FDG uptake and glucose transporter type 1 expression in lymph nodes of non-small cell lung cancer

AIMS

FDG uptake in NSCLC is related to glucose transporter type 1 (Glut-1) expression. Here, we investigated the direct causal relationship between FDG uptake and Glut-1 expression to determine the role of Glut-1 in FDG uptake by malignant and benign lymph nodes (LNs).

METHODS

Fifty-five curative lung resections in 53 NSCLC patients (male:female=36:17, age=62.0+/-11.8 years) were included. Maximum standardized uptake values (maxSUVs) of LNs in preoperative whole body FDG-PET and Glut-1 immunostaining results were compared.

RESULTS

Of 316 pathologically confirmed LNs, 12.3% (39/316) were malignant, and in malignant LNs, FDG positive LNs were no different from FDG negative LNs in terms of size (15.0+/-6.7 mm vs 10.0+/-6.1mm, p>0.05), or in terms of the proportion of LNs occupied by tumor (60.0+/-28.8% vs 39.2+/-38.4%, p>0.05), but had greater percentages of Glut-1 positive cells in tumors (74.1+/-31.8% vs 22.7+/-18.7%, p<0.01), and Glut-1 staining intensities (3.4+/-0.9 vs 1.8+/-1.3, p<0.01). FDG negative malignant LNs featured cytoplasmic Glut-1 expression and adenocarcinoma. Glut-1 staining intensities were found to be significantly correlated with the maxSUVs of malignant LNs (rho=0.516, p<0.05), but the percentages of Glut-1 positive cells in tumors were not (r=0.2072, p>0.05). Analysis of FDG positive benign LNs showed that maxSUV was not correlated with degree of follicular hyperplasia, or Glut-1 expression (p>0.05).

CONCLUSIONS

Intense Glut-1 immunoreactivity was found to be proportionally related to the degree of FDG uptake by malignant LNs in NSCLC. However, the finding that Glut-1 expression in lymphoid hyperplasia showed no correlation with FDG uptake in benign LNs requires further investigation.

Cerebellar hypermetabolism in paraneoplastic cerebellar degeneration

A 51 year old man with paraneoplastic cerebellar degeneration from gastric adenocarcinoma showed cerebellar hypermetabolism and increased perfusion on brain FDG-PET scan and SPECT during the acute stage of his illness. The patient underwent subtotal gastrectomy. The intensity of the hypermetabolism had decreased markedly on follow-up FDG-PET 3 months later following two cycles of chemotherapy. We suggest that the cerebellar hypermetabolism may have been due to an acute inflammatory process associated with an immunological reaction.

The clinical and electrophysiological characteristics of temporal lobe epilepsy with normal MRI

Background and Purpose

To identify the clinical and electrophysiological characteristics of temporal lobe epilepsy (TLE) with normal MRI.

Methods

Twenty-six patients were diagnosed with TLE with normal MRI by stereotaxically implanted depth electrode EEG (SEEG) and quantitative MRI. We divided the patients into anterior or diffuse temporal groups by interictal EEG, into localized, hemispheric or non-lateralized onset groups by ictal scalp EEG, and into focal or regional onset groups by SEEG. The clinical and electrophysiological characteristics were compared with those of 25 TLE patients with unilateral hippocampal atrophy (HA) on MRI. Four patients of TLE with unilateral HA also underwent SEEG.

Results

Patients in the normal MRI group showed a significantly higher frequency of secondarily generalization (225±235, median 160 vs 68±48, median 50, p<0.05), shorter duration of epilepsy (16±10 yrs vs 25.9±7.8 yrs, p<0.001), and less favorable surgical outcome (50% vs 88%, p <0.05) than patients in the unilateral HA group. Also, patients with normal MRI frequently showed diffuse temporal (50% vs 20%, p<0.05) discharges on interictal EEG. The ictal seizure patterns of patients with normal MRI showed less localization to one temporal lobe on scalp EEG (28% vs 65%, p<0.001) and a higher frequency of regional onset on SEEG (68% vs 8%, p<0.001) than patients with unilateral HA.

Conclusions

The characteristics of TLE with normal MRI compared with TLE with unilateral HA are shorter duration of epilepsy, higher frequency of secondarily generalization, and less favorable surgical outcome, suggesting wider areas of temporal lobe involved compared with patients with unilateral HA.

Pattern of glucose hypometabolism in frontotemporal dementia with motor neuron disease

Frontotemporal dementia (FTD) often coexists with motor neuron disease (MND). To characterize glucose hypometabolism in patients with FTD with MND (FTD/MND), the authors compared the glucose metabolism of 8 patients with FTD/MND with that of 29 patients with FTD. All of the patients with FTD/MND showed glucose hypometabolism only in the frontal area, whereas most patients with FTD had hypometabolism in the frontal and temporal areas. FTD/MND also showed a more symmetric pattern of glucose hypometabolism than FTD.

Patient satisfaction after surgery for trigeminal neuralgia--development of a questionnaire

OBJECTIVE

This project aimed to prepare a self complete patient satisfaction survey for patients who have undergone surgery for trigeminal neuralgia and then assess its reproducibility, validity and acceptability in one centre.

METHODS

The questionnaire, for initial use in patients who had undergone posterior fossa surgery for trigeminal neuralgia, was designed after a systematic review of the surgical literature had been performed and discussions held at the US and UK Trigeminal Neuralgia Support group meetings. It underwent several changes after input from neurosurgeons, patients, copywriter and statistician and finally contained 44 questions, the SF12, Hospital Anxiety and Depression Scale (HAD), Brief Pain Inventory (BPI) and McGill Pain questionnaire (MPQ). From the total number of 413 patients in the database of one centre the questionnaire was sent with a covering letter to 305 patients, the rest had died (25), were lost to follow up (26) or did not meet the inclusion criteria (56). One patient had bilateral PSR. The completed questionnaires were evaluated by an independent physician, neurosurgeon and patient. A repeat questionnaire was sent to 10% of the patients to check reproducibility.

RESULTS

The questionnaires were well completed with a final response rate of 92%. It appeared to be highly acceptable and reproducible but needed adjustment to improve its validity before being used in other centres and for all surgical procedures. A new questionnaire is proposed which could be used on an annual basis.

CONCLUSIONS

A questionnaire has been developed for use in patients who have undergone surgical management for trigeminal neuralgia and which is acceptable to patients.

Correlation of ventricular asymmetry with metabolic asymmetry in frontotemporal dementia

BACKGROUND AND PURPOSE

The clinical presentation of frontotemporal dementia (FTD) is often asymmetrical in terms of both its clinical features and atrophy on MRI. Asymmetry in the lateral ventricle size on structural neuroimaging in FTD patients may have clinical significance. However, this has not been systematically investigated yet. This study compares the ventricular asymmetry seen on MRI with that of the asymmetric glucose metabolism using FDG-PET in patients with FTD.

METHODS

Nineteen FTD patients who underwent both brain MRI and FDG-PET were retrospectively selected. As control groups, 23 and 11 age and sex-matched healthy normal subjects underwent either brain MRI or FDG-PET, respectively. The ventricular asymmetry index (VAI) was obtained in two ways: by visual rating (VAI-V) and by measuring the lateral ventricular volumes (VAI-ROI). The hemispheric asymmetry of the glucose metabolism on FDG-PET (MAI) was assessed in three ways: 1) by visual rating (MAI-V), 2) by counting the FDG activity of each hemisphere on normalized and smoothed PET images (MAI-ROI) and 3) by counting the number of voxels with significant hypometabolism based on statistical parametric mapping results (MAI-SPM).

RESULTS

The VAIs on MRI (VAI-V and VAI-ROI) were highly correlated, as were the MAIs (MAI-V, MAI-ROI, and MAI-SPM) on FDG-PET. More importantly, the VAIs on MRI and the MAIs on FDG-PET showed high correlation.

CONCLUSIONS

Ventricular asymmetry in FTD patients was common (78.9%) and there was a high correlation between the ventricular structural asymmetry and the hemispheric metabolic asymmetry. Therefore, it would be reasonable to interpret that the hemisphere with larger ventricle on MRI in FTD patients is undergoing a more active degenerative process.

