[Reforming Biosciences and Health Research: Part I, Funding]. / Rapport 21-06. Réformer la recherche en sciences biologiques et en santé : partie I, le financement.

The COVID-19 pandemic occurred in the context of a dramatic decline in support for biological and health research in France. An analysis of resources allocated to this sector shows that the credits in 2020 correspond to only 17.2 % of the total credits allocated to research, the lowest ratio inat least 15 years. Another weakness in the system of support for hospital research is the way funds from the health insurance system are allocated. To bring it into line with international best practices, the task of allocating these funds should be entrusted to a "Hospital Research Orientation Council", which should also be involved in the implementation of national research programming. Another article deals with the organization of research. Recommendations are also made to improve the functioning of the research system at the local level, particularly in university hospitals, and at the national level.

[Transgenic mice: a major advance in biomedical research]. / Les souris transgéniques: un progrès dans la recherche biomédicale.

Transgenic mice bear stable, artificially induced genetic modifications that are transmitted to their offspring. They are prepared from cultured embryonic stem cells isolated from blastocysts. The stem cells are then transfected with a vector comprising a selection cassette and the sequence to be introduced, modified or suppressed, lying between two sequences identical to those flanking the target gene. The target gene is thereby "knocked out" and replaced by the selection cassette, through homogeneous recombination. Cells in which recombination has successfully taken place are sorted by detecting the selection cassette, and are injected into an embryo. This results in so-called mosaic mice which, after crossing, will give birth to mice that are either heterozygous or homozygous for the knocked out gene. A variety of genomic modifications can be obtained with this approach, including gene knock-out, insertion of multiple gene copies, introduction of a reporter gene under the control of the promoter of the gene of interest, and "conditional" mutations that are expressed in a given tissue or for a specific period of time. Transgenic mice can be used to examine the phenotype resulting from a null mutation or from the introduction of multiple gene copies, as well as factors controlling the synthesis of a specific protein, the phenotypic consequences of point mutations, and the genes involved in embryo development. Institutes have been created specifically to phenotype transgenic mice, frequently using non invasive techniques. The results thus obtained are collected in databases, thus allowing scientists to determine the minimal number of animals necessary for a given experiment.

[The biology of aging]. / Biologie du vieillissement.

Although aging is unavoidable, its course can be influenced by various factors, as illustrated by the increase in life expectancy associated with improvements in hygiene and with the general reduction in morbidity. Longevity has also been altered experimentally in some animal species. Aging follows a period of growth and reproduction. Death may occur when the immortality of the germinal line has been ensured. In other cases it results from gradual cellular deterioration. Four principal molecular and cellular processes have been studied in experimental models (mainly mice, worms and fruit flies):--inhibition of the insulin/IGF-1 axis increases life expectancy by allowing a transcription factor (DAF-16 in C. elegans, FoXo in mice) to enter the nucleus, where it stimulates the expression of genes encoding survival-promoting proteins; one such inhibitor is Klotho protein;--the detrimental effects of highly toxic reactive oxygen species, mainly produced in the mitochondria, are partly controlled by scavenging molecules and enzymes. Their accumulation leads to DNA, lipid and protein changes, resulting in cell dysfunction;--the telomeres situated at the ends of each chromosome get shorter with time because of inadequate telomerase activity, and this appears to be associated with diminished longevity;--autophagia within lysosomes destroys altered proteins and thereby maintains cell homeostasis. However, this activity diminishes with time, resulting in the accumulation of toxic metabolites in the cell, dysfunction of the endoplasmic reticulum and mitochondria, and increased apoptosis. Studies of genetically mediated aging disorders have revealed the importance of lamins (intermediate nuclear filaments). For example, a mutation that prevents the protein lamin A from maturing is the cause of progeria, a disease associated with an acceleration of most aging processes and with premature death. There is no single biological marker of aging. In contrast, a combination of Nt-proBNP, troponin I, C-reactive protein and cystatin may be useful, as increased levels are a risk factor for atheroma and cardiovascular diseases, both of which are associated with aging. The different organs age in different ways: vessel walls become rigid due to protein glycation and develop atheroma; the heart is invaded by fibrosis; the brain suffers from neurofibrillar degeneration and senile plaques (responsible for Alzheimer's disease); the retina undergoes macular degeneration; renal function declines in parallel with the fall in the glomerular filtration rate due to a gradual decrease in the nephron pool; and immune defenses become less effective due to the functional degradation of B and T lymphocytes and thymus involution. Reproduction is a special case: despite the increase in human longevity, the chronology of the reproductive cycle and the age of menopause onset have not changed. The frequency of cancers increases with age, due to the increase in somatic mutations and the decline in immune defenses. Drug therapy must be adapted to age, owing to age-related changes in pharmacology. Physical exercise and dietary measures are currently the only known ways of slowing the aging process.

