Morphological and virological studies in six autopsies of children with adenovirus pneumonia

Pulmonary lesions compatible with adenovirus infection were detected by gross and microscopic examination of autopsy tissues children aged from 5 to 34 months. Hepatic lesions indicative of systemic infection were also found in four of the chisldren. The viral etiology was confirmed in three cases by in-situ hibridization, electro-microscopy and immunofluorescence performed in parafin-embedded tissues, and in one case by cell culture isolation of adenovirus type 2 from nasopharyngeal exudate. Routine testing by methods additional to conventional light microscopy would probably have revealed a larger number of adenovirus infections among the 1.103 autopsy records analyzed in this study.

Low occurrence of arthritic manifestations in patients with pulmonary tuberculosis: T cell subsets and humoral studies

Given the suspected role of mycobacteria in the establishment of disorders with an autoimmune background and joint damage, a study was conducted to analize whether rheumatic symptoms were likely to be present in tuberculosis (TB) patients. To this end, 330 patients with a bacteriologic confirmation of tuberculosis were investigated for the presence of arthritic complaints. The latter were recorded in five of them with rheumatic symptoms mostly involving interphalangeal and metacarpophalanged joints, and preceding the clinical manifestations of the TB illness. Three out of these five patients remained arthritic by the time of the bacteriologic conversion and fulfilled the criteria for the diagnosis of rheumatoid arthritis. In the two remaining patients sputum negativization was accompanied by a disappearance of rheumatic manifestations. These patients were also assessed for their peripheral levels of major T cell subsets as well as for the presence of autoantibodies. Comparisons with a series of non-arthritic TB cases, rheumatoid arthritis patients, and controls revealed that presence of rheumatic manifestations was associated with a different profile of autoantibody formation and T cell subset changes. Evidence recorded in the present study indicates that joint affectation in TB is a rare event, being rather the exception than the rule.

Chagas disease: serological and electrocardiographic studies in Wichi and Creole communities of Misión Nueva Pompeya, Chaco, Argentina

Chagas disease, which is caused by Trypanosoma cruzi, affects nearly 16 million people in Latin America and causes 75-90 million people to be at risk of infection. The disease is urbanizing and globalizing due to frequent migrations. There are regions of high prevalence of infection, including the north-eastern provinces of Argentina and the entire phytogeographic region known as the Gran Chaco. In the province of Chaco, Argentina, there are places inhabited by native populations such as the Wichi and Toba communities, among others. Many Creole populations resulting from miscegenation with European colonists and immigrants coexist within these communities. It has been widely accepted that in the chronic phase of the disease, between 25-30% of individuals develop some form of cardiac disease, with the right bundle-branch block being the most typical condition described so far. The aim of this work was to study the prevalence of Chagas infection and its electrocardiographic profile in the Wichi and Creole populations of Misión Nueva Pompeya, in the area known as Monte Impenetrable in Chaco, to determine the prevalence and the pattern of heart diseases produced by Chagas disease in this region.

New host, geographic records, and histopathologic studies ofAngiostrongylus spp (Nematoda: Angiostrongylidae) in rodents from Argentina with updated summary of records from rodent hosts and host specificity assessment

To date, 21 species of the genus Angiostrongylus (Nematoda: Angiostrongylidae) have been reported around the world, 15 of which are parasites of rodents. In this study, new host, geographic records, and histopathologic studies of Angiostrongylus spp in sigmodontine rodents from Argentina, with an updated summary of records from rodent hosts and host specificity assessment, are provided. Records of Angiostrongylus costaricensis from Akodon montensis andAngiostrongylus morerai from six new hosts and geographical localities in Argentina are reported. The gross and histopathologic changes in the lungs of the host species due to angiostrongylosis are described. Published records of the genus Angiostrongylus from rodents and patterns of host specificity are presented. Individual Angiostrongylusspecies parasitise between one-19 different host species. The most frequent values of the specificity index (STD) were between 1-5.97. The elevated number of host species (n = 7) of A. morerai with a STD = 1.86 is a reflection of multiple systematic studies of parasites from sigmodontine rodents in the area of Cuenca del Plata, Argentina, showing that an increase in sampling effort can result in new findings. The combination of low host specificity and a wide geographic distribution of Angiostrongylus spp indicates a troubling epidemiological scenario although, as yet, no human cases have been reported.