Glucose metabolism in early onset versus late onset Alzheimer's disease: an SPM analysis of 120 patients

The aims of this cross-sectional study were (i) to compare the overall glucose metabolism between early onset and late onset Alzheimer's disease in a large sample of patients; and (ii) to investigate the pattern of glucose metabolism as a function of dementia severity in early onset versus late onset Alzheimer's disease, using a statistical parametric mapping (SPM) analysis. Subjects consisted of four groups: 74 patients with early onset Alzheimer's disease, 46 patients with late onset of the disease, and two control groups age matched to each patient group. All the subjects underwent 2-[(18)F]fluoro-2-deoxy-d-glucose (FDG)-PET under the same scanning conditions. Severity of dementia was rated with the Clincial Dementia Rating (CDR). Voxel-based SPM99 was used for statistical analyses. Overall glucose hypometabolism of early onset Alzheimer's disease patients was much greater in magnitude and extent than that of late onset patients, though both groups were similar in dementia severity: the early onset group showed more severe hypometabolism in parietal, frontal and subcortical (basal ganglia and thalamus) areas. When the decline of glucose metabolism was compared as a function of CDR stage, the slope was steeper in early onset than in late onset Alzheimer's disease. The rapid decline occurred at CDR 0.5-1 in the early onset group, whereas similar changes occurred at CDR 2-3 in the late onset group. The greater hypometabolism in early onset than in late onset patients is required to reach the same severity of dementia, probably reflecting greater functional reserve in younger than in older subjects. Alternatively, the metabolic decline curve suggests that the early onset patients may take a more rapid course in the reduction of glucose metabolism than the late onset patients.

Primary malignant fibrous histiocytoma extending into spinal canal through intervertebral foramina

A 60-year-old man was referred to us because of gradual-onset radiculopathy in his left leg for 2 months. Magnetic Resonance Imaging (MRI) of the lumbar spine demonstrated a relatively homogeneous huge mass in the left paravertebral area from L1 to L3 (Fig. 1A, B). Axial MRI scan (Fig. 1C) confirmed the extension of the tumour into the adjacent spinal canal through the neural foramina, forming an extradural mass, which resulted in the compression of both the dural sac and the nerve roots. The patient was operated on by a staged-resection. First, a left retroperitoneal approach was performed for the paraspinal mass. The tumour appeared brown to tan in color and was moderately firm. Nine days after his first operation, the patient underwent a resection of the intraspinal/extradural tumour by a posterior approach. After the left L1-2 hemilaminectomy was performed, the extradural tumour was easily identified, dissected, and completely removed. Microscopically, it was a highly cellular tumour composed of anaplastic cells assuming a gigantic size with bizarre nuclei, which were admixed with inflammatory cells (Fig. 1D). The tumour cells were immunohistochemically characterized by positive staining for vimentin confirming its mesenchymal origin, and CD68 consistent with histiocyte-like qualities (Fig. 1E, F). A diagnosis of inflammatory malignant fibrous histiocytoma (MFH) could be made. Postoperatively, the patient made an uneventful recovery and received radiotherapy as an adjuvant therapy.

Expression of hMLH1 is inactivated in the gastric adenomas with enhanced microsatellite instability

Microsatellite instability (MSI) and frameshift mutations in the genes containing coding nucleotide repeats have been reported in a subset of gastric adenomas, however the inactivation profiles of DNA mismatch repair genes in MSI-positive gastric adenomas have not been characterized. To address the origin of MSI in gastric adenomas, expressions of hMLH1 and hMSH2 were explored in 86 gastric adenomas. Gastric carcinomas, of which 16 were MSI-positive and 22 MSI-negative, were used as controls. MSI was found in 15 (17%) of gastric adenomas. Absent or decreased hMLH1 expression by immunohistochemistry was noted in most of the MSI-positive adenomas (13/15, 87%) and carcinomas (14/16, 88%), and all of these tumours showed methylation of the hMLH1 gene promoter. In contrast, rare inactivation of hMLH1 expression was found in MSI-negative adenomas (3/71, 4%) and carcinomas (2/22, 9%). Intense expression of hMSH2 gene product was observed in most of the gastric adenomas and carcinomas regardless of MSI status. These findings indicate that the inactivation of hMLH1 gene expression by promoter methylation is an early event and might be the origin of MSI-positive gastric adenomas.

Teratoid hepatoblastoma: multidirectional differentiation of stem cell of the liver

Hepatoblastoma is the most common malignant hepatic neoplasm of childhood, showing a wide spectrum of epithelial and mesenchymal components. Teratoid hepatoblastoma, which reveals multiple lines of tissue differentiation such as mucinous epithelium, melanin pigment, endocrine differentiation, glial and mesenchymal components, has rarely been observed. We report a case of teratoid hepatoblastoma in a 22-month-old girl. She had been diagnosed with hepatoblastoma through percutaneous needle biopsy of the liver and treated with 10 chemotherapy cycles of epirubicin, VP-16 and cisplatin and with hepatic artery embolization. After 10 months, an extended left lobectomy was performed. Grossly, a multinodular, partly well-demarcated, solid mass (7 x 5 cm) with dense fibrosis and focal cystic change occupied almost the entire specimen. There was extensive necrosis due to preoperative treatment. Microscopically, the tumor showed multiple lines of differentiation, which was composed of embryonal, fetal hepatocytes and mesenchymal elements with numerous foci of osteoid. There were also other components showing endodermal, neural, melanocytic and endocrine differentiation. These teratoid components were considered relatively resistant to preoperative chemotherapy, in contrast to extensive necrosis of both embryonal and fetal hepatocytes. These teratoid features of hepatoblastoma are considered to be a multidirectional differentiation of the small epithelial cells or stem cells of the tumor.

Ictal hyperperfusion of cerebellum and basal ganglia in temporal lobe epilepsy: SPECT subtraction with MRI coregistration

The ictal hyperperfusion (compared with the interictal state) of the cerebellum and basal ganglia has not been investigated systematically in patients with temporal lobe epilepsy (TLE). Their ictal perfusion patterns were analyzed in relation to temporal and frontal hyperperfusion during TLE seizures using SPECT subtraction.

METHODS

Thirty-three TLE patients had interictal and ictal SPECT, video-electroencephalographic (EEG) monitoring, and volumetric MRI. SPECT subtraction with MRI coregistration was performed using commercial software. The presence of ictal hyperperfusion was determined in the ipsilateral and contralateral temporal lobe, frontal lobe, cerebellum, and basal ganglia.

RESULTS

All patients showed ictal hyperperfusion in the temporal lobe of seizure origin. Vermian cerebellar hyperperfusion (CH) was observed in 26 patients (78.8%) and hemispheric CH was found in 25 (75.8%). Compared with the side of the epileptogenic temporal lobe, there were 7 patients with ipsilateral hemispheric CH (28.0%), 15 with contralateral hemispheric CH (60.0%), and 3 with bilateral hemispheric CH (12.0%). CH was observed more frequently in patients with additional frontal hyperperfusion (14/15, 93.3%; 2 ipsilateral to the seizure focus, 10 contralateral, and 2 bilateral) than in patients without frontal hyperperfusion (11/18, 61.1%). Among 18 patients with temporal hyperperfusion without frontal hyperperfusion, 11 patients showed hemispheric CH (5 ipsilateral to seizure focus, 5 contralateral, 1 bilateral). Hyperperfusion in the basal ganglia (BGH) was seen in 11 of the 15 patients with temporal and frontal hyperperfusion (73.3%) and in 11 of the 18 with only temporal hyperperfusion (61.1%). In 17 patients with unilateral BGH (13 ipsilateral to the seizure focus, 4 contralateral), CH contralateral to the BGH was observed in 14 (82.5%), CH ipsilateral to the BGH was found in 2 (11.8%), and CH bilateral to the BGH was found in 1 (5.9%).

CONCLUSION

During TLE seizures, hemispheric CH occurred not only in contralateral but also in ipsilateral or bilateral cerebellar hemispheres to the side of seizure origin. Although temporal lobe origin seizures associated with additional frontal hyperperfusion produced more frequent hemispheric CH, seizures showing only temporal hyperperfusion without frontal hyperperfusion could produce BGH and CH. To determine the side of hemispheric CH, the most important factor appears to be the side of BGH, not the side of seizure origin.

