Paroxysmal Nocturnal Hemoglobinuria (PNH) is an acquired hemolytic anemia characterized by chronic hemolysis, deep thrombosis, and hypoplastic marrow, and thought to be a clonal hematopoietic stem cell disorder. Affected blood cells are deficient in glycosylphosphatidylinositol (GPI)-anchored cell surface proteins. Recent investigations revealed that the PIG-A gene, which participates the biosynthesis of the GPI-anchor, was identified and the mutations were detected in the patients with PNH. Here we discuss the following problems related to the PIG-A gene; (1) the inconsistency of the expression of the GPI-anchored proteins and the mutations of the PIG-A gene, (2) the existence of the multiple PNH clones bearing different PIG-A mutations in a single patient, (3) aplastic anemia-PNH syndrome and PIG-A gene.

Aqueous extracts prepared from the murine kidney (MKE) promoted colony formation derived from murine hematopoietic progenitor cells in serum-free cultures stimulated by interleukin-3 (IL-3) and erythropoietin (Epo). MKE itself did not stimulate any colony formation. MKE preferentially enhanced granulocyte-macrophage colony forming units (CFU-GM), but did not promote any erythroid colony formation. The CFU-GM colony promotion by MKE was observed at day 6 after the culture started, and the colony-promoting activity (CPA) was maintained at the same level until day 16. MKE showed no CPA in the cultures using cells obtained from 5-FU-injected mice and from c-kit(+)-enriched treatment. Furthermore, MKE acted synergistically with granulocyte-colony-stimulating factor (CSF), macrophage-CSF, IL-6 and IL-11 on colony formation, but did not act with GM-CSF, stem cell factor and Epo. From the results of various experiments and gel-filtration chromatography, it is estimated that the colony-promoting factor detected in MKE is a heat stable protein with about 20 KDa molecular weight. These results suggest that MKE promotes colony formation by murine myeloid progenitor cells, and that the target cell populations of MKE are relatively mature in the hematopoietic differentiation pathway.

In this review, I have attempted to provide an overview of the pathways by which cytotoxic drugs induce emesis. The mechanisms of serotonin 5-HT3 antagonists and new antiemetics are also discussed. Old data especially from the experiments employing area postrema ablation must be re-evaluated because it is likely that the operation has damaged other important nucleus in the brain stem. Therefore, the concept of the chemoreceptor trigger zone and "vomiting center" proposed by Borison et al. in 1950s is questionable. Nausea and vomiting caused by cytotoxic drugs have been a serious problem in anti-cancer therapy and prompted lots of scientists to find the mechanism and to develop antiemetics. Effectiveness of 5-HT3 antagonists were shown in late 1980s, and now they are clinically available. I have investigated their mechanisms using Suncus murinus and proposed that the pathways by which cisplatin, one of most emetogenic drugs, induces emesis are as follows: 1) cisplatin is converted to an active metabolite(s), 2) the metabolite(s) somehow produces oxygen free radicals in the enterochromaffin cells, 3) the free radicals release serotonin, 4) the released serotonin stimulates 5-HT3 receptors located on the vagus afferents, 5) impulses are transmitted to the brain stem, or emetic pattern generator and initiate emetic reflex. Therefore, scavengers of free radicals and antioxidants can be a new type of antiemetic drug.

A 49-year-old woman who suffered from caecal cancer in 1988 underwent chemohyperthermic peritoneal perfusion for peritoneal and ovarian metastases in 1990, and high dose chemotherapy (HDC) with peripheral blood stem cell transplantation (PBSCT) for lung metastases in 1995. Heated saline containing anticancer drugs such as cisplatin, mitomycin C, etoposide (ETP), and pirarubicin, was intraperitoneally perfused at 43 degrees C for 60 minutes. The CD34 positive cells were mobilized by intravenous 500 micrograms G-CSF administration on five consecutive days. These cells were transplanted three days after the last day in the course of HDC, which included intravenous administration of 475 mg carboplatin, 2,020 mg cyclophosphamide, and 540 mg etoposide. The patient has survived with no sign of the disease.

