On the dynamics of water molecules at the protein solute interfaces.

Proteins, with the large variety of chemical groups they present at their molecular surface, are a class of molecules which can be very informative on most of the possible solute-solvent interactions. Hen egg white lysozyme has been used as a probe to investigate the complex solvent dynamics occurring at the protein surface, by analysing the results obtained from Nuclear Magnetic Resonance, X-ray diffractometry and Molecular Dynamics simulations. A consistent overall picture for the dynamics of water molecules close to the protein is obtained, suggesting that a rapid exchange occurs, in a picosecond timescale, among all the possible hydration surface sites both in solution and the solid state, excluding the possibility that solvent molecules can form liquid-crystal-like supramolecular adducts, which have been proposed as a molecular basis of 'memory of water'.

[Prognostic value of quantitative DNA analysis, expressed in integrated optical density, in a series of 415 T1-T2, N0N1, M0 UICC breast cancers]. / Valeur pronostique du contenu en ADN, exprimé dans la densité optique intégrée, dans une série de 415 cancers du sein T1-T2, N0N1, M0 UICC.

From June 1982 to December 1992, 415 patients less than 75 years of age, without any previous or synchronous carcinoma, suffering from an invasive breast cancer classified as T1 (52.8%), T2 (47.2%), NO (65.1%) N1(34.9%), MO according to clinical TNM staging, were enrolled in this study. The median age was 53 (28-75), and 58.8% of the patients were menopaused; 85.3% underwent a breast conservative procedure and 14.7% a modified radical mastectomy followed by postoperative irradiation. Histological axillary lymph node status, Scarff-Bloom grade and/or cytological grade, estradiol receptor content, were used to set up medical adjuvant treatment: hormonotherapy (52%) or chemotherapy (18.8%). Imprints were taken from the macroscopically visible lesion at the time of surgery, and a Feulgen staining was done on air dried smears to be analyzed using the Samba 200 cell image processor (Alcatel TITN, France). Five parameters were systematically assessed: proliferation index, DNA histogram, integrated optical density, DNA malignancy grade, and policy balance. With a median follow-up of 36 months (0-105), proliferation index (P = 0.0008), DNA histogram (P = 0.0017), integrated optical density (P = 0.018), DNA malignancy grade (P = 0.017) have a significant prognostic value on disease free survival estimated by the Kaplan-Meir method. When these parameters were included in a Cox proportional regression hazards model, Scarff-Bloom histological grading (P = 0.002), positives nodes (P = 0.02), optical integrated density (P = 0.045) were significant. Such results need to be updated with a longer follow-up, but they suggest that the mean DNA content, as measured by the integrated optical density (IOD), has to be considered when deciding on medical adjuvant treatment with respect to patients with a negative axillary clearance.