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Biomedical subjects

D C Shanson

Publications and source records attributed to D C Shanson.

33 records · Page 2Linked to original sources
PubMed1977

Serum gentamicin assays of 100 clinical serum samples by a rapid 40 degrees C. Klebsiella method compared with overnight plate diffusion and acetyltransferase assays.

We have compared the results of gentamicin assay of 100 clinical serum samples by a rapid 40 degrees C plate diffusion method, an overnight plate assay at 37 degrees C, and radioactive acetyltransferase methods. The results of assay obtained by both plate diffusion methods agreed closely. There was excellent correlation between the results of acetyltransferase and plate assays provided that human serum gentamicin standards were used for the acetyltransferase assay and turbid sera were excluded. Lipaemic sera were associated with falsely high results by the acetyltransferase method. There was no difference in specificity between the methods when antibiotics other than gentamicin were present. Much less skilled technician time was required to perform the rapid 40 degrees C plate method than the radioactive acetyltransferase method. The 40 degrees C plate method is preferred for routine serum gentamicin assays in our clinical laboratories.

Acetyltransferases↗
PubMed1976

Outbreak of hospital infection with a strain of Staphylococcus aureus resistant to gentamicin and methicillin.

A previously unreported strain of Staphylococcus aureus, resistant to both gentamicin and methicillin, as well as other antibiotics, caused an outbreak of hospital infection involving 17 patinets and 8 staff. In this outbreak none of the patients had received previous aminoglycoside therapy. The epidemic strain was eliminated by the use of strict measures for the control of infection.

Cross Infection↗
PubMed1976

Rapid microbiologic assay of tobramycin.

Different, rapid, plate diffusion assays of tobramycin in serum were compared with each other and with an overnight assay. These assays were done with Klebsiella edwardsii var. atlantae, which was resistant to many antibiotics. One of the rapid assays of tobramycin tested used a 1:50-1:100 dilution of an overnight culture, and results were recorded after incubation for 5 hr at 35 C. Two shorter assays were also tested with a 1:10 dilution of an overnight assay. The 5-hr assay was as reproducible and as accurate as the overnight assay. The 2.5-hr assay at 35 C proved to be an inaccurate method. Incubation of the assay at 40 C instead of 35 C resulted in more rapid growth of K. edwardsii and in the production by tobramycin of larger and sharper zones of inhibition. The 2.5-hr assay at 40 C was as reproducible and as accurate as the 5-hr and the overnight assays.

Animals↗
PubMed1975

A new selective medium for the isolation of Salmonellae other than Salmonella typhi.

A medium consisting of a MacConkey's base with added magnesium, calcium, cobalt, zinc, thiosulphate, novobiocin, iron dextran, Tween 80 and EDTA has been found highly selective for Salmonellaparatyphi B and most of the food poisoning salmonellae that commonly occur in Britain. Nearly all the normal faecal flora is inhibited.

Bacteriological Techniques↗
PubMed1975

An experimental comparison of Thiol broth with Brewer's thioglycollate for anaerobic blood cultures.

In a series of simulated blood culture experiments, small inocula of eight different strains of Bacteroides and five strains of anaerobic cocci were added to Difco Thiol broth and Southern Group Brewer's thioglycollate. Both methods enabled all of the strains to be isolated after one to three days' incubation, with the exception of Bacteroides melaninogenicus, and most strains to survive after one week. B. melaninogenicus grew more quickly in Difco Thiol broth than in Southern Group Brewer's whereas three strains of anaerobic cocci were isolated first from Southern Group Brewer's. Difco Thiol broth appears to be a satisfactory alternative to Southern Group Brewer's for the isolation of non-sporing anaerobes likely to be found in the blood.

Anaerobiosis↗
PubMedDate not supplied

Cryptosporidiosis in HIV-seropositive patients.

The incidence of cryptosporidiosis in our unit has increased over the last 6 years, being diagnosed in approximately 5 per cent of all patients with HIV infection and in 21 per cent of those with AIDS, but a marked seasonal variation occurs. We have studied the course of the infection in 128 patients and identified four clinical patterns of disease: transient (28.7 per cent), chronic (59.7 per cent), fulminant (7.8 per cent) and asymptomatic (3.9 per cent). Transient disease occurred in patients with a wide range of CD4 lymphocyte counts, but was more common in less immunosuppressed patients. Fulminant disease, defined by the passage of more than 2 l of stool/day from the time of presentation, only occurred in patients with a CD4 count less than 50/mm3. This group had lost more than 7 kg in weight at presentation and more commonly had other intercurrent gastrointestinal infections. They survived for a median of only 5 weeks, compared with 20 weeks for those with chronic diarrhoea and 36 weeks for those with transient infection. The survival was unaffected by any treatment other than zidovudine. Cryptosporidiosis in HIV-infected individuals is a heterogeneous disease.

AIDS-Related Opportunistic Infections↗