A systematic review of cross-sectional differences and longitudinal changes to the morphometry of the brain following paediatric traumatic brain injury.

Paediatric traumatic brain injury (pTBI) is a leading cause of disability for children and young adults. Children are a uniquely vulnerable group with the disease process that occurs following a pTBI interacting with the trajectory of normal brain development. Quantitative MRI post-injury has suggested a long-term, neurodegenerative effect of TBI on the morphometry of the brain, in both adult and childhood TBI. Changes to the brain beyond that of anticipated, age-dependant differences may allow us to estimate the state of the brain post-injury and produce clinically relevant predictions for long-term outcome. The current review synthesises the existing literature to assess whether, following pTBI, the morphology of the brain exhibits either i) longitudinal change and/or ii) differences compared to healthy controls and outcomes. The current literature suggests that morphometric differences from controls are apparent cross-sectionally at both acute and late-chronic timepoints post-injury, thus suggesting a non-transient effect of injury. Developmental trajectories of morphometry are altered in TBI groups compared to patients, and it is unlikely that typical maturation overcomes damage post-injury, or even 'catches up' with that of typically-developing peers. However, there is limited evidence for diverted developmental trajectories being associated with cognitive impairment post-injury. The current review also highlights the apparent challenges to the existing literature and potential methods by which these can be addressed.

Infectious bronchitis in laying hens: interference with response to emulsion vaccine by attenuated live vaccine.

Pullet chicks were reared in isolation; all except a control group were variously vaccinated against infectious bronchitis. Individual haemagglutination inhibition (HI) antibody responses were measured from 1 day to 38 weeks old when all birds were challenged with virulent infectious bronchitis virus, and egg production recorded for a further 5 week period. In the controls HI titres remained low until challenge: this caused a loss of 15.1 eggs/hen. In birds injected with oil emulsion killed vaccine (OEV) at 3 and 16 weeks old, the serological response was uniformly high but on challenge the loss in egg production was 2.9 eggs/bird. Birds given H120 live vaccine at 3 weeks and H52 live vaccine at 15 weeks old had a low (23%) individual rate of serological response to the latter, and egg production after challenge was 3.63 eggs/hen less than before. In birds given H120 live vaccine at 3 weeks and emulsion killed vaccine at 16 weeks old, 100% serological response to the latter occurred and egg production was unaffected by challenge. A further group also received H120 and H52 live vaccines at 3 and 15 weeks old respectively: however, they were then subdivided into four groups and injected with emulsion vaccine at either 17, 19, 21 or 23 weeks old. Their response to H52 vaccine was variable. The proportion of birds in each sub-group responding serologically to subsequent vaccination with OEV was 45, 65, 73 and 92% respectively. After challenge egg production in these four sub-groups was reduced by 1.92, 1.15, 0.94 and 1.55 eggs/bird respectively. It is concluded that response to oil emulsion infectious bronchitis vaccine can be impaired if it is used within 8 weeks of H52 live vaccine. Best results are achieved where birds are given a primary dose of H120 live vaccine at 3 weeks old followed by emulsion vaccine 12-16 weeks later. Use of the less attenuated H52 strain of live vaccine before emulsion killed vaccine is contra-indicated.

Comparison of various preparations of nuclear antigens by hemagglutination inhibition (HAI).

A clinical laboratory carrying out tests for antinuclear antibodies requires an efficient, reliable preparation method to produce a high yield of nuclear antigens at low cost and a very sensitive, specific assay method for antigen activity. Various tissues were employed for preparation of small nuclear ribonucleoprotein (snRNP) and Sm antigens for these purposes. Fresh calf thymus cells and nuclei, commercially available calf and rabbit thymus acetone powders, fresh rat kidney and liver cells were used as sources of antigens prepared similarly by methods published previously. Preparations of antigens from whole calf thymus cell extracts were prepared with and without inhibitors to protease and RNase. snRNP and Sm antigens were assayed at each preparation step by hemagglutination inhibition (HAI). Using HAI it was possible to routinely assay snRNP and Sm at nanogram/ml quantities which was 10(6) fold more sensitive than Ouchterlony immunodiffusion. Results were expressed as relative specific activity as compared with calf thymus nuclear extract prepared by conventional methods. Protease and RNase inhibitors did not significantly increase yields. Thymus was the best source of snRNP and Sm. Fresh calf thymus extract produced a good, stable, reliable quantity of antigens, whereas calf and rabbit thymus acetone powders provided antigen at higher specific activity with less labor but slightly lower yields. Thus, considering the total cost of preparations, commercial sources may be superior to fresh sources in the clinical laboratory setting. These studies also revealed the utility of the sensitive HAI test not only in the clinical laboratory but also for further research endeavors.

Apparatus for pasteurising teat cup liners between cows in a herringbone parlour.

In a herringbone milking parlour, teat cup liners were deliberately contaminated in turn with Staphylococcus aureus, Escherichia coli, Streptococcus agalactiae and Sterp uberis. Contamination was achieved by filling the liners with milk that contained 10(6) test organisms per ml. After the clusters had been back-flushed with water at 85 degrees C for five seconds, normal swabbing methods failed to recover any contaminating organisms from the teat liners in 56 tests out of 64. After 10 seconds back-flushing no recoveries were made in the same number of tests. The apparatus developed to effect this back-flushing for a particular herringbone parlour is described, with details of its routine use during milking. For a 100-cow herd, the running cost of such equipment using a five-second back-flush is estimated at no more than 4 pounds per week and, in its present form, would not add more than 10 seconds to the total milking time for each cow. Improvements in design of the apparatus, and in milking techniques arising from the routine use of the device, are also considered.