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The molecular tilt azimuth in domains of a condensed phase in monolayers of 1-monopalmytoyl-rac-glycerol at the air/water interface exhibits a regular star texture. Lateral-force microscopy has been used to investigate the friction behavior of a monolayer that has been transferred onto a silicon substrate. The condensed domains revealed strong friction anisotropies and asymmetries. The angular dependence of these properties correlates well with the tilt azimuth of the alkyl tails in the monolayer.

N-isopropyl-p-[125I]iodoamphetamine (125I-IMP) binding to crude synaptosomal membranes of rat brain was saturable and pharmacologically displacable. Scatchard analysis of binding data revealed an apparent dissociation constant, KDof 56.2±5.2 $mUM, and the estimated maximum number of binding sites, Bmaxof 7.5±1.1 nmoles mg-1protein; and competition studies demonstrated structure activity relationships among structural analogues of arylalkylamines. These findings suggest that the retention mechanism of IMP in the brain is probably associated with saturable binding of IMP to extreme high-density, relatively low-affinity binding sites rather than any of the well-known amine receptors.

123I-labelled 15-(p-iodophenyl)-3-(R,S)-methylpentadecanoic acid (BMIPP) myocardial single photon emission computed tomography (SPECT) was performed in 17 patients with hypertrophic cardiomyopathy, and was compared with 201Tl exercise stress myocardial perfusion SPECT images. Fourteen patients showed asymmetrical hypertrophy, and three demonstrated apical hypertrophy. SPECT was performed 20 min and 3 h after injection of 111 MBq 123I-BMIPP at rest. Exercise stress 201Tl SPECT was performed at 10 min and 3 h after injection and was compared with BMIPP imaging. In 13 patients BMIPP accumulation in the hypertrophied area in the 20 min image was lower than that of 3 h 201Tl uptake. Interestingly, six patients demonstrated 201Tl redistribution in the region where the uncoupling of BMIPP uptake at 20 min and 201Tl accumulation at 3 h after exercise was observed. These findings suggest that impaired fatty acid metabolism or utilization in hypertrophic myocardium and ischaemia or impaired coronary flow reserve may be one of the causes of the abnormality of fatty acid accumulation.

N-isopropyl-p-I-123-iodoamphetamine (123I-IMP) is extracted by the brain in proportion to regional blood flow. It is particularly useful in the clinical assessment of various pathological conditions related to altered cerebral flow. Moreover, it has been reported that 123I-IMP is avidly incorporated into melanin and melanotic melanoma. We evaluated 123I-IMP scintigraphy using either planar or single photon emission tomography (SPET) studies in 10 patients with malignant melanoma. The patients were classified into two groups according to the tumour site: Group A, six patients with primary or metastatic cutaneous malignant melanoma of the extremity with planar scintigraphy; Group B, four patients with primary malignant melanoma of other organs with planar scintigraphy and SPET. In Group A, tumour uptake was demonstrated in four of six patients; in Group B, three of four patients had tumour accumulation on SPET and planar scintigraphy. SPET revealed the exact tumour localization, even in the case of a tumour located in the lung. These results suggest that planar scintigraphy using 123I-IMP is useful in the detection of malignant melanoma. Furthermore, more clear tumour localization is possible with SPET, even in the case of a tumour located in the lung.

Triplet energy migration in poly[(9-phenanthrylmethyl methacrylate)-co-(methyl methacrylate)] films has been investigated by phosphorescence spectroscopy. Phosphorescence spectra from triplet trap sites were slightly shifted toward the low-energy side with a rise in temperature. The energy migration rates in these systems are complicated, since the trap sites have various energy levels depending on the amplitude of interaction energies. The kinetic analysis was made on the basis of Bässler's model in which the site energies have a Gaussian distribution. The fitting procedure well reproduced the phosphorescence decay data in the temperature range 15−100 K, indicating that the concentration of the supertrap increased steeply with the motion of the matrix polymer.

