Urinary excretion of TNF receptors.
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Humans↗
Biomedical subjects
K R Gardiner
Publications and source records attributed to K R Gardiner.
Lactulose as an antiendotoxin in experimental colitis.
The efficacy of lactulose as an antiendotoxin was studied and the effect of lactulose or colistin on faecal flora was investigated in a hapten-induced rat model of colitis. Enteral administration of lactulose to rats with colitis was associated with a significant reduction in the systemic concentration of endotoxin (median (range) 5.4 (0-19.9) versus 23.7 (0-145.0) pg/ml in colitic rats treated with water; 4.6 (0-10.8) pg/ml in healthy animals). Enteral administration of colistin significantly reduced the faecal count of aerobic Gram-negative bacilli (median (range) 2.84 (1.40-8.43) versus 8.26 (4.50-10.40) log10 colony-forming units per g faeces after treatment with water) but not the faecal load of endotoxin. Patients with inflammatory bowel disease may benefit from enteral treatment with lactulose to prevent systemic endotoxaemia and/or with colistin to modify enteric bacteria.
Animals↗
Manipulation of the L-arginine-nitric oxide pathway in experimental colitis.
The role of the L-arginine-nitric oxide pathway in the pathogenesis of colonic inflammation was assessed using L-arginine and its competitive analogue N omega-nitro-L-arginine methyl ester (L-NAME) in a rat model of colitis. In the first study oral L-arginine 2 per cent (control: 3.4 per cent L-glycine) was administered with and without L-NAME 100 mg/l. Orally administered L-arginine increased colonic inflammation (P = 0.004) and decreased thymic weight (P = 0.0007). Addition of L-NAME reduced the colonic inflammation and prevented loss of body-weight (P < 0.04). In the second study L-NAME was administered orally in concentrations of 100, 200 and 500 mg/l (control: no L-NAME). L-NAME 500 mg/l reduced colonic inflammation and increased thymic weight and body-weight (P < 0.01). Thymic weight and body-weight correlated positively with the concentration of L-NAME administered orally (rs > or = 0.3, P = 0.04). L-NAME l g/l was administered topically as an enema (control: suspension agent). Topical L-NAME reduced colonic inflammation and increased thymic weight (P < 0.05). These results suggest that the L-arginine-nitric oxide pathway mediates colonic inflammation in this model.
Administration, Oral↗
Efficacy of glutamine-enriched enteral nutrition in an experimental model of mucosal ulcerative colitis.
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Animals↗
Endotoxaemia and cytokine production in experimental colitis.
Systemic endotoxaemia is a well recognized feature of inflammatory bowel disease but its pathogenic role remains uncertain. This study examined plasma endotoxin and cytokine concentrations and the acute-phase protein response in a hapten-induced model of experimental colitis. On days 2, 8 and 14 after induction of colitis with trinitrobenzenesulphonic acid in ethanol (TNBS-E), plasma endotoxin, immunoglobulin (Ig) G and IgM endotoxin-core antibody (EndoCAb), tumour necrosis factor (TNF), interleukin (IL) 6 and alpha 2-macroglobulin (alpha 2M) concentrations and colon macroscopic inflammation score were determined. At all time points there was significant colonic inflammation when compared with control values (P < 0.0001). Animals treated with TNBS-E had raised concentrations of endotoxin at all time points (P < 0.04). In TNBS-E-treated animals EndoCAb concentrations were reduced on day 2 (P < 0.0001) and later increased. There were increases in IL-6 and alpha 2M concentrations in TNBS-E-treated animals but no significant change in TNF concentrations. Endotoxin concentrations correlated with macroscopic inflammation score, IL-6 and alpha 2M concentrations. There was a less consistent correlation between EndoCAb concentrations and these parameters. These results suggest that endotoxin is a mediator of the systemic response in this model of experimental colitis.
Animals↗
Reduced intestinal absorption of arginine during sepsis.
OBJECTIVE: To investigate the effect of sepsis on the intestinal absorption of arginine. DESIGN: Controlled, nonintervention study. SETTING: Surgical research laboratories of Sinai Hospital of Baltimore. SUBJECTS: Male Sprague-Dawley rats. INTERVENTIONS: Experimental sepsis induced by cecal ligation and puncture or intraperitoneal injection of lipopolysaccharide. MEASUREMENTS AND MAIN RESULTS: Sepsis assessed by peritoneal and blood cultures. Intestinal absorption estimated by measuring the transfer of 3H-arginine by everted jejunal sacs prepared from septic and control animals (n = 6 per group) at multiple time points after the induction of sepsis (6, 12, 24, 48, and 72 hrs after cecal ligation and puncture; 6 and 12 hrs after intraperitoneal injection of lipopolysaccharide). Induction of peritonitis in the rat by cecal ligation and puncture significantly reduced the in vitro uptake of arginine by everted jejunal sacs at 12, 24, and 48 hrs after laparotomy. Arginine transfer by everted jejunal sacs was also significantly reduced in rats as early as 6 hrs after intraperitoneal injection of endotoxin (endotoxin 273 +/- 14; saline 377 +/- 14 nmol/sac/hr). Data are expressed as mean +/- SEM. Recovery from sepsis was associated with normalization of arginine transfer by intestinal sacs. CONCLUSIONS: Experimental sepsis, induced by either cecal ligation and puncture or intraperitoneal injection of lipopolysaccharide, resulted in impaired intestinal amino acid uptake. Impaired intestinal arginine absorption may explain the lack of benefit of enteral, compared with parenteral, arginine therapy on survival from a septic insult.
