Characterization of a cDNA encoding a novel type of RNA-binding protein in tobacco: its expression and nucleic acid-binding properties

A cDNA encoding an RNA-binding protein (ribonucleoprotein or RNP) was isolated from a tobacco (Nicotiana sylvestris) cDNA library. The predicted protein (termed RGP-2) is 259 amino acids in length and consists of an N-terminal sequence of 39 amino acids, a consensus sequence type RNA-binding domain of 82 amino acids, a glycine-rich domain of 83 amino acids and an acidic C-terminal domain of 46 amino acids. It is distinct from the RGP-1 proteins previously reported, which consist of an RNA-binding domain in the N-terminal half and a glycine-rich domain in the C-terminal half. Homology searches revealed that RGP-2 is a novel consensus sequence-type RNA-binding protein. Its RNA-binding domain is structurally related to those of some chloroplast RNPs, while the amino acid composition of its glycine-rich domain (rich in glycine and asparagine) is similar to those in animal heterogeneous nuclear RNPs (hnRNP) A1 and A2/B1. The RGP-2 gene seems to be a single-copy gene, and its transcripts accumulate mainly in cultured cells and roots. A nucleic acid-binding assay using RGP-2 protein synthesized in vitro confirmed that it is an RNA-binding protein. Based on its greater affinity for total tobacco RNA than for poly(G) and poly(U), RGP-2 is suggested to bind to specific RNA sequences, probably G/U-rich regions. Quantitative analysis of the nucleic acid-binding properties of RGP-2 and RGP-1b indicates that they bind differently to nucleic acids. A possible role for RGP-2 is discussed in relation to known functions of animal hnRNP proteins.

Latex agglutination test negative cryptococcal meningitis in an immuno-competent individual: a case report

We report a case with progressive mental deterioration and persistent low grade fever, who was diagnosed to have cryptococcal meningitis. This case is unique in that the cryptococcal latex agglutination antigen test was consecutively negative. The diagnosis was made by sequential CSF culture.

Impairment of renal medullary osmolyte accumulation in potassium-depleted rats

To determine the relationship between accumulation of osmolytes and maximal urinary concentration in potassium depletion, we tested the effects of experimental water diuresis or potassium depletion on osmolytes in the renal medulla of rats. Hyperosmotic stress was imposed by 4 days of water deprivation for the purpose of establishing the maximal concentrating ability or by the infusion of sodium for the purpose of loading the equal amounts of sodium to the renal medulla. In the diuresis group, water deprivation failed to increase betaine, sorbitol, and taurine contents to the same level as the untreated group, although sodium infusion increased betaine and sorbitol. In the potassium depletion group followed by water deprivation, urine osmolality (2,490 +/- 241 vs. 3,425 +/- 268 mosmol/kgH2O) and all osmolytes were significantly lower than in the untreated group. In response to hyperosmolality with sodium infusion, myo-inositol and glycerophosphorylcholine contents rose to the level of the untreated group. Medullary betaine (67.6 +/- 6.8 vs. 99.5 +/- 8.9), taurine (44.7 +/- 2.4 vs. 61.4 +/- 6.2) and sorbitol (35.6 +/- 4.4 vs. 57.0 +/- 8.4 mmol/kg protein) contents were reduced in potassium-depleted rats when the renal medulla was as hypertonic as in the untreated group. In conclusion, the processing of betaine, taurine, and sorbitol accumulation appeared to be impaired in potassium depletion.

Effects of recombinant superoxide dismutase on manganese superoxide dismutase gene expression in gerbil hippocampus after ischemia

BACKGROUND AND PURPOSE

We reported that recombinant human superoxide dismutase ameliorates delayed neuronal death in the postischemic gerbil hippocampus. Since postischemic induction of copper-zinc superoxide dismutase messenger RNA was abolished by this treatment, oxygen radicals generated on reperfusion may induce the expression of this gene. In the present study we examined whether oxygen radicals also induce the expression of manganese superoxide dismutase messenger RNA in the postischemic brain.

METHODS

We induced transient cerebral ischemia by occluding the bilateral common carotid arteries of gerbils. Recombinant human superoxide dismutase (8 x 10(5) U/kg) or apo-superoxide dismutase was administered intravenously 1 minute before a 5-minute occlusion of the carotid arteries. We analyzed both copper-zinc and manganese superoxide dismutase RNA by in situ hybridization histochemistry and by Northern and dot blot analyses using radioisotope-labeled oligonucleotide probes.

