Efficacy of Mepliex® Ag Versus Xeroform® As A Split-Thickness Skin Graft Donor Site Dressing: Bad Habits Die Hard

Autografting with split-thickness skin grafts (STSG) remains an essential procedure in burn and reconstructive surgery. The process of harvesting STSG, however, leaves behind a donor site, an exposed area of partial-thickness dermis left to heal by secondary intention. There has yet to be a consensus amongst surgeons regarding optimal management of the donor site. The ideal donor site dressing is one that allows for expeditious healing while minimizing pain and infection. Despite numerous studies demonstrating the superiority of moist wound healing, many surgeons continue to treat STSG donor sites dry, with petroleum-based gauze. In this study, two burn centers performed a retrospective review of burn patients whose STSG donor sites were treated with either Xeroform® or Mepilex® Ag dressings. Infections were documented and in a subgroup analysis of patients, postoperative pain scores were noted and total opiate usage during hospitalization was calculated. Analysis revealed an overall infection rate of 1.2% in the Mepilex® Ag group and 11.4% in the Xeroform® group (p<0.0001). Patients with Xeroform® donor site dressings had increased odds of donor site infection (OR=10.8, p=0.002). In subgroup analysis, there were no significant differences in maximum pain scores between Mepilex® Ag and Xeroform® groups, nor were there differences in opiate usage. STSG donor sites dressed with silver foam dressings have a lower rate of donor site infection relative to those dressed with petroleum-based gauze. Moist donor site dressings such as foam dressings (including Mepilex® Ag) should be the standard of care in STSG donor site wound care.

Metabolism and epigenetics of pancreatic cancer stem cells

Pancreatic Cancer (PDA) is an aggressive malignancy characterized by early spread and a high mortality. Current studies suggest that a subpopulation of cells exist within tumors, cancer stem cell (CSC), which are capable of self-renewal and give rise to unique progeny which form the major neoplastic cellular component of tumors. While CSCs constitute a small cellular subpopulation within the tumor, their resistance to chemotherapy and radiation make them an important therapeutic target for eradication. Along with distinctive phenotypic properties, CSCs possess a unique metabolic plasticity allowing them to rapidly respond and adapt to environmental changes. These cells and their progeny also display a significantly altered epigenetic state with distinctive patterns of DNA methylation. Several mechanisms of cross-talk between epigenetic and metabolic pathways in PDA exist which ultimately contribute to the observed cellular plasticity and enhanced tumorigenesis. In this review we discuss various examples of this metabolic-epigenetic interplay and how it may constitute a new avenue for therapy specifically targeting CSCs in PDA.

PGE2 suppresses NK activity in vivo directly and through adrenal hormones: effects that cannot be reflected by ex vivo assessment of NK cytotoxicity

Surgery can suppress in vivo levels of NK cell cytotoxicity (NKCC) through various mechanisms, including catecholamine-, glucocorticoid (CORT)-, and prostaglandin (PG)-mediated responses. However, PGs are synthesized locally following tissue damage, driving proinflammatory and CORT responses, while their systemic levels are often unaffected. Thus, we herein studied the role of adrenal factors in mediating in vivo effects of PGs on NKCC, using adrenalectomized and sham-operated F344 rats subjected to surgery or PGE(2) administration. In vivo and ex vivo approaches were employed, based on intravenous administration of the NK-sensitive MADB106 tumor line, and based on ex vivo assessment of YAC-1 and MADB106 target-line lysis. Additionally, in vitro studies assessed the kinetics of the impact of epinephrine, CORT, and PGE(2) on NKCC. The results indicated that suppression of NKCC by epinephrine and PGE(2) are short lasting, and cannot be evident when these compounds are removed from the in vitro assay milieu, or in the context of ex vivo assessment of NKCC. In contrast, the effects of CORT are long-lasting and are reflected in both conditions even after its removal. Marginating-pulmonary NKCC was less susceptible to suppression than circulating NKCC, when tested against the xenogeneic YAC-1 target line, but not against the syngeneic MADB106 line, which seems to involve different cytotoxicity mechanisms. Overall, these findings indicate that elevated systemic PG levels can directly suppress NKCC in vivo, but following laparotomy adrenal hormones mediate most of the effects of endogenously-released PGs. Additionally, the ex vivo approach seems limited in reflecting the short-lasting NK-suppressive effects of catecholamines and PGs.

Fructose triggers DNA modification and damage in an Escherichia coli plasmid

The nonenzymatic reaction between reducing sugars and amino groups of long-lived macromolecules results in an array of chemical modifications that may account for several physiological complications. The characteristics of the reaction are directly related to the type of the reducing sugars involved, whether aldoses or ketoses, phosphorylated or non-phosphorylated, and these in turn determine the consequences of the induced modifications. So far, most studies have been focused on the nonenzymatic reaction between glucose and proteins, while the reaction with fructose, a faster glycating agent, attracted only a minor attention. We have recently demonstrated that long-term fructose consumption induces age-related changes in collagen from skin and cortical bones faster than glucose. In the present study we provide evidence that fructose and its phosphate metabolites can modify DNA faster than glucose and its phosphate metabolites under in vitro conditions. Incubating the plasmid pBR322 with fructose and glucose phosphate metabolites induced DNA modifications and damage that were verified by gel electrophoresis and transformation capacity of the plasmid into an Escherichia coli host. The intensity of the tested sugars to modified and damage DNA after incubation for 15 days increased significantly in the following order: glucose 1-phosphate < glucose < glucose 6-phosphate < fructose 1-phosphate < fructose < fructose 6-phosphate. The data suggest that fructose should deserve more attention as a factor that may influence glycation and induce physiological complications.

