Tuning the Multiferroic Properties of BiFeO_{3} under Uniaxial Strain.

More than twenty years ago, multiferroic compounds combining in particular magnetism and ferroelectricity were rediscovered. Since then, BiFeO_{3} has emerged as the most outstanding multiferroic by combining at room temperature almost all the fundamental or applicative properties that may be desired: electroactive spin wave excitations called electromagnons, conductive domain walls, or a low band gap of interest for magnonic devices. All these properties have so far only been discontinuously strain engineered in thin films according to the lattice parameter imposed by the substrate. Here we explore the ferroelectricity and the dynamic magnetic response of BiFeO_{3} bulk under continuously tunable uniaxial strain. Using elasto-Raman spectroscopy, we show that the ferroelectric soft mode is strongly enhanced under tensile strain and driven by the volume preserving deformation at low strain. The magnonic response is entirely modified with low energy magnon modes being suppressed for tensile strain above pointing out a transition from a cycloid to an homogeneous magnetic state. Effective Hamiltonian calculations show that the ferroelectric and the antiferrodistortive modes compete in the tensile regime. In addition, the homogeneous antiferromagnetic state becomes more stable compared to the cycloidal state above a +2% tensile strain close to the experimental value. Finally, we reveal the ferroelectric and magnetic orders of BiFeO_{3} under uniaxial strain and how the tensile strain allows us to unlock and to modify in a differentiated way the polarization and the magnetic structure.

Continent-wide survey reveals massive decline in African savannah elephants.

African elephants (Loxodonta africana) are imperiled by poaching and habitat loss. Despite global attention to the plight of elephants, their population sizes and trends are uncertain or unknown over much of Africa. To conserve this iconic species, conservationists need timely, accurate data on elephant populations. Here, we report the results of the Great Elephant Census (GEC), the first continent-wide, standardized survey of African savannah elephants. We also provide the first quantitative model of elephant population trends across Africa. We estimated a population of 352,271 savannah elephants on study sites in 18 countries, representing approximately 93% of all savannah elephants in those countries. Elephant populations in survey areas with historical data decreased by an estimated 144,000 from 2007 to 2014, and populations are currently shrinking by 8% per year continent-wide, primarily due to poaching. Though 84% of elephants occurred in protected areas, many protected areas had carcass ratios that indicated high levels of elephant mortality. Results of the GEC show the necessity of action to end the African elephants' downward trajectory by preventing poaching and protecting habitat.

Estradiol inhibits the estrone sulfatase activity in normal and cancerous human breast tissues.

It is well accepted that estradiol (E2) plays an important role in the genesis and evolution of breast cancer. Quantitative evaluation indicates that in human breast tumor, estrone sulfate (E1S) 'via sulfatase' is a much more likely precursor for E2 than is androstenedione 'via aromatase'. In previous studies, it was demonstrated that in isolated MCF-7 and T-47D breast cancer cell lines, estradiol can block estrone sulfatase activity. In the present study, the effect of E2 was explored using total normal and cancerous breast tissues. This study was carried out with post-menopausal patients with breast cancer. None of the patients had a history of endocrine, metabolic or hepatic diseases or had received treatment in the previous 2 months. Each patient received local anaesthetic (lidocaine 1%) and two regions of the mammary tissue were selected: (A) the tumoral tissue and (B) the distant zone (glandular tissue) which was considered as normal. Samples were placed in liquid nitrogen and stored at -80 degrees C until enzyme activity analysis. Breast cancer histotypes were ductal and post-menopausal stages were T2. Homogenates of tumoral or normal breast tissues (45-75 mg) were incubated in 20 mM Tris-HCl, pH 7.2 with physiological concentrations of [3H]-E1S (5 x 10(-9)M) alone or in the presence of E2 (5 x 10(-5) to 5 x 10(-7) M) during 30 min or 3 h. E1S, E1 and E2 were characterized by thin layer chromatography and quantified using the corresponding standard. The sulfatase activity is significantly more intense with the breast cancer tissue than normal tissue, since the concentration of E1 was 3.20 +/- 0.15 and 0.42 +/- 0.07 pmol/mg protein, respectively after 30 min incubation. The values were 27.8 +/- 1.8 and 3.5 +/- 0.21 pmol/mg protein, respectively after 3 h incubation. Estradiol at the concentration of 5 x 10(-7) M inhibits this conversion by 33% and 31% in cancerous and normal breast tissues, respectively and by 53% and 88% at the concentration of 5 x 10(-5) M after 30 min incubation. The values were 24% and 18% for 5 x 10(-7) M and 49% and 42% for 5 x 10(-5) M, respectively after 3h incubation. It was observed that [3H]-E1S is only converted to [3H]-E1 and not to [3H]-E2 in normal or cancerous breast tissues, which suggests a low or no 17beta-hydroxysteroid dehydrogenase (17beta-HSD) Type 1 reductive activity in these experimental conditions. In conclusion, estradiol is a strong anti-sulfatase agent in cancerous and normal breast tissues. This data can open attractive perspectives in clinical trials using this hormone.

