325 research outputs found
Characterisation of feline renal cortical fibroblast cultures and their transcriptional response to transforming growth factor beta 1
Chronic kidney disease (CKD) is common in geriatric cats, and the most prevalent pathology is chronic tubulointerstitial inflammation and fibrosis. The cell type predominantly responsible for the production of extra-cellular matrix in renal fibrosis is the myofibroblast, and fibroblast to myofibroblast differentiation is probably a crucial event. The cytokine TGF-β1 is reportedly the most important regulator of myofibroblastic differentiation in other species. The aim of this study was to isolate and characterise renal fibroblasts from cadaverous kidney tissue of cats with and without CKD, and to investigate the transcriptional response to TGF-β1
Proteomics: in pursuit of effective traumatic brain injury therapeutics
Effective traumatic brain injury (TBI) therapeutics remain stubbornly elusive. Efforts in the field have been challenged by the heterogeneity of clinical TBI, with greater complexity among underlying molecular phenotypes than initially conceived. Future research must confront the multitude of factors comprising this heterogeneity, representing a big data challenge befitting the coming informatics age. Proteomics is poised to serve a central role in prescriptive therapeutic development, as it offers an efficient endpoint within which to assess post-TBI biochemistry. We examine rationale for multifactor TBI proteomic studies and the particular importance of temporal profiling in defining biochemical sequences and guiding therapeutic development. Lastly, we offer perspective on repurposing biofluid proteomics to develop theragnostic assays with which to prescribe, monitor and assess pharmaceutics for improved translation and outcome for TBI patients
Spatiotemporal patterns of population in mainland China, 1990 to 2010
According to UN forecasts, global population will increase to over 8 billion by 2025, with much of this anticipated population growth expected in urban areas. In China, the scale of urbanization has, and continues to be, unprecedented in terms of magnitude and rate of change. Since the late 1970s, the percentage of Chinese living in urban areas increased from ~18% to over 50%. To quantify these patterns spatially we use time-invariant or temporally-explicit data, including census data for 1990, 2000, and 2010 in an ensemble prediction model. Resulting multi-temporal, gridded population datasets are unique in terms of granularity and extent, providing fine-scale (~100 m) patterns of population distribution for mainland China. For consistency purposes, the Tibet Autonomous Region, Taiwan, and the islands in the South China Sea were excluded. The statistical model and considerations for temporally comparable maps are described, along with the resulting datasets. Final, mainland China population maps for 1990, 2000, and 2010 are freely available as products from the WorldPop Project website and the WorldPop Dataverse Repository
Association between HLA-DRB1 alleles polymorphism and hepatocellular carcinoma: a meta-analysis
<p>Abstract</p> <p>Background</p> <p>HLA-DRB1 allele polymorphisms have been reported to be associated with hepatocellular carcinoma susceptibility, but the results of these previous studies have been inconsistent. The purpose of the present study was to explore whether specific HLA-DRB1 alleles (DRB1*07, DRB1*12, DRB1*15) confer susceptibility to hepatocellular carcinoma.</p> <p>Methods</p> <p>Case-control studies on HLA-DRB1 alleles association with HCC were searched up to January 2010 through a systematic review of the literature. The odds ratios (ORs) of HLA-DRB1 allele distributions in patients with hepatocellular carcinoma were analyzed against healthy controls. The meta-analysis software REVMAN 5.0 was applied for investigating heterogeneity among individual studies and for summarizing all the studies. Meta-analysis was performed using fixed-effect or random-effect methods, depending on absence or presence of significant heterogeneity.</p> <p>Results</p> <p>Eight case-control studies were included in the final analysis. Among the 3 HLA-DRB1 alleles studied, DRB1*07 and DRB1*12 were significantly associated with the risk of HCC in the whole populations (OR = 1.65, 95% CI: 1.08-2.51, P = 0.02 and OR = 1.59, 95% CI: 1.09-2.32, P = 0.02, respectively). No significant association was established for DRB1*15 allele with HCC in the whole populations. Subgroup analysis by ethnicity showed that DRB1*07, DRB1*12 and DRB1*15 alleles significantly increased the risk of hepatocellular carcinoma in Asians (OR = 2.10, 95% CI: 1.06-4.14, P = 0.03; OR = 1.73, 95% CI: 1.17-2.57, P = 0.006 and <b><it>OR </it></b>= 2.88, <it><b>95%CI: 1</b></it>.77-4.69, P <<it><b>0.001</b></it>, respectively).</p> <p>Conclusion</p> <p>These results support the hypothesis that specific HLA-DRB1 alleles might influence the susceptibility of hepatocellular carcinoma. Large, multi-ethnic confirmatory and well designed studies are needed to determine the host genetic determinants of hepatocellular carcinoma.</p
Degradation and selective ligninolysis of wheat straw and banana stem for an efficient bioethanol production using fungal and chemical pretreatment
Rab11 Is Required for Epithelial Cell Viability, Terminal Differentiation, and Suppression of Tumor-Like Growth in the Drosophila Egg Chamber
