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1.
J Palliat Care ; 38(3): 282-294, 2023 Jul.
Article in English | MEDLINE | ID: mdl-37340793

ABSTRACT

Objective: This study explored the perspectives of specialist palliative care (SPC) teams in Ireland, in relation to personal learning needs and education regarding dementia care. Methods: This mixed-methods study involved a survey and focus group. SPC staff were recruited through a professional palliative care society and via hospices in 4 regions. Survey items included challenges in clinical care, personal learning needs, and preferred modes of educational delivery. Quantitative data analysis was descriptive; open-answer survey questions and the focus group transcript underwent thematic analysis. Results: In total, 76 staff completed surveys and rated the following as most challenging: timely access to community agency and specialist support; and managing the needs of people with dementia (PwD). Respondents volunteered additional challenges around the timing/duration of SPC involvement, prognostication, and inadequate knowledge of local services. Staff ranked learning needs as highest in: nonpharmacological management of noncognitive and cognitive symptoms; differentiation of dementia subtypes; and pharmacological management of cognitive symptoms. The focus group (n = 4) gave deeper perspectives on these topics. Overall, 79.2% of staff preferred formal presentations by dementia-care specialists and 76.6% preferred e-learning. Conclusion: Several dementia-care challenges and learning needs are identified by SPC staff, as above. These can inform the design and delivery of tailored education programs for SPC staff. There is also a need for closer working between dementia services and SPC services to provide integrated, holistic care for PwD. One aspect of achieving this is greater awareness of local dementia-care services among SPC staff, and vice versa.


Subject(s)
Dementia , Hospice Care , Hospice and Palliative Care Nursing , Hospices , Humans , Palliative Care , Dementia/therapy
2.
Cancer Immunol Immunother ; 72(7): 2099-2111, 2023 Jul.
Article in English | MEDLINE | ID: mdl-36823323

ABSTRACT

Bempegaldesleukin (BEMPEG), a CD122-preferential IL2 pathway agonist, has been shown to induce proliferation and activation of NK cells. NK activation is dependent on the balance of inhibitory and excitatory signals transmitted by NK receptors, including Fc-gamma receptors (FCγRs) and killer immunoglobulin-like receptors (KIRs) along with their KIR-ligands. The repertoire of KIRs/KIR-ligands an individual inherits and the single-nucleotide polymorphisms (SNPs) of FCγRs can influence NK function and affect responses to immunotherapies. In this retrospective analysis of the single-arm PIVOT-02 trial, 200 patients with advanced solid tumors were genotyped for KIR/KIR-ligand gene status and FCγR SNP status and evaluated for associations with clinical outcome. Patients with inhibitory KIR2DL2 and its ligand (HLA-C1) observed significantly greater tumor shrinkage (TS, median change -13.0 vs. 0%) and increased PFS (5.5 vs. 3.3 months) and a trend toward improved OR (31.2 vs. 19.5%) compared to patients with the complementary genotype. Furthermore, patients with KIR2DL2 and its ligand together with inhibitory KIR3DL1 and its ligand (HLA-Bw4) had improved OR (36.5 vs. 19.6%), greater TS (median change -16.1 vs. 0%), and a trend toward prolonged PFS (8.4 vs. 3.6 months) as compared to patients with the complementary genotype. FCγR polymorphisms did not influence OR/PFS/TS.These data show that clinical response to BEMPEG plus nivolumab treatment in the PIVOT-02 trial may be associated with the repertoire of KIR/KIR-ligands an individual inherits. Further investigation and validation of these results may enable KIR/KIR-ligand genotyping to be utilized prospectively for identifying patients likely to benefit from certain cancer immunotherapy regimens.


