Superantigen-induced stromelysin production from rheumatoid synovial cells

Positron emission topographic studies on local cerebral glucose metabolism in Parkinson's disease (PD) including our own data were reviewed. In our 18F-FDG PET studies, local or global metabolic change was not found in 9 patients with non-demented PD, with respect to 5 normal controls. Moreover, there was not an apparent difference between severe PD group (Hoehn-Yahr III-IV) and mild PD group (Hoehn-Yahr I-II). In other PD patients with dementia or autonomic failure, parietal dominant hypometabolism was found likely to those of Alzheimer disease, but lenticular nucleus was well preserved. Furthermore 18F-FDG PET findings of atypical parkinsonian syndromes, such as SND and PSP were reviewed. They showed relative hypometabolism in the basal ganglia in PET images. PET study with FDG provides a clue to differential diagnosis of parkinsonian patients.     

The metabolic anatomy of Tourette's syndrome

The functional brain networks underlying the clinical manifestations of Gilles de la Tourette's syndrome (TS) are currently unknown. To identify these networks, we studied TS patients and normal subjects with 18F-fluorodeoxyglucose (FDG) and PET employing a statistical model of regional metabolic covariation. We studied 10 TS patients (mean age, 41.5 +/- 12.7 years) who were either drug naive or medication free for at least 2 years. Ten normal volunteers (mean age, 42.5 +/- 11.5) served as controls. We used quantitative FDG/PET to calculate global, regional, and normalized rates of glucose metabolism (GMR, rCMRGlc, and rCMRGlc/GMR) in all subjects. The Scaled Subprofile Model (SSM) was used to identify specific patterns of regional metabolic covariation associated with TS. We found that global and regional metabolic rates were normal in TS. SSM analysis identified two TS-related brain networks. One pattern (15.8% variance accounted for, VAF) was characterized by covariate bilateral metabolic increases in lateral premotor and supplementary motor association cortices and in the midbrain. Individual patient expression of this pattern (subject score) was abnormally increased in the TS group (p < 0.01). A second pattern (10.5% VAF) was characterized by covariate decreases in caudate and thalamic metabolism associated with smaller reductions in lentiform and hippocampal metabolic activity. Subject scores for this pattern correlated with Tourette Syndrome Global Scale (TSGS) global ratings (r = 0.85, p < 0.005). We conclude that the metabolic landscape of TS is characterized by a nonspecific pattern of increased motor cortical activity identified in other hyperkinetic disorders. TS is also associated with a specific brain network characterized by a reduction in the activity of limbic basal ganglia-thalamocortical projection systems.     

A randomized controlled trial of filgrastim as an adjunct to antibiotics for treatment of hospitalized patients with community-acquired pneumonia. CAP Study Group

OBJECTIVE: The aims of the study were to follow prospectively the intrasubject progression of idiopathic PD in a cohort of patients using levodopa kinetic-dynamic modeling and to assess the relation between the rate of progression of the disease and patients' different clinical characteristics. METHODS: Thirty-four patients (Hoehn and Yahr stages 1 to 3) enrolled in the longitudinal follow-up. Each patient was examined at 1-year intervals over a median 4 years by a standardized oral levodopa test. The primary measure outcome was the computed half-life of levodopa in the "effect compartment" (t1/2eq), a proposed indicator of nigrostriatal dopaminergic functionality and integrity. RESULTS: Values of levodopa t1/2eq correlated negatively with severity of symptoms (r = -0.652, p < 0.0001) and decreased over the years together with a worsening of patients' clinical stage (p < 0.001). The rate of reduction in drug t1/2eq was more rapid in patients at the earlier stages of the disease compared with the more advanced ones, falling from a median annual reduction of 37 minutes in patients at initial Hoehn and Yahr stage 1 to 6.5 minutes in stage 3 patients (p < 0.001). Patients without tremor at onset, otherwise comparable to patients with tremor for baseline values of levodopa t1/2eq, disease severity, duration, and daily dose of levodopa, tended to show a higher rate of reduction in levodopa t1/2eq than patients with tremor. Overall, patients' annual reduction in levodopa t1/2eq over baseline values averaged 17+/-9%. CONCLUSIONS: These results are in keeping with PET findings on the objective assessment of idiopathic parkinsonism evolution, and they support the suggestion that levodopa pharmacodynamic modeling may offer a practical clinical tool to assess indirectly the functional integrity of the nigrostriatal dopaminergic system over time in parkinsonian patients.     