Animals↗
Significance of systemic endotoxaemia in inflammatory bowel disease.
Quantitative and qualitative disturbances in faecal flora suggest a role for enteric bacteria and their products in the pathogenesis of inflammatory bowel disease (IBD). This study investigated the hypothesis that systemically circulating endotoxins are of pathogenic significance in IBD by measuring antibody, cytokine, and acute phase protein responses. Systemic endotoxaemia was found in 88% patients with ulcerative colitis (n = 25) and 94% with Crohn's disease (n = 31) during clinical relapse. Systemic endotoxaemia correlated positively with anatomic extent and clinical activity of ulcerative colitis. Circulating tumour necrosis factor (TNF) was detected in 40% of patients with ulcerative colitis and 45% with Crohn's disease. Plasma TNF concentrations correlated with clinical and laboratory measures of disease activity and were associated with a surgical outcome to the disease episode. Plasma soluble TNF receptor p55 concentration correlated positively with disease activity and endotoxin core antibody concentrations. Plasma IgG endotoxin core antibody concentrations were significantly increased in patients with Crohn's disease and correlated with systemic endotoxaemia. The presence of systemic endotoxaemia, its correlation with disease activity, disease extent, and endotoxin core antibody concentration and the detection of circulating TNF and soluble TNF receptors all support a pathogenic role for endotoxins in IBD.
Adolescent↗
Colitis and colonic mucosal barrier dysfunction.
Trauma, infection, neoplasia, and inflammation can all disrupt the intact intestinal mucosal barrier to intraluminal bacteria and bacterial antigens. This study investigated the relation between colonic inflammation and colonic mucosal barrier function in three experimental models of colitis. There were significantly increased systemic endotoxin concentrations in rats with acetic acid (7.5 (1.7-119.5) pg/ml), ethanol (13.7 (0-111.2) pg/ml), and hapten induced (14.4 (5-31.1) pg/ml) colitis compared with saline controls (3.3 (0-13.7) pg/ml). Data expressed as median (range). There were significant correlations between the systemic endotoxin concentration and both the severity of colitis and of illness in acetic acid induced colitis. A significant increase in colonic permeability to 14C-polyethylene glycol was shown in rats with acetic acid (3.42 (1.36-5.63)%) and hapten induced colitis (2.86 (1.03-8.10)%) compared with saline controls (1.20 (0.67-1.36)%). Data expressed as median (range) of percentage of the intracolonic bolus excreted in urine. There was a significant positive correlation between the severity of colitis and % colonic permeability to 14C-polyethylene glycol. This and other studies provide evidence that mucosal barrier dysfunction is a feature of colitis irrespective of aetiology or species. Such barrier dysfunction may be responsible for the systemic inflammatory response and complications seen in patients with inflammatory bowel disease.
Acetates↗
Failure of intestinal amino acid absorptive mechanisms in sepsis.
BACKGROUND: Sepsis has been shown to impair the barrier function and metabolism of the intestine. This study was done to investigate the effect of sepsis on intestinal absorption of proline, leucine, glutamic acid, and aminoisobutyric acid. STUDY DESIGN: Rats (six per group) were studied 24 hours after cecal ligation and puncture (CLP) or six hours after intraperitoneal injection of lipopolysaccharide (LPS). Controls underwent sham laparotomy or saline solution injection. Four 7-cm everted proximal jejunal sacs were prepared from each rat and filled with 800 microL Krebs' bicarbonate buffer containing 100 mumol/L of amino acid. Paired sacs (septic and control) were incubated at 37 degrees C in flasks containing the same solution trace labeled with 3H containing the same solution trace labeled with 3H amino acid. Sac contents were aspirated 60 minutes later and amino acid uptake was determined by scintillation counting. RESULTS: Twenty-four hours after CLP and six hours after LPS administration there was significant impairment in the intestinal absorption of all amino acids studied. Absorption of glutamic acid was the least affected, followed by leucine, aminoisobutyric acid, and proline. CONCLUSIONS: Sepsis impairs the intestinal absorption of amino acids. The magnitude of this defect in absorption differed with the amino acid studied, suggesting that not all transport systems were affected equally. This differential response of transport systems to sepsis appears to be the inverse of what is observed after a period of starvation.
