Impact d'une pollution urbaine sur la partie zooplanctonique d'un systeme neitique (Marseille - Cortiou)

Sewage of Marseilles' main outfall permanently pollutes a large coastal area centered around Cortiou, south of the city. In order to study the impact of that urban pollution on the zooplankton, more than 200 samples were collected between 1977 and 1981, according to several sampling strategies.Quantitatively, the study area showed a rather poor zooplankton. The more important populations were encountered near Cortiou, the non-perturbated reference point with lowest abundance of organisms. Sampling sites located near the outfall are sometimes azoic. Qualitatively, the observed communities are not characteristic of a heavily polluted environment, but correspond to an impoverished neritic community. In the more polluted area, the community is organized around the copepods Clausocalanus sp., Paracalanus sp. and Oithona helgolandica, and a group of less important species (Oithona nana and the cladoceran Evadne spinifera). Centropagidae, Coryceidae, Onceidae, but also Chaetognathians, Fritilliarins and the meroplanktonic larvae are more frequently encountered in clean water. Community structure is higher during the cold months than summer. The latter period frequently shows a disorganized zooplankton. In most situations, the copepod Acartia clausi plays a minor role in the structural definition of the communities.The variations observed seem largely independent of the parameters reflecting pollution intensity. Stress integration, in relation with the anterior community history (intensity of contact with polluted water, trophic potential of the area) seem to be the main regulator factors.

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Impact d'une pollution urbaine sur la partie zooplanctonique d'un systeme neitique (Marseille - Cortiou)

Resumé Le rejet permanent du grand émissaire de Marseille (5 m³, sec^–1) perturbe considérablement, par son importance, le système néritique du secteur de Cortiou. Afin d'approcher l'impact de cette pollution sur la partie zooplanctonique du système, plus de 200 prélèvements, concernant l'hydrologie et le plancton, ont of é\'t é réalises entre 1977 et 1981, selon différentes strategiés d'échantillonnage (suivi de masse d'eau, radiales, réseaux).Quantitativement on observe, sur l'ensemble de la zone étudiée, une abondance générale en zooplancton moyenne, voire faible. Les effectifs les plus importants se rencontrent cependant dans la cuvette de Cortiou, alors que le point de référence considéré comme non perturbé présente les effectifs les plus faibles. Les stations situées face à l'égout sont parfois azoïques.Qualitativement les peuplements ne paraissent pas trés caractéristiques d'un secteur pollué mais correspondent plutôt à un appauvrissement du peuplement néritique. Dans le secteur le plus pollué, la composition spécifique varie au cours du temps autour d'une communauté composée d'un groupe important avec Clausocalanus sp., Paracalanus sp., Oithona helgolandica et d'un groups de taxons moins fréquents représentés par des larves méroplanctoniques, Oithona nana et Evadne spinifera, tandis que les coryceidés, onceidés, Centropages typicus, chaetognathes et fritillaires se retrouvent plus fréquemment en eaux propres. La structure des populations est plus importante en période froide qu'en période chaude, période durant laquelle la communauté planctonique est fortement désorganisée. Paradoxalement Acartia clausi joue un rôle assez secondaire dans la définition structurelle de la communauté.Les fluctuations observées paraissent cependant peu liées à des paramètres reflétant l'intensité de la pollution. L'intégration du stress, en relation avec l'histoire antérieure de la communauté (intensité et durée du contact avec la nappe de dilution, potentialités trophiques) semblent ainsi prépondérantes.

     

Dinucleoside tetraphosphate variations in cultured tumor cells during their cell cycle and growth

Asynchronous and synchronized cultures of A549 and HTC cells were used to detect possible, cell cycle or cell density specific variations in the intracellular pools of dinucleoside tetraphosphates (Ap4X). No important variations of the nucleotide pools were observed during cell growth. When HTC cells were released from mitotic arrest, a decrease by a factor of N3 Ap4X and ATP levels was observed when the cells entered the G1 phase. This decrease is essentially due to cell doubling. When A549 cells were released from an arrest at the G1/S boundary, the nucleotide pool size increased slightly during the G2 phase just before mitosis. This result is in agreement with both earlier data from our laboratory and the observed decrease in Ap4X pool after release from mitotic-arrested HTC cells. These results suggest that the Ap4X and ATP pools are only subjected to very small variations during the cell cycle, essentially in the G2 phase and after mitosis.     

