Radioprotective effects of various cytokines in peripheral blood mononuclear cells and C3H mice

The purpose of this study was to investigate the radioprotective effect of HGFs (GM-CSF, IL-3 and SCF) in irradiated human peripheral blood mononuclear cells (PBMCs) in vitro, and the survival effect of lethally irradiated C3H mice in vivo. The irradiation of human PBMCs using a (137)Cs irradiator showed a dose-dependent inhibition of cell growth up to a dose of 5 Gy. This cell growth inhibition induced apoptosis, which was associated with the down-regulation of Bcl-2, up-regulation of Bax, depolarization of mitochondrial transmembrane potential (Delta psi m), and caspase-3 and -9 activation. Following gamma-irradiation at 2 Gy, IL-3 (10 ng/ml) alone or combined with SCF (50 ng/ml) reduced the apoptotic portion of human PBMCs by 15 and 20% of the cell population, respectively, showing no activation of caspase-3 compared to the control group. To examine the in vivo effect of gamma-irradiation and cytokines, we investigated the survival rate and recovery of peripheral blood cells in C3H mice. C3H mice subjected to total body irradiation (TBI) at a dose of 7 Gy (lethal dose 83% at 30 days) showed time-dependent decreases in RBC, WBC and platelet counts, with the nadir occurring at 12 to 15 days. However, treatment with recombinant murine (rm) SCF (2 microg/day s.c.), rmIL-3 (2 microg/day s.c.), or rmG-CSF (2.5 microg/day s.c.) 24 h before and after irradiation did not promote hematologic recovery or survival in the lethally irradiated C3H mice. These findings indicate that the combined treatment of IL-3 and SCF prevents the apoptosis induced in PBMCs by gamma-irradiation in vitro, but it does not afford any in vivo radioprotective effect in lethally irradiated C3H mice.     

Secondary hematological malignancies after breast cancer chemotherapy

According to several reports, the 10 year incidence of secondary acute myelogenous leukemia (AML) or myelodysplastic syndrome (MDS) after systemic chemotherapy is approximately 1.5%. The cumulative risk increases by 0.25 - 1% for the first 8 years after treatment. We have reported only 6 cases of hematological malignancies (0.3%) after breast cancer chemotherapy in our institute. We detected 2 cases of secondary AML and 1 case of MDS, 19, 52 and 12 months, respectively, after systemic chemotherapy for breast cancer. Published data on the occurrence of secondary hematological malignancies other than AML or MDS in this setting are scarce. We encountered diffuse large B-cell lymphoma, angioimmunoblastic lymphoma and mantle cell lymphoma as secondary hematological malignancies after systemic chemotherapy for breast cancer.     

Production and characterization of monoclonal antibodies to mesenchymal stem cells derived from human bone marrow

The bone marrow (BM) serves as a reservoir for different classes of stem cells. In addition to haematopoietic stem cells, bone marrow contains a population of mesenchymal stem cells (MSCs). These cells have a multilineage differentiation capacity and are able to generate progenitors with restricted developmental potential, which include fibroblasts, osteoblasts, adipocytes, and chondrocytes. Characteristic markers have been reported for expanded MSCs, but none of these markers are specific for MSCs. Thus, the objective of this study was to produce monoclonal antibodies against MSCs. MSCs derived from human bone marrow were cultured, expanded, and immunized into mice, and spleen cells subsequently harvested were used to generate hybridoma cell lines secreting antibodies against MSCs. Hybridoma culture supernatants were screened for antibodies against MSCs by enzyme-linked immunosorbent assay (ELISA), and 33 positive clones were then screened against cell suspensions of MSCs by immunofluorescence staining and flow cytometry. Ten clones were positive in immunofluorescence staining. Among these, three hybridoma cell lines, namely, YS08, YS14, and YS18 were found to be reactive with MSC by flow cytometry, but non-reactive with human tumor cell lines and hematopoietic stem cells. YS08 and YS14 showed specific bands in Western blotting. In conclusion, we developed three monoclonal antibodies, YS08, YS14, and YS18, that recognize human MSC cell surface antigen.     

