137 resultados para Exposure Treatment
Resumo:
Our aim was to determine whether antenatal corticosteroids improve perinatal adaptation of the pulmonary circulation in lambs with lung hypoplasia (LH). LH was induced in 12 ovine fetuses between 105 and 140 days gestation (term similar to 147 days); in 6 of these the ewe was given a single dose of betamethasone (11.4 mg im) 24 hr before delivery (LH + B). All lambs, including a control group (n = 6), were delivered at similar to 140 days and ventilated for 2 hr during which arterial pressures, pulmonary blood flow (PBF), and ventilating pressure and flow were recorded. During ventilation, respiratory system compliance was lower in both LH + B and LH groups than in controls. Pulmonary vascular resistance (PVR) was lower in LH + B lambs than in LH lambs and similar to controls; PBF was reduced in LH lambs but was restored to control levels by betamethasone. The mean density of small arteries of LH + B lambs was similar to that of LH lambs (P = 0.06) and lower than in controls; the thickness of the media of small pulmonary arteries from LH + B lambs was similar to that in LH lambs and thicker than in controls. VEGF mRNA levels were not different between groups. PDGF mRNA levels in LH + B lambs were higher than in LH lambs; a similar trend (P = 0.06) was seen for PECAM-1. SP-C mRNA levels were greater in both LH and LH + B lambs than in controls. Effects of betamethasone were greater on indices of pulmonary circulation than ventilation. We conclude that a single dose of maternal betamethasone 24 hr prior to birth has significant favorable effects on the postnatal adaptation of the pulmonary circulation in lambs with LH.
Resumo:
The current study aims to ascertain the fate of the melanocyte stimulating hormone (MSH) receptor and its ligand [Nle(4), D-Phe(7)]alpha-MsH (NDP-MSH) following binding to murine B16 melanoma cells. Cells were incubated with [I-125]-NDP-MSH for up to 180 min and binding, internalization and degradation determined. Intracellular trafficking of the radiolabel was assessed !using Percoll density gradient centrifugation of homogenized cells. Receptor down-regulation and receptor mRNA levels were also measured over 96 hr after exposure to 1 mu M ligand. NDP-MSH accumulation increased with time in a temperature-dependent manner and was inhibited by excess peptide. The ligand was rapidly internalized and translocated to the lysosomal compartment where it was degraded. Internalization was accompanied by a loss or down-regulation of cell surface receptors, suggesting internalization of the NDP-MSH-receptor complex. No recycling of the receptors between the plasma membrane and intracellular compartments could be detected in this cell-hue. Approximately 15% of the surface receptors were resistant to down-regulation, possibly indicating receptor heterogeneity. Down-regulation persisted ibr up to 96 hr and was accompanied by a decrease in MSH receptor mRNA levels 48 hr after treatment. However, before this time, transcript levels were the same in treated and control cells. In contrast to what was seen with NDP-MSH, cell surface receptors removed with trypsin wc:re rapidly replaced. These results show that NDP-MSH not only induced MSH receptor :internalization but also inhibited receptor turnover, resulting in a prolonged down-regulation. It is concluded that, in B16 cells, the MSH receptor undergoes ligand-dependent internalization, resulting in a prolonged down-regulation. Copyright (C) 1996 Elsevier Science Ltd
Resumo:
Manipulative therapy is frequently used in the management of musculoskeletal pain. A frequently reported clinical feature of this treatment is the immediacy with which it appears to initiate improvement in pain and function. A randomised, double blind, placebo controlled, repeated measures design was employed to study the initial effects of a cervical spine treatment technique in a group of 15 patients with lateral epicondylalgia. Pressure pain threshold, pain-free grip strength, upper limb neurodynamics, pain and function were assessed prior to and following application of either a treatment, placebo or control condition. All subjects received all three conditions. Differences between the pre-post measures were used as indicators of change in subject's symptom profiles. The treatment condition produced significant improvement in pressure pain threshold, pain-free grip strength, neurodynamics and pain scores relative to placebo and control conditions (P < 0.05). In summary, this study demonstrates that manipulative therapy is capable of eliciting a rapid hypoalgesic effect.
