[Myringoplasties for anterior tympanic perforations: Our surgical technique]. / Myringoplastie pour les perforations tympaniques antérieures: notre technique opératoire.

Anterior tympanic perforations are actually the most difficult to close and a number of different techniques exist. This article represents the author's surgical procedure for type I tympanoplasties (myringoplasties) for this kind of perforation using the tragal cartilage and the perichondrium after preparation (revival, cleaning) of the perforation edge with a laser. This technique does not use a skin incision of external auditory meatus, when this one is large.

[Reconstruction of bone defects in the earcanal with hydroxyapatite]. / Reconstruction des defects osseux du conduit auditif externe par ciment d'hydroxyapatite.

Traditional reconstruction methods of osseous defects within the tympanic frame, most often being the atticotomy, within the framework of chronic otitis media surgery, still do not produce stable or definitive results, usually due to displacement or partial lyse of the transplanted material (cartilage, bone ...). The reconstruction procedure with the aid of hydroxyapatite cement as presented by the authors, allows for a complete, stable and definitive reconstruction.

Frequencies of MICA alleles in patients from southern Brazil with multibacillary and paucibacillary leprosy.

Leprosy is a chronic infectious disease caused by Mycobacterium leprae, which mainly affects the skin and nervous system. The disease has several clinical forms. This study investigated the MICA and HLA-B genes in 223 samples from leprosy patients and 201 samples from healthy individuals matched for age, gender and ethnical background. Of the patients, 153 had multibacillary, 45 paucibacillary and 25 indeterminate leprosy. The aim of this case-control study was to assess whether the MICA alleles influence susceptibility for leprosy or affect the subtype of the disease in a population of southern Brazil. There were significant differences in frequencies of the MICA*027 allele (4.7% vs 1.8%, P-value = 0.01, OR = 0.37; 95% CI = 0.16-0.85) between leprosy patients and controls, and of the MICA*010 (4.5% vs 1.6%, P-value = 0.05, OR = 0.35, 95% CI = 0.13-0.97) and MICA*027 alleles (4.7% vs 1.3%, P-value = 0.01; OR = 0.27; 95% CI = 0.09-0.79) between multibacillary leprosy patients and the control group. There were no significant differences in the frequency of MICA alleles between paucibacillary leprosy patients and controls. Thus, the MICA*027 allele is associated with a protective effect for leprosy per se, while the MICA*010 and MICA*027 alleles are associated with protection against multibacillary leprosy, the most severe clinical subtype.

[Ossiculoplasty with hydroxyapatite bone cement]. / Apport du ciment d'hydroxyapatite en ossiculoplastie.

OBJECTIVE: To analyze the results obtained with hydroxyapatite bone cement (HABC). PATIENTS: A total of 73 ossiculoplasties with HABC were evaluated. Ears were divided into 4 groups: Group 1: Reinforcement of the incudo-stapedial joint with HABC; Group 2: Reconstruction of an incus long process defect with HABC; Group 3: Partial ossicular reconstruction between stapes and malleus handle with HABC; Group 4: Reconstruction of stapes with mobile or fixed footplate with moderate or extensive incus long process erosion using a titanium piston glued to the incus remnant using HABC. RESULTS: The mean follow-up was 21 months. The percentage of postoperative average air-bone gap (ABG) < or = 20 dB for groups 1, 2, 3 and 4 were 100%, 95%, 83% and 91% respectively; for ABG < or = 10 dB: 90%, 71%, 50% and 50%. No complications related to HABC and extrusion occurred. CONCLUSION: Today, the use of HABC seems to help us improve our functional results and also to avoid extrusion. In our experience, ossiculoplastie with HABC seems to provide better and more stable functional results. HABC is safe and easy to use. The use of cement with or without biocompatible ossicular prostheses allows us to repair different types of ossicular defects whilst trying to conserve an anatomical and physiological ossicular chain. Reconstruction of the incus long process or incudo-stapedial joint defect with cement is preferable rather than using partial ossicular reconstruction with HABC.

Regenerative Endodontic Therapy using a New Antibacterial Root Canal Cleanser in necrotic immature permanent teeth: Report of two cases treated in a single appointment.

A case of regenerative endodontics: (a) before treatment; (b) post-treatment Xray; (c) follow-up at 6 months; (d) follow-up at 12 months.

Breast specimen orientation.