Inhibition of the catalytic activity of hypoxia-inducible factor-1alpha-prolyl-hydroxylase 2 by a MYND-type zinc finger

Hypoxia-induced gene expression is initiated when the hypoxia-inducible factor-1 (HIF-1) alpha subunit is stabilized in response to a lack of oxygen. An HIF-1alpha-specific prolyl-hydroxylase (PHD) catalyzes hydroxylation of the proline-564 and/or -402 residues of HIF-1alpha by an oxygen molecule. The hydroxyproline then interacts with the ubiquitin E3 ligase von Hippel Lindau protein and is degraded by an ubiquitin-dependent proteasome. PHD2 is the most active of three PHD isoforms in hydroxylating HIF-1alpha. Structural analysis showed that the N-terminal region of PHD2 contains a Myeloid translocation protein 8, Nervy, and DEAF1 (MYND)-type zinc finger domain, whereas the catalytic domain is located in its C-terminal region. We found that deletion of the MYND domain increased the activity of both recombinant PHD2 protein and in vitro-translated PHD2. The zinc chelator N,N,N',N'-tetrakis(2-pyridylmethyl)ethylenediamine augmented the activity of wild-type PHD2-F but not that of PHD2 lacking the MYND domain, confirming that the zinc finger domain is inhibitory. Overexpression of PHD2 lacking the MYND domain caused a greater reduction in the stability and function of HIF-1alpha than did overexpression of wild-type PHD2, indicating that the MYND domain also inhibits the catalytic activity of PHD2 in vivo.     

Dysplasia epiphysealis capitis femoris: Meyer dysplasia

The clinical importance of dysplasia epiphysealis capitis femoris (Meyer dysplasia) is that it is easily mistaken for Legg-Calve-Perthes disease, leading to unnecessary diagnostic procedures and treatments. After a review of 578 children (619 hips) with Legg-Calve-Perthes disease, 17 children (27 hips) in whom both the clinical and radiologic pattern was obviously different could be found and a diagnosis of dysplasia epiphysealis capitis femoris was finally made. The mean age was 2.5 (range 1.9-3.6) years. There were 16 boys and 1 girl. Ten children had bilateral involvement (59%). The capital femoral epiphysis was delayed or was smaller in 26 hips, separated or cracked in 15, and cystic in 6. A normal bone structure was established in approximately 2 to 4 years. The final results assessed by the Mose and the Stulberg classification were good in all 27 hips. This study suggests guidelines for evaluating this rare condition based on the authors' findings and a review of the literature.     

Benign duodenal strictures: treatment by means of fluoroscopically guided balloon dilation

Fluoroscopically guided balloon (15 or 20 mm in diameter) dilation was performed on eight patients with benign duodenal strictures caused by peptic ulcers (n = 6), Crohn's disease (n = 1), and postoperative adhesion (n = 1). The procedure was technically and clinically successful without complications in seven of the eight patients (88%). Duodenal perforation occurred immediately after 20-mm-diameter balloon dilation in one patient who underwent emergency surgery. During the mean follow-up of 30 months (range, 2-103 months), there was recurrence in two of the seven patients (29%) who then underwent surgery. The other five patients (71%) showed good results with no recurrence.     

Arthroscopic synovectomy in haemophilic arthropathy of the knee

From January 1996 to January 2001, arthroscopic synovectomies were performed in 28 knees with haemophilic arthropathy. The mean follow-up period was 5 years and 11 months. Six portals (two anterior, two suprapatellar, two posterior) and a posterior trans-septal portal were used in all cases. The average Hospital for Special Surgery (HSS) knee score increased from 56.4 to 71.5 points at the last follow-up. The average frequency of haemarthrosis reduced from five times per month before operation to once per month. The amount of factor replacement decreased from a mean of 4,633 U to 1,505 U. Progression of arthritis was observed radiographically in three cases at the last follow-up. An arthroscopic synovectomy of the knee using appropriate arthroscopic portals is a useful method in treating haemophilic patients as it decreases bleeding episodes, amount of factor replacement and knee pain.

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Résumé De janvier 1996 à janvier 2001, des synovectomies arthroscopiques ont été exécutées dans 28 genoux avec une arthropathie hémophilique. Le suivi moyen était 5 années et 11 mois. Six abords (deux antérieurs, deux supra-rotuliens, deux postérieurs) et un abord trans-septal postérieur ont été utilisé dans tous les cas. Le score moyen du genou de lHôpital pour Chirurgie Spéciale (HSS) a augmenté de 56,4 à 71,5 points au dernier examen. La fréquence moyenne dhémarthrose sest réduite de cinq fois par mois avant lopération à une fois par mois aprés. La quantité moyenne de remplacement de facteur a diminué de 4,633 à 1,505 unités. Dans lévaluation radiographique, la progression de larthrite a été observée dans trois cas au dernier suivi. Une synovectomie arthroscopique du genou qui utilise des abords arthroscopiques appropriés est une méthode utile pour traiter les malades hémophiliques, diminuant les épisodes de saignement, la quantité de facteur et les douleurs du genou.