The diagnosis of short penis as a cause of impotentia coeundi in bulls

Short penis condition was diagnosed as the cause of impotentia coeundi in 10 bulls, aged 2.5 to 5 yr. The diagnosis was based on observation of service attempts, measurement of the extended penis, and elimination of other causes of impotence. Measurements of the penis were made under general inhalation anesthesia or pudendal nerve block. These measurements were then compared with those of 10 control bulls, matched for age and breed and having no history of impotence; the latter measurements were likewise obtained under general anesthesia, pudendal nerve block or sedation. with propionyl promazine. Similar measurements were obtained from 10 yearling bulls under propionyl promazine sedation. Measurements obtained under general anesthesia or pudendal nerve block in the same bull were usually similar and repeatable, while phenothiazine tranquillization produced incomplete and variable relaxation of the retractor penis muscles. The dimension best correlated with impotence due to short penis was the distance from the tip of the extended penis to the preputial orifice in its resting position. In 10 bulls in which short penis was diagnosed, this distance was 10 to 22 cm, while in 10 control bulls with no history of impotence it was 25 to 42 cm. The distances from the tip of the extended penis to the preputial reflection (fornix) and to the neck of the scrotum were also shorter in affected than in control bulls. Although observation of service ability remains the cornerstone of diagnosis of short penis, a presumptive diagnosis can be made if penile protrusion of less than 25 cm can be obtained in an adult bull under general anesthesia or pudendal nerve block. Phenothiazine tranquillization is suitable for screening examinations but not for definitive diagnosis.     

Expression of a Clostridium thermocellum endoglucanase gene in Lactobacillus plantarum

Recombinant plasmid pM25 containing the celE gene of Clostridium thermocellum, which codes for an enzymatically active endoglucanase, was transformed into Lactobacillus plantarum by electroporation. Strains harboring pM25 expressed thermostable endoglucanase, which was found predominantly in the culture medium. Two other plasmids, pGK12 and pSA3, were transformed into L. plantarum, and the stability of each plasmid was evaluated.     

Successive histochemical differentiation steps during postnatal development of the collecting duct in rabbit kidney

Immunohistochemical experiments with monoclonal antibodies (mabs) on the kidney of neonatal rabbits revealed that the primary expression of collecting duct typic structures does not occur in a continuous and parallel, but in a subsequent developmental process. Only mabs RCT-30 A, and CD 4-V revealed immunoreactivity at the ontogenetically oldest parts of the collecting duct, the ampullae, while the other used markers (CD 1-3, CD 5-V, RCT-30 and RMCX) did not. In contrast, all of the tested antibodies showed positive reactions at the medullary and cortical collecting duct of the neonatal kidney as well as of the adult kidney. Additional incubations with wheat-germ agglutinin (WGA) a marker of terminal-differentiated collecting duct cells demonstrated weak-labelled ampulla cells beside intensively labelled ampullary neck and medullary collecting duct cells. With peanut agglutinin (PNA) labelling a 3 step transition could be illuminated: weak-labelled ampulla cells were found beside continuously bright labelled ampullary neck cells and finally a punctuate pattern downwards to the papilla. If the ampullary neck is the zone of proliferation, our findings of WGA- and PNA-co-labelling in this zone indicate, that in early developmental stages characteristic structures of different mature cells, probably principal and intercalated cells, are co-expressed within one single cell type. Thus intercalated cells might derive from principal cells.     

