Spin caloritronics in metallic superlattices

Spin caloritronics, a research field studying on the interconversion between a charge current (Jc) and a heat current (Jq) mediated by a spin current (Js) and/or magnetization (M), has attracted much attention not only for academic interest but also for practical applications. Newly discovered spin-caloritronic phenomena such as the spin Seebeck effect (SSE) have stimulated the renewed interest in the thermoelectric phenomena of a magnet, which have been known for a long time, e.g. the anomalous Nernst effect (ANE). These spin-caloritronic phenomena involving the SSE and the ANE have provided with a new direction for thermoelectric conversion exploitingJsand/orM. Importantly, the symmetry of ANE allows the thermoelectric conversion in the transverse configuration betweenJqandJc. Although the transverse configuration is totally different from the conventional longitudinal configuration based on the Seebeck effect and has many advantages, we are still facing several issues that need to be solved before developing practical applications. The primal issue is the improvement of conversion efficiency. In the case of ANE-based applications, a material with a large anomalous Nernst coefficient (SANE) is the key for solving the issue. This review article introduces the increase ofSANEcan be achieved by forming superlattice structures, which has been demonstrated for several kinds of materials combinations. The overall picture of studies on spin caloritronics is first surveyed. Then, we mention the pioneering work on the transverse thermoelectric conversion in superlattice structures, which was performed using Fe-based metallic superlattices, and show the recent studies for the Ni-based metallic superlattices and the ordered alloy-based metallic superlattices.

Feasibility and safety of 0.6% sodium alginate in endoscopic submucosal dissection for colorectal neoplastic lesion: A pilot study

Objectives

The usefulness of 0.6% sodium alginate (SA) as a submucosal (SM) injection solution for endoscopic SM dissection (ESD) has gained attention over the past few years. However, using ESD for colorectal neoplastic lesions is not explicitly researched as yet. Thus, we conducted this study to determine the feasibility and safety of 0.6% SA solution for colorectal ESD.

Methods

In this single-center, retrospective pilot study, a total of 100 cases treated with ESD using 0.6% SA as a SM injection solution for colorectal neoplasia at our institute were retrospectively reviewed to clarify the clinical feasibility and safety of 0.6% SA. The primary endpoint was to evaluate the complication rate, and the secondary endpoint was to determine the procedure time and the amount of solution used.

Results

Intraoperative perforation was observed in 1 case (1.0%), 2 cases (2.0%) presented with postprocedural hemorrhage, and no lethal adverse events were observed. The median ESD procedure times were 39.5 min (10-150), and the amount of solution used was less than 20 mL in 67 cases (67.0%). En-bloc resection could be achieved in 97 cases (97.0%). Although six cases underwent subsequent surgery due to the deep SM invasion (>1000 μm), there were no cases with nodal involvement, confirmed through histopathological evaluation.

Conclusions

Our findings indicate that 0.6% SA can potentially ensure safe and secure ESD for colorectal neoplasia.

Influence of the strain effect on magnetocrystalline anisotropy in Co2Fe0.4Mn0.6Si Heusler alloys

The perpendicular magnetocrystalline anisotropy, magnetoelastic properties as well as the Gilbert damping factor in Co2Fe0.4Mn0.6Si thin films were found to depend on a magnetic layer thickness, and they can be also tuned by the application of additional Ag buffer layer. The tetragonal distortion of a magnetic layer was found to increase with decreasing thickness, and after the application of an additional Ag buffer layer, the character of this distortion was changed from tensile to compressive in the plane of a film. A correlation between the tetragonal distortion and perpendicular magnetocrystalline anisotropy was found. However, the magnitude of the observed tetragonal distortion for most samples seems to be too small to explain alone the experimentally found large magnitude of the perpendicular magnetocrystalline anisotropy. For these samples, other mechanisms including both surface and volume effects must be taken into account.

Computer-aided diagnosis of early-stage colorectal cancer using nonmagnified endoscopic white-light images (with videos)

BACKGROUND AND AIMS

Differentiation of colorectal cancers (CRCs) with deep submucosal invasion (T1b) from CRCs with superficial invasion (T1a) or no invasion (Tis) is not straightforward. This study aimed to develop a computer-aided diagnosis (CADx) system to establish the diagnosis of early-stage cancers using nonmagnified endoscopic white-light images alone.

METHODS

From 5108 images, 1513 lesions (Tis, 1074; T1a, 145; T1b, 294) were collected from 1470 patients at 10 academic hospitals and assigned to training and testing datasets (3:1). The ResNet-50 network was used as the backbone to extract features from images. Oversampling and focal loss were used to compensate class imbalance of the invasive stage. Diagnostic performance was assessed using the testing dataset including 403 CRCs with 1392 images. Two experts and 2 trainees read the identical testing dataset.

RESULTS

At a 90% cutoff for the per-lesion score, CADx showed the highest specificity of 94.4% (95% confidence interval [CI], 91.3-96.6), with 59.8% (95% CI, 48.3-70.4) sensitivity and 87.3% (95% CI, 83.7-90.4) accuracy. The area under the characteristic curve was 85.1% (95% CI, 79.9-90.4) for CADx, 88.2% (95% CI, 83.7-92.8) for expert 1, 85.9% (95% CI, 80.9-90.9) for expert 2, 77.0% (95% CI, 71.5-82.4) for trainee 1 (vs CADx; P = .0076), and 66.2% (95% CI, 60.6-71.9) for trainee 2 (P < .0001). The function was also confirmed on 9 short videos.

CONCLUSIONS

A CADx system developed with endoscopic white-light images showed excellent per-lesion specificity and accuracy for T1b lesion diagnosis, equivalent to experts and superior to trainees. (Clinical trial registration number: UMIN000037053.).

