Metastatic carcinoid tumor imaged with CT and a radiolabeled somatostatin analog: a case report

Radiolabeled somatostatin analogs have shown uptake in a variety of tumors. These include carcinoid, Merkel cell carcinoma, pheochromocytoma, islet cell tumor, and other tumors with somatostatin receptors. Radiolabeled somatostatin analog imaging with Indium-111-DTPA-pentetreotide permits whole body imaging, providing a new safe and effective means for detection of primary tumors and metastatic foci in neoplasms with somatostatin receptors. This imaging modality is helpful in screening the entire body as well as evaluating questionable foci of disease identified by conventional imaging modalities. This case report demonstrates the utility of computed tomography (CT) and radiolabeled somatostatin imaging as complementary modalities in the workup of a patient with metastatic carcinoid tumor.

Comparison of the clinical abrasion resistance of six commercially available denture teeth

PURPOSE

Clinical abrasion of denture teeth has certain implications when dentures are worn in excess of the average useful lifetime. The purpose of this study was to evaluate clinical denture tooth wear over a period of 3 years.

MATERIAL AND METHODS

The wear of six commercially available denture teeth (Premierdent, Acrotone, vitapan, Rx1, Duravite, and Ivoclar Orthosit) and a seventh combination of teeth was compared. Seventy patients with complete dentures were divided into seven groups of 10 each to form the study population.

RESULTS

There were no significant differences among the commercial denture teeth. Porcelain/Vitapan teeth exhibited the highest amount of abrasion. Significant wear was also measured between the Ivoclar Orthosit and Porcelain/Vitapan teeth.

Observations of the low Earth orbit radiation environment from Mir

Recent measurements of the high-energy charged particle environment with the Radiation Environment Monitor (REM) aboard the Russian Mir space station are presented. Ionizing dose rates in a silicon detector have been measured with two shieldings. The dose is mainly accumulated in two distinct areas, the South Atlantic Anomaly (SAA) and the region of closest approach to the magnetic poles. Whereas the radiation in the South Atlantic Anomaly varied little during 1995, large changes of the daily absorbed doses in the polar regions are observed. A comparison of REM doses with the NASA AP-8 and AE-8 radiation models revealed major differences. AP-8 tends to underestimate the average REM doses, whereas AE-8 overestimates REM doses, and rather describes the worst case.

Human cerebral activity with increasing inspiratory force: a study using positron emission tomography

Human cerebral activity with increasing inspiratory force: a study using positron emission tomography. J. Appl. Physiol. 81(3): 1295-1305, 1996.--The major aim of this study was to use positron emission tomography (PET) to assess dose-dependent effects of inspiratory loads on relative regional cerebral blood flow as an indication of neuronal activation and recruitment. Six normal men underwent H2 15O-PET scanning during unloaded breathing and with external inspiratory loads (generating mouth pressures of -5, -10, and -15 cmH2O); positive-pressure ventilation against relaxed respiratory muscles acted as control. During unloaded breathing, the supplementary motor area was significantly activated. With the addition of the smallest load, activations also occurred in the right premotor area and bilaterally in the superolateral motor cortex (MI) in areas previously shown to be activated with deeper breathing. There was little further change in these areas with greater loads. Additional force-related activations occurred in the inferolateral sensorimotor cortex, parietal cortex, and midbrain/hypothalamus. The results suggest that volitionally induced increases in inspiratory muscle force are achieved via a complex integration of neuronal activations in cortical and subcortical regions associated with motor control.

Breathing during wakefulness and NREM sleep in humans without an upper airway

The increase in PCO2 that occurs during sleep may reflect an inadequate ventilatory compensation to an increase in upper airway resistance. To address this question in humans, we examined changes in breathing during wakefulness and non-rapid-eye-movement sleep in eight laryngectomized subjects who breathed through a tracheal stoma. In these subjects, any sleep-related increase in upper airway resistance could not affect ventilation. Healthy subjects breathing via an intact upper airway were studied as controls. The mean increase in end-tidal PCO2 from wakefulness to sleep was 2.7 +/- 2.6 (SD) Torr (P = 0.05) in laryngectomized subjects and 1.6 +/- 1.4 Torr (P = 0.02) in control subjects. During wakefulness, ventilation was lower in laryngectomized subjects compared with control subjects, although this difference was not statistically significant (6.8 +/- 1.9 vs. 7.4 +/- 1.2 l/min; P > 0.05). During sleep, the fall in ventilation was similar in the two groups (1.1 +/- 2.1 vs. 0.8 +/- 2.1 l/min; P > 0.05). Our observations are not consistent with the view that increases in upper airway resistance are obligatory for sleep-related CO2 retention in humans.