Effect of metal ions on the in vitro availability of enoxacin, its in vivo implications, kinetic and antibacterial studies

The present paper describes the effect of metals ions on the in vitro availability of enoxacin (a second generation quinolone antibiotic) owing to drug-metal interaction. These interaction studies were performed at 37 °C in different pH environments simulating human body compartments and were studied by UV spectroscopic technique. In order to determine the probability of these reactions different kinetic parameters (dissolution constants (K) and free energy change (ΔG)) for these reactions were also calculated. It is proposed that the structure of enoxacin contains various electron donating sites which facilitate its binding with metallic cations forming chelates. Hence taking food products, nutritional supplements or multivitamins containing multivalent cations at the same time as enoxacin, could reduce the absorption of the drug into the circulation and thus would decrease the effectiveness of the drug. In addition, the MIC of enoxacin for various microorganisms before and after interaction with metal ions was calculated which in most cases was increased which possibly could impair the clinical efficacy of the drug.

Simvastatin assay and dissolution studies by feasible RP-HPLC in tablets

Commonly used HPLC acetonitrile solvent has been through a worldwide shortage with a cost increase in 2008 and 2009. In order to get around this situation, a method by RP-HPLC employing methanol and aqueous acid mobile phase was developed and validated to evaluate simvastatin. The quality control assay and dissolution studies of this lipid-lowering drug were performed in diluents methanol and 0.01 M phosphate buffer with 0.5% SDS, pH 7, respectively. Dissolution test aliquots did not go through sample treatment, as described in USP SIM tablets monograph by ultraviolet spectrophotometry. The proposed method is fast, simple, feasible and robust.

Synthesis, characterization and computational studies of (E)-2-{[(2-aminopyridin-3-yl)imino]-methyl}-4,6-di-tert-butylphenol

(E)-2-{[(2-Aminopyridin-3-yl)imino]-methyl}-4,6-di-tert-butyl-phenol ( 3: ), a ligand containing an intramolecular hydrogen bond, was prepared according to a previous literature report, with modifications, and was characterized by UV-vis, FTIR, ¹H-NMR, 13C-NMR, HHCOSY, TOCSY and cyclic voltammetry. Computational analyses at the level of DFT and TD-DFT were performed to study its electronic and molecular structures. The results of these analyses elucidated the behaviors of the UV-vis and electrochemical data. Analysis of the transitions in the computed spectrum showed that the most important band is primarily composed of a HOMO→LUMO transition, designated as an intraligand (IL) charge transfer.

Synthesis and thermal studies of solid state 2-chloro-benzylidenepyruvic acid and its compounds with sodium, aluminium (III), gallium (III) and indium (III) cations

The synthesis of sodium 2-chlorobenzylidenepyruvate and its corresponding acid as well as binary, binary together with it's acid or hydroxo-2-chorobenzylidenepyruvate of aluminium (III), gallium (III) and indium (III), were isolated. Chemical analysis, thermogravimetry, derivative thermogravimetry (TG/DTG), simultaneous thermogravimetry-differential thermal analysis (TG-DTA) and X-ray powder diffractometry have been employed to characterize and to study the thermal behaviour of these compounds. The results provided information concerning the stoichiometry, crystallinity, thermal stability and thermal decomposition.

Synthesis, characterization and thermal studies of solid state 4-methylbenzylidenepyruvate of some trivalent metal ions

Solid state compounds of 4-methylbenzylidenepyruvate with Al(III), Ga(III), In(III) and Sc(III) have been synthesized. Complexometry, X-ray powder diffractometry, infrared spectroscopy and simultaneous thermogravimetry-differential thermal analysis (TG-DTA) have been used to characterize and to study the thermal behavior of these compounds. The results provided information concerning the stoichiometry, crystallinity, thermal stability and thermal decomposition of these compounds.

Synthesis, characterization and thermal studies on solid 3-methoxybenzoate of some bivalent transition metal ions

Solid-state M-3-MeO-Bz compounds, where M stands for bivalent Mn, Co, Ni, Cu and Zn and 3-MeO-Bz is 3-methoxybenzoate, have been synthesized. Simultaneous thermogravimetry and differential thermal analysis (TG-DTA), differential scanning calorimetry (DSC), X-ray powder diffractometry, infrared spectroscopy, and chemical analysis were used to characterize and to study the thermal behaviour of these compounds. The results led to information about the composition, dehydration, thermal stability and thermal decomposition of the isolated compounds.

