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3.
Sci Rep ; 11(1): 5980, 2021 03 16.
Article in English | MEDLINE | ID: mdl-33727566

ABSTRACT

Most patients with Whipple's disease have rheumatic symptoms. The aim of our prospective, questionnaire-based, non-interventional clinical study was to assess whether these symptoms are useful in guiding the differential diagnosis to the rheumatic disorders. Forty patients with Whipple's disease, followed by 20 patients for validation and 30 patients with rheumatoid-, 21 with psoriatic-, 15 with palindromic- and 25 with axial spondyloarthritis were recruited for the present investigation. Patients with Whipple's disease and patients with rheumatic disorders were asked to record rheumatic symptoms on pseudonymized questionnaires. The data obtained were subjected to multiple logistic regression analysis. Episodic pain with rapid onset, springing from joint to joint was most common in patients with palindromic arthritis and second most common and somewhat less conspicuous in Whipple's disease. Continuous pain in the same joints predominated in patients with rheumatoid-, psoriatic-, and axial spondyloarthritis. Multiple logistic equations resulted in a predicted probability for the diagnosis of Whipple's disease of 43.4 ± 0.19% (M ± SD) versus a significantly lower probability of 23.8 ± 0.19% (M ± SD) in the aggregate of patients with rheumatic disorders. Mean area under the curve (AUC) ± SD was 0.781 ± 0.044, 95% CI 0.695-0.867, asymptotic significance p < 0.001. The logistic equations predicted probability for the diagnosis of Whipple's disease in the initial series of 40 patients of 43.4 ± 0.19% was not significantly different in the subsequent 20 patients of 38.2 ± 0.28% (M ± SD) (p = 0.376). The data may be useful in a predictive algorithm for diagnosing Whipple's disease. The project is registered as clinical study DRK S0001566.


Subject(s)
Rheumatic Diseases/diagnosis , Whipple Disease/diagnosis , Aged , Analysis of Variance , Anti-Bacterial Agents/therapeutic use , Delayed Diagnosis , Diagnosis, Differential , Disease Management , Disease Susceptibility , Humans , Middle Aged , ROC Curve , Symptom Assessment , Whipple Disease/drug therapy , Whipple Disease/etiology
4.
Emerg Infect Dis ; 27(3): 932-935, 2021 03.
Article in English | MEDLINE | ID: mdl-33622479

ABSTRACT

We examined fecal specimens of patients with diarrhea from 3 continents for Tropheryma whipplei and enteropathogens. T. whipplei was most common in South Africa, followed by Singapore and Germany. Its presence was associated with the presence of other pathogens. An independent causative role in diarrhea appears unlikely.


Subject(s)
Tropheryma , Whipple Disease , Diarrhea , Feces , Germany , Humans , Singapore , South Africa
5.
Dtsch Arztebl Int ; 113(29-30): 503, 2016 07 25.
Article in English | MEDLINE | ID: mdl-27545702
6.
J Immunol ; 190(5): 2354-61, 2013 Mar 01.
Article in English | MEDLINE | ID: mdl-23365082

ABSTRACT

During antimicrobial treatment of classic Whipple's disease (CWD), the chronic systemic infection with Tropheryma whipplei, immune reconstitution inflammatory syndrome (IRIS), is a serious complication. The aim of our study was to characterize the immunological processes underlying IRIS in CWD. Following the definition of IRIS, we describe histological features of IRIS and immunological parameters of 24 CWD IRIS patients, 189 CWD patients without IRIS, and 89 healthy individuals. T cell reconstitution, Th1 reactivity, and the phenotype of T cells were described in the peripheral blood, and infiltration of CD4(+) T cells and regulatory T cells in the duodenal mucosa was determined. During IRIS, tissues were heavily infiltrated by CD3(+), predominantly CD45RO(+)CD4(+) T cells. In the periphery, initial reduction of CD4(+) cell counts and their reconstitution on treatment was more pronounced in CWD patients with IRIS than in those without IRIS. The ratio of activated and regulatory CD4(+) T cells, nonspecific Th1 reactivity, and the proportion of naive among CD4(+) T cells was high, whereas serum IL-10 was low during IRIS. T. whipplei-specific Th1 reactivity remained suppressed before and after emergence of IRIS. The findings that IRIS in CWD mainly are mediated by nonspecific activation of CD4(+) T cells and that it is not sufficiently counterbalanced by regulatory T cells indicate that flare-up of pathogen-specific immunoreactivity is not instrumental in the pathogenesis of IRIS in CWD.


