Meta-analysis indicates lack of local adaptation of Schistosoma mansoni to Biomphalaria alexandrina in Egypt

In Egypt, reclaiming portions of the desert using water from the Nile has resulted in large-scale invasion of Biomphalaria alexandrina in these regions. Studies exploring the local adaptation of Schistosoma mansoni to its snail host have been carried out to predict the extension of schistosomiasis to newly reclaimed areas. A meta-analysis of the relevant reports was conducted to compare the different biological characteristics of sympatric and allopatric Schistosoma mansoni and Biomphalaria alexandrina using different experimental designs. The results showed that there were no significant differences in the biological characteristics of sympatric and allopatric populations. The experimental design of some of the studies analyzed was found to affect the total cercarial production. The distance between the origin of the parasite and that of the snail did not affect any of the biological characteristics. The results showed that there is no evidence of local adaptation between Schistosoma mansoni and Biomphalaria alexandrina; however, the parasite is adapted to its intermediate host throughout the water bodies located in Egypt. The absence of local adaptation between Schistosoma mansoni and Biomphalaria alexandrina is likely of critical importance in predicting public health risks engendered by future reclaimed agriculture projects. Indeed, these results could assist in determining the appropriate balance between the development of water resource projects and schistosomiasis control in Egypt.     

Decellularization and genipin crosslinking of amniotic membrane suitable for tissue engineering applications

Abstract

Amniotic membrane has the potential to be used as scaffold in various tissue engineering applications. However, increasing its biostability at the same time maintaining its biocompatibility is important to enhance its usage as a scaffold. This studied characteristics genipin-crosslinked amniotic membrane as a bioscaffold. Redundant human amniotic membranes (HAM) divided into native (nAM), decellularized (dAM) and genipin-crosslinked (clAM) groups. The dAM and clAM group were decellularized using thermolysin (TL) and sodium hydroxide (NaOH) solution. Next, clAM group was crosslinked with 0.5% and 1.0% (w/v) genipin. The HAM was then studied for in vitro degradation, percentage of swelling, optical clarity, ultrastructure and mechanical strength. Meanwhile, fibroblasts isolated from nasal turbinates were then seeded onto nAM, dAM and clAM for biocompatibility studies. clAM had the slowest degradation rate and were still morphologically intact after 30 days of incubation in 0.01% collagenase type 1 solution. The dAM had a significantly highest percentage of swelling than other groups (p?<?0.05). Besides, the dAM retained the collagen content at similar level of nAM. Although the dAM had highest mechanical strength compared to the rest of the groups, the differences were statistically insignificant. Cell attachment on dAM and 0.5% clAM was higher compared to that on nAM and 1.0% clAM. In conclusion, clAM have better biostability and biocompatibility compared to the nAM and dAM. Together with other suitable characteristics of the clAM such as percentage of swelling, structural integrity and ECM content, clAM is suitable as scaffold for various tissue engineering applications.     

Inhibition of Mycobacterial Growth In Vitro following Primary but Not Secondary Vaccination with Mycobacterium bovis BCG

Despite the widespread use of the Mycobacterium bovis BCG vaccine, there are more than 9 million new cases of tuberculosis (TB) every year, and there is an urgent need for better TB vaccines. TB vaccine candidates are selected for evaluation based in part on the detection of an antigen-specific gamma interferon (IFN-γ) response. The measurement of mycobacterial growth in blood specimens obtained from subjects immunized with investigational TB vaccines may be a better in vitro correlate of in vivo vaccine efficacy. We performed a clinical study with 30 United Kingdom adults who were followed for 6 months to evaluate the abilities of both a whole-blood- and a novel peripheral blood mononuclear cell (PBMC)-based mycobacterial growth inhibition assay to measure a response to primary vaccination and revaccination with BCG. Using cryopreserved PBMCs, we observed a significant improvement in mycobacterial growth inhibition following primary vaccination but no improvement in growth inhibition following revaccination with BCG (P < 0.05). Mycobacterial growth inhibition following primary BCG vaccination was not correlated with purified protein derivative (PPD) antigen-specific IFN-γ enzyme-linked immunospot (ELISPOT) responses. We demonstrate that a mycobacterial growth inhibition assay can detect improved capacity to control growth following primary immunization, but not revaccination, with BCG. This is the first study to demonstrate that an in vitro growth inhibition assay can identify a difference in vaccine responses by comparing both primary and secondary BCG vaccinations, suggesting that in vitro growth inhibition assays may serve as better surrogates of clinical efficacy than the assays currently used for the assessment of candidate TB vaccines.     

