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J Bourdon

Publications and source records attributed to J Bourdon.

At least 19 recordsLinked to original sources
PubMed1998

Regulation of myosin heavy chain gene expression after short-term diaphragm inactivation.

Although prolonged diaphragm denervation (DNV) produces myofiber atrophy and a loss of type I myosin heavy chain (MHC) expression, short-term DNV leads to significant diaphragm hypertrophy. The purpose of this study was to explore the regulation of MHC isoform expression and muscle remodeling during DNV hypertrophy of the diaphragm. Both unilateral and bilateral DNV led to similar changes, with a significant increase in total RNA content and muscle mass but no change in dry-to-wet weight ratio. Sarcomere number was also increased in diaphragm myofibers after DNV ( approximately 20%), suggesting an adaptive response to muscle stretch. There was hypertrophy of type I myofibers and increased coexpression of type I and type II MHCs within single myofibers by immunocytochemistry as well as increased type I MHC (25-46%) and decreased type IIb MHC (14-39%) by SDS-PAGE. Contractility parameters were also consistent with a type II-to-type I MHC phenotype transformation. Importantly, DNV-induced modulation of MHC isoform mRNA transcript levels did not correspond to changes in their cognate proteins, suggesting a major degree of posttranscriptional control. We conclude that DNV hypertrophy of the diaphragm is associated with reciprocal changes in type I and type II MHC isoforms that are directly opposed to the type I-to-type II MHC phenotype transformation reported in the diaphragm DNV atrophy model. Furthermore, in contradistinction to most hypertrophy models, control of MHC gene expression and myofibrillar remodeling after short-term DNV appears to entail major involvement of posttranscriptional regulatory mechanisms.

Animals↗
PubMed1996

Phenotypic and immunologic factors affecting plasmid-mediated in vivo gene transfer to rat diaphragm.

Little is known about the molecular mechanisms governing adaptive responses of the diaphragm in the setting of lung disease. By permitting the study of regulatory elements and the effects of overexpressing genes of interest, direct in vivo gene transfer to the diaphragm could be used as a tool to address such questions. Therefore, we evaluated parameters affecting transfection efficiency and duration of foreign gene expression in the diaphragm after plasmid-mediated gene transfer. Reporter gene constructs were injected into adult rat diaphragm and hindlimb muscles. Transfection efficiency at 8-10 days postinjection was decreased in large caliber ( > 1,000 microns2) and type II myosin heavy chain (MHC)-expressing fibers. There were also strong trends toward augmented transfection efficiency in type I MHC- and embryonic MHC-expressing fibers. All diaphragms demonstrated evidence of muscle injury and inflammatory cell infiltrates at this early time point. By 30 days postinjection, however, neither inflammation nor reporter gene expression was detectable in diaphragm or hindlimb muscles of immunocompetent animals. By contrast, immunosuppressed rats (given cyclosporine; 15 mg.kg-1. day-1) showed high levels of foreign gene expression at 30 days postinjection, which remained stable up to 60 days. Therefore, exploitation of plasmid-mediated in vivo gene transfer as a tool for studying regulated gene expression in the diaphragm may be facilitated by the use of immunodeficient animal models.

Animals↗
PubMed1995

Efficiency and functional consequences of adenovirus-mediated in vivo gene transfer to normal and dystrophic (mdx) mouse diaphragm.

The protein dystrophin is absent in muscles of patients with Duchenne muscular dystrophy (DMD) as well as in mdx mice. The mdx mouse diaphragm closely resembles the human DMD phenotype and should serve as an appropriate model for future studies of dystrophin gene replacement. In this regard, recombinant adenovirus (AV) holds great promise as a vector for delivering a functional dystrophin gene to muscle. However, the use of AV is hampered by the development of an immune response against transduced cells, resulting in short-lived transgene expression as well as possible adverse effects on organ function. In the present study, sensitive reporter genes were employed to determine the efficiency and functional consequences of AV-mediated gene transfer to the diaphragm in both normal and mdx adult mice. One week after direct intramuscular injection of AV into the diaphragm, the level of transgene expression was significantly increased in mdx compared with normal diaphragms. In addition, small-caliber fibers (< 500 microns2) demonstrated preferential transduction in both groups of mice. Normal diaphragms receiving AV exhibited a substantial reduction in maximal twitch and tetanic force generation, whereas no significant effect on diaphragm contractility was found in the mdx group at 1 wk after injection. At 1 mo after AV administration, however, there was a significant decrease in force production by both normal and mdx diaphragms. Immunosuppression with cyclosporine A over 1 mo did not augment the level of transgene expression, but a beneficial effect on diaphragm force-generating capacity was observed in both groups of animals. We conclude the following: (1) short-term transduction of the diaphragm is more efficient in mdx than in normal mice; (2) AV leads to reduced force production by the diaphragm, with this effect being more pronounced in normal than in mdx in the early (but not the late) postinjection period; and (3) immunosuppressive therapy with cyclosporine has a partially protective effect on muscle function after AV administration, which is apparently unrelated to sparing of transduced fibers from elimination by the host immune system. These findings have important implications for the application of AV-mediated dystrophin gene transfer to the treatment of DMD.

Adenoviruses, Human↗
PubMed1995

[The treatment of genito-urinary prolapse with promonto-fixation using a prosthetic material combined with complete hysterectomy: complications and results apropos of a series of 55 cases].

