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J Gaillard

Publications and source records attributed to J Gaillard.

At least 73 records · Page 4Linked to original sources
PubMed1988

[Long-term survival of surgically treated lympho-epithelial thymomas].

The authors report the results of a multi-centre trial on 500 cases of lymph-epithelial thymoma (TLE) treated by 14 surgical teams. Most typically a tumour of the adult in the fifth decade, occurring most commonly in women (60%), one in every two cases of TLE occurs in auto-immune disease: usually myasthenia. Most often (3 times out of 4) the disease is latent and occupies the middle (40%) or superior mediastinum (30%). In 15% of cases the pulmonary radiograph is normal. Radical surgery is possible in 75% of cases, otherwise it is incomplete or even reduced to a simple biopsy. The 15 year prognosis obtained using actuarial survival curves is based on the surgical-anatomical classification of the study group of thymic tumours (GETT) giving: for stage I: a survival of 80% for stage II to IVA of 40% and for stages III to IVB of around 10%. Finally it should be noted that existence of a recurrence after a complete surgical excision (stage I) poses the problem of post-operative radiotherapy and the associated total thymectomy. Also, the identical prognosis after biopsy or incomplete surgery (IIIA and IIIB) with an increased morbidity for incomplete surgery. Finally the confirmation that pleural involvement (IVA) is not as adverse a factor as one would have supposed.

Adolescent↗
PubMed1987

Analysis of the high-spin states of the 2[4Fe-4Se]+ ferredoxin from Clostridium pasteurianum by Mössbauer spectroscopy.

A Mössbauer study of the three spin states of the reduced selenium-substituted 2[4Fe-4Se]+ ferredoxin from Clostridium pasteurianum was carried out at T = 1.6 K, in perpendicular and parallel applied magnetic fields of up to 10 T. In low (0.1 T) applied fields, the spectra of the classical S = 1/2 state exhibit magnetic hyperfine patterns arising from two pairs of iron atoms with opposite hyperfine fields. The S = 7/2 state is in the slow relaxation limit at T less than or equal to 4 K in the absence of applied field. The corresponding Mössbauer spectrum can be understood in terms of anti-parallel coupling between one high-spin Fe3+ ion (Hhf = +21.2 T) and three high-spin Fe2+ ions (Hhf,xy = -25.5 T, Hhf,z = -28.5 T). For the S = 3/2 spin state, the use of high (8-10 T) applied fields was necessary to ensure the validity of the high-field approximation and overcome the intercluster spin-spin interaction. The spectral data obtained under such conditions allowed the determination of the hyperfine field (-4.2 T) and a tentative estimation of the zero-field splitting (D approximately less than 3 cm-1).

Clostridium↗
PubMed1987

Structural requirements for the induction of "immunological castration" by linear monomeric LHRH-lys-MDP administered in saline.

It was previously shown that "castration" could be obtained in male mice by immunizing them in saline with a conjugate referred to as LHRH-Lys-MDP and containing the decapeptide hypothalamic hormone LHRH covalently linked to the adjuvant glycopeptide MDP-Lys. Since coupling was made using carbodiimide, it could have produced oligomers or isomers as well as monomers. In the present investigation male and female mice were immunized in saline with a linear monomeric MDP linked LHRH molecule obtained by total synthesis. Histological studies showed gonadal alterations in both male and female mice. The study of analogs provided a correlation between the "castrative" activity of LHRH-Lys-MDP and its chemical and antigenic structures. However, because LHRH antibody levels were not very high, mechanisms other than antibody response are discussed. Such totally synthesized molecules including a safe adjuvant could make a clinical use of LHRH immunization possible in endocrine-dependent cancers.

Acetylmuramyl-Alanyl-Isoglutamine↗
PubMed1987

Characterization of a cytosolic aconitase in higher plant cells.

Protoplasts obtained from sycamore (Acer pseudoplatanus) cell suspensions were found to be highly intact. If the protoplasts were taken up and expelled through a fine nylon mesh, all the protoplasts were ruptured leaving the fragile amyloplasts largely intact. Aconitase hydratase (citrate [isocitrate] hydro-lyase, EC 4.2.1.3) activity of sycamore cells was associated with two protein fractions, one present in the cytosol while the second is of mitochondrial origin. Chromatography on DEAE-trisacryl did not separate the aconitase hydratase isoenzymes. EPR studies established that both isoenzymes exhibited an EPR signal at g = 2.03 once oxidized.

Journal Article↗
PubMed1987

Immortalization of precursors of endodermal, neuroectodermal and mesodermal lineages, following the introduction of the simian virus (SV40) early region into F9 cells.