The solution structure of the human retinoic acid receptor-beta DNA-binding domain

Parkinsonism is a feature not only of Parkinson's disease but also of many other diseases affecting basal ganglia function. Functional imaging (PET and SPECT) can demonstrate the various resting patterns of disruption of regional cerebral blood flow, metabolism, and neuropharmacology associated with different parkinsonian disorders. 18F-dopa PET also has the potential to detect subclinical dysfunction of dopaminergic terminals in at-risk subjects. Finally, functional imaging can help us understand the nature of the networks involved in performing different motor tasks, and can reveal how these networks malfunction in the presence of bradykinesia or parkinsonian tremor.     

FDG uptake, GLUT-1 glucose transporter and cellularity in human pancreatic tumors

We previously reported that grading of GLUT-1 glucose transporter expression was related closely to FDG accumulation in FDG PET in human cancers. But in this strong GLUT-1 expression group, there was an enormous range of standardized uptake values (SUVs) within them. METHODS: To evaluate other factors determining the FDG PET uptake, FDG PET was performed in 36 preoperative patients (mean age 62.0 yr) suspected of having pancreatic tumors, including 33 malignant and 3 benign neoplastic tumors. FDG uptake at 50 min after injection of 185 MBq 18F-FDG with > 5 hr fasting condition was semiquantitatively analyzed as SUVs. The GLUT-1 expression was studied by immunohistochemistry of paraffin sections from these tumors after the operation using the antiGLUT-1 antibody. The number of tumor cells within a 5- x 5-mm square was counted manually using x200 magnification photographs and was graded immunohistochemically as strong, weak or negative. RESULTS: In all 36 cases there were 3 cases of GLUT-1 negative, 8 of GLUT-1 weak positive and 25 of GLUT-1 strong positive. In all cases, the total number of tumor cells had no significant value for SUVs. Among 33 GLUT-1 positive cases, the number of GLUT-1 positive tumor cells correlated significantly with SUVs (p < 0.01). Only in 25 strong grade cases, the number of GLUT-1 strong positive tumor cells had a more significant value for SUVs (p < 0.005). Computational multivariate analysis using multiple regression for SUVs was performed evaluating the five variables as follows: tumor size, GLUT-1 immunohistochemical grading, number of total tumor cells, number of total GLUT-1 positive tumor cells and number of GLUT-1 strong positive cells. This analysis revealed that only the variable, the number of GLUT-1 strong positive cells, had a significant regression coefficient for SUVs (standard regression coefficient = 0.855, p < 0.0001). CONCLUSION: These data indicate that GLUT-1 expression plays an essential role in higher FDG accumulation in pancreatic tumor FDG PET, and the cellularity has a significant influence on SUVs only in the condition of GLUT-1 strong positive expression.     

Preoperative evaluation of 54 gliomas by PET with fluorine-18-fluorodeoxyglucose and/or carbon-11-methionine

