Long-term extensive expansion of mouse hepatic stem/progenitor cells in a novel serum-free culture system

BACKGROUND & AIMS

The liver has high regenerative potential. We attempted to establish a novel culture system for extensive expansion of fetal mouse hepatic stem/progenitor cells and to characterize cultured cells.

METHODS

Hepatic spheroids collected from 6-day floating cultures were cultured on collagen-coated dishes in serum-free conditions in medium containing growth factors. Cultured cells were mainly characterized by immunocytochemistry and flow cytometry or transplanted into adult mice.

RESULTS

Approximately 400 expanding hepatic spheroids were generated from every 1 x 10(6) fetal liver cells. Subsequently, highly replicative colonies were subcultured with maintaining colony formation on collagen-coated dishes. These colonies consisted of small immature alpha-fetoprotein-positive cells and hepatocytic and cholangiocytic lineage-committed cells. The immature alpha-fetoprotein-positive cells could be expanded in a reproducible manner at least 5 x 10(5)-fold (which involved at least 30 passages over >6 months) without losing differentiation potential. Flow cytometric analysis showed that all cultured cells expressed CD49f, but not CD34, Thy-1, c-kit, or CD45. Nearly 15% of the cells expressed Sca-1, and approximately 5%-20% of the cells were side population cells. Both sorted side population cells and Sca-1-positive cells (especially side population cells) produced a large number of alpha-fetoprotein-positive cells and lineage-committed cells. Expanded cells had bidirectional differentiation potential and improved serum albumin levels in mice with severe liver damage.

CONCLUSIONS

Long-term extensive expansion of transplantable hepatic stem/progenitor cells was reproducibly achieved in a novel serum-free culture system. Moreover, this culture system yielded side population and Sca-1-positive cell populations that included hepatic stem/progenitor cells with differentiation and proliferation properties.

Serious cardiac and pulmonary calcification in a young peritoneal dialysis patient: potential role of continuous correction of acidosis

We describe a 40-month-old male infant with renal failure, treated with peritoneal dialysis, who developed massive calcification of soft tissues including the heart and lungs with subsequent cardiopulmonary insufficiency. A diagnosis of Jeune syndrome was made. After starting peritoneal dialysis, the patient exhibited an intractable metabolic acidosis of unknown etiology necessitating treatment with intravenous or oral sodium bicarbonate. Myocardial calcification was first detected by 2-dimensional echocardiography performed 3 months after starting dialysis. The patient was not suitable for renal transplantation because of his cardiac dysfunction and died of cardiac and respiratory failure at the age of 6 years. Although the patient exhibited a variety of risk factors for ectopic calcification including hyperphosphatemia, hyperparathyroidism, high calcium-phosphate product and treatment with vitamin D, the early and massive soft tissue calcification may have been accelerated by correction of the metabolic acidosis. Therefore, the use of sodium bicarbonate may be involved in the etiology of the myocardial calcification.

Second Transplantation from HLA 2-Loci-Mismatched Mother for Graft Failure Due to Hemophagocytic Syndrome after Cord Blood Transplantation

A 7-year-old girl with acute myelogenous leukemia with multilineage dysplasia received unrelated cord blood transplantation but developed hemophagocytic syndrome (HPS) after sepsis with methicillin-resistant coagulase-negative staphylococci before engraftment. Bone marrow aspiration on day 20 revealed a markedly increased number of activated macrophages showing hemophagocytosis. The presence of donor-type chimera in the bone marrow was confirmed at that time. We therefore quickly started immunosuppressive and antibacterial treatment. Although her condition gradually improved, the patient suffered graft failure due to HPS. She received peripheral blood stem cell transplantation from her HLA 2-loci-mismatched mother on day 54 and continued in complete remission 12 months after the second transplantation. The results in this case suggested that because of fetomaternal microchimerism it may be useful to select an HLA-haploidentical mother as a backup donor for stem cell transplantation.

Repeated gamma knife radiosurgery for multiple metastatic brain tumours

BACKGROUND

The effectiveness of repeated gamma knife radiosurgery (GKS) for the treatment of multiple metastatic brain tumours was evaluated.

METHODS

This study included 16 patients with 242 tumours, 10 men and 6 women with a mean age of 60.3 years at initial GKS, who underwent GKS four times or more for newly developed metastatic tumours.

