Great and rapid HBsAg decline in patients with on-treatment hepatitis flare in early phase of potent antiviral therapy.

HBsAg decline during nucleos(t)ide analogue therapy in chronic hepatitis B with lower pretherapy ALT is usually small and slow. This study aimed to investigate why ~10% of such patients showed "rapid HBsAg decline" ≥0.5 log10 IU/mL by month 6 of therapy. Patients with persistent pretherapy ALT <5X ULN who had qHBsAg at baseline, months 6 and 12 of entecavir or tenofovir therapy were studied. "On-treatment ALT elevation" was defined as >10% increase above baseline to >2X ULN during first 6 months of therapy. Of the 256 patients treated, 51 experienced transient "on-treatment ALT elevation" [group A], including 30 (11.7%) with ALT elevation to 2-5X ULN [group A-1] and 21 (8.2%) flared to >5X ULN [group A-2]. The magnitude of qHBsAg decline and rate of "rapid HBsAg decline" by month 6 was significantly greater and more frequent in group A (-0.446 vs -0.042 log10 IU/mL; 45.1 vs 8.8%, respectively, P = 0.000) than in the remaining 205 patients without on-treatment ALT elevation (group B), being greatest in patients with hepatitis flare (group A-2: -0.559 log10 IU/mL and 57.1%, respectively). In patients with therapy ≥2 years, patients with "on-treatment ALT elevation" also showed significantly greater annual HBsAg decline, more frequent to <100 IU/mL and 4 times higher HBsAg seroclearance rate. "On-treatment ALT elevation," especially flare >5X ULN, during entecavir therapy or tenofovir therapy may enhance/accelerate HBsAg decline, suggesting the effect of immune restoration upon potent viral suppression.

Eradication of hepatitis C virus profoundly prolongs survival in hepatocellular carcinoma patients receiving transarterial chemoembolization.

Adjuvant pegylated interferon plus ribavirin treatment (PegIFN/RBV) reduces recurrence and prolongs survival in early stage hepatocellular carcinoma (HCC) patients with chronic hepatitis C (CHC) infection receiving resection or ablation. However, the impact of antiviral therapy in intermediate and advanced stage of CHC-HCC patients is uncertain. This study aimed to investigate the impact PegIFN/RBV treatment on recurrence-free interval and survival in patients with HCC receiving transarterial chemoembolization (TACE). From 2010 to 2013, 274 CHC patients from a 1073 patient-based cohort composed of freshly diagnosed HCC and receiving TACE treatment the Chang Gung Memorial Hospital, Linkou Medical Center were recruited. Propensity score matching (PSM) (age, gender, AST to Platelet Ratio Index (APRI), tumour size, tumour number and Child-Turcotte-Pugh score) with the ratio 1:2 for patients with and without PegIFN/RBV treatment was performed. Statistics were performed with SPSS V.20 (IBM, USA). After matching, 153 patients were analysed and 27 patients (17.6%) achieved sustained virologic response (SVR). The 2-year cumulative overall survival rate and recurrence-free survival rate among patients with SVR, non-SVR, and untreated were 85.2% vs 58.3% vs 69.6% (P=.001) and 73.3% vs 53.8% vs 58.5% (P=.013). By Cox regression analysis, non-SVR, untreated, increase CTP score and nonresponder to TACE were independent factors related to mortality. The SVR achieved by PegIFN/RBV treatment markedly improves survival and reduces tumour recurrence in CHC-HCC patients receiving TACE treatment after complete response.

Clinical outcomes after spontaneous and nucleos(t)ide analogue-treated HBsAg seroclearance in chronic HBV infection.

