[Current principles and approaches to the treatment for patients with locally advanced rectal cancer].

The short-term treatment results of 91 patients with locally advanced rectal cancer are presented. All patients received surgical treatment and neoadjuvant chemotherapy. The chemoradiotherapy effect was evaluated by comparison of pre- and post-therapeutic MRI data. MRI data was also compared with post-operation tumor morphology data. In 23% of resected tumor samples complete tumor regression was evident, in 47.2% of cases partial regression was revealed. Lymph node metastases were found in 21.9% of cases. The discrepancy in MRI and morphology data can be explained by the limited ability of MRI in differentiation between viable tumor, fibronecrotic tissue and inflammatory reaction after chemoradiotherapy.

[Clinical aspects of hereditary nonpolyposis colorectal cancer: experience of genetic consultation].

Five-ten percent of early-onset (up to age of 50) colorectal cancers are regarded as being inherited. Positive results of a medical genetic examination call for microsatellite instability test. However, that method is not absolutely reliable because although all microsatellite instability tests for hereditary nonpolyposis colorectal cancer are positive, microsatellite instability of tumor DNA occurs in 15% of sporadic colorectal carcinoma. Moreover, Russian diagnostic practices are peculiar in that "familial history" is often missed due to premature demise of relatives and lack of data. Under the circumstances, research should be focused on issues of still earlier onset of cancer as well as multifocal nature of tumor growth although similar manifestations may occur in sporadic cancer.

EPR spin probe study of polymer associative systems.

Molecular dynamics of polyacrylamide gels, polymeric micelles and hydrogel of polyacrylic acid and macrodiisocyanate was investigated by the ESR spectroscopy of spin probes. The local mobility in network junction of polyacrylamide gels is found to be essentially slower than that in the micelles created by the low molecular weight detergents and does not depend on the amount and length of hydrophobic groups (C9 or C12) in the polymer chain. The immersion of 10-30 mol.% of ionic monomers into the polymer chain (sodium acrylate) influences insufficiently on the local mobility of network junctions. In aqueous solutions, polystyrene-block-poly-(N-ethyl-4-vinylpyridinium bromide) block copolymers create polymeric micelles. The local mobility in the polystyrene core of the micelles is about twice as much as that in the solid polystyrene. Partially swellable polymer network in aqueous solutions was synthesized from polyacrylic acid and macrodiisocyanate. The local mobility in hydrophobic regions of the gel is substantially lower than that in the hydrophilic regions. It was concluded that the hydrophobic and hydrophilic regions and the local dynamics of them dictate practical application of the polymer associative systems.

Molecular organization and dynamics of micellar phase of polyelectrolyte-surfactant complexes: ESR spin probe study.

Molecular dynamics and organization of the micellar phase of complexes of linear polyelectrolytes with ionogenic and non-ionogenic surfactants was studied by the ESR spin probe method. Complexes of polyacrylic acid (PAA) and sodium polystyrenesulfonate (PSS) with alkyltrimethylammonium bromides (ATAB), as well as complexes of poly-N,N'-dimethyldiallylammonium chloride (PDACL) with sodium dodecylsulfate (SDS) were studied. The micellar phase of such complexes is highly organized molecular system, molecular ordering of which near the polymeric chain is much higher than in the 'center' of the micelle, it depends on the polymer-detergent interaction, flexibility of polymeric chain and length of carbonic part of the detergent molecule. Complexes of polymethacrylic acid (PMAA) with non-ionic detergent (dodecyl-substituted polyethyleneglycol), show that the local mobility of surfactant in such complexes is significantly lower than in 'free' micelles and depends on the number of micellar particles participating in formation of complexes.