Protective effect of oleanolic acid against beta cell dysfunction and mitochondrial apoptosis: crucial role of ERK-NRF2 signaling pathway

Pancreatic beta cell dysfunction is a hallmark of diabetes. Our previous results have shown that oleanolic acid (OA) has anti-diabetic potential. However, there is little literature reporting the effect of OA on beta cell dysfunction. The present study was designed to investigate the protective effect of OA against lipotoxicity and the underlying mechanisms. Lepr (db/db) diabetic mice were subjected to fasting blood glucose measurement, intraperitoneal glucose tolerance test after the administration of OA for two weeks. Histopathological observation was conducted by HE staining and transmission electron microscopy assay. Pancreatic islets were isolated from db/db diabetic mice and C57BL/6J mice. Palmitic acid (PA) was used to induce lipotoxicity in vitro. Apoptosis was evaluated in pancreatic islets in diabetic mice and in isolated pancreatic islets and beta-TC3 cells by TUNEL assay. Cellular ATP content, mitochondrial function and redox balance were examined. Phosphorylation of c-Jun NH2-terminal kinase (JNK) and extracellular signal-regulated kinase (ERK) and the activation of nuclear erythroid factor 2 p45-related factor 2 (Nrf2) signaling were evaluated by western blotting. In db/db mice, OA significantly protects beta cell function against lipotoxicity, evidenced by inhibition of apoptosis and improvement of glucose tolerance. In cells, OA administration may protect against PA-induced apoptosis and decrease of GSIS, in which process the activation of Nrf2 is essential. Once Nrf2 is activated, OA could induce GCLc expression, promote the production of GSH, and thus inhibit JNK phosphorylation and solid the antioxidant defense of mitochondria, leading to the inhibition of mitochondrial apoptosis. ERK signaling pathway is responsible for OA-induced activation of Nrf2 and the protective effect of OA. Overall, our study enhances the understanding of the protective effect of OA on beta cell and provides clues for further studies on the underlying mechanisms.

Biochemical study of retired pentachlorophenol workers with and without following dietary exposure to PCDD/Fs

PCDD/Fs are found as impurities in commercial pesticide sodium pentachlorophenol (Na-PCP) salt. We compared, using multivariate logistic regression analysis adjusted for confounding factors, serum PCDD/F levels and biochemical examinations of retired Na-PCP workers and other inhabitants living near a closed Na-PCP plant that discharged PCP-contaminated wastewater into a nearby pond in Tainan, Taiwan. In this cross-sectional study from October 2006 through May 2009, 1167 participants were divided into groups according to their occupational (retired Na-PCP plant workers versus other residents) and dietary exposure (eating polluted fish versus not eating polluted fish) to PCDD/Fs, and a general population from a large-scale survey. Serum PCDD/F levels were significantly different between these groups (range: from 22.9±10.0pg WHO(98)-TEQ(DF) g(-1) lipid in the general population to 109.6±94.5pg WHO(98)-TEQ(DF) g(-1) lipid in retired Na-PCP workers eating polluted seafood; P(trend)<0.001). Distinct patterns of PCDD/Fs congener profiles, showing a significantly higher proportion of 1,2,3,7,8-PeCDD, 1,2,3,6,7,8-HxDD, and less 2,3,4,6,7,8-HpCDF, OCDF, were also found among workers and residents with different serum PCDD/F levels versus the general population. After adjusting for confounding factors, glucose (adjusted odds ratio [AOR] 7.22 [95% CI: 4.04-12.90]), triglycerides (AOR 4.31 [95% CI: 2.57-7.22]), blood urea nitrogen (AOR 2.90 [95% CI: 1.58-5.33]), creatine (AOR 5.83 [95% CI: 1.12-30.30]) and total protein (AOR 3.74 [95% CI: 1.91-7.31]) levels in retired workers were significantly higher than in the reference group. Occupational exposure to PCDD/Fs is associated with biochemical abnormalities that may persist for years after serum PCDD/F levels have declined.

Identification of sex-specific polymorphic sequences in the goat amelogenin gene for embryo sexing

Amelogenin (AMEL) is a conserved gene located on the sex chromosomes of mammals. It is involved in the formation of enamel, which is the hard, white material that forms the protective outer layer of each tooth. In this study, we first cloned and determined the intron sequences of the goat AMELX and AMELY genes from female and male ear tissues. The polymorphic AMEL alleles were further analyzed by PCR-based RFLP and Southern blot hybridization analyses. Results showed that intron 5 nucleotide sequences of the goat AMELY gene contains multiple deletions/insertions and shares only 48.5% identity to intron 5 of the goat AMELX gene. Based on the polymorphic AMEL intron sequences, a set of sex-specific triplex primers was designed to PCR amplify a single fragment of 264 bp from the X chromosome of female goats and 2 fragments of 264 and 206 bp from the X and Y chromosomes, respectively, of male goats. An increased sensitivity for sex determination was reached with a single blastomere at the blastula stage isolated from goat embryos. A total of 43 goat embryos were used to estimate a 100% accuracy rate of this method confirmed by chromosomal karyotyping and live births. The embryo sexing technique has been successfully applied in different strains of goats including Alpine, Saanen, Nubian, and Taiwan goats.

Application of high-frequency ultrasound for the detection of surgical anatomy in the rodent abdomen

Rats are used extensively in abdominal disease research. To monitor disease progress in vivo, high-frequency ultrasound (HFU) can be a powerful tool for obtaining high-resolution images of biological tissues. However, there is a paucity of data regarding the correlation between rat anatomy and corresponding HFU images. Twenty-four adult male Sprague-Dawley (SD) rats underwent abdominal scans using HFU (40 MHz) surgical procedures to identify abdominal organs and major vessels as well as in situ scanning to confirm the imaging results. The results were compared with those of human abdominal organs in ultrasonographic scans. The rat liver, paired kidneys, stomach, intestines, and major blood vessels were identified by HFU and the ultrasonic morphologies of the liver and kidneys showed clear differences between rats and humans. Clinically relevant anatomical structures were identified using HFU imaging of the rat abdomen, and these structures were compared with the corresponding structures in humans. Increased knowledge with regard to identifying the anatomy of rat abdominal organs by ultrasound will allow scientists to conduct more detailed intra-abdominal research in rodents.

Abstract P6-04-03: Unique Recurrent Signature and Signaling Pathway of Asian Triple Negative Breast Cancer

Background: Triple-negative (TN) breast cancer, a lack of understanding of the driving oncogenic mechanisms and thus therapeutic targets has left this an understudied ‘Cinderella’ in breast cancer phase III trials. No publication has been addressed on recurrent signature and pathway signaling of Asia TN breast cancer. The gene expression difference between Eastern and Western breast cancer is also unknown.

Material and Methods: 185 represent breast cancer cases including 43 Luminal A, 31 Luminal B, 35 Her-2 type, 51 TN and remaining 25 unclassified were selected from our tissue bank. Using Agilent microarray chip, we explored gene expression profile of these patients. For direct western and eastern comparison, 195 Caucasian breast cancer gene expression profile using the same Agilent platform were downloaded wedsite. In TN breast cancers, excluding 3 cases with stage IV disease at diagnosis, 11 patients developed distant recurrence during follow up. For these 48 patients, recurrent model was established by two step Cox proportional hazard regression: in first step, 35 candidate recurrent genes were selected from 20173 genes with significant level less than 0.0005. Then, we randomly choose 4 genes from the 35 candidate genes to construct recurrent model to avoid overfitting. TN related signaling pathways were discovered using Ingenuity Pathway Analysis(IPA) and GSEA(Gene Set Enrichment Analysis).

Results: Using non-supervised analysis, we found the eastern and western breast cancers have their own TN cancer clustering phenomenon, obviously in a different cluster.

