New developments providing mechanistic insight into the impact of the microbiota on allergic disease

The increase in allergic diseases over the past several decades is correlated with changes in the composition and diversity of the intestinal microbiota. Microbial-derived signals are critical for instructing the developing immune system and conversely, immune regulation can impact the microbiota. Perturbations in the microbiota composition may be especially important during early-life when the immune system is still developing, resulting in a critical window of opportunity for instructing the immune system. This review highlights recent studies investigating the role of the microbiome in susceptibility or development of allergic diseases with a focus on animal models that provide insight into the mechanisms and pathways involved. Identification of a causal link between reduced microbial diversity or altered microbial composition and increased susceptibility to immune-mediated diseases will hopefully pave the way for better preventive therapies.

AN INVESTIGATION INTO THE EFFECT OF TESTOSTERONE ON THE QUANTITATIVE MAINTENANCE OF SPERMATOGENESIS IN THE HYPOPHYSECTOMIZED ADULT RAT (PHARMACOKINETICS, MORPHOMETRY, STATISTICS)

Administration of gonadotropins or testosterone (T) will maintain qualitatively normal spermatogenesis and fertility in hypophysectomized (APX) rats. However, quantitative maintenance of the spermatogenic process in APX rats treated with T alone or in combination with follicle stimulating hormone (FSH) has not been demonstrated. Studies reported here were conducted to determine whether it would be possible to increase intratesticular testosterone (ITT) levels in APX rats to those found in normal animals by administration of appropriate amounts of testosterone propionate (TP) and if under these conditions spermatogenesis can be maintained quantitatively. Quantitative analysis of spermatogenesis was performed on stages VI and VII of the spermatogenic cycle utilizing criteria of Leblond and Clermont (1952) all cell types were enumerated. In a series of experiments designed to investigate the effects of T on spermatogenesis, TP was administered to 60 day old APX rats twice daily for 30 days in doses ranging from 0.6 to 15 mg/day or from 0.6 to 6.0 mg/day in combination with FSH. The results of this study demonstrate that the efficiency of transformation of type A to type B spermatogonia and the efficacy of the meiotic prophase are related to ITT levels, and that quantitatively normal completion of the reduction division requires normal ITT levels. The ratio of spermatids to spermatocytes in the vehicle-treated APX rats was 1:1.38; in the APX rats treated with 15 mg of TP it was 1:4.0 (the theoretically expected number). This study is probably the first to demonstrate: (1) the pharmacokinetics of TP, (2) the profile and quantity of T-immunoactivity in both serum and testicular tissue of APX and IC rats as well as APX rats treated with TP alone or in combination with FSH, (3) the direct correlation of serum T and ITT levels in treated APX rats (r = 0.9, p < 0.001) as well as in the IC rats (r = 0.9, p < 0.001), (4) the significant increase in the number of Type B spermatogonia, preleptotene and pachytene spermatocytes and round spermatids in TP-treated APX rats, (5) the correlation of the number of round spermatids formed in IC rats to ITT levels (r = 0.9, p < 0.001), and (6) the correlation of the quantitative maintenance of spermatogenesis with ITT levels (r = 0.7, p < 0.001) in the testes of TP-treated APX rats. These results provide direct experimental evidence for the key role of T in the spermatogenic process. ^

A manual of Judaism : detailed in a conversation between a rabbi and his pupil; being an introduction into the knowledge of the principles of the Jewish faith; for the use of the juvenile members of that persuasion

Joshua Van Oven

Insights into the biology of lymphatic metastasis

Recent data suggest that the generation of new lymphatic vessels (i.e. lymphangiogenesis) may be a rate-limiting step in the dissemination of tumor cells to regional lymph nodes. However, efforts to study the cellular and molecular interactions that take place between tumor cells and lymphatic endothelial cells have been limited due to a lack of lymphatic endothelial cell lines available for study. ^ I have used a microsurgical approach to establish conditionally immortalized lymphatic endothelial cell lines from the afferent mesenteric lymphatic vessels of mice. Characterization of lymphatic endothelial cells, and tumor-associated lymphatic vessels revealed high expression levels of VCAM-1, which is known to facilitate adhesion of some tumor cells to vascular endothelial cells. Further investigation revealed that murine melanoma cells selected for high expression of α4, a counter-receptor for VCAM-1, demonstrated enhanced adhesion to lymphatic endothelial cells in vitro, and increased tumorigenicity and lymphatic metastasis in vivo, despite similar lymphatic vessel numbers. ^ Next, I examined the effects of growth factors that regulate lymphangiogenesis, and report that several growth factors are capable of activating survival and proliferation pathways of lymphatic endothelial cells. The dual protein tyrosine kinase inhibitor AEE788 (EGFR and VEGFR-2) inhibited the activation of Akt and MAPK in lymphatic endothelial cells responding to multiple growth factors. Moreover, oral treatment of mice with AEE788 decreased lymphatic vessel density and production of lymphatic metastasis by human colon cancer cells growing in the cecum of nude mice. ^ In the last set of experiments, I investigated the surgical management of lymphatic metastasis using a novel model of sentinel lymphadenectomy in live mice bearing subcutaneous B16-BL6 melanoma. The data demonstrate that this procedure when combined with wide excision of the primary melanoma, significantly enhanced survival of syngeneic C57BL/6 mice. ^ Collectively, these results indicate that the production of lymphatic metastasis depends on lymphangiogenesis, tumor cell adhesion to lymphatic endothelial cells, and proliferation of tumor cells in lymph nodes. Thus, lymphatic metastasis is a multi-step, complex, and active process that depends upon multiple interactions between tumor cells and tumor associated lymphatic endothelial cells. ^

