[Patient-reported outcomes of locally advanced gastric cancer undergoing robotic versus laparoscopic gastrectomy: a randomized controlled study]

Objective: To compare the patient-reported outcomes and short-term clinical outcomes between robotic-assisted and laparoscopic-assisted radical gastrectomy for locally advanced gastric cancer. Methods: This single-center prospective randomized controlled trial was conducted in the Department of Gastrointestinal Surgery,Affiliated Hospital of Qingdao University from October 2020 to August 2022. Patients with locally advanced gastric cancer who were to undergo radical gastrectomy were selected and randomly divided into two groups according to 1∶1, and received robotic surgery and laparoscopic surgery, respectively. Patient-reported outcomes and short-term clinical outcomes (including postoperative complications, surgical quality and postoperative short-term recovery) were compared between the two groups by t test, Mann-Whitney U test, repeated ANOVA, generalized estimating equation, χ2 test and Fisher's exact test. Results: A total of 237 patients were enrolled for modified intention-to-treat analysis (120 patients in the robotic group, 117 patients in the laparoscopic group). There were 180 males and 59 females, aged (63.0±10.2) years (range: 30 to 85 years). The incidence of postoperative complications was similar between the robotic group and laparoscopic group (16.7% (20/120) vs. 15.4% (18/117), χ2=0.072, P=0.788). The robotic group had higher patient-reported outcomes scores in general health status, emotional, and social domains compared to the laparoscopic group, differences in time effect, intervention effect, and interaction effect were statistically significant (general health status: χ2 value were 275.68, 3.91, 6.38, P value were <0.01, 0.048, 0.041; emotional: χ2 value were 77.79, 6.04, 6.15, P value were <0.01, 0.014, 0.046; social: χ2 value were 148.00, 7.57, 5.98, P value were <0.01, 0.006, 0.048). However, the financial burden of the robotic group was higher, the differences in time effect, intervention effect and interaction effect were statistically significant (χ2 value were 156.24, 4.08, 36.56, P value were<0.01, 0.043,<0.01). Conclusion: Compared to the laparoscopic group, the robotic group could more effectively relieve postoperative negative emotions and improve recovery of social function in patients.

Depletion of microglia with PLX3397 attenuates MK-801-induced hyperactivity associated with regulating inflammation-related genes in the brain

Acute administration of MK-801 (dizocilpine), an N-methyl-D-aspartate receptor (NMDAR) antagonist, can establish animal models of psychiatric disorders. However, the roles of microglia and inflammation-related genes in these animal models of psychiatric disorders remain unknown. Here, we found rapid elimination of microglia in the prefrontal cortex (PFC) and hippocampus (HPC) of mice following administration of the dual colony-stimulating factor 1 receptor (CSF1R)/c-Kit kinase inhibitor PLX3397 (pexidartinib) in drinking water. Single administration of MK-801 induced hyperactivity in the open-field test (OFT). Importantly, PLX3397-induced depletion of microglia prevented the hyperactivity and schizophrenia-like behaviors induced by MK-801. However, neither repopulation of microglia nor inhibition of microglial activation by minocycline affected MK-801-induced hyperactivity. Importantly, microglial density in the PFC and HPC was significantly correlated with behavioral changes. In addition, common and distinct glutamate-, GABA-, and inflammation-related gene (116 genes) expression patterns were observed in the brains of PLX3397- and/or MK-801-treated mice. Moreover, 10 common inflammation-related genes ( CD68, CD163, CD206, TMEM119, CSF3R, CX3CR1, TREM2, CD11b, CSF1R, and F4/80) with very strong correlations were identified in the brain using hierarchical clustering analysis. Further correlation analysis demonstrated that the behavioral changes in the OFT were most significantly associated with the expression of inflammation-related genes ( NLRP3, CD163, CD206, F4/80, TMEM119, and TMEM176a), but not glutamate- or GABA-related genes in PLX3397- and MK-801-treated mice. Thus, our results suggest that microglial depletion via a CSF1R/c-Kit kinase inhibitor can ameliorate the hyperactivity induced by an NMDAR antagonist, which is associated with modulation of immune-related genes in the brain.