BACKGROUND: Both spontaneous and nucleos(t)ide analogue (Nuc)-treated hepatitis B surface antigen (HBsAg) seroclearance are associated with excellent clinical outcomes. AIM: To conduct a case-control study to explore whether there is difference of clinical outcomes between these two groups. METHODS: A total of 312 chronic hepatitis B patients with spontaneous HBsAg seroclearance and 110 patients with Nuc-treated HBsAg seroclearance were recruited retrospectively. Propensity score (PS) matching method produced 98 patients in each group for comparison. The development of hepatocellular carcinoma (HCC), hepatic complications and cumulative incidence of antibody to HBsAg (anti-HBs) was compared. RESULTS: During a mean follow-up period of 107 months after HBsAg seroclearance, five patients developed HCC after a mean period of 75.3 months (four and one patients with spontaneous and Nuc-treated HBsAg seroclearance, respectively) in overall population. One died of pneumonia with sepsis and one experienced variceal bleeding in Nuc-treated patients but none in spontaneous group. The incidence of anti-HBs seroconversion was comparable between spontaneous and Nuc-treated HBsAg seroclearance (69.6% vs. 66.4%, respectively, P = 0.617). There were no significant differences in HCC development (2% vs. 1.1%), overall mortality (0% vs. 1%), variceal bleeding (0% vs. 4.2%) and 6-year cumulative incidence of anti-HBs seroconversion (62.3% vs. 61.5%) among PS-matched patients with spontaneous and Nuc-treated HBsAg seroclearance. CONCLUSIONS: The clinical outcomes between patients with spontaneous and Nuc-treated HBsAg seroclearance are comparable. HCC can develop at a low rate during long-term follow-up and periodic surveillance after HBsAg seroclearance is still mandatory.

Clinical outcomes after interruption of entecavir therapy in HBeAg-negative chronic hepatitis B patients with compensated cirrhosis.

BACKGROUND: Long-term nucleos(t)ide analogues therapy may reduce hepatocellular carcinoma (HCC) in chronic hepatitis B patients with advanced fibrosis or cirrhosis. AIM: To investigate in a retrospective-prospective study whether this beneficial effect would be reduced in cirrhotic patients who discontinued a successful course of entecavir (ETV) therapy. METHODS: The study included 586 hepatitis B e antigen (HBeAg)-negative patients with compensated cirrhosis, mean age of 53.8 ± 10 years and 81% males, treated with ETV for at least 12 months. After ETV therapy for 46.5 ± 22.9 months, 205 patients who achieved hepatitis B virus (HBV) DNA suppression discontinued therapy. The clinical outcomes were assessed and HCC incidence was compared between propensity score (PS)-matched patients who continued and patients who discontinued ETV therapy by Asian Pacific Association for the Study of Liver stopping rule. RESULTS: During a mean duration of 59.3 ± 19 months after start of ETV therapy, nine and six HCC developed in an estimated annual incidence of 2.3% and 1.6% in 154 PS-matched patients who continued and who discontinued ETV therapy, respectively (P = 0.587). Multivariate Cox proportional hazards regression analyses showed that age (HR 1.065, P < 0.001) and HBV DNA (HR 1.216, P = 0.048) were the significant factors for HCC development. The rates of adverse clinical outcomes were comparable. CONCLUSIONS: The clinical outcomes, including HCC, after cessation of a successful course of entecavir therapy in patients with compensated cirrhosis were comparable to those who continued therapy. The results suggest that this strategy of finite therapy is safe and a feasible alternative to indefinite therapy, especially in a low resources setting.

Basal core promoter mutation is associated with progression to cirrhosis rather than hepatocellular carcinoma in chronic hepatitis B virus infection.

BACKGROUND: As most cases of hepatitis B virus (HBV)-related hepatocellular carcinoma (HCC) have concurrent cirrhosis, viral factors identified to be associated with HCC might be related to cirrhosis rather than HCC. METHODS: Hepatitis B virus DNA levels, genotypes and precore/basal core promoter (BCP) mutants were compared between cirrhotic HCC and non-cirrhotic HCC patients. Age- and sex-matched case-control studies were performed to identify the risk factors. RESULTS: Hepatitis B virus DNA levels showed no significant difference between non-cirrhotic HCC patients (n=20) and cirrhotic HCC patients (n=140) or 1 : 3 age- and sex-matched cirrhotic HCC patients (n=60), but genotype C and BCP mutant were significantly more prevalent in the latter than in the former. In multiple logistic regression, BCP mutant but not genotype C correlated significantly with the presence of cirrhosis in HCC patients. Compared with inactive carriers (n=60), non-cirrhotic HCC patients (n=20) had significantly higher HBV DNA levels but no difference in HBV genotypes and precore/BCP mutants. Furthermore, HBV DNA levels, the distribution of HBV genotypes and the prevalence of precore/BCP mutants all failed to show any significant difference between cirrhotic HCC patients (n=60) and cirrhotic patients without HCC (n=60). CONCLUSION: Basal core promoter mutant is associated with progression to cirrhosis rather than HCC in chronic HBV infection.

