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C Bebear

Publications and source records attributed to C Bebear.

83 records · Page 5Linked to original sources
PubMed1983

[Comparative bacteriostatic activity of 10 cephalosporins against 100 strains of Serratia].

The in vitro activity of 10 cephalosporins was evaluated against 100 different clinical isolates of Serratia. 90% of these strains were inhibited at the following concentrations (microgram/ml): ceftazidime = 0.5; ceftriaxon = 0.9; cefmenoxime = 1; lamoxactam = 1.1; cefotaxime = 1.25; cefotetan = 2; cefoperazone = 28; cefoxitine = 64; cefotiam = 80; ceforanide greater than 512. Ceftazidime was the most potent agent. Ceftriaxon, cefmenoxime, lamoxactam and cefotaxime had also a very high activity. All the strains were clinically susceptible to these 5 cephalosporins (MIC less than or equal to 16). The other cephalosporins were less active.

Cephalosporins↗
PubMed1983

[Preliminary in vitro study of the transplacental passage of spiramycin].

Spiramycin, a true macrolide antibiotic, is the only agent which can be used for the preventive treatment of congenital toxoplasmosis. It gives very high levels in the human placenta, but its transplacental transfer is likely to be very poor, so that it may not cure an already infected foetus. We studied the human placental transfer of spiramycin by an in vitro perfusion model of placentas obtained at term of uncomplicated pregnancies. The transfer rate of spiramycin was found to be close to 9% of the maternal circulating concentrations and 23% of the antipyrine transfer rate, which is only flow-limited. Possible therapeutic implications of these results are discussed.

Antipyrine↗
PubMed1982

A third DNA polymerase from Spiroplasma citri and two other spiroplasmas.

Recently, two DNA polymerases (ScA and ScB) were isolated and characterized from Spiroplasma citri. We now have found a third DNA polymerase (ScC) not only in S. citri but also in the serologically related honeybee spiroplasma BC3 and the unrelated flower spiroplasma BNR1. Enzyme ScC is N-ethylmaleimide (NEM) sensitive. The three DNA polymerases from the honeybee spiroplasma seem to be similar to the respective enzymes of S. citri. However, whereas the NEM-resistant enzyme ScA from S. citri and that from the BC3 honeybee spiroplasma are retained on DEAE-cellulose and require 0.09 M KCl for elution, the NEM-resistant enzyme A from the flower spiroplasma BNR1 is not retained.

Chromatography, DEAE-Cellulose↗
PubMed1979

Separation and partial characterization of two deoxyribonucleic acid polymerases from Spiroplasma citri.

The separation and partial characterization of two deoxyribonucleic acid polymerases from Spiroplasma citri have been achieved. The two enzymes had different elution properties on diethylaminoethyl (DEAE) cellulose and differed in their sensitivity to N-ethylmaleimide (NEM), preference for different template-primers, and sedimentation velocity in linear glycerol gradients. The first enzyme activity, ScA, was retained on DEAE-cellulose and was not inhibited by NEM. Activated deoxyribonucleic acid and poly(dA)-oligo(dT12) were the preferred template-primers. Arabinosyl-cytidine triphosphate had no effect. The sedimentation coefficient of ScA was 6.3s. The second activity, ScB, was not retained on DEAE-cellulose and was inhibited by NEM. Poly(dA)-oligo(dT12) was the preferred template-primer, whereas activated DNA was only poorly utilized. ScB was not affected by arabinosyl-cytidine triphosphate, and its sedimentation coefficient was 4.4s. The polymerization activities of the two enzymes were maximum at 37 to 40 degrees C.

Arabinofuranosylcytosine Triphosphate↗
PubMedDate not supplied

Experimental production of bladder calculi in rats by ureaplasma injection.

Certain infection stones are thought to be linked to urease-possessing bacteria such as Proteus sp. Since ureaplasma also contain urease and are predominantly located in the urogenital tract, their possible role in the formation of infection stones was studied in the rat model described by Friedlander and Braude [2]. Infection stones were produced in Sprague-Dawley and Wistar male rats after injection of ureaplasmas into the renal medulla. In Sprague-Dawley rats, six different ureaplasma strains (serotypes 3 and 5 clinical isolates) were able to produce bladder stones. Acetohydroxamic acid, a urease inhibitor, prevented the formation of the stones. There was no difference in urinary pH or the presence of leukocytes, crystals and ureaplasmas in the urine between rats which presented stones and those which did not. Ureaplasmas could be cultivated only very rarely from rat stones. Similarly, no ureaplasmas could be obtained from human stones.

Animals↗