16 research outputs found

    High-resolution dietary reconstruction of victims of the 79 CE Vesuvius eruption at Herculaneum by compound-specific isotope analysis.

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    The remains of those who perished at Herculaneum in 79 CE offer a unique opportunity to examine lifeways across an ancient community who lived and died together. Historical sources often allude to differential access to foodstuffs across Roman society but provide no direct or quantitative information. By determining the stable isotope values of amino acids from bone collagen and deploying Bayesian models that incorporate knowledge of protein synthesis, we were able to reconstruct the diets of 17 adults from Herculaneum with unprecedented resolution. Significant differences in the proportions of marine and terrestrial foods consumed were observed between males and females, implying that access to food was differentiated according to gender. The approach also provided dietary data of sufficient precision for comparison with assessments of food supply to modern populations, opening up the possibility of benchmarking ancient diets against contemporary settings where the consequences for health are better understood

    The impact of immediate breast reconstruction on the time to delivery of adjuvant therapy: the iBRA-2 study

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    Background: Immediate breast reconstruction (IBR) is routinely offered to improve quality-of-life for women requiring mastectomy, but there are concerns that more complex surgery may delay adjuvant oncological treatments and compromise long-term outcomes. High-quality evidence is lacking. The iBRA-2 study aimed to investigate the impact of IBR on time to adjuvant therapy. Methods: Consecutive women undergoing mastectomy ± IBR for breast cancer July–December, 2016 were included. Patient demographics, operative, oncological and complication data were collected. Time from last definitive cancer surgery to first adjuvant treatment for patients undergoing mastectomy ± IBR were compared and risk factors associated with delays explored. Results: A total of 2540 patients were recruited from 76 centres; 1008 (39.7%) underwent IBR (implant-only [n = 675, 26.6%]; pedicled flaps [n = 105,4.1%] and free-flaps [n = 228, 8.9%]). Complications requiring re-admission or re-operation were significantly more common in patients undergoing IBR than those receiving mastectomy. Adjuvant chemotherapy or radiotherapy was required by 1235 (48.6%) patients. No clinically significant differences were seen in time to adjuvant therapy between patient groups but major complications irrespective of surgery received were significantly associated with treatment delays. Conclusions: IBR does not result in clinically significant delays to adjuvant therapy, but post-operative complications are associated with treatment delays. Strategies to minimise complications, including careful patient selection, are required to improve outcomes for patients

    Direct Carbon-Carbon Bond Formation via Base Mediated and Reductive Soft Enolization of Thioesters, the First Asymmetric Total Synthesis of (+)- and (-)-Clusianone, and Progress Toward the Asymmetric Total Synthesis of Brasilicardin A

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    <p>Three methodology studies and two total synthesis endeavors are presented. First, a study of Lewis acid and hydrogen bond mediated soft enolization of thioesters and their addition to imines in the Mannich reaction is reported. MgBr2*OEt2 and Hunig's base are used in concert with bulky thioesters and aromatic aldehydes to generate syn-b-aminothioesters with moderate diastereoselectivity and yield. Next, a biomimetic organocatalytic Mannich reaction is presented using a chiral cinchona alkaloid to effect the enantioselective addition of an imines to thioesters with high yield and diastereoselectivity and enantioselectivities up to 88:12.</p><p>The direct addition of enolizable aldehydes to a-iodo thioesters to produce b-hydroxy thioesters enabled by reductive soft enolization is reported. The transformation is operationally simple and efficient and has the unusual feature of giving high syn-selectivity, which is the opposite of that produced in the aldol addition with (thio)esters under conventional conditions. This method is tolerant to aldehydes and imines that contain acidic a-protons, as well as electrophiles containing other acidic protons and base-sensitive functional groups.</p><p>The development of a strategy for the asymmetric synthesis of a large portion of the polycyclic polyprenylated acyl phloroglucinols via N-amino cyclic carbamate hydrazones, and its application to the first asymmetric total synthesis of both (+)- and (-)-clusianone is discussed. The clusianones are synthesized with an er of 99:1 and their anti-HIV activity is found to be 1.53 and 1.13 &#61549;M, respectively. A library of clusianone-like compounds is synthesized and their biological activity has been probed.</p><p>Finally, efforts towards the total synthesis of brasilicardin A are reported. An appropriate model system was synthesized, and conditions were established using a pinene-based aldol reaction to synthesize the b-methoxy-a-amino ester side chain of the molecule. Next, efforts toward the synthesis of the anti-syn-anti- perhydro-phenanthrene core are discussed.</p>Dissertatio

    Short Enantioselective Total Syntheses of Cheloviolenes A and B and Dendrillolide C via Convergent Fragment Coupling Using a Tertiary Carbon Radical

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    The development of a convergent fragment coupling strategy for the enantioselective total syntheses of a group of rearranged spongian diterpenoids that harbor the cis-2,8-dioxabicyclo[3.3.0]octan-3-one unit is described. The key bond disconnection relies on a late-stage fragment coupling between a tertiary carbon radical and an electron-deficient alkene to unite two ring systems and form two new stereocenters, one of which is quaternary, in a stereoselective and efficient manner. This strategy is applied toward scalable 14-15 step syntheses of three rearranged spongian diterpenoids, cheloviolenes A and B, and dendrillolide C.11Nsciescopu

    Structural basis of lipid-droplet localization of 17-beta-hydroxysteroid dehydrogenase 13

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    Abstract Hydroxysteroid 17-beta-dehydrogenase 13 (HSD17B13) is a hepatic lipid droplet-associated enzyme that is upregulated in patients with non-alcoholic fatty liver disease. Recently, there have been several reports that predicted loss of function variants in HSD17B13 protect against the progression of steatosis to non-alcoholic steatohepatitis with fibrosis and hepatocellular carcinoma. Here we report crystal structures of full length HSD17B13 in complex with its NAD+ cofactor, and with lipid/detergent molecules and small molecule inhibitors from two distinct series in the ligand binding pocket. These structures provide insights into a mechanism for lipid droplet-associated proteins anchoring to membranes as well as a basis for HSD17B13 variants disrupting function. Two series of inhibitors interact with the active site residues and the bound cofactor similarly, yet they occupy different paths leading to the active site. These structures provide ideas for structure-based design of inhibitors that may be used in the treatment of liver disease
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