Prognostic factors in pathological stage IB nonsmall cell lung cancer greater than 3 cm.

Significant heterogenity of stage IB (sixth edition of the TNM staging system) nonsmall cell lung cancer (NSCLC) has been identified, and further subclassification according to tumour size has been proposed. The aim of this study is to evaluate the prognostic factors in patients with resected stage IB NSCLC > 3 cm. From January 1980 to December 2000, 525 patients underwent surgical resection for stage IB NSCLC > 3 cm at Taipei Veterans General Hospital, Taipei, Taiwan. The clinicopathological characteristics of these patients were retrospectively reviewed. The 5- and 10-yr overall survival rates were 44.9% and 27.3%, respectively. Age (p < 0.001), tumour size (p = 0.002), extent of pulmonary resection (p = 0.002), histological type (p = 0.005) and number of mediastinal lymph nodes dissected/sampled (p = 0.004) were significant predictors for overall survival in multivariate analysis. Patients with tumour size >7 cm, or > 5 to ≤ 7 cm, had a worse survival than those with tumour size > 3 to ≤ 5 cm. However, visceral pleural invasion did not influence overall survival. Stage IB NSCLC with a diameter > 3 cm may be subclassified according to tumour size regardless of visceral pleural invasion.

The catalase activity of Nalpha-acetyl-microperoxidase-8.

Nalpha-Acetylated microperoxidase-8 (Ac-MP-8) is a water soluble, ferric heme model for peroxidases. We report here that Ac-MP-8 catalyzes catalase-type reaction in addition to peroxidase-type and cytochrome P450-type reactions. The catalase activity of Ac-MP-8 was determined by the Clark oxygen electrode, which measures the production of oxygen in solution. The Km and kcat of the decomposition of hydrogen peroxide (H2O2) catalyzed by Ac-MP-8 are 40.9 mm and 4.1 per s, respectively. The specificity constant (kcat/Km) of Ac-MP-8 in catalase-type reaction of H2O2 is 100.2,/m/s, which is 5- to 12- and 50- to 100-fold less than those of MPs in cytochrome P450-type reaction of aniline/H2O2 and peroxidase-type reaction of o-methoxyphenol/H2O2, respectively. These results indicate that Ac-MP-8 can catalyze three different types of reactions, and the relative catalytic specificities of Ac-MP-8 with a histidyl ligand exhibit the following orders: peroxidase-type > cytochrome P450-type > catalase-type reactions. Comparisons of the enzyme activities of Ac-MP-8 suggest that the fifth ligands of hemoproteins influence the ratio of the three types of reactions.

Antibiotic activity of lectins from marine algae against marine vibrios.

Saline and aqueous ethanol extracts of marine algae and the lectins from two red algal species were assayed for their antibiotic activity against marine vibrios. Experimental studies were also carried out on the influence of environmental factors on such activity, using batch cultures. The results indicated that many of the saline extracts of the algal species were active and that the activity was selective against those vibrios assayed. The algal extracts were active against Vibrio pelagius and the fish pathogen V. vulnificus, but inactive against V. neresis. Algal lectins from Eucheuma serra (ESA) and Galaxaura marginata (GMA) strongly inhibited V. vulnificus but were inactive against the other two vibrios. The antibacterial activity of algal extracts was inhibited by pretreatment with various sugars and glycoprotein. Extracts of the two red algae, E. serra and Pterocladia capillacea, in saline and aqueous ethanol, inhibited markedly the growth rate of V. vulnificus at very low concentrations. Culture results indicated that metabolites active against V. vulnificus were invariably produced in P. capillacea over a wide range of temperature, light intensity, and nutritional conditions. Enhanced antibacterial activity occurred when P. capillacea was grown under higher irradiance, severe nutrient stress and moderate temperature (20 degrees C), reflecting the specific antibiotic characteristics of this alga. The strong antibiotic activity of lectins towards fish pathogenic bacteria reveals one of the important roles played by algal lectins, as well as the potential high economic value of those marine algae assayed for aquaculture and for biomedical purposes.

