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Query: UMLS:C0243026 (sepsis)
 52,417 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Hepatocyte injury and necrosis from many causes may result in pediatric liver disease. Influenced by other cell types in the liver, by its unique vascular arrangements, by lobular zonation, and by contributory effects of sepsis, reactive oxygen species and disordered hepatic architecture, the hepatocyte is prone to injury from exogenous toxins, from inborn errors of metabolism, from hepatotrophic viruses, and from immune mechanisms. Experimental studies on cultured hepatocytes or animal models must be interpreted with caution. Having discussed general concepts, this review describes immune mechanisms of liver injury, as seen in autoimmune hepatitis, hepatitis B and C infection, the anticonvulsant hypersensitivity syndrome, and autoimmune polyendocrinopathy. Of the monogenic disorders causing significant liver injury in childhood, alpha-1 antitrypsin deficiency and Niemann-Pick C disease demonstrate the effect of endoplasmic or endosomal retention of macromolecules. Tyrosinemia illustrates how understanding the biochemical defect leads to understanding cell injury, extrahepatic porphyric effects, oncogenesis, pharmacological intervention, and possible stem cell therapy. Pathogenesis of cirrhosis in galactosemia remains incompletely understood. In hereditary fructose intolerance, phosphate sequestration causes ATP depletion. Recent information about mitochondrial disease, NASH, disorders of glycosylation, Wilson's disease, and the progressive familial intrahepatic cholestases is discussed.
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PMID:Mechanisms of liver injury relevant to pediatric hepatology. 1189 Feb 7

The present study was designed to test the hypothesis that induction of chronic peritoneal sepsis in rats would produce a more severe calcium paradox-mediated myocardial injury in isolated heart preparation than is seen in normal hearts, and that this would be inhibited by sucrose as in normal hearts. Male Sprague-Dawley rats were made septic using 200 mg of cecal material (obtained from a donor rat) suspended in 5 mL of 5% dextrose in sterile water D5 W/kg. In septic animals, the cecal material was injected in the peritoneum, while sham-septic animals received only D5 W/kg (5 mL/kg). A third group consisting of normal rats (no surgery) group was also included. Hearts were harvested from all three groups and were subjected to a calcium paradox-mediated injury in an isolated heart preparation. Hearts were perfused with Krebs-Henseleit (KH) medium and were allowed to stabilize, followed by a perfusion with Ca2+-free KH for 10 min. After this 10-min Ca2+-free KH perfusion, rats were reperfused with KH medium for 60 min. Ca2+-free KH medium was used in control experiments, while sucrose experiments were conducted with the same medium except that 150 mM sucrose replaced 75 mM NaCl. A marked decrease in ATP and phosphocreatine occurred during Ca2+ reperfusion in all hearts in absence of sucrose. In the presence of the disaccharide, no change in high-energy phosphate (HEP) levels was observed in normal hearts, while lower ATP concentrations were seen in sham and septic hearts. Thus, sucrose did not inhibit cellular injury in sham and septic hearts as it did in normal hearts, and this might be due to a smaller HEP availability. Control studies with normal, sham, and septic hearts exhibited cessation of contractions in the absence of Ca2+, and appearance of large amounts of cytosolic protein in the effluent perfusate during Ca2+ reperfusion. With normal hearts, perfusion with sucrose caused a 96% inhibition of the total creatine kinase (CK) release observed in control experiments. With sham hearts, 32% of CK release was inhibited by sucrose, while 68% of the CK release was attributed to stress associated with surgery performed in the sham-septic group. In septic hearts, only 8% of the CK release was inhibited by sucrose, suggesting that more severe myocardial injury occurs when septic hearts are subjected to a calcium paradox as compared to other groups. It is evident that sucrose can inhibit a small fraction of the CK release from septic hearts during the calcium paradox as compared to the large CK loss associated with sham sepsis. We have concluded that induction of sepsis made the heart more susceptible to a calcium paradox-mediated myocardial injury.
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PMID:Induction of peritoneal sepsis increases the susceptibility of isolated hearts to a calcium paradox-mediated injury. 1190 Mar 37

