Human bone marrow stromal cells (hMSCs) were stably transduced by a retroviral vector containing the gene for the catalytic subunit of human telomerase (hTERT). Transduced cells (hMSC-TERTs) had telomerase activity, and the mean telomere length was increased as compared with that of control cells. The transduced cells have now undergone more than 260 population doublings (PD) and continue to proliferate, whereas control cells underwent senescence-associated proliferation arrest after 26 PD. The cells maintained production of osteoblastic markers and differentiation potential during continuous subculturing, did not form tumors, and had a normal karyotype. When implanted subcutaneously in immunodeficient mice, the transduced cells formed more bone than did normal cells. These results suggest that ectopic expression of telomerase in hMSCs prevents senescence-associated impairment of osteoblast functions.

Translation termination in eukaryotes is governed by termination codons in mRNA and two release factors, eRF1 and eRF3. In this work, human eRF1 and eRF3 have been produced in insect cells using a recombinant baculovirus expression system for the corresponding human cDNAs. Purification of eRF1 has led to a homogeneous 50-kDa protein active in promoting ribosome-dependent and termination-codon-dependent hydrolysis of formylmethionyl-tRNAf(Met). Purification of eRF3 yielded a full-length protein and shorter polypeptides. Microsequencing of the N-terminus of the shortest form detected a site of proteolytic cleavage between Arg91 and Gly92, probably due to exposed region(s) hypersensitive to proteolysis. The mixture of full-length and truncated forms of eRF3 as well as bacterially expressed eRF3 lacking 138 N-terminal amino acids (eRF3Cp) are active as an eRF1-dependent and ribosome-dependent GTPase and in stimulating the GTP-dependent release activity of eRF1. Complex formation between eRF1 and eRF3Cp was demonstrated by affinity and gel-filtration chromatographies and by native-gel electrophoresis. An abnormal electrophoretic mobility observed for eRF1 as compared with the complex points to a significant conformational change of either eRF1 or both factors in the complex. Co-expression of both factors in baculovirus-infected insect cells and a yeast two-hybrid assay were applied to monitor complex formation in vivo. In yeast cells, both eRF1 and eRF3 are either in a monomeric or in a heterodimeric but not in a homodimeric state.

Aim: To review evidence for the treatments of gingival recession and root caries in older populations. Materials & Methods: A systematic approach was adopted to identify reviews and articles to allow us to evaluate the treatments for gingival recession and root caries. Searches were performed in PubMed, Medline and Embase, the Cochrane trials register and bibliographies of European and World Workshops. Observations: Gingival recession: We identified no articles that focussed specifically on older populations. Conversely, no evidence suggested that Miller class I and II lesions should be managed differently in older patients when compared to younger cohorts. Six systematic reviews included older patients and suggested that connective tissue grafts are the treatment of choice, alone or in combination with enamel matrix derivative. Root caries can be controlled at the population level by daily brushing with fluoride-containing toothpastes, whilst active decay may be inactivated using professional application of fluoride varnishes/solutions or selfapplied high-fluoride toothpaste. Active root caries lesions that cannot be cleaned properly by the patient may be restored by minimally invasive techniques. Conclusions: Gingival recession and root caries will become more prevalent as patients retain their teeth for longer. Whilst surgical (gingival recession) and nonoperative approaches (root caries) currently appear to be favoured, more evidence is needed to identify the most appropriate strategies for older people.

Interferons exert their biological function mainly through the activation of interferon-stimulated genes (ISGs). ISG12 (originally designated p27) belongs to a family of small, interferon a inducible genes of unknown function. We have determined the 5 0 end sequence of ISG12 cDNA from the human cell lines HeLa and AMA by RACE. Comparing this sequence to ISG12 sequences in the expressed sequence tag (EST) database revealed the presence of two alternative splice variants of ISG12 in human cells exhibiting the same open reading frame. We have sequenced the promoter region of the ISG12 gene and found ISRE, IRF1/IRF2, and STAT elements correlating to the interferon a inducibility of the gene. Subsequently, we have expressed human ISG12, a 12-kDa hydrophobic protein in the baculovirus expression system and with a C-terminal FLAG-tag in the human cell line 293. Recombinant ISG12 sediments in the nuclear envelope in both cell types. Finally, we have been able to demonstrate the prevalence of the ISG12 gene product in the nuclear envelope of HeLa cells treated with interferon a by immunocytochemical analyses. ISG12 is the first interferon induced protein found localizing to the nuclear envelope.Keywords: interferon; nuclear envelope; ISG12; baculovirus; FLAG.Interferons (IFNs) are a family of cytokines in vertebrates with a variety of biological functions, such as growth inhibition, antitumoral, immunomodulatory, antiviral, and antiparasitic actions. Human IFNs are grouped into type I and type II, and the biological actions of IFNs are mainly mediated through the gene products of more than 100 IFN stimulated genes (ISGs) (reviewed in [1,2]). The best characterized ISGs are PKR, the 2 0 -5 0 oligoadenylate synthetases (2-5OAS), and RNAse L (reviewed in [3 -5]). A group of small ISGs consisting of ISG12, 6-16, 9-27, 1-8, ISG15 and 6-26 still remains relatively uncharacterized and their functions are still basically unknown [6][7][8][9][10]. The 6-16 promoter has been well characterized and utilized in many studies [11,12], most prominently in the discovery of the JAK-STAT pathways [1,13].The cDNA of ISG12 (encoding a putative ISG protein of M r 12 000) was originally cloned as an oestrogen-induced gene in the human breast epithelial cell line, MCF7 and designated p27 [10]. Even though it was demonstrated that the level of expression of ISG12 mRNA is induced by oestrogen in MCF7 cells, and high expression levels of ISG12 mRNA are found in many breast carcinomas, ISG12 expression does not correlate with the presence of the oestrogen receptor neither in the cell lines tested nor in breast carcinomas [10]. Analysis of a number of breast tissue sections for expression of ISG12 mRNA by in situ hybridization revealed that: (a) no ISG12 transcripts were found in normal cells of the sections; (b) a high level of expression was found in cancer cells in most of the sections; and (c) a low level of expression was found in fibroblasts of some fibroadenomas [10]. In addition, we have previously demonstrated by quantitative RT-PCR that I...