Constitutively Active Canonical NF-κB Pathway Induces Severe Bone Loss in Mice

Physiologic osteoclastogenesis entails activation of multiple signal transduction pathways distal to the cell membrane receptor RANK. However, atypical osteoclastogenesis driven by pro-inflammatory stimuli has been described. We have reported recently a novel mechanism whereby endogenous mutational activation of the classical NF-κB pathway is sufficient to induce RANKL/RANK-independent osteoclastogenesis. Here we investigate the physiologic relevance of this phenomenon in vivo. Using a knock-in approach, the active form of IKK2, namely IKK2SSEE, was introduced into the myeloid lineage with the aid of CD11b-cre mice. Phenotypic assessment revealed that expression of IKK2SSEE in the myeloid compartment induced significant bone loss in vivo. This observation was supported by a dramatic increase in the number and size of osteoclasts in trabecular regions, elevated levels of circulating TRACP-5b, and reduced bone volume. Mechanistically, we observed that IKK2SSEE induced high expression of not only p65 but also p52 and RelB; the latter two molecules are considered exclusive members of the alternative NF-κB pathway. Intriguingly, RelB and P52 were both required to mediate the osteoclastogenic effect of IKK2SSEE and co-expression of these two proteins was sufficient to recapitulate osteoclastogenesis in the absence of RANKL or IKK2SSEE. Furthermore, we found that NF-κB2/p100 is a potent inhibitor of IKK2SSEE-induced osteoclastogenesis. Deletion of p52 enabled more robust osteoclast formation by the active kinase. In summary, molecular activation of IKK2 may play a role in conditions of pathologic bone destruction, which may be refractory to therapeutic interventions targeting the proximal RANKL/RANK signal

Careers of an elite cohort of U.S. basic life science postdoctoral fellows and the influence of their mentor's citation record

<p>Abstract</p> <p>Background</p> <p>There is general agreement that the number of U.S. science PhDs being trained far exceeds the number of future academic positions. One suggested approach to this problem is to significantly reduce the number of PhD positions. A counter argument is that students are aware of the limited academic positions but have chosen a PhD track because it opens other, non-academic, opportunities. The latter view requires that students have objective information about what careers options will be available for them.</p> <p>Methods</p> <p>The scientific careers of the 1992-94 cohort of NIH National Institute of General Medical Sciences (NIGMS) Kirchstein-NRSA F32 postdoctoral fellows (PD) was determined by following their publications (PubMed), grants (NIH and NSF), and faculty and industry positions through 2009. These basic life science PDs receive support through individual grant applications and represent the most successful class of NIH PDs as judged by academic careers and grants. The sex dependence of the career and grant success and the influence of the PD mentor's citation record were also determined</p> <p>Results</p> <p>Of the 439 1992-94 NIGMS F32 fellows, the careers of 417 could be determined. Although females had significantly higher rates of dropping out of science (22% females, 9% males) there was no significant difference in the fraction of females that ended up as associate or full professors at research universities (22.8% females, 29.1% for males). More males then females ended up in industry (34% males, 22% females). Although there was no significant correlation between male grant success and their mentor's publication record (h index, citations, publications), there was a significant correlation for females. Females whose mentor's h index was in the top quartile were nearly 3 times as likely to receive a major grant as those whose mentors were in the bottom quartile (38.7% versus 13.3%).</p> <p>Conclusions</p> <p>Sixteen years after starting their PD, only 9% of males had dropped out of science. More females (28%) have dropped out of science, primarily because fewer went into industry positions. The mentor's publication record does not affect the future grant success of males but it has a dramatic effect on female grant success.</p

Fructooligosaccharide production by Penicillium expansum

Fructooligosaccharides (FOS) production by Penicillium expansum was evaluated. In a first stage, the best conditions for P. expansum growth and sporulation were established with potato/dextrose/ agar being the most suitable medium at between 22 and 25°C, giving good growth and good sporulation. The inocula from this medium were used for FOS production using shake-flask cultures, and yielded 0.58 g FOS/g sucrose (3.25 g FOS/l.h), demonstrating the potential of this strain for sucrose conversion to FOS.Fundação para a Ciência e a Tecnologia (FCT) - SFRH/BPD/38212/200

Volvulus as a complication of chronic intestinal pseudo-obstruction syndrome

Chronic intestinal pseudo-obstruction syndrome (CIPS) is a severe motility disorder of the gastrointestinal tract that presents with continuous or recurrent symptoms and signs of intestinal obstruction without evidence of a structural lesion occluding the intestinal lumen. Mechanical obstruction might occur in these patients as well but is typically difficult to distinguish from an exacerbation of CIPS. We report two pediatric cases in which mechanical obstruction by volvulus mimicked an exacerbation of CIPS, requiring surgical intervention. Conclusion: Awareness of the possibility of true mechanical obstruction in CIPS patients during an exacerbation episode is needed, as this is a severe condition and usually requires surgical intervention

Production of fructooligosaccharides and b-fructofuranosidase by batch and repeated batch fermentation with immobilized cells of Penicillium expansum

