The Toxoplasma subpellicular network is highly interconnected and defines parasite shape for efficient motility and replication.

Apicomplexan parasites possess several specialized structures to invade their host cells and replicate successfully. One of these is the inner membrane complex (IMC), a peripheral membrane-cytoskeletal system underneath the plasma membrane. It is composed of a series of flattened, membrane-bound vesicles and a cytoskeletal subpellicular network (SPN) comprised of intermediate filament-like proteins called alveolins. While the alveolin proteins are conserved throughout the Apicomplexa and the broader Alveolata, their precise functions and interactions remain poorly understood. Here, we describe the function of one of these alveolin proteins, TgIMC6. Disruption of IMC6 resulted in striking morphological defects that led to aberrant motility, invasion, and replication. Deletion analyses revealed that the alveolin domain alone is largely sufficient to restore localization and partially sufficient for function. As this highlights the importance of the IMC6 alveolin domain, we implemented unnatural amino acid photoreactive crosslinking to the alveolin domain and identified multiple binding interfaces between IMC6 and two other cytoskeletal proteins - IMC3 and ILP1. To our knowledge, this provides the first direct evidence of protein-protein interactions in the alveolin domain and supports the long-held hypothesis that the alveolin domain is responsible for filament formation. Collectively, our study features the conserved alveolin proteins as critical components that maintain the parasite's structural integrity and highlights the alveolin domain as a key mediator of SPN architecture.

Management of hypertrophic scars in adults: A systematic review and meta-analysis.

Hypertrophic scars (HTS) are elevated scars which occur due to abnormalities in wound healing after injury and may be associated with pain, pruritus and functional impairment. Despite multiple available treatment options, there is no universal approach to treating HTS. We searched the Web of Science (Core Collection), MEDLINE and EMBASE databases. Title, abstract and full-text screening, along with data extraction, were performed in duplicate. Risk of bias was assessed using the Cochrane risk-of-bias tool. The Vancouver Scar Scale (VSS) scores and mean differences were used for meta-analysis. We screened 3800 abstracts and included 34 randomised controlled trials evaluating treatments for HTS in adults. Silicone and laser modalities improved VSS scores by 5.06 (95% CI: 6.78, 3.34) and 3.56 (95% CI: 5.58, 1.54), respectively. Intralesional triamcinolone combined with silicone or 5-fluorouracil was superior to intralesional triamcinolone monotherapy. Limitations of this study include exclusion of studies which did not utilise VSS, and pooling of studies based on common modalities. Further studies are needed to examine the efficacy of existing and emerging treatment modalities for HTS. Our study supports the treatment of HTS in adults with silicone gel or sheets, injected triamcinolone (preferably combined with 5-fluorouracil or silicone products), pulsed dye laser and fractionated CO2 laser.

Redo-aortic valve replacement in prior stentless prosthetic aortic valves: Transcatheter versus surgical approach.

OBJECTIVES: The objective was to compare outcomes of redo-aortic valve replacement (AVR) via surgical or transcatheter approach in prior surgical AVR with large percentage of prior stentless surgical AVR. BACKGROUND: With the introduction of transcatheter aortic valve replacement (TAVR), patients with increased surgical risks now have an alternative to redo surgical AVR (SAVR), known as valve-in-valve (ViV) TAVR. Stentless prosthetic aortic valves present a more challenging implantation for ViV-TAVR given the lack of structural frame. METHODS: We performed a retrospective study of 173 subjects who have undergone SAVR (N = 100) or ViV-TAVR (N = 73) in patients with prior surgical AVR at Wake Forest Baptist Medical Center from 2009 to 2019. Our study received the proper ethical oversight. RESULTS: The average ages in redo-SAVR and ViV-TAVR groups were 58.03 ± 13.86 and 66.57 ± 13.44 years, respectively (p < 0.0001). The redo-SAVR had significantly lower STS (2.78 ± 2.09 and 4.68 ± 5.51, p < 0.01) and Euroscores (4.32 ± 2.98 and 7.51 ± 8.24, p < 0.05). The redo-SAVR group had higher percentage requiring mechanical support (8% vs. 0%, p < 0.05) and vasopressors (53% vs. 0%, p < 0.0001), longer length of stay (13.65 ± 11.23 vs. 5.68 ± 7.64 days, p < 0.0001), and inpatient mortality (16% vs. 2.78%, p < 0.005). At 30-day follow-up, redo-SAVR group had higher rates of acute kidney injury (10% vs. 0%, p < 0.01), however ViV-TAVR group had more new left bundle branch blocks (6.85% vs. 0%, p < 0.05). No significant differences regarding re-hospitalization rates, stroke, or death up to 1-year. CONCLUSION: Although the ViV-TAVR group had higher risk patients, there were significantly fewer procedural complications, shorter length of stay, and similar mortality outcomes up to 1-year follow-up.