A simple and efficient in vitro method for metabolism studies of radiotracers

In vitro metabolism of acetylcholinesterase inhibitors containing 3-[(18)F]fluoromethylbenzyl- ([(18)F]1) and 4-[(18)F]fluorobenzyl-piperidine moieties ([(18)F]2) was studied and compared with the in vivo metabolism. Defluorination of the [(18)F]1 mainly occurred to generate [(18)F]fluoride ion both in vitro and in vivo. In contrast, the [(18)F]2 was converted into an unknown polar metabolite in both metabolism methods and another metabolite, 4-[(18)F]fluorobenzoic acid in vitro. These results demonstrated that the in vitro method can be used to predict the in vivo metabolism of both radiotracers.

Vanilloid and isovanilloid analogues as inhibitors of methionyl-tRNA and isoleucyl-tRNA synthetases

As aminoacyl adenylate surrogates, a series of methionyl and isoleucyl phenolic analogues containing bioisosteric linkers mimicking ribose have been investigated. Inhibition of synthesized compounds to the aminoacylation reaction by the corresponding Escherichia coli methionyl-tRNA and isoleucyl-tRNA synthetases indicated that 18 was found to be a potent inhibitor of isoleucyl-tRNA synthetase. A molecular modeling study demonstrated that in 18, isovanillate and hydroxamate served as proper surrogates for adenine and ribose in isoleucyl adenylate, respectively.

Ester and hydroxamate analogues of methionyl and isoleucyl adenylates as inhibitors of methionyl-tRNA and isoleucyl-tRNA synthetases

The structure activity relationship on a series of ester and hydroxamate analogues of methionyl and isoleucyl adenylate has been investigated through introducing linkers between the 1'-position of ribose and adenine surrogates as methionyl-tRNA, and isoleucyl-tRNA synthetase inhibitors, respectively. The results indicate that ester analogue 23 was found to be a potent inhibitor of Escherichia coli methionyl-tRNA synthetase, and its interaction with the active site was proposed by a molecular modeling study.

Anti-invasive activity of torilin, a sesquiterpene compound isolated from Torilis japonica

Torilin is a sesquiterpene compound purified from Torilis japonica (Umbelliferae). We have previously reported that torilin has a potent anti-angiogenic activity both in vivo and in vitro. In the present study, we investigated the anti-invasive activity of torilin, and interestingly found that torilin completely blocked intravasation of HT1080 human fibrosarcoma cells inoculated on the chorioallantoic membrane (CAM) of chick embryo. In addition, torilin decreased the attachment of HT1080 cells to confluent human umbilical vein endothelial cells (HUVECs) at non-toxic concentration. In in vitro transwell invasion model, 25 microM torilin also significantly inhibited HT1080 cell invasion in a time-dependent manner. Activity and expression of matrix metalloproteinase-9 (MMP-9) that is very important in tumor invasion and metastasis were also decreased by torilin treatment, indicating that the inhibitory effect of torilin on invasion of HT1080 cells may result from decreasing activity and expression of MMP-9. Therefore, it is possible that torilin may decrease metastatic potential of tumor cells through inhibiting their attachment to endothelial cells and intravasation to blood vessels. Taken together, torilin may have a strong activity to suppress tumorigenesis by inhibition of tumor invasion.

Brain tumor imaging with 99mTc-tetrofosmin: comparison with 201Tl, 99mTc-MIBI, and 18F-fluorodeoxyglucose

The purpose of the present study was to assess the ability of technetium-99m-tetrofosmin (99mTc-TF) to predict tumor malignancy and to compare its uptake with that of thallium-201 (201Tl), technetium-99m-hexakis-2-methoxyisobutyl isonitrile (99mTc-MIBI) and fluorine-18-fluorodeoxyglucose (18F-FDG) in brain tumors. 99mTc-TF single-photon emission computed tomography (SPECT) imaging was performed in 22 patients with brain tumors and 3 healthy controls. Some of the patients underwent 201Tl (n = 12) and 99mTc-MIBI SPECT (n = 14) and 18F-FDG positron emission tomography (PET) (n = 12). The radioactivity ratio of tumor to contralateral normal tissue (T/N) and the ratio of tumor to contralateral white matter (T/WM) were calculated in SPECT and PET images, respectively. In healthy controls, 99mTc-TF uptake was seen only in scalp, in the choroid plexus and pituitary gland, but not in normal cerebral parenchyma. TF T/N in low grade gliomas (2.8+/-0.4) was significantly lower than that in high grade gliomas (22.5+/-29.8) and malignant non-gliomas (8.3+/-2.8) without overlap of values (p = 0.003 and p = 0.014, respectively). TF T/N was significantly correlated with MIBI T/N (p = 0.92, p = 0.001), Tl T/N (p = 0.72, p = 0.017), and FDG T/WM (p = 0.65. p = 0.031). There was an excellent agreement between TF T/N and MIBI T/N values on linear regression analysis (MIBI T/N = -0.63+/-0.97 x TF T/N). These preliminary results indicate that SPECT imaging with 99mTc-TF may be useful for the non-invasive grading of brain tumors. They also suggest that 99mTc-TF and 99mTc-MIBI may accumulate in brain tumors by a similar mechanism or in relation to a similar process of tumor cell proliferation.

Left main coronary artery aneurysm with chronic total occlusion of both left coronary arteries in a young athlete

Aneurysms of the left main coronary arteries are found in 0.1% of angiograms. This case involves an athlete with a left main coronary artery aneurysm, which was combined with chronic total occlusion of the proximal left anterior descending and proximal left circumflex coronary arteries. The extraordinary clinical presentation in this patient may be associated with good coronary collaterals, which may have developed in the patient in response to chronic total occlusion of the coronary artery by the aneurysm, and repeat myocardial hypoxia during high levels of performance as a soccer player.

N-butyl-2-cyanoacrylate pulmonary embolism after endoscopic injection sclerotherapy for gastric variceal bleeding

PURPOSE

The purpose of this work was to describe the radiologic and clinical manifestations of n-butyl-2-cyanoacrylate pulmonary embolism (PE) after endoscopic injection sclerotherapy (EIS) for gastric variceal bleeding.

METHOD

From 1992 to 1999, the medical records of 140 patients who had undergone EIS using n-butyl-2-cyanoacrylate were reviewed for identification of respiratory symptoms and amount of injection, and their pre- and postprocedure chest radiographs were reviewed to identify PE. In patients with PE, pre- and postprocedure chest radiographs (6/6), chest CT scans (3/6), lung perfusion scans (3/6), and follow-up chest radiographs (6/6) were analyzed retrospectively.

RESULTS

Radiographically evident PE was observed in 6 (4.3%) of 140 patients. In comparison with patients without emboli, these patients received a higher mean volume of injection (4.2 vs. 1.8 ml) (p = 0.0011). Four of the six patients with pulmonary emboli had respiratory symptoms. Chest radiographs and CT scans showed unusual tubular or nodular, radiopaque pulmonary emboli along the pulmonary vessels. Multiple peripheral, wedge-shaped, subsegmental perfusion defects were seen on perfusion lung scans. In five of six patients, the radiographic abnormalities showed complete or partial resolution. There were no fatalities directly associated with PE.

CONCLUSION

Radiographically evident PEs are uncommonly observed following EIS and appear to be more common in patients receiving a higher volume of liquid acrylate. Affected patients were either mildly symptomatic or asymptomatic, and there were no direct fatalities of this complication.

Correlation of temporal lobe glucose metabolism with the Wada memory test

PURPOSE

The goal of the present study was to examine the relationship of 18F-fluorodeoxyglucose positron emission tomography (FDG-PET) and the Wada memory test in lateralizing memory dominance and epileptic focus.

METHODS

FDG-PET and the Wada test were performed in 18 patients with temporal lobe epilepsy (TLE). The asymmetry indices of FDG-PET (PET-AI) were calculated in mesial, polar, anterolateral, midlateral, and posterolateral regions of the temporal lobe, and those of Wada memory test (Wada-AI) were obtained as well.

RESULTS

The Wada-AI was significantly correlated with PET-AI in mesial (r = 0.67, p = 0.003), polar (r = 0.55, p = 0.019), anterolateral (r = 0.55, p = 0.019), and midlateral (r = 0.51, p = 0.031) regions of the temporal lobe. However, after a linear regression analysis, PET-AI of only the mesial temporal region was significantly correlated with Wada-AI (p = 0.008). Wada-AI could correctly lateralize the seizure focus in 90% of the left TLE and 75% of the right TLE patients. The PET-AI of the mesial temporal region showed the highest sensitivity of seizure lateralization (80% of left TLE and 87.5% of right TLE). PET-AI of other temporal regions had lower sensitivities (50-80% of left TLE, 20-75% of right TLE). One or two patients showed false seizure lateralization by PET-AI on each temporal region.