[Liver metastasis from alpha-fetoprotein-producing gastric cancer 27 years postoperation:a case report]

A 75-year-old man with a history of distal gastrectomy for gastric cancer at 48 years of age underwent abdominal computed tomography, which revealed a left hepatic lobe tumor alongside direct gastric invasion. His blood test results revealed significant increase in serum alpha-fetoprotein (AFP) levels (32240.3ng/mL). A gastroscopy revealed that the histopathological findings of the biopsy specimens of the gastric invasion area were identical to those observed in the surgical specimens of gastric cancer, which was diagnosed 27 years earlier. The evaluation of the biopsy and surgical specimens revealed AFP positivity, which confirmed the diagnosis of the late recurrence of AFP-positive gastric cancer. Herein, we presented a rare clinical case of this malignancy. Additionally, a close, long-term postoperative follow-up is warranted in patients with AFP-producing gastric cancer.

A case of anisakiasis in the sigmoid colon

Colonic anisakiasis is rare because most cases of anisakiasis occur in the stomach. An accurate diagnosis is sometimes difficult because of the rarity and symptom nonspecificity. We should consider the possibility of colonic anisakiasis when examining patients who have a history of consuming raw fish.

[Diagnosis of an ileal neuroendocrine tumor based on lymph node metastases: a case report]

A 72-year-old man was diagnosed with tumors outside of the stomach and mesentery of the small intestine on abdominal computed tomography. Histopathological examination of an endoscopic ultrasound-guided fine-needle aspiration biopsy specimen confirmed the diagnosis of lymph node metastasis of a neuroendocrine tumor (NET). Gastroscopy, colonoscopy, small bowel capsule endoscopy, somatostatin receptor scintigraphy, and 18F-fluorodeoxyglucose positron emission tomography were performed. However, the primary lesion could not be diagnosed. The patient underwent surgery, and an ileal submucosal tumor, which was not identified preoperatively in addition to the aforementioned abdominal tumors, was detected. All tumors were diagnosed as NET, and the ileal tumor was considered the primary lesion. The patient has shown no recurrence postoperatively. The current study presents a case of an ileal NET with lymph node metastases in a patient in whom the primary lesion remained preoperatively undiagnosed.

Magnetoelastic interactions and magnetic damping in Co2Fe0.4Mn0.6Si and Co2FeGa0.5Ge0.5 Heusler alloys thin films for spintronic applications

Co₂Fe_0.4Mn_0.6Si (CFMS) and Co₂FeGa_0.5Ge_0.5 (CFGG) Heusler alloys are among the most promising thin film materials for spintronic devices due to a high spin polarization, low magnetic damping and giant/tunneling magnetoresistance ratios. Despite numerous investigations of Heusler alloys magnetic properties performed up to now, magnetoelastic effects in these materials remain not fully understood; due to quite rare studies of correlations between magnetoelastic and other magnetic properties, such as magnetic dissipation or magnetic anisotropy. In this research we have investigated epitaxial CFMS and CFGG Heusler alloys thin films of thickness in the range of 15-50 nm. We have determined the magnetoelastic tensor components and magnetic damping parameters as a function of the magnetic layer thickness. Magnetic damping measurements revealed the existence of non-Gilbert dissipation related contributions, including two-magnon scattering and spin pumping phenomena. Magnetoelastic constant B₁₁ values and the effective magnetic damping parameter α_eff values were found to be in the range of - 6 to 30 × 10⁶ erg/cm³ and between 1 and 12 × 10^-3, respectively. The values of saturation magnetostriction λ_S for CFMS Heusler alloy thin films were also obtained using the strain modulated ferromagnetic resonance technique. The correlation between α_eff and B₁₁, depending on magnetic layer thickness was determined based on the performed investigations of the above mentioned magnetic properties.

Polarization control with an X-ray phase retarder for high-time-resolution pump-probe experiments at SACLA

Control of the polarization of an X-ray free-electron laser (XFEL) has been performed using an X-ray phase retarder (XPR) in combination with an arrival timing diagnostic on BL3 of the SPring-8 Angstrom Compact free-electron LAser (SACLA). To combine with the timing diagnostic, a pink beam was incident on the XPR crystal and then monochromated in the vicinity of samples. A high degree of circular polarization of ∼97% was obtained experimentally at 11.567 keV, which agreed with calculations based on the dynamical theory of X-ray diffraction. This system enables pump-probe experiments to be operated using circular polarization with a time resolution of 40 fs to investigate ultrafast magnetic phenomena.

Human infection by acanthocephalan parasites belonging to the genus Corynosoma found from small bowel endoscopy

A 73-year-old man with a suspected ileus in January 2013 and subsequently suffered melena in February 2014 was endoscopically examined. As a result of the examinations, unidentified species of Corynosoma sp. and Corynosoma villosum were recovered from the small intestine, further endoscopic diagnosis suggested relevance between abdominal pain and the present infections in the small intestine. The recovered worms were composed of gravid females with developed eggs, suggesting that these parasites can survive for a long time in the intestine after infection. In this case, the short interval between infections appears to be due to the individual's eating habits which consist of regularly consuming uncooked seafood.

