Objective Carcinomas of the colon and rectum are the third leading cause of cancer-related deaths. Although advances in the surgical treatment of primary colorectal cancers have lead to improvements in patient survival at early tumor stages, treatment of more progressive cancers has not resulted in dramatic improvements in patient survival. However, the selection of patient subgroups based on their prognosis and other characteristics could result in improved outcomes from adjuvant therapies in patients with Dukes B and C carcinomas. Methods The authors reviewed the available data on the value of cell surface molecules in assessing the prognosis of colorectal carcinomas, paying specific attention to the evaluation of statistical analysis and multivariate procedures. Results Cell surface molecules have been identified on colorectal carcinoma cells whose expression appears to be related to malignant transformation, tumor progression, or patient prognosis. Among these cell surface molecules, various cell adhesion molecules, growth factor receptors, proteinases, and their receptors and inhibitors have been identified as potentially useful prognostic markers. Conclusions Although data exist on the prognostic values of certain cell surface markers, the use of multivariate analysis for the identification of valuable prognostic factors remains uncommon. Using reproducible and standardized multivariate analysis procedures, new tumor markers should be carefully examined for their biologic and prognostic relevance before being considered as potentially useful in the management of colorectal cancers.

Integrin-mediated tumour cell adhesion to extracellular matrix (ECM) components is an important step in the development of metastatic lesions. Thus, integrin expression and integrin-mediated adhesion of colon carcinoma cells to various ECM components was examined. Poorly (HT-29P) and highly (HT-29LMM) liver-metastatic colon carcinoma cells were used to study the rates of adhesion to collagen I (C I), collagen IV (C IV), laminin (LN), fibronectin (FN), or vitronectin (VN) in a static adhesion assay (10-120 min). Cells were untreated or treated with oligopeptides (RGD, GRGDS, YIGSR, RGES), anti-integrin antibodies, or colchicine, nocodazole, cycloheximide, acrylamide or cytochalasin D (to disrupt cytoskeletal structures). Both cell lines expressed similar patterns of integrin expression (alpha2, alpha3, ,alpha6, alphav, beta1, beta4, and beta5) by immunocytochemistry and immunoprecipitation. HT-29LMM cells showed significantly higher rates of adhesion to LN (P < 0.001) and FN (P < 0.001), but significantly poorer rates of adhesion to C I (P < 0.05) and C IV (P < 0.001) than HT-29P cells, respectively, adhesion to VN was insignificant. RGD and GRGDS inhibited HT-29LMM cell adhesion to FN only. Pretreatment with anti-beta, or anti-alpha2 integrin subunits suppressed adhesion to C I and C IV, and adhesion to LN was inhibited with anti-beta1 or anti-alpha6 integrin. Anti-beta1 or anti-alphav blocked adhesion to FN. Pretreatment of cells with cytochalasin D, cycloheximide or acrylamide inhibited adhesive interactions of both cell lines to the ECM components. In contrast, colchicine and nocodazole had no effect. The results demonstrate that adhesion of HT-29 cells to ECM is mediated, in part, by different integrins, depending on the substrate. Poorly and highly metastatic HT-29 cells possessed different patterns of adhesion to the various ECM substrates, but these differences were not due to different expression of integrin subunits. The results also suggested that the initial adhesion of poorly or highly metastatic HT-29 cells to ECM components requires, in part, the presence of native action and intermediate filaments, but not of microtubules. Thus the adhesion of tumour cells to ECM components may be dependent on signal transduction and assembly of microfilaments.

