Molecular phylogeny and morphometric analyses reveal deep divergence between Amazonia and Atlantic Forest species of Dendrophryniscus

Dendrophryniscus is an early diverging clade of bufonids represented by few small-bodied species distributed in Amazonia and the Atlantic Forest. We used mitochondrial (414 bp of 12S, 575 bp of 16S genes) and nuclear DNA (785 bp of RAG-1) to investigate phylogenetic relationships and the timing of diversification within the genus. These molecular data were gathered from 23 specimens from 19 populations, including eight out of the 10 nominal species of the genus as well as Rhinella boulengeri. Analyses also included sequences of representatives of 18 other bufonid genera that were publically available. We also examined morphological characters to analyze differences within Dendrophryniscus. We found deep genetic divergence between an Amazonian and an Atlantic Forest clade, dating back to Eocene. Morphological data corroborate this distinction. We thus propose to assign the Amazonian species to a new genus, Amazonella. The species currently named R. boulengeri, which has been previously assigned to the genus Rhamphophryne, is shown to be closely related to Dendrophryniscus species. Our findings illustrate cryptic trends in bufonid morphological evolution, and point to a deep history of persistence and diversification within the Amazonian and Atlantic rainforests. We discuss our results in light of available paleoecological data and the biogeographic patterns observed in other similarly distributed groups.     

Interactive effects of temperature and heavy metals (Cd, Pb) on the elongation growth in maize coleoptiles

The effect of Cd and Pb on endogenous and IAA-induced elongation growth and medium pH of maize coleoptile segments incubated at 20, 25 and 30 °C was studied. It was found that the elongation of coleoptile segments and proton extrusion increased with the temperature and reached its maximum at 30 °C. For Cd, the maximal inhibition of endogenous and IAA-induced growth as well as medium acidification of coleoptile segments was observed at 25 °C. Meanwhile, Pb, irrespective of the temperature, diminished the growth of the segments by ca. 20%, increasing the acidification of the incubation medium. It was also found that in contrast to Cd, Pb accumulation in maize coleoptile segments did not correlate with temperature. The results suggest that the toxic effect of Cd on elongation growth of coleoptile segments is connected with the decrease of the PM H(+)-ATPase activity and probably with Cd-induced high acivity of IAA oxidase, whereas the effect of Pb did not depend on activity of any of the enzymes.     

Twenty-year cytogenetic and molecular follow-up of a patient with ring chromosome 15: a case report

ABSTRACT: INTRODUCTION: Ring chromosome 15 is a rare disorder, with only a few over 40 cases reported in the literature. There are only two previous reports of cases where patients with ring chromosome 15 have been followed-up. CASE PRESENTATION: We report here on the 20-year clinical and cytogenetic follow-up of a patient with a ring chromosome 15. Our patient, a Caucasoid Asian woman, presented with short stature, microcephaly, minor dysmorphic features, hyperextensible knees, generalized hirsutism, cafe-au-lait and small hypochromic spots spread over her face and the front of her chest and abdomen, dorsolumbar scoliosis and mild intellectual disability. She was followed-up from the age of eight to 28 years. When she was 27 years old, she was reported by her mother to present with compulsive overeating and an aggressive mood when challenged. Karyotyping revealed that the majority of her cells harbored one normal chromosome and one ring chromosome. Silver staining revealed the presence of the nucleolar organizer region in the ring chromosome. Ring loss and/or secondary aberrations exhibited a slight increase over time, from 4.67% in 1989 to 7.67% in 2009, with the presence of two monocentric rings, cells with interlocked rings, a dicentric ring, and broken or open rings. A genome-wide array technique detected a 5.5Mb deletion in 15q26.2. CONCLUSIONS: We observed that some phenotypic alterations in our patient can be associated with gene loss and haploinsufficiency. Other features may be related to different factors, including ring instability and epigenetic factors.     

Proteasome inhibition and ROS generation by 4-nerolidylcatechol induces melanoma cell death

Induction of apoptotic cell death in response to chemotherapy and other external stimuli has proved extremely difficult in melanoma, leading to tumor progression, metastasis formation and resistance to therapy. A promising approach for cancer chemotherapy is the inhibition of proteasomal activity, as the half‐life of the majority of cellular proteins is under proteasomal control and inhibitors have been shown to induce cell death programs in a wide variety of tumor cell types. 4‐Nerolidylcatechol (4‐NC) is a potent antioxidant whose cytotoxic potential has already been demonstrated in melanoma tumor cell lines. Furthermore, 4‐NC was able to induce the accumulation of ubiquitinated proteins, including classic targets of this process such as Mcl‐1. As shown for other proteasomal inhibitors in melanoma, the cytotoxic action of 4‐NC is time‐dependent upon the pro‐apoptotic protein Noxa, which is able to bind and neutralize Mcl‐1. We demonstrate the role of 4‐NC as a potent inducer of ROS and p53. The use of an artificial skin model containing melanoma also provided evidence that 4‐NC prevented melanoma proliferation in a 3D model that more closely resembles normal human skin.     

