Metabolisme du γ-aminobutyrate chez Agaricus bisporus Lge.

Summary Transamination between -aminobutyrate and -ketoglutarate provides a pathway for the utilization of -aminobutyrate in fruit-bodies of Agaricus bisporus Lge. This reaction leads to the formation of succinic semialdehyde, a metabolic intermediate in the metabolism of -aminobutyrate to succinate in the cell. -aminobutyrate: -ketoglutarate aminotransferase (E.C. 2.6.1.19) was sonically extracted from the mitochondrial fraction and partially purified by DEAE-cellulose column chromatography. Aminotransferase had a pH optimum between 8.1 and 8.5 and did not require pyridoxal-phosphate in vitro; however, the enzyme was inhibited by carbonyl-trapping reagents such as pyridoxal-phosphate activated enzymes. The Km values for -aminobutyrate and -ketoglutarate calculated from Lineweaver-Burk plots were 2.2×10^-4 M and 2.5×10^-3 M, respectively. The transaminase was specific for -ketoglutarate but not for -aminobutyrate; aspartate, -alanine and -aminovalerianate also functioned as amino-group donors. Activity of the enzyme was not influenced by the addition of carboxylic acids of the Krebs cycle. The reversal of the transamination reaction showed optimal rates at pH 9.0–9.3. Some considerations on the physiological significance of these results are given.

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Abréviations DEAE diéthylaminoéthyl - EDTA éthylène diamine tétraacétate - DCIP 2,6-dichlorophénol-indophénol - GABA acide -aminobutyrique - GABA-T -aminobutyrate: -cétoglutarate aminotransférase - GAD L-glutamate décarboxylase - Glu acide glutamique - -KG -cétoglutarate - MBTH 3-méthyl-2-benzothiazolinone hydrazone - PLP pyridoxal-5-phosphate - PMS phénazine méthosulfate - SSA acide semialdéhyde succinique - TCA acide trichloracétique - Tris 2-amino-2-(hydroxyméthyl)-1,3-propanediol     

Evolution du risque infectieux chez l'enfant atteint de leucémie.

Infection is the leading cause of illness and death in children with leukemia. The risk of infection may change over time as regimens of therapy are modified. A review of the hospital charts of 166 infants in whom leukemia had been diagnosed between 1976 and 1980 revealed an increased number of deep fungal infections (20 v. 3) during this period in comparison with the number between 1969 and 1976 in 164 patients treated at the same hospital whose leukemia was diagnosed between 1969 and 1975. The 20 severe fungal infections between 1976 and 1980 were characterized by difficulty of diagnosis (a definite diagnosis having been made three times out of four only at autopsy), an important role of Candida but also of Aspergillus (the latter having been isolated almost as often as the former) and a grave prognosis (the mortality being very high [75%] and much above that for gram-positive septicemia [6%] and that for gram-negative septicemia [31%]). This increase in frequency of fungal infections was concurrent with the introduction of phase-1 chemotherapy, which was often responsible for prolonged neutropenia. To reduce the risk of infection in children with leukemia it appears to be essential to improve diagnostic methods and approaches to therapy.     

Les rythmes endogènes des mouvements foliaires chez Mimosa pudica L.

Abstract

Endogenous Rhythms in Mimosa pudica L. Leaf Movements.

The rhythmic movements performed by the leaves of the “Sensitive plant”, Mimosa pudica L., observed by time lapse photography, result of periodical turgor variations taking place in the parenchymatous cells of specialized motor organs. These turgor variations are associated with membrane permeability changes and ionic movements. These leaf movements allow to specify the temporal organization of this plant. Statistical analysis of observed periodicities in leaf movement shows that, in alternating conditions of light and dark (L/D:14/10) three distinct rhythms exist: a circadian rhythm synchronized by the photoperiodic cycle (τ = 24 hrs), and two ultradian rhythms with mean period values 3.8 hrs and 0.5 hrs respectively. In constant conditions from germination (L/L), the leaf behavior is strongly modified, but the three period values are found again (mean period values of 25.1 hrs, 3.5 hrs and 0.6 hrs respectively). The occurence of many rhythms with various periods taking place in the same organ is discussed in reference to observations effected on other biological subjects. Then, it appears that the period value within 2 and 4 hrs may be considered as a characteristic one in plants.     

Variabilité morphologique,caryologique et enzymatique chez quelques populations dePhragmites australis (Cav.)Trin. exSteud.

Use of morphological, karyological and enzymatic approaches in the study of 11 populations ofPhragmites australis (Cav.) Trin. exSteud. originating from different geographic areas, climates and ecological conditions reveals a spatial differentiation of populations. There is no relationship between the two levels of ploidy, 2n=48 and 2n=96, and the habitat. In contrast, the climate and environmental conditions act to the selection of the well-adapted genotypes. So, the considerable phenotypic variability ofP. australis is due to a high adaptability and an important genetic diversity.     