Laparoscopic-endoscopic cooperative surgery is a safe and effective treatment for superficial nonampullary duodenal tumors

The use of endoscopic submucosal dissection (ESD) for duodenal neoplasms has increased in recent years, but delayed perforation and bleeding are also known to frequently occur. We present two cases in which duodenal adenoma was successfully treated with laparoscopic-endoscopic cooperative surgery. ESD was combined with laparoscopic seromuscular sutures. The lesions in both cases were located in the second portion of the duodenum. The patients requested resection of the lesion, and we performed laparoscopic-endoscopic cooperative surgery. After the laparoscopic surgeon mobilized the duodenum, the endoscopic surgeon performed ESD for the duodenal tumor without perforation. The laparoscopic surgeon sutured the duodenal wall in the seromuscular layer to strengthen the ulcer bed after ESD. Histopathological studies confirmed that the surgical margins were tumor-free in both cases. The patients were discharged with no complications. This unique laparoscopic-endoscopic cooperative procedure is a safe and effective method for resecting superficial nonampullary duodenal tumors.

[A case of advanced primary colorectal carcinoma accompanied by liver metastasis in which ileus developed due to marked fibrosis with cicatricial formation in primary colorectal cancer treated by chemotherapy including bevacizumab]

A 64-year-old woman was introduced to our hospital with liver tumors. Our examination revealed that she had advanced colon carcinoma with multiple liver metastasis. Without symptoms from the primary cancer, she underwent chemotherapy of avastin FOLFOX. After 2 courses of chemotherapy, she suffered ileus and underwent operation. The resected specimen showed marked tumor necrosis and fibrosis, but few tumor cells remained in the primary lesion. We think this was a rare case of suffered ileus because of marked response of chemotherapy in primary colon carcinoma.

Abstract 1065: Regulation of autophagy and MAPK signaling by glutathione S-transferase-π in KRAS mutated cancer cells

Background: Mutated KRAS (mKRAS) is the most commonly found oncogene which may play a role in carcinogenesis at relatively early stage. Although Raf-1/MEK/ERK pathway has been well characterized as a proliferative signal at downstream of mKRAS, other signals related to senescence or apoptosis were also found at downstream of mKRAS and thus mKRAS function is still needed to be explored at a molecular level. We have hitherto disclosed a close correlation of GST-π expression and mKRAS in cancer tissues, induction of GST-π expression by KRAS transfection (Gastroenterology121:865-874, 2001) and significant reduction of mKRAS positive colon polyps in GST-π KO mice (unpublished observation), suggesting some cooperative function of GST-π for mKRAS.

Objective: In the present study, we attempted to clarify the molecular mechanisms of the cooperative function of GST-π for mKRAS activity in tumor cells.

Results: We first intended to confirm the correlation between GST-π expression and KRAS mutation in various human cancer cell lines by Western blotting. Those cells with no mKRAS (HepG2, HeLa, MCF7) were negative for GST-π expression while mKRAS-expressing cells (PANC-1, A549, M7609) were positive for GST-π. We then using M7609 cells, examined the effect of GST-π siRNA on their growth and found a significant impairment of cell proliferation. When GST-π KD M7609 cells were examined under electron microscopy, 40% of cells showed intracytoplasmic vesicles. The vesicles were positive for LC3 punctate signal by immunofluorescent staining and showed a characteristic feature of autophagosome, an organelle enclosed by a double lipid bilayer, by electron microscopy. In these cells, phosphorylation of Akt and EGFR was substantially reduced. Since interaction of GST-π with EGFR has been reported, it is plausible that this interaction positively regulates EGFR/class I PI3K/Akt/mTOR signal which in turn inhibits autophagy formation. Another mKRAS related signal: Raf-1/MEK/ERK was also explored in its relation to GST-π function. In M7609 KD cells, both Raf-1 protein and p-Raf-1 (S338), active form of Raf-1, were significantly reduced and phosphorylation of S621 residue which is known to play a crucial role in prevention of ubiquitination of Raf-1 protein was suppressed. In these cells, phosphorylation of downstream kinases of MEK and ERK were also reduced though their total protein levels were unchanged. When the cells were treated with proteasome inhibitor (MG132), recovery of Raf-1 and p-Raf-1 protein was observed. In parental M7609 cells, GST-π was found to be preferentially bound to p-Raf-1 on co-immunoprecipitation analysis, indicating that GST-π forms complex with Raf-1to prevent the Raf-1 from proteasomal degradation.

Conclusion: GST-π, on one hand prevents the cancer cells from autophagy formation and on the other hand, stimulates Raf-1/MEK/ERK signal by stabilizing Raf-1 protein in mKRAS cells.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 1065. doi:10.1158/1538-7445.AM2011-1065

Exacerbation of bloody diarrhea as a side effect of mesalamine treatment of active ulcerative colitis

Mesalamine has been used as the first-line therapy for the treatment of ulcerative colitis (UC) because of its efficacy and fewer side effects. However, earlier study showed that mesalamine occasionally causes diarrhea. We are presenting a patient with active UC in whom bloody diarrhea accompanied by abdominal pain and fever occurred and the symptoms were aggravated after administration of mesalamine. In order to clarify the reason of symptoms aggravation, drug lymphocyte stimulation test and rechallenge trial with mesalamine were performed. The results indicated the possibility that aggravation was related to allergic reaction and was dose-dependent. Furthermore, we examined colonoscopic views but there was no remarkable change in before and after rechallenge trial. Based on the above result, the patient was diagnosed with mesalamine intolerance. In order to differentiate whether the exacerbation of bloody diarrhea is due to the side effects of the mesalamine or a true relapse of UC, taking careful history before and after increasing mesalamine dosage as well as being aware of side effects of mesalamine are required. Clinicians should be aware of diarrhea as a side effect of mesalamine particularly after onset of mesalamine formulation, change in mesalamine formulation, or change in mesalamine dose.

