Synthesis and SAR study of N-(4-hydroxy-3-(2-hydroxynaphthalene-1-yl)phenyl)-arylsulfonamides: heat shock protein 90 (Hsp90) inhibitors with submicromolar activity in an in vitro assay

Heat shock protein 90 is emerging as an important target in cancer chemotherapy. In a program directed toward identifying novel chemical probes for Hsp90, we found N-(4-hydroxy-3-(2-hydroxynaphthalene-1-yl)phenyl)benzene sulfonamide as an Hsp90 inhibitor with very weak activity. In this report, we present a new and general method for the synthesis of a variety of analogs around this scaffold, and discuss their structure-activity relationships.     

Microsatellites as DNA markers in cultivated peanut (<Emphasis Type="Italic">Arachis hypogaea</Emphasis> L.)

Background  

Genomic research of cultivated peanut has lagged behind other crop species because of the paucity of polymorphic DNA markers found in this crop. It is necessary to identify additional DNA markers for further genetic research in peanut.     

Further phenotypic delineation of subtelomeric (terminal) 4q deletion with emphasis on intracranial and reproductive anatomy

Hypoplastic left heart syndrome(HLHS) refers to the abnormal development of the left-sided cardiac structures, resulting in obstruction to blood flow from the left ventricular outflow tract. In addition, the syndrome includes underdevelopment of the left ventricle, aorta, and aortic arch, as well as mitral atresia or stenosis. HLHS has been reported to occur in approximately 0.016 to 0.036% of all live births. Newborn infants with the condition generally are born at full term and initially appear healthy. As the arterial duct closes, the systemic perfusion becomes decreased, resulting in hypoxemia, acidosis, and shock. Usually, no heart murmur, or a non-specific heart murmur, may be detected. The second heart sound is loud and single because of aortic atresia. Often the liver is enlarged secondary to congestive heart failure. The embryologic cause of the disease, as in the case of most congenital cardiac defects, is not fully known. The most useful diagnostic modality is the echocardiogram. The syndrome can be diagnosed by fetal echocardiography between 18 and 22 weeks of gestation. Differential diagnosis includes other left-sided obstructive lesions where the systemic circulation is dependent on ductal flow (critical aortic stenosis, coarctation of the aorta, interrupted aortic arch). Children with the syndrome require surgery as neonates, as they have duct-dependent systemic circulation. Currently, there are two major modalities, primary cardiac transplantation or a series of staged functionally univentricular palliations. The treatment chosen is dependent on the preference of the institution, its experience, and also preference. Although survival following initial surgical intervention has improved significantly over the last 20 years, significant mortality and morbidity are present for both surgical strategies. As a result pediatric cardiologists continue to be challenged by discussions with families regarding initial decision relative to treatment, and long-term prognosis as information on long-term survival and quality of life for those born with the syndrome is limited.     

Comparison of different delivery systems of DNA vaccination for the induction of protection against tuberculosis in mice and guinea pigs

The great challenges for researchers working in the field of vaccinology are optimizing DNA vaccines for use in humans or large animals and creating effective single-dose vaccines using appropriated controlled delivery systems. Plasmid DNA encoding the heat-shock protein 65 (hsp65) (DNAhsp65) has been shown to induce protective and therapeutic immune responses in a murine model of tuberculosis (TB). Despite the success of naked DNAhsp65-based vaccine to protect mice against TB, it requires multiple doses of high amounts of DNA for effective immunization. In order to optimize this DNA vaccine and simplify the vaccination schedule, we coencapsulated DNAhsp65 and the adjuvant trehalose dimycolate (TDM) into biodegradable poly (DL-lactide-co-glycolide) (PLGA) microspheres for a single dose administration. Moreover, a single-shot prime-boost vaccine formulation based on a mixture of two different PLGA microspheres, presenting faster and slower release of, respectively, DNAhsp65 and the recombinant hsp65 protein was also developed. These formulations were tested in mice as well as in guinea pigs by comparison with the efficacy and toxicity induced by the naked DNA preparation or BCG. The single-shot prime-boost formulation clearly presented good efficacy and diminished lung pathology in both mice and guinea pigs.     

