Structured terminology for capsule endoscopy: results of retrospective testing and validation in 766 small-bowel investigations

BACKGROUND AND STUDY AIMS

Capsule endoscopy (CE) is an effective means of investigating the small bowel in patients with gastrointestinal diseases. Computerized reports are frequently used in endoscopy, and the Minimal Standard Terminology (MST) has been promoted by endoscopy societies as the official vocabulary for endoscopy. The aims of this study were to design a lexicon for CE reports based on the principles of the MST and to validate lists of terms for describing findings and reasons for performing a CE by cross-matching them with the results of CE procedures collected during ongoing clinical studies.

MATERIALS AND METHODS

A consensus-based Capsule Endoscopy Structured Terminology (CEST) was developed by experts involved in CE studies. Lists of terms suitable for CE were designed for the various sections of an endoscopic report. They were then correlated with the corresponding MST lists for duodenal and intestinal endoscopy. The results of 766 CE procedures, collected in an electronic case record form (eCRF), were analyzed to provide lists of reasons for performing the procedures and of the findings. The eCRF provided only a limited number of items for each data field, along with free-text facilities. Only descriptions pertaining to the small bowel were analyzed. Lists of terms were then reviewed by two experts to group obvious synonyms. The accuracy of the CEST was defined beforehand as the capability to describe 90 % of entries.

RESULTS

A total of 766 CE procedures were analyzed. The eCRF included 824 entries as reasons for the examination in 655 CEs (1.3 per procedure). These represented 122 different expressions. After grouping of synonyms, 28 expressions remained. Among them, 10 were matched with terms from the list of reasons for performing CE offered in the CEST. These were the most frequently used, accounting for 768 entries in this field (93.2 %). All eCRFs contained at least one description of findings. A total of 109 CE procedures were classified as normal (14.3 %). A total of 2624 entries for abnormal findings were recorded for 657 procedures (4.0 per procedure). In all, 213 different expressions were used to describe abnormal findings. After grouping of synonyms, 52 expressions remained. Among these, 27 were matched with terms from the list of findings in the CEST, covering 2403 entries (91.6 %).

CONCLUSIONS

In this study, CEST terms were capable of describing more than 90 % of the reasons for performance and of the findings in an unselected set of CE procedures. CEST is therefore suitable for use as the standard lexicon for CE reports. Adopted as a standard, it could significantly improve the quality of the data collected and reported in CE studies.

Pulmonary Mycobacterium bovis infection in a dog

AIM

To describe the clinical course of a dog infected with Mycobacterium bovis causing a granulomatous pneumonia.

CLINICAL FINDINGS

The dog initially presented with a persistent cough, inappetence and weight loss. Clinical findings included a fever, dyspnoea and tachypnoea, with haematological evidence of a mild neutrophilia and hypoalbuminaemia. Radiographs of the chest demonstrated a concomitant pneumothorax, pleural effusion, and a consolidated area within the left caudal lung lobe. An exploratory thoracotomy revealed this to be a ruptured granulomatous lesion. Subsequent histopathological, microbiological and genetic studies identified M. bovis as the causal agent.

CLINICAL SIGNIFICANCE

Mycobacterium bovis infections should be included in the differential diagnosis of pulmonary disease and pleural effusions in dogs living in regions of New Zealand known to have a high incidence of mycobacterial infection in wildlife and farm animals.

Clinical evaluation of the use of the M2A patency capsule system before a capsule endoscopy procedure, in patients with known or suspected intestinal stenosis

BACKGROUND AND STUDY AIM

The main complication of video capsule endoscopy (VCE) is the blocking of the capsule by a gastrointestinal stenosis. The "patency capsule" is a self-dissolving capsule that is the same size as the video capsule. It contains a radiofrequency identification (RFID) tag that allows it to be detected by a scanning device placed on the abdominal wall. When its passage is blocked by a stenosis, the patency capsule dissolves in 40-80 hours after ingestion. The aim of this study was to evaluate the usefulness of this system in patients with suspected intestinal stenosis but also requiring VCE.

