Halophilic Carotenoids and Breast Cancer: From Salt Marshes to Biomedicine

Breast cancer is the leading cause of death among women worldwide. Over the years, oxidative stress has been linked to the onset and progression of cancer. In addition to the classical histological classification, breast carcinomas are classified into phenotypes according to hormone receptors (estrogen receptor—RE—/progesterone receptor—PR) and growth factor receptor (human epidermal growth factor receptor—HER2) expression. Luminal tumors (ER/PR-positive/HER2-negative) are present in older patients with a better outcome. However, patients with HER2-positive or triple-negative breast cancer (TNBC) (ER/PR/HER2-negative) subtypes still represent highly aggressive behavior, metastasis, poor prognosis, and drug resistance. Therefore, new alternative therapies have become an urgent clinical need. In recent years, anticancer agents based on natural products have been receiving huge interest. In particular, carotenoids are natural compounds present in fruits and vegetables, but algae, bacteria, and archaea also produce them. The antioxidant properties of carotenoids have been studied during the last years due to their potential in preventing and treating multiple diseases, including cancer. Although the effect of carotenoids on breast cancer during in vitro and in vivo studies is promising, clinical trials are still inconclusive. The haloarchaeal carotenoid bacterioruberin holds great promise to the future of biomedicine due to its particular structure, and antioxidant activity. However, much work remains to be performed to draw firm conclusions. This review summarizes the current knowledge on pre-clinical and clinical analysis on the use of carotenoids as chemopreventive and chemotherapeutic agents in breast cancer, highlighting the most recent results regarding the use of bacterioruberin from haloarchaea.     

Effect of colored shade nets on pepper powdery mildew (<Emphasis Type="Italic">Leveillula taurica</Emphasis>)

The effect of colored shade nets with different shade intensities and qualities of irradiation transmittance on pepper powdery mildew was tested in mini-plots and field experiments. Leaf coverage byLeveillula taurica and leaf shedding due to the disease were more severe in the shade, by up to 275% and 70%, respectively, than in the open field. Leaf coverage byL. taurica symptoms and leaf shedding from plants grown under 25% shade black nets were higher, by up to 70% and 180%, respectively, than under 40% shade nets. The color of the shade nets affected the intensity of photosynthetically active (PAR), ultra-violet (UV), blue, red and far red radiations, the UV/blue light ratio, and percent PAR and UV transmitted. The various nets suppressed the disease differently. Black, blue-silver, green and red nets were associated with lower levels of disease in the field experiments. The red net was also superior in the mini-plots. The other results from the mini-plots were not similar to those from the field, probably reflecting more intensive epidemic development in the mini-plots. No interaction between net type and cultivar was found when two cultivars were grown under the nets. Yield was higher under nets than in the open; nevertheless, the yield from plants grown under the 40% shade black net was not higher than that of the plants under the 25% black net, despite the significantly lower levels of disease at the higher shade intensity. B-quality pepper yield was significantly higher in the plots covered by 25% shade. Yield differences between the different colored nets were also not well correlated with disease levels, probably due to factors negating the direct effect of the nets on the plants and their yield. Implementation of either ‘friendly’ (Ampelomyces quisqualis AQ10/Trichoderma harzianum T39/ sulfur/ neem seed extract) or chemical (sulfur/ pyrifenox/ Polyoxin AL/ myclobutanil/ azoxystrobin) spray regimes successfully reduced disease severity under the different nets. There was no interaction between net type and spray regime. Thus, growing sweet pepper under shade nets results in increased yields and also in higher powdery mildew severity. Disease is negatively associated with the rate of shading and is variably affected by the quality of light filtered through the different colored shade nets. http://www.phytoparasitica.org posting May 8, 2007.     

Effects of saline irrigation water and heat waves on potato production in an arid environment

Production of spring potato (Solanum tuberosum L. cv. Désirée) on a deep sandy soil in the central highland of the Negev desert of Israel under drip irrigation with saline water (up to 6.2 dS m⁻¹) was studied in the years 1992–1997. The objective of the study was to determine the effects of saline water irrigation on potato production in an arid environment with special focus on the interactions with weather conditions. Although yields were often high, salinity effects were evident in some years. Thus 1992 and 1996 yields were 6–7 kg m⁻² and showed no significant effect of salinity, while a pronounced drop in yield with increasing salinity was observed in 1993 and 1994. Analysis of weather data for 1993–1994 suggests that the decline in yield was due to interactions between saline irrigation and prolonged heat wave events occurring during crop development. Further experimental work (1997) revealed that tuber yield was most sensitive to combined salt and heat stress when heat waves occurred at 40–60 days after emergence. The combined stress apparently leads to the collapse of mechanisms for avoiding salt accumulation in young expanding leaves, resulting in failure of vegetative growth recovery and a consequent reduction in the leaf area index and canopy functioning. The relationship between tuber sink demand and available photoassimilate supply at certain stages of plant development is discussed with reference to the ability of the potato plant to recover from the combined stress.     

