Immunoreactivity of MIC2 (CD99) in acute myelogenous leukemia and related diseases.

MIC2 is characteristically expressed in lymphoblastic lesions and Ewing's/primitive neuroectodermal tumor sarcomas. Although MIC2 has recently been reported in chloroma and rare terminal deoxynucleotidyl transferase-positive acute myelogenous leukemia (AML), the incidence and the significance of MIC2 (CD99) immunoreactivity in myeloid lesions is not clear. In this study, we evaluated MIC2 positivity in a variety of myeloid diseases and normal marrow to determine its incidence and distribution in myeloid diseases; its correlation with flow cytometric and cytogenetic data in AML; and its association with leukemic transformation, relapse, and chloroma formation. Paraffin sections of 11 chloromas and 94 bone marrow core biopsies from 66 patients were stained with CD99 monoclonal antibody 12E7. Of 94 bone marrow core biopsies, there were 30 AML (fragment antigen binding M0 to M6), 23 remissions, 5 relapses, 12 myeloproliferative disorders, 13 myelodysplastic syndromes, and 11 normal marrows from patients who did not have leukemia. CD99 immunoreactivity was evaluated with light microscopy. MIC2 expression was seen in leukemic blasts in 6 of 11 chloromas (55%) and 13 of 30 AML (43%) but rarely in myeloproliferative disorders, myelodysplastic syndromes, remission, and normal marrow. CD99 tended to be positive in M1-, M3-, and HLA-Dr-negative AML and negative in AML with relapse. MIC2 expression did not correlate with the karyotype independent of French-American-British Cooperative Group classification and the disease remission or occurrence of chloroma in AML. We concluded that MIC2 is commonly expressed in leukemic blasts of AML and is not predictive of leukemic transformation from myeloproliferative disorders and myelodysplastic syndromes or chloroma formation. Caution should be taken when using MIC2 as a marker for Ewing's sarcoma/ primitive neuroectodermal tumor or lymphoblastic lymphoma on paraffin sections of either soft tissue or bone marrow specimens.     

Minimal residual disease in childhood B-lineage lymphoblastic leukemia. Persistence of leukemic cells during the first 18 months of treatment

BACKGROUND. Whether patients in clinical remission for acute lymphoblastic leukemia (ALL) continue to harbor leukemic cells is not known, because methods of detecting residual malignant cells have not been sufficiently sensitive. This information might be useful for predicting recurrence and determining the duration of therapy. METHODS. Using a sensitive new method--identifying complementarity-determining region III sequences with the polymerase chain reaction--we estimated the number of residual leukemic cells in the bone marrow of eight children with B-lineage lymphoblastic leukemia before and after remission. RESULTS. Induction chemotherapy produced a 3-to-4-log reduction in the number of leukemic cells. In all samples obtained up to 18 months after diagnosis, however, 0.004 to 2.6 percent of bone marrow nucleated cells were residual leukemic cells. Among the four patients studied more than 18 months after diagnosis, three had no detectable leukemic cells in marrow samples. Despite this, one of them, who was no longer receiving therapy, had a central nervous system relapse. In one patient receiving maintenance chemotherapy, there was a 60-fold increase in leukemic cells three months before bone marrow relapse. CONCLUSIONS. The complete disappearance of leukemic cells (or their reduction below our method's threshold of detection, 1 in 100,000 cells) may be necessary to achieve a cure of ALL. The quantification of residual leukemic cells in serial marrow aspirates during therapy may allow the early detection of relapse.     

