Molecular mechanisms and biological importance of Plasmodium falciparum erythrocyte rosetting

Rosetting, i.e. the spontaneous binding of uninfected to malaria infected erythrocytes and endothelial cytoadherence may hinder the blood flow and lead to serve Plasmodium falciparum malaria. Falciparum isolates obtained from unconscious patients all form rosettes and/or express a significantly higher man rosetting rate than isolates from patients with uncomplicated malaria. Furthermore, sera of patients with cerebral malaria are devoid of anti-rosetting activity while sera from patients with mild disease carry high levels of anti-rosetting antibodies. The presence of anti-rosetting antibodies also seems important for the efficient interaction of rosetting infected rbc and leucocytes. Two parasite derived rosetting ligands of Mr 22k and Mr28K named "rosettins, have been found on the surface of rosetting infected erythrocytes. CD36 has in at least some strains of parasites been found to function as a rosetting receptor on the uninfectederythrocyte. Heparin disrupts rosettes of P. falciparum in vitro and inhibits the sequestration of rosetting cells ex vivo. In conclusion, rosetting seems a crucial factor in the development of cerebral malaria and treatment of patients with anti-rosetting substances might become an effectivew adjunct in the treatment of severe malaria.

T lymphocytes and iron overload: novel correlations of possible significance to the biology of the immunological system

This paper is written in the context of our changing preception of the immunological system as a system with possible biological roles exceding the prevailung view of a system concerned principally with the defense against external pathogens. The view discussed here relates the immunological system inextricably to the metabolism of iron, the circulation of the blood and the resolution of the evolutionary paradox created by oxygen and iron. Indirect evidence for this inextricable relationship between the two systems can be derived from the discrepancy between the theoretical quasi-impossibility of the existence of an iron deficiency state in the adult and the reality of the WHO numbers of people in the world with iron deficiency anemia. With mounting evidence that TNF, IL-1, and T lymphocyte cytokines affect hemopoieisis and iron metabolism it is possible that the reported discrepancy is a reflection of that inextricable interdependence between the two systems in the face of infection. Further direct evidence for a relationship between T cell subset numbers and iron metabolism is presented from the results of a study of T cell populations in patients with hereditary hemochromatosis. The recent finding of a correlation between low CD8+ lymphocite numbers, liver demage associated with HCVpositivity and severity of iron overload in B-thalassemia major patients (umpublished data of RW Grandy; P. Giardina, M. Hilgartner) concludes this review.

A novel merozoite surface antigen of Plasmodium falciparum (MSP-3) identified by cellular-antibody cooperative mechanism antigenicity and biological activity of antibodies

We report the identification of a 48kDa antigen targeted by antibodies which inhibit Plasmodium falciparum in vitro growth by cooperation with blood monocytes in an ADCI assay correlated to the naturally acquired protection. This protein is located on the surface of the merozoite stage of P. falciparum, and is detectable in all isolates tested. Epidemiological studies demonstrated that peptides derived from the amino acid sequence of MSP-3 contain potent B and T-cell epitopes recognized by a majority of individuals living in endemic areas. Moreover human antibodies either purified on the recombinant protein, or on the synthetic peptide MSP-3b, as well as antibodies raised in mice, were all found to promote parasite killing mediated by monocytes.

Some environmental and biological factors influencing the activity of entomopathogenic Bacillus on mosquito larvae in Brazil

The influence of environmental and biological factors on the efficacy of Bacillus thuringiensis serovar israelensis and B. sphaericus as mosquito larvicides are reviewed. The importance of strain dependence, cultivating media/methods, mosquito species/specificity, formulations and their relation to mosquito feeding habits, as well as temperature, solar exposure, larval density and concomitant presence of other aquatic organisms are addressed with reference to the present status of knowledge in Brazil.