This study evaluates the usefulness of PET for the preoperative evaluation of brain gliomas and methods of quantification of PET results. METHODS: Fifty-four patients with brain gliomas were studied by PET with 18F-fluorodeoxyglucose (FDG) (n = 45) and/or 11C-methionine (MET) (n = 41) before any treatment. Results of visual analysis, calculation of glucose consumption and five tumor-to-normal brain ratios for both tracers were correlated with two histologic grading systems and with follow-up. RESULTS: Visual analysis (for FDG) and tumor-to-mean cortical uptake (T/MCU) ratio proved to be the best tools for the evaluation of PET results. Methionine was proven to be better than FDG at delineating low-grade gliomas. Tumor-to-mean cortical uptake ratios for FDG and MET were clearly correlated (r = 0.78), leading to the equation T/MCU(FDG) = 0.4 x T/MCU(MET). We showed a good correlation between FDG PET and histologic grading. MET uptake could not differentiate between low-grade and anaplastic astrocytomas but was significantly increased in glioblastomas. Low-grade oligodendrogliomas exhibited high uptake of FDG and MET, probably depending more on oligodendroglial cellular differentiation than on proliferative potential. Uptake was decreased in anaplastic oligodendrogliomas, probably due to dedifferentiation. Care must be taken with peculiar histologic subgroups, i.e., juvenile pilocytic astrocytomas and oligodendrogliomas, because of a discrepancy between high PET metabolism and low proliferative potential (good prognosis). Both tracers proved useful for the prediction of survival prognosis. Methionine proved slightly superior to FDG for predicting the histologic grade and prognosis of gliomas, despite the impossibility of differentiation between Grades II and III astrocytomas with MET. This superiority of MET could be explained by patient sampling (low number of Grade III gliomas submitted to examination with both tracers). The combination of both tracers improved the overall results compared to each tracer alone. CONCLUSION: Both tracers are useful for the prediction of the histologic grade and prognosis. The apparent superiority of MET over FDG could be due to the small number of Grade III gliomas studied with both tracers.     

Clinical positron emission tomography for brain tumors: comparison of fludeoxyglucose F 18 and L-methyl-11C-methionine

PURPOSE: To evaluate the differences between fludeoxyglucose F 18 (FDG) and L-methyl-11C-methionine (11C-methionine) as tracers for positron emission tomography (PET) in the evaluation of brain tumors. METHODS: We analyzed 10 patients with histologically verified cerebral glioma or meningioma and 1 patient with a neuroradiologic diagnosis of low-grade glioma by using FDG, 11C-methionine, and PET. We qualitatively and quantitatively evaluated the extent and degree of accumulation of FDG and 11C-methionine in the tumor tissue. RESULTS: Although PET with FDG depicted malignant tumors as a hot spot in all cases, it was not able to delineate the extent of the tumor. Conversely, PET with 11C-methionine outlined the tumors as areas of increased accumulation of 11C-methionine, regardless of the degree of malignancy. CONCLUSION: PET with FDG and with 11C-methionine can play complementary roles in the evaluation of brain tumors.     

Fluorine-18-fluorodeoxyglucose and carbon-11-methionine evaluation of lymphadenopathy in sarcoidosis

Uptake of 18F-fluorodeoxyglucose (FDG) and 11C-methionine (Met) in mediastinum and hilar lymph nodes was studied using PET in 31 patients with sarcoidosis. The aim of our study was to examine whether these different tracers play a differential role in clinical assessment of pulmonary involvement. METHODS: Fluorine-18-fluorodeoxyglucose and 11C-Met PET were administered on different days. The differential absorption ratio of these tracers was calculated for the region of interest with the highest level of activity. Clinical reassessment of sarcoidosis was made at least 1 yr after the first PET examination. In seven patients whose lymph nodes still remained visible by other imagings at the time of reevaluation, the same PET study was performed again. RESULTS: Both FDG and Met were accumulated in the lymph nodes in all but one patient. The FDG and Met uptake ratios in all patients were not correlated, but they could be divided into the FDG-dominant group (FDG/Met uptake ratio > or = 2) and the Met-dominant group (FDG/Met uptake ratio < 2). Within each group, the FDG and Met uptake values were correlated. The rate of improvement assessed by clinical status and chest radiographs was considerably higher in the FDG- (78%) than in the Met-dominant group (33%). In the seven patients of the repeated PET examination, their FDG/Met uptake ratios were generally unchanged after 1 yr. CONCLUSION: The results suggest that the FDG/Met uptake ratio using PET may reflect the differential granulomatous status in sarcoidosis and be a useful tool for pretreatment evaluation.     

