Stimulation In Healthy Subjects Research Articles

PS-15-9 Inter-hemispheric asymmetries of somatosensory evoked magnetic fields to median nerve and fingers stimulation in healthy subjects and following hemispheric lesions

PS-15-9 Inter-hemispheric asymmetries of somatosensory evoked magnetic fields to median nerve and fingers stimulation in healthy subjects and following hemispheric lesions

Pain threshold changes by skin vibratory stimulation in healthy subjects

The purpose of this research is to evaluate the changes of cutaneous pain threshold induced by vibratory stimuli applied to the skin. The pain threshold was tested by means of electrical stimuli using the method of limits. Both vibratory stimuli (conditioning stimuli) and electrical stimuli (test stimuli) were driven by a computer. The experiments were carried out on the dorsal surface of the second phalanx of the index finger in the dominant hand of 34 healthy subjects (18 males and 16 females). The conditioning stimuli were sinusoidal waves (250 microm peak to peak) at a rate of 30 and 300 Hz. During the experiment (6 min of vibration and 9 min after) the cutaneous temperature of the stimulated area was recorded. Both vibratory rates induced significant increases of the pain threshold but the 30 Hz vibrations were the more effective. After stimulation the pain threshold lowered to a steady value which was higher than before the start of vibrations. Such threshold changes showed no correlation throughout the experiment with changes in skin temperature. We therefore advance the hypothesis that the main factors which modulate the pain threshold are neuronal connections between tactile and pain pathways.

DMI-Induced Growth Hormone Stimulation in Healthy Subjects and Depressed Patients

DMI-Induced Growth Hormone Stimulation in Healthy Subjects and Depressed Patients

Correlation Between Pancreatic Enzyme Secretion and Plasma Concentration of Human Pancreatic Polypeptide in Health and in Chronic Pancreatitis

We have determined the relationship between pancreatic enzyme secretion and release of pancreatic polypeptide in response to nutrient and hormone stimulation in healthy subjects and in patients with different degrees of chronic pancreatitis. In 8 healthy subjects, the output of trypsin, in response to intraduodenal perfusion of an essential amino acid mixture (39.6 ± 3U/h) was significantly higher than that in response to oleic acid (30. 5 ± 1.6 U/h), which in turn was greater than the response to glucose (11.3 ± 2.3 U/h). The relative potencies of the three nutrients in the stimulation of pancreatic polypeptide secretion were similar to those observed for pancreatic enzyme secretion. The integrated pancreatic polypeptide responses were 3206 ± 317, 1954 ± 147, and 1236 ± 117 pg/min · ml for amino acids, oleic acid, and glucose, respectively. The mean (±SE) increase in trypsin output in response to cholecystokinin octapeptide stimulation (35.6 ± 6.4 U/h), was significantly greater than that observed in response to either secretin (9.4 ± 3.0 U/h), or pentagastrin stimulation (10.2 ± 5.9 U/h). The patterns of pancreatic polypeptide responses were similar to those observed for pancreatic trypsin secretion (integrated plasma pancreatic polypeptide response=3127 ± 722; 1261 ± 488; 1207 ± 383 pg/min · ml for cholecystokinin octapeptide, secretin, and pentagastrin, respectively). Over the range of pancreatic enzyme secretion there was a linear relationship between the mean increase in trypsin output in response to each nutrient and the corresponding integrated plasma pancreatic polypeptide response (r = 0.83, p