Summary Expressed prostatic secretion (EPS) was obtained both from the uninflamed human prostate and from cases of acute and subacute prostatitis in the course of routine clinical examination. In addition to microscopy and bacteriological examination, the pH of this fluid was tested using both Camlab Duotest pH papers (Camlab Ltd, Cambridge) and a Radiometer pH Micro‐electrode. Specimens of EPS from the normal gland were found to have a mean pH of 6.6 and were therefore similar in this respect to normal canine prostatic fluid. In a series of specimens from cases of prostatitis, there was a variable increase in pH, the mean being 7.7. The implications of this finding are briefly discussed in relationship to the concentration of antibacterial agents within the prostatic acini and ducts and their biological activity. Part of the work of this project was assisted by a grant from Schering Chemicals Ltd, England.

1 Lincomycin (600 mg) was given 6 h preoperatively by intramuscular injection, as an intravenous infusion over 30 min and for 72 h postoperatively in twelve patients having total hip replacement. 2 The plasma, bone, hip capsule, synovial and drain fluid concentrations of lincomycin were almost always above the M.I.C. of lincomycin against penicillinase producing Staphylococcus aureus. 3 There was a good correlation between the estimated concentrations of lincomycin in bone by the grinding and agitation methods of analysis. 4 Two patients developed pseudomembranous colitis after parenteral lincomycin.

During a 19-month study the incidence of diarrhoea and colitis was estimated in 1158 orthopaedic inpatients admitted to the Guy's group of hospitals. The highest incidence of diarrhoea followed the use of lincomycin (22.2 per cent), ampicillin with cloxacillin (17.2 per cent), clindamycin (15.3 per cent) and combined therapy with cloxacillin and tetracycline (12.5 per cent). There were 3 documented cases of colitis; 2 followed lincomycin and 1 clindamycin. The incidence and relationship of antibiotic-related diarrhoea and colitis to possible aetiological factors are discussed. In orthopaedic inpatients, in whom lincomycin and clindamycin are often the antibiotics of choice, their continued use appears to be fully justified by the low incidence of colitis. However, if a patient receiving treatment with either of these antibiotics does develop diarrhoea, the antibiotic should be discontinued immediately, to reduce the risk of subsequent colitis.

The use of d-dimer tests for the exclusion of venous thromboembolism is an important advance in clinical practice and also has economic benefits. The Stalia D-Di (Diagnostica Stago, Asnieres, France) is a semi automated system for the quantification of d-dimer using an immuno-turbidometric method incorporating a suspension of latex microparticles coated with two different monoclonal antibodies specifically targeted against human d-dimer fragments. Results are available rapidly in <10 min compared with 35 min for the established VIDAS D-dimer automated enzyme-linked immunosorbent assay (ELISA, BioMerieux, Basingstoke, UK). During November and December 2005, 100 consecutive patients attending the outpatient deep venous thrombosis (DVT) clinic were tested using the VIDAS D-dimer as part of the routine DVT investigation. Using the same samples, D-dimer estimation was also performed on the STalia D-Di for comparison. Across a wide range of data (Vidas 83-5656) and (STali <200->4000), there was good agreement between the two methods. Using cutoff's of 500 microg/l fibrinogen equivalent units (Keeling et al., 1999), 42% (42/100) patients were negative (<500) and 46% (46/100) were positive (>500) on both systems. Six per cent (6/100) were positive on the Vidas but negative on the STalia and another 6% (6/100) were positive on the STalia but negative on the Vidas. In conclusion, 88% (88/100) of patients showed agreement and in the other 12% (12/100), one had a DVT as identified by Compression ultrasonography (CUS). In this study, there were seven patients with a DVT as identified by CUS and they all scored as 'likely' on a pretest clinical probability score and so negative D-dimer would not be used clinically to rule out the disease. The Vidas is a well established instrument for D-dimer measurement in outpatient DVT clinics, and in this small study the STalia compares very well and therefore would fit into an outpatient setting for D-dimer measurement. But ideally a larger study would be required before implementing new methodology in a clinical setting.