Biphasic modulation of cell growth by recombinant human galectin-1

Human soluble galactose-binding lectin (galectin-1) has been expressed as an Escherichia coli fusion protein, following the amplification by polymerase chain reaction of cDNA prepared from a human osteosarcoma cell line. The fusion protein is a functional beta-galactoside-binding lectin, as is the recombinant galectin when purified from the cleaved fusion protein. The recombinant galectin has a biphasic effect on cell proliferation. Unlike the fusion protein, it functions as a human cell growth inhibitor, confirming earlier findings with natural human galectin-1, though it is less effective than the natural galectin. This reaction is not significantly inhibited by lactose, and is thus largely independent of the beta-galactoside-binding site. At lower concentrations, recombinant galectin-1 is mitogenic, this activity being susceptible to inhibition by lactose, and thus attributable to the beta-galactoside-binding ability of the protein. Some tumour cells are susceptible to the growth-inhibitory effect, and the galectin-1 gene is expressed in both normal and tumour cells.

Does oxygen help dyspnea in patients with cancer?

Dyspnea in patients with advanced cancer is a common symptom that is difficult to treat. This study investigated whether oxygen helps to relieve rest dyspnea in patients with advanced cancer. In a single-blind controlled trial, oxygen and air were administered in random order to hospice patients reporting dyspnea at rest. Measurements of arterial oxygen saturation, lung function, and dyspnea (using a visual analogue scale [VAS] and Borg score) were made before and after each gas had been given for 15 min. Data from 38 patients were used: analysis of variance revealed that mean VAS levels during baseline conditions, breathing room air (59 mm), were significantly reduced after administration of either air (48 mm; p < 0.001) or oxygen (45 mm; p < 0.001); there was no significant difference for the mean VAS scores between oxygen and air administration. There was no statistically significant order of treatment effect. There was no difference in the response to oxygen or air in patients with a history of cardiopulmonary disease. The improvement in dyspnea with oxygen could not be predicted from a subject's initial level of hypoxia. Results suggested that benzodiazepines may potentiate the effect of oxygen. The overall conclusion is that oxygen and air can have a significant effect in reducing dyspnea at rest in patients with advanced cancer.

Pre-clamp cardioprotection by protein kinase C (PKC) inhibitor improves left ventricular function following canine normothermic arrest

Since protein kinase C (PKC) has been proven to be a mediator of neutrophil activation and of intracellular calcium homeostasis, its inhibition could protect the myocardium from the deleterious effects of ischemic/reperfusion inury (IRI). The principal objective of this study was to evaluate the efficacy of the PK inhibitor SPC-100270 (2S,3S)-2-amino, 3-octadecanediol in a canine model of IRI. A double-blind study was conducted in which 19 coonhound dogs received either SPC-100270 or a vehicle before going on cardiopulmonary bypass (CPB). After 60 minutes of global normothermic (37 degree C) cardiac arrest (cross-clamp time 65-81 minutes for SPC-100270 and 65-72 minutes for control) and discontinuation of CBP, an epicardial short axis view echocardiogram was performed and reviewed by a double-blinded observer to determine the ejection fraction (EF). EF value exceeded 20% in 5 out of 9 SPC-100270 animals (27%-44%) and in 0 of 10 controls (0%-16%). These data show that SPC-10027 significantly (p=0.01 by Fisher's Exact Test) increased the probability that the animals would exhibit an EF greater than 20%.

Ventilatory relief of the sensation of the urge to breathe in humans: are pulmonary receptors important?

1. The sensation of an urge to breathe (air hunger) associated with a fixed level of hypercapnia is reduced when ventilation increases. The aim of the present study was to investigate whether pulmonary receptors are important in this mechanism. 2. Five heart-lung transplant (HLT) subjects and five control subjects were studied during periods of mechanical and spontaneous ventilation. End-tidal Pco2 (PET,CO2) was increased by altering the level of inspired CO2. Throughout, subjects rated sensations of air hunger. Air hunger was also monitored during and immediately following maximal periods of breath-holding. 3. When the level of mechanical ventilation was fixed, both groups experienced a high degree of air hunger when PET,CO2 was increased by about 10 mmHg. At similar levels of hypercapnia, both groups derived relief from approximately twofold increases in tidal volume, although relief was slightly less effective in HLT subjects. This was reversible, with decreases in the level of mechanical ventilation rapidly giving rise to increased ratings of air hunger. 4. With breath-holding, all subjects obtained some respiratory relief within 2 s of the break point; there was no significant difference between the groups. 5. The results suggest that sensations of an urge to breathe induced by hypercapnia can be modulated by changes in tidal volume in the presumed absence of afferent information from the lung.

