4-(1-benzoylindol-3-yl)butyric acids and FK143: novel nonsteroidal inhibitors of steroid 5 alpha-reductase (II)

A novel series of indolebutyric acids with varying benzoyl substituents were synthesized to develop nonsteroidal inhibitors of steroid 5 alpha-reductase. We previously reported the discovery of a novel nonsteroidal 5 alpha-reductase inhibitor, FR119680, which had an IC50 value of 5.0 nM against the rat prostatic enzyme. However, this compound was not strongly active against the human prostatic enzyme. By further study of the structure-activity relationships we succeeded in producing the strongly active compound, FK143, 4-[3-[3-[bis(4-isobutylphenyl)-methylamino]benzoyl]-1H-indol-1-yl] butyric acid, with an IC50 value of 1.9 nM against the human enzyme. FK143 also has in vivo inhibitory activity against the castrated young rat model and it should therefore be an extremely useful agent for the treatment of benign prostatic hyperplasia.

Molecular cloning of cDNA encoding human Rab3D whose expression is upregulated with myeloid differentiation

To identify genes expressed in myeloid differentiation, we isolated a cDNA fragment by differential display using RNA prepared from HT93A cells, a human cell line capable of differentiating into neutrophil and eosinophil lineages in response to retinoic acid (RA). Evaluation of the full-length clone isolated from an HT93A cDNA library showed that it encoded a 24 kDa protein comprised of several domains conserved in the Ras superfamily. Comparison of the deduced amino acid sequence of this clone with Rab proteins revealed that it had highest homology to a small GTP-binding protein, murine Rab3D. The mRNA expression of human Rab3D was upregulated in the course of myeloid differentiation, and it was preferentially expressed in granulocytes. These results suggest that human Rab3D may play a specific role in granulocytes, for example in exocytosis of neutrophil-specific granules or in degranulation of both eosinophils and basophils.

Abnormal distribution of hippocampal mossy fibers in rats exposed to X-irradiation in utero

The effects of prenatal X-irradiation (0.3, 0.6, 1.2 or 1.8 Gy) on the hippocampal development were examined at six weeks of age in rats. The laminar structure of the hippocampus was deranged in the rats exposed to 0.6 Gy or more. Pyramidal cells in the CA-3 region were more susceptible than those in the CA-1 region. Aberrant mossy fiber terminals were observed in the stratum oriens of the CA-3 region (infrapyramidal mossy fibers) in rats exposed to 0.3 Gy or more.

Effect of leukocytapheresis therapy using a leukocyte removal filter in Crohn's disease

Eighteen patients with active Crohn's disease were treated with one leukocytapheresis session per week for a five-week intensive therapy, decreasing to one leukocytapheresis session per month for five sessions of initial maintenance therapy. Nutritional indices, inflammatory reactions, flow cytometry profiles, and cytokine production were also assessed before and after the intensive and initial maintenance therapy. Nine of the patients (50%) attained remission at the end of the intensive therapy. The nine non-remission patients had exhibited longer periods of suffering and more severely affected sites prior to the therapy. In 14 of 18 patients (77.8%), the nutritional indices, Internal Organization of Inflammatory Bowel Disease (IOIBD) score and Crohn's Disease Activity Index (CDAI) improved from the pretherapy levels, but only the remission group (50%) showed improvement in C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR). The remission group showed significantly higher pretherapy CD4+ CD45+ cell ratios and interleukin-2 (IL-2) production than the non-remission group, and significantly lower activated cells.

Serum levels of thyroid-stimulating hormone receptor antibodies during IFN-alpha2a treatment of chronic hepatitis C

Twenty chronic hepatitis C patients with baseline levels of thyroid hormones, antithyroglobulin, and antimicrosomal antibodies within the normal range were monitored by thyroid testing during a 26-week treatment with interferon-alpha2a (IFN-alpha2a). The present study was aimed at retrospectively analyzing thyroid-stimulating hormone (TSH) receptor antibodies, employing stored serum samples obtained from these patients at baseline, at 12 weeks, and at the end of IFN-alpha2a treatment. Ten patients (group A) received IFN-alpha2a at a total dose of 474 million units (MU), and 10 patients (group B) at a total dose of 774 MU. None of the patients produced antithyroglobulin and antimicrosomal antibodies. Two patients in group A exhibited elevated TSH levels without free thyroid hormone alterations while on the treatment. At baseline, 1 patient in group A had a positive TSH binding inhibitory immunoglobulin, and 1 patient in group B was positive for thyroid-stimulating antibody at the end of treatment. Both patients remained euthyroid throughout the treatment. Treatment with IFN-alpha2a may infrequently induce the production of TSH receptor antibodies in chronic hepatitis C patients provided preexisting autoimmune thyroid disease is precluded.

