Macrophages (phagocytic-histiocytic reticular cells) in reactive-inflammatory lesions of the bone marrow and in myelodysplastic syndromes (MDS). An immunohistochemical and morphometric study by use of a new monoclonal antibody (PG-M1).

An immunohistochemical and morphometric study was performed on trephine biopsies of the bone marrow in 52 patients (28 males/24 females; age 68 years) with various subtypes of myelodysplastic syndromes (MDS) to determine the number of macrophages (phagocytic-histiocytic reticular cells). Quantifications included the haemosiderin-storing subpopulation (Prussian-blue reaction) of this lineage as well as the iron-free compartment. The latter was identified by a new monoclonal antibody (PG-M1) which is specifically directed against histiocytic reticular cells. Bone marrow specimens of individuals without haematological disorders and those showing reactive lesions served as controls. In comparison with the normal bone marrow and inflammatory changes (i.e. rheumatoid arthritis) 23 of the 52 patients with MDS revealed a significant increase in macrophages. This increase encompassed not only the iron-laden subpopulation but also the total number of phagocytic reticular cells. Accumulation of macrophages in MDS was speculated to be due to a premature and enforced degradation of dysplastic cell elements leading to phagocytosis of haemosiderin and debris material. Moreover, cells of the monocyte-macrophage system could be involved in the complex pathomechanism of fibrillogenesis, since in a considerable percentage of patients with MDS, an increase in reticulin (argyrophilic) fibres was noticeable. Our finding of an expansion of the macrophage compartment in about half of the patients with MDS is in keeping with results of cell culture studies on colony formation of granulocyte-macrophage precursors (CFU-GM).     

The immunohistochemical reactivity of a new anti-epithelial monoclonal antibody (MAb b-12) against breast carcinoma and other normal and neoplastic human tissues

Summary A mouse monoclonal antibody, MAb b-12, has been described previously (Stähli et al. 1985) which reacts with a M_r 350 kD glycoprotein with mucin-like characteristics (Stähli et al. 1987) expressed in cytoplasm and on the surface of human breast carcinoma cell lines (MCF-7 and ZR-75-1). In the present report the immunohistochemical reactivity of this MAb with normal and malignant human tissues is analyzed. Pre-experiments showed that the epitope b-12 is resistant to formalin treatment allowing the use of tissue processed by standard paraffin embedding methods. 167 normal and 408 neoplastic tissues were tested by indirect immunofluorescence or the avidin-biotin complex method. MAb b-12 stained the apical cytoplasm of secretory epithelia and their secretions including the acinar and ductular epithelia of the breast. It reacted with all breast carcinomas independent of their histological type or stage, frequently with all but in some cases with a fraction of the tumour cells. Some other carcinomas, primarily those of adenomatous differentiation, were also reactive. In these, however, the fraction of positive tumour cells was usually lower. The b-12 epitope is thus a marker for normal and neoplastic epithelia with secretory functions, particularly for breast carcinomas of all histological types and stages, and perhaps a differentiation marker for abortive adenomatous differentiation in solid carcinomas of the gastro-intestinal, uro-genital or respiratory tract.     

Histomorphometry of bone marrow biopsies in chronic myeloproliferative disorders with associated thrombocytosis - features of significance for the diagnosis of primary (essential) thrombocythaemia

