Search

The limited capability to predict material failure in composite materials and specifically in wavy composite layers has led to high margins of safety for the design of composite structures. Thus, the full lightweight potential of this class of materials is left unused. To understand the complex failure behavior of composite materials containing out-of-plane fiber waviness under compressive and tensile loading, a non-linear 2D material model was implemented in ABAQUS and validated with extensive experimental test data from compression and tensile tests. Each test was recorded by a stereo camera system for digital image correlation to resolve damage initiation and propagation in detail. This study has shown excellent agreement of numerical simulations with experimental data. In a virtual testing approach various parameters, i.e. amplitude, wavelength and laminate thickness, have been studied. It was found that the failure mode changed from delamination to kink shear band formation with increasing laminate thickness. The wavelength has shown minor influences compared to amplitude and laminate thickness. [ABSTRACT FROM AUTHOR]

Background DC-presenting tumor Ag are currently being developed to be used as a vaccine in human cancer immunotherapy. To increase chances for successful therapy it is important to deliver full-length tumor Ag instead of loading single peptides. Methods In this study we used a fiber-modified adenoviral vector (rAd5F35) containing full-length tumor Ag cDNA to transduce human monocyte (Mo)-derived DC in vitro . Cells were efficiently transduced and survived for at least 3 days after adenoviral transduction. Phenotype and function after maturation of Mo-DC were not impaired by infection with adenovirus particles. Expression of the tumor-associated Ag mucin-1 (MUC1) was detected using MAb defining different MUC1 glycoforms. Results Non-transduced mature Mo-DC express endogenous MUC1 with normal glycosylation. After transduction with the rAd5F35-MUC1 adenoviral vector, Mo-DC also expressed MUC1 with tumor-associated glycosylation (Tn and T glycoforms), although no changes in mRNA levels of relevant glycosyltransferases could be demonstrated. Discussion The presence of aberrantly glycosylated MUC1 may influence Ag presentation of the tumor glycoforms of MUC1 to immune cells, affecting tumor cell killing. These findings could be highly relevant to developing strategies for cancer immunotherapy based on DC vaccines using MUC1 as tumor Ag. [ABSTRACT FROM AUTHOR]

The expression of laminin and fibronectin isoforms varies with cellular maturation and differentiation and these differences may well influence cellular processes such as adhesion and motility. The basement membrane (BM) of fetal oral squamous epithelium contains the laminin chains, α2, α3, α5, β1, β2, β3, γ1 and &gamma2. The BM of adult normal oral squamous epithelium comprises the laminin chains, α3, α5, β1, β3, γ1 and γ2. A re-expression of the laminin α2 and β2 chains could be shown in adult hyperproliferative, dysplastic and carcinomatous lesions. In dysplasia and oral squamous cell carcinoma (OSCC), multifocal breaks of the BM are present as indicated by laminin chain antibodies. These breaks correlate to malignancy grade in their extent. Moreover, in the invasion front the α3 and γ2 chain of laminin-5 can immunohistochemically be found outside the BM within the cytoplasm of budding carcinoma cells and in the adjacent stroma. The correlation between the morphological pattern of invasive tumour clusters and a laminin-5 immunostaining in the adjacent stroma may suggest, first, that a laminin-5 deposition outside the BM is an immunohistochemical marker for invasion and second, that OSCC invasion is guided by the laminin-5 matrix. Expression of oncofetal fibronectins (IIICS de novo glycosylated fibronectin and ED-B fibronectin) could be demonstrated throughout the stromal compartment. However, the ED-B fibronectin synthesizing cells (RNA/RNA in situ hybridization) are confined to small stroma areas and to single stroma and inflammatory cells in the invasion front. A correlation of the number of ED-B fibronectin synthesizing cells to malignancy grade could not be seen. ED-B fibronectin mRNA-positive cells seem to be concentrated in areas of fibrous stroma recruitment with a linear alignment of stromal fibro-/myofibroblasts (desmoplasia). Double staining experiments... [ABSTRACT FROM AUTHOR]