Sepsis is associated with oxidative stress and impaired glutamatergic transmission in brain. We investigated whether sepsis impairs accumulation of the antioxidant, ascorbate, and uptake of glutamate by astrocytes. Bacterial endotoxin (Escherichia coli lipopolysaccharide, LPS) and the inflammatory cytokine, interferon-gamma (IFNgamma), were applied to primary astrocyte cultures to model sepsis. In the absence of ascorbate, the combination of LPS and IFNgamma (LPS + IFNgammay) up-regulated inducible nitric oxide synthase (iNOS) and decreased the initial rate of glutamate uptake by 50% within 24 h. Cell viability and facilitated glucose transport activity were not affected at 24 h. Pre-treatment with ascorbate-2-O-phosphate increased intracellular ascorbate concentration and attenuated the induction of iNOS and inhibition of glutamate uptake caused by LPS + IFNgamma. Subsequent experiments examined the mechanisms by which cells accumulate ascorbate. LPS + IFNy decreased slightly the initial rate of uptake of ascorbate and inhibited markedly the rate with which intracellular dehydroascorbic acid (DHAA) was reduced to ascorbate. We conclude that septic insult impairs astrocytic clearance of DHAA from the extracellular fluid and decreases intracellular ascorbate concentration. Furthermore, sepsis induces iNOS and inhibits glutamate uptake by astrocytes through mechanisms that can be modulated by intracellular ascorbate. These results indicate treatments that increase intracellular ascorbate concentration may be beneficial for patients at risk for neurologic complication in sepsis.
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PMID:Sepsis inhibits reduction of dehydroascorbic acid and accumulation of ascorbate in astroglial cultures: intracellular ascorbate depletion increases nitric oxide synthase induction and glutamate uptake inhibition. 1206 32

Calciphylaxis is a rate complication of unknown pathogenesis in patients with end stage renal disease. It is characterized by calcification of tunica media of small arteries associated with intimal fibrosis and thrombus formation which leads to the development of skin and subcutaneous tissue necrosis. Superinfection of skin lesions is a common consequence of this syndrome which may lead to the sepsis. The prognosis of this condition in serious. We performed a retrospective study of 6 subjects (4 men and 2 women) in the age of 35 to 59 years. We followed the parameters of calcium-phosphate metabolism, presence of calciphylaxis risk factors and the effect of parathyreoidectomy. Five patients were on hemodialysis, one had a kidney transplant. Skin and subcutaneous tissue necrosis were present in all subjects. The serum levels of parathormone were either high, normal or low, levels of calcium were normal or slightly elevated and phosphate levels were high or normal. Calcium was substituted before calciphylaxis development in 5 patients, calcitriole in 3 of therm. Five patients underwent parathyroidectomy. Three patients died (all of sepsis), one patient had the lower into amputation for infected lesions and the remaining two achieved regression. Our findings do support the hypothesis that calcium and calcitriole administration participates in development of calciphylaxis. Fatal prognosis of the once infections skin lesions was also proved.
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PMID:[The calciphylaxis syndrome as a complication of chronic kidney failure. 6 case reports and literature review]. 1209 60

Hypophosphatemia in critically ill and postoperative (p.o.) patients is a multifactorial event, and is also related to severity of illness. This study was conducted to assess pathophysiologic correlates of hypophosphatemia and the simultaneous relationship with clinical events after hepatectomy. A total of 333 measurements were obtained in 59 patients: these were performed preoperatively and at p.o. days 1, 3, and 7 in all patients, and subsequently, until recovery or death, only in those with complications. Measurements included plasma phosphate together with a large number of additional blood chemistries, taking into account primary and associated diseases, events associated with the operation, doses of parenteral substrates, occurrence of sepsis or other p.o. complications, outcome, and a consistent set of complementary variables. Plasma phosphate decreased at p.o. days 1 and 3 (P < 0.001) and retumed to a level close to baseline at p.o. day 7. Regression analysis showed that phosphate was related simultaneously to patient age (inversely), levels of creatinine and potassium (directly), and dose of parenteral amino acids (inversely; P < 0.001 for all). Independently of covariation with these variables, there was a decrement in phosphate at p.o. days 1 and 3 that was related specifically to p.o. condition; this decrement had a general component common to all patients, an additional component related to duration of previous hepatic ischemia at surgery, and a further component predictive of the subsequent development of complications (in most cases, sepsis). Plasma phosphate at p.o. day 1 was related inversely to APACHE II score (r2 = 0.4, P < 0.001), and levels lower than 1.5 mg/dL were associated with an almost 4-fold increase in the rate of complications compared with cases with higher phosphate (P < 0.001). The best single variable bridging early evidence of hypophosphatemia to subsequent development of complications was plasma cholesterol, which fell significantly from p.o. day 3 onward in patients with complications compared with those recovering normally (P < 0.01), and in nonsurvivors compared with survivors (P < 0.01). Hypophosphatemia may anticipate clinical evidence of complications by reflecting an early stronger acute-phase response, with shift of phosphate from intra- to extravascular space, or true phosphorus deficiency, which may favor development of complications by impairing high-energy substrate availability for host defense and other cell functions.
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PMID:Pathophysiologic and clinical correlates of hypophosphatemia and the relationship with sepsis and outcome in postoperative patients after hepatectomy. 1216 71