Expression of myosin VIIA during mouse embryogenesis

 The gene encoding myosin VIIA is responsible for the mouse shaker-1 phenotype, which consists of deafness and balance deficiency related to cochlear and vestibular neuroepithelial defects. In humans, a defective myosin VIIA gene is responsible for Usher syndrome type IB, which associates congenital deafness, vestibular dysfunction and retinitis pigmentosa. In an attempt to progress in the understanding of the function(s) of myosin VIIA, we studied the expression of the myosin VIIA gene during mouse embryonic development. Embryos from day 9 (E9) to E18 were analyzed by in situ hybridization and immunohistofluorescence. The myosin VIIA mRNA and protein were consistently detected in the same embryonic tissues throughout development. Myosin VIIA was first observed in the otic vesicle at E9, and later in a variety of tissues. The olfactory epithelium and the liver express it as early as E10. In the retinal pigment epithelium, choroid plexus, adrenal gland and tongue, expression begins at E12 and in the testis and the adenohypophysis at E13. In the small intestine, kidney and hair follicles of the vibrissae, expression of myosin VIIA starts only at E15. Myosin VIIA expression was observed only in epithelial cell types, most of which possess microvilli or cilia. Interestingly, myosin VIIA expression seems to be concomitant with the appearance of these structures in the epithelial cells, suggesting a role for this myosin in their morphogenesis. The cellular location of myosin VIIA within sensory hair cells and olfactory receptor neurons also argues for a role of this protein in the synaptic vesicle trafficking. Accepted: 21 March 1997     

Genome-scale reconstruction of the Saccharomyces cerevisiae metabolic network

The metabolic network in the yeast Saccharomyces cerevisiae was reconstructed using currently available genomic, biochemical, and physiological information. The metabolic reactions were compartmentalized between the cytosol and the mitochondria, and transport steps between the compartments and the environment were included. A total of 708 structural open reading frames (ORFs) were accounted for in the reconstructed network, corresponding to 1035 metabolic reactions. Further, 140 reactions were included on the basis of biochemical evidence resulting in a genome-scale reconstructed metabolic network containing 1175 metabolic reactions and 584 metabolites. The number of gene functions included in the reconstructed network corresponds to approximately 16% of all characterized ORFs in S. cerevisiae. Using the reconstructed network, the metabolic capabilities of S. cerevisiae were calculated and compared with Escherichia coli. The reconstructed metabolic network is the first comprehensive network for a eukaryotic organism, and it may be used as the basis for in silico analysis of phenotypic functions.     

Pathogenic potential of Blastocystis hominis in laboratory mice

Blastocystis hominis is a ubiquitous enteric protozoan whose pathogenic potential is still controversial. This study was carried out to clarify the pathogenecity of B. hominis infection and to study the proper number of parasites for mice infection. A total of 15 albino mice were orally inoculated with B. hominis and divided according to the inoculums, 10², 10⁵, and 4 × 10⁷ B. hominis forms/100 μl saline, into three groups consisting of five mice each, GI, GII GIII, respectively. In addition with group IV (uninfected control) consisting of five mice. All mice were sacrificed 2 weeks post-infection. The results revealed that all mice of GIII and two mice of GII got the infection while all mice of GI showed a completely negative result. Histopathological examination of large intestine on highly infected group (GIII) showed that B. hominis infiltrated the lamina propria, the submucosa, and the muscle layers in the form of collection of vacuolar forms. This was accompanied by active colitis with infiltration of mixed inflammatory cells. In conclusion, this study revealed that large number of B. hominis is essential for oral infection of mice and that vacuolar forms of B. hominis can invade the lamina propria, the submucosa, and even the muscle layers.     