Characterization and biological activity of a brazilian isolate of Bacillus sphaericus (Neide) highly toxic to mosquito larvae

Primary powders of Bacillus sphaericus strain S2 isolated from soil samples in Brazil, and strain 2362 were produced in a 14 liter fermentor. Growth patterns and sporulation observed in three trials with strains S2 and 2362 in the fermentor were similar. Second-instar larvae of Culex quinquefasciatus, Anopheles albimanus, Anopheles quadrimaculatus, and Aedes aegypti exposed for 48 hr to strain S2 responded with LC50 values of 0.25, 5.95, 12.28 and 140.0 ppb of lyophilized primary powder, respectively. Under the same conditions, strain 2362 resulted in LC50 values of 0.39, 7.16, 16.93 and 307.0 ppb of lyophilized primary powder, respectively, in those mosquito larvae. Statistical analysis of the bioassay data did not show significant differences among LC50 values observed in B. sphaericus strains S2 and 2362, at the 0.05 level. Toxins of strains S2 and 2362 were extracted at pH 12 with NaOH. Electrophoresis of the extracts in polyacrylamide gel under denaturing conditions revealed the 51 and 42 kDa toxins in both S2 and 2362 B. sphaericus strains. The presence of the 42 kDa peptide in the extracts was confirmed by Western blot and Elisa, with anti-42 kDa IgG previously prepared from strain 2362.

Conversion of membrane-bound Fas(CD95) ligand to its soluble form is associated with downregulation of its proapoptotic activity and loss of liver toxicity.

Human Fas ligand (L) (CD95L) and tumor necrosis factor (TNF)-alpha undergo metalloproteinase-mediated proteolytic processing in their extracellular domains resulting in the release of soluble trimeric ligands (soluble [s]FasL, sTNF-alpha) which, in the case of sFasL, is thought to be implicated in diseases such as hepatitis and AIDS. Here we show that the processing of sFasL occurs between Ser126 and Leu127. The apoptotic-inducing capacity of naturally processed sFasL was reduced by >1,000-fold compared with membrane-bound FasL, and injection of high doses of recombinant sFasL in mice did not induce liver failure. However, soluble FasL retained its capacity to interact with Fas, and restoration of its cytotoxic activity was achieved both in vitro and in vivo with the addition of cross-linking antibodies. Similarly, the marginal apoptotic activity of recombinant soluble TNF-related apoptosis-inducing ligand (sTRAIL), another member of the TNF ligand family, was greatly increased upon cross-linking. These results indicate that the mere trimerization of the Fas and TRAIL receptors may not be sufficient to trigger death signals. Thus, the observation that sFasL is less cytotoxic than membrane-bound FasL may explain why in certain types of cancer, systemic tissue damage is not detected, even though the levels of circulating sFasL are high.

Markers, Cofactors and Staging Systems in the Study of HIV Disease Progression: A Review

This paper is aimed at providing a comprehensive review of markers, cofactors and staging systems used for HIV disease, focusing on some aspects that nowadays could even be considered historical, and advancing in current issues such as the prognostic value of viral load measurements, viral genotypic and phenotypic characterization, and new HIV disease treatment protocols. CD4+ cell values, combined with the new viral markers mentioned are promising as a parsimonious predictor set for defining both severity and progression. An adequate predictor of patient resource use for planning purposes still needs to be defined

Central and Cortical Gray Mater Segmentation of Magnetic Resonance Images of the Fetal Brain

