Commentary: Matrix metalloproteinase-13 unlucky for the forming thrombus

Matrix metalloproteinases (MMPs) are calcium‐dependent zinc‐containing endoproteases involved in extracellular matrix and non‐matrix protein degradation.1 In the latest issue of Research and Practice in Thrombosis and Haemostasis, Howes and colleagues2 investigated the role of MMP‐13 in platelet aggregation and thrombus formation and identified that MMP‐13 could engage important platelet receptors and influence platelet function in vitro. MMP‐13 is of great cardiovascular interest as expression of this metalloproteinase is significantly upregulated in a host of atherothrombotic and inflammatory conditions.

Physicochemical and flavor characterization of Tupelo honey

Nyssa ogeche (white Tupelo) trees are concentrated mainly in the Appalachicola region in the panhandle of Florida. The honey produced from the nectar of these trees is regarded as a premium honey because its non-granulating tendencies and limited supply due to the small growing region and short bloom time of the Tupelo trees. Unfortunately there are few studies of this unique honey, with only one study done on the physicochemical characteristics and one on the volatiles present. Therefore, it is necessary to conduct an exhaustive physicochemical and flavor characterization of Tupelo honey to confirm and expand upon the limited available research. Physicochemical characteristics were determined for ten Tupelo honey samples from five different locations collected during two consecutive seasons (2013 and 2014). These included moisture content, ⁰Brix, water activity (Aw), pH, titratable acidity, ash content, and fructose and glucose contents. On the basis of pollen analyses, nine samples could be considered as authentic Tupelo honeys, with one (designated honey 3 from the 2014 season) containing mainly holly pollen along with appreciable levels of tupelo pollen. This honey also had a noticeably higher pH value and differed significantly in ash content from the other Tupelo honey samples, suggesting ash content to be a good indicator of botanical origin. Sensory screening indicated this sample to be significantly different from the other samples as well. Honey 5 produced during both seasons was the most consistent sampling location with the highest amount of Tupelo pollen content present in each sample. Panelists could not distinguish a difference between the honey 5 samples from both seasons during sensory testing. The characteristic most widely known about Tupelo honey is its relatively high fructose content which was confirmed in this study. Composition data were comparable to literature values and within the limits set by Codex Alimentarius. To complete a full flavor characterization, aroma-active compounds in Tupelo honey were identified by gas chromatography-olfactometry (GC-O) and gas chromatography-mass spectrometry-olfactometry (GC-MS-O). Initial analyses were performed on the same ten samples as described above by static headspace solid phase microextraction (H-SPME). Of the 40 compounds detected, the most important compounds based on their perceived odor intensities determined by two assessors were phenylacetaldehye (rosy) and nonanal (citrus). Further analysis was carried out on honey 5 from the 2013 and 2014 seasons due to its consistently high Tupelo pollen content across seasons and the inability of sensory panelists to distinguish between the two samples. The most potent odorants were determined through aroma extract dilution analysis (AEDA) of solvent extracts and sample dilution analysis by H-SPME (SDA-H-SPME). The most potent odorants identified by both dilution analyses techniques were vanillin (vanilla), phenylacetaldehyde (rosy), nonanal (citrus), (E)-2-nonenal (dried hay), eugenol (cloves), guaiacol (smoky), 2-phenylethanol (rosy, wine), 2’-aminoacetophenone (grape, corn tortilla), (E)-β-damascenone (cooked apple), and an unidentified odorant (RIwax=1731) described as spicy and hay-like. (E)-β-Damascenone was determined to be the most potent odorant with extremely high flavor dilution (FD) factors of 59,049 (2013 season) and 19,683 (2014 season). Quantification of (E)-β-damascenone using stable isotope dilution analysis combined with H-SPME (SIDA-H-SPME) revealed that the compound had an extremely high concentration and odor-activity value (OAV) compared to other types of honeys and food products. (E)-β-Damascenone may be used as a marker compound to distinguish Tupelo honey from other unifloral honeys because of the uniquely high levels present in this honey