PATIENTS AND METHODS

22 patients (16 men; 46 +/- 18 years; 15 with diagnosed or suspected Crohn's disease, two with suspected intestinal tumor, and two on nonsteroidal anti-inflammatory drugs) were first investigated with an abdominal CT plus enteroclysis (entero-CT, n = 15) or a small-bowel follow-through (SBFT, n = 7). The patency capsule was then administered at around 09.00 to fasting patients. The presence of the patency capsule in the digestive tract was assessed 30 hours later using the hand-held scanner. When the patency capsule was detected, a plain abdominal film was obtained, and this was repeated every 24 hours until capsule expulsion.

RESULTS

At 30 hours after ingestion, the patency capsule was detected in 17 patients (72.3 %): in the area of the small intestine (n = 6) and in the colon (n = 11). In all the patients in whom the capsule was blocked in the small intestine, the stenosis had been suspected on CT or SBFT. In three patients, the delay in progression of the patency capsule led to cancellation of the VCE procedure. In three patients, the patency capsule induced a symptomatic intestinal occlusion, which resolved spontaneously in one and required emergency surgery in two. Although these two patients would have been obliged to undergo operation for their primary disease in any case, the procedure had to be brought forward. In one patient, the capsule passed through the stenosis without symptoms. All patients in whom the progression of the patency capsule was delayed had an established or suspected diagnosis of Crohn's disease.

CONCLUSIONS

The current technical development of the patency capsule limits its use in clinical practice, as it did not detect stenoses undiagnosed by CT or SBFT. The start of dissolution at 40 hours after ingestion is too slow to prevent episodes of intestinal occlusion. Patients with Crohn's disease are most likely to be at risk of blockage of progression of the capsule and should benefit from a CT investigation before VCE. However, a careful interview eliciting the patient's medical history and symptoms remains the most useful indicator with regard to suspicion of an intestinal stenosis.

Clinical evaluation of the use of the M2A patency capsule system before a capsule endoscopy procedure, in patients with known or suspected intestinal stenosis

BACKGROUND AND STUDY AIM

The main complication of video capsule endoscopy (VCE) is the blocking of the capsule by a gastrointestinal stenosis. The "patency capsule" is a self-dissolving capsule that is the same size as the video capsule. It contains a radiofrequency identification (RFID) tag that allows it to be detected by a scanning device placed on the abdominal wall. When its passage is blocked by a stenosis, the patency capsule dissolves in 40-80 hours after ingestion. The aim of this study was to evaluate the usefulness of this system in patients with suspected intestinal stenosis but also requiring VCE.

PATIENTS AND METHODS

22 patients (16 men; 46 +/- 18 years; 15 with diagnosed or suspected Crohn's disease, two with suspected intestinal tumor, and two on nonsteroidal anti-inflammatory drugs) were first investigated with an abdominal CT plus enteroclysis (entero-CT, n = 15) or a small-bowel follow-through (SBFT, n = 7). The patency capsule was then administered at around 09.00 to fasting patients. The presence of the patency capsule in the digestive tract was assessed 30 hours later using the hand-held scanner. When the patency capsule was detected, a plain abdominal film was obtained, and this was repeated every 24 hours until capsule expulsion.

RESULTS

At 30 hours after ingestion, the patency capsule was detected in 17 patients (72.3 %): in the area of the small intestine (n = 6) and in the colon (n = 11). In all the patients in whom the capsule was blocked in the small intestine, the stenosis had been suspected on CT or SBFT. In three patients, the delay in progression of the patency capsule led to cancellation of the VCE procedure. In three patients, the patency capsule induced a symptomatic intestinal occlusion, which resolved spontaneously in one and required emergency surgery in two. Although these two patients would have been obliged to undergo operation for their primary disease in any case, the procedure had to be brought forward. In one patient, the capsule passed through the stenosis without symptoms. All patients in whom the progression of the patency capsule was delayed had an established or suspected diagnosis of Crohn's disease.

