46 research outputs found
Studies on the infection of honey bee larvae with Ascosphaera apis
The fungus Ascosphaera apis causes the disease chalk brood in
larvae of the honey bee, Apis mellifera. Ascospores were recognised
as the agents of disease, but the site of their germination to
initiate infection had not been established. In this study larval
surface cuticle was initially investigated as a possible site, but
spores did not even activate here. Therefore, potential inhibitors
of spore germination were studied, including water and chloroform
washings of larval cuticle; 4 larval food constituents - pollen,
honey, brood food, royal jelly; and a variety of medium-chain fatty
acids a t concentrations of 1, 0.1 and 0. 01%. Royal jelly exhibited
a severe inhibitory effect on all germination stages.
Larvae were successfully infected by feeding them food
Containing A. apis spores, both in vitro and in vivo. A histological
study of infected larvae demonstrated germination of spores in the
mid-gut lumen, followed by penetration of the peritrophic membrane
and gut epithelium by developing hyphae; and subsequent invasion of
larval tissues by mycelia.
Various aspects of spore physiology were investigated. Spore
activation and enlargement were shown to be independent of temperature
within the ranges of 10 to 40°C and 25 to 40°C respectively, while
germ-tube production was closely temperature related, only occurring
between 25 and 37°C - with an optimum between 31 and 35°C . However,
all 3 germination stages were found to be independent of environmental
pH within the range of pH 5 to 7.8. Studies on the nutritional
requirements for germination revealed the need for exogenous supplies
of both a carbon and nitrogen source to support germ-tube production.
The ‘spore-ball phenomenon’ was investigated and a supplementary
amino acid source was identified .
The etiology of chalk brood is discussed in the light of these
findings
Only Connect? : Aspects of Intertextuality in Zadie Smith's On Beauty
Tutkielma käsittelee intertekstuaalisuuden eri muotoja Zadie Smithin romaanissa On Beauty (suom. Kauneudesta). Tutkimuksen tarkoitus on osoittaa kuinka oleellisesti intertekstuaalisuuden teoria on vaikuttanut kirjallisuustieteen metodeihin ja postmoderniin kirjallisuuskäsitykseen, sekä käsitellä sen soveltuvuutta nykykirjallisuuden tutkimiseen analysoimalla teorian sisäistä monimuotoisuutta ja ristiriitoja.
Tutkimusmateriaalina käytetään Smithin romaanin lisäksi E. M. Forsterin romaania Howards End (suom. Talo jalavan varjossa), johon On Beauty tietoisesti viittaa. Teoreettisena viitekehyksenä tutkielmassa toimii Gérard Genetten teoksessa Palimpsests sekä Roland Barthesin esseessä Tekijän kuolema esille tuodut kirjallisuusteoreettiset käsitykset. Valittu metodologia antaa mahdollisuuden hahmottaa intertekstuaalisuus kahdella eri tavalla: Genetten strukturalistinen lähestymistapa soveltuu teosten välisten viittaussuhteiden tutkimiseen, kun taas Barthesin jälkistrukturalistinen diskurssi auttaa ymmärtämään tekstienvälisyyden osana merkityksen jatkuvaa epävakautta.
Tutkielman ensimmäinen osio keskittyy analysoimaan lähiluvun keinoin romaanien On Beauty ja Howards End välistä strukturalistista suhdetta vertailemalla teosten eroja ja yhtäläisyyksiä Genetten intertekstuaalisuusteorian valossa. Vertailussa kiinnetetään erityisesti huomiota teosten juoneen, rakenteeseen, aikaan ja paikkaan, sekä uudelleenkirjoitusten yleiseen tendenssiin päivittää alkuperäistä tarinaa kohdeyleisölle paremmin sopivaksi. Toisessa osiossa tutkimusta esille nousee jälkistrukturalistinen näkemys intertekstuaalisuudesta osana lukijan tuottaman merkityksen tulkinnanvaraisuutta. Osiossa käsitellään Rembrandtin taideteosten roolia Smithin romaanissa ja analysoidaan hahmojen tulkintoja sekä suhtautumista Rembrandtin tuotantoon Barthesin teoreettisten käsitteiden kautta. Keskeiseksi analyysin kohteeksi nousee lukija sekä lukijan tuottamat tulkinnat ja niiden merkitys Smithin romaanin tematiikassa.