Effects of serum type on growth and permeability properties of cultured endothelial cells

Serum is frequently added to defined basal media as a source of certain nutrients and macromolecular growth factors essential for cell growth. The many different sera commercially available may not be equally suitable for all cell types. The effects of four sera, fetal bovine serum (FBS), calf bovine serum (CS), equine serum (ES-1), and plasma-derived equine serum (ES-2), on growth and permeability properties of cultured porcine endothelial cells were determined. The rate of DNA synthesis, measured as [3H]thymidine incorporation, reached a peak at around 24 h, regardless of serum type, and was most marked with ES-1- or ES-2-treated cells. However, when estimated by total DNA, FBS, CS, or ES-1 treatment resulted in greater cell proliferation than ES-2. Based on protein synthetic rate and total cell protein, both FBS and CS appeared to be most growth supporting. At 72 h after cell plating, albumin passage across cultured endothelial monolayers was elevated in ES-1- and ES-2-treated cells compared with FBS- or CS-treated cells. "Leaky" cell monolayers were most marked with ES-1-treated cells. Cells grown in ES-2- and particularly in ES-1-enriched media were larger and more spindle-shaped compared with the typical cobblestone appearance of cells cultured in media enriched with either FBS or CS. These data suggest that CS, but not ES-1 or ES-2, is an excellent substitute for FBS to support desirable growth properties of macrovascular endothelial cells in culture.     

Interaction of the bisbiguanides chlorhexidine and alexidine with phospholipid vesicles: evidence for separate modes of action

Strains of Providencia stuartii with demonstrated resistance towards chlorhexidine did not show such resistance towards either of the related biguanide antiseptics, alexidine or vantocil. Alexidine promoted a significantly faster alteration in the permeability of Escherichia coli cell membranes towards various metal cations than chlorhexidine. Differential thermal analysis of various mixed lipid vesicles and pure phospholipid vesicles showed alexidine to share with vantocil the property of producing lipid phase separation and domain formation. It is suggested that the nature of the end-group on the biguanides affects the ability to produce lipid domains in cell membranes and this this might, in turn, affect activity and resistance patterns observed.     

Position effects on the timing of replication of chromosomally integrated simian virus 40 molecules in Chinese hamster cells.

Simian virus 40 (SV40) DNA molecules chromosomally integrated at different sites in three Chinese hamster lung fibroblast lines replicated during the middle portion of S phase but not precisely at the same time in all three cell lines. The time of replication was unrelated to the presence of T antigen or to its relative activity in promoting SV40 replication. SV40 sequences and chromosomal DNA sequences adjacent to the SV40 insert in one cell line expressing a temperature-sensitive T antigen showed a T-antigen-independent difference in replication timing from the homologous, allelic locus not linked to SV40. Our results indicate that the timing of replication of these integrated SV40 molecules is dependent upon the site of integration and is not determined by the level of T antigen replication-promoting activity.     

Actigraphy: A Means of Assessing Circadian Patterns in Human Activity

-Twenty-three diurnally active (0705-2333), healthy persons between 22 and 54 yrs of age and without history of sleep abnormality were monitored continuously for 120 consecutive hr (five days) by wrist actigraphy. Circadian rhythms of high amplitude were detected by cosinor analysis for each participant and for the groups of 10 males and 13 females with the average span of heightened activity timed between ∼1330 and 1605. The circadian peak-trough difference in wrist movement was marked, equalling aproximately 75% of the 24-hr mean level. In 19 of 23 participants, the 24-hr mean of wrist activity varied between 140-180 movements/min, with four persons exhibiting lesser means of 110-140 movements/min. With respect to the daytime span of activity, the mean wrist movement of individual participants ranged from 155-265 movements/min, with the majority (20/23) varying between 185-245 movements/min. During nocturnal sleep the mean wrist activity level was quite low, varying between individuals from 5 to 25 movements/min for 21 of 23 persons. Wrist actigraphy proved to be well-accepted and was a most reliable means of monitoring aspects of body movement during activity and sleep in ambulatory persons adhering to usual life habits and pursuits.