Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0348321 (Haemophilus)
 15,372 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Concentrations of bacteria in cerebrospinal fluid ranged from 4.5 X 10(3) to 3 X 10(8) colony-forming units/ml in 27 patients with bacterial meningitis before antibiotic therapy and from 4 X 10(1) to 1.4 X 10(6) CFU/ml in four patients after one to two days of antibiotic therapy. All patients with persistent positive cultures had pretreatment concentrations of 10(7) CFU/ml or greater. A significant association was observed between cerebrospinal fluid lactic acid dehydrogenase activity and concentrations of bacteria (p less than 0.01). Large inocula of Hemophilus influenzae type b (10(7)) increased the minimal inhibitory concentration for penicillin and ampicillin but not for chloramphenicol. The minimal inhibitory concentration of each of the three antibiotics increased when group B streptococci were assayed. These data indicate that persistence of a positive culture may be related to large initial concentrations of bacteria. The relative "resistance" in vitro of large inocula possibly contributes to this persistence. These observations are also consistent with the hypothesis that lactic acid dehydrogenase activity in cerebrospinal fluid is derived from bacteria.
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PMID:Concentrations of bacteria in cerebrospinal fluid of patients with bacterial meningitis. 0 35

A series of N-alkylmaleimides varying in chain length from N-ethyl up to and including N-heptyl, was shown to effectively inactivate Haemophilus influenzae D-lactate dehydrogenase at pH 7.0 and 25 degrees C in processes proposed to involve covalent modification of cysteine residues. The inactivation proceeded through an initial reversible binding of maleimides facilitated by nonpolar interactions with a hydrophobic region of the enzyme. Subsequent irreversible inactivation of the enzyme indicated the modification of a fast-reacting group leading to approx. 80% loss of enzyme activity followed by a second slower-reacting modification process. At saturating concentrations of maleimides, the second inactivation process exhibited a common pseudo-first-order rate constant of 0.6 min-1. The initial reversible binding of N-alkylmaleimides resulted in inhibition of the enzyme that was competitive with respect to NADH. Positive chain length effects were observed in the second-order rate constants for inactivation and in the 6-fold better binding of N-heptylmaleimide as compared to that for N-ethylmaleimide. It is suggested that the nonpolar interactions stabilizing the 1,4-dihydronicotinamide moiety of the reduced coenzyme also facilitate the initial binding of N-alkylmaleimides.
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PMID:Nonpolar interactions in the maleimide inactivation of Haemophilus influenzae D-lactate dehydrogenase. 237 5