Limpet grazing and loss of Ascophyllum nodosum canopies on decadal time scales

The role of limpet grazing in preventing the development of algal canopies is a recurrent theme in intertidal ecology. Less is known about interactions of limpets with the long-term dynamics of established canopies. Aerial photographs indicate that intertidal canopy cover has declined over the past 44 yr in Strangford Lough, Northern Ireland. There has been a loss of the previously continuous cover of Ascophyllum nodosum (L.) Le Jolis in the mid-shore. A barnacles dominated assemblage now fills gaps in the A. nodosum canopy. The rates at which barnacle patches become established and grow have increased since 1990. Changes in canopy cover have been accompanied by increases in limpet densities since the 1980s. Measurements between 2003 and 2004 showed no increase in length of A. nodosum fronds when limpets Patella vulgata had access to the algal holdfasts. In contrast, when limpets were experimentally excluded from the holdfasts, there was net frond growth. In the Isle of Man, which is climatically similar to Strangford Lough but has fewer limpets, growth occurred regardless of limpet grazing. The breaking force for A. nodosum declined with increasing local densities of limpets. A. nodosum is a sheltered shore species, potentially vulnerable to changes in wave exposure. There is no evidence, however, that Strangford Lough has become windier over the past 3 decades. Variation in wave exposure among locations within the lough was not related to rates of barnacle patch creation or expansion, Limpet population density has increased following a series of mild winters. Climate change may have a role in causing canopy loss, not by direct effects on the limpet populations.

Subsidy by Ascophyllum nodosum increases growth rate and survivorship of Patella vulgata

Limpets, predominantly Patella vulgata, have been associated with damaged or receding canopies of Ascophyllum nodosum. Although damage results from limpet grazing, the benefits that limpets gain from this behaviour are unclear as A. nodosum is thought to be well defended from grazers by anti-herbivore compounds. In the present study, R vulgata individuals were enclosed at densities between 80 and 320 m(-2) at 2 sites within Strangford Lough, Northern Island. Limpet growth and limpet survival were compared between unsubsidised controls and treatments in which limpet diets were subsidised by fronds of A. nodosum. When subsidised, limpet residual growth rates were significantly higher and mortality was lower than in unsubsidised control treatments. Individual limpets consumed a similar amount of A. nodosum regardless of limpet density. Higher densities of limpets, therefore, consumed more A. nodosum per replicate. The effects of A. nodosum in maintaining limpet densities could resonate through sheltered rocky communities. The importance of a macroalgal subsidy in supporting limpet populations may have been underestimated or overlooked in earlier studies. Therefore, the extensive and productive macroalgal canopies that characterise many sheltered temperate rocky shores could be more sensitive to increased limpet abundances than previously thought.

Flagging up sunburn: a printable, multicomponent, UV-indicator that warns of the approach of erythema

A printable, multicomponent, UV-sensitive indicator which provides different coloured, flag-like warnings of the approach to erythema is described.

Distribution of arsenic and risk assessment of activities on a golf course fertilised with arsenic-containing Ascophyllum nodosum seaweed

The use of seaweed fertilisers in sports green maintenance has become a common practice across the globe due to its image as an “eco-friendly” alternative to chemical fertilisers. The aim of this study was to characterise the risk of human exposure to arsenic (As), via dermal absorption, from golfing activities on a private golf course in the UK, where As contaminated seaweed fertiliser (~ 100 mg/kg d.wt.) is applied. This was fulfilled by, 1) determining As concentrations in shallow soils with GIS geo-statistical analysis, 2) measuring As concentrations from an on-site borehole groundwater well, and (3) developing a risk assessment calculation for golfing activities based on field and questionnaire data. Total As concentrations in shallow soils were less than the UK threshold for domestic soils, however, frequent and sustained dermal contact between site-users and surface soil attributed to a maximum carcinogenic risk value of 2.75 × 10− 4, which is in the upper limit of the acceptable risk range. Arsenic concentrations in underlying groundwater exceeded the WHO's permissible drinking water standard, demonstrating the risk of groundwater contamination following the application of seaweed fertiliser to golf course soils. This is the first risk study on dermal As absorption via the application of a seaweed fertiliser.