Beta2-glycoprotein I is necessary to inhibit protein C activity by monoclonal anticardiolipin antibodies

OBJECTIVE

To clarify mechanisms of the thrombosis associated with anticardiolipin antibodies (aCL), we examined the effects on activated protein C (APC) of monoclonal aCL and beta2-glycoprotein I (beta2GPI), which is required for formation of the epitopes of aCL.

METHODS

We developed the chromogenic assay, in which the degradation of coagulation factor Va by APC is reflected in the reduced generation of thrombin from prothrombin, using soybean trypsin inhibitor to inhibit APC. APC activities were measured in the presence and absence of 3.4 microM beta2GPI and/or 2.5 microg/ml of IgM monoclonal aCL (EY2C9 and EY1C8) established from peripheral blood lymphocytes obtained from a patient with aCL.

RESULTS

Without APC, the formed thrombin activity decreased by the addition of 3.4 microM beta2GPI. When 12.8 nM APC was added, beta2GPI partially reversed the APC-induced inhibition of thrombin generation in a concentration-dependent manner. With 3.4 microM beta2GPI, the thrombin generation in monoclonal aCL (2.5 microg/ml) decreased to 77.1-80.2% by the addition of 12.8 nM APC, but the values were above that in the control IgM (72.7%). Without beta2GPI, the APC activity was unaffected by the addition of monoclonal aCL.

CONCLUSION

Beta2-glycoprotein I exhibits procoagulant activity by inhibiting APC activity and anticoagulant activity by inhibiting thrombin generation. Any further inhibition of APC activity was caused by monoclonal aCL and only in the presence of beta2GPI.

Role of physiologic concentrations of stem cell factor in leukemic type growth of myelodysplastic CD34+ cells

The stem cell factor (SCF: a ligand for c-kit) plays a central role in the growth of myelodysplastic (MDS) progenitor cells with leukemic type growth. In this study, the role of physiologic concentrations of SCF on the proliferation and differentiation on MDS progenitor cells was further analyzed in the presence of combined cytokines. For this purpose, marrow CD34+ cells were purified up to 94% for 12 normal individuals and 90% for 18 MDS patients, using monoclonal antibodies and immunomagnetic microspheres. The purified CD34+ cells were cultured for 14 days with saturating doses of cytokines, including recombinant human macrophage colony stimulating factor (rM-CSF), granulocyte-CSF (rG-CSF), granulocyte/macrophage-CSF (rGM-CSF), interleukin-3 (rIL-3) and rSCF. The clonal growth of MDS CD34+ cells supported by a combination of all the above cytokines was then subdivided into the two patterns of leukemic or non-leukemic. The role of various concentrations of rSCF (0, 0.5, 5, 50 and 500 ng ml(-1)), with or without the above cytokines, in proliferation and differentiation of MDS CD34+ cells was analyzed in each group. The physiologic concentration of SCF at 5 ng ml(-1) significantly increased undifferentiated 'blast cell' colonies or clusters in leukemic type growth of MDS CD34+ cells over that seen in normal CD34+ cells. SCF is present in plasma at a level of ng ml(-1). This means that progenitor cells are continuously exposed to stimulation by SCF in vivo and that MDS leukemic cells have a growth advantage over normal blasts.