Contrasting effects of errorless naming treatment and gestural facilitation for word retrieval in aphasia

We compared the effects of two treatments for aphasic word retrieval impairments, errorless naming treatment (ENT) and gestural facilitation of naming (GES), within the same individuals, anticipating that the use of gesture would enhance the effect of treatment over errorless treatment alone. In addition to picture naming, we evaluated results for other outcome measures that were largely untested in earlier ENT studies. In a single participant crossover treatment design, we examined the effects of ENT and GES in eight individuals with stroke-induced aphasia and word retrieval impairments (three semantic anomia, five phonological anomia) in counterbalanced phases across participants. We evaluated effects of the two treatments for a daily picture naming/gesture production probe measure and in standardised aphasia tests and communication rating scales administered across phases of the experiment. Both treatments led to improvements in naming of trained words (small-to-large effect sizes) in individuals with semantic and phonological anomia. Small generalised naming improvements were noted for three individuals with phonological anomia. GES improved use of corresponding gestures for trained words (large effect sizes). Results were largely maintained at one month post-treatment completion. Increases in scores on standardised aphasia testing also occurred for both ENT and GES training. Both ENT and GES led to improvements in naming measures, with no clear difference between treatments. Increased use of gestures following GES provided a potential compensatory means of communication for those who did not improve verbal skills. Both treatments are considered to be effective methods to promote recovery of word retrieval and verbal production skills in individuals with aphasia.     

Reconstruction of the orientation distribution function in single‐ and multiple‐shell q‐ball imaging within constant solid angle

q‐Ball imaging is a high‐angular‐resolution diffusion imaging technique that has been proven very successful in resolving multiple intravoxel fiber orientations in MR images. The standard computation of the orientation distribution function (the probability of diffusion in a given direction) from q‐ball data uses linear radial projection, neglecting the change in the volume element along each direction. This results in spherical distributions that are different from the true orientation distribution functions. For instance, they are neither normalized nor as sharp as expected and generally require postprocessing, such as artificial sharpening. In this paper, a new technique is proposed that, by considering the solid angle factor, uses the mathematically correct definition of the orientation distribution function and results in a dimensionless and normalized orientation distribution function expression. Our model is flexible enough so that orientation distribution functions can be estimated either from single q‐shell datasets or by exploiting the greater information available from multiple q‐shell acquisitions. We show that the latter can be achieved by using a more accurate multiexponential model for the diffusion signal. The improved performance of the proposed method is demonstrated on artificial examples and high‐angular‐resolution diffusion imaging data acquired on a 7‐T magnet. Magn Reson Med, 2010. © 2010 Wiley‐Liss, Inc.     

Reasons for risk-reducing mastectomy versus MRI-screening in a cohort of women at high hereditary risk of breast cancer

Objective

To determine the reasons that motivate women in a cohort of women under intensive surveillance for breast cancer to undergo risk-reducing mastectomy (RRM).

Patients and methods

Women with a BRCA1 or BRCA2 mutation who were enrolled in an MRI-based breast screening study were eligible to participate in this survey. A self-administered questionnaire was given to women who did, and who did not terminate annual MRI-based surveillance in order to undergo RRM. The questionnaire included information on family history, risk perception and satisfaction with screening. In addition, women were asked to provide the principal reason for their choice of having preventive surgery or not, and were asked about their satisfaction with this choice.

Results

246 women without breast cancer participated in the study. Of these, 39 women (16%) elected to have RRM at some point after initiating screening. Although women who had a mother or sister with breast cancer were more likely to opt for RRM than were women with no affected first-degree relative (21% versus 10%) this did not reach statistical significance. Women who perceived their breast cancer risk to be greater than 50% were more likely to opt for RRM than were women who estimated their risk to be less than 50% (19% versus 6%). Fear of cancer was the most common reason cited for choosing to have RRM (38% of respondents) followed by having had a previous cancer, (25%), then concern over their children (16%).

Conclusion

Among women with a BRCA mutation who are enrolled in an MRI-based screening program, a high perception of personal breast cancer risk and a history of breast cancer in a first-degree relative are predictors of the decision to have RRM.