Rare-earth nickelates RNiO3: thin films and heterostructures

This review stands in the larger framework of functional materials by focussing on heterostructures of rare-earth nickelates, described by the chemical formula RNiO₃ where R is a trivalent rare-earth R  =  La, Pr, Nd, Sm, …, Lu. Nickelates are characterized by a rich phase diagram of structural and physical properties and serve as a benchmark for the physics of phase transitions in correlated oxides where electron-lattice coupling plays a key role. Much of the recent interest in nickelates concerns heterostructures, that is single layers of thin film, multilayers or superlattices, with the general objective of modulating their physical properties through strain control, confinement or interface effects. We will discuss the extensive studies on nickelate heterostructures as well as outline different approaches to tuning and controlling their physical properties and, finally, review application concepts for future devices.

In vitro antimicrobial activity of extracts and isolated constituents of Rubus ulmifolius

The antimicrobial activity on bacteria and fungi of increasing polarity extracts of Rubus ulmifolius and that of some isolated constituents, quercetin-3-O-beta-D-glucuronide; kaempferol-3-O-beta-D-glucuronide, gallic acid, ferulic acid and tiliroside was evaluated. The phenolic and tannins fractions showed an high antimicrobial activity.

Farnesoid X receptor inhibits tamoxifen-resistant MCF-7 breast cancer cell growth through downregulation of HER2 expression

Tamoxifen (Tam) treatment is a first-line endocrine therapy for estrogen receptor-α-positive breast cancer patients. Unfortunately, resistance frequently occurs and is often related with overexpression of the membrane tyrosine kinase receptor HER2. This is the rationale behind combined treatments with endocrine therapy and novel inhibitors that reduce HER2 expression and signaling and thus inhibit Tam-resistant breast cancer cell growth. In this study, we show that activation of farnesoid X receptor (FXR), by the primary bile acid chenodeoxycholic acid (CDCA) or the synthetic agonist GW4064, inhibited growth of Tam-resistant breast cancer cells (termed MCF-7 TR1), which was used as an in vitro model of acquired Tam resistance. Our results demonstrate that CDCA treatment significantly reduced both anchorage-dependent and anchorage-independent epidermal growth factor (EGF)-induced growth in MCF-7 TR1 cells. Furthermore, results from western blot analysis and real-time reverse transcription-PCR revealed that CDCA treatment reduced HER2 expression and inhibited EGF-mediated HER2 and p42/44 mitogen-activated protein kinase (MAPK) phosphorylation in these Tam-resistant breast cancer cells. Transient transfection experiments, using a vector containing the human HER2 promoter region, showed that CDCA treatment downregulated basal HER2 promoter activity. This occurred through an inhibition of nuclear factor-κB transcription factor binding to its specific responsive element located in the HER2 promoter region as revealed by mutagenesis studies, electrophoretic mobility shift assay and chromatin immunoprecipitation analysis. Collectively, these data suggest that FXR ligand-dependent activity, blocking HER2/MAPK signaling, may overcome anti-estrogen resistance in human breast cancer cells and could represent a new therapeutic tool to treat breast cancer patients that develop resistance.

The red wine phenolics piceatannol and myricetin act as agonists for estrogen receptor alpha in human breast cancer cells

Previous epidemiological reports have suggested that red wine intake is associated with beneficial health effects due to the ability of certain phytochemical components to exert estrogen-like activity. It has been also documented that estrogens induce the proliferation of hormone-dependent breast cancer cells by binding to and transactivating estrogen receptor (ER) alpha, which in turn interacts with responsive DNA sequences located within the promoter region of target genes. In order to provide further insight into the positive association between wine consumption and the incidence of breast carcinoma in postmenopausal women, we have evaluated the estrogenic properties of two abundant wine-derived compounds, named piceatannol (PIC) and myricetin (MYR), using as model systems the hormone-sensitive MCF7 and the endocrine-independent SKBR3 breast cancer cells. On the basis of our experimental evidence PIC and MYR may contribute to the estrogenicity of red wine since: (1) they transactivate endogenous ER alpha; (2) they activate the agonist-dependent activation function (AF) 2 of ER alpha and ER beta in the context of the Gal4 chimeric proteins; (3) they rapidly induce the nuclear immunodetection of ER alpha; (4) they regulate the expression of diverse estrogen target genes; (5) they compete with 17beta-estradiol for binding to ER alpha and ER beta; and--as a biological counterpart of the aforementioned abilities--(6) they exert stimulatory effects on the proliferation of MCF7 cells. Hence, the estrogenic activity of PIC and MYR might be considered at least as a potential factor in the association of red wine intake and breast tumors, particularly in postmenopausal women.