Modulation of macrophage recruitment into wounds by monocyte chemoattractant protein-1

Previous studies suggest that normal wound repair requires the regulated production of monocyte and macrophage chemoattractants. The current study examines the role of monocyte chemoattractant protein-1 (MCP-1) in coordinating monocyte recruitment into sites of injury. MCP-1 protein was detected in both incisional and excisional murine wounds, with a peak concentration occurring slightly before maximum macrophage infiltration. Compared to wounds treated with control antibody, wounds treated with a neutralizing monoclonal anti-MCP-1 antibody contained significantly fewer macrophages (8.2 +/- 0.9 vs. 14 +/- 1.7 macrophages per high power field, p < 0.05). Conversely, the addition of recombinant MCP-1 to wounds resulted in a substantial increase in the number of macrophages (107% to 124% increase over untreated wounds, p < 0.01). Because macrophages promote wound healing, the effect of recombinant MCP-1 on the wound healing process was examined. Incisional wounds (n = 12) were either left untreated or treated with vehicle alone, 5 ng recombinant MCP-1 in vehicle, or 50 ng recombinant MCP-1 in vehicle. Wound disruption strength was determined on days 7, 14, 21, and 28 for each group. Wounds treated with MCP-1 exhibited a slight increase in wound disruption strength at nearly all time points but this increase did not reach statistical significance. Addition of 100 ng of MCP-1 to excisional wounds did not have any significant effect on wound reepithelialization. Taken together, the results show that MCP-1 is produced within wounds at physiologic concentrations, and is an important positive regulator of macrophage recruitment into sites of injury. Addition of exogenous MCP-1 to wounds of normal mice yields only modest enhancement of the repair process.

Long-term fructose consumption accelerates glycation and several age-related variables in male rats

Fructose intake has increased steadily during the past two decades. Fructose, like other reducing sugars, can react with proteins through the Maillard reaction (glycation), which may account for several complications of diabetes mellitus and accelerating aging. In this study, we evaluated the effect of fructose intake on some age-related variables. Rats were fed for 1 y a commercial nonpurified diet, and had free access to water or 250 g/L solutions of fructose, glucose or sucrose. Early glycation products were evaluated by blood glycated hemoglobin and fructosamine concentrations. Lipid peroxidation was estimated by urine thiobarbituric reactive substances. Skin collagen crosslinking was evaluated by solubilization in natural salt or diluted acetic acid solutions, and by the ratio between beta- and alpha-collagen chains. Advanced glycation end products were evaluated by collagen-linked fluorescence in bones. The ratio between type-III and type-I collagens served as an aging variable and was measured in denatured skin collagen. The tested sugars had no effect on plasma glucose concentrations. Blood fructose, cholesterol, fructosamine and glycated hemoglobin levels, and urine lipid peroxidation products were significantly higher in fructose-fed rats compared with the other sugar-fed and control rats. Acid-soluble collagen and the type-III to type-I ratio were significantly lower, whereas insoluble collagen, the beta to alpha ratio and collagen-bound fluorescence at 335/385 nm (excitation/emission) were significantly higher in fructose-fed rats than in the other groups. The data suggest that long-term fructose consumption induces adverse effects on aging; further studies are required to clarify the precise role of fructose in the aging process.

Medicoritual trephinations in modern Israel

Two recent cases of ritual trephinations that were revealed during regular autopsies are described. The osteologic findings are discussed in relation to hospital craniotomy and ancient trephination, and the forensic practitioner is offered a set of criteria to differentiate properly between trephination and craniotomy.

Delayed shotgun pellet migration to the right ventricle

Multiple case reports of bullet emboli to the heart have been documented. A unique clinical situation is presented of a patient who sustained a shotgun injury to the buttock, with retained pellets, who 7 to 10 years later demonstrated intravascular migration of one of the pellets to the intracardiac position.

Repeat treadmill exercise testing: variability of results in patients with angina pectoris

To assess the reproducibility and individual variability of ECG treadmill exercise test results, we evaluated 23 patients with coronary artery disease and stable exertional angina by means of two control exercise tests performed on different days within a 1 week period. In addition, each control test was followed on the same day by a single dose of placebo or active agent determined in a randomized double-blind manner and the exercise test was repeated. When the mean exercise test results from the control tests on days 1 and 2 were compared, there was a significant increase in exercise duration to angina (7.4 +/- 3.2 to 9.0 +/- 3.3 minutes, p less than 0.05), ST segment depression (7.8 +/- 3.9 to 9.6 +/- 3.6 minutes, p less than 0.01), and maximal exercise (9.7 +/- 3.7 to 11.0 +/- 4.1 minutes, p less than 0.01). In addition, when the mean exercise results on the control test were compared to those on the postplacebo test on the same day, similar increases in exercise duration were observed at each end point (p less than 0.01). Individual differences of more than 2 minutes in exercise duration between the two control tests and between the control and postplacebo tests in time to angina, ST segment depression, and maximal exercise were frequent (26% to 33% of patients). However, the mean rate-pressure products on the two control tests performed on days 1 and 2 and on the control and postplacebo tests performed on the same day did not differ at angina, ST segment depression, and maximal exercise.(ABSTRACT TRUNCATED AT 250 WORDS)