Protective Effects of Inosine on Memory Consolidation in a Rat Model of Scopolamine-Induced Cognitive Impairment: Involvement of Cholinergic Signaling,Redox Status,and Ion Pump Activities

Neurochemical Research - This study investigated the effects of inosine on memory acquisition and consolidation, cholinesterases activities, redox status and Na+, K+-ATPase activity in a rat model...     

Cytotoxic and apoptotic effects of chalcone derivatives of 2‐acetyl thiophene on human colon adenocarcinoma cells

Recent studies report that chalcones exhibit cytotoxicity to human cancer cell lines. Typically, the form of cell death induced by these compounds is apoptosis. In the context of the discovery of new anticancer agents and in light of the antitumour potential of several chalcone derivatives, in the present study, we synthesized and tested the cytotoxicity of six chalcone derivatives on human colon adenocarcinoma cells. Six derivatives of 3‐phenyl‐1‐(thiophen‐2‐yl) prop‐2‐en‐1‐one were prepared and characterized on the basis of their ¹H and ¹³C NMR spectra. HT‐29 cells were treated with synthesized chalcones on two concentrations by three different incubation times. Cells were evaluated by cell morphology, Tetrazolium dye (MTT) colorimetric assay, live/dead, flow cytometry (annexin V) and gene expression analyses to determine the cytotoxic way. Chalcones 3‐(4‐bromophenyl)‐1‐(thiophen‐2‐yl)prop‐2‐en‐1‐one (C06) and 3‐(2‐nitrophenyl)‐1‐(thiophen‐2‐yl)prop‐2‐en‐1‐one (C09) demonstrated higher cytotoxicity than other chalcones as shown by cell morphology, live/dead and MTT assays. In addition, C06 induced apoptosis on flow cytometry annexin V assay. These data were confirmed by a decreased expression of anti‐apoptotic genes and increased pro‐apoptotic genes. Our findings indicate in summary that the cytotoxic activity of chalcone C06 on colorectal carcinoma cells occurs by apoptosis. Copyright © 2012 John Wiley & Sons, Ltd.     

An experimental and theoretical approach to determining linkages between geochemical variability and microbial biodiversity in seafloor hydrothermal chimneys

New experimental results of fluid–mineral reactions at hydrothermal conditions relevant to life demonstrate that key redox reactions involving iron, sulfur, and hydrogen remain at disequilibrium at 100 °C, even in a heterogeneous system and thus are energetically favorable for microbial metabolism. Predictions from geochemical models utilizing the experimental results and specific to two contrasting case studies from the East Pacific Rise were statistically characterized and correlated to the energetics of redox reactions available for intra‐chimney microbial populations. In general, predictions of available energy for autotrophic metabolism are largely similar between the mature and the nascent chimneys, although important differences still exist. Metabolic processes predicted by energetics exhibit the same trends observed in the field data for the mature chimney, but overestimate the diversity observed in the nascent chimney. Several combinations of redox reaction pairs are predicted to support mixed consortia, while some combinations appear to favor more versatile microbes capable of utilizing several reactions under rapidly changing environmental conditions within chimney walls. In addition, conditions favorable to elemental sulfur reduction and methanogenesis exhibit a negative control on the diversity of microbial populations within these chimney walls, whereas H₂S oxidation, elemental sulfur oxidation and the knallgas reaction are positively correlated with both abundance and diversity of micro‐organisms. Coupling field observations of both microbial diversity and geochemical heterogeneity with lab‐based experimental and theoretical modeling can facilitate translation of the observed genetic diversity into physiological diversity, thus enhancing understanding of linked phenomena of microbially induced biogeochemical transformations in complex heterogeneous systems.     

The Relationship Between Cell Size and Chloroplast Number in the Spores of a Moss, Polytrichum

The number of plastids per cell is positively correlated withcell size in immature, mature, and germinating spores, and injacket cells of antheridia. Cell enlargement occurs ahead ofplastid replication, and under normal circumstances cell sizedoes not limit plastid number. Plastid number increases in dimensionallystable cells (1) during early spore development, (2) when maturespores are incubated in chloramphenicol (CAP), and (3) after8 h incubation in the dark without inhibitors present. Cycloheximide(CHI) prevents replication but not swelling during early germination.Thus, an increase in plastid number does not always requirea change in cell size, and an increase in cell size is not alwaysaccompanied by an increase in plastid number. The findings arediscussed in relation to other results implicating phytochrome-mediatedcytoplasmic protein synthesis in plastid replication and nuclearcontrol of plastid replication.     

