Recent Leaky Gut Syndrome (increased intestinal permeability) Research

 

Transplantation 2001 Apr 27;71(8):1069-75
Sex and ethnicity may chiefly influence the interaction of fluconazole with calcineurin inhibitors.
Mathis AS, DiRenzo T, Friedman GS, Kaplan B, Adamson R. Department of Pharmacy Practice and Administration, College of Pharmacy, Rutgers University, Piscataway, New Jersey 08854, USA. smathis@sbhcs.com
BACKGROUND: Calcineurin inhibitors (CNI) and azole antifungal agents have been reported to interact in a disparate manner. The azole dose and route and the level of involvement of the liver and intestines have been implicated, although data are limited. A significant interaction may result in CNI toxicity, and withdrawal of the azole may result in subtherapeutic CNI concentrations. Fluconazole, available in both intravenous and oral formulations, is commonly used in transplant recipients and is ideal for determining the presence of a disparate effect on CNI concentrations. We retrospectively investigated the interaction of CNIs with fluconazole, evaluating CNI blood troughs corrected for daily CNI dose, the factors influencing the interaction, and the effect on clinical outcomes in renal and simultaneous pancreas kidney transplant recipients. METHODS: Twenty-eight patients received a CNI and fluconazole during the calendar year 1999, but only 19 patients had documented CNI blood troughs and outpatient follow-up. There were 25 episodes of use in the 19 included patients. CNI blood troughs were evaluated for changes induced by fluconazole, given by both routes, and clinical outcomes were tracked. RESULTS: Data demonstrated both intravenous and oral fluconazole alter CNI blood concentrations. Two metabolic patterns were observed, and we termed these convergent and divergent. Divergent metabolizers did not have significant interaction (n=5), and convergent metabolizers did have a significant interaction (n=15). One patient had a divergent episode after a previous convergent episode. The main contributors to the lack of interaction appeared to be female sex and African American ethnicity. Additionally, tacrolimus levels were significantly more affected than cyclosporine, during and after fluconazole administration. No patient experienced nephrotoxicity or cellular rejection related to antifungal therapy. CONCLUSIONS: Oral and intravenous fluconazole appear to increase oral CNI trough concentrations to a similar extent even after adjusting for daily calcineurin dose. These interactions appear to be chiefly influenced by sex and ethnicity. Further prospective study is necessary to clarify this issue.
PMID: 11374405

Pediatrics 2001 Feb;107(2):293-8
Comment in:

Pediatrics. 2001 Feb;107(2):404-5
Fluconazole for prophylaxis against candidal rectal colonization in the very low birth weight infant.
Kicklighter SD, Springer SC, Cox T, Hulsey TC, Turner RB. Wake Medical Center, Raleigh, North Carolina 27620, USA. skicklighter@wakemed.org
BACKGROUND: Candidal infections are an important cause of morbidity and mortality in the very low birth weight (VLBW) infant. Current intervention focuses on treatment once candidal septicemia is either suspected or diagnosed. Studies have suggested that colonization with candidal species is an important risk factor for subsequent infection. OBJECTIVE: To determine whether prophylactic fluconazole for the first 28 days of life results in a decreased incidence of candidal colonization in the VLBW infant. RESEARCH DESIGN: Prospective, randomized, controlled, intention-to-treat design comparing prophylaxis with fluconazole versus placebo for the first 28 days of life. SETTING: A tertiary level intensive care nursery in a major teaching hospital in Charleston, South Carolina. PATIENTS: One hundred three infants with a birth weight of <1500 g, either inborn or outborn, who were admitted to the intensive care nursery between January 1998 and February 1999. METHODS: Infants were enrolled within 72 hours of life with rectal cultures performed on the day of randomization (DOR), as well as day of life (DOL) 7, 14, and 28. Those infants with a birth weight of <1250 g had additional cultures on DOL 35, 49, and 56. Cultures were plated on selective media for isolation of candidal organisms. Infants were randomized to receive either fluconazole (6 mg/kg) or placebo on the DOR. Subsequent doses were given every 72 hours until DOL 7 and then every 24 hours until DOL 28. Medication was given either intravenously or by feeding tube once the infant had been gavage feeding for a 48-hour period without feeding intolerance. Aspartate aminotransferase and alanine aminotransferase levels were obtained on DOR and DOL 7, 14, and 28 to assess for fluconazole toxicity. The minimal inhibitory concentration to fluconazole was determined for all positive cultures to assess the development of resistance. RESULTS: The infants who received fluconazole (n = 53) and placebo (n = 50) had no statistical difference in the major risk factors known to increase the chances of candidal septicemia in the VLBW infant. Rectal colonization by candidal species was detected in 8 of the 53 fluconazole-treated patients (15.1%) and in 23 of the 50 infants treated with placebo (46%). Fluconazole significantly reduced rectal colonization from DOL 14 through DOL 56 in all infants with a birth weight of <1250 g, and from DOL 14 through DOL 56 in all infants with a birth weight of 1250 to 1500 g. Alanine aminotransferase levels were higher in the fluconazole versus the placebo-treated group on DOL 14 (18.1 IU/L vs 15 IU/L), but no clinically significant abnormalities were observed. Candida albicans was the most common species isolated. There was no increase in species of Candida noted for their intrinsic resistance to fluconazole, and there was no statistically significant difference in the minimal inhibitory concentrations to fluconazole for all C albicans isolates in either group at any period. CONCLUSION: Prophylactic administration of fluconazole to the VLBW infant for the first 28 days of life is safe and results in a decreased risk of rectal colonization by candidal species. Larger studies to determine the effect of prophylaxis on candidal septicemia and development of resistance in such a selective high-risk group are warranted before initiation of routine prophylaxis.fluconazole, very low birth weight infant, prophylaxis, candidal sepsis, sensitivities to fluconazole.

Publication Types:

Clinical trial

Randomized controlled trial

PMID: 11158461

Bone Marrow Transplant 2000 Nov;26(9):993-7
Fungal colonization and invasive fungal infections following allogeneic BMT using metronidazole, ciprofloxacin and fluconazole or ciprofloxacin and fluconazole as intestinal decontamination.
Trenschel R, Peceny R, Runde V, Elmaagacli A, Dermoumi H, Heintschel von Heinegg E, Muller KD, Schaefer UW, Beelen DW. Department of Bone Marrow Transplantation, University Hospital Essen, Germany.
Invasive fungal infections (IFI) are increasingly diagnosed in patients undergoing allogeneic bone marrow transplnatation (BMT). We have previously shown that the addition of metronidazole to ciprofloxacin for gastrointestinal bacterial decontamination significantly reduces the incidence of grades II-IV aGVHD by reduction of the anaerobic intestinal bacterial flora. Here, we found that the combined use of ciprofloxacin, metronidazole and fluconazole as antifungal prophylaxis increased intestinal yeast colonization when compared to ciprofloxacin and fluconazole alone (P < 0.01). Based on the EORTC criteria, a total of 18 out of 134 study patients developed IFI: seven of 68 (10%) patients who received metronidazole compared to 11 of the 66 (17%) patients decontaminated without metronidazole developed IFI (log-rank P = 0.36). Lethal IFI occurred in two of seven patients receiving metronidazole and in four of 11 patients without anaerobic decontamination. In conclusion, bacterial intestinal decontamination using metronidazole as an antibiotic with activity against most anaerobic intestinal bacteria significantly increases the intestinal yeast burden without influencing the incidence of IFI in patients undergoing allogeneic BMT.
Publication Types:

Clinical trial

Randomized controlled trial

PMID: 11100279

Med Mycol 2000 Jun;38(3):213-9
Treatment of orogastrointestinal candidosis in SCID mice with fluconazole alone or in combination with recombinant granulocyte colony-stimulating factor or interferon-gamma.
Clemons KV, Stevens DA. California Institute for Medical Research, and Department of Medicine, Santa Clara Valley Medical Center, San Jose, CA 95128, USA. Karl.Clemons@slip.net
Mucosal candidosis is common in acquired immune deficiency syndrome (AIDS) patients, where there is extensive mucosal involvement, but rarely dissemination. To mimic this disease, SCID mice were inoculated orally with Candida albicans, which could be recovered from standardized tissue samples of the esophagus, stomach, small intestine and caecum of all mice. Treatment with fluconazole at 5 or 10 mg kg(-1) per day were equivalent to each other and efficacious in reducing the fungal burden from all four tissues compared with no treatment or lower doses of fluconazole (P < 0.01-0.001). Fluconazole at 5 or 10 mg kg(-1) reduced fungal burden in the stomach by about 200 or 580-fold, respectively, and by approximately 25-fold in the other tissues, with 80 or 100% of mice cleared of esophageal infection, and 40 or 80% cleared of infection in the small intestine, respectively; the same doses cleared < or =20% of stomach infection and none of caecal infection. Treatment with recombinant human granulocyte colony-stimulating factor (G-CSF) up to 500 microg kg(-1) per day or 10(5) U of murine interferon-gamma (IFN-gamma) alone was ineffective, nor were combinations with a suboptimal dose fluconazole synergistic. Overall, fluconazole had dose-responsive efficacy, whereas neither G-CSF nor IFN-gamma alone or in combination with fluconazole improved efficacy. These studies demonstrate the utility of this model for examining antifungal efficacy in a situation that mimics clinical disease in AIDS patients.
PMID: 10892989

