Primary Skin Research Articles

Imperatorin Positively Regulates Melanogenesis through Signaling Pathways Involving PKA/CREB, ERK, AKT, and GSK3β/β-Catenin.

The present study investigated the melanogenic effects of imperatorin and isoimperatorin and the underlying mechanisms of imperatorin using a mouse melanoma B16F10 model. Interestingly, treatment with 25 μM of either imperatorin or isoimperatorin, despite their structural differences, did not produce differences in melanin content and intracellular tyrosinase activity. Imperatorin also activated the expression of melanogenic enzymes, such as tyrosinase (TYR) and tyrosinase-related proteins TYRP-1 and TYRP-2. Mechanistically, imperatorin increases melanin synthesis through the cyclic adenosine monophosphate (cAMP)-dependent protein kinase (PKA)/cAMP-responsive element-binding protein (CREB)-dependent upregulation of microphthalmia-associated transcription factor (MITF), which is a key transcription factor in melanogenesis. Furthermore, imperatorin exerted melanogenic effects by downregulating extracellular signal-regulated kinase (ERK) and upregulating phosphatidylinositol 3 kinase (PI3K)/protein kinase B (AKT)/glycogen synthesis kinase-3β (GSK-3β). Moreover, imperatorin increased the content of β-catenin in the cell cytoplasm and nucleus by reducing the content of phosphorylated β-catenin (p-β-catenin). Finally, we tested the potential of imperatorin in topical application through primary human skin irritation tests. These tests were performed on the normal skin (upper back) of 31 volunteers to determine whether 25 or 50 µM of imperatorin had irritation or sensitization potential. During these tests, imperatorin did not induce any adverse reactions. Taken together, these findings suggest that the regulation of melanogenesis by imperatorin can be mediated by signaling pathways involving PKA/CREB, ERK, AKT, and GSK3β/β-catenin and that imperatorin could prevent the pathogenesis of pigmentation diseases when used as a topical agent.

Healing of ExcisionAl wounds on Lower legs by Secondary intention (HEALS) cohort study. Part 1: a multicentre prospective observational cohort study in patients without planned compression.

There is no agreed treatment pathway following excision of keratinocyte cancer (KC). Compression therapy is considered beneficial for secondary intention healing on the lower leg; however, there is a lack of supportive evidence. To plan a randomized controlled trial (RCT), suitable data are needed. We report a multicentre prospective observational cohort study in this patient population with the intention of informing a future trial design. To estimate the time to healing in wounds healing by secondary intention without planned postoperative compression, following excision of KC on the lower leg; to characterize the patient population, including factors affecting healing; and to assess the incidence of complications. This was a multicentre prospective observational cohort study. Inclusion criteria were age ≥ 18 years with planned excision of KC on the lower leg and healing by secondary intention, an ankle-brachial pressure index (ABPI) of ≥ 0.8; and written informed consent. Exclusion criteria included planned excision with primary closure, skin graft or flap; compression therapy for another indication; planned compression; inability of patient to receive, comply with or tolerate high compression; or a suspected diagnosis other than KC. This study recruited 58 patients from 9 secondary care dermatology clinics. In the analysis population (n = 53), mean age was 81 years (range 25-97 years), median time to healing was 81 days (95% CI 73-92) and 45 patients (84.9%) had healing of the wound at the 6-month follow-up. The healing prognostic factors were wound parameters and ABPI. Wound infections occurred in 16 participants (30.2%). Four patients (7.5%) were admitted to hospital; three because of an infection and one because of a fall. The collected data have informed the RCT preparation. A relatively high proportion (7.5-15%) of unhealed wounds, infection and hospital admissions demonstrate the need for clearly establishing potentially effective treatments to improve outcomes for this population.

