Accurate Intervertebral Disc Segmentation Approach Based on Deep Learning

Automatically segmenting specific tissues or structures from medical images is a straightforward task for deep learning models. However, identifying a few specific objects from a group of similar targets can be a challenging task. This study focuses on the segmentation of certain specific intervertebral discs from lateral spine images acquired from an MRI scanner. In this research, an approach is proposed that utilizes MultiResUNet models and employs saliency maps for target intervertebral disc segmentation. First, a sub-image cropping method is used to separate the target discs. This method uses MultiResUNet to predict the saliency maps of target discs and crop sub-images for easier segmentation. Then, MultiResUNet is used to segment the target discs in these sub-images. The distance maps of the segmented discs are then calculated and combined with their original image for data augmentation to predict the remaining target discs. The training set and test set use 2674 and 308 MRI images, respectively. Experimental results demonstrate that the proposed method significantly enhances segmentation accuracy to about 98%. The performance of this approach highlights its effectiveness in segmenting specific intervertebral discs from closely similar discs.

Sesamin: A Promising Therapeutic Agent for Ameliorating Symptoms of Diabetes

Diabetes is a chronic metabolic disease characterized by improperly regulating proteins, carbohydrates, and lipids due to insulin deficiency or resistance. The increasing prevalence of diabetes poses a tremendous socioeconomic burden worldwide, resulting in the rise of many studies on Chinese herbal medicines to discover the most effective cure for diabetes. Sesame seeds are among these Chinese herbal medicines that were found to contain various pharmacological activities, including antioxidant and anti-inflammatory properties, lowering cholesterol, improving liver function, blood pressure and sugar lowering, regulating lipid synthesis, and anticancer activities. These medicinal benefits are attributed to sesamin, which is the main lignan found in sesame seeds and oil. In this study, Wistar rat models were induced with type 2 diabetes using streptozotocin (STZ) and nicotinamide, and the effect of sesamin on the changes in body weight, blood sugar level, glycosylated hemoglobin (HbA1c), insulin levels, and the states of the pancreas and liver of the rats were evaluated. The results indicate a reduced blood glucose level, HbA1c, TG, and ALT and AST enzymes after sesamin treatment, while increased insulin level, SOD, CAT, and GPx activities were also observed. These findings prove sesamin's efficacy in ameliorating the symptoms of diabetes through its potent pharmacological activities.

Goji Ferment Ameliorated Acetaminophen-Induced Liver Injury in vitro and in vivo

This study aimed to investigate the hepatoprotective effects of lyophilized powder of goji ferment (LPGF) against acetaminophen (APAP)-induced hepatic damage in Hep3B cells and in mice. Eleven strains of lactic acid bacteria (LAB) were selected and their hepatoprotection against APAP-induced cellular damage in Hep3B cell line was evaluated. Four strains of LAB, including BCRC11652 (Leuconostoc mesenteroides subsp. mesenteroides), BCRC14619 (Lactobacillus gasseri), KODA-1 (Pediococcus acidilactici), and KODA-2 (Limosilactobacillus fermentum), have hepatoprotective potential against APAP in vitro. Goji significantly stimulated the growth of individual and combined strains of LAB and the optimal fermented condition was the treatment of goji at 10% (w/w) for 24 h. The prepared lyophilized powder of goji ferment (LPGF) containing fifteen combinations of LAB strains was used to explore their hepatoprotection in vitro. LPGF containing all combinations of LAB strains, except for KODA-2, significantly restored APAP-reduced cell viability and improved APAP-increased cellular levels of alanine aminotransferase (ALT) and aspartate aminotransferase (AST). In mice model, LPGF containing BCRC11652, BCRC14619, and KODA-2 was chosen to evaluate its hepatoprotection against APAP-induced liver injury. LPGF at diverse doses have a tendency but no significant improvement on APAP-reduced body weight gain and liver weight. LPGF significantly decreased APAP-increased serum ALT and AST levels in a dose-dependent manner. At the end of experiment, LPGF significantly and dose-dependently reversed APAP-reduced activities of GSH and antioxidant enzymes, including glutathione peroxidase, superoxide dismutase, and catalase in hepatic tissue. Overall, LPGF was demonstrated to exhibit hepatoprotection against APAP-induced liver injury in vitro and in vivo.

Quercetin supplementation attenuates cisplatin induced myelosuppression in mice through regulation of hematopoietic growth factors and hematopoietic inhibitory factors

The present study investigated the effects of quercetin on cisplatin (CDDP)-induced common side effect, myelosuppression, and the possible mechanisms in Balb/c mice. The mice were randomly treated with CDDP alone or in combination with quercetin for 14 days. Quercetin was given by intraperitoneal injection (10 mg/kg, 3 times a week; IQ) or by a diet containing 0.1% or 1% quercetin (LQ and HQ, respectively). We found that quercetin supplementation especially HQ and IQ, significantly restored the decrease in number of bone marrow cells, total white blood cells, red blood cells and platelets, and the body weight in mice exposed to CDDP (P≤.05). Similar trends were observed in the number of neutrophils, lymphocytes and monocytes in the plasma. HQ and IQ also increased the levels of hematopoietic growth factors (HGFs), especially in granulocyte-macrophage-colony stimulating factor and IL-9 (P<.05), but decreased the levels of hematopoietic inhibitory factors (HIFs) and oxidative stress in the plasma and the bone marrow in CDDP-exposed mice. Furthermore, both quercetin and quercetin-3-O-glucuronide (Q3G) significantly increase cell viability and inhibited apoptosis at 48 or 72 h (P≤.05), accompanied by increasing HGF levels and decreasing HIF levels in the cultured medium in 32D cells exposed to CDDP. IL-9 siRNA transfection suppressed the effects of quercetin and Q3G on cell viability (P≤.05) in32D cells. In conclusion, our results indicate that quercetin attenuates CDDP-induced myelosuppression through the mechanisms associated with regulation of HGFs and HIFs.

Lycopene in Combination With Sorafenib Additively Inhibits Tumor Metastasis in Mice Xenografted With Lewis Lung Carcinoma Cells

Cancer metastasis is the leading cause of death in cancer patients. However, it is unclear whether lycopene can act as an adjuvant to increase the anti-metastatic activity of anticancer drugs. Here, we examined the anti-lung-metastatic effects and the mechanism of lycopene in combination with sorafenib in C57BL/6 mice xenografted with Lewis lung carcinoma (LLC) cells. The mice were divided into five groups: (1) tumor control; (2) lycopene (5 mg/kg); (3) sorafenib (30 mg/kg); (4) lycopene (2 mg/kg) + sorafenib (30 mg/kg); (5) lycopene (5 mg/kg) + sorafenib (30 mg/kg). The results showed that lycopene reduced the number of metastatic tumors in the lungs, which was further suppressed by the combined treatment with sorafenib. The activities of matrix metalloproteinase (MMP)-2 and−9 were further inhibited and TIMP-1 and−2, and NM23-H1, the MMPs negative modulators, were further activated in the combined treatment. Mechanistically, we found that lycopene and sorafenib could additively inhibit the mitogen-activated protein kinase (MAPK) pathways, as shown by the protein phosphorylation of ERK1/2, JNK1/2 and p38 were reduced additively. Overall, the present study demonstrates that lycopene in combination with sorafenib additively inhibits the lung metastasis of tumor, indicating lycopene has potential as an adjuvant for sorafenib in cancer treatment.

