Changes in beta-2 adrenergic receptor sensitivity with maturation of erythroid progenitor cells

Summary Erythroid burst forming units (BFU-E) were much more sensitive to the beta-2 selective adrenergic drug, salbutamol, than erythroid colony forming units (CFU-E) in an in vitro study of erythroid progenitor cells.This work was supported by USPHS Grant AM13211. B. Beckman is a USPHS Postdoctoral Fellow AM05960.     

Radioprotective and haemopoietic effects of some lipopolysaccharides from Rhodospirillaceae species in mice

Summary Lipopolysaccharides (LPS) from variousRhodopseudomonas andRhodospirillum species were tested for their radioprotective efficiency against X-irradiation and for their influence on the growth of spleen colony forming units (CFU-s) in mice. The LPS fromRhodopseudomonas gelatinosa Dr₂ gave a high survival rate. It also favoured CFU-s formation and erythroid differentiation.     

Molecular evidence for increased hematopoietic proliferation in the spleen of the b/b laboratory rat

The splenomegaly and the appearance of a significant number of CFU-E (erythroid colony-forming units) and BFU-E¹ (erythroid burst-forming units) in the Belgrade laboratory rat (b/b) spleen prompted us to analyse further the molecular evidence for increased hematopoietic proliferation in the b/b spleen. Messenger RNAs (mRNAs) specific for globins, proteins for iron transport and deposition and the band 3 protein were used in rat erythropoietic tissues as markers for proliferation and erythroid differentiation. In the b/b spleen, all mRNAs analysed display an erythroid-specific pattern of expression. This analysis also revealed an enhanced level of mRNA for ferritin in the +/b spleen, whereas erythrocyte-specific mRNA production was normal.     

Somatostatin reduces the release of colony-stimulating activity (CSA) from PHA-activated mouse spleen lymphocytes.

PHA-activated lymphocytes release colony-stimulating activity (CSA) for macrophage-granulocyte precursor cells (colony forming units, CFUc) in the culture medium. Somatostatin, known to interfer with ribosomal protein synthesis, was demonstrated to reduce the release of CSA from PHA-treated mouse spleen lymphocytes.     

Somatostatin reduces the release of colony-stimulating activity (CSA) from PHA-activated mouse spleen lymphocytes

Summary PHA-activated lymphocytes release colony-stimulating activity (CSA) for macrophage-granulocyte precursor cells (colony forming units, CFU_C) in the culture medium. Somatostatin, known to interfer with ribosomal protein synthesis, was demonstrated to reduce the release of CSA from PHA-treated mouse spleen lymphocytes.The technical assistance of Ulrike Wallner and Paulette Bais is thankfully acknowledged.     

Characterization of murine non-adherent bone marrow cells leading to recovery of endogenous hematopoiesis

Non-adherent bone marrow-derived cells (NA-BMCs) are a mixed cell population that can give rise to multiple mesenchymal phenotypes and that facilitates hematopoietic recovery. We characterized NA-BMCs by flow cytometry, fibroblast colony-forming units (CFU-f), real-time PCR, and in in vivo experiments. In comparison to adherent cells, NA-BMCs expressed high levels of CD11b⁺ and CD90⁺ within the CD45⁺ cell fraction. CFU-f were significantly declining over the cultivation period, but NA-BMCs were still able to form CFU-f after 5 days. Gene expression analysis of allogeneic NA-BMCs compared to bone marrow (BM) indicates that NA-BMCs contain stromal, mesenchymal, endothelial cells and monocytes, but less osteoid, lymphoid, and erythroid cells, and hematopoietic stem cells. Histopathological data and analysis of weight showed an excellent recovery and organ repair of lethally irradiated mice after NA-BMC transplantation with a normal composition of the BM.     

Effect of sodium ribonucleate on the growth and the hemolytic activity of Treponema hyodysenteriae]

Liquid cultures of different strains of Treponema hyodysenteriae, when supplemented with sodium ribonucleate show an increase in the hemolytic activity titers while the number of colony forming units remain constant.     

Effect of aminoglutethimide on murine fetal hepatic erythroid colony formation

Pretreatment of pregnant mice with aminoglutethimide phosphate, an inhibitor of glucocorticoid synthesis, increases the content of fetal liver erythroid colony-forming cells (CFU-E), as assessed by the formation of erythroid colonies in vitro by fetal liver cells in plasma clots containing exogenous erythropoietin. In addition, the inability of aminoglutethimide to influence erythroid colony formation in vitro suggests that endogenous glucocorticoids exert a suppressive effect on the number of functional CFU-E in the fetal liver.     