Serum ferritin in stroke: a marker of increased body iron stores or stroke severity?

To evaluate the effect of body iron stores on the vulnerability of the brain to ischemia, a focal permanent brain ischemia was induced by photothrombotic occlusion of cortical vessels in rats with or without chronic treatment with iron dextran (25 mg iron/kg, every other day for 20 days, intraperitoneally). Iron dextran induced systemic iron overload as evidenced by high ferritin (Ft) ( x 5) and total iron levels ( x 3) in serum as well as increased Ft expression in the liver and heart. Conversely, neither serum free iron levels nor Ft expression in the brain were changed by iron dextran. Finally, infarct volume was not modified by iron dextran. In addition, induction of ischemia in rats treated with FeCl(3) (560 microg iron/kg, intravenously) as a means of increasing serum free iron levels during the ischemic period did not enlarge infarct volume. We then explored the effect of brain ischemia itself on serum Ft by measuring serum Ft before and after induction of brain ischemic insults with different neurologic outcomes in rats (brain embolization with microspheres, photothrombotic occlusion of cortical vessels, four-vessel occlusion). Serum Ft levels were found higher at day 1 after ischemia than before ischemia only in rats subjected to the most severe insult (brain embolization). In conclusion, our study showed that increased body iron stores do not increase the vulnerability of the brain to ischemia and that brain ischemia, if severe, results in the elevation of serum Ft levels.

Comparison of estrogen concentrations, estrone sulfatase and aromatase activities in normal, and in cancerous, human breast tissues.

In the present study, the concentrations of estrone (E(1)), estradiol (E(2)) and their sulfates (E(1)S and E(2)S), as well as the sulfatase and aromatase activities, were evaluated in post-menopausal patients with breast cancer. Comparative studies of the evaluation of these parameters were carried out in (a) tumor tissue, (b) areas surrounding the tumor, and (c) areas distant from the tumor (glandular tissue) which were considered as normal tissue. The levels (in pm/g; mean +/- SEM) were: for E(1) in the (a) area: 320+/-95; in (b): 232+/-86; and in (c): 203+/-71; for E(2) in the (a) area: 388+/-106; in (b): 224+/-48; and in (c): 172+/-80; for E(1)S in the (a) area: 454+/-110; in (b): 259+/-90; and in (c): 237+/-65; for E(2)S in the (a) area:318+/-67; in (b): 261+/-72; and in (c): 232+/-75, respectively. The values of E(1)S and E(2) were significantly higher in the tumor tissue than in the area considered as normal. In all the tissues studied, the sulfatase activity was much higher than aromatase (130-200). In addition, the sulfatase levels were significantly higher in the peripheral and in the tumor tissue than in the area considered as normal. The levels of aromatase were significantly higher in tumoral than in normal tissue. The present data extend the "intracrine concept" for breast cancer tumors. The physiopathology and clinical significance as promoter parameters in breast cancer is to be explored.

