Analysis of Arch Widths in Patients With Isolated Pierre Robin Sequence.

OBJECTIVE: To compare arch widths of patients with isolated Robin sequence (IRS) operated using modified von Langenbeck technique and modified Furlow double-opposing z-plasty. DESIGN: Retrospective, transversal study. SETTING: Hospital of Rehabilitation of Craniofacial Anomalies, University of São Paulo, Bauru, Brazil. PATIENTS: Three groups of patients were analyzed. Group VL comprised 30 patients with IRS operated by von Langenbeck technique (mean age of 8.1 years); group FL included 30 patients with IRS operated by Furlow technique (7.6 years); and the control group included 30 noncleft patients with class I occlusion (7.4 years). The palate repair was performed between 1.0 and 1.7 years of age in both study groups. Transversal measurements of maxillary and mandibular arches were performed digitally on 3D digital models. STATISTIC: The intergroup comparison was performed using analysis of variance and Tukey test. An independent t test was used to compare the complete and incomplete types of cleft in both study groups. The level of significance was 5%. RESULTS: No statistically significant difference was found between the VL and FL groups for maxillary and mandibular arches. However, both groups showed decreased transversal dimensions compared with the control group (P < .01) for both dental arches. No differences for arch widths were observed for complete or incomplete palatal clefts. CONCLUSIONS: No influence of palate repair techniques was observed in the transversal arch widths in patients with IRS. Children with IRS operated for palate repair showed constriction of the maxillary and mandibular dental arches compared with noncleft children regardless the palatal cleft extension.

Enhancement of denitrification in a down-flow hanging sponge reactor by effluent recirculation.

A down-flow hanging sponge reactor, constructed by connecting three identical units in series, was applied to the treatment of artificial wastewater containing phenol and ammonia under high salinity conditions (10.9 g-Cl(-)/L). The theoretical hydraulic retention time (HRT) of each unit was 4 h (total HRT = 12 h). To enhance denitrification by effluent recirculation, the effluent recirculation ratio was increased in increments ranging from 0.0 to 2.0. The concentration of total ammonia nitrogen (TAN), NO2-N, and NO3-N in the final effluent as a proportion of the TAN in the influent was determined to calculate the unrecovered, or denitrification, proportion. The denitrification proportion of the reactor was equivalent to 19.1 ± 14.1% with no effluent recirculation; however, this was increased to 58.6 ± 6.2% when the effluent recirculation ratio was increased to 1.5. Further increasing the effluent recirculation ratio to 2.0 resulted in a decrease in the denitrification proportion to 50.9 ± 9.3%. Activity assays of nitrification and denitrification, as well as 16S rRNA gene sequence analysis, revealed that denitrification occurred primarily in the upper sections of the reactor, while nitrification increased in the lower sections of the reactor. Gene sequence analysis revealed that denitrification by Azoarcus-like species using phenol as an electron donor was dominant.

Enrichment of marine anammox bacteria in Hiroshima Bay sediments.

Anaerobic ammonium oxidation (anammox) involves the microbiological oxidation of ammonium with nitrite as the electron acceptor and dinitrogen gas as the main product. The Scalindua species, an anammox genus that dominates natural habitats, plays an important role in catalysing the loss of nitrogen from marine environments. Until now, a few Scalindua species have been reported to be enriched from sea sediments. The objective of this study is to enrich marine anammox bacteria with coastal sediments in Hiroshima Bay as the inocula. The enrichment was achieved using a continuous upflow column reactor with synthetic sea water containing ammonium and nitrite. After 48 days of incubation, a simultaneous decrease in ammonium and nitrite was observed. A total nitrogen removal rate of 1.16 kg-N m(-3) day(-1) was attained after 306 days of incubation when the nitrogen loading rate was 1.32 kg-N m(-3) day(-1). Phylogenetic analysis revealed that the sequence similarity between the marine anammox-like bacteria in this reactor and the unidentified Candidatus Scalindua sp. was 96-98%. We successfully enriched marine anammox bacteria in the sediments of Hiroshima Bay by using synthetic sea water. Further studies are needed to investigate the characteristics of marine anammox bacteria, including optimal pH, temperature, and nitrogen loading rate.

