Faint solar analogs: at the limit of no reddening

The flux distribution of solar analogs is required for calculating the spectral albedo of Solar System bodies such as asteroids and trans-Neptunian objects. Ideally a solar analog should be comparably faint as the target of interest, but only few analogs fainter than V = 9 were identified so far. Only atmospheric parameters equal to solar guarantee a flux distribution equal to solar as well, while only photometric colors equal to solar do not. Reddening is also a factor to consider when selecting faint analog candidates. We implement the methodology for identifying faint analogs at the limit of precision allowed by current spectroscopic surveys. We quantify the precision attainable for the atmospheric parameters effective temperature ($T_{eff}$), metallicity ([Fe/H]), surface gravity (log $g$) when derived from moderate low resolution (R=8000) spectra with S/N $\sim 100$. We calibrated $T_{eff}$ and [Fe/H] as functions of equivalent widths of spectral indices by means of the PCA regression. We derive log $g$, mass, radius, and age from the atmospheric parameters, Gaia parallaxes and evolutionary tracks. We obtained $T_{eff}$/[Fe/H]/log $g$ with precision of 97 K/0.06 dex/0.05 dex. We identify five solar analogs with $V\sim10.5$ (located at $\sim135$ pc): HIP 991, HIP 5811, HIP 69477, HIP 55619 and HIP 61835. Other six stars have $T_{eff}$ close to solar but slightly lower [Fe/H]. Our analogs show no evidence of reddening but for four stars, which present $E(B-V) \geq 0.06$ mag, translating to at least a 200 K decrease in photometric $T_{eff}$.Comment: Paper accepted. Fundamental parameters of the solar analogs are in Table

Periplasmic Expression of 4/7 α-Conotoxin TxIA Analogs in E. coli Favors Ribbon Isomer Formation – Suggestion of a Binding Mode at the α7 nAChR

Peptides derived from animal venoms provide important research tools for biochemical and pharmacological characterization of receptors, ion channels, and transporters. Some venom peptides have been developed into drugs (such as the synthetic omega-conotoxin MVIIA, ziconotide) and several are currently undergoing clinical trials for various clinical indications. Challenges in the development of peptides include their usually limited supply from natural sources, cost-intensive chemical synthesis, and potentially complicated stereoselective disulfide-bond formation in the case of disulfide-rich peptides. In particular, if extended structure-function analysis is performed or incorporation of stable isotopes for NMR studies is required, the comparatively low yields and high costs of synthesized peptides might constitute a limiting factor. Here we investigated the expression of the 4/7 alpha-conotoxin TxIA, a potent blocker at alpha 3 beta 2 and alpha 7 nicotinic acetylcholine receptors (nAChRs), and three analogs in the form of maltose binding protein fusion proteins in Escherichia coli. Upon purification via nickel affinity chromatography and release of the toxins by protease cleavage, HPLC analysis revealed one major peak with the correct mass for all peptides. The final yield was 1-2 mg of recombinant peptide per liter of bacterial culture. Two-electrode voltage clamp analysis on oocyte-expressed nAChR subtypes demonstrated the functionality of these peptides but also revealed a 30 to 100-fold potency decrease of expressed TxIA compared to chemically synthesized TxIA. NMR spectroscopy analysis of TxIA and two of its analogs confirmed that the decreased activity was due to an alternative disulfide linkage rather than the missing C-terminal amidation, a post-translational modification that is common in alpha-conotoxins. All peptides preferentially formed in the ribbon conformation rather than the native globular conformation. Interestingly, in the case of the alpha 7 nAChR, but not the alpha 3 beta 2 subtype, the loss of potency could be rescued by an R5D substitution. In conclusion, we demonstrate efficient expression of functional but alternatively folded ribbon TxIA variants in E. coli and provide the first structure-function analysis for a ribbon 4/7-alpha-conotoxin at alpha 7 and alpha 3 beta 2 nAChRs. Computational analysis based on these data provide evidence for a ribbon alpha-conotoxin binding mode that might be exploited to design ligands with optimized selectivity

Early diagnosis of bladder cancer through the detection of urinary tyrosine-phosphorylated proteins

