Worldwide first experiences with vacuum-assisted closure as alternative treatment method to repair defects of an extended thoracic wall recurrence of breast cancer

Introduction  

Loco-regional recurrences of the breast cancer are associated with a bad prognosis. Often costly autologous-tissue treatment as a surgery aiming at repairing the defects is necessary.     

Artemis C-terminal region facilitates V(D)J recombination through its interactions with DNA Ligase IV and DNA-PKcs

Artemis is an endonuclease that opens coding hairpin ends during V(D)J recombination and has critical roles in postirradiation cell survival. A direct role for the C-terminal region of Artemis in V(D)J recombination has not been defined, despite the presence of immunodeficiency and lymphoma development in patients with deletions in this region. Here, we report that the Artemis C-terminal region directly interacts with the DNA-binding domain of Ligase IV, a DNA Ligase which plays essential roles in DNA repair and V(D)J recombination. The Artemis-Ligase IV interaction is specific and occurs independently of the presence of DNA and DNA-protein kinase catalytic subunit (DNA-PKcs), another protein known to interact with the Artemis C-terminal region. Point mutations in Artemis that disrupt its interaction with Ligase IV or DNA-PKcs reduce V(D)J recombination, and Artemis mutations that affect interactions with Ligase IV and DNA-PKcs show additive detrimental effects on coding joint formation. Signal joint formation remains unaffected. Our data reveal that the C-terminal region of Artemis influences V(D)J recombination through its interaction with both Ligase IV and DNA-PKcs.     

Round-Headed Spermatozoa: A Model to study the Role of the Acrosome in early events of Gamete Interaction: Rundkopfspermatozoen: Ein Modell zum Studium der Rolle des Akrosoms

Gamete interactions in mouse involves at least two steps: the first is the interaction of a spermatozoa receptor located in the plasma membrane and ZP3, a zona pellucida (ZP) glycoprotein. ZP3 also can induce the acrosome reaction, making possible the second step: a closer interaction between ZP2 and an inner acrosomal membrane receptor. Our aim was to study gamete interaction in round-headed spermatozoa to determine at which functional level fertility is impaired. These spermatozoa are predominant in some infertile male and are characterized by the absence of acrosome; they also present an abnormal pattern of chromatin condensation. Human ZP and zona free hamster oocytes were used to study gamete interaction. No binding to ZP was observed either with light or electron microscopy. Our findings suggest that the presence of the acrosome could be necessary for the sorting and right organization of plasma membrane proteins. Round-headed spermatozoa could also present a general alteration of membrane protein synthesis. The lack of fusion with zona-free hamster oocytes may be explained by an altered reorganization of plasma membrane proteins in the post acrosomal region as a result of the absence of the acrosome reaction in round headed spermatozoa.     

Monoclonal antibodies to molluskan hemocyanin from Concholepas concholepas demonstrate common and specific epitopes among subunits

We studied the reactivity of mouse monoclonal antibodies (MAbs) against the hemocyanin from the Chilean marine gastropod Concholepas concholepas (CCH). This protein has been successfully used as a carrier to produce antibodies to haptens and peptides. All MAbs (13) belonging to IgG subclass exhibit dissociation constants (K(d)) from 1 x 10(-7) M to 1 x 10(-9) M. MAbs were characterized by enzyme-linked immunosorbant assay (ELISA) using CCH treated with different procedures, including dissociation into CCH-A and CCH-B subunits, Western blot, enzymatic digestion, chemical deglycosylation, and thermal denaturation. MAbs were classified into three categories, according to subunit specificity by ELISA. The epitope distribution shows that CCH subunits display common epitopes (group I, 5 MAbs, 1H5, 2A8, 3A5, 3B3, and 3E3), as well as specific epitopes for CCH-A subunits (group II, 3 MAbs, 1B8, 4D8, and 8E5) and for CCH-B subunits (group III, 5 MAbs, 1A4, 1E4, 2H10, 3B7, and 7B4). The results can be summarized as follows: (1). six antibodies react with thermal denatured CCH, suggesting that they recognize linear epitopes, whereas seven recognize conformational epitopes; (2). oxidation of carbohydrate moieties does not affect the binding of the MAbs; (3). enzymatic digestion of CCH decreases the reactivity of all antibodies irrespective of the protease used (elastase or trypsin); (4). bringing together the above data, in addition to epitopic complementarity analysis, we identified 12 different epitopes on the CCH molecule recognized by these MAbs. The anti-CCH MAbs presented here can be useful tools to understand the subunit organization of the CCH and its complex structure, which can explain its immunogenic and immunostimulating properties in mammals.     

A direct interaction between the RAG2 C terminus and the core histones is required for efficient V(D)J recombination

V(D)J recombination is a tightly controlled process of somatic recombination whose regulation is mediated in part by chromatin structure. Here, we report that RAG2 binds directly to the core histone proteins. The interaction with histones is observed in developing lymphocytes and within the RAG1/RAG2 recombinase complex in a manner that is dependent on the RAG2 C terminus. Amino acids within the plant homeo domain (PHD)-like domain as well as a conserved acidic stretch of the RAG2 C terminus that is considered to be a linker region are important for this interaction. Point mutations that disrupt the RAG2-histone association inhibit the efficiency of the V(D)J recombination reaction at the endogenous immunoglobulin locus, with the most dramatic effect in the V to DJ(H) rearrangement.     