Reduction of Alzheimer's disease amyloid-ß in plasma by hemodialysis and its relation to cognitive functions.

BACKGROUND/AIMS: Rapid removal of plasma amyloid-ß (Aß) by blood purification may serve as a peripheral Aß sink from the brain for Alzheimer's disease therapy. We investigated the reduction of plasma Aß during hemodialysis and cognitive states. METHODS: Aß concentrations and Mini-Mental State Examinations (MMSE) were investigated in 37 hemodialysis patients (68.9 ± 4.1 years). RESULTS: The dialyzers effectively removed Aß(1-40) and Aß(1-42), 63.9 ± 14.4 and 51.6 ± 17.0% at 4 h dialysis, resulting in the reduction of Aßs in whole-body circulation by 51.1 ± 8.9 and 32.7 ± 12.0%, respectively. Although the plasma Aßs before dialysis (750.8 ± 171.3 pg/ml for Aß(1-40)) were higher than those reported for Alzheimer's disease patients, the cognitive states of hemodialysis patients were relatively normal, especially of longer dialysis vintages. CONCLUSIONS: Dialyzers effectively reduced Aßs in whole-body circulation. Repeated rapid decrease of plasma Aßs might maintain cognitive state.

Closed DHS system to prevent dissolved methane emissions as greenhouse gas in anaerobic wastewater treatment by its recovery and biological oxidation.

Anaerobic wastewater treatment has been focused on its eco-friendly nature in terms of the improved energy conservation and reduction in carbon dioxide emissions. However, the anaerobic process discharges unrecovered methane as dissolved methane. In this study, to prevent the emission of dissolved methane from up-flow anaerobic sludge blanket (UASB) reactors used to treat sewage and to recover it as useful gas, we employed a two-stage down-flow hanging sponge (DHS) reactor as a post-treatment of the UASB reactor. The closed DHS reactor in the first stage was intended for the recovery of dissolved methane from the UASB reactor effluent; the reactor could successfully recover an average of 76.8% of the influent dissolved methane as useful gas (containing methane over 30%) with hydraulic retention time of 2 h. During the experimental period, it was possible to maintain the recovered methane concentrations greater than 30% by adjusting the air supply rate. The remaining dissolved methane after the first stage was treated by the next step. The second closed DHS reactor was operated for oxidation of the residual methane and polishing of the remaining organic carbons. The reactor had a high performance and the influent dissolved methane was mostly eliminated to approximately 0.01 mgCOD L(-1). The dissolved methane from the UASB reactor was completely eliminated--by more than 99%--by the post-treatment after the two-stage closed DHS system.

Effect of sponge volume on the performance of down-flow hanging sponge system treating UASB reactor effluent.

The performance of down-flow hanging sponge (DHS) system treating UASB reactor effluent at different sponge volume of 38.2, 28.7, 19.1 and 9.6% was investigated. The hydraulic retention time (HRT) and flow rate were kept constant at 2.6 h and 0.46 m(3)/day, respectively. The results obtained indicated that reducing the sponge volume of the DHS system from 38.2 to 19.1% significantly decreased the removal efficiency of COD(total) from 80 +/- 8 to 62 +/- 14%; COD(soluble) from 71.2 +/- 10 to 53.7 +/- 18% and COD(particulate) from 86 +/- 10 to 62 +/- 15%. With further reduction of the sponge volume down to 9.6%, the removal efficiency was dropped to 54 +/- 15% for COD(total); 44.1 +/- 14% for COD(soluble) and 42 +/- 12% for COD(particulate). Likewise, the nitrification efficiency and fecal coliform (FC) removal was strongly affected by decreasing the sponge volume of the DHS system, i.e., the nitrification efficiency was dropped by a value of 48.3% when reducing the sponge volume of the DHS system from 38.2 to 19.1%. At sponge volume of 38.2%, the DHS system removes 2.6 +/- 0.3 log(10)/100 ml of FC which is significantly higher than that at sponge volume of 28.7, 19.1 and 9.6%. Accordingly, it is recommended to design and operate such a system at a bulk sponge volume not exceeding 38.2% of the total reactor volume and at an HRT of 2.6 h.