Organ-specific sites of metastastic lesions are determined in part by integrin-mediated adhesion to extracellular matrix (ECM) components. Using poorly (HT-29P) and highly liver-metastatic (HT-29LMM) colon carcinoma cells we previously found different integrin-mediated adhesion to various ECM components, but similar inte-grin expression of both cell lines. These HT-29 cell lines were used to study adhesion to collagen I (C I) and possible intracellular signaling mechanisms that could explain different adhesive properties. HT-29LMM cells had significantly poorer rates of adhesion to C I (P<0.05) than HT-29P cells. For examination of the integrin subunits involved in adhesion to C I, cells were treated with various anti-integrin antibodies. These results demonstrated that adhesion of HT-29 cells to C I is mediated in part by the α2β1 integrin. Using immunoprecipitation and Western blotting, both cell lines expressed similar patterns of integrins (α2, α3, α6, and β1). Weaker signals were found for the expression of αv and β5 integrins. Although poorly and highly metastatic cells possessed different patterns of adhesion to C I, these differences were not caused by different expression of integrin subunits. For investigation of the involvement of phosphotyrosine kinases in adhesion, cells were pretreated with the Erbstatin analog, Genistein, or Herbimycin A. Genistein transiently stimulated the adhesive properties of both cell lines. In contrast, Herbimycin A had biphasic effects. At lower concentrations of Herbimycin A stimulation of adhesion was found after 30 and 90 min. However, higher concentrations inhibited adhesive properties. The stimulatory effect was more pronounced in poorly metastatic HT-29P cells. The Erbstatin analog had no effect, probably because of the lack of epidermal growth factor receptor expression in both cell lines. The results suggest that adhesion of tumor cells to ECM components may be dependent on signal transduction into the cell, and tyrosine phosphorylation appears to be involved.

OBJECTIVE Mycoplasmal infections are associated with several acute and chronic illnesses. Some mycoplasmas can enter a variety of tissues and cells, and cause system-wide or systemic signs and symptoms. METHODS Patients (14 female, 14 male) diagnosed with rheumatoid arthritis (RA) were investigated for mycoplasmal infections in their blood leucocytes using a forensic polymerase chain reaction (PCR) procedure. Amplification was performed with genus- and species-specific primers, and a specific radiolabelled internal probe was used for Southern hybridization with the PCR product. Patients were investigated for the presence of Mycoplasma spp., and positive cases were further tested for infections with the following species: M. fermentans, M. hominis, M. pneumoniae and M. penetrans. RESULTS The Mycoplasma spp. sequence, which is not entirely specific for mycoplasmas, was amplified from the peripheral blood of 15/28 patients (53.6%) and specific PCR products could not be detected in 13 patients (46.4%). Significant differences (P < 0.001) were found between patients and positive healthy controls in the genus test (3/32) and in the specific tests (0/32). Moreover, the incidence of mycoplasmal infections was similar in female and male patients. Using species-specific primers, we were able to detect infections with M. fermentans (8/28), M. pneumoniae (5/28), M. hominis (6/28) and M. penetrans (1/28) in RA patients. In 36% of the patients, we observed more than one Mycoplasma species in the blood leucocytes. All multiple infections occurred as combinations of M. fermentans with other species. CONCLUSIONS The results suggest that a high percentage of RA patients have systemic mycoplasmal infections. Systemic mycoplasmal infections may be an important cofactor in the pathogenesis of RA, and their role needs to be explored further.

The aim of this study was to investigate the presence of different mycoplasmal species in blood samples from patients with chronic fatigue syndrome and/or fibromyalgia syndrome. Previously, more than 60% of patients with chronic fatigue syndrome/fibromyalgia syndrome were found to have mycoplasmal blood infections, such as Mycoplasma fermentans infection. In this study, patients with chronic fatigue syndrome/fibromyalgia syndrome were examined for multiple mycoplasmal infections in their blood. A total of 91 patients diagnosed with chronic fatigue syndrome/fibromyalgia syndrome and with a positive test for any mycoplasmal infection were investigated for the presence of Mycoplasma fermentans, Mycoplasma pneumoniae, Mycoplasma hominis and Mycoplasma penetrans in blood using forensic polymerase chain reaction. Among these mycoplasma-positive patients, infections were detected with Mycoplasma pneumoniae (54/91), Mycoplasma fermentans (44/91), Mycoplasma hominis (28/91) and Mycoplasma penetrans (18/91). Multiple mycoplasmal infections were found in 48 of 91 patients, with double infections being detected in 30.8% and triple infections in 22%, but only when one of the species was Mycoplasma pneumoniae or Mycoplasma fermentans. Patients infected with more than one mycoplasmal species generally had a longer history of illness, suggesting that they may have contracted additional mycoplasmal infections with time.