GIP regulates glucose transporters, hexokinases, and glucose-induced insulin secretion in RIN 1046-38 cells

Acute studies of glucose-dependent insulinotropic peptide (GIP) have shown that GIP can synergize with glucose in stimulating insulin secretion both in vivo and in vitro. Here we studied the effects of extended exposure of RIN 1046-38 cells, an insulin-secreting cell line, to GIP and the mechanisms by which GIP synergizes with glucose in stimulating insulin secretion. Incubation of the cells with 100 nM GIP in the presence of glucose for 12 h significantly increased insulin release (287 +/- 31.7 vs. 102 +/- 9.7 ng/mg protein; n = 3), intracellular insulin content (12.8 +/- 0.83 vs. 8.2 +/- 0.52 ng/mg protein; n = 3), and insulin mRNA (approximately 2.7-fold; 24 h incubation) when compared to cells cultured with glucose alone. The insulinotropic effects of GIP on RIN 1046-38 cells were accompanied by an up-regulation of GLUT-1 and hexokinase I mRNA (1.75-fold) compared to non-GIP-treated cells; mRNA levels of GLUT-2 and glucokinase were unchanged by GIP, in the presence or absence of glucose. Our study suggests that the mechanism by which extended exposure of RIN 1046-38 cells to GIP increases glucose-stimulated insulin secretion includes up-regulation of glucose sensing elements.

Hyperpnoea during and immediately after exercise in man: evidence of motor cortical involvement

1. The neurophysiological basis for the increase in breathing associated with exercise remains obscure. The present study uses positron emission tomography (PET) to measure relative regional cerebral blood flow (rCBF) in order to identify sites of increased neuronal activation during and immediately following exercise. 2. Male volunteers underwent H2(15)O PET scanning during two complementary studies. Firstly, six subjects performed right leg exercise, adequate to increase oxygen uptake 2.5-fold. Secondly, five different subjects were scanned immediately following bicycle exercise (adequate to increase oxygen uptake 5-fold) while breathing was still increased. In each study, as a control, scanning was also performed during matched passive isocapnic positive pressure ventilation; additionally, in the first study, passive right leg movement was performed. 3. Increases in relative rCBF were obtained in each individual and co-registered with their magnetic resonance image of the brain defining individual gyral morphology. 4. During exercise, individual and group analysis revealed significant relative rCBF increases in the left and right superomedial primary motor cortex (the motor cortical 'leg' areas) and also in the left and right superolateral primary motor cortex in areas previously shown to be associated with volitional breathing. After exercise, there was no significant increase in relative rCBF in the superomedial areas but such increases were still present bilaterally in the superolateral areas which had been activated during the exercise. Other relative rCBF increases were also found, both during and after exercise, in cortical and subcortical areas known to be involved in motor control. 5. The results from PET scans during and after exercise, taken together, provide evidence for motor cortical involvement in the exercise-related hyperpnoea in man.

Adaptation of nicotinic acetylcholine receptor, myogenin, and MRF4 gene expression to long-term muscle denervation

Muscle activity alters the expression of functionally distinct nicotinic acetylcholine receptors (nAChR) via regulation of subunit gene expression. Denervation increases the expression of all subunit genes and promotes the expression of embryonic-type (alpha 2 beta delta gamma) nAChRs, while electrical stimulation of denervated muscle prevents this induction. We have discovered that the denervation-induced increases in alpha, beta, gamma, and delta subunit gene expression do not persist in muscles that have been denervated for periods extending beyond a couple of months. However, expression of RNA encoding the epsilon-subunit remains elevated suggesting a return to expression of predominantly adult-type (alpha 2 beta delta epsilon) nAChR in long-term denervated muscles; a finding confirmed by single channel patch-clamp analysis. Since the nAChR subunit genes are regulated by the MyoD family of muscle regulatory factors, and the genes encoding these factors are also induced following short-term muscle denervation, we determined their level of expression in long-term denervated muscle. Although MyoD and myf-5 RNA levels remained elevated, myogenin and MRF4 RNAs were induced only transiently by muscle denervation. Surprisingly, Id-1, a negative regulator of transcription, was gradually induced in denervated muscle with RNA levels peaking about two months after denervation. It is likely that this maintained level of increased Id expression, in conjunction with the returning levels of myogenin and MRF4 expression, account for the reduced level of embryonic receptors in long-term denervated muscle. These changing patterns of gene expression may have important consequences for the ability of muscle to recover function after denervation.

