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Query: UMLS:C0014118 (endocarditis)
 15,629 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The current trend in antibiotic prophylaxis for prevention of endocarditis is toward more simple, effective regimens to promote better patient and dentist compliance. All national medical groups are now recommending oral regimens for all at-risk patients, and most of these groups recommend single-dose oral regimens. The Swiss Working Group recommends multiple-dose amoxicillin for high-risk patients. The American Heart Association recommends two-dose oral regimens for all at-risk patients. Clindamycin appears to be the second drug of choice. The many pharmacokinetically different erythromycin preparations and the high rate of intolerance to many of these preparations has led to this change. No national or international medical groups recommended prophylaxis for patients with prosthetic joints. Most reviews conclude that there is little or no scientific evidence to support this use. It is time to stop the practice of prophylaxis for patients with prosthetic joints. The only patients with joint prostheses who should even be considered for prophylaxis are those patients considered at "high" risk.
Curr Opin Dent 1992 Sep
PMID:Antibiotic prophylaxis for prevention of bacterial endocarditis and infections of major joint prostheses [corrected]. 130 Jan 9

Infections with enterococci that are resistant to multiple antibiotics are an emerging clinical problem. We evaluated the antibiotic treatment of experimental enterococcal endocarditis caused by two strains with different mechanisms of penicillin resistance. Enterococcus faecalis HH-22 is resistant to aminoglycosides and penicillin on the basis of plasmid-mediated modifying enzymes; Enterococcus raffinosus SF-195 is susceptible to aminoglycosides but is resistant to penicillin on the basis of low-affinity penicillin-binding proteins. Animals infected with strain HH-22 received 5 days of treatment with the following: no treatment; daptomycin (20 mg/kg of body weight twice daily [b.i.d.], intramuscularly [i.m.]), vancomycin (20 mg/kg b.i.d., intravenously), or ampicillin (100 mg/kg three times daily, i.m.) plus gentamicin (2.5 mg/kg b.i.d. i.m.). Although vancomycin was superior to ampicillin-gentamicin (P less than 0.01), daptomycin was significantly better than all other treatment regimens (P less than 0.01) in reducing intravegetation enterococcal densities, although no vegetations were rendered culture negative by this agent. Animals infected with strain SF-195 received 5 days of no therapy, ampicillin, ampicillin-gentamicin, vancomycin, or daptomycin (all at the dosage regimens described above). Daptomycin, vancomycin, and ampicillin-gentamicin each lowered intravegetation enterococcal densities significantly better than did ampicillin monotherapy or no treatment (P less than 0.01); moreover, these three treatment regimens rendered significantly more vegetations culture negative than did ampicillin monotherapy or no treatment (P less than 0.05). Serum daptomycin levels remained above the MICs and MBCs for both enterococcal strains throughout the 12-h dosing interval used in the study. Daptomycin and vancomycin were both active in vivo in these models of experimental enterococcal endocarditis caused by penicillin-resistant strains, irrespective of the mechanism of resistance. This activity correlated with the unique cell wall sites of action of these agents (binding to lipoteichoic acid and pentapeptide precursor, respectively) compared with the sites of action of beta-lactams (penicillin-binding proteins). Beta-Lactamase production by strain HH-22 precluded in vivo efficacy with ampicillin-gentamicin combinations. In contrast, this combination was active in vivo against strain SF-195, which exhibited intermediate-level penicillin resistance (MIC, 32 micrograms/ml), likely reflecting the ability of high-dose ampicillin to achieve enough binding to low-affinity penicillin-binding proteins to cause augmented aminoglycoside uptake.
Antimicrob Agents Chemother 1992 Sep
PMID:Comparison of daptomycin, vancomycin, and ampicillin-gentamicin for treatment of experimental endocarditis caused by penicillin-resistant enterococci. 132 32