Amino Acids↗
Thyroidectomy for large multinodular colloid goitre.
Between 1983 and 1993 a total of 474 patients underwent thyroidectomy in one surgical unit. In 64 (14%) of these, a multinodular colloid goitre weighing more than 100 g was resected. Preoperative symptoms in this group of patients with large goitres included respiratory difficulty (42%) and dysphagia (22%) whilst 22% demonstrated distension of the veins of the neck or anterior chest wall. Plain radiography revealed evidence of tracheal deviation in 70% of patients and tracheal compression in 42%. Total thyroidectomy was carried out in 47 patients and unilateral total lobectomy in 11; six patients underwent completion thyroidectomy for massive recurrent goitre following previous resection. There was no perioperative mortality. Complications included permanent unilateral vocal cord paralysis in two patients (1.7% of recurrent laryngeal nerves at risk), permanent hypoparathyroidism in two (3.1%) and temporary emergency tracheostomy in one individual. We advocate total resection for patients with large multinodular colloid goitre.
Goiter, Nodular↗
Peritonitis impairs intestinal absorption of proline and leucine in the rat.
Systemic sepsis is associated with reduced mesenteric blood flow and impairment of metabolic and barrier functions of the small intestine. A study was performed in the rat to investigate the effect of sepsis induced by caecal ligation and double puncture on intestinal absorption of leucine and proline in vivo. Absorption was studied 24 h after caecal ligation and puncture by measuring intestinal disappearance and circulatory appearance of intraluminal 3H-labelled amino acid over a 60-min study period. Peritonitis resulted in a significant increase relative to controls in the mean (s.e.m.) percentage of leucine (67.2(3.6) versus 18.0(3.5), P < 0.001) and proline (64.7(6.0) versus 15.1(3.7), P < 0.001) remaining within the small intestine. There were significant decreases in portal venous and femoral arterial concentrations of leucine and proline in animals with sepsis. Intestinal amino acid absorption is impaired in this model.
Animals↗
Predictive value of soluble immunological mediators in neonatal infection.
1. Infection in the neonatal period is difficult to diagnose and is a significant cause of morbidity and mortality in preterm infants. 2. We investigated prospectively the predictive value of plasma measurement of bacterial endotoxin (lipopolysaccharide), tumour necrosis factor-alpha, interleukin-6, interleukin-8, intercellular adhesion molecule-1 and C-reactive protein in 60 consecutive newborn infants suspected of having neonatal infection. Plasma samples were taken at the time of acute clinical deterioration. Sixty-two cord blood samples were studied as controls taken at elective Caesarean section. 3. Forty-three infants had confirmed infections, 25 with positive blood cultures. Tumour necrosis factor-alpha and bacterial endotoxin levels were not significantly elevated over controls, whereas interleukin-6, interleukin-8 and intercellular adhesion molecule-1 levels were all significantly increased in the infected group compared with controls (all P < 0.001). 4. Increased plasma intercellular adhesion molecule-1 levels were a highly sensitive (88%) indicator of clinical infection and were independent of C-reactive protein. Use of these two assays in combination improved the diagnostic sensitivity to 95% and gave a negative predictive value of 97%. addition of interleukin-6 or interleukin-8 measurements failed to further significantly enhance the prediction of infection. 5. Measurement of intercellular adhesion molecule-1 level may have a clinical role in rapidly confirming, or predicting, the likely diagnosis in cases of suspected neonatal infection.
Bacterial Infections↗
Class II major histocompatibility complex antigen expression on peripheral blood monocytes in patients with inflammatory bowel disease.
Macrophage major histocompatibility complex (MHC) class II antigen expression is associated with defective antigen presentation to T lymphocytes in animals and is predictive of patient outcome after major trauma or sepsis. In this study, class II antigen (HLA-DR and DQ) expression on peripheral blood monocytes was investigated in patients with inflammatory bowel disease in relation to disease activity and outcome. The percentage positivity and fluorescent intensity of expression of HLA-DR and DQ antigens on monocytes were determined in whole blood samples using dual colour immunofluorescence labelling and flow cytometry. Disease activity was assessed using clinical and laboratory indices. There was no significant difference in percentage positivity or fluorescent intensity of class II antigen expression between patients with Crohn's disease, those with ulcerative colitis, and healthy volunteers. The percentage of monocytes displaying HLA-DR positivity was significantly decreased in patients with active ulcerative colitis (active %: 49.5 (5.6); inactive %: 78.9 (6.9); p = 0.01). Data expressed as mean (SEM). In patients requiring surgical resection of diseased bowel, the percentage of monocytes displaying HLA-DR positivity (51.9 (4.0) %) was significantly reduced compared with patients receiving medical treatment alone (81.1 (3.5) %; p < 0.001). Reduced monocyte HLA-DR expression is therefore associated with disease activity and seems to predict outcome in patients with inflammatory bowel disease.
