The Oxford Optical Pointer: a direction-sensing device with proportional electrical output

For some disabled people pointing provides a more convenient means of communication and control than the use of switches. The quadriplegic who retains good control of head movement can be provided with a number of input alternatives, but no existing system meets all the requirements of a general-purpose electronic pointing device. Consequently the Oxford Optical Pointer has been developed. The principle by which it converts relative direction into analogue electrical signals is described and its application as a head-mounted device for controlling an electric wheelchair is presented.     

Safest birth attendants: recent Dutch evidence.

Analysis of national perinatal statistics from Holland, 1986, demonstrates that for all births after 32 weeks' gestation mortality is much lower under the non-interventionist care of midwives than under the interventionist management of obstetricians at all levels of predicted risk. This finding confirms with great authority the conclusions of all earlier impartial analyses from Britain and other countries which agree in contradicting the claims on which the organisation of maternity services in most developed countries is now based, namely, that childbirth is made so much safer by the application of high technology that only this option should be provided.     

Follicular dendritic cells (FDC) in retroviral infection: host/pathogen perspectives

Summary: Follicular dendritic cells (FDC) are found in the follicles of virtually all secondary lymphoid tissues. In health, these cells trap and retain antigens (Ag) in the form of immune complexes and preserve them for months in their native conformation. FDC thus serve as a long-term repository of extracellular Ag important for induction and maintenance of memory responses. In retroviral infection. FDC trap and retain large numbers of retroviral particles with profound effects on FDC. FDC-trapped retrovirus induces follicular hyperplasia, and conventional Ag trapped prior to infection are lost and new Ag cannot be trapped. Concomitantly, antibody-forming cells (AFC) specific for Ag lost from FDC decrease follow I by loss of specific serum antibody (Ab). Eventually, FDC die and follicular lysis occurs. From the pathogen perspective, binding to FDC is remarkably beneficial, bringing together virus and activated target cells that are highly susceptible to infection. Furthermore, FDC permit HIV to infect surrounding cells even in the presence of a vast excess of neutralizing Ab. Preliminary data suggest that FDC maintain virus infectivity - even when the virus cannot replicate. Thus retrovirus infection monopolizes FDC networks, thereby transforming the FDC Ag repository into a highly infectious retroviral reservoir.     

Place of birth and perinatal mortality

Analyses of the published results of national surveys and specific studies, as well as of the official stillbirth statistics, consistently point to the conclusion that perinatal mortality is significantly higher in consultant obstetric hospitals than in general practitioner maternity units or at home, even after allowance has been made for the greater proportion of births in hospital at high pre-delivery risk. Unpubliched results of the British births 1970 survey, which have now become available, make possible a direct and authoritative analysis of data on the safest place of birth. Not only does this make the earlier conclusion more certain, but it confounds the doctrine that obstetric intranatal care is particularly beneficial for high pre-delivery risk births. There is no evidence from recent years that the findings of 1970 are not equally valid in the 1980s.