Rheological characterisation of dextran-concanavalin A mixtures as a basis for a self-regulated drug delivery device.

The rheological characterisation of glucose sensitive mixtures containing dextran and concanavalin A (con A) with and without glucose, was undertaken using oscillatory rheometry at 20 and 37 degrees C so that comparative data could be gathered in the linear viscoelastic (LVE) range. Measurements for a series of mixtures showed that complex viscosity is a function not only of the con A concentration but of the content and molecular weight of the dextran used. The extent of liquefaction on addition of glucose also depended on these factors. The tan delta profiles confirmed the change from semi-solid towards fluid behaviour. This occurs when glucose effects dismantling of the three-dimensional structure of the dextran-con A system by competitive binding to the glucose receptors in the protein. For the mixtures studied, the changes occurred between contents of 0 and 1% (w/w) glucose at 20 and 37 degrees C and form a useful basis for the formulation of a self-regulating delivery device for the control of hyper-and hypoglycaemia in diabetes.     

Early treatment of juvenile xanthogranuloma of the iris with subconjunctival steroids.

Five infants with biopsy proved juvenile xanthogranuloma of the iris were reviewed. Early treatment with subconjunctival injection of steroids and topical steroid drops resulted in regression of the lesion in four patients. One patient, reviewed at the age of 8 months after glaucoma which had developed secondary to the iris xanthogranuloma, had been treated by surgery alone: the visual outcome was very poor.     

Hybridization of Aedes (protomacleaya) zoosophus with Ae. (Pro.) triseriatus group species: hybrid morphology

Morphology of hybrids between Aedes (Protomacleaya) zoosophus and Ae. (Pro.) triseriatus group species is described. Adult females of hybrids key to Ae. zoosophus. Hybrids are differentiated from Ae. zoosophus by the dark longitudinal medial or submedial lines on the thorax and by the reduced width of the light tarsal and abdominal bands. The transverse band of light scales on the anterior scutum is complete in Ae. hendersoni/Ae. zoosophus hybrids and incomplete in Ae. triseriatus/Ae. zoosophus hybrids. Aedes brelandi/Ae. zoosophus hybrids are similar to Ae. hendersoni/Ae. zoosophus hybrids. However, due to the allopatric distributions of Ae. brelandi and Ae. zoosophus, such hybrids are not expected.     

How are nations trying to prevent suicide? An analysis of national suicide prevention strategies

Recent increases in suicide rates internationally have focused attention on suicide as an important area of public health concern. In this review, strategies developed by various countries to halt this trend are compared. Nine out of 15 countries respond to enquiry about the state of development of suicide prevention strategies and programmes. Comprehensive strategies have been or are being developed by Finland, Norway, Australia, New Zealand and Sweden. The organization of these strategies differs between countries. The interventions have similar targets and are presented in detail. There are some similarities in strategy content but evident differences in organization. Further developments should not only be based on research, but also consider the diverse experiences of other countries, and they should incorporate appropriate structures for monitoring and evaluation.     

Radiotherapy in the treatment of low-grade astrocytomas

Between 1954 and 1986 inclusive, 160 children in the North West Region of England were registered with histologically proven lowgrade astrocytomas (grade 1 or 2). Ten died before receiving any treatment, and a further seven died within 28 days of surgery, leaving 143 children whose survival in relation to treatment modality is the subject of this paper. Low-grade astrocytomas are responsive to radiation therapy. This treatment has no clear benefit to offer children with superficial tumours that can be resected completely or nearly so, but significantly improves survival rates when tumours are deep-seated and not amenable to excision.     

Expression of collagen and elastic fibers in duct-ligated submandibular glands of mice

Atrophy of salivary glands may occur by ductal obstruction caused by calculus, infection or neoplastic processes, or as consequence of systemic diseases and aging. In the present work, we have used histochemical methods to study the expression of elastic and collagen fibers during experimental atrophy of the submandibular gland of mice. Glandular atrophy was accompanied by a rapid increase in collagen deposition in both septal and intralobular regions. The expression of elastic fibers was not significantly altered during atrophy; a discrete increase of elastic fibers was noted only around ductal structures. The results showed that experimental ductal obstruction is a useful in vivo model to study molecular events that take part in the remodeling of the extracellular matrix during atrophy of salivary glands.     

Axial rotation in the lumbar spine and gaping of the zygapophyseal joints

Axial rotation and zygapophyseal joint gaping was studied using 12 human lumbar spines from individuals ranging in age from 14 to 75 years. Using weight and pulley tests and manipulative testing in a torque apparatus, the movement produced by twisting the spine was found not to be pure axial rotation, but rather movement coupled with various combinations of lateral bending and flexion or extension. This motion may not be possible in testing an individual mobile segment. The twisting movements of the spine do not normally produce gaping of the zygapophyseal joints. These joints adapt to the axial rotation by the compliance of their articular cartilages and the movement of fat pads in and out of the joint capsule. Hypermobility appears to be associated with evidence of damage to part of the mobile segment, suggesting that the hypermobility (gaping) at a joint could be due to instability caused by injury.