately ceases with the development of benign nevi (i.e. moles) comprised of growth-arrested melanocytes. The tumor suppressive mechanisms that induce this melanocytic growth arrest remain poorly understood. Recent modeling studies have suggested that the growth arrest of nevus melanocytes is not solely due to oncogene activation in individual cells, but rather due to cells sensing and responding to their collective overgrowth, similar to what occurs in normal tissues. This cell growth arrest is reminiscent of the arrest induced by activation of the Hippo tumor suppressor pathway, which is an evolutionarily conserved pathway known to regulate organ size. Herein, we demonstrate that oncogenic BRAF signaling activates the Hippo pathway in vitro, which leads to inhibition of the pro-growth transcriptional co-activators YAP and TAZ, ultimately promoting the growth arrest of melanocytes. We also provide evidence that the Hippo tumor suppressor pathway is activated in growth-arrested nevus melanocytes in vivo, both from single-cell sequencing of mouse models of nevogenesis and human tissue samples. Mechanistically, we observe that oncogenic BRAF promotes both ERK-dependent alterations in the actin cytoskeleton and whole-genome-doubling events, and that these two effects independently promote Hippo pathway activation. Lastly, we demonstrate that abrogation of the Hippo pathway, via melanocyte-specific deletion of the Hippo kinases Lats1/2, enables oncogenic BRAF-expressing melanocytes to bypass nevus formation, thus leading to the rapid onset of melanoma with 100% penetrance. This model is clinically relevant, as co-heterozygous loss of LATS1/2 is observed in ∼15% of human melanomas. Collectively, our data reveal that the Hippo pathway enforces the stable growth arrest of nevus melanocytes and therefore represents a critical and previously unappreciated barrier to melanoma development.

Background: Variation in seed oil composition and content among soybean varieties is largely attributed to differences in transcript sequences and/or transcript accumulation of oil production related genes in seeds. Discovery and analysis of sequence and expression variations in these genes will accelerate soybean oil quality improvement. Results: In an effort to identify these variations, we sequenced the transcriptomes of soybean seeds from nine lines varying in oil composition and/or total oil content. Our results showed that 69,338 distinct transcripts from 32,885 annotated genes were expressed in seeds. A total of 8,037 transcript expression polymorphisms and 50,485 transcript sequence polymorphisms (48,792 SNPs and 1,693 small Indels) were identified among the lines. Effects of the transcript polymorphisms on their encoded protein sequences and functions were predicted. The studies also provided independent evidence that the lack of FAD2-1A gene activity and a non-synonymous SNP in the coding sequence of FAB2C caused elevated oleic acid and stearic acid levels in soybean lines M23 and FAM94-41, respectively. Conclusions: As a proof-of-concept, we developed an integrated RNA-seq and bioinformatics approach to identify and functionally annotate transcript polymorphisms, and demonstrated its high effectiveness for discovery of genetic and transcript variations that result in altered oil quality traits. The collection of transcript polymorphisms coupled with their predicted functional effects will be a valuable asset for further discovery of genes, gene variants, and functional markers to improve soybean oil quality.