Molecular and FISH analyses of a 53-kbp intact DNA fragment inserted by biolistics in wheat (Triticum aestivum L.) genome

A large, 53-kbp, intact DNA fragment was inserted into the wheat ( Triticum aestivum L.) genome. FISH analyses of individual transgenic events revealed multiple insertions of intact fragments. Transferring large intact DNA fragments containing clusters of resistance genes or complete metabolic pathways into the wheat genome remains a challenge. In a previous work, we showed that the use of dephosphorylated cassettes for wheat transformation enabled the production of simple integration patterns. Here, we used the same technology to produce a cassette containing a 44-kb Arabidopsis thaliana BAC, flanked by one selection gene and one reporter gene. This 53-kb linear cassette was integrated in the bread wheat (Triticum aestivum L.) genome by biolistic transformation. Our results showed that transgenic plants harboring the entire cassette were generated. The inheritability of the cassette was demonstrated in the T1 and T2 generation. Surprisingly, FISH analysis performed on T1 progeny of independent events identified double genomic insertions of intact fragments in non-homoeologous positions. Inheritability of these double insertions was demonstrated by FISH analysis of the T1 generation. Relative conclusions that can be drawn from molecular or FISH analysis are discussed along with future prospects of the engineering of large fragments for wheat transformation or genome editing.

Structured surface reflector design for oblique incidence beam splitter at 610 GHz

An iterative alternate projection-based algorithm is developed to design structured surface reflectors to operate as beam splitters at GHz and THz frequencies. To validate the method, a surface profile is determined to achieve a reflector at 610 GHz that generates four equal-intensity beams towards desired directions of ±12.6° with respect to the specular reflection axis. A prototype is fabricated and the beam splitter behavior is experimentally demonstrated. Measurements confirm a good agreement (within 1%) with computer simulations using Feko, validating the method. The beam splitter at 610 GHz has a measured efficiency of 78% under oblique incidence illumination that ensures a similar intensity between the four reflected beams (variation of about 1%).

[Endoscopic submucosal dissection]

Endoscopic submucosal dissection (ESD) was developed in Japan but has now also become permanently established in various centers in Europe. ESD is an endoscopic en bloc mucosal resection technique for the treatment of early cancers with a diameter >1 cm and also superficial precancerous lesions, which could only be removed unsatisfactorily in several fragments or with uncertain lateral safety margins using previous loop excision procedures. Using ESD a lesion is excised after circular marking and generous submucosal injection with a safety margin of approximately 5 mm and subsequently resected at the level of the submucosa with a 1-3 mm short diathermic knife. ESD requires high technical skills in interventional endoscopy and is more time-consuming than snare resection techniques. However, numerous studies have shown a clear superiority for ESD with respect to the R0 resection rate and the local recurrence rate. The present article gives a current review of the use of ESD in the upper and lower gastrointestinal tract and demonstrates perspectives of the procedure.

Colon capsule endoscopy: European Society of Gastrointestinal Endoscopy (ESGE) Guideline

PillCam colon capsule endoscopy (CCE) is an innovative noninvasive, and painless ingestible capsule technique that allows exploration of the colon without the need for sedation and gas insufflation. Although it is already available in European and other countries, the clinical indications for CCE as well as the reporting and work-up of detected findings have not yet been standardized. The aim of this evidence-based and consensus-based guideline, commissioned by the European Society of Gastrointestinal Endoscopy (ESGE) is to furnish healthcare providers with a comprehensive framework for potential implementation of this technique in a clinical setting.

International Conference on Capsule and Double-Balloon Endoscopy (ICCD). Paris, 27-28 August 2010

This review reports the highlights of the first International Conference on Capsule and Double-Balloon Endoscopy, held in Paris (27 - 28 August 2010), under the chairmanship of Professor G. Gay (Nancy, France). The conference was devoted to the technical issues and clinical experience related to capsule endoscopy and double-balloon endoscopy (DBE), techniques that have been developed over the past decade for the endoscopic investigation of intestinal diseases. The conference focused on the technical advances of new-generation endoscopes and capsules and the clinical experience gained with capsule endoscopy and DBE. Important advances in the knowledge of obscure gastrointestinal bleeding, inflammatory bowel diseases, and celiac disease were also discussed. The second part of the conference was mainly devoted to the investigation of the colon and discussed the technical issues and results of initial controlled studies of the colonic capsule vs. conventional colonoscopy. In addition, the clinical usefulness of double colonoscopy was demonstrated in patients with previously failed colonoscopy. Finally, the role of DBE was discussed with respect to the investigation and treatment of patients with surgically modified anatomy. The conference was attended by 750 delegates and presented a unique opportunity for an in-depth review of the current knowledge in the field and to ascertain/determine the main lines for the future developments of capsule endoscopy and DBE.

