Robust colorimetric detection based on the anti-aggregation of gold nanoparticles for bromide in rice samples

Inorganic bromide (Br⁻) is an important contaminant ion as it can originate from the overuse of illegal methyl bromide as a fumigant in stored rice samples. Herein, we developed a simple and highly sensitive colorimetric sensor for bromide ion detection in rice samples. The sensor is based on the anti-aggregation of gold nanoparticles (AuNPs) by Br⁻ in the presence of Cr³⁺, which made the method more selective than other typical aggregations of nanoparticles. The AuNPs underwent an aggregation process as a result of the coordination of Cr³⁺ and the carboxylate group of a citrate ion stabilized the AuNPs, resulting in a red-to-blue color change. When Br⁻ was pre-mixed with the AuNPs and Cr³⁺ was added, the solution color changed from blue to red with an increase in the Br⁻ concentration. The anti-aggregation process can be detected with the naked eye and monitored using UV-vis spectrophotometry. The linear calibration curve ranged between 0.31 and 3.75 μM Br⁻ with a low LOD and LOQ of 0.04 and 0.13 μM. The recovery was excellent, ranging from 79.9–92.2% with an RSD of less than 4.0%. The good inter-day and intra-day precisions were 2.9–6.4% and 3.1–7.1%, respectively. The developed sensor has proved to provide a robust method for Br⁻ detection in rice samples.

In this work, we developed a AuNP colorimetric sensor for the facile, sensitive and selective detection of bromide ions in rice samples.     

Effects of curcumin on reflux esophagitis in rats

The preventive effect of curcumin, a compound isolated from the rhizome of Curcuma longa, on experimental reflux esophagitis in rats was investigated in order to validate its potential therapeutic use for gastroesophageal reflux disease. Curcumin (20 mg/kg, i.d.), the antioxidative agent dimethyl sulfoxide (DMSO) (1 ml/kg, i.p.) or the proton pump inhibitor lansoprazole (1 mg/kg, i.d.) inhibited the formation of acute acid reflux esophagitis by 52.5, 61.5 and 70.9% respectively. Curcumin alone was not effective in preventing chronic acid reflux esophagitis, but the combination of curcumin and DMSO reduced the mortality rate and the severity of the esophagitis ulcer index to the same extent (56.5%) as did the lansoprazole (53.9%). Intraduodenal administration of curcumin also markedly prevented the formation of acute mixed reflux esophagitis, together with reducing the incidence or the severity of neutrophil infiltration, when compared to a control group. In contrast, lansoprazole tended to increase the severity of all histopathological changes, when compared to either the control or the curcumin-treated group. Aminoguanidine, a specific inducible nitric oxide synthase inhibitor, had no preventive effect against both types of acute reflux esophagitis models, and increased the mortality in the chronic acid reflux esophagitis model. From these results, it is indicated that curcumin can effectively prevent acute reflux esophagitis formation. Although curcumin is less potent than lansoprazole in inhibiting acid reflux esophagitis, it is superior to lansoprazole in inhibiting mixed reflux esophagitis. The antiulcerogenic mechanisms are considered to be closely associated with its antioxidant nature and antiinflammatory property.     

The impact of auditory and haptic feedback on computer task performance in patients with age-related macular degeneration and control subjects with no known ocular disease

PURPOSE: To determine the impact of auditory and haptic (tactile) feedback on computer task performance of patients with age-related macular degeneration (AMD) compared to controls. METHODS: Thirty patients with AMD and 29 similarly aged controls with no known ocular disease completed timed computer icon "drag and drop" tasks under all four possible conditions of presence or absence of auditory and haptic feedback in a two-factor repeated measures design. Patient recruitment was stratified by best eye acuity: 20/20-20/50; 20/60-20/100; <20/100. Controls had best eye acuity>or=20/30. Task completion time was quantified using final target highlight time (FTHT) and total trial time, measured in milliseconds. RESULTS: Mean+/-standard deviation (SD) FTHT with neither feedback type in the three patient and control groups was, respectively: 1,110+/-356, 1,682+/-1,069, 1,763+/-831, 924+/-533. Auditory feedback improved performance [%FTHT decrease, p-value] in all groups, respectively: 18%, P=0.018; 38%, P=0.054; 57%, P=0.001; 19%, P=0.001. Haptic feedback improved performance in the worst acuity AMD group and controls: 46%, P=0.009; 17%, P=0.038. In the worst acuity AMD group, auditory and/or haptic feedback was associated with a 4-6 second mean (for each task) reduction in total trial time. CONCLUSION: Auditory and haptic feedback can substantially increase performance speed of computer "drag and drop" tasks for patients with AMD, particularly in those patients with the most compromised vision.     

