Real-time motion force-feedback system with predictive-vision for improving motor accuracy

Many haptic guidance systems have been studied over the years; however, most of them have been limited to predefined guidance methods. Calculating guidance according to the operator's motion is important for efficient human motor adaptation and learning. In this study, we developed a system that haptically provides guidance trajectory by sequential weighting between the operator's trajectory and the ideal trajectory calculated from a predictive-vision system. We investigated whether motion completion with a predictive-vision system affects human motor accuracy and adaptation in time-constrained goal-directed reaching and ball-hitting tasks through subject experiments. The experiment was conducted with 12 healthy participants, and all participants performed ball-hitting tasks. Half of the participants get forceful guidance from the proposed system in the middle of the experiment. We found that the use of the proposed system improved the operator's motor performance. Furthermore, we observed a trend in which the improvement in motor performance using this system correlated with that after the washout of this system. These results suggest that the predictive-vision system effectively enhances motor accuracy to the target error in dynamic and time-constrained reaching and hitting tasks and may contribute to facilitating motor learning.

Jasmonic acid is not a biosynthetic intermediate to produce the pyrethrolone moiety in pyrethrin II

Pyrethrum (Tanacetumcinerariifolium) produces insecticidal compounds known as pyrethrins. Pyrethrins are esters; the acid moiety is either trans-chrysanthemic acid or pyrethric acid and the alcohol moiety of pyrethrins is either pyrethrolone, cinerolone, or jasmolone. It was generally accepted that cis-jasmone was biosynthetic intermediate to produce the alcohol moieties of pyrethrin, and the biosynthetic origin of the cis-jasmone was postulated to be jasmonic acid. However, there was no direct evidence to prove this hypothesis. In order to uncover the origin of pyrethrolone moiety in pyrethrin II, feeding experiments were performed employing deuterium- and ¹³C-labeled compounds as substrates, and the expected labeled compounds were analyzed using UPLC MS/MS system. It was found that the pyrethrolone moiety in pyrethrin II was derived from 12-oxo-phytodienoic acid (OPDA), iso-OPDA and cis-jasmone but not from methyl jasmonate and 3-oxo-2-(2′-[Z]-pentenyl)-cyclopentane-1-hexanoic acid. The results supported that the biosynthesis of the pyrethrolone moiety in pyrethrin II partially used part of the jasmonic acid biosynthetic pathway, but not whole.

Feeding experiment using uniformly 13C-labeled α-linolenic acid supports the involvement of the decarboxylation mechanism to produce cis-jasmone in Lasiodiplodia theobromae

In our previous report, it was found that Lasiodiplodia theobromae produced cis-jasmone via partially utilizing the biosynthetic pathway of JA. A feeding experiment using uniformly ¹³C-labeled α-linolenic acid, which was added to the culture media of the fungus, strongly supported that the fungus produced CJ via the decarboxylation step of the biosynthetic pathway.

Tetraploidy-associated centrosome overduplication in mouse early embryos

Recently, we observed that tetraploidization of certain types of human cancer cells resulted in upregulation of centrosome duplication cycles and chronic generation of the extra centrosome. Here, we investigated whether tetraploidy-linked upregulation of centrosome duplication also occurs in non-cancer cells using tetraploidized parthenogenetic mouse embryos. Cytokinesis blockage at early embryonic stage before de novo centriole biogenesis provided the unique opportunity in which tetraploidization can be induced without transient doubling of centrosome number. The extra numbers of the centrioles and the centrosomes were observed more frequently in tetraploidized embryos during the blastocyst stage than in their diploid counterparts, demonstrating the generality of the newly found tetraploidy-driven centrosome overduplication in mammalian non-cancer systems.

Uncoordinated centrosome cycle underlies the instability of non-diploid somatic cells in mammals

Mammalian somatic cells are more stable as diploids, but the mechanisms underlying this stability are unclear. Yaguchi et al. show that changes in centriole licensing compromise the control of centrosome number in haploid or tetraploid human cells, suggesting that the ploidy-dependent control of the centrosome cycle explains the instability of non-diploid karyotypes.

In animals, somatic cells are usually diploid and are unstable when haploid for unknown reasons. In this study, by comparing isogenic human cell lines with different ploidies, we found frequent centrosome loss specifically in the haploid state, which profoundly contributed to haploid instability through subsequent mitotic defects. We also found that the efficiency of centriole licensing and duplication changes proportionally to ploidy level, whereas that of DNA replication stays constant. This caused gradual loss or frequent overduplication of centrioles in haploid and tetraploid cells, respectively. Centriole licensing efficiency seemed to be modulated by astral microtubules, whose development scaled with ploidy level, and artificial enhancement of aster formation in haploid cells restored centriole licensing efficiency to diploid levels. The ploidy–centrosome link was observed in different mammalian cell types. We propose that incompatibility between the centrosome duplication and DNA replication cycles arising from different scaling properties of these bioprocesses upon ploidy changes underlies the instability of non-diploid somatic cells in mammals.

