Near-complete absorption of intense, ultrashort laser light by sub-lambda gratings

We demonstrate near-100% light absorption and increased x-ray emission from dense plasmas created on solid surfaces with a periodic sub-lambda structure. The efficacy of the structure-induced surface plasmon resonance, responsible for enhanced absorption, is directly tested at the highest intensities to date (3 x 10{15} W cm{-2}) via systematic, correlated measurements of absorption and x-ray emission. An analytical grating model as well as 2D particle-in-cell simulations conclusively explain our observations. Our study offers a definite, quantitative way forward for optimizing and understanding the absorption process.

Effect of target shape on fast electron emission in femtosecond laser-plasma interactions

Fast electron emission from the interaction of femtosecond laser pulses with shaped solid targets has been studied. It is found that the angular distributions of the forward fast electrons are highly dependent upon the target shapes. The important roles played by the electrostatic fields built up at the non-laser-irradiated target surfaces and the collisions in the target are identified. Our two-dimensional particle-in-cell simulations with binary collisions included reproduce the main experimental observations.

Randomized comparison of two rescue therapies for Helicobacter pylori infection

BACKGROUND

Bismuth salts are not available worldwide. It remains unknown whether clarithromycin can replace bismuth salts as an adjuvant agent in the rescue regimens for Helicobacter pylori infection. We therefore designed the prospective study to compare the efficacies of two rescue therapies for H. pylori infection after standard triple therapies.

PATIENTS AND METHODS

Ninety-three patients who failed H. pylori eradication using proton pump inhibitor plus clarithromycin and amoxicillin were randomly assigned to undergo rescue therapy with esomeprazole, clarithromycin, tetracycline and metronidazole (ECTM group, n = 46) or esomeprazole, bismuth subcitrate, tetracycline and metronidazole (EBTM group, n = 47). Follow-up endoscopy was performed at 8 weeks after the end of treatment to assess the treatment response.

RESULTS

Intention-to-treat analysis demonstrated both groups had similar eradication rates (ECTM 74% vs. EBTM 77%; P = 0.76) and drug compliance (ECTM 94% vs. EBTM 96%; P = 0.68). However, the frequency of adverse events in the ECTM group was higher than that in EBTM group (ECTM 57% vs. EBTM 36%, P = 0.05). In the EBTM group, eradication rate of metronidazole-resistant strains was lower than that of metronidazole-susceptible strains (67%[8/12] vs. 100%[9/9], P = 0.05). However, eradication rates were similar between metronidazole-susceptible and metronidazole-resistant strains in ECTM group (69%[9/13] vs. 70%[7/10], P = 1.00).

CONCLUSIONS

The new ECTM second-line therapy can achieve similar eradication rate as standard EBTM therapy. It may be very useful in countries where bismuth salts are not available.

Effects of selective brain cooling in patients with severe traumatic brain injury: a preliminary study

We prospectively investigated non-invasive selective brain cooling (SBC) in patients with severe traumatic brain injury. Sixty-six in-patients were randomized into three groups. In one group, brain temperature was maintained at 33 - 35 degrees C by cooling the head and neck (SBC); in a second group, mild systemic hypothermia (MSH; rectal temperature 33 - 35 degrees C) was produced with a cooling blanket; and a control group was not exposed to hypothermia. Natural rewarming began after 3 days. Mean intracranial pressure 24, 48 or 72 h after injury was significantly lower in the SBC group than in the control group. Mean serum superoxide dismutase levels on Days 3 and 7 after injury in the SBC and MSH groups were significantly higher than in the control group. The percentage of patients with a good neurological outcome 2 years after injury was 72.7%, 57.1% and 34.8% in the SBC, MSH and control groups, respectively. Complications were managed without severe sequelae. Non-invasive SBC was safe and effective.

Tetracycline-resistant clinical Helicobacter pylori isolates with and without mutations in 16S rRNA-encoding genes

Tetracycline-resistant Helicobacter pylori strains have been increasingly reported worldwide. However, only a small number of tetracycline-resistant strains have been studied with regard to possible mechanisms of resistance and those studies have focused on mutations in the tetracycline binding sites of 16S rRNA-encoding genes. We here report studies of 41 tetracycline-resistant H. pylori strains (tetracycline MICs, 4 to 32 microg/ml) from North America (n = 12) and from East Asia (n = 29). DNA sequence analyses of 16S rRNA-encoding genes revealed that 22 (54%) of the resistant isolates carried one of five different single-nucleotide substitutions (CGA, GGA, TGA, AGC, or AGT) at the putative tetracycline binding site (AGA(965-967)). Single-nucleotide substitutions were associated with reduced ribosomal binding and with slightly increased tetracycline MICs (1 to 2 microg/ml). The 19 tetracycline-resistant isolates with no detectable mutations in the tetracycline binding site had normal tetracycline-ribosome binding. All tetracycline-resistant isolates, including those with and those without mutations in the tetracycline binding site, showed decreased accumulation of tetracycline. These results suggest that tetracycline resistance is multifactorial, involving alterations both in ribosomal binding and in membrane permeability.

The enhancement of nuclear receptor transcriptional activation by a mouse actin-binding protein, alpha actinin 2

The p160 coactivators, steroid receptor coactivator 1, glucocorticoid receptor interacting protein 1 (GRIP1) and the activator of thyroid and retinoic acid receptor, have two activation domains, AD1 and AD2, which transmit the activation signal from the DNA-bound nuclear receptor to the chromatin and/or transcription machinery. In screening for mammalian proteins that bind the AD2 of GRIP1, we identified a mouse actin-binding protein, alpha actinin 2 (mACTN2). mACTN2 was expressed in the heart, skeletal muscle, lung, brain and testis, but there was no expression in the spleen, liver or kidney. Interestingly, the expression level of mACTN2 in the developing embryo depended on the embryonic stage. We further demonstrated that mACTN2 could enhance two transactivation activities of GRIP1, which in turn could enhance the homodimerization of mACTN2. Importantly, mACTN2 not only served as a primary coactivator for androgen receptor, estrogen receptor and thyroid receptor activities, but also acted synergistically with GRIP1 to enhance these nuclear receptor (NR) functions. However, the NR binding motif, LXXLL, conserved in mACTN2 and other actinin family proteins, might be a dispensable domain for its coactivator roles in NRs. These findings suggested that mACTN2 might play an important role in GRIP1-induced NR coactivator functions.

