Clinical Models (clinical + models)

Distribution by Scientific Domains


Selected Abstracts


Disease, deficit or denial?

ACTA PSYCHIATRICA SCANDINAVICA, Issue 1 2005
Models of poor insight in psychosis
Objective:, To examine the evidence for the three kinds of aetiological model that dominate the current literature on poor insight in psychosis: clinical models, the neuropsychological model, and the psychological denial model. Method:, Studies pertaining to one or more of these aetiological models were identified, reviewed and critically evaluated. Results:, There is little support for clinical models, partly because they lack testable hypotheses. Several studies reveal a positive relationship between insight and executive function, which may be related to frontal lobe dysfunction. However, the extent to which this relationship is specific and independent of general cognitive impairment remains unclear. There is tentative evidence to support the psychological denial model. Recent data combining the latter two approaches suggest that multiple factors contribute to poor insight. Conclusion:, Integration of different aetiological models is necessary for a fuller understanding of insight in psychosis. Future research should assess multiple aetiological mechanisms in single investigations. [source]


Clinical perspectives for the study of craving and relapse in animal models

ADDICTION, Issue 8s2 2000
Ting-Kai Li
Several major clinical models of alcoholism in which craving plays a role are summarized and key questions are raised regarding the course of craving in the emergence of alcoholism, how it varies in different stages of the disorder (e.g. active alcoholic, withdrawal, protracted abstinence) and what craving may contribute to major signs and symptoms of alcoholism. Turning to animal models, a plea is made for development of a standardized definition of human craving that can be represented and operationalized in animal models. Until there is scientific consensus on such a definition, four ways are elucidated in which animal model research can contribute to advances in our knowledge of human craving and the role it plays in addictive behavior: (1) engaging both basic and clinical researchers to identify parallel constructs of craving and predictors of craving for adoption in comparative human and animal model studies; (2) conducting exploratory research on craving in animal models using relapse to drinking as the dependent measure; (3) identifying mechanisms that underlie clinical signs and symptoms of alcoholism in animal models; and (4) identifying genetic models in basic research that account for variations in response to alcohol that may also occur in humans. This latter point is made in a discussion of the genetic contribution to voluntary alcohol consumption, the alcohol deprivation effect, tolerance and dependence, as illustrated by differences between alcohol-preferring (P) rats and-nonpreferring (NP) rats. The review concludes with four questions and issues that need to be among those that guide future research on craving. [source]


Assessment of bronchial wall thickness and lumen diameter in human adults using multi-detector computed tomography: comparison with theoretical models

JOURNAL OF ANATOMY, Issue 5 2007
M. Montaudon
Abstract A thickened bronchial wall is the morphological substratum of most diseases of the airway. Theoretical and clinical models of bronchial morphometry have so far focused on bronchial lumen diameter, and bronchial length and angles, mainly assessed from bronchial casts. However, these models do not provide information on bronchial wall thickness. This paper reports in vivo values of cross-sectional wall area, lumen area, wall thickness and lumen diameter in ten healthy subjects as assessed by multi-detector computed tomography. A validated dedicated software package was used to measure these morphometric parameters up to the 14th bronchial generation, with respect to Weibel's model of bronchial morphometry, and up to the 12th according to Boyden's classification. Measured lumen diameters and homothety ratios were compared with theoretical values obtained from previously published studies, and no difference was found when considering dichotomic division of the bronchial tree. Mean wall area, lumen area, wall thickness and lumen diameter were then provided according to bronchial generation order, and mean homothety ratios were computed for wall area, lumen area and wall thickness as well as equations giving the mean value of each parameter for a given bronchial generation with respect to its value in generation 0 (trachea). Multi-detector computed tomography measurements of bronchial morphometric parameters may help to improve our knowledge of bronchial anatomy in vivo, our understanding of the pathophysiology of bronchial diseases and the evaluation of pharmacological effects on the bronchial wall. [source]


Effect of the small molecule plasminogen activator inhibitor-1 (PAI-1) inhibitor, PAI-749, in clinical models of fibrinolysis

JOURNAL OF THROMBOSIS AND HAEMOSTASIS, Issue 6 2010
A. J. LUCKING
Summary.,Background:,The principal inhibitor of fibrinolysis in vivo is plasminogen activator inhibitor-1 (PAI-1). PAI-749 is a small molecule inhibitor of PAI-1 with proven antithrombotic efficacy in several preclinical models. Objective:,To assess the effect of PAI-749, by using an established ex vivo clinical model of thrombosis and a range of complementary in vitro human plasma-based and whole blood-based models of fibrinolysis. Methods:,In a double-blind, randomized, crossover study, ex vivo thrombus formation was assessed using the Badimon chamber in 12 healthy volunteers during extracorporeal administration of tissue-type plasminogen activator (t-PA) in the presence of PAI-749 or control. t-PA-mediated lysis of plasma clots and of whole blood model thrombi were assessed in vitro. The role of vitronectin was examined by assessing lysis of fibrin clots generated from purified plasma proteins. Results:,There was a dose-dependent reduction in ex vivo thrombus formation by t-PA (P < 0.0001). PAI-749 had no effect on in vitro or ex vivo thrombus formation or fibrinolysis in the presence or absence of t-PA. Inhibition of PAI-1 with a blocking antibody enhanced fibrinolysis in vitro (P < 0.05). Conclusions: Despite its efficacy in a purified human system and in preclinical models of thrombosis, the current study suggests that PAI-749 does not affect thrombus formation or fibrinolysis in a range of established human plasma and whole blood-based systems. [source]


