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Query: UMLS:C0036690 (sepsis)
 59,461 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Recent studies revealed that vasopressinergic neurons have a high content of cys-leukotriene C(4) (LTC(4)) synthase, a critical enzyme in cys-leukotriene synthesis that may play a role in regulating vasopressin secretion. This study investigates the role of this enzyme in arginine vasopressin (AVP) release during experimentally induced sepsis. Male Wistar rats received an i.c.v. injection of 3-[1-(p-chlorobenzyl)-5-(isopropyl)-3-tert-butylthioindol-2-yl]-2, 2-dimethylpropanoic acid (MK-886) (1.0 microg/kg), a leukotrienes (LTs) synthesis inhibitor, or vehicle, 1 h before cecal ligation and puncture (CLP) or sham operation. In one group of animals the survival rate was monitored for 3 days. In another group, the animals were decapitated at 0, 4, 6, 18 and 24 h after CLP or sham operation, and blood was collected for hematocrit, serum sodium and nitrate, plasma osmolality, protein and AVP determination. A third group was used for blood pressure measurements. The neurohypophysis was removed for quantification of AVP content, and the hypothalamus was dissected for LTC(4) synthase analysis by Western blot. Mortality after CLP was reduced by the central administration of MK-886. The increase in plasma AVP levels and hypothalamus LTC(4) synthase content in the initial phase of sepsis was blocked, whereas the decrease in neurohypophyseal AVP content was partially reversed. Also the blood pressure drop was abolished in this phase. The increase of serum nitric oxide and hematocrit was reduced, and the decrease in plasma protein and osmolality was not affected by the LTs blocker. In the final phase of sepsis, the plasma AVP level and the hypothalamic LTC(4) synthase content were at basal levels. The central administration of MK-886 increased the hypothalamic LTC(4) synthase content but did not alter the plasma and neurohypophysis AVP levels observed, or the blood pressure during this phase. These results suggest that the central LTs are involved in the vasopressin release observed during sepsis.
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PMID:Blocking central leukotrienes synthesis affects vasopressin release during sepsis. 1928 13

In a previous study, we concluded that overproduction of nitric oxide (NO) by inducible nitric oxide synthase (iNOS) in the late phase of sepsis prevents hypothalamic activation, blunts vasopressin secretion and contributes to hypotension, irreversible shock and death. The aim of this follow-up study was to evaluate if the same neuronal activation pattern happens in brain structures related to cardiovascular functions. Male Wistar rats received intraperitoneal injections of aminoguanidine, an iNOS inhibitor, or saline 30 min before cecal ligation and puncture (CLP) or sham surgeries. The animals were perfused 6 or 24h after the surgeries and the brains were removed and processed for Fos immunocytochemistry. We observed an increase (P<0.001) in c-fos expression 6h after CLP in the area postrema (AP), nucleus of the tractus solitarius (NTS), ventral lateral medulla (VLM), locus coeruleus (LC) and parabrachial nucleus (PB). At 24h after CLP, however, c-fos expression was strongly decreased in all these nuclei (P<0.05), except for the VLM. Aminoguanidine reduced c-fos expression in the AP and NTS at 6h after CLP, but showed an opposite effect at 24h, with an increase in the AP, NTS, and also in the VLM. No such effect was observed in the LC and PB at 6 or 24h. In all control animals, c-fos expression was minimal or absent. We conclude that in the early phase of sepsis iNOS-derived NO may be partially responsible for the activation of brain structures related to cardiovascular regulation. During the late phase, however, this activation is reduced or abolished.
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PMID:Blocking systemic nitric oxide production alters neuronal activation in brain structures involved in cardiovascular regulation during polymicrobial sepsis. 1942 22

This review aims to provide physicians with an overview of the potential of procalcitonin to guide antibiotic therapy in respiratory tract infections and in sepsis. Knowledge of the strengths and weaknesses of procalcitonin are prerequisites for a rational and safe use in clinical routine. In most infections a true gold standard for diagnosis does not exist, therefore physicians must remain sceptical towards observational studies evaluating procalcitonin. Interpretation of procalcitonin levels must always include the clinical setting and knowledge of assay characteristics, particularly the setting of specific cut-off ranges and functional assay sensitivities. Highly sensitive procalcitonin measurements, embedded in a clearly defined setting and prospectively validated with clinical algorithms were repeatedly effective in markedly reducing the (over)-utilisation of antimicrobial therapy. Today, this concept has been proven for lower respiratory tract infections and in pilot studies for meningitis and critically ill patients with sepsis. The higher the absolute risk for adverse outcome of a patient, the more cautious physicians must remain and empirical antibiotic therapies must be considered despite initial low procalcitonin levels at the initial presentation. In these patients a procalcitonin-guided shortening of antibiotic courses seems appropriate. The prognostic utility of initial procalcitonin measurement in respiratory tract infections is suboptimal. Other biomarkers including cortisol, human growth hormone and prohormones from adrenomedullin and vasopressin ("copeptin") have a superior predictive potential to estimate the risk for short and long term mortality and other adverse outcomes in different diseases. An accurate prognostic assessment has the potential to optimise the management of patients and the allocation of our limited health care resources by lowering unnecessary hospitalisations and associated cost. Future intervention studies must prove if these biomarkers indeed improve clinical decision making and thus the overall medical management of patients.
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PMID:Procalcitonin and other biomarkers to improve assessment and antibiotic stewardship in infections--hope for hype? 1952 89