Subject(s)
Neoplasms , Nivolumab , Humans , Nivolumab/therapeutic use , Ligands , Retrospective Studies , Receptors, IgG/genetics , Receptors, KIR/genetics , Receptors, KIR/metabolism , Genotype , Polymorphism, Single Nucleotide , Neoplasms/drug therapy , Neoplasms/genetics
3.
Phys Rev Lett ; 127(16): 162501, 2021 Oct 15.
Article in English | MEDLINE | ID: mdl-34723594

ABSTRACT

We report an improved measurement of the free neutron lifetime τ_{n} using the UCNτ apparatus at the Los Alamos Neutron Science Center. We count a total of approximately 38×10^{6} surviving ultracold neutrons (UCNs) after storing in UCNτ's magnetogravitational trap over two data acquisition campaigns in 2017 and 2018. We extract τ_{n} from three blinded, independent analyses by both pairing long and short storage time runs to find a set of replicate τ_{n} measurements and by performing a global likelihood fit to all data while self-consistently incorporating the ß-decay lifetime. Both techniques achieve consistent results and find a value τ_{n}=877.75±0.28_{stat}+0.22/-0.16_{syst} s. With this sensitivity, neutron lifetime experiments now directly address the impact of recent refinements in our understanding of the standard model for neutron decay.

4.
Rev Sci Instrum ; 92(2): 023305, 2021 Feb 01.
Article in English | MEDLINE | ID: mdl-33648127

ABSTRACT

In this paper, we report studies of the Fermi potential and loss per bounce of ultracold neutrons (UCNs) on a deuterated scintillator (Eljen-299-02D). These UCN properties of the scintillator enable its use in a wide variety of applications in fundamental neutron research.

5.
Clin Radiol ; 76(1): 78.e9-78.e17, 2021 01.
Article in English | MEDLINE | ID: mdl-33036778

ABSTRACT

AIM: To determine whether machine learning-based radiomic feature analysis of baseline integrated 2-[18F]-fluoro-2-deoxy-d-glucose (FDG) positron-emission tomography (PET) computed tomography (CT) predicts disease progression in patients with locally advanced larynx and hypopharynx squamous cell carcinoma (SCC) receiving (chemo)radiotherapy. MATERIALS AND METHODS: Patients with larynx and hypopharynx SCC treated with definitive (chemo)radiotherapy at a specialist cancer centre undergoing pre-treatment PET-CT between 2008 and 2017 were included. Tumour segmentation and radiomic analysis was performed using LIFEx software (University of Paris-Saclay, France). Data were assigned into training (80%) and validation (20%) cohorts adhering to TRIPOD guidelines. A random forest classifier was created for four predictive models using features determined by recursive feature elimination: (A) PET, (B) CT, (C) clinical, and (D) combined PET-CT parameters. Model performance was assessed using area under the curve (AUC) receiver operating characteristic (ROC) analysis. RESULTS: Seventy-two patients (40 hypopharynx 32 larynx tumours) were included, mean age 61 (range 41-77) years, 50 (69%) were men. Forty-five (62.5%) had chemoradiotherapy, 27 (37.5%) had radiotherapy alone. Median follow-up 26 months (range 12-105 months). Twenty-seven (37.5%) patients progressed within 12 months. ROC AUC for models A, B, C, and D were 0.91, 0.94, 0.88, and 0.93 in training and 0.82, 0.72, 0.70, and 0.94 in validation cohorts. Parameters in model D were metabolic tumour volume (MTV), maximum CT value, minimum standardized uptake value (SUVmin), grey-level zone length matrix (GLZLM) small-zone low grey-level emphasis (SZLGE) and histogram kurtosis. CONCLUSION: FDG PET-CT derived radiomic features are potential predictors of early disease progression in patients with locally advanced larynx and hypopharynx SCC.


Subject(s)
Carcinoma, Squamous Cell/diagnostic imaging , Carcinoma, Squamous Cell/pathology , Laryngeal Neoplasms/diagnostic imaging , Laryngeal Neoplasms/pathology , Machine Learning , Positron Emission Tomography Computed Tomography , Adult , Aged , Carcinoma, Squamous Cell/therapy , Chemoradiotherapy , Female , Fluorodeoxyglucose F18 , Humans , Hypopharynx/diagnostic imaging , Hypopharynx/pathology , Laryngeal Neoplasms/therapy , Male , Middle Aged , Neoplasm Recurrence, Local , Predictive Value of Tests , Radiopharmaceuticals
6.
Clin Oncol (R Coll Radiol) ; 32(4): 250-258, 2020 04.
Article in English | MEDLINE | ID: mdl-31607611