Persistent organic pollutants and risk of cutaneous malignant melanoma among women.

BACKGROUND: Despite the increasing trend of cutaneous malignant melanoma (CMM) incidence in Canada, especially among females, few risk factors other than ultraviolet radiation exposure, have been identified. AIM: We conducted a case-control study of 406 CMM cases and 181 controls to evaluate the potential impact of body burdens of various persistent organic pollutants on CMM risk. METHODS: Detailed data on potential confounding factors, including lifetime repeated sun exposure and skin reaction to repeated sun exposure, were collected. Gas chromatography tandem mass spectrometry was used to assay plasma levels of 14 polychlorinated biphenyl (PCB) congeners and 11 organochlorine (OC) pesticides among cases and controls. RESULTS: Statistically significant trends of increased CMM risk were observed with increasing plasma concentrations of multiple PCB congeners, including PCBs 138, 153, 170, 180, 183 and 187. For example, compared to lowest plasma concentration quartile of PCB-138, the second, third and fourth quartiles were associated with 1.7 (95% CI: 0.9-2.9), 2.3 (95% CI: 1.3-4.1) and 2.4 (95% CI: 1.3-4.5) -fold increased risks of CMM, respectively. Similarly, increasing plasma concentrations of several OC pesticides (i.e., ß-HCH, HCB, Mirex, oxychlordane and trans-Nonachlor) showed statistically significant trends with increased CMM risk. For example, compared to lowest plasma concentration quartile of ß-HCH, the second, third and fourth quartiles were associated with 1.3 (95% CI: 0.7-2.3), 2.1 (95% CI: 1.2-3.7) and 2.3 (95% CI: 1.2-4.4) -fold increased risks of CMM, respectively. CONCLUSION: Plasma levels of several persistent organic pollutants were highly correlated, suggesting that observed associations were not necessarily independent of each other. Given the highly correlated nature of exposure to PCB and OC analytes, sophisticated analyses that consider complex mixtures should be considered in future studies.

Hidradenitis suppurativa in East and Southeast Asian populations: a systematic review and meta-analysis.

Hidradenitis suppurativa (HS) is a chronic inflammatory skin condition that presents with recurrent inflammatory nodules and draining tunnels in the skin. Most HS studies have focused on Western populations, and the understanding of how HS characteristics differ in specific Asian ethnicities is poor. We conducted the first systematic review and meta-analysis to characterize HS patients from East and Southeast Asia. PubMed, Embase, and Ovid MEDLINE databases were searched from inception to June 12, 2020. English-language case-series, cross-sectional, observational, and randomized controlled trial studies investigating HS in East and Southeast Asian populations were screened by titles, abstracts, and articles in duplicate. Of 136 citations, 10 studies were included in the meta-analysis. Data on gender distribution, lesion distribution in the axilla and gluteal regions, and family history were extracted in duplicate. A random effects model was used for the meta-analysis. A total of 30,125 HS patients were included in the analysis. Most patients were male (66%, 95% CI = 60-72%). About half of Asian patients with HS develop lesions in the axilla (52%, 95% CI = 33-72%) and the buttocks (48%, 95% CI = 38-57%). Only a small subset had positive family history of HS (5%, 95% CI = 2-8%). We report an up-to-date characterization of HS in East and Southeast Asian populations and highlight differences in their Western counterparts. These results will hopefully improve understanding for how HS may manifest, lead to more personalized treatments for Asian patients with HS, and usher in a proper patient-centered approach to treating the disease.