Biological activities of glucagon-like peptide-1 analogues in vitro and in vivo.

Studies support a role for glucagon-like peptide 1 (GLP-1) as a potential treatment for diabetes. However, since GLP-1 is rapidly degraded in the circulation by cleavage at Ala(2), its clinical application is limited. Hence, understanding the structure-activity of GLP-1 may lead to the development of more stable and potent analogues. In this study, we investigated GLP-1 analogues including those with N-, C-, and midchain modifications and a series of secretin-class chimeric peptides. Peptides were analyzed in CHO cells expressing the hGLP-1 receptor (R7 cells), and in vivo oral glucose tolerance tests (OGTTs) were performed after injection of the peptides in normal and diabetic (db/db) mice. [D-Ala(2)]GLP-1 and [Gly(2)]GLP-1 showed normal or relatively lower receptor binding and cAMP activation but exerted markedly enhanced abilities to reduce the glycemic response to an OGTT in vivo. Improved biological effectiveness of [D-Ala(2)]GLP-1 was also observed in diabetic db/db mice. Similarly, improved biological activity of acetyl- and hexenoic-His(1)-GLP-1, glucagon((1-5)-, glucagon((1-10))-, PACAP(1-5)-, VIP(1-5)-, and secretin((1-10))-GLP-1 was observed, despite normal or lower receptor binding and activation in vitro. [Ala(8/11/12/16)] substitutions also increased biological activity in vivo over wtGLP-1, while C-terminal truncation of 4-12 amino acids abolished receptor binding and biological activity. All other modified peptides examined showed normal or decreased activity in vitro and in vivo. These results indicate that specific N- and midchain modifications to GLP-1 can increase its potency in vivo. Specifically, linkage of acyl-chains to the alpha-amino group of His(1) and replacement of Ala(2) result in significantly increased biological effects of GLP-1 in vivo, likely due to decreased degradation rather than enhanced receptor interactions. Replacement of certain residues in the midchain of GLP-1 also augment biological activity.

Estimation of potential lifetime cancer risks for trihalomethanes from consuming chlorinated drinking water in Taiwan.

Data on concentrations of trihalomethanes (THMs) in raw and chlorinated water collected from three water treatment plants in Taiwan and estimates of the lifetime cancer risk for THMs from drinking water, using age-adjusted factors and volatilization terms, are presented. Data on THM levels in drinking water were obtained from the annual reports of the Environmental Protection Administration (EPA) of Taiwan. The methodology for estimation of lifetime cancer risks was taken from the USEPA. Chloroform was the major species of THMs, especially in the water plant of south Taiwan. Chloroform contributed the majority of the lifetime cancer risks (range: 87.5-92.5%) of total risks from the three water supply areas. All lifetime cancer risks for CHCl(3), CHBrCl(2), CHBr2Cl, and CHBr3 from consuming tap water in the three water supply areas were higher than 10(-6). The sum of lifetime cancer risks for CHCl(3), CHBrCl(3), CHBr2Cl, and CHBr3 was highest (total risk for total THMs<1.94x10(-4)) for tap water from south Taiwan.

Characterization of glucagon-like peptide-1 receptor-binding determinants.

