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1.
Endoscopy ; 41(11): 965-70, 2009 Nov.
Article in English | MEDLINE | ID: mdl-19866394

ABSTRACT

BACKGROUND AND STUDY AIMS: Endoscopic biopsies have a low sensitivity for diagnosing malignant bile duct strictures. Tumor markers detected by mucin staining and immunohistochemistry may help to determine the malignancy of a biopsy specimen where histologic evaluation alone is nondiagnostic. PATIENTS AND METHODS: 61 patients who underwent forceps biopsies were retrospectively identified, yielding 49 and 40 biopsy specimens for strictures finally diagnosed as benign and malignant, respectively. Biopsy specimens were histologically evaluated and stained for p53, Ki-67, carcinoembryonic antigen (CEA), CA19-9, CAM5.2, and presence of intracytoplasmic lumina (ICL). Sensitivity, specificity, positive and negative predictive values (PPV and NPV), and positive and negative likelihood ratios (PLR and NLR) were calculated to evaluate the performance of each test. RESULTS: Histology alone provided sensitivity and specificity of 53 % and 100 %. Addition of ICL or CAM5.2 increased sensitivity to 73 % or 60 %, respectively, and provided excellent specificity, PPV, and PLR (ICL, 98 %, 97 %, and 36; CAM5.2, 100 %, 100 %, and infinite). Both stains in combination increased the sensitivity to 75 %. Staining for Ki-67, p53, CEA, and CA19-9 increased the sensitivity to detect malignancy (range 60 % to 83 %), but significantly reduced the specificity, PPV and PLR (ranges 73 % to 90 %, 72 % to 86 %, and 3 to 7, respectively). Markers in all combinations performed poorly as a negative test (NPV 69 % to 87 %, and NLR 0.19 to 0.55). CONCLUSIONS: Staining for tumor markers ICL and CAM5.2 can improve the diagnostic value of endoscopic biopsies, and may change the course of management for patients with indeterminate histological findings.


Subject(s)
Bile Duct Neoplasms/pathology , Bile Ducts/pathology , Adult , Aged , Aged, 80 and over , Biomarkers , Biopsy , Female , Humans , Keratins , Male , Middle Aged , Sensitivity and Specificity , Staining and Labeling
2.
Endoscopy ; 40(5): 388-92, 2008 May.
Article in English | MEDLINE | ID: mdl-18459075

ABSTRACT

BACKGROUND AND STUDY AIMS: Radiofrequency ablation is a rapidly evolving therapeutic modality for Barrett's esophagus. The aim of this ongoing 12-month trial is to assess Barrett's esophagus eradication after radiofrequency ablation using a balloon-based (HALO-360) and a plate-based (HALO-90) device. We report here our experience with the first 10 patients (out of 40) who have completed 12 months of follow-up. PATIENTS AND METHODS: Following radiofrequency ablation using the HALO-360 device all patients were maintained on double-dose proton pump inhibitor therapy. Endoscopic evaluation was performed at 3 and 12 months postablation. Patients with residual Barrett's esophagus at 3 months underwent repeat ablation. Ten patients, seven with nondysplastic Barrett's esophagus, two with low-grade and one with high-grade dysplasia have completed the study to date. RESULTS: Complete Barrett's esophagus eradication was achieved in seven patients, and partial eradication was achieved in three. There were no major complications. One case of buried Barrett's metaplasia was encountered and successfully re-ablated, with complete Barrett's esophagus eradication achieved at 12 months. CONCLUSIONS: In this study, Barrett's eradication rates were comparable to previously published reports. One case of buried Barrett's metaplasia was identified out of 247 biopsies and was eradicated with repeat ablation.


Subject(s)
Barrett Esophagus/pathology , Barrett Esophagus/surgery , Catheter Ablation , Endoscopy, Digestive System , Adult , Aged , Catheter Ablation/instrumentation , Catheterization/instrumentation , Endoscopes, Gastrointestinal , Female , Follow-Up Studies , Humans , Male , Middle Aged , Pilot Projects , Prospective Studies , Treatment Outcome
3.
Scand J Gastroenterol ; 37(4): 414-22, 2002 Apr.
Article in English | MEDLINE | ID: mdl-11989832