The rates of intramolecular triplet energy transfer from carbazole (Cz) to naphthalene (Np) chromophore for the bichromophoric compounds with a flexible alkyl spacer, Cz−(CH2)n−Np, n = 4−12, doped in poly(methyl methacrylate) matrixes were measured by phosphorescence spectroscopy and laser flash photolysis. The results were interpreted in terms of a model that allows a distribution of donor−acceptor distances for a given spacer length by using Dexter's equation. This model provided the transfer rate for all the compounds tested, and the comparative study with experimental results indicated that the “through-space” mechanism mainly governs the intramolecular triplet−triplet energy transfer in flexible spacer compounds. The temperature dependence of the rates of triplet energy transfer was also investigated.

In an effort to develop new, clinically useful 99Tcm-diaminodithiol (99Tcm-DADT) complexes for the evaluation of regional cerebral perfusion, basic diaminodithiols (DADT-TM, DADT-HM and DADT-MHM) and three diaminodithiol ligands functionalized with p-iodophenethyl (DADT-IPE), N-ethyl-p-fluorophenethyl amine (DADT-EFPE) or N-ethyl-p-iodophenethyl amine (DADT-EIPE), whose chemical structures are analogous to N-isopropyl-p-iodoamphetamine (IMP), were synthesized, labelled with 99Tcmand evaluated comparatively in experimental animals. In addition, the relationships between the chemical properties of the derivatives and their brain uptake and retention were investigated. The results were: (1) Isomeric configuration of 99Tcm-DADT complexes has an influence on uptake and retention in the rat brain. (2) In basic 99Tcm-DADT complexes, a correlation exists between initial brain uptake and lipophilicity, but in 99Tcm-DADT complexes containing a chemical structure similar to that of IMP, no correlation exists. (3) 99Tcm-DADT-IPE has relatively high uptake and long retention in the rat brain.

Highresolution threeheaded single photon emission computed tomography SPET equipped with fanbeam collimators was applied to myocardial perfusion imaging in infants aged from 1 to 11 months n5. A tabletop designed specifically for infants was fixed on the SPET couch to reduce the radius of camera rotation to 13.2 cm. Significant improvement in resolution was achieved with the fanbeam collimators compared to parallelhole highresolution collimators. With the administration of approximately 37 MBq 2644 MBq 201T1, 5 min acquisition time was possible for SPET imaging, which provided good image quality in all patients. Thus, a smaller administration dose is possible within a practical short acquisition time, Highresolution fanbeam SPET imaging can be a routine diagnostic method for heart disease in newborn babies and infants.

201Tl single photon emission computed tomography (SPECT) was evaluated in 170 patients suspected of having a malignant pulmonary lesion greater than 20 mm in diameter on the surgical specimen. Delayed SPECT (at 3 h after injection) visualized all of the 147 malignant pulmonary lesions and 16 of the 23 (69.6) benign pulmonary lesions, and generally exhibited the lesion more clearly than the early SPECT images (at 15 min after injection). There was no significant difference in delayed ratio (uptake ratio of the lesion to the normal lung on delayed scan) among the various histological groups except between the adenocarcinoma and large cell carcinoma groups (P< 0.05), and no difference was noted between the malignant and benign lesions. However, in retention index (degree of retention in the lesion) a significant difference was noted between the malignant and benign lesions (P< 0.01), although there was no significant difference in this index among malignant different histology groups. These results indicate that this method is useful for visualizing malignant pulmonary lesions greater than 20 mm in diameter to exclude the possibility of malignancy in the lesions when no abnormal 201TI accumulation is observed. When the lesion shows abnormal 201Tl accumulation, the retention index seems to help differentiate malignant from benign lesions.

The Intrahepatic distribution of radioactivity after the per-rectal administration of 201TI-chloride and/or 99Tcm-pertechnetate was investigated in 177 studies in 149 patients with no liver disease or diffuse liver disease and compared with that of 99Tcm-stannous (99Tcm-Sn) colloid scintigrams. The patients were classified into two groups: distribution of intrahepatic radioactivity of 201Tl and/or 99Tcm-pertechnetate scintigrams similar to (homogeneous) or different from (heterogeneous) that of 99Tcm-Sn-colloid scintigrams. The heterogeneous group was divided into three subgroups: increased radioactivity of the right lobe (right dominant pattern), increased radioactivity of the left lobe (left dominant pattern) and uneven distribution of radioactivity in both lobes (uneven pattern). Of the 80 patients in whom the studies were performed in the supine position at rest, 14 (17.5) showed a heterogeneous pattern (8 right dominant, 4 left dominant, 2 uneven) and 66 (82.5) a homogeneous pattern. In the 97 patients allowed free body movement, 6 (6.2) showed a heterogeneous (1 right dominant, 5 left dominant) and 91 (93.8) a homogeneous pattern. A significant difference in the incidence of heterogeneous distribution between the resting and free body movement groups was found (P<0.05). One patient with a left dominant pattern after free body movement with 201Tl showed a right dominant pattern at rest in the 99Tcm-pertechnetate study. It is concluded that a heterogeneous intrahepatic distribution of inferior mesenteric vein blood is sometimes observed and that the distribution of portal vein blood flow seems to be affected by the patient's positioning and free body movement.