Effect of dietary fructans and dexamethasone administration on the insulin response of ponies predisposed to laminitis

OBJECTIVE: To determine whether pasture, and specifically the addition of fructan carbohydrate to the diet, induces exaggerated changes in serum insulin concentration in laminitispredisposed (LP) ponies, compared with ponies with no history of the condition, and also to determine insulin responses to the dexamethasone suppression test. DESIGN: Prospective study. ANIMALS: 10 LP and 11 control adult nonobese mixed-breed ponies. PROCEDURES: Insulin-modified IV glucose tolerance tests were performed (5 ponies/group). In diet studies, ponies were kept on pasture and then changed to a hay diet (10 ponies/group). Second, ponies were maintained on a basal hay diet (4 weeks) before being fed a hay diet supplemented with inulin (3 g/kg/d [1.4 g/lb/d]). Serum insulin and plasma glucose concentrations were analyzed before and after dietary changes. Serum cortisol and insulin concentrations were also measured in a standard dexamethasone suppression test. RESULTS: The LP ponies were insulin resistant (median insulin sensitivity of 0.27 x 10(4) L min(-1) mU(-1) in LP ponies, compared with 0.64 x 10(4) L min(-1) mU(-1) in control ponies). Median insulin concentration in LP ponies was significantly greater than that in control ponies at pasture, decreased in response to feeding hay, and was markedly increased (5.5-fold) following the feeding of inulin with hay. The LP ponies had a greater increase in serum insulin concentration at 19 hours after dexamethasone administration (median, 222.9 mU/L), compared with control ponies (45.6 mU/L). CONCLUSIONS AND CLINICAL RELEVANCE: Nonobese ponies predisposed to develop laminitis had compensated insulin resistance, and this phenotype was revealed by feeding plant fructan carbohydrate or by dexamethasone administration.     

Bisdioxycalamenene: A Bis-Sesquiterpene from the Soft Coral Rhytisma fulvum fulvum

A dichloromethane extract of the soft coral Rhytisma fulvum fulvum collected in Madagascar afforded a novel compound possessing an unprecedented pentacyclic skeleton, bisdioxycalamenene (1), as well as seven known sesquiterpenes. The structures of the compounds were elucidated using 1D and 2D NMR techniques, as well as high-resolution mass spectrometry. The absolute configuration of 1 was determined using X-ray diffraction analysis and anomalous dispersion effects. The structure elucidation and a possible biogenesis of the compound are discussed.     

Hairpin-based virus resistance depends on the sequence similarity between challenge virus and discrete,highly accumulating siRNA species

Virus resistance can be effectively generated in transgenic plants by using the plant’s silencing machinery. To study the specificity of gene-silencing-based resistance, homozygous tobacco (Nicotiana tabacum L.) plants containing a 597-nt hairpin RNA construct of the Potato Virus Y (PVY) replicase sequence were challenged with a variety of PVY strains. The transgene-carrying tobacco line was immune to five potato PVY strains with high sequence similarity (88.3–99.5%) to the transgene. Infection with more distant tomato and pepper PVY field strains (86–86.8% sequence similarity) caused delayed symptom appearance in the transgenic tobacco. Transgene production of small interfering (si) RNA was detected by northern blot and measured using a custom-designed microarray for the detection of small RNAs. siRNA accumulation peaks were observed throughout the inverted-repeat transgene. In the resistance-breaking tomato and pepper strains there were nucleotide differences in the sequences correlated to siRNA transgene accumulation, indicating the role of siRNA specificity in resistance breaking. The log of transgene siRNA signal intensity increased with probe GC content, indicating that the accumulating siRNA molecules were GC-rich. Sequence similarity of highly accumulating siRNAs with the target virus strain appears to be important for both resistance and resistance-breaking characteristics.     

