Search PubMed⌕ Search

Biomedical subjects

L D Broemeling

Publications and source records attributed to L D Broemeling.

27 records · Page 2Linked to original sources

In vivo characterization of interleukin-4 as a potential wound healing agent.

Interleukin-4 increases the synthesis of extracellular matrix proteins, including types I and III collagen and fibronectin, by both human and rat fibroblasts. Because fibroblasts are the final common effector cells of most phases of tissue repair, this study set out to investigate the effects of interleukin-4 on the healing of three different types of wounds. Acute excisional and chronic granulating wounds inoculated with Escherichia coli and incisional wounds in streptozotocin-induced diabetic Sprague-Dawley rats were used. Recombinant murine or human interleukin-4 was applied topically to the open wounds at doses of 0.1, 1.0, or 10.0 microg/cm(2)/wound for 5 or 10 days. Incisional wounds received the same doses once-at the time of wounding. The time taken to achieve wound closure or wound breaking strength measurements of wounds was recorded and compared with relevant untreated control groups. Wound contraction was impaired in the presence of bacteria, and this was reversed by all doses of recombinant murine interleukin-4. Recombinant murine interleukin-4 had no effect on the wound closure of noncontaminated wounds; it reduced wound breaking strength in acute excisional wounds, except in a contaminated setting when wounds were treated with 1.0 pg/cm(2)/wound. Recombinant interleukin-4 (1.0 microg) improved breaking strength of both diabetic and normal incisional wounds. The apparent pleiotropic effect of interleukin-4 on wound breaking strength under different wound conditions may be related not only to the activity of the fibroblast but also the ratio of cross-linked collagen/total collagen content of wounds. This study suggests that interleukin-4 may be a useful agent for accelerating closure of wounds, particularly where healing is impaired.

Journal Article↗

Current treatment reduces calories required to maintain weight in pediatric patients with burns.

A previous study indicated that formulas for determining caloric requirements of severely burned children overestimated their needs. This study was undertaken to determine the caloric intake required to maintain weight in patients under 12 years of age with burns over more than 30% total body surface area. The 102 patients studied were divided into two groups according to weight changes. A comparison of the actual caloric intakes of these groups was conducted. Multivariate regression analysis indicated that body surface area in square meters and burn surface were significant predictors of caloric requirements to maintain weight in these patients. It was determined that 1800 kcal was a plausible value for the calories per body surface area. Therefore the regression was formed with 1800 kcal as the multiplier of body surface area, and the multiplier of burn surface area was estimated. The resulting formula provides 1300 kcal/m2 burned, which is 900 kcal/m2 burned less than our previously suggested formula.

Body Surface Area↗

Reperfusion injury in burned rats after delayed fluid resuscitation.

Organ failure from ischemic injury is common in deaths that are due to burn when fluid resuscitation is not performed. Organ perfusion after a delay in resuscitation, however, may induce or even accelerate ischemic organ damage. To study this phenomenon, 40 rats were classified (n = 10) to serve as normal control, burn with no resuscitation, burn with early fluid resuscitation, and burn with delayed resuscitation groups. A modified Walker burn model was used to inflict 50% total body surface area scald burns on the rats. Cellular energy metabolism and tissue water content of several vital organs were measured at 8 hours after burn injury. Adenosine triphosphate, total adenine nucleotides, and energy charge in liver, heart, and kidney tissues were significantly lower (p less than 0.05) with delayed fluid resuscitation compared with early resuscitation. Furthermore, in heart and kidney tissues adenosine triphosphate, total adenine nucleotides, and energy charge were significantly lower in the delayed resuscitation group compared with the group that received no fluid resuscitation. This indicates that heart and kidney tissue are more viable at 8 hours after burn injury, with no fluid resuscitation compared with delayed resuscitation. Water content of lung and muscle tissue were significantly lower (p less than 0.05) in the burn group that received no fluid resuscitation compared with that in early and delayed resuscitation groups. Water content of muscle was significantly greater with delayed resuscitation compared with the early resuscitation group. Results indicate that delayed fluid resuscitation in cases of burn shock may disrupt the cellular energy metabolism in some vital organs and cause skeletal muscle edema.(ABSTRACT TRUNCATED AT 250 WORDS)

Adenine Nucleotides↗

Efficacy of leupeptin, superoxide dismutase, and verapamil in modulating delayed reperfusion damage after burn injury.

Reperfusion damage has been identified as an important factor in multiorgan failure after severe burn injury. We wondered if leupeptin, a protease inhibitor, superoxide dismutase (SOD), a scavenger of free oxygen radicals, or verapamil, a calcium antagonist, would protect the cellular energy metabolism when they were given with fluid resuscitation that was delayed 6 hours after a severe burn injury. Fifty male rats weighing 280 to 300 gm received a 50% third-degree scald burn. Ten of these received fluid resuscitation at 30 minutes and 1 1/2 hours after injury, and 40 received delayed fluid resuscitation at 6 and 7 hours after injury. Thirty of these 40 rats were given leupeptin (n = 10), SOD (n = 10), or verapamil (n = 10). Heart, liver, and kidney tissue samples were obtained 8 hours after injury; adenosine triphosphate, adenosine diphosphate, and adenosine monophosphate were measured; and the energy charge potential was calculated. Tissue water content (TWC) in lung and skeletal muscle was also determined. The adenine nucleotide pool and the energy charge potential in heart, liver, and kidney tissue were all significantly decreased (p < 0.01) in rats receiving delayed fluid resuscitation compared with those receiving early resuscitation. Leupeptin was effective in protecting the heart against reperfusion damage, and verapamil and leupeptin showed some efficacy in protecting kidney tissue. Liver tissue, however, showed no protective response with therapy. TWC was significantly decreased (p < 0.01) in skeletal muscle with SOD treatment, and though all treatments appeared to keep lung water content reduced, none was significant at p < 0.01. We thus conclude that both the decreases in heart and kidney adenine nucleotides and the increase in TWC that are caused by delayed fluid resuscitation can be attenuated with appropriate pharmacologic agents.

