Challenges in tissue engineering - towards cell control inside artificial scaffolds.

Control of living cells is vital for the survival of organisms. Each cell inside an organism is exposed to diverse external mechano-chemical cues, all coordinated in a spatio-temporal pattern triggering individual cell functions. This complex interplay between external chemical cues and mechanical 3D environments is translated into intracellular signaling loops. Here, we describe how external mechano-chemical cues control cell functions, especially cell migration, and influence intracellular information transport. In particular, this work focuses on the quantitative analysis of (1) intracellular vesicle transport to understand intracellular state changes in response to external cues, (2) cellular sensing of external chemotactic cues, and (3) the cells' ability to migrate in 3D structured environments, artificially fabricated to mimic the 3D environment of tissue in the human body.

p53, mdm2, EGFR, and msh2 expression in paired initial and recurrent glioblastoma multiforme.

BACKGROUND: The clinical course of glioblastoma multiforme is characterised by invasive growth and regular recurrence. Many genetic alteration have been identified in the genesis of the disease. However, information about immunohistochemical expression in recurrent lesions is sparse. OBJECTIVES: To determine (1) whether the p53/mdm2/EGFR/msh2 expression pattern differs in initial v recurrent glioblastoma multiforme; (2) whether a possible change in expression correlates with prognostic variables (progression-free survival time, total survival time); and (3) whether chemotherapy in addition to surgery and radiotherapy influences the p53/mdm2/EGFR/msh2 expression profile. METHODS: 27 patients were studied. They met the following criteria: histologically confirmed diagnosis of glioblastoma multiforme (WHO IV); total tumour resection at initial craniotomy; at least one re-craniotomy for glioblastoma multiforme recurrence; age 21 years or older. All underwent radiotherapy of at least 54 Gy, and 17 received additional chemotherapy. Immunohistochemical staining of initial tumours and recurrences was done with the following monoclonal antibodies: anti-p53 (DO-1), anti-mdm2 (IF-2), anti-EGFR (H11), and anti-msh2 (AB-1). RESULTS: In comparison with the initial tumour, recurrent lesions were characterised by reduced expression of p53 (p < 0.0001) and msh2 (p = 0.0012), while the numbers of mdm2 (p = 0.02), EGFR (p < 0.0001), and msh2 positive specimens (p < 0.0001) were reduced. Chemotherapy was associated with reduced msh2 expression (p < 0.0001). Immunohistochemical variables were not associated with patient survival. CONCLUSIONS: There are significant differences in the p53/mdm2/EGFR/msh2 expression patterns in initial v recurrent glioblastoma multiforme. There may be interactions between chemotherapy and changes in the msh2 expression.

Age-related expression of p53, Mdm2, EGFR and Msh2 in glioblastoma multiforme.

OBJECTIVE: Glioblastoma multiforme (GBM) is a major cause of morbidity and mortality in neurosurgical patients. Despite the overall poor prognosis a range in survival times exists. Many approaches have been undertaken to define patient subgroups based on molecular changes. The aim of this study was to assess a possible correlation between the immunohistochemical p53, Mdm2, EGFR and Msh2 expression and age. METHOD: 143 patients (77 male, 66 female) were included in this retrospective study who underwent craniotomy for newly-diagnosed GBM between May 1994 and February 2000. For statistical analysis, patients were separated into three age groups: 1. < 40 years, 2. 40-60 years, 3. > 60 years. Immunohistochemical staining (IHC) was performed using anti-p53 (clone DO-1), anti-Mdm2 (clone IF-2), anti-EGFR (clone H11) and anti-Msh2 antibodies (clone AB-1). The results were compared with the Ki67/MIB-1 proliferation index (Ki67 PI) and patient survival. FINDINGS: P53 protein expression was significantly decreasing with advanced age (p < 0.05) whereas EGFR and Mdm2 expression was increasing (p < 0.05; p=0.01). Msh2 expression was unrelated to age. Multivariate analysis revealed Msh2 protein expression as a significant predictor of prolonged survival (p=0.004) whereas p53, Mdm2 and EGFR were not associated with patient survival. P53, Mdm2, EGFR and Msh2 expression was not associated with the Ki67 PI. INTERPRETATION: Our results support the hypothesis that in GBM patients a complex relationship exists between the p53, Mdm2 and EGFR expression and age. Msh2 expression is not related to age. Notably, nuclear Msh2 expression turned out to be an independent prognostic indicator.

A cost estimation model for measuring professional practice.

A cost estimation model was developed to monitor the effect of an enhanced professional practice model on cost to the institution. The model detected differences across units and changes in unit activities. One unit's cost savings were greater than the others and this difference was believed to be related to stable leadership over the course of the study.

Analysis of ambulatory nursing practice.

A nursing patient classification system can be used in ambulatory care to facilitate decision making relative to staffing assignments and to begin examining differences in patients' nursing care requirements according to medical diagnosis or other patient characteristics.