Notions nouvelles sur la cytologie de l'antehypophyse chez le rat

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Observations nouvelles sur quelquesUlva

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Donnees histo-pyhsiologiques sur la neurosecretion chez les Paleopteres (Ephemeropteres et Odonates)

Sans résuméRapport présenté au I ^er Congrès international sur la neuro-sécrétion, a Naples.     

Observations sur les signaux préparatoires à l'alimentation des larves chez la fourmi ponérinePachycondyla caffraria (Smith)

Résumé Dans les sociétés dePachycondyla caffraria les ouvrières nourrices regroupent les larves qui ont redressé leur région antérieure à la suite des palpations antennaires reçues, puis les nourrissent. Nous avons pu montrer expérimentalement que cette réaction de redressement de l'avant du corps est le seul indice qui permette aux ouvrières de reconnaître les larves affamées. Elles ne savent pas déceler les larves qu'elles n'ont pas sélectionnées à ce moment, si celles-ci ont expérimentalement été placées dans le groupe des larves qu'elles vont nourrir.

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Observations on the signals preparing for larval feeding in the ponerine ant Pachycondyla caffraria (Smith)

Summary In colonies ofPachycondyla caffraria the nurse workers gather together the larvae which lift the anterior part of their body as a result of the antennal palpation they receive, and then feed them. We have shown experimentally that this response of raising the anterior part of the body is the only signal by which workers are able to recognize hungry larvae. They are not able to detect larvae they have not selected, as follows from experiments in which such larvae are placed in the group of larvae that they are about to feed.

     

Prévalence de la pyospermie et retentissement sur la qualite du sperme chez les hommes infertiles

There are numerous controverses concerning the relationship between the presence of leukocytes in semen and male infertility. In the aim to determine the impact of pyospermia on sperm quality, we have realised a retrospective study in which we analysed and compared semen parameters and abnormalities frequencies between pyospermic and non pyospermic infertile patients. 833 spermiograms were included in this study. They were done in accord with WHO method. Leucocytes identification was performed by cyto-enzymologic method that reveals myelo-peroxydase in polymorphonuclear granulations. Pyospermia was considered when number of leucocytes was more than one million per millititre of sperm. The non pyospermic group was composed by sperm with leucocytospermia less than 50.000 per millilitre. The prevalence of pyospermia was 5.88%. There was not significative difference of semen parameters (volume, motility, morphology, number of spermatozoa and viability) between pyospermic and non pyospermic groups. In the other hand, no correlation was found between leucospermia and semen parameters. However, oligospermia was significantly more frequent in pyospermic group (40.8%) than in non pyospermic group (20,3%). Inversly, the frequence of teratospermia was significantly higher in non pyospermic group (47.2% vs 34.1%, p<0,05). These results suggest that inflammation and/or infection associated with pyospermia is complicated by reduction of spermatic ducts permeability. Although, the leucocytes would act in removing amorphous gametes by phagocytosis. No relationship was established between pyospermia and infection. In future, a prospective study would be done with exhaustive exploration of pyospermia etiology, with hopes to clarify the true link with infection and autoimmune reaction and to determine the effect of pyospermia on glandular activities in male genital tract and on functional properties of spermatozoa.     

Effet de la farnesylacetone sur les syntheses proteiques de l'ovaire chez le crabe Carcinus maenas

Summary

We have analysed in vitro the effect of farnesylacetone, a substance produced by the androgenic gland of Crustacea, in a concentration of 20 ng/ml, on the protein synthesis in the ovary of Carcinus maenas. In winter, the farneslyacetone seems to be ineffective; the incorporation of labelled precursor per mass unity is then related to the weight of the sample. In summer, an activation of protein synthesis can be observed. These results do not depend on ovary maturation and concern all the proteins of the gonad.     