ABSTRACT

BACKGROUND: Capsaicin-sensitive nerve fibres protect gastrointestinal mucosa in animal models of mucosal injury by modulation of mucosal blood flow and mucus secretion. The aim of our study was to evaluate the effects of capsaicin-sensitive nerve fibres in rat colonic mucosa on epithelial cell proliferation and transforming growth factor-alpha (TGFalpha) expression, which is important in mucosal defence, protection and repair. METHODS: Male Wistar rats received either a capsaicin enema with or without giving antagonists to calcitonin-gene-related-peptide (CGRP) or substance P (SP) i.v. immediately prior to the capsaicin enemas; a capsaicin enema after sensory desensitization as described previously; or a vehicle enema. In all experiments, animals received 50 mg/kg BrdU i.v. and were killed at 2, 4, 8, 12, 24 and 48 h after the various treatments. Colonic mucosal specimens were evaluated microscopically for mucosal damage, changes in the numbers of inflammatory cells and BrdU-immunoreactive epithelial cell nuclei. In the same specimens, TGFalpha-mRNA and -protein expression were evaluated by RT-PCR and Western blot analysis using standardized procedures. RESULTS: A significant increase in the number of mucosal inflammatory cells and an increase in BrdU-immunoreactive nuclei were detected following mucosal exposure to capsaicin. A 2-fold increase of TGFalpha mRNA and a 10-fold increase of TGFalpha protein expression were obtained 2-12 h after capsaicin enemas. The effects on the invading number of inflammatory cells and on the increase in BrdU immunoreactive epithelial cell nuclei were significantly reduced by both CGRP and SP antagonists and were abolished in rats previously sensory-desensitized. CONCLUSION: Capsaicin-sensitive nerve fibres modulate epithelial cell proliferation and TGFalpha expression in colonic mucosa as well as a migration of inflammatory cells into the colonic mucosa. These effects are mediated by the neurotransmitters CGRP and SP.


Subject(s)
Capsaicin/pharmacology , Cell Division/physiology , Colon/innervation , Intestinal Mucosa/cytology , Intestinal Mucosa/metabolism , Nerve Fibers/physiology , Transforming Growth Factor alpha/biosynthesis , Animals , Blotting, Western , Bromodeoxyuridine/metabolism , Calcitonin Gene-Related Peptide/antagonists & inhibitors , Calcitonin Gene-Related Peptide/physiology , Colon/cytology , Colon/metabolism , Denervation , Goblet Cells/cytology , Goblet Cells/drug effects , Goblet Cells/pathology , Immunohistochemistry , Inflammation/pathology , Intestinal Mucosa/pathology , Male , Nerve Fibers/drug effects , Peroxidase/metabolism , RNA, Messenger/analysis , Rats , Rats, Wistar , Reverse Transcriptase Polymerase Chain Reaction , Substance P/antagonists & inhibitors , Substance P/physiology , Transforming Growth Factor alpha/genetics
4.
Scand J Gastroenterol ; 36(3): 276-82, 2001 Mar.
Article in English | MEDLINE | ID: mdl-11305515

ABSTRACT

BACKGROUND: Transforming growth factor-alpha (TGF-alpha) is a key mediator of colonic mucosal protection and/or repair mechanisms in orally induced acute dextran sodium sulphate (DSS) colitis. However, it also has been suggested that TGF-alpha may contribute to malignant transformation in the colon. The aim of the studies was to determine whether TGF-alpha is needed for malignant transformation in orally induced chronic DSS colitis using TGF-alpha deficient mice (wa-1) and Balb/c mice, a strain competent in TGF-alpha. METHODS: Chronic colitis was induced by oral administration of DSS (5%) for 7 days followed by drinking water for 10 days in wa-1 and Balb/c mice (n = 20, per group). In the two subsequent cycles (7 days DSS, 10 days water) 3% DSS-water was utilized due to a high mortality in the wa-1 group. Mucosal injury severity was assessed histologically and graded (three grades). A crypt damage score (CDS) reflecting all three grades of mucosal pathology was calculated. Mucosal dysplasia and cancerous lesions were noted. RESULTS: Seven per cent of the entire colonic mucosa was completely destroyed in wa-1 animals compared to 3% in Balb/c mice (P < 0.05). The CDS was 10.2 +/- 0.4 and 4.8 +/- 0.3 in wa-1 and Balb/c mice, respectively (P < 0.05). Fifteen incidences of mucosal dysplasia were found in the 10 surviving wa-1 animals and 31 incidences were found in 20 Balb/c animals. In both groups, one fully developed adenomatous cancerous lesion was present. CONCLUSIONS: The markedly increased severity of mucosal injury in chronic induced DSS colitis in TGF-alpha deficient wa-1 mice compared to Balb/c mice further substantiates that endogenous TGF-alpha is a pivotal mediator of protection and/or healing mechanisms in the colon. The appearance of dysplastic and cancerous lesions in TGF-alpha deficient animals suggests that TGF-alpha per se is not essential for malignant mucosal cell transformation in colitis.