This represented the eastern and western breast cancer have fundamental differences. The model including PKRAG3, MORC2, GRB7, FAM43A showed the best recurrence prediction power in 52360 combination models(R Square 0.71). This model was cross-validated by Vector machine(SVM) with leave one out setting. The overall accuracy was 87.5%. The sensitivity and specificity were 72.7% and 91.9%. This model was failed to predict recurrence in Luminal or Her-2 Molecular type. With IPA, we found 9 TN related pathway. The top two were cAMP-mediated and Ephrin Receptor signaling. 10 pathways were found from GSEA. Nicotinate, Olfactory transduction and Axon guidance were on the top of the list. Further functional study is on going.

Discussion: This is the first study to compare the gene expression between eastern and western breast cancer on the same gene expression platform. The gene expression profile is fundamentally different between eastern and western TN breast cancers. This phenomenon infers different biological behavior and drug sensitivity may exist among different ethnic groups. We established recurrent prediction model unique for Taiwanese TN breast cancer by four genes with high accuracy. We can develop commercial recurrent kit after further clinical validation.

Figure available in online version.

Interrelationship between exposure to PCDD/Fs and hypertension in metabolic syndrome in Taiwanese living near a highly contaminated area

Metabolic syndrome (MetS) consists of a constellation of metabolic abnormalities that confer increased risk of cardiovascular disease. There is a positive correlation between exposure to persistent organic pollutants and MetS. We examine the association between PCDD/Fs and MetS components in 1490 non-diabetic persons living near a highly dioxin-contaminated area. We used factor analysis, with a set of core variables considered central features of MetS and PCDD/Fs, to group similar risk factors. Serum PCDD/Fs were positively and significantly correlated with the number of MetS components. Four risk factors-lipidemia, blood pressure, body size, and glycemia-accounted for 72.6% of the variance in the 10 core factors, and PCDD/Fs were linked to MetS through shared correlations with high blood pressure. After adjusting for confounding factors, we found that diastolic blood pressure (β=0.018; p=0.006), glucose (β=0.013; p=0.046), and waist circumference (β=0.721; p=0.042) significantly increased with increasing serum PCDD/F levels. We found significant trends for associations between metabolic syndrome and serum low-chlorinated PCDD/Fs. The highest quintiles of 2,3,4,7,8-PeCDF, 1,2,3,6,7,8-HxCDF and 2,3,7,8-TCDD had the top three adjusted ORs (95% CI) of 3.5 (1.9-6.3), 2.9 (1.7-4.9) and 2.8 (1.6-4.9), respectively. We also found a slight monotonic relationship between serum PCDD/Fs and the prevalence of MetS, especially when the serum dioxin level was higher than 25.4pg WHO(98)-TEQ(DF)g(-1) lipid (the fourth Quintile). We hypothesize that high-dose exposure to PCDD/Fs is a blood pressure-related factor that raises MetS risk.

Using autocloning effects to develop broad-bandwidth, omnidirectional antireflection structures for silicon solar cells

In this study, we used the autocloning effect on pyramid structures to develop broad-bandwidth, omnidirectional antireflection structures for silicon solar cells. The angular dependence of reflectance on several pyramid structures was systematically investigated. The deposition of three-layer autocloned films reduced the refractive index gap between air and silicon, resulting in an increase in the amount of transmitted light and a decrease in the total light escaping. The average reflectance decreased dramatically to ca. 2-3% at incident angles from 0 to 60° for both sub-wavelength- and micrometer-scale pyramid structures. The measured reflectance of the autocloned structure was less than 4% in the wavelength range from 400 to 1000 nm for incident angles from 0 to 60°. Therefore, the autocloning technique, combined with optical thin films and optical gradient structures, is a practical and compatible method for the fabrication of broad-bandwidth, omnidirectional antireflection structures on silicon solar cells.

Abstract 2460: Epstein-Barr virus infection confer stress-resistant property in immortalized nasopharyngeal epithelial cells

Epstein-Barr virus (EBV) infection has been postulated to be an early event involved in the pathogenesis of NPC. The lack of representative premalignant nasopharyngeal epithelial cell system for EBV infection has hampered research investigation into the regulation and involvement of EBV infection in NPC pathogenesis. We have compared the efficiency of EBV infection in nasopharyngeal epithelial cells with different biological properties including immortalized, primary and cancerous nasopharyngeal epithelial cells. EBV infection could be achieved in all the nasopharyngeal epithelial cells examined with variable infection rate. TGF-β effectively enhanced EBV infection into nasopharyngeal epithelial cells both in the immortalized and primary nasopharyngeal epithelial cells. Stable infection of EBV was achieved in a telomerase-immortalized nasopharyngeal epithelial cell line, NP460hTert. The expression pattern of EBV-encoded genes and biological properties of this EBV infected cell line upon long term propagation were monitored. The EBV-infected nasopharyngeal epithelial cells acquired anchorage independent growth in soft-agar and exhibited invasive growth properties upon prolonged propagation. A distinguish feature of this EBV-infected nasopharyngeal epithelial cell model was its enhanced ability to survive under growth factor and nutrient starvation. This was evidenced by the suppressed activation of apoptotic markers and sustained activation of pAkt of EBV-infected cells compared to control cells under nutrient starvation. Examination of cytokine profiles of EBV-infected NP460hTert cells to nutrient and growth factor deprivation revealed upregulation expression of MCP-1 and GRO-α. The establishment of a stable EBV infection model of premalignant nasopharyngeal epithelial cells will facilitate research investigation into the pathogenic role of EBV in NPC development.

Acknowlegement: The authors wish to acknowlege the funding support from the Research Grant Council (Hong Kong) and the Area of Excellence on Nasopharyangeal Carcinoma Research Center (Hong Kong).

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 2460.

Nestin is essential for zebrafish brain and eye development through control of progenitor cell apoptosis

Background

Nestin is expressed in neural progenitor cells (NPC) of developing brain. Despite its wide use as an NPC marker, the function of nestin in embryo development is unclear.

Methodology/Principal Findings

As nestin is conserved in zebrafish and its predicted sequence is clustered with the mammalian nestin orthologue, we used zebrafish as a model to investigate its role in embryogenesis. Injection of nestin morpholino (MO) into fertilized eggs induced time- and dose-dependent brain and eye developmental defects. Nestin morphants exhibited characteristic morphological changes including small head, small eyes and hydrocephalus. Histological examinations show reduced hind- and mid-brain size, dilated ventricle, poorly organized retina and underdeveloped lens. Injection of control nestin MO did not induce brain or eye changes. Nestin MO injection reduced expression of ascl1b (achaete-scute complex-like 1b), a marker of NPCs, without affecting its distribution. Nestin MO did not influence Elavl3/4 (Embryonic lethal, abnormal vision, Drosophila-like 3/4) (a neuronal marker), or otx2 (a midbrain neuronal marker), but severely perturbed cranial motor nerve development and axon distribution. To determine whether the developmental defects are due to excessive NPC apoptosis and/or reduced NPC proliferation, we analyzed apoptosis by TUNEL assay and acridine orange staining and proliferation by BrdU incorporation, pcna and mcm5 expressions. Excessive apoptosis was noted in hindbrain and midbrain cells. Apoptotic signals were colocalized with ascl1b. Proliferation markers were not significantly altered by nestin MO.

Conclusion/Significance

These results suggest that nestin is essential for zebrafish brain and eye development probably through control of progenitor cell apoptosis.