Effet du ribonucléate de sodium sur la croissance et l'activité hémolytique deTreponema hyodysenteriae

Summary Liquid cultures of different strains ofTreponema hyodysenteriae, when supplemented with sodium ribonucleate show an increase in the hemolytic activity titers while the number of colony forming units remain constant.     

Colony promoting activity and its target 'pre-CFUc' in genetically anemic mice of W/Wv genotype

Incubation of bone marrow cells with supernatant from long-term cultures of bone marrow cells increases the number of granulocyte-macrophage progenitor cells. This study reveals the presence of target cells of the colony promoting activity (CPA) in W/Wv mouse marrow. It is also shown that CPA does not stimulate erythroid colony formation in vitro.     

The influence of cold or isolation stress on resistance of mice to West Nile virus encephalitis

The effect of cold or isolation stress on mortality rate and brain virus level were investigated in mice infected with West Nile virus (WNV). Exposure of mice for 5 min/day to cold water (1 +/- 0.5 degrees C) for 8-10 days resulted in 92% mortality as compared to 47% in control mice (p less than 0.001). Mice housed in individual cages (isolation stress) were also more susceptible to WN viral infection, as shown by increased mortality rate reaching 85% as compared to 50% in mice housed 6 per cage (p less than 0.01). Cold or isolation stress increased blood brain and spleen virus levels as early as 2 days after inoculation. After 8 days of isolation or cold stress, mice inoculated with WNV had 8.9 and 9.0 log10 plaque forming units in the brain, respectively, as compared to 6.9 in the control (p less than 0.01-0.001). Furthermore, lymphoid organs such as spleen and thymus showed severe mass loss. These data suggest that physical or non-physical stress situations enhance WNV encephalitis by accelerating virus proliferation and increase mortality in mice.     

Comparison of the biological effects of anemia inducing and polycythemia inducing Friend virus complex.

The comparison of the biological effects of FVP and FVA showed that leukemogenesis appears to be delayed in FVA infected mice as compared to FVP infected animals after injection of comparable quantities of virus as measured in spleen focus forming units. In addition, no CFU-EI, characteristic for FVP induced leukemia, were found in leukemic spleen or bone marrow of FVA infected mice. Since it was possible to distinguish both viruses by their different host ranges, which are helper virus determined, it is suggested that the observed differences, especially the lack of CFU-EI in FVA infected mice, might be due to differences in the helper virus component of the FV complex.     

The influence of cold or isolation stress on resistance of mice to West Nile virus encephalitis

Summary The effect of cold or isolation stress on mortality rate and brain virus level were investigated in mice infected with West Nile virus (WNV). Exposure of mice for 5 min/day to cold water (1±0.5°C) for 8–10 days resulted in 92% mortality as compared to 47% in control mice (p<0.001). Mice housed in individual cages (isolation stress) were also more susceptible to WN viral infection, as shown by increased mortality rate reaching 85% as compared to 50% in mice housed 6 per cage (p<0.01). Cold or isolation stress increased blood brain and spleen virus levels as early as 2 days after inoculation. After 8 days of isolation or cold stress, mice inoculated with WNV had 8.9 and 9.0 log₁₀ plaque forming units in the brain, respectively, as compared to 6.9 in the control (p<0.01–0.001). Furthermore, lymphoid organs such as spleen and thymus showed severe mass loss. These data suggest that physical or non-physical stress situations enhance WNV encephalitis by accelerating virus proliferation and increase mortality in mice.     