FINDINGS

Sixteen patients underwent a total of 83 GKS procedures (range 4 to 8, mean 5.2). The mean number of metastases at each GKS procedure was 2.9 and the number of tumours tended to increase at the 5th GKS procedure compared with the 1st, but not significantly. The mean interval between each procedure was 4.8 months and was not significantly different. Median survival was 22.4 months (range 9.4-78.9 months) and the primary site was not correlated with survival time. The total number of treated tumours tended to correlate to survival time, but not significantly. Use of adjuvant whole brain radiation also had no significant effect on survival time. The Karnofsky performance status was maintained at more than 70 in most patients, but decreased significantly between initial and final GKS. Death due to progression of brain lesions occurred in only about 30% of patients regardless of the multiple newly developed brain metastases.

CONCLUSIONS

Repeated radiosurgery for brain metastases is effective and relatively long survival can be expected in some patients associated with a low risk of radiation-induced injury.

Betulinic acid augments the inhibitory effects of vincristine on growth and lung metastasis of B16F10 melanoma cells in mice

We examined the antitumour effect of a combination of betulinic acid (BA) and vincristine (VCR) on murine melanoma B16F10 cells in vitro and in vivo. Betulinic acid, a pentacyclic triterpene, showed a synergistic cytotoxic effect on melanoma cells by combinational use of VCR. Betulinic acid and VCR induced cell cycle arrest at different points (BA at G1 phase and VCR at G2/M phase) and caused apoptosis in B16F10 melanoma cells. In the in vivo study, VCR inhibited metastasis of tumour cells to the lung. The addition of BA to VCR augmented suppression of the experimental lung metastasis of melanoma cells in C57BL/6 mice. The number of lung nodules of more than 1 mm in diameter in mice treated with BA and VCR was less than that in mice treated with VCR alone. These results suggest that BA is an effective supplement for enhancing the chemotherapeutic effect on malignant melanoma.

Rapid improvement of paraplegia caused by epidural involvements of Burkitt's lymphoma with chemotherapy

STUDY DESIGN

Case report.

OBJECTIVE

The authors present a case of atypical Burkitt's lymphoma with multiple epidural involvements.

SUMMARY OF BACKGROUND DATA

Spinal cord compression in children is an emergency that requires urgent attention to minimize neurologic dysfunction. Although it is not life-threatening in most patients, cord compression can cause severe neurologic morbidity.

MATERIALS AND METHODS

Because the patient showed rapid neurologic deterioration, we started chemotherapy and high-dose steroids without laminectomy or radiotherapy immediately after a tumor biopsy from the left mandible.

RESULT

The combined therapies were very effective and his neurologic symptoms improved immediately. The epidural involved masses disappeared in imaging studies after the first course of chemotherapy including methylprednisolone (20 mg/kg per day for 3 consecutive days and gradually tapered off over 2 weeks), vincristine (1.5 mg/m2 per day), cyclophosphamide (2 g/m2 per day for 2 days) and pirarubicin (40 mg/m2 per day). After completing seven courses of chemotherapy, the patient is now fully ambulant.

CONCLUSION

Considering the severe late effects of laminectomy and radiotherapy, chemotherapy should be considered as a first choice of treatment for spinal cord compression caused by malignant lymphoma.

Development of both human connective tissue-type and mucosal-type mast cells in mice from hematopoietic stem cells with identical distribution pattern to human body

The transplantation of primitive human cells into sublethally irradiated immune-deficient mice is the well-established in vivo system for the investigation of human hematopoietic stem cell function. Although mast cells are the progeny of hematopoietic stem cells, human mast cell development in mice that underwent human hematopoietic stem cell transplantation has not been reported. Here we report on human mast cell development after xenotransplantation of human hematopoietic stem cells into nonobese diabetic severe combined immunodeficient (NOD/SCID)/gamma(c)(null) (NOG) mice with severe combined immunodeficiency and interleukin 2 (IL-2) receptor gamma-chain allelic mutation. Supported by the murine environment, human mast cell clusters developed in mouse dermis, but they required more time than other forms of human cell reconstitution. In lung and gastric tract, mucosal-type mast cells containing tryptase but lacking chymase located on gastric mucosa and in alveoli, whereas connective tissue-type mast cells containing both tryptase and chymase located on gastric submucosa and around major airways, as in the human body. Mast cell development was also observed in lymph nodes, spleen, and peritoneal cavity but not in the peripheral blood. Xenotransplantation of human hematopoietic stem cells into NOG mice can be expected to result in a highly effective model for the investigation of human mast cell development and function in vivo.

