The ancestral haplotype markers HLA -A3 and B7 do not influence the likelihood of advanced hepatic fibrosis or cirrhosis in HFE hemochromatosis.

Advanced hepatic fibrosis occurs in up to 25% of individuals with C282Y homozygous hemochromatosis. Our aim was to determine whether human leukocyte antigen (HLA)-A3 and B7 alleles act as genetic modifiers of the likelihood of advanced hepatic fibrosis. Between 1972 and 2013, 133 HFE C282Y homozygous individuals underwent clinical and biochemical evaluation, HLA typing, liver biopsy for fibrosis staging and phlebotomy treatment. Hepatic fibrosis was graded according to Scheuer as F0-2 (low grade hepatic fibrosis), F3-4 (advanced hepatic fibrosis), and F4 cirrhosis. We analysed associations between the severity of fibrosis and HLA-A3 homozygosity, heterozygosity or absence, with or without the presence of HLA-B7 using categorical analysis. The mean age of HLA-A3 homozygotes (n = 24), heterozygotes (n = 65) and HLA-A3 null individuals (n = 44) was 40 years. There were no significant differences between the groups for mean(± SEM) serum ferritin levels (1320 ± 296, 1217 ± 124, 1348 ± 188 [Formula: see text]g/L), hepatic iron concentration (178 ± 26, 213 ± 22, 199 ± 29 [Formula: see text]mol/g), mobilizable iron stores (9.9 ± 1.5, 9.5 ± 1.5, 11.5 ± 1.7 g iron removed via phlebotomy), frequency of advanced hepatic fibrosis (5/24[12%], 13/63[19%], 10/42[19%]) or cirrhosis (3/24[21%], 12/63[21%], 4/42[24%]), respectively. The presence or absence of HLA-B7 did not influence the outcome. Thus, HLA-A3 and HLA-B7 alleles are not associated with the risk of advanced hepatic fibrosis or cirrhosis in C282Y hemochromatosis.

Is the use of a routine intraoperative cholangiogram necessary in laparoscopic cholecystectomy?

INTRODUCTION: Although laparoscopic cholecystectomy (LC) has been standard of care for symptomatic gallstone disease for almost 30 years, the use of routine intraoperative cholangiogram (IOC) remains controversial. There are marked variations in the use IOC during LC internationally. Debate has continued about its benefit, in part because of inconsistent benefit, time, and resources required to complete IOC. This literature review is presented as a debate to outline the arguments in favour of and against routine IOC in laparoscopic cholecystectomy. METHODS: A standard literature review of PubMed, Medline, OVID, EMBASE, CINHIL and Web of Science was performed, specifically for literature pertaining to the use of IOC or alternative intra-operative methods for imaging the biliary tree in LC. Two authors assembled the evidence in favour, and two authors assembled the evidence against. RESULTS: From this controversies piece we found that there is little discernible change in the number of BDIs requiring repair procedures. Although IOC is associated with a small absolute reduction in bile duct injury, there are other confounding factors, including a change in laparoscopic learning curves. Alternative technologies such as intra-operative ultrasound, indocyanine green imaging, and increased access to ERCP may contribute to a reduction in the need for routine IOC. CONCLUSIONS: In spite of 30 years of accumulating evidence, routine IOC remains controversial. As technology advances, it is likely that alternative methods of imaging and accessing the bile duct will supplant routine IOC.

Design, synthesis and evaluation of tryptophan analogues as tool compounds to study IDO1 activity.

The metabolism of l-tryptophan to N-formyl-l-kynurenine by indoleamine-2,3-dioxygenase 1 (IDO1) is thought to play a critical role in tumour-mediated immune suppression. Whilst there has been significant progress in elucidating the overall enzymatic mechanism of IDO1 and related enzymes, key aspects of the catalytic cycle remain poorly understood. Here we report the design, synthesis and biological evaluation of a series of tryptophan analogues which have the potential to intercept putative intermediates in the metabolism of 1 by IDO1. Functionally-relevant binding to IDO1 was demonstrated through enzymatic inhibition, however no IDO1-mediated metabolism of these compounds was observed. Subsequent T m-shift analysis shows the most active compound, 17, exhibits a distinct profile from known competitive IDO1 inhibitors, with docking studies supporting the hypothesis that 17 may bind at the recently-discovered Si site. These findings provide a start-point for development of further mechanistic probes and more potent tryptophan-based IDO1 inhibitors.

Cwc21p promotes the second step conformation of the spliceosome and modulates 3' splice site selection.

Pre-mRNA splicing involves two transesterification steps catalyzed by the spliceosome. How RNA substrates are positioned in each step and the molecular rearrangements involved, remain obscure. Here, we show that mutations in PRP16, PRP8, SNU114 and the U5 snRNA that affect this process interact genetically with CWC21, that encodes the yeast orthologue of the human SR protein, SRm300/SRRM2. Our microarray analysis shows changes in 3' splice site selection at elevated temperature in a subset of introns in cwc21Δ cells. Considering all the available data, we propose a role for Cwc21p positioning the 3' splice site at the transition to the second step conformation of the spliceosome, mediated through its interactions with the U5 snRNP. This suggests a mechanism whereby SRm300/SRRM2, might influence splice site selection in human cells.

Prp8p dissection reveals domain structure and protein interaction sites.

We describe a novel approach to characterize the functional domains of a protein in vivo. This involves the use of a custom-built Tn5-based transposon that causes the expression of a target gene as two contiguous polypeptides. When used as a genetic screen to dissect the budding yeast PRP8 gene, this showed that Prp8 protein could be dissected into three distinct pairs of functional polypeptides. Thus, four functional domains can be defined in the 2413-residue Prp8 protein, with boundaries in the regions of amino acids 394-443, 770, and 2170-2179. The central region of the protein was resistant to dissection by this approach, suggesting that it represents one large functional unit. The dissected constructs allowed investigation of factors that associate strongly with the N- or the C-terminal Prp8 protein fragments. Thus, the U5 snRNP protein Snu114p associates with Prp8p in the region 437-770, whereas fragmenting Prp8p at residue 2173 destabilizes its association with Aar2p.

Highly diastereoselective 1,3-dipolar cycloaddition reactions of trans-2-methylene-1,3-dithiolane 1,3-dioxide with 3-oxidopyridinium and 3-oxidopyrylium betaines: a route to the tropane skeleton.

The C2-symmetric vinyl sulfoxide, trans-2-methylene-1,3-dithiolane 1,3-dioxide, was found to react with a range of 3-oxidopyridinium betaines (bearing different substituents on nitrogen) in high yield and with total diastereoselectivity. A 2.3:1 mixture of regioisomers was formed with all of the 3-oxidopyridinium betaines but the ratio was found to change over prolonged periods of time due to reversibility of the minor regioisomer. 3-Oxidopyridinium betaines bearing methyl substituents at either the 2- or 6-position were also tested in the cycloaddition process. Improved regioselectivity (8:1) and again high diastereoselectivity were observed with the betaine having an additional substituent at the 2-position, but with betaines having a substituent in the 6-position although high regioselectivity was observed (9.9:1), the major isomer was formed with low diastereoselectivity (5.5:4.4). The origin of the regio- and diastereo-selectivity with all the betaines is discussed. Finally, the C2-symmetric vinyl sulfoxide, trans-2-methylene-1,3-dithiolane 1,3-dioxide was reacted with an oxidopyrylium betaine in moderate yield. Good regioselectivity and moderate diastereoselectivity were observed.