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Query: UMLS:C0038187 (starvation)
 24,951 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The effect of human recombinant tumor necrosis factor (TNF)-alpha on enzymes of gluconeogenesis in the rat was investigated by determining the activity of glucose 6-phosphatase, fructose 1,6-diphosphatase (FDP), and phosphoenolpyruvate carboxykinase in the liver and kidney of fed and fasted rats. The activity of transaldolase in the pentose phosphate pathway was also measured. Starvation of rats for 24 hr resulted in a 1.6- to 3.1-fold increase in liver and kidney glucose 6-phosphatase and phosphoenolpyruvate carboxykinase (P less than or equal to 0.05), a decrease in liver and kidney FDP (P less than 0.002), and an increase in liver and kidney transaldolase (P = 0.0001). Injection of 50 and 100 micrograms/kg/day of TNF for 5 days resulted in a significant (P less than or equal to 0.03) decrease in kidney FDP only. Injection of 100 micrograms/kg/day of TNF for 5 days with a 24-hr fast on Day 5 resulted in a significant (P = 0.04) increase in liver transaldolase, and a significant decrease in kidney FDP and phosphoenolpyruvate carboxykinase. Comparison of the enzyme activities of rats injected with 100 micrograms/kg/day of TNF for 5 days with those of their pair-fed control partners revealed additionally a significant decrease in glucose 6-phosphatase in the liver (P less than 0.001). It is concluded that TNF administration in the rat has different effects on the enzymes of gluconeogenesis in the liver and kidney, and these effects differ from those seen in starved or tumor-bearing rats.
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PMID:Effect of tumor necrosis factor on enzymes of gluconeogenesis in the rat. 130 99

Macrophages consume cystine and generate approximately equivalent amounts of acid-soluble thiol. Stimulation of macrophages with bacterial lipopolysaccharide (LPS) or tumor necrosis factor (TNF) strongly augments the amount of thiol released into the culture supernatant. Cysteine constitutes most of the acid-soluble thiol. The intracellular glutathione level and the DNA synthesis activity in mitogenically stimulated lymphocytes are strongly increased by either exogenously added cysteine, or (syngeneic) macrophages. This cysteine dependency is observed even in the presence of relatively high extracellular cystine concentration as they occur in the blood plasma. The extracellular cysteine concentration also has a strong influence on the intracellular glutathione concentration, viability, and DNA synthesis of cycling T cell clones. Moreover, the cysteine concentration in the culture medium on Day 3 and Day 4 of a 5-day allogeneic mixed lymphocyte culture (i.e., in the late phase of incubation) has a strong influence on the generation of cytotoxic T cell activity, indicating that regulatory effects of cysteine are not restricted to the early phase of the blastogenic response. The inhibitory effect of cysteine starvation on the DNA synthesis of the T cell clones and on the activation of cytotoxic T lymphocytes can be explained essentially by the depletion of intracellular glutathione, since similar effects are observed after treatment with buthionine sulfoximine (BSO), a specific inhibitor of the glutathione biosynthesis. BSO has practically no influence, however, on the N alpha-benzyloxycarbonyl Ne-t-butyloxycarbonyl-L-lysine-thiobenzyl-ester (BLT)-esterase activity and hemolytic activity of the cell lysates from cytotoxic T cells against sheep red blood cells (perforin activity). Taken together, our experiments indicate that cysteine has a regulatory role in the immune system analogous to the hormone-like lymphokines and cytokines. It is released by macrophages at a variable and regulated rate and regulates immunologically relevant functions of lymphocytes in the vicinity.
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PMID:Macrophages regulate intracellular glutathione levels of lymphocytes. Evidence for an immunoregulatory role of cysteine. 236 41

This short review updates information on the release mechanisms of the systemic response to surgical injury and the modifying effect of pain relief. Initiation of the response is primarily due to afferent nerve impulses combined with release of humoral substances (such as prostaglandins, kinins, leukotrienes, interleukin-1, and tumor necrosis factor), while amplification factors include semi-starvation, infection, and hemorrhage. The relative role of the various signals in producing the complex injury response has not been finally determined, but the neural pathway is probably most important in releasing the classical endocrine catabolic response, while humoral factors are important for the hyperthermic response, changes in coagulation and fibrinolysis immunofunction, and capillary permeability. The modifying effect of pain relief on the surgical stress response is dependent upon the technique of analgesia. However, the effect on humoral-mediated responses is small, regardless of the technique used. Afferent neural blockade with local anesthetics is the most effective technique for reducing the endocrine-metabolic response, but only in operations in the lower part of the abdomen, probably because of insufficient afferent blockade during thoracic epidural analgesia. Systemic opiate administration, as well as non-steroidal antiinflammatory drugs, exert only a small modifying effect on the response. Low-dose combined analgesic regimens may provide total pain relief, but exert no important effect on the stress response. In summary, pain alleviation itself may not necessarily lead to an important modification of the stress response, and a combined approach with inhibition of the neural and humoral release mechanisms is necessary for a pronounced inhibition or prevention of the response to surgical injury.
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PMID:The stress response to surgery: release mechanisms and the modifying effect of pain relief. 265 70