[Clinical analysis in a cohort of 102 patients with myelodysplastic syndrome characterized by erythroid hyperplasia]

Objective: To investigate the clinical and laboratorial characteristics of patients with myelodysplastic syndrome (MDS) and erythroid hyperplasia. Methods: MDS patients whose bone marrow was hypercellular with erythroid lineage more than 50% and blasts account for less than 20% of non-erythroid cells were enrolled in this study. The ratio of mature erythrocytes to nucleated erythrocytes was no more than 20, namely MDS patients with erythroid hyperplasia(MDS-E). The retrospective analysis comprised 102 patients with MDS-E from the First Affiliated Hospital of Suzhou University. Clinical characteristics, karyotype, and the prognostic significance of erythroid hyperplasia were evaluated. Results: A total of 48 MDS-E patients (47.1%) presented a variety of cytogenetic abnormalities. The most frequently involved chromosomes were chromosome 8 (39.5% of all abnormal karyotypes), chromosome 7 (22.9%), followed by chromosome 5 (18.8%), chromosome 1 (16.7%) and chromosome 20 (16.7%). Hemoglobin (Hb) level affected the prognosis by survival analysis. The overall survival (OS) of MDS-E patients with Hb equal or more than 70 g/L was longer than that of patients less than 70 g/L (P<0.001). Allogeneic hematopoietic stem cell transplantation (HSCT) significantly improved the OS compared with best supportive care (P<0.001) and chemotherapy (P<0.001). The extent of erythroid hyperplasia in bone marrow did not impact on prognosis (P=0.187). Conclusions: Compared with previous reports of MDS patients, MDS-E patients have higher level of erythroid hyperplasia, more common erythroid dyshematopoiesis, more frequent 8 and 1 chromosome abnormalities. The degree of erythroid hyperplasia is not correlated with prognosis. Allogeneic hematopoietic stem cell transplantation improves the prognosis.

[EVI1 expression, clinical and cytogenetical characteristics in 447 patients with acute myeloid leukemia]

Objective: To investigate EVI1 expression and its associated clinical and cytogenetic characteristics in 447 acute myeloid leukemia (AML) patients. Methods: EVI1 expressions were measured in 447 AML cases from Jan. 2007 to Apr. 2015 to couple with clinical, cytogenetic and mutations' characteristics to summarize the features of AMLs with high EVI1 expression. Results: 17.9% of AML were high EVI1 expression (EVI1 +), and the remainder low EVI1 expression (EVI1-). No significant differences between the two groups in terms of age, sex, hemoglobin level, white blood cell count and platelet count were observed. More M0, M5 and M6 subtypes were observed in EVI1+ group (P= 0.027, 0.004 and 0.011, respectively). Cytogenetic abnormalities of 11q15, 11q23/MLL, 3q26, -7/7q- and t (9;11) were observed more frequently in EVI1 + group (P<0.001, <0.001, <0.001, <0.001, =0.014, respectively). Normal karyotype, inv (16), t (8;21) were observed more frequent in EVI1- group (P=0.001, 0.009, 0.002, respectively). EVI1 + was more observed in high risk cytogenetics. Mutation of NPM1 was more observed in EVI1- group (P <0.001). Remission rate in EVI1 + group was significantly lower than EVI1- group (P<0.001). Leukemia-free survival was improved in EVI1 + AML patients undergoing allogeneic hematopoietic stem cell transplantation (allo-HSCT). Conclusions: High EVI1 expression was more observed in FAB subgroup M5, harbored more cytogenetic abnormalities of 11p15, 11q23/MLL, 3q26 rearrangement, -7/7q- and t (9;11). Remission rate of high EVI1 expression AML was lower, which could be improved by allo-HSCT.

Complete mitochondrial genome of the Southern catfish (Silurus meridionalis Chen) and Chinese catfish (S. asotus Linnaeus): Structure, phylogeny, and intraspecific variation

