The Journal of laboratory and clinical medicine
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Comparative Study
Evaluation of interleukin-6 in bronchoalveolar lavage fluid and serum of patients with lung cancer.
Increased levels of serum interleukin 6 (IL-6) are found in patients with lung cancer, and it has been shown that this is part of a systemic inflammatory response syndrome. This study was designed to measure IL-6 levels in bronchoalveolar lavage (BAL) fluid of patients with lung cancer and to describe the relationship of BAL fluid IL-6 to the known systemic increase in IL-6. Increased levels of BAL fluid IL-6 can be found in patients with lung cancer as compared with patients with chronic obstructive pulmonary disease who have acute infection (P = .007). ⋯ Serum IL-6 correlated with other acute phase reactants. This study thus demonstrates the feasibility of utilizing BAL fluid analysis for local cytokine/tumor marker production in lung carcinoma. It also shows that a local increase in IL-6 in the BAL fluid is independent of the systemic inflammatory response syndrome, whereas the serum increase in IL-6 is part of this syndrome.
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The pathogenesis of Pneumocystis carinii pneumonia (PCP) suggests an important role for dysfunction of the pulmonary surfactant system in the hypoxemic respiratory insufficiency associated with this infection. Surfactant protein B (SP-B) is a hydrophobic protein shown to be essential for normal surfactant function in vivo. Therefore, we hypothesized that the inhibition of SP-B expression occurs during PCP, and we tested this hypothesis in two immunodeficient animal models. ⋯ The SP-B content of lung homogenates from BALB/c mice depleted of CD4+ T cells and infected with P. carinii was also reduced (51% of the control value). We conclude that P. carinii induces selective inhibition of the expression of SP-B in two mouse models of PCP and that this down-regulation is mediated at the level of mRNA expression. Therefore, an acquired deficiency of SP-B is likely to be an important contributor to the pathogenesis of hypoxemic respiratory failure that is observed in patients with PCP.
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Intestinal ischemia necessitates rapid re-establishment of blood flow to prevent irreversible anoxic tissue damage. However, reperfusion results in additional injury as a consequence of the generation of oxygen free radicals. To date, no clear-cut marker to differentiate between ischemia versus reperfusion injury is available. ⋯ In both experimental models, there was no change in any enzyme activity with warm ischemia alone. In contrast, alkaline phosphatase activity was significantly decreased in both the canine and human reperfusion models, with no change in specific activities of sucrase, maltase, and gamma-glutamyl transpeptidase. Our data indicate that the alkaline phosphatase enzyme activity may represent a potential marker of intestinal reperfusion injury and may permit quantitative assessments of therapeutic interventions in human intestinal reperfusion injury.
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Several growth factors, such as growth hormone and insulin-like growth factor-1, have been used to reverse the high rate of catabolism observed either after an operation or during serious illness. We conducted a pilot study in Wistar rats in an attempt to assess whether regulatory peptides widely used in clinical practice, such as erythropoietin (EPO) and granulocyte macrophage colony-stimulating factor (GM-CSF), alone or in combination, might influence the metabolism after surgery. Forty animals were randomly allocated into four groups (one control group and three experimental groups; 10 animals per group). ⋯ In conclusion, this study demonstrated that the administration of rHuEPO appears to have a beneficial positive effect on the body weight, hematocrit, and healing rate and the breaking strength of large bowel anastomoses in rats. These observations provide evidence of an as-yet-unknown anabolic effect of EPO, and they may expand its usual applications. However, more studies are needed to confirm our findings and furthermore to define the optimal dose and timing of EPO administration.
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Using palladium-porphyrin quenching of phosphorescence, we investigated the influence of diaspirin cross-linked hemoglobin (DCLHb) on gut microvascular oxygen pressure (microPO2) in anesthetized pigs. Values of gut microPO2 were studied in correlation with regional intestinal as well as global metabolic and circulatory parameters. A controlled hemorrhagic shock (blood withdrawal of 40 mL/kg) was followed by resuscitation with either a combination of lactated Ringer's solution (75 mL/kg) and modified gelatin (15 mL/kg)(lactR/Gel) or 10% DCLHb (5 mL/kg). ⋯ Mesenteric venous PO2 was increased after resuscitation with lactated Ringer's solution and modified gelatin but not with DCLHb, which was associated with an increased gut oxygen consumption in the latter group. We conclude that measurement of microPO2 by the palladium-porphyrin phosphorescence technique revealed DCLHb to be an effective carrier of oxygen to the microcirculation of the gut. Also, this effect can be achieved with a lower volume than is currently used in resuscitation procedures.