There have been several advances in our understanding and management of multiple myeloma (MM). Firstly, somatic mutations without intraclonal variation have been detected in Ig genes of malignant plasma cells, indicating that the major oncogenic events yielding continuous proliferation of the myeloma stem cell occur in a cell selected by contact with antigen in the lymphoid follicles. Secondly, interleukin-6 supplied by autocrine and paracrine secretion has been identified as a major cytokine for the emergence of the tumor clone. Thirdly, myeloablative chemoradiotherapy with autologous peripheral blood stem cell rescue has been shown to induce complete remission and to improve prognosis, although disappointingly few patients benefit from it. An improved strategy, such as anti IL-6 and/or anti IL-6R administration with biological therapy directed to suppress the myeloma cell growth is necessary as rational therapy.

In a prospective randomized trial conducted by SWOG, CHOP has shown equivalent efficacy to second and third generation combinations, while the toxic death rate by CHOP was the smallest among regimens studied. The group thus concluded that CHOP remains the best available treatment. However judging from past results it is not definitive that CHOP is standard. Many investigators therefore have studied to obtain higher efficacy than by CHOP. Regimens for higher dose intensity with the support of G-CSF, and high dose chemotherapy with the support of autologous hematopoietic stem cells, are under way and current results are reviewed.

Cisplatin-based conventional chemotherapy followed by surgery can cure 80-70% of disseminated testicular cancers. Effective salvage therapy is required for the remaining 20-30% of patients. High-dose chemotherapy (HDCT) combined with autologous stem-cell rescue for refractory testicular tumor results in about 10-20% durable complete responses. Hematologic toxicity is severe, and about 10% treatment-related deaths were reported in early investigations. Early salvage therapy or first-line therapy using HDCT is under investigation to improve treatment efficacy of the refractory or poor-risk testicular cancer. One of the important findings of these trials is that a platinum analogue may be critical to HDCT for cisplatin-refractory cases. Recent basic research has showed that platinum-containing anticancer drug provokes a complex response in the cancer cells. It is hoped that investigation of the mechanism of cisplatin-resistance or development of a new platinum complex will overcome the limitations of salvage chemotherapy for this disease. Finally, several investigators reported that highly selected chemorefractory patients, even with positive tumor markers, have definite potential for cure with surgical resection of localized metastatic disease. Thus, salvage surgery may be indicated for patients refractory to all potentially curative chemotherapeutic regimens.

We examined the endonuclease activity capable of inducing internucleosomal DNA fragmentation in hematopoietic cells. Mg(2+)-dependent nuclease activity was high in hematopoietic progenitor cells and the activity decreased with myeloid or erythroid differentiation. This was the case in MDS as well as in normal hematopoiesis. In contrast, Ca2+/Mg(2+)-dependent nuclease activity varied widely in the samples from MDS and the possibility was indicated that the activity of Glycophorin A+ cells was related to the degree of anemia. We also investigated DNA strand breaks in bone marrow samples from 16 patients with MDS and 10 with other diseases by an in situ end labeling (ISEL) technique. The reactivity in ISEL tended to increase parallel to disease progression of MDS. The high ISEL-positivity was also observed in some samples from patients with MPD and other diseases. Though ISEL is a useful technique for quantification of apoptosis, our results suggested that MDS cells with ISEL positive staining are not necessarily in the process of apoptosis.

