Biomedical subjects

P Berthon

Publications and source records attributed to P Berthon.

At least 55 records · Page 3Linked to original sources

PubMed1996

Ruminant cluster CD14.

Following the analysis of flow cytometry data on ovine and bovine cells and immunoprecipitation, immunohistochemistry and competitive binding studies, a cluster of three monoclonal antibodies (mAbs) (VPM65, VPM66 and VPM67) appeared to be specific for the ruminant CD14 (Gupta, V.K., McConnell, I., Dalziel, R.G. and Hopkins, J., 1996. Identification of the sheep homologue of the monocyte cell surface molecule-CD14. Vet. Immunol. Immunopathol. in press; Hopkins, J. and Gupta, V.K., 1996. Characterization of 3rd Worshop monoclonal antibodies specific for sheep macrophages/monocytes. Vet. Immunol. Immunopathol., 52:329-339). According to flow cytometry results from human CD14-transfected COS-7 cells and from bovine peripheral blood mononuclear cells, another mAb (CC-G33), not submitted to the Workshop, recognised a bovine CD14 epitope which is conserved in the human CD14 (Sopp, P., Kwong, L.S. and Howard, C.J., 1996. Identification of bovine CD14. Vet. Immunol. Immunopathol., 52: 323-328).

Animals↗

PubMed1996

Immunohistochemical study on the reactivity of workshop monoclonal antibodies with sheep lymph nodes.

Of the 302 monoclonal antibodies submitted to the Third Workshop on Ruminant Leukocyte Antigens, 167 have been tested for their reactivity on sheep lymph node sections, according to the APAAP immunohistochemical technique. Of the 57 monoclonal antibodies able to react on ovine tissue sections, only 37 induced a clear and well-contrasted staining. The more striking results are presented in this paper.

Animals↗

PubMed1996

Flow cytometric analysis of the reactivity of workshop monoclonal antibodies on sheep lymph node cells, after infection with Salmonella abortusovis.

Of the 302 monoclonal antibodies included in the Third Workshop on Ruminant Leukocyte Antigens, 167 have been tested for their reactivity on uninfected and Salmonella-infected sheep lymph node leukocytes using FACS analysis. Only 47 of them showed specificities which could be related to those of some control monoclonal antibodies, such as the anti-CD5, anti-Ig light chain and anti-MHC Class II monoclonal antibodies.

Animals↗

PubMed1996

Mitochondrial biogenesis in skeletal muscle in response to endurance exercises.

Repeated bouts of endurance exercise stimulates mitochondrial biogenesis in skeletal muscle. The synthesis of mitochondrial proteins involves a coordinated expression of both nuclear and mitochondrial genes. During this process, multiples sites of regulation have been identified at the transcriptional and translational levels. After their synthesis, mitochondrial proteins originating from the nuclear genome are imported into newly synthesized preexisting membranes and directed to one of the four mitochondrial subcompartments. The detailed mechanisms of the endurance training-induced mitochondrial biogenesis are still poorly understood. In particular, much work is needed to identify the molecular signals able to stimulate and coordinate the expression of mitochondrial proteins in response to endurance training. This will be a great help in the future to understand clearly the intimate mechanisms of mitochondrial biogenesis in skeletal muscle and the factors involved in endurance exercise performance.

Animals↗

PubMed1996

Effect of a 6-week endurance training programme and branched-chain amino acid supplementation on histomorphometric characteristics of aged human muscle.

The effects of a 6-week endurance training programme and a branched-chain amino acid (BCAA) supplementation were investigated on skeletal muscle histomorphometric characteristics of elderly men. Seventeen elderly men, age (63 +/- 5 years), height (173 +/- 5 cm) and weight (75 +/- 8 kg) were included in the study. One group (n = 9) received an oral BCAA supplementation for 6 weeks (16, 2 and 2 g per day of leucine, isoleucine and valine, respectively), while another group (n = 8) received a placebo. During these 6 weeks, subjects trained on a Monark cycle ergometer at 75 +/- 9% of their maximal heart rate for 1 h/day, 4 days/week. Muscle biopsy samples taken at rest before and after endurance training were analyzed for capillarization, fibre type distribution and fibre area. As a result of endurance training, maximal oxygen uptake was significantly increased by about 5% in control and BCAA supplemented groups (P < 0.01). The number of capillaries per fibre and in contact with type I fibres was significantly increased (P < 0.05), this effect being similar in control and BCAA supplemented groups. The percentage distribution and area of type I, type IIa and type IIb fibres did not differ between the two groups and remained unchanged with endurance training. It is concluded that skeletal muscle of elderly men can adapt to a 6-week endurance training programme and that a BCAA supplementation does not further enhance the induced histomorphometric changes.