Quercetin enhances the antitumor activity of trichostatin A through up-regulation of p300 protein expression in p53 null cancer cells

In the present study, we investigated the p53-independent mechanism by which quercetin (Q) increased apoptosis in human lung cancer H1299 cells exposed to trichostatin A (TSA), a histone deacetylase inhibitor. We also investigated the role of Q in increasing the acetylation of histones H3 and H4 and the possible mechanism. Q at 5 μM significantly increased apoptosis by 88% in H1299 cells induced by TSA at 72 h. Q also significantly increased TSA-induced death receptor 5 (DR5) mRNA and protein expression as well as caspase-10/3 activities in H1299 cells. Transfection of DR5 siRNA into H1299 cells significantly diminished the enhancing effects of Q on TSA-induced apoptosis. Furthermore, TSA in combination with Q rather than TSA alone significantly increased p300 expression. Transfection of p300 siRNA in H1299 cells significantly diminished the increase of histone H3/H4 acetylation, DR5 protein expression, caspase-10/3 activity and apoptosis induced by Q. In addition, similar effects of Q were observed when Q was combined with vorinostat, another FDA-approved histone deacetylase inhibitor. These data suggest that the up-regulation of p300 expression, which in turn increases histone acetylation and DR5 expression, plays an important role in the enhancing effect of Q on TSA/vorinostat- induced apoptosis in H1299 cells.

Quercetin enhances the antitumor effect of trichostatin A and suppresses muscle wasting in tumor-bearing mice

Quercetin, a flavonol, displays anti-inflammatory and anti-cancer properties. This study aimed to investigate whether a diet containing 0.1% or 1% quercetin (LQ and HQ, respectively) enhances the anti-tumor effects of trichostatin A (TSA) and prevents muscle wasting induced by TSA. The positive control group received quercetin intraperitoneally (IQ). Three weeks after injecting A549 cells, nude mice were given TSA alone or in combination with quercetin administered orally or intraperitoneally for 16 weeks. Tumor volumes as well as body, muscle and epididymal fat weights were determined during or after the experiment. Quercetin given as a diet supplement dose-dependently enhanced the anti-tumor potency of TSA (p < 0.05). The enhancing effect of HQ was similar to that of IQ. HQ also significantly increased the expression of p53, a tumor suppressor, in tumor tissues compared with the TSA alone group. In addition, TSA-induced loss of gastrocnemius muscle weight was inhibited by oral quercetin in a dose dependent manner; the efficiencies of LQ and HQ were similar to or better than IQ. Moreover, both LQ and HQ decreased TSA-induced activation of Forkhead box O1 (FOXO1), a crucial transcription factor that regulates muscle wasting associated genes. Consistently, LQ and HQ suppressed muscle wasting associated proteins atrophy gene-1 and muscle ring-finger protein-1 expression as well as increased the myosin heavy chain level in the gastrocnemius muscles. Besides, quercetin attenuated TSA-increased oxidative damage and proinflammatory cytokines (p < 0.05). These findings demonstrate that a diet containing 0.1% or 1% quercetin enhances the antitumor effect of TSA and prevents TSA-induced muscle wasting.

Anti-metastatic effects of isolinderalactone via the inhibition of MMP-2 and up regulation of NM23-H1 expression in human lung cancer A549 cells

Metastatic lung cancer is a leading cause of mortality and has a mortality rate of ≥90%. Isolinderalactone (ILL) is a sesquiterpene lactone compound that has been used in traditional Chinese medicine. Research has demonstrated that ILL has anti-inflammatory and anti-proliferative properties; however, to the best of our knowledge, studies investigating whether ILL can inhibit lung cancer cell metastasis have not been conducted. In the present study, 1-10 µM ILL was applied in the culturing of the A549 lung cancer cell line to investigate the effects of ILL on the invasion and migration of lung cancer cells, including whether the possible mechanisms of ILL are associated with the expression of matrix metalloproteinase (MMP)-2 and NME/NM23 nucleoside diphosphate kinase 1 (NM23-H1) genes. The results of the present study indicated that ILL inhibited the invasion and migration of the A549 cancer cells and exhibited a dose-response association. ILL also significantly inhibited the protein expression and activity of MMP-2 (P<0.05), exhibiting a trend similar to that of its invasion- and migration-associated properties. Further research revealed that ILL significantly increased the expression of NM23-H1 protein and inhibited the expression of β-catenin protein (P<0.05). The results of the present study is, to the best of our knowledge, the first to confirm that ILL can inhibit the invasion and migration of A549 cancer cells, with the possible mechanisms potentially involving the inhibition of MMP-2 and β-catenin protein expression resulting from the up regulation of NM23-H1 expression.

Multi-Carotenoids at Physiological Levels Inhibit VEGF-Induced Tube Formation of Endothelial Cells and the Possible Mechanisms of Action Both In Vitro and Ex Vivo

Carotenoids have been shown to exhibit antiangiogenic activities. Several studies have indicated that carotenoids used in combination were more effective on antioxidation and anticancer actions than carotenoids used singly. However, it is unclear whether multi-carotenoids have antiangiogenic effects. We investigated the effects of multi-carotenoids at physiological plasma levels of Taiwanese (abbreviated as MCT, with a total of 1.4 μM) and Americans (abbreviated as MCA, with a total of 1.8 μM), and of post-supplemental plasma levels (abbreviated as HMC with a total of 3.55 μM) on vascular endothelial growth factor (VEGF)-induced tube formation in human umbilical vein endothelial cells (HUVECs) and rat aortic rings. MCT, MCA, and HMC inhibited VEGF-induced migration, invasion, and tube formation of HUVECs as well as new vessels formation in rat aortic rings. MCT, MCA, and HMC inhibited activities o\f matrix metalloproteinase (MMP)-2, urokinase plasminogen activator, and phosphorylation of VEGF receptor 2 induced by VEGF. Moreover, MCT, MCA, and HMC significantly upregulated protein expression of tissue inhibitors of MMP-2 and plasminogen activator inhibitor-1. These results demonstrate the antiangiogenic effect of multi-carotenoids both in vitro and ex vivo with possible mechanistic actions involving attenuation of VEGF receptor 2 phosphorylation and extracellular matrix degradation.

From Theory to Practice: Measuring end-of-life communication quality using multiple goals theory

OBJECTIVES

To describe how multiple goals theory can be used as a reliable and valid measure (i.e., coding scheme) of the quality of conversations about end-of-life issues.

METHODS

We analyzed conversations from 17 conversations in which 68 participants (mean age=51years) played a game that prompted discussion in response to open-ended questions about end-of-life issues. Conversations (mean duration=91min) were audio-recorded and transcribed. Communication quality was assessed by three coders who assigned numeric scores rating how well individuals accomplished task, relational, and identity goals in the conversation.

RESULTS

The coding measure, which results in a quantifiable outcome, yielded strong reliability (intra-class correlation range=0.73-0.89 and Cronbach's alpha range=0.69-0.89 for each of the coded domains) and validity (using multilevel nonlinear modeling, we detected significant variability in scores between games for each of the coded domains, all p-values <0.02).

CONCLUSIONS

Our coding scheme provides a theory-based measure of end-of-life conversation quality that is superior to other methods of measuring communication quality.

PRACTICE IMPLICATIONS

Our description of the coding method enables researches to adapt and apply this measure to communication interventions in other clinical contexts.