Factors affecting the isotopic composition of organic matter. (1) Carbon isotopic composition of terrestrial plant materials

The stable isotope composition of the light elements (i.e., H, C, N, O and S) of organic samples varies significantly and, for C, is also unique and distinct from that of inorganic carbon. This is the result of (1) the isotope composition of reactants, (2) the nature of the reactions leading to formation and post-formational modification of the samples, (3) the environmental conditions under which the reactions took place, and (4) the relative concentration of the reactants compared to that of the products (i.e., [products]/[reactants] ratio). This article will examine the carbon isotope composition of terrestrial plant materials and its relationship with the above factors. delta13C(PDB) values of terrestrial plants range approximately from -8 to -38%, inclusive of C3-plants (-22 to -38%), C4-plants (-8 to -15%) and CAM-plants (-13 to -30%). Thus, the delta13C(PDB) values largely reflect the photosynthesis pathways of a plant as well as the genetics (i.e., species difference), delta13C(PDB) values of source CO2, relevant humidity, CO2/O2 ratios, wind and light intensity etc. Significant variations in these values also exist among different tissues, different portions of a tissue and different compounds. This is mainly a consequence of metabolic reactions. Animals mainly inherit the delta13C(PDB) values of the foods they consume; therefore, their delta13C(PDB) values are similar. The delta13C(PDB) values of plant materials, thus, contain information regarding the inner workings of the plants, the environmental conditions under which they grow, the delta13C(PDB) values of CO2 sources etc., and are unique. Furthermore, this uniqueness is passed on to their derivative matter, such as animals, humus etc. Hence, they are very powerful tools in many areas of research, including the ecological and environmental sciences.

Diagnosis of Helicobacter pylori infection by stool antigen test in southern Taiwan

Helicobacter pylori (H. pylori) has been found to be associated with various gastrointestinal diseases. Confirmation of H. pylori infection includes invasive and non-invasive methods. There has been increasing interest in noninvasive tests recently. However, the geographical differences among H. pylori strains have been emphasized recently and the H. pylori strain in Taiwan showed a high cagA positive result and different vacA subtype when compared with those of Western countries. The aim of this study is to access and compare the reliability and the diagnostic accuracy of the stool H. pylori antigen tests by spectrophotometry and by the visual method, especially in Southern Taiwan. Thirty-two patients (18 men and 14 women; age range: 23-91 y/o, mean: 50.5 y/o) who underwent gastroendoscopy at Kaohsiung Medical University Hospital were enrolled in this study. H. pylori infection status was confirmed by culture or two positive test results on CLO test, histology and 13C-urea breath test (13C-UBT). The exclusion criteria included previous gastrointestinal tract surgery, use of antibiotics, proton pump inhibitor or compounds containing bismuth within 1 month of the study. Among them, 14 patients were with duodenal ulcer (DU), 4 with gastric ulcer (GU), 12 with non-ulcer dyspepsia, and 2 with GU and DU. Those patients had their stool collected for ELISA tests of H. pylori stool antigen (HpSA). The HpSA tests were positive in 16 of 18 patients diagnosed as H. pylori positive, and negative in 13 of 14 patients as H. pylori negative. The sensitivity and specificity were 88.9% and 92.9% respectively. The positive and negative predictive values were 94.1% and 86.7% respectively. The concordance of HpSA accessed by spectrophotometry and visual method is 100%, which makes this test even easier and cheaper. We concluded that stool HpSA test is a noninvasive, accurate, reliable, rapid and easy way to diagnose H. pylori infection in Southern Taiwan, either by spectrophotometry or by visual assessment.

[Amplification and analysis of T-DNA flanking sequences in transgenic rice]

Rice transformation mediated by Agrobacterium tumefaciens has technically matured to some extent, but the mechanics of T-DNA integration in transgenic rice remains largely unknown. Using thermal asymmetric interlaced PCR (TAIL-PCR), we analyzed the flanking sequences of T-DNAs in transgenic rice plants, in which the resistance gene for rice bacterial blight disease, Xa21, had been integrated stably. Sequence analysis of 24 fragments amplified by TAIL-PCR showed that of them 14 were rice genomic DNA, 9 contained vector backbone sequences, and one was a fragment of the exogenous gene Xa21. The characteristics of the 14 rice genomic DNA sequences at T-DNA integrated sites are significantly different from those of the reported rice genomic sequences into which exogenous genes were integrated through direct DNA transformation methods. T-DNA border sequences integrated in rice genome have similar features as those integrated in dicotyledonous genomes. In the backbone containing flanking sequences (37.5%, 9/24) vector backbones appeared in different types.

Evaluation of an office-based urine test for detecting Helicobacter pylori: a Prospective Pilot Study

BACKGROUND/AIMS

To ascertain the reliability of a newly developed office-based urine test, the RAPIRUN test, used for detection of H. pylori infection.

METHODOLOGY

Urine specimens from 142 consecutive patients undergoing gastroendoscopy (77 men, 65 women; mean 52.0 years) were tested with RAPIRUN at the same time. The total reaction time for the urine test is 20 min. None of the patients had received any H. pylori eradicating treatment. The H. pylori status was evaluated based on 5 different tests: culture, histology, biopsy urease test, 13C-urea breath test, and the RAPIRUN test. A commercial office-based kit using an immunochromatographic technique was used to examine urine samples for H. pylori antibody. H. pylori status was defined as positive when the culture was positive or if 2 of the other 3 tests (histology, biopsy urease test, and 13C-urea breath test were positive.

RESULTS

Of 93 patients with H. pylori infection, 88 were tested as positive by RAPIRUN (sensitivity 94.6%). Of 48 patients without infection, 43 were found to be negative by RAPIRUN (specificity 89.6%). One case with an invalid urine test was excluded.

CONCLUSIONS

This urine test is a rapid, inexpensive, reliable and easy-to-use tool for the diagnosis of H. pylori infection in untreated patients. It can be used for mass screening of patients' H. pylori status, particularly in children, postgastrectomy patients, uncooperative patients, and patients undergoing bismuth or proton pump inhibitor treatment.

