Pulmonary surfactant proteins and lipids as modulators of inflammation and innate immunity

Objectives: The pulmonary surfactant system of the human lung consists of unique lipids and proteins that contribute to the biophysical and innate immune properties of the organ. Surfactant protein A (SP‐A) is an oligomeric protein consisting of 18 protomers with collagen and lectin–like domains that recognizes glycoconjugates, lipids and protein determinants on both host cells and invading microorganisms. The authors examined the interaction of SP‐A with Mycoplasma pneumoniae and the influence of the protein upon the innate immune response to the bacteria. Methodology: The authors quantified SP‐A interaction with bacteria using ELISA, and identified the major surface ligand by thin layer chromatography, HPLC and mass spectrometry. The inflammatory response of human and rat macrophages was measured by quantifying tumour necrosis factor‐α secretion using ELISA, and nitric oxide production. Results: SP‐A bound the bacteria with high affinity and enhanced the inflammatory response of human and rat macrophages to the organism and its membranes. Analysis of the interaction of SP‐A with the bacteria revealed that the major ligand was a phospholipid. The lipid ligand was purified by a combination of thin layer and HPLC, and identified by mass spectrometry. The mass spectrometry demonstrated that the SP‐A reactive lipid consisted of several disaturated molecular species of phosphatidylglycerol (PtdGro). Additional experiments were performed to determine if disaturated PtdGro was capable of interfering with the action of SP‐A as an inhibitor of bacterial lipopolysaccharide‐induced inflammatory mediator production by macrophages. The disaturated PtdGro failed to alter the anti‐inflammatory action of SP‐A but unexpectedly these same studies revealed that unsaturated PtdGro can modify the host response to lipopolysaccharide. Conclusions: These findings reveal that both the lipids and proteins of pulmonary surfactant play a role in regulating the host response to invading microorganisms.     

The use of aversive stimuli in treatment: the issue of consent*

ABSTRACT. It has been argued that, in the consideration ofthe use of aversive stimuli in treatment, the issues are ideological and philosophical as well as technical. Adopting Homer's (1990) definition of what is meant by‘aversive’in the ideological debate, it is suggested that the crucial issue is the inability of making clients to give their informed consent. It is proposed that proxy consent might be an alternative, but that this would be unacceptable if aversive procedures could be shown to be never'm the best interests ofthe client, or shown to violate clients’rights or to be against the interests of society because of anticipated harm or injustice to others. It is concluded that it is difficult to be certain that it is ever in the best interests ofthe client for aversive procedures to be employed, that aversive interventions appear not to violate clients’rights necessarily (except possibly the right to dignity and respect while the intervention is operating, and perhaps the right to choice at the beginning of the intervention), but that the inescapable difficulty in the use of aversive interventions is the likelihood that they will be misused with other clients than the ones for whom they may be initially designed.     

Unilateral linear capillaritis

We present four cases of a distinctive type of pigmented purpuric eruption occurring in a striking linear and pseudo-dermatomal distribution in young males. Whilst these cases share some of the clinical and histological features of other pigmented purpuric dermatoses, they are not readily classified with any of the entities so far defined in this group of disorders. We believe these cases represent a distinct group not previously described. Four patients with an unusual pigmented purpuric eruption are presented.