Katsutoshi Murase

Malignant schwannoma of the esophagus with lymph node metastasis: literature review of schwannoma of the esophagus

An extremely rare case of malignant schwannoma of the esophagus with lymph node metastasis is reported. A 49-year-old woman was found to have an abnormal shadow on a chest X-ray film taken during an annual checkup. Upper gastrointestinal series showed extrinsic pressure on the middle thoracic esophagus, without a mucosal lesion. An exploratory operation was performed, with a tentative diagnosis of esophageal leiomyoma. The tumor was enucleated with part of the esophageal mucosa, and a few enlarged lymph nodes around the tumor were dissected. The resected tumor was an elastic firm mass, measuring 8.2 x 5.8 x 3.7 cm, and had a smooth surface. Histological examination of the tumor revealed the proliferation of spindle-shaped cells with chromatin-rich nuclei. The nuclei were variable in size and showed remarkable atypia. A paraesophageal lymph node had same findings as the main tumor. Immunohistochemically, the tumor cells were diffusely positive for S-100 protein and neuron-specific enolase. The pathological diagnosis of this tumor was malignant esophageal schwannoma with lymph node metastasis. Esophageal schwannoma is extremely rare. We reviewed the literature on 19 cases of esophageal schwannoma, including that in our patient. The majority of the tumors were benign. Only three cases of schwannoma were malignant, and this is the first reported case of malignant schwannoma with lymph node metastasis.

SYNTHETIC STUDIES ON SELECTIN LIGANDS/INHIBITORS : A SYSTEMATIC SYNTHESIS OF SULFATIDE AND ITS HIGHER CONGENERS CARRYING 2-(TETRADECYL)HEXADECYL GROUP AS A CERAMIDE SUBSTITUTE

Abstract A systematic synthesis of sulfatide (I) and novel sulfatide analogs (II-VI) carrying 2-(tetradecyl)hexadecyl group as a ceramide substitute is described. The 3-O-, 4-O- and 3,4-di-O-levulinoyl derivatives of galactopyranosyl trichloroacetimidates (1, 12, and 13) were coupled with (2S,3R,4E)-3-O-acetyl-2-octadecanamido-4-octadecene-1,3-diol or 2-(tetradecyl)hexadecan-1-ol. The resulting glycolipids (2, 4, 14, and 15) were each transformed, by selective removal of the levulinoyl group(s), and successive sulfation and de-O-acylation, into the 3-sulfates (I, II), 4-sulfate (III), and 3,4-disulfate (IV). The 6-sulfate (V) was prepared from 2-(tetradecyl)hexadecyl β-D-galactopyranoside (21) via the 6-O-t-butyldimethylsilyl derivative, while the 3′-sulfate of 2-(tetradecyl)hexadecyl β-D-lactoside (VI) was synthesized from 2-(trimethylsilyl)ethyl 3′-O-benzyl-β-D-lactoside (26). The structures of the sulfated glycolipids (I-VI) were characterized by ion-spray MS, MS/MS, and 1H NMR spectrometry. 1. Synthet...

In Vivo Imaging of Transplanted Islets Labeled with a Novel Cationic Nanoparticle

To monitor pancreatic islet transplantation efficiency, reliable noninvasive imaging methods, such as magnetic resonance imaging (MRI) are needed. Although an efficient uptake of MRI contrast agent is required for islet cell labeling, commercially-available magnetic nanoparticles are not efficiently transduced into cells. We herein report the in vivo detection of transplanted islets labeled with a novel cationic nanoparticle that allowed for noninvasive monitoring of islet grafts in diabetic mice in real time. The positively-charged nanoparticles were transduced into a β-cell line, MIN6 cells, and into isolated islets for 1 hr. MRI showed a marked decrease in the signal intensity on T1- and T2-weighted images at the implantation site of the labeled MIN 6 cells or islets in the left kidneys of mice. These data suggest that the novel positively-charged nanoparticle could be useful to detect and monitor islet engraftment, which would greatly aid in the clinical management of islet transplant patients.

Graft-preserving treatment for vascular graft infected with Staphylococcus aureus with antibiotic-releasing porous apatite ceramic in the rabbit.

