A human pancreatic ribonuclease variant kills cancer cells by apoptosis and reduces the expression of P-glycoprotein in MDR cell lines

En aquesta tesi s'han estudiat les propietats antitumorals d'una variant de la ribonucleasa pancreàtica humana anomenada PE5 que incorpora un senyal de localització nuclear. Aquest estudi mostra que PE5 indueix l'apoptosi de les cèl·lules tractades i que aquesta mort és independent de l'activitat de p53. A més, l'efecte citotòxic no es veu afectat per un fenotip de resistència a múltiples drogues. Les dades també mostren que l'activitat citotòxica de PE5 és selectiva per a cèl·lules tumorals in vitro i que la capacitat citotòxica de les dues ribonucleases és semblant. S'ha estudiat l'efecte d'aquestes dues ribonucleases sobre el cicle cel·lular, l'activació de diferents caspases i l'expressió de proteïnes relacionades amb l'apoptosi i el cicle cel·lular. Els resultats indiquen que PE5 i l'onconasa maten les cèl·lules a través de mecanismes diferents. A més, PE5 però no l'onconasa, redueix l'acumulació de glicoproteïna-P en dues línies cel·lulars resistents a múltiples drogues.

Brief and precarious lives: Infant mortality in contrasting sites from medieval and post-medieval England (AD 850-1859)

This study compares the infant mortality profiles of 128 infants from two urban and two rural cemetery sites in medieval England. The aim of this paper is to assess the impact of urbanization and industrialization in terms of endogenous or exogenous causes of death. In order to undertake this analysis, two different methods of estimating gestational age from long bone lengths were used: a traditional regression method and a Bayesian method. The regression method tended to produce more marked peaks at 38 weeks, while the Bayesian method produced a broader range of ages and were more comparable with the expected "natural" mortality profiles. At all the sites, neonatal mortality (28-40 weeks) outweighed post-neonatal mortality (41-48 weeks) with rural Raunds Furnells in Northamptonshire, showing the highest number of neonatal deaths and post-medieval Spitalfields, London, showing a greater proportion of deaths due to exogenous or environmental factors. Of the four sites under study, Wharram Percy in Yorkshire showed the most convincing "natural" infant mortality profile, suggesting the inclusion of all births (i.e., stillbirths and unbaptised infants).

The pro-inflammatory oxidant hypochlorous acid induces Bax-dependent mitochondrial permeabilisation and cell death through AIF-/EndoG-dependent pathways

At sites of chronic inflammation, such as in the inflamed rheumatoid joint, activated neutrophils release hydrogen peroxide (H2O2) and the enzyme myeloperoxidase to catalyse the formation of hypochlorous acid (HOCl). 3-chlorotyrosine, a marker of HOCl in vivo, has been observed in synovial fluid proteins from rheumatoid arthritis patients. However the mechanisms of HOCl-induced cytotxicity are unknown. We determined the molecular mechanisms by which HOCl induced cell death in human mesenchymal progenitor cells (MPCs) differentiated into a chondrocytic phenotype as a model of human cartilage cells and show that HOCl induced rapid Bax conformational change, mitochondrial permeability and release of intra-mitochondrial pro-apoptotic proteins which resulted in nuclear translocation of AIF and EndoG. siRNA-mediated knockdown of Bax substantially prevented mitochondrial permeability, release of intra-mitochondrial pro-apoptotic proteins. Cell death was inhibited by siRNA-mediated knockdown of Bax, AIF or EndoG. Although we observed several biochemical markers of apoptosis, caspase activation was not detected either by western blotting, fluorescence activity assays or by using caspase inhibitors to inhibit cell death. This was further supported by findings that (1) in vitro exposure of recombinant human caspases to HOCl caused significant inhibition of caspase activity and (2) the addition of HOCl to staurosporine-treated MPCs inhibited the activity of cellular caspases. Our results show for the first time that HOCl induced Bax-dependent mitochondrial permeability which led to cell death without caspase activity by processes involving AIF/EndoG-dependent pathways. Our study provides a novel insight into the potential mechanisms of cell death in the inflamed human joint. (c) 2006 Elsevier Inc. All rights reserved.

