Capsaicin desensitization in vivo is inhibited by ruthenium red.

The effect of systemic administration of Ruthenium Red on the excitatory and desensitizing effect of capsaicin was investigated in rats. Ruthenium Red was injected s.c. 30 min before capsaicin was administered. The excitatory effect of capsaicin on corneal, perivascular and visceral afferents was not influenced by treatment with Ruthenium Red. However, determination of the neuropeptide content and evoked neuropeptide release in peripheral organs and dorsal spinal cord 48 h after treatment showed that Ruthenium Red attenuated the 'desensitizing' effect of capsaicin at peripheral, but not at central, endings of primary afferents. On the other hand, a capsaicin-elicited autonomic reflex mediated by visceral afferents was still obtained in 9 of 14 rats that had received Ruthenium Red and capsaicin. The results indicate that a single dose of Ruthenium Red, which does not reduce the acute excitatory effect of capsaicin, reduces the desensitizing effect of capsaicin on peripheral endings of primary afferents in vivo. This long-lasting protective effect of Ruthenium Red suggests that it is possible to pharmacologically differentiate between the acute and chronic effects of capsaicin.     

The effect of major railway accidents on the psychological health of train drivers—I. Acute psychological responses to accident

The acute psychological reactions of 101 train drivers to on-the-track accidents were studied by means of clinical interviews and questionnaires (Impact of Event Scale, GHQ-20 and a questionnaire addressing stress symptoms, pre-accident expectancies and worries). More than half of the train drivers reported moderate to high intrusive distress (mean 11.3) within hours to days after the accident but only 1/3 reported symptoms of acute psychophysiological arousal. Intrusive symptoms related to visual impressions were most frequently reported. Avoidance was less prevalent (mean 8.8).

Clinical interviews, relationship between pre-accident worries and severity of the acute responses and positive correlation between GHQ-scores relating to the fortnight preceding the accident and IES-intrusion scores, suggest that premorbid variables may influence the stress response. Involvement in more than two previous accidents invoked a feeling of vulnerability and produced stronger acute responses. Post-accident experiences involving various personal contacts did not correlate with the stress responses in this study and only a few drivers experienced such events in a negative way. Denial of the possibility of being involved in accidents was not associated with increased risk of strong acute responses, indicating that denial does not predict poor outcome in healthy persons exposed to situations where possibility of avoiding the event is outside the control of the person.     

Neurogenic and non-neurogenic inflammation in the rat paw following chemical sympathectomy.

Rats with chemical sympathectomy, induced either at neonatal age (long-term sympathectomy) or in adult animals (short-term sympathectomy) by guanethidine or by 6-hydroxydopamine, were used to determine the contribution of sympathetic noradrenergic fibres to afferent neuron-mediated responses and to non-neurogenic inflammation in the rat. Following long-term sympathectomy with 6-hydroxydopamine there was a 66% depletion of noradrenaline in the paw skin. This was accompanied by a 20-53% increase in the levels of sensory neuropeptides in the paw skin and sciatic nerve. A hypersensitivity towards heat stimuli was observed in the tail immersion test. Neither neurogenic plasma protein extravasation following antidromic nerve stimulation or upon local mustard oil application nor the development of the non-neurogenic carrageenan oedema and its susceptibility towards indomethacin were impaired. Neonatal guanethidine sympathectomy caused an 86% depletion of noradrenaline in the paw skin and neurogenic plasma protein extravasation upon antidromic nerve stimulation was impaired. Sensory neuropeptides were unchanged in the skin after neonatal guanethidine and only calcitonin gene-related peptide content was increased in the spinal cord and sciatic nerves. The other observations (i.e. the sensitivity towards heat stimuli, the neurogenic mustard oil inflammation and the non-neurogenic carrageenan oedema) were similar to those observed after neonatal 6-hydroxydopamine treatment. Following the short-term treatment protocol of 6-hydroxydopamine, an 82% depletion of noradrenaline in the skin was accompanied by an increase in calcitonin gene-related peptide content, whereas after adult guanethidine (60% depletion of noradrenaline) levels of sensory neuropeptides were unchanged. Neurogenic plasma protein extravasation was found to be unimpaired after either type of short-term chemical sympathectomy.(ABSTRACT TRUNCATED AT 250 WORDS)     

Why is coronary heart disease of uraemic patients so frequent and so devastating?

On September 6, 2001, Professor Fernando Valderrabano (Hospital Gregorio Mara?on, Madrid) died at the age of 59 years. He was a leading figure in Spanish nephrology, a full professor of Medicine/Nephrology at the University Complutense of Madrid, and an outstanding scientist who published more than 300 articles in medical journals. He was a very intelligent and cultured person, and a man of great style who enjoyed a wide range of hobbies and interests in addition to his medical work. All his colleagues and friends mourn his passing.     

The meaning of work after acquired brain injury.

PURPOSE: Research in the field of brain injury rehabilitation has tended to regard return to work as a measure of outcome. Researchers have not paid particular attention to the experiences of people living with a brain injury. The aim of the phenomenological study reported here was to identify and describe what characterizes the meaning of work to those with acquired brain injury. METHODS: Ten participants of working age were interviewed about the meaning of work 1-5 years after being inflicted with a brain injury. Data were analyzed and interpreted using the Empirical Phenomenological Psychological method. RESULTS: The findings revealed a meaning structure consisting of four main characteristics. Work was no longer experienced as the primary event in life and the social dimension had become more important. The perceived competence and work identity were threatened after the injury. A common theme across all interviews was the struggle to return to a state of normality, and working was considered to be evidence of success. CONCLUSION: The findings described the altered meaning of work 1-5 years after brain injury. This knowledge should lead to an increased understanding among occupational therapists engaged in work rehabilitation after brain injury and can serve as a basis for individualized intervention strategies.