Exogenous lipoid pneumonia: HRCT, MR, and pathologic findings.

The objective of this study was to describe high-resolution CT (HRCT) and MR findings of exogenous lipoid pneumonia and to correlate them with pathologic findings. A retrospective review of the medical records of our institution revealed seven patients with a diagnosis of lipoid pneumonia based on clinical data, chest films, bronchoalveolar lavage, and follow-up. Both HRCT and MR imaging were reviewed by two readers. Pathologic examination of the resected specimen or surgical biopsies were also reviewed in the four available cases. The HRCT findings were pulmonary consolidations (n = 6) with fatty (n = 3) or unspecific but low attenuation values (n = 3), areas of ground-glass opacities (n = 5), septal lines, and centrilobular interstitial thickening (n = 5). In five of the seven cases, a crazy-paving pattern of various spread was also present, either isolated (n = 1) or surrounding a pulmonary consolidation. In two cases traction bronchiectasis and cystic changes consistent with fibrosis were seen. At MR imaging (n = 2) a pulmonary consolidation of high signal intensity on T1-weighted image consistent with lipid content was present in one case. Pathologic examination (n = 4) showed the coexistence of lobules with lesions of various ages, sometimes in contiguous lobules, within the same patient. Recent lesions were those with alveolar fill-in by spumous macrophages and almost normal alveolar walls and septae. In more advanced lesions, lobules were filled in with larger vacuoles often surrounded by inflammatory infiltrates of alveolar walls, bronchiolar walls, and septa. The oldest lesions were characterized by fibrosis and parenchymal distortion around large lipid-containing vacuoles. The HRCT findings reflect pathologic findings in exogenous lipoid pneumonia. Although non-specific, consolidation areas of low attenuation values and crazy-paving pattern are frequently associated in exogenous lipoid pneumonia and are indicative of the diagnosis.

Effects of Org OD14 (Livial) and its metabolites on 17 beta-hydroxysteroid dehydrogenase activity in hormone-dependent MCF-7 and T-47D breast cancer cells.

It is well recognized that estradiol (E2) is one of the most important hormones supporting the growth and evolution of breast cancer. Consequently, to block this hormone before it enters the cancer cell, or in the cell itself, has been one of the main targets in recent years. In the present study we explored the effect of Org OD14 (active substance in Livial) and its metabolites (Org 30126, Org 4094, Org OM38) on the 17 beta-hydroxysteroid dehydrogenase (17 beta HSD) activity of MCF-7 and T-47D human breast cancer cells. Using physiological doses of estrone ([3H]-E1: 5 x 10(-9) M) this estrogen is converted in a great proportion to E2 in both cell lines. After 24 hours, Org OD14 significantly inhibits this transformation in a dose-dependent manner, by 32 and 73% at 5 x 10(-7) M and 5 x 10(-5) M respectively, in T-47D cells; the effect is similar in MCF-7 cells. Among the three Org OD14 metabolites tested, Org 4094 and Org 30126 (3 alpha- and 3 beta-hydroxy metabolites) are more potent than their precursor, and Org OM-38 (4-ene isomer) is the weakest of the three steroids. The IC50 values were 0.79, 1.98, 7.12, and 22.84 microM in MCF-7 cells for Org 4094, Org 30126, Org OD14, and Org OM-38, respectively, and 4.83, 1.44, 2.03, and 35.25 microM, respectively, in T-47D cells. As Org OD14 and two of its metabolites, Org 30126 and Org 4094, also strongly decrease the conversion of estrone sulphate to estradiol in the hormone-dependent MCF-7 and T-47D breast cancer cells, it is concluded that the inhibition provoked by these steroids on the enzymes (estrone sulphatase and 17 beta-HSD) involved in the local biosynthesis of the biologically active estrogen estradiol, may reduce the risk of breast cancer in postmenopausal women during long-term hormone replacement treatment with Livial.