Subject(s)
Cell Transformation, Neoplastic/pathology , Colitis/pathology , Intestinal Mucosa/pathology , Transforming Growth Factor alpha/analysis , Animals , Chronic Disease , Dextran Sulfate , Disease Models, Animal , Female , Male , Mice , Mice, Inbred BALB C , Mice, Inbred Strains , Probability , Radioimmunoassay , Sensitivity and Specificity , Severity of Illness Index , Statistics, Nonparametric
5.
Digestion ; 62(4): 240-8, 2000.
Article in English | MEDLINE | ID: mdl-11070407

ABSTRACT

BACKGROUND/AIMS: In our experience with the acute murine dextran sodium sulphate (DSS) model of experimental colitis, we noted both interstrain and interanimal variations in daily water consumption. One might critically question whether observed differences in injuries are just a dose dependency phenomenon reflecting variations in DSS intake. To clarify this important topic, we performed a dose and concentration dependency study of DSS in Balb/c mice. We also determined Th1 and Th2 cytokine levels to compare the cytokine profile to that from inflammatory bowel disease (IBD). METHODS: In four groups (14 animals each group) different concentrations of DSS (0, 2.5, 5 and 7.5%) were given for 7 days ad libitum. Mucosal injury of the entire colon was histologically assessed and graded. Cytokine levels were determined by competitive quantitative RT-PCR. RESULTS: A linear increase in the crypt damage score was noted with increasing concentrations (0, 4.9 +/- 0.7, 11.9 +/- 0.5 and 18.9 +/- 1.3, respectively), but the total dose of DSS intake did not correlate with mucosal damage. Progressive upregulation in the transcripts for Th1 cytokines (IL-12, IFN-gamma, IL-1, TNF-alpha) was observed with increasing dosage of DSS. Interestingly, an increase in IL-10, but not IL-4 mRNA transcripts was also noted. DISCUSSION: Acute DSS-induced mucosal injury is dependent on the administered DSS water concentration but not on the consumed DSS dose. The cytokine profile is a classic Th1 response and is similar to that of various inflammatory conditions in the colon. CONCLUSIONS: Minor variations in fluid consumption do not affect the severity of DSS-induced injury in mice. The acute murine DSS colitis model is useful for studying the pathophysiological aspects of colonic inflammatory diseases as IBD and for evaluating new potential therapeutic agents


Subject(s)
Antiviral Agents/adverse effects , Colitis/physiopathology , Cytokines/analysis , Dextran Sulfate/adverse effects , Animals , Antiviral Agents/administration & dosage , Colitis/veterinary , Dextran Sulfate/administration & dosage , Disease Models, Animal , Dose-Response Relationship, Drug , Drinking , Female , Mice , Mice, Inbred BALB C , Reverse Transcriptase Polymerase Chain Reaction , Severity of Illness Index
6.
Gastroenterology ; 119(2): 368-76, 2000 Aug.
Article in English | MEDLINE | ID: mdl-10930372

ABSTRACT

BACKGROUND & AIMS: Sensory neuropeptides modulate the mucosal response to inflammation in experimental colitis. Because nerve growth factor (NGF) regulates the expression of neuropeptides such as substance P and calcitonin gene-related peptide (CGRP) and is implicated as a link between the nervous system and the immune system in the inflammatory process, we investigated the functional role of NGF and neurotrophin-3 during experimental colitis. METHODS: Immunoneutralizing antibodies specific for NGF and neurotrophin (NT)-3 were used to block their endogenous activity. Mild trinitrobenzene sulfonic acid (TNBS) colitis was induced, and damage scores were assessed after 1 week. Neuropeptide content in the colon and NT messenger RNA (mRNA) expression were determined. RESULTS: The pretreatment with anti-NGF or anti-NT-3 caused a significant 2-3-fold increase in the severity of the experimental inflammation as assessed by a macroscopic damage score, histologic ulceration score, and myeloperoxidase activity in the tissue. CGRP, but not substance P, contents in the colon were significantly reduced by NGF immunoneutralization. NGF mRNA was slightly up-regulated after NGF immunoneutralization, but NT-3 mRNA was unchanged by NT-3 immunoneutralization. CGRP mRNA was not significantly changed after 1 week of colitis by NGF or NT-3 immunoneutralization, whereas beta-preprotachykinin mRNA was up-regulated after immunoneutralization. CONCLUSIONS: These findings suggest a regulatory role for NGF and NT-3 in experimental inflammation of the gut. This effect may be partly caused by the reduction of mucosal CGRP content caused by the NGF blockade.