UV dosimeter based on dichloroindophenol and tin(IV) oxide

A UVB specific dosimeter is described comprising: a redox dye (2,6-dichloroindophenol, DCIP), a semiconductor ( tin(IV) oxide, SnO2) and a sacrificial electron donor ( glycerol) dispersed in a polymer ( hydroxy ethyl cellulose, HEC) film. The dosimeter is blue in the absence of UVB light but rapidly loses colour on exposure to UVB light. The spectral characteristics of a typical UVB dosimeter film and the mechanism by which the colour change occurs are detailed. DCIP UVB dosimeter films exhibit a response that is related to the irradiance level and duration of UVB exposure, the level of SnO2 present and to a lesser extent the level of glycerol present. The response of the dosimeter appears to be independent of dye concentration and film thickness. Furthermore, DCIP UVB dosimeter films respond to solar simulated light, exhibiting a colour loss that can be simply related to the Minimal Erythemal Dose (MED) exposure for skin type II. As a consequence, such indicators have potential for measuring solar radiation exposure and providing an early warning of erythema for most Caucasian skin (i.e. skin type II).

Oxaliplatin/capecitabine versus oxaliplatin/infusional 5-FU in advanced colorectal cancer: The MRC COIN Trial.

Background:

COIN compared first-line continuous chemotherapy with the same chemotherapy given intermittently or with cetuximab in advanced colorectal cancer (aCRC).


Methods:

Choice between oxaliplatin/capecitabine (OxCap) and oxaliplatin/leucovorin (LV)/infusional 5-FU (OxFU) was by physician and patient choice and switching regimen was allowed. We compared OxCap with OxFU and OxCap+cetuximab with OxFU+cetuximab retrospectively in patients and examined efficacy, toxicity profiles and the effect of mild renal impairment.


Results:

In total, 64% of 2397 patients received OxCap(±cetuximab). Overall survival, progression free survival and overall response rate were similar between OxCap and OxFU but rate of radical surgeries was higher for OxFU. Progression free survival was longer for OxFU+cetuximab compared with OxCap+cetuximab but other efficacy measures were similar. Oxaliplatin/LV/infusional 5-FU (±cetuximab) was associated with more mucositis and infection whereas OxCap(±cetuximab) caused more gastrointestinal toxicities and palmar-plantar erythema. In total, 118 patients switched regimen, mainly due to toxicity; only 16% came off their second regimen due to intolerance. Patients with creatinine clearance (CrCl) 50–80?ml?min-1 on OxCap(±cetuximab) or OxFU+cetuximab had more dose modifications than those with better renal function.


Conclusions:

Overall, OxFU and OxCap are equally effective in treating aCRC. However, the toxicity profiles differ and switching from one regimen to the other for poor tolerance is a reasonable option. Patients with CrCl 50–80?ml?min-1 on both regimens require close toxicity monitoring.

The colonization of macroalgal rafts by the genus Idotea (sub-phylum Crustacea; Order Isopoda):An active or passive process?

The association of invertebrate communities with macroalgae rafts has received much attention over recent decades, yet significant gaps in our knowledge remain with respect to the colonization process. Using laboratory-based experiments and in situ field trials in Strangford Lough, Northern Ireland, this study investigated whether members of the known rafting genus Idotea (sub-phylum Crustacea; order Isopoda) could effectively colonize rafts after shore seaweed detachment, or if their presence merely reflected a passive marooning process. Test tank arenas were used to identify traits that may influence the rafting potential of the dominant shore species Idotea granulosa and the well known rafter Idotea baltica. When released mid-water, I. granulosa initially ascended and associated with floating seaweed whereas I. baltica tended to descend with no clear habitat association. These findings conflict with the differential distribution of these Idotea species among rafts and shore algae, thus highlighting the complex nature of the potential of organisms to raft. In the field we considered the relative ability of different Idotea species to colonize tethered rafts composed of Ascophyllum nodosum and Fucus vesiculosus, cleaned of all vagile organisms and deployed at locations adjacent to established intertidal Idotea species populations. At the end of the experiment (after 44 days) rafts were inhabited by known rafting and shoreline species, confirming that colonization can occur after algal detachment. Previously considered shoreline species on occasion outnumbered well known rafters suggesting that a wide range of Idotea species can readily avail of macroalgal rafts as a potential dispersal mechanism or alternative habitat. © 2012 Marine Biological Association of the United Kingdom.