Motivation. The study of human brain development in itsearly stage is today possible thanks to in vivo fetalmagnetic resonance imaging (MRI) techniques. Aquantitative analysis of fetal cortical surfacerepresents a new approach which can be used as a markerof the cerebral maturation (as gyration) and also forstudying central nervous system pathologies [1]. However,this quantitative approach is a major challenge forseveral reasons. First, movement of the fetus inside theamniotic cavity requires very fast MRI sequences tominimize motion artifacts, resulting in a poor spatialresolution and/or lower SNR. Second, due to the ongoingmyelination and cortical maturation, the appearance ofthe developing brain differs very much from thehomogenous tissue types found in adults. Third, due tolow resolution, fetal MR images considerably suffer ofpartial volume (PV) effect, sometimes in large areas.Today extensive efforts are made to deal with thereconstruction of high resolution 3D fetal volumes[2,3,4] to cope with intra-volume motion and low SNR.However, few studies exist related to the automatedsegmentation of MR fetal imaging. [5] and [6] work on thesegmentation of specific areas of the fetal brain such asposterior fossa, brainstem or germinal matrix. Firstattempt for automated brain tissue segmentation has beenpresented in [7] and in our previous work [8]. Bothmethods apply the Expectation-Maximization Markov RandomField (EM-MRF) framework but contrary to [7] we do notneed from any anatomical atlas prior. Data set &Methods. Prenatal MR imaging was performed with a 1-Tsystem (GE Medical Systems, Milwaukee) using single shotfast spin echo (ssFSE) sequences (TR 7000 ms, TE 180 ms,FOV 40 x 40 cm, slice thickness 5.4mm, in plane spatialresolution 1.09mm). Each fetus has 6 axial volumes(around 15 slices per volume), each of them acquired inabout 1 min. Each volume is shifted by 1 mm with respectto the previous one. Gestational age (GA) ranges from 29to 32 weeks. Mother is under sedation. Each volume ismanually segmented to extract fetal brain fromsurrounding maternal tissues. Then, in-homogeneityintensity correction is performed using [9] and linearintensity normalization is performed to have intensityvalues that range from 0 to 255. Note that due tointra-tissue variability of developing brain someintensity variability still remains. For each fetus, ahigh spatial resolution image of isotropic voxel size of1.09 mm is created applying [2] and using B-splines forthe scattered data interpolation [10] (see Fig. 1). Then,basal ganglia (BS) segmentation is performed on thissuper reconstructed volume. Active contour framework witha Level Set (LS) implementation is used. Our LS follows aslightly different formulation from well-known Chan-Vese[11] formulation. In our case, the LS evolves forcing themean of the inside of the curve to be the mean intensityof basal ganglia. Moreover, we add local spatial priorthrough a probabilistic map created by fitting anellipsoid onto the basal ganglia region. Some userinteraction is needed to set the mean intensity of BG(green dots in Fig. 2) and the initial fitting points forthe probabilistic prior map (blue points in Fig. 2). Oncebasal ganglia are removed from the image, brain tissuesegmentation is performed as described in [8]. Results.The case study presented here has 29 weeks of GA. Thehigh resolution reconstructed volume is presented in Fig.1. The steps of BG segmentation are shown in Fig. 2.Overlap in comparison with manual segmentation isquantified by the Dice similarity index (DSI) equal to0.829 (values above 0.7 are considered a very goodagreement). Such BG segmentation has been applied on 3other subjects ranging for 29 to 32 GA and the DSI hasbeen of 0.856, 0.794 and 0.785. Our segmentation of theinner (red and blue contours) and outer cortical surface(green contour) is presented in Fig. 3. Finally, torefine the results we include our WM segmentation in theFreesurfer software [12] and some manual corrections toobtain Fig.4. Discussion. Precise cortical surfaceextraction of fetal brain is needed for quantitativestudies of early human brain development. Our workcombines the well known statistical classificationframework with the active contour segmentation forcentral gray mater extraction. A main advantage of thepresented procedure for fetal brain surface extraction isthat we do not include any spatial prior coming fromanatomical atlases. The results presented here arepreliminary but promising. Our efforts are now in testingsuch approach on a wider range of gestational ages thatwe will include in the final version of this work andstudying as well its generalization to different scannersand different type of MRI sequences. References. [1]Guibaud, Prenatal Diagnosis 29(4) (2009). [2] Rousseau,Acad. Rad. 13(9), 2006, [3] Jiang, IEEE TMI 2007. [4]Warfield IADB, MICCAI 2009. [5] Claude, IEEE Trans. Bio.Eng. 51(4) (2004). [6] Habas, MICCAI (Pt. 1) 2008. [7]Bertelsen, ISMRM 2009 [8] Bach Cuadra, IADB, MICCAI 2009.[9] Styner, IEEE TMI 19(39 (2000). [10] Lee, IEEE Trans.Visual. And Comp. Graph. 3(3), 1997, [11] Chan, IEEETrans. Img. Proc, 10(2), 2001 [12] Freesurfer,http://surfer.nmr.mgh.harvard.edu.

Postinfarction heart failure in rats is associated with upregulation of GLUT-1 and downregulation of genes of fatty acid metabolism.