The citrus flavanone naringenin inhibits inflammatory signalling in glial cells and protects against neuroinflammatory injury

Neuroinflammation plays an integral role in the progression of neurodegeneration. In this study we investigated the anti-inflammatory effects of different classes of flavonoids (flavanones, flavanols and anthocyanidins) in primary mixed glial cells. We found that the flavanones naringenin and hesperetin and the flavols (+)-catechin and (-)-epicatechin, but not the anthocyanidins cyanidin and pelargonidin, attenuated LPS/IFN-gamma-induced TNF-alpha production in glial cells. Naringenin also inhibited LPS/IFN-gamma-induced iNOS expression and nitric oxide production in glial cells, thus showing the strongest antiinflammatory activity among all flavonoids tested. Moreover, naringenin protected against inflammatory-induced neuronal death in a primary neuronal-glial co-culture system. Naringenin also inhibited LPS/IFN-gamma-induced p38 mitogen-activated protein kinase (MAPK) phosphorylation and downstream signal transducer and activator of transcription-1 (STAT-1) in LPS/IFN-gamma stimulated primary mixed glial cells. Taken together, our results suggest that naringenin may produce an anti-inflammatory effect in LPS/IFN-gamma stimulated glial cells that may be due to its interaction with p38 signalling cascades and the STAT-I trascription factor. (C) 2009 Elseiver Inc. All rights reserved.

Artichoke leaf extract (Cynara scolymus) reduces plasma cholesterol in otherwise healthy hypercholesterolemic adults: A randomized, double blind placebo controlled trial

Cardiovascular diseases are the chief causes of death in the UK, and are associated with high circulating levels of total cholesterol in the plasma. Artichoke leaf extracts (ALEs) have been reported to reduce plasma lipids levels, including total cholesterol, although high quality data is lacking. The objective of this trial was to assess the effect of ALE on plasma lipid levels and general well-being in otherwise healthy adults with mild to moderate hypercholesterolemia. 131 adults were screened for total plasma cholesterol in the range 6.0-8.0 mmol/l, with 75 suitable volunteers randomised onto the trial. Volunteers consumed 1280 mg of a standardised ALE, or matched placebo, daily for 12 weeks. Plasma total cholesterol decreased in the treatment group by an average of 4.2% (from 7.16 (SD 0.62) mmol/l to 6.86 (SD 0.68) mmol/l) and increased in the control group by an average of 1.9% (6.90 (SD 0.49) mmol/l to 7.03 (0.61) mmol/l), the difference between groups being statistically significant (p = 0.025). No significant differences between groups were observed for LDL cholesterol, HDL cholesterol or triglyceride levels. General well-being improved significantly in both the treatment (11%) and control groups (9%) with no significant differences between groups. In conclusion, ALE consumption resulted in a modest but favourable statistically significant difference in total cholesterol after 12 weeks. In comparison with a previous trial, it is suggested that the apparent positive health status of the study population may have contributed to the modesty of the observed response. (C) 2008 Elsevier GmbH. All rights reserved.

Neuroprotective effects of hesperetin in mouse primary neurones are independent of CREB activation

Dietary flavonoids, including the citrus flavanone hesperetin, may have stimulatory, effects on cytoprotective intracellular signalling pathways. In primary mouse cortical neurone cultures, but not SH-SY5Y human neuroblastoma cells or human primary dermal fibroblasts (Promocells), hesperetin (100-300 nM, 15 min) caused significant increases in the level of ERK1/2 phosphorylation, but did not increase CREB phosphorylation. Administration of hesperetin for 18 h did not alter gene expression driven by the cyclic AMP response element (CRE), assessed using a luciferase reporter system, but 300 nM hesperetin partially reversed staurosporine-induced cell death in primary neurones. Our data show that hesperetin is a neuroprotective compound at concentrations where antioxidant effects are unlikely to predominate. The effects of hesperetin are cell-type dependent and, unlike the flavanol (-)epicatechin, neuroprotection in vitro is not associated with enhanced CREB phosphorylation or CRE-mediated gene expression. (C) 2008 Elsevier Ireland Ltd. All rights reserved.

