Utilisation préhistorique de la technique minière d’abattage au feu dans le district cuprifère de Cabrières (Hérault)

Fire-setting to open up mines has been used on hard rock since prehistoric times. In the copper-mining district of Cabrières, the existence of metre-sized spherical or sub-spherical cavities, sometimes spaced along the same vertical in an ore seam, has usually been ascribed to this method 〚12〛, 〚13〛, 〚20〛. Two AMS ¹⁴C dating of micro-charcoal found in dolomite and of burnt ore breccias related to extraction in these cavities give the ages 3830 ± 40 BP, cal BC 2340–2130 and 3900 ± 40 BP, cal BC 2480–2280, which is the first evidence in France of the use of fire-setting in prehistoric mines.     

Facteurs impliqués dans le remodelage de la chromatine au cours de la spermiogenèse

Round spermatids are post-meiotic cells with a haploid genome contained in a nucleus, with a structure initially similar to that of the somatic cell nucleus. During spermatogenesis, the spermatid nucleus undergoes drastic remodelling during which it first elongates and then condenses into the very specific and tightly packaged structure of the sperm nucleus. During this remodelling dthe histones are replaced by transition proteins, which, in turn, are replaced by protamines, the specific nuclear proteins of the spermatozoa. Immediately prior to their replacement, the histones are hyperacetylated. The first part of our work was to precisely characterise the changes in histone acetylation during murine spermatogenesis. We have shown that the core histones H2A, H2B, H3 and H4 are hyperacetylated in the elongating spermatids. We have also shown that these changes in acetylation are associated with degradation of the enzymes responsible for histone deacetylation, histone deacetylases or HDACs, while histone acetyl transferases are still present in these cells. The histone acetylation pattern was also investigated during human spermatogenesis, revealing that histone hyperacetylation in the nucleus of elongating spermatids, which appears to be conserved during the course of evolution, also occurs during human spermatogenesis. Moreover, our data obtained from the testes of men with severely altered spermatogenesis, including SCO syndromes (Sertoli Cells Only Syndromes), show that a global hyperacetylation of the Sertoli cell nuclei is associated with an absence of meiotic and post-meiotic cells. This suggests that the global histone acetylation variations observed during spermatogenesis are part of a signalling pathway involving germ cell — Sertoli cell communication. Altogether, these data provide a basis for a better understanding of the mechanisms and identification of the factors involved in post-meiotic remodelling of chromatin.     

Étude expérimentale des variations de la teneur en eau au cours de la déshydratation et de la réhydratation chez la Fougère:Notochlaena vellea R. Br.

Experimental Study of changes in water content during dehydration and rehydration of the Fern: Notochlaena vellea R. Br.—This study takes place after studies made on otherPolypodiaceen Ferns. We have shown that, in these ferns, the survival duration was longer for the subterranean organs than for aerial ones. The problem was to show that this difference is due to a lower dehydration of the subterranean tissues. As far as we looked at the total water deficiency, we did not find any significant difference between the leaves and the meristematic parts of the subterranean organs: the main difference is the rate of rehydration which is higher in subterranean parts.     

Apoptose au cours de la spermatogenèse et dans le sperme éjaculé

It has become clear in recent years that programmed cell death occurs spontaneously in the cycle of the seminiferous epithelium. Induced germ cell apoptosis occurs at specific stages of the spermatogenic cycle and the existence of supracellular control of germ cell death during spermatogenesis has been documented. If apoptosis is a key phenomenon in the control of sperm production, the existence and role of apoptosis in ejaculated sperm cells remain controversial. Apoptosis — as determined by DNA fragmentation (TUNEL) and ultrastructural analysis — is abnormally frequent in the sperm cells of the ejaculate of sterile men with classical biochemical and ultrastructural pattern. In this review, we discuss the possible origins of DNA damage in ejaculated human spermatozoa and the consequences of DNA damage if the apoptotic spermatozoa is used for ICSI. Percentages of DNA fragmentation in human ejaculated sperm are correlated with fertilization rates both after FIV and ICSI. Detection of DNA fragmentation in human sperm could provide additional information about the biochemical integrity of sperm and may be used in future studies for fertilization failures not explained by conventional sperm parameters. However, the analysis of other molecular markers of apoptosis (Fas, Annexine V ...) is necessary to assess the role of apoptosis in human ejaculated sperm cells.     