CMOS compatible strategy based on selective atomic layer deposition of a hard mask for transferring block copolymer lithography patterns

A generic, CMOS compatible strategy for transferring a block copolymer template to a semiconductor substrate is demonstrated. An aluminum oxide (Al(2)O(3)) hard mask is selectively deposited by atomic layer deposition in an organized array of holes obtained in a PS matrix via PS-b-PMMA self-assembly. The Al(2)O(3) nanodots act as a highly resistant mask to plasma etching, and are used to pattern high aspect ratio (>10) silicon nanowires and nanopillars.

Different patterns of regulation for the copper and cadmium metallothioneins of the ectomycorrhizal fungus Hebeloma cylindrosporum

Metallothioneins (MTs) are small cysteine-rich peptides involved in metal homeostasis and detoxification. We have characterized two MT genes, HcMT1 and HcMT2, from the ectomycorrhizal fungus Hebeloma cylindrosporum in this study. Expression of HcMT1 and HcMT2 in H. cylindrosporum under metal stress conditions was studied by competitive reverse transcription-PCR analysis. The full-length cDNAs were used to perform functional complementation in mutant strains of Saccharomyces cerevisiae. As revealed by heterologous complementation assays in yeast, HcMT1 and HcMT2 each encode a functional polypeptide capable of conferring increased tolerance against Cd and Cu, respectively. The expression levels of HcMT1 were observed to be at their maximum at 24 h, and they increased as a function of Cu concentration. HcMT2 was also induced by Cu, but the expression levels were lower than those for HcMT1. The mRNA accumulation of HcMT1 was not influenced by Cd, whereas Cd induced the transcription of HcMT2. Zn, Pb, and Ni did not affect the transcription of HcMT1 or of HcMT2. Southern blot analysis revealed that both of these genes are present as a single copy in H. cylindrosporum. While the promoters of both HcMT1 and HcMT2 contained the standard stress response elements implicated in the metal response, the numbers and varieties of potential regulatory elements were different in these promoters. These results show that ectomycorrhizal fungi encode different MTs and that each of them has a particular pattern of expression, suggesting that they play critical specific roles in improving the survival and growth of ectomycorrhizal trees in ecosystems contaminated by heavy metals.

Chromosomal rearrangements in wheat: their types and distribution

Four hundred and sixty polyploid wheat accessions and 39 triticale forms from 37 countries of Europe, Asia, and USA were scored by C-banding for the presence of translocations. Chromosomal rearrangements were detected in 70 of 208 accessions of tetraploid wheat, 69 of 252 accessions of hexaploid wheat, and 3 of 39 triticale forms. Altogether, 58 types of major chromosomal rearrangements were identified in the studied material; they are discussed relative to 11 additional translocation types described by other authors. Six chromosome modifications of unknown origin were also observed. Among all chromosomal aberrations identified in wheat, single translocations were the most frequent type (39), followed by multiple rearrangements (9 types), pericentric inversions (9 types), and paracentric inversions (3 types). According to C-banding analyses, the breakpoints were located at or near the centromere in 60 rearranged chromosomes, while in 52 cases they were in interstitial chromosome regions. In the latter case, translocation breakpoints were often located at the border of C-bands and the euchromatin region or between two adjacent C-bands; some of these regions seem to be translocation "hotspots". Our results and data published by other authors indicate that the B-genome chromosomes are involved in translocations most frequently, followed by the A- and D-genome chromosomes; individual chromosomes also differ in the frequencies of translocations. Most translocations were detected in 1 or 2 accessions, and only 11 variants showed relatively high frequencies or were detected in wheat varieties of different origins or from different species. High frequencies of some translocations with a very restricted distribution could be due to a "bottleneck effect". Other types seem to occur independently and their broad distribution can result from selective advantages of rearranged genotypes in diverse environmental conditions. We found significant geographic variation in the spectra and frequencies of translocation in wheat: the highest proportions of rearranged genotypes were found in Central Asia, the Middle East, Northern Africa, and France. A low proportion of aberrant genotypes was characteristic of tetraploid wheat from Transcaucasia and hexaploid wheat from Middle Asia and Eastern Europe.

