Quantitative analysis of the isthmo-optic nucleus (IO) and centrifugal projection to the retina in the fowl was made using Nissl preparation and retrograde horseradish peroxidase (HRP) methods. Seven adult fowls (Gallus gallus domesticus) were used for Nissl stain. Serial sections were cut on a freezing microtome at 60 microns and stained with cresyl violet. IO was situated just medial to the caudal part of the tectum and laterodorsal surface of the brain stem. Rostrocaudal extension of IO was about 800-1,000 microns. The average total volume and neuronal population of the IO was 280 x 10(-3) mm3 and 5,600 neurons, respectively. Eight animals were used for HRP study. One hundred microliters of 30% HRP solution in physiological saline was injected into the vitreous body of one eye of each hen. Serial transverse sections of 60 microns were treated with tetramethyl benzidine (TMB). Many labeled neurons were found in contralateral brain stem. Average total number of contralateral HRP-labeled cells in IO and peri-IO were 5,268 and 1,492, respectively. Labeled neurons peri-IO were mainly distributed ventrally and rostrally to IO. No labeled neurons in IO, and only a few labeled neurons peri-IO were found ipsilaterally. The number of HRP-labeled neurons in IO corresponded to the neuronal population of IO in Nissl preparation, which suggested that most of isthmo-optic neurons might be projecting to the contralateral retina. In contrast to the round and small IO neurons (long axis 15-20 microns, short axis 10-20 microns), peri-IO neurons were multipolar and longer (long axis 15-30 microns, short axis 10-25 microns).

Interleukin-11 (IL-11) is a novel cytokine that was identified in a medium conditioned by the primate bone marrow-derived stromal cell line PU-34. It was originally identified as a growth factor for the IL-6-dependent plasmacytoma cell line T1165. Adipogenesis inhibitory factor (AGIF) was cloned from the human bone marrow-derived cell line KM-102. The AGIF cDNA sequence was revealed to be identical to that of the IL-11 cDNA. AGIF inhibits the process of adipogenesis of the bone marrow-derived preadipocyte cell line H-1/A. Other biological activities of IL-11/AGIF, megakaryocytopoiesis, stem-cell proliferation, hepatic acute phase responses and antigen-specific antibody responses are also summarized.

Interleukin-9 (IL-9)/P40 is a recently reported murine growth factor for helper T-cell clones. It is produced by ConA stimulated CD4+ T-cells or several T-cell lines such as TUC 2.15 derived from C57Bl/6 mouse. In the murine system, IL-9/P40 directly supported proliferation of mucosal type mast cells, and also induced erythroid burst formation, indirectly. On the other hand, human IL-9, which is a homologue to murine P40, was cloned from a cDNA library prepared with mRNA isolated from PHA-induced T-cell line (C5MJ2). Analysis of the sequence of cDNA revealed a striking similarity between murine and human IL-9/P40. Human IL-9 supported formation of a subpopulation of erythroid bursts that are responsive to IL-3. In this communication, identification, cloning of cDNA, and biological activities of murine and human IL-9/P40 are discussed.

IL-5 is a T-cell-derived glycoprotein that acts on B cells and eosinophils to induce their growth and differentiation. We clarified using in vitro long-term bone marrow culture that IL-5 supports the growth and survival of Ly-1+ common progenitor cells which can differentiate into Ly-1+ B cells and Ly-1+ macrophages. The functional IL-5 receptor (IL-5R) consists of alpha and beta heterodimers. The 60 kDa alpha chain binds to IL-5 with low affinity, while the 130 kDa beta chain does not bind with IL-5 by itself, but converts low affinity IL-5R to high affinity IL-5R together with the alpha chain. The beta chain is shared with GM-CSFR and IL-3R.

Recent studies on the hematopoietic system have revealed that both constitutive and inducible hematopoiesis are regulated by complicated networks composed of various kinds of cytokines and that there are some general rules for hematopoietic cytokine biology. Further accumulation of knowledge about the regulation of proliferation and differentiation of hematopoietic cells by cytokines will serve to clarify the pathophysiology of hematological diseases, resulting in the development of therapeutic strategy for these diseases.