Transcellular relocation of tetrahydrobiopterin across Caco-2 cells: a model study of tetrahydrobiopterin absorption through epithelial cells of intestinal mucosa.

Oral administration of tetrahydrobiopterin (BH(4)) has been known to be effective in treating BH(4)-deficient patients. It has long been established that BH(4) is absorbed by the intestinal mucosa. However, the mechanism for translocation of BH(4) across epithelial cells has not been elucidated. In order to study BH(4) transport mechanisms, Caco-2 cells were employed in this study as an epithelial cell model. Caco-2 cells were cultured (2 x 10(4) cells/0.3 cm(2) well) for 21 days in a 24-well format using Transwell, a porous membrane-based culture dish, at which point they had established themselves as a tight sheet with a definite polarity. When BH(4) (100 micromol/L) was given to cells from the apical side, a considerable translocation toward their basolateral side was noted. The rate of BH(4) movement was around 150 pmol/h per well. This was comparable to the highest rate of BH(4) uptake or its release so far obtained using a monolayer culture of Caco-2 cells on an ordinary plastic plate. The transcellular movement of BH(4) across the polar culture on the porous membrane was effectively prevented by benzbromarone (10 micromol/L), a well known inhibitor of a group of transporters including urate transporter (URAT1), organic anion transporters (OATs), and multidrug-resistance-associated proteins (MRPs). It was thus concluded that in Caco-2 cells, BH(4) moved across the cell interior in a rapid ligand-specific manner that was driven by a transporter.

Tetrahydrobiopterin in intestinal lumen: its absorption and secretion in the small intestine and the elimination in the large intestine.

In treating hereditary deficiency of tetrahydrobiopterin (BH(4)), supplementation with BH(4) might be the ultimate choice of therapy. Oral administration of BH(4) has been believed to be inefficient owing to poor absorption of BH(4) in the intestine. In this study, we found a considerable amount of BH(4) as well as its oxidized pterins in the ingredients of intestinal lumen of mice when they were served food that did not contain significant amounts of biopterin. Ligation of the biliary duct led to significant decrease in luminal biopterin. Supplementation of BH(4) either by intraperitoneal administration of sepiapterin or of 6RBH(4) ((6R)-L-erythro-5,6,7,8-tetrahydrobiopterin) increased the BH(4) content in the intestinal lumen with a slight delay after the rise of blood BH(4). In these mice, biopterin appeared in the large intestine, caecum and colon, 2 h after the administration. The appearance of BH(4) in the large intestine was accompanied by a large amount of pterin (2-amino-4-hydroxypteridine). The amounts of biopterin + pterin that appeared in the large intestine after intraperitoneal administration of BH(4) were not greater than those found after oral administration at the same dose. When the mice were treated with a large dose of antibiotics prior to the BH(4) administration, the amount of biopterin increased in the caecum but the amount of pterin decreased greatly. These results suggested that a large proportion of BH(4) administered moved to the large intestine, where most biopterin was decomposed presumably by enteric bacteria. Nonetheless, most of the orally administered biopterin was taken up by the small intestine and the amount of biopterin reaching the large intestine was almost the same as that which appeared after direct injection of 6RBH(4) into the peritoneal cavity.

Optimization of the performance of an integrated anaerobic-aerobic system for domestic wastewater treatment.