A bilateral clinical model for the study of acute and chronic pain after breast-reduction surgery

ACTA ANAESTHESIOLOGICA SCANDINAVICA, Issue 5 2001
R. F. Bell
Background: There is a need for new clinical models to investigate effectively the development of pain after surgery and the effect, if any, of pre-emptive treatment. Bilateral models are of special interest, since the patient serves as his/her own control. The objective of this preliminary study was to test a clinical model for the study of acute and chronic pain after bilateral reduction mammoplasty. Methods: Eight patients participated in the study where the breasts were randomized to test and control groups. In each patient, one breast was preoperatively infiltrated with lidocaine and adrenaline and the other breast infiltrated with saline and adrenaline. Assessment included visual analogue scale (VAS) pain intensity, thermal thresholds, mapping for punctate hyperalgesia and tactile sensation. Assessments were made preoperatively, postoperatively and at 6 months after surgery. Results: With regard to acute postoperative pain intensity, the model demonstrated a clear difference between lidocaine and placebo treated breasts. There was no difference between lidocaine and placebo treated breasts with regard to chronic pain, but these results are inconclusive due to small number of patients. Conclusion: The model is sensitive and may be useful in studies of mechanisms of development and prevention of chronic pain after surgery. [source]


Degradation of HER2 Receptor Through Hypericin-mediated Photodynamic Therapy

PHOTOCHEMISTRY & PHOTOBIOLOGY, Issue 1 2010
Ján Kova
Current treatment of breast cancer is often affected by resistance to therapeutics, for which the human epidermal growth factor receptor 2 (HER2) may be responsible. Here, we report for the first time the use of hypericin-mediated photodynamic therapy (HY-PDT) in combination with a selective HER2 inhibitor (AG 825) on SKBR-3, a HER2 overexpressing human breast adenocarcinoma cell line. The results demonstrate that HY-PDT is able to degrade HER2 with an impact on its signaling cascade. Combination with AG 825 resulted in increased apoptosis induction, total degradation of HER2 and inhibition of colony formation. Downregulation of HSP90, Mcl-1, Bcl-xL and upregulation of Bax was also observed. This knowledge provides the basis for the possible application of HY-PDT in preclinical and clinical models of breast cancer treatment. [source]


Predictive models of toxicity with external radiotherapy for prostate cancer,

CANCER, Issue S13 2009
Clinical issues
Abstract The objective of the current study was to analyze the state of the art and present limitations of available predictive clinical models (when available) estimating the risk of genitourinary tract and small bowel complications, erectile dysfunction, and acute and late symptoms of the rectal syndrome caused by prostate cancer external irradiation. An analysis of the literature indicated that very limited attention has been devoted to the development of "integrated," patient-tailored, user-friendly, and clinically usable tools for the prediction of external beam radiotoxicity. In this article, the authors reported on the multivariate correlation between late genitourinary and gastrointestinal toxicities and clinical/dosimetric risk factors, as well as on the first set of nomograms developed to predict acute and late rectal side effects. At the present state of knowledge, the use of nomograms as predictive instruments of radiotoxicity appears to be particularly attractive for several main reasons. They are "user friendly" and easily developed using the results of multivariate analyses, as they weigh the combined effects of multiple independent factors found to be correlated with the selected clinical endpoint. The integrated evaluation of clinical and dosimetric parameters in the single patient can help to provide a tailored probability of the specific outcome considered. Predicting a high probability of toxicity could avoid unnecessary daily costs for the individual patient in terms of quality of life modification during and after treatment, helping patients in the decision-making process of choosing the best individual, quality of life,related treatment, and clinicians in better tailoring the treatment to patient's characteristics. Cancer 2009;115(13 suppl):3141,9. © 2009 American Cancer Society. [source]


HIV Transmission Risk Behaviors of Men and Women Living With HIV-AIDS: Prevalence, Predictors, and Emerging Clinical Interventions

CLINICAL PSYCHOLOGY: SCIENCE AND PRACTICE, Issue 1 2000
Seth C. Kalichman
This article reviews research on continued risk practices among individuals who know they are HIV infected. Across populations, one in three persons with HIV-AIDS continue practicing HIV transmission risk behaviors. Continued high-risk behaviors in persons with HIV are related to relationship factors, economic conditions, emotional states, substance abuse, and personality dispositions. High-risk behaviors are more likely with another infected person, but alarming rates of risk behaviors are observed with HIV-negative partners and partners of unknown HIV status. Risk practices are also affected by disclosure of HIV status and by perceptions of how anti-HIV medications may affect infectivity. New clinical models of intervention are needed to blend HIV prevention strategies with HIV-AIDS care services. [source]