[Construction of a bacterial artificial chromosome (BAC) contig encompassing the bacterial blight resistance gene Xa4 locus in rice]

The gene Xa4 confers dominantly resistance to rice bacterial blight, which has been finely mapped between RFLP markers G181 and L1044, and co-segregated with the resistance gene homologues sequence marker RS13. The three markers were used to screen a rice Bacterial Artificial Chromosome (BAC) library constructed from IRBB56, a Xa4-harborring indica variety, resulting in the detection of totally 128 positive clones. Of the 18 positive clones picked out by RS13, 4 and 6 clones were simultaneously detected by G181 and L1044, respectively. Based on their HindIII restriction patterns, 12 clones were selected out to construct a contig that spanned about 420 kb covering the Xa4 locus, which is a solid base for the isolation of Xa4 gene.

An efficient method for the culture of Helicobacter pylori from gastric biopsies with two-section petri dishes

PURPOSE

Helicobacter pylori is the principal cause of chronic gastritis and is strongly associated with peptic ulcer disease and gastric cancer, as well as with gastric lymphoma (mucosa-associated lymphoid tissue [MALT] type). H. pylori could be recovered by many kinds of media, however, it could not be detected efficiently. This study was trying to ameliorate the isolation and detection rate with selective and non-selective media.

METHODS

First, type strain (ATCC 43504) was cultured with twelve different kinds of sheep blood agar based on brain heart infusion medium for five days. Then five better non-selective media and five selective media were chosen for the biopsy, which were incubated at 37 degrees C in a microaerophilic incubator for five days. Endoscopic biopsies were collected from 623 patients at Kaohsiung Medical University Hospital.

RESULTS

It was found that non-selective media, which contain 5% modified chocolate agar (the ratio of fresh and heated sheep blood is 2) with 1% Isovitalex, had the best detection rate (91.1 +/- 0.6)%. Furthermore, 5% modified chocolate agar with 1% Isovitalex and 1% antibiotics would increase the detection rate to (97.1 +/- 0.3)%.

CONCLUSIONS

According to Ansorg's method, the best detection rate (98.4 +/- 0.7)% could be obtained with two-section petri dishes which had 5% modified chocolate agar with antibiotics and the other without antibiotics.

[Construction of a deep coverage rice BAC library and identification of clones associated with disease-resistant genes]

A BAC library for IRBB56, an accession pyramiding Xa4, xa5 and xa13 three bacterial blight resistance genes, was constructed. The library contains 55,296 clones with an average insert size of 132 kb. Based on a haploid genome size of 450 Mb, the coverage of the library was about 14 genome equivalents that make it one of the most comprehensive BAC libraries available in rice and provide 99.99% possibility to isolate any interested rice genes or sequences in the library. To determine the representation of organelle DNA homologues in the library, the library was screened with three different chloroplast genes and four mitochondrial genes, respectively. Results from this screening showed that less than 1% of clones in the library contain organelle genomic DNA homologues. Then, DNA markers on three different chromosomes linked to Xa4, xa5, and xa13, and a PCR fragment of rice UROD gene, were used to screen the library resulting in a range of 11-106 hits that will promote the isolation of these genes. The deep coverage and the large insert size of the library will facilitate physical mapping, isolation, and cloning of rice genes.

Simplified 13C-urea breath test for the diagnosis of Helicobacter pylori infection--the availability of without fasting and without test meal

The conventional 13C-urea breath test (13C-UBT) for detecting Helicobacter pylori infection was performed during fasting state and with a test meal to delay gastric emptying during the test. For the convenience of propagating this test, we assessed the availability of non-fast and without test meal in 13C-UBT for the diagnosis of H. pylori infection. One hundred and five consecutive patients who received endoscopic examination were studied. All of them received endoscopic biopsy for urease test, culture and histopathology to determine whether there was a presence of H. pylori infection. Each patient received four separate 13C-UBT under the following four testing conditions. Test I) fasting state with test meal (100 ml fresh milk), Test II) non-fast (taking usual food) but with test meal, Test III) fasting state without test meal, and Test IV) non-fast and without test meal. The excess delta 13CO2 values were calculated via the breathed samples that were collected at 15 minutes after ingestion of 13C-urea. There were 61 H. pylori positive and 44 negative patients in this study, with an excess delta 13CO2 values 3.0, 4.0, 3.5 and 4.0 as a cut-off value in the four tests respectively, according to the ROC curve. The results of test I, a conventional procedure, had a good correlation with the gold standard. The sensitivity and specificity were 100% and 95% respectively. The alternative procedures in other tests also have high sensitivity and specificity at 15-minute detecting time. The sensitivity of the tests II, III and IV at 15-minute detecting times were 98%, 98% and 100%, and the specificities of those were 95%, 98% and 95% respectively. We therefore suggest that fasting and test meal possibly be omitted when the cut-off value is 4.0 per mil in the simplified 13C-UBT (non-fast and without test meal, and detection at 15 minutes after ingestion of 13C-urea) which is a simple and available procedure for clinical diagnosis of H. pylori infection.

[Integration of the genetic map and the physical map of the subterminal region on the longer arm of rice chromosome 6]

The region between RFLP markers G342 and R1167 was the subterminal part of the longer arm on the rice chromosome 6, because Shen et al. (1998) mapped two telomeric repeat associated sequences distal to G342. In order to integrate the genetic map and the physical map of the region, G342 and R1167 were firstly used to screen BAC library. Based on the positive clones detected by the two markers and chromosome walking by using the outer most insert-end of the overlapping clones, a contig containing 16 BAC clones which spanned 500 kb was constructed. All the insert-ends of the BAC clones could be amplified with thermal asymmetric interlaced PCR. Fourteen insert-ends were subcloned. Seven of them were identified as a single or low copy sequences and five were mapped on the expected sites flanking G342 or R1167. The insert fragment isolated from the minimum tile BAC clones of the contig was used to screen a cDNA library and four different positive clones were detected.

The association between Helicobacter pylori infection and functional dyspepsia in patients with irritable bowel syndrome

OBJECTIVE

Irritable bowel syndrome (IBS) is associated with an exaggerated response to a variety of physiological and nonphysiological gastrointestinal stimuli. Many patients with IBS also have functional dyspepsia. Our aim was to examine the hypothesis that Helicobacter pylori (H. pylori) infection may predispose IBS patients to functional dyspepsia.

METHODS

In 69 IBS patients, dyspeptic symptoms, H. pylori status, and sociodemographic and psychological variables (perceived stress, trait anxiety, and depression) were assessed. Sociodemographic and psychological variables were also evaluated in 52 control subjects.