J Clin Microbiol 2000 Jun;38(6):2369-73
Correlation between in vitro and in vivo antifungal activities in experimental fluconazole-resistant oropharyngeal and esophageal candidiasis.
Walsh TJ, Gonzalez CE, Piscitelli S, Bacher JD, Peter J, Torres R, Shetti D, Katsov V, Kligys K, Lyman CA. Immunocompromised Host Section, Pediatric Oncology Branch, National Cancer Institute, Bethesda, Maryland 20892, USA. walsht@mail.nih.gov
Oropharyngeal and esophageal candidiasis (OPEC) is a frequent opportunistic mycosis in immunocompromised patients. Azole-resistant OPEC is a refractory form of this infection occurring particularly in human immunodeficiency virus (HIV)-infected patients. The procedures developed by the Antifungal Subcommittee of the National Committee for Clinical Laboratory Standards (NCCLS) are an important advance in standardization of in vitro antifungal susceptibility methodology. In order to further understand the relationship between NCCLS methodology and antifungal therapeutic response, we studied the potential correlation between in vitro susceptibility to fluconazole and in vivo response in a rabbit model of fluconazole-resistant OPEC. MICs of fluconazole were determined by NCCLS methods. Three fluconazole-susceptible (FS) (MIC, </=0.125 microgram/ml) and three fluconazole-resistant (FR) (MIC, >/=64 microgram/ml) isolates of Candida albicans from prospectively monitored HIV-infected children with OPEC were studied. FR isolates were recovered from children with severe OPEC refractory to fluconazole, and FS isolates were recovered from those with mucosal candidiasis responsive to fluconazole. Fluconazole at 2 mg/kg of body weight/day was administered to infected animals for 7 days. The concentrations of fluconazole in plasma were maintained above the MICs for FS isolates throughout the dosing interval. Fluconazole concentrations in the esophagus were greater than or equal to those in plasma. Rabbits infected with FS isolates and treated with fluconazole had significant reductions in oral mucosal quantitative cultures (P < 0.001) and tissue burden of C. albicans in tongue, soft palate, and esophagus (P < 0.001). In comparison, rabbits infected with FR isolates were unresponsive to fluconazole and had no reduction in oral mucosal quantitative cultures or tissue burden of C. albicans versus untreated controls. We conclude that there is a strong correlation between in vitro fluconazole susceptibility by NCCLS methods and in vivo response to fluconazole therapy of OPEC due to C. albicans.
PMID: 10835005

J Antimicrob Chemother 1994 Feb;33(2):309-18
The effect of fluconazole prophylaxis on fungal colonization in neutropenic cancer patients. Bone Marrow Transplantation Team.
Chandrasekar PH, Gatny CM. Infectious Diseases/Hematology-Oncology Liaison Unit, Wayne State University School of Medicine, Detroit, MI 48201.
The impact of prophylaxis with 400 mg/day fluconazole on fungal colonization at different body sites was assessed in a randomized, double-blind, placebo controlled study among patients with leukaemia and those undergoing bone marrow transplantation. The study drug was given throughout the period of neutropenia and samples were obtained at weekly intervals. Of the 23 patients in each group, 11 of those given fluconazole and 12 placebo recipients were colonized at entry. The commonest sites were the oropharynx and rectum and Candida albicans was the most frequent isolate. Fluconazole led to a marked reduction in colonization by the second week of treatment to 29% compared with 68% for those given the placebo. Two-weeks after stopping the study regimen there was little change with yeast being isolated from 33% and 81% respectively. Fluconazole was particularly effective in reducing the carriage of C. albicans in the oropharynx from 46% to 0-10% and in maintaining this throughout prophylaxis. Recovery of Candida (Torulopsis) glabrata from the perianal region steadily increased to around 30% in both patient groups and while Candida krusei species were found exclusively in patients given fluconazole, other candida were more common in the placebo group. These results demonstrate that by rapidly reducing the colonization of the alimentary tract, fluconazole eliminates the major reservoir for infection with yeasts other than C. glabrata and C. krusei during the critical period of neutropenia.
Publication Types:

Clinical trial

Randomized controlled trial

PMID: 8182012

Wien Klin Wochenschr 1999 Jul 30;111(14):539-48
[Intestinal ischemic reperfusion syndrome: pathophysiology, clinical significance, therapy].
Schwarz B, Salak N, Hofstotter H, Pajik W, Knotzer H, Mayr A, Hasibeder W. Universitatsklinik fur Anasthesie und Allgemeine Intensivmedizin, Leopold-Franzens-Universitat Innsbruck, Osterreich.
Gut ischemia-reperfusion injury is a serious condition in intensive care patients. Activation of immune cells within the huge endothelial surface area of gut microcirculation may initiate a systemic inflammatory response with secondary injury to distant organs. Translocation of bacteria and toxins through a leaky gut mucosa may amplify or perpetuate systemic inflammation, leading to multiple organ dysfunction syndrome and death in critically ill patients. Gut ischemia promotes regional production of inflammatory mediators, expression of cell adhesion molecules on endothelial and immune cell surfaces and increases the procoagulatory properties of vascular endothelial cells. During reperfusion, gut injury may be amplified by increased production of oxygen radicals and exhaustion of endogenous antioxidant defence mechanisms. Although several therapeutic strategies to interrupt the pathophysiology of ischemia-reperfusion have been shown to be beneficial in animal experiments, none of these interventions has gained clinical relevance. After initial hemodynamic and respiratory stabilisation of critically ill patients, strategies to prevent secondary gut injury by increasing splanchnic oxygen delivery or augment mucosal cell regeneration may be the only therapeutic options for intensive medical specialists at the present time. Early enteral nutrition and treatment with specific vasoactive drugs may reduce morbidity and costs of treatment in certain critically ill patients. However definitive evidence of a reduction in mortality with these therapies has still not be provided.
Publication Types:

Review

Review, tutorial

PMID: 10467640

Pancreas 2001 Aug;23(2):148-56
Beneficial effects of growth hormone on bacterial translocation during the course of acute necrotizing pancreatitis in rats.
Wang X, Wang B, Wu J, Wang G. Department of Gastroenterology, Shanghai First People's Hospital, People's Republic of China. xpwcn@public7.Sta.Net.Cn
Because bacterial translocation from the gut is one of the important sources of bacterial infection in acute necrotizing pancreatitis (ANP) and growth hormone (GH) has the ability to promote the intestinal epithelial proliferation, we investigated the effects of GH on bacterial translocation in a rat ANP model. ANP was induced in rats by injection of 5% sodium taurocholate into the biliopancreatic duct. The rats with ANP were treated with either human recombinant GH or placebo. Laparotomized animals without induction of ANP (sham operation [SO]) served as controls. At 24 hours after operation, blood was drawn for bacterial culture and determination of amylase, lipase, and endotoxin. Peritoneal fluid and specimens of mesenteric lymph nodes (MLN), liver, pancreas, and spleen were taken for bacterial culture by standard techniques. Intestinal mucosal permeability was assessed by measuring the movement of 125I-labeled albumin from blood to intestinal lumen. Insulin-like growth factor-1 (IGF-1) mRNA was detected in the liver and ileum by reverse transcriptase-polymerase chain reaction (RT-PCR). Morphologic changes of pancreas and ileum were also analyzed. Administration of GH significantly decreased the serum amylase, lipase activities, plasma endotoxin level, and incidence of bacterial translocation. Moreover, the survival rate of ANP rats was improved. The severity of inflammation in pancreas and ileum was alleviated by GH treatment. Ileal mucosal thickness, villus height, and crypt depth in GH treatment rats were obviously increased compared with those of ANP rats. The intestinal permeability was markedly improved in the GH group versus the ANP group. GH treatment resulted in up-regulation of IGF-1 mRNA expression in ileum, but not in liver. These results suggested that exogenous GH had beneficial effects in maintaining the integrity of intestinal mucosal barrier and reducing the incidence of bacterial translocation in rats with ANP. One of the mechanisms might be the up-regulation of IGF-1 mRNA in intestine by GH treatment.
PMID: 11484917