RESULTS

Hybridization with the manganese superoxide dismutase messenger RNA occurred at the limit of detection in normal CA1 neurons. We observed striking increases in the labeling of CA1 up to 24 hours after 5 minutes of ischemia. The hybridization occurred anew in glial cells of the CA1 layer during 3 to 7 days. Pretreatment with recombinant human superoxide dismutase had no effect on the postischemic induction of manganese superoxide dismutase messenger RNA, whereas the same treatment significantly attenuated (P < .01) the increase in copper-zinc superoxide dismutase messenger RNA.

CONCLUSIONS

Our results demonstrated temporal postischemic induction of manganese superoxide dismutase messenger RNA. The inducer may not be superoxide radicals but may be other chemical mediators such as cytokines.

In vivo osmoregulation of Na/myo-inositol cotransporter mRNA in rat kidney medulla

myo-Inositol, a major compatible osmolyte in renal medulla, is accumulated in kidney-derived epithelial cells cultured in hypertonic media via Na/myoinositol cotransporter (SMIT). The altered medium osmolality of Madin-Darby canine kidney cells leads to changes in the transcription of the SMIT gene and mRNA abundance. To investigate whether SMIT is regulated by tonicity in vivo, renal medullary myoinositol and SMIT mRNA was measured in rats in hydrated and dehydrated states. Rats were divided into two groups: (1) hydrated rats, free access to 3% sucrose water; (2) dehydrated rats, 3 days of water deprivation. Urine sodium, potassium, urea, and osmolality in dehydrated rats were significantly higher than in hydrated rats. Renal medullary sodium, urea, and myo-inositol in dehydrated rats were significantly higher than in hydrated rats. Northern analysis revealed that there was a message hybridized to SMIT cDNA in the cortex and outer and inner medulla of the kidney. Compared with hydrated rats, SMIT mRNA in dehydrated rats was 2.6-fold higher in the outer medulla and 2.5-fold higher in the inner medulla. These results indicate that there is osmoregulatory SMIT in the outer and inner medulla of the kidney and that myo-inositol accumulation in this region is probably due to the increased expression of the SMIT gene.

Organic osmolytes in rat renal inner medulla are modulated by vasopressin V1 and/or V2 antagonists

For the purpose of clarifying the role of vasopressin V1 and V2 receptors in osmolyte accumulation, we determined the effects on the inner medullary osmolyte content of the administration of orally active vasopressin V1 and/or V2 receptor antagonists OPC-21268 (i.e., 1-(1-[4-(3-acetylaminopropoxy)benzoyl]-4-piperidyl)- 3,4-dihydro-2(1H)-quinolinone) and OPC-31260 (i.e., 5-dimethylamino-1-[4-(2-methylbenzoylamino)benzoyl]-2,3,4,5-tet rah ydro-1H- benzazepine] under a condition of maximal urine concentration achieved by water deprivation for 4 days. Taurine content increased significantly with the use of the V2 antagonist, irrespective of the use of the V1 antagonist. Inner medullary betaine content decreased with the administration of the V1 antagonist, irrespective of the administration of V2 antagonist. The administration of either the V1 or V2 antagonist alone did not affect sorbitol content, aldose reductase activity, or aldose reductase mRNA abundance in renal inner medulla. However, the combined administration of the V1 and V2 antagonists decreased all of these significantly. Myo-inositol content was not affected by the administration of the V1 or V2 antagonists. Glycerophosphorylcholine content was decreased with the use of the V2 antagonist, irrespective of the use of the V1 antagonist, and this effect paralleled urine osmolality. In conclusion, the individual organic osmolytes responded differently to the antagonists of vasopressin V1 and/or V2 receptors. The mechanisms linked to vasopressin V1 and/or V2 receptors appeared to modulate the accumulation of some organic osmolytes in the inner medulla. Aldose reductase mRNA abundance and sorbitol accumulation in the inner medulla appeared to be mediated through either V1 or V2 receptors.(ABSTRACT TRUNCATED AT 250 WORDS)

Cerebral blood flow in subcortical global aphasia. Perisylvian cortical hypoperfusion as a crucial role

BACKGROUND AND PURPOSE

Global aphasia after subcortical stroke is very rare, and its pathophysiology remains unsolved. To clarify the mechanism underlying subcortical global aphasia, we investigated lesion sites and cerebral blood flow in patients with subcortical global aphasia and nonaphasic patients with subcortical stroke.

