Vietnam Association of Gastroenterology consensus for the diagnosis and treatment of functional dyspepsia.

Abstract: Functional dyspepsia (FD) is a common disorder in clinical practice. It is necessary to rule out physical causes to diagnose this condition. However, the diagnosis is challenging particularly in resource-limited areas. The aim of this consensus is to update international and regional guidelines on the management of FD. The consensus panel included 32 experts from major Vietnamese universities and institutes. This consensus study was conducted using the Delphi method. The grade of recommendation and level of evidence were assessed using the Grading of Recommendations, Assessment, Development, and Evalua-tion system. The consensus level was defined as ≥80% for agreement on the proposed statements. The expert panel approved 14 statements after two rounds of voting, which were related to two sections: (1) diagnostic tests for FD and (2) treatment of FD. This consensus is expected to help physicians in identifying and managing FD appropriately in daily clinical practice and to contribute FD data to Asian regions.

Histopathological features of complete pathological response predict recurrence-free survival following neoadjuvant targeted therapy for metastatic melanoma.

BACKGROUND: Recent clinical trials demonstrated the safety and efficacy of neoadjuvant dabrafenib and trametinib (DT) among patients with surgically resectable clinical stage III BRAFV600E/K mutant melanoma. Although patients achieving a complete pathological response (pCR) exhibited superior recurrence-free survival (RFS) versus those who did not, 30% of pCR patients relapsed. We sought to identify whether histopathological features of the pathological response further delineated risk of relapse. METHODS: Surgical resection specimens from DT-treated patients in two phase 2 clinical trials were reviewed. Histopathological features, including relative amounts of viable tumour, necrosis, melanosis, and fibrosis (hyalinized or immature/proliferative) were assessed for associations with patient outcomes. RESULTS: Fifty-nine patients underwent surgical resection following neoadjuvant DT. Patients achieving pCR (49%) had longer RFS compared with patients who did not (P = 0.005). Patients whose treated tumour showed any hyalinized fibrosis had longer RFS versus those without (P = 0.014), whereas necrosis (P = 0.012) and/or immature/proliferative fibrosis (P = 0.026) correlated with shorter RFS. Multivariable analyses showed absence of pCR or presence of immature fibrosis independently predicted shorter RFS. Among pCR patients, mature/hyalinized-type fibrosis correlated with improved RFS (P = 0.035). CONCLUSIONS: The extent and composition of the pathological response following neoadjuvant DT in BRAFV600E/K mutant melanoma correlates with RFS, including pCR patients. These findings support the need for detailed histological analysis of specimens collected after neoadjuvant therapy.

One-Pot Synthesis of Magnesium Aminoclay-Titanium Dioxide Nanocomposites for Improved Photocatalytic Performance.

TiO2 nanoparticles (NPs) with their excellent photocatalytic performance are among the hottest research subjects for environmental-cleanup applications. In the present work, we developed a method of one-pot synthesis of magnesium aminoclay-titanium dioxide [MgAC-TiO2] nanocomposites in ethanol solution and then treated the obtained nanocomposites in a 350 °C muffle furnace for 3 hours. The obtained X-ray diffraction (XRD) patterns confirmed the growth of the anatase TiO2 NPs in the amorphous MgAC phase. In the scanning electron microscopy (SEM) morphological observation, the MgAC-TiO2 nanocomposites exhibited an aggregate form of 246.59 ± 54.20 nm diameter. The synthesis condition entailing loading of 0.3 g MgAC and 5 mL titanium butoxide (TB) (denoted as MgAC [0.3 g]-TiO2 in 40 mL ethanol solution displayed the largest BET surface area, 234.91 m2/g, as well as the largest pore size and pore volume, 6.7131 nm and 0.3942 cm3/g, respectively. Also, MgAC [0.3 g]-TiO2 showed the best photocatalytic performance for methylene blue (MB) on the batch scale under 365 nm wavelength irradiation: a degradation constant rate of 0.0293 min-1, which was ~20-times-better photocatalytic activity than commercial P25. On the pilot scale (100 L), the MgAC [0.3 g]-TiO2 nanocomposite took only ~12 hours to degrade almost MB at 10 ppm concentration. The mechanism of this high photocatalytic activity was determined to be the high rate of adsorption of both MgAC and oxygen vacancies in the anatase phase coupled with the retardation of the rate of recombination of electrons and holes in the TiO2 NPs, the latter proved by photoluminescent quenching tests.

Guideline on training and credentialing in endoscopic retrograde cholangiopancreatography.

