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The efficacy of benzalkonium chloride and sodium hypochlorite against Acanthamoeba polyphaga and two Tetrahymena spp. was determined based on the European Standard EN 1276:2009 suspension test. Trophozoite viability was assessed by determination of the membrane integrity using flow cytometry as a fast screening technique. Bovine serum albumin was added to simulate clean (0.3 g/liter) and dirty (3 g/liter) conditions. Benzalkonium chloride caused cell lysis at concentrations above 50 mg/liter under clean and dirty conditions. A concentration of 50 mg of free chlorine per liter had a strong biocidal effect on acanthamoebae and tetrahymenae after 15 min under clean and dirty conditions. Our results suggest that benzalkonium chloride and sodium hypochlorite were effective against the three microorganisms at concentrations commonly applied in the food industry.

Infection of murine PU5-1.8 macrophages and human monocytes by influenza A virus was associated with virus replication, release of tumor necrosis factor-alpha (TNF-alpha) and subsequent cell death. In the presence of small and by itself rather inefficient concentrations of lipopolysaccharide (LPS) or free lipid A (1 to 10 ng/ml), TNF-alpha production of virus-infected macrophages was strongly potentiated. LPS-triggered and enhanced TNF-alpha release from virus-infected macrophages was neither due to increased cell survival nor altered virus replication, potentiated TNF-alpha gene transcription, release of intracellularly stored TNF-alpha or shifts in the kinetics of TNF-alpha secretion. Influenza A virus infection alone induced a massive TNF-alpha mRNA accumulation which, however, was only weakly translated into bioactive TNF-alpha protein. When these virus-primed macrophages were exposed to LPS either simultaneously or up to 4 h after infection, an efficient and high translation into TNF-alpha protein occurred. Although the LPS-induced biochemical pathways leading to an augmented TNF-alpha production by virus-infected macrophages still remains unsolved, the findings suggest that the frequently observed serious clinical complications in the course of combined influenza A virus and bacterial infections may be due, at least in part, to an excessive release of cytokines such as TNF-alpha.

Infections by coxsackie virus B3 (CVB3) have been reported to be associated with an enhanced influx of mononuclear leukocytes into afflicted tissue. Current evidence indicates that monocytes/macrophages are specifically involved in CVB3-induced myocarditis by maintaining a chronic inflammatory response. To examine susceptibility and reactivity to CVB3, freshly isolated human monocytes were exposed to various virus doses (0.1-10 MOI) in the presence or absence of macrophage-activating lipopolysaccharide (LPS). CVB3 infection alone induced an activation of monocytes as evidenced by enhanced adherence, release of cytokines and secretion of prostaglandin E2 (PGE2). Simultaneous addition of LPS almost entirely suppressed LPS-specific production of tumour necrosis factor alpha (TNF alpha) and PGE2, partially inhibited release of interleukin 1 beta (IL 1 beta) and did not affect interleukin 6 (IL6) synthesis of CVB3-infected monocytes. These data show that CVB3 activates monocytes to cytokine production but renders them unreactive to further activating stimuli. Further studies should determine the extent to which continuous cytokine release from persistently CVB3-infected monocytes, and their apparent unresponsiveness to other stimuli, contribute to chronic myocarditis.

Intravenous administration of a total dose of more than 200 million IU of penicillin-G led to sensitisation of lymphocytes and formation of specific anti-penicilloyl antibodies of the IgG class. These effects were prevented when the penicillin solution used was freshly prepared and given as a bolus rather than as a slow infusion. The causative antigens seem to be related not to penicilloylated high molecular weight impurities in the penicillin preparations, but to the degradation and/or transformation products of penicillin-G that form when the drug is in solution even if only for a few hours, and not only at room temperature but also at 4 degrees C. Thus penicillin solutions should be freshly prepared and administered from vials containing less than 10 million IU so that bolus doses can be given.

A flow-cytofluorometric technique is described for determining active and total rosettes formed by sheep red blood cells with human peripheral blood lymphocytes. This technique correlates well with the microscopic determination of active rosettes, when these are defined as three or more erythrocytes per lymphocyte, and with the determination of total rosettes, when these are defined as four or more erythrocytes per lymphocyte. In the small group of tumor patients tested, the observed decrease in capacity to form active rosettes was found to be dependent on the individual sheep red blood cells used, while the levels of total rosettes were not affected by individual SRBC's and were not significantly different from those of normal blood donors. Flow-cytometry is a rapid, reproducible and objective technique, which permits better measurement than microscopy of total and active rosette levels in both normal donors and cancer patients.