Hepatic differentiation of mouse embryonic stem cells in a bioreactor using polyurethane/spheroid culture.

BACKGROUND: We have previously developed a hybrid artificial liver (HAL) using polyurethane foam (PUF)/hepatocyte spheroid culture. The PUF-HAL has been successfully scaled up to a clinical level. However, one of the most difficult problems for clinical application of HALs is obtaining a cell source. We now focused our attention on embryonic stem (ES) cells as a potential source for HAL. In this study, we investigated the differentiation of mouse ES (mES) cells into functional hepatocytes in the PUF-HAL module. METHODS: The PUF-HAL module included a cylindrical PUF block having many capillaries for medium flow. mES cells were immobilized in the module. To induce hepatic differentiation, growth factors were added to the culture medium. We evaluated cell density, gene expression analysis, and liver-specific functions. RESULTS: mES cells spontaneously formed spherical multicellular aggregates (spheroids) in the pores of PUF. mES cells proliferated by 20 days, achieving a high cell density (about 1 x 10(8) cells/cm3 PUF). Differentiating ES cells expressed endodermal-specific genes such as alpha-fetoprotein, albumin, and tryptophan 2, 3-deoxygenase. The activity of ammonia removal of mES cells per unit volume of the module was detectable by 15 days and increased with culture time. Maximal expression levels were comparable to those of primary (porcine and human) hepatocytes. SUMMARY: mES cells immobilized in the PUF module expressed liver-specific functions at high level, because of high cell density in culture and hepatic differentiation. These results indicated that PUF module-immobilized mES cells may be useful as a biocomponent of HALs.

Hepatic differentiation of embryonic stem cells in HF/organoid culture.

OBJECTIVE: The use of embryonic stem cells (ES cells) has recently received much attention as a novel cell source for various hybrid artificial organs. To use ES cells, it is necessary to be able to produce functional mature cells from ES cells in large quantities. We applied HF/organoid culture, where cultured cells formed cylindrical multicellular aggregates (organoids) in the lumen of hollow fibers, to mouse and cynomolgus monkey ES cells for hepatic differentiation. MATERIALS AND METHODS: ES cells were injected into hollow fibers. The hollow fibers were centrifuged to induce organoid formation and cultured in medium including factors for hepatic differentiation. To determine the characteristics of cells in the bundle, we evaluated gene expression and liver-specific functions. RESULTS: ES cells immobilized inside hollow fibers proliferated and formed cylindrical organoids. In mouse ES cell cultures, the expression of mRNAs of hepatocyte-specific genes increased with culture time. Ammonia removal activity detected at 15 days increased with culture time. Albumin secretion activity detected at 12 days increased by 21 days. In cynomolgus monkey ES cell cultures, ES cells showed spontaneous ammonia removal functions. The maximum levels of these functions per unit volume of the hollow fibers were roughly comparable to those of primary hepatocyte-organoids. CONCLUSIONS: ES cells differentiated into hepatocyte-like cells using the organoid culture technique. The results indicated that the combination of ES cells and an organoid culture technique was useful to obtain mature hepatocytes.

Development of articular cartilage grafts using organoid formation techniques.

In order to develop articular cartilage grafts, one must control shape and safety. We have developed scaffold-free culture methods in which the cells form multicellular aggregates (organoids). In this study, we applied the organoid culture method to chondrocytes attempting to reconstitute articular cartilage grafts. Primary rat costal chondrocytes and subcultured human articular chondrocytes were immobilized in hollow fibers by centrifugation at a density of 3 x 10(8) cells/cm3 to induce the formation of cylindrical-shaped organoids. To improve convenience, we developed a culture device to form sheet-shaped organoids (organoid-sheet). Primary bovine articular chondrocytes were cultured in this device. These organoids were evaluated by histological and gene expression analyses. In the primary rat culture system, chondrocytes formed cylindrical organoids in hollow fibers. Histochemical analysis revealed the presence of extracellular matrix (collagen and proteoglycan). The organoid maintained cartilage-specific gene expression (type II collagen, aggrecan) for 1 month of culture. In the subcultured human chondrocyte system, the organoid regained the decreased cartilage-specific gene expression. In the primary bovine culture system, the cells formed a 300 microm thickness organoid-sheet including abundant extracellular matrix. In conclusion, our organoid formation method was effective to form cartilage-like tissue. This result suggested that the technique may be applicable for the development of an articular cartilage graft.