Esophageal capsule endoscopy in patients with suspected esophageal disease: double blinded comparison with esophagogastroduodenoscopy and assessment of interobserver variability

BACKGROUND AND STUDY AIMS

The study aim was to compare the diagnostic yield of capsule endoscopy and esophagogastroduodenoscopy (EGD) in patients with suspected esophageal disease. Secondary aims were to assess interobserver variability of capsule endoscopy readings and safety.

PATIENTS AND METHODS

In total, 98 patients (53 men, 53 +/- 13 years) with an indication for EGD were included. The patient population was artificially enriched to include two thirds of patients with abnormal esophageal findings at EGD, which was followed by capsule endoscopy. Capsule recordings were blindly read by three endoscopists, one from the center that recruited the patient and two from the other center. Study outcomes were the findings described on EGD and capsule endoscopy, agreement between EGD and capsule endoscopy for findings, quality of the capsule recording, and interobserver agreement for capsule endoscopy quality and findings.

RESULTS

EGD was normal in 34 patients and showed esophageal findings in 62 (esophagitis 28, hiatus hernia 21, varices 21, Barrett's esophagus 11, others 7). Average esophageal transit time of the capsule was 361 +/- 393 seconds. Capsule endoscopy was normal in 36 patients but detected esophagitis in 23, hiatus hernia in 0, varices in 23, Barrett's esophagus in 18, and others in 4. The positive predictive value of capsule endoscopy was 80.0 % and the negative predictive value was 61.1 %. Overall agreement per patient was moderate between EGD and capsule endoscopy for the per-patient (kappa = 0.42) and per-findings (kappa = 0.40) analyses. Interobserver agreement between capsule endoscopy readings was moderate for findings (kappa = 0.39) and quality assessment (kappa = 0.24). No adverse event was observed after either EGD or capsule endoscopy.

CONCLUSION

In this study, despite artificial prevalence enrichment, capsule endoscopy showed a moderate sensitivity and specificity in the detection of esophageal diseases.

Double-balloon colonoscopy after failed conventional colonoscopy: a pilot series with a new instrument

BACKGROUND AND STUDY AIMS

The endoscopes that were developed for double-balloon enteroscopy have been successfully used in cases of failed colonoscopy. This study was a pilot series in which a new colonoscope was tested that utilized this double-balloon principle.

PATIENTS AND METHODS

A total of 29 patients (5 men, 24 women; mean age 54 years) in whom conventional colonoscopy had failed were included in this study. Both the failed colonoscopy and the double-balloon colonoscopy procedures were performed under general anesthesia, the usual practice in France. A prototype instrument (working length 152 cm, diameter 9.4 mm) designed to incorporate the principles of double-balloon enteroscopy was used. The completeness of colonoscopy was assessed according to conventional criteria by the achievement of a stable position in the cecum. The indicatons for the procedure, the time to reach the cecum, the need for fluoroscopic control, and adverse events were recorded.

RESULTS

The previous colonoscopy failed due adhesions (n = 16), or to long or fixed loops (n = 13). Complete colonoscopy using the balloon method was achieved in 28/29 patients, taking an average time of 18 +/- 14 minutes; a long sigmoid loop limited the examination to the left flexure in one patient. Balloon colonoscopy using double-balloon methodology was used in 24 patients and the instrument was used without an overtube (i. e. using a single-balloon technique) in five patients. Fluoroscopy was used in 16 patients to monitor endoscope progression. No complications were reported.

CONCLUSIONS

Double-balloon colonoscopy enables full colonic examination in almost all patients with a previous incomplete colonoscopy. The overtube should be used in most cases. The use of fluoroscopic assessment of scope progression could be reduced further with increasing experience.