Lumpectomy specimens are commonly divided into six sides: superficial, deep, superior, inferior, medial, and lateral. Orienting stitches are placed on the specimen during surgery to allow reorientation by pathology. Despite those efforts, specimen disorientation may occur. The aim of this study was to assess the correlation in orientation between surgeons and pathologists. Lumpectomy specimens were routinely oriented. An additional Prolene suture was randomly placed by the surgeon on one side to be localized by pathology. The results were recorded and the disorientation rate calculated. Specimen size and presence of skin and/or muscle were also recorded. There were 122 lumpectomy specimens prospectively entered. Average specimen volume was 95.5 cm(3). Twenty-four specimens had segments of skin or muscle. The additional sutures were evenly divided between the six sides. The overall disorientation rate was 31.1% (95% confidence interval, 23.1-40.2).The side-specific disorientation rates were 43%, 40%, 35%, 29%, 28%, and 14% for the deep, superficial, lateral, medial, superior, and inferior surfaces, respectively (no statistical difference). Presence of skin or muscle on the specimen did not contribute to better orientation. Specimen volumes, however, were highly associated with orientation. Specimens of <20 cm(3) had a disorientation rate of 78%, while larger specimen had a disorientation rate of 20% (p < .001). Specimen orientation with stitches placed on two surfaces is associated with a high disorientation rate. Better orientation techniques are necessary to minimize the specimen disorientation.

Periodontal conditions of sites treated with gingival-augmentation surgery compared to untreated contralateral homologous sites: a 10- to 27-year long-term study.

BACKGROUND: The aim of this retrospective long-term split-mouth study was to compare the periodontal conditions of sites treated with gingival-augmentation procedures to untreated homologous contralateral sites over a long period of time (10 to 27 years). METHODS: Fifty-five subjects with 73 sites (test group) lacking attached gingiva associated with recessions were treated by means of submarginal free gingival grafts (SMFGGs) and marginal free gingival grafts (MFGGs). The 73 contralateral homologous sites (control group), with or without recession and with or without attached gingiva, were not treated. Patients were recalled every 4 months during the follow-up period (10 to 27 years). Clinical variables, including recession depth, amount of keratinized tissue (KT), and probing depth (PD), were measured in treated and untreated sites at baseline, at 1 year, and at the end of the follow-up period. RESULTS: At the end of the follow-up period, recession was reduced in all treated sites (1.5 +/- 1.0 mm for SMFGG and 1.3 +/- 0.9 mm for MFGG), whereas it was increased in the untreated sites (-0.7 +/- 0.7 mm for SMFGG and -1.0 +/- 0.5 mm for MFGG). In the treated sites, the increased KT remained quite stable during the follow-up period. PD remained stable (1 mm) in the treated and untreated sites. CONCLUSIONS: The sites treated with gingival-augmentation surgery showed a tendency for coronal displacement of the gingival margin with a reduction in recession. The contralateral untreated sites showed a tendency for apical displacement of the gingival margin with an increase in the existing recessions.

Association between killer-cell immunoglobulin-like receptor genotypes and leprosy in Brazil.

The aim of this study was to investigate the role of killer cell immunoglobulin-like receptor (KIR) genes in leprosy immunopathogenesis. Genotyping of KIR and human leukocyte antigen (HLA) genes was performed by polymerase chain reaction with sequence-specific oligonucleotide probes in 165 leprosy patients. Both activating KIR2DS2 and KIR2DS3 frequencies were higher in tuberculoid leprosy (TT) patients than in lepromatous leprosy (LL) patients, and the inhibitory KIR with its ligand, KIR2DL1-C2/C2, was elevated in TT patients in comparison to all other leprosy subgroups and controls. However, a negative association between KIR2DL3-C1 and KIR2DL3-C1/C1 and the TT group was identified. Borderline patients exhibited a higher frequency of KIR3DL2-A3/11 than the controls and LL patients, and a lower frequency of KIR2DL1-C2 than the controls and TT subgroup. Some KIR-HLA genotypes could be associated to the development of clinical forms of leprosy and should be investigated further.

Two-stage revision after total knee arthroplasty.

