Metabolic profile of patients with isolated systolic hypertension.

PURPOSE/OBJECTIVE: While hypertension is an important contributor to cardiovascular disease (CVD) and its treatment has well-established mortality benefits, there is uncertainty as regards the management of isolated systolic hypertension (ISH). Furthermore, the association of ISH with CVD and mortality has been established, but the metabolic characteristics of the affected population have not as yet been adequately described. The aim of this study was to describe the metabolic profiles of patients with ISH. METHODS: An observational study of patients attending the Hypertension Unit of the University Hospital of Heraklion, Crete, Greece, was performed. RESULTS: In total, 809 hypertensive patients not on any antihypertensive treatment were identified. Among them, 44.7% were men, aged 55.6 ± 12.5 years, while 29.7% of both men and women were smokers. Systolic blood pressure was 161.3 ± 15.8 mmHg and diastolic blood pressure was 96.1 ± 11.3 mmHg. Body mass index (BMI) was 31 ± 5.3 kg/m2, while 9.6% had type 2 diabetes (T2D). A comparison of patients with ISH with those with hypertension, but not ISH, revealed that patients with ISH were older and had lower SBP and higher pulse pressure, while they also had lower total cholesterol and LDL and were more likely to have T2D, albeit they had a slightly lower BMI. On the other hand, they did not have any difference in terms of gender, smoking status, HDL, triglycerides, liver biochemistry, uric acid, or prevalence of impaired fasting glucose. CONCLUSION: Patients with ISH were older, with lower SBP, total cholesterol, and LDL and higher pulse pressure and higher prevalence of diabetes.

A case of severe hyponatremia due to linezolid-induced SIADH.

WHAT IS KNOWN AND OBJECTIVE: Hyponatremia is the most common electrolyte disorder. Syndrome of inappropriate antidiuretic hormone secretion (SIADH) is the main cause of euvolemic hyponatremia and is often associated with medications or underlying diseases. Linezolid is a potent antibiotic against resistant Gram-positive microorganisms that has been associated with mild hyponatremia, yet with a mechanism different from SIADH. CASE SUMMARY: We present the case of a patient who developed severe hyponatremia during treatment with linezolid for an ampicillin-resistant E. faecium bacteremia. A thorough work-up during the hyponatremia, as well as after it resolved, firmly identified SIADH as its cause. Importantly, SIADH occurred after linezolid was started and resolved after it was stopped, and a work-up for another cause of SIADH was negative, suggesting that linezolid was the cause of SIADH in this patient. WHAT IS NEW AND CONCLUSION: This is the second case of a linezolid-induced SIADH, diagnosed with a thorough work-up so to correctly differentiate between SIADH from other causes of hyponatremia.

Gram-negative bacteria as emerging pathogens affecting mortality in skin and soft tissue infections.

INTRODUCTION: Skin and soft tissue infections (SSTIs) are commonly encountered in clinical practice and mainly caused by gram-positive cocci such as S.aureus and ß-hemolytic streptococci. Complicated SSTIs involving deeper tissues often necessitate surgical intervention and occur in patients with significant comorbidities such as diabetes or immunocompromising conditions. METHODS: In this study, we retrospectively reviewed the epidemiology, clinical characteristics, microbiology, and treatment of patients admitted with SSTI during a five-year period in the Internal Medicine Department of a tertiary hospital. RESULTS: During the study period, 317 patients were recorded, with a mean age of 72.1 years. The most common underlying medical conditions were diabetes mellitus, chronic kidney disease, and heart failure. Cultures were positive in 23.3 % of cases, 62.2 % of which were polymicrobial. The most frequently isolated microorganisms were Enterococci, Escherichia coli, and Pseudomonas aeruginosa. Significant antimicrobial resistance rates were noted, in particular for gram-negative microorganisms. Mortality was higher than described in the literature and associated with age, comorbidities, and infection by gram-negative microorganisms. CONCLUSION: This study denotes the role of gram-negative bacteria in SSTI epidemiology. Therapeutic protocols regarding the empiric treatment of SSTIs should necessarily take into account the local epidemiology of isolated pathogens and antimicrobial resistance. HIPPOKRATIA 2018, 22(1): 23-28.

Frequent COL4 mutations in familial microhematuria accompanied by later-onset Alport nephropathy due to focal segmental glomerulosclerosis.