RESULTS

Mean scores for perceived stress (17.1 +/- 6.0 vs 14.9 +/- 6.0, p = 0.05), trait anxiety (45.6 +/- 9.1 vs 41.1 +/- 7.8, p = 0.004) and depression (9.9 +/- 8.4 vs 5.0 +/- 5.5, p = 0.0002) were higher in IBS patients than in controls. In all, 33 of the 69 patients (47.8%) had H. pylori infection, and this was associated with relevant symptoms of epigastric pain (odds ratio [OR] = 6.77, 95% confidence interval [CI] 1.89-24.3) and postprandial upper abdominal fullness (OR = 4.23, 95% CI 1.38-13.2). H. pylori infection and female gender were independent predictors of the presence of relevant dyspepsia (OR = 8.31, 95% CI 2.35-29.5 and 6.06, 95% CI 1.71-21.5, respectively). Symptom intensity was associated with the level of perceived stress (total relevant symptom number > or =3 vs <3, OR = 1.16 per point on a 40-point perceived stress scale, 95% CI 1.01-1.34).

CONCLUSIONS

In IBS patients, the presence of dyspepsia is associated with H. pylori infection, female gender, and perceived stress.

[Molecular tagging of a new recessive gene for late heading in a rice cultivar 8987]

8987 is a late flowering (lf) indica cultivar. In this study, genetic analysis for lf was carried out in the crosses between 8987 and four varieties with different heading time. Inheritance of lf in F1 plants and F2 populations clearly revealed that the lf of 8987 is controlled by one recessive gene. Bulked-segregant method and cosegregation analysis in F2 population were used to screen molecular markers, which were linked with lf gene. The results showed that the lf gene was mapped between the two RFLP marker C213 and RG404 on chromosome 7. The tagged gene will be utilized in molecular marker assisted selection in the future rice breeding program for new varieties.

[Introduction of wide spectrum rice bacterial blight resistance gene Xa21 into two-line genic male sterile rice variety Pei'ai 64S]

Agrobacterium-mediated transformation of two-line genic male sterile Indica rice variety Pei'ai 64S was conducted using a cloned gene, Xa21, as the foreign gene and mature embryo calli as the recipients. A total of 46 transgenic plants had been obtained. The PCR analysis and Southern blotting showed the integration of Xa21 gene into the genome the transgenic plants. Results of inoculation with philippine race 6 of Xanthomonas oryzae pv. oryzae indicated that most of transgenic plants obtained high resistance to rice bacterial blight disease (Xoo). Analyses of T1 plants of the tested transgenic lines showed that integrated Xa21 gene could be steadily inherited and segregated in a 3:1 ratio.

Endoscopic hydrogen peroxide spray may facilitate localization of the bleeding site in acute upper gastrointestinal bleeding

BACKGROUND AND STUDY AIMS

A major problem encountered in the emergency endoscopic management of acute upper gastrointestinal (UGI) bleeding is poor localization of the bleeding site, which can be obscured by blood or clots. Traditional attempts to overcome this problem have been by physical methods, which have usually proved unsatisfactory. The aim of this prospective study was to show that hydrogen peroxide can be used as a dissolution agent, resulting in an alteration of the characteristics of blood clots and allowing a clearer visual field.

PATIENTS AND METHODS

Twenty patients with acute UGI bleeding (13 male, seven female) were included in the study. The suspected site of bleeding was initially sprayed with 200 ml of saline and then with 25-175 ml of 3 % H2O2. Pictures of the visual field were taken before and after irrigation with both saline and H2O2. These pictures were evaluated by three gastroenterologists and scored using the following visual clearance scoring system: -3, marked worsening of visual field; -2, moderate worsening; -1, slight worsening; 0, no change; +1, slight improvement; +2, moderate improvement; + 3, marked improvement. In cases of active oozing or spurting, after initial hemostasis was achieved the bleeding point was injected with pure ethanol or cauterized with a heater probe. In order to assess the safety of 3 % H2O2 endoscopic biopsies of the antrum and the duodenal bulb were performed before and 30 minutes after its use and examined by a pathologist.

RESULTS

There was a significant improvement in the mean visual clearance score after irrigation with H2O2 compared to irrigation with saline alone (2.13 vs. 0.43, P<0.001). During endoscopic examination there were 19 patients with active oozing from the ulcer base covered by an adherent blood clot; 12 of these (63.1%) achieved initial hemostasis after H2O2 spraying. Eleven of 18 (61.1 %) patients complained of a mild epigastric burning sensation during H2O2 irrigation. There was no clinically significant change in the histology of the antrum and the duodenal bulb after H2O2 therapy.

CONCLUSIONS

We concluded that H2O2 is a safe and effective way to clear the visual field, facilitating the localization of the bleeding site during emergency endoscopy for acute UGI bleeding, with only mild side effects. In some cases H2O2 therapy can also induce temporary hemostasis. We recommended the use of hydrogen peroxide to improve endoscopic visualization, especially in cases where an adherent blood clot covers the suspected bleeding site.

The hemodynamic changes of gastroduodenal regional blood flow after Helicobacter pylori eradication in patients with duodenal ulcer scar

Duodenal ulcer (DU) is frequently accompanied by Helicobacter pylori (Hp) infection and associated with the imbalance of aggressive factors and defensive factors. To investigate the possible relationship between Hp and regional gastric blood flow, 26 endoscopically proved DU (scar stage) and Hp infection patients were included and received triple therapy (colloid bismuth subcitrate 120 mg qid for 4 weeks, amoxicillin 500 mg qid for 2 weeks and metronidazole 250 mg tid for 2 weeks). Regional gastroduodenal blood flow (RGDF) was measured at DU scar area and antrum lesser curvature site by laser Doppler flowmetry during endoscopic examination, before and one month after triple therapy. In 22 patients with Hp eradication the RGDF was significantly elevated at antrum lesser site after triple therapy (p < 0.05) but there was no difference at DU scar area. However, in 4 patients without Hp eradication no difference of RGDF in these two points was found. Therefore, Hp appears to have direct effects on gastric microcirculation.