Glucagon-like peptide 1 (GLP-1) is a potent insulinotropic hormone currently under study as a therapeutic agent for type 2 diabetes. Since an understanding of the molecular mechanisms leading to high-affinity receptor (R) binding and activation may facilitate the development of more potent GLP-1R agonists, we have localized specific regions of GLP-1R required for binding. The purified N-terminal fragment (hereafter referred to as NT) of the GLP-1R produced in either insect (Sf9) or mammalian (COS-7) cells was shown to bind GLP-1. The physical interaction of NT with GLP-1 was first demonstrated by cross-linking ((125)I-GLP-1/NT complex band at approximately 28 kDa) and secondly by attachment to Ni(2+)-NTA beads. The GLP-1R NT protein attached to beads bound GLP-1, but with lower affinity (inhibitory concentration (IC(50)): 4.5 x 10(-7) M) than wild-type (WT) GLP-1R (IC(50): 5.2 x 10(-9)M). The low affinity of GLP-1R NT suggested that other receptor domains may contribute to GLP-1 binding. This was supported by studies using chimeric glucose-dependent insulinotropic polypeptide (GIP)/GLP-1 receptors. GIP(1-151)/GLP-1R, but not GIP(1-222)/GLP-1R, exhibited specific GLP-1 binding and GLP-1-induced cAMP production, suggesting that the region encompassing transmembrane (TM) domain 1 through to TM3 was required for binding. Since it was hypothesized that certain charged or polar amino acids in this region might be involved in binding, these residues (TM2-TM3) were analyzed by substitution mutagenesis. Five mutants (K197A, D198A, K202A, D215A, R227A) displayed remarkably reduced binding affinity. These studies indicate that the NT domain of the GLP-1R is able to bind GLP-1, but charged residues concentrated at the distal TM2/extracellular loop-1 (EC1) interface (K197, D198, K202) and in EC1 (D215 and R227) probably contribute to the binding determinants of the GLP-1R.

Lead in the southern East China Sea.

At present, in most oceans the lead (Pb) biogeochemical cycling has been disturbed by anthropogenic Pb through atmospheric input. The Pb concentrations in the upper water positively correlate with atmospheric input fluxes of Pb. The North Pacific is affected greatly by atmospheric substances via long-range transport from eastern Asia, especially from Mainland China. Mainland China may export considerable amounts of pollutants into the seas via rivers and the atmosphere owing to its recent fast growth in industry and economy. The East China Sea lies in an important geographical position--a transit between Mainland China and the western North Pacific. However, no data are available for seawater concentrations of Pb, a representative element with anthropogenic origin. In this work seawater samples from both 5 and 30-50 m water layers of 15 stations occupied over a cyclonic eddy in the southern East China Sea were analyzed for particulate Pb (PPb) and dissolved Pb (DPb). The Mean concentration of DPb (approximately 128 ng/l) in the southern East China Sea upper waters (< or = 50 m) is approximately several times higher than those in the Pacific; the high DPb concentrations in the southern East China Sea waters correspond to much higher atmospheric supplies of Pb to the East China Sea. Thus, this study partly fills the 'data gap' of the marginal seas. Also, it indicates that the East China Sea may be considerably contaminated by deposited polluted aerosols. Spatial distributions of DPb in the surface water show a tendency of increasing concentrations with distance offshore, that depends on the magnitudes of atmospheric Pb inputs and on particle scavenging processes. In contrast to DPb, spatial distributions of PPb basically display an 'omega'-like picture and a tendency of decreasing concentrations with distance offshore. These are related to riverine and scavenging sources and to the drive by the eddy. Additionally, the residence times of DPb in the surface water were estimated to be about 2 years, agreeing well with the reported data.

Mussel watch: a review of Cu and other metals in various marine organisms in Taiwan, 1991-98.

