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Biomedical subjects

P Blaise

Publications and source records attributed to P Blaise.

17 recordsLinked to original sources
PubMed2005

[Circadian variations in intraocular pressure and their clinical implications].

Intraocular pressure follows a circadian rhythm like many of the body's parameters. These fluctuations in intraocular pressure were recently identified as a risk factor for visual field loss, in addition to intraocular pressure itself. Furthermore, the pressure curve seems to have a different profile in glaucomatous patients: the peak occurs later compared with normal subjects. Better knowledge of pressure fluctuations and their physiological mechanisms is essential for optimal management of glaucomatous patients not only to interpret the single ocular tension recordings, but also to use the available treatments rationally, both drugs and surgery. The authors review different studies that have contributed to the current knowledge on the circadian rhythm of intraocular pressure, aquous humor flow regulation, and the effects of topical hypotensive drugs on the pressure curve.

Adult↗
PubMed2004

[Retinal vascular occlusions: diagnosis and management].

PURPOSE: The diagnosis of retinal venous and arterial occlusions is usually easily evoked on visual symptoms and ophthalmoscopic features. However, their management (etiologic explorations and treatment) has not been formally established and remains controversial. CURRENT KNOWLEDGE AND KEY POINTS: Some retinal vascular occlusions may result of loco-regional ocular causes. They more often occur in patients with cardiovascular pathologies or risk factors, or sometimes other systemic diseases that need to be recognized for a proper treatment. Therefore, a comprehensive management of patients with retinal vascular occlusions is necessary to correct associated diseases or predisposing abnormalities that could lead to local recurrences or systemic events. CONCLUSION: Along with a review of the literature, we suggest a practical approach for the management of retinal vascular occlusions, which requires a collaboration between the ophthalmologist and other physicians: general practitioner, cardiologist, internist... as appropriate according to each case.

Humans↗
PubMed2003

[Anterior lenticonus: diagnostic aid in Alport syndrome].

Anterior lenticonus is a rare condition in which the lens presents a conical protrusion of its anterior cortex. Sometimes isolated, it may be an ocular manifestation of Alport syndrome, a hereditary nephritis accompanied by deafness and other ocular signs such as flecked retinopathy or posterior polymorphous corneal dystrophy. All these manifestations are a result of a genetic defect in type IV collagen, a major component of basal membranes in the human body. The clinical aspects and therapy of anterior lenticonus and Alport syndrome are described, as well as the exploration that must begin when anterior lenticonus is discovered. This exploration is essential so that this diagnosis can be made as soon as possible.

Humans↗
PubMed2002

[Update on hepatorenal syndrome].

The hepatorenal syndrome is a form of renal failure occurring in patients with advanced liver disease. The diagnosis is based both on the demonstration of low GFR and exclusion of other common causes of renal failure that may occur in patients with cirrhosis. Orthotopic liver transplantation remains the only curative treatment for this poor outcome disease; other modalities such as vasopressin analogues, transjugular intrahepatic portosystemic shunt or renal replacement therapies may serve as a bridge to transplantation. This article reviews the pathophysiology, diagnosis and current treatment of hepatorenal syndrome.

Acute Kidney Injury↗
PubMed2001

Charge-induced fragmentation of sodium clusters.

The fission of highly charged sodium clusters with fissilities X>1 is studied by ab initio molecular dynamics. Na4+24 is found to undergo predominantly sequential Na+3 emission on a time scale of 1 ps, while Na(Q+)(24) ( 5< or =Q< or =8) undergoes multifragmentation on a time scale > or =0.1 ps, with Na+ increasingly the dominant fragment as Q increases. All singly charged fragments Na(+)(n) up to size n = 6 are observed. The observed fragment spectrum is, within statistical error, independent of the temperature T of the parent cluster for T< or =1500 K. These findings are consistent with and explain recent trends observed experimentally.

Journal Article↗
PubMed2000

[Idiopathic pulmonary fibrosis: a new histopathologic classification and clinical aspects].

Idiopathic pulmonary fibrosis (IPF) comprises different interstitial lung diseases of unknown origin. They are classified into four groups based on pathologic criteria: UIP, DIP, AIP and NSIP. This classification helps in terms of prognosis and treatment. In addition to history, physical examination and common investigations (chest X ray, pulmonary function testing), a bronchoalveolar lavage (BAL), a high-resolution CT scan and ideally a open-lung biopsy are needed to establish a precise diagnosis. The patients are usually treated by immunosuppressive agents, and mainly by corticoids. However, in UIP, lung transplantation is the only way to improve survival.

Anti-Inflammatory Agents↗
PubMed1997

Chemoenzymatic synthesis of glucose fatty esters.

D-Glucose fatty esters at C-6 were obtained by chemoenzymatic synthesis involving 1,2-O-cyclohexylidene-alpha-D-glucofuranose (1) followed by hydrolysis of the cyclohexylidene protecting group. The enzymatic esterification of 1 was performed with fatty acids of variable chain lengths (C8:0 to C18:0). The kinetic of the reaction was studied for each fatty acid and the structure of the octanoyl ester was determined by 1H and 13C NMR spectroscopy.

Esters↗
PubMed1991

Geobase: a simple geographical information system on a personal computer.