Females of the communally breeding rodent, Octodon degus, transfer antibodies to their offspring during pregnancy and lactation

Females in numerous rodent species engage in communal nesting and breeding, meaning that they share a nest to rear their young together. One potential benefit to communally nesting mothers is that infants improve their immunocompetence. Thus, suckling from two or more females might provide newborns with a more diverse array of antibodies and defensive cells. As a first step toward testing the immunocompetence hypothesis, we assessed whether female degus (Octodon degus), a communally nesting and breeding caviomorph rodent, transfer immunoglobulins to their young through the yolk sac or placenta while in the uterus and, during lactation, through milk. With this aim, adult degu females were immunized with four antigens, including two mollusk hemocyanins from Concholepas and Megathura (CCH and KLH, respectively), porcine thyroglobulin and tetanus toxoid. Specific antibodies against the experimental antigens were used to track the origin of antibodies in the young. To establish the presence of specific antibodies of IgG and IgA isotypes in sera and milk of animals, an indirect enzyme-linked immunosorbent assay (ELISA) was developed. Degu females produced specific antibodies against antigens not found in their natural environment, and mothers were able to transfer the induced antibodies to their litters during pregnancy (IgG) and during lactation (IgA). However, we recorded only limited evidence of degu offspring acquiring antibodies from lactating mothers other than their own, giving little support to the increased immunocompetence hypothesis.     

Development of monoclonal antibodies bearing the internal image of the gizzerosine epitope and application in a competitive ELISA for fish meal

Gizzerosine (GZ), a derivative of histamine, is a biogenic amine found in fish meal, and one of the causative agents of black vomit, a poultry disease. We describe here the preparation of anti-idiotype antibodies to the anti-GZ monoclonal antibody (anti-GZ 3H4) and their possible application to an immunoassay. BALB-c mice were immunized with anti-GZ 3H4 antibody coupled to hemocyanin from Concholepas concholepas. Using somatic cell fusion between NSO/2 cells and splenic lymphocytes from the immunized mice, we obtained 34 potential anti-idiotype antibodies. They were characterized by passive agglutination with supernatants from hybridoma cultures and latex particles conjugated to the idiotype. Anti-idiotype antibodies were analyzed by a competitive RIA, to determine their ability to dissociate the interaction between (125)I-GZ and the anti-GZ 3H4-idiotype antibody. They were also characterized by GZ inhibition of latex passive agglutination assay. Three anti-idiotypes named 2D11, 2H6, and 3A12, all of the IgG isotype, were obtained. They were evaluated by a competitive ELISA, in which GZ competes with the tracer (HRP-idiotype). All presented sensitivity in the range of 0.1-10 microg/mL of GZ; and the 3A12 anti-idiotype antibody showed the best performance. An ELISA was developed using the idiotype bound to the solid phase and the anti-idiotype 3A12-HRP as the tracer. The assay showed a similar sensitivity and cross-reactivity with histamine was only observed at concentrations over 10 microg/mL. Lysine and histidine did not interfere with the assay up to 500 microg/mL. An experiment was conducted with fish meal contaminated with synthetic GZ. The results are promising, and showed that no other compounds of the fish meal interfere with the ELISA system; however the extraction procedure of the sample needs to be improved. From the results presented here, we conclude that the idiotype anti-idiotype ELISA would be an appropriate method to determine GZ in fish meal.     

Toxic effect of a photo-induced tryptophan-riboflavin adduct on F9 teratocarcinoma cells and preimplantation mouse embryos

Solutions containing L-tryptophan and riboflavin exposed to visible light, under N2 atmosphere, yield a tryptophan-riboflavin adduct, able to inhibit the growth of cultured F9 teratocarcinoma cells. This same effect was found in the presence of a mixture of the tryptophan photooxidation products and the adduct, when using solutions previously irradiated with visible light in an O2 atmosphere. A cytotoxic effect was also observed with embryos incubated in the presence of a tryptophan-riboflavin adduct, in the latter case necrosis and embryo development arrest occurred.     

Inhibitory effect of nordihydroguaiaretic acid and its tetra-acetylated derivative on respiration and growth of adenocarcinoma TA3 and its multiresistant variant TA3MTX-R

The effects of nordihydroguaiaretic acid (NDGA) and its tetraacetylated derivative (NDGATA) on the growth, oxygen consumption, adenosine 5'-triphosphate (ATP) level and viability of mouse mammary adenocarcinoma TA3 and its multiresistant variant TA3-MTX-R cell lines were determined. NDGA inhibited mitochondrial carbonyl cyanide m-chlorophenylhydrazone (CCCP)-stimulated oxygen consumption in mouse liver and tumor cells when glutamate plus malate or succinate was added as substrate. The effects were considerably weaker when respiration was supported by duroquinol, indicating that NDGA inhibited primarily mitochondrial electron flow located at some point before ubiquinone. Although NDGATA only inhibited the electron flow through complex I, it was more efficient and selective than NDGA because mouse liver mitochondria were significantly less sensitive to it than both tumor cell lines tested. NDGA and NDGATA inhibited mitochondrial ATP synthesis and, consequently, cell viability and growth rate were also decreased. NDGA and NDGATA inhibited the growth of intramuscularly implanted tumor cells, indicating that NDGATA was also antineoplastic in vivo. In conclusion, NDGATA is cytotoxic to tumor cells, provoking selective induction of mitochondrial dysfunctions, which could be interesting as potential antitumoral agent.