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Biomedical subjects

J M Peron

Publications and source records attributed to J M Peron.

At least 19 recordsLinked to original sources
PubMed2002

[Management of cleft lip and palate in university hospital of Rouen].

Cleft lips and cleft palates are managed in the department of Pediatric surgery in Rouen for the last 30 years. From the antenatal diagnosis, the parents got in touch with the surgeon who will coordinate this management. Around thirty new patients are treated every year. The chronology of the treatment is of "classic" manner. The cleft lip is repaired at about 3 weeks of age and the palatoplasty is performed after the age of 1 year. In view to maintain the intimacy of the consultation we did not institute multidisciplinary consultations. The other members of the interdisciplinary team will intervene during the follow up depending on the form of the cleft and the encountered problems. The information and the files circulate freely and are discussed together.

Academic Medical Centers↗
PubMed2000

Interleukin-12 and Flt3 ligand differentially promote dendropoiesis in vivo.

Interleukin-12 (IL-12) and Flt3 ligand (FL) regulate hematopoiesis by stimulating proliferation, differentiation and migration of progenitor and/or stem cells. In this study, we evaluated the in vivo effect of IL-12 alone or in combination with FL on dendritic cell (DC) generation and accumulation in murine spleen, lymph node, thymus, liver, and tumor tissues. Both cytokines induced accumulation of functional DC in lymphoid and non-lymphoid tissues. IL-12 promoted predominantly myeloid dendropoiesis, while FL induced both myeloid and lymphoid dendropoiesis. Combination treatment resulted in a dramatic increase in CD86+, and particularly, NLDC-145+ cells within the liver, which was largely due to cell proliferation. Combination therapy also revealed the ability of FL to protect bone marrow cell populations from IL-12-induced depletion in vivo. In vitro, we found a significant FL-induced up-regulation of IL-12 production by DC at both mRNA and protein levels. Thus, our study suggests that (i) the antitumor activity of IL-12 may, at least in part, be mediated by the stimulation of dendropoiesis and (ii) IL-12 might contribute to the antitumor activity of FL. Furthermore, induction of DC generation in vivo by a combination of IL-12 and FL might become a new approach for immunotherapy of cancer.

Animals↗
PubMed2000

The expression of CD70 and CD80 by gene-modified tumor cells induces an antitumor response depending on the MHC status.

The expression of costimulatory molecules such as CD70 or CD80 by gene-modified tumor cells has been shown to enhance the antitumor immune response based mainly on T lymphocytes. However, most human tumors show defects of major histocompatibility complex (MHC) expression, preventing them from being recognized by MHC-restricted T cells. To investigate if coexpression of CD70 and CD80 costimulatory molecules induces comparable antitumor responses in low and high MHC-expressing tumor cells, we used two low immunogenic murine tumor models, the B16.F10 melanoma and the TS/A mammary adenocarcinoma cell lines expressing, respectively, low and high levels of MHC class I molecules. Transfection of both CD70 and CD80 genes resulted in an increased capacity of gene-modified tumor cells to costimulate in vitro the proliferation and cytokine production of optimally activated lymphoid cells. Coexpression of CD70 and CD80 by the two tumor cell lines, TS/A and B16.F10, resulted in both cases in partial regression of subcutaneous tumors. Immunochemical analysis and studies in nude mice showed that, even in the B16.F10 model, T cells had a significant role in the antitumor response induced by combining CD70 and CD80. However, rejection of the CD70/CD80-transfected tumor cells appeared more effective in the MHC class I high TS/A model, leading to a protection against parental tumor cells. B16.F10 and TS/A transfectants were then tested with fibroblasts genetically modified to secrete interleukin-12 (IL-12) as a therapeutic vaccine in mice bearing parental tumors. In the two models tested, the injections of irradiated IL-12 and CD70/CD80 gene-modified cells generated an antitumor response to established tumors leading to the slowing down of the tumor growth rate. Although the mechanisms remain to be defined, these findings suggest that the combination of several immuno-modulatory molecules could provide additional strategies for cancer immuno-gene therapy, even for MHC expression-deficient tumors.

Animals↗
PubMed2000

[The nonhealing of the buccal mucosa after tooth extraction. Apropos a case of histiocytosis X].

We report a case of eosinophilic granuloma falsely diagnosed as a radicular cyst in a 28-year-old patient. Between August 1996 and June 1997, successful extraction [correction of avulsion] of teeth 36 and 37 was followed by non-healing of the mucosa in the corresponding sockets. Three bone biopsies were needed to establish the diagnosis of histiocytosis X. In case of non-healing of the intraoral mucosa after tooth extraction [correction of avulsion], the first step is to rule out a malignant tumor. A clinical and radiographic work-up as well as biopsy are needed. Less common conditions such as tuberculosis or histiocytosis X requiring specific treatment can be diagnosed by pathology.

Adult↗
PubMed1999

Differential regulation of epidermal and dermal dendritic cells by IL-12 and Flt3 ligand.

An abrogation of the decline in epidermal Langerhans cell numbers above melanoma might significantly improve the efficacy of immunotherapy for melanoma treatment. Systemic Flt3 ligand (FL) administration in mice induced a significant increase in mature dendritic cells (DC) within the skin, preferentially in the dermis, whereas IL-12 promoted a significant increase of immature DC preferentially in the epidermis. Both effects were abrogated in IL-12 knockout mice. Thus, IL-12 could promote FL-induced accumulation of skin DC. The involvement of FL and IL-12 in the regulation of DC accumulation within the skin may contribute, at least in part, to the stimulation of antimelanoma immunity by FL- and IL-12-based immunotherapies. Moreover, FL and IL-12 could be used for selective in vivo generation of DC in either epidermis or dermis for experimental and clinical purposes.

