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Biomedical subjects

F Rocher

Publications and source records attributed to F Rocher.

11 recordsLinked to original sources
PubMed2001

Comparison of the capsular response to the Biocell RTV and Mentor 1600 Siltex breast implant surface texturing: a scanning electron microscopic study.

The utility of mammary prosthesis texturing in the prevention of capsular contracture was established some 20 years ago. Various models of implant texturing are currently on the market. We decided to study two of the most popular implants with two different surface texturings: the Biocell RTV and the Mentor 1600 Siltex. An observation at the electron microscopic level of the implants' surfaces was achieved. At the time of a prospective survey on 10 patients, the capsule fragments corresponding to these two prostheses have been analyzed at the electron microscopic level. All prostheses were removed from the patients because of asymmetry or bad positioning. The aim of our study was to establish a correlation between these two frequent texturing surfaces and their corresponding capsules. Our results showed that only the Biocell's capsules present a mirror image with correspondence of the depressions on the prosthesis and contacts on the capsule. This phenomenon seems linked to the existence of a critical size of the pores constituting the implant surface. This observation leads us to the hypothesis of an adhesive effect between the prosthesis and its capsule. If this last is not directly linked to the prevention of capsular contracture, it can have an effect on implant stabilization in the primary mammary reconstruction and in the secondary corrections of asymmetry or bad position.

Breast↗
PubMed2001

Carrier-mediated uptake and phloem systemy of a 350-Dalton chlorinated xenobiotic with an alpha-amino acid function.

In a previous paper we have shown that epsilon-(phenoxyalkanecarboxylyl)-L-Lys conjugates are potent inhibitors of amino acid transport systems and that it is possible to modulate the uptake inhibition by hydrophobic or hydrophilic additions in the 4-position of the aromatic ring (J.F. Chollet, C. Delétage, M. Faucher, L. Miginiac, J.L. Bonnemain [1997] Biochem Biophys Acta 1336: 331-341). In this report we demonstrate that epsilon-(2,4-dichlorophenoxyacetyl)-L-Lys (2,4D-Lys), one of the largest molecules of the series and one of the most potent inhibitors, is a highly permeant conjugate. Uptake of 2,4D-Lys by broad bean (Vicia faba) leaf discs is mediated by an active carrier system (Km1 = 0.2 mM; Vmax1 = 2.4 nmol x cm(-2) x h(-1) at pH 5.0) complemented by an important diffusive component. Among the compounds tested (neutral, basic, and acidic amino acids, auxin, glutathione, and sugars), only the aromatic amino acids clearly compete with 2,4D-Lys. The conjugate accumulates in the vein network, is exported toward the growing organs, and exhibits a distribution pattern different from that of the herbicide moiety. However, over time 2,4D-Lys progressively splits into 2,4D and lysine. Analyses by high-performance liquid chromatography and liquid scintillation spectrometry of the phloem sap collected from the castor bean system, used as a systemy test, indicate decreasing capacities of 2,4D, 2,4D-Lys, and glyphosate, respectively, to move from the epidermis cell wall to the sieve element. Our results show that it is possible to design synthesis of large-size xenobiotics (approximately 350 D) with a lipophilic pole, exhibiting high mobility within the vascular system.

4-Chloromercuribenzenesulfonate↗
PubMed2001

[A scanning electron microscopy study of the surface of porous-textured breast implants and their capsules. Description of the "velcro" effect of porous-textured breast prostheses].

The efficacy of breast prosthesis texturing in the prevention of capsular contracture has been established for about 20 years. This successful procedure has led to the development and marketing of a number of different models. In the present study, four porous-textured breast prostheses have been examined: the Arion monoblock implant, the CUI (McGahn), the Biocell (Mcgahn), and the Sebbin LS21. Scanning electron microscopic (SEM) investigation of the implant surfaces of the different prostheses was carried out on new samples received from the manufacturers. During a prospective study on eight patients, capsule samples corresponding to the four above-mentioned prostheses were taken to determine whether a secondary intervention was necessary for correction of asymmetry or malpositioning. These samples were analyzed by SEM to investigate whether there could be a correlation between prosthesis texturing and the aspect of the corresponding capsules. Significant ultrastructural differences were found between the various prostheses examined: the results showed that only the CUI and Biocell prostheses presented a mirror image of the capsule texturing, with a correspondence between the depressions on the prosthesis and the contacts on the capsule. This finding seems to be linked to the existence of a critical size for the pores that constitute the implant surface. This observation led to the hypothesis of an adhesive "velcro" effect between the prosthesis and its capsule. Although the latter may not be directly linked to the prevention of capsular contracture it can, however, have a major effect on implant stabilization in cases of primary breast reconstruction and in possible secondary adjustments of asymmetry and malpositioning.