Subject(s)
Colitis/immunology , Nerve Growth Factor/immunology , Neurotrophin 3/immunology , Animals , Antibodies/pharmacology , Calcitonin Gene-Related Peptide/genetics , Colitis/chemically induced , Colon/chemistry , Colon/immunology , Colon/innervation , Gene Expression/drug effects , Gene Expression/immunology , Male , Nerve Growth Factor/genetics , Neurotrophin 3/genetics , Neutralization Tests , Protein Precursors/genetics , RNA, Messenger/analysis , Rats , Rats, Sprague-Dawley , Receptor, trkA/genetics , Receptor, trkC/genetics , Substance P/genetics , Tachykinins/genetics , Trinitrobenzenesulfonic Acid
8.
J Neurochem ; 74(5): 2127-33, 2000 May.
Article in English | MEDLINE | ID: mdl-10800958

ABSTRACT

Examination of commercial recombinant human beta-nerve growth factor (rh-beta-NGF) preparations with polyclonal antibodies specific to 13-kDa NGF and pro-NGF-specific domains revealed the presence of high-molecular-mass immunoreactive proteins, including a 60-kDa NGF prohormone. On incubation with a mixture of N- and O-specific glycosidases, the 60-kDa NGF pro-hormone generated a 32-kDa protein corresponding to the molecular size of NGF precursor predicted by the cloned human NGF cDNA. Highly sensitive chemiluminescence immunoblot analysis of adult rat dorsal root ganglia, spinal cord, and colon tissues with NGF- and pro-NGF domain-specific antibodies also revealed the presence of high-molecular-mass proteins, including the 60-kDa NGF prohormone. Based on the presence of the 60-kDa NGF prohormone in dorsal root ganglia and its efferent tissues, we suggest that proteolytically unprocessed, glycosylated NGF prohormone may mediate interactions between neurons and the tissues they innervate.


Subject(s)
Ganglia, Spinal/chemistry , Nerve Growth Factor/analysis , Nerve Growth Factor/chemistry , Protein Precursors/analysis , Animals , Colon/chemistry , Humans , Immunoblotting , Luminescent Measurements , Molecular Weight , Protein Precursors/chemistry , Rats , Rats, Sprague-Dawley , Recombinant Proteins/chemistry , Spinal Cord/chemistry
9.
Scand J Gastroenterol ; 35(11): 1174-80, 2000 Nov.
Article in English | MEDLINE | ID: mdl-11145289

ABSTRACT

BACKGROUND: Epidermal growth factor and related proteins share some structural homology and bind to one common receptor. We have shown previously that exogenously applied EGF protects colonic mucosa against injury in an experimental model of colitis in rats and that the endogenously expressed ligands for the EGF-receptor are predominantly transforming growth factor alpha precursors. The aim of our present study was to evaluate the EGF-receptor expression in response to mucosal injury in the same model of colitis. METHODS: The trinitrobenzene sulphonic acid (TNBS)/ethanol-induced model of colitis in rats was used and EGF-receptor expression was evaluated using ribonuclease protection assay and Western blot analysis. The extent of mucosal injury and inflammation was characterized by using a microscopic and macroscopic damage score and by estimation of the myeloperoxidase activity in colonic specimens. RESULTS: Irritation of the colonic mucosa leads to severe colonic inflammation with tissue oedema, erosions and mucosal ulcers and to a significant increase in myeloperoxidase activity expressed by neutrophil granulocytes and macrophages. A significant increase in EGF-receptor mRNA expression was obtained at 8-24 h followed by an increased expression of the EGF-receptor protein at 1-5 days after the induction of colitis. On Western blot analysis only one immunoreactive band with a molecular weight of approximately 170 kDa was detected. CONCLUSIONS: Mucosal inflammation leads to a significant increase in the EGF-receptor expression in the early phases of colitis. These findings support our hypothesis that EGF and related proteins and their common receptor play a pivotal role in mucosal defence and repair.