Change in salt intake affects blood pressure of chimpanzees: implications for human populations.

BACKGROUND: Addition of up to 15.0 g/d salt to the diet of chimpanzees caused large rises in blood pressure, which reversed when the added salt was removed. Effects of more modest alterations to sodium intakes in chimpanzees, akin to current efforts to lower sodium intakes in the human population, are unknown. METHODS AND RESULTS: Sodium intakes were altered among 17 chimpanzees in Franceville, Gabon, and 110 chimpanzees in Bastrop, Tex. In Gabon, chimpanzees had a biscuit diet of constant nutrient composition except that the sodium content was changed episodically over 3 years from 75 to 35 to 120 mmol/d. In Bastrop, animals were divided into 2 groups; 1 group continued on the standard diet of 250 mmol/d sodium for 2 years, and sodium intake was halved for the other group. Lower sodium intake was associated with lower systolic, diastolic, and mean arterial blood pressures in Gabon (2-tailed P<0.001, unadjusted and adjusted for age, sex, and baseline weight) and Bastrop (P<0.01, unadjusted; P=0.08 to 0.10, adjusted), with no threshold down to 35 mmol/d sodium. For systolic pressure, estimates were -12.7 mm Hg (95% confidence interval, -16.9 to -8.5, adjusted) per 100 mmol/d lower sodium in Gabon and -10.9 mm Hg (95% confidence interval, -18.9 to -2.9, unadjusted) and -5.7 mm Hg (95% confidence interval, -12.2 to 0.7, adjusted) for sodium intake lower by 122 mmol/d in Bastrop. Baseline systolic pressures higher by 10 mm Hg were associated with larger falls in systolic pressure by 4.3/2.9 mm Hg in Gabon/Bastrop per 100 mmol/d lower sodium. CONCLUSIONS: These findings from an essentially single-variable experiment in the species closest to Homo sapiens with high intakes of calcium and potassium support intensified public health efforts to lower sodium intake in the human population.

[Personal identification with biometric and genetic methods]. / Identification des personnes par des analyses biométriques et génétiques.

The need for personal identification is growing in many avenues of society. To "identify" a person is to establish a link between his or her observed characteristics and those previously stored in a database. To "authenticate" is to decide whether or not someone is the person he or she claims to be. These two objectives can now be achieved by analysing biometric data and genetic prints. All biometric techniques proceed in several stages: acquisition of an image or physical parameters, encoding them with a mathematical model, comparing the results of this model with those contained in the database, and calculating the error risk. These techniques must be usable worldwide and must examine specific and permanent personal data. The most widely used are facial recognition, digital prints (flexion folds and dermatoglyphs, that offer the advantage of leaving marks), and the surface and texture of the iris. Other biometric techniques analyse behaviours such as walking, signing, typing, or speaking. Implanted radio-transmitters are another means of identification. All these systems are evaluated on the basis of the same parameters, namely the false rejection rate, the false acceptance rate, and the failure-to-enrol rate. The uses of biometrics are increasing and diversifying, and now include national and international identification systems, control of access to protected sites, criminal and victim identification, and transaction security. Genetic methods can identify individuals almost infallibly, based on short tandem repeats of 2-5 nucleotides, or microsatellites. The most recent kits analyze 11-16 independent autosomal markers. Mitochondrial DNA and Y chromosome DNA can also be analyzed. These genetic tests are currently used to identify suspected criminals or their victims from biological samples, and to establish paternity. Personal identification raises many ethical questions, however, such as when to create and how to use a database while preserving personal freedom? How to control access to genetic data? Do genetic polymorphisms delineate different human races? To what extent should different databases be interconnected? and What limits should be placed on individual files available on the web and on radiofrequency identification by implanted chips? A balance must be struck between the need to ensure the security of persons and transactions and the need to protect individual freedom and privacy.