We report a case of a 65-year-old lady who presented with acute confusion and profound hyponatraemia (plasma sodium of 97 mmol/L). Five years earlier she had developed sepsis and was found to have hyponatraemia, thought to be due to syndrome of inappropriate antidiuretic hormone secretion. The patient was lost to follow-up. The patient was covered with steroids and investigations confirmed primary adrenal failure with flat response of cortisol to adrenocorticotropic hormone (ACTH) stimulation and very high level of ACTH. Adrenal auto-antibodies were negative and a computed tomography of the adrenals showed bilateral adrenal calcifications, suggestive of previous haemorrhage or infarction. Bilateral adrenal calcification due to haemorrhage/infarction usually does not present with severe hyponatraemia; however, adrenal insufficiency should be excluded in all cases of severe hyponatraemia. In suspected cases, patients should be treated with steroids, even when symptoms or signs are absent, while results of investigations are awaited.
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PMID:An unusual case of profound hyponatraemia and bilateral adrenal calcifications. 1979 4

Acute renal failure (ARF) is frequently associated with polyuria and urine concentration defects and it is a severe complication of sepsis because it increases the mortality rate. Inhibition of NF-kappaB activation has been suggested to provide a useful strategy for the treatment of septic shock. However, the impact on sepsis-induced ARF is still unclear. Therefore, we examined the effect of pyrrolidine dithiocarbamate (PDTC) and of small interfering RNA (siRNA) silencing NF-kappaB p50/p105 on sepsis-induced downregulation of vasopressin V(2) receptors and aquaporin (AQP)-2 channels using a cecal ligation and puncture (CLP) mouse model. CLP caused a time-dependent downregulation of renal vasopressin V(2) receptor and of AQP2 expression without alterations in plasma vasopressin levels. Renal activation of NF-kappaB in response to CLP was attenuated by PDTC pretreatment, which also attenuated the downregulation of V(2) receptor and AQP2 expression. Furthermore, a strong nuclear staining for the NF-kappaB p50 subunit throughout the whole kidney in response to CLP was observed. siRNA against NF-kappaB p50 attenuated the CLP-induced nuclear translocation of the p50 subunit and the CLP-induced downregulation of V(2) receptor and AQP2 expression. Additionally, PDTC and siRNA pretreatment inhibited the CLP-induced increase in renal TNF-alpha and IL-1beta concentration and NOS-2 mRNA abundance. Moreover, PDTC and siRNA pretreatment ameliorated CLP-induced hypotension and ARF. Our findings suggest that NF-kappaB activation is of importance for the downregulation of AQP2 channel and vasopressin V(2) receptor expression during sepsis. In addition, our data indicate that NF-kappaB inhibition ameliorates sepsis-induced ARF.
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PMID:Inhibition of NF-kappaB ameliorates sepsis-induced downregulation of aquaporin-2/V2 receptor expression and acute renal failure in vivo. 1982 75

Severe sepsis and septic shock have been part of intensivists' major challenges since the birth of the specialty. This clinical picture is followed by the development of a multiple organ failure syndrome. Our working hypothesis today is that multiple organ failures develop due to a systemic intravascular malignant inflammatory response. This article proposes an alternative understanding of the problem based on some of the recent data and understandings of non glycemic, non insulinemic endocrine dysfunction in severe sepsis and septic shock. Our presentation of selected literature supports the presence of a decreased production and activity in steroids, thyroid hormones, growth hormone, vasopressin and prolactin in septic shock. These hormones have important and synergistic functions. The disruption of which can lead to multiple organ failure in septic shock. Developing research focusing on the broad hypothalamic and pituitary functions could improve our understanding of metabolic derangements in severe sepsis and septic shock and thus provide new therapeutic options. These new therapies based on hormonal replacement are currently available at low cost and could improve outcomes.
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PMID:Is pituitary failure the real therapeutic target in septic shock? 1985 83

Copeptin denominates the C-terminal fragment of the vasopressin (AVP) precursor hormone. Circulating copeptin levels reflect the activity of the AVP system and correlate closely with plasma osmolality. The measurement of stimulated plasma AVP levels is crucial in the differential diagnosis of diabetes insipidus, particularly the characterization of partial forms, and is used to diagnose primary polydipsia. However, determination of AVP levels is technically demanding, and validated assays are not readily available for clinical routine. Recently, a reliable sandwich immunoassay for measurement of serum or plasma copeptin levels has been introduced. Assaying stimulated copeptin levels will be helpful in the differential diagnosis of diabetes insipidus. Recent studies suggest that measurement of copeptin, once the assay is commercially available, might prove useful in the workup of hyponatremic disorders. Moreover, copeptin has been found to be a prognostically relevant biomarker in a variety of illnesses such as sepsis, shock, pneumonia, acute exacerbation of COPD, heart failure, and myocardial infarction.
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PMID:[Copeptin: diagnostic parameter, biomarker, or both?]. 1988 89