Mice deficient in dihydrolipoyl succinyl transferase show increased vulnerability to mitochondrial toxins

The activity of a key mitochondrial tricarboxylic acid cycle enzyme, alpha-ketoglutarate dehydrogenase complex (KGDHC), declines in many neurodegenerative diseases. KGDHC consists of three subunits. The dihydrolipoyl succinyl transferase (DLST) component is unique to KGDHC. DLST(+/-) mice showed reduced mRNA and protein levels and decreased brain mitochondrial KGDHC activity. Neurotoxic effects of mitochondrial toxins were exacerbated in DLST(+/-) mice. MPTP produced a significantly greater reduction of striatal dopamine and tyrosine hydroxylase-positive neurons in the substantia nigra pars compacta of DLST(+/-) mice. DLST deficiency enhanced the severity of lipid peroxidation in the substantia nigra after MPTP treatment. Striatal lesions induced by either malonate or 3-nitropropionic acid (3-NP) were significantly larger in DLST(+/-) mice than in wildtype controls. DLST deficiency enhanced the 3-NP inhibition of mitochondria enzymes, and 3-NP induced protein and DNA oxidations. These observations support the hypothesis that reductions in KGDHC may impair the adaptability of the brain and contribute to the pathogenesis of neurodegenerative diseases.

Genetic variability at the pig SLA complex in U.S. breeds of pigs

Lymphocytes from 90 mature pigs and 548 growing pigs from 65 litters were screened with cytotoxic antibodies against swine lymphocyte antigens. Pigs included in the survey were from the Chester White, Duroc, Hampshire, Landrace and Yorkshire breeds. Significant differences between breeds were found in the frequency of the three haplotypes tested. Such differences may provide the genetic variability needed to determine associations between disease susceptibility and the pig's major histocompatibility gene complex.

Extraordinary transmittance in three dimensional crater, pyramid, and hole-array structures prepared through reversal imprinting of metal films

We used a reversal imprinting-in-metal (RIM) process to fabricate various three-dimensional (3D) metal structures under low pressure. Molds featuring different shapes were used to pattern various subwavelength metal structures, including pyramidal, hole-array, and crater-like structures. Refractive index matching and cavity effects both enhanced the degree of transmission of these structured metal films. The crater-like structure appears to be a promising material because of the unique properties imparted by the elongated and gradually tapering spacing of its cavities. From both near-field simulations and experimentally obtained optical spectra, we found that the cavity effect in the crater-like structure led to significantly enhanced transmission of the optical intensity. Thus, this RIM process allows the ready fabrication of various two- and three-dimensional metallic structures for use in surface plasmon-based devices.

Oxidative degradation and associated mineralization of catechol, hydroquinone and resorcinol catalyzed by birnessite

Abiotic degradation and mineralization of catechol, hydroquinone, and resorcinol catalyzed by birnessite (delta-MnO2) was investigated. Studies were carried out by monitoring changes of pE versus time and pH versus time of the reaction systems during the initial 10 h reaction period and release of CO2 and associated reactions at the end of a 90 h reaction period. The reactions under anoxic condition were compared with aeration condition. The reactions were carried out in suspensions at initial pH of 6.0 under air and N2 atmosphere at room temperature and free of microbial activity. These results indicated that kinetic-related changes of pE versus time and pH versus time were dependent on structural characteristics of phenolic compound and aeration or anoxic condition in the reaction system. The sequence of the mineralization of phenolic compounds catalyzed by delta-MnO2 in presence of air expressed by CO2 release was catechol > hydroquinone > or = resorcinol and the differences were significant. However, under an N2 atmosphere the amounts of CO2 released were drastically reduced with insignificant differences among the three reaction systems. Further, phenolic compound degradations, dissolved and adsorbed Mn, and oxidation state of Mn in delta-MnO2 were also determined to elucidate the catalytic efficacy mediated by both O2 and delta-MnO2 in the reaction systems.

Using direct nanoimprinting of ferroelectric films to prepare devices exhibiting bi-directionally tunable surface plasmon resonances

In this paper, we describe an imprint method for the fabrication of bi-directionally tunable surface plasmon resonance (SPR) filters. A periodic metal/ferroelectric film stack exhibiting SPR phenomena was directly imprinted using a sharp mold without the need for a polymer-based resist. Both the refractive index of the surrounding lead zirconate titanate (PZT) films and the period of the textured PZT/metal/PZT structure were dependent upon both the absolute value and sign of the applied potential. The SPR wavelength of the PZT/gold/PZT-based tunable filter varied over a range of greater than 100 nm when applying potentials ranging from 0 to -15 V. This imprinting method has great potential for use in the fabrication of tunable optical filters without the need for complicated processes or specific materials.

Developmental gene regulatory networks in the zebrafish embryo

The genomic developmental program operates mainly through the regulated expression of genes encoding transcription factors and signaling pathways. Complex networks of regulatory genetic interactions control developmental cell specification and fates. Development in the zebrafish, Danio rerio, has been studied extensively and large amounts of experimental data, including information on spatial and temporal gene expression patterns, are available. A wide variety of maternal and zygotic regulatory factors and signaling pathways have been discovered in zebrafish, and these provide a useful starting point for reconstructing the gene regulatory networks (GRNs) underlying development. In this review, we describe in detail the genetic regulatory subcircuits responsible for dorsoanterior-ventroposterior patterning and endoderm formation. We describe a number of regulatory motifs, which appear to act as the functional building blocks of the GRNs. Different positive feedback loops drive the ventral and dorsal specification processes. Mutual exclusivity in dorsal-ventral polarity in zebrafish is governed by intra-cellular cross-inhibiting GRN motifs, including vent/dharma and tll1/chordin. The dorsal-ventral axis seems to be determined by competition between two maternally driven positive-feedback loops (one operating on Dharma, the other on Bmp). This is the first systematic approach aimed at developing an integrated model of the GRNs underlying zebrafish development. Comparison of GRNs' organizational motifs between different species will provide insights into developmental specification and its evolution. The online version of the zebrafish GRNs can be found at http://www.zebrafishGRNs.org.

RAGE upregulation and nuclear factor-kappaB activation associated with ageing rat cardiomyocyte dysfunction

Evidence suggests that ageing is a major risk factor for cardiac dysfunction. Interactions between advanced glycation endproducts (AGEs) and the receptor for AGEs (RAGE) are known to cause chronic cellular activation, including activation of nuclear factor-kappaB (NF-kappaB), which has been implicated as a causal factor in the ageing process. To assess whether cardiomyocyte contractile function and the interaction of AGEs with RAGE in the heart are altered in ageing, 25- and 2-month-old male rats were compared. Mechanical properties were assessed in ventricular myocytes using an edge-detection system, including peak twitch amplitude (PTA), time-to-PTA (TPS), time-to-75% relengthening (TR75) and maximal velocity of shortening/relengthening (+/-dL/dt) in ventricular myocytes. AGEs were detected by using a fluorescence assay. The expression of RAGE and NF-kappaB was assessed through a Western blot analysis. Compared with young myocytes, aged myocytes displayed a prolonged TR75 at 1 Hz. With increasing stimulus frequency (from 2 to 4 Hz), aged myocytes' PTA was significantly reduced relative to young myocytes. Aged rat hearts displayed high level of AGEs, RAGE upregulation and NF-kappaB activation. These findings demonstrate impaired cardiomyocyte relaxation and reduced tolerance to increased stimulus frequency in aged rats, which might be associated with enhanced AGEs, RAGE expression, and NF-kappaB activation.

Using direct nanoimprinting to study extraordinary transmission in textured metal films

In this paper, we describe a thermal embossing imprint method, which we name "nano-imprinting in metal" (NIM), for patterning metal films with a variety of profiles. Metal films exhibiting either perforated hole-arrays or corrugated structures with various surface morphologies can be fabricated rapidly. The SPR phenomenon allowed energy coupling to the other side of the textured metal film, causing a dramatic increase in the transmission. As a technique for readily controlling the working wavelength and transmittance, the NIM method has great potential for application in various optoelectronic devices.