Irradiations à faible énergie et biosynthèse d'amarantine chez des plantules d'Amarantus tricolor L. var. bicolor ruber Hort.

Summary It has been shown that indoleacetic acid (IAA) does not occur in developing grains of Hordeum vulgare L. (barley), but that an unidentified indolic compound does. This compound, designated A, was also found to be a product of the metabolism of exogenous IAA by barley. The expression of the gibberellic acid effect was delayed for at least 8 h if grains were imbibed in a solution of IAA, and during this time, the IAA was metabolised. The enzyme system involved could be peroxidase, which was active in the grains at all stages of their development and at maturity, and partially purified extracts of peroxidase were found to have considerable IAA oxidase activity.Abbreviations DMABA dimethyl aminobenzaldehyde - dMACA Dimethyl amino cinnamylaldehyde - GA gibberellic acid - IAA indole acetic acid     

Tétraploïdie expérimentale chez le Triton Pleurodeles waltlii Michah.

Fischberg's method, thanks to which tetraploid individuals can be obtained, has been adapted to the newt Pleurodeles waltlii. — If at the beginning of the first furrow formation, the eggs are submitted for 10 minutes to a sudden increase in temperature (37.2–37.3°C), the embryos that subsequently develop are tetraploid in 100% of the cases. The percentage obtained of viable individuals is about 30% of the number of heated eggs. — A temperature treatment between 36.2 and 36.4°C applied at the same period and for the same length of time may lead to the formation of viable animals diplo-tetraploid mosaic. — Among adult tetraploids or diplo-tetraploid mosaic males and females can be found. — The cells of tetraploids can easily be distinguished from those of diploids by their larger size. Therefore, the former can be used as cellular markers.     

Asynchronisme cardiaque chez le sujet à QRS fin. Étude par échocardiographie Doppler tissulaire

ObjectiveTo assess the prevalence of different types of cardiac dyssynchrony by pulsed Doppler ultrasound and Doppler tissue in patients with narrow QRS with or without left ventricular systolic dysfunction.MethodologyProspective, cross-sectional survey at the Institute of Cardiology of Abidjan, from January to April 2012, in subjects with narrow QRS. Group 1: patients with dilated cardiomyopathy with severe left ventricular dysfunction (left ventricular end diastolic diameter greater than 60 mm and/or 30 mm/m² and ejection fraction less than 35% NYHA stage IV). Group 2: normal subjects with normal echocardiography. All patients underwent an evaluation including tissue Doppler search for different types of dyssynchrony (atrioventricular, interventricular and left intraventricular).ResultsPatients in group 1 were significantly older (51.5 ± 15.8 vs. 35.8 ± 7.8, P = 0.03), with larger left ventricular diameters and significantly higher pulmonary systolic pressure. The prevalence of different types of dyssynchrony in group 1 were: atrioventricular dyssynchrony 43.7%, interventricular dyssynchrony 37.5%, left ventricular dyssynchrony 65.6%. Group 2: atrioventricular dyssynchrony 0%, interventricular dyssynchrony 0%, left ventricular dyssynchrony 35%.ConclusionA large proportion of patients with left ventricular systolic dysfunction and narrow QRS have cardiac dyssynchrony and left ventricular dyssynchrony can be found in healthy patients. This raises the problem of the specificity of Doppler ultrasound criteria using cardiac tissue Doppler to assess cardiac dyssynchrony.     

Etude cytochimique de la spermatogenèse chez Lithobius forficatus L. (Myriapode Chilopode)

Résumé L'étude cytochimique de la spermatogenèse a été envisagée, d'un point de vue qualitatif chez Lithobius forficatus L. (Myriapode Chilopode). Les cellules de la lignée mâle sont de nature essentiellement protéique. On peut distinguer trois grandes périodes: 1. la croissance spermatocytaire, caractérisée par la synthèse d'ARN et de protéines basiques, 2. les phases de division de maturation, 3. la spermiogenèse, marquée par la diminution progressive de la teneur en ARN et en histones.

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Cytochemical study of spermatogenesis in Lithobius forficatus L. (Myriapoda Chilopoda)

Summary A qualitative cytochemical study was carried out of Spermatogenesis in Lithobius forficatus L. (Myriapoda Chilopoda). The gametes are characterized by their protein nature. Spermatogenesis can be divided into three major periods: 1. Spermatocyte growth, a phase of synthesis of RNA and basic proteins, 2. period of maturation divisions, 3. spermiogenesis, characterized by a gradual decrease in the amounts of RNA and histone.