Subject(s)
Immune Reconstitution Inflammatory Syndrome/pathology , Intestinal Mucosa/pathology , T-Lymphocytes, Regulatory/pathology , Th1 Cells/pathology , Tropheryma/immunology , Whipple Disease/pathology , Adult , Aged , Anti-Bacterial Agents/therapeutic use , Biopsy , CD4 Lymphocyte Count , Case-Control Studies , Female , Humans , Immune Reconstitution Inflammatory Syndrome/complications , Immune Reconstitution Inflammatory Syndrome/drug therapy , Immune Reconstitution Inflammatory Syndrome/immunology , Interleukin-10/blood , Interleukin-10/immunology , Intestinal Mucosa/drug effects , Intestinal Mucosa/immunology , Lymphocyte Activation/drug effects , Male , Middle Aged , Retrospective Studies , T-Lymphocytes, Regulatory/drug effects , T-Lymphocytes, Regulatory/immunology , Th1 Cells/drug effects , Th1 Cells/immunology , Tropheryma/drug effects , Whipple Disease/complications , Whipple Disease/drug therapy , Whipple Disease/immunology
7.
J Infect ; 66(3): 263-70, 2013 Mar.
Article in English | MEDLINE | ID: mdl-23291038

ABSTRACT

BACKGROUND: There is no agreement on how and for how long Whipple's disease should be treated. In a randomized trial it was shown that patients can be cured with ceftriaxone or meropenem followed by trimethoprim-sulfamethoxazole for 12 months. The present study tested whether trimethoprim-sulfamethoxazole for three months is sufficient. METHODS: In the time from July 2004 to July 2008, 40 untreated patients from central Europe were sequentially admitted to an open-label, non-randomized extension of the previous trial with essentially an identical protocol. The modified treatment consisted of 2 g ceftriaxone intravenously once daily for 14 days followed by oral trimethoprim-sulfamethoxazole 160/800 mg twice daily for 3 months. Primary endpoint was treatment efficacy compared with the previous study. RESULTS: Twelve months of treatment with trimethoprim-sulfamethoxazole was not more effective than 3 months as indicated by clinical findings, laboratory (p = 0.405, p = 0.631, resp.), and histological data (p = 0.456). 36 of 37 surviving patients including 14 with cerebrospinal infection were in remission without evidence of recurrence after a median follow-up time of 80 months. In one patient, Tropheryma whipplei arthritis recurred 63 months after initial therapy. Secondary endpoints indicate that histology of intestinal biopsies was a more useful indicator to determine eradication of T. whipplei than PCR. In submucosal and extra-intestinal tissue, the diagnostic value of the PCR was superior. Prospective data disclosed a heterogeneous spectrum of clinical presentation and course of Whipple's disease. CONCLUSION: This study indicates that ceftriaxone followed by three months of trimethoprim-sulfamethoxazole is highly efficacious in the treatment of Whipple's disease.


Subject(s)
Anti-Bacterial Agents/therapeutic use , Ceftriaxone/therapeutic use , Trimethoprim, Sulfamethoxazole Drug Combination/therapeutic use , Tropheryma/drug effects , Whipple Disease/drug therapy , Administration, Oral , Aged , Anti-Bacterial Agents/administration & dosage , Anti-Bacterial Agents/adverse effects , Ceftriaxone/administration & dosage , Ceftriaxone/adverse effects , Drug Therapy, Combination , Endoscopy , Female , Humans , Injections, Intravenous , Male , Middle Aged , Treatment Outcome , Trimethoprim, Sulfamethoxazole Drug Combination/administration & dosage , Trimethoprim, Sulfamethoxazole Drug Combination/adverse effects , Whipple Disease/pathology
9.
Ann Intern Med ; 153(11): 710-7, 2010 Dec 07.
Article in English | MEDLINE | ID: mdl-21135294