ABSTRACT

AIMS: Stereotactic ablative body radiotherapy doses for peripheral lung lesions caused high toxicity when used for central non-small cell lung cancer (NSCLC). To determine a safe stereotactic ablative body radiotherapy dose for central tumours, the phase I/II Radiation Therapy Oncology Group RTOG 0813 trial used 50 Gy/five fractions as a baseline. From 2013, 50 Gy/five fractions was adopted at the Beatson West of Scotland Cancer Centre for inoperable early stage central NSCLC. We report our prospectively collected toxicity and efficacy data. MATERIALS AND METHODS: Patient and treatment characteristics were obtained from electronic medical records. Tumours were classed as moderately central or ultra-central tumours using published definitions. Toxicity was assessed in a centralised follow-up clinic at 2 weeks, 6 weeks, 3 months, 6 months, 1 year and 2 years after treatment. RESULTS: Fifty patients (31 women, 19 men, median age 75.1 years) were identified with T1-2N0M0 moderately central NSCLC; one patient had both an ultra-central and a moderately central tumour. Eighty-four per cent were medically unfit for surgery. Forty per cent had biopsy-proven NSCLC and 60% were diagnosed radiologically using 18-fluorodeoxyglucose positron emission tomography/computed tomography imaging. Fifty-six per cent of patients were Eastern Cooperative Oncology Group (ECOG) performance status 2 or worse. All patients received 50 Gy/five fractions on alternate days on schedule. Two patients died within 90 days of treatment, one from a chest infection, the other cause of death was unknown. There was one episode of early grade 3 oesophagitis and one grade 3 late dyspnoea. There was no grade 4 toxicity. Over a median follow-up of 25.2 months (range 1-70 months), there were 34 deaths: 18 unrelated to cancer and 16 due to cancer recurrence. The median overall survival was 27.0 months (95% confidence interval 20.6-35.9) and cancer-specific survival was 39.8 months (95% confidence interval 28.6, not reached). CONCLUSION: This study has shown that 50 Gy/five fractions is a safe dose and fractionation for early stage inoperable moderately central NSCLC, with outcomes comparable with other series, even with patients with a poor performance status.


Subject(s)
Carcinoma, Non-Small-Cell Lung/radiotherapy , Lung Neoplasms/radiotherapy , Radiosurgery/methods , Aged , Aged, 80 and over , Carcinoma, Non-Small-Cell Lung/pathology , Dose Fractionation, Radiation , Female , Humans , Lung Neoplasms/pathology , Male , Middle Aged , Prospective Studies
7.
Eur J Nucl Med Mol Imaging ; 46(13): 2790-2799, 2019 Dec.
Article in English | MEDLINE | ID: mdl-31482428

ABSTRACT

PURPOSE: Incidence of anal squamous cell carcinoma (ASCC) is increasing, with curative chemoradiotherapy (CRT) as the primary treatment of non-metastatic disease. A significant proportion of patients have locoregional treatment failure (LRF), but distant relapse is uncommon. Accurate prognostication of progression-free survival (PFS) would help personalisation of CRT regimens. The study aim was to evaluate novel imaging pre-treatment features, to prognosticate for PFS in ASCC. METHODS: Consecutive patients with ASCC treated with curative intent at a large tertiary referral centre who underwent pre-treatment FDG-PET/CT were included. Radiomic feature extraction was performed using LIFEx software on baseline FDG-PET/CT. Outcome data (PFS) was collated from electronic patient records. Elastic net regularisation and feature selection were used for logistic regression model generation on a randomly selected training cohort and applied to a validation cohort using TRIPOD guidelines. ROC-AUC analysis was used to compare performance of a regression model encompassing standard clinical prognostic factors (age, sex, tumour and nodal stage-model A), a radiomic feature model (model B) and a combined radiomic/clinical model (model C). RESULTS: A total of 189 patients were included in the study, with 145 in the training cohort and 44 in the validation cohort. Median follow-up was 35.1 and 37. 9 months, respectively for each cohort, with 70.3% and 68.2% reaching this time-point with PFS. GLCM entropy (a measure of randomness of distribution of co-occurring pixel grey-levels), NGLDM busyness (a measure of spatial frequency of changes in intensity between nearby voxels of different grey-level), minimum CT value (lowest HU within the lesion) and SMTV (a standardized version of MTV) were selected for inclusion in the prognostic model, alongside tumour and nodal stage. AUCs for performance of model A (clinical), B (radiomic) and C (radiomic/clinical) were 0.6355, 0.7403, 0.7412 in the training cohort and 0.6024, 0.6595, 0.7381 in the validation cohort. CONCLUSION: Radiomic features extracted from pre-treatment FDG-PET/CT in patients with ASCC may provide better PFS prognosis than conventional staging parameters. With external validation, this might be useful to help personalise CRT regimens in the future.