CD9、CD10单克隆抗体免疫毒素对白血病细胞的清除率及对造血细胞的影响

特异性识别C-ALL、Null-ALL白血病细胞表面相应抗原的单克隆抗体(CD9、CD10)与具有杀伤细胞的蓖麻毒素偶联制备的免疫毒素在自体骨髓移植中,对残留白血病细胞的清除,预防移植后白血病的复发是有意义的。本实验观察了两组抗人白细胞分化抗原单克隆抗体(CD9、CD10)免疫毒素对白血病细胞(Nalm-6)的清除率。及它们在有效清除白血病细胞剂量范围内对骨髓多向性造血祖细胞、红系和粒单系造血祖细胞增殖的影响。探讨了免疫毒素在骨髓移植中应用的可行性。     

Recommendation of modified classification for odontogenic carcinomas

Primary squamous cell carcinoma (SCC) derived from odontogenic epithelium is diagnosed as primary intraosseous carcinoma (PIOC). The term "intraosseous" means the bone marrow spaces. Odontogenic cells, however, exist not only in the bone marrow space but also in the periodontal space and the subepithelial soft tissue space. In our survey for 36 SCC lesions of odontogenic origin, many lesions involved two or all of the three spaces. There was only one lesion which involved the bone marrow space alone. In some cases, the extent of the early lesions was restricted around the tooth or at a part of the alveolar crest. The possibility of a SCC of odontogenic origin arising in the periodontal and the subepithelial soft tissue spaces was suggested. We proposed the term "Odontogenic SCC" to replace "PIOC".     

Cytogenetics in patients with chronic myelogenous leukemia treated with bone marrow transplantation

Cytogenetic data are reported from 16 patients with Philadelphia chromosome (Ph) positive chronic myelogenous leukemia (CML) treated with bone marrow transplantation (BMT). The usefulness of cytogenetic investigations for the assessment of marrow engraftment is stressed. The significance of persistence or reappearance of Ph after BMT, possibly due to a defective leukemic clone eradication by the conditioning regimen, is also discussed. Generally, Ph-positive cells are damaged and disappear within the first year of BMT. Sometimes, however, the cells may repair the damage and proliferate again, resulting in disease relapse. Rarely, clinical and hematologic relapse does not follow Ph-positive clone expansion although leukemic cells represent more than 50% of marrow metaphases examined. Finally, the effect of interferon on Ph-positive clones after BMT and random chromosome changes, that appear transiently after BMT and are of uncertain significance, are discussed.     

B-cell precursors in normal pediatric bone marrow

A number of studies have been published pertaining to "normal" lymphocyte subsets in bone marrow. However, these studies are based on normal adult marrow or marrows of children with leukemia in remission or other systemic illness. Data on hematologically normal children are lacking. This study demonstrates that, compared with that of adults, bone marrow of hematologically normal children has an increased percentage of B cells and B-cell precursors. Dual-parameter flow cytometric methods demonstrated subpopulations of B cells at various stages of differentiation; the percentage of cells in these subsets is highest in the very young and decreases with increasing age. Caution must be exercised when searching for early leukemic relapse in pediatric marrows because these normal immature B-cell precursors immunophenotypically resemble leukemic blasts.     

Floral leukemic cells transformed from marginal zone lymphoma

There are three clinicopathological entities of marginal zone lymphoma (MZL), including extranodal or mucosa-associated lymphoid tissue (MALT) lymphoma and MZL of nodal (NMZL) or splenic (SMZL) type. Of these, leukemic presentation, usually as small or villous lymphocytes, is more common in SMZL, while leukemic change in NMZL is rare, and the morphology has not been characterized. We present a stage 4 MZL involving lymph node, spleen, and bone marrow with two relapses after chemotherapy. The leukemic cells at the second relapse revealed irregular nuclear contours with multilobated nuclei (so-called flower cells or floral cells) mimicking the neoplastic cells in adult T-cell leukemia/lymphoma (ATLL). The absence of leukemic change and splenic hilar lymphadenopathy at initial presentation, expression of IgD by tumor cells, and cytogenetic changes of +7 suggested that this tumor might be a NMZL. Although the cytomorphologic features of floral leukemic cells might suggest ATLL, thorough clinical and laboratory workup helped to reach a correct diagnosis. Our findings broaden the cytological spectra of leukemic cells in MZL and illustrate the importance of immunophenotyping.     

