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Biomedical subjects

J R Haynes

Publications and source records attributed to J R Haynes.

49 records · Page 3Linked to original sources

Blood culture technique based on centrifugation: developmental phase.

A quantitative and flexible blood culture system based on centrifugation of lysed blood over a density layer is described. The effect of relative centrifugal force, centrifugation time, and two different density solutions on the recovery of Staphylococcus aureus, Escherichia coli, pseudomonas aeruginosa, and Candida albicans was determined. To demonstrate the versatility of this technique, the reisolation of 23 representative microorganisms from inoculated normal human blood was determined at a fixed centrifugation speed and time. The potential merits of this technique are discussed and compared with those of conventional blood culture methods.

Blood↗

Blood culture technique based on centrifugation: clinical evaluation.

A total of 1,000 blood samples from patients suspected of having a bacteremia were analyzed concurrently, where possible, by three methods: (i) Trypticase soy broth with sodium polyanethol sulfonate and a CO2 atmosphere: (ii) pour plates with either brain heart infusion agar or Sabouraud dextrose agar; and (iii) centrifugation of the suspected organism in a hypertonic solution. There were 176 positive cultures. The centrifugation technique recovered 73% of the positive cultures. The broth and pour plate techniques recovered 38 and 49%, respectively. The centrifugation technique showed an increased isolation rate for Pseudomonas, fungi, and gram-positive cocci. In general, for each organism the time required for the detection of a positive culture was shortest for the centrifugation technique.

Bacteria↗

Synthesis and antibacterial activities of some chloro analogs of 3 amino-3,4-dihydro-1-hydroxycarbostyril.

The effects of a chloro substituent upon the microbiological activities of 3-amino-3,4-dihydro-1-hydroxycarbostyril were determined. The 5-, 6-, and 7-chloro analogs were synthesized by reductive cyclizations of the appropriately chloro-substituted o-nitrophenylalanines, while the 8-chloro analog was obtained from the N-trifluoroacetyl-3-chloro-2-nitrophenylalanine ethyl ester. All of these compounds were observed to inhibit the growth of Escherichia coli 9723, Leuconostoc dextranicum 8086, and Lactobacillus plantarum 8014. The relative inhibitory activities of the chloro analogs were 7-Cl greater than 6-Cl greater than 8-Cl greater than 5-Cl in E. coli and 7-Cl greater than 6-Cl greater than 8-Cl = 5-Cl in L. dextranicum and L. plantarum. In each of the three microorganisms, the 7-Cl analog was a more effective growth inhibitor than the parent unsubstituted compound. The growth inhibitory activities of this class of compounds were demonstrated to be much more effective than those of the four corresponding lactams, the 5-, 6-, 7-, and 8-chloro analogs of 3-amino-3,4-dihydrocarbostyril.

Anti-Bacterial Agents↗

Manipulation of HIV-1 gp120-specific immune responses elicited via gene gun-based DNA immunization.

Gene gun-based DNA immunization using vectors encoding HIV-1 gp120 or influenza virus nucleoprotein result in Th2-like immune responses following successive immunizations. The codelivery of vectors encoding IL-2, IL-7, or IL-12 blocked this effect by markedly enhancing gp120-specific interferon gamma production, and suppressing IL-4 and IgG1 responses. An unbiased augmentation of all immune responses was observed by increasing the resting period between immunizations. In this case, IFN-gamma production following in vitro stimulation increased by over 1000-fold, while IL-4, IgG1, and IgG2a responses were elevated as well. Interestingly, cytokine gene codelivery, in the context of the longer resting period, provided no additional stimulation of Th1-like responses such as IFN-gamma and IgG2a production, although there was still some suppression of IL-4 production. These data demonstrate that the quality and magnitude of responses elicited following epidermal administration of DNA vaccines can be manipulated by multiple means.

AIDS Vaccines↗