Volatile compounds from three cultivars of Olea europaea from Italy

The chemical compositions of the volatile fractions from three Olea europaea L. cultivars (Leccino, Frantoio, and Cipressino) were examined by GC and GC-MS. The results showed that the cultivars can be distinguished on the basis of the volatile fraction compositions.

Striped nanoscale phase separation at the metal-insulator transition of heteroepitaxial nickelates

Nucleation processes of mixed-phase states are an intrinsic characteristic of first-order phase transitions, typically related to local symmetry breaking. Direct observation of emerging mixed-phase regions in materials showing a first-order metal–insulator transition (MIT) offers unique opportunities to uncover their driving mechanism. Using photoemission electron microscopy, we image the nanoscale formation and growth of insulating domains across the temperature-driven MIT in NdNiO₃ epitaxial thin films. Heteroepitaxy is found to strongly determine the nanoscale nature of the phase transition, inducing preferential formation of striped domains along the terraces of atomically flat stepped surfaces. We show that the distribution of transition temperatures is a local property, set by surface morphology and stable across multiple temperature cycles. Our data provide new insights into the MIT of heteroepitaxial nickelates and point to a rich, nanoscale phenomenology in this strongly correlated material.

Probing the evolution of mixed-phase states in materials offers unique insights into the microscopic mechanism of phase transitions. Here, Mattoni et al. report imaging of nanoscale formation and growth of insulating domains across the metal-insulator transition in NdNiO₃ thin films, uncovering a rich interplay between structural and electronic degrees of freedom.

Estrogen receptor beta binds Sp1 and recruits a corepressor complex to the estrogen receptor alpha gene promoter

Human estrogen receptors alpha and beta are crucially involved in the regulation of mammary growth and development. Normal breast tissues display a relative higher expression of ER beta than ER alpha, which drastically changes during breast tumorogenesis. Thus, it is reasonable to suggest that a dysregulation of the two estrogen receptor subtypes may induce breast cancer development. However, the molecular mechanisms underlying the potential opposing roles played by the two estrogen receptors on tumor cell growth remain to be elucidated. In the present study, we have demonstrated that ER beta overexpression in breast cancer cells decreases cell proliferation and down-regulates ER alpha mRNA and protein content, along with a concomitant repression of estrogen-regulated genes. Transient transfection experiments, using a vector containing the human ER alpha promoter region, showed that elevated levels of ER beta down-regulated basal ER alpha promoter activity. Furthermore, site-directed mutagenesis and deletion analysis revealed that the proximal GC-rich motifs at -223 and -214 are critical for the ER beta-induced ER alpha down-regulation in breast cancer cells. This occurred through ER beta-Sp1 protein-protein interactions within the ER alpha promoter region and the recruitment of a corepressor complex containing the nuclear receptor corepressor NCoR, accompanied by hypoacetylation of histone H4 and displacement of RNA-polymerase II. Silencing of NCoR gene expression by RNA interference reversed the down-regulatory effects of ER beta on ER alpha gene expression and cell proliferation. Our results provide evidence for a novel mechanism by which overexpression of ER beta through NCoR is able to down regulate ER alpha gene expression, thus blocking ER alpha's driving role on breast cancer cell growth.

