Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:5.99.1.2 (topoisomerase)
 9,166 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Streptococcus pneumoniae has been recognised as a major cause of pneumonia since the time of Sir William Osler. Drug-resistant S. pneumoniae (DRSP), which have gradually become resistant to penicillins as well as more recently developed macrolides and fluoroquinolones, have emerged as a consequence of indiscriminate use of antibacterials coupled with the ability of the pneumococcus to adapt to a changing antibacterial milieu. Pneumococci use cell wall choline components to bind platelet-activating factor receptors, colonise mucosal surfaces and evade innate immune defenses. Numerous virulence factors that include hyaluronidase, neuraminidase, iron-binding proteins, pneumolysin and autolysin then facilitate cytolysis of host cells and allow tissue invasion and bloodstream dissemination. Changes in pneumococcal cell wall penicillin-binding proteins account for resistance to penicillins, mutations in the ermB gene cause high-level macrolide resistance and mutations in topoisomerase IV genes coupled with GyrA gene mutations alter DNA gyrase and lead to high-level fluoroquinolone resistance. Risk factors for lower respiratory tract infections in the elderly include age-associated changes in oral clearance, mucociliary clearance and immune function. Other risks for developing pneumonia include poor nutrition, hypoalbuminaemia, bedridden status, aspiration, recent viral infection, the presence of chronic organ dysfunction syndromes including parenchymal lung disease and recent antibacterial therapy. Although the incidence of infections caused by DRSP is rising, the effect of an increase in the prevalence of resistant pneumococci on mortality is not clear. When respiratory infections occur, rapid diagnosis and prompt, empirical administration of appropriate antibacterial therapy that ensures adequate coverage of DRSP is likely to increase the probability of a successful outcome when treating community-acquired pneumonia in elderly patients, particularly those with multiple risk factors for DRSP. A chest x-ray is recommended for all patients, but other testing such as obtaining a sputum Gram's smear is not necessary and should not prolong the time gap between clinical suspicion of pneumonia and antibacterial administration. The selection of antibacterials should be based upon local resistance patterns of suspected organisms and the bactericidal efficacy of the chosen drugs. If time-dependent agents are chosen and DRSP are possible pathogens, dosing should keep drug concentrations above the minimal inhibitory concentration that is effective for DRSP. Treatment guidelines and recent studies suggest that combination therapy with a beta-lactam and macrolide may be associated with a better outcome in hospitalised patients, and overuse of fluoroquinolones as a single agent may promote quinolone resistance. The ketolides represent a new class of macrolide-like antibacterials that are highly effective in vitro against macrolide- and azalide-resistant pneumococci. Pneumococcal vaccination with the currently available polysaccharide vaccine is thought to confer some preventive benefit (preventing invasive pneumococcal disease), but more effective vaccines, such as nonconjugate protein vaccines, need to be developed that provide broad protection against pneumococcal infection.
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PMID:Drug treatment of pneumococcal pneumonia in the elderly. 1549 50

The treatment of cancer may be associated with various chemotherapy-induced mucocutaneous reactions. One of the mucocutaneous adverse effects of antineoplastic drugs is the toxic local tissue reaction, the extravasation, which occurs in less than 1-2% of cytotoxic infusions. The standard management of vesicant extravasation includes: discontinuing all local infusions, aspiration of any residual drug, elevating the involved limb, local cooling or warm compresses, local anesthesia, antidotes (sodium thiosulfate for alkylating agents, dimethylsulfoxide (DMSO) for anthracyclines and mitomycin, and hyaluronidase for the vinca alkaloids), and finally surgical debridement with plastic surgery reconstruction. Because the anthracyclines are topoisomerase II poisons that are antagonized by topoisomerase II catalytic inhibitors such as dexrazoxane, it seems to be the treatment of choice immediately after extravasation of doxorubicin, epirubicin, daunorubicin, etc. One systemic dose of dexrazoxane after the accident may significantly reduce the toxic tissue lesions. Repeated intralesional injections of GM-CSF may accelerate the wound healing without the need of skin grafts.
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PMID:[The significance of extravasation in oncological care]. 1840 1