Characterization of micron-size hydrogen clusters using Mie scattering.

Hydrogen clusters with diameters of a few micrometer range, composed of 108-10 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.

Randomized, double-blind, phase III trial of palonosetron versus granisetron in the triplet regimen for preventing chemotherapy-induced nausea and vomiting after highly emetogenic chemotherapy: TRIPLE study.

BACKGROUND: There has been no phase III study of comparing the efficacy of first- and second-generation 5-HT3 receptor antagonists in the triplet regimen with dexamethasone and aprepitant for preventing chemotherapy-induced nausea and vomiting after highly emetogenic chemotherapy (HEC). PATIENTS AND METHODS: Patients with a malignant solid tumor who would receive HEC containing 50 mg/m(2) or more cisplatin were randomly assigned to either palonosetron (0.75 mg) arm (Arm P) or granisetron (1 mg) arm (Arm G), on day 1, both arms with dexamethasone (12 mg on day 1 and 8 mg on days 2-4) and aprepitant (125 mg on day 1 and 80 mg on days 2-3). The primary end point was complete response (CR; no vomiting/retching and no rescue medication) at the 0-120 h period and secondary end points included complete control (CC; no vomiting/retching, no rescue medication, and no more than mild nausea) and total control (TC; no vomiting/retching, no rescue medication, and no nausea). RESULTS: Between July 2011 and June 2012, 842 patients were enrolled. Of 827 evaluable, 272 of 414 patients (65.7%) in Arm P had a CR at the 0-120 h period when compared with 244 of 413 (59.1%) in Arm G (P = 0.0539). Both arms had the same CR rate of 91.8% at the acute (0-24 h) period, while at the delayed (24-120 h) period, Arm P had a significantly higher CR rate than Arm G (67.2% versus 59.1%; P = 0.0142). In secondary end points, Arm P had significantly higher rates than Arm G at the 0-120 h period (CC rate: 63.8% versus 55.9%, P = 0.0234; TC rate: 47.6% versus 40.7%, P = 0.0369) and delayed periods (CC rate: 65.2% versus 55.9%, P = 0.0053; TC rate: 48.6% versus 41.4%, P = 0.0369). CONCLUSION: The present study did not show the superiority of palonosetron when compared with granisetron in the triplet regimen regarding the primary end point. CLINICAL TRIAL REGISTRY IDENTIFIER: UMIN000004863.

Yeast src homology region 3 domain-binding proteins involved in bud formation.

The yeast protein Bem1p, which bears two src homology region 3 (SH3) domains, is involved in cell polarization. A Rho-type GTPase, Rho3p, is involved in the maintenance of cell polarity for bud formation, and the rho3 defect is suppressed by a high dose of BEM1. Mutational analysis revealed that the second SH3 domain from the NH2 terminus (SH3-2) of Bem1p is important for the functions of Bem1p in bud formation and in the suppression of the rho3 defect. Boi2p, which bound to SH3-2 Bem1p, was identified using the two-hybrid system. Boi2p has a proline-rich sequence that is critical for displaying the Boi2p-Bem1p two-hybrid interaction, an SH3 domain in its NH2-terminal half, and a pleckstrin homology domain in its COOH-terminal half. A BOI2 homologue, BOI1, was identified as a gene whose overexpression inhibited cell growth. Cells overexpressing either BOI1 or BOI2 were arrested as large, round, and unbudded cells, indicating that the Boi proteins affect cell polarization. Genetic analysis revealed that BOI1 and BOI2 are functionally redundant and important for cell growth. delta boi1 delta boi2 cells became large round cells or lysed with buds, displaying defects in bud formation and in the maintenance of cell polarity. Analysis using several truncated versions of BOI2 revealed that the COOH-terminal half, which contains the pleckstrin homology domain is essential for the function of Boi2p in cell growth, while the NH2-terminal half is not, and the NH2-terminal half might be required for modulating the function of Bem1p. Overproduction of either Rho3p or the Rho3p-related GTPase Rho4p suppressed the boi defect. These results demonstrate that Rho3p GTPases and Boi proteins function in the maintenance of cell polarity for bud formation.

Discordant regulation of human type I collagen genes by prostaglandin E2.