Removing Moisture Effect on Soil Reflectance Properties: A Case Study of Clay Content Prediction

Visible, near-infrared and shortwave-infrared (VNIR-SWIR) spectroscopy is an efficient approach for predicting soil properties because it reduces the time and cost of analyses. However, its advantages are hampered by the presence of soil moisture, which masks the major spectral absorptions of the soil and distorts the overall spectral shape. Hence, developing a procedure that skips the drying process for soil properties assessment directly from wet soil samples could save invaluable time. The goal of this study was twofold:proposing two approaches, partial least squares (PLS) and nearest neighbor spectral correction (NNSC), for dry spectral prediction and utilizing those spectra to demonstrate the ability to predict soil clay content. For these purposes, we measured 830 samples taken from eight common soil types in Israel that were sampled at 66 different locations. The dry spectrum accuracy was measured using the spectral angle mapper (SAM) and the average sum of deviations squared (ASDS), which resulted in low prediction errors of less than 8% and 14%, respectively. Later, our hypothesis was tested using the predicted dry soil spectra to predict the clay content, which resulted in R² of 0.69 and 0.58 in the PLS and NNSC methods, respectively. Finally, our results were compared to those obtained by external parameter orthogonalization (EPO) and direct standardization (DS). This study demonstrates the ability to evaluate the dry spectral fingerprint of a wet soil sample, which can be utilized in various pedological aspects such as soil monitoring, soil classification, and soil properties assessment.     

External reflection from omnidirectional dielectric mirror fibers

We report the design and fabrication of a multilayered macroscopic fiber preform and the subsequent drawing and optical characterization of extended lengths of omnidirectional dielectric mirror fibers with submicrometer layer thickness. A pair of glassy materials with substantially different indices of refraction, but with similar thermomechanical properties, was used to construct 21 layers of alternating refractive index surrounding a tough polymer core. Large directional photonic band gaps and high reflection efficiencies comparable to those of the best metallic reflectors were obtained. Potential applications of these fibers include woven fabrics for radiation barriers, spectral authentication of cloth, and filters for telecommunications.     

Season-induced changes in bovine sperm motility following a freeze-thaw procedure

Decreased conception rate of dairy cows in the summer is mainly associated with the deleterious effects of environmental thermal stress on the female reproductive tract. Here, we suggest that decreased reproductive performance might be partially due to inferior-quality semen. Semen from five representative bulls was collected in summer (August to September) and winter (December to January) and evaluated with a computerized sperm-quality analyzer for bulls (SQA-Vb). No seasonal effect was found in fresh ejaculate, but sperm examined post-thawing showed lower velocity, motility and progressive motility (P<0.04) in summer vs. winter samples. Element concentrations in the seminal plasma, determined by inductively coupled plasma-atomic emission spectrometry, differed between seasons, with higher (P<0.01) concentration values of K, Mg, Na and S elements in winter vs. summer samples. Therefore, season-induced alterations in seminal plasma element concentration should be taken into account when using an extender for cryopreservation. Acrosome integrity was assessed by a triple-fluorescence test using Hoechst 33342, fluorescein isothiocyanate-conjugated Pisum sativum agglutinin (FITC-PSA) and propidium iodide. Acrosome reaction was examined by a one-step staining method using FITC-PSA. The proportion of sperm cells with a damaged acrosome post-thawing tended to be higher (P<0.07) in semen collected during the summer vs. winter. Such alterations suggest that seasonal reductions in sperm function might also be involved in the decreased conception rate of dairy cows in summer.     

Spray treatments combined with climate modification for the management of Leveillula taurica in sweet pepper

The effects of several spray and climate treatments on Leveillula taurica were tested under controlled and commercial greenhouse conditions either alone or combined with a climate treatment. Ampelomyces quisqualis AQ10 inhibited the germination of conidia on leaves, but not on glass. Trichoderma harzianum T39 inhibited germination on both surfaces. Neither the examined biological control agents (BCAs) nor the two tested mineral oils (AddQ and JMS Stylet-Oil) affected the viability of conidia. Sulphur drastically limited the germination and viability of L. taurica. In experiments at 15–25°C, AQ10 alone reduced hyphal leaf colonisation at 25°C. T. harzianum T39 significantly reduced leaf colonisation at all temperatures but significantly reduced disease only at 20–25°C. The oils significantly reduced leaf colonisation and sulphur reduced both leaf colonisation and disease at all temperatures. Results were confirmed in an experimental greenhouse. In a field experiment, azoxystrobin, polyoxin AL, neem extract, and T39 were effective; sulphur was superior to them. Under severe epidemic conditions the disease had a negative impact on yield; late fungicide treatments at spring-time were found unnecessary. Chemical sprays applied in alternation was compared with the ‘friendly’ spray regime (alternation of Heliosoufre, T. harzianum T39 + JMS Stylet oil, A. quisqualis AQ10+AddQ oil and Neemgard) in two climates i.e. (i.) day warm climate and (ii.) regular (cool) day climate regimes. In the warm climate, there was no significant difference in the performance of the ‘friendly’ spray regime and the chemical spray regime. However, in the cooler climate, the ‘friendly’ spray programme was not as effective as the chemical spray programme. It was concluded that a change in the greenhouse climate may affect the development of powdery mildew and, at the same time, promote the activity of BCAs and render a pathogen more vulnerable to these control agents, allowing for better disease suppression.