Showing papers by "Ronald G. Tompkins published in 2002"

Inducible nitric oxide synthase plays a role in LPS-induced hyperglycemia and insulin resistance

Abstract: The molecular mechanisms underlying endotoxin-induced insulin resistance remain unclear. Endotoxin or lipopolysaccharide (LPS) injection is a potent stimulator of inducible nitric oxide synthase (i...

Long-term consequences of toxic epidermal necrolysis in children.

Abstract: Objective Toxic epidermal necrolysis (TEN) is an acute inflammatory systemic condition that involves injury not just to the skin Historically, it has been associated with a high mortality but few long-term consequences among survivors With improved survival, long-term consequences may be becoming more apparent The objective of this study was to define these long-term consequences and their frequency Methods From July 1, 1991, to June 30, 2000, 11 children with severe TEN were referred to a regional pediatric burn facility Wounds were managed with a strategy involving prevention of wound desiccation and superinfection, including the frequent use of biological wound coverings All children survived and have been followed in the burn clinic The records of all children were reviewed in detail Results Two boys and 9 girls with an average age of 72 +/- 18 years (range: 6 months-15 years) and sloughed surface area of 76 +/- 6% of the body surface (range: 50%-95%) were admitted to the burn unit for care Antibiotics (3 children), anticonvulsants (4 children), nonsteroidals (2 children), and viral syndrome or unknown agents (2 children) were believed to have triggered the syndrome Six (55%) children required intubation for an average of 97 +/- 18 days (range: 2-14 days) Mucosal involvement occurred in 10 (91%) and ocular involvement in 10 (91%) Lengths of stay averaged 19 +/- 3 days (range: 6-40 days) Overall follow-up averaged 14 +/- 13 months Three children had no apparent long-term consequences of the disease and were referred to primary care follow-up after the 2-month burn clinic visit The remaining children had follow-up averaging 23 +/- 13 months The most common long-term morbidity involved eyes (3 children [27%]), nails (4 children [36%]), and variegated skin depigmentation (all children) One child developed vaginal stenosis from mucosal inflammation No esophageal strictures or recurrent TEN has been diagnosed Conclusions Survival has improved in children with TEN, but long-term sequelae are not infrequent The most common long-term consequences involve the eyes, the skin, and the nails

Use of Integra artificial skin is associated with decreased length of stay for severely injured adult burn survivors.

Abstract: Mortality and length of stay (LOS) of survivors was examined retrospectively in 270 adults with acute burns > or =20% of body surface area to determine the effect of Integra Dermal Regeneration Template treatment on outcome. No difference in mortality was found between patients who received Integra (30%; n = 43) and patients who did not (30%; n = 227). Surviving Integra patients (n = 30) stayed longer, but they were more extensively injured than survivors who did not receive Integra (n = 158), and therefore longer hospitalizations were expected. In a subgroup analysis, mean LOS of Integra patients with two or more mortality risk factors (age > 60 years, burn size >40% body surface area, or inhalation injury; n = 15) was 63 days compared with 107 days in patients with two or more risk factors (n = 29) who did not receive Integra ( =.014). Integra use in severely injured burned adults was associated with a marked decrease in LOS.

The development, validation, and testing of a health outcomes burn questionnaire for infants and children 5 years of age and younger: American Burn Association/Shriners Hospitals for Children.

Abstract: The 12-member American Burn Association/Shriners Hospitals for Children Outcomes Task Force was charged with developing a health outcomes questionnaire for use in children 5 years of age and younger that was clinically based and valid. A 55-item form was tested using a cross-sectional design on the basis of a range of 184 infants and children between 0 and 5 years of age at 8 burn centers, nationally. A total of 131 subjects completed a follow-up health outcomes questionnaire 6 months after the baseline assessment. A comparison group of 285 normal nonburn children was also obtained. Internal consistency reliability of the scales ranged from 0.74 to 0.94. Tests of clinical validity were significant in the hypothesized direction for the majority of scales for length of hospital stay, duration since the burn, percent of body surface area burned, overall clinician assessment of severity of burn injury, and number of comorbidities. The criterion validity of the instrument was supported using the Child Developmental Inventories for Burn Children in early childhood and preschool stages of development comparing normal vs abnormal children. The instrument was sensitive to changes over time following a clinical course observed by physicians in practice. The Health Outcomes Burn Questionnaire for Infants and Children 5 years of age and younger is a clinically based reliable and valid assessment tool that is sensitive to change over time for assessing burn outcomes in this age group.

Bioengineering of liver assist devices

Abstract: Over 30 000 patients die annually in the United States from liver failure. In fulminant hepatic failure, a clinical syndrome associated with high mortality, orthotopic liver transplantation is the primary therapeutic option for patients not responding to supportive therapy. However, the persistent scarcity of donor organs has limited this therapeutic modality, resulting in a continued increase in the number of patients who die waiting for a donor liver. An extracorporeal bioartificial liver device could provide vital support to a liver failure patient until a donor liver was available or until the patient's own liver regenerated. Although it is unclear which liver-specific functions must be provided by such a device to be effective, a constant challenge has been to obtain stable, well-differentiated, and normally functioning hepatocytes that can be cultured at high cell densities. Many of the devices currently undergoing clinical trials are limited by designs which are prone to substrate limitations, resulting in compromised hepatocyte function. In devices that avoid substrate limitations, hepatocyte functions can be optimized, thereby leading to increased device efficiency. In this overview, the authors describe the critical issues involved in bioartificial liver development and discuss their experiences in hepatocyte culture optimization within the context of a microchannel, flat-plate bioartificial liver device with an internal membrane oxygenator.