Effect of Org OD14 (LIVIAL) and its metabolites on human estrogen sulphotransferase activity in the hormone-dependent MCF-7 and T-47D, and the hormone-independent MDA-MB-231, breast cancer cell lines.

The concentration of estrogen sulphates (ES) is particularly high in tumoural breast tissues in post-menopausal women. It is well known that during the post-menopausal phase the levels of circulating estrogens are very low, suggesting the local production of these hormones in the breast cancer tissue itself. Breast cancer cells possess all the enzymes involved in the last steps of estradiol (E2) formation, as well as in its transformation (e.g.: sulphotransferase). As ES are not biologically active, the formation of this conjugate is an important transformation pathway in the control of E2. Consequently, it was interesting to investigate the factors which regulate the sulphotransferase activity. In the present study, we explored the effect of Org OD14; the active substance in Livial, and of its main metabolites (Org 4094, Org 30126, Org OM-38) on the estrogen sulphotransferase activity in the hormone-dependent: MCF-7, T-47D, and hormone-independent: MDA-MB-231, human breast cancer cell lines. After 24 hours incubation at 37 degrees C of physiological concentrations of estrone ([3H]-E1: 5 x 10(-9) mol/l), it was observed that the sulphotransferase activity is detectable in MCF-7 and T-47D cells, since the concentrations of ES found were 14.90 and 17.30 pmol/mg DNA, respectively, whereas in MDA-MB-231 cells the concentration of ES found was only 2.01 pmol/mg DNA. Sulphates are found exclusively in the culture medium, which suggests that as soon as the sulphate is biosynthesized it is secreted into the medium. Org OD14, Org 30126, and Org 4094 have a biphasic effect on sulphotransferase activity in the hormone-dependent cells only. At low doses (5 x 10(-8) mol/l) these compounds stimulate this enzyme by 63, 101, and 51%, respectively in the MCF-7 cells, and by 41, 102, and 80%, respectively in the T-47D cells. No stimulatory effect was detected with Org OM-38. At high concentrations (5 x 10(-5) mol/l) Org OD14 and its three metabolites inhibit the sulphotransferase activity in MCF-7 and T-47D cells by 50-70%. In conclusion, the stimulatory effect provoked at low doses by Org OD14 and its metabolites (Org 4094, Org 30126) on the estrogen sulphotransferase involved in the biosynthesis of the inactive estrogen sulphates in estrogen-dependent breast cancer cells, can contribute to the protection of breast tissue in postmenopausal women with hormone replacement therapy.

Effect of Medrogestone on 17beta-hydroxysteroid dehydrogenase activity in the hormone-dependent MCF-7 and T-47D human breast cancer cell lines.

Estradiol (E2) is one of the most important hormones supporting the growth and evolution of breast cancer. Consequently, to block this hormone before it enters the cancer cell, or in the cell itself, has been one of the main targets in recent years. In the present study we explored the effect of Medrogestone (Prothil) on 17beta-hydroxysteroid dehydrogenase (17beta-HSD) activities of the hormone-dependent MCF-7 and T-47D human breast cancer cell lines. Using physiological doses of estrone ([3H]-E1: 5 x 10(-9) mol/l) this estrogen is converted in a great proportion to E2 in both cell lines. After 24 h of the cell culture, Medrogestone significantly inhibits this transformation in a dose-dependent manner by 39% and 80% at 5 x 10(-8) M and 5 x 10(-5) M, respectively in T-47D cells; the effect is less intense in MCF-7 cells: 25% and 55% respectively. The IC50 values are 0.45 micromol/l in T-47D and 17.36 micromol/l in MCF-7 cells. It is concluded that the inhibition provoked by Medrogestone on the reductive 17beta-HSD activity involved in the local biosynthesis of the biologically active estrogen estradiol, may constitute a new therapeutic approach for the treatment of breast cancer.

High levels of anti-Campylobacter-flagellin IgA antibodies in breast milk.