Characterization of biosynthetic enzymes for ectoine as a compatible solute in a moderately halophilic eubacterium, Halomonas elongata

1,4,5,6-Tetrahydro-2-methyl-4-pyrimidinecarboxylic acid (ectoine) is an excellent osmoprotectant. The biosynthetic pathway of ectoine from aspartic beta-semialdehyde (ASA), in Halomonas elongata, was elucidated by purification and characterization of each enzyme involved. 2,4-Diaminobutyrate (DABA) aminotransferase catalyzed reversively the first step of the pathway, conversion of ASA to DABA by transamination with L-glutamate. This enzyme required pyridoxal 5'-phosphate and potassium ions for its activity and stability. The gel filtration estimated an apparent molecular mass of 260 kDa, whereas molecular mass measured by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) was 44 kDa. This enzyme exhibited an optimum pH of 8.6 and an optimum temperature of 25 degreesC and had Kms of 9.1 mM for L-glutamate and 4.5 mM for DL-ASA. DABA acetyltransferase catalyzed acetylation of DABA to gamma-N-acetyl-alpha,gamma-diaminobutyric acid (ADABA) with acetyl coenzyme A and exhibited an optimum pH of 8.2 and an optimum temperature of 20 degreesC in the presence of 0.4 M NaCl. The molecular mass was 45 kDa by gel filtration. Ectoine synthase catalyzed circularization of ADABA to ectoine and exhibited an optimum pH of 8.5 to 9.0 and an optimum temperature of 15 degreesC in the presence of 0.5 M NaCl. This enzyme had an apparent molecular mass of 19 kDa by SDS-PAGE and a Km of 8.4 mM in the presence of 0. 77 M NaCl. DABA acetyltransferase and ectoine synthase were stabilized in the presence of NaCl (>2 M) and DABA (100 mM) at temperatures below 30 degreesC.

Single tottering mutations responsible for the neuropathic phenotype of the P-type calcium channel

Recent genetic and molecular biological analyses have revealed many forms of inherited channelopathies. Homozygous ataxic mice, tottering (tg) and leaner (tgla) mice, have mutations in the P/Q-type Ca2+ channel alpha1A subunit gene. Although their clinical phenotypes, histological changes, and locations of gene mutations are known, it remains unclear what phenotypes the mutant Ca2+ channels manifest, or whether the altered channel properties are the primary consequence of the mutations. To address these questions, we have characterized the electrophysiological properties of Ca2+ channels in cerebellar Purkinje cells, where the P-type is the dominant Ca2+ channel, dissociated from the normal, tg, and tgla mice, and compared them with the properties of the wild-type and mutant alpha1A channels recombinantly expressed with the alpha2 and beta subunits in baby hamster kidney cells. The most striking feature of Ca2+ channel currents of mutant Purkinje cells was a marked reduction in current density, being reduced to approximately 60 and approximately 40% of control in tg and tgla mice, respectively, without changes of cell size. The Ca2+ channel currents in the tg Purkinje cells showed a relative increase in non-inactivating component in voltage-dependent inactivation. Besides the same change, those of the tgla mice showed a more distinct change in voltage dependence of activation and inactivation, being shifted in the depolarizing direction by approximately 10 mV, with a broader voltage dependence of inactivation. In the recombinant expression system, the tg channel with a missense mutation (P601L) and one form of the two possible tgla aberrant splicing products, tgla (short) channel, showed a significant reduction in current density, while the other form of the tgla channels, tgla (long), had a current density comparable to the normal control. On the other hand, the shift in voltage dependence of activation and inactivation was observed only for the tgla (long) channel. Comparison of properties of the native and recombinant mutant channels suggests that single tottering mutations are directly responsible for the neuropathic phenotypes of reduction in current density and deviations in gating behavior, which lead to neuronal death and cerebellar atrophy.

Hematopoietic cytokine levels and in vitro colony formation assay in fetal anemia

