45 research outputs found

    Tensin links energy metabolism to extracellular matrix assembly.

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    The regulation of integrin function is key to fundamental cellular processes, including cell migration and extracellular matrix (ECM) assembly. In this issue, Georgiadou et al. (2017. J. Cell Biol. https://doi.org/10.1083/jcb.201609066) report that the metabolic sensor adenosine monophosphate-activated protein kinase influences tensin production to regulate α5β1-integrin and fibrillar adhesion assembly and thus reveal an important connection between energy metabolism and ECM assembly

    Soaking grapevine cuttings in water: a potential source of cross contamination by micro-organisms

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    Grapevine nurseries soak cuttings in water during propagation to compensate for dehydration and promote root initiation. However, trunk disease pathogens have been isolated from soaking water, indicating cross contamination. Cuttings of Vitis vinifera cv. Sunmuscat and V. berlandieri x V. rupestris rootstock cv. 140 Ruggeri were immersed in sterilized, deionised water for 1, 2, 4, 8 and 16 h. The soaking water was cultured (25°C for 3 days) on non-specific and specific media for fungi and bacteria. The base of each cutting was debarked and trimmed and three 3 mm thick, contiguous, transverse slices of wood cultured at 25°C for 3 days. The soaking water for both cultivars became contaminated with microorganisms within the first hour. Numbers of fungi iso-lated from the wood slices soaked for one hour were significantly greater than those from non-soaked cuttings. The number of bacterial colonies growing from the wood slices increased after soaking for 2‒4 h in Sunmuscat. In a second experiment Shiraz cuttings were soaked for 1, 2, 4, 8 and 24 h. The soaking water became contaminated within the first hour but only the bacterial count increased significantly over time. Microorganisms also established on the container surfaces within the first hour although there were no significant increases over 24 h. These results confirm that soaking cuttings is a potential cause of cross contamination and demonstrate contamination of cuttings occurs after relatively short periods of soaking. Avoiding exposing cuttings to water will reduce the transmission of trunk diseases in propagation

    Temporal trends in hospitalisation for stroke recurrence following incident hospitalisation for stroke in Scotland

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    <p>Background: There are few studies that have investigated temporal trends in risk of recurrent stroke. The aim of this study was to examine temporal trends in hospitalisation for stroke recurrence following incident hospitalisation for stroke in Scotland during 1986 to 2001.</p> <p>Methods: Unadjusted survival analysis of time to first event, hospitalisation for recurrent stroke or death, was undertaken using the cumulative incidence method which takes into account competing risks. Regression on cumulative incidence functions was used to model the temporal trends of first recurrent stroke with adjustment for age, sex, socioeconomic status and comorbidity. Complete five year follow-up was obtained for all patients. Restricted cubic splines were used to determine the best fitting relationship between the survival events and study year.</p> <p>Results: There were 128,511 incident hospitalisations for stroke in Scotland between 1986 and 2001, 57,351 (45%) in men. A total of 13,835 (10.8%) patients had a recurrent hospitalisation for stroke within five years of their incident hospitalisation. Another 74,220 (57.8%) patients died within five years of their incident hospitalisation without first having a recurrent hospitalisation for stroke. Comparing incident stroke hospitalisations in 2001 with 1986, the adjusted risk of recurrent stroke hospitalisation decreased by 27%, HR = 0.73 95% CI (0.67 to 0.78), and the adjusted risk of death being the first event decreased by 28%, HR = 0.72 (0.70 to 0.75).</p> <p>Conclusions: Over the 15-year period approximately 1 in 10 patients with an incident hospitalisation for stroke in Scotland went on to have a hospitalisation for recurrent stroke within five years. Approximately 6 in 10 patients died within five years without first having a recurrent stroke hospitalisation. Using hospitalisation and death data from an entire country over a 20-year period we have been able to demonstrate not only an improvement in survival following an incident stroke, but also a reduction in the risk of a recurrent event.</p&gt

    Case Reports1. A Late Presentation of Loeys-Dietz Syndrome: Beware of TGFβ Receptor Mutations in Benign Joint Hypermobility

