Evaluation of the fat plane of the pancreatic groove using multidetector CT.

AIM: To assess the pancreatic groove fat plane in the normal population and compare this with the fat plane in patients with groove pancreatitis or carcinoma using multidetector computed tomography (CT). MATERIAL AND METHODS: The pancreatic groove fat plane was evaluated retrospectively in 460 normal subjects (normal group), and in 25 patients with groove pancreatitis or carcinoma (pathology group) using 5 mm- and 1 mm-thick slices of unenhanced axial multidetector CT images. Two investigators independently assessed the degree of pancreatic groove fat plane visualisation using a four-point scale (grade 1: visualisation of 0-25%, grade 2: 26-50%, grade 3: 51-75%, grade 4: 76-100%). Pancreatic parenchymal condition, age, sex, body mass index, diabetes mellitus, and dyslipidaemia were also evaluated. RESULTS: The interobserver agreement for the visualisation grades was almost perfect (k-value = 0.95). In the normal group, grade 4 visualisation of the pancreatic groove fat plane was more common in those aged >80 years (78.6%) compared with younger age groups. Pancreatic atrophy and fatty infiltration significantly improved fat plane visualisation. In the pathology group, grade 4 visualisation of the pancreatic groove fat plane was not seen in either groove carcinoma or pancreatitis. A cut-off point of ≤50% visualisation of the pancreatic groove fat plane showed 95% sensitivity and 82% specificity for detecting possible abnormalities in older patients (>60 years). The clinical factors investigated were not significantly related to pancreatic groove fat plane visualisation. CONCLUSION: Pancreatic groove fat plane visualisation could be a good predictor for detecting groove abnormalities.

A randomized phase II study of S-1 plus oral leucovorin versus S-1 monotherapy in patients with gemcitabine-refractory advanced pancreatic cancer.

BACKGROUND: We evaluated the efficacy and toxicity of adding oral leucovorin (LV) to S-1 when compared with S-1 monotherapy in patients with gemcitabine-refractory pancreatic cancer (PC). PATIENTS AND METHODS: Gemcitabine-refractory PC patients were randomly assigned in a 1:1 ratio to receive S-1 at 40, 50, or 60 mg according to body surface area plus LV 25 mg, both given orally twice daily for 1 week, repeated every 2 weeks (SL group), or S-1 monotherapy at the same dose as the SL group for 4 weeks, repeated every 6 weeks (S-1 group). The primary end point was progression-free survival (PFS). RESULTS: Among 142 patients enrolled, 140 were eligible for efficacy assessment (SL: n = 69 and S-1: n = 71). PFS was significantly longer in the SL group than in the S-1 group [median PFS, 3.8 versus 2.7 months; hazard ratio (HR), 0.56; 95% confidence interval (CI), 0.37-0.85; P = 0.003]). The disease control rate was significantly higher in the SL group than in the S-1 group (91% versus 72%; P = 0.004). Overall survival (OS) was similar in both groups (median OS, 6.3 versus 6.1 months; HR, 0.82; 95% CI, 0.54-1.22; P = 0.463). After adjusting for patient background factors in a multivariate analysis, OS tended to be better in the SL group (HR, 0.71; 95% CI, 0.47-1.07; P = 0.099). Both treatments were well tolerated, although gastrointestinal toxicities were slightly more severe in the SL group. CONCLUSION: The addition of LV to S-1 significantly improved PFS in patients with gemcitabine-refractory advanced PC, and a phase III trial has been initiated in a similar setting. CLINICAL TRIALS NUMBER: Japan Pharmaceutical Information Center: JapicCTI-111554.

Theoretical and experimental study on two-stage-imaging microscopy using ellipsometric contrast for real-time visualization of molecularly thin films.

A two-stage-imaging ellipsometric-contrast microscope (TIEM) has been developed to measure the distribution of film thickness over a wide area of molecularly thin liquid films with a high lateral resolution, wide field of view, high thickness resolution, and high-speed. Moreover, this ellipsometric microscope enables us to achieve simultaneous measurements with other measurement apparatuses. We present the principle used to parallelize an object image to an imaging sensor and to reduce the incident angle entering the imaging sensor. In addition, we discuss the characteristic shape deformation of the object image due to oblique observation. The performance of the actual setup for TIEM was experimentally studied. A lateral resolution of about 1 µm was obtained by measuring the modulation transfer function of the TIEM. We also found that the shape deformation approximately agreed with that from theory. Furthermore, for molecularly thin films, we confirmed linearity between the film thickness and the light intensity measured with TIEM, which enables us to quantify the thickness of the films. TIEM can open up a new field of real-time imaging of thin films such as visualization of a liquid lubricant film under shear.

