[DNA-protective potential of polyphenols in human mucosa cell cultures]. / DNA-protektives Potential von Polyphenolen in humanen Schleimhautzellkulturen.

BACKGROUND: The concept of field cancerization in the head and neck offers an excellent basis for chemopreventive interventions. Within the last few years, polyphenols, the most abundant phytochemicals in our diet, have been identified as interesting chemopreventive agents based on their multiple actions. This study was designed to add more experimental data regarding the chemopreventive features of epigallocatechin gallate (EGCG) and tannin (TA) in cultures of fresh biopsied tissue to epidemiologic studies and animal and cell line experiments. MATERIALS AND METHODS: Miniorgan cultures (MOC) were produced from oropharyngeal mucosa-cubes about 1 mm(3), epithelialized and with their tissue structure preserved. The MOC were incubated with EGCG (0.1 and 5 microM) and TA (1 and 5 microM) for 30 min on three consecutive days. On the 3rd day, DNA damage was introduced with metabolically activated tobacco carcinogen benzo[a]pyren-7,8-dihydrodiol-9,10-epoxid (BPDE) [9 microM] for 60 min. The resulting DNA damage was measured with alkaline single-cell microgel electrophoresis (comet assay) and quantified using the olive tail moment (OTM). RESULTS: By incubating MOC with the polyphenols, the DNA damage caused by BPDE was significantly decreased at all concentrations. CONCLUSION: To our knowledge, this is the first test using cell cultures produced from fresh biopsies that demonstrates ECGC and TA as promising chemopreventive agents and confirms nutritional studies.

Global trends in wind speed and wave height.

Studies of climate change typically consider measurements or predictions of temperature over extended periods of time. Climate, however, is much more than temperature. Over the oceans, changes in wind speed and the surface gravity waves generated by such winds play an important role. We used a 23-year database of calibrated and validated satellite altimeter measurements to investigate global changes in oceanic wind speed and wave height over this period. We find a general global trend of increasing values of wind speed and, to a lesser degree, wave height, over this period. The rate of increase is greater for extreme events as compared to the mean condition.

[Complement activation following head and brain trauma]. / Komplementaktivierung durch das Schädel-Hirn-Trauma (SHT).

The prognosis for a patient with a severe head injury is dependent not only upon the location and the degree of this trauma, but also upon additional complications. For example, disseminated intravascular coagulation (DIC) can occur because of the thromboplastic activity of the damaged brain tissue that enters the circulation. The complement (C) system is activated by certain enzymes that cleave the clotting factors. Therefore, after head injuries we searched for C activation because it could result in the adult respiratory distress syndrome (ARDS). Patients and methods. We had two groups of patients: (1) 23 with large destruction and (2) 13 with little destruction of the brain tissue. Eighteen patients in group 1 and 8 in group 2 had isolated brain trauma. Blood samples were taken--upon arrival at the hospital and then 1, 3, 7, 12, 24, and 48 h later; after that we took weekly blood samples up to the completion of their treatment in the intensive care unit. We measured the total hemolytic serum C activity (CH50), activation of alternative pathway hemolysis (APH50), cleavage products C3a and C3d, and total protein. Furthermore, we studied the coagulation parameters of the extrinsic (prothrombin time) and intrinsic (partial thromboplastin time) pathways and fibrinogen content. From the patients records we extracted clinical parameters such as neurological status, intracranial pressure, pathological details on computer tomography hemoglobin and arterial-alveolar oxygen difference. Results. Figure 1 shows the different reactions of the C system in both groups: while patients of group 1 suffered from a decrease in total and alternative hemolytic activity, the other group increases in both parameters.(ABSTRACT TRUNCATED AT 250 WORDS)

[Preservation of mucosal specimens before processing in the alkaline single cell microgel electrophoresis assay]. / Lagerung humaner nasaler Mukosa für die Einzelzell-Mikrogelelektrophorese.

BACKGROUND: Human mucosal biopsies are established in ecogenotoxicological studies, but up until now they have demanded immediate processing after harvesting. We report our experience with the preservation of specimens either for 24 h at 4 degrees C or for longer periods at -80 degrees C and compare the results with fresh specimens using the alkaline single cell microgel electrophoresis assay. PATIENTS AND METHODS: Nasal mucosa was harvested from ten patients, transferred to the laboratory and divided into groups for immediate processing,24 h preservation at 4 degrees C and cryopreservation at -80 degrees C. Alkaline single cell microgel electrophoresis assays were performed after separating the specimens into single cells and after exposure to benzo[a]pyrene,benzo[a]pyrene-diolepoxide, N-nitrosodiethylamine, or sodium dichromate. The trypan blue exclusion test was used to assess cytotoxicity. RESULTS: Despite of the fact that cell viability remained stable, after cryopreservation DNA-migration increased significantly for the negative control and benzo[a]pyrene. Although an increase was also seen for sodium dichromate, this was not significant. For benzo[a]pyrene-diolepoxide, N-nitrosodiethylamine and N-methyl-N'-nitro-N-nitrosoguanidine there were no significant changes in DNA-migration. After 24 h in cell medium at 4 degrees C,DNA-migration did not rise compared to the samples which were immediately processed. CONCLUSIONS: Preservation of mucosal specimens at 4 degrees C for 24 h may be legitimate in order to facilitate laboratory practice. However, cryopreservation should not be applied because it leads to higher rates of DNA migration in some tested substances in the alkaline single cell microgel electrophoresis assay.