Cell Growth Measurement

The cell is the basic structural and functional unit of all living organisms. As the smallest unit and building blocks of life, cells differ in size, shape, metabolism, reproduction, and growth requirements. Cells reproduce through cell division involving a four-phase (G1, S, G2, M) cell cycle, which is tightly regulated at multiple checkpoints. The resulting growth curve demonstrates that cell population increases in three sequential steps: incubation, exponential hyperplasia, and stagnation/death phases. Cell growth is subject to changes in disease state and/or environmental conditions. This chapter will focus on methods for cell growth measurement, which are grouped into five sections: cell cycle, apoptosis, growth curve, drug-induced proliferation (DIP), and continuous assays. Among the continuous assays, the EZMTT dye allows for long-term tracking of cell growth under various conditions and shows promise in precision medicine by early detection of drug resistance

Mapping of the Insomnia Severity Index and other sleep measures to EuroQol EQ-5D health state utilities

<p>Abstract</p> <p>Background</p> <p>This study sought to map the Insomnia Severity Index (ISI) and symptom variables onto the EQ-5D.</p> <p>Methods</p> <p>A cross-sectional survey was conducted among adult US residents with self-reported sleep problems. Respondents provided demographic, comorbidity, and sleep-related information and had completed the ISI and the EQ-5D profile. Respondents were classified into ISI categories indicating no, threshold, moderate, or severe insomnia. Generalized linear models (GLM) were used to map the ISI's 7 items (Model I), summary scores (Model II), clinical categories (Model III), and insomnia symptoms (Model IV), onto the EQ-5D. We used 50% of the sample for estimation and 50% for prediction. Prediction accuracy was assessed by mean squared errors (MSEs) and mean absolute errors (MAEs).</p> <p>Results</p> <p>Mean (standard deviation) sleep duration for respondents (N = 2,842) was 7.8 (1.9) hours, and mean ISI score was 14.1 (4.8). Mean predicted EQ-5D utility was 0.765 (0.08) from Models I-III, which overlapped with observed utilities 0.765 (0.18). Predicted utility using insomnia symptoms was higher (0.771(0.07)). Based on Model I, predicted utilities increased linearly with improving ISI (0.493 if ISI = 28 vs. 1.00 if ISI = 0, p < 0.01). From Model II, each unit decrease in ISI summary score was associated with a 0.022 (p < 0.001) increase in utility. Predicted utilities were 0.868, 0.809, 0.722, and 0.579, respectively, for the 4 clinical categories, suggesting that lower utility was related to greater insomnia severity. The symptom model (Model IV) indicated a concave sleep-duration function of the EQ-5D; thus, utilities diminished after an optimal amount of sleep. The MSEs/MAEs were substantially lower when predicting EQ-5D > 0.40, and results were comparable in all models.</p> <p>Conclusions</p> <p>Findings suggest that mapping relationships between the EQ-5D and insomnia measures could be established. These relationships may be used to estimate insomnia-related treatment effects on health state utilities.</p

Influence of Reducing Agents on Biosafety and Biocompatibility of Gold Nanoparticles

Extensive biomedical applications of nanoparticles are mainly determined by their safety and compatibility in biological systems. The aim of this study was to compare the biosafety and biocompatibility of gold nanoparticles (GNPs) prepared with HEPES buffer, which is popular for cell culture, and sodium citrate, a frequent reducing agent. From experimental results on the body weight and organ coefficients of acute oral toxicity tests, it could be observed that HEPES-prepared GNPs are biologically safer than citric-prepared GNPs at the same dose of 500 μg/kg. The in vitro cell viability was higher for HEPES-prepared GNPs than citric-prepared GNPs at 5.0- and 10.0-ug/mL concentrations. More reactive oxygen species (ROS) were generated in the cell suspension when supplemented with citric-prepared GNPs than HEPES-prepared GNPs when their concentrations were higher than 20 μg/mL. The results stated that HEPES-prepared GNPs had better biosafety and biocompatibility than citric-prepared GNPs. This study not only revealed the influence of reducing agent on biosafety and biocompatibility of nanomaterials but also provided accumulative evidence for nanomaterials in biomedical applications. [Figure: see text

Structure, optical, and magnetic properties of sputtered manganese and nitrogen-codoped ZnOZnO films