New insights into the role of the duodenal vitamin D receptor in calcium homeostasis

It is generally believed that 1,25(OH)2D3, bound to its receptor (VDR) contributes to calcium homeostasis by regulating active calcium absorption in the proximal small intestine. However, studying patients with hereditary vitamin D-resistant rickets (HVDRR) provided investigators with a better understanding of VDR's role in calcium homeostasis. HVDRR patients have inactivating mutations in the VDR, and as a consequence they develop hypocalcemia, hyperparathyroidism and severe rickets. However, these phenotypes can be corrected if the patients are given IV infusions of calcium or dietary calcium. This raises the question of what is the physiological significance of VDR-regulated active calcium absorption if calcium homeostasis can be restored independently of the VDR. ^ In order to distinguish the contribution of VDR in the proximal small intestine to overall calcium homeostasis, I generated transgenic mice expressing the human VDR (hVDR) exclusively in the proximal small intestine of mVDR-/- mice by using an hVDR-expressing transgene driven by the duodenal-specific adenosine deaminase enhancer (hVDR+/mVDR-/-). hVDR+/mVDR-/- mice expressed transcriptionally active hVDR only in the proximal small intestine and responded to 1,25(OH)2D3 by up-regulating expression of TRPV6 and calbindin D9K, genes involved in calcium absorption. Furthermore, ligated duodenal loop assays determined that calcium absorption in hVDR+/mVDR-/- mice was as responsive to 1,25(OH)2D3 as in WT mice. Despite having a functional hVDR in the proximal small intestine, hVDR+/mVDR-/- mice were hypocalcemic, had hyperparathyroidism, and were rachitic when fed a normal rodent diet at weaning, as were the mVDR-/- mice. However, when fed a high calcium, phosphorus, and lactose diet (rescue diet), the hVDR+/mVDR-/- mice responded more effectively than the mVDR-/- mice by down-regulation of parathyroid hormone production and by a greater increase in bone mineralization. Furthermore, when three-month-old rachitic mice were fed a rescue diet for 3 weeks, serum calcium and bone mineral content were normalized in hVDR+/mVDR-/- mice, but not in mVDR-/- mice. ^ In conclusion, hVDR expression enabled young mice to better use the rescue diet than mVDR-/- mice. Expression of transgenic hVDR also protected the ability of older mice to respond to the rescue diet despite the absence of the VDR elsewhere in the intestinal tract. I propose that because hVDR+/mVDR-/- mice responded better than mVDR-/- mice to the rescue diet, it is likely that VDR expression in the proximal small intestine is necessary in nutritional (insufficient dietary calcium) and physiological (age) conditions when passive calcium absorption is inadequate. ^

MOLECULAR AND GENOMIC BASED INSIGHTS INTO THE EVOLUTION OF ENTEROCOCCUS FAECIUM FROM COMMENSAL TO HOSPITAL-ADAPTED PATHOGEN