Characterization of micron-size hydrogen clusters using Mie scattering

Hydrogen clusters with diameters of a few micrometer range, composed of 10^8-10 hydrogen molecules, have been produced for the first time in an expansion of supercooled, high-pressure hydrogen gas into a vacuum through a conical nozzle connected to a cryogenic pulsed solenoid valve. The size distribution of the clusters has been evaluated by measuring the angular distribution of laser light scattered from the clusters. The data were analyzed based on the Mie scattering theory combined with the Tikhonov regularization method including the instrumental functions, the validity of which was assessed by performing a calibration study using a reference target consisting of standard micro-particles with two different sizes. The size distribution of the clusters was found discrete peaked at 0.33 ± 0.03, 0.65 ± 0.05, 0.81 ± 0.06, 1.40 ± 0.06 and 2.00 ± 0.13 µm in diameter. The highly reproducible and impurity-free nature of the micron-size hydrogen clusters can be a promising target for laser-driven multi-MeV proton sources with the currently available high power lasers.

Elucidation of the biosynthetic pathway of cis-jasmone in Lasiodiplodia theobromae

In plants, cis-jasmone (CJ) is synthesized from α-linolenic acid (LA) via two biosynthetic pathways using jasmonic acid (JA) and iso-12-oxo-phytodienoic acid (iso-OPDA) as key intermediates. However, there have been no reports documenting CJ production by microorganisms. In the present study, the production of fungal-derived CJ by Lasiodiplodia theobromae was observed for the first time, although this production was not observed for Botrytis cinerea, Verticillium longisporum, Fusarium oxysporum, Gibberella fujikuroi, and Cochliobolus heterostrophus. To investigate the biosynthetic pathway of CJ in L. theobromae, administration experiments using [18,18,18-²H₃, 17,17-²H₂]LA (LA-d5), [18,18,18-²H₃, 17,17-²H₂]12-oxo-phytodienoic acid (cis-OPDA-d5), [5′,5′,5′-²H₃, 4′,4′-²H₂, 3′-²H₁]OPC 8:0 (OPC8-d6), [5′,5′,5′-²H₃, 4′,4′-²H₂, 3′-²H₁]OPC 6:0 (OPC6-d6), [5′,5′,5′-²H₃, 4′,4′-²H₂, 3′-²H₁]OPC 4:0 (OPC4-d6), and [11,11-²H₂, 10,10-²H₂, 8,8-²H₂, 2,2-²H₂]methyl iso-12-oxo-phytodienoate (iso-MeOPDA-d8) were carried out, revealing that the fungus produced CJ through a single biosynthetic pathway via iso-OPDA. Interestingly, it was suggested that the previously predicted decarboxylation step of 3,7-didehydroJA to afford CJ might not be involved in CJ biosynthesis in L. theobromae.

Tumor Microenvironment-Sensitive Liposomes Penetrate Tumor Tissue via Attenuated Interaction of the Extracellular Matrix and Tumor Cells and Accompanying Actin Depolymerization

Delivery of anticancer drugs into tumor cores comprised of malignant cancer cells can result in potent therapeutic effects. However, conventional nanoparticle-based drug delivery systems used for cancer therapy often exhibit inefficient tumor-penetrating properties, thus, suggesting the need to improve the functional design of such systems. Herein, we focus on the interactions between cancer cells and the extracellular matrix (ECM) and demonstrate that liposomes modified with slightly acidic pH-sensitive peptide (SAPSp-lipo) can penetrate in vivo tumor tissue and in vitro spheroids comprised of cancer cells and ECM. We previously reported SAPSp-lipo, tumor microenvironment-sensitive liposomes, are effectively delivered to tumor tissue (Hama et al. J Control Release 2015, 206, 67-74). Compared with conventional liposomes, SAPSp-lipo could be delivered to deeper regions within both spheroids and tumor tissues. Furthermore, tumor penetration was found to be promoted at regions where actin depolymerization was induced by SAPSp-lipo and inhibited by the polymerization of actin. In addition, SAPSp-lipo attenuated the interaction between cancer cells and ECM, contributing to the penetration of SAPSp-lipo. These results suggest that SAPSp-lipo penetrates tumors via the interspace route and is accompanied by actin depolymerization. Taken together, SAPSp-lipo demonstrates potential as a novel tumor-penetrable drug carrier for induction of therapeutic effects against malignant cells that comprise tumor cores.