Approach to allergic contact dermatitis caused by topical medicaments.

OBJECTIVE: To provide an approach to identifying topical medicament ingredients that cause allergic contact dermatitis (ACD) and to recognizing common clinical scenarios in which these ingredients might present. SOURCES OF INFORMATION: A retrospective chart review was conducted of patients patch tested at the Contact Dermatitis Clinic at St Paul's Hospital in Vancouver, BC, between November 2016 and June 2019. Data from the North American Contact Dermatitis Group from 2015 to 2016 and The Ottawa Hospital patch test clinic from 2000 to 2010 were also reviewed. MAIN MESSAGE: Topical antibiotics are the most common cause of ACD to medicaments and frequently cause cosensitization to multiple allergens. This hypersensitivity reaction is often seen following surgical procedures and should be distinguished from postoperative infection. Corticosteroid allergy is easy to miss and should be suspected in cases of corticosteroid-sensitive dermatoses that worsen despite appropriate treatment. Topical anesthetics and propylene glycol are other causes of ACD found in many prescription and over-the-counter products. CONCLUSION: Allergic contact dermatitis is easy to miss and should always be considered in cases of eczematous eruptions. A thorough drug history including all topical products-both prescription and over-the-counter-is critical. Patch testing can help identify specific allergens for the patient to avoid.

Approche de la dermatite de contact allergique causée par les médicaments topiques.

OBJECTIF: Fournir une approche pour déterminer quels sont les ingrédients contenus dans les médicaments topiques qui causent la dermatite de contact allergique (DCA) et reconnaître les scénarios cliniques courants où ces ingrédients pourraient être présents. SOURCES D'INFORMATION: Revue rétrospective des dossiers de patients ayant subi un test épicutané à la clinique de dermatite de contact de l'Hôpital Saint-Paul à Vancouver, en Colombie-Britannique, entre les mois de novembre 2016 et juin 2019. Ont également été évaluées, les données de 2015 à 2016 du North American Contact Dermatitis Group et celles de 2000 à 2010 de la clinique de test épicutané de l'Hôpital d'Ottawa. MESSAGE PRINCIPAL: Les antibiotiques topiques sont la cause la plus courante de DCA aux médicaments, et ils causent fréquemment la cosensibilisation à plusieurs allergènes. Cette réaction d'hypersensibilité survient souvent après une intervention chirurgicale, et il faut la différencier de l'infection postopératoire. L'allergie aux corticostéroïdes est facile à manquer, et il faut la soupçonner dans les cas de dermatose sensible aux corticostéroïdes qui s'aggravent malgré le traitement approprié. Les anesthésiques et le propylèneglycol topiques, trouvés dans de nombreux produits d'ordonnance ou en vente libre, sont d'autres causes de DCA. CONCLUSION: La dermatite de contact allergique est facile à manquer et doit toujours être envisagée dans les cas d'éruption eczémateuse. Il est essentiel d'établir l'historique des médicaments, dont tous les produits topiques d'ordonnance ou en vente libre. Le test épicutané contribue à déterminer quels allergènes spécifiques le patient doit éviter.

Neuroglian regulates Drosophila intestinal stem cell proliferation through enhanced signaling via the epidermal growth factor receptor.

The Drosophila intestine is an excellent system for elucidating mechanisms regulating stem cell behavior. Here we show that the septate junction (SJ) protein Neuroglian (Nrg) is expressed in intestinal stem cells (ISCs) and enteroblasts (EBs) within the fly intestine. SJs are not present between ISCs and EBs, suggesting Nrg plays a different role in this tissue. We reveal that Nrg is required for ISC proliferation in young flies, and depletion of Nrg from ISCs and EBs suppresses increased ISC proliferation in aged flies. Conversely, overexpression of Nrg in ISC and EBs promotes ISC proliferation, leading to an increase in cells expressing ISC/EB markers; in addition, we observe an increase in epidermal growth factor receptor (Egfr) activation. Genetic epistasis experiments reveal that Nrg acts upstream of Egfr to regulate ISC proliferation. As Nrg function is highly conserved in mammalian systems, our work characterizing the role of Nrg in the intestine has implications for the treatment of intestinal disorders that arise due to altered ISC behavior.

