Systemic administration of Abeta mAb reduces retinal deposition of Abeta and activated complement C3 in age-related macular degeneration mouse model.

Age-related macular degeneration (AMD) is a leading cause of legal blindness in the Western world. There are effective treatments for the vascular complications of neo-vascular AMD, but no effective therapies are available for the dry/atrophic form of the disease. A previously described transgenic CFH-gene deficient mouse model, (cfh-/-), shows hallmarks of early AMD. The ocular phenotype has been further analysed to demonstrate amyloid beta (Aß) rich basement membrane deposits associated with activated complement C3. Cfh-/- mice were treated systemically in both prophylactic and therapeutic regimes with an anti-Aß monoclonal antibody (mAb), 6F6, to determine the effect on the cfh-/- retinal phenotype. Prophylactic treatment with 6F6 demonstrated a dose dependent reduction in the accumulation of both Aß and activated C3 deposition. A similar reduction in the retinal endpoints could be seen after therapeutic treatment. Serum Aß levels after systemic administration of 6F6 show accumulation of Aß in the periphery suggestive of a peripheral sink mechanism. In summary, anti-Aß mAb treatment can partially prevent or reverse ocular phenotypes of the cfh-/- mouse. The data support this therapeutic approach in humans potentially modulating two key elements in the pathogenesis of AMD - Aß and activated, complement C3.

Dipeptidyl nitrile inhibitors of Cathepsin L.

A series of potent Cathepsin L inhibitors with good selectivity with respect to other cysteine Cathepsins is described and SAR is discussed with reference to the crystal structure of a protein-ligand complex.

Overcoming barriers to oxygen saturation targeting.

OBJECTIVE: To reduce hyperoxia in very low birth weight infants who receive supplemental oxygen, the Children's Mercy Hospital neonatal respiratory quality improvement committee introduced the potentially better practice of oxygen saturation targeting and identified strategies to overcome barriers to implementation of this practice. METHODS: Using rapid-cycle quality improvement projects, this center adapted an oxygen saturation targeting protocol and tracked hourly oxygen saturation as measured by pulse oximetry in very low birth weight infants who received supplemental oxygen. RESULTS: The percentage of time in the range of 90% to 94% of oxygen saturation as measured by pulse oximetry increased from 20% to an average of 35% after implementation of the protocol. The percentage of time with oxygen saturation as measured by pulse oximetry >98% dropped from 30% to an average of 5% to 10%. CONCLUSIONS: A well-planned strategy for implementing oxygen saturation targeting can result in a sustained change in clinical practice as well as change in the culture of the NICU regarding the use of oxygen.

Standardizing nasal cannula oxygen administration in the neonatal intensive care unit.

OBJECTIVE: A multicycle, quality improvement method was used to standardize nasal cannula O2 administration and weaning in the NICU. METHODS: A 2-armed nasal cannula standardized order form (nasal cannula for stable O2 arm and nasal cannula for stable flow arm) was developed after review of the literature, surveying of the practice of NICU physicians and nurse practitioners, and development of consensus among these providers. Outcomes were measured by tracking the distribution of protocol arm chosen, days on O2, weeks on nasal cannula, and disposition of infants who were supported by nasal cannula. Data were collected in an SPSS statistical data set. RESULTS: Of the 90 infants evaluated, 12 were supported on the stable O2 arm and 53 on the stable flow arm for their entire nasal cannula course. Twenty-five infants switched between arms of support. Patients who were on the stable flow arm of the standard order set for their entire nasal cannula course experienced fewer O2 days but more days on nasal cannula. A subpopulation of infants were supported on nasal cannula flow 0.5 to 1.0 L, with fraction of inspired O2 of 21%. When data from the first 10 weeks of observation were compared with that of the second 10 weeks, the rate of discharge on O2 had decreased from 13 (30%) of 44 to 3 (7%) of 39. CONCLUSIONS: The multiple steps of literature review, practice surveys, and consensus-building resulted in enthusiastic reception of the nasal cannula standardized order form. The 2-armed nasal cannula protocol forced caregivers to consider which method of support was most beneficial for each infant who was on nasal cannula and allowed a subpopulation of NICU patients to be supported with a lower fraction of inspired O2 than previously used in the NICU.

Biofilm-specific surface properties and protein expression in oral Streptococcus sanguis.

OBJECTIVE: Oral streptococci are primary colonisers of the tooth surface and are abundant in dental plaque biofilms. Bacteria growing in these relatively dense, surface-associated communities are phenotypically quite distinct from their planktonic counterparts. The purpose of the present study was to develop a method to investigate biofilm-specific surface protein expression by Streptococcus sanguis to help provide a better understanding of the critical events in plaque development. DESIGN: Biofilm cells were grown on the surface of glass beads in a biofilm device fed with mucin-containing artificial saliva. Planktonic cells were grown in continuous culture at approximately the same growth rate. Surface hydrophobicity of biofilm and planktonic cells was determined by hexadecane partitioning, and expression of streptococcal fibronectin adhesin CshA was determined in ELISA using specific antiserum. Antisera raised to glutaraldehyde-fixed whole biofilm or planktonic grown cells were used to screen an expression library of S. sanguis genomic DNA, and isolated clones were sequenced. RESULTS: Phenotypic analysis of biofilm and planktonic cells confirmed that mode of growth affected surface properties of S. sanguis. Thus, hydrophobicity and CshA expression was significantly elevated in biofilm cells. Library screening with biofilm antiserum yielded 32 recombinant clones representing 21 different S. sanguis proteins involved in adhesion and colonisation, carbohydrate utilisation or bacterial metabolism. In differential analysis of four selected Escherichia coli clones, biofilm antiserum reacted five times stronger than planktonic antiserum with cell-free extracts of clones encoding homologues of CshA and Cna collagen adhesin of Staphylococcus aureus, suggesting that these surface proteins are up-regulated in biofilm cells. In contrast, both antisera reacted equally strongly with cell-free extracts of the remaining two clones (encoding dihydrofolate synthase and an unknown protein). CONCLUSIONS: The method described represents a useful means for determining bacterial protein expression in biofilms based on a combination of molecular and immunological techniques. Surface expression of putative fibronectin and collagen adhesins was up-regulated in biofilm cells.