CONCLUSIONS

The current technical development of the patency capsule limits its use in clinical practice, as it did not detect stenoses undiagnosed by CT or SBFT. The start of dissolution at 40 hours after ingestion is too slow to prevent episodes of intestinal occlusion. Patients with Crohn's disease are most likely to be at risk of blockage of progression of the capsule and should benefit from a CT investigation before VCE. However, a careful interview eliciting the patient's medical history and symptoms remains the most useful indicator with regard to suspicion of an intestinal stenosis.

Clinical impact of capsule endoscopy compared to push enteroscopy: 1-year follow-up study

BACKGROUND AND STUDY AIMS

The long-term outcome for patients with obscure bleeding after capsule endoscopy (CE) is still unclear. In this study, the clinical outcome was used as the gold standard to determine the sensitivity and specificity of CE and push enteroscopy (PE) in the diagnosis of small-bowel lesions in patients with obscure bleeding.

PATIENTS AND METHODS

Fifty-eight patients from a previous prospective study (comparing PE and CE) were included; the patients were contacted after 1 year. The final diagnosis, bleeding status, new gastrointestinal examinations, and treatments performed were recorded. On the basis of these data, each case was classified into true/false positive or true/false negative findings at PE and CE. The results were compared with the initial classification of lesions observed at CE: highly relevant (P2) and less relevant (P0, P1) lesions.

RESULTS

Follow-up data were available for 56 patients. According to the defined true/false positive and negative cases, the sensitivity and specificity values for CE and PE were 92 % and 48 %, and 80 % and 69 %, respectively ( P < 0.01 for the difference between CE and PE). Highly relevant (P2) lesions observed at CE were more frequently classified into true-positive cases (15 of 18 versus seven of 22; P < 0.01) and led more frequently to therapeutic decisions (11 of 18 versus five of 22; P = 0.02) in comparison with less relevant lesions (P0, P1).

CONCLUSIONS

CE is a highly sensitive examination for the detection of small-bowel lesions in patients with obscure gastrointestinal bleeding, with a specificity lower than that of PE when the clinical outcome is used as the gold standard.

Temporary intestinal occlusion induced by a "patency capsule" in a patient with Crohn's disease

A 26-year-old woman was admitted for the investigation of abdominal symptoms related to ileal Crohn's disease. The patient had been diagnosed 3 years previously with systemic sclerosis, and had been experiencing digestive complaints for 6 months. A first computed tomography (CT) scan showed ileal intestinal mucosal alterations, associated with a sclerolipomatosis and suspicion of ileal stenosis. An ileocolonoscopy was then performed and showed ulcers in the terminal ileum with nonspecific inflammatory changes found on biopsies, both suggesting the diagnosis of Crohn's disease. The patient was admitted for M2A capsule endoscopy, in order to clarify the respective roles of systemic sclerosis and Crohn's disease with regard to the symptoms and secondarily to determine the anatomical extent of the Crohn's lesions. A patency capsule was administered, for detection of intestinal stenosis before capsule endoscopy was done. At 30 hours after capsule ingestion, the patient complained of abdominal pain and nausea and experienced intestinal obstruction due to the blockage of the patency capsule in the ileal stenosis. The capsule dissolved after 76 hours and the patient then improved. After a few days, the patient underwent ileocecal resection. Pathological examination of the surgical specimen confirmed the presence of an ileal stenosis 17 cm in length. In some circumstances a patency capsule may dissolve slowly, leading to transitory intestinal obstruction requiring medical intervention. It should thus be used cautiously under clinical surveillance in patients with Crohn's disease.

Clinical usefulness of the endoscopic video capsule as the initial intestinal investigation in patients with obscure digestive bleeding: validation of a diagnostic strategy based on the patient outcome after 12 months

BACKGROUND AND STUDY AIMS

In patients with obscure digestive bleeding, the bleeding source is frequently located in the small bowel. Capsule endoscopy (CE) is an effective method of investigating the whole small bowel in such patients. In the present study, a diagnostic approach was tested in patients with obscure digestive bleeding in which CE was included as the initial examination of the small bowel when the esophagogastroduodenoscopy (EGD) and colonoscopy findings were normal.