CONCLUSIONS

Although FDG-PET hypometabolism is observed at both mesial and lateral regions of the temporal lobe in mesial TLE, mesial temporal region appeared to be a dominant and leading area for lateralizing Wada memory dominance and epileptic focus.

Effect of ginseng total saponin on extracellular dopamine release elicited by local infusion of nicotine into the striatum of freely moving rats

We investigated the effect of ginseng total saponin (GTS) on nicotine-induced dopamine (DA) release in the striatum of freely moving rats using an in vivo microdialysis technique. In order to further characterize the mechanism by which GTS affects DA release, the effect of GTS on K(+)-induced DA release was also examined. Local infusion of nicotine (1, 5, and 10 mM) into the striatum produced a dose-dependent increase in extracellular DA in dialysate samples (maximal response = 154.0 +/- 10.8%, 308.1 +/- 55.7%, and 499.9 +/- 77.9% over basal levels, respectively). GTS (100 mg/kg i.p.) had no effect on basal levels of extracellular DA. However, GTS inhibited maximal DA release induced by intrastriatal infusion of nicotine (1, 5, and 10 mM) by 35.3%, 36.6%, and 58.5%, respectively. Intra-striatal infusion of high K+ solution (100 mM) produced an increase in extracellular DA in the striatum (maximal response = 796.6 +/- 98.8% over basal levels). However, GTS had no effect on the K(+)-induced increase in extracellular DA. The present study demonstrated that GTS inhibited striatal DA release stimulated by local infusion of nicotine. This may reflect the blocking effect of GTS on the striatum-related behavior induced by nicotine as well as other psychostimulants. The results also suggest that GTS may act on presynaptic nicotinic acetylcholine receptors or receptor-operated Na+ channels in dopaminergic nerve terminals, but not on voltage-sensitive ion channels.

Synthesis and biological evaluation of 1-(4-[18F]fluorobenzyl)-4-[(5,6-dimethoxy-1-oxoindan-2-yl)methyl]piperidine for in vivo studies of acetylcholinesterase

We synthesized and evaluated 1-(4-fluorobenzyl)-4-[(5,6-dimethoxy-1-oxoindan-2-yl)methyl]piperidine (4-FDP), which is an analog of donepezil. The 4-[(18)F]FDP was prepared by reductive alkylation of debenzylated donepezil with 4-[(18)F]fluorobenzaldehyde in high radiochemical yield (decay-corrected, 40-52%) and with high effective specific activity (30-38 GBq/micromol). Tissue distribution studies in mice demonstrated nonspecific distribution of the 4-[(18)F]FDP in brain regions, suggesting that this radioligand may not be a suitable agent for in vivo studies of acetylcholinesterase (AChE), despite its potent in vitro biological activity.

Development of a miniature scintillation camera using an NaI(Tl) scintillator and PSPMT for scintimammography

We have developed a small scintillation camera dedicated to breast imaging and have evaluated the performance of the system. In order to increase the limited field of view (FOV) determined by the size of a position-sensitive photomultiplier tube (PSPMT), the imaging characteristics of a diverging hole collimator (DHC) were also investigated. The small scintillation camera system consists of an NaI(Tl) crystal (60 mm x 60 mm x 6 mm) coupled to a Hamamatsu R3941 PSPMT, a resistor chain circuit, preamplifiers, nuclear instrument modules, an analogue to digital converter and a PC for control and display. The intrinsic energy resolution of the system was 12.9% FWHM at 140 keV. The spatial resolution was measured using a line-slit mask and 99mTc point sources and was 3.1 mm FWHM. The intrinsic sensitivity of the system was approximately 162 counts/s kBq(-1). The DHC made it possible to image a larger FOV (75 x 75 mm2 at the surface of collimator) than a parallel-hole collimator (60 x 60 mm2). The system sensitivity obtained using the DHC gradually decreased with distance (3% at 1 cm, 6% at 2 cm and 9% at 3 cm). The results demonstrate that the system developed in this study could be utilized clinically to image malignant breast tumours. A DHC can be employed to expand the FOV of the system confined by the size of PSPMT with a modest compromise in the performance of the system.

Sequence-specific DNA recognition by the Myb-like domain of plant telomeric protein RTBP1

We have identified a rice gene encoding a DNA-binding protein that specifically recognizes the telomeric repeat sequence TTTAGGG found in plants. This gene, which we refer to as RTBP1 (rice telomere-binding protein 1), encodes a polypeptide with a predicted molecular mass of 70 kDa. RTBP1 is ubiquitously expressed in various organs and binds DNA with two or more duplex TTTAGGG repeats. The predicted protein sequence includes a single domain at the C terminus with extensive homology to Myb-like DNA binding motif. The Myb-like domain of RTBP1 is very closely related to that of other telomere-binding proteins, including TRF1, TRF2, Taz1p, and Tbf1p, indicating that DNA-binding domains of telomere-binding proteins are well conserved among evolutionarily distant species. To obtain precise information on the sequence of the DNA binding site recognized by RTBP1, we analyzed the sequence-specific binding properties of the isolated Myb-like domain of RTBP1. The isolated Myb-like domain was capable of sequence-specific DNA binding as a homodimer. Gel retardation analysis with a series of mutated telomere probes revealed that the internal GGGTTT sequence in the two-telomere repeats is critical for binding of Myb-like domain of RTBP1, which is consistent with the model of the TRF1.DNA complex showing that base-specific contacts are made within the sequence GGGTTA. To the best of our knowledge, RTBP1 is the first cloned gene in which the product is able to bind double-stranded telomeric DNA in plants. Because the Myb-like domain appears to be a significant motif for a large class of proteins that bind the duplex telomeric DNA, RTBP1 may play important roles in plant telomere function in vivo.

Anti-angiogenic activity of torilin, a sesquiterpene compound isolated from Torilis japonica

Torilin is a sesquiterpene compound purified from fruits of Torilis japonica (Umbelliferae). In this study, we demonstrated the anti-angiogenic activity of torilin using in vivo and in vitro assay systems. Torilin decreased both neovascularization of chick embryos in the chorioallantoic membrane assay and basic fibroblast growth factor-induced vessel formation in the mouse Matrigel plug assay. Torilin also reduced the proliferation and tube formation of human umbilical vein endothelial cells. In addition, the concentrated conditioned media obtained from torilin-treated HepG2 human hepatoblastoma cells blocked the angiogenic activation of torilin-untreated concentrated conditioned media, indicating that torilin may have an inhibitory effect on tumor-induced angiogenesis. To determine what molecules were involved in the anti-angiogenic activity, we examined the expression of hypoxia-inducible angiogenic factors in torilin-treated HepG2 cells. Torilin significantly down-regulated the expression of hypoxia-inducible vascular endothelial growth factor and insulin-like growth factor-II. Taken together, our data suggest that torilin may be a strong angiogenic inhibitor with the ability to decrease tube formation of vascular endothelial cells and to reduce expression of angiogenic factors of tumor cells.

Preclinical impairment of the striatal dopamine transporter system in sporadic olivopontocerebellar atrophy: studied with [(123)I]beta-CIT and SPECT

We investigated whether the dopamine (DA) transporter system is impaired in sporadic olivopontocerebellar atrophy (sOPCA) patients without clinical parkinsonism using the DA transporter radiotracer [(123)I]beta-CIT [2beta-carboxymethoxy-3beta-(4-iodophenyl)tropane] and single-photon emission computed tomography (SPECT). SPECT scans were acquired in 9 patients with sOPCA, 7 multiple system atrophy (MSA) patients with parkinsonism (MSA-P), and 7 age-matched healthy controls 20-24 h after the intravenous injection of [(123)I]beta-CIT. [(123)I]beta-CIT-specific binding in the striatum was determined as the radioactivity ratio of the striatum to the occipital cortex (specific binding ratio, SBR). In patients with sOPCA and MSA-P, SBRs in the right and left striatum and the mean SBR were significantly lower than those in controls (p < 0.05). The mean SBRs in patients with sOPCA and MSA-P were reduced to 69.0 and 60.7% of the control mean, respectively. However, there was no significant difference in SBRs between sOPCA and MSA-P patients. In sOPCA patients, the mean SBR was significantly correlated with the score of the clinical cerebellar function scale (r = -0.670, p = 0.024). These results indicate that even in the absence of clinical parkinsonism, the striatal dopaminergic system may be impaired in sOPCA. The DA transporter loss in sOPCA serves as another clue for sOPCA being a part of the spectrum of MSA.