Synthèse d'ARN dans le chondriome au cours de la spermiogenèse chez la Drosophile

Résumé L'incorporation d'uridine-³H dans l'ARN nucléaire et dans l'ARN mitochondrial est détectée à l'aide de l'autoradiographie à haute résolution au cours de la spermiogenèse chez la Drosophile.Le marquage apparaît simultanément sur le noyau et sur le chondriome jusqu'au début de la condensation de la chromatine. Le nebenkern, qui caractérise un des premiers stades de la spermiogenèse, est le territoire cellulaire le plus radioactif. La synthèse de l'ARN nucléaire cesse au cours de la condensation de la chromatine. Pendant ce temps, le marquage des dérivés mitochondriaux se poursuit; il persiste jusqu'à leur complète transformation en paracristal. Ces observations mettent en évidence une synthèse autonome d'ARN par les mitochondries à la fin de la spermiogenèse.

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Autonomous mitochondrial RNA synthesis during spermiogenesis in Drosophila

Summary The incorporation of ³H-uridine into nuclear and mitochondrial RNA has been followed by electron microscope autoradiography during spermiogenesis in Drosophila.Nuclei and mitochondria are simultaneously labeled up to the beginning of the chromatin condensation. The nebenkern, characteristic of the first stages of spermiogenesis, is the most radioactive cellular component. During chromatin condensation, nuclear RNA synthesis ceases, but mitochondrial derivatives continue to be significantly labeled up to their complete paracrystalline transformation. These data show an autonomous RNA synthesis by mitochondria at the end of spermiogenesis.

Ce travail a bénéficié de l'aide du C.N.R.S. (E.R.A. 174), de la D.R.M.E. (contrat 70/414) et du C.E.A. (participation à l'achat de molécules marquées).     

Influence de la lumière et de la mycosporine sur la composition stérolique du Nectria galligena au cours de la morphogenese sexuée

The nature and content of free sterols, analyzed by MIKE spectrometry, were investigated in in vitro cultures submitted to different light regimes with or without the addition of exogenous mycosporin. The sterol composition was related to varying degrees of induced sexual morphogenesis, particularly when mycosporin was added to the nutrient medium.     

Étude cinétique de l'hypersensibilité de type retardé dans la candidose expérimentale de la souris

Mice were inoculated with different quantities of blastospores ofCandida albicans by subcutaneous or intravenous ways. Delayed hypersensitivity was then studied during the course of infection by means of the inhibition of macrophage spreading test. In the same time retrocultures were done from kidney material, target organs in the experimental candidiasis. The results obtained in this way enabled the authors to think that cellular immunity plays a role in this experimental model as described by Mackaness.

Travail de l'Unité 42 de l'INSERM et du Groupe de Mycologie Fondamentale et Appliquée de LILLE.     

Diminution de la capacité de surfusion au cours de l'embryogenèse et du développement larvaire chez un coléoptère

Potential cold resistance of non-diapause eggs and first instar larvae of Osmoderma eremita (Coleoptera, Cetoniidae, Trichiinae) during embryogenesis and post-embryonic growth was assessed by measuring individual supercooling points (SCP): sterile eggs had a mean SCP of −24.3 ± 2.0 °C; fertilized newly laid eggs a mean SCP of −23.4 ± 3.2 °C and eggs about to hatch a mean SCP of −9.2 ± 2.9 °C. Water absorption by fertilized eggs is a necessary requirement for the development of the embryo and results in an increase in weight and water content: fertilized newly laid eggs had a mean fresh weight of 10.687 ± 1.072 mg and a mean water content (expressed as a percentage of the dry weight) of 79.5 ± 10.83%; eggs about to hatch had a mean fresh weight of 19.127 ± 3.183 mg and a mean water content of 250.10 ± 74.15%. The ex-ovo larvae, hatched 30 days after oviposition, had a mean SCP of −10.1 ± 3.6 °C (no significant difference with eggs about to hatch) and had gained in weight (24.845 ± 3.911 mg) and in water content (499.72 ± 55.49%). Feeding 1st instar larvae had a decreased supercooling ability (mean SCP = −5.7 ± 0.4 °C) whereas their mean fresh weight (99.858 ± 53.091 mg) and mean water content (665.83 ± 82.74%) increased. The eggs and larvae of O. eremita are freezing intolerant. Before overwintering, all larvae switch to being freezing tolerant and can survive ice formation in their tissues and body fluids, whereas their mean SCP stays at around −5 °C. However, recent experiments in the winter of 1996 have shown that frozen larva mortality does occur at temperatures lower than about −12 °C.     

