Influence of monovalent and divalent cations on the surface area of phosphatidylglycerol monolayers

A theory is presented on the electrostatic properties of the surface area of phosphatidyl-glycerol monolayers spreading at an air-water interface in the presence of monovalent and divalent cations. In the present theory, the adsorption of monovalent and divalent cations to the membranes is taken into account, besides the dissociation of protons, as a possible cause of the change of surface charge density with the variation of pH or ion concentrations. It is also pointed out that, in the presence of structure-making ions such as Li⁺ and Na⁺, the nearest-neighbour interactions between proton dissociation sites become important for the monolayers in the gel state to yield a sharp expansion of the surface area with the increase of pH. The present theory shows quantitative agreements with previously-observed data.     

Colonization status and community structure of arbuscular mycorrhizal fungi in the coniferous tree,Cryptomeria japonica,with special reference to root orders

Plant and Soil - In this study, we examine the rhizosphere processes influencing organic P (Po) utilization in soil with low inorganic P (Pi) availability and how they change with plant...     

New Endoscopic Indicator of Esophageal Achalasia: “Pinstripe Pattern”

ResultsThe prevalence rates of the above-mentioned findings (1–5) were 41.1%, 41.1%, 16.1%, 94.6%, and 43.9%, respectively. PSP was observed in 60.7% of achalasia, while none of the control showed positivity for PSP. PSP was observed in 26 (62.5%) of 35 cases with shorter history < 10 years, which usually lacks typical findings such as severe esophageal dilation and tortuosity. Inter-observer agreement level was substantial for food/liquid remnant (k = 0.6861) and PSP (k = 0.6098), and was fair for abnormal contraction and white change. The accuracy, sensitivity, and specificity for achalasia were 83.8%, 64.7%, and 100%, respectively.Conclusion“Pinstripe pattern” could be a reliable indicator for early discrimination of primary esophageal achalasia.     

The effectiveness of RNAi in Caenorhabditis elegans is maintained during spaceflight

Background

Overcoming spaceflight-induced (patho)physiologic adaptations is a major challenge preventing long-term deep space exploration. RNA interference (RNAi) has emerged as a promising therapeutic for combating diseases on Earth; however the efficacy of RNAi in space is currently unknown.

Methods

Caenorhabditis elegans were prepared in liquid media on Earth using standard techniques and treated acutely with RNAi or a vector control upon arrival in Low Earth Orbit. After culturing during 4 and 8 d spaceflight, experiments were stopped by freezing at −80°C until analysis by mRNA and microRNA array chips, microscopy and Western blot on return to Earth. Ground controls (GC) on Earth were simultaneously grown under identical conditions.

Results

After 8 d spaceflight, mRNA expression levels of components of the RNAi machinery were not different from that in GC (e.g., Dicer, Argonaute, Piwi; P>0.05). The expression of 228 microRNAs, of the 232 analysed, were also unaffected during 4 and 8 d spaceflight (P>0.05). In spaceflight, RNAi against green fluorescent protein (gfp) reduced chromosomal gfp expression in gonad tissue, which was not different from GC. RNAi against rbx-1 also induced abnormal chromosome segregation in the gonad during spaceflight as on Earth. Finally, culture in RNAi against lysosomal cathepsins prevented degradation of the muscle-specific α-actin protein in both spaceflight and GC conditions.

Conclusions

Treatment with RNAi works as effectively in the space environment as on Earth within multiple tissues, suggesting RNAi may provide an effective tool for combating spaceflight-induced pathologies aboard future long-duration space missions. Furthermore, this is the first demonstration that RNAi can be utilised to block muscle protein degradation, both on Earth and in space.     

Early stalked stages in ontogeny of the living isocrinid sea lily Metacrinus rotundus

The early stalked stages of an isocrinid sea lily, Metacrinus rotundus, were examined up to the early pentacrinoid stage. Larvae induced to settle on bivalve shells and cultured in the laboratory developed into late cystideans. Three‐dimensional (3D) images reconstructed from very early to middle cystideans indicated that 15 radial podia composed of five triplets form synchronously from the crescent‐shaped hydrocoel. The orientation of the hydrocoel indicated that the settled postlarvae lean posteriorly. In very early cystideans, the orals, radials, basals and infrabasals, with five plates each in the crown, about five columnals in the stalk, and five terminal stem plates in the attachment disc, had already formed. In mid‐cystideans, an anal plate appeared in the crown. Late cystideans cultured in the field developed into pentacrinoids about 5 months after settlement. These pentacrinoids shared many crown structures with adult sea lilies. On the other hand, many features of the stalk differed from those in adult isocrinids, while sharing many characteristics with the stalk of feather star pentacrinoids, including disc‐like proximal columnals, high and slender median columnals, synarthrial articulations developmentally derived from the symplexial articulations, limited formation of cirri only in the proximal columnal(s), and an attachment disc. On the basis of these findings, phylogenetic relationships among extant crinoid orders are discussed.     

