433 research outputs found
The time-dependent localization of Ki 67 antigen-positive cells in human skin wounds
A total of 77 human skin wounds with a post-infliction interval between 3 h and 7 months were investigated and the proliferation marker antigen Ki 67 was visualized in paraffin sections using a specific monoclonal antibody (MIB). The re-built epidermal layer covering the former lesional area showed only a few basal cells positively staining for Ki 67 antigen. No enhanced reactivity was found when compared to uninjured skin. In basal cells of the epidermis adjacent to the wound area, however, varying numbers of positive cells occurred, but no information useful for a reliable time estimation of skin wounds could be obtained due to the considerable variability in the number of Ki 67 positive epidermal basal cells found in non-damaged skin. Fibroblastic cells in the wound area revealed an increased number of Ki 67-positive sites which could first be detected in a 1.5-day-old skin lesion. Positive results could be obtained in every specimen investigated after a post-infliction interval of 6 days up to 1.5 months. Only the scar tissue of the oldest wound examined (wound age 7 months) revealed no increase in the number of positively staining fibroblasts. Therefore, positive results indicate a wound age of at least approximately 1.5 days and the lack of an increased number of positive fibroblastic cells in a sufficient number of specimens indicates at a wound age of less than 6 days, but cannot totally exclude longer post-infliction intervals
Resource use data by patient report or hospital records: Do they agree?
Background: Economic evaluations alongside clinical trials are becoming increasingly common.
Cost data are often collected through the use of postal questionnaires; however, the accuracy of
this method is uncertain. We compared postal questionnaires with hospital records for collecting
data on physiotherapy service use.
Methods: As part of a randomised trial of orthopaedic medicine compared with orthopaedic
surgery we collected physiotherapy use data on a group of patients from retrospective postal
questionnaires and from hospital records.
Results: 315 patients were referred for physiotherapy. Hospital data on attendances was available
for 30% (n = 96), compared with 48% (n = 150) of patients completing questionnaire data (95% Cl
for difference = 10% to 24%); 19% (n = 59) had data available from both sources. The two methods
produced an intraclass correlation coefficient of 0.54 (95% Cl 0.31 to 0.70). However, the two
methods produced significantly different estimates of resource use with patient self report recalling
a mean of 1.3 extra visits (95% Cl 0.4 to 2.2) compared with hospital records.
Conclusions: Using questionnaires in this study produced data on a greater number of patients
compared with examination of hospital records. However, the two data sources did differ in the
quantity of physiotherapy used and this should be taken into account in any analysi
Eulerian simulation of the fluid dynamics of helicopter brownout
A computational model is presented that can be used to simulate the development of the dust cloud
that can be entrained into the air when a helicopter is operated close to the ground in desert or dusty
conditions. The physics of this problem, and the associated pathological condition known as âbrownoutâ
where the pilot loses situational awareness as a result of his vision being occluded by dust suspended in the
flow around the helicopter, is acknowledged to be very complex. The approach advocated here involves
an approximation to the full dynamics of the coupled particulate-air system. Away from the ground, the
model assumes that the suspended particles remain in near equilibrium under the action of aerodynamic
forces. Close to the ground, this model is replaced by an algebraic sublayer model for the saltation and
entrainment process. The origin of the model in the statistical mechanics of a distribution of particles
governed by aerodynamic forces allows the validity of the method to be evaluated in context by comparing
the physical properties of the suspended particulates to the local properties of the flow field surrounding
the helicopter. The model applies in the Eulerian frame of reference of most conventional Computational