Aged↗

PubMed1996

Determination of maximum aerobic velocity by a five minute test with reference to running world records. A theoretical approach.

Field measurement of the maximal aerobic velocity (MAV) is closely linked to effort-duration then to the used protocol. We construct the relationship between running speed and running-duration logarithm from running world records. It appears a noteworthy point at 4.97 minutes, to be suggested as MAV duration point. By agreement, MAV could be measured on field by a five minute test whatever the sport may be.

Aerobiosis↗

PubMed1996

[The PROGENE study, the French project of genetic analysis of familial prostatic cancer: recruitment and analysis].

OBJECTIVES: To initiate a genetic linkage study in order to localize one or several predisposition gene(s) for hereditary prostatic cancer (PC), as various epidemiological studies have demonstrated a possible family aggregation in about 25% of cases. A family segregation study [14] has also shown that a genetic predisposition, with autosomal dominant transmission and high penetrance (88% at 85 years) could be responsible for 9% of all PC. METHODS: A national collection of families with at least 2 cases of PC allowed: 1) identification of families with hereditary forms of PC, 2) creation of a constitutional DNA bank after collecting blood samples from subjects belonging to these families, and 3) a simulation study of genetic linkage analysis prior to microsatellite genotyping. RESULTS: From July 1994 to September 1995, we included 67 families (180 cases of PC). Another 45 families are currently being included. 24 of these 67 families (89 PC, 54 survivors) satisfied at least one of the criteria defined in the study by CARTER et al. for hereditary forms of familial PC. Two families were also included as the 3 patients with PC were second degree relatives. A total of 26 families therefore presented a hereditary form, 18 of which (73 PC, 46 survivors) were considered to be informative for a genetic linkage study (lod score = 4 for theta = 0.001 with an 8 allele marker). The constitutional DNA of 271 individuals of these informative families was extracted from circulating cells obtained from blood samples, immortalized lymphocytes, and the genotyping was initiated for 216 microsatellite markers distributed throughout the genome, an average of every 20 cM. CONCLUSION: Although the recruitment allowed us to identify many informative families for an inherited risk of PC, the predictive study suggested a high probability for localization of a predisposition gene by genetic linkage analysis. It would therefore be possible to identify, within the families concerned, the subjects carrying the genetic anomaly and consequently at high-risk of PC. Finally, the demonstration of the locus would allow cloning and identification of the gene (s) involved.

Female↗

PubMed1996

[Genetic aspects in cancers of the prostate].

The incidence of clinical prostate cancer varies across countries and ethnic groups. Genetic and epigenetic factors have been suggested as possible explanations to these variations, although no mesological factors with clearly significant effects have been identified. About 20% of patients with prostate cancer have a family history for this disease. Several studies have reported links between prostate cancer and breast cancer, suggesting that the same loci may predispose to both diseases. Identification of one or more inherited genes associated with an increased risk of prostate cancer in some families may be useful for identifying high-risk individuals. The value of this approach has been demonstrated in other familial cancers, such as colon and breast cancer. Current goals of research in this field are to localize the gene(s) that predispose to familial prostate cancer and to identify the molecular alterations related to tumor progression in sporadic and familial prostate cancer.

Humans↗

PubMed1995

Energetic status and mitochondrial oxidative capacity of rat skeletal muscle in response to creatine analogue ingestion.

A creatine analogue, beta-guanidinopropionic acid (beta-GPA), was administered in the food (1% w/w) of 8 male rats for 6 weeks, while 8 control rats received a standard diet. Mitochondrial oxidative capacity and cytosolic modulators of mitochondrial oxidative phosphorylation (free ADP, ATP-to-free ADP ratio) were evaluated in the soleus and extensor digitorum longus (EDL) muscles. Mitochondrial adaptation to the diet was significantly different between muscles. Citrate synthase activity and mitochondrial ATP synthesis rate were 35 and 45% higher in EDL muscle, respectively, whereas they were virtually unchanged in the soleus muscle. In both muscles, 3-hydroxyacyl-CoA dehydrogenase activity remained unaffected. Regardless of muscle type, creatine, phosphocreatine and ATP concentrations, as well as the total adenine nucleotide content (ATP + ADP + AMP), were significantly lower in beta-GPA fed rats. Whereas free ADP concentration remained unchanged, a significantly greater decrease in ATP-to-free ADP ratio was observed in EDL than in the soleus muscle. It is suggested that regulation of mitochondrial oxidative phosphorylation, through changes in metabolite concentrations, could be an important factor to consider for mitochondrial adaptation induced by beta-GPA feeding.

