The Impact of Graphene and Diatomite Admixtures on the Performance and Properties of High-Performance Magnesium Oxychloride Cement Composites

A high-performance magnesium oxychloride cement (MOC) composite composed of silica sand, diatomite powder, and doped with graphene nanoplatelets was prepared and characterized. Diatomite was used as a 10 vol.% replacement for silica sand. The dosage of graphene was 0.5 wt.% of the sum of the MgO and MgCl₂·6H₂O masses. The broad product characterization included high-resolution transmission electron microscopy, X-ray diffraction, X-ray fluorescence, scanning electron microscopy and energy dispersive spectroscopy analyses. The macrostructural parameters, pore size distribution, mechanical resistance, stiffness, hygric and thermal parameters of the composites matured for 28-days were also the subject of investigation. The combination of diatomite and graphene nanoplatelets greatly reduced the porosity and average pore size in comparison with the reference material composed of MOC and silica sand. In the developed composites, well stable and mechanically resistant phase 5 was the only precipitated compound. Therefore, the developed composite shows high compactness, strength, and low water imbibition which ensure high application potential of this novel type of material in the construction industry.     

Mutation Screening of the HGD Gene Identifies a Novel Alkaptonuria Mutation with Significant Founder Effect and High Prevalence

Alkaptonuria (AKU) is an autosomal recessive disorder; caused by the mutations in the homogentisate 1, 2‐dioxygenase (HGD) gene located on Chromosome 3q13.33. AKU is a rare disorder with an incidence of 1: 250,000 to 1: 1,000,000, but Slovakia and the Dominican Republic have a relatively higher incidence of 1: 19,000. Our study focused on studying the frequency of AKU and identification of HGD gene mutations in nomads. HGD gene sequencing was used to identify the mutations in alkaptonurics. For the past four years, from subjects suspected to be clinically affected, we found 16 positive cases among a randomly selected cohort of 41 Indian nomads (Narikuravar) settled in the specific area of Tamil Nadu, India. HGD gene mutation analysis showed that 11 of these patients carry the same homozygous splicing mutation c.87 + 1G > A; in five cases, this mutation was found to be heterozygous, while the second AKU‐causing mutation was not identified in these patients. This result indicates that the founder effect and high degree of consanguineous marriages have contributed to AKU among nomads. Eleven positive samples were homozygous for a novel mutation c.87 + 1G > A, that abolishes an intron 2 donor splice site and most likely causes skipping of exon 2. The prevalence of AKU observed earlier seems to be highly increased in people of nomadic origin.     

Controversial association results for INSIG2 on body mass index may be explained by interactions with age and with MC4R

Among the single-nucleotide polymorphisms (SNPs) previously reported to be associated with body mass index (BMI) and obesity, we focus on a common risk variant rs7566605 upstream of the insulin-induced gene 2 (INSIG2) gene and a rare protective variant rs2229616 on the melanocortin-4 receptor (MC4R) gene. INSIG2 is involved in adipogenesis and MC4R effects hormonal appetite control in response to the amount of adipose tissue. The influence of rs2229616 (MC4R) on BMI and obesity has been confirmed repeatedly and insight into the underlying mechanism provided. However, a main effect of rs7566605 (INSIG2) is under debate because of inconsistent replications of association. Interaction of rs7566605 with age may offer an explanation. SNP–age and SNP–SNP interaction models were tested on independent individuals from three population-based longitudinal cohorts, restricting the analysis to an observed age of 25–74 years. KORA S3/F3, KORA S4/F4 (Augsburg, Germany, 1994–2005, 1999–2008), and Framingham-Offspring data (Framingham, USA, 1971–2001) were analysed, with a total sample size of N=6926 in the joint analysis. The effect of interaction between rs7566605 and age on BMI and obesity status is significant and consistent across studies. This new evidence for rs7566605 (INSIG2) complements previous research. In addition, the interaction effect of rs7566605 with the MC4R variant rs2229616 on BMI was observed. This effect size was three times larger than that in a previously reported single-locus main effect of rs2229616. This leads to the conclusion that SNP–age or SNP–SNP interactions can mask genetic effects for complex diseases if left unaccounted for.     

Identification of new urinary gamma‐hydroxybutyric acid markers applying untargeted metabolomics analysis following placebo‐controlled administration to humans

Gamma‐hydroxybutyrate (GHB) is a short‐chain fatty acid that occurs naturally in the mammalian brain and is prescribed as a medication against narcolepsy or used as a drug of abuse. Particularly, its use as a knock‐out drug in cases of drug‐facilitated crimes is of major importance in forensic toxicology. Because of its rapid metabolism and resulting narrow detection windows (<12 hours in urine), detection of GHB remains challenging. Thus, there is an urgent call for new markers to improve the reliable detection of GHB use. In the framework of a randomized, placebo‐controlled, crossover study in 20 healthy male volunteers, urine samples obtained 4.5 hours post‐administration were submitted to untargeted mass spectrometry [MS, quadrupole time of flight (QTOF)] analysis to identify possible new markers of GHB intake. MS data from four different analytical methods (reversed phase and hydrophilic interaction liquid chromatography; positive and negative electrospray ionization) were filtered for significantly changed features applying univariate and multivariate statistics. From the resulting 42 compounds of interest, 8 were finally identified including conjugates of GHB with carnitine, glutamate, and glycine as well as the endogenous compounds glycolate and succinylcarnitine. While GHB conjugates were only detectable in the GHB, but not in the placebo group, glycolate and succinylcarnitine were present in both groups albeit significantly increased through GHB intake. Untargeted metabolomics proved as a suitable tool for the non‐hypothesis driven identification of new GHB markers. However, more studies on actual concentrations, detection windows, and stability will be necessary to assess the suitability of these markers for routine application.     