Endotoxin (lipopolysaccharide (LPS)), a component of Gram-negative bacteria, is among the most potent proinflammatory substances known. The lipid-A region of this molecule initiates the production of multiple host-derived inflammatory mediators, including cytokines (e.g. tumor necrosis factor-alpha (TNFalpha)). It has been a continuous effort to identify methods of interfering with the interaction between enteric LPS and inflammatory cells using natural and synthetic LPS analogs. Some of these LPS analogs (e.g. Rhodobacter spheroides LPS/lipid-A derivatives) are antagonists in human cells but act as potent agonists with cells of other species. Data reported here indicate that structurally novel LPS from symbiotic, nitrogen-fixing bacteria found in association with the root nodules of legumes do not stimulate human monocytes to produce TNFalpha. Furthermore, LPS from one of these symbiotic bacterial species, Rhizobium sp. Sin-1, significantly inhibits the synthesis of TNFalpha by human cells incubated with Escherichia coli LPS. Rhizobium Sin-1 LPS exerts these effects by competing with E. coli LPS for binding to LPS-binding protein and by directly competing with E. coli LPS for binding to human monocytes. Rhizobial lipid-A differs significantly from previously characterized lipid-A analogs in phosphate content, fatty acid acylation patterns, and carbohydrate backbone. These structural differences define the rhizobial lipid-A compounds as a potentially novel class of LPS antagonists that might well serve as therapeutic agents for the treatment of Gram-negative sepsis.
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PMID:Rhizobium sin-1 lipopolysaccharide (LPS) prevents enteric LPS-induced cytokine production. 1219 96

BACKGROUND: The purpose of this study was to evaluate a possible association between serum phosphate levels and the incidence of cardiac arrhythmias in the early stages of sepsis. METHODS: We conducted a prospective, controlled study in the General Intensive Care Unit (GICU) of a university hospital. Sixteen patients with sepsis, but without any previous cardiac disease, were studied during their first 24 h in the GICU. Patients were connected to a continuous ECG recording device. Blood samples for serum phosphate level determinations were drawn during the first 6 h after admission to the unit. RESULTS: Ten of 16 patients had 21 episodes of atrial and ventricular arrhythmias. These patients had higher mean Apache II scores (20.2+/-6.2) than the six patients without arrhythmias (13.2+/-1.7; P<0.05) and significantly lower mean phosphate levels (0.73+/-0.16 vs. 1.02+/-0.32 mmol/l; P<0.03). No association was found between serum phosphate levels and mortality among patients with arrhythmias, or when all survivors (with and without arrhythmia) were compared to all non-survivors. CONCLUSIONS: The results indicate that patients with sepsis and low serum phosphate levels are at a greater risk of developing cardiac arrhythmias. We suggest that phosphate supplementation in the early stages of sepsis may prevent cardiac arrhythmias.
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PMID:Association between hypophosphatemia and cardiac arrhythmias in the early stages of sepsis. 1238 32

