Improvement in staging of esophageal cancer with the addition of positron emission tomography.

BACKGROUND: Positron emission tomography with the glucose analogue 2-[18F]fluoro-2-deoxy-D-glucose (FDG) has been used to detect and stage a variety of malignancies. We hypothesized that FDG-positron emission tomography would improve staging of patients with esophageal cancer and thereby facilitate selection of candidates for resection. METHODS: Fifty-eight patients (42 men and 16 women) with biopsy-proven esophageal cancer were evaluated with both FDG-positron emission tomography and computed tomography. RESULTS: In all but 2 patients, increased FDG uptake was identified at the site of the primary tumor. Six patients were not operative candidates. Seventeen patients were not candidates for resection because of metastatic disease. Positron emission tomography identified the metastatic disease in all 17 (12 of whom underwent confirmatory biopsy), whereas computed tomography was positive for metastases in only 5. The remaining 35 patients underwent surgical exploration, were judged to have resectable disease and had esophagectomy. Pathologic examination of resected specimens identified lymph node metastases in 21 patients. These nodes were detected by positron emission tomography in 11 patients and by computed tomography in 6. CONCLUSIONS: Positron emission tomography improved staging and facilitated selection of patients for operation by detecting distant disease not identified by computed tomography alone.

Coronary artery bypass grafting after a bilateral lung volume reduction operation.

A 67-year-old man underwent coronary artery bypass grafting 31/2 months after a bilateral lung volume reduction operation for end-stage pulmonary emphysema. The principles of anesthetic management we have developed for use during volume reduction operations were applied with success in this individual and are described in detail. With the increasing application of this intervention as an alternative to lung transplantation, we anticipate further experience in the operative management of associated conditions after lung volume reduction operations.

Endogenous D-factor activity partially mediates the toxic but not the therapeutic effects of tumor necrosis factor.

We have earlier shown that passive immunization against differentiation-inducing factor/leukemia-inhibitory factor (D factor) activity improves the survival of endotoxemic mice, suggesting that D factor may contribute to the systemic toxicity associated with tumor necrosis factor (TNF). In the current experiments, TNF induced D-factor gene expression in various tissues of non-tumor-bearing female C57BI/6 mice. Passive immunization against D-factor significantly improved survival after a lethal TNF challenge in both non-tumor-bearing (p2 < 0.02) and tumor-bearing mice (p2 < 0.01). In mice bearing 10-day s.c. MCA 105 sarcomas, D-factor antibody alone had no effect on tumor growth as compared with control IgG. Tumor regression and regrowth in mice treated i.v. with TNF was not affected by pre-treatment with D-factor antibody, as compared with pre-treatment with IgG. However, TNF-treatment-related mortality was abrogated by pre-treatment with D-factor antibody (0% vs. 36% for IgG-pre-treated controls). These results indicate that endogenous D-factor activity contributes to the toxicity but not to the anti-tumor effects of TNF therapy. With renewed interest in the use of TNF for the treatment of patients with cancer, improved understanding of the role of D factor in mediating the effects of TNF may have important clinical benefits.

Passive immunization of mice against D factor blocks lethality and cytokine release during endotoxemia.

D factor, also known as leukemia inhibitory factor, is a pleiotropic cytokine whose role during acute injury and inflammation is not known. Intraperitoneal administration of Escherichia coli endotoxin induced D factor gene expression in mice, and passive immunization against D factor protected them from the lethal effects of endotoxin and blocked endotoxin-induced increases in serum levels of interleukin 1 and 6. Peak levels of tumor necrosis factor and interferon gamma were not affected. These results indicate that D factor is an essential early mediator of the inflammatory cytokine response and therefore may be important in the pathogenesis of the many inflammatory conditions, such as sepsis, arthritis, allograft rejection, and cancer immunotherapy.

Cholera toxin pretreatment protects against tumor necrosis factor lethality without compromising tumor response to therapy.

Antitumor therapy with tumor necrosis factor is limited by systemic toxic effects. We studied whether cholera toxin, a bacterial exotoxin that adenosine diphosphate-ribosylates the alpha-subunit of Gs proteins, could separate the lethal from the antitumor effects of tumor necrosis factor. A single dose of intravenous cholera toxin protected non-tumor-bearing mice from a lethal dose of Escherichia coli endotoxin administered 6 or 24 hours later. On the basis of these results, tumor-bearing mice were randomized to receive either cholera toxin or saline, followed 6 hours later by either human tumor necrosis factor (400 micrograms/kg) or saline. Tumor-bearing mice pretreated with cholera toxin had (1) reduced treatment-related mortality (0/11 vs 5/11 for saline controls) and (2) tumor regression similar to that of controls. In a separate experiment in tumor-bearing mice, intravenous human tumor necrosis factor treatment induced an increase in serum levels of murine tumor necrosis factor to a peak of 500 pg/mL at 1 hour in saline-pretreated controls, while a similar increase could not be detected in those mice pretreated with cholera toxin. These results suggest that pretreatment with cholera toxin can reduce the endogenous tumor necrosis factor response to administered tumor necrosis factor and separate the lethal from the antitumor effects. Cholera toxin may prove to be a useful tool for investigating the mechanisms underlying the varied effects of tumor necrosis factor.