The complete mitochondrial genome of the Southern catfish (Silurus meridionalis) and the Chinese catfish (S. asotus), was determined using the long and accurate polymerase chain reaction (LA-PCR) method. The mitochondrial DNA nucleotide sequences of S. meridionalis and S. asotus were compared with those of 47 other catfish species in the same order. The total length of mitochondrial DNA for S. meridionalis and S. asotus was 16,526 and 16,525 bp, respectively, and included 13 protein-coding genes, 2 ribosomal RNA genes, 22 transfer RNA genes, and a non-coding control region. This mitochondrial gene arrangement is identical to that observed in other Siluriformes. To determine the relative phylogenetic positions of S. meridionalis and S. asotus, and to discover phylogenetic relationships among 24 families of Siluriformes, analyses were conducted, based on mitochondrial DNA, 12S ribosomal RNA, 16S ribosomal RNA, and 13 protein-coding gene sequence data sets. Phylogenetic analyses were congruent with a basal split of the order into Clupeiformes, Characiformes, Cypriniformes, and Siluriformes, and supported a closer relationship of the Southern catfish (family Siluridae) and the Chinese catfish (family Siluridae) to Pimelodidae than to Bagridae. We concluded that these two species are part of a molecular clade that is different from that proposed in recent studies, in which Amblycipitidae appears as a sister group. Our results showed Amblycipitidae appearing as the most basal extant, and Bagridae appearing as a sister group of Cranoglanididae and Pangasiidae. The Siluriformes showed close phylogenetic relationship to the Characiformes.

Immunogene therapy of tumors with vaccine based on Xenopus homologous vascular endothelial growth factor as a model antigen

Overcoming immune tolerance of the growth factors associated with tumor growth should be a useful approach to cancer therapy by active immunity. We used vascular endothelial growth factor (VEGF) as a model antigen to explore the feasibility of the immunogene tumor therapy with a vaccine based on a single xenogeneic homologous gene, targeting the growth factors associated with angiogenesis. To test this concept, we constructed a plasmid DNA encoding Xenopus homologous VEGF (XVEGF-p) and control vectors. We found that immunogene tumor therapy with a vaccine based on XVEGF was effective at both protective and therapeutic antitumor immunity in several tumor models in mice. VEGF-specific autoantibodies in sera of mice immunized with XVEGF-p could be found in Western blotting analysis and ELISA assay. The purified immunoglobulins were effective at the inhibition of VEGF-mediated endothelial cell proliferation in vitro, and at antitumor activity and the inhibition of angiogenesis by adoptive transfer in vivo. The elevation of VEGF in the sera of the tumor-bearing mice could be abrogated with XVEGF-p immunization. The antitumor activity and production of VEGF-specific autoantibodies, significantly elevated IgG1 and IgG2b, could be abrogated by the depletion of CD4(+) T lymphocytes. The observations may provide a vaccine strategy for cancer therapy through the induction of autoimmunity against the growth factors associated with tumor growth in a cross reaction with single xenogeneic homologous gene and may be of importance in the further exploration of the applications of other xenogeneic homologous genes identified in human and other animal genome sequence projects in cancer therapy.

[Effects of murine bone marrow endothelial cell conditioned medium in combination with FL and TPO on the growth of HPP-CFC and CFU-GM]

In the present study, the effects of murine bone marrow endothelial cell conditioned medium (ECM) combined with flt3 ligand (FL) or/and thrombopoietin (TPO) on the proliferation of HPP-CFC and CFU-GM were investigated. Both ECM and the concentrated retentate of ECM (MW>10 kD) promoted the growth of CFU-GM and HPP-CFC, and this promoting effect was further enhanced by addition of FL or TPO. Using reverse transcriptase-polymerase chain reaction (RT-PCR) technique, the expression of FL and TPO mRNA was not found in murine bone marrow endothelial cells.

3,9-Bis(dicyanomethylene)-2,4,8,10-tetrathiaspiro[5.5]undecane

The title compound, 2,2'-(2,4,8,10-tetrathiaspiro[5.5]undecane-3,9-diylidene)bis(propanedinitrile), C(13)H(8)N(4)S(4), has been designed and synthesized for use as a potential new organic molecular electronic material. The spiro-annulated structure has twofold symmetry and is formed by two equal push-pull ethylene units, with the cycloalkylthio groups as electron donors and the cyano groups as electron acceptors. The intermolecular S.N non-bonded separation within a layer in the lattice is 3.296 (6) A, indicating a strong intermolecular interaction between the cyano groups and the S atoms, while the S atoms in two neighbouring molecules have a shortest S.S contact of 3.449 (3) A. In addition, attractive C-H.N and C-H.S interactions bridge adjacent molecules either within a layer or between layers. In short, these four types of intermolecular interactions combine to form an extended three-dimensional network in the lattice, resulting in a highly ordered array of molecular packing.