Subject(s)
Anus Neoplasms/diagnostic imaging , Carcinoma, Squamous Cell/diagnostic imaging , Fluorodeoxyglucose F18 , Image Processing, Computer-Assisted , Positron Emission Tomography Computed Tomography , Anus Neoplasms/therapy , Carcinoma, Squamous Cell/therapy , Disease-Free Survival , Female , Humans , Kaplan-Meier Estimate , Male , Middle Aged , Retrospective Studies
8.
Phys Rev Lett ; 121(2): 022505, 2018 Jul 13.
Article in English | MEDLINE | ID: mdl-30085691

ABSTRACT

Fornal and Grinstein recently proposed that the discrepancy between two different methods of neutron lifetime measurements, the beam and bottle methods, can be explained by a previously unobserved dark matter decay mode, n→X+γ. We perform a search for this decay mode over the allowed range of energies of the monoenergetic γ ray for X to be dark matter. A Compton-suppressed high-purity germanium detector is used to identify γ rays from neutron decay in a nickel-phosphorous-coated stainless-steel bottle. A combination of Monte Carlo and radioactive source calibrations is used to determine the absolute efficiency for detecting γ rays arising from the dark matter decay mode. We exclude the possibility of a sufficiently strong branch to explain the lifetime discrepancy with 97% confidence.

9.
Clin Radiol ; 73(11): 944-950, 2018 11.
Article in English | MEDLINE | ID: mdl-30025590

ABSTRACT

AIM: To determine the level of confidence general practitioners (GPs) have in radiology reports provided by neuroradiologists and to elicit the preferences of GPs regarding report format and level of detail. MATERIALS AND METHODS: Electronic surveys comprising anonymised neuroradiology reports were sent to GP practices served by a tertiary neuroscience centre. After reviewing the reports, GPs were asked to complete a two-part questionnaire. Firstly, GPs indicated their level of confidence, using a five-tiered Likert scale, in their understanding of: (a) the body of text; (b) the meaning of the report; and (c) the significance of the report. Secondly, GPs provided free-text suggestions for improving the report and highlighted any phrases that they did not understand. RESULTS: One hundred GPs responded from a group of 439 that received a survey (response rate 23%). Although the majority of GPs were fairly confident in their understanding of reports, fewer than one-third of GPs were entirely confident. Approximately 10% of GPs were not confident at all in their understanding of the reports. Causes of confusion included the use of detailed anatomy, acronyms, radiological terminology, and a lack of a conclusion and an action plan. CONCLUSION: General practice is a time-sensitive discipline that demands clear communication. In neuroradiology reports, GPs do not find detailed anatomy, acronyms, or radiological terminology helpful. Rather, GPs want a clear conclusion and action plan.


Subject(s)
General Practitioners , Magnetic Resonance Imaging , Neuroimaging , Attitude of Health Personnel , Brain/diagnostic imaging , Brain Diseases/diagnostic imaging , Documentation/standards , General Practitioners/psychology , General Practitioners/statistics & numerical data , Humans , Magnetic Resonance Imaging/methods , Magnetic Resonance Imaging/standards , Magnetic Resonance Imaging/statistics & numerical data , Neuroimaging/standards , Neuroimaging/statistics & numerical data , Surveys and Questionnaires , Terminology as Topic
10.
Science ; 360(6389): 627-632, 2018 05 11.
Article in English | MEDLINE | ID: mdl-29731449

ABSTRACT

The precise value of the mean neutron lifetime, τn, plays an important role in nuclear and particle physics and cosmology. It is used to predict the ratio of protons to helium atoms in the primordial universe and to search for physics beyond the Standard Model of particle physics. We eliminated loss mechanisms present in previous trap experiments by levitating polarized ultracold neutrons above the surface of an asymmetric storage trap using a repulsive magnetic field gradient so that the stored neutrons do not interact with material trap walls. As a result of this approach and the use of an in situ neutron detector, the lifetime reported here [877.7 ± 0.7 (stat) +0.4/-0.2 (sys) seconds] does not require corrections larger than the quoted uncertainties.

