Biomass distribution of different-aged needles in young and old Pinus cembra trees at highland and lowland sites

Conifer needles of different ages perform differently in ecophysiology. However, no study has investigated the biomass distribution of different-aged needles in a tree crown or/and a stand canopy. We carried out a study on young (∼50 years old) and old (∼200 years) Pinus cembra L. trees at highland (2100–2300 m a.s.l.) and lowland (570 m) sites in Switzerland. We found that both the young and the old trees living in the highlands had more needle biomass per tree than the same-aged trees of the same species living in the lowlands. This is mainly due to the greater longevity of needles in highland trees. It reflects the strategic responses of trees to low resource availability or high abiotic stress level. Having older needles increases the time that nutrients are resident in trees in less favorable environments, and compensates for shorter growing period in cold temperatures.     

THE FINE STRUCTURE OF GREEN BACTERIA

The fine structure of several strains of green bacteria belonging to the genus Chlorobium has been studied in thin sections with the electron microscope. In addition to having general cytological features typical of Gram-negative bacteria, the cells of these organisms always contain membranous mesosomal elements, connected with the cytoplasmic membrane, and an elaborate system of isolated cortical vesicles, some 300 to 400 A wide and 1000 to 1500 A long. The latter structures, chlorobium vesicles, have been isolated in a partly purified state by differential centrifugation of cell-free extracts. They are associated with a centrifugal fraction that has a very high specific chlorophyll content. In all probability, therefore, the chlorobium vesicles are the site of the photosynthetic apparatus of green bacteria.     

Antiproliferative activities of resveratrol and related compounds in human hepatocyte derived HepG2 cells are associated with biochemical cell disturbance revealed by fluorescence analyses

Resveratrol is a well known polyphenol largely produced in grapevine. It is a strong antioxidant and a free radical scavenger. It exhibits several beneficial effects for health including cancer. Resveratrol antioxidant activity is essential in the prevention of chemical-induced cancer by inhibiting initiation step of carcinogenesis process but it is also considered to inhibit cancer promotion and progression steps. While the effects of resveratrol on cancer cells are widely described, the data available on the antiproliferative potential of resveratrol derivatives remain weak. Nevertheless, resveratrol analogs could exhibit stronger potentials than the parent molecule. So, we compared the cellular effects of trans-resveratrol, trans-epsilon-viniferin and their respective acetate derivatives, as well as a polyphenol mixture extracted from grapevine shoots, called vineatrol. We studied their abilities to interfere with cell proliferation, their uptake and their effects on parameters of cellular state in human hepatoma cells (HepG2). Cell growth experiments show that resveratrol triacetate presents a slightly better antiproliferative potential than resveratrol. The dimer epsilon-viniferin,as well as its pentaacetate analog, is less powerful than resveratrol, although a similar uptake kinetics in cells. Interestingly, among the tested polyphenols, vineatrol is the most potent solution, indicating a possible synergistic effect of both resveratrol and epsilon-viniferin. We took advantage of the fluorescence properties of these compounds to evidence cellular uptake by using flow cytometry. In addition, by competition assay, we demonstrate that resveratrol triacetate enters in hepatic HepG2 cells by the same way as resveratrol. By autofluorescence in situ measurement we observed that resveratrol and related compounds induce deep changes in cells activity. These changes occur mainly by increasing NADPH cell content and the number of green fluorescent cytoplasmic granular structures which may be related to an induction of detoxifying enzyme mechanisms.     

ROC analysis of subcutaneous adipose tissue topography (SAT-Top) in female coronary heart disease patients and healthy controls

The aim of this study was to investigate whether subcutaneous adipose tissue topography (SAT-Top) is different in female CHD patients (n=26) and healthy controls (n=36) matched to age, body size, weight, and BMI. The thicknesses of SAT layers were measured by LIPOMETER at 15 specified body sites. To calculate the power of the different body sites to discriminate between CHD women and healthy controls, receiver operating characteristic (ROC) curve analysis was performed. For each parameter, sensitivity and specificity were calculated at different cutoff points. CHD women showed a significant decrease to 78.36% (p=0.012) at body site 11-front thigh, 73.10% (p=0.012) at 12-lateral thigh, 72.20% (p=0.009) at 13-rear thigh, 66.43% (p<0.001) at 14-inner thigh, and 49.19% (p<0.001) at 15-calf. The best discriminators analysed by ROC curves between female CHD patients and healthy controls turned out to be calf and inner thigh (optimal cut off values: calf: 3.85 mm and inner thigh: 11.15 mm). Stepwise discriminant analysis identified the body sites calf, lateral chest, and inner thigh as significant. In conclusion, information was obtained on the extent to which SAT thickness at each measured body site is able to discriminate between the two subject groups. The good discrimination results obtained for the present dataset are encouraging enough to recommend applying LIPOMETER SAT-Top measurements in further studies to investigate individual risks for CHD.     

Modulation of Escherichia coli DNA methyltransferase activity by biologically derived GATC-flanking sequences

Escherichia coli DNA adenine methyltransferase (EcoDam) methylates the N-6 position of the adenine in the sequence 5'-GATC-3' and plays vital roles in gene regulation, mismatch repair, and DNA replication. It remains unclear how the small number of critical GATC sites involved in the regulation of replication and gene expression are differentially methylated, whereas the approximately 20,000 GATCs important for mismatch repair and dispersed throughout the genome are extensively methylated. Our prior work, limited to the pap regulon, showed that methylation efficiency is controlled by sequences immediately flanking the GATC sites. We extend these studies to include GATC sites involved in diverse gene regulatory and DNA replication pathways as well as sites previously shown to undergo differential in vivo methylation but whose function remains to be assigned. EcoDam shows no change in affinity with variations in flanking sequences derived from these sources, but methylation kinetics varied 12-fold. A-tracts immediately adjacent to the GATC site contribute significantly to these differences in methylation kinetics. Interestingly, only when the poly(A) is located 5' of the GATC are the changes in methylation kinetics revealed. Preferential methylation is obscured when two GATC sites are positioned on the same DNA molecule, unless both sites are surrounded by large amounts of nonspecific DNA. Thus, facilitated diffusion and sequences immediately flanking target sites contribute to higher order specificity for EcoDam; we suggest that the diverse biological roles of the enzyme are in part regulated by these two factors, which may be important for other enzymes that sequence-specifically modify DNA.     