Modulation by "central" PCO2 of the response to carotid body stimulation in man

We describe a method to assess the effects of PCO2, around and below eucapnia, on the neuromuscular ventilatory response to a standard peripheral chemoreceptor stimulus. Subjects were "passively" hyperventilated (without respiratory muscle activity), at a constant level of ventilation. Stimuli (3-7 breaths N2) were delivered over a range of steady-state PETCO2 (25-43 mmHg). Stimuli during hypocapnia were coupled with a transient increase in FICO2 so that the stimulus to the peripheral chemoreceptors was always "hypoxia at eucapnia". Responses to the stimuli (quantified from the reduction in peak inflation pressure and the magnitude of the evoked diaphragm electromyographic activity) decreased in a graded manner as steady-state PETCO2 fell, disappearing at 7.5 mmHg below eucapnia. Carotid body chemoreceptor recordings from two anaesthetised cats, indicated that the peak firing rate during such stimuli was independent of steady-state PETCO2. The results suggest that the central sensitivity to a peripheral chemoreceptor input may be modulated by changes in steady-state PCO2 around eucapnia and during mild hypocapnia.

Oral efficacy of a leukotriene B4 receptor antagonist in colitic cotton-top tamarins

Leukotriene B4 (LTB4) is a potent neutrophil activator and chemotaxin that is present in increased concentrations in the colonic tissue and rectal dialysates of acute ulcerative colitis patients. Cotton-top tamarins (CTTs) with confirmed active colitis were treated with the second generation LTB4 receptor antagonist, SC-53228 ((+)-(S)-7-[3-(2-cyclopropyl-methyl)-3-methoxy-4-[(methylamino) carbonyl]phenoxy]propoxy]-3,4-dihydro-8-propyl-2H-1-benzopyran-2- propanoic acid), 20 mg/kg bodyweight by gavage, twice daily for 56 days. End points were body weights, stool consistency, colonic endoscopy, assay of inflammatory mediators, and haematology and clinical chemistry tests. LTB4 and prostaglandin E (PGE) values were measured in rectal dialysates at pretreatment, 28 day and 56 day time points. LTB4 concentrations were reduced from pretreatment mean (SEM) values of 37.3 (0.8) ng/ml to 3.7 (0.8) ng/ml (p < 0.001) and 2.3 (0.5) ng/ml (p < 0.01) at days 28 and 56, respectively. On the other hand, mucosal protective PGE values remained constant or slightly increased during SC-53228 treatment (pre: 6.9 (2.2) ng/ml; day 28: 6.7 (1.4) ng/ml; day 56: 9.9 (1.6) ng/ml). Furthermore, assessment of a panel of 35 clinical chemistry and haematology parameters throughout the treatment showed there were no significant untoward effects of drug treatment. Six CCTs finished the eight week treatment and five of six gained weight (ranging from 27-121 grams each) while one CTT lost weight (50 g). Stool condition improved in five of six animals while one of six remained unchanged. All CCTs showed dramatic improvement histologically, with no or only minimally active colitis after treatment. The histological changes plus significant weight gains and improvement of stool condition (quality of life parameters) after eight weeks of SC-53228 treatment were remarkable. Furthermore, in follow up biopsies seven months after treatment ceased, three of six CTTs had no active colitis. This is the first time afflicted CTTs have not had recurring colitic exacerbations after a treatment regimen was stopped. It is concluded that in colitic CTTs, SC-53228 has shown both an immediate and a long acting anticolitic activity. It is also concluded that reduced LTB4 concentrations during treatment inhibited neutrophil infiltration of the colonic tissue and this, coupled with the maintenance of mucosal protective prostaglandins, contributed to the dramatic anticolitic efficacy. The treatment was safe over eight weeks. A compound such as SC-53228 may be useful in the medical treatment of human inflammatory bowel disease.

