122 resultados para Human herpesvirus 4
Resumo:
A framework for understanding the complexity of cancer development was established by Hanahan and Weinberg in their definition of the hallmarks of cancer. In this review, we consider the evidence that parabens can enable development in human breast epithelial cells of 4/6 of the basic hallmarks, 1/2 of the emerging hallmarks and 1/2 of the enabling characteristics. Hallmark 1: parabens have been measured as present in 99% of human breast tissue samples, possess oestrogenic activity and can stimulate sustained proliferation of human breast cancer cells at concentrations measurable in the breast. Hallmark 2: parabens can inhibit the suppression of breast cancer cell growth by hydroxytamoxifen, and through binding to the oestrogen-related receptor gamma (ERR) may prevent its deactivation by growth inhibitors. Hallmark 3: in the 10nM to 1M range, parabens give a dose-dependent evasion of apoptosis in high-risk donor breast epithelial cells. Hallmark 4: long-term exposure (>20weeks) to parabens leads to increased migratory and invasive activity in human breast cancer cells, properties which are linked to the metastatic process. Emerging hallmark: methylparaben has been shown in human breast epithelial cells to increase mTOR, a key regulator of energy metabolism. Enabling characteristic: parabens can cause DNA damage at high concentrations in the short term but more work is needed to investigate long-term low-doses of mixtures. The ability of parabens to enable multiple cancer hallmarks in human breast epithelial cells provides grounds for regulatory review of the implications of the presence of parabens in human breast tissue.
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The aim of this study has been to characterize adult human somatic periodontium-derived stem cells (PDSCS) isolated from human periodontium and to follow their differentiation after cell culture. PDSCS were isolated from human periodontal tissue and cultured as spheres in serum-free medium. After 10 days the primary spheres were dissociated and the secondary spheres sub-cultured for another 1-2 weeks. Cells from different time points were analyzed, and immunohistochemical and electron microscopic investigations carried out. Histological analysis showed differentiation of spheres deriving from the PDSCS with central production of extracellular matrix beginning 3 days after sub-culturing. Isolated PDSCS developed pseudopodia which contained actin. Tubulin was found in the central portion of the cells. Pseudopodia between different cells anastomosed, indicating intercellular transport. Immunostaining for osteopontin demonstrated a positive reaction in primary spheres and within extracellular matrix vesicles after sub-culturing. In cell culture under serum-free conditions human PDSCS form spheres which are capable of producing extracellular matrix. Further investigations have do be carried out to investigate the capability of these cells to differentiate into osteogenic progenitor cells.
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Adult human neural crest-derived stem cells (NCSCs) are of extraordinary high plasticity and promising candidates for the use in regenerative medicine. Here we describe for the first time a novel neural crest-derived stem cell population within the respiratory epithelium of human adult inferior turbinate. In contrast to superior and middle turbinates, high amounts of source material could be isolated from human inferior turbinates. Using minimally-invasive surgery methods isolation is efficient even in older patients. Within their endogenous niche, inferior turbinate stem cells (ITSCs) expressed high levels of nestin, p75(NTR), and S100. Immunoelectron microscopy using anti-p75 antibodies displayed that ITSCs are of glial origin and closely related to nonmyelinating Schwann cells. Cultivated ITSCs were positive for nestin and S100 and the neural crest markers Slug and SOX10. Whole genome microarray analysis showed pronounced differences to human ES cells in respect to pluripotency markers OCT4, SOX2, LIN28, and NANOG, whereas expression of WDR5, KLF4, and c-MYC was nearly similar. ITSCs were able to differentiate into cells with neuro-ectodermal and mesodermal phenotype. Additionally ITSCs are able to survive and perform neural crest typical chain migration in vivo when transplanted into chicken embryos. However ITSCs do not form teratomas in severe combined immunodeficient mice. Finally, we developed a separation strategy based on magnetic cell sorting of p75(NTR) positive ITSCs that formed larger neurospheres and proliferated faster than p75(NTR) negative ITSCs. Taken together our study describes a novel, readily accessible source of multipotent human NCSCs for potential cell-replacement therapy.