The aim of the Endoscopic Retrograde Cholangiopancreatography (ERCP) Working Group was to examine the issues of training, credentialing and quality control in ERCP in Singapore. Published guidelines and clinical trials concerning issues of training, complications and quality control in ERCP have been reviewed. The Working Group recommended that a trainee reach a minimum threshold of 200 cases before the assessment of competency. The target for achievement of competency was set at an 85 percent successful cannulation rate for native papilla. To perform advanced ERCP, endoscopists should have undergone dedicated training either in a recognised training centre or in conjunction with and under the guidance of a more experienced colleague, until technical competency is achieved. Precut should only be performed by endoscopists with experience and expertise in performing Levels II and III ERCP, who have been formally proctored. An audit of ERCP should examine parameters such as appropriate indication, success rates of selective cannulation, technical success rate of commonly performed procedures and procedure-related complications. To maintain technical competency, an individual should be performing ERCP on a regular basis. In conclusion, the innate risks of ERCP necessitate that all ERCP practitioners should be appropriately trained, practise within their expertise level and maintain regular practice in order to minimise risks and improve patient outcome.

Effect of antimicrobial coatings on the radiosensitization of Escherichia coli, Salmonella typhimurium, and Listeria monocytogenes in fresh broccoli.

Radiosensitization of Listeria monocytogenes, Escherichia coli, Salmonella Typhimurium, and aerobic microflora was evaluated in broccoli florets coated by antimicrobial coatings and treated with different doses of γ-radiation. Broccoli florets were inoculated with aerobic microflora isolated from broccoli and with pathogenic bacteria (L. monocytogenes, E. coli, and Salmonella Typhimurium) at 10(6) CFU/ml. Inoculated florets were then coated with methylcellulose-based coating containing various mixtures of antimicrobial agents: organic acids plus lactic acid bacteria (LAB metabolites), organic acids plus citrus extract, organic acids plus citrus extract plus spice mixture, and organic acids plus rosemary extract. Coated florets were irradiated with various doses (0 to 3.3 kGy), and microbial analyses were conducted to calculate the D(10)-value and relative sensitivity. All antimicrobial coatings had almost the same effect of increasing the radiosensitivity of L. monocytogenes (from 1.31 to 1.45 times) to γ-irradiation. The coating containing organic acid plus citrus extract was the most efficient formulation for increasing the radiosensitization of E. coli and aerobic microflora, by 2.40 and 1.76 times, respectively, compared with the control without the antimicrobial coating. The coating containing organic acids plus LAB metabolites was the most effective formulation for increasing the radiosensitization (by 2.4 times) of Salmonella Typhimurium. Results suggest that the spice extract, when mixed with organic acids and citrus extract, might protect E. coli and aerobic microflora from the effects of γ-irradiation.

Optimization of spray drying process for Bacillus thuringiensis fermented wastewater and wastewater sludge.

Response surface methodology was used to optimize spray drying process for producing biopesticide powders of Bacillus thuringiensis by using fermented broth of starch industry wastewater and wastewater sludge. Analysis of variance was carried out using number of viable spores in the powder as dependent variable. The determination coefficients of models were 92 and 94% for fermented broth of starch industry wastewater and wastewater sludge, respectively. Under the optimal conditions of the operational parameters of spray drying, the numbers of viable spores were 2.2 × 10(8) and 1.3 × 10(8) CFU/mg in the dry powders for starch industry wastewater and wastewater sludge respectively, with a loss of viable spores of 18 and 13% when compared with their respective fermented broths. The entomotoxicity (measured by the bioassay method) of the powders obtained under optimal conditions showed a loss of 28 and 18% when compared with the fermented broth of starch industry wastewater and wastewater sludge, respectively. The optimized results of spray drying were used for field application calculations. The volume of fermented broth required to produce powder formulated product when compared with the volume required for liquid formulation product in order to treat 1 ha of balsam fir was less and offered several advantages.

Screening for hepatitis B surface antigen before chemotherapy: current practice and opportunities for improvement.