Among a group of patients (n=15) with acute coronary syndrome, the results of using two new myocardial radiopharmaceuticals - 123l-labelled 15-(p-iodo-phenyl)-3,R,S-methylpentadecanoic acid (BMIPP) and 123l-meta-iodobenzyl guanidine (MIBG) - were compared with dual 201Tl/99Tcm-pyrophosphate (Tl-PYP) imaging using single photon emission tomography (SPET). Defect scores were evaluated on a segment-by-segment basis for a total of 270 segments. For the 201Tl, BMIPP, and early and delayed MIBG studies, the mean (± S.D.) sums of defect scores were 9 ± 8, 18 ± 9, 22 ± 12 and 29 ± 9, respectively, revealing significantly higher scores for BMIPP and MIBG than 201Tl (P0.005). This was the case irrespective of various functional conditions, such as successful recanalization, failure of coronary angioplasty or restenosis. The culprit coronary artery was best identified using BMIPP, while MIBG SPET showed the most extensive defects. Normal perfusion with decreased BMIPP and MIBG uptake was frequently observed and associated with hypokinesis. 123I-BMIPP and MIBG are more sensitive for the detection of damaged myocardium, and the difference between perfusion and metabolism seems to reflect myocardial stunning.

Abstract: A radioactive implant induced X-ray emission (RIXE) technique was examined for the in vivo determination of heavy elements. By the use of67Ga,99mTc,123I,123Xe and201Tl implant excitation sources, the excitation efficiency and X-ray attenuation were measured to reveal the potential pairs of source-heavy element of interest for in vivo elemental analysis by the RIXE technique. Detection limits for the RIXE in vivo analysis were evaluated according to Currie's criterion. Four pairs,99mTc–Pb,201Tl–I,133Xe–Cd and123I–Cd are potential.

Abstract: Carrier-free99mTcO4– eluated from clinical99Mo/99mTc generators was examined to determine its specific activity. The observed specific activity was found to be always lower than the calculated value based on the99Mo–99mTc–99Tc decay scheme data. These results could be explained in terms of existence of excess Tc loaded onto generator column.

The triplet energy migration and transfer in Langmuir−Blodgett films prepared by the copolymers of octadecyl methacrylate with 2-(9-carbazolyl)ethyl methacrylate and (4-bromo-1-naphthyl)methyl methacrylate were measured and simulated by the Monte Carlo method. At a high donor density (1.3 × 10^-6 mol/m²), the triplet energy transfer takes place by a dynamic process, i.e., a few steps of energy migration among carbazole (donor) chromophores, and followed by energy transfer to bromonaphthalene (acceptor). By solving the differential equations relevant to the energy migration and energy transfer on a two-dimensional square lattice of 31 × 31 = 961 lattice points, we successfully simulated the time evolution of the triplet energy quenching. The calculated quenching efficiencies were in agreement with the experimental values observed in the LB film of poly(octadecyl methacrylate) containing both the donor and acceptor moieties.

Triplet energy migration in poly[(9-phenanthrylmethyl methacrylate)-co-(methyl methacrylate)] films has been investigated by time-resolved phosphorescence spectroscopy in the temperature range 15−100 K. Phosphorescence spectra from triplet trap sites were slightly shifted toward the low-energy side with the elapse of time. The spectral shift was simulated by the Monte Carlo method. The simulation reproduced experimental data, which allowed estimation of the dispersity of the site energies. Due to homogeneous broadening, the distribution function became broader with the increase of temperature.

