Xeroderma pigmentosum genes and melanoma risk

Xeroderma pigmentosum is a rare autosomal recessive disease that is associated with a severe deficiency in nucleotide excision repair. The presence of a distinct the nucleotide excision repair (NER) mutation signature in melanoma suggests that perturbations in this critical repair process are likely to be involved with disease risk. We hypothesized that persons with polymorphic NER gene(s) are likely to have reduced NER activity and are consequently at an increased risk of melanoma development. We assessed the association between 94 SNPs within seven XP genes (XPA–XPG) and the melanoma risk in the Polish population. We genotyped 714 unselected melanoma patients and 1,841 healthy adults to determine if there were any polymorphisms differentially represented in the disease group. We found that a significantly decreased risk of melanoma was associated with the Xeroderma pigmentosum complementation (XPC) rs2228000_CT genotype (odds ratio [OR] = 0.15; p < 0.001) and the rs2228000_TT genotype (OR = 0.11; p < 0.001) compared to the reference genotype. Haplotype analysis within XPC revealed the rs2228001_A + G1475A_G + G2061A_A + rs2228000_T + rs3731062_C haplotype (OR = 0.26; p < 0.05) was associated with a significantly decreased disease risk. The haplotype analysis within the Xeroderma pigmentosum group D (XPD) showed a modest association between two haplotypes and a decrease in melanoma risk. There were no major differences between the prevalence of the XP polymorphisms among young or older patients with melanoma. Linkage disequilibrium of XPC: rs2228001, G1475A, G2061A, rs2228000 and rs3731062 was found. The data from our study support the notion that only XPC and XPD genes are associated with melanoma susceptibility.     

Median arcuate ligament syndrome: Predictor of ischemic complications?

Median arcuate ligament syndrome (MALS) is a pathologic entity that can affect the celiac axis. Due to the extensive collateral network of mesenteric circulation, stenosis of one mesenteric artery does not lead to significant symptoms. The purpose of this study was to describe multidetector computed tomography (MDCT) angiography findings of celiac artery entrapment by the median arcuate ligament and determine those patients with high risks of ischemic complications. From January 2012 to March 2016, 103 patients with celiac artery (CA) compression by median arcuate ligament were detected. In 23 patients collateral circulation was developed. In order to investigate the problem, we managed to estimate the correlation between range of stenosis of CA and presence of collateral circulation between the celiac artery (CA) and superior mesenteric artery (SMA). A statistically significant correlation was found between range of CA stenosis and collateral circulation presence (Spearman's correlation coefficient 0.339, P < 0.0001). In conclusions, based on our observations, we hypothesize that ischemia as a result of mesenteric vessel narrowing by the median arcuate ligament may occur more often than indicated by clinical symptoms and described in literature. Clin. Anat. 29:1025–1030, 2016. © 2016 Wiley Periodicals, Inc.     

Gentamicin affects melanogenesis in normal human melanocytes

Background: Aminoglycoside antibiotics, including gentamicin, despite their ability to induce adverse effects on pigmented tissues, remain valuable and sometimes indispensable for the treatment of various infections. It is known that gentamicin binds to melanin biopolymers, but the relation between this drug affinity to melanin and its toxicity is not well documented. The aim of this work was to examine the impact of gentamicin on viability and melanogenesis in HEMa-LP (light pigmented) and HEMn-DP (dark pigmented) normal human melanocytes.

Methodology/principal findings: The effect of gentamicin on cell viability was determined by 4-[3-(4-iodophenyl)-2-(4-nitrophenyl)-2H-5-tetrazolio]-1,3-benzene disulfonate (WST-1) assay; melanin content and tyrosinase activity were measured spectrophotometrically. It has been demonstrated that gentamicin induces concentration-dependent loss in melanocytes viability. The application of antibiotic in concentration of 10?mM causes higher reduction in viability of the light pigmented melanocytes (by about 74%) when compared with the dark pigmented ones (by about 62%). The value of the concentration of a drug that produces loss in cell viability by 50% (EC₅₀) for both cell lines was found to be ～7.5?mM. It has been shown that gentamicin causes inhibition of tyrosinase activity and reduces melanin content in light pigmented melanocytes significantly more than in the dark pigmented cells.

Conclusion/significance: We have found that gentamicin modulates melanization process in melanocytes in vitro, what may explain the potential role of melanin biopolymer in the mechanisms of undesirable toxic effects of this drug in vivo, as a result of its accumulation in pigmented tissues. We have also stated that the melanogenesis process in light pigmented melanocytes is more sensitive to the inhibitory effect of gentamicin than in the dark pigmented cells.     