A promising system consisting of Up-flow Anaerobic Sludge Blanket (UASB) and Down-Flow Hanging Sponge (DHS) system was investigated for removal of COD, BOD(5) fractions, ammonia and faecal coliform from domestic wastewater. The combined system was operated at different HRTs of 16, 11 and 8 h. The results indicate that increasing the total HRT from 8 to 16 h significantly (p < 0.05) improves the COD(total) and BOD(5 total) removal mainly as a result of a higher removal of COD(soluble), BOD(soluble), COD(particulate) and BOD(particulate). The main part of coarse suspended solids was removed in the UASB reactor (76.4+/-18%) and the remaining portion was adsorbed and/or enmeshed and degraded in the biomass of the DHS system. The combined system achieved a substantial reduction of total suspended solids (TSS) resulting in an average overall percentage removal of 94+/-6% (HRT = 16 h) and 89.5+/-7.8% (HRT = 8 h). Faecal coliform reduction was significantly improved when increasing the total HRT from 8 to 16 h. Residual counts of faecal coliform were 3.1 x 10(3)/100 ml at a total HRT of 16 h, and 2.8 x 10(4)/100 ml at total HRT of 8 h, corresponding to overall removal efficiency of 99.97+/-0.03 and 99.6+/-0.3% respectively. Despite the increase of ammonia concentration as a result of protein hydrolysis in the UASB reactor, a substantial removal of ammonia was achieved in the DHS system. The results obtained show that decreasing the OLR imposed to DHS system from 2.6 to 1.6 kg COD/m(3).d significantly (p < 0.05) improves the removal efficiency of ammonia by a value of 29%. However, the removal efficiency of ammonia is not further increased when decreasing the OLR from 1.6 to 1.3 kg COD/m(3).d. The discharged sludge from UASB + DHS system exerts a good settling property and partially stabilized.DHS profile results have shown that the major part of COD, BOD(5), and TSS was removed in the upper part of the system, consequently, the nitrification process was occurring in the lower part of the DHS system.

Influence of effluent-recirculation condition on the process performance of expanded granular sludge bed reactor for treating low strength wastewater.

A 2.0 L volume of EGSB reactor was operated at 20 degrees C for more than 500 days with 0.3-0.4 g COD/L of sucrose base wastewater to investigate the influence of effluent-recirculation on the process performance. At the start up period, the reactor was operated in EGSB mode with 5 m/h upflow velocity by continuous effluent recirculation. The COD loading was set to 7.2-9.6 kg COD/m(3) day with HRT of 1 hour. However, in this mode, EGSB reactor exhibited insufficient COD removal efficiency, i.e., 50-60%. Therefore, UASB mode (without recirculation, 0.7 m/h upflow velocity) was used for 30 minutes in every 40 minutes cycle to increase the COD concentration in the sludge bed. As a result, an excellent process performance was shown. The COD removal efficiency increased from 65% to 91% and the reactor could maintain a good physical property of retained sludge (sludge concentration: 33.4 g VSS/L and SVI: 25 mL/g VSS). Furthermore, retained sludge possessed sufficient level of methanogenic activity at 20 degrees C.

Changes of microbial characteristics of retained sludge during low-temperature operation of an EGSB reactor for low-strength wastewater treatment.

In this study, a lab scale EGSB reactor was operated for 400 days to investigate the influence of temperature-decrease on the microbial characteristic of retained sludge. The EGSB reactor was started-up at 15 degrees C seeding with 20 degrees C-grown granular sludge. The influent COD of synthetic wastewater was set at 0.6-0.8 gCOD/L. The process-temperature was stepwise reduced from 15 degrees C to 5 degrees C during 400 days operation. Decrease of temperature of the reactor from 15 degrees C to 10 degrees C caused the decline of COD removal efficiency. However, continuous operation of the EGSB reactor led the efficient treatment of wastewater (70% of COD removal, 50% of methane recovery) at 10 degrees C. We confirmed that the both acetate-fed and hydrogen-fed methanogenic activities of retained sludge clearly increased under 15 to 20 degrees C. Changes of microbial profiles of methanogenic bacteria were analyzed by 16S rDNA-targeted DGGE analysis and cloning. It shows that genus Methanospirillum as hydrogen-utilizing methanogen proliferated due to low temperature operation of the reactor. On the other hand, genus Methanosaeta presented in abundance as acetoclastic-methanogen throughout the experiment.