Etiology and outcome of non-immune hydrops fetalis in southern Thailand

OBJECTIVE: To study the etiology and outcome of non-immune hydrops fetalis in southern Thailand. METHODS: The medical records and videotape recordings of all pregnant women diagnosed with non-immune fetal hydrops, from January 1993 to December 2002 were reviewed. RESULTS: Non-immune hydrops fetalis was documented in 71 cases. The causes of fetal hydrops were identified in 87.3%. Homozygous alpha-thalassemia-1 dominated as the cause of non-immune fetal hydrops (28.2%), followed by structural abnormalities (15.5%) and infection (12.7%). The underlying etiology remained unknown in 9 cases (12.7%). The overall survival rate of non-immune hydrops fetalis cases was 4.2%. Spontaneous regression occurred in 2 cases. Two cases were lost to follow up after initial evaluation. Termination of pregnancy was performed in 47 cases. There were 12 dead fetuses in utero, 2 stillbirths, 5 early neonatal deaths and only 3 cases survived. CONCLUSIONS: Homozygous alpha-thalassemia-1 is the most common cause of non-immune hydrops fetalis in southern Thailand, and the overall prognosis of non-immune hydrops fetalis is poor. We suggest that an effective thalassemia-screening program for prevention and control of homozygous alpha-thalassemia-1 be established in all areas where the alpha-thalassemia-1 gene is prevalent.     

Involvement of reactive oxygen species and stress-activated MAPKs in satratoxin H-induced apoptosis

Satratoxins, members of the trichothecene mycotoxin family, have been known to be harmful to health. However, the mechanisms underlying the toxicity still remain unclear. The present study is undertaken to elucidate the mechanisms of the satratoxin H-induced cytotoxicity in PC12 cells. Satratoxin H caused cytotoxicity, which was reflected from apoptosis determined by chromatin staining and flow cytometry. Satratoxin H stimulated the phosphorylation of extracellular signal-regulated kinase (ERK), p38 mitogen-activated protein kinase (MAPK) and c-Jun N-terminal kinase (JNK). Pre-incubation with SB203580, a p38 MAPK inhibitor, or SP600125, a JNK inhibitor, but not PD98059, an ERK inhibitor, reduced satratoxin-induced cytotoxicity. Co-incubation of cells with glutathione, N-acetyl-L-cysteine or glutathione reductase inhibited cytotoxicity and the phosphorylation of p38 MAPK induced by satratoxin H. Our data suggest that satratoxin H-induced apoptosis in PC12 cells is dependent on the activation of p38 MAPK/JNK and the increase in reactive oxygen species.     

Fetal Cardiac Rhabdomyoma With Hydrops Fetalis

Rhabdomyoma is the most common cardiac tumor in fetuses, often associated with the tuberous sclerosis complex, especially when multiple tumors and a positive family history of tuberous sclerosis are noted. The tumor is often benign and has a tendency to regress but may increase in size until the early third trimester. Fetal cardiac rhabdomyoma complicated by hydrops fetalis and leading to fetal death is rare. We report 2 cases of fetal cardiac rhabdomyoma with hydrops fetalis and provide a review of the literature.     

Impact of Universal Health Care Coverage on patient demand for health care services in Thailand

Fully implemented in Thailand in 2002, the Universal Health Care Coverage (UC) Program aimed to provide cheap access to health care services, for 30 baht (less than 1 U.S. dollar) per visit, to all uninsured Thais. In this paper, we studied the impact of the UC in Thailand on the demand for health care services using hospital level data. We found that the UC program was successful in increasing outpatient demand for health care, particularly the demand from the elderly and the poor. However, outpatient demand for health care dramatically increased during the first year of the program and faded away quickly in subsequent years. In contrast to outpatient demand, the number of inpatient visits and the number of days for which the inpatients were admitted at hospitals declined after the UC program was launched. In this paper, we offer our explanation of these phenomena, highlight problems associated with the UC program, and provide policy recommendations to improve the program.     

Prenatal diagnosis of thalassemia in Songklanagarind Hospital in southern Thailand

A thalassemia screening program for pregnant women has been established in Songklanagarind Hospital since 1992. After genetic counseling, a total of 5078 pregnant women accepted entry into a screening program for thalassemia. Couples at risk who should receive prenatal diagnosis were 2.8%. Total cases who accepted prenatal diagnosis were 135. Total clinical cases were 40 (29.6%) with achievement by prenatal diagnosis of 33 cases (82.5%). Genetic amniocentesis is the most acceptable method for prenatal diagnosis. Five cases (12.5%) were misdiagnosed due to contamination of maternal blood cells in amniotic fluid cases. Questionable results were reported in 2 cases (5%). Abortion occurred in one case (0.7%). Improvement of surgical technic in prenatal diagnosis reduced the complications and contamination of maternal cells. This program shows the feasibility of prevention and control of thalassemia disease in southern Thailand.     

Antiplasmodial sesquiterpene alkaloids from the roots of Maytenus mekongensis

Eight new sesquiterpene alkaloids (1-8) and four known sesquiterpene alkaloids (9-12) have been isolated from the roots of Maytenus mekongensis. Structures were determined using extensive spectroscopic methods. The relative configuration of 7-epi-mekongensine (2) was established by single-crystal X-ray crystallographic analysis. The alkaloids were evaluated for antiplasmodial activity against Plasmodium falciparum, K1 strain, and for cytotoxicity using a panel of cell lines.