To investigate the utility of neuroreceptor imaging in ischaemic cerebrovascular disorders, dual-tracer autoradiography using 99Tcm-hexamethylpropyleneamine oxime (HMPAO) for the evaluation of cerebral blood flow and 125I-iomazenil for the evaluation of central-type benzodiazepine receptor density was performed in experimental brain ischaemia created by occlusion of the unilateral middle cerebral artery of the rat. In the acute phase of ischaemia, 125I-iomazenil accumulation showed less of a decrease than 99Tcm-HMPAO in the cerebral cortex of the lateral convexity and in the lateral segment of the caudate putamen in the lesioned cerebral hemisphere. In the sub-acute phase, both 125I-iomazenil and 99Tcm-HMPAO accumulation increased in the lesion compared with the acute phase. A large accumulation of 99Tcm-HMPAO and 125I-iomazenil in the lesion was considered to be due to luxury perfusion and penetration of 125I-iomazenil hydrophilic metabolites from the blood into the brain tissue through the altered blood-brain barrier. In the chronic phase, 125I-iomazenil accumulation showed a more marked decrease than 99Tcm-HMPAO in the lesion. Moreover, the ipsilateral thalamus, which is remote from the lesion, revealed decreased 125I-iomazenil accumulation despite normal 99Tcm-HMPAO accumulation. Since the central-type benzodiazepine receptors are principally located not on the glial cells but on the neurons, the receptor density may exhibit a change that parallels the neuron density. These results suggest that central-type benzodiazepine receptor imaging is useful for the evaluation of neuronal damage when used in conjunction with brain perfusion imaging in ischaemic cerebrovascular disorders, except in the sub-acute phase.

A clean-up method using a monoclonal antibody affinity column was developed for the analysis of ochratoxin A (OTA) in coffee products. Monoclonal antibody specific for OTA was covalently bound to Sepharose-4B and the resultant affinity column was used for the clean-up of sample extracts. OTA was quantitatively recovered from the affinity column. The subsequent high performance liquid chromatography (HPLC) of the eluted sample revealed no marked interference peaks when compared with those extracts obtained by conventional approaches. The HPLC peak coinciding with OTA was confirmed by derivatization into ethyl and n-propyl esters. Furthermore, the present affinity column could be regenerated at least 30 times without significant loss of the binding activity. The detection limit of OTA in the present affinity column-HPLC procedure was 0.5 μg/kg for coffee beans and instant coffee powder, and 0.025 μg/kg for a canned coffee drink. The recoveries of OTA from coffee products were more than 98%, with coefficient variations in the range of 1.11%-4.56%.

To estimate right ventricular overload in paediatric cardiac disease, 201T1 scintigraphy was used to quantify right ventricular uptake. Six methods for calculating the 201T1 right-to-left ventricular uptake ratio (TRL) were compared, based on the location of regions of interest (ROIs), use of total count or mean count density, and the ROI-based method or profile method. When the TRL was compared with the right-to-left ventricular peak systolic pressure ratio (RVP/LVP), the mean count density method using entire right and left ventricular ROIs seemed to be appropriate, considering its simplicity, reproducibility and regression line. The linear regression line was RVP/LVP=1.15×TRL-0.13 (n=15, P=-0.0001), and RVP(mm Hg)=162× TRL-33 (n = 15, P=0.0001). In four patients with pulmonary stenosis, the changes of TRL were in good agreement with the right ventricular pressure changes after percutaneous balloon valvuloplasty. Thus, evaluation of thallium scintigraphy using this quantitative method can be a simple and effective way to evaluate patients with right ventricular pressure overloading.

Single photon emission computed tomography (SPECT) brain scans with N-isopropyl-(iodine 123) p-iodoamphetamine (123I-IMP) were performed three times in interictal periods in a 35-year-old man with intractable frontal lobe epilepsy and normal X-ray CT findings. The first scan showed decreased 123I-IMP uptake in the right frontal lobe. This abnormal image was regarded as the primary focus of his epilepsy on the basis of its regional agreement with focal epileptic discharges on EEGs. In the second scan, he showed normal imaging, while the third scan showed the same abnormal image as before, in the right frontal lobe. The frequency of his clinical seizures was almost unchanged during the intervals between scans and further EEGs recorded soon after each scan showed almost no changes in the basic activities and frequency of the epileptic discharges. Such fluctuations in SPECT brain imaging suggest that the severity of functional inactivation underlying the focal hypoperfusion image as an epileptic focus may fluctuate considerably in the interictal state with no relation to the clinical features of epilepsy.