Cimetidine inhibits production of interferon gamma and tumor necrosis factor alpha by splenocytes in aplastic anemic mice

AIM

To study the effects of cimetidine (Cim) on the production of interferon gamma (IFN gamma) and tumor necrosis factor alpha (TNF alpha) by splenocytes in immune-derived aplastic anemic (AA) mice.

METHODS

Aplastic anemic mice model was constructed first, and then the splenocytes were induced to secrete IFN gamma and TNF alpha. Concentration of IFN gamma was assayed using sandwich ELISA, while that of TNF alpha was measured with L929 cytotoxicity methods.

RESULTS

(1) Concentrations of IFN gamma and TNF alpha secreted by splenocytes from AA mice were (137 +/- 36) ng/L and (6 +/- 3) microg/L, respectively, much more than the irradiated and the control mice. (2) Treatment with Cim 10 micromol/L reduced the concentrations of IFN gamma and TNF alpha to (14 +/- 8) ng/L and (2.7 +/- 0.6) microg/L, respectively.

CONCLUSION

Cim could effectively reduce the production of IFN gamma and TNF alpha from splenocytes of AA mice.

Bone marrow endothelial cells secrete thymosin beta4 and AcSDKP

Bone marrow endothelial cells are the essential component of the bone marrow microenvironment. They produce many kinds of cytokines, including stimulators and inhibitors. Many researchers have suggested that in the presence of endothelial cell layer, CD34+CD38- cells are capable of expansion. The ability of the endothelial cell layer to protect hematopoietic stem cells from extensive differentiation may be related to the inhibitors derived from endothelial cells. The aim of the present study was to determine whether the inhibitors thymosin beta4 and AcSDKP are elaborated by murine bone marrow endothelial cells. Murine bone marrow endothelial cells (mBMECs) were cultured in serum-free conditioned medium. Reverse transcriptase polymerase chain reaction (RT-PCR) was used to analyze the differential expression of the thymosin-beta gene, and reverse phase high-performance chromatography (HPLC) and mass spectroscopy were used to determine the concentration of thymosin beta4 (Tbeta4) and AcSDKP in EC lysate and in the medium (mBMEC-CM). Colony-forming unit granulocyte-macrophage (CFU-GM) colony assays were used to examine the effect of components (mw 3-10 kD, <3 kD) of mBMEC-CM, thymosin beta4, and AcSDKP on the proliferation of hematopoietic cells.mBMECs expressed Tbeta4 mRNA. In EC lysate and mBMEC-CM, Tbeta4 and AcSDKP were detected. After adding protease inhibitors, the concentration of Tbeta4 in EC lysate increased significantly, while the concentration of AcSDKP decreased. mBMEC-CM (mw 3-10 kD) had no effect on the formation of CFU-GM. However, mBMEC-CM (mw <3 kD) could inhibit the growth of CFU-GM. Tbeta4 (10(-11) approximately 10(-7)mol/L) and AcSDKP (10(-11) approximately 10(-5)mol/L) had dose-dependent inhibitory effects on the growth of CFU-GM. Angiotensin converting enzyme (ACE), the enzyme degrading AcSDKP, could partially eliminate the inhibitory effect of mBMEC-CM (mw <3 kD) on CFU-GM.BMECs express and secrete Tbeta4 and AcSDKP. Tbeta4 exists in the 3-10 kD component of mBMEC-CM, while AcSDKP exists in the <3 kD component of ECCM. Both components exert inhibitory effects on the proliferation of hematopoietic progenitors.

[Substitution of BMEC-CM for hematopoietic stimulators in the culture of CFU-GM and HPP-CFC]

The effects of > 10 kD component of serum-free conditioned medium from murine bone marrow-derived endothelial cell line on the formation of CFU-GM and HPP-CFC were investigated. We found that > 10 kD component alone could stimulate CFU-GM colony formation in dose-dependent. Above- 10 kD component supplemented with GM-CSF not only resulted in significant increase of CFU-GM as compared with > 10 kD or GM-CSF alone, but also could stimulate HPP-CFC formation. The effect of > 10 kD component on the formation of HPP-CFC was also in dose-dependent. The component above- 10 kD combined with IL-3, IL-6, EPO, SCF or GM-CSF further enhanced HPP-CFC colony formation. The results suggest that > 10 kD component may be used as the substitutes of hematopoietic growth factors to stimulate the formation of CFU-GM and HPP-CFC.

