The relationship between interferon-gamma and keratinocyte alloantigen expression after burn injury

BACKGROUND

Cultured keratinocyte (CK) and cadaveric skin allografts have prolonged survival in patients with massive thermal injury. It is unclear if this delayed rejection is due to impaired host responsiveness or decreased graft immunogenicity. Although burn injury has been shown to decrease parameters of allograft response, no studies have examined the effect of burn injury on alloantigen expression. This study investigated the effect of burn size on class II antigen expression in CK allografts as well as on tissue levels of interferon-gamma (IFN-gamma), the principle regulator of alloantigen expression.

METHODS

Anesthetized CBA mice (n = 64) received a 0%, 20% partial-thickness (PT), 20% full-thickness (FT), or 40% FT contact burn. Forty-eight hours later, wounds were partially excised and covered with CK allografts from C57BL/6 donors. Five days after burn injury, grafts were analyzed for donor-specific class II antigen. Protein expression was determined by Western immunoblotting and quantified with video densitometry. Wound, serum, and unburned skin levels of IFN-gamma were determined by enzyme-linked immunosorbent assay. Groups were compared by Fisher's analysis of variance.

RESULTS

As burn size increased, class II antigen expression decreased (p < 0.001). This corresponded with decreased wound and skin levels of IFN-gamma after 40% burn (p < 0.05); however, wound IFN-gamma was significantly elevated after 20% PT and FT burns (p < 0.01). Serum IFN-gamma increased as burn size increased (p < 0.01).

CONCLUSIONS

Burn injury decreases the antigenicity of CK allografts, which partly explains delayed allograft rejection after burn injury. Although wound IFN-gamma increases after minor thermal injury, the profound decrease in wound and skin IFN-gamma after a major burn corresponds with diminished class II antigen expression. The decreased availability of IFN-gamma after major thermal injury provides a mechanism for limited allograft tolerance.

Cortical bone perfusion in plated fractured sheep tibiae

The limited contact dynamic compression plate and partial contact plate were designed to decrease contact with cortical bone in an attempt to decrease cortical ischemia, remodeling, and eventual porosis under the plate after use of standard dynamic compression plates. This study quantified cortical bone blood flow beneath the plate with these three different designs in a sheep tibia fracture model. In 18 skeletally immature sheep, the right tibia was fractured and then was internally fixed with an interfragmentary screw and a dynamic compression plate, limited contact dynamic compression plate, or partial contact plate. At 12 weeks, cortical bone perfusion was assessed with laser Doppler flowmetry in nine areas beneath the plate. The baseline (before fracture) cortical bone cell flux averaged 100 +/- 60 mV. After fracture, this decreased to 60 +/- 48 mV (p < 0.0003); immediately after plating, the perfusion averaged 29 +/- 25 mV (p < 0.01). Cortical bone perfusion then increased to 106 +/- 52, 165 +/- 71, and 163 +/- 71 mV at 2, 6, and 12 weeks after fracture (p < 0.001 for all when compared with values after plating). No significant differences in cortical perfusion were seen between the types of plate. Cortical porosity under the plate was assessed with digital density analysis of microradiographs of this region. No significant difference was seen between the types of plate in this analysis or in biomechanical and disulphine blue perfusion analysis. Thus, no significant advantage was seen for the new plate designs used in this model. This lack of advantage may be a result of the immature animals used in the study, the protocol for blood flow measurement, the invasive periosteal stripping employed to create the fracture, or all three. However, as advantages with the new plate designs have been seen in other studies, this area warrants further investigation.

Are PRO discharge screens associated with postdischarge adverse outcomes?

OBJECTIVE

We evaluate whether patient outcomes may be affected by possible errors in care at discharge as assessed by Peer Review Organizations (PROs).

DATA SOURCES/STUDY SETTING

The three data sources for the study were (1) the generic screen results of a 3 percent random sample of Medicare beneficiaries age 65 years or older who were admitted to California hospitals between 1 July 1987 and 30 June 1988 (n = 20,136 patients); (2) the 1987 and 1988 California Medicare Provided Analysis and Review (MEDPAR) data files; and (3) the American Hospital Association (AHA) 1988 Annual Survey of Hospitals.

STUDY DESIGN

Multivariate logistic regression analysis was used to evaluate the association between the results of generic discharge administered by the PROs and two patient outcomes: mortality and readmission within 30 days. The analysis was adjusted for other patient characteristics recorded on the uniform discharge abstract.