The Drosophila egg chamber provides an excellent system in which to study the specification and differentiation of epithelial cell fates because all of the steps, starting with the division of the corresponding stem cells, called follicle stem cells, have been well described and occur many times over in a single ovary.Here we investigate the role of the small Rab11 GTPase in follicle stem cells (FSCs) and in their differentiating daughters, which include main body epithelial cells, stalk cells and polar cells. We show that rab11-null FSCs maintain their ability to self renew, even though previous studies have shown that FSC self renewal is dependent on maintenance of E-cadherin-based intercellular junctions, which in many cell types, including Drosophila germline stem cells, requires Rab11. We also show that rab11-null FSCs give rise to normal numbers of cells that enter polar, stalk, and epithelial cell differentiation pathways, but that none of the cells complete their differentiation programs and that the epithelial cells undergo premature programmed cell death. Finally we show, through the induction of rab11-null clones at later points in the differentiation program, that Rab11 suppresses tumor-like growth of epithelial cells. Thus, rab11-null epithelial cells arrest differentiation early, assume an aberrant cell morphology, delaminate from the epithelium, and invade the neighboring germline cyst. These phenotypes are associated with defects in E-cadherin localization and a general loss of cell polarity.While previous studies have revealed tumor suppressor or tumor suppressor-like activity for regulators of endocytosis, our study is the first to identify such activity for regulators of endocytic recycling. Our studies also support the recently emerging view that distinct mechanisms regulate junction stability and plasticity in different tissues
Cryptosporidium parvum, a potential cause of colic adenocarcinoma
<p>Abstract</p> <p>Background</p> <p>Cryptosporidiosis represents a major public health problem. This infection has been reported worldwide as a frequent cause of diarrhoea. Particularly, it remains a clinically significant opportunistic infection among immunocompromised patients, causing potentially life-threatening diarrhoea in HIV-infected persons. However, the understanding about different aspects of this infection such as invasion, transmission and pathogenesis is problematic. Additionally, it has been difficult to find suitable animal models for propagation of this parasite. Efforts are needed to develop reproducible animal models allowing both the routine passage of different species and approaching unclear aspects of <it>Cryptosporidium </it>infection, especially in the pathophysiology field.</p> <p>Results</p> <p>We developed a model using adult severe combined immunodeficiency (SCID) mice inoculated with <it>Cryptosporidium parvum </it>or <it>Cryptosporidium muris </it>while treated or not with Dexamethasone (Dex) in order to investigate divergences in prepatent period, oocyst shedding or clinical and histopathological manifestations. <it>C. muris</it>-infected mice showed high levels of oocysts excretion, whatever the chemical immunosuppression status. Pre-patent periods were 11 days and 9.7 days in average in Dex treated and untreated mice, respectively. Parasite infection was restricted to the stomach, and had a clear preferential colonization for fundic area in both groups. Among <it>C. parvum</it>-infected mice, Dex-treated SCID mice became chronic shedders with a prepatent period of 6.2 days in average. <it>C. parvum</it>-inoculated mice treated with Dex developed glandular cystic polyps with areas of intraepithelial neoplasia, and also with the presence of intramucosal adenocarcinoma.</p> <p>Conclusion</p> <p>For the first time <it>C. parvum </it>is associated with the formation of polyps and adenocarcinoma lesions in the gut of Dex-treated SCID mice. Additionally, we have developed a model to compare chronic <it>muris </it>and <it>parvum </it>cryptosporidiosis using SCID mice treated with corticoids. This reproducible model has facilitated the evaluation of clinical signs, oocyst shedding, location of the infection, pathogenicity, and histopathological changes in the gastrointestinal tract, indicating divergent effects of Dex according to <it>Cryptosporidium </it>species causing infection.</p
Drosophila TIEG Is a Modulator of Different Signalling Pathways Involved in Wing Patterning and Cell Proliferation
Acquisition of a final shape and size during organ development requires a
regulated program of growth and patterning controlled by a complex genetic
network of signalling molecules that must be coordinated to provide positional
information to each cell within the corresponding organ or tissue. The mechanism
by which all these signals are coordinated to yield a final response is not well
understood. Here, I have characterized the Drosophila ortholog
of the human TGF-β Inducible Early Gene 1 (dTIEG). TIEG are zinc-finger
proteins that belong to the Krüppel-like factor (KLF) family and were
initially identified in human osteoblasts and pancreatic tumor cells for the
ability to enhance TGF-β response. Using the developing wing of
Drosophila as “in vivo” model, the dTIEG
function has been studied in the control of cell proliferation and patterning.
