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Biomedical subjects

N Sullivan

Publications and source records attributed to N Sullivan.

48 records · Page 3Linked to original sources
PubMed1984

In vitro and in vivo neutralizing activity of human colostrum and milk against purified toxins A and B of Clostridium difficile.

The neutralizing activity (NA) of supernates of colostral samples collected postpartum from 55 women and tested against a 50% cytopathic dose of purified toxins A and B of Clostridium difficile was evaluated in Y1 adrenal cells. Thirty-one (56%) of the samples had NA against one or both toxins. Samples of breast milk were collected postpartum from five women-three had colostral NA and two did not. All milk specimens from the three women with colostral NA had NA titers of 1:1-1:4 throughout the study (609 days in one case). Samples from the two women without colostral NA did not exhibit NA during a 60-day follow-up period. In suckling mice either toxin plus human milk with in vitro NA elicited significantly less fluid accumulation than did toxin plus diluent or toxin plus milk without in vitro NA (P less than .025 to P less than .05). Twelve (63%) of 19 milk samples with in vitro NA against toxin A and 15 (65%) of 23 with in vitro NA against toxin B inhibited fluid accumulation caused by the corresponding toxin. In vitro NA against toxin A appeared to reside in the secretory IgA fraction of one milk sample assessed by immune precipitation. The results suggest that human milk may protect newborn infants against toxins A and B of C. difficile.

Adrenal Glands↗
PubMed1980

Attitudes toward the geriatric patient among family practice residents.

For the Family Practitioner, elderly patients are a highly significant group. In the past, some health professionals have expressed negative attitudes toward the elderly. Thus a need exists to study specific factors that may influence a Family Practice resident's willingness to treat older patients. A Likert-type questionnaire was developed that utilized the Thurstone-Likert discrimination technique. Five categories were chosen for study: general attitudes, cost effectiveness, time and energy, therapeutic potential, and educational preparation. Responses of 150 Family Practice residents were then analyzed. The attitudes of the residents were significantly positive in all categories except Educational Preparation. Noteworthy was the finding that the attitudes improved from the first year through the third year of residency. This is the first medical specialty group to demonstrate such a trend. Certain negative attitudes observed in the Educational Preparation category re-emphasize the need for training programs to improve professional geriatric instruction.

Aged↗
PubMed1979

Antibacterial properties of lidocaine.

The inhibitory effect of lidocaine and lidocaine plus methylparaben as a preservative was studied with 25 strains of bacteria. The tested strains were mixed with each topical anesthetic preparation, and quantitative cultures were performed on aspirates at 0, 30, 60, and 120 minutes. Results were compared to counts obtained in a lactated Ringer's solution, which were sampled at the same intervals. Lidocaine (1 percent solution) reduced quantitative counts after 120 minutes of contact by over one log for only six of the 25 strains tested. Lidocaine plus methylparaben reduced quantitative counts to a somewhat greater extent; nevertheless, all strains except Bacteroides melaninogenicus were recovered in relatively high concentrations at each sampling interval. Numerous previous studies have shown that topical anesthetic agents are toxic to bacteria. The results of this study show that this toxic effect is not sufficiently severe to prevent the recovery of most pathogens of the lower respiratory tract in bronchoscopic aspirates.

Anti-Bacterial Agents↗
PubMed1978

Antimicrobial activity of metronidazole in anaerobic bacteria.

The antimicrobial activity of metronidazole was investigated in anaerobic bacteria by use of time-viability studies. This antimicrobial agent has a rapid onset of bactericidal activity under proper reducing conditions. The bactericidal rates were not affected by inoculum size or nutritional requirements, nor by inhibition of growth and protein synthesis by chloramphenicol. Using supernatant fractions of actively growing cultures of susceptible organisms, we observed a disappearance of metronidazole and a loss of biological activity, but there was no significant change in preparations from resistant bacteria. The decrease in drug concentration with susceptible cells occurred during the time that its bactericidal action was being exerted. Extracts from susceptible organisms rapidly reduced the concentration of metronidazole, confirming previous observations which suggest that the drug acts as a terminal electron acceptor. Radioisotope experiments with [14C]metronidazole revealed that the compound was taken up by both resistant and susceptible bacteria, although there was a difference in rate and extent of accumulation. These studies demonstrate that metronidazole's antimicrobial activity against anaerobic bacteria is bactericidal and independent of growth rate, and that it involves the uptake and metabolism of the compound.

Bacteria, Anaerobic↗