Several studies have shown the beneficial role of immunity against enteric Campylobacter sp. Circulating antibodies against flagellin and possibly maternal antibodies seem to protect against intestinal colonization by Campylobacter. Milk from women in Central Africa (n = 120) and in France (n = 31) were investigated for the presence of anti-flagellin antibodies. Results showed that most French and all African milk possessed anti-flagellin IgA but not IgG. The titres of anti-flagellin IgA were elevated in colostrum and decreased in later milk. Specific activities were constant during lactation, suggesting constant antigenic stimulation. The fact that IgA but not IgG are elicited against flagellin could be due to an infection limited to the mucosal surface.

An analysis of molecular polymorphism of esterase M produced by motile Aeromonas strains.

The high levels of electrophoretic polymorphism of esterase M detected in eight distinct hybridization groups of motile Aeromonas raise questions of genetic homogeneity of the electromorphs. The 40 electromorphs detected fall in four Mr classes--75, 80, 90, and 110 kD--and one typical variant belonging to each of these classes was purified. The four purified esterases exhibited the same resistance to heat, to pH and to diisopropyl fluorophosphate, the same Km values for 1-naphthyl acetate and 1-naphthyl propionate (1 mM), and immunological cross-reactions. Within each class, the electromorphs appeared to be related in term of single amino acid substitutions as estimated from their comparative titration patterns. The titration curves of the four purified esterases were strictly parallel suggesting close structural similarities. Thus, despite considerable variation in their pI, MF, and Mr values, it seems likely that the variants of esterase M are the products of closely related loci originating from a common ancestral gene.

[Angiography of hepatic angiomatosis in Rendu-Osler disease. Apropos of 3 cases]. / Angioscanner de l'angiomatose hépatique dans la maladie de Rendu-Osler. A propos de 3 cas.

The hepatic changes in hereditary hemorrhagic telangiectasia (Rendu Osler's disease) involve the extra- and intrahepatic vessels (enlarged hepatic artery, arteriovenous fistulas and inhomogeneous perfusion) and the hepatic parenchyma (fibrosis, telangiectasic cirrhosis). From three observations with liver involvement and imaged with angiography and dynamic CT, the authors emphasize on the role of the latter for detection of these changes, mostly arteriovenous fistulas.

Isolation and properties of carboxylesterase P4 from Yersinia pseudotuberculosis.

The carboxylesterase P4 produced by Yersinia pseudotuberculosis was purified 330-fold by gel permeation and DEAE-trisacryl chromatography with a final yield of 21%. The apparent molecular weight, as determined by fast-protein liquid chromatography, was 45 kDa. The hydrolytic activity of esterase P4 was higher with the 1-naphthyl esters than with the 2-naphthyl esters of acetic, propionic and butyric acids. The apparent Km values were identical for 1-naphthyl acetate and 1-naphthyl propionate (0.15 mM). The enzyme was unstable at pH values below 5, but retained 80% of its initial activity after 30 min at 65 degrees C. It was unaffected by EDTA, eserine, tosyl-L-lysine chloromethylketone, iodoacetamide or 4-hydroxymercuribenzoate, but was strongly inhibited by low concentrations of diisopropyl fluorophosphate, suggesting the presence of serine in its active site. The purified enzyme gave a single precipitin line on Ouchterlony double immunodiffusion with homologous antiserum. This antiserum cross-reacted with the esterase bands E3 and E5 of Y. enterocolitica biotype 1, whereas there was no cross-reaction with the esterase bands produced by Y. enterocolitica biotypes 2 to 5, Y. intermedia, Y. frederiksenii, Y. kristensenii or Y. aldovae. The carboxylesterase P4 produced by Y. pestis was physicochemically, biochemically and immunologically indistinguishable from Y. pseudotuberculosis carboxylesterase P4. The latter enzyme and carboxylesterase B of Escherichia coli showed some biochemical similarities, but were antigenically unrelated. Our data confirm the relevance of esterases to phylogenetic and taxonomic studies of Enterobacteria.