[Pharmacogenetics and pharmacogenomics]. / Pharmacogénétique et pharmacogénomique.

Genetic polymorphisms can lead to drug adverse effects because certain allelic variants of genes that encode enzymes, targets or carriers involved in drug metabolism, are associated with an increase or a loss of function. Drug metabolism takes place essentially in the liver and is regulated by phase I enzymes (including several cytochrome P450 isoenzymes), the role of which is to make drug metabolites more polar by hydroxylation, and by phase II enzymes that catalyse conjugation reactions. Cytochromes P450 isoenzymes control 80% of oxidative reactions, owing to their low substrate specificity. The most extensively studied polymorphisms are those of CYP2D6 and CYP2C9, which are frequent and affect the metabolism of many drugs. For example, several CYP2C9 gene variants are associated with lower activity of the corresponding enzyme, potentially leading to drug overdose. Thiopurine methyl transferase and UDP-glucuronyl transferase are phase II enzymes that conjugate respectively 6-mercaptopurine metabolites with a methyl radical and metabolites of irinotecan (an anti-tumour drug) with a glucuronyl radical. Mutations in the corresponding genes can, through a loss of function, lead to excessively high levels of active metabolites, with a risk of bone marrow aplasia. The action of vitamin K antagonists is influenced by polymorphisms of vitamine K epoxyde reductase, the target molecule of vitamin K. A mutation in the methylene tetrahydrofolate reductase gene diminishes the folate pool and thereby increases the effects of methotrexate, a folic acid antagonist. Resistance to the anti-platelet effect of aspirin can be due to polymorphisms that affect other platelet aggregation pathways. Genotyping results must be confirmed by phenotyping, which examines the rate of transformation of a drug into its metabolites and shows whether the increase or decrease in this rate is linked to a specific polymorphism. Somatic mutations in malignant tumours can modify the response to anticancer drugs, and should therefore be taken into account. The National Academy of Medicine recommends:--development of genomic analyses for frequent polymorphisms in patients warranting treatment with drugs that have severe adverse effects;--collection of DNA samples from patients participating in drug trials in order to examine the possible relation between adverse effects and gene polymorphisms;--creation of biological resource centers in hospitals for the storage and analysis of tissue specimens.

[Generalized neonatal screening based on laboratory tests]. / Le dépistage neonatal généralisé par des tests d'analyse biologique.