Extract of Monascus purpureus CWT715 Fermented from Sorghum Liquor Biowaste Inhibits Migration and Invasion of SK-Hep-1 Human Hepatocarcinoma Cells

Liver cancer is the most endemic cancer in a large region of the world. This study investigated the anti-metastatic effects of an extract of Monascus purpureus CWT715 (MP) fermented from sorghum liquor biowaste and its mechanisms of action in highly metastatic human hepatocarcinoma SK-Hep-1 cells. Kinmen sorghum liquor waste was used as the primary nutrient source to produce metabolites (including pigments) of MP. In the presence of 10 µg/mL MP-fermented broth (MFB), the anti-invasive activity increased with increasing fermentation time reaching a maximum at six days of fermentation. Interestingly, MFB also produced maximal pigment content at six days. Treatment for 24 h with MFB (10–100 µg/mL) obtained from fermentation for six days significantly inhibited cell migration and invasion, and these effects were concentration-dependent. MFB also significantly enhanced nm23-H1 protein expression in a concentration-dependent manner, which was highly correlated with migration and invasion. These results suggest that MFB has significant anti-migration and anti-invasion activities and that these effects are associated with the induction of nm23-H1 protein expression.

Salvianolic acid A alleviates ischemic brain injury through the inhibition of inflammation and apoptosis and the promotion of neurogenesis in mice

Salvianolic acid A (SalA), a chemical type of caffeic acid trimer, has drawn great attention for its potent bioactivities against ischemia-induced injury both in vitro and in vivo. In this study, we evaluated SalA's protective effects against acute ischemic stroke by inducing middle cerebral artery occlusion/reperfusion (MCAO) injuries in mice. Treatment of the mice with SalA (50 and 100μg/kg, i.v.) at 2h after MCAO enhanced their survival rate, improved their moving activity, and ameliorated the severity of brain infarction and apoptosis seen in the mice by diminishing pathological changes such as the extensive breakdown of the blood-brain barrier (BBB), nitrosative stress, and the activation of an inflammatory transcriptional factor p65 nuclear factor-kappa B (NF-κB) and a pro-apoptotic kinase p25/Cdk5. SalA also intensively limited cortical infarction and promoted the expression of neurogenesis protein near the peri-infarct cortex and subgranular zone of the hippocampal dentate gyrus by compromising the activation of GSK3β and p25/Cdk5, which in turn upregulated β-catenin, doublecortin (DCX), and Bcl-2, most possibly through the activation of PI3K/Akt signaling via the upregulation of brain-derived neurotrophic factor. We conclude that SalA blocks inflammatory responses by impairing NF-κB signaling, thereby limiting inflammation/nitrosative stress and preserving the integrity of the BBB; SalA also concomitantly promotes neurogenesis-related protein expression by compromising GSK3β/Cdk5 activity to enhance the expression levels of β-catenin/DCX and Bcl-2 for neuroprotection.

Antihyperlipidemic activity of Allium chinense bulbs

Allium chinense is a medicinal plant and nutritional food commonly used in Eastern Asia. In this study, we investigated the in vitro antioxidant activity (scavenging of α,α-diphenyl-β-picrylhydrazyl free radical, total phenol content, reducing power, and total antioxidant activity) and constituents of various extracts from A. chinense. Moreover, we also studied the in vivo hypolipidemic effects of extracts on high-fat-diet Wistar rats. Ethanol extracts from A. chinense showed notable antioxidant activity, and its high-dose essential-oil extract both significantly reduced serum and hepatic total cholesterol, triglyceride, and low-density lipoprotein levels and increased serum high-density lipoprotein levels in high-fat-diet Wistar rats compared with those observed following treatment with the control drug probucol. Additionally, visceral fat in high-fat-diet Wistar rats was reduced. Furthermore, groups with high doses of essential-oil and residue extracts showed protective effects associated with histopathological liver alteration. These results suggested that A. chinense is a valuable plant worthy of further investigation as a potential dietary supplement or botanical drug.

Quercetin metabolites inhibit MMP-2 expression in A549 lung cancer cells by PPAR-γ associated mechanisms

Our previous study demonstrated that quercetin-metabolite-enriched plasma (QP) but not quercetin itself upregulates peroxisome proliferator-activated receptor gamma (PPAR-γ) expression to induce G2/M arrest in A549 cells. In the present study, we incubated A549 cells with QP as well as quercetin-3-glucuronide (Q3G) and quercetin-3'-sulfate (Q3'S), two major metabolites of quercetin, to investigate the effects of quercetin metabolites on cell invasion and migration, the possible mechanisms and the role of PPAR-γ. We also compared the effects of QP with those of quercetin and troglitazone (TGZ), a PPAR-γ ligand. The results showed that QP significantly suppressed cell invasion and migration, as well as matrix metalloproteinases (MMPs)-2 activity and expression in a dose-dependent manner. The effects of 10% QP on those parameters were similar to those of 10μM quercetin and 20μM TGZ. However, QP and TGZ rather than quercetin itself increased the expressions of nm23-H1 and tissue inhibitor of metalloproteinase (TIMP-2). Furthermore, we demonstrated that Q3G and Q3'S also inhibited the protein expression of MMP-2. GW9662, a PPAR-γ antagonist, significantly diminished such an effect of Q3G and Q3'S. Silencing PPAR-γ expression in A549 cells also significantly diminished the suppression effect of Q3G and Q3'S on MMP-2 expression. Taken together, our study demonstrated that QP inhibited cell invasion and migration through nm23-H1/TIMP-2/MMP-2 associated mechanisms. The upregulation of PPAR-γ by quercetin metabolites such as Q3G and Q3'S could play an important role in the effects of QP.

Combination Therapy Using Chelating Agent and Zinc for Wilson's Disease

There is no clear international consensus regarding the optimal medication therapy for treating Wilson's disease (WD). This study systematically reviews the effectiveness of various medication therapies in common use, specifically focusing on preliminary findings concerning the combination of a chelating agent and zinc. A systematic PubMed search was executed to locate original studies on the effectiveness of commonly used medications for WD published between January 1989 and August 2014. The results were used to conduct a systematic review of studies on combination therapies. A total of 17 combination therapy studies involving 1056 patients were reviewed. These were analyzed in terms of data on effectiveness, adverse effects, and mortality. Results from a pooled analysis indicate that combination therapies for hepatic patients were significantly less effective than the same therapies for neurological manifestations (47.1 vs. 78.6 %; pooled relative risk ratio (RR): 0.63, 95 % confidence interval CI 0.43-0.94; p = 0.02). Data from a subgroup analysis show that the combination therapy of penicillamine plus zinc sulfate resulted in a significantly higher mortality rate compared to all other combination therapy types (16.3 vs. 4.7 %; RR: 3.51, 95 % CI 1.54-8.00; p < 0.001). The use of combination therapies involving zinc and a chelator should be carefully monitored with close clinical observations and frequent biochemical tests, especially for WD patients with hepatic manifestations.

Comparing the metabolism of quercetin in rats, mice and gerbils

PURPOSE

Several species of rodents are used to investigate the metabolism of quercetin in vivo. However, it is unclear whether they are a proper animal model. Thus, we compared the metabolism of quercetin in Wistar rats (rats), Balb/c mice (mice) and Mongolian gerbils (gerbils).

