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Mitochondria, present in almost all eukaryotic cells, produce energy and contribute to many other essential cellular functions. In particular, mitochondria possess their own genome, which is transmitted in a uniparental maternal mode that involves very specific mechanisms during gametogenesis and embryogenesis. This easily quantifiable mitochondrial DNA (mtDNA) is an excellent biomarker of the mitochondrial mass. The mature oocyte has been shown to be the richest cell in mtDNA and the mitochondrial mass of the oocyte has been correlated with its ability to support embryonic development in many species. The initial mitochondrial contingent of the oocyte is indeed the basis on which subtle metabolic changes are needed at each of the key stages of early embryonic development. For example, epigenetic reprogramming is under the strong influence of metabolic cofactors derived from mitochondrial metabolism, and the reactive oxygen species produced by the respiratory chain are essential elements for the regulation of cell signalling in the embryo. This mitochondrial involvement in the reproductive processes has made mtDNA a biomarker of oocyte competence and embryonic viability. Although current data require confirmation, it allows mitochondria to be considered as potential therapeutic targets. This review focuses on the past 20 years of research that have led to the emergence of these novel concepts. [ABSTRACT FROM AUTHOR]

Introduction: arterial hypertension is a major public health problem in sub-Saharan Africa due to its high frequency and to the cardiovascular risk that it entails. The purpose of this study was to assess the prevalence of clinical and biological risk factors of hypertension in Bamako (Mali). Methods: we conducted a case-control study, stratified in function of the sex, of 72 participants including 36 patients with hypertension and 36 controls. Twenty-two plasma biochemical parameters have been measured and analyzed using univariate and multivariate tests. Results: hyperhomocysteinemia was found in 55.6% of women (p = 0.03) and 100% of men (p = 0.007) with hypertension. High NT-proBNP was also found in 16.7% of women (VIP > 1 in multivariate model) and of men with hypertension (p = 0.00006). A good multivariate predictive model (OPLS-DA) was only obtained in women with high blood pressure, with Q²cum = 0.73, attesting severe sexual dimorphism associated with arterial hypertension. This model involved eight parameters whose plasma concentration was modified (homocysteine, NT-proBNP, potassium, urea, blood glucose, sodium, chlorine and total proteins). Conclusion: we registered a significant association between hyperhomocysteinemia and arterial hypertension. Therefore, the assay of homocysteine associated with good management would decrease the risk of cardiovascular diseases while improving the quality of life of hypertensive patients. [ABSTRACT FROM AUTHOR]

Introduction: Arterial hypertension is a major public health problem in sub-Saharan Africa due to its high frequency and to the cardiovascular risk that it entails. The purpose of this study was to assess the prevalence of clinical and biological risk factors of hypertension in Bamako (Mali)., Methods: We conducted a case-control study, stratified in function of the sex, of 72 participants including 36 patients with hypertension and 36 controls. Twenty-two plasma biochemical parameters have been measured and analyzed using univariate and multivariate tests., Results: Hyperhomocysteinemia was found in 55.6% of women (p = 0.03) and 100% of men (p = 0.007) with hypertension. High NT-proBNP was also found in 16.7% of women (VIP > 1 in multivariate model) and of men with hypertension (p = 0.00006). A good multivariate predictive model (OPLS-DA) was only obtained in women with high blood pressure, with Q 2 cum = 0.73, attesting severe sexual dimorphism associated with arterial hypertension. This model involved eight parameters whose plasma concentration was modified (homocysteine, NT-proBNP, potassium, urea, blood glucose, sodium, chlorine and total proteins)., Conclusion: We registered a significant association between hyperhomocysteinemia and arterial hypertension. Therefore, the assay of homocysteine associated with good management would decrease the risk of cardiovascular diseases while improving the quality of life of hypertensive patients., Competing Interests: Les auteurs ne déclarent aucun conflit d'intérêts., (© Yaya Goïta et al.)

Hypothermia is a potentially lethal pathology whose in vivo diagnosis is relatively easy, based on the observation of a body temperature below 35̊C. However, its post mortem diagnosis is much more complex because of a thermal decrease occurring systematically after the death, which renders most often uninterpretable the body temperature as a diagnostic argument for hypothermia. Moreover, none of the macroscopic or microscopic autopsy elements described as suspicious of hypothermia are pathognomonic of a hypothermic death. Currently, this diagnosis arises in the light of an association of concordant arguments including these autopsic and histological elements but also some biomarkers. The aim of this article is to illustrate by a practical case the diagnostic complexity of a death by hypothermia through the evocative elements currently described, by emphasizing the reflection on some biomarkers confirmed or under study.

Thanatobiochemistry refers to a post mortem study of biochemical parameters enabling to shed light on a cause of death. This discipline shines when suspected lethal pathology doesn't have any noticeable macroscopic or microscopic features such as diabetic ketoacidosis. We relate the case of fourty-five years old patient followed-up for type I diabetes mellitus, discovered dead at home, for which only post mortem biochemical exploration of vitreous humor allowed to determine the cause of death by diabetic ketoacidosis.