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    Background: Thoracic aortic aneurysms (TAA) and dissections are not uncommon causes of sudden death in young adults. Loeys-Dietz syndrome (LDS) is a rare, recently described, autosomal dominant, connective tissue disease characterized by aggressive arterial aneurysms, resulting from mutations in the transforming growth factor beta (TGFβ) receptor genes TGFBR1 and TGFBR2. Mean age at death is 26.1 years, most often due to aortic dissection. We report an unusually late presentation of LDS, diagnosed following elective surgery in a female with a long history of joint hypermobility. Methods: A 51-year-old Caucasian lady complained of chest pain and headache following a dural leak from spinal anaesthesia for an elective ankle arthroscopy. CT scan and echocardiography demonstrated a dilated aortic root and significant aortic regurgitation. MRA demonstrated aortic tortuosity, an infrarenal aortic aneurysm and aneurysms in the left renal and right internal mammary arteries. She underwent aortic root repair and aortic valve replacement. She had a background of long-standing joint pains secondary to hypermobility, easy bruising, unusual fracture susceptibility and mild bronchiectasis. She had one healthy child age 32, after which she suffered a uterine prolapse. Examination revealed mild Marfanoid features. Uvula, skin and ophthalmological examination was normal. Results: Fibrillin-1 testing for Marfan syndrome (MFS) was negative. Detection of a c.1270G > C (p.Gly424Arg) TGFBR2 mutation confirmed the diagnosis of LDS. Losartan was started for vascular protection. Conclusions: LDS is a severe inherited vasculopathy that usually presents in childhood. It is characterized by aortic root dilatation and ascending aneurysms. There is a higher risk of aortic dissection compared with MFS. Clinical features overlap with MFS and Ehlers Danlos syndrome Type IV, but differentiating dysmorphogenic features include ocular hypertelorism, bifid uvula and cleft palate. Echocardiography and MRA or CT scanning from head to pelvis is recommended to establish the extent of vascular involvement. Management involves early surgical intervention, including early valve-sparing aortic root replacement, genetic counselling and close monitoring in pregnancy. Despite being caused by loss of function mutations in either TGFβ receptor, paradoxical activation of TGFβ signalling is seen, suggesting that TGFβ antagonism may confer disease modifying effects similar to those observed in MFS. TGFβ antagonism can be achieved with angiotensin antagonists, such as Losartan, which is able to delay aortic aneurysm development in preclinical models and in patients with MFS. Our case emphasizes the importance of timely recognition of vasculopathy syndromes in patients with hypermobility and the need for early surgical intervention. It also highlights their heterogeneity and the potential for late presentation. Disclosures: The authors have declared no conflicts of interes

    The influence of aphid parasitoids on the development of their hosts

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    Changes in wing development and development through the stadia of Aphis fabae are examined after parasitisation by Aphidius colemani along with the underlying mechanisms. Parasitoid oviposition into nymphs of winged gynoparae of A. fabae shows that wing development is inhibited and the earlier parasitism takes place, the stronger the effect. Consideration of the timing of events indicates that the active component(s) is most likely injected during oviposition and is not related to hatching and growing of the parasitoid larva. When extracts of venom glands are injected into late-second stadium aphids, many develop to fourth-stadium possessing rudimentary wingbuds, show developmental arrest and often die while moulting to the adult stage. Injections with extracts of female or male parasitoids into later stadia give similar results with regard to development to the adult but aphids injected in the late-fourth stadium develop normally. Experiments with long-day winged virginoparae reveal similar results in development to the adult but injections into long-day wingless aphids, which develop more rapidly, show this effect only when performed early in the third stadium. The earlier the injection before the final moult the greater the effect of the extract on preventing adult development. The results indicate that there is an active factor(s) in the female parasitoid’s venom that disrupts wing development and/or inhibits development to the adult; the loss of activity after treatment at 100 °C or with protease makes it likely that the factor(s) is a protein. Surprisingly, injections of extracts from male parasitoids have similar effects. The location and function of such a factor(s) in males are unknown. Fast Protein Liquid Chromatography is used to fractionate the parasitoid extracts and bioassays reveal activity in fractions 16-25. Aphidius ervi venom also inhibits development of A. fabae (a non-host) whereas A. colemani venom has no effect on the development of Megoura viciae (a non-host). Injection with lipopolysaccharides and infection with a fungal pathogen are used to test whether stimulation of the immune response affects wing development in the host and the possibility that the host is in control of inhibiting its own wing development in order to support its immune system is discussed.EThOS - Electronic Theses Online ServiceState Scholarship Foundation of Greece (IKY)GBUnited Kingdo

    Soaking grapevine cuttings in water: A potential source of cross contamination by micro-organisms