Performance comparison of a pilot-scale UASB and DHS system and activated sludge process for the treatment of municipal wastewater.

This study compares the performance of a pilot-scale combination of UASB and DHS system to that of activated sludge process (ASP) for the treatment of municipal sewage. Both systems were operated in parallel with the same sewage as influent. The study was conducted for more than 300 days, which revealed that organic removal efficiency of UASB+DHS system was comparable to that of ASP. Unfiltered BOD removal by both systems was more than 90%. However, UASB+DHS system outperformed ASP for pathogen removal. In addition, volume of excess sludge production from UASB+DHS was 15 times smaller than that from ASP. Moreover, unlike ASP, there is no requirement of aeration for the operation of UASB+DHS system, which makes it an economical treatment system. Considering the above observations, it was concluded that UASB+DHS system can be a cost-effective and viable option for the treatment of municipal sewage over ASP, especially for low-income countries.

Confocal endomicroscopy for the diagnosis of gastric cancer in vivo.

BACKGROUND AND STUDY AIMS: Advances in endoscopy have led to imaging of the details of the gastric mucosa, but the histological diagnosis usually has to be confirmed by endoscopic biopsy. A method of confocal endomicroscopy that has recently been developed allows the observation of living cells in vivo. Several investigators have reported that the technique is of value, but there have as yet been no studies describing its application in gastric cancer. PATIENTS AND METHODS: Twenty-seven patients with early gastric cancer underwent confocal endomicroscopy (Pentax EG-3870CIK; Pentax, Tokyo, Japan). After intravenous administration of fluorescein sodium, confocal images obtained from the normal mucosa and from cancerous lesions were interpreted by two pathologists independently and compared with the histological findings, including CD34 immunostaining of biopsy specimens or resected specimens from the same sites. RESULTS: Fluorescein yielded high-quality confocal images of the gastric mucosa; if cancer could be targeted (59%) images were mostly graded good. The images corresponded to the hematoxylin-eosin staining of transverse sections of specimens from the same sites. In the results for the interpretation by the two pathologists, the accuracy for the diagnosis of gastric cancer was 94.2% (pathologist A), and 96.2% (pathologist B), respectively. The accuracy decreased substantially when poor images and inaccessible lesions were included. CONCLUSIONS: Confocal endomicroscopy is useful in the diagnosis of gastric cancer but good quality images cannot always be obtained. In the future, it may allow virtual biopsy and help reduce unnecessary biopsies.

Effect of inorganic carbon on nitrite accumulation in an aerobic granule reactor.

Pilot scale experiments were performed to evaluate the potential of nitrite type nitrification process with an airlift reactor and granular biomass. Initially, oxygen limitation was used as the main control parameter for accumulating nitrite in the effluent. After 30 d operation, the maximum nitrite conversion rate reached 2.5 kgNO2-N m(-3) d(-1), average diameter of the granule was 0.7 mm. Nitrite type reaction continued over 100 d, but nitrate formation increased after 150 d of operation. Once nitrate formation increased, oxygen limitation could not eliminate nitrite oxidising bacteria from granule. To overcome nitrate formation, laboratory scale batch experiments were conducted and it revealed a high concentration of inorganic carbon which had a significant effect on nitrite accumulation. Following this new concept, inorganic carbon was fed to the pilot scale reactor by changing pH adjustment reagent from NaOH to Na2CO3 and nitrite accumulation was recovered successfully without changing DO concentration. These results show that a high concentration of inorganic carbon is one of the control parameters for accumulating nitrite in biofilm nitrification system.

On-site treatment of high-strength alcohol distillery wastewater by a pilot-scale thermophilic multi-staged UASB (MS-UASB) reactor.