Clozapine in Parkinson's disease tremor. Effects of acute and chronic administration

The effects of the acute administration of clozapine on parkinsonian mixed tremor (i.e., resting and postural tremors) were evaluated to establish clozapine's predictive value for long-term response and to determine if there is a difference in the pharmacologic responses of the two tremors. We also investigated the correlation between reduction of tremor and induction of sedation after acute and chronic administration of clozapine. Clozapine (12.5 mg) or placebo were administered po in a double-blind manner to 17 PD patients with mixed L-dopa-resistant tremors. Two patients did not reach 50% improvement and were considered nonresponders. The remaining 15 patients reported moderate to marked reduction of tremor. Responsive patients in the acute test moved on to a long-term, open clozapine add-on study receiving an average daily dose +/- SD of 45 +/- 9.6 mg for a period of 15.5 +/- 8.3 months. A significant reduction of both resting (p < 0.05) and postural (p < 0.05) tremors was observed under clozapine from the first week of treatment through the entire period of the study. There was no statistically significantly difference between the degree of improvement for resting and postural tremors after either single or chronic clozapine administration. Sedation was the only side effect reported after clozapine; however, the time courses of sedation and tremor reduction did not coincide in the acute or in the chronic experimental paradigm, where it decreased considerably in a few weeks in all patients. During long-term clozapine treatment, neither systemic side effects nor worsening of motor disability scores were noted. Thus we wish to propose an acute test or a therapeutic attempt, or both, with clozapine before defining a case of mixed parkinsonian tremor as resistant tremor and therefore resorting to a neurosurgical approach.     

Anorectal manometry in the assessment of anorectal function in Parkinson's disease: a comparison with chronic idiopathic constipation

We investigated the role of anorectal manometry in evaluating constipation and anorectal function in 15 patients with Parkinson's disease (PD) and compared results with those of 9 patients with idiopathic constipation (IC) and 8 control (C) subjects. Anal sphincter pressures on voluntary squeeze were lower in the PD patients. Sustained squeeze pressures (mm Hg C versus IC versus PD: 46.8 +/- 5.2 versus 31.2 +/- 3.6 versus 26.6 +/- 3.9; p < 0.05 PD versus C), squeeze duration (seconds: 53.6 +/- 2.5 versus 48.5 +/- 4.1 versus 33.6 +/- 9; p < 0.05 PD versus C) and squeeze index (area under the squeeze curve: 44.0 +/- 2.9 versus 34.5 +/- 3.3 versus 21.4 +/- 2.9; p < 0.001 PD versus C) were significantly lower in the PD group in comparison to the control group. In contrast, none of the parameters of anorectal manometry differed between controls and patients with idiopathic constipation. Some Parkinson's disease patients demonstrated an abnormal, hypercontractile response on testing of the rectoanal inhibitory reflex. Anal sphincter length, basal sphincter pressures, maximal squeeze pressures, extent of relaxation on rectoanal inhibitory reflex and threshold volume for rectal sensation were similar in the three groups. We conclude that an impaired squeeze response is a specific feature of anorectal function in Parkinson's disease. This may indicate direct involvement of the pelvic floor musculature by the parkinsonian disease process.     

