PubMed · 6692690
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W O Harrison. 1984. Gonorrhea.. https://pubmed.ncbi.nlm.nih.gov/6692690/
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OBJECTIVE: The aim of this study is to investigate the therapeutic role of vitamin A in addition to standard antibiotic treatment on healing of experimental acute maxillary sinusitis. MATERIAL AND METHODS: Experimental maxillary sinusitis in rabbits was induced by blocking the left noses and direct inoculation of Staphylococcus aureus into the left maxillary sinuse cavities. Right maxillary sinuses were exposed to serum physiologic as the control group. Animals were divided into two groups. Forty-eight hours after the inoculation, Group A received only parenteral ampicilline-sulbactam (50 mg/kg), Group B were treated with same antibiotic regimen and parenteral a dose of 100.000 IU vitamin A in palmitate form. Animals were killed at 10th day and mucosas of each sinuses were examined histopathologically. Inflammation and sinus epithelium integrity were assessed. Groups were compared with using Mann-Whitney U test. RESULTS: All of the infected sinuses displayed various degrees of inflammation but there was no statistically significant difference between the study and control groups. Although epithelium integrity was slightly better in Group B but the difference was not meaningful. CONCLUSION: The adjuctive therapeutic role of vitamin A in acute sinusitis was found doubtful but this topic is worth to investigate more comprehensively.
We report what is, to our knowledge, the first in vitro selection for catalytic activity based on catalytic turnover by using ribosome display, a method which does not involve living cells at any step. RTEM-beta-lactamase was functionally displayed on ribosomes as a complex with its encoding mRNA. We designed and synthesized a mechanism-based inhibitor of beta-lactamase, biotinylated ampicillin sulfone, appropriate for selection of catalytic activity of the ribosome-displayed beta-lactamase. This derivative of ampicillin inactivated beta-lactamase in a specific and irreversible manner. Under appropriate selection conditions, active RTEM-beta-lactamase was enriched relative to an inactive point mutant over 100-fold per ribosome display selection cycle. Selection for binding, carried out with beta-lactamase inhibitory protein (BLIP), gave results similar to selection with the suicide inhibitor, indicating that ribosome display is similarly efficient in catalytic activity and affinity selections. In the future, the capacity to select directly for enzymatic activity using an entirely in vitro process may allow for a significant increase in the explorable sequence space relative to existing strategies.
A kinetic study on decomposition processes of some penicillin salts was carried out. Both isothermal and dynamic thermogravimetric curves were used. As expected by their complex structures, several steps with different energies were involved in decomposition processes. Model-fitting and -free kinetic approaches were applied to nonisothermal and isothermal data. The kinetic triplet (f(alpha),A and E(a)) related to model-fitting method that defines a single step reaction resulted to be at variance with the multi-step nature of salts-decomposition. The model-free approach represented by the isothermal and nonisothermal isoconversional methods, gave different dependencies of the activation energy on the extent of conversion. The complex nature of the multi-step process of the studied compounds was more easily revealed using a broader temperature range in nonisothermal isoconversional method. The failure in the model-fitting method did not allow calculating shelf life and half-life times.