Dig Dis Sci 2001 Jul;46(7):1558-66
Alterations of epithelial permeability by Helicobacter and IL-1beta in vitro: protective effect of rebamipide.
Matysiak-Budnik T, Thomas-Collignon A, Megraud F, Heyman M. INSERM E 9925, Faculte de Medecine, Necker-Enfants Malades, Paris, France.
Infection with Helicobacter increases the transcellular passage of macromolecules across the epithelium, and this effect can be prevented by a gastroprotective agent rebamipide. The aim was to gain insight into the mechanisms involved. The HT29-19A intestinal epithelial cells grown on microporous filters as monolayers were incubated in the presence or absence of rebamipide (1 or 2 mM) with: (1) suspension of a wild H. pylori strain, (2) IL-1beta (0.5 ng/ml) + IFN-gamma (2 units/ml). After incubation, the monolayers were submitted to evaluation of apoptosis by using the apoptotic cell death detection ELISA kit and to assessment of epithelial permeability in Ussing chamber where the ionic conductance (G), fluxes of mannitol (J(Man)) and of horseradish peroxidase in both intact (J(HRPi))- and degraded (J(D)) form, were measured. H. pylori increased the intact HRP fluxes across the barrier (J(HRPi) = 17 +/- 20 vs 97 +/- 70 ng/hr/cm2, P < 0.007), an effect prevented by rebamipide (J(HRPi) = 33 +/- 34 ng/hr/cm2, P < 0.006). IL-1beta increased the ionic conductance (G = 5.5 +/- 1.0 and 21.0 +/- 7.0 mS/cm2, P < 0.006), the intact HRP fluxes (J(HRPi) = 18 +/- 15 and 476 +/- 344 ng/hr/cm2, P < 0.006), and the apoptotic index of the cells (AI = 1 +/- 0 vs 3.7 +/- 0.8), all effects prevented by rebamipide (G = 12 +/- 4.9 mS/cm2, J(HRPi) = 79 +/- 38, AI = 1.6 +/- 0.6, P < 0.03 as compared to IL-beta-treated cells). In basal conditions, rebamipide increased the integrity of the barrier (G = 7.5 +/- 2.3 vs 6.0 +/- 1.8 mS/cm2 for controls, P < 0.007). In conclusion, H. pylori as well as IL-1beta, may alter epithelial permeability and rebamipide may exert its protective effect on gastric mucosa by reinforcing the epithelial barrier in normal conditions and by counteracting the deleterious effect of Helicobacter pylori and IL-1beta on macromolecular permeability.
PMID: 11478510

Dig Dis Sci 2001 Jul;46(7):1490-9
Phorbol ester treatment increases paracellular permeability across IEC-18 gastrointestinal epithelium in vitro.
Marano CW, Garulacan LA, Ginanni N, Mullin JM. Lankenau Institute for Medical Research, Wynnewood, Pennsylvania 19096, USA.
The phorbol ester, TPA, transiently increases the transepithelial permeability across the gastrointestinal epithelium formed by IEC-18. There was a significant decrease in transepithelial resistance (R(T)) between 0 and 1.5 hr, accompanied by increased flux of polyethylene glycol (4000 MW), suggesting that the increase was across the tight junction. By 2 hr, the decrease in R(T) reversed and maintained control level. The transepithelial permeability increase was prevented by coincubation with the protein kinase C (PKC) inhibitor bisindolylmaleimide. There was a rapid (within 15 min) translocation of PKC-alpha from the cytosolic to the "membrane-associated" compartment, followed by a down-regulation that was detectable within 60 min of TPA treatment. The down-regulation of PKC-alpha from the membrane was prevented by either calpain inhibitor I or MG-132 and resulted in a sustained permeability increase. The permeability changes were not accompanied by significant effects on the amount or localization of the tight junctional proteins, occludin and ZO-1. However, occludin did show a reversible increase in phosphorylation with TPA treatment. Together these data support a role for PKC-alpha-mediated regulation of barrier permeability in an in vitro model of small intestinal epithelium, perhaps through modulation of the phosphorylation state of the tight junctional protein, occludin.
PMID: 11478501

Dtsch Tierarztl Wochenschr 2001 Jun;108(6):246-8
Effects of oligosaccharides on functional parameters of the intestinal tract of growing pigs.
Breves G, Szentkuti L, Schroder B. Department of Physiology, School of Veterinary Medicine, Hannover. gerhard.breves@tiho-hannover.de
Feeding experiments were carried out in growing pigs using topinambur powder or inactivated yeasts as prebiotic additives with an application period of at least 3 weeks. At the end of the experimental periods the animals were killed and segments of the intestinal tract were used for measuring transport physiological parameters and for mucin histochemistry. Jejunal epithelia were mounted in Ussing chambers for measuring electrical tissue parameters, paracellular permeability and short circuit current response to mucosal glucose. Both prebiotics had no effects on basal or forskolin stimulated short circuit currents. Total tissue conductances tended to be higher in response to both prebiotics. Topinambur increased mucosal-to-serosal fluxes of mannitol in the proximal and distal jejunum, which could only be demonstrated for the distal jejunum when inactivated yeasts were fed. Mucosal application of glucose induced higher current responses in jejunal tissues. From histochemistry it could be demonstrated that both prebiotics increased the number of ileal goblet cells and the thickness of the colonic mucosa.
PMID: 11449909

Nippon Shokakibyo Gakkai Zasshi 2001 Jun;98(6):636-43

[Intestinal permeability in Crohn's disease and effects of elemental dietary therapy].
Iwata M, Nakano H, Matsuura Y, Nagasaka M, Misawa M, Mizuta S, Ito I, Saito T, Ito T, Hokama M, Kamiya M, Hobara R, Watanabe M, Takahama K. Department of Internal Medicine and Gastroenterology, Fujita Health University.
Enteral intake of non-metabolic monosacharide and disaccharide, followed by measurement of the urinary excretion ratio of the two, is a method used to investigate intestinal permeability. L/R ratio (lactulose/1-rhamnose urinary excretion ratio) is considered an indicator of permeability of the small intestine. An increased L/R ratio is caused by mucosal disorders of the small intestine. The L/R ratio in all patients (n = 92) with Crohn's disease was 0.079 +/- 0.081 (mean +/- S.D.), which was significantly higher than the value in normal controls (0.027 +/- 0.009, n = 20, p < 0.05). In 39 patients with Crohn's disease, we assessed intestinal permeability before after treatment with an elemental diet, and during remission. The L/R ratio was 0.120 +/- 0.092, before treatment and 0.065 +/- 0.097 after treatment (p < 0.05), showing increased intestinal permeability before elemental dietary treatment. During remission, the L/R ratio was 0.035 +/- 0.028; this did not differ significantly from the value obtained after treatment. We conclude that intestinal permeability is useful for investigating disease activity in patients with Crohn's disease.
PMID: 11436280

Br J Clin Pharmacol 2001 Jun;51(6):557-65
Increased oral ganciclovir bioavailability in HIV-infected patients with chronic diarrhoea and wasting syndrome-a population pharmacokinetic study.
Mouly S, Aymard G, Tillement JP, Caulin C, Bergmann JF, Urien S. Department of Internal Medicine, Lariboisiere Hospital, 75475 Paris Cedex 10, Laboratory of Pharmacology, La SalPetriere Hospital, 75013 Paris and Laboratory of Pharmacology, Faculty of Medicine, Henri Mondor Hospital, 94010 Creteil, France.
AIMS: Despite a lack of data, the antiviral agent ganciclovir is not indicated in AIDS patients with diarrhoea because of its presumed poor oral bioavailability. To assess the effect of diarrhoea on ganciclovir intestinal absorption, we conducted a pharmacokinetic study in 42 HIV-infected patients categorized into three groups: A, HIV stage A and B (n = 15); B, AIDS stage C (n = 13); C, AIDS with chronic diarrhoea and wasting syndrome (n = 14). METHODS: Each patient was evaluated for nutritional (body mass index, albumin, transferrin serum levels), inflammatory (haptoglobin, orosomucoid), immunological (CD4 count, plasma viral load) and intestinal (D-xylose test, faecal fat and nitrogen output, intestinal permeability) status. Ganciclovir (1 g) was administered orally to fasted patients. Six blood samples were collected over 24 h. Serum was analysed for ganciclovir by h.p.l.c. Population pharmacokinetic analysis was performed using a nonlinear mixed effects modelling program, MP2. RESULTS: Mean intestinal permeability (lactulose/mannitol urinary ratio) was increased in group C (0.2) compared with group A (0.05) and B (0.1) patients. Drug concentration-time profiles were best described by a two-compartment model. Apparent oral clearance (CL/F) and central volume of distribution (V1/F) were influenced by clinical status (group). For groups A and B combined, final parameter estimates of CL/F and V1/F were 256 +/- 98 l h-1 and 1320 +/- 470 l, respectively. Final parameter estimates for group C were 118 +/- 108 l h-1 and 652 +/- 573 l for CL/F and V1/F, respectively. The 95% confidence intervals on differences between A and B combined and C were statistically significant ([ + 70, + 206] for CL/F, and [+ 314, + 1022] for V1/F). Compared with groups A and B, ganciclovir CL/F was significantly decreased in group C patients. CONCLUSIONS: AIDS patients with diarrhoea and severe disease may benefit from ganciclovir therapy, but a dose adjustment may be required according to their digestive and immunological status.
PMID: 11422015

