Search

Objective: The aim of this study was to analyse wound biofilm from a clinical perspective. Research has shown that biofilm is the preferred microbial phenotype in health and disease and is present in a majority of chronic wounds. Biofilm has been linked to chronic wound inflammation, impairment in granulation tissue and epithelial migration, yet there lacks the ability to confirm the clinical presence of biofilm. This study links the clinical setting with microscopic laboratory confirmation of the presence of biofilm in carefully selected wound debridement samples., Method: Human wound debridement samples were collected from adult patients with chronic non-healing wounds who presented at the wound care centre. Sample choice was guided by an algorithm that was developed based on what is known about the characteristics of wound biofilm. The samples were then evaluated by light microscopy and scanning electron microscopy for the presence of biofilm. Details about subject history and treatment were recorded. Adherence to biofilm-based wound care (BBWC) strategies was inconsistent. Other standard antimicrobial dressings were used and no modern antiseptic wound dressings with the addition of proven antibiofilm agents were available for use., Results: Of the patients recruited, 75% of the macroscopic samples contained biofilm despite the prior use of modern antiseptic wound dressings and in some cases, systemic antibiotics. Wounds found to contain biofilm were not all acutely infected but biofilm was present when infection was noted. The clinical histories associated with positive samples were consistent with ideas presented in the algorithm used to guide sample selection., Conclusion: Visual cues can be used by the clinician to guide suspicion of the presence of wound biofilm. This suspicion can be further enhanced with the use of a clinical algorithm. Standard antiseptic wound dressings used in this study demonstrated limited antibiofilm efficacy. This study also highlighted a need for the clinical team to focus on expiration of dressing action and consistent practice of BBWC strategies which includes the use of proven antibiofilm agents.

The porcine T-cell population is unique in that there is a large percentage of CD+CD8+ dual expressing peripheral T-cells. This paper reviews the data available on these porcine T-cells and compares them to the much rarer dual expressing T-cells in humans. The percent of dual expressing cells increases with activation in in vitro culture with various antigens including pseudorabies virus. The percent of resting dual expressing cells also increases with the age of the pig. Flow-cytometric-sorted dual expressing cells responded in culture to the super antigen staphylococcal enterotoxin B. Selected CD4+CD8- cells cultured in vitro developed expression of CD8 and maintained the dual expressing phenotype for the 12 weeks of culture. Dual expressing cells freshly prepared from porcine blood did not express the IL-2 receptor as demonstrated by their failure to bind FITC-IL-2 and an anti-porcine IL-2 receptor monoclonal antibody. In response to activation with phorbol myristic acetate, CD4, but not CD8, was down regulated on the dual expressing T-cells. In summary, porcine dual expressing T-cells constitute a substantial percentage of the porcine peripheral T-cell pool. These cells appear to contain the majority of the memory T-cell with their frequency increasing with blood donor age and in vitro culture. Although the receptor specificity is not known, they have a functional receptor. Finally, the function of the two accessory molecules CD4 and CD8 in these cells is not known, but their regulation is distinct, thereby suggesting no equivalent roles in immune function.

To plan an I/S strategy without sufficient communications capabilities omits a vital link to success. At Lehigh Valley Hospital in Allentown, Pa., information services experts are building a network foundation to support today's strategic plan as well as tomorrow's technology.