Search PubMed⌕ Search

Biomedical subjects

A Eldad

Publications and source records attributed to A Eldad.

97 records · Page 6Linked to original sources

A simplified testing system to evaluate performance after transplantation of human skin preserved in glycerol or in liquid nitrogen.

We have designed and tested a mouse recipient model for evaluation and direct comparison of skin-preservation procedures. Glycerolized skin was compared with cryopreserved and fresh cadaveric skin. Human skin samples were grafted on Balb/c mice, and primary take was evaluated after 4 and 7 days. The results demonstrate that although all grafted specimens were initially accepted as indicated by gross observations, histologic differences were evident and significant. Cryopreserved skin grafts performed better than did glycerolized skin even after a transplantation period as short as 4 days; this difference became even more pronounced after 7 days. Both methods of preservation provided a less successful product than did fresh viable cadaveric skin. However, for very short periods of grafting the performance of glycerolized skin might be considered adequate (79% compared with cryopreserved). Because the present study used an immunocompetent xenogeneic model, it is possible that the period of adequate allogeneic grafting will be prolonged in patients who are immunosuppressed. The present model is simple to use, requires a minimum of maintenance and expertise, and has inherent clinical relevance, because it is concerned primarily with the clinical performance of the skin. Thus it may be used as a quality control test for banked skin.

Animals↗

Phosphorous burns: evaluation of various modalities for primary treatment.

White phosphorus is used in many types of military munitions, in fireworks, and in industrial and agricultural products. It ignites spontaneously and causes deep thermal injuries. It may also cause multiorgan failure because of its toxic effects on erythrocytes, liver, kidneys, and heart. Our previous studies demonstrated deleterious effects of copper sulfate. Only copious water irrigation was effective. This study examined other modalities of treatment and a free oxygen radical scavenger. One of the treatments seemed to have some beneficial effects, but simple water irrigation was much more effective. Superoxide dismutase, a free radical scavenger, reduced hepatic damage and adjacent skin flap destruction but did not prevent death of the animal receiving the high dose of white phosphorus used in the present setup.

Animals↗

Transplantation performance of human skin cryopreserved by programmed or stepwise freezing and stored at -80 degrees C or -180 degrees C.

We developed a mouse recipient model that was used to evaluate and compare four cryopreservation procedures for human cadaveric skin stored for two time periods. Skin specimens were identically processed and preserved by programmed (1 degree C/min), or stepwise freezing, and stored at -180 degrees C or -80 degrees C for periods of 1 month and 6 to 10 months. Samples were grafted on Balb/c mice, and primary take was evaluated after 7 days. The results indicate that although all grafted specimens were initially accepted, as indicated by gross observations, histologic differences were evident and significant. The study groups were analyzed for the effect of method and skin sample variety; the effect of freezing procedure and temperature level; time effect (storage period); and advantage of method 1 (programmed freezing at -180 degrees C) over the other methods. The significance (p value) was determined for separate histologic criteria and average skin score or quality. The overall results indicate that average score of skin preserved by method 1 is highest for both storage periods. This method has an almost significant advantage (p = 0.057) over the others on quality of skin stored for 1 month, and a highly significant advantage (p = 0.007) on graft adherence of skin stored for 6 to 10 months. The effect of method and samples variety on the separate histologic criteria and average score of skin is not always significant. However, an interaction factor (between method and samples) has a highly significant effect (p < 0.001) on almost all of the histologic criteria and average skin score. The effects of freezing method is significant only on average skin score, for 1 month of storage; whereas temperature effect is seldom significant. Evaluating the effects of time, samples, and the interaction factor (between time and samples) indicated that the interaction factor is highly significant (p < 0.001). Time and samples effects are rarely significant. Thus the quality of the final product-the cryopreserved skin-is determined by many factors, and quite often they interact. Highly significant is the combined effect, or interaction factor, of sample variability with method of cryopreservation or with storage period.

Animals↗

Silver-sulfadiazine eschar pigmentation mimics invasive wound infection: a case report.

A 3-year-old girl with 52% TBSA scalds, mostly partial thickness, was treated topically with 5% mafenide acetate solution and 1% silver sulfadiazine cream. All blood cultures and wound swabs were negative for the first 5 days. On day 6 gram-negative bacteria and yeast forms were isolated from her wounds. High fever and leukocytosis were present and the child was treated with intravenous ampicillin and gentamicin according to sensitivity bacteriogram. The bacteria were identified as Pseudomonas aeruginosa and the yeast was Candida tropicalis. On day 7, Escherichia coli was identified in blood cultures and intravenous cefixime was added. Amphotericin B was added on day 9 when blood cultures grew Candida tropicalis and Burkholderia cepacia. On day 13 dark pigmentation foci developed on some areas of partial-thickness burns in the back, resembling invasive wound infection. White blood cell count was 14,300 cells/mm3, and her body temperature reached 39.7 degrees C. Cultures from the pigmented areas were negative, and biopsies revealed deposits of silver. Most of the areas healed uneventfully, and only about 8% TBSA needed grafting, including some of the pigmented areas. No residual pigmentation remained on discharge.

Anti-Infective Agents, Local↗

Using bone's adaptation ability to lower the incidence of stress fractures.

In three prospective epidemiologic studies of the effect of pre-military-induction sport activities on the incidence of lower extremity stress fractures during infantry basic training, recruits who played ball sports (principally basketball) regularly for at least 2 years before basic training had a significantly lower incidence of stress fractures (13.2%, 16.7%, and 3.6% in the three studies, respectively) than recruits who did not play ball sports (28.9%, 27%, and 18.8%, respectively). Preinduction running was not related to the incidence of stress fracture. To assess the tibial strain environment during these sport activities, we made in vivo strain measurements on three male volunteers from the research team. Peak tibial compression and tension strain and strain rates during basketball reached levels 2 to 5.5 times higher than during walking and about 10% to 50% higher than during running. The high bone strain and strain rates that occurred in recruits while playing basketball in the years before military induction may have increased their bone stiffness, according to Wolff's Law. The stiffer bone could tolerate higher stresses better, resulting in lower strains for a given activity and a lower incidence of stress fractures during basic training.

Adaptation, Physiological↗

Airborne field hospital in disaster area: lessons from Armenia (1988) and Rwanda (1994).

The outcome of survivors within disaster areas largely depends upon the quick reallocation and operation of logistic and medical support systems. Enthusiastic media equipped with advanced communication systems, reveal mass human suffering in real time. But, the response period required for the organization of rescue systems is much slower and is most frustrating. In this article, we present our experience in quick deployment and operation of airborne field hospitals gained following the earthquake disaster in Armenia in 1988 and the civil war in Rwanda in 1994. Deployment of improvised, volunteer-based, military field hospitals was feasible within 24 hours after the decision was made. A multi-disciplinary structure enabled an effective, flexible mode of operation and reduced the dependency on mericulous, time-consuming assessments of requirements prior to deployment. These missions are a paradigm for the successful incorporation and integration within the capabilities of military infrastructure of volunteer professionals drafted from civil medical facilities. Such field hospitals could provide backup for primary care medical systems in disaster areas and substitute or take some pressure off of local hospitals, particularly when evacuation systems are insufficient.

Aircraft↗