Sepsis is physiologically viewed as a proinflammatory and procoagulant response to invading pathogens. There are three recognized stages in the inflammatory response with progressively increased risk of end-organ failure and death: sepsis, severe sepsis, and septic shock. Patients with cirrhosis are prone to develop sepsis, sepsis-induced organ failure, and death. There is evidence that in cirrhosis, sepsis is accompanied by a markedly imbalanced cytokine response ("cytokine storm"), which converts responses that are normally beneficial for fighting infections into excessive, damaging inflammation. Molecular mechanisms for this excessive proinflammatory response are poorly understood. In patients with cirrhosis and severe sepsis, high production of proinflammatory cytokines seems to play a role in the worsening of liver function and the development of organ/system failures such as shock, renal failure, acute lung injury or acute respiratory distress syndrome, coagulopathy, or hepatic encephalopathy. In addition, these patients may have sepsis-induced hyperglycemia, defective arginine-vasopressin secretion, adrenal insufficiency, or compartmental syndrome. In patients with cirrhosis and spontaneous bacterial peritonitis (SBP), early use of antibiotics and intravenous albumin administration decreases the risk for developing renal failure and improves survival. There are no randomized studies that have been specifically performed in patients with cirrhosis and severe sepsis to evaluate treatments that have been shown to improve outcome in patients without cirrhosis who have severe sepsis or septic shock. These treatments include recombinant human activated C protein and protective-ventilation strategy for respiratory failure. Other treatments should be evaluated in the cirrhotic population with severe sepsis including the early use of antibiotics in "non-SBP" infections, vasopressor therapy, hydrocortisone, renal-replacement therapy and liver support systems, and selective decontamination of the digestive tract or oropharynx.
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PMID:Severe sepsis in cirrhosis. 2037 75

Central pontine myelinolysis (CPM) has been described in alcoholic patients and in the aftermath of rapid correction of chronic hyponatraemia. We describe a case of CPM occurring secondary to nephrogenic diabetes insipidus (DI), which developed as a consequence of severe hypokalaemia. A 63-year-old man with alcohol dependence was admitted to hospital with severe pulmonary sepsis and type 1 respiratory failure. On admission, he had euvolaemic hyponatraemia of 127 mmol/L, consistent with a syndrome of inappropriate antidiuretic hormone secondary to his pneumonia. Following admission, his plasma potassium dropped from 3.2 to a nadir of 2.3 mmol/L. Mineralocorticoid excess, ectopic adrenocorticotrophic hormone production and other causes of hypokalaemia were excluded. The hypokalaemia provoked significant hypotonic polyuria and a slow rise in plasma sodium to 161 mmol/L over several days. Plasma glucose, calcium and creatinine were normal. The polyuria did not respond to desmopressin, and subsequent correction of his polyuria and hypernatraemia after normalization of plasma potassium confirmed the diagnosis of nephrogenic DI due to hypokalaemia. The patient remained obtunded, and the clinical suspicion of osmotic demyelination was confirmed on magnetic resonance imaging. The patient remained comatose and passed away 10 days later. This is the first reported case of nephrogenic DI resulting in the development of CPM, despite a relatively slow rise in plasma sodium of less than 12 mmol/L/24 h. Coexisting alcohol abuse, hypoxaemia and hypokalaemia may have contributed significantly to the development of CPM in this patient.
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PMID:Central pontine myelinolysis secondary to hypokalaemic nephrogenic diabetes insipidus. 1994 Feb 3

Impaired arginine vasopressin (AVP) synthesis and release by the neurohypophyseal system, which includes the neurohypophysis and magnocellular neurons of the paraventricular and supraoptic nuclei, have been postulated in septic shock, but changes in this system have never been assessed in human septic shock, and only partially experimentally. We investigated AVP synthesis and release by the neurohypophyseal system in 9 patients who died from septic shock and 10 controls, and in 20 rats with fecal peritonitis-induced sepsis and 8 sham-operation controls. Ten rats died spontaneously from septic shock, and the others were sacrificed. In patients with septic shock, as in rats that died spontaneously following sepsis induction, AVP immunohistochemical expression was decreased in the neurohypophysis and supraoptic magnocellular neurons, whereas it was increased in the paraventricular magnocellular neurons. No significant change was observed in AVP messenger RiboNucleic Acid (mRNA) expression assessed by in situ hybridization in either paraventricular or supraoptic magnocellular cells. This study shows that both in human and experimental septic shock, AVP posttranscriptional synthesis and transport are differently modified in the magnocellular neurons of the supraoptic and paraventricular nuclei. This may account for the inappropriate AVP release in septic shock and suggests that distinct pathogenic mechanisms operate in these nuclei.
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PMID:Vasopressin synthesis by the magnocellular neurons is different in the supraoptic nucleus and in the paraventricular nucleus in human and experimental septic shock. 2001 89


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