Adolescent↗
Enteral and parenteral anti-endotoxin treatment in experimental colitis.
Systemic endotoxemia has been described in ulcerative colitis and Crohn's disease and shown to correlate positively with disease activity and the extent of intestinal ulceration. This study evaluated the efficacy of antibiotic and anti-endotoxic treatment in reducing systemic endotoxemia in a hapten-induced rat model of colitis. Enteral administration of paromomycin was associated with a significant reduction in systemic endotoxin concentrations (7.4 +/- 1.2 pg/ml) when compared with controls (39.8 +/- 12.6 pg/ml; p = 0.032). Intravenous injection of taurolidine was also found to significantly reduce systemic endotoxemia (3.1 +/- 1.3 pg/ml) in comparison with controls receiving saline injection (17.5 +/- 4.2 pg/ml; p = 0.008). Enteral neomycin, parenteral polymyxin or metronidazole and cefuroxime were ineffective anti-endotoxin treatments in this model. Enteral paromomycin or parenteral tauro-lidine therapy are potential methods of preventing and treating systemic endotoxemia in patients with inflammatory bowel disease.
Animals↗
Colonic bacteria and bacterial translocation in experimental colitis.
The indigenous intestinal flora and an intact mucosa are vital components of body defences against luminal pathogenic bacteria. Disruption of these defences in inflammatory bowel disease may permit bacterial translocation and contribute to disease severity. Support for this hypothesis comes from this study of a hapten-induced rat model of colitis. Induction of colitis was associated with a significantly increased colonic Gram-negative aerobic bacilli count. The results, expressed as log10 [colony-forming units per gram tissue] were: colitic 6.97-8.86 versus control 4.90-6.69 (P < 0.05). Colitis was also associated with a decreased Gram-positive cocci count at 4.00-8.04 versus control 6.45-8.30 (P < 0.05). Bacteria translocated to the mesenteric lymph nodes in five of eight colitic rats (P = 0.01), to the spleen in four (P = 0.04) and to the liver in five (P = 0.01) but to these organs in none of the eight control animals. There was a positive correlation between the severity of colonic inflammation and extent of bacterial translocation in colitic animals (rs = 0.86, P = 0.007).
Animals↗
Sepsis impairs gut amino acid absorption.
Sepsis has been shown to adversely affect the barrier and metabolic functions of the small intestine as well as to reduce mesenteric blood flow and cause histologic damage. However, the effect of sepsis on gut absorptive function has been largely ignored. In this study, intestinal absorption of arginine and an amino acid analogue, aminoisobutyric acid, was studied using in vivo and in vitro techniques in an experimental model of sepsis. In vivo studies showed a significant impairment in the absorption of both amino acids from the intestinal lumen 24 and 72 hours after cecal ligation and puncture. Uptake of these amino acids by everted gut sacs prepared from septic animals was also significantly reduced. This reduction in absorptive capacity of the gut may limit the ability of enteral feeding alone to supply nutritional requirements during sepsis and may also contribute to the associated morbidity and mortality.
Aminoisobutyric Acids↗
Adsorbents as antiendotoxin agents in experimental colitis.
The intestinal mucosa protects the body from a large reservoir of intraluminal pathogenic bacteria and endotoxins. This mucosal barrier is disrupted by the inflammation and ulceration of inflammatory bowel disease and may permit the absorption of toxic bacterial products. Systemic endotoxaemia has been demonstrated in ulcerative colitis and Crohn's disease and correlates with the extent and activity of disease. In this study the efficacy of absorbents as antiendotoxin agents in a hapten induced rat model of colitis is investigated. Induction of colitis was associated with systemic endotoxaemia. Enteral administration of terra fullonica and kaolin, but not of charcoal, significantly reduced systemic endotoxaemia (terra fullonica 4.2 (1.40) pg/ml; kaolin 5.29 (1.86) pg/ml; charcoal 32.7 (16.6) pg/ml; water 39.8 (12.6) pg/ml). Data expressed as mean (SE). With increasing severity of colitis, there was a decreasing ability of adsorbent therapy (terra fullonica) to control systemic endotoxaemia. Enteral administration of adsorbents controls gut derived systemic endotoxaemia in experimental colitis in animals and may be a useful antiendotoxin treatment in patients with inflammatory bowel disease.
Adsorption↗