Adenine Nucleotides↗

PubMed1995

Loss of chromosome 3p arm differentiating tumorigenic from non-tumorigenic cells derived from the same SV40-transformed human mammary epithelial cells.

After immortalization of human normal mammary epithelial cells by replication-defective SV40 genome integration, 2 cultures were developed independently. Both had the same integration site, in band 9q21, but rapidly diverged karyotypically. After a few passages, one, designated SC2T2, exhibited near-diploid (a) and the other, designated SL2T2, near-tetraploid (b) karyotypes. The simplest formulas were 44, X, -X, der(3;22) (q10;q10), der(4) t(4;9)(q34;q12), +8, +9, add(13)(p1), der(19) t(8;19)(q21;p13.3), add(22)(p1) for karyotype (a) and 93, XXXX, add(1)(q12), add(11)(q13), +20 for karyotype (b). A number of alterations were further acquired with passages. Both cell cultures were tumorigenic, but their efficiency of grafting in nude mice largely differed: it was low for SL2T2 and high for SC2T2 cultures. All cultures of the xenografted tumors, obtained from either SL2T2 or SC2T2, exhibited the same clonal anomalies as those characterizing karyotype (a). It was concluded that only cells with karyotype (a) were tumorigenic, and that the difference in the tumorigenic potential of cultures SC2T2 and SL2T2 was related to their richness in cells with this karyotype. The comparison of the various karyotypes, together with data obtained in other cell types transformed by SV40, suggests that the acquisition of tumorigenicity in S2T2 mammary epithelial cells may be related to the loss of chromosome 3p arm.

Breast Neoplasms↗

PubMed1995

A microdissection approach to detect molecular markers during progression of prostate cancer.

To investigate the underlying mechanisms of carcinogenesis, we have developed a technique to determine the frequency of genetic changes in prostatic carcinoma tissue. We have demonstrated that at a ratio of between 1:4 and 1:9 mutant-normal alleles, the signal from a mutant TP53 allele is not apparent after polymerase chain reaction (PCR) amplification and further direct sequencing or single-strand conformation polymorphism (SSCP) analysis. To bypass this problem, which is inherent in the heterogeneity of the prostate tissue and of the tumour, we selected areas of graded prostate tumours (Gleason score) from cryosectioned preparations and microdissected these cells (20-100 cells). After anionic resin removal of proteins, PCR amplification of TP53 gene exons 5/6 and SSCP analysis, an abnormal SSCP band shift was observed in suspected tumour cells, compared with microdissected stromal cells used as an internal control, while (1) a crude preparation of tissue DNA carrying the tumour did not show any abnormality and (2) immunostaining by a set of monoclonal antibodies against TP53 protein remained negative. Nucleotide sequence analysis of the different bands confirmed the presence of a mutation in the TP53 gene exon 6 position 13,336 in an abnormal band for one specimen, while no mutation was detected in the normal SSCP band. By targeting recognised tumour cells we can find DNA mutations which are undetectable using the standard technique of whole-tissue DNA extraction, particularly in a heterogeneous tumour such as carcinoma of the prostate.

Base Sequence↗

PubMed1995

Mitochondrial ATP production rate in 55 to 73-year-old men: effect of endurance training.