Arachidyl amido cholanoic acid improves liver glucose and lipid homeostasis in nonalcoholic steatohepatitis via AMPK and mTOR regulation

BACKGROUND Arachidyl amido cholanoic acid(Aramchol) is a potent downregulator of hepatic stearoyl-CoA desaturase 1(SCD1) protein expression that reduces liver triglycerides and fibrosis in animal models of steatohepatitis. In a phase IIb clinical trial in patients with nonalcoholic steatohepatitis(NASH), 52 wk of treatment with Aramchol reduced blood levels of glycated hemoglobin A1c, an indicator of glycemic control.AIM To assess lipid and glucose metabolism in mouse hepatocytes and in a NASH mouse model [induced with a 0.1% methionine and choline deficient diet(0.1 MCD)] after treatment with Aramchol.METHODS Isolated primary mouse hepatocytes were incubated with 20 μmol/L Aramchol or vehicle for 48 h. Subsequently, analyses were performed including Western blot, proteomics by mass spectrometry, and fluxomic analysis with ~(13)C-uniformly labeled glucose. For the in vivo part of the study, male C57 BL/6 J mice were randomly fed a control or 0.1 MCD for 4 wk and received 1 or 5 mg/kg/d Aramchol or vehicle by intragastric gavage for the last 2 wk. Liver metabolomics were assessed using ultra-high-performance liquid chromatography-time of flight-MS for the determination of glucose metabolism-related metabolites.RESULTS Combination of proteomics and Western blot analyses showed increased AMPK activity while the activity of nutrient sensor mTORC1 was decreased by Aramchol in hepatocytes. This translated into changes in the content of their downstream targets including proteins involved in fatty acid(FA) synthesis and oxidation [PACCα/β(S79), SCD1, CPT1A/B, HADHA, and HADHB], oxidative phosphorylation(NDUFA9, NDUFB11, NDUFS1, NDUFV1, ETFDH, and UQCRC2), tricarboxylic acid(TCA) cycle(MDH2, SUCLA2, and SUCLG2), and ribosome(P-p70S6K[T389] and P-S6[S235/S236]). Flux experiments with ~(13)C uniformely labeled glucose showed that TCA cycle cataplerosis was reduced by Aramchol in hepatocytes, as indicated by the increase in the number of rounds that malate remained in the TCA cycle. Finally, liver metabolomic analysis showed that glucose homeostasis was improved by Aramchol in 0.1 MCD fed mice in a dose-dependent manner, showing normalization of glucose, G6P, F6P, UDP-glucose, and Rbl5 P/Xyl5 P.CONCLUSION Aramchol exerts its effect on glucose and lipid metabolism in NASH through activation of AMPK and inhibition of mTORC1, which in turn activate FA β-oxidation and oxidative phosphorylation.     

Iron status in patients with pyruvate kinase deficiency: neonatal hyperferritinaemia associated with a novel frameshift deletion in the PKLR gene (p.Arg518fs), and low hepcidin to ferritin ratios

Pyruvate kinase (PK) deficiency is an iron‐loading anaemia characterized by chronic haemolysis, ineffective erythropoiesis and a requirement for blood transfusion in most cases. We studied 11 patients from 10 unrelated families and found nine different disease‐causing PKLR mutations. Two of these mutations ‐ the point mutation c.878A>T (p.Asp293Val) and the frameshift deletion c.1553delG (p.(Arg518Leufs*12)) ‐ have not been previously described in the literature. This frameshift deletion was associated with an unusually severe phenotype involving neonatal hyperferritinaemia that is not typical of PK deficiency. No disease‐causing mutations in genes associated with haemochromatosis could be found. Inappropriately low levels of hepcidin with respect to iron loading were detected in all PK‐deficient patients with increased ferritin, confirming the predominant effect of accelerated erythropoiesis on hepcidin production. Although the levels of a putative hepcidin suppressor, growth differentiation factor‐15, were increased in PK‐deficient patients, no negative correlation with hepcidin was found. This result indicates the existence of another as‐yet unidentified erythroid regulator of hepcidin synthesis in PK deficiency.     

De novo mutations of GCK,HNF1A and HNF4A may be more frequent in MODY than previously assumed

Aims/hypothesis

MODY is mainly characterised by an early onset of diabetes and a positive family history of diabetes with an autosomal dominant mode of inheritance. However, de novo mutations have been reported anecdotally. The aim of this study was to systematically revisit a large collection of MODY patients to determine the minimum prevalence of de novo mutations in the most prevalent MODY genes (i.e. GCK, HNF1A, HNF4A).

Methods

Analysis of 922 patients from two national MODY centres (Slovakia and the Czech Republic) identified 150 probands (16%) who came from pedigrees that did not fulfil the criterion of two generations with diabetes but did fulfil the remaining criteria. The GCK, HNF1A and HNF4A genes were analysed by direct sequencing.

Results

Mutations in GCK, HNF1A or HNF4A genes were detected in 58 of 150 individuals. Parents of 28 probands were unavailable for further analysis, and in 19 probands the mutation was inherited from an asymptomatic parent. In 11 probands the mutations arose de novo.

Conclusions/interpretation

In our cohort of MODY patients from two national centres the de novo mutations in GCK, HNF1A and HNF4A were present in 7.3% of the 150 families without a history of diabetes and 1.2% of all of the referrals for MODY testing. This is the largest collection of de novo MODY mutations to date, and our findings indicate a much higher frequency of de novo mutations than previously assumed. Therefore, genetic testing of MODY could be considered for carefully selected individuals without a family history of diabetes.