Gamma knife radiosurgery for metastatic tumours in the brain stem

BACKGROUND

Stereotactic radiosurgery has become important in the treatment of metastatic brain tumours and is often the first choice modality for eloquent or deep locations such as the brain stem. This study evaluated the efficacy of gamma knife radiosurgery (GKS) for the treatment of brain stem metastases.

METHODS

The medical records of 25 patients with 31 tumours, 11 men and 14 women aged 42 to 78 years (mean 57.1 years), who underwent GKS for metastatic tumours in the brain stem were retrospectively reviewed. The results of GKS were evaluated according to the change in tumour size on neuro-imaging.

FINDINGS

The most common location of the primary malignancy was the lung followed by the breast. Adenocarcinoma was found in 19 patients (24 lesions). No case of squamous cell carcinoma was found. The mean calculated tumour volume was 2.1 cm(3) and the mean prescription dose to the tumour margin was 13.0 Gy. Mean duration of neuro-imaging follow up was 5.2 months and the overall tumour control rate was 77.4%. There was a significant correlation between the marginal dose delivered and the effect on neuro-imaging. New radiation-induced injury in the surrounding brain occurred in only 2 patients.

INTERPRETATION

GKS for brain stem metastases using a marginal dose of 15 Gy or less is effective and relatively safe. Accurate targeting of the tumour and safe dose planning are essential to obtain satisfactory results with GKS for brain stem metastases.

Esophageal actinomycosis after allogeneic peripheral blood stem cell transplantation for extranodal natural killer/T cell lymphoma, nasal type

We report a 19-year-old man with extranodal natural killer (NK)/T cell lymphoma, nasal type treated by allogeneic peripheral blood stem cell transplantation (allo-PBSCT). His lymphoma was chemoresistant, and disseminated during local radiotherapy. The patient received allo-PBSCT from his HLA-1 locus mismatched sister using busulfan (BU), cyclophosphamide (CY) and VP-16 as the conditioning regimen. His course was complicated by esophageal actinomycosis 9 months after transplantation, which resulted in the rupture of the right common carotid artery. These observations suggest that actinomycosis should be monitored carefully after transplantation in patients who have received local radiation therapy before the procedure.

Metabolic fate of pitavastatin, a new inhibitor of HMG-CoA reductase: similarities and difference in the metabolism of pitavastatin in monkeys and humans

1. To elucidate any potential species differences, the in vitro metabolism of pitavastatin and its lactone was studied with hepatic and renal microsomes from rats, dogs, rabbits, monkeys and humans. 2. With the addition of UDP-glucuronic acid to hepatic microsomes, pitavastatin lactone was identified as the main metabolite in several animals, including humans. 3. Metabolic clearances of pitavastatin and its lactone in monkey hepatic microsome were much greater than in humans. 4. M4, a metabolite of pitavastatin with a 3-dehydroxy structure, was converted to its lactone form in monkey hepatic microsomes in the presence of UDP-glucuronic acid as well as to pitavastatin. These results implied that lactonization is a common pathway for drugs such as 5-hydroxy pentanoic acid derivatives. 5. The acid forms were metabolized to their lactone forms because of their structural characteristics. 6. UDP-glucuronosyltransferase is the key enzyme responsible for the lactonization of pitavastatin, and overall metabolism is different compared with humans owing to the extensive oxidative metabolism of pitavastatin and its lactone in monkey.

Metabolic fate of pitavastatin, a new inhibitor of HMG-CoA reductase: human UDP-glucuronosyltransferase enzymes involved in lactonization

1. Pitavastatin is a potent competitive inhibitor of HMG-CoA reductase little metabolized in hepatic microsomes. Pitavastatin lactone, which can be converted back to the unchanged form, is the major metabolite of pitavastatin in humans. To clarify the mechanism of the lactonization of pitavastatin and the metabolic properties of the lactone, we performed experiments in vitro. 2. On addition of UDP-glucuronic acid, human hepatic microsomes produced pitavastatin lactone and an unknown metabolite (UM-2). UM-2 was converted to its unchanged form by enzymatic hydrolysis and to a lactone form non-enzymatically. Using several human UGT-expressing microsomes, UGT1A3 and UGT2B7 were principally responsible for glucuronidation of pitavastatin leading to lactonization. 3. No marked difference in intrinsic clearance between pitavastatin and its lactone form was detected in human hepatic microsomes. 4. Pitavastatin lactone showed no inhibitory effects on CYP2C9- and CYP3A4-mediated metabolism of model substrates in contrast to other HMG-CoA reductase inhibitors. 5. The mechanism of pitavastatin lactone formation has been clarified, in that glucuronidation by UGT occurs first followed by lactonization via an elimination reaction. It was also found that pitavastatin lactone demonstrates no drug-drug interactions.

