The pandemic of Salmonella enteritidis phage type 4 reaches Utah: a complex investigation confirms the need for continuing rigorous control measures.

In 1995, Salmonella Enteritidis (SE) cases in the state of Utah increased fivefold. Isolates were identified as phage type 4 (PT4). Risk factors and sources of infection were investigated in two case-control studies, a traceback of implicated foods, and environmental testing. Forty-three patients with sporadic infections and 86 controls were included in a case-control study of risk factors for infection. A follow-up case-control study of 25 case and 19 control restaurants patronized by case and control patients examined risks associated with restaurant practices. In the first case-control study, restaurant dining was associated with illness (P = 0.002). In the follow-up case-control study, case restaurants were likelier to use > 2000 eggs per week (P < 0.02), to pool eggs (P < 0.05), and to use eggs from cooperative 'A' (P < 0.009). Eggs implicated in separately investigated SE PT4 outbreaks were traced to cooperative 'A', and SE PT4 was cultured from one of the cooperative's five local farms. We conclude that SE PT4 transmitted by infected eggs from a single farm caused a fivefold increase in human infections in Utah.

Working memory and the syndromes of schizotypal personality.

The aim of this study was to investigate dorsolateral prefrontal function, as assessed by a spatial working memory task, in relation to the syndromal features of schizotypal personality. We found a weak association between a self-report measure of schizotypy and the working memory performance. Those with a high score on the schizotypal personality questionnaire tended to make more errors on the spatial working memory task. One sub-scale of the schizotypal personality questionnaire that taps into social functioning was significantly correlated with working memory deficit. This result suggests the presence of subtle prefrontal deficit in a sub-group of psychometrically ascertained schizotypic individuals and renders support for the past reports of working memory deficit in schizophrenia and schizotypy.

Phagocytic cell molecules that bind the collagen-like region of C1q. Involvement in the C1q-mediated enhancement of phagocytosis.

C1q binds to and elicits cellular responses by several cell types, including monocytes, macrophages, neutrophils, B cells, and fibroblasts. The cell-binding domain is located within the collagen-like pepsin-resistant region of the C1q molecule (C1q tails). An affinity matrix of C1q tails coupled to Sepharose was used to select C1q-binding proteins from detergent extracts of surface-iodinated human monocytes, polymorphonuclear leukocytes, and the U937 cells. The major radiolabeled polypeptide eluted specifically from the ligand affinity column had an apparent molecular mass (Mr) of 126,000. Minor iodinated components eluted from Sepharose-tails migrated with Mr of 216,000 and 55,000. When subjected to sodium dodecyl sulfate-polyacrylamide gel electrophoresis under reducing conditions no change in the migration of any of these polypeptide bands was detected. None of these polypeptides reacted with antibodies directed against the integrins alpha 5 beta 1 (fibronectin receptor) or alpha v beta 3 (vitronectin receptor), LFA-1, or to several other cell adhesion molecules. The Mr 126,000 band was found to contain more than one polypeptide. Lectin binding properties, susceptibility to glycosidases and proteases, and immunoreactivity with the monoclonal antibody L-10, indicated that CD43 (sialophorin/leukosialin) is a component of this band. However, further data show that a monoclonal antibody, generated by immunization with the isolated Clq-binding fractions, recognizes a cell surface sialoglycoprotein distinct from CD43 and inhibits the C1q-mediated enhancement of phagocytosis in monocytes. These latter observations provide the first definitive connection between a specific phagocytic cell surface protein and a known C1q-mediated function. While these proteins contain sialic acid, binding assays and functional assays using neuraminidase-treated cells demonstrate that the functional interaction between C1q and the cell surface is not via sialic acid. The data taken together indicate either that the functional C1q receptor on phagocytic cells is a multi-subunit complex or that multiple proteins can interact with the fragment of C1q containing the cell-binding domain, at least one of which is involved in the C1q-mediated enhancement of phagocytosis.

Primary structure of alpha 2-macroglobulin receptor-associated protein. Human homologue of a Heymann nephritis antigen.

The alpha 2-macroglobulin (alpha 2M) receptor complex as purified by affinity chromatography contains three polypeptides: a 515-kDa heavy chain, an 85-kDa light chain, and a 39-kDa associated protein. Previous studies have established that the 515/85-kDa components are derived from a 600-kDa precursor whose complete sequence has been determined by cDNA cloning (Herz, J., Hamann, U., Rogne, S., Myklebost, O., Gassepohl, H., and Stanley, K. (1988) EMBO J. 7,4119-4127). We have now determined the primary structure of the human 39-kDa polypeptide, termed alpha 2M receptor-associated protein, by cDNA cloning. The deduced amino acid sequence contains a putative signal sequence that precedes the 323-residue mature protein. Comparative sequence analysis revealed that alpha 2M receptor-associated protein has 73% identity with a rat protein reported to be a pathogenic domain of Heymann nephritis antigen gp 330 and 77% identity to a mouse heparin-binding protein termed HBP-44. The high overall identity suggests that these molecules are interspecies homologues and indicates that the pathogenic domain, previously thought to be a portion of gp 330, is in fact a distinct protein. Further, the 120-residue carboxyl-terminal region of alpha 2M receptor-associated protein has 26% identity with a region of apolipoprotein E containing the low density lipoprotein receptor binding domain. Pulse-chase experiments revealed that the newly formed alpha 2M receptor-associated protein remains cell-associated, while surface labeling experiments followed by immunoprecipitation suggest that this protein is present on the cell surface forming a complex with the alpha 2M receptor heavy and light chains.