Coated Cast Saw Blades Decrease Blade Temperature During Cast Removal.

BACKGROUND: Thermal injuries can occur during cast removal with an oscillating saw. The purpose of this study is to describe the effect of blade material, blade wear, and cast material on blade temperature. METHODS: Short arm plaster and fiberglass casts were cured overnight and bivalved with either new or worn stainless-steel or tungsten-disulfide coated blades. Blade use was defined as removing 1 short arm cast. Blades used to remove more than 20 casts were defined as worn. Ten trials were performed with each combination of blade material, blade wear, and cast material, except for the combination of fiberglass and a worn stainless-steel blade due to complete erosion of cutting teeth. Thirty casts were removed with stainless-steel blades, and 40 casts were removed with coated blades. Blade temperature was measured continuously at 5 Hz using a T-type thermocouple and microcontroller board. A Mann-Whitney U test was used to compare the mean maximum temperature between groups. RESULTS: For plaster casts, new and worn stainless-steel blades produced mean maximum temperatures of 51.4°C and 63.7°C ( P =0.003), respectively. New stainless-steel blades produced significantly higher mean maximum temperatures on fiberglass casts than plaster casts (95.9°C vs. 51.4°C, P <.001). For plaster casts, new and worn coated blades produced mean maximum temperatures of 56.9°C and 53.8°C ( P =0.347). For fiberglass casts, new and worn coated blades produced mean maximum temperatures of 76.6°C and 77.7°C ( P =0.653). As with new stainless-steel blades, new coated blades produced significantly higher mean maximum temperatures on fiberglass than plaster (76.6°C vs. 56.9°C, P <0.001). Mean maximum temperatures between new stainless-steel and coated blades during removal of plaster casts were 51.4°C and 56.9°C ( P =0.131), respectively. However, new coated blades demonstrated significantly lower mean maximum temperatures during fiberglass cast removal compared to new stainless-steel blades (76.6°C vs. 95.9°C, P =0.016). CONCLUSIONS: Coated blades outperformed stainless-steel in nearly all combinations. We recommend limited use of stainless-steel blades to minimize blade temperatures during cast removal. CLINICAL RELEVANCE: Appropriate selection of blade material and monitoring blade wear minimizes blade temperature during cast removal.

Coaggregation occurs between microorganisms isolated from different environments.

Coaggregation, the specific recognition and adherence of different microbial species, is thought to enhance biofilm formation. To date, no studies have focused on the ability of microorganisms isolated from a broad range of environments to coaggregate with each other and it is unclear whether coaggregation promotes the transmission of microorganisms between environmental niches. We aimed to evaluate the coaggregation ability of 29 bacteria and one fungus, isolated from a range of different environments, and to characterize the cell-surface polymers that mediate coaggregation between selected pairs. Strains were categorized as belonging to one of the four microbial archetypes: aquatic, broad environment, human opportunistic pathogen or human oral. A total of 23 of the 30 strains (77%) coaggregated with at least one other and 21/30 (70%) coaggregated with strains belonging to other archetypes. Nasopharyngeal bacteria belonging to the human opportunistic pathogen archetype showed the least number of coaggregations, and five Haemophilus influenzae strains did not coaggregate. Protease and sugar treatments indicated that coaggregation between strains of different archetypes was often mediated by lectin-saccharide interactions (9 of 15 evaluated pairs). In conclusion, coaggregation can occur between taxonomically disparate species isolated from discrete environments. We propose that these organisms be labeled as 'cross-environment coaggregating organisms'. The ability to coaggregate may aid species to colonize non-indigenous biofilms.

VS411 reduced immune activation and HIV-1 RNA levels in 28 days: randomized proof-of-concept study for antiviral-hyperactivation limiting therapeutics.

BACKGROUND: A new class of antiretrovirals, AntiViral-HyperActivation Limiting Therapeutics (AV-HALTs), has been proposed as a disease-modifying therapy to both reduce Human Immunodeficiency Virus Type 1 (HIV-1) RNA levels and the excessive immune activation now recognized as the major driver of not only the continual loss of CD4(+) T cells and progression to Acquired Immunodeficiency Syndrome (AIDS), but also of the emergence of both AIDS-defining and non-AIDS events that negatively impact upon morbidity and mortality despite successful (ie, fully suppressive) therapy. VS411, the first-in-class AV-HALT, combined low-dose, slow-release didanosine with low-dose hydroxycarbamide to accomplish both objectives with a favorable toxicity profile during short-term administration. Five dose combinations were administered as VS411 to test the AV-HALT Proof-of-Concept in HIV-1-infected subjects. METHODS: Multinational, double-blind, 28-day Phase 2a dose-ranging Proof-of-Concept study of antiviral activity, immunological parameters, safety, and genotypic resistance in 58 evaluable antiretroviral-naïve HIV-1-infected adults. Randomization and allocation to study arms were carried out by a central computer system. Results were analyzed by ANOVA, Kruskal-Wallis, ANCOVA, and two-tailed paired t tests. RESULTS: VS411 was well-tolerated, produced significant reductions of HIV-1 RNA levels, increased CD4(+) T cell counts, and led to significant, rapid, unprecedented reductions of immune activation markers after 28 days despite incomplete viral suppression and without inhibiting HIV-1-specific immune responses. The didanosine 200 mg/HC 900 mg once-daily formulation demonstrated the greatest antiviral efficacy (HIV-1 RNA: -1.47 log(10) copies/mL; CD4(+) T cell count: +135 cells/mm(3)) and fewest adverse events. CONCLUSIONS: VS411 successfully established the Proof-of-Concept that AV-HALTs can combine antiviral efficacy with rapid, potentially beneficial reductions in the excessive immune system activation associated with HIV-1 disease. Rapid reductions in markers of immune system hyperactivation and cellular proliferation were obtained despite the fact that VS411 did not attain maximal suppression of HIV RNA, suggesting this effect was due to the HALT component. TRIAL REGISTRATION: ITEudraCT 2007-002460-98.