S1998 Colonic Merkel Cell Carcinoma of Unknown Primary: Small Cell Carcinoma Outside the Usual

Introduction: Merkel cell carcinoma (MCC) is a rare neuroendocrine skin carcinoma with documented metastases to the liver, lungs, and gastrointestinal (GI) tract. Colonic metastases are rare but seen with recurrent or primary cutaneous lesions. Described is a patient who presented with bowel obstruction with a hepatic flexure MCC of unknown primary (MCCUP). Case Description/Methods: A 69-year-old female with a history of breast, lung, and anal cancer presented to the emergency department with abdominal pain and distension. Computed tomography of her abdomen demonstrated dilated loops of small bowel and a partial obstruction with transition point in the hepatic flexure. Colonoscopy demonstrated a 4 cm mass at the hepatic flexure obstructing the lumen. Biopsy revealed a high-grade neuroendocrine carcinoma. A right colectomy and histopathology confirmed small cell neuroendocrine carcinoma involving the colonic wall into the pericolic adipose tissue with nodal involvement. It was positive on cytokeratin CAM 5.2, synaptophysin, and Merkel cell polyomavirus (MCPvY) and negative on CDX-2 and TTF-1, excluding primary bowel or lung small cell carcinomas, respectively. Dermatologic evaluation did not reveal a primary cutaneous lesion. Genetic testing was unremarkable. Discussion: This is the first case of MCCUP presenting with colonic obstruction; prior described cases of MCC metastatic to the colon were recurrent disease or from primary skin lesions. Because MCC is rare, has non-specific symptoms, and may lack a primary lesion, MCCUP must be distinguished from other small round blue cell malignancies more commonly found in the GI tract. Thus, neuroendocrine, keratin and MCPyV ancillary staining are critical to distinguish MCC from B-cell lymphoma, small cell carcinoma of bowel or lung primary, and other metastatic dermal malignancies. MCPyV testing in the absence of prior diagnosis is uncommon but vital to the workup of neuroendocrine carcinomas when CDX-2 and TTF-1 are negative as MCPyV positive lymph nodes predict worse outcomes such as disease-free survival. In this patient immunosuppression and prior radiation increased the risk of MCC, and even suggest that this might be a colonic primary. Rarely, MCC and MCCUP are root causes of neuroendocrine carcinomas of the GI tract. In immunocompromised patients, biopsy and pathologic staining are necessary to distinguish insidious malignancies. MCPyV analysis is helpful for diagnosing MCCUP and informing its prognosis.

Inhibition of Complex I of the Respiratory Chain, but Not Complex III, Attenuates Degranulation and Cytokine Secretion in Human Skin Mast Cells

The mechanisms of mast cell (MC) degranulation and MC-driven skin symptoms are well-described. In contrast, data about the role of mitochondrial respiration for immune functions of human skin MCs are lacking. Oxygen consumption rate (OCR) in primary human skin MCs during IgE-mediated activation in the absence of glucose was examined using a metabolic flux analyzer. Effects of the inhibition of mitochondrial complex I (by rotenone A) and III (by myxothiazol) on degranulation and cytokine secretion (IL-4, IL-5, IL-6, IL-13, TNF-α, and GM-CSF) were explored by the β-hexosaminidase release assay and multiplex ELISA. IgE-mediated activation rapidly increased the mitochondrial OCR and extracellular acidification; the contribution of non-mitochondrial oxygen consumption remained unchanged at lower levels. Both myxothiazol and rotenone A reduced OCR, the mitochondrial parameters, and extracellular acidification; however, myxothiazol did not affect degranulation and cytokine secretion. In contrast, degranulation and the secretion of IL-6, IL-13, TNF-α, and GM-CSF were reduced by rotenone A, whereas the secretion of IL-4 and IL-5 was not significantly affected. The inhibitors did not affect cell viability. Our results highlight the important role played by mitochondrial respiration in primary human skin MCs and allow for a conclusion on a hierarchy of their effector functions. Drugs targeting specific pathways in mitochondria may provide future options to control MC-driven skin symptoms.

Standardized self-management education of psoriasis patients under New Coronavirus Pneumonia

Since the outbreak of novel coronavirus pneumonia (COVID-19) in December 2019, the epidemic has also had an adverse impact on the mental health of the public due to fear of the epidemic, common diseases, treatment delays and other factors. Patients with chronic skin diseases often have problems such as stress, anxiety, depression, anger and social isolation, which in turn will induce or aggravate primary skin diseases and form a vicious circle. Psoriasis is one of the common skin diseases. When the skin barrier function of patients with psoriasis is damaged, improper protection will increase the susceptibility to virus and induce or aggravate the disease. During the COVID-19 epidemic, some psoriasis patients who were isolated at home suffered from illness due to lack of disease awareness, poor self-management and lack. Patients who go out for medical treatment will increase the risk of COVID-19 infection. The lack of standardized self-management of psoriasis patients is one of the important reasons for the recurrence of their diseases. Standardized self-management is an important guarantee to improve the health status of patients and improve their quality of life. This article expounds the current situation and contents of standardized self-management of psoriasis patients, hoping to arouse medical workers' Thinking on how to implement standardized self-management of psoriasis patients under the epidemic situation of novel coronavirus pneumonia. At the same time, patients should strengthen self-management and do a good job in going out to prevent and minimize the adverse effects of the epidemic situation.