Suppression of mediastinal metastasis by uracil-tegafur or cis-diamminedichloroplatinum(II) using a lymphogenous metastatic model in a human lung cancer cell line

PURPOSE AND EXPERIMENTAL DESIGN

The extent of lymphatic metastasis is the most important factor in the prognosis for non-small cell lung cancer (NSCLC). Therefore, suppression of lymphatic metastasis provides an improvement in survival time in lung cancer patients. We established a new patient-like model for lung cancer metastasis by orthotopic implantation in severe combined immunodeficiency (SCID) mice and demonstrated the lymphogenous spread histologically using human NSCLC cell lines. The cardinal features of this model are a simple procedure and a similarity to the metastatic form of human lung cancer. The purpose of this study is to assess the inhibitory action of uracil-tegafur (UFT) and cis-diamminedichloroplatinum(II) (CDDP) on lymphatic metastasis and life span prolongation in our lymphogenous metastatic model system using SCID mice.

RESULTS

The inhibition ratios of mediastinal lymph node metastasis were 86.2, 94, and 92.1% for 12 mg/kg body UFT, 17 mg/kg body UFT, and 10 mg/kg body CDDP, respectively. The administration of anticancer drugs prolonged the life span by 4.6 days (17 mg/kg body UFT) and 8 days (10 mg/kg body CDDP) in MST.

CONCLUSION

We demonstrated that UFT alone and CDDP alone suppressed mediastinal metastasis and prolonged the life span in our lymphogenous metastatic model. Regardless of the administration route and characteristics of anticancer drugs, cytostatic or cytotoxic, our model is capable of evaluating the inhibitory effect of drugs on lymphatic metastasis. This model should make an important contribution to our understanding of the mechanism and selection of drugs for antilymphatic metastasis in lung cancer.

Primary refractoriness to platelet transfusion caused by Nak(a) antibody alone

BACKGROUND AND OBJECTIVES

Anti-Nak(a), a platelet-specific antibody, occasionally causes platelet-transfusion refractoriness (PTR) together with human leucocyte antigen (HLA) antibodies. Anti-Nak(a) usually appears after frequent platelet transfusions or pregnancy. We report the first case of PTR caused by anti-Nak(a) alone.

MATERIALS AND METHODS

A 19-year-old male patient with testicular tumour showed PTR when receiving his first transfusion of platelets. Screening for platelet antigens and platelet antibodies revealed that he had type I CD36 (Nak(a)) deficiency and that anti-Nak(a), but not anti-HLA, was present before he received his first transfusion.

RESULTS

The transfusion of Nak(a)-negative, but HLA non-selected, platelets was effective in raising the platelet count.

CONCLUSION

Clinically significant Nak(a) antibody was present as naturally occurring antibody in a platelet glycoprotein IV (CD36)-negative non-transfused male patient.

Simultaneous determination of taxol and its metabolites in microsomal samples by a simple thin-layer chromatography radioactivity assay--inhibitory effect of NK-104, a new inhibitor of HMG-CoA reductase

The inhibitory effect of NK-104, a potent inhibitor of HMG-CoA reductase, on taxol metabolism was examined using radio-TLC. This method is described for in vitro measurement of taxol metabolites as an alternative to the commonly used HPLC assay. After incubation of 14C-taxol with human liver microsomes, the supernatants were developed using a solvent system consisting of toluene-acetone-formic acid (60:39:1, v/v) and quantified with a bioimaging analyzer. The described method provides a valuable tool for the simultaneous determination of unchanged taxol and its major metabolites. There was no inhibitory effect of NK-104 on CYP-mediated metabolism of taxol in human liver microsomes.