High variation of PCDDs, PCDFs, and dioxin-like PCBs ratio in cooked food from the first total diet survey in Taiwan

This study determined the levels of polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDD/Fs), and dioxin-like polychlorinated biphenyls (dl-PCBs) in 240 individual food samples, belonging to 37 different foodstuffs in first total diet study (TDS) in Taiwan. The foods were collected from markets located in eight cities or counties around Taiwan. The food was cooked in a laboratory according to recipes typically used in Taiwan. In this study, PCDD/Fs were lower than the limits proposed by the European Union (EU) regulation for commercialized food, except for a notable PCDD/Fs level in ducks (3.660 pg WHO-TEQ/g, fat) obtained from central Taiwan. We hypothesize the duck meat might be probably polluted via emission of a fly ash recycling plant located near the duck farms. In addition to fish, most foods had high PCDD/Fs to dl-PCBs ratio. Needle fish and sea perch had relatively lower PCDD/Fs and dl-PCBs levels compared with those in other fish. Data from this study can be utilized for further consideration about dietary intake.

Production of ozone and reactive oxygen species after welding

Many toxic substances including heavy metals, ozone, carbon monoxide, carbon dioxide, and nitrogen oxides are generated during welding. Ozone (O(3)) is a strong oxidant that generates reactive oxygen species (ROS) in tissue, and ambient ROS exposure associated with particles has been determined to cause DNA damage. Ozone is produced within 30 seconds during welding. However, the length of time that O(3) remains in the air after welding is completed (post-welding) is unknown. The current study aimed to assess the distributions of ambient ROS and O(3) before the start of welding (pre-welding), during welding, and after welding. The highest O(3) levels, equal to 195 parts per billion (ppb), appeared during welding. Ozone levels gradually decreased to 60 ppb 10 minutes after the welding was completed. The highest ROS level was found in samples taken during welding, followed by samples taken after the welding was completed. The lowest ROS level was found in samples taken before the welding had started. Ozone and ROS levels were poorly correlated, but a similar trend was found for O(3) and ROS levels in particles (microM/mg). Although particles were not generated after welding, ROS and O(3) still persisted for more than 10 minutes. Meanwhile, because O(3) continues after welding, how long the occupational protective system should be used depends on the welding materials and the methods used. In addition, the relationship between metal fumes and ROS generation during the welding process should be further investigated.

Using colloidal lithography to fabricate and optimize sub-wavelength pyramidal and honeycomb structures in solar cells

The external quantum efficiency of solar cells can be improved by using texturing pyramid- and honeycomb-like structures with minimum reflection. In this study, we investigated the reflection properties of texturing structures through rigorous coupled-wave analysis and the three-dimensional finite-difference time domains (FDTD) method to analyze close-packed texturing structures. We also demonstrate a simple method-combining sub-wavelength-scale monolayer and bilayer polystyrene spheres with a one-step reactive ion etching process-to fabricate optimized pyramid- and honeycomb-shaped antireflection structures, respectively. Thus, sub-wavelength pyramidal and honeycomb-like structures displaying low reflectance were obtained readily without the need for any lithography equipment.

Generalized model for orbital angular momentum states generated by parallel aligned phase wedges

A generalized model of a double-wedge phase element containing two side-by-side parallel phase ramps with arbitrary slope angles is proposed. We study the diffracted optical field of a double-wedge element in terms of orbital angular momentum states. Analytical calculations reveal how the radius and position of the illuminating laser beam affect the composition of orbital angular momentum generated by the phase wedges.

The plasma membrane Na+/Ca2+ exchanger is cleaved by distinct protease families in neuronal cell death

Neurodegenerative conditions commonly involve loss of neuronal connectivity, synaptic dysfunction with excessive pruning, and ionic imbalances. These often serve as a prelude to cell death either through the activation of apoptotic or necrotic death routines or excess autophagy. In many instances, a local or generalized Ca2+ deregulation is involved in signaling or executing cell death. We have recently shown that in brain ischemia, and during excitotoxicity triggered by excess glutamate, the irreversible Ca2+ deregulation leading to necrosis is due to calpain-mediated modulation of the plasma membrane Na+/Ca2+ exchanger (NCX). Here we show that the NCX can also be cleaved by caspases in neurons undergoing apoptosis, which suggests that cleavage of the main Ca2+ extrusion pathway is a lethal event in multiple forms of cell death.

High average daily intake of PCDD/Fs and serum levels in residents living near a deserted factory producing pentachlorophenol (PCP) in Taiwan: influence of contaminated fish consumption

An abandoned pentachlorophenol plant and nearby area in southern Taiwan was heavily contaminated by dioxins, impurities formed in the PCP production process. The investigation showed that the average serum PCDD/Fs of residents living nearby area (62.5 pg WHO-TEQ/g lipid) was higher than those living in the non-polluted area (22.5 and 18.2 pg WHO-TEQ/g lipid) (P<0.05). In biota samples, average PCDD/F of milkfish in sea reservoir (28.3 pg WHO-TEQ/g) was higher than those in the nearby fish farm (0.15 pg WHO-TEQ/g), and Tilapia and shrimp showed the similar trend. The average daily PCDD/Fs intake of 38% participants was higher than 4 pg WHO-TEQ/kg/day suggested by the world health organization. Serum PCDD/F was positively associated with average daily intake (ADI) after adjustment for age, sex, BMI, and smoking status. In addition, a prospective cohort study is suggested to determine the long-term health effects on the people living near factory.

Pluronic F127 gel effectively controls the burst release of drug from PLGA microspheres

To investigate the controlled release effect of a thermo-sensitive gel, Pluronic F127 (PF127) on microspheres, poly[D,L-lactic-co-glycolic acid] (PLGA) microspheres were coated with Pluronic F127 gel and the in vitro release was evaluated. The results demonstrated that PF127, which gelled at 37 degrees C, inhibited the initial burst release of drug from microspheres effectively.

alpha-1,3-Fucosyltransferase-VII stimulates the growth of hepatocarcinoma cells via the cyclin-dependent kinase inhibitor p27Kip1

After the transfection of alpha-1,3-fucosyltransferase (FucT)-VII cDNA into H7721 human hepatocarcinoma cells, the protein expression of some cyclins, cyclin-dependent kinases (CDKs) and cyclin-dependent kinase inhibitors (CDIs) p16INK4 and p21waf1/Cip1 were unchanged. However, CDI p27Kip1 protein, both the total amount and the amount that bound to CDK2, but not its mRNA, was significantly reduced. The de-inhibited CDK2 stimulated the phosphorylation of retinoblastoma (Rb) protein and facilitated the G1/S transition and growth rate of the cells. The decrease of p27Kip1 protein, the increase of CDK2 activity and Rb phosphorylation, as well as the cell growth and percentage of S phase cells were correlated to the increased amount of cell surface sialyl Lewis X (SLe(x)) antigen in cells with different alpha-1,3-FucT-VII expression. The reduction in p27Kip1 and the difference in its expression among different transfected cells were blocked by the SLe(x) antibody KM93 in a dose-dependent manner, indicating that p27Kip1 expression was influenced by alpha-1,3-FucT-VII and its product SLe(x). The MEK/MAPK signaling pathway was more important than the PI-3K pathway in the regulation of p27Kip1 expression.

Overexpression of an Aurora-C kinase-deficient mutant disrupts the Aurora-B/INCENP complex and induces polyploidy

Aurora kinases are emerging as key regulators of centrosome function, chromosome segregation and cytokinesis. We previously isolated Aurora-C (Aie1), a third type of Aurora kinase, in a screen for kinases expressed in mouse sperm and eggs. Currently, we know very little about the precise localization and function of Aurora-C. Immunofluorescence analysis of ectopically expressed GFP-Aurora-C has revealed that Aurora-C is a new member of the chromosomal passenger proteins localizing first to the centromeres and then to the central spindles during cytokinesis. In order to study the potential role of Aurora-C, we examined the effects of a kinase-deficient (KD) mutant (AurC-KD) in HeLa Tet-Off cells under tetracycline control. Our results showed that overexpression of AurC-KD causes defects in cell division and induces polyploidy and apoptosis. Interestingly, AurC-KD overexpression also inhibits centromere/kinetochore localization of Aurora-B, Bub1, and BubR1, reduces histone H3 phosphorylation, and disrupts the association of INCENP with Aurora-B. Together, our results showed that Aurora-C is a chromosomal passenger protein, which may serve as a key regulator in cell division.