     

Incorporation de glycine-3H chez les glandes pétiolaires de Mercurialis annua L.

Summary Isolated young leaves of Mercurialis annua L. are successively fed with solutions of tritiated glycine and cold glycine. A radioautographic study of the cells of the petiolary glands shows sites of synthesis and translocation of proteins. Synthesis takes place in mitochondria, plastids, nucleus and ergastoplasm, including a very important part of the latter which contains big inclusions partly formed from proteins. Then, while mitochondria, plastids and nucleus remain radioactive, the newly formed proteins of the ergastoplasm successively pass to golgi bodies and smooth endoplasmic reticulum, to membranous whorls (myelin figures) and finally to external secretions. Since we know that golgi bodies contain polysaccharides, a role of these organelles might be to bind the newly formed proteins to these polysaccharides.

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Ce travail fait partie d'une thèse de doctorat d'Etat sur la cyto-physiologie des nectaires.     

Le syndrome douloureux chronique pelvien chez l’homme. Quelle physiopathologie? Quel traitement?

Chronic pelvic pain, in young men or elderly men, has always been a challenge to the medical profession, raising problems of assessment and management. Chronic pelvic pain has a high prevalence, which is underestimated as indicated by the following figures: 4% to 8% of patients consulting chronic pain centres, 15% of patients consulting a urologist for symptoms of chronic prostatitis with alteration of quality of life, 70,000 cases of chronic cystitis per year in the USA. The circumstances of onset are multiple: postoperative, after minor or major trauma or postinfectious, sometimes without any particular aetiology and often in a multifactorial context. The pathophysiology is therefore vague and poorly elucidated, as only about 5% of cases of chronic prostatitis have a bacterial cause. However, any form of stimulation activates pain pathways with neurogenic inflammation followed by central sensitization and modification of neuronal plasticity, and finally chronic refractory pain with organic dysfunction. This mechanism is currently proposed in numerous publications concerning postoperative chronic pelvic pain and refractory cystitis and chronic prostatitis. The pathophysiology of these types of pain is probably therefore neurogenic. In the absence of stimulation, a pudendal nerve tunnel syndrome can be suggested. The treatment of chronic pelvic pain in men can be considered in the following way: aetiological treatment whenever possible, neurogenic medical treatment (tricyclic antidepressants for continuous pain, anticonvulsants for intermittent pain, NMDA receptor antagonists in the case of failure), treatment of organic dysfunction, pudendal nerve analgesic block in the case of suspected tunnel syndrome and global treatment of patient with impaired quality of life. In conclusion, a better pathophysiological approach to these forms of chronic pelvic pain can improve these difficult patients.     

Régénération des boutures d’apex de rhizomorphes chez lesphaerostilbe repens B. et Br.

The tips of the rhizomorphs ofSphaerostilbe repens transferred on agar medium regenerate some aggregated organs without an intermediate mycelium stage. Each extremity of the drawn rhizomorphs can give rise to eoremia on its air face and to rhizomorphs on the contact with tho culture medium. These heterogeneous environmental factors impose polarized regeneration, easily inverted, upon the rhizomorphs. Nevertheless, a residual and stable polarity remains; it is attributed to the apex which is more capable of bearing new organs than the other extremity. Tho efficiency to regenerate depends on the ago of collulos and on tho size of tho rhizomorph tip; howover it is very difficult to provent the formation of new aggregated organs.     

Essai d'analyse de la dynamique ovarienne chez les guêpes polistes (P. gallicus L. etP. Nimpha christ) en activité reproductrice

Conclusions Cette étude du fonctionnement ovarien nous a notamment permis d'évaluer quantitativement les principales variables du phénomène, ce qui était, dans notre programme de travail, à résoudre en première urgence.Nous avons montré l'importance de l'ovosorption dont nous connaissions l'existence sans pouvoir lui attribuer une valeur quantitative.Nous noterons une différence avec le Dytique: la dégénérescence peut frapper les ufs mûrs.D'un point de vue plus général, nous mettons en évidence dans une même fonction, la dualité des caractères entre les phénomènes de comportement marqués par leur grande variabilité et leur discontinuité, et les phénomènes physiologiques qui expriment sans rupture l'action des facteurs externes.Le fait qu'une certaine proportion des ufs produits puisse ne pas être pondue, permet d'expliquer la diminution ou l'augmentationbrusque de la ponte sous l'action de stimulations d'origine sociale, dues soit à l'évolution normale du nid (cellules libres, couvain, etc.), soit, plus fréquemment dans nos conditions d'expérience, à l'effet de groupe.