Carcinoid tumors of the pancreas: dynamic CT and MRI features with pathological correlation.

BACKGROUND: Carcinoid tumor of the pancreas is rare, and there are few reports that described its CT or magnetic resonance imaging (MRI) findings. We describe the characteristic CT and MRI findings in four cases of carcinoid tumor of the pancreas. METHODS: Radiologic and pathologic features were analyzed in four patients. All patients underwent triple-phase dynamic CT and MRI. RESULTS: The tumor size in the four cases ranged 15-20 mm and intratumoral calcification was detected in one case. On triple-phase dynamic CT, the peak enhancement of the tumors was seen at the arterial dominant phase in three cases; the remaining one was at the portal venous phase with prolonged contrast-enhancement effect. The tumors showed low to high signal intensity on T2-weighted images. Dilatation of the main pancreatic ducts (MPDs) distal to the tumors was seen in three cases, in which tumor invasion into the MPDs was pathologically confirmed. Furthermore, the tumors having mild to severe fibrosis pathologically invaded into the peripancreatic lymphatics or nerves. CONCLUSION: It would be characteristic of carcinoid tumor of the pancreas to be well enhanced at the arterial dominant phase on dynamic CT, and to highly invade into the MPDs and the peripancreatic lymphatics or nerves.

Adenomatoid tumour of the liver.

An unusual primary adenomatoid tumour arising in the normal liver is described. Hepatectomy was performed, and the patient is alive and free of disease 1 year postsurgery. Grossly, the tumour showed a haemorrhagic cut surface with numerous microcystic structures. Histological examination revealed cystic or angiomatoid spaces of various sizes lined by cuboidal, low-columnar, or flattened epithelioid cells with vacuolated cytoplasm and round to oval nuclei. The epithelioid cells were entirely supported by proliferated capillaries and arteries together with collagenous stroma. Immunohistochemical studies showed that the epithelioid cells were strongly positive for a broad spectrum of cytokeratins (AE1/AE3, CAM5.2, epithelial membrane antigen and cytokeratin 7) and mesothelial markers (calretinin, Wilms' tumour 1 and D2-40). These cells were negative for Hep par-1, carcinoembryonic antigen, neural cell adhesion molecule, CD34, CD31 and HMB45. Atypically, abundant capillaries were observed; however, the cystic proliferation of epithelioid cells with vacuoles and immunohistochemical profile of the epithelioid element were consistent with hepatic adenomatoid tumour.

Enhancement of nitric oxide and superoxide generations by alpha-tocopheryl succinate and its apoptotic and anticancer effects.

Tocopheryl succinate (TS), a succinyl ester of alpha-tocopherol (alpha-T), has been reported to have various biological activities. In this communication, we review the current findings about TS including our recent studies of its effects on nitric oxide (NO) and superoxide (O2-) generations implicated in cancer and atherosclerosis. First, we investigated the effect of TS on NO production in vascular smooth muscle cells (VSMC) under atherosclerosis-like conditions using lipopolysaccharide (LPS) and interferon-gamma (IFN). TS enhanced LPS/IFN-dependent NO production, but alpha-T itself did not. The enhancement by TS of NO production was inhibited by alpha-T but not by antioxidants such as ascorbic acid and 2[3]-t-butyl-4-hydroxyanisole (BHA). TS enhanced the amount of protein kinase Calpha (PKCalpha) in VSMC, and PKC inhibitors inhibited TS-enhanced NO production, suggesting that the enhancing effect of TS on NO production is caused by up-regulation of PKC. Second, we found that TS induced apoptosis in VSMC associated with increase in O2- generation via NADPH-dependent oxidase. We further observed that a mouse breast cancer cell line C127I was more susceptible for TS-induced apoptosis than a mouse breast normal cell line NmuMG, and that superoxide dismutase, alpha-T, and BHA inhibited TS-caused morphological cell damage in C127I. From these results, O2- itself and/or other reactive oxygen species are assumed to associate with TS-induced cell toxicity, and antioxidative defense systems are supposed to be lowered in cancer cells. Finally, we found that intravenous injection of TS vesicles completely inhibited the growth of melanoma cells B16-F1 inoculated on the back of hairless mice and enhanced their survival time.

Novel antioxidants isolated from plants of the genera Ferula, Inula, Prangos and Rheum collected in Uzbekistan.