ABSTRACT

BACKGROUND: Whipple disease, which is caused by infection with Tropheryma whipplei, can be treated effectively with antimicrobials. Occasionally, inflammation reappears after initial improvement; this is often interpreted as refractory or recurrent disease. However, polymerase chain reaction for T. whipplei in tissue is sometimes negative during reinflammation, indicating absence of vital bacteria, and this reinflammation does not respond to antimicrobials but does respond to steroids. OBJECTIVE: To demonstrate that the immune reconstitution inflammatory syndrome (IRIS) occurs in patients treated for Whipple disease. DESIGN: Cohort study. (International Standard Randomised Controlled Trial Number Register registration number: ISRCTN45658456) SETTING: 2 academic medical centers in Germany. METHODS: 142 patients treated for Whipple disease out of a cohort of 187 were observed for reappearance of inflammatory signs after effective antibiotic therapy. Definitions of IRIS in HIV infection, tuberculosis, and leprosy were adapted for application to Whipple disease. RESULTS: On the basis of study definitions, IRIS was diagnosed in 15 of 142 patients. Symptoms included fever, arthritis, pleurisy, erythema nodosum, inflammatory orbitopathy, small-bowel perforation, and a hypothalamic syndrome. Two patients died. There was a positive correlation with previous immunosuppressive treatment and a negative correlation with previous diarrhea and weight loss. LIMITATIONS: The study was observational and thus has inherent weaknesses, such as incomplete and potentially selective data recording. CONCLUSION: The immune reconstitution inflammatory syndrome was diagnosed in about 10% of patients with Whipple disease in the study cohort; the outcome varied from mild to fatal. Patients who had had previous immunosuppressive therapy were at particular risk. An immune reconstitution syndrome should be considered in patients with Whipple disease in whom inflammatory symptoms recur after effective treatment. Early diagnosis and treatment with steroids may be beneficial; prospective studies are needed. PRIMARY FUNDING SOURCE: European Commission and Deutsche Forschungsgemeinschaft.


Subject(s)
Immune Reconstitution Inflammatory Syndrome/etiology , Whipple Disease/immunology , Aged , Anti-Bacterial Agents/therapeutic use , Arthritis/etiology , Central Nervous System Diseases/etiology , Cohort Studies , Female , Fever/etiology , Humans , Immune Reconstitution Inflammatory Syndrome/diagnosis , Immune Reconstitution Inflammatory Syndrome/drug therapy , Intestinal Perforation/etiology , Intestine, Small , Male , Middle Aged , Orbital Diseases/etiology , Prospective Studies , Recurrence , Risk Factors , Skin Diseases/etiology , Whipple Disease/drug therapy
10.
Gastroenterology ; 138(2): 478-86; quiz 11-2, 2010 Feb.
Article in English | MEDLINE | ID: mdl-19879276

ABSTRACT

BACKGROUND & AIMS: Whipple's disease is a chronic infection caused by the actinomycete Tropheryma whipplei. We conducted a randomized controlled trial of the efficacy of antimicrobials that are able to cross the blood-brain barrier and to which T whipplei is susceptible. METHODS: Patients from central Europe with previously untreated Whipple's disease (n = 40) were assigned randomly to groups given daily infusions of either ceftriaxone (1 x 2 g, 20 patients) or meropenem (3 x 1 g, 20 patients) for 14 days, followed by oral trimethoprim-sulfamethoxazole for 12 months. The primary outcome measured was maintenance of remission for 3 years, determined by a composite index of clinical and laboratory data as well as histology. RESULTS: All patients were observed for the entire follow-up period (median, 89 mo; range, 71-128 mo); all achieved clinical and laboratory remission. Remission was maintained in all patients during the time of observation, except for 2 who died from unrelated causes. A single patient with asymptomatic cerebrospinal infection who was resistant to both treatments responded to chloroquine and minocycline. The odds ratio for the end point (remission for at least 3 years) was 0.95 (95% confidence interval, 0.05-16.29; P = 1.0). CONCLUSIONS: This was a randomized controlled trial to show that treatment with ceftriaxone or meropenem, followed by trimethoprim-sulfamethoxazole, cures patients with Whipple's disease. One asymptomatic individual with infection of the cerebrospinal fluid required additional therapy.