Growth rate and sister chromatid exchange (SCE) incidence of bone marrow cells in Acute Myeloblastic Leukemia (AML)

The sister chromatid exchange (SCE) incidence and growth kinetics have been studied by means of an in vitro bromodeoxyuridine (BrdU) chromosome labeling method in the bone marrow cells of 17 acute myeloblastic leukemia (AML) patients with only diploid cells at diagnosis, remission, and relapse of the disease. At diagnosis, the cells tended to exhibit a low SCE frequency as compared to that during remission. An increased SCE frequency was observed after chemotherapy during remission or relapse. At diagnosis and relapse, when leukemic blast cells predominated in the marrow, they were characterized by the predominance of cells that had undergone only one cell cycle after BrdU exposure. In contrast, the marrow cells during remission tended to resemble the control pattern of growth kinetics, with a predominance of cells undergoing second and third cell cycles in the presence of BrdU. These results suggest that the growth rate of leukemic and nonleukemic cells is different, and that chemotherapy can cause an increased SCE frequency in the marrow cells of AML patients irrespective of the state of the disease.     

The role of total body irradiation in preparation for bone marrow transplantation in acute leukaemia. A review.

From extrapolation obtained from animal studies and radiation accidents, it is assumed that for man the LD 50 (30) will be between 300-500 rads total body irradiation (TBI) and the LD 100 at least 600 rads TBI. A dose of 1000 rads TBI is generally used in man for conditionning for bone marrow transplantation. In acute leukemia, total body irradiation is usually associated with cytoreductive chemotherapy. In Seattle 110 patients underwent bone marrow transplantation for acute leukemia in relapse. 15 patients became long term survivors. The main cause of failure were GVH, interstitial pneumonitis and leukemic relapse. New attempts are being made to improve the results : (1) better cytoreductive therapy preceding transplanation, (2) bone marrow transplantation during remission of the disease, (3) prevention of interstitial pneumonitis by modifications of the TBI technique.     

Chromosome studies in patients with acute nonlymphocytic or acute lymphocytic leukemia submitted to bone marrow transplantation--results of a European cooperative study

The chromosomal data of 58 acute nonlymphocytic leukemia (ANLL) patients and of 32 acute lymphocytic leukemia (ALL) patients submitted to bone marrow transplantation and collected from nine institutions are reported. Chromosomal studies were available at diagnosis in 19 cases with ANLL: seven had a partially or completely abnormal pattern. Forty-one patients had a chromosome study before bone marrow transplantation and all had a normal pattern. Thirteen patients with ALL were studied at diagnosis: five had a partially or completely abnormal karyotype. Of 20 cases analyzed before bone marrow transplantation, only one has maintained the abnormal pattern of diagnosis in part of the cells. Karyotypes were available in nine ANLL patients relapsed after bone marrow transplantations. Two showed the same clonal abnormalities seen at diagnosis; in three other cases the leukemic clone of relapse carried an additional chromosome abnormality with respect to the pattern at diagnosis and four more cases presented at relapse complex abnormalities; two of them had a cytogenetically normal pattern at diagnosis. In four of ten relapsed ALL cases chromosomes analyses were available. A relapse in donor cells and a hyperdiploid pattern were observed in two cases, respectively, while a normal, recipient pattern was documented in the other two cases. Serial chromosome studies performed in acute leukemia patients after bone marrow transplantation may allow the detection of different chromosomal patterns of relapse. In those cases who relapsed with a cell clone cytogenetically different from the pattern at diagnosis, a direct role played by the conditioning treatment in the pathogenesis of the relapsing disease may be hypothesized.     