[The anti-leukemia effect of Sophora flavescens and its mechanism]

By using CFU-GM/CFU-L colony assay, NBT/MTT reductant test and DNA fragmentation analysis, we studied the effects of Sophora flavescens (SF) on CFU-GM proliferative ratio in human normal bone marrow/umbilical cord blood and on proliferation, differentiation and apoptosis in human acute myelogenous leukemia HL-60 cells. The results showed that 5, 10, 15, 20 micrograms.microliter-1 of SF significantly inhibited proliferation and induced apoptosis in the HL-60 cells in a dose-dependent fashion. Fifteen micrograms.microliter-1 of SF also induced differentiation in HL-60 cells. Furthermore, cytotoxic activity of SF(5-15 micrograms.microliter-1) was not apparent on human normal hematopoietic progenitors(CFU-GM). The results indicate that an appropriate concentration of SF has a selective antileukemic effect. Thus, these are important impetuses for further research of SF as an anticancer agent.

Immunotherapy of tumors with xenogeneic endothelial cells as a vaccine

The breaking of immune tolerance against autologous angiogenic endothelial cells should be a useful approach for cancer therapy. Here we show that immunotherapy of tumors using fixed xenogeneic whole endothelial cells as a vaccine was effective in affording protection from tumor growth, inducing regression of established tumors and prolonging survival of tumor-bearing mice. Furthermore, autoreactive immunity targeting to microvessels in solid tumors was induced and was probably responsible for the anti-tumor activity. These observations may provide a new vaccine strategy for cancer therapy through the induction of an autoimmune response against the tumor endothelium in a cross-reaction.

Positive and negative hematopoietic cytokines produced by bone marrow endothelial cells

Recently, cytokines and interleukins such as SCF, GM-CSF, G-CSF, TGF-beta, IL-6, IL-7, IL-8, IL-11 have been reported to be elaborated by endothelial cells. For further study, serum free bone marrow endothelial cell conditioned medium (BMEC-CM) was collected and ultrafiltrated by using a centriprep 10. The concentrated retentate (R-BMEC-CM) contained some substances whose molecular weight was more than 10 000 daltons. The filtrate (F-BMEC-CM) contained some substances whose molecular weight was less than 10 000 daltons. The effects of R-BMEC-CM and F-BMEC-CM on the growth of haematopoietic progenitors and the expression of cytokine and interleukin mRNAs of BMEC were investigated. The results showed that R-BMEC-CM stimulated the growth of CFU-GM, HPP-CFC, BFU-E, CFU-E, and CFU-Meg; while F-BMEC-CM inhibited the growth of these progenitors. Using the method of hybridizing to the Atlas cDNA Array, we were able to detect the presence of mRNAs of cytokines and interleukins in bone marrow endothelial cells. Our finding of the existence of mRNAs of SCF, GM-CSF, IL-6, TGF-beta, IL-1, and IL-11 in these cells was in agreement with the data reported previously. Furthermore, we detected mRNAs of MIP-2, Thymosion-beta4, PDGF, MSP-1, IFN-gamma, IL-13 and inhibin, which are related to haematopoiesis. Among these cytokines and interleukins, SCF, GM-CSF, IL-6, IL-1, and IL-11 are haematopoietic stimulators which may be responsible for the stimulative effects on the growth of haematopoietic progenitors. One of our new findings, the thymosin-beta4, is a small molecular haematopoietic inhibitor. It may be responsible for the inhibitory effect of F-BMEC-CM on haematopoietic progenitors. The presence of mRNAs of BMP, MSP-1, MIP-2, PDGF and IL-13 suggests that bone marrow endothelial cells might elaborate these substances. Their influence on haematopoietic progenitors needs further study.

[Effect of curcumin on the proliferation of murine CFU-GM and WEHI-3B cells]

OBJECTIVE

To evaluate the effect of curcumin on the proliferation of hematopoietic progenitor cells or leukemic stem cells.

METHODS

Mouse bone marrow cells (colony forming unit-granulocyte and macrophage, CFU-GM) and WEHI-3B cells were observed using the colony assays.