Measuring the quality of breast cancer care: National variation in the use of radiation among women under age 70

599

The National Quality Forum (NQF) recently adopted accountability cancer quality measures. Careful specification of target populations makes it so that omission of recommended therapy should be uncommon. One measure is use of radiation (RT) with breast conserving therapy (BCT) for women under age 70. This study examines nationwide use of RT in 2003–04 to determine the extent of variation and the need for improvement within these tight specifications. Methods: Data from 1,303 hospitals reporting to the National Cancer Data Base (NCDB) on women under age 70 treated with BCT in 2003–04 for invasive breast cancer were examined for factors associated with the use of RT in a multivariate model. The attributable provider unit was the reporting hospital. Results: Overall among 90,611 women under age 70, RT was reported with BCT in 74.5%. RT began within 6 months diagnosis in 54% and 1 yr in 74.2%. On multivariable analysis ( Table 1 ), RT was significantly less likely among African American and Hispanic vs. Caucasian women, those with less vs. more education, with no insurance or Medicaid vs. managed care, those with Charlson comorbidity > 0, women treated outside the Great Lakes/Midwest census regions, and treated at hospitals in the lower vs. higher quartiles of case volume. RT was administered to 73% of women in non-urban hospitals, and to 82% of women in urban hospitals. RT was administered to 75% and 77% of women age 50 - 59 and 60 - 69, respectively, compared to 68% and 72% of women age < 40 and 40 - 49. Conclusions: Despite limiting measurement to populations that should clearly receive RT with BCT, there are significant variations associated with patient and institutional characteristics. Reporting cancer care quality data is important, and the use of RT with BCT is a key quality measure for improvement and provider accountability.

[Table: see text]

No significant financial relationships to disclose.

Surface-wave interferometry on single subwavelength slit-groove structures fabricated on gold films

We apply the technique of far-field interferometry to measure the properties of surface waves generated by two-dimensional (2D) single subwavelength slit-groove structures on gold films. The effective surface index of refraction n(surf) measured for the surface wave propagating over a distance of more than 12 mum is determined to be n(surf) = 1.016+/-0.004, to within experimental uncertainty close to the expected bound surface plasmon-polariton (SPP) value for a Au/Air interface of n (spp) = 1.018. We compare these measurements to finite-difference-time-domain (FDTD) numerical simulations of the optical field transmission through these devices. We find excellent agreement between the measurements and the simulations for n(surf). The measurements also show that the surface wave propagation parameter k(surf) exhibits transient behavior close to the slit, evolving smoothly from greater values asymptotically toward k (spp) over the first 2-3 mum of slit-groove distance x(sg). This behavior is confirmed by the FDTD simulations.

Surface quality and surface waves on subwavelength-structured silver films

We analyze the physical-chemical surface properties of single-slit, single-groove subwavelength-structured silver films with high-resolution transmission electron microscopy and calculate exact solutions to Maxwell's equations corresponding to recent far-field interferometry experiments using these structures. Contrary to a recent suggestion the surface analysis shows that the silver films are free of detectable contaminants. The finite-difference time-domain calculations, in excellent agreement with experiment, show a rapid fringe amplitude decrease in the near zone (slit-groove distance out to 3-4 wavelengths). Extrapolation to slit-groove distances beyond the near zone shows that the surface wave evolves to the expected bound surface plasmon polariton (SPP). Fourier analysis of these results indicates the presence of a distribution of transient, evanescent modes around the SPP that dephase and dissipate as the surface wave evolves from the near to the far zone.

Surface wave generation and propagation on metallic subwavelength structures measured by far-field interferometry

Transmission spectra of metallic films or membranes perforated by arrays of subwavelength slits or holes have been widely interpreted as resonance absorption by surface plasmon polaritons. Alternative interpretations involving evanescent waves diffracted on the surface have also been proposed. These two approaches lead to divergent predictions for some surface wave properties. Using far-field interferometry, we have carried out a series of measurements on elementary one-dimensional subwavelength structures with the aim of testing key properties of the surface waves and comparing them to predictions of these two points of view.

