[Evaluation of the success of medical abortion by a plasma hCG control threshold]. / Évaluation du succès de l'interruption volontaire de grossesse médicamenteuse par un seuil d'hCG sérique.

OBJECTIVES: In France, monitoring of the success of medical abortion is recommended 2 to 3 weeks after the procedure. However, there is no clear consensus on the modalities of this monitoring. The main objective of this study is to identify a threshold of serum hCG (human chorionic gonadotropin) control for medical abortions ≤7 weeks of gestation below which success can be confirmed without recourse to pelvic ultrasound. METHODS: This is a retrospective multicenter study conducted over a 14-month period. The serum hCG level, measured between the 15th and 25th day following the abortion, was compared with the results of the pelvic ultrasound performed at the follow-up visit. Ultrasound failure was defined as retention or persistent pregnancy. RESULTS: Among the 624 women included, the failure rate was 22.3%, including 86.3% of retentions, 8.6% of pregnancies stopped and 5% of pregnancies progressed. Using a ROC curve, the threshold value of hCG found to exclude failure at 95% was 253 IU/l (AUC=0.9202, sensitivity=84.17%, specificity=85.95% and positive predictive value [PPV]=63%). CONCLUSIONS: A serum hCG level ≤253 IU/l is sufficient to affirm the efficacy of medical abortion. However, since PPV is only 63% for this threshold, ultrasound should be reserved for women with high hCG levels.

Trade-offs direct the evolution of coloration in Galápagos land snails.

Increasingly, multiple selective factors are recognized as jointly contributing to the evolution of morphology. What is not clear is how these forces vary across communities to promote morphological diversification among related species. In this study of Galápagos endemic snails (genus Naesiotus), we test several hypotheses of colour evolution. We observe mockingbirds (genus Mimus) predating live snails and find that avian predation selects against conspicuous shells. The evolutionary outcome of this selection is a diversity of shell colours across snails of the archipelago, each closely matching local backgrounds. We also find that snails more regularly exposed to the hot, equatorial sun reflect more light than shells of species from shadier habitats, suggesting a role for thermoregulatory constraints directing colour evolution. The signature of thermoregulatory selection is most clear in comparatively young communities (on the youngest islands), while the signature of selection from predators is most evident in older communities (on the older islands). Together, our findings point to a scenario of shifting selective forces along island ontogeny and community maturity that lead to the distribution of snail coloration we observe in Galápagos. Complex selective regimes such as these may have more responsibility for morphological diversity than is currently recognized.

Human kallikrein-related peptidase 12 stimulates endothelial cell migration by remodeling the fibronectin matrix.

Kallikrein-related peptidase 12 (KLK12) is a kallikrein family peptidase involved in angiogenesis - a complex biological process in which the sprouting, migration and stabilization of endothelial cells requires extracellular matrix remodeling. To characterize the molecular mechanisms associated with KLK12's proangiogenic activity, we evaluated its ability to hydrolyze various matrix proteins. Our results show that KLK12 efficiently cleaved the human extracellular matrix proteins fibronectin and tenascin, both of which are involved in the regulation of endothelial cell adhesion and migration. For fibronectin, the major proteolytic product generated by KLK12 was a 29 kDa fragment containing the amino-terminal domain and the first five type I fibronectin-domains, which are essential for regulating fibronectin assembly. We also demonstrated that KLK12-mediated fibronectin proteolysis antagonizes fibronectin polymerization and fibronectin fibril formation by endothelial cells, leading to an increase in cell migration. Furthermore, a polyclonal antibody raised against KLK12's proteolytic cleavage site on fibronectin prevented the KLK12-dependent inhibition of fibronectin polymerization and the KLK12-mediated pro-migratory effect on endothelial cells. Taken as a whole, our results indicate that KLK12's proangiogenic effect is mediated through several molecular mechanisms.

Management of breech and twin labor during registrarship: A two-year prospective, observational study.