METHODS

We examined four patients with global aphasia and four nonaphasic patients. Language testing was performed more than 4 weeks after the onset. Measurement of cerebral blood flow was done between 35 and 75 days after stroke by using single-photon emission computed tomography (SPECT) with N-isopropyl-p[123I]iodoamphetamine as a tracer and three-dimensional surface display generated from SPECT.

RESULTS

All aphasic patients had subcortical lesions in the putamen, posterior internal capsule, temporal isthmus, and periventricular white matter in the left hemisphere. No cortical lesions were found on either magnetic resonance imaging or computed tomographic scanning. The nonaphasic patients had smaller periventricular white matter lesions and no temporal isthmus lesions. All aphasic patients showed cortical hypoperfusion mainly in the perisylvian areas, including Broca's and Wernicke's areas. In contrast, cortical cerebral blood flow of the nonaphasic patients was decreased in smaller areas and spared the perisylvian language areas.

CONCLUSIONS

These results suggest that cortical hypoperfusion in the perisylvian language areas, presumably due to undercutting of the white matter, is crucial for the development of subcortical global aphasia.

Risk factors for carotid atherosclerosis and platelet activation

Thromboxane A2 biosynthesis was studied in healthy subjects, in patients in whom the extent of carotid atherosclerosis was determined, and in patients receiving chronic aspirin treatment, to determine what factors activate platelets to develop carotid atherosclerosis. Urinary 11-dehydrothromboxane B2, a major metabolite of thromboxane A2, was measured by radioimmunoassay after purification by reverse-phase HPLC. The extent of carotid atherosclerosis was determined by real-time B-mode ultrasonography. The severity of carotid atherosclerosis in each subject was evaluated by plaque score, which was computed by summing the maximum thickness of plaque measured in millimeters. Urinary excretion of 11-dehydrothromboxane B2 in healthy subjects was higher (P < 0.01) in cigarette smokers (1063 +/- 244 ng/g creatinine) than in non-smokers (815 +/- 183 ng/g creatinine). Aspirin significantly suppressed 11-dehydrothromboxane B2 excretion (266 +/- 114 ng/g creatinine). In the 24 patients in whom the plaque score was measured, multivariate analysis indicated a significant positive correlation between urinary excretion of 11-dehydrothromboxane B2 and plaque score, age, smoking and hypercholesteremia. Our results indicate that risk factors such as age, hypercholesteremia, atherosclerosis and smoking activate platelets in vivo to develop carotid atherosclerosis.

[Beneficial effect of steroid pulse therapy on Wernicke-Korsakoff syndrome due to hyperemesis gravidarum]

A 25-year-old woman suffered from hyperemesis gravidarum when she was seven weeks pregnant. Since her vomiting continued, she received intravenous dextrose and electrolytes without thiamine in a hospital. One month later, she developed gait disturbance, followed by confusion and dysarthria. On admission to our department, she was confusional and had ataxic dysarthria. Spontaneous and gaze evoked nystagmus was present. Limb coordination was bilaterally ataxic. Based on her clinical course and symptoms, she was diagnosed as having Wernicke's encephalopathy. From the admission day, intravenous infusion of vitamin B1 (600 mg/day) was started. A few days later, her consciousness and limb ataxia began to improve. However, truncal ataxia and polyneuropathy became evident. Eight weeks after onset, she developed Korsakoff's psychosis such as anterograde and retrograde amnesia, disorientation and confabulation. We administered large amounts of corticosteroid (methylprednisolone 500 mg/day) in order to reduce brain edema or stabilize the impaired blood-brain barrier. Soon after, her psychosis began to improve gradually. She recovered remarkably from the psychosis, but she was left with persistent nystagmus, mild ataxic gait and polyneuropathy. The present case suggests that corticosteroid may have the beneficial effect on Wernicke-Korsakoff syndrome.

Effect of newly synthesized indole derivatives on multidrug resistance in human cancer cells

Twenty indole derivatives were investigated for their ability to reverse multidrug resistance (MDR), for their ability to compete with [3H]azidopine in binding to P-glycoprotein (P-gp) and for their hydrophobicity. Six derivatives almost completely reversed the resistance to vincristine (VCR) in multidrug-resistant KB-C2 cells, and other derivatives partially overcame the resistance. The ability of the derivatives to enhance vincristine cytotoxicity did not significantly correlate with the inhibition of [3H]azidopine binding to P-gp or with their hydrophobicity. However, all the derivatives that inhibited > 50% of the photolabeling completely reversed VCR resistance. The 2-pyridyl group with a basic nitrogen atom attached at position 3 of indole in an appropriate spatial orientation seems to be an important feature for the interaction of the indole derivatives with P-gp. One of the derivatives, 1, which has low cytotoxicity and hydrophobicity, completely reversed the resistance of KB-C2 cells to Adriamycin, actinomycin D and VCR. Our data indicate that MDR-reversing indole derivatives with low cytotoxicity and hydrophobicity exist. These characteristics will surely be profitable for clinical use.