Assignment of A and B Types of Monoamine Oxidase in NCB20 Hybrid Cells to Those of the Parental Cells by Peptide Mapping

The structures of [3H]pargyline-labeled, flavin-containing polypeptides of monoamine oxidase (MAO) from hybrid NCB20 cells, and their parental cells, A/J mouse brain cells and Chinese hamster brain cells, were analyzed and compared by using sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), and limited proteolysis and one-dimensional peptide mapping in SDS gels. After preincubation of mitochondrial preparations with deprenyl or clorgyline, the flavin-containing polypeptide of type A or type B MAO was selectively labeled with [3H]pargyline. SDS-PAGE of [3H]pargyline-labeled mitochondrial samples revealed that the polypeptide with apparent Mr of 62,000 was associated with type A activity in the three types of cells, and that the polypeptide with apparent Mr of 61,000 or 58,000 was associated with type B activity in Chinese hamster brain cells and NCB20 cells or A/J mouse brain cells, respectively. Chymotrypsin digestion of the [3H]pargyline-labeled polypeptides and the peptide mapping in SDS gels from A/J mouse and Chinese hamster brain cells produced identical map patterns between the two type A MAOs, almost the same map patterns (with the exception of one additional peptide fragment) between the two type B MAOs, and different map patterns between type A and type B MAOs. The results of identical treatments of the [3H]pargyline-labeled polypeptides of MAOs in NCB20 cells showed that type A and type B MAO in NCB20 cells were similar to type A MAO of A/J mouse and Chinese hamster brain cells and to type B MAO of Chinese hamster brain cells.(ABSTRACT TRUNCATED AT 250 WORDS)     

Interaction of DP-TAT-59, an active metabolite of new triphenylethylene-derivative (TAT-59), with estrogen receptors.

DP-TAT-59, (Z)-2-(4-(1-(4-hydroxyphenyl)-2-(4-isopropylphenyl)-1-butenyl) phenoxy)-N, N-dimethylethylamine, has been reported to inhibit estrogen-stimulated growth of MCF-7 cells as well as rat uterus at lower concentrations than the hydroxymetabolite of tamoxifen (4-OH-TAM). In the present study, the growth of mouse Leydig cell tumor, B-1F cells were also more effectively inhibited by DP-TAT-59 than 4-OH-TAM. Additionally, the expression of estrogen responsive element ligated CAT gene transfected into B-1F cells was also suppressed by DP-TAT-59. Thus, the interaction of DP-TAT-59 with estrogen receptor (ER) was characterized and compared with that of 4-OH-TAM using immature rat and bovine uteri. The dissociation constant of DP-TAT-59 to ER of immature rat uterus was 0.24 nM and was similar to that of 4-OH-TAM (Kd = 0.20 nM) and estradiol (Kd = 0.29 nM). Using sucrose density gradients, the sedimentation constant of DP-TAT-59 with bovine uterus was 4.9S, which was similar to that of estradiol (5.1S) and 4-OH-TAM (5.3S). However, the elution profile of the DP-TAT-59-ER complex from a DEAE-Sephadex column was different for both estradiol-and 4-OH-TAM-ER complexes. These results suggest that ER forms different complexes with DP-TAT-59 than estradiol or 4-OH-TAM, while the ER binding affinity of these compounds are similar to each other.     

Electrical Potentials during Gravitropism in Bean Epicotyls

An apparatus for measuring simultaneously the surface electrical potentials along epicotyl was developed to study the largely bending situation by gravity. Potentials increased on the upper side and decreased on the lower side after the horizontal placement. The time course of electrical changes consisted of two components which correspond to growth movements observed during gravitropism.     

Coupling of the Cloned μ-Opioid Receptor with the ω-Conotoxin-Sensitive Ca2+ Current in NG108-15 Cells

Abstract: Voltage-dependent Ca²⁺ currents were measured in NG108-15 neuroblastoma × glioma hybrid cells transformed to express the rat μ-opioid receptor by the whole-cell configuration of the patch-clamp technique with Ba²⁺ as charge carrier. A μ-opioid receptor-selective agonist, [ d -Ala², N -Me-Phe⁴,Gly⁵-ol]enkephalin caused significant inhibition of voltage-dependent Ca²⁺ currents in μ-receptor-transformed NG108-15 cells but not in nontransfected or vector-transformed control cells. On the other hand, a δ-opioid receptor-selective agonist, [ d -penicillamine², d -penicillamine⁵]enkephalin, induced inhibition of voltage-dependent Ca²⁺ currents in both control and μ-receptor-transformed cells, which is mediated by the δ-opioid receptor expressed endogenously in NG108-15 cells. The inhibition of voltage-dependent Ca²⁺ currents induced by [ d -Ala², N -Me-Phe⁴,Gly⁵-ol]enkephalin and [ d -penicillamine², d -penicillamine⁵]enkephalin was reduced by pretreatment of the cells with pertussis toxin or ω-conotoxin GVIA. These results indicate that the μ-opioid receptor expressed from cDNA functionally couples with ω-conotoxin-sensitive N-type Ca²⁺ channels through the action of pertussis toxin-sensitive G proteins in NG108-15 cells.