Targeted-nanoliposomal combretastatin A4 (CA-4) as an efficient antivascular candidate in the metastatic cancer treatment

A number of antiangiogenic drugs have been approved by the Food and Drug Administration which are used in cancer therapy, and variety of other agents in several stages of clinical development or in preclinical assessment. Among these, combretastatin A4 (CA-4) is an under-researched inhibitor of angiogenesis that shows potential activity in the treatment of advanced tumors with migration capacity. However, its clinical application has been limited due to poor water solubility, low bioavailability, rapid metabolism, and systemic elimination. During the last decade, numerous investigations have been done to overcome these problems by using different CA-4 delivery systems or developing produgs of CA-4 or its structural analogs. Nevertheless, these strategies could not be efficient out of the undesired side effects on normal tissues. Nanoliposomal CA-4 not only benefits from the advantage of using liposomal drugs as opposed to free drugs but also can accumulate in the tumor site via specific targeting ligands, which leads to efficient targeting and enhancement of bioavailability. To the best of our knowledge, we consider an important attempt to understand different factors that might influence the CA-4 loading and release pattern of liposomes and the consequent results in tumor therapy. In this review, we shed light on various studied liposomal CA-4 formulations showing application thereof in cancer treatment.     

Light and electron microscope studies of effects of 50 Hz electromagnetic fields on preincubated chick embryo

We investigated the effects of an electromagnetic field (EMF) of 50 Hz, 1.33-7.32 mT on sections of preincubated white leghorn chicken embryos using light, SEM and TEM microscopes. Five hundred healthy, fresh, and fertilized eggs (55-65 g) were divided into three groups of experimental (n = 18-20), control (n = 60), and sham (n = 50). Experimental eggs (inside the coil) were exposed to 15 different intensities (1.33-7.32 mT) for morphological surveys and to the known most effective intensities for light, scanning electron microscopy (SEM), and transmission electron microscopy (TEM) studies. Sham groups were located inside the same coil with no exposure for 24 h before incubation. Control, sham, and experimental groups were then incubated in an incubator (38 +/- 0.5 degrees C, 60% humidity) for 4 days. At the end of this period, embryos were removed from their shells, prepared for morphometric, light, and SEM/TEM studies. Results of light microscopic studies (serial sections, 6mu) and morphometric data showed significant differences between different groups (P < 0.005). Larger and abnormal brain cavities, spina bifida, monophthalmia, microphthalmia, anophthalmia, and growth retardation were shown on SEM. TEM sections demonstrated that the nucleus was condensed, the nuclear envelope disappeared, and mitochondria degenerated. Golgi apparatus and endoplasmic reticulum were the least affected organelles. The Telencephlon was the most affected region, and the retina was altered more than the lens. We conclude that EMFs affect the brain, especially the Telencephalon and eye of preincubated-exposed chick embryo at the morphological and cellular level, nuclei are the most affected part, and our data agrees with "Ubeda's windows effects" of EMFs on preincubated chick embryos.     

Early patterned stimulation leads to changes in adult behavior and gene expression in C. elegans

Across phylogeny, early experience plays a critical role in nervous system development. In these experiments, we investigated the long-term effects that specific patterns of sensory experience during development had on the biology and function of the Caenorhabditis elegans nervous system. The delivery of a specific pattern of mechanosensory stimulation in the first larval stage (L1) produced significant enhancement in the tap withdrawal behavioral response, expression patterns of an ionotropic glutamate receptor (iGluR) subunit and mRNA levels for that receptor in 3-day-old adult worms and a depression of these same three measures in 5-day-old adult worms. A critical period for the 3-day enhanced behavior and GLR distribution was observed in L1, whereas there was no critical period for the depressed effects observed in 5-day-old worms. The spaced pattern of stimulation was essential for expression of this effect: Various forms of massed training produced neither the enhancement at 3 days nor the depression at 5 days. The 5-day depressed behavioral response had many features in common with long-term memory, including sensitivity to disruption following retrieval. The different behavioral and molecular effects that early patterned mechanosensory stimulation produced in 3 and 5-day-old worms led us to hypothesize that separate cellular phenomena produced the enhanced 3-day and depressed 5-day behaviors and molecular effects.     

Analysis and identification of beta-turn types using multinomial logistic regression and artificial neural network

MOTIVATION: So far various statistical and machine learning techniques applied for prediction of beta-turns. The majority of these techniques have been only focused on the prediction of beta-turn location in proteins. We developed a hybrid approach for analysis and prediction of different types of beta-turn. RESULTS: A two-stage hybrid model developed to predict the beta-turn Types I, II, IV and VIII. Multinomial logistic regression was initially used for the first time to select significant parameters in prediction of beta-turn types using a self-consistency test procedure. The extracted parameters were consisted of 80 amino acid positional occurrences and 20 amino acid percentages in beta-turn sequence. The most significant parameters were then selected using multinomial logistic regression model. Among these, the occurrences of glutamine, histidine, glutamic acid and arginine, respectively, in positions i, i + 1, i + 2 and i + 3 of beta-turn sequence had an overall relationship with five beta-turn types. A neural network model was then constructed and fed by the parameters selected by multinomial logistic regression to build a hybrid predictor. The networks have been trained and tested on a non-homologous dataset of 565 protein chains by 9-fold cross-validation. It has been observed that the hybrid model gives a Matthews correlation coefficient (MCC) of 0.235, 0.473, 0.103 and 0.124, respectively, for beta-turn Types I, II, IV and VIII. Our model also distinguished the different types of beta-turn in the embedded binary logit comparisons which have not carried out so far. AVAILABILITY: Available on request from the authors.     