Quantifying Embolism: Label-Free Volumetric Mapping of Thrombus Structure and Kinesis in a Microfluidic System with Optical Holography

Embolization of thrombotic material may lead to acute events such as ischemia and myocardial infarction. The embolus is the physical detachment from a primary thrombus that has developed under fluid shear rates. The physical characteristics (surface area coverage, volume, mass, and packing density) of a thrombus influence the overall flow dynamics of an occluding blood vessel. Here, the effectiveness of holographic quantitative phase microscopy (QPM) in identifying multiple morphological parameters of a thrombus (volume, surface area, and height) formed over collagen‐coated microfluidic channels by exerting a range of shear rates with anticoagulated platelet‐rich plasma (PRP) and whole blood is demonstrated. QPM enables the recording of entire thrombus volumes in real‐time using PRP and observed both growth and contraction trends of thrombi, without need for biochemical labeling. The process of emboli detachment in a microfluidic channel under pathophysiological shear rates (7500 and 12 500 s−1) is quantified. Rapid and direct quantification of an embolizing thrombus can enable the study of events during undesirable vessel occlusion and lead to targeting and early diagnosis of acute coronary and venous events.The authors received funding from the National Health and Medical Research Council of Australia and the Australian Research Council

Codeine versus placebo for chronic cough in children (Review)

Background: Cough in children is a commonly experienced symptom that is associated with increased health service utilisation and burden to parents. The presence of chronic (equal to or more than four weeks) cough in children may indicate a serious underlying condition such as inhaled foreign body or bronchiectasis. Codeine (and derivative)-based medications are sometimes used to treat cough due to their antitussive properties. However, there are inherent risks associated with the use of these medications such as respiratory drive suppression, anaesthetic-induced anaphylaxis, and addiction. Metabolic response and dosage variability place children at increased risk of experiencing such side effects. A systematic review evaluating the quality of the available literature would be useful to inform management practices. Objectives: To evaluate the safety and efficacy of codeine (and derivatives) in the treatment of chronic cough in children. Search methods: We searched the Cochrane Airways Group Register of Trials, Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE (1946 to 8 June 2016), EMBASE (1974 to 8 June 2016), the online trials registries of the World Health Organization and ClinicalTrials.gov, and the bibliographic references of publications. We imposed no language restrictions. Selection criteria: We considered studies eligible for analysis when: the participant population included children aged less than 18 years with chronic cough (duration equal to or more than four weeks at the time of intervention); and the study design evaluated codeine or codeine-based derivatives against placebo through a randomised controlled trial. Data collection and analysis: Two review authors independently screened the search results to determine eligibility against a standardised criteria, and we had a pre-planned method for analysis. Main results: We identified a total of 556 records, of which 486 records were excluded on the basis of title and abstract. We retrieved the remaining 70 references in full to determine eligibility. No studies fulfilled the inclusion criteria of this review, and thus we found no evidence to support or oppose the use of codeine or derivatives as antitussive agents for chronic cough in children. While chronic cough is not the same as acute cough, systematic reviews on the use of codeine efficacy for acute cough in children conclude an overall lack of evidence to support or oppose the use of over-the-counter cough and cold medications containing codeine (or derivatives) for treatment of acute cough in children. The lack of sufficient evidence to support the use of these medications has been consistently reaffirmed by medical experts in international chronic cough guidelines and by governing medical and pharmaceutical authorities in the USA, Europe, Canada, New Zealand, and Australia. Due to the lack of sufficient evidence to support efficacy, and the known risks associated with use - in particular the increased risks for children - these medications are now not recommended for children less than 12 years of age and children between 12 to 18 years with respiratory conditions. Authors' conclusions: This review has highlighted the absence of any randomised controlled trials evaluating codeine-based medications in the treatment of childhood chronic cough. Given the potential adverse events of respiratory suppression and opioid toxicity, national therapeutic regulatory authorities recommend the contraindication of access to codeine in children less than 12 years of age. We suggest that clinical practice adhere to clinical practice guidelines and thus refrain from using codeine or its derivatives to treat cough in children. Aetiological-based management practices continue to be advocated for children with chronic cough

