Establishment of a mouse thymic epithelial cell line, IT-76MHC and a brief review on cultured thymic epithelial cells

Interactions between thymocytes and thymic stromal cells are essential for thymocyte differentiation, but little evidence has been presented to directly show in vivo functions or interactions of the stromal cells. Among the stromal cells, the thymic epithelial cell has been considered to have profound effect on thymocyte differentiation and maturation. The calcium-depleted medium, originally developed for the culture of mouse epidermal cells, was applied for the culture of the mouse thymic epithelial cells, and successfully, an epithelial cell line, IT-76MHC was obtained from the mouse thymus. IT-76MHC cells were identified as distinct mouse thymic epithelial cells by 1/ mosaic-like arrangement, 2/ presence of well-developed desmosome and 3/ tonofilaments, 4/ positivity for cytokeratin, and 5/ induced expression of MHC class I and II by IFN-gamma treatment. IGF-1, IGF-2, oxytocin and vasopressin were also detected immunohistochemically in IT-76MHC cells. Furthermore, the IT-76MHC thymic epithelial cells, when injected intrathymically in the allogeneic mouse, prolonged the survival of skin graft from the same donor strain that IT-76MHC cells were derived. These results demonstrate that the thymic epithelial cell line IT-76MHC produces modest thymocyte survival factors as well as a growth suppressor, and that IT-76MHC cells have the ability to induce transplantation tolerance probably through their expression of MHC class I and II molecules. Taken altogether, the IT-76MHC thymic epithelial cells have been proved to be useful tools to better understand the in vivo functions of thymic epithelial cells, and to gain a deep insight into their involvement in the critical selection process of thymocytes which still remains obscure. Finally and additionally, literatures so far reported on thymic epithelial cells in culture, especially lines and clones, are reviewed and their identity as well as their functions are discussed.

Experience with artificial liver support in 16 living related liver transplant recipients

This study was a retrospective investigation about the indication and efficacy of artifical liver support for liver transplant recipients. Apheresis was performed in 16 of 41 patients subjected to living related liver transplantation (LRLTx) as articial liver support, including plasmapheresis (PP) in 13 cases, continuous hemodiafiltration (CHDF) in 7 cases, and plasma adsorption (PA) in 2 cases. One patient with cryptogenic liver cirrhosis was subjected to PP before the LRLTx, and the result was satisfactory. On the contrary, the results of PP and CHDF for graft, respiratory, or cardiac failure were not acceptable. Only 1 patient survived despite multiple organ failure. Both PP and PA for patients with hyperbilirubinemia were effective and improved their critical conditions. We conclude that apheresis for liver transplant patients is effective to treat hyperbilirubinemia, but it is not indicated for respiratory and cardiac failure nor for hepatic failure.

Tissue engineering of the small intestine by acellular collagen sponge scaffold grafting

Tissue engineering of the small intestine will prove a great benefit to patients suffering from short bowel disease. However cell seeding in tissue engineering, such as fetal cell use, is accompanied by problems of ethical issues, rejection, and short supply. To overcome these problems, we carried out an experimental study on tissue engineering of the small intestine by acellular collagen sponge scaffold grafting. We resected the 5 cm long jejunum from beagle dogs and reconstructed it by acellular collagen sponge grafting with a silicon tube stent. The graft was covered with the omentum. At 1 month after operation, the silicon stent was removed endoscopically. Animals were sacrificed 1 and 4 months after operation, and were examined microscopically. Neo-intestinal regeneration was observed and the intestinal mucosa covered the luminal side of the regenerated intestine across the anastomosis. Thus, the small intestine was regenerated by tissue engineering technology using an acellular collagen sponge scaffold.

Rehabilitating patients with hepatopulmonary syndrome using living-related orthotopic liver transplant: a case report

The objective of this study was to rehabilitate a patient with hepatopulmonary syndrome (HPS) who underwent living-related orthotopic liver transplantation (LT). HPS is rare; it presents severe complication in patients with liver disease. A 17-year-old woman with HPS developed portal hypertension after undergoing Kasai's surgery for congenital biliary atresia and underwent a living-related orthotopic LT. After LT, her allograft functioned well, but she continued to have hypoxemia and orthodeoxia. She was referred for rehabilitation for disuse atrophy, contracture of hip and shoulder joints, left common peroneal nerve palsy, and rehabilitation for respiratory dysfunction. By day 106 after LT, her orthodeoxia and disuse atrophy had improved because of daily exercise training and active joint range of motion exercises. Patients with HPS have orthodeoxia and poor responsiveness to oxygen therapy, and correction of hypoxemia after LT may be delayed. Therefore, rehabilitation approaches for patients with HPS should be based on the pathophysiology and characteristics of HPS.