Subject(s)
Anti-Bacterial Agents/therapeutic use , Ceftriaxone/therapeutic use , Thienamycins/therapeutic use , Trimethoprim, Sulfamethoxazole Drug Combination/therapeutic use , Whipple Disease/drug therapy , Administration, Oral , Adult , Aged , Aged, 80 and over , Anti-Bacterial Agents/administration & dosage , Biopsy , Ceftriaxone/administration & dosage , Drug Therapy, Combination , Female , Humans , Injections, Intravenous , Intestinal Mucosa/microbiology , Intestinal Mucosa/pathology , Male , Meropenem , Middle Aged , Remission Induction , Thienamycins/administration & dosage , Treatment Outcome , Trimethoprim, Sulfamethoxazole Drug Combination/administration & dosage , Tropheryma , Whipple Disease/pathology
11.
Gastroenterology ; 136(7): 2289-94, 2009 Jun.
Article in English | MEDLINE | ID: mdl-19208355

ABSTRACT

BACKGROUND & AIMS: Whipple's disease is a systemic, chronic, relapsing disorder caused by a combination of environmental (Tropheryma whipplei) and unknown host factors. Because it is a rare disease, the association between HLA type and Whipple's disease has been studied in only small numbers of patients; these studies have led to conflicting results. We aimed to investigate whether disease phenotype and outcome are associated with HLA type in 122 patients with Whipple's disease. METHODS: Genomic DNA was collected from 103 German, 11 Italian, and 8 Austrian patients with Whipple's disease, along with 62 healthy Austrian workers exposed to T whipplei (14 stool samples contained the bacterium). HLA class I and II alleles were identified by polymerase chain reaction analysis. Patient genotypes were compared with those of healthy German and Austrian populations; data for Italian controls were obtained from the Pavia HLA bone marrow donors' bank. RESULTS: HLA-DRB1*13 and DQB1*06 alleles occurred significantly more frequently in patients with Whipple's disease but not in healthy individuals who had been exposed to T Whipplei. The cumulative odds ratios for disease were 2.23 for the DRB1*13 allele (P < .0001) and 2.25 for the DQB1*06 allele (P < .0001). CONCLUSIONS: DRB1*13 and DQB1*06 alleles were found to be risk factors in the largest HLA study ever performed in patients with Whipple's disease.


Subject(s)
Alleles , Gene Frequency , HLA-DQ Antigens/genetics , HLA-DR Antigens/genetics , Whipple Disease/genetics , Austria , Case-Control Studies , Confidence Intervals , Female , Genetic Markers/genetics , Genetic Predisposition to Disease , Genotype , Germany , HLA-DQ Antigens/metabolism , HLA-DR Antigens/metabolism , HLA-DRB1 Chains , Humans , Italy , Male , Odds Ratio , Polymerase Chain Reaction , Probability , Reference Values , Risk Factors , Sensitivity and Specificity , Tropheryma/isolation & purification , Whipple Disease/diagnosis
12.
Microbiology (Reading) ; 154(Pt 2): 521-527, 2008 Feb.
Article in English | MEDLINE | ID: mdl-18227256

ABSTRACT

Tropheryma whipplei, the causative agent of Whipple's disease, is associated with various clinical manifestations as well as an asymptomatic carrier status, and it exhibits genetic heterogeneity. However, relationships that may exist between environmental and clinical strains are unknown. Herein, we developed an efficient genotyping system based on four highly variable genomic sequences (HVGSs) selected on the basis of genome comparison. We analysed 39 samples from 39 patients with Whipple's disease and 10 samples from 10 asymptomatic carriers. Twenty-six classic gastrointestinal Whipple's disease associated with additional manifestations, six relapses of classic Whipple's disease (three gastrointestinal and three neurological relapses), and seven isolated infections due to T. whipplei without digestive involvement (five endocarditis, one spondylodiscitis and one neurological infection) were included in the study. We identified 24 HVGS genotypes among 39 T. whipplei DNA samples from the patients and 10 T. whipplei DNA samples from the asymptomatic carriers. No significant correlation between HVGS genotypes and clinical manifestations of Whipple's disease, or asymptomatic carriers, was found for the 49 samples tested. Our observations revealed a high genetic diversity of T. whipplei strains that is apparently independent of geographical distribution and unrelated to bacterial pathogenicity. Genotyping in Whipple's disease may, however, be useful in epidemiological studies.


