1,515 research outputs found

    Scientists’ Warning on Climate Change and Medicinal Plants

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    The recent publication of a World Scientists’ Warning to Humanity highlighted the fact that climate change, absent strenuous mitigation or adaptation efforts, will have profound negative effects for humanity and other species, affecting numerous aspects of life. In this paper, we call attention to one of these aspects, the effects of climate change on medicinal plants. These plants provide many benefits for human health, particularly in communities where Western medicine is unavailable. As for other species, their populations may be threatened by changing temperature and precipitation regimes, disruption of commensal relationships, and increases in pests and pathogens, combined with anthropogenic habitat fragmentation that impedes migration. Additionally, medicinal species are often harvested unsustainably, and this combination of pressures may push many populations to extinction. A second issue is that some species may respond to increased environmental stresses not only with declines in biomass production but with changes in chemical content, potentially affecting quality or even safety of medicinal products. We therefore recommend actions including conservation and local cultivation of valued plants, sustainability training for harvesters and certification of commercial material, preservation of traditional knowledge, and programs to monitor raw material quality, in addition to, of course, efforts to mitigate climate change

    Randomized controlled trial of mailed Nicotine Replacement Therapy to Canadian smokers: study protocol

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    <p>Abstract</p> <p>Background</p> <p>Considerable public health efforts are ongoing Canada-wide to reduce the prevalence of smoking in the general population. From 1985 to 2005, smoking rates among adults decreased from 35% to 19%, however, since that time, the prevalence has plateaued at around 18-19%. To continue to reduce the number of smokers at the population level, one option has been to translate interventions that have demonstrated clinical efficacy into population level initiatives. Nicotine Replacement Therapy (NRT) has a considerable clinical research base demonstrating its efficacy and safety and thus public health initiatives in Canada and other countries are distributing NRT widely through the mail. However, one important question remains unanswered - do smoking cessation programs that involve mailed distribution of free NRT work? To answer this question, a randomized controlled trial is required.</p> <p>Methods/Design</p> <p>A single blinded, panel survey design with random assignment to an experimental and a control condition will be used in this study. A two-stage recruitment process will be employed, in the context of a general population survey with two follow-ups (8 weeks and 6 months). Random digit dialing of Canadian home telephone numbers will identify households with adult smokers (aged 18+ years) who are willing to take part in a smoking study that involves three interviews, with saliva collection for 3-HC/cotinine ratio measurement at baseline and saliva cotinine verification at 8-week and 6-month follow-ups (N = 3,000). Eligible subjects interested in free NRT will be determined at baseline (N = 1,000) and subsequently randomized into experimental and control conditions to receive versus not receive nicotine patches. The primary hypothesis is that subjects who receive nicotine patches will display significantly higher quit rates (as assessed by 30 day point prevalence of abstinence from tobacco) at 6-month follow-up as compared to subjects who do not receive nicotine patches at baseline.</p> <p>Discussion</p> <p>The findings from the proposed trial are timely and highly relevant as mailed distribution of NRT require considerable resources and there are limited public health dollars available to combat this substantial health concern. In addition, findings from this randomized controlled trial will inform the development of models to engage smokers to quit, incorporating proactive recruitment and the offer of evidence based treatment.</p> <p>Trial Registration</p> <p>ClinicalTrials.gov: <a href="http://www.clinicaltrials.gov/ct2/show/NCT01429129">NCT01429129</a></p

    Ethological principles predict the neuropeptides co-opted to influence parenting

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    Ethologists predicted that parental care evolves by modifying behavioural precursors in the asocial ancestor. As a corollary, we predict that the evolved mechanistic changes reside in genetic pathways underlying these traits. Here we test our hypothesis in female burying beetles, Nicrophorus vespilloides, an insect where caring adults regurgitate food to begging, dependent offspring. We quantify neuropeptide abundance in brains collected from three behavioural states: solitary virgins, individuals actively parenting or post-parenting solitary adults and quantify 133 peptides belonging to 18 neuropeptides. Eight neuropeptides differ in abundance in one or more states, with increased abundance during parenting in seven. None of these eight neuropeptides have been associated with parental care previously, but all have roles in predicted behavioural precursors for parenting. Our study supports the hypothesis that predictable traits and pathways are targets of selection during the evolution of parenting and suggests additional candidate neuropeptides to study in the context of parenting

    Esthesioneuroblastoma in pediatric and adolescent age. A report from the TREP project in cooperation with the Italian Neuroblastoma and Soft Tissue Sarcoma Committees