Spatially distributed data are often encountered in the biological sciences. Representation and analysis of such data requires specific tools. A simple geographical information system is presented, which allows representation and elementary analysis of geographically coded information. The system handles two kinds of data: maps and facts, where map data describe the basis on which the fact data are located. Maps consist of objects described through a set of coordinates, while for facts a coordinate pair is associated with an unlimited number of data records containing five fields: a date, an element from a list, a two-character code, an integer number and a real number. The input data can be displayed interactively on screen by logically combining selection criteria for each field. The facts corresponding to the selected criteria are either displayed as such, or are clustered and displayed as polygons or pies. A short example showing a possible application of the program is presented and advantages as well as limitations are discussed.

Algorithms↗
PubMed1985

Quantitative determination of tertatolol in biological fluids by gas chromatography-mass spectrometry.

Quantitative determination of tertatolol concentrations in plasma and urine was performed by gas chromatography-mass spectrometry in the chemical-ionization mode with ammonia after successive extractions of the beta-blocking drug in alkaline, acid and final alkaline medium. [2H9]Tertatolol, isotopically stable under the operating conditions employed, was used as an internal standard, thus allowing quantities of 1 ng/ml to be specifically determined. Overall analytical error was less than 10%. Prior to isothermal chromatography at 240 degrees C on a column packed with 3% SE-30, both compounds were silylated with bis(trimethylsilyl)trifluoroacetamide. Detection was performed by monitoring the quasimolecular ions of tertatolol, m/z 368 and m/z 377, for the [2H9]tertatolol in the chemical-ionization mode with ammonia. The calibration curves obtained had linear characteristics for the concentration range 1-1125 ng/ml.

Administration, Oral↗
PubMedDate not supplied

A realistic approach to the evaluation of the quality management movement in health care systems: a comparison between European and African contexts based on Mintzberg's organizational models.

The quality movement is gaining momentum worldwide in the field of health care. Initiated in industrialized countries, it steadily grows in Africa. However, there is no evidence that approaches designed to address issues in a given organizational context have the same effect in another one where issues present differently. Along the epistemological paradigm of realistic evaluation proposed by Pawson and Tilley, we use Mintzberg's organizational models to compare the configurations of European and African health care organizations and the trends followed by the quality management movement in both contexts. We illustrate how European health systems traditionally emphasize professional autonomy while African health systems are structured as command and control hierarchical systems. We illustrate how the quality movement in Europe emphasizes standardization of procedures, a characteristic of a mechanistic organization, while excessive standardization is part of the quality problem in Africa. We suggest that instilling professionalism may be a way forward for the quality movement in Africa to improve patient focus and responsiveness of responsible professionals. We also suggest that our interpretation of broad trends and contrasts may be used as a useful departure point to study the wide contextual diversity of the African experience with quality management.

Africa↗
PubMedDate not supplied

HIV resistance to antiretroviral drugs: mechanisms, genotypic and phenotypic resistance testing in clinical practice.

HIV resistance to antiretroviral agents is a major contributory cause of treatment failure. The dynamics of HIV replication, together with patient-, physician-, and drug-related factors, lead to emergence of HIV resistant strains in most of the patients. Phenotypic assays look for an increase in the antiretroviral drug (ARV) concentration that inhibits 50% of the growth of the tested HIV strain (IC50), comparatively with a reference strain cultivated in parallel. Genotypic tests detect resistance mutations in the reverse transcriptase and protease genes by comparing the gene sequences of a resistant virus to those of a wild-type strain that has previously been described. The efficacy of each ARV class and each individual ARV is threatened by specific mutations and resistance mechanisms. In retrospective studies of genotypic or phenotypic resistance testing, baseline resistance tests results were correlated with virological outcomes. There is some evidence from prospective studies that resistance testing may have some benefits when used to choose salvage regimens. However, problems in the areas of test interpretation, patient compliance, availability of active drugs, and technical test performance limit the usefulness of resistance testing in clinical practice. This article reviews the mechanisms underlying HIV resistance, the principles of phenotypic and genotypic tests, and the use of these tests in clinical practice.

Anti-HIV Agents↗
PubMedDate not supplied

[Centralized purchasing of essential drugs, a priority for the health care systems of developing countries].

Health sector reform is a key priority of many governments throughout the world. Drug supply systems are a major element of public health policy design in Africa, where 90% of drugs are imported. The WHO Essential Drugs Program and the UNICEF sponsored Bamako Initiative have, since the late 1980s, promoted the rational use of essential drugs and attempted to ensure a sustainable drug supply through the implementation of cost recovery schemes and quality assurance mechanisms in public health services. A new market for drugs is emerging within this framework and there is growing competition for its control. Government medical stores are all too often bankrupt and the private sector is expensive, catering mainly for the middle to upper classes of urban areas. An intermediate alternative. Essential Drugs Purchasing Offices (EDPOs), has been proposed to balance social objectives and economic constraints. Some of the experimental strategies have given promising results. However, their implementation raises a number of questions: What is the role of the EDPO? Should it promote public health issues in general or focus purely on drug availability? What is the most appropriate legal status? Public or private? For profit or not? How should the investment capital be structured? In drugs or in funds? With ample provision or a tight budget? How should drug purchases be managed? Where should drugs be purchased? How much? How often? According to which procedures? How should the distribution of drugs be organized? Supplying everyone? Pushing supplies or pulling purchasers in? The answers to these questions, analysis of the reasons for success and failure and the dissemination of the information gathered should identify priorities for action and future research and define a framework for expansion. These are the objectives of the "Concerted Action for the Development of EDPO in Sub-Saharan African Countries" which is supported by the European Union (DG XII).

Africa↗