A Serum Factor Reacting with Acriflavin Causing an Error in ABO Cell Grouping

The blood of a donor was investigated because of a discrepancy between cell grouping and serum confirmation. Her whole blood reacted strongly with five commercial preparations of anti-B sera, yet her serum contained normal anti-B isoagglutinins. Grouping tests with the donor's washed red cells suspended in saline indicated they were group O. Further tests of the donor's whole blood showed that raw high titered anti-B did not cause agglutination. The addition of acriflavin (the dye used to color commercial preparation of anti-B) to the donor's blood caused spontaneous agglutination. The donor's serum plus acriflavin caused agglutination of all random group O red cells. Various antibiotics, drugs and vitamins such as riboflavin, cyanocobalamin, tetracycline, penicillin, chloromycetin, mycostatin, gantrisin, streptomycin, phenacetin, atabrine and quinidine did not cause agglutination.
The serum, when tested against her own cells or random group O cells in the presence of acriflavin, was reactive at a titer of 1:64; the reaction was not positive by the antiglobulin test. 2-Mercaptoethanol destroyed the reactivity of the serum. Inasmuch as the reaction was not complement dependent or enzyme affected, the phenomenon of immune adherence was ruled out. One year later her serum was still reactive at a titer of 1:32.
No other example of this serum factor was found in 1,000 random hospital patients.
An antigen-antibody reaction comparable to that observed in phenacetin dependent reactions³ is postulated.     

Early Antibiotic Administration Is Associated with a Reduced Infection Risk When Combined with Primary Wound Closure in Patients with Open Tibia Fractures

BackgroundEarly administration of antibiotics and wound coverage have been shown to decrease the deep infection risk in all patients with Type 3 open tibia fractures. However, it is unknown whether early antibiotic administration decreases infection risk in patients with Types 1, 2, and 3A open tibia fractures treated with primary wound closure.Questions/purposes(1) Does decreased time to administration of the first dose of antibiotics decrease the deep infection risk in all open tibia fractures with primary wound closure? (2) What patient demographic factors are associated with an increased deep infection risk in Types 1, 2, and 3A open tibia fractures with primary wound closure?MethodsWe identified 361 open tibia fractures over a 5-year period at a Level I regional trauma center that receives direct admissions and transfers from other hospitals which produces large variation in the timing of antibiotic administration. Patients were excluded if they were younger than 18 years, had associated plafond or plateau fractures, associated with compartment syndrome, had a delay of more than 24 hours from injury to the operating room, underwent repeat débridement procedures, had incomplete data, and were treated with negative-pressure dressings or other adjunct wound management strategies that would preclude primary closure. Primary closure was at the descretion of the treating surgeon. We included patients with a minimum follow-up of 6 weeks with assessment at 6 months and 12 months. One hundred forty-three patients with were included in the analysis. Our primary endpoint was deep infection as defined by the CDC criteria. We obtained chronological data, including the time to the first dose of antibiotics and time to surgical débridement from ambulance run sheets, transferring hospital records, and the electronic medical record to answer our first question. We considered demographics, American Society of Anesthesiologists classification, mechanism of injury, smoking status, presence of diabetes, and Injury Severity Score in our analysis of other factors. These were compared using one-way ANOVA, chi-square, or Fisher’s exact tests. Binary regression was used to to ascertain whether any factors were associated with postoperative infection. Receiver operator characteristic curves were used to identify threshold values.ResultsIncreased time to first administration of antibiotics was associated with an increased infection risk in patients who were treated with primary wound closure; the greatest inflection point on that analysis occurred at 150 minutes, when the increased infection risk was greatest (20% [8 of 41] versus 4% [3 of 86]; odds ratio 5.6 [95% CI 1.4 to 22.2]; p = 0.01). After controlling for potential confounding variables like age, diabetes and smoking status, none of the variables we evaluated were associated with an increased risk of deep infection in Type 1, 2, and 3A open tibia fractures in patients treated with primary wound closure.ConclusionOur findings suggest that in open tibia fractures, which receive timely antibiotic administration, primary wound closure is associated with a decreased infection risk. We recognize that more definitive studies need to be performed to confirm these findings and confirm feasibility of early antibiotic administration, especially in the pre-hospital context.Level of EvidenceLevel III, therapeutic study.     

Arthroscopic training using pig knee joints

Arthroscopy can be a difficult technique for the resident and staff physician to master. Various models have been constructed to allow the training arthroscopist time to perfect the technique. Aside from cadaver knees, there has been only one report of a successful in vivo training model. Sectioned pig knee joints for teaching and practicing arthroscopy satisfy many of the points suggested by others: they are cost effective, easy to use, mount and store, provide a realistic approach, and have comparable structural anatomy to the human knee.     

Ueber das Verhältniss der Phosphorsäure zum Stickstoff im Urin

Ohne Zusammenfassung