Syncope in children with Tourette's syndrome treated with guanfacine.

We report on 4 children who experienced a syncopal episode while being treated with guanfacine without any other evident cause. Syncope appears to be an uncommon side effect of guanfacine and is probably due to drug-induced hypotension or bradycardia.     

Etanercept decreases tumor necrosis factor-α activity in chronic wound fluid

High levels of tumor necrosis factor-alpha (TNF-alpha), a pro-inflammatory cytokine, are present in the wound fluid of chronic nonhealing wounds. This leads to increased inflammation, cytokine expression, and ultimately results in impaired wound healing and tissue destruction. Etanercept is a recombinant fusion protein that consists of the soluble TNF receptor (p75) linked to the Fc portion of human IgG1. It is an effective inhibitor of TNF-alpha and has been shown to provide rapid and sustained improvement in rheumatoid arthritis by acting as a soluble receptor binding TNF-alpha and preventing its proinflammatory activities. Therefore, the aim of this study was to determine whether Etanercept could inhibit TNF-alpha activity in chronic wound fluid. Wound fluid was collected from the venous leg ulcers of 16 different patients. The effect of Etanercept on TNF-alpha activity was evaluated using both a TNF-alpha bioassay and an enzyme-linked immunoassay. Etanercept was found to reduce the cytotoxic effect of chronic wound fluid on L929 fibroblasts by approximately 30% and neutralized TNF-alpha binding in the enzyme-linked immunoassay by up to 80%. Direct application of Etanercept to chronic wounds may therefore reduce the inflammatory activity of TNF-alpha, which could reduce the chronicity of venous leg ulcers and thus aid in the healing of these wounds.     

Gingival crevicular fluid IL-8: correlation with local IL-1β levels and patient estrogen status

Gingival crevicular fluid (GCF) IL-8 and IL-1,1β levels were determined by sandwich enzyme-linked immunosorbent assays. Associations between IL-8 and IL-1β GCF levels, and between these cytokines and patient estrogen status were evaluated. IL-8 and IL-1β were detected more frequently and in higher amounts/30 s GCF sample in estrogen-deficient patients than in estrogensufficient patients. IL-8 and IL-1β GCF levels were significantly correlated. These lindings suggest that GCF IL-8 levels are associated with patient estrogen status and local IL-1β concentrations.     

Practitioner care and screening guidelines for infants born to chlamydia-positive mothers

Chlamydia trachomatis is the most prevalent sexually transmitted microbial infection in the United States. The CDC estimates that 3 million people are infected annually, with approximately 50% of infected men and 75% of infected women having few or no recognized symptoms. C. trachomatis is frequently transferred from mother to infant, and the maternal-infant transfer of this disease may have negative consequences for the newborn, such as prematurity, pneumonia, and conjunctivitis. Ocular prophylaxis with silver nitrate and or antibiotics is ineffective in preventing neonatal chlamydial conjunctivitis. By increasing awareness of the potential adverse consequences, initiating screening and treatment of pregnant women, and advocating for newborn assessment and treatment, nurses can enhance the quality of care for mothers and their infants.     

Immunology

A selection of interesting papers that were published in the two months before our press date in major journals most likely to report significant results in immunology.     

Epikeratophakia without annular keratectomy

Nineteen patients (20 eyes) underwent epikeratophakia for correction of high myopia. In contrast to the conventional surgical method utilizing an annular keratectomy, no keratectomy was performed in these patients. The surgical procedure is discussed. Preliminary results (up to six months) indicate that the omission of an annular keratectomy has no effect on graft clarity or viability. The weighted-average percent correction over six months postoperatively was 102%.     

The development of whole cell biosensors for on-line screening of herbicide pollution of surface waters

The use of mediator assisted amperometric whole-cell biosensors, monitoring microbial photosynthetic electron transfer, to screen for herbicides in intake protection by the water industry is described. Cells harvested from axenic cultures are loaded onto bacteriological filters and held against a working carbon electrode polarised against the silver chloride reference. Redox mediators are reduced by the microorganisms and then reoxidised at the working electrode resulting in a flow of current. For on-line applications the sensors are controlled by a programmable electrochemical analyser (Artek) and housed in specially designed perspex flow cells which incorporate light emitting diodes (LEDs) for photosynthetic stimulation. A range of cyanobacteria and algae have been tested, but biosensors incorporating unicellular cyanobacteria have proven the most successful. Results obtained using the cyanobacterium Synechococcus show detection levels of less than 200 ppb with response times of less than ten minutes for selected herbicides. Sensor stability in the absence of pollutant poisoning has been found to be greatly influenced by the choice of mediator. Membrane penetrating mediators such as -benzoquinone reduce sensor life to about 24 hours, while a sensor life of up to six days has been achieved with ferricyanide.