Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0011570 (depression)
 172,036 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

To determine whether phagocytosis mediated by Fc receptors and/or receptors for the third component of complement (C3b) are altered after hemorrhage, C3H/HeN mice were subjected to nonlethal hemorrhage and then adequately resuscitated. Twelve hours after the hemorrhagic episode, a significant decrease in both Fc (-55.2%) and C3b (-46.6%) receptor-positive peritoneal macrophages was observed compared with controls. At 24 hours the extent of the depression, while still marked, was only -22.5% and -17.4% for Fc and C3b receptors, respectively. By day 3 after hemorrhage, no differences could be observed for either of these receptors. The capacity of macrophages from mice after hemorrhage to elaborate interleukin 1 or tumor necrosis factor-alpha showed no increase over that of the sham controls, and serum levels of endotoxin were not elevated 2 or 24 hours after hemorrhage. Moreover, endotoxin-tolerant C3H/HeJ mice also exhibited depression of both receptors after hemorrhage. Thus, the inability of the host macrophages to clear opsonized infectious agents after hemorrhage may be due in part to the loss of Fc and C3b receptors on macrophages.
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PMID:Enhanced susceptibility to sepsis after simple hemorrhage. Depression of Fc and C3b receptor-mediated phagocytosis. 213 90

Expression of tumor necrosis factor (TNF alpha), tissue factor (TF), and interleukin 1-beta (IL-1 beta) mRNA was evaluated in monocytes isolated from patients infected with human immunodeficiency virus (HIV). There was a significant depression (66%) of the induced level of TF mRNA expression in response to lipopolysaccharide. Conversely, the response of TNF alpha and IL-1 beta, following LPS induction, was "normal." TF mRNA reduction was also observed to a lesser degree in AIDS-related complex patients (20%) but not in asymptomatic seropositives. TF is necessary for initiation of the coagulation protease cascade, leading to thrombin production and fibrin deposition, which play a role in inflammatory responses. Its selective reduction may be a factor in the diminished resistance to secondary infections observed in AIDS. Further, since the TF defect increases as patients progress toward AIDS, it may serve as a marker for disease progression.
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PMID:A selective defect in tissue factor mRNA expression in monocytes from AIDS patients. 229 2

The increased susceptibility to infections after surgery in jaundiced patients is considered to be caused by an impairment of cellular immunity and/or nutritional status. Endotoxins are suggested to play a role in the pathogenesis. However, the mechanism of action is unknown. Germ-free rats were used to study the effect of biliary obstruction in a model with negligible amounts of endotoxin. Cellular immunity, production of tumor necrosis factor (as a mediator of endotoxin toxicity) by peritoneal macrophages, and the nutritional status were assessed. Significant suppression of cellular immunity was found in conventional rats with obstructive jaundice. In contrast, cellular immunity was not suppressed in jaundiced germ-free rats. Large amounts of tumor necrosis factor were spontaneously secreted by peritoneal macrophages of jaundiced conventional rats, whereas macrophages from jaundiced germ-free rats did not. Moreover macrophage activation (expressed in tumor necrosis factor production) was significantly related to suppression of cellular immunity. Weight changes and depression of albumin levels were not different in germ-free and conventional rats after bile duct ligation. The data presented indicate that suppression of cellular immunity in obstructive jaundice is caused by endotoxins, whereas the impaired nutritional status seems to not be affected by the presence of endotoxins.
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PMID:Suppression of cellular immunity in obstructive jaundice is caused by endotoxins: a study with germ-free rats. 229 4

Cachectin/tumor necrosis factor-alpha (TNF), a protein produced by macrophages upon stimulation, has been implicated as an important mediator of inflammatory processes and of clinical manifestations in chronic infectious diseases. In order to study further the potential role of TNF in infectious diseases, a homologous system was employed in which recombinant Escherichia coli (E. coli) derived bovine TNF (rBoTNF) was injected in cattle, either as a single bolus or in a repetitive treatment-regime. No clinical signs were observed, although changes occurred in hematologic and immunologic parameters when less than 0.5 mg of TNF/100 kg body weight was administered twice daily for 18 days. Prolonged treatment with 0.05-0.5 mg/100 kg induced histologic but no gross changes in the kidneys and liver. When doses were increased above 0.5 mg/100 kg, depression, anorexia, cachexia, and diarrhea appeared rapidly. Pathologic changes were apparent in various tissues including liver, kidneys, and lymphoid organs; body fat depots were depleted. Most of these changes appeared to be reversible; return to normal tissue-morphology occurred within 3 weeks of withdrawal of rBoTNF. The clinical and pathologic changes induced by prolonged rBoTNF administration resembled those observed in some chronic parasitic and viral infections of cattle in which macrophage-activation characteristically occur. Our finding may be relevant to the elucidation of the pathogenesis of these and other chronic infections.
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PMID:Effect of chronic administration of recombinant bovine tumor necrosis factor to cattle. 260 27