We examined the effects of 48 compounds isolated from Ferula pallida, F. penninervis, Inula macrophylla, Prangos pabularia, P. tschimganica and Rheum maximowiczii collected in Uzbekistan on ADP/Fe2+-induced lipid peroxidation of egg yolk phosphatidylcholine liposomes. Of those compounds, 23 inhibited ADP/Fe2+-induced lipid peroxidation and nine showed especially strong inhibition of lipid peroxidation. Most compounds that inhibited peroxidation scavenged the 1,1'-diphenyl-2-picrylhydrazyl (DPPH) radical, indicating that the inhibition was due to radical scavenging. However, some compounds did not scavenge DPPH but inhibited lipid peroxidation significantly, suggesting that their inhibitory effect was not due to radical scavenging but to some other mechanism, such as prevention of Fe2+ function. Thus, we found various new antioxidants, some of which had a unique mechanism of action, in Ferula, Inula, Prangos and Rheum plants collected in Uzbekistan as seeds used in medicine.

Molecular characteristics of astaxanthin and beta-carotene in the phospholipid monolayer and their distributions in the phospholipid bilayer.

The molecular characteristics of the monolayers of astaxanthin with polar group on the beta-ionone ring in the molecule and beta-carotene without polar group and their interactions in mixed carotenoid-phospholipid monolayers and the effects of carotenoids on the phase behavior of the phospholipid bilayers were examined by the monolayer technique and differential scanning calorimetry (DSC). We found from the monolayer study that beta-carotene had an amphiphilic nature. The molecular assembly of astaxanthin in the monolayer at the hydrophobic/hydrophilic interface was more stable than that of beta-carotene. Dimyristoylphosphatidylcholine (DMPC) in the monolayer was miscible with astaxanthin in the range of 0-0.4 mol fractions of astaxanthin, but not fully miscible with beta-carotene even at low concentrations below 0.1 mol fraction of beta-carotene. Surface potential and compression/expansion cycles of beta-carotene monolayer indicated the formation of molecular aggregates by itself. DSC study showed that when small amount of astaxanthin was added, the transition temperature of dipalmitoylphosphatidylcholine (DPPC) was markedly shifted to lower temperatures and that the transition peak was asymmetrically broadened, indicative of a significant depression in cooperativity of the gel to liquid-crystalline transition. The asymmetric DSC endothermic bands of DPPC incorporating small amounts of astaxanthin were well fit by deconvolution into two to three domains containing different concentrations of astaxanthin. On the contrary, the incorporation of beta-carotene resulted in a small depression of the main transition temperature with a slight broadening of the transition peak, suggesting a small miscibility of beta-carotene with the phospholipid bilayer or a formation of aggregates of beta-carotene in the membranes. These results suggest that there would be a high localized concentration in the phase separated membrane for astaxanthin or beta-carotene to function effectively as scavenger.

Superoxide is responsible for apoptosis in rat vascular smooth muscle cells induced by alpha-tocopheryl hemisuccinate.

We investigated the mechanism of cell toxicity of alpha-tocopheryl hemisuccinate (TS). TS concentration- and time-dependently induced the lactate dehydrogenase release and DNA fragmentation of rat vascular smooth muscle cells (VSMC). Exogenous addition of superoxide dismutase, but not catalase, significantly inhibited the cell toxicity of TS. The NADPH-dependent oxidase activity of VSMC was stimulated by TS treatment. The cell toxicity of TS was inhibited by NADPH oxidase inhibitor 4-(2-aminoethyl)-benzenesulfonyl fluoride. Consequently, TS-induced apoptosis of VSMC was suggested to be caused by exogenous O(2)(-) generated via the oxidase system activated with TS.

Gastrectomized patients are in a state of chronic protein malnutrition analyses of 23 amino acids.

BACKGROUND/AIMS: Malnutrition is one of the major postoperative complications of radical subtotal or total gastrectomy for gastric cancer. This study was conducted to clarify the nutritional consequences of radical gastrectomy with respect to protein metabolism. METHODOLOGY: To evaluate the nutritional status and the abnormalities in protein metabolism in such cases, serum concentrations of 23 amino acids were measured by high performance liquid chromatography in 40 patients who had undergone either subtotal (n = 20) or total (n = 20) gastrectomy more than 6 months prior to this analysis. RESULTS: Serum concentrations of total amino acids and nonessential amino acids were the same between gastrectomized patients and healthy controls (n = 50). However, concentrations of essential amino acids, essential amino acid/nonessential amino acid and branched-chain amino acid/total amino acid ratios were significantly lower in patient groups than in normal controls. Each essential amino acid was decreased and concentrations of glutamate and citrulline were increased in both patient groups compared with controls. The major differences between patients with subtotal and total gastrectomies included an increased ornithine and a decreased arginine concentration in patients with subtotal gastrectomy. CONCLUSIONS: These changes suggest that malabsorption of protein from the intestinal tract causes persistent proteolysis in the skeletal muscle for long periods of time after surgery in these patients and that changes in ornithine and citrulline levels may reflect more severe alterations in those with total gastrectomy.

