Decomposition of leaf litter in the Brazilian savanna on limestone and sandstone Neosols.

Litter decomposition in the soil is an important stage of the nutrient cycling process that interferes with functioning of terrestrial ecosystems. Soil fertility and litter nutritional quality are fundamental factors that affect decomposition efficiency of plant residues. We evaluated decomposition in two areas of 'cerrado sensu stricto', each with a type of Neosol - limestone (eutrophic) and sandstone (dystrophic). In a rural area located in the municipality of Ituiutaba (MG, Brazil), 10 plots were randomly selected to install litter bags with 10 g of mixture of dry leaves that were used to estimate rate and time of leaf-litter decomposition from October/2015 to January/2016. Decomposition rate in the limestone cerrado was significantly higher than in the sandstone cerrado. This difference mustn't be explained by the edaphic texture between areas, since it was similar between them. But may be explained through aluminum absence and higher soil fertility in the limestone cerrado, especially phosphorus that is highly limiting in dystrophic cerrados like the sandstone cerrados, in which decay of decomposing leaf-litter was directly proportional to the levels of phosphorus. Limestone presence reduces aluminum toxicity and circumvent phosphorus limitation in the cerrado, favoring decomposition. Such influence is probably an important feature for limestone cerrados.

Virus Reduction Neutralization Test: A Single-Cell Imaging High-Throughput Virus Neutralization Assay for Dengue.

Vaccine immunogenicity and clinical efficacy are often assessed by the measure of serum-neutralizing antibodies. The present gold standard for detecting neutralizing antibodies against many viruses, including dengue, is the plaque/focus reduction neutralization test (P/FRNT). The FRNT is a cell-based assay that inherits high variability, resulting in poor precision and has lengthy turnaround times. The virus reduction neutralization test (VRNT) is a high-throughput alternative to the standard low-throughput and laborious FRNT. The VRNT is similar to FRNT using unaltered wild-type virus and immunostaining, yet uses imaging cytometry to count virus-infected cells 1 day post-infection, reducing assay time and increasing overall throughput 15-fold. In addition, the VRNT has lowered variability relative to FRNT, which may be explained in part by the observation that foci overlap alters foci count and titer over time, in the FRNT. The ability to count one infected cell, rather than waiting for overlapping foci to form, ensures accuracy and contributes to the precision (7-25% coefficient of variation) and sensitivity of the VRNT. Results from 81 clinical samples tested in the VRNT and FRNT show a clear positive relationship. During sample testing, a 96-well plate edge effect was noted and the elimination of this edge effect was achieved by a simple plate seeding technique. The VRNT is an improvement to the current neutralization assays for its shortened assay time, increased precision and throughput, and an alternative to the P/FRNT.

Pathway Distribution Model for Solute Transport in Stratum Corneum.

One of the main functions of the skin is to reduce the amount of water evaporating from the surface of a human body with outermost layer of the epidermis, stratum corneum (SC), forming a barrier, which protects underlying tissue from dehydration. Empirical data obtained for water penetration in SC are normally analysed using mathematical models, among which the homogeneous membrane (HM) model is commonly employed to describe transport kinetics in SC. However, the HM model failed to fit simultaneously the experimental data for water permeation and desorption (Anissimov YG, Roberts MS. 2009. J Pharm Sci 98:772-781), as the model does not account for a complex structure of SC and irregular distribution of corneocytes. Our previous work (Anissimov YG, Roberts MS. 2009. J Pharm Sci 98:772-781) introduced a slow binding (SB) model that is more aligned with the true biological structure of SC. This report provides an alternative/additional model to both the HM and SB models and takes into account the distribution of effective pathways across SC for water transport.

Original method for nicorandil synthesis.

Nicorandil (N-(2-hydroxy-ethyl)-nicotine amide nitrate), drug recently introduced in therapy, is used as a vasodilator through potassium channel activation. Nicorandil is obtained by treating nicotinic acid chloride hydrochloride with nitro-oxy-ethyl-amine nitrate in an organic solvent. The authors suggest a method that uses ethyl nicotinate as raw material. Thus, the drug can be obtained from indigenous raw materials, at a lower price than the imported ones, with a high purity and a good yield.