Electrophoretic data in designing strategies for purification and identification of a highly polymorphic bacterial esterase.

We have purified a bacterial enzyme, designated esterase M, by tailoring an efficient and rapid strategy with information derived from titration curves of proteins in crude extract. The pH-dependent stability of the enzyme activity observed by titration pattern allowed an acidic pH treatment of extract and a cationic exchange chromatography at pH 4.1. These two steps were followed by an anionic exchange chromatography and a preparative electrophoresis. Thus, the enzyme was purified about 2000-fold within two days with a recovery of 13.3%. The electrophoretic variants of esterase M were investigated for their molecular relationship through the specific effect of antibodies on esterase electrophoretic pattern (immunosubtractive electrophoresis) which is applicable to large series of samples. By this process, we have demonstrated the presence of common antigenic determinants among the electromorphs of esterase M produced by the three species of motile Aeromonas.

CT and US findings in pancreatic ductal tumours. A report of an unusual case and review of the literature.

Pancreatic cystadenomas and cystadenocarcinomas are rare tumours usually occurring in women. The first symptoms are pain, occasionally associated with a palpable tumour in the left upper quadrant, and in rare cases the clinical and laboratory findings are suggestive of a pseudocyst. US shows a cystic neoplasm with a wall enclosing several polypoid areas. CT allows the diagnosis of the type of septa within the cyst and shows the extension of the lesion and calcifications into the wall. It also permits the assessment of the probable pathological complications associated with the tumour; therefore CT cannot differentiate cystadenoma from cystadenocarcinoma. The analysis of these different phenomena is based on one observation and a review of the literature.

Cavernous sinus syndrome due to lymphoma.

In both the cases described, painful ophthalmoplegia was the first indication of infiltration of the cavernous sinus by a lymphosarcoma. The onset of symptoms and the course of the disease were different in the two cases. CT scan which has been the crucial investigation for detecting lymphomas in the cavernous sinus, was normal in the early stages. Symptomatic remission could be obtained with treatment, although the prognosis remained poor.

[Computed x-ray tomography of abdominal lipoma and liposarcoma in adults. Apropos of 9 cases]. / La tomodensitométrie des lipomes et liposarcomes abdominaux de l'adulte. A propos de 9 cas.

CT scans were performed in 9 patients with fatty tumors of the abdomen: 2 lipomas and 7 liposarcoma. Of primary retroperitoneal origin, five tumors had extended intraperitoneally. Scanning images typical for each type of tumor are described: lipomas are very hypodense and well circumscribed, with thin intratumoral septa; liposarcomas are less hypodense and contain thick septa which may coalesce and form large nodules. Scanner imaging provides precise data on tumor extension and allows early detection of recurrences of these fatty tumors.

[Echography and computed x-ray tomography in the diagnosis and surveillance of hepatoblastoma. Apropos of 5 cases]. / Apport de l'échographie et de la tomodensitométrie dans le diagnostic et la surveillance des hépatoblastomes. A propos de cinq observations.

Ultrasound imaging and CT scans were performed in a homogeneous group of five patients with hepatoblastoma. Effectiveness in determining characteristics of the tumor mass and its location and possible vascular extension were compared for the two exploratory methods. Findings suggest that these two examinations are useful and complementary for the diagnosis and follow up of hepatoblastoma.

[Chronic vomiting disclosing a pheochromocytoma]. / Vomissements chroniques révélateurs d'un phéochromocytome.

Emesis is a common symptom in pheochromocytoma. It occurs in 26% of cases with permanent secretion, and 43% of cases with paroxystic secretion. Emesis may be the initial manifestation as in the present report of a 54-year-old female patient. For more than 15 years she experienced emesis which was ascribed to biliary dyskinesia. Bilateral pheochromocytoma was then diagnosed. With reference to this case, digestive manifestations of pheochromocytoma are reviewed.