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Biomedical subjects

A Pineau

Publications and source records attributed to A Pineau.

At least 37 records · Page 2Linked to original sources
PubMed1993

An evaluation of the biological significance of aluminium in plasma and hair of patients on long-term hemodialysis.

In hemodialyzed patients, the risk of toxicity attributed to the body accumulation of aluminium (Al) justifies the need for monitoring Al in various human media. In this study, Al concentrations in the hair and plasma of 78 hemodialyzed patients with chronic renal failure and of 351 healthy volunteers were measured by electrothermal atomic absorption spectrometry with Zeeman effect. Plasma Al concentrations in patients were significantly higher than in the controls and positively correlated with time on dialysis. Hair Al levels were widely distributed with no significant distinction between patients and controls. On the subject of establishing correlation, the authors stress the importance of taking into account the kinetics of the elimination of minerals from hair. Even when this was done, in the patient group there was no statistical link between plasma and hair Al levels. Hair Al analysis is of no value as an indicator of body Al accumulation.

Adolescent↗
PubMed1993

Sampling conditions for biological fluids for trace elements monitoring in hospital patients: a critical approach.

Lack of coherence in the results of trace element (TE) analyses produced by various laboratories has been such as to necessitate much needed technical improvements and more detailed control over sample preparations. For too long, except for a few praiseworthy researchers, the importance of sampling conditions has been underestimated as a source of erroneous TE results. Many of the precautionary procedures for previously studied TE collection materials have proven to be so cumbersome that they cannot be applied in a hospital setting. This report deals with sampling material and conditions from a workday standpoint; a rigorous description of the contaminating roles of ambient air and routine handling of specimens places emphasis on the practical. While some metals, including cobalt, copper, iron, and selenium, present no significant risk of contamination, others, such as aluminum, cadmium, chromium, manganese, and nickel, pose quite a significant risk. They warrant attention with respect not only to the sampling itself but also the selection of the material to be used. Drawing on our hospital experience, we propose a critical approach toward the collection of samples of biological fluids (blood, urine, dialysis fluids). Needles, catheters, tubes (open and evacuated systems), and anticoagulants on the market are likewise assessed in terms of their contaminative roles. For each one elementary rules as well as realistic choices of materials and methods for a hospital environment are proposed.

Body Fluids↗
PubMed1992

Congenital hypomagnesemia: alternatives to tissue biopsies for monitoring body magnesium status.

We have been monitoring a 12-year-old boy (his present age) suffering from selective magnesium (Mg) malabsorption. After ascertaining his Mg status, we attempted to maintain Mg balance through the use of oral supplements. Plasma and erythrocyte Mg concentrations were monitored at bimonthly intervals. However these measurements did not accurately reflect Mg status and we subsequently measured Mg in the following tissues: lymphocyte, tooth, and hair. Levels of Mg in stable tissues such as temporary teeth and lymphocytes, unfailingly revealed a marked deficit in Mg that was only two-thirds of the normal levels found in the control group. The use of these readily-accessible stable tissues can thus obviate the need for muscle or bone biopsy. Unfortunately the level in hair is higher than in healthy subjects, and thus does not constitute an adequate measure of Mg status.

Child↗
PubMed1992

Role of aluminium in skin reactions after diphtheria-tetanus-pertussis-poliomyelitis vaccination: an experimental study in rabbits.

The occurrence of subcutaneous nodules at the injection site is one of the complications of diphtheria-tetanus-pertussis-poliomyelitis vaccination, but the causes and mechanisms involved are still poorly understood. An experimental study in the New Zealand rabbit enabled us to determine the frequency of occurrence of these nodules, how long they persist and the histopathologic features of the cells involved. Aluminium (Al) assays by electrothermal atomic absorption spectrometry allowed us to study concentrations both in nodules and the organism (serum, normal skin). The results show an absence of Al diffusion outside nodules, a correlation between infiltrate intensity and Al concentration in nodules and modifications in the histological constituents of nodule cells. The histological picture indicates a foreign body reaction to Al. All these data underscore the role of Al in the formation of early postvaccinal nodules at the injection site.

Aluminum↗
PubMed1992

[Interlaboratory tests: completion of a method of aluminum assay in serum by electrothermal atomic absorption spectrometry].

After carrying out a prior analysis of published literature, the members of the SFBC trace-elements study group present an interlaboratory trial on the measurement of aluminum in serum using electrothermal atomic absorption spectrometry. The means of measurement chosen, following methods reliability criteria, was the use of a standard addition calibration of the samples diluted 1/5 in nitric acid 0.02 mol.l-1. Standard addition calibration was performed on two serums and gives acceptable results. Measurements are preferably carried out in 'tantalised' graphite tubes or pyrolytic tubes with platforms. However, when using graphite tubes, their quality must be checked because measurements can be seriously affected by poor quality tubes.

Aluminum↗
PubMed1990

Intermodal transfer of spatial arrangement of the component parts of an object in infants aged 4-5 months.

Infants' tactual discriminative abilities and intermodal transfer were investigated in two research studies which endeavoured to answer two questions: can infants aged 4-5 months process and discriminate tactually information about different spatial arrangements of elements of an object, in the absence of visual control, and secondly, can they transfer this information from touch to vision? Two experiments were conducted involving a habituation procedure and a procedure which tests reaction to novelty. Infants were found to be able to discriminate tactually between different spatial arrangements of the three elements of an object (experiment 1), and to transfer this information to the visual mode (experiment 2). These findings constitute new data on intermodal functioning in babies.