We examined the expression of type I collagen genes in prostaglandin E2 (PGE2)-treated human lung fibroblast cultures. Addition of PGE2 to fibroblast cultures inhibited alpha 1(I) mRNA levels by approx. 25% after 6 h and 60% after 24 h. Further studies showed that dibutyryl cAMP did not inhibit alpha 1(I) mRNA levels and that cycloheximide blocked the inhibitory effect of PGE2. In contrast, PGE2 treatment with or without cycloheximide did not affect alpha 2(I) mRNA levels. Moreover, in vitro translation of RNA derived from untreated and PGE2-treated cells yielded similar amounts of alpha 2(I) collagen peptides. Taken together, these results suggest that PGE2 induces a protein which inhibits alpha 1(I) transcription through distinct regulatory elements not under the control of cAMP and provide further evidence that the type I collagen genes can be discordantly regulated.

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.

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.

Critical role of the neural pathway from the intermediate medial mesopallium to the intermediate hyperpallium apicale in filial imprinting of domestic chicks (Gallus gallus domesticus).

Filial imprinting in precocial birds is a useful model for studying early learning and cognitive development, as it is characterized by a well-defined sensitive or critical period. We recently showed that the thyroid hormone 3,5,3'-triiodothyronine (T3) determines the onset of the sensitive period. Moreover, exogenous injection of T3 into the intermediate medial mesopallium (IMM) region (analogous to the associative cortex in mammals) enables imprinting even on post-hatch day 4 or 6 when the sensitive period has been terminated. However, the neural mechanisms downstream from T3 action in the IMM region remain elusive. Here, we analyzed the functional involvement of the intermediate hyperpallium apicale (IMHA) in T3 action. Bilateral excitotoxic ablation of the IMHA prevented imprinting in newly hatched chicks, and also suppressed the recovery of the sensitive period by systemic intra-venous or localized intra-IMM injection of T3 in day-4 chicks. In contrast to the effect in the IMM, direct injection of T3 into the IMHA did not enable imprinting in day-4 chicks. Moreover, bilateral ablation of IMHA after imprinting training impaired recall. These results suggest that the IMHA is critical for memory acquisition downstream following T3 action in the IMM and further, that it receives and retains information stored in the IMM for recall. Furthermore, both an avian adeno-associated viral construct containing an anterograde tracer (wheat-germ agglutinin) and a retrograde tracer (cholera toxin subunit B) revealed neural connections from the IMM to the IMHA. Taken together, our findings suggest that hierarchical processes from the primary area (IMM) to the secondary area (IMHA) are required for imprinting.

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.

Effect of dipicolinate, a chelator of zinc, on bone protein synthesis in tissue culture. The essential role of zinc.

The present investigation was undertaken to clarify the essential role of zinc on bone protein synthesis in tissue culture. Calvariae were removed from 3-week-old male rats and cultured for periods up to 72 hr in Dulbecco's Modified Eagle Medium (high glucose, 4500 mg/dl) supplemented with antibiotics and bovine serum albumin. The calvariae were incubated for 24 hr at 37 degrees in 5% CO2/95% air in medium containing 10(-6)-10(-3) M dipicolinate, a chelator of zinc, and then the bones were transferred into medium containing either 10(-4) M zinc sulfate or vehicle without dipicolinate. Zinc content in bone tissues was decreased when the culture was treated with 10(-4) and 10(-3) M dipicolinate for 24 hr. When calvariae treated with 10(-4) M dipicolinate for 24 hr were further cultured in medium without dipicolinate for 24 and 48 hr, bone alkaline phosphatase activity was decreased by about 40% (P less than 0.01) of untreated bone enzyme activity. The decreased alkaline phosphatase activity was increased markedly by the presence of 10(-4) M zinc (about 2.5-fold of control value). This effect of zinc was blocked completely by the presence of 10(-7) M cycloheximide, but 10(-8) M actinomycin D caused only a partial inhibition. When calvariae treated with 10(-4) M dipicolinate were pulsed with [3H]proline, the incorporation of [3H]proline into the acid-insoluble residues of bone tissue was decreased by about 40% (P less than 0.01) of the value obtained from calvariae not treated with dipicolinate. The presence of 10(-4) M zinc caused an increase of about 2-fold in [3H]proline incorporation. Bone DNA content was not altered significantly by treatment with 10(-4) dipicolinate or 10(-4) M zinc. These results clearly indicate that endogenous zinc induces the stimulation of protein synthesis at the translational process in bone cells. The present study further supports the view that zinc plays an essential role for protein synthesis in bone cells.

