Determinisme des anomalies de sex ratio á hérédité paternelle chez le crustacé amphipode Orchestia gammarellus Pallas

Summary

In the amphipod crustacea Orchestia gammarellus (heterogametic species: 2AXY male, 2AXX female), two kinds of sex ratio bias are recorded, hi the first category (thelygeny linked with intersexuality) a parasitic protozoa modifies the sexual phenotype of genetic males and can transform them into intersex males or functional females. This leads to the occurrence of viable 2AYY males and females.

In a second kind of sex ratio bias, males cause hereditary shifts of sex ratio. These ‘paternal sex ratio’ (psr) traits are transmitted by the male at each generation. Psr-f males cause an excess of females, psr-m males an excess of males.

The psr-m trait has a strictly patroclinous mode of transmission, but females from psr-f strains intervene in the expression of psr-f trait. Intra-sib matings are characterized by an excess of males. This characteristic seems to be linked with the age of the female. It disappears during successive brood. A relation between the psr-m and psr-f trait is observed: some psr- m males give psr-f males in the their progeny.

The analysis of crosses between psr-f or psr-m males and YY females allows to discard meiotic drive or sex lethal mortality as causes for the psr traits. Our results are best explained if we suppose that psr-f and psr-m males are XX and that extrachromosomal hereditary factors or transposable genetic elements intervene in the determinism of the psr traits: a psr-m factor able to masculinize all the embryos and a psr-f factor able to masculinize embryos if present in a sufficient amount.     

Altérations cytologiques induites par la zéaralénone chez Bacillus thuringiensis (Berliner)

Zearalenone (F-2 toxin) an estrogenic mycotoxin secreted by some species ofFusarium exhibits an antibacterial activity which can be easily demonstrated in Gram-positive spore forming bacteria, especially inBacillus sp.Morphologically abnormal cells were produced byBacillus thuringiensis (Berliner) in response to zearalenone. The most significant ultrastructural alterations obtained with the mycotoxin at 2.5 or 5.0 g/ml, are: increase of number of mesosomes which are hypertrophied, decrease of ribosomes, formation of imperfect cell septa and unknown crystalloid inclusion.These effects which provoke induction of atypical long cells, resemble those obtained with one other mycotoxin which possesses as zearalenone an unsaturated lactone structure: aflatoxin B₁.     

Éjaculation provoquée par le vibromassage ou l’électrostimulation endorectale chez le blessé médullaire: injection intracytoplasmique de spermatozoïdes obtenus par stimulation endorectale chez neuf couples

800 to 1,000 cases of traumatic spinal cord injury (S.C.I.) are observed in France each year. At present time, there are more than 35,000 survivors of S.C.I. in France. Studies show that 80% of injuries occur in men and 82% occur in individuals between the ages of 16 and 45 years. It is well known that more than 80% of men with S.C.I. suffer from ejaculation dysfunction. Since most of these couples are young, many desire a family and seek help to remedy their infertility. Two methods are mainly used to retrieve sperm from S.C.I. men: penile vibratory stimulation and rectal electrostimulation. Penile vibratory stimulation to induce ejaculation is recommended as first-line treatment, and S.C.I. men should only be referred for electroejaculation after failure of this technique. More than 70% of patients respond to penile vibratory stimulation with anterograde ejaculation. Patients who fail to ejaculate by penile vibratory stimulation are treated by electroejaculation. Their ejaculates often have normal sperm counts, but with a higher proportion of immotile sperm than in men without S.C.I. The authors report the pregnancy outcome of a series of 9 couples undergoing combined electroejaculation and in vitro fertilization with intracytoplasmic sperm injection: 25% pregnancies per cycle and 33% pregnancies per couple.     

Evolution de la capacité morphogénétique de la région stomodéale chez l'embryon dePleurodeles waltlii Michah (amphibien urodéle). etude par transplantation intrablastocélienne et par culture in vitro

Summary Transplantations into the blastocoel of gastrulae and cultures in vitro of the stomodeal region ofPleurodeles waltlii Michah embryos have been carried out. These experiments gave the following results:Neural crest cells reach the stomodeal region at the young tail-bud stage (stage 22), and are able to take part in formation of teeth and cartilage, it is possible to dissociate the phenomena of mouth opening, complete mouth formation and complete head formation, differentiation of a digestive tube from the pharyngeal endoderm and the formation of a mouth opening both depend on the presence of mesentoderm and mesectoderm in the explant or in the environment, during the tail-bud stage a symmetry factor plays a part in mouth formation, bone formation likewise coincides with the presence of neural crest cells.

     

Connaître les particularités du traitement par antivitamine K chez le patient âgé ou comment minimiser leur iatrogénie ?

Elderly patients are commonly frail, due to a lot of comorbid conditions and numerous medications. These patients are at high risk of bleeding when treated with vitamin K antagonist (VKA). Special considerations on the choice of VKA drug, dosing and monitoring have to be taken into account in the elderly in order to avoid over-anticoagulation and to minimize the haemorrhagic risk which consequences may be dramatic or fatal in this age group. In these patients, INR monitoring is crucial, especially at the start of treatment. The use of dosing algorithms specifically developed for elderly patients allows to decrease over-anticoagulation during the initiation period. INR has to be monitored more frequently in case of acute illness or in case of modification of the associated drugs. Patient education is of great importance, even in geriatric patients and has been shown to improve the quality of anticoagulation. New oral anticoagulants with a wider therapeutic index seem to be of great interest.     