Subject(s)
Polymorphism, Genetic , Tropheryma/classification , Tropheryma/genetics , Whipple Disease/microbiology , DNA, Bacterial/classification , DNA, Bacterial/genetics , DNA, Ribosomal Spacer/genetics , Genotype , Humans , Molecular Sequence Data , Phylogeny , Polymerase Chain Reaction/methods , RNA, Bacterial/genetics , RNA, Ribosomal, 16S/genetics , RNA, Ribosomal, 23S/genetics , Sequence Analysis
13.
Wien Klin Wochenschr ; 119(21-22): 633-8, 2007.
Article in English | MEDLINE | ID: mdl-18043883

ABSTRACT

BACKGROUND AND OBJECTIVE: Abdominal pain is generally believed to be a symptom of intra-abdominal disease. When no pathological findings are evident, abdominal pain is considered functional. Abdominal pain, however, may also originate in the abdominal wall. METHODS: Consecutive patients with unexplained abdominal pain were enrolled in a prospective observational study in a gastroenterologic clinic during a period of three years. The following criteria were tested: Can abdominal pain be elicited by physical movement? Is the source of pain localized to a circumscribed site in the abdominal wall? Can pain be provoked by digital palpation in this area and does pain increase when the abdominal muscles are tensed? RESULTS: Clinical examination of 55 patients revealed small painful pits in the abdominal wall with varying intensity of pain when the abdominal muscles were contracted: in 39 patients the painful area was located in the semilunar line, in seven patients the pain originated in the linea alba between xiphoid and umbilicus, in five cases the painful spots were situated within the rectus muscle, and in four patients the pain was localized along the costal arch. Of the 39 patients with pain in the semilunar line, 16 had a BMI > 30, 12 presented with anxiety and depression, and 10 reported bloating and straining during defecation. Pain in the rectus muscle was associated with exercise. The patients with pain in the linea alba and at the costal arch suffered from obesity, anxiety or depression. CONCLUSIONS: These findings suggest that repeated forceful contractions of the abdominal wall muscles during exercise and straining, as well as chronic inflation of the abdominal wall by fat pads and by bloating, may cause strain and pain in the abdominal wall at sites predestined by anatomy. Symptom-specific anxiety may be a consequence of chronic unexplained abdominal pain. A novel classification of abdominal wall pain is proposed. The correct diagnosis will avoid repeated and costly investigations and relieve the patient's anxiety.


Subject(s)
Abdominal Pain/diagnosis , Abdominal Wall , Pain Measurement/methods , Physical Examination/methods , Adult , Aged , Female , Humans , Middle Aged , Reproducibility of Results , Sensitivity and Specificity
14.
Haematologica ; 92(9): 1264-5, 2007 Sep.
Article in English | MEDLINE | ID: mdl-17768122

ABSTRACT

Codon 104(-G), a heterozygous frameshift mutation in exon 2 of HBB, resulted in a dominantly inherited beta0-phenotype with mild anemia in a German kindred, and thalassemia intermedia in the index patient. A co-inherited a gene triplication, long-term transfusion therapy, and ineffective erythropoiesis were confounding factors.


Subject(s)
Anemia, Hemolytic/genetics , Codon , Frameshift Mutation/genetics , Globins/genetics , beta-Thalassemia/genetics , Adult , Aged , Aged, 80 and over , Blood Transfusion , Erythropoiesis , Female , Genes, Dominant , Germany , Hepatomegaly/etiology , Heterozygote , Humans , Iron Overload , Male , Pedigree , Phenotype , Splenomegaly/etiology , White People , beta-Thalassemia/diagnosis , beta-Thalassemia/therapy
15.
J Immunol ; 177(3): 2015-22, 2006 Aug 01.
Article in English | MEDLINE | ID: mdl-16849516