Identified taste bud cell proliferation in the perihatching chick [published erratum appears in Chem Senses 1998 Aug;23(4):459]

Developing taste buds in the anterior mandibular floor of perihatching chicks were studied by high voltage electron microscopic autoradiography in order to identify proliferating gemmal cell types. Montaged profiles of 29 taste buds in five cases euthanized between embryonic day 21 and posthatching day 2 were analyzed after a single [3H]thymidine injection administered on embryonic day 16, 17 or 18. Results showed that dark cells comprised 55% of identified (n = 900 cells) and 62% of labeled (n = 568 cells) gemmal cells as compared with light, intermediate, basal or perigemmal bud cells. Dark cells had both a greater (P < 0.05) number of labeled cells and a greater amount of label (grains/nucleus) than the other four bud cell types, irrespective of injection day. The nuclear area (micron 2) of dark cells was not significantly larger (P > 0.05) than that of the other gemmal cell types and therefore cannot account for the greater amount for label in the dark cells. Interestingly, only dark cells showed a positive correlation (P < 0.003) between amount of label and nuclear area. Results suggest that, during the perihatching period of robust cell proliferation, dividing dark cells may give rise primarily, but not exclusively, to dark cell progeny.      

Mobilization of lipid and carbohydrate reserves in the migratory grasshopper Melanoplus sanguinipes

Abstract. The North American migratory grasshopper Melanoplus sanguinipes Fabricius (Orthoptera: Acrididae) exhibits heritable variation in predisposition to make long-duration flights, and performance of long-duration flight enhances reproductive output. As a first step in understanding the physiological basis of these phenomena, we examined the mobilization of lipid and carbohydrate reserves during flight and in response to injection of extracts of the corpora cardiaca. Extract of conspecific corpora cardiaca elevates the concentration of haemolymph lipid. Both synthetic locust adipokinetic hormone I (AKH I) and synthetic Locusta migratoria AKH II raise the concentration of lipid in the haemolymph. However, although AKH I is more active than AKH II in locusts, dose-response curves for the two peptides are similar in M.sanguinipes. Neither extract of conspecific corpora cardiaca nor locust AKH I affects haemolymph carbohydrate in this species. Haemolymph carbohydrate and total glycogen reserves are Diminished by tethered flight; in contrast, haemolymph lipid is elevated by flight. Grasshoppers identified as presumptive migrants or non-migrants do not differ significantly in body composition. Total lipid reserves did not decrease measurably after extended flight, even though total reserves of carbohydrate do not appear to be sufficient to maintain the durations of flight performed.     

Polymerase Chain Reaction-Based Sex Identification in the Greater Roadrunner

Abstract: We determined a polymerase chain reaction (PCR)-based method to identify the sex of greater roadrunners (Geococcyx californianus). We found that previously reported primer combinations used in other bird species did not work reliably in roadrunners. However, a novel primer combination (P2-1237L) allowed for consistent and reliable sex identification of roadrunners. Conducting several PCR replicates per sample helped to identify occasional preferential amplification of the Z band that could occur in females (the heterogametic sex; i.e., WZ). Identifying the sex of individuals will allow for examination of sex-associated differences in home range size and habitat use, population demographics, and parenting behavior, as well as for a better understanding of the social system of roadrunners.     

An early Ordovician patelliform gastropod, Palaelophacmaea, reinterpreted as a coelenterate

Yochelson, Ellis L. & Stanley, George D., Jr. 1981 12 15: An early Ordovician patelliform gastropod, Palaelophacmaea , reinterpreted as a coelenterate. Lethaia , Vol. 15, pp. 323–330. Oslo. ISSN W24–1164.
The fossil Palaelophacmaea criola Donaldson, from the early Ordovician Stonehenge Formation of central Pennsylvania, was described as a patelliform gastropod. A reinterpretation of the type lot and study of a few additional specimens provide the basis for an alternative placement. Palaelophacmaea is here assigned to the Hydrozoa, as a possible chondrophore. It has an exceptionally thin shell or test and concentric but irregular corrugations. Cambrian univalve genera having a more or less circular outline that are currently assigned to the Gastropoda or Monoplacophora should be reexamined to see whether they have the features of fossil chondrophore coelenterates rather than those of molluscs. The late Cambrian Palaeoacmaea Hall & Whitfield is removed from the monoplacophoran Mollusca and left unassigned as to phylum. We judge that at least some early Cambrian species of Scenella are probably coelenterate remains. * Early Ordovician , Palaelophacmaea, Gastropoda, Monoplacophora, Hydrozoa .     

Early Expression of a Trypanosoma brucei VSG Gene Duplicated from an Incomplete Basic Copy

Intrachromosomal variant surface glycoprotein (VSG) genes in Trypanosoma brucei are expressed by a mechanism involving gene conversion. The 3'boundary of gene conversion is usually within the last 130 bp of the VSG gene, a region of partially conserved sequences. We report here the loss of the predominant telomeric A VSG gene in the cloned variant antigenic type (VAT) 5^A3, leaving only an intrachromosomal A VSG gene (the A-B gene). The nucleotide sequence of the A-B VSG gene reveals that it lacks the normal VSG 3' sequence. Surprisingly, we find cells expressing this A-B VSG gene in relapse populations arising from VAT 5^A3. Since the A VSG mRNAs from these cells have a normal 3' sequence, the incomplete A-B VSG gene must be expressed via a partial gene conversion that supplies the functional 3'end. Although the A-B VSG gene is no longer predominant like the telomeric A VSG gene, it is still expressed more frequently than other intrachromosomal VSG genes, suggesting that factors other than a telomeric location determine whether a VSG gene is expressed early in a serodeme.