Fatty acids negatively regulate platelet function through formation of noncanonical 15-lipoxygenase-derived eicosanoids.

The antiplatelet effect of polyunsaturated fatty acids is primarily attributed to its metabolism to bioactive metabolites by oxygenases, such as lipoxygenases (LOX). Platelets have demonstrated the ability to generate 15-LOX-derived metabolites (15-oxylipins); however, whether 15-LOX is in the platelet or is required for the formation of 15-oxylipins remains unclear. This study seeks to elucidate whether 15-LOX is required for the formation of 15-oxylipins in the platelet and determine their mechanistic effects on platelet reactivity. In this study, 15-HETrE, 15-HETE, and 15-HEPE attenuated collagen-induced platelet aggregation, and 15-HETrE inhibited platelet aggregation induced by different agonists. The observed anti-aggregatory effect was due to the inhibition of intracellular signaling including αIIbß3 and protein kinase C activities, calcium mobilization, and granule secretion. While 15-HETrE inhibited platelets partially through activation of peroxisome proliferator-activated receptor ß (PPARß), 15-HETE also inhibited platelets partially through activation of PPARα. 15-HETrE, 15-HETE, or 15-HEPE inhibited 12-LOX in vitro, with arachidonic acid as the substrate. Additionally, a 15-oxylipin-dependent attenuation of 12-HETE level was observed in platelets following ex vivo treatment with 15-HETrE, 15-HETE, or 15-HEPE. Platelets treated with DGLA formed 15-HETrE and collagen-induced platelet aggregation was attenuated only in the presence of ML355 or aspirin, but not in the presence of 15-LOX-1 or 15-LOX-2 inhibitors. Expression of 15-LOX-1, but not 15-LOX-2, was decreased in leukocyte-depleted platelets compared to non-depleted platelets. Taken together, these findings suggest that 15-oxylipins regulate platelet reactivity; however, platelet expression of 15-LOX-1 is low, suggesting that 15-oxylipins may be formed in the platelet through a 15-LOX-independent pathway.

Growth Curves of Subependymal Giant Cell Tumors in Tuberous Sclerosis Complex.

BACKGROUND AND PURPOSE: Growth of subependymal giant cell tumor and subependymal nodules has not been well-characterized. The purpose of this study was to determine whether growth curves can differentiate subependymal giant cell tumors from subependymal nodules. MATERIALS AND METHODS: Brain MR imaging of patients with tuberous sclerosis complex were retrospectively reviewed from 2002 to 2018. All lesions in the region of the foramen of Monro were measured. Lesions were categorized on the basis of maximal diameter at the most recent scan: small lesions (<1 cm), indeterminate lesions (>1 cm), and resected lesions (>1 cm and surgically resected). Growth velocity and acceleration on serial imaging were analyzed, and growth rates were calculated between 0 and 20 years of age and compared among the 3 categories. RESULTS: Forty-one patients were analyzed. The average age at the earliest scan was 5.9 (SD = 5.7) years. One hundred twenty-six small, 27 indeterminate, and 10 resected lesions were measured. Subependymal giant cell tumors grew faster than indeterminate lesions between 6 and 15 years of age. Indeterminate lesions grew faster than small lesions at 0-10 years of age. Resected lesions showed increased velocity and acceleration of growth compared with indeterminate lesions and small lesions on serial imaging. CONCLUSIONS: Growth differentiates subependymal nodules and subependymal giant cell tumors within the first 20 years of life, and the use of velocity and acceleration of growth may refine the diagnostic criteria of subependymal giant cell tumors. Additionally, 6-15 years of age may be an important period to monitor subependymal giant cell tumors at the foramen of Monro because increased growth may help to identify subependymal giant cell tumors that will continue to grow and result in obstructive hydrocephalus.

Bone Involvement in Hyperphosphatemic Familial Tumoral Calcinosis: A New Phenotypic Presentation.