Evidence for limbic system activation during CO2-stimulated breathing in man

1. The role of supra-brainstem structures in the ventilatory response to inhaled CO2 is unknown. The present study uses positron emission tomography (PET), with infusion of H2(15)O, to measure changes in relative regional cerebral blood flow (rCBF) in order to identify sites of increased neuronal activation during CO2-stimulated breathing (CO2-SB) in awake man. 2. Five male volunteers were scanned during CO2-SB (mean +/- S.E.M.; end-tidal PCO2, 50.3 +/- 1.7 mmHg; respiratory frequency, 16.4 +/- 2.7 min-1; tidal volume, 1.8 +/- 0.2 l). As control, scans were performed during 'passive' isocapnic (elevated fraction of inspired CO2) positive pressure ventilation (end-tidal PCO2, 38.4 +/- 1.0 mmHg; respiratory frequency, 15.5 +/- 2.2 min-1; tidal volume, 1.6 +/- 0.2 l). With CO2-SB, all subjects reported dyspnoea. 3. The anatomical locations of the increases in relative rCBF (CO2-SB versus control) were obtained using magnetic resonance imaging. 4. Group analysis identified neuronal activation within the upper brainstem, midbrain and hypothalamus, thalamus, hippocampus and parahippocampus, fusiform gyrus, cingulate area, insula, frontal cortex, temporo-occipital cortex and parietal cortex. No neuronal activation was seen within the primary motor cortex (at sites previously shown to be associated with volitional breathing). 5. These results suggest neuronal activation within the limbic system; this activation may be important in the sensory and/or motor respiratory responses to hypercapnia in awake man.

How exercise can help people with mental health problems

The researcher describes the outcomes gained by a young man with a diagnosis of chronic schizophrenia who participated in a 12-week progressive exercise programme. Using the Brief Psychiatric Rating Scale and the Nurses Observational Scale for Inpatient Evaluation, the researcher was able to evaluate any changes in the patient. There were significant changes in his psychological functioning, communication, animation, personal interest, motivation and insight into his body image. His physical fitness levels also improved and he showed less motor retardation and less body tension.

Phase I clinical and pharmacokinetic study of 3'-deamino-3'-(2-methoxy-4-morpholinyl)doxorubicin (FCE 23762)

Methoxymorpholinyldoxorubicin (FCE 23762) is a novel, highly lipophilic doxorubicin analogue. It possesses potent in vitro and in vivo antitumor activity including efficacy in multidrug-resistant tumor cell lines. It is also metabolically activated in vivo resulting in an 80-fold increase in potency over the parent drug. In this phase I study the drug was administered by i.v. bolus injection at 3-week intervals. Fifty-three patients with refractory solid tumors were treated; 133 courses of FCE 23762 were administered at doses ranging from 30 to 2250 micrograms/m2. The dose limiting toxicity was reversible myelo-suppression (granulocytopenia and thrombocytopenia), demonstrating a delayed nadir and recovery in comparison to doxorubicin. Other toxicities included transient elevation of hepatic transaminases, delayed and prolonged nausea and vomiting, mucositis, anorexia, fatigue, and diarrhea. Heavily pretreated patients demonstrated more myelosuppression than previously untreated patients at 1250 micrograms/m2. No cardiotoxicity was observed. Four objective tumor responses were seen: one complete response in a patient with pelvic recurrence of cervical cancer; one partial response in a patient with cutaneous and lymph gland metastases from head and neck cancer; and two minor responses in patients with liver metastases from colorectal cancer. Plasma concentrations of FCE 23762 and its 13-dihydro metabolite, FCE 26176, were measured in 20 patients at doses > or = 675 micrograms/m2, using HPLC with fluorescence detection. The area under the plasma concentration-time curve ranged from 30 to 80 ng/h/ml; plasma data suggested linear kinetics in the range of tested doses (although there was considerable interpatient variability). The maximum tolerated dose defined in this study using this schedule is 1500 micrograms/m2. A safe phase II dose for previously untreated patients using this schedule is 1250 micrograms/m2; however, this may actually be below the optimal dose for this patient population.