J Surg Res 2001 Jul;99(1):114-9
Intestinal and hemodynamic impairment following mesenteric ischemia/reperfusion.
Khanna A, Rossman JE, Fung HL, Caty MG. Department of Pharmaceutics, University at Buffalo, Amherst, New York 14260, USA. ashish.khanna@bms.com
BACKGROUND: Clinical intestinal ischemia/reperfusion (I/R) injury results in local and systemic dysfunction. A rat model of transient mesenteric occlusion has been used to study this phenomenon. However, a systematic analysis of the rat model with respect to intestinal permeability and hemodynamics has not been carried out. MATERIALS AND METHODS: In anesthetized rats, the superior mesenteric artery was occluded for 60 min, followed by reperfusion for 4 h. Intestinal impairment was evaluated via histological examination and by measuring ex vivo apparent permeability coefficients (Papp) of mannitol (0.18 kDa), inulin (5 kDa), and dextran (70 kDa). Hemodynamic effects of intestinal I/R were determined by monitoring mean arterial pressure (MAP) and heart rate (HR) via a catheter placed in the femoral artery. RESULTS: The animal model was associated with increased ex vivo Papp for mannitol and inulin. Although I/R injury was accompanied by significant histological disruption, there was no observable alteration in dextran permeability, suggesting that the loss in normal barrier function was limited to low-molecular-weight compounds. Hemodynamic measurements indicated that reperfusion induced a precipitous and sustained fall in MAP. HR values fell sharply following reperfusion but gradually increased and eventually "overshot" to values greater than baseline. CONCLUSIONS: Our findings demonstrate the selective loss of barrier function of the small bowel following intestinal I/R. Furthermore, these results also illustrate the importance of selecting appropriate permeability markers for the evaluation of intestinal damage. In light of the significant hemodynamic disruption accompanying the animal model, our investigation also points toward the need for developing therapeutic strategies that mitigate the local and systemic effects of intestinal I/R injury. Copyright 2001 Academic Press.
PMID: 11421612

Pediatr Surg Int 2001 May;17(4):269-74
The effect of phospholipids and fatty acids on tight-junction permeability and bacterial translocation.
Sawai T, Drongowski RA, Lampman RW, Coran AG, Harmon CM. Section of Pediatric Surgery, University of Michigan, Mott Children's Hospital, Ann Arbor, MI 48109-0245, USA
The activity of phospholipase A2 (PLA2) is elevated in the intestinal epithelia of patients with inflammatory bowel disease (IBD). We recently reported that PLA2 mediates hydrolysis of phosphatidylcholine (PC) to lysophosphatidylcholine (L-PC) when both are applied to the apical surface of cultured EC monolayers, resulting in increased bacterial translocation (BT) and decreased transepithelial electrical resistance (TEER). Free fatty acids (FFA) are the other products of this reaction, however, their effect on Caco-2 cell permeability has not been reported. In addition to PC, other luminal phospholipids are present at the surface of the enterocyte. PLA2 may also mediate the hydrolysis of luminal phospholipids other than PC. The aim of this study was to examine the effects of phospholipids other than PC and common FFA on intestinal epithelial permeability and BT. Human Caco-2 enterocytes were grown to confluence on porous filters in the apical chamber of a two-chamber cell-culture system. Monolayer integrity and tight-junction permeability were measured as TEER. First, common FFA released by PC hydrolysis were determined using thin-layer chromatography (TLC). In separate experiments, monolayers were treated with phosphatidylethanolamine (PE), lysophosphatidylethanolamine (L-PE), or palmitoleic acid, oleic acids, linoleic acids, and arachidonic acid solubilized in solution with PC. The magnitude of BT was determined 2 h after treatment by adding Escherichia coli C25 to the apical chamber followed by quantitatively culturing basal-chamber samples. Statistical analysis was by the Kurosaki-Wallis test. TLC of PC samples incubated with PLA2 on the apical surface of Caco-2 monolayers demonstrated the production of palmitoleic acid, oleic acids, linoleic acids, and arachidonic acid. L-PE significantly decreased TEER compared to controls, but to a lesser degree than L-PC alone. L-PE had no effects on BT. Palmitoleic acid and oleic acid likewise significantly decreased TEER compared to controls, however, less than L-PC. All FFA tested had no effect on BT. Phospholipids applied to the apical surface of enterocytes, such as those found in vivo in mucus, can be hydrolyzed by the enzyme PLA2 resulting in lysophospholipid and FFA species that can alter enterocyte monolayer permeability. However, FFA and L-PL, other than L-PC, appear to have no effect to stimulate BT. This observation may have clinical implications in the pathogenesis and treatment strategies for IBD patients in whom enterocyte PLA2 activity has been shown to be elevated.
PMID: 11409160

Physiol Behav 2001 May;73(1-2):43-9
Subchronic mild noise stress increases HRP permeability in rat small intestine in vitro.
Bijlsma PB, van Raaij MT, Dobbe CJ, Timmerman A, Kiliaan AJ, Taminiau JA, Groot JA. Department of Pediatric Gastroenterology and Nutrition, Academic Medical Centre/Institute of Neurobiology, University of Amsterdam, Kruislaan 320, 1098 SM Amsterdam, Netherlands. bijlsma@bio.uva.nl
Recently we reported an increased trans- and paracellular protein permeability in rat small intestine after acute cold restraint stress. In the present study, we applied randomized 95- or 105-dB white noise pulses during 45 min/h, 12 h/day, duration 8 days, as a milder, but more chronic stressor to male rats. At 8 days before the noise experiments, 50% of the animals were cannulated in the vena cava for blood sampling during the experimental period. The other 50% of the animals were sacrificed at Day 9, segments of ileum were mounted in Ussing chambers and perfused at 37 degrees C. Horseradish peroxidase (HRP) was added mucosally, serosal appearance was detected enzymatically and tissues were fixed for electron microscopy. In the animals exposed to 95-dB noise, plasma corticosterone levels were enhanced twofold compared to controls, and ileal HRP flux was enhanced twofold. Electron micrographs of tissue from stressed or control animals showed no detectable paracellular staining of HRP. Quantification of HRP-containing endosomes in enterocytes revealed a twofold increase in endosome number in the animals exposed to 95-db noise indicating that the increased HRP permeability was primarily due to increased endocytosis. In contrast to the animals exposed to 95-dB noise, rats exposed to 105-dB noise showed no increase in corticosterone levels and ileal HRP fluxes were not significantly different from controls. We conclude that mild subchronic noise stress may cause a decrease in intestinal barrier function by increased transcytosis of luminal antigens.
PMID: 11399293

J Pediatr Gastroenterol Nutr 2001 Apr;32(4):464-70
The effect of antenatal vitamin A and beta-carotene supplementation on gut integrity of infants of HIV-infected South African women.
Filteau SM, Rollins NC, Coutsoudis A, Sullivan KR, Willumsen JF, Tomkins AM. Centre for International Child Health, Institute of Child Health, London, United Kingdom. sfilteau@ich.ucl.ac.uk
BACKGROUND: Vitamin A is important for protection against diarrhea, and supplements may benefit gut function of infants of HIV-infected mothers. METHODS: We studied 238 infants of HIV-infected South African women participating in a randomized, double-blind, placebo-controlled trial of vitamin A during pregnancy (1.5 mg retinyl palmitate and 30 mg beta-carotene daily) plus 60 mg retinyl palmitate at delivery. The placebo group received identical placebo capsules at the same times. When infants were 1, 6, and 14 weeks of age, lactulose/mannitol dual sugar intestinal permeability tests were performed. RESULTS: Maternal vitamin A supplementation did not significantly affect infant gut permeability in the group as a whole at any time. By multiple regression analysis, HIV infection of the infant by 14 weeks was significantly associated with increased gut permeability at both 6 and 14 weeks. After controlling for birth weight, gestational age, current weight, feeding mode and recent morbidity, there was a trend toward an interaction between vitamin A supplementation and HIV infection (P = 0.086) at 14 weeks. Vitamin A made no difference to gut permeability of uninfected infants (lactulose/mannitol ratio for vitamin A group: 0.11, 95% confidence interval [CI] 0.08, 0.15, n = 73 and for placebo group: 0.09, 95% CI 0.06, 0.12, n = 76), but largely prevented the increase in the ratio of HIV-infected infants (vitamin A group: 0.17, 95% CI 0.13, 0.23, n = 23; placebo group: 0.50, 95% CI 0.37, 0.68, n = 20). The effects on the lactulose/mannitol ratio were related to changes in lactulose, not mannitol, excretion. Vitamin A supplementation was associated with significantly lower lactulose excretion at 1 and 14 weeks, suggesting the major effect of vitamin A was on maintaining the integrity of gut tight junctions. CONCLUSIONS: Vitamin A supplementation of HIV-infected pregnant women may prevent the deterioration in gut integrity in the subgroup of their infants who themselves become infected. Improving vitamin A status of HIV-infected infants may decrease their gastrointestinal morbidity.
PMID: 11396815