Mutations in FGF23, KL, and GALNT3 have been identified as the cause for the development of hyperphosphatemic familial tumoral calcinosis (HFTC). Patients with HFTC typically present in childhood or adolescence with periarticular soft tissue deposits that eventually progress to disrupt normal joint articulation. Mutations in the GALNT3 gene were shown to account for the hyperphosphatemic state in both HFTC and hyperostosis-hyperphosphatemia syndrome (HHS), the latter characterized by bone involvement. We present the case of a patient of a Druze ethnic origin with known HFTC that presented to our department with the first documented case of pathologic fracture occurring secondary to the disease. Our report introduces this new phenotypic presentation, suggests a potential role for prophylactic bone screening, and highlights the need for preconception genetic screening in selected populations.

Secukinumab-associated localized granuloma annulare (SAGA): a case report and review of the literature.

Granuloma annulare (GA) is a benign, usually self-limited inflammatory skin dermatosis characterized clinically by pink-red to brown dermal papules or annular plaques. The main histologic feature is the presence of palisading or interstitial granulomas composed of necrobiotic collagen, elastic fibers, and mucin surrounded by a lymphohistiocytic infiltrate. Granuloma annulare is commonly associated with trauma, infections, diabetes mellitus, dyslipidemia, malignancy, thyroid disease, and a variety of medications. Two cases of GA have been reported in association with the use of secukinumab, a monoclonal antibody directed against interleukin 17A (IL17A), for the treatment of moderate-to-severe plaque psoriasis. We report the third case of secukinumab-associated GA in a 52-year-old woman with a history of diabetes mellitus type II, dyslipidemia, and non-alcoholic steatohepatitis. After four months of therapy with secukinumab, she presented with pink papules coalescing to plaques involving the antecubital fossae. Histology demonstrated a lymphohistiocytic palisading granuloma with central necrobiotic collagen and mucin, consistent with GA. Physicians should be aware of the possibility of GA developing in patients receiving secukinumab, especially in those with predisposing factors for GA. A better understanding of secukinumab-associated GA may lead to discoveries in GA pathogenesis and reveal broader immunomodulatory effects of secukinumab.

Changes to country-specific hepatitis A travel vaccination recommendation for UK travellers in 2017-responding to a vaccine shortage in the national context.

OBJECTIVES: A routine review of hepatitis A travel vaccination recommendations was brought forward in June 2017 due to hepatitis A vaccine shortages and a concurrent outbreak in men who have sex with men (MSM). There were three objectives: first, to document the review process for changing the recommendations for the UK travellers in June 2017. Second, to study the impact of these changes on prescribing in general practice in 2017 compared with the previous 5 years. Third, to study any changes in hepatitis A notifications in June-October 2017 compared with the previous 5 years. STUDY DESIGN: This is an observational study. METHODS: Travel vaccination recommendations for countries with either low-risk (<20%) or high-risk (>90%) status according to child hepatitis A seroprevalence were not changed. A total of 67 intermediate-risk countries with existing recommendations for most travellers and with new data on rural sanitation levels were shortlisted for the analysis. Data on child hepatitis A seroprevalence, country income status, access to sanitation in rural areas and traveller volumes were obtained. Information about the vaccine supply was obtained from Public Health England. Changes to the existing classification were made through expert consensus, based on countries' hepatitis A seroprevalence, sanitation levels, level of income, volume of travel and hepatitis A traveller cases. Data on the number of combined and monovalent hepatitis A-containing vaccines prescribed in England, 2012-2017, were obtained from the National Health Service Business Service Authorities. The number of monthly prescriptions for January-September 2017 was compared with the mean number of prescriptions for the same month in the previous 5 years (t-test, α = 5%, df = 4). The number of hepatitis A cases notified in June-October 2017 not related to the MSM outbreak was compared with the number of notifications in the same months in previous years. RESULTS: A total of 36 countries were downgraded based on good access (80+% of population) to sanitation in rural areas and the intermediate-risk status in terms of child hepatitis A seroprevalence. For these countries, vaccination would only be recommended to travellers staying long term, visiting friends and relatives or staying in areas without good sanitation. There was a significant decline in hepatitis A vaccine prescriptions in June-September 2017, and there was no increase in the number of notifications. CONCLUSIONS: Hepatitis A vaccination recommendations for travel were revised in 2017 following a systematic approach to maintain continuity of supply after a hepatitis A vaccine shortage and increased hepatitis A vaccine demand related to a large outbreak. Improved access to good sanitation in rural areas and low seroprevalence estimates among children have led to 36 countries to no longer require vaccination for most travellers. These changes do not seem to have impacted on hepatitis A notifications in England, although further research will be needed to quantify the impact more precisely.