ABSTRACT

Whipple's disease is a rare infectious disorder caused by Tropheryma whipplei. Major symptoms are arthropathy, weight loss, and diarrhea, but the CNS and other organs may be affected, too. The incidence of Whipple's disease is very low despite the ubiquitous presence of T. whipplei in the environment. Therefore, it has been suggested that host factors indicated by immune deficiencies are responsible for the development of Whipple's disease. However, T. whipplei-specific T cell responses could not be studied until now, because cultivation of the bacteria was established only recently. Thus, the availability of T. whipplei Twist-Marseille(T) has enabled the first analysis of T. whipplei-specific reactivity of CD4(+) T cells. A robust T. whipplei-specific CD4(+) Th1 reactivity and activation (expression of CD154) was detected in peripheral and duodenal lymphocytes of all healthy (16 young, 27 age-matched, 11 triathletes) and disease controls (17 patients with tuberculosis) tested. However, 32 Whipple's disease patients showed reduced or absent T. whipplei-specific Th1 responses, whereas their capacity to react to other common Ags like tetanus toxoid, tuberculin, actinomycetes, Giardia lamblia, or CMV was not reduced compared with controls. Hence, we conclude that an insufficient T. whipplei-specific Th1 response may be responsible for an impaired immunological clearance of T. whipplei in Whipple's disease patients and may contribute to the fatal natural course of the disease.


Subject(s)
Actinomycetales/immunology , Down-Regulation/immunology , Intestinal Mucosa/immunology , Intestinal Mucosa/metabolism , Th1 Cells/immunology , Th1 Cells/metabolism , Whipple Disease/immunology , Adult , Aged , Aged, 80 and over , Antigens, Bacterial/immunology , Antigens, Viral/immunology , CD4-Positive T-Lymphocytes/immunology , CD4-Positive T-Lymphocytes/microbiology , CD4-Positive T-Lymphocytes/virology , Cell Line , Cell Separation , Cells, Cultured , Duodenum/cytology , Duodenum/immunology , Duodenum/metabolism , Duodenum/microbiology , Enterotoxins/immunology , Epitopes, T-Lymphocyte/immunology , Female , Humans , Interleukin-2/pharmacology , Intestinal Mucosa/microbiology , Lymphocyte Activation/immunology , Male , Middle Aged , Staphylococcus aureus/immunology , Th1 Cells/microbiology , Whipple Disease/microbiology , Whipple Disease/virology
16.
Regul Pept ; 111(1-3): 153-9, 2003 Mar 28.
Article in English | MEDLINE | ID: mdl-12609763

ABSTRACT

UNLABELLED: Xenin is a 25 amino acid peptide produced by specific endocrine cells of the duodenal mucosa. Xenin has multiple biological actions in the gastrointestinal tract. It modulates intestinal motility, affects exocrine pancreatic secretion, and gastric secretion of acid. In the present investigation, we studied plasma concentration of xenin in volunteers after modified sham feeding and after meals of different composition. Plasma xenin concentrations were determined by radioimmunoassay in unextracted plasmas and after acidic extraction using C-18 Sep-Pak chromatography and after neutral extraction using affinity filtration. Both extraction methods were followed by C 18 r.p. HPLC chromatography. Xenin plasma concentrations in unextracted and in extracted plasma rose significantly after modified sham feeding when the food was brought to the volunteers from another room immediately before sham feeding started. When the volunteers had the opportunity to observe the preparation of the meal, xenin plasma concentrations during fasting were high and no further rise was observed after sham feeding. Isocaloric feeding resulted in elevated xenin concentrations in unextracted plasma and after high-pressure liquid chromatography. The methods of extraction, acidic or neutral, did not affect the results. CONCLUSION: Cephalic factors, investigated by modified sham feeding, stimulate release of xenin into the circulation. Xenin may participate in the central nervous regulation of gastrointestinal function.


Subject(s)
Eating/physiology , Peptides/blood , Adult , Chromatography, High Pressure Liquid/methods , Energy Intake/physiology , Gastrointestinal Hormones/blood , Humans , Male , Neurotensin , Radioimmunoassay , Time Factors
17.
Gastroenterology ; 123(5): 1616-26, 2002 Nov.
Article in English | MEDLINE | ID: mdl-12404236