Effective cytoplasmic release of siRNA from liposomal carriers by controlling the electrostatic interaction of siRNA with a charge-invertible peptide, in response to cytoplasmic pH

Condensing siRNA with cationic polymers is a major strategy used in the development of siRNA carriers that can avoid degradation by nucleases and achieve effective delivery of siRNA into the cytoplasm. However, ineffective release of siRNA from such condensed forms into the cytoplasm is a limiting step for induction of RNAi effects, and can be attributed to tight condensation of siRNA with the cationic polymers, due to potent electrostatic interactions. Here, we report that siRNA condensed with a slightly acidic pH-sensitive peptide (SAPSP), whose total charge is inverted from positive to negative in response to cytoplasmic pH, is effectively released via electrostatic repulsion of siRNA with negatively charged SAPSP at cytoplasmic pH (7.4). The condensed complex of siRNA and positively-charged SAPSP at acidic pH (siRNA/SAPSP) was found to result in almost complete release of siRNA upon charge inversion of SAPSP at pH 7.4, with the resultant negatively-charged SAPSP having no undesirable interactions with endogenous mRNA. Moreover, liposomes encapsulating siRNA/SAPSP demonstrated knockdown efficiencies comparable to those of commercially available siRNA carriers. Taken together, SAPSP may be very useful as a siRNA condenser, as it facilitates effective cytoplasmic release of siRNA, and subsequent induction of specific RNAi effects.

Development of multi-frequency ESR system for high-pressure measurements up to 2.5 GPa

A new piston-cylinder pressure cell for electron spin resonance (ESR) has been developed. The pressure cell consists of a double-layer hybrid-type cylinder with internal components made of the ZrO2-based ceramics. It can generate a pressure of 2 GPa repeatedly and reaches a maximum pressure of around 2.5 GPa. A high-pressure ESR system using a cryogen-free superconducting magnet up 10T has also been developed for this hybrid-type pressure cell. The frequency region is from 50 GHz to 400 GHz. This is the first time a pressure above 2 GPa has been achieved in multi-frequency ESR system using a piston-cylinder pressure cell. We demonstrate its potential by showing the results of the high-pressure ESR of the S=1 system with the single ion anisotropy NiSnCl6·6H2O and the S=1/2 quantum spin system CsCuCl3. We performed ESR measurements of these systems above 2 GPa successfully.

Relationship between microviscosity and high-frequency viscosity of polymer gel electrolytes

The frequency-dependent viscosity and conductivity of polymer gel electrolytes are investigated in the megahertz region to clarify how polymer affects the ionic mobility. The electric conductivity shows no dispersion below 10 MHz, where slow dynamics of polymer are observed in shear relaxation spectra, which indicates that the ionic motion is uncorrelated with the slow dynamics of polymers that determines the steady state shear viscosity. On the other hand, the shear viscosity around 100 MHz is somewhat correlated with the direct-current (DC) molar conductivity, suggesting that the measurement of the high-frequency viscosity can be a probe of the so-called microviscosity associated with the mobility of an ion.

Charge Separation at the Molecular Monolayer Surface: Observation and Control of the Dynamics

Charge separation dynamics relevant to an electron transfer have been revealed by time- and angle-resolved two-photon photoemission spectroscopy for an n-alkanethiolate self-assembled monolayer (SAM) on a Au(111) surface fabricated by a chemical-wet process. The electron was photoexcited into an image potential state located at 3.7 eV above the Fermi level (EF), and it survived well for more than 100 ps on dodecanethiolate (C12)-SAM. The degree of electron separation is precisely controlled by selecting the length of the alkyl chain (C10-C18). We have also evaluated molecular conductivity at the specific electron energy of EF + 3.7 eV. The tunneling decay parameter, β, was fitted by β90 K = 0.097 Å(-1) and βRT = 0.13 Å(-1). These values were one order smaller than that at around EF by conventional contact probe methods.

RETARDED GROWTH OF EMBRYO1, a new basic helix-loop-helix protein, expresses in endosperm to control embryo growth

We have isolated two dominant mutants from screening approximately 50,000 RIKEN activation-tagging lines that have short inflorescence internodes. The activation T-DNAs were inserted near a putative basic helix-loop-helix (bHLH) gene and expression of this gene was increased in the mutant lines. Overexpression of this bHLH gene produced the original mutant phenotype, indicating it was responsible for the mutants. Specific expression was observed during seed development. The loss-of-function mutation of the RETARDED GROWTH OF EMBRYO1 (RGE1) gene caused small and shriveled seeds. The embryo of the loss-of-function mutant showed retarded growth after the heart stage although abnormal morphogenesis and pattern formation of the embryo and endosperm was not observed. We named this bHLH gene RGE1. RGE1 expression was determined in endosperm cells using the beta-glucuronidase reporter gene and reverse transcription-polymerase chain reaction. Microarray and real-time reverse transcription-polymerase chain reaction analysis showed specific down-regulation of putative GDSL motif lipase genes in the rge1-1 mutant, indicating possible involvement of these genes in seed morphology. These data suggest that RGE1 expression in the endosperm at the heart stage of embryo development plays an important role in controlling embryo growth.

External radiotherapy for decompression of cholangiocellular carcinoma with obstructive jaundice: report of a case

Percutaneous transhepatic catheter drainage (PTCD) is generally performed for the treatment of obstructive jaundice. However, in some cases it is difficult to perform insertion because of lack of dilatation of the intrahepatic bile duct. We report a patient who had been suffering from jaundice as a result of recurrent cholangiocarcinoma near the hilum and whose symptoms were relieved by external radiotherapy. We consider radiotherapy for cholangiocarcinoma effective palliative treatment for decompression of obstructive jaundice.