Implementation of a generalized screening program for neonatal diseases must obey precise rules. The disease must be severe, recognizable at an early stage, amenable to an effective treatment, detectable with a non expensive and widely applicable test; it must also be a significant public health problem. Subjects with positive results must be offered immediate treatment or prevention. All screening programs must be regularly evaluated. In France, since 1978, a national screening program has been organized by a private association ("Association française pour le dépistage et la prévention des handicaps de l'enfant") and supervised by the "Caisse nationale d'assurance maladie" and "Direction Générale de la Sante". Five diseases are now included in the screening program: phenylketonuria, hypothyroidism, congenital adrenal hyperplasia, cystic fibrosis and sickle cell disease (the latter only in at-risk newborns). Toxoplasmosis is a particular problem because only the children of mothers who were not tested during the pregnancy or who seroconverted are screened. Neonatal screening for phenylketonuria and hypothyrodism is unanimously recommended. Screening for congenital adrenal hyperplasia is approved in most countries. Cases of sickle cell disease and cystic fibrosis are more complex because--not all children who carry the mutations develop severe forms;--there is no curative treatment;--parents may become anxious, even though the phenotype is sometimes mild or even asymptomatic. Supporters of screening stress the benefits of early diagnosis (which extends the life expectancy of these children, particularly in the case of sickle cell disease), the fact that it opens up the possibility of prenatal screening of future pregnancies, and the utility of informing heterozygous carriers identified by familial screening. Neonatal screening for other diseases is under discussion. Indeed, technical advances such as tandem mass spectrometry make it possible to detect about 50 diseases in a single run. In addition to issues of cost and organization, any increase in the number of screened diseases will raise ethical problems, such as how to inform parents of an incurable disease, a late-onset disease, or an entirely asymptomatic disorder. It is unanimously agreed that only Mendelian diseases should be screened for (excluding genetic polymorphisms). Analysis of the present situation suggests the following changes:--guidelines for choosing new diseases for neonatal screening should be updated;--all new screening programs should be tested locally before nationwide implementation;--an evaluation committee of paediatricians and epidemiologists should be created, and the children's long-term outcome should be studied;--the conditions in which heterozygous carriers are informed after familial investigations need to be precisely defined;--blood samples should be banked for epidemiological studies.

Gabriel Richet: the Man and the Scientist.

Gabriel Richet who died in Paris in October 2014 was the fourth of a brilliant dynasty of professors of medicine including a Nobel prize, his grandfather, Charles Richet. He behaved courageously during the Second World War and participated in the Campaign of France in 1940 and in the combats in the Vosges Mountains in 1945. His family participated in the resistance during the German occupation of France and three of his parents including his father, one of his brothers and one of his cousins were deported in Germany. At the end of the war, he was with Jean Hamburger the founder of French nephrology at Necker Hospital in Paris. He realized the first hemodialyses in France and was involved in the first allogenic transplantation that was not immediately rejected. From 1961 to 1985, he was the head of a school of nephrology at Tenon Hospital and attracted in his department many young collaborators and scientists. He was the first to describe the role of specialized cells of the collecting duct in the control of acid base equilibrium. He was the subject of a national and international recognition. Founding member of the International Society of Nephrology in 1960, he was elected his President from 1981-1984. His fame could be measured by the number of fellows and visiting facultiesfrom countries all over the world. When he retired in 1985, he left an important legacy involving several departments of nephrology directed by his ancient collaborators. After his retirement, he was an active member of the French Academy of Medicine and devoted much of his time to the history of medicine and, particularly, of nephrology. The main qualities of the man were his constant research of new ideas, his eagerness to work and his open mind to understand others.

AT1 receptor expression in glomeruli from NO-deficient rats.

Chronic inhibition of nitric oxide synthase promotes renin-dependent hypertension and renal injury. The present study examines how renal angiotensin II receptors are expressed in this model. N(G)-nitro-L-arginine methyl ester (L-NAME) was given orally to rats for 1 month and was associated or not with captopril during the 4 last days of the administration. 125I-[Sar1, Ile8]-Ang II binding, AT1)mRNA and cytosolic calcium were studied in isolated glomeruli from L-NAME and control rats and in cultured mesangial cells from normal rats. Renal injury was marked in rats receiving L-NAME. Type I angiotensin II (AT1) receptor number and mRNA expression were decreased (p < 0.05) in glomeruli isolated from L-NAME-treated rats compared with controls, unless they received captopril in combination. The low level of AT1 receptor expression was associated with an attenuated rise of cytosolic calcium in response to angiotensin II. Angiotensin-converting enzyme activity in glomeruli and angiotensin II concentration in renal cortex were increased (p < 0.05) in rats receiving L-NAME alone, whereas aminopeptidase A activity was not modified. To better discriminate between the direct and indirect effects of nitric oxide deficiency, rat mesangial cells were exposed or not for 24 h to S-nitroso-N-acetyl penicillamine, a nitric oxide donor. Angiotensin II binding, AT1 mRNA expression and calcium response to angiotensin II were decreased in presence of the nitric oxide donor (p < 0.01). These results suggest that the decrease of AT1 receptor expression after 1 month of L-NAME treatment does not depend on a direct effect of nitric oxide deficiency but results from the high local angiotensin II concentration due to the stimulated angiotensin-converting enzyme activity. They also show that the renin-angiotensin dependence of this model of hypertension does not result from the overexpression of AT1 receptors.