Fetal anemia causes hydrops fetalis and fetal ascites/hydrothorax, and in severe cases the prognosis is poor. Little other than alloimmunity and viral infections are known as mechanisms causing fetal anemia. The aim of this study was to elucidate any pathogenesis in fetal anemia due to otherwise idiopathic etiology. The levels of three hematopoietic cytokines, IL-3, erythropoietin (EPO), and granulocyte colony-stimulating factor (G-CSF) were measured in blood samples obtained by cordocentesis from six fetuses with anemia (Hb <10.0 g/dl) and 34 fetuses without anemia. Cordocentesis was performed prior to the onset of labor or uterine contractions in all pregnant women. The concentration of IL-3 in fetuses with anemia [M+/-(SD), 8.3 (10.1) pg/ml] was significantly lower than that in fetuses without anemia [59.9 (71.0) pg/ml]. EPO and G-CSF levels were not different between the two groups. In addition, through in vitro colony formation assay, using blood stem cells from two fetuses with severe anemia and three fetuses without anemia, it was found that colony forming unit-erythroid, burst forming unit-erythroid and granulocyte macrophage-colony forming unit were significantly suppressed in blood stem cells from the two fetuses with severe anemia. Thus, the malfunction of differentiation and proliferation of blood stem cells and the decrease of hematopoietic cytokine levels in the fetal circulation may be responsible for the occurrence of fetal anemia.

Recurrence with histological transformation 40 days after autologous peripheral blood stem cell transplantation (APBSCT) for cutaneous CD30-negative large T cell lymphoma

Localized cutaneous nontender nodules appeared on the back of a 52-year-old Japanese woman. Skin biopsy revealed atypical large T-lymphocytes infiltrating the dermis. CD30 staining was negative in tumor cells. The diagnosis was CD30-negative cutaneous large T cell lymphoma. There was no evidence of peripheral lymphadenopathy or bone marrow involvement. Six cycles of induction chemotherapy were administered and a complete clinical remission (CCR) was attained. Local irradiation was not given. As the clinical course of CD30-negative cutaneous large T cell lymphoma is recurrent and often incurable with conventional chemoradiotherapy, she received high-dose chemotherapy without total body irradiation (TBI) followed by unpurged autologous peripheral blood stem cell transplantation (APBSCT). A relapse in the skin followed 40 days after APBSCT, but tumor cells transformed into a CD30-positive anaplastic large cell lymphoma (ALCL). We question the need for TBI in conditioning and for purged stem cells for APBSCT in patients with high risk cutaneous lymphomas.

[Experience of cancer home chemotherapy with cooperation between hospital and clinic]

Cancer home chemotherapy has improved through the cooperation between hospital and clinic. We have experienced cancer home chemotherapy in 90 cases of terminal cancer from August 1990 to May 1998. Patients had received Low-dose infusions of 5-FU and CDDP during 6-7 days using an implanted reservoir and balloon-style continuous infusor. This therapy was continued for about several months to 2 years. We chose one method from among central venous infusion, subselective aortal infusion, selective arterial infusion, and combination of these types of infusion. The role of the hospital includes reduction operations and operations involving implant systems. When these are finished, patients are discharged from hospital and introduced to the clinic as quickly as possible. On the other hand, the clinic should care for implanted infusion system, prevent side effects, and care for patient's general condition. Side effects due to drug overdose must especially be prevented. This time, we have examined the respective roles of the hospital and clinic, some mutual problems, along with medical costs and insurance.

(1-Benzylindole-3-yl)alkanoic acids; novel nonsteroidal inhibitors of steroid 5 alpha-reductase (I)

A novel series of indole-3-alkanoic acids with varied N-benzyl substituents were synthesized as nonsteroidal inhibitors of steroid 5 alpha-reductase. The structure-activity relationships in this series were studied and the optimum carboxylic acid side chain was butyric acid. Furthermore, compounds with a diaryl substituent at the 1-position of the indole ring displayed strong inhibitory activities in vitro. Amongst these derivatives, 4-[1-(6,6-dimethyl-6H-dibenzo[b,d]pyran-3-yl)methylindol-3-yl]b uty ric acid (FR119680) displayed very high inhibitory activity in vitro against rat prostatic 5 alpha-reductase (IC50 = 5.0 nM) and good in vivo activity in the castrated young rat model.