[Inhibitory effect on anti-lipid IV antiserum binding activity of various synthetic oligosaccharides]

The inhibitory effects of various synthetic oligosaccharides (1-8) on anti-lipid IV antiserum binding activity were examined by ELISA (enzyme linked immunosorbent assay). Compound 8, containing an epitope GlcA-4Me beta 1-4Fuc of lipid IV, inhibited but precursors (1-5) of lipid IV did not inhibit the binding activity. In addition to the nonreducing end disaccharide derivative (6) having a methyl group at position 4 of glucuronic acid, its analogous compound (7) having no methyl groups was synthesized and their inhibition activities were compared. Moreover, the inhibitory effects of compounds (1-5) were examined using each antiserum.

Three-dimensional surface display of brain perfusion with 123I-IMP in Parkinson's disease

We reconstructed three-dimensional (3D) surface images from single-photon emission computed tomography (SPECT) data using N-isopropyl-p[123I]-iodoamphetamine (123I-IMP) in 27 patients with Parkinson's disease and 11 normal control subjects. The 3D reconstruction was performed using distance-shaded methods at threshold levels with an interval of 5% from 45-80%. Any area of decreased perfusion at each threshold level was visualised as a defect area by the algorithm. In nondemented patients with Parkinson's disease, perfusion defects were frequently found in the parietal cortex at a threshold value of 65%. In demented patients, perfusion defects were frequently seen at thresholds of 45-65%, and were more marked in the temporal and parietal cortex bilaterally. This suggests that dementia in Parkinson's disease is related to a reduction of perfusion in the temporoparietal cortex.

[Three-dimensional surface display with 123I-IMP brain perfusion imaging in patients with dementia]

We reconstructed three-dimensional (3D) surface images from single photon emission computed tomography (SPECT) data with N-isopropyl-p [123I]-iodo-amphetamine (123I-IMP) in 27 patients with Parkinson's disease, 16 patients with Alzheimer's disease, 9 patients with Binswanger's disease, and 11 elderly normal subjects. Three-D reconstruction was performed with Starcam 3000 XC/T using distance-shaded method at the threshold levels at intervals of 5% from 45% to 80%. In normal control subjects, no perfusion defects were found in any region at threshold values below 60%, although the frontal and temporal cortices occasionally showed perfusion defects at threshold levels from 60% to 80%. In patients with Parkinson's disease with dementia, perfusion defects were diffuse, particularly in the parietal and temporal cortices even at a threshold of 45%. Patients with Alzheimer's disease also showed diffuse perfusion defects, particularly in parietal and temporal cortices even at threshold levels as low as 45%. The primary visual cortex was less affected in these patients. The demented Parkinson's disease patients demonstrated perfusion defects similar to those of patients with Alzheimer's disease, although perfusion defects were more prominent in patients with Alzheimer's disease. In patients with Binswanger's disease, patchy perfusion defects were found most frequently in the frontal region. In addition, perfusion defects in the cerebellum and sensory motor cortex were more frequent in the Binswanger's disease patients than in patients with Alzheimer's or Parkinson's disease and normal subjects. The demented Parkinson's disease patients showed perfusion defects in the temporal and parietal cortices and demonstrated a perfusion pattern similar to that of patients with Alzheimer's disease.(ABSTRACT TRUNCATED AT 250 WORDS)

[A case of bronchial neurinoma treated with bronchofiberscopic electrosurgery and right S6 sleeve segmentectomy]

A 30-year-old woman was admitted for cough and fever over a period of two months. Her chest X-ray film showed atelectasis of the right middle and lower lobes. Bronchofiberscopic examination revealed complete obstruction of the truncus intermedius by polypoid tumor. Its punched biopsy specimen was diagnosed as the benign tumor. Bronchofiberscopic resection was performed by high frequency snare, however the tumor remained at the membranous portion of the truncus intermedius and the right B6 orifice. Therefore, right S6 sleeve segmentectomy was carried out after two weeks. The pathological diagnosis of the exturpated tumor was neurinoma. There were no complications and she is well without any evidence of recurrence after surgery. Neurinoma of the tracheobronchial tree is extremely rare and only 84 cases have been reported.