OBJECTIVES: To investigate whether disturbance of the cellular homoeostasis and integrity of cardiomyocytes in dilated cardiomyopathy (DCM) is accompanied by alterations in cell-matrix relations as indicated by changes in the deposition of fibronectin (FN) isoforms. DESIGN: Tissue from a case series of patients with DCM was investigated by immunohistochemistry with antibodies against FN (all variants, clone IST4), ED-A+ FN (clone IST9), ED-B+ FN (clone BC1), and oncofetal glycosylated FN (clone 5C10). The sites of de novo synthesis of FN were demonstrated by means of non-radioactive RNA in situ hybridisation (ISH) with biotinylated FN cDNA fragments as the probe. SETTING: University hospital. PATIENTS: Samples from 10 patients with clinical criteria and histological diagnosis of DCM and from 3 individuals with normal hearts. INTERVENTIONS: Samples were obtained by right ventricular endomyocardial biopsy. MAIN OUTCOME MEASURE: Distribution of oncofetal FN variants in DCM hearts. RESULTS: Immunostaining of FN (IST4, all variants) showed a coarse interstitial network in normal and diseased myocardium. ED-A+ FN was deposited as fine interstitial spots in normal myocardium and in DCM samples. Immunostaining for oncofetal glycosylated FN and ED-B+ FN was not seen in normal adult myocardium, whereas myocardium from DCM patients showed focal and delicate staining in the interstitium. RNA ISH showed that these deposits resulted from local FN synthesis. CONCLUSION: The results accord with de novo expression of oncofetal FN variants in hearts from patients with DCM. The oncofetal FN variants may serve as disease markers in myocardium affected by DCM. [ABSTRACT FROM PUBLISHER]

Cell surface carbohydrates serve as differentiation and developmental markers characteristic of different cell and tissue types. The expression of these carbohydrate antigens is often significantly altered in tumors, particularly in those arising from epithelial tissues. Analysis of cell surface carbohydrates in oral epithelium have shown that in normal epithelium they are expressed in a way that shorter carbohydrates are found on basal cells and that these carbohydrate structures are elongated parallel to terminal differentiation. The carbohydrate expression is altered in oral carcinomas and in some oral premalignant lesions. The change in carbohydrate expression can at present be explained by the lack of synthesis of specific glycosyltransferases. We have found mosaicism in the expression of carbohydrate antigens in all tumors and have found that the expression of a specific carbohydrate in the deep invasive parts of the tumor correlates with tumor prognosis. [ABSTRACT FROM AUTHOR]

Cell surface carbohydrates serve as differentiation and developmental markers characteristic of different cell and tissue types. The expression of these carbohydrate antigens is often significantly altered in tumors, particularly in those arising from epithelial tissues. Analysis of cell surface carbohydrates in oral epithelium have shown that in normal epithelium they are expressed in a way that shorter carbohydrates are found on basal cells and that these carbohydrate structures are elongated parallel to terminal differention. The carbohydrate expression is altered in oral carcinomas and in some oral premalignant lesions. The change in carbohydrate expression can at present be explained by the lack of synthesis of specific glycosyltransferases. We have found mosaism in the expression of carbohydrate antigens in all tumors and have found that the expression of a specific carbohydrate in the deep invasive parts of the tumor correlates with tumor prognosis. [ABSTRACT FROM AUTHOR]

Recent studies have shown that changes within membrane bound carbohydrates may be essential for cellular differentiation and malignant transformation. We have therefore, by means of immunohistochemistry, studied the expression of T/Tn related (Thomsen-Friedenrich) carbohydrates in 13 oral lesions with squamous cell dysplasia. The epithelial grade of dysplasia was graded as mild, moderate or severe. The following carbohydrate structures were studied: Tn, T, mucintype 3 chain H, and the sialylated derivates, sialosyl-Tn and sialosyl-T. In general, short structures were detected on the basal cells and longer structures on the more mature spinous cells. In many cases, this sequential expression was more disturbed with increasing grade of epithelial dysplasia. However, our results also showed that some lesions with the same grade of epithelial dysplasia showed different carbohydrate expression. These findings indicate that expression of carbohydrates may supplement histologic diagnosis in the evaluation of the prognosis of premalignant lesions. [ABSTRACT FROM AUTHOR]

The histo-blood group ABO carbohydrate antigens are differentially expressed in epithelia in close correlation with cellular differentiation. In order to gain insight into the biosynthetic regulation of these carbohydrate antigens, we correlated the expression of A carbohydrate antigens with that of the A gene defined glycosyltransferase by immunohistology of' human oral epithelia using monoclonal anti- bodies. In glandular epithelium the A transferase was found in mucous cells similar to that of the A carbohydrate antigens. In stratified non-keratinized squamous epithelium the A transferase was expressed only in spinous cell layers, which is in accordance with the appearance of the A carbohydrate antigens in these more mature cell layers. This simultaneous acquisition of the primary and secondary gene product of a glycosyltransferase gene, provides evidence that the well-defined sequential expression of histo-blood group carbohydrate antigens in stratified squamous epithelium may be directly regulated at the transcriptional level of the glycosyltransferase. Future studies will address the nwchanism behind loss of A antigens in premalignant lesions and carcinomas. [ABSTRACT FROM AUTHOR]

