Right heart function in impaired left ventricular diastolic function: 2D speckle tracking echocardiography–based and Doppler tissue imaging–based analysis of right atrial and ventricular function

Aim

The aim of our study was to describe right atrial (RA) and right ventricular (RV) function, assessed by Doppler tissue imaging and 2D speckle tracking echocardiography (2DSTE), in women with signs of early impaired left ventricular diastolic function (DD).

Methods and Results

In a cross‐sectional trial, standard parameters of diastolic and right heart function were investigated in 438 women of the Berlin Female Risk Evaluation (BEFRI) study. In a subset of women, average peak systolic RA strain (RAS), as well as the average peak systolic RV strain of the free wall (RVS free wall) and of all RV segments (average RV strain; RVS Avg), was analyzed using 2DSTE. Compared to women with normal diastolic function (DD0), RAS, RVS free wall and RVS Avg were significantly reduced in DD (43.1% ± 11.9%, ?26.7% ± 5.6%, and ?23.3% ± 3.5% in DD0; vs 35.1% ± 10.4%, ?23.9% ± 5.5%, and ?20.6% ± 3.8% in DD; P < .01). Peak RV myocardial velocity (RV‐IVV) and acceleration during isovolumetric contraction (RV‐IVA) were markedly higher in DD (15.0 ± 3.9 cm/s and 3.1 ± 1.0 m/s² in DD vs 11.9 ± 3.2 cm/s and 2.8 ± 0.8 m/s² in DD0; P < .05). RAS and RV‐IVV were significantly associated with DD after adjustment to age, BMI, and left atrial strain in multivariate regression analysis.

Conclusion

Systolic right heart function is significantly altered in DD. DTI as well as 2DSTE constitute sensitive echocardiographic tools that enable the diagnosis of impaired right heart mechanics in early‐staged DD.     

Predictors for successful PBSC collection on the fourth day of G‐CSF‐induced mobilization in allogeneic stem cell donors

Peripheral blood stem cells (PBSCs) used for allogeneic transplantation are collected by apheresis after pre‐treatment of donors with G‐CSF. Using modern apheresis devices stem cells can be collected more efficiently. It was studied whether collection on the 4th instead of the 5th day after initiation of G‐CSF treatment might be feasible. Stem cell yields that could have been collected on day 4 were calculated in two cohorts treated with 10 µg/kg G‐CSF once daily (n = 106, cohort I) or 5 µg/kg twice daily schedule (n = 85, cohort II). Harvests were predicted using the median collection efficiency (CE) of the apheresis machine and regarded successful when > 5.0 x10⁶ CD34^+/kg recipient body weight. Successful harvests at day 4 could have been obtained in only 22.6% and 41.2% of donors in cohort I and II respectively, while the expected successful collections on day 5 were 55.7% and 76.5%. Individual donor factors that correlated with a successful harvest on day 4 were weight, BMI, age, ratio donor/recipient weight and total G‐CSF dose in cohort I, whereas ratio donor/recipient weight was the only significant predictor in cohort II. Donor weight, BMI and total G‐CSF dose correlated positively with CD34⁺ values in the blood on day 4 in all donors. However, donor characteristics were not able to be used as strong predictors in daily practice. In conclusion, PBSC collection on day 4 will not result in a successful harvest in most stem cell donors, however using a twice daily G‐CSF scheme increases the yield.     

Touch,the essence of caring for people with end-stage dementia: A mental health perspective in Namaste Care

This article presents the mental health aspects of ‘touch’ associated with a funded research project: Avoiding ‘high tech’ through ‘high touch’ in end-stage dementia: Protocol for care at the end-of-life. These mental health aspects highlight the human need for touch that continues up until and inclusive of the final stages of life. This study was informed by Simard's (2007) ‘high touch’ protocol based on the End-of-Life Namaste Care programme for people with dementia. The article is situated in relation to the research project which used a three-phase mixed methods approach. Data explored in this article are derived from focus groups conducted at three residential aged care facilities located in metropolitan and regional areas of NSW, Australia. The exploration of touch vis-a-vis mental health fell under two broad themes: touch by others and touch by the person. Sub-elements of these themes comprised touch towards a physical objective, touch towards an emotional objective, touch of objects and touch of others. The overarching outcome of interconnectedness embraced environmental awareness and human and life awareness. These two broad themes, with their accompanying elements, express the essential nature of mental health as a reciprocal connectedness, with reciprocal impacts on both those people with advanced dementia and their carers.     

