Contributions of Albert Einstein to Earth Sciences: A review in Commemoration of the World Year of Physics

The World Year of Physics (2005) is an international celebration to commemorate the one hundredth anniversary of Einstein's "Annus Mirabilis". The United Nations has officially declared 2005 the International Year of Physics. However, the impact of Einstein's ideas was not restricted to physics. Among numerous other disciplines, Einstein also made significant and specific contributions to Earth Sciences. His geosciences-related letters, comments, and scientific articles, are dispersed, not easily accesible and are poorly known. The present review attempts to integrate them, as a tribute to Einstein in commemoration of this centenary. These contributions can be classified into three basic areas: geodynamics, geological (planetary) catastrophism and fluvial geomorphology.Comment: 17 pages, no figures, to be published in Naturwissenschafte

Geriatric oncology: comparing health related quality of life in head and neck cancer patients

Background: Population ageing is increasing the number of people annually diagnosed with cancer worldwide, once most types of tumours are age-dependent. High-quality healthcare in geriatric oncology requires a multimodal approach and should take into account stratified patient outcomes based on factors other than chronological age in order to develop interventions able to optimize oncology care. This study aims to evaluate the Health Related Quality of Life in head and neck cancer patients and compare the scores in geriatric and younger patients. Methods. Two hundred and eighty nine head and neck cancer patients from the Oncology Portuguese Institute participated in the Health Related Quality of Life assessment. Two patient groups were considered: the geriatric ( 65 years old, n = 115) and the younger (45-60 years old, n= 174). The EORTC QLQ-C30 and EORTC QLQ-H&N35 questionnaires were used. Results: Head and neck cancer patients were mostly males, 77.4% within geriatric group and 91.4% among younger patients group. The most frequent tumour locations were similar in both groups: larynx, oral cavity and oropharynx - base of the tongue. At the time of diagnosis, most of younger male patients were at disease stage III/IV (55.9%) whereas the majority of younger female patients were at disease stage I/II (83.4%). The geriatric patient distribution was found to be similar in any of the four disease stages and no gender differences were observed. We found that age (geriatrics scored generally worse), gender (females scored generally worse), and tumour site (larynx tumours denounce more significant problems between age groups) clearly influences Health Related Quality of Life perceptions. Conclusions: Geriatric oncology assessments signalize age-independent indicators that might guide oncologic geriatric care optimization. Decision-making in geriatric oncology must be based on tumour characteristics and chronological age but also on performance status evaluation, co-morbidity, and patient reported outcomes assessment.info:eu-repo/semantics/publishedVersio

Neuroinflammatory signals enhance the immunomodulatory and neuroprotective properties of multipotent adult progenitor cells

Introduction: Stem cell-based therapies are currently widely explored as a tool to treat neuroimmune diseases. MAPC (Multipotent Adult Progenitor Cells) have been suggested to have strong immunomodulatory and neuroprotective properties in several experimental models. In this study, we investigate whether MAPC are of therapeutic interest for neuroinflammatory disorders such as multiple sclerosis (MS), by evaluating their capacities to modulate crucial pathological features and gain insights in the molecular pathways involved. Methods: Rat MAPC (rMAPC) were treated with combinations of pro-inflammatory cytokines that are closely associated with neuroinflammatory conditions, a process called licensing. mRNA expression of immunomodulatory molecules, chemokines and chemokine receptors was investigated. The migratory potential of licensed rMAPC towards a broad spectrum of chemokines was tested in a Transwell assay. Furthermore, the effect of licensing on the ability of rMAPC to attract and suppress the proliferation of encephalitogenic T cells was assessed. Finally, neuroprotective properties of rMAPC were determined in the context of protection from oxidative stress of oligodendrocytes. Therefore, rMAPC were incubated with conditioned medium of OLN93 cells subjected to sub-lethal doses of hydrogen peroxide (H2O2) and the gene expression of neurotrophic factors was assessed. Results: After licensing, a wide variety of immunomodulatory molecules and chemokines, including Nitric Oxide synthase (iNOS) and fractalkine, was up-regulated by rMAPC. The migratory properties of rMAPC towards various chemokines were also altered. In addition, rMAPC were found to inhibit antigen specific T cell proliferation and this suppressive effect was further enhanced after pro-inflammatory treatment. This phenomenon was partially mediated through iNOS or cyclooxygenase-2 (COX-2). Activated rMAPC secreted factors that led to attraction of myelin specific T cells. Finally, exposure of rMAPC to in vitro simulated neurodegenerative environment induced the up-regulation of mRNA levels of vascular endothelial growth factor (VEGF) and ciliary neurotrophic factor (CNTF). Factors secreted by rMAPC in response to this environment partially protected OLN93 cells from H2O2 induced cell death. Conclusions: rMAPC possess immune modulatory and neuroprotective properties which are enhanced in response to neuroinflammatory signals. These findings thereby warrant further research to evaluate MAPC transplantation as a therapeutic approach in diseases with an immunological and neurodegenerative component such as MS.The authors would like to thank Ms. Katrien Wauterickx, Ms. Christel Bocken and Mr. Jo Janssen (Hasselt University, Biomedical Research institute) for overall technical assistance. Additionally, we gratefully thank Ms. Ellen Van Houtven (ReGenesys) for her assistance in designing the migration assays. This research was supported by the Belgian Charcot Foundation

Assessment of cytological atypia, AgNOR and nuclear area in epithelial cells of normal oral mucosa exposed to toombak and smoking

The purpose of this study was to assess cellular proliferative activity of clinically healthy oral mucosal epithelial cells of toombak dippers and smokers by means of AgNOR counts and nuclear areas via nuclear morphometry. Smears were collected from normal-appearing mouth floor mucosa and tongue of 75 toombak dippers, 75 smokers and 50 non-tobacco users between the ages of 20 and 70 with a mean age of 36 years. AgNORs were counted in the first 50 well-fixed, nucleated squamous cells and nuclear areas were calculated via microscopic stage micrometer. Cytological atypia was ascertained in 6 tobacco users and could not be ascertained in non-tobacco users. Statistically mean AgNOR numbers per nucleus in the non-tobacco users (2.45±0.30) was lower than the toombak dippers (3.081±0.39, p lower than 0.004), and the smokers (2.715±0.39, p lower than 0.02), and mean nuclear areas of epithelial cells of toombak dippers (6.081±0.39, p lower than 0.009) and smokers (5.68±10.08, p lower than 0.01) was also significantly higher than non-smokers (5.39±9.4). The mean number of nuclei having more than 3 AgNORs was 28%, 19% and 7% in toombak dippers, smokers and non-tobacco users, respectively. These findings support the view that toombak dipping and smoking are severe risk factors for oral mucosal proliferative lesions and exfoliative cytology is valid for screening of oral mucosal lesions