Evaluation of a hybrid artificial liver module with liver lobule-like structure in rats with liver failure.

We studied the recovery of rats with fulminant hepatic failure (FHF) by treating them with our original hybrid artificial liver support system (HALSS). We developed an original artificial liver module having a liver lobule-like structure (LLS). This module consists of many hollow fibers regularly arranged in close proximity and hepatocyte aggregates (organoids) induced into the extra capillary space of the module by centrifugal force. The LLS module can express some liver specific functions at high levels and maintain them for several months in vitro. In this study, we evaluated the efficacy of our LLS-HALSS by using rats with FHF induced by a method that combined partial hepatectomy with hepatic ischemia. In the animal experiments, blood ammonia levels rapidly increased in the control group (sham-HALSS group). These rats died during or immediately after application of the sham-HALLS. On the other hand, in the LLS module application group (LLS-control group), the increase in blood ammonia was completely suppressed and all rats recovered. Blood constituents at 4 weeks after application were at normal levels, and the weight of the liver was the same as that of a normal rat. These results indicate that HALSS may be useful for treating liver failure patients until liver transplantation can be performed or until regeneration of the native liver occurs.

Formation of a sheet-shaped organoid using rat primary hepatocytes for long-term maintenance of liver-specific functions.

In recent years, use of hepatocyte aggregates has led to development of a hybrid artificial liver support system (HALSS) that has high performance. However, in general, their thickness is 100 microm or more, and generation of a dead cell layer due to oxygen exhaustion inside the aggregates has been a universal problem. The present study proposes a novel organoid culture method with better performance than previous organoid culture methods by forming a sheet-shaped organoid (organoid-sheet) with a thickness of approximately 100 microm. The cell number of the organoid-sheet was maintained at approximately 75% of the initial number at 4 days of culture. On the other hand, that of a cylindrical organoid (cylindroid), which formed inside of a plasma separation hollow fiber with 285 microm inner diameter in our previous study, decreased to approximately 50% within 2 days. The ammonia removal rate of the cells in the organoid-sheet was higher than that of the cells in the cylindroid on the first day, but it decreased during the culture time. At day 15, the rate was reduced by almost 50% with respect to the value on the first day. The cells in the cylindroid displayed a lower ammonia removal rate. A significant difference was not observed between the albumin synthesis rates of the two cultures on the first day. However, over a period of time the cells in the organoid-sheet showed a higher albumin synthesis rate than cells in the cylindroid. As this novel organoid maintains these functions for at least 1 month, it is expected to be applied for the development of a HALSS with higher performance.

Transient antiphospholipid antibodies associated with acute infections in children: a report of three cases and a review of the literature.

We describe two previously healthy children who had multiple ecchymoses several days after acute infection. In both cases, the prothrombin time (PT) and the activated partial thromboplastin time (APTT) were prolonged. Further examinations revealed the presence of lupus anticoagulant (LA), phosphatidylserine-dependent antiprothrombin antibodies (aPS/PT), and low serum complement. In both cases, we confirmed the presence of a serum immune complex. The patients' symptoms improved spontaneously within 1 week, and all laboratory data normalized within several months. We also describe another asymptomatic case positive for LA and aPS/PT presumably associated with cytomegalovirus infection. The prevalence of transient antiphospholipid antibodies associated with viral infections in children must be much higher than we expected. We have to take it into consideration when we see abnormal coagulation results, but the occurrence of significant bleeding symptoms is rare.

Differentiation effects by the combination of spheroid formation and sodium butyrate treatment in human hepatoblastoma cell line (Hep G2): a possible cell source for hybrid artificial liver.