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    <p>Abstract</p> <p>Background</p> <p>Esthesioneuroblastoma (ENB) is a rare, aggressive tumor with no established treatment in children. We analyzed a series of pediatric ENB patients with the aim of improving our knowledge of this disease.</p> <p>Methods</p> <p>9 patients (6 males; age 0.9-18 years, median 9.9) were identified by searching the AIEOP (<it>Italian Association of Pediatric Hematology and Oncology</it>) registry and the national databases of rare tumors, soft tissue sarcomas (STS) and neuroblastomas. The data on the cases included in STS treatment protocols were collected prospectively and histology was centrally reviewed; the data and histology concerning the other children were reviewed for the purpose of this analysis.</p> <p>Results</p> <p>All tumors occurred in the sinonasal region with bone erosion (7 patients) and intracranial (4) or intraorbital (4) extension. Three patients were in Kadish stage B, and 6 in stage C. Complete tumor resection was very difficult to achieve, but adding chemotherapy and radiotherapy enabled tumor control in 8 patients. Response to chemotherapy was evident in 5/7 evaluable cases. Radiotherapy (48.5-60 Gy) was delivered in all children but one, due to early disease progression. With a median follow-up of 13.4 years (range 9.2-22.9), 7 patients are alive in 1<sup>st </sup>and one in 2nd complete remission. All surviving patients developed treatment-related sequelae, the most frequent being endocrine dysfunctions (4 patients) and craniofacial growth impairments (4 patients).</p> <p>Conclusions</p> <p>Our findings confirm that ENB in children has an aggressive presentation, but multimodal therapy can cure most patients. Our results are encouraging but future strategies must optimize treatment in terms of survival and related morbidities.</p

    Molecular mechanisms of drug resistance in natural Leishmania populations vary with genetic background

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    The evolution of drug-resistance in pathogens is a major global health threat. Elucidating the molecular basis of pathogen drug-resistance has been the focus of many studies but rarely is it known whether a drug-resistance mechanism identified is universal for the studied pathogen; it has seldom been clarified whether drug-resistance mechanisms vary with the pathogen's genotype. Nevertheless this is of critical importance in gaining an understanding of the complexity of this global threat and in underpinning epidemiological surveillance of pathogen drug resistance in the field. This study aimed to assess the molecular and phenotypic heterogeneity that emerges in natural parasite populations under drug treatment pressure. We studied lines of the protozoan parasite Leishmania (L.) donovani with differential susceptibility to antimonial drugs; the lines being derived from clinical isolates belonging to two distinct genetic populations that circulate in the leishmaniasis endemic region of Nepal. Parasite pathways known to be affected by antimonial drugs were characterised on five experimental levels in the lines of the two populations. Characterisation of DNA sequence, gene expression, protein expression and thiol levels revealed a number of molecular features that mark antimonial-resistant parasites in only one of the two populations studied. A final series of in vitro stress phenotyping experiments confirmed this heterogeneity amongst drug-resistant parasites from the two populations. These data provide evidence that the molecular changes associated with antimonial-resistance in natural Leishmania populations depend on the genetic background of the Leishmania population, which has resulted in a divergent set of resistance markers in the Leishmania populations. This heterogeneity of parasite adaptations provides severe challenges for the control of drug resistance in the field and the design of molecular surveillance tools for widespread applicability

    Celastrol inhibits aminoglycoside-induced ototoxicity via heat shock protein 32

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    Hearing loss is often caused by death of the mechanosensory hair cells of the inner ear. Hair cells are susceptible to death caused by aging, noise trauma, and ototoxic drugs, including the aminoglycoside antibiotics and the antineoplastic agent cisplatin. Ototoxic drugs result in permanent hearing loss for over 500 000 Americans annually. We showed previously that induction of heat shock proteins (HSPs) inhibits both aminoglycoside- and cisplatin-induced hair cell death in whole-organ cultures of utricles from adult mice. In order to begin to translate these findings into a clinical therapy aimed at inhibiting ototoxic drug-induced hearing loss, we have now examined a pharmacological HSP inducer, celastrol. Celastrol induced upregulation of HSPs in utricles, and it provided significant protection against aminoglycoside-induced hair cell death in vitro and in vivo. Moreover, celastrol inhibited hearing loss in mice receiving systemic aminoglycoside treatment. Our data indicate that the major heat shock transcription factor HSF-1 is not required for celastrol-mediated protection. HSP32 (also called heme oxygenase-1, HO-1) is the primary mediator of the protective effect of celastrol. HSP32/HO-1 inhibits pro-apoptotic c-Jun N-terminal kinase (JNK) activation and hair cell death. Taken together, our data indicate that celastrol inhibits aminoglycoside ototoxicity via HSP32/HO-1 induction

    Hsp90 middle domain phosphorylation initiates a complex conformational program to recruit the ATPase-stimulating cochaperone Aha1