Attention↗
PubMed1990

[Determination of trace elements in the hair: significance and limitations].

Trace elements analysis in hair is sometimes used by clinician for a diagnosis of nutritional deficiency. Hair contents are supposed to reflect the elements status on an extended period. Hair may be contaminated by environment and its mineral composition may be modified in the different steps of the analytical process. Experiments in well known physiological conditions show a wide variability of the analytical results. These results are poorly correlated to the nutritional status so their interpretation is difficult. An epidemiological use of samples obtained from a wide population may provide worthwhile informations to the clinician. It is necessary to be very careful interpreting results coming from isolated samples.

Adult↗
PubMed1988

[Effects of an anti-inflammatory agent of benzamide structure, dexamethasone and indomethacin on experimental cerebral edema induced by phospholipase 2 in rats].

Only a few molecules show any efficacy against brain edema. Different methods such as brain copper-wire implantation or arachidonic acid injection are used in the research of active drugs. A new model, involving injection of phospholipase A2, is described. The effect of an anti-inflammatory compound, N-(4,6-dimethyl 2-pyridinyl) benzamide, was evaluated on the three different experimental brain edemas mentioned above; dexamethasone and indomethacin were used as reference drugs. The studied molecule is, like dexamethasone, active on the three brain edema models. It has no direct inhibitory effect on phospholipase A2, cannot block cyclooxygenase activity but does reduce prostaglandin biosynthesis. Other factors, such as dopaminergic and alpha 2-adrenergic agonist activities, could also interfere.

Animals↗
PubMed1988

An international quality-assessment program for measurement of aluminum in human plasma: a progress report.

In view of the increasing interest in measurement of aluminum in plasma of hemodialysis patients and the analytical difficulties, which may lead to false clinical interpretations, we organized an international interlaboratory quality-control program that has operated since 1983. The results obtained after four years (72 participants) demonstrate a lessened discrepancy of the results. This program allowed some laboratories to improve their results and even to solve some of their analytical problems. This surveillance will be continued and extended to include the analysis of dialysis fluids.

Aluminum↗
PubMedDate not supplied

A study of chromium in human cataractous lenses and whole blood of diabetics, senile, and normal population.

Chromium (Cr) is of known biological importance, necessary for the maintenance of normal glucose metabolism. There is a lower level of blood Cr concentrations in cases of diabetes. Diabetes carries a risk of cataract development, so the potential effects of Cr on the eye may need to be studied in more depth. The presence of this trace element in both normal and cataractous human lenses has to our knowledge not been investigated so far. The concentration of total Cr in 61 human lenses and 38 blood samples was determined by electrothermal atomic absorption spectrometry with Zeeman effect (EAASZ). Analysis of the levels of Cr in human lenses shows a significant difference between normal and diabetic populations, and an absence of difference between senile and diabetic populations.

Aged↗
PubMedDate not supplied

Total chromium in the human lens. Determination with Zeeman electrothermal atomic absorption spectrometry following mineralization in a mini-autoclave.

A simple, quick procedure has been developed for preparation of human lenses for total chromium (Cr) analysis by electrothermal atomic absorption spectrometry (EAAS). This procedure involves wet ashing in a mini-autoclave with HNO3 and H2SO4. Recovery was 101.6%. This procedure is simple to carry out, does not generate corrosive fumes, and minimizes contaminations. Measurements obtained by this method give values similar to those found previously by more cumbersome methods. It can be conveniently used to prepare biological samples for ultratrace analysis. The mean Cr concentration in human lenses varied between 0.345 +/- 0.147 micrograms/g dry wt in the normal population and 0.205 +/- 0.160 micrograms/g dry wt in cataractous lenses.

Cataract↗
PubMedDate not supplied

Determination of total mercury in human hair samples by cold vapor atomic absorption spectrometry.

A procedure for the determination of mercury in human hair by cold-vapor atomic absorption spectrometry with a new reaction vessel was developed and evaluated. To eliminate the so-called matrix effect, calibration was carried out in an isomedium under identical operating conditions. Under these conditions, the recovery percentage of mercury from human hair digest samples using the peak height method, was 102 +/- 2.2%. The method has been used for measuring the mercury level in hair of different groups of people living in the Nantes, France area.

Calibration↗
PubMedDate not supplied

[Use of the CD-ROM "Tox-Didact" for teaching of toxicology and pharmacology].

Tox-Didact is a multimedia teaching software package for initial training, continuing training and self-learning of toxicology and pharmacology. This software covers a large part of toxicology in its acute and chronic pathology using several approaches: drugs (salicylics, paracetamol, lithium ...); toxins (lead, methanol, carbon monoxide ...); drug addiction and doping (cocaine, heroin, LSD, amphetamines ...); systemic targets (kidneys, skin, liver ...). Tox-Didact is currently composed of 39 modules in validation, each tackling the diagnosis, biological surveillance, treatment, prevention and documentation of a real clinical case. Each module is organized around four types of questions, requiring a choice either (drug, symptom, formula ...) or an open response. Each validated answer is analysed by software which then comments on or corrects it. The essential points which characterize this software are: its multidisciplinarity (toxicology, pharmacology, semiology ...), its reliability (validated by experts), its simplicity of use. It is modular and offers an interactive teaching approach. The objective is to create a portable multimedia tool operational with all computer systems (IBM PC, Macintosh). This program is sustained by the Région des Pays de la Loire and by the Multimedia Resource Office of the French Ministry of National Education.

CD-ROM↗