The aim of this study was to investigate the feasibility of human hepatoblastoma cell line (Hep G2), which differentiates by spheroid formation, and treatment with sodium butyrate (SB) as a cell source for hybrid artificial liver (HAL). Hep G2 spontaneously formed spheroids in polyurethane foam (PUF) within 3 days of culture and restored weak ammonia removal activity. Treatment with SB, which is a histone deacetylase inhibitor, further increased the ammonia removal activity of Hep G2 spheroids in a concentration-dependent manner. The activation of ornithine transcarbamylase--a urea cycle enzyme--was significantly related to the upregulation of ammonia removal by spheroid formation, but scarcely contributed to the further upregulation following SB treatment. In contrast with ammonia removal, treatment with SB reduced the albumin secretion of Hep G2 spheroids in a concentration-dependent manner. In the PUF-HAL module in a circulation culture, the ammonia removal rate and albumin secretion rate (per unit volume of the module) of Hep G2 spheroids treated with 5 mM SB were almost the same as those of primary porcine hepatocyte spheroids. These results suggest that simultaneous use of spheroid formation and SB treatment in Hep G2 is beneficial in enhancing the functions of human hepatocytes with potential applications in regenerative medicine and drug screening.

Liver regeneration using a hybrid artificial liver support system.

We have developed two types of hybrid artificial liver support system (HALSS) that use hepatocyte organoid culture: (1) a PUF-HALSS comprising an artificial liver module using polyurethane foam (PUF), in which hepatocytes form spheroids in its pores, and maintained liver-specific functions for at least ten days in vitro; (2) an LLS-HALSS that uses a liver lobule-like structure (LLS) module containing hollow fibers with a microregular arrangement in which hepatocytes in the extra-fiber space of the module form the organoids by centrifugation that maintain liver-specific functions for at least two months in vitro. In preclinical experiments, a PUF-HALSS was applied to a pig having liver failure. To evaluate the effect of liver regeneration, a PUF- and an LLS-HALSS were applied to a rat having reversible hepatic failure. Each HALSS was effective in supporting liver function, stabilization of general conditions and recovery from liver failure state. These results indicate that these HALSS may be useful to treat liver failure patients until liver transplantation or until regeneration of the native liver.

Hepatocyte organoid culture in elliptic hollow fibers to develop a hybrid artificial liver.

A novel organoid culture was developed in which hepatocytes maintain high liver functions for more than several weeks in vitro. The main disadvantage of tissue-engineered organoids is the lack of a blood vessel structure between the aggregated cells. Because of depletion of oxygen, the thickness from the surface of an organoid at which hepatocytes can survive is limited. This study showed that a rat hepatocyte organoid that forms by using centrifugal force in a hollow fiber (HF) had a survival limit thickness of about 80 - 100 microm from the surface of the organoid. Based on the value, we designed an elliptic HF having less than 150 microm minor diameter by using a simple annealing method. All hepatocytes were supplied with oxygen and formed an organoid without a dead cell layer in this HF A hepatocyte organoid in an elliptic HF maintained ammonia removal activity twice as high as in the original HF for at least one month during culture. Albumin secretion activity of an organoid in an elliptic HF was also maintained for at least one month and was the same level as that of liver in a living body. In conclusion, organoid culture by using an elliptic HF seems to be a promising technique to develop a hybrid artificial liver.

Imaging studies in patients with malignant melanoma in the female genital tract.

The purpose of this study was to review magnetic resonance imaging (MRI) and pathologic features of primary malignant melanoma (melanoma) in the female genital tract. We retrospectively evaluated MRI in six women with melanoma of the genital tract. The signal intensity of the tumor on T1-weighted images (WI) was compared with the amount of melanin granules in hematoxylin-eosin stained sections of resected specimen. On T1WI, four melanomas showed a high signal intensity, one intermediate, and one low. The four melanomas with a high signal intensity on T1W1 were rich in melanin granules, while the one intermediate tumor had few granules. The other one was amelanotic. We believe that a high signal on T1WI is characteristic of primary melanotic melanoma of the female genital tract. Our findings suggest that it is strongly influenced by the presence of melanin granules.