Comparision of interleukin-6 and malondialdehyde levels in diabetic patients in Taiwan

The purpose of this study was to compare the levels of interleukin-6 (IL-6) and malondialdehyde (MDA) in healthy controls and diabetic patients without coronary heart disease (CHD). Fasting serum IL-6 and MDA were determined in 30 healthy controls and 52 (20 Type 1 and 32 Type 2) diabetic patients without clinical evidence of CHD. MDA was calculated as oxidative stress. The IL-6 concentration was used to evaluate the cytokine function. Results showed that the serum IL-6 and MDA concentrations are significantly higher in Type 2 diabetic patients (p<0.05). In conclusion, we demonstrated that Type 2 diabetic patients are more influenced by oxidative stress than Type 1 diabetic patients and healthy controls, because of the action of cytokine.

Aging of poly(2-methoxy-5-(2'-ethylhexyloxy)-1,4-phenylenevinylene)/toluene solutions and subsequent effects on luminescence behavior of cast films

Morphological effects in luminescence properties of a representative semiconducting polymer, poly(2-methoxy-5-(2'-ethylhexyloxy)-1,4-phenylenevinylene) (MEH-PPV), has recently attracted much attention. Previous studies indicated that short-term heat treatment of solution-cast MEH-PPV films may result in the formation of mesomorphic order that is responsible for the "red" emission around 640 nm, in contrast to the single-chromophore "yellow" emission near 590 nm from the disordered matrix. On the basis of microscopic and spectroscopic evidence for films cast from freshly prepared and aged solutions, here we show that prolonged storage of MEHyellowPPV solutions at room temperature or lower may result in retardation of the thermally induced mesophase formation in the subsequently cast films. According to small-angle neutron scattering and differential scanning calorimetric observations over aged MEH-PPV/toluene solutions, we propose that the suppressed transformation into mesomorphic order is due to further development of nanocrystalline aggregates that serve as physical cross-links among MEH-PPV chains in the solution state upon long-term storage. These solvent-induced nanocrystalline aggregates, however, do not exhibit new spectroscopic features beyond the suppression of "red" emission at 640 nm from the mesomorphic phase.

N-acetylglucosaminyltransferase V modifies the signaling pathway of epidermal growth factor receptor

Transfection of sense cDNA of N-acetylglucosamyltransferase V (GnTV-S) into human H7721 hepatocarcinoma cells resulted in an increase in the N-acetylglucosaminebeta1,6mannosealpha1,3- branch (GnT-V product) on the N-glycans of epidermal growth factor (EGF) receptor (EGFR), and promotion of its EGF binding and tyrosine autophosphorylation, but showed little effect on the expression of EGFR protein. The phosphorylation at T308, S473 and tyrosine residue(s) and the activity of protein kinase B (Akt/PKB) as well as the phosphorylation of p42/44 mitogen-activated protein kinase (MAPK) and MAPK kinase (MEK) before and after EGF stimulation were concomitantly increased. Conversely, in the antisense GnT-V (GnTV-AS)-transfected H7721 cells, all the results were the reverse of those with GnTV-S-transfected cells. After the cells were treated with 1-deoxymannojirimycin, an inhibitor of N-glycan processing at high mannose, or antibody against the extracellular glycan domain of EGFR, the differences in PKB activity, p42/44 MAPK and MEK phosphorylation among GnTV-S-, GnTV-AS- and mock-transfected cells were significantly attenuated. These findings indicate that the altered expression of GnT-V will change the glycan structure and function of EGFR, which may modify downstream signal transduction.

Identification of a novel microtubule-destabilizing motif in CPAP that binds to tubulin heterodimers and inhibits microtubule assembly

We have previously identified a new centrosomal protein, centrosomal protein 4.1-associated protein (CPAP), which is associated with the gamma-tubulin complex. Here, we report that CPAP carries a novel microtubule-destabilizing motif that not only inhibits microtubule nucleation from the centrosome but also depolymerizes taxol-stabilized microtubules. Deletion mapping and functional analyses have defined a 112-residue CPAP that is necessary and sufficient for microtubule destabilization. This 112-residue CPAP directly recognizes the plus end of a microtubule and inhibits microtubule nucleation from the centrosome. Biochemical and functional analyses revealed that this 112-residue CPAP also binds to tubulin dimers, resulting in the destabilization of microtubules. Using the tetracycline-controlled system (tet-off), we observed that overexpression of this 112-residue CPAP inhibits cell proliferation and induces apoptosis after G2/M arrest. The possible mechanisms of how this 112-residue motif in CPAP that inhibits microtubule nucleation from the centrosome and disassembles preformed microtubules are discussed.

Serum PCDD/F concentration distribution in residents living in the vicinity of an incinerator and its association with predicted ambient dioxin exposure

The aim of this study was to evaluate the serum polychlorinated dibenzo-p-dioxin (PCDD) and dibenzofuran (PCDF) concentration distribution in residents living in the vicinity of an incinerator and its association with annual ambient dioxin exposure predicted by an atmospheric dispersion model. A municipal waste incinerator in Northern Taiwan was chosen for this study. This incinerator had been in operation for 6 years at the time of this study. Using the incinerator site as the center, based on the simulated ambient annual average PCDD/F concentrations. Ninety-five volunteers, all live within a radius of 5 km from the incinerator for at least 5 years, who had no occupational exposure potential, were selected based on the population distribution in each district. The average serum PCDD/F concentration for these subjects living within four zones was about 14 pg I-TEQ/g lipid. The serum distribution levels of people of the four study zones, however, were not consistent with the predicted ambient levels. Results also suggest that ambient exposure might not be the most important contributor to serum concentrations when compared to other exposure sources, such as dietary intake.

Evaluation of different methods to determine the loading of proteins in PLGA microspheres

Various determination methods for protein encapsulation efficiency of PLGA microspheres were compared. Acetonitrile is recommended as an extraction solvent.

Effect of Pluronic on cellular uptake of cationic liposomes- mediated antisense oligonucleotides

Cationic liposomes modified by different Pluronic block copolymers were prepared. The influence of Pluronic on the cellular uptake of antisense oligonucleotides (ODN) based on cationic 3beta[N-(N', N'-dimethylaminoethan)-carbamoyl] cholesterol (DC-Chol) liposomes was studied by flow cytometric analysis. It showed that DC-Chol liposomes containing Pluronic gave 1.7-2.3 times higher capacity of cellular uptake of ODN, despite the diminution of ODN loading efficiency. The level of improvement by Pluronic is related to the hydrophobic propylene oxide (PO) units Pluronic contains as well as the lipophile/hydrophile value of the molecule. This preliminary study indicated that modifying liposomes with another excipient is a useful pharmaceutical technique to improve ODN delivery.

[Second sampled survey on the distribution of human parasites in Zhejiang Province]

OBJECTIVE

Twenty-six species of human parasites were recorded in Zhejiang Province in 1987-1989 as a part of the national investigation on the distribution of human parasites, and the total prevalence was 80.2%. In order to find out possible changes on the composition of parasite species and decrease of prevalence after control intervention particularly mass chemotherapy in the past years and provide evidence for an improved control strategy, the second sampled survey was carried out from 1998 to 1999.