Lipopolysaccharide (LPS) may cause sepsis when it enters the blood circulation. The toxic moiety of LPS is the well-preserved lipid A part. Lipid A contains two phosphate groups attached to diglucosamine, which are crucial for the many biological activities of LPS. In previous studies we found that alkaline phosphatase (AP) was able to dephosphorylate LPS. To test whether LPS-dephosphorylation can be used for intervention during sepsis, we investigated the effects of Salmonella minnesota Re 595 LPS and its dephosphorylated counterpart monophosphoryl lipid A (MPLA) on macrophage activation in vivo and in vitro. Exposure of RAW264.7 cells to LPS induced high levels of tumor necrosis factor (TNFalpha) and nitric oxide (NO), whereas MPLA elicited no response. LPS in vivo induced a significant rise in TNFalpha levels in mice and an enhanced inflammatory cell influx in the lung, whereas MPLA did not. Having shown the relevance of this particular phosphate group of LPS, we subsequently explored the LPS-dephosphorylating ability of AP in different tissues, and the effect of AP administration in mice challenged with LPS. Histochemical data show that AP dephosphorylated native LPS in all tissues examined, whereas MPLA was not dephosphorylated. When mice received AP immediately after the LPS challenge, the survival rate was 100%, over 57% in the control group. We conclude that the enzymatic removal of phosphate groups from LPS by AP represents a crucial detoxification reaction, which may provide a new strategy to treat LPS-induced diseases like sepsis.
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PMID:Removal of phosphate from lipid A as a strategy to detoxify lipopolysaccharide. 1246 66

Pseudomonas aeruginosa is a pathogen that frequently causes acute lung injury, bacteremia and sepsis in critically ill patients. As tissue macrophages are a major producer of inflammatory mediators that contribute to septic physiology, and are essential for eliminating bacteria from the circulation, we investigated the role of tissue macrophages in the generation of both inflammatory and anti-inflammatory cytokines in septic shock by using our mouse model of P. aeruginosa pneumonia. To see the effects of tissue macrophage depletion, we intravenously injected dichloromethylene-diphosphonate (Cl2MDP)-encapsulating liposomes in mice. Two days after the liposome injection, we instilled cytotoxic P. aeruginosa (PA103) into the lung that disseminates and causes septic shock. After the infection, we collected blood and bronchoalveolar lavage fluids. The samples were then analyzed for TNF-alpha, MIP-2, and IL-10 concentration. We compared these results to control mice that received either liposomes without Cl2MDP or phosphate buffered saline alone. Plasma TNF-alpha, MIP-2, and IL-10 levels were significantly decreased in the tissue macrophage-depleted mice compared to the control groups of mice. Although depletion of tissue macrophages by Cl2MDP-liposome administration did not affect the severity of bacteremia or the survival of infected mice, these results imply that tissue macrophages have a major role in the production of both proinflammatory and anti-inflammatory cytokines in the circulation and in the causing septic physiology associated with P. aeruginosa pneumonia.
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PMID:Effects of Cl2MDP-encapsulating liposomes in a murine model of Pseudomonas aeruginosa-induced sepsis. 1260 29

The aim of this pilot study was to evaluate the incidence of hypophosphatemia and its association with clinical outcome in fulminant hepatic failure (FHF). Patients with FHF referred for orthotopic liver transplantation (OLT) between January, 1991 and May, 2002 were identified. FHF was defined as the development of coagulopathy and encephalopathy within 8 weeks of onset of jaundice. Demographic and laboratory data, including serum phosphate, calcium, magnesium, creatinine, and PT/INR were obtained from medical records. Clinical outcomes (death, OLT, or hepatic recovery) and associated morbidities (renal failure, bleeding, and sepsis) also were noted. Thirty-eight patients, 8 men and 30 women, aged 34 +/- 4 years, were included in the study. Hypophosphatemia (< 2.5 mg/dL) developed in 33 of 38 (87%) patients within 10 days of referral. Twelve patients (32%) died, 14 patients (37%) underwent OLT, and 12 patients (32%) recovered. The mean nadir serum phosphorus level was significantly lower in those who recovered compared with those who either died or required OLT (1.18 +/- 0.54 versus 1.79 +/- 1.00 mg/dL; P =.02). A trend toward lower mean serum phosphorus level also was noted in those who recovered compared with those who died (1.18 +/- 0.54 versus 1.96 +/- 1.35 mg/dL; P =.09). Serum phosphorus levels > 2.5 mg/dL was a predictor of mortality, and when used alone, was equivalent to the King's College Criteria. In conclusion, hypophosphatemia occurred frequently in patients with FHF. Lower serum phosphorus levels were observed in patients who recovered as compared with those who died or required OLT, and may be associated with recovery of hepatic function. The greater decline in serum phosphorus level in those who recover hepatic function may represent cellular use of phosphorus during hepatocyte regeneration.
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PMID:Serum phosphorus levels predict clinical outcome in fulminant hepatic failure. 1475 96


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