METHODS

We determined the levels of quercetin metabolites, quercetin-3-glucuronide (Q3G), quercetin-3'-sulfate (Q3'S) and methyl-quercetin isorhamnetin (IH), in the plasma, lungs and livers of three species of animals by high-performance liquid chromatography after acute and/or chronic quercetin administration. The metabolic enzyme activities in the intestinal mucosal membrane and liver were also investigated.

RESULTS

First, we found that after acute quercetin administration, the Q3'S level was the highest in gerbils. However, after long-term supplementation (20 weeks), Q3G was the dominant metabolite in the plasma, lungs and livers followed by IH and Q3'S in all animals, although the gerbils still had a higher Q3'S conversion ratio. The average concentrations of total quercetin concentration in the plasma of gerbils were the highest in both short- and long-term studies. The activities of uridine 5'-diphosphate-glucuronosyltransferase, phenolsulfotransferase and catechol-O-methyltransferase were induced by quercetin in a dose- and tissue-dependent manner in all animals.

CONCLUSIONS

Taken together, in general, after long-term supplementation the metabolism of quercetin is similar in all animals and is comparable to that of humans. However, the accumulation of quercetin and Q3'S conversion ratio in gerbils are higher than those in the other animals.

Beyond-limit light focusing in the intermediate zone

We experimentally verify that a new nanolens of a designed plasmonic aperture can focus visible light to a single line with its width smaller than the limit of half the wavelength in the intermediate zone. The experimental measurement indicates that while the near field plays a role to increase the spot size in the near zone, it is negligible at the beyond-limit focused region; i.e., the focused light is dominated by the radiative fields. The image taken by the optical microscope shows that the fields focused have propagated to the far zone. Besides being of academic interest, the nanolens capable in achieving a lower diffraction limit in the intermediate zone is important for application possibilities.

Plasma rich in quercetin metabolites induces G2/M arrest by upregulating PPAR-γ expression in human A549 lung cancer cells

In this study, we incubated human A549 lung cancer cells with quercetin-metabolite-enriched plasma (QMP) obtained from Mongolian gerbils 2 h after quercetin feeding (100 mg/kg body wt/week). We investigated the effects of QMP on the growth of A549 cells and the possible mechanisms for these effects. We found that QMP but not control plasma (CP) reduced the cell growth in A549 cells. QMP led to cell cycle arrest at the G (2)/M phase by downregulating the expression of cdk1 and cyclin B. QMP but not CP or quercetin itself significantly increased PPAR- γ expression (p < 0.05), which was accompanied by an increase of phosphatase and tensin homologue deleted on the chromosome ten level and a decrease of phosphorylation of Akt. Furthermore, quercetin-3-glucuronide and quercetin-3'-sulfate also significantly increased PPAR- γ expression in A549 cells. GW9662, a PPAR- γ antagonist, significantly suppressed the effects of 10 % QMP on cell proliferation and on the expression of cyclin B and cdk1. Taken together, these data suggest that the activation of PPAR- γ plays an important role, at least in part, in the antiproliferative effects of quercetin metabolites.

DNA strand breakage and lipid peroxidation after exposure to welding fumes in vivo

A remarkable number of complex aerosols are generated from welding processes. The objective of this study was to compare DNA damage and lipid peroxidation in plasma and in lung and in liver tissue of rats exposed to welding fumes in an exposure chamber with those of control animals. Three air samples from the chamber were also collected to assess the exposure dose for each exposure (total samplings = 18). Eight male Sprague-Dawley rats were exposed to welding fumes at a concentration of 1540.76 mg/m(3) for 10 min/day six times on day 1, day 3, day 7, day 15, day 30 and day 40. Lung, liver and kidney injury was measured following exposure, as well as in unexposed control rats (n = 4 at the beginning of the study). DNA strand breakage [tail moment (TMOM)] in exposed animals showed significant differences at day 1, day 4, day 7 and day 15 relative to the levels in control animals. Malondialdehyde (MDA, a lipid peroxidation product) levels increased gradually post-welding to 0.4 microM at 7 days. MDA and TMOM both reached maximum levels 7 days after the first exposure. At the start, an increasing trend in DNA strand breakage was more obvious than increases in MDA levels; MDA seemed to reflect long-term effects of exposure to welding fumes since it increased after 7 days and was sustained to 40 days in vivo. Significant differences in both MDA levels and DNA strand breakage were seen in lung, liver and kidney 40 days after the first fume inhalation. We conclude that acute exposure of rats to welding fumes causes noticeable oxidative damage and lipid peroxidation effects and that DNA damage may recover after long and repeat exposure. More chronic inhalation and low-dose studies are needed in order to further assess the effects of inhalation of welding fumes on DNA and to elucidate the possible causal mechanisms associated with the biologically damaging effects of welding fumes.

L-carnosine inhibits metastasis of SK-Hep-1 cells by inhibition of matrix metaoproteinase-9 expression and induction of an antimetastatic gene, nm23-H1

Antioxidants have been suggested to inhibit the expression of matrix metalloproteinases (MMPs), especially MMP-9, which plays a critical role in tumor metastasis. Because of its antioxidant activity and the ability to chelate divalent cations, L-carnosine (LC) was tested for inhibition of MMP-9 in a highly invasive hepatocarcinoma, SK-Hep-1 cells. We found that LC (50-1,000 microM) did not directly inhibit the activity of MMP-9 in a cell-free system. However, LC significantly inhibited the expression and activity of MMP-9 protein in SK-Hep-1 cells [inhibitory concentration of 50% (IC(50))| = 105 and 63 muM, respectively). Whereas LC did not inhibit the viability of SK-Hep-1 cells at concentrations up to 1,000 microM within 3 days of incubation, this dipeptide significantly inhibited cell migration (IC(50) = 82 microM) and invasion (IC(50) = 113 microM). LC significantly (P < 0.05) and dose dependently enhanced the expression of an antimetastatic gene, nonmetastatic cells 1, protein (nm23)-H1, at both protein and messenger ribonucleic acid (mRNA) levels. MMP-9 activity inversely correlated significantly with the expression of protein (r(2) = 0.77, P < 0.001) and mRNA (r(2) = 0.65, P < 0.001) of nm23-H1 in LC-treated cells. Thus, LC can inhibit the migration and invasion of SK-Hep-1 cells, and the effect is likely associated with upregulation of nm23-H1 and downregulation of MMP-9 expression.

Analytical analysis of modulated signal in apertureless scanning near-field optical microscopy

Eliminating background-scattering effects from the detected signal is crucial in improving the performance of super-high-resolution apertureless scanning near-field optical microscopy (A-SNOM). Using a simple mathematical model of the A-SNOM detected signal, this study explores the respective effects of the phase modulation depth, the wavelength and angle of the incident light, and the amplitude of the tip vibration on the signal contrast and signal intensity. In general, the results show that the background-noise decays as the order of the Bessel function increases and that higher-order harmonic frequencies yield an improved signal contrast. Additionally, it is found that incident light with a longer wavelength improves the signal contrast for a constant order of modulation frequency. The signal contrast can also be improved by reducing the incident angle of the incident light. Finally, it is demonstrated that sample stage scanning yields an improved imaging result. However, tip scanning provides a reasonable low-cost and faster solution in the smaller scan area. The analytical results presented in this study enable a better understanding of the complex detected signal in A-SNOM and provide insights into methods of improving the signal contrast of the A-SNOM measurement.

