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J Templier

Publications and source records attributed to J Templier.

12 recordsLinked to original sources
PubMed2001

High molecular weight lipids from the trilaminar outer wall (TLS)-containing microalgae Chlorella emersonii, Scenedesmus conmmunis and Tetraedron minimum.

High molecular weight lipids were isolated from Chlorella emersonii, Scenedesmus communis and Tetraedron minimum, thin trilaminar outer wall (TLS)-containing freshwater microalgae producing an insoluble non-hydrolysable biopolymer (i.e. algaenan). Molecular weight determination by gel permeation chromatography indicated that their molecular weights range from ca. 400 to 2000 Da. Flash pyrolysis with in situ methylation using tetramethylammonium hydroxide (TMAH) and alkaline hydrolysis showed that the high molecular weight lipids isolated from C. emersonii and S. communis are mainly composed of saturated n-C26 and n-C28 fatty acids and alcohols and of saturated n-C30 and n-C32 alpha,omega-diols and omega-hydroxy acids. In contrast the high molecular weight lipids isolated from T. minimum are predominantly composed of long-chain fatty acids and omega-hydroxy acids. Aromatic moieties were also identified in small amounts in the thermochemolysate and in the hydrolysate. Chemical structural models containing long-chain mono- and polyesters were proposed for the high molecular weight lipids isolated from the three microalgae in agreement with analytical and spectroscopic data. Structural similarity between the outer cell wall of these microalgae and the cuticular membrane of higher plants is suggested.

Cell Wall↗
PubMed2000

Comparison of neutral lipid profile of various trilaminar outer cell wall (TLS)-containing microalgae with emphasis on algaenan occurrence.

The neutral lipid profiles of nine species of thin trilaminar outer wall (TLS)-containing freshwater and marine microalgae from the class of Chlorophyceae were studied with emphasis on the relationship between the lipid content and the occurrence of insoluble non-hydrolysable biopolymer (i.e. algaenan). All the freshwater microalgae produce a highly aliphatic algaenan. In sharp contrast, no algaenan was isolated from the two marine microalgae, Chlorella marina and Chlorella minutissima marina, supporting the absence of a close relationship between the presence of TLS and the occurrence of algaenan. High molecular weight straight-chain hydrocarbons (C23-C29) were identified in most of the algaenan-producing microalgae and in the algaenan-devoid C. minutissima marina, whereas only low molecular weight hydrocarbons were detected in algaenan-producing Scenedesmus subspicatus and in algaenan-devoid C. marina. Sterols, phytol and fatty alcohols were the major constituents of the polar fraction of the neutral lipids of all the microalgae investigated. High molecular weight saturated or mono-unsaturated alcohols were detected in C. emersonii and in all the microalgae belonging to the genus Scenedesmus. High amounts of saturated C30 and C32 alpha,omega-diols were also detected in S. subspicatus, S. armatus and S. pannonicus. Three classes of lipids were encountered in very small amounts in the medium polarity fraction of the neutral lipids of the microalgae investigated: (i) Monoesters composed predominantly of saturated C16 or C18 fatty acids and saturated C8, C16 or C18 alcohols and (ii) long-chain methyl ketones from C25 to C31 were detected in several species and (iii) methyl esters of fatty acids ranging from C16 to C28 were identified in all the microalgae. Attempts to use the neutral lipid composition and particularly the unusual long-chain lipids, as specific indicators of the occurrence of algaenan in TLS-containing microalgae were unsuccessful.

Alcohols↗
PubMed1988

Effects of microgravity and hypergravity on the cell: investigations on Paramecium tetraurelia.

Previous space CYTOS experiments have shown that space flights resulted in an increase in growth of Paramecia cultures. Microgravity is the major factor responsible of this response: indeed the stimulatory effect disappeared in inflight cultures placed on a 1 g centrifuge aboard the Spacelab. On the other hand, exposure to different levels of hypergravity on Earth resulted in an opposite response, i.e. to a reduced cell growth rate. A possible mechanism of microgravity on paramecia is discussed.

Animals↗
PubMed1986

Antibiotic activity in space.

