melatonin suggests that it is well tolerated at the dose used. The present study, however, does not indicate whether it is necessary to take melatonin before and during the flight or only after it. Further research is needed on the dose response characteristics of melatonin to optimise its effect in alleviating jet lag.Overall the results support the use of melatonin for alleviating jet lag and tiredness after long haul flights and indicate further investigations necessary to maximise the positive effects of melatonin.We thank Air New Zealand for its help and support.

No abstract

Eight histopathologists, based at different hospitals, who had previously examined 100 consecutive colposcopic cervical biopsies were circulated with the results of the initial study. The slides were then 'reblinded' and re-examined by the pathologists who, as before, assigned them into one of six diagnostic categories. The degree of interpathologist agreement for the seven observers who returned usable responses was characterized by kappa statistics and compared to the corresponding figures for the same observers from the previous study. Although some of the observers showed significant alterations in their diagnostic practices there was persistent poor agreement for CIN 1 and 2, mediocre agreement for CIN 3 and excellent agreement for invasive carcinoma. Intra-observer agreement was consistently better than inter-observer agreement for each of the diagnostic categories. Significant differences were found among observers in the degree of intra-observer variability. The 20 cases in which there was most disagreement were re-examined by one of the authors who compared these with 20 biopsies which caused little disagreement. Disagreement was considered to be associated with florid papilloma-virus changes, basal cell hyperplasia and severe inflammation in varying combinations. On the basis of these findings we suggest changes in the terminology of CIN lesions.

Cervical smears (n = 150) from five departments showing high-grade dyskaryosis were examined by three cytologists. All the smears came from patients with biopsy-proven CIN III. One hundred had been correctly reported (true positives) but 50 had originally been reported as negative and had been found to be positive only on review (false negatives). There were significant differences between the two sets in the characteristics of the dyskaryotic cell population. The false-negative smears tended to have fewer than 200 dyskaryotic cells. The nuclei of the dyskaryotic cells tended to have fine rather than coarse nuclear chromatin. A smear with fewer than 50 dyskaryotic cells is 26 times more likely to be reported as negative than one with more than 200 dyskaryotic cells. The results suggest that there is a type of severely dyskaryotic smear that is inherently likely to be missed on routine screening.

Aims-To determine the number of unsuspected disease processes found in a series of cases of sudden unexpected death occurring outside hospital and to enumerate how many of these were not recorded on the death certificate. Methods-In a series of 1000 routine coroners' necropsies for sudden unexpected death, major findings that had not been known about in life were recorded. Macroscopic findings were confirmed histologically as appropriate. The deaths occurred either outside hospital or in the Accident and Emergency department before the patient could be examined. Cot deaths and decomposed bodies were excluded. Results-There were 575 major findings in 532 (53.2%) subjects that had been clinically silent in life. Of these 575 findings, 277 (48.2%) were not the cause of death and so did not appear on the death certificate. Eighty per cent of the major alimentary system findings and all of the genitourinary findings were of this type. In addition, however, 30% of the major cardiovascular and 34% of the major respiratory findings were not recorded on the death certificate for this reason. Conclusions-A large amount of important epidemiological data is being lost in the operation of the coronial system. Some of this information is irrecoverable as the function ofthe death certificate is to provide a cause of death only. In addition, information may be being lost because the necropsy is not being performed adequately and is not subject to audit. clinically unsuspected in life in a series of necropsies for sudden death outside hospital. This was partly to see how common such findings were and also to discover how many of these would not appear on the death certificate because they were not considered to be causally related to the death.