Resumo:
Parkinson's disease (PD) is considered the second most frequent and one of the most severe neurodegenerative diseases, with dysfunctions of the motor system and with nonmotor symptoms such as depression and dementia. Compensation for the progressive loss of dopaminergic (DA) neurons during PD using current pharmacological treatment strategies is limited and remains challenging. Pluripotent stem cell-based regenerative medicine may offer a promising therapeutic alternative, although the medical application of human embryonic tissue and pluripotent stem cells is still a matter of ethical and practical debate. Addressing these challenges, the present study investigated the potential of adult human neural crest-derived stem cells derived from the inferior turbinate (ITSCs) transplanted into a parkinsonian rat model. Emphasizing their capability to give rise to nervous tissue, ITSCs isolated from the adult human nose efficiently differentiated into functional mature neurons in vitro. Additional successful dopaminergic differentiation of ITSCs was subsequently followed by their transplantation into a unilaterally lesioned 6-hydroxydopamine rat PD model. Transplantation of predifferentiated or undifferentiated ITSCs led to robust restoration of rotational behavior, accompanied by significant recovery of DA neurons within the substantia nigra. ITSCs were further shown to migrate extensively in loose streams primarily toward the posterior direction as far as to the midbrain region, at which point they were able to differentiate into DA neurons within the locus ceruleus. We demonstrate, for the first time, that adult human ITSCs are capable of functionally recovering a PD rat model.
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This placebo-controlled, randomised, double-blind, cross-over human feeding study aimed to determine the prebiotic effect of agave fructans. A total of thirty-eight volunteers completed this trial. The treatment consisted of 3 weeks' supplementation with 5 g/d of prebiotic agave fructan (Predilife) or equivalent placebo (maltodextrin), followed by a 2-week washout period following which subjects were crossed over to alternate the treatment arm for 3 weeks followed by a 2-week washout. Faecal samples were collected at baseline, on the last day of treatment (days 22 and 58) and washout (days 36 and 72), respectively. Changes in faecal bacterial populations, SCFA and secretory IgA were assessed using fluorescent in situ hybridisation, GC and ELISA, respectively. Bowel movements, stool consistencies, abdominal comfort and mood changes were evaluated by a recorded daily questionnaire. In parallel, the effect of agave fructans on different regions of the colon using a three-stage continuous culture simulator was studied. Predilife significantly increased faecal bifidobacteria (log10 9·6 (sd 0·4)) and lactobacilli (log10 7·7 (sd 0·8)) compared with placebo (log10 9·2 (sd 0·4); P = 0·00) (log10 7·4 (sd 0·7); P = 0·000), respectively. No change was observed for other bacterial groups tested, SCFA, secretory IgA, and PGE2 concentrations between the treatment and placebo. Denaturing gradient gel electrophoresis analysis indicated that bacterial communities were randomly dispersed and no significant differences were observed between Predilife and placebo treatments. The in vitro models showed similar increases in bifidobacterial and lactobacilli populations to that observed with the in vivo trial. To conclude, agave fructans are well tolerated in healthy human subjects and increased bifidobacteria and lactobacilli numbers in vitro and in vivo but did not influence other products of fermentation
Resumo:
The glycoprotein VI (GPVI)-Fc receptor γ (FcRγ) chain is the major platelet signaling receptor for collagen. Paradoxically, in a FeCl3 injury model, occlusion, but not initiation of thrombus formation, is delayed in GPVI-deficient and GPVI-depleted mice. In this study, we demonstrate that GPVI is a receptor for fibrin and speculate that this contributes to development of an occlusive thrombus. We observed a marked increase in tyrosine phosphorylation, including the FcRγ chain and Syk, in human and mouse platelets induced by thrombin in the presence of fibrinogen and the αIIbβ3 blocker eptifibatide. This was not seen in platelets stimulated by a protease activated receptor (PAR)-4 peptide, which is unable to generate fibrin from fibrinogen. The pattern of tyrosine phosphorylation was similar to that induced by activation of GPVI. Consistent with this, thrombin did not induce tyrosine phosphorylation of Syk and the FcRγ chain in GPVI-deficient mouse platelets. Mouse platelets underwent full spreading on fibrin but not fibrinogen, which was blocked in the presence of a Src kinase inhibitor or in the absence of GPVI. Spreading on fibrin was associated with phosphatidylserine exposure (procoagulant activity), and this too was blocked in GPVI-deficient platelets. The ectodomain of GPVI was shown to bind to immobilized monomeric and polymerized fibrin. A marked increase in embolization was seen following FeCl3 injury in GPVI-deficient mice, likely contributing to the delay in occlusion in this model. These results demonstrate that GPVI is a receptor for fibrin and provide evidence that this interaction contributes to thrombus growth and stability.