The cytotoxic mechanism of action of tumor necrosis factor (TNF) was examined using murine L929 fibrosarcoma cells in vitro. Two cell lines were evaluated: parental TNF sensitive (L929S) (50% cytotoxic concentration, 2-6 ng/ml); and TNF resistant (L929R) (50% cytotoxic concentration, greater than 10,000 ng/ml). The latter resistant cell line was developed by serial passage in increasing concentrations of recombinant human TNF. Sensitive cells demonstrated cytolytic and cytostatic effects at TNF concentrations between 2 and 6 ng/ml, respectively. However, TNF failed to show any selective depression of RNA, DNA, or protein synthesis or ATP content in these cells until general cell death was apparent, as defined by the cell rounding and lifting off the plastic surface. The cytokine also failed to cause DNA single-strand breaks, as detected by alkaline elution techniques. TNF was also found to be no more active in glutathione-depleted cells than in target cells containing normal glutathione levels. In contrast, various nonspecific lysosomotropic agents such as ammonium chloride and D-saccharic acid lactone led to a marked inhibition of the cytotoxic action of TNF in vitro. Furthermore, significant differences in lysosomal enzyme activity were noted between L929S and L929R cells. The changes in L929R cells involved a 50% reduction in total lysosomal protein levels and a marked depression of beta-glucuronidase activity. In contrast, L929R lysosomal hexosaminidase activity was significantly elevated over the L929S cells. From these studies it is concluded that the antitumor activity of TNF does not involve specific inhibition of macromolecular synthesis, ATP production, or the level of reduced thiols. Instead, TNF cytotoxicity appears to require functional lysosomes, which are altered when TNF resistance develops in vitro.
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PMID:Association of lysosomal activity with sensitivity and resistance to tumor necrosis factor in murine L929 cells. 271 56

Multiple system organ failure (MSOF) is a progressive dysfunction of vital organs that may develop in clinical settings such as sepsis or multiple trauma. One component of this syndrome is cholestasis and impaired liver function. The mechanism(s) for this liver failure (and the failure of other organs) remains obscure. Macrophages and Kupffer cells have been shown to secrete cytokines such as interleukin-1 and tumor necrosis factor. These cytokines mediate many aspects of the acute phase response, and they also can produce cellular injury. The purpose of this study was to evaluate the effects of a semipurified murine monokine preparation having interleukin-1 activity on bile flow in the rat isolated perfused liver (IPL). The monokine preparation produced a significant reduction of bile flow in the IPL system. The effect could not be explained by a venoocclusive phenomenon or residual endotoxin in the monokine preparation. We conclude that a semipurified monokine preparation having interleukin-1 but not tumor necrosis activity produced a significant depression of bile flow in the IPL, and we suggest that macrophage secretory product(s) may be responsible for the cholestasis in MSOF.
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PMID:Monokine depression of bile flow in the isolated perfused rat liver. 277 Feb 82