[Prevention and screening of chronic renal failure]. / Prévention et dépistage de l'insuffisance rénale chronique.

Chronic renal failure represents a major problem of public health. Incidence for patients arrived at the terminal stage of the disease is in France 126.4/million inhabitants and the cost of medical care reaches 2 % of the expenses of the National Health Insurance. The progression of the disease is divided into 5 stages that are defined by the level of creatinine clearance from the stage of renal diseases with a normal renal function (clearance>90 ml/min) to the terminal stage (clearance <15 ml/min). Prevalence of patients at this ultimate stage is around 50,000. Prevalence for the totality of patients with a renal disease is evaluated between 2 and 3 millions. Renal diseases must be screened because they are silent and because an early pre-dialysis nephrological care allows renal replacement therapy to be delayed and the number of cardiovascular accidents to be diminished. Screening must be performed in the high-risk populations, essentially patients with diabetes, hypertension, coronary ischemia, renal tract diseases and all subjects treated with drugs toxic for the kidneys. Screening in the total population seems inadequate because of a high cost to benefit ratio. Screening is based on testing for the presence of proteinuria, quantifying the number of formed elements and plasma creatinine determination, the latter allowing, together with age and weight, glomerular filtration rate to be evaluated according to Cockcroft's formula. Prevention of renal diseases in the whole population necessitates the same life style as that recommended for prevention of cardiac and metabolic diseases. In the high-risk populations, one must control glycemia, blood pressure and cholesterol plasma level. In patients that have been already screened, renal function decay has to be slowed down by blocking the renin angiotensin system with converting enzyme inhibitors, controlling plasma cholesterol with statins and diminishing dietary proteins. In the light of these various data, the National Academy of medicine recommends: 1 - in the field of public health, to extend to the whole country the registries containing data on patients with terminal chronic renal failure, to support the creation of medical networks for the screening of renal diseases, to vaccine the patients against hepatitis B, flue and pneumococcal infections and to verify whether a low birth weight is associated with a greater risk of renal diseases in adulthood; 2 - in the field of teaching and research, to stop the decrease in the number of nephrologists, to promote research in genetics, to evaluate the efficacy of antifibrosis drugs and the possible renal toxicity of all new drugs.

[Prostate cancer screening using prostate-specific antigen (PSA) determinations in plasma. National Academy of Medicine]. / Sur le dépistage du cancer de la prostate par le dosage de l'antigène spécifique de la prostate (PSA) dans le plasma. Académie nationale de médecine.

Prostate cancer is the most frequent cancer in man above 50 years. There is an increase in its incidence due to the longer life of the population. Prostate cancer is a slowly progressing disease. If life expectation is smaller than 10 years, the risk of death from another cause is greater than that from cancer whereas it is the opposite in younger patients. Therefore, screening of the disease by rectal examination and prostatic specific antigen (PSA) assay is necessary, confirmation being obtained by prostate biopsy. Total prostatectomy and radiotherapy can cure the disease or inhibit its progression. Plasma PSA is a general marker of prostate lesions. It is easy to measure and the cost of the assay is acceptable; but its specificity and its sensitivity remain too low. In order to improve these two parameters, it has been proposed to follow PSA kinetics and to measure the ratio free PSA/total PSA. Taken together, these data lead us to recommend, in agreement with the French Association of Urology, that a PSA assay be proposed and a rectal examination be performed every year by a general practitioner in men between 50 and 75 years and from 45 years in case of familial history. If an anomaly is found, the patient must take advice from an urologist who will decide which examinations and which treatment are to be proposed. Moreover, studies are necessary to compare the principal treatments in the long term, to precise the distribution with age of plasma PSA in the population and to improve the specificity and the sensitivity of the screening test.