Animals↗
PubMed1998

[A comparison of standard radiographs and "scout-view" radiographs. The value for cephalometric analysis].

Is the scout-view as reliable as the standard lateral view for cephalometric analysis? Cephalometric data (Delaire analysis) were obtained in ten patients with CT-scan and standard x-ray for comparison. Qualitative results showed imprecisions for craniofacial contours and soft tissue ptosis. Quantitative results were analyzed statistically and revealed a significantly higher level of error with scout-view tracings. The scout-view does not appear to be as reliable and takes longer to acquire than the standard lateral x-ray: for the pediatric population, it could be a disadvantage.

Adult↗
PubMed1998

[Oral aphthae induced by nicorandil. Anatomopathologic aspects. Apropos of a case].

Major apthous stomatitis induced by nicorandil is exceptional, the mechanism is still unknown and the histological aspect of these lesions have not been previously reported. Our case reports a man who was treated by nicorandil for coronary artery disease. He was referred for major aphtous stomatitis; one element was biopsied. The histological aspect was an aspecific sialadenitis, with granulous reaction, and without vasculitis or eosinophilic infiltration. We conclude that aphtous stomatitis induced by nicorandil could to be explain by a toxic effect, rather than a toxicallergic or immunologic mechanism.

Aged↗
PubMed1998

[Therapeutic management of traumatic avulsion of permanent teeth].

Management of avulsed permanent teeth requires perfect knowledge of the different parameters influencing the short and mid-term and above all long-term prognosis. Based on a review of the literature and the analysis of 50 cases cared for in our unit enables us to propose, in accordance with the extra oral delay and the degree of dental maturation, a protocol for the different emergency situations. This clarification emphasizes the contribution of new preserving solutions which allow reimplantation delays up to 24 hours without effect on prognosis.

Ankylosis↗
PubMed1997

Histopathologic analysis of transjugular intrahepatic portosystemic shunts.

This prospective study was undertaken in 17 patients treated with 22 transjugular intrahepatic portosystemic shunt (TIPS) procedures and aimed to evaluate the nature and causes of short- and long-term shunt abnormalities. Specimens were collected after autopsy in 6 patients and after liver transplantation in 11 patients; the time from shunting ranging from 4 to 385 days. During the first 2 weeks the shunt surface was covered by poorly organized fibrin platelet clots that were mixed with inflammatory and red blood cells. Thereafter, a pseudointima developed, initially made of loose granulation tissue that was formed by edema, myofibroblasts, neo-capillaries, collagen fibers, and inflammatory cells. This pseudo-intima extended with time as the myofibroblasts increased in number, as the collagen fibers thickened, and as the inflammatory cells grew more scarce. Its thickness ranged from 50 to 3,500 microm, the maximal values being observed in the middle of the shunt. The shunt was obstructed by a clot in 4 patients (18%). In 7 shunts (31.8%) the pseudo-intima was thicker than 1,000 microm and was referred to as hyperplastic pseudo-intima. It showed more dense inflammatory infiltrate and anarchic deposition of more scarce collagen fibers. Pseudo-intima hyperplasia was associated with previously diagnosed thrombosis, which had been treated by dilatation in 2 cases and by biliary deposits in 3 cases, while it remained unexplained in 2 cases. Accordingly, this study confirms the following: 1) that early TIPS obstruction results from thrombosis; 2) that 2 weeks after insertion, the stent is covered by a smooth pseudo-intima; 3) that thereafter, pseudo-intimal hyperplasia is the main cause of TIPS stenosis or occlusion; and 4) that biliary secretions and previous thrombosis could be important triggering mechanisms for this pseudo-intima overgrowth.

Adult↗
PubMed1997

Small bowel obstruction: role and contribution of sonography.

The purpose of this study was to determine whether sonography provides additional clinical information in patients suspected of small bowel (SB) obstruction. During a period of 30 months, in a prospective setting, we evaluated with sonography 123 patients suspected of SB obstruction. Sonographic examinations of the entire abdomen were performed with state-of-the-art, real-time, grey-scale equipment. Fourteen patients were labelled 'gassy' and no added information was provided following abdominal ultrasound. Sonography confirmed the SB obstruction in 82 cases with 5 false positives, resulting in a specificity of 82.1 %. Sonographic examinations were negative in 27 cases with 4 false negatives and a sensitivity of 95 %. The accuracy was 91.7 % when the 'gassy' patients were excluded and 81.3 % overall. The aetiology of the ileus was detected by sonography in 13 cases of paralytic ileus (54.1 %) and in 57 cases of mechanical ileus (71.4 %). It is concluded that ultrasound, which is a non-invasive, portable and even bedside imaging procedure, appears accurate in confirming a SB obstruction and in determining the aetiology of SB obstruction.

Adolescent↗
PubMed1994

[Popliteal pterygium syndrome. A exceptional case].

We report the case of a patient with a popliteal pterygium syndrome, a rare malformation associating, in its complete form, cleft lip and cleft palate, cleft lower lip, intergingival synechia, defects of the genito-urinary tract and popliteal pterygium. Based on this observation and a review of the literature, the phenotypic and genotypic aspects of this malformation were discussed together with adapted therapeutic management and genetic counselling.

Abnormalities, Multiple↗