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Biomedical subjects

K Shannon

Publications and source records attributed to K Shannon.

At least 109 records · Page 6Linked to original sources
PubMed1982

In vitro antibacterial activity of norfloxacin (MK-0366).

The in vitro activity of norfloxacin (MK-0366) compared with that of beta-lactam antibiotics and, where appropriate of gentamicin or metronidazole was assessed against recent clinical isolates of common bacteria. The compound was highly active against most enterobacteria (minimal inhibitory concentrations [MICs], 0.008 to 32 micrograms/ml; 90% inhibited by 0.25 micrograms/ml), Haemophilus influenzae (MICs, 0.03 to 0.12 micrograms/ml), and Neisseria gonorrhoeae (MICs, 0.008 to 0.016 micrograms/ml). It was also active against Pseudomonas aeruginosa (MICs, 0.12 to 2 micrograms/ml), most other pseudomonads (MICs, 0.03 to 32 micrograms/ml), and Acinetobacter calcoaceticus (MICs 0.06 to 4 micrograms/ml). Norfloxacin was somewhat less active against staphylococci (MICs, 0.25 to 4 micrograms/ml; 1 microgram/ml required to inhibit 50% of isolates) and streptococci (MICs, 0.5 to 64 micrograms/ml). Members of the Bacteroides fragilis group of anaerobes were relatively resistant to norfloxacin (MICs, 8 to 128 micrograms/ml), as were most other anaerobes.

Aerobiosis↗
PubMed1982

Severe hemolytic anemia in black children with glucose-6-phosphate dehydrogenase deficiency.

The clinical spectrum of hemolytic anemia as a consequence of oxidant stress in black children deficient in erythrocyte glucose-6-phosphate dehydrogenase (G-6-PD) has not been well described in the pediatric literature. During a 3 1/2-year period 14 hospitalized black G-6-PD-deficient children with moderate to severe hemolytic reactions were studied. The vast majority (13/14) were boys and were less than 3 years of age. Nine of the patients required blood transfusion. Eleven of the 14 episodes occurred with infection (five bacterial, six viral); those children with viral syndromes tended to have more severe hemolysis. Naphthalene was responsible for three episodes, but oxidant drugs were implicated in no instances. Findings on the blood smears of most subjects included irregular dense misshapen erythrocytes with asymmetrical distribution of hemoglobin and an adjacent membrane-bound clear zone ("eccentrocytes"). It is concluded that hemolytic reactions in the black G-6-PD-deficient child may be severe, are most commonly associated with infection, and are frequently characterized by distinctive erythrocyte morphology.

Anemia, Hemolytic↗
PubMed1980

In vitro antibacterial activity and susceptibility of cefsulodin, an antipseudomonal cephalosporin, to beta-lactamases.

Cefsulodin sodium (SCE-129, CGP-7174/E), active in minimum inhibitory concentrations (MICs) of 0.5 to 64 microgram/ml, was about 16- to 32-fold more active than carbenicillin against Psuedomonas aeruginosa. It was also active against P. diminuta, P. maltophilia, P. paucimobilis, and P. pseudoalcaligenes (MICs of 1 to 32 microgram/ml) but not against other species of Pseudomonas or other gram-negative bacteria. Except with highly carbenicillin-resistant isolates, MICs of cefsulodin for P. aeruginosa were little affected by an increase in the inoculum. With a small inoculum, minimum bactericidal concentrations (MBCs) were the same as or twice the MIC, but increasing the inoculum had a greater effect on the MBC than on the MIC. Cefsulodin was not hydrolyzed by the beta-lactamase induced in P. aeruginosa by growth in the presence of benzylpenicillin and was a poor substrate for beta-lactamases from Enterobacter cloacae and Proteus morganii. However, it was hydrolyzed, albeit slowly, by the beta-lactamase produced by most of our highly carbenicillin-resistant isolates of P. aeruginosa and by TEM-type beta-lactamases.

Bacteria↗
PubMed1980

In vitro antibacterial activity and susceptibility of the cephalosporin Ro 13-9904 to beta-lactamases.

The in vitro activity of Ro 13-9904 was assessed against clinical isolated of common bacteria. Its activity against most enterobacteria was similar to that of cefotaxime and moxalactam, but it was even more active than these compounds against all Proteus species. It was also highly active against Haemophilus influenzae and Neisseria gonorrhoeae, including beta-lactamase producers. Like cefotaxime and moxalactam, Or 13-9904 was approximately eightfold more active than carbenicillin against most isolates of Pseudomonas aeruginosa and also active against highly carbenicillin-resistant isolates, but it was relatively inactive against moderately carbenicillin-resistant isolates. Ro 13-9904 also resembled cefotaxime and moxalactam in that it was active, though less so than cephaloridine, against staphylococci and streptococci, except for methicillin-resistant staphylococci and Streptococcus faecalis, which were resistant to it. It was less active than cefoxitin but slightly more active than ampicillin against both Bacteroides fragilis and other Bacteroides spp. Ro 13-9904 was resistant to most beta-lactamases but was attacked by enzymes from B. fragilis, isolates of indole-positive Proteus species, and also by a cefoxitin-hydrolyzing enzyme from an isolate of Enterobacter cloacae.

Bacteria↗
PubMed1978

Echocardiographic features of total anomalous pulmonary venous drainage into the coronary sinus.

Echocardiograms were obtained from five infants with total anomalous pulmonary venous drainage to the coronary sinus or the portal system or the superior vena cava and from one child with a secundum atrial septal defect and a large coronary sinus due to persistence of the left superior vena cava. The results demonstrate that an enlarged coronary sinus is positioned consistently posterior to the left atrium in approximately the same horizontal plane as the aortic valve. Echocardiographically the coronary sinus can be located as an echo complex behind the left atrium by using the aortic root as a reference point. The echo complex can be differentiated from the other spurious echoes in the left atrium by its characteristic phasic motions. The additional demonstration of the enlarged common pulmonary venous chamber behind the right atrium confirms the diagnosis of anomalous pulmonary venous drainage to the coronary sinus. For other types of anomalous pulmonary venous return, anatomic diagnosis with single crystal M mode echocardiography is not always possible because of the positional variability of the common pulmonary venous chamber in relation to the left atrium.

Coronary Vessel Anomalies↗
PubMed1978

The activity of cephalosporins on beta-lactamase-producing Neisseria gonorrhoeae.

The antibacterial activity of cephaloridine, cephalothin, cephalexin, cephradine, cefazolin, cefamandole, cefuroxime and cefoxitin was determined for six beta-lactamase-producing gonococci isolated in Great Britain and the USA. Cefuroxime was most active against small and large inocula, then cefoxitin, while cephaloridine was least active. Cefamandole was more active than cefazolin and cephalothin, but only on small inocula, and these three antibiotics, with the slightly inferior cephalexin and cephradine, all had moderate activity against large inocula. The inoculum effect (or lack of it) with cephaloridine, cefamandole, cefoxitin, and possibly cefazolin and cephalothin, may be explicable in terms of the level of their susceptibility to enzymic degradation, but this appears not to be true of the inoculum effect with cefuroxime, cephalexin and cephradine. The enzymes from the various strains had closely similar isoelectric points, apparently the same as that for TEM I from E. coli.

Amidohydrolases↗