Evidence of an environmental reservoir for emergent Mycobacterium colombiense.

Mycobacterium colombiense, which belongs to the M. avium complex, is reported to have been isolated from cases of disseminated infection in both immunocompromised and immunocompetent patients. During the isolation of protists from water samples in French Guyana, we co-isolated a flagellated green alga (Polytoma sp.) and a mycobacterium identified as M. colombiense.

Correlative light electron microscopy of giant viruses with the SECOM system.

Bright-field transmission electron microscopy (TEM), TEM-negative staining technique, resin-embedding and ultramicrotomy, scanning TEM, scanning electron microscopy, atomic force microscopy and cryoelectron microscopy are imaging techniques used for describing giant viruses, their cycle and ultrastructure. Here we used the SECOM system, an integrated correlative light and electron microscopy using light and electronic imaging without sample transfer, to study cells infected with giant viruses, as shown by Tupanvirus, the ultrastructure of which was successfully observed. An improvement of the SECOM system with an eye to its use in fundamental and clinical research could be considered in the field of microbiology.

Early pulmonary endothelial enzyme dysfunction after phorbol ester in conscious rabbits.

We investigated changes in angiotensin converting-enzyme (ACE) activity before and at 5, 15, 60, and 240 min after 20 micrograms phorbol myristate acetate/kg body wt iv in conscious rabbits. ACE activity was estimated in vivo from the single-pass transpulmonary metabolism of the synthetic substrate [3H]benzoyl-Phe-Ala-Pro [( 3H]BPAP) under first-order reaction conditions. Within 5 min after PMA administration, all animals developed profound granulocytopenia (15% of control) and moderate thrombocytopenia (57% of control), both lasting for the duration of the experiment. Concomitantly, there was a significant decrease in the transpulmonary metabolism of [3H]BPAP and the calculated apparent first-order reaction constant Amax/Km of ACE for [3H]BPAP. No histological evidence of lung injury was observed at these times. Since a concomitant fall in the permeability surface area product for urea was also observed, we considered that the apparent decline in ACE activity might have resulted from a reduction in perfused endothelial surface area. To resolve this, we studied the effect of PMA on the Km (a measure of enzyme affinity for its substrate) and Amax (a derivative of Vmax that is dependent upon total enzyme present and thus capillary surface area) of ACE and 5'-nucleotidase for [3H]BPAP and [14C]AMP, respectively. A significant increase in Km for both enzymes was observed at 1 h after PMA, whereas Amax was unaffected, suggesting that low-dose PMA may indeed produce endothelial cell enzyme dysfunction independent of its effect on capillary surface area. These results provide evidence of pulmonary capillary functional injury before or in the absence of structural endothelial damage.

[External fixation devices in maxillofacial surgery]. / Les fixateurs externes en chirurgie maxillo-faciale.

External fixation devices have relatively little application in stomatology, but they are indispensable in certain situations. Equipment presently available for use by maxillofacial surgeons is relatively reduced in number, and two new fixation devices are proposed : a Jacquet type miniaturized fixation device and one of the Sorem type particularly adapted for the mandible.

[Biometric data using follow-up x-ray computed tomography of the morphological and structural changes of mandibular bone reconstructions using hydroxyapatite-collagen-GAG]. / Données biométriques par suivi TDM de l'évolution morphologique et structurale de reconstructions osseuses mandibulaires par hydroxyapatite-collagène-GAG.

The use of biomaterials for bone reconstruction raises the problem of their architectural and structural outcome. CT makes an accurate biometric follow-up possible. The association of HA, collagen and GAG appears to be a reliable substitute for bone, owing to the permanence of the dimensional results and to the structural evolution that seems to finally provide total structural restoration.

[Use of a cup-shaped implant of polydioxanone in orbital-malar fractures]. / Utilisation de la cupule en PDS dans les fractures orbito-malaires.

Treatment of orbito-malar trauma has two priorities; restoration of the pelvi-orbital integrity and recovery of malar stability. Numerous techniques using various materials, whether or not of autologous origin, have been developed with this aim in mind. The authors report their experience with the PDS bioresorbable orbital prosthesis within the framework of orbito-malar trauma.

[Sports and facial injuries. Feasibility and limitations of an epidemiologic study]. / Sports et traumatismes faciaux. Tentative et limites d'une étude épidémiologique.

Our aim was to conduct an epidemiological study in order to better assess the frequency of maxillo-facial sport injuries. Only those activities that are practised within a sport or game association are included in the study. A standard letter was sent to all French sport and game associations (Olympic or not) as well as to some major insurance companies (73 sport and game associations and 11 insurance companies). However the scope of the study rapidly proved limited since over the two-month period considered only 16 sport associations and one insurance company returned an answer. The exploitable results are presented and a brief overview of the recent relevant international studies is given.

Alpha-fetoprotein-mediated targeting of anti-cancer drugs to tumor cells in vitro.

An oncofetal protein, human alpha-fetoprotein, was selected as a vector molecule for targeted delivery of antitumor substances. Conjugates of alpha-fetoprotein with doxorubicin, daunomycin, calichemicin, carboxyphosphamide, bleomycetin, chlorbutin, cis-platinum, methotrexate were synthesized. All conjugates displayed a highly selective antitumor cytotoxic activity towards human cell cultures. The optimal alpha-fetoprotein:cytotoxic compound ratio was shown to be 1:3 - 1:5. The results obtained serve as a basis for creating antitumor preparations of a new generation, which are highly selective to tumor cells owing to receptor-mediated endocytosis.

Primary Th1 cell immunization against HIVgp160 in SCID-hu mice coengrafted with peripheral blood lymphocytes and skin.

SCID-hu mouse models are of interest in the pathologic investigation of HIV infection, but obtaining a T cell response in SCID-hu-PBL mice is still controversial. We have developed a SCID model by engrafting human skin and autologous PBLs from HIV-seronegative individuals. The study describes the ability of this human-mouse chimera to generate in vivo a primary T lymphocyte response against HIV Ag. The injection of human autologous PBLs was performed 4 to 5 wk after the skin engraftment. Two weeks after injection of PBLs, chimeric mice were immunized with recombinant canary pox virus expressing HIV-1 LAIgp160 (vCP-LAIgp160) and supplemented or not with rIL-2. Intradermal vCP-LAIgp160 injection induced an intradermal perivascular human lymphocytic infiltrate and an epidermic network of CD1a+, CD80+, and CD86+ cells. We derived CD4+ T cell lines (STLs) from the human skin graft of immunized mice, showing that STLs mediated an MHC class II-restricted cytolytic activity directed against HIV-LAIgp160 Ags. Cytokine gene expression in both human skin cells and in STLs showed a predominance of IL-2, IFN-gamma, and IL-12 transcripts. Finally, the T cell repertoire analysis using the immunoscope technique showed a very limited CDR3 length polymorphism in the skin infiltrating lymphocytes suggesting an Ag-specific repertoire. The ability to induce a primary Th1 cell response in vivo affords a useful preclinical model for testing vaccine strategies.