Quantification of Helicobacter pylori infection: Simple and rapid 13C-urea breath test in Taiwan

The 13C-urea breath test (13C-UBT) is a non-invasive method for detecting Helicobacter pylori. This study was performed to determine the cutoff value and evaluate the sensitivity and specificity of 13C-UBT in Taiwan. 13C-Urea (100 mg of 99% 13C-labeled urea) was dissolved in 50 ml sterile water for the test. The test meal for delaying gastric emptying was 100 ml fresh milk. Patients fasted for at least 6h. A baseline breath sample was collected 5 min after they had the test meal. Two other samples were collected at 15 and 30 min after the patients ingested the 13C-urea. The test was evaluated in 352 patients after routine upper gastrointestinal endoscopy, and the urease test, culture, and histopathology were taken as the gold standards for detecting H. pylori. According to the receiver operating characteristic (ROC) curves, we chose values of 2.8 and 4.2 excess delta 13CO2 per mil as the cut-off values for 15 and 30 min, respectively, post 13C-urea. The sensitivity and specificity of 13C-UBT were 99% and 93% at 15 min, and 98% and 93% at 30 min post 13C-urea, respectively. The 13C-UBT breath test is an efficient non-invasive method of high sensitivity and high specificity for detecting H. pylori infection. We suggest that the use of fresh milk as the test meal and the detection of excess delta 13CO2 15 min after the ingestion of 13C-urea are suitable for the clinical use of 13C-UBT. This test is simple and rapid.

Vasopressin-induced amber-like skin necrosis

Case reports about vasopressin-induced cutaneous necrosis are not frequent. Here we report a further case, of which skin manifestations included not only mottling, cyanosis, ecchymosis, bullae and gangrene, but also amber-like change in focal areas. Besides, intermittent paling of the skin with or without deep pain sensation of the limbs over non-injection sites was observed that might be a warning sign of impending skin necrosis. Based on the literature about vasopressin-induced skin necrosis we discuss the possible role of coagulation enhancement of this molecule.

[Study of color scale B-ultrasonography in syndrome differentiation of biliary tract diseases]

OBJECTIVE

To evaluate the relationship between modern medical detective method of imaging and Syndrome Differentiation of TCM.

METHODS

Two hundred and sixteen biliary tract diseases patients were observed with color scale B-ultrasonography and fat meal tests.

RESULTS

Eighty-four cases (38.89%) of damp-heat type in the Liver-gallbladder among the 216 patients had widened gallbladder, higher tension and weak bile echo-penetration through, 39 cases (18.06%) of type of Liver-Qi stagnation and Spleen deficiency had small transection, hypotension, slender type and low contraction rate, 13 cases (6.02%) of Blood-stasis type had small gallbladder volume and the contraction rate decrease significantly. There were 71 cases (32.87%) of Liver-Qi stagnation type and 9 cases (4.17%) of Liver Yin-Deficiency type, whose characters of the gallbladder were not prominent, so the identification of these cases depended largely on clinical differentiation.

CONCLUSIONS

This study will facilitate the further extending the principle of inspection in the specific organs which may provide us with the objective basis for the differentiation of biliary tract diseases.

Clinicopathologic study of gastric carcinoma with duodenal invasion

Clinicopathologic features of 319 patients who underwent gastrectomy for adenocarcinoma of stomach were studied whether disease involved duodenum or not. Thirty-eight patients (11.9%) had duodenum invasion. Gastric carcinoma with duodenal invasion was most often Borrmann III or Borrmann IV (65.8%) type, with pylorous invasion by endoscopy (39.5%), large tumor size (73.7% > or = 5cm), lymph node metastasis (78.9%), serosal invasion (97.4%) and the incidence of the resection line not being free was high (13.2%). Duodenal invasion was most often (55.3%) direct through the deep layer or through lymphatics or venules. We need to pay more attention to finding duodenum invasion. More than 3 cm width of duodenal resection is recommended if duodenum invasion is suspected.

High seroprevalence of IgG against Helicobacter pylori among endoscopists in Taiwan

A prospective survey to investigate the seroprevalence of IgG against Helicobacter pylori among endoscopists in Taiwan was conducted by analyzing blood samples of 70 study subjects and 64 nonendoscopist physicians with quantitative ELISA. Personal information and the practices of infection control related to gastroscopy examination were obtained by a self-administered questionnaire. Significant differences were detected in the IgG prevalence between study and control subjects (80.0% vs 51.6%; P < 0.05). The serum level of antibody in endoscopists (385.2 +/- 36.1 unit/ml) was significantly higher than that of nonedoscopists (211.8 +/- 33.0 unit/ml; P = 0.018). Endoscopists performing 30 or more sessions of gastroscopy per week had higher seroprevalence than those performing less than 30 sessions (90.9% vs 70.3%; P = 0.0126). In conclusion, endoscopists in Taiwan had a high prevalence of H. pylori infection. The cause might be related to the frequency of gastroscopies performed.

Utility of brushing cytology in the diagnosis of Helicobacter pylori infection

OBJECTIVE

We performed brushing cytology during routine gastroendoscopic examinations to evaluate the utility of gastric brushing cytology in the diagnosis of Helicobacter pylori infection.

STUDY DESIGN

The brushing cytology materials were obtained from the antrum of the stomach in 107 patients. The urea breath test, biopsy urease test and histology with hematoxylineosin staining were also performed on each patient. We then compared the results of brushing cytology with those of the three other tests (13C urea breath test, biopsy urease test, histology).

RESULTS

Fifty-nine of 103 patients (57%) were diagnosed as positive for H pylori organisms using brushing cytology. Using positive or negative results from any two of the other three tests as the gold standard, a true positive result was found in 57 cases, a true negative in 43 cases, a false positive in 2 cases and a false negative in 1 case. The sensitivity and specificity of brushing cytology were 98% and 96%, respectively.

CONCLUSION

Gastric brushing cytology provides an accurate, inexpensive and easy technique in the rapid detection of H pylori infection. Brushing cytology also has the advantage of being applicable to diagnostic endoscopy without waiting days for results.

Computed tomography, endoscopic ultrasonography and intraoperative assessment in TN staging of gastric carcinoma

In a prospective study from November 1989 to December 1993, the accuracy of computed tomography (CT), endoscopic ultrasonography (EUS) and intraoperative surgical assessment were compared for the evaluation of the depth of invasion (T category) and involvement of lymph nodes (N category) in patients with gastric carcinoma. Sixty-nine consecutive patients who received preoperative CT and EUS underwent subsequent surgery. CT and EUS results were compared with histopathologic staging of tumor invasion depth and regional lymph node metastasis (pT and pN categories). T categories were staged correctly in 42% of the cases by CT, 71% by EUS and 55% by intraoperative surgical assessment. CT correctly staged 49% of N1 and N2 lymph nodes compared with 65% for EUS and 45% for intraoperative surgical assessment. CT was more accurate for advanced cancer but had a tendency to understage the T and N categories. EUS was more accurate for serosal cancer and displayed a tendency to overstage T categories and understage N categories. Intraoperative surgical assessment overstaged early T stages, understaged the T4 stage and had a tendency to overstage N categories. CT and intraoperative surgical assessment of T and N categories were of limited value in the staging of gastric carcinoma compared to EUS. EUS is a valuable form of assessment to evaluate gastric cancer staging before surgery.