INTRODUCTION: Hepatitis B virus (hbv) reactivation is a recognized complication of chemotherapy. The U.S. Centers for Disease Control and Prevention recommend that all patients be screened for the hbv surface antigen (hbsag) before chemotherapy. We sought to determine the frequency of hbsag testing before chemotherapy at our hospital and to increase the frequency of testing to more than 90% of patients starting chemotherapy. METHODS: Using a retrospective electronic chart review, we identified the frequency of hbsag testing for patients initiated on intravenous chemotherapy at out institution between March 2006 and March 2007. The frequency of left ventricular function testing in the subgroup of patients receiving potentially cardiotoxic chemotherapy was identified as a comparator. An educational intervention was developed and delivered to the multidisciplinary oncology team. The frequency of hbsag testing was determined post intervention. Qualitative interviews were conducted with the members of the oncology team to identify risk perception and barriers to testing. RESULTS: Of 208 patients started on intravenous chemotherapy between March 2006 and March 2007, only 28 (14%) were tested for hbsag. All 138 patients scheduled for cardiotoxic chemotherapy (100%) underwent left ventricular function testing. In the post-intervention phase, of 74 patients started on intravenous chemotherapy, 24 (31%) underwent hbsag testing, with 1 patient testing positive. CONCLUSIONS: The frequency of testing for hbsag before chemotherapy was very low at our institution. An educational intervention resulted in only a modest improvement. Potential barriers to routine screening include lack of awareness about existing guidelines, controversy about the evidence that supports hbsag testing guidelines, and a perception by physicians that hbv reactivation does not occur with solid tumours.

Very low loss reactively ion etched Tellurium Dioxide planar rib waveguides for linear and non-linear optics.

We report on the fabrication and optical properties of the first very low loss nonlinear Tellurite planar rib waveguides ever demonstrated. A new reactive ion etch process based on Hydrogen as the active species was developed to accomplish the low propagation losses. Optical losses below approximately 0.05 dB/cm in most of the NIR spectrum and approximately 0.10 dB/cm at 1550 nm have been achieved - the lowest ever reported by more than an order of magnitude and clearly suitable for planar integrated devices. We demonstrate strong spectral broadening of 0.6 ps pulses in waveguides fabricated from pure TeO(2), in good agreement with simulations.

Adaptive pulse shape control in a diode-seeded nanosecond fiber MOPA system.

We demonstrate active shaping of the driving electrical pulses to a laser diode in order to compensate for the pulse shaping effects of gain saturation in an Yb doped fiber amplifier cascade and to allow the generation of user defined customized output pulse shapes. In particular we demonstrate the generation of square output pulses, which have the potential to significantly increase the maximum pulse energy extractable from an amplifier before the peak power reaches the threshold for SRS, and for high efficiency frequency conversion.

Optimisation of cascaded Yb fiber amplifier chains using numerical-modelling.

We show that it is possible to adapt existing software packages developed originally for modeling telecommunication devices and systems to reliably predict and optimize the performance of high-power Ytterbium-doped fiber amplifier and laser systems. The ready availability of a flexible, user-friendly design tool should be of considerable practical interest to scientists and engineers working with this important new laser technology since Ytterbium amplifier and amplifier cascades are often difficult to optimize experimentally due to the three-level nature of the Ytterbium laser transition. As examples of the utility and accuracy of the software, as well as the complexity of the systems and amplifier properties that can be successfully modeled, we present a comparison of experimental and theoretical results for individual core and cladding pumped amplifiers, and also for an ultra-short pulse four-stage amplifier system optimized both to provide a broad gain bandwidth and to minimize nonlinear effects. We also show how high energy 100 ns pulses with complex user definable temporal profiles can be created in a gain-saturated amplifier by suitable pre-shaping of the low-energy input pulses. Furthermore, with appropriate modifications the same software package can be applied to fiber amplifiers based on other rare-earth elements and glass hosts.

Ultrasound-based liver computer assisted surgery.

Ongoing research toward development of a computer-assisted, ultrasound-based software/hardware tool to improve instrument positioning in moving organs during minimally invasive abdominal surgery is presented. The main objective of this research is to calculate, in real time and without user intervention, the pre-/intra-operative 3D/2D image misalignment due to patient respiration and the shift induced by the surgical instrument. Our methodology applied to the particular case of the liver, and partial results related to the image registration approach, based on organ segmentation and shape description, are presented. Preliminary results are highly encouraging. Among other benefits, use of this tool will increase surgeon confidence and improve surgery outcomes.

Determinants of right-left and top-bottom prevalence for two-dimensional spatial compatibility.