In vitro expansion of CD34+/CD41+ cells from human peripheral blood CD34+/CD41- cells: role of cytokines for in vitro proliferation and differentiation of megakaryocytic progenitors

The aim of this study is to clarify the transitional change of the proliferation and differentiation of human peripheral blood CD34+ cells to megakaryocytic lineage, focusing on its clinical application. We developed a rapid system to purify human peripheral blood CD34+ cells from healthy volunteers, which produced CD34+ cells with a 90% purity. The purified CD34+ cells predominantly consisted of CD41- cells, and the rate of coexpression of CD41 was 0.6% +/- 0.5%. When the purified cells were cultured in liquid phase for 10 days in the presence of recombinant human stem cell factor (rSCF: a ligand for c-kit), interleukin-3 (rIL-3), and thrombopoietin (rTPO: a ligand for Mpl), the number of CD34+/CD41+ cells increased to 19% +/- 7% of total expanded cells on day 4 (4 days of liquid culture) and then gradually decreased to 2.2% +/- 0.6% on day 10. The absolute number of CD34+/CD41+ cells increased and reached a plateau on day 6, and 1.7 +/- 0.6 x 10(5) CD34+/CD41+ cells were produced by 1 x 10(5) CD34+/CD41- day 0 cells. The CD34-/CD41+ cells appeared on day 6, continuously increased in number until day 10, and constituted the main population of expanded cells on day 10, with a value of 38% +/- 18%. On day 10, 19.5 +/- 10.6 x 10(5) of CD34-/CD41+ cells were produced by 1 x 10(5) CD34+/CD41- day 0 cells. The deletion of rTPO from this cytokine combination decreased the number of CD34+/CD41+ and CD34-/CD41+ cells, after days 6 and 8, respectively. Day 0 cells required rIL-3 for promoting colonies containing megakaryocytes, whereas rTPO alone promoted almost no megakaryocytic colonies from day 0 cells. Thus, a combination of IL-3 and SCF expands CD34+/CD41+ cells from CD34+/CD41- cells, and TPO mainly acts to increase CD34-/CD41+ cells. This study suggests that if the expansion of CD34+/CD41+ is performed in vitro, the 6 days' culture of peripheral blood CD34+/CD41- cells with a combination of IL-3 and SCF with TPO provides the most rapid and stable products of CD34+/CD41+ cells for the rapid recovery of platelets in patients with peripheral blood stem cell transplantation.

Lysosomal glycogen storage disease with normal acid maltase with early fatal outcome

In a male infant who had cardiomyopathy, generalized muscle weakness and increased serum creatine kinase levels, his muscle biopsy revealed myopathic changes with tiny intracytoplasmic vacuoles containing PAS-positive material and high acid phosphatase activity, but had normal acid maltase activity biochemically. These findings were consistent with those seen in lysosomal glycogen storage disease with normal acid maltase (Danon disease). Sarcolemmal indentations commonly seen in this disease were missing, but a complement membrane attack complex, C5b-9 was positive along the surface membrane of the muscle fibers as seen in X-linked vacuolar myopathy. The patient was on a respirator and died at 27 months of age from pneumonia and hypertrophic cardiomyopathy. Lysosomal glycogen storage disease with normal acid maltase may be manifested at birth with marked skeletal and cardiac involvement leading to death in early infancy.

[Evaluation of estimated blood concentration of propofol on wake-up using "ConGrase", a software to control the syringe pump for propofol infusion]

We developed a software to control a Graseby 3500 syringe pump for propofol infusion through the serial port of Apple Macintosh/Power-Macintosh computer. This software, "ConGrase", was developed with Metrowerks CodeWarrior Professional (CWP 1) and PowerPlant framework using C++. ConGrase communicates with the syringe pump at least every three seconds, and calculates the estimated blood concentration (EBC) of propofol based on the amount of propofol actually infused by applying either the Euler or Runge-Kutta method using the three-compartment pharmacokinetic model. The parameter sets reported by Gepts et al. are used. ConGrase was released at the 44 th Annual Meeting of the Japan Society of Anesthesiology, and is distributed freely. The mean and S.D. of the emergence EBC calculated by ConGrase were 1.22 micrograms.ml-1 and 0.16 microgram.ml-1, respectively. These values are almost the same as values already reported outside Japan. The necessary wake-up time can be calculated with this estimated concentration. With this system, anesthetists can control the EBC at the required level and avoid long delays before the patients wake up after anesthesia.