Evaluation of an artificial dermis full-thickness skin defect model in the rat.

An artificial dermis product was applied to full-thickness skin defects in rats and cell infiltration into the collagen matrix was investigated. Host fibroblasts and capillaries infiltrated as far as the upper end of the collagen matrix by day 14 after application. Determination of glycosaminoglycan levels in the matrix showed that hyaluronic acid was generated in a similar amount to that seen in the intact skin by day 14. An autologous thin split-thickness skin graft was placed onto the artificial dermis simultaneously or several days after its application to the defect. The take rate was 100% when a split-thickness skin graft was performed on day 14 after application of the artificial dermis. At 6 weeks after the skin defect was created, the wound area was 80% of the original area and the dermis at the grafted site was as thick as that of normal skin. These results suggested that the artificial dermis provides a good matrix for thin split-thickness skin graft and is useful for the reconstruction of full-thickness skin defects. This method is considered to be an alternative to the conventional procedure using thick skin grafts or skin flaps.

Histological evaluation of skin reconstruction using artificial dermis.

An artificial dermis, composed of a collagen matrix, was applied to a full-thickness skin defect prepared on the back of rats. Two weeks later, a thin split-thickness skin autograft was overlaid on the matrix at each recipient site. The dermal layer at the recipient sites was 1.02 mm thick with prior application of artificial dermis, as compared with the 0.46 mm thickness observed without such pretreatment. Histologically, the split-thickness skin graft normally lies with no gap on the artificial dermis, which looks like natural dermis. Six days after grafting, the epithelial basal cells in the grafts showed an active uptake of bromodeoxyuridine (a thymidine analogue), indicating high activity of cell proliferation. About 50 and 20% respectively of the artificial dermis remained at each recipient site at 12 and 20 weeks after its application (after the skin defect). This finding indicates that bovine collagen, which is a constituent of the artificial dermis, is gradually replaced by the host tissue.

Role of calmodulin as an endogenous initiatory factor in compensatory lung growth after pneumonectomy.

Compensatory lung growth after pneumonectomy is a well established phenomenon in young humans and experimental animals. To date, the cellular initiating and/or regulatory factor(s) responsible for this growth response have yet to be established. We have studied changes in lung content and activity of calmodulin, a calcium-dependent regulatory protein in relation with lung mass and DNA content during postpneumonectomy compensatory lung growth in 4-week-old rats. We observed that after left pneumonectomy, right lung calmodulin content (measured by radioimmunoassay) and calmodulin activity (measured by cyclic nucleotide phosphodiesterase activation) were increased at days 1 and 2 after surgery in the pneumonectomized rats, preceding the increase of lung mass and DNA content which started at day 3. Treatment of the pneumonectomized rats with a highly specific calmodulin antagonist, trifluoperazine, immediately after the surgery, resulted in diminished lung calmodulin activity, sparing the calmodulin content, and in concomitant reduction of lung mass and DNA content to values intermediate between those of controls and the pneumonectomized animals. Based on these findings, we conclude that calmodulin may be an important intracellular (possibly, autocrine) initiatory or facilitatory factor in compensatory hyperplastic lung growth after pneumonectomy.

In vitro branching morphogenesis of the fetal rat lung.

We studied the pattern of airways branching in the fetal rat lung in vitro. Lung primordia of gestational ages 13, 14, and 15 days were allowed to grow in culture to a gestational age equivalent to 21 days. The first generation airways appear by a single new bud (monopodial budding) from the left main airway (lateral appearing before the medial). They elongate to form branches and then bud dichotomously (2 buds occurring simultaneously and adjacent to each other) at their tips. Then monopodial branching takes place along their sides. The same cycle of budding and branching seems to be repeated for the following generation of the airways. The total number of the peripheral (subpleural) buds was greatest in the day 15 explants and least in day 13 explants throughout the whole culture period, but the statistical model used indicated faster budding in the 13 day explants. Morphometric assessment showed no difference in the ratios between the lung components in the 3 age groups and that the peripheral epithelial measurements were the same in the 3 groups at an equivalent gestational age of 21 days. We have also shown that lobes do not form in the right lung, although appropriate airways do. This may indicate the importance of mesothelial covering of the lung in the process of lobe formation. The method is useful for studying the control of lung morphogenesis.

