Study of isolated apparent amniogenic limb deficiency in Hungary, 1975-1984

Rat brain cortex slices and synaptosomes preincubated with [3H]noradrenaline were used to investigate whether the NMDA-evoked noradrenaline release is modulated by agonists or antagonists at presynaptic alpha 2-adrenoceptors. In experiments on slices, noradrenaline and the preferential alpha-adrenoceptor agonists talipexole (former B-HT 920) and clonidine inhibited the NMDA-evoked tritium overflow whereas the selective alpha 1-adrenoceptor agonists cirazoline and methoxamine were ineffective. The alpha 2-adrenoceptor antagonists rauwolscine and idazoxan facilitated the NMDA-evoked tritium overflow whereas the preferential alpha 1-adrenoceptor antagonist prazosin was ineffective. The concentration-response curve of talipexole for its inhibitory effect on NMDA-evoked overflow was shifted to the right by idazoxan (apparent pA2 = 7.5). The EC50 of NMDA (97 mumol/l) for its stimulating effect on tritium overflow was not substantially changed by blockade of alpha 2-autoreceptors with 1 mumol/l rauwolscine (EC50 of NMDA in the presence of the alpha 2-adrenoceptor antagonist, 155 mumol/l), but the maximal overflow of tritium was increased 2.5 fold by this rauwolscine concentration. In experiments on synaptosomes, talipexole and noradrenaline inhibited the NMDA-evoked tritium overflow. The inhibitory effect of talipexole was abolished by idazoxan which, given alone, was ineffective, as was prazosin. Talipexole did also not produce an inhibition when tritium overflow was evoked by NMDA in the presence of omega-conotoxin GVIA 0.1 mumol/l; the latter, by itself, decreased the response to NMDA by about 55%.(ABSTRACT TRUNCATED AT 250 WORDS)     

Models of high velocity impact phenomena

Models of craters formed by impacts at velocities of up to 24.5 km/sec have been computed using the Smooth Particle Hydrodynamics, MESA, EPIC and CALE codes. These modeling efforts are compared to data obtained from the Hypervelocity Microparticle Impact project at Los Alamos using the van de Graaff accelerator. A factor of 5 increase in yield strength was needed to account for high strain rate effects and to match the data. Structure in the data is addressed by using crater volume instead of crater diameter cubed. Detailed code comparisons were made between the four codes with good agreement found.     

Nontuberculous mycobacteriosis as a complication of the Swyer-James syndrome

The chest radiograph of a 35-year-old man with fatigue, exertional dyspnoea and haemoptyses revealed a cavity in the left upper lobe and a shrunken left lung with radiolucency greater than that on the right. Acid-fast rods in sputum were identified as Mycobacterium kansasii on culture. Scintigraphy showed a 9% residual perfusion on the left and abnormal ventilation, compatible with Swyer-James syndrome. This had favoured the development of a mycobacterial infection. There was also a decrease in ciliary function (rate of 4-7 Hz, normal: 10-11). Treatment, begun when tuberculosis had been suspected, was after sensitivity tests changed to a combination of rifampicin (600 mg), ethambutol (1600 mg) and protionamide (500 mg) daily. There was marked regression of the findings within 4 weeks, but treatment was prematurely stopped after 11 months. Two years later there was a recurrence which again responded well to the same drug regimen with additional sulphamethoxazole (1600 mg/d).     

A micromechanics model for the prediction of static strength of off-axis unidirectional laminates

In this paper a micromechanics model using the concentric cylinder assemblage model and the Mori-Tanaka average stress scheme is used to predict the static strength of unidirectional angle ply laminates. The predicted strengths agree with experimental results for Glass/Epoxy and Graphite/Epoxy systems.