Evolution of Nanoscale Ferromagnetic Particles in Co-Cr and Cr-Fe Alloys Observed by Atom Probe Field Ion Microscopy

With appropriate processing conditions, nanoscale ferromagnetic particles precipitate from nonmagnetic matrix phase in the Co-Cr and Cr-Fe systems. In these heterogeneous alloys, unique magnetic properties are observed. In order to correlate such magnetic properties with the microstructures, we have employed an atom probe field ion microscope (APFIM) and a three dimensional atom probe (3DAP). In the Co-22Cr thin film sputter-deposited at elevated temperatures (~500 K), both APFIM and 3DAP data convincingly showed that the film was composed of lamellae-like ferromagnetic and paramagnetic phases of approximately 8 nm in thickness. On the other hand, it was shown that the films sputter-deposited at ambient temperature was composed of s-Co single phase without significant compositional heterogeneity. Based on these observations, we conclude that phase separation progresses during the growth of the film on a heated substrate. In the Cr-Fe alloy, large negative MR was observed in the as-quenched alloy at liquid helium temperature. However, the MR behavior changes as the phase decomposition progresses by annealing. The change in the MR behavior observed in this alloy with various heat treatment conditions will be discussed based on the microstructural characterization results by APFIM and 3DAP.

Surface-assisted spin Hall effect in Au films with Pt impurities

We show, both experimentally and theoretically, a novel route to obtain giant room temperature spin-Hall effect due to surface-assisted skew scattering. In the experiment, we report the spin-Hall effect in Pt-doped Au films with different thicknesses t(N). The giant spin-Hall angle γ(S)=0.12±0.04 is obtained for t(N)=10 nm at room temperature, while it is much smaller for the t(N)=20 nm sample. Combined ab initio and quantum Monte Carlo calculations for the skew scattering due to a Pt impurity show γ(S)≅0.1 on the Au (111) surface, while it is small in bulk Au. The quantum Monte Carlo results show that the spin-orbit interaction of the Pt impurity on the Au (111) surface is enhanced, because the Pt 5d levels are lifted to the Fermi level due to the valence fluctuation. In addition, there are two spin-orbit interaction channels on the Au (111) surface, while only one in bulk Au.

[A long term survivor of advanced gastric cancer treated with multi-drug combination chemotherapy]

We report a case of 70-year-old man who was admitted to our hospital due to hematemesis in June 2004. He was diagnosed by gastroscopy as having a type III moderately-poorly differentiated adenocarcinoma. A computed tomography (CT) scan revealed multiple lymph nodes swelling (#13, #16), finally he was diagnosed with gastric cancer stage IV (cT3, cN3, cM1). He was treated with S-1, but lymph nodes swelling increased in size, and then in March 2005, the treatment was changed to a second-line chemotherapy consisting of CPT-11 and CDDP. Abdominal CT scan showed a remarkable reduction of #16b1 lymph node, and the second-line chemotherapy was continued until 23 courses. But in April 2007, gastroscopy revealed the enlargement of gastric lesion. He was treated by third-line chemotherapy consisting of paclitaxel and doxifluoridine. This therapy was effective and continued until 7 courses. However, the treatment gradually became resistant and he died in May 2008, which was 4 years since the initial diagnosis.

Efficacy of iron-fortified rice in reducing anemia among schoolchildren in the Philippines

BACKGROUND

Iron deficiency anemia (IDA) in the Philippines is a serious public health problem. Fortifying rice offers a great opportunity to control IDA. However, information on other types of fortificants that can be used is scarce.

OBJECTIVE

To compare the effects of two types of iron fortificants in rice in improving the hematological status of schoolchildren.

DESIGN

180 randomly selected 6-to 9-year-old anemic children were randomly allocated to three groups in a double-blinded manner: One group received iron-enriched rice (IER) with extruded iron premix rice (IPR) using ferrous sulfate as fortificant (ExFeSO4); the second group received IER with extruded IPR using micronized dispersible ferric pyrophosphate (ExFeP80); and the third group received non-fortified rice (Control). These were administered daily for 5 days a week for 6 months. Blood samples were collected at baseline after 3 and 6 months.

RESULTS

At baseline, one child in the ExFeP80 group was suffering from IDA; at 3 months, no IDA was found in any groups; while at 6 months, one child in the ExFeP80 developed IDA. The baseline prevalence of anemia in all groups, which was 100%, was significantly reduced to 51%, 54%, and 63% in the ExFeSO4, ExFeP80 and Control groups respectively. After 6 months, further significant reductions were observed in the ExFeSO4 (38%) and ExFeP80 (33%) but remained at 63% in the Control group. Greater, significant increases were also observed in plasma ferritin in the fortified groups than in the Control group from baseline to 6 months. The predictors of change in hemoglobin (Hb) and plasma ferritin were group allocation and basal values.

CONCLUSION

The consumption of rice fortified with FeP80 using extrusion technology has similar effects as that of FeSO4 in reducing the prevalence of IDA among schoolchildren.

A Phase I trial of arterial infusion chemotherapy with gemcitabine and 5-fluorouracil for unresectable advanced pancreatic cancer after vascular supply distribution via superselective embolization

BACKGROUND

We previously reported that arterial infusion chemotherapy improved the response rate and survival of the patients with pancreatic cancer at advanced stages in an open trial. We conducted a Phase I trial of arterial infusion chemotherapy with gemcitabine and 5-fluorouracil for advanced pancreatic cancer after vascular supply distribution via superselective embolization.