ABSTRACT

BACKGROUND & AIMS: Xenin is a 25-amino acid peptide produced by specific endocrine cells of the duodenal mucosa. We investigated whether xenin is expressed in neuroendocrine tumors. METHODS: Seventy-two foregut and midgut neuroendocrine tumors were examined by means of immunohistochemistry, confocal laser microscopy with an antibody against the C-terminus of xenin, and high-pressure liquid chromatography after acidic extraction, assessed by radioimmunoassay. RESULTS: We found xenin-immunoreactive cells in 23 of 26 duodenal neuroendocrine tumors, including gastrinomas, somatostatinomas, and nonfunctioning and enterochromaffin cell tumors. In these tumors, up to 20% of the endocrine cells were xenin immunoreactive, and xenin immunoreactivity was concentrated in secretory granules. Xenin was coexpressed with chromogranin A. We found no xenin expression in gastrin-, somatostatin-, and serotonin-immunoreactive cells. High-pressure liquid chromatography after acidic extraction revealed 497 +/- 285 pmol of xenin per gram of tissue in 5 duodenal gastrinomas. The other neuroendocrine tumors, such as bronchial carcinoids, gastric enterochromaffin-like cell carcinoids, gastric and ileal enterochromaffin cell carcinoids, insulinomas, and gastrinomas of pancreatic origin, did not contain immunoreactive xenin. CONCLUSIONS: Xenin is a peptide marker specific to neuroendocrine tumors of the duodenum. This finding may be useful in tumor classification and in the differential diagnosis of neuroendocrine tumors of the upper gut.


Subject(s)
Duodenal Neoplasms/metabolism , Neuroendocrine Tumors/metabolism , Peptides/metabolism , Chromatography, High Pressure Liquid , Gastrinoma/metabolism , Humans , Immunohistochemistry , Neurotensin , Peptides/isolation & purification , Somatostatinoma/metabolism
18.
Peptides ; 23(8): 1519-25, 2002 Aug.
Article in English | MEDLINE | ID: mdl-12182956

ABSTRACT

Xenin, a 25 amino acid peptide, interacts with the neurotensin receptor subtype 1 of intestinal muscles of the guinea pig. Replacement of the C-terminal Lys-Arg peptide bond in xenin 6 by a reduced pseudo-peptide bond augmented binding affinity to isolated jejunal and colonic muscle membranes by factors of 7.7 and 21.0 respectively; the potency to contract the jejunum and to relax the colon was increased by factors of 3.2 and 1.3. The C-terminus Trp-Ile-Leu (WIL) of xenin, in contrast to the C-terminus Tyr-Ile-Leu (YIL) of neurotensin, bound competitively to the muscle membranes. WIL blocked the contractile action of xenin in the jejunum and was synergistic with the relaxing action in the colon. The Lys-Arg motif and Trp in the C-terminus of xenin are essential structures in the action of xenin on the enteral smooth muscle receptors.


Subject(s)
Intestinal Mucosa/metabolism , Muscle, Smooth/metabolism , Peptides/metabolism , Receptors, Neurotensin/metabolism , Animals , Gastrointestinal Hormones/metabolism , Gastrointestinal Hormones/pharmacology , Guinea Pigs , Intestines/drug effects , Kinetics , Muscle Contraction/drug effects , Muscle Contraction/physiology , Muscle, Smooth/drug effects , Neurotensin , Peptides/pharmacology
19.
Peptides ; 23(3): 523-9, 2002 Mar.
Article in English | MEDLINE | ID: mdl-11836002

ABSTRACT

Xenin, a 25 aminoacid peptide, interacts with the neurotensin receptor subtype 1 of intestinal muscles of the guinea pig. Replacement of the C-terminal Lys -Arg peptide bond in xenin 6 by a reduced pseudo-peptide bond augmented binding affinity to isolated jejunal and colonic muscle membranes by factors of 7.7 and 21.0 respectively; the potency to contract the jejunum and to relax the colon was increased by factors of 3.2 and 1.3. The C-terminus Trp-Ile-Leu (WIL) of xenin, in contrast to the C-terminus Tyr-Ile-Leu (YIL) of neurotensin, bound competitively to the muscle membranes. WIL blocked the contractile action of xenin in the jejunum and was synergistic with the relaxing action in the colon. The Lys -Arg motif and Trp in the C-terminus of xenin are essential structures in the action of xenin on the enteral smooth muscle receptors.


Subject(s)
Muscle Contraction/drug effects , Muscle, Smooth/drug effects , Peptides/pharmacology , Receptors, Neurotensin/metabolism , Amino Acid Sequence , Animals , Binding, Competitive , Guinea Pigs , In Vitro Techniques , Molecular Sequence Data , Muscle, Smooth/metabolism , Muscle, Smooth/physiology , Neurotensin
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