EMG amplitude,fatigue threshold,and time to task failure: A meta-analysis

Objectives

Electromyographic (EMG) fatigue threshold (EMG_FT) is utilised as a correlate of critical power, torque, and force thresholds that establishes a theoretical exercise intensity—the power, torque, or force at which the rate of change of EMG amplitude (ΔE$\overline{\mathrm{M}}$G) is zero—below which neuromuscular fatigue is negligible and unpredictable. Recent studies demonstrating neuromuscular fatigue below critical thresholds raise questions about the construct validity of EMG_FT. The purpose of this analysis is to evaluate the construct validity of EMGFT by aggregating ΔE$\overline{\mathrm{M}}$G and time to task failure (T_lim) data.

The lateral chest X-ray: Is it necessary for emergency department patients?

To determine the utility of the lateral view of the chest in emergency department patients, records of all patients who had had 2-view chest x-rays ordered in the emergency department were reviewed retrospectively. A study radiologist recorded a reading of the posteroanterior (PA) radiograph alone. The lateral radiograph was then provided, along with the PA view, and a second reading was recorded. A comparison was then made between the first and second readings.A total of 417 sets of x-rays were included. The PA view alone successfully diagnosed or suspected 92% of pulmonary nodules, 95% of effusions, 97% of cases of emphysema, 98% of pneumonias, and 100% of cases of cardiomegaly, pulmonary edema, interstitial pulmonary disease, and atelectasis.In the emergency department patient population, lateral views of the chest have minimal diagnostic yield and therefore may be used selectively to safely decrease the amount of breast radiation exposure to young women.     

The effect of rectal diclofenac on pruritus in patients receiving intrathecal morphine

In this prospective randomised study, pruritus and pain were evaluated in patients undergoing abdominal surgery in which intrathecal morphine was administered. Each patient received intrathecal morphine 0.3 mg prior to induction, followed by a standard anaesthetic. The patients were randomly allocated to one of two groups. One group received 100 mg of rectal diclofenac immediately post-induction. Patients receiving diclofenac had significantly lower pruritus scores at 30 min (p = 0.0076), 2, 4, 8 and 24 h postoperatively, as well as significantly reduced pain scores at each time point (p < 0.0001 at each study interval). Morphine consumption in the first 24 h was also significantly lower in this group. In conclusion, rectal administration of diclofenac significantly reduces the incidence and severity of postoperative pruritus. It also significantly reduces pain and further analgesic requirements postoperatively.     

Modulation of intein activity by its neighboring extein substrates

Inteins comprise a large family of phylogenetically widespread self-splicing protein catalysts that colonize diverse host proteins. The evolutionary and functional relationship between the intein and the split-host protein, the exteins, is largely unknown. To probe an association, we developed an in vivo and in vitro intein assay based on FRET. The FRET assay reports cleavage of the intein from its N-terminal extein. Applying this assay to randomized extein libraries, we show that the nature of the extein substrate bordering the intein can profoundly influence intein activity. Residues proximal to the intein-splicing junction in both N- and C-terminal exteins can accelerate the N-terminal cleavage rate by >4-fold or attenuate cleavage by 1,000-fold, both resulting in compromised self-splicing efficiency. The existence and the magnitude of extein effects require consideration for maximizing the utility of inteins in biotechnological applications, and they predict biases in intein integration sites in nature.     

Influence of stimulation rate and loudness growth on modulation detection and intensity discrimination in cochlear implant users

In cochlear implants (CIs), increasing the stimulation rate typically increases the electric dynamic range (DR), mostly by reducing audibility thresholds. While CI users’ intensity resolution has been shown to be fairly constant across stimulation rates, high rates have been shown to weaken modulation sensitivity, especially at low listening levels. In this study, modulation detection thresholds (MDTs) were measured in five CI users for a range of stimulation rates (250–2000 pulses per second) and modulation frequencies (5–100 Hz) at 8 stimulation levels that spanned the DR (loudness-balanced across stimulation rates). Intensity difference limens (IDLs) were measured for the same stimulation rates and levels used for modulation detection. For all modulation frequencies, modulation sensitivity was generally poorer at low levels and at higher stimulation rates. CI users were sensitive to modulation frequency only at relatively high levels. Similarly, IDLs were poorer at low levels and at high stimulation rates. When compared directly in terms of relative amplitude, IDLs were generally better than MDTs at low levels. Differences in loudness growth between dynamic and steady stimuli might explain level-dependent differences between MDTs and IDLs. The slower loudness growth associated with high stimulation rates might explain the poorer MDTs and IDLs with high rates. In general, high stimulation rates provided no advantage in intensity resolution and a disadvantage in modulation sensitivity.     

An efficient synthesis of [13C6]‐3,5‐dichloroaniline

3,5‐Dichloroaniline is commonly found in many compounds with pharmacological and other biological activities. [¹³C₆]‐Aniline or its hydrochloride salt was converted in three steps to [¹³C₆]‐3,5‐dichloroaniline, which can be incorporated in compounds of interest and used as internal standards in drug metabolism and pharmacokinetics (DMPK) studies. Copyright © 2008 John Wiley & Sons, Ltd.     

Coculture cells that express leukemia inhibitory factor (LIF) enhance mouse blastocyst developmentin vitro

Purpose Leukemia inhibitory factor is a cytokine that plays an important role in implantation and enhances mouse preimplantation embryo development in vitro.Since leukemia inhibitory factor enhances early embryo development, we tested the hypothesis that coculture cells that express leukemia inhibitory factor would enhance mouse blastocyst development in vitro.In this study, Northern analysis for leukemia inhibitory factor was performed on total RNA extracted from Vero cells, human embryonic, fibroblasts, and human placental fibroblasts.Methods Two-cell mouse embryos were cultured to blastocyst in Ham's F-10 with 15% human cord serum (control) or with the coculture cells. Northern analysis demonstrated expression of LIF mRNA in Vero cells and embryonic fibroblasts but not in placental fibroblasts. Development to blastocyst was significantly enhanced in two-cell embryos cultured with Vero cells (86%, 140/163) and embryonic fibroblasts (83%, 118/142) when compared to controls (71%, 67/94, P<0.05) or placental fibroblasts (71%, 95/134), P<0.05).Conclusion These data suggest that coculture cells that express leukemia inhibitory factor may be superior to nonleukemia inhibitory factor expressing cells for early preimplantation embryo development.Presented at the 50th Annual Meeting of the American Fertility Society, San Antonio, Texas, November 5–10, 1994.