Summary A histomorphometric analysis was performed on trephine biopsies of the bone marrow in 55 patients with chronic myeloproliferative disorders (CMPDs) and marked thrombocytosis (platelet count exceeding 600 × 10⁹/l). This study aimed at discriminating primary (essential) thrombocythaemia (PTH) from the various other subtypes of CMPDs presenting with thrombocytosis. Following the diagnostic requirements postulated by the Polycythemia-vera-Study-Group for PTH and polycythaemia vera rubra (P.vera) and the generally accepted criteria for the establishment of chronic myeloid leukaemia (CML) and agnogenic myeloid metaplasia (AMM), our cohort of 55 patients was divided into the following subgroups: CML (16 cases), P.vera (11 cases), AMM (13 cases) and finally PTH (15 cases). Histomorphometric measurements revealed that PTH was distinguishable from the other subtypes of CMPDs with respect to several histological variables: patients with PTH had a normal amount of neutrophilic granulo- and erythrocytopoiesis as well as a non-increased content of reticulin (argyrophilic) fibers in contrast to the findings in CML, P.vera and of course AMM. Moreover, sizes of megakaryocytes and their nuclei were significantly greater in PTH and internalization of haematopoietic cells (emperipolesis) was more frequently encountered in comparison with the other subtypes of CMPDs. Deviation of the circular perimeter of megakaryocyte shape was most prominently expressed in CML and AMM, and consequently generated an increased number of a-nuclear cytoplasmic fragments. In contrast to this feature aberration of the nuclei from a circular outline occurred in a less pronounced way in CML, but was excessive in P.vera, AMM and PTH. Our morphometric evaluation demonstrates that certain histological features may serve as a valuable aid in discriminating PTH from the other occasionally thrombocythaemic subtypes of CMPDs.Supported by a grant from the Moritz Foundation, Cologne, Federal Republic of Germany     

Follicular dendritic cells in bone marrow lymphoproliferative diseases: an immunohistochemical study including a new paraffin-resistant monoclonal antibody, DR53

Two-hundred and twenty-one bone marrow biopsies with lymphoid infiltrates were studied histologically and immunohistochemically, to assess the incidence and the pattern of follicular dendritic cells. Three monoclonal antibodies selective for follicular dendritic cells were used: CD21, CD35 and DR53, all reactive on paraffin-embedded material. Follicular dendritic cells were present in two of 38 benign lymphoid aggregates, 92 of 134 low grade B-cell lymphomas (45 of 62 lymphocytic, 16 of 27 lymphoplasmacytoid, 0 of six hairy cell leukaemias, five of six centrocytic, 19 of 21 centroblastic-centrocytic, seven of 12 low grade NOS), one of 23 high grade B-cell lymphomas, 0 of 10 T-cell lymphomas, 0 of three Hodgkin's disease and four of 13 suspicious infiltrates. Follicular dendritic cells were found in lymphomatous involvement with nodular, patchy and massive growth pattern, but not in interstitial ones. They formed follicle-like networks, whose number and size were directly correlated to the tumour mass. The origin and frequency distribution of follicular dendritic cells in bone marrow biopsy lymphomas is discussed and the diagnostic relevance of follicular dendritic cell immunostaining in routine bone marrow biopsy lymphoid infiltrates is assessed.     

A study of cell proliferation in formalin-fixed, wax-embedded bone marrow trephine biopsies using the monoclonal antibody PC10, reactive with proliferating cell nuclear antigen (PCNA).

We have investigated proliferation in bone marrow trephine biopsies from 32 patients with normal or abnormal haemopoiesis, using the monoclonal antibody PC10, which detects proliferating cell nuclear antigen (PCNA), together with immunohistochemical markers of haemopoietic cell lineage. PCNA immunostaining revealed the pattern of proliferation within individual haemopoietic lineages in normal marrow. Two unexpected observations were made: of erythroid cells, only pro-erythroblasts and occasional early normoblasts reacted, and positivity of megakaryocytes was unrelated to nuclear lobulation or CD61 expression. The pathological cases represented conditions in which haemopoiesis is increased (reactive hyperplasia, chronic granulocytic leukaemia, myeloproliferative and myelodysplastic syndromes, megaloblastic anaemia). Increases in the number, and disturbances of the spatial organization, of PCNA-expressing cells were present to a variable extent in all cases. Sheets of PCNA-positive megaloblastoid erythrocytes were frequently found in myelodysplastic and myeloproliferative tissue, associated with marked disturbances in the spatial organization of all haemopoietic lineages. Cases of megaloblastic anaemia due to vitamin B12/folate deficiency also demonstrated greatly increased erythroid PCNA expression, with positivity in some giant metamyelocytes. In addition to reflecting increased proliferation, elevated PCNA expression in some bone marrow pathologies may be due to altered kinetics of the protein induced by disturbances in growth factor production.     