The effect of 6-week endurance training on mitochondrial ATP production rate was investigated in 14 elderly men. Mean age, body weight and height were 63 +/- 6 yr, 75.6 +/- 9.2 kg and 174 +/- 4 cm, respectively. Subjects trained on a Monark cycle ergometer at 79 +/- 8% of their maximal heart rate for 1 h day-1, 4 days week-1. Muscle samples were obtained at rest, before and after endurance training, by a needle biopsy technique and used for determination of mitochondrial ATP production rate in isolated mitochondria and enzyme assays. Endurance training resulted in a significant increase in maximal oxygen uptake (L min-1) (P < 0.01). Citrate synthase activity, a mitochondrial marker enzyme, and hexokinase activity increased significantly (both P < 0.01) in response to training while 3-hydroxyacyl-CoA dehydrogenase and carnitine palmitoyltransferase I activities remained statistically unchanged. A higher mitochondrial ATP production rate was observed after endurance training with the substrate combinations pyruvate+palmitoyl-L-carnitine+L-glutamate+malate (P < 0.01), L-glutamate (P < 0.001), pyruvate+malate (P < 0.05) and palmitoyl-L-carnitine+malate (P < 0.01). The largest increase was obtained with L-glutamate (170%). Significant correlations were observed between the percent increase in citrate synthase activity and those of mitochondrial ATP production rates. It was concluded that the increased mitochondrial ATP production rate of aged human skeletal muscle with training seems mainly to occur through an increased mitochondrial content, and in a way similar to those observed in young men.

3-Hydroxyacyl CoA Dehydrogenases↗

PubMed1994

ATP synthesis kinetic properties of mitochondria isolated from the rat extensor digitorum longus muscle depleted of creatine with beta-guanidinopropionic acid.

A creatine analogue, beta-guanidinopropionic acid (beta-GPA), was administered in the food (1% w/w) of 8 male rats while 8 control rats received a standard diet. Mitochondrial oxidative capacity and kinetic parameters of mitochondrial ATP synthesis, apparent maximal ATP synthesis rate (Vmax) and apparent Michaelis constant for free ADP (Km), were investigated in the extensor digitorum longus (EDL) muscle. Mitochondrial ATP synthesis rate was measured by a bioluminescent method over a large range of ADP concentration (2-30 microM). As a result of the diet, Vmax was significantly increased (P < 0.05) while Km remained unchanged at around 20 microM. Citrate synthase (CS) and 3-hydroxyacyl-CoA dehydrogenase activities were significantly increased (both P < 0.05). Vmax was tightly correlated with CS activity (P < 0.001; r = 0.84). It was concluded that the increase in maximal mitochondrial ATP synthesis rate after beta-GPA feeding in EDL muscle was essentially due to a general increase in mitochondrial enzyme concentrations.

Adenosine Triphosphate↗

PubMed1994

Immunocytochemical comparison of cultured normal epithelial prostatic cells with prostatic tissue sections.

By analyzing a culture system of human prostatic epithelial cells (HPEC) and human prostatic fibroblasts (HPF) for expression of several determinants by immunocytochemistry, we have shown that long-term cultures are able to preserve the phenotypic characteristics of the normal tissue from which they are derived. The cytoskeletal elements, prostate-specific proteins, and steroid receptor profiles were compared to those of prostatic epithelium and stroma in situ. When cultured in low serum and low calcium medium, the adult HPEC grew as two layers of cells, the upper one of which retained the differentiation characteristics observed in the luminal fraction of normal prostatic epithelium. This cell type is the likely origin of prostatic neoplasia, with expression of CK8, 18, and 19 but not CK14. Androgen receptors, prostatic-specific antigen, and prostatic acid phosphatase are also expressed in vitro but at lower level than in situ. The lower cell layer expressed most of the same determinants but at a much lower level, suggestive of a stem-cell type. The HPF cultured in RPMI serum supplemented media retained the stromal pattern of the cells observed in situ. Culture systems which conserve the characteristics of their normal counterparts in vivo should provide useful models for studying in vitro genetic and epigenetic factors associated with differentiation and proliferation, but also with tumorigenic progression in the prostatic gland.

Biomarkers↗

PubMed1994

Humoral immune response to Salmonella abortusovis in sheep: in vitro induction of an antibody synthesis from either sensitized or unprimed lymph node cells.