Outcome of capsule endoscopy in determining indication and route for push-and-pull enteroscopy

BACKGROUND AND STUDY AIM

Video capsule endoscopy and push-and-pull enteroscopy (PPE), both allow a complete examination of the small bowel in patients with suspected intestinal disorders. Due to the invasiveness of PPE, indications should probably be selective. The aim of the present prospective study was to evaluate the outcome of an approach whereby capsule endoscopy was used to select patients in whom PPE was indicated.

PATIENTS AND METHODS

164 patients were included (90 men; age 54+/-18 years) with various indications for small-bowel investigation, such as obscure bleeding (n=88), suspected Crohn's (n=14) or celiac (n=12) disease, or known or strongly suspected localized diseases such as neoplasms (n = 18) for biopsy. Four patients with a suspected intestinal stenosis underwent PPE without prior capsule endoscopy. In the remaining 160 patients, who had a capsule endoscopy, PPE was selected if there were lesions requiring biopsy or angiodysplasias to be treated by argon plasma coagulation (APC). Regarding the insertion route, an anal PPE was indicated if the capsule transit time from ingestion to arrival at the lesion was >or= 75 % of the total time from ingestion to arrival at the cecum. After gut cleansing, PPE was performed with general anesthesia, and the small bowel was examined until the lesion was reached or the scope could not be advanced further. If the suspected lesion had not been reached, a second procedure was performed through the alternative route, under the same conditions.

RESULTS

The diagnostic yield of capsule endoscopy was 75 %. According to the indications, 47 PPE procedures were performed in 42 patients, including 33 through the oral route, 4 through the anal route and 5 combined ones. Indications were: suspicion of intestinal tumor (n=13), celiac disease with chronic bleeding (n=4), suspicion of Crohn's disease (n=3), treatment of significant arteriovenous malformations (AVMs) (n=10), diffuse enteropathies (n=3), nonsteroidal anti-inflammatory drug (NSAID)-related conditions (n=2), and obscure digestive bleeding (n=3). Lesions detected by capsule endoscopy were reached by PPE in all but two cases. The positive predictive value (PPV) of capsule endoscopy to make a correct indication for PPE was 94.7 % and the negative predictive value (NPV) was 98.3 %. The PPV and NPV of a time index of > 0.75 to start via the anal route were 94.7 % and 96.7 %. No complications were observed and all patients were discharged the day after the procedure. Follow-up at 9 months showed that capsule endoscopy followed by PPE had positively influenced the management of 90.5 % of the patients.

CONCLUSIONS

The use of capsule endoscopy as a filter for PPE results in effective management of patients with various intestinal diseases. Capsule endoscopy can also direct the choice of route of PPE; a time index of > 0.75 appears to reliably indicate an anal route so that a double procedure is required in only about 12 % of cases.

The auxin-inducible GH3 homologue Pp-GH3.16 is downregulated in Pinus pinaster root systems on ectomycorrhizal symbiosis establishment

In an attempt to determine whether auxin-regulated plant genes play a role in ectomycorrhizal symbiosis establishment, we screened a Pinus pinaster root cDNA library for auxin-upregulated genes. This allowed the identification of a cDNA, Pp-GH3.16, which encodes a polypeptide sharing extensive homologies with GH3 proteins of different plants. Pp-GH3.16 was specifically upregulated by auxins and was not affected by cytokinin, gibberellin, abscisic acid or ethylene, or by heat shock, water stress or anoxia. Pp-GH3.16 mRNAs were quantified in pine roots inoculated with two ectomycorrhizal fungi, Hebeloma cylindrosporum and Rhizopogon roseolus. Surprisingly, Pp-GH3.16 was downregulated following inoculation with both fungal species. The downregulation was most rapid on establishment of symbiosis with an indole-3-acetic acid (IAA)-overproducing mutant of H. cylindrosporum, which overproduced mycorrhizas characterized by a hypertrophic Hartig net. This indicates that, despite being auxin-inducible, Pp-GH3.16 can be downregulated on establishment of symbiosis with a fungus that releases auxin. By contrast, Pp-GH3.16 was not downregulated in pine root systems inoculated with a nonmycorrhizal mutant of H. cylindrosporum, suggesting that the downregulation we observed in mycorrhizal root systems was a component of the molecular cross-talk between symbiotic partners at the origin of differentiation of symbiotic structures.

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.