INTRODUCTION: Breech presentation and twin pregnancy are regarded as stressful situations for medical staff. This stress is often associated with an increased likelihood of intervention during labor - especially when the on-shift obstetrician lacks experience. MATERIAL AND METHODS: We performed a 2-year prospective, observational study of cesarean section (CSDs) and assisted vaginal (AVDs) deliveries in a tertiary maternity unit for attempted vaginal deliveries of breech presentations and twin pregnancies. The obstetric management decisions taken by a group of four registrars were compared with those taken by a group of 11 experienced obstetricians. Changes over time in practice were also monitored. RESULTS: Registrars managed 66 and 52 breech presentations and twin pregnancies respectively (30 and 27 in the experienced group). Groups' neonatal outcomes were similar. There were no intergroup differences in proportions of CSDs for either breech presentations (25 [37.5%] vs. 15 [50%] in the registrar and experienced groups, respectively; P=0.26) or twin pregnancies (11 [21.1%] vs. 6 [22.2%], respectively; P=0.91) or in proportion of AVDs for twin pregnancies (41 [78.8%] vs. 21 [77.8%], respectively; P=0.91). Proportions of CSDs for breech presentation and AVDs for twin pregnancies did not change over time in either group. However, proportion of CSDs for twin pregnancies increased over time in the registrar group (P=0.004). DISCUSSION: Well-trained registrars appeared to have acquired the skills required to safely manage an obstetric ward; this pleads to maintain clinical practice during residency to preserve low CSD and AVD rates.

[Infertility: A key time to follow a medical nutritional management. Our experience on 78 patients]. / Infertilité : moment clé pour entreprendre une prise en charge nutritionnelle médicale. Expérience lilloise sur 78 patientes.

OBJECTIVES: The prevalence of female obesity is increasing. Obesity leads to increased infertility and difficulties in the management of Assisted Reproductive Technology (ART). A specialized nutritional consultation was created in 2008 at University Hospital of Lille, to support infertile obese and overweight patients and to achieve a BMI below 35kg/m(2) before pregnancy. The aim of this retrospective study was to evaluate our practice of nutritional support on weight and pregnancy rate. METHODS: Seventy-eight obese or overweight patients, followed in nutrition and ART for at least two years, were compared to a control group of 119 normal weight patients. The nutritional strategy was mainly based on lifestyle changes, to establish healthier food and higher physical activity. RESULTS: The mean initial BMI was 37.5kg/m(2) vs 35.6kg/m(2) after nutritional support (significant weight loss, [P<0.001]). Obese or overweight patients had more frequently metabolic syndrome (P<0.01). The chances of pregnancy, after weight loss, were similar to the control group both in IUI and IVF/ICSI. However, gonadotropin doses were increased in the obese and overweight group (P=0.007). The hypocaloric diet was the most effective nutritional strategy to achieve a weight loss greater than 5% of initial weight (P=0.017). Regular physical activity practice allowed also more frequently to achieve this goal (P=0.074). Even after weight loss, a significant number of gestational diabetes (25% of pregnancies in our population) occurred in the obese or overweight group. CONCLUSION: This nutritional consultation promotes weight loss in infertile obese or overweight patients. The maternity desire is a strong motivational lever to weight loss, which leads to satisfying pregnancy rate.

Collective cell migration over long time scales reveals distinct phenotypes.

INTRODUCTION: Migratory phenotypes of metastasizing tumor cells include single and collective cell migration. While migration of tumor cells is generally less cooperative than that of normal epithelial cells, our understanding of precisely how they differ in long time behavior is incomplete. OBJECTIVES: We measure in a model system how cancer progression affects collective migration on long time scales, and determine how perturbation of cell-cell adhesions, specifically reduced E-cadherin expression, affects the collective migration phenotype. METHODS: Time lapse imaging of cellular sheets and particle image velocimetry (PIV) are used to quantitatively study the dynamics of cell motion over ten hours. Long time dynamics are measured via finite time Lyapunov exponents (FTLE) and changes in FTLE with time. RESULTS: We find that non-malignant MCF10A cells are distinguished from malignant MCF10CA1a cells by both their short time (minutes) and long time (hours) dynamics. In addition, short time dynamics distinguish non-malignant E-cadherin knockdown cells from the control, but long time dynamics and increasing spatial correlations remain unchanged. DISCUSSION: Epithelial sheet collective behavior includes long time dynamics that cannot be captured by metrics that assess cooperativity based on short time dynamics, such as instantaneous speed or directionality. The use of metrics incorporating migration data over hours instead of minutes allows us to more precisely describe how E-cadherin, a clinically relevant adhesion molecule, affects collective migration. We predict that the long time scale metrics described here will be more robust and predictive of malignant behavior than analysis of instantaneous velocity fields alone.

Evaluation of Forecasting Models for Fusarium Head Blight of Wheat Under Growing Conditions of Quebec, Canada.

