Abdominal trans-sphincter resection of the anus: new possibilities in the surgical management of deep rectal cancer, with preservation of the anal sphincter

The last decade has brought marked changes in the surgical treatment of rectal cancer: as the indication of the sphincter-saving procedures was extended, the rate of the abdomino-perineal excision has decreased even in the case of tumours of the distal third of the rectum. However, even with the use of the modern stapling devices, the anterior resection and colo-anal anastomosis may not always be feasible by the traditional abdominal approach. In these cases the sphincter-saving resection can be performed by a particular approach, the abdomino-transsphincteric technique. The authors present this seldom used operation. From the 1-st of January 1994 to the 31-st of August 1996 14 abdomino-transsphincteric resections have been performed. The mean age of the patients was 62.2 (38-81) years. The lower edge of the tumours was situated at 6.3 (5-8) cm from the anal verge. The anastomosis was performed by the double stapling technique in 8 and by hand suture in 6 cases, its distance from the anal verge was 3.2 (3-4) cm. A colon J-pouch was used in 3 cases and a diverting colostomy was performed routinely. One patient died in the postoperative period and a reoperation (abdomino-perineal excission) was performed because of left colon necrosis: Anastomotic leakage was observed in one case. By the time of the present study, 11 patients have had their colostomies closed. The continence is acceptable in every case and all the patients experience a better subjective quality of life, than it was while wearing the colostomy. The use of this technique has helped to avoid a permanent colostomy in 21 out of 33 cases operated on for cancer of the distal rectal third in the reviewed period.     

The role of the carbonaceous overlayer in the competitive hydrogenation of cyclopropanes and olefins

In the competitive hydrogenation of olefin-cyclopropane mixtures (2-Me-2-butene + 1,1-diMe-cyclopropane and 2,4-diMe-2-pentene + 1,1,2,2-tetraMe-cyclopropane) over silica supported Pt, Pd and Rh catalysts at 318 K and 373 K, only the olefin is hydrogenated. The other component does not react even after the complete hydrogenation of the olefin. The olefin creates a hydrogen-rich carbonaceous overlayer which is the active phase for its hydrogenation but it is a permanent poison for the hydrogenative ring opening of the cyclopropane ring. On Ni/SiO₂ at 473 K, however, such an overlayer does not form and both reactants transform in parallel in a complex way.     

Decidable and undecidable logics with a binary modality

We give an overview of decidability results for modal logics having a binary modality. We put an emphasis on the demonstration of proof-techniques, and hope that this will also help in finding the borderlines between decidable and undecidable fragments of usual first-order logic.Research supported by the Hungarian National Foundation for Scientific Research grants no. T16448, F17452, T7255. Research of the first author is also supported by a grant of Logic Graduate School of Eötvös Loránd University Budapest     

Absorption and fluorescence spectroscopic study on complexation of Oxazine 1 Dye by calix[8]arenesulfonate

It has been established by combined absorption and fluorescence measurements that the cationic dye Oxazine 1 (OX) and the polyvalent anionic host calix[8]arenesulfonate (SCA8) form two complexes in simultaneous reactions: OX + SCA8 <--> OX.SCA8 (1), and OX.SCA8 + OX <--> OX(2).SCA8 (2). The equilibrium constants for the two reactions, as functions of the ionic strength (I), and the absorption and fluorescence spectra of the two complex species have been determined by a least-squares fitting method from the experimental data. The variations of the binding constants with the ionic strength could be described on the basis of Debye-Huckel theory. The equilibrium constants are large; their values extrapolated to I = 0 are K(1) = 5.5 x 10(6) M(-1) and K(2) = 4.4 x 10(5) M(-1). The fluorescence of OX undergoes a strong static quenching upon complexation. These results indicate that the complexes are held together by strong electrostatic forces. The addition of non-fluorescent tetramethylammonium chloride to OX-SCA8 mixtures results in a dramatic fluorescent enhancement, which demonstrates the potential applicability of this supramolecular system in fluorescence assays.     

Improving accessibility of CMS-based websites using automated methods

Universal Access in the Information Society - New methods of identifying and fixing accessibility issues on websites are presented in this article. The websites taken into consideration by the...     

Characterization of Biomimetic Cofactors According to Stability,Redox Potentials,and Enzymatic Conversion by NADH Oxidase from Lactobacillus pentosus

Oxidoreductases are attractive biocatalysts that convert achiral substrates into products of higher value, but they are also for the most part dependent on nicotinamide cofactors. Recently, biomimetic nicotinamide derivatives have received attention as less costly alternatives to natural cofactors. However, recycling of biomimetics is still challenging because there are only limited opportunities. Here, we have characterized various biomimetic cofactors with regard to stability and redox potentials to find the best alternative to natural cofactors. Further, the cofactor spectrum of NADH oxidase from Lactobacillus pentosus (LpNox) could be expanded, and the enzymatic activity was also compared to activities with different small‐molecule catalysts. As a result, we succeeded in identifying several strategies for regeneration of oxidized biomimetics.     

Factors influencing lake recovery from eutrophication--the case of basin 1 of Lake Balaton

Lake Balaton is a large, shallow, and calcareous lake that was subject to a rapid eutrophication during the 1970s. Management measures taken from the mid-1980s decreased the phosphorus load to the lake from 0.5 to 0.3 g P m-2 yr-1. Using long-term load and water quality data, we analyse the response of the formerly hypertrophic Basin 1 of the lake by the means of simple empirical models. Several factors that are commonly neglected during studies of lake recovery modified the apparent settling velocity of total P and consequently, the biomass of the phytoplankton. These factors included the loads of calcium and suspended solids, the loading ratio of the dissolved to particulate phosphorus, and blooming of the dominant cyanobacterium, Cylindrospermopsis raciborskii. Due to the rapid immobilisation of the mobile phosphorus in the surface sediments, moderate reduction (45-50%) in the external load resulted in a surprisingly fast and significant improvement of the water quality in the hypertrophic southwestern basins of the lake.     

Mild and neutral deprotections catalyzed by cerium(IV) ammonium nitrate

The development of a novel, chemoselective, and catalytic deprotection methodology that proceeds under mild and neutral conditions is described, and its mechanism of action is analyzed in some detail. The scope, limitations, and advantages of this protocol are discussed. Selected applications in synthesis are also highlighted.     

The Effect of Electroporation of a Lyotroic Liquid Crystal Genistein-Based Formulation in the Recovery of Murine Melanoma Lesions

A lamellar lyotropic liquid crystal genistein-based formulation (LLC-Gen) was prepared in order to increase the aqueous solubility of the lipophilic phytocompound genistein. The formulation was applied locally, in a murine model of melanoma, with or without electroporation. The results demonstrated that, when the formulation was applied by electroporation, the tumors appeared later. During the 21 days of the experiment, the LLC-Gen formulation decreased the tumor volume, the amount of melanin and the degree of erythema, but when electroporation was applied, all these parameters indicated a better prognosis even (lower tumor volume, amount of melanin and degree of erythema). Although hematoxylin–eosin (HE) staining confirmed the above events, application of the LLC-Gen formulation by electroporation did not lead to a significant effect in terms of the serum concentrations of the protein S100B and serum neuron specific enolase (NSE), or the tissue expression of the platelet-derived growth factor receptor β (PDGFRβ) antibody.