The impact of drug interactions and polypharmacy on antimicrobial therapy in the elderly

Infectious diseases are more prevalent in older people than in younger adults, and represent a major healthcare issue in older populations. Indeed, infections in the elderly are often associated with higher morbidity and mortality, and may present atypically. Additionally, older patients are generally treated with polypharmacy regimens, which increase the likelihood of drug-drug interactions when the prescription of an antimicrobial agent is needed. A progressive impairment in the functional reserve of multiple organs may affect either pharmacokinetics or pharmacodynamics during aging. Changes in body composition occurring with advancing age, reduced liver mass and perfusion, and reduced renal excretion may affect either pharmacokinetics or pharmacodynamics. These issues need to be taken into account when prescribing antimicrobial agents to older complex patients taking multiple drugs. Interventions aimed at improving the appropriateness and safety of antimicrobial prescriptions have been proposed. Educational interventions targeting physicians may improve antimicrobial prescriptions. Antimicrobial stewardship programmes have been found to reduce the length of hospital stay and improve safety in hospitalized patients, and their use in long-term care facilities is worth testing. Computerized prescription and decision support systems, as well as interventions aimed at improving antimicrobial agents dosage in relation to kidney function, may also help to reduce the burden of interactions and inherent costs.

Aromatase messenger RNA is derived from the proximal promoter of the aromatase gene in Leydig, Sertoli, and germ cells of the rat testis

It has long been recognized that individual cell types within the testes possess the capacity to synthesize estrogen. A number of studies on different species have demonstrated that the levels of aromatase expression and the patterns of regulation are distinct between the different cell types of the testes. Whereas a variety of promoters have been shown to contribute to the patterns of aromatase expression in different cell lineages, studies using ovarian RNA, testis RNA, and Leydig cell tumor lines have demonstrated that the same promoter (promoter II) was used in each. Recent experiments using potent aromatase inhibitors or analysis of animals in which the genes encoding the estrogen receptor-alpha (ER-alpha) or the aromatase, P450, are defective, have confirmed the importance of local estrogen formation in normal testicular function. In order to permit experiments to identify the elements controlling aromatase expression in the individual cell compartments of the testes, we prepared RNA from purified preparations of Leydig, Sertoli, and germ cells. Using specific oligonucleotide primers, the sites of initiation of the aromatase mRNA were determined using rapid amplification of cDNA ends (RACE) and nucleotide sequence analysis of the resulting cDNA fragments. Our results indicate that aromatase mRNA is derived from the proximal promoter (PII) of the aromatase gene in each of the major cell types of the rat testes.

Peroxisome proliferator-activated receptor gamma inhibits follicular and anaplastic thyroid carcinoma cells growth by upregulating p21Cip1/WAF1 gene in a Sp1-dependent manner

Peroxisome proliferator-activated receptor gamma (PPARgamma) has been demonstrated to be anti-neoplastic against various human tumors. The aim of this study was to delineate the molecular mechanism underlying PPARgamma ligand rosiglitazone (BRL) antiproliferative effects in follicular WRO and anaplastic FRO human thyroid carcinoma cells. BRL upregulated the p21Cip1/WAF1 levels in the two thyroid cancer cells, while did not modify the p53 protein content. Different evidences indicate that the p21Cip1/WAF1 upregulation by BRL requires a functional PPARgamma, since it was reversed by silencing PPARgamma and pretreatment with GW9662, an irreversible PPARgamma antagonist. Transient transfection assays showed that BRL triggered the transcriptional activity of p21Cip1/WAF1 promoter gene in a p53-independent way, being a p21Cip1/WAF1 promoter construct deleted in the p53 sites still activated by BRL. The Sp1 inhibitor mithramycin silenced the p21Cip1/WAF1 promoter activity suggesting an important role of Sp1 in mediating BRL activation. The electrophoretic mobility shift and chromatin immunoprecipitation (ChIP) assays evidenced a functional interaction between PPARgamma and Sp1 in regulating p21Cip1/WAF1. Intriguingly, ChIP analysis revealed in the p21Cip1/WAF1 gene promoter an increased recruitment of the RNA Pol II associated with an increased histone H3 acetylation and a reduced H3 methylation. The biological event, consistent with PPARgamma-induced WRO and FRO cell growth inhibition, was reversed by p21Cip1/WAF1 antisense oligonucleotides and was confirmed by increasing the PPARgamma expression, suggesting a crucial role exerted by p21Cip1/WAF1 in PPARgamma action. Our results further candidate BRL as a potential agent able to inhibit tumor progression of follicular and anaplastic thyroid carcinoma.