Adult↗
PubMed1995

Prognostic factors in chordoma: role of postoperative radiotherapy.

We have investigated prognostic factors for survival in a series of 26 patients with chordoma treated in Lyon, France, between 1979 and 1993. In this series, the median progression-free (PFS) and overall survival (OS) were 10 and 90 months, respectively. In univariate analysis, PFS, but not OS, was found significantly longer in males as compared to females (median: 19 versus 7 months, P = 0.05); and patients under 60 years of age had a longer PFS (median: 18 versus 6 months; P = 0.06) and OS (median: 108 versus 47+, P = 0.05) than older patients. A favourable prognostic subgroup including male patients under 60 years and a poor prognostic group including female patients and male over 60 years were thus defined (median PFS: 36 versus 6 months, P = 0.001; median OS: 108 versus 55+, P = 0.15). Primary treatment combining surgery and postoperative radiotherapy was associated with a longer PFS than surgery only (median: 36 versus 7 months, P = 0.002) in the whole series and in both prognostic subgroups.

Adult↗
PubMed1993

[Intraoperative radiotherapy in gastric adenocarcinomas. Apropos of 45 cases].

Intra-operative radiation therapy (IORT) is a multidisciplinary approach in which residual tumors or tumor beds are directly irradiated during a surgical procedure. To evaluate its efficacy we conducted since 1985 a prospective study including non metastatic gastric adenocarcinoma treated by surgery, IORT (15 Gy) and post-operative external beam radiotherapy (44 Gy). Up to now, 45 gastric adenocarcinomas (18 pNO and 27 pN1N2) have been included in the study. Mortality and morbidity rates were not different from those of surgery alone. Overall 5 year survival rate is 59.1% and pN1N2 5 years survival rate is 50.6%. These promising results are comparable with those of asian randomized studies which demonstrate the possible value of IORT in the treatment of gastric adenocarcinoma.

Adenocarcinoma↗
PubMed1990

In vivo activation of alveolar macrophages in ovine lentivirus infection.

Sheep infected by visna-maedi virus, a lentivirus related to the human immunodeficiency virus, develop a chronic interstitial lung disease. Since monocyte/macrophages are known to be specifically infected by visna-maedi virus, we investigated the role of macrophages in the appearance of pulmonary lesions in animals with naturally occurring disease. Alveolitis in maedi leads to a doubling in bronchoalveolar lavage total cell counts and of macrophages as compared to normal sheep. A significant increase in the relative percentage of neutrophils was also observed, accompanied by an increased spontaneous release of neutrophil chemotactic activity by alveolar macrophages of diseased animals, suggesting that they may be activated. Macrophage activation is also demonstrated by the observation of a significant (x3) increase of spontaneous fibronectin release by alveolar macrophages from maedi lungs, and furthermore by the high level expression of major histocompatibility complex class II antigens on most of these cells. Thus viral infection, although restricted to a small population of macrophages, is able to modulate extensive activation of macrophages in the lung. Activated macrophages release mediators likely to play a role in the development of the alveolitis and the parenchymal desorganization. These findings may be relevant to our understanding of the mechanisms by which human immunodeficiency virus infection leads to pulmonary disease other than that caused by opportunistic infections.

Animals↗
PubMed1987

Scintigraphy of the salivary glands in Sjögen's syndrome.

Scintigraphy of the salivary glands with technetium-sodium pertechnetate (99mTc) was undertaken on 320 patients with oral dryness or connective tissue disease using a computer assisted method that gave quantitative results about the major salivary gland function. Compared with clinical and histological data, scintigraphy provides a sensitive method, even though it is not specific, for detecting minimal injuries to salivary glands in patients suspected of having Sjögen's syndrome. Moreover, it might differentiate between the Sjögen-like syndrome and the sequelae of radiotherapy in patients with bone marrow graft. Scintigraphy of the major salivary glands could therefore form part of the routine investigation of patients with Sjögen's syndrome.

Adolescent↗
PubMed1984

[Gougerot-Sjögren syndrome. Functional study of the salivary glands by scintigraphy].

One-hundred and twenty patients with sicca syndrome, connective tissue disease or chronic graft-versus-host disease were investigated in the Saint-Louis Hospital Department of Nuclear Medicine. Technetium scanning of the salivary glands was performed in all patients. The results of the scintigraphic study were closely correlated with clinical and histological data in patients with Sjögren's syndrome. This method, which accurately quantifies the salivary function without danger nor discomfort to the patients, has a number of advantages: (a) it is sensitive enough to detect minimal salivary gland dysfunction; (b) it differentiates between parotid gland and submandibular gland involvement and demonstrates asymmetry in pathological processes; (c) it helps in following up patients with Sjögren's disease and in assessing the results of immunosuppressive or anti-inflammatory treatment.

Adolescent↗