Trigeminal sensory neuropathy with abnormal taste following acute sinusitis

We report a case of isolated trigeminal sensory neuropathy associated with impairment of taste sensation following acute sinusitis. Sensory disturbance was distributed mainly in the ophthalmic division, and partly in the maxillary and mandibular divisions. No other cranial nerves were involved. An otological procedure resulted in complete recovery. The unique combination of trigeminal neuropathy and abnormal taste seemed to be caused by the infectious process involving the gasserian ganglion of the trigeminal nerve.

Structure and differential expression of two distinct genes encoding the chloroplast elongation factor Tu in tobacco

We have isolated two nuclear genes, tufA and tufB, encoding chloroplast EF-Tu from a tobacco (Nicotiana sylvestris) genomic library. The tufA gene encodes a polypeptide of 478 amino-acid residues, consisting of a putative transit peptide of 70 residues and a mature EF-TuA of 408 residues. The tufB gene codes for a precursor proteins of 485 residues, containing a transit peptide of 77 residues and a mature EF-TuB of 408 residues. No introns were found in either gene. The sequence similarity within the coding regions of the two genes is 84.3% for nucleotides and 89.7% for amino acids. Multiple 5' ends of transcripts were observed for both tuf genes. Northern analysis revealed that the EF-Tu mRNA accumulated at least 30-fold more in leaf than in root tissue. Ribonuclease protection assays using gene-specific probes showed that the level of tufB mRNA is three-fold higher than that of tufA mRNA in leaves but in roots the tufB mRNA levels is less than half that of tufA mRNA. The relative amount of tufB mRNA is 30-fold higher in leaves than in roots whereas tufA messages are only five-fold higher in leaves. These data suggest that expression of both tuf genes is differentially regulated according to tissue and plastid type.

The existence of eukaryotic ribonucleoprotein consensus sequence-type RNA-binding proteins in a prokaryote, Synechococcus 6301

A group of proteins containing a conserved ribonucleoprotein consensus sequence (RNP-CS)-type RNA-binding domain (CS-RBD) of approximately 80 amino acids is present in eukaryotic cells and binds specifically to a wide variety of RNA molecules. We have isolated 12 kDa single-stranded DNA binding proteins from the unicellular cyanobacterium Synechococcus 6301. The amino-terminal sequence was determined and two distinct genomic clones were isolated from a Synechococcus 6301 genomic library. Sequence analysis revealed that two closely related proteins contain a single CS-RBD of 82 amino acids and are named as 12RNP1 and 12RNP2. Both of the CS-RBDs share the highest amino acid identity with those of chloroplast ribonucleoproteins (40-51%). The 12RNP proteins were expressed in Escherichia coli bearing plasmids encoding glutathione S-transferase/12RNP fusion proteins and subjected to in vitro nucleic acid-binding assay. Both 12RNP1 and 12RNP2 bind to RNA homopolymers poly(U) and poly(G), indicating that they might be RNA-binding proteins. This is the first example of such proteins in prokaryotes. The 12RNP1 and 12RNP2 genes are transcribed as monocistronic mRNAs and the steady-state mRNA level of 12RNP1 is over 20-fold than that of 12RNP2. Due to the easiness of genetic manipulations the cyanobacterium will provide an excellent system to analyze the function of not only cyanobacterial but also plant RNA-binding proteins.

Structure and expression of a cDNA encoding an RNA helicase-like protein in tobacco

The human P68 protein is an ATP-dependent RNA helicase and thought to be involved in cell growth and division. We have isolated a Nicotiana sylvestris cDNA which encodes a p68-like protein. Northern blot analysis showed that the transcript from the gene is accumulated in N. sylvestris leaves, roots and flowers, but not in N. tabacum-cultured cells.