Tutkielmassa osoitetaan kuinka intertekstuaalisuus ei ole niin yksinkertainen termi kuin sen laaja käyttö niin kirjallisuustieteessä kuin mediassakin antaa ymmärtää, sekä selvitetään intertekstuaalisuuden teorian kehitystä 60-luvulta nykypäivään. Vaikka strukturalistisessa muodossa käsite soveltuu etenkin kahden toisiinsa kytkeytyneen teoksen tutkimiseen, vertaileva analyysi kuitenkin osoittaa, että On Beauty ei ole pelkkä uudelleenkirjoitus, vaan romaanin tulkintaan tarvitaan myös jälkistrukturalistisen dekonstruktion käsitteitä, jotta laajemmat tekstuaalisuuden verkostot aukeavat lukijalle. Romaanissa esiintyvä taitelijakuva myös osoittaa, että Smith itse on hyvin tietoinen kirjallisuusteoreettisesta keskustelusta
Improving the diagnosis and management of Lewy body dementia: the DIAMOND-Lewy research programme including pilot cluster RCT
Background:
Lewy body dementia, comprising both dementia with Lewy bodies and Parkinson’s disease dementia, is the second commonest cause of neurodegenerative dementia. Existing evidence suggests that it is underdiagnosed and without a consistent approach to management.
Objectives:
To improve the diagnosis and management of Lewy body dementia by (1) understanding current diagnostic practice for dementia with Lewy bodies and Parkinson’s disease dementia; (2) identifying barriers to and facilitators of diagnosis and management; (3) developing evidence-based assessment toolkits to improve diagnosis of dementia with Lewy bodies and Parkinson’s disease dementia; (4) producing a management toolkit to facilitate management; and (5) undertaking a pilot cluster randomised clinical trial.
Design:
Work package 1 assessed clinical diagnostic rates from case notes for dementia with Lewy bodies and Parkinson’s disease dementia before and after (work package 1 repeated) introduction of an assessment toolkit. In work package 2, we developed a management toolkit for Lewy body dementia. In work package 3, we developed assessment toolkits for dementia with Lewy bodies and Parkinson’s disease dementia and piloted these and the management toolkit in a clinical service. In work package 4, we undertook a pilot study of 23 services in nine NHS trusts that were cluster randomised to receiving and using the management toolkit or standard care. Work package 5 comprised a series of qualitative studies, examining barriers to and facilitators of diagnosis and management.
Setting:
Secondary care memory assessment and movement disorder services in England.
Interventions:
Assessment toolkits for Lewy body dementia consisted of questions for diagnostic symptoms, and management toolkits comprised 161 guidance statements grouped under five symptom domains.
Review methods:
The systematic reviews of pharmacological and non-pharmacological management were based on published literature, with meta-analysis when possible, following a search of several electronic databases and the grey literature using terms related to Lewy body dementia, without restriction on time or language.
Participants:
Participants aged ≥ 50 years diagnosed with dementia with Lewy bodies or Parkinson’s disease dementia and, for work package 1 and work package 1 repeated, non-dementia with Lewy bodies and non-Parkinson’s disease dementia controls. The qualitative studies included people with Lewy body dementia, carers and professionals.
Main outcome measures:
For work packages 1 and 1 repeated, diagnostic rates for dementia with Lewy bodies and Parkinson’s disease dementia as a proportion of all dementia or Parkinson’s disease. For work packages 2 and 3, the production of diagnostic and management toolkits. For work package 4, feasibility of undertaking a cluster randomised trial of the toolkits, measured by number of participants recruited and use of the toolkits, assessed qualitatively.