Fluid Dynamics codes and has been coupled with Brownâs Vorticity Transport Model. Verification of the
predictions of the coupled model against experimental data for particulate entrainment and transport in
the flow around a model rotor are encouraging. An application of the coupled model to analyzing the
differences in the geometry and extent of the dust clouds that are produced by single main rotor and
tandem-rotor configurations as they decelerate to land has shown that the location of the ground vortex
and the size of any regions of recirculatory flow, should they exist, play a primary role in governing the
extent of the dust cloud that is created by the helicopter
Formation of superdense hadronic matter in high energy heavy-ion collisions
We present the detail of a newly developed relativistic transport model (ART
1.0) for high energy heavy-ion collisions. Using this model, we first study the
general collision dynamics between heavy ions at the AGS energies. We then show
that in central collisions there exists a large volume of sufficiently
long-lived superdense hadronic matter whose local baryon and energy densities
exceed the critical densities for the hadronic matter to quark-gluon plasma
transition. The size and lifetime of this matter are found to depend strongly
on the equation of state. We also investigate the degree and time scale of
thermalization as well as the radial flow during the expansion of the
superdense hadronic matter. The flow velocity profile and the temperature of
the hadronic matter at freeze-out are extracted. The transverse momentum and
rapidity distributions of protons, pions and kaons calculated with and without
the mean field are compared with each other and also with the preliminary data
from the E866/E802 collaboration to search for experimental observables that
are sensitive to the equation of state. It is found that these inclusive,
single particle observables depend weakly on the equation of state. The
difference between results obtained with and without the nuclear mean field is
only about 20\%. The baryon transverse collective flow in the reaction plane is
also analyzed. It is shown that both the flow parameter and the strength of the
``bounce-off'' effect are very sensitive to the equation of state. In
particular, a soft equation of state with a compressibility of 200 MeV results
in an increase of the flow parameter by a factor of 2.5 compared to the cascade
case without the mean field. This large effect makes it possible to distinguish
the predictions from different theoretical models and to detect the signaturesComment: 55 pages, latex, + 39 figures available upon reques
Peripheral neural cell sensitivity to mTHPC-mediated photodynamic therapy in a 3D in vitro model
Background: The effect of photodynamic therapy (PDT) on neural cells is important when tumours are within or adjacent to the nervous system. The purpose of this study was to investigate PDT using the photosensitiser, meta tetrahydroxyphenyl chlorin (mTHPC), on rat neurons and satellite glia, compared with human adenocarcinoma cell (MCF-7).Methods: Fluorescence microscopy confirmed that mTHPC was incorporated into all three cell types. Sensitivity of cells exposed to mTHPC-PDT (0â10 ”g mlâ1) was determined in a novel 3-dimensional collagen gel culture system. Cell death was quantified using propidium iodide and cell types were distinguished using immunocytochemistry. In some cases, neuron survival was confirmed by measuring subsequent neurite growth in monolayer culture.Results: MCF-7s and satellite glia were significantly more sensitive to PDT than neurons. Importantly, 4 ”g mlâ1 mTHPC PDT caused no significant neuron death compared with untreated controls but was sufficient to elicit substantial cell death in the other cell types. Initially, treatment reduced neurite length; neurons then extended neurites equivalent to those of untreated controls. The protocol was validated using hypericin (0â3 ”g mlâ1), which caused neuron death equivalent to other cell types.Conclusion: Neurons in culture can survive mTHPC-PDT under conditions sufficient to kill tumour cells and other nervous system cells
EULAR recommendations for women's health and the management of family planning, assisted reproduction, pregnancy and menopause in patients with systemic lupus erythematosus and/or antiphospholipid syndrome.