Diagnosis of pancreatic carcinoma: role of FDG PET

OBJECTIVE: The purpose of this study was to investigate the role of positron emission tomography (PET) with 18F-fluorodeoxyglucose (FDG) in differentiating benign from malignant disease in patients with possible pancreatic malignancy. SUBJECTS AND METHODS: All patients with a possible diagnosis of pancreatic carcinoma based on CT or ERCP findings were eligible for inclusion in this prospective study. PET imaging of the abdomen was performed in 37 patients and was interpreted as positive if FDG activity in the pancreas exceeded background activity and as negative if activity was less than or equal to background activity. Semiquantitative analysis was performed by calculating a standardized uptake ratio. Studies were reviewed independently by two radiologists, and results were correlated with biopsy results and with CT and ERCP findings. Sensitivity and specificity of FDG PET for revealing pancreatic malignancy was determined. RESULTS: FDG activity in the pancreas was increased in 24 patients, and adenocarcinoma was diagnosed in 22 of these patients (92%). Two patients (8%) with increased activity had benign disease, including one patient with chronic pancreatitis who showed no evidence of tumor at laparotomy and one patient with a mucinous cystic tumor who showed no malignant features at laparotomy. FDG uptake was low or normal in 13 patients, 10 of whom (77%) had benign disease. FDG uptake was also low in three patients with adenocarcinoma, whose tumor size ranged from 2 to 4 cm in diameter. The mean standardized uptake ratio value for malignant disease was 5.1 (range, 1.0-10.1) and for benign disease was 1.9 (range, 0.0-5.8) (p < .001). The sensitivity of FDG PET for revealing malignant disease in the pancreas was 88% and the specificity was 83%. CONCLUSION: FDG PET is a sensitive and specific noninvasive technique for the diagnosis of pancreatic malignancy.     

Surgical interventions in the treatment of Parkinson's disease (PD) and essential tremor (ET): medial pallidotomy in PD and chronic deep brain stimulation (DBS) in PD and ET

Surgical treatments for PD and ET are promising. Medial Pallidotomy, the surgical lesioning of the pallidum, often improves symptoms of long-standing PD. We enrolled twenty-seven late stage PD patients for unilateral medial pallidotomy who were then assessed by the Core Assessment Program for Intracranial Transplantation (CAPIT) protocol. One year after surgery persistent improvement was seen contralateral to the lesion in the following features: drug-induced dyskinesias (92%), akinesia (38%), rigidity (51%), and tremor (42%). Complications included transient dysarthria (7 patients), facial weakness (9 patients), limb weakness (1 patient), swallowing problems (4 patients) and intracerebral haemorrhage (1 patient). Thalamic DBS may improve tremor in PD and ET patients. Therefore, we enrolled fifteen patients (9 PD and 6 ET patients) with disabling tremor, unresponsive to medication. They were assessed by the United Parkinson's Disease Rating Scale (UPDRS) and the Tremor Rating Scale (for PD and ET patients, respectively). Three months after surgery, limb tremor contralateral to stimulation improved by 71% in PD patients and 76% in ET patients. Complications included transient paresthesias (all), confusional state (1 patient) and intracerebral bleed (1 patient). Unilateral medial pallidotomy safely improves some Parkinsonian symptoms contralateral to the lesion. Thalamic DBS may effectively and safely improve contralateral limb tremor in PD and ET.     

Detection of bone metastases in breast cancer by 18FDG PET: differing metabolic activity in osteoblastic and osteolytic lesions

PURPOSE: 99mTechnetium methylene diphosphonate (99mTc MDP) bone scintigraphy is currently the method of choice for the detection of bone metastases, but 18F-fluoro-deoxy-D-glucose positron emission tomography (18FDG PET) offers superior spatial resolution and improved sensitivity. We have compared 18FDG PET with 99mTc MDP bone scintigraphy in patients with skeletal metastases from breast cancer and have analyzed the data in subgroups based on radiographic characteristics of lesions. PATIENTS AND METHODS: Twenty-three women with breast cancer and confirmed bone metastases were studied with both 99mTC MDP bone scintigraphy and 18FDG PET, and the number of lesions detected and the quantitation of uptake (standardized uptake values [SUVs]) of 18FDG in osteolytic and osteoblastic metastases were compared. Survival was compared for both lytic and blastic bone metastases and for patients with high and low accumulation of 18FDG. RESULTS: 18FDG PET detected more lesions than 99mTc MDP scintigraphy (mean, 14.1 and 7.8 lesions, respectively; P < .01). However, 18FDG detected fewer bone metastases compared with 99mTc MDP scintigraphy in a subgroup of patients with osteoblastic disease (P < .05). Higher SUVs were observed for osteolytic than osteoblastic disease (mean, 6.77 and 0.95, respectively; P < .01). Survival was lower in patients with osteolytic disease compared with the remainder (P=.01). A difference in survival was not found for those patients with high SUVs (> 3.6; P=.4). CONCLUSION: 18FDG PET is superior to bone scintigraphy in the detection of osteolytic breast cancer metastases, which led to a poorer prognosis. In contrast, osteoblastic metastases show lower metabolic activity and are frequently undetectable by PET. The biologic explanation for this observation remains to be elucidated.     