Inflamm Bowel Dis 2001 May;7(2):94-8
Zinc supplementation tightens "leaky gut" in Crohn's disease.
Sturniolo GC, Di Leo V, Ferronato A, D'Odorico A, D'Inca R. Dipartimento di Scienze Chirurgiche e Gastroenterologiche, Universita di Padova, Italy. gsturn@ux1.unipd.it
OBJECTIVES: Small intestinal permeability is often increased in patients with Crohn's disease and may be pathogenic for clinical relapses. No effective prophylactic treatment is available for these patients. The aim of this study was to ascertain whether zinc supplementation may improve intestinal permeability. METHODS: We studied 12 patients with quiescent Crohn's disease who had been in remission for at least 3 months and had increased intestinal permeability on two separate occasions within the last 2 months. Patients received oral zinc sulfate supplements (110 mg three times a day) for 8 weeks and were followed-up for 12 months thereafter to monitor relapses. RESULTS: We found that the lactulose/mannitol ratio was significantly higher before supplementation than after (0.041 +/- 0.003 versus 0.026 +/- 0.005). During follow-up, 10 patients had normal intestinal permeability and did not relapse; of the remaining two who had increased intestinal permeability, one relapsed. CONCLUSIONS: Our findings show that zinc supplementation can resolve permeability alterations in patients with Crohn's disease in remission. Improving intestinal barrier function may contribute to reduce the risk of relapse in Crohn's disease.
PMID: 11383597

J Appl Physiol 2001 Jun;90(6):2075-80
Gastrointestinal permeability during exercise: effects of aspirin and energy-containing beverages.
Lambert GP, Broussard LJ, Mason BL, Mauermann WJ, Gisolfi CV. Department of Exercise Science, University of Iowa, Iowa City, Iowa 52242, USA.
The purpose of this study was to determine whether aspirin (A) ingestion combined with prolonged exercise increases gastrointestinal permeability and whether consumption of a carbohydrate-containing (CHO) or a CHO + glutamine-containing (CHO+G) beverage would reduce this effect. Seventeen subjects completed six experiments. They ingested A (1,300 mg) or placebo (P) pills the evening before and before running 60 min at 70% maximal oxygen uptake. Also, before running they ingested a solution containing 5 g lactulose (L), 5 g sucrose (S), and 2 g rhamnose (R). During each trial, either a 6% CHO beverage, a 6% CHO+G (0.6%; 41 mM) beverage, or a water placebo (WP) was consumed. For 4 h after a run, all urine was collected to measure urinary excretion of L, R, and S. S excretion (percentage of dose ingested; measure of gastroduodenal permeability) was significantly greater (P < 0.05) during the A trial while the subjects drank the WP compared with all other trials. Administration of A also significantly increased L/R (measure of intestinal permeability) for the CHO and WP trials compared with all P trials. Ingestion the CHO or CHO+G beverages significantly reduced S excretion and L excretion when A was administered, but it did not reduce L/R. These results indicate that gastroduodenal and intestinal permeability increase after A ingestion during prolonged running and that ingestion of a CHO beverage attenuates the gastroduodenal effect but not the intestinal effect. Furthermore, addition of G to the CHO beverage provided no additional benefit in reducing gastroduodenal or intestinal permeability.
Publication Types:

Clinical trial

PMID: 11356768

Am J Physiol Heart Circ Physiol 2001 Jun;280(6):H2857-62
TNF-alpha increases sensitivity to LPS in chronically catheterized rats.
Goto M, Deriy LV, Chen YJ, Beno DW, Uhing MR, Jiyamapa-Serna VA, Kimura RE. Section of Neonatology, Department of Pediatrics, Rush Children's Hospital, Rush Presbyterian St. Luke's Medical Center, Chicago, Illinois 60612, USA.
Patients with severe trauma injury are transiently exposed to increased serum concentrations of tumor necrosis factor-alpha (TNF-alpha). These patients are susceptible to the development of multisystem organ failure (MSOF) triggered by subsequent exposure to bacterial toxins either via infection or increased intestinal permeability. We simulated the cytokine response of trauma by infusing 0.8 or 8.0 microg/kg of TNF-alpha (priming dose) into chronically catheterized rats. After 48 h, rats were challenged with endotoxin [lipopolysaccharide (LPS); 10 or 1,000 microg/kg]. Animals primed with either dose of TNF-alpha and then challenged with 1,000 microg/kg of LPS demonstrated significantly increased mortality, mean peak serum concentrations of interferon-gamma (IFN-gamma), and blood lactate concentrations (P < 0.05) compared with nonprimed animals. Mean peak serum concentrations of IFN-gamma and blood lactate concentrations were increased after challenge with 10 microg/kg of LPS only in animals primed with 8.0 microg/kg of TNF-alpha. Priming with TNF-alpha did not increase mortality after challenge with 10 microg/kg of LPS. These data suggest that both TNF-alpha release and the subsequent exposure to bacterial toxins mediate the pathophysiological progression from trauma to subsequent MSOF.
PMID: 11356645

Scand J Gastroenterol 2001 May;36(5):521-7
Is an increased intestinal permeability a valid predictor of relapse in Crohn disease?
Jorgensen J, Ranlov PJ, Bjerrum PJ, Diemer H, Bisgaard K, Elsborg L. Dept. of Medicine B, Section of Gastroenterology, Hillerod Hospital, Denmark.
BACKGROUND: An increased intestinal permeability (IP) may be a pathogenetic factor in Crohn disease (CD). Increases in IP could be an indicator of subclinical disease and precede clinical relapses. We examined whether an increased IP is a valid predictor of relapse in CD. METHODS: 27 patients with CD in remission (CDAI <150) and 22 healthy controls ingested 3.7 MBq of 51Cr-EDTA, 20 kBq of 14C-mannitol and 5 g of unlabelled mannitol in 100 ml of distilled water. The percent urine excretion (24 h) of labelled markers was determined. Patients were followed for 1 year or until relapse, defined as CDAI > 150 and > 50 from baseline. RESULTS: Median (25th-75th percentiles). The excretion of 51Cr-EDTA was 1.55% (1.13%-2.53%) for patients and 1.20% (1.11%-1.44%) for controls (P = 0.04). Three of 9 patients with a raised, and 6 of 18 patients with a normal, 51Cr-EDTA excretion relapsed (P = 1.00; Fisher's exact test). Thus, the specificity and sensitivity of the 51Cr-EDTA test as a predictor of relapse was 67% and 33%, respectively. The 51Cr-EDTA/14C-mannitol index was 0.060 (0.037-0.093) for patients and 0.045 (0.038-0.054) for controls (P = 0.06). Four of 12 patients with a raised, and 5 of 15 patients with a normal, index relapsed (P = 1.00; Fisher's exact test). Thus, the specificity and sensitivity of the index test as a predictor of relapse was 56% and 44%, respectively. For controls and patients in remission, who were tested twice, variability of and fluctuations in both the 51Cr-EDTA excretion and the index were greatest for patients. CONCLUSIONS: This study supports previous findings of an increased IP in patients with CD. Although fluctuations in the permeation of markers were pronounced in CD, neither the excretion of 51Cr-EDTA nor the 51Cr-EDTA/14C-mannitol index test were valid predictors of relapse in CD.
PMID: 11346207