Fusarium head blight (FHB) is a fungal disease of wheat (Triticum aestivum L.) causing frequent economic losses to farmers under growing conditions of Eastern Canada. To assess risks associated with this disease and guide fungicide use decisions, many researchers from numerous countries have developed weather-based forecasting models. This work aims at evaluating which model produces the most accurate predictions of disease infection or deoxynivalenol (DON) content under climatic conditions occurring in Quebec. Spring wheat was grown during two seasons and winter wheat during one season at four experimental sites located in Quebec. Nine selected models for evaluation produced predictions of DON content (Canada and Italy), disease incidence (Argentina and Italy), and probability of epidemics (United States). Data from plots without fungicide (52 samples) were used to test the models listed above. Reliability of the selected forecasting models was evaluated with receiver operating characteristic (ROC) curve analysis. DON content (≥1 ppm) was the best crop damage indicator to differentiate epidemic (cases) and nonepidemic (controls) situations. Two American and the Argentinean forecasting models were more reliable than the others when the thresholds recommended in the literature were adjusted using the results for the ROC curve analyses. Those models are a good starting point for the implementation of an FHB forecasting system adapted to wheat production in Quebec.

Signal relay during chemotaxis.

The ability of cells to migrate in response to external cues, a process known as chemotaxis, is a fundamental phenomenon in biology. It is exhibited by a wide variety of cell types in the context of embryogenesis, angiogenesis, inflammation, wound healing and many other complex physiological processes. Here, we discuss the signals that control the directed migration of the social amoebae Dictyostelium discoideum both as single cells and in the context of group migration. This multi-cellular organism has served as an excellent model system to decipher amoeboid-like leukocyte migration and has played a key role in establishing signalling paradigms in the chemotaxis field. We envision that Dictyostelium will continue to bring forward basic knowledge as we seek to understand the mechanisms regulating group cell migration.

Characterization of eight microsatellite loci in the Galápagos endemic land snail Bulimulus reibischi, and their cross-species amplification.

Variation in and amplification conditions for eight polymorphic microsatellite loci initially identified from Bulimulus akamatus, a pulmonate land snail from Galápagos, are described. Intraspecific polymorphism and heterozygosity of the eight markers were studied in 19 populations of Bulimulus reibischi, a closely related species of B. akamatus. Furthermore, the eight loci were also cross-amplified in six other closely related bulimulid species. The number of alleles across populations of B. reibischi at six loci is moderate (three to 10), but considerable for two other loci (19 and 20). There is no strong evidence for linkage among any of the loci examined.

Acute G-CSF therapy is not protective during lethal E. coli sepsis.

We investigated whether decreases in circulating polymorphonuclear neutrophils (PMN) during lethal Escherichia coli (E. coli) sepsis in canines are related to insufficient host granulocyte colony-stimulating factor (G-CSF). Two-year-old purpose-bred beagles had intraperitoneal E. coli-infected or -noninfected fibrin clots surgically placed. By 10 to 12 h following clot, both infected survivors and nonsurvivors had marked increases (P = 0.001) in serum G-CSF levels (mean peak G-CSF ng/ml +/- SE, 1,931 +/- 364 and 2,779 +/- 681, respectively) compared with noninfected controls (134 +/- 79), which decreased at 24 to 48 h. Despite increases in G-CSF, infected clot placement caused delayed (P = 0.06) increases in PMN (mean +/- SE change from baseline in cells x 10(3)/mm(3) at 24 and 48 h) in survivors (+3.9 +/- 3.9 and +13.8 +/- 3.6) compared with noninfected controls (+13.1 +/- 2.8 and +9.1 +/- 2.5). Furthermore, infected nonsurvivors had decreases in PMN (-1.4 +/- 1.0 and -1.1 +/- 2.3, P = 0.006 compared with the other groups). We next investigated whether administration of G-CSF immediately after clot placement and continued for 96 h to produce more rapid and prolonged high levels of G-CSF after infection would alter PMN levels. Although G-CSF caused large increases in PMN compared with control protein from 2 to 48 h following clot in noninfected controls, it caused much smaller increases in infected survivors and decreases in infected nonsurvivors (P = 0.03 for the ordered effect of G-CSF comparing the three groups). Thus insufficient host G-CSF is unlikely the cause of decreased circulating PMN in this canine model of sepsis. Other factors associated with sepsis either alone or in combination with G-CSF itself may reduce increases or cause decreases in circulating PMN.

The relation between well-being, impostor feelings, and gender role orientation among Canadian university students.

