155 research outputs found

    A “Calvinist” Theory of Matter? Burgersdijk and Descartes on res extensa

    Get PDF
    In the Dutch debates on Cartesianism of the 1640s, a minority believed that some Cartesian views were in fact Calvinist ones. The paper argues that, among others, a likely precursor of this position is the Aristotelian Franco Burgersdijk (1590-1635), who held a reductionist view of accidents and of the essential extension of matter on Calvinist grounds. It seems unlikely that Descartes was unaware of these views. The claim is that Descartes had two aims in his Replies to Arnauld: to show the compatibility of res extensa and the Catholic transubstantiation but also to differentiate the res extensa from some views of matter explicitly defended by some Calvinists. The association with Calvinism will be eventually used polemically against Cartesianism, for example in France. The paper finally suggests that, notwithstanding the points of conflict, the affinities between the theologically relevant theories of accidents, matter and extension ultimately facilitated the dissemination of Cartesianism among the Calvinists

    Tubulin-binding dibenz[c,e]oxepines: Part 2 Structural variation and biological evaluation as tumour vasculature disrupting agents

    Get PDF
    5,7-Dihydro-3,9,10,11-tetramethoxybenz[c,e]oxepin-4-ol 1, prepared from a dibenzyl ether precursor via Pd-catalysed intramolecular direct arylation, possesses broad-spectrum in vitro cytotoxicity towards various tumour cell lines, and induces vascular shutdown, necrosis and growth delay in tumour xenografts in mice at sub-toxic doses. The biological properties of 1 and related compounds can be attributed to their ability to inhibit microtubule assembly at the micromolar level, by binding reversibly to the same site of the tubulin αβ-heterodimer as colchicine 2 and the allocolchinol, N-acetylcolchinol 4

    HPV vaccine: an overview of immune response, clinical protection, and new approaches for the future

    Get PDF
    Although long-term protection is a key-point in evaluating HPV-vaccine over time, there is currently inadequate information on the duration of HPV vaccine-induced immunity and on the mechanisms related to the activation of immune-memory. Longer-term surveillance in a vaccinated population is needed to identify waning immunity, evaluating any requirements for booster immunizations to assess vaccine efficacy against HPV-diseases. Current prophylactic vaccines have the primary end-points to protect against HPV-16 and 18, the genotypes more associated to cervical cancer worldwide. Nevertheless, data from many countries demonstrate the presence, at significant levels, of HPVs that are not included in the currently available vaccine preparations, indicating that these vaccines could be less effective in a particular area of the world. The development of vaccines covering a larger number of HPVs presents the most complex challenge for the future. Therefore, long term immunization and cross-protection of HPV vaccines will be discussed in light of new approaches for the future

    Prognostic model to predict postoperative acute kidney injury in patients undergoing major gastrointestinal surgery based on a national prospective observational cohort study.

    Get PDF
    Background: Acute illness, existing co-morbidities and surgical stress response can all contribute to postoperative acute kidney injury (AKI) in patients undergoing major gastrointestinal surgery. The aim of this study was prospectively to develop a pragmatic prognostic model to stratify patients according to risk of developing AKI after major gastrointestinal surgery. Methods: This prospective multicentre cohort study included consecutive adults undergoing elective or emergency gastrointestinal resection, liver resection or stoma reversal in 2-week blocks over a continuous 3-month period. The primary outcome was the rate of AKI within 7 days of surgery. Bootstrap stability was used to select clinically plausible risk factors into the model. Internal model validation was carried out by bootstrap validation. Results: A total of 4544 patients were included across 173 centres in the UK and Ireland. The overall rate of AKI was 14·2 per cent (646 of 4544) and the 30-day mortality rate was 1·8 per cent (84 of 4544). Stage 1 AKI was significantly associated with 30-day mortality (unadjusted odds ratio 7·61, 95 per cent c.i. 4·49 to 12·90; P < 0·001), with increasing odds of death with each AKI stage. Six variables were selected for inclusion in the prognostic model: age, sex, ASA grade, preoperative estimated glomerular filtration rate, planned open surgery and preoperative use of either an angiotensin-converting enzyme inhibitor or an angiotensin receptor blocker. Internal validation demonstrated good model discrimination (c-statistic 0·65). Discussion: Following major gastrointestinal surgery, AKI occurred in one in seven patients. This preoperative prognostic model identified patients at high risk of postoperative AKI. Validation in an independent data set is required to ensure generalizability