Bergapten induces ER depletion in breast cancer cells through SMAD4-mediated ubiquitination

ERα function is crucial for the development of normal mammary gland as well as in the process of progression of breast cancer cells. Signals that target receptor levels contribute to regulate estrogens effects in the cells. An intricate cross-regulation has been documented between ERα and TGF-β down-stream molecules: SMAD2, SMAD3, and SMAD4, that can bind ERα and regulate their signaling. Thus, identification of natural anticancer drugs able to influence the latter molecule might provide alternative choices for breast cancer treatment. Taking into account our previous published data we wanted to study the effect of 5-Methoxypsoralen (bergapten) on ERα and on TGF-β pathway. We reported that bergapten, a coumarin containing compound, effectively depletes ERα in MCF-7 breast cancer sensitive cells and in tamoxifen-resistant clone. The decrease of ERα protein after bergapten treatment results from the ubiquitine-proteasome pathway as demonstrated by the use of MG-132. IP experiments with ER antibody, demonstrated that the protein has physical interaction with SMAD4 and poly-ubiquitine and the amount of ubiquitinated receptor, linked to SMAD4, is greater under bergapten. The crucial role played by SMAD4, in this process, emerges from the observation that in breast cancer cells, silencing of SMAD4, resulted in increased expression of endogenous ERα in both control and bergapten-treated cells, compared to wild- type cells. The same results were confirmed in siRNA TGF-β RII cells. The results suggest a novel negative regulation of ERα by TGF-β/SMAD4 in breast cancer cells and indicate that the SMAD4 protein is involved in the degradation of ERα induced by bergapten. We propose that bergapten may efficiently act as a natural antitumoral agent, able to deplete ERα from breast cancer tamoxifen-sensitive and resistant cells, thereby retraining the effect of membrane signals targeting ERα and in such way its mitogenic potentiality.

Gastrointestinal parasites of coyotes (Canis latrans) in the metropolitan area of Calgary, Alberta, Canada

Disease ecology is a relevant but relatively unexplored subject of research in urban coyotes ( Canis latrans Say, 1823). In fact, this carnivore may play a role in the circulation of parasites that can have implications on the health of humans and domestic dogs, but can also be affected by pathogens transmitted from domestic reservoirs. To investigate the gastrointestinal parasites of urban coyotes in Calgary, Alberta, Canada, we analyzed 61 carcasses and 247 fecal samples collected within the metropolitan area, including city parks, in 2009–2010. We found nine parasite taxa: Toxascaris leonina (Linstow, 1902), Uncinaria stenocephala (Railliet, 1884), Ancylostoma caninum (Ercolani, 1859), Pterygodermatites affinis (Jägerskiöld, 1904), Trichuris vulpis (Froelich, 1789), Echinococcus multilocularis Leuckart, 1863, Taenia crassiceps (Zeder, 1800), genus Giardia Kunstler, 1882, and genus Cystoisospora Frenkel, 1977. Factors related to coyote ecology, habitat characteristics, and dog management likely influence the community of coyote parasites in an urban environment, and need to be taken into account to assess the actual role of this carnivore in the maintenance of parasites in the city landscape. Further research is needed to assess the current risk for transmission of potentially zoonotic parasites (e.g., E. multilocularis, T. crassiceps, Giardia sp.) among coyotes, dogs, and humans.

In vitro antimicrobial activity of extracts and isolated constituents of Geum rivale

The antimicrobial activity of extracts of Geum rivale (Rosaceae) and that of some isolated constituents, on bacteria and fungi, was evaluated. The activity was concentrated in the triterpenes fraction and, for gram+ and gram- bacteria, also in the flavonoids fraction.