Arabidopsis SUC1 loads the phloem in suc2 mutants when expressed from the SUC2 promoter

Active loading of sucrose into phloem companion cells (CCs) is an essential process in apoplastic loaders, such as Arabidopsis or tobacco (Nicotiana sp.), and is even used by symplastic loaders such as melon (Cucumis melo) under certain stress conditions. Reduction of the amount or complete removal of the transporters catalysing this transport step results in severe developmental defects. Here we present analyses of two Arabidopsis lines, suc2-4 and suc2-5, that carry a null allele of the SUC2 gene which encodes the Arabidopsis phloem loader. These lines were complemented with constructs expressing either the Arabidopsis SUC1 or the Ustilago maydis srt1 cDNA from the SUC2 promoter. Both SUC1 and Srt1 are energy-dependent sucrose/H(+) symporters and differ in specific kinetic properties from the SUC2 protein. Transgene expression was confirmed by RT-PCRs, the subcellular localization of Srt1 in planta with an Srt1-RFP fusion, and the correct CC-specific localization of the recombinant proteins by immunolocalization with anti-Srt1 and anti-SUC1 antisera. The transport capacity of Srt1 was studied in Srt1-GFP expressing Arabidopsis protoplasts. Although both proteins were found exclusively in CCs, only SUC1 complemented the developmental defects of suc2-4 and suc2-5 mutants. As SUC1 and Srt1 are well characterized, this result provides an insight into the properties that are essential for sucrose transporters to load the phloem successfully.     

A Highlights from MBoC Selection: NAADP and the two-pore channel protein 1 participate in the acrosome reaction in mammalian spermatozoa

The functional relationship between the formation of hundreds of fusion pores during the acrosome reaction in spermatozoa and the mobilization of calcium from the acrosome has been determined only partially. Hence, the second messenger NAADP, promoting efflux of calcium from lysosome-like compartments and one of its potential molecular targets, the two-pore channel 1 (TPC1), were analyzed for its involvement in triggering the acrosome reaction using a TPCN1 gene–deficient mouse strain. The present study documents that TPC1 and NAADP-binding sites showed a colocalization at the acrosomal region and that treatment of spermatozoa with NAADP resulted in a loss of the acrosomal vesicle that showed typical properties described for TPCs: Registered responses were not detectable for its chemical analogue NADP and were blocked by the NAADP antagonist trans-Ned-19. In addition, two narrow bell-shaped dose-response curves were identified with maxima in either the nanomolar or low micromolar NAADP concentration range, where TPC1 was found to be responsible for activating the low affinity pathway. Our finding that two convergent NAADP-dependent pathways are operative in driving acrosomal exocytosis supports the concept that both NAADP-gated cascades match local NAADP concentrations with the efflux of acrosomal calcium, thereby ensuring complete fusion of the large acrosomal vesicle.     

Antibacterial endiandric acid derivatives from Beilschmiedia anacardioides

Three endiandric acid derivatives, beilschmiedic acids A, B and C were isolated from the stem bark of Beilschmiedia anacardioides together with the known β-sitosterol. Their structures were established by means of modern spectroscopic techniques. The relative configuration of compound 1 was determined by single crystal X-ray analysis. The antibacterial activities of compounds A,B,C were evaluated in vitro against five strains of microbes. Compound C showed strong activity against Bacillus subtilis, Micrococcus luteus and Streptococcus faecalis (MICs below 23 μM). This Compound was more active than the reference antibiotic ampicillin against B. subtilis and M. luteus.     

Discordances between follicle stimulating hormone (FSH) and anti-Müllerian hormone (AMH) in female infertility

Background

Follicle stimulating hormone (FSH) and anti-Müllerian hormone (AMH) represent the two most frequently utilized laboratory tests in determining ovarian reserve (OR). This study determined the clinical significance of their concordance and discordance in female infertility patients.

Methods

We investigated 366 consecutive infertility patients (350 reached IVF), excluding women with polycystic ovarian syndrome (PCOS). They were considered to have normal FSH and AMH if values fell within age-specific (as-) 95% confidence intervals (CI), and to suffer from diminished ovarian reserve (DOR) if FSH exceeded and/or AMH fell below those. The two hormones, thus, could be concordant (Group I), both normal (IA) or abnormal (IB), show normal AMH/abnormal FSH (Group II) or normal FSH/abnormal AMH (Group III). Oocyte yields, stratified for age categories, were then studied in each group as reflection of OR.

Results

Oocyte yields significantly decreased from groups IA to II to III and IB. Predictive values of as-FSH/AMH patterns changed, however, at different ages. Except at very young and very old ages, normal as-AMH better predicted higher oocytes yields than normal as-FSH, though above age 42 years normal as-FSH predicts good oocyte yields even with abnormally low AMH. Under age 42 discrepancies between as- FSH and as-AMH remain similarly predictive of oocyte yields at all ages.

Discussion

Concordances and discordances between as-FSH and as-AMH improve OR assessments and predictability of oocyte yields in IVF.