The effects of the treatment of multiple myeloma (MM) with APD‐bisphosphonate on bone destruction, the dissemination pattern of the MM, and toxicity for normal and malignant cells were investigated ...in an animal model, the 5T2 MM. This mouse MM very closely resembles the human disease, including the typical bone lesions. It was demonstrated by radiography, microradiography, and histologic investigation that the treatment of the 5T2 MM with APD‐bisphosphonate protected the mice against a loss of bone to a significant extent. It seemed that the treatment with APD not only diminished the bone destruction by the MM but also led to the formation of new bone in already‐affected bone tissue. The growth pattern of the MM was not substantially influenced by the treatment, even though there was an indication that APD exerts some cytotoxic effect on the MM cells.
HL-60 cells are induced to differentiate along a monocytic pathway by the active metabolites of vitamin D3, e.g. 1,25-dihydroxyvitamin D3 1,25-(OH)2D3. All such differentiated cells share a number of ...features in common but are heterogeneous in their ability to adhere to solid substrates and to resorb devitalized bone matrix. Here, we show that, in addition, as compared to the nonadherent, adherent cells are smaller, less likely to be in the S phase, more enriched in the human monocyte-specific cell surface antigen, 63D3, and contain less cmyc messenger RNA (mRNA). In addition, we document that removal of the hormone leads to dedifferentiation. For these susceptible mononuclear cells, removal of 1,25-(OH)2D3 results in a reversion to a more myeloblastic phenotype, renewed cell proliferation, and the rapid appearance of elevated levels of cmyc mRNA. Finally, we report that the cells that do not revert upon 1,25-(OH)2D3 removal are those that became multinucleated during treatment.
The transcription start sites of the human gene coding for the coagulation factor IX have been identified. Three major transcription initiation sites within a small area of ~ 30 nucleotides were ...found by Sl nuclease analysis and primer extension studies.
Summary
Probands from 15 unrelated families with hereditary protein S deficiency type I, that is having a plasma total protein S concentration fifty percent of normal, were screened for abnormalities ...in their protein S genes by Southern analysis. Two probands were found to have a deviating DNA pattern with the restriction enzyme Mspl. In the two patients the alteration concerned the disappearance of a Mspl restriction site, CCGG, giving rise to an additional hybridizing Mspl fragment.
Analysis of relatives of both probands showed that in one family the mutation does not co-segregate with the phenotype of reduced plasma protein S. In the family of the other proband, however, complete linkage between the mutated gene pattern and the reduced total protein S concentration was found: 12 heterozygous relatives showed the additional Mspl fragment but none of the investigated 26 normal members of the family. The mutation is shown to reside in the PSβ gene, the inactive protein S gene. The cause of type I protein S deficiency, a defect PSα gene has escaped detection by Southern analysis. No recombination has occurred between the PSα gene and the PSβ gene in 23 informative meioses. This suggests that the two protein S genes, located near the centromere of chromosome 3, are within 4 centiMorgan of each other.
In the pathogenesis of sepsis and disseminated intravascular coagulation (DIC), dysfunctional anticoagulant pathways are important. The function of the protein C system in DIC is impaired because of ...low levels of protein C and down-regulation of thrombomodulin. The administration of (activated) protein C results in an improved outcome in experimental and clinical studies of DIC. It is unknown whether congenital deficiencies in the protein C system are associated with more severe DIC. The aim of the present study was to investigate the effect of a heterozygous deficiency of protein C on experimental DIC in mice. Mice with single-allele targeted disruption of the protein C gene (PC+/–) mice and wild-type littermates (PC+/+) were injected with Escherichia coli endotoxin (50 mg/kg) intraperitoneally. PC+/–mice had more severe DIC, as evidenced by a greater decrease in fibrinogen level and a larger drop in platelet count. Histologic examination showed more fibrin deposition in lungs, kidneys, and liver in mice with a heterozygous deficiency of protein C. Interestingly, PC+/– mice had significantly higher levels of proinflammatory cytokines, tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), and IL-1β, indicating an interaction between the protein C system and the inflammatory response. Survival was lower at 12 and 24 hours after endotoxin in the PC+/– mice. These results confirm the important role of the protein C system in the coagulative-inflammatory response on endotoxemia and may suggest that congenital deficiencies in the protein C system are associated with more severe DIC and adverse outcome in sepsis.
The protein S locus, situated on chromosome 3, consists of two protein S genes. Here, we report the cloning and complete nucleotide sequence of the 3'-untranslated region of the two genes designated ...PS alpha and PS beta. Both regions span approximately 1,200 nucleotides. They show a high degree (-97%) of homology, with deviations caused by small deletions, insertions and point mutations. Comparison of PS alpha and PS beta with the reported protein S liver cDNAs, shows that the latter all originate from the PS alpha gene. The PS alpha gene therefore is marked as the major site of synthesis of liver protein S mRNA. Sequence comparison with the bovine protein S cDNA reveals that the PS beta gene has accumulated a few more mutations than the PS alpha gene since duplication of the ancestral protein S gene that seems to have occurred recently during primate evolution.
Dose-related effects of APD on bone metabolism and Ca homeostasis were studied in rats. The experimental approach consisted of longitudinal and cross-sectional observations, aiming at a kinetic ...interpretation. Bone and cartilage resorption was inhibited with 2--8 days at doses between 0.16 and 16 mumol/kg body weight/day. This was followed by changes in bone apposition that needed at least 23 days for a maximal effect. The time lag created a transient dissociation between resorption and apposition resulting in excess Ca and P retention, adding to increased metaphyseal bone mass. At high doses of APD (greater than or equal to 40 mumol/kg/day)the mineral content of new matrix decreased, associated with impairment of longitudinal growth of long bones. It is concluded that the lower doses of APD inhibited resorption of bone and cartilage, possibly by physicochemical stabilization of bone mineral, whereas the effect on bone apposition was due to a cellular homeostatic mechanism. Inhibition of growth and of matrix calcification, requiring much higher doses, may be due to a direct, toxic effect on bone cells. The modes of action of APD are discussed in relation to EHDP and Cl2MDP.
Partial cDNAs coding for human protein S were isolated from a pUC9 human liver cDNA library. Together, the overlapping clones span a (partial) 5′-non-coding region, and the complete protein S coding ...and 3′-untranslated regions. The derived amino acid sequence deviates at five positions from two previously reported protein S sequences. Two of these differences (Phe instead of Leu at position — 16 and Tyr instead of Asp at position 222) are found in regions that are important for the post-translational modification of protein S, the γ-carboxylation of glutamic acid and the hydroxylation of asparagine, respectively.
A Pstl RFLP of the LACl gene van der Logt, C.Paul E.; Reitsma, Pieter H.; Bertina, Rogier M.
Nucleic acids research,
10/1990, Letnik:
18, Številka:
19
Journal Article
PDF