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    Grapevine nurseries soak cuttings in water during propagation to compensate for dehydration and promote root initiation. However, trunk disease pathogens have been isolated from soaking water, indicating cross contamination. Cuttings of Vitis vinifera cv. Sunmuscat and V. berlandieri x V. rupestris rootstock cv. 140 Ruggeri were immersed in sterilized, deionised water for 1, 2, 4, 8 and 16 h. The soaking water was cultured (25°C for 3 days) on non-specific and specific media for fungi and bacteria. The base of each cutting was debarked and trimmed and three 3 mm thick, contiguous, transverse slices of wood cultured at 25°C for 3 days. The soaking water for both cultivars became contaminated with microorganisms within the first hour. Numbers of fungi isolated from the wood slices soaked for one hour were significantly greater than those from non-soaked cuttings. The number of bacterial colonies growing from the wood slices increased after soaking for 2-4 h in Sunmuscat. In a second experiment Shiraz cuttings were soaked for 1, 2, 4, 8 and 24 h. The soaking water became contaminated within the first hour but only the bacterial count increased significantly over time. Microorganisms also established on the container surfaces within the first hour although there were no significant increases over 24 h. These results confirm that soaking cuttings is a potential cause of cross contamination and demonstrate contamination of cuttings occurs after relatively short periods of soaking. Avoiding exposing cuttings to water will reduce the transmission of trunk diseases in propagation. © Firenze University Press.Financial support by the ‘Programa de apoyo a la Investigación y Desarrollo (PAID-00-10) de la Universidad Politécnica de Valencia’ for David Gramaje during his three months in Australia is gratefully acknowledged. Financial support by Charles Sturt University and the Grape and Wine research and development Corporation for Helen Waite is also gratefully acknowledged.Peer Reviewe

    Impact, host range and chemical ecology of the lily beetle, Lilioceris lilii

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    The lily beetle (Lilioceris lilii, Coleoptera: Chrysomelidae) has a univoltine life cycle and a limited host range (Lilium, Fritillaria and Cardiocrinum). A survey of 237 professional growers indicates that L. lilii is a problem for many in the UK lily industry. A three-year field trial using six different Lilium indicated that the species Lilium regale is more resistant to L. lilii than the hybrids L. ‘Tiber’, L. ‘Brindisi’, L. ‘Conca d’Or’, L. ‘Eliganzer’ and L. ‘Golden Joy’. Phenology observations between the trial and an established population of the beetle have provided base-line data to which further observations can be compared. Future host susceptibility trials should use a standard lily such as L. regale against which others can be compared. Behavioural bioassays using a linear-track olfactometer demonstrated that the responses of L. lilii to hosts and conspecifics are at least in part odour-mediated. Significantly more diapaused females moved into airstreams containing the odour of intact hosts over clean air, to that of hosts and beetles combined over that of undamaged or manually-damaged plants, and into airstreams from intact plants over larval-infested plants. Pre-diapause males moved into the airstreams of intact hosts in preference to L. lilii-infested plants. Using air entrainment, gas chromatography (GC) and coupled gas chromatography-mass spectrometry (GC-MS), headspace volatiles from beetleinfested host plants have been collected and identified. From these compounds, methyl salicylate, nonanal, cis-jasmone, linalool, 6-methyl-5-hepten-2-one and β-pinene elicited electrophysiological responses from L. lilii using electroantennography (EAG) and coupled GC-EAG. Bioassays indicate that diapaused female beetles move into the airstream of clean air in preference to cis-jasmone. Investigations from all areas of the project have progressed our understanding of the ecology of L. lilii but further studies are needed before more effective control strategies can be developed.EThOS - Electronic Theses Online ServiceHorticultural Development CouncilGBUnited Kingdo

    Host-plant acceptance by aphids : cues initiating reproduction

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    The host-plant acceptance behaviour of aphids was examined, in two aphid species, the bird cherry-oat aphid, Rhopalosiphum padi and the pea aphid, Acyrthosiphum pisum, to elucidate the recognition factors used to assess plant suitability for parthenogenetic reproduction. In addition, host-plant chemistry was investigated to study possible cues that initiated reproduction. The probing and parturition behaviour of R. padi on barley, Hordeum vulgare, or bird cherry leaves, Prunus padus, were monitored by electrical penetration graph (EPG) coupled with a simultaneous video recording. The autumn winged gynoparae and the summer winged virginoparae initiated reproduction on their host plants, P. padus and H. vulgare, respectively, before phloem contact occurred and these findings suggest that phloem contact is not necessary for host-acceptance decisions. Host acceptance behaviour of A. pisum, on susceptible and phloem-based resistant line of Medicago truncatula was monitored and found to be similar on both plant lines. The phloem-based resistance mechanism did not affect parturition behaviour indicating that reproduction is initiated prior to phloem contact. The results also imply that sign chemicals used as host recognition cues located in a peripheral tissue rather than in the phloem of host plants. Bioassays were employed to characterise the sign chemicals within host-plants of R. padi. It was found that virginoparae reproduced similarly on a neutral medium such as water or holidic diet as well as host-plant aqueous extract, which suggests that particular stimulants may be not involved in host-plant recognition by this generalist morph. On the other hand, aqueous extracts of bird cherry leaves specifically stimulated parturition in autumn gynoparae. Bioassay-guided chemical fractionation showed that at least five secondary metabolites appear to be involved in host recognition by gynoparae.EThOS - Electronic Theses Online ServiceGovernment of KoreaGBUnited Kingdo
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