The impact of new national guidance for the public health management of enteric fever in England.

OBJECTIVES: New guidance was published in England in February 2012 to support the public health management of enteric fever and reduce the risks of secondary transmission. The new guidance was evaluated to assess: STUDY DESIGN: Quantitative and qualitative evaluation of the implementation of new public health guidance. METHODS: A qualitative review of all non-travel-related cases from February 2010 to January 2014 to compare the risk of secondary transmission before and after the guidance introduction; an audit of clearance sampling for each case and their contacts reported in London from February 2012-January 2015 to compare with a previous London audit; and an online user survey in November 2014. RESULTS: The proportions of non-travel cases reported before and after the introduction of the new guidance were similar, 6% in 2010-2012 compared to 7% in 2012-2014 (P = 0.33). There was a 32% reduction in the number of clearance samples required for cases and the estimated period of exclusion from work or school was reduced from 54 days to 16 days. Compliance in case clearance improved from 53% to 90% and contact screening compliance improved from 42% to 80%. The targeted screening of contacts led to a significantly higher positive yield (3.6% from 1.5%, P = 0.003). All symptomatic co-travellers presented to a healthcare professional, suggesting that screening could be restricted to those in risk groups for transmission. Feedback from users highlighted additional areas, such as management of large organised groups of co-travellers and those diagnosed abroad, which has informed the update of the national guidance. CONCLUSIONS: The new guidance has not led to an increase in secondary transmission of enteric fever in England and findings have been used to inform an update of the guidance. The new guidance also represents a reduced burden of investigation and thus a likely reduced cost to patients, healthcare professionals, laboratories and environmental health officers.

High frequency jet ventilation for motion management during ablation procedures, a narrative review.

BACKGROUND: High frequency jet ventilation (HFJV) is a method of ventilation that has gained renewed interest over the recent years as it can reduce organ movement to near static conditions, thus enhancing surgical precision in minimal invasive procedures, for example, ablation procedures for atrial fibrillation and solid organ tumours. The aim of this review was to create a summary of the current evidence concerning the clinical use of HFJV for ablative procedures. METHOD: PubMed was searched for the key words high frequency ventilation and ablation January 1990-December 2016. RESULT: The search initially identified 34 papers, 14 met the inclusion criteria. Articles in other languages than English (n = 1), comments regarding other articles (n = 4) and articles that did not include HFJV or ablative procedures (n = 15) were excluded. Two articles were added from references in papers included from the primary search. Sixteen studies were finally included in the review; four updates/reviews and 12 papers with results from studies of HFJV on humans, with a total of 889 patients; 498 patients ventilated with HFJV and 391 controls. There were no randomised studies. The overall scientific quality of the studies was low. CONCLUSION: There is a lack of well-designed studies evaluating HFJV during ablation procedures. The available information, while sparse, supports the effect of less tissue movement, resulting in better surgical precision and outcome; such as shorter procedural time, fewer shock waves (ESWL) and less recurrence of atrial fibrillation. Randomised controlled studies are needed in this promising area of research to prove its superiority to standard ventilation.

Pathology of Naturally Occurring Bacillary Hemoglobinuria in Cattle.