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    Complex conformational dynamics are essential for function of the dimeric molecular cha- perone heat shock protein 90 (Hsp90), including transient, ATP-biased N-domain dimer- ization that is necessary to attain ATPase competence. The intrinsic, but weak, ATP hydrolyzing activity of human Hsp90 is markedly enhanced by the co-chaperone Aha1. However, the cellular concentration of Aha1 is substoichiometric relative to Hsp90. Here we report that initial recruitment of this cochaperone to Hsp90 is markedly enhanced by phosphorylation of a highly conserved tyrosine (Y313 in Hsp90α) in the Hsp90 middle domain. Importantly, phosphomimetic mutation of Y313 promotes formation of a transient complex in which both N- and C-domains of Aha1 bind to distinct surfaces of the middle domains of opposing Hsp90 protomers prior to ATP-directed N-domain dimerization. Thus, Y313 represents a phosphorylation-sensitive conformational switch, engaged early after client loading, that affects both local and long-range conformational dynamics to facilitate initial recruitment of Aha1 to Hsp90

    Oxaliplatin and protracted venous infusion of 5-fluorouracil in patients with advanced or relapsed 5-fluorouracil pretreated colorectal cancer

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    The purpose of this study was to evaluate the activity and safety of oxaliplatin and protracted venous infusion of 5-fluorouracil (PVI 5-FU) in patients with advanced or relapsed 5-FU pretreated colorectal cancer. 38 patients with advanced or metastatic colorectal carcinoma with documented progression on or within 6 months following 5-FU or thymidylate synthase inhibitor containing chemotherapy were recruited between June 1997 and September 2000. Oxaliplatin (100 mg m−2) was given every 2 weeks and PVI 5-FU (300 mg m−2day−1) was administered. Median age of patients was 61 years. 17 patients had >2 sites of disease involvement. 10 had received 5-FU based adjuvant chemotherapy. 16 received oxaliplatin and PVI 5-FU as second-line chemotherapy for advanced disease and 22 as third or subsequent lines. Median follow up was 6.1 months. The best achieved objective tumour response rate was 29% (11 partial responses 95% confidence interval [CI] = 15–46%). 20 patients (52.6%) had stable disease. The median duration of response was 3.9 months. Even for patients who had previously received both 5-FU and irinotecan (n= 22), 27.3% had partial response with oxaliplatin and PVI 5-FU. 37 patients had symptoms on entry into the study. 25 patients had pain, 10 had anorexia and 28 had lethargy. 64%, 70% and 17.9% had symptomatic improvement after treatment respectively. Grade 3–4 toxicities were anaemia 10.6%, neutropenia 2.6%, thrombocytopenia 5.2%, diarrhoea 18.9%, nausea and vomiting 2.7%, infection 5.4% and lethargy 37.8%. The median survival was 9.1 months. Probability of overall survival at 6 months was 58.4% (95% CI = 38.7–73.7%). The median failure-free survival was 4 months. Oxaliplatin and PVI 5FU is an active and well tolerated regimen in patients with heavily pre-treated advanced colorectal cancer. © 2001 Cancer Research Campaig

    Human colon cancer profiles show differential microRNA expression depending on mismatch repair status and are characteristic of undifferentiated proliferative states

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    <p>Abstract</p> <p>Background</p> <p>Colon cancer arises from the accumulation of multiple genetic and epigenetic alterations to normal colonic tissue. microRNAs (miRNAs) are small, non-coding regulatory RNAs that post-transcriptionally regulate gene expression. Differential miRNA expression in cancer versus normal tissue is a common event and may be pivotal for tumor onset and progression.</p> <p>Methods</p> <p>To identify miRNAs that are differentially expressed in tumors and tumor subtypes, we carried out highly sensitive expression profiling of 735 miRNAs on samples obtained from a statistically powerful set of tumors (n = 80) and normal colon tissue (n = 28) and validated a subset of this data by qRT-PCR.</p> <p>Results</p> <p>Tumor specimens showed highly significant and large fold change differential expression of the levels of 39 miRNAs including miR-135b, miR-96, miR-182, miR-183, miR-1, and miR-133a, relative to normal colon tissue. Significant differences were also seen in 6 miRNAs including miR-31 and miR-592, in the direct comparison of tumors that were deficient or proficient for mismatch repair. Examination of the genomic regions containing differentially expressed miRNAs revealed that they were also differentially methylated in colon cancer at a far greater rate than would be expected by chance. A network of interactions between these miRNAs and genes associated with colon cancer provided evidence for the role of these miRNAs as oncogenes by attenuation of tumor suppressor genes.</p> <p>Conclusion</p> <p>Colon tumors show differential expression of miRNAs depending on mismatch repair status. miRNA expression in colon tumors has an epigenetic component and altered expression that may reflect a reversion to regulatory programs characteristic of undifferentiated proliferative developmental states.</p

    Postcopulatory sexual selection

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    The female reproductive tract is where competition between the sperm of different males takes place, aided and abetted by the female herself. Intense postcopulatory sexual selection fosters inter-sexual conflict and drives rapid evolutionary change to generate a startling diversity of morphological, behavioural and physiological adaptations. We identify three main issues that should be resolved to advance our understanding of postcopulatory sexual selection. We need to determine the genetic basis of different male fertility traits and female traits that mediate sperm selection; identify the genes or genomic regions that control these traits; and establish the coevolutionary trajectory of sexes
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