A theoretical model of well-being identifies 6 key components that have been examined primarily in older adults (e.g., C. D. Ryff, 1989c, 1991): self-acceptance, positive relations with others, autonomy, environmental mastery, purpose in life, and personal growth (C. D. Ryff, 1995; C. D. Ryff & C. L. M. Keyes, 1995; C. D. Ryff & B. Singer, 1996). The authors examined them in a sample of 379 Canadian university students to determine how well-being was correlated with endorsement of stereotypic gender roles and with the impostor phenomenon. The participants completed Ryff's Scales of Psychological Well-Being (Ryff, personal communication, March 1996), the Clance Impostor Phenomenon Scale (P. R. Clance & M. A. O'Toole, 1988), and the Extended Personal Attributes Questionnaire (J. T. Spence, R. L. Helmreich, & C. K. Holahan, 1979). The results supported the hypotheses that (a) people with higher scores for expressive traits score higher for well-being stemming from positive relations with others, (b) people with higher scores for instrumental traits score higher for well-being related to feelings of autonomy, (c) people with higher scores for impostor feelings (and lower scores for ability confidence) score lower for self-acceptance and (d) for environmental mastery.

Dictyostelium cell dynamics.

This unit describes culturing and imaging of D. discoideum amoebae to study fundamental cellular responses, such as motility and directed migration. The system displays powerful molecular genetics that can be used to link structural determinants of proteins with in vivo cellular functions.

A temperature-sensitive adenylyl cyclase mutant of Dictyostelium.

Dictyostelium development starts with the chemotactic aggregation of up to 10(6) amoebae in response to propagating cAMP waves. cAMP is produced by the aggregation stage adenylyl cyclase (ACA) and cells lacking ACA (aca null) cannot aggregate. Temperature-sensitive mutants of ACA were selected from a population of aca null cells transformed with a library of ACA genes, a major segment of which had been amplified by error-prone PCR. One mutant (tsaca2) that can complement the aggregation null phenotype of aca null cells at 22 degrees C but not at 28 degrees C was characterized in detail. The basal catalytic activity of the enzyme in this mutant was rapidly and reversibly inactivated at 28 degrees C. Using this mutant strain we show that cell movement in aggregates and mounds is organized by propagating waves of cAMP. Synergy experiments between wild-type and tsaca2 cells, shifted to the restrictive temperature at various stages of development, showed that ACA plays an important role in the control of cell sorting and tip formation.

Localization of the G protein betagamma complex in living cells during chemotaxis.

Gradients of chemoattractants elicit signaling events at the leading edge of a cell even though chemoattractant receptors are uniformly distributed on the cell surface. In highly polarized Dictyostelium discoideum amoebas, membrane-associated betagamma subunits of heterotrimeric guanine nucleotide-binding proteins (G proteins) were localized in a shallow anterior-posterior gradient. A uniformly applied chemoattractant generated binding sites for pleckstrin homology (PH) domains on the inner surface of the membrane in a pattern similar to that of the Gbetagamma subunits. Loss of cell polarity resulted in uniform distribution of both the Gbetagamma subunits and the sensitivity of PH domain recruitment. These observations indicate that Gbetagamma subunits are not sufficiently localized to restrict signaling events to the leading edge but that their distribution may determine the relative chemotactic sensitivity of polarized cells.

Behavioral and life history responses of eastern massasauga rattlesnakes (Sistrurus catenatus catenatus) to human disturbance.

Parks and nature reserves protect important natural habitats but also provide public opportunities for outdoor recreational activities that may have unintended negative effects on wildlife. We examined the response of eastern massasauga rattlesnakes (Sistrurus catenatus catenatus) to inadvertent disturbance by humans in Killbear Provincial Park, Ontario, Canada. Radio telemetry of 25 adult snakes over two active seasons revealed that, as disturbance increased, gravid females were less visible to observers, but the visibility of non-gravid females and males did not change. Mean distance moved per day decreased and mean time between moves greater than 10 m increased in gravid females, non-gravid females and males with increasing exposure to human disturbance. However, mark-recapture data revealed no differences in the condition or growth rates of snakes, or in the litter size of gravid females, between individuals captured in disturbed and undisturbed study areas. While it is possible that the behavioral responses we observed are not sufficient to have life history consequences, more detailed information on the exposure of individual snakes to human activity is necessary before the conclusion that disturbance is not detrimental to snakes can be accepted. Similarly, other potential negative effects of human disturbance not investigated here remain to be explored.

Assessing the role of the ASP56/CAP homologue of Dictyostelium discoideum and the requirements for subcellular localization.