Effects of lycopene supplementation on plasma and tissue lycopene levels in various rodent strains

Lycopene has been shown to have various biologic effects, and rats and mice are often used for elucidating its in vivo effects and mechanisms. Here, we compared plasma and tissue lycopene levels in F344 rats, BALB/c mice, nude mice, and gerbils by oral supplementation with lycopene (20 mg/kg BW x 2d) every other morning for 10 days. We found that livers accumulated substantially more lycopene than kidneys and that the hepatic lycopene contents varied greatly in these animals, with gerbils being most efficient (1432 +/- 235 nmol/g), followed by nude mice (524 +/- 133 nmol/g), F344 rats (28 +/- 11 nmol/g), and BALB/c mice (5 +/- 2 nmol/g). Plasma lycopene concentrations also varied greatly, of which the highest was found in gerbils (667 +/- 160 nmol/L), followed by nude mice (224 +/- 51 nmol/L), then by BALB/c mice and F344 rats (198 +/- 52 and 139 +/- 41 nmol/L, respectively). Interestingly, plasma and tissue beta-carotene concentrations in these animals were markedly decreased by lycopene supplementation. To determine the steady-state levels of plasma lycopene, we fed 10 gerbils with lycopene (20 mg/kg BW x 2d) for 20 days, and we found a steady-state level of plasma lycopene between 597 to 722 nmol/L. Our results demonstrate that gerbils and nude mice are better accumulators than F344 rats and BALB/c mice, and that the former species may be more useful for studying the in vivo effects of lycopene.

Digital programmable light spectrum synthesis system using a digital micromirror device

We present a digital programmable light spectrum synthesis system based on a digital micromirror device (DMD) from Texas Instruments. A DMD pattern-scanning calibration method is developed and applied to the synthesis of various infrared C-band (1530-1565 nm) spectral profiles, including a fast programmable tunable light source with a bandwidth of approximately 3.8 nm, a square profile, a sawtooth waveform, and a triangular spectrum profile. The experimental results show that the wavelength resolution of the DMD spectrum synthesis system is approximately 0.076 nm/pixel. The proposed spectrum synthesis system has a number of key advantages, including a rapid and stable performance and multichannel compatibility. The spectrum synthesis system is suitable for various applications, including pulse shaping for coherent control and harmonic generation, a tunable light source, an equalizer for erbium-doped fiber amplifiers, and a wavelength scanner.

Synergistic DNA damage and lipid peroxidation in cultured human white blood cells exposed to 4-(methyl-nitrosamino)-1-(3-pyridyl)-1-butanone and ultraviolet A

4-(Methyl-nitrosamino)-1-(3-pyridyl)-1-butanone (NNK) is an important carcinogen in cigarette smoke, while ultraviolet (UV) irradiation from sunlight is a major factor for causing skin aging and skin cancer. However, little is known about the effects of the interaction between NNK and UV light on the induction of DNA damage and oxidative stress. In this study, we incubated human white blood cells (WBCs) with NNK, followed by irradiating the cells with ultraviolet A (UVA) (320-380 nm), and we measured DNA strand breaks (by the Comet or single-cell gel electrophoresis assay), lipid peroxidation (as thiobarbituric acid-reactive substances, TABRS), and the levels of intracellular reactive oxygen species (ROS). We found that preincubation with 1.0 mM NNK, followed by UVA irradiation (7.6 kJ/m2) synergistically increased DNA damage, lipid peroxidation, and the level of intracellular ROS in WBCs, while NNK or UVA alone had little or no effect. Electron spin resonance spectroscopic analyses showed that NNK plus UVA enhanced the UVA-induced generation of singlet oxygen but not hydroxyl radicals. In addition to ROS, bioactivation of NNK by cytochromes P450 (CYP) to form reactive NNK intermediates may also be involved in the synergistic damage to WBCs by NNK plus UVA. This is evidenced by the synergistic increase in N7-methylguanine (7-mGua), a major DNA adduct produced by NNK. Overall, the present study demonstrates that exposure of WBCs to both NNK and UVA synergistically increases DNA damage and lipid peroxidation and that such effects involve enhanced generation of ROS, especially singlet oxygen, and activation of NNK to 7-mGua by CYP. The results imply that NNK is a phototoxic agent.

Effect of dietary vitamin E and selenium on DNA damage in fresh and frozen tissues

To determine whether deficiencies of dietary vitamin E and Se can elevate background DNA damage, rats were fed diets deficient in or supplemented with vitamin E (30 and 200 mg/kg diet) and Se (0.2 mg/kg diet) for 8 weeks. DNA damage was measured using the Comet (single-cell electrophoresis) assay and 8-oxodeoxyguanosine (8-oxo-dG) in liver, kidneys, and lymphocytes. We found that a deficiency of vitamin E and/or Se for 8 weeks did not significantly increase DNA damage in freshly isolated liver, kidneys, or lymphocytes. However, deficiency of vitamin E and/or Se for 8 weeks markedly increased DNA strand breaks in frozen kidney (-80 degrees C for 72 hours) and in lymphocytes incubated overnight at 37 degrees C, both of which were effectively prevented by supplementation of Se and vitamin E. However, vitamin E at 200 mg/kg did not afford more protection than it did at 30 mg/kg). Little or no significant increase in DNA damage was found in frozen livers. These results indicate that freezing or freeze-thawing of tissues may cause oxidative damage to DNA when the tissues are deficient in a major antioxidant, and that normal levels of vitamin E (30 mg/kg diet) and Se (0.2 mg/kg diet) are sufficient to prevent the damage. Thus, our results caution against the interpretation of DNA data obtained from frozen rat tissues or cells in animal studies with dietary vitamin E or Se deficiencies.

Apoptotic markers on lymphocytes and monocytes are unchanged during single hemodialysis sessions using either regenerated cellulose or polysulfone membranes

BACKGROUND

There is an increased rate of apoptosis of peripheral blood mononuclear cells (PBMCs) in patients undergoing hemodialysis (HD), but little is known about how different dialysis membranes may contribute to the process. We, therefore, studied the influence of two different dialysis membranes on apoptotic markers during HD.

METHODS

8 healthy controls and 8 patients on regular HD 3 times per week were enrolled in this cross-controlled study. Patients received HD using polysulfone and then regenerated cellulose dialysis membranes for one week each, sequentially. Serum was collected for C-reactive protein (CRP) detection; flow cytometry with dual antibody staining was used to measure the apoptotic markers Fas (CD95), FasL (CD 178) and TNF-R2 (CD120b) in T cells (CD3+), B cells (CD19+), and monocytes (CD14+) at 0, 15, 120 and 240 min after starting HD. We also measured total leukocyte numbers and differential white cell counts.

RESULTS

Hemodialysis patients revealed lymphocytopenia, monocytopenia, higher CRP levels and higher Fas and TNF-R2 expression on lymphocytes and monocytes at baseline when compared with normal controls. Leukocyte numbers, including neutrophils, lymphocytes and monocytes, dropped significantly after 15 min of dialysis. There were no significant differences in Fas levels during hemodialysis on T and B lymphocytes or on monocytes. T lymphocyte FasL (CD 178) levels remained unchanged throughout the process. There was a significantly lower overall level of CD120b at 15 min of HD, whereas this marker was higher on monocytes after dialysis. There were no significant differences in the levels of apoptotic markers between the two membranes.