Evaluation of the severity of Helicobacter pylori infection with urease test: its correlation with histopathology and bacterial density

In 69 patients, the severity of Helicobactor pylori (H. pylori) infection was evaluated by bacterial density of tissue implants and inflammatory responses by histology. The specimens were taken from gastric angle and antrum (greater and lesser curvature sides) by gastroduodenal endoscopy. In urease test, the severity was measured in 3 grades according to color change of the agar: those change are within 30 minutes (grade 3), 30 minutes to 3 hours (grade 2), and 3 to 6 hours (grade 1), respectively; while the grade 0 indicated no color change occurring 6 hours after tissue inoculation. The severity of infection was assessed according to the bacterial density under high power microscopic fields (Gram's stain). Grade 0 indicated no bacterium seen; grade 1, only 1 to 10 bacteria at all fields; grade 2, 1 to 3 bacteria in each high power field; and grade 3 was 4 bacteria or more on average in each high power field. The degree of inflammatory response was evaluated by inflammatory cell infiltration (H & E stain) and classified into grade 0, 1 and 2, which indicated the inflammatory cell infiltration below 50%, between 50% and 75%, and above 75%, respectively. There are no positive relationships among urease test reaction time, bacterial density grading and degrees of inflammatory cell infiltration. Clinically, the reaction time of urease test cannot reflect the severity of H. pylori infection semi-quantitatively, either in terms of bacterial density or cellular inflammatory response.

Digital Gap Monitor and Adaptive Integral Control for Auto-Jumping in EDM

This paper reports a monitoring and adaptive integral control strategy for EDM to regulate the cycle time of the periodical retraction (jumping) of the tool electrode according to the gap condition. A digital EDM gap monitor has been developed to detect the time ratios of gap states with a resolution of 0.2 μs. The theoretical and experimental analysis of the effect of sensing parameter combinations on control aspects and performance of manual setting, integral control and adaptive integral control methods have been carried out. Experimental verification shows that the proposed system results in higher erosion rate, better machining stability, and complete avoidance of arc damage.

Does Helicobacter pylori infection play a role in the pathogenesis of non-ulcer dyspepsia--a study of gastric emptying time

To investigate the relationship between gastric motility and Helicobacter pylori infection in patients with non-ulcer dyspepsia, 28 patients and 10 asymptomatic healthy persons underwent gastroduodenal endoscope examinations and scintigraphic test of solid phase gastric emptying time using Chinese fried rice as a test meal. Clinical symptoms were also recorded using questionnaires for scoring. Half emptying times for ingested food (t1/2) between H. pylori infected (190.86 +/- 112.53 minutes) and uninfected patients (227.69 +/- 179.29 minutes) were not different statistically. Seven of the 15 patients with H. pylori infection (46.6%) had delayed gastric emptying time (t1/2 > 197.7 minutes), compared to 4 out of 13 without infection (30.07%) (p > 0.05). There was also no association between the status of H. pylori infection and severity of clinical symptoms (total symptoms scores: H. pylori positive: 10.07 +/- 3.84; H. pylori negative: 7.62 +/- 2.25) (p > 0.05). Seven patients from whom H. pylori was found to have been eradicated using triple therapy (colloid bismuth subcitrate 120 mg q i d, tetracycline 500 mg q i d and metronidazole 250 mg q i d for 14 days) did not show significant changes in gastric emptying time (before: 171.14 +/- 128.13; after: 158.57 +/- 182.49 minutes) but showed improvement in total symptoms scores (before: 9.28 +/- 3.85; after: 3.85 +/- 4.22) (p = 0.0277).

CONCLUSIONS

infection by H. pylori in patients with non-ulcer dyspepsia did not influence solid phase of gastric emptying time and was not associated with clinical symptoms. Eradication of H. pylori infection relieved the clinical symptoms of the patients with non-ulcer dyspepsia.(ABSTRACT TRUNCATED AT 250 WORDS)

Long-term follow-up and serological study after triple therapy of Helicobacter pylori-associated duodenal ulcer

OBJECTIVE

The purpose of this study was to monitor the change of IgG antibodies to Helicobacter pylori during the course of a long-term follow-up after the eradication of H. pylori, as well as to evaluate the efficacy of triple therapy in preventing the recurrence of duodenal ulcer (DU).

METHODS

Twenty-three DU patients with positive H. pylori were studied; among those patients, 20 ulcers healed after initial treatment of triple therapy. Each patient received a follow-up endoscopy and biopsy examination every 3 months for 1 yr, or whenever the ulcer symptoms recurred. Serological tests for IgG antibodies were performed with a commercial ELISA.

RESULTS

Of the 20 patients with healed ulcers, one dropped out of this study; the recurrence rate of DU at 1 yr was 5% (1/19). There was no recurrence of ulcer in 17 H. pylori-negative patients and only one recurrence out of two H. pylori-positive patients. After the eradication of H. pylori, the seroconversion rates of IgG were 5%, 21%, 42%, 76%, and 94% at 0, 3, 6, 9, and 12 months, respectively. After 6 months, 95% (18/19) of the patients in which H. pylori was eradicated had at least a one-grade fall in IgG titers (p < 0.001). One patient had a relapse of H. pylori which was accompanied with re-elevating IgG titers.

CONCLUSIONS

We conclude that seroconversion, which usually occurs after 1 yr, indicates complete eradication of H. pylori. Furthermore, we suggest that the success of the eradication of H. pylori can be judged without endoscopic examination, 8 months after treatment by triple therapy, according to the fall of IgG titers or seroconversion. Re-elevating IgG titers may be a warning of the possibility of relapse or reinfection of H. pylori.

Active optical feedback in a dual-diode laser configuration applied to displacement measurements with a wide dynamic range

The principles, experimental apparatus, and advantages of the use of an optical feedback technique for extended displacement measurements based on the use of a dual-diode laser configuration are described. This device is capable of creating a synthetic wavelength from the two lasers simultaneously through the frequency selectivity of the individual lasers, which respond only to their own wavelength. Theoretical analysis and experimental evidence are presented to show the feasibility of the measurement method and the simplicity of its operation.