Adenine Nucleotides↗

Caloric requirements of patients with burns under one year of age.

Formulas for estimating the caloric requirements of pediatric patients with burns have been suggested. However, the needs of infant patients with burns have not been specifically addressed. This study was undertaken to determine the caloric intake required to maintain weight in patients under 1 year of age who had burns covering more than 25% total body surface area. Thirty patients were studied, and a comparison was made between the actual intake required for weight maintenance and the suggested calorie levels provided by published pediatric caloric formulas. The results indicated that a new formula was needed. Multivariate regression analysis indicated that body surface area and burn surface area were significant predictors of caloric requirements, but body surface area was the more important predictor in this infant population. The equation resulting from the regression provides 2100 kcal/m2 body surface area/day plus 1000 kcal/m2 body surface area burned/day.

Age Factors↗

Comparison of fresh and cryopreserved human sperm attachment to bovine oviduct (uterine tube) epithelial cells in vitro.

Formation of a prefertilization sperm reservoir in mammals is thought to occur via sperm cell attachment to fallopian tube or oviduct epithelial cells (OEC). Recent data suggests that such an interaction also occurs for human sperm in the fallopian tube. We have previously validated an in vitro sperm-OEC coculture system utilizing bovine OEC monolayers to study postejaculatory human sperm physiology. This study was done to evaluate aspects of human sperm attachment to OEC in coculture and to determine if such attachment and subsequent sperm survival differ between fresh and cryopreserved human sperm. In experiment 1, aliquots of fresh (n = 4) or cryopreserved sperm (n = 3) from normospermic donors were placed into coculture with OEC monolayers at dilutions ranging from 2 x 10(5) to 15 x 10(6) sperm per well. Numbers of each type of sperm attaching to OEC at each concentration were determined. In experiment 2, fresh and cryopreserved sperm from the same donors (n = 4) were put into OEC coculture to observe numbers attaching and subsequent survival time for each sperm type. Sperm attachment to OEC occurred in a linear, dose-dependent manner for fresh and cryopreserved sperm in experiment 1, both as a function of total sperm numbers and as a function of numbers of motile sperm applied (R2 > or = 0.79). However, cryopreserved sperm attached to the OEC at a slower rate than fresh (as a function of the average increase in the number of sperm attaching per unit increase in the number of sperm applied; P < 0.05), with an overall lower percentage of the total and motile sperm applied attaching to OEC (P < 0.01) for cryopreserved versus fresh sperm. Fewer cryopreserved sperm also attached to the OEC, as compared with fresh sperm, in experiment 2 (P < 0.05), even after correcting for motility differences between the sperm types. Sperm survival time in coculture was also decreased for cryopreserved sperm as compared with fresh sperm (P = 0.005). Understanding the kinetics of sperm and OEC interactions may be useful for developing improved cryopreservation protocols or bioassays of sperm function.

Animals↗

A simplified method to quantify isoflavones in commercial soybean diets and human urine after legume consumption.

Reliable and economical quantification of micronutrients in diets and human is a critical component of successful epidemiological studies to establish relationships between dietary constituents and chronic disease. Legumes are one of the major dietary components consumed by populations worldwide. Consumption of legumes is thought to play a major role in lowering breast and prostate cancer risk. In this study, a simplified method that uses solid-phase extraction and gas chromatography was developed to measure isoflavones at levels down to 10 micrograms/5ml. With the use of this method, 12.5 g miso (a soybean paste), 12 ounces Isomil, and 12 ounces soymilk had daidzin/daidzein levels of 2, 5, and 12.4 mg, respectively, and genistin/genistein levels of 3, 6.5, and 13.7 mg, respectively. In these products, most of the isoflavones were present as glucosides. With the same method, urinary levels of isoflavones in six 15-17-year-old subjects were determined after soymilk ingestion. Each subject was placed on unrestricted nonsoya diets, and three 12-ounce portions of soymilk were given at 12-h intervals. Males excreted 15.02 +/- 2.74 (SD) mg of daidzein glucuronides/sulfates [mean recovery, 40.4 +/- 7.4% (SD)] by 24 h after the third soymilk ingestion, whereas females excreted 25.56 +/- 5.10 mg (68.7 +/- 13.7%) of daidzein conjugates, which was more than males (P = 0.02). Males and females excreted 7.73 +/- 1.95 mg and 9.11 +/- 0.84 mg of genistein glucuronides/sulfates (20% recovery of genistin intake), respectively, in the urine. Most of the isoflavones were excreted within 24 h after ingestion.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