Subject(s)
Colitis/metabolism , Colon/metabolism , ErbB Receptors/metabolism , Actins/metabolism , Animals , Blotting, Western , Colitis/pathology , Colon/pathology , Male , Nuclease Protection Assays , Peroxidase/metabolism , RNA, Messenger/analysis , Rats , Rats, Sprague-Dawley
10.
Scand J Gastroenterol ; 35(11): 1181-7, 2000 Nov.
Article in English | MEDLINE | ID: mdl-11145290

ABSTRACT

BACKGROUND: It has been reported that epithelial growth factor (EGF) and transforming growth factor-alpha (TGF-alpha) play an important role in colonic mucosal defense and repair. Waved-2 (wa-2) mice harboring a defect EGF-R and phenotypically similar to TGF-alpha knockout mice provide a novel approach to study the role of EGF-R ligands in the maintenance and repair of colonic mucosa. METHODS: Acute colonic mucosal injury was induced by oral administration of dextran sodium sulfate (DSS: 5 g%) given for 6 days ad libitum to wa-2 homozygotes and their genetic controls (n = 10, each group), as well as to wa-2 mice with and without exogenous EGF administration. Severity of colonic injury was assessed histologically of the entire colon and graded. A crypt damage score (CDS) reflecting all three grades of mucosal pathology was calculated. Decrease in total body weight, colon length and colonic blood content was determined for all groups. RESULTS: Thirty-eight percent of the entire colonic mucosa was destroyed in wa-2 animals compared to 15% in control mice. The CDS was 16.0 +/- 1.4 and 9.6 +/- 0.8 in wa-2 and control mice, respectively. EGF application to wa-2 mice did not reduce the severity of mucosal injury (CDS: 18.9 +/- 1.7 and 19.4 +/- 2.1 in EGF and vehicle injected mice, respectively). CONCLUSIONS: The increased susceptibility of wa-2 mice to DSS demonstrates the pivotal role of EGF-R ligands such as EGF and TGF-alpha in preserving the integrity of the colonic mucosa against mucosal injury. The missing beneficial effect of exogenous EGF administration in these mice further underlines the importance of an intact ligand/EGF-R pathway.


Subject(s)
Colitis/genetics , Dextran Sulfate , ErbB Receptors/genetics , Animals , Colitis/chemically induced , Colitis/metabolism , Colitis/pathology , Colon/pathology , Epidermal Growth Factor/pharmacology , ErbB Receptors/metabolism , Female , Genetic Predisposition to Disease , Homozygote , Intestinal Mucosa/pathology , Mice , Mice, Knockout , Mice, Mutant Strains , Transforming Growth Factor alpha/genetics
11.
Eur J Gastroenterol Hepatol ; 11(11): 1305-10, 1999 Nov.
Article in English | MEDLINE | ID: mdl-10563545

ABSTRACT

OBJECTIVE/BACKGROUND: Non-mitogenic biological activity such as modulation of mucosal blood flow is suspected to convey the protective effects of epidermal growth factor (EGF) in vivo. The aims of our present study were to determine the effects of EGF on colonic mucosal blood flow and injury induced hyperaemia in rats. DESIGN/METHODS: Rats were pretreated with i.p. injections of vehicle, EGF, or indomethacin and EGF prior to mucosal injury. Basal mucosal blood flow and injury induced hyperaemia at the border of the damaged mucosa was determined by using reflectance spectrophotometry. RESULTS: EGF significantly increased basal mucosal blood flow but did not further enhance injury induced hyperaemia. The EGF induced increase in basal mucosal blood flow was completely abolished by indomethacin pretreatment. CONCLUSIONS: EGF induces an increase of basal mucosal blood flow through induction of prostaglandin synthesis. We hypothesize that the increase in mucosal blood flow contributes to the ability of EGF to protect the colonic mucosa against injury.


Subject(s)
Colon/blood supply , Epidermal Growth Factor/pharmacology , Intestinal Mucosa/drug effects , Prostaglandins/physiology , Regional Blood Flow/drug effects , Animals , Blood Pressure/drug effects , Colon/drug effects , Colon/pathology , Cyclooxygenase Inhibitors/pharmacology , Indomethacin/pharmacology , Intestinal Mucosa/blood supply , Intestinal Mucosa/pathology , Male , Rats , Rats, Sprague-Dawley , Regional Blood Flow/physiology
13.
Dig Dis Sci ; 44(4): 836-44, 1999 Apr.
Article in English | MEDLINE | ID: mdl-10219846

ABSTRACT

Keratinocyte growth factor (KGF) is emerging as an important mediator of mucosal defense and repair in the colon. The aim of the present study was to evaluate and further characterize the effects of exogenous KGF administration utilizing the dextran sodium sulfate (DSS) model of colitis in mice. Colitis was induced via oral administration of DSS (5 g/100 ml) to Balb/c mice for eight days. Intraperitoneal administration of KGF (5 mg/kg, once daily) or vehicle (VEH) was initiated 1 hr prior to the induction of the colitis (N = 10, each group). Mucosal injury of the entire colon was histologically assessed and graded. An approximately fourfold reduction in the crypt damage score was noted in the KGF group when compared to controls (VEH) (2.8 +/- 1.03 and 11.4 +/- 0.78, respectively). The significant reduction of mucosal injury in KGF treated mice confirms that KGF is a key mediator maintaining the integrity of the colonic mucosa.