Reappraisal of gastroduodenal lesions after transcatheter arterial chemoembolization of liver neoplasms--selective versus superselective method

Twenty-six patients with liver neoplasm receiving transcatheter arterial chemoembolization (TAE) therapy underwent gastroduodenal endoscopic examinations before and after TAE. The balloon was inflated in the common hepatic artery before chemoembolization if superselective cannulation beyond the gastroduodenal artery could not be done. Sixteen of the 26 patients (61.5%) showed new gastroduodenal lesions, with superficial gastritis in six, one or more erosions in nine, and hemorrhagic gastritis in five. The frequency of lesions detected was no different when the common hepatic artery was obstructed (60.0%) than when superselective embolization was done in more peripheral branch(es) (60.0%). No clinical events indicating upper gastrointestinal bleeding were noticed after TAE. The presence of esophageal and/or gastric varices and session(s) of TAE performed before did not affect the occurrence of gastroduodenal lesion(s). We conclude that TAE produces erosive gastroduodenal lesions that are detected by endoscopic examination but are clinically unimportant; balloon catheter occlusion of the common hepatic artery did not result in more frequent gastroduodenal complications than the ordinary superselective chemoembolization method.

Percutaneous transluminal excimer laser coronary angioplasty. Clinical report of six cases

Six patients with 95% to 100% occluded atherosclerotic lesions underwent percutaneous transluminal excimer laser coronary angioplasty (PTELCA). Among them, 5 were male and 1 was female; their age ranged from 28 to 66 years. Four patients had LAD stenosis and 2 LCX lesions. Acute angiographic and clinical success was achieved in all patients but one, with a success rate of 83.3%. It was demonstrated that PTELCA is a safe and effective therapy for selected patients with coronary artery disease.

Eradication of Helicobacter pylori infection and the recurrence of duodenal ulcers

The purpose of this study was to compare the performance of different regimens on Helicobacter pylori (H. pylori) eradication and duodenal ulcer recurrence. During a four-week period, 59 patients with duodenal ulcers who were positive for H. pylori infection were randomly treated with one of three regimens. Seventeen patients were treated with ranitidine, 19 with colloidal bismuth subcitrate (CBS), and 23 with triple therapy (CBS, tetracycline and metronidazole). Forty-six patients with healed ulcers after treatment received follow-up for six months without maintenance therapy. The recurrence rates of duodenal ulcers confirmed by endoscopy in these three groups were 64%, 33% and 0% at the third month, and 73%, 67% and 5% at the sixth month, respectively. In the ranitidine therapy group, H. pylori infection was still present at the final follow-up. In the CBS therapy group, H. pylori was suppressed initially, but recurred in all cases. In the triple therapy group, there was only one case in which H. pylori infection persisted and where ulcer recurrence occurred after 3.5 months. The remaining cases were all H. pylori negative and had no recurrence of duodenal ulcers during the six months of follow-up. Overall, 19/27 (70%) patients positive for H. pylori had a recurrence of duodenal ulcers, while none of the 19 patients who were negative for H. pylori had a recurrence of ulcers at the sixth month. This study shows that triple therapy is more effective than the other two regimens in the eradication of H. pylori and in reducing the recurrence of ulcers. H. pylori may play a role in the recurrence of the duodenal ulcer.

[Experimental observation of high portal venous resistance in dogs]

To study the relationship between portal resistance and formation of portal hypertension, we designed a high portal systemic resistance model by injecting bletilla hyacinthina into the intrahepatic portal venulae through the portal vein in 9 dogs. The portal pressure was measured and the portal hemodynamics studied by ultrasonic Doppler before operation, and the data were collected with re-laparotomy after 10, 20 days respectively. Liver function, portal collateral circulation and liver histology were also observed. Our results suggest that the portal high resistance could cause portal hypertension. The elevation of FPP was maintained and portal blood flow was increased constantly in different degrees. The veins of the abdominal wall and esophagus were dilated slightly. Histological study of the liver showed fibrotic hyperplasia in the portal area. Liver function was not markedly changed except elevation of ALP. It seems that the combination of portal resistance and portal hyperdynamics are the necessary pathogenic factor of formation of portal hypertension.

Self-mixing interference in a diode laser: experimental observations and theoretical analysis

The experimental results of an investigation of self-mixing effects or backscatter modulation in diode lasers coupled with a simple theoretical analysis are presented. The laser is used to send light, either in free space or through an optical fiber, to a movable target from which the optical backscatter is detected and fed back into the laser. In the experiment three significant conclusions are drawn: (1) self-mixing interference is not dependent on the coherence length of the laser, (2) the interference is not dependent on the use of a single-mode or multimode laser as the source, and (3) the interference is independent of the type of fiber employed, i.e., whether it is single mode or multimode. A comparison of this kind of interference with that in a conventional interferometer shows that self-mixing interference has the same phase sensitivity as that of the conventional arrangement, the modulation depth of the interference is comparable with that of a conventional interferometer, and the direction of the phase movement can be obtained from the interference signal. The above factors have implications for the optical sensing of a wide range of physical parameters. Several applications of the method are discussed that highlight the significant advantages of simplicity, compactness, and robustness as well as the self-aligning and self-detecting abilities of fiber-based self-mixing interferometry when compared with the use of conventional interference methods.

[Flow cytometric analysis of DNA in esophageal cancer]

Malignancy is the first of the ten leading causes of death in Taiwan area, however, since 1978, esophageal cancer is on the first ten causes of malignancy. Esophageal cancer is an aggressive neoplasm with a generally poor prognosis. This is usually related to the advanced stages of the neoplasm at presentation and at diagnosis. In this study, the DNA content in tumor was analyzed by flow cytometry, and compared it with clinical- pathological data, especially the survival time. All thirty seven cases (36 male, 1 female, mean age: 56.5 +/- 10.3 y/o) received operation at Kaohsiung Medical College Hospital in the past 11 years and 29 cases (27 male, 2 female, mean age: 62.2 +/- 9.6 y/o) proved to be esophageal cancer by endoscopic biopsy were assayed in this study. The formalin fixed-paraffin embedded block is used to analyze DNA content by flow cytometry. After comparing these results with clinical-pathological data, there were no significant difference in sex, age, duration, tumor location and length. However, there is a significant correlation between ploidy and tumor cell differentiation, that is, most of the diploid cells were well differentiated while most of the aneuploid cells were poorly differentiated. The median survival time of diploid cases was 325 days which was longer than the 277 days in aneuploid group, but there was no significant difference between these two groups. The same result was noticed in DNA index. Multiple variables analysis of prognostic factors disclosed that there were significant difference in correation with age tumor location tumor length, and whether there was combined radiotherapy and operation. But there were no significant relationship between survival and DNA ploidy DNA index distant metastasis surrounding tissue invasion sex duration and tumor cell differentiation. These data suggest that DNA folw cytometry analysis alone, may not provide a sueful biologic basis for the variable prognosis seen with esophageal tumors.

