Obtaining molecular imagings of pesticide residues on strawberry surfaces with probe sampling followed by ambient ionization mass spectrometric analysis

Thermal desorption-electrospray ionization tandem mass spectrometry (TD-ESI/MS/MS) was used to rapidly characterize the residual pesticides collected on the surface of a strawberry with a metallic probe. Twelve pesticides, including nine fungicides and three miticides, were detected; the results were validated by comparison with results that used solvent extraction followed by gas chromatography/mass spectrometry and liquid chromatography/tandem mass spectrometry analyses. The distribution of pesticide residues on a strawberry's surface was explored by collecting multiple samples using probes from 40 positions on the strawberry, with the collected samples being analyzed with TD-ESI/MS/MS. The obtained molecular information was used to construct mass spectrometry imaging of the strawberry's pesticide residues.

Fluorescence and interactions with thiol compounds of Nile Red-adsorbed gold nanoparticles

We have investigated the interactions between a variety of thiols and Nile Red-adsorbed gold nanoparticles (NRAuNPs). After adding thiols to solutions of NRAuNPs, the solutions fluoresce strongly as a result of the displacement of a Nile Red-derived product from the surface of the AuNPs. We propose a mechanism for the formation of this NR product on the surface of AuNPs by conducting mass spectrometry, fluorescence, and capillary electrophoresis measurements. By recording the fluorescence changes of the NRAuNP solutions after addition of the thiols, we investigated the interactions between the thiols and NRAuNPs. Using the Langmuir isotherm model, we found that the displacement rate constants for thiols having one carboxyl residue, such as 3-mercaptopropionic acid, fall within the range 0.55-1.19 x 10(-2) s(-1). Thiols containing hydroxyl groups [e.g., 2-mercaptoethanol (2-ME)] or amino groups [e.g., N-(2-mercaptopropionyl)glycine (MPG)], or that have flat structures on the AuNP surface, such as mercaptosuccinic acid, exhibit double-exponential kinetics with first rate constants of 0.51-2.83 x 10(-2) s(-1) and second rate constants of 6.0-23.4 x 10(-4) s(-1). Our results reveal that steric effects and the charge density of the thiols both play important roles in determining the interactions with NRAuNPs. The interactions (displacement and/or induced aggregation) are also dependent on the size of NRAuNPs.

Quercetin inhibition of ROS-dependent and -independent apoptosis in rat glioma C6 cells

In the present study, we investigated the protective mechanism of quercetin (QUE) and its glycosides, rutin (RUT) and quercitrin (QUI), on reactive oxygen species (ROS)-dependent (H(2)O(2)) and -independent (chemical anoxia) cell death in rat glioma C6 cells. Induction of HO-1 protein expression was detected in QUE- but not RUT- or QUI-treated C6 cells, and this was prevented by cycloheximide and actinomycin D. Incubation of C6 cells with QUE, but not RUT or QUI, protected C6 cells from H(2)O(2)- and chemical anoxia-induced cytotoxicity according to the MTT and LDH release assays. Apoptotic characteristics including chromatin condensation, DNA ladders, and hypodiploid cells appeared in H(2)O(2)-and chemical anoxia-treated C6 cells, and those events were significantly suppressed by adding QUE (but not RUT or QUI). Increases in caspase 3, 8, and 9 enzyme activities with decreases in pro-PARP and pro-caspase 3 protein levels and an increase in cleaved D4-GDI protein were identified in H(2)O(2)-and chemical anoxia-treated C6 cells, and these were blocked by the addition of QUE, but not by RUT or QUI. Intracellular peroxide levels increased with H(2)O(2) and decreased with chemical anoxia, and the addition of QUE reduced the intracellular peroxide levels induced by H(2)O(2). Results of an anti-DPPH radical assay showed that QUE, RUT, and QUI dose-dependently inhibited the production of DPPH radicals in vitro; however, QUE (but not RUT or QUI) prevention of DNA damage induced by OH radicals was identified with a plasmid digestion assay. Increases in phosphorylated ERK and p53 protein expressions were detected in H(2)O(2)- but not chemical anoxia-treated C6 cells, and the addition of QUE significantly blocked H(2)O(2)-induced phosphorylated ERK and p53 protein expressions. Adding the HO-1 inhibitors, SnPP, CoPP, and ZnPP, reversed the protective effect of QUE against H(2)O(2)- and chemical anoxia-induced cell death according to the MTT assay and morphological observations. Additionally, QUE exhibited inhibitory effects on LPS/TPA-induced transformation in accordance with a decrease in MMP-9 enzyme activity and iNOS protein expression in C6 cells. Taken together, the results of this study suggest that QUE exhibits an inhibitory effect on both ROS-dependent and -independent cell death, and induction of HO-1 protein expression is involved.