Subject(s)
Colitis, Ulcerative/prevention & control , Fibroblast Growth Factors , Growth Substances/therapeutic use , Intestinal Mucosa/drug effects , Animals , Colitis, Ulcerative/chemically induced , Colitis, Ulcerative/pathology , Dextran Sulfate , Disease Models, Animal , Female , Fibroblast Growth Factor 10 , Fibroblast Growth Factor 7 , Growth Substances/administration & dosage , Growth Substances/pharmacology , Injections, Intraperitoneal , Intestinal Mucosa/pathology , Mice , Mice, Inbred BALB C , Wound Healing/drug effects
15.
Gut ; 43(1): 64-70, 1998 Jul.
Article in English | MEDLINE | ID: mdl-9771407

ABSTRACT

BACKGROUND: Transforming growth factor alpha (TGF-alpha) knockout mice have increased susceptibility to dextran sodium sulphate (DSS) induced colitis. AIM: To substantiate the findings that TGF-alpha is a key mediator of colonic mucosal protection and/or repair mechanisms by evaluating the susceptibility of mice overexpressing TGF-alpha to DSS induced colitis. METHODS: TGF-alpha overexpression was induced in transgenic mice by ZnSO4 administration in drinking water (TG+). Three groups were used as controls: one transgenic group without ZnSO4 administration (TG-), and two non-transgenic littermate groups receiving ZnSO4 (Non-TG+) or only water (Non-TG-). Acute colitis was induced in all groups by administration of DSS (5%, w/v) in drinking water for six days and libitum. RESULTS: About 35-39% of the entire colonic mucosa was destroyed in Non-TG-, Non-TG+, and TG- animals compared with 9% in TG+ mice. the crypt damage score was 18.7 (0.9), 18.2 (1.0), 18.9 (0.8), and 6.8 (1.5) (means (SEM)) in Non-TG-, Non-TG+, TG-, and TG+ mice respectively. Mucin and bromodeoxyuridine staining were markedly enhanced in colons of TG+ mice compared with controls, indicating increased mucosal protection and regeneration. CONCLUSIONS: The significantly reduced susceptibility of mice overexpressing TGF-alpha to DSS further substantiates that endogenous TGF-alpha is a pivotal mediator of protection and/or healing mechanisms in the colon.


Subject(s)
Colitis/metabolism , Transforming Growth Factor alpha/physiology , Acute Disease , Animals , Body Weight , Cell Division , Colitis/chemically induced , Colitis/pathology , Colon/metabolism , Colon/pathology , Dextran Sulfate , Disease Susceptibility , Intestinal Mucosa/metabolism , Intestinal Mucosa/pathology , Male , Mice , Mice, Transgenic , Radioimmunoassay , Statistics, Nonparametric , Transforming Growth Factor alpha/analysis , Zinc/administration & dosage
16.
J Pharmacol Exp Ther ; 286(2): 657-61, 1998 Aug.
Article in English | MEDLINE | ID: mdl-9694917

ABSTRACT

Recently we demonstrated that sensory denervation with the neurotoxin capsaicin worsened the inflammation in an acute and chronic model of experimental colitis, which suggests a protective role of sensory nerve fibers during gut inflammation. Because we could demonstrate that sensory neuropeptides like Calcitonin gene-related peptide (CGRP) and substance P (SP) are released from sensory nerve fibers during intestinal inflammation, both are strong candidates as mediators for the protective effect of sensory neurons. In this study we investigate the role of CGRP and SP during experimental colitis in the rat by use of receptor antagonists against CGRP (CGRP 8-37, 1 microg/h continuous subcutaneous infusion), SP (RP67580, a NK-1 receptor antagonist, 3 mg/kg i.p.) and an immunoneutralizing CGRP-antibody. A mild colitis was induced by a rectal enema containing trinitrobenzenesulfonic acid. The severity of inflammation increased markedly after 7 days in the CGRP receptor antagonist and CGRP-antibody group compared with the vehicle group as determined by a macroscopic damage score (10.4 +/- 1.2 and 9.6 +/- 1.6 vs. 6.2 +/- 2.1) by a histologic ulceration score (82 +/- 8% and 73 +/- 6% vs. 42 +/- 23%) and by myeloperoxidase activity (19.2 +/- 6.8 and 18.1 +/- 5.9 vs. 8.6 +/- 5.3 U/mg tissue protein), respectively. Treatment with the specific SP receptor antagonist did not significantly alter the severity of colitis at 7 days compared with the control group. These data suggest that CGRP exerts mucosal protection during chronic experimental colitis.