PRINCIPAL FINDINGS

Four discharge screens indicated an increased risk of an adverse outcome-absence of documentation of discharge planning, elevated temperature, abnormal pulse, and unaddressed abnormal test results at discharge. The other three discharge screens examined-abnormal blood pressure, IV fluids or drugs, and wound drainage before discharge-were unrelated to postdischarge adverse outcomes.

CONCLUSIONS

Generic discharge screens based on inadequate discharge planning, abnormal pulse, increased temperature, or unaddressed abnormal tests may be important indicators of substandard care. Other discharge screens apparently do not detect errors in care associated with major consequences for patients.

In situ expression of the early growth response gene-1 during murine nephrogenesis

WT1 maps to chromosome 11p13 and encodes a deoxyribonucleic acid (DNA) binding protein whose expression is necessary for normal urogenital development. The WT1 protein binds to some of the same DNA sequences as the early growth response gene-1 (EGR-1) protein, the latter being an immediate-early gene product that activates or represses transcription in a promoter and cell-specific manner. Transient transfection experiments have shown that WT1 can repress EGR-1 activated transcription from the EGR-1 promoter. To determine if WT1 is likely to be a physiologically important repressor of EGR-1 we performed ribonucleic acid (RNA) in situ hybridization of EGR-1 on sequential sagittal sections of murine embryos before and throughout nephrogenesis, and compared the results to our previous study of WT1 expression during murine embryogenesis. Prior to embryological day 9.5 WT1 messenger RNA expression is absent in the embryo proper but is expressed in the maternal uterus. With the initiation of organogenesis on embryological day 10.5 WT1 messenger RNA localizes within the pronephric and mesonephric tissues. By embryological day 11.5 the nephrogenic cord, urogenital ridge and metanephric tissue have WT1 hybridization signals and increasingly centripetal expression of WT1 in the kidney correlates with differentiation from embryological days 11.5 to 16.5. In contrast to previous reports of the tissue restricted expression of WT1, EGR-1 expression by in situ hybridization was apparent in all 3 germ layers and their derivatives throughout embryogenesis. Down-regulation of EGR-1 expression occurred in the maternal uterus as well as the metanephric blastema and its derivatives during renal development. This observation defines a spatial and temporal window during which WT1 competition for EGR-1 DNA binding sites may be involved in regulating EGR-1 expression.

Up-regulation of p21WAF1/CIP1 in psoriasis and after the application of irritants and tape stripping

p21WAF1/CIP1 is a nucleoprotein that was initially characterized by its ability to be regulated transcriptionally by p53 and by its ability to mediate growth arrest by binding to cyclin-dependent kinases. Although p21WAF1/CIP1 is thought to mediate the effects of p53 in causing growth arrest, p21WAF1/CIP1 is also regulated in a p53-independent manner, e.g., during terminal differentiation of some cell lines. Growth factors including epidermal growth factor also induce p21WAF1/CIP1 through p53-independent pathways. Because the epidermal growth factor signaling pathway is abnormal in psoriatic epidermis, we studied p21WAF1/CIP1 expression, using in situ hybridization and immunohistochemistry, in psoriasis. Both p21WAF1/CIP1 mRNA and protein were significantly elevated in untreated psoriatic plaques compared with uninvolved psoriatic skin (p < 0.0001), with the up-regulation of p21WAF1/CIP1 being predominantly suprabasal. This increase was accompanied by a small increase in p53 protein expression of uncertain significance. Furthermore, p21WAF1/CIP1 expression was induced in skin after sellotape stripping and by the application of agents, such as dithranol, that are capable of inducing hyperproliferation. The pattern of p21WAF1/CIP1 expression observed is consistent with a role in induction and maintenance of differentiation. Our experiments, however, cannot determine whether the abnormalities of p21WAF1/CIP1 epidermal expression in psoriasis and after insult are independent of changes in p53 expression.

The effect of target site transcription on gene targeting in human cells in vitro

We evaluate the effect of target site transcription on gene targeting in cultured human fibrosarcoma cells. A number of cell lines that harbored a plasmid recombination substrate within their chromosomal DNA were created. Gene targeting frequency was then measured at these different loci in the presence and absence of an agent that stimulated target site transcription. We observed that gene targeting was significantly enhanced by RNA transcription. The magnitude of transcription-stimulated gene targeting varied from 3-fold to > 20-fold. No increase in gene targeting was observed, however, when transcription proceeded away from, rather than through, the recombination site. Transcription-stimulated gene targeting was also observed when single-stranded plasmid vectors complementary to either the coding or template strand were used as recombination substrates. Our results indicate that gene targeting, like other forms of DNA recombination, can be stimulated by target site transcription. The implications of our observations on current models of transcription-stimulated recombination are discussed.