PATIENTS AND METHODS

Patients admitted between October 2000 and February 2002 for obscure digestive bleeding underwent CE as the initial intestinal investigation, and the further management was decided on the basis of the results. After 12 months, follow-up data were obtained from all patients and referring physicians. The positive predictive value was calculated as the percentage of patients in whom CE detected a relevant lesion, and the negative predictive value as the percentage of patients with normal CE in whom no intestinal lesion was detected during the follow-up period.

RESULTS

Forty-four patients (21 men, 23 women, aged 63 +/- 17 y) were included in the study. Twenty-two had overt bleeding and 22 had occult bleeding. CE detected an intestinal lesion in 18 patients (41.9 %)-- nine with angiomas, five with ulcers, one with a tumor, two with portal hypertension, and one with ischemic ileitis. The findings were normal in 17 patients (39.5 %). CE detected upper gastrointestinal lesions missed at EGD in four patients and blood in the stomach in two patients or in the proximal colon in three, leading to new endoscopies. Intestinal lesions detected at CE were treated as follows: push enteroscopy with treatment in eight patients, surgery in four, and medical treatment in six. In eight patients who underwent push enteroscopy, the procedure did not reveal lesions missed by CE. After 1 year, 15 of the 18 patients treated for intestinal lesions had no further bleeding and no anemia; one died after surgery (for resection of an ischemic intestinal loop), one relapsed, and one was diagnosed with a different intestinal condition. In all patients with extraintestinal lesions or blood detected at CE, further endoscopies led to diagnosis and therapy, with a favorable outcome. In patients with normal CE, no intestinal lesion was detected, but an extraintestinal source of bleeding was diagnosed and treated in nine patients (in the upper gastrointestinal tract in five cases and in the colon in four). Three patients had anemia of hematological origin and four had inadequate iron intake. The positive predictive value of CE was 94.4 % in patients with intestinal lesions, and the negative predictive value was 100 % in patients with normal CE findings.

CONCLUSIONS

In patients with obscure digestive bleeding, CE positively predicted the intestinal diagnosis or normal status in 95.5 % of cases. A diagnostic approach to obscure digestive bleeding that includes CE after the initial endoscopic work-up thus appears to be a valid strategy for small-bowel examinations.

Genetic variability and taxonomic position of ectomycorrhizal fungus Pisolithus from India

Eight ectomycorrhizal fungal isolates of Pisolithus associated with Eucalyptus species in different parts of India were collected and the genetic variability of these isolates was studied by ITS-RFLP and ITS sequencing. All the isolates showed same RFLP patterns with each restriction enzyme, indicating all these isolates of Pisolithus are of the same genotype. The sequence comparison of KN6 of Indian isolate showed high sequence similarities with the isolates of Pisolithus associated with Eucalyptus from Australia. Phylogeny analysis showed that all the isolates compared in this study clustered into four main groups The Indian isolate (KN6) clustered with Pisolithus albus isolates of group I, which are associated with Eucalyptus. These results suggested that Pisolithus isolates found in India are P. albus.

The role of video capsule endoscopy in the diagnosis of digestive diseases: a review of current possibilities

Video capsule endoscopy represents a significant advance in the investigation of intestinal diseases. The performance of the procedure and indications are reviewed here in order to establish guidelines for its use, in accordance with current knowledge from the published literature. Capsule endoscopy is performed in patients who have fasted for 12 h, but who are allowed to drink 2 h after and to eat 4 h after ingesting the capsule. Software features highlighting suspected blood and allowing simultaneous viewing of two images reduce the time required to review the findings, as well as improving the diagnostic yield. Pacemakers and other electrical medical devices are no longer a contraindication to the procedure. Indications that have been validated include obscure digestive bleeding, intestinal lesions related to nonsteroidal anti-inflammatory drugs, and familial polyposis. Capsule endoscopy frequently detects intestinal lesions in patients with Crohn's disease and could become the first-choice examination in patients with suspected Crohn's disease after conventional endoscopic investigations. Other indications currently under evaluation include celiac disease, pediatric indications, and examination of other parts of the gastrointestinal tract.