Recovery of rats with fulminant hepatic failure by using a hybrid artificial liver support system with polyurethane foam/rat hepatocyte spheroids.

We studied the recovery of rats with fulminant hepatic failure (FHF) by treating them with our original hybrid artificial liver support system (HALSS). FHF was induced by a two-thirds partial hepatectomy and 10 minutes of hepatic ischemia. Rats with FHF were treated with a polyurethane foam/spheroid HALSS including 2.0 x 10(8) hepatocytes for 1 hour (HALSS group, n = 5), and with the same system without hepatocytes in the artificial liver module as a control experiment (sham-HALSS group, n = 3). The level of blood constituents, ammonia, glucose and creatinine, showed no major difference between the two groups at the end of treatment. All rats in the sham-HALSS group died within 5 hours after treatment. However, the level of blood constituents of rats with FHF in the HALSS group improved with time, and all rats in the HALSS group recovered. Liver tissue of rats treated with HALSS showed cell mitosis and improvement from injury. These results indicated that our HALSS has a strong possibility to induce recovery from hepatic failure.

Hemodynamics in the left gastric vein after endoscopic ligation of esophageal varices combined with sclerotherapy.

BACKGROUND AND METHODS: We examined the changes in portal hemodynamics after endoscopic variceal ligation (EVL) combined with endoscopic injection sclerotherapy (EIS) in relation to post-treatment relapse. The present study included 93 patients who underwent EVL-EIS combination therapy. Portal hemodynamics were examined by Doppler ultrasonography and percutaneous transhepatic portography (PTP). RESULTS: Therapy with EVL-EIS resulted in the complete disappearance of varices in 89 of 93 patients. Cumulative relapse-free rates (Kaplan-Meier method) were 75.8 and 50.2%, respectively, 1 and 3-5 years after treatment. At the end of treatment, the flow in the left gastric vein was examined by Doppler ultrasonography. In 50 of 63 patients, the flow remained hepatofugal. In 23 of these patients, PTP was performed at the end of treatment; selective left gastric venography did not reveal any palisade zone vessels or varices. However, fine blood vessels were seen around the lower esophagus in nine patients, only the paraesophageal vein was found in 10 patients and these two findings were present in four patients, indicating that collateral blood flow remained in the lower esophagus in 13 of 23 patients. These findings suggest that frequent relapse of varices results from insufficient blockage of blood flow from the left gastric vein to the lower esophagus. However, in patients with a patent paraesophageal vein, long-term effects obtained by EVL-EIS combination therapy were satisfactory. CONCLUSIONS: The pattern of the development of collateral left gastric veins represents important hemodynamic changes that predict the long-term prognosis of patients after treatment.

Transplantation of human neural progenitor cells to the vitreous cavity of the Royal College of Surgeons rat.

Human neural progenitor cells, originally isolated from prenatal donor tissue at 17 weeks of development, were cultured as neurospheres and transplanted to the vitreous cavity of dystrophic Royal College of Surgeons rats with, or without, cyclosporin A immunosuppression. Donor cells were either unlabeled or prelabeled, the latter utilizing incubation with BrdU or adenoviral modification to express green fluorescent protein. Recipients of various ages were examined at 1, 2, and 4 weeks postgrafting. Transplanted human neural progenitor cells survived in the host vitreous for at least 4 weeks and maintained expression of green fluorescent protein for at least 2 weeks. After 2 weeks in vivo, grafted cells differentiated morphologically, coincident with expression of the neuronal marker MAP, indicating mature neuronal differentiation. The extensive intraretinal migration previously shown using rat progenitor cells in the Royal College of Surgeons rat model was not seen in this experiment, suggesting that high levels of neuronal migration may depend at least in part upon species-specific molecular cues. Human neural progenitor cells represent a renewable source of multipotent human cells capable of in vivo neuronal development and a potential means of delivering therapeutic factors intraocularly. Human neural progenitor cells therefore provide a useful tool for studies of neural development and differentiation in the dystrophic eye.

