Search results for "Models"
showing 10 items of 8211 documents
Epithelium-derived inhibition of [3H]acetylcholine release from the isolated guinea-pig trachea
1990
To investigate presynaptic, regulatory mechanisms on parasympathetic nerve fibres innervating the airways, the release of newly-synthesized [3H]acetylcholine from the isolated trachea was studied. Reverse phase HPLC followed by liquid scintillation spectrometry was used to separate and quantify the radioactive compounds choline, phosphorylcholine and acetylcholine in the incubation medium and the tissue. During the incubation of the tracheae with [3H]choline a significant synthesis of [3H]acetylcholine (35,000 dpm/preparation) and [3H]phosphorylcholine (500,000 dpm/preparation) occurred. In epithelium-deficient tracheae the formation of [3H]phosphorylcholine was enhanced, whereas the conten…
Changes induced by eccentric training on force-velocity relationships of the elbow flexor muscles.
1995
The aim of this study was to examine the effects of a short term eccentric training period on force-velocity relationships of the elbow flexor muscles. From a muscle model, the maximal shortening velocity Vo(x) and the af parameter which varies according to the curvature of the force-velocity relationship of the muscle were determined. Sixteen volunteer subjects divided into 2 groups participated in this study (Group Eccentric GE, n = 8; Group Control GC, n = 8). The subjects performed, on an isokinetic ergometer, 2 maximal concentric elbow flexions at different angular velocities (60, 120, 180, 240, 300, 360 degrees s-1) and held maximal and submaximal isometric actions at an elbow flexion…
Theoretical basis for the use of non-invasive thermal measurements to assess the brain injury in newborns undergoing therapeutic hypothermia.
2020
AbstractThe aim of this paper is to propose a new non-invasive methodology to estimate thermogenesis in newborns with perinatal asphyxia (PA) undergoing therapeutic hypothermia (TH). Metabolic heat production (with respect to either a neonate’s body mass or its body surface) is calculated from the newborn’s heat balance, estimating all remaining terms of this heat balance utilising results of only non-invasive thermal measurements. The measurement devices work with standard equipment used for therapeutic hypothermia and are equipped with the Global System for Mobile Communications (GSM), which allows one to record and monitor the course of the therapy remotely (using an internet browser) wi…
Causal linear parametric model for baroreflex gain assessment in patients with recent myocardial infarction
2001
Spectral and cross-spectral analysis of R-R interval and systolic arterial pressure (SAP) spontaneous fluctuations have been proposed for noninvasive evaluation of baroreflex sensitivity (BRS). However, results are not in good agreement with clinical measurements. In this study, a bivariate parametric autoregressive model with exogenous input (ARXAR model), able to divide the R-R variability into SAP-related and -unrelated parts, was used to quantify the gain (αARXAR) of the baroreflex regulatory mechanism. For performance assessing, two traditional noninvasive methods based on frequency domain analysis [spectral, baroreflex gain by autogressive model (αAR); cross-spectral, baroreflex gain…
Development of the coronary arteries in a murine model of transposition of great arteries.
2003
Transposition of great arteries in humans is associated with a wide spectrum of coronary artery patterns. However, no information is available about how this pattern diversity develops. We have studied the development of the coronary arteries in mouse embryos with a targeted mutation of perlecan, a mutation that leads to ventriculo-arterial discordance and complete transposition in about 70% of the embryos. The perlecan-deficient embryos bearing complete transposition showed a coronary artery pattern consisting of right and left coronary arteries arising from the morphologically dorsal and ventral sinuses of Valsalva, respectively. The left coronary artery gives rise to a large septal arter…
Finger injuries caused by power-operated windows of motor vehicles: an experimental cadaver study.
2011
The aim of this experimental cadaver study was to investigate which kinds of lesions could occur in jam events between the glass and seal entry of power-operated motor vehicle side door windows at two different closing forces. Ten hands of fresh cadaver specimens were used. Three different hand positions chosen to simulate real events in which a finger is jammed between the glass and seal entry of the window of a current motor vehicle were examined. The index, middle, ring, and little finger of each hand were separately jammed both at the proximal and distal interphalangeal joint at closing forces of 300 and 500 N with a constant window glass closing speed of 10 cm/s. Macroscopically visibl…
The association of bike fitting with injury, comfort, and pain during cycling: An international retrospective survey
2018
Although bike fitting is recommended to help reduce injury risk, little empirical evidence exists to indicate an association between bike fitting and injury incidence. The aim of the study was to determine the effect of bike fitting on self-reported injury, comfort, and pain while cycling from a worldwide survey of cyclists. A total of 849 cyclists completed an online questionnaire between February and October 2016. Questionnaire collected data on respondent demographics, cycling profile, bike fitting, comfort and pain while cycling, and injury history. The main predictor variable was bike fitting (yes, by the respondent, i.e. user bike fitting; yes, by a professional service; or no). Covar…
Predictors of live birth in women with a history of biochemical pregnancies after assisted reproduction treatment
2020
Abstract Objectives To ascertain whether women with a history of biochemical pregnancies (BPs) in in-vitro fertilization (IVF)/intracytoplasmic sperm injection (ICSI) treatment cycles have decreased chances of live birth (LB); and (2) to build a predictive model for LB in this particular population of infertile women. Methods In order to achieve the first objective, data from 1536 women that had a LB using autologous fresh or frozen embryos, or dropped out of further IVF/ICSI treatments after completing one to three unsuccessful treatment cycles were retrospectively analyzed. A subpopulation of 90 women that experienced one or more BPs in our assisted reproduction unit were selected to buil…
Strategies for managing Asherman's syndrome and endometrial atrophy: Since the classical experimental models to the new bioengineering approach
2021
Endometrial function is essential for embryo implantation and pregnancy, but managing endometrial thickness that is too thin to support pregnancy or an endometrium of compromised functionality due to intrauterine adhesions is an ongoing challenge in reproductive medicine. Here, we review current and emerging therapeutic and experimental options for endometrial regeneration with a focus on animal models used to study solutions for Asherman's syndrome and endometrial atrophy, which both involve a damaged endometrium. A review of existing literature was performed that confirmed the lack of consensus on endometrial therapeutic options, though promising new alternatives have emerged in recent ye…
Midregion parathyroid hormone-related protein inhibits growth and invasion in vitro and tumorigenesis in vivo of human breast cancer cells.
2001
Parathyroid hormone-related protein (PTHrP) is critical for normal mammary development and is overexpressed by breast cancers. PTHrP is a peptide hormone that undergoes extensive post-translational processing, and PTHrP(38–94)-amide is one of the mature secretory forms of the peptide. In this study, we explored the effect of PTHrP(38–94)-amide in a panel of six breast cancer cell lines “in vitro” and in MDA-MB231 cells “in vivo” specifically examining cell viability, proliferation, invasiveness, and growth in nude mice. PTHrP(38–94)-amide markedly inhibited proliferation and also caused striking toxicity and accelerated cell death in breast cancer cells. In addition, direct injection of PTH…