Familial microscopic hematuria (FMH) is associated with a genetically heterogeneous group of conditions including the collagen-IV nephropathies, the heritable C3/CFHR5 nephropathy and the glomerulopathy with fibronectin deposits. The clinical course varies widely, ranging from isolated benign familial hematuria to end-stage renal disease (ESRD) later in life. We investigated 24 families using next generation sequencing (NGS) for 5 genes: COL4A3, COL4A4, COL4A5, CFHR5 and FN1. In 17 families (71%), we found 15 pathogenic mutations in COL4A3/A4/A5, 9 of them novel. In 5 families patients inherited classical AS with hemizygous X-linked COL4A5 mutations. Even more patients developed later-onset Alport-related nephropathy having inherited heterozygous COL4A3/A4 mutations that cause thin basement membranes. Amongst 62 heterozygous or hemizygous patients, 8 (13%) reached ESRD, while 25% of patients with heterozygous COL4A3/A4 mutations, aged >50-years, reached ESRD. In conclusion, COL4A mutations comprise a frequent cause of FMH. Heterozygous COL4A3/A4 mutations predispose to renal function impairment, supporting that thin basement membrane nephropathy is not always benign. The molecular diagnosis is essential for differentiating the X-linked from the autosomal recessive and dominant inheritance. Finally, NGS technology is established as the gold standard for the diagnosis of FMH and associated collagen-IV glomerulopathies, frequently averting the need for invasive renal biopsies.

A statistical state dynamics approach to wall turbulence.

This paper reviews results obtained using statistical state dynamics (SSD) that demonstrate the benefits of adopting this perspective for understanding turbulence in wall-bounded shear flows. The SSD approach used in this work employs a second-order closure that retains only the interaction between the streamwise mean flow and the streamwise mean perturbation covariance. This closure restricts nonlinearity in the SSD to that explicitly retained in the streamwise constant mean flow together with nonlinear interactions between the mean flow and the perturbation covariance. This dynamical restriction, in which explicit perturbation-perturbation nonlinearity is removed from the perturbation equation, results in a simplified dynamics referred to as the restricted nonlinear (RNL) dynamics. RNL systems, in which a finite ensemble of realizations of the perturbation equation share the same mean flow, provide tractable approximations to the SSD, which is equivalent to an infinite ensemble RNL system. This infinite ensemble system, referred to as the stochastic structural stability theory system, introduces new analysis tools for studying turbulence. RNL systems provide computationally efficient means to approximate the SSD and produce self-sustaining turbulence exhibiting qualitative features similar to those observed in direct numerical simulations despite greatly simplified dynamics. The results presented show that RNL turbulence can be supported by as few as a single streamwise varying component interacting with the streamwise constant mean flow and that judicious selection of this truncated support or 'band-limiting' can be used to improve quantitative accuracy of RNL turbulence. These results suggest that the SSD approach provides new analytical and computational tools that allow new insights into wall turbulence.This article is part of the themed issue 'Toward the development of high-fidelity models of wall turbulence at large Reynolds number'.

Alphoid DNA from different chromosomes forms de novo minichromosomes with high efficiency.

Clones from one BAC and one PAC library carrying centromeric alphoid DNA were characterized and found to be stable but to differ according to the enzyme used to make the library. Five different clones with homogeneous alphoid DNA, derived from chromosomes 13/21, 14/22, 17 and 18, were all shown to form minichromosomes de novo after transfection into the human cell line HT1080 in greater than 29% of the cell lines analysed. Similarly sized alphoid arrays (110-160 kb) from chromosomes 17, 13/21 and 14/22 all formed minichromosomes in about 50% of the cell lines analysed while a smaller array (50 kb) of 14/22 alphoid was less efficient (29% of cell lines) and a larger array (200 kb) from chromosome 18 was more efficient (2/2 cell lines). Thus the larger arrays of alphoid DNA gave higher percentages of cell lines with minichromosomes. However, smaller arrays may be preferable for gene expression as there appeared to be more EGFP expression from these minichromosomes.

Physical stability of sonicated arsonoliposomes: effect of calcium ions.