Concurrent DNA Copy‐Number Alterations and Mutations in Genes Related to Maintenance of Genome Stability in Uninvolved Mammary Glandular Tissue from Breast Cancer Patients

Somatic mosaicism for DNA copy‐number alterations (SMC‐CNAs) is defined as gain or loss of chromosomal segments in somatic cells within a single organism. As cells harboring SMC‐CNAs can undergo clonal expansion, it has been proposed that SMC‐CNAs may contribute to the predisposition of these cells to genetic disease including cancer. Herein, the gross genomic alterations (>500 kbp) were characterized in uninvolved mammary glandular tissue from 59 breast cancer patients and matched samples of primary tumors and lymph node metastases. Array‐based comparative genomic hybridization showed 10% (6/59) of patients harbored one to 359 large SMC‐CNAs (mean: 1,328 kbp; median: 961 kbp) in a substantial portion of glandular tissue cells, distal from the primary tumor site. SMC‐CNAs were partially recurrent in tumors, albeit with considerable contribution of stochastic SMC‐CNAs indicating genomic destabilization. Targeted resequencing of 301 known predisposition and somatic driver loci revealed mutations and rare variants in genes related to maintenance of genomic integrity: BRCA1 (p.Gln1756Profs*74, p.Arg504Cys), BRCA2 (p.Asn3124Ile), NCOR1 (p.Pro1570Glnfs*45), PALB2 (p.Ser500Pro), and TP53 (p.Arg306*). Co‐occurrence of gross SMC‐CNAs along with point mutations or rare variants in genes responsible for safeguarding genomic integrity highlights the temporal and spatial neoplastic potential of uninvolved glandular tissue in breast cancer patients.     

Prevention of hospital infections by intervention and training (PROHIBIT): results of a pan-European cluster-randomized multicentre study to reduce central venous catheter-related bloodstream infections

Purpose

To test the effectiveness of a central venous catheter (CVC) insertion strategy and a hand hygiene (HH) improvement strategy to prevent central venous catheter-related bloodstream infections (CRBSI) in European intensive care units (ICUs), measuring both process and outcome indicators.

Methods

Adult ICUs from 14 hospitals in 11 European countries participated in this stepped-wedge cluster randomised controlled multicentre intervention study. After a 6 month baseline, three hospitals were randomised to one of three interventions every quarter: (1) CVC insertion strategy (CVCi); (2) HH promotion strategy (HHi); and (3) both interventions combined (COMBi). Primary outcome was prospective CRBSI incidence density. Secondary outcomes were a CVC insertion score and HH compliance.

Results

Overall 25,348 patients with 35,831 CVCs were included. CRBSI incidence density decreased from 2.4/1000 CVC-days at baseline to 0.9/1000 (p < 0.0001). When adjusted for patient and CVC characteristics all three interventions significantly reduced CRBSI incidence density. When additionally adjusted for the baseline decreasing trend, the HHi and COMBi arms were still effective. CVC insertion scores and HH compliance increased significantly with all three interventions.

Conclusions

This study demonstrates that multimodal prevention strategies aiming at improving CVC insertion practice and HH reduce CRBSI in diverse European ICUs. Compliance explained CRBSI reduction and future quality improvement studies should encourage measuring process indicators.

     

The trans/cis photoisomerization in hydrogen bonded complexes with stability controlled by substituent effects: 3-(6-aminopyridin-3-yl)acrylate case study

The association of aminopyridine-based acrylic acid and its salt was studied by NMR titration experiments. The AA (acceptor, acceptor) hydrogen-bonding pattern present in the salt forms a complex readily with a DD (donor, donor) hydrogen-bonding pattern of the substituted ureas even in polar and competitive environment. The double carbon–carbon bond in the acrylic acid derivative is subjected to photoisomerization. This is dependent on the association with substituted urea derivatives. The substituent in ureas influences the trans/cis isomerization kinetics and position of the photostationary state. Two mechanisms that influence the photoisomerization were proposed. To the best of our knowledge, the trans/cis photoisomerization influenced by the substituent in such a hydrogen-bonding pattern has not observed previously. It was shown that interaction with urea derivatives causes lowering of the trans-to-cis photoreaction rates.

The association of aminopyridine-based acrylic acid and its salt was studied by NMR titration experiments.     

Anthracycline-induced cardiotoxicity and renin-angiotensin-aldosterone system—from molecular mechanisms to therapeutic applications

Heart Failure Reviews - Few millions of new cancer cases are diagnosed worldwide every year. Due to significant progress in understanding cancer biology and developing new therapies, the mortality...