Results:
Work package 1 – 4.6% of dementia cases in secondary care received a dementia with Lewy bodies diagnosis (with significant differences in diagnostic rates between services) and 9.7% of those with Parkinson’s disease had a diagnosis of Parkinson’s disease dementia. There was evidence of delays in diagnosis for both dementia with Lewy bodies and Parkinson’s disease dementia compared with control patients, and the costs of dementia with Lewy bodies and Parkinson’s disease dementia were also greater than those for matched controls (p < 0.01 for both). Work package 2 – we produced 252 statements regarding Lewy body dementia management and, following a Delphi process, 161 statements were included in a management toolkit. Work package 3 – piloting indicated that separate assessment toolkits for use in memory clinic and movement disorder services were preferred, but a single toolkit for Lewy body dementia management was suitable. Work package 4 – we were able to recruit Lewy body dementia patients to target and recruited 131 patients within 6 months (target n = 120), of whom > 80% were retained in the study at 6 months. Work package 5 – barriers to diagnosis and management of Lewy body dementia were complex. Managing Lewy body dementia often requires input from a range of specialties and, therefore, care pathways may be fragmented. Positive attitudes to diagnosing Lewy body dementia, working with a team with expertise in Lewy body dementia and opportunities for cross-specialty discussion of patients with complex needs facilitated diagnosis and management. The toolkits were generally well received, particularly the management toolkit. Implementation, however, varied, reflecting differences in attitudes, skills, time and local leadership. Work package 1 repeated – following introduction of the assessment toolkit, we found that 9.7% of dementia cases had dementia with Lewy bodies (a significant increase from baseline; p = 0.0019), but Parkinson’s disease dementia rates were similar (8.2%) to baseline.
Limitations:
We included only two geographical regions and evidence informing the management toolkit was limited. Work package 4 was a pilot study and, therefore, we did not set out to assess the extent to which use of the management toolkit altered outcomes at the individual patient level. We noted implementation of the toolkits was variable. The increase in diagnostic rates in dementia with Lewy bodies following introduction of the assessment toolkits cannot be necessarily causally attributed to them.
Conclusions:
Dementia with Lewy bodies and Parkinson’s disease dementia were diagnosed in secondary care NHS services, with a lower frequency (around half) than that expected from known prevalence rates. The introduction of assessment toolkits for dementia with Lewy bodies and Parkinson’s disease dementia was associated with increased diagnostic rates of dementia with Lewy bodies, but not Parkinson’s disease dementia. Qualitative studies indicated inherent complexities of the disease itself, with treatment requiring input from different specialties and the potential for fragmented services, a workforce with variable training and confidence in Lewy body dementia, and negative attitudes towards diagnosis. The cluster randomised pilot trial demonstrated that patients could be successfully recruited, and provided preliminary evidence that the toolkits could be implemented in clinical services.
Future work:
The evidence base informing the management of Lewy body dementia is limited, especially for non-pharmacological interventions. More well-designed randomised controlled trials for both cognitive and non-cognitive symptoms are needed.
Trial registration:
Current Controlled Trials ISRCTN11083027.
Funding:
This project was funded by the National Institute for Health Research (NIHR) Programme Grants for Applied Research programme and will be published in full in Programme Grants for Applied Research; Vol. 9, No. 7. See the NIHR Journals Library website for further project information
Improving the diagnosis and management of Lewy body dementia: the DIAMOND-Lewy research programme including pilot cluster RCT
Background
Lewy body dementia, comprising both dementia with Lewy bodies and Parkinson’s disease dementia, is the second commonest cause of neurodegenerative dementia. Existing evidence suggests that it is underdiagnosed and without a consistent approach to management.
Objectives
To improve the diagnosis and management of Lewy body dementia by (1) understanding current diagnostic practice for dementia with Lewy bodies and Parkinson’s disease dementia; (2) identifying barriers to and facilitators of diagnosis and management; (3) developing evidence-based assessment toolkits to improve diagnosis of dementia with Lewy bodies and Parkinson’s disease dementia; (4) producing a management toolkit to facilitate management; and (5) undertaking a pilot cluster randomised clinical trial.
