Reproducibility of left ventricular mass measurements by two-dimensional and M-mode echocardiography

AbstractBoth two-dimensional and M-mode echocardiography provide accurate estimates of left ventricular mass. However, their reproducibility in serial studies has not been compared, although this issue is critical to evaluation of regression of hypertrophy. To determine which technique provides more reproducible estimates of left ventricular mass, three serial studies were performed prospectively in each of eight normal adults over 5 months. Both two-dimensional and M-mode echocardiograms were obtained at each of these 24 studies. Measurements were performed by two independent observers who did not know patient identity. For the two-dimensional method, left ventricular mass was determined with use of a computer light-pen system and the truncated ellipsoid formula. For the M-mode method, mass was calculated from Penn convention measurements with use of the cube formula.At study 1 the group mean left ventricular mass by two-dimensional echocardiography (115 ± 20 g) did not differ from that by M-mode study (127± 37 g, p = NS). However, serial estimates of left ventricular mass were more reproducible by two-dimensional echocardiography. The mean difference among the three serial two-dimensional studies in each individual was 4.8 ± 4 g (4.2 ± 3%) by the two-dimensional method, but was 18.5 ± 13 g (14.9 ± 10%) by the M-mode method (p = 0.01). Interobserver results for left ventricular mass by two-dimensional echocardiography correlated closely (r = 0.95, n = 24, p < 0.001).The superior reproducibility of two-dimensional echocardiographic estimates of left ventricular mass in normal adults supports the use of two-dimensional echocardiography when serial studies are to be performed

An experimental investigation of chatter effects on tool life

Tool wear is one of the most important considerations in machining operations as it affects surface quality and integrity, productivity and cost. The most commonly used model for tool life analysis is the one proposed by F.W. Taylor about a century ago. Although the extended form of this equation includes the effects of important cutting conditions on tool wear, tool life studies are mostly performed under stable cutting conditions where the effect of chatter vibrations are not considered. This paper presents an empirical attempt to understand tool life under vibratory cutting conditions. Tool wear data are collected in turning and milling on different work materials under stable and chatter conditions. The effects of cutting conditions as well as severity of chatter on tool life are analyzed. The results indicate significant reduction in tool life due to chatter as expected. They also show that the severity of chatter, and thus the vibration amplitude, strongly reduces the life of cutting tools. These results can be useful in evaluating the real cost of chatter by including the reduced tool life. They can also be useful in justifying the cost of chatter suppression and more rigid machining systems

Increased brain-derived neurotrophic factor (BDNF) protein concentrations in mice lacking brain serotonin

The interplay between BDNF signaling and the serotonergic system remains incompletely understood. Using a highly sensitive enzyme-linked immunosorbent assay, we studied BDNF concentrations in hippocampus and cortex of two mouse models of altered serotonin signaling: tryptophan hydroxylase (Tph)2-deficient (Tph2 (-/-)) mice lacking brain serotonin and serotonin transporter (SERT)-deficient (SERT(-/-)) mice lacking serotonin re-uptake. Surprisingly, hippocampal BDNF was significantly elevated in Tph2 (-/-) mice, whereas no significant changes were observed in SERT(-/-) mice. Furthermore, BDNF levels were increased in the prefrontal cortex of Tph2 (-/-) but not of SERT(-/-) mice. Our results emphasize the interaction between serotonin signaling and BDNF. Complete lack of brain serotonin induces BDNF expression

Introduction to the Anti-Racism Virtual Issue of the Journal of Occupational Science

The anti-racism virtual issue of the Journal of Occupational Science (JOS) came about after the Editorial Board expressed its commitment to anti-racist work, publishing the position statement ‘A Pledge to Mobilize Against Racism’ (Stanley et al., 2020). In this statement, the Board promised to republish a collection of articles to call attention to racism and its impact on individuals’ doing and society. The intent is to stimulate critical reflection on the contribution occupational scientists can make to exposing and countering racism in everyday doing. As such, the anti-racism virtual issue helps meet a pressing need to recognize the power of occupation in shaping and reproducing social ideologies, attitudes, and behaviors. We, the authors, urge all occupational scientists to build on this knowledge and continue learning about racism to better understand and address how its different dimensions manifest through occupation and everyday life

Brain serotonin critically contributes to the biological effects of electroconvulsive seizures