Broad specificity in binding of NIPP-1, nuclear inhibitor of protein phosphatase-1, to PP1 isoforms in vivo

Protein phosphatase type-1 (PP1), one of the most abundant Ser/Thr protein phosphatases, plays a central role in the regulation of various cell functions. Almost all the PP1 molecules exist as holoenzymes in vivo consisting of a catalytic subunit (PP1C) and a variable regulatory subunit that regulates substrate specificity and/or subcellular localization. In order to clarify fine regulation of PP1, we overexpressed a nuclear inhibitor of PP1 (NIPP-1) in a Flag-tagged form in mammalian cells. The Flag-tagged NIPP-1 was found to be immunoprecipitated with three isoforms of PP1C, namely, PP1alpha, PP1gamma1, and PP1delta with a similar efficiency, suggesting that NIPP-1 makes a complex with the PP1C through the region conserved among the three isoforms. These results suggested that NIPP-1 can be involved in the regulation of various PP1 holoenzymes in vivo.

Modulatory effect of ginseng total saponin on dopamine release and tyrosine hydroxylase gene expression induced by nicotine in the rat

Several studies have demonstrated that behavioral activation induced by psychostimulants is prevented by ginseng total saponin (GTS), which has been known to act on the central dopaminergic system. In an attempt to investigate whether the effect of GTS is through its inhibitory action on the elevated dopaminergic transmission, we examined the effect of GTS on nicotine-induced dopamine (DA) release in the nucleus accumbens (NA) of freely moving rats using in vivo microdialysis. Systemic injection of nicotine (3 mg/kg; i.p.) produced a mild increase in extracellular DA of dialysates samples in the NA (132+/-13% over basal levels at the peak). GTS (100 mg/kg; i.p.) had no effect on resting levels of extracelluar DA. However, an increase in accumbens DA release produced by systemic nicotine was completely blocked by systemic pre-treatment with GTS (100 mg/kg; i.p.). In addition, the effect of GTS on nicotine-induced tyrosine hydroxylase (TH) and immediate early gene expression in ventral tegmental area (VTA) or NA regions was examined. A single injection of nicotine increased TH mRNA level at VTA region. GTS, which did not affect the basal TH mRNA expression, attenuated nicotine-induced TH mRNA expression. Nicotine slightly increased both c-fos and c-jun mRNA level and GTS, which did not affect the basal c-fos and c-jun mRNA expression, further enhanced nicotine-induced c-fos and c-jun mRNA level at both VTA and NA regions. Our results suggest that GTS may have an inhibitory action against nicotine-induced DA release in NA region and TH mRNA expression in VTA region. GTS may exert an potentiative effect on both c-fos and c-jun mRNA expression at NA region through inhibiting the release of DA in NA.

Improved detection of individual nodal involvement in squamous cell carcinoma of the esophagus by FDG PET

Because both the number and location of metastatic lymph nodes and the N stage influence survival in esophageal cancer, accurate noninvasive evaluation of individual lymph node groups for the presence of metastasis is essential for therapeutic planning. Therefore, we investigated the accuracy of FDG PET for evaluating individual lymph groups in esophageal cancer patients and compared the results with those of CT and endoscopic sonography (ES).

METHODS

Sixty-one consecutive patients with histologically proven primary esophageal carcinoma were studied prospectively with FDG PET. Thirteen patients who were treated nonsurgically were excluded from data analysis. The remaining 48 patients underwent esophagectomy and lymph node dissection. All 48 patients underwent CT scanning, including the lower neck, thorax, and upper abdomen, with intravenous administration of contrast medium. ES was performed in 45 of the patients but was incomplete in 12 patients because of esophageal stenosis. The accuracies of FDG PET, CT, and ES were compared with histologic findings.

RESULTS

During surgery, a total of 382 lymph node groups were dissected in 48 patients, of which 100 node groups in 32 patients were malignant on histologic examination. For assessing metastasis to individual groups, FDG PET showed 57% sensitivity, 97% specificity, and 86% accuracy, whereas CT showed 18% sensitivity (P < 0.0001), 99% specificity (P = 0.033), and 78% accuracy (P = 0.003). For N staging, FDG PET was correct in 83% (40/48) of the patients, whereas CT and ES were correct in 60% (29/48; P = 0.006) and 58% (26/45; P = 0.003), respectively.

CONCLUSION

FDG PET is more accurate than is CT or ES for evaluating metastasis to individual lymph node groups and for N staging in esophageal cancer and thus may be helpful in determining the therapeutic plan.

Syntheses and biological evaluation of (18)F-labeled 3-(1-benzyl-piperidin-4-yl)-1-(1-methyl-1H-indol-3-yl)propan-1-ones for in vivo mapping of acetylcholinesterase

We synthesized novel (18)F-labeled acetylcholinesterase (AChE) inhibitors, 3-[1-(3- and 4-[(18)F]fluoromethylbenzyl)piperidin-4-yl]-1-(1-methyl-1H-i ndol-3-yl )propan-1-ones ([(18)F]1 and [(18)F]2) and 3-[1-(4-[(18)F]fluorobenzyl)piperidin-4-yl]-1-(1-methyl-1H-i ndol-3-yl )propan-1-one ([(18)F]3) in high yields (decay-corrected, 25%-40%) and with high effective specific activities (>37 GBq/micromol). Tissue distribution studies of the [(18)F]1 and the [(18)F]3 in mice showed the nonspecific bindings in brain regions, with metabolic defluorination of the [(18)F]1. The result suggests that these radioligands may not be suitable agents for in vivo mapping of AChE, despite their potent in vitro anti-AChE activities.

Increased expression of NIPP-1 mRNA correlates positively with malignant phenotype in rat hepatomas

In order to elucidate an involvement of protein phosphatase type 1 (PP1) in the malignant transformation, we have isolated rat cDNA for NIPP-1, a nuclear inhibitor for PP1. Rat NIPP-1 protein conserved the PP1 binding domain and the nuclear targeting sequence. The mRNA was ubiquitously expressed with the highest expression in bone marrow and thymus. The rat NIPP1 mRNA levels were slightly, if at all, increased in some primary hepatomas, and significantly increased in rat ascites hepatomas. The levels of NIPP-1 mRNA were closely correlated with malignant phenotype of rat ascites hepatomas, suggesting that NIPP-1 is tightly linked to malignant phenotype in hepatomas.

Focal cortical dysplasia: comparison of MRI and FDG-PET

PURPOSE

The purpose of this work was to compare the use of MRI and [18F]fluorodeoxyglucose (FDG) positron emission tomography (PET) in the diagnosis of focal cortical dysplasia (FCD).

METHOD

Nineteen patients with surgically proven FCD were analyzed retrospectively. MRI was performed in all patients, and FDG-PET was performed in 17 patients. We compared the MR and FDG-PET findings of FCD according to the histologic findings that were classified into three grades.

RESULTS

Four cases were classified as Grade I, 4 cases as Grade II, and 11 cases as Grade III FCD. The lesions were detected on MRI in 9 (82%) of the 11 patients with Grade III FCD and in only 1 (13%) of the 8 patients with Grade I and II FCD. Cortical hypometabolism of the lesion was revealed on FDG-PET in 6 (86%) of the 7 patients with Grade I and II FCD and in 9 (90%) of the 10 patients with Grade III FCD. The extent of the cortical abnormality was larger on FDG-PET than on MRI in 11 (65%) of the 17 patients.

CONCLUSION

FDG-PET is more useful in delineating the cortical abnormality in patients with mild degrees of FCD. The extent of the lesion was larger or similar on FDG-PET compared with that of the MRI.

Cerebellar vasoreactivity in stroke patients with crossed cerebellar diaschisis assessed by acetazolamide and 99mTc-HMPAO SPECT

Crossed cerebellar diaschisis (CCD) tends to persist or even worsen after supratentorial infarction. Several studies have shown impairment of cerebral vasomotor responsiveness in the hemispheric area of diaschisis in patients with hemispheric infarction. This finding has led to the concern that the lack of CCD reversibility might be associated with chronic circulatory abnormalities. We therefore assessed the vasoreactivity in the cerebellar hemisphere in which diaschisis is manifested using acetazolamide (ACZ) and SPECT.

