Health related utility measurement in rheumatology: an introduction

Utility measures of health-related quality of life are preference values that patients attach to their overall health status. In clinical trials, utility measures summarize both positive and negative effects of an intervention into one single value between 0 (equal to death) and 1 (equal to perfect health). These measures allow for comparison of patient outcomes of different diseases and allow for comparison between various health care interventions. There are two different approaches to utility measurement. The first is to classify patients into categories based on their responses to a number of questions about their functional status, as for instance the Quality of Well-Being questionnaire. The second approach is to ask patients to assign a single rating to their overall health by means of rating scale, standard gamble, time trade-off, or willingness to pay. The Quality Adjusted Life Year (QALY) as outcome measure includes both effects in terms of quality and quantity of life. Utilities are used as weights to adjust life years for the quality of life in order to calculate QALYs. Both QALYs and utilities are useful in decision-making regarding appropriate procedures for groups of patients.     

Spectro-temporal studies of Xe---Cl excimer laser-induced arterial wall fluorescence

We report on spectro-temporal fluorescence studies of cadaver femoral arterial walls at different stages in the progression of atherosclerosis. After excitation with a Xe---Cl excimer pulse, the time course of the fluorescence spectrum was recorded over time, and time-resolved multispectral analysis was performed. Then, under the assumption of linearity, we derived a linear spectro-temporal kernel (a weighting function) which describes the temporal behavior of the fluorescence process independently of the pulse width of the photoexcitation. The data analysis revealed both static and dynamic fluorescence characteristics which exhibited a good correlation with histological findings.     

Some approaches to the pharmacology of multisubstrate enzyme systems

Analytical and exploratory in vitro, in situ and in vivo, physio-pharmacotoxicology, from enzymology to population epidemiology, now embraces those approaches that correlate complex dynamic multisubstrate kinetics through conventional and more recent non-invasive quantitative methodologies.Basically, substrates may be classed as pertaining to fundamental energy turnovers (first-order cellular metabolic pathways or networks) and to iso- vs allosteric modulator systems (second-order metabolic control network). Pairs of substrates and cofactors set-up the third-order multienzyme-receptor patterns, which in intact, native in vivo structures establish and maintain the compartmentalized, dynamically superimposed overall coordination of local redox and phosphate potentials.Perturbations of the various levels of the metabolic hierarchy induced by drugs, as well their relaxations, can be readily submitted to non-invasive kinetic analysis. Both indirect and direct titrations of substrate levels, their modelling and statistical ad hoc evaluations of their interrelations can lead to the identification of the multiple sites involved in drug effects as structured at the different orders/levels of concomitant functional variations. Fractal geometries contribute towards defining the space- and time-related events.     

Effets tardifs des radiations sur le foie

Until recently, the liver was classified as a radioresistant organ, although it is in fact highly radiosensitive. The realization that the whole liver could be treated safely only with low doses of radiation led to the conclusion that radiation therapy had an extremely limited role in the treatment of intrahepatic malignancies. A resurgence of interest has been observed with the advent of conformal radiotherapy and the introduction of bone marrow transplantation with total body irradiation. The radiation-induced liver disease, often called radiation hepatitis, is a syndrome characterized by the development of anicteric ascites, approximately 2 weeks to 4 months after hepatic irradiation. Immediate tolerance is generally surprisingly good, and the subacute radiation injury is followed by a complete asymptomatic healing, although the late lesions may be associated with signs of chronic radiation hepatitis. Radiation hepatitis must be distinguished from chemoradiation-induced-hepatitis occuring in patients undergoing bone marrow transplantation and total body irradiation. Both syndromes demonstrate the same pathological lesion: veno-occlusive disease. The main treatment for radiation hepatitis is diuretics, although soma advocate steroids for severe cases.     

Myxoid change within cellular blue naevi: a diagnostic pitfall

We describe four cases of a distinctive myxoid change located in the centre of cellular blue naevi. Because all the reported lesions were large and were present on pressure-exposed locations, the myxoid change is thought to be caused by pressure together with direct repeated minor tissue trauma.     

Les prothèses mammaires et leurs complications

Reported complications of breast implants.In the past few years silicone breast implants have been a highly charged and controversial topic for psychologic, health and politico-legal reasons for patients and for surgical, medical and research concern for professionals. Both sides are interested in knowing about the complications encountered with these implants on one hand and to find the ideal device needed for mammary reconstruction on the other. Indeed silicone does not fulfill the characteristics initially expected for a synthetic soft-tissue substitute. The local cellular response leads to the formation of a capsule around the implant with frequently unsatisfying cosmetic results. The well described leakage occurring through the silicone envelope allows the silicone gel to diffuse to multiple anatomic areas in the body. Scientific works demonstrated that silicone gel acts as a potent immunologie adjuvant and can induce antibodies to silicone surface-associated antigens. Breast implanted women who present with systemic clinical symptoms can be included either in the group of well defined connective tissue diseases or in the atypical connective tissue diseaselike syndrome. The largest epidemiologic studies have shown reassuring evidence against large hazards but have documented a low but statistically significant risk of connective-tissue diseases in women with silicone gel filled implants. Practicioners must manage these patients with the awareness that reliable objective tests to identify the useful problem are not yet available.     

L''évaluation du coût des complications peut-elle contribuer à la poursuite du développement de la radiothérapie ?

At the present time, the current improvement of technical and dosimetric aspects of radiation oncology has to be evaluated in terms of potential benefit for the patient and the society. For this last point of view, specially designed economic analyses must be performed in order to justify the number of resources involved by these technical improvements. If the question is how the current technical procedures could reduce the risk of undesirable side-effects, the response cannot be immediately drawn from the literature. This paper emphasizes the possibility to evaluate the role of side-effects as endpoints of economic analyses when using special models in medical decision making such as Markov's. Only few oncologic situations are reliable to properly analyze the relationship between sophisticated radiation techniques and the incidence of post-radiation complications. These situations should be selected when prospective economic analyses are planned in the field of radiation therapy.     

Parathyroid hyperplasia in tertiary hyperparathyroidism: a pathological and immunohistochemical reappraisal

Thirty-one parathyroid glands from 11 patients with tertiary hyperparathyroidism were examined histologically and immunohistochemically to characterize better the nature of the accompanying parathyroid hyperplasia. The parathyroids showed varying degrees of nodular and diffuse hyperplastic involvement as well as apparently normal background tissue. The nodules were usually multiple within any one gland and, together with diffuse hyperplastic tissue, showed a varied cyto-architectural pattern. All glands studied showed both cellular argyrophilia and parathyroid hormone immunoreactivity. The staining pattern for parathyroid hormone ranged from negative or weak to strong, and from patchy to diffuse in hyperplastic tissue from different glands and within the same gland, regardless of the cell type. Apparently normal areas usually showed only patchy weak to moderately strong parathyroid hormone positivity. From the data obtained the most striking feature of the parathyroid glands in tertiary hyperparathyroidism is their extreme variability, both morphological and functional, as indicated by parathyroid hormone immunoreactivity. Furthermore, the generally lesser degree of parathyroid hormone immunoreaction observed in apparently normal parathyroid tissue may reflect suppression of hormone synthesis, with accompanying morphological regression to normal of pre-existent diffuse hyperplasia by autonomous hyperfunctioning nodules associated with tertiary hyperparathyroidism.