Cloning and mapping of a human gene (TBX2) sharing a highly conserved protein motif with the Drosophila omb gene

We have identified and cloned a human gene (TBX2) that exhibits strong sequence homology within a putative DNA binding domain to the drosophila optomotor-blind (omb) gene and lesser homology to the DNA binding domain of the murine brachyury or T gene. Unlike omb, which is expressed in neural tissue, or T, which is not expressed in adult animals, TBX2 is expressed primarily in adult in kidney, lung, and placenta as multiple transcripts of between approximately 2 and 4 kb. At least part of this transcript heterogeneity appears to be due to alternative polyadenylation. This is the first reported human member of a new family of highly evolutionarily conserved DNA binding proteins, the Tbx or T-box proteins. The human gene has been mapped by somatic cell hybrid mapping and chromosomal in situ hybridization to chromosome 17q23, a region frequently altered in ovarian carcinomas.

Polymicrobial sepsis following trauma inhibits interleukin-10 secretion and lymphocyte proliferation

Immune competence declines following major injury, and predisposes the trauma patient to infection. Interleukin-10 (IL-10), although an immunosuppressive cytokine, is also important in the initiation of immune responses. This study investigated alterations in IL-10 and immune function associated with polymicrobial sepsis following trauma using murine femur fracture (FFx) and cecal ligation/puncture (CLP) models. Mice were randomized to Normal, FFx, Alcohol and FFx (EtOH + FFx), CLP, FFx + CLP, and EtOH + FFx + CLP. Polymicrobial sepsis was induced by performing CLP 4 days after FFx, and animals were killed 14 days later; immune function was assessed by in vitro splenocyte cultures. Lymphocyte proliferative responses were significantly suppressed in FFx and CLP animals. Splenocyte IL-10 production was significantly reduced in FFx and CLP animals, with concurrent increases in nitrite and tumor necrosis factor release. This study documents that trauma induces alterations in the inflammatory cytokine cascade that affect the immune response to subsequent septic challenges.

Superimposition of PET images using 18F-fluorodeoxyglucose with magnetic resonance images in patients with pancreatic carcinoma

Six patients with histologically proven adenocarcinoma of the pancreas were studied using 2-deoxy-2-[18F]-fluoro-D-glucose (18F-FDG) using positron emission tomography (PET), and magnetic resonance imaging (MRI). In all six cases there was avid accumulation of 18F-FDG within the pancreatic tumour and clear visualization of the tumour on the MRI images. Delineation of the tumours was aided by superimposition of the images from the two imaging methods, which was achieved by using a system of surface markers.

Autonomic failure, depression and anxiety in Parkinson's disease

BACKGROUND

The study tested the hypothesis that subjects with Parkinson's disease (PD) have more autonomic complaints and more attenuation of autonomic reflexes than controls, and that both clusters of variables are related to the presence of anxiety and depression.

METHOD

Thirty-two subjects and 32 healthy controls matched by age and sex were prospectively compared on psychiatric, cognitive and autonomic tests.

RESULTS

'Autonomic' symptoms: were more frequent in PD patients than in healthy controls; were not related to age or changes in autonomic reflexes; were significantly associated with depression and anxiety (medication was not relevant to the association); and did not correlate with motor symptoms.

CONCLUSIONS

The diagnosis of anxiety and depression in some PD subjects is likely to be a behavioural phenocopy caused by autonomic failure. This explains why antidepressant medication is often unhelpful in PD subjects diagnosed as depressed.

Alterations in diaphragm EMG activity during opiate-induced respiratory depression

While opiate-induced increases in thoracic muscle tone may contribute to impaired ventilation during opiate anesthesia, the effects of high-dose opiates on diaphragm muscle activity have not been elucidated. The effects of the opiate agonist alfentanil (ALF, 500 micrograms/kg subcutaneously) on diaphragm (DIA) and intercostal (IC) electromyographic (EMG) activity in spontaneously ventilating adult rats were studied. EMG segments corresponding to inspiration and expiration were selected using an impedance plethysmographic respiratory waveform. Total EMG activity over a respiratory cycle was significantly greater in the DIA than in the IC. ALF produced a decrease in inspiratory and an increase in expiratory DIA EMG activity. These changes in diaphragm function following ALF were accompanied by significant respiratory depression. The effects of the alpha-2 agonist dexmedetomidine on ALF-induced changes in diaphragm and intercostal EMG activity were also examined. While dexmedetomidine alone had minimal effects on DIA activity, it significantly attenuated the ALF-induced increase in expiratory DIA EMG. The potential etiology and implications of these opiate-induced changes in diaphragm muscle function are discussed.