This study presents the distribution of Cu, Zn, Pb, Cd, Hg and As in various marine organisms collected along the western coast of Taiwan from 1991 to 1998, and also evaluates the time variation of Cu in oysters before (1980-85) and after (1986-98) the "green oyster" incident. The results show that relatively high geometric mean (GM) concentrations of Cu, Zn, Pb, Cd, As and Hg were generally found in Crassostrea gigas (Cu=229 microg/g, Zn=783 microg/g), Gomphina aeguialtera (Pb=30.3 microg/g), Tegillarca granosa (Cd=2.85 microg/g), Thais clavigera (As=96.9 microg/g) and Parapenaeopsis cornuta (Hg=1.35 microg/g), respectively. Especially, maximum Cu and Zn concentrations (GM=229 and 783 microg/g, respectively) in oysters (C. gigas) from different culture areas were much higher than those of the other organisms by about 1.13-458 and 2.40-63.7 times, respectively. Similarly, rock-shells (Thais clavigera) had a high capacity for accumulating Cu (GM=202 microg/g) and Zn (GM=326 microg/g) under the same physico-chemical conditions. The highest GM Cu and Zn concentrations of 1108 (range from 113 to 2806) and 1567 (range from 303 to 3593) microg/g were obtained in oysters from the Hsiangshan coastal area, one of the most important oyster culture areas in Taiwan. However, the highest GM Cd and As concentrations of 6.82 and 19.3 microg/g were found in oysters from the Machu Islands. Mean Cu concentrations in the oysters from the Erhjin Chi estuary declined from 2194+/-212 microg/g in 1986-90 to 545 microg/g (GM) in 1991-96. In the Hsiganshan area, GM Cu concentrations of 909 microg/g (1991-96) and 1351 microg/g (1997-98) in oysters were significantly higher than those of 201 microg/g (1980-85) and 682 microg/g (1986-90). The gradually increasing levels of Cu and Zn in the oysters from the Hsiangshan area have been observed year by year.

Estimation of metal and organochlorine pesticide exposures and potential health threat by consumption of oysters in Taiwan.

Pollutant concentrations detected in oysters from 12 different culture areas of Taiwan (especially for the Hsiangshan area and the Machu Islands) from 1991-98 were evaluated to investigate potential carcinogenic (inorganic As and organochlorine pesticides) and non-carcinogenic (Cu, Zn, Cd and inorganic As) risk to the public from ingestion of the oysters. The highest geometric mean (GM) Cu and Zn concentrations of 1108 (range 113-2806) and 1567 (range 303-3593) microg/g dry weight were obtained in oysters from the Hsiangshan coastal area. The maximum GM Cd and As concentrations of 6.82 and 19.3 microg/g dry weight were found in oysters from the Machu Islands area. The p,p'-DDE values range from not detectable in Penghu Islands' oysters to 164 ng/g dry weight in Machu Islands' oysters. The highest tDDT (sum of p,p'-DDE, p,p'-DDD and p,p'-DDT) concentrations of 337 and 340 ng/g dry weight were found in oysters from Kimmen and Machu Islands, respectively. A calculated target hazard quotient (THQ; daily intake/reference dose) of 11.4 (based on 139 g oysters/day) for Cu caused by consuming oysters from the Hsiangshan area is higher than that from other areas (range 0.124-5.95). The highest average Cu intake from Hsiangshan's oysters for individuals is 11.4 times (i.e. THQ=11.4) more than that of reference dose (40 microg/kg/day). However, the maximum THQ values for Cd and As caused by consuming oysters collected from the Machu Islands were 5.57 and 2.63 for Cd and As, respectively. Generally, the results of THQ showed that if only the maximally exposed individuals were considered, the value of 65.4% for oyster was higher than 1.0 in comparison with reference dose. All cancer risk estimates for inorganic As from consuming oysters were higher than 10(-6) (range from 128x10(-6) to 509x10(-6) for maximally exposed individuals and range from 17.1x10(-6) to 68.0x10(-6) for typically exposed individuals, respectively); that is the risk of the lower end of the range of acceptable risk. The highest risk estimate for inorganic As was 509x10(-6) for consumption of oysters by Machu Islands' residents. The lifetime cancer risks of 19.0x10(-6) for tDDT by consuming oysters from the Machu Islands was higher than those from the Penghu Islands (0.37x10(-6)). Therefore, the sum of lifetime cancer risks for tDDT and inorganic As had the highest risks (total risk=528x10(-6)) of consuming oysters from the Machu Islands. Furthermore, a 10(-6) upper limit on lifetime risk as the health protection standard would require maximum oyster consumption rates of approximately 0.26 g/day.

