Analysis of persistent organochlorine pesticides in shellfish and their risk assessment from aquafarms in Taiwan

In Taiwan, freshwater clams (Corbicula fluminea) and hard clams (Meretrix lusoria) are the most frequently raised shellfish in land-based pond aquaculture, but research on the accumulation of organochlorine pesticides (OCPs) in these shellfish is limited. We detected the levels of 14 OCPs in 62 shellfish from Taiwanese aquafarms by performing gas chromatography-tandem mass spectrometry. OCP residues were detected in 4.84% of the samples including readings of 0.04 mg/kg chlordane (in a freshwater clam), 0.03 mg/g p,p'-DDE (in a freshwater clam), and 0.02 mg/g p,p'-DDE (in a hard clam). However, the associated estimated daily intake values were less than the acceptable daily intake levels of chlordane and p,p'-DDE Therefore, the consumption of these shellfish presents no immediate health risks. Our findings contribute to food safety and serve as a reference for OCP screenings for aquatic shellfish.

The Ameliorative Effects of Fucoidan in Thioacetaide-Induced Liver Injury in Mice

Liver disorders have been recognized as one major health concern. Fucoidan, a sulfated polysaccharide extracted from the brown seaweed Fucus serratus, has previously been reported as an anti-inflammatory and antioxidant. However, the discovery and validation of its hepatoprotective properties and elucidation of its mechanisms of action are still unknown. The objective of the current study was to investigate the effect and possible modes of action of a treatment of fucoidan against thioacetamide (TAA)-induced liver injury in male C57BL/6 mice by serum biochemical and histological analyses. The mouse model for liver damage was developed by the administration of TAA thrice a week for six weeks. The mice with TAA-induced liver injury were orally administered fucoidan once a day for 42 days. The treated mice showed significantly higher body weights; food intakes; hepatic antioxidative enzymes (catalase, glutathione peroxidase (GPx), and superoxide dismutase (SOD)); and a lower serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), and C-reactive protein (CRP) levels. Additionally, a reduced hepatic IL-6 level and a decreased expression of inflammatory-related genes, such as cyclooxygenase-2 (COX-2), and inducible nitric oxide synthase (iNOS) mRNA was observed. These results demonstrated that fucoidan had a hepatoprotective effect on liver injury through the suppression of the inflammatory responses and acting as an antioxidant. In addition, here, we validated the use of fucoidan against liver disorders with supporting molecular data.

Quantification of Fusarium graminearum in harvested grain by real-time polymerase chain reaction to assess efficacies of fungicides on fusarium head blight, deoxynivalenol contamination, and yield of winter wheat

We used a real time polymerase chain reaction-based assay and visual disease assessment to evaluate the efficacies of Js399-19, tebuconazole, a mixture of tebuconazole and thiram, azoxystrobin, carbendazim, and thiram on the development of Fusarium head blight (FHB) and deoxynivalenol (DON) contamination and on the yield of winter wheat (cv. Nannong no. 9918) after artificial inoculation under field conditions with Fusarium graminearum. The incidence of infected spikelets (IIS), amount of F. graminearum DNA (Tri5 DNA), total DON (containing DON, 3-acetyl-deoxynivalenol, and 15-acetyl-deoxynivalenol) concentration, and 1,000-grain weight (TGW) were quantified in 2006 and 2007. A strong positive correlation was found between IIS or Log10Tri5 DNA and total DON concentration in the harvested grain. The Js399-19, tebuconazole, and the mixture of tebuconazole and thiram significantly reduced IIS of FHB, amount of Tri5 DNA, and total DON within the grain and increased TGW. Although azoxystrobin, carbendazim, and thiram can increase TGW, they had no effect on the occurrence of F. graminearum compared with those of the untreated controls. Surprisingly, azoxystrobin and carbendazim significantly increased the total DON content in the harvested grain because they might have stimulated the amount of total DON production per Tri5 DNA. The fungicides Js399-19, tebuconazole, and the mixture of tebuconazole and thiram were the most effective in controlling FHB and reducing DON contamination of the wheat.

Effects of ultraviolet B irradiation, proinflammatory cytokines and raised extracellular calcium concentration on the expression of ATP2A2 and ATP2C1

BACKGROUND

Darier disease (DD) and Hailey-Hailey disease (HHD) are autosomal dominantly inherited skin disorders that histologically share the characteristics of suprabasal separation and acantholysis of epidermal keratinocytes. Various mutations in the DD gene (ATP2A2) and the HHD gene (ATP2C1) (respectively encoding the calcium pumps of the sarco/endoplasmic reticulum and the Golgi apparatus) have recently been described in multiple families with DD and HHD. Mutations in ATP2A2 or ATP2C1 have been suggested as causing the conditions via the mechanism of haploinsufficiency. Ultraviolet (UV) B irradiation is thought to be an aggravating factor in both diseases.