Étude au microscope électronique de la pathogénèse intracellulaire rickettsienne chezMelolontha melolontha L.

Summary On ultra fine cross sections of adipeous tissues ofMelolontha melolontha taken at the successive stages of rickettsial infection the evolution of the pathogenesis in the cytoplasm was followed with electronic miscrocope. The appearance of the first lesions and the multiplication of the rickettsies in cytoplasmic groups were shown. A geometric ordening of the rickettsies was revealed in the heaps of rickettsies that were in the course of multiplying, leading to the formation of closely packed groups in the form of ?globular centers?. The internal structure of these formations and of intracellular cystals is analyzed and research on their significance in compared pathology is being carried out.      

Place de l’embolisation percutanée de la varicocèle dans le traitement de l’infertilité

Objectives

To describe percutaneous embolization of varicocele and to evaluate the effect on fertility disorders.

Materials and methods

One hundred nineteen patients, aged 11 to 48 years, underwent percutaneous embolization for varicocele indicated by a fertility disorder in 23% of cases. Correction of the varicocele and resolution of associated pain, improvement of testicular trophicity and the effect on fertility were studied and a review of the literature was performed.

Results

Percutaneous embolization was performed using neuroleptanalgesia on an outpatient basis. The technique combined venous sclerotherapy and placement of coils in the gonadal vein. The technique was successful in 95% of cases and one complication was observed. At 3 months, the varicocele and related pain had resolved in 98% of treated patients. According to previous reports in the literature, the relations between varicocele and fertility disorders are still unclear, but improvement of fertility (semen quality and conception rates) after varicocele repair has been established.

Conclusion

Although the consequences of varicocele on fertility have not been fully elucidated, treatment of varicocele appears to be beneficial. Percutaneous embolization of varicocele is a safe and effective alternative to surgery. This technique, based on a urological and radiological consensus, is the first-line treatment for varicocele in our institution.     

Rôle du pore basal dans la germination du glomérule de Betterave sucrière

Anatomical analysis of the sugar-beet seed ball indicates two possible ways for the entrance of water and oxygen during germination: cells from the operculum periphery and cells from the basal pore characterized by absence of lignin and a thin layer of cellulose. Impermeabilisation of these zones by vaseline considerably reduces the percentage of germination and stresses the major role played by the basal pore. This can also be confirmed by variation in the germination percentage when sowing the seed ball with the basal pore up or down to the substrate.     

Étude de la cytodifférenciation du rein de l'Epinoche femelle après traitement par la méthyltestostérone

Résumé Au microscope électronique, l'action de la méthyltestostérone sur les cellules rénales de l'Epinoche femelle se traduit par une cytodifférenciation conduisant à la formation de cellules glandulaires muqueuses. Elle a lieu simultanément à deux niveaux distincts:Au niveau du tubule proximal, le premier signe visible de cytodifférenciation est une activation du nucléole, accompagnée par une augmentation de taille des cellules. Puis on assiste à un développement de l'ergastoplasme et de l'appareil de Golgi et à l'élaboration de deux types de sécrétions: d'abord des granules de 2000–2500 Å, ensuite des grains de mucigène typiques, qui subissent rapidement une transformation muqueuse.Une cytodifférenciation régressive intervient en même temps. Elle concerne la pinocytose apicale qui disparaît.Au niveau des tubules collecteurs, la cytodifférenciation se traduit par la formation d'un mucus hyalin d'origine golgienne. Elle s'accompagne également d'une disparition de la pinocytose.La méthyltestostérone est capable de provoquer, chez la femelle, une cytodifférenciation rénale identique à celle que l'on observe chez le mâle pendant la période de reproduction. La transformation muqueuse des cellules rénales est donc sous le contrôle de la seule testostérone, qui déclenche au niveau cellulaire un ensemble de processus conduisant à la formation de mucus.Au microscope électronique, on constate que l'élaboration de mucus prêt à l'excrétion est achevée au bout de trois jours dans les tubules proximaux alors que dans les tubules collecteurs elle ne demande que 24 heures.