F9 embryonal carcinoma cells were transfected with a hybrid plasmid containing the early genes of the simian virus SV40 under the control of the adenovirus type 5 E1A promoter [21]. These cells were induced to differentiate in aggregates in the presence of retinoic acid (RA). Unlike the derivatives of F9 that are usually obtained in this manner, the plasmid-containing cells were both programmed and immortalized; in addition, expression of the SV40 T antigen was now triggered. These immortalized cells could be separated into three classes: (1) extraembryonic derivatives, (2) embryonic differentiated tissues, (3) immature cells surrounding the differentiated cells. When injected into mice, the mixture of these cells gave rise to multipotential tumors. From the immature cells, committed precursors of the neuroectodermal, endodermal, and mesodermal pathways could be isolated by cloning and selection according to: (a) their specific pattern of differentiation in the tumors and (b) the occurrence of specific markers in the differentiated progeny. The isolation of stable immortalized cell lines corresponding to precursors of the three primitive germ layers and capable of differentiating reproducibly along a particular restricted pathway should facilitate molecular studies on early embryonic development in mouse.

Animals↗
PubMed1987

Localization of H blood group antigen in ectoblastic derivatives of murine teratocarcinoma.

Ectoblastic derivatives (ectodermal and neuroectodermal components) constitute more than 90% of all structures in the murine teratocarcinoma derived from the PCC4-aza-1 line. This tumor was labeled immunocytochemically with fluoresceinated antibodies to A, B and H blood groups. A and B antigens were always noted to be absent from all structures of the three germ layers. With anti-H, however, embryonic and fetal endodermal components, e.g. alimentary or respiratory duct-like structures, gave positive staining. Mesodermal components, i.e. bone and cartilage structures, fibroblasts and myocytes of mature or embryonal type, were negative. Immature and mature ectodermal components, viz. epidermoid cysts or islets, were always positive. Neuroectodermal components, neuroblastic cysts and differentiated neuronal, glial and ependymal elements were always negative. Ectoblastic and/or neuroectoblastic individual cells or cell clusters, observed in the vicinity of positive differentiating ectodermal and neuroectodermal structures, were positive. Similar cells or clusters were negative when located close to negative neuroectodermal components. The undifferentiated, embryonal carcinoma cells and structures were always negative. These observations are compared to the staining patterns of H antigen in murine embryos and adult mice and in human teratocarcinomas. It is suggested that poorly differentiated, morphologically similar ectoblastic and/or neuroectoblastic structures are positive, if they concern ectodermal components, and negative, if they belong to neuroectodermal components, with the exception of some primary sensory cells that are positive. These last cells are also positive in normal fetal and adult tissues.

ABO Blood-Group System↗
PubMed1987

[Cimetidine treatment of primary hyperparathyroidism].

Since Sherwood's report in 1979, contradictory findings have been published with regarding the treatment of primary hyperparathyroidism with Cimetidine. We studied 16 patients with primary hyperparathyroidism treated with 1,200 mg of Cimetidine and followed-up clinically and biochemically. A decrease in serum calcium and urinary CAMP was observed after the fourth week of Cimetidine therapy with no significant change in parathormone levels. In none of the cases did Cimetidine seem to provide a treatment of hyperparathyroidism, a condition which remains curable with surgery.

Calcium↗
PubMed1986

Excretion of laccase by sycamore (Acer pseudoplatanus L.) cells. Effects of a copper deficiency.

Copper-deprived sycamore (Acer pseudoplatanus) cells do not excrete molecules of active laccase in their culture medium. In the range of 2-100 micrograms of copper initially present per litre of nutrient solution, the total laccase activity measured in the cell suspensions at the end of the exponential phase of growth was closely proportional to the amount of added copper. However, copper-deprived cells excreted the laccase apoprotein (laccase without copper) at the same rate as copper-supplied cells excreted the active, copper-containing, laccase. When the culture medium was initially supplied with limiting amounts of copper, the active laccase was excreted until all copper molecules were metabolized. Thereafter, the laccase apoprotein was excreted. Consequently, at the end of the exponential phase of growth, the cell supernatants contained a mixture of apoprotein and copper-containing laccase. After purification and concentration, this mixture of copper-containing laccase (blue) and laccase apoprotein (slightly yellow) showed a yellow-green colour. Under copper-limiting culture conditions an equivalent decrease of Type 1, Type 2 and Type 3 Cu2+ was observed. Addition of copper to copper-deficient enzyme solutions does not result in a recovery of the enzyme activity. However, when added to copper-deficient sycamore-cell suspensions, copper induced a recovery of the excretion of active enzyme, at a normal rate, within about 10 h. The first molecules of active laccase were excreted after 3-4 h.

Apoenzymes↗
PubMed1986

High-multiplicity spin states of 2[4Fe-4Se]+ clostridial ferredoxins.

The electron paramagnetic resonance (EPR) spectra of the reduced selenium-substituted 2-[4Fe-4Se]+ ferredoxins from three bacteria of the Clostridium genus display low-field signals at g = 5.17, g = 10.11, and g = 12.76. The positions, shapes, and temperature dependencies of these signals have allowed their assignments to the three excited states of an S = 7/2 spin multiplet, the fundamental state of which is observed as unusual features in low-temperature (T less than or equal to 20 K) Mössbauer spectra. The S = 7/2 spin state is present in 2[4Fe-4Se]+ clostridial ferredoxins together with the classical S = 1/2 state and with a S = 3/2 state, the fundamental doublet of which is observed as a broad signal in the g = 3-4 region. The relative intensities of the EPR signals corresponding to these spin states depend on the species of Clostridium that the ferredoxin is extracted from. In contrast with clostridial ferredoxins, the reduced selenium-substituted ferredoxin from Bacillus stearothermophilus, which differs significantly from the clostridial proteins by its primary structure and by its containing only one tetranuclear cluster, displays only the S = 1/2 state. Thus, the high-multiplicity spin states arise from a specific interaction between the clostridial ferredoxin polypeptide chain and the reduced [4Fe-4Se]+ clusters.

