1,409 research outputs found
Providing adhesion for a miniture mobile intra-abdominal device based on biomimetic principles
This paper investigates the surface adhesion
characteristics required for a miniature mobile device to
move around the abdominal cavity. Such a device must
be capable of adhering to the tissue lining and move
freely across the upper surface of the insufflated
abdomen. Accordingly, the potential of utilising bioinspired
solutions to facilitate wet adhesion is assessed
5-Aminolevulinic acid-mediated fluorescence diagnosis of colon cancer: A histopathological comparison of fluorescent and non-fluorescent tumours
Background: 5-Aminolevulinic acid (5-ALA) selectively accumulates in cancer cells and is metabolised in the mitochondria to the fluorophore protoporphyrin IX. The GLiSten trial evaluated 5-ALA as a fluorescent probe for intraoperative detection of colon cancer and lymph node metastases. Only 13 of 40 cases showed fluorescence, suggesting a fundamental difference between fluorescent and non-fluorescent cancers. The aim of this study was to investigate whether differences in fluorescence were due to tumour cellularity, in particular T cell infiltration, which may be of prognostic significance. Method: Primary tumour tissue was available from 30 patients. The density of tumour cells, vascularity and stromal compartment size were quantified using digitally scanned tissue sections stained with haematoxylin and eosin. A set of 300 random points was superimposed onto each tumour image. The structure indicated by each point was then categorised as tumour, stroma, vessel or other. The proportions of tumour and vessel points gave the tumour cell density and vessel density respectively. The relative size of the stromal compartment was given by the tumour to stroma ratio. A tissue section was also stained for the T cell marker CD3 by immunohistochemistry. Percentage staining was quantified in three high-density fields using the Nuance imaging system. Results: We were unable to detect any difference between fluorescent and non-fluorescent cancers in terms of tumour cell density (difference in means 3.7%; P = 0.452), vessel density (difference in means 0.17%; P = 0.684), tumour-stroma ratio (difference in mean ratios 0.12; P = 0.934), or T cell count (difference in means 0.92%; P = 0.726). Furthermore, comparisons of the distributions of each variable demonstrated substantial overlap between the fluorescent and non-fluorescent cohorts. Conclusion: The results suggest that tumour and microenvironment structure do not differ between cancers that fluoresce with 5-ALA and those that do not. We therefore propose that the cellular metabolism of 5-ALA is a more likely explanation for differential fluorescence
Activated mesothelial cells produce heparin-binding growth factors: implications for tumour metastases
Curative surgery for gastrointestinal malignancy is commonly thwarted by local tumour recurrence. The heparin-binding growth factors, basic fibroblast growth factor (bFGF), heparin-binding epidermal growth factor-like growth factor (HB-EGF) and vascular epidermal growth factor (VEGF) are all implicated in the metastatic process, but whether or not these essential growth factors are produced by the activated peritoneum is unknown. This study reveals that peritoneal mesothelial cells constitutively express mRNA for bFGF, HB-EGF and two VEGF spliced variants, VEGF121and VEGF165. Mesothelial activation with interleukin (IL)-1b or tumour necrosis factor (TNF)-a produced an up-regulation of mRNA for HB-EGF and VEGF, but not bFGF expression. IL-6 failed to stimulate growth factor expression, whereas IL-2 produced a marked suppression in HB-EGF and bFGF, but not VEGF expression. Mesothelial cells were shown to predominantly express mRNA for the intermediate affinity (bgc) IL-2 receptor. Cytokine-induced growth factor up-regulation was confirmed at the protein level using Western blotting of mesothelial cell lysates for HB-EGF and culture supernatant enzyme-linked immunosorbent assay for VEGF. The production of these growth factors by human mesothelial cells may play a significant role in post-operative peritoneal tumour recurrence. Their common heparin-binding property offers a potential therapeutic target for manipulating the growth factor environment of the human peritoneum. © 2000 Cancer Research Campaig
East Midlands Research into Ageing Network (EMRAN) Discussion Paper Series
Academic geriatric medicine in Leicester
.
There has never been a better time to consider joining us. We have recently appointed a
Professor in Geriatric Medicine, alongside Tom Robinson in stroke and Victoria Haunton,
who has just joined as a Senior Lecturer in Geriatric Medicine. We have fantastic
opportunities to support students in their academic pursuits through a well-established
intercalated BSc programme, and routes on through such as ACF posts, and a successful
track-record in delivering higher degrees leading to ACL post. We collaborate strongly
with Health Sciences, including academic primary care. See below for more detail on our
existing academic set-up.
Leicester Academy for the Study of Ageing
We are also collaborating on a grander scale, through a joint academic venture focusing
on ageing, the ‘Leicester Academy for the Study of Ageing’ (LASA), which involves the
local health service providers (acute and community), De Montfort University; University
of Leicester; Leicester City Council; Leicestershire County Council and Leicester Age UK.
