Wildfire and African dust aerosol oxidative potential, exposure and dose in the human respiratory tract

Exposure to wildfire smoke and dust can severely affect air quality and health. Although particulate matter (PM) levels and exposure are well-established metrics linking to health outcomes, they do not consider differences in particle toxicity or deposition location in the respiratory tract (RT). Usage of the oxidative potential (OP) exposure may further shape our understanding on how different pollution events impact health. Towards this goal, we estimate the aerosol deposition rates, OP and resulting OP deposition rates in the RT for a typical adult Caucasian male residing in Athens, Greece. We focus on a period when African dust (1-3 of August 2021) and severe wildfires at the northern part of the Attika peninsula and the Evia island, Greece (4-18 of August 2021) affected air quality in Athens. During these periods, the aerosol levels increased twofold leading to exceedances of the World Health Organization (WHO) [15(5) μg m-3] PM10 (PM2.5) air quality standard by almost 100 %. We show that the OP exposure is 1.5-times larger during the wildfire smoke events than during the dust intrusion, even if the latter was present in higher mass loads - because wildfire smoke has a higher specific OP than dust. This result carries two important implications: OP exposure should be synergistically used with other metrics - such as PM levels - to efficiently link aerosol exposure with the resulting health effects, and, certain sources of air pollution (in our case, exposure to biomass burning smoke) may need to be preferentially controlled, whenever possible, owing to their disproportionate contribution to OP exposure and ability to penetrate deeper into the human RT.

Recent Upgrades of the EOLE and AIAS Lidar Systems of the National Technical University of Athens Operating Since 2000 in Athens, Greece

The technical specifications and advances/ upgrades of the stationary (EOLE) and mobile (AIAS) lidars located at the National Technical University of Athens (NTUA) are presented in this paper. EOLE is a multi-wavelength combined backscatter/Raman lidar system, which is part of the EARLINET lidar network since May 2000. AIAS is a mobile 532 nm elastic depolarization lidar system. Both instruments have been upgraded during 2019, in the frame of PANACEA to be part of the Greek National Research Infrastructure for aerosol research, under the umbrella of the European Strategy Forum on Research Infrastructures (ESFRI).

Aerosol Typing Based on Multiwavelength Lidar Observations and Meteorological Model Data

Three different aerosol classification methods have been used to characterize lidar observations: Mahalanobis distance automatic aerosol type classification, Neural Network Aerosol Typing Algorithm (NATALI) and Source and Analysis (SCAN) aerosol classification. The data selection has been made through the EARLINET database depending on the 3b+2a+1δ optical property availability. One hundred aerosol layers from four EARLINET stations (Bucharest, Kuopio, Leipzig and Potenza) have been classified. We present a typical case study of aerosol characterization observed by the MUSA system over Potenza on the 11th of April 2016 (20:30-21:30 UTC).

Optical Properties of Canadian Biomass Burning Particles Over Europe Observed with Calipso and Ground-Based Lidar Systems

A long-lasting biomass burning event affected Europe from 27 August to 3 September 2018. The biomass burning aerosol layers were observed with ground- and space-based lidars in heights ranged between 2-7 km (a.s.l.). The mean backscatter coefficient for the ground-based stations ranged between 0.29 and 1.51 Mm-1sr-1, while the CALIPSO retrieved values ranged between 0.43 and 1.83 Mm-1sr-1. Moreover, the mean Ångström exponent (AEb) values, relevant to backscatter, ranged from 0.83 to 1.04 for the aforementioned lidar stations. At the same time, the mean AEb values obtained from CALIPSO ranged between 0.17 and 1.89. The mean particle depolarization ratio ranged between 0.037 and 0.080.

Synergetic Observations by Ground-Based and Space Lidar Systems and Aeronet Sun-Radiometers: A Step to Advanced Regional Monitoring of Large Scale Aerosol Changes

The paper presents the preliminary results of the lidar&radiometer measurement campaign (LRMC-2017), estimation of statistical relations between aerosol mode concentrations retrieved from CALIOP and ground-based lidar stations and case study of fire smoke events in the Eurasian regions using combined ground-based and space lidar and radiometer observations.