CONCLUSION

Our results suggest that uremia itself contributes to PBMC apoptosis. The two different dialysis membranes used in this study did not influence apoptotic markers on PBMCs significantly, but increased TNF-R2 expression on monocytes during a single dialysis session.

Physical and sexual violence and health care utilization in HIV-infected persons with alcohol problems

We examined interpersonal violence and its association with health care utilization and substance use severity among a cohort of 349 HIV-infected men and women with histories of alcohol problems assessed biannually up to 36 months. Data included demographics, lifetime interpersonal violence histories, age at first violence exposure, recent violence (prior six months), substance use severity and health care utilization (ambulatory visits, Emergency Department (ED) visits, hospitalizations) and adherence to HIV medication. Kaplan-Meier survival curves estimated the proportion of subjects experiencing recent violence. Generalized estimating equation regression models evaluated the relationship between recent violence, utilization and substance use severity over time, controlling for demographics, CD4 counts and depressive symptoms. Subject characteristics included: 79% male; mean age 41 years; 44% black, 33% white and 23% other. Eighty percent of subjects reported lifetime interpersonal violence: 40% physical violence alone, and 40% sexual violence with or without physical violence. First violence occurred prior to age 13 in 46%. Twenty-four (41%) of subjects reported recent violence by 24 and 36 months, respectively. In multivariate analyses, recent violence was associated with more ambulatory visits, ED visits and hospitalizations and worse substance use severity, but not medication adherence. Due to the high incidence and associated increased health care services utilization, violence prevention interventions should be considered for HIV-infected patients with a history of alcohol problems.

Lycopene inhibits cell migration and invasion and upregulates Nm23-H1 in a highly invasive hepatocarcinoma, SK-Hep-1 cells

The carotenoid lycopene has been associated with decreased risks of several types of cancer, such as prostate cancer and hepatoma. Tumor metastasis is the most important cause of cancer death. Although lycopene was shown to inhibit metastasis, the mechanism underlying this action is not well understood. Here, we tested the possibility that lycopene may inhibit cancer cell metastasis by upregulating the expression of nm23-H1, a metastasis suppressor gene, in SK-Hep-1 cells, a highly invasive hepatoma cell line, and we determined migration and invasion activities and the expression of nm23-H1 protein and mRNA. We showed that lycopene inhibited SK-Hep-1 migration and invasion in a bell-shaped manner, with the highest effect at 5 micromol/L (91 and 63% inhibition for migration and invasion, respectively; P < 0.05). At the same test level (10 micromol/L), lycopene was much more effective than beta-carotene in reducing cell invasion (by approximately 870%). In contrast to the effects on migration and invasion, lycopene enhanced nm23-H1 expression at both the protein and mRNA levels; the effects were also bell shaped, and at 5 micromol/L, lycopene enhanced nm23-H1 protein and mRNA expressions by 220 +/- 33 and 153 +/- 22% (P < 0.01), respectively. These bell-shaped effects of lycopene may be related to autoxidation of lycopene at elevated concentrations (> or =10 micromol/L). Significant correlations existed between nm23-H1 protein expression and migration (r2= 0.78, P < 0.001) and between nm23-H1 protein expression and invasion (r2= 0.84, P < 0.001) in lycopene-treated SK-Hep-1 cells. We conclude that lycopene has significant antimigration and anti-invasion activity, and that this effect is associated with its induction of nm23-H1 expression.

Recombinant human erythropoietin independence in chronic hemodialysis patients: clinical features, iron homeostasis and erythropoiesis

AIMS

Recombinant human erythropoietin (r-HuEPO) is widely used to correct renal anemia in uremic patients. Interestingly, some chronic hemodialysis (HD) patients can maintain high hemoglobin level without the need of r-HuEPO. The aim of this study is to investigate clinical features, iron metabolism and erythropoiesis of these r-HuEPO-independent HD patients.

METHODS

r-HuEPO independence was defined in dialysis patients as hemoglobin greater than 12 g/dl and no use of r-HuEPO for at least 6 months. An age- and sex-matched group was selected for comparison. Their underlying diseases, duration of hemodialysis therapy, efficacy of dialysis (Kt/V), normalized protein catabolic rate (nPCR) and body mass index (BMI) were recorded. Laboratory data including: hemoglobin, albumin, high sensitivity C-reactive protein, serum iron, total iron binding capacity, transferrin saturation, ferritin, intact parathyroid hormone, soluble transferrin receptor (sTfR), serum EPO, cortisol, testosterone, aluminum and leptin levels were measured. Renal sonography was also performed in each patient to evaluate renal cyst formation.

RESULTS

About 2.3% of all HD patients (21/888; M : F = 18 : 3) were r-HuEPO-independent. These patients had significantly longer HD duration and higher serum EPO and sTfR levels, and lower transferrin saturation rate than dependent groups. Correlation analysis revealed that hemoglobin level strongly correlated with HD duration, serum sTfR and EPO levels. Levels of sTfR were positively related with serum EPO levels and BMI. Multivariate regression analysis showed that level of sTfR was the only independent factor related to r-HuEPO independence.

CONCLUSION

R-HuEPO independence is rare among chronic hemodialysis patients. Factors contributing to this dependence are complex and multiple. Level of serum sTfR parallels erythropoiesis and is the most significant factor associated with r-HuEPO independence in chronic HD patients.

Use of whole blood directly for single-cell gel electrophoresis (comet) assay in vivo and white blood cells for in vitro assay

The present study investigated the use of whole blood from humans and rats directly for single-cell gel electrophoresis (comet) assay. As little as 20 microl of whole blood was sufficient for comet assay, and the comet images obtained from whole blood were not different from those obtained from isolated lymphocytes. The DNA remained intact up to 4 h at 4 degrees C after isolation and had no observable strand breakage, when whole blood was cryopreserved (at -80 degrees C) in 10% pre-cooled DMSO up to 60 days. To demonstrate that the whole-blood technique could be applied to in vivo studies, we injected rats with a known carcinogen Fe/NTA and measured DNA strand breaks in whole blood in comparison with isolated lymphocytes. We showed that Fe/NTA injection resulted in similar extent of DNA strand breakage in both whole blood and lymphocytes, indicating that whole-blood method can be used for in vivo genotoxic studies. One disadvantage of the whole-blood technique is that whole blood cannot be used for in vitro studies because of the interferences from red blood cell (RBC) components. However, this problem can be overcome by prior hemolysis of RBCs and a brief centrifugation to obtain white blood cells (WBCs), which can then be used for in vitro incubation with genotoxic compounds before comet assay. Overall, this whole-blood technique for comet assay is expected to provide a simple, rapid, and cost-effective alternative for the existing comet assay using isolated lymphocytes in situations such as when time and cost are limiting factors.

A downstream algorithm based on extended gradient vector flow field for object segmentation

For object segmentation, traditional snake algorithms often require human interaction; region growing methods are considerably dependent on the selected homogeneity criterion and initial seeds; watershed algorithms, however, have the drawback of over segmentation. A new downstream algorithm based on a proposed extended gradient vector flow (E-GVF) field model is presented in this paper for multiobject segmentation. The proposed flow field, on one hand, diffuses and propagates gradients near object boundaries to provide an effective guiding force and, on the other hand, presents a higher resolution of direction than traditional GVF field. The downstream process starts with a set of seeds scored and selected by considering local gradient direction information around each pixel. This step is automatic and requires no human interaction, making our algorithm more suitable for practical applications. Experiments show that our algorithm is noise resistant and has the advantage of segmenting objects that are separated from the background, while ignoring the internal structures of them. We have tested the proposed algorithm with several realistic images (e.g., medical and complex background images) and gained good results.