Professors Jayne Brown and Simon Conroy jointly Chair LASA and have recently been
joined by two further Chairs, Professors Kay de Vries and Bertha Ochieng. Karen
Harrison Dening has also recently been appointed an Honorary Chair.
LASA aims to improve outcomes for older people and those that care for them that takes
a person-centred, whole system perspective. Our research will take a global perspective,
but will seek to maximise benefits for the people of Leicester, Leicestershire and Rutland,
including building capacity. We are undertaking applied, translational, interdisciplinary
research, focused on older people, which will deliver research outcomes that address
domains from: physical/medical; functional ability, cognitive/psychological; social or
environmental factors. LASA also seeks to support commissioners and providers alike for
advice on how to improve care for older people, whether by research, education or
service delivery. Examples of recent research projects include: ‘Local History Café’
project specifically undertaking an evaluation on loneliness and social isolation; ‘Better
Visits’ project focused on improving visiting for family members of people with dementia
resident in care homes; and a study on health issues for older LGBT people in Leicester.
Clinical Geriatric Medicine in Leicester
We have developed a service which recognises the complexity of managing frail older
people at the interface (acute care, emergency care and links with community services).
There are presently 17 consultant geriatricians supported by existing multidisciplinary
teams, including the largest complement of Advance Nurse Practitioners in the country.
Together we deliver Comprehensive Geriatric Assessment to frail older people with
urgent care needs in acute and community settings.
The acute and emergency frailty units – Leicester Royal Infirmary
This development aims at delivering Comprehensive Geriatric Assessment to frail older
people in the acute setting. Patients are screened for frailty in the Emergency
Department and then undergo a multidisciplinary assessment including a consultant
geriatrician, before being triaged to the most appropriate setting. This might include
admission to in-patient care in the acute or community setting, intermediate care
(residential or home based), or occasionally other specialist care (e.g. cardiorespiratory).
Our new emergency department is the county’s first frail friendly build and includes
fantastic facilities aimed at promoting early recovering and reducing the risk of hospital
associated harms.
There is also a daily liaison service jointly run with the psychogeriatricians (FOPAL); we
have been examining geriatric outreach to oncology and surgery as part of an NIHR
funded study.
We are home to the Acute Frailty Network, and those interested in service developments
at the national scale would be welcome to get involved.
Orthogeriatrics
There are now dedicated hip fracture wards and joint care with anaesthetists,
orthopaedic surgeons and geriatricians. There are also consultants in metabolic bone
disease that run clinics.
Community work
Community work will consist of reviewing patients in clinic who have been triaged to
return to the community setting following an acute assessment described above.
Additionally, primary care colleagues refer to outpatients for sub-acute reviews. You will
work closely with local GPs with support from consultants to deliver post-acute, subacute,
intermediate and rehabilitation care services.
Stroke Medicine
24/7 thrombolysis and TIA services. The latter is considered one of the best in the UK
and along with the high standard of vascular surgery locally means one of the best
performances regarding carotid intervention
Preliminary investigation of the influence of dopamine regulating genes on social working memory
Working memory (WM) refers to mental processes that enable temporary retention and manipulation of information, including information about other people (“social working memory”). Previous studies have demonstrated that nonsocial WM is supported by dopamine neurotransmission. Here, we investigated in 131 healthy adults whether dopamine is similarly involved in social WM by testing whether social and nonsocial WM are influenced by genetic variants in three genes coding for molecules regulating the availability of dopamine in the brain: catechol-O-methyltransferase (COMT), dopamine active transporter (DAT), and monoamine-oxidase A (MAOA). An advantage for the Met allele of COMT was observed in the two standard WM tasks and in the social WM task. However, the influence of COMT on social WM performance was not accounted for by its influence on either standard WM paradigms. There was no main effect of DAT1 or MAOA, but a significant COMT x DAT1 interaction on social WM performance. This study provides novel preliminary evidence of effects of genetic variants of the dopamine neurotransmitter system on social cognition. The results further suggest that the effects observed on standard WM do not explain the genetic effects on effortful social cognition
IntAct:intra-operative fluorescence angiography to prevent anastomotic leak in rectal cancer surgery: a randomized controlled trial
Aim
Anastomotic leak (AL) is a major complication of rectal cancer surgery. Despite advances in surgical practice, the rates of AL have remained static, at around 10–15%. The aetiology of AL is multifactorial, but one of the most crucial risk factors, which is mostly under the control of the surgeon, is blood supply to the anastomosis. The MRC/NIHR IntAct study will determine whether assessment of anastomotic perfusion using a fluorescent dye (indocyanine green) and near‐infrared laparoscopy can minimize the rate of AL leak compared with conventional white‐light laparoscopy. Two mechanistic sub‐studies will explore the role of the rectal microbiome in AL and the predictive value of CT angiography/perfusion studies.