A descriptive tissue evaluation at maxillary interradicular sites: implications for orthodontic mini-implant placement

Few studies have evaluated interradicular anatomy for hard and soft tissue thickness. Because interradicular sites are common regions for mini-implant placement for orthodontic anchorage, the purpose of this study was to provide a guideline to indicate the best location for mini-implants as it relates to the thickness of cortical bone and soft tissue, and to the height of the attached gingival field. CT images from 15 men and 15 women (mean age 27 years, range 23-35 years) were used to evaluate the buccal interradicular cortical bone thickness from and mesial to the central incisor to the 1st molar. To record soft tissue depth at the site of assessment for cortical bone thickness, the mucosa was pierced with a #15 endodontic K-file until the attached rubber stop rested on the mucosa. The height of attached gingiva was measured at the mid-aspect of each tooth using a caliper. There were no significant differences in cortical bone thickness within interradicular sites except for the 2nd premolar/1st molar site. There were also no significant differences in soft tissue thickness within interradicular sites except for the lateral incisor/canine and 2nd premolar/1st molar sites. The height of attached gingiva was greater in the anterior compared to the posterior region and was shortest in the premolar region. Given the limits of this study, mini-implants for orthodontic anchorage may be well placed with equivalent bone-implant contact anywhere within the zone of attached gingiva up to 6 mm apical to the alveolar crest with adequate interradicular space.     

Cytogenetics and bone marrow transplantation

The authors report hematologic and cytogenetic data on 19 patients treated with allogeneic bone marrow transplantation (BMT) for severe hematologic disorders: 8 patients with chronic myelogenous leukemia, 6 with acute leukemia, 3 with severe aplastic anemia, 1 with refractory anemia, and 1 with beta-thalassemia major. Cytogenetic assays were performed on marrow cells before conditioning, 30 days after BMT, and at subsequent times. The authors discuss the role of cytogenetic studies in the evaluation of bone marrow engraftment, leukemic transformation of the graft, and disease relapse.     

Generation of dendritic cells expressing bcr-abl from CD34-positive chronic myeloid leukemia precursor cells

Patients with a relapse of chronic myeloid leukemia (CML) after allogeneic bone marrow transplantation can be successfully treated with blood mononuclear cells from the original bone marrow donor. However, the antileukemic effect of this treatment is often accompanied by graft-versus-host disease (GVHD). Treatment with cytotoxic T-lymphocyte (CTL) lines or clones that are specifically generated against leukemic antigen-presenting cells from the patient, may separate antileukemic effects from GVHD. In this report we demonstrate that after culturing CD34-positive cells purified from bone marrow of patients with chronic phase CML in medium containing human serum, GM-CSF, TNF, and IL-4 up to 28% of the cultured cells were dendritic cells, characterized by morphology, phenotypic analysis, and their efficient capacity to stimulate allogeneic T lymphocytes. The expression of HLA and costimulatory molecules and the stimulatory capacity of the dendritic cell-enriched cell suspensions were optimal between days 7 and 10 after onset of the cultures. Fluorescence in situ hybridization revealed that all cultured dendritic cells contained the CML specific (9;22) translocation. PCR analysis showed expression of the translocation specific bcr-abl mRNA. These leukemic dendritic cells may enhance the induction and proliferation of CTL lines and clones with more specificity for the leukemic cells.     

Cell kinetics and diagnosis of residual disease of a tumor in bone marrow

Cell-cycle studies of bone marrow do not allow the detection of minimal residual disease in lymphoma or carcinoma. However, cell kinetics in acute myeloid leukemia may be a predictive test for relapse. Detection of minimal residual disease is all the more difficult that leukemic blast cells can differentiate to form mature cells.     