J Immunol 2001 Aug 15;167(4):2234-9
The role of IL-4 in Heligmosomoides polygyrus-induced alterations in murine intestinal epithelial cell function.
Shea-Donohue T, Sullivan C, Finkelman FD, Madden KB, Morris SC, Goldhill J, Pineiro-Carrero V, Urban JF Jr. Department of Medicine, Uniformed Services University of the Health Sciences, Bethesda, MD 20814, USA. tshea@usuhs.mil
IL-4 and IL-13 promote gastrointestinal worm expulsion, at least in part, through effects on nonlymphoid cells, such as intestinal epithelial cells. The role of IL-4/IL-13 in the regulation of intestinal epithelial function during Heligmosomoides polygyrus (Hp) infection was investigated in BALB/c mice infected with Hp or treated with a long-lasting formulation of recombinant mouse IL-4/alphaIL-4 complexes (IL-4C) for 7 days. Separate groups of BALB/c mice were drug-cured of initial infection and later reinfected and treated with anti-IL-4R mAb, an antagonist of IL-4 and IL-13 receptor binding, or with a control mAb. Segments of jejunum were mounted in Ussing chambers, and short circuit current responses to acetylcholine, histamine, serotonin, PGE2, and glucose were determined. Although only modest changes in epithelial cell function were observed during primary Hp infection, IL-4C or a secondary Hp infection each induced more dramatic changes, including increased mucosal permeability, reduced sodium-linked glucose absorption, and increased Cl- secretory response to PGE2. Some, but not all, effects of IL-4C and Hp infection were dependent on enteric nerves. Hp-induced changes in epithelial function were attenuated or prevented by anti-IL-4R mAb. Thus, IL-4/IL-13 mediate many of the effects of Hp infection on intestinal epithelial cell function and do so both through direct effects on epithelial cells and through indirect, enteric nerve-mediated prosecretory effects. These immune system-independent effector functions of IL-4/IL-13 may be important for host protection against gastrointestinal nematodes.
PMID: 11490010

Biol Neonate 2001 Jul;80(1):60-3
Effect of n(g)-nitro-l-arginine methyl ester on intestinal permeability following intestinal ischemia-reperfusion injury in a rat model.
Luo CC, Chen HM, Chiu CH, Lin JN, Chen JC. Department of Pediatric Surgery and Pediatrics, Chang Gung Children's Hospital and College of Medicine, Chang Gung University, Taoyuan, Taiwan.
Subclinical intestinal ischemia-reperfusion injury (IRI) causes an increase in mucosal permeability and may represent an early event in the pathogenesis of necrotizing enterocolitis in premature infants. Previous studies suggested that continuous, endogenous formation of nitric oxide (NO) maintains the mucosal integrity of the intestine, thus protecting the gut from injuries from blood-borne toxins and tissue-destructive mediators. This study was undertaken to assess whether the inhibition of NO production causes an increase in intestinal permeability in rats following IRI. Sprague-Dawley rats weighing 200-300 g were divided into 4 groups: (1) untreated group (normal control); (2) ischemia-reperfusion group; (3) early N(G)-nitro-L-arginine methyl ester (L-NAME), a specific inhibitor of NO production, treatment group, and (4) late L-NAME treatment group. Transient IRI was induced by 30-min occlusion, followed by reperfusion of the isolated ileal loop. The L-NAME was administered 15 min before and after mesenteric ischemia as a 25-mg/kg bolus. Fluorescein isothiocyanate-dextran (FITC-D) was used to quantitatively assess the alteration in mucosal permeability of the intestine. There was no significant increase in the portal vein FITC-D level among normal controls, ischemia-reperfusion group and late L-NAME-treated group, but there was an approximately 6-fold increase in the early L-NAME treatment group. The pathological features of the intestine following IRI include denudation of the villus epithelium and reduction of villus height, associated with marked inflammatory cell infiltration over the lamina propria. These results suggest that endogenous NO may play a role in the protecting intestinal integrity after IRI. Copyright 2001 S. Karger AG, Basel
PMID: 11474151

Rev Prat 2001 May 15;51(9):945-52
Brazier F, Delcenserie R, Dupas JL. Service d'hepato-gastro-enterologie Hopital Nord 80054 Amiens.
Hydrolysis of dietary constituents is necessary to allow nutrients absorption by the small intestinal enterocytes. The digestion process takes place in the intestinal lumen, in the brush border membrane, in the enterocyte, and is mediated by a large number of hydrolases secreted in the gastrointestinal tract or produced by the epithelial cells and localized in the brush border. Nutrients are essentially absorbed via a transcellular route across enterocyte cell membranes to enter bloodstream or lymphatic circulation. Transport of nutrients across apical or basolateral membranes occur by active or facilitated mechanisms involving specific transporters. Water, electrolytes and small molecules can be partly absorbed via paracellular pathway. Tight junction permeability is regulated by osmolarity of intercellular space, definite nutrient concentrations in lumen, and activity of brush border membrane transporters.
PMID: 11458607

Novartis Found Symp 2001;238:82-96; discussion 96-100
Pathogenesis of rotavirus gastroenteritis.
Estes MK, Kang G, Zeng CQ, Crawford SE, Ciarlet M. Division of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, TX 77030, USA.
The outcome of intestinal infection with rotaviruses is more complex than initially appreciated, and it is affected by a complex interplay of host and viral factors. Rotaviruses infect intestinal enterocytes, and the early events in infection are mediated by virus-epithelial cell interactions. Diarrhoea may be caused by several mechanisms including (i) malabsorption that occurs secondary to the destruction of enterocytes, (ii) villus ischaemia and activation of the enteric nervous system that may be evoked by release of a vasoactive agent from infected epithelial cells in the absence of significant pathologic lesions or enterocyte damage, and (iii) intestinal secretion stimulated by the intracellular or extracellular action of the rotavirus non-structural protein, NSP4, a novel enterotoxin and secretory agonist with pleiotropic properties. New studies of rotavirus infection of polarized intestinal epithelial cells show that rotaviruses infect cells differently depending on whether or not they require sialic acid for initial binding, and infection alters epithelial cell functions. NSP4 also affects epithelial cell function and interactions. NSP4 (i) induces an age- and dose-dependent diarrhoeal response in young rodents that is similar to virus-induced disease, (ii) stimulates a Ca(2+)-dependent cell permeability where the secretory response is age-dependent, and (iii) alters epithelial cell integrity. Antibody to NSP4 protects mouse pups from diarrhoea induced by homotypic and heterotypic viruses. These data support a new mechanism of rotavirus-induced diarrhoea whereby a viral enterotoxin triggers a signal transduction pathway that alters epithelial cell permeability and chloride secretion. This new information about how a gastrointestinal virus causes disease demonstrates common pathogenic mechanisms for viral and bacterial pathogens not previously appreciated. These results also suggest new approaches to prevent or treat rotavirus-induced diarrhoea.
PMID: 11444037

Nippon Shokakibyo Gakkai Zasshi 2001 Jun;98(6):636-43
[Intestinal permeability in Crohn's disease and effects of elemental dietary therapy].
Iwata M, Nakano H, Matsuura Y, Nagasaka M, Misawa M, Mizuta S, Ito I, Saito T, Ito T, Hokama M, Kamiya M, Hobara R, Watanabe M, Takahama K. Department of Internal Medicine and Gastroenterology, Fujita Health University.
Enteral intake of non-metabolic monosacharide and disaccharide, followed by measurement of the urinary excretion ratio of the two, is a method used to investigate intestinal permeability. L/R ratio (lactulose/1-rhamnose urinary excretion ratio) is considered an indicator of permeability of the small intestine. An increased L/R ratio is caused by mucosal disorders of the small intestine. The L/R ratio in all patients (n = 92) with Crohn's disease was 0.079 +/- 0.081 (mean +/- S.D.), which was significantly higher than the value in normal controls (0.027 +/- 0.009, n = 20, p < 0.05). In 39 patients with Crohn's disease, we assessed intestinal permeability before after treatment with an elemental diet, and during remission. The L/R ratio was 0.120 +/- 0.092, before treatment and 0.065 +/- 0.097 after treatment (p < 0.05), showing increased intestinal permeability before elemental dietary treatment. During remission, the L/R ratio was 0.035 +/- 0.028; this did not differ significantly from the value obtained after treatment. We conclude that intestinal permeability is useful for investigating disease activity in patients with Crohn's disease.
PMID: 11436280

Surgery 2001 Jul;130(1):65-73
Surgical stress shifts the intestinal Escherichia coli population to that of a more adherent phenotype: role in barrier regulation.
Rocha F, Laughlin R, Musch MW, Hendrickson BA, Chang EB, Alverdy J. Department of Surgery, The University of Chicago Medical Center and the Pritzker School of Medicine, Chicago, IL, USA.
BACKGROUND: We have shown that the combination of surgical stress and starvation in mice is associated with a defect in epithelial permeability and increased numbers of mucosa-associated Escherichia coli in the cecum. The aim of this study was to determine the specific role of mucosa-associated E coli on epithelial barrier dysfunction in this model. METHODS: Cecal E coli were harvested from mice 48 hours after a sham operation (control mice) or after a 30% surgical hepatectomy with only water provided ad libitum (short-term starvation) after the surgical procedure. Strains were tested for their ability to adhere to and alter the transepithelial electrical resistance (TEER) of cultured young adult mouse colon epithelial cells. TEER changes were further characterized by mannitol fluxes to confirm a defect in paracellular permeability. RESULTS: Strains of cecal E coli harvested from hepatectomy-starved mice adhered to and altered the permeability of young adult mouse colon cells, whereas E coli from the cecum of control mice were less adherent and had no effect on epithelial permeability. The effect of the strains harvested from mice after hepatectomy on the TEER of young adult mouse colon cells was inhibited by mannose and reversed by ciprofloxacin. CONCLUSION: The combination of surgical stress and short-term starvation is associated with a greater abundance of adherent and barrier-altering strains of E coli in the mouse cecum.
PMID: 11436014

