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Since the publication of the ordinance of January 13th 2010, ratified by the law of May 30th 2013, medical biology in France has undergone a massive restructuration with the emergence of groups of several hundred laboratories. This evolution, which leads to a considerable reduction in the number of structures, causes numerous problems related to increased industrialization and financialization, difficulties of accreditation and disappearance of the proximity link between the biologist and the prescriber or the patient. It also leads to a clear disaffection of students, especially medical students, for this specialty whose medical character has been clearly affirmed by the law. This report takes stock of the current situation of medical biology and makes recommendations to strengthen the role of the medical biologist in the health system and patients' care.

Proteic (neuritic plaques, amyloid substances...) and genetic characteristics of Alzheimer's disease are reviewed. An infectious origin appears unlikely. After production of specific antibodies, the reported abnormal Tau proteins might represent peripheral markers of the disease. Changes in olfactory neurons, accessible for biopsy specimens, might give rise to new biological diagnosis of Alzheimer's disease.

Estro-progestative drugs (EPD) have been used for many years and multiple secondary effects have been reported concerning mainly the glucidic and lipidic metabolisms. Effects of EPD on steroid metabolism have also been described and the authors present a review of the literature on this subject. Particularly it appears that EPD affect: the glucocorticoid metabolism, with augmentation of total cortisol although not in its free-form (augmentation of transcortine), the adrenal androgens metabolism, with diminution of their circulating rates, the aldosterone metabolism with augmentation of its secretion. These biological constatations could help explaining some clinical features occurring with administration of EPD: diminution of hirsutism and/or acne, augmentation of body weight, appearance of hypertension.

The blood platelets, which serious arguments permit one to consider as valid models of serotoninergic neurones, were studied in various types of depression and during treatment with antidepressor drugs. The modifications of several platelet parameters were analysed in particular. The level of hydroxyndoles (OH-5-tryptamine or 5-HT for example) is generally lowered. The uptake of 5-HT is also reduced with normalisation by antidepressor treatments; the fixation of mepacrine, sign of the passive uptake of bioamines, is modified in the same direction, especially, in our experience, in maniacs, with a rise during treatment with phenothiazines. Finally, among the platelet enzymes, monoamine oxidase has a reduced activity in bipolar depressed patients, certain maniac depressive psychosis, and endogenic melancholias. Other platelet parameters, (liberation or release, nucleotide levels, 5-HT bonds at membrane level, etc.) may provide in the future, interesting information. In spite of sometimes contradictory data, the platelet model may be of interest, especially from pharmacological point of view.

Free and total tryptophan is estimated in the plasma by a spectrofluorimetric method using an amplification reaction and fluorescence by transformation of tryptophan into norharman using formalin and perhydrol (fluorescence is amplified about 15 times). Free tryptophan in the plasma is separated by ultrafiltration under pressure. We verified the analytical characteristics of the method in order to obtain optimal conditions. Values frequently found in 16 blood donors in good health were 10.4 +/- 3.3 micronmol/l. for free tryptophan (average +/- ts for a risk of 5%) and 54.6 +/- 18.6 micronmol/l. for total tryptophan.

Marked variations in the same individual of serum iron levels may be due to a circadian rhythm. We determined the reference values of serum iron in a population of blood donors who had no blood disease. The very wide reference interval found (0.47 to 1.75 mg/l in man and 0.36 to 1.66 mg/l in women) was due to physiological variations rather than analytical variations. We also demonstrated in individuals with a normal life rhythm, a circadian rhythm for iron with maximal levels in the morning (8 to 12) and minimal levels in the evening (8 p.m. to midnight) the ratio of these levels is usually between 1.5 and 2, but may reach much higher figures. On the other hand, the total fixation capacity varies little over 24 hours. In night workers, one may note a displacement of the cycle with a maximum towards 8 p.m. a minimum at 8 a.m. In diabetics, the circadian rhythm exists but with a lower amplitued than in healthy subjects. In a few cases a hemochromatosis, one may note disappearance of the cycle.

The present report describes spectrofluorimetric methods for evaluation of furosemide (a sulfamide diuretic derived from anthranilic acid) in plasma or urine. The availability of these methods is discussed. These methods can be used for pharmacokinetic and pharmacological studies and sometimes resolution of therapeutic problems.

The values of hydroxyprolinuria were determined in 314 cases of Paget's disease and 91 cases of osteoma. During Paget's disease, the values found were related to the degree of the bony disorder. A more detailed study of the hydroxyproline polypeptides was undertaken, comparatively in a few cases of these two diseases. In Paget's disease, there was shown a relative increase in the oligopeptide fraction, whereas the polypeptide fraction was increased in osteoma. By chromatographic and electrophoretic technics, it was shown that the acid oligopeptides (containing mainly the dipeptide (Glu-Hyp) are in percentage, reduced in Paget's disease and increased in osteoma, whereas the neutral oligopeptides (containing mainly Pro-Hyp) undergo the opposite variation in these two diseases.

Urinary hydroxyproline is mainly in the form of oligopeptide and polypeptide, with a low proportion of free amino acid. Overall or partial estimation of hydroxyprolinuria may be carried out after isolation and hydrolysis of the peptides on ion exchange resin, by an automatic, continuous flow technique. This method presents a certain number of advantages, such as, selectivity, sensitivity and practicability, compared with that which we proposed in 1968. Determination of the criteria of quality of the method shows that it is suitable for exploration of variations in hydroxyprolinuria in diseases of bone and collagen. The reference values in relation to age and sex are also reported.

The authors determined in 3 populations (37 controls, 59 asymptomatic hyperlipemias, and 20 cases of arterial hyperlipemia) the total cholesterol, the HDL cholesterol and the LDL + VLDL cholesterol and their ratio by two methods : precipitation by concanavalin A and ultracentrifugation (AirFuge). These various lipid parameters were compared between 3 populations in order to determine their more or less discriminant character; furthermore, was established the degree of correlation between the results obtained by precipitation with concanavalin A and by ultracentrifugation. The results show : firstly, that the LDL + VLDL was significantly higher and the ratio HDL/LDL + VLDL significantly lower in hyperlipemia and in arterial disease compared with controls ; the HDL was significantly lower in arterial disease than in controls. No lipid parameter permitted one to differentiate between asymptomatic hyperlipemia and arterial disease. Furthermore, the correlation determined by the chi square method was very strong between the results obtained by precipitation with concanavalin A and ultracentrifugation as the coefficient of simple linear regression is very little different from the value + 1. They emphasize the interest of the method of precipitation by concanavalin A which is simple, rapid and very reliable.

We propose a micromethod of diazepam determination on 0,1 ml of whole blood. The extraction is made with n-heptane for the isolation of diazepam in presence of principal metabolites. For the usual concentrations, the precision is about 3 per cent; at the detection limite, 0,05 mug/ml, it is about 20 per cent. With this method we studied the pharmacokinetics of diazepam in neonate with convulsive diseases in comparison with electroencephalogram.