A pilot-scale multi-staged UASB (MS-UASB) reactor with a working volume of 2.5 m3 was operated for thermophilic (55 degrees C) treatment of an alcohol distillery wastewater for a period of over 600 days. The reactor steadily achieved a super-high rate COD removal, that is, 60 kgCOD m(-3) d(-1) with over 80% COD removal. However, when higher organic loading rates were further imposed upon the reactor, that is, above 90 kgCOD m(-3) d(-1) for barely-based alcohol distillery wastewater (ADWW) and above 100 kgCOD m(-3) d(-1) for sweet potato-based ADWW, the reactor performance somewhat deteriorated to 60 and 70% COD removal, respectively. Methanogenic activity (MA) of the retained sludge in the thermophilic MS-UASB reactor was assessed along the time course of continuous run by serum-vial test using different substrates as a vial sole substrate. With the elapsed time of continuous run, hydrogen-utilizing MA, acetate-utilizing MA and propionate-fed MA increased at maximum of 13.2, 1.95 and 0.263 kgCOD kgVSS(-1) d(-1), respectively, indicating that propionate-fed MA attained only 1/50 of hydrogen-utilizing MA and 1/7 of acetate-utilizing MA. Since the ADWW applied herewith is a typical seasonal campaign wastewater, the influence of shut-down upon the decline in sludge MA was also investigated. Hydrogen-utilizing MA and acetate-utilizing MA decreased slightly by 3/4, during a month of non-feeding period, whereas propionate-fed MA were decreased significantly by 1/5. Relatively low values of propionate-fed MA and its vulnerability to adverse conditions suggests that the propionate degradation step is the most critical bottleneck of overall anaerobic degradation of organic matters under thermophilic condition.

Combining UASB and the "fourth generation" down-flow hanging sponge reactor for municipal wastewater treatment.

A "fourth generation" down-flow hanging sponge (DHS) Reactor has been developed and proposed as an improved variant of post-treatment system for UASB treating domestic wastewater. This paper evaluates the potential of the proposed combination of UASB and DHS as a sewage treatment system, especially for developing countries. A pilot-scale UASB (1.15 m3) and DHS (0.38 m3; volume of sponge) was installed in a municipal sewage treatment site and constantly monitored for 2 years. UASB was operated at an HRT of 6 h corresponding to an organic load of 2.15 kg-COD/m3 per day. Subsequently, the organic load in DHS was 2.35 kg-COD/m3 per day, operated at an HRT of 2 h. Organic removal by the whole system was satisfactory, accomplishing 96% of unfiltered BOD removal and 91% of unfiltered COD removal. However, nitrification decreased from 56% during the startup period to 28% afterwards. Investigation on DHS sludge was made by quantifying it and evaluating oxygen uptake rates with various substrates. Average concentration of trapped biomass was 26 g-VSS/L of sponge volume, increasing the SRT of the system to 100-125 d. Removal of coliforms obtained was 3-4 log10 with the final count of 10(3) to 10(4) MPN/100 ml in DHS effluent.

Efficient propagation of polarization from laser photons to positrons through compton scattering and electron-positron pair creation.

We have demonstrated for the first time the production of highly polarized short-pulse positrons with a finite energy spread in accordance with a new scheme that consists of two-quantum processes, such as inverse Compton scattering and electron-positron pair creation. Using a circularly polarized laser beam of 532 nm scattered off a high-quality, 1.28 GeV electron beam, we have obtained polarized positrons with an intensity of 2 x 10(4) e+ /bunch. The magnitude of positron polarization has been determined to be 73 +/- 15(stat) +/- 19(syst)% by means of a newly designed positron polarimeter.

The influence of physical-chemical and biological factors on the removal of faecal coliform through down-flow hanging sponge (DHS) system treating UASB reactor effluent.