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Aluminium (Al) has been measured in human breast tissue, and may be a contributory factor in breast cancer development. At the 10th Keele meeting, we reported that long-term exposure to Al could increase migratory properties of oestrogen-responsive MCF-7 human breast cancer cells suggesting a role for Al in the metastatic process. We now report that long-term exposure (20–25 weeks) to Al chloride or Al chlorohydrate at 10−4 M or 10−5Mconcentrations can also increase themigration of oestrogen unresponsiveMDA-MB-231 human breast cancer cells as measured using time-lapse microscopy and xCELLigence technology. In parallel, Al exposure was found to give rise to increased secretion of active matrixmetalloproteinaseMMP9 as measured by zymography, and increased intracellular levels of activated MMP14 as measured by western immunoblotting. These results demonstrate that Al can increase migration of human breast cancer cells irrespective of their oestrogen responsiveness, and implicate alterations to MMPs as a potential mechanism worthy of further study.
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Use of underarm aluminium (Al)-based antiperspirant salts may be a contributory factor in breast cancer development. At the 10th Keele meeting, Al was reported to cause anchorage-independent growth and double strand DNA breaks in MCF10A immortalised non-transformed human breast epithelial cells. We now report that exposure of MCF10A cells to Al chloride or Al chlorohydrate also compromised DNA repair systems. Longterm (19–21 weeks) exposure to Al chloride or Al chlorohydrate at a 10−4 M concentration resulted in reduced levels of BRCA1 mRNA as determined by real-time RT-PCR and BRCA1 protein as determined by Western immunoblotting. Reduced levels of mRNA for other DNA repair genes (BRCA2, CHK1, CHK2, Rad51, ATR) were also observed using real-time RT-PCR. Loss of BRCA1 or BRCA2 gene function has long been associated with inherited susceptibility to breast cancer but these results suggest that exposure to aluminium-based antiperspirant salts may also reduce levels of these key components of DNA repair in breast epithelial cells. If Al can not only damage DNA but also compromise DNA repair systems, then there is the potential for Al to impact on breast carcinogenesis.
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Parents have large genetic and environmental influences on offspring’s cognition, behavior, and brain. These intergenerational effects are observed in mood disorders, with particularly robust association in depression between mothers and daughters. No studies have thus far examined the neural bases of these intergenerational effects in humans. Corticolimbic circuitry is known to be highly relevant in a wide range of processes including mood regulation and depression. These findings suggest that corticolimbic circuitry may also show matrilineal transmission patterns. We therefore examined human parent-offspring association in this neurocircuitry, and investigated the degree of association in gray matter volume between parent and offspring. We used voxel-wise correlation analysis in a total of 35 healthy families, consisting of parents and their biological offspring. We found positive associations of regional grey matter volume in the corticolimbic circuit including the amygdala, hippocampus, anterior cingulate cortex, and ventromedial prefrontal cortex between biological mothers and daughters. This association was significantly greater than mother-son, father-daughter, and father-son associations. The current study suggests that the corticolimbic circuitry, which has been implicated in mood regulation, shows a matrilineal specific transmission patterns. Our preliminary findings are consistent with what has been found behaviorally in depression, and may have clinical implications for disorders known to have dysfunction in mood regulation such as depression. Studies such as ours will likely bridge animal work examining gene expression in the brains and clinical symptom-based observations, and provide promising ways to investigate intergenerational transmission patterns in the human brain.
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Three well-characterized mitogen-activated protein kinase (MAPK) subfamilies are expressed in rodent and rabbit hearts, and are activated by pathophysiological stimuli. We have determined and compared the expression and activation of these MAPKs in donor and failing human hearts. The amount and activation of MAPKs was assessed in samples from the left ventricles of 4 unused donor hearts and 12 explanted hearts from patients with heart failure secondary to ischaemic heart disease. Total MAPKs or dually phosphorylated (activated) MAPKs were detected by Western blotting and MAPK activities were measured by in gel kinase assays. As in rat heart, c-Jun N-terminal kinases (JNKs) were detected in human hearts as bands corresponding to 46 and 54 kDa; p38-MAPK(s) was detected as a band corresponding to approximately 40 kDa, and extracellularly regulated kinases, ERK1 and ERK2, were detected as 44- and 42-kDa bands respectively. The total amounts of 54 kDa JNK, p38-MAPK and ERK2 were similar in all samples, although 46-kDa JNK was reduced in the failing hearts. However, the mean activities of JNKs and p38-MAPK(s) were significantly higher in failing heart samples than in those from donor hearts (P<0.05). There was no significant difference in phosphorylated (activated) ERKs between the two groups. In conclusion, JNKs, p38-MAPK(s) and ERKs are expressed in the human heart and the activities of JNKs and p38-MAPK(s) were increased in heart failure secondary to ischaemic heart disease. These data indicate that JNKs and p38-MAPKs may be important in human cardiac pathology.