BACKGROUND: A noninvasive, highly sensitive and specific urine test is needed for bladder cancer (BC) diagnosis and surveillance in addition to the invasive cystoscopy. We previously described the diagnostic effectiveness of urinary tyrosine-phosphorylated proteins (UPY) and a new assay (UPY-A) for their measurement in a pilot study. The aim of this work was to evaluate the performances of the UPY-A using an independent cohort of 262 subjects. METHODS: Urinary tyrosine-phosphorylated proteins were measured by UPY-A test. The area under ROC curve, cutoff, sensitivity, specificity and predictive values of UPY-A were determined. The association of UPY levels with tumour staging, grading, recurrence and progression risk was analysed by Kruskal–Wallis and Wilcoxon's test. To test the probability to be a case if positive at the UPY-A, a logistic test adjusted for possible confounding factor was used. RESULTS: Results showed a significant difference of UPY levels between patients with BC vs healthy controls. For the best cutoff value, 261.26 Standard Units (SU), the sensitivity of the assay was 80.43% and the specificity was 78.82%. A statistically significant difference was found in the levels of UPY at different BC stages and grades between Ta and T1 and with different risk of recurrence and progression. A statistically significant increased risk for BC at UPY-A ⩾261.26 SU was observed. CONCLUSIONS: The present study supplies important information on the diagnostic characteristics of UPY-A revealing remarkable performances for early stages and allowing its potential use for different applications encompassing the screening of high-risk subjects, primary diagnosis and posttreatment surveillance

A functional approach to the body condition assessment of lactating donkeys as a tool for welfare evaluation

Background. The breeding of lactating donkeys is increasing in Western Europe; with it the evaluation of body condition is growing in importance since it is considered a key principle for their welfare. However, assessment of body condition is a complex task, since several factors are involved. The aim of the present study is to investigate which animal-based indicators are the most reliable to describe the body condition of lactating donkeys. For this purpose, new animal-based indicators, which are easy to measure in field conditions (including body measurements, fatty neck score (FNS), dental score), are recorded and their relationship with BCS (a proxy measure for overall adiposity) was assessed. The ones that reveal an association with the BCS are included in an integrated principal component analysis to understand which are the most related to BCS. Methods. Fifty-three healthy lactating donkeys of various breeds, including 7 Martina Franca, 10 Ragusano, 2 Romagnolo and 34 crossbreeds, were evaluated. The animalbased indicators that were recorded were: length (OP, olecranon tuber-pinbone and SH, shoulder-hip), heart girth (HG), abdominal circumference (AC), neck length (NL), neck height (NH) and neck thickness (NT) at 0.50 and neck circumference (NC) at 0.25, 0.50 and 0.75, body condition score (BCS) and fatty neck score (FNS). The owners' evaluation of the BCS was also considered. A dental assessment was performed and the month of lactation and age of each animal was recorded. Results. No correlation was found between BCS and the other morphometric body measurements. On the contrary the FNS was correlated with the morphometric measurements of the neck (positive correlation to 0.50 NH and 0.50 NT, 0.50 NC, 0.75 mean NC, and negative correlation to the mean NC:NH and mean NC:NT, 0.50 NC:NT and 0.50 NC:NH ratios). A significant inverse relationship was identified between BCS and dental score. A Principal Component analysis (PCA) separated the BCS classes on the first principal component (PC1). PC1 revealed a meaningful positive correlation between the BCS and the neck measurements (NT, NH and FNS), with high positive loadings, while a negative correlation was found for dental abnormalities. The owners' evaluation of BCS was different from the expert evaluator' assessment, since they tended to give higher score that was slightly but significantly correlated to AC. Discussion. A new scoring system, called Fatty Neck Score (FNS), has been proposed for the judgement of the adiposity status of donkey neck. The results suggest that caregivers might use the proposed animal based indicators (BCS, FNS and dental scores) together as a tool for the evaluation of the body condition of lactating donkeys. Our findings highlight that caregivers need to be trained in order to be able to properly record these indicators. Ultimately use of these indicators may help to improve the welfare of lactating donkeys

Plasmodium falciparum-Infected Erythrocytes Induce Granzyme B by NK Cells through Expression of Host-Hsp70