11.
Obes Rev ; 19(7): 947-959, 2018 07.
Article in English | MEDLINE | ID: mdl-29573123

ABSTRACT

Breastfeeding can play a key role in the reduction of obesity, but initiation and maintenance rates in women with a body mass index (BMI) of ≥30 kg m-2 are low. Psychological factors influence breastfeeding behaviours in the general population, but their role is not yet understood in women with a BMI ≥30 kg m-2 . Therefore, this review aimed to systematically search and synthesize the literature, which has investigated the association between any psychological factor and breastfeeding behaviour in women with a BMI ≥30 kg m-2 . The search identified 20 eligible papers, reporting 16 psychological factors. Five psychological factors were associated with breastfeeding behaviours: intentions to breastfeed, belief in breast milk's nutritional adequacy and sufficiency, belief about other's infant feeding preferences, body image and social knowledge. It is therefore recommended that current care should encourage women to plan to breastfeed, provide corrective information for particular beliefs and address their body image and social knowledge. Recommendations for future research include further exploration of several psychological factors (i.e. expecting that breastfeeding will enhance weight loss, depression, anxiety and stress) and evidence and theory-based intervention development.


Subject(s)
Body Mass Index , Breast Feeding/psychology , Maternal Behavior/psychology , Mothers/psychology , Obesity/psychology , Body Image/psychology , Breast Feeding/statistics & numerical data , Female , Health Knowledge, Attitudes, Practice , Humans , Intention , Weight Loss
12.
Clin Transl Radiat Oncol ; 8: 45-49, 2018 Jan.
Article in English | MEDLINE | ID: mdl-29594241

ABSTRACT

SYSTEMS-2 is a randomised study of radiotherapy dose escalation for pain control in 112 patients with malignant pleural mesothelioma (MPM). Standard palliative (20 Gy/5#) or dose escalated treatment (36 Gy/6#) will be delivered using advanced radiotherapy techniques and pain responses will be compared at week 5. Data will guide optimal palliative radiotherapy in MPM.

13.
J Exp Biol ; 221(Pt 8)2018 04 13.
Article in English | MEDLINE | ID: mdl-29511069

ABSTRACT

Fishes acclimated to hypoxic environments often increase gill surface area to improve O2 uptake. In some species, surface area is increased via reduction of an interlamellar cell mass (ILCM) that fills water channels between gill lamellae. Amphibious fishes, however, may not increase gill surface area in hypoxic water because these species can, instead, leave water and breathe air. To differentiate between these possibilities, we compared wild amphibious mangrove rivulus Kryptolebias marmoratus from two habitats that varied in O2 availability - a hypoxic freshwater pool versus nearly anoxic crab burrows. Fish captured from crab burrows had less gill surface area (as ILCMs were enlarged by ∼32%), increased rates of normoxic O2 consumption and increased critical O2 tension compared with fish from the freshwater pool. Thus, wild mangrove rivulus do not respond to near-anoxic water by decreasing metabolism or increasing O2 extraction. Instead, fish from the crab burrow habitat spent three times longer out of water, which probably caused the observed changes in gill morphology and respiratory phenotype. We also tested whether critical O2 tension is influenced by genetic heterozygosity, as K. marmoratus is one of only two hermaphroditic vertebrate species that can produce both self-fertilized (inbred) or out-crossed (more heterozygous) offspring. We found no evidence for inbreeding depression, suggesting that self-fertilization does not impair respiratory function. Overall, our results demonstrate that amphibious fishes that inhabit hypoxic aquatic habitats can use a fundamentally different strategy from that used by fully aquatic water-breathing fishes, relying on escape behaviour rather than metabolic depression or increased O2 extraction ability.


