Mobile retinal screening--a Waikato Area Health Board initiative

In conclusion the Waikato Area Health Board has shown that regular eye review can be offered to all patients with diabetes by means of a register of people with diabetes, and the provision of a mobile retinal screening service. The use of a mydriatic camera is a practical and cost-effective way of providing this service, and with suitably designed carrying systems it can be provided at almost any venue, ensuring access even for people in remote rural areas. Demands for our service have meant that we are now offering retinal screening to other Waikato communities which do not have access to a visiting ophthalmologist.     

Force‐sensitive tactile sensor for minimal access surgery

A new approach to detecting abnormalities in organ tissue, particularly in relation to minimal access surgery, is presented. Prototype sensors, based on piezoresistive material, were developed and assembled into a forceps for evaluation on simulated diseased tissue. Data on the resilience and location of phantom tumours were recorded and displayed visually for ease of interpretation. Both single sensor and multiple sensor arrays (one‐ and two‐dimensional) were manufactured and tested.     

The blood-nerve barrier: enzymes, transporters and receptors--a comparison with the blood-brain barrier

The blood–brain barrier (BBB) has been much more extensively investigated than the blood–nerve barrier (BNB). Nevertheless it is clear that there are both similarities and differences in the molecular and morphophysiological characteristics of the two barrier systems. A number of enzymes, transporters and receptors have been investigated at both the BNB and BBB, as well as in the perineurium of peripheral nerves, which is also a metabolically active diffusion barrier. While there have been few systematic comparisons of the distribution of these molecules in both the BNB and BBB, it is apparent from the data available, reviewed in this article, that their distribution also supports the concept of the BNB and BBB having some features in common but also showing distinct identities. These similarities and differences cannot simply be accounted for by the presence of the inductive influences of astrocytes at the BBB and absence at the BNB. Whether the Schwann cell also has the capacity to induce some BNB properties remains to be determined.     

Cross reactivity of polyclonal GFAP antiserum: implications for the in-vitro characterisation of brain endothelium

Following a recent claim, based on glial acidic fibrillary protein (GFAP) expression, that brain-derived astrocytes in culture are in fact endothelial cells, we immuno-labelled primary cultures of rat brain astrocytes and endothelium with various GFAP antisera. Both cell types stained positively with a polyclonal antibody, although monoclonal antiserum labelled only astrocytes. We conclude that staining of endothelial cells with the polyclonal GFAP antiserum is due to cross reactivity with another protein.     

Venous thromboembolism in pregnancy and the puerperium: incidence and additional risk factors from a London perinatal database

Objective To determine the incidence of venous thromboembolism in pregnancy and the puerperium and to identify risk factors for pregnancy-related venous thromboembolism.
Design Cohort study and case–control study.
Setting London, UK.
Population 395,335 women with live births or pregnancies of 24 or more weeks of gestation between 1988 and 1997.
Methods Data extraction from the St Mary's Maternity Information System database. Random sample of 5% for case–control study.
Main outcome measures Incidence of venous thromboembolism; odds ratios for variables associated with venous thromboembolism.
Results The incidence of venous thromboembolism was 85/100,000 maternities. There were approximately twice as many postpartum as antepartum events. Blood group A, multiple pregnancy, caesarean section, cardiac disease, delivery at gestational age of <36 weeks, a body mass index of ≥25, or more and maternal age of 35 or over were all found to increase incidence of venous thromboembolism.
Conclusions Although venous thromboembolism is the leading cause of maternal deaths in the UK, it is still a rare event. Most of these events are deep vein thromboses occurring in the postpartum period. Antenatally multiple birth is an important risk factor. Postnatally women who have had a caesarean section, premature delivery or history of cardiac disease should be assessed carefully for venous thromboembolism.     

Clinical information for research; the use of general practice databases.

General practice computers have been widely used in the United Kingdom for the last 10 years and there are over 30 different systems currently available. The commercially available databases are based on two of the most widely used systems--VAMP Medical and Meditel. These databases provide both longitudinal and cross-sectional data on between 1.8 and 4 million patients. Despite their availability only limited use has been made of them for epidemiological and health service research purposes. They are a unique source of population-based information and deserve to be better recognized. The advantages of general practice databases include the fact that they are population based with excellent prescribing data linked to diagnosis, age and gender. The problems are that their primary purpose is patient care and the database population is constantly changing, as well as the usual problems of bias and confounding that occur in any observational studies. The barriers to the use of general practice databases include the cost of access, the size of the databases and that they are not structured in a way that easily allows analysis. Proper utilization of these databases requires powerful computers, staff proficient in writing computer programs to facilitate analysis and epidemiologists skilled in their use. If these structural problems are overcome then the databases are an invaluable source of data for epidemiological studies.     

Current practice of neonatal circumcision in the Waikato

A survey of babies born in the Waikato revealed an incidence of neonatal circumcision of 7% in the first month. General practitioners performed 58% of these. About half were carried out before the baby left the maternity unit. Waikato maternity units had a wide variation in the rate of circumcision from 0-15%. Twenty percent of general practitioners offer neonatal circumcision as part of their services. Sixty-one percent of general practitioners said they try and dissuade parents from the practice. Also in replying to the questionnaire, of the 27 general practitioners who offered circumcision as part of their practice, six (22%) said they performed more than five circumcisions a year and 25% said they used a local anaesthetic.     

Venous thromboembolic disease and combined oral contraceptives: A re-analysis of the MediPlus database.

In October 1995 the Committee on Safety of Medicines advised UK doctors and pharmacists that oral contraceptives containing desogestrel and gestodene were associated with double the risk of venous thromboembolic events (VTE) compared to pills containing other progestogens. In 1997 data was analysed from the MediPlus database of UK general practitioner records, which reported odds ratios for desogestrel and gestodene lower than that for levonorgestrel. Here the results of a more stringent nested case control analysis on the MediPlus database are reported. The study was larger and cases were verified. A crude incidence of idiopathic VTE was found amongst users of combined oral contraceptives of 4.6 per 10 000 exposed women years. Using levonorgestrel 150 microg + ethinyloestradiol 30 microg as reference, non-significant odds ratios of 1.1 (0.5-2.6) for desogestrel 150 microg + ethinyloestradiol 30 microg and 1.1 (0.5-2.4) for gestodene 75 microg + ethinyloestradiol 30 microg were found. The results of this study show no significant difference in risk between different formulations of combined oral contraceptive.