A novel mechanism of iron-core formation by Pyrococcus furiosus archaeoferritin, a member of an uncharacterized branch of the ferritin-like superfamily

Storage of iron in a nontoxic and bioavailable form is essential for many forms of life. Three subfamilies of the ferritin-like superfamily, namely, ferritin, bacterioferritin, and Dps (DNA-binding proteins from starved cells), are able to store iron. Although the function of these iron-storage proteins is constitutive to many organisms to sustain life, the genome of some organisms appears not to encode any of these proteins. In an attempt to identify new iron-storage systems, we have found and characterized a new member of the ferritin-like superfamily of proteins, which unlike the multimeric storage system of ferritin, bacterioferritin, and Dps is monomeric in the absence of iron. Monomers catalyze oxidation of Fe(II) and they store the Fe(III) product as they assemble to form structures comparable to those of 24-meric ferritin. We propose that this mechanism is an alternative method of iron storage by the ferritin-like superfamily of proteins in organisms that lack the regular preassociated 24-meric/12-meric ferritins.     

The genus Eodasycladus (Lower Jurassic dasycladalean green alga) and its relationship with Palaeodasycladus

The Lower Jurassic genus Eodasycladus is discussed according to the characters of type species and compared with the other species known in the literature. The architecture of two species attributed to the genus Palaeodasycladus, P. alanensis Soka?, and P. benceki Soka?, is examined and an alternative organization of the thallus is prospected. P. alanensis is considered a valid species, but its characters require to transfer the taxon to the genus Eodasycladus. P. benceki is considered synonymous with P. alanensis.     

Murine mesenchymal stem cells isolated by low density primary culture system

Murine mesenchymal stem cells (mMSC) and the difficult task of isolation and purification of them have been the subject of rather extensive investigation. The present study sought to isolate these cells from two different mouse strains, one outbred and the other inbred, primarily through a relatively simple but novel approach, the most important feature of which was the low density primary culture of bone marrow cells. For this purpose, mononuclear cells from either NMRI or BALB/c bone marrow were plated at about 500 cells per well of 24-well plates and incubated for 7 days. At this point, the fibroblastic clones that had emerged were pooled together and expanded through several subcultures. To investigate the mesenchymal nature, we differentiated the cells into the osteoblastic, chondrocytic and adipocytic lineages in different subcultures up to passage 10. According to the results, 1 week after culture initiation, several clones each comprising several fibroblastic cells appeared in each plate. The cells from different passages were capable of differentiating into corresponding skeletal tissues. In the present investigation, the best culture condition for maximum proliferation and also the expression of certain surface marker on isolated cells were examined. In this term the two murine strains showed some differences.     

Embryogenic callus culture of Tribulus terrestris L. a potential source of harmaline, harmine and diosgenin

In the present study, a simple one medium formulation protocol for callus culture, somatic embryogenesis and in vitro production of β-carboline alkaloids and diosgenin in Tribulus terrestris L. was developed. Extensive callus induction and proliferation was obtained in leaf explant on Murashige and Skoog (MS) medium supplemented with 5.0 μM 6 benzyl adenine (BA) and 2.5 μM α-naphthaleneacetic acid (NAA). The embryogenic callus was maintained on subculture to fresh parental medium at 4-week intervals over a period of 28 months. The frequency of embryo formation was at a maximum (18.1 ± 0.9 per g of callus) on MS medium containing 5.0 μM BA and 2.5 μM NAA together with 75 mg l⁻¹ casein hydrolysate. Globular embryo developed into torpedo stage embryo under the influence of starvation. The accumulation of β-carboline alkaloids (harmaline and harmine) and steroidal saponin (diosgenin) in non-embryogenic and embryogenic callus culture derived from leaf explant was compared with root, leaf, stem, and fruit of the mother plant. The embryogenic callus accumulated equivalent amounts of harmaline (66.4 ± 0.5 μg/g dry weight), harmine (82.7 ± 0.6 μg/g dry weight), and diosgenin (170.7 ± 1.0 μg/g dry weight) to that of the fruit of T. terrestris. The embryogenic callus culture of this species might offer a potential source for production of important pharmaceuticals.     

Heterologous expression,purification and characterization of the influenza A virus <Emphasis Type="Italic">M2e</Emphasis> gene fused to <Emphasis Type="Italic">Mycobacterium tuberculosis</Emphasis> HSP70<Subscript>359–610</Subscript> in prokaryotic system as a fusion protein

One of the concerns about influenza A vaccine based on M2e protein is their limited potency; hence, optimal approaches to enhance immunogenicity of M2e protein immunization remain to be established. It seems by linking this M2e-peptide to an appropriate carrier such as mycobacterium tuberculosis C-terminal 28-kDa domain of HSP70 (HSP70_359–610), we can render it very immunogenic. According to previous reports, this study was designed to produce a novel influenza A virus recombinant fusion protein consisted of M2e, a potent immunogenic protein from influenza A virus, fused to C-terminal domain of mycobacterium tuberculosis HSP70, HSP70_359–610, as a carrier and adjuvant. We fused the genes of M2e and HSP70 _359–610 then inserted in pQE-60, prokaryotic expression vector. This recombinant fusion protein with a 6xHis-tag was successfully over expressed in Escherichia coli M-15. The recombinant fusion protein was purified by Ni–NTA affinity chromatography under denaturing conditions, followed by urea gradient dialysis. The purified fusion protein was analyzed on SDS–PAGE. Western blot assay was used to examine the immunoreaction of the expressed protein using commercial penta-His HRP conjugate antibody. The antigenicity and biological activity of the recombinant protein was also qualitatively detected on the infected MDCK cells surface by immunofluorescence and cell-ELISA assay using rabbit’s immunized antiserum. This observation suggest that the expressed fusion protein is useful as a universal recombinant vaccine for overcoming highly mutational influenza virus, but more immunological study in animal lab remains to be evaluated.