Resumo:
Background. A sample of 1089 Australian adults was selected for the longitudinal component of the Quake Impact Study, a 2-year, four-phase investigation of the psychosocial effects of the 1989 Newcastle earthquake. Of these, 845 (78%) completed a survey 6 months post-disaster as well as one or more of the three follow-up surveys. Methods. The phase I survey was used to construct dimensional indices of self-reported exposure to threat the disruption and also to classify subjects by their membership of five 'at risk' groups (the injured; the displaced; owners of damaged small businesses; helpers in threat and non-threat situations). Psychological morbidity was assessed at each phase using the 12-item General Health Questionnaire (GHQ-12) and the Impact of Event Scale (IES). Results. Psychological morbidity declined over time but tended to stabilize at about 12 months post-disaster for general morbidity (GHQ-12) and at about 18 months for trauma-related (IES) morbidity. Initial exposure to threat and/or disruption were significant predictors of psychological morbidity throughout the study and had superior predictive power to membership of the targeted 'at risk' groups. The degree of ongoing disruption and other life events since the earthquake were also significant predictors of morbidity. The injured reported the highest levels of distress, but there was a relative absence of morbidity among the helpers. Conclusions. Future disaster research should carefully assess the threat and disruption experiences of the survivors at the time of the event and monitor ongoing disruptions in the aftermath in order to target interventions more effectively.
Resumo:
Outcomes of treatment of musculoskeletal tumours are evaluated for effectiveness of chemotherapy protocols, function obtained after surgery and survival after treatment. Quality of life achieved after multi-modality treatment is dependent on a combination of all of these factors. Quality of life varies significantly along the treatment pathway, and continuously through the life of a patient. The patient's perception of outcome is based on the total effect of the disease and its treatment, rather than necessarily focussing on separate items of treatment. We have found that visual analogue scales can be used effectively to gauge the patient's perception of their quality of life. Such a method has shown that, overall, perceptions of quality of life seem to be better for those patients who have undergone successful limb salvage surgery when compared with those who have undergone amputation, but the differences are not as great as might be assumed.
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Extraction of intracellular protein from Escherichia coli is traditionally achieved by mechanical disruption. A chemical treatment that destroys the integrity of the bacterial cell wall and could provide an alternative technique is examined in this study. Treatment with a combination of the chelating agent ethylenediaminetetraacetate (EDTA) (greater than 0.3 mM) and the chaotropic agent urea (6 M) is highly effective at releasing protein from uninduced E. coli. The 6 M urea in the presence of 3 mM EDTA can release cytoplasmic protein from both logarithmic-phase and stationary-phase E. coli cells at levels equivalent to mechanical disruption. The concentrations of the two chemical agents were the major variables affecting the maximum levels of protein release. Several minor variables and interactions were also identified. The kinetics of protein release is first order. For 2, 4, and 6 M urea with 3 mM EDTA, the time constant is approximately 2.5 min independent of urea concentration. Kinetics for 3 mM EDTA without urea is considerably slower, with a time constant of 12.3 min. (C) 1997 John Wiley & Sons, Inc.
Resumo:
It has been claimed that the symptoms of post-traumatic stress disorder (PTSD) can be ameliorated by eye-movement desensitization-reprocessing therapy (EMD-R), a procedure that involves the individual making saccadic eye-movements while imagining the traumatic event. We hypothesized that these eye-movements reduce the vividness of distressing images by disrupting the function of the visuospatial sketchpad (VSSP) of working memory, and that by doing so they reduce the intensity of the emotion associated with the image. This hypothesis was tested by asking non-PTSD participants to form images of neutral and negative pictures under dual task conditions. Their images were less vivid with concurrent eye-movements and with a concurrent spatial tapping task that did not involve eye-movements. In the first three experiments, these secondary tasks did not consistently affect participants' emotional responses to the images. However, Expt 4 used personal recollections as stimuli for the imagery task, and demonstrated a significant reduction in emotional response under the same dual task conditions. These results suggest that, if EMD-R works, it does so by reducing the vividness and emotiveness of traumatic images via the VSSP of working memory. Other visuospatial tasks may also be of therapeutic value.