The efficacy of tazobactam, a beta-lactamase inhibitor, in combination with piperacillin, was studied in vitro and in rabbit experimental endocarditis due to a Klebsiella pneumoniae strain (KpR) producing an extended-spectrum beta-lactamase, TEM-3, or its nonproducing variant (KpS). In vitro, piperacillin was active against KpS (MIC = 4 micrograms/ml, MBC = 8 micrograms/ml with 10(7)-CFU/ml inoculum) but not against KpR (MIC = MBC = 256 micrograms/ml). Tazobactam (1 microgram/ml) restored the activity of piperacillin against KpR (MIC = 2 micrograms/ml, MBC = 4 micrograms/ml). Gentamicin was active against both strains (MIC = 0.25 and 0.5 micrograms/ml for KpS and KpR, respectively). The piperacillin-tazobactam-gentamicin combination was synergistic in vitro. The piperacillin/tazobactam ratio in plasma and in vegetations was always lower than the 4/1 injected dose ratio. In vivo, piperacillin (300 mg/kg of body weight four times a day [QID]) was active against KpS but not against KpR. Tazobactam (75 mg/kg QID) was able to restore the in vivo effect of piperacillin (300 mg/kg QID) against KpR (-3.0 log10 CFU/g of vegetation versus that of controls). Gentamicin (4 mg/kg twice a day [BID]) was active against both strains. Compared with controls, the combination of gentamicin plus piperacillin against KpS (-5.6 log10 CFU/g of vegetation), and the gentamicin-piperacillin-tazobactam combination against KpR (-4.4 log10 CFU/g of vegetation) achieved the greatest decrease in bacterial counts in vegetations and were the only regimens that significantly increased the proportion of sterile vegetations. It is concluded that (i) tazobactam was able to restore the effect of piperacillin against a TEM-3 extended-spectrum Beta-lactamase-producing strain of K. pneumoniae, both in vitro and in a severe experimental infection with high inoculum, when used in a 4/1 piperacillin/tazobactam dose ratio; (ii) gentamicin alone was effective because of the high peak/MBC ratio in plasma; (iii) piperacillin-tazobactam-gentamicin, probably because of the effect of gentamicin in reducing bacterial inoculum in vivo, as stressed by the results obtained by piperacillin-gentamicin against KpS, may be the most effective regimen against KpR.
Antimicrob Agents Chemother 1992 Sep
PMID:Piperacillin, tazobactam, and gentamicin alone or combined in an endocarditis model of infection by a TEM-3-producing strain of Klebsiella pneumoniae or its susceptible variant. 132 34

Mycobacterial infection is an uncommon but very serious complication of heart valve replacement and other forms of cardiac surgery. Tuberculosis has been a rare complication of valve replacement in the industrially developed countries owing to the low incidence of that disease in such countries. Most reported cases are associated with the insertion of human allograft valves. Valvular tuberculosis could become a more serious problem if heart valve replacement surgery is used to any extent in countries where tuberculosis is common. The majority of other mycobacterial infections occurring after heart surgery have, for unknown reasons, been due to the rapid growers M. chelonae and M. fortuitum. Porcine xenograft valves have been contaminated by M. chelonae, possibly during manufacture as this is not a natural pathogen of pigs. A minority of patients receiving valves known to be contaminated by M. chelonae subsequently developed valve disease. Mycobacterial disease following insertion of mechanical valves is a very uncommon occurrence but the prognosis is poor. There have been several outbreaks of infection of the sternotomy wound by M. chelonae and M. fortuitum and, although the prognosis is better than for mycobacterial endocarditis, treatment, especially for infections due to M. chelonae, often involves extensive debridement including removal of the entire sternum. In view of the poor response to therapy, prevention by avoidance of contamination of all surgical materials, including implanted valves, by environmental mycobacteria is of paramount importance.
J Heart Valve Dis 1992 Sep
PMID:Mycobacterial infections following heart valve replacement. 134 Dec 13

As the number of patients undergoing cardiac valve replacement has grown, valve reoperations have become increasingly frequent. The newer generations of mechanical valves are far more efficient and freer from structural failure than the older ones. However, other valve and non-valve related complications still constitute a major cause of morbidity and mortality. On the other hand, bioprostheses, implanted in large numbers in the 1970's and early 1980's, have now gone into the second decade of life since implantation, when biodegradation becomes more frequent. Reoperations are technically more demanding than the original valve procedures because of the mediastinal and pericardial adhesions and the condition of the anulus after removal of the previous prosthesis. Greater awareness of the most dangerous steps and refinements to surgical technique have contributed to the decreased mortality observed in recent years. The risk is higher in certain conditions, such as the presence of prosthetic valve endocarditis and the patient being operated on an emergency basis in NYHA functional class IV. It may also be increased in females and the elderly. Multiple reoperations also carry a higher risk in most surgeon's experience. However, elective reoperations for defective mechanical valves and for replacement of a previously repaired mitral valve carry similar mortality rates to primary valve replacement procedures. The global mortality rates have not been significantly higher in the hands of experienced surgeons working in centers where reoperations are performed frequently. In smaller series high mortality rates are a constant, which underscores the importance of the learning curve. The indications for reoperation must therefore consider all risk factors and, when possible, the procedure must be performed by those who have the most experience. Under these circumstances, elective re-replacement of degenerating bioprostheses and of defective mechanical valves in asymptomatic patients may be advisable.
J Heart Valve Dis 1992 Sep
PMID:Reoperations on cardiac valves. 134 Dec 18