Subject(s)
Calcitonin Gene-Related Peptide/physiology , Colitis, Ulcerative/physiopathology , Neurons, Afferent/physiology , Animals , Antibodies, Monoclonal , Chronic Disease , Colitis, Ulcerative/pathology , Indoles/pharmacology , Isoindoles , Male , Neurokinin-1 Receptor Antagonists , Neurons, Afferent/drug effects , Protein Biosynthesis , Rats , Rats, Wistar , Substance P/physiology
17.
Am J Surg ; 176(1): 18-24, 1998 Jul.
Article in English | MEDLINE | ID: mdl-9683126

ABSTRACT

BACKGROUND: Inadequate healing and consequent leakage from bowel anastomoses are a significant cause of postoperative morbidity and mortality. Systemic application of keratinocyte growth factor (KGF) has been shown to promote mucosal healing in models of colitis in rats and mice. The aim of the present study was to evaluate the effect of systemic KGF administration on healing of colonic anastomoses in rats. METHODS: Rats underwent laparotomy, division of the left colon, and sigmoido-sigmoidostomy. KGF (5 mg/kg) or vehicle were administered intraperitoneally in two groups (n = 30 per group) 12 hours prior to surgery, and then once daily until sacrifice (6 animals per group; 2, 4, 7, 12, and 21 days after surgery). Bursting pressure measurements, histologic evaluation, morphometric analysis, mucin and collagen staining, and hydroxyproline measurements of the anastomotic site were performed. RESULTS: Administration of KGF significantly increased anastomotic bursting pressure on postoperative days 2, 4, and 7 by 34%, 49%, and 19%, respectively. Histology, mucin staining, and measurements of the colonic crypt depth showed markedly less extended inflammation with an increased acidic mucin content and a significantly thickened mucosal layer in the KGF treated group when compared with vehicle-treated animals. CONCLUSIONS: KGF promotes healing of colonic anastomoses in rats during a 1-week postoperative period following large bowel surgery. KGF may be acting to accelerate host reparative processes as well as to enhance protection of the anastomotic wound bed by increased colonic epithelium proliferation, increased mucus production, and reduction of the inflammatory activity at the anastomotic site.


Subject(s)
Anastomosis, Surgical , Colon/surgery , Fibroblast Growth Factors , Growth Substances/pharmacology , Wound Healing/drug effects , Animals , Azo Compounds , Cell Division/drug effects , Colitis/prevention & control , Colon/metabolism , Colon/pathology , Eosine Yellowish-(YS) , Fibroblast Growth Factor 10 , Fibroblast Growth Factor 7 , Follow-Up Studies , Growth Substances/administration & dosage , Hydroxyproline/metabolism , Intestinal Mucosa/metabolism , Intestinal Mucosa/pathology , Intestinal Mucosa/surgery , Male , Methyl Green , Mice , Mucins/metabolism , Rats , Rats, Sprague-Dawley , Recombinant Proteins
18.
J Recept Signal Transduct Res ; 18(4-6): 265-80, 1998.
Article in English | MEDLINE | ID: mdl-9879061

ABSTRACT

Recent studies indicate increased insulin-like growth factor I (IGF-I) expression and altered expression of IGF binding proteins (IGFBP) in the bowel during experimental colitis. This study analyzes the cellular sites of altered IGF-I and IGFBP-expression in large bowel of rats with experimental colitis. Colitis was induced by colonic instillation of 2, 4, 6-trinitrobenzenesulfonic (TNB) acid in ethanol. Animals were sacrificed at 7 days after induction of colitis. Cryostat sections of colon from TNB-treated and control rats were hybridized with 35S-labeled antisense probes for IGF-I, IGFBP-3, IGFBP-4 and IGFBP-5. IGF-I mRNA was up-regulated in lamina propria cells, submucosa and smooth muscle of inflamed colon. IGFBP-3 mRNA was localized to lamina propria and was down-regulated in inflamed colon. IGFBP-4 and IGFBP-5 mRNAs were both up-regulated in inflamed colon. IGFBP-4 mRNA was increased in lamina propria, submucosa and smooth muscle, whereas IGFBP-5 mRNA was increased in smooth muscle. Increased IGF-I expression in mesenchymal layers of colon during experimental colitis supports the hypothesis that IGF-I contributes to hyperplasia and fibrosis in response to inflammation. Altered expression of IGFBP-3, IGFBP-4 and IGFBP-5 in specific bowel layers during colitis suggests that they play a role in modulating IGF-I action.