Carbon-11-thymidine and FDG to measure therapy response

This study was performed to determine if PET imaging with 11C-thymidine could measure tumor response to chemotherapy early after the initiation of treatment. Imaging of deoxyriboneucleic acid biosynthesis, quantitated with 11C-thymidine, was compared with measurements of tumor energetics, obtained by imaging with 18F-fluorodeoxyglucose (FDG). METHODS: We imaged four patients with small cell lung cancer and two with high-grade sarcoma both before and approximately 1 wk after the start of chemotherapy. Thymidine and FDG studies were done on the same day. Tumor uptake was quantified by standardized uptake values (SUVs) for both tracers by the metabolic rate of FDG and thymidine flux constant (K(TdR)) using regions of interest placed on the most active part of the tumor. RESULTS: In the four patients with clinical response to treatment, both thymidine and FDG uptake markedly declined 1 wk after therapy. Thymidine measurements of SUV and K(TdR) declined by 64% +/- 15% and 84% +/- 33%, respectively. FDG SUV and the metabolic rate of FDG declined by 51% +/- 9% and 63% +/- 23%, respectively. In the patient with metastatic small cell lung cancer who had disease progression, the thymidine SUV decreased by only 8% (FDG not done). In a patient with abdominal sarcoma and progressive disease, thymidine SUV was essentially unchanged (declined by 3%), whereas FDG SUV increased by 69%. CONCLUSION: Images show a decline in both cellular energetics and proliferative rate after successful chemotherapy. In the two patients with progressive disease, thymidine uptake was unchanged 1 wk after therapy. In our limited series, K(TdR) measurements showed a complete shutdown in tumor proliferation in patients in whom FDG showed a more limited decrease in glucose metabolism.     

Central motor loop oscillations in parkinsonian resting tremor revealed by magnetoencephalography

A variety of clinical and experimental findings suggest that parkinsonian resting tremor results from the involuntary activation of a central mechanism normally used for the production of rapid voluntary alternating movements. However, such central motor loop oscillations have never been directly demonstrated in parkinsonian patients. Using magnetoencephalography, we recorded synchronized and tremor-related neuromagnetic activity over wide areas of the frontal and parietal cortex. The spatial and temporal organization of this activity was studied in seven patients suffering from early-stage idiopathic Parkinson's disease (PD). Single equivalent current dipole (ECD) analysis and fully three-dimensional distributed source solutions (magnetic field tomography, MFT) were used in this analysis. ECD and MFT solutions were superimposed on high-resolution MRI. The findings indicate that 3 to 6 Hz tremor in PD is accompanied by rhythmic subsequent electrical activation at the diencephalic level and in lateral premotor, somatomotor, and somatosensory cortex. Tremor-evoked magnetic activity can be attributed to source generators that were previously described for voluntary movements. The interference of such slow central motor loop oscillations with voluntary motor activity may therefore constitute a pathophysiologic link between tremor and bradykinesia in PD.     

Vasorelaxant effect of olprinone, an inhibitor of phosphodiesterase 3, on mesenteric small artery and vein of rabbits