Identification of basogranulin (BB1) as a novel immunohistochemical marker of basophils in normal bone marrow and patients with myeloproliferative disorders

In myeloproliferative disorders (MPDs), basophils typically increase in number in the bone marrow (BM) and blood. In chronic myeloid leukemia (CML), basophilia is a diagnostic and prognostic variable. However, no reliable approach for routine detection and enumeration of basophils in BM sections is available. We applied the antibasogranulin antibody BB1 on paraffin-embedded BM sections in 21 control samples (normal BM), 45 patients with CML, 9 with chronic idiopathic myelofibrosis, 11 with polycythemia vera, 19 with essential thrombocythemia, and 7 with indolent systemic mastocytosis. As assessed by immunostaining of serial BM sections, BB1+ cells coexpressed myeloperoxidase, histidine decarboxylase, and leukosialin but did not express B- or T-cell-restricted antigens. BB1+ BM cells were found to be highly elevated in patients with CML compared with normal BM or other MPDs, with maximum counts found in accelerated phase CML (median, 160 cells/mm(2)). In summary, BB1 (basogranulin) is a new immunohistochemical basophil marker that should allow quantification of basophils in CML at diagnosis and during therapy.     

Frequent detection of the JAK2 V617F mutation in bone marrow core biopsy specimens from chronic myeloproliferative disorders using the TaqMan polymerase chain reaction single nucleotide polymorphism genotyping assay: a retrospective study with pathologic correlations

A retrospective investigation of the JAK2 V617F mutation was carried out in DNA samples from 131 bone marrow (BM) core biopsy specimens corresponding to patients with polycythemia vera (PV) (n = 31), essential thrombocythemia (ET) (n = 31), chronic idiopathic myelofibrosis (CIM) (n = 18), as well as patients with normal BM and secondary reactive hyperplasia. We used the TaqMan polymerase chain reaction single nucleotide polymorphism genotyping assay to detect the specific JAK2 mutation. This technique allowed us to detect the JAK2 V617F mutation in a population containing at least 5% of homozygous mutants. Overall, the incidence of the JAK2 V617F mutation was 87% in PV, 67% in ET, and 66% in CIM. This approach proved to be reliable and more sensitive in detecting the mutation compared with that of initial studies on different materials but similar to that of recent work with various polymerase chain reaction-based techniques. Two essential findings arose from our study. First, this technique could be carried out with DNA samples, even partially degraded, from routinely processed BM core biopsy specimens. Second, after correlation with morphological features, it turned out that the characteristics of the megakaryocytes were more specific than the mutational status of JAK2 in characterizing ET and CIM. Concerning PV, as expected, the incidence of the JAK2 mutation was higher, but the morphological criteria were misleading in some cases, strongly suggesting that the combination of both histologic and molecular data would enable the characterization of virtually all cases.     

HLA高分辨等位基因与骨髓移植受者HCMV抗原血症研究

目的 分析HLA高分辨等位基因与骨髓移植术后HCMVpp65抗原血症的相关性.方法 选取2009年2月至2010年10月在我院行骨髓移植术患者48例;采用免疫组化方法检测患者HCMVpp65,采用直接测序分型方法（PCR-SBT）检测患者HLA-A＊1101、HLA-A＊0201、HLA-A＊2402、HLA-B＊4001、HLA-DRB1＊0901五个高分辨等位基因.结果 ①48例骨髓移植术后患者HCMV感染率100％;②HLA-A＊1101、HLA-A＊0201、HLA-A＊2402、HLA-B＊ 4001等位基因阳性率在pp65抗原血症12例低感染组和36例高感染组中比较没有统计学意义（P＞0.05）,其阳性率HLA-A＊1101为33.3％ （8/24）和20.8％ （15/72）、HLA-A＊0201为4.2％ （1/24）和13.9％ （10/72）、HLA-A＊ 2402为12.5％ （3/24）和19.4％ （14/72）、HLA-B＊ 4001 16.7％ （4/24）和12.5％ （9/72）;③HLA-DRB1＊0901等位基因阳性率在pp65抗原血症12例低感染组和36例高感染组中比较有统计学意义（P =0.048）,其阳性率为4.2％ （1/24）和19.4％ （14/72）;④HLA-DRB1＊0901组患者pp65抗原血症高于HLA-A＊2402组（P =0.007）和HLA-A＊1101组患者（P=0.028）,HLA-A＊0201组患者pp65抗原血症高于HLA-A＊2402组患者（P=0.02）,其他高分辨等位基因组之间pp65抗原血症差异没有统计学意义（P＞0.05）.结论 HLA-DRB1＊0901等位基因可能与骨髓移植术后患者发生高HCMVpp65抗原血症有关;HLA-A＊2402等位基因可能与骨髓移植术后患者发生低HCMVpp65抗原血症有关.     

