Comprendre la dépression : apport de la psychologie évolutionniste

Darwinian medicine considers that many symptoms are the organism’s defence mechanisms and adaptations that have been inherited and shaped by natural selection. But in many cases, signs and symptoms of disease are of no benefit to human survival and are in fact deregulations of normal mechanisms. Evolutionary explanations help us understand how some human affective and emotional processes could have an adaptive value and enable us to cope with a wide spectrum of situations. But the wide range of intensity levels and different forms, ranging from low moods to major depression with psychotic features, suggest that these symptoms cannot always be explained by adaptation: where is the cut-off point? In this paper, we describe the evolutionary concepts related to adaptation as applied to the emotions, particularly focusing on low mood and depression, and discuss their possible functional and adaptive role.     

Origine et évolution des hominidés : Toumaï, une confirmation éclatante de la prédiction de Darwin

The earliest known hominid Sahelanthropus tchadensis Brunet et al., 2002, nicknamed Toumaï, from the Late Miocene (7 Ma) of Chad, displays a unique combination of primitive and derived characters which clearly shows that it is probably temporally close to the common ancestor of chimpanzees and humans. The Late Miocene Hominids: Sahelanthropus (Chad), Orrorin (Kenya), Ardipithecus (Ethiopia) are probably the ancestral group of Australopithecins from which the genus Homo appears between 2 and 3 Ma and then for the first time widespread in Eurasia. So, Toumaï seven millions years old confirms in a spectacular way the prediction Charles Darwin made in 1871.     

Conséquences de la chimiothérapie anticancéreuse sur la fertilité de la femme

Sterility is a potential toxic effect of chemotherapy. This risk is well established for alkylating agents, but is less clearly defined for anthracyclines, methotrexate and fluorouracil and poorly defined for alkaloids, platinum, etoposide and taxanes. The main predictive factors for ovarian toxicity are the additive effect of cytotoxic drugs, the cumulative dose of each drug and the patient’s age. This effect of chemotherapy is evaluated on menstrual cycles, hormonal assays and the number of pregnancies observed in patient cohorts. Chemotherapy induces destruction of oocytes and granulosa cells. In mice, it has been shown that adriamycin may induce oocyte apoptosis, which can be prevented by modulation of cycle cell signalling (dysregulation of Bax gene or, on the contrary, expression of its antagonist gene Bcl-2 or inhibition of apoptosis with sphingosine-1-phosphate or caspase inhibitors). Clinical data in the literature are usually based on retrospective studies and are somewhat confused: global fertility after MOPP chemotherapy for Hodgkin’s disease is about 20%, adjuvant chemotherapy with CMF, F(A)C or TAC for breast cancer induces amenorrhea in 50% to 70% of cases, PVB or BEP chemotherapy for ovarian germ cell tumors has little effect on fertility when the uterus and one ovary can be preserved, and the majority of women treated with methotrexate, actinomycin D or various combinations for persistent trophoblastic disease remain fertile. Preservation of fertility is a major goal for cancer patients receiving chemotherapy: in vitro fertilization could preserve the couple’s fertility, but is usually not feasible as it would delay initiation of chemotherapy until after stimulation of ovulation; oocyte or ovarian tissue cryopreservation is at the stage of research; oral contraceptives have not been demonstrated to be effective to preserve ovarian function; gonadotropin releasing hormone (GnRH) agonists prevent cyclophosphamide toxicity in rat and monkey ovaries, and a few pilot clinical studies suggest that chemotherapy-induced amenorrhea could be prevented by administration of GnRH analogues simultaneously to chemotherapy, but randomised studies are necessary.     

Intérêt de la ponction épididymaire et de la biopsie testiculaire systématique dans la prise en charge de l’azoospermie obstructive

Introduction

In obstructive azoospermia (OA), even if spermatozoa recovery rate are high, pregnancy rates could be lower as expected. When almost surgeons stop if they could find motile spermatozoa in the epididymis after microsurgical epididymal sperm aspiration (MESA), in our center, we add systematically a testicular biopsy with testicular sperm extraction (TESE). What are our sperm extraction rates in MESA or TESE? Are pregnancy and miscarriage rates different regarding the sperm origin?

Material and methods

A retrospective study including 48 infertile couples with ICSI because of OA. Between 2003 and 2011, each patient had a complete aetiological exploration and a surgery with the association of MESA and TESE. ICSI were asynchronous. Each time it was possible, ICSI was realized first with epididymal spermatozoa.

Results

For 48 couples, 99 ICSI were realized. Fifteen couples had 24 ICSI-TESE because no spermatozoon was found in MESA. Eleven couples had 20 ICSI-TESE because of bad quality of sperm recovered with MESA. Twenty-two couples had 22 ICSI-MESA in first intention. If failed, 11 couples had continued with 12 ICSI-MESA and 10 with 20 ICSI-TESE. Although the number of injected oocytes (7,1±4,1 vs 6,9 ±3,6 P: 0,8) and embryos (4,5±3,0 vs 4,7±2,7; P: 0,7) were not significantly different in the two ICSI groups, the number of top quality embryos (2,4±1,9 vs 3,6±2,0 P: 0,005) and frozen embryos (0,9±1,8 vs 1,7±1,9 P: 0,04) were higher in the ICSI-TESE group. Pregnancy rate per punction (58,5% vs 26,5%, P: 0,002) was higher when testicular spermatozoa were used.