[Multimodal evoked potentials in patients with dementia]

The event-related potential (ERP), somatosensory evoked potential (SEP) and visual evoked potential (VEP) were studied in 15 patients with Alzheimer's disease (AD), 16 patients with Parkinson's disease with dementia (PD), 7 patients with Binswanger's disease (BD) and 15 normal controls. ERP was recorded during auditory discriminative tasks. SEP evoked by median nerve stimulation was recorded from the second cervical vertebra and contralateral primary somatosensory cortex with a midfrontal reference. VEP was recorded during pattern reversal stimulation. All three groups with dementia showed significant prolongation of the N200 and P300 latencies of ERP compared with the normal controls. In addition, patients with AD showed significant prolongation of the P200 latency. There was a significant correlation between the P300 latency of ERP and MMSE scores in AD patients. Patients with AD and PD showed significant prolongation of the interpeak latency between N13 and P40 (N13-P40) and N20-P40 of SEP compared with the normal controls. Patients with BD showed significant prolongation of the N13-N20, N13-N33, N13-P40 and N20-P40. These results suggest that there is impairment of the ascending somatosensory pathway in patients with dementia. Patients with PD showed significant prolongation of the P100 latency of VEP compared with normal controls. There was a significant correlation between the N200 latency of ERP and the P100 latency of VEP in PD patients. The VEP results suggest that dysfunction in the central visual system plays a role in abnormal pattern VEP in PD. In conclusion, the present results show that these three dementing diseases have different electrophysiological features, which may be related to the underlying pathogenic mechanisms. Additionally, the measurement of multimodal evoked potentials may be helpful in the differential diagnosis of patients with dementia.

[Establishment and characterization of a CA125-producing human ovarian clear cell carcinoma cell line]

A human ovarian cancer cell line designated "KK" was established from ascites of a patient with ovarian clear cell carcinoma. This cell line was grown for more than 2 years and over 140 passages in medium RPMI1640 containing 10% FCS. Doubling time of this cell line at passage 70 was approximately 4 days and saturation density was 1.1 x 10(5)/cm2. Plating efficiency was approximately 23%. Chromosome analysis revealed aneuploidy with a model number of 67. PAS-positive substances were present in the cytoplasm. CA125 and SLX were detected in both the original tumor and the cultured cells. This cell line is less sensitive to cisplatin than KF cells and IC50 was 0.95 microM.

Progesterone and its metabolites: the potent inhibitors of the transporting activity of P-glycoprotein in the adrenal gland

P-glycoprotein (P-gp) is a transmembrane glycoprotein responsible for the multidrug resistant (MDR) phenotype in various cancer cells. It has been shown that P-gp transports various kinds of anti-cancer agents as well as hydrophobic chemicals. Although P-gp is also expressed in normal human tissues, such as liver, kidney, and adrenal gland, its function and transporting substrates in these tissues are still unknown. In previous work, we demonstrated that some compounds in human plasma modulate the transporting activity of P-gp. We also found that P-gp is expressed at a high level in the bovine adrenal gland and that this tissue contains large amount of compounds which inhibit the transporting activity of P-gp. We purified such compounds from the adrenal gland by monitoring the ability to enhance the accumulation of [3H]vincristine in MDR cells. Two major compounds were purified and identified as progesterone and pregnenolone by nuclear magnetic resonance (NMR) analysis. Progesterone was the most potent and abundant compound that inhibited the transporting activity of P-gp among the compounds extracted from bovine adrenal gland with methanol. We also found that six authentic progesterone metabolites in the 5 beta-metabolic pathway but none in the 5 alpha-metabolic pathway were able to enhance the accumulation of [3H]vincristine in MDR cells and to inhibit [3H]azidopine photolabeling of P-gp in the adrenal gland. These results indicate that some progesterone metabolites can interact with P-gp and that stereoisomerism around carbon 5 of the progesterone metabolites is important for them to be recognized by P-gp.

Brain perfusion imaging in Parkinson's disease and Alzheimer's disease demonstrated by three-dimensional surface display with 123I-iodoamphetamine

We reconstructed three-dimensional (3D) surface images from data from single-photon emission computed tomography (SPECT) with N-isopropyl-p[123I]-iodoamphetamine (123I-IMP) in 29 patients with Parkinson's disease, 16 patients with Alzheimer's disease and 11 normal control subjects. In patients with nondementing Parkinson's disease, perfusion defects were frequently found in the parietal cortical region at a threshold value of 65%. In demented Parkinson's disease patients, perfusion defects were frequently noted at threshold of 45-65%, and were more marked in the bilateral temporal and parietal cortices. In Alzheimer's disease, perfusion defects were similar to those found in dementing Parkinson's disease. These results suggest that dementia in Parkinson's disease is related to the perfusion reduction of the temporoparietal cortex, and may support the view that Parkinson's disease and Alzheimer's disease overlap in some patients. A 3D display of an 123I-IMP brain tomogram may be useful for detecting cortical lesions in patients with dementia or cognitive impairment.