agar and Burns

The subject to assessment were hydrogel dressings (in 42 patients) compared with the classical gauze dressing with an addition of various pharmaceuticals (in 65 patients). We found out that the gauze dressings get dry 24 hours after they have been applied, their replacement being very painful. The hydrogel dressings, on the other hand, do not cause any pain when replaced after the 24 hours. The hygroscopic properties of hydrogel dressings allow a quick cleaning of the wound from microorganisms. Permitting an easy absorption of antibiotics and other drugs, they contribute to an acceleration of the healing process and epidermis development.

Topics: Acrylamides; Acrylic Resins; Adult; Agar; Anti-Bacterial Agents; Bacterial Infections; Burns; Child; Humans; Hydrogel, Polyethylene Glycol Dimethacrylate; Occlusive Dressings; Poland; Polyethylene Glycols; Time Factors; Wound Healing; Wound Infection

Full-thickness burns pose a major challenge for clinicians to handle because of their restricted self-healing ability. Even though several approaches have been implemented for repairing these burnt skin tissue defects, all of them had unsatisfactory outcomes. Moreover, during recent years, skin tissue engineering techniques have emerged as a promising approach to improve skin tissue regeneration and overcome the shortcomings of the traditional approaches. Although previous literatures report the wound healing effects of the squalene oil, in the current study, for the first time, we developed a squalene-loaded emulgel-based scaffold as a novel approach for potential skin regeneration. This squalene-loaded agar-based emulgel scaffold was fabricated by using physical cross-linking technique using lecithin as an emulsifier. Characterization studies such as X-ray diffraction, Fourier-transform infrared spectroscopy, and field emission scanning electron microscopy revealed the amorphous nature, chemical interactions, and cross-linked capabilities of the developed emulgel scaffold. The squalene-loaded emulgel scaffold showed excellent wound contraction when compared with the agar gel and negative control. In case of the histopathology and recent immunohistochemistry findings, it was clearly evidenced that squalene-loaded emulgel promoted faster rate of the revascularization and macrophage polarization in order to enhance the burn wound healing. Moreover, the findings also revealed that the incorporation of squalene oil into the formulation enhances collagen deposition and accelerates the burnt skin tissue regeneration process. Finally, we conclude that the squalene-loaded emulgel scaffold could be an effective formulation used in the treatment of the burnt skin tissue defects.

Topics: Agar; Burns; Humans; Skin; Squalene; Tissue Scaffolds; Wound Healing

Cooled Balloon Prevents Thermal Injury During RF Ablation.. The use of a cooled intraesophageal balloon has recently been proposed to minimize the risk of thermal injury in the esophagus during radiofrequency (RF) ablation of the left atrium. However, the capacity of this device to adequately protect the esophagus under different procedural and anatomical conditions remains unknown.. An agar phantom-based model was built that provided temperature readings not only on the cooled balloon (T(b)) but also at a hypothetical point between the esophageal lumen and myocardium at a distance of 2 mm (T(2-mm)). The RF ablations were conducted considering two anatomical factors (total distance between the electrode and balloon and flow rate around the electrode) and two procedural factors (angle and pressure between the electrode and agar surface). The results show that most of the parameters studied have no significant influence on the temperature measured on the cooled balloon (T(b)), the exception being a variation in the flow rate, which was found to influence the temperature. On the other hand, T(2-mm) was affected to a great extent by all the factors considered, the smallest influence being that of the contact pressure. The results also suggest that when an intraesophageal balloon is employed, the applied power is not a good predictor either of the temperature on the balloon or of the temperature measured at a distance 2 mm away.. The results suggest that a cooled intraesophageal balloon provides effective thermal protection of the esophageal lumen. However, under certain circumstances, the temperature reached at a distance 2 mm away could possibly put at risk the integrity of the inner layers of the esophagus.

Topics: Agar; Burns; Cardiac Catheterization; Catheter Ablation; Catheterization; Esophagus; Humans; Hypothermia, Induced; Phantoms, Imaging; Reproducibility of Results; Sensitivity and Specificity

Topics: Agar; Atrial Fibrillation; Burns; Cardiac Catheterization; Catheter Ablation; Catheterization; Esophagus; Heart Injuries; Humans; Hypothermia, Induced; Phantoms, Imaging; Reproducibility of Results; Sensitivity and Specificity

Human skin allografts are important in the treatment of severe burns. Transplantation of skin allografts can cause bacterial transmission. Glycerol in higher concentrations is an appropriate storage medium for allograft cadaver skin and has been attributed an antimicrobial effect. We investigated this effect in more detail. First, the minimal inhibitory concentration of glycerol was determined for 13 bacteria and 1 yeast. This gives an indication about an immediate (20h of incubation) antibacterial effect of glycerol. Second, effect of glycerol in the long-term was studied. Therefore, the survival time was determined for 11 different bacteria suspended in different concentrations of glycerol (50% and 85%) and incubated at three temperatures (4, 24, and 36 degrees C). The minimal inhibitory concentration exceeded 256microg/mL, thus glycerol had no direct inhibitory effect. In contrast, a long-term antimicrobial effect was present and more pronounced at higher concentrations of glycerol and higher temperatures of incubation. The mean survival time of Pseudomonas aeruginosa strains in glycerol 85% at 24 degrees C was 2.6 days, 14.7 days for the tested staphylococci and 29.6 days for three vegetative Bacillus species. In conclusion, microbial safety of glycerol-preserved skin can be increased by preserving skin allografts for some weeks at room temperature.