Analyse des caryotypes métaphasiques méiotiques chez le mâle dePleurodeles waltlii (Amphibien,Urodèle) après coloration des chromosomes par l'argent ammoniacal

Analysis of metaphasic meiotic karyotypes in male of Pleurode les waltlii(Amphibia, Urodela) after silver ammoniacal staining of chromosomes. In the newtPleurodeles waltlii, the ammoniacal silver staining technique was applied to the male meiotic chromosomes at metaphase I and II. A specific staining of paracentromeric heterochromatin and of the centromere is observed on each chromosome of the complements. The two karyotypes are analysed and the homology between meiotic and mitotic chromosomes is established.

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Analyse des caryotypes métaphasiques méiotiques chez le male dePleurodeles waltlii (Amphibien, Urodèle) après coloration des chromosomes par l'argent ammoniacal

     

Sur les différents types de mutations extranucléaires induites par le méthane sulfonate d'éthyle chez nicotiana tabacum L.

• 1.(1) The treatment of seeds of Nicotiana tabacum L. by an ethyl methanesulfonate solution induced variegations with different chlorophyll deficiencies. These mutations are maternally transmitted.
• 2.(2) The pattern of somatic segregation which is maintained through the three observed sexual generations may be specific from one type of mutant to the other.
• 3.(3) The occurrence of heteroplastidic cells in the intermediate tissues was observed i in two offsprings (5.061 and 7.024). The chloroplasts degenerate in these two cases during the leaf maturation. In a third case, the normal and deficient tissues are always clearly defined; here we have not observed heteroplastidic cells; moreover, histologically the deficient tissues differ from the normal ones; structure formation in the plastid mutants is only delayed with respect to the normal ones.
• 4.(4) Frequent cases of reversal from the mutant state to normal can be observed in the newly formed sectors which are purified later in leaf ontogenesis.
• 5.(5) Finally, we can assume as a working hypothesis that the factors responsible for the hereditary transmission are the plastids themselves. However, it is necessary to suppose that some interactions exist between the different organelles of the protoplasm (nucleus, plastids and mitochondria), which involve particular models of somatic behaviour for each kind of alteration.
• 6.(6) Ethyl methanesulfonate, with its very large spectrum of effects, allows the investigation of various possibilities for extranuclear types of mutation.

     

L'action de l'air ionisé dans le traitement des ulcères gastroduodénaux (Données expérimentales chez le rat et essais cliniques)

Résumé Par un jeûne de trois jours ou par l'administration per os de réserpine(2 à 4 mg/kg) durant 15 à 24 jours, on a provoqué des ulcères d'estomac chez des rats. Une partie des bÊtes ainsi traitées fut exposée durant cette période et pendant 2 heures par jour à un air ionisé contenant 5.000 à 15.000 petits ions par cm³ d'air. Pour les animaux soumis au jeûne, la proportion d'ulcères se monte à 93% chez les bÊtes de contrÔle, alors qu'elle n'est que de 59% chez les bÊtes traÎtées par l'air ionisé. Pour les rats traÎtés à la réserpine, les proportions sont de 83,respectivement de 45%. On a en outre exposé 66 patients atteints d'ulcères d'estomac et d'intestins durant 12 à 15 jours et pendant 15 à 45 minutes par jour à un air contenant 5.000 à 10.000 petits ions négatifs par cm³ d'air. Pour 38 d'entre eux, la douleur et les autres symptÔmes avaient diminué ou disparu après le traitement.

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Gastric ulcers were produced in rats by starvation for 3 days or the administration of reserpine (2 to 4 mg/kg) for 15 to 24 days. Some of the animals were exposed to ionized air for 2 hours daily during these periods(5,000 to 15,000 small negative ions/m3 air). The incidence of ulcer development was 93% in the untreated starved rats and 59% in those treated with ionized air; 83% in the animals treated with reserpine and 45% in those with additional ionized air treatment. In a clinical investigation 66 patients with peptic ulcer were exposed for 12 to 15 days to 5,000 to 10,000 small negative ions/m³ air daily. Pain and other symptoms were diminished or abolished after this treatment in 38 patients.

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Zusammenfassung Bei Ratten wurden durch 3 Tage Hungern oder Behandlung mit Reserpin (2–4 mg/kg) wÄhrend 15 bis 24 Tagen Magenulcera provoziert. Ein Teil der Tiere wurde wÄhrend dieser Perioden 2 Std. tÄglich ionisierter Luft exponiert (5.000–15.000 kleine Ionen/m3 Luft). Die Ulcusrate betrug bei den unbehandelten Hungertieren 93%, bei den mit ionisierter Luft behandelten 59%; bei den Reserpin behandelten Tieren betrug sie 83% und bei den zusÄtzlich mit ionisierter Luft behandelten 45%. In der Klinik wurden 66 Patienten mit Magen-Darmulcera 12–15 Tage lang 15–45 min tÄglich mit 5.000 –10.000 neg. kleinen Ionen/m3 Luft behandelt. In 38 Patienten waren nach der Behandlung der Schmerz und die anderen Symptome abgeschwÄcht oder verschwunden.

     

Polymorphisme électrophorétique des protéines et enzymes sériques et érythrocytaires chez le chimpanzé (Pan troglodytes)

Summary The electrophoretic mobilities of serum enzymes and other proteins were investigated at 35 loci in 25 unrelated individuals of the chimpanzee Pan troglodytes. In this population the mean average of individual polymorphism is =0181, and the average level of heterozygoty =0.022. The same pattern of individual variability is found in Pan troglodytes and Homo sapiens.