An augmented synthesis of tetrahydroisoquinolines, such as salsolinol (SAL) or an increased N-methylation of these compounds has been addressed by various investigators as putative pathophysiologic mechanisms in Parkinson's disease (PD). Aim of this study was (1) to investigate putative relations between plasma levels of dopamine and R- and S-enantiomers of SAL and (2) whether these metabolic precursors of the neurotoxic N-methylated-SAL (NMSAL) are elevated in untreated "de-novo" Parkinsonian patients compared to age- and sex-matched healthy controls. Plasma levels of R- and S-SAL and dopamine did not significantly (R-SAL: p=0.61, S-SAL: p=0.51, dopamine: p=0.84) differ in both groups. Parkinsonian patients' R-SAL plasma levels were inversely related to intensity (p=0.03, r =-0.42) and duration of PD (p=0.03, r=-0.43) in contrast to S-SAL and dopamine. Dopamine levels were not associated to R-SAL (p=0.88, r2=0.0008) and S-SAL (p=0.088, r2=0.12) neither in Parkinsonian patients nor in controls. We conclude, that an upregulation of N-methylation of tetrahydroisoquinolines takes place in PD by enzymes such as neutral N-methyltransferase specific for R-SAL. The activity of this enzyme has been found elevated in parkinsonian lymphocytes. This increased N-methylation by the N-methyltransferase specific for R-SAL leads to the known augmented levels of neurotoxic R-NMSAL in Parkinsonian patients compared to controls in the cenral nervous system especially in the beginning of PD.     

Comparative clinical study of patients with Parkinson disease and essential tremor

INTRODUCTION AND OBJECTIVE: Some studies have shown that essential tremor (ET) occurs more frequently in Parkinson disease (PD) patients and opposite, suggesting these disorders are pathogenically related. To evaluate this relationship, we have compared some clinical features between patients with ET and with PD. PATIENTS AND METHODS: PD patients (N = 134) and patients with ET (N = 46), were collected from Bajo Aragon district. A diagnosis of PD was taken according to the United Kingdom Parkinson's Disease Society Brain Bank criteria. A diagnosis of ET was confirmed on the basis of Rajput et al criteria. RESULTS: A statistically significant higher number of females with ET were founded (p < 0.05). An earlier mean age at tremor onset was observed in ET patients (p < 0.0001). More than half ET patients had a positive had a positive family history of ET (p < 0.0001). Interval period between tremor onset and first medical consulting was higher in ET patients (p < 0.01). Depression was more common in PD patients (p < 0.05). CONCLUSIONS: A statistically significant differences about mean age at tremor onset, duration of illness, positive family history of ET, one side or bilateral tremor onset and frequency of depression were observed between these two disorders. The differences found in clinical features and others described previously about necropsy findings and TEP with 18F-Dopa studies, don't support the possibility that PD and ET are pathogenically related.     

Medical options for early pregnancy termination

OBJECTIVES: We sought to assess the relation between glucose metabolism, myocardial perfusion and cardiac work after orthotopic heart transplantation. BACKGROUND: The metabolic profile of the transplanted cardiac muscle is affected by the lack of sympathetic innervation, impaired inotropic function, chronic vasculopathy, allograft rejection and immunosuppressive therapy. In relation to myocardial perfusion and cardiac work, glucose metabolism has not previously been studied in heart transplant recipients. METHODS: Regional myocardial blood flow (ml.min-1.g-1) and 18F-2-fluoro-2-deoxyglucose (18FDG) uptake rate (ml.s-1.g-1) were measured after an overnight fast in 9 healthy male volunteers (mean age +/- SD 32 +/- 7 years) and in 10 male patients (mean age 50 +/- 10 years) who had a nonrejecting heart transplant, normal left ventricular function and no angiographic evidence of epicardial coronary sclerosis. Measurements were made by using dynamic positron emission tomography (PET) with 15O-labeled water and 18FDG, respectively. Heart rate and blood pressure were also measured for calculation of rate-pressure product. RESULTS: 18FDG uptake was similar in all heart regions in the patients and volunteers (intrasubject regional variably 12 +/- 8% and 16 +/- 12%, respectively, p = 0.51). Regional myocardial blood flow was similarly evenly distributed (intrasubject regional variability 14 +/- 10% and 12 +/- 8%, respectively, p = 0.67). Mean 18FDG uptake and myocardial blood flow values for the whole heart are given because no regional differences were identified. 18FDG uptake was on average 196% higher in the patients than in the volunteers (2.90 +/- 1.79 x 10(-4) vs. 0.98 +/- 0.38 x 10(-4) ml.s-1.g-1, p = 0.006). Regional myocardial blood flow and rate-pressure product were similarly increased in the patient group, but by only 41% (1.14 +/- 0.3 vs. 0.81 +/- 0.13 ml.min-1.g-1, p = 0.008) and 53% (11,740 +/- 2,830 vs. 7,689 +/- 1,488, p = 0.001), respectively. CONCLUSIONS: 18FDG uptake is homogeneously increased in normally functioning nonrejecting heart transplants. This finding suggests that glucose may be a preferred substrate in the transplanted heart. The magnitude of this observed increase is significantly greater than that observed for myocardial blood flow or cardiac work. In the patient group, the latter two variables were increased to a similar degree over values in control hearts, indicating a coupling between cardiac work load and myocardial blood flow. The disproportionate rise in 18FDG uptake may be accounted for by inefficient metabolic utilization of glucose by the transplanted myocardium or by the influence of circulating catecholamines, which may stimulate glucose uptake independently of changes in cardiac work load.     