Substituted titanocenes induce caspase-dependent apoptosis in human epidermoid carcinoma cells in vitro and exhibit antitumour activity in vivo

Titanocene compounds are a novel series of agents that exhibit cytotoxic effects in a variety of human cancer cells in vitro and in vivo. In this study, the antiproliferative activity of two titanocenes (Titanocenes X and Y) was evaluated in human epidermoid cancer cells in vitro. Titanocenes X and Y induce apoptotic cell death in epidermoid cancer cells, with IC50 values that are comparable to cisplatin. Characterisation of the cell death pathway induced by titanocene compounds in A431 cells revealed that apoptosis is preceded by cell cycle arrest and the inhibition of cell proliferation. The induction of apoptosis is dependent on the activation of caspase-3 and -7 but not caspase-8. Furthermore, the antitumour activity of Titanocene Y was tested in an A431 xenograft model of epidermoid cancer. Results indicate that Titanocene Y significantly reduced the growth of A431 xenografts with an antitumour effect similar to cisplatin. These results suggest that titanocenes represent a novel series of promising antitumour agents.

Childhood obesity: should primary school children be routinely screened? A systematic review and discussion of the evidence

Background: Population monitoring has been introduced in UK primary schools in an effort to track the growing obesity epidemic. It has been argued that parents should be informed of their child's results, but is there evidence that moving from monitoring to screening would be effective? We describe what is known about the effectiveness of monitoring and screening for overweight and obesity in primary school children and highlight areas where evidence is lacking and research should be prioritised. Design: Systematic review with discussion of evidence gaps and future research. Data sources: Published and unpublished studies ( any language) from electronic databases ( inception to July 2005), clinical experts, Primary Care Trusts and Strategic Health Authorities, and reference lists of retrieved studies. Review methods: We included any study that evaluated measures of overweight and obesity as part of a population-level assessment and excluded studies whose primary outcome measure was prevalence. Results: There were no trials assessing the effectiveness of monitoring or screening for overweight and obesity. Studies focussed on the diagnostic accuracy of measurements. Information on the attitudes of children, parents and health professionals to monitoring was extremely sparse. Conclusions: Our review found a lack of data on the potential impact of population monitoring or screening for obesity and more research is indicated. Identification of effective weight reduction strategies for children and clarification of the role of preventative measures are priorities. It is difficult to see how screening to identify individual children can be justified without effective interventions.

Theory of mind in children with traumatic brain injury

Objective: This study was designed to examine the existence of deficits in mentalizing or theory of mind (ToM) in children with traumatic brain injury (TBI). Research design: ToM functioning was assessed in 12 children aged 6-12 years with TBI and documented frontal lobe damage and compared to 12 controls matched for age, sex and verbal ability. Brief measures of attention and memory were also included. Main outcome and results: The TBI group was significantly impaired relative to controls on the advanced ToM measure and a measure of basic emotion recognition. No difference was found in a basic measure of ToM. Conclusion: Traumatic brain damage in childhood may disrupt the developmental acquisition of emotion recognition and advanced ToM skills. The clinical and theoretical importance of these findings is discussed and the implications for the assessment and treatment of children who have experienced TBI are outlined.

Recalled relationships with parents and perceptions of professional support in mothers of infants treated for cleft lip

This study examined whether individual differences in perception of the quality of professional support available at a time of stress may be associated with security of attachment. We developed a new measure of parents' perceptions of emotional and practical support provided by a wide range of professionals involved in the treatment of infants with cleft lip. it showed good internal reliability and stability over 4 months. Mothers of 102 infants with cleft lip, with or without cleft palate, completed the measure at 2 and 6 months, together with the Parental Bonding Instrument and the General Health Questionnaire. Mean scores reflecting how much they could trust or talk frankly, or share their worst fears, with professionals, and the extent to which they saw them as a source of useful information or practical help, were lower among mothers with recollections of low maternal care in childhood, or high control. This was the case at 2 and 6 months, and there were some indications of an increasing contribution of low maternal care from 2 to 6 months. The associations were not explained by current depression. Further research is needed to clarify the role of attachment processes in parents' responses to serious medical conditions in their children, and into the implications for the way professionals in paediatric services provide support.