A comparative study of the ability of ferric nitrilotriacetate [correction of nitriloacetate] and other iron chelators to assist membrane lipid peroxidation by superoxide radicals.

This study examined some of the variables determining the efficiency of lipid peroxidation in egg yolk phosphatidylcholine liposomes and in microsomes exposed to enzymatically-generated superoxide radicals. The initiation of peroxidation required the presence of preformed lipid peroxides and a chelated metal catalyst. Comparison of the relative effectiveness of four iron chelating agents showed that the chelate must bind to the membrane by coulombic attraction between the charged membrane and a chelate carrying an opposite net charge. Of the chelates tested, only the carcinogenic ferric nitrilotriacetate [corrected] (Fe(3+)-NTA) was an effective catalyst of oxidation of all membranes, whether carrying a net charge, or not. We postulate that the unique catalytic capacity of the ferric nitrilotriacetate [corrected] (Fe(3+)-NTA) can be explained by its existence in two forms at neutral pH, each binding to oppositely charged membranes and initiating their peroxidation. This gives the complex the unique ability to bind to any membrane, which may be a factor in its carcinogenicity.

Preventive effects of lecithinized superoxide dismutase and methylprednisolone on spinal cord injury in rats: transcriptional regulation of inflammatory and neurotrophic genes.

The effects of lecithinized superoxide dismutase (PC-SOD) and/or methylpredisolone (MP) in preventing secondary pathological changes after spinal cord injury (SCI) were investigated in rats with reference to recovery of hindlimb motor function and expression of mRNA of pro-inflammatory and neurotrophic genes. Hindlimb motor function was assessed as the BBB open field locomotor scores. The BBB scores of three groups treated with either PC-SOD (40,000 units/kg), MP (30 mg/kg), or a combination of PC-SOD and MP (PC-SOD+MP) increased with time until 3 days after SCI, and were significantly higher than that of the control group (p < 0.05). Thereafter, the score of the PC-SOD group increased, whereas that of the MP group showed a temporary decrease from day 3 to 5 and then it gradually recovered. The scores in all groups reached a plateau about 18 days after SCI. The PC-SOD+MP group did not show a synergism but a tendency similar to that of the MP group. PC-SOD and MP had down-regulatory effects on mRNA expression of pro-inflammatory substances such as interleukin-1beta (IL-1beta), intercellular adhesion molecule-1 (ICAM-1), and inducible-nitric oxide synthetase (i-NOS) after spinal cord compression at 3, 6, and 24 h, respectively, as judged by a semiquantitative reverse transcription-polymerase chain reaction and on the lipid peroxide (LPO) level 1 h after injury as determined by thiobarbituric acid-reactive substances. The suppression of pro-inflammatory genes expression, especially IL-1beta were greater in the MP group than in the PC-SOD group, while suppression of LPO level was similar in these two groups. PC-SOD+MP treatment augmented the suppression of all three pro-inflammatory genes expression and the decrease of the LPO level. The level of neurotrophin-3 (NT-3) mRNA increased from 6 h after SCI and reached a maximum after 48 h. NT-3 mRNA level was enhanced by PC-SOD treatment, but not by MP treatment. Thus, the effect of MP in suppressing these pro-inflammatory genes expression was more than that of PC-SOD. The difference in motor function in the early and later stage may be partially due to differences in expression of IL-1beta and NT-3 after either treatment, through an IL-1beta-dependent or NT-3-mediated repair response.

Somesthetic disconnection syndromes in patients with callosal lesions.

Somesthetic disconnection syndromes were investigated in relation to the sites of lesions in the corpus callosum in 3 patients with callosal lesions, in order to identify the callosal regions responsible for the interhemispheric transfer of somesthetic information. Cases 1 and 2 with lesions in the posterior truncus exhibited transfer deficits of discriminative sensations between the left and right hands, left-sided tactile anomia and left-sided somesthetic alexia. Case 3 with lesions in the posteroventral part of the posterior truncus showed no signs of somesthetic disconnection syndromes. The results suggest the importance of the anterior and/or dorsal part of the posterior truncus of the corpus callosum for interhemispheric transfer of the discriminative sensations and integrated somesthetic information necessary for tactile naming and somesthetic reading.