Interfacial Control of Magnetic Properties at LaMnO3/LaNiO3 Interfaces

The functional properties of oxide heterostructures ultimately rely on how the electronic and structural mismatches occurring at interfaces are accommodated by the chosen materials combination. We discuss here LaMnO3/LaNiO3 heterostructures, which display an intrinsic interface structural asymmetry depending on the growth sequence. Using a variety of synchrotron-based techniques, we show that the degree of intermixing at the monolayer scale allows interface-driven properties such as charge transfer and the induced magnetic moment in the nickelate layer to be controlled. Further, our results demonstrate that the magnetic state of strained LaMnO3 thin films dramatically depends on interface reconstructions.

Helminths of grizzly bears (Ursus arctos) and American black bears (Ursus americanus) in Alberta and British Columbia, Canada

Between May 2011 and June 2013, we collected the carcasses and gastrointestinal tracts of 40 American black bears (Ursus americanus Pallas, 1780) and 13 grizzly bears (Ursus arctos L., 1758) from populations of Alberta and British Columbia, Canada. Specimens were examined for helminths, which were identified to the species level by applying an integrated morphological and molecular approach. Our goal was to investigate parasite biodiversity and infection parameters in the sampled grizzly and black bears. We found seven parasite taxa: Dirofilaria ursi Yamaguti, 1941, Baylisascaris transfuga (Rudolphi, 1819), Uncinaria rauschi Olsen, 1968, Uncinaria yukonensis (Wolfgang, 1956), Taenia arctos Haukisalmi, Lavikainen, Laaksonen and Meri, 2011, Diphyllobothrium dendriticum (Nitzsch, 1824), and Diphyllobothrium nihonkaiense Yamane, Kamo, Bylund and Wikgren, 1986. The statistical significance of infection prevalence, intensity, and abundance for each helminth species was assessed relative to host species, gender, age class, sampling season, and location. This is the first unequivocal report of the potentially zoonotic tapeworms D. dendriticum and D. nihonkaiense in North American bears. Furthermore, we provide insight into the biology and ecology of the nematodes B. transfuga, D. ursi, and species of Uncinaria Frölich, 1789, and enrich the information available on the recently described tapeworm T. arctos.

Invasive species and their parasites: eastern cottontail rabbit Sylvilagus floridanus and Trichostrongylus affinis (Graybill, 1924) from Northwestern Italy

The eastern cottontail Sylvilagus floridanus is a native American lagomorph. Within the genus Sylvilagus, the eastern cottontail is the species with the widest distribution. From 1950s, the species was introduced to several European countries. A rapid territorial expansion of the introduced eastern cottontails has been observed in many areas of Italy. The eastern cottontail has been demonstrated to play a main role as carrier of exotic parasites. To date, three nematode species, exotic in Italian ecosystems, have been reported from introduced S. floridanus. However, its parasite fauna biodiversity is richer in native populations of the American continent. The aim of this work was to further investigate the gastrointestinal parasites of S. floridanus, to evaluate the potential presence of other exotic species. During 2010, 101 hosts were examined, and three nematodes were collected from their digestive tract. Two parasite species (Obeliscoides cuniculi, Trichostrongylus calcaratus) were already reported in Italy; the isolation of Trichostrongylus affinis is instead the first report of this nematode in Italy and in Europe as a whole. This study wants to highlight the great risks related to the introduction of allochthonous species. The impact of the invasion by alien animal species may be particularly severe for public and animal health, due to the potential introduction of new pathogens. The good number of exotic parasites found in introduced eastern cottontails, together with the few sanitary surveys carried out, suggests that an epidemiological survey, with specimens from multiple localities on a wider geographic range, could lead to interesting findings on parasites of native and alien lagomorphs in Europe.

The effect of dietary calcium intake on bone mineral density in healthy adolescent girls and young women in southern Italy

BACKGROUND

The association between forearm bone mineral areal density (BMD) and dietary calcium, anthropometric characteristics, puberty, and physical activity was studied for the first time in 200 girls (aged 11-15 years) and 100 women (aged 20-23 years) living in Southern Italy.

