Influence of local anesthetics on the phosphatidylcholine model membrane: small-angle synchrotron X-ray diffraction and neutron scattering study

The phase preferences of egg yolk phosphatidylcholine (EYPC) have been examined in the presence of tertiary amine anesthetics [2-(propyloxy)phenyl]-2-(1-piperidinyl)ethyl ester of carbamic acid (C3A) and [2-(heptyloxy)phenyl]-2-(1-piperidinyl)ethyl ester of carbamic acid (C7A, heptacaine). Using the synchrotron small-angle X-ray diffraction (SAXD), it is shown that the C3A anesthetic induces the cubic and hexagonal (H(I)) phases at 2 > or = C3A:EYPC > 0.5 and H2O:EYPC < or = 40 molar ratios. In contrast, longer alkyloxy chain homolog C7A has no effect on the bilayer arrangement of EYPC at C7A:EYPC < = 1 molar ratios as observed by SAXD in C7A + EYPC mixtures hydrated at H2O:EYPC < = 40 molar ratios, as well as in sonicated C7A + EYPC mixtures hydrated in excess water as proved by the small-angle neutron scattering (SANS). The bilayer thickness d(L) decreases and the bilayer C7A surface area SC7A increases with the increase of C7A:EYPC molar ratio. It is suggested that the ability of tertiary amine local anesthetics to influence the dL and SC7A values and EYPC polymorphism is caused by their effective molecular shape and by charge. The possibility that anesthetic molecules may exert some of their biological effects by virtue of these properties is discussed.     

Benthic zonation of the Eastern Gotland Basin, Baltic Sea

In this paper recent benthic biological studies in the Eastern Gotland Basin area of the Baltic Sea are summarised. A general pattern of vertical distribution of macrofauna is presented and special reference is made to sharp temporal changes in macrofauna of deeper, subhalocline areas of the basin. Information on faunal sediment reworking ability is compiled. The environmental factors driving benthic zonation are discussed and the vertical benthic zones are defined on the basis of their major biological and abiotic features. This analysis shows that due to sharp gradients in environment and clear differences in composition of macrofauna, the ecological functioning of the Eastern Gotland Basin benthic zones is clearly different. Therefore, in the biogeochemical models of benthic-pelagic interaction, these zones (together with water layers they underlie) should be treated separately, as different sub-systems.     

An ultrasensitive colorimetric method for the assay of endo-1,4-β-D-glucanase

Summary A colorimetric method for the assay of endo-1,4--D-glucanase from fungal cellulolytic systems which utilizes xyloglucan as substrate is described. The substrate forms a blue-green complex with I₂ which is lost upon its breakdown with the enzyme. The new assay is a simple one-step procedure and its sensitivity is comparable with that of viscometry.     

Evolution of ancient lake bivalves: the Lymnocardiinae (Cardiidae) of the Caspian Sea

The Caspian Sea as the largest continental water body in the world is known for its comparably high levels of biodiversity and endemism, also in mollusks. The evolution of a euryhaline taxon of cardiid bivalves, the Lymnocardiinae of the Ponto-Caspian region, remains unclear today. We studied material from the whole recent range of Lymnocardiinae (i.e., the Caspian, the Azov, and the Black Seas) using a LSU rDNA phylogeny aiming at (a) testing the monophyly of Lymnocardiinae and (b) determining the phylogenetic relationships within Cardiidae. Lymnocardiinae s.str. were monophyletic, i.e., a distinct group that included species of Hypanis, Didacna, and Monodacna. Lymnocardiinae as often understood, i.e., including Cerastoderma, are not monophyletic in our analysis and Cerastoderma should thus be transferred to Cardiinae. The Lymnocardiinae s.str. had a shallow tree topology and were poorly resolved. No clearcut biogeographical pattern could be derived from the phylogeny, i.e., species stemming from respective Ponto-Caspian regions, do not necessarily cluster together. We discuss a scenario of the evolutionary history and biogeographical (as well as taxonomic) implications. Given the complex history of the Ponto-Caspian region and the Caspian Sea in particular, the Lymnocardiinae would represent an interesting study object for addressing the consequences of environmental changes on biotic evolution at various spatial and temporal scales.     

Human embryonic stem cell-derived cells rescue visual function in dystrophic RCS rats

Embryonic stem cells promise to provide a well-characterized and reproducible source of replacement tissue for human clinical studies. An early potential application of this technology is the use of retinal pigment epithelium (RPE) for the treatment of retinal degenerative diseases such as macular degeneration. Here we show the reproducible generation of RPE (67 passageable cultures established from 18 different hES cell lines); batches of RPE derived from NIH-approved hES cells (H9) were tested and shown capable of extensive photoreceptor rescue in an animal model of retinal disease, the Royal College of Surgeons (RCS) rat, in which photoreceptor loss is caused by a defect in the adjacent retinal pigment epithelium. Improvement in visual performance was 100% over untreated controls (spatial acuity was approximately 70% that of normal nondystrophic rats) without evidence of untoward pathology. The use of somatic cell nuclear transfer (SCNT) and/or the creation of banks of reduced complexity human leucocyte antigen (HLA) hES-RPE lines could minimize or eliminate the need for immunosuppressive drugs and/or immunomodulatory protocols.     