Clostridium haemolyticum causes bacillary hemoglobinuria (BH), an infectious and usually fatal disease that occurs mostly in cattle, which is clinically characterized by jaundice, hemoglobinuria, and anemia. The trematode Fasciola hepatica has been commonly reported as the main predisposing factor that triggers this condition. The authors evaluated 20 naturally occurring cases of bovine BH to characterize the pathology and pathogenesis of the disease. Grossly, the most consistent finding was a large, frequently single focus of necrosis surrounded by a red to purple halo, observed most frequently on the parietal surface of the right and left hepatic lobes. Other findings were jaundice, dark-brown discoloration of kidneys, and red urine in the urinary bladder. Microscopically, characteristic lesions were locally extensive, necrotizing hepatitis with thrombosis and numerous intralesional Gram-positive rod-shaped bacteria, and acute renal tubular necrosis. By immunohistochemistry, many hepatocytes outside the necrotic focus in the liver were positive for activated caspase 3, suggesting that those cells were undergoing apoptosis. Ultrastructural evaluation revealed hepatocyte necrosis, hemolysis, and clumps of vegetative and sporulating bacilli within the liver. Polymerase chain reaction for the C. haemolyticum beta toxin gene was positive in randomly selected liver samples. No gross or microscopic lesions indicative of fascioliasis were detected in the liver of any animal, suggesting that other yet undetermined predisposing factors were associated with these cases of BH.

Insensitivity to pain induced by a potent selective closed-state Nav1.7 inhibitor.

Pain places a devastating burden on patients and society and current pain therapeutics exhibit limitations in efficacy, unwanted side effects and the potential for drug abuse and diversion. Although genetic evidence has clearly demonstrated that the voltage-gated sodium channel, Nav1.7, is critical to pain sensation in mammals, pharmacological inhibitors of Nav1.7 have not yet fully recapitulated the dramatic analgesia observed in Nav1.7-null subjects. Using the tarantula venom-peptide ProTX-II as a scaffold, we engineered a library of over 1500 venom-derived peptides and identified JNJ63955918 as a potent, highly selective, closed-state Nav1.7 blocking peptide. Here we show that JNJ63955918 induces a pharmacological insensitivity to pain that closely recapitulates key features of the Nav1.7-null phenotype seen in mice and humans. Our findings demonstrate that a high degree of selectivity, coupled with a closed-state dependent mechanism of action is required for strong efficacy and indicate that peptides such as JNJ63955918 and other suitably optimized Nav1.7 inhibitors may represent viable non-opioid alternatives for the pharmacological treatment of severe pain.

Cardiometabolic disease in South Asians: A global health concern in an expanding population.

Cardiovascular disease (CVD) is one of the main causes of mortality and morbidity worldwide. As an emerging population, South Asians (SAs) bear a disproportionately high burden of CVD relative to underlying classical risk factors, partly attributable to a greater prevalence of insulin resistance and diabetes and distinct genetic and epigenetic influences. While the phenotypic distinctions between SAs and other ethnicities in CVD risk are becoming increasingly clear, the biology of these conditions remains an area of active investigation, with emerging studies involving metabolism, genetic variation and epigenetic modifiers (e.g., extracellular RNA). In this review, we describe the current literature on prevalence, prognosis and CVD risk in SAs, and provide a landscape of translational research in this field toward ameliorating CVD risk in SAs.

12-HETrE inhibits platelet reactivity and thrombosis in part through the prostacyclin receptor.