Holmium laser incision technique for ureteral stricture using a small-caliber ureteroscope.

BACKGROUND AND OBJECTIVES: The holmium laser has a short absorption depth in tissue and possesses excellent properties both in ablation and hemostasis. We have performed endoscopic incision for ureteral stricture using the holmium laser through a small-caliber ureteroscope. METHODS: This method was used on five patients and seven ureters. The etiology of the stricture was stone scar in two patients, ureteroenteroanastomosis of Indiana urinary pouch in two, and primary in one. We used an 8F semi-rigid or 6.9F flexible ureteroscope. No prior procedures, such as balloon dilation, were necessary in any of the cases. The stricture was incised with the holmium laser using a 365-microm fiber through the working channel of the ureteroscope. The holmium laser operated at a wavelength of 2100 nm, with an output of 1.0 J/pulse at a rate of 10 Hz. After completion of the incision, a 12F Double-J catheter was left in for six weeks. RESULTS: The mean operative time was 89 minutes. The stricture resolved completely in all cases at an average follow-up of 8.6 months. CONCLUSIONS: The holmium laser incision for ureteral stricture using a small-caliber ureteroscope is an easy-to-perform, safe and effective procedure.

Clinical study on recurrence in bladder cancer patients undergoing total cystectomy--statistical analysis of factors related to recurrence.

A clinico-pathological study was performed retrospectively for 77 patients undergoing total cystectomy for primary transitional cell carcinoma of the urinary bladder between 1981 and 1995 to clarify the mode of recurrence, the risk factors which may affect recurrence following cystectomy and prognostic factors. Postoperative recurrence was recognized in 27 (35.1%) out of 77 patients and the one-, two- and three-year non-recurrent rates by the Kaplan-Meier method were 75.3, 64.9% and 63.3%, respectively. The duration from cystectomy to recurrence was 1 to 102 months with a mean of 12.1 months, and approximately 92.6% of recurrence occurred within two years. Among 27 patients with recurrence, pelvic recurrence, distant metastasis, both of them and urethral recurrence were recognized in 6 (22.2%), 18 (66.7%), 1 (3.7%) and 2 (7.4%), respectively as the first site of recurrence. The overall one-, three- and five-year cause-specific survival rates of the 77 patients were 84.7, 71.1% and 65.6%, respectively. Of the 27 patients with recurrence, 25 (92.6%) died of bladder cancer. Of the factors related to recurrence or prognosis, pathological stage, lymphatic invasion, venous invasion, type of infiltration and lymph node metastasis but not pathological grade or adjunctive chemotherapy were significant risk factors for recurrence and prognostic factors in univariate analysis. However, lymphatic invasion was the only significant risk factor for recurrence and prognosis in multivariate analysis using Cox's proportional hazard model.

Nuclear localization of beta-catenin in normal and carcinogenic endometrium.

We have previously shown that the connexin (Cx) 26 and 32 genes are expressed during the secretory phase of the human endometrium and that their expression is downregulated during the proliferative phase, suggesting a role for intercellular transduction in cell growth control in human endometrium. To further study the possible role of cell-to-cell interaction in growth regulation, we immunohistochemically analyzed 80 endometrial samples (30 of normal endometrium, 20 of endometrial hyperplasia, and 30 of endometrial cancer) for the expression of E-cadherin; alpha-, beta-, and gamma-catenin; adenomatous polyposis coli (APC) protein, and sex-steroid hormone receptors at three points in the cells: the cell-to-cell border, the cytoplasm, and the nucleus. In this study, moderate or strong staining of beta-catenin in the nuclei was observed in 60.0% of endometrial hyperplasia samples and 30.0% of endometrial cancer samples, although the beta-catenin gene was mutated in only two of the nine samples that showed the intensive nuclear staining. Western blotting analysis showed that the samples that had intense nuclear staining of beta-catenin had much higher expression of beta-catenin than the samples that did not have nuclear staining. Furthermore, normal endometrium showed nuclear localization, especially in the mid- and late-proliferative and early-secreting phases of the menstrual cycle. The results suggest that the nuclear localization of beta-catenin observed in endometrial hyperplasia and endometrial cancer, as in other tumors, implies that beta-catenin/Wnt-1 signal transduction is highly activated in carcinogenesis of the endometrium as well as in normal physiological conditions.

