MTT assay based inhibition analysis of A2780 cells proliferation using Mollugo nudicaulis Lam. extract with CXCR4 and HER2 expression

It is of interest to document the inhibition of A2780 cell proliferation using Mollugo nudicaulis Lam.(M.nudicaulis) extract by MTT assay and by monitoring the CXCR4 and HER2 expression through RT-PCR analysis. Results shown that the n-hexane extract of M.nudicaulis have anticancer activity IC₅₀ values of 32.46±0.92 µg/mL on A2780 cell lines. It is further found that the CXCR4 and HER2 mRNA and protein expression were significantly reduced in M.nudicaulis treated A2780 cell lines. Thus, the n-hexane extract of M.nudicaulis is a natural source of bioactive compounds as potential anticancer agents.     

Factors defining the functional coupling of bacteriorhodopsin and ATP synthase in liposomes

Optimal conditions for the co-reconstitution of bacteriorhodopsin and yeast mitochondria ATP synthase were determined. Reconstitution was achieved with a quick two-step procedure. Preparations obtained by this method displayed in optimal cases 2–3-times higher activities (up to 500 nmol ATP/min per mg protein) compared with maximal values reported in the literature, when light-driven ATP synthesis was measured under similar conditions. The final activities depended on the purification method used for the ATP synthase, and it is shown that the oligomycin-sensitive ATP hydrolysis activity was not a good measure for the ability of the ATP synthase preparations to perform ATP synthesis after co-reconstitution. Light-driven ATP synthesis activities depended also on the type of phospholipid used, soybean phospholipid giving the best results. A close relation to the bacteriorhodopsin proton pump activity was found. Using different phospholipids, different $\text{H}{}^{\mathrm{+}}\text{ATP}$ ratios were found, calculated from ATP synthesis activities and initial and steady-state light-driven proton pump activities. From this, together with the findings that the ATP synthase displayed the same ATP hydrolysis and ATP-³²P_i exchange activities with these different phospholipids used, it is concluded that the protein distribution for the two proteins among the liposomes is different relative to each other for the different phospholipids. The light-driven ATP synthesis activity did not correlate with the variation in leakiness of the membrane for protons when different phospholipids were used. An explanation is given by the finding that at high light intensities, the ATP synthesis became independent of the presence of protonophore.     

Detection of DNA sequences in Plasmodium berghei by means of in situ hybridization

A non-radioactive in situ hybridization technique, used to map unique DNA sequences to plant chromosomes, has been adapted for the localization of specific DNA sequences in nuclei of Plasmodium berghei. After hybridization using probes labeled with biotin-11-dUTP, the formed DNA/DNA hybrids were detected by fluorescence microscopy using a specific double-layer antibody technique. Besides its high resolution, this procedure is characterized by a high sensitivity, allowing the detection of a unique sequence as small as 2.5 kb.     

Can we believe judgements of human physical attractiveness?

A key question in attractiveness studies is the validity of the reported results outside the narrow confines of the experimental paradigm used. Does the range of physical features in a set of pictures used to test attractiveness judgements predict the individual ratings of each body? Or does each stimulus have an attractiveness value independent of the range of attractiveness found in the image set of which it is a part? An additional problem is that because participants are often shown a relatively large array of images in a short space of time, this may produce perceptual biases, which could cause a short-term shift in attractiveness preferences, which are not usually found in real-life mate choice decisions. To address this issue, we asked 20 participants (10 male and 10 female) to judge the attractiveness of 20 digital photographs of female bodies. We then asked a different set of 400 people (who had not seen the body pictures) to judge the attractiveness of one of the bodies from the set (so each body was rated in isolation by 10 male and 10 female participants). We then compared the attractiveness judgement each body received when seen independently versus when it was seen within the context of a set of bodies. The results showed no significant difference between the two conditions, which suggests that each body has an attractiveness value independent of the attractiveness of the other bodies with which it is viewed.     

Summer warming and increased winter snow cover affect Sphagnum fuscum growth, structure and production in a sub-arctic bog

Sphagnum mosses form a major component of northern peatlands, which are expected to experience substantially higher increases in temperature and winter precipitation than the global average. Sphagnum may play an important role in the responses of the global carbon cycle to climate change. We investigated the responses of summer length growth, carpet structure and production in Sphagnum fuscum to experimentally induced changes in climate in a sub‐arctic bog. Thereto, we used open‐top chambers (OTCs) to create six climate scenarios including changes in summer temperatures, and changes in winter snow cover and spring temperatures. In winter, the OTCs doubled the snow thickness, resulting in 0.5–2.8°C higher average air temperatures. Spring air temperatures in OTCs increased by 1.0°C. Summer warming had a maximum effect of 0.9°C, while vapor pressure deficit was not affected. The climate manipulations had strong effects on S. fuscum. Summer warming enhanced the length increment by 42–62%, whereas bulk density decreased. This resulted in a trend (P<0.10) of enhanced biomass production. Winter snow addition enhanced dry matter production by 33%, despite the fact that the length growth and bulk density did not change significantly. The addition of spring warming to snow addition alone did not significantly enhance this effect, but we may have missed part of the early spring growth. There were no interactions between the manipulations in summer and those in winter/spring, indicating that the effects were additive. Summer warming may in the long term negatively affect productivity through the adverse effects of changes in Sphagnum structure on moisture holding and transporting capacity. Moreover, the strong length growth enhancement may affect interactions with other mosses and vascular plants. Because winter snow addition enhanced the production of S. fuscum without affecting its structure, it may increase the carbon balance of northern peatlands.