OBJECTIVES

To examine the effects of various stimuli on ATP2A2 and ATP2C1 mRNA expression, and to examine the role of calcium pumps during keratinocyte differentiation.

METHODS

The effects of UVB irradiation, of UVB-inducible inflammatory cytokines produced by keratinocytes and of high-calcium medium (1.8 mmol L(-1) as opposed to 0.08 mmol L(-1) Ca2+) on ATP2A2 and ATP2C1 mRNA expression were quantified in cultured normal human keratinocytes using reverse transcription-polymerase chain reaction.

RESULTS

Expression of ATP2A2 and ATP2C1 mRNA was suppressed immediately after exposure to UVB irradiation, and modulation of mRNA expression was achieved in keratinocytes cultured with proinflammatory cytokines. The mRNA expression of both genes was increased significantly after the shift to high extracellular Ca2+ concentration.

CONCLUSIONS

The results suggest that modulation of ATP2A2 and ATP2C1 mRNA expression by UV or cytokines might contribute to the clinical presentations unique to DD and HHD, and that the controlled expression of these genes plays an important role in keratinocyte homeostasis, function and differentiation.

Reproducible gene expression measurement among multiple laboratories obtained in a blinded study using standardized RT (StaRT)-PCR

BACKGROUND

A method that provides standardized data and is relatively inexpensive and capable of high throughput is a prerequisite to the development of a meaningful gene expression database suitable for conducting multi-institutional clinical studies based on expression measurement. Standardized RT (StaRT)-PCR has all these characteristics. In addition, the method must be reproducible. StaRT-PCR has high intralaboratory reproducibility. The purpose of this study is to determine whether StaRT-PCR provides similar interlaboratory reproducibility.

METHODS AND RESULTS

In a blinded interlaboratory study, expression of ten genes was measured by StaRT-PCR in a complementary DNA sample provided to each of four laboratories. The average coefficient of variation for interlaboratory comparison of the nine quantifiable genes was 0.48. In all laboratories, expression of one of the genes was too low to be measured.

CONCLUSION

Because StaRT-PCR data are standardized and numerical and the method is reproducible among multiple laboratories, it will allow development of a meaningful gene expression database.

Initial evidence of endothelial cell apoptosis as a mechanism of systemic capillary leak syndrome

BACKGROUND

Systemic capillary leak syndrome (SCLS) is a rare disorder of unknown etiology that is characterized by acute recurrent attacks of hypovolemic shock commonly following an inflammatory stimulus such as a viral illness. Prophylactic therapy is generally ineffective, and the outcome is frequently fatal.

METHODS

In order to investigate the cellular mechanisms leading to SCLS, we examined the effects of sera from two patients with active SCLS on microvascular endothelial cell apoptosis in vitro. Apoptosis was determined by morphologic criteria, DNA fragmentation, annexin V stain, and by a quantitative photometric assay. The apoptotic pathway was investigated by Western blot of endothelial cells lysate after exposure to SCLS sera.

RESULTS

The sera from patients with active SCLS mediated profound apoptosis of microvascular endothelial cells shortly after exposure. The exposed microvascular endothelial cells underwent immediate apoptosis as evidenced by morphologic changes, plasma membrane phosphatidylserine exposure, and by DNA fragmentation. Increased Bax/Bcl-2 ratio in endothelial cells exposed to SCLS sera was observed and suggested an oxidation injury as the possible mechanism for endothelial apoptosis. This potential mechanism was further explored by measuring intracellular reactive oxygen species (ROS) following SCLS serum exposure. Sera from both patients caused marked increases in ROS, initially detectable at 1 h and persisted for at least 12 h, with control serum from healthy subjects showing no effect on basal endothelial cell ROS concentrations.

CONCLUSION

Components from the sera of patients with active systemic capillary leak syndrome in contrast to healthy subject sera mediate early and extensive endothelial apoptosis in vitro that is associated with oxidation injury. These data represent compelling initial evidence for oxidation-induced apoptosis as a likely mechanism for endothelial injury leading to SCLS.

