The replication-associated protein (RepA) of Maize streak virus interacts in yeast with retinoblastoma-related protein (RBR), the negative regulator of cell-cycle progression. This may allow ...geminiviruses to subvert cell-cycle control to provide an environment that is suitable for viral DNA replication. To determine the importance of this interaction for MSV infection, the RBR-binding motif, LxCxE, was mutated to IxCxE or LxCxK. Whilst RBR binding in yeast could not be detected for the LxCxK mutant, the IxCxE protein retained limited binding activity. Both mutants were able to replicate in maize cultures and to infect maize plants. However, whereas the wild-type virus invaded mesophyll cells of mature leaves, the LxCxK mutant was restricted to the vasculature, which is invaded prior to leaf maturity. Mature leaves contain high levels of RBR and it is suggested that the MSV RepA-RBR interaction is essential only in tissues with high levels of active RBR.
In animal experiments the oedema in the acute inflammatory response is dependent on both increased blood flow and increased vasopermeability (the two component hypothesis). We have confirmed the ...validity of this hypothesis in man by demonstrating synergistic interaction between PAF-acether (a permeability agent) and prostaglandin E2 (a vasodilator). The mixture of PAF-acether and PGE2 (50 ng; 0.5 micrograms) produced a larger cutaneous wheal volume response than could be accounted for either by summation of the responses to the individual mediators or by the slopes of their dose response curves.
Thirty-nine patients were studied with regard to post-irradiation changes in the chest. Twenty of these were reviewed retrospectively and 19 studied prospectively. All patients had chest radiographs ...and computed tomography (CT) of the chest following radiotherapy. Nineteen also had ventilation and perfusion studies of the lung, including single photon emission computed tomography (SPECT) and these were correlated with the chest radiographs and computed tomography. The majority showed abnormalities on computed tomography, the commonest being areas of lung opacification and evidence of volume loss. Several patients also showed a reduction in the size of pulmonary vessels. In most but not all, the changes were also seen on the chest radiographs. Abnormalities were not confined to the radiation fields, the vascular changes being present in large areas of lung which had not been directly irradiated. The structural and functional abnormalities correlated well as shown by ventilation and perfusion scintigraphy. However, single photon emission computed tomography was more sensitive than planar scintigraphy in showing perfusion defects, and it also showed some defects in areas of lung which appeared normal on computed tomography and the chest film. Computed and photon emission tomography were considerably more sensitive than chest radiography in showing the changes due to irradiation. The chest radiograph is clearly an insensitive indicator of post-irradiation change in the lung. Functional abnormalities are more profound and extensive than the chest film suggests, even when it is positive. There are clear implications for the planning of radiotherapy fields affecting the chest in patients who have good prospects of long-term survival. The maximum damage is related to irradiation of the hilum or mediastinum and this should be avoided wherever possible.
Twelve patients with chronic asthma received either high dose beclomethasone once a day or standard doses of beclomethasone three times a day in a double blind crossover trial to determine whether ...inhalation once a day would be sufficient. With the once a day regimen peak expiratory flow rates fell significantly, symptoms of nocturnal asthma increased, and two patients withdrew from the study because of worsening asthma. Whether control can be achieved with steroids inhaled once a day by simply increasing the total daily dose remains to be seen.
Allergy to gerbils MCGIVERN, D; LONGBOTTOM, J; DAVIES, D
Clinical allergy,
March 1985, Letnik:
15, Številka:
2
Journal Article
Recenzirano
Pet gerbils were identified as the cause of asthma or rhinitis in three out-patients seen over a period of eighteen months. Allergy to gerbils was confirmed by skin tests, RAST and the clinical ...course. Gerbils are popular household pets and allergy to gerbils may be commoner than recognized.
Factors influencing mortality were studied in 92 consecutive cases of infective endocarditis admitted to two district general hospitals between January 1975 and April 1982. Thirty two patients died, ...an overall mortality of 35%, 13 patients died before diagnosis and 19 despite aggressive antimicrobial therapy. Bactericidal antibiotic levels were monitored in 39 cases but these did not appear to influence outcome. Mortality was lowest for Streptococcus viridans infection (15%) but rose to 50% for infections with S. faecalis and other less common organisms. Most deaths were in patients over 50. Cardiac failure on admission was a poor predictor of mortality, although this was the principal cause of death during treatment (14 cases). Eight patients had emergency valve replacement and 3 died post-operatively. When the diagnosis was missed during life (13 cases) arterial embolus was a common presenting feature (46%). Classical signs of endocarditis, other than pyrexia, were absent. A cardiac murmur (always mitral incompetence) was noted in only 6 cases and considered to be insignificant.
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