Environmental factors in space exert an influence on the behaviour of bacteria, particularly on their sensitivity to antibiotics. Thus, G. Taylor and S. Zaloguev observed that bacterial samples collected on the crew during flight in the Apollo-Soyouz Test Project Mission presented higher antibiotic resistance than controls. This paper presents the results of two experiments performed in 1982 and 1985 (Cytos 2 during the French-Soviet Mission and "Antibio" in the Biorack programme of the European Space Agency). The results show an increase of antibiotic resistance in bacteria growth in flight and a modification in the structure of the cell wall. All these modifications are transitory. Two hypotheses are put forward to explain the phenomenon.

Anti-Bacterial Agents↗
PubMed1985

Respective role of microgravity and cosmic rays on Paramecium tetraurelia cultured aboard Salyut 6.

Paramecium tetraurelia cultured aboard Salyut 6 have shown in increase in cell growth rate, cell volume, water content and changes in electrolyte content. Additional experiments, carried out in balloon flight and on earth, showed that the stimulating effect observed on cell proliferation is related to exposure to cosmic rays. Other changes seem to be due to a direct effect of microgravity on cell. Mechanism of gravity action on cell is discussed.

Animals↗
PubMed1985

Study of minimal inhibitory concentration of antibiotics on bacteria cultivated in vitro in space (Cytos 2 experiment).

The aim of the Cytos 2 experiment, carried out during the French-Soviet manned flight in July 1982, was to study the bacteria's sensitivity to antibiotics cultivated in vitro during the orbital flight, using the bacterial method of minimal inhibitory concentration (MIC). Two species of bacteria were tested with various antibiotics: Staphylococcus aureus with Oxacillin, Chloramphenicol and Erythromycin; Escherichia coli with Colistin and Kanamycin. The results show an increase in resistance to antibiotics particularly strong in E. coli and weaker in Staphylococcus aureus. Considering these results, we think that there might be a relationship between the increase in resistance to antibiotics and a stimulating effect on growth rate by the factors of environmental space.

Anti-Bacterial Agents↗
PubMed1984

[Biological effects of weightlessness at the cellular level. Comparative study of cultures of Paramecia aboard the orbital station Salyut-6 and a stratospheric balloon].

In order to distinguish the effects of cosmic rays from those of weightlessness at the cellular level, we performed experiments aboard stratospheric balloon, where gravity is equal to 1 g and cosmic radiation roughly equal to that aboard Salyut-6. The results suggest that the stimulation of cell proliferation is probably due to cosmic rays, metabolic changes being related to microgravity.

Calcium↗
PubMed1981

[Study of the intra- and extracellular electrolyte content in Paramecia cultures carried out during a space flight (author's transl)].

In the results of previous investigations we have already reported that cultures of Paramecium tetraurelia submitted to a space flight present a stimulation of their proliferative ability, an increase in cell volume and a decrease in dry weight and in total protein content. These results suggest changes of cell metabolism induced by the space environment. In order to confirm this hypothesis we have studied the concentration of extracellular electrolytes in the control and the in-flight culture media with respect to the intracellular content of the same electrolytes. These measures concern Na, Cl, K, P, Mg, Ca. In this paper we report the results of these analyses and note that if no differences are noted for Na and Cl between control and in-flight cultures, modifications in P, K, Ca and Mg levels are observed. Generally there is a higher concentration of these elements in the in-flight medium but, in contrast, a lower intracellular content is noted for in-flight Paramecia. We have established a double comparison: on the one hand between control and in-flight media and between control and in flight cells, on the other hand between media and cells. All these data suggest possible changes in the membrane permeability, or of the binding proteins in Paramecia cultivated in hypogravity.

Animals↗
PubMed1981

[Effects of small doses of ionizing radiation on embryonic development of the mouse].

Mice with vaginal plugs were irradiated, seven hours after mating, i.e near fecundation, by 5, 10 and 25 rads of gamma rays from a 60Co source. Females were sacrificed on the 18th day of gestation. The total number of implantations was unchanged after exposure to 5 and 10 rads but the frequency of resorptions was increased for all doses. No abnormalities were observed in testicles, kidneys and skeleton.

Abnormalities, Radiation-Induced↗
PubMed1978

[Effects of small doses of gamma rays on gestation in mice].

Female mice were irradiated with 10 rads of 60Co gamma ray, 7 hours after mating. This low dose induces a decrease in implantation number, and alive foetus number and is followed by a lower number of corpora lutea. These results to seem to show an effect of gamma irradiation on ovary and embryonic development.

Animals↗