A new mouse anti-mouse complement receptor type 2 and 1 (CR2/CR1) monoclonal antibody as a tool to study receptor involvement in chronic models of immune responses and disease

Although reagents are available to block mouse complement receptor type 2 and/or type 1 (CR2/CR1, CD21/CD35) function in acute or short term models of human disease, a mouse anti-rat antibody response limits their use in chronic models. We have addressed this problem by generating in Cr2−/− mice a mouse monoclonal antibody (mAb 4B2) to mouse CR2/CR1. The binding of murine mAb 4B2 to CR2/CR1 directly blocked C3dg (C3d) ligand binding. In vivo injection of mAb 4B2 induced substantial down regulation of CR2 and CR1 from the B cell surface, an effect that lasted six weeks after a single injection of 2 mg of mAb. The 4B2 mAb was studied in vivo for the capability to affect immunological responses to model antigens. Pre-injection of mAb 4B2 before immunization of C57BL/6 mice reduced the IgG1 antibody response to the T-dependent antigen sheep red blood cells (SRBC) to a level comparable to that found in Cr2−/− mice. We also used the collagen-induced arthritis (CIA) model, a CR2/CR1-dependent autoimmune disease model, and found that mice pre-injected with mAb 4B2 demonstrated substantially reduced levels of pathogenic IgG2a antibodies to both the bovine type II collagen (CII) used to induce arthritis and to endogenous mouse CII. Consistent with this result, mice pre-injected with mAb 4B2 demonstrated only very mild arthritis. This reduction in disease, together with published data in CII-immunized Cr2−/− mice, confirm both that the arthritis development depends on CR2/CR1 receptors and that mAb 4B2 can be used to induce biologically relevant receptor blockade. Thus mAb 4B2 is an excellent candidate for use in chronic murine models to determine how receptor blockage at different points modifies disease activity and autoantibody responses.     

An immunocytochemical study of the distribution of lysozyme,a1-antitrypsin and a1-antichymotrypsin in the normal and pathological gall bladder

Summary We have studied the distribution of lysozyme (Ly), a₁-antitrypsin (a₁AT) and a₁-antichymotrypsin (a₁AChy) in the normal, chronically inflamed and neoplastic gall bladder mucosa using the peroxidase-anti-peroxidase (PAP) method. Ly was absent from the normal mucosa but it was found only in areas of glandular metaplasia of true antral type and in crypts of possible early metaplastic nature in cases of chronic cholecystitis. a₁AT and a₁AChy were also found in such metaplastic areas, but their presence was also observed immunohistochemically in areas of essentially normal and in non-metaplastic, chronically inflamed gall bladder mucosa. The possible local production of these substances by gall bladder epithelial cells is discussed. Ly, a₁AT and a₁AChy were also found in various histological types of adenocarcinoma of the gall bladder in varying degrees of frequency and intensity, unrelated to the histological type and invasiveness of the tumour.     

Therapy-related changes of CD20+ and CD45RO+ lymphocyte subsets in chronic myeloid leukemia (CML): an immunohistochemical and morphometric study on sequential trephine biopsies of the bone marrow.