Clostridium↗
PubMed1986

Interaction between pyridine adenine dinucleotides and bovine liver catalase: a chromatographic and spectral study.

Two different fractions were present in crystalline bovine liver catalase, and could be resolved using dye-ligand affinity chromatography with Red-A Matrex gel containing Procion HE 3B. The major part (alpha) was not adsorbed on this gel. The second fraction (beta) was firmly adsorbed to the gel, and could be eluted either by high salt or by NADPH in the micromolar range. Elution of catalase beta was also obtained with NADH, NADP+, and ADP at higher concentration. Fractions alpha and beta displayed no detectable difference in specific activity, stability to heat, and light absorption data. It is suggested that the difference in behavior between alpha and beta is related to the binding of NADPH to the mammalian catalase [H. N. Kirkman and G. F. Gaetani (1984) Proc. Natl. Acad. Sci. USA 81, 4343-4347], and that the beta fraction corresponds to the enzyme molecules that have at least one free site for NADPH binding. Modifications of catalase molecules in the presence of dithioerythritol (DTE) were examined using light absorption and EPR data. Thiol induced changes that corresponded to the formation of catalase complex II. They were partially reversed by NADPH at very low level, and the dinucleotide appeared to be oxidized in this process. DTE-treated bovine catalase was totally adsorbed on the Red-A Matrex columns, and could be eluted as fraction beta. Similar spectral changes in the presence of DTE and NADPH were displayed by a bacterial catalase from Proteus mirabilis. This enzyme was also able to oxidize NADPH, but was not adsorbed by Red-A Matrex. This work suggests that dye-affinity chromatography provides a very convenient tool for isolating dinucleotide-depleted catalase from bovine liver, facilitating further study of the physiological function of this cofactor within the enzyme.

Adsorption↗
PubMed1986

Electron paramagnetic resonance characterization of membrane bound iron-sulfur clusters and aconitase in plant mitochondria.

Electron paramagnetic resonance (EPR) characteristics of the iron-sulfur clusters of potato tuber mitochondria have been examined in various subfractions of the mitochondria. We confirm that EPR signals comparable to those of the iron-sulfur proteins of mammalian mitochondria respiratory complexes are also present in plant mitochondria. Two distinct iron-sulfur centers paramagnetic in the oxidized state exhibit signals which differ in their detailed line shape and field position. One of these which is present in the inner membrane corresponds to center S.3. The EPR spectrum of the soluble fraction revealed the presence of another center with a low field maximum at g = 2.03 and is associated with aconitase. The EPR signal observed in the mitochondrial matrix from potato tuber and characteristic of 3Fe cluster is significantly changed in shape after addition of citrate and differs clearly from the spectrum of pig heart mitochondrial aconitase. The aconitase in plant mitochondria differs from that of mammalian mitochondria by several features.

Journal Article↗
PubMed1985

Immunological castration by a totally synthetic vaccine: modification of biological properties of LH-RH after conjugation to adjuvant-active muramyl peptide.

Recently, we demonstrated that immunological castration of male mice can be obtained by immunization with Luteinizing Hormone-Releasing Hormone (LH-RH) directly coupled to NAcMur-L-Ala-D-isoGln-L-Lys (MDP-Lys) without carrier and Freund's Complete Adjuvant (FCA) but in the presence of Polyvinyl-Pyrrolidone (PVP). In the present report, we have observed that: (a) immunization by the conjugate, LH-RH-MDP-Lys, was very effective even in absence of PVP, and this conjugate was more active than other conjugates containing MDP coupled to LH-RH fragments; (b) a strong secondary response could be observed by the administration of free LH-RH suggesting that the endogenous secretion of LH-RH might elicit a boosting effect; (c) administration of MDP-Lys coupled to LH-RH decreased the pyrogenicity of the glycopeptide; (d) such a conjugation also decreased the hormonal activity of the antigen although it enhanced its immunogenicity. These results show that a conjugate (2000 dalton) of a decapeptide hormone with a synthetic adjuvant glycopeptide can induce immunological castration in mice after administration in saline. The immunopharmacological properties of the conjugate and its conditions of efficacy suggest that such an approach could find clinical application.

Acetylmuramyl-Alanyl-Isoglutamine↗
PubMed1985

[Nosologic criteria for the classification of midfacial granulomatosis].

The authors report three cases of Stewart's disease and five cases of Wegener's disease seen over a period of 10 years, during which time they saw no cases of non-Hodgkins malignant lymphoma presenting as a mid-facial malignant granuloma. On the basis of these cases together with a review of the literature, they argue in favour of the dissociation of Stewart and Wegener as well as that of Stewart and monomorphous NHML, raising the problem of the existence of the latter as an entity.

Adolescent↗