Previously we showed that starvation of HL-60 promyelocytic leukemia cells for a single essential amino acid induced irreversible differentiation into more mature monocyte-like cells. Although not an essential amino acid, glutamine is important in the growth of normal and neoplastic cells. The glutamine analogue, alpha S,5S-alpha-amino-3-chloro-4,5-dihydro-5-isoxazoleacetic acid (acivicin) inhibits several glutamine-utilizing enzymes and therefore depletes cells of certain metabolic end products. The current study was designed to examine in vitro the effects of acivicin on growth and differentiation of several established human myeloid leukemia cell lines, including the HL-60 cell line, and of freshly isolated cells from patients with acute nonlymphocytic leukemia (ANLL). Four-day culture of HL-60 cells with acivicin at concentrations of 0.1 to 10.0 micrograms/mL (0.56 to 56 nmol/L) decreased cell growth by 33% to 88% as compared with untreated control cells. Viability of cells was greater than 92% for untreated cells and 93% to 41% for acivicin-treated cells. Cells treated with acivicin differentiated along a monocytic pathway as shown by increased H2O2 production and alpha-naphthyl butyrate esterase (NSE) content. Differentiation was time and dose dependent, and was irreversible. Changes in H2O2 production and NSE content were partially abrogated by co-culture with 10 mmol/L exogenous cytidine and guanosine but not by co-culture with other nucleosides or glutamine. At these concentrations of acivicin, differentiation was associated with expression of the N-formyl-methyl-leucyl-phenylalanine-receptor (FMLP-R) on 8% to 29% of cells as compared with 8% for control cells. Acivicin potentiated the differentiating effects of interferon-gamma, tumor necrosis factor, dihydroxyvitamin D3, dimethylsulfoxide, and retinoic acid. Culture of cells from the U937 (monoblastic), K562 (erythroleukemia), and KG-1 (myeloblastic) cell lines resulted in decreased growth and viability, but not consistently in differentiation. Acivicin decreased survival of freshly isolated ANLL cells and increased their H2O2 production and NSE content. These results suggest that the glutamine analogue acivicin may be useful as a differentiating agent with antileukemia activity in patients with ANLL.
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PMID:Monocytoid differentiation of freshly isolated human myeloid leukemia cells and HL-60 cells induced by the glutamine antagonist acivicin. 279 Jan 98

Data from recent studies suggest that donor fasting imparts a beneficial effect on the viability of transplanted hepatic allografts. Because starvation may temporarily inactivate Kupffer cells, and because these cells are the likely mediators of liver injury after prolonged preservation-reperfusion, the purpose of this study is to establish a link between improved organ viability and Kupffer cell inactivation caused by donor allograft fasting. In an in vivo rat liver transplant model, 48 hours of donor fasting (1) improved allograft viability, (2) significantly decreased Kupffer cell phagocytosis, and (3) significantly decreased cytokine (tumor necrosis factor [TNF]) production postrevascularization. These data validate work from previous studies demonstrating that donor fasting improves allograft viability and furthermore support our previous research implicating activation of Kupffer cells as a causative agent of cold ischemia-preservation injury.
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PMID:Inactivation of Kupffer cells after prolonged donor fasting improves viability of transplanted hepatic allografts. 755 76

Infection-induced malnutrition, the most common form of cytokine-induced malnutrition, results from the actions of proinflammatory cytokines, ie, tumor necrosis factor (TNF) and interleukins 1,6, and 8 (IL-1, IL-6, and IL-8). During acute generalized infections, these cytokines initiate the acute-phase reaction. This reaction is quite stereotyped, and includes fever, malaise, myalgia, headaches, cellular hypermetabolism, and multiple endocrine and enzyme responses. In addition, there is heightened catabolism of muscle proteins and many amino acids; flux of free amino acids into the liver; hepatic synthesis of acute-phase plasma proteins; sequestration of iron and zinc; gluconeo-genesis; insulin resistance; impaired cellular uptake of fatty acids from plasma triglycerides; sizable losses of body nitrogen, potassium, magnesium, phosphate, and zinc; retention of body salt and water; heightened metabolic degradation and/or loss of vitamins; and an activation of the immune system. The pathogenesis of cytokine-induced malnutrition is thus vastly different from the malnutrition caused by uncomplicated starvation. Cytokine-induced malnutrition can have a devastating effect on the immune system and its functions. Although proinflammatory cytokines are found in mucosal fluids, where they contribute to the pathogenesis of inflammatory bowel diseases, it is not known whether cytokines play a role in toxigenic, secretory diarrheas such as cholera, which cause huge losses of body water, electrolytes, and bicarbonate while exhibiting no systemic manifestations of an acute-phase reaction.
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PMID:Herman Award Lecture, 1995: infection-induced malnutrition--from cholera to cytokines. 757 15