Method
IntAct is a prospective, unblinded, parallel‐group, multicentre, European, randomized controlled trial comparing surgery with intra‐operative fluorescence angiography (IFA) against standard care (surgery with no IFA). The primary end‐point is rate of clinical AL at 90 days following surgery. Secondary end‐points include all AL (clinical and radiological), change in planned anastomosis, complications and re‐interventions, use of stoma, cost‐effectiveness of the intervention and quality of life. Patients should have a diagnosis of adenocarcinoma of the rectum suitable for potentially curative surgery by anterior resection. Over 3 years, 880 patients from 25 European centres will be recruited and followed up for 90 days.
Discussion
IntAct will rigorously evaluate the use of IFA in rectal cancer surgery and explore the role of the microbiome in AL and the predictive value of preoperative CT angiography/perfusion scanning
Kinetics of submicron oleic acid aerosols with ozone: A novel aerosol mass spectrometric technique
The reaction kinetics of submicron oleic (9-octadecanoic (Z)-) acid aerosols with ozone was studied using a novel aerosol mass spectrometric technique. In the apparatus a flow of size-selected aerosols is introduced into a flow reactor where the particles are exposed to a known density of ozone for a controlled period of time. The aerosol flow is then directed into an aerosol mass spectrometer for particle size and composition analyses. Data from these studies were used to: (a) quantitatively model the size-dependent kinetics process, (b) determine the aerosol size change due to uptake of ozone, (c) assess reaction stoichiometry, and (d) obtain qualitative information about the volatility of the reaction products. The reactive uptake probability for ozone on oleic acid particles obtained from modeling is 1.6 (±0.2) × 10^(−3) with an upper limit for the reacto-diffusive length of ∼10 nm. Atmospheric implications of the results are discussed
Interventions for renal vasculitis in adults. A systematic review
<p>Abstract</p> <p>Background</p> <p>Renal vasculitis presents as rapidly progressive glomerulonephritis and comprises of a group of conditions characterised by acute kidney failure, haematuria and proteinuria. Treatment of these conditions involves the use of steroid and non-steroid agents with or without adjunctive plasma exchange. Although immunosuppression has been successful, many questions remain unanswered in terms of dose and duration of therapy, the use of plasma exchange and the role of new therapies. This systematic review was conducted to determine the benefits and harms of any intervention for the treatment of renal vasculitis in adults.</p> <p>Methods</p> <p>We searched the Cochrane Central Register of Controlled Trials, the Cochrane Renal Group Specialised Register, MEDLINE and EMBASE to June 2009. Randomised controlled trials investigating any intervention for the treatment of adults were included. Two authors independently assessed study quality and extracted data. Statistical analyses were performed using a random effects model and results expressed as risk ratio with 95% confidence intervals for dichotomous outcomes or mean difference for continuous outcomes.</p> <p>Results</p> <p>Twenty two studies (1674 patients) were included. Plasma exchange as adjunctive therapy significantly reduces the risk of end-stage kidney disease at 12 months (five studies: RR 0.47, CI 0.30 to 0.75). Four studies compared the use of pulse and continuous administration of cyclophosphamide. Remission rates were equivalent but pulse treatment causes an increased risk of relapse (4 studies: RR 1.79, CI 1.11 to 2.87) compared with continuous cyclophosphamide. Azathioprine has equivalent efficacy as a maintenance agent to cyclophosphamide with fewer episodes of leukopenia. Mycophenolate mofetil may be equivalent to cyclophosphamide as an induction agent but resulted in a higher relapse rate when tested against Azathioprine in remission maintenance. Rituximab is an effective remission induction agent. Methotrexate or Leflunomide are potential choices in remission maintenance therapy. Oral co-trimoxazole did not reduce relapses significantly in Wegener's granulomatosis.</p> <p>Conclusions</p> <p>Plasma exchange is effective in patients with severe ARF secondary to vasculitis. Pulse cyclophosphamide results in an increased risk of relapse when compared to continuous oral use but a reduced total dose. Whilst cyclophosphamide is standard induction treatment, rituximab and mycophenolate mofetil are also effective. Azathioprine, methotrexate and leflunomide are effective as maintenance therapy. Further studies are required to more clearly delineate the appropriate place of newer agents within an evidence-based therapeutic strategy.</p
Collision Dynamics and Solvation of Water Molecules in a Liquid Methanol Film
Environmental molecular beam experiments are used to examine water
interactions with liquid methanol films at temperatures from 170 K to 190 K. We
find that water molecules with 0.32 eV incident kinetic energy are efficiently
trapped by the liquid methanol. The scattering process is characterized by an
efficient loss of energy to surface modes with a minor component of the
incident beam that is inelastically scattered. Thermal desorption of water
molecules has a well characterized Arrhenius form with an activation energy of
0.47{\pm}0.11 eV and pre-exponential factor of 4.6 {\times} 10^(15{\pm}3)
s^(-1). We also observe a temperature dependent incorporation of incident water
into the methanol layer. The implication for fundamental studies and
environmental applications is that even an alcohol as simple as methanol can
exhibit complex and temperature dependent surfactant behavior.Comment: 8 pages, 5 figure
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