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While a growing literature has analyzed the effects of parental migration on the educational outcomes of children left behind, this study is the first to highlight the importance of sibling interactions in such a context. Using panel data from the RUMiC Survey, we find that sibling influence on school performance is stronger among left- behind children. Hence, parental migration seems to trigger changes in familial roles and sibling effects among children. However, it is primarily older sisters who exhibit a positive influence on their younger siblings. We corroborate our results by performing a series of tests to mitigate endogeneity issues. The results from the analysis suggest that sibling effects in migrant households might be a mechanism shaping children’s outcomes and success and that adjustments within the family left behind have the potential to generate benefits – or reduce hardships – in response to parental migration.
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The Hugh Sinclair Unit of Human Nutrition (HSUHN) at the University of Reading was founded in October 1995 with the appointment of Christine Williams OBE as the first Hugh Sinclair Chair in Human Nutrition. This was made possible by the competitively won funds from the estate and legacy of the late Professor Hugh Macdonald Sinclair (1910–1990). The vision for the newly established HSUHN was to ‘strengthen the evidence base for dietary recommendations for prevention of degenerative chronic diseases’. This has remained the research focus of the HSUHN under the leadership of Professors Christine Williams (1995–2005), Ian Rowland (2006–2013) and Julie Lovegrove (2014-present). Our mission is to improve population health and evaluate mechanisms of action for the effects of dietary components on health, which reflects Hugh Sinclair’s life ambition within nutritional science. Over the past 20 years, the HSUHN has developed an international reputation within the nutrition science community, and in recognition of the 20th anniversary, this paper highlights Hugh Sinclair’s contributions to the field of nutrition and key research achievements by members of the Unit.
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The leaves of the olive plant (Olea europaea) are rich in polyphenols, of which oleuropein and hydroxytyrosol (HT) are most characteristic. Such polyphenols have been demonstrated to favourably modify a variety of cardiovascular risk factors. The aim of the present intervention was to investigate the influence of olive leaf extract (OLE) on vascular function and inflammation in a postprandial setting and to link physiological outcomes with absorbed phenolics. A randomised, double-blind, placebo-controlled, cross-over, acute intervention trial was conducted with eighteen healthy volunteers (nine male, nine female), who consumed either OLE (51 mg oleuropein; 10mg HT), or a matched control (separated by a 4-week wash out) on a single occasion. Vascular function was measured by digital volume pulse (DVP), while blood collected at baseline, 1, 3 and 6 h was cultured for 24 h in the presence of lipopolysaccharide in order to investigate effects on cytokine production. Urine was analysed for phenolic metabolites by HPLC. DVP-stiffness index and ex vivo IL-8 production were significantly reduced (P < 0.05) after consumption of OLE compared to the control. These effects were accompanied by the excretion of several phenolic metabolites, namely HT and oleuropein derivatives, which peaked in urine after 8-24 h. The present study provides the first evidence that OLE positively modulates vascular function and IL-8 production in vivo, adding to growing evidence that olive phenolics could be beneficial for health.
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European air quality legislation has reduced emissions of air pollutants across Europe since the 1970s, affecting air quality, human health and regional climate. We used a coupled composition-climate model to simulate the impacts of European air quality legislation and technology measures implemented between 1970 and 2010. We contrast simulations using two emission scenarios; one with actual emissions in 2010 and the other with emissions that would have occurred in 2010 in the absence of technological improvements and end-of-pipe treatment measures in the energy, industrial and road transport sectors. European emissions of sulphur dioxide, black carbon (BC) and organic carbon in 2010 are 53%, 59% and 32% lower respectively compared to emissions that would have occurred in 2010 in the absence of legislative and technology measures. These emission reductions decreased simulated European annual mean concentrations of fine particulate matter(PM2.5) by 35%, sulphate by 44%, BC by 56% and particulate organic matter by 23%. The reduction in PM2.5 concentrations is calculated to have prevented 80 000 (37 000–116 000, at 95% confidence intervals) premature deaths annually across the European Union, resulting in a perceived financial benefit to society of US$232 billion annually (1.4% of 2010 EU GDP). The reduction in aerosol concentrations due to legislative and technology measures caused a positive change in the aerosol radiative effect at the top of atmosphere, reduced atmospheric absorption and also increased the amount of solar radiation incident at the surface over Europe. We used an energy budget approximation to estimate that these changes in the radiative balance have increased European annual mean surface temperatures and precipitation by 0.45 ± 0.11 °C and by 13 ± 0.8 mm yr−1 respectively. Our results show that the implementation of European legislation and technological improvements to reduce the emission of air pollutants has improved air quality and human health over Europe, as well as having an unintended impact on the regional radiative balance and climate.