When stimulus and response sets vary along horizontal and vertical dimensions, the horizontal dimension is more dominant than the vertical one, an effect called right-left prevalence. Three accounts have been proposed that attribute the effect to a reduced ability to code vertical locations when horizontal codes are also present, the use of right-left effectors, or a difference in salience of the 2 dimensions. The accounts differ in terms of whether the ability to code and process the 2 dimensions is of limited capacity and whether the prevalence effect is a consequence of the effectors used for responding. The authors report 4 experiments that evaluated these issues. Results indicate that use of right-left effectors is important to the right-left prevalence effect because it increases the salience of the horizontal dimension. However, a top-bottom prevalence effect can be obtained if the vertical dimension is made more salient.

Mixing incompatible mapped location-relevant trials with location-irrelevant trials: effects of stimulus mode on the reverse Simon effect.

When location-relevant trials with an incompatible spatial stimulus-response mapping are mixed with location-irrelevant trials, responses on the latter trials are faster when stimulus and response locations do not correspond than when they do. Experiments 1 and 2 showed that this reverse "Simon effect" also occurs when the location information is presented verbally or symbolically on both location-relevant and location-irrelevant trials. The reversal was absent, however, in conditions of Experiments 1-3 in which the mode of presentation was different on the location-relevant trials than on the location-irrelevant trials. Experiment 4 demonstrated that differences in physical characteristics between the location-relevant and location-irrelevant stimuli were not sufficient to eliminate the reverse Simon effect. These findings imply that the short-term associations between stimulus location information and responses defined for the location-relevant task are relatively mode specific.

Vertical versus horizontal spatial compatibility: right-left prevalence with bimanual responses.

For two-choice tasks in which stimulus and response locations vary along horizontal and vertical dimensions, the spatial compatibility effect is often stronger on the horizontal than vertical dimension. Umiltà and Nicoletti [(1990) Spatial stimulus-response compatibility (pp. 89-116). Amsterdam: North-Holland] attributed this right-left prevalence effect to an inability to code vertical location when horizontal codes are present simultaneously. Hommel [(1996) Perception & Psychophysics, 43, 102-110] suggested instead that it reflects a voluntary strategy. This study reports four experiments that examine this issue. Experiment 1 was a conceptual replication of Hommel's Experiment 1, with responses made on a numeric key-pad and subjects instructed in terms of the vertical or horizontal dimension. The results replicated Hommel's findings that showed a right-left advantage with horizontal instructions; however, with vertical instructions, we found a benefit of vertical compatibility alone that he did not. This benefit for vertical compatibility alone was eliminated in Experiment 2 using a varied practice schedule similar to that used by Hommel. Experiment 3 showed right-left prevalence and a benefit of vertical compatibility alone, even with varied practice and vertical instructions, when subjects responded on perpendicularly arranged hand-grips. These benefits were eliminated in Experiment 4 using Hommel's method of urging subjects to respond only in terms of the instructed dimension. With bimanual responses, right-left prevalence is a robust phenomenon that is evident when comparing across vertical and horizontal instructions and, when the right-left distinction is relatively salient, within the vertical instructions condition alone.

Stereospecific versus nonstereospecific assessments for the bioequivalence of two formulations of racemic chlorpheniramine.

Chlorpheniramine (chlorphenamine, CPAM) is a racemic antihistaminic H1 drug containing two enantiomers. The aim of this study was to assess the bioequivalence of two formulations (reference and Vietnamese-tested formulation) of racemic chlorpheniramine combined with phenylpropanolamine in an open-labeled, randomized, crossover two-period study, after administration of 8 mg of racemic chlorpheniramine in 12 healthy Vietnamese subjects. First, dissolution of both formulations was tested in vitro according to USP requirements. Then the 12 subjects received both formulations after an overnight fast and a 7-day wash-out period. Plasma samples were collected up to 168 h. Plasma concentrations of total chlorpheniramine and its individual enantiomers were determined with a validated chiral HPLC method and pharmacokinetic parameters were estimated using model-independent analysis. For the reference formulation, Cmax and AUC values were higher for (+)S-chlorpheniramine ((+)S-CPAM) compared to (-)R-chlorpheniramine ((-)R-CPAM) (13.3 vs. 6.8 ng/ml and 409 vs. 222 ng/ml/h, respectively) while Clt/F and Vd/F were lower (9.8 vs. 17.6 l/h and 321 vs. 627 l, respectively). No difference was observed for Tmax, t(1/2), and MRT. Pharmacokinetic parameters were similar for the reference and the Vietnamese-tested formulation. Bioequivalence was assessed by Schuirmann test, as recommended by the current FDA and European Community criteria. Dissolution tests showed that both formulations were equivalent. A nonstereospecific, but not a stereospecific, approach indicated bioequivalence between the formulations.

