Takakuni Tanizawa

Impact of the mobilization regimen and the harvesting technique on the granulocyte yield in healthy donors for granulocyte transfusion therapy

BACKGROUND: Granulocyte mobilization and harvesting, the two major phases of granulocyte collection, have not been standardized.

Granulocyte‐macrophage colony‐stimulating factor abrogates transforming growth factor‐β1‐mediated cell cycle arrest by up‐regulating cyclin D2/Cdk6

The role of positive and negative cytokine interactions in G1 cell cycle regulation of haemopoietic cells was analysed by determination of the expression patterns of D‐type cyclins and cyclin‐dependent kinases (cdks) in SKM‐1 myelodysplastic syndrome (MDS) cells incubated with granulocyte‐macrophage colony‐stimulating factor (GM‐CSF) and/or transforming growth factor‐β1 (TGF‐β1). TGF‐β1 inhibited SKM‐1 cell proliferation due to the cell cycle arrest in G1 phase. GM‐C18SF abrogated the TGF‐β1‐mediated G1 arrest in these cells. Reverse transcription‐polymerase chain reaction (RT‐PCR) analysis indicated that TGF‐β1‐mediated G1 arrest correlated with the down‐regulation of cdk4, cdk6 and cyclin D2, and that abrogation of TGF‐β1‐mediated G1 arrest by GM‐CSF correlated with the constitutive over‐expression of cyclin D2 and cdk6 but not cdk4. These results suggest the importance of cyclin D2/cdk6 levels in abrogating G1 arrest in cells exposed to TGF‐β1, and raise the possibility that the GM‐CSF‐mediated up‐regulatory pathway of signal transduction through cyclin D2/cdk6 differs from the TGF‐β1‐cdk4‐mediated pathway in SKM‐1 cells. This signal transduction pathway through cyclin D2/cdk6 might play an important role in haemopoietic regulation by the cytokine network.

Immunohistochemical localization of glomerular basement membrane antigens in various renal diseases

The immunofluorescent localization of glomerular basement membrane (GBM) antigens was examined in 52 specimens from normal kidneys and in various renal diseases using antisera to human GBM HGBM), IV type collagen (IV Col) and P3 antigen, a rat nephritogen. Anti-HGBM serum normally stained the GBM and the mesangium in a restrictive pattern, anti-IV Col serum stained the GBM and the mesangium in a wider pattern and anti-P3 serum stained only the GBM. In mesangial proliferative glomerulonephritis, including IgA nephropathy pathy and Henoch-Schönlein nephritis, the widened mesangial areas were stained with anti-HGBM and anti-IV Col sera. In membranous nephropathy, the punched-out lesions of thickened GBM were demonstrated with the three antisera in moderate cases and a double linear distribution with fine granulation with anti-HGBM and anti-IV Col sera were revealed in one severe case. In membranoproliferative glomerulonephritis, the expanded mesangium and thickened capillary walls were stained with anti-HGBM and anti-IV Col sera, while the outer line of glomerular capillary walls was only positive with anti-P3 serum. In crescentic glomerulonephritis, the collapsed glomerular tufts were stained normally with anti-HGBM and anti-P3 sera and weakly with anti-IV Col serum. In diabetic nephropathy, anti-HGBM serum stained the GBM in a double linear distribution without reacting with the expanded mesangium; anti-IV Col serum stained the mesangium and the GBM in a less clear double linear fashion while anti-P3 serum stained the GBM as single line. Thin membrane disease and Alports syndrome had normal reactivity with all antisera. However, in one case of Alports syndrome anti-HGBM and anti-P3 sera stained the GBM in a focal and segmental pattern, while normal staining with anti-IV Col serum was found. In lesions with adhesions and crescents the staining was positive for HGBM and IV Col and negative for P3; obsolescent glomeruli were stained with anti-HGBM and anti-P3 sera, and had diminished staining with anti-IV Col serum. The identification of the various structural glomerular antigens is useful in the classification of certain types of glomerular diseases. Further insight into the mechanisms underlying these conditions may be obtained in this way.

