A prospective study of the development of coronary heart disease in a group of 1202 middle-aged men.

A prospective study of the development of coronary heart disease (CHD) in men aged 45--54 was conducted in six group practices in Belfast, Northern Ireland Of the 1343 men examined once by clinical, electrocardiographic, biochemical and anthropometric methods, 1202 free from CHD entered the prospective study. All 1202 men were followed for at least five years and the average annual incidence of CHD during this period was estimated as 1.73% (104 men developed). Of the 28 measurements made at initial examination, four--S-T depression, total lifetime tobacco consumption, diastolic blood pressure, and height (significant on classical linear discriminant function analysis)--were investigated in more detail. Using multidimensional contingency table methods, the probability of developing CHD was found to depend, in rand order of importance, on S-T depression, total lifetime tobacco consumption, and diastolic blood pressure. The risk of development was maximal (0.3732, four times the 'random' risk) in men with S-T depression, greater than average total lifetime tobacco consumption, and a diastolic pressure of 100 mm Hg or more.     

Bone scan findings in hypervitaminosis D: case report

Bone scans in three patients showed generalized symmetrical increased uptake of radiopharmaceutical by the skeleton and absent or faint kidney images. It is thought that these appearances may be attributable to excess vitamin D, but other possible contributing factors, including the presence of renal osteodystrophy, are discussed.     

The binding and processing of monoclonal human IgG1 by cells of a human macrophage-like cell line (U937)

The goal of these experiments was to assess the relationship between the binding and processing of IgG by Fc-receptor-bearing cells. Cells of the U937 human macrophage-like cell line were incubated with 125I- labeled monomers, dimers, oligomers (composed of 2-4 IgG1 subunits), and HP (heavy polymers composed of 5 or more subunits per polymer) of monoclonal human IgG1 in vitro. Binding was assessed by spinning cells through a layer of phthalate oils. Internalization of IgG1 was assessed by quantitating residual binding to cells after surface-bound IgG was removed by a brief treatment with a solution containing 0.25 M acetic acid and 0.5 M sodium chloride. Catabolism was assessed by measuring the release of radioactive fragments of IgG1, which were not precipitated by 10% trichloroacetic acid. Unstimulated U937 bound about 10,000 molecules per cell of IgG1 monomer, with an equilibrium binding constant (Ka) of 5 X 10(8) M-1. After stimulation with a conditioned medium in vitro, binding per cell was increased 3-7--fold, and the Ka was decreased 2-4--fold. Both unstimulated and stimulated cells internalized and catabolized labeled IgG1 HP, but stimulated cells internalized and digested much more IgG1 HP per cell than unstimulated cells. Both monomers and dimers of IgG1 were internalized and degraded very slowly by stimulated cells, even though both preparations readily bound to cells. In contrast, oligomers and (to an even greater extent) IgG1 HP were internalized and degraded much more rapidly. Internalization of IgG1 HP was markedly inhibited by incubation at 4 degrees C, but not by incubation with a variety of metabolic inhibitors. Catabolism was inhibited by chloroquine and monensin (inhibitors of lysosomal acidification) and by cytochalasin (an inhibitor of microfilament polymerization). Binding to the surface of cells was not markedly inhibited by any agent tested. The capacity of cells to bind labeled IgG1 was markedly reduced by prior incubation in the presence of unlabeled IgG1. This reduction was in part due to the steric blockade of receptors caused by the avid, but reversible, binding of IgG1. In addition, IgG1 oligomers or HP (but not IgG1 monomers or dimers) also caused an irreversible reduction in the number of Fc receptors by a process analogous to receptor down-regulation, as observed in other receptor--ligand systems.     

Control strategies for Q fever based on results of pre-vaccination screening in Victoria, 1988 to 2001

OBJECTIVE: Data from Q fever pre-vaccination screening were analysed to determine the level of agreement between the two tests of immunity and between disease or vaccination history and immunity, trends in proportion of participants immune to Q fever, and the annual risk of infection. METHOD: Data from nearly 10,000 screening episodes between July 1988 and June 2001 on Victorian workers at high risk were assessed. RESULTS: Most participants were male (86%) and employed in Victorian abattoirs (81%). Agreement between results of tests for immunity was 'fair' (kappa=0.52). Self-reported history of vaccination or infection was a poor predictor of immunity. The proportion of positive blood and skin tests increased with years of exposure to animals/meat, but decreased over the 13-year period with shorter exposures. Hence the percentage requiring vaccination increased from 50% in 1998 to 90% in 2001. The average annual risk of infection among abattoir workers was 45.0 per 1,000 (95% CI 42.3-47.6), and 62.6 per 1,000 (95% CI 57.5-67.7) over the first 10 years of exposure. CONCLUSIONS: This is the first Australian study to estimate the annual risk of Q fever infection in abattoir workers. The study confirmed previous findings of poor agreement between screening tests and predictive value of history of vaccination/ exposure. Up to 90% of new entrants in high-risk workplaces will be susceptible to Q fever and require vaccination. IMPLICATIONS: Systematic post-marketing surveillance is needed to monitor adverse events to the vaccine, duration of protection and possible reasons for vaccine failures.