The spin label amino acid TOAC and its uses in studies of peptides: chemical, physicochemical, spectroscopic, and conformational aspects

We review work on the paramagnetic amino acid 2,2,6,6-tetramethyl-N-oxyl-4-amino-4-carboxylic acid, TOAC, and its applications in studies of peptides and peptide synthesis. TOAC was the first spin label probe incorporated in peptides by means of a peptide bond. In view of the rigid character of this cyclic molecule and its attachment to the peptide backbone via a peptide bond, TOAC incorporation has been very useful to analyze backbone dynamics and peptide secondary structure. Many of these studies were performed making use of EPR spectroscopy, but other physical techniques, such as X-ray crystallography, CD, fluorescence, NMR, and FT-IR, have been employed. The use of double-labeled synthetic peptides has allowed the investigation of their secondary structure. A large number of studies have focused on the interaction of peptides, both synthetic and biologically active, with membranes. In the latter case, work has been reported on ligands and fragments of GPCR, host defense peptides, phospholamban, and β-amyloid. EPR studies of macroscopically aligned samples have provided information on the orientation of peptides in membranes. More recent studies have focused on peptide-protein and peptide-nucleic acid interactions. Moreover, TOAC has been shown to be a valuable probe for paramagnetic relaxation enhancement NMR studies of the interaction of labeled peptides with proteins. The growth of the number of TOAC-related publications suggests that this unnatural amino acid will find increasing applications in the future.     

Analysis of polyphenols,phytosterols, and bitter principles in <Emphasis Type="Italic">Teucrium</Emphasis> L. species

Total polyphenols, tannins, β-sitosterol, and bitterness values were determined in native and cultivated populations of Teucrium L. species from Croatia (T. arduini L., T. botrys L., T. chamaedrys L., T. flavum L., T. montanum L., T. polium L., and T. scordium L. subsp. scordioides Schreb.). Teucrium species have long been present in folk medicine for diverse medicinal uses, but little is known about polyphenols, phytosterols, and bitter principles. Spectrophotometrically determined contents of total polyphenols (TP) and tannins (T) significantly varied among investigated Teucrium species and were somewhat higher in native populations. The highest TP and T contents were measured in native specimens of T. montanum (TP: 13.68%; T: 3.48%). Scanning densitometry was used for measurements of β-sitosterol levels in plant samples ranged from 0.056% (T. montanum) to 0.129% (T. botrys), and it was not significantly different between native and cultivated specimens of the same plant species. Bitterness values were similar for native and cultivated samples of the same plant species; the highest was measured for T. montanum (15659). The present study suggests that Teucrium species growing in Croatia have potential for cultivation and might be a valuable source of natural bioactive compounds.     

Cochlin, intraocular pressure regulation and mechanosensing

Fluid shear modulates many biological properties. How shear mechanosensing occurs in the extracellular matrix (ECM) and is transduced into cytoskeletal change remains unknown. Cochlin is an ECM protein of unknown function. Our investigation using a comprehensive spectrum of cutting-edge techniques has resulted in following major findings: (1) over-expression and down-regulation of cochlin increase and decrease intraocular pressure (IOP), respectively. The overexpression was achieved in DBA/2J-Gpnmb(+)/SjJ using lentiviral vectors, down-regulation was achieved in glaucomatous DBA/2J mice using targeted disruption (cochlin-null mice) and also using lentiviral vector mediated shRNA against cochlin coding region; (2) reintroduction of cochlin in cochlin-null mice increases IOP; (3) injection of exogenous cochlin also increased IOP; (4) increasing perfusion rates increased cochlin multimerization, which reduced the rate of cochlin proteolysis by trypsin and proteinase K; The cochlin multimerization in response to shear stress suggests its potential mechanosensing. Taken together with previous studies, we show cochlin is involved in regulation of intraocular pressure in DBA/2J potentially through mechanosensing of the shear stress.     

A Collaborative Informatics Infrastructure for Multi-Scale Science

The Collaboratory for Multi-scale Chemical Science (CMCS) is developing a powerful informatics-based approach to synthesizing multi-scale information in support of systems-based research and is applying it within combustion science. An open source multi-scale informatics toolkit is being developed that addresses a number of issues core to the emerging concept of knowledge grids including provenance tracking and lightweight federation of data and application resources into cross-scale information flows. The CMCS portal is currently in use by a number of high-profile pilot groups and is playing a significant role in enabling their efforts to improve and extend community maintained chemical reference information. James D. Myers received his B.A. in Physics from Cornell University in 1985 and his Ph.D. in Chemistry from the University of California at Berkeley in 1993. He is currently the Associate Director for Collaborative Technologies at the National Center for Supercomputing Applications (NCSA) at the University of Illinois, Urbana Champaign. Dr. Myers is the lead investigator on the U.S. Department of Energy (DOE) sponsored Scientific Annotation Middleware project (http://www.scidac.org/SAM/) (scientific content management, semantic annotation, and records functionality) and is serving as the Chief Technical Officer for the DOE-sponsored Collaboratory for Multiscale Chemical Science (CMCS) project. His is also the lead architect for the Mid-America Earthquake Center's MAEViz hazard risk management collaboratory and co-lead of NCSA's Collaborative Large-scale Engineering Analysis Network for Environmental Research (CLEANER) related cybercollaboratory effort. Open source software developed by Dr. Myers and his colleagues including the electronic laboratory notebook (ELN) and the Collaborative Research Environment (CORE) real-time collaboration environment have been downloaded from the Pacific Northwest National Laboratory (PNNL) Collaboratory website (http://collaboratory.pnl.gov) by thousands of researchers and educators. Due to space limitations, individual bios for all 28 authors are not shown. The CMCS project is led by Dr. Larry Rahn (rahn@sandia.gov) at Sandia National Laboratories. The team includes combustion researchers and computer science researchers and developers at five DOE National Laboratories (Argonne, Lawrence Livermore, Los Alamos, Pacific Northwest, and Sandia National Laboratories), the National Institute of Standards and Technology, Massachusetts Institute of Technology, and the University of California, Berkeley. Current contact information and biographic information for team members is available at http://cmcs.org/team.php.