Correlation of c‐kit expression and cell cycle regulation by transforming growth factor‐beta in CD34+ CD38− human bone marrow cells

Abstract: To investigate the relationship between c‐kit expression and cell cycle regulation by endogenous transforming growth factor‐beta (TGF‐β) in human bone marrow hematopoietic progenitor cells, CD34+ CD38−c‐kitlow/− and CD34+ CD38−c‐kithigh populations were cultured in stem cell factor, thrombopoietin, interleukin‐3 (IL‐3), IL‐6, granulocyte colony‐stimulating factor, granulocyte/macrophage colony‐stimulating factor and anti‐TGF‐β, and analyzed for cell cycle status. Arrest in G0/G1 was most prominent in the precultured CD34+ CD38−c‐kitlow/− subset (95.62 ± 4.15%). While postcultured CD34+ CD38−c‐kithigh cells initiated from CD34+ CD38−c‐kithigh cells entered cell cycle within 36 hr, postcultured CD34+ CD38−c‐kitlow/− cells initiated from CD34+ CD38−c‐kitlow/− cells remained dormant until 36 hr and entered cell cycle within 90 hr. Anti‐TGF‐β increased the percentage of S/G2M phase postcultured CD34+ CD38−c‐kithigh cells (from 19.08 ± 11.95 to 47.04 ± 2.93%), but no significant change was observed in postcultured CD34+ CD38−c‐kitlow/− cells. These results suggest that endogenous TGF‐β plays an important role in the cell cycle arrest of c‐kithigh but not c‐kitlow/− cells in CD34+ CD38− cells, which proliferate without undergoing differentiation. The different regulatory mechanism of cell cycle entry of the CD34+ CD38−c‐kithigh and CD34+ CD38−c‐kitlow/− subsets might be the result of differences in their sensitivity to endogenous TGF‐β.

Extramedullary relapse of acute lymphoblastic leukemia in childhood to the prostate.

Abstract:  A 6‐year‐old boy presented with the chief complaints of miction pain and pollakisuria. He had a past history of acute lymphoblastic leukemia (ALL), which subsided in response to chemotherapy at 3 years of age. Ultrasonography revealed urinary retention associated with bilateral hydronephrosis secondary to the prostate enlargement. Computed tomography and magnetic resonance imaging showed no other abnormal finding. Transrectal needle biopsy showed infiltration of leukemic cells in the prostate. Bone marrow puncture and cerebrospinal fluid aspiration revealed no leukemic cells, resulting in a diagnosis of extramedullary relapse of ALL in the prostate. Although he was successfully treated by chemotherapy, irradiation and his voiding function was improved, ALL relapsed in the left testis 1 year later. In spite of left orchiectomy, irradiation and additional chemotherapy, he died of bone marrow relapse and multiple organ failure. Extramedullary relapse of ALL in the prostate is very rare. To our knowledge, our case is the first well‐documented report in the published work.

Mineralocorticoid Receptor Blocker Protects against Podocyte-Dependent Glomerulosclerosis

Background: We previously showed that angiotensin type 1 receptor (AT1) blocker (ARB) attenuates glomerular injury in Nphs1-hCD25 (NEP25) transgenic mice, a model of selective podocyte injury. However, subsequent studies in NEP25 mice with podocyte-specific deficiency of AT1 revealed that the protective effects of ARB are not through the podocyte AT1, thereby raising the possibility that the protective effects of ARB involve mineralocorticoids. Methods: NEP25 mice were treated with the mineralocorticoid receptor blocker (MRB) spironolactone (25 mg/kg/day, n = 10), the ARB losartan (250 mg/kg/day, n = 11), both (ARB+MRB, n = 8) or vehicle (Vehicle, n = 9) from day –7 to day 9 of induction of podocyte injury. Results: Although MRB did not reduce systolic blood pressure or proteinuria, addition of MRB to ARB significantly attenuated glomerulosclerosis (glomerulosclerosis index: ARB+MRB 1.67 ± 0.19 vs. MRB 2.01 ± 0.29, ARB 2.35 ± 0.19, and Vehicle 2.25 ± 0.26, p < 0.05) and preserved the number of WT1-positive podocytes (ARB+MRB 152.5 ± 9.7 vs. MRB 117.2 ± 9.0 or ARB 113.6 ± 7.4, and ARB+MRB vs. Vehicle 97.5 ± 4.0 per glomerulus; p < 0.05). Conclusion: These data suggest that, while MRB does not attenuate proteinuria caused by podocyte-specific injury, it provides protective effects against glomerulosclerosis that is independent of systemic blood pressure.

