Bovine aortic arch: a novel association with thoracic aortic dilation.

AIM: To investigate whether there is a link between bovine arch and thoracic aortic aneurysm. MATERIALS AND METHODS: Computed tomography (CT) and magnetic resonance imaging (MRI) images of the thorax of 191 patients with dilated thoracic aortas and 391 consecutive, unselected patients as controls were retrospectively reviewed. Bovine arch was considered present if either a shared origin of the left common carotid and innominate arteries or an origin of the left common carotid from the innominate artery was identified. A chi-square test was used to evaluate the significance of differences between subgroups. RESULTS: A trend towards increased prevalence of bovine arch was seen in patients with dilated aortas (26.2%) compared to controls (20.5%, p=0.12). The association was statistically significant in patients over 70 years old (31.9%, p=0.019) and when dilation involved the aortic arch (47.6%, p=0.003). CONCLUSIONS: An association between bovine arch and aortic dilation is seen in older patients, and when dilation involves the aortic arch. Bovine arch should be considered a potential risk factor for thoracic aortic aneurysm.

A portable system for closed loop control of the paralysed hand using functional electrical stimulation.

A portable and closed-loop system is described for the paralysed hand using transcutaneous electrical stimulation. It is implemented using a modest microprocessor which receives data from force sensors mounted in a glove on the users hand. A display shows parameter values and a menu for the user to sequentially select controller states. For the grip state, the control loop is basically proportional plus a two stage integral response (gain adaptation). Eight channels can be accommodated in the stimulator. The system was evaluated with the help of a tetraplegic who managed to hold everyday objects in a stable grip.

The effect of permethrin-impregnated wall-curtains on malaria transmission and morbidity in the suburbs of Maputo, Mozambique.

The effect of nylon-netting wall-curtains impregnated with 0.5 g permethrin/m2 upon the biting rate of malaria vectors (Anopheles gambiae s.l. and An. funestus) and on the Plasmodium falciparum parasite rate, and morbidity due to malaria in children under five and between five and fourteen years was tested in the Maputo area. The curtains significantly lowered biting rates of both vector species inside curtained houses, but reduced inside resting and outside biting only in An. funestus. The percentage of children with falciparum parasitaemia fell significantly in curtained houses, and among their neighbours. However, parasite load and malaria morbidity in under fives was unaffected but malaria morbidity fell throughout the experimental area in 5 to 14-year-olds. This led to the speculation that malaria vectors inhibited from feeding in the vicinity of the curtains might have gone to feed in the adjacent control area.

Worms, wells and water in western Madagascar.

This study of schistosomiasis and intestinal parasites was carried out on 496 children in the Firaisana (District) of Ankilivalo in Western Madagascar. The prevalence of these parasites was determined and data collected on nutrition, agriculture and the use of water in order to gain an understanding of the transmission and effects of these parasites. Recommendations for their control are suggested. In two schools within the area of a major irrigation scheme the prevalence of urinary schistosomiasis was 69%, and 50% suffer from at least one intestinal worm. In a school outside the main irrigation area, the prevalence of schistosomiasis was much lower (7%). Ultimately the control of schistosomiasis will depend on improvements to the irrigation and drainage infrastructure, and in standards of sanitation. However, chemotherapy is the only method of bringing the disease under control in the short term.

Practical low cost stand/sit system for mid-thoracic paraplegics.

The use of functional electrical stimulation (FES) to enable paraplegics to stand is not new or indeed difficult to undertake under laboratory conditions. However, there are substantial problems to overcome before such systems can be used routinely by patients without professional supervision. The overriding consideration has to be one of safety, i.e. the system must be 'fail safe'. Secondly, the system must be quick and easy to use in a wide variety of locations, otherwise it will not provide any increase in function. Finally, it must be inexpensive enough to be available to a large number of paraplegics. The primary aim of our work was to provide such a system to enable mid-thoracic lesion paraplegics to stand wherever they wish. This involved the development of a microprocessor-based stimulator to enable the stimulating envelope to be individually tailored to a given patient's requirements and the provision of closed loop control to minimize fatigue. A folding standing frame was also designed which replaces the arm rests on a standard wheelchair. Using this system, the user is able to stand within 30 s of stopping and can remain standing for up to 10 min. Cosmetic calipers (knee-ankle-foot orthoses) are also being used for paraplegics who require to stand for longer periods. It is hoped that such a system will provide stable standing for a large number of paraplegics at a unit cost of approximately 750 pound.