Allogeneic hematopoietic stem cell transplantation: state of the art and new perspectives

Allogeneic hematopoietic stem cell transplantation (ASCT) is a well-established therapy for leukemias and other immunohematopoietic disorders. In more recent years, bone marrow as stem cell source has been replaced by peripheral blood stem cells, which results in faster engraftment. Cord blood grafts are increasingly used. Conditioning prior to transplant may be myeloablative or nonmyeloablative. The latter is used preferentially in patients with high age or organ impairment. Isolation in the hospital during posttransplant pancytopenia has been challenged by promising results using home care. PCR diagnosis and new antifungal and antiviral treatment have reduced morbidity and mortality. The major threat to a successful outcome after ASCT is leukemic relapse. PCR techniques to detect recipient cells in the leukemic cell lineage or minimal residual disease enable early detection of leukemic cells. Donor lymphocyte infusions have an antileukemic effect. ASCT has shown an antitumor effect in metastatic cancers from breast, kidney, colon, ovaries, prostate and pancreas. Mesenchymal stem cells may be derived from bone marrow and have the capacity to differentiate into several mesenchymal tissues, such as bone, cartilage and fat. They seem to escape the immune system and have immunomodulatory effects in vitro and in vivo. To conclude, ASCT is a potent immunotherapy.     

生物蛋白胶复合骨髓间充质干细胞修复兔多层软组织缺损

背景：符合软组织生理结构的生物蛋白胶适合作为修复软组织缺损的载体材料。 目的：观察生物蛋白胶复合骨髓间充质干细胞修复软组织缺损的可行性。 方法：在新西兰大白兔大腿处造成深达肌肉层,直径大于3 cm的软组织缺损。将24只新西兰大白兔随机分为3组,实验组将同种异体来源的骨髓间充质干细胞复合生物蛋白胶注射到软组织缺损处,对照组将生物蛋白胶注射到软组织缺损处,模型组造模后不注射。 结果与结论：术后14,21 d创面收缩率,实验组>对照组>模型组(P < 0.01);愈合时间,实验组<对照组<模型组(P < 0.01)。结果显示以生物蛋白胶为载体复合骨髓间充质干细胞能快速的修复多层软组织缺损。     

The biologic significance of rare peripheral blasts after hematopoietic cell transplantation is predicted by multidimensional flow cytometry.

A vexing problem after hematopoietic cell transplantation (HCT) for leukemia is assessing the biologic significance of low numbers of cells "suspicious" for relapse seen in morphologic review of peripheral blood smears (PBSs). In 27 patients, in apparent hematologic remission after HCT for leukemia, we studied the nature of such cells in PBSs to the endpoint of leukemic relapse by using multidimensional flow cytometry (MDF) on blood or bone marrow aspirates. Based on abnormal cytometric maturational patterns, +/- cell sorting of blasts with fluorescence in situ hybridization with informative markers, we differentiated benign recovering myeloid and lymphoid precursors from leukemic cells. In 17 patients, blasts were characterized by MDF as normal early hematopoietic precursors, lymphoblasts, or NK cells. Of these patients, 16 remained in remission for at least 42 days. In 10 patients, blasts were characterized by MDF as a malignant immunophenotype; 9 relapsed within 10 days and 1 relapsed 280 days after a graft-vs-leukemia effect. MDF status was strongly associated with a 90 x probability of relapse even after adjusting for other potential variables. Morphologic triggered MDF characterization of peripheral blasts is a powerful and rapid tool for distinguishing immature regenerative forms from early leukemic relapse.     