Distribution and neuropeptide content of nitric oxide synthase-containing nerve fibers in arteries and conduction system of the rat heart

The rat heart receives its blood supply not only from the coronary arteries but also from the accessory coronary arteries that supply mainly the atria. The distribution and chemical nature of nitric oxide synthase-containing nerve fibers in the conduction system as well as the coronary and accessory coronary arteries were investigated using immunohistochemistry and NADPH diaphorase (NADPH-d) histochemistry. A few NADPH-d-positive nerve fibers were observed mainly around the main trunk of the coronary arteries, while NADPH-d-positive fibers were found along the entire course of the accessory coronary arteries from their main branches to the arteriolar level. A double-staining method demonstrated that NADPH-d-positive fibers innervating both the coronary and accessory coronary arteries contained vasoactive intestinal polypeptide or neuropeptide Y. NADPH-d-positive fibers were relatively abundant in the sinus node and penetrating bundle but were very sparse in the atrioventricular node and right bundle branch. No NADPH-d-positive fibers were detected in the left bundle branch. Some of the NADPH-d-positive fibers innervating the penetrating bundle exhibited distinct immunoreactivity to calcitonin gene-related peptide. These results suggest that nitric oxide may play a role as a neurotransmitter and/or neuromodulator in the neural control of the cardiac blood flow and impulse conduction.

Recurrent dorsal angulation of the distal radius fracture during dynamic external fixation

Thirty-three fractures of the distal radius treated with a dynamic external fixator (that allowed for wrist motion between 2 to 4 weeks after surgery) were analyzed, focusing on loss of fracture reduction during external fixation. Fractures with preoperative dorsal angulation greater than 20 degrees and those involving the distal radioulnar joint had a significantly larger loss of reduction of dorsal angulation (8.9 degrees and 6.9 degrees, respectively) than fractures with less severe preoperative dorsal angulation or those with an intact distal radioulnar joint (3.0 degrees and 2.6 degrees, respectively). In contrast, preoperative radial shortening (>2 mm) and involvement of the radiocarpal joint did not significantly increase the loss of dorsal angulation. Neither of the 2 dynamic external fixation systems studied consistently stabilized Colles' fractures with preoperative dorsal angulation of greater than 20 degrees or involvement of the distal radioulnar joint.

[Myelodysplastic syndrome (RAEB in T) developed in a renal allograft recipient]

A 46-year-old man who had been treated with azathioprine (150 mg/day) and prednisolone (7.5-10 mg/day) for 16 years after allogeneic renal transplantation was admitted to our hospital in July 1996 for evaluation of pancytopenia. Three years earlier he had been given a diagnosis of renal pelvic and ureteral cancer, and underwent left nephrectomy with total uretectomy. His bone marrow was normocellular with excess of blasts (27.6%), and displayed trilineage myelodysplasia. A chromosomal analysis of the bone marrow revealed 43-45, XY with del (1) (p13), -5, del (7) (q22), -17, -18, and -19. The patient was given a diagnosis of refractory anemia with excess of blasts in transformation (RAEB in T), and treated with idarubicin and cytosine arabinoside. Two months later, overt acute leukemia developed and reinduction chemotherpay was started, but the patient died of cerebral hemorrhage in October. This case suggests that immunosuppressive agents such as azathioprine might play an important role in the pathogenesis of MDS (RAEB in T) and renal pelvic and ureteral cancer after renal transplantation.

Different adhesive characteristics and VLA-4 expression of CD34(+) progenitors in G0/G1 versus S+G2/M phases of the cell cycle

We identified the cell cycle status of CD34(+) cells of steady-state bone marrow (BM) and peripheral blood (PB) obtained from healthy volunteers, and those of apherasis PB samples collected from healthy donors who had been administered granulocyte colony-stimulating factor (G-CSF). More than 10% of CD34(+) cells in BM were in S+G2/M phase. In contrast, regardless of whether G-CSF treatment was performed, less than 2% of CD34(+) cells in PB were cycling. BM CD34(+) cells showed greater VLA-4 expression and adherence to stromal cells than PB CD34(+) cells. In addition, when cycling and dormant BM CD34(+) cells were analyzed separately, the cells in S+G2/M phase expressed more VLA-4 and adhered to the stromal cell monolayer more efficiently than the cells in G0/G1 phase. Furthermore, this adhesion of CD34(+) cells to the stromal cell layer was almost completely inhibited by anti-VLA-4 antibody. Taken together, these results suggest that CD34(+) progenitors in G0/G1 phase of the cell cycle differ from those in S+G2/M phase in adhesiveness mediated by VLA-4 in the hematopoietic microenvironment.

