Topical Application of 5-Fluorouracil for the Treatment of Sinonasal Adenocarcinoma and Inverted Papilloma.

Background: Sinonasal tumors represent a rare and heterogeneous group of rhinologic neoplasms. Even with advancements in surgical approaches, mortality rates of patients with sinonasal adenocarcinoma (SNAC) have not significantly improved and persistently high rates of recurrence in certain patients with inverted papilloma (IP) are seen. The use of 5-fluorouracil (5-FU) has been successfully described as an adjuvant treatment of SNAC and in the prevention of IP recurrence.

An assessment of the transport mechanism and intraneuronal stability of L-carnosine.

L-Carnosine (β-alanyl-L-histidine) is a well-known antioxidant and neuroprotector in various models on animals and cell cultures. However, while there is a plethora of data demonstrating its efficiency as a neuroprotector, there is a distinct lack of data regarding the mechanism of its take up by neurons. According to literature, cultures of rat astrocytes, SKPT cells and rat choroid plexus epithelial cells take up carnosine via the H-coupled PEPT2 membrane transporter.

Deuterated Arachidonic Acids Library for Regulation of Inflammation and Controlled Synthesis of Eicosanoids: An In Vitro Study.

The synthesis of signal lipids, including eicosanoids, is not fully understood, although it is key to the modulation of various inflammatory states. Recently, isotopologues of essential polyunsaturated fatty acids (PUFAs) deuterated at bis-allylic positions (D-PUFAs) have been proposed as inhibitors of non-enzymatic lipid peroxidation (LPO) in various disease models. Arachidonic acid (AA, 20:4 n-6) is the main precursor to several classes of eicosanoids, which are produced by cyclooxygenases (COX) and lipoxygenases (LOX).

Physicochemical and functional properties of Cucurbita maxima pumpkin pectin and commercial citrus and apple pectins: A comparative evaluation.

The physicochemical characteristics and functional properties of pumpkin (Cucurbita maxima D. var. Cabello de Ángel) pectin obtained by cavitation facilitated extraction from pumpkin pulp have been evaluated and compared with commercial citrus and apple pectins.

Comparative Action of Cardiotonic Steroids on Intracellular Processes in Rat Cortical Neurons.

Binding to Na+,K+-ATPase, cardiotonic steroids (CTS) activate intracellular signaling cascades that affect gene expression and regulation of proliferation and apoptosis in cells. Ouabain is the main CTS used for studying these processes. The effects of other CTS on nervous tissue are practically uncharacterized.

Negative Cooperativity in the Interaction of Prostaglandin H Synthase-1 with the Competitive Inhibitor Naproxen Can Be Described as the Interaction of a Non-competitive Inhibitor with Heterogeneous Enzyme Preparation.

The kinetic mechanism of the interaction of nonsteroidal anti-inflammatory drugs (NSAIDs) with their main pharmacological target, prostaglandin H synthase (PGHS), has not yet been established. We showed that inhibition of PGHS-1 from sheep vesicular glands by naproxen (a representative of NSAIDs) demonstrates a non-competitive character with respect to arachidonic acid and cannot be described within a framework of the commonly used kinetic schemes. However, it can be described by taking into account the negative cooperativity of naproxen binding to the cyclooxygenase active sites of the PGHS-1 homodimer (the first naproxen molecule forms a more stable complex (K = 0.

Prostaglandin H synthase kinetics in the two-phase aqueous-micellar system.

Reaction mixture for PGHS (prostaglandin-H-synthase) is a two-phase system including micellar hydrophobic phase and hydrophilic aqueous phase. Reagents added to the mixture are distributed between phases, thus concentrations of reagents dissolved in phases can differ significantly from their overall contents. Using dynamic light scattering we found that the hydrophobic phase produced by tween-20 consists of micelles, which radius (4-5nm) does not depend on either tween-20 overall content (0.

[Cleavage of DNA fragments induced by UV nanosecond laser excitation at 193 nm].

The cleavage of dsDNA fragments in aqueous solution after irradiation with UV laser pulses at 193 nm has been studied. Samples were investigated using polyacrylamide gel electrophoresis. The intensity of damage of particular phosphodiester bond after hot alkali treatment was shown to depend on the base pair sequence.

Inhibition of cyclooxygenase activity of prostaglandin-H-synthase by excess substrate (molecular oxygen).

For the cyclooxygenase reaction of prostaglandin-H-synthase isolated from ram vesicular glands, dependences of the initial reaction rate, the maximal yield of the product, and the rate constant of enzyme inactivation in the course of reaction on oxygen concentration were studied in the absence and in the presence of electron donor in the reaction medium. It is shown that in the absence of electron donor the cyclooxygenase reaction is strictly governed by Michaelis-Menten kinetics over a wide range of oxygen concentrations (5-800 µM). In the presence of electron donor in the reaction medium it was found that cyclooxygenase reaction is inhibited by an excess of dissolved oxygen: the maximal values of the initial reaction rate and yield of the product are attained at oxygen concentration 50 µM, and its increase to 500 µM causes twofold decrease in the initial rate and maximal yield.