Cathepsin A/protective protein: an unusual lysosomal multifunctional protein

Cathepsin A/protective protein [3.4.16.5], carboxypeptidase A, is a lysosomal serine protease with structural homology to yeast (Saccharomyces cerevisiae) carboxypeptidase Y. Cathepsin A is a member of the alpha/beta hydrolase fold family and has been suggested to share a common ancestral relationship with other alpha/beta hydrolase fold enzymes, such as cholinesterases. Several lines of evidence indicate that cathepsin A is a multicatalytic enzyme with deamidase and esterase in addition to carboxypeptidase activities. Cathepsin A was recently identified in human platelets as deamidase. In vitro, it hydrolyzes a variety of bioactive peptide hormones including tachykinins, suggesting that extralysosomal cathepsin A plays a role in regulation of bioactive peptide functions. Recent reports emphasize the lysosomal protective function of cathepsin A rather than its protease function. The protective function of cathepsin A is distinct from its catalytic function. Human lysosomal beta-galactosidase and neuraminidase exist as a high molecular weight enzyme complex, in which there is a 54-kDa glycoprotein termed 'lysosomal protective protein'. Based on cell culture studies, protective protein was found to protect both beta-galactosidase and neuraminidase from intralysosomal proteolysis by forming a multienzyme complex and was shown to be deficient in patients with galactosialidosis, a combined deficiency of beta-galactosidase and neuraminidase. Molecular cloning and gene expression studies have disclosed that protective protein is cathepsin A. The cathepsin A precursor has the potential to restore both beta-galactosidase and neuraminidase activities in fibroblasts from patients with galactosialidosis. Cathepsin A knockout mice showed a phenotype similar to human galactosialidosis and the deficient phenotype found in the mutant mice was corrected by transplanting erythroid precursor cells overexpressing cathepsin A. Collectively, these findings demonstrate the significance of cathepsin A as a key molecule in the onset of galactosialidosis and also highlight the therapeutic potential of the cathepsin A precursor for patients with galactosialidosis.     

金属半固态成型发展现状及展望

金属半固态成形技术具有短流程、近净形生产的特点,并且成形产品的组织性能优良、工模具寿命明显延长,因此受到了世界各国的广泛重视.本文综述了国内外半固态成形的应用及其计算机数值模拟技术和模拟方法的研究现状,并对金属半固态成形技术今后的发展研究方向进行了展望.     

Comparison of the biological effects of anemia inducing and polycythemia inducing Friend virus complex

Summary The comparison of the biological effects of FV^P and FV^A showed that leukemogenesis appears to be delayed in FV^A infected mice as compared to FV^P infected animals after injection of comparable quantities of virus as measured in spleen focus forming units. In addition, no CFU-EI, characteristic for FV^P induced leukemia, were found in leukemic spleen or bone marrow of FV^A infected mice. Since it was possible to distinguish both viruses by their different host ranges, which are helper virus determined, it is suggested that the observed differences, especially the lack of CFU-EI in FV^A infected mice, might be due to differences in the helper virus component of the FV complex.Supported by the Deutsche Forschungsgemeinschaft (SFB 112 Zellsystemphysiologie).     

In situ hybridization analysis of globin mRNAs in the primitive erythroid cells of the chick embryo

The possibility that the minor embryonic chick hemoglobins might be present in a particular subgroup of primitive erythroid cells has been investigated by in situ hybridization. Probe to detect the mRNA for the ^A globin chain of the minor embryonic hemoglobin was used, and the results of the hybridization were compared with those obtained using as probes the cDNAs for total globin mRNAs. All erythroid cells circulating in a 4-day-old chick embryo gave positive signals with both probes at an approximately constant ratio. This shows that all cells contain a similar assortment of hemoglobin types, excluding the possibility that a subgroup might contain the minor primitive hemoglobins exclusively. However, the cells are not homogeneous, since about 10% of them show a distinctly higher concentration of mRNA of all globin types.     

Preferential differentiation of hematopoietic stem cells transferred to mice previously infected by BCG]

Following injection of bone marrow cells in lethally irradiated mice, previously infected with BCG regenerating hemopoietic cell populations differentiate along the leucocyte pathway to the detriment of erythroid lineage. Such a phenomenon persisting even if anemia of infected mice is increased by bleeding just before irradiation and reconstitution supports the hypothesis of preferential differentiation of stem cells.     

Age-related differences in the effect of in vivo administration of indomethacin on hemopoietic cell lineages of the spleen and bone marrow of mice

During 21 days of indomethacin treatment, erythroid cells in the spleens of both young adult and older mice, and in the bone marrow of young adult mice, were increased significantly early, in treatment, relative to age-matched control organs, and remained high throughout treatment. During drug exposure, the numbers of myeloid cells in young adult bone marrow, but not spleen, were reduced, but in older mice these cells were elevated in both organs. Lymphoid cells in the young adult and older mouse spleens decreased and increased, respectively, during treatment, but were unchanged and decreased, respectively, in the bone marrow of young adult and older mice. Monocytemacrophage cells in the spleen were elevated but unchanged in the bone marrow of both age groups. During 14 days of indomethacin treatment of houng adult mice, the proportions of precursor cells in DNA synthesis of only the splenic erythroid lineage were increased. Thus, the major hemopoietic lineages in both the bone marrow and spleen are affected by exposure to indomethacin in a time-dependent and age-dependent manner. For all lineages studied, those of the bone marrow were least disturbed, and/or were first to recover, even during continued drug exposure.