Enhanced microtubule binding and tubulin assembly properties of conformationally constrained paclitaxel derivatives

Microtubule binding and tubulin assembly promotion by a series of conformationally restricted paclitaxel (PTX) derivatives was investigated. In these derivatives, the C-4 acetate of the taxane is tethered to the C-3' phenyl at ortho and meta positions with different length linkers. The apparent affinity of these derivatives for GMPCPP-stabilized microtubules was assessed by a competition assay, and their influence on microtubule polymerization was evaluated by measuring the critical concentration of GDP-tubulin in the presence of the respective molecule. In general, taxane derivatives with higher apparent affinity for microtubules induced tubulin assembly more efficiently. Among the derivatives, molecules with the shortest tether display the strongest affinity for microtubules. These derivatives exhibited enhanced microtubule stabilization properties and efficiently induced GDP-tubulin assembly into microtubules at low temperature of 12 degrees C and in the absence of Mg2+ ions in 0.1 M PIPES. Based on molecular dynamics simulations, we propose that the enhanced ability to assemble microtubules by these taxane derivatives is linked to their ability to effectively shape the conformation of the M-loop of tubulin for cross-protofilament interaction.     

Detection of cytokinins and auxin in plant tissues using histochemistry and immunocytochemistry

We report a new method for histochemical localization of cytokinins (CKs) in plant tissues based on bromophenol blue/silver nitrate staining. The method was validated by immunohistochemistry using anti-trans-zeatin riboside antibody. Indole-3-acetic acid (auxin, IAA) was localized by anti-IAA antibody in plant tissues as a proof for IAA histolocalization. We used root sections, because they are major sites of CKs synthesis, and insect galls of Piptadenia gonoacantha that accumulate IAA. Immunostaining confirmed the presence of zeatin and sites of accumulation of IAA indicated by histochemistry. The colors developed by histochemical reactions in free-hand sections of plant tissues were similar to those obtained by thin layer chromatography (TLC), which reinforced the reactive sites of zeatin. The histochemical method for detecting CKs is useful for galls and roots, whereas IAA detection is more efficient for gall tissues. Therefore, galls constitute a useful model for validating histochemical techniques due to their rapid cell cycles and relatively high accumulation of plant hormones.     

A Lectin-like Molecule is Discharged from Mucocysts of Tetrahymena pyriformis in the Presence of Insulin

ABSTRACT. By use of a monoclonal antibody directed against purified lectin from the sponge Geodia cydonium it was demonstrated that the mucocysts of Tetrahymena pyriformis contain a substance immunologically similar to that found in G. cydonium . In extracts of T. pyriformis the monoclonal antibody recognizes a 36 kDa protein; binding could be abolished by adsorption of the antibody with (i) crude extract, (ii) purified lectin from G. cydonium and (iii) a 29 aa long peptide. In addition the data show that 10^-6 M of insulin causes first the release of mucocyst material, which reacts with the lectin antibody, and second its subsequent redistribution on the surface of the somatic cilia and the oral field.     

Comparison of pome fruit orchard inhabiting spider assemblages at different geographical scales

1 The composition of pome fruit orchard inhabiting spider assemblages was investigated at different geographical scales (Holarctic, European, inter- and intraregional levels within Hungary) using previous faunistic studies and data collected in Hungary between 1995 and 1997. Samples in Hungary were taken from the canopy and herb layer of apple and pear orchards in five markedly different fruit-growing regions by beating and sweep-netting methods. 2 The composition of canopy spider assemblages of apple orchards was analysed for the Holartic region and found to be determined by latitude at family level, and by the main zoogoegraphical regions at genus level. At the European scale, both the genus and species composition changed along a north–south gradient. 3 A comparison among apple and pear orchards located in different regions in Hungary, showed that both foliage- and grass-dwelling spider assemblages varied considerably in species composition and dominance order. 4 Within the same region, both the foliage- and grass-dwelling spider assemblages showed moderate differences in apple and pear orchards submitted to different treatments. Although the assemblages of spiders inhabiting the canopy and the herbaceous layer can be unambiguously distinguished, some overlap still occurs. 5 We conclude that the composition of spider assemblages is basically determined by geographical location. Although both pesticide treatments and available prey densities can influence the population of spiders, such factors are of moderate importance when compared with the effect of regionality, even when considered at smaller scale. However, most members of the family Theridiidae and the large orb-weavers (Araneidae) decreased considerably in treated plots. Scale-specific differences are thus relevant in determining the composition of prey–predator systems in orchards, and should be taken into account when designing integrated pest management (IPM) programs for apple and pear orchards.