Design
Work package 1 assessed clinical diagnostic rates from case notes for dementia with Lewy bodies and Parkinson’s disease dementia before and after (work package 1 repeated) introduction of an assessment toolkit. In work package 2, we developed a management toolkit for Lewy body dementia. In work package 3, we developed assessment toolkits for dementia with Lewy bodies and Parkinson’s disease dementia and piloted these and the management toolkit in a clinical service. In work package 4, we undertook a pilot study of 23 services in nine NHS trusts that were cluster randomised to receiving and using the management toolkit or standard care. Work package 5 comprised a series of qualitative studies, examining barriers to and facilitators of diagnosis and management.
Setting
Secondary care memory assessment and movement disorder services in England.
Interventions
Assessment toolkits for Lewy body dementia consisted of questions for diagnostic symptoms, and management toolkits comprised 161 guidance statements grouped under five symptom domains.
Review methods
The systematic reviews of pharmacological and non-pharmacological management were based on published literature, with meta-analysis when possible, following a search of several electronic databases and the grey literature using terms related to Lewy body dementia, without restriction on time or language.
Participants
Participants aged ≥ 50 years diagnosed with dementia with Lewy bodies or Parkinson’s disease dementia and, for work package 1 and work package 1 repeated, non-dementia with Lewy bodies and non-Parkinson’s disease dementia controls. The qualitative studies included people with Lewy body dementia, carers and professionals.
Main outcome measures
For work packages 1 and 1 repeated, diagnostic rates for dementia with Lewy bodies and Parkinson’s disease dementia as a proportion of all dementia or Parkinson’s disease. For work packages 2 and 3, the production of diagnostic and management toolkits. For work package 4, feasibility of undertaking a cluster randomised trial of the toolkits, measured by number of participants recruited and use of the toolkits, assessed qualitatively.
Results
Work package 1 – 4.6% of dementia cases in secondary care received a dementia with Lewy bodies diagnosis (with significant differences in diagnostic rates between services) and 9.7% of those with Parkinson’s disease had a diagnosis of Parkinson’s disease dementia. There was evidence of delays in diagnosis for both dementia with Lewy bodies and Parkinson’s disease dementia compared with control patients, and the costs of dementia with Lewy bodies and Parkinson’s disease dementia were also greater than those for matched controls (p 80% were retained in the study at 6 months. Work package 5 – barriers to diagnosis and management of Lewy body dementia were complex. Managing Lewy body dementia often requires input from a range of specialties and, therefore, care pathways may be fragmented. Positive attitudes to diagnosing Lewy body dementia, working with a team with expertise in Lewy body dementia and opportunities for cross-specialty discussion of patients with complex needs facilitated diagnosis and management. The toolkits were generally well received, particularly the management toolkit. Implementation, however, varied, reflecting differences in attitudes, skills, time and local leadership. Work package 1 repeated – following introduction of the assessment toolkit, we found that 9.7% of dementia cases had dementia with Lewy bodies (a significant increase from baseline; p = 0.0019), but Parkinson’s disease dementia rates were similar (8.2%) to baseline.
Limitations
We included only two geographical regions and evidence informing the management toolkit was limited. Work package 4 was a pilot study and, therefore, we did not set out to assess the extent to which use of the management toolkit altered outcomes at the individual patient level. We noted implementation of the toolkits was variable. The increase in diagnostic rates in dementia with Lewy bodies following introduction of the assessment toolkits cannot be necessarily causally attributed to them.
Conclusions
Dementia with Lewy bodies and Parkinson’s disease dementia were diagnosed in secondary care NHS services, with a lower frequency (around half) than that expected from known prevalence rates. The introduction of assessment toolkits for dementia with Lewy bodies and Parkinson’s disease dementia was associated with increased diagnostic rates of dementia with Lewy bodies, but not Parkinson’s disease dementia. Qualitative studies indicated inherent complexities of the disease itself, with treatment requiring input from different specialties and the potential for fragmented services, a workforce with variable training and confidence in Lewy body dementia, and negative attitudes towards diagnosis. The cluster randomised pilot trial demonstrated that patients could be successfully recruited, and provided preliminary evidence that the toolkits could be implemented in clinical services.