Comparison of omeprazole and nizatidine in the treatment of duodenal ulcers

This study compares the efficacy and side effects of omeprazole and regular- and double-dose nizatidine in the treatment of duodenal ulcers. Duodenal ulcer healing rates in these three groups (omeprazole, 20 mg qd; nizatidine, 300 mg hs and 600 mg hs) were 81.8%, 19% and 30%, respectively, after two weeks of therapy; and 90.5%, 70% and 84.2%, respectively, after four weeks of treatment. Omeprazole had a significantly better healing rate than nizatidine, 300 mg or 600 mg, after two weeks of treatment (p < 0.01), but not after four weeks of treatment. Omeprazole relieved the ulcer pain sooner than nizatidine (p < 0.05). Smoking decreased the duodenal ulcer healing rate in the omeprazole group, but not in the nizatidine groups. Clinical features, such as sex, age, alcohol consumption, ulcer size, past history of upper gastrointestinal bleeding and duration of peptic ulcer history, did not collate with the healing rate. Patients with double-dose nizatidine did not show any benefits over those with a regular dose in this study. Adverse effects were minor, and there were no significant changes in biochemistry after therapy in these three groups of patients.

Fiber-optic Doppler velocimeter that incorporates active optical feedback from a diode laser

A fiber-optic Doppler velocimeter that incorporates the effect of self-mixing in a diode laser is described. A theoretical model, based on self-mixing interference theory, is presented, and a simple experimental arrangement is constructed. The results of the experimental research are found to be in good agreement with the theoretical analysis. A Doppler velocity of as much as 3 m/s was measured directly, and a good linear relationship between the Doppler velocity and the Doppler-shifted frequency was obtained, which can be used to determine the speed of a moving object.

Evaluation of urease test, gram stain, culture, and histology in the detection of Campylobacter pylori

To evaluate the commonly available tests for detection of Campylobacter pylori infection in the human stomach, we prospectively performed endoscopy and biopsy from the antrum of the stomach in 121 consecutive patients. Four tests, including the urease test, Gram stain, culture, and the hematoxylin and eosin (H & E) stain were used to detect the presence of C. pylori. A C. pylori positive was defined by a positive culture or positive results in two of the other three tests. The sensitivity of the urease test, Gram stain, culture, and H & E stain was 95%, 95%, 71%, and 97%, respectively, and the specificity of those tests was 96%, 100%, 100%, and 73%, respectively. For diagnosis, theoretically, all four tests should be performed from the biopsy specimens. In our experience, the culture was less sensitive, and the H & E stain was less specific, while the urease test and Gram stain were more rapid and had high sensitivity and specificity in the detection of C. pylori infection.

Central nervous system infection after endoscopic injection sclerotherapy

Central nervous system (CNS) infection is a rare complication of endoscopic injection sclerotherapy (EIS) for esophageal varices. We report two patients, one of whom developed a solitary brain abscess, and the other, acute meningitis, after EIS. They presented with high fever initially, and then with changes in mental status. In the case of the solitary brain abscess, the CSF revealed evidence of infection, and CT scan disclosed a brain abscess in the left temporo-parieto-occipital region. This patient received EIS six times and developed the CNS complication 4 wk after the last EIS. There was no growth in either the CSF or the abscess cultures in this case. The other patient with acute meningitis, which developed on the second day after the second session of EIS, had a positive CSF culture of Klebsiella pneumoniae. Both of these patients died despite antibiotic treatment, and craniotomy with drainage in the patient with a brain abscess.

Gastrointestinal tract involvement in hepatocellular carcinoma: clinical, radiological and endoscopic studies

Gastrointestinal tract involvement with hepatocellular carcinoma was observed in 8 out of 396 patients (2%) during the course of the disease. Histological involvement was confirmed in 6 cases. All 8 patients were men. The most common clinical presentation was frank gastrointestinal bleeding, which became evident in all cases. Esophageal varices were not seen in any patient. The sites of involvement were the stomach (3), duodenum (4), and jejunum (1). The median time between the diagnosis of primary tumors and gastrointestinal tract involvement was 4.5 months (range: 0 to 12 months). Hematogenous spread was presumed to have occurred in two patients with diffuse-type hepatocellular carcinoma, one of whom had main portal vein thrombosis. Direct invasion by contiguous neoplasm was the major mode of gastrointestinal tract involvement. This complication is more likely to develop in patients with large, subcapsular, massive type hepatocellular carcinoma treated by transcatheter arterial embolization and/or intra-arterial chemotherapy. The median survival after the diagnosis of gastrointestinal involvement was 1 month (2 weeks-4 months).

Incidence of massive rebleeding from nonbleeding visible vessels in benign gastroduodenal lesions and prospective study in assessing the efficacy of endoscopic hemostasis with local ethanol injection for prevention of rebleeding

Twenty-seven patients presenting with massive upper gastrointestinal bleeding in whom endoscopy revealed nonbleeding visible vessels in benign gastroduodenal lesions were prospectively and nonrandomly allocated to receive endoscopic injection therapy with pure ethanol or conservative treatment. Those who received conservative therapy were used as a control group. The purpose of this study is to evaluate the incidence of massive rebleeding from the nonbleeding visible vessel which was defined by a more rigid criteria and to evaluate the efficacy of endoscopic pure ethanol local injection to prevent rebleeding. Nine out of the 10 (90%) controls had recurrent major bleeding, in contrast to the 2/17 (12%) of those who received hemostatic endoscopy (p less than 0.0002). Pure ethanol local injections also minimized further transfusion requirements (p less than 0.03). The complications of hemostatic endoscopy in this study are negligible. It is concluded that 1) by restrictive definition nonbleeding visible vessels in benign gastroduodenal lesions carry a high potential of recurrent massive bleeding; 2) rebleeding can be safely and effectively prevented by pure ethanol local injection.