The effect of noradrenaline, angiotensin II and vasopressin on blood flow and sensitivity to heat in capsaicin-treated skin.

The effect of iontophoretically applied noradrenaline, angiotensin II and vasopressin on blood flow and sensitivity to heat was investigated in the capsaicin-treated forearms of 52 healthy volunteers. Non-specific effects of a 4-min saline iontophoresis were investigated in another 19 subjects. Pretreatment with phentolamine inhibited vasoconstriction and thermal hyperalgesia to noradrenaline, indicating that alpha-adrenoceptors mediated these responses.

Olfaction in migraine.

Olfactory thresholds for acetone and vanillin and the unpleasantness rating of concentrated acetone were measured in 20 migraine sufferers and 21 controls. The olfactory threshold for vanillin was lower in migraine sufferers than in controls. In addition, patients who reported that odours frequently seemed stronger during attacks of migraine were able to detect acetone at a lower concentration than most other patients.

Photophobia and autonomic responses to facial pain in migraine.

Subjective and autonomic responses to visual stimulation and facial pain were investigated in 10 migraine sufferers and 21 'non-headache' control subjects. Ratings of glare- and light-induced pain were greater in migraine sufferers than control subjects. In migraine sufferers, glare ratings increased during painful mechanical stimulation of the nasal ala, the side of the nose and the back of the neck.

Increased psychosocial stress and decreased mucosal immunity in children with recurrent upper respiratory tract infections.

The association between psychosocial stress and susceptibility to upper respiratory tract infection was investigated in 45 children with a history of recurrent colds and flu, and in 45 healthy children of similar age and distribution. In addition, mucosal immune protection against upper respiratory tract infections was assessed by measuring the concentration of secretory immunoglobulin A (sIgA) and its ratio to albumin in saliva. Several dimensions of psychosocial stress, including exposure to stressful experiences, stress-prone personality traits, and signs of emotional disturbance were elevated in children with a history of recurrent colds and flu.

The reliability and validity of empirically scaled measures of psychological/verbal control and physical/sexual abuse: relationship between current negative mood and a history of abuse independent of other negative life events.

A history of psychological, physical, and sexual abuse, and circumscribed negative life events are precursors of current psychosomatic symptomatology. However, it is not known whether a history of abuse predicts current symptomatology, independent of other negative life events. We developed three new abuse scales: Psychological/Verbal; Control; and Physical/Sexual, which emerged when survey evidence of a random sample of the general public (N = 195) was factor analyzed.

A cognitive behavioural approach to preventing anxiety during magnetic resonance imaging.

This study evaluated a relaxation intervention designed to prevent anxiety during magnetic resonance imaging (MRI), and assessed the development of fears in patients who felt anxious during the procedure. Patients were assigned to a control condition (no intervention; n = 52), relaxation before the scan (n = 44), or relaxation before and during the scan (n = 43). Compared to the control group, patients who practised relaxation showed reduced anxiety during the scan.

Direct measurement of pulse distortion near the zero-dispersion wavelength in an optical fiber by frequency-resolved optical gating.

The technique of frequency-resolved optical gating is used to characterize the intensity and the phase of picosecond pulses after propagation through 700 m of fiber at close to the zero-dispersion wavelength. Using the frequency-resolved optical gating technique, we directly measure the severe temporal distortion resulting from the interplay between self-phase modulation and higher-order dispersion in this regime. The measured intensity and phase of the pulses after propagation are found to be in good agreement with the predictions of numerical simulations with the nonlinear Schrödinger equation.

The effect of adrenergic blockade on blushing and facial flushing.

The effect of adrenergic blockade on vascular responses in the forehead was assessed during stressful mental arithmetic, singing, and moderate exercise in 21 frequent blushers and 21 infrequent blushers. Adrenergic antagonists were introduced into a small site on the forehead by iontophoresis, and vascular responses were monitored bilaterally with laser Doppler flowmetry. Beta blockade prevented increases in blood flow in infrequent blushers during mental arithmetic and partially inhibited vasodilatation during singing, indicating minor participation of beta-adrenoceptors in blushing.

Secretory immunoglobulin A increases during relaxation in children with and without recurrent upper respiratory tract infections.

A diminished mucosal concentration of secretory immunoglobulin A (sIgA) in the upper respiratory tract may increase susceptibility to colds and flu. The aim of the present study was to determine whether sIgA increases during relaxation in children aged between 8 and 12 years with recurrent upper respiratory tract infections. Forty-five healthy children and 45 children with 10 or more upper respiratory tract infections in the previous year were randomly assigned to one of three experimental conditions: relaxation with suggestions to increase immune system proteins, relaxation alone, or a control condition.

Independent effects of ischaemia and noradrenaline on thermal hyperalgesia in capsaicin-treated skin.