Estimation of target hazard quotients and potential health risks for metals by consumption of seafood in Taiwan.

The purpose of this paper is to describe the impact of metal pollution on the main seafood and assess the potential health risk from consuming the contaminated seafood in Taiwan. The results of geometric mean (GM) metal concentrations in various seafood showed that the copper, zinc, and arsenic concentrations in oysters were significantly (p < 0.001) higher than those in the other seafood by about 1,057, 74.3, and 56.2 times, respectively. The green color found in the oysters was due to high GM copper and zinc concentrations of 909 (ranging from 113-2,805) and 1,293 (ranging from 303-3,593) microg/g dry wt, respectively. In addition, using a maximum consumption rate of 139 g/day of oysters for individuals, calculations yield target hazard quotients (daily intake/reference dose) of below 1 for cadmium and mercury and high values of 1.61, 9. 33, and 1.77 for inorganic arsenic, copper, and zinc in adults, respectively. The various lifetime cancer risks for inorganic arsenic (maximum exposed individuals risk ranging from 9.93 x 10(-6) to 3.11 x 10(-4)) might be caused by consuming different seafood in Taiwan. The highest risk estimate for inorganic arsenic was 5.10 x 10(-4) for consumption of oysters by Machu Islands residents. The long-term exposure of metals through consumption of oysters, especially for some high-risk groups, could be dangerous. Taking inorganic arsenic for example, a 10(-6) upper limit on lifetime risk as the health protection standard would require maximum oyster residue levels of approximately 0.0076-0.056 microg/g wet wt, for consumption rates of 139-18.6 g/d. In the light of known risks to public health, the government should issue an immediate warning to the public to refrain from eating all seafood harvested from the Taiwan coastal areas, especially the Hsiangshan area and the Machu Islands.

Rock-shells (Thais clavigera) as an indicator of As, Cu, and Zn contamination on the Putai Coast of the black-foot disease area in Taiwan.

This study presents the distribution of arsenic (As), copper (Cu), and zinc (Zn) in various seafoods-oysters (Crassostrea gigas), false fusus (Hemifuscus tuba), venus clams (Cyclina sineasis), green mussels (Perna viridis), blood clams (Arca granosa), flounders (Psettodes erumei), and rock-shells (Thais clavigera) collected from the Putai coast of the black-foot disease (BFD) area in Taiwan. Special attention is paid to evaluate the relationships among As, Cu, and Zn and effect of body size on metal concentration in Thais clavigera. Maximum Zn and Cu geometric mean (GM) concentrations (GM = 615 and 376 microg/g, dry wt, respectively) are found in oysters (Crassostrea gigas), and the values are much higher than those of the other organisms by about 1.7-208 and 1.8-375 times, respectively. Similarly, Thais clavigera has a high capacity for accumulating Cu and Zn collected from the same location. One interesting point is that relatively high As concentrations (GM = 65.7 microg/g, dry wt) in Thais clavigera are found as compared with those in other organisms (range from GM = 2.37 to 40.2 microg/g, dry wt). The As concentrations are significantly higher in Thais clavigera (1.62-27.7 times) than those in other organisms (p < 0.05), except for the false fusus (Hamifuscus tuba). A linear regression analysis shows a significant increase in Zn concentration with increasing Cu concentration in Thais clavigera. On the other hand, the As concentration is correlated with Cu and Zn concentrations (r = 0.77 and 0.77, respectively; p < 0.05) in Thais clavigera. Double logarithmic plots of metal content and concentration against dry-body weight and shell length show linear relationships. The result indicates that large individuals have higher contents of Cu, Zn and As, and have slopes of 1.58, 1.38, and 1.34, respectively. In addition, metal concentrations against shell length for all animal sizes also indicate that Cu, Zn and As have slopes of 1.92, 1.18, and 1.11, respectively. In conclusion, Thais clavigera has a high capactiy for accumulating As, Cu, and Zn and is a potential bioindicator for monitoring As, Cu and Zn.

Monitoring lead pollution near a storage battery recycling plant in Taiwan, Republic of China.