The impact of skin cancer prevention efforts in New South Wales, Australia: Generational trends in melanoma incidence and mortality

BackgroundIn Australia, skin cancer awareness campaigns have focused on raising the awareness and consequences of skin cancer and highlighting the importance of utilising sun protection. MethodsTrends in melanoma incidence and mortality have been explored elsewhere in Australia and this study sought to examine the trends in NSW. Anonymised incidence and mortality data for in situ and invasive melanoma from 1988 to 2014 were obtained from the NSW Cancer Registry. Trends of melanoma incidence and mortality were analysed using segmented regression to allow for changes over time. Birth cohort patterns were assessed using age–period–cohort models. ResultsOver the period, incidence of in situ melanoma increased in all age groups although the rates were lowest in those under 40 years of age. Incidence of invasive melanoma was either stable or decreased in people under 60, while it increased in those aged 60 and above, particularly in men. Age–period–cohort analysis revealed decreasing age-specific incidence of invasive melanoma under 40 years of age. Melanoma mortality over the period was stable or decreased in all groups except in men aged 60 or over. Overall, mortality rates generally declined or remained stable particularly in recent years. ConclusionIt is encouraging that rates of invasive melanoma are declining in the younger age cohorts – which could be attributed to both primary prevention efforts with individuals protecting their skin as well as early detection through self assessment and clinician performed skin checks. In addition, whilst it is important to monitor the increasing rates of in situ melanoma, the increase is likely due to early detection and treatment of melanoma that could have progressed to invasive melanoma and therefore detection whilst still in situ is an improved outcome. Overall, the results demonstrate the need to continue to improve the understanding of and compliance with primary skin cancer prevention measures in order to reduce population UVR exposure and overall melanoma incidence.

Therapeutic Effect of Bee Venom and Melittin on Skin Infection Caused by Streptococcus pyogenes.

Streptococcus pyogenes (S. pyogenes) bacteria cause almost all primary skin infections in humans. Bee venom (BV) and melittin (Mel) have multiple effects, including antibacterial and anti-inflammatory activities. This study aims to demonstrate their effects on bacterial mouse skin infection using S. pyogenes. The dorsal skin was tape-stripped, then S. pyogenes was topically applied. BV or Mel were topically applied to the lesion. The tissues were stained with hematoxylin and eosin, while immunohistochemical staining was performed with anti-neutrophil. S. pyogenes-infected skin revealed increased epidermal and dermal layers, but it was reduced in the BV and Mel groups. Finding increased neutrophils in the mice infected with S. pyogenes, but the BV and Mel mice showed decreased expression. These results suggest that BV and Mel treatments could reduce the inflammatory reactions and help improve lesions induced by S. pyogenes skin infection. This study provides additional assessment of the potential therapeutic effects of BV and Mel in managing skin infection caused by S. pyogenes, further suggesting that it could be a candidate for developing novel treatment alternative for streptococcal skin infections.

Atrazine modifies markers of melanocyte maturation and apoptosis in primary skin cultures

Atrazine (ATZ) is part of a group of herbicides called triazines. ATZ is widely used in agricultural areas of Mexico, commonly used for the selective control of weeds in corn and sorghum crops. The exposure to ATZ can have serious human health effects since its use was associated with the development of cutaneous melanoma in an epidemiological study. The aim of this study was to evaluate the expression of maturation and apoptotic markers in primary skin cultures exposed to ATZ. The primary skin cultures were exposed to 0.1, and 10 µM ATZ with or without ultraviolet (UV) radiation and the expression of maturation and apoptotic markers were evaluated by RT-qPCR. We observed a significant increase in all the melanocyte maturation markers in cells exposed to ATZ with or without UV, with SOX-9 and FAK (melanoblast markers) being the highest. Also, the expression of BCL-2 (anti-apoptotic marker) was the most increased gene in cells exposed to ATZ with or without UV. Low concentrations of ATZ and UV radiation induce genetic changes associated with the development of immature melanocytes and activate mechanisms associated with the inhibition of apoptosis characteristics of malignant cell transformation, which will allow proposing new therapeutic targets and generating new restrictions or care in farmers exposed to pesticides such as the ATZ.

