Benzene is an important industrial chemical and environmental contaminant that causes leukemia. To obtain mechanistic insight into benzene's mechanism of action, we examined the impact of benzene on the human serum proteome in a study of exposed healthy shoe-factory workers and unexposed controls. Two sequential studies were performed, each using sera from 10 workers exposed to benzene (overall mean benzene air level >30 ppm) and 10 controls. Serum samples were subjected to anion-exchange fractionation and bound to three types of ProteinChip arrays (Ciphergen Biosystems, Fremont, CA) [hydrophobic (H50), metal affinity (IMAC3-Cu), and cation exchange (WCX2)]. Protein-expression patterns were detected by surface-enhanced laser desorption͞ ionization (SELDI)-TOF MS. Three proteins (4.1, 7.7, and 9.3 kDa) were consistently down-regulated in exposed compared with control subjects in both studies. All proteins were highly inversely correlated with individual estimates of benzene exposure (r > 0.75). The 7.7-and 9.3-kDa proteins were subsequently identified as platelet factor (PF)4 and connective tissue activating peptide (CTAP)-III. Initial proteomic results for PF4 and CTAP-III were subsequently confirmed in a single experiment using a ProteinChiparray-based immunoassay(Ciphergen Biosystems). The altered expression of the platelet-derived CXC-chemokines (40% and 63% for PF4 and CTAP-III, respectively) could not be explained by changes in absolute platelet counts. Thus, SELDI-TOF analysis of a limited number of exposed and unexposed subjects revealed that lowered expression of PF4 and CTAP-III proteins is a potential biomarker of benzene's early biologic effects and may play a role in the immunosuppressive effects of benzene.biomarker ͉ leukemia ͉ mass spectrometry ͉ platelet ͉ molecular epidemiology

The effect of pre-fitting counselling on the outcome of fittings of NHS behind-the-ear hearing aids to adult first-time users was investigated. Questionnaires and diaries were sent both before and after fitting to 48 subjects who were given pre-fitting counselling and 47 control subjects, all of whom were fitted with standard NHS hearing aids in Southampton or Bath between September 1989 and July 1991. The test and control groups had similar distributions of age, sex and hearing loss. Analysis of the data showed that the counselling had no significant effect on levels of satisfaction, aid usage or benefit; these outcome measures also showed no significant correlation with any of the personal characteristics or attitude factors which were studied.

Dihydrohpoamide acetyl transferase (E2), a catalytic and structural component of a multienzyme complex that catalyzes the oxidative decarboxylation of pyruvate, forms the central core to which the other components are bound. We have utilized protein engineering and 3-D electron microscopy to study the structural organization of the largest multienzyme complex known (Mr ∼ 107). The structures of the truncated 60-mer core (tE2) and complexes of the tE2 associated with a binding protein (BP), and the BP associated with its dihydrohpoamide dehydrogenase (BP'E3) and the intact E2 associated with BP and the pyruvate dehydrogenase (E1) were determined (Figs. 1 and 2). The tE2 core is a pentagonal dodecahedron consisting of 20 cone-shaped trimers interconnected by 30 bridges.Previous studies have given rise to the generally accepted belief that BP and BP'E3 components are bound on the outside of the E2 scaffold and that E1 is similarly bound to the core in variable positions by flexible tethers.

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The reported HCC-associated changes in glycan flow and subcellular localization explain the increase in high mannose glycans and siayl Lewis glycans common in HCC liver tissues.