Hydrogel-Forming Microneedles Increase in Volume During Swelling in Skin, but Skin Barrier Function Recovery is Unaffected

We describe, for the first time, quantification of in-skin swelling and fluid uptake by hydrogel-forming microneedle (MN) arrays and skin barrier recovery in human volunteers. Such MN arrays, prepared from aqueous blends of hydrolyzed poly(methylvinylether/maleic anhydride) (15%, w/w) and the cross-linker poly(ethyleneglycol) 10,000 Da (7.5%, w/w), were inserted into the skin of human volunteers (n = 15) to depths of approximately 300 μm by gentle hand pressure. The MN arrays swelled in skin, taking up skin interstitial fluid, such that their mass had increased by approximately 30% after 6 h in skin. Importantly, however, skin barrier function recovered within 24 h after MN removal, regardless of how long the MN had been in skin or how much their volume had increased with swelling. Further research on closure of MN-induced micropores is required because transepidermal water loss measurements suggested micropore closure, whereas optical coherence tomography indicated that MN-induced micropores had not closed over, even 24 h after MN had been removed. There were no complaints of skin reactions, adverse events, or strong views against MN use by any of the volunteers. Only some minor erythema was noted after patch removal, although this always resolved within 48 h, and no adverse events were present on follow-up.

Periodontal Manifestations of Chronic Atypical Neutrophilic Dermatosis With Lipodystrophy and Elevated Temperature (CANDLE) Syndrome in an 11 Year Old Patient

Introduction: Chronic atypical neutrophilic dermatosis with lipodystrophy and elevated temperature (CANDLE) is an auto inflammatory syndrome caused by an autosomal recessive gene mutation. This very rare syndrome has been reported in only 14 patients worldwide. A number of clinical signs have been reported including joint contractures, muscle atrophy, microcytic anaemia, and panniculitis-induced childhood lipodystrophy. Further symptoms include recurrent fevers, purpuric skin lesions, periorbital erythema and failure to thrive. This is the first reported case of periodontal manifestations associated with CANDLE syndrome. 
Case Presentation: An 11 year old boy was referred to Cork University Dental School and Hospital with evidence of severe periodontal destruction. The patient’s medical condition was managed in Great Ormond Street Children’s Hospital, London. The patient’s dental management included initial treatment to remove teeth of hopeless prognosis followed by prosthodontic rehabilitation using removable partial dentures. This was followed by further non-surgical periodontal treatment and maintenance. In the long term, the potential definitive restorative options, including dental implants, will be evaluated in discussion with the patient’s medical team.
Conclusion: Periodontitis as a manifestation of systemic disease is one of seven categories of periodontitis as defined by the American Academy of Periodontology 1999 classification system. A number of systemic diseases have been associated with advanced periodontal destruction including Diabetes Mellitus, Leukaemia and Papillon-Lefevre Syndrome. In the case described, treatment necessitated a multidisciplinary approach with input from medical and dental specialities for a young patient with severe periodontal destruction associated with CANDLE syndrome.

Methylene Blue-Loaded Dissolving Microneedles: Potential Use in Photodynamic Antimicrobial Chemotherapy of Infected Wounds

Photodynamic therapy involves delivery of a photosensitising drug that is activated by light of a specific wavelength, resulting in generation of highly reactive radicals. This activated species can cause destruction of targeted cells. Application of this process for treatment of microbial infections has been termed "photodynamic antimicrobial chemotherapy" (PACT). In the treatment of chronic wounds, the delivery of photosensitising agents is often impeded by the presence of a thick hyperkeratotic/necrotic tissue layer, reducing their therapeutic efficacy. Microneedles (MNs) are an emerging drug delivery technology that have been demonstrated to successfully penetrate the outer layers of the skin, whilst minimising damage to skin barrier function. Delivering photosensitising drugs using this platform has been demonstrated to have several advantages over conventional photodynamic therapy, such as, painless application, reduced erythema, enhanced cosmetic results and improved intradermal delivery. The aim of this study was to physically characterise dissolving MNs loaded with the photosensitising agent, methylene blue and assess their photodynamic antimicrobial activity. Dissolving MNs were fabricated from aqueous blends of Gantrez(®) AN-139 co-polymer containing varying loadings of methylene blue. A height reduction of 29.8% was observed for MNs prepared from blends containing 0.5% w/w methylene blue following application of a total force of 70.56 N/array. A previously validated insertion test was used to assess the effect of drug loading on MN insertion into a wound model. Staphylococcus aureus, Escherichia coli and Candida albicans biofilms were incubated with various methylene blue concentrations within the range delivered by MNs in vitro (0.1-2.5 mg/mL) and either irradiated at 635 nm using a Paterson Lamp or subjected to a dark period. Microbial susceptibility to PACT was determined by assessing the total viable count. Kill rates of >96%, were achieved for S. aureus and >99% for E. coli and C. albicans with the combination of PACT and methylene blue concentrations between 0.1 and 2.5 mg/mL. A reduction in the colony count was also observed when incorporating the photosensitiser without irradiation, this reduction was more notable in S. aureus and E. coli strains than in C. albicans.