METHODS

Patients were treated after arterial embolization for hemodynamic change to restrict the blood flow into the pancreas (mainly to the great pancreatic artery and the caudal pancreatic artery). Arterial infusion chemotherapy consisted of gemcitabine in doses that were increased from 600 to 1000 mg/m(2) in subsequent cohorts on Day 1 plus continuous infusion of 5-fluorouracil 300 mg/m(2)/day on Days 1-5 every 2 weeks. Result Twelve patients were enrolled. The maximum tolerated dose of gemcitabine was determined to be Level 3 (1000 mg/m(2)). Only very mild hematological and non-hematological toxicities were noted. The overall response rate was 33.3%. The median survival time was 22.7 (95% CI; 9.5-24.5) months and the 1- and 2-year overall survival rates were 83.3 and 25.0%, respectively.

CONCLUSION

Arterial infusion chemotherapy using 1000 mg/m(2) gemcitabine on Day 1 and 300 mg/m(2)/day 5-fluorouracil on Days 1-5 every 2 weeks warrants a Phase II study.

[A case of intraductal papillary mucinous neoplasm with internal pancreatic fistula causing left ureteral obstruction]

A 75-year-old man had been admitted to another hospital because of left abdominal pain, and was given a diagnosis of left hydronephrosis and acute pancreatitis. After a JJ stent insertion and medication, he was transferred to our hospital for further examinations. US and EUS revealed a chronic pancreatitis-like pattern and multicystic lesion in the pancreas head and body. At that time enhanced CT findings showed an extrapancreatic low density area to be inflammatory change, extending from the pancreas body to the left crus of the diaphragm and posteriorly the spreading from the left crus of the diaphragm via the left urinary duct into the left iliopsoas muscle, in which MRI revealed partial high intensity. ERCP and MRCP showed focal irregular narrowing of the pancreatic duct of unknown cause, and we decided that an internal pancreatic fistula due to pancreatitis had induced left ureteral obstruction, caused by a protein plug or alcohol. Follow-up 6 months later showed that extrapancreatic spreading of the low density area had markedly regressed without any change in the ureteral obstruction.

Pressure-induced enhancement of giant magnetoresistance due to crossover of interlayer exchange coupling in Fe/Cr multilayers

We report the first observation of a large pressure-induced enhancement of giant magnetoresistance (GMR) in magnetic multilayers (MML). In Fe/Cr MMLs with the Cr layer thickness of approximately 30 A, a crossover from biquadratic to bilinear interlayer exchange coupling (IEC) was observed by applying pressure, and simultaneously the GMR under high pressure (>2 GPa) was enhanced to be twice as large as that at ambient pressure. The enhanced GMR is attributed to the suppression of the biquadratic IEC by applying pressure, and the electrical resistivity in parallel alignment of magnetization also showed a crossover behavior, suggesting an electronic origin for the observed pressure effects.

Aberrant crypt foci: detection, gene abnormalities, and clinical usefulness

Human aberrant crypt foci (ACF) were first identified as lesions consisting of large thick crypts in colonic mucosa of surgical specimens after staining with methylene blue. Previously we succeeded in identifying ACF by using magnifying endoscopy and analyzed the number, size, and dysplastic features of ACF in normal controls and patients with adenoma or cancer patients. On the basis of these analyses, we strongly suggested that ACF, particularly dysplastic ACF, are precursor lesions of the adenoma-carcinoma sequence in humans. In most sporadic ACF, K-ras mutations were positive, but APC mutations were negative irrespective of nondysplastic or dysplastic features. Conversely, in most ACF from familial adenomatous polyposis patients, APC mutations were positive but K-ras mutations were negative. These results may suggest that the molecular mechanism of sporadic colon carcinogenesis is not necessarily the same as that of familial adenomatous polyposis. It was shown that ACF acquired resistance to apoptosis induced by bile salts, whereas normal colonic epithelial cells are turning over consistently by apoptosis. This apoptosis resistance was closely associated with glutathione S-transferase P1-1 expression. One of the most important clinical applications of ACF observation with magnifying endoscopy is its use as a target lesion for chemoprevention. Because ACF are tiny lesions, they should be eradicated during a short time by administration of chemopreventive agents. In fact, we performed an open chemopreventive trial of sulindac and found that the number of ACF was reduced markedly in 2 months. We currently are proceeding with a randomized double-blind trial targeting ACF.

Chemoprevention of colorectal cancer

Colorectal cancer is a disease with a high mortality rate and it has been increasing in prevalence worldwide. Chemoprevention, as well as primary and secondary prevention, for colorectal cancer have attracted much attention. Many chemopreventive trials have been performed, and several agents, including nonsteroidal antiinflammatory drugs, such as aspirin and sulindac, cyclooxygenase-2 selective inhibitors, such as celecoxib, vitamin D, folate, and calcium, have been shown to have some effect. In these chemopreventive trials, the targeted lesions used for evaluation were mainly polyps. However, the chemopreventive effects of some agents on polyps may require several years to evaluate. Further, larger polyps may not be susceptible to chemopreventive agents. Aberrant crypt foci (ACF) are tiny lesions at the earliest stage of colorectal carcinogenesis, which consist of large, thick crypts identified by dense, methylene blue staining. We succeeded in identifying human ACF in situ using magnifying endoscopy and found that the number of ACF, particularly dysplastic ACF, increased significantly from normal subjects to adenoma patients and then to cancer patients. We also found that the number, size, and dysplastic features of ACF are significantly correlated with the number of adenomas in adenoma patients. Thus, it was surmised that ACF are precursor lesions of the adenoma-carcinoma sequence in humans and that ACF may be the most appropriate lesions as targets for chemoprevention. We have shown that the number of ACF was significantly reduced in patients treated with sulindac. We are currently proceeding with a randomized, double-blind, chemopreventive trial targeting ACF.