Treatment of mice with endotoxin (lipopolysaccharide, LPS) and the two LPS-induced monokines, tumor necrosis factor (TNF) and interleukin-1 (IL-1), caused a depression of liver cytochrome P-450 and related drug-metabolizing enzymes, as well as other acute-phase changes including increase in plasma fibrinogen levels and hypoferremia. However, only IL-1, not TNF or LPS, depressed cytochrome P-450 in cultured hepatocytes, suggesting that the effect of TNF in vivo might be mediated by a second mediator. TNF- or LPS-stimulated monocytes released a factor capable of depressing cytochrome P-450 in cultured hepatocytes. This factor was inhibited by anti-IL-1 antiserum, and its synthesis, like that of IL-1, was inhibited by dexamethasone (DEX). Pretreatment of mice with DEX protected against the depression of liver cytochrome P-450 by LPS or TNF but not by IL-1, suggesting that IL-1 directly depresses cytochrome P-450 and that DEX acts by inhibiting IL-1 synthesis in vivo induced by LPS or TNF. However, DEX did not inhibit two other effects of LPS and TNF in vivo: increase of plasma fibrinogen levels and decrease of plasma iron, suggesting that these might not be mediated by IL-1. Therefore, the effect of DEX in vivo, although supporting the hypothesis that depression of liver cytochrome P-450 by LPS and TNF is mediated by IL-1, indicates the existence of IL-1-independent pathways in the acute-phase response.
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PMID:Dexamethasone modulation of in vivo effects of endotoxin, tumor necrosis factor, and interleukin-1 on liver cytochrome P-450, plasma fibrinogen, and serum iron. 278 6

Mice bearing the S-180 sarcoma displayed a depression of liver catalase and cytochrome P-450-dependent enzymes (ethoxycoumarin deethylase, ED) from day 6 following tumor implantation. Injection of serum obtained from tumor-bearing mice into normal mice caused depression of liver ED suggesting that a circulating factor was involved. Tumor-bearing mice did not show any significant change in serum triglycerides and food intake. By contrast, injection of endotoxin, interleukin-1 (IL-1) or tumor necrosis factor (TNF) caused not only a depression in liver ED but also a marked increase in serum triglycerides. To study the possible analogies between cancer-associated circulating factor and monokines, we studied the effect of dexamethasone (a known inhibitor of monokine synthesis) on liver ED activity in tumor-bearing mice. Dexamethasone (DEX) treatment increased (up to 60%) liver ED activity in tumor-bearing mice. We conclude that: (i) a circulating factor is involved in cancer-associated ED depression; (ii) that this mediator is not necessarily identical to TNF or IL-1 and (iii) that DEX reverses the depression of liver ED in cancer, possibly by inhibiting the synthesis, or the effects, of this factor.
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PMID:Depression of liver drug metabolism in sarcoma-bearing mice. Evidence for a circulating factor and dissociation from lipolytic activity. 326 84

The effect of recombinant tumor necrosis factor on liver cytochrome P450 and related drug metabolism enzymes was investigated. Treatment of mice with tumor necrosis factor caused a marked depression of cytochrome P450 and some drug metabolizing enzymes (ethoxycoumarin deethylase and arylhydrocarbon hydroxylase) in the liver and many other organs. This effect was maximal 24-48 h after treatment and was dependent on the dose of tumor necrosis factor administered. Depression of liver drug metabolizing enzymes was also observed in the endotoxin-resistant C3H/HeJ strain of mice, thus ruling out that this effect may be due to minor endotoxin contamination of recombinant tumor necrosis factor. These data indicate that depression of liver drug metabolism might be an important side effect of tumor necrosis factor, and suggest a role for this macrophage product as an endogenous regulator of liver metabolism.
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PMID:Recombinant tumor necrosis factor depresses cytochrome P450-dependent microsomal drug metabolism in mice. 348 57

Recently many findings about the physiological and biochemical functions of recombinant human tumor necrosis factor (rHu-TNF) have been reported. In the present study, the effect of rHu-TNF on serum iron in C3H/HeN and C57BL/6 mice was determined. Blood samples were obtained before intravenous injection of rHu-TNF, and also at various times after the injection. Results from five experiments showed that the serum iron was depressed between 1/3 to 1/5 of that of untreated mice 4 to 24 h after injection of 5 or 10 micrograms of rHu-TNF. The low level persisted for 33 h, rebounded at 48 to 72 h, and returned to normal by 96 h after the injection. Serum iron was determined by the colorimetric method using the sensitive reagent, ferrozine (3-(2-pyridyl)-5,6-bis(4-sulfophenyl)-1,2,4-triazine. We believe that this is the first report of depression of serum iron in mice by intravenous injection of rHu-TNF. The physiological role of repressed serum iron in the in vivo response to TNF remains to be established.
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PMID:Recombinant human tumor necrosis factor depresses serum iron in mice. 368 44


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