Measles vaccination and antibody response in autism spectrum disorders

Objective: To test the hypothesis that measles vaccination was involved in the pathogenesis of autism spectrum disorders (ASD) as evidenced by signs of a persistent measles infection or abnormally persistent immune response shown by circulating measles virus or raised antibody titres in children with ASD who had been vaccinated against measles, mumps and rubella (MMR) compared with controls. Design: Case-control study, community based. Methods: A community sample of vaccinated children aged 10-12 years in the UK with ASD (n = 98) and two control groups of similar age, one with special educational needs but no ASD (n = 52) and one typically developing group (n = 90), were tested for measles virus and antibody response to measles in the serum. Results: No difference was found between cases and controls for measles antibody response. There was no dose-response relationship between autism symptoms and antibody concentrations. Measles virus nucleic acid was amplified by reverse transcriptase-PCR in peripheral blood mononuclear cells from one patient with autism and two typically developing children. There was no evidence of a differential response to measles virus or the measles component of the MMR in children with ASD, with or without regression, and controls who had either one or two doses of MMR. Only one child from the control group had clinical symptoms of possible enterocolitis. Conclusion: No association between measles vaccination and ASD was shown.

Howard Barker’s ‘monstrous assaults’: eroticism, death and the antique text

Howard Barker is a writer who has made several notable excursions into what he calls ‘the charnel house…of European drama.’ David Ian Rabey has observed that a compelling property of these classical works lies in what he calls ‘the incompleteness of [their] prescriptions’, and Barker’s Women Beware Women (1986), Seven Lears (1990) and Gertrude: The Cry (2002), are in turn based around the gaps and interstices found in Thomas Middleton’s Women Beware Women (c1627), Shakespeare’s King Lear (c1604) and Hamlet (c1601) respectively. This extends from representing the missing queen from King Lear, who Barker observes, ‘is barely quoted even in the depths of rage or pity’, to his new ending for Middleton’s Jacobean tragedy and the erotic revivification of Hamlet’s mother. This paper will argue that each modern reappropriation accentuates a hidden but powerful feature in these Elizabethan and Jacobean plays – namely their clash between obsessive desire, sexual transgression and death against the imposed restitution of a prescribed morality. This contradiction acts as the basis for Barker’s own explorations of eroticism, death and tragedy. The paper will also discuss Barker’s project for these ‘antique texts’, one that goes beyond what he derisively calls ‘relevance’, but attempts instead to recover ‘smothered genius’, whereby the transgressive is ‘concealed within structures that lend an artificial elegance.’ Together with Barker’s own rediscovery of tragedy, the paper will assert that these rewritings of Elizabethan and Jacobean drama expose their hidden, yet unsettling and provocative ideologies concerning the relationship between political corruption / justice through the power of sexuality (notably through the allure and danger of the mature woman), and an erotics of death that produces tragedy for the contemporary age.

A specific group of genes respond to cold dehydration stress in cut Alstroemeria flowers whereas ambient dehydration stress accelerates developmental senescence expression patterns

Petal development and senescence entails a normally irreversible process. It starts with petal expansion and pigment production, and ends with nutrient remobilization and ultimately cell death. In many species this is accompanied by petal abscission. Post-harvest stress is an important factor in limiting petal longevity in cut flowers and accelerates some of the processes of senescence such as petal wilting and abscission. However, some of the effects of moderate stress in young flowers are reversible with appropriate treatments. Transcriptomic studies have shown that distinct gene sets are expressed during petal development and senescence. Despite this, the overlap in gene expression between developmental and stress-induced senescence in petals has not been fully investigated in any species. Here a custom-made cDNA microarray from Alstroemeria petals was used to investigate the overlap in gene expression between developmental changes (bud to first sign of senescence) and typical post-harvest stress treatments. Young flowers were stressed by cold or ambient temperatures without water followed by a recovery and rehydration period. Stressed flowers were still at the bud stage after stress treatments. Microarray analysis showed that ambient dehydration stress accelerates many of the changes in gene expression patterns that would normally occur during developmental senescence. However, a higher proportion of gene expression changes in response to cold stress were specific to this stimulus and not senescence related. The expression of 21 transcription factors was characterized, showing that overlapping sets of regulatory genes are activated during developmental senescence and by different stresses.