The physical stability of sonicated arsonoliposomes in the absence and presence of Ca(2+) ions is evaluated. Cholesterol-containing arsonoliposomes composed of arsonolipids [having different acyl chains (C(12)-C(18))], or mixtures of arsonolipids with phospholipids (phosphatidylcholine or distearoyl-phosphatidylcholine) were prepared, and physical stability was evaluated in the absence and presence of CaCl(2), by vesicle dispersions turbidity measurements and cryo-electron microscopy morphological assessment. In some cases, vesicle zeta-potential was measured, under identical conditions. Results demonstrate that self-aggregation of the vesicles studied is low and influenced by the acyl chain length of the arsonolipid used, whereas calcium-induced aggregation is higher, correlating well with the decreased values of vesicle zeta-potential in the presence of Ca(2+) ions (weaker electrostatic repulsion). Acyl chain length of arsonolipids used has a significant quantitative effect on Ca(2+)-induced vesicle aggregation mainly for arsonoliposomes that contain phospholipids (mixed), compared with the vesicles that consist of plain arsonolipids (significant effect only for initial aggregation at time 0). Another difference between plain and mixed arsonoliposomes is that for mixed arsonoliposomes Ca(2+)-induced increases in turbidity are irreversible by ethylenediaminotetraacetic acid, suggesting that vesicle fusion is taking place. This was confirmed by cryo-electron microscopy observations. Finally, when phosphatidylcholine is replaced by distearoyl-phosphatidylcholine, arsonoliposomes are more stable in terms of self-aggregation, but in the presence of calcium, the turbidity and morphology results are similar.

The effect of pH on the electrophoretic behaviour of a new class of liposomes: arsonoliposomes.

Herein we report the effect of pH on the surface charge of a new class of liposomes: arsonoliposomes. Plain or mixed arsonoliposomes with cholesterol (Chol) and distearoyl-phosphatidylcholine (DSPC) in 1:1 molar ratio were prepared with lauryl-(C12), myristoyl-(C14) and palmitoyl-(C16) acyl side chain arsonolipids. The one step hydration method was used for vesicle preparation and zeta potential measurements were performed in the pH range from 3 to 9. The results revealed that these lipids hold a negative surface charge at all pH values investigated. The presence of cholesterol in 1:1 molar ratio results in higher zeta potential compared with plain arsonoliposomes with the exception of palmitoyl-(C16) acyl chain arsonolipids in neutral and slightly basic pH values. Oppositely, the DSPC (1:1 molar ratio) containing arsonoliposomes had lower values of zeta potential compared with plain arsonoliposomes. Concluding, the experimental results reveal that zeta potential of arsonoliposomes is indeed modified when the vesicles are incubated in environments with different acidity. In most cases these changes are in accordance with the ionization pattern of the arsonolipid headgroup, while some peculiar deviations may be connected with the known difference in the structure between some of the vesicle types studied.

Identification of a haplosufficient 3.6-Mb region in human chromosome 11q14.3-->q21.

Cytogenetic deletions are almost always associated with phenotypic abnormality and are very rarely transmitted. We have located a hitherto undescribed, familial deletion involving the region 11q14.3-->q21 in five individuals in a three-generation kindred. Four of the deletion carriers show no phenotypic abnormality; the other, who is the proband, was investigated for short stature and poor academic progress. In view of the apparent innocuous nature of this genetic imbalance, the deletion was investigated in detail to determine its size (3.6 Mb) and location with reference to molecular markers and genetic content. The deleted region is described by a contig of 37 BACS including the flanking regions, which we have assembled. Several possible contributory factors are considered, which might explain the lack of clinical significance of this large deletion. It is notable that there are few genes in this region and none have known functions. All most likely have copies elsewhere in the genome and a number of other hypothetical genes appear to be members of certain gene families, i.e. none is unique. Part of the region (1 Mb) is also duplicated at the pericentromeric region 11p11. Given the very low proportion of the genome occupied by single copy genes and their uneven distribution, regions such as this, which appear to be functionally haplosufficient, may be more common than hitherto recognised.

Targeted gene correction in the mdx mouse using short DNA fragments: towards application with bone marrow-derived cells for autologous remodeling of dystrophic muscle.

In muscle, mutant genes can be targeted and corrected directly by intramuscular (i.m.) injection of corrective DNA, or by ex vivo delivery of DNA to myogenic cells, followed by cell transplantation. Short fragment homologous replacement (SFHR) has been used to repair the exon 23 nonsense transition at the Xp21.1 dys locus in cultured cells and also, directly in tibialis anterior from male mdx mice. Whilst mdx dys locus correction can be achieved in up to 20% of cells in culture, much lower efficiency is evident by i.m. injection. The major consideration for application of targeted gene correction to muscle is delivery throughout relevant tissues. Systemically injected bone marrow (BM)-derived cells from wt C57BL/10 ScSn mice are known to remodel mdx muscle when injected into the systemic route. Provided that non muscle-derived cell types most capable of muscle remodeling activity can be more specifically identified, isolated and expanded, cell therapy seems presently the most favorable vehicle by which to deliver gene correction throughout muscle tissues. Using wt bone marrow as a model, this study investigates systemic application of bone marrow-derived cells as potential vehicles to deliver corrected (ie wt) dys locus to dystrophic muscle. Intravenous (i.v.) and intraperitoneal (i.p.) injections of wt BM were given to lethally and sub-lethally irradiated mdx mice. Despite both i.v. and surviving i.p. groups containing wt dys loci in 100% and less than 1% of peripheral blood nuclei, respectively, both groups displayed equivalent levels of wt dys transcript in muscle RNA. These results suggest that the muscle remodeling activity observed in systemically injected BM cells is not likely to be found in the hemopoietic fraction.