[Autoimmune thrombocytopenia following syngeneic peripheral blood stem cell transplantation]

A 35-year-old man with non-Hodgkin's lymphoma (NHL) (follicular small cleaved, B cell, stage IVB) received double myeloablative chemotherapy with syngeneic peripheral blood stem cell transplantation (PBSCT). Although platelet recovery was delayed until day 29 after the second transplantation, thereafter trilineage hematopoietic reconstitution was achieved. The evaluation after PBSCT did not detect any residual tumor. The patient was in good health until day 138, when his platelet count suddenly began falling; on day 150, it had fallen to 1.5 x 10(4)/microliter, and the patient was re-admitted for treatment. The bone marrow was normocellular with a normal count and megakaryocyte structure. Other examinations, including serological tests and computed tomography of the neck, chest, abdomen, and retroperitoneum, did not indicate a recurrence of NHL or reveal the cause of thrombocytopenia. The patient's platelet-associated IgG (PAIgG) level was at 70.9 ng/10(7) platelets (normal range: 9-25 ng/10(7) platelets); a diagnosis of thrombocytopenia due to an autoimmune mechanism such as idiopathic thrombocytopenic purpura (ITP) was made. Prednisolone therapy increased the platelet count and reduced the PAIgG level. Thrombocytopenia with an ITP-like mechanism rarely occurs more than 100 days after autologous or syngeneic stem cell transplantation, and should be taken into consideration as a late complication of PBSCT.

Erythropoietin induces tyrosine phosphorylation of Jak2, STAT5A, and STAT5B in primary cultured human erythroid precursors

We examined signaling by erythropoietin in highly purified human colony forming unit-erythroid cells, generated in vitro from CD34(+) cells. We found that erythropoietin induces tyrosine phosphorylation of Jak2, STAT5A, and STAT5B. Tyrosine phosphorylation of Jak2 reaches a peak around 10 minutes after stimulation and is maximum at 5 U/mL of erythropoietin. Tyrosine phosphorylation of STAT5 is accompanied by the translocation of activated STAT5 to the nucleus as shown by electrophoretic mobility shift assay (EMSA) using 32Pi-labeled STAT5 binding site in the beta-casein promoter. Tyrosine phosphorylation STAT1 or STAT3 was not detected in human erythroid precursors after stimulation with erythropoietin. Crkl, an SH2/SH3 adapter protein, becomes coimmunoprecipitated specifically with STAT5 from erythropoietin-stimulated erythroid cells; although it was shown to become associated with c-Cbl in the studies using cell lines. Thus, human erythroid precursors can be expanded in vitro in sufficient numbers and purity to allow its usage in signal transduction studies. This report sets a basis for further studies on signaling in primary cultured human erythroid precursors, which in turn contribute to our better understanding in the differentiation processes of erythrocytes and their precursors.

[Gamma-heavy chain disease associated with MALT lymphoma of the duodenum]

We report a case of a 63-year-old woman with gamma heavy chain disease (HCD) associated with mucosa-associated lymphoid tissue (MALT) lymphoma of the duodenum. She was suffering from drug-resistant tonsillitis with high fever. Examination on admission showed leukocytopenia and thrombocytopenia. Bone marrow aspirate revealed granulocytosis and a hypocellular marrow with no increase in plasma cells or atypical lymphocytes. Serum electrophoresis disclosed, in addition to hypogamma-globulinemia, an abnormal band due to the presence of gamma HCD protein. This abnormal protein was a molecular weight of approximately 40 kd as determined by Western blots technique, and belonged to the IgG1 subclass as determined by ELISA with monoclonal antibodies against IgG. An endoscopic examination of the patient's duodenum found a small tumorous lesion, which was confirmed pathologically to be MALT lymphoma. HCD is known to be associated with lymphoproliferative diseases. In this case, gamma HCD had developed as a secondary complication of MALT lymphoma. gamma HCD associated with MALT lymphoma of the duodenum is rare in the literature.