BACKGROUND AND AIM OF THE WORK: Periprosthetic knee infection is a complication associated with prosthetic failure; incidence change from 0,4-2% of primary total knee replacement and 5,6% in revisions; incidence is increasing over the years. Two-stage revision is the technique used in chronic infection. Aim of the work is to check success rate in our data. Methods. We analyzed retrospectively data of patients who undergone two stage revision surgery between 01/01/2010 to 31/12/2015. We made a clinical and radiological control after 1, 3, 6, 12, 24 months and we evaluate the outcome in December 2016. Results. Between 2010 and 2015 we treated 45 patients with two-stage revision. Mean follow-up was 3,4 years. Success rate is 89,9%. We had failure in 5 patients: everyone had knee surgery before first knee arthroplasty and Charlson Comorbidity Score was greater then 4 in 4 cases. Conclusions. Two stage revision can be considered a successful treatment in chronic periprosthetic knee infection. It has an optimal success rate, but it has some disadvantages as joint stiffness and pain in the interval between stages. This is a technique with two major surgery procedure with associated morbidity, discomfort, cost and prolonged stay in hospital.

Radioimmunoscintigraphy of colorectal carcinoma using technetium-99m-labeled, totally human monoclonal antibody 88BV59H21-2.

Radioimmunoscintigraphy (RIS) using human monoclonal antibodies offers the important clinical advantage of repeated imaging over murine monoclonal antibodies by eliminating the cross-species antibody response. This article reports a Phase I-II clinical trial with Tc-99m-labeled, totally human monoclonal antibody 88BV59H21-2 in patients with colorectal carcinoma. The study population consisted of 34 patients with colorectal cancer (20 men and 14 women; age range, 44-81 years). Patients were administered 5-10 mg antibody labeled with 21-41 mCi Tc-99m by the i.v. route and imaged at 3-10 and 16-24 h after infusion using planar and single-photon emission computed tomographic (CT) techniques. Pathological confirmation was obtained in 25 patients who underwent surgery. Human antihuman antibody (HAHA) titers were checked prior to and 1 and 3 months after the infusion. RIS with Tc-99m-labeled 88BV59H21-2 revealed a better detection rate in the abdomen-pelvis region compared with axial CT. The combined use of both modalities increased the sensitivity in both the liver and abdomen-pelvis regions. Ten patients developed mild adverse reactions (chills and fever). No HAHA response was detected in this series. Tc-99m-labeled human monoclonal antibody 88BV59H21-2 RIS shows promise as a useful diagnostic modality in patients with colorectal cancer. RIS alone or in combination with CT is more sensitive than CT in detecting tumor within the abdomen and pelvis. Repeated RIS studies may be possible, due to the lack of a HAHA response.

Therapeutic doses of oral methylphenidate significantly increase extracellular dopamine in the human brain.

Methylphenidate (Ritalin) is the most commonly prescribed psychoactive drug in children for the treatment of attention deficit hyperactivity disorder (ADHD), yet the mechanisms responsible for its therapeutic effects are poorly understood. Whereas methylphenidate blocks the dopamine transporter (main mechanism for removal of extracellular dopamine), it is unclear whether at doses used therapeutically it significantly changes extracellular dopamine (DA) concentration. Here we used positron emission tomography and [(11)C]raclopride (D2 receptor radioligand that competes with endogenous DA for binding to the receptor) to evaluate whether oral methylphenidate changes extracellular DA in the human brain in 11 healthy controls. We showed that oral methylphenidate (average dose 0.8 +/- 0.11 mg/kg) significantly increased extracellular DA in brain, as evidenced by a significant reduction in B(max)/K(d) (measure of D2 receptor availability) in striatum (20 +/- 12%; p < 0.0005). These results provide direct evidence that oral methylphenidate at doses within the therapeutic range significantly increases extracellular DA in human brain. This result coupled with recent findings of increased dopamine transporters in ADHD patients (which is expected to result in reductions in extracellular DA) provides a mechanistic framework for the therapeutic efficacy of methylphenidate. The increase in DA caused by the blockade of dopamine transporters by methylphenidate predominantly reflects an amplification of spontaneously released DA, which in turn is responsive to environmental stimulation. Because DA decreases background firing rates and increases signal-to-noise in target neurons, we postulate that the amplification of weak DA signals in subjects with ADHD by methylphenidate would enhance task-specific signaling, improving attention and decreasing distractibility. Alternatively methylphenidate-induced increases in DA, a neurotransmitter involved with motivation and reward, could enhance the salience of the task facilitating the "interest that it elicits" and thus improving performance.

Loss of dopamine transporters in methamphetamine abusers recovers with protracted abstinence.