Platelet-derived growth factor gene delivery stimulates ex vivo gingival repair

Destruction of tooth support due to the chronic inflammatory disease periodontitis is a major cause of tooth loss. There are limitations with available treatment options to tissue engineer soft tissue periodontal defects. The exogenous application of growth factors (GFs) such as platelet-derived growth factor (PDGF) has shown promise to enhance oral and periodontal tissue regeneration. However, the topical administration of GFs has not led to clinically significant improvements in tissue regeneration because of problems in maintaining therapeutic protein levels at the defect site. The utilization of PDGF gene transfer may circumvent many of the limitations with protein delivery to soft tissue wounds. The objective of this study was to test the effect of PDGF-A and PDGF-B gene transfer to human gingival fibroblasts (HGFs) on ex vivo repair in three-dimensional collagen lattices. HGFs were transduced with adenovirus encoding PDGF-A and PDGF-B genes. Defect fill of bilayer collagen gels was measured by image analysis of cell repopulation into the gingival defects. The modulation of gene expression at the defect site and periphery was measured by RT-PCR during a 10-day time course after gene delivery. The results demonstrated that PDGF-B gene transfer stimulated potent (>4-fold) increases in cell repopulation and defect fill above that of PDGF-A and corresponding controls. PDGF-A and PDGF-B gene expression was maintained for at least 10 days. PDGF gene transfer upregulated the expression of phosphatidylinosital 3-kinase and integrin alpha5 subunit at 5 days after adenovirus transduction. These results suggest that PDGF gene transfer has potential for periodontal soft tissue-engineering applications.     

The genomic breakpoint in a patient with Philadelphia-positive acute leukemia is 5' of the breakpoint cluster region

We report a case of acute leukemia in which studies at presentation showed both myeloid and lymphoid cell surface markers. At relapse membrane markers studies were consistent with a leukemia of B-lymphoid lineage. However, immunoglobulin (Ig) and T cell receptor (TCR) beta chain genes were both found in a rearranged configuration. The majority of metaphases from the leukemic cells at presentation showed the Philadelphia chromosome, t(9;22)(q34;q11), whereas a minority were normal. At relapse both Ph-positive and -negative metaphases were still present in the bone marrow but some of the Ph-negative metaphases had acquired an additional chromosome #19 [47,XY, + 19]. Southern analysis of DNA from leukemic bone marrow cells at diagnosis showed no rearrangement of breakpoint cluster region (bcr). There was no bcr-abl chimeric mRNA typical of Ph-positive chronic myeloid leukemia (CML). However, the cells expressed an abl-related protein of Mr 190 kd with enhanced tyrosine kinase activity. Leukemic cell metaphases were studied by the technique of in situ hybridization with probes for C-lambda, sis, abl, and 5' bcr. The c-abl probe mapped to chromosome 22q11 in Ph-positive metaphases. The 5' bcr probe mapped to 9q+ in the Ph-positive metaphases and the C-lambda gene mapped to the Ph chromosome. Thus, the genomic breakpoint in this patient must lie upstream of the BCR defined by study of Ph-positive CML and downstream of the C-lambda gene locus. We speculate that the Ph-negative cells in this patient may represent a leukemic proliferation susceptible to acquisition of specific chromosomal changes.     

Mosasaurs and snakes have a periodontal ligament: timing and extent of calcification,not tissue complexity,determines tooth attachment mode in reptiles

Squamates present a unique challenge to our understanding of dental evolution in amniotes because they are the only extant tooth‐bearing group for which a ligamentous tooth attachment is considered to be absent. This has led to the assumption that mammals and crocodilians have convergently evolved a ligamentous tooth attachment, composed of root cementum, periodontal ligament, and alveolar bone, whereas squamates are thought to possess a single bone of attachment tissue that fuses teeth to the jaws. The identity and homology of tooth attachment tissues between squamates, crocodilians, and mammals have thus been a focal point of debate for decades. We provide a novel interpretation of the mineralized attachment tissues in two focal taxa in this debate, mosasaurids and snakes, and compare dental tissue histology with that of the extant crocodilian Caiman sclerops. We identify a periodontal ligament in these squamates that usually exists temporarily as a soft connective tissue anchoring each tooth to the alveolar bone. We also identify two instances where complete calcification of the periodontal ligament does not occur: in a durophagous mosasaur, and in the hinged teeth of fossil and modern snakes. We propose that the periodontal ligament rapidly calcifies in the majority of mosasaurids and snakes, ankylosing the tooth to the jaw. This gives the appearance of a single, bone‐like tissue fusing the tooth to the jaw in ankylosed teeth, but is simply the end stage of dental tissue ontogeny in most snakes and mosasaurids.