Potentiometric and conductometric studies on the system acid-isopolytungstate and the formation of lanthanum tungstates

The stoichiometry of the polyanions formed by the action of nitric acid on sodium tungstate (< 0.01M) has been studied by means of electrometric techniques involving pH-potentiometric and conductometric titrations. The well defined inflections and breaks in the titration curves provide evidence for the existence of the polyanions, para-W12O41(10-) and meta-W12O39(6-) corresponding to the ratio of H+:WO4(2-) as 7:6 and 9:6 in the pH ranges 5.7-6.0 and 3.6-4.1, respectively. The interaction of lanthanum nitrate with sodium tungstate solutions, at specific pH levels 8.0, 5.9 and 4.0 was also studied by pH and conductometric titrations, in aqueous and alcoholic media, with each of the reagents alternatively used as titrant. The electrometric experiments provide definite evidence of the formation of normal-La2O3.3WO3, para-5La2O3.36WO3 and meta-La2O3.12WO3 tungstates in the vicinity of pH 6.3, 5.0 and 4.2, respectively. Analytical investigations on the precipitates formed confirm the results of the electrometric study.

Synthesis, characterization and thermal studies on solid state 3-methoxybenzoate of lighter trivalent lanthanides

Solid-state Ln -3-MeO-Bz compounds, where Ln stands for lighter trivalent lanthanides (La Sm) and 3-methoxybenzoate, have been synthesized. Thermogravimetry (TG), differential scanning calorimetry (DSC), X-ray powder diffractometry, infrared spectroscopy, and complexometry were used to characterize and to study the thermal behaviour of these compounds. The results led to information concerning the composition, dehydration, polymorphic transformation, thermal behaviour and thermal decomposition of the synthesized compounds.

Biheterocyclic ligands: synthesis, characterization and coordinating properties of bis(4-amino-5-mercapto-1,2,4-triazol-3-yl) alkanes with transition metal ions and their thermokinetic and biological studies

The Co(II), Ni(II) and Cu(II) metal ions complexes of Bis(4-amino-5-mercapto-1,2,4-triazol-3-yl) alkanes (BATs) have been prepared and characterized by elemental analysis, conductivity measurements infrared, magnetic susceptibility, the electronic spectral data and thermal studies. Based on spectral and magnetic results, the ligands are tetradentate coordinating through the N and S-atoms of BATs; six-coordinated octahedral or distorted octahedral and some times four-coordinated square planar were proposed for these complexes. Activation energies computed for the thermal decomposition steps were compared. The ligands and their metal complexes were tested in vitro for their biological effects. Their activities against two gram-positive, two gram-negative bacteria and two fungal species were found to vary from moderate to very strong.

Synthesis and magnetic studies of copper(II)-lanthanide(III) 5-bromosalicylideneglycylglycine

The physico-chemical properties of the new 3d-4f heteronuclear complexes with general formula LnCu3(C11H8N2 O4Br)3·13H2O (where Ln = Pr, Eu, Gd, Tb, Er, Yb and H3(C11H8N2 O4Br) - 5-bromosalicylideneglycylglycine) were studied. The compounds were characterized by elemental, spectral and thermal analyses and magnetic measurements. The formation of Schiff base is evidenced by a strong band at ca. 1646-1650 cm-1 attributable to C=N stretching mode. The presence of water molecules is confirmed by broad absorptions with maximum at 3360 - 3368 cm-1. The Cu(II)-Ln(III) complexes are stable up to ca. 318 K. During dehydration process the water molecules are lost probably in two stages. The magnetic susceptibility data for these complexes change with temperature according to the Curie-Weiss law.

Potentiometric and conductimetric studies of chemical equilibria for pyridoxine hydrochloride in aqueous solutions: simple experimental determination of pKa values and analytical applications to pharmaceutical analysis

The combination of two low-cost classical procedures based on titrimetric techniques is presented for the determination of pyridoxine hydrochloride in pharmaceuticals samples. Initially some experiments were carried out aiming to determine both pKa1 and pKa2 values, being those compared to values of literature and theoretical procedures. Commercial samples containing pyridoxine hydrochloride were electrochemically analysed by exploiting their acid-base and precipitation reactions. Potentiometric titrations accomplished the reaction between the ionizable hydrogens present in pyridoxine hydrochloride, being NaOH used as titrant; while the conductimetric method was based on the chemical precipitation between the chloride of pyridoxine hydrochloride molecule and Ag+ ions from de silver nitrate, changing the conductivity of the solution. Both methods were applied to the same commercial samples leading to concordant results when compared by statistical tests (95 and 98% confidence levels). Recoveries ranging from 99.0 to 108.1% were observed, showing no significant interference on the results.