OBJECTIVE This study was undertaken to investigate whether infection of a vascular graft with Staphylococcus aureus can be treated in situ by applying antibiotic-loaded porous apatite ceramic, in a rabbit model. METHODS Teicoplanin (TEIC) was loaded onto a beta-tricalcium phosphate (TCP) block, a type of porous apatite ceramic. The activity of TEIC released from the antibiotic-loaded TCP block was examined in vivo. A vascular graft was patched onto the abdominal aorta in 24 rabbits, and S aureus was applied directly on it. Seven days postoperatively, each rabbit underwent repeat laparotomy, and retroperitoneal abscess around the prosthetic vascular patch was debrided. Animals were divided into four groups of 6 rabbits each. In group 1 only debridement was carried out. In groups 2 and 3, solution containing 40 or 60 mg of TEIC, respectively, was applied to the prosthetic vascular patch. In group 4, an antibiotic-loaded TCP block (63 +/- 6.6 mg of TEIC) was placed around the graft. Three weeks after the second operation, the graft, the tissue around it, and arterial blood were collected and cultured. RESULTS TEIC activity was maintained for 28 days in vivo. In group 1, bacterial cultures of the prosthetic vascular graft and the tissue around it were positive in 5 animals and negative in 1 animal (infection rate, 83%). In both groups 2 and 3, cultures were positive in 3 animals and negative in 3 animals (infection rate, 50%). In group 4, cultures were negative in all animals (infection rate, 0%). Blood cultures were negative in all animals. Infection rate in group 4 was significantly lower than that in group 1 (P =.03), and was also lower than that in groups 2 and 3, but the difference was not significant. CONCLUSIONS Use of slow-release antibiotic loaded onto a TCP block, along with debridement, may control infection in vascular grafts in situ, averting the necessity to remove the graft.

Cell labeling with a novel contrast agent of magnetic resonance imaging.

Cell therapy is a proven and efficient method for treating multiple diseases. For both basic research and clinical practice, the development of noninvasive in vivo imaging methods is essential for monitoring the trafficking or homing of transplanted cells. One attractive approach for the effective imaging of transplanted cells is the efficient labeling of cells with a contrast agent. In this study, we developed a novel contrast agent of magnetic resonance imaging (MRI), TMADM-02. TMADM-02 was efficiently transduced into cells without toxicity. However, the aggregation of TMADM-02 was observed because of its low stability in culture medium. Therefore, TMADM-02 may have led to a false-positive test result. In future studies, we should verify not only the efficiency of labeling cells but also the stability of the contrast agent of MRI for clinical applications.

Novel Positive-Charged Nanoparticles for Efficient Magnetic Resonance Imaging of Islet Transplantation:

Significant graft loss immediately after islet transplantation occurs due to immunological and nonimmunological events. Magnetic resonance imaging (MRI) is an attractive potential tool for monitoring islet mass in vivo. Although an efficient uptake of MRI contrast agent is required for islet cell labeling, commercially available magnetic nanoparticles are not efficiently transduced into cells. In this study, we developed six kinds of novel magnetic iron oxide nanoparticles, which are electrically charged by cationic end-group substitution of dextran. Each of the nanoparticles consisted of a small monocrystalline, superparamagnetic iron oxide core that is stabilized by a cross-linked aminated dextran coating to improve stability. We also used three different commercially available nanoparticles for controls. The labeling efficiency of the novel nanoparticles was evaluated, and the feasibility of the imaging by MRI was assessed. The positive-charged nanoparticles were transduced into a β-cell line, MIN6 cells, but not three commercially available nanoparticles. MRI showed a marked decrease in signal intensity on T1- and T2-weighted images at the site of the labeled cells in vitro. These data suggest that novel positive-charged nanoparticles could be useful MRI contrast agents to monitor islet mass after transplantation.

Observation of Positively Charged Magnetic Nanoparticles Inside HepG2 Spheroids Using Electron Microscopy.