Fine-Tuning and training of densenet for histopathology image representation using TCGA diagnostic slides.

Feature vectors provided by pre-trained deep artificial neural networks have become a dominant source for image representation in recent literature. Their contribution to the performance of image analysis can be improved through fine-tuning. As an ultimate solution, one might even train a deep network from scratch with the domain-relevant images, a highly desirable option which is generally impeded in pathology by lack of labeled images and the computational expense. In this study, we propose a new network, namely KimiaNet, that employs the topology of the DenseNet with four dense blocks, fine-tuned and trained with histopathology images in different configurations. We used more than 240,000 image patches with 1000×1000 pixels acquired at 20× magnification through our proposed "high-cellularity mosaic" approach to enable the usage of weak labels of 7126 whole slide images of formalin-fixed paraffin-embedded human pathology samples publicly available through The Cancer Genome Atlas (TCGA) repository. We tested KimiaNet using three public datasets, namely TCGA, endometrial cancer images, and colorectal cancer images by evaluating the performance of search and classification when corresponding features of different networks are used for image representation. As well, we designed and trained multiple convolutional batch-normalized ReLU (CBR) networks. The results show that KimiaNet provides superior results compared to the original DenseNet and smaller CBR networks when used as feature extractor to represent histopathology images.

A Digital Pathology Solution to Resolve the Tissue Floater Conundrum.

CONTEXT.­: Pathologists may encounter extraneous pieces of tissue (tissue floaters) on glass slides because of specimen cross-contamination. Troubleshooting this problem, including performing molecular tests for tissue identification if available, is time consuming and often does not satisfactorily resolve the problem. OBJECTIVE.­: To demonstrate the feasibility of using an image search tool to resolve the tissue floater conundrum. DESIGN.­: A glass slide was produced containing 2 separate hematoxylin and eosin (H&E)-stained tissue floaters. This fabricated slide was digitized along with the 2 slides containing the original tumors used to create these floaters. These slides were then embedded into a dataset of 2325 whole slide images comprising a wide variety of H&E stained diagnostic entities. Digital slides were broken up into patches and the patch features converted into barcodes for indexing and easy retrieval. A deep learning-based image search tool was employed to extract features from patches via barcodes, hence enabling image matching to each tissue floater. RESULTS.­: There was a very high likelihood of finding a correct tumor match for the queried tissue floater when searching the digital database. Search results repeatedly yielded a correct match within the top 3 retrieved images. The retrieval accuracy improved when greater proportions of the floater were selected. The time to run a search was completed within several milliseconds. CONCLUSIONS.­: Using an image search tool offers pathologists an additional method to rapidly resolve the tissue floater conundrum, especially for those laboratories that have transitioned to going fully digital for primary diagnosis.

A novel technique for postclosure of large-bore sheaths using two Perclose devices.

OBJECTIVES: This study aimed to assess the feasibility, efficacy, and safety of a novel percutaneous postprocedure closure technique for large arterial sheath removal with the use of two Perclose ProGlide (Abbott Vascular Devices, Redwood City, CA) devices. BACKGROUND: Postprocedural closing of large-bore arteriotomies using the Perclose system can be difficult given the subsequent inability of the device to capture sufficient wall tissue. METHODS: Our study was a single-center retrospective analysis of 22 consecutive patients who underwent large arteriotomy closure via the postclosure technique with a 12-16-Fr sheath. Efficacy endpoints included successful deployment of the system and hemostasis. Safety endpoints included the incidence of major or minor vascular complications as defined by the Vascular Academic Research Consortium-2 (VARC-2) definitions at 30-day follow-up. RESULTS: The postclosure technique resulted in 100% technical success rate and no postprocedural bleeding or vascular complications. CONCLUSION: Postclosure technique is a safe, highly effective, and feasible percutaneous method to achieve large-bore arteriotomy hemostasis with low rates of major bleeding or vascular complications and favorable early outcome.