RESULTS

The curcumin significantly inhibited the proliferation of both CFU-GM and WEHI-3B cells in a dose-dependent manner ranging from 10(-8) to 10(-4) mol.L-1; their IC50S were 1.036 x 10(-5) mol.L-1 and 1.220 x 10(-6) mol.L-1 of curcumin respectively.

CONCLUSION

The proliferation of murine CFU-GM and WEHI-3B cells can be suppressed by curcumin. The inhibitory effect of curcumin on the proliferation of WEHI-3B cells is stronger than that of CFU-GM.

[Effects of serum-free murine bone marrow endothelial cell conditioned medium on the growth of CFU-E and BFU-E]

Serum-free murine bone marrow endothelial cell conditioned medium(mBMEC-cm) was collected. The mBMEC-cm was ultrafiltered in Centriprep. The concentrated retentive substance of mBMEC-cm (MW > 10,000) and filtrate of mBMEC-cm(MW < 10,000) were obtained. The effects of mBMEC-cm on the growth of CFU-E and BFU-E were investigated. The results showed: 1. The retentive substance of mBMEC-cm significantly enhanced the growth of CFU-E and BFU-E. The effects of mBMEC-cm(2%-6%, V/V) on the growth of CFU-E and BFU-E were dose-dependent. 2. The filtrate of mBMEC-cm markedly inhibited the growth of CFU-E and BFU-E. The effects of the filtrate of mBMEC-cm on the growth of CFU-E and BFU-E were also dose-dependent. The mechanism of regulation will be studied further.

[The effects of cytokines produced by bone marrow endothelial cells on the regulation of hematopoiesis]

In this study, the effects of bone marrow endothelial cell conditioned medium (BMEC-CM) on hematopoietic progenitors and the expression of cytokines mRNA of BMEC were investigated. BMEC-CM was ultrafiltrated in Centriprep-10, an ultrafiltering concentrator. The retentate (MW>10 kD) and filtrate (MW<10 kD) were obtained. The effects of different components of BMEC-CM on the murine hematopoietic progenitors were examined. The results showed that the retentate of BMEC-CM (MW>10 kD) significantly promoted the growth of CFU-GM, CFU-E, BFU-E, CFU-Meg and HPP-CFC, while the growth of CFU-GM, CFU-E, BFU-E, CFU-Meg and HPP-CFC were markedly inhibited by the filtrate of BMEC-CM (MW<10 kD). The effects of BMEC-CM were dose-dependent. The presence of mRNAs for GM-CSF, TGF-beta, bone morphogenetic protein 2A, basic fibroblast growth factor receptor, endothelin-2, macrophage-stimulating 1 (MSP-1), thymosin-beta10, connective tissue growth factor, macrophage inflammatory protein 2 alpha (MIP-2alpha), IL-6, IL-11, IL-13 and IFN-gamma mRNA were successfully detected by Atlas Arrays.

[Effects of bone marrow endothelial cell conditioned medium and its ultrafiltration-prepared components on the growth of CFU-GM]

In this study, we obtained the serum-free conditioned medium from subcultures of murine bone-marrow-derived endothelial cell line which has been established recently by ourselves. And then, molecular weight (MW) > 10 kD, 3-10 kD, 1-3 kD, 0.5-1 kD and < 0.05 kD components were sifted out from the conditioned medium (mBMEC-CM) by means of serial ultrafiltration. Assays of granulocyte-macrophage colony-forming cell (CFU-GM) were performed to examine the effects of mBMEC-CM and its ultrafiltration-prepared components. It was not observed that mBMEC-CM and MW 3-10 kD component had any significant influence on the growth of CFU-GM. However, MW > 10 kD and 0.5-1 kD components enhanced the proliferation of CFU-GM, whereas MW 1-3 kD and < 0.5 kD ones inhibited it. All these four components exerted their effects on the growth of CFU-GM in dose-dependent way. Our observations suggest that under the conditions of in vitro, murine bone marrow endothelial cells produce several active components which have promoting or inhibitory effects on the growth of CFU-GM.