This study presents the distribution of blood lead levels and lead in various environmental samples (water, sediments, soils, and air) near the Shing-Yie storage battery recycling plant in Taiwan before (July 1990 to June 1991) and after (July 1992 to June 1993) amelioration. Before amelioration, the average blood lead levels in the neighborhood of the plant were in the range of 10.55 +/- 5.7 to 12.28 +/- 7.9 micrograms/dl. After amelioration, relatively lower average concentrations of blood lead (range 8.35 +/- 3.0 to 9.13 +/- 2.5 micrograms/dl) were generally found; however, these averages were still higher than that (7.79 +/- 3.5 micrograms/dl) from other lead-unpolluted areas of Taiwan. An exceedingly high geometric mean (GM) lead concentration (128 micrograms/L) was found in the downstream river water of the Tawulum River passing by the plant. The concentrations of lead (GM = 372 and 418 micrograms/g) in the downstream river sediments were higher than those (GM = 123 and 158 micrograms/g) in the upstream river sediments before and after amelioration, respectively. Furthermore, lead species in river sediments were analyzed by a sequential leaching technique. The sum of phases I, II, and III accounted for 83.7% of total lead at station R2 (nearest to the plant). Maximum lead concentration (GM = 2402 micrograms/g) in dust at the soil surface from station S1 (nearest to the plant) was much higher than those from the other stations by about 18 times before amelioration. However, the maximum value dropped to 1,155 micrograms/g after amelioration. On the whole, the geometric mean concentration of lead in dust at the soil surface nearest to the plant was > 1,000 micrograms/g and decreased to < 100 micrograms/g in the 15-30 cm depth soil about 2 km away from the plant. Before amelioration, the geometric mean lead concentration of 4.57 micrograms/m3 (range 0.102-37.6 micrograms/m3) in the air near the plant was higher than that at the background locations, the geometric mean value of which was 0.08 micrograms/m3.

Relationship between copper speciation in sediments and bioaccumulation by marine bivalves of Taiwan.

This paper evaluates the relationships between copper species in sediments and accumulation by the purple clam (Hiatula diphos) and venus clam (Gomphina aeguilatera) collected from the field and culture (aquaculture) ponds in the polluted coastal area of Lukang, Taiwan. Sediment was sampled along with the molluscs, including oysters (Crassostrea gigas), purple clams (Hiatula diphos), rock-shells (Thais clavigera), venus clams (Gomphina aeguilatera), and hard clams (Meretrix lusoria), from two unique environments of Lukang during the period from August 1993 to July 1994. The data indicate that the total copper concentrations in sediments from culture ponds (185 microg g(-1)) was higher than those of the field (44.0 microg g(-1)). Copper species in sediments were analyzed by a sequential leaching technique. Results show that concentrations of various copper species in the sediments are in the range of 1.14 +/- 0.59 to 13.2 +/- 22.4 microg g(-1) and 0.36 +/- 0.24 to 133 +/- 36.7 microg g(-1) for the two environments, respectively. Also the exchangeable copper in sediment from culture ponds was 15 times higher than that from the field. In addition, the sum of exchangeable and copper carbonates had the highest percentages of copper in both the pond sediment (86.6 %) and the field sediment (50.7 %). Maximum copper concentrations (309 +/- 35.1 microg g(-1)) in oysters were much higher than those in the other benthic organisms by about 4-127 times. Similarly, the data also showed that copper concentrations in Thais clavigera were 12-32 times higher than those in other benthic organisms. Copper concentrations in various benthic organisms differed significantly (p < 0.05) from that in Thais clavigera. This capacity makes Thais clavigera a potential candidate for monitoring copper in marine sediments. In terms of copper species, the best correlation was generally obtained between copper carbonates in sediments and copper concentrations in Hiatula diphos (r = 0.886*). A strong multiple regression correlation (p < 0.05, r2 = 0.7894) also indicates that the copper carbonates may dominate as the available form of copper to Hiatula diphos from various environments in the Lukang coastal area under natural physicochemical conditions.