The dihomo-γ-linolenic acid (DGLA)-derived metabolite of 12-lipoxygenase, 12-hydroxy-eicosatrienoic acid (12-HETrE), was recently shown to potently inhibit thrombus formation without prolonging bleeding in murine models. Although 12-HETrE was found to inhibit platelet activation via the Gαs signaling pathway, the Gαs-coupled receptor by which 12-HETrE mediates its antiplatelet effects has yet to be identified. Defining the receptor by which 12-HETrE exerts its effects is key to determining its therapeutic potential as an antiplatelet drug. Therefore, the goal of this study was to determine the Gαs-coupled platelet receptor through which 12-HETrE exerts its antiplatelet effects. In this study, we showed that pharmacological inhibition of the prostacyclin (IP) receptor in human platelets or genetic ablation of IP in murine platelets prevented 12-HETrE from blocking aggregation in vitro. Furthermore, the antithrombotic effects of 12-HETrE were significantly diminished in IP knockout mice in vivo. Together these data demonstrate that the antiplatelet effects of 12-HETrE are at least partially dependent on IP signaling. Importantly, this work identified 12-HETrE as a novel regulator of IP signaling that may aid in the rationale for design of novel therapeutics to inhibit platelet function. Additionally, this study provides further insight into the mechanism by which DGLA supplementation inhibits platelets function.

Human 15-LOX-1 active site mutations alter inhibitor binding and decrease potency.

Human 15-lipoxygenase-1 (h15-LOX-1 or h12/15-LOX) reacts with polyunsaturated fatty acids and produces bioactive lipid derivatives that are implicated in many important human diseases. One such disease is stroke, which is the fifth leading cause of death and the first leading cause of disability in America. The discovery of h15-LOX-1 inhibitors could potentially lead to novel therapeutics in the treatment of stroke, however, little is known about the inhibitor/active site interaction. This study utilizes site-directed mutagenesis, guided in part by molecular modeling, to gain a better structural understanding of inhibitor interactions within the active site. We have generated eight mutants (R402L, R404L, F414I, F414W, E356Q, Q547L, L407A, I417A) of h15-LOX-1 to determine whether these active site residues interact with two h15-LOX-1 inhibitors, ML351 and an ML094 derivative, compound 18. IC50 values and steady-state inhibition kinetics were determined for the eight mutants, with four of the mutants affecting inhibitor potency relative to wild type h15-LOX-1 (F414I, F414W, E356Q and L407A). The data indicate that ML351 and compound 18, bind in a similar manner in the active site to an aromatic pocket close to F414 but have subtle differences in their specific binding modes. This information establishes the binding mode for ML094 and ML351 and will be leveraged to develop next-generation inhibitors.

The role of circulating platelet transcripts.

Our understanding of platelets, anucleate cells with a traditional role in hemostasis and inflammation, has developed greatly over the last decade. Platelets' role in the systemic response of the body to vascular injury, inflammation, and infection has expanded as has our understanding of their importance to the body's regulation of these processes. One recently explored mechanism by which platelets regulate the body's inflammatory and immune response is through its endogenous RNA. Platelets' messenger RNA (mRNAs) and microRNA (miRNAs) profiles have been shown to reflect disease and disease risk factors and have been correlated with select human clinical phenotypes. Developing an understanding of platelet transcripts in the circulation elucidates how platelets function in both their traditional thrombotic role and non-traditional functions and may have widespread implications in several fields including thrombosis, infection, cancer, and systemic inflammation.

Contrast-enhanced CT facilitates rapid, non-destructive assessment of cartilage and bone properties of the human metacarpal.