Acta Paediatr 2001 May;90(5):499-504
Intestinal permeability in children: variation with age and reliability in the diagnosis of cow's milk allergy.
Kalach N, Rocchiccioli F, de Boissieu D, Benhamou PH, Dupont C. Department of Pediatrics, Hjpital Cochin St Vincent de Paul, Paris, France. christophe.dupont@svp.ap-hop-paris.fr
OBJECTIVE: To analyse to what extent age may alter intestinal permeability (IP) in children and to assess its reliability according to clinical manifestations in cow's milk allergy (CMA). DESIGN: A routine prospective study was performed in 200 children (12.5+/-23 mo, 0.5-168 mo) presenting with clinical manifestations suggesting CMA. Controls (n = 105) were those with a negative cow's milk challenge, whereas CMA children (n = 95) fulfilled ESPGHAN criteria. Permeability was measured as a percentage of urinary excretion of lactitol (L, %) and mannitol (M, %) (0.1 g/kg for each, oral absorption after a 6 h fast, 5 h urine collection, analysis by gas chromatography) and determination of the L/M ratio (L/M, %). RESULTS: In control children, L/M correlated negatively with age (r -0.33, p = 0.0006), whereas in those with CMA no correlation was found. Median L/M was significantly higher in CMA children (n = 95) than in controls (n = 105), 4.35+/-7.57% (95% CI 5.30-8.39%) vs 1.97+/-0.87% (95% CI 1.76-2.09%), (p = 0.0001). With a L/M cut-off value defined as mean + 2 SD of controls, in CMA IP exhibited a 68% sensitivity and a 77% negative predictive value. The highest sensitivity (70%) was seen at ages 6-12 mo and the lowest (58%) at age more than 3 y. An abnormal IP was seen in 80% of CMA children with digestive manifestations, in 43% with extra-digestive, 68% with mixed and 40% with anaphylactic manifestations. CONCLUSION: IP correlates negatively with age in control children and is altered in children with CMA. The test is at its most accurate in the diagnosis of CMA when done at ages 6-12 mo, when there are digestive manifestations.
PMID: 11430707

J Surg Res 2001 Jul;99(1):120-8
Intestinal mitochondrial dysfunction in surgical stress.

Ramachandran A, Patra S, Balasubramanian KA. Department of Gastrointestinal Sciences, The Wellcome Trust Research Laboratory, Christian Medical College & Hospital, Vellore, 632004, India.
BACKGROUND: Surgical stress is associated with altered intestinal function. Our earlier study using a rat model indicated that oxidative stress plays an important role in this process. Since mitochondria are crucial to cellular function and survival and are both a target as well as a source of reactive oxygen species, the present study looks at the changes in enterocyte mitochondria during surgical stress. METHODS: Surgical stress was induced by opening the abdominal wall and handling the intestine as done during laparotomy. Mitochondria were prepared from the isolated enterocytes at different time periods after surgical stress. The effect of surgical stress on enterocyte mitochondrial ultrastructure, respiration, anti-oxidant enzyme activity, thiol redox status, calcium flux, permeability, and matrix enzymes was then studied. RESULTS: Surgical stress resulted in alterations in mitochondrial respiration and thiol redox status. It was also associated with altered mitochondrial matrix enzyme activity, decreased superoxide dismutase activity, induction of mitochondrial permeability transition, and swelling, as well as impairment of mitochondrial calcium flux. These alterations were seen at a maximum of 60 min following surgical stress and were reversed by 24 h. CONCLUSIONS: Laparotomy and mild intestinal handling itself results in enterocyte mitochondrial damage. Since mitochondria are important cellular organelles, this damage can probably lead to compromised intestinal function. Copyright 2001 Academic Press.
PMID: 11421613

J Surg Res 2001 Jul;99(1):114-9
Intestinal and hemodynamic impairment following mesenteric ischemia/reperfusion.
Khanna A, Rossman JE, Fung HL, Caty MG. Department of Pharmaceutics, University at Buffalo, Amherst, New York 14260, USA. ashish.khanna@bms.com
BACKGROUND: Clinical intestinal ischemia/reperfusion (I/R) injury results in local and systemic dysfunction. A rat model of transient mesenteric occlusion has been used to study this phenomenon. However, a systematic analysis of the rat model with respect to intestinal permeability and hemodynamics has not been carried out. MATERIALS AND METHODS: In anesthetized rats, the superior mesenteric artery was occluded for 60 min, followed by reperfusion for 4 h. Intestinal impairment was evaluated via histological examination and by measuring ex vivo apparent permeability coefficients (Papp) of mannitol (0.18 kDa), inulin (5 kDa), and dextran (70 kDa). Hemodynamic effects of intestinal I/R were determined by monitoring mean arterial pressure (MAP) and heart rate (HR) via a catheter placed in the femoral artery. RESULTS: The animal model was associated with increased ex vivo Papp for mannitol and inulin. Although I/R injury was accompanied by significant histological disruption, there was no observable alteration in dextran permeability, suggesting that the loss in normal barrier function was limited to low-molecular-weight compounds. Hemodynamic measurements indicated that reperfusion induced a precipitous and sustained fall in MAP. HR values fell sharply following reperfusion but gradually increased and eventually "overshot" to values greater than baseline. CONCLUSIONS: Our findings demonstrate the selective loss of barrier function of the small bowel following intestinal I/R. Furthermore, these results also illustrate the importance of selecting appropriate permeability markers for the evaluation of intestinal damage. In light of the significant hemodynamic disruption accompanying the animal model, our investigation also points toward the need for developing therapeutic strategies that mitigate the local and systemic effects of intestinal I/R injury. Copyright 2001 Academic Press.
PMID: 11421612

J Med Chem 2001 Jun 7;44(12):1927-37
Experimental and computational screening models for the prediction of intestinal drug absorption.
Stenberg P, Norinder U, Luthman K, Artursson P. Department of Pharmaceutics, Uppsala Biomedical Center, Uppsala University, P.O. Box 580, SE-751 23 Uppsala, Sweden.
The aim of this study was to devise experimental protocols and computational models for the prediction of intestinal drug permeability. Both the required experimental and computational effort and the accuracy and quality of the resulting predictions were considered. In vitro intestinal Caco-2 cell monolayer permeabilities were determined both in a highly accurate experimental setting (Pc) and in a faster, but less accurate, mode (Papp). Computational models were built using four different principles for generation of molecular descriptors (atom counts, molecular mechanics calculations, fragmental, and quantum mechanics approaches) and were evaluated for their ability to predict intestinal membrane permeability. A theoretical deconvolution of the polar molecular surface area (PSA) was also performed to facilitate the interpretation of this composite descriptor and allow the calculation of PSA in a simplified and fast mode. The results indicate that it is possible to predict intestinal drug permeability from rather simple models with little or no loss of accuracy. A new, fast computational model, based on partitioned molecular surface areas, that predicts intestinal drug permeability with an accuracy comparable to that of time-consuming quantum mechanics calculations is presented.
PMID: 11384238

Inflamm Bowel Dis 2001 May;7(2):94-8
Zinc supplementation tightens "leaky gut" in Crohn's disease.
Sturniolo GC, Di Leo V, Ferronato A, D'Odorico A, D'Inca R. Dipartimento di Scienze Chirurgiche e Gastroenterologiche, Universita di Padova, Italy. gsturn@ux1.unipd.it
OBJECTIVES: Small intestinal permeability is often increased in patients with Crohn's disease and may be pathogenic for clinical relapses. No effective prophylactic treatment is available for these patients. The aim of this study was to ascertain whether zinc supplementation may improve intestinal permeability. METHODS: We studied 12 patients with quiescent Crohn's disease who had been in remission for at least 3 months and had increased intestinal permeability on two separate occasions within the last 2 months. Patients received oral zinc sulfate supplements (110 mg three times a day) for 8 weeks and were followed-up for 12 months thereafter to monitor relapses. RESULTS: We found that the lactulose/mannitol ratio was significantly higher before supplementation than after (0.041 +/- 0.003 versus 0.026 +/- 0.005). During follow-up, 10 patients had normal intestinal permeability and did not relapse; of the remaining two who had increased intestinal permeability, one relapsed. CONCLUSIONS: Our findings show that zinc supplementation can resolve permeability alterations in patients with Crohn's disease in remission. Improving intestinal barrier function may contribute to reduce the risk of relapse in Crohn's disease.
PMID: 11383597