These results show that dTIEG can modulate Dpp signalling. Furthermore, dTIEG
also regulates the activity of JAK/STAT pathway suggesting a conserved role of
TIEG proteins as positive regulators of TGF-β signalling and as mediators of
the crosstalk between signalling pathways acting in a same cellular context
Ghrelin Modulates the fMRI BOLD Response of Homeostatic and Hedonic Brain Centers Regulating Energy Balance in the Rat
The orexigenic gut-brain peptide, ghrelin and its G-protein coupled receptor, the growth hormone secretagogue receptor
1a (GHS-R1A) are pivotal regulators of hypothalamic feeding centers and reward processing neuronal circuits of the brain.
These systems operate in a cooperative manner and receive a wide array of neuronal hormone/transmitter messages and
metabolic signals. Functional magnetic resonance imaging was employed in the current study to map BOLD responses to
ghrelin in different brain regions with special reference on homeostatic and hedonic regulatory centers of energy balance.
Experimental groups involved male, ovariectomized female and ovariectomized estradiol-replaced rats. Putative modulation
of ghrelin signaling by endocannabinoids was also studied. Ghrelin-evoked effects were calculated as mean of the BOLD
responses 30 minutes after administration. In the male rat, ghrelin evoked a slowly decreasing BOLD response in all studied
regions of interest (ROI) within the limbic system. This effect was antagonized by pretreatment with GHS-R1A antagonist
JMV2959. The comparison of ghrelin effects in the presence or absence of JMV2959 in individual ROIs revealed significant
changes in the prefrontal cortex, nucleus accumbens of the telencephalon, and also within hypothalamic centers like the
lateral hypothalamus, ventromedial nucleus, paraventricular nucleus and suprachiasmatic nucleus. In the female rat, the
ghrelin effects were almost identical to those observed in males. Ovariectomy and chronic estradiol replacement had no
effect on the BOLD response. Inhibition of the endocannabinoid signaling by rimonabant significantly attenuated the
response of the nucleus accumbens and septum. In summary, ghrelin can modulate hypothalamic and mesolimbic
structures controlling energy balance in both sexes. The endocannabinoid signaling system contributes to the
manifestation of ghrelin’s BOLD effect in a region specific manner. In females, the estradiol milieu does not influence the
BOLD response to ghrelin
A strategy to discover new organizers identifies a putative heart organizer
Organizers are regions of the embryo that can both induce new fates and impart pattern on other regions. So far, surprisingly few organizers have been discovered, considering the number of patterned tissue types generated during development. This may be because their discovery has relied on transplantation and ablation experiments. Here we describe a new approach, using chick embryos, to discover organizers based on a common gene expression signature, and use it to uncover the anterior intestinal portal (AIP) endoderm as a putative heart organizer. We show that the AIP can induce cardiac identity from non-cardiac mesoderm and that it can pattern this by specifying ventricular and suppressing atrial regional identity. We also uncover some of the signals responsible. The method holds promise as a tool to discover other novel organizers acting during development
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