Two distinct mucin components of saliva, MG1 and MG2, have been identified based on chemical composition and molecular weights (high and low, respectively) in saliva. With the aim of characterizing the expression pattern of salivary mucins, we have prepared monoclonal antibodies (MAbs) directed against the peptide core of MG1 and against a synthetic peptide derived from the MG2 (MUC7) sequence. MAb PANH2 raised against partially deglycosylated MG1 stained a high-molecular-weight smear in Western blots of partially purified MG1. PANH2 binding was increased by deglycosylation with trifluoromethanesulfonic acid as well as with subsequent periodate treatment, and was eliminated by pronase treatment, strongly suggesting that MAb PANH2 was directed to a peptide epitope of MG1. MAb PANH3 raised against a synthetic peptide derived from the MG2 (MUC7) sequence reacted with the native molecule and stained a narrow smear of ca. 200,000 to 210,000 in Western blots of concentrated saliva and a lower-molecular-weight smear of trifluoromethanesulfonic-acid-treated MG2. Immunohistology on frozen sections of human salivary glands showed that MAb PANH2 selectively labeled mucous cells, whereas MAb PANH3 labeled subpopulations of serous cells. Double-direct immunofluorescence staining with PANH2 and PANH3 demonstrated that the staining pattems were non-overlapping. The development of these antibody probes will facilitate studies of mucin expression in diseases of salivary glands. [ABSTRACT FROM AUTHOR]

Type-1 chain histo-blood group antigens such as the Lewis (Le)a, monosialosyl-Le(a), Le(b) and H antigens show an increased expression in endometrial carcinomas. However, the possibility that these antigens are expressed under genetic or hormonal influence in endometrial carcinomas has not been considered. In the present study, the expression of type-1 chain carbohydrate antigens in normal and malignant endometrium was evaluated by immunohistochemistry and related to both genetic and hormonal factors. The glands of normal, non-secretory endometria expressed, in contrast with surface epithelial cells, Le(a), Le(b), disialosyl-Le(a), and H determinants infrequently. Adenomatous hyperplasias and endometrial carcinomas showed an increased expression of type-1 chain carbohydrates that was qualitatively influenced by the erythrocyte Lewis phenotype and the secretor status. Whereas Le(a+b-) non-secretors mainly accumulated Le(a) antigen, and only limited amounts of Le(b) antigen, Le(a-b+) secretors expressed H, Le(b) and Le(a) antigens. The expression of type-1 chain antigens showed no association with the serum-oestrogen level or to the hormone-receptor status. Thus the Lewis secretor status has a qualitative influence on the increased expression of type-1 chain antigens, which, however, seem to be unrelated to hormonal factors. Our findings suggest an increased activity of the Se-gene-defined or a closely related fucosyl-transferase in neoplastic endometrial epithelial cells. [ABSTRACT FROM AUTHOR]

Changes in expression of histo-blood group ABH and Lewis antigens are common alterations in carcinomas. Using immunohistochemistry, we have evaluated the expression of type-2 histo-blood group antigens in normal and malignant endometrial tissues in relation to genetic and hormonal factors. The Le(x), sialosyl-Le(x), and Le(y) antigens were inconstantly expressed in the normal endometrium. The expression was uninfluenced by the secretor status but was related to the ABO blood group status in Oestradiol (E2) stimulated endometria. Le(y) was expressed most frequently in proliferating endometria from blood group 0 individuals. Le(x) and Le(y) were maximally expressed in atrophic endometria, and Le(x) and Le(y) staining scores correlated inversely with serum levels of E2 in normal, non-secretory endometria. No correlation was found in adenomatous hyperplasias and endometrial carcinomas, which when compared with atrophic endometria, showed a loss of Le(x) and Le(y) and an increased H-carbohydrate expression at apical membranes. Carcinomas from non-secretors showed lower expression of Le(y) and H-antigens than carcinomas from secretors. Our findings suggest that the genetic and hormonal influence on glycosylation based on type-2 chain carbohydrates differ between normal and malignant endometrium. This difference is probably related to specific tumour-associated qualitative and quantitative changes in the fucosyltransferases. [ABSTRACT FROM AUTHOR]

A panel of monoclonal antibodies was used to examine differentiation-related carbohydrate structures on the surfaces of gingival epithelial cells. The patterns of binding observed indicate distinct differences in the expression of the epitopes examined for three regions of the gingival epithelia corresponding approximately to the regions defined anatomically as the junctional, oral sulcular and oral epithelia. However, epitheium with the staining pattern of oral sulcular epithelium consistently extended beyond the sulcular region to cover the gingival crest and often the uppermost pan of the oral aspect of the gingiva. Differential staining of basal and suprabasal cells indicated an unusual pattern of differentiation of the junctional epithelium. The phenotype of this epithelium appears to differ from patterns reported for any other oral epithelium and the possible functional significance of this difference is discussed. [ABSTRACT FROM AUTHOR]