Feasibility and role of echocontrast evaluation of patients with LVAD

Funding Acknowledgements

Type of funding sources: None.

Background

In patients with Advanced heart failure (AHF) long-term support with durable mechanical circulatory support (MCS) devices such as left ventricular assist device (LVAD) brings survival benefits and improvement in quality of life, compared with conventional medical treatments. Development of RVF in patients with LVAD has a direct effect on mortality and is associated with prolonged length of stay in intensive care unit and in-hospital stay and with poor quality of life. Purpose: the evaluation of clinical safety and feasibility of  echocontrast (EC) in patients implanted with 3 different types of LVAD (HeartWAre HVAD, Jarvik 2000, HeartMate 3); the assessment of the improvement in the visualization of heart structures; the intra and inter-operator agreement of RV measurements (FAC, TAPSE, sPAP, TR,  regional wall motion abnormalities) with and without contrast. Methods: Between 2014 and 2019, 43 patients were implanted with LVAD, in particular 7 (16%) patients were implanted with Jarvik 2000, 31 (72%) with HeartMAte 3, 5 (12%) pts with HeartWAre HVAD. Nine patients (21%) either had contraindication or refused contrast injection. In 3 (7%) patients, it was technically challenging to obtain apical images at all levels. Two (5%) patients lost their follow-up. Our final population was of 29 (67%) patients. We also assessed the reproducibility of these measurements between two different expert operators (blind analysis). Results:  We observed no allergic reaction to EC. Total 329 (64%) of 516 RV wall segments were available for qualitative analysis without contrast vs 451 (87%) with contrast (p < 0.001) with a significant improvement of the evaluability of regional contractility and FAC  (41% vs 90%, p < 0.001). Evaluation of TAPSE, TR and sPAP was similar with and without contrast (p = NS) All the RV parameters showed little inter-operator variability when measured with contrast. TAPSE, FAC, and RWMA showed an excellent reproducibility (ICC >0.86) while it was good for 2D-baseline derived parameters (ICC = 0.74) showing improvement of inter operator reproducibility in the evaluation of regional contractility in the contrast echocardiography modality. Conclusion: EC is safe with all the types of LVAD we examined. Accurate and reproducible visualization of RV is imperative for reliability of information, a routine use of EC could play a pivotal role in interpreting RV features.  EC improves RV morphologic and functional judgment; allowing greater accuracy and precision in the assessment of both global and regional RV functions. This finding may have important clinical improvement, especially in the future for analysis focused in RV prognostic role in LVAD patients

DNA-based identifications reveal multiple introductions of the vegetable leafminer Liriomyza sativae (Diptera: Agromyzidae) into the Torres Strait Islands and Papua New Guinea

Leafmining flies (Diptera: Agromyzidae) can be serious economic pests of horticultural crops. Some genera such as Liriomyza are particularly problematic with numerous species, some of which are highly polyphagous (wide host range), which can only be confidently identified morphologically from adult males. In our study, DNA barcoding was employed to establish new locality records of the vegetable leafminer fly, Liriomyza sativae, from the islands of Torres Strait (Queensland, Australia) and the central highlands of Papua New Guinea (PNG). These records represent significant range extensions of this highly invasive plant pest. Specimens of immature leafminers (from leaf mines) were collected over a 5-year period during routine plant health surveys in ethanol or on FTA® filter paper cards, both methods proved effective at preserving and transporting insect DNA under tropical conditions, with FTA cards possessing some additional logistical benefits. Specimens were identified through sequencing two sections of the cytochrome oxidase I gene and the utility of each was assessed for the identification of species and intra-specific genetic lineages. Our study indicates that multiple haplotypes of L. sativae occur in PNG, while a different haplotype is present in the Torres Strait, with genetic regionalization between these areas apart from a single possible instance - one haplotype 'S.7' appears to be common between these two regions - interestingly this has also been the most common haplotype detected in previous studies of invasive L. sativae populations. The DNA barcoding methods employed here not only identified multiple introductions of L. sativae, but also appear generally applicable to the identification of other agromyzid leafminers (Phytomyzinae and Agromyzinae) and should decrease the likelihood of potentially co-amplifying internal hymenopteran parasitoids. Currently, L. sativae is still not recorded from the Australian mainland; however, further sampling of leafminer flies from Northern Australia and surrounding areas is required, as surveillance for possible Liriomyza incursions, as well as to characterize endemic species with which Liriomyza species might be confused.

Trace element levels in adult patients with proteinuria

AIM

Trace elements are involved in many metabolic processes. They circulate prevalently bound to protein. In literature few studies deal with metal metabolism in adult patients with proteinuria, so we decided to further investigate metal metabolism in proteinuric patients.

METHODS

We studied 27 patients (14 male, 13 female), mean age 61.6+/-17 years with different degrees of renal function, serum albumin and proteinuria. Metal concentrations of copper (Cu), zinc (Zn) and aluminum (Al) were measured in serum and urine. No patient had environmental exposure to these metals.

