Medical Research Council of South Africa.

Background Maternal and neonatal mortality is high in Africa, but few large, prospective studies have been done to investigate the risk factors associated with these poor maternal and neonatal outcomes. Methods A 7-day, international, prospective, observational cohort study was done in patients having caesarean delivery in 183 hospitals across 22 countries in Africa. The inclusion criteria were all consecutive patients (aged ≥18 years) admitted to participating centres having elective and non-elective caesarean delivery during the 7-day study cohort period. To ensure a representative sample, each hospital had to provide data for 90% of the eligible patients during the recruitment week. The primary outcome was in-hospital maternal mortality and complications, which were assessed by local investigators. The study was registered on the South African National Health Research Database, number KZ_2015RP7_22, and on ClinicalTrials.gov, number NCT03044899. Findings Between February, 2016, and May, 2016, 3792 patients were recruited from hospitals across Africa. 3685 were included in the postoperative complications analysis (107 missing data) and 3684 were included in the maternal mortality analysis (108 missing data). These hospitals had a combined number of specialist surgeons, obstetricians, and anaesthetists totalling 0•7 per 100 000 population (IQR 0•2-2•0). Maternal mortality was 20 (0•5%) of 3684 patients (95% CI 0•3-0•8). Complications occurred in 633 (17•4%) of 3636 mothers (16•2-18•6), which were predominantly severe intraoperative and postoperative bleeding (136 [3•8%] of 3612 mothers). Maternal mortality was independently associated with a preoperative presentation of placenta praevia, placental abruption, ruptured uterus, antepartum haemorrhage (odds ratio 4•47 [95% CI 1•46-13•65]), and perioperative severe obstetric haemorrhage (5•87 [1•99-17•34]) or anaesthesia complications (11•47 (1•20-109•20]). Neonatal mortality was 153 (4•4%) of 3506 infants (95% CI 3•7-5•0). Interpretation Maternal mortality after caesarean delivery in Africa is 50 times higher than that of high-income countries and is driven by peripartum haemorrhage and anaesthesia complications. Neonatal mortality is double the global average. Early identification and appropriate management of mothers at risk of peripartum haemorrhage might improve maternal and neonatal outcomes in Africa.

Patients exposed to a surgical safety checklist experience better postoperative outcomes, but this could simply reflect wider quality of care in hospitals where checklist use is routine.

1. Some of the products excreted by cultures of lysine-requiring Escherichia coli A.T.C.C. 12408 grown under lysine-limiting conditions have been studied. 2. A glycolipid designated ;extracellular lipoglycopeptide' was prepared from culture filtrates of such organisms. It contained 35% of lipid, 19% of carbohydrate, 3.4% of P and 3.7% of N. 3. Comparison of the lipids, fatty acids, carbohydrates and amino acids of this lipoglycopeptide with those of whole cells, cell walls and cellular lipopolysaccharides shows that it has few features (except its residual lipids) in common with any of these fractions. 4. The lipoglycopeptide was antigenically related to both walls and lipopolysaccharide.