Magnetic resonance imaging (MRI) using magnetic nanoparticles has been used to diagnose vascular diseases as well as to monitor transplanted cells and tissues. In this study, we synthesized magnetic iron oxide nanoparticles (TMADM-03), electrically charged by the presence of a cationic end-group substitution of dextran, and observed these nanoparticles inside three-dimensional models of HepG2 spheroids, which mimic tissues. Patterned cell array glass disks were prepared to visualize the presence of TMADM-03 uptaken by HepG2 spheroids using transmission electron microscopy (TEM). The HepG2 cells (2 × 10(5) cells) were inoculated onto Cell-able™ 12-well plates. After 48 h of culture, the cells were incubated with 75 µg Fe/ml TMADM-03 in culture medium for 24 h. To investigate the cellular function of the HepG2 spheroids, the albumin secretion was evaluated by an ELISA. The albumin secretion after incubation for 24 h was reduced compared with the secretion prior to the addition of TMADM-03. TEM image samples were prepared in a planar direction or a vertical direction to the HepG2 spheroids on patterned cell array glass disks. The incorporation of TMADM-03 inside the HepG2 spheroids was confirmed. In addition, TMADM-03 could be observed in the deeper layers of the spheroids, and this was localized in the lysosomes. These data suggest that the novel magnetic iron oxide nanoparticles invade three-dimensional HepG2 spheroids.

Morphological changes of the anterior spinal artery during aortic cross-clamping and effect of prostaglandin E1 with perfusion

This investigation was designed to evaluate the morphological changes of anterior spinal artery (ASA) and its reaction to prostaglandinE1 (PGE1) during aortic cross-clamping. ASA during 30 min cross-clamping was observed with charge-coupled device (CCD) and ASA diameter (ASAD) was measured. Group A: Infrarenal aorta was cross-clamped. Group B: Infrarenal aorta was cross-clamped and aorta above the bifurcation was snared. The aortic segment between clamp and snare was perfused with blood. Group C: PGE1 of 100 ng/kg/min was added to perfusate of Group B. The aortic segmental pressures in group B and C were about 30% of the proximal systolic arterial pressure and were significantly higher than distal pressure of group A. After cross-clamping, ASAD decreased about 80% of before cross-clamping in group A. By segmental perfusion of which pressure was about 30% of proximal systolic arterial pressure, ASAD remained almost 90% in group B. By administration of PGE1, ASAD was significantly increased in group C. The changes of ASAD were significantly different between group A and C, and between group B and C.

Radical resection of a giant retroperitoneal calcifying fibrous tumor combined with right hepatectomy and reconstruction of the inferior vena cava and bilateral renal veins

BackgroundWe report a case of a giant retroperitoneal calcifying fibrous tumor (CFT) treated by radical tumor resection combined with right hepatectomy and reconstruction of the inferior vena cava (IVC) and bilateral renal veins. Only three case reports of CFT arising in the retroperitoneum have been reported until today.Case presentationIn a 19-year-old female patient, computed tomography (CT) images showed a well-demarcated expansile lesion around the IVC accompanied by focal calcification, whereas the IVC that was circumferentially surrounded by the lesion was dilated due to the desmoplastic reaction. On magnetic resonance imaging (MRI), the lesion demonstrated heterogeneous hypointensity on T2-weighted images. Delayed enhancement was observed on dynamic contrast-enhanced CT and MRI. 18F-Fluorodeoxyglucose (FDG) positron emission tomography (PET)/CT images showed increased FDG uptake [maximum standardized uptake values (SUVmax), early image 7.28; delayed image 7.40]. On operative examination, because the tumor adhered to the liver parenchyma, the right Glisson capsule, and the origin of bilateral renal veins, radical tumor resection combined with right hepatectomy and reconstruction of the IVC and bilateral renal veins was performed.ConclusionsRadical tumor resection was successfully and appropriately performed for a young patient with a giant retroperitoneal CFT with a view to achieving complete venous reconstruction and safe surgical margins for a potentially malignant tumor.

Synthesis and Immunoadjuvant Activity of 1-α-O- and 1-β-S-[(3R)-3-Tetradecanoyloxy-tetradecanoyl]-N-acetylmuramoyl-L-alanyl-D-isoglutamine Methyl Esters and Related Compounds

The 1-α-O- and 1-β-S-[(3R)-3-tetradecanoyloxytetradecanoyl] derivatives of N-acetylmuramoyl-L-alanyl-D-isoglutamine methyl ester (MDP methyl ester) were synthesized by coupling of the corresponding intermediate, the C-1-hydroxyl or C-1-β-thiol derivative of MDP methyl ester, with (3R)-3-tetradecanoyloxytetradecanoic acid. The immunoadjuvant activities of each product and their related compounds were examined.