Yottixel - An Image Search Engine for Large Archives of Histopathology Whole Slide Images.

With the emergence of digital pathology, searching for similar images in large archives has gained considerable attention. Image retrieval can provide pathologists with unprecedented access to the evidence embodied in already diagnosed and treated cases from the past. This paper proposes a search engine specialized for digital pathology, called Yottixel, a portmanteau for "one yotta pixel," alluding to the big-data nature of histopathology images. The most impressive characteristic of Yottixel is its ability to represent whole slide images (WSIs) in a compact manner. Yottixel can perform millions of searches in real-time with a high search accuracy and low storage profile. Yottixel uses an intelligent indexing algorithm capable of representing WSIs with a mosaic of patches which are then converted into barcodes, called "Bunch of Barcodes" (BoB), the most prominent performance enabler of Yottixel. The performance of the prototype platform is qualitatively tested using 300 WSIs from the University of Pittsburgh Medical Center (UPMC) and 2,020 WSIs from The Cancer Genome Atlas Program (TCGA) provided by the National Cancer Institute. Both datasets amount to more than 4,000,000 patches of 1000 × 1000 pixels. We report three sets of experiments that show that Yottixel can accurately retrieve organs and malignancies, and its semantic ordering shows good agreement with the subjective evaluation of human observers.

Pan-cancer diagnostic consensus through searching archival histopathology images using artificial intelligence.

The emergence of digital pathology has opened new horizons for histopathology. Artificial intelligence (AI) algorithms are able to operate on digitized slides to assist pathologists with different tasks. Whereas AI-involving classification and segmentation methods have obvious benefits for image analysis, image search represents a fundamental shift in computational pathology. Matching the pathology of new patients with already diagnosed and curated cases offers pathologists a new approach to improve diagnostic accuracy through visual inspection of similar cases and computational majority vote for consensus building. In this study, we report the results from searching the largest public repository (The Cancer Genome Atlas, TCGA) of whole-slide images from almost 11,000 patients. We successfully indexed and searched almost 30,000 high-resolution digitized slides constituting 16 terabytes of data comprised of 20 million 1000 × 1000 pixels image patches. The TCGA image database covers 25 anatomic sites and contains 32 cancer subtypes. High-performance storage and GPU power were employed for experimentation. The results were assessed with conservative "majority voting" to build consensus for subtype diagnosis through vertical search and demonstrated high accuracy values for both frozen section slides (e.g., bladder urothelial carcinoma 93%, kidney renal clear cell carcinoma 97%, and ovarian serous cystadenocarcinoma 99%) and permanent histopathology slides (e.g., prostate adenocarcinoma 98%, skin cutaneous melanoma 99%, and thymoma 100%). The key finding of this validation study was that computational consensus appears to be possible for rendering diagnoses if a sufficiently large number of searchable cases are available for each cancer subtype.

A photoactivatable crosslinking system reveals protein interactions in the Toxoplasma gondii inner membrane complex.

The Toxoplasma gondii inner membrane complex (IMC) is an important organelle involved in parasite motility and replication. The IMC resides beneath the parasite's plasma membrane and is composed of both membrane and cytoskeletal components. Although the protein composition of the IMC is becoming better understood, the protein-protein associations that enable proper functioning of the organelle remain largely unknown. Determining protein interactions in the IMC cytoskeletal network is particularly challenging, as disrupting the cytoskeleton requires conditions that disrupt protein complexes. To circumvent this problem, we demonstrate the application of a photoreactive unnatural amino acid (UAA) crosslinking system to capture protein interactions in the native intracellular environment. In addition to identifying binding partners, the UAA approach maps the binding interface of the bait protein used for crosslinking, providing structural information of the interacting proteins. We apply this technology to the essential IMC protein ILP1 and demonstrate that distinct regions of its C-terminal coiled-coil domain crosslink to the alveolins IMC3 and IMC6, as well as IMC27. We also show that the IMC3 C-terminal domain and the IMC6 N-terminal domain are necessary for binding to ILP1, further mapping interactions between ILP1 and the cytoskeleton. Together, this study develops a new approach to study protein-protein interactions in Toxoplasma and provides the first insight into the architecture of the cytoskeletal network of the apicomplexan IMC.