Comparison of intratumoral distribution of 99mTc-MIBI and deoxyglucose in mouse breast cancer models

The aims of this study were to evaluate the distribution of 99mTc-methoxyisobutylisonitrile (MIBI) in 3 animal models of breast cancer, the effect of radiotherapy on 99mTc-MIBI uptake, and the relationship between uptake and microvessel density.

METHODS

We used syngeneic, subcutaneously transplanted FM3A, MM48, and Ehrlich mouse breast cancer. 99mTc-MIBI and FDG were injected intravenously, and tumor uptake was measured 30 min later. Double-tracer macroautoradiography (ARG) images were prepared with 99mTc-MIBI and 2-deoxy-D-[1-14C]-glucose (14C-DG), analyzed quantitatively, and compared with histology. The radiotherapeutic effects of 20 Gy x-ray irradiation were monitored by measuring tumor volume, tumor uptake, and ARG findings using 99mTc-MIBI and FDG in FM3A tumors. Microvessel density was quantified by immunohistochemical staining for CD34 and compared with ARG using 99mTc-MIBI in FM3A tumors.

RESULTS

FM3A, MM48, and Ehrlich tumors showed different growth rates and radiosensitivities. Uptake of FDG, but not of 99mTc-MIBI, correlated significantly with growth rates. Compared with 14C-DG, 99mTc-MIBI accumulated more in cancer cells and less in infiltrating fibroblasts and macrophages in all tumor models. Irradiation significantly decreased 99mTc-MIBI uptake, but a rapid increase was noted at recurrence on day 7. Changes in FDG uptake were not significant at recurrence. Microvessel density in tumor tissue correlated significantly with 99mTc-MIBI uptake on ARG.

CONCLUSION

Accumulation of 99mTC-MIBI in cancer cells is preferential and can be used as a sensitive marker to examine the response to radiotherapy. Angiogenesis seems to enhance accumulation of 99mTc-MIBI in tumors. These characteristics may be favorable for tumor imaging using 99mTC-MIBI.

Laparoscopic partial splenectomies for true splenic cysts. A report of two cases

The goals of treatment for nonparasitic splenic cyst include elimination of the cyst and prevention of recurrence. We treated two cases of true splenic cysts by successfully performing partial splenectomies via a laparoscopic approach. Herein we describe the surgical technique used and tactical aspects. Laparoscopic partial splenectomies can be a definitive treatment for true splenic cysts in that they preserve splenic function and prevent recurrence.

Significance of tumor associated tissue eosinophilia and other inflammatory cell infiltrate in early esophageal squamous cell carcinoma

Tumor associated inflammatory cell infiltration plays an important role in the biological behavior of cancer as one of the carcinoma-stromal interactions. In this study, we characterized inflammatory cell infiltration on esophageal squamous cell carcinoma (SqCC) and correlated the findings with various clinicopathological factors, including clinical outcome of the patients, in order to study its biological significance. We examined 35 cases of surgically resected early esophageal SqCC or carcinoma with invasion limited to the submucosal layer. We evaluated the abundance of CD4+ T-cell, CD8+ T-cell, B-cell, plasma cell, CD68+ macrophage, neutrophil and eosinophil in the stroma adjacent to the tumor and correlated these findings with clinicopathological factors. The cases without LN metastasis had a significantly larger number of tumor associated eosinophils than those with LN metastasis. Primary lesions in cases without LN metastasis tended to demonstrate more CD68+ macrophage infiltration than those with LN metastasis, but the difference did not reach statistical significance. In addition, the cases with more than 50 eosinophils and macrophages per 10 high power field in the primary lesion demonstrated a significantly smaller incidence of LN metastasis than those with less than 50 eosinophils and macrophages per 10 high power field. Thus tumor associated tissue eosinophila, also known as TATE, is considered to be involved in the biological behaviour of early esophageal SqCC, especially in their metastatic potential.

Frequent loss of copy number on the long arm of chromosome 21 in human esophageal squamous cell carcinoma

To understand the molecular pathogenesis of human esophageal cancer, we performed a comparative genomic hybridization (CGH) analysis using 10 esophageal squamous cell carcinomas. Frequent gains of 1q, 3q, 7p, 7q, 8q, 11q, and 20q and losses of 3p, 4p, 4q, 5q, 9p, 11p, 11q, 13q, 18q, 21q, and Y were observed. Among these regions, 21q has not yet been investigated in detail. We performed an allelotype study using 55 squamous cell carcinomas of the esophagus and 20 microsatellite markers on 21q and found LOH in 36 cases (65%): 22 (61%) of 36 cases with LOH indicated allelic loss in all informative loci, suggesting loss of the whole chromosome arm 21q, and five smallest regions of overlap were found. Our present results suggest the existence of a tumor suppressor gene(s) that plays a role in the genesis of squamous cell carcinoma of the esophagus.

