pH-Responsive polymers

This review summarizes pH-responsive monomers, polymers and their derivative nano- and micro-structures including micelles, cross-linked micelles, microgels and hydrogels.

An Unusual Metastasis of Prostate Cancer to Duodenum

Prostate cancer is the second most common cancer in men in the world. The presentation of this cancer may range from microscopic to metastatic forms. Patients with prostate cancer may experience metastasis to the gastrointestinal system. Here, we present a case of prostate cancer metastasizing to the third portion of duodenum, a very uncommon site of metastasis. To the best of authors' knowledge, this is the first case report in the literature.

Neu?Laxova syndrome: a case report and review of the literature

Neu-Laxova syndrome (NLS) is a rare autosomal recessive syndrome, characterized by severe intrauterine growth retardation (IUGR), microcephaly, abnormal brain development, oedema and ichthyosis. It was first reported in 1971 by Neu et al. (Pediatrics 47: 610-612) and since then no more than 60 cases have been reported. A newborn girl delivered from a 29-year-old healthy mother was admitted to hospital with a thick membrane covering her body and dismorphic appearance. The diagnosis of NLS was made according to characteristic features. The syndrome is known to have a poor prognosis and the baby lived for 9 weeks. This case is one of the longest living cases of NLS and the fourth case reported from Turkey.

Histidine-rich protein 2 of the malaria parasite, Plasmodium falciparum, is involved in detoxification of the by-products of haemoglobin degradation

The histidine-rich protein 2 (PfHRP2) of Plasmodium falciparum has been implicated in the detoxification of ferriprotoporphyrin IX (FP) moieties that are produced as by-products of the digestion of haemoglobin. In this work, we have used a spectroscopic analysis to confirm that recombinant PfHRP2 binds FP. A monoclonal antibody that recognises both recombinant and authentic PfHRP2 was used in immunofluorescence microscopy studies. We found that PfHRP2 is mainly located in the erythrocyte cytosol of infected erythrocytes, however, dual labelling studies suggest that the location of a sub-population of the PfHRP2 molecules overlaps with that of the food vacuole-associated protein, P-glycoprotein homologue (Pgh-1). A semi-quantitative analysis of the level of PfHRP2 in infected erythrocytes suggests a concentration of a few micromolar in the food vacuole. Under conditions designed to mimic the parasite food vacuole, we found that 1.2 microM PfHRP2 is sufficient to catalyse the conversion of about 30% of a 100 microM sample of FP to beta-haematin within 24 h. Moreover, PfHRP2 is capable of promoting the H(2)O(2)-induced degradation of FP at pH 5.2. PfHRP2 also efficiently enhances the ability of FP to catalyse the H(2)O(2)-mediated oxidation of the model co-factor, ortho-phenylene diamine (OPD). These data suggest that PfHRP2 may promote the detoxification of FP and reactive oxygen species within the food vacuole. By contrast, PfHRP2 inhibits the destruction of FP by glutathione (GSH) at pH 7.4. This suggests that PfHRP2 is not a catalyst of FP degradation outside the food vacuole.

Inhibition of heme detoxification processes underlies the antimalarial activity of terpene isonitrile compounds from marine sponges

A series of terpene isonitriles, isolated from marine sponges, have previously been shown to exhibit antimalarial activities. Molecular modeling studies employing 3D-QSAR with receptor modeling methodologies performed with these isonitriles showed that the modeled molecules could be used to generate a pharmacophore hypothesis consistent with the experimentally derived biological activities. It was also shown that one of the modeled compounds, diisocyanoadociane (4), as well as axisonitrile-3 (2), both of which have potent antimalarial activity, interacts with heme (FP) by forming a coordination complex with the FP iron. Furthermore, these compounds were shown to inhibit sequestration of FP into beta-hematin and to prevent both the peroxidative and glutathione-mediated destruction of FP under conditions designed to mimic the environment within the malaria parasite. By contrast, two of the modeled diterpene isonitriles, 7-isocyanoamphilecta-11(20),15-diene (12) and 7-isocyano-15-isothiocyanatoamphilecta-11(20)-ene (13), that displayed little antimalarial activity also showed little inhibitory activity in these FP detoxification assays. These studies suggest that the active isonitrile compounds, like the quinoline antimalarials, exert their antiplasmodial activity by preventing FP detoxification. Molecular dynamics simulations performed with diisocyanoadociane (4) and axisonitrile-3 (2) allowed their different binding to FP to be distinguished.