F C de Beer

Acute Phase Response in Bronchiectasis and Bronchus Carcinoma

Measurement of the acute phase response in patients suffering from bronchiectasis, emphysema, bronchus carcinoma and various benign space occupying lesions was undertaken, using sensitive immunoradiometric assays for C-reactive protein and serum amyloid-A protein. In some patients with bronchiectasis, clinically judged to be in remission, the results show a major ongoing acute phase response. Such a response could predispose these patients to the development of reactive secondary amyloidosis. In bronchus carcinoma, the application of these measurements to judge the extent of tumour growth is limited as infection complicating obstruction is a more potent initiator of the acute phase response than the neoplastic process per se.

Serum Amyloid A Protein in Plasma: Characteristics of Acute Phase HDL

The changes in plasma protein levels that constitute the acute phase response are the result of selectively altered hepatic protein synthesis. Macrophage-derived interleukin-1 (IL-1) affects gene expression, possibly through a dual signal system, decreasing mRNA for negative acute phase reactants like albumin and increasing mRNA for positive acute phase reactants (1). In the mouse, mRNA for serum amyloid A increases up to 500 fold to constitute up to 2.5% of total hepatic protein synthesis (2).

Cerebrospinal fluid alpha-1-antitrypsin alpha-1-antitrypsin-elastase complex levels in meningitis

Abstract. Alpha‐1‐antitrypsin (A‐1‐AT) and A‐1‐AT‐elastase complex levels in cerebrospinal fluid have been evaluated in 11 children with viral meningitis (VM), 14 with bacterial meningitis (BM), 10 with tuberculous meningitis (TBM) and 10 investigated for, but found not to have meningitis (NM). A‐1‐AT concentrations in the NM group were lower than in the BM group (P=0.0002) and the TBM group (P=0.0005) but did not differ from the concentrations in VM; those in the VM group were lower than in the BM group (P=0.0001) and the TBM group (P=0.003) but no difference was found between the BM and TBM groups. A‐1‐AT‐elastase complex concentrations in CSF were lower in the NM group than the BM group (P=0.0001) or the TBM group (P=0.0089), however those in the BM group were significantly higher than in the TBM group (P=0.0001). A significant correlation existed in CSF between the protein concentrations and neutrophil counts as well as the A‐1‐AT and A‐1‐AT‐elastase complex concentrations.

4.P.317 Alternative forms of the scavenger receptor BI (SR-BI)

The class B, type I scavenger receptor has been implicated as a receptor for high density lipoprotein (HDL). We have isolated a murine cDNA clone encoding an alternative form of SR-BI that differs in the putative cytoplasmic domain of the receptor. This variant form, likely the result of alternative mRNA splicing, is designated SR-BI.2. SR-BI.2 mRNA was detected in mouse tissues known to express SR-BI and tissue-specific differences in the relative abundance of SR-BI.2 were apparent. In mouse adrenal glands, SR-BI.2 represented approximately one-third of total SR-BI mRNA, whereas in mouse testes, SR-BI.2 represented the major mRNA species (79% of total). SR-BI.2 was also detected in the human cell lines examined, namely HeLa, HepG2, and THP-1 cells. CHO cells transfected with the mouse SR-BI.2 cDNA expressed significant levels of SR-BI.2 protein and acquired the ability to take up fluorescent lipid (DiI) from DiI-HDL. Alternative splicing of SR-BI represents a potentially important process for the regulation of SR-BI expression and function.