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Biomedical subjects

C L Fox

Publications and source records attributed to C L Fox.

47 records · Page 3Linked to original sources
PubMedDate not supplied

mtDNA analysis in ancient Nubians supports the existence of gene flow between sub-Sahara and North Africa in the Nile Valley.

The Hpal (np3,592) mitochondrial DNA marker is a selectively neutral mutation that is very common in sub-Saharan Africa and is almost absent in North African and European populations. It has been screened in a Meroitic sample from ancient Nubia through PCR amplification and posterior enzyme digestion, to evaluate the sub-Saharan genetic influences in this population. From 29 individuals analysed, only 15 yield positive amplifications, four of them (26.7%) displaying the sub-Saharan African marker. Hpa 1 (np3,592) marker is present in the sub-Saharan populations at a frequency of 68.7 on average. Thus, the frequency of genes from this area in the Merotic Nubian population can be estimated at around 39% (with a confidence interval from 22% to 55%). The frequency obtained fits in a south-north decreasing gradient of Hpa I (np3,592) along the African continent. Results suggest that morphological changes observed historically in the Nubian populations are more likely to be due to the existence of south-north gene flow through the Nile Valley than to in-situ evolution.

Africa↗
PubMedDate not supplied

Combined topical use of silver sulfadiazine and antibiotics as a possible solution to bacterial resistance in burn wounds.

The superior efficacy of quinolones (norfloxacin, pefloxacin, and enoxacin) in controlling burn wound infections signals the discovery of new topical agents. However, there are a few reports on the emergence of resistant mutants to quinolones. Since attempts to develop AgSD resistant strains in vitro were unsuccessful and the emergence of AgSD resistance in vivo is a rare occurrence, we decided to investigate if the combined use of AgSD with other effective antibiotics, especially quinolones, would minimize the development of resistant bacteria. Our in vitro results indicate that when Ps. aeruginosa cultures were serially transferred 10 times through subinhibitory concentrations of norfloxacin, pefloxacin, etc., the MIC increased 40 times while when the cultures were passed through a combination of AgSD and these quinolones, the MIC of quinolones increased only tenfold. In vivo, when burned mice infected with either AgSD sensitive or resistant Ps. aeruginosa strains were treated with a topical cream containing 10mM silver sulfadiazine and 5mM norfloxacin or 5mM pefloxacin, the mortality was much lower than that of 10mM silver sulfadiazine alone or 5mM quinolones alone. Thus, combined use of silver sulfadiazine and quinolones appears to diminish the ability of Ps. aeruginosa strains to form resistant mutants. Furthermore, when the combination is used as a topical agent in burn wounds, lesser amounts of the individual drug are needed to control infection thereby reducing the toxic effects, if any, associated with these drugs. This combination does not in any way interfere with the antifungal or antibacterial properties of these individual drugs.

Administration, Topical↗
PubMedDate not supplied

Comparative evaluation of zinc sulfadiazine and silver sulfadiazine in burn wound infection.

One percent silver sulfadiazine has been commonly used as a topical antimicrobial agent after a burn injury. Incidence of burn wound colonization by Staphylococcus aureus in patients treated with silver sulfadiazine has spurred research for other agents. A topical preparation that contains zinc and sulfadiazine (Zad-G) was evaluated for in vitro antibacterial spectrum and in vivo efficacy. Muscle biopsy specimens of rats treated with Zad-G appear to have fewer colonies of S. aureus than groups treated with silver sulfadiazine. Topical therapy with Zad-G for patients with burns was comfortable, reduced wound infection, and was comparable to therapy with silver sulfadiazine. A topical Zad-G preparation that contains zinc sulfadiazine appears to be an effective alternative to silver sulfadiazine in the treatment of burn wounds.

Administration, Topical↗
PubMedDate not supplied

Hypertonic balanced sodium solution in burn shock.

This study was designed to ascertain the most effective sodium solution for resuscitation after potentially fatal thermal injury. Solutions containing from 75 to 300 mEq/L of sodium were administered in various doses to mice subjected to a standarized scald. Their effectiveness was evaluated by comparison of the 24-hour mortalities, and also by the changes in body weight, urine and plasma electrolytes, etc. A wide range of solutions was effective; the optimal intake was approximately 22.5 mEq of sodium per kilogram of body weight. This was most efficiently given in a solution containing 225 mEq of sodium and 160 mEq of chloride per liter. Survival increased when the sodium to chloride ratio more closely approximated that oe plasma. Hypotonic solutions were less effective at all dosage levels.

Animals↗