The urban-rural divide: Hypertensive disease hospitalisations in Victoria 2010–2015

BackgroundHypertension is present in 23–32 per cent of Australians, making it one of the most prevalent diseases in the country. It is the greatest risk factor for cardiovascular disease, the leading cause of death in Australia and it affects rural populations at a higher rate than urban residents.AimsThe aims of this study were to investigate the differences in hypertensive disease hospitalisations across rural and urban Victoria, and to determine predicting variables.MethodsHospital admission data from 1 July 2010 to 30 June 2015 were obtained through the Victorian Admitted Episodes Dataset and other organisations. Data included various patient demographics for each hospital admission entry. The rates of hospitalisation for each Local Government Area were analysed. Further regression analysis was undertaken to examine the association between hypertensive disease hospitalisation and various predictor variables.ResultsFrom 2010–2015 11,205 hypertensive disease hospital admissions were recorded of which 64.8 per cent were female, 74.7 per cent admissions were at urban hospitals, and 65.0 per cent were public patients. Hospitalisation rates were consistently higher in rural areas than in urban areas, and rural residents on average stayed in hospital for longer. Significant predictor variables for hypertensive disease hospitalisation included various indicators of socioeconomic disadvantage, GPs per 1,000 population and GP attendance per 1,000 population.ConclusionHypertensive disease hospitalisation in Victoria continues to rise and rates of hospitalisation of rural Victorians continue to be higher than their urban counterparts. Females were hospitalised almost twice as often as males. Further research is required to identify the specific factors that impede access to health services, particularly in the identified high-risk populations

The many streams of the Magellanic Stream

We present results from neutral hydrogen (HI) observations of the tip of the Magellanic Stream (MS), obtained with the Arecibo telescope as a part of the on-going survey by the Consortium for Galactic studies with the Arecibo L-band Feed Array. We find four large-scale, coherent HI streams, extending continously over a length of 20 degrees, each stream possessing different morphology and velocity gradients. The newly discovered streams provide strong support for the tidal model of the MS formation by Connors et al. (2006), which suggested a spatial and kinematic bifurcation of the MS. The observed morphology and kinematics suggest that three of these streams could be interpreted as a 3-way splitting of the main MS filament, while the fourth stream appears much younger and may have originated from the Magellanic Bridge. We find an extensive population of HI clouds at the tip of the MS. Two thirds of clouds have an angular size in the range 3.5'--10'. We interpret this as being due to thermal instability, which would affect a warm tail of gas trailing through the Galactic halo over a characteristic timescale of a few Myrs to a few hundred Myrs. We show that thermal fragments can survive in the hot halo for a long time, especially if surrounded by a <10^6 K halo gas. If the observed clumpy structure is mainly due to thermal instability, then the tip of the MS is at a distance of ~70 kpc. A significant fraction of HI clouds at the tip of the MS show multi-phase velocity profiles, indicating the co-existence of cooler and warmer gas.Comment: Accepted by Ap

High contrast imaging and flexible photomanipulation for quantitative in vivo multiphoton imaging with polygon scanning microscope

In this study, we introduce two key improvements that overcome limitations of existing polygon scanning microscopes while maintaining high spatial and temporal imaging resolution over large field of view (FOV). First, we proposed a simple and straightforward means to control the scanning angle of the polygon mirror to carry out photomanipulation without resorting to high speed optical modulators. Second, we devised a flexible data sampling method directly leading to higher image contrast by over 2‐fold and digital images with 100 megapixels (10 240 × 10 240) per frame at 0.25 Hz. This generates sub‐diffraction limited pixels (60 nm per pixels over the FOV of 512 μm) which increases the degrees of freedom to extract signals computationally. The unique combined optical and digital control recorded fine fluorescence recovery after localized photobleaching (r ~10 μm) within fluorescent giant unilamellar vesicles and micro‐vascular dynamics after laser‐induced injury during thrombus formation in vivo. These new improvements expand the quantitative biological‐imaging capacity of any polygon scanning microscope system.Australian Research Council, Grant/Award Number: DE16010084