METHODS

Ten counties were identified randomly out of 28 counties where the last survey was conducted following the same sampling method. Same technics were used for case detection and data processing.

RESULTS

The total infection rate in a sample of 15,698 was 22.84% was 22.84% in 30 investigation spots in 10 counties, and 17 species of parasites were revealed. The overall prevalence was reduced by 71.51% in comparison to that of 1989, and the number of parasite species was 17, 9 less than that of the last investigation.

CONCLUSIONS

The prevalence of human parasites has greatly declined in this province due to the socioeconomic development and adoption of comprehensive control measures focusing on mass chemotherapy in the past decade.

Expressions of Lewis antigens in human non-small cell pulmonary cancer and primary liver cancer with different pathological conditions

The expressions of three X series Lewis antigens, including Lewis X (Le(x)), sialyl Lewis X (SLe(x)) and sialyl dimeric Lewis X (SDLe(x)) were studied with immuno-histochemical methods in human non-small cell pulmonary cancer (NSCPC) and primary liver cancer (PLC) with different pathological conditions. The Lewis antigens are mainly expressed on the cell surfaces, medially or slightly in the cytoplasm, but not in the cell nuclei of the cancer tissues. The regions adjacent to the cancer tissues do not express any Lewis antigens. The positive rates of these antigens in NSCPC were within the range of 75% to approximately 86%. There was no apparent difference in positive rates between the cases with different differentiation and the presence or absence of metastasis in peripheral lymph nodes, nor among the three antigens, except that the positive rate of SDLe(x) was lower (about 56%) in the cases with well/medium differentiation and without metastasis. However, the expression-intensities (SI indexes) of all three antigens were significantly higher in the samples of poor differentiation and with metastasis as compared to those with well/medium differentiation and without metastasis. The two sialyl Lewis antigens increased more significantly than non-sialylated Le(x). The expressions of these antigens were also observed in the peripheral lymph nodes with metastasis, but not in those without metastasis. The positive rates of Le(x), SLe(x) and SDLe(x) in human primary liver cancer were 83.3%, 88.9% and 77.8%, respectively. In the cases with cancer cell thrombosis (CCT) in portal vein (an index of metastasis), the expressions of all these three antigens were stronger than those in the cases without CCT. SLe(x) was the most abundant and most highly increased Lewis antigen on the surface of NSCPC and PLC, especially in the cases with poor differentiation and metastasis. In the study of the enzymatic basis of the increased Lewis antigens in PLC by using Northern blot, it was found that the level of alpha1,3 FucT-III/VI mRNA in PLC tissues was much higher than that in the adjacent regions, and more significantly higher in the cancer tissues from patients with CCT in portal vein. In contrast, the expression of alpha1,3 FucT-VII was rather low in cancer tissues and not different from the adjacent regions in spite of the presence or absence of CCT. These results reveal that the SLe(x) in PLC is mainly synthesized by alpha1,3 FucT-III/VI (especially VI) and is the most important Lewis antigen involved in the metastasis of PLC.

Effects of lentinan on broiler splenocyte proliferation, interleukin-2 production, and signal transduction

Lentinan (LEN) is an intensively studied beta-glucan that has been shown to have immunostimulating and antitumor functions. However, it currently is not used in veterinary practice and animal production. This study was conducted to investigate the impacts of LEN on broiler splenocyte proliferation, interleukin-2 (IL-2) production, and to explore its effects on receptor signal transduction by determining signaling molecules, including nitric oxide (NO), cytosolic-free Ca2+, cytosolic cyclic adenosine monophosphate (cAMP), and cyclic guanosine monophosphate (cGMP). The results showed that compared to the control all three measured doses, including 40, 80, and 160 microg/mL LEN, increased splenocyte proliferation and IL-2 production (P < 0.05). Lentinan increased splenocyte NO production and cytosolic-free calcium concentration in a dose-dependent manner (P < 0.001). After incubating splenocytes for 20 min, LEN increased intracellular cAMP and cGMP concentrations at a dose of 80 and 160 microg/mL, respectively. However, after incubating the splenocytes for 60 min, LEN had no effect on cytosolic cAMP and cGMP concentration irrespective of the LEN dosage. Those results indicated that LEN had immunostimulatory effects on splenocytes by increasing splenocyte proliferation and IL-2 production and by activating splenocyte receptor signal transduction.

Effect of circumferential undercut placement in the root canal wall on the retention of a tapered post in large and small root canals

OBJECTIVES

This study examined the influence of root canal space and circumferential undercut placement in the dentine wall on the retention of a prefabricated Root Keeper post.

METHODS

Twenty-four extracted single-rooted teeth, having narrow root canal spaces, were decoronated, treated endodontically, and then centrally embedded in resin blocks. All canal spaces were prepared with a no. 2 Peeso reamer to an 8mm depth, and half the specimens were successively treated with a no. 3 Peeso to depths of 5 and 8mm for the small canal group (SC) and large canal group (LC), respectively. An L-type keeper post (Aichi Steel Co.) was luted to each canal with resin cement. The assembly was thermocycled 2000 times (4-60 degrees C), and post retention was measured. Afterwards the dislodged post with the intact structure was sandblasted, and the canal was cleaned and slightly undercut using an inverted cone bur. Six treated posts were recemented for both grooved large canal (GLC) and grooved small canal (GSC) groups, and the repaired retentive strengths were measured.

RESULTS

Keeper posts cemented in SC (84.26+/-31.85N) showed better (p<0.05) retention than those cemented in LC (41.92+/-22.36N). Interestingly, the repaired strengths of the recemented post increased in both GSC (104.29+/-11.89N) and GLC (96.65+/-6.91N). All posts, except for one in the GLC, failed at the keeper-post joint.

CONCLUSIONS

Prefabricated Root Keeper posts had lower retentive strength in roots with a large canal space. Placement of a circumferential undercut in the root canal wall significantly enhanced the retention of the short tapered posts.

Effects of Chinese herbal polysaccharides on the immunity and growth performance of young broilers

Two trials were conducted to study the effects of two Chinese herbal polysaccharides [achyranthan (ACH), a low-molecular-weight polysaccharide, and astragalan (APS), a high-molecular-weight polysaccaride] on the immunity and growth performance of young broilers. Trial 1 was a 28-d growth assay, in which 7-d-old broilers (n = 240) were randomly allotted to one of three dietary treatments, with eight replicate pens per treatment and ten chickens per pen. Dietary treatments included a control corn-soy-fishmeal (Treatment 1), a diet with 200 mg/kg APS (Treatment 2), and a diet with 200 mg/kg ACH (Treatment 3). Blood samples were collected by cardiac puncture on Days 7, 14, 21, and 28 for determination of serum parameters, and chickens were killed on Day 28 to measure immune organ indexes. Trial 2 was an in vitro trial to study the effects of different concentrations of polysaccharides on broiler splenocyte functions. In Trial 1, feeding either APS or ACH had no significant effects on growth performance of broilers relative to the control. However, compared to the control, feeding ACH significantly increased microhemagglutination inhibition (HI) antibody titers, bursa of Fabricius index, serum albumin, serum calcium, and nitric oxide (NO) concentrations at Day 28 (P < or = 0.05). In Trial 2, both polysaccharides showed significant immunostimulating effects. They increased NO and interleukin-2 (IL-2) production of splenocytes and enhanced splenocyte proliferation in a dose-dependent manner (P < 0.05). Those results indicate that the immunostimulating effects of APS are not as pronounced as those of ACH. Achyranthan showed immunostimulating effects in both the growth assay and in vitro studies. Therefore, ACH may be a Chinese herbal polysaccharide that has the potential to be used as a feed additive to improve broilers' immunity.