The mechanism of faecal coliform removal in down-flow hanging sponge (DHS) system treating up-flow anaerobic sludge blanket (UASB) reactor effluent was the subject of this study. The results obtained revealed that the most important removal mechanism of faecal coliform in the DHS system is adsorption, followed by predation. Die-off is a relatively minor removal mechanism in the DHS system. The impact of physical and chemical factors such as contact time, effective sponge bulk volume and pH values on faecal coliform removal has been investigated. Increasing the contact time and sponge bulk volume exerted positive effect on the removal of faecal coliform. Changing the pH values between 6.5 and 9.0 did not show significant impact. Reducing sponge pore size from 1.92 to 0.56 mm, increased faecal coliform removal by a value of 1.3 log10.

Preliminary comparison of capsule endoscopy and double-balloon enteroscopy in patients with suspected small-bowel bleeding.

BACKGROUND AND STUDY AIMS: Capsule endoscopy (CE) and double-balloon enteroscopy (DBE) have been introduced as modalities for examining the entire small bowel. The aim of the present study was to assess the clinical effects of CE and DBE to consider the roles of CE and DBE and the indications for the procedures in patients with suspected small-bowel bleeding. PATIENTS AND METHODS: Between June 2004 and January 2005, 32 patients in whom a site of bleeding in the gastrointestinal tract had not been identified were enrolled in the study. Twenty-eight patients were examined with both methods. Bleeding sources were categorized as either A1 lesions (immediate hemostatic procedures required) or A2 lesions (close observation required). CE and DBE were evaluated with regard to whether or not they were capable of accessing the entire small bowel and provided a diagnosis, and the access and diagnostic rates were calculated. RESULTS: On CE, 13 patients were diagnosed with A1 lesions and six with A2 lesions; on DBE, 11 had A1 lesions and one had an A2 lesion. The access rate for the entire small intestine on CE was 90.6 % (29 of 32), significantly higher than with DBE at 62.5 % (10 of 16; P < 0.05). The diagnostic rate on CE was 59.4 % (19 of 32), higher than with DBE at 42.9 % (12 of 28; P = 0.30), but not significantly different. Among patients with A1 lesions who were diagnosed with DBE, histological diagnoses were obtained in six of the 11, and three patients were treated. CONCLUSIONS: In many suspected small-bowel bleeding cases, CE should be selected for the initial diagnosis and DBE for treatment or histopathological diagnosis after detection of the bleeding site on CE.

Quantitative analysis of the microvascular architecture observed on magnification endoscopy in cancerous and benign gastric lesions.

BACKGROUND AND STUDY AIMS: Gastric cancer remains a common malignant tumor in Japan. The aim of this study was to attempt a quantitative evaluation of the microvascular architecture observed by magnification endoscopy using image analysis, and to investigate whether this method is able to distinguish between gastric cancers and benign lesions. PATIENTS AND METHODS: A total of 132 patients were studied using magnification endoscopy, and image analysis was performed in 71 patients (32 patients with early gastric cancer, 39 patients with benign lesions). Analysis was not possible in the other 61 patients because the quality of the image was not good enough. A square region of interest was selected from the magnified images of the gastric mucosa. From this we extracted the vascular images corresponding to microvessels and calculated the mean caliber of vessels in the region of interest. RESULTS: Image analysis provided good-quality images of microvessels and enabled evaluation of the microvascular architecture. The mean caliber of vessels was 4.454 pixels in 17 differentiated adenocarcinomas, 4.319 pixels in 15 undifferentiated adenocarcinomas, and 4.034 pixels in the 39 benign lesions. This represented a significant difference between gastric cancers and benign lesions (P<0.0001). Histopathological investigation of surgically resected tumors demonstrated the mean caliber of microvessels in cancerous lesions to be greater than that of microvessels in the surrounding mucosa. CONCLUSIONS: Image analysis was useful for evaluating the microvascular architecture of the gastric mucosa, and calculation of the mean caliber of the vessels may prove helpful in the differential diagnosis of gastric cancers. However, analysis was not possible in 61 of the 132 patients studied because of inadequate image quality, and this represents a significant limitation of this diagnostic method.