Subject(s)
Cyprinodontiformes/anatomy & histology , Cyprinodontiformes/physiology , Gills/anatomy & histology , Gills/physiology , Oxygen/analysis , Animals , Cyprinodontiformes/genetics , Ecosystem , Fresh Water/chemistry , Hermaphroditic Organisms , Inbreeding Depression , Oxygen Consumption
15.
Epidemiol Infect ; 145(14): 3007-3011, 2017 10.
Article in English | MEDLINE | ID: mdl-28879824

ABSTRACT

Giardiasis is a treatable disease, caused by the flagellated protozoan parasite, Giardia duodenalis (G. duodenalis). It is one of the most common enteric parasites found globally to cause gastrointestinal disturbances, and infections may result in long-term irritable bowel syndrome-like symptoms. It is a common misconception that giardiasis is associated with foreign travel, which results in locally acquired cases in the UK being underdiagnosed. This report highlights the findings from one large Scottish Health Board, arising from a change in testing methodology, which resulted in the screening of all stools submitted for enteric investigations for G. duodenalis. Previous selection criteria were restricted to patients with a travel history to specific regions of the world, or on the basis of certain clinical details. In this report, clinical details were recorded from samples shown to be positive using two methods: an ELISA-based antigen detection assay and microscopy. Clinical details were assessed for a total of 28 laboratory-confirmed positive cases against the original selection criteria. Twenty-six cases (93%) would have been excluded from Giardia testing if the previous selection criteria had been applied. Although nine cases stated foreign travel, only two had been to regions deemed to be 'high risk'. Therefore, those seven cases that travelled to perceived 'low-risk' regions would have been excluded from testing for this reason. This summary highlights the need for significant improvements to the selection criteria for Giardia testing. Laboratories should be encouraged towards the testing of all routinely submitted stools for this neglected pathogen to ensure cases that are acquired locally are properly identified and treated effectively.


Subject(s)
Disease Notification/methods , Giardia lamblia/isolation & purification , Giardiasis/diagnosis , Public Health/methods , Adolescent , Adult , Aged , Child , Child, Preschool , Disease Notification/standards , Enzyme-Linked Immunosorbent Assay , Feces/parasitology , Female , Giardiasis/parasitology , Humans , Male , Microscopy , Middle Aged , Scotland , Young Adult
16.
Rev Sci Instrum ; 88(5): 053508, 2017 May.
Article in English | MEDLINE | ID: mdl-28571423

ABSTRACT

In this paper, we describe a new method for measuring surviving neutrons in neutron lifetime measurements using bottled ultracold neutrons (UCN), which provides better characterization of systematic uncertainties and enables higher precision than previous measurement techniques. An active detector that can be lowered into the trap has been used to measure the neutron distribution as a function of height and measure the influence of marginally trapped UCN on the neutron lifetime measurement. In addition, measurements have demonstrated phase-space evolution and its effect on the lifetime measurement.

17.
Epidemiol Infect ; 145(8): 1584-1590, 2017 06.
Article in English | MEDLINE | ID: mdl-28274291

ABSTRACT

Giardia duodenalis and Cryptosporidium species are protozoan parasites capable of causing gastrointestinal disease in humans and animals through the ingestion of infective faeces. Whereas Cryptosporidium species can be acquired locally or through foreign travel, there is the mis-conception that giardiasis is considered to be largely travel-associated, which results in differences in laboratory testing algorithms. In order to determine the level of variation in testing criteria and detection methods between diagnostic laboratories for both pathogens across Scotland, an audit was performed. Twenty Scottish diagnostic microbiology laboratories were invited to participate with questions on sample acceptance criteria, testing methods, testing rates and future plans for pathogen detection. Reponses were received from 19 of the 20 laboratories representing each of the 14 territorial Health Boards. Detection methods varied between laboratories with the majority performing microscopy, one using a lateral flow immunochromatographic antigen assay, another using a manually washed plate-based enzyme immunoassay (EIA) and one laboratory trialling a plate-based EIA automated with an EIA plate washer. Whereas all laboratories except one screened every stool for Cryptosporidium species, an important finding was that significant variation in the testing algorithm for detecting Giardia was noted with only four laboratories testing all diagnostic stools. The most common criteria were 'travel history' (11 laboratories) and/or 'when requested' (14 laboratories). Despite only a small proportion of stools being examined in 15 laboratories for Giardia (2%-18% of the total number of stools submitted), of interest is the finding that a higher positivity rate was observed for Giardia than Cryptosporidium in 10 of these 15 laboratories. These findings highlight that the underreporting of Giardia in Scotland is likely based on current selection and testing algorithms.