OBJECTIVES: Develop recommendations for women's health issues and family planning in systemic lupus erythematosus (SLE) and/or antiphospholipid syndrome (APS). METHODS: Systematic review of evidence followed by modified Delphi method to compile questions, elicit expert opinions and reach consensus. RESULTS: Family planning should be discussed as early as possible after diagnosis. Most women can have successful pregnancies and measures can be taken to reduce the risks of adverse maternal or fetal outcomes. Risk stratification includes disease activity, autoantibody profile, previous vascular and pregnancy morbidity, hypertension and the use of drugs (emphasis on benefits from hydroxychloroquine and antiplatelets/anticoagulants). Hormonal contraception and menopause replacement therapy can be used in patients with stable/inactive disease and low risk of thrombosis. Fertility preservation with gonadotropin-releasing hormone analogues should be considered prior to the use of alkylating agents. Assisted reproduction techniques can be safely used in patients with stable/inactive disease; patients with positive antiphospholipid antibodies/APS should receive anticoagulation and/or low-dose aspirin. Assessment of disease activity, renal function and serological markers is important for diagnosing disease flares and monitoring for obstetrical adverse outcomes. Fetal monitoring includes Doppler ultrasonography and fetal biometry, particularly in the third trimester, to screen for placental insufficiency and small for gestational age fetuses. Screening for gynaecological malignancies is similar to the general population, with increased vigilance for cervical premalignant lesions if exposed to immunosuppressive drugs. Human papillomavirus immunisation can be used in women with stable/inactive disease. CONCLUSIONS: Recommendations for women's health issues in SLE and/or APS were developed using an evidence-based approach followed by expert consensus
Effects of a 105 hours psychological training program on attitudes, communication skills and occupational stress in oncology: a randomised study
There is today a wide consensus regarding the need to improve communication skills (CS) of health-care professionals (HCPs) dealing with cancer patients. Psychological training programs (PTPs) may be useful to acquire the needed CS. Testing the efficacy of PTP will allow to define their optimal content. The present study was designed to assess the impact of a PTP on HCP stress, attitudes and CS, and on HCP and patients' satisfaction with HCP communication skills in a randomised study. A total of 115 oncology nurses were randomly assigned to a 105-h PTP or to a waiting list. Stress was assessed with the Nursing Stress Scale, attitudes with a Semantic Differential Questionnaire, CS used during one simulated and one actual patient interview with the Cancer Research Campaign Workshop Evaluation Manual, and satisfaction with the nurses' CS with a questionnaire completed by the patients and the nurses. Trained (TG) and control (CG) groups were compared at baseline, after 3 months (just following training for TG) and after 6 months (3 months after the end of training for TG). Compared to controls, trained nurses reported positive changes on their stress levels (P</=0.05) and on their attitudes (P</=0.05). Positive training effects were found on CS used during the simulated interview: a significant increase in facilitative behaviours (open questions: P</=0.001; evaluative functions: P</=0.05) and a significant decrease in inhibitory behaviours (inappropriate information: P</=0.01; false reassurance: P</=0.05). Less positive training effects were found regarding interviews with a cancer patient: a significant increase in educated guesses (P</=0.001) was noticed. No training effect was observed on nurses' satisfaction levels, but a positive training effect was found on patients' satisfaction levels (P</=0.01). Although results outline PTP efficacy, they indicate the need to design PTP, amplifying the transfer of learned CS to clinical practice.info:eu-repo/semantics/publishe
Fluctuations in active membranes
Active contributions to fluctuations are a direct consequence of metabolic
energy consumption in living cells. Such metabolic processes continuously
create active forces, which deform the membrane to control motility,
proliferation as well as homeostasis. Membrane fluctuations contain therefore
valuable information on the nature of active forces, but classical analysis of
membrane fluctuations has been primarily centered on purely thermal driving.
This chapter provides an overview of relevant experimental and theoretical
approaches to measure, analyze and model active membrane fluctuations. In the
focus of the discussion remains the intrinsic problem that the sole fluctuation
analysis may not be sufficient to separate active from thermal contributions,
since the presence of activity may modify membrane mechanical properties
themselves. By combining independent measurements of spontaneous fluctuations
and mechanical response, it is possible to directly quantify time and
energy-scales of the active contributions, allowing for a refinement of current
theoretical descriptions of active membranes.Comment: 38 pages, 9 figures, book chapte
Target 2035 - an update on private sector contributions
Target 2035, an international federation of biomedical scientists from the public and private sectors, is leveraging âopenâ principles to develop a pharmacological tool for every human protein. These tools are important reagents for scientists studying human health and disease and will facilitate the development of new medicines. It is therefore not surprising that pharmaceutical companies are joining Target 2035, contributing both knowledge and reagents to study novel proteins. Here, we present a brief progress update on Target 2035 and highlight some of industry's contributions
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