METHODS

Eight stroke patients with CCD (5 with unilateral hemispheric infarcts and 3 with unilateral intracerebral hemorrhage) had 99mTc-HMPAO SPECT scanning at rest and 20 min after intravenous injection of 1.0 g ACZ. The time interval after stroke ranged from 25 to 904 d. From the total counts obtained from each cerebellar hemisphere, the asymmetry index (AI) was calculated as (unaffected - affected cerebellar hemisphere)/unaffected cerebellar hemisphere x100.

RESULTS

After ACZ, the mean AI (8.7+/-6.6) was significantly decreased (P<0.05) compared with that at rest (17.7+/-5.8). Seven of the 8 patients showed decrease in the AI after ACZ. In 1 patient, the direction of the asymmetry was reversed after ACZ so that the AI was negative. The ACZ-induced change in the AI did not show a significant correlation with the time interval after stroke, whether calculated in absolute terms or as a percentage change.

CONCLUSION

This study shows that normal vascular supply is maintained in the CCD-affected cerebellar hemisphere over long periods of time after a stroke. Thus, the lack of CCD reversibility may not be attributed to a chronic circulatory insufficiency. The results lend support to the concept of functional deactivation and subsequent transneuronal degeneration as a likely explanation for CCD. It is unclear whether decreased AI after ACZ indicates a higher vascular response of the affected cerebellar hemisphere than that of the normal side.

Contralateral EEG slowing and amobarbital distribution in Wada test: an intracarotid SPECT study

PURPOSE

To relate the occurrence of contralateral electroencephalogram slowing (CES) to amobarbital distribution, we performed electroencephalogram (EEG) monitoring and intracarotid single photon emission computed tomography (SPECT) during an intracarotid amobarbital procedure (IAP).

METHODS

IAP was performed on 22 patients with temporal lobe epilepsy. CES was defined as the occurrence of significant EEG slowing on the contralateral hemisphere (>50% of the ipsilateral hemisphere slowing) after amobarbital injection. To map the distribution of the amobarbital, we injected a mixture of amobarbital and (99m)technetium-ethylcysteinate dimer (99mTc-ECD) into the internal carotid artery and performed a brain SPECT 2 h later. In the SPECT images, regions of interest were determined by ipsilateral and contralateral anterior cerebral artery territories (iACA, cACA), ipsilateral and contralateral middle cerebral artery territories (iMCA, cMCA), and ipsilateral and contralateral posterior cerebral artery territories (iPCA, cPCA), as well as ipsilateral and contralateral anterior and posterior mesial temporal regions (iAMT, cAMT, iPMT, cPMT). The perfusion of amobarbital was interpreted visually in each region.

RESULTS

Amobarbital was distributed in the iMCA in all the patients; in the iACA in 20 (90.9%) patients; in the iAMT in 14 (63.5%); and in the iPCA and iPMT in only two (9.1%). CES was observed in 13 (59.1%) patients. Cross-perfusion of amobarbital in limited areas of the cACA were observed in only four of 13 patients. Wada retention memory scores (WRMS) showed no significant difference between the CES- (n = 9) and CES+ (n = 13) groups.

CONCLUSIONS

Amobarbital rarely perfused the iPCA territory and the iPMT region and was rarely delivered to the contralateral hemisphere. The occurrence of CES was not related to the cross-perfusion of amobarbital. CES appears to be produced by a transient functional disconnection from the ipsilateral hemisphere.

Anticancer activity of hydrophobic peptides from soy proteins

An anticancer peptide from soy protein was purified and isolated. Defatted soy protein was hydrolyzed with thermoase and hydrophobic peptides were extracted with ethanol. The peptide extract was fractionated by XAD-2 hydrophobic, gel filtration chromatography, and different C18 HPLCs. Anticancer activity of each fraction was assayed by measuring in vitro cytotoxicity on P388D1, a mouse monocyte macrophage cell line. IC50 value of a peptide fraction from Sephadex G-25 chromatography was 0.16 mg/ml. This peptide fraction at 1 mg/ml significantly affected cell cycle progression by arresting P388D1 at G2/M phases. Finally purified peptide from analytical C18 HPLC was nonapeptide of which molecular weight was 1157 Da and the sequence was X-Met-Leu-Pro-Ser-Tye-Ser-Pro-Tyr.

Partial seizures manifesting as apnea only in an adult

PURPOSE

Although several cases of apneic seizures have been reported in neonates, epileptic seizures presenting as apnea only in adults are very rare. We present a case report of a 19-year-old man with viral encephalitis and frequent episodes of apneic seizures.

METHODS

Prolonged electroencephalograms (EEGs), respiratory monitorings, and imaging including ictal-interictal subtraction single photon emission computed tomography (SPECT) coregistered with magnetic resonance imaging (MRI) were performed.

RESULTS

Ictal EEGs recorded during apneic episodes showed repetitive sharp waves or rhythmic theta activity arising from the left or right independent bitemporal region. Ictal SPECT was performed during one episode of apnea that showed ictal EEG discharges arising from the left posterior temporal area. Ictal-interictal subtraction SPECT coregistered with MRI revealed that the seizures originated from the left, posterior, midlateral temporal cortex.

CONCLUSIONS

Previous studies with ictal EEG or brain stimulation suggest that apneic seizures might be mediated through the limbic and associated cortical systems. Our study reports on a very rare case of partial seizures with apnea only in an adult patient and is supported by ictal EEG and ictal-interictal subtraction SPECT coregistered with MRI.

Occurrence of hippocampal sclerosis: is one hemisphere or gender more vulnerable?

PURPOSE

We analyzed a large group of patients investigated for suspected seizures to test whether gender or side are important factors in the origins of hippocampal sclerosis (HS).

METHODS

We studied 996 consecutive patients (48% men, 52% women) by using standard hippocampal T2-relaxometry methods.

RESULTS

HS was associated with a highly abnormal T2 time (< or =113 ms). Categoric analysis showed that hippocampal T2 time was independent of gender and side. T2 time was bilaterally normal in 81% of men and in 79% of women; it was unilaterally abnormal in 15% of both men and women; and bilaterally abnormal in 4% of men and in 6% of women. Highly abnormal T2 relaxometry, suggesting HS, occurred with equal frequency in men and women and on the right and left sides. Quantitative analysis of hippocampal T2 times showed values not differing significantly between men and women or between the right and left hemispheres. There was no significant interaction between gender and side.

CONCLUSIONS

In patients with seizure disorders, hippocampal T2 relaxometry is not different in adult men and women and in the right and left hemispheres.

Hippocampal T(2) abnormalities correlate with antecedent events and help predict seizure intractability

INTRODUCTION

We performed hippocampal T(2) relaxometry as part of a routine magnetic resonance imaging (MRI) examination in 50 normal controls and 127 consecutive patients referred because of suspected seizures.

METHODS

On the basis of T(2) values in controls (100.2 +/- 4.2 ms) we defined normal as <110 ms (<mean + 2 SD), borderline as 110-113 ms (mean + 2 SD to mean + 3 SD) and abnormal as >113 ms (>mean + 3 SD).

RESULTS

After detailed investigation, 103 of these 127 patients had epilepsy and 24 did not. In the nonepilepsy group, none had abnormal hippocampal T(2) values. Twenty-seven of the 103 patients in the epilepsy group had abnormal values, 7 were borderline and 69 were normal. Only 5 patients with abnormal T(2) values did not have temporal lobe epilepsy: 1 had extratemporal lobe epilepsy, 1 had generalized epilepsy and 3 had unclassified epilepsy. Twenty-two of 27 (81%) patients with abnormal hippocampal T(2) values had intractable epilepsy [compared with 32 of 69 (46%) patients with normal values; p < 0.05, chi(2) test]. Two thirds of patients with abnormal values had a history of a major antecedent event (compared to only 7% of those with normal values, p < 0.05, chi(2) test).

CONCLUSION

Abnormal T(2) relaxometry is significantly associated with intractable epilepsy as well as with major antecedent events.