In the early immune response to Plasmodium falciparum-infected erythrocytes (iRBC), Natural Killer (NK) cells are activated, which suggests an important role in innate anti-parasitic immunity. However, it is not well understood whether NK cells directly recognize iRBC or whether stimulation of NK cells depends mainly on activating signals from accessory cells through cell-to-cell contact or soluble factors. In the present study, we investigated the influence of membrane-bound host Heat shock protein (Hsp) 70 in triggering cytotoxicity of NK cells from malaria-naïve donors or the cell line NK92 against iRBC. Hsp70 and HLA-E membrane expression on iRBC and potential activatory NK cell receptors (NKG2C, CD94) were assessed by flow cytometry and immunoblot. Upon contact with iRBC, Granzyme B (GzmB) production and release was initiated by unstimulated and Hsp70-peptide (TKD) pre-stimulated NK cells, as determined by Western blot, RT-PCR and ELISPOT analysis. Eryptosis of iRBC was determined by Annexin V-staining. Our results suggest that presence of Hsp70 and absence of HLA-E on the membrane of iRBC prompt the infected host cells to become targets for NK cell-mediated cytotoxicity, as evidenced by impaired parasite development. Contact of iRBC with NK cells induced release of GzmB. We propose that following GzmB uptake, iRBC undergo eryptosis via a perforin-independent, GzmB-mediated mechanism. Since NK activity toward iRBC could be specifically enhanced by TKD peptide and abrogated to baseline levels by blocking Hsp70 exposure, we propose TKD as an innovative immunostimulatory agent to be tested as an adjunct to anti-parasitic treatments in vivo

Proteome Regulation during Olea europaea Fruit Development

Widespread in the Mediterranean basin, Olea europaea trees are gaining worldwide popularity for the nutritional and cancer-protective properties of the oil, mechanically extracted from ripe fruits. Fruit development is a physiological process with remarkable impact on the modulation of the biosynthesis of compounds affecting the quality of the drupes as well as the final composition of the olive oil. Proteomics offers the possibility to dig deeper into the major changes during fruit development, including the important phase of ripening, and to classify temporal patterns of protein accumulation occurring during these complex physiological processes.In this work, we started monitoring the proteome variations associated with olive fruit development by using comparative proteomics coupled to mass spectrometry. Proteins extracted from drupes at three different developmental stages were separated on 2-DE and subjected to image analysis. 247 protein spots were revealed as differentially accumulated. Proteins were identified from a total of 121 spots and discussed in relation to olive drupe metabolic changes occurring during fruit development. In order to evaluate if changes observed at the protein level were consistent with changes of mRNAs, proteomic data produced in the present work were compared with transcriptomic data elaborated during previous studies.This study identifies a number of proteins responsible for quality traits of cv. Coratina, with particular regard to proteins associated to the metabolism of fatty acids, phenolic and aroma compounds. Proteins involved in fruit photosynthesis have been also identified and their pivotal contribution in oleogenesis has been discussed. To date, this study represents the first characterization of the olive fruit proteome during development, providing new insights into fruit metabolism and oil accumulation process

MTH1 deficiency selectively increases non-cytotoxic oxidative DNA damage in lung cancer cells: more bad news than good?

Representative images of “Comets” and the corresponding intensity profiles, showing (i) ~ 5% Tail DNA damage, typical of the NSCLC cells treated with no siRNA or scramble siRNA, and analysed by regular Fpg-modified alkaline comet assay (0.8 U Fpg/gel); and (ii) comets showing ~ 10% tail DNA, typical of the NSCLC cells treated with MTH1 siRNA. Superimposed on the Comet images are the image analysis software (Komet 5.5, Andor Technology) determined boundaries demarcating the ‘Comet head’ (pink circle) and ‘tail extent’ (vertical orange line) (Barber RC, Hickenbotham P, Hatch T, Kelly D, Topchiy N, Almeida GM, et al. Radiation-induced transgenerational alterations in genome stability and DNA damage. Oncogene. 2006;25(56):7336–7342). % tail DNA = 100 - % head DNA; % head DNA = (integrated optical head intensity / (integrated optical head intensity + integrated optical tail intensity)) × 100. (PDF 1431 kb