Methamphetamine is a popular drug of abuse that is neurotoxic to dopamine (DA) terminals when administered to laboratory animals. Studies in methamphetamine abusers have also documented significant loss of DA transporters (used as markers of the DA terminal) that are associated with slower motor function and decreased memory. The extent to which the loss of DA transporters predisposes methamphetamine abusers to neurodegenerative disorders such as Parkinsonism is unclear and may depend in part on the degree of recovery. Here we assessed the effects of protracted abstinence on the loss of DA transporters in striatum, in methamphetamine abusers using positron emission tomography and [(11)C]d-threo-methylphenidate (DA transporter radioligand). Brain DA transporters in five methamphetamine abusers evaluated during short abstinence (<6 months) and then retested during protracted abstinence (12-17 months) showed significant increases with protracted abstinence (caudate, +19%; putamen, +16%). Although performance in some of the tests for which we observed an association with DA transporters showed some improvement, this effect was not significant. The DA transporter increases with abstinence could indicate that methamphetamine-induced DA transporter loss reflects temporary adaptive changes (i.e., downregulation), that the loss reflects DA terminal damage but that terminals can recover, or that remaining viable terminals increase synaptic arborization. Because neuropsychological tests did not improve to the same extent, this suggests that the increase of the DA transporters was not sufficient for complete function recovery. These findings have treatment implications because they suggest that protracted abstinence may reverse some of methamphetamine-induced alterations in brain DA terminals.

Gastric carcinoids: a temporal increase with proton pump introduction.

BACKGROUND: Recent reports have indicated a rising incidence of gastric carcinoids. This study aimed to evaluate the incidence pattern of gastric carcinoids in two large population-based cancer registries. METHODS: The Florida Cancer Data System (FCDS), Florida's statewide cancer registry, and the Surveillance, Epidemiology, and End Results (SEER) program were used. The study population was defined as all cases of gastric carcinoid identified in either database from January 1981 to December 2000. Descriptive statistics and age-adjusted incidence rates were calculated. RESULTS: There were 326 (FCDS) and 594 (SEER) cases of invasive gastric carcinoid during the 20-year study period. The mean age of the patients was 65 years (range, 21-96 years), and the male:female ratio was 1:1. The age-adjusted incidence rate in FCDS increased from 0.04 (per 100,000 age-adjusted to the 2000 U.S. standard population) to 0.18 in the year 2000. The estimated annual percentage change in incidence was 8.17 in FCDS and 9.17 in SEER (p < 0.05). A decrease in gastric cancer was noted during this same period (from 8.64 to 11.14 cases per 100,000 in FCDS and from 11.14 to 8.06 cases per 100,000 in SEER). CONCLUSIONS: This study documented a statistically significant eight- or ninefold increase in the incidence of gastric carcinoids in two large databases. The temporal increase in incidence correlates with the introduction and widespread use of proton pump inhibitors since the late 1980s. Other explanations include improved detection with wider application of upper endoscopy. Further epidemiologic studies are warranted.

Maintenance of brain monoamine oxidase B inhibition in smokers after overnight cigarette abstinence.

OBJECTIVE: The authors' goal was to replicate a previous finding that smokers have lower brain monoamine oxidase B (MAO-B) levels than comparison nonsmoking subjects and to determine if levels recover after overnight cigarette abstinence. METHOD: Brain MAO-B levels were measured by means of positron emission tomography in six smokers who were scanned twice: 11.3 hours (baseline) and 10 minutes after smoking one cigarette. RESULTS: Average MAO-B levels in smokers in the present study were similar to those found in the previous study and averaged 39% (SD=17) lower than those found in a comparison group of nonsmokers. Brain MAO-B levels did not differ between baseline levels and 10 minutes after smoking. CONCLUSIONS: This study reinforces the need to investigate whether MAO-B inhibition may account for some of the behavioral and epidemiological features of smoking.

Higher cortical and lower subcortical metabolism in detoxified methamphetamine abusers.