Primary care for women. Comprehensive cardiovascular assessment

This article identifies the tools necessary for basic primary care assessment and evaluation of the cardiovascular system in women. Risk factors and abnormalities associated with cardiovascular problems are discussed. Guidelines are presented that will enable the primary care clinician to determine normal cardiovascular function in women, identify risk factors that indicate the need for preventive care, and discover abnormalities that may require referral and intervention.

Inner-city hospitals: a call for research

Inner-city hospitals serve as safety nets for poor and underserved populations. They cope with serious issues of uncompensated care, aging facilities, and inadequate reimbursement. Yet, little research exists on their needs and problems. The authors argue that research on inner-city institutions is necessary to obtain "policy" attention, legitimize demand for resources, reframe inner-city health issues as a delivery problem, and gain insights on better ways to manage inner-city hospitals. They provide data-based illustrations of future research questions related to issues of inefficiency, overstaffing, case severity, and facility renovation that can contribute to better policymaking on inner-city hospitals. The authors recognize systemic barriers to research including the unpopularity of access issues, lack of data, and absence of input from practitioners working in inner-city institutions. To remove such barriers, they suggest creation of a representative forum, original databases, increased linkage with research and policy agencies, and increased cooperation between inner-city professionals and researchers.

Nitric oxide inhibition normalizes splenocyte interleukin-10 synthesis in murine thermal injury

OBJECTIVE

To examine the effect of nitric oxide inhibition on cytokine production and immunologic function in a murine thermal-injury and an alcohol (ETOH)-ingestion model.

DESIGN

Randomized controlled experiment.

SETTING

University surgical research laboratory.

ANIMALS

Forty male Balb/C mice.

INTERVENTIONS

Animals were randomized to four groups: normal saline solution-sham (NS-sham), ETOH-sham, NS-burn, and ETOH-burn. Animals received 20% ETOH or NS daily for 14 days by gavage. A 20% full-thickness burn was induced 4 hours after the last dose of ETOH or NS was administered. Animals were killed 4 days after the burn was induced.

MAIN OUTCOME MEASURES

Splenocytes were harvested and stimulated with the mitogens lipopolysaccharide or concanavalin A. These mitogen-stimulated splenocyte cultures had the addition of exogenous N-monomethyl-L-arginine (2.5 or 10 micrograms/mL), a nitric oxide synthase inhibitor. Splenocyte production of interleukin-10 (IL-10), interferon-gamma, nitrite, and prostaglandin E2 were measured, and lymphocyte proliferative response was examined.

RESULTS

Interleukin-10 and interferon-gamma production were significantly suppressed in thermal injury, and lymphocyte proliferative response was markedly reduced. Exogenous N-monomethyl-L-arginine normalized splenocyte IL-10 production in a dose-dependent manner in NS-burn and ETOH-burn groups, improved lymphocyte proliferative response, and significantly decreased splenocyte nitrite production. Interferon-gamma release was not up-regulated by N-monomethyl-L-arginine.

CONCLUSIONS

Thermal injury is associated with a suppression of splenocyte IL-10 production and lymphocyte proliferative response. Inhibition of nitric oxide synthesis normalized IL-10 production and significantly improved splenocyte proliferative response. These data suggest that nitric oxide is an important modulator of cytokine regulation and immunologic function in thermal injury, thereby ultimately influencing host defense.

Ondansetron prevents postoperative nausea and vomiting in women outpatients

Three doses of intravenous (i.v.) ondansetron, 1 mg, 4 mg, and 8 mg, were compared to placebo for their antiemetic effect and safety. The drugs or placebo were administered in a double-blind manner, prophylactically to 589 women undergoing elective outpatient surgical procedures under nitrous oxide opioid-based general endotracheal anesthesia. In the postanesthesia care unit, the number of emetic episodes, periodic assessments of nausea severity using an 11-point scale (0 = no nausea; 10 = worst nausea), vital signs, and adverse events were collected by an independent observer for 2 h. Upon discharge, identical information, with the exception of vital signs, was collected from the patients' diary and via phone call. One pre- and two poststudy blood specimens for hematology and chemistries were evaluated. During the initial 2 h, patients receiving any dose of ondansetron had significantly better complete response rates (no emesis) than those receiving placebo. Over the 24-h study period, patients who received either 4 mg or 8 mg ondansetron continued to have significantly greater complete response rates. Adverse events were minor, and ondansetron-treated patients had profiles similar to those of the placebo. Heart rate, blood pressure, respiratory rate, and laboratory safety variables were not different among the groups. Ondansetron did not prolong awakening time. This study indicates that ondansetron is a safe and effective prophylactic antiemetic for women who have outpatient surgery under nitrous oxide opioid-based general anesthesia.