Biomass Burning Measurements in Earlinet

The biomass burning events are analyzed using the EARLINET-ACTRIS atmospheric profiling of aerosols using lidars. The period of 2008-2017 was chosen to analyze all the events assigned in the EARLINET database under Forest Fire category. A number of fourteen stations were considered. The data provided, ranged from complete data sets (backscatter, extinction and particle linear depolarization ratio) to single profiles (backscatter coefficient). A thorough quality control was performed. Smoke layers geometry was evaluated and the mean properties within each layer were computed. The Hysplit backward-trajectory technique and the FIRMS fire database were used to double check the source of each layer. Discussions were made under the following scenarios: fire events seen by two stations, long range transport from North America, and geographical clusters.

Saharan Dust Events Over the Northern Mediterranean: 4 Years of Measurements Over 4 Earlinet Stations

Four years (2014-2017) of observations of depolarization Raman Lidar systems of four EARLINET (European Aerosol research Lidar Network) stations [from West to East: Granada (Spain), Potenza (Italy), Athens (Greece) and Limassol (Cyprus)] were collected and used to a statistical analysis of Saharan dust events over Mediterranean basin.

In this study, emphasis is given to the consistency of the particle linear depolarization ratio (δp532), the extinction-to-backscatter ratio mentioned as Lidar Ratio (LR532) and the Aerosol Optical Thickness (AOT532) within the observed Saharan dust layers, corresponding to the visible range (532 nm). Geometrical properties and clusters of aerosol mixtures are also presented. Our clustering was based on previous classification by airborne High Spectral Resolution Lidar (HSRL) observations and was further supported by backward trajectory analysis. We found mean δp532 values of 0.24±0.05, 0.26±0.06, 0.28±0.05 and 0.28±0.04, mean LR532 values of 52±8 sr, 51±9 sr, 52±9 sr and 49±6 sr, mean AOT532 values of 0.40±0.31, 0.11±0.07, 0.12±0.10 and 0.32±0.17 and mean layer thicknesses of 3392±1458 m, 2150±1082 m, 1872±816 m and 1716±567 m for Granada, Potenza, Athens and Limassol respectively.

This work could assist in bridging the existing gaps related to the extensive and intensive dust aerosol properties over the Mediterranean and enriching the bibliography about mixed aerosol layers from different sources (e.g. dust and biomass burning (BB) aerosols, dust and urban/ industrial aerosols).

ATHLI16: the ATHens Lidar Intercomparison campaign

The results of the ATHLI16 (ATHens Lidar Intercomparison) campaign, held in Athens from 26/09 to 07/10 2016 are presented. The campaign was performed within the Lidar Calibration Centre activities (EU H2020 ACTRIS-2 project) to assess the performance of the EOLE lidar system (NTUA, Athens, Greece), operating within EARLINET, by comparing against the EARLINET reference lidar system MUSA (CNR-IMAA, Potenza, Italy). For both lidars only products retrieved by the EARLINET Single Calculus Chain have been compared.

Aerosol optical properties variability during biomass burning events observed by the eole-aias depolarization lidars over Athens, Greece (2007-2016)

The EOLE multi-wavelength aerosol Ramandepolarization lidar, and the AIAS depolarization lidar, in synergy with a sun photometer (CIMEL), were used, in the period 2007-2016, to provide the vertical profiles of the aerosol optical properties over Athens, Greece. More than 30 biomass burning events (fresh and aged smoke particles) were observed, with smoke layers between 1.5 up to 4-5 km height, while their duration ranged from 1-3 days. Lidar ratio (LR) values ranged from 40-105 sr (at 355 nm) and from 40-100 sr (at 532 nm), while the linear particle depolarization ratio (LPDR) at both 355 and 532 nm, remained <7%. The extinction-related Ångström exponent (AEa) at 355 nm/532 nm) ranged from 0.3 to 2.1. Additionally, a case of a near-range transport of biomass burning aerosols arriving over Athens up to 4 km height, between 27 and 28 June 2016, was studied. For this case, we found LRs of the order of 70±5 sr (355 nm) and 65±15 sr (532 nm) and AEa(355 nm/532 nm) around 1.

Earlinet validation of CATS L2 product

The Cloud-Aerosol Transport System (CATS) onboard the International Space Station (ISS), is a lidar system providing vertically resolved aerosol and cloud profiles since February 2015. In this study, the CATS aerosol product is validated against the aerosol profiles provided by the European Aerosol Research Lidar Network (EARLINET). This validation activity is based on collocated CATS-EARLINET measurements and the comparison of the particle backscatter coefficient at 1064nm.