Emergency contraception: prescribing practices of general internists compared with other primary care physicians

Primary care physicians of all specialties should be familiar with prescribing emergency contraception (EC). We conducted a mail survey of 282 randomly sampled physicians in general internal medicine (31%), family medicine (34%) and obstetrics-gynecology (35%). Experience with prescribing EC significantly differed by specialty (63% of general internists, 76% of family physicians, and 94% of obstetrician-gynecologists, p < 0.0001). Controlling for year of graduation, gender, religion and practice location, family physicians [adjusted odds ratio (OR): 2.5, 95% confidence interval (CI): 1.2-5.2] and obstetrician-gynecologists (adjusted OR: 11.2, 95% CI: 4.0-31.3) were still significantly more likely to have ever prescribed EC than general internists. Efforts to increase awareness and knowledge of EC should be aimed at general internists since they provide primary care for many reproductive age women.

A defoaming agent should be used with pronase premedication to improve visibility in upper gastrointestinal endoscopy

BACKGROUND AND STUDY AIMS

The study tested whether pronase can improve endoscopic visibility and alter the accuracy of the CLO test for H. pylori detection.

PATIENTS AND METHODS

A total of 160 patients were randomly assigned to receive one of five premedications for endoscopy: group A: dimethylpolysiloxane (DMPS) alone; group B: DMPS plus water (up to 100 ml); group C: pronase only, with 100 ml water; group D: pronase and sodium bicarbonate plus water up to 100 ml; group E: pronase, sodium bicarbonate, and DMPS, plus water up to 100 ml. Endoscopists, who were unaware of the premedication method administered, assessed visibility scores (range 1 - 4) for the antrum, lower gastric body, upper gastric body, and fundus. The higher the score, the less clear the visibility. The sum of scores from the four locations was defined as the total visibility score. A CLO test was also done during the endoscopy. One week after their endoscopy, patients in groups C, D, and E were scheduled for a (13)C-urea breath test (UBT).

RESULTS

Group E patients had a significantly lower total visibility score than those in the other four groups ( P < 0.05). Groups C and D had higher total visibility scores than the other three groups ( P < 0.05). The scores did not significantly differ between groups A and B. Based on the UBT results, the sensitivity and specificity of the CLO test were 92.6 % and 96.2 %, respectively.

CONCLUSIONS

Premedication as in group E provided the clearest endoscopic visibility. Without the application of DMPS, pronase alone cannot improve endoscopic visibility. Pronase does not influence H. pylori identification using the CLO test.

Simple cryoprotection and cell dissociation techniques for application of the comet assay to fresh and frozen rat tissues

The single-cell gel electrophoresis (comet) assay has been widely used for genotoxicity studies in cell cultures, but its use in solid tissues is hindered by problems in isolation of cells and in cryopreservation techniques. Here, we used minced liver tissues from rats to compare a homogenization technique for isolation of nuclei with a collagenase digestion method (300 units/g liver at 37 degrees C for 20 min) for isolation of intact cells for subsequent comet assay We found that collagenase digestion was preferred to the homogenization technique in fresh tissues, but neither method prevented the extensive DNA damage caused by cryopreservation (-85 degrees C for 72 h). To minimize this damage, minced liver (1.0 g) and kidney (0.5 g) tissues were added to 20 ml of pre-cooled 10% glycerol or 10% dimethylsulfoxide (DMSO). We showed that cryoprotection with DMSO (-85 degrees C for 72 h and 3 weeks), and to a slightly lesser extent with glycerol (72 h), followed by collagenase digestion led to satisfactory recovery of liver cells with little or no DNA strand breakage. We then used DMSO as a cryoprotective agent to optimize the amount of collagenase and its incubation time in frozen liver and kidney tissues. We showed that the collagenase digestion at 150units/g liver and 300units/g kidney for 10 min produced highest cell numbers and minimal DNA strand breaks. We also validated these procedures by injection (i.p.) of rats with a known renal carcinogen, ferric nitrilotriacetate (Fe/NTA). We showed that Fe/NTA strongly induced DNA strand breaks in both rat liver and kidney, while no DNA strand breakage occurred in these tissues from the control rats. In addition, no significant differences in strand breaks were found between fresh tissues and tissues treated with DMSO during freezing at - 85 degrees C for 72 h. Thus, the cryoprotection and the cell dissociation techniques developed here are satisfactory for preparing both fresh and frozen tissues for comet assay. These simple techniques are expected to expand greatly the usefulness and efficacy of the assay.

Pretreatment gastric histology is helpful to predict the symptomatic response after H. pylori eradication in patients with nonulcer dyspepsia

This study aimed to test whether pretreatment gastric pathology in H. pylori-infected nonulcer dyspepsia (HpNUD) patients is relevant to and predictive of the symptomatic response after H. pylori eradication. Anti-H. pylori triple therapy was administered to 250 HpNUD patients, enrolled as the therapy group. In addition, 60 patients were enrolled as the control group, in which omeprazole was an alternatives to the triple therapy. Pretreatment gastric histology was evaluated thoroughly by the updated Sydney system. A [13C] urea breath test was also performed to evaluate the H. pylori eradication two months and 12 months later. For each patient, the baseline, month 2, and month 12 symptom scores were assessed for the month 2 or month 12 residual symptom ratio (RSR-2m or RSR-12m), calculated from: 100% x month 2 or month 12 score/baseline score. Based on either RSR-2m or RSR-12m, patients were categorized as good response (RSR < 50%), moderate response (50-70%), and poor response (> 70%) subgroups in both therapy and control groups to define the short-term and long-term symptomatic responses. Patients with successful H. pylori eradication in the therapy group showed a higher incidence of good symptomatic response (RSR < 50%) than those from the control group (month 2: 30.3 vs 12%, P < 0.05; month 12: 34.7 vs 17.1%, P < 0.05). Univariate and multivariate analysis disclosed that patients with a higher acute inflammation score (AIS) and the lowest incidence of lymphoid follicles (LF) at pretreatment gastric histology are predisposed to having a good symptom response after H. pylori eradication (P < 0.05). For HpNUD patients who have an AIS of more than three and an absence of LF at gastric histology, more than 85% had good short-term (month 2) and long-term (month 12) symptomatic relief after H. pylori eradication. In conclusion, nearly 30% of HpNUD patients can obtain symptomatic relief following H. pylori eradication. The pretreatment gastric histology of HpNUD can be helpful to monitor the symptomatic response after H. pylori eradication.

Solid-state trans-cis isomerization of captopril determined by thermal Fourier transform infrared (FT-IR) microspectroscopy

Thermal Fourier transform infrared (FT-IR) microspectroscopy was used to investigate the conformational isomerization of captopril in the solid state. The result indicates that the IR peak intensity of captopril for original bands decreased dramatically at 102 degrees C, but for new bands it increased with the rise of temperature. The frequency of C=O stretching mode for carboxylic acid and for amide was located at a higher wavenumber of 1747 cm(-1) and at a lower frequency of 1591 cm(-1) as compared with the general compound, suggesting the existence of trans isomer of captopril in the solid state by intramolecular hydrogen bonding. Beyond 102 degrees C, several new bands at 1720, 1645, and 1610 cm(-1) were observed with the rise of temperature, indicating the coexistence of a cis isomer. However, the cis isomer could transform gradually to the trans isomer after cooling. The thermodynamics of equilibrium mixture of cis/trans isomers were also studied. The trans isomer was more stable than the cis isomer, but the cis isomer was favored at the higher temperature.