White-matter change in mesial temporal sclerosis: correlation of MRI with PET, pathology, and clinical features

PURPOSE

To assess the magnetic resonance imaging (MRI), positron emission tomography (PET), pathology, and clinical findings of patients with the MRI feature of white-matter change (WMC) in the anterior temporal lobe.

METHODS

Fifty-six patients with pathologically proven mesial temporal sclerosis were included in this study. MRI and 18F-2-deoxyglucose-(FDG) PET images were obtained before surgery in all patients. The patients were divided into two groups according to the presence of WMC on their MRI. WMC consists of an indistinct gray-white matter demarcation and an increased signal intensity of the anterior temporal lobe on T2-weighted images. The two groups were then compared in terms of MRI, PET, pathology, and clinical features.

RESULTS

The MRI feature of WMC was observed in 18 (32%) of the 56 patients. PET images of those patients revealed more severe hypometabolism of the ipsilateral temporal lobes (p< 0.05). In terms of histologic findings, larger numbers of heterotopic neurons were observed in the anterior temporal lobe white matter of these patients who also shared the following clinical features: earlier seizure onset, frequent history of febrile convulsions, and favorable surgical outcomes.

CONCLUSIONS

The MRI feature of WMC is an additive sign for correct seizure lateralization and may be related to a favorable surgical outcome in patients with temporal lobe epilepsy.

Diffuse and focal adenomyosis: MR imaging findings

Adenomyosis is a common gynecologic disorder that affects women during their menstrual life. Preoperative magnetic resonance (MR) images obtained in 45 patients with pathologically proved adenomyosis who underwent hysterectomy were retrospectively reviewed. Diffuse adenomyosis was seen in 30 cases (66.7%) and focal adenomyosis in 15 cases (33.3%). On T2-weighted MR images, diffuse adenomyosis usually manifested as diffuse thickening of the endometrial-myometrial junctional zone (7-37 mm; mean, 16 mm) with homogeneous low signal intensity. T2-weighted MR images were superior to contrast material-enhanced T1-weighted images in the evaluation of junctional zone thickening. High-signal-intensity foci were observed on T2-weighted images only in nine cases and on both T1- and T2-weighted images in three cases. Focal adenomyosis manifested on both T2-weighted and contrast-enhanced T1-weighted MR images as a localized, low-signal-intensity round or oval mass with a diameter of 2-7 cm (mean, 3.8 cm). All but one of the focal lesions had ill-defined margins. High-signal-intensity foci were noted in all cases of focal adenomyosis, either on T2-weighted images only (four cases) or on both T1- and T2-weighted images (11 cases). MR imaging is useful in diagnosing adenomyosis, differentiating adenomyosis from uterine myoma, and planning appropriate treatment.

Diffusion-weighted magnetic resonance imaging in probable Creutzfeldt-Jakob disease: a clinical-anatomic correlation

BACKGROUND

Creutzfeldt-Jakob disease (CJD) is a rare transmissible disease that typically causes a rapidly progressive dementia and leads to death in less than 1 year. Although a few anecdotal reports suggest that diffusion-weighted magnetic resonance imaging may help substantiate premortem diagnosis of CJD, detailed correlation between radiographic data and clinical, electrophysiologic, and metabolic parameters is not available.

METHODS

Signal abnormalities on diffusion-weighted images in 3 consecutive patients with probable CJD were correlated with psychometric features, electroencephalographic findings, and functional images with either positron emission tomography or single photon emission computed tomography.

RESULTS

Focality of abnormalities on diffusion-weighted image, not apparent on routine magnetic resonance images, correlated closely with clinical manifestations of CJD. The topographic distribution of signal abnormality on diffusion-weighted image corresponded with abnormal metabolism or perfusion on positron emission and single photon emission computed tomographic scans. In 2 cases, the laterality of diffusion abnormalities correlated with periodic sharp wave activity on electroencephalograms.

CONCLUSION

These findings extend previous observations that suggested a diagnostic and localizing utility of diffusion-weighted imaging in CJD.

The effect of continuous ambulatory peritoneal dialysis on change in serum leptin

OBJECTIVE

Elevated serum leptin can contribute to anorexia and poor nutrition in patients with chronic renal failure, because leptin is elevated in chronic renal failure patients with or without dialysis, especially in chronic ambulatory peritoneal dialysis (CAPD) patients. The aim of this study was to find whether leptin can be removed by peritoneal dialysis (PD) and to analyze factors that can affect serum leptin after start of CAPD by observing the change in serum leptin shortly after start of CAPD and its correlation with body mass index (BMI), with serum insulin, and with residual renal function.

DESIGN

Twenty patients who started CAPD during the observation period were studied. Serum leptin was measured by radioimmunoassay before start of CAPD, 3-5 days after start of CAPD, and 1 month and 3 months after start of CAPD. Simultaneously, body weight, serum insulin, and residual renal function were measured. To compensate for the circardian rhythm of leptin, removal of leptin was assessed by measuring dialysate leptin divided by average serum leptin before and after a peritoneal equilibration test (PET).

RESULTS

Leptin was eliminated by PD with a dialysate-to-serum ratio of 0.16+/-0.07, which was comparable to removal of beta2-microglobulin (0.14+/-0.06). The mean serum leptin concentrations did not decrease after 3-5 days of CAPD (8.4+/-13.1 ng/mL-->11.9+/-18.0 ng/mL) despite its removal by PD, and levels increased markedly to 189% of basal serum leptin 1 month after start of PD and to 260% of basal serum leptin 3 months after start of PD. Correlation coefficients (Spearman's rho) between change of serum leptin and change of BMI, of serum insulin, of glomerular filtration rate (average of urine creatinine clearance and urine urea clearance) were 0.267 (p > 0.05, n = 20), 0.441 (p > 0.05, n = 16), 0.706 (p > 0.05, n = 8) respectively.

CONCLUSION

Leptin is removed by peritoneal dialysis. Serum leptin did not decrease in 5 days after the start of PD despite its removal by PD, but increased markedly thereafter, within 3 months after start of PD. We could not find a significant correlation between the change in leptin and the change in BMI. Factors other than fat-mass gain can stimulate leptin increase shortly after start of PD.

Sesquiterpene esters from Celastrus orbiculatus and their structure-activity relationship on the modulation of multidrug resistance

Six new (1-6) and three known (7-9) sesquiterpene esters were isolated from the roots of Celastrus orbiculatus. The structures of the new compounds were elucidated as 1beta-acetoxy-6alpha-furoyloxy-9alpha-benzoyl oxydihydro-beta-agarofur an (1), 1beta-acetoxy-6alpha-benzoyloxy-9alpha-furoyloxydih ydro-beta-agarofur an (2), 1beta-acetoxy-6alpha, 9alpha-difuroyloxydihydro-beta-agarofuran (3), 1beta, 2beta-diacetoxy-6alpha-furoyloxy-9alpha-benzo yloxydihydro-beta-agarof uran (4), 1beta-acetoxy-2beta, 6alpha-difuroyloxy-9alpha-benzoyloxydihydro-beta -agarofuran (5), and 1beta-acetoxy-2beta,6alpha, 9alpha-tribenzoyloxydihydro-beta-agarofuran (6). Compounds 4, 5, and 7-9 were shown to be more active than verapamil in reversing vinblastine resistance in multidrug-resistant KB-V1 cells.

SPECT measurement of iodine-123-beta-CIT binding to dopamine and serotonin transporters in Parkinson's disease: correlation with symptom severity

Iodine-123-beta-CIT (2 beta-carbomethoxy-3 beta-(4-iodophenyl)tropane) binds with high affinity to dopamine (DA) and serotonin (5-HT) transporters. This study examined the correlation of single-photon emission computed tomographic (SPECT) measures of [123I]beta-CIT binding to DA and 5-HT transporters with symptom severity in Parkinson's disease (PD). Forty-six L-dopa-responsive PD patients (Hoehn-Yahr stage 1-3) had SPECT scans at 20-24 h after injection of [123I]beta-CIT. Specific to nondisplaceable uptake ratios (designated V"3) were calculated in the striatum and hypothalamic/midbrain region, where the binding of [123I]beta-CIT is associated primarily with DA and 5-HT transporters, respectively. Striatal V"3 was significantly correlated with Hoehn-Yahr stage and total, motor and activities of daily living scores of Unified Parkinson's Disease Rating Scale (UPDRS). There was a significant correlation between the sum of lateralizing motor UPDRS subscores (tremor, rigidity, bradykinesia) calculated for each side of limbs and V"3 values in the contralateral striatum. No significant correlation was found between striatal V"3 and UPDRS rating of mentation, behavior, and mood. Hypothalamic/midbrain V"3 was not significantly correlated with either Hoehn-Yahr stage or UPDRS scores including both motor and nonmotor measures. The significant correlation of SPECT measures of striatal [123I]beta-CIT binding with motor severity suggests that [123I]beta-CIT binding to striatal DA transporters can serve as an in vivo indicator of disease severity in PD, with potential utility in the serial monitoring of disease progression.