Crit Care Med 2001 Apr;29(4):703-8

Comment in: Crit Care Med. 2001 Apr;29(4):899-901
Inosine improves gut permeability and vascular reactivity in endotoxic shock.
Garcia Soriano F, Liaudet L, Marton A, Hasko G, Batista Lorigados C, Deitch EA, Szabo C. Inotek Corporation, Beverly, MA, USA.
OBJECTIVE: To investigate the effects of inosine administration on vascular reactivity, gut permeability, neutrophil accumulation and lipid peroxidation in tissues in murine endotoxin shock. DESIGN: Randomized, prospective laboratory study. SETTING: Research laboratory. SUBJECTS: BALB/c mice 6-8 wks age. INTERVENTIONS: BALB/c mice were randomly assigned to one of five groups: a) vehicle controls, which received saline intraperitoneally; b) inosine controls, which received inosine alone (100 mg/kg, ip); c) lipopolysaccharide (LPS)-treated animals, which received LPS (40 and 100 mg/kg, ip, depending on the experimental protocol); d) inosine pretreatment group, which received inosine (100 mg/kg, ip) 30 mins before LPS; and finally, e) inosine posttreatment group, which received inosine (100 mg/kg, ip) 60 mins after LPS. MEASUREMENTS AND MAIN RESULTS: The passage of fluorescein isothiocyanate-conjugated dextran (4 kDa, FD4) was analyzed in everted gut ileal sacs incubated ex vivo as an index of gut permeability. LPS induced a significant intestinal hyperpermeability, and inosine exerted protective effects both in pre- and posttreatment regimens. Myeloperoxidase and malondialdehyde were also measured to study neutrophil accumulation and lipid peroxidation in selected tissues. Inosine, both in pre- and posttreatment regimens ameliorated the increases in myeloperoxidase and malondialdehyde in the lung and gut. LPS-treated animals showed decreased contractile and relaxant responses, and inosine pretreatment (but not posttreatment) partially improved these responses. CONCLUSIONS: Taken together, inosine has organ protective effects during shock. A significant portion of its protective action is maintained even in the posttreatment scenario.
PMID: 11373452

J Cancer Res Clin Oncol 2001 May;127(5):314-8
Intestinal permeability in patients with chemotherapy-induced stomatitis.
Melichar B, Kohout P, Bratova M, Solichova D, Kralickova P, Zadak Z. Department of Oncology and Radiotherapy, Charles University Medical School and Teaching Hospital, Building 23, 50005 Hradec Kralove, Czech Republic. melichar@fnhk.cz
PURPOSE: Mucositis represents one of the most common side effects of chemotherapy, and may affect any part of the gastrointestinal tract, resulting in stomatitis, dysphagia, dyspepsia, or diarrhea. The aim of the present study was to evaluate intestinal permeability in patients with stomatitis during treatment with oral granulocyte-monocyte colony-stimulating factor (GM-CSF, Leucomax). METHODS: Ten patients with chemotherapy-induced stomatitis and 21 control cancer patients were included in the study. Intestinal permeability in patients with stomatitis was evaluated before and after the treatment with oral GM-CSF (200 micrograms for 4 consecutive days) by measuring urinary lactulose, D-xylose, and mannitol after oral challenge in collected urine using capillary gas chromatography. RESULTS: Mean grade of stomatitis (3, range 2-3) improved during treatment by a mean of 1 grade (range 0-2, sign test P < 0.05) with an improvement observed in eight of ten patients. Lactulose excretion, lactulose/mannitol, and lactulose/xylose ratios were markedly elevated in the patients with mucositis compared with 21 control cancer patients (1.60 +/- 1.04%, 0.2446 +/- 0.2937, and 0.3877 +/- 0.6808 vs 0.35 +/- 0.20%, 0.0332 +/- 0.0148, and 0.0255 +/- 0.0086, respectively, Mann Whitney U-test, P < 0.001). After treatment, lactulose excretion, lactulose/mannitol, and lactulose/xylose ratio decreased significantly (1.60 +/- 1.04 vs 0.63 +/- 0.42%; 0.2446 +/- 0.2937 vs 0.1303 +/- 0.1149; and 0.3877 +/- 0.6808 vs 0.1126 +/- 0.1146, respectively, P < 0.05). CONCLUSIONS: Lactulose excretion after oral challenge, lactulose/mannitol, or lactulose/xylose ratio may be useful markers for intestinal involvement in chemotherapy-induced mucositis. Improvement of oral mucositis was associated with a significant decrease of intestinal permeability to lactulose. Testing of intestinal permeability by the present method may be useful to evaluate the effect of therapeutic interventions in patients with chemotherapy-induced mucositis.
PMID: 11355146

Am J Physiol Gastrointest Liver Physiol 2001 Jun;280(6):G1234-46
iNOS upregulation mediates oxidant-induced disruption of F-actin and barrier of intestinal monolayers.
Banan A, Fields JZ, Zhang Y, Keshavarzian A. Division of Digestive Diseases, Department of Internal Medicine, Rush University Medical Center, Chicago, Illinois 60612, USA. ali_banan@rush.edu
Using oxidant-induced hyperpermeability of monolayers of intestinal (Caco-2) cells as a model for the pathophysiology of inflammatory bowel disease (IBD), we previously showed that oxidative injury to the F-actin cytoskeleton is necessary for the disruption of monolayer barrier integrity. We hypothesized that this cytoskeletal damage is caused by upregulation of an inducible nitric oxide (NO) synthase (iNOS)-driven pathway that overproduces reactive nitrogen metabolites (RNMs) such as NO and peroxynitrite (OONO(-)), which cause actin nitration and disassembly. Monolayers were exposed to H(2)O(2) or to RNMs with and without pretreatment with antioxidants or iNOS inhibitors. H(2)O(2) concentrations that disassembled and/or disrupted the F-actin cytoskeleton and barrier integrity also caused rapid iNOS activation, NO overproduction, and actin nitration. Added OONO(-) mimicked H(2)O(2); iNOS inhibitors and RNM scavengers were protective. Our results show that oxidant-induced F-actin and intestinal barrier disruption are caused by rapid iNOS upregulation that further increases oxidant levels; a similar positive feedback mechanism may underlie the episodic recurrence of the acute IBD attack. Confirming these mechanisms in vivo would provide a rationale for developing novel anti-RNM therapies for IBD.
PMID: 11352817

Clin Sci (Lond) 2001 Jun;100(6):627-33
Co-administration of the health food supplement, bovine colostrum, reduces the acute non-steroidal anti-inflammatory drug-induced increase in intestinal permeability.
Playford RJ, MacDonald CE, Calnan DP, Floyd DN, Podas T, Johnson W, Wicks AC, Bashir O, Marchbank T. Department of Gastroenterology, Imperial College School of Medicine, Hammersmith Hospital, Du Cane Road, London W120NN, UK. r.playford@ic.ac.uk
Non-steroidal anti-inflammatory drugs (NSAIDs) are effective analgesics but cause gastrointestinal injury. Present prophylactic measures are suboptimal and novel therapies are required. Bovine colostrum is a cheap, readily available source of growth factors, which reduces gastrointestinal injury in rats and mice. We therefore examined whether spray-dried, defatted colostrum could reduce the rise in gut permeability (a non-invasive marker of intestinal injury) caused by NSAIDs in volunteers and patients taking NSAIDs for clinical reasons. Healthy male volunteers (n=7) participated in a randomized crossover trial comparing changes in gut permeability (lactulose/rhamnose ratios) before and after 5 days of 50 mg of indomethacin three times daily (tds) per oral with colostrum (125 ml, tds) or whey protein (control) co-administration. A second study examined the effect of colostral and control solutions (125 ml, tds for 7 days) on gut permeability in patients (n=15) taking a substantial, regular dose of an NSAID for clinical reasons. For both studies, there was a 2 week washout period between treatment arms. In volunteers, indomethacin caused a 3-fold increase in gut permeability in the control arm (lactulose/rhamnose ratio 0.36+/-0.07 prior to indomethacin and 1.17+/-0.25 on day 5, P<0.01), whereas no significant increase in permeability was seen when colostrum was co-administered. In patients taking long-term NSAID treatment, initial permeability ratios were low (0.13+/-0.02), despite continuing on the drug, and permeability was not influenced by co-administration of test solutions. These studies provide preliminary evidence that bovine colostrum, which is already currently available as an over-the-counter preparation, may provide a novel approach to the prevention of NSAID-induced gastrointestinal damage in humans.
Publication Types:

Clinical trial

Randomized controlled trial

PMID: 11352778