Selective release of a processed form of interleukin 1α

Interleukin 1α (IL-1α) is synthesized as a 33 kDa form and proteolytically processed into a 17 kDa form. Although IL-1α has no signal peptide, it is released from cells. To investigate the relationship between the processing and release of IL-1α, human bladder carcinoma cells (HTB9 5637) which express IL-1α constitutively, were treated with calcium ionophore (A23187). A23187 induced the processing of 33 kDa IL-1α and selectively released processed 17 kDa IL-1α, without any change in the release of 33 kDa IL-1α. When extracellular calcium was chelated by EGTA, or when intracellular calpain was inhibited by the cell-permeable cysteine-protease inhibitor, E64d, the processing of 33 kDa IL-1α was significantly blocked, the release of 33 kDa IL-1α being unchanged. These results indicate that the release of IL-1α was accompanied by the processing of 33 kDa IL-1α.     

Antibacterial properties of nine pure metals: a laboratory study using Staphylococcus aureus and Escherichia coli

Bacterial attachment and growth on material surfaces are considered to be the primary steps leading to the formation of biofilm. Biofilms in hospital and food processing settings can result in bacterial infection and food contamination, respectively. Prevention of bacterial attachment, therefore, is considered to be the best strategy for abating these menaces and therefore the development of antibacterial metals becomes important. In this study, nine pure metals, viz. titanium, cobalt, nickel, copper, zinc, zirconium, molybdenum, tin, and lead have been tested for their antibacterial properties against two bacterial strains, Gram-positive Staphylococcus aureus and Gram-negative Escherichia coli. This was accomplished using two assay methods, the film contact method and the shaking flask method. The results show that the antibacterial properties varied significantly with different metals and the effectiveness of metals to resist bacterial attachment varied with the bacterial strain. Among the metals tested, titanium and tin did not exhibit antibacterial properties. TEM images showed that metal accumulation resulted in the disruption of the bacterial cell wall and other cellular components.     

The NIK protein kinase and C17orf1 genes: chromosomal mapping, gene structures and mutational screening in frontotemporal dementia and parkinsonism linked to chromosome 17

Full exon-intron structures are presented for the NIK serine/threonine protein kinase gene and a novel gene termed C17orf1. By in situ hybridisation and radiation hybrid mapping, a cosmid (cDD-Z) that contains regions of both of these genes has been localised between markers D17S800 and D17S791 at chromosome 17q21. The two genes are thus positional candidates for the mutant locus underlying frontotemporal dementia and parkinsonism linked to chromosome 17 (FTDP-17), a disease for which NIK is also a good biological candidate. Using exon-intron maps, a genomic DNA sequencing based mutation screen has been performed for the NIK and C17orf1 genes in a chromosome 17-linked FTDP-17 pedigree. Two silent single-base variations were detected in C17orf1. No alterations were restricted to DNA samples from patients, thus excluding the C17orf1 and NIK genes as likely sites of mutation FTDP-17. Received: 23 December 1997 / Accepted: 23 June 1998