Little information exists about the amount of CD45RO+-T- and CD20+-B-lymphocytes in the bone marrow of patients with Philadelphia chromosome-positive chronic myelogenous leukemia (Ph1+-CML) at presentation or regarding corresponding changes during therapy. On the other hand, quantification of this cell compartment seems to be imperative for two reasons: first, the presumed association of immunocompetent lymphocyte subsets in the expansion of the leukemic cell clone; and second, a speculated relationship with the complex generation of myelofibrosis. Therefore, an immunohistological and morphometric study was performed on 219 representative trephine biopsies of the bone marrow derived from 70 patients with repeated examinations during the course of Ph1+-CML. For the identification of the different lymphocyte populations, the monoclonal antibodies UCHL-1 (CD45RO) and L26 (CD20) were applied on formaldehyde-fixed and decalcified specimens. In comparison to a control group and calculated per hematopoietic cells, the CML bone marrow showed about a 50% decrease in the total amount of lymphocytes. Determination of CD45RO+ and CD20+ subsets revealed a significant enhancement during treatment. Because of the different intervals (range, 10 to 25 mo) between first and last biopsy in the various therapeutic groups, results had to be modified by considering dynamic features. This calculation included changes of the lymphocyte subpopulations related to time. Contrasting the CD45RO+ lymphocytes, a relevant increase in the CD20+ subset could be observed after interferon-a treatment or corresponding combination regimens. No significant correlations were found between fiber density at onset (first biopsy) or development of fibrosis and lymphocyte proliferations in the course of CML. Our results are in keeping with the finding that a proper immune response consistent with an increased lymphocyte growth seems to be associated with a regression of the clonally-transformed cell population. Opposed to a repeatedly discussed pathomechanism, we failed to demonstrate any quantitative relationships between the extent of lymphocyte proliferations and occurrence or progression of myelofibrosis.     

Expression of BAFF-R (BR3) in normal and neoplastic lymphoid tissues characterized with a newly developed monoclonal antibody

BAFF-receptor (BAFF-R) is required for the successful maturation and survival of B-cells. We developed an anti-human BAFF-R monoclonal antibody (mAb), 8A7. The reactivity of 8A7 in normal and neoplastic tissue was examined by performing immunohistochemistry on paraffin-embedded sections. 8A7 reacted with lymphocytes in the mantle and marginal zones, but not with lymphocytes in the interfollicular area. Lymphocytes in the germinal centers were found to be negative or occasionally weakly positive for 8A7. BAFF-R expression was found only in B-cell lymphoma (44/80, positive cases/examined cases): B-lymphoblastic lymphoma 0/3, B-chronic lymphocytic leukemia/small lymphocytic lymphoma 4/4, mantle cell lymphoma 9/11, follicular lymphoma 10/14, diffuse large B-cell lymphoma (DLBCL) 11/25, marginal zone B-cell lymphoma 8/10, lymphoplasmacytic lymphoma 2/2, plasma cell myeloma 0/2, and Burkitt lymphoma 0/9, but not in T/NK cell lymphomas (0/19) or Hodgkin lymphoma (0/10). BAFF-R was expressed in most low-grade B-cell neoplasms and a small number of DLBCL, suggesting that BAFF-R may play an important role in the proliferation of neoplastic lymphoid cells. Thus, the mAb is very useful for further understanding of both healthy B-cell biology and its pathogenic neoplasms.     

5'-RACE法扩增抗人乳头瘤病毒16型L1蛋白单克隆抗体轻链可变区基因及序列分析

目的 获得抗人乳头瘤病毒16型(HPV16)L1蛋白单克隆抗体的轻链可变区(VL)基因并分析序列.方法 从分泌抗HPV16L1蛋白单克隆抗体的杂交瘤细胞中提取总RNA,逆转录形成cDNA,用5'-RACE策略扩增抗体轻链可变区基因,经琼脂糖凝胶电泳鉴定,并测序及进行序列分析.结果 VL基因全长336bp,编码112个氨基酸,基因测序结果符合小鼠抗体轻链可变区特征.结论 5'-RACE法成功获得了抗HPV16L1蛋白的单克隆抗体轻链可变区基因的真实序列,为基因工程抗体研究奠定了良好基础.     