Topics: Agar; Anti-Infective Agents; Bacteria; Burns; Glycerol; Humans; Microbial Viability; Skin; Skin Transplantation; Temperature; Time Factors; Tissue Preservation; Transplantation, Homologous

The important requirements of a skin substitute such as water vapour permeability, adherence to the excised wound surface, oxygen permeability, mechanical properties, impermeability to micro-organisms and exudate soaking capacity have been highlighted. Two commercial synthetic skin substitutes, Bioclusive and Geliperm, have been used to establish the preclinical assessment procedures for skin substitutes. Two in vitro techniques, the 'Water Cup' and the 'Inverted Cup,' and two in vivo methods involving a 'Ventilated Hygrometer Chamber' system and an Evaporimeter have been employed to assess and compare the water vapour permeability of the skin substitutes under controlled conditions. An Evaporimeter, which is very simple to operate, provides more accurate results. A simple test has been designed to evaluate the early adherence of the skin substitutes to the excised wound surface of rats. The pulling force and the peeling force required to remove the membrane from the wound surface have been measured and these forces have been found to depend upon the composition of the membrane. An oxygen permeability cell has been fabricated which measures the dissolved oxygen permeability of the skin substitutes. The detection of oxygen is based on the electrocatalytic reduction of oxygen at the surface of a noble metal. The tensile properties of the skin substitutes have been measured by an International Standard procedure and both the skin prostheses are associated with some drawbacks. An in vitro method of testing the microbial permeability of the skin substitutes has been designed which simulates an oozing colonized wound that a skin substitute faces in cases of septicaemia. Both the test materials were impermeable to both bacteria and fungi and will provide an effective barrier. The effectiveness of the skin substitutes to absorb wound exudate from the wound surface has been evaluated by soaking the pieces of the membranes in water, plasma and serum and observing their weight gain. The soaking capacity depends upon the composition and nature of the material. The procedures developed have been employed to evaluate a hydrogel type synthetic skin substitute recently formulated in our laboratory.

Topics: Acrylamides; Agar; Animals; Burns; Disease Models, Animal; Evaluation Studies as Topic; Permeability; Prostheses and Implants; Rats; Rats, Inbred Strains; Skin; Water Loss, Insensible; Wound Healing

A new hydrogel-type skin substitute (HSS) has been investigated for its effectiveness in the management of excised wounds in rats and compared with Geliperm and Bioclusive and air-exposed control. Wound repair has been assessed by measuring the wound size and by histological examination. The effectiveness of the skin substitutes on the re-establishment of the cutaneous barrier to evaporative water loss (EWL) has also been examined by an Evaporimeter. When compared with Geliperm and Bioclusive, a faster rate of wound healing with complete epithelialization was observed under HSS. A significant improvement in the rate of restoration of the barrier functions was observed between the HSS-covered wounds and uncovered controls. A biphasic behaviour of EWL, with an initial rise followed by an exponential decline, was observed in uncovered control and wounds covered with Geliperm and HSS. In the case of Bioclusive, the decline in EWL was less pronounced.

Topics: Acrylamides; Agar; Animals; Artificial Organs; Burns; Evaluation Studies as Topic; Hydrogel, Polyethylene Glycol Dimethacrylate; Occlusive Dressings; Polyethylene Glycols; Rats; Rats, Inbred Strains; Skin; Water Loss, Insensible; Wound Healing

A prospective analysis of 370 burn wound biopsies was done to correlate Gram-stain results from biopsy homogenates with quantitative culture results. The number of bacteria seen in a total of 10 oil immersion microscope fields of Gram-stained homogenates was correlated with significant microbial growth (1 x 10(5) organisms/gram of tissue) of the same biopsy homogenate plated on trypticase soy agar. Of the biopsies examined, Gram-negative rods were present in 36.8 per cent, Gram-positive cocci in 49.7 per cent and yeast in 15.9 per cent. Mixtures of organisms were present in 24.3 per cent. When Gram stains showed one or more organisms per oil immersion microscope field, the correlation with significant microbial growth was 94.5 per cent or more. When five or more organisms were seen per field, the correlation with significant growth became 97 per cent or greater. When no organism was seen on Gram stain, the cultures grew significant numbers of organisms 19.1 per cent of the time or less. This false-negative rate was considered to be high. It is believed, however, that this method of early detection of significant burn wound microbial growth may prove to be valuable in the management of severely burned patients.