Compounds targeting serotonin (5-HT) are widely used as antidepressants. However, the role of 5-HT in mediating the effects of electroconvulsive seizure (ECS) therapy remains undefined. Using Tph2(-/-) mice depleted of brain 5-HT, we studied the effects of ECS on behavior and neurobiology. ECS significantly prolonged the start latency in the elevated O-Maze test, an effect that was abolished in Tph2(-/-) mice. Furthermore, in the absence of 5-HT, the ECS-induced increase in adult neurogenesis and in brain-derived neurotrophic factor signaling in the hippocampus were significantly reduced. Our results indicate that brain 5-HT critically contributes to the neurobiological responses to ECS

Multifocal Vasculopathy Due to Varicella-Zoster Virus (VZV): Serial Analysis of VZV DNA and Intrathecal Synthesis of VZV Antibody in Cerebrospinal Fluid

Recognition of multifocal vasculopathy due to varicella-zoster virus (VZV) is often problematic. We describe a human immunodeficiency virus—infected patient who had progressive central nervous system disease for >3 months. Both VZV DNA and antibody were detected in cerebrospinal fluid (CSF) specimens; serial polymerase chain reaction analyses confirmed the diagnosis and guided the duration of therapy. Reduced ratios of VZV antibody in serum to that in CSF were also demonstrate

Gender-specific association of adiponectin as a predictor of progression of chronic kidney disease: The Mild to Moderate Kidney Disease Study

Progressive renal vascular sclerosis is a key feature of chronic kidney disease (CKD). Adiponectin, an adipokine with potent anti-inflammatory and antiatherosclerotic properties, is associated with insulin resistance, type II diabetes and cardiovascular disease. In this study, we evaluated the predictive value of adiponectin for the progression of CKD in patients enrolled in the Mild to Moderate Kidney Disease Study. The primary end point was defined as a doubling of the baseline serum creatinine and/or terminal renal failure in 177 patients who completed a prospective follow-up of 7 years. Patients who reached a progression endpoint (n=65) were significantly older, had higher baseline serum creatinine, proteinuria and adiponectin concentrations and more components of the metabolic syndrome. A gender-stratified Cox model revealed adiponectin in men as a significant predictor of progression after adjustment for age, glomerular filtration rate, and proteinuria. Male patients with adiponectin levels above their ROC analysis-derived optimal cutoff of 4μg/ml had a significantly faster progression than patients below this point. This prospective long-term study in patients with CKD indicates high adiponectin as a novel independent predictor of disease progression in men but not in women. Our observation may be relevant for other conditions of progressive vascular sclerosis and diabetic nephropathy

A crucial role for HVEM and BTLA in preventing intestinal inflammation

The interaction between the tumor necrosis factor (TNF) family member LIGHT and the TNF family receptor herpes virus entry mediator (HVEM) co-stimulates T cells and promotes inflammation. However, HVEM also triggers inhibitory signals by acting as a ligand that binds to B and T lymphocyte attenuator (BTLA), an immunoglobulin super family member. The contribution of HVEM interacting with these two binding partners in inflammatory processes remains unknown. In this study, we investigated the role of HVEM in the development of colitis induced by the transfer of CD4(+)CD45RB(high) T cells into recombination activating gene (Rag)(-/-) mice. Although the absence of HVEM on the donor T cells led to a slight decrease in pathogenesis, surprisingly, the absence of HVEM in the Rag(-/-) recipients led to the opposite effect, a dramatic acceleration of intestinal inflammation. Furthermore, the critical role of HVEM in preventing colitis acceleration mainly involved HVEM expression by radioresistant cells in the Rag(-/-) recipients interacting with BTLA. Our experiments emphasize the antiinflammatory role of HVEM and the importance of HVEM expression by innate immune cells in preventing runaway inflammation in the intestine

Efficient metallic spintronic emitters of ultrabroadband terahertz radiation

Terahertz electromagnetic radiation is extremely useful for numerous applications such as imaging and spectroscopy. Therefore, it is highly desirable to have an efficient table-top emitter covering the 1-to-30-THz window whilst being driven by a low-cost, low-power femtosecond laser oscillator. So far, all solid-state emitters solely exploit physics related to the electron charge and deliver emission spectra with substantial gaps. Here, we take advantage of the electron spin to realize a conceptually new terahertz source which relies on tailored fundamental spintronic and photonic phenomena in magnetic metal multilayers: ultrafast photo-induced spin currents, the inverse spin-Hall effect and a broadband Fabry-P\'erot resonance. Guided by an analytical model, such spintronic route offers unique possibilities for systematic optimization. We find that a 5.8-nm-thick W/CoFeB/Pt trilayer generates ultrashort pulses fully covering the 1-to-30-THz range. Our novel source outperforms laser-oscillator-driven emitters such as ZnTe(110) crystals in terms of bandwidth, terahertz-field amplitude, flexibility, scalability and cost.Comment: 18 pages, 10 figure