Nine Haemophilus species strains, all beta-lactamase negative, isolated from patients with endocarditis were tested in killing curve experiments. Antibiotics used were penicillin, amoxicillin, aztreonam alone and in combination with tobramycin, as well as ciprofloxacin alone. Synergism between beta-lactams and tobramycin with reduction of colony counts to zero was seen after 24 h for H. influenzae, H. parainfluenzae and H. segnis strains. Ciprofloxacin was as effective as beta-lactam-tobramycin combinations. The H. aphrophilus strain was not killed as effectively as other strains by any of the antibiotics.
APMIS 1992 Sep
PMID:Killing curve activity of ciprofloxacin is comparable to synergistic effect of beta-lactam-tobramycin combinations against Haemophilus species endocarditis strains. 138 4

McGowan and Tuohy carried out a survey in Belfast in 1968 to identify patients with cardiac lesions susceptible to infective endocarditis. They also asked whether adequate precautions had been taken by the patients' medical and dental advisers in respect of antibiotic cover for dental surgical procedures. This survey has now been repeated in the Belfast and Glasgow Dental Schools. When compared with those of 1968, the results of these recent studies show that while more 'at risk' patients are receiving antibiotic cover for dental surgical procedures there is still room for improvement in the advice given to patients by medical and dental practitioners.
Br Dent J 1992 Sep 19
PMID:Dental care of patients susceptible to infective endocarditis. 144 53

A 26 year old Saudi man with features of both Loeffer's endocarditis and endomyocardial fibrosis presented with mild symptoms and pulmonary emboli. Echocardiographic examination showed obliteration of the right ventricular apex by an attached mass. The results of haemodynamic studies were somewhat abnormal and medical treatment was started. Despite anticoagulation with warfarin the patient's condition deteriorated rapidly over a four month period after a further episode of pulmonary embolism and the development of pulmonary hypertension. Two haemodynamic studies performed four months apart were typical of pulmonary hypertension and later right ventricular failure; they showed none of the characteristics of restriction. Pulmonary embolectomy was attempted but there was no cleavage plane between the organised thrombi and the endothelium of the pulmonary artery. The patient died of severe pulmonary hypertension and right ventricular failure several days after operation. Surgical intervention in the early stages of right-sided endomyocardial fibrosis might have prevented the development of pulmonary embolism and pulmonary hypertension.
Br Heart J 1992 Sep
PMID:Right-sided endomyocardial fibrosis with recurrent pulmonary emboli leading to irreversible pulmonary hypertension. 138 68

Blastoschizomyces capitatus Salkin, Gordon, Samsonoff et Rieder was found to be the etiologic agent of endocarditis in a patient with a prosthetic mitral valve. Cultures inoculated with peripheral blood and portions of the valve yielded B. capitatus. Examination of stained tissue sections revealed the presence of fungal filaments morphologically consistent with this organism. The salient characteristics of B. capitatus and the factors contributing to its recognition as a distinct taxon are described.
J Clin Microbiol 1992 Sep
PMID:Endocarditis caused by Blastoschizomyces capitatus and taxonomic review of the genus. 140 Sep 96

Two colonial variants of Staphylococcus epidermidis were isolated from the valvular tissue of a patient with native valve endocarditis. In addition to differing in colonial morphology, the two variants differed in hemolysis on blood-containing media, in adherence capacity, and in the expression of certain enzymes. Under suitable conditions, both variants were themselves capable of phenotypic variation, although they differed in the rate at which variants were generated. The variants yielded identical profiles on restriction endonuclease analysis of plasmid DNA and pulsed-field gel electrophoresis of whole-cell DNA. This report suggests a possible role for phenotypic variation in coagulase-negative staphylococcal virulence. Congo red agar would be an excellent medium for studying the contribution of variation to the virulence of these organisms.
J Clin Microbiol 1992 Sep
PMID:Phenotypic variation of Staphylococcus epidermidis isolated from a patient with native valve endocarditis. 140 Oct 3


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