Effect of silica coating and laser treatment on the flexural strength,surface characteristics,and bond strength of a dental zirconia

This study investigated the effect of irradiation with an erbium‐doped yttrium aluminium garnet (Er:YAG) laser and coating with silica on the surface characteristics, bond strength, and flexural strength of dental zirconia. Three hundred and forty‐three standard zirconia specimens were created, and 49 were assigned to each of seven surface treatment groups: (i) no treatment; Er:YAG laser (80 mJ/2 Hz) with pulse widths of 50 μs (ii), 100 μs (iii), 300 μs (iv), or 600 μs (v); or tribochemical silica coating at the partially sintered stage (vi) or after sintering was complete (vii). All specimens were sintered after the surface treatments, except for the group in which specimens were sintered before treatment. The study outcomes were roughness, surface loss, microshear bond strength (μSBS), and biaxial flexural strength (BFS). Mean roughness and surface loss values were significantly higher in specimens from irradiated groups than in those from silica‐coated groups. Regarding μSBS, after aging, specimens from all experimental groups presented very low and similar μSBS values, irrespective of the surface treatment. Silica coating after sintering yielded the highest BFS (1149.5 ± 167.6 MPa), while coating partially sintered specimens with silica resulted a BFS (826.9 ± 60.9 MPa) similar to that of the untreated control group (794.9 ± 101.7 MPa). Laser treatments, irrespective of pulse width used, significantly decreased the BFS. In the group treated with laser at 300 μs pulse width, specimens exhibited the lowest BFS value (514.1 ± 71.5 MPa). Adhesion to zirconia was not stable after aging, regardless of the surface treatment implemented.     

Adaptive response to hydrogen peroxide in yeast: Induction,time course,and relationship to dose–response models

The assay for trp5 gene conversion and ilv1‐92 reversion in Saccharomyces cerevisiae strain D7 was used to characterize the induction of an adaptive response by hydrogen peroxide (H₂O₂). Effects of a small priming dose on the genotoxic effects of a larger challenge dose were measured in exponential cultures and in early stationary phase. An adaptive response, indicated by smaller convertant and revertant frequencies after the priming dose, occurred at lower priming and challenge doses in young, well‐aerated cultures. Closely spaced priming doses from 0.000975 to 2 mM, followed by a 1 mM challenge, showed that the induction of the adaptive response is biphasic. In exponential cultures it was maximal with a priming dose of 0.125–0.25 mM. Very small priming doses were insufficient to induce the adaptive response, whereas higher doses contributed to damage. A significant adaptive response was detected when the challenge dose was administered 10–20 min after the priming exposure. It was fully expressed within 45 min, and the yeast began to return to the nonadapted state after 4–6 hr. Because of the similarity of the biphasic induction to hormetic curves and the proposal that adaptive responses are a manifestation of hormesis, we evaluated whether the low doses of H₂O₂ that induce the adaptive response show a clear hormetic response without a subsequent challenge dose. Hormesis was not evident, but there was an apparent threshold for genotoxicity at or slightly below 0.125 mM. The results are discussed with respect to linear, threshold, and hormesis dose–response models. Environ. Mol. Mutagen. 54:384–396, 2013. © 2013 Wiley Periodicals, Inc.     

Central nervous system diseases related to pathological microglial phagocytosis

Microglia are important phagocytes of the central nervous system (CNS). They play an important role in protecting the CNS by clearing necrotic tissue and apoptotic cells in many CNS diseases. However, recent studies have found that microglia can phagocytose parts of neurons excessively, such as the neuronal cell body, synapse, or myelin sheaths, before or after the onset of CNS diseases, leading to aggravated injury and impaired tissue repair. Meanwhile, reduced phagocytosis of synapses and myelin results in abnormal circuit connections and inhibition of remyelination, respectively. Previous studies focused primarily on the positive effects of microglia phagocytosis, whereas only a few studies have focused on the negative effects. In this review, we use the term "pathological microglial phagocytosis" to refer to excessive or reduced phagocytosis by microglia that leads to structural or functional abnormalities in target cells and brain tissue. The classification of pathological microglial phagocytosis, the composition, and activation of related signaling pathways, as well as the process of pathological phagocytosis in various kinds of CNS diseases, are described in this review. We hypothesize that pathological microglial phagocytosis leads to aggravation of tissue damage and negative functional outcome. For example, excessive microglial phagocytosis of synapses can be observed in Alzheimer's disease and schizophrenia, leading to significant synapse loss and memory impairment. In Parkinson's disease, ischemic stroke, and traumatic brain injury, excessive microglial phagocytosis of neuronal cell bodies causes impaired gray matter recovery and sensory dysfunction. We therefore believe that more studies should focus on the mechanism of pathological microglial phagocytosis and activation to uncover potential targets of therapeutic intervention.