Structural identification of phosphatidylcholines having an oxidatively shortened linoleate residue generated through its oxygenation with soybean or rabbit reticulocyte lipoxygenase.

Phosphatidylcholines (PCs) with platelet-activating factor (PAF)-like biological activities are known to be generated by fragmentation of the sn-2-esterified polyunsaturated fatty acyl group. The reaction is free radical-mediated and triggered by oxidants such as metal ions, oxyhemoglobin, and organic hydroperoxides. In this study, we characterized the PAF-like phospholipids produced on reaction of PC having a linoleate group with lipoxygenase enzymes at low oxygen concentrations. When the oxidized PCs were analyzed by gas chromatography-mass spectrometry, two types of oxidatively fragmented PC were detected. One PC had an sn-2-short chain saturated or unsaturated acyl group (C(8)-C(13)) with an aldehydic terminal; the abundant species were PCs with C(9) and C(13). The other PC had a short chain saturated acyl group (C(6)-C(9)) with a methyl terminal, and the most predominant species was PC with C(8). When the extracts of oxidation products were subjected to catalytic hydrogenation, PCs having saturated acyl groups (C(6)-C(14)) were detected; the most abundant was C(12) species. The less regiospecific formation of PAF-like lipids suggests that they were generated by oxidative fragmentation of PC hydroperoxides formed by non-stereoselective oxygenation of the alkyl radical of esterified linoleate that escaped from the active centers of lipoxygenases. One of the PAF-like PC with an aldehydic terminal was found to be bioactive; it inhibited the production of nitric oxide induced by lipopolysaccharide and interferon-gamma in vascular smooth muscle cells from rat aorta.

Expression of facilitative glucose transporter 1 mRNA in colon cancer was not regulated by k-ras.

The expression of facilitative glucose transporter isoforms in colon adenocarcinoma and the possible role of k-ras in inducing GLUT (glucose transporter) mRNA were studied. RT-PCR demonstrated GLUT2 and GLUT3 expression in 100% of the ten normal colon mucosa samples but detected no GLUT1 mRNA. By contrast, GLUT1 mRNA was detected in all 20 (100%) colon cancer samples examined. GLUT4 mRNA was not detected in either normal mucosa or colon cancer tissues. Semiquantitative PCR demonstrated equal amounts of GLUT2 and GLUT3 mRNA in both normal mucosa and colon cancer samples. A point mutation in codon 12 of k-ras was detected in only six of the 20 (30%) colon cancer samples. Thus, a major difference between normal colon epithelia and colon cancer was the acquisition of GLUT1 expression, which was unlikely to have been induced by a point mutation in codon 12 of k-ras.

Platelet-activating factor (PAF)-like oxidized phospholipids: relevance to atherosclerosis.

Lipid peroxidation is involved in the pathogenesis of chronic diseases including atherosclerosis. Oxidized lipoprotein has diverse biological activities and is believed to initiate atheroma formation and maturate fatty plaque. The active components of oxidized lipoproteins still remain to be clarified, but a likely candidate is the phosphatidylcholine (PC) having an sn-2-short-chain acyl group with a methyl, hydroxyl, aldehydic or carboxylic terminal. These unique PCs, formed by oxidative fragmentation of the polyunsaturated acyl group of the parent PC in liposomes, low density lipoproteins and blood plasma, induce platelet aggregation through the activation of the receptor for platelet-activating factor (PAF), due to their resemblance in structure with PAF. We have found that PAF-like lipids regulate DNA synthesis and production of nitric oxide independently of the activation of the PAF receptor in vascular smooth muscle cells. Regulation of vascular cell function through two distinct signaling pathways mediated by PAF-like lipids provides new insight into the mechanism of induction of atherosclerosis.

7.5-MHz data-transfer rate with a planar aperture mounted upon a near-field optical slider.

We fabricated a planar aperture-mounted (PAM) slider by use of a focused ion beam to demonstrate fast data acquisition for near-field optical data storage. The aperture (200 nm x 500 nm) was formed upon the Ti-coated air-bearing surface of the slider and was directly illuminated with a laser (lambda = 532 nm) beam spot by use of an objective lens (N.A., 0.55). The light transmitted through the aperture was modulated by a Ti-coated SiO(2) disk with 200- and 400-nm-wide line-and-space (L&S) patterns engraved by electron-beam lithography. The optical throughput of the taperless aperture was greater than 0.02. By use of the PAM slider, 400- and 200-nm L&S signals were detected at linear velocities of 6 and 3 m/s, respectively, corresponding to a data-transfer rate of 7.5 MHz.