Anorexia nervosa is a serious eating disorder characterized by extreme weight loss and abnormalities of the neuroendocrine and immune systems. To determine the potential role of tumor necrosis factor-alpha (TNF-alpha), interleukin-6 (IL-6), and transforming growth factor-beta (TGF-beta) in anorexia nervosa, serum concentrations of these cytokines were measured in patients with anorexia nervosa during starvation and after weight gain. Serum IL-6 and TGF-beta concentrations were both significantly elevated during starvation and returned to levels comparable to those of normal-weight controls by the end of therapy. In contrast, serum TNF-alpha levels were undetectable in all patients and controls. Cytokines may play previously unsuspected roles in anorexia nervosa and its complications.
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PMID:Role of interleukin-6 and transforming growth factor-beta in anorexia nervosa. 789 47

UV irradiation induces apoptosis (or programmed cell death) in HL-60 promyelocytic leukemia cells within 3 h. UV-induced apoptosis is accompanied by activation of a 36-kDa myelin basic protein kinase (p36 MBP kinase). This kinase is also activated by okadaic acid and retinoic acid-induced apoptosis. Irrespective of the inducing agent, p36 MBP kinase activation is restricted to the subpopulation of cells actually undergoing apoptosis. Activation of p36 MBP kinase occurs in enucleated cytoplasts, indicating no requirement for a nucleus or fragmented DNA in signaling. We also demonstrate the activation of p36 kinase in tumor necrosis factor-alpha- and serum starvation-induced cell death using the human prostatic tumor cell line LNCap and NIH 3T3 fibroblasts, respectively. We postulate that p36 MBP kinase is a common component in diverse signaling pathways leading to apoptosis.
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PMID:UV irradiation-induced apoptosis leads to activation of a 36-kDa myelin basic protein kinase in HL-60 cells. 879 39

A novel cDNA, TR2L, isolated from murine NIH 3T3 fibroblasts, was found to modulate tumor necrosis factor (TNF)-mediated apoptosis in murine L929 fibrosarcoma cells. The full-length cDNA (853 bp) encodes a predicted coding region of 56 amino acids (6.3 kD), with 53.6% identity to the C-terminus of rat transcriptional activator FE65. When expressed stably in L929 cells, TR2L protein inhibited TNF cytotoxic response. In contrast, TR2L enhanced anti-Fas antibodies/actinomycin D (ActD)-mediated L929 apoptosis. Alteration of TR2L function occurred by tagging this protein with a 6xHis fragment to the N-terminus (designated 6xH-TR2L). L929 cells which stably expressed 6xH-TR2L acquired a significantly enhanced TNF apoptotic response and increased genomic DNA fragmentation compared to control cells. Enhanced cell death also occurred in these 6xH-TR2L-expressing cells under serum starvation conditions. In contrast, the anti-Fas/ActD-mediated apoptosis was blocked by the 6xH-TR2L protein. Functional role of TR2L protein in regulation of cancer cell susceptibility to TNF-and Fas ligand-mediated apoptosis is suggested.
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PMID:Regulation of tumor necrosis factor-and Fas-mediated apoptotic cell death by a novel cDNA TR2L. 885 35

Insulin found in the CNS may be a key regulator in the balance of energy in the body. Since the peripheral circulation is the principal source of insulin in the CNS, insulin must cross the blood-brain barrier. We examined the retention of radioactively labeled insulin in the brain and its transport from the brain after injection icv in mice. The results were compared with those found in mice after fasting, starvation, refeeding, and the addition of aluminum (previously shown to affect the transport of peptides from the CNS) as well as tumor necrosis factor-alpha (TNF-alpha) (known to interact with peripheral insulin). There was no obvious saturable transport system for insulin from the brain, but the retention of insulin was regulated by both aluminum and starvation. Although TNF-alpha was neither required nor involved chronically in the retention of insulin in the brain, acute ip administration of TNF-alpha produced an early increase in the retention of insulin similar to that found after starvation.
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PMID:Sequestration of centrally administered insulin by the brain: effects of starvation, aluminum, and TNF-alpha. 891 85


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