Poly(vinylbenzyl chloride) microsphere synthesis and their chemical modifications.

Vinylbenzyl chloride (VBC) was dispersion polymerized to give monodisperse microspheres in the presence of poly(vinylpyrrolidone) (PVP) as a steric stabilizer. The effect of PVP concentration on the size and on microsphere stability during the polymerization process was investigated. Microsphere size was examined when co-stabilizer molecules were employed with PVP during the polymerization reaction. The built-in reactive chloromethyl groups of the microspheres were the sites of the nucleophilic reaction of two amino-group model molecules, glucosamine (G), a hexosamine implicated in processes of molecular recognition, and also bovine serum albumin (BSA). Elemental analyses and Fourier transform infrared spectroscopy (FTIR) spectra showed that poly(vinylpyrrolidone) was associated with the microsphere network. Elemental analyses, attenuated total reflection infrared spectroscopy (ATR-FTIR), and zeta potential measurements confirmed G and BSA links at the microsphere surface.

[Researches on pharmacological properties of some new xanthine derivatives]. / Cercetari privind actiunea bronhodilatatoare a unor noi compusi xantinici.

We studied the potentially bronhodilatatory action of some new xanthine compounds, theophylline derivatives with 7-[2-hydroxy-3-(4-acetamido)-phenoxy-propyl]-8-R-1,3-dimethyl-xanthine and 8-R-1,3-bis-(1,3-dimethyl-xanthin-7yl)-2-hydroxy-propane structure substituted in 7 and 8 position. The tracheal smooth muscle contraction we realized by carbachol (10(-5) M) or potassium chloride (40 mM), the xanthine compound being much active on the contraction induced by carbachol. We observed that the modification realised in theophylline structure determined the modification of bronchodilatatory properties. The bronchodilatatory effect of theophylline intensified with the introduction in 7 position the 2-hydroxy-3-(acetamido)-phenoxy-propyl and in 8 position the bromo, nitro, piperidinyl and imidazolyl radicals.

[Fluoroquinolones. Drug interactions]. / Fluorochinolonele. Interactiuni medicamentoase.

This review summarizes clinically relevant drug-drug interactions for fluoroquinolones: antiacids containing aluminum and magnesium salts, iron or zinc preparations, sucralfate, cimetidine, ranitidine, warfarina, cyclosporin, rifampin, oral contraceptive steroids, benzodiazepine, probenecid, beta-lactam antibiotics, nonsteroidal anti-inflammatory drugs, metronidazole, theophylline, caffeine.

[Multiparticulate systems in the controlled release of active substances in the gastrointestinal tract]. / Sisteme multiparticulare pentru eliberare controlata a substantelor active în tractusul gastrointestinal.

The design of multiparticulate systems as carriers for molecules that have to be delivered at specific sites of the gastrointestinal tract must take into account the common events that govern this region. The intrusion of the multiparticulate systems has to face, by meanings of synthesis methods, or only by lack of aggressiveness the host system defences. Thus, non-specific and specific defence mechanisms are deployed to deal with the intruding material. Several strategies can be mentioned, as (a) prevent the contact and remove if contacted (b) kill if not remove, by the micro-fold cells that engulf bacteria and the gastrointestinal-associated lymphoid tissue. A physical barrier that adheres, prevents the contact, en-traps and removes the foreign matter is the mucus produced by the goblet cells.

[Vanadium derivatives--a new source of antidiabetic drugs]. / Derivatii de vanadiu--o noua sursa de medicamente antidiabetice.

Vanadium, a transitional element belonging to Vb group is wide-spread both in vegetal and animal world. Although known by more a hundred years ago only in 1985 its hypoglycaemic properties were established. Recent research shown that the hypoglycaemic properties and the toxicity are influenced both by vanadium valence state and organic moiety that is binding it.

[The production of nitro esters active at the level of the cardiovascular system]. / Cercetari privind obtinerea unor nitroesteri activi la nivelul aparatului cardiovascular.