Differential optical fiber refractometer based on a path-matching differential interferometer with temperature compensation

We present a new approach for the development of a highly stable optical fiber refractometer based on a path-matching differential interferometer. Exploiting a single-channel phase tracker and new synthetic heterodyne demodulations, one can eliminate the thermal drift on a piezoelectric transducer stack as a phase modulator by subtraction. A transducer in a differential Fabry-Perot refractometer is designed to compensate for the thermal effects not only from thermal expansion but also from the thermo-optic effect. The experimental data show that the refractive-index change in the sensing system can be kept at a level of approximately 5 x 10(-4) without serious variations for a 1-h period of long-term monitoring associated with a temperature variation of from 25 to 50 degrees C. Accordingly, the proposed new system can be easily implemented and used as a long-term monitoring system for medical care applications such as monitoring patients during drug injection.

Ranitidine bismuth citrate or omeprazole-based triple therapy for Helicobacter pylori eradication in Helicobacter pylori-infected non-ulcer dyspepsia

AIM

To test the eradication rate of Helicobacter pylori by ranitidine bismuth citrate-based triple therapy, and evaluate the symptomatic response of Helicobacter pylori eradication therapy for non-ulcer dyspepsia.

METHODS

A total of 59 consecutive Helicobacter pylori infected non-ulcer dyspepsia patients were randomly selected to receive either one of two triple therapy regimens, including metronidazole, amoxycillin plus ranitidine bismuth citrate (RAM group) or omeprazole (OAM group). To determine the success of eradication, patients underwent the 13C-urea breath test, 6 weeks and one year after treatment. The dyspeptic symptom scores were also assessed at the time of enrolment, 6 weeks and one year after treatment.

RESULTS

Per-protocol and intention-to-treat eradication rates were 77.7% and 70% in RAM group and 83.8% and 68.9% in OAM group (p = non significant). At both the 6th week and at the first year after treatment, the mean symptom scores were lower than pre-treatment scores in the study population, regardless of whether treatment was successful or not. However, patients, whether eradicated successfully or not-eradicated, presented similar 6-week and 1-year scores.

CONCLUSIONS

One-week RAM triple therapy, which is cheaper than the OAM regimen, is a relatively effective alternative regimen for Helicobacter pylori eradication in Taiwanese. Triple therapy for Helicobacter pylori eradication was not the whole management for the relief of dyspeptic symptoms of non-ulcer dyspepsia patients.

Construction of a tagging system for subcellular localization of proteins encoded by open reading frames

We have previously characterized a monoclonal antibody (SC1D7) that is directed to maltose-binding protein (MBP) of Escherichia coli and other closely related enteric bacteria. SC1D7 does not cross-react with proteins in eucaryotes and appears to be a highly specific tool in immunochemical analyses. To better map the epitope, we took advantage of an available plasmid, pMAL-c2, that encodes the E. coli MBP-coding sequence and constructed plasmids to express MBP fragments. A construct containing the N-terminal portion of MBP does not react with SC1D7, whereas a second construct expressing glutathione S-transferase fused with the C-terminal half of MBP does react with SC1D7. To precisely define the epitope, random peptides displayed on M13 were used to react with SC1D7. Sequences of reactive peptides were aligned, and a consensus sequence of XDXRIPX was deduced. This sequence matches MBP with an amino acid stretch of KDPRIAA. To consolidate the mapping result, a sequence encoding this epitope was inserted into an expression vector and the resulting recombinant protein did react with SC1D7. Thereafter, this epitope was incorporated into a eucaryotic expression plasmid containing a previously defined hepatitis delta virus epitope for protein tagging. This two-epitope-tagging vector is useful in various molecular analyses. We demonstrate its usage for localization of a bacterial virulence factor in host cells. This vector should be applicable for high-throughput characterization of new open reading frames found in genome sequencing.

Laser photoablation of experimental post-infarction ventricular tachycardia guided by three dimensional activation mapping

BACKGROUND AND OBJECTIVE

The purpose of this study was to evaluate the efficacy of epicardially delivered laser energy to ablate induced ventricular tachycardia in a post-infarction canine model.

STUDY DESIGN/MATERIALS AND METHODS

In 13 canines, the left anterior wall myocardial infarction was created. Five days later, 240 plunged electrodes were inserted into the heart. Three-dimensional ventricular activation sequences were analyzed on line by a computerized mapping system.

RESULTS

Sixteen sustained monomorphic ventricular tachycardias were reproducibly induced in 10 canines. Epicardially contacted Nd:YAG laser irradiated the areas of the final pathway in macro-reentrant activation and the impulse origin in focal excitation. Linear photocoagulation lesions (11-16 x 50-72 mm) were created. Seven macro-reentrant circuits and six of nine focal origins were eliminated (success rate 81%). Pathology showed that laser photocoagulation involved all surviving subepicardial and intramural fibers.

CONCLUSION

Epicardially delivered laser energy in conjunction with electrical activation mapping has a high probability of ablating post-infarction ventricular tachycardia.

Carbon urea breath test is not as accurate as endoscopy to detect Helicobacter pylori after gastrectomy

BACKGROUND

This study was conducted to determine (1) whether Helicobacter pylori infection decreases in conjunction with time elapsed after gastrectomy and (2) the diagnostic efficacy of (13)C urea breath test (UBT) for H pylori in patients after gastrectomy.

METHODS

From January 1997 to June 1998, 86 patients who had undergone gastrectomy and 180 patients with dyspepsia without gastrectomy were enrolled. A UBT for the analysis of excess (13)CO(2)/(12)CO(2) ratio (ECR) was obtained for each patient. Each patient also underwent endoscopy to obtain gastric biopsies for histology and H pylori culture. The presence of H pylori by either histology or culture served as the standard to test the efficacy of UBT. The 86 patients with a prior gastrectomy were categorized into 3 subgroups (I, less than 1 year; II, 1 to 3 years; III, greater than 3 years), according to the interval between surgery and UBT. The initial H pylori status of these 86 patients was determined by histologic evaluation of the resected stomach.

RESULTS

At trial initiation, the postgastrectomy group had a lower H pylori infection rate (52.3%) as compared with the dyspeptic control group (80%). The initial H pylori status among subgroups I, II, and III was similar. There was a trend for the presence of H pylori in the stomach to decrease with increasing time elapsed after surgery (I to III: 68.8%, 48.3%, 36%, respectively; p < 0.05). The maximum UBT sensitivity and specificity achieved were 82.2% and 87.8% in the gastrectomy group and 97.2% and 96.3% in the dyspeptic group, with cutoff points of 2.5 and 4.0, respectively.

CONCLUSION

The prevalence of H pylori diminishes with time elapsed after gastrectomy. UBT for detection of H pylori is more effective in patients without prior gastrectomy than in patients who have undergone gastrectomy and is less effective than endoscopy for patients who have had a gastrectomy.