OBJECTIVE: The aim of this work is to establish the human metacarpal as a new whole joint surface early-stage osteoarthritis (OA) model that enables comparisons of articular cartilage and subchondral bone through high resolution contrast-enhanced CT (CECT) imaging, mechanical testing, and biochemical analysis. DESIGN: The fourth metacarpal was obtained from 12 human cadaveric donors and baseline µCT imaging was followed by indentation testing. The samples were then immersed in anionic (Ioxaglate) and cationic (CA4+) iodinated contrast agent solutions followed by CECT. Cartilage GAG content and distribution was measured using the 1,9 dimethylmethylene blue (DMMB) assay and Safranin-O histology staining. Linear regression was performed to compare cartilage and subchondral bone properties. RESULTS: Strong and significant positive correlations were observed between CA4+ CECT attenuation and both GAG content (R(2) = 0.86) and equilibrium modulus (R(2) = 0.84), while correlations using Ioxaglate were insignificant (R(2) ≤ 0.24, P > 0.05). Subchondral bone plate (SBP) thickness negatively and significantly correlated with SBP mineral density (R(2) = 0.49). Cartilage GAG content significantly correlated with several trabecular bone properties, including positive correlations with bone volume fraction (%BV/TV, R(2) = 0.67), trabecular number (Tb.N, R(2) = 0.60), and trabecular thickness (R(2) = 0.42), and negative relationships with structural model index (SMI, R(2) = 0.78) and trabecular spacing (Tb.Sp, R(2) = 0.56). Similarly, equilibrium modulus correlated positively with %BV/TV (R(2) = 0.50), Tb.N (R(2) = 0.59) and negatively with Tb.Sp (R(2) = 0.55) and SMI (R(2) = 0.60). CONCLUSION: This study establishes the human metacarpal as a new early-stage OA model suitable for rapid, high resolution CECT imaging, mechanical testing, and biochemical analysis of the cartilage and subchondral bone, and for examining their inter-relationships.

Fate of necrotic volume after microwave ablation of multiple liver metastases.

BACKGROUND/AIMS: The aim of this study was to find the rate of shrinkage of necrosis and time of peak ablation volume after multiple microwave ablations in the treatment of multiple liver metastases of colorectal cancer. These factors are not known and are important in evaluation of treatment and identification of local recurrence, as microwave treatment is becoming more used thanks to improved technology in diagnostics and interventional therapy. METHODOLOGY: A retrospective analysis of non-cirrhotic patients with multiple liver only metastases of colorectal cancer, not suited for resection for this reason. Patients were selected for palliative microwave treatment at a liver multidisciplinary team conference. 68 ablations were made in six patients. Ablation volume was analysed with repeated imaging and computer analyses. RESULTS: The ablation volume peeks after 5-7 days where after reduction of the necrosis in the liver occurs logarithmically with a 60% reduction of ablation volume after 100 days and 80% after a year. DISCUSSION: Liver regeneration after microwave ablations occurs at a constant logarithmic rate after an initial expansion of the ablation volume during the first five days. Evaluation of ablation volume in comparison to tumour volume must take this into account so that follow-up imaging is properly timed.

Photoactive Electrospun Polymeric Meshes: Spatiotemporally Wetting of Textured 3-Dimensional Structures.

The preparation, characterization, and use of a UV responsive non-woven nanofiber polymeric mesh is reported that transitions from being hydrophobic to hydrophilic. Three distinct wetting profiles are observed during the wetting process. 3D hydrophilic cavities were created within the hydrophobic bulk material by using a photo mask to control the geometry and UV exposure time to control the depth of the region.

A multiple microwave ablation strategy in patients with initially unresectable colorectal cancer liver metastases - A safety and feasibility study of a new concept.

AIMS: Resection for colorectal cancer liver metastases is indicated when an R0 resection with preservation of a sufficient future liver remnant (FLR) is achievable. Multimodality conversion of initially unresectable patients to resectable is possible in some patients. We present results of a downstaging strategy using microwave ablation (MWA). PATIENTS AND METHODS: In patients where resection was precluded by absence of a tumour-free FLR due to the extent of segmental tumour engagement, but with the potential to clear the whole liver with multiple local ablations, MWA was performed at laparotomy using ultrasound guidance or computer-assisted navigation. Mortality and morbidity was recorded and the overall and disease-free survival of the ablated patients was compared to data of two historic cohorts. RESULTS: Ten of twenty treated patients were alive at median follow-up 25 months. There was no perioperative mortality, with MWA-associated complications being mild to moderate. The MWA group showed a 4-year overall survival of 41%, compared to 70% for a historic cohort of primarily resected patients and 4% for patients with palliative treatment. CONCLUSION: Results of the multiple ablation strategy in the defined population suggest a survival benefit, compared to palliative chemotherapy alone with acceptable associated morbidity and no perioperative mortality.