From May 1986 to May 1992, 55 patients with genitourinary prolapse were treated by total hysterectomy, sacral fixation using a prosthetic band and colposuspension. The mean age was 55.5 years (range: 38-78 years). Ten patients (18.8%) developed early postoperative complications: 2 wall haematomas, one surgical revision for haemorrhage, one case of haematemesis secondary to a duodenal ulcer, one intestinal obstruction due to dehiscence of the peritonealisation, two cases of acute urinary retention, one case of complete urinary incontinence, one septic shock and one wall abscess. Three patients (5.4%) developed late postoperative complications: intestinal obstruction secondary to a mesenteric band, one incisional hernia, and one case of pelvic pain. The mean length of hospital stay was 8.9 days (range: 7-25 days) and the mean follow-up was 36 months (range: 6-72 months). The anatomical result was excellent (complete correction of the prolapse and absence of recurrence) in 96.4% of cases. In terms of the functional results, 3 patients (5.4%) remained dysuric and 5 (9.1%) have persistent stress incontinence, either moderate (3 cases) or disabling (2 cases). Marked sphincter insufficiency was demonstrated on the urethral pressure profile in these last two cases. The combination of total hysterectomy with vaginal opening and sacral fixation using a prosthetic band prevents the risk of subsequent disease of the remaining cervix and does not appear to increase the risk of infection or the postoperative morbidity. Without advocating systematic hysterectomy in the sacral fixation technique, we nevertheless believe that it is preferable to perform total hysterectomy rather than supraisthemic hysterectomy when this procedure is indicated.

Adult↗
PubMed1994

Cloning of a parathyroid hormone/parathyroid hormone-related peptide receptor (PTHR) cDNA from a rat osteosarcoma (UMR 106) cell line: chromosomal assignment of the gene in the human, mouse, and rat genomes.

Complementary DNAs spanning the entire coding region of the rat parathyroid hormone/parathyroid hormone-related peptide receptor (PTHR) were isolated from a rat osteosarcoma (UMR 106) cell-line cDNA library. The longest of these clones (rPTHrec4) was used to chromosomally assign the PTHR gene in the human, rat, and mouse genomes. By somatic cell hybrid analysis, the gene was localized to human chromosome 3 and rat chromosome 8; by in situ hybridization, the gene was mapped to human chromosome 3p21.1-p22 and to mouse chromosome 9 band F; and by interspecific backcross analysis, the Pthr gene segregated with the transferrin (Trf) gene in chromosome 9 band F. Mouse chromosome 9 and rat chromosome 8 are known to be highly homologous and to also show synteny conservation with human chromosome 3. These three chromosomes share the transferrin gene (TF), the myosin light polypeptide 3 gene (MYL3), and the acylpeptide hydrolase gene (APEH). Our results add a fourth gene, the PTHR gene, to the synteny group conserved in these chromosomes.

Animals↗
PubMed1994

[The use of the Babcock forceps for hemostasis of the pre-prostatic veins in radical prostatectomy of total cystoprostatectomy].

Haemostasis of Santorini's venous plexus during radical prostatectomy or total cystoprostatectomy is a delicate phase of the procedure which facilitates the conditions of the surgery and the postoperative course. Based on a series of 150 prostatectomies, the authors describe their technique using Babcock forceps for "en bloc "ligation of the venous plexus. After opening the pelvic aponeurosis and section of the puboprostatic ligaments, a Babcock forceps is placed above the urethra and prostatic apex, including all of Santorini's plexus enclosed by its fibrous tissue, allowing exposure of the abascular plane of cleavage situated between the anterior surface of the urethra and this plexus. Klikenberg scissors are then introduced into the depression formed underneath the jaws of the Babcock forceps and are guided by the index finger into the symmetrical depression of the other side. The hypogastric connective tissue is perforated lateromedially and the scissors are gently opened to enlarge the passage. A right-angle dissector is then inserted and grips n.1 or 2 absorbable suture material which, after removing the Babcock forceps, is used to tie all of the anterior venous complex. This technical device allows a more reproducible and standardised approach to this operative step.

Cystectomy↗
PubMed1993

Molecular characterization of an intragenic minisatellite (VNTR) polymorphism in the human parathyroid hormone-related peptide gene in chromosome region 12p12.1-p11.2.

The human parathyroid hormone-related peptide (hPTHrP) gene in chromosome region 12p12.1-p11.2 plays an important role in mammalian development and specifically in skeletogenesis. We have characterized a VNTR polymorphism in the hPTHrP gene that is located in an intron 100-bp downstream of exon VI that encodes a 3' untranslated region. By PCR analysis eight different alleles were identified in a group of 112 unrelated individuals. All eight alleles were sequenced and the repeat unit was identified as the general sequence [G(TA)nC]N, where n = 4 to 11 and N = 3 to 17. This polymorphic sequence-tagged site will be useful for mapping chromosome 12p and will aid in testing for linkage of genetic diseases to the hPTHrP gene.

Alleles↗
PubMed1969

[Homosexuality].

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Anxiety, Castration↗
PubMed1968

[Not Available].

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Diet↗
PubMedDate not supplied

[Prostatic involvement in leukemia. Report of a case].

Infiltration of the prostate is frequent in the course of leukaemia. It is usually asymptomatic or may present in the form of classical bladder neck obstruction. The diagnosis is generally established during investigation of benign prostatic hypertrophy by biopsy or during treatment by resection. Treatment of leukaemia by systemic chemotherapy is unable to sterilize the prostatic site and must therefore be combined with local radiotherapy.

Aged↗