Mineralization behaviour of collagen type I immobilized on different substrates

Collagen type I as a robust fibre protein and main component of the extracellular matrix of most tissues is increasingly utilized for surface engineering of biomaterials using different immobilization methods. In the present work we studied the mineralization behaviour of fibrillar collagen type I in simulated body fluid as a measure for conformational changes caused by adsorptive immobilization or immobilization by partial incorporation into the anodic oxide layer on c.p.-titanium using microscopic and vibration spectroscopic methods. Adsorptive immobilization on highly oriented pyrolytic graphite (HOPG) and c.p.-titanium without collagen were used as references. In the initial phase (1-24 h) the kinetics of formation and the morphology of calcium phosphate phases (CPP) are strongly influenced both by the substrate and the immobilization method. Compared to HOPG both types of immobilization on titanium increasingly inhibit the formation of CPP. For longer times (30 d) these initial differences disappear-mineralization product on titanium, irrespective of the presence of collagen, is a mixture of amorphous calcium phosphate and octacalcium phosphate. Contrary to this the mineralization of HOPG substrates results in hydroxy apatite. This is discussed with respect to the conditions during the immobilization as well as the resulting interactions between substrate and immobilized collagen. It is shown that the mineralization process exhibits a high sensitivity with respect to conformational changes caused by these interactions. Possible cell biological relevance of these conformational changes is discussed.     

In-vitro adhesion of endometrium to autologous peritoneal membranes: effect of the cycle phase and the stage of endometriosis

BACKGROUND: Endometrium can adhere to autologous peritoneum. This study was undertaken to determine the effect of the menstrual cycle phase and the presence and stage of endometriosis on in-vitro adhesion of endometrium onto autologous peritoneum. METHODS: This was performed in an academic medical research centre. Sixty-seven subfertile women with a visually normal pelvis (n = 18) and with biopsy-proven endometriosis (n = 49) were included. Endometrial and peritoneal biopsies were obtained at laparoscopy during menstrual, follicular and luteal phase. Endometrium was cultured in vitro with autologous peritoneum, followed by fixation, paraffin embedding, serial sectioning, hematoxylin-eosin and immunohistochemical staining. Endometrial-peritoneal adhesion was evaluated using light microscopy. RESULTS: Endometrial-peritoneal adhesion was observed in approximately 80% of the adhesion assays and was not affected by the phase of the cycle, or by the presence and stage of endometriosis. The continuity of the mesothelial layer was disrupted at the attachment sites. Epithelialization was observed along the edges to integrate the endometrial implant. After adhesion, histological changes were observed within and below the implant. CONCLUSIONS: Endometrium obtained during menstrual, follicular or luteal phase appears to have a similar potential to implant in vitro on autologous peritoneum, and this adhesion process is not affected by the stage of endometriosis.     

Cytogenetics and molecular genetics of lung cancer

The development and progression of lung cancer is a multistep process characterized by the accumulation of numerous genetic and epigenetic alterations, some of which occur early in the course of disease. In this review, we summarize cytogenetic imbalances and molecular genetic/epigenetic changes seen in human small-cell and non-small-cell lung cancer. Alterations of tumor suppressor genes and oncogenes leading to perturbations of key cell-regulatory and growth-control pathways are highlighted. The translational implications of molecular biomarkers for risk assessment, early detection, and monitoring of chemoprevention trials are discussed.     

Blastic NK-cell lymphomas (agranular CD4+CD56+ hematodermic neoplasms): a review

Blastic natural killer (NK) cell lymphoma (also termed CD4+CD56+ hematodermic neoplasm) is a recently described entity, with the first case reported in 1994. It was suggested initially that the disease originates from NK cells. Since 1994, single cases and a few small series have been published. In this review, data from the literature and a series of 30 cases from the French and Dutch study groups on cutaneous lymphomas are discussed. The major clinical, histopathologic, and phenotypic aspects of the disease and diagnostic criteria and data suggesting a plasmacytoid dendritic cell origin for the tumor cells are provided.     

p53, Ki-67, and serum alpha feto-protein as predictors of hepatocellular carcinoma recurrence in liver transplant patients.

Patients with hepatocellular carcinoma who undergo orthotopic liver transplantation (OLT) are at risk for post-transplant tumor recurrence. The aim of this study was to evaluate whether expression of p53 and Ki-67 in hepatocellular carcinoma lesions present in explanted liver tissue was associated with time to tumor recurrence after OLT. Subjects consisted of 20 consecutive patients who underwent OLT and were found to have hepatocellular carcinoma in the liver explant. Immunostaining for p53 and Ki-67 was performed by standard methods. The presence of nuclear immunostaining in >10% of the tumor tissue was considered positive. Time to recurrence of hepatocellular carcinoma after OLT was compared between patients with positive and negative immunostaining by the log rank test. Multivariate analysis was performed using a Cox regression model to control for potentially confounding clinical factors. Time to post-transplant hepatocellular carcinoma recurrence was significantly more rapid in p53+ (P=0.0007) and Ki-67+ cases (P=0.001). These associations remained significant in multivariate analysis. Furthermore, time to recurrent hepatocellular carcinoma was significantly shorter in patients with a serum alpha feto-protein (AFP) level >or=100 ng/ml at time of diagnosis, compared to those with an AFP level <100 ng/ml (P=0.003). In conclusion, expression of p53 and Ki-67 in hepatocellular carcinoma lesions, and a serum AFP level >or=100 ng/ml were associated with more rapid recurrence of hepatocellular carcinoma after OLT. Identification of patients at risk for early post-transplant recurrence could be used to guide surveillance and adjuvant treatment strategies.     

Legionella pneumophila serogroup 1 strain Paris: endemic distribution throughout France

An analysis of 691 French clinical Legionella isolates showed that the endemic L. pneumophila serogroup 1 strain Paris was responsible for 12.2% of all cases of legionellosis and had a specific pulsed-field gel electrophoresis pattern. We also demonstrated the presence of this endemic clone throughout Europe.