Reactivity of a humanized antibody (hPankoMab) towards a tumor-related MUC1 epitope (TA-MUC1) with various human carcinomas

Humanized antibodies against tumor-related antigens are now established reagents for in vivo diagnostics and for therapeutic approaches, and are increasingly developed. Humanized PankoMab (hPankoMab), a humanized form of PankoMab directed against a novel tumor-related MUC1 epitope (TA-MUC1), was recently developed for clinical application. In the present study, the reactivity of hPankoMab with various human cancers was systematically studied by immunohistochemistry on 137 surgical specimens, including lung, breast, gastric, colorectal, liver, cervical, kidney, thyroid, and other carcinomas, as well as on several non-epithelial malignancies. The study was performed on paraffin sections without antigen retrieval. hPankoMab reacted strongly with carcinomas originating from glandular or squamous epithelia, weakly with hepatocellular carcinomas, and not with sarcomas. The binding sites of hPankoMab in carcinomas were found around the whole cell surface and, in most cases, also in the cytoplasm of cancer cells.     

Preparation of F(ab′)2 fragments from monoclonal mouse IgG1 suitable for use in radioimaging

Monoclonal antibodies of IgG1 subclass raised against purified human prostate-specific acid phosphatase were subjected to different procedures to produce F(ab′)₂ fragments suitable for radioimaging of prostatic cancer, following derivatization and labeling with radionuclides. The main aim was to obtain highly purified fragments with preserved immunological activity. Optimized pepsin digestion led to the formation of mainly F(ab′)₂ and Fab fragments, and, following Sephacryl S-200 gel filtration, the yield of pure F(ab′)₂ fragments was 24 ± 11% of the theoretical maximum. After papain digestion in the absence of thiols, no formation of Fab fragments was observed, and the F(ab′)₂ fragments formed could be efficiently separated from Fc fragments by chromatofocusing or ion exchange chromatography. The yield of F(ab′)₂ fragments from papain digestion was 50 ± 5% of the theoretical maximum. Both the above procedures gave F(ab′)₂ fragments with immunoreactivity and affinity identical to those of the precursor IgG1, despite the fact that isoelectric focusing profiles of the two F(ab′)₂ preparations differed, suggesting different digestion sites.     

Generation and characterization of new monoclonal antibodies against swine origin 2009 influenza A (H1N1) virus and evaluation of their prophylactic and therapeutic efficacy in a mouse model

In 2009, a swine-origin influenza A virus – A(H1N1)pdm09 – emerged and has became a pandemic strain circulating worldwide. The hemagglutinin (HA) of influenza virus is a potential target for the development of anti-viral therapeutic agents. Here, we generated mAbs by immunization of baculovirus-insect expressing trimeric recombinant HA of the A(H1N1)pdm09 strain. Results indicated that the mAbs recognized two novel neutralizing and protective epitopes-“STAS” and “FRSK” which located near Cb and Ca1 antigenic regions respectively and were conserved in almost 2009–2016 influenza H1N1 stains. The mAb 12E11 demonstrated higher protective efficacy than mAb 8B10 in mice challenge assay. Both mAb pretreatments significantly reduced virus titers and pro-inflammatory cytokines in mice lung postinfection (p < 0.01), and showed prophylactic and therapeutic efficacies even 48 h postinfection (p < 0.05). Combination therapy using the mAbs with oseltamivir pre- and post-treatment showed synergistic therapeutic effect in mice model (p < 0.01). Further investigation for clinical application in humans is warranted.     

Cytological examination and cellular composition of bone marrow in healthy, adult, cynomolgus monkeys (Macaca fascicularis)

The purpose of this study was to evaluate the cellular composition of the bone marrow of cynomolgus monkeys (Macaca fascicularis). Femoral bone marrow smears from 23 healthy, adult animals (11 males and 12 females) were examined. For each animal, three femoral bone marrow smears were prepared immediately after euthanasia and stained with May-Grünwald-Giemsa. On two of the three smears available, and for each of these smears, a 500-cell differential count was performed and the myeloid: erythroid (M:E) ratio established. The M:E ratio for males varied from 0.67∶1.00 to 1.85∶1.00 with a mean of 1.03∶1.00 and for females from 0.67∶1.00 to 1.63∶1.00 with a mean of 1.02∶1.00. The mean percentage of granulocytic, lymphocytic, plasmacytic and erythroid series was 47.60, 5.44, 1.45 and 46.05% for males and 47.28, 5.12, 1.49 and 46.28% for females. No significant differences were noted between males and females. All cell lines were well represented and showed normal maturation in both sexes. Megakaryocytes were adequate in number and morphology in all animals. Cynomolgus monkeys showed a bone marrow composition similar to rhesus monkeys (Macaca mulatta). Cytological examination of bone marrow was found to be a simple and rapid procedure, well suited to the toxicological research environment. It provided excellent information on cell distribution, morphology and maturation of the haematopoietic system.     