[A case of metastatic liver tumor from colorectal carcinoma--continued arterial infusion chemotherapy through a microcatheter located in replaced right hepatic artery]

The patient was a 78-year-old male with a history of colon cancer. After surgical resection of colon cancer, he suffered a multiple liver metastasis. We treated him by arterial infusion chemotherapy with the catheter edge embedded at the common hepatic artery. For a long period, the lesions were defined as partial response on WHO-criteria, but a wide area of the common hepatic artery was shrunk. After changing the treatment to systemic intravenous chemotherapy, the metastatic lesions began to enlarge. Then, we somehow were able to put a microcatheter into the replaced right hepatic artery (rRHA), and could restart arterial infusion chemotherapy. We continued this procedure for over a year without any complication.

Glutathione-S-transferase P1-1 protects aberrant crypt foci from apoptosis induced by deoxycholic acid

BACKGROUND & AIMS

Aberrant crypt foci, precursors of colonic adenoma, are frequently positive for glutathione-S-transferase P1-1. Because deoxycholic acid is an apoptosis-inducing xenobiotic in the colon, we examined the possibility that aberrant crypt foci, through the cytoprotecting function of glutathione-S-transferase P1-1, resist deoxycholic acid-induced apoptosis, thereby surviving to become adenomas and subsequently cancer.

METHODS

Glutathione-S-transferase P1-1 or cyclooxygenase-2 expression and the percentage of apoptotic cells in aberrant crypt foci were examined by immunohistochemistry and by terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick-end labeling, respectively. Glutathione-S-transferase P1-1 was transfected into colon cancer cells (M7609) and human lung fibroblasts, and deoxycholic acid-induced apoptosis was evaluated by a dye-uptake assay and flow cytometry. Binding of deoxycholic acid to glutathione-S-transferase P1-1 was analyzed by circular dichroism and immunoprecipitation. Caspase activities were determined by colorimetric protease assay, and sulindac binding to glutathione-S-transferase P1-1 was determined by inhibition assay of glutathione-S-transferase P1-1 activity.

RESULTS

Aberrant crypt foci showed positive immunostaining for glutathione-S-transferase P1-1 but negative staining for cyclooxygenase-2. The percentage of apoptotic cells in aberrant crypt foci was significantly lower than in healthy epithelium, and the difference became more apparent with deoxycholic acid treatment. The impaired sensitivity of aberrant crypt foci to deoxycholic acid was restored by the glutathione-S-transferase P1-1-specific inhibitor gamma-glutamyl-S-(benzyl)cysteinyl-R-phenylglycine diethylester. By transfection of glutathione-S-transferase P1-1, M7609 cells became more resistant to deoxycholic acid-induced apoptosis than mock transfectants. Direct binding of glutathione-S-transferase P1-1 to deoxycholic acid was proven by circular dichroism and by immunoprecipitation. The aberrant crypt foci in adenoma patients treated with sulindac, which was shown to bind to glutathione-S-transferase P1-1, underwent apoptosis in 4 days and mostly regressed in 2-3 months.

CONCLUSIONS

Glutathione-S-transferase P1-1 protects aberrant crypt foci from deoxycholic acid-induced apoptosis and may play a pivotal role in early colon carcinogenesis.

Advanced pancreatic carcinoma showing a complete response to arterial infusion chemotherapy

We report a patient with advanced carcinoma of the pancreatic body and tail with multiple liver metastases who showed a complete response to hepatic and splenic arterial infusion chemotherapy (HSAIC) with gemcitabine and 5-fluorouracil, following transcatheter peripancreatic arterial embolization (TPPAE) and partial splenic embolization (PSE). Nonresectable advanced pancreatic carcinoma tends to have a low response to medical treatment, with the median survival time being 6 months or less for stage IV cases. We disclose herein that the median survival time of patients receiving HSAIC after TPPAE is more than three times longer than the survival time attained with conventional treatments. However, in patients with advanced carcinoma of the pancreatic tail, for which TTPAE is not applicable, survival times remain low. Thus, in the patient described here, we also performed embolization of the left gastric and short gastric arteries as well as PSE to increase the flow within the great pancreatic and caudal pancreatic arteries via the splenic artery, and gemcitabine and 5-fluorouracil were administered via the splenic artery. As a result of these procedures, marked reduction in the advanced carcinoma of the pancreatic body and tail and of liver metastases was attained.

Clinical Usefulness of Doxazosin in Patients with Type 2 Diabetes Complicated by Hypertension: Effects on Glucose and Lipid Metabolism

This uncontrolled study investigated the effects of using the α1-blocker doxazosin (2 mg or 4 mg daily for 3 months) to treat 21 hypertensive patients with type 2 diabetes, including eight obese individuals (body mass index [BMI] > 25.0 kg/m2). A significant reduction in systolic and diastolic blood pressure, beginning after 1 month of treatment, was seen. There was no significant change in BMI. Although there was no obvious improvement in glucose metabolism, doxazosin treatment noticeably reduced insulin resistance and significantly lowered triglyceride and free fatty acid levels. No significant changes were found in total cholesterol, high-or low-density lipoprotein-cholesterol, atherosclerotic index, or small or large subfractions of low-density lipoprotein-cholesterol. None of the patients showed any adverse effects. The beneficial effects of doxazosin on blood pressure and lipid and glucose metabolism shown in this study suggest that this drug is clinically useful as an anti-hypertensive agent for patients with diabetes.

[Three cases of multiple liver metastases of carcinoid tumor responding to hepatic arterial infusion chemotherapy using degradable starch microspheres]

We describe three patients with multiple liver metastases of carcinoid tumor who received hepatic arterial infusion chemotherapy using degradable starch microspheres (DSM). A partial response was obtained in all cases, and no side effects were observed. We believe that this chemotherapy was an effective treatment for unresectable liver metastases of carcinoid tumor.