Noradrenaline increases thermal hyperalgesia in skin previously sensitized by capsaicin. The aim of the present study was to determine whether a vasoconstrictor ischaemic effect of noradrenaline increases thermal hyperalgesia. Heat pain thresholds were measured in the capsaicin-treated and untreated skin on the forearms of 13 normal volunteers.

Innervation of hyperalgesic skin in patients with complex regional pain syndrome.

Objective: To look for anatomical and histochemical signs of interaction between sensory and sympathetic nerves in the hyperalgesic skin of patients with complex regional pain syndrome.

Subjects: Skin samples were obtained from eight patients whose condition developed after a suspected or confirmed peripheral nerve injury, and from nine patients with features of reflex sympathetic dystrophy (RSD) following a soft-tissue injury. A skin sample was also obtained from 18 control subjects of similar age and sex distribution to patients.

alpha 1-adrenoceptors in normal and hyperalgesic human skin.

1. Evidence of an adrenergic component of cutaneous hyperalgesia has recently been obtained in animal models of painful peripheral neuropathy. These findings have prompted speculation that an increased density or sensitivity of peripheral alpha-adrenoceptors contributes to sensory abnormalities and chronic neuropathic pain in conditions such as reflex sympathetic dystrophy.

Adrenergic receptors in the forehead microcirculation.

The presence of alpha- and beta-adrenoceptors in the forehead microcirculation was investigated in 49 healthy subjects. Local vascular responses to noradrenaline, isoprenaline and adrenergic antagonists, administered transcutaneously by iontophoresis, were monitored via laser Doppler flowmetry. Iontophoresis of the alpha-adrenergic antagonist phentolamine induced a persistent increase in skin blood flow, whereas iontophoresis of saline induced a minor increase in skin blood flow which subsided rapidly.

The site of sympathetic deficit in cluster headache.

The pattern of autonomic deficit in the face of cluster headache patients resembles the deficit in patients with a postganglionic sympathetic lesion from some other cause; however, the presence of abnormal cardiac rhythms and bilateral pupillary reflex deficit in some patients with cluster headache suggests that the lesion might compromise central sympathetic drive. To investigate this possibility, the vasomotor and sudomotor startle reflex was investigated in the hands of six cluster headache patients with ocular and thermoregulatory signs of postganglionic sympathetic deficit in the face; for comparison, responses were also investigated in 15 patients with a lesion in the cervical sympathetic pathway from some other cause. The startle reflex was intact in the hands of the six cluster headache patients, but was diminished ipsilaterally in patients with a central or preganglionic sympathetic lesion and also, surprisingly, in patients with a postganglionic lesion caused by an aneurysm of the internal carotid artery.

Lacrimation induced by thermal stress in patients with a facial nerve lesion.

I measured facial sweating, flushing, and lacrimation during body heating in 10 patients with a facial nerve lesion compromising parasympathetic outflow. During heating, moisture accumulated in the symptomatic eye of patients with facial nerve palsy, particularly in patients with a long-standing lesion. Sweating and flushing in the forehead were symmetrical.

Mechanisms of physiological gustatory sweating and flushing in the face.

Mechanisms of physiological gustatory sweating and flushing were investigated in 21 patients with a facial nerve lesion compromising parasympathetic outflow to the lacrimal gland, and in 13 patients undergoing diagnostic blockade of the stellate ganglion. Vascular responses and electrodermal activity (which reflects sweating) were monitored on each side of the forehead before and during gustatory stimulation with chillies or Tabasco sauce (derived from chillies). Vascular responses in the cheeks were also monitored in 14 patients with a facial nerve lesion.

Noradrenaline increases hyperalgesia to heat in skin sensitized by capsaicin.

Neurophysiological and behavioural observations in animals suggest that sympathetic neural activity and noradrenaline have an excitatory effect on nociceptor discharge in inflamed skin. To determine whether noradrenaline influences pain sensations in humans, heat hyperalgesia in forearm skin sensitized by topical application of 0.6% capsaicin was measured at sites of noradrenaline or saline ionophoresis in 10 healthy subjects.

Lacrimation and cutaneous vasodilatation in the face induced by painful stimulation of the nasal ala and upper lip.

The effect of painful stimulation of the nasal ala and upper lip on lacrimation and cutaneous vascular responses in the forehead and cheeks was investigated in 11 normal subjects. In addition, the mechanism of the response was studied in 10 patients with a lesion compromising parasympathetic activity in the facial nerve. In normal subjects, pinching the nasal ala with forceps increased blood flow on the ipsilateral side of the forehead but not the cheek.

Effect of imagining and actually tasting a sour taste on one side of the tongue.

To determine whether images can stimulate brainstem reflexes directly, parotid salivation was measured bilaterally in 24 subjects when they imagined, and actually tasted, a sour taste on one side of the tongue. Salivation increased in both cheeks during unilateral gustatory stimulation; furthermore, the response was greater on the stimulated side than contralaterally, indicating that the gustatory reflex has a unilateral component. Subjects imagined the sour taste more clearly after actually experiencing it.