A 63-year-old man was admitted because of anemia and thrombocytopenia. The bone marrow was hypercellular with 66.6% erythroblasts with dysplasia and 19.8% blasts. Cytogenetically, MAKA (major karyotypic aberrations) containing 5q-, -7, -17, with karyotypic instability was observed. A diagnosis of erythroleukemia (FAB M6) was made. Six months later, immature neutrophils increased in the peripheral blood, and blasts and promyelocytes increased to 25.8% and 20.0% of marrow cells, respectively. Three months later, blasts asts increased to 33.0% in the peripheral blood. They were ultrastructually positive for platelet peroxidase. Phenotypically, 69% and 63% of blasts were positive for CD41b (GPIIb/IIIa) and CD42a (GPIb), respectively. Bone marrow biopsy showed marked proliferation of blasts and dysplastic megakaryocytes accompanied by reticulin fibrosis. These findings suggested evolution to megakaryoblastic leukemia (FAB M7). In most cases, M6 defined by the FAB criteria is stem cell disorder with multilineage involvement and major erythroid component. M6-like features may be observed in the evolutive phase to acute leukemia from myelodysplastic syndrome (MDS).

Erythroid differentiation factor (EDF), initially found as a differentiation inducer of murine erythroleukemia cells, also acts on normal erythroid progenitors in vitro and in vivo. Furthermore, it is produced endogenously and supporting in vivo erythropoiesis. EDF is structurally identical to activin A, a gonadal protein with follicle stimulating hormone releasing activity, and belongs to TGF beta superfamily. Its activity could be regulated by follistatin, a binding protein with neutralizing activity against EDF/activin A. Molecular cloning of EDF/activin A receptor cDNA has revealed its domain structure characteristic to serine/threonine kinase.

Mice of genotype W/Wv and Sl/Sld have been considered as a model of instinct hemopoietic disorders. W/Wv mice have a defect in hemopoietic stem cells and Sl/Sld mice have a defect in the microenvironment. The W locus in murine chromosome 5 encodes the c-kit proto-oncogene and the Sl locus in chromosome 10 encodes the ligand for c-kit, which has been named stem cell factor (SCF), mast cell growth factor (MGF), kit ligand (KL) and steel factor (SL). The cDNA sequence of SCF suggest that it is synthesized as an integral transmembrane protein and that it has common tertiary structure with M-CSF. SCF enhances the proliferation of hemopoietic stem cells and progenitor cells as well as mast cell in combination with other growth factors. Furthermore, it plays an important role in the proliferation and migration of embryonic stem cell, primordial germ cell and melanocyte.

Human granulocyte colony-stimulating factor, a 19KD glycoprotein consisting of 174 amino acids, is one of the physiological regulators mainly produced by monocytes-macrophages, fibroblasts, and endothelial cells, under various stimulations such as neutropenias and infections. The molecule specifically and markedly stimulates the production of neutrophils associated with an expansion of the hemopoietic stem cells/progenitor cells, proliferates myeloid leukemia cells, releases these cells into blood, and elevates the functional activities of neutrophils. Under the favor of the activities, recombinant human granulocyte colony-stimulating factor has now become an epoch-making agents for the treatment of various disorders.

Receptors for immuno-hematopoietic cytokines are multi-chain complexes of membrane proteins. Molecular cloning of these cytokine receptor genes revealed the existence of a here-to-fore unidentified receptor superfamily. They are primarily characterized by a shared extracellular structure that may be involved in the formation of multi-chain receptor complex. Inspite of the lack of any catalytic function, several members of the superfamily are known to act as the transmembrane transducers of cytokine signals. Such molecules may interact physiologically/functionally with multiple intracellular catalytic molecules to generate signals. In this regard, potential involvement of protein tyrosine kinase and protein serine/threonine kinase in the post-receptor signalling has been described. Dysregulated activation of the cytokine receptor gives rise to transformation of immuno-hematopoietic cells.

The retinoblastoma susceptibility gene (RB) is expressed in all lineages of normal hematopoietic cells and plays an important role in controlling cell cycle progression at G1/S. Abnormalities of the RB gene may, therefore, predispose to the development of hematologic malignancies. DNA rearrangement was reported to be present in 1.5-12.1% of cases with primary leukemias and the absence of the RB gene product was also observed in 6.3-23.2%. The abnormalities were frequently observed in blastic crisis of CML, especially of the megakaryoblastic phenotype, AML with monocytic differentiation and Ph1-positive leukemias. These results indicate that abnormalities of RB are relatively common in hematologic malignancies and loss of RB function may contribute to the altered growth of these cells.

Recently developed third generation chemotherapy programs have improved long-term disease free survival of patients with non-Hodgkin's lymphoma of aggressive histology, as compared with their predecessors. These protocols have been developed based on the cancer chemotherapy principles derived mainly of experimental tumor studies by H. Skipper and his group, and the theoretical approach by Goldie and Coldman to the occurrence of and chemotherapeutic overcoming of resistant clones. They are characterized by the use of multiple non-cross-resistant drugs in maximally elevated dose intensity. Our third generation protocol, CAMBO-VIP, has produced 90% CR and 76% DFS at 3 years. Further improvement may be obtained by application of new drugs with different mechanism of action, effective means to destruct resistant cells, and further elevation of dose intensity by myelostimmulatory cytokines or transplantation of autologous/allogeneic peripheral blood or bone marrow stem cells.