Relationship between plasma soluble thrombomodulin levels and insulin resistance syndrome in type 2 diabetes: a comparison with von Willebrand factor

Endothelial dysfunction plays a pivotal role in the initial stage of atherosclerosis. Insulin resistance is associated with accelerated atherosclerosis, especially coronary heart disease. To elucidate the relationship between endothelial dysfunction and insulin resistance or insulin resistance syndrome in patients with type 2 diabetes, we investigated the correlation between plasma soluble thrombomodulin (TM) and von Willebrand factor (vWF), measures of endothelial dysfunction, and the degree of insulin resistance evaluated by homeostasis assessment models of insulin resistance (HOMA-IR), or variables of insulin resistance syndrome. We studied 53 patients with type 2 diabetes, 23 treated with diet alone and 30 treated with sulfonylureas, who had normal renal function. The plasma soluble TM concentrations were highly correlated with HOMA-IR (r=0.64, p<0.0001), the plasma insulin (r=0.72, p<0.0001), the systolic blood pressure (r=0.45, p=0.0005), and the plasma fibrinogen (r=0.43, p=0.0018), while they were inversely correlated with the serum HDL cholesterol concentrations (r=-0.27, p=0.0344). The plasma vWF concentrations were positively correlated with HOMA-IR (r=0.35, p=0.0151) and the plasma fibrinogen (r=0.32, p=0.0203), but not with the plasma insulin, the systolic blood pressure or the HDL cholesterol concentrations. Furthermore, plasma TM, but not vWF, was positively correlated with total number of variables of insulin resistance syndrome (r=0.45, p=0.0005). These results indicate that endothelial dysfunction may be associated with the pathogenesis of insulin resistance syndrome as well as insulin resistance, and that the plasma TM might reflect endothelial damage better than the plasma vWF in the state of insulin resistance in patients with type 2 diabetes.

Estrogen markedly increases LDL-receptor activity in hypercholesterolemic patients

We investigated the change in low-density lipoprotein receptor activity following the administration of estrogen to patients with hypercholesterolemia (HC). Studies were conducted in 16 patients with HC (total cholesterol (TC)>220 mg/dL) and 133 healthy control subjects. LDL-R activity was measured by fluorocytometry. Three of sixteen patients with HC showed low LDL-R activity below 80% together with extremely high serum levels of TC and LDL cholesterol (LDL-C). LDL-R activity showed an inverse correlation with serum levels of TC and LDL-C (p<0.05, respectively). Two women with initially low LDL-R activity who showed a marked increase in LDL-R activity exhibited a normalized activity at four and eight weeks after estriol administration, proportional to the reduction in serum levels of TC and LDL-C. One man with an initially extremely low LDL-R activity showed no abnormality at the sites of exons 7, 14, 17 and intron 12 by the PCR-DGGE method, which are common sites for point-mutations of LDL-R among Japanese patients with HC. Estrogen reduced serum levels of TC and LDL-C in patients with HC, at least in part, via an increase in the LDL-R activity of patients with HC and an initially low LDL-R activity.

Changes in skin blood flow in type 2 diabetes induced by prostacyclin: association with ankle brachial index and plasma thrombomodulin levels

In a previous study, we reported that beraprost sodium (BPS), a stable prostaglandin I(2) (PGI(2)) analog, increases skin blood flow in the feet of both control subjects and patients with type 2 diabetes, and that the flow increase induced by BPS is lower in diabetic patients than in controls. The present study was undertaken to clarify factors associated with smaller increases in skin blood flow in the feet of patients with type 2 diabetes after the administration of BPS, and to investigate the relationship between microalbuminuria and the changes in skin blood flow induced by the PGI(2) analog. We studied 61 patients with type 2 diabetes: 10 received placebo (control) and 51 (31 with normoalbuminuria and 20 with microalbuminuria) received BPS. Using laser Doppler flowmetry, we measured the skin blood flow at the pulp of the right big toe before and 90 minutes after administration of 40 microg BPS, and calculated the change in blood flow, i.e., delta flux (peak flux at 90 minutes - basal flux at 0 minutes). Plasma concentrations of soluble thrombomodulin (TM) were determined using an enzyme immunoassay (EIA) sandwich method. BPS significantly increased skin blood flow in the treatment group compared with the placebo group (P <.01). The delta flux was positively correlated with the value of the ankle brachial index (ABI) (r =.41, P <.0038) and was negatively correlated with plasma TM levels (r = -.53, P <.0001). By multiple regression analysis both the ABI value and the plasma TM level retained a significant influence on delta flux. Furthermore, both the delta flux and the ABI value in patients with microalbuminuria were lower than in patients with normoalbuminuria (P <.05). The results suggest that BPS increases the skin blood flow of the toe of patients with type 2 diabetes and that the increased flow is independently influenced by the value of the ABI and the plasma TM levels; in addition, microalbuminuria is associated with the impairment of vasodilation in the feet in response to BPS.

Insulin resistance and changes in the blood coagulation-fibrinolysis system after a glucose clamp technique in patients with type 2 diabetes mellitus

We investigated the relationship between changes in insulin resistance and blood coagulation-fibrinolysis following institution of a glucose clamp (GC) in patients with type 2 diabetes mellitus. We studied 35 type 2 diabetic patients (19 males and 16 females, mean age at 58.3 +/- 11.9 years) and 10 healthy subjects. The hyperinsulinemic euglycemic GC technique was performed using on artificial pancreas. The degree of insulin resistance was determined from the glucose infusion rate (GIR) calculated from the GC technique. The GIR in type 2 diabetic patients was markedly reduced compared to that in healthy subjects. The GIR was significantly and negatively correlated with the body mass index and the serum concentrations of the fasting immunoreactive insulin (FIRI). The plasma concentrations of thrombomodulin (TM) and tissue plasminogen activator (tPA) in the diabetic patients were significantly higher than those in the healthy subjects. The plasma concentrations of plasminogen activator inhibitor 1 in the diabetic patients tended toward higher than those in the healthy subjects. The elevated plasma concentrations of TM and tPA in diabetes were significantly lowered following a GC technique. Patients with advanced nephropathy had significant higher concentrations of TM and tPA compared to healthy subjects. We concluded that diabetic patients have abnormalities in the blood coagulation-fibrinolytic system that can be improved by the GC technique.