OBJECTIVE: Methamphetamine has raised concerns because it may be neurotoxic to the human brain. Although prior work has focused primarily on the effects of methamphetamine on dopamine cells, there is evidence that other neuronal types are affected. The authors measured regional brain glucose metabolism, which serves as a marker of brain function, to assess if there is evidence of functional changes in methamphetamine abusers in regions other than those innervated by dopamine cells. METHOD: Fifteen detoxified methamphetamine abusers and 21 comparison subjects underwent positron emission tomography following administration of [(18)F]fluorodeoxyglucose. RESULTS: Whole brain metabolism in the methamphetamine abusers was 14% higher than that of comparison subjects; the differences were most accentuated in the parietal cortex (20%). After normalization for whole brain metabolism, methamphetamine abusers exhibited significantly lower metabolism in the thalamus (17% difference) and striatum (where the differences were larger for the caudate [12%] than for the putamen [6%]). Statistical parametric mapping analyses corroborated these findings, revealing higher metabolism in the parietal cortex and lower metabolism in the thalamus and striatum of methamphetamine abusers. CONCLUSIONS: The fact that the parietal cortex is a region devoid of any significant dopaminergic innervation suggests that the higher metabolism seen in this region in the methamphetamine abusers is the result of methamphetamine effects in circuits other than those modulated by dopamine. In addition, the lower metabolism in the striatum and thalamus (major outputs of dopamine signals into the cortex) is likely to reflect the functional consequence of methamphetamine in dopaminergic circuits. These results provide evidence that, in humans, methamphetamine abuse results in changes in function of dopamine- and nondopamine-innervated brain regions.

Low level of brain dopamine D2 receptors in methamphetamine abusers: association with metabolism in the orbitofrontal cortex.

OBJECTIVE: The role of dopamine in the addictive process (loss of control and compulsive drug intake) is poorly understood. A consistent finding in drug-addicted subjects is a lower level of dopamine D2 receptors. In cocaine abusers, low levels of D2 receptors are associated with a lower level of metabolism in the orbitofrontal cortex. Because the orbitofrontal cortex is associated with compulsive behaviors, its disruption may contribute to compulsive drug intake in addicted subjects. This study explored whether a similar association occurs in methamphetamine abusers. METHOD: Fifteen methamphetamine abusers and 20 non-drug-abusing comparison subjects were studied with positron emission tomography (PET) and [11C]raclopride to assess the availability of dopamine D2 receptors and with [18F]fluorodeoxyglucose to assess regional brain glucose metabolism, a marker of brain function. RESULTS: Methamphetamine abusers had a significantly lower level of D2 receptor availability than comparison subjects (a difference of 16% in the caudate and 10% in the putamen). D2 receptor availability was associated with metabolic rate in the orbitofrontal cortex in abusers and in comparison subjects. CONCLUSIONS: Lower levels of dopamine D2 receptor availability have been previously reported in cocaine abusers, alcoholics, and heroine abusers. This study extends this finding to methamphetamine abusers. The association between level of dopamine D2 receptors and metabolism in the orbitofrontal cortex in methamphetamine abusers, which replicates previous findings in cocaine abusers, suggests that D2 receptor-mediated dysregulation of the orbitofrontal cortex could underlie a common mechanism for loss of control and compulsive drug intake in drug-addicted subjects.

Association of dopamine transporter reduction with psychomotor impairment in methamphetamine abusers.

OBJECTIVE: Methamphetamine is a popular and highly addictive drug of abuse that has raised concerns because it has been shown in laboratory animals to be neurotoxic to dopamine terminals. The authors evaluated if similar changes occur in humans and assessed if they were functionally significant. METHOD: Positron emission tomography scans following administration of [(11)C]d-threo-methylphenidate (a dopamine transporter ligand) measured dopamine transporter levels (a marker of dopamine cell terminals) in the brains of 15 detoxified methamphetamine abusers and 18 comparison subjects. Neuropsychological tests were also performed to assess motor and cognitive function. RESULTS: Methamphetamine abusers showed significant dopamine transporter reduction in the striatum (mean differences of 27.8% in the caudate and 21.1% in the putamen) relative to the comparison subjects; this reduction was evident even in abusers who had been detoxified for at least 11 months. Dopamine transporter reduction was associated with motor slowing and memory impairment. CONCLUSIONS: These results provide evidence that methamphetamine at dose levels taken by human abusers of the drug leads to dopamine transporter reduction that is associated with motor and cognitive impairment. These results emphasize the urgency of alerting clinicians and the public of the long-term changes that methamphetamine can induce in the human brain.

Thyroglobulin determination, neck ultrasonography and iodine-131 whole-body scintigraphy in differentiated thyroid carcinoma.