    Mosquito ingestion of antibodies against mosquito midgut microbiota improves conversion of ookinetes to oocysts for Plasmodium falciparum, but not P. yoelii

    Get PDF
    The mosquito midgut is a site of complex interactions between the mosquito, the malaria parasite and the resident bacterial flora. In laboratory experiments, we observed significant enhancement of Plasmodium falciparum oocyst production when Anopheles gambiae (Diptera: Culicidae) mosquitoes were membrane-fed on infected blood containing gametocytes from in vitro cultures mixed with sera from rabbits immunized with A. gambiae midguts. To identify specific mechanisms, we evaluated whether the immune sera was interfering with the usual limiting activity of gram-negative bacteria in An. gambiae midguts. Enhancement of P. falciparum infection rates occurred at some stage between the ookinete and oocyst stage and was associated with greater numbers of oocysts in mosquitoes fed on immune sera. The same immune sera did not affect the sporogonic development of P. yoelii, a rodent malaria parasite. Not only did antibodies in the immune sera recognize several types of midgut-derived gram-negative bacteria (Pseudomonas spp. and Cedecea spp.), but gentamicin provided in the sugar meal 3. days before an infectious P. falciparum blood meal mixed with immune sera eliminated the enhancing effect. These results suggest that gram-negative bacteria, which normally impair P. falciparum development between the ookinete and oocyst stage, were altered by specific anti-bacterial antibodies produced by immunizing rabbits with non-antibiotic-treated midgut lysates. Because of the differences in developmental kinetics between human and rodent malaria species, the anti-bacterial antibodies had no effect on P. yoelii because their ookinetes leave the midgut much earlier than P. falciparum and so are not influenced as strongly by resident midgut bacteria. While this study highlights the complex interactions occurring between the parasite, mosquito, and midgut microbiota, the ultimate goal is to determine the influence of midgut microbiota on Plasmodium development in anopheline midguts in malaria endemic settings.Peer reviewedEntomology and Plant Patholog

    A 2-step synthesis of Combretastatin A-4 and derivatives as potent tubulin assembly inhibitors

    Get PDF
    A series of combretastatin derivatives were designed and synthesised by a two-step stereoselective synthesis by use of Wittig olefination followed by Suzuki cross-coupling. Interestingly, all new compounds (2a-2i) showed potent cell-based antiproliferative activities in nanomolar concentrations. Among the compounds, 2a, 2b and 2e were the most active across three cancer cell lines. In addition, these compounds inhibited the polymerisation of tubulin in vitro more efficiently than CA-4. They caused cell cycle arrest in G2/M phase further confirming their ability to inhibit tubulin polymerisation

    Does skin preparation alter suture strength characteristics? Assessing the effect of chlorhexidine and isopropyl alcohol on common skin closure suture material

    No full text
    Sutures are essential to approximate tissues and enable healing by first intention until a wound regains its original tensile strength. The mechanical properties of sutures are well documented, but the effects of exposing sutures to skin preparation solutions used in surgery are not. This study was performed to investigate whether 2% chlorhexidine and 70% isopropyl alcohol skin preparation, commonly used prior to incision and prior to closure, has any effect on the mechanical properties of several commonly used surgical suture types. Four suture types were soaked in either 2% chlorhexidine and 70% isopropyl alcohol or Hartmann's solution for 5 minutes. All sutures were left to dry for 11 days before being tested to failure using an Instron 3367 tensile testing machine. Testing revealed significant differences in failure load, ultimate tensile stress, and Young's modulus between suture types (P < .05). No significant differences in failure load (P = .98), ultimate tensile stress (P = .21), or Young's modulus (P = .22) were observed between the test group and the control group when comparing sutures of the same type. This study demonstrates that chlorhexidine/isopropyl skin preparation solutions do not significantly change the mechanical properties of suture materials exposed to them.published version, accepted version (12 month embargo), submitted versio
    corecore