Future work
The evidence base informing the management of Lewy body dementia is limited, especially for non-pharmacological interventions. More well-designed randomised controlled trials for both cognitive and non-cognitive symptoms are needed
Effects of antiplatelet therapy on stroke risk by brain imaging features of intracerebral haemorrhage and cerebral small vessel diseases: subgroup analyses of the RESTART randomised, open-label trial
Background
Findings from the RESTART trial suggest that starting antiplatelet therapy might reduce the risk of recurrent symptomatic intracerebral haemorrhage compared with avoiding antiplatelet therapy. Brain imaging features of intracerebral haemorrhage and cerebral small vessel diseases (such as cerebral microbleeds) are associated with greater risks of recurrent intracerebral haemorrhage. We did subgroup analyses of the RESTART trial to explore whether these brain imaging features modify the effects of antiplatelet therapy
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Hospital Readmissions Among Persons With Human Immunodeficiency Virus in the United States and Canada, 2005–2018: A Collaboration of Cohort Studies
BackgroundHospital readmission trends for persons with human immunodeficiency virus (PWH) in North America in the context of policy changes, improved antiretroviral therapy (ART), and aging are not well-known. We examined readmissions during 2005-2018 among adult PWH in NA-ACCORD.MethodsLinear risk regression estimated calendar trends in 30-day readmissions, adjusted for demographics, CD4 count, AIDS history, virologic suppression (<400 copies/mL), and cohort.ResultsWe examined 20 189 hospitalizations among 8823 PWH (73% cisgender men, 38% White, 38% Black). PWH hospitalized in 2018 versus 2005 had higher median age (54 vs 44 years), CD4 count (469 vs 274 cells/μL), and virologic suppression (83% vs 49%). Unadjusted 30-day readmissions decreased from 20.1% (95% confidence interval [CI], 17.9%-22.3%) in 2005 to 16.3% (95% CI, 14.1%-18.5%) in 2018. Absolute annual trends were -0.34% (95% CI, -.48% to -.19%) in unadjusted and -0.19% (95% CI, -.35% to -.02%) in adjusted analyses. By index hospitalization reason, there were significant adjusted decreases only for cardiovascular and psychiatric hospitalizations. Readmission reason was most frequently in the same diagnostic category as the index hospitalization.ConclusionsReadmissions decreased over 2005-2018 but remained higher than the general population's. Significant decreases after adjusting for CD4 count and virologic suppression suggest that factors alongside improved ART contributed to lower readmissions. Efforts are needed to further prevent readmissions in PWH
Effects of antiplatelet therapy after stroke due to intracerebral haemorrhage (RESTART): a randomised, open-label trial
Background:
Antiplatelet therapy reduces the risk of major vascular events for people with occlusive vascular disease, although it might increase the risk of intracranial haemorrhage. Patients surviving the commonest subtype of intracranial haemorrhage, intracerebral haemorrhage, are at risk of both haemorrhagic and occlusive vascular events, but whether antiplatelet therapy can be used safely is unclear. We aimed to estimate the relative and absolute effects of antiplatelet therapy on recurrent intracerebral haemorrhage and whether this risk might exceed any reduction of occlusive vascular events.
Methods:
The REstart or STop Antithrombotics Randomised Trial (RESTART) was a prospective, randomised, open-label, blinded endpoint, parallel-group trial at 122 hospitals in the UK. We recruited adults (≥18 years) who were taking antithrombotic (antiplatelet or anticoagulant) therapy for the prevention of occlusive vascular disease when they developed intracerebral haemorrhage, discontinued antithrombotic therapy, and survived for 24 h. Computerised randomisation incorporating minimisation allocated participants (1:1) to start or avoid antiplatelet therapy. We followed participants for the primary outcome (recurrent symptomatic intracerebral haemorrhage) for up to 5 years. We analysed data from all randomised participants using Cox proportional hazards regression, adjusted for minimisation covariates. This trial is registered with ISRCTN (number ISRCTN71907627).