UNLABELLED: The long-term prognosis of patients with differentiated thyroid carcinoma depends on the early diagnosis and treatment of metastases and local recurrences. We evaluated serum thyroglobulin measurements, neck ultrasonography with ultrasound-guided biopsy and 131I whole-body scintigraphy in the follow-up of 359 patients after surgical thyroidectomy and radioiodine ablation of the thyroid remnant. METHODS: Serum thyroglobulin levels were determined and considered abnormal when the values were > 5 ng/ml. Ultrasonography over the entire neck region and fine-needle aspiration biopsy of the mass or enlarged lymph nodes were carried out using 5- and 7.5-MHz transducers and 23-gauge needles. Whole-body scintigraphy was performed after administration of 185 MBq (5 mCi)131I. RESULTS: Increased levels of thyroglobulin (ranging from 12 to > 600 ng/ml) were measured in 40 of 55 (73%) patients with metastases or local recurrences. Ultrasonography revealed occult neck masses that were not detected by other methods. Neck ultrasonography and ultrasound-guided biopsy were positive for malignancy in 23 patients. Thyroglobulin levels were undetectable in 12 (52%) of these patients and 131I whole-body scintigraphy was negative in 19 (83%) of them. CONCLUSION: The combined use of three diagnostic modalities (measurement of serum thyroglobulin, neck ultrasonography with ultrasound-guided biopsy for detecting recurrences of carcinoma in the neck region and 131I whole-body scintigraphy) appears to give the best results in the follows-up patients with differentiated thyroid carcinoma.

Technetium-99m methoxyisobutyl isonitrile (RP30) for quantification of myocardial ischemia and reperfusion in dogs.

This study was done to determine whether [99mTc]methoxyisobutyl isonitrile (RP30), a nonredistributing myocardial perfusion agent, could be used to quantify regional myocardial blood flow distribution during ischemia and reperfusion, employing sequential injections of tracer, tomographic imaging, and appropriate image subtraction. Dogs underwent transient (6 min) coronary artery occlusion, followed by two paired injections of RP30 and radioactive microspheres combined with tomographic imaging, the first during coronary occlusion and the second after 60 min of reperfusion. To obtain a true image representative of reperfusion, the first set of images was corrected for 99mTc decay and subtracted from the second. During occlusion, tissue microsphere content and scintigraphic RP30 activity in the center of the ischemic region (both expressed as a fraction of the nonischemic region) were closely correlated, although RP30 consistently exceeded microsphere content (0.43 +/- 0.03 vs. 0.24 +/- 0.04, p less than 0.01). Direct tissue counting of RP30 confirmed its relative excess in ischemic myocardium. Reperfusion was successful in 7/8 dogs, with an increase in RP30 activity to 0.98 +/- 0.04 compared to 0.89 +/- 0.03 for microspheres (p = N.S.). In one dog with microsphere-documented persistent ischemia, the RP30 defect was still present after reflow. Our results indicate that because of the lack of myocardial clearance and redistribution, repeat injections of RP30 can be used to quantify serial changes in regional myocardial blood flow.

PET studies of the effects of aerobic exercise on human striatal dopamine release.

UNLABELLED: In vivo microdialysis studies have shown that exercise increases the concentration of dopamine (DA) in the striatum of the rat brain. It has also been shown that PET with [11C]raclopride can be used to assess changes in brain DA induced by drugs and by performance tasks such as playing a video game. The purpose of this study was to evaluate the effects of exercise (treadmill running) on striatal DA release in the human brain. METHODS: Twelve healthy volunteers (5 women, 7 men; mean age, 32 +/- 5 y; age range, 25-40 y) with a history of regular exercise received 2 PET scans with [11C]raclopride on 2 separate days, 1 at baseline and 1 at 5-10 min after running on a treadmill for 30 min. The speed and inclination of the treadmill were increased gradually to reach a maximal speed of 9.7 km/h (6 mph) and a maximal inclination of 10degrees. Data were acquired on a Siemens HR+ scanner in 3-dimensional mode for 60 min. Heart rates and electrocardiograms were monitored. DA D2 receptor availability was measured using the ratio of the distribution volume in the putamen to that in the cerebellum, which is a function of the number of available binding sites/dissociation constant. RESULTS: The subjects ran at an average speed of 8.7 +/- 0.5 km/h (5.4 +/- 0.3 mph) and at an inclination of 3.3degrees +/- 2degrees. The maximum effort of running was maintained for 10-15 min. The heart rates of the subjects were increased by 143% +/- 47%. DA D2 receptor availability in the putamen after treadmill running (4.22 +/- 0.34) was no different from that of baseline (4.17 +/- 0.29; P < 0.6). CONCLUSION: No significant changes in synaptic DA concentration were detected, although the subjects exercised vigorously for 30 min.