Die Entwicklung von Fernmetastasen ist der lebenslimitierende Faktor beim Kolon-Karzinom. Die Lokalisation einer Tumormetastasierung wird im Wesentlichen nicht von anatomischen Gegebenheiten des Blutflusses, sondern von Wechselwirkungen zwischen Tumorzelle und Wirtsorgan bestimmt. Bei der hämatogenen Metastasierung kommt es zu einer selektiven Kolonisierung von Tumorzellen in verschiedenen Organen. Bei der Wechselwirkung zwischen Tumor-und Endothelzelle (EC) oder extrazellulärer Matrix (ECM) haben Adhäsionsmoleküle entscheidende Funktionen sowohl beim Primärkontakt wie auch für die definitive Adhäsion und Zellmigration im Wirtsorgan [1]. Es müssen Bindungen erreicht werden, die den durch den Blutfluß entstehenden Scherkräften entgegenwirken.

Poorly and highly liver metastatic colon carcinoma cell lines have different integrin-mediated adhesion to extracellular matrix. Specific integrin-mediated interactions between tumor cells and extracellular matrix (ECM) in the host organs are important for organ-specific metastasis. In colon carcinoma integrin expression differs depending on the metastatic potential of the tumor. Integrin-mediated adhesion of poorly (HT-29P) and highly liver-metastatic (HT-29LMM) colon carcinoma to extracellular matrix (ECM; Collagen I-C I, Collagen IV-C IV, Laminin LN, Fibronectin FN, Vitronectin VN) was investigated. HT-29LMM showed significant better adhesion to LN (45% vs. 26%; p < 0.001) and FN 20% vs. 1%; p < 0.001). No adhesion was found to VN. RGD-oligopeptides completely inhibited adhesion to FN. Using inhibition with anti-integrin-mAB it was shown, that adhesion to C I and C IV is mediated by alpha 2 beta 1-integrin, adhesion to LN by alpha 6 beta 1 and adhesion to FN by alpha v beta 1. These results have shown that adhesion of HT-29 cells is mediated by different integrins depending on ECM components. Poorly and highly metastatic cells possessed different patterns of adhesion to various substrates.

Acidic anionic residues on the surfaces of the hamster eggs and spermatozoa were investigated using a colloidal iron hydroxide (CIH)-labeling technique. Both the zona pellucida and the plasma membrane of the egg are abundant in acidic anionic residues, and no obvious changes in the densities or distributions of these residues were detected before and after fertilization. Also, the relative distribution and density of acidic anionic residues on the plasma membranes of spermatozoa are not markedly changed during sperm capacitation, indicating that the number and distribution of anionic residues, per se, are probably not directly involved in this process. Prior to fusion of sperm and egg plasma membranes, the sperm head plasma membrane does not bind CIH, but once fusion has started the fused sperm—egg membrane does bind CIH. This suggests that the sperm and egg plasma membrane components intermix during gamete fusion.

The relative density and distribution of acidic negative residues on the plasma membranes of spermatozoa of seven mammalian species were studied using a colloidal iron hydroxide (CIH) labeling technique. The surface distribution of negative residues is discontinuous on mature spermatozoa from the cauda epididymidis or on ejaculated spermatozoa of the rabbit, mongoose, rat, guinea pig and hamster. Tail regions are generally more densely labeled with CIH than head regions, indicating that sperm tails have more acidic negative charges than heads. In these species, the density of the negative surface charge is rather uniform within a particular segment of the spermatozoa and abruptly changes at the junctions to morphologically distinct segments, suggesting that the biochemical properties of the plasma membrane also change at these junctions. In bull (cauda epididymal) and human (ejaculated) spermatozoa, the entire surfaces of spermatozoa are densely labeled with CIH. Comparison of testicular, caput and cauda epididymal spermatozoa of rabbit, bull and hamster suggests that the negative surface charges of spermatozoa increase with epididymal maturation of spermatozoa. A possible chemical nature of the residue(s) has been suggested from neuraminidase digestion and methylation experiments.