The urokinase plasminogen activator (u-PA) and its inhibitor (PAI-1) in embryo-fetal bone formation in the human: an immunohistochemical study

The role of urokinase plasminogen activator and plasminogen activator inhibitor-1 in human embryofetal bone formation between the 9th and the 20th week of gestation has been studied immunohistochemically. While mature osteocytes of the secondary spongiosa and resting chondrocytes of the bone epiphyses were negative for both antigens in each developmental stage, metabolically active parts of the osseocartilaginous system showed a strong immunoreactivity. Until the end of the 10th week of gestation urokinase plasminogen activator and plasminogen activator inhibitor-1 could not be demonstrated in the shaft of the preexisting cartilaginous models of bones, which correlates with the morphological developmental stage of the embryos. Later, osteoblasts and chondrocytes in the areas of enchondral ossification, and the perivascular chondrocytes of the epiphyseal secondary ossification centres, showed similarly high concentrations of urokinase plasminogen activator and plasminogen activator inhibitor-1. Moreover, the individual ossification stages of the different bones in embryo-fetal development could be demonstrated immunohistochemically. While humeri and femora showed diaphyseal immunoreactivities at an early stage, positive reactions in the phalanges were found only much later. Thus, the enzymes of the fibrinolytic system studied are clearly involved in the desmal and enchondral ossification process in the osseocartilaginous compartment.     

Enhancement of bone regeneration by dual release of a macrophage recruitment agent and platelet-rich plasma from gelatin hydrogels

Macrophages play an important role in regulating inflammatory responses and tissue regeneration. In the present study, their effect on bone remodeling is investigated by the simultaneous application of a macrophage recruiting agent, SEW2871 of a sphingosine-1 phosphate agonist, and platelet-rich plasma (PRP). The non-water soluble SEW2871 was solubilized in water through micelles formation with l-lactic acid grafted gelatin, and the resulting micelles with PRP were incorporated into gelatin hydrogels. Mixed SEW2871-micelles and PRP were released from gelatin hydrogels in a controlled fashion both in vitro and in vivo. In vitro migration assay revealed that the presence of PRP synergistically promoted SEW2871-induced macrophages migration. When applied to a bone defect of rats, the hydrogels incorporating mixed SEW2871-micelles and PRP recruited a higher number of macrophages than those hydrogels incorporating either SEW2871-micelles or PRP. The hydrogels incorporating mixed SEW2871-micelles and PRP enhanced the level of tumor necrosis factor (TNF)-α of pro-inflammatory cytokine, 3 days after application, while pro-inflammatory responses coupled with a significant increase in the expression level of osteoprotegerin (OPG) and interleukin (IL)-10 and transforming growth factor (TGF)-β₁ of anti-inflammatory cytokine were observed 10 days postoperatively. The hydrogels incorporating mixed SEW2871-micelles and PRP promoted bone regeneration to a significant great extent compared with those incorporating PBS and either SEW2871-micelles or PRP. It is concluded that macrophages recruitment contributed to PRP-induced bone regeneration.     

Influence of bone marrow hexapeptides (myelopeptides) on antibody production and algesthesia in mice and the dependence of these effects on naloxone

It is shown that synthetic analogs of two bone marrow hexapeptides (myelopeptides 1 and 2), which are identical in structure to the N-terminal peptide fragments of hemoglobin α- and β-chains, are characterized by naloxone-independent antibody-stimulating activity. The antibody-stimulating effect of the myelopeptides becomes naloxone-dependent and stronger against the background of immunosuppression provoked by the hot plate test carried out before immunization. Intraperitoneal administration of both myelopeptides in doses of 10⁻¹³–10⁻⁸ g/mouse causes a naloxone-dependent modulatory effect on mouse algesthesia threshold with a predominant analgetic effect. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 119, No 4, pp. 413–416, April, 1995 Presented by R. V. Petrov, Member of the Russian Academy of Medical Sciences