Program directors' perspectives on federally funded fellowship training in primary care research.

PURPOSE: To describe the organization, models of training, and institutional impact of National Research Service Award fellowship programs in primary care research. METHOD: Survey of 25 directors of currently-funded and former training sites. RESULTS: Twenty-four program directors (96%) completed the survey. Programs allocated 39% of fellows' time to course work leading to an advanced degree or other didactic instruction, and 40% of time to the conduct of research. Collaborations with other training programs within the institution occurred at 83% of sites. Programs commonly (54%) or exclusively (42%) relied on a research model of "early research independence" in which the fellow defined an area of research interest, rather than an "apprenticeship" model in which the fellow worked in a senior investigator's research area. These programs enriched the local academic environment, but required extensive financial subsidies. The high costs of training often had adverse impacts on recruitment and other components of the training process. CONCLUSION: Research training programs in primary care often substitute acquisition of advanced degrees for early immersion in research. The "early independence" model of research differs from fellowships in the medical specialties, and requires further study to assess its effectiveness. The need to subsidize training costs poses substantial problems for the institutions that host these fellowship programs.

Patient age and cancer treatment decisions. Patient and physician views.

PURPOSE: The purpose of this study was to examine patient and physician factors influencing the decision to use adjuvant chemotherapy for stage III colon cancer in elderly persons. DESCRIPTION OF STUDY: A cross-sectional mailed population-based survey of patients 65 years of age and older who had undergone surgical resection of stage III colon cancer in Colorado between August 1995 and December 1997 were identified by the statewide cancer registry (n = 276) and their treating physicians (n = 232). A questionnaire about the determinants of colon cancer treatment decisions was mailed to all patients for whom physician permission was granted (n = 119). A similar questionnaire was sent to treating physicians. RESULTS: Ninety-two physicians (internal medicine 23%; family medicine 12%; surgery 37%; and oncology 24%) and 67 patients (mean age 75.8 years; 55% women) completed surveys. Fifty-four (80.6%) of the patients had received adjuvant chemotherapy. The major determinants of receiving adjuvant chemotherapy were having seen an oncologist (P = .003), being younger (P = .003), and being married (P = .021). After controlling for other potential influences, only having seen an oncologist (odds ratio 8.0; confidence interval 1.5-43.1) remained significantly associated with the receipt of chemotherapy. Physicians were more likely than patients to rank comorbid conditions (39.1% versus 3.0%, respectively; P < .001) and the medical literature (20.7% versus 4.5%, respectively; P = .004) as important factors in making treatment decisions, while patients were more likely than physicians to rank physician opinion (73.1% versus 26.1%, respectively; P = .001), family preference (31.3% versus 9.8%, respectively; P = .001), and family burden (10.4% versus 2.2%, respectively; P = .038). CLINICAL IMPLICATIONS: In this elderly population, patient age is not recognized by patients or physicians as affecting the decision to use adjuvant chemotherapy. Other biologic and social factors are important, however, and the perspectives of physicians and patients differ regarding their relative importance.

Determination of arsenic in urine by atomic absorption spectrophotometry for biological monitoring of occupational exposure to arsenic.

An atomic absorption spectrophotometric (AAS) method was successfully applied to analysis of urine for arsenic (As) as a measure of biological monitoring of occupational exposure to As in Vietnam. The application of the method to urine samples from 75 non-exposed control urbanites (after 2-day abstinence from sea foods) gave a reference level of 62.4 +/- 11.6 microg/l (as mean +/- S.D.), from which the upper limit of the normal value (74 microg/l as mean +/- 1 S.D.) and the acceptable limit (100 microg/l as mean +/- 3S.D.) were deduced. Further application to urine samples from 147 workers occupationally exposed to As in Bacthai Non-ferrous Metallurgic Corporation showed significantly elevated levels of As in urine, with mean +/- S.D. of 78.5 +/- 20.2 microg/l. Improvement of working conditions to reduce As exposure resulted in substantial reduction in the ratio of those with urinary As at the level in excess of the acceptable limit. The practical importance of total arsenic determination in urine after 2-day sea food abstinence is discussed in connection with current conditions in analytical laboratories in Vietnam.

Index of norms and ratings published in the Psychonomic Society journals.

The journals of the Psychonomic Society have served as outlets for numerous stimulus norms and ratings. Such norms are useful to researchers in a variety of areas for manipulating and controlling stimulus attributes. This article presents an index of 142 norms published in the Society's journals, categorized according to the types of materials and ratings that are included in each.