A chemiluminescent assay for hydroperoxide level of phosphatidylcholine hydroperoxide fraction purified by two Sep-Pak cartridges in biological samples

A chemiluminescent assay for hydroperoxide level of phosphatidylcholine hydroperoxide (PCOOH) fraction purified from biological samples was presented. This method utilized of two Sep-Pak cartridges. A lipid soluble fraction was isolated from each homogenized tissue or blood by Folch's method. The mixture of phosphatidylcholine (PC) and PCOOH was separated from the lipid soluble fraction by a Sep-Pak silica cartridge. A Sep-Pak tC18 cartridge made complete separation of both PCOOH and PC possible. The hydroperoxide level of PCOOH fraction was quantified by the reaction with ferrous ion using 2-methyl-6-[p-methoxyphenyl]-3,7-dihydroimidazo[1,2-a]pyrazin++ +-3-one as a chemiluminescent dye. The mixture of positional isomers, 1-hexadecanoyl-2-[9, or 10-hydroperoxyl octadecanoyl]-sn-glycero-3-phosphocholine was used as an authentic standard. The good recovery rate for authentic PCOOH of 87.1 +/- 11.6% (mean +/- S.E., n = 4) was obtained by using two Sep-Pak cartridges. Linear calibration curve was obtained in the range from 2.5 to 20 nmol, and the detection limit of the standard was 10 pmol (signal-to-noise ratio > 3). This method was applied to the investigation of the lipid peroxidation induced by reperfusion of the liver with cold preservation, mimicking liver transplantation in rats. The effect of liposome-encapsulated dichloromethylene diphosphonate (LEDD), which eliminate of Kupffer cells to prevent the generation of oxygen radicals on the lipid peroxidation, was compared with the untreated group as a control. After 1 h reperfusion at 37 degrees C the hydroperoxide level obtained the liver without preservation in the untreated group was 12.4 +/- 2.4 nmol/100 mg lipid (n = 4) and levels increased significantly by prolongation of the preservation time. On the other hand, the hydroperoxide level in the LEDD treated group did not change up to 24 h preservation. These results suggest that this improved assay for hydroperoxide level of PCOOH fraction in biological samples can be applied to investigations involving lipid peroxidation because of its simplicity and accuracy.

Angiogenesis inhibition by transdominant mutant Ets-1

The expression of transcription factor Ets-1 is induced in endothelial cells (ECs) by angiogenic factor; and in turn Ets-1 converts ECs to angiogenic invasive phenotype. In order to control angiogenesis, we constructed a transdominant mutant Ets-1 (TMEts-1) which acts as a dominant negative molecule. This molecule inhibited the DNA binding and the transactivation activity of the wild-type Ets-1. Stable transfection of murine endothelial cell line MSS31 cells with the TMets-1 gene impaired angiogenic activities including proliferation, migration, invasion, and tube formation in type-1 collagen gel. Finally, we incorporated the TMets-1 gene into a non-proliferative adenovirus vector, designated as AdTMets-1. AdTMets-1 significantly inhibited angiogenesis in the Matrigel plugs injected into the subcutaneous tissue of C57BL mice. These results indicate that TMets-1 would be a tool for angiogenic inhibition.

Usefulness of quantitative real-time polymerase chain reaction in following up patients with Epstein-Barr virus infection after liver transplantation

BACKGROUND

Post-transplant lymphoproliferative disease (PTLD), which is mainly induced by Epstein-Barr virus (EBV) infection, is a cause of significant morbidity and mortality for patients undergoing liver transplantation, especially when it is detected at such an advanced stage as monoclonal malignant lymphoma.

METHODS

In this series, 6 of 22 liver transplant patients suffered from EBV infection. We tested quantitative DNA (Qt-DNA) by real-time polymerase chain reaction (PCR), qualitative DNA in plasma (Q1-pDNA) by PCR, and EBV-encoded mRNA 1 (EBER 1) by in situ hybridization to clarify which of them is a better marker for the early diagnosis and prediction of EBV-associated disorders.

RESULTS

Four had signs or symptoms of PTLD, but 2 did not develop individualized lymphoid lesions. In all patients, both Qt-DNA and EBER 1 exceeded the cut-off level of 10(2.5) copies/microg DNA and 0.002%, respectively, at the time of diagnosis. In 2 patients, when Qt-DNA had a poor decline, EBER 1, even if it seemed to decrease after antiviral therapy, increased again after a few months and the clinical symptoms recurred. In 2 patients, Qt-DNA and EBER 1 increased again after a few months of antiviral therapy, and Q1-pDNA remained positive, whereas, in 3 patients, no reaction of EBV could be detected once Q1-pDNA became negative, even after the cessation of therapy.

CONCLUSIONS

These results suggest that real-time PCR for Qt-DNA was more sensitive to the real-time activity of EBV and that Q1-pDNA could indicate when to stop antiviral therapy.