Virus-associated hemophagocytic syndrome due to rubella virus and varicella-zoster virus dual infection in patient with adult idiopathic thrombocytopenic purpura

A 26-year-old woman with idiopathic thrombocytopenic purpura (ITP) was admitted to our hospital because of fever and rash. Blood tests revealed thrombocytopenia, liver dysfunction, coagulopathy, and hyperferritinemia. Bone marrow examination revealed many atypical lymphocytes and some histiocytes with hemophagocytosis. On admission she was diagnosed with rubella virus-associated hemophagocytic syndrome (VHAS), but on laboratory examination, she was seropositive for varicella-zoster virus (VZV)-IgM as well as rubella virus-IgM. She was therefore diagnosed with dual infection by rubella virus and VZV. Her simultaneous rubella virus and VZV infection may have been related to the VAHS pathogenesis. She was treated with prednisolone and gamma globulin therapy and recovered completely.

FP prostanoid receptor activation of a T-cell factor/beta -catenin signaling pathway

FP prostanoid receptors are G-protein-coupled receptors (GPCR) that consist of two known isoforms, FP(A) and FP(B). These isoforms, which are generated by alternative mRNA splicing, are identical except for their carboxyl-terminal domains. Previously we have shown that stimulation of both isoforms with prostaglandin F(2alpha) (PGF(2alpha)) activates the small G-protein Rho, leading to morphological changes consisting of cell rounding and the formation of cell aggregates. Following the removal of PGF(2alpha), however, FP(A)-expressing cells show rapid reversal of cell rounding, whereas FP(B)-expressing cells do not. We now show that acute treatment of FP(B)-expressing cells with PGF(2alpha) leads to a subcellular reorganization of beta-catenin, a decrease in the phosphorylation of cytoplasmic beta-catenin, and persistent stimulation of Tcf/Lef-mediated transcriptional activation. This does not occur in FP(A)-expressing cells and may underlie the differences between these isoforms with respect to the reversal of cell rounding. The Tcf/beta-catenin signaling pathway is known to mediate the actions of Wnt acting through the heptahelical receptor, Frizzled, and has not been associated previously with GPCR activation. Our findings expand the signaling possibilities for GPCRs and suggest novel roles for FP receptors in normal tissue development and malignant transformation.

Bernard-Soulier syndrome associated with 22q11.2 microdeletion

We describe a Japanese girl with Bernard-Soulier syndrome and 22q11.2 microdeletion. She had viral infections and recurrent thrombocytopenia and hemorrhagic diathesis after cardiac surgery. As congenital heart defects and abnormal immunity are the most common clinical manifestations associated with 22q11.2 deletion, patients with this association may have a greater risk of developing a severe bleeding disorder.

Effects of intracoronary tissue-type plasminogen activator treatment in kawasaki disease and acute myocardial infarction

We retrospectively studied 3 patients with Kawasaki disease (KD) and acute myocardial infarction (AMI) who were treated with intracoronary administration of tissue-type plasminogen activator (t-PA). Two-dimensional echocardiogram on the next day of the treatment revealed reduction of thrombus and improvement of the cardiac function in all 3 patients. However, a 12-month-old patient treated with 200,000 U/kg of t-PA at 48 h after the onset of AMI died of recurrent myocardial infarction. The other 2 patients treated with 400,000 and 800,000 U/kg, respectively, showed clear, though not prompt, improvement in clinical symptoms and laboratory data. The intracoronary thrombolytic therapy using high-dose t-PA appears effective in treating AMI associated with KD.

Chemotherapy-induced unconjugated hyperbilirubinemia caused by a mutation of the bilirubin uridine-5'-diphosphate-glucuronosyltransferase gene

Chemotherapy for malignant neoplasms sometimes causes unconjugated hyperbilirubinemia in the absence of liver dysfunction. We analyzed the association of chemotherapy-induced hyperbilirubinemia with mutations of the bilirubin uridine-5'-diphosphate (UDP)-glucuronosyltransferase gene (UGT1A1) from two leukemic patients in whom chemotherapy resulted in a hyperbilirubinemic response. We isolated genomic DNA from peripheral blood samples and amplified UGT1A1 by polymerase chain reaction. The amplified DNA fragments were analyzed by direct sequencing. The genes of the two patients revealed an identical heterozygous missense mutation in exon 1 (211G-->A: G71R). This UGT1A1 mutation may be the basis of chemotherapy-induced unconjugated hyperbilirubinemia.