Detection and measurement of urinary 2-hydroxyestradiol 17-sulfate, a potential placental antioxidant during pregnancy

BACKGROUND

Preeclampsia is associated with a quantitative imbalance between lipid peroxide and an antioxidant coproduced in the placenta. To investigate our hypothesis that 2-hydroxyestradiol 17-sulfate (2-OH-ES) is the placental antioxidant during pregnancy, we developed an assay for 2-OH-ES in urine and studied samples from women with and without preeclampsia.

METHODS

The detection and measurement of 2-OH-ES in the urine of pregnant women were performed by RIA using highly specific antiserum to 2-OH-ES. To confirm the reliability of the RIA method, the same samples were analyzed by HPLC using an electrochemical detector.

RESULTS

Urinary 2-OH-ES values obtained by RIA showed a close relationship to those obtained by HPLC (y = 1.1x - 0.01; r = 0.96). The urinary 2-OH-ES concentrations during the first, second, and third trimesters were 2. 0 +/- 0.6 (mean +/- SE, n = 13), 5.3 +/- 1.3 (n = 21), and 15.3 +/- 2.0 microg/mg creatinine (n = 54), respectively, and <0.15 microg/mg creatinine (n = 10) at 2-24 h after delivery. The concentrations in preeclamptic women during the third trimester were significantly lower, 3.9 +/- 1.9 microg/mg creatinine (mean +/- SE, n = 12).

CONCLUSIONS

RIA can be used to measure urinary 2-OH-ES during pregnancy. The increase in urinary 2-OH-ES during gestation, its decrease after delivery, and the lower values in preeclampsia are consistent with a role of 2-OH-ES as a placental antioxidant.

CYP2C9 Ile359 and Leu359 variants: enzyme kinetic study with seven substrates

To assess the effects of Ile359 to Leu359 change on CYP2C9-mediated metabolism, we performed site-directed mutagenesis and cDNA expression in yeast for CYP2C9 and examined in detail the kinetics of seven metabolic reactions by wild-type CYP2C9 (Ile359) and its Leu359 variant. For the metabolism of all the substrates studied, the Leu359 variant exhibited smaller Vmax/Km values than did the wild-type. The differences in the Vmax/Km values between the wild-type and the Leu359 variant varied from 3.4-fold to 26.9-fold. The Leu359 variant had higher Km values than did the wild-type for all the reactions studied. Among the seven reactions studied, the greatest difference in the Vmax values between the wild-type and the Leu359 variant was for piroxicam 5'-hydroxylation (408 versus 19 pmol/min/nmol P450), whereas there were no differences in the Vmax values between the wild-type and the Leu359 variant for diclofenac 4'-hydroxylation and tolbutamide methylhydroxylation. These results indicate that the Ile359 to Leu359 change significantly decreases the catalytic activity of all the CYP2C9-mediated metabolisms studied, whereas the extent of the reduction in activity and changes of the kinetic parameters varies between substrates. Moreover, the amino acid substitution decreased the enantiomeric excess in the formation of 5-(4-hydroxyphenyl)-5-phenylhydantoin from phenytoin.

Thyroid hormone modulates insulin-like growth factor-I(IGF-I) and IGF-binding protein-3, without mediation by growth hormone, in patients with autoimmune thyroid diseases

The expression and synthesis of insulin-like growth factor-1 (IGF-I) and IGF-binding protein-3 (IGFBP-3) are regulated by various hormones and nutritional conditions. We evaluated the effects of thyroid hormones on serum levels of IGF-I and IGFBP-3 levels in patients with autoimmune thyroid diseases including 54 patients with Graves' disease and 17 patients with Hashimoto's thyroiditis, and in 32 healthy age-matched control subjects. Patients were subdivided into hyperthyroid, euthyroid and hypothyroid groups that were untreated, or were treated with methylmercaptoimidazole (MMI) or L-thyroxine (L-T4). Serum levels of growth hormone (GH), IGF-I and IGFBP-3 were determined by radioimmunoassay. Serum GH levels did not differ significantly between the hyperthyroid and the age-matched euthyroid patients with Graves' disease. The serum levels of IGF-I and IGFBP-3 showed a significant positive correlation in the patients (R=0.616, P<0.001). The levels of both IGF-I and IFGBP-3 were significantly higher in the hyperthyroid patients with Graves' disease or in those with Hashimoto's thyroiditis induced by excess L-T4 administration than in control subjects. Patients with hypothyroid Graves' disease induced by the excess administration of MMI showed significantly lower IGFBP-3 levels as compared to those in healthy controls (P<0.05). Levels of IGFBP-3, but not IGF-I levels, showed a significant positive correlation with the levels of free T4 and free T3. In Graves' disease, levels of TPOAb, but not of TRAb, showed a significant positive correlation with IGFBP-3. We conclude that in patients with autoimmune thyroid diseases, thyroid hormone modulates the synthesis and/or the secretion of IGF-I and IGFBP-3, and this function is not mediated by GH.