Seventeen-year systematic measurements of dust aerosol optical properties using the eole ntua lidar system (2000-2016)

A comprehensive analysis of the seasonal variability of the optical properties of Saharan dust aerosols over Athens, Greece, is presented for a 17-year time period (2000-2016), as derived from multi-wavelength Raman lidar measurements (57 dust events with more than 80 hours of measurements). The profiles of the derived aerosol optical properties (aerosol backscatter and extinction coefficients, lidar ratio and aerosol Ångström exponent) at 355 nm are presented. For these dust events we found a mean value of the lidar ratio of ~52±13 sr at 355 nm and of ~58±8 sr (not shown) at 532 nm (2-4 km a.s.l. height). For our statistical analysis, presented here, we used monthly-mean values and time periods under cloud-free conditions. The number of dust events was greatest in late spring, summer, and early autumn periods. In this paper we also present a selected case study (04 April 2016) of desert dust long-range transport from the Saharan desert.

Screening of the DNA mismatch repair genes MLH1, MSH2 and MSH6 in a Greek cohort of Lynch syndrome suspected families

Background

Germline mutations in the DNA mismatch repair genes predispose to Lynch syndrome, thus conferring a high relative risk of colorectal and endometrial cancer. The MLH1, MSH2 and MSH6 mutational spectrum reported so far involves minor alterations scattered throughout their coding regions as well as large genomic rearrangements. Therefore, a combination of complete sequencing and a specialized technique for the detection of genomic rearrangements should be conducted during a proper DNA-testing procedure. Our main goal was to successfully identify Lynch syndrome families and determine the spectrum of MLH1, MSH2 and MSH6 mutations in Greek Lynch families in order to develop an efficient screening protocol for the Greek colorectal cancer patients' cohort.

Methods

Forty-two samples from twenty-four families, out of which twenty two of Greek, one of Cypriot and one of Serbian origin, were screened for the presence of germline mutations in the major mismatch repair genes through direct sequencing and MLPA. Families were selected upon Amsterdam criteria or revised Bethesda guidelines.

Results

Ten deleterious alterations were detected in twelve out of the twenty-four families subjected to genetic testing, thus our detection rate is 50%. Four of the pathogenic point mutations, namely two nonsense, one missense and one splice site change, are novel, whereas the detected genomic deletion encompassing exon 6 of the MLH1 gene has been described repeatedly in the LOVD database. The average age of onset for the development of both colorectal and endometrial cancer among mutation positive families is 43.2 years.

Conclusion

The mutational spectrum of the MMR genes investigated as it has been shaped by our analysis is quite heterogeneous without any strong indication for the presence of a founder effect.

Wireless capsule endoscopy in children: a study to assess diagnostic yield in small bowel disease in paediatric patients

BACKGROUND AND AIM

Small bowel disease in the paediatric population is varied and to date has relied on indirect l modalities such as small bowel follow-through with attendant radiation exposure. Wireless capsule endoscopy (WCE) has the potential to provide a safer and more effective means of investigating the paediatric small bowel. The aim of our study was to prospectively assess the diagnostic yield of WCE compared with standard investigation in children with suspected small bowel disease.

METHODS

Twenty-eight consecutive patients, median age 12.5 y (range, 9.4-15.9) with suspected small bowel disease were investigated with WCE. This included 16 patients with suspected small bowel Crohn disease (CD) (10 newly diagnosed; 6 known cases), 6 with obscure or occult gastrointestinal bleeding (GIB), 3 with Peutz-Jegher polyposis (PJP), 2 with protein-losing enteropathy and 1 with recurrent abdominal pain. All of the patients had preceding upper gastrointestinal endoscopy (OGD) and ileocolonoscopy, and 24 had a barium meal and follow-through (BMFT). Images were downloaded and analysed and results compared with the endoscopic and radiological findings.

RESULTS

Three patients were unable to swallow the capsule (1 CD, 1 PJP and 1 GIB). Two of these patients (1 GIB, 1 PJP) had the capsule placed in the stomach endoscopically and completed the WCE uneventfully thereafter. In 3 patients (CD group) the capsule remained in the stomach and/or proximal duodenum and no small bowel images were obtained. Hence, 24 patients had successful completion of the WCE through the small bowel, 23 of whom had clinically relevant findings identified. In all patients with CD who had successful WCE studies (12/16), small bowel disease was identified (11/12 active disease, 1/12 chronic disease). A possible small bowel bleeding source was identified in all 6 patients with GIB. Two patients with GIB also underwent push enteroscopy and 1 of these had a bleeding source identified. The 2 patients with protein-losing enteropathy had extensive patchy lymphangiectasia of the jejunum and ileum, not detected at OGD. The patient with abdominal pain had an intussusception of the upper jejunum. The 2 PJP patients had small bowel polyps identified, which were not detected at BMFT. WCE was more sensitive for small bowel pathology than both BMFT (19 vs 5; 26% sensitivity compared with WCE) and endoscopic investigations (23 vs 10; 43.4% sensitivity compared with WCE). Two patients with CD had delayed capsule transit.