Effect of tracer metabolism on PET measurement of [11C]pyrilamine binding to histamine H1 receptors

The present study was carried out to investigate the time course of [11C]pyrilamine metabolism and the degree of entry of metabolites into the brain. PET studies were performed in seven healthy volunteers and arterial plasma concentrations of [11C]pyrilamine and its labeled metabolites were determined. After intravenous injection, [11C]pyrilamine metabolized gradually in the human body, with less than 10% of plasma activity being original radioligand at 60 min. Tracer metabolism markedly affected the input function and the calculated impulse response function of the brain. Rat experiments demonstrated that although metabolites of [11C]pyrilamine might enter the brain, they were not retained for prolonged periods of time. At 30-90 min after injection of [11C]pyrilamine, less than 1% of the radioactivity in the brain was originating from metabolites of [11C]pyrilamine. Based on the rat data, the contribution of 11C-labeled metabolites to total [11C]pyrilamine radioactivity in the human brain was estimated and found to be negligible. These results suggest that the metabolites of [11C]pyrilamine do not accumulate within the cerebral extravascular space and that there is minimal metabolism of [11C]pyrilamine by brain tissue itself. Therefore, [11C]pyrilamine metabolites can be neglected in kinetic analysis, using either a compartmental or a noncompartmental model, of the [11C]pyrilamine binding to histamine H1 receptors.

Pregnane glycoside multidrug-resistance modulators from Cynanchum wilfordii

The methanol-soluble extracts of the roots of Cynanchum wilfordii showed a significant multidrug-resistance-reversing activity, and four known pregnane glycosides were isolated by bioassay-directed fractionation and separation. Their structures were identified as gagaminin 3-O-beta-D-cymaropyranosyl-(1-->4)-beta-D-oleandropyranosyl- (1-->4)-b eta-D-cymaropyranosyl-(1-->4)-beta-D-cymaropyranoside (1), wilfoside K1N (2), wilfoside C1N (3), and cynauricuoside A (4). In particular, compound 1, at a concentration level of 1 microM, was found to completely reverse the multidrug-resistance of KB-V1 and MCF7/ADR cells to adriamycin, vinblastine, and colchicine.

Ginsenoside-Rs4, a new type of ginseng saponin concurrently induces apoptosis and selectively elevates protein levels of p53 and p21WAF1 in human hepatoma SK-HEP-1 cells

In this paper, we present evidence that ginsenoside-Rs4 (G-Rs4; an acetylated analogue of ginsenoside-Rg5), a new ginseng saponin isolated from Panax ginseng C. A. Meyer, elevates protein levels of p53 and p21WAF1, which are associated with the induction of apoptosis in SK-HEP-1 cells. Flow cytometric analyses showed that G-Rs4 initially arrested the cell cycle at the G1/S boundary, but consequently induced apoptosis as evidenced by generating an apoptotic peak. The induction of apoptosis was confirmed by the results of DNA fragmentation assays and alterations in cell morphology after treatment of the cells with G-Rs4. Immunoblot assays showed that G-Rs4 significantly elevated protein levels of p53 and p21WAF1, concurrently with the downregulation of both cyclins E- and A-dependent kinase activities and induction of apoptosis. We suggest that G-Rs4 induces apoptosis, the effect of which is closely related to the downregulation of both cyclins E- and A-dependent kinase activity as a consequence of selectively elevating protein levels of p53 and p21WAF1 in SK-HEP-1 cells.

Ginsenoside-Rs3, a new diol-type ginseng saponin, selectively elevates protein levels of p53 and p21WAF1 leading to induction of apoptosis in SK-HEP-1 cells

In this paper, we present evidence that Ginsenoside-Rs3 (G-Rs3), a new diol-type ginseng saponin isolated from the roots of Panax ginseng C.A. Meyer, efficiently arrests the cell cycle at the G1/S boundary at lower doses, 0.1-5 microM, but induces apoptosis at higher doses, 10-25 microM, the effects of which were associated with selectively elevating protein levels of p53 and p21WAF1 in SK-HEP-1 cells. The cell growth suppressive and apoptosis inducing effects were confirmed by MTT assays together with flow cytometric analyses, morphological changes and DNA fragmentation. Immunoblotting showed that G-Rs3 significantly elevated protein levels of p53 and p21WAF1 prior to inducing apoptosis, while it did not elevate those of cyclin E, cyclin A, p27Kip1, and PCNA. Immune complex kinase assays showed that G-Rs3 downregulated the activities of both cyclins E- and A-associated kinases. Collectively, we suggest that G-Rs3 selectively elevates protein levels of p53 and p21WAF1 and hence downregulates the activities of the cyclin-dependent kinases, resulting in cell cycle arrest at the G1/S boundary. We also propose that apoptosis induced by G-Rs3 is related to the elevations of p53 and p21WAF1 in the cells.

Investigation of angiotensin II/AT1 receptors with carbon-11-L-159,884: a selective AT1 antagonist

Antagonists of the angiotensin II AT1 receptor subtype have been recently introduced for treatment of arterial hypertension and for pharmacological studies of these receptors. The purpose of this work was to label such an antagonist with 11C and test the applicability of the radioligand for PET studies.

METHODS

The potent and selective nonpeptide AT1 antagonist L-159,884 was labeled with 11C and injected intravenously into six dogs. Renal accumulation and kinetics of the radioligand were imaged with PET at baseline and after receptor blockade with 1 mg/kg MK-996. Time-activity curves were derived from the renal cortex and were analyzed by the Gjedde-Patlak plot to obtain the influx rate constant of the radioligand.

RESULTS

There was selective radioligand binding in the kidneys, mainly located in the cortex. Within the time interval between 95 and 115 min postinjection, the radioactivity retained in the kidneys was 109 +/- 27 and 42 +/- 4 nCi/ml/mCi of the injected dose for the control and inhibition studies, respectively. The influx rate constant of the radioligand decreased from a baseline of 0.0298 +/- 0.0156 to a post-MK-996 value of 0.0098 +/- 0.0052.

CONCLUSION

These results demonstrate distinct binding of 11C-L-159,884 in the renal cortex with a specific binding component suitable for quantitative PET imaging of angiotensin II/AT1 receptors.

Gating provides improved accuracy for differentiating artifacts from true lesions in equivocal fixed defects on technetium 99m tetrofosmin perfusion SPECT

BACKGROUND

Because equivocal fixed perfusion defects on single photon emission computed tomography (SPECT) often cause a diagnostic dilemma in patients with suspected coronary artery disease (CAD), we used receiver-operating characteristic (ROC) curve analysis to evaluate the degree of increased accuracy provided by adding gated images for interpretation of such cases.

METHODS AND RESULTS

One hundred five (29%) of 365 consecutive patients undergoing technetium 99m tetrofosmin gated SPECT for evaluation of CAD demonstrated an equivocal fixed defect. Two independent observers graded the probability for true lesion with a 5-point system over 3 steps of interpretation: reviewing tomographic images alone (step 1), adding projection images (step 2), and adding gated cine images (step 3). Based on clinical criteria, 66 patients were categorized as disease negative and 25 as disease positive, while the final diagnosis was undetermined in 14 cases. Diagnostic performance was significantly higher at step 3 than at step 1 for both observers (p < 0.05 and < 0.0001) and at step 2 for observer B (p < 0.005). The maximum accuracy increased from 78.0% to 80.2% at step 2 to 84.6% to 86.8% at step 3. Moreover, the agreement of interpretation between the 2 observers was higher at step 3 (kappa = 0.53) than at step 1 (kappa = 0.29) or step 2 (kappa = 0.25).

CONCLUSION

In patients showing an equivocal fixed defect on 99mTc tetrofosmin SPECT, gated cine images provide improved differential accuracy and enhanced objectivity of interpretation by reducing interobserver variance.