RESULTS

The serum Zn level was below the normal range in 11 patients. The serum Cu level was reduced in 5 patients. The Al serum level was elevated in 4 patients. Six patients had reduced and 6 patients had elevated Zn excretion. The urinary Cu excretion was elevated in 6 patients. The urinary Al excretion was elevated in 1 patient. Trace metal concentrations were related neither to renal function nor to total serum protein or albumin levels. Serum zinc was directly correlated with proteinuria and urinary zinc and negatively correlated with testosterone levels in both sexes.

CONCLUSION

Adult patients with proteinuria have several modification of trace metal concentration in serum and urine. Serum concentration of metals did not depend on renal function or serum protein levels. Urinary Zn excretion was directly related to proteinuria and serum Zn levels. A negative correlation between serum Zn levels and testosterone was found in both sexes. Renal failure reduced urinary excretion of Cu and Al.

The breeding season diet of wedge-tailed eagles (Aquila audax) in western New South Wales and the influence of Rabbit Calicivirus Disease

A total of 2071 individual prey items were identified from 34 active and 55 inactive wedge-tailed eagle nests following the 1995, 1996 and 1997 breeding seasons. Overall, the eagle's diet was comparable to that reported in other studies within semi-arid regions, with rabbits, reptiles and macropods accounting for 47.8, 22.6 and 13.7% of prey items, respectively. In spring 1996 rabbit calicivirus moved into the study area, resulting in a 44-78% reduction in rabbit abundance (Sharp et al. 2001). An index was developed to enable the time since death for individual prey items to be approximated and a historical perspective of the eagle's diet to be constructed. Rabbits constituted 56-69% of dietary items collected during the pre-rabbit calicivirus disease (RCD) samples, but declined to 31% and 16% in the two post-RCD samples. A reciprocal trend was observed for the proportion of reptiles in the diet, which increased from 8-21% of pre-RCD dietary items to 49-54% after the advent of RCD. Similarly, the proportion of avian prey items was observed to increase in the post-RCD samples. These data suggested that prey switching may have occurred following the RCD epizootic. However, a lack of data on the relative abundances of reptiles and birds prevented an understanding of the eagle's functional responses to be developed and definitive conclusions to be drawn. Nevertheless, the eagles were observed to modify their diet to the change in rabbit densities by consuming larger quantities of native prey species.

Long-term exposure to high glucose up-regulates VCAM-induced endothelial cell adhesiveness to PBMC

BACKGROUND

The changes induced on endothelial cells by a long-term exposure to high glucose, a situation that mimics the hyperglycemia of diabetics, have not yet been determined. We compared short- and long-term effects of elevated glucose on macrovascular and microvascular endothelial cells.

METHODS

Endothelial cells were grown in high-glucose media for 24 hours and for 8 weeks. Cell proliferation was evaluated by cell counting, apoptosis and expression of adhesion molecules by flow cytometry; nitric oxide (NO) by measuring the concentration of nitrite/nitrate in the cell supernatant; alpha 2(IV) collagen mRNA and protein by reverse transcriptase-polymerase chain reaction and enzyme-linked immunosorbent assay, respectively. The adhesion of peripheral blood mononuclear cells (PBMCs) to endothelial cells was evaluated by adhesion assay. In some experiments, endothelial cells were preincubated with anti-vascular cell adhesion molecule-1 (VCAM-1) and anti-receptor for advanced glycation end product (RAGE) blocking antibodies.

RESULTS

At 24 hours, but not at 8 weeks, high glucose increased endothelial cell proliferation and apoptosis. High glucose did not modify NO synthesis at 24 hours and 8 weeks. Collagen production and expression were increased only after eight weeks. VCAM-1 but not intercellular adhesion molecule-1 was up-regulated after 8 weeks, a change not observed after 24 hours. The adhesion of PBMCs was significantly increased at eight weeks and was completely abrogated by anti--VCAM-1 and by anti-RAGE antibodies. After 24 hours, there was a modest increase of PBMC adhesion that was not blunted by anti-RAGE antibodies.

CONCLUSIONS

Increased adhesion of PBMCs, caused by up-regulation of VCAM-1 with a mechanism involving advanced glycation end product (AGE) adducts, and augmented collagen deposition are critical effects of long-term high glucose on endothelial cells, and may eventually promote the atherosclerotic process.

Cyclosporine induces different responses in human epithelial, endothelial and fibroblast cell cultures

BACKGROUND

Nephrotoxicity, accelerated atherosclerosis, and graft vascular disease are common complications of cyclosporine long-term treatment characterized by a wide disruption of organ architecture with increased interstitial areas and accumulation of extracellular matrix (ECM). How cyclosporine induces these changes is not clear, but it is conceivable that they are the sum of changes induced at the cell level.

METHODS

We studied the effects of cyclosporine on human endothelial (HEC), epithelial (HK-2), and fibroblast (MRC5) cells. Cell proliferation was evaluated by cell counting, apoptosis and collagen production by enzyme-linked immunosorbent assay, and nitric oxide by measuring the concentration of nitrite/nitrate in the cell supernatant. (alpha1)I and (alpha2)IV collagen, matrix metalloprotease-9 (MMP9), and tissue inhibitors of metalloprotease-1 (TIMP-1) mRNA levels were measured by reverse transcription-polymerase chain reaction. Proteolytic activity was evaluated by zymography.