In order to obtain new compounds with cardiovascular activity, some esters of nitric acid with ethanolamine were synthesised, using some aromatic acids, acexamic acid, the natural methylxanthines-theophylline and theobromine. The melting points, yields and solubility of the new compounds were determined, and the chemical structures were confirmed by elemental analysis C, H, N, and by spectral analysis in KBr.

Direct detection of the antioxidant activity of a new flavonic derivative using the chemiluminescence method.

The antioxidant potential of a new water soluble flavonic derivative, namely theophylline rutoside (TR-1722) has been tested using the chemiluminescence method. The method is based on the oxidative degradation of luminol by the hydrogen peroxide in Tris-HCl-buffer, when reactive species of oxygen are being obtained: O2-., HO., 1O2, and allows for the capability of substances to inhibit the free radical processes in this test system to be quantified and hence for their antioxidant properties in respect to a standard substance (in our case quercetin) to be compared. The results obtained reveal that TR-1722 has antioxidant action comparable to that of quercetin, the highest efficacity being registered at the concentration of 2 mumol/l, the conditions being: H2O2 16,2 mmol/l; luminol 2 mumol/l, in Tris-HCl buffer 20 mmol/l, pH 8.3. The antioxidant potential of TR-1722 is also maintained when the conditions of the system are modified, that is, the concentration of the hydrogen peroxide, the intensity of the action being dependent on the hydrogen peroxide concentration, but no direct proportionality is registered.

Antioxidant action of a new flavonic derivative in acute carbon tetrachloride intoxication.

The antioxidant potential of a new flavonic derivative named conventionally theophylline-rutoside [TR-1722] was estimated by the measurement of G-6-Pase activity (marker enzyme for the endoplasmic reticulum), catalase activity (enzyme involved in the antioxidant defence process), and total -SH groups from the hepatic homogenate, using CCl4 as a free radical generating model. To show changes in the permeability of the hepatocyte membrane, the activity of lactate dehydrogenase (LDH) in plasma was determined. The obtained results suggest that TR-1722 acts by curtailing both lipid peroxidation and alkylation processes.

[Benzimidazole derivatives with antihypertensive and platelet antiaggregant actions]. / Derivati ai benzimidazolului cu actiune antihipertensiva si antiagregant-plachetara.

The changing of the chemical structure of 2-benzylbenzimidazole, the active substance of Dibazol (Tromesedan), generated five analogous structures. Two salts of the same active substance have been synthesized in view of improving some of the pharmacological and toxicological features. The results of the anti-AHT and platelet aggregation actions are also presented.

[Analytical study of theophylline-rutozide (TR-1722)]. / Studiu analitic al teofilin-rutozidei (TR-1722).

A compound obtained by the semisynthesis of theophylline and rutozid was analysed elementary and physicochemically. The performed analyses showed that it was 7-rutozidil-is-propanolen-theophylline.

[Methodology for quality control of an ointment with antivaricose properties]. / Metodologie de control pentru un unguent cu proprietati antivaricoase.

A personal formulation of an ointment with antivaricose properties is presented. A methodology for the physicochemical and rheologic control, including all parameters required by the standards for ointments quality control, was designed. The analyses showed that the ointment is stable in time, has a thixotropic consistency and behaviour and does not require special preservation conditions.

[The physicochemical characterization and therapeutic evaluation of Cicatrol]. / Caracterizarea fizico-chimica si evaluarea terapeutica a produsului Cicatrol.

Cicatrol ointment with the formula: argentic sulphamethoxydiasine 1 g, bentonite hydrogel 12.5% for 100 g is manufactured at the Microproduction Laboratory of the Faculty of Pharmacy of Iasi. The one-year physicochemical determinations of the aspect, colour, homogeneity, pH, rheological behaviour and relative viscosity, content in argentic sulphamethoxydiasine as well as "in vitro" antimicrobial activity of Cicatrol showed a good stability and gel properties enabling an uniform and long-term contact with the wound. The clinical investigations carried out until now in patients with burns, varicose ulcers, trophic shank ulcers, superficial phlebitis with atonic ulcerations or wounds with multiple sites revealed its remarkable therapeutic value. As compared to other similar products, Cicatrol by its aseptic properties favours the scarring of any type of wound, a normal skin, without keloid scars being obtained, it also being well tolerated.