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Summary Ovarian function inPolistes is governed by three fundamental parameters:the delivery rate of the ovaries, the duration of oocyte development, andthe rythm of egg-laying. The first two, which act directly upon the ovaries (particularly the number of developing oocytes), are immediately influenced by the physical environment, especially the temperature. The third, on the other hand, is under behavioral control.It is emphasized that the late parameter rarely attains its maximum value: the female does not lay all her eggs, eliminating a variable proportion by ovosorption.

     

Analyse de la transmission des chromosomes surnuméraires chez Locusta migratoria migratorioides R. et F. (Orthoptera,Acrididae)

In a African grasshopper population of Locusta migratoria migratorioides reared in the laboratory, B chromosome transmission is analysed in progeny of pairs taken at random from the population. An accumulation mechanism of Bs exists in the females which presumably results from preferentiel segregation of the Bs in the female pronucleus. The analysis also shows B chromosome elimination during embryonic and larval development by means of mitotic non-disjunction: these non-disjunctions induce interfollicular variations in the number of Bs but all the cells of a follicle have the same number of Bs. The frequency of animals with B chromosome rises from 34% to 75% as the diurnal temperature rises from 27° C to 35° C. Thus frequency is controlled by genetic and environmental factors.     

Alcaloïdes chez les capparidaceae

Alkaloids were isolated from leaves of 33 of 36 species and l-stachydrine and l-3-hydroxystachydrine were the major components present. These alkaloids characterize the family Capparidaceae in the same way as do the glucosinolates.     

Les ultrastructures liées aux fonctions de relation chez Noctiluca miliaris S. (Dinoflagellata)

Résumé L'étude ultrastructurale de Noctiluca miliaris révèle dans le tentacule du Trophozoïte l'existence de bandelettes fibrillaires striées transversalement; elles sont insérées radialement au niveau d'une couche de microtubules périphériques longitudinaux. La striation principale S a une période de 0,2 et les stries secondaires s une période de 0,1 ; ces périodes peuvent varier légèrement. L'étude du plissement et des mouvements tentaculaires révèle le rôle important joué par les bandelettes striées et les microtubules périphériques.L'observation du complexe buccal met en évidence un cystotome et un cône buccal à paroi complexe, armé de trichocystes fibreux et muqueux. Au niveau interne de la paroi, est inséré un rideau de longs faisceaux de fibres striées, relié au sillon postérieur. La période de striation transversale de ces fibres varie de 0,1 à 0,3 . Leur contractilité ne fait aucun doute.Dans les sporocytes, ces diverses formations n'existent pas; l'appareil flagellaire est composé d'un flagelle unique de structure classique, mais dont le fouet est garni d'un cordon spiralé.L'étude de ces divers éléments a permis d'effectuer des comparaisons entre Noctiluca, d'autres Dinoflagellés et d'autres Protistes, affirmant ainsi l'originalité des Noctilucinae.

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The ultrastructures linked to the nutrition and the movements in Noctiluca miliaris S. (Dinoflagellata)

Summary The ultrastructural investigation of Noctiluca miliaris reveals in the tentacle of the vegetative individual the existence of narrow fibrillar bands transversely striated: they are radially inserted at the level of a layer of longitudinal peripheral microtubules. The main striation S has a period of 0,2 and the secondary stria s a period of 0,1 . These periods may slightly vary. The study of the folding and of the tentacular motions reveals the important role played by the striated narrow bands and the peripheral microtubules.The observation of the buccal complex shows a cytostome and a buccal cone with a complex wall, provided with fibrous and mucous trichocysts. At the internal level of the wall is inserted a screen of long bundles of striated fibres, linked to the posterior furrow. The period of these fibres varies from 0,1 to 0,3 . They are certainly contractile.In the sporocytes, these formations do not exist. The flagellar apparatus is composed of a single flagella of classical structure, but its whip is provided with a helical cord.The study of these different elements allows one to make comparisons between Noctiluca, other Dinoflagellates and other Protozoans affirming the uniqueness of the Noctilucinae.

Cet article fait partie d'une Thèse de Doctorat d'Etat, intitulée: La cytologie et la division de deux types de Dinoflagellés: Noctiluca Suriray (genre libre) et Blastodinium Chatton (genre parasite).     

L'Inhibine B chez les blessés radiculo-médullaires. Résultats préliminaires

Spinal cord injuries in adult men sometimes results in semen alteration and in ejaculation missing. Testicular biopsies showed spinal cord injury is bound with testicular and germinal cells alterations. An endocrine profile for thirteen patients without semen at the time of the study is performed: total testosterone, bioavailable testosterone, FSH and inhibin B. Compared with seven normal controls, subjects with spinal cord injury had a significantly lower value of total testosterone, bioavailable testosterone and inhibin B. The FSH values higher in spinal cord injury are not significative. These results allowed to expect inhibin B like a good marker of testicular function and spermatogenesis. A longitudinal and on more subjects will answer to this question.