Effect of pH on skin permeation enhancement of acidic drugs by l-menthol-ethanol system

The effect of pH on the skin permeation enhancement of three acidic drugs by the l-menthol-ethanol system was investigated. The total flux of acidic drugs from the system remarkably varied over the pH range 3.0-8.0, and the permeation enhancement factor depended on the system pH and drug. A skin permeation model, which consists of two permeant (unionized and ionized) species, two system (oily and aqueous) phases, and two permeation (lipid and pore) pathways, was developed. The assumptions were made that only the unionized species can distribute to the oily phase and transport via the lipid pathway. The model explained the relationship between the concentration of drug in the aqueous phase and system pH. The skin permeability data were also described by the model and permeability coefficients corresponding to the physicochemical properties of permeant were calculated for the lipid and pore pathways. The model simulation showed that the permeation of acidic drugs occurred from the aqueous phase and the oily phase acted as a reservoir. Whether the total flux increased with increase of pH was dependent on the lipophilicity of drug. These results suggest that the pH of l-menthol-ethanol system should be given attention to elicit the maximum permeation enhancement.

Reduced sarco/endoplasmic reticulum Ca(2+) uptake activity can account for the reduced response to NO, but not sodium nitroprusside, in hypercholesterolemic rabbit aorta

BACKGROUND

Hypercholesterolemia (HC) impairs acetylcholine-induced relaxation but has little effect on that caused by the NO donor sodium nitroprusside (SNP), suggesting that acetylcholine releases less NO from the endothelium in HC. The relaxation to authentic NO gas, however, is also impaired in HC aortic smooth muscle, indicating an abnormal smooth muscle response. NO relaxes arteries by both cGMP-dependent and -independent mechanisms, and the response involves calcium (Ca(2+)) store refilling via the sarco/endoplasmic reticulum calcium ATPase (SERCA). We studied the involvement of cGMP and SERCA in the smooth muscle response to NO and SNP in HC rabbit aorta.

METHODS AND RESULTS

A selective guanylyl cyclase inhibitor, 1H-[1,2,4]-oxadiazole-[4,3-a]quinoxalin-1-one, eliminated SNP-induced relaxation but only partially blocked NO-induced relaxation in both normal and HC aorta. The residual relaxation to NO was still less in HC and, in both normal and HC aorta, was abolished by concomitant administration of the SERCA inhibitor cyclopiazonic acid (CPA). In contrast, CPA did not affect SNP-induced relaxation in either normal or HC aorta. SERCA activity measured by (45)Ca(2+) uptake was markedly decreased in HC, although SERCA2 protein expression did not change significantly.

CONCLUSIONS

These data suggest that NO-induced relaxation but not that to SNP is partially mediated by cGMP-independent Ca(2+) uptake into sarco/endoplasmic reticulum and that reduced sarco/endoplasmic reticulum Ca(2+) pump function can account for the impaired response to NO in HC.

Technetium-99m MIBI single photon emission computed tomography as an indicator of prognosis for patients with lung cancer-preliminaly report

PURPOSE

We performed technetium-99m hexakis-2-methoxyisobutylisonitrile (Tc-99m MIBI) single photon emission computed tomography (SPECT) in 23 patients with primary lung cancer between July 1993 and March 1996. We evaluated the relationships among the uptake ratio, retention index and the prognosis after radiation therapy and/or chemotherapy.

MATERIALS AND METHODS

Tc-99m MIBI SPECT was performed at 30 minutes and at 3 hours after intravenous injection of 600 MBq of Tc-99m MIBI with three gamma camera detectors (GCA-9300A/HG) on transverse SPECT images. Regions of interest were set in the area of abnormal uptake of Tc-99m MIBI and in the contralateral normal lung. The ratio of uptake in the lesion to that in the contralateral normal lung was obtained on early images (early ratio; ER) as well as delayed images (delayed ratio: DR). The retention index (RI) was calculated as follows: RI = (DR - ER)/ER x 100. The ratio was compared with survival time and prognostic factors.

RESULTS

There was no correlation between ER and DR. The patients with high RI survived longer than those with low RI (median survival, 19.4 months vs. 9.4 months; p = 0.0104 by the Mantel-Cox test).

CONCLUSION

These results suggest that RI is the most useful among Tc-99m MIBI indices of primary lung cancer in predicting prognosis.

[Clinical symptoms and characteristic MR spectroscopic findings in Pelizaeus-Merzbacher disease]

Clinical symptoms and MR spectroscopic findings were studied on 4 cases of Pelizaeus-Merzbacher disease including 1 autopsy case. Common symptoms were severe mental retardation and spastic tetraplegia. These cases had nystagmus, and one had involuntary athetotic movement. Genetical diagnosis revealed in 2 cases, duplication of proteolipid protein (PLP) and deletion in 1, whereas one case had no abnormality of PLP gene. MRI indicated the reversal of signal intensities on T1- and T2-weighed images, a characteristic finding of PMD MR spectroscopy demonstrated a pattern of NAA in 3 cases. This was specific to PMD because other white matter diseases show a decrease in NAA. In conclusion, MRS was useful to differentiate PMD from other white matter diseases.

