There has been considerable controversy regarding the safety of topical chloramphenicol in ophthalmic practice. The evidence for associated haematopoietic toxicity in idiosyncratic and dose-dependent forms was reviewed. The 7 cases of idiosyncratic haematopoietic reactions associated with topical chloramphenicol reported in the literature are refutable evidence for the existence of such a response. In Scotland, despite extensive prescription of topical chloramphenicol, the incidence of acquired aplastic anaemia was found to be low, as were associated reports of blood dyscrasias throughout the UK. The epidemiology of acquired aplastic anaemia failed to make an association with topical chloramphenicol use. High-performance liquid chromatography (minimum detection limit 1 mg/l) was used to investigate whether serum accumulation of chloramphenicol occurred after topical therapy in 40 patients. The mean dose of chloramphenicol eye drops used after 1 week of treatment was 8.0 mg, and after 2 weeks, 15.3 mg. As expected, chloramphenicol failed to accumulate to detectable levels. This supported the view that topical chloramphenicol was not a risk factor for inducing dose-related bone marrow toxicity. Calls for the abolition of treatment with topical chloramphenicol based on current data are not supported.

Absorption of sulfated and nonsulfated chenodeoxycholic and glycochenodeoxycholic acid was studied in the colon and the data were compared with the absorption rates in the ileum. Absorption of nonsulfated chenodeoxycholic acid in the colon was in the same range of magnitude as in the ileum. Glycochenodeoxycholic acid absorption in the colon was lower than in the terminal ileum. Sulfated bile acids were not absorbed in the colon. In the ileum, absorption of sulfated bile acids was significantly (p < 0.01) lower than the absorption of nonsulfated bile acids. Little absorption of sulfated bile acids in the ileum and lack of absorption in the colon both contribute to the rapid turnover and excretion of bile acid sulfates.

Background and AimsIn human adults, and animals, the Apelin-APJ ligand-receptor system is emerging as having a role in the pathogenesis of cardiovascular function and heart failure. The aim was to investigate expression, and regulation by oxygen, of the Apelin APJ receptor (APJ) in myocardium obtained from children undergoing corrective surgery with cardiopulmonary bypass for repair of congenital heart defects.MethodsWestern blotting and Real-time PCR were used to determine if APJ was expressed in the infant myocardium, if expression was influenced by the duration of myocardial ischemia and if any relationship existed between APJ expression and early post-operative outcome. The next aim was to determine if there was a difference in mRNA expression of APJ in myocardium from cyanotic patients compared with acyanotic patients and if re-perfusing myocardium in vitro with either hypoxic, normoxic or hyperoxic oxygen affected APJ mRNA expression.ResultsAPJ was expressed in all myocardial samples and myocardium exposed to longer durations of ischemia and cardioplegia expressed higher levels of APJ (p<0.05). There was a significant correlation between APJ expression in myocardium resected after 10 min with both oxygen extraction ratio (p = 0.021, rho = −0.523) and mixed venous oxygen saturation (p = 0.028, rho 0.52). This association did not exist for myocardium collected before 10 min. There was no difference in APJ expression between cyanotic and acyanotic patients. No difference was found in APJ expression whether re-perfused with low, normal or high oxygen.ConclusionsChanges in APJ expression were observed during cardiopulmonary bypass in children and the reasons for this require further investigation.

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