Observations sur les Esthéries de la Lettenkohle (Passage muschelkalk-keuper) dans les vosges moyennes

New outcrops in the Rambervillers and Mirecourt area (Vosges) have provided a fine Estherian fauna in Lettenkohle horizons. Euestheria minuta and E. laxitexta lived together, E. minuta being the most numerous species, thoughout the Middle Lettenkohle, when the environment was favorable.     

Observations sur un pigment de membrane chez phycomyces

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Interactions d’une restriction calorique avec les effets du Nickel sur la reproduction chez le rat

Human epidemiological studies have demonstrated signs of a reduction, since 1960, of several parameters of the sperm count with an increase of certain male genital tract diseases. The increasing contamination of the environment by chemical compounds appears to be an aetiological factor. Various authors have also proposed the hypothesis that caloric restriction has a beneficial effect on health or longevity. This study was deisgned to compare the effects of nickel on the reproductive functions of rats fed either daily or every second day, in order to evaluate the possible beneficial effects of caloric restriction on rat fertility. This study was conducted with male and female Wistar rats, fed either daily (N), or every second day: intermittent fasting (F). After one month of this treatment, (N) and (F) rats were divided into 2 groups: one group received tap water (NO and FO groups), and the other received the same water enriched with nickel chloride (100 mg/L, NNi and FNi groups). Intermittent fasting was continued in parallel with nickel treatment with for 2, 4, 10, 16, 30 and 60 days. To study malonic dialdehyde (MDA) levels, nickel was administered by intraperitoneal injection at the dosage of 4 mg NiCl₂/kg of body weight for 1, 3, 5 and 10 days. Our results show that nickel induces atrophy of the seminiferous tubules with a reduction of the sperm count and a reduction of serum testosterone levels. A reduction of the number of ovarian follicles was observed in females. Intermittent fasting induced the same types of disturbances with more marked reductions of the number of mobile spermatozoa and serum festosterone levels than those observed after exposure to nickel. The combination of the two factors, fasting and nickel, did not amplify these effects. Analysis of intergroup crosses showed that the pregnancy rate and especially the mean number of implantations were decreased in rats exposed to nickel and/or submitted to intermittent fasting. The lowest pregnancy rate (55%) was observed in (NNi) females crossed with (NO) control males. The smallest number of implantations was observed in (NO) control females crossed with (NNi) males. Nickel did not induce any additional reduction of fertility in rats submitted to intermittent fasting. MDA assays showed that nickel induces lipid peroxidation in ovarian and uterine tissues. However, the relative increase of the MDA level was lower in FNi than NNi rats, i.e. when nickel was associated with intermittent fasting. Our results suggest that nickel and intermittent fasting decrease fertility in rats via two different mechanisms whose effects are not additive. When associated with intermittent fasting, nickel becomes non-toxic, as confirmed by montoring of MDA levels. The low-calorie effect of intermittent fasting could be responsible for inhibition of the cytotoxic effects of metallic nickel classified as an oxidative stress.     

Données nouvelles sur la paléoflore de Colombie

From samples collected during two missions in Columbia and from samples stored at the University of Medellin, are successively described three fossile floras: a poor and fragmentary Devonian flora from Floresta, a rich Upper Jurassic flora from the «Formación Valle Alto in the Central Cordillera composed of Ferns, Bennettitales, Cycadales and Caytoniales with the genus: Gleichenites, Cladophlebis, Sphenopteris, Pachypteris, Sagenopteris, Nilssoniopteris, Otozamites, Anomozamites, Zamites, Ctenozamites, Ptilophyllum and Desmiophyllum, a lower Cretaceous flora from the «Quebrada campanas and San Felix area in the Central Cordillera composed of Ferns, Bennettitales, Cycadales, Ginkgoales, Caytoniales and Coniferales with Coniopteris, Piazopteris, Klukia, Sphaenobaiera, Sagenopteris, Nilssoniopteris, Zamites, Podozamites, Cupressinocladus, Cyparissidium, and Elatocladus. These three floras are of euramerian type.     

Observations sur les GenresDermocarpa etDermocarpella (Cyanophyceae)

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