Single-dose tumor necrosis factor protection against endotoxin-induced shock and tissue injury in rats.

Tumor necrosis factor (TNF), a macrophage product released in response to endotoxin and other stimuli, has been shown to be a central mediator of endotoxin or septic shock. However, its highly conserved and wide-ranging physiological effects suggest that it may also be an essential cytokine in the host defense against acute bacterial infection or sepsis. A single nontoxic dose of human recombinant TNF administered intravenously 24 h prior to a lethal infusion of Escherichia coli lipopolysaccharide (LPS) completely prevented acute LPS-induced hypotension, ameliorated tissue injury in the lungs and liver, and improved survival in male Fisher 344 rats. The protective effects of TNF were dose dependent and required a 24-h pretreatment interval. After the infusion of LPS, animals in both groups (TNF-treated animals and saline-pretreated controls) initially appeared acutely ill and had a similar severe metabolic acidosis, indicating that TNF did not inactivate or prevent the toxic effects of LPS. Twelve hours after the administration of TNF, the gene for manganous superoxide dismutase, a mitochondrial enzyme which scavenges toxic reactive oxygen species and is induced during conditions which generate a free radical stress, was expressed in liver tissue, suggesting that the induction of manganous superoxide dismutase may be an important in vivo protective mechanism against cellular injury during lethal endotoxemia.

Human recombinant interleukin-1 alpha protection against the lethality of endotoxin and experimental sepsis in mice.

Human recombinant interleukin-1 alpha (IL-1) has a diverse range of physiological activities which may be beneficial or deleterious to the host. Pretreatment with doses of IL-1 has been shown to protect mice against a subsequent lethal bacterial injection; however, the protective effects of a single intravenous (iv) dose of IL-1 have not been well characterized. The current experiments were performed to determine the best dose, timing, and duration of action of a single iv dose of IL-1 against a subsequent lethal challenge with intraperitoneal endotoxin (LPS) or experimental sepsis induced by cecal ligation and puncture (CLP). Female C57B1/6 mice treated with iv IL-1 24 hr prior to 30 mg/kg LPS ip had improved survival compared to saline-treated controls (P less than 0.01). IL-1 was also protective when given 6 to 72 hr, but not 2 or 96 hr, prior to LPS. IL-1 protection against LPS lethality was similar to protection seen with an iv dose of tumor necrosis factor (TNF). After CLP, survival was improved with IL-1 versus saline pretreatment (P = 0.02). Unlike previous work with TNF, no toxicity or lethality was observed at any dose of IL-1 administered. A single iv dose of IL-1 protects against the lethality of LPS and CLP in mice. IL-1 may be a useful treatment strategy in patients at risk for the development of life-threatening sepsis.

Myocytolysis (vacuolar degeneration) of myocardium: immunohistochemical evidence of viability.

Human myocardium with focal myocytolysis (vacuolar degeneration, colliquative myocytolysis) was examined by routine light microscopy and by immunoperoxidase staining techniques for creatine kinase (CK) M and B, myoglobin, lactate dehydrogenase (H4)(LDH-1), and aspartate aminotransferase (AST, GOT). Sections of myocardium were selected from autopsy and surgical specimens from patients with and without clinical morphologic evidence of ischemic heart disease. Areas of coagulation necrosis showed loss of enzyme staining, while both normal and myocytolytic cells stained darkly. These results indicate that fibers with myocytolysis retain enzymes and other proteins, indicating sarcolemmal integrity, which is not present in fibers with coagulation necrosis. The implication of these findings is that fibers with myocytolysis are viable; thus, myocytolysis may be a reversible form of myocardial alteration that does not necessarily lead to cell death and eventual myocardial fibrosis.

Myocardial myoglobin following coronary artery occlusion. An immunohistochemical study.

To evaluate morphologic changes and myoglobin content in normal, ischemic and necrotic myocardium, the authors studied human (n = 13) and dog (n = 28) myocardium by triphenyltetrazolium chloride staining, light and electron microscopy, periodic acid-Schiff stain for glycogen loss, and by an immunoperoxidase technique. Myocardium from autopsied patients with infarction 10-24 hours old showed loss of myoglobin from necrotic fibers. Dogs with infarcts after 3 hours or more of coronary occlusion showed myoglobin loss in fibers shown to be necrotic. In 4 dogs with 50% reduction in left main coronary artery flow for 3 hours, which demonstrated ischemia without necrosis (glycogen loss with no triphenyl tetrazolium chloride evidence of necrosis), myoglobin staining in myocardial sections was similar to nonischemic and positive control tissues. By comparison of immunoperoxidase staining with concomitant study by light and electron microscopy and histochemistry, loss of myoglobin from necrotic myocardium was demonstrated, while ischemic but not necrotic fibers stained normally. These findings indicate that necrosis is necessary for myoglobin loss from myocardium to be detected by this immunoperoxidase technique.