Fifteen-minute consultation: Recognition and management of the child or young person who has ingested a novel psychoactive substance.

Intoxicated children and young people (CYP) attending the paediatric emergency department (PED) are typically under the influence of alcohol or established recreational agents such as cannabis or ecstasy. The last decade or so has seen an increase in the numbers of CYP in PED who have used novel psychoactive substances (NPS). In this review, we describe four different functional classes of NPS, their legal status, clinical effects, acute management and interventions to reduce harm.

Characteristics of calves produced with sperm sexed by flow cytometry/cell sorting.

The objectives of this study were to determine whether calves produced by sexed sperm differed from controls and to what extent the sex ratio of calves was altered by the sexing procedure. Data were collected from 1,169 calves produced from sperm sexed by flow cytometry/cell sorting after staining with Hoechst 33342, and 793 calves produced from control sperm during breeding trials between 1997 and 2001. Least squares ANOVA were completed using factors of treatment (sexed vs.

Electrical stimulation for therapy and mobility after spinal cord injury.

This article reviews the use of therapeutic and functional electrical stimulation in subjects after a spinal cord injury (SCI). Muscles become much weaker and more fatigable, while bone density decreases dramatically after SCI. Therapeutic stimulation of paralyzed muscles for about 1 h/day can reverse the atrophic changes and markedly increase muscle strength and endurance as well as bone density.

Staircase in mammalian muscle without light chain phosphorylation.

In disuse atrophied skeletal muscle, the staircase response is virtually absent and light chain phosphorylation does not occur. The purpose of the present study was to determine if staircase could be restored in atrophied muscle with continued absence of myosin light chain phosphorylation, by reducing what appears to be an otherwise enhanced calcium release. Control (untreated) and sham-operated female Sprague-Dawley rats were compared with animals after 2 weeks of complete inactivity induced by tetrodotoxin (TTX) application to the left sciatic nerve.

Caffeine and length dependence of staircase potentiation in skeletal muscle.

Skeletal muscle sensitivity to Ca2+ is greater at long lengths, and this results in an optimal length for twitch contractions that is longer than optimal length for tetanic contractions. Caffeine abolishes this length dependence of Ca2+ sensitivity. Muscle length (ML) also affects the degree of staircase potentiation.

Attenuation of myosin light chain phosphorylation and posttetanic potentiation in atrophied skeletal muscle.

Previously we have demonstrated that the absence of staircase potentiation in atrophied rat gastrocnemius muscle is accompanied by a virtual absence of phosphorylation of the regulatory light chains (R-LC) of myosin. It was our purpose in the present study to determine if posttetanic potentiation and corresponding R-LC phosphorylation were also attenuated in disuse-atrophied muscles. Two weeks after a spinal hemisection (T12), twitch and tetanic contractile characteristics were measured in situ in control, sham-treated and atrophied (hemisected) muscles.

Inhibition of Ca2+ release in rat atrophied gastrocnemius muscle.

Contractile parameters of a twitch contraction and changes in these parameters during repetitive stimulation are modified by muscle atrophy induced by tetrodotoxin (TTX). These altered parameters included developed tension (DT), contraction time (tC), half-relaxation time (tR, 1/2), average rate of force development (DT tC-1) and peak rate of relaxation (DTdtmin-1). These modifications may be related to different Ca2+ concentration transients in the myoplasm during muscle stimulation.

Length-dependent potentiation and myosin light chain phosphorylation in rat gastrocnemius muscle.

Changes in muscle length affect the degree of staircase potentiation in skeletal muscle, but the mechanism by which this occurs is unknown. In this study, we tested the hypothesis that length-dependent change in staircase is modulated by phosphorylation of the myosin regulatory light chains (RLC), since this is believed to be the main mechanism of potentiation. In situ isometric contractile responses of rat gastrocnemius muscle during 10 s of repetitive stimulation at 10 Hz were analyzed at optimal length (Lo), Lo - 10%, and Lo + 10%.

Absence of myosin light chain phosphorylation and twitch potentiation in atrophied skeletal muscle.

Staircase potentiation does not occur in atrophied rat gastrocnemius muscle subjected to repetitive stimulation. Since twitch potentiation is strongly correlated with phosphorylation of the regulatory light chains (R-LC) of myosin, our purpose was to determine if R-LC phosphorylation with repetitive stimulation is also diminished in atrophied gastrocnemius muscle. Following 2 weeks of disuse, induced by delivery of tetrodotoxin (TTX) to the sciatic nerve, phosphorylation and twitch developed tension were measured at 10 s of 10-Hz stimulation in situ in control, sham, and TTX-treated rats.

Myosin light chain phosphorylation and posttetanic potentiation in fatigued skeletal muscle.

Myosin light chain (P-LC) phosphorylation, which is thought to be the principle mechanism for twitch potentiation in skeletal muscle, is significantly decreased during staircase in fatigued muscle. Attenuated phosphorylation of P-LC could be due to either depressed Ca2+ transients in fatigue, or to some inhibitory influence of contractile activity on myosin light chain kinase (MLCK). Tetanic stimulation, which would presumably result in maximal activation of MLCK, could be used to evaluate these potential mechanisms.