Support versus inhibition of hematopoiesis by two characterized stromal cell types

Stromal cells are believed to regulate hematopoiesis through direct cell-cell contact interactions and the release of growth factors. Many questions remain, however, about their lineage derivation and functional heterogeneity. We have previously shown that the adherent nontransformed, nonimmortalized murine bone marrow stromal cell population consists of three cell types which could be grown separately in vitro. Based on the phenotype characterization and expression of surface antigens, we proposed a classification listing for murine bone marrow stromal cells as macrophages, endothelial-like cells and myofibroblasts that display smooth muscle-like characteristics in culture. The present study describes the ability of each of these freshly isolated separated murine stromal cell populations to support the growth of primitive hematopoietic stem cells previously characterized as highly enriched in long-term repopulating cells (LTRC). Of the three stromal cell types tested only the myofibroblasts were capable of support for multilineage hematopoiesis derived in vitro from LTRC in a cloning ring culture system. Endothelial-like cells had an inhibitory effect on the proliferation of LTRC and their descendant cells that was induced by exogenous growth factors. This inhibitory activity was present in a low molecular weight filtrate of endothelial-like cells culture medium. This suggests an essential role for marrow stroma myofibroblasts in the support of proliferation of hematopoietic cells at the stage of early divisions of primitive hematopoietic stem cells and endothelial-like cells as negative regulators of this proliferation.

Myeloid and erythroid hemopoiesis supported by human bone marrow fibroblasts in vitro

The passages 0 and 3 purified human bone marrow fibroblast layers (FLs) were established by long-term liquid cultures. After 12-day coculture of stromal. cell-depleted marrow cell suspensions with passage 0 FLs, 68.33 +/- 4.04% of the hemopoietic colonies adhered to FLs was myeloid in nature and the other 31.67 +/- 4.04% was erythroid. There were still CFU-E (colony forming unit-erythroid), BFU-E (burst forming unit- erythroid), and CFU-GM (colony forming unit-granulocyte/macrophage) among the nonadherent cells. The media conditioned by passage 0 (F0-CM) and passage 3(F3-CM) FLs stimulated the growth of myeloid and erythroid (BFU-E) colonies. From these data, it is concluded that both FLs and the media conditioned by fibroblasts can stimulate myeloid and erythroid hemopoiesis.

Tb(III) as a fluorescent probe for the structure of bovine serum albumin

Tb(III) was used as a fluorescent probe in the study of the calcium-binding sites on Bovine Serum Albumin (BSA). The fluorescence of Tb(III) is enhanced markedly when bound to BSA and nonradiative energy transfer between two fluorescent tryptophan(Trp) residues and Tb(III) bound to calcium-binding sites on BSA occurred. Experimental results show that the major groups in BSA bound to metal ion are the carboxyl side groups of glutamic acid (Glu) and aspartic acid (Asp). The average distance between the bound Tb(III) and the two tryptophan residues in BSA calculated by a Föster dipole-dipole nonradiative energy transfer mechanism is 1.48 nm.

Dissecting the hematopoietic microenvironment. VIII. Clonal isolation and identification of cell types in murine CFU-F colonies by limiting dilution

In this study it was found that three kinds of cells, fibroblasts, endothelial cells, and macrophages, exist in fibroblastic colony-forming unit (CFU-F) colonies, consistent with the findings of others. However, when low enough bone marrow stromal cell numbers were cultured per dish, pure fibroblast, endothelial, and macrophage colonies were observed. When the cell number cultured in each dish was increased, all colonies were of mixed cell type. This evidence strongly suggests that the macrophages and endothelial cells contained in CFU-F colonies come from locally stimulated growth resulting in contamination and not from a common progenitor with fibroblasts or each other. In some longer term experiments, adipocytes were seen to appear within the colonies of late-passage pure fibroblast cultures.

Dissecting the hematopoietic microenvironment. VII. The production of an autostimulatory factor as well as a CSF by unstimulated murine marrow fibroblasts

Purified normal murine bone marrow-derived fibroblasts were shown to produce a factor that stimulates the in vitro growth of fibroblastic colony-forming unit (CFU-F) colonies. Conditioned medium from the purified fibroblasts (F-CM) also stimulated pure marrow fibroblasts themselves. Analysis of the F-CM detected the presence of macrophage colony-stimulating factor (M-CSF), and low levels of interleukin 1 (IL-1) and interleukin 6 (IL-6), but no detectable levels of interleukin 3 (IL-3), interleukin 5 (IL-5), granulocyte-macrophage colony-stimulating factor (GM-CSF), or granulocyte colony-stimulating factor (G-CSF). Macrophages and endothelial cells, freed from other bone marrow components, required the F-CM if no other growth factors were added. We conclude that F-CM contains an autocrine factor, which the evidence suggests is IL-1, for bone marrow fibroblasts, and a paracrine factor (CSF-1) for macrophages and/or endothelial cells.

