An outbreak of Salmonella typhimurium PTI35 gastroenteritis associated with a minimally cooked dessert containing raw eggs.

In April 2000, we investigated an outbreak of gastroenteritis amongst attendees of a local community dinner in a Perth suburb. Of the 98 people interviewed (response rate 98%), 53 reported gastrointestinal symptoms (attack rate 54%). Faecal cultures from 11 cases, 2 food preparers, 1 waitress and leftover mock ice-cream dessert grew Salmonella Typhimurium PT135. Of the 3 food handlers, one was asymptomatic, another gave an unclear history of onset of illness and the waitress claimed illness onset 9 days after the dinner. A cohort study implicated fruit salad (RR 1.64 [95% CI: 1.05-2.58], p=0.017) and/or mock ice-cream dessert (RR 1.78 [95% CI: 0.91-3.52], p=0.045). Eggs used to make the mock ice-cream dessert were supplied directly from the producer who used inappropriate shell cleaning methods. The method of preparation of the dessert encouraged contamination. Salmonella species were not isolated in poultry faecal samples collected from the implicated egg farm. The cause of this outbreak was almost certainly the ice-cream dessert with contamination most likely resulting either from the eggs used to make the dessert or one or both of the food preparers, coupled with inadequate cooking of the dessert. Eggs used in preparing food for mass consumption should be sourced from distributors with approved cleaning procedures. Furthermore, pasteurised egg products or egg pulp should be used in the preparation of uncooked or minimally cooked dishes.     

Anti-IgM induces transforming growth factor-beta sensitivity in a human B-lymphoma cell line: inhibition of growth is associated with a downregulation of mutant p53

We wished to examine the role of transforming growth factor-beta (TGF- beta) in the regulation of human lymphoma cell growth. The RL cell line is an immunoglobulin M (IgM)+, IgD+ B lymphoma cell line, which does not constitutively express receptors for TGF-beta, and thus has lost the ability to respond to the inhibitory effects of TGF-beta. We demonstrate here that anti-Ig antibodies can efficiently upregulate the expression of TGF-beta receptors and promote sensitivity to growth inhibition by TGF-beta. Furthermore, because TGF-beta has been shown to function in late G1 of the cell cycle, we examined the ability of TGF- beta to modulate two tumor suppressor proteins known to be critical regulators of the G1/S transition, Rb and p53. Rb is a 105- to 110-kD phosphoprotein, which has been shown to maintain its growth suppressive function when it is found in the hypophosphorylated state. Wild-type p53 is a 53-kD phosphoprotein that appears to be important in preventing cell-cycle progression and promoting apoptosis in cells with DNA damage, whereas mutant p53 can overcome those functions. We show here that TGF-beta treatment of phorbol myristate acetate (PMA) or anti- Ig-activated RL cells results in growth inhibition through a dual effect on Rb and mutant p53. After TGF-beta treatment, we observe a predominance of Rb in the hypophosphorylated, growth suppressive form. In addition, we show a decrease in levels of mRNA and protein for mutant p53. We also show that, although these changes are sufficient to halt progression through the cell cycle, the cells do not appear to undergo extensive programmed cell death following 72 hours of TGF-beta treatment. Thus, although these lymphoma cells maintain the capacity to be negatively growth regulated by TGF-beta, the ability of TGF-beta to induce apoptosis must be independently controlled.     

Performance of 'Micro-Bumintest' tablets for detection of microalbuminuria in Nauruans

Subclinical elevation of urinary albumin excretion (microalbuminuria) is useful for the detection of individuals at high risk of developing nephropathy in both insulin-dependent and non-insulin-dependent diabetes mellitus. We have evaluated the performance of Micro-Bumintest, a semi-quantitative test for the rapid detection of microalbuminuria. A total of 1186 samples from a population-based survey of the high diabetes prevalence community of Nauru were studied. Compared with a radioimmunoassay method, the Micro-Bumintest had a sensitivity of 97.6%, specificity of 93.2% and overall efficiency of 94.8%, when 40 micrograms/ml was used as the discriminating albumin concentration defining microalbuminuria. Significant differences in radioimmunoassay results between categories of the Micro-Bumintest were found, indicating its usefulness as a semi-quantitative test. Compared with subjects with normal glucose tolerance, there was a statistically significant progressive increase in the prevalence of microalbuminuria as detected by Micro-Bumintest in subjects with impaired glucose tolerance and diabetes mellitus. Micro-Bumintest performs well as a screening test for detection of microalbuminuria not only in the clinical situation, but also in population-based epidemiological studies.     

Blood flow imaging with MR: spin-phase phenomena

Blood flow phenomena occurring when flow is within the magnetic resonance (MR) imaging plane were analyzed. In this situation, the signal intensity of vascular lumina is predominantly determined by spin-phase change phenomena, and section transition effects of moving spins can be neglected. In this paper, we develop the concepts of in-plane flow, with emphasis on the notion that the spatial variations in velocity and acceleration of blood, which mainly occur along vessel walls, are important determinants of intravascular signal loss in MR images. Flow patterns in the large mediastinal arteries were qualitatively and quantitatively analyzed in six healthy subjects and 14 patients with hemodynamic abnormalities using multiple electrocardiograph-gated image acquisition; ungated studies of 30 patients were analyzed for venous flow effects. Intraluminal signal was strongly dependent on the phase of the cardiac cycle and the echo number. Signal loss was found to occur along vessel walls, in vascular bends, and at bifurcations.