The cytoplasmic membrane of Bacillus subtilis 168, prepared from cells in the stationary Analyses of the membrane lipid revealed the presence of phospholipids (75OiO), neutral lipid and a compound identified as a diglucosyl diglyceride. The major phospholipids were diphosphatidyl glycerol and phosphatidyl ethanolamine, with small amounts of phosphatidyl glycerol and lipoamino acids.Branched chain fatty acids comprised over 7501, of the total fatty acids of both whole cells and membranes. Is0 and anteiso acids with 15 and 17 carbon atoms were the major components, together with small amounts of is0 acids containing 14 and 16 carbon atoms and n-acids. No unsaturated acids were present. phase, has been found to contain protein (62O/,), RNA (22O/,) and lipid (160/0). [4,5] take place a t the membrane.Although the cytoplasmic membrane holds a central position in bacterial metabolism, the detailed composition of the membrane has been studied in relatively few species. Whilst protein and lipid are apparently ubiquitous constituents of the membrane, the amount of RNA and carbohydrate present has been found to vary widely. Many of these variations can no doubt be ascribed to differences in species and culture conditions, but the lack of uniformity in the analyses makes it desirable that further information be obtained.In order to provide a basis for a detailed investigation of membrane structure in Bacillus subtilis, the chemical composition of the membrane has been determined. MATERIALS AND METHODS Organism and Growth ConditionsBacillus subtilis strain 168 was used throughout. Cells were grown in a medium containing (per litre), NH4C1, 2 g ; K,HPO,, 14 g ; KH,PO,, 6 g ; Na citrate 2 H,O, 1 g; Difco casamino acids, 10 g; pH, 7.6. After autoclaving, MgSO,, 0.2 g and glucose, 5 g were added together with trace metals. An overnight Extraction of the casamino acids used in the culture medium by refluxing with chloroform showed that the fatty acid content was less than 0.5 mg per 100 g of casamino acids. Preparation of Protoplasts and MembranesThe cells were suspended in 0.2 M phosphate buffer pH 6.6 containing 0.25 M sucrose, a t a concentration of 1-2 x loll cells/ml. 1.3 mg of lysozyme and 2 pg of pancreatic DNAase were added per ml of suspension and the cells incubated at 30" for 30 to 60 min until microscopic examination showed > 9Q0/, protoplast formation. The protoplasts were collected by centrifugation (40,000 x g for 50 min) and ruptured by resuspension in distilled water containing mM Mg++ and DNAase (1 pg/ml). The mixture was incubated at room temperature until the viscosity decreased to a level where the solution could be readily pipetted. The membranes were collected by centrifugation (48,000 x g for 30 min), washed five times with 0.Qo/, (w/v) NaCl and stored frozen a t Reagents Lysozyme was obtained from the Sigma Chemical Company and DNAase from Worthington Biochemical Corporation. Analytical grade solvents were used as purchased, all other solvents were redistilled before use.-15".

Gymnodinoid dinoflagellate symbionts, commonly referred to as zooxanthellae, are widely distributed among marine invertebrates. It has been assumed that they represent only one species,Gymnodinium microadriaticum. The fatty acid composition of total lipids and galactolipids of zooxanthellae isolated from 8 species of corals, 3 species of clams and a foraminiferan have been analyzed and found to vary according to the host. For example, the content of eicosapentaenoic acid in clam zooxanthellae monogalactosyldiacylglycerol was less than 2%, whereas in the same lipid from coral zooxanthellae, the content ranged from 9 to 22%. Corresponding values for the acid in digalactosyl-diacylglycerol were 1-8% from clam zooxanthellae and 23-40% from coral zooxanthellae. Coral zooxanthellae monogalactosyldiacylglycerol contain higher levels of octadecatetraenoic acid than are found in digalactosyldiacylglycerol, whereas the reverse is true in clam zooxanthellae. The fatty acid composition of the lipids of an axenic culture of zooxanthellae isolated from the clamTridacna maxima are similar to those of cells freshly isolated from the host. The results suggest either that the host is capable of affecting the fatty acid metabolism of the symbiont or that different strains of zooxanthellae occur in corals and clams.

Prognostic study, level III.

Post-spinal hypotension remains a common and clinically-important problem during caesarean section, and accurate pre-operative prediction of this complication might enhance clinical management. We conducted a prospective, single-centre, observational study of heart rate variability in 102 patients undergoing elective caesarean section in a South African regional hospital. We performed Holter recording for ≥ 5 min in the hour preceding spinal anaesthesia. The low-frequency/high-frequency ratio component of heart rate variability was compared, using a logistic regression model, with baseline heart rate and body mass index (BMI) as a predictor of hypotension (defined as systolic arterial pressure < 90 mmHg) occurring from the time of spinal insertion until 15 min after delivery of the baby. We also assessed clinically relevant cut-point estimations for low-frequency/high-frequency ratio. Low-frequency/high-frequency ratio predicted hypotension (p = 0.046; OR 1.478, 95%CI 1.008-1.014), with an optimal cut-point estimation of 2.0; this threshold predicted hypotension better than previously determined thresholds (p = 0.003; c-statistic 0.645). Baseline heart rate (p = 0.20; OR 1.022, 95%CI 0.988-1.057) and BMI (p = 0.60; OR 1.017, 95%CI 0.954-1.085) did not predict hypotension. Heart rate variability analysis is a potentially useful clinical tool for the prediction of hypotension. Future studies should consider a low-frequency/high-frequency ratio threshold of 2.0 for prospective validation.