The basis for the recent transition of Enterococcus faecium from a primarily commensal organism to one of the leading causes of hospital-acquired infections in the United States is not yet understood. To address this, the first part of my project assessed isolates from early outbreaks in the USA and South America using sequence analysis, colony hybridizations, and minimal inhibitory concentrations (MICs) which showed clinical isolates possess virulence and antibiotic resistance determinants that are less abundant or lacking in community isolates. I also revealed that the level of ampicillin resistance increased over time in clinical strains. By sequencing the pbp5 gene, I demonstrated an ~5% difference in the pbp5 gene between strains with MICs <4ug/ml and those with MICs >4µg/ml, but no specific sequence changes correlated with increases in MICs within the latter group. A 3-10% nucleotide difference was also seen in three other genes analyzed, which suggested the existence of two distinct subpopulations of E. faecium. This led to the second part of my project analyzing concatenated core gene sequences, SNPs, the 16S rRNA, and phylogenetics of 21 E. faecium genomes confirming two distinct clades; a community-associated (CA) clade and hospital-associated (HA) clade. Molecular clock calculations indicate that these two clades likely diverged ~ 300,000 to > 1 million years ago, long before the modern antibiotic era. Genomic analysis also showed that, in addition to core genomic differences, HA E. faecium harbor specific accessory genetic elements that may confer selection advantages over CA E. faecium. The third part of my project discovered 6 E. faecium genes with the newly identified “WxL” domain. My analyses, using RT-PCR, western blots, patient sera, whole-cell ELISA, and immunogold electron microscopy, indicated that E. faecium WxL genes exist in operons, encode bacterial cell surface localized proteins, that WxL proteins are antigenic in humans, and are more exposed on the surface of clinical isolates versus community isolates (even though they are ubiquitous in both clades). ELISAs and BIAcore analyses also showed that proteins encoded by these operons bind several different host extracellular matrix proteins, as well as to each other, suggesting a novel cell-surface complex. In summary, my studies provide new insights into the evolution of E. faecium by showing that there are two distantly related clades; one being more successful in the hospital setting. My studies also identified operons encoding WxL proteins whose characteristics could also contribute to colonization and virulence within this species.

Linked Data at the Spanish National Library and the application of IFLA RDFS models

The Spanish National Library (Biblioteca Nacional de España1. BNE) and the Ontology Engineering Group2 of Universidad Politécnica de Madrid are working on the joint project ?Preliminary Study of Linked Data?, whose aim is to enrich the Web of Data with the BNE authority and bibliographic records. To this end, they are transforming the BNE information to RDF following the Linked Data principles3 proposed by Tim Berners Lee.

Using Virtual Reality in the teaching of manufacturing processes with material removal in CNC Machine-Tools

This paper presents a methodology for the incorporation of a Virtual Reality development applied to the teaching of manufacturing processes, namely the group of machining processes in numerical control of machine tools. The paper shows how it is possible to supplement the teaching practice through virtual machine-tools whose operation is similar to the 'real' machines while eliminating the risks of use for both users and the machines.

Incorporating reliability measurements into the predictions of a recommender system

In this paper we introduce the idea of using a reliability measure associated to the predic- tions made by recommender systems based on collaborative filtering. This reliability mea- sure is based on the usual notion that the more reliable a prediction, the less liable to be wrong. Here we will define a general reliability measure suitable for any arbitrary recom- mender system. We will also show a method for obtaining specific reliability measures specially fitting the needs of different specific recommender systems.

A Development Methodology to Facilitate the Integration of Smart Spaces into the Web of Things

How to create or integrate large Smart Spaces (considered as mash-ups of sensors and actuators) into the paradigm of ?Web of Things? has been the motivation of many recent works. A cutting-edge approach deals with developing and deploying web-enabled embedded devices with two major objectives: 1) to integrate sensor and actuator technologies into everyday objects, and 2) to allow a diversity of devices to plug to Internet. Currently, developers who want to use this Internet-oriented approach need have solid understanding about sensorial platforms and semantic technologies. In this paper we propose a Resource-Oriented and Ontology-Driven Development (ROOD) methodology, based on Model Driven Architecture (MDA), to facilitate to any developer the development and deployment of Smart Spaces. Early evaluations of the ROOD methodology have been successfully accomplished through a partial deployment of a Smart Hotel.

Online games for the teaching of mathematics

In this article we present a didactic experience developed by the GIE (Group of Educational Innovation) “Pensamiento Matemático” of the Polytechnics University of Madrid (UPM), in order to bring secondary students and university students closer to Mathematics. It deals with the development of a virtual board game called Mate-trivial. The mechanics of the game is to win points by going around the board which consists of four types of squares identified by colours: “Statistics and Probability”, “Calculus and Analysis”, “Algebra and Geometry” and “Arithmetic and Number Theory ”. When landing on a square, a question of its category is set out: a correct answer wins 200 points, if wrong it loses 100 points, and not answering causes no effect on the points, but all the same, two minutes out of the 20 minutes that each game lasts are lost. For the game to be over it is necessary, before those 20 minutes run out, to reach the central square and succeed in the final task: four chained questions, one of each type, which must be all answered correctly. It is possible to choose between two levels to play: Level 1, for pre-university students and Level 2 for university students. A prototype of the game is available at the website “Aula de Pensamiento Matemático” developed by the GIE: http://innovacioneducativa.upm.es/pensamientomatematico/. This activity lies within a set of didactic actions which the GIE is developing in the framework of the project “Collaborative Strategies between University and Secondary School Education for the teaching and learning of Mathematics: An Application to solve problems while playing”, a transversal project financed by the UPM.