Analysis of lewis antigens on cell surface and alpha1,3 fucosyltransferase subtypes in H7721 human hepatocarcinoma cells

The expressions of Lewis antigens on H7721 human hepatocarcinoma cells were detected with monoclonal antibodies and flow-cytometry. It was found that H7721 mainly expressed SLex, and a small amount of SDLex, but Lex and SLea was negligible. The monoclonal antibody of SLex (KM93) significantly blocked the adhesion of H7721 cells to human umbilical vein epithelial cells, as well as cell migration and invasion, but the blocking effect of SDLex antibody (FH6) was not statistically significant. The expressions of five subtypes of alpha1,3fucosyltransferases (alpha1,3FucTs), the enzyme responsible for the fucosylation step in Lewis antigen synthesis, were also studied using real-time RT-PCR. The expression of FucT mRNAs were FucT-IV > FucT-III > FucT-VI > or = FucT-VII > FucT-IX. FucT-VI is supposed to be the main enzyme responsible for the synthesis SLex and SDLex. FucT-VII and III may also participate in SLex synthesis. The absence of FucT-IX expression and FucT-III not being the rate-limiting enzyme for SLea synthesis may be the reasons for the negligible expressions of Lex and SLea on the cell surface, respectively.

Bone morphogenetic proteins are involved in fetal kidney tissue transplantation-induced neuroprotection in stroke rats

Both bone morphogenetic proteins (BMPs) and glial cell line-derived neurotrophic factor (GDNF) reduce ischemia-induced cerebral injury in rats. Intracerebral transplantation of fetal kidney tissue, which normally expresses BMPs and GDNF during development, reduces ischemic injury in cerebral cortex. In this study, we tested the hypothesis that BMP is involved in this neuroprotective response. Fetal kidney tissue was cut into small pieces and transplanted into cortical areas adjacent to the right middle cerebral artery (MCA) in adult rats. In situ hybridization of brain indicated that these fetal kidney transplants contained high levels of BMP-7 mRNA three days after grafting. Immunohistochemical analysis of grafted brain showed co-localization of BMP-7 and PAX-2 immunoreactivity in the graft, suggesting that these transplants contained BMP protein. Some animals were grafted with fetal kidney tissue after intraventricular administration (ICV) of the BMP antagonist noggin (1 micro g) or after vehicle, followed by MCA ligation for 60 min. Animals receiving fetal kidney tissue transplantation developed significantly less body asymmetry, as compared to stroke animals that either did not receive transplantation or received fetal kidney grafts and noggin pretreatment. Analysis of these brains after triphenyltetrazolium chloride staining showed that fetal kidney tissue transplantation reduced the volume of infarction in the cerebral cortex. Noggin pretreatment reduced the protection induced by fetal kidney grafting, although noggin itself did not cause increase in cerebral infarction. Eight hours after ischemia, brain homogenates were obtained from grafted and control animals to assay caspase-3 enzymatic activity. This analysis demonstrated that fetal kidney grafts significantly reduced ischemia-induced caspase-3 activity. Reduction of caspase-3 activity could also be antagonized by noggin pretreatment. In conclusion, our data suggest that fetal kidney transplantation reduces ischemia/reperfusion-induced cortical infarction and behavioral deficits in adult rats, which are, at least partially, mediated through the effect of BMPs from the transplants.

Hepatitis B virus infection in children and adolescents in a hyperendemic area: 15 years after mass hepatitis B vaccination

BACKGROUND

Hepatitis B virus (HBV) infection is hyperendemic in Taiwan. Before universal HBV immunization was started in Taiwan in 1984, the carrier rate for hepatitis B surface antigen (HBsAg) was 15% to 20% in the general population.

OBJECTIVE

To quantify the population impact of a mass vaccination program for HBV 15 years after its implementation.

DESIGN

Descriptive analysis of serologic markers of HBV in healthy children and adolescents.

SETTING

Chung-Cheng District, Taipei City, Taiwan, in 1999.

PARTICIPANTS

1357 persons younger than 15 years of age, who were born after the implementation of universal HBV vaccination, and 559 persons 15 to 20 years of age, who were born before the program began.

MEASUREMENTS

Repeated serologic surveys similar to those done before and 5 and 10 years after the national vaccination program was implemented. All participants were tested for serum HBsAg, its antibody (anti-HBs), and hepatitis B core antibody (anti-HBc).

RESULTS

During the 15 years since the vaccination program was implemented, the prevalence of HBsAg among persons younger than 15 years of age decreased from 9.8% in 1984 to 0.7% in 1999; among persons 15 to 20 years of age, the 1999 prevalence of HBsAg was 7% (P < 0.001). Hepatitis B core antibody seropositivity, which represents HBV infection, was found in 2.9% of persons younger than 15 years of age and in 20.6% of persons 15 to 20 years of age (P < 0.001); in the same age groups, the rate of anti-HBs seropositivity was 75.8% and 70.7%, respectively (P = 0.02).

CONCLUSIONS

Universal vaccination significantly decreased the HBV carrier rate and infection rate among children and adolescents born since the program began. By decreasing the carrier pool, continuation of the national HBV immunization program should prevent HBV infection in the children of Taiwan, and, subsequently, adults as well.

[Determination of impurity elements in alloy aluminum by ICP-AES]

A method for the determination of Cr, Zn, Fe, Mn, Ti, Cu and Mg impurity elements of alloy aluminum of ICP-AES was studied. Working conditions were optimized. The method is simple, rapid, precise and convenient. The relative standard deviation is less than 6.3%. The recovery is 94%-105%. The results are satisfactory.

Congenital generalized lipodystrophy in a 4-month-old infant

Congenital generalized lipodystrophy (CGL, Berardinelli-Seip syndrome) is a rare autosomal recessive disorder with a clinical presentation of paucity of adipose tissue, muscular hypertrophy, organomegaly, and insulin-resistant diabetes. A 4-month-old Taiwanese female infant had hepatosplenomegaly and low body weight gain despite a voracious appetite. Hypermetabolism, hyperhidrosis, loss of subcutaneous fat, muscular hypertrophy, acanthosis nigricans, hypertrichosis, and marked hypertriglyceridemia were also noted. Liver histology revealed fatty change and portal-to-portal bridging fibrosis. Clinical features, serum biochemistry, and liver histology were compatible with the diagnosis of CGL. She was given a special diet characterized by calorie restriction and partial substitution of long-chain triglycerides with medium-chain triglycerides. The serum triglyceride concentration subsequently decreased. This present case suggests that extensive fatty infiltration and subsequent cirrhosis of the liver may be the earliest complication of CGL.

Bone morphogenetic protein-6 reduces ischemia-induced brain damage in rats

BACKGROUND AND PURPOSE

Bone morphogenetic protein-6 (BMP6) and its receptors are expressed in adult and fetal brain. Receptors for BMP6 are upregulated in adult brain after injury, leading to the suggestion that BMP6 is involved in the physiological response to neuronal injury. The purpose of this study was to determine whether there was a neuroprotective effect of BMP6 in vivo and in vitro.

METHODS

Lactate dehydrogenase and microtubule-associated protein-2 (MAP-2) activities were used to determine the protective effect of BMP6 against H(2)O(2) in primary cortical cultures. The neuroprotective effects of BMP6 were also studied in chloral hydrate-anesthetized rats. BMP6 or vehicle was injected into right cerebral cortex before transient right middle cerebral artery (MCA) ligation. Animals were killed for triphenyl-tetrazolium chloride staining, caspase-3 immunoreactivity and enzymatic assays, and TUNEL assay. A subgroup of animals were used for locomotor behavioral assays.

RESULTS

Application of H(2)O(2) increased lactate dehydrogenase activity and decreased the density of MAP-2(+) neurons in culture. Both responses were attenuated by BMP6 pretreatment. Complementary in vivo studies showed that pretreatment with BMP6 increased motor performance and generated less cerebral infarction induced by MCA ligation/reperfusion in rats. Pretreatment with BMP6 did not alter cerebral blood flow or physiological parameters. There was decreased ischemia-induced caspase-3 immunoreactivity, caspase-3 enzymatic activity, and density of TUNEL-positive cells in ischemic cortex in BMP6-treated animals.