After the discovery of the effect of vitamin D on cell differentiation by Abe, Suda and their colleagues, it has become clear that many of the vitamin D actions are mediated by their effect on terminal differentiation of various cells. Similarly important are the findings that the vitamin D receptors are almost ubiquitously distributed in various tissues, and the active metabolite of vitamin D exerts its effects in almost all types of cells. Thus, the actions of vitamin D are not confined to their classical target tissues that regulate calcium metabolism, but also are extended to the regulation of the proliferation and differentiation of various cells such as immunoregulatory cells, epidermal cells and malignant tumor cells. These discoveries have created a new era in the field of vitamin D endocrinology, and led to the development of vitamin D analogues that exert their effects mostly in the nonclassical target tissues with little effects on calcium metabolism. Efforts are currently under way to apply these analogues to the treatment of various disturbances such as immunological disorders, skin lesions and malignant tumors. This review briefly summarizes the current understandings on the effect of vitamin D on cell differentiation and proliferation, and discusses the future prospects of the application of these effects on the treatment of various disorders.

Microscopic analysis of bone marrow smears from ten untreated patients with multiple myeloma (MM) revealed that seven patients had myelodysplastic changes. Of these, five patients had anemia alone while the other two had anemia and leucopenia. The myelodysplastic changes seen in MM were less extensive than those seen in myelodysplastic syndrome (MDS). Moreover, the dysplastic changes in MM were determined to be limited to two or three lineage cells. Dysplastic changes were observed even after clinical signs of MM had improved due to therapy. We consider that the myelodysplastic changes seen in MM can be attributed to MM itself, rather than to the coexistence of MDS and MM. Such findings suggest that the pathogenesis of MM involves a common stem cell which differentiates into multiple lineage cells.

A 47-year-old woman with myasthenia gravis for last 11 years was admitted because of relapsed muscle weakness, hypermenorrhea and thrombocytopenia. Physical and neurological examinations revealed diplopia, proximal muscle weakness and purpuras on the left arm and bilateral legs. Repeated hematological examinations revealed cyclic fluctuation of platelet counts which spontaneously changed from the nadir levels of 12-27 x 10(3)/microliters to the peak levels of 150-400 x 10(3)/microliters. The platelet count reached a nadir at the onset of menstruation. Platelet-associated IgG (PAIgG) was within normal level when platelet count was at an increasing phase. Survival time of autologous platelets was normal when platelet count was at an increasing phase. Megakaryocytes in the bone marrow were apparently normal at the nadir phase. The patient's serum obtained at the nadir of platelet count significantly suppressed megakaryocyte colony forming unit (Meg-CFU) formation in comparison with that after the stabilization of platelet count, suggesting that this cyclic thrombocytopenia was secondary to cyclic hypoproduction of megakaryocytes caused by a suppressive factor. On the other hand muscle weakness showed no cyclic fluctuation. Administration of 60 mg/day prednisolone stabilized the platelet count at about 280 x 10(3)/microliters, abolished hypermenorrhea and gradually improved muscle weakness. These findings suggested autoimmune mechanism in the production of a Meg-CFU-suppressive factor might be involved in the pathogenesis of thrombocytopenia.

Four pedigrees of Machado-Joseph disease (MJD) were reported. Main clinical features of 21 patients in these pedigrees were cerebellar ataxia, limb spasticity, gaze nystagmus, facio-lingual twitchings, and external ophthalmoparesis. Amyotrophy, hypokinesia, or dystonia were manifested with advance of the illness. In patients with younger onset age, such extrapyramidal signs were dominated. Neuropathological study of one autopsied case disclosed that there were degeneration of spinocerebellar tract, anterior horn cells, pontine nuclei, dentate nucleus, red nucleus, substantia nigra, internal segment of globus pallidus, subthalamic nucleus, and motor nuclei of brain stem; neurons of cerebellar cortex and inferior olivary nucleus were preserved. From these clinical and pathological features, these 4 pedigrees satisfied the criteria of MJD, and were differentiated from hereditary olivopontocerebellar atrophy. Currently, MJD is accepted as a new entity of hereditary spinocerebellar ataxias. However, there are still controversies as to whether Azores-Portuguese MJD and Japanese MJD are identical disorder. Furthermore, the nosological relationship between MJD and a number of similar cases, as reported historically under the diagnosis of Brown type ataxia or Marie's ataxia, has not been clearly established. From reviewing such cases critically, pathological and clinical features of our cases are so similar to those of the latter, indicating that the probably identical genetic disorder has been classified under the different categories.