Primary intraosseous Rosai-Dorfman disease: An analysis of clinicopathologic characteristics, molecular genetics, and prognostic features.

BackgroundRosai–Dorfman disease (RDD) is a rare histiocytic proliferative disorder of uncertain pathogenesis. Most patients present with proliferation in the lymph nodes manifesting as adenopathy; however, RDD may primarily arise in a variety of extranodal sites, including the bone, which is a great challenge in the diagnosis. The clinicopathological characteristics and prognostic features of primary intraosseous RDD have not been well characterized.MethodsWe retrospectively analyzed the clinicopathologic and prognostic features of four cases of primary intraosseous RDD during the past 10 years in our hospital, with a review of an additional 62 cases with complete follow-up data from the literature.ResultsPrimary intraosseous RDD was identified in 0.14% (4/2,800) of total bone biopsies performed at our institution over the study period. According to our retrospective analysis, a total of 18 cases of primary lymph node, skin, or other non-osseous site-based RDD were diagnosed in our hospital. The ages of the 66 total patients ranged from 1.5 to 76 years, with a median age of 25 years. There were 31 male and 35 female patients, with a male-to-female ratio of 0.89:1. Primary intraosseous RDD occurred most often in the bones of the extremities (60.6%, 40/66), with the proximal tibia being the most common location; 39.4% (26/66) of the cases arose in the axial skeleton, predominantly in the vertebra and craniofacial bones. Solitary masses and multiple tumors were present in 84.8% (56/66) and 15.2% (10/66) of the cases, respectively. Pain of the affected area was the most common presenting symptom. Radiographically, the lesions were lytic with well-defined and usually sclerotic margins. Immunohistochemistry showed that large histiocytes from patients with RDD were positive for OCT2, in addition to S100 and CD68. Molecular tests were performed in seven reported cases and four of our cases. All the 11 cases were non-decalcified. PCR results showed that there were no BRAF-V600E, KRAS, or NRAS mutations in primary intraosseous RDD; only one case with both RDD and Langerhans cell histiocytosis showed BRAF-V600E mutation. The survival data showed that 22.7% (15/66) of the patients experienced recurrences or developed RDD at distant sites during the follow-up period (median follow-up, 13 months; range, 1–106 months). The 5-year progression-free survival (PFS) of the patients with primary intraosseous RDD was 57.5%. We found that there was a significant difference in PFS between female and male patients (p = 0.031). However, there was no statistically significant difference in PFS between patients with solitary masses and multiple tumors (p = 0.698). Similarly, no statistically significant differences in PFS were found between the different age groups (p = 0.908) or tumor locations (p = 0.728).ConclusionPrimary intraosseous RDD is an extremely rare disease. The diagnosis of RDD may be quite challenging because of its non-specific clinical presentation and imaging. Immunohistochemistry showed that large histiocytes were positive for OCT2 in addition to S100 and CD68, which may be helpful for differential diagnosis. Molecular detection showed that RDD may be related to the MAPK pathway, though these results are also ultimately not specific. The pathogenesis of RDD is yet to be elucidated, but recent studies suggest possible clonality of hyperproliferative histiocytes.

Effects of PB-TURSO on the transcriptional and metabolic landscape of sporadic ALS fibroblasts.