The nature of alkanethiol self-assembled monolayer adsorption on sputtered gold substrates

A detailed study of the self-assembly and coverage by 1-nonanethiol of sputtered Au surfaces using molecular resolution atomic force microscopy (AFM) and scanning tunneling microscopy (STM) is presented. The monolayer self-assembles on a smooth Au surface composed predominantly of [111] oriented grains. The domains of the alkanethiol monolayer are observed with sizes typically of 5-25 nm, and multiple molecular domains can exist within one Au grain. STM imaging shows that the (4 x 2) superlattice structure is observed as a (3 x 2) structure when imaged under noncontact AFM conditions. The 1-nonanethiol molecules reside in the threefold hollow sites of the Au[111] lattice and aligned along its [112] lattice vectors. The self-assembled monolayer (SAM) contains many nonuniformities such as pinholes, domain boundaries, and monatomic depressions which are present in the Au surface prior to SAM adsorption. The detailed observations demonstrate limitations to the application of 1-nonanethiol as a resist in atomic nanolithography experiments to feature sizes of approximately 20 nm.

Hebeloma cylindrosporum- a model species to study ectomycorrhizal symbiosis from gene to ecosystem

The basidiomycete Hebeloma cylindrosporum has been extensively studied with respect to mycorrhiza differentiation and metabolism and also to population dynamics. Its life cycle can be reproduced in vitro and it can be genetically transformed. Combined biochemical, cytological, genetical and molecular approaches led to the characterisation of mutant strains affected in mycorrhiza formation. These studies demonstrated the role of fungal auxin as a signal molecule in mycorrhiza formation and should allow the characterisation of essential fungal genes necessary to achieve a compatible symbiotic interaction. Random sequencing of cDNAs has identified numerous key functional genes which allowed dissection of essential nitrogen assimilation pathways. H. cylindrosporum also proved to be a remarkable model species to uncover the dynamics of natural populations of ectomycorrhizal fungi and the way in which they respond and adapt to anthropogenic disturbance of the forest ecosystem. Although studies on mycorrhiza differentiation and functioning and those on the population dynamics of H. cylindrosporum have been carried out independently, they are likely to converge in a renewed molecular ecophysiology which will envisage how ectomycorrhizal symbiosis functions under varying field conditions. Contents Summary 481 I. Introduction 482 II. Taxonomy, distribution, autecology, and host range of H. cylindrosporum 482 III. The Hebeloma cylindrosporum toolbox 483 IV. Mycorrhiza differentiation 486 V. Nutritional interactions 488 VI. Genetic diversity and dynamics of H. cylindrosporum populations in P. pinaster forest ecosystems 491 VII. Future directions 494 Acknowledgements 494 References 494.

Diagnostic value of endoscopic capsule in patients with obscure digestive bleeding: blinded comparison with video push-enteroscopy

BACKGROUND AND STUDY AIMS

This study was designed to prospectively compare the diagnostic yield of the M2A endoscopic capsule with that of video push-enteroscopy in exploring the small intestine in patients with obscure digestive bleeding.

PATIENTS AND METHODS

Patients with either occult or overt obscure digestive bleeding and a negative endoscopic work-up underwent a double intestinal investigation, with video push-enteroscopy and a wireless capsule, performed blindly by separate examiners. The diagnostic yield for each technique was defined as the frequency of detection of clinically relevant intestinal lesions, i. e. those having the potential for bleeding.

RESULTS

60 patients (27 men, 33 women; age 58 +/- 18 years; hemoglobin 9.4 +/- 2.5 g/dl) were included, 32 with occult and 28 with overt bleeding. Results were analyzed for 58 patients, who completed both examinations. Lesions were detected in 43 patients: with both techniques in 19, only by capsule in 21, and, conversely, only by push-enteroscopy in 3 ( P = 0.04). Final diagnoses were as follows: a P2 lesion with high bleeding potential in 28 patients (19 angiomata, 6 ulcerations, 2 tumors, 1 case of intestinal varices); a P1 lesion with intermediate bleeding potential in 15 patients (2 patients with mucosal erosions, 13 patients with mucosal red spots); and there were normal findings from 15 procedures. No procedure induced any complication.

