Allelopathic Potential of Rice and Identification of Published Allelochemicals by Cloud-Based Metabolomics Platform.

The methanol extracts of nine popular cultivated Vietnamese rice cultivars (Oryza sativa L.cv. OM 2395, 5451, 6976, 380, 5930, 4498, 3536, N406, and 7347) were used to explore their allelopathic potential on barnyardgrass (Echinochola crus-galli L.). At 0.1 g mL-1, OM 5930, OM 4498, and OM 6976 correlatively possessed greatest phytotoxicity on barnyardgrass shoot (98.77%, 90.75%, and 87.17%) and root (99.39%, 92.83%, and 86.56%) growth. The following study aimed to detect previously-known allelochemicals in those rice using XCMS online cloud-based metabolomics platform. Twenty allelochemicals were semi-quantified and seven of them were detected predominantly and five was putatively confirmed in OM 5930 (mg/ 100g fresh rice) as salicylic acid (5.0076), vanillic acid (0.1246), p-coumaric acid (0.1590), 2,4-dimethoxybenzoic acid (0.1045), and cinnamic acid (3.3230). These compounds were active at concentrations greater than 0.5 mM and the average EC50 were 1.24 mM. The results indicated that OM 5930 may use as promising candidates in weed biological control for rice production.

Secondary prophylaxis treatment versus on-demand treatment for patients with severe haemophilia A: comparisons of cost and outcomes in Taiwan.

This study compared secondary prophylaxis treatment with on-demand treatment for severe haemophilia A in Taiwan. Fifty patients from one medical centre were evaluated over a 5-year period. Differences in annual bleed rates and factor VIII (FVIII) utilization were assessed between patients receiving secondary prophylaxis and patients receiving FVIII concentrates on-demand. Results were then used as inputs in a pharmacoeconomic model to predict outcomes of future haemophilia therapy strategies in Taiwan. The median annual number of total bleeding episodes was significantly lower in the 13 (26%) patients who received secondary prophylaxis than in the 37 patients who received FVIII on-demand (7.76 vs. 31.91, P < 0.0001). The between-group difference in median annual factor VIII utilization was statistically significant (1824.41 IU kg(-1) for the prophylaxis group and 1324.81 IU kg(-1) for the on-demand group, P < 0.01). It was estimated that approximately $2 million (USD) per year would be added to the cost of treatment by having all severe haemophilia A patients in Taiwan receive secondary prophylaxis instead of on-demand therapy while 12,566 bleeding will be prevented. It is recommended that National Health Insurance officials utilize these data to evaluate the benefits of enhanced treatment strategies and before making substantial policy changes to haemophilia care in Taiwan.

The 13C-urea breath test to detect Helicobacter pylori infection: a validated simple methodology with 50 mg 13C-urea.

BACKGROUND: Several modifications of the 13C-urea breath test have been published. For reasons of cost efficiency and practicability, the urea dose and measurement duration should be reduced while still maintaining excellent diagnostic accuracy. AIMS: To establish a validated simple protocol for the urea breath test with 50 mg 13C-urea and to compare this protocol with the conventional urea breath test with 100 mg 13C-urea. METHODS: Conventional urea breath test with 100 mg 13C-urea was performed on 152 dyspeptic patients. Full-cream cow's milk was used as the test meal. Breath tests were repeated using 50 mg 13C-urea and the breath samples were collected at baseline and at 10 (protocol t10), 15 (protocol t15) and 30 min (protocol t30). Helicobacter pylori status was assessed by rapid urease test, histology and conventional urea breath test with 100 mg 13C-urea. RESULTS: With protocol t15, the best combination of sensitivity (99.1%), specificity (97.3%) and accuracy (98.7%) was obtained with a cut-off of 2.5 per thousand. There was an extremely high correlation coefficient between the three protocols and conventional 13C-urea breath test (all P < 0.001). CONCLUSIONS: A urea breath test with 50 mg 13C-urea using a simple test meal and a 15-min sampling interval with a low cut-off seems to be cost-effective and convenient. In a well-standardized laboratory, this modification is not associated with any loss of diagnostic accuracy.

Photodynamic action of actinomycin D: an EPR spin trapping study.

Actinomycin D is one of the most widely studied anticancer antibiotic that binds to both double-stranded and single-stranded DNA, and this binding greatly enhances the DNA photosensitization. By use of electron paramagnetic resonance spin trapping techniques, both superoxide radical anion and the radical anion of actinomycin D were identified as important intermediates in the photodynamic process. A mechanism of electron transfer from a DNA base to excited actinomycin D was proposed. These novel findings may shed new light on future application of this drug in photodynamic therapy or cleavage of DNA in unique and controllable ways.

Endoscopic ultrasonography to study the causes of extragastric compression mimicking gastric submucosal tumor.