METHODS

The BMD was assessed by dual energy x-ray absorptiometry at ultradistal (ud) and proximal (pr) radial sites and dietary calcium was evaluated using Food Frequency Questionnaires and detailed 3-day food records.

RESULTS

For population samples grouped according to low and high calcium intake levels, forearm densities were quite similar among both girls and women. Independently of calcium intake, girls displayed strong correlations between ud/pr-BMD and age, bone age, weight, height and BMI. Furthermore, in girls of similar age and BMI, radial densities were substantially increased following menarche. Positive relationships between weight, BMI and both ud/pr-BMD were only evident in women with high calcium intake.

CONCLUSIONS

This study showed that different calcium intake values do not appear to affect forearm mineral densities at the ages investigated, however puberty represents the major event in radial bone mass acquisition during adolescence.

Critical years and stages of puberty for radial bone mass apposition during adolescence

The acquisition of radial mineral density was evaluated in relation to anthropometric characteristics, menarche status, calcium intake and physical activity in a healthy young female population (200 girls and 100 women, respectively aged 11-16 yrs and 20-24 yrs) living in an area of Southern Italy. We performed bone mineral density (BMD) by dual energy X-ray absorptiometry on the ultradistal and middistal radius. Dietary calcium intake was evaluated by a detailed Food Frequency Questionnaire and confirmed by a 3-day record. A questionnaire on energy expenditure was used to assess physical activity in each participant. Morning blood samples were drawn from fasting girls to measure 25-hydroxycalciferol (25 OH-D). We found current calcium above the levels reported by Recommended Dietary Allowances (RDA) in only 31% of women and 6% of girls. BMD steadily increased up to the age of 16 and was increased in postmenarcheal girls compared to premenarcheals of the same pubertal stage. Bone density was also significantly related to age, weight and height in postmenarcheal adolescents, while in girls before and after menarche, no relation was observed between radial BMD and calcium intake or physical activity. In the presence of comparable calcium-intake values recorded in pre- and in postmenarcheal girls, the latter subgroup displayed a marked increase of 25 OH-D serum levels. Our study revealed a calcium intake lower than the RDA in a large percentage of healthy girls and young women, and emphasized the importance of menarche occurrence in bone mass acquisition during pubertal development.

A case report: cervical pregnancy with placenta percreta an ultrasonic assisted diagnosis

A rare cervical pregnancy is reported, discussing the difficulty differentiating this condition from the cervical phase of an incomplete abortion. Placenta percreta further complicates this case. Ultrasound will give a firm diagnosis of cervical pregnancy and associated placenta percreta. Conservative and radical surgical care determined by vital signs are discussed.

Bone mineral density is inversely related to parathyroid hormone in adolescent girls

Preventive programs aimed at maximizing peak bone mass as a way of reducing the risk of osteoporotic fractures later in life should take into account the contribution of nutritional factors to bone mass accumulation in young age. The role of calcium and energy intakes on radial mineral density was investigated in 200 healthy girls (aged 11-15 yr) simultaneously evaluating serum changes of insulin-like growth factor-I (IGF-I), parathyroid hormone (PTH) and osteocalcin (OC). Dietary calcium and energy intakes were assessed by a 3-day food record method, bone mineral density (BMD) was performed at ultradistal (ud) and proximal (pr) radial sites using dual energy X-ray absorptiometry. Calcium consumption below the levels suggested by Dietary Reference Intakes in more than 80% of population studied was not related to BMD, which in turn markedly increased in post-compared to premenarcheal girls. Interestingly, in a multiple regression analysis PTH was inversely related to BMD after adjustment for calcium intake, bone age and menarche. Serum IGF-I was positively associated to energy intakes and bone age in girls before menarche, who exhibited the highest values of OC. Our data highlighted the role of food habits in modulating some hormonal response that might influence bone mineral apposition during adolescent age. Low calcium consumption associated to enhanced PTH values, if persisting, could be responsible for reduced rate of gain in bone mineral density. Thus, to optimize bone mineralization during the critical period of rapid body growth adequate intakes of calcium and energy should be recommended.