Semiquantitative scoring in children under treatment for atopic dermatitis.

Abstract Background : Atopic dermatitis is the most frequently seen childhood allergic disease in outpatient clinics. Improvement, exacerbation, and response to treatment are typically assessed subjectively and occasionally inaccurately.

Doppler Echocardiographic Differentiation of Func-tional From Anatomical Pulmonary Atresia

Functional pulmonary atresia must be distinguished from anatomical atresia, which has an intact ventricular septum, to avoid inappropriate treatment, but there is a paucity of data regarding the echocardiographic features that differentiate these conditions. Echocardiographic findings in 5 neonates with functional atresia were compared to those in 5 with anatomical atresia. The left and right ventricular end-diastolic dimensions (LVDd, RVDd), percent of normal predicted LVDd, RVDd/LVDd, tricuspid valve ring diameter (TVD), percent of normal predicted TVD, grade of tricuspid regurgitation (TR), peak TR velocity, pulmonary valve ring diameter (PVD), percent of normal predicted PVD, the minimum diameter of the ductus and the peak velocity through it (PDA velocity) were measured. In addition, systolic pulmonary (PAp) and right ventricular pressure (RVp) from either PDA velocity or TR velocity, and calculated PAp/RVp were also estimated. There were significant differences in RVDd/LVDd, %TVD, and peak TR velocity between the 2 groups. All functional patients showed RVDd/LVDd >0.6, %TVD >100%, estimated RVp 0.85, and peak TR velocity <4 m/s, whereas the findings in anatomical atresia patients were completely the opposite. In conclusion, a large RVDd/LVDd, TVD, PAp/RVp, low RVp and small TR velocity all suggest functional rather than anatomical pulmonary atresia, although there may be some exceptions such as severe Ebstein anomaly. (Circ J 2002; 66: 665 - 667)

Glycine plays a crucial role as a co-agonist of NMDA receptors in the neuronal circuit generating body movements in rat fetuses

Neuronal circuits generating fetal movements in mammals are localized in the brainstem and the spinal cord. It has been shown that glycine plays an important role through the strychnine-sensitive glycine receptors in these circuits. However, the role of glycine as the NMDA receptor co-agonist in fetal period is not fully understood. In this study, we examined the contribution of glycine to the perinatal rat spinal circuit generating forelimb movements utilizing isolated brainstem-cervical-spinal-cord preparations. In late embryonic-days-preparations, spontaneous motor bursts related to forelimb movements (forelimb-movement-related bursts; FMRBs) and respiration-related activity were observed. In neonatal preparations, spontaneous FMRBs were not observed but periodic motor bursts resembling the FMRBs could be induced after bath application of strychnine (strychnine-induced motor bursts; SIMBs). Both FMRBs and SIMBs were blocked by either the NMDA receptor antagonist APV or the antagonists of the glycine binding site of NMDA receptors [5,7-dichlorokynurenic acid (DCKA) or L-689560]. Furthermore, these motor bursts were facilitated by the glycine uptake blocker sarcosine. This effect of sarcosine was blocked by DCKA. The findings indicate that glycine plays a crucial role as a NMDA receptor co-agonist in generating spontaneous fetal motor activity before functioning as a classical inhibitory neurotransmitter in suppressing the fetal neuronal circuits.

Disseminated necrotizing leukoencephalopathy following chemoradiation therapy for acute lymphoblastic leukemia

Disseminated necrotizing leukoencephalopathy (DNL) is a potentially fatal complication of treatment involving intrathecal administration of chemotherapeutic agents such as methotrexate (MTX) alone or in combination with cranial radiotherapy (RT). We describe a case of acute lymphoblastic leukemia (ALL) treated with high-dose intravenous and intrathecal methotrexate combined with craniospinal RT resulting in DNL. Typical MR imaging features of progressive deep white matter lesions showing a characteristic pattern of enhancement after contrast was seen in this case. Deep white matter lesions with ring-like enhancement and calcifications were seen on CT; it showed a mass effect at one stage, which is not typical for DNL. Long-term clinical and imaging follow-up were helpful for the diagnosis in this case.