Plasma L-5-oxoproline kinetics and whole blood glutathione synthesis rates in severely burned adult humans.

Abstract: Compromised glutathione homeostasis is associated with increased morbidity in various disease states. We evaluated the kinetics of l-5-oxoproline, an intermediate in the γ-glutamyl cycle of glutath...

Mapping of local renal blood flow with PET and H(2)(15)O.

Abstract: We developed a noninvasive method for the mapping of regional renal blood flow in humans using PET and H215O. Methods: Fifteen subjects participated in the study, 5 with normal renal function and 10 with renal disease. The protocol used a whole-body PET scanner, intravenous bolus injection of 1,110–1,850 MBq H215O and sequential imaging at 3 s per frame. 131I-Iodohippuran was used to independently assess effective renal plasma flow in each subject. Hippuran clearance and renal blood flow (RBF) were measured twice, before and after treatment with probenecid, to verify that RBF is not affected. Flow analysis was based on the Kety model, according to the operational equation: C(t) = F ∫ Ca(u)du − k ∫ C(u)du, where F is the RBF, k is the tissue-to-blood clearance rate, C is the PET concentration, and Ca is the tracer concentration in the abdominal aorta. F and k were estimated by linear least squares on a pixel-by-pixel basis to produce quantitative maps (parametric images) of RBF. The flow maps were analyzed by regions of interest (largely excluding the medulla and collecting system) for each kidney on each slice and pooled to yield mean RBF. Results: In the 5 healthy subjects, mean RBF was 3.4 ± 0.4 mL/min/g. There was no difference in flow between kidneys (t = −0.59; n = 11; P > 0.95). Before treatment with probenecid, RBF was linearly related to hippuran clearance (r2 = 0.92). Probenecid treatment significantly reduced hippuran clearance (P 0.17). Compared with healthy control subjects, RBF was significantly decreased in patients with renal disease (P

Effectiveness of bacteria-controlled nursing units in preventing cross-colonization with resistant bacteria in severely burned children.

Abstract: Bacteria-controlled nursing units (BCNUs) are laminar air-flow patient isolation units. The rate of cross-colonization with resistant organisms in 66 critically ill pediatric burn patients with massive open wounds and ventilators housed in BCNUs during 5 years was examined and found to be extremely low (3.2 cases per 1,000 patient-days).

Regional measurement of canine skeletal muscle blood flow by positron emission tomography with H2 15O

Abstract: Positron emission tomography (PET) with H2 15O was used as an in vivo, relatively noninvasive, quantitative method for measuring regional blood flow to hindlimb skeletal muscle of anesthetized dogs...

Methods for the prevention or treatment of bacterial and fungal infections

Abstract: The present invention features improved methods for treating, stabilizing, or preventing a bacterial or a fungal infection in a plant or an animal, such as a mammal. In particular, these methods involve the use of a compound, that is controlled by MvfR, and that affects the expression of an MvfR protein or that promotes its modification or inactivation, or a compound produced by P. aeruginosa strain PA14, but not by P. aeruginosa containing an mvfR mutation, in late stationary phase cultures.

Methods for the prevention or treament of bacterial and fungal infections

Abstract: The present invention features improved methods for treating, stabilizing, or preventing a bacterial or a fungal infection in a plant or an animal, such as a mammal. In particular, these methods involve the use of a compound, that is controlled by MvfR, and that affects the expression of an MvfR protein or that promotes its modification or inactivation, or a compound produced by P. aeruginosa strain PA14, but not by P. aeruginosa containing an mvfR mutation, in late stationary phase culture.

In vivo experience with an extracorporeal flat-plate bioartificial liver: demonstration of efficacy in treating fulminant hepatic failure

Abstract: An extracorporeal bioartificial liver (BAL) device has the potential to provide temporary support for patients with fulminant hepatic failure (FHF). The authors developed a flat-plate BAL with an internal membrane oxygenator in which porcine hepatocytes were cultured as a monolayer. The efficacy of this device was tested in an experimental animal model of FHF. Twenty-four hours after cannulation of the left carotid artery and right jugular vein, FHF was induced in rats by administering two intraperitoneal injections of D-galactosamine (GalN) (1.2 g/kg) at a 12 hour interval. The rats were connected to a BAL device 24 hours after the first GalN injection, and underwent extracorporeal perfusion for a duration of 10 hours. Liver-specific markers and animal survival up to 168 hours (7 days) were examined. Significant reductions occurred in the plasma ammonia levels and prothrombin times in the group treated with the seeded BAL device. Animal survival in the group treated with the seeded BAL device was significantly higher (50.0%) than in the control animal group treated with an unseeded BAL device (11.1%). In conclusion, this flat-plate BAL with an internal membrane oxygenator and cultured porcine hepatocytes has yielded encouraging results in the treatment of rats with GalN-induced FHF.