OBJECTIVES: Increasing evidence suggests that left ventricular remodeling is associated with a shift from fatty acid to glucose metabolism for energy production. The aim of this study was to determine whether left ventricular remodeling with and without late-onset heart failure after myocardial infarction is associated with regional changes in the expression of regulatory proteins of glucose or fatty acid metabolism. METHODS: Myocardial infarction was induced in rats by ligation of the left anterior descending coronary artery (LAD). In infarcted and sham-operated hearts the peri-infarction region (5-mm zone surrounding the region at risk), the interventricular septum and the right ventricular free wall were separated for analysis. RESULTS: At 8 and 20 weeks after LAD ligation, the peri-infarction region and the septum exhibited marked re-expression of atrial natriuretic factor [+252+/-37 and +1093+/-279%, respectively, in the septum (P<0.05)] and of alpha-smooth muscle actin [+34+/-10 and +43+/-14%, respectively, in the septum (P<0.05)]. At 8 weeks, when left ventricular hypertrophy was present without signs of heart failure, myocardial mRNA expression of glucose transporters (GLUT-1 and GLUT-4) was not altered, whereas mRNA expression of medium-chain acyl-CoA dehydrogenase (MCAD) was significantly reduced in the peri-infarction region (-25+/-7%; P<0.05). In hearts exhibiting heart failure 20 weeks after infarct-induction there was a change in all three ventricular regions of both mRNA and protein content of GLUT-1 [+72+/-28 and +121+/-15%, respectively, in the peri-infarction region (P<0.05)] and MCAD [-29+/-9 and -56+/-4%, respectively, in the peri-infarction region (P<0.05)]. CONCLUSION: In rats with large myocardial infarction, progression from compensated remodeling to overt heart failure is associated with upregulation of GLUT-1 and downregulation of MCAD in both the peri-infarction region and the septum.

An infrared reflection-absorption spectroscopic (IRRAS) study of the interaction of lipid A and lipopolysaccharide Re with endotoxin-binding proteins.

Lipopolysaccharides (LPS, endotoxins) are main constituents of the outer membranes of Gram-negative bacteria, with the 'endotoxic principle' lipid A anchoring LPS into the membrane. When LPS is removed from the bacteria by the action of the immune system or simply by cell dividing, it may interact strongly with immunocompetent cells such as mononuclear cells. This interaction may lead, depending on the LPS concentration, to beneficial (at low) or pathophysiological (at high concentrations) reactions, the latter frequently causing the septic shock syndrome. There is a variety of endogenous LPS-binding proteins. To this class belong lactoferrin (LF) and hemoglobin (Hb), which have been shown to suppress and enhance the LPS-induced cytokine secretion in mononuclear cells, respectively. To elucidate the interaction mechanisms of endotoxins with these proteins, we have investigated in an infrared reflection-absorption spectroscopy (IRRAS) study the interaction of LPS or lipid A monolayers at the air/water interface with LF and Hb proteins, injected into the aqueous subphase. The data are clearly indicative of completely different interaction mechanisms of the endotoxins with the proteins, with the LF acting only at the LPS backbone, whereas Hb incorporates into the lipid monolayer. These data allow an understanding of the different reactivities in the biomedicinal systems.