BACKGROUND AND PURPOSE: Many reports have confirmed that endoscopic ultrasonography (EUS) can differentiate gastric submucosal tumor from extragastric compression, but only a few specifically concentrated on EUS in identifying the causes of external compression. MATERIALS AND METHODS: From May 1993 to May 2001, we used EUS in 238 patients to diagnose gastric submucosal tumor or external compression. We excluded 183 patients who had submucosal tumors and analyzed the remaining 55 patients with extragastric compression. Malignant causes of external compression were proved by surgery or biopsy. Benign causes of external compression were proved by other imaging examinations (abdominal ultrasound, computerized tomography, angiography) or surgery. Patients with external compression caused by normal organs were followed up with repeated upper gastrointestinal endoscopy or EUS. RESULTS: The stomach was compressed by normal extragastric organs in 32 patients (spleen 10, splenic vessel 6, gall bladder 9, liver 3, pancreas 3, and intestine 1), by benign pathologic lesions in 12 patients (liver cyst 7, liver hemagioma 2, splenic cyst 1, pancreatic cyst 1, pancreatic cystadenoma 1) and by malignant tumors in 5 patients (hepatoma 1, liver metastasis from colon cancer 2, pancreatic cystadenocarcinoma 1 and lymphoma of spleen 1). In the remaining six patients, neither submucosal tumor nor external compression was found during EUS examination and the external compression was considered transient. CONCLUSION: When an extragastric compression mimicking submucosal tumor is detected by upper gastrointestinal endoscopy, EUS is indicated to identify the cause of extragastric compression.

Negative CLOtest pellet can be reused.

BACKGROUND: The CLOtest is based on the production of ammonia from urea in the presence of urease. In theory, substrate that has not been consumed in a negative test can be reused. METHODS: We collected negative CLOtest pellets after their first use and stored them at room temperature. Whenever a CLOtest was needed during endoscopy, two biopsy specimens were taken from the antrum. One specimen was tested with a new CLOtest and the other with one that had been used previously. Time to color change was observed in paired tests. RESULTS: We used 216 previously used CLOtest pellets with biopsy specimens obtained from 317 patients. Of the paired tests, 204 matched positive and 108 tested negative. Only 5 paired tests had discrepant results. Three had positive results only with a new CLOtest, and 2 were positive only with the reused test. In positive paired tests, there was significant linear correlation in log-transformed color change time between reused and new tests (p < 0.001). Ninety-two percent of previously used pellets were reused fewer than three times before they yielded a positive color change; the interval to this occurrence ranged from 2 to 15 days. Compared with the new CLOtest, the sensitivity of the reused CLOtest was 98. 6% and the specificity was 98.2%. CONCLUSIONS: A negative CLOtest kept at room temperature can be reused within a short period of time, in circumstances in which there are environmental and economic considerations to be taken into account.

Comparison of invasive and noninvasive tests for detecting Helicobacter pylori infection in bleeding peptic ulcers.

BACKGROUND: Eradication of Helicobacter pylori infection has been shown to prevent recurrent bleeding from peptic ulcers. However, the detection rate for H pylori infection seems to be underestimated in this group of patients and has been scarcely investigated. METHODS: Eighty patients with bleeding peptic ulcer were studied for evidence of H pylori infection. Seventy-seven of these patients were enrolled as having H pylori infection after any one of the following 3 tests were positive: culture, histologic study, or any 2 of rapid urease test (CLO test), carbon 13-labeled urea breath test (UBT), and serologic examination. Fresh blood or blood-containing material in the gastric antrum was noted by panendoscopy in 22 patients (group A). In the remaining 55 cases there was no blood in the antrum (group B). RESULTS: The sensitivities of the CLO test, bacterial culture, histologic study, 13C-labeled UBT, and immunoglobulin G serologic test were 45.5%, 36.4%, 77.2%, 95.4%, and 100% in group A, respectively, and 70.9%, 40.0%, 70.9%, 92.7%, and 96.4%, respectively, in group B. There was a statistically significant difference between the sensitivities found for CLO test and 13C-labeled UBT (p < 0.05). Of these 5 tests, only the sensitivity of the CLO test showed a statistically significant difference between groups A and B (p < 0.05). A delayed positive CLO test result was recorded in 13 patients (3 in group A, 10 in group B). CONCLUSION: Noninvasive tests seemed to be more sensitive than invasive tests in detecting H pylori infection in patients with bleeding peptic ulcers. Blood in the antrum might reduce the sensitivity of the CLO test but have no effect on the other tests. The CLO test should be observed for more than 24 hours because of the possibility of a delayed positive result in some patients with bleeding peptic ulcers.

One-week low-dose triple therapy is effective in treating Helicobacter pylori-infected patients with bleeding peptic ulcers.

Proton pump inhibitor (PPI)-based triple therapy, which combines a PPI and two antibiotics, is highly effective in eradicating Helicobacter pylori infection in peptic ulcer patients, even if given for only 1 week. However, the application of this regimen in patients with bleeding ulcers has not been adequately investigated. We studied the effectiveness of triple therapy in treating 122 patients with proven H. pylori infection, and bleeding stigmata on endoscopy; 97 had duodenal ulcer (DU), 15 had gastric ulcer (GU), and 10 had both types of ulcers. A regimen of omeprazole (20 mg), metronidazole (500 mg), and clarithromycin (250 mg) twice daily was administered for 1 week as soon as the patient could eat normally after bleeding, followed by omeprazole (20 mg) daily for 3 additional weeks. Follow-up endoscopy and 13C-urea breath tests (UBTs) were performed at least 4 weeks after triple therapy. A total of 104 patients completed the study, 83 with DU, 12 with GU, and nine with both. The overall ulcer healing rate was 97.1% and the eradication rate was 91.3%. Patients with and without H. pylori eradication did not differ significantly in terms of age, gender, UBT titer, units of blood transfused, or interval between endoscopy and the beginning of triple therapy. We conclude that 1-week low-dose PPI-based triple therapy is effective in eradicating H. pylori infection in patients with bleeding peptic ulcers. When followed by 3 weeks of additional PPI treatment, a satisfactory ulcer healing rate can also be achieved.