Conclusion

Our approach is original with the systematic association of MESA and TESE for each OA man, when others stop surgery when they can find spermatozoa with MESA. We found that more than the half of epididymal explorations were not useful because negative or of bad quality. Embryo quality and per punction pregnancy rate were better with testicular spermatozoa. Association of MESA and TESE could improve the management of these infertile men without exposing them to an over surgical risk.     

Mensurations échographiques de la thyroïde chez des enfants de zéro à 15 ans de la ville de Ouagadougou

Among the methods used to carry out measurements of thyroid, echography is the best because it is noninvasive and more specific. The goals of this study were to determine the normal thyroid volume of the Burkinabe child; to study the parameters which induce a variation of thyroid volume and to compare our values with those from other localities. Through a cross-sectional study, 240 children from the town of Ouagadougou benefited from a thyroid echography. Thus the height (h), the transverse diameter (dt) and the thickness (e) were measured. Volume (vl) of each lobe was estimated by: vl = h × dt × e × 3.14/6. The total volume (VT) is the sum of the volumes of each lobe, the isthmus being neglected. A correlation set at the threshold p < 0.001 has been carried out between VT and some anthropometric parameters. The following averages were observed: before one year, the average volume is of 0.51 L ± 0.21; from one to three years, it is of 0.95 mL ± 0.33; from four to six years, the average volume is of 1.35 mL ± 0.43; from seven to nine years, it is of 1.95 mL ± 0.62. From 10 to 12 years, the average volume is of 3.01 mL ± 1.08 and it is of 5.32 mL ± 2.07 from 13 to 15 years. It stands out that the VT is positively associated with the age (r = 0.82), with the size (r = 0.73), with the weight (r = 0.81) and with body surface (r = 0.78). Moreover, the VT is higher among boys than in girls beyond one year of age. This parameter varies according to the area of origin. Lastly, compared with the American, European and Asian averages, our values are smaller. This study enabled us to establish our own standards which we will be able from now on to use in daily practice. However, multicentric studies associated with thyroid and sexual hormones blood levels measurements must be undertaken to ascertain these data.     

Étude en microscopie électronique et par cytophotométrie à balayage de la structure et de la distribution de la chromatine dans les noyaux des cellules cartilagineuses deTriturus cristatus âgés au cours de la régénération

Résumé Les cellules cartilagineuses des membres postérieurs deTriturus cristatus en régénération après amputation, ont été étudiées en microscopie électronique et par cytophotométrie à balayage. Nous nous sommes intéressés à la structure et à la distribution de la chromatine mais aussi à différents organites cytoplasmiques. Dans l'étude de cytophotométrie à balayage, la chromatine a été considérée à travers son constituant majeur, l'ADN, coloré par la réaction de Feulgen. Au cours de la régénération du membre, l'hétérochromatine initialement condensée, essentiellement accolée à la membrane nucléaire se décondense. Les vacuoles du cytoplasme, caractéristiques des animaux âgés par rapport aux animaux jeunes, disparaissent, les mitochondries et le reticulum endoplasmique rugueux deviennent plus abondants. Les caractéristiques nucléaires de l'activation cellulaire apparaissent précocement, précédent les modifications cytoplasmiques et conduisent à des cellules en tous points identiques aux cellules d'animaux jeunes en dehors de tout processus régénératif. Cette phase d'euchromatisation et de restructuration cytoplasmique est peut-être nécessaire à l'accroissement d'activité métabolique et à la division cellulaire qui suivent. Son déroulement peut expliquer tout au moins le ralentissement de la régénération observé chez les animaux âgés par rapport aux animaux jeunes.

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Electron microscopic and scanning cytophotometric study of chromatin structure and distribution in nuclei of cartilaginous cells of agedTriturus cristatus during regeneration

Summary Cartilaginous cells of aged newts (Triturus cristatus) were studied during hind limb regeneration. The electron microscope was used to study the structure and distribution of chromatin in the cell nuclei, while the DNA content of the chromatin was measured by means of a scanning cytophotometer.Changes in the ultrastructure of the cytoplasm during regeneration were also studied.It was observed that the structure and distribution of chromatin in the activated cell is greatly modified. In the non-activated cell of the aged newt, the chromatin is found highly condensed and distributed peripherally close to the nuclear membrane. In contrast, in the activated cells, the chromatin is much less condensed and is distributed throughout the nucleus. Moreover, cytoplasmic vacuoles, found only in the non-activated aged cells, disappear and an increase in the mitochondria and rough endoplasmic reticulum is also observed.Changes in the nuclear structure are observed prior to the cytoplasmic modifications.It is interesting to note that the process of activation induces structural changes in the aged cells which make these cells appear to be structurally identical to the young cells. This process of rejuvenation takes 3–5 days in the newt.We suggest that these structural changes of the chromatin and cytoplasm in the aged cells are necessary to increase the metabolic activity which precedes cell division. It may also explain why regeneration takes a longer time in the aged animals than in the young ones.