Role of laparoscopic cholecystectomy in the management of polypoid lesions of the gallbladder

This retrospective clinicohistopathologic study was performed to delineate the role of laparoscopic cholecystectomy in the management of polypoid lesions of the gallbladder. One hundred forty-three consecutive patients who had a preoperative sonographic diagnosis of polypoid lesions of the gallbladder with a diameter less than 1.5 cm and who underwent laparoscopic cholecystectomy at Cathay General Hospital were included in the analysis. Histopathologic study showed that 22 (15.4%) patients had true tumors, including adenoma (16), adenoma with focal adenocarcinoma (2), adenocarcinoma (3), and carcinoid tumor (1). Tumorlike lesions were found in 121 (84.6%) patients and included cholesterol polyp (106), adenomyomatous hyperplasia (10), inflammatory polyp (3), and papillary hyperplasia (2). The mean diameter of malignant polypoid lesions of the gallbladder was 1.35 +/- 0.42 cm, which was significantly larger than that of cholesterol polyps (0.66 +/- 0.40 cm, P = 0.0001) but not significantly larger than that of adenomyomatous hyperplasias (1.12 +/- 0.42 cm) and adenomas (1.08 +/- 0.47 cm). The mean age of patients with malignant polypoid lesions of the gallbladder (61.2 +/- 13.3 years old) was significantly older than that of patients with adenomyomatous hyperplasia (46.6 +/- 13.4 years, P = 0.03), cholesterol polyps (44.5 +/- 10.5 years, P = 0.0003), and adenomas (41.4 +/- 9.4 years, P = 0.0008). Clinical follow-up showed that most (98.6%) patients benefited from the minimal invasiveness of laparoscopic cholecystectomy with satisfactory surgical results. We conclude that laparoscopic cholecystectomy is a reliable, safe, and minimally invasive biopsy procedure and definite management of polypoid lesions of the gallbladder with a diameter less than 1.5 cm.

Acoustic and intelligibility characteristics of sentence production in neurogenic speech disorders

The purpose of this study was to examine the relationship between scaled speech intelligibility and selected acoustic variables in persons with dysarthria. Control speakers and speakers with amyotrophic lateral sclerosis (ALS) and Parkinson's disease (PD) produced sentences which were analyzed acoustically and perceptually. The acoustic variables included total utterance durations, segment durations, estimates of the acoustic vowel space, and slopes of formant transitions; the perceptual variables included scaled speech intelligibility and severity of speech involvement. Results indicated that the temporal variables typically differentiated the ALS group, but not the PD group, from the controls, and that vowel spaces were smaller for both neurogenic groups as compared to controls, but only significantly so for the ALS speakers. The relation of these acoustic measures to scaled speech intelligibility is shown to be complex, and the composite results are discussed in terms of sentence vs. single-word intelligibility estimates and their underlying acoustic bases.

Effect of speaking rate manipulations on acoustic and perceptual aspects of the dysarthria in amyotrophic lateral sclerosis

The current study explored the acoustic and perceptual effects of speaking rate adjustments in persons with amyotrophic lateral sclerosis (ALS) and in neurologically normal individuals. Sentence utterances were obtained from the participants at two self-selected speaking rates: habitual and fast. Total utterance durations, segment durations, and vowel formant frequencies comprised the acoustic measures, whereas magnitude estimates of speech intelligibility and severity of speech involvement were the perceptual measures. Results showed that participants in both the neurologically normal and ALS groups were able to increase their speaking rate when asked to do so, but that the participants with ALS were significantly slower than the neurologically normal participants at both rates. Both groups of participants also showed compression of the acoustic vowel space with increased speaking rate, with the vowel spaces of participants with ALS generally being more compressed than the vowel spaces of neurologically normal participants, at either rate. Most importantly, the perceptual measures failed to show any effect of the speaking rate adjustment on scaled intelligibility or severity, for either group. These findings are discussed relative to the general issue of slow habitual speaking rates among many speakers with dysarthria, and possible explanations for the slowness. The lack of an effect of increased rate on the perception of the speech deficit among speakers with ALS argues against the idea that the habitually slow rates are a form of compensation to reduce the complexity of speech production.

Adenocarcinoma of the gastric cardia: prognostic significance of pathologic and treatment factors

The records of 146 patients who had surgery for adenocarcinoma of the gastric cardia between 1977 and 1992 at National Taiwan University Hospital were retrospectively analyzed. The prognostic significance of pathologic and surgical treatment factors was examined by log rank test and stepwise regression procedures. The overall 2-year and 5-year survival rates were 40.2% and 23.7%, respectively. The pathologic factors analyzed included: age, sex, tumor diameter, esophageal invasion, pathologic grading, vascular invasion, perineural invasion, depth of invasion, node-status, distant metastasis and number of positive lymph nodes. The surgical treatment factors analyzed included:surgical procedure, region of lymphadenectomy, resection margin and resection status. Resection status was classified into three categories: absolute curative, relative curative and palliative. Univariate analyses showed that esophageal invasion, vascular invasion, depth of invasion, node status, node number, resection margin and resection status were significant prognostic factors. The selected stepwise regression model identified three significant independent factors: node status, resection status and esophageal invasion. Aggressive surgical management, including combined resection and extended lymphadenectomy, may be helpful for patients with adenocarcinoma of the gastric cardia.