Resumo:
Systemic injection of kainic acid (KA) results in characteristic behaviors and programmed cell death in some regions of the rat brain. We used KA followed by recovery at 4 degrees C to restrict damage to limbic structures and compared patterns of immediate early gene (IEG) expression and associated DNA binding activity in these damaged areas with that in spared brain regions. Male Wistar rats were injected with BA (12 mg/kg, ip) and kept at 4 degrees C for 5 h. This treatment reduced the severity of behaviors and restricted damage (observed by Nissl staining) to the CA1 and CA3 regions of the hippocampus and an area including the entorhinal cortex. DNA laddering, characteristic of apoptosis, was first evident in the hippocampus and the entorhinal cortex 18 and 22 h after RA, respectively. The pattern of IEG mRNA induction fell into three classes: IEGs that were induced in both damaged and spared areas (c-fos, fos B, jun B, and egr-1), IEGs that were induced specifically in the damaged areas (fra-2 and c-jun), and an IEG that was significantly induced by saline injection and/or the cold treatment (jun D). The pattern of immunoreactivity closely followed that of mRNA expression. Binding to the AP-1 and EGR DNA consensus sequences increased in all three regions studied. This study describes a unique modification of the animal model of ICA-induced neurotoxicity which may prove a useful tool for dissecting the molecular cascade that ultimately results in programmed cell death. (C) 1997 Academic Press.
Resumo:
This article discusses the ethical justification for and reviews the American evidence on the effectiveness of; treatment for alcohol and heroin dependence that is provided under legal coercion to offenders whose alcohol and drug dependence has contributed to the commission of the offence with which they have been charged or convicted. The article focuses on legally coerced treatment for drink-driving offenders and heroin-dependent property offenders. it outlines the various arguments that have been made for providing such treatment under legal coercion, namely. the over-representation of alcohol and drug dependent persons in prison populations; the contributory causal role of alcohol and other drug problems in the offences that lead to their imprisonment; the high rates of relapse to drug use and criminal involvement after incarceration; the desirability of keeping injecting heroin users out of prisons as a way of reducing the transmission of infectious diseases such as HIV and hepatitis; and the putatively greater cost-effectiveness of treatment compared with incarceration. The ethical objections to legally coerced drug treatment are briefly discussed before the evidence on the effectiveness of legally coerced treatment for alcohol and other drug dependence is reviewed. The evidence, which is primarily from the USA, gives qualified support for some forms of legally coerced drug treatment provided that these programs are well resourced, carefully implemented, and their performance is monitored to ensure that they provide a humane and effective alternative to imprisonment. Expectations about what these programs can achieve also need to be realistic.
Resumo:
Rats exposed to a relatively high dose (7.5 g/kg body weight) of alcohol on either the fifth or tenth postnatal day of age have been reported to have long-lasting deficits in spatial learning ability as tested on the Morris water maze task. The question arises concerning the level of alcohol required to achieve this effect. Wistar rats were exposed to either 2, 4 or 6 g/kg body weight of ethanol administered as a 10% solution. This ethanol was given over an 8-h period on the fifth postnatal day of age by means of an intragastric cannula. Gastrostomy controls received a 5% sucrose solution substituted isocalorically for the ethanol. Another set of pups raised by their mother were used as suckle controls. All surgical procedures were carried out under halothane vapour anaesthesia. After the artificial feeding regimes all pups were returned to lactating dams and weaned at 21 days of age. The spatial learning ability of these rats was tested in the Morris water maze when they were between 61-64 days of age. This task requires the rats to swim in a pool containing water made opaque and locate and climb onto a submerged platform. The time taken to accomplish this is known as the escape latency. Each rat was subjected to 24 trials over 3 days of the test period. Statistical analysis of the escape latency data revealed that the rats given 6 g/kg body weight of ethanol had significant deficits in their spatial learning ability compared with their control groups. However, there was no significant difference in spatial learning ability for the rats given either 2 or 4 g/kg body weight of ethanol compared with their respective gastrostomy or suckle control animals. We concluded that ethanol exposure greater than 4 g/kg over an 8-h period to 5-day-old rats is required for them to develop long-term deficits in spatial learning behaviour. (C) 1998 Elsevier Science Inc.