Development of a chronic skin defect model and a study of cytokine secretion using the model

In this study, we established a delayed healing chronic type wound model in order to investigate the etiology of chronic wound healing, including wound contraction. Establishment of the model was important for clarification of the mechanism(s) of chronic wound healing and wound contraction and for use in evaluating therapeutic efficacy. A pedicled skin flap was raised beneath the panniculus carnosus membrane on the backs of mice, and after the loose connective tissue at the base of the flap was completely removed surgically, the flap was replaced and sutured. Seven days after surgery, a full-thickness defect measuring 1.5 x 1.5 cm was made in the center of the skin flap. At that time, a defect of the same size, including the panniculus carnosus membrane, was made in another group of mice as controls, and changes with time in wound area were compared between the two groups. The exudate retained on the wound surface was collected, and various cytokines contained in the exudate were measured. In the control group, the wound rapidly contracted and almost completely epithelialized and closed 21 days after surgery. On the other hand, the wound area was significantly larger in the delayed model than in the control animals during the observation period, revealing a delay in wound contraction. Transforming growth factor-beta, interleukin-1beta, and tumor necrosis factor-alpha in the exudates from the wound of the model were significantly higher than in those of the control group, whereas interleukin-6 was low in the model. From these results, it was concluded that this model could be a useful experimental system for studies on wound contraction as well as clarifying the mechanism of so called chronic type wounds.

Esophageal varices before and after endoscopic variceal ligation: evaluation using helical CT

The purpose of this study was to demonstrate the utility of helical CT in assessing the therapeutic effects of endoscopic variceal ligation (EVL). Twenty-four patients with esophageal varices were examined. Helical scanning was initiated 60 s after intravenous injection (Iopamidol 300 mgI/ml, total 120 ml, 3 ml/s) was started. Esophageal varices were clearly depicted as high-density areas. Multiplanar reformation and 3D images demonstrated collateral circulation three-dimensionally. After EVL, mucosal high-density areas had diminished markedly, but collateral veins around the esophagus, and gastro- and/or spleno-renal shunts, were unchanged in all patients. Of 21 patients with collateral circulation, esophageal varices recurred endoscopically in 6 patients within 12 months. In 3 patients without collateral circulation, esophageal varices did not recur within 12 months. From these findings, we conclude that helical CT is a useful method for assessing the therapeutic effects of EVL.

[Collection conditions of ECG-gated myocardial SPECT]

In ECG-gated myocardial SPECT, we evaluated the effects of data acquisition and imaging conditions on the parameters of left ventricular cardiac function by a phantom experiments and in patients (n = 50) and normal controls (n = 15). Data acquisition was performed under the following conditions: (1) matrix size, 64 x 64 or 128 x 128; R-R interval, 8 or 6 frames; (3) presence or absence of attenuation and scatter corrections; and (4) changes in the accumulation rate of the radioactive tracer (information content) in the myocardium. When the matrix size was 64 x 64 and an R-R interval was divided into 8 frames, end-diastolic volume (EDV), end-systolic volume (ESV), and ejection fraction (EF) were 98.30 +/- 13.74 ml, 44.20 +/- 7.45 ml, and 54.91 +/- 2.84%, respectively, for normal controls. These values were slightly lower than those under other conditions. When attenuation and scatter corrections were not performed, the values of the above parameters were even lower. In patients with high accumulation of the radioactive tracer in the liver affecting the myocardial area, the cardiac function parameters were markedly decreased. In phantom experiments in which a decreased accumulation of the radioactive tracer was assumed, the left ventricular volume increased.

[A case of a traumatic anterior cerebral artery aneurysm following the penetration of the skull base by an iron rod]