Topics: Agar; Biopsy; Burns; Gram-Negative Bacteria; Gram-Positive Bacteria; Humans; Prospective Studies; Staining and Labeling; Time Factors; Wound Infection; Yeasts

Three hydrogels were assessed in respect of water-vapour transmission and conformability. These materials were tested alone and as part of a bilaminate dressing which incorporates an adhesive top layer. The adhesive layer used in this study was a compliant adhesive bandage, marketed under the name Mefix. It was observed that this layer reduced the normally high water-vapour transmission rates of the hydrogels to much lower, clinically more acceptable, levels. Mechanically, the Mefix layer protects the underlying hydrogel, prevents tearing and puncturing but decreases conformability by elastic restraint.

Topics: Acrylamides; Agar; Bandages; Burns; Gels; Humans; Occlusive Dressings; Permeability

Geliperm is a synthetic skin substitute, consisting of polysaccharid-polyacrylic plates. It is available as a soaked or a dried form (Geliperm dry). Geliperm dry can be soaked in antibiotic or antiseptic solutions. The in vitro inhibition of bacterial growth has been measured. The optimal concentrations have been evaluated. Geliperm dry soaked in antibiotic or antiseptic solutions can be used in the treatment of burns, but does not replace early excision of burned tissue or infected necrosis.

Topics: Acrylamides; Acrylates; Agar; Anti-Bacterial Agents; Anti-Infective Agents, Local; Bacteriological Techniques; Burns; Humans; Polysaccharides; Wound Infection

Topics: Acrylates; Agar; Bandages; Burns; Gels; Humans

Three media, phenylethyl alcohol blood agar, esculin-mannitol agar, and Columbia CN blood agar, were studied for the selective isolation of gram-positive bacteria from swab cultures of burn wounds.

Topics: Aerobiosis; Agar; Alcohols; Bacteria; Bacteriological Techniques; Benzene Derivatives; Blood; Burns; Corynebacterium; Culture Media; Cyanides; Evaluation Studies as Topic; Flavonoids; Humans; Mannitol; Staphylococcus; Streptococcus; Yeasts

Six media were evaluated to determine their ability to isolate yeasts and inhibit bacteria. The media included the following: Snyder, Snyder tellurite, Sabouraud tellurite, Littman-gentamicin, molybdate, and Mycosel (BBL). Doses of mixed intestinal gram-negative bacilli and enterococci were most effectively inhibited by Snyder tellurite agar. Klebsiella pneumoniae was the most common bacterial contaminant of the other media. All six media were comparable in isolating yeasts while preventing the growth of the oral bacterial flora. The selection of a basal fungal growth medium for tellurite incorporation to inhibit bacteria but permit growth of yeasts was affected by pH. The bacteriostatic effect of tellurite was decreased with increasing pH of media while fungistatic action was increased. The arbitrary selection of Snyder and Littman agars to isolate yeast from burn wound cultures demonstrated the need to include a selective medium for these specimens. Blood, phenylethyl alcohol blood agar, and Columbia CN blood agar were all inadequate for isolating yeasts from burns. Growth of a variety of filamentous saprophytic and pathogenic dimorphic fungi grew adequately on four of five selective media tested.

Topics: Adult; Agar; Bacteria; Burns; Candida; Candida albicans; Child, Preschool; Culture Media; Evaluation Studies as Topic; Fungi; Gentamicins; Humans; Hydrogen-Ion Concentration; Klebsiella pneumoniae; Molybdenum; Mouth; Rectum; Species Specificity; Tellurium; Yeasts

Topics: Agar; Animals; Burns; Electrophoresis; Gels; Isoenzymes; L-Lactate Dehydrogenase; Male; Photometry; Rats; Skin; Time Factors

Topics: Agar; Animals; Antifungal Agents; Burns; Candida albicans; Dialysis; Escherichia coli; Gentamicins; Germ-Free Life; In Vitro Techniques; Intestines; Mice; Mice, Inbred ICR

Topics: Agar; Air Microbiology; Bacteriological Techniques; Blood; Burns; Child; Culture Media; Deoxyribonucleases; Evaluation Studies as Topic; Hospital Departments; Humans; Mannitol; Micrococcus; Rosaniline Dyes; Staphylococcus

Topics: Agar; Anti-Infective Agents, Local; Burns; Culture Media; Evaluation Studies as Topic; Humans; Meat; Nalidixic Acid; Pseudomonas aeruginosa; Quaternary Ammonium Compounds

Acetamide broth, used in conjunction with ultraviolet light scanning, was superior to Pseudosel agar in the recovery of Pseudomonas aeruginosa from rectal swabs both in time of recognition and total positive isolations.

Topics: Acetamides; Agar; Bacteriological Techniques; Burns; Child; Culture Media; Evaluation Studies as Topic; Humans; Pseudomonas aeruginosa; Rectum; Specimen Handling; Ultraviolet Rays

Topics: Agar; Burns; Cross Infection; Drug Resistance; Enterobacteriaceae; Gentamicins; Humans; Pseudomonas aeruginosa; Pseudomonas Infections

Topics: Agar; Animals; Autoantibodies; Burns; Cricetinae; Guinea Pigs; Humans; Kidney; Liver; Lung; Mice; Myocardium; Passive Cutaneous Anaphylaxis; Precipitin Tests; Rabbits; Rats; Skin; Spleen