ObjectiveALS is a rapidly progressive, fatal disorder caused by motor neuron degeneration, for which there is a great unmet therapeutic need. AMX0035, a combination of sodium phenylbutyrate (PB) and taurursodiol (TUDCA, TURSO), has shown promising results in early ALS clinical trials, but its mechanisms of action remain to be elucidated. Therefore, our goal was to obtain an unbiased landscape of the molecular effects of AMX0035 in ALS patient‐derived cells.MethodsWe investigated the transcriptomic and metabolomic profiles of primary skin fibroblasts from sporadic ALS patients and healthy controls (n = 12/group) treated with PB, TUDCA, or PB–TUDCA combination (Combo). Data were evaluated with multiple approaches including differential gene expression and metabolite abundance, Gene Ontology and metabolic pathway analysis, weighted gene co‐expression correlation analysis (WGCNA), and combined multiomics integrated analysis.ResultsCombo changed many more genes and metabolites than either PB or TUDCA individually. Most changes were unique to Combo and affected the expression of genes involved in nucleocytoplasmic transport, unfolded protein response, mitochondrial function, RNA metabolism, and innate immunity. WGCNA showed significant correlations between ALS gene expression modules and clinical parameters that were abolished by Combo treatment.InterpretationThis study is the first to explore the molecular effects of Combo in ALS patient‐derived cells. It shows that Combo has a greater and distinct impact compared with the individual compounds and provides clues to drug targets and mechanisms of action, which may underlie the benefits of this investigational drug combination.

Clinical Impact of Two-Week Placement of a Subcutaneous Suction Drain in Preventing Incisional Surgical Site Infection in Open Gastrointestinal Surgery with Class 4 Dirty Wound: A Retrospective Study.

Background: Two recent randomized controlled trials demonstrated the beneficial effects of subcutaneous drainage in preventing incisional surgical site infection (SSI) in colorectal surgery. This study aimed to evaluate the efficacy of subcutaneous suction drains (SSDs) compared with primary skin closure (PC) in class 4 dirty wound surgery. Patients and Methods: Eighty-one patients undergoing open gastrointestinal surgery with class 4 dirty wounds were enrolled in this study, 30 of whom underwent SSD insertion, whereas the other 51 were treated with PC. Because several studies have reported that the median onset of the development of incisional SSI was eight to 13 days after surgery, we used a two-week placement of an SSD. Comparison of patients treated with SSD and PC and multivariable analysis were performed to test the ability of SSD in decreasing the SSI rate. Results: No differences were observed between the two groups in terms of gender, body mass index, American Society of Anesthesiology score, steroid use, presence of diabetes mellitus, peri-operative transfusion, and surgery type. Surgical site infection incidence was lower in the SSD group (6.6%; 2/30) than that in the PC group (23.5%; 12/51; p = 0.069). Multivariable analysis revealed that the presence of diabetes mellitus was an important independent risk factor for incisional SSI, and the placement of an SSD has substantial preventive effects on incisional SSI (p = 0.018 and p = 0.014, respectively). Conclusions: This study suggested the potential importance of a two-week placement of an SSD for preventing incisional SSI in class 4 dirty wound surgery.

Transforming Growth Factor-β Receptor–Mediated, p38 Mitogen-Activated Protein Kinase–Dependent Signaling Drives Enhanced Myofibroblast Differentiation during Skin Wound Healing in Mice Lacking Hyaluronan Synthases 1 and 3

Normal myofibroblast differentiation is critical for proper skin wound healing. Neoexpression of α-smooth muscle actin (α-SMA), a marker for myofibroblast differentiation, is driven by transforming growth factor (TGF)-β receptor-mediated signaling. Hyaluronan and its three synthesizing enzymes, hyaluronan synthases (Has 1, 2, and 3), also participate in this process. Closure of skin wounds is significantly accelerated in Has1/3 double-knockout (Has1/3-null) mice. Herein, TGF-β activity and dermal collagen maturation were increased in Has1/3-null healing skin. Cultures of primary skin fibroblasts isolated from Has1/3-null mice had higher levels of TGF-β activity, α-SMA expression, and phosphorylation of p38 mitogen-activated protein kinase at Thr180/Tyr182, compared with wild-type fibroblasts. p38α mitogen-activated protein kinase was a necessary element in a noncanonical TGF-β receptor signaling pathway driving α-SMA expression in Has1/3-null fibroblasts. Myocardin-related transcription factor (MRTF), a cofactor that binds to the transcription factor serum response factor (SRF), was also critical. Nuclear localization of MRTF was increased, and MRTF binding to SRF was enhanced in Has1/3-null fibroblasts. Inhibition of MRTF or SRF expression by RNA interference suppresses α-SMA expression at baseline and diminished its overexpression in Has1/3-null fibroblasts. Interestingly, total matrix metalloproteinase activity was increased in healing skin and fibroblasts from Has1/3-null mice, possibly explaining the increased TGF-β activation.