Subject(s)
Colitis/metabolism , Insulin-Like Growth Factor Binding Proteins/analysis , Insulin-Like Growth Factor I/analysis , Animals , Insulin-Like Growth Factor Binding Proteins/genetics , Insulin-Like Growth Factor I/genetics , Male , RNA, Messenger/analysis , Rats , Rats, Sprague-Dawley
19.
Langenbecks Arch Chir Suppl Kongressbd ; 115(Suppl I): 95-9, 1998.
Article in German | MEDLINE | ID: mdl-14518220

ABSTRACT

Inadequate healing and consequent leakage from large bowel anastomoses are a significant cause of morbidity and mortality following large bowel surgery. Systemic application of KGF has been shown to promote mucosal healing in models of colitis in rats and mice. The aim of the present study was to evaluate the effect of systemic Keratinocyte Growth Factor (KGF) administration on healing of colonic anastomoses in rats. Sprague-Dawley rats underwent laparotomy, division of the left colon and sigmoideo-sigmoideostomy. KGF (5 mg/kg) or its vehicle were administered intra-peritoneally 12 hours prior to surgery, and then once daily until sacrifice (2, 4, 7, 12 and 21 days after surgery). Bursting pressure measurements, histologic evaluation, morphometric analysis, mucin and collagen staining and hydroxyproline measurements of the anastomotic site were performed. Administration of KGF significantly increased anastomotic bursting pressure on postoperative day 2, 4 and 7 by +34%, +49% and +19%, respectively but not on day 12 and day 21. Histology, mucin staining and measurements of the colonic crypt depth showed markedly less extended inflammation, increased acidic mucin content and a significantly thickened mucosal layer in the KGF treated group when compared to vehicle treated animals. Hydroxyproline content and collagen staining were not different between KGF and vehicle treated animals. We conclude that KGF promotes healing of colonic anastomoses in rats during a one week postoperative period. KGF may be acting to accelerate host reparative processes as well as to enhance protection of the anastomotic wound bed by increased epithelium proliferation, increased mucus production and reduction of the inflammatory activity at the anastomotic site.


Subject(s)
Anastomosis, Surgical , Colon/surgery , Fibroblast Growth Factors/pharmacology , Wound Healing/drug effects , Animals , Fibroblast Growth Factor 7 , Rats , Rats, Sprague-Dawley
20.
J Neurosci Methods ; 76(1): 75-81, 1997 Sep 05.
Article in English | MEDLINE | ID: mdl-9334942

ABSTRACT

Highly sensitive chemiluminescence immunoblot analysis was utilized to examine the purity of mouse 2.5S-, beta- and 7S nerve growth factors as well as that of recombinant human beta-nerve growth factor obtained from commercial vendors. Three polyclonal antisera and two monoclonal antibodies to 13 kDa nerve growth factor (2.5S NGF and beta-NGF) were employed for assessing the purity of each preparation. In addition, polyclonal antisera against two prepro-NGF specific domains were used for immunoblotting analysis to ascertain the identity of high molecular weight nerve growth factor immunoreactive proteins as prohormones. Both the mouse and human NGF preparations contained 53 and 60 kDa immunoreactive proteins. Of these, the mouse 60 kDa and the human 53 kDa proteins strongly immunoreacted with both prepro-nerve growth factor specific domain antibodies suggesting that they are two NGF prohormone isoforms. In addition, both the mouse and human nerve growth factor preparations contained proteins that were immunoreactive to polyclonal antisera and monoclonal antibodies to mouse 2.5S and/or beta-NGF. High molecular weight aggregates of prohormones were also observed in mouse and human nerve growth factor samples. In summary, none of the ten NGF samples examined were pure as stated. Our study cautions investigators in the field to be aware of the presence of nerve growth factor prohormones and other proteins in various mouse and human nerve growth factors sold commercially.


Subject(s)
Nerve Growth Factors/chemistry , Animals , Blotting, Western , Humans , Isomerism , Luminescent Measurements , Mice , Molecular Weight , Recombinant Proteins/chemistry
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