Connective tissue, mechanical, and morphometric changes in the lungs of weanling rats fed a low protein diet.

We studied the effect of low-protein diet (8% casein) on lung growth in rats from 3 to 7 weeks of age. Their diet was isocaloric with that of control animals fed a diet of 20% casein. The calorie intake of experimental animals was increased during the first 3 weeks of the experiment, but they increased less (about 10%) in body weight, had less protein and less water when the whole body was examined, and had lower serum proteins and decreased urinary hydroxyproline. The experimental animals remained in positive nitrogen balance by maintaining low urinary nitrogen excretion. The lungs of the experimental animals were abnormal, with decreased absolute amounts of hydroxyproline and desmosine and of these relative to unit lung weight. The lungs contained more air per gram of lung tissue, and the volume of air in the lung was increased at all transpulmonary pressures above zero. When corrected for increased total lung capacity, there was a loss of recoil at mid-lung volumes. Saline-filled volume-pressure curves, corrected for lung volume, showed similar loss of recoil. Alveolar multiplication was quantitatively normal, but the experimental animals had larger alveoli. We conclude that the protein deprivation in isocalorically fed animals has a specific effect on lung scleroprotein content, which may be due to diminished synthesis, and this results in both structural and functional abnormalities in the lung. Our results indicate the importance of dietary protein in lung development and possibly as one of the causes of emphysema. Further studies are needed to know whether this would be a problem in infants of Kwashiokor.

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.

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.

Evaluation of the ventilation-perfusion ratio in lung diseases by simultaneous anterior and posterior image acquisition.

Ventilation and perfusion images were acquired during tidal breathing using 81mKr gas and 99mTc-MAA. Anterior and posterior functional images of V/Q and Q/V were simultaneously acquired in 34 subjects with various lung diseases and 6 healthy controls. Superimposed anterior and posterior images were constructed and histograms of the frequency distribution for ventilation, perfusion, and the V/Q ratio were displayed for both lungs as well as for the left and right lungs individually. Blood gas analysis and general lung function tests were also performed on the day before scintigraphy. A correlation between marked uneven distribution of V/Q and A-aDO2 was found. When the proportion of counts at V/Q < 0.67 and/or V/Q > 1.50 in the V/Q counts histogram was compared with A-aDO2, there was a significant positive correlation for anterior images (r = 0.684, p < 0.05), posterior images (r = 0.654, p < 0.05) and superimposed images (r = 0.696, p < 0.05). Superimposed images therefore showed the highest correlation. There was no correlation between the results of lung function testing and A-aDO2. Coronal SPECT images were also obtained in 15 patients and compared with the superimposed anterior and posterior planar images. There was a good correlation (r = 0.888, p < 0.001) between both the imaging methods regarding the marked uneven distribution of V/Q. Simultaneous anterior and posterior planar image acquisition reduces the examining time, is simple, and is noninvasive. The present results also suggest that it is useful for quantitative evaluation of the ventilation-perfusion ratio.

Evaluation of Tl-201 SPECT for monitoring the treatment of pulmonary and mediastinal tumors.

Tl-201 single photon emission computed tomography (SPECT) was performed in 88 patients with pulmonary or mediastinal tumors in order to evaluate its usefulness for the detection of disease and for the assessment of the effect of treatment. We also examined mediastinal and hilar lymph node metastasis from lung cancer. Tl-201 SPECT showed abnormal accumulation on delayed images in all lung cancer patients with tumor diameters more than 12 mm. In the 14 operated lung cancer patients, mediastinal and hilar lymph node metastases with diameters of more than 15 mm were imaged, but one with a diameter of 9 mm was missed. The retention index (RI) was 27.52 +/- 31.58 in malignant tumors and -13.67 +/- 8.15 in benign tumors (p < 0.05). The RI was significantly lower after treatment than before treatment. The interval until tumor recurrence or reactivation tended to be longer in patients who showed a significant decrease in the RI after therapy. These findings suggest the usefulness of the RI as an index of therapeutic efficacy.

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.

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.