A 61-year-old male fell from a position 1 m high when building a house. An iron rod, which protruded upward from a solid base in cement, penetrated this patient's neck 15 cm to the head and was successfully extracted by himself. On admission, he complained of headache and vomiting. General examination disclosed nasal bleeding, intraoral bleeding, and L figured skin laceration in the left side of his neck at the level of the thyroid cartilage. Mild disorientation (JCS2) was noted. Otolaryngological examination disclosed hyperemia on the left side of the vocal cord as well as at the dome of the superior pharynx. Plain skull film disclosed pneumocephalus and that a piece of bone fragment of the planum sphenoidale had penetrated the brain. CT demonstrated air in the subarachnoid space, ventricular hemorrhage, intracerebral hematoma in the right frontal lobe, and subarachnoid hemorrhage in the anterior interhemispheric fissure. CAG detected neither cerebral vascular abnormalities nor cerebral aneurysm. While staying in our department, he developed mild fever and CSF rhinorrhea. The diagnosis of bacterial meningitis was made from the CSF finding and was well controlled with conservative therapy. CSF rhinorrhea stopped spontaneously with conservative treatment. Sagittal MRI continuously demonstrated contusional hematoma in the base of the right frontal lobe just above the fractured planum sphenoidale and genu of the corpus callosum following the course of the intracranially invading iron rod. The right CAG on Day 10 demonstrated vasospasm on the A1 and a 1 cm sized saccular cerebral aneurysm at the proximal right fronto-polar artery. CAG on Day 17 again showed the persistent presence of the aneurysm. For the purpose of preventing delayed rupture of the aneurysm, radical surgical treatment was planned. Microsurgical dissection disclosed that the aneurysm was located just behind the elevated fracture of the planum sphenoidale. Severe arachnoid adhesion was noted around the aneurysm. The aneurysm was successfully clipped with preservation of the parent artery without inducing new neurological deficits. From the general, otolaryngological, neuroradiological, and operative findings, this aneurysm was diagnosed as a traumatic cerebral artery aneurysm following the penetration of the skull base by the iron rod. The CAG performed at 8 months postoperatively demonstrated the patency of the parent artery and that there was no recurrence of the aneurysm. An unusual case of a traumatic cerebral artery aneurysm following the penetration of the skull base by an iron rod was thus reported.

[Quantitative assessment of 201Tl-SPECT in tumors of bone and soft tissue]

201Tl-SPECT was performed to diagnose the malignancy of bone and soft tissue tumors by visual and quantitative assessment in 48 patients (17 malignant lesions and 31 benign lesions). SPECT images were obtained in the early phase (15 min after injection) and the delayed phase (240 min). By visual assessment a tumor was considered malignant if high accumulation was found in the tumor in the early phase and the accumulation was confirmed in the delayed phase. Tumors which did not meet these criteria were considered benign. For quantitative assessment, the ROI (region of interest) accumulation ratios of the tumor to the contralateral normal tissue in the early phase (ER) and in the delayed phase (DR), the ROI accumulation ratio of the delayed phase to the early phase of the tumor (Td/Te), and the ROI accumulation ratio of the delayed phase to the early phase of the contralateral normal tissue (Nd/Ne) were obtained. Sixteen patients with malignant tumors each had a high accumulation each but 12 of 31 benign lesions had no high accumulation on visual assessment. Furthermore, the accuracy was 85.4%, sensitivity 94.1%, and specificity 80.6%. Quantitative assessment was performed for 36 cases of high accumulation. The ER of malignant and benign lesions was 5.51 +/- 3.73 and 2.75 +/- 2.17, respectively, and the ER of malignant lesions was significantly higher than that of benign lesions. The DR did not demonstrate a significant difference. If the tumor having an ER greater than 3.9 was assumed to be malignant, the accuracy for differentiating malignant lesions from benign lesions was 85.4%. The Td/Te of benign lesions (0.97 +/- 0.28) was higher than that of malignant lesions (0.77 +/- 0.09). The Nd/Ne of normal tissue which contained muscles in both lesions were higher than 1.4. In conclusion, 201Tl-SPECT was very useful for the differential diagnosis of benign or malignant bone and soft tissue tumors. The ER was important for quantitative assessment, but a delayed image was necessary for visual assessment.

FGF-2 induces surfactant protein gene expression in foetal rat lung epithelial cells through a MAPK-independent pathway

Fibroblast growth factors (FGFs) play important roles in diverse aspects of animal development including mammalian lung epithelial cell proliferation, differentiation, and branching morphogenesis. We developed an in vitro lung epithelial cell culture system to study functions and mechanisms of FGFs in regulating growth and differentiation of primary foetal rat lung epithelial cells. In comparison with other growth factors such as IGF-I, EGF, and HGF, FGFs were the most potent mitogens in stimulating lung epithelial cell proliferation. In the presence of FGF-1, 2, or 7, the primary lung epithelial cells could be propagated for generations and grown for more than two mo in vitro. Among the three FGFs tested, FGF-7 showed the strongest stimulation in cell growth. FGF-2, on the other hand, is the most effective inducer of lung epithelial cell-specific surfactant protein gene expression (SP-A, -B, and -C). FGF-2 upregulated SP-C expression in a dose-dependent manner. More interestingly, the induction of surfactant protein gene expression by FGF-2 appeared to be independent of MAPK pathway, since the SP-C expression was not inhibited but rather augmented by MEK1 inhibitor which inhibited MAPK activation and cell proliferation. Similar effects were observed for the expressions of surfactant protein genes SP-A and SP-B. In contrast to MAPK, FGF-2-induced SP-C expression was partially inhibited by PI 3-kinase inhibitor wortmannin. These data suggest dynamic roles and complex signalling mechanisms of FGFs in regulating lung epithelial cell proliferation and differentiation. While a MAPK-dependent pathway is essential for all three FGFs to stimulate cell proliferation, a MAPK-independent pathway may be responsible for the FGF-2-induced surfactant protein gene expression. PI 3-kinase may play an important role in mediating FGF-2-induced lung epithelial cell differentiation during development.