     

Influence d'une lame métallique sur la distribution de la dose dans le plexiglas irradié par des électrons de haute énergie

Résumé Une lame hétérogène deZ plus élevé que celui de l'eau, provoque dans un faisceau d'électrons de haute énergie une modification de la distribution de la dose en profondeur.La dose est augmentée au contact et au voisinage immédiat de la lame hétérogène, tandis qu'elle est diminuée à plus grande distance.Dans le cas habituel de la radiothérapie, où la lame hétérogène est constituée par une épaisseur limitée d'os, et de l'expérimentation radiobiologique, où l'hétérogénéité est constituée par les parois de verre, le surdosage reste inférieur à 5% pour les électrons d'énergie comprise entre 10 et 20 MeV.La distribution de la dose en profondeur est approximativement représentée par la courbe standard, si les profondeurs sont exprimées en masse surfacique (g/cm²).On peut donc admettre une épaisseur d'absorption équivalente (A E T) égale à l'épaisseur réelle multipliée par la densité de la lame hétérogène.Cependant dans les expérimentations rigoureuses qui exigent une précision élevée, le calcul de la dose en profondeur par l'A E T, peut ne pas être satisfaisante, et la mesure directe est indispensable.     

Étude de la variabilité de la clairance hépatique de la mébrofénine-99mTc en scintigraphie hépatobiliaire

AimThe purpose of this study was to investigate some of the parameters likely to influence mebrofenin-^99mTc hepatic clearance calculation and inter-and intra-observers reproducibility.Materials and methodsHepatic clearance (%/min m²) of 30 scintigraphies was calculated from the values of hepatic, cardiac, and total activities, according to the method recommended in the literature. We studied: 1) impact of injection–acquisition delay variations; 2) acquisition type: anterior face only (FA) or geometric mean (GM); 3) clearances calculated according to four different body surface area (BSA) formulas; 4) intra-and inter-observers reproducibility for three observers (two evaluations for each observer).Results1) Clearance differences between different studied intervals were statistically significant, more important if the studied interval was far from reference interval (150–350 secondes) and even more when the interval studied was too early (110–310 secondes). 2) There was a statistically significant difference between clearance calculated using either FA or GM datasets (0.85 %/min m²). 3) There were small but statistically significant differences for four of the clearance comparisons using different BSA formulas. 4) Despite differences in size of cardiac and hepatic regions of interest (ROI), intra-observer reproducibility of hepatic clearance was excellent for each observer. Inter-observers reproducibility was also excellent (r = 0.982).ConclusionHepatic clearance of mebrofenin-^99mTc appears to be a highly reproducible method provided that acquisition and clearance calculation are standardized. It provides additionnal functional information to morphological and biological data usually performed before major hepatectomy. Thereby, the definition of a standardized protocol would enable realization of multicentric studies.     

Mise en évidence et évaluation des “moyennes molécules” de la taille de la vitamine B12 présentes dans les liquides biologiques de sujets normaux et de patients urémiques

Determination of “middle molecules” presenting vitamin B₁₂ molecular size in normal and uremic body fluidsUremic solutes with the molecular size of vitamin B₁₂ are assumed to be toxic. An analytical method is proposed to detect and separate these solutes in body fluids using two combined techniques: gel filtration on Sephadex G-15 and ion-exchange chromatography on DEAE-Sephadex A-25. The vitamin B₁₂ molecular size has been localized by ultrafiltration through membranes with a defined cut-off. Normal and uremic body fluids (urine, plasma, hemodialysis fluid) have been separated into 9 ultraviolet-absorbing peaks (a to i) by high-speed gel filtration. Peaks b and e present the molecular size of vitamin B₁₂, 10–15 Å molecular diameter in pH 7 aqueous solution. Peak b, which correlates with uremic neuropathy, is separated into 6 sub-peaks (b₁ to b₆) by ion-exchange chromatography, sub-peak b_4.2 is the only one to correlate with uremic neuropathy. The coefficient of variation in the integrated area of a single peak is 16%. This method gives the chromatographic profile of the vitamin B₁₂ molecular size content from 500 μl of uremic plasma or 100 μl of normal urine within one hour.     

Epidémiologie de la dysfonction érectile (2ème partie). Facteurs de risque

Epidemiological studies in the general population or target populations in several countries in the world have revealed a large number of risk factors for erectile dysfunction: diabetes mellitus, hypertension, smoking, dyslipidaemia, cardiovascular diseases, psychological disorders, certain medications, chronic renal failure, socioeconomic factors and lifestyle, obesity, lower urinary tract symptoms, poor health and bicycling. Cardiovascular risk factors are predictors of erectile dysfunction and erectile dysfunction is now considered to be a manifestation of vascular disease. Further studies are necessary to establish the pathophysiological mechanisms of certain risk factors and the possible value of preventive measures.