Renal and endocrine changes in rats with inherited stress-induced arterial hypertension (ISIAH)

Hypertensive inbred rats (ISIAH; inherited stress-induced arterial hypertension) present with baseline hypertension (>170 mmHg in adult rats), but attain substantially higher values upon mild emotional stress. We aimed to characterize key parameters related to hypertension in ISIAH. Kidneys, adrenals, and systemic endocrine parameters were studied in ISIAH of different ages and compared to normotensive Wistar albino Glaxo (WAG) rats. Native organs were obtained for Western and PCR analysis. Perfusion-fixed organs were prepared for histopathology and quantitative histochemistry. Plasma renin and adrenal hormones were measured. Renal morphology was unaltered in ISIAH. The hypothalamic-pituitary-adrenocortical (HPA) axis was constitutively upregulated with enlarged adrenal cortices and enhanced plasma corticosterone levels. Plasma renin activity was not different between groups, whereas aldosterone levels were in part reduced. Juxtaglomerular NO synthase type 1, cyclooxygenase type 2, and renin expression were significantly reduced, whereas tubular gene products related to sodium transport (bumetanide-sensitive Na, K, 2Cl cotransporter type 2; thiazide-sensitive Na, Cl cotransporter; epithelial Na channel-α; 11β-hydroxysteroid dehydrogenase type 2) were increased. These data suggest enhanced volume conservation by the kidney. Our data define ISIAH as an attractive model for the renal components determining salt and water homeostasis in hypertension. The specific condition of a basally stimulated HPA axis is highlighted, including the option to study effects superimposed by emotional stress.     

Serum starvation: caveat emptor

Serum starvation is one of the most frequently performed procedures in molecular biology and there are literally thousands of research papers reporting its use. In fact, this method has become so ingrained in certain areas of research that reports often simply state that cells were serum starved without providing any factual details as to how the procedure was carried out. Even so, we quite obviously lack unequivocal terminology, standard protocols, and perhaps most surprisingly, a common conceptual basis when performing serum starvation. Such inconsistencies not only hinder interstudy comparability but can lead to opposing and inconsistent experimental results. Although it is frequently assumed that serum starvation reduces basal activity of cells, available experimental data do not entirely support this notion. To address this important issue, we studied primary human myotubes, rat L6 myotubes and human embryonic kidney (HEK)293 cells under different serum starvation conditions and followed time-dependent changes in important signaling pathways such as the extracellular signal-regulated kinase 1/2, the AMP-activated protein kinase, and the mammalian target of rapamycin. Serum starvation induced a swift and dynamic response, which displayed obvious qualitative and quantitative differences across different cell types and experimental conditions despite certain unifying features. There was no uniform reduction in basal signaling activity. Serum starvation clearly represents a major event that triggers a plethora of divergent responses and has therefore great potential to interfere with the experimental results and affect subsequent conclusions.     

Ultra short-term heart rate recovery after maximal exercise: relations to aerobic power in sportsmen

The main aim of the study was to investigate whether different levels of aerobic power influence heart rate (HR) responses during the first minute of recovery following maximal exercise in athletes. Thirty-two young male soccer players were recruited for the study during the final week of their training prior to [corrected] the competition. Following the maximal exercise on treadmill the participants were placed supine for 60 s of HR recording. The time between exercise cessation and the recovery HR measurement was kept as short as possible. At the end of exercise (i.e., the start of recovery), HRs were [corrected] was similar in both trials. At both 10 s and 20 s of recovery period, the players characterized by high aerobic power (> 60 ml/kg/ min) revealed significantly lower HR as compared to their sub-elite counterparts (< 50 ml/kg/min; P < 0.05). No differences between the groups were found at later stages of the analyzed post-exercise HR. The data suggest that the athletes characterized by high aerobic capacity could be better adapted to maximal exercise with faster recovery HR immediately following an exercise test. These results generally suggest that the aerobic power along with autonomic modulation might have played a role in the ultra short-term cardiovascular responses to all-out exercise.     

Proteomics profiling of microdissected low- and high-grade prostate tumors identifies Lamin A as a discriminatory biomarker

Proteomics screening methods for the identification of diagnostic and prognostic biomarkers in cancer are still lagging behind DNA- or RNA-based analysis. We used two-dimensional differential gel electrophoresis (2D-DIGE) in combination with laser capture microdissection (LCM) and MALDI-TOF/TOF mass spectrometry to determine differentially abundant proteins and candidate biomarkers in prostate cancer. Paired (benign and tumor) samples were isolated from 23 Gleason Score 6 (GS 6) and 23 Gleason Score 8 and higher (GS 8+) radical prostatectomy specimens and subjected to 2D-DIGE analysis. Minimal fluorescent dye labeling was applied and electrophoresis performed with triple samples (paired benign and tumor; internal control) for each case of tumor. Nineteen differently abundant proteins were identified by mass spectrometry and further validated. One half of them were associated with glycolysis and the Warburg effect; these were upregulated in tumors. The upregulation correlated with tumor dedifferentiation and might be relevant for selection of therapeutic strategies. Among the other proteins, heat shock protein 60 (HSP60) was significantly upregulated in tumor tissue compared to its benign counterpart. Furthermore, lamin A was statistically highly discriminatory between low and high Gleason score tumors and might serve as a new biomarker of tumor differentiation and prognosis.