Background: Surgical mortality data are collected routinely in high-income countries, yet virtually no low-or middle-income countries have outcome surveillance in place. The aim was prospectively to collect worldwide mortality data following emergency abdominal surgery, comparing findings across countries with a low, middle or high Human Development Index (HDI).Methods: This was a prospective, multicentre, cohort study. Self-selected hospitals performing emergency surgery submitted prespecified data for consecutive patients from at least one 2-week interval during July to December 2014. Postoperative mortality was analysed by hierarchical multivariable logistic regression.

Dear Editor:In the field of envenomations by poisonous animals, the ability of antivenoms to neutralize the lethal effects of venoms is estimated by a biological assay in which mice are inoculated with a range of venom/antivenom concentrations and the survival/death ratio is recorded. A statistical technique (e.g., Probit) is employed to estimate the amount of antivenom that protects 50% of the animals. This quantity is called median effective dose or effective dose 50 (ED 50 ) and is normally expressed in volume units (i.e., mL or μL). The ED 50 is used in an expression for the assessment of the potency (P) of the antivenom, as follows (1, 2): P = (n -1)LD 50 / ED 50 [1]where "LD 50 " is the median lethal dose (mass of venom that kills 50% of mice), and "n" is the number of LD 50 s used in the assay. "P" is the amount of venom, expressed in mass units or number of median lethal doses, that is completely neutralized per unit volume of antivenom (the expression "(n -1) LD 50 " is used instead of the total amount of venom, nLD 50 , because at the endpoint of the neutralization assay, one LD 50 remains unneutralized and causes the death of 50% of mice). However, in the literature, it is very frequent to find that the same term, ED 50 , is utilized to represent

The first step in branched‐chain amino acid (BCAA) catabolism is catalyzed by the two BCAA transferase isoenzymes, cytoplasmic branched‐chain amino acid transferase (BCAT) 1, and mitochondrial BCAT2. Defects in the second step of BCAA catabolism cause maple syrup urine disease (MSUD), a condition which has been far more extensively investigated. Here, we studied the consequences of BCAT2 deficiency, an ultra‐rare condition in humans. We present genetic, clinical, and functional data in five individuals from four different families with homozygous or compound heterozygous BCAT2 mutations which were all detected following abnormal biochemical profile results or familial mutation segregation studies. We demonstrate that BCAT2 deficiency has a recognizable biochemical profile with raised plasma BCAAs and, in contrast with MSUD, low‐normal branched‐chain keto acids (BCKAs) with undetectable l‐allo‐isoleucine. Interestingly, unlike in MSUD, none of the individuals with BCAT2 deficiency developed acute encephalopathy even with exceptionally high BCAA levels. We observed wide‐ranging clinical phenotypes in individuals with BCAT2 deficiency. While one adult was apparently asymptomatic, three individuals had presented with developmental delay and autistic features. We show that the biochemical characteristics of BCAT2 deficiency may be amenable to protein‐restricted diet and that early treatment may improve outcome in affected individuals. BCAT2 deficiency is an inborn error of BCAA catabolism. At present, it is unclear whether developmental delay and autism are parts of the variable phenotypic spectrum of this condition or coincidental. Further studies will be required to explore this.