CONCLUSION

The use of the wireless endoscopy capsule detects significantly more clinically relevant intestinal lesions than video push-enteroscopy in patients with obscure digestive bleeding, raising the diagnostic yield to 67.2 %. Its influence on the clinical outcome for patients needs further investigation.

Wastewater treatment by radial freezing with stirring effects

Radial freezing experiments on wastewater models were conducted in the presence of imposed stirring in order to remove impurities. The studied samples (dilute Na-montmorillonite suspensions charged with nitrates and with zinc or lead) were placed inside a cylindrical annulus, cooled at a controlled temperature around -7 degrees C at its inner wall which rotated around a vertical axis. The freezing front propagated toward the still outer wall which was maintained at a constant temperature around +1 degrees C. Thanks to stirring, considerable purification rates up to 99.97% were attained. It was also demonstrated that combining radial freezing and stirring ended in residual concentrations which agreed with drinking water standards.

Structural organization of the group-1 chromosomes of two bread wheat sister lines

Eureka and Renan are two French bread wheat cultivars derived from a 4-way cross. Using molecular markers (essentially RFLPs), we studied the structure of the group-1 chromosomes of these two genotypes, their parents and a doubled-haploid (DH) population derived from their F(1). Using the DH population (102 lines), a molecular map of the three homoeologous group-1 chromosomes was produced and compared with the map established on another intervarietal cross: Courtot x Chinese Spring (Cadalen et al. 1997). The polymorphic markers were mapped on the DH population and characterized on the four grand-parents, allowing us to compare the structural organization of the group-1 chromosomes of Eureka and Renan and determine their origin. These chromosomes were very different, except for small regions (1AL proximal and 1BL distal) which were identical.

Hydrophobins in ectomycorrhizas: heterologous transcription of the Pisolithus HydPt-1 gene in yeast and Hebeloma cylindrosporum

Hydrophobins are fungal cell wall proteins involved in aggregation of hyphae. Upon the development of the ectomycorrhizal symbiosis between tree roots and fungal hyphae, the transcripts of hydrophobin genes markedly accumulated. As the precise role of these proteins in symbiosis is not yet known, we develop heterologous expression system of the Pisolithus hydrophobin HYDPt-1. This gene has been introduced in Saccharomyces cerevisiae and in the ectomycorrhizal basidiomycete Hebeloma cylindrosporum. Introns were required for hydPt-1 transcript accumulation in the basidiomycete H. cylindrosporum. Heterologous transcript accumulation did not alter the phenotype of either species. The lack of altered phenotype resulted from the absence of HYDPt-1 polypeptide accumulation in transformed strains.

Characterization of an Aux/IAA cDNA upregulated in Pinus pinaster roots in response to colonization by the ectomycorrhizal fungus Hebeloma cylindrosporum

• In an attempt to determine whether fungal auxin affects host plant gene expression during mycorrhizal formation, an auxin upregulated cDNA, Pp-iaa88, was isolated by differential screening of a cDNA library made from auxin-treated Pinus pinaster roots. • Pp-iaa88 codes for a polypeptide that shares extensive homology to auxin-inducible Aux/IAA proteins, which are supposed to act as transcription factors. Cycloheximide did not inhibit auxin-induced mRNA accumulation, indicating that Pp-iaa88 upregulation is a primary (direct) auxin response. • The level of Pp-iaa88 transcripts in roots increased following inoculation with either an indoleacetic acid-overproducing mutant or a wild-type strain of the ectomycorrhizal fungus Hebeloma cylindrosporum. With both strains, mRNA accumulation was detectable as soon as fungal hyphae reached the root and it increased during differentiation of symbiotic structures. The kinetics of Pp-iaa88 transcript accumulation was closely connected with the dynamics of symbiosis establishment and was more rapid with the mutant than with the wild-type strain. • As a putative transcription factor expressed at the very early stages of symbiosis establishment, Pp-iaa88 could play a key role in mycorrhizal formation.