The effect of ethanol on alcohol-responsive essential tremor: a positron emission tomography study

We used H2 15O positron emission tomography (PET) to investigate the effect of ethyl alcohol on regional cerebral blood flow in 6 patients with alcohol-responsive essential tremor and 6 age-matched control subjects. The patients were scanned while at rest and during involuntary postural tremor of the extended right arm. Normal control subjects were scanned at rest and during passive wrist oscillation of the right arm at tremor frequency. Regional cerebral blood flow associated with these conditions was measured before and after oral administration of 2 to 3 units of alcohol. The mean blood alcohol level was 35.3 +/- 20.0 mg/dl in the patient group and caused marked suppression of tremor; it was 33.9 +/- 12.9 mg/dl in the control group. Similar to previous PET studies on essential tremor patients, tremor compared with rest was associated with bilateral cerebellar activation including the cerebellar vermis. This pattern of activation differed from passive wrist oscillation where ipsilateral cerebellar activation was observed. Ethanol ingestion led to bilateral decreases of cerebellar blood flow in both tremor patients and normal subjects, and this was associated with suppression of tremor in the patients. Alcohol-associated increases of regional cerebral blood flow were observed in the inferior olivary nuclei in the patients but not in the control subjects. We conclude that alcohol-induced suppression of essential tremor is mediated via a reduction of cerebellar synaptic overactivity resulting in increased afferent input to the inferior olivary nuclei.     

Neck dissection in the treatment of cancer of major salivary glands

We investigated the use of PET and 2[18F]fluoro-2-deoxy-D-glucose (FDG) for detection and therapy control of metastatic germ cell cancer in comparison to CT. METHODS: Fifty-four PET studies were performed in addition to CT in 33 patients with histopathologically proven germ cell tumors (14 seminomas, 18 nonseminomas, 1 not classified). The scans were done either after initial diagnosis (Group 1; n = 12), within 2 wk after completion of chemotherapy (Group 2; n = 13) or 14-375 days after chemotherapy (Group 3; n = 29). PET and CT were validated either by histology (n = 19) or clinical follow-up for 182-1704 days (n = 35). Focal pathological uptake with PET was quantified using standardized uptake values (SUVs). RESULTS: PET was significantly more accurate than CT (0.86 versus 0.59; p < 0.025) for detection of residual viable tumor in Group 3. While sensitivities of PET and CT did not differ markedly, PET was significantly more specific than CT. No significant differences between PET and CT were found in Groups 1 and 2. PET scans after therapy resulted in false-negative findings in five of nine cases of Group 2 but only in two of nine cases of Group 3. False-positive PET findings occurred in three inflammatory processes. SUV of seminomas was significantly higher than in nonseminomas (p < 0.01). CONCLUSION: PET using FDG is superior to CT for assessment of residual tumor after chemotherapy of germ cell cancer and may thus have an increased effect on patient management in the future. PET must be performed at least 2 wk after completion of therapy. Further data are necessary to determine the role of FDG PET for initial staging of germ cell cancer.