The CAP (cyclase-associated protein) homologue of Dictyostelium discoideum is a phosphatidylinositol 4,5-bisphosphate (PIP(2)) regulated G-actin sequestering protein which is present in the cytosol and shows enrichment at plasma membrane regions. It is composed of two domains separated by a proline rich stretch. The sequestering activity has been localized to the C-terminal domain of the protein, whereas the presence of the N-terminal domain seems to be required for PIP(2)-regulation of the sequestering activity. Here we have constructed GFP-fusions of N- and C-domain and found that the N-terminal domain showed CAP-specific enrichment at the anterior and posterior ends of cells like endogenous CAP irrespective of the presence of the proline rich region. Mutant cells expressing strongly reduced levels of CAP were generated by homologous recombination. They had an altered cell morphology with very heterogeneous cell sizes and exhibited a cytokinesis defect. Growth on bacteria was normal both in suspension and on agar plates as was phagocytosis of yeast and bacteria. In suspension in axenic medium mutant cells grew more slowly and did not reach saturation densities observed for wild-type cells. This was paralleled by a reduction in fluid phase endocytosis. Development was delayed by several hours under all conditions assayed, furthermore, motile behaviour was affected.

A novel Ras-interacting protein required for chemotaxis and cyclic adenosine monophosphate signal relay in Dictyostelium.

We have identified a novel Ras-interacting protein from Dictyostelium, RIP3, whose function is required for both chemotaxis and the synthesis and relay of the cyclic AMP (cAMP) chemoattractant signal. rip3 null cells are unable to aggregate and lack receptor activation of adenylyl cyclase but are able, in response to cAMP, to induce aggregation-stage, postaggregative, and cell-type-specific gene expression in suspension culture. In addition, rip3 null cells are unable to properly polarize in a cAMP gradient and chemotaxis is highly impaired. We demonstrate that cAMP stimulation of guanylyl cyclase, which is required for chemotaxis, is reduced approximately 60% in rip3 null cells. This reduced activation of guanylyl cyclase may account, in part, for the defect in chemotaxis. When cells are pulsed with cAMP for 5 h to mimic the endogenous cAMP oscillations that occur in wild-type strains, the cells will form aggregates, most of which, however, arrest at the mound stage. Unlike the response seen in wild-type strains, the rip3 null cell aggregates that form under these experimental conditions are very small, which is probably due to the rip3 null cell chemotaxis defect. Many of the phenotypes of the rip3 null cell, including the inability to activate adenylyl cyclase in response to cAMP and defects in chemotaxis, are very similar to those of strains carrying a disruption of the gene encoding the putative Ras exchange factor AleA. We demonstrate that aleA null cells also exhibit a defect in cAMP-mediated activation of guanylyl cyclase similar to that of rip3 null cells. A double-knockout mutant (rip3/aleA null cells) exhibits a further reduction in receptor activation of guanylyl cyclase, and these cells display almost no cell polarization or movement in cAMP gradients. As RIP3 preferentially interacts with an activated form of the Dictyostelium Ras protein RasG, which itself is important for cell movement, we propose that RIP3 and AleA are components of a Ras-regulated pathway involved in integrating chemotaxis and signal relay pathways that are essential for aggregation.

ICAM-1 and CD11b inhibition worsen outcome in rats with E. coli pneumonia.

We investigated whether inhibiting an endothelial adhesion molecule [intracellular adhesion molecule 1 (ICAM-1)] would alter outcome and lung injury in a similar fashion to inhibition of a leukocyte adhesion molecule (integrin CD11b) in a rat model of gram-negative pneumonia. Inhibition of ICAM-1 with monoclonal antibody (MAb) 1A29 (1 mg/kg sc or 0.2 or 2 mg/kg iv, q 12 h x 3) or of CD11b with MAb 1B6 (1 mg/kg sc, q 12 h x 3) were compared against similarly administered placebo proteins in rats challenged with intrabronchial Escherichia coli. After challenge, all animals were treated with antibiotics. ICAM-1 MAb (6 mg/kg, iv, total dose) increased mortality vs. control (P = 0.03). CD11b MAb (3 mg/kg, sc, total dose) did not significantly (P = 0.16) increase mortality rates, but this was not in a range of probability to exclude a harmful effect. All other doses of MAb had no significant effect on survival rates. ICAM-1 and CD11b MAbs had significantly different effects on the time course of lung injury, circulating white cells and lymphocytes, and lung lavage white cells and neutrophils (P = 0.04-0.003). CD11b MAb decreased, whereas ICAM-1 MAb increased these measures compared with control from 6 to 12 h after E. coli. However, from 144 to 168 h after E. coli both MAbs increased these measures compared with control rats but to a greater level with CD11b MAb. Thus both ICAM-1 and CD11b appear to be necessary for survival during E. coli pneumonia. Although these adhesion molecules may participate differently in early lung injury, with CD11b increasing and ICAM-1 decreasing inflammation and injury, both are important for the resolution of later injury. During gram-negative pneumonia the protective roles of ICAM-1 and CD11b may make their therapeutic inhibition difficult.