Effect of quercetin on adhesion of platelets to microvascular endothelial cells in vitro

AIM

To study the effect of quercetin(Que) on the adhesion of platelets to microvascular endothelial cells (MVEC) isolated from human skin.

METHODS

[3H]-adenine-labeled platelets were incubated with MVEC. Effect of Que on platelet endothelial cell adhesion molecular (PECAM) expression on MVEC was also evaluated using enzyme-linked immunosorbent assay (ELISA).

RESULTS

Adhesion of platelet to MVEC reached to maximum at about 30 min. Que inhibited the adhesion of platelets to MVEC in a concentration-dependent manner. Que 5 micromol/L did not show any significant inhibition. When the concentration of Que increased to 10, 20, and 40 micromol/L, the inhibition rate increased to 10.5 %, 20.0 %, and 42.2 %, respectively. Pre-incubation of Que (10 - 40 micromol/L) with labeled platelets for 30 min also inhibited the adhesion but Que 5 micromol/L did not. The inhibition rate of Que 10, 20, and 40 micromol/L was 18.2 %, 29.8 %, and 65.3 % respectively. Expression of PECAM on the endothelial cells was decreased in a concentration-dependent manner when MVEC were treated with Que (10 - 40 micromol/L) for 12 h but Que 5 micromol/L did not significantly affect the expression.

CONCLUSION

Que could inhibit the adhesion of platelets to MVEC. This effect may be related to decreased expression of PECAM on MVEC.

Nerve growth factor and neuropeptides circulating levels in systemic sclerosis (scleroderma)

OBJECTIVE

To determine the circulating levels of nerve growth factor (NGF), neuropeptide Y (NPY), and vasoactive intestinal peptide (VIP) in systemic sclerosis (SSc), and to correlate these levels with clinical and laboratory features.

METHODS

Forty four patients with SSc were evaluated for circulating NGF (immunoenzymatic assay), NPY and VIP (radioimmunoassay), anticentromere and antitopoisomerase I autoantibodies, lung disease (pulmonary function tests with carbon monoxide transfer factor (TLCO), ventilation scintiscan with 99mTc DTPA radioaerosol, high resolution computed tomography (HRCT), pulmonary pressure (echo colour Doppler)), heart disease (standard and 24 ECG, echocardiography), cutaneous involvement (skin score), joint involvement (evidence of tender or swollen joints, or both), peripheral nervous system (PNS) involvement (electromyography), rheumatoid factor, angiotensin converting enzyme (fluorimetric method), von Willebrand factor (ELISA), and erythrocyte sedimentation rate (ESR) (Westergren).

RESULTS

Circulating NGF levels in SSc were significantly increased compared with controls (p<0.00001) and significantly higher in the diffuse than in the limited subset of patients (p<0.01). Patients with articular disease had significantly higher levels of NGF. A significant indirect correlation between NGF levels and TLCO was detected (p<0.01), but no correlation was found between NGF and HRCT, DTPA, skin score, PNS involvement and angiotensin converting enzyme and von Willebrand factor levels, antitopoisomerase or anticentromere antibodies, and ESR. NGF levels increased progressively as the disease worsened. Similarly, VIP circulating levels were significantly increased in patients with SSc (p<0.001), whereas the increase of NPY levels did not reach statistical significance. However, both neuropeptides, following the same trend as NGF, increased as the disease worsened (skin score and lung disease).

CONCLUSIONS

The increase of NGF and VIP in patients with SSc, the former in the diffuse subset of the disease, and in patients with prominent articular disease, may suggest a link between neurotransmitters and the disease pathogenesis. Neuropeptide circulating levels seem to increase only in patients with the most severe disease.

Gammadelta receptor bearing T cells in scleroderma: enhanced interaction with vascular endothelial cells in vitro

In view of the documented perivascular mononuclear cell infiltration in the involved organs in scleroderma (SSc) and the reported accumulation of gammadelta-T cells in SSc skin and lung, we evaluated gammadelta-T cell interaction with endothelial cells (EC) in vitro. gammadelta- and alphabeta-T cells were isolated from BPMN of SSc patients with early diffuse disease and of matched control subjects by an immunomagnetic method after stimulation with mycobacterium lysate and interleukin-2 for 2 weeks. Lymphocyte adhesion, proliferation, and cytotoxicity to EC were investigated. SSc gammadelta-T cells adhered to cultured EC and proliferated at higher rates than control cells. Furthermore, significant EC cytotoxicity by SSc gammadelta was seen. The cytotoxicity was blocked by addition of anti-gammadelta-TCR antibody and by anti-granzyme A antibody but not by anti-MHC class I and II antibodies. Expression of granzyme A mRNA was seen in five/five SSc gammadelta-T cells and in one/five control cells. alphabeta-T cells from both SSc and control subjects were significantly less interactive with EC than gammadelta-T cells. The data demonstrate EC recognition by SSc gammadelta-T cells and propose gammadelta-T cells as a possible effector cell type in the immune pathogenesis of SSc.