Subject(s)
Clinical Audit/standards , Cryptosporidiosis/diagnosis , Giardiasis/diagnosis , Chromatography, Affinity , Cryptosporidiosis/epidemiology , Cryptosporidiosis/parasitology , Cryptosporidium/isolation & purification , Disease Notification , Giardia/isolation & purification , Giardiasis/epidemiology , Giardiasis/parasitology , Humans , Immunoenzyme Techniques , Scotland/epidemiology
18.
Rev Sci Instrum ; 87(4): 045113, 2016 04.
Article in English | MEDLINE | ID: mdl-27131713

ABSTRACT

We have constructed an apparatus to study DC electrical breakdown in liquid helium at temperatures as low as 0.4 K and at pressures between the saturated vapor pressure and ∼600 Torr. The apparatus can house a set of electrodes that are 12 cm in diameter with a gap of 1-2 cm between them, and a potential up to ±50 kV can be applied to each electrode. Initial results demonstrated that it is possible to apply fields exceeding 100 kV/cm in a 1 cm gap between two electropolished stainless steel electrodes 12 cm in diameter for a wide range of pressures at 0.4 K. We also measured the current between two electrodes. Our initial results, I < 1 pA at 45 kV, correspond to a lower bound on the effective volume resistivity of liquid helium of ρV > 5 × 10(18) Ω cm. This lower bound is 5 times larger than the bound previously measured. We report the design, construction, and operational experience of the apparatus, as well as initial results.

19.
Br J Pharmacol ; 172(17): 4342-54, 2015 Sep.
Article in English | MEDLINE | ID: mdl-26040813

ABSTRACT

BACKGROUND AND PURPOSE: Calcium/calmodulin-dependent protein kinase IIδ (CaMKIIδ) is an important regulator of cardiac contractile function and dysfunction and may be an unwanted secondary target for anti-cancer drugs such as sunitinib and imatinib that have been reported to alter cardiac performance. This study aimed to determine whether anti-cancer kinase inhibitors may affect CaMKII activity and expression when administered in vivo. EXPERIMENTAL APPROACH: Cardiovascular haemodynamics in response to acute and chronic sunitinib treatment, and chronic imatinib treatment, were assessed in guinea pigs and the effects compared with those of the known positive and negative inotropes, isoprenaline and verapamil. Parallel studies from the same animals assessed CaMKIIδ expression and CaMKII activity following drug treatments. KEY RESULTS: Acute administration of sunitinib decreased left ventricular (LV) dP/dtmax. Acute administration of isoprenaline increased LVdP/dtmax dose-dependently, while LVdP/dtmax was decreased by verapamil. CaMKII activity was decreased by acute administration of sunitinib and was increased by acute administration of isoprenaline, and decreased by acute administration of verapamil. CaMKIIδ expression following all acute treatments remained unchanged. Chronic imatinib and sunitinib treatments did not alter fractional shortening; however, both CaMKIIδ expression and CaMKII activity were significantly increased. Chronic administration of isoprenaline and verapamil decreased LV fractional shortening with parallel increases in CaMKIIδ expression and CaMKII activity. CONCLUSIONS AND IMPLICATIONS: Chronic sunitinib and imatinib treatment increased CaMKIIδ expression and CaMKII activity. As these compounds are associated with cardiac dysfunction, increased CaMKII expression could be an early indication of cellular cardiotoxicity marking potential progression of cardiac contractile dysfunction.


Subject(s)
Calcium-Calmodulin-Dependent Protein Kinase Type 2/biosynthesis , Heart Diseases/enzymology , Indoles/administration & dosage , Pyrroles/administration & dosage , Animals , Blood Pressure/drug effects , Blood Pressure/physiology , Drug Administration Schedule , Guinea Pigs , Heart Diseases/chemically induced , Heart Rate/drug effects , Heart Rate/physiology , Indoles/adverse effects , Male , Pyrroles/adverse effects , Sunitinib , Treatment Outcome
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