A 42-year-old female presented with typical glossopharyngeal neuralgia. Magnetic resonance imaging demonstrated an epidermoid tumour in the left cerebellopontine angle. Surgery showed that the tumour was compressing the glossopharyngeal nerve but no vessel was related to the nerve. The tumour was subtotally removed and after surgery the patient showed a complete relief of pain. This is a very rare case of glossopharyngeal neuralgia alone due to an epidermoid tumour.

SOFCs are expected to achieve high electrical conversion efficiency in the CHP systems with small generating power, but the improvement in durability performance is needed for commercialization. In order to improve durability, Toho gas is working on ways to prevent cathode from breaking away. In order to decrease abrasion, it is effective to rise the cathode’s firing temperature. However, the cell performance can decrease if the temperature is too high. This paper reports on the relationship between SOFC cell performance, adhesion strength, and calcination temperature in order to find the adequate firing temperature.

123I-metaiodobenzylguanidine (MIBG), a tracer for sympathetic neuron integrity and function, was applied to 155 patients with various types of cardiac disease. The methods for quantification of MIBG and washout were studied as well as normal ranges. Heart-to-mediastinum average count ratio (H/M) correlated well with total heart count divided by injected activity (r=0.60, P< 0.0001 and r=0.72, P< 0.0001 for early and delayed images, respectively). Although as a whole left ventricular ejection fraction (LVEF) positively correlated with H/M ratio, decreased H/M ratio could be associated with normal LVEF, which may indicate that the MIBG activity was an independent variable compared with cardiac contractility. High washout rate was seen in various cardiac diseases, such as dilated cardiomyopathy, hypertrophie cardiomyopathy, ischaemic heart disease, hypertension, hypothyroidism and arrhythmia. The increased washout seems to be nonspecific to disease type, but is a common feature of damaged or failing myocardium.

Heart uptake and clearance of 123I-15-(p-iodophenyl)-3(R,S)-methyl-pentadecanoic acid (BMIPP) by whole-body scintigraphy in relation to left ventricular ejection fraction (LVEF) was evaluated in 34 patients with ischaemic heart disease. At 45 and 210 min after injection, anterior whole-body images were obtained. In each patient, multigated blood pool scintigraphy was also performed, and LVEF was calculated. The percentage heart uptake of BMIPP did not have a significant correlation with LVEF (R= –0.299, NS). In contrast, there was a positive correlation between LVEF measured by multigated blood pool scintigraphy and BMIPP count density of the heart (R=0.467, P=0.005). Myocardial BMIPP washout rate also positively correlated with LVEF (R=0.472, P=0.005). In addition to these observations, there was a positive correlation between the BMIPP count density of the heart and myocardial BMIPP washout rate (R=0.0543, P=0.001). Thus, the BMIPP count density of the heart and myocardial BMIPP washout rate derived from BMIPP whole-body scintigraphy directly correlated with LVEF. However, the correlations between these parameters and LVEF were not strong enough to allow left ventricular dysfunction to be assessed precisely.

The radionuclide 203Pb decays completely by electron capture to stable 203Tl with a half-life of 52 h. The primary radiation from the decay is gamma-ray radiation 280 keV (80). 203Pb is produced easily from the natural metal thallium by the method described below. 203Pb-chloride is a promising imaging agent for tumour scanning because of the large retention value for tumour tissue and the small value for normal organs, but the large value for the kidney and bone is a shortcoming when considering it as an imaging agent. The retention value of 203Pb in tumour tissue is larger than that of 201Tl and smaller than that of 67Ga. The tumour/inflammatory lesion retention ratio for 203Pb is very large in comparison with those for 67Ga and 201Tl. 203Pb accumulates to a large extent in viable tumour tissue, and less in necrotic tumour tissue and in inflammatory lesion. Therefore, 203Pb-chloride is far better for visualization of viable tumour tissue than 67Ga and 201Tl if the large retention values for the kidney and bone were reduced.