Changes in total pulmonary resistance and PCO2 between wakefulness and sleep in normal human subjects

We investigated the possible role of an increase in total pulmonary resistance in the sleep-related hypoventilation that occurs in healthy subjects. Eight nonsnoring volunteers were studied during quiet wakefulness and stage IV sleep. Airflow was measured via a nasal mask with a low dead space, and breathing pattern, end-tidal PCO2 (PETCO2), and a continuous estimate of total pulmonary resistance were estimated. From wakefulness to sleep, mean inspiratory resistance increased from 5.5 +/- 2.4 (SD) to 8.1 +/- 4.3 cmH2O.l-1.s, PETCO2 increase from 38.7 +/- 3.0 to 40.7 +/- 3.5 Torr, and ventilation decreased from 7.12 +/- 1.15 to 6.47 +/- 1.68 l/min. In five of the eight subjects, low levels of continuous positive airway pressure were applied during stage IV sleep to reverse any increase in resistance. In these subjects, continuous positive airway pressure reduced mean inspiratory resistance from 9.3 +/- 4.3 +/- 3.0 cmH2O.l-1.s but had little effect on mean PETCO2 (from 39.8 +/- 4.0 to 39.6 +/- 4.0 Torr) and mean ventilation (from 6.79 +/- 1.93 to 6.91 +/- 1.80 l/min). These findings suggest that in nonsnoring subjects reductions in alveolar ventilation cannot be accounted for by an increase in airway resistance.

Is voluntary control of breathing impaired in patients with chronic obstructive pulmonary disease?

1. To assess whether voluntary control of breathing is impaired in patients with chronic obstructive pulmonary disease, a group of such patients performed a tracking task, requiring volitional control of respiratory muscles. 2. Eight patients (mean age 60 years; mean ratio of forced expiratory volume in 1 s to forced vital capacity = 31%) took part in the study. Five of the seven patients in whom blood gas measurements were made were mildly hypoxaemic (PaO2 = 53-71 mmHg), and one of these was hypercapnic (PaCO2 = 55 mmHg). Each subject performed a compensatory ventilatory tracking task using a tracking system which comprised a fixed target displayed on a monitor screen and a cursor moving in a line bisecting the target. The position of the cursor was perturbed by a forcing function and patients were required to keep the cursor on the target by breathing in and out of a spirometer. 3. To allow for any non-specific deficiency in motor control, patients performed a similar manual tracking task, using their dominant arm to move a joystick. As a control group, 11 healthy subjects (mean age 58 years; mean ratio of forced expiratory volume in 1 s to forced vital capacity = 77%) underwent an identical experimental protocol. 4. Motor control performances were measured in terms of the error between the target position and the subject's positioning of the cursor. Indices of performance were the root mean square of the error and the averages of the zero errors (i.e. end expiration/arm movement towards the trunk) and the peak errors (i.e. end inspiration/arm movement from the trunk).(ABSTRACT TRUNCATED AT 250 WORDS)

Effect of hyperglycemia duration on rabbit corneal thickness and endothelial ATPase activity

This study compares corneal thickness and corneal endothelial Na,K ATPase activity in normal and age-matched diabetic rabbits with up to 10 weeks of hyperglycemia. Corneal endothelial Na,K ATPase activity in normal rabbits increased between 10 and 20 weeks of age. Corneal thickness increased after 5 weeks of hyperglycemia. Decreased corneal endothelial homogenate Na,K ATPase activity was first seen after 10 weeks of hyperglycemia, though an earlier onset was possible due to sampling restrictions. Corneal endothelial homogenate Mg++ ATPase activity showed a transient increase after 2 to 5 weeks of hyperglycemia. This study shows that hyperglycemia in rabbit is associated with complex dynamic interactions between corneal thickness and corneal endothelial Mg++ ATPase and Na,K ATPase activities.

Somatotopy of human hand somatosensory cortex revealed by dipole source analysis of early somatosensory evoked potentials and 3D-NMR tomography

Somatosensory evoked potentials (SEPs) to median nerve and finger stimulation were analyzed by means of spatio-temporal dipole modelling combined with 3D-NMR tomography in 8 normal subjects. The early SEPs were modelled by 3 equivalent dipoles located in the region of the brain-stem (B) and in the region of the contralateral somatosensory cortex (T and R). Dipole B explained peaks P14 and N18 at the scalp. Dipole T was tangentially oriented and explained the N20-P20, dipole R was radially oriented and modelled the P22. The tangential dipole sources T were located within a distance of 6 mm on the average and all were less than 9 mm from the posterior bank of the central sulcus. In 6 subjects the tangential sources related to finger stimulation arranged along the central sulcus according to the known somatotopy. The radial sources did not show a consistent somatotopic alignment across subjects. We conclude that the combination of dipole source analysis and 3D-NMR tomography is a useful tool for functional localization within the human hand somatosensory cortex.