Fibrin exposure triggers αIIbβ3-independent platelet aggregate formation, ADAM10 activity and glycoprotein VI shedding in a charge-dependent manner

Background Collagen and fibrin engagement and activation of glycoprotein (GP) VI induces proteolytic cleavage of the GPVI ectodomain generating shed soluble GPVI (sGPVI). Collagen‐mediated GPVI shedding requires intracellular signalling to release the sGPVI, mediated by A Disintegrin And Metalloproteinase 10 (ADAM10); however, the precise mechanism by which fibrin induces GPVI shedding remains elusive. Plasma sGPVI levels are elevated in patients with coagulopathies, sepsis, or inflammation and can predict onset of sepsis and sepsis‐related mortality; therefore, it is clinically important to understand the mechanisms of GPVI shedding under conditions of minimal collagen exposure. Objectives Our aim was to characterize mechanisms by which fibrin‐GPVI interactions trigger GPVI shedding. Methods Platelet aggregometry, sGPVI ELISA, and an ADAM10 fluorescence resonance energy transfer assay were used to measure fibrin‐mediated platelet responses. Results Fibrin induced αIIbβ3‐independent washed platelet aggregate formation, GPVI shedding, and increased ADAM10 activity, all of which were insensitive to pre‐treatment with inhibitors of Src family kinases but were divalent cation‐ and metalloproteinase‐dependent. In contrast, treatment of washed platelets with other GPVI ligands, collagen, and collagen‐related peptide caused αIIbβ3‐dependent platelet aggregation and GPVI release but did not increase constitutive ADAM10 activity. Conclusions Fibrin engages GPVI in a manner that differs from other GPVI ligands. Inclusion of polyanionic molecules disrupted fibrin‐induced platelet aggregate formation and sGPVI release, suggesting that electrostatic charge may play a role in fibrin/GPVI engagement. It may be feasible to exploit this property and specifically disrupt GPVI/fibrin interactions whilst sparing GPVI/collagen engagement.Fibrin engages GPVI in a manner that differs from other GPVI ligands. Inclusion of polyanionic molecules disrupted fibrin‐induced platelet aggregate formation and sGPVI release, suggesting that electrostatic charge may play a role in fibrin/GPVI engagement. It may be feasible to exploit this property and specifically disrupt GPVI/fibrin interactions whilst sparing GPVI/collagen engagement.National Health and Medical Research Council of Australia; Australian Research Council; THANZ Science and Education Research Gran

Loss of GPVI and GPIbα contributes to trauma-induced platelet dysfunction in severely injured patients

Trauma-induced coagulopathy (TIC) is a complex, multifactorial failure of hemostasis that occurs in 25% of severely injured patients and results in a fourfold higher mortality. However, the role of platelets in this state remains poorly understood. We set out to identify molecular changes that may underpin platelet dysfunction after major injury and to determine how they relate to coagulopathy and outcome. We performed a range of hemostatic and platelet-specific studies in blood samples obtained from critically injured patients within 2 hours of injury and collected prospective data on patient characteristics and clinical outcomes. We observed that, although platelet counts were preserved above critical levels, circulating platelets sampled from trauma patients exhibited a profoundly reduced response to both collagen and the selective glycoprotein VI (GPVI) agonist collagen-related peptide, compared with those from healthy volunteers. These responses correlated closely with overall clot strength and mortality. Surface expression of the collagen receptors GPIbα and GPVI was reduced on circulating platelets in trauma patients, with increased levels of the shed ectodomain fragment of GPVI detectable in plasma. Levels of shed GPVI were highest in patients with more severe injuries and TIC. Collectively, these observations demonstrate that platelets experience a loss of GPVI and GPIbα after severe injury and translate into a reduction in the responsiveness of platelets during active hemorrhage. In turn, they are associated with reduced hemostatic competence and increased mortality. Targeting proteolytic shedding of platelet receptors is a potential therapeutic strategy for maintaining hemostatic competence in bleeding and improving the efficacy of platelet transfusions