In vitro culture conditions were determined to induce an anti-Salmonella abortusovis antibody synthesis from lymph node leucocytes of three immunized sheep and two unprimed lambs maintained in culture in the presence of heat-inactivated bacteria for 2 weeks. Humoral immune responses were assessed by enumerating specific antibody-secreting cells using ELISASPOT and by titrating immunoglobulins secreted into culture supernatants using ELISA techniques. Optimal secondary antibody response was observed from cultures performed with fetal calf serum (compared with horse serum) and with an antigen concentration of one to ten bacteria per cell. This kind of antigenic stimulation allowed induction of numerous antibody-secreting cells without adsorption of the secreted antibodies. Maximal numbers of antibody-secreting cells could reach a rate of 1% of the sheep leucocytes initially put into culture. Kinetic profiles of antibody production from boosted lymph node cells were characterized by an ascending phase from the sixth to the twelfth day of culture and then showed a plateau phase until Day 14. Most of the responses were composed of IgM and IgG1 antibodies, traces of IgG2 being detected at the end of experiments. From the twelfth day of antigenic stimulation, the IgM isotype was preferentially expressed with high antigen concentration (100 bacteria per cell), whereas the highest amounts of IgG1 were detected at lower concentration (one to ten bacteria per cell). While anti-Salmonella IgM appeared to be mainly specific for the lipopolysaccharide (LPS) cell wall fraction, some IgG1 recognized other bacterial antigens. Kinetic profiles and magnitudes of primary antibody responses induced in vitro from lamb lymph node cells did not differ from those defined in cultures of sheep boosted leucocytes. But these immune reactions were mainly made up of anti-LPS IgM. Few anti-Salmonella IgG1 were detected from the tenth day of culture. So these in vitro assays allowed induction of antibody synthesis from either in vivo sensitized or unprimed sheep lymph node leucocytes. This methodology would permit achievement of more detailed studies on interactions between Salmonella and lymph node leucocytes, leading to a better understanding of the mechanisms controlling bacterial dissemination through the lymphoid tissue.

Animals↗

PubMed1994

[Immunohistochemical localization in the intestine of swine of the cellular and humeral components of the immune response].

By immunohistochemistry, lymphocyte subsets of the swine gut were localized either in the epithelium or in the lamina propria. In addition, the distributions of class I and class II antigens were also characterized, using the streptavidin-biotin-peroxidase complex as the revelator; the endogenous peroxidase activity was distinguished from the specific by cobalt chloride. The results show a compartmentalization in the distribution of lymphocytes: in the epithelium, all the cells were T lymphocytes, the majority of the CD8 phenotype; in contrast, in the lamina propria, T and B cells were represented in similar proportions: T cells were constituted of both CD4 and CD8 cells (with slightly more CD4 than CD8 cells), while majority of B cells harboured the IgA isotype. Class I MHC was present on epithelium cells of both the villi and crypts. In contrast MHC class II was only present on epithelial cells of the villi. Both SC and IgA were localized in the epithelium cells of the crypt. Thus, this compartmentalization suggests the possibility of an immune response in the gut.

Animals↗

PubMed1993

Reactivity of workshop monoclonal antibodies with normal and pathological ovine lymph nodes.

The monoclonal antibodies (82 mAbs) included in the Second Workshop that belonged to agreed named bovine CD and workshop clusters were tested for their reactivity and tissue distribution on (1) normal sheep lymph nodes and (2) pathological sheep lymph nodes. Pathological lymph nodes were induced following experimental infection with Corynebacterium pseudotuberculosis and were characterized by the presence of typical pyogranulomas. Amongst the 82 mAbs tested, 38 reacted with sheep lymph nodes. The results of these tests are presented and discussed.

Animals↗

PubMed1992

Single-steep transformation of human breast epithelial cells by SV40 large T oncogene.

Normal human mammary epithelial cell (HMEC) cultures originating from 2 mammoplasty reduction surgical samples were transfected with replication-defective SV 40 DNA. Two independent cell lines designated as S2T2 and S1T3, selected for their increased proliferation potential and lifespan, were propagated for greater than 22 months in culture. They maintained a near-diploid karyotype with few chromosomal markers such as trisomy 1q (S1T3) and trisomy 8q (S2T2), which are most common in breast cancer in vivo. Immortalized S1T3 cells were not tumorigenic, whereas S2T2 cells produced slowly growing tumors in nude mice. One tumor was propagated in vitro and the transformed NS2T2 cell line subsequently raised 100% large tumors in the nude mouse. Rearrangement of the SV40 genome was observed in NS2T2 cells, which was not associated with increased expression of large T antigen. S1T3, S2T2 and transformed NS2T2 cell lines expressed cytokeratins CK18, CK19, the mammary-specific antigen DF3, and functional EGF receptors. Single-step immortalization and malignant transformation of human breast epithelial cells can thus occur upon transfection with SV40 large T oncogene. The chromosomal abnormalities observed in these cell lines suggest that they could offer a model for the study of breast-tumor progression in vitro.

Adult↗