Little is known how Extra cellular matrix (ECM) molecules regulate proliferation of human hematopoietic progenitor cells. Fibronectin (FN) strikingly inhibited a human growth factor dependent cell line, M07E, cell proliferation. DNA content analysis revealed that FN treatment resulted in the appearance of subdiploid peak. Furthermore, FN induced oligonucleosomal DNA fragmentation and chromatin condensation, suggesting the involvement of apoptosis in the FN induced growth suppression. The apoptosis was rescued by anti-VLA5 mAb and the FN-induced apoptosis was detectable only VLA5-positive human cell lines but not in any of the VLA5-negative cell lines. These results suggest that FN induces apoptosis via its interaction with VLA5, and also raise the possibility that the FN-VLA5 interaction may contribute to negative regulation of hematopoiesis.

It is clear that cytokines regulate normal hematopoiesis including proliferation, differentiation, and apoptosis (programmed cell death). Leukemia is a disorder of unbalance between excessive proliferation and inappropriate apoptosis. Leukemic cells are also stimulated by cytokines similar to normal hematopoietic cells. It is reported that the oncogenes and tumor suppressor genes are associated with not only leukemogenesis but also cell cycle, for example proliferation, differentiation, and apoptosis (programmed cell death). We found that G-CSF leads to apoptosis of radiation induced murine leukemia cell line (C2M-A5), and its apoptosis is dependent on cell cycle. From these results together with other related reports, cytokines seem to be a key substance of apoptosis of leukemic cells and the apoptosis inducing therapy will be a new strategy for leukemia therapy.

We investigated the expression of Fas(CD95) on hematopoietic progenitor cells. CD34+ cells freshly isolated from bone marrow did not express Fas. However, interferon-gamma(IFN-gamma) and/or tumor necrosis factor-alpha (TNF-alpha) induced the expression of Fas after 48 hours of serum-free culture. The TNF-alpha-induced Fas expression is mediated by p55-TNF-alpha receptor. Human CD34+ cells expressed Fas following low dose ionizing radiation in a dose-dependent fashion. CD34+ cells isolated from bone marrow were cultured with hematopoietic growth factors for 7 days. CD34+ cells cultured with hematopoietic growth factors gradually became positive for Fas and rapidly lost Bcl-2 expression. Fas system is considered to play important roles at the level of hematopoietic progenitor cells in both physiologic and pathologic conditions.

A 28-year-old male presented with a low grade fever, decreased activity, left hemiparesis and signs of intracranial hypertension. CT showed a moderate hydrocephalus and a large irregular mass in the right temporoparietal region with garland-like enhancement after injection of the contract medium. These findings suggested a malignant brain tumor. MR images demonstrated a mass with low-iso signal intensity on T1 weighted image and low-iso-high mixed intensity on T2, which is like a mosaic pattern. Multiple cerebrospinal fluid space seedings including the wall of the lateral ventricle, the surface of the cerebellum and pons, and the cervical spinal cord were clearly delineated on MR images after Gd-DTPA injection. The large mass was totally removed by craniotomy after ventricle drainage for hydrocephalus. Microscopic examinations showed dense fibrous connective tissue with infiltration of Langhans' giant cells, lymphocytes and fibroblasts around the necrotic centers. These hard components may have been responsible for the low signal intensity on T2-MR images. Many Candida elements were clearly shown with the periodic acid Schiff stain. The diagnosis was that the lesion was an intraparenchymal granuloma due to Candida infection. The patient died on the 8th postoperative day because of brain stem malfunction. Intracranial fungal infection rarely produces a granuloma in the central nervous system. Though it is difficult to diagnose a large irregular mass in the brain, MR images, especially T2 weighted images are useful for the diagnosis of fungal granuloma.

This paper reviewed recent progress in analyses of gut function by the aid of molecular biology. Particularly noted were 1) involvement of immediate early genes in mucosal epithelial proliferation in vitro and in ulcer healing in rat stomach in vivo; and 2) possible involvement of c-kit/stem cell factor, endothelin-receptor B, endothelin-3 and ret in regulation of gut motility and Hirschsprung's disease. These cases show that molecular biology, together with novel approaches through medical engineering, significantly expands our knowledge on regulation of gut functions.