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Biomedical subjects

I Zajac

Publications and source records attributed to I Zajac.

28 records · Page 2Linked to original sources
PubMed1977

In vitro studies with cefazaflur and other parenteral cephalosporins.

Cefazaflur has a broad-spectrum of in vitro antibacterial activity equal to or greater than that of the commercially-available cephalosporins. In addition, cefazaflur has activity against isolates of Enterobacter, Citrobacter and indole-positive Proteus; however, this activity decreased markedly when the MIC determinations were carried out with a large inoculum size. A similar inoculum effect was observed with cefamandole, however, cefoxitin's activity was relatively unchanged at increased inoculum sizes. Human serum had a relatively small effect on the in vitro activity of cefazaflur.

Bacteria↗
PubMed1975

A new parenteral cephalosporin. SK&F 59962: in vitro and in vivo antibacterial activity and serum levels in experimental animals.

SK&F 59962, a new parenteral cephalosporin was found to have a high order of in vitro and in vivo antibacterial activity against a broad-spectrum of clinical isolates. When tested in vitro against gram-negative organisms, SK&F 59962 was consistently more active than cefazolin and far superior to cephalothin. This new antibiotic had activity equal to that of cephalothin against gram-positive bacteria. Enterobacter species were found to be susceptible to SK&F 59962. In mouse infection studies using bacterial pathogens, SK&F 59962 had protective activity of the order of that of cefazolin and superior to that of cephalothin. Following parenteral administration the serum profile of SK&F 59962 in the mouse, dog and squirrel monkey was similar to that of cephalothin. SK&F 59962 and cephalothin had lower peak serum concentrations and shorter biologic half-lives than those of cefazolin.

Animals↗
PubMed1975

Laboratory studies with cefatrizine (SK + F 60771), a new broad-spectrum orally-active cephalosporin.

Cefatrizine (SK&F 60771), a new orally-active semisynthetic cephalosporin antibiotic with broad-spectrum antibacterial activity, was compared with cephalexin and cefazolin for in vitro and in vivo antibacterial activity and pharmacokinetic behavior in laboratory animals. The average MIC values obtained with cefatrizine against gram-positive and gram-negative bacteria were superior to those obtained with cephalexin and somewhat poorer than those of cefazolin. In addition, a large percentage of the enterobacter and enterococcus isolates were found to be susceptible. Cefatrizine had a longer biological half-life and a higher peak serum level than either cefazolin or cephalexin when administered parenterally or orally to mice at 20 mg/kg. It had striking in vivo protective activity in mice infected with Escherichia coli, Klebsiella pneumoniae, Enterobacter cloacae, Hemophilus influenzae, Proteus morganii or Staphylococcus aureus reflecting its superior pharmacokinetic profile in this animal species. A variable pharmacokinetic response between animal species was observed when cefatrizine was administered either orally or parenterally to dogs, squirrel monkeys or rabbits.

Administration, Oral↗
PubMed1972

Purification and characterization of epizootic diarrhea of infant mice virus.

Epizootic diarrhea of infant mice virus has been purified from the intestines of infected mice using enzymatic digestion, precipitation with polyethylene glycol, extraction with Genesolv-D, and sucrose step-gradient centrifugation. The purified virus was found to be stable at -70 C or when treated with ether, chloroform, or sodium deoxycholate. Biochemical analysis of purified virions has suggested that the nucleic acid type of epizootic diarrhea of infant mice virus was of the ribonucleic acid type. Preparations of purified virions stained with phosphotungstic acid showed a particle with icosahedral symmetry, 54 +/- 2 nm in diameter and probably composed of 32 hollow capsomeres.

Animals↗
PubMed1969

Differential inhibition of attachment and eclipse activities of HeLa cells for enteroviruses.

Receptor activities of HeLa cells were evaluated for ability to both attach and eclipse enteroviruses after exposure of cells to acid or heat. A modified procedure of acid (pH 1.5) elution of cell-associated virus, as compared with other procedures, provided a general method for the optimal recovery of receptor-bound enteroviruses. With this procedure, eclipse of virus operationally was considered to be that amount of virus infectivity which was determined initially to be cell-associated and which was not dissociable from the cells. HeLa cells killed by heating at 56 C for 30 min could not attach or eclipse poliovirus T1, but they attached and eclipsed coxsackieviruses B1 and B3, and they attached echovirus 6 but did not eclipse it. HeLa cells treated at pH 2.5 for 10 min at 2 C could not attach or eclipse poliovirus T1, but they attached coxsackieviruses B1 and B3 and echovirus 6, although these viruses were not eclipsed. These results showed that, within the operational definition of virus eclipse, the eclipse activity of HeLa cells for some viruses can be irreversibly inactivated without impairing the activity of the receptors for attaching these viruses. The data provided additional evidence that HeLa cells possess specific receptors for the different enteroviruses.

Binding Sites↗