Mechanism of serum-mediated endothelial injury in scleroderma: identification of a granular enzyme in scleroderma skin and sera

Circulating endothelial cell growth-inhibitory factor with a molecular weight of 40-60 kDa was described in scleroderma (SSc) sera and shown to have a proteolytic action. In view of the recent demonstration of cellular immune activation in SSc, and because of the description of novel serine proteases in the granules of activated cytolytic T cells (granzymes), we hypothesized that granzymes represent the endothelial inhibitory principal in SSc sera. Granular enzymes were isolated from IL-2-activated nonadherent normal lymphocytes, and a 60-kDa granzyme was isolated using benzamidine-affinity column and molecular sieve column. A polyclonal antiserum was generated by immunizing rabbits with the isolated granzyme. Anti-granzyme antibody abolished SSc serum-mediated EC growth inhibition. Furthermore, a circulating protein similar to isolated granzyme was identified as a 60-kDa band on Western blots of benzamidine column-purified SSc sera. Immunofluorescence studies of SSc skin biopsies using anti-granzyme antibody demonstrated the presence of granzyme reactivity, while healthy control tissues were negative. Moreover, granzyme A gene expression was identified in SSc skin biopsies by a PCR method. The data suggest cytolytic mechanism involvement in the pathogenesis of scleroderma.

Effect of cytokines on the production of endothelin by endothelial cells

OBJECTIVE

Circulating levels of endothelin (ET), a potent vasoconstrictor peptide and a mitogen for smooth muscle cells and fibroblasts, are reported to be increased in a variety of human diseases characterized by vascular pathology. In view of the probable immune bases for vascular injury in connective tissue disorders, we examined the effect of the cytokines IL-1 alpha, IL-4, IL-6, TNF-alpha and lymphotoxin on the production of ET-1 by cultured vascular endothelial cells.

RESULTS

ET levels in endothelial cell conditioned media were measured by radioimmunoassay. IL-4 and lymphotoxin had no effect on ET release by endothelial cells, while IL-6, TNF-alpha and IL-1 alpha stimulated ET mRNA expression and ET release in a dose dependent fashion. IL-6 was the most potent stimulator and IL-1 was the least effective. The addition of neutralizing antibodies to the cytokines inhibited the observed increase in ET release.

CONCLUSIONS

These results suggest that cytokines may play a significant role in the control of vascular tone. Furthermore, cytokines may indirectly contribute to the development of proliferative vascular lesions by stimulating smooth muscle and interstitial cell proliferation through their effects on endothelin release by the vascular endothelium.

Effects of quercetin on Na(+)-K(+)-exchanging ATPase and Ca(2+) Mg(2+)-ATPase in rats

Quercetin (Que) ig 200 mg.kg-1, qd x 14 d decreased activities of the Na(+)-K(+)-exchanging ATPase (I) of rat brain plasma membranes and heart sarcolemmal and Ca(2+) Mg(2+)-ATPase (II) of heart sarcolemmal membrane. Que 100 mg.kg-1 reduced the activity of I from rat heart sarcolemmal preparation, but had no effect on that from rat brain plasma membranes. The result shows that I of myocardium is more sensitive than that of brain in rat. Que also showed a remarkable inhibitory effect in the II of heart sarcolemma.

[Effects of total saponins of Panax notoginseng on increasing PGI2 in carotid artery and decreasing TXA2 in blood platelets]

Total saponins of Panax notoginseng (PNS) were given orally 100 mg/(kg.d) to rabbit for 8 wk. Aortic atherosclerotic plaque formation was restrained as compared to the control group. Radioimmunoassay was used to investigate the effects of PNS on the contents of prostacyclin in carotid artery and thromboxane A2 in blood platelets of rat. Oral administration of PNS 25,50,100 mg/(kg.d) for 10 d, the caused an increase of prostacyclin in carotid artery and a decrease of thromboxane A2 in blood platelets as compared to the control group. These results show that the anti-atherosclerotic action of PNS may be a result of the correction of the unbalance between prostacyclin and thromboxane A2.