Formation of porcine hepatocyte spherical multicellular aggregates (spheroids) and analysis of drug metabolic functions.

Porcine hepatocytes are used in the hybrid artificial liver support system that we are developing because of their high level of liver functions in vitro and because human hepatocytes can not be used in Japan for ethical reasons. Spherical multicellular aggregates or spheroids have been found to be effective in vitro for long-term maintenance of liver functions. Therefore, we formed spherical multicellular aggregates (spheroids) of primary porcine hepatocytes using a polyurethane foam (PUF) as a culture substratum and analyzed their drug metabolic functions in vitro. Primary porcine hepatocytes inoculated into the pores of a flat PUF plate (25 x 25 x 1 mm), spontaneously formed spheroids within the range of 100 to 150 mum in diameter 24 to 36 h after inoculation. The formed spheroids were attached to the bottom surface of the PUF pores, and their morphology and viability were maintained for more than 12 days. The P-450 activity in the spheroids of porcine hepatocytes was demonstrated by detecting production of monoethylglycinexylidide from lidocaine. In addition, the conjugation enzyme activity was demonstrated by detecting glucuronidation and sulfation of acetaminophen. These activities were maintained for 12 days at a level twice as high as in the monolayer culture. This result shows that the porcine hepatocyte spheroids formed by using PUF can maintain the drug metabolic functions important in a hybrid artificial liver device. Consequently, culturing porcine hepatocyte spheroids using PUF seems to be promising for development of a hybrid artificial liver.

Formation of cylindrical multicellular aggregate (cylindroid) and expression of liver specific functions of primary rat hepatocytes.

In our studies of the development of a hybrid artificial liver, we investigated the formation of cylindrical multicellular aggregate (cylindroid) of primary rat hepatocytes on a pressed sheet of polyurethane foam (pressed-PUF) as a culture substratum. Hepatocytes formed cylindroids by attaching to a pressed-PUF surface, peeling off from the surface and aggregating. The diameter and length of most cylindroids were approximately 200-500 mum and 500 mum-2 mm, respectively. The activities of liver specific functions (albumin secretion and ammonia metabolism) of hepatocyte cylindroids were equivalent to or higher than those of hepatocyte spheroids. These results suggest that hepatocyte cylindroids can maintain highly differentiated functions longer than hepatocyte spheroids, and that a PUF/cylindroid culture may be effective to develop of a hybrid artificial liver.

[Mobilization of peripheral blood stem cells in advanced ovarian cancer].

High-dose chemotherapy with hematopoietic support has been expected to improve the survival of advanced ovarian cancer patients in recent years. An essential component of such treatment has been the ability to collect and reinfuse a large number of peripheral blood stem cells (PBSCs) following high dose therapy. This study was designed to determine which clinical and hematological factors would be better indicators to collect the proper volume of PBSCs. Thirteen patients received a total of 24 courses of induction chemotherapy and 69 of apheresis. We usually mobilized stem cells using CEP chemotherapy (cisplatin 50-70 mg/m2, epirubicin 50 mg/m2 and cyclophosphamide 1.5 g/m2) with G-CSF and CEE regimen (cyclophosphamide 2.0 g/m2, epirubicin 50 mg/m2, and etoposide 50 mg/m2) as a salvage for mobilization. We obtained an average 5 x 10(6)/kg of CD34+ cells for 3 days as one course. The number of CD34+ cells collected significantly depended on the platelets and reticulocytes on the first day of apheresis, but not a nadir of WBCs. It is concluded that apheresis should be started on recovery of WBCs to 5,000-10,000/microliters, of immature granulocytes to > or = 10% and of reticulocytes to > or = 20%. This study confirmed the feasibility of collecting enough PBSCs to use standard chemotherapy of ovarian cancer patients.