A comparison of valve-in-valve transcatheter aortic valve replacement in failed stentless versus stented surgical bioprosthetic aortic valves.

OBJECTIVES: The objectives of this study were to compare short- and intermediate-term clinical outcomes, procedural complications, TAVR prosthesis hemodynamics, and paravalvular leak (PVL) in stentless and stented groups. BACKGROUND: Valve-in-valve (ViV) transcatheter aortic valve replacement (TAVR) is an alternative to surgical redo for bioprosthetic valve failure. There have been limited data on ViV in stentless surgical valves. METHODS: We retrospectively analyzed 40 patients who underwent ViV TAVR in prior surgical bioprosthetic valves at Wake Forest Baptist Medical Center from October 2014 to September 2017. Eighty percent (32/40) ViV TAVRs were in stentless, while 20% (8/40) were in stented bioprosthetic valves. RESULTS: The primary mode of bioprosthetic valve failure for ViV implantation in the stentless group was aortic insufficiency (78%, 25/32), while in the stented group was aortic stenosis (75%, 6/8). The ViV procedure success was 96.9% (31/32) in stentless group and 100% in stented group (8/8). There were no significant differences in all-cause mortality at 30 days between stentless and stented groups (6.9%, 2/31 versus 0%, 0/8, P = 0.33) and at 1 year (0%, 0/25 versus 0%, 0/5). In the stentless group, 34.4% (11/32) required a second valve compared to the stented group of 0% (0/8). There was a significant difference in the mean aortic gradient at 30-day follow-up (12.33 ± 6.33 mmHg and 22.63 ± 8.45 mmHg in stentless and stented groups, P < 0.05) and at 6-month follow-up (9.75 ± 5.07 mmHg and 24.00 ± 11.28 mmHg, P < 0.05), respectively. CONCLUSIONS: ViV in the stentless bioprosthetic aortic valve has excellent procedural success and intermediate-term results. Our study shows promising data that may support the application of TAVR in stentless surgical aortic valve. However, further and larger studies need to further validate our single center's experience.

Comparison of paravalvular aortic leak characteristics in the Medtronic CoreValve versus Edwards Sapien Valve: Paravalvular aortic leak characteristics.

OBJECTIVES: Temporally quantify and localize paravalvular aortic leak (PVL) after transcatheter aortic valve replacement (TAVR) in the Medtronic CoreValve (MCV) versus the Edwards Sapien Valve (ESV). BACKGROUND: In order to increase the precision of THV selection and PVL intervention, an understanding of PVL characteristics is essential. METHODS: The frequency, severity, and location of post-TAVR PVL were evaluated with transthoracic echocardiography pre-discharge, one month, and one-year post-procedure in 202 patients receiving a MCV (N = 120) or ESV (N = 81). This was done through application of a clock face to the short axis of the aortic valve in order to divide the area into three tertiles. RESULTS: Pre-discharge differences between PVL frequency and severity in the MCV and ESV lost significance over time. Localizing these trends, MCV PVL frequency and severity significantly decreased in the first and third tertiles during most time periods while PVL in the second tertile of the MCV or in any of the tertiles of the ESV failed to improve. Presence of pre-discharge PVL was predictive of 30-day HF readmission and/or death (OR = 3.16, 95% CI: 0.99-10.12). Presence of pre-discharge and 30-day PVL was predictive of 1-year HF readmissions and/or death (OR = 2.12, 95% CI: 1.09-4.13 and OR = 1.99, 95% CI: 0.96-4.12). CONCLUSIONS: When comparing the MCV and ESV, not all locations of PVL improve equally over time, which has implications for heart failure readmissions. This could be used to influence valve selection and to identify cases in which earlier intervention on PVL may be appropriate.