Three-dimensional computed tomographic angiography of pulmonary vessels

OBJECTIVE

To assess the image quality of multiple threshold display (MTD) as a new technique for generating three-dimensional (3D) pulmonary computed tomographic (CT) angiographic images.

METHODS

We used MTD, a type of shaded surface display (SSD) offering the selection of multiple thresholds and transparencies, to reconstruct 3D-CT angiograms from enhanced helical CT data sets in 33 patients with lung disease. In MTD, eight thresholds of CT values are selected, and transparency is assigned to each. The selected voxels, ranging from -600 to 1,000 Hounsfield Units, were divided into eight classes, and transparency ranging from 0 to 100% was assigned to each. The CT scanner employed was a Toshiba Xvigor. MTD and SSD images were generated by using an Xtension with a Sun SPARC station 20, and they were compared by two radiologists.

RESULTS

The image quality of MTD images was superior to that of SSD images (p < 0.01), because the MTD images demonstrated clearly both the major and small vessels.

CONCLUSION

MTD is a useful technique for 3D pulmonary CT angiography.

Angiosarcoma of the tongue: report of a case with immunohistochemical findings

A case report of angiosarcoma of the tongue is presented. The specimen revealed single and clustered large, pleomorphic, and spindle-shaped cells with a markedly hemorrhagic background. Tumor cells showed expression of thrombomodulin and E-selectin, but no expression of Factor VIII-related antigen, Ulex europaeus agglutinin-1, vascular endothelial growth factor, and CD34. In the current study, immunohistochemical results using antibodies against thrombomodulin and E-selection supported the diagnosis of angiosarcoma.

[Evaluation of 99mTc-MAG3 (mercaptoacetyltriglycine) renography for pediatric patients]

It is difficult to evaluate renal function with 99mTc-MAG3 renography in both adult and pediatric patients. We examined 109 pediatric patients with various renal diseases using 99mTc-MAG3 renography. Tenal diseases were classified as follows: 9 vesicoureteral reflux, 4 ureteropelvic junctional stenosis, 3 double pelvis, 23 hydronephrosis, 4 glomerulonephritis, 4 nephrotic syndrome, 24 hemolytic uremic syndrome, 10 others; and 24 patients without abnormal findings on other examinations. After hydration and sedation, 100-200 MBq of 99mTe-MAG3 was injected intravenously. All patients were placed in the supine position, and dynamic data acquisition at 12 sec/frame x 100 frames was performed from the back. The renograms were prepared with the ROIs (regions of interest) set to include the entire kidney. Tmax and T1/2 of renograms were measured for 26 kidneys with no abnormal findings. The correlations between Tmax or T1/2 and age (days after birth) were determined by a linear or logarithmic function. The logarithmic function (Y = 7.49 - 0.56 logeX, r2 = 0.134) yielded a higher correlation than did the linear function (Y = 5.16 - 0.00194X, r2 = 0.089) between Tmax and age. For T1/2 and age (days after birth), the linear function (Y = 8.07 - 0.00451X, r2 = 0.222) yielded a higher correlation than the logarithmic function (Y = 11.9 - 0.986 logeX, r2 = 0.192). Our findings suggest that prolonged Tmax is normalized more rapidly than T1/2 after birth in infants. A delayed excretion phase is not suggestive of renal dysfunction, but is characteristic of renograms in pediatric patients. Abnormality was detected in all patients with hydronephrosis using 99mTc-MAG3 renography. On the other hand, a quantitative study was required because renography detected no abnormality for some of patients with disorders of renal parenchyma.

Assessment of proliferating cell nuclear antigen immunostaining in parotid tumors

We evaluated the prognostic value of immunostaining proliferating cell nuclear antigen (PCNA) by using a monoclonal antibody (PC10) in patients with parotid tumors. Twenty-seven cases were studied. Immunohistochemical studies were carried out on paraffin-embedded tissues from the patients, and the PCNA index was calculated as the percentage of positively staining tumor cells. The PCNA index ranged from 0.1 to 65.3%. We divided the 27 lesions into three groups histologically: group A with benign pleomorphic tumors (11 cases), group B with low-grade malignant tumors (5 cases), and group C with high-grade malignant tumors (11 cases). The mean PCNA index was 0.7% in group A, 2.0% in group B, and 23.1% in group C. The clinical data revealed a significantly higher local tumor recurrence and mortality rate in group C than in groups A and B. We conclude that PCNA may be used as an important indicator for determining clinical prognosis in parotid tumors.