The Irish Infancy Narratives and their Relationship with Latin Sources

(Résumé de l'ouvrage) In 1927 M. R. James published Latin Infancy Gospels, identified by him in two related but not identical manuscripts (one the British Library Arundel 404; the other from Hereford), together with a parallel text from the Irish manuscript known as the Leabhar Breac. Later researches brought to light more manuscripts of this Latin work, and also of the Irish text. James recognized that his apocryphal Latin Infancy text was compiled from a combination of the Protevangelium of James and a hitherto unknown text which he named "The Source". Recent research has identified a full Latin translation of the Protevangelium of James. A hitherto unrecognized Irish Infancy Narrative has also been identified in the Dublin manuscript known as the Liber Flavus Fergusiorum. A deep study of this related tradition was called for. This has been carried out over the past ten years by an Irish team in conjunction with Professor Daniel Kaestli and AELAC. The fruits of this labour are published in these two volumes. Volume 13 has a general introduction with a historical sketch of New Testament apocrypha in Ireland and a history of research on the subject. This is followed by a comparison of the Infancy Narratives in the Leabhar Breac and the Liber Flavus Fergusiorum. There are special introductions to these Infancy texts, followed by critical editions of the Irish texts, accompanied by English translations and rich annotation. Next there is similar treatment of the Irish versified Narrative (from ca. 700) of the Childhood Deeds of Jesus (commonly known as the Infancy Narrative (or Gospel) of Thomas. There is then (in volume 14, but with continuous pagination) the edition and translation of an Irish thirteenth-century poem with elements from Infancy Narratives, and both Latin and Irish texts on the wonders at Christ's birth, accompanied by translations and notes. The edition of the Irish material is followed by a critical edition of the full Arundel and Hereford forms of the Infancy Narrative (here referred to as the "J Compilation"), together with a detailed study of all the questions relating to this work. The volume concludes with a critical edition (by Rita Beyers) of the Latin text of the Protevangelium of James, accompanied by a detailed study of the work.. The work contains a detailed study of the Latin translations of the Protevangelium of James and the transmission of this work in the West. The "J Compilation" (a combination of the Protevangelium and texts of Pseudo-Matthew) can be traced back in manuscript transmission to ca. 800,and must have originated some time earlier. Behind it stands an earlier "I ("I" for Irish) Compilation" without influence from Pseudo-Matthew, the form found in the Irish witnesses. It is argued that M. R. James's "Source" may be of Judaeo-Christian origin and may really be the Gospel of the Nazoreans. Among the indexes there is a list of all the Irish words found in the texts. This edition of the Irish and related Latin texts is a major contribution to the study of the apocryphal Infancy Narratives. It should also be of particular interest to Celtic scholars, to students of Irish ecclesiastical learning, and in general to all medievalists.

Bone anabolic potential of soy isoflavones and plant extracts and genomic changes during differentiation of hPOB-tert osteoblast-like cells

Summary For the nutritional management of bone health and the prevention of osteoporosis it is important to identify nutrients that positively influence the bone remodeling process at the cellular level. Soy isoflavones show promising osteoprotective effects in animals and humans but their mechanism of action in bone cells is yet poorly understood. Firstly, soy tissue cultures were characterized as a new and optimized source of isoflavones. A large variability in the isoflavone content was observed and high-producing strains (46.3 mg/g dry wt isoflavones) were identified. In the Ishikawa cells bioassay, the estrogenicity of isoflavones was confirmed to be 1000 to 10000 less than 17Mestradiol and that of the malonyl forms was shown for the first time (EC50 of 350 nM and 1880 nM for malonylgenistin and malonyldaidzin, respectively). The estrogenic activity of soya tissue culture extracts correlated to their isoflavone content. Secondly, the effects of phytonutrients on BMP-2 gene expression and on the mevalonate synthesis pathway, as key mediators of bone formation, were investigated. Dietary achievable concentrations of genistein and daidzein (10vM), and statins (4xM) but not 17M estradiol (10nM), induced BMP-2 gene expression (by up to 3-fold) and inhibited the cholesterol biosynthetic pathway (by up to 50%) in the human osteoblastic cell line hP0B¬tert. In addition, several plant extracts (Cyperus rotundus, Lindera benzoin and Cnidium monnieri) induced BMP-2 gene expression but this induction was not restricted to the inhibition of the cholesterol synthesis pathway neither to the estrogenicity. Finally, the gene expression profiles during hP0B-tert differentiation induced by vitamin D and dexamethasone were analyzed with the Affymetrix human GeneChip. 1665 different genes and 98 ESTs were significantly regulated. The expression profiles of bone-related genes was largely in agreement with previously documented patterns, supporting the physiological relevance of the genomic results and the hP0B-tert cell line as a valid model of human osteoblast differentiation. The expression of alternative differentiation markers during the osteogenic treatment of hP0B-tert cells indicated that the adipocyte and myoblast differentiation pathways were repressed, confirming that these culture conditions allowed only osteoblast differentiation. The gene ontology analysis identified further sub-groups of genes that may be involved in the bone formation process. Aims of the thesis In order to define new strategies for the nutritional management of bone health and for the prevention of osteoporosis the major goal of the present work was to investigate the potential of phytonutrients to positively modulate the bone formation process at the cellular level and, in particular: 1.To select and optimise alternative plant sources containing high levels of isoflavones with estrogenic activity (Chapter 3). 2.To compare the effects of statins and phytonutrients on BMP-2 gene expression and on the mevalonate synthesis pathway and to select new plant extracts with a bone anabolic potential (Chapter 4). 3.To further characterize the new human periosteal cell line, hP0B-tert, as a bone- formation model, by elucidating its gene expression profile during differentiation induced by vitamin D and dexamethasone (Chapter 5).