The production of fructooligosaccharides (FOS) and b-fructofuranosidase (FFase) by immobilized cells of Penicillium expansum was evaluated. In an initial stage, different low-cost materials including synthetic fiber, polyurethane foam, stainless steel sponge, loofah sponge, and cork oak were tested as carrier for the fungus immobilization. Additionally, the influence of the inoculum age (1 or 3 weeks) on cells immobilization, FOS and FFase production was also verified. Synthetic fiber and polyurethane foam were the best materials for P. expansum immobilization (2.21 and 1.98 g/g carrier, respectively) and FOS production (120.3 and 104.8 g/l), and gave also high results of FFase activity (23.01 and 32.42 U/ml). Then, the production of FOS and FFase by repeated batch fermentation with P. expansum immobilized on synthetic fiber was studied, aiming to improve the batch fermentation results. The results obtained in this stage were very promising with FOS yields of 87, 72, and 44 %, in the 3 initial cycles (60 h), respectively; the FFase activity was constant throughout the process (6 cycles, 96 h). Repeated batch fermentation with immobilized cells of P. expansum was found as being a technology with great potential for FOS and FFase production on industrial scaleThe financial support from FCT, the Portuguese Foundation for Science and Technology (research grant SFRH/BPD/38212/2007) is gratefully acknowledged

Overweight and constipation in adolescents

Background: the association between overweight and gastrointestinal symptoms has been recently studied in the literature; however, few studies have evaluated the association between overweight and constipation in adolescents in a community-based sample. the aim of this study was to analyze the prevalence of constipation and its association with being overweight in a community-based survey with adolescents.Methods: This cross-sectional study included 1,077 adolescents who were enrolled in five schools in the city of Sao Jose dos Campos, Brazil. Constipation was defined according to modified and combined Rome III criteria for adolescents and adults. Being overweight was defined as a body mass index (BMI) that was equal to or greater than that of the 85(th) percentile for age and gender.Results: Constipation was diagnosed in 18.2% (196/1077) of the included adolescents. There was no significant difference in the prevalence of constipation in males and females who were both younger and older than 14 years. Fecal incontinence was observed in 25 adolescents, 22 (88.0%) of whom were diagnosed as being constipated. the prevalence of being overweight was found in 13.5% (145/1077) of the study population. the prevalence of constipation was observed to be similar in adolescents who were (19.4%; 28/144) and were not (18.0%; 168/933) overweight (p = 0.764; OR = 1.10). Fecal incontinence that was associated with constipation was more frequent in adolescents who were overweight (37.0%; 8/28) than in adolescents who were not overweight (8.5%; 14/168; p = 0.005; OR = 4.40).Conclusions: the prevalence of constipation was high among the investigated adolescents. There was no association between being overweight and constipation; however, an association between being overweight and fecal incontinence in constipated adolescents was confirmed.Universidade Federal de São Paulo, Div Pediat Gastroenterol, Escola Paulista Med, São Paulo, BrazilUniversidade Federal de São Paulo, Div Pediat Gastroenterol, Escola Paulista Med, São Paulo, BrazilWeb of Scienc

Fish Oil Enhances Recovery of Intestinal Microbiota and Epithelial Integrity in Chronic Rejection of Intestinal Transplant

The intestinal chronic rejection (CR) is the major limitation to long-term survival of transplanted organs. This study aimed to investigate the interaction between intestinal microbiota and epithelial integrity in chronic rejection of intestinal transplantation, and to find out whether fish oil enhances recovery of intestinal microbiota and epithelial integrity.. In addition, CR rats showed pronounced alteration of tight junction, depicted by marked changes in epithelial cell ultrastructure and redistribution of occuldin and claudins as well as disruption in TJ barrier function. Fish oil administration ameliorated disruption of epithelial integrity in CR, which was associated with an improvement of the mucosal structure leading to improved tight junctions.Our study have presented novel evidence that fish oil is involved in the maintenance of epithelial TJ integrity and recovery of gut microbiota, which may have therapeutic potential against CR in intestinal transplantation

The Mycobacterium tuberculosis Phagosome Is a HLA-I Processing Competent Organelle

Mycobacterium tuberculosis (Mtb) resides in a long-lived phagosomal compartment that resists maturation. The manner by which Mtb antigens are processed and presented on MHC Class I molecules is poorly understood. Using human dendritic cells and IFN-γ release by CD8+ T cell clones, we examined the processing and presentation pathway for two Mtb–derived antigens, each presented by a distinct HLA-I allele (HLA-Ia versus HLA-Ib). Presentation of both antigens is blocked by the retrotranslocation inhibitor exotoxin A. Inhibitor studies demonstrate that, after reaching the cytosol, both antigens require proteasomal degradation and TAP transport, but differ in the requirement for ER–golgi egress and new protein synthesis. Specifically, presentation by HLA-B8 but not HLA-E requires newly synthesized HLA-I and transport through the ER–golgi. Phenotypic analysis of the Mtb phagosome by flow organellometry revealed the presence of Class I and loading accessory molecules, including TAP and PDI. Furthermore, loaded HLA-I:peptide complexes are present within the Mtb phagosome, with a pronounced bias towards HLA-E:peptide complexes. In addition, protein analysis also reveals that HLA-E is enriched within the Mtb phagosome compared to HLA-A2. Together, these data suggest that the phagosome, through acquisition of ER–localized machinery and as a site of HLA-I loading, plays a vital role in the presentation of Mtb–derived antigens, similar to that described for presentation of latex bead-associated antigens. This is, to our knowledge, the first description of this presentation pathway for an intracellular pathogen. Moreover, these data suggest that HLA-E may play a unique role in the presentation of phagosomal antigens