Gene therapy for inherited lung disorders: an insight into pulmonary defence.

This review summarizes the latest developments in viral and nonviral gene delivery systems to the lung, and the problems that have to be overcome. Gene delivery has the potential to offer effective treatment to patients with life-threatening lung diseases such as cystic fibrosis and alpha(1)-antitrypsin deficiency, and could modify gene-environment relationships in asthma and other respiratory diseases. Phase I clinical trials conducted in the early 1990s showed that in principle gene transfer to the lung was safe. Although the preliminary results gave encouraging laboratory data, gene expression from viral or nonviral gene delivery systems was too inefficient or transient to offer clinical benefit. Initial optimism gave way to the realization that gene therapy to the lung was unlikely to be straightforward. The host innate and acquired immune system, which protects against infection from inhaled bacteria and viruses, represents a major barrier to successful gene transfer to the lung. A better understanding of the immunological barriers which exist in the lung may allow the development of pharmacological and/or immunological agents that modulate the host immune system to allow for a more continuous and regulated level of gene expression following gene transfer.

Fetal nucleated red blood cells from CVS washings: an aid to development of first trimester non-invasive prenatal diagnosis.

Fetal nucleated red blood cells (n-rbc) occur in the maternal circulation from 7 weeks of pregnancy. The enrichment of these cells from maternal blood will depend upon their stage of differentiation, which changes during development. We characterised the fetal n-rbc from chorionic villus sample (CVS) washings and used them to model first trimester non-invasive prenatal diagnosis. The ratio of epsilon- to gamma-globin-producing cells declined rapidly from 10 to 13 weeks, as did the ratio of nucleated to non-nucleated rbc. By 13 weeks the great majority of cells containing gamma- or epsilon-globin are anucleate. The fetal n-rbc were highly variable in size and density and sedimented over a wide density range with a high proportion (>80%) at a density overlapping with that of maternal rbc. We have devised an enrichment procedure using Orskoff lysis to differentially lyse the maternal cells followed by density centrifugation and separation using magnetic beads. This simple protocol allowed recovery of 70% (69+/-22%) of fetal cells when added at approximately 10 fetal cells/ml maternal blood. When 1 fetal cell/ml millilitre maternal blood was added (total volume 10 ml) the recovery was more variable but remained at approximately 70% (72+/-47%), with at least one fetal cell recovered in all cases.

Capability of arsonolipids to transport divalent cations: a Pressman cell study.

The ability of the newly synthesized arsonolipids (2,3-diacyloxyprophlarsonic acids) to transport cations was studied using the Pressman cell. Experimental results demonstrate that arsonolipids are much more efficient carriers of Ca(2+) and Mg(2+) than natural phosphatidic acid in the Pressman cell experiments. The ability of arsonolipids to transfer Ca(2+) is affected by the lipid side chain length in the order: C(12)>>C(14) approximately C(16). Ca(2+) is transferred faster than Mg(2+), suggesting that the latter is more tightly bound to the arsonolipids. The transfer kinetic curves are parabolic for C(12), while initially linear with a tendency to reach a steady state for C(14) and C(16), when the pH in the donor compartment was 8.3. The transport kinetics for both ions studied were best fitted by an equation derived from saturation kinetics that apply in reversible chemical reactions. The ion transfer rates increased as the pH in the donor compartment decreased.

Mapping of the second Friedreich's ataxia (FRDA2) locus to chromosome 9p23-p11: evidence for further locus heterogeneity.

Friedreich's ataxia (FRDA), the most-common form of autosomal recessive ataxia, is inherited in most cases by a large expansion of a GAA triplet repeat in the first intron of the frataxin (X25) gene. Genetic heterogeneity in FRDA has been previously reported in typical FRDA families that do not link to the FRDA locus on chromosome 9q13. We report localization of a second FRDA locus (FRDA2) to chromosome 9p23-9p11, and we provide evidence for further genetic heterogeneity of the disease, in a family with the classic FRDA phenotype.