Findings:
Between May 22, 2013, and May 31, 2018, 537 participants were recruited a median of 76 days (IQR 29–146) after intracerebral haemorrhage onset: 268 were assigned to start and 269 (one withdrew) to avoid antiplatelet therapy. Participants were followed for a median of 2·0 years (IQR [1·0– 3·0]; completeness 99·3%). 12 (4%) of 268 participants allocated to antiplatelet therapy had recurrence of intracerebral haemorrhage compared with 23 (9%) of 268 participants allocated to avoid antiplatelet therapy (adjusted hazard ratio 0·51 [95% CI 0·25–1·03]; p=0·060). 18 (7%) participants allocated to antiplatelet therapy experienced major haemorrhagic events compared with 25 (9%) participants allocated to avoid antiplatelet therapy (0·71 [0·39–1·30]; p=0·27), and 39 [15%] participants allocated to antiplatelet therapy had major occlusive vascular events compared with 38 [14%] allocated to avoid antiplatelet therapy (1·02 [0·65–1·60]; p=0·92).
Interpretation:
These results exclude all but a very modest increase in the risk of recurrent intracerebral haemorrhage with antiplatelet therapy for patients on antithrombotic therapy for the prevention of occlusive vascular disease when they developed intracerebral haemorrhage. The risk of recurrent intracerebral haemorrhage is probably too small to exceed the established benefits of antiplatelet therapy for secondary prevention
Effects of antiplatelet therapy after stroke due to intracerebral haemorrhage (RESTART): a randomised, open-label trial
Background:
Antiplatelet therapy reduces the risk of major vascular events for people with occlusive vascular disease, although it might increase the risk of intracranial haemorrhage. Patients surviving the commonest subtype of intracranial haemorrhage, intracerebral haemorrhage, are at risk of both haemorrhagic and occlusive vascular events, but whether antiplatelet therapy can be used safely is unclear. We aimed to estimate the relative and absolute effects of antiplatelet therapy on recurrent intracerebral haemorrhage and whether this risk might exceed any reduction of occlusive vascular events.
Methods:
The REstart or STop Antithrombotics Randomised Trial (RESTART) was a prospective, randomised, open-label, blinded endpoint, parallel-group trial at 122 hospitals in the UK. We recruited adults (≥18 years) who were taking antithrombotic (antiplatelet or anticoagulant) therapy for the prevention of occlusive vascular disease when they developed intracerebral haemorrhage, discontinued antithrombotic therapy, and survived for 24 h. Computerised randomisation incorporating minimisation allocated participants (1:1) to start or avoid antiplatelet therapy. We followed participants for the primary outcome (recurrent symptomatic intracerebral haemorrhage) for up to 5 years. We analysed data from all randomised participants using Cox proportional hazards regression, adjusted for minimisation covariates. This trial is registered with ISRCTN (number ISRCTN71907627).
Findings:
Between May 22, 2013, and May 31, 2018, 537 participants were recruited a median of 76 days (IQR 29–146) after intracerebral haemorrhage onset: 268 were assigned to start and 269 (one withdrew) to avoid antiplatelet therapy. Participants were followed for a median of 2·0 years (IQR [1·0– 3·0]; completeness 99·3%). 12 (4%) of 268 participants allocated to antiplatelet therapy had recurrence of intracerebral haemorrhage compared with 23 (9%) of 268 participants allocated to avoid antiplatelet therapy (adjusted hazard ratio 0·51 [95% CI 0·25–1·03]; p=0·060). 18 (7%) participants allocated to antiplatelet therapy experienced major haemorrhagic events compared with 25 (9%) participants allocated to avoid antiplatelet therapy (0·71 [0·39–1·30]; p=0·27), and 39 [15%] participants allocated to antiplatelet therapy had major occlusive vascular events compared with 38 [14%] allocated to avoid antiplatelet therapy (1·02 [0·65–1·60]; p=0·92).
Interpretation:
These results exclude all but a very modest increase in the risk of recurrent intracerebral haemorrhage with antiplatelet therapy for patients on antithrombotic therapy for the prevention of occlusive vascular disease when they developed intracerebral haemorrhage. The risk of recurrent intracerebral haemorrhage is probably too small to exceed the established benefits of antiplatelet therapy for secondary prevention