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Biomedical subjects

O Frenkel

Publications and source records attributed to O Frenkel.

5 recordsLinked to original sources
PubMed2004

Macrophage suspensions prepared from a blood unit for treatment of refractory human ulcers.

This paper presents an innovative method for the treatment of refractory wounds, starting with a blood unit, that is based on a biological approach. Local wound repair is one of the major unresolved clinical problems. Age, infection, clinical conditions such as diabetes mellitus, cardiac, renal, lung and liver failure, malnutrition and immunological deficiencies are among the reasons for wound repair delay or failure. Many chronic ulcers resist conventional treatment and do not heal for months and years, thus causing substantial morbidity and even mortality. The method for macrophage suspension treatment consists of introducing into the wound live cells that play a major role in the process of wound healing. The suspension is prepared from a blood unit of a healthy donor in a cost-effective, closed, sterile system. In the process of preparation, the macrophages are activated by hypo-osmotic shock to enhance their various functions in wound repair. The cells are applied to the wound either by local injection or by direct deposition into the wound. In most cases (90%), only one treatment is sufficient. Since 1995, macrophage suspensions have been used successfully in more than 1000 patients in several hospitals in Israel, without any side effects. Our results show that the use of a macrophage suspension is a safe and effective therapeutic strategy that shortens the healing period, reduces risk of complications and morbidity and improves the quality of life for long-suffering patients. This treatment requires no hospitalization and can be given on an ambulatory basis.

Adolescent↗
PubMed2002

Activated macrophages for treating skin ulceration: gene expression in human monocytes after hypo-osmotic shock.

Macrophages play a major role in almost all stages of the complex process of wound healing. It has been previously shown that the incorporation of a hypo-osmotic shock step, in the process of monocyte-concentrate preparation from a blood unit, induces monocyte/macrophage activation. As the macrophages are produced using a unique, closed and sterile system, they are suitable for local application on ulcers in elderly and paraplegic patients. Enhanced phagocytosis by the activated cells, as well as increased secretion of cytokines such as IL-1, IL-6, were detected in a recent study which are in accord with the very encouraging clinical results. In the present study, we used DNA microarrays to analyse the differential gene expressions of the hypo-osmotic shock-activated monocytes/macrophages and compare them to non-treated cells. Of the genes that exhibited differences of expression in the activated cell population, 94% (68/72) displayed increased activity. The mRNA levels of 43/68 of these genes (63%) were found to be 1.5-fold or higher (1.5-7.98) in the activated macrophages cell population as compared to the non-treated cells. Only four genes were found to have lower mRNA levels in the activated cells, with ratios of expression of 0.62-0.8, which may suggest that the changes are insignificant. A significant number of the genes that showed increased levels of expression is known to be directly involved in macrophage function and wound healing. This may correlate with the increased secretion of different cytokines by the activated macrophages depicted previously. Other groups of genes expressed are known to be involved in important pathways such as neuronal growth and function, developmental defects and cancer. The hypo-osmotic shock induces a gene expression profile of cytokines and receptors in the activated cells. These may evoke potential abilities to produce a variety of protein products needed in the wound healing process and may bring to light possibilities for other therapeutic applications of these cells.

Cell Culture Techniques↗
PubMed2001

Activation of human monocytes/macrophages by hypo-osmotic shock.

Phagocytosis and secretion of interleukins and growth factors put the macrophage in the centre of the wound healing process. For the last four years over 400 human ulcers have been treated in elderly and paraplegic patients by local application of monocytes prepared from a blood unit, in a unique, closed, sterile system. The process of preparation includes a step of hypo-osmotic shock, which induces monocyte/macrophage activation. This is different from any other known method of activation. In the present study we evaluated the efficacy of the hypo-osmotic shock. We found enhanced levels of IL-1 (P = 0.004) and IL-6 (P = 0.001) in the incubation medium (100% autologous serum) of the activated cells, as compared with controls, prepared in the same system. The IL-1 reached a plateau after 6 and 12 h incubation at 37 degrees C, in both experimental and control incubation medium. The level of IL-6 was further elevated after 12 and 24 h incubation in experimental and control incubation mediums (P = 0.001). The phagocytosis of fluorescent beads was markedly enhanced after hypo-osmotic shock (P = 0.005). The osmotic shock induced macrophages were compared to those stimulated with LPS, and osmotic shock was proved to be at least as efficient method of stimulation as LPS.

Culture Media, Conditioned↗