Trypanosoma cruzi: genetic group with peculiar biochemical and biological behavior

Thirty-two Trypanosoma cruzi strains, isolated from chronic chagasic patients in the northwest of the state of Paraná (Brazil), were analyzed using molecular, biochemical and biological characteristics. Genotypic analysis using randomly amplified polymorphic DNA and simple sequence repeat-anchored polymerase chain reaction amplified profiles showed a large, genetically well-correlated group that contained the majority of the strains and a divergent group that included the PR-150 strain. For glycoconjugate composition, the PR-150 strain was different from the other strains considering the absence or presence of specific bands in aqueous or detergent phases. This strain was also totally different from the others in one out of the six parameters related to in vitro and in vivo biological behavior. We highlight the fact that the PR-150 was totally resistant to benznidazole. For the other biological parameters this strain was not totally distinct from the others, but it showed a peculiar behavior.

Diagnostic accuracy of free and total metanephrines in plasma and fractionated metanephrines in urine of patients with pheochromocytoma.

BACKGROUND: Plasma free and urinary metanephrines are recognized biomarkers for the assessment of pheochromocytoma. Plasma total metanephrines with a long half-life may represent another useful biomarker. OBJECTIVE: The aim of this study is to evaluate the diagnostic performances of plasma total metanephrines alone or combined with free metanephrines and fractionated 24-h urinary metanephrines. METHODS: A retrospective, case-control diagnostic test study was conducted between 1999 and 2007 in two university hospitals in Switzerland and two institutions in France. The patients included 46 cases with histologically proven pheochromocytoma, and 181 controls suspected of tumor with negative investigations and 3-year follow-up. None had renal dysfunction. Sensitivity and specificity were compared after expressing each measurement result as a ratio over its upper reference limit, adding the ratios of normetanephrine and metanephrine, and defining cut-off values of 1 or 2 for this sum. RESULTS: Applying a cut-off value of 1, plasma free and total metanephrines and urinary fractionated metanephrines had similar sensitivities of 96% (95% confidence interval, 86-99%), 95% (85-99%), and 95% (84-99%) along with similar specificities of 89% (83-94%), 91% (84-95%), and 86% (80-91%). A cut-off of 2 for the sum of ratios over reference limit improves the specificity, and it can be used for a confirmation test based on another biomarker taken among the three biomarkers. CONCLUSION: All three metanephrine-based tests perform equivalently for diagnosing pheochromocytoma in the absence of renal insufficiency, and can be conveniently associated two by two for confirming/excluding tumor.

Appropriateness and long-term discontinuation rate of biological therapies in ulcerative colitis.

BACKGROUND: Anti-TNFα agents are commonly used for ulcerative colitis (UC) therapy in the event of non-response to conventional strategies or as colon-salvaging therapy. The objectives were to assess the appropriateness of biological therapies for UC patients and to study treatment discontinuation over time, according to appropriateness of treatment, as a measure of outcome. METHODS: We selected adult ulcerative colitis patients from the Swiss IBD cohort who had been treated with anti-TNFα agents. Appropriateness of the first-line anti-TNFα treatment was assessed using detailed criteria developed during the European Panel on the Appropriateness of Therapy for UC. Treatment discontinuation as an outcome was assessed for categories of appropriateness. RESULTS: Appropriateness of the first-line biological treatment was determined in 186 UC patients. For 64% of them, this treatment was considered appropriate. During follow-up, 37% of all patients discontinued biological treatment, 17% specifically because of failure. Time-to-failure of treatment was significantly different among patients on an appropriate biological treatment compared to those for whom the treatment was considered not appropriate (p=0.0007). Discontinuation rate after 2years was 26% compared to 54% between those two groups. Patients on inappropriate biological treatment were more likely to have severe disease, concomitant steroids and/or immunomodulators. They were also consistently more likely to suffer a failure of efficacy and to stop therapy during follow-up. CONCLUSION: Appropriateness of first-line anti-TNFα therapy results in a greater likelihood of continuing with the therapy. In situations where biological treatment is uncertain or inappropriate, physicians should consider other options instead of prescribing anti-TNFα agents.