In vitro uptake and release of TI-201 and Tc-99m MIBI in cultured tumor cells and effect of anticancer drug

201Tl is useful in the diagnosis of tumor malignancy determined by the grade of washout rate to normal tissue, especially in lung tumors and thyroid tumors. 99mTc-MIBI, a tracer of myocardial blood flow, is also a tumor tracer. We examined whether the growth of tumor cells is related to the uptake and release of these tracers in cultured tumor cells. Cultured tumor cells (HeLa cells and squamous cell carcinomas derived from human lung cancer) were incubated for 60 min with 10 kBq of either tracer for the kinetic study of cellular uptake. They were additionally incubated for 90 min with cold medium for the kinetic study of cellular release. These cells cultured with various concentrations of actinomycin D (ACD) or CDDP were used to examine the correlation between the cellular growth and kinetics of these tracers. The cellular release of 201Tl increased relative to the concentration of added ACD or CDDP in both cell types. In contrast, the cellular release of 99mTc-MIBI was not changed by the addition of ACD in HeLa cells. In conclusion, 201Tl showed a slower washout rate in high-growth tumor cells than in low-growth tumor cells; thus, it could act as an indicator of tumor malignancy by assessing its washout rate.

[Clinical usefulness of scatter and attenuation correction for brain single photon emission computed tomography (SPECT) in pediatrics]

This investigation was undertaken to study clinical usefulness of scatter and attenuation correction (SAC) of brain SPECT in infants to compare the standard reconstruction (STD). The brain SPECT was performed in 31 patients with 19 epilepsy, 5 cerebro-vascular disease, 2 brain tumor, 3 meningitis, 1 hydrocephalus and psychosis (mean age 5.0 +/- 4.9 years old). Many patients was necessary to be injected sedatives for restraining body motion after Technetium-99m hexamethylpropylene amine oxime (99mTc-HMPAO) was injected at the convulsion or rest. Brain SPECT data were acquired with triple detector gamma camera (GCA-9300 Toshiba Japan). These data were reconstructed by filtered backprojection after the raw data were corrected by triple energy windows method of scatter correction and Chang filtered method of attenuation correction. The same data was reconstructed by filtered backprojection without these corrections. Both SAC and STD SPECT images were analyzed by the visual interpretation. The uptake ratio of cerebral basal nuclei was calculated by the counts of the thalamus or lenticular nuclei divided by the cortex. All images of SAC method were excellent than that of STD method. The thalamic uptake ratio in SAC method was higher than that of STD method (1.22 +/- 0.09 > 0.87 +/- 0.22 p < 0.01). The lenticular nuclear uptake ratio in SAC method was higher than that of STD method (1.26 +/- 0.15 > 1.02 +/- 0.16 p < 0.01). Transmission scan is the most suitable method of absorption correction. But the transmission scan is not adequate for examination of children, because this scan needs a lot of time and the infants are exposed by the line source radioisotope. It was concluded that these scatter and absorption corrections were most suitable method for brain SPECT in pediatrics.

Three-dimensional CT angiography of the splenic-portal venous system by using multiple threshold display

We assessed the three-dimensional (3D) CT angiographic reconstruction of the splenic-portal venous system obtained by using multiple threshold display (MTD) in 40 patients with liver disease. In each patient, both shaded surface display(SSD) and MTD images were generated by using an Xtension with a Sun SPARCstation 20, and they were compared by two radiologists. MTD image quality was superior to that of SSD images, because MTD diminished longitudinal direction artifacts and the image depicted the small vessels clearly. Based on the above results, we consider MTD to be a useful method for 3D-CT angiography of the splenic-portal venous system.

Evaluation of uptake and release of technetium-99m MIBI SPECT of pulmonary and mediastinal lesions

We evaluated the uptake and release of Tc-99m MIBI in 7 benign and 30 malignant pulmonary and mediastinal lesions. Of the 37 patients, 13 underwent surgery; malignant involvement was examined in 21 mediastinal lymph nodes. Tl-201 SPECT was also performed in 10 patients. Tc-99m MIBI SPECT studies were performed on transverse SPECT images acquired 30 minutes and 3 hours after intravenous injection of 600 MBq of Tc-99m MIBI with three gamma camera detectors (GCA-9300A). Regions of interest were set in the area of abnormal uptake of Tc-99m MIBI and in an area of normal tissue in the contralateral lung. The uptake ratio of the lesion in the contralateral normal lung was obtained on the early image (early ratio; ER) as well as the delayed image (delayed ratio; DR). The benign lesions showed significantly lower ER (1.6 +/- 0.3) and DR (1.4 +/- 0.4) than the malignant lesions (1.9 +/- 0.5 and 1.8 +/- 0.5, respectively; both p < 0.05). There was no significant difference in the retention index (RI), calculated as RI = (DR-ER)/ER x 100. The DR obtained with Tl-201 SPECT images was significantly higher than that obtained with Tc-99m MIBI SPECT (p < 0.05). For the detection of mediastinal lymph node metastases, the early images showed sensitivity, specificity, and accuracy of 85.7%, 100%, and 95.2%, respectively, for the delayed images these values were 85.7%, 92.9%, and 90.5%, respectively. These results suggest that the uptake ratio of Tc-99m MIBI is a useful index in assessing benign or malignant pulmonary and mediastinal lesions.