Biomedical subjects

Marc G Jeschke

Publications and source records attributed to Marc G Jeschke.

40 records · Page 3Linked to original sources

PubMedDate not supplied

Acute bronchial obstruction in sheep: histopathology and gland cytokine expression.

An ovine model of smoke inhalation and burn (S+B) injury models the pathophysiology of these injuries in humans. This study examines the degree of airway obstruction, associated histopathology, and bronchial gland cell expression of cytokines during the first 24 hours after S+B injury in sheep. Changes in the mean degree of obstruction were limited to the bronchial airways, showing significant increases in obstruction with time, P<.05. At 4 hours after injury, the obstructive material was predominantly mucus, with neutrophils clustered around and within gland acini. At 8 to 24 hours, bronchial obstruction was characterized by increased inflammatory cell accumulation. Immunohistochemical results showed that gland cells constitutively express and secrete interleukin (IL)-1beta, and that after injury there is an increase in the percentage of gland cells staining for IL-1alpha, IL-8, and tumor necrosis factor (TNF)-alpha, P<.05.

Acute Disease↗

PubMedDate not supplied

Correlation of bronchoalveolar lavage with radiographic evidence of pneumonia in thermally injured children.

The diagnosis of pneumonia in the critically ill patient is very difficult because the usual signs and symptoms are unreliable in the intensive care setting. Bronchoalveolar lavage (BAL) is a diagnostic tool with a reported sensitivity of 70%. The purpose of this study was to determine the efficacy and specificity of BAL in severely burned pediatric patients. An analysis was performed in which BAL cultures were compared and correlated to chest radiographs. Patient characteristics, such as age, sex, burn size, depth of burn, and the presence of inhalation injury were evaluated. Over a period of 18 months, 58 thermally injured children were identified who underwent 101 BALs. The mean age was 6.5 +/- 5 years, mean TBSA was 39 +/- 27%, and inhalation injury was diagnosed in 20 patients (35%). Of 101 BALs, 48 were positive, and of the 101 chest radiographs, 20 demonstrated signs of pneumonia. Ten of those were associated with a positive BAL and 10 with a negative BAL. Thus, the positive predictive value of BAL was 21%, whereas the negative predictive value was 81%. Interestingly 80% of patients with tracheobronchitis from inhalation injury demonstrated a positive BAL. We conclude that in pediatric burn patients BAL correlates poorly with radiographic signs of pneumonia.

Adolescent↗

PubMedDate not supplied

Interaction of exogenous liposomal insulin-like growth factor-I cDNA gene transfer with growth factors on collagen expression in acute wounds.

Growth factors have been shown to modulate the complex cascade of wound healing, however, interaction between different growth factors during dermal and epidermal regeneration is still not entirely defined. We have recently shown that exogenous liposomal gene transfer of cDNA results in physiologic expression and response in an acute wound. In the present study we determined the interaction between insulin-like growth factor-I (IGF-I), a mesenchymal growth factor, administered as liposomal cDNA, with other dermal and epidermal growth factors on collagen synthesis in an acute wound. Sprague-Dawley rats were given a scald burn to inflict an acute wound and divided into two groups to receive weekly subcutaneous injections of liposomes plus a beta-galactosidase containing plasmid (Lac Z [0.2 microg, vehicle]), or liposomes plus the IGF-I cDNA containing plasmid (2.2 microg) and Lac Z (0.2 microg). Immunological assays, histological and immunohistochemical techniques were used to determine growth factor concentration and different types of collagen (I, III, and IV) after IGF-I cDNA gene transfer. IGF-I cDNA transfer accelerated reepithelization and was associated with increased levels of IGF-I, fibroblast growth factor, keratinocyte growth factor, vascular endothelial cell growth factor, and platelet-derived growth factor protein expression. IGF-I cDNA had no effect on transforming growth factor-beta. IGF-I cDNA significantly increased type IV collagen while it had no effect on types I and III collagen. Exogenously administered IGF-I cDNA increased protein concentrations of keratinocyte growth factor, fibroblast growth factor, platelet-derived growth factor, and type IV collagen. We conclude that liposomal IGF-I gene transfer can accelerate wound healing without causing an increase in types I and III collagen expression.

Animals↗

PubMedDate not supplied

Effect of oxidized regenerated cellulose/collagen matrix on dermal and epidermal healing and growth factors in an acute wound.

Rapid healing of acute wounds, e.g., in burned patients, can be essential for survival. Oxidized regenerated cellulose/collagen (ORC/collagen) has been shown to improve wound healing of chronic wounds. The aim of the present study was to determine the effect of ORC/collagen on dermal and epidermal healing as well as growth factor concentration in acute wounds. Rats received a full-thickness excision wound and were treated with either ORC/collagen plus a hydrocolloid dressing or a hydrocolloid dressing alone. Planimetry, immunological assays, histological and immunohistochemical techniques were used to determine dermal and epidermal regeneration, protein concentration, and growth factor concentration. In addition, dermal vascularization and structure were determined. Wounds treated with ORC/collagen showed a significantly faster reepithelization than those treated with hydrocolloid alone, p < 0.05. This accelerated wound healing rate may be explained by significantly higher levels of platelet-derived growth factor, keratinocyte growth factor, insulin-like growth factor-I, and insulin-like growth factor binding protein-3 in the ORC/collagen group leading to antiapoptotic effects of skin cells, p < 0.05. There were no significant differences in collagen morphology or deposition, neo-angiogenesis, or vascular endothelial growth factor concentration between both treatment groups. We conclude that ORC/collagen matrix accelerates epidermal regeneration and locally increases growth factor concentrations. Increased reepithelization was associated with decreased skin cell apoptosis. Based on our data we hypothesize that the ORC/collagen matrix may also have beneficial effects on acute wounds in a clinical setting.

Animals↗