CONCLUSIONS

BMP6 reduces ischemia/reperfusion injury, perhaps by attenuating molecular events underlying apoptosis.

[GnT-V overexpression in human hepatocarcinoma cells affects its migration and expression of cell adhesion molecules]

The purpose of this paper is to study the effect of N-acetylglucosaminyltransferase V (GnT-V) overexpression on the migration of 7721 cells and its mechanism. The abilities of migration of both 7721 cells transfected with GnT-V cDNA and 7721 cells transfected with pcDNA3 was detected, the expressions of integrin and E-cadherin which are important adhesion molecules on surface membrane and closely related to the abilities of invasion and metastasis. Cell migration abilities were measured by the agarose drop explant method. Flow cytometric analysis (FACS) was applied to determine the relative amounts of integrin alpha 5 and beta 1 subunits on the cell surface while RTPCR was carried out to determine the expression of their mRNA. The expression of E-cadherin was examined by the immunocytochemical ABC method. Western blot analysis was carried out to examine the expression of beta-catenin. GnT-V overexpression enhanced evidently the migration ability of 7721 cells and increased the amount of integrin alpha 5 subunit to 2.9 times of that of control while the amount of beta 1 subunits was not significantly changed. Besides, the expressions of E-cadherin and beta-catenin were enhanced at different levels in GnT-V/7721 cells compared with mocked. The results suggested that the overexpression of GnT-V related to the production of N-linked sugar chains could promote the expressions of integrin, E-cadherin and beta-catenin on 7721 cells so that the migration ability of tumor cells was enhanced.

Structural alterations of sugar chains in urine fibronectin from bladder cancer patients and its enzymatic mechanism

PURPOSE

To study the structural alterations of asparagine-linked sugar chains (N-glycans) on urine fibronectin (Fn) from bladder cancer (BCa) patients and its enzymatic mechanism.

METHODS

Eight pairs of urine samples from eight BCa patients pre-operation and 3 months post-operation (which proved to be normal) were collected, and the Fn in the urine samples was purified with an anti-Fn antibody affinity column. Different lectins labeled with horseradish peroxidase (HRP) were used as probes to bind the glycans of purified Fn immobilized on membrane. Enhanced chemiluminescence (ECL) reagent was adopted to estimate the activity of the bound HRP as a measure of the binding affinity of the Fn glycans to lectins, and expressed as luminescent light units (LLU). The enzymatic mechanism of the structural alteration of N-glycans in BCa Fn was studied by determination of GnT activities using the HPLC method and fluorescent-labeled substrate.

RESULTS

The mean LLU of BCa Fn was only 18.1% of the normal samples when Con A-HRP were used as probes, while the mean LLU of the BCa group was 3.34 times and 3.26 times higher than normal for the DSA-HRP and WGA-HRP probes, respectively. The individual data of the patients did not overlap between the BCa sample and normal counterparts, indicating that the positive rates were 100%, regardless of which lectin-HRP was used. These results reveal that the antennary number and bisecting GlcNAc structure are increased in the N-glycans of urine Fn from BCa assessed according to the binding specificity of ConA, DSA, and WGA. In addition, the binding affinities of urine Fn with DSA and WGA were correlated to pathological stage, and the affinity of Fn with WGA was also correlated with pathological grade. The results of GnT determination showed that GnT-III, IV, and V in BCa tissues increased by 34.0, 18.1, and 1.6 times, respectively, in normal bladder tissues which were at least 5 cm away from the BCa of the same bladder. These findings were compatible with the structural changes of N-glycans in BCa Fn, since GnT-III and GnT-IV/V are responsible for the synthesis of bisecting GlcNAc and the increase of antennary number in N-glycans, respectively.

CONCLUSIONS

(1) The highest elevation of GnT-III and the close relationship between the WGA binding of BCa Fn with the pathological stage and grade of BCa indicate that the increase of bisecting GlcNAc in N-linked glycans contributes more to the malignant behavior of BCa than the increase of GnT-IV, GnT-V, and the antennary number. (2) The correlation of altered activities of bladder GnTs with the abnormal structures of urine Fn in BCa patients indicates that the urine Fn is synthesized in the bladder. (3) The lectin-HRP assay for analyzing the structure of N-glycans in urine Fn may be used as a simple and accurate diagnosis method for BCa in the future.

Pathotypes of Pyricularia grisea in Rice Fields of Central and Southern China

Blast, caused by the fungal pathogen Pyricularia grisea, is the most devastating disease of rice worldwide. Knowledge of the pathotype composition of the pathogen in rice fields is essential for rational deployment of resistance genes in rice breeding programs. In this study, we assayed the pathotypes of the pathogen populations using samples recently collected from 13 major rice-growing provinces of central and southern China. In all, 792 single spore isolates were tested for pathogenicity reactions using 13 host differentials consisting of six indica and seven japonica near-isogenic lines (NILs). The compositions of the pathogen populations were complex; 48 pathotypes were identified with the indica NILs, 82 pathotypes were detected with the japonica NILs, and a total of 344 pathotypes were identified with both indica and japonica NILs. There were large differences in distribution of the pathotypes among the different rice-growing areas. Even neighbor provinces seemed to differ sharply in types and frequencies of the most prevalent pathotypes. There was also a large difference in the frequencies of the isolates producing compatible reactions on the NILs, indicating the difference in frequencies of avirulence genes in the pathogen populations. The data provided very useful information for formulating strategies for improving blast resistance in rice breeding programs.

Bacterial cholangitis in patients with biliary atresia: impact on short-term outcome

Bacterial cholangitis (BC) is a common complication in patients with biliary atresia (BA) and is characterized by fever, acholic stools and positive blood cultures. The diagnosis is often empirical because the yield of blood cultures is low. It is difficult to differentiate BC from other febrile episodes. In order to characterize the clinical and laboratory features of BC in patients with BA, identify risk factors, and correlate cholangitis with outcome, 37 patients with BA from 1993 to 1998 who underwent a Kasai operation in our hospital were studied. The follow-up period ranged from 6 to 59 months. A total of 107 febrile episodes were documented in these patients. The diagnostic criteria for cholangitis were fever, increased jaundice, or acholic stools. The clinical features, laboratory data, results of bacterial cultures, and outcomes were analyzed retrospectively. A total of 107 febrile episodes, including 78 bouts of cholangitis and 29 non-cholangitis infections, were found in 34 patients. Patients with BC had higher postoperative bilirubin levels (P = 0.02) and less frequent use of prophylactic antibiotics (P = 0.05) than those with non-cholangitis infections. Abnormal white blood cell counts (> 12,000 or <4,000 mm3) tended to be present in patients with BC (P = 0.08). There were no statistical differences in the risk factors and laboratory data between culture-positive (n = 16) and -negative (n = 62) cholangitis cases. The occurrence of cholangitis significantly reduced survival in both patients with good (P = 0.03) and inadequate bile flow (P = 0.03). All 9 patients who had never had cholangitis survived during the follow-up period. Repeated attacks of BC further decreased survival probability. The responsive organisms were mainly enteric bacteria, including Escherichia coli, Enterobacter cloacae, Klebsiella pneumoniae, Pseudomonas aeruginosa, Acinetobacter baumanni, and Salmonella typhi. The sensitivity tests justified empirical therapy with ceftriaxone. The effectiveness of prophylactic trimethoprim-sulfamethoxazole or neomycin warrants further studies. BC was a highly prevalent postoperative complication in patients with BA, especially those with inadequate bile drainage. It significantly affected early mortality. Aggressive and complete treatment with empirical ceftriaxone was appropriate.