To realize the hole-mediated ferromagnetism, manganese and nitrogen-codoped ZnOZnO (Zn1−xMnxO:N)(Zn1−xMnxO:N) films were prepared on sapphire (0001)(0001) by reactive radio-frequency (rf) magnetron sputtering from Zn0.97Mn0.03OZn0.97Mn0.03O ceramic targets using N2N2 gas. X-ray photon spectra reveal that the doped Mn ions are mainly in divalent states and the coexistence of O–ZnO–Zn and N–ZnN–Zn bonds in the films. According to the absorption spectra, the band gap of Zn0.97Mn0.03O:NZn0.97Mn0.03O:N films is about 3.15 eV3.15eV, which is slightly lower than that of ZnOZnO films (3.20 eV)(3.20eV). Compared with Zn0.97Mn0.03OZn0.97Mn0.03O films, ferromagnetic behavior of Zn0.97Mn0.03O:NZn0.97Mn0.03O:N films were significantly changed with a coercivity of about 70 Oe70Oe, a saturation magnetization of 0.92 μB/Mn2+0.92μB∕Mn2+ and a remanance over 0.15 μB/Mn2+0.15μB∕Mn2+ at 300 K300K, while at 10 K10K, they increased to be about 110 Oe110Oe, 1.05 μB/Mn2+1.05μB∕Mn2+ and 0.23 μB/Mn2+0.23μB∕Mn2+, respectively. However, rapid thermal annealing treatment in pure oxygen results in a significant decrease on the magnetic properties of the films.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/87789/2/082111_1.pd

Perpendicular in-plane negative magnetoresistance in ZrTe5

The unique band structure in topological materials frequently results in unusual magneto-transport phenomena, one of which is in-plane longitudinal negative magnetoresistance (NMR) with the magnetic field aligned parallel to the electrical current direction. This NMR is widely considered as a hallmark of chiral anomaly in topological materials. Here we report the observation of in-plane NMR in the topological material ZrTe5 when the in-plane magnetic field is both parallel and perpendicular to the current direction, revealing an unusual case of quantum transport beyond the chiral anomaly. We find that a general theoretical model, which considers the combined effect of Berry curvature and orbital moment, can quantitatively explain this in-plane NMR. Our results provide new insights into the understanding of in-plane NMR in topological materials

Eliciting health state utilities for Dupuytren's contracture using a discrete choice experiment

Background and purpose An internet-based discrete choice experiment (DCE) was conducted to elicit preferences for a wide range of Dupuytren’s contracture (DC)-related health states. An algorithm was subsequently developed to convert these preferences into health state utilities that can be used to assess DC’s impact on quality of life and the value of its treatments. Methods Health state preferences for varying levels of DC hand severity were elicited via an internet survey from a sample of the UK adult population. Severity levels were deined using a combination of contractures (0, 45, or 90 degrees) in 8 proximal interphalangeal and metacarpophalangeal joints of the index, middle, ring, and little ingers. Right-handed, left-handed, and ambidextrous respondents indicated which hand was preferable in each of the 10 randomly-selected hand-pairings comparing different DC severity levels. For consistency across comparisons, anatomically precise digital hand drawings were used. To anchor preferences onto the traditional 0–1 utility scale used in health economic evaluations, unaffected hands were assigned a utility of 1.0 whereas the utility for a maximally affected hand (i.e., all 8 joints set at 90 degrees of contracture) was derived by asking respondents to indicate what combination of attributes and levels of the EQ-5D-5L proile most accurately relects the impact of living with such hand. Conditional logistic models were used to estimate indirect utilities, then rescaled to the anchor points on the EQ-5D-5L. Results Estimated utilities based on the responses of 1,745 qualiied respondents were 0.49, 0.57, and 0.63 for completely affected dominant hands, non-dominant hands, or ambidextrous hands, respectively. Utility for a dominant hand with 90-degree contracture in t h e metacarpophalangeal joints of the ring and little ingers was estimated to be 0.89. Separately, reducing the contracture of metacarpophalangeal joint for a little inger from 50 to 12 degrees would improve utility by 0.02. Interpretation DC is associated with substantial utility decrements. The algorithms presented herein provide a robust and lexible framework to assess utility for varying degrees of DC severity

Implications of MMP9 for Blood Brain Barrier Disruption and Hemorrhagic Transformation Following Ischemic Stroke.

Numerous studies have documented increases in matrix metalloproteinases (MMPs), specifically MMP-9 levels following stroke, with such perturbations associated with disruption of the blood brain barrier (BBB), increased risk of hemorrhagic complications, and worsened outcome. Despite this, controversy remains as to which cells release MMP-9 at the normal and pathological BBB, with even less clarity in the context of stroke. This may be further complicated by the influence of tissue plasminogen activator (tPA) treatment. The aim of the present review is to examine the relationship between neutrophils, MMP-9 and tPA following ischemic stroke to elucidate which cells are responsible for the increases in MMP-9 and resultant barrier changes and hemorrhage observed following stroke