Dissociation of erythema and p53 protein expression in human skin following UVB irradiation, and induction of p53 protein and mRNA following application of skin irritants

The mechanisms mediating the varied effects of ultraviolet radiation (UVR) on human skin are unclear, although a relationship between erythema and DNA damage is suggested by photosensitivity in xeroderma pigmentosum. Increased p53 expression in response to UVR is thought to reflect direct DNA damage, but recent evidence indicates that UVR also activates membrane and cytosolic signal transduction pathways. In this study, we have investigated the relationship between erythema and p53 induction following UVB and whether this p53 response is specific to UVR. p53 protein expression was determined by immunocytochemistry using the monoclonal antibody DO7, and p53 mRNA expression was examined by non-isotopic in situ hybridization. Incremental doses of UVB were administered to the lower back of eight subjects. Immunostaining revealed that p53 positive nuclei were significantly increased 8 h after suberythemogenic doses of UVB (79 +/- 12), compared to normal unirradiated skin (8 +/- 6, p < 0.0005), but no change in p53 mRNA was seen. Higher UVB doses, which resulted in moderate erythema, resulted in a similar or greater induction of p53 protein. Indomethacin (1% w/v), applied immediately after UVB irradiation, significantly inhibited UVB erythema at 8 h in six subjects (p < 0.005), but did not reduce p53 immunostaining. Dithranol (1 microgram/microliter, n = 8), sodium dodecylsulphate (5%, n = 4), and retinoic acid (0.5%, n = 4), applied for 48 h, caused erythema, significantly increased p53 protein levels (p < 0.05), and also increased p53 mRNA. Our results show that in human skin, UVB-induced p53 elevation can be dissociated from erythema and skin irritants can also induce p53 protein. The induction of p53 mRNA by irritants but not UVR suggests different mechanisms of action.

Career management: pay considerations

As nurse managers move into new and expanded leadership roles, there are many considerations. One issue that frequently arises is pay--how to negotiate your own pay and how to be sure you receive a reasonable compensation package. This article addresses the most common issues and gives examples of practical approaches.

Calculation method for retinal irradiance from extended sources

A method is given for calculating retinal irradiance from an extended source, whether the source is focused on the retina or not. Both the refractive state of the eye and the source distance from the eye are taken into consideration. Examples for emmetropic and ametropic eyes are given.

The role of computerized tomography in shoulder arthrography

Double contrast computerized tomographic (CT) shoulder arthrograms of 55 shoulders were reviewed. This investigation was compared with conventional arthrograms and the findings were correlated with subsequent clinical and surgical follow-up. CT arthrograms were found to be useful in demonstrating bony, ligamentous and cartilaginous structures and have helped the surgeon in deciding the approach and type of surgical procedure. Indications for CT arthrography are recurrent dislocation, multidirectional instability, severe rheumatoid arthritis and other arthritides, complex shoulder deformities and suspected loose bodies. We found that this examination was not as helpful for rotator cuff injuries, impingement syndrome, adhesive capsulitis and in cases of vague or mild shoulder pain.

Effects of antiplatelet therapy with indobufen or aspirin-dipyridamole on graft patency one year after coronary artery bypass grafting

Saphenous vein coronary artery bypass graft patency can be increased by antiplatelet therapy. Aspirin plus dipyridamole are effective but are associated with tolerability problems. Indobufen is a possible alternative antiplatelet agent that may be better tolerated. A prospective, randomized, double-blind, parallel-group study was undertaken to compare the efficacy and safety of indobufen 200 mg twice daily with aspirin 300 mg thrice daily plus dipyridamole 75 mg thrice daily in preventing occlusion of autologous saphenous vein coronary artery bypass grafts. A total of 803 patients were randomized in the study, of whom 552 had a follow-up coronary angiogram approximately 1 year after operation. All anastomoses were patent in 56% of indobufen-treated patients and 59% of aspirin-dipyridamole recipients (p = 0.384). The percentage of all anastomoses patent was 82% in the indobufen group and 83% in the aspirin-dipyridamole group (p = 0.297). Mean postoperative blood loss was significantly less in the indobufen group (p = 0.043). Patients who received indobufen also had significantly fewer adverse events considered to be treatment-related compared with aspirin-dipyridamole recipients (p = 0.02). At the doses tested indobufen was as effective as aspirin plus dipyridamole in preventing occlusion of saphenous vein grafts and was better tolerated. Because indobufen was associated with less postoperative blood loss it may be used before operation in coronary artery bypass grafting.