Dissecting the hematopoietic microenvironment. VI. The effects of several growth factors on the in vitro growth of murine bone marrow CFU-F

The effects of several growth factors on the proliferation of fibroblastic colony-forming units (CFU-F) were studied. In the present study CFU-F colonies were found to consist of fibroblasts, macrophages, and endothelial cells. Growth factors, including interleukin 3 (IL-3), interleukin 1 alpha (IL-1 alpha), epidermal growth factor (EGF), fibroblast growth factor (FGF), platelet-derived growth factor (PDGF), macrophage colony-stimulating factor (M-CSF), granulocyte-macrophage colony-stimulating factor (GM-CSF), and buffalo rat liver cell-conditioned medium (BRL-CM) were tested for stimulation of the proliferation of CFU-F in a standard culture in both 2% and 15% serum. Overall, the colony numbers produced in 15% serum were much higher than in 2% serum with or without growth factors. However, the influence of several growth factors on CFU-F cultured in 2% serum was relatively greater than in 15% serum when compared to controls. The stimulation of CFU-F by FGF only occurred in culture with 15% serum, and the stimulation by PDGF only occurred with 2% serum. Overall, the strongest stimulations were produced by PDGF, IL-3, and BRL-CM. Combining the other growth factors with IL-3, PDGF, or IL-1 alpha enhanced their effects only modestly. The stimulation by growth factors included increases of the cell numbers between and within colonies as well as an increase in the number of colonies. The study produced results that suggest a complex interaction mediated by growth factors between fibroblasts and other stromal cells within the CFU-F colonies and within the bone marrow itself.

Large tree classifier with heuristic search and global training

In the tree classifier with top-down search, a global decision is made via a series of local decisions. Although this approach gains in classification efficiency, it also gives rise to error accumulation which can be very harmful when the number of classes is very large. To overcome this difficulty, a new tree classifier with the following characteristics is proposed: 1) fuzzy logic search is used to find all ``possible correct classes,'' and some similarity measures are used to determine the ``most probable class''; 2) global training is applied to generate extended terminals in order to enhance the recognition rate; 3) both the training and search algorithms have been given a lot of flexibility, to provide tradeoffs between error and rejection rates, and between the recognition rate and speed. A computer simulation of the decision trees for the recognition of 3200 Chinese character categories yielded a very high recognition rate of 99.93 percent and a very high speed of 861 samples/s, when the program was written in a high level language and run on a large multiuser time-sharing computer.

Analysis and design of a decision tree based on entropy reduction and its application to large character set recognition

Based on a recursive process of reducing the entropy, the general decision tree classifier with overlap has been analyzed. Several theorems have been proposed and proved. When the number of pattern classes is very large, the theorems can reveal both the advantages of a tree classifier and the main difficulties in its implementation. Suppose H is Shannon's entropy measure of the given problem. The theoretical results indicate that the tree searching time can be minimized to the order O(H), but the error rate is also in the same order O(H) due to error accumulation. However, the memory requirement is in the order 0(H exp(H)) which poses serious problems in the implementation of a tree classifier for a large number of classes. To solve these problems, several theorems related to the bounds on the search time, error rate, memory requirement and overlap factor in the design of a decision tree have been proposed and some principles have been established to analyze the behaviors of the decision tree. When applied to classify sets of 64, 450, and 3200 Chinese characters, respectively, the experimental results support the theoretical predictions. For 3200 classes, a very high recognition rate of 99.88 percent was achieved at a high speed of 873 samples/s when the experiment was conducted on a Cyber 172 computer using a high-level language.

Application of a multilayer decision tree in computer recognition of chinese characters

A multistage classifier with general tree structure has been developed to recognize a large number of Chinese characters. A simple and efficient method of classifying the characters was achieved by choosing the best feature at each stage of the tree. The features used are Walsh coefficients obtained from two profiles of a character projected onto the X-Y orthogonal axes. Some algorithms for aligning the characters were compared and one of them was adopted in this recognition scheme. A high recognition rate of about 99.5 percent was obtained in an experiment with more than 3000 different Chinese characters.