Metabolomics is defined as an integrative approach consisting in the comprehensive analysis of all of the small molecules of a biological system (the "metabolome"). The main objective of metabolomics in medecine is to discover metabolic biomarkers for diseases. Mass spectrometry (MS) coupled to liquid or gas chromatography is amongst major analytical tools used in metabolomics. However, the holistic approach used in metabolomics requires very good performances of the analytical system (chromatographic column and MS equipment) and the use of non-conventional validation strategies. Metabolomics workflow can be divided in three main steps: sample preparation, MS data acquisition and processing, and statistical analysis. Processing of the "raw" data (obtained after MS acquisition) is mostly required to normalise chromatographic conditions and to carry out accurate quantification of MS features. Features resulting from this processing may be identified later. The statistical analyses include typically multivariate techniques such as supervised and non-supervised methods. Supervised methods make use of the response variable (e.g., case/control) for model construction while non-supervised methods do not use this piece of information. When the study is focused on a particular set of metabolites, targeted metabolomics could be an interesting alternative to the holistic approach since it may allow absolute quantitation and be associated with a reduced cost.

Steroid hormone measurement, first developed with radioimmunoassay, is now becoming easier with the use of automated platforms of immunoassay. However, some hormones remain uneasily detectable because of their low blood concentration, their structural homology or the presence of interferences. Liquid chromatography-tandem mass spectrometry (LC-MS/MS) can be considered as an alternative to immunoassays. This approach allows the simultaneous determination of several parameters thanks to its selectivity led by the detector mass spectrometer and the separate dimension of chromatography liquid. In addition, recourse to UHPLC (ultra high performance liquid chromatography) allows improving selectivity and sensitivity while limiting the samples volumes. The "ready-to-use" kits are now available and added to the "homemade" techniques developed by laboratories, thus giving opportunity for measurement of a wide steroid panel with only one sample. Finally, mass spectrometry methods, including a prior extraction step, allow the use of varied biological fluids (blood, urine, saliva…). Also, several clinical indications could gain from mass spectrometry, especially when hormone levels are low, when several steroids have to be identified, when the sample volume is low. However, this technology represents an important financial investment and in-depth staff training. In addition, some steroids are not easily quantifiable by mass spectrometry. It is likely by immunoassay and mass spectrometry, well-matched technologies, that we could answer the best to clinical questions about steroids.

We describe the case of a 30-year-old patient, suffering from composite S/β + sickle cell disease. He was hospitalized following a vaso-occlusive attack with acute bone pains. Despite an analgesic treatment and transfusion of three units of red blood cells, a non-regenerative anemia appeared within 24 hours. One day later an acute chest syndrome with atelectasis of the left lung and desaturation and multi-organ failure occurred and necessitated the patient's intubation and required him to be placed in an artificial coma. A bronchoalveolar lavage was performed, which eliminated pneumonia but proved, after staining with oil red O, many neutral fatty acid microvacuoles in more than 80% of macrophages, suggesting a pulmonary fat embolism. The hypothesis of a bone marrow necrosis causing a pulmonary fat embolism was discussed and confirmed the next day by the characteristic appearance of the bone marrow. A therapeutic protocol associating iteratively bleeding and red blood cells transfusion was administered on the second day with the objective of maintaining haemoglobin S at less than 20% rate. Successive haemoglobin S assay was applied using a high performance liquid chromatography (HPLC) technique with a quick response within one hour after transfusion or bleeding. This protocol resulted in an improvement in the patient's condition, with a gradual normalization of vital signs and extubation twelve days later and discharge without sequelae twenty-five days later. The succession of rare but serious sickle cell complications anaemia which occurred in this patient could be controlled by adapting the laboratory for the clinical emergency.

Several epidemiological studies suggest that pesticides could lead to neurodegenerative diseases such as Parkinson's and Alzheimer's diseases. Among pesticides, insecticides appear more neurotoxic than others but the neurotoxic mechanisms leading to adverse health effects remain unclear. The currently used pesticides such as rotenone and paraquat could disrupt mitochondrial bioenergetic function, reactive oxygen metabolism, redox function and promote α-synuclein aggregation. In addition, recent studies demonstrate that genetic susceptibility to Parkinson's disease could monitor pesticide susceptibility, as demonstrated for polymorphisms in pesticide metabolizing enzymes that are involved in organophosphorus sensitivity., (© 2013 médecine/sciences – Inserm / SRMS.)

Ten years ago, OPA1 was identified as the major gene responsible for hereditary optic nerve degeneration, evidencing the first defect in mitochondrial network dynamics as the princeps pathophysiological mechanism in a mitochondriopathy. Later, alterations in other genes involved in mitochondrial fusion or fission, such as MFN2, DRP1 and GDAP1, were also associated with inherited neurological diseases, mainly affecting peripheral nerves. More recently, altered mitochondrial plasticity was also demonstrated in common age-related neurodegenerative disorders, as Alzheimer and Parkinson diseases, thus substantiating the critical role of mitochondrial dynamics in neurons as a key element governing the efficiency of oxidative respiration and its distribution along the axons.

Mitochondria play a primary role in cellular energetic metabolism. They possess their own DNA, which is exclusively maternally transmitted. The relatively recent idea that mitochondria may be directly involved in human reproduction is arousing increasing interest in the scientific and medical community. It has been shown that the functional status of mitochondria contributes to the quality of oocytes and spermatozoa, and plays a part in the process of fertilisation and embryo development. Moreover, new techniques, such as ooplasm transfer, compromise the uniquely maternal inheritance of mitochondrial DNA, raising important ethical questions. This review discusses recent information about mitochondria in the field of human fertility and reproduction.