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Action of methyl testosterone on the cytodifferentiation of the kidney of the female three-spined Stickleback

Summary At the microscopic level, the action of methyl testosterone on the cells of the kidney of the female three-spined Stickleback gives raise to a cytodifferentiation which leads to the formation of mucous glandular cells. This action is evident at two different levels:At the level of the proximal tubule, the first visible sign of cytodifferentiation is an activation of the nucleolus, accompanied by a growth of the cell size. Then a rapid development of the ergastoplasm and the Golgi apparatus takes place, which leads to the elaboration of two types of secretory particles: granules of 2000–2500 Å in diameter appear first, then typical mucigen granules become visible. These latter undergo a rapid mucous transformation.A regressive cytodifferentiation occurs at the same time. It concerns the apical pinocytosis which disappears in the cells undergoing the glandular differentiation.At the level of the collecting tubules, the cytodifferentiation is characterized by the elaboration of a clear mucus which originates in the Golgi apparatus and migrates to the apex of the cells. A disappearance of the pinocytosis is also noticeable.In the kidney of the female, methyl testosterone induces a cytodifferentiation which is identical to that occuring in the male during the breeding period. So the mucous transformation of renal cells is under the control of a single hormone: the testosterone, which is able to give raise to a succession of phenomena leading to the formation of a mucous secretion.With the electron microscope, it is possible to demonstrate that three days are necessary for the elaboration of the mucus ready to be discharged in the lumen of the renal proximal tubules. In the collecting tubules, the reaction occurs more quickly, after only two days of treatment.

L'auteur tient à remercier Monsieur le Professeur E. Follénius pour ses conseils et son aide précieuse au cours de la réalisation de ce travail.     

Apport de la TEP/TDM au 18FDG dans le bilan préopératoire des phéochromocytomes. Étude rétrospective comparative par rapport à la scintigraphie à la MIBG

Pheochromocytomas (PHEO) are tumors arisen from the adrenal medulla, with a high secretory risk. Malignancy is rare and difficult to establish before metastastic spread. The risk of multifocality becomes greater whether genetic predisposition exists. MIBG scintigraphy is the reference functional imaging of PHEO. The place of 18FDG PET/CT is not well-established in literature. Our study retrospectively analyzes patients operated for a PHEO and who underwent both MIBG and 18FDG PET/CT before surgery, between 2007 and 2015. On the 49 patients included (52 lesions), among them 13 had genetic mutation, MIBG detected 39 lesions (75%) and 18FDG PET/CT forty-eight (92%), enabling a combined sensitivity of 98%. Sensitivity was not affected by the predominant secretion (metanephrine or normetanephrine), whereas MIBG-negative lesions showed a higher proliferation index (Ki67) than MIBG-positive lesions (6.6 vs. 2.8; P = 0.0044). FDG PET/CT semi-quantitative indices vary with the germline mutation status and were significantly higher for Cluster 1 lesions (SDHx, VHL or FH mutations) than for any other lesions (SUVmax = 27.73 vs. 5.92 for the others mutations (Cluster 2), 9.53 for lesions without mutation and 3.78 for undetermined lesions; P = 0.002). In conclusion, because of their capacity to take up FDG, 18FDG PET/CT could be useful in the preoperative imaging of PHEO, especially when MIBG is not contributive or when F-DOPA PET/CT is not available. An intense FDG uptake may orient to a Cluster 1 mutation.