RESULTS

Cyclosporine showed a marked antiproliferative and proapoptotic effect on endothelial and epithelial cells. Fibroblast growth was not affected by cyclosporine. Nitric oxide was up-regulated by cyclosporine in epithelial cells and fibroblasts but not in endothelial cells. (alpha1)I and (alpha2)IV collagen synthesis was increased in cyclosporine-treated endothelial and epithelial cells, respectively. Proteolytic activity was increased in endothelial and epithelial cells. TIMP-1 mRNA was up-regulated by cyclosporine in fibroblasts.

CONCLUSIONS

Our results demonstrate that cyclosporine exhibits an antiproliferative effect on endothelial and epithelial cells. This effect is associated with induction of apoptosis probably via nitric oxide up-regulation in epithelial cell cultures. Cyclosporine treatment induces ECM accumulation by increasing collagen synthesis in endothelial and epithelial cells and reducing its degradation by up-regulating TIMP-1 expression in fibroblasts. We conclude that cyclosporine affects cell types differently and that the disruption of organ architecture is the result of multiple effects at the cell level.

Risk factors for chronic renal dysfunction in cardiac allograft recipients

Renal dysfunction is one of the most common and threatening complications in heart transplant recipients. Even if ciclosporin seems to play a central role in inducing renal damage, other factors may concur or predispose to renal injury. In order to identify factors responsible for renal dysfunction, we retrospectively studied a cohort of 114 cardiac transplant recipients during a follow-up period of at least 3 years. The patients had a normal renal function before and 0.5 months after heart transplantation. Doubling of baseline serum creatinine or attainment of serum creatinine steadily above 176.8 micromol/l (2.0 mg/dl) was used as criterion to define the end-point renal dysfunction. A series of clinical and laboratory variables were obtained from the patients' charts at different time intervals, and their prognostic value for the occurrence of renal dysfunction was calculated by Cox proportional hazards models. 23 out of 114 patients reached the end point after a median time period of 21 months. High serum triglyceride, alanine aminotransferase, alkaline phosphatase, ciclosporin, urea, glucose, and hemoglobin levels were shown to be associated with the development of renal dysfunction. Four variables, i.e., triglyceride, ciclosporin, urea, and alkaline phosphatase, had an independent prognostic value. Our results confirm a role for ciclosporin in inducing renal dysfunction and identify hyperlipidemia and an increased plasma urea level as risk factors for renal dysfunction in heart transplant recipients.

Plant low-molecular-weight phospholipase A2S (PLA2s) are structurally related to the animal secretory PLA2s and are present as a family of isoforms in rice (Oryza sativa)

Recently, we purified to homogeneity and characterized a low-molecular-weight calcium-dependent phospholipase A2 (PLA2) from developing elm seed endosperm. This represented the first purified and characterized PLA2 from a plant tissue. The full sequences of two distinct but homologous rice (Oryza sativa) cDNAs are given here. These encode mature proteins of 1 19 amino acids (PLA2-I, preceded by a 19 amino acid signal peptide) and 128 amino acids (PLA2-II. preceded by a 25 amino acid signal peptide), and were derived from four expressed sequence tag (EST) clones. Both proteins were homologous to the N-terminal amino acid sequence of the elm PLA2. They contained twelve conserved cysteine residues and sequences that are likely to represent the Ca(2+)-binding loop and active-site motif, which are characteristic of animal secretory PLA2s. A soluble PLA2s activity was purified 145 000-fold from green rice shoots. This had the same biochemical characteristics as the elm and animal secretory PLA2s. The purified rice PLA2 consisted of two proteins, with a molecular weight of 12 440 and 12 920, that had identical N-terminal amino acid sequences. This sequence was different from but homologous to the PLA2-I and PLA2-II sequences. Taken together, the results suggest that at least three different low-molecular-weight PLA2s are expressed in green rice shoots. Southern blot analysis suggested that multiple copies of such genes are likely to occur in the rice and in other plant genomes.

Stimulation of hepatocyte growth factor in human acute renal failure

Hepatocyte growth factor (HGF) is a potent mitogen for tubular cells. Experimental injury to the kidney is associated with HGF release both locally and by distant organs stimulated by circulating 'injurins'. In this study, the serum HGF concentration was measured in patients with acute renal failure (ARF). Normal subjects and chronic renal failure patients either not on dialysis or on regular dialysis treatment served as controls. Human mesangial cells were incubated with sera from ARF patients and controls. The serum HGF concentration was strikingly increased in ARF patients (478 +/- 68 ng/dl) and was normal in chronic renal failure patients not on dialysis (20 +/- 3 ng/dl) and in those on regular dialysis treatment (25 +/- 3 ng/dl). Serum of ARF patients strongly stimulated HGF release from mesangial cells (1,384 +/- 55 ng/ml) in comparison with normal serum (67 +/- 10 ng/ml). These results indicate that in ARF HGF participates in tubular repair both as an endocrine factor, released in the circulation, and as a paracrine substance, diffusing to the tubules from the mesangium.