34982 Transcriptome analysis reveals intrinsic proinflammatory signaling in healthy African American skin

Background: The disparities in prevalence and clinical features for many inflammatory skin diseases including atopic dermatitis and psoriasis are well recognized; however, the underlying mechanisms are largely unknown. Methods: Using bulk RNA-seq analysis, we compared the baseline gene expression in upper arm full thickness skin biopsies from 17 healthy individuals self-reporting as African American (AA) or White non-Hispanic (WNH) and in 3D human skin equivalents (HSE) made from AA and WNH primary skin keratinocytes. Results: Extensively validated RNA-Seq analysis identified 570 differentially expressed genes (DEG) in AA skin including immunoglobulins and their receptors such as FCER1G; proinflammatory genes such as TNFα, IL-32; EDC (epidermal differentiation cluster) and keratin genes. DEGs were functionally enriched for inflammatory responses, keratinization, cornified envelope formation. RNA-seq analysis of gene expression in AA versus WNH HSEs revealed 360 DEGs (some shared with skin) which were enriched by similar to skin functions. In addition, AA HSE appeared more responsive to TNFα proinflammatory effects. Finally, AA-specific DEGs in skin and HSE significantly overlapped with molecular signatures of lesional skin in AD and psoriasis patients. Interestingly, AA skin DEGs overlapping with AD molecular signature in skin were enriched by IL13 and IL4 signaling central for AD. Conclusions: Overall, these findings suggest the existence of intrinsic proinflammatory circuits in AA keratinocytes/skin that may account for disease disparities and will help to build a foundation for the development of targeted skin disease prevention and treatment.

Ionic liquid-mediated delivery of a BCL-2 inhibitor for topical treatment of skin melanoma.

Skin melanoma is one of the most common cancer types in the United States and worldwide, and its incidence continues to grow. Primary skin melanoma can be removed surgically when feasible and if detected at an early stage. Anti-cancer drugs can be applied topically to treat skin cancer lesions and used as an adjunct to surgery to prevent the recurrence of tumor growth. We developed a topical formulation composed of Navitoclax (NAVI), a BCL-2 inhibitor that results in apoptosis, and an ionic liquid of choline octanoate (COA) to treat early-stage melanoma. NAVI is a small hydrophobic molecule that solubilizes at 20% (w/v) when dissolved in 50% COA. Although NAVI is a highly effective chemotherapeutic, it is equally thrombocytopenic. We found that COA-mediated topical delivery of NAVI enhanced its penetration into the skin and held the drug in the deeper skin layers for an extended period. Topical delivery of NAVI produced a higher cancer-cell killing efficacy than orally administrated NAVI. In vivo experiments in a mouse model of human melanoma-induced skin cancer confirmed the formulation's effectiveness via an apoptotic mechanism without any significant skin irritation or systemic absorption of NAVI. Overall, this topical approach may provide a safe and effective option for better managing skin cancer in the clinic.

A comparison of the outcome of Gun Shot Wounds with and without skin closure in terms of wound healing time and wound infection.

Objective: To compare the outcome of Gun Shot Wounds with and without skin closure in terms of wound healing time and wound infection. Study Design: Comparative Study. Setting: East Surgical Ward Mayo Hospital Lahore Pakistan. Period: 6 Months (from 1st January 2020 to 30th June 2020). Material & Methods: Sample size of 300 patients was used by consecutive convenient non probability sampling. Patients were divided into Group A and Group B with 150 patients in each group by lottery method. Group A patients underwent wound debridement and primary skin closure while group B patients underwent wound debridement and wound packing. Outcome was measured in terms of wound healing time and wound infection 24 and 48 hours post operatively. P-value less than 0.05 was taken as significant. Results: Two hundred and fourteen (n=214,71.33 %) patients were male and 86 (28.66 %) were female with mean age of 32 ± 7.56 years. The wound healing time in Group A patients was 6 days ± 2.18 days while in group B it was 13 days ± 3.87 days (P value 0.01). After 24 hours, Frequency of wound infection was 43 (14.3%) in Group A patients while 31(10.3%) in Group B patients (P value = 0.19). Similarly, after 48 hours wound infection rate was 17 (5.6%) in Group A while 11 (3.6%) in Group B (P value = 0.42). Conclusion: Applying skin stiches on Gun Shot Wounds after sufficient debridement and irrigation leads to early healing of the wound.