[Risk factors for recurrent inguinal hernia].

Plasty of the anterior wall of the inguinal canal during herniotomy is considered the main risk factor for recurrent inguinal hernia. Plasty of the posterior wall of the inguinal canal for oblique inguinal hernia is simultaneously a prophylactic measure to prevent the development of direct inguinal hernia in future. 5 types of relapses are defined depending on the localization, tactical and technical mistakes during herniotomy.

Molecular oxygen (a substrate of the cyclooxygenase reaction) in the kinetic mechanism of the bifunctional enzyme prostaglandin-H-synthase.

Prostaglandin-H-synthase is a bifunctional enzyme catalyzing conversion of arachidonic acid into prostaglandin H2 as a result of cyclooxygenase and peroxidase reactions. The dependence of the rate of the cyclooxygenase reaction on oxygen concentration in the absence and in the presence of electron donor was determined. A two-dimensional kinetic scheme accounting for independent proceeding and mutual influence of the cyclooxygenase and peroxidase reactions and also for hierarchy of the rates of these reactions was used as a model.

Kinetic mechanism of the bifunctional enzyme prostaglandin-H-synthase. Effect of electron donors on the cyclooxygenase reaction.

Prostaglandin-H-synthase (PGHS, EC 1.14.99.

Observation of a narrow charm-strange meson D(+)(sJ)(2632)-->D(+)(s)eta and D(0)K(+).

We report the first observation of a charm-strange meson D(+)(sJ)(2632) at a mass of 2632.5+/-1.7 MeV/c(2) in data from SELEX, the charm hadro-production experiment E781 at Fermilab.

First observation of the doubly charmed baryon Xi(+)(cc).

We observe a signal for the doubly charmed baryon Xi(+)(cc) in the charged decay mode Xi(+)(cc)-->Lambda(+)(c)K-pi(+) in data from SELEX, the charm hadroproduction experiment at Fermilab. We observe an excess of 15.9 events over an expected background of 6.

Precision measurements of the lambda(+)(c) and D0 lifetimes.

We report new precision measurements of the lifetimes of the Lambda(+)(c) and D0 from SELEX, the charm hadroproduction experiment at Fermilab. Based upon 1630 Lambda(+)(c) and 10 210 D0 decays we observe lifetimes of tau[Lambda(+)(c)] = 198.1+/-7.

Observation of the Cabibbo-Suppressed Decay Ξ_{c}^{+} → pK^{-}π^{+}.

We report the first observation of the Cabibbo-suppressed charm baryon decay Ξ_{c}^{+}→pK^{-}π^{+}. We observe 150±22±5 events for the signal. The data were accumulated using the SELEX spectrometer during the 1996-1997 fixed target run at Fermilab, chiefly from a 600 GeV/c Σ^{-} beam.

[The microbiocenosis of the large intestine in animals with constant radiation exposure in the area of the Chernobyl Atomic Electric Power Station].

State of microbiocenosis of large intestine in rats and furo subjected to constant combined irradiation has been studied in full-scale experiments in the emergency rooms of the Chernobyl NPP and in the nearest zone of its effect. The higher diversity of microflora (as compared to initial one), sharp increase of the amount of Candida genus fungi, a decrease of the number of bifidobacteria and increase of the amount of conditionally pathogenic flora were observed in rats with the dose of external irradiation of 1.43 Gr absorbed for 14 days.

[Radionuclide transfer by migratory birds].

Evaluation of the zoogenic transfer of radionuclides from the 30-km zone around the Chernobyl NPP was necessary because of the enormous heavily polluted territory and mighty flow of migratory birds who tended to large rivers, the Dnieper and Pripyat. The integral estimate of the transferred amount was obtained as a product of three variables: the transfer factor (0.0077 m2/kg for 137Cs; 0.

[Heterophilic granulocytes of rats during irradiation].

The bone marrow eosinophils of rats subjected to irradiation are capable of secreting a peroxidase system obtained by neutrophils and endotheliocytes. As a result, there appear heterophil granulocytes in the peripheral blood.

Coupling of peptides to protein carriers by mixed anhydride procedure.

Carboxyl groups of succinylated bovine serum albumin were activated by isobutylchloroformate in dimethylformamide solution. Subsequent reaction of the mixed anhydride with amino groups of the added peptide provided rapid and efficient coupling of peptide to protein. For different peptides the yield of coupling was equal to 40-100%.