CONCLUSIONS

WCE led to a positive alteration in management in 18/24 (75%) of patients whose small bowel was examined by WCE and in 18/28 (64.3%) who were admitted to the study. WCE was safe, well tolerated, and more sensitive than radiological and standard endoscopic modalities in the detection of small bowel CD distribution, GIB source, and presence of polyps in children.

Serological markers (anti-Saccharomyces cerevisiae mannan antibodies and antineutrophil cytoplasmic antibodies) in inflammatory bowel disease: diagnostic utility and phenotypic correlation

We have evaluated the utility of antineutrophil cytoplasmic antibodies and anti-Saccharomyces cerevisiae mannan antibodies for distinguishing Crohn's disease from ulcerative colitis and other diarrheal illnesses by evaluating sera from 396 patients. Sensitivity, specificity, and phenotypic correlations were investigated. The implications of our findings for implementing these tests in routine clinical testing are discussed.

Molecular characterization of the bacteria adherent to human colorectal mucosa

AIMS

To study large intestinal mucosal bacterial communities by Denaturing Gradient Gel Electrophoresis (DGGE) profiling and sequencing of 16S rRNA gene polymerase chain reaction (PCR) products amplified from DNA extracted from colorectal biopsies taken from healthy individuals. The specific aims were to determine how similar the mucosa-associated bacterial communities are within and between individuals and also to characterize the phylogenetic origin of isolated DGGE bands.

METHODS AND RESULTS

Human colorectal biopsies were taken at routine colonoscopy from 33 patients with normal looking mucosa. The DNA was extracted directly from single biopsies and the bacterial 16S rDNA PCR amplified. The PCR products were profiled using DGGE to generate a fingerprint of the dominant members of the bacterial community associated with the biopsy. The reproducibility of this method was high (>98%). Washed and unwashed biopsies gave similar DGGE banding patterns (Median Similarity Coefficient - MSC 96%, InterQuartile Range - IQR 3.0%, n = 5). Adjacent biopsies sampled from the same patient using different forceps gave similar DGGE profiles (MSC 94%, n = 2). Two colorectal biopsies sampled at locations 2-5 cm apart, from each of 18 patients, resulted in very similar profiles (MSC 100%, IQR 2.8%). Biopsies sampled from different locations within the large intestine of the same patient also gave similar DGGE profiles (MSC 98% IQR 3.3%n = 6). Although all patients (n = 33) gave different DGGE profiles, some similarity (c. 34%) was observed between profiles obtained from 15 patients arbitrarily selected. 35 DGGE bands were excised and sequenced. Many were found to be most closely related to uncultured bacterial sequence entries in the Genbank database. Others belonged to typical gut bacterial genera including Bacteroides, Ruminococcus, Faecalibacterium and Clostridium.

CONCLUSIONS

Bacterial communities adherent to colorectal mucosa within a normal patient show little variation; in contrast, mucosal bacterial communities sampled from different patients with normal colorectal mucosa show a high degree of variation.

SIGNIFICANCE AND IMPACT OF THE STUDY

This research demonstrates that DGGE profiling of 16S rRNA gene PCR products amplified from DNA extracted directly from mucosal samples offers fresh insight into the bacterial communities that are adherent to colorectal mucosa. These findings are important with respect to further studies on the gastrointestinal tract in health and disease.

Molecular characterization of rectal mucosa-associated bacterial flora in inflammatory bowel disease

BACKGROUND

Colorectal bacteria may play a role in the pathogenesis of inflammatory bowel disease (IBD). To test the hypothesis that, in affected patients, the numbers of potentially protective mucosal bacteria might be reduced and pathogenic species increased, we compared rectal mucosa-associated flora in patients with IBD and normal controls.

METHODS

Snap-frozen rectal biopsies taken at routine diagnostic colonoscopy from 33 patients with ulcerative colitis, 6 patients with Crohn's disease, and 14 controls with normal colonoscopy were processed, and individual bacterial groups were counted using fluorescent in situ hybridization.

RESULTS

Bacteria were mostly found apposed to the epithelial surface and within crypts. Epithelium-associated counts of bifidobacteria in active [median 15/mm of epithelial surface (range, 4-56), n = 14] and quiescent ulcerative colitis [26/mm (range, 11-140), n = 19] were lower than in controls [56/mm (range, 0-144), n = 14; P = 0.006 and P = 0.03, respectively]. Conversely, epithelium-associated Escherichia coli counts were higher in active [82/mm (range, 56-136)] than inactive ulcerative colitis [6/mm (range, 0-136), P = 0.0001] or controls [0/mm (range, 0-16), P < 0.0001]. Epithelium-associated clostridia counts were also higher in active [3/mm (range, 0-9)] than inactive colitis [0/mm (range, 0-9), P = 0.03] or controls [0/mm (range, 0-1); P = 0.0007]. Epithelium-associated E. coli counts were higher in Crohn's disease [42/mm (range, 3-90), n = 6] than controls (P = 0.0006). E. coli were also found as individual bacteria and in clusters in the lamina propria in ulcerative colitis and Crohn's disease but in none of the controls (P < 0.01). Numbers of Lactobacillus and Bacteroides showed no differences between patient groups.

CONCLUSIONS

The reduction in mucosa-associated bifidobacteria and increase in E. coli and clostridia in patients with IBD supports the hypothesis that an imbalance between potentially beneficial and pathogenic bacteria may contribute to its pathogenesis.

Enteric infection in relapse of inflammatory bowel disease: importance of microbiological examination of stool

OBJECTIVE

Previous reports have suggested that diarrhoeal relapses of inflammatory bowel disease (IBD) may be associated or confused with enteric infection, and that treatment of such infections with appropriate antibiotics may be beneficial. To re-evaluate the suggestion that enteric infection is rare and microbiological testing of stool not routinely necessary in patients presenting with relapse of IBD, we have reviewed the incidence of concurrent infection in patients presenting in relapse over a recent 5-year period.

METHODS

Stool microbiology results relating to relapses of IBD during the period 1997-2001 were obtained retrospectively. Relapse was confirmed by standard clinical, sigmoidoscopic and laboratory criteria.

RESULTS

During the period 1997-2001 there were 237 relapses in 213 patients. Enteric infection was found in 25 (10.5%) relapses in 24 patients; in seven patients, infection was associated with the initial presentation of their IBD. Clostridium difficile toxin was detected in 13 (5.5%) instances; the 12 other infections (5% relapses) were Campylobacter spp. (five), Entamoeba histolytica (three), Salmonella spp. (one), Plesiomonas shigelloides (one), Strongyloides stercoralis (one) and Blastocystis hominis (one). There was a significant association between infection and the need for hospital admission. Of the 13 relapses associated with C. difficile, ten were in outpatients, seven patients had undergone previous antibiotic treatment, and four patients were presenting with IBD for the first time. All relapses resolved satisfactorily after treatment with antibiotics with or without corticosteroids.

CONCLUSIONS

The high prevalence of enteric infections, of which C. difficile was the most common, indicates that all patients presenting with relapse of IBD should have stool examined microbiologically.

Oral iron therapy in inflammatory bowel disease: usage, tolerance, and efficacy

BACKGROUND

Iron deficiency is common in inflammatory bowel disease (IBD). Anecdotal evidence suggests that oral iron is poorly tolerated and may exacerbate disease activity in patients with IBD. AIM The aim of this study was to retrospectively compare usage, tolerance, and efficacy of oral iron therapy in patients with IBD and noninflammatory causes of iron deficiency.

METHODS

Case records of 277 patients with IBD and 24 non-IBD iron-deficient control patients covering a 4-year period were retrospectively analyzed.

RESULTS

Fifty-three of 277 (19%) of the patients with IBD studied had received oral iron. In only 40% of the patients who had IBD and 63% of the patients who did not (p = not significant) was iron deficiency formally confirmed before treatment. Intolerance to iron was reported in only 25% of the patients who had IBD and 17% of the patients who did not (p = not significant). In only two of eight adequately monitored iron-intolerant patients with IBD was iron therapy associated with an increase in inflammatory markers. When formally checked, iron repletion was successfully achieved as frequently in patients who had IBD (59%) as in patients who did not (45%).

CONCLUSION

Iron therapy is often used without a formal diagnosis of iron deficiency having been made, at least in part because of the difficulty in making this diagnosis using ferritin, an acute-phase protein. Patients with IBD are no more intolerant of oral iron than other patients and have similar rates of repletion.

Wireless capsule endoscopy: a comparison with push enteroscopy in patients with gastroscopy and colonoscopy negative gastrointestinal bleeding

BACKGROUND

The development of wireless capsule endoscopy allows painless imaging of the small intestine. Its clinical use is not yet defined. The aim of this study was to compare the clinical efficacy and technical performance of capsule endoscopy and push enteroscopy in a series of 50 patients with colonoscopy and gastroscopy negative gastrointestinal bleeding.

METHODS

A wireless capsule endoscope was used containing a CMOS colour video imager, transmitter, and batteries. Approximately 50,000 transmitted images are received by eight abdominal aerials and stored on a portable solid state recorder, which is carried on a belt. Push enteroscopy was performed using a 240 cm Olympus video enteroscope.

RESULTS

Studies in 14 healthy volunteers gave information on normal anatomical appearances and preparation. In 50 patients with gastrointestinal bleeding and negative colonoscopy and gastroscopy, push enteroscopy was compared with capsule endoscopy. A bleeding source was discovered in the small intestine in 34 of 50 patients (68%). These included angiodysplasia (16), focal fresh bleeding (eight), apthous ulceration suggestive of Crohn's disease (three), tumour (two), Meckel's diverticulum (two), ileal ulcer (one), jejunitis (one), and ulcer due to intussusception (one). One additional intestinal diagnosis was made by enteroscopy. The yield of push enteroscopy in evaluating obscure bleeding was 32% (16/50). The capsule identified significantly more small intestinal bleeding sources than push enteroscopy (p<0.05). Patients preferred capsule endoscopy to push enteroscopy (p<0.001).

CONCLUSIONS

In this study capsule endoscopy was superior to push enteroscopy in the diagnosis of recurrent bleeding in patients who had a negative gastroscopy and colonoscopy. It was safe and well tolerated.

Endoscopic ultrasound-guided biopsy for the diagnosis of focal lesions of the spleen

OBJECTIVES

Needle biopsy of splenic lesions using computed tomography (CT) or ultrasound (US) is difficult if the size of the lesion is small. It may be dangerous if the lesion is adjacent to the splenic hilum or located peripherally. We used endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) to elucidate the tissue diagnosis of splenic abnormalities.

METHODS

EUS-FNA was performed in 12 patients when US- or CT-guided biopsy was inconclusive (n = 5), was not attempted because of small tumor size (0.9-1.4 cm; N = 4), or was considered dangerous (n = 3). A linear echo-endoscope and 22-gauge needles were used for cytology and bacteriology.

RESULTS

The age of the patients was 19-68 yr (median 32 yr). Seven patients were male and five female. The size of the lesions was 0.8-4.2 cm (median 1.4 cm). Cytology was inadequate in one patient. Bacteriology was positive for Staphylococcus aureus and Serratia in one patient each, and cultures were positive for Mycobacterium tuberculosis in two patients. A positive diagnosis was made in 10 of 12 patients (83%). Final diagnoses were tuberculosis in two patients, Hodgkin's disease in two, sarcoidosis in two, abscesses in two, metastatic colon cancer in one, and infarction in one. Suspected recurrence of non-Hodgkin's lymphoma was not confirmed in one case. One patient experienced pain after puncture, but no hematoma was demonstrated on subsequent US examination.

CONCLUSIONS

EUS-FNA cytodiagnosis in patients with unknown splenic lesions seems feasible, even in very small foci, when CT- or US-guided biopsy fails. Additional material for bacteriology may show benign treatable diseases such as abscesses or tuberculosis.

Wireless capsule endoscopic detection of Meckel's diverticulum after nondiagnostic surgery

A patient aged 26 was investigated for recurrent severe gastrointestinal bleeding. Over a 4-year period, he was transfused more than 400 units of blood. Multiple investigations included three negative Meckel's scans. A right hemicolectomy for supposed angiodysplasia failed to control his bleeding. Wireless capsule endoscopy demonstrated the presence of a Meckel's diverticulum. At a repeat laparotomy, the ulcerated Meckel's diverticulum was identified and resected. The patient had no further bleeding and had a normal haemoglobin level on repeat blood tests up to 12 months after surgical excision of the diverticulum.