Combined nivolumab and ipilimumab with or without stereotactic body radiation therapy for advanced Merkel cell carcinoma: a randomised, open label, phase 2 trial

Merkel cell carcinoma is among the most aggressive and lethal of primary skin cancers, with a high rate of distant metastasis. Anti-programmed death receptor 1 (anti-PD-1) and programmed death ligand 1 (PD-L1) monotherapy is currently standard of care for unresectable, recurrent, or metastatic Merkel cell carcinoma. We assessed treatment with combined nivolumab plus ipilimumab, with or without stereotactic body radiotherapy (SBRT) in patients with advanced Merkel cell carcinoma as a first-line therapy or following previous treatment with anti-PD-1 and PD-L1 monotherapy. In this randomised, open label, phase 2 trial, we randomly assigned adults from two cancer sites in the USA (one in Florida and one in Ohio) to group A (combined nivolumab and ipilimumab) or group B (combined nivolumab and ipilimumab plus SBRT) in a 1:1 ratio. Eligible patients were aged at least 18 years with histologically proven advanced stage (unresectable, recurrent, or stage IV) Merkel cell carcinoma, a minimum of two tumour lesions measureable by CT, MRI or clinical exam, and tumour tissue available for exploratory biomarker analysis. Patients were stratified by previous immune-checkpoint inhibitor (ICI) status to receive nivolumab 240 mg intravenously every 2 weeks plus ipilimumab 1 mg/kg intravenously every 6 weeks (group A) or the same schedule of combined nivolumab and ipilimumab with the addition of SBRT to at least one tumour site (24 Gy in three fractions at week 2; group B). Patients had to have at least two measurable sites of disease so one non-irradiated site could be followed for response. The primary endpoint was objective response rate (ORR) in all randomly assigned patients who received at least one dose of combined nivolumab and ipilimumab. ORR was defined as the proportion of patients with a complete response or partial response per immune-related Response Evaluation Criteria in Solid Tumours. Response was assessed every 12 weeks. Safety was assessed in all patients. This trial is registered with ClinicalTrials.gov, NCT03071406. 50 patients (25 in both group A and group B) were enrolled between March 14, 2017, and Dec 21, 2021, including 24 ICI-naive patients (13 [52%] of 25 group A patients and 11 [44%] of 25 group B patients]) and 26 patients with previous ICI (12 [48%] of 25 group A patients and 14 [56%] of 25 group B patients]). One patient in group B did not receive SBRT due to concerns about excess toxicity. Median follow-up was 14·6 months (IQR 9·1-26·5). Two patients in group B were excluded from the analysis of the primary endpoint because the target lesions were irradiated and so the patients were deemed non-evaluable. Of the ICI-naive patients, 22 (100%) of 22 (95% CI 82-100) had an objective response, including nine (41% [95% CI 21-63]) with complete response. Of the patients who had previously had ICI exposure, eight (31%) of 26 patients (95% CI 15-52) had an objective response and four (15% [5-36]) had a complete response. No significant differences in ORR were observed between groups A (18 [72%] of 25 patients) and B (12 [52%] of 23 patients; p=0·26). Grade 3 or 4 treatment-related adverse events were observed in 10 (40%) of 25 patients in group A and 8 (32%) of 25 patients in group B. First-line combined nivolumab and ipilimumab in patients with advanced Merkel cell carcinoma showed a high ORR with durable responses and an expected safety profile. Combined nivolumab and ipilimumab also showed clinical benefit in patients with previous anti-PD-1 and PD-L1 treatment. Addition of SBRT did not improve efficacy of combined nivolumab and ipilimumab. The combination of nivolumab and ipilimumab represents a new first-line and salvage therapeutic option for advanced Merkel cell carcinoma. Bristol Myers Squibb Rare Population Malignancy Program.

Preclinical Assessment of Aceclofenac Transdermal Patch by Freund’s Complete Adjuvant-induced Arthritis in Rats

>The hydroxypropyl methylcellulose (HPMC) based transdermal patches of aceclofenac were prepared. On the basis of in-vitro potential, the formulation was additionally chosen and assessed for their in-vivo anti-arthritic activity and acute skin irritation tests using the primary skin irritation (draize) test and freund’s complete adjuvant (FCA) caused arthritis technique. Furthermore, stability studies were conducted in compliance with ICH standards. The studied compositions had no irritant potential, and no edema production was ever noticed. All of the formulations had a zero irritation score (primary skin irritation index), indicating their safety and acceptability for transdermal administration. The stability investigations confirmed the produced patch’s stability, and the in-vivo analysis showed a considerable decrease in the volume of irritated paws compared to the marketed formulation. The created transdermal patches may serve as a platform for the delivery of medication for the treatment of arthritis

32793 How can we teach clerkship medical students the multidisciplinary aspects of dermatology? A medical education initiative

Background: Canadian medical schools offer minimal clinical dermatology training for clerkship students. The limited available educational resources for them usually focus on primary skin conditions, therefore it is challenging for students to understand the multidisciplinary nature of dermatology in a clinical setting. The study objective was to develop case-based educational resources to help bridge this gap and assess their effectiveness.

Mutant WDR45 Leads to Altered Ferritinophagy and Ferroptosis in β-Propeller Protein-Associated Neurodegeneration.

Beta-propeller protein-associated neurodegeneration (BPAN) is a subtype of neurodegeneration with brain iron accumulation (NBIA) caused by loss-of-function variants in WDR45. The underlying mechanism of iron accumulation in WDR45 deficiency remains elusive. We established a primary skin fibroblast culture of a new BPAN patient with a missense variant p.(Asn61Lys) in WDR45 (NM_007075.3: c.183C>A). The female patient has generalized dystonia, anarthria, parkinsonism, spasticity, stereotypies, and a distinctive cranial MRI with generalized brain atrophy, predominantly of the cerebellum. For the functional characterization of this variant and to provide a molecular link of WDR45 and iron accumulation, we looked for disease- and variant-related changes in the patient’s fibroblasts by qPCR, immunoblotting and immunofluorescence comparing to three controls and a previously reported WDR45 patient. We demonstrated molecular changes in mutant cells comprising an impaired mitochondrial network, decreased levels of lysosomal proteins and enzymes, and altered autophagy, confirming the pathogenicity of the variant. Compared to increased levels of the ferritinophagy marker Nuclear Coactivator 4 (NCOA4) in control cells upon iron treatment, patients’ cells revealed unchanged NCOA4 protein levels, indicating disturbed ferritinophagy. Additionally, we observed abnormal protein levels of markers of the iron-dependent cell death ferroptosis in patients’ cells. Altogether, our data suggests that WDR45 deficiency affects ferritinophagy and ferroptosis, consequentially disturbing iron recycling.

602 Using Plastic Surgery Techniques in Abdominal Wall Surgery

Abstract Complex Abdominal Wall Hernias (CAWH) present a huge challenge to surgeons and patients often requiring Abdominal Wall Reconstruction (AWR). AWR aims to restore abdominal wall anatomy, improve function, and reduce the risk of future herniation. Plastic surgery techniques can be used including primary closure, skin grafts, flaps, tissue expansion and small bite, small stitch technique. Below are two cases where some of these techniques were utilised. Case 1 LC is a 65 y/o female with CAWH. Her gastric band became infected requiring a laparotomy for perforation of gastroesophageal junction. She subsequently had primary open repair of abdominal hernia using Permacol. It became infected requiring 5 debridements and application of a VAC device. Her hernia was a Ventral Hernia Working Group (VHWG) grade 3 at 10cm×16cm. Her CAWH was repaired using a Rives-Stoppa technique and a Surgimend mesh. The epigastric component of her wound was closed using a superiorly based local rhomboid flap and a Prevena VAC dressing. Case 2 KH is a 37 y/o female with a para-ileal conduit skin granuloma that was painful and refractory to other treatments such as silver nitrate and steroid topical treatments. She